path: root/0620.json

{
    "2002": {
        "0620_w02_qp_1.pdf": {
            "1": "time 45 minutes instructions to candida tes do not open this booklet until you are told to do so. write your name, centre number and candidate number on the answer sheet in the spaces provided unless this has already been done for you. there are forty questions in this paper. answer all questions. for each question, there are four possible answers, a, b, cand d. choose the one you consider correct and record your choice in soft pencil on the separate answer sheet. read very carefully the instructions on the answer sheet. information for candidates each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet.a copy of the periodic table is printed on page 16. this question paper consists of 16 printed pages. mml 2088 9/01 s24517 \u00a9 cie 2002 [turn overinternational general certificate of secondary education cambridge international examinations chemistry 0620/1 paper 1 multiple choice october/november session 2002 45 minutes additional materials: multiple choice answer sheet soft clean erasersoft pencil (type b or hb is recommended) university ofcambridge local examinations syndicate ",
            "2": "1heating a liquid causes it to become a vapour. what happens to the molecules of the liquid during this process? 2some sugar is dissolved in water.which diagram shows how the particles are arranged in the solution? 3which stages occur in distillation?acondensation then evaporation bcondensation then filtration cevaporation then condensation dfiltration then evaporation2 0620/1/o/n/02a bcdthe molecules  become bigger \u0013 \u0013 \u2717\u2717the molecules move  further apart \u0013 \u2717 \u0013 \u2717 ab c dkey sugar particle water particle",
            "3": "4some paraffin is contaminated with soot (carbon). the soot is removed as shown. which method is used to remove the soot? acracking bcrystallisation cdiffusion dfiltration 5the diagrams show the nuclei of four different atoms. which two atoms are isotopes of each other? aq and r bq and t cr and s ds and t 6which atom has twice as many neutrons as protons?a 1 1h b2 1h c3 1h d4 2heqrst 10 p 10 p 10 n 12 n 14 n 14 n14 p 12 pkey p = proton n = neutronwire grid clothparaffin + soot clean paraffin3 0620/1/o/n/02 [turn over",
            "4": "7which change takes place when an atom becomes a positive ion? aan electron is added. ban electron is removed. ca proton is added. da proton is removed. 8the diagram shows an electric circuit. for which two substances at x and y does the bulb light up? 9one method of producing carbon dioxide is to react calcium carbonate with dilute hydrochloric acid. what is the balanced chemical equation for the reaction?acaco 3+h c l\u2192 cao + co2+h c l bcaco3+ 2hcl \u2192 cacl2+c o2+h2o ccaco3+ 4hcl \u2192 cacl4+c o2+h2+h2o dca(hco3)2+h c l\u2192 cacl + 2co2+h2oxybulb4 0620/1/o/n/02a bcdx coppercopper rubberrubbery graphite poly(ethene) graphite poly(ethene)",
            "5": "10a gas has the molecular formula nocl. which diagram could show molecules of the pure gas nocl? 11butenedioic acid has the structure shown. what is the molecular formula of butenedioic acid? acho bc4h4o4cc6h4o2dc6h4o6o ooo cc c ch h h hn cl oab cd key5 0620/1/o/n/02 [turn over",
            "6": "12the diagram represents the electrolysis of brine (aqueous sodium chloride). what are products x and y? 13copper wires in an electricity cable are covered in plastic. why is plastic used? ait is an insulator. bit is a polymer. cit is hard. dit melts easily.plastic copper wireplastic+ \u2013y negative electrodeporous wallpositive electrodebrine chlorine x6 0620/1/o/n/02a bcdx hydrogenhydrogen oxygenoxygeny aqueous sodium hydroxide hydrochloric acid aqueous sodium hydroxide hydrochloric acid",
            "7": "14a piece of magnesium is dropped into a test-tube containing dilute hydrochloric acid. why does the test-tube become warm? ahydrogen is produced. bthe magnesium neutralises the acid. cthe reaction is endothermic. dthe reaction is exothermic. 15an explosion in a coal mine was caused by the ignition of a mixture of methane and air.why did the mixture explode?athe heat absorbed by burning decreased the rate of burning. bthe heat absorbed by burning increased the rate of burning. cthe heat liberated by burning decreased the rate of burning. dthe heat liberated by burning increased the rate of burning.bubblesmagnesium dilute hydrochloric acid7 0620/1/o/n/02 [turn over",
            "8": "16the diagram shows an experiment to compare the speed of reaction when limestone chips are added to acid. in which test-tube is the reaction most rapid? 17which properties does a transition element have? 18which metals can be obtained by heating their oxides with carbon? 19aqueous lead( ii) nitrate is added to a solution containing iodide ions. lead( ii) iodide is formed. which type of reaction takes place? aneutralisation boxidation cprecipitation dreductionlimestone limestoneacid acidab c d dilute aciddilute acidconcentrated acidconcentrated acid8 0620/1/o/n/02a bcddensity highhigh lowlowmelting point high low high low abcdcopper \u2717 \u0013 \u2717 \u0013iron \u0013 \u0013 \u2717\u2717magnesium \u0013 \u2717 \u0013 \u2717",
            "9": "20which element reacts with dilute sulphuric acid to produce hydrogen? acarbon bchlorine ccopper dzinc 21for which ph change is there the largest increase in acidity? 22which statement about the electrical conductivity of non-metals and the charge on their ions is correct? 23the corrosion of iron and its extraction from hematite are important processes. which terms describe the corrosion of iron and its extraction from hematite?9 0620/1/o/n/02 [turn overa bcdinitial ph 1236final ph 3612 abcdelectrical conductivity goodgood poorpoorcharge on  ions positive negative positive negative abcdcorrosion oxidationoxidation reductionreductionextraction oxidation reduction oxidation reduction",
            "10": "24a few drops of aqueous bromine are added to separate aqueous solutions of potassium chloride, potassium bromide and potassium iodide. which solutions do not remove the colour of the bromine? akbr and kcl only bkbr and k ionly ckcland k ionly dkbr, kcl and k i 25which metal produces a solution of a metal hydroxide when added to water?acalcium bcopper ciron dzinc 26a highly reactive metal is likely toaform negative ions, boccur naturally as an element, coccur only as an oxide, doxidise rapidly in air.10 0620/1/o/n/02",
            "11": "27the diagram shows the manufacture of steel. what could gas x be? acarbon dioxide bchlorine chydrogen doxygen 28a student writes the following statements. 1 aluminium is used in the manufacture of aircraft bodies. 2 aluminium is used to make stainless steel.3 mild steel is used in the manufacture of car bodies. which statements are correct?a1 and 2 only b1 and 3 only c2 and 3 only d1, 2 and 3 29which substance is used in the purification of water?acalcium sulphate bcarbon dioxide cchlorine dsodium chloridemolten irongas x waste gases11 0620/1/o/n/02 [turn over",
            "12": "30which pollutant, found in car exhaust fumes, does not come from the fuel? acarbon monoxide bhydrocarbons clead compounds dnitrogen oxides 31which place on the map is most likely to be producing large quantities of sulphur dioxide? 32why does a bicycle chain that is coated with oil not rust? aoil dissolves any rust that forms. boil reacts with rust causing oxidation. coil reacts with oxygen so no rust forms. doil stops oxygen and water getting to the chain. 33which two other compounds should be added to ammonium sulphate to make a complete npk fertiliser? akno3, na2hpo4 bk2so4, kno3 cnacl, ca3(po4)2 dnh4cl, na2hpo4coal-fired power station b farm ac water purification  plantpetrol station in village dseariver12 0620/1/o/n/02",
            "13": "34two uses of oxygen are 1 burning acetylene in welding, 2 helping the breathing of hospital patients. which of these uses form carbon dioxide? 35lime is used to treat an industrial waste. which ph change occurs in the treatment? untreated waste \u2192 treated waste a acidic \u2192 neutral b alkaline \u2192 acidic c alkaline \u2192 neutral d neutral \u2192 acidic 36a compound q has the structure shown. what is the name of q?aheptane bheptanoic acid cheptanol dhepteneh hhchhc hhc hhc hhc hhc hhh countreated waste limetreated waste13 0620/1/o/n/02 [turn overa bcduse 1 \u0013 \u0013 \u2717\u2717use 2 \u0013 \u2717 \u0013 \u2717",
            "14": "37a student sets up the apparatus shown to separate petroleum into its different liquid parts. why does this method of separation work? the liquids in petroleum have different aboiling points, bdensities, cfunctional groups, dmelting points. 38which row in the table correctly shows properties of decane?themometer cold water heatpetroleum on rock wool14 0620/1/o/n/02a bcdburns \u0013 \u0013 \u2717\u2717is unsaturated \u0013 \u2717 \u0013 \u2717",
            "15": "39the equation shows the cracking of a hydrocarbon. which compounds are unsaturated? ax only by only cx and zd y and z 40a student states thatethanol reacts with water to form beer and wine; ethanol and water are used as solvents in industry. which of the underlined words are correct?h hh hcch hchh cc c c ch h hh hh hh hhhh =\u2013\u2013 \u2013\u2013 + xy z15 0620/1/o/n/02a bcdreacts \u0013 \u0013 \u2717\u2717solvents \u0013 \u2717 \u0013 \u2717",
            "16": "16 0620/1/o/n/02data sheet the periodic table of the elements the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).*58-71 lanthanoid series \u202090-103 actinoid series keya = relative atomic mass x= atomic symbol b = proton (atomic) numbergroup i 7 li lithium 39 be beryllium 4 23 na sodium 1124 mg magnesium 12 39 k potassium 1940 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 5 73 ge germanium 3228 si silicon 1412 c carbon 6 75 as arsenic 3331 p phosphorus 1514 n nitrogen 7 79 se selenium 3432 s sulphur 1616 o oxygen 8 80 br bromine 3535.5 cl chlorine 1719 f fluorine 9 84 kr krypton 3640 ar argon 1820 ne neon 104 he helium 2 85 rb rubidium 3788 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 133 cs caesium 55137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73 140 ce cerium 58 a x b232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 103141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87226 ra radium 88227 ac actinium 89 \u20201 h hydrogen 1ii iii iv v vi vii 0"
        },
        "0620_w02_qp_2.pdf": {
            "1": "this question paper consists of 16 printed pages. \u00a9 cie 2002  [turn overcentre numbercandidate number candidate name international general certificate of secondary education cambridge international examinations chemistry paper 2 october/november session 2002 1 hour candidates answer on the question paper. no additional materials are required. time 1 hour instructions to candidates write your name, centre number and candidate number in the spaces at the top of this page. answer all questions. write your answers in the spaces provided on the question paper. information for candidates the number of marks is given in brackets [ ] at the end of each question or part question.you may use a calculator.a copy of the periodic table is printed on page 16. for examiner\u2019s use 1 2 3 4 5 6 total",
            "2": "0620/2 nov022 1ammonia, nh 3, is synthesised by the following route.       methane  /g190/g190/g190/g190/g190/g190/g174  hydrogen iron catalyst /g190/g190/g190/g190/g190/g190/g174 ammonia         air     /g190/g190/g190/g190/g190/g190/g174  nitrogen (a) (i) to which group of organic compounds does methane, ch 4, belong? put a ring around the correct answer. alkane alcohol alkene carboxylic acid [1] (ii) draw the formula for methane, showing all atoms and bonds. [1] (iii) state the most likely source of methane. [1] (b) (i) state the percentage of nitrogen in clean air. [1] (ii) name another non-metal that is in the same period as nitrogen. [1] (c)ammonia is made by heating hydrogen with nitrogen in the presence of a catalyst. (i) what is the purpose of the catalyst? [1] (ii) what happens to the rate of a reaction when the temperature is increased? [1] for examiner\u2019s use",
            "3": "0620/2 nov 2002 turn over3 (d) (i) complete the following equation which shows the synthesis of ammonia from hydrogen and nitrogen. 3h 2       +        n 2 \u2026 nh 3 [1] (ii) what does the sign               mean? [1] (e)the ammonia formed in the reaction is liquefied. complete the diagram below to show the arrangement of the molecules in liquid ammonia. represents a single molecule of ammonia. [2] (f)how would you test for ammonia in the laboratory? test result [2] (g)ammonia is used to make fertilizers. (i) why are fertilizers used in agriculture? [1] (ii) some fertilizers contain ammonium sulphate. complete the word equation to show how ammonium sulphate is formed. ammonia   + /g190/g174 ammonium sulphate [1] for examiner\u2019s use",
            "4": "0620/2 nov024 2when rain water trickles through rocks, it dissolves some of the minerals present. this water, which is bottled for drinking, is called mineral water. the table shows the ions present in a litre of mineral water. name of ion formula of ionmass of ion present in one litre of water/milligrams calcium ca2+10 chloride cl\u20138 hydrogencarbonate hco3/g4564 sodium na+8 sulphate so 42\u20137 (a)what do you understand by the term ion? [1] (b)which positive ion has the greatest concentration in this sample of water? [1] (c)complete the following equation to show how a calcium ion is formed from a calcium atom. ca /g190/g174        ca2+       +  \u2026 e- [1] (d)when this sample of mineral water is evaporated to dryness, various compoundsare formed. one of these compounds is calcium chloride. suggest the name of twoother compounds which could be formed. compound 1 compound 2 [2] for examiner\u2019s use",
            "5": "0620/2 nov 2002 turn over5 (e)part of the structure of calcium chloride is shown below. use this diagram to work out the simplest formula for calcium chloride. formula [1] (f)complete the following table to show the electrical conductivity of calcium and calcium chloride in the solid and liquid states. put a /g51 if the substance conducts. put a /g55if the substance does not conduct. substance state electrical conductivity calcium solid calcium liquid calcium chloride solid calcium chloride liquid [2] (g)a sample of water was contaminated with clay,  which is insoluble in water. explain with the help of a labelled diagram, how you would separate the clay from the water. [3]cl\u00af cl\u00af cl\u00af cl\u00af ca2+ cl\u00af cl\u00af cl\u00af cl\u00afca2+ ca2+ca2+for examiner\u2019s use",
            "6": "0620/2 nov026 3fluorine, chlorine, bromine and iodine are halogens. (a)complete the table by filling in the blank spaces. halogen colour melting point //g176cboiling point //g176cstate at room temperature fluorine yellow -220 -188 chlorine -101 -35 gas brominereddish- brown-7 +59 iodine +114 solid [4] (b)predict the boiling point of iodine. [1] (c)when chlorine is bubbled through a solution of potassium bromide, the solution turns orange - red. when iodine is mixed with potassium bromide, no colour change occurs. (i)write a word equation for the reaction between chlorine and potassium bromide. [2] (ii)put the elements bromine, chlorine and iodine in order of reactivity. most reactive least reactive [1] (d)state a use of chlorine. [1] for examiner\u2019s use",
            "7": "0620/2 nov 2002 turn over7 (e)in the presence of sunlight, chlorine reacts with methane. hydrogen chloride gas, h /g190 c l, is given off during this reaction. state the type of bonding in a hydrogen chloride molecule. put a ring around the correct answer. covalent ionic metallic weak [1]for examiner\u2019s use",
            "8": "0620/2 nov028 4some organic compounds found in ripe fruits are shown below. ch 3co 2hc h3ch 2ch 2co 2h ch 3ch 2oh ch 3ch 2cho (a)what do you understand by the term organic compound ? [1] (b)which two of the compounds belong to the same homologous series? compound and compound [1] (c)which one of these compounds is an unsaturated hydrocarbon? [1] (d)which one of these compounds is an alcohol? [1] (e)which oneof these compounds can be formed directly by cracking the paraffin fraction from petroleum? [1] (f)compound d burns readily. (i) burning is an exothermic reaction. explain the meaning of the term exothermic . [1] (ii) state the products formed when d burns in excess air. [2] ab c defor examiner\u2019s use c ch h hh",
            "9": "0620/2 nov 2002 turn over9 (iii) name the carbon compound formed when d undergoes incomplete combustion. [1] (g)write down the molecular formula of compound c. [1] (h)calculate the relative molecular mass of compound c. [1] (i)many fruits contain a variety of different coloured compounds. what separation technique can you use to separate these different coloured compounds? [1] forexaminer\u2019s use",
            "10": "0620/2 nov0210 5iron is extracted from the ore, haematite. the iron ore is put in a blast furnace with coke and a current of air is blown through the heated mixture. /k77/k61/k73/k74/k65 /k67/k61/k73/k65/k73 /k72/k61/k77 /k6d/k61/k74/k65/k72/k69/k61/k6c/k73 /k66/k69/k72/k65/k62/k72/k69/k63/k6b /k6c/k69/k6e/k69/k6e/k67 /k61/k69/k72 /k69/k6e /k73/k6c/k61/k67/k6d/k69/k78/k74/k75/k72/k65 /k6f/k66 /k69/k72/k6f/k6e /k6f/k72/k65 /k61/k6e/k64 /k63/k6f/k6b/k65 /k6d/k6f/k6c/k74/k65/k6e /k69/k72/k6f/k6e (a)what do you understand by the term ore? [1] (b)what other raw material needs to be added to the blast furnace? put a ring around the correct answer. cement limewater limestone slag [1]for examiner\u2019suse",
            "11": "0620/2 nov 2002 turn over11 (c)near the bottom of the furnace, iron( iii) oxide is reduced by carbon. fe2o3       +    3c /g174       2fe         +        3co (i) write a word equation for this reaction. [1] (ii) explain what is meant by the term reduction . [1] (d)the table shows the composition of the waste gases leaving the blast furnace. gaspercentage of gas in the mixture carbon dioxide 12 carbon monoxide 24 hydrogen   4 nitrogen 60 (i) the hydrogen in the waste gas is formed by the reaction of hot carbon with water vapour. there is no water in the materials added to the top of the furnace. suggest where this water vapour comes from. [1] (ii) the reaction of hot carbon with water vapour is endothermic. what is meant by the term endothermic ? [1] (e)iron can be converted into steel, which is more resistant to corrosion. (i) describe briefly how iron is converted into steel. [2] (ii) state one use of mild steel. [1] for examiner\u2019suse",
            "12": "0620/2 nov0212 (f)in some conditions, steel corrodes more quickly than in others. the graphs show the rate of corrosion of a particular type of steel under different controlled conditions. (i) how does ph affect the rate of corrosion? [1] (ii) how does temperature affect the rate of corrosion? [1] explain this in terms of moving particles. [2] (iii) the presence of acidic gases in the air may increase the rate of corrosion. state the name and source of one acidic gas found in the air as a result of pollution. name source [2] for examiner\u2019suse /k30 /k30 /k31 /k32/k35/k30/k31/k30/k30/k31/k35/k30/k70/k48 /k36/k2c /k33/k30/ka1/k43 /k70/k48 /k36/k2c /k32/k30/ka1/k43 /k70/k48 /k37/k2c /k33/k30/ka1/k43 /k70/k48 /k37/k2c /k32/k30/ka1/k43 /k74/k69/k6d/k65/k2f/k79/k65/k61/k72/k73/k61/k6d/k6f/k75/k6e/k74 /k6f/k66 /k63/k6f/k72/k72/k6f/k73/k69/k6f/k6e /k28/k75/k6e/k69/k74/k73/k29ph 6, 30oc ph 6, 20oc ph 7, 30oc ph 7, 20oc",
            "13": "0620/2 nov 2002 turn over13 6a student took a sample of seawater and heated it using the apparatus shown below. heatseawatera wate rcondenser (a)what is the name given to the process shown in the diagram? [1] (b)state the name of the piece of apparatus labelled a. [1] (c)explain the function of the condenser. [2] (d)pure water collects in the beaker. (i) state the ph of pure water. [1] (ii) state the boiling point of pure water. [1] for examiner\u2019s use",
            "14": "0620/2 nov0214 (e)the table shows the mass of various compounds obtained when 1 litre of seawater is evaporated. compound formula mass of solid  present / g sodium chloride nac l 28.0 mgc l2 8.0 magnesium sulphatemgso 4 6.0 calcium sulphate caso 4 2.0 potassium chloride kc l calcium carbonate caco 3 1.0 potassium bromide kbr total mass = 45.0 (i) how many grams of magnesium sulphate are present in 180g of solid left by evaporation of seawater? [1] (ii) which compound in the table reacts with acids to release carbon dioxide? [1] (iii) state the name of the compound which has the formula mgc l2. [1] (iv) calcium sulphate contains sulphate ions. describe a test for sulphate ions. test result [3] for examiner\u2019s use",
            "15": "0620/2 nov 2002 turn over15 (f)pure sodium chloride can be electrolysed using the apparatus shown below. heatmolten sodium chlorideelectrodes+\u2013 (i) why does the sodium chloride have to be molten for electrolysis to occur? [2] (ii) state the name of the product formed during electrolysis at the anode (positive electrode) the cathode (negative electrode) [2] (iii) suggest a suitable substance which could be used for the electrodes. [1] for examiner\u2019s use",
            "16": "16 0620/2 nov 2002group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w02_qp_3.pdf": {
            "1": "this question paper consists of 10 printed pages and 2 blank pages. sp (slc/slc) s12144/3 \u00a9cie 2002 [turn overinternational general certificate of secondary education cambridge international examinations chemistry 0620/3 paper 3 october/november session 2002 1hour 15 minutes candidates answer on the question paper. no additional materials are required. time 1 hour 15 minutes instructions to candidates write your name, centre number and candidate number in the spaces at the top of this page. answer all questions. write your answers in the spaces provided on the question paper. information for candidates the number of marks is given in brackets [  ] at the end of each question or part question. a copy of the periodic table is printed on page 12.candidate centre number number candidate name  for examiner\u2019s use 1 2345 total",
            "2": "2 0620/3/o/n/021(a)sulphuric acid is made by the contact process. 2so2(g)   +   o2(g) 2so3(g)   forward reaction is exothermic (i)what are the reaction conditions for the contact process? ... ...[3] (ii) would the yield of sulphur trioxide increase, decrease or stay the same when the temperature is increased? explain your answer. .[2] (iii) describe how sulphur trioxide is changed into concentrated sulphuric acid. ..[2] (b)there are three ways of making salts from sulphuric acid. titr ation using a burette and indicator  precipitation by mixing the solutions and filtering neutr alisation of sulphuric acid using an excess of an insoluble base complete the following table of salt preparations. [4]for examiner\u2019s use method reactant 1 reactant 2 salt titration sulphuric sodium  acid sulphate neutralisation sulphuric zinc  acid sulphate precipitation sulphuric barium  acid sulphate sulphuric copper( ii) copper( ii) acid oxide sulphate",
            "3": "3 0620/3/o/n/02 [turn over(c)the results of an investigation into the action of heat on copper( ii) sulphate-5-water, a blue crystalline solid, are given below. the formula is cuso4.5h2o and the mass of one mole is 250 g a 5.0 g sample of the blue crystals is heated to form 3.2 g of a white powder. with further heating this decomposes into a black powder and sulphur trioxide. (i)name the white powder. ...[1] (ii) what is observed when water is added to the white powder? ...[1] (iii) name the black powder. ...[1] (iv) calculate the mass of the black powder. show your working. ... ..[3] 2manganese is a transition element. it has more than one valency and the metal and its compounds are catalysts. (a) (i) predict three other properties of manganese that are typical of transition elements. ... ...[3] (ii) complete the electron distribution of manganese by inserting one number.2  +  8  +  ..  +  2 [1] (b)it has several oxides, three of which are shown below. manganese( ii) oxide, which is basic. manganese( iii) oxide, which is amphoteric. manganese( iv) oxide, which is acidic. (i)complete the word equation. manganese( ii)   + hydrochloric   \u2192...   +   ... oxide acid... [2] (ii) which, if any, of these oxides will react with sodium hydroxide? ...[1]for examiner\u2019s use",
            "4": "4 0620/3/o/n/02(c)aqueous hydrogen peroxide decomposes to form water and oxygen. 2h2o2(aq)  \u21922h2o(l)   +   o2(g) this reaction is catalysed by manganese( iv) oxide the following experiments were carried out to investigate the rate of this reaction. a 0.1 g sample of manganese( iv) oxide was added to 20 cm3of 0.2 m hydrogen peroxide solution. the volume of oxygen produced was measured every minute. the results of this experiment are shown on the graph. (i)how does the rate of reaction vary with time? explain why the rate varies. ... ...[3] (ii) the following experiment was carried out at the same temperature.0.1 g of manganese( iv) oxide and 20 cm3of 0.4 m hydrogen peroxide sketch the curve for this experiment on the same grid. [2]volume of  oxygen  / cm3 time  / min00for examiner\u2019s use",
            "5": "5 0620/3/o/n/02 [turn over(iii) how would the shape of the graph differ if only half the mass of catalyst had been used in these experiments? ... ..[2] 3the elements in period 3 and some of their common oxidation states are shown below.element na mg al si psc l ar oxidation state +1 +2 +3 +4 \u20133 \u20132 \u20131 0 (a) (i) why do the oxidation states increase from sodium to silicon? ...[1] (ii) after group( iv) the oxidation states are negative and decrease across the period. explain why. ..[2] (b)the following compounds contain two elements. predict their formulae.aluminium sulphide silicon phosphide  [2] (c)choose a different element from period 3 that matches each description. (i)it has a similar structure to diamond. ...[1] (ii) it reacts violently with cold water to form a solution ph = 14. ...[1] (iii) it has a gaseous oxide of the type xo 2, which is acidic. ...[1] (d)the only oxidation state of argon is zero. why it is used to fill light bulbs? [1]for examiner\u2019s use",
            "6": "6 0620/3/o/n/02(e)draw a diagram that shows the arrangement of the valency electrons in the  ionic compound sodium phosphide. use o to represent an electron from sodium. use x to represent an electron from phosphorus. [3] (f)sodium reacts with sulphur to form sodium sulphide. 2na   +   s  \u2192na2s an 11.5 g sample of sodium is reacted with 10 g of sulphur. all of the sodium reacted butthere was an excess of sulphur.   calculate the mass of sulphur left unreacted. (i)number of moles of sodium atoms reacted  =  .[2 moles of na react with 1 mole of s] (ii) number of moles of sulphur atoms that reacted  =  .. (iii) mass of sulphur reacted  =  ...g (iv) mass of sulphur left unreacted  =  .g [4] 4for over 5000 years copper has been obtained by the reduction of its ores. more recently the metal has been purified by electrolysis. (a)copper is used to make alloys. (i)give two other uses of copper. ...[2] (ii) alloys have similar structures to pure metals. give a labelled diagram that showsthe structure of a typical alloy, such as brass. [3]for examiner\u2019s use",
            "7": "7 0620/3/o/n/02 [turn over(b)copper is refined by the electrolysis of aqueous copper( ii) sulphate using copper electrodes. describe the change that occurs at the electrodes. (i)cathode (pure copper) ... ...[1] (ii) anode (impure copper) .. ...[1] (iii) write an ionic equation for the reaction at the cathode. ...[1] (iv) if carbon electrodes are used, a colourless gas is given off at the anode and the electrolyte changes from a blue to a colourless solution. the colourless gas is . .the solution changes into .. . [2] (c)electrolysis and cells both involve chemical reactions and electricity.what is the essential difference between them? [2] (d)copper is an unreactive metal. its compounds are easily reduced to the metal or decomposed to simpler compounds. complete the following equations. (i)...cuo   +      \u2192...cu    +      (ii) copper( ii) hydroxide    \u2192    +     (heat)  (iii) cu(no3)2  \u2192    +        +     (heat) [4]for examiner\u2019s use",
            "8": "8 0620/3/o/n/025alkenes are unsaturated hydrocarbons. they show structural isomerism. alkenes take part in addition reactions and form polymers. (a)structural isomers have the same molecular formula but different structural formulae.give an example of structural isomerism. molecular formula . two structural formulae [3] (b)ethene reacts with each of the following. give the name and structural formula of each product. (i)steam name of product ..structure of product [2] (ii) hydrogen name of product ...structure of product [2]for examiner\u2019s use",
            "9": "9 0620/3/o/n/02(c)alkenes polymerise by addition. (i)explain the term polymerise. ... ...[2] (ii) what is the difference between addition polymerisation and condensation polymerisation? ... ...[2] (iii) poly(dichloroethene) is used extensively to package food. draw its structure. the structural formula of dichloroethene is drawn below. [2] (d)steel may be coated with another metal, eg zinc or chromium, or with a polymer, eg poly(chloroethene), to prevent rusting. (i)suggest a property of poly(chloroethene) that makes it suitable for this purpose. ...[1] (ii) explain why the steel will rust when the protective coating of chromium or polymeris broken. ...[1] (iii) when the protective layer of zinc is broken, the steel still does not rust.suggest an explanation. ... ..[2]c ccl clh hfor examiner\u2019s use",
            "10": "10 0620/3/o/n/02blank page",
            "11": "11 0620/3/o/n/02blank page",
            "12": "12 0620/3/o/n/02groupdata sheet the periodic table of the elements 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89               \u20209 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series \u202090-103 actinoid series"
        },
        "0620_w02_qp_5.pdf": {
            "1": "time 1 hour 15 minutes instructions to candidates write your name, centre number and candidate number in the spaces at the top of this page. answer allquestions. write your answers in the spaces provided on the question paper. information for candidates the number of marks is given in brackets [ ] at the end of each question or part question. practical notes are provided on page 8.international general certificate of secondary educationcambridge international examinations chemistry 0620/5 paper 5 practical test october/november session 2002 1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in instructions to supervisors this question paper consists of 7 printed pages and 1 blank page. (nh) s16055/2 \u00a9 cie 2002 [turn overcandidate centre number number candidate name  ",
            "2": "2 0620/5 o/n/021 you are going to investigate the reactions of four different metals. copper, magnesium, iron and zinc will be used. read allthe instructions below carefully before starting the experiments. instructionsexperiment 1by using a measuring cylinder, pour 15 cm 3of dilute sulphuric acid into the boiling tube provided. measure the initial temperature of the acid and record it in the table. add the 1 g sample of zinc powder to the acid in the boiling tube and stir the mixture with thethermometer. record the maximum temperature reached and any observations in the table. remove the thermometer and rinse with water. experiment 2 repeat experiment 1, using 1 g of iron instead of zinc. record the maximum temperature reached and any observations in the table. experiment 3 repeat experiment 1, using the 0.5 g sample of magnesium. test the gas given off with a lighted splint. experiment 4 repeat experiment 1, using 1 g of copper. record all results in the table.for examiner\u2019s use",
            "3": "3 0620/5 o/n/02 [turn overtable of results [10] (a)use your results and observations to answer the following questions. (i)which metal is most reactive with sulphuric acid? ...[1] (ii) give tworeasons why you chose this metal. 1.  ... 2. ...[ 2] (iii) name the gas given off in experiment 3. ...[1]for examiner\u2019s use experiment 1 2 3 4metal zinc iron magnesium copperobservationstemperature of acid / \u00b0c initial maximum",
            "4": "4 0620/5 o/n/02you are now going to investigate the reaction between magnesium and aqueous copper( ii) sulphate. experiment 5 rinse the thermometer with water at room temperature. by using a measuring cylinder pour 5c m3of aqueous copper( ii) sulphate into a test-tube. measure the initial temperature of the solution and record it in the table below. add the 0.2 g sample of magnesium powder to the test-tube and record the maximum temperature reached. record all of your observations in the table. table of results (b)how do your observations show that the reaction of magnesium with aqueous copper( ii) sulphate is exothermic? ..[1] (c)what type of exothermic reaction occurs when magnesium is added to aqueouscopper( ii) sulphate? ..[1] (d)use your results from experiments 1 to 5 to put the four metals in order of reactivity. least reactive. .. .. most reactive.[1]initial temperature of aqueous copper( ii) sulphate... \u00b0c maximum temperature reached when magnesium added ... \u00b0c [2] observations when magnesium was added to aqueous copper( ii) sulphate .. ...[3]for examiner\u2019s use",
            "5": "5 0620/5 o/n/02 [turn over2 you are provided with liquid fand liquid g. carry out the following tests on fandg, recording all of your observations in the table. conclusions must notbe written in the table.for examiner\u2019s use observations tests (a) (i) place a little of liquid fin a test- tube and describe its smell and colour. (ii) place a little of liquid gin a test-tube and describe its smelland colour. (b) (i) by using a teat pipette addabout 1 cm 3of liquid fto a crystal of iodine provided in atest-tube. stopper and shakethe test-tube. keep for (b)(ii). (ii) add about 1 cm 3ofgto the other crystal of iodine provided.stopper and shake the test-tube. add this mixture to the mixture in(b)(i)  ...[2] ... ...[1] ... ...[2] ... ...[2] ...[1]",
            "6": "6 0620/5 o/n/02(f)what type of substance is liquid f? .. ..[2] (g)identify oneion present in liquid g. ..[1]for examiner\u2019s use observations tests (c) (i) using a teat pipette transfer a few drops of fto a dry watch glass. touch the liquid with alighted splint. (ii) repeat (c)(i) using liquid g. (d) to about 1 cm 3of liquid g, add a few drops of dilute nitric acid and thenaqueous lead( ii) nitrate. (e) to about 1 cm3of liquid g, add a few drops of dilute nitric acid followed byaqueous silver nitrate ...[2] ... ...[1] ... ...[2] ... ...[2]",
            "7": "7 0620/5 o/n/02blank page",
            "8": "8 0620/5 o/n/02notes for use in qualitative analysis anion test add dilute acid acidify with dilute nitric acid, then add aqueous silver nitrate acidify with dilute nitric acid, then add aqueous lead( ii) nitrate add aqueous sodium hydroxidethen aluminium foil; warm carefully acidify with dilute nitric acid, then add aqueous barium nitratetest result effervescence, carbon dioxide produced white ppt. yellow ppt. ammonia produced white ppt.carbonate (co 32\u2013) chloride (c l\u2013) [in solution] iodide ( i\u2013) [in solution] nitrate (no3\u2013) [in solution] sulphate (so42\u2013) [in solution]test for anions test for aqueous cations test for gasescation aluminium (a l3+) ammonium (nh 4+) calcium (ca2+) zinc (zn2+)copper (cu2+) iron( ii) (fe2+) iron( iii) (fe3+)effect of aqueous sodium hydroxidewhite ppt., soluble in excess giving a colourless solution ammonia produced on warming white ppt., insoluble in excess light blue ppt., insoluble in excess green ppt., insoluble in excess red-brown ppt., insoluble in excess white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excessgiving a colourless solutioneffect of aqueous ammonia white ppt., insoluble in excess \u2013 no ppt., or very slight white ppt.light blue ppt., soluble in excess giving a dark blue solution green ppt., insoluble in excess red-brown ppt., insoluble in excess gas test and test result turns damp litmus paper blueturns lime water milky bleaches damp litmus paper \u2018pops\u2019 with a lighted splintrelights a glowing splintammonia (nh 3) carbon dioxide (co 2) chlorine (c l2) hydrogen (h 2) oxygen (o 2)"
        },
        "0620_w02_qp_6.pdf": {
            "1": "time 1 hour instructions to candidates write your name, centre number and candidate number in the spaces at the top of this page. answer allquestions. write your answers in the spaces provided on the question paper. information for candidates the number of marks is given in brackets [ ] at the end of each question or part question.international general certificate of secondary education cambridge international examinations chemistry 0620/6 paper 6 alternative to practical october/november session 2002 1hour candidates answer on the question paper. no additional materials are required. this question paper consists of 11 printed pages and 1 blank page. (nh/pw) s12141/3 \u00a9 cie 2002 [turn overcandidate centre number number candidate name  for examiner\u2019s use ",
            "2": "2 0620/6 o/n/021a student investigated the neutralisation of dilute hydrochloric acid, using an excess of calcium carbonate. step 1 excess calcium carbonate was added to hydrochloric acid. step 2. excess calcium carbonate was removed from the solution. step 3. the solution of calcium chloride was tested with indicator paper. (a)identify the pieces of apparatus labelled: a b c[3] (b)what does the term excess mean? [1] (c)suggest the ph value of the solution of calcium chloride. ..[1]for examiner\u2019s use b dilute hydrochloric acid c solution of calcium chloride excess calcium carbonatea calcium carbonate",
            "3": "3 0620/6 o/n/02 [turn over2hydrogen chloride gas is strong-smelling, denser than air and soluble in water. a sample of hydrogen chloride gas can be prepared by adding concentrated sulphuric acid to sodiumchloride. study the diagram of the apparatus used. (a)fill in the boxes to show the chemicals used. [2] (b)identify and explain twomistakes in the diagram. mistake 1... ..[2] mistake 2... ..[2] (c)state oneprecaution that should be taken when carrying out this experiment. .. ..[1]waterfor examiner\u2019s use",
            "4": "4 0620/6 o/n/023dilute nitric acid was added to a large amount of magnesium carbonate in a conical flask as shown. the flask was placed on a balance and the mass of the flask and contents recorded every minute. the results are shown in the table. (a)plot the results on the grid and draw a smooth line graph. [3]260.0cotton wool nitric acid magnesium carbonate balancefor examiner\u2019s use time / min 0 1 2 3 4 5 6 260.0 257.9 256.8 256.6 255.8 255.6 255.6mass of flask and contents / g",
            "5": "5 0620/6 o/n/02 [turn over(b)which result appears to be inaccurate? why have you selected this result? .. ..[2] (c)why does the mass of the flask and contents decrease? ..[1] (d)suggest the purpose of the cotton wool. ..[1] (e)at what time did the reaction finish? ..[1] (f)on the grid, sketch the graph you would expect if the experiment were repeated using nitric acid at a higher temperature. [2]256 255 0260 259 258 257 2 3 4 5 1 6 time/minsmass of flask and contents/gfor examiner\u2019s use",
            "6": "6 0620/6 o/n/024an investigation was carried out on the reactions of four different metals. equal masses of copper, magnesium, iron and zinc were used. experiment 1 a 15 cm3sample of dilute sulphuric acid was added to each of four boiling tubes. the initial temperature of the acid was measured. zinc was added to the first tube, iron to the secondtube, magnesium to the third tube and copper to the fourth tube. the maximum temperature reached in each tube was measured and any observations were recorded in the table. (a)use the thermometer diagrams to complete the results table. table of results [6]for examiner\u2019s use metal added magnesium copperironzincgas given offslowly gas given off very slowly gas given off rapidly: lightedsplint pops no visible reactiontemperature of acid/\u00b0c initial maximumobservationstemperature difference/\u00b0c 25 20 15 25 20 15 25 20 15 25 20 1525 20 15 25 20 15 85 80 75 25 20 15",
            "7": "7 0620/6 o/n/02 [turn overuse your results and observations to answer the following questions. (i)which metal is most reactive with sulphuric acid? ...[1] (ii)give tworeasons why you chose this metal. 1.  ... 2. ...[ 2] (iii)name the gas given off. ...[1] the reaction between magnesium and aqueous copper( ii) sulphate was then investigated. experiment 2 a 5 cm3sample of aqueous copper( ii) sulphate was measured into a test-tube. the initial temperature of the solution was measured.magnesium powder was added to the test-tube and the maximum temperature reached was measured. use the thermometer diagrams to complete the results table. table of results [2]for examiner\u2019s use 25 20 15 45 40 35initial temperature of aqueous copper( ii) sulphate maximum temperature reached after magnesium added",
            "8": "8 0620/6 o/n/02(b)how do your observations show that the reaction of magnesium with aqueous copper( ii) sulphate is exothermic? ..[1] (c)what type of exothermic reaction occurs when magnesium is added to aqueouscopper( ii) sulphate? ..[1] (d)use your results from experiments 1 and 2 to put the four metals in order of reactivity. least reactive.  most reactive.[1]for examiner\u2019s use",
            "9": "9 0620/6 o/n/02 [turn over5two liquids, f and g, were tested. the tests and some of the observations are in the following table. gwas an aqueous solution of a metal iodide. complete the observations in the table. (f)what type of substance is liquid f? .. ..[2]for examiner\u2019s use tests (a) (i) appearance of liquid f. (ii) appearance of liquid g. (b) (i) about 1 cm3of liquid fwas added to a crystal of iodine. the test-tube was shaken. (ii) about 1 cm3of liquid gwas added to a crystal of iodine.the test-tube was shaken. the mixture from (b)(i) was added to the mixture in (b)(ii). (c)a few drops of fwere placed on a dry watch glass.the liquid was touched with a lighted splint. (d)to about 1 cm 3of liquid gwas added a few drops of dilute nitricacid followed by aqueous lead( ii) nitrate. (e)to about 1 cm3of liquid gwas added a few drops of dilute nitricacid followed by aqueous silvernitrate. [2]  [2]  [2]colourless smells like petrol colourless no smell purple solution red/brown solution two layers formedobservations",
            "10": "10 0620/6 o/n/026the following paragraph was taken from a student\u2019s notebook. to make potassium chloride 25.0 cm3of aqueous potassium hydroxide were placed in a flask and a few drops of indicator were added. dilute hydrochloric acid was added to the flask until the indicator changed colour. the volume of acid used was 19.0 cm3. (a)what piece of apparatus should be used to measure the aqueous potassiumhydroxide? ..[1] (b) (i) name a suitable indicator that could be used. ...[1] (ii) the indicator colour would change from..to.. [2] (c)which solution was more concentrated? explain your answer. [2] (d)how could pure crystals of potassium chloride be obtained from this experiment? [3]for examiner\u2019s use",
            "11": "11 0620/6 o/n/027f astgrow fertiliser fertilisers are used to increase the growth of plants. fertilisers have to dissolve in water if they are to be used by plants. plan an experiment to find the solubility, in g/100 cm3, of fastgrow fertiliser at 30 \u00b0c. .. ..[6]for examiner\u2019s use",
            "12": "12 0620/6 o/n/02blank page"
        }
    },
    "2003": {
        "0620_s03_qp_1.pdf": {
            "1": "this document consists of 18printed pages and 2blank pages. br (pw) s41678/1 \u00a9 cie 2003 [turn overcambridge international examinations international general certificate of secondary education chemistry 0620/01 paper 1  multiple choice may/june 2003 45 minutes additional materials: multiple choice answer sheet soft clean eraser soft pencil (type b or hb is recommended) read these instructions first write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid.write your name, centre number and candidate number on the answer sheet in the spaces providedunless this has been done for you. there are forty questions on this paper. answer allquestions. for each question, there are four possible answers a,b,c, and d. choose the oneyou consider correct and record your choice in soft pencil on the separate answer sheet. read the instructions on the answer sheet very carefully.each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet.a copy of the periodic table is printed on page 20.",
            "2": "2 0620/01/m/j/031the diagram shows how to obtain pure water from seawater. where do water molecules lose energy? 2a solid metal is heated until it turns to vapour.the graph shows the temperature of the metal during this process.which part of the graph shows the melting of the metal? 3some chemical compounds are purified by recrystallisation.what can be used to test the purity of the crystals? amelting point bcolour of crystals csize of crystals dsolubility2200 500 timetemperature/ \u00b0c abcd 25water out abc dseawater pure water bunsen flamewater in",
            "3": "3 0620/01/m/j/03 [turn over4what could be the melting point and boiling point of water containing a dissolved impurity? 5which number in the table is \u20131? 6what is the electronic structure of an atom with a proton number 5 and a nucleon number 11? a1, 8, 2 b2, 8, 1 c2, 3 d3, 2 7what changes when an ion is made from an atom? athe number of electrons only bthe number of neutrons only cthe number of protons only dthe number both of protons and of neutrons 8strontium, sr, is a metal that forms an ionic chloride src l2. sulphur, s, is a non-metal that forms a covalent chloride sc l2. which compound is likely to have the higher melting point (m.p.) and which is more soluble in water?melting point / oc boiling point / oc a +3 96 b +3 104 c \u20133 96 d \u20133 104 particle charge relative mass electron ab neutron c 1 proton d 1 more soluble higher m.p. in water a srcl2srcl2 b srcl2scl2 c scl2srcl2 d scl2scl2",
            "4": "4 0620/01/m/j/039the relative atomic mass of oxygen is 16 and that of hydrogen is 1. this means that \u2026(i)\u2026 of oxygen has the same mass as \u2026(ii)\u2026 of hydrogen.which words correctly complete the gaps? 10the diagram shows a model of a molecule containing carbon, hydrogen and oxygen. how many atoms of each element are in the molecule? 11water is formed when 48 g of oxygen combine with 6 g of hydrogen. what mass of oxygen combines with 2 g of hydrogen? a12 g b16 g c96 g d144 ggap (i) gap (ii) a an atom thirty-two molecules b an atom eight molecules ca molecule sixteen atoms da molecule eight atoms carbon hydrogen oxygen a 162 b 251 c 261 d 621",
            "5": "5 0620/01/m/j/03 [turn over12the diagram shows how aluminium is manufactured by electrolysis. what are the anode and cathode made of? 13a student sets up the apparatus shown. the bulb does not light. after the student adds substance xto the water, the bulb lights. what is x? acalcium carbonate bcarbon ccopper( ii) sulphate dethanolwaterelectrodebulbanode (+ve) cathode (\u2013ve) molten aluminiumaluminium oxide dissolved in cryolite anode cathode aaluminium aluminium baluminium graphite c graphite aluminium d graphite graphite",
            "6": "6 0620/01/m/j/0314the following elements have radioactive isotopes. which element is used as a source of energy because of its radioactivity? acarbon bhydrogen ciodine duranium 15when hydrogen is passed over a heated metal oxide, the metal and steam are formed. what happens to the hydrogen and to the metal oxide?hydrogenmetal oxide excess of hydrogen burning heat hydrogen metal oxide aoxidised oxidised boxidised reduced creduced oxidised dreduced reduced",
            "7": "7 0620/01/m/j/03 [turn over16when hydrated copper( ii) sulphate is heated in the apparatus shown, solid xand liquid yare produced. which changes are noticed when liquid yis added to cold solid x?cold water liquid yheathydrated copper(ii) sulphate colour change heat change a blue to white heat given out b blue to white heat taken in c white to blue heat given out d white to blue heat taken in",
            "8": "8 0620/01/m/j/0317a solution of hydrogen peroxide releases oxygen slowly at room temperature. hydrogen peroxide \u2192water + oxygen the diagrams show the effect of adding blood to the solution. what could be the reason for the observed change? ablood contains an enzyme. bblood contains water. cthe hydrogen peroxide becomes more concentrated. dthe hydrogen peroxide is neutralised by blood.before adding blood after adding bloodblood bubbles produced slowlybubbles produced rapidly",
            "9": "9 0620/01/m/j/03 [turn over18a liquid xreacts with solid yto form a gas. which two diagrams show suitable methods for investigating the speed of the reaction? a1 and 3 b1 and 4 c2 and 3 d2 and 4 19which substance does notform copper( ii) sulphate with warm, dilute sulphuric acid? acopper bcopper( ii) carbonate ccopper( ii) hydroxide dcopper( ii) oxidebalancestopper x y1 balancecotton wool x y2 stopper x y3 x y4 cotton wool",
            "10": "10 0620/01/m/j/0320which test method and gas are correctly linked? 21water is added to a test-tube containing dilute sulphuric acid of ph 4. what could be the ph of the resulting solution? a8 b6 c4 d2 22magnesium, on the left of period two of the periodic table, is more metallic than chlorine on the right of this period. why is this?magnesium has afewer electrons. bfewer protons. cfewer full shells of electrons. dfewer outermost electrons. 23an inert gas xis used to fill weather balloons. which descriptions of xare correct?test method gas a a lighted splint oxygen b a glowing splint hydrogen cdamp litmus paper chlorine d limewater ammonia number of outer electrons in atoms of xstructure of gas x a 2 single atoms b 2 diatomic molecules c 8 single atoms  d 8 diatomic molecules",
            "11": "11 0620/01/m/j/03 [turn over24a student is asked to complete two sentences. metallic and non-metallic elements are classified in the \u2026(i)\u2026 this can be used to \u2026(ii)\u2026 the properties of elements. which words correctly complete the gaps? 25which material is an alloy that contains a non-metallic element? abrass bhaematite cmanganese dsteel 26the table gives information about the reactivity of three metals p , q and r. what is the order of reactivity of p , q and r?gap (i) gap (ii) a periodic table measure b periodic table predict creactivity series measure dreactivity series predict metal reaction with air reaction with steam reaction with dilute hydrochloric acid p burns with sparks forms an oxide forms hydrogen q slowly forms an oxide no reaction no reaction r slowly forms an oxide no reaction forms hydrogen most reactive \uf8e7\uf8e7\uf8e7\u2192 least reactive a pq r b pr q c qrp d rqp",
            "12": "12 0620/01/m/j/0327the bodies of aircraft are often made using aluminium. which twoproperties of aluminium make it suitable for this purpose? 28which raw materials are used in the manufacture of iron? abauxite and lime bbauxite and limestone chaematite and lime dhaematite and limestone 29in a car industry, approximately 45000 litres of water are required to produce a single car.this water does not need to be very pure.which purification methods would be suitable and economic to use?property 1 property 2 agood conductor of electricity good conductor of heat bgood conductor of electricity strong cgood conductor of heat low density dstrong low density chlorinated distilled a \u2713\u2713 b \u2713\u2717 c \u2717\u2713 d \u2717\u2717",
            "13": "13 0620/01/m/j/03 [turn over30the pie-chart shows the composition of air. what are the gases in parts 1, 2 and 3 of the pie-chart? 31a steel works and a chemical works are built near to a city. the limestone buildings in the city begin to crumble. which gas is most likely to cause this damage? acarbon dioxide bcarbon monoxide coxygen dsulphur dioxide123 12 3 anitrogen other gases oxygen bnitrogen oxygen other gases coxygen other gases nitrogen doxygen nitrogen other gases",
            "14": "14 0620/01/m/j/0332which methods can be used to prevent the rusting of an iron girder of a bridge? 33a student heats a mixture of ammonium chloride and calcium hydroxide. she tests the gas given off with damp red litmus paper. what is the name of the gas and the final colour of the litmus paper? 34a newspaper article claims that carbon dioxide is formed as follows. 1 during respiration2 when calcium carbonate reacts with hydrochloric acid3 when methane burns in air   which statements are correct? a1, 2 and 3 b1 and 2 only c1 and 3 only d2 and 3 onlycoat it with grease electroplate it paint it a \u2713\u2713 \u2713 b \u2713\u2713 \u2717 c \u2717\u2713 \u2713 d \u2717\u2717 \u2713 gas colour aammonia blue bammonia red c chlorine red d chlorine white",
            "15": "15 0620/01/m/j/03 [turn over35the diagram shows how the ph of an industrial waste changes when substance xis added to it. what is substance x? acoal blime csalt dwater 36the diagram shows a model of an organic compound. what is the name of this compound? aethane bethanoic acid cethanol dethenekey carbon atom hydrogen atom7 ph before x is addedafter x is added",
            "16": "16 0620/01/m/j/0337bitumen is a substance obtained from the fractional distillation of petroleum. what are the boiling points and the sizes of the molecules in bitumen? 38which hydrocarbons in the table are members of the same homologous series? a1 and 2 b1 and 3 c3 and 4 d1, 2, 3 and 4boiling points sizes of molecules a high large b high small c low large d low small hydrocarbon 1 2 3 4 state at room temperaturegas gas liquid liquid reaction with oxygen burns burns burns burns   aqueous reaction decolourisesno reactiondecolourisesno reactionwith bromine bromine bromine ",
            "17": "17 0620/01/m/j/0339which of the molecules shown can be polymerised? 40which conditions are necessary to ferment sugar into ethanol?h c hh h h c c hhh hh h c chho h oa b c dh c c chhh h h yeast temperature/ \u00b0c aabsent 30 babsent 70 cpresent 30 dpresent 70",
            "18": "18 0620/01/m/j/03blank page",
            "19": "19 0620/01/m/j/03 [turn overblank page",
            "20": "20 0620/01/m/j/03groupdata sheet the periodic table of the elements 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89               \u20209 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series \u202090-103 actinoid series"
        },
        "0620_s03_qp_2.pdf": {
            "1": "for examiner\u2019s use 1 2 3 4 5 6 totalcambridge international examinations  international general certificate of secondary education chemistry 0620/02 paper 2 may/june 2003 1 hour  candidates answer on the question paper. no additional materials requiredcentre number candidate number name read these instructions first write your name, centre number and candidate number in the spaces provided at the top of this page. write in dark blue or black pen in the spaces provided on the question paper.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction fluid. answer allquestions. the number of marks is given in brackets [  ] at the end of each question or part question. a copy of the periodic table is printed on page 16. this document consists of 16printed pages. sp (sc) s33034/4 \u00a9 cie 2003 [turn overif you have been given a label, look at the details. if any details are incorrect ormissing, please fill in your correct detailsin the space given at the top of this page. stick your personal label here, if provided.",
            "2": "2 0620/02 m/j/031the diagram shows part of the periodic table. (a)answer these questions using only the elements shown in the diagram. write down the symbol for an element which (i)is a transition metal. (ii) forms an acidic oxide. (iii) has six electrons in its outer shell. (iv) has a giant covalent structure. (v) reacts rapidly with water. (vi) has a higher proton (atomic) number than iron. [6]for examiner\u2019s use li na fe cu zncnof n ehe s cl brar kr ki ii iii iv v vi vii 0",
            "3": "3 0620/02 m/j/03 [turn over(b)some uses of some non-metallic elements are show below. draw lines between the boxes to link the elements to their correct uses.the first one has been done for you. element use [4] (c)the structures of some halogen compounds are shown below. (i)describe the type of bonding in compound a. ... (ii)state the simplest formula for compound c. ... (iii) explain why compound bdoes not conduct electricity when solid but does conduct when molten. ... ...[4]clna+ clcli ab ccl\u2013na+ cl\u2013na+cl\u2013 na+cl\u2013na+br ff ff fas a lubricant heliumin balloons carbon (graphite)to kill bacteria in water purificationchlorinein oxygen tents in hospitalsargonin light bulbs oxygenfor examiner\u2019s use",
            "4": "4 0620/02 m/j/032a student investigates the reaction between zinc and hydrochloric acid.  the hydrochloric acid is in excess. the student uses the apparatus shown in the diagram.  (a)what should the student do to start the reaction?  ..[1] (b)the student reads the volume of gas in the syringe every minute.  the results are shown in the table. (i)plot the results on the grid on page 5.gas syringehydrogengas hydrochloric acidzinc powersmall testtube held bya piece ofcottonfor examiner\u2019s use time in minutes 0 1 2 3 4 5 6 7 volume of gas in cm30 2 33 54 55 05 35 55 5",
            "5": "5 0620/02 m/j/03 [turn over(ii) draw the best curve through the points. (iii) explain why the volume of gas stays the same after six minutes. ... ...[5] (c)the student does the experiment again. the only difference is that the student uses warm, rather than cold, hydrochloric acid. on the grid, draw the shape of the graph you would expect for theexperiment with the warm hydrochloric acid. [2] .01102030405060 234567 time / minvolume of gas / cm3for examiner\u2019s use",
            "6": "6 0620/02 m/j/03(d) (i) balance the equation for the reaction between zinc and hydrochloric acid. zn     + \u2026hcl \u2192 zncl2+       h2 (ii)name the compound which has the formula znc l2. ... (iii)calculate the relative formula mass of znc l2. [3] (e)zinc is an element. state the meaning of the term element . .. ..[1]for examiner\u2019s use",
            "7": "7 0620/02 m/j/03 [turn over3the states of matter are solid, liquid and gas. the diagram below shows how the molecules are arranged in these three states. (a)state the name given to the change of state labelled (i) a ... (ii) b ... (iii) c  [3] (b)which one of the following best describes the movement of molecules in the liquid state? tick one box. the molecules are not moving from place to place. the molecules are sliding over each other.the molecules are moving freely. [1] (c)which of the changes a,borc, is endothermic? explain your answer. .. ..[2]bmelting cafor examiner\u2019s use",
            "8": "8 0620/02 m/j/03(d)choose from the following list of substances to answer the questions below. bromine chlorine iron mercury sodium chloride sulphur name a substance which is (i)a gas at room temperature. .. (ii) a non-metallic liquid at room temperature. ... (iii) a compound which is a solid at room temperature. ... [3] (e)a student set up the apparatus shown in the diagram below.  the white solid is formed because the molecules of hydrogen chloride gas and ammonia gas move at random throughout the tube and eventually react with each other. (i)state the name given to this random movement of molecules. ... (ii) state the name of the white solid formed at x. ... (iii) suggest why the white solid is formed towards one end of the tube and not in themiddle. ... ...[3] (f)what type of chemical reaction takes place when ammonia reacts with hydrochloric acid? ..[1]xglass tube rubber bung cotton wool soaked in ammonia solutioncotton wool soaked in concentrated hydrochloric acidfor examiner\u2019s use",
            "9": "9 0620/02 m/j/03 [turn over(g)the diagram below shows a simple apparatus that can be used for measuring the melting point of a solid. the liquid in the beaker is heated slowly and the temperature at which the solid b meltsis recorded.  (i)state the name of the piece of apparatus labelled a. ... (ii) solid bmelted at 155 oc.  why would water notbe a suitable liquid to put in the beaker when using this apparatus to find the melting point of solid b? ... ... (iii) suggest why the liquid needs to be kept stirred. ..[3]a small tube heatstirrer liquidsolid bfor examiner\u2019s use",
            "10": "10 0620/02 m/j/034catalytic cracking is carried out by oil companies to produce high grade petrol.  the process is carried out using an aluminium oxide catalyst. the reaction is a type of thermal decomposition. (a)explain the meaning of (i)thermal decomposition. .. (ii) catalyst. ... ..[2] (b)a typical \u2018cracking\u2019 reaction is c 10h22\u2192 c8h18+      c2h4 state the name of the unsaturated compound in this equation. ..[1] (c)the table shows some of the products obtained by cracking 100g of different \u2018fractions\u2019 under the same conditions.  (i)which \u2018fraction\u2019 is the best source of fuel for cars? ... (ii)calculate the amount of paraffin \u2018fraction\u2019 needed to make 600g of methane.for examiner\u2019s use products obtained / g per 100g of \u2018fraction\u2019 cracked \u2018fraction\u2019 cracked hydrogen methane ethene petrol ethane 10 5 75 2 paraffin 1 15 30 23 diesel 0 6 20 17",
            "11": "11 0620/02 m/j/03 [turn over(iii)complete the equation for the cracking of ethane to produce hydrogen and ethene.  c2h6\u2192 \u2026\u2026\u2026\u2026\u2026\u2026    +    \u2026\u2026\u2026\u2026\u2026\u2026 [4] (d)ethene can be polymerised to form poly(ethene). (i)complete the equation below to show the structure of two units in the poly(ethene) molecule.  (ii) state the name given to this type of polymerisarion. ...[2] 5a precipitate may be formed when two aqueous solutions are mixed. the colour of these precipitates may be used to identify particular aqueous ions. (a)complete the following table.   [8]h hchhch h chhc + \u2192for examiner\u2019s use solution to be added to  ion under test test for the ion colour of precipitate iron( ii) iodide chloride sulphate",
            "12": "12 0620/02 m/j/03(b)when a solution of iron( iii) chloride is added to a solution of sodium hydroxide, a precipitate of iron( iii) hydroxide is formed and sodium chloride remains in solution. explain how you would obtain a pure dry sample of sodium chloride from this mixture. y ou may use diagrams to help with your explanation. [3] (c)sodium chloride and iron( iii) hydroxide are both compounds. explain the meaning of the term compound . .. . [2] (d)molten sodium chloride can be electrolysed using graphite electrodes.predict the products of this electrolysis (i)at the anode .. (ii) at the cathode  .. [2]sodium chloride solution iron(iii) hydroxidefor examiner\u2019s use",
            "13": "13 0620/02 m/j/03 [turn over6this question is about different metals. the list below shows part of the metal reactivity series . potassium more reactive magnesiumaluminiumzincironcopper less reactive (a)from this list, choose a metal which is extracted using electrolysis. ..[1] (b)two thousand years ago, people were able to extract iron  and copper from their ores.they were not able to extract aluminium. suggest why they were not able to extract aluminium from its ore. .. ..[1] (c)uranium is between magnesium and zinc in the reactivity series. equal sized strips of magnesium, uranium and zinc were placed in hydrochloric acid. the hydrochloric acid was the same concentration.  the results are shown in the table. (i)complete the result for uranium and hydrochloric acid. (ii) uranium has several isotopes which are radioactive. one of these isotopes is uranium \u2013 235 ( 235u). what do you understand by the term isotopes? ... ... (iii) state oneuse of uranium \u2013235. ...[3]for examiner\u2019s use metal observations on adding to hydrochloric acid magnesium many bubbles of gas produced very rapidly and magnesium dissolves quickly uranium zinc a few bubbles produced at a steady rate and zinc dissolves slowly",
            "14": "14 0620/02 m/j/03(d)metals high in the reactivity series react readily with oxygen. name the compound formed when magnesium reacts with oxygen. ..[1] (e)copper is alloyed with tin to make bronze. (i)state what is meant by the term alloy. ... ... (ii) suggest why metals are often used in the form of alloys. .[2] (f)zinc can be extracted by heating zinc oxide with carbon. zno     +       c \u2192 zn      +       co explain why carbon is a reducing agent (reductant) in this reaction. ..[1] (g)iron is used as a catalyst in the haber process for making ammonia. 3h 2+     n22nh3 (i)what does the sign          mean? ... (ii) what is the approximate percentage of nitrogen in the air? ...[2]for examiner\u2019s use",
            "15": "15 0620/02 m/j/03 [turn over(h)magnesium is in group ii of the periodic table. (i)draw a diagram to show the electronic structure of magnesium. (ii) explain what happens to the magnesium atom when it reacts and forms a magnesium ion.  ...[3]for examiner\u2019s use",
            "16": "16 0620/02 m/j/03groupdata sheet the periodic table of the elements 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89               \u20209 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series \u202090-103 actinoid series"
        },
        "0620_s03_qp_3.pdf": {
            "1": "this document consists of 12printed pages. sp (nf/jg) s33032/4 \u00a9 cie 2003 [turn overcambridge international examinations international general certificate of secondary education chemistry 0620/03 paper 3 may/june 2003 1 hour 15 minutes candidates answer on the question paper. no additional materials required. read these instructions first write your name, centre number and candidate number in the spaces provided at the top of this page. write in dark blue or black pen in the spaces provided on the question paper.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction fluid. answer allquestions. the number of marks is given in brackets [  ] at the end of each question or part question. a copy of the periodic table is provided on page 12.centre number candidate number name for examiner\u2019s use if you have been given a label, look at the details. if any details are incorrect ormissing, please fill in your correct detailsin the space given at the top of this page. stick your personal label here, if provided.1 2 3 4 5 total",
            "2": "2 0620/03/m/j/031no one knows where iron was first isolated. it appeared in china, the middle  east and in africa. it was obtained by reducing iron ore with charcoal. (a)complete the following equation. fe2o3+       c \u2192 ...  +   iron ore charcoal [2] (b)in 1705 abraham darby showed that iron ore could be reduced using coke in a blastfurnace. (i)the temperature in the furnace rises to 2000 \u00b0c. write an equation for theexothermic reaction that causes this high temperature. ... (ii) in the furnace, the ore is reduced by carbon monoxide. explain how this is formed. ... ...[3] (c)the formation of slag removes an impurity in the ore. write a word equation for the formation of the slag. ..[2]waste gases raw materials firebrick lining air slag molten ironfor examiner\u2019s use",
            "3": "3 0620/03/m/j/03 [turn over(d)stainless steel is an alloy of iron. it contains iron, other metals and about 0.5% of carbon. (i)state a use of stainless steel. ... (ii) name a metal, other than iron, in stainless steel. ... (iii) the iron from the blast furnace is impure. it contains about 5% of carbon and otherimpurities, such as silicon and phosphorus. describe how the percentage ofcarbon is reduced and the other impurities are removed. ... ..[6] (e)one of the methods used to prevent iron or steel from rusting is to electroplate it with another metal, such as tin. complete the following. the anode is made of ... . the cathode is made of . .the electrolyte is a solution of ... . [3]for examiner\u2019s use",
            "4": "4 0620/03/m/j/032calcium and other minerals are essential for healthy teeth and bones. tablets can be taken to provide these minerals. (a)boron is a non-metal with a macromolecular structure. (i)what is the valency of boron? ... (ii) predict twophysical properties of boron. ... ... (iii) name another element and a compound that have macromolecular structures.element \u2026\u2026\u2026\u2026\u2026\u2026\u2026..compound \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 (iv) sketch the structure of one of the above macromolecular substances. [7]healthy bones each tablet contains calcium magnesiumzinccopperboronfor examiner\u2019s use",
            "5": "5 0620/03/m/j/03 [turn over(b)describe the reactions, if any, of zinc and copper( ii) ions with an excess of aqueous sodium hydroxide. (i)zinc ions addition of aqueous sodium hydroxide . ... excess sodium hydroxide .. ... (ii) copper( ii) ions addition of aqueous sodium hydroxide . ... excess sodium hydroxide .. ...[4] (c)each tablet contains the same number of moles of caco3and mgco3. one tablet reacted with excess hydrochloric acid to produce 0.24 dm3of carbon dioxide at r.t.p. caco3+  2hc l\u2192cacl2+  co2+  h2o mgco3+  2hc l\u2192mgcl2+  co2+  h2o (i)calculate how many moles of caco3there are in one tablet. number of moles co2= .. number of moles of caco3and mgco3= .. number of moles of caco3= .. [3] (ii) calculate the volume of hydrochloric acid, 1.0 mol / dm3, needed to react with one tablet.number of moles of caco 3and mgco3in one tablet = .. use your answer to (c)(i) . number of moles of hc lneeded to react with one tablet = .. volume of hydrochloric acid, 1.0 mol / dm3, needed to react with one tablet = .. [2]for examiner\u2019s use",
            "6": "6 0620/03/m/j/033alkenes are unsaturated hydrocarbons. they undergo addition reactions. (a)two of the methods of making alkenes are cracking and the thermal decomposition of chloroalkanes. (i)complete an equation for the cracking of the alkane, decane. c10h22\u2192.  +  .. decane (ii) propene can be made by the thermal decomposition of chloropropane.describe how chloropropane can be made from propane. reagents propane and ..conditions ... [4] (b)the following alkenes are isomers. ch 3\u2013ch2\u2013ch=ch2ch3\u2013c=ch2| ch3 (i)explain why they are isomers. .. (ii) give the name and structural formula of another hydrocarbon that is isomeric with the above. name ..structural formula [4]for examiner\u2019s use",
            "7": "7 0620/03/m/j/03 [turn over(c)give the name of the product when but-1-ene reacts with each of the following. steam .hydrogen bromine .. [3] (d)alkenes can polymerise. (i)deduce the name and structural formula of the monomer from the structure of the polymer. hh /h20841/h20841 \u2014\u2014\u2014\u2014c\u2014\u2014\u2014\u2014c\u2014\u2014\u2014\u2014 /h20841/h20841 /h20898ch3h/h20899n name of monomer ... structural formula (ii) draw the structure of the polymer formed from the following monomer. o /h20648 ho /h5007c/h5007ch3 cc hh [4]for examiner\u2019s use",
            "8": "8 0620/03/m/j/03(iii) describe the pollution problems caused by the disposal of polymers in landfill sites and by burning. landfill sites ... ...[2] burning .. ...[1] 4nitrogen dioxide, no2, is a dark brown gas. (a)most metal nitrates decompose when heated to form the metal oxide, nitrogen dioxide and oxygen. (i)write a symbol equation for the decomposition of lead( ii) nitrate. pb(no3)2\u2192...  +  ...  +   [2] (ii) potassium nitrate does not form nitrogen dioxide on heating. write the wordequation for its decomposition. ...[1] (b)when nitrogen dioxide is cooled, it forms a yellow liquid and then pale yellow crystals.these crystals are heated and the temperature is measured every minute. thefollowing graph can be drawn. (i)describe the arrangement and movement of the molecules in the region a\u2013b. ... ...temperature timepale yellow crystalsyellow liquid ab cdfor examiner\u2019s use",
            "9": "9 0620/03/m/j/03 [turn over(ii) name the change that occurs in the region b\u2013c ...[4] (c)nitrogen dioxide and other oxides of nitrogen are formed in car engines. (i)explain how these oxides are formed. ... ... (ii) how are they removed from the exhaust gases? ..[4] (d)nitrogen dioxide, oxygen and water react to form dilute nitric acid. describe how lead( ii) nitrate crystals could be prepared from dilute nitric acid and lead( ii) oxide. ..[3]for examiner\u2019s use",
            "10": "10 0620/03/m/j/035the first three elements in period 6 of the periodic table of the elements are caesium, barium and lanthanum. (a)how many more protons, electrons and neutrons are there in one atom of lanthanum than in one atom of caesium. use your copy of the periodic table of the elements tohelp you. number of protons  number of electrons number of neutrons  [3] (b)all three metals can be obtained by the electrolysis of a molten halide. the electrolysis of the aqueous halides does not produce the metal. (i)complete the equation for the reduction of lanthanum ions at the negativeelectrode (cathode). la 3++    \u2192 (ii) name the three products formed by the electrolysis of aqueous caesium bromide. ... ...[4] (c)all three metals react with cold water.  complete the word equation for these reactions. metal   +   water   \u2192.   +   . [2] (d)barium chloride is an ionic compound. draw a diagram that shows the formula of the compound, the charges on the ions and gives the arrangement of the valency electronsaround the negative ion. the electron distribution of a barium atom is 2.8.18.18.8.2 use x to represent an electron from a barium atom. use o to represent an electron from a chlorine atom. [2]for examiner\u2019s use",
            "11": "11 0620/03/m/j/03(e)describe, by means of a simple diagram, the lattice structure of an ionic compound, such as caesium chloride. [2] (f)the reactions of these metals with oxygen are exothermic. 2ba(s)   +   o2(g)\u21922bao(s) (i)give an example of bond forming in this reaction. ... (ii) explain using the idea of bond breaking and forming why this reaction is exothermic. ... ...[3]for examiner\u2019s use",
            "12": "12 0620/03/m/j/03groupdata sheet the periodic table of the elements 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89               \u20209 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series \u202090-103 actinoid series"
        },
        "0620_s03_qp_5.pdf": {
            "1": "this document consists of 6printed pages and 2blank pages. sp (cw) s33051/2 \u00a9 cie 2003 [turn overcambridge international examinations international general certificate of secondary education chemistry 0620/05 paper 5  practical test may/june 2003 1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in instructions to supervisors read these instructions first write your name, centre number and candidate number in the spaces at the top of this page. write in dark blue or black pen in the spaces provided on the question paper.y ou may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction fluid. answer all questions. the number of marks is given in brackets [  ] at the end of each question or part question. practical notes are provided on page 8.centre number candidate number name if you have been given a label, look at the details. if any details are incorrect ormissing, please fill in your correct detailsin the space given at the top of this page. stick your personal label here, if provided.for examiner\u2019s use 1 2 total",
            "2": "2 0620/05/m/j/031y ou are going to investigate the redox reaction between potassium iodate( v) and iodide ions. read allthe instructions below carefully before starting the two experiments. instructionsexperiment 1 fill the burette provided up to the 0.0 cm 3mark with the solution aof sodium thiosulphate. by using a measuring cylinder, pour 10 cm3of the solution bof potassium iodate into the conical flask provided.add 10 cm 3of dilute sulphuric acid to the flask followed by about 20 cm3of the aqueous potassium iodide and shake to mix thoroughly.add solution aslowly to the flask until there is a pale yellow colour in the contents of the flask. now add about 2 cm 3of starch solution into the flask. continue to add solution ato the flask until the colour just disappears. record the burette readings in the table. experiment 2 pour away the contents of the flask and rinse with distilled water. fill the burette up again to the 0.0 cm3mark with the solution aof sodium thiosulphate. repeat experiment 1 using solution cof potassium iodate instead of solution b. record your burette readings in the table and complete the table.table of results [6] (a)describe the appearance of the mixture in the conical flask before solution awas added. ..[1] (b)how did the colour of the solution in the flask change when 2.0 cm 3of starch was added? from ... to .[2]for examiner\u2019s use burette readings/cm3 experiment 1 experiment 2 final reading initial reading difference",
            "3": "3 0620/05/m/j/03the reaction of the mixture of potassium iodate( v), sulphuric acid and potassium iodide in the flask produces iodine. sodium thiosulphate then reacts with the iodine. (c) (i) in which experiment was the greatest volume of aqueous sodium thiosulphate used? ...[1] (ii) compare the volumes of sodium thiosulphate used in experiments 1 and 2. ... ...[2] (iii) suggest an explanation for the difference in the volumes. ..[1] (iv) predict the volume of solution awhich would be needed to react completely if experiment 1 was repeated with 20.0 cm 3of the solution of potassium iodate. explain your prediction.volume of solution a. explanation ... ...[3] (d)what is the purpose of the starch? ..[2] [turn overfor examiner\u2019s use",
            "4": "4 0620/05/m/j/032y ou are provided with a mixture of two solid compounds, dande.dis soluble in water and eis insoluble. carry out the following tests on dande, recording allof your observations in the table. do notwrite any conclusions in the table.for examiner\u2019s use tests observations (a)by using a spatula place about half  of the mixture of dandein a  test-tube. heat the mixture gently then strongly. . .[2] (b)add the rest of the mixture of dande to 10 cm3of distilled water in a boiling  tube. stopper the tube and shake for 1 minute. filter the mixture. keep the filtrate and the residue. filtrate .. residue [2] tests on residue (c) (i) by using a spatula transfer the residue from the filter paper in to a test-tube. carefully add about 3 cm 3of dilute sulphuric . acid. test the gas with limewater.  . .[3] (ii) pour about half of the liquid from  the reaction in (c)(i) into a clean  test-tube. by using a teat pipette .add drops of aqueous ammonia until a change occurs on shaking. .[2] add excess aqueous ammonia . to fill the test-tube. shake the mixture. .[2]",
            "5": "5 0620/05/m/j/03(e)what conclusions can you draw about the identity of solid d? .. ..[2] (f)what conclusions can you draw about the identity of solid e? [2]for examiner\u2019s use tests observations tests on the filtrate (d)divide the filtrate from (b)into three  approximately equal portions. (i)to the first portion add drops of . aqueous sodium hydroxide, a little at a time, with shaking. .[2] add excess aqueous sodium hydroxide. .[1] (ii) to the second portion add .excess aqueous ammonia, a little at a time. . .[3] (iii) to the third portion add a few drops of dilute hydrochloric acidand aqueous barium chloride. .[1]",
            "6": "6 0620/05/m/j/03blank page",
            "7": "7 0620/05/m/j/03blank page",
            "8": "8 0620/05/m/j/03notes for use in qualitative analysis tests for anions tests for aqueous cations tests for gases gas test and test results turns damp red litmus paper blue turns limewater milky bleaches damp litmus paper \u201cpops\u201d with a lighted splint relights a glowing splint oxygen (o2)hydrogen (h2)carbon dioxide (co2)ammonia (nh3) chlorine (c l2)cation aluminium (a l3+) white ppt., soluble in excess giving a colourless solution ammonia produced on warming white ppt., insoluble in excess green ppt., insoluble in excess red-brown ppt., insoluble in excess white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excessgiving a colourless solutionred-brown ppt., insoluble in excesswhite ppt., insoluble in excess \u2013 green ppt., insoluble in excessno ppt., or very slight white ppt. light blue ppt., soluble in excess giving a dark blue solutionlight blue ppt., insoluble in excess iron( ii) (fe2+) iron( iii) (fe3+) zinc (zn2+)ammonium (nh4+) calcium (ca2+) copper (cu2+)effect of aqueous sodium hydroxide effect of aqueous ammoniaanion carbonate (co32\u2013) add dilute acid acidify with dilute nitric acid, then add aqueous silver nitrate acidify with dilute nitric acid, thenaqueous lead( ii) nitrate acidify with dilute nitric acid, thenaqueous barium nitrateeffervescence, carbon dioxideproduced white ppt. white ppt.yellow ppt. ammonia produced add aqueous sodium hydroxide then aluminium foil; warm carefully sulphate (so 42\u2013) [in solution]chloride (c l\u2013) [in solution] iodide ( i\u2013) [in solution] nitrate (no3\u2013) [in solution]test test result"
        },
        "0620_s03_qp_6.pdf": {
            "1": "this document consists of 12printed pages. sp (sm) s33031/3 \u00a9 cie 2003 [turn overcambridge international examinations  international general certificate of secondary education chemistry 0620/06 paper 6  alternative to practical may/june 2003 1 hour candidates answer on the question paper. no additional materials required. read these instructions first write your name, centre number and candidate number at the top of this page. write in dark blue or black pen in the spaces provided on the question paper.y ou may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction fluid. answer all questions. the number of marks is given in brackets [  ] at the end of each question or part question.centre number candidate number name if you have been given a label, look at the details. if any details are incorrect ormissing, please fill in your correct detailsin the space given at the top of this page. stick your personal label here, if provided.for examiner\u2019s use 1 23456 total",
            "2": "2 0620/06/m/j/031look at the diagrams of common laboratory apparatus. a b c dfor examiner\u2019s use",
            "3": "3 0620/06/m/j/03(a)complete the empty boxes to identify the pieces of apparatus labelled. [4] (b)what name is given to the separation method in c? ..[1] (c)which apparatus would be most suitable to obtain crystals from an aqueous solution of copper( ii) sulphate? ..[1] 2a student carried out an experiment to investigate the speed of the reaction between sodiumthiosulphate and dilute hydrochloric acid. na 2s2o3+ 2hcl\uf8e7\u2192 2nacl + s + h2o + so2 experiment 1 by using a measuring cylinder, 50 cm3of sodium thiosulphate solution was poured into a 100 cm3beaker. the beaker was placed on a cross drawn on a piece of paper. 10 cm3of hydrochloric acid was added to the beaker and the timer started. the time was taken until the cross could not be seen. the time was recorded in the table.beakereye aqueous sodium thiosulphate paper with cross marked on it10 cm3 of hydrochloric acid [turn overfor examiner\u2019s use",
            "4": "4 0620/06/m/j/03experiments 2, 3, 4 and 5 experiment 1 was repeated using different volumes of sodium thiosulphate as shown in the table. all experiments were carried out at 25 \u00b0c. table of results (a)why does the cross on the paper disappear? .. ..[2] (b)why was the total volume of solution kept constant? [1] (c)in which order should the water, hydrochloric acid and sodium thiosulphate solution be added to the beaker? first . .. second  .. last .. ..[1]for examiner\u2019s use volume of sodium volume of time for cross toexperimentthiosulphate/cm3 water/cm3 disappear/s 15 004 5 2 4 01 06 0 3 3 02 08 0 4 20 30 130 5 10 40 255",
            "5": "5 0620/06/m/j/03(d) (i) plot the results on the grid below. draw a smooth line graph and label it 25 \u00b0c. [5] (ii) sketch on the grid the graph you would expect if the experiments were repeated at 50 \u00b0c. label this graph. [2]01020304050 50 100 150 200 250 300volume of sodium thiosulphate / cm3 time / s [turn overfor examiner\u2019s use",
            "6": "6 0620/06/m/j/03(e)the experiments were repeated using a 250 cm3beaker instead of a 100 cm3beaker. suggest how the results would differ. explain your answer. .. ..[2] 3a student investigated the redox reaction between potassium iodate( v) and iodide ions. two experiments were carried out. experiment 1 a burette was filled up to the 0.0 cm3mark with the solution aof sodium thiosulphate. by using a measuring cylinder, a 10 cm3sample of the solution bof potassium iodate( v) was added into a conical flask. a 10 cm3sample of dilute sulphuric acid was added to the flask followed by 20 cm3of aqueous potassium iodide. solution awas added slowly to the flask until there was a pale yellow colour in the contents of the flask. starch solution was then added into the flask and the colour changed to blue- black. solution awas added to the flask until the colour just disappeared. use the burette diagram to record the volume in the table. experiment 2 experiment 1 was repeated using solution cof potassium iodate( v) instead of solution b. use the burette diagrams to record the volumes in the table and complete the table. initial burette reading / cm3 1718 16final burette reading / cm3 2526 24final burette reading / cm3 1718 16for examiner\u2019s use",
            "7": "7 0620/06/m/j/03table of results [4] the reaction of the mixture of potassium iodate( v), sulphuric acid and potassium iodide in the flask produces iodine. sodium thiosulphate then reacts with the iodine. (a) (i) in which experiment was the greatest volume of aqueous sodium thiosulphate used? ...[1] (ii) compare the volumes of sodium thiosulphate used in experiments 1 and 2. ... ...[1] (iii) suggest an explanation for the difference in the volumes. ..[2] (iv) predict the volume of solution awhich would be needed to react completely if experiment 1 was repeated with 20.0 cm 3of the solution of potassium iodate. explain your prediction.volume of solution a. explanation ... ...[3] (b)suggest the reason starch solution was added. ..[2] [turn overfor examiner\u2019s use burette readings/cm3 experiment 1 experiment 2 final reading initial reading 0.0 difference",
            "8": "8 0620/06/m/j/034a mixture of two solid compounds dandewas analysed. solid dwas a zinc salt which is soluble in water. solid ewas an insoluble metal carbonate. the tests on the mixture and some of the observations are in the following table. complete the observations in the table.for examiner\u2019s use tests observations (a)about half of the mixture of dande was placed in a test-tube. the  mixture was heated green to black condensation formed (b)the rest of the mixture of dande was added to distilled water in a boiling tube. the contents of the tube were filtered. the filtrate and the residue were kept for the  following tests. test on residue (c)the residue was transferred from thefilter paper in to a test-tube. about 3c m 3of dilute sulphuric acid was  added. the gas was tested with limewater.   [2] the solution obtained in (c)was divided  into two equal portions. (d) (i) to the first portion was added excess aqueous sodiumhydroxide, a little at a time. pale blue precipitate (ii) to the second portion wasadded excess aqueousammonia, a little at a time.   [4]",
            "9": "9 0620/06/m/j/03(f)what conclusions can you draw about the identity of solid d? .. ..[2] (g)what conclusions can you draw about the identity of the cation in solid e? [2] [turn overfor examiner\u2019s use tests observations test on filtrate (e)the filtrate from (b)was divided into three approximately equal  portions. (i)to the first portion were addeddrops of aqueous sodiumhydroxide, a little at a time withshaking.  [2] excess aqueous sodiumhydroxide was added. [1] (ii) to the second portion wasadded excess aqueous  ammonia a little at a time.  [3] (iii) to the third portion were added drops of dilute hydrochloric acidand aqueous barium chloride. white precipitate",
            "10": "10 0620/06/m/j/035an experiment was carried out using the apparatus below. by using a measuring cylinder, 20 cm3of hydrogen peroxide was placed in the flask and 0.8 g of the catalyst, manganese( iv) oxide was added. the bung was replaced and the gas collected was measured at 1 minute intervals. the results were plotted on the grid (opposite). (a) (i) draw a smooth line graph on the grid. [1] (ii) which result appears to be inaccurate? why have you chosen this result? ... ...[2] (b)what mass of manganese( iv) oxide would remain at the end of the experiment? ..[1] (c)what would be the effect of using a rubber connector with a hole in it? [2]20 40 60 80 100cm3 reaction mixturerubber connectorfor examiner\u2019s use",
            "11": "11 0620/06/m/j/03 [turn overvolume of  g a s/c m3 time / minutes020406080100120140160 12345678",
            "12": "12 0620/06/m/j/036beach sand is a mixture of sand and broken shells (calcium carbonate). calcium carbonate reacts with dilute hydrochloric acid to form a solution of calcium chloride. plan an investigation to find out the percentage of shell material in a given sample of beach sand. .. ..[6]for examiner\u2019s use"
        },
        "0620_w03_qp_1.pdf": {
            "1": "this document consists of 19printed pages and 1blank page. spa (nh/pw) s42589/3 \u00a9 ucles 2003 [turn overcambridge international examinations international general certificate of secondary education chemistry 0620/01 paper 1 multiple choice october/november 2003 45 minutes additional materials: multiple choice answer sheet soft clean eraser soft pencil (type b or hb is recommended) read these instructions first write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid.write your name, centre number and candidate number on the answer sheet in the spaces providedunless this has been done for you. there are forty questions on this paper. answer allquestions. for each question there are four possible answers a,b,c, and d. choose the oneyou consider correct and record your choice in soft pencil on the separate answer sheet. read the instructions on the answer sheet very carefully.each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet.a copy of the periodic table is printed on page 20.",
            "2": "2 0620/01 o/n/031a shirt is stained with red ink from a pen. the shirt is left to soak in a bowl of water. which process causes the red colour to spread? adiffusion bevaporation cmelting dneutralisation 2a sealed conical flask contains a liquid and its vapour, as shown. what happens when a molecule in the vapour enters the liquid?vapour liquidwater shirtred ink stain a few hours laterred coloured water a bcdthe molecule stops movingthe molecule becomes smaller \u2713\u2713 \u2717\u2717\u2713 \u2717 \u2713 \u2717",
            "3": "3 0620/01 o/n/03 [turn over3which mixture can be separated by adding water, stirring and filtering? abarium chloride and sodium chloride bcalcium carbonate and sodium chloride ccopper and magnesium dethane and ethene 4a student investigates the speed of the reaction between a lump of zinc and an acid at room temperature. which other item of apparatus does the student need for this experiment? abunsen burner bmeasuring cylinder cstop clock dthermometer 5the table shows the electronic structures of four elements.which element is a noble gas?cotton wool acidzinc balance a bcdnumber of electrons shell 1element shell 2 12220026",
            "4": "4 0620/01 o/n/036the diagrams show four particles. which two diagrams show atoms that are isotopes of each other? a1 and 2 b1 and 3 c2 and 3 d2 and 4 7which of the following can be used as a lubricant?e e ee e ee e ee e e2p 2n3p3n3p3n3p4n 1234 e e= electron = nucleus a bcdgraphite a liquid fraction from petroleum \u2713\u2713 \u2717\u2717\u2713 \u2717 \u2713 \u2717",
            "5": "5 0620/01 o/n/03 [turn over8which element is a solid non-metal? 9the diagrams show the bonding in three covalent molecules. which of these molecules combine to form ammonia? a1 and 2 b1 and 3 c2 and 3 d1, 2 and 3 10two gases react as shown. x2+ y2\u2192 2xy reactants product when measured at the same temperature and pressure, what is the value of ? a1 2 b1 c2 d4volume of product volume of reactants123a bcdmelting point /\u00b0 celement boiling point /\u00b0 celectrical conductance \u2013210 \u20137 119 1539\u2013183 58 445 2887nonono yes",
            "6": "6 0620/01 o/n/0311carbon and chlorine form a chloride. what is the formula of this chloride?accl 2 bccl4 ccacl2 dcacl4 12the following electrolysis circuit is set up, using inert electrodes.at which electrode is a metal deposited? 13the diagram shows a method used to electroplate a key with copper. which aqueous solution is most suitable for the electrolyte? acopper( ii) sulphate bethanol csodium hydroxide dsulphuric acid+\u2013 copper foil key electrolyteab cd+\u2013 +\u2013 concentrated aqueoussodium chloridemoltenlead(ii ) bromide",
            "7": "7 0620/01 o/n/03 [turn over14the graph shows how the total volume of a gas given off from a reaction changes with time. in which time interval is least gas given off? 15potassium nitrate is a salt and dissolves in water in an endothermic process.what happens to the temperature and ph of the water as the salt dissolves?ab c d timevolume of gas a bcdtemperature increasesph falls \u2713\u2713 \u2717\u2717\u2713 \u2717 \u2713 \u2717",
            "8": "8 0620/01 o/n/0316lead( ii) oxide is reduced in the apparatus shown. how do the masses of parts xandyof the apparatus change? 17the equation shows what happens when hydrated copper( ii) sulphate is heated. cuso4.5h2o(s) cuso4( s )+5 h2o(g) what can be deduced from the equation? athe hydrated copper( ii) sulphate is oxidised. bthe hydrated copper( ii) sulphate is reduced. cthe reaction is reversible. dthere is no colour change.hydrogen heatexcess of hydrogenparty partx drying agentlead(ii ) oxide a bcdxy decreasesdecreases increasesincreasesdecreases increases decreases increases",
            "9": "9 0620/01 o/n/03 [turn over18the diagram shows an experiment. which metal would fill the syringe with 100 cm3of gas in the shortest time? a5 g of copper b5 g of iron c5 g of magnesium d5 g of zinc 19which two processes are involved in the preparation of magnesium sulphate crystals from dilute sulphuric acid and an excess of magnesium oxide? adecomposition and filtration bdecomposition and oxidation cneutralisation and filtration dneutralisation and oxidationexcess of hydrochloric acid20 40 60 80 100cm3 gas syringe metal",
            "10": "10 0620/01 o/n/0320the diagram shows the result of testing an aqueous solution z. which ion is present in solution z? acarbonate bchloride cnitrate dsulphate 21the ph values of four solutions are shown. mixing combinations of these solutions can give a solution of ph 6. which combination of solutions could notdo this? ap and r bp and s cq and r dr and s1 23456789 1 0 1 1 1 2 1 3 1 4 pq rsgentle heatsolution z + aqueus sodium hydroxidedamp litmus paper goes blue aluminium powder",
            "11": "11 0620/01 o/n/03 [turn over22eight elements are numbered in the diagram of a periodic table. which numbers represent two relatively soft metals in the same group? a1 and 2 b3 and 4 c5 and 6 d7 and 8 23vanadium is a transition metal.what are its likely properties? 24the table gives information about four elements.which element could be in group i in the periodic table?a bcddensity appearance of compounds 0.61 g / cm 3 0.61 g / cm3 6.1 g / cm3 6.1 g / cm3coloured white coloured white abcdmetallic or non-metallic element reaction with water metalmetal non-metalnon-metalreacts no reaction reacts no reaction",
            "12": "12 0620/01 o/n/0325element x \u2022forms an alloy. \u2022has a basic oxide. \u2022is below hydrogen in the reactivity series. what could xand the alloy be? 26the diagram shows a method for changing a metal oxide into a metal. which oxide can be changed into a metal by using this method? acalcium oxide bcopper( ii) oxide cmagnesium oxide dpotassium oxide 27the table shows properties of four elements.which element is used to make aircraft bodies?hydrogenmetal oxide excess of hydrogen burning heata bcdx alloy carboncopper iron sulphursteel brass steel brass abcddensity g/cm 3element brittle or malleable 2.12.74.97.9brittle malleable brittle malleable",
            "13": "13 0620/01 o/n/03 [turn over28three metals x,y, and zare correctly placed in the reactivity series as shown. most reactive potassium x sodiumzincyironcopper least reactive z how are x,yandzobtained from their ores? 29the diagram shows how water is purified. at which stage are bacteria in the water killed? 30which two fuels each produce both carbon dioxide and water when separately burned in air?acharcoal and hydrogen bcharcoal and petrol cnatural gas and hydrogen dnatural gas and petrolscreen water in pump pumpcoarse filter sediment tankfine filterchlorine addedcovered storage tank to homes andfactoriesa bc da bcdelectrolysis reduction with carbon found uncombined xxy zy z xxz y z y",
            "14": "14 0620/01 o/n/0331which compound in polluted air can damage stonework and kill trees? acarbon dioxide bcarbon monoxide clead compounds dsulphur dioxide 32the apparatus shown is set up and left for a week. where would the water level be at the end of the week? 33an npk fertiliser contains three elements required for plant growth. which two compounds, when mixed, provide the three elements?aammonium phosphate + potassium nitrate bammonium sulphate + potassium nitrate cammonium sulphate + sodium nitrate dsodium phosphate + potassium chlorideoriginal levelabcdwaterairdamp iron wool",
            "15": "15 0620/01 o/n/03 [turn over34two processes are listed. 1 treating acidic soil with slaked lime 2 using limestone to extract iron in which of these processes is carbon dioxide produced? 35organic compounds may have names ending in \u2013ane, -ene, -ol or \u2013oic acid.how many of these endings indicate the compounds contain double bonds in their molecules?a1 b2 c3 d4 36which compound is unsaturated and forms a neutral solution in water? 37which fraction produced by the distillation of petroleum is used as aircraft fuel?abitumen bdiesel cparaffin dpetrolch 2oh ch ch ch 2ohch 2oh ch 2 ch 2 ch 2ohco 2h ch ch co 2hco 2h ch 2 ch 2 co 2hab c da bcd12 \u2713\u2713 \u2717\u2717\u2713 \u2717 \u2713 \u2717",
            "16": "16 0620/01 o/n/0338the diagram shows the structures of two compounds. the two compounds have similar chemical properties. why is this?their molecules have the sameafunctional group. bnumber of carbon atoms. cnumber of oxygen atoms. drelative molecular mass.h c o c chhh hhhh h c c chhh hohh h",
            "17": "17 0620/01 o/n/03 [turn over39the apparatus shows an experiment used to test gas x. the bromine solution quickly becomes colourless. what is the structure of gas x? h c hh h h c c hhh hh h c c ohhhh hh c ch h ha b c dorange bromine solutiongasx",
            "18": "18 0620/01 o/n/0340the diagram shows the manufacture of an important organic chemical x. what is x? aethane bethanol cmethane dmethanolsteamethene x catalyst",
            "19": "19 0620/01 o/n/03blank page",
            "20": "20 0620/01 o/n/03groupdata sheet the periodic table of the elements 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89               \u20209 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series \u202090-103 actinoid series"
        },
        "0620_w03_qp_2.pdf": {
            "1": "this document consists of 17printed pages and 3blank pages. sp (at/kn) s33035/2 \u00a9 cie 2003 [turn overcambridge international examinations  international general certificate of secondary education chemistry 0620/02 paper 2 october/november 2003 1 hour candidates answer on the question paper. no additional materials required read these instructions first write your name, centre number and candidate number in the spaces at the top of this page. write in dark blue or black pen in the spaces provided on the question paper.you may use a pencil for any diagrams, graphs, or rough working.do not use staples, paper clips, highlighters, glue or correction fluid. answer allquestions. the number of marks is given in brackets [  ] at the end of each question or part question. a copy of the periodic table is provided on page 20.centre number candidate number name if you have been given a label, look at the details. if any details are incorrect ormissing, please fill in your correct detailsin the space given at the top of this page. stick your personal label here, if provided.for examiner\u2019s use 1 2345 6 total",
            "2": "2 0620/2/o/n/031the diagrams show four methods of purifying substances. (a)which of these methods, a,b,c ord, is best used for (i)separating the different colours in a sample of ink? (ii) separating two liquids with different boiling points? (iii) separating mud from water? (iv) making crystals of copper sulphate from copper sulphate solution? [4]heatethanol vapour filter paper ethanol a cdbfor examiner\u2019s use",
            "3": "3 0620/2/o/n/03 [turn over(b)state the name given to the method of separation shown in (i)diagram a, . (ii) diagram b. . [2] (c)method a can be modified to separate petroleum into useful fractions. the diagram below shows the different fractions obtained from a fractionating column. (i)which of these fractions has the lowest boiling point? ... (ii) state oneuse for each of the following fractions. paraffin .. bitumen . [3] (d)petroleum is a mixture of organic compounds.  which oneof the following best describes the compounds found in petroleum? put a ring around the correct answer. acids alcohols carbohydrates hydrocarbons [1]fractions fuel gas petrol paraffin light gas oil diesel lubricating fraction bitumencrude oilfor examiner\u2019s use",
            "4": "4 0620/2/o/n/03(e)before petroleum is fractionated, it is often heated to remove dissolved natural gas.  most of this natural gas is methane, ch4. draw a diagram to show how the electrons are arranged in methane. show hydrogen electrons as \u2022 show carbon electrons as /h11003 [2] (f)methane, ethane and propane belong to a particular homologous series of compounds. state the name of the homologous series to which these three compounds belong. .. [1]for examiner\u2019s use",
            "5": "5 0620/2/o/n/03 [turn over2the diagram below shows a modern landfill site for the disposal of waste materials. the waste materials are broken down naturally in several stages. (a)in the first stage, micro-organisms (mainly bacteria) break down some of the organic material in the waste to carbon dioxide.what is the name given to the process by which organisms use food to produce carbondioxide? ..[1] (b)in the second stage, the micro-organisms break down organic substances to produceammonia, hydrogen and more carbon dioxide. (i)describe a test for hydrogen.  test .. .. result  . (ii) the large volumes of hydrogen produced may be hazardous. explain why hydrogen may be hazardous when mixed with air. ... (iii) ammonia is a base.describe a test for ammonia. test .. .. result  . [5]waste gases soil cover solid waste clay lining plastic lining liquid material collected for furthertreatmentliquid materialdraining throughgroundfor examiner\u2019s use",
            "6": "6 0620/2/o/n/03(c)in the third stage, ethanoic acid is produced.  draw the structure of ethanoic acid showing all atoms and bonds. [1] (d)in the fourth stage, carbon dioxide reacts with hydrogen to form methane and oxygen. (i)complete the equation for this reaction. co2+ \u2026\u2026.. \u2192ch4+ o2 (ii) state one use of methane. ... (iii) methane is a gas. which twoof the following statements about gas molecules are true? tick two boxes. the molecules are far apart. the molecules are not moving.the molecules are randomly arranged.the molecules are arranged in a regular manner. [4]for examiner\u2019s use",
            "7": "7 0620/2/o/n/03 [turn over(e)the list below shows some of the substances which are found in the liquid which drains through the waste.  aluminium calcium carbonate iron lead magnesium nickel sodium sulphate zinc from this list choose  (i)a metal used to galvanise iron. . (ii) a transition metal. . (iii) a metal which is in group iv of the periodic table.  (iv) a substance which will release carbon dioxide when an acid is added. ... (v) a metal which is used to make aircraft bodies. . [5]for examiner\u2019s use",
            "8": "8 0620/2/o/n/033one way of making lime from limestone (calcium carbonate) is shown in the diagram. the limestone is mixed with coke and dropped into the limekiln. the coke is burnt and releases heat. (a)state oneuse of limestone, other than in making lime. ..[1] (b)coke is mainly carbon. write a symbol equation for the burning of carbon. [2] (c)state the name of the type of reaction which releases heat energy. ..[1] (d)the heat produced by the burning coke causes thermal decomposition of the limestone.complete the word equation for the thermal decomposition of calcium carbonate. calcium carbonate \u2192.  + .  [2]gases out firebrick walllimestone and coke lime and ash outfor examiner\u2019s use",
            "9": "9 0620/2/o/n/03(e) (i) complete the following equation for the reaction of calcium carbonate with hydrochloric acid. caco3+ \u2026 hcl \u2192cacl2+ co2+ h2o (ii) describe how you would test for the gas given off in this reaction. test .. .. result  . [3] (f)quicklime, cao, is a product of the thermal decomposition of calcium carbonate.when quicklime is heated strongly with coke, calcium carbide is formed. cao + 3c \u2192cac 2+ co (i)what type of reaction is the conversion of c to co? explain your answer. ... ... (ii) when water is added to calcium carbide, cac2, acetylene is formed. state a use of acetylene. ... [3]for examiner\u2019s use",
            "10": "10 0620/2/o/n/034bromine is an element in group vii of the periodic table.  (a)state the name given to the group vii elements. ..[1] (b)bromine has two isotopes. the nucleon (mass) number of bromine-79 is 79 and of bromine-81 is 81. (i)what is the meaning of the term isotopes ? ... ... (ii) complete the table to show the numbers of electrons, neutrons and protons in one atom of bromine-79 and bromine-81. a copy of the periodic table is printed onpage 20. [5] (c)bromine is extracted from seawater by treatment with chlorine. when chlorine is bubbled through a solution of potassium bromide, the solution turnsorange-red.  (i)what does this tell you about the reactivity of chlorine compared with bromine? ... (ii) write a word equation for this reaction. [2]for examiner\u2019s use number of bromine-79 bromine-81 electrons neutrons protons",
            "11": "11 0620/2/o/n/03 [turn over(d)in order to get the maximum yield of bromine from seawater, acid is added during the extraction procedure. the graph shows how the yield of bromine changes with ph. (i)what is the highest ph at which the yield of bromine is 100%? ... (ii) the ph scale is used to measure acidity.some ph values are given below. ph 3 ph 5 ph 7 ph 9 ph 11 from this list of ph values choosethe ph which is most acidic. .the ph of a neutral solution. .. [3] (e)bromine water can be used to distinguish between ethane and ethene. describe what you would observe when bromine water is added to ethene.  .. [1]0 1 2 3 4 5 6 7 820406080100 yield of bromine % phfor examiner\u2019s use hh h\u2013\u2013c\u2013\u2013c\u2013\u2013h hh\u2013\u2013 \u2013\u2013\u2013\u2013 \u2013\u2013hh cchh\u2013\u2013 \u2013\u2013\u2013\u2013 \u2013\u2013\u2013\u2013\u2013\u2013 ethane ethene",
            "12": "12 0620/2/o/n/035when fuels are burnt, carbon dioxide and water are formed. (a)complete the equation for the burning of propane. c3h8+ \u2026 o2\u21923co2+ 4h2o [1] (b)describe a chemical test for water.test .. . result   [2] (c)in which twoof the following is carbon dioxide produced. tick two boxes. a car driven by a petrol engine magnesium carbonate reacting with an acidsodium reacting with waterzinc reacting with hydrochloric acid [2]for examiner\u2019s use",
            "13": "13 0620/2/o/n/03 [turn over(d)the diagram shows a water heater. if some of the air holes become blocked, a poisonous gas is produced. (i)state the name of this poisonous gas. ... (ii) explain how this poisonous gas has been formed.  ... ... [2]air holeshot water out cold water incombustion products gas burning in airfor examiner\u2019s use",
            "14": "14 0620/2/o/n/03(e)the table below compares the amounts of carbon dioxide and sulphur dioxide formed when 1 kilogram of different fuels are burnt. (i)which fuel is least polluting? ... (ii) which fuel when burnt, contributes most to the formation of acid rain? ... (iii) state two harmful effects of acid rain. ... ... (iv) when acid rain falls on the ground, it can react with insoluble aluminium compounds in the soil. a solution of aluminium ions is formed.  describe what you would observe when aqueous sodium hydroxide is added to a solution containing aluminium ions.  ... ... [6]for examiner\u2019s use fuelmass of carbon mass of sulphur dioxide produced / g dioxide produced / g oil 2900 5.0 gas 2500 0.1 coal 2500 11.0",
            "15": "15 0620/2/o/n/03 [turn over6aluminium is extracted from its ore, bauxite. the bauxite is purified to give aluminium oxide.electrolysis is then used to extract the aluminium from aluminium oxide dissolved in cryolite. the melting point of pure aluminium oxide is 2070 \u00b0c. the melting point of the mixture of aluminium oxide and cryolite is about 1000 \u00b0c. (a)suggest why electrolysis is used to extract aluminium from aluminium oxide rather than reduction using carbon. .. ..[1] (b)how is the electrolyte of aluminium oxide and cryolite kept molten? ..[1] (c)what property of graphite makes it suitable for use as electrodes?  ..[1] (d)state the name given to the negative electrode. ..[1] (e)the melting point of steel is about 1500 \u00b0c. suggest two reasons why molten aluminium oxide is not used by itself in this electrolysis. [2] (f)during the electrolysis, hot oxygen is formed at the positive electrodes. suggest why the positive electrodes have to be replaced frequently. .. ..[2]for examiner\u2019s use negative electrode (graphite) steel case\u2013+ aluminium oxide dissolvedin molten cryolitepositive electrode (graphite) molten aluminium collectingon the bottom",
            "16": "16 0620/2/o/n/03(g)aluminium is formed at the negative electrode.  complete the following equation for the reaction at the negative electrode. al3++ \u2026\u2026 \u2192 al [1] (h)why do aluminium ions move towards the negative electrode? ..[1] (i)a sample of bauxite ore had the following composition: aluminium oxide 120giron( iii) oxide 30g silica 40gtitanium( iv) oxide 10g calculate the percentage of aluminium oxide in this sample of bauxite. [1] (j)aluminium is a metal in group iii of the periodic table.state three physical properties which are typical of most metals. 1 . .. 2 . .. 3 . .. [3]for examiner\u2019s use",
            "17": "17 0620/2/o/n/03blank page",
            "18": "18 0620/2/o/n/03blank page",
            "19": "19 0620/2/o/n/03blank page",
            "20": "20 0620/2/o/n/03for examiner\u2019s usegroupdata sheet the periodic table of the elements 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89               \u20209 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series \u202090-103 actinoid series"
        },
        "0620_w03_qp_3.pdf": {
            "1": "this document consists of 10printed pages and 2blank pages. sp (sm) s34684/4 \u00a9 cie 2003 [turn overcambridge international examinations  international general certificate of secondary education chemistry 0620/03 paper 3 october/november 2003 1 hour 15 minutes candidates answer on the question paper. no additional materials are required. read these instructions first write your name, centre number and candidate number at the top of this page. write in dark blue or black pen in the spaces provided on the question paper.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction fluid. answer allquestions. the number of marks is given in brackets [  ] at the end of each question or part question. a copy of the periodic table is printed on page 12.centre number candidate number name if you have been given a label, look at the details. if any details are incorrect ormissing, please fill in your correct detailsin the space given at the top of this page. stick your personal label here, if provided.for examiner\u2019s use 1 2345 total",
            "2": "2 0620/03/o/n/031ammonia contains the elements nitrogen and hydrogen. it is manufactured from these elements in the haber process. n2(g)  +  3h2(g)         2nh3(g) the forward reaction is exothermic. (a) (i) nitrogen is obtained from liquid air by fractional distillation. why does this technique separate liquid oxygen and nitrogen? ... ... (ii) name tworaw materials from which hydrogen is manufactured. ...[3] (b)the table shows how the percentage of ammonia in the equilibrium mixture varies with pressure at 600 \u00b0c. (i)explain why the percentage of ammonia increases as the pressure increases. ... ...[2] (ii) how would the percentage of ammonia change if the measurements had been made at a lower temperature?  explain your answer. ... ..[2] (iii) state twoof the reaction conditions used in the haber process. ..[2]for examiner\u2019s use percentage ammonia 8 12 15 20 pressure/atm 200 300 400 500",
            "3": "3 0620/03/o/n/03 [turn over(c)ammonia is a base. (i)name a particle that an ammonia molecule can accept from an acid. ... (ii) write an equation for ammonia acting as a base. ...[3] (d)given aqueous solutions, 0.1mol/dm3, of sodium hydroxide and ammonia, describe how you could show that ammonia is the weaker base. .. ..[2] (e)another compound that contains nitrogen and hydrogen is hydrazine, n2h4. (i)draw the structural formula of hydrazine. hydrogen can form only one bond per atom but nitrogen can form three. (ii) draw a diagram that shows the arrangement of the valency electrons in one molecule of hydrazine. hydrazine is a covalent compound.use x to represent an electron from a nitrogen atom.use o to represent an electron from a hydrogen atom. [3]for examiner\u2019s use",
            "4": "4 0620/03/o/n/032some of the factors that can determine the rate of a reaction are concentration, temperature and light intensity. (a)a small piece of calcium carbonate was added to an excess of hydrochloric acid. thetime taken for the carbonate to react completely was measured. caco 3(s)  +  2hc l(aq)\u2192cacl2(aq)  +  co2(g)  +  h2o(l) the experiment was repeated at the same temperature, using pieces of calcium carbonateof the same size but with acid of a different concentration. in all the experiments anexcess of acid was used. (i)complete the table (assume the rate is proportional to both the acid concentrationand the number of pieces of calcium carbonate). [3] (ii) explain why the reaction rate would increase if the temperature was increased. ... ...[2] (iii) explain why the rate of this reaction increases if the piece of carbonate is crushed to a powder. ...[1] (iv) fine powders mixed with air can explode violently. name an industrial processwhere there is a risk of this type of explosion. ... ...[1] (b)sodium chlorate( i) decomposes to form oxygen and sodium chloride. this is an example of a photochemical reaction. the rate of reaction depends on the intensity of the light. 2naclo(aq) \u21922nacl(aq)  +  o2(g) (i)describe how the rate of this reaction could be measured. ..[2]for examiner\u2019s use concentration of acid / mol dm\u201334 2 2 \u2026\u2026\u2026. number of piecesof carbonate 1121 time / s \u2026\u2026\u2026. 80 \u2026\u2026\u2026. 160",
            "5": "5 0620/03/o/n/03 [turn over(ii)how could you show that this reaction is photochemical? ... ...[1] (c)photosynthesis is another example of a photochemical reaction. glucose and more complex carbohydrates are made from carbon dioxide and water. (i)complete the equation. 6co2+  6h2o\u2192c6h12o6+  \u2026\u2026\u2026.. [2] (ii)glucose can be represented as draw the structure of a more complex carbohydrate that can be formed from glucose by condensation polymerisation. [2] 3zinc blende is the common ore of zinc. it is usually found mixed with an ore of lead andtraces of silver.  (a) (i) describe how zinc blende is changed into zinc oxide. ... ...[2] (ii) write an equation for the reduction of zinc oxide by carbon. ...[2] (iii) the boiling point of lead is 1740 \u00b0c and that of zinc is 907 \u00b0c. explain why, when both oxides are reduced by heating with carbon at 1400 \u00b0c, only lead remains inthe furnace. ... ...[2]ho ohfor examiner\u2019s use",
            "6": "6 0620/03/o/n/03(b)a major use of zinc is to make diecasting alloys. these contain about 4% of aluminium and they are stronger and less malleable than pure zinc. (i)give one other large scale use of zinc. ...[1] (ii) describe the structure of a typical metal, such as zinc, and explain why it ismalleable. ... ..[3] (iii) suggest why the introduction of a different metallic atom into the structure makes the alloy stronger than the pure metal. ... ...[2] (c)a solution of an impure zinc ore contained zinc, lead and silver( i) ions. the addition of zinc dust will displace both lead and silver. (i)the ionic equation for the displacement of lead is as follows. change 1 zn(s)   +   pb 2+(aq)\u2192zn2+(aq)   +   pb(s) change 2 which change is reduction? explain your answer. ..[2] (ii) write an ionic equation for the reaction between zinc atoms and silver( i) ions. ...[2]for examiner\u2019s use",
            "7": "7 0620/03/o/n/03 [turn over4esters occur naturally in plants and animals. they are manufactured from petroleum. ethyl ethanoate and butyl ethanoate are industrially important as solvents. (a) (i) explain the term solvent. ...[1] (ii) give the formula of ethyl ethanoate. [1] (iii) ethyl ethanoate can be made from ethanol and ethanoic acid. describe how these chemicals can be made. ethanol from ethene ..[2] ethanoic acid from ethanol ..[2] (iv) name twochemicals from which butyl ethanoate can be made. ...[1] (b)the following equation represents the alkaline hydrolysis of a naturally occurring ester. (i)which substance in the equation is an alcohol? underline the substance in the equation above. [1] (ii) what is the major use for compounds of the type c 17h35coona ? ...[1]c17h35ch2 co2 c17h35ch co2 c17h35+  3naoh         3c17h35coona ch2ch2oh choh ch2oh co2+for examiner\u2019s use",
            "8": "8 0620/03/o/n/03(c)a polymer has the structure shown below. (i)what type of polymer is this? ...[1] (ii) complete the following to give the structures of the two monomers from which the above polymer could be made. [2] (d)esters are frequently used as solvents in chromatography. a natural macromoleculewas hydrolysed to give a mixture of amino acids. these could be identified bychromatography. (i)what type of macromolecule was hydrolysed? ..[1] (ii) what type of linkage was broken by hydrolysis? ..[1] (iii) explain why the chromatogram must be sprayed with a locating agent before theamino acids can be identified. ... ...[1] (iv) explain how it is possible to identify the amino acids from the chromatogram. ..[2]c o oco ofor examiner\u2019s use",
            "9": "9 0620/03/o/n/035sulphur dioxide, so2, and sulphur trioxide, so3, are the two oxides of sulphur. (a)sulphur dioxide can kill bacteria and has bleaching properties. give a use of sulphur dioxide that depends on each of these properties. (i)ability to kill bacteria .[1] (ii) bleaching properties .[1] (b)sulphur trioxide can be made from sulphur dioxide. (i)why is this reaction important industrially? ...[1] (ii) complete the word equation.  sulphur dioxide  +  \u2026\u2026\u2026\u2026\u2026\u2026.\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026   \u2192 sulphur trioxide [1] (iii) what are the conditions for this reaction? ..[2] (c)sulphur dioxide is easily oxidised in the presence of water. so 2+  2h2o  \u2013  2e\u2013\u2192so42\u2013+  4h+ (i)what colour change would be observed when an excess of aqueous sulphur dioxide is added to an acidic solution of potassium manganate( vii)? ...[2] (ii) to aqueous sulphur dioxide, acidified barium chloride solution is added. the mixture remains clear. when bromine is added, a thick white precipitate forms. what is thewhite precipitate? explain why it forms. ... ...[3] (d)sulphur dioxide reacts with chlorine in an addition reaction to form sulphuryl chloride. so 2+  cl2\u2192so2cl2 8.0 g of sulphur dioxide was mixed with 14.2 g of chlorine. the mass of one mole of so2cl2is 135 g. calculate the mass of sulphuryl chloride formed by this mixture. calculate the number of moles of so2in the mixture =  \u2026\u2026\u2026\u2026\u2026\u2026 calculate the number of moles of c l2in the mixture =  \u2026\u2026\u2026\u2026\u2026\u2026 which reagent was not in excess?  \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026.how many moles of so 2cl2were formed  =  \u2026\u2026\u2026\u2026\u2026\u2026. calculate the mass of sulphuryl chloride formed  =  \u2026\u2026\u2026\u2026. g [5]for examiner\u2019s use",
            "10": "10 0620/03/o/n/03blank page",
            "11": "11 0620/03/o/n/03blank page",
            "12": "12 0620/03/o/n/03groupdata sheet the periodic table of the elements 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89               \u20209 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series \u202090-103 actinoid series"
        },
        "0620_w03_qp_5.pdf": {
            "1": "this document consists of 7printed pages, 1blank page and an insert. sp (sm) s34036/5 \u00a9 ucles 2003 [turn overcambridge international examinations  international general certificate of secondary education chemistry 0620/05 paper 5  practical test october/november 2003 1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in instructions to supervisors read these instructions first write your name, centre number and candidate number in the spaces at the top of this page. write in dark blue or black pen in the spaces provided on the question paper.y ou may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction fluid. answer all questions. the number of marks is given in brackets [  ] at the end of each question or part question. practical notes are printed on page 8.centre number candidate number name if you have been given a label, look at the details. if any details are incorrect ormissing, please fill in your correct detailsin the space given at the top of this page. stick your personal label here, if provided.for examiner\u2019s use 1 2 total",
            "2": "2 0620/05/o/n/031y ou are going to investigate the speed of reaction between aqueous potassium bromate and potassium iodide solution. read alltheinstructions below carefully before starting the experiments. instructions fill the burette upto the 0.0 cm3mark with the aqueous potassium iodide. put 5 test-tubes in a rack. using the burette, add 6 cm3of aqueous potassium iodide to each test-tube to be used in the 5 following experiments. experiment 1 y ou are going to measure 5 different solutions into a small beaker. use the 10 cm3 measuring cylinder to measure all the solutions. the cylinder does notneed rinsing between additions.using the measuring cylinder pour 12 cm 3of the aqueous potassium bromate into the small beaker. use the 10 cm3measuring cylinder to add 2 cm3of hydrochloric acid and 4 cm3of water to the beaker. now add 5 cm3of starch solution and 1 cm3of sodium thiosulphate solution to the beaker. place the beaker on the insert. add 6 cm3of aqueous potassium iodide from a test-tube to the mixture in the beaker and start your timer. stop the timer when you can no longer read the words on the insert when looking down through the beaker. record the time in the table. pour away the contents of the beaker and rinse the beaker with distilled water.table of results [4]for examiner\u2019s use experiment volume time/s potassium bromate/cm3 water/cm3 11 2 4 21 0 6 38 8 46 1 0 54 1 2",
            "3": "3 0620/05/o/n/03experiment 2 using a measuring cylinder pour into the beaker 10 cm3of the potassium bromate solution. follow the instructions exactly as given for experiment 1, using the same volumes of the other reagents, but this time add 6 cm3of water to the beaker. record your time in the table. experiments 3, 4 and 5 repeat experiment 1 using the volumes of aqueous potassium bromate and water specified in the table of results. record the times in the table. [turn overfor examiner\u2019s use",
            "4": "4 0620/05/o/n/03(a)plot your results on the grid. draw a smooth line graph. [4] 12 experiment numbertime/s 345for examiner\u2019s use",
            "5": "5 0620/05/o/n/03(b)describe how the appearance of the mixture in the beaker changed as you timed the reaction. ..[2] (c)from your graph estimate the time of the reaction if experiment 1 was repeated using7c m 3of potassium bromate and 9 cm3of water. ..[2] show clearly on your graph how you worked out your answers. [1] (d) (i) which experiment is the quickest? ...[1] (ii) explain why this experiment is the quickest. ... ..[2] (e) (i) state twosources of error in the experiments. 1 . ... ... 2 . ... ...[2] (ii) suggest twoimprovements to reduce the sources of error in the experiments. 1 . ... ... 2 . ... ...[2] [turn overfor examiner\u2019s use",
            "6": "6 0620/05/o/n/032y ou are provided with an aqueous solution of substance x. carry out the following tests on x, record all of your observations in the table. do notwrite any conclusions in the table. (f)what conclusions can you draw about substance x? .. [4]for examiner\u2019s use tests observations (a)colour of solution x. .[1] (b) (i) by using a teat pipette add drops of aqueous sodium hydroxide to . about 2 cm3of the solution in a  test-tube. .now add excess aqueous sodium hydroxide to the test-tube. .[3] (ii) carefully warm the mixture. . test any gas given off with . damp indicator paper. .[2] (c)repeat (b)(i) using aqueous  ammonia instead of aqueous .sodium hydroxide. . .[3] (d)acidify about 2 cm3of solution xwith dilute sulphuric acid. add two pieces .of zinc. warm the mixture gently.test the gas given off. . .[3] leave the mixture to react for .10 minutes. after 10 minutes decant the liquid and repeat test (b)(i) . .[2] (e)add a few drops of hydrochloric acidto about 2 cm 3of solution xin a  test-tube. add about 1 cm3of barium  chloride solution to the mixture. .[2]",
            "7": "7 0620/05/m/j/03blank page",
            "8": "8 0620/05/m/j/03notes for use in qualitative analysis tests for anions tests for aqueous cations tests for gases gas test and test results turns damp red litmus paper blue turns limewater milky bleaches damp litmus paper \u201cpops\u201d with a lighted splint relights a glowing splint oxygen (o2)hydrogen (h2)carbon dioxide (co2)ammonia (nh3) chlorine (c l2)cation aluminium (a l3+) white ppt., soluble in excess giving a colourless solution ammonia produced on warming white ppt., insoluble in excess green ppt., insoluble in excess red-brown ppt., insoluble in excess white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excessgiving a colourless solutionred-brown ppt., insoluble in excesswhite ppt., insoluble in excess \u2013 green ppt., insoluble in excessno ppt., or very slight white ppt. light blue ppt., soluble in excess giving a dark blue solutionlight blue ppt., insoluble in excess iron( ii) (fe2+) iron( iii) (fe3+) zinc (zn2+)ammonium (nh4+) calcium (ca2+) copper (cu2+)effect of aqueous sodium hydroxide effect of aqueous ammoniaanion carbonate (co32\u2013) add dilute acid acidify with dilute nitric acid, then add aqueous silver nitrate acidify with dilute nitric acid, thenaqueous lead( ii) nitrate acidify with dilute nitric acid, thenaqueous barium nitrateeffervescence, carbon dioxideproduced white ppt. white ppt.yellow ppt. ammonia produced add aqueous sodium hydroxide then aluminium foil; warm carefully sulphate (so 42\u2013) [in solution]chloride (c l\u2013) [in solution] iodide ( i\u2013) [in solution] nitrate (no3\u2013) [in solution]test test result"
        },
        "0620_w03_qp_6.pdf": {
            "1": "this document consists of 11printed pages and 1blank page. sp (sc/slc) s33049/4 \u00a9 cie 2003 [turn overcambridge international examinations  international general certificate of secondary education chemistry 0620/06 paper 6  alternative to practical october/november 2003 1 hour 15 minutes candidates answer on the question paper. no additional materials required. read these instructions first write your name, centre number and candidate number in the spaces provided at the top of this page. write in dark blue or black pen in the spaces provided on the question paper.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction fluid. answer allquestions. the number of marks is given in brackets [  ] at the end of each question or part question.centre number candidate number name if you have been given a label, look at the details. if any details are incorrect ormissing, please fill in your correct detailsin the space given at the top of this page. stick your personal label here, if provided.for examiner\u2019s use 1 2 3 4 5 6 total",
            "2": "2 0620/06 o/n/031the apparatus below was used to separate ethanol from water. (a)complete the empty boxes to name the pieces of apparatus. [3] (b)indicate by an arrow where heat is applied. [1] (c)name this separation process. ..[2]for examiner\u2019s use",
            "3": "3 0620/06 o/n/03 [turn over2a student extracted and investigated the orange colour in some sweets. the student followed these instructions: 1collect sweets, a watch glass, a beaker, eye protection and 100 cm3of ethanol. 2crush the sweets. 3place the crushed sweets in the beaker containing 100 cm3of ethanol. 4boil the mixture with the watch glass covering the beaker. 5decant the liquid and concentrate it by evaporation until the colour is dark orange. 6investigate which colours are present in the orange solution. (a)why should the sweets be crushed? [2] (b)why should the experiment be carried out in a well-ventilated laboratory? ..[1] (c)state onesafety precaution that the student should have taken, other than carrying out the experiment in a well-ventilated laboratory and using eye protection. ..[1] (d)state the purpose of the watch glass. ..[1] (e)explain the term decant. ..[1] (f)describe how the student could carry out instruction 6. y ou may draw a diagram in the space below to help you answer the question. .. [5]for examiner\u2019s use",
            "4": "4 0620/06 o/n/033a student investigated the speed of reaction between aqueous potassium bromate and potassium iodide solution. a burette was filled up to the 0.0 cm3mark with aqueous potassium iodide. to each of 5 test-tubes was added 6 cm3of aqueous potassium iodide to be used in the 5 following experiments. experiment 1 by using a measuring cylinder 12 cm3of aqueous potassium bromate was poured into a small beaker. to this solution was added 4 cm3of water, 2 cm3of hydrochloric acid, 5 cm3of starch solution and 1 cm3of sodium thiosulphate solution. the beaker was placed on a cross drawn on a piece of paper. from one of the test-tubes 6 cm3of aqueous potassium iodide was added to the mixture in the beaker and the timer started. a dark blue colour formed. the timer was stopped whenthe cross on the paper could not be seen. use the stop clock diagram to record the time in the table. experiment 2 by using a measuring cylinder 10 cm 3of potassium bromate solution was poured into a beaker. the instructions were repeated exactly as given for experiment 1, but 6 cm3of water was added to the beaker.use the diagram to record the time in the table.experiments 3, 4 and 5experiment 1 was repeated using the volumes of aqueous potassium bromate and water specified in the table of results. record the times in the table.for examiner\u2019s use",
            "5": "5 0620/06 o/n/03 [turn overtable of results [5]for examiner\u2019s use experiment volume clock diagram time/s potassium bromate/cm3water/cm3 11 2 4 21 0 6 38 8 46 1 0 54 1 200 301045 15 515minutes seconds 00 301045 15 515minutes seconds 00 301045 15 515minutes seconds 00 301045 15 515minutes seconds 00 301045 15 515minutes seconds",
            "6": "6 0620/06 o/n/03(a)plot the results on the grid. draw a smooth line graph. [4] (b)from your graph estimate the time of the reaction if experiment 1 was repeated using 5cm3of potassium bromate and 11 cm3of water. .. show clearly on your graph how you worked out your answers. [3] (c) (i) which experiment is the quickest? ... (ii) explain why this experiment is the quickest. .[3]024681012 20 40 time / svolume of potassium bromate /c m3 60 80 100for examiner\u2019s use",
            "7": "7 0620/06 o/n/03 [turn over(d) (i) state twopossible sources of error in the experiments. 1 . ... ... 2 . ... ... (ii) suggest twoimprovements to reduce the sources of error in the experiments. 1 . ... ... 2 . ... ...[4]for examiner\u2019s use",
            "8": "8 0620/06 o/n/034an aqueous solution of substance xwas analysed. substance xwas an iron( iii) salt containing one other cation. the tests on xand some of the observations are in the following table. complete the observations in the table.for examiner\u2019s use tests (a)colour of solution x (b) (i) drops of aqueous sodium hydroxide were added to about2c m 3of the solution. excess aqueous sodium hydroxide wasadded to the test-tube. (ii) the mixture was heated. thegas given off was tested withdamp indicator paper. [3] pungent smell indicator turned blue, ph 10 [2](c)experiment (b)(i) was repeated using aqueous ammonia instead of aqueous sodium hydroxide.dark yellowobservations (d)to about 2 cm3of solution xwas added dilute sulphuric acid. twopieces of zinc were added. themixture was heated and the gasgiven off tested. after 10 minutes the mixture was filtered and test (b)(i) was repeated. (e)a few drops of hydrochloric acidwere added to about 2 cm 3of solution x. about 1 cm3of barium chloride solution was added to themixture. white precipitatelighted splint popped green precipitate insoluble in excess",
            "9": "9 0620/06 o/n/03 [turn over(f) (i) name the gas given off in (d). ... (ii) what type of chemical reaction occurs in (d). explain your answer. ... ..[3] (g)what conclusions can you draw about the anion and the other cation in substance x? anion . ... cation  [2]for examiner\u2019s use",
            "10": "10 0620/06 o/n/035ammonia is produced when aqueous sodium hydroxide is warmed with ammonium sulphate. ammonia is less dense than air and very soluble in water. the apparatus belowwas used to prepare a sample of dry ammonia gas. (a)name substance c. ..[1] (b)name substance d. ..[1] (c)what necessary piece of equipment is missing in the diagram? ..[1] (d)suggest why concentrated sulphuric acid should notbe used to dry ammonia. ..[1] (e)there are two other mistakes in the apparatus shown in the diagram. identify andexplain these mistakes. mistake 1 .. explanation ...  mistake 2 ..explanation ... [4]ammonia concentrated sulphuric acidc dfor examiner\u2019s use",
            "11": "11 0620/06 o/n/036sulphur dioxide gas is a common pollutant formed when fossil fuels burn in air. sulphur dioxide can be detected by using an acidic solution of potassium dichromate( vi). the dichromate solution changes colour from orange to green when a certain amount of sulphurdioxide has reacted with it. plan an experiment to investigate which of three different samples of coal produces most sulphur dioxide. .. ..[6]for examiner\u2019s use",
            "12": "12 0620/06 o/n/03blank page"
        }
    },
    "2004": {
        "0620_s04_qp_1.pdf": {
            "1": "university of cambridge international examinations  international general certificate of secondary education  chemistry0620/01 paper 1  multiple choice  may/june 2004  45 minutes additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)                    read these instructions first   write in soft pencil.  do not use staples, paper clips, highlighters, glue or correction fluid.   write your name, centre number and candidate number on the answer sheet in the spaces provided   unless this has been done for you.  there are forty  questions on this paper. answer all questions.   for each question there are four possible answers  a,b,c, and d. choose the one you consider correct   and record your choice in soft pencil  on the separate answer sheet.  read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a mark will not be deducted for a wrong answer.   any rough working should be done in this booklet.   a copy of the periodic table is printed on page 16.  you may use a calculator.  this document consists of 16 printed pages.  ib04 06_0620_01/3rp   \uf6d9 ucles 2004 [turn over",
            "2": "2 \uf6d9 ucles 2004 0620/01/m/j/041 some students are asked to describe differences between gases and liquids.  three of their suggestions are:  1 gas molecules are further apart;  2 gas molecules are smaller;  3 liquid molecules vibrate around fixed positions.  which suggestions are correct?  a 1 only  b  2 only  c  3 only  d 1, 2 and 3  2 a coloured liquid vaporises easily at room temperature. some of the liquid is placed at the bottom  of a sealed gas jar.  which diagram shows the appearance of the jar after several hours?  3 measurements are made on some pure water.  its boiling point, b.p.  its freezing point, f.p.  its ph  sodium chloride is now dissolved in the water and the measurements repeated.  which measured values change?  b.p. f.p. ph  a \u0013\u0013\u0013 b \u0013\u0013\u0017 c \u0017\u0017\u0013 d \u0017\u0017\u0017ad c b coloured liquidcolouredvapourcolouredvapour colouredvapour",
            "3": "3 \uf6d9 ucles 2004 0620/01/m/j/04 [turn over4 the diagram shows a chromatogram obtained from three sweets, x, y and z.  sweet x sweet y sweet zyellow redred yellowred yellow red how many different red dyes are present in the sweets?  a 1 b2 c 3 d 4 5 which properties does a group vi element have?  forms covalent  bondsforms ionic  bondsconducts electricity  when solid  a \u0013\u0013 \u0013 b \u0017\u0013 \u0013 c \u0013\u0013 \u0017 d \u0013\u0017 \u0017",
            "4": "4 \uf6d9 ucles 2004 0620/01/m/j/046 the electronic structure of an element is shown.  ee eee e ee eeee eelectron nucleuskey which diagram shows the electronic structure of another element in the same group in the  periodic table?  eeee eeee eee ee ee eeee ee ee eeee e e ee eeb a d c 7 in the diagrams, circles of different sizes represent atoms of different elements.  which diagram can represent hydrogen chloride gas?  b a c d",
            "5": "5 \uf6d9 ucles 2004 0620/01/m/j/04 [turn over8 how many electrons are shared between the atoms in a molecule of methane, ch 4, and in a  molecule of water, h 2o? methane water  a 4 2  b 4 4  c 8 2  d 8 4  9 the oxide pb 3o4 reacts with dilute nitric acid to form lead( ii) nitrate, lead( iv) oxide and another  product. what is the equation for this reaction?  apb3o4 + 4hno 3\u2192 2pb(no 3)2 + pbo 2 + 2h 2o bpb3o4 + 2hno 3\u2192 2pbno 3 + pbo 4 + h 2 cpb3o4 + 4hno 3\u2192 pb(no 3)4 + 2pbo + 2h 2o d2pb 3o4 + 2hno 3\u2192 2pb 2no 3 + 2pbo 2 + h 2 10 the compound ethyl mercaptan, c 2h5sh, has a very unpleasant smell.  what is its relative molecular mass?  a 34  b  50  c  61  d  62  11 the proton number of helium is 2.  what information does this give about helium?  a its atom has two electrons.  b its atom is twice as heavy as a hydrogen atom.  c it is a group ii element. d its molecule has two atoms. ",
            "6": "6 \uf6d9 ucles 2004 0620/01/m/j/0412 in the circuit shown the bulb does not light.  carbon electrode solid copper( ii) sulphatecarbon electrode beakerbulb which change would cause the bulb to light?  a add more solid copper( ii) sulphate to the beaker  b add water to dissolve the copper( ii) sulphate  c replace the carbon electrodes with copper electrodes  d reverse the connections to the electrodes  13 the following electrolysis circuit is set up, using inert electrodes p, q, r ands. pq+       +        rs concentrated hydrochloric acidmolten lead( ii) bromide at which of the electrodes is a group v ii element produced?  a p only b p and r c q only d q and s 14 when it is used as a fuel, hydrogen combines with substance x. what is x? a carbon  b methane  c nitrogen d oxygen ",
            "7": "7 \uf6d9 ucles 2004 0620/01/m/j/04 [turn over15 the table compares the strengths of the bonds for reactions of the type below.  x2 + y 2\u2192 2xy  which reaction is most exothermic?  bonds in  x2bonds in  y2bonds in  xy a strong strong strong  b strong strong weak  c weak weak strong  d weak weak weak  16 in an experiment, copper( ii) oxide is changed to copper by a gas x.  what happens to the copper( ii) oxide and what is x? copper( ii) oxide gasx a oxidised carbon dioxide  b oxidised carbon monoxide  c reduced carbon dioxide  d reduced carbon monoxide  17 in an experiment, a 2g lump of zinc and 2g of powdered zinc are added separately to equal  volumes of dilute sulphuric acid.  the solid line on the graph shows the volume of gas given off when the 2g lump is used.  which dotted line is obtained when the zinc is powdered?  0 0 timevolume of gasa b c d",
            "8": "8 \uf6d9 ucles 2004 0620/01/m/j/0418 which process is endothermic?  a adding water to anhydrous copper( ii) sulphate  b burning magnesium to make the oxide  c heating water to make steam d neutralising acidic industrial waste  19 an aqueous solution contains either aluminium sulphate or zinc sulphate.  which aqueous reagent can be used to confirm which salt is present?  a ammonia  b barium chloride  c sodium hydroxide d sulphuric acid  20 compound x \u2022 does not dissolve in water, \u2022 does not react with water, \u2022 is used to control soil acidity.  what is x? a calcium carbonate  b calcium chloride  c calcium hydroxide d calcium oxide  21aqueous sodium hydroxide is added to two different solutions with the results shown.  xy green precipitate formed light blue precipitate formed which cation is present in x and in y?  x y  a ammonium iron( ii) b copper( ii) ammonium  c iron( ii) copper( ii) d iron( ii) ammonium ",
            "9": "9 \uf6d9 ucles 2004 0620/01/m/j/04 [turn over22 the diagrams show the arrangement of electrons in three different atoms.  e3 2 1 key electron nucleuse ee e ee ee e eee eee ee which atoms are metals?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3  23 which property do all metals have?  a they are hard.  b they conduct electricity.  c they form acidic oxides.  d they react with water.  24 the diagram shows a light bulb.  filamen t argon why is argon used instead of air in the light bulb?  a argon is a good conductor of electricity.  b argon is more reactive than air.  c the filament glows more brightly. d the filament lasts for a longer time. ",
            "10": "10 \uf6d9 ucles 2004 0620/01/m/j/0425 which element is likely to be a transition metal?  melting point inoc density in g / cm3 colour of oxide  a 98  1.0  white  b 328  11.3  yellow  c 651  1.7  white  d 1240  7.4  black  26 three metals are extracted as shown in the table.  metal method of extraction  x electrolyse molten metal oxide  y heat metal oxide with carbon   z occurs naturally as the metal   what is the order of reactivity of the metals?  most reactive  least reactive  a x y z  b x z y  c y z x  d z x y  27 haematite is reduced to iron in the blast furnace.  haematite + carbon monoxide \u2192 iron + x what is x? a carbon  b carbon dioxide  c hydrogen  d oxygen  28 which object is least  likely to contain aluminium?  a a bicycle frame  b a hammer  c a saucepan d an aeroplane body ",
            "11": "11 \uf6d9 ucles 2004 0620/01/m/j/04 [turn over29 a sample of clean, dry air is passed over hot copper until all the oxygen in the air reacts with the  copper. copper heatclean dry air the volume of air decreases by 30cm3. what was the starting volume of the sample of air?  a60cm3 b 100 cm3 c 150 cm3 d 300 cm3 30the ph of some aqueous sodium hydroxide is measured. the solution is then distilled as shown.  distillate collectedheatnaoh(aq)thermometer flask how do the ph values of the distillate and of the solution left in the flask compare with the  original? ph of the distillate ph of the solution  left in the flask  a higher higher  b higher lower  c lower higher  d lower lower ",
            "12": "12 \uf6d9 ucles 2004 0620/01/m/j/0431 which two gases produced from the burning of petrol in motor vehicles contribute to the formation  of acid rain?  a carbon dioxide and carbon monoxide  b carbon monoxide and sulphur dioxide  c carbon monoxide and nitrogen dioxide d nitrogen dioxide and sulphur dioxide  32 an old railway carriage is being restored. metal strips are secured on to the outside of the  wooden carriage by means of screws. after a few weeks open to the wind and rain, the screws  are heavily corroded but the metal strips are not.  woodmetal strip metalscrew aluminium is more reactive than both steel and copper.  which two metals would give this result?  screws strips  a aluminium steel  b copper aluminium  c copper steel  d steel aluminium  33 the diagram shows how oxygen is used in welding.  flame oxygen, o 2gas, x what is gas x ? a acetylene  b argon  c neon  d nitrogen ",
            "13": "13 \uf6d9 ucles 2004 0620/01/m/j/04 [turn over34 the diagrams show the growth of four plants.  nh4cl(aq)after treatment before treatment (nh4)2so4(aq) nano3(aq) na2so4(aq) which element is acting as a fertiliser?  a c l b n c na d s ",
            "14": "14 \uf6d9 ucles 2004 0620/01/m/j/0435 gas is released in all of the examples below.  fermenting grapesacid rain on a limestone statuea dog pantingwine a candle burning which gas do they all produce?  a carbon dioxide  b hydrogen  c methane d oxygen  36 what is formed when calcium carbonate is heated?  a calcium and carbon  b calcium and carbon dioxide  c calcium oxide and carbon  d calcium oxide and carbon dioxide  37 which compound contains three elements?  a ethanol  b ethene  c methane d poly(ethene) ",
            "15": "15 \uf6d9 ucles 2004 0620/01/m/j/0438 four fractions obtained from crude oil (petroleum) are listed below.  which fraction is paired with a correct use?   fraction use  a bitumen making waxes  b diesel fuel for aircraft  c lubricating making roads  d paraffin fuel for oil stoves  39 the structures of three compounds are shown.  hhh hchh hh c cc cchhc h hhhhhhh hh c cchhc hhc why do these substances all belong to the same homologous series?  a they all contain an even number of carbon atoms.  b they all contain the same functional group.  c they are all hydrocarbons. d they are all saturated.  40 the table shows some suggested reactions involving ethanol.  which suggestions about the reactants and products are correct?  reaction reactants products  a ethanol and oxygen carbon dioxide and water  b ethene and steam ethanol and hydrogen  c glucose and oxygen ethanol and carbon dioxide  d glucose and water ethanol and oxygen ",
            "16": "16 university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles) which is itself a department of  the university of cambridge.  0620/01/m/j/04group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s04_qp_2.pdf": {
            "1": "centre number candidate number name university of cambridge international examinations international general certificate of secondary education chemistry0620/02 paper 2 may/june 2004 1 hour 15 minutes candidates answer on the question paper. no additional materials required. read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen in the spaces provided on the question paper. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. answer all questions. the number of marks is given in brackets [  ] at the end of each question or part question. a copy of the periodic table is printed on page 16. for examiner\u2019s use 1 2 3 4 5 6 total this document consists of 16 printed pages. ib04 06_0620_02/2rp /g211 ucles 2004 [turn overif you have been given a label, look at the details. if any details are incorrect o r missing, please fill in your correct details in the space given at the top of this page. stick your personal label here, if provided.",
            "2": "2 /g211 ucles 2004 0620/02/m/j/04for examiner\u2019s use 1the diagram shows models of various structures, abc def (a)which three  of the structures a to f represent elements? give a reason for your answer. structures reason [2] (b)which one of the structures a to f represents a gas containing single atoms? [1] (c) (i) which one of the structures a to f represents a gas containing diatomic molecules? (ii) state the name of a gas which has diatomic molecules. [2] (d) (i) which one of the structures a to f represents graphite? (ii) state one use of graphite. [2] ",
            "3": "3 /g211 ucles 2004 0620/02/m/j/04 [turn overfor examiner\u2019s use (e)structure d represents a compound. (i)state what is meant by the term compound . (ii) which one of the following substances is structure e most likely to represent? put a ring around the correct answer. ammonia hydrogen chloride methane water [2] (f)hydrogen chloride is a compound. (i)draw a diagram to show how the electrons are arranged in a molecule of hydrogen chloride. show only the outer electrons. show hydrogen electrons as /g183 show chlorine electrons as   x [2] (ii) state the name of the type of bonding present in hydrogen chloride. [1] (iii) hydrogen chloride dissolves in water to form an acidic solution (hydrochloric acid). describe how you would use litmus paper to show that this solution is acidic. [2] (iv) which one of the following values is most likely to represent the ph of a dilutesolution of hydrochloric acid? put a ring around the correct answer. ph 2 ph7 ph10 ph14 [1]",
            "4": "4 /g211 ucles 2004 0620/02/m/j/04for examiner\u2019s use (v) complete the following equation for the reaction of hydrochloric acid with magnesium. mg(s) + hc l (aq) /g174 mgc l2(aq) +h 2(g) [1] (vi) name the salt formed in this reaction. [1] ",
            "5": "5 /g211 ucles 2004 0620/02/m/j/04 [turn overfor examiner\u2019s use2two of the stages in water purification are filtration and chlorination. the diagram below shows a filter tank. sandstones water outimpure water in (a)explain how this filter helps purify the water. [2] (b) (i) why is chlorine added during water purification? (ii) after chlorination, the water is acidic. a small amount of slaked lime is added to theacidic water. explain why slaked lime is added. (iii) what is the chemical name for slaked lime? (iv)  state one other use of slaked lime. [4] ",
            "6": "6 /g211 ucles 2004 0620/02/m/j/04for examiner\u2019s use(c) (i) state the boiling point of pure water. [2] (ii) describe a chemical test for water. test [1] result [1] (iii) state one use of water in the home. [1] (d)the diagram shows the arrangement of particles in the three different states of water. a b c which of these diagrams, a,b or c, shows water in a solid state? [1] (e)steam reacts with ethene in the presence of a catalyst. complete the word equation for this reaction. ethene + steam /g174 [1] (f)potassium reacts violently with water. complete the word equation for this reaction.potassium + water /g174 + [2] ",
            "7": "7 /g211 ucles 2004 0620/02/m/j/04 [turn overfor examiner\u2019s use3when lumps of calcium carbonate react with hydrochloric acid, carbon dioxide gas is released. caco 3(s) + 2hc l(aq) /g174 cac l2(aq) +c o 2(g) + h 2o(l) (a)describe a practical method for investigating this reaction, which would enable you tocalculate the rate of reaction. [4] (b)what effect will the following have on the rate of the reaction? (i)increasing the temperature (ii) adding water to the acid (iii) using powdered calcium carbonate instead of lumps [3] (c)describe a test for calcium ions. resulttest [3] ",
            "8": "8 /g211 ucles 2004 0620/02/m/j/04for examiner\u2019s use(d)calcium can be obtained by the electrolysis of molten calcium chloride. (i)suggest why calcium must be extracted by electrolysis rather than by reduction with carbon. [1] (ii) draw the electronic structure of an atom of calcium. [2]",
            "9": "9 /g211 ucles 2004 0620/02/m/j/04 [turn overfor examiner\u2019s use4organic substances have many uses. (a)match the substances in the boxes on the left with the descriptions in the boxes on the right. the first one has been done for you. liquid used as a solvent used for making roads gas used as a fuel gas used in making polymersmethane ethanol ethene bitumen [3] (b)which one of the following would be least likely to be obtained from the fractionaldistillation of petroleum? put a ring around the correct answer. bitumen ethane ethanol methane [1]",
            "10": "10 /g211 ucles 2004 0620/02/m/j/04for examiner\u2019s use(c)some reactions of organic compounds are shown below. a n ch 2=ch 2 b c3h8 + 5o 2 c c6h12o6 glucose d(   ch 2    ch 2)n 3co 2 + 4h 2o 2co 2 + 2c 2h5oh c6h14 + c 2h4 c8h18 (i)which one of the reactions, a, b,c or d, shows fermentation? (ii) which one of the reactions, a, b,c or d, shows polymerization? (iii) which one of the reactions, a, b,c or d, shows combustion? (iv) which one of the reactions, a, b,c or d, shows cracking? [4] (d)the hydrocarbon c 8h18is an alkane. (i)what is meant by the term hydrocarbon ? (ii) explain why this hydrocarbon is an alkane. [2] ",
            "11": "11 /g211 ucles 2004 0620/02/m/j/04 [turn overfor examiner\u2019s use 5look at the list of five elements below. argon brominechlorineiodine potassium (a)put these five elements in order of increasing proton number. [1] (b)put these five elements in order of increasing relative atomic mass. [1] (c)the orders of proton number and relative atomic mass for these five elements are different. which one of the following is the most likely explanation for this? tick one box. the proton number of a particular element may vary. the presence of neutrons. the atoms easily gain or lose electrons. the number of protons must always equal the number ofneutrons. [1] (d)which of the five elements in the list are in the same group of the periodic table? [1] (e) (i) from the list, choose one element which has one electron in its outer shell. [1] (ii) from the list, choose one element which has a full outer shell of electrons. [1] ",
            "12": "12 /g211 ucles 2004 0620/02/m/j/04for examiner\u2019s use (f)which twoof the following statements about argon are correct? tick two boxes. argon is a noble gas. argon reacts readily with potassium. argon is used to fill weather balloons. argon is used in light bulbs. [2] (g)potassium chloride can be made by reacting potassium with chlorine. the bonding in potassium chloride is ionic. what does this information tell you about (i)the boiling point of potassium chloride, [1] (ii) the electrical conductivity of molten potassium chloride? [1] (h)describe the change in the electronic structure of potassium and chlorine atoms when they combine to make potassium chloride. change in potassium atom chan ge in chlorine atom [2] ",
            "13": "13 /g211 ucles 2004 0620/02/m/j/04 [turn overfor examiner\u2019s use 6iron is extracted from its ore in a blast furnace using carbon (coke) as a reducing agent and as a source of heat. (a)the coke burns in hot air. the equation for this reaction is 2c(s) + o 2(g) /g174 2co(g) state the name of the gas produced in this reaction. [1] (b)near the top of the blast furnace, the iron(iii ) oxide in the iron ore gets reduced to iron. fe2o3(s) + 3co(g) /g174 2fe(l) + 3co 2(g) use the equation to explain why the change of iron( iii) oxide to iron is a reduction reaction. [1] (c)in the hottest regions of the furnace, iron( iii) oxide is reduced by carbon. complete the equation for this reaction.fe 2o3(s) + c(s) /g174 fe(l) + 3co(g) [2] ",
            "14": "14 /g211 ucles 2004 0620/02/m/j/04for examiner\u2019s use (d)the iron from the blast furnace contains up to 10% by mass of impurities. the main impurities are carbon, silicon and phosphorus. the diagram below shows one method of making steel from iron. molten iron from blast furnaceslag formingoxygen and powdered basic oxides a mixture of oxygen and basic oxides is blown onto the surface of the molten iron. (i)what is the purpose of blowing oxygen onto the molten iron? [1] (ii) a large amount of energy is released in the process of steelmaking. what name is given to chemical reactions which release energy? [1] (iii) the basic oxides react with the impurities in the iron and form a slag. what information in the diagram suggests that the slag is less dense than the molten iron? [1] (iv) which one of the following is a basic oxide?put a ring around the correct answer. calcium oxide carbon dioxide sulphur dioxide water [1] (v) why is steel rather than iron used for constructing buildings and bridges? [1] ",
            "15": "15 /g211 ucles 2004 0620/02/m/j/04for examiner\u2019s use (e)special steels contain added elements such as vanadium, chromium, cobalt or nickel. these are all transition metals. state three properties of transition metals which are not shown by non-transition metals. 1. 2. 3. [3] (f)what is the name given to metals which are mixtures of more than one metal? [1] ",
            "16": "16 university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles) which is itself a department of the university of cambridge. /g211 ucles 2004 0620/02/m/j/04group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s04_qp_3.pdf": {
            "1": "centre number candidate number name      university of cambridge international examinations  international general certificate of secondary education  chemistry paper 3  may/june 2004  1 hour 15 minutes candidates answer on the question paper.   no additional materials required.                     read these instructions first   write your centre number, candidate number and name on all the work you hand in.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.   you may use a calculator.   answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part question.   a copy of the periodic table is printed on page 12.  for examiner\u2019s use  1 2 3 4 5 6 7 total this document consists of 12 printed pages.  ib04 06_0620_03/4rp   \uf6d9 ucles 2004 [turn overif you have been given a label, look at the  details. if any details are incorrect or missing, please fill in your correct details in  the space given at the top of this page.  stick your personal label here, if provided. ",
            "2": "2 \uf6d9 ucles 2004 0620/03/m/j/04 for examiner\u2019s use 1it was reported from america that a turbine engine, the size of a button, might replace  batteries. the engine would be built from silicon which has suitable properties for this  purpose. (a) (i) why are batteries a convenient source of energy?  [1] (ii) the engine will run on a small pack of jet fuel. what other chemical is needed to  burn this fuel?  [1] (b)silicon has the same type of macromolecular structure as diamond.  (i)explain why one atom of either element can form four covalent bonds.  [2]   (ii) predict two physical properties of silicon.  [2]   (iii) name a different element that has a similar structure and properties to silicon.  [1] (c) silicon is made by the carbon reduction of the macromolecular compound, silicon( iv) oxide.   (i) balance the equation for the reduction of silicon( iv) oxide.    sio 2 +  c \u2192 si +  co [1]    (ii) explain why the silicon( iv) oxide is said to be reduced.  [1]   (iii) describe the structure of silicon( iv) oxide. you may use a diagram.  [2] ",
            "3": "3 \uf6d9 ucles 2004 0620/03/m/j/04 [turn overfor examiner\u2019s use 2sulphur is used to make sulphuric acid. in the uk, the annual production of the acid is  about 2.5 million tonnes.   (a) the reactions in the manufacture of sulphuric acid by the contact process are shown below.   sulphur  sulphur dioxide     s reaction 1 so 2   sulphur dioxide + oxygen sulphur trioxide     2so 2 + o 2 reaction 2 2so 3   sulphur trioxide oleum     so 3 reaction 3 h2s2o7   oleum + water sulphuric acid     h 2s2o7 reaction 4 h2so 4   (i) give a large scale source of the element sulphur.  [1] (ii) state another use of sulphur dioxide.  [1]   (iii) how is sulphur changed into sulphur dioxide?  [1]   (iv) name the catalyst used in reaction 2. [1]   (v) reaction 2 is exothermic. why is a catalyst, rather than a higher temperature, used  to increase the rate of this reversible reaction?  [2]   (vi) write a word equation for reaction 3. [1]   (vii) write a symbol equation for reaction 4. [1] ",
            "4": "4 \uf6d9 ucles 2004 0620/03/m/j/04 for examiner\u2019s use  (b) about one third of this production of acid is used to make nitrogen and phosphorus- containing fertilisers.    (i) name the third element that is essential for plant growth and is present in most fertilisers. [1]   (ii) name a nitrogen-containing fertiliser that is manufactured from sulphuric acid.  [1]   (iii) rock phosphate (calcium phosphate) is obtained by mining. it reacts with concentrated sulphuric acid to form the fertiliser, superphosphate. predict the  formula of each of these phosphates.    fertiliser ions formula    calcium phosphate ca 2+ and po 43\u2013      calcium superphosphate ca2+ and h 2po 4\u2013 [2] (iv) the ionic equation for the reaction between the phosphate ion and sulphuric acid  is shown below.     po 43\u2013   +   2h 2so 4\u2192   h 2po 4\u2013   +   2hso 4\u2013    explain why the phosphate ion is described as acting as a base in this reaction.  [2] 3an organic compound decomposes to form nitrogen.  c6h5n2cl(aq) \u2192 c6h5cl(l) + n 2(g)  (a) explain the state symbols.  aq l g [2]  (b) draw a diagram to show the arrangement of the valency electrons in one molecule of  nitrogen. [2]",
            "5": "5 \uf6d9 ucles 2004 0620/03/m/j/04 [turn overfor examiner\u2019s use  (c) the rate of this reaction can be measured using the following apparatus.  20 40 60 80 100cm3 solution of organic compoundnitrogen gas   the results of this experiment are shown on the graph below.  timevolume ofnitrogen 0 0   (i) how does the rate of this reaction vary with time?  [1] (ii) why does the rate vary?  [2]   (iii) the reaction is catalysed by copper powder. sketch the graph for the catalysed  reaction on the same grid. [2]    (iv) why is copper powder more effective as a catalyst than a single piece of copper?  [1] ",
            "6": "6 \uf6d9 ucles 2004 0620/03/m/j/04 for examiner\u2019s use 4 (a) insoluble compounds are made by precipitation.    (i) complete the word equation for the preparation of zinc carbonate.          + \u2192 +    sodium carbonatezinccarbonate   [2]   (ii) complete the following symbol equation.   pb(no 3)2 +  nac l\u2192  +  [2]   (iii) write an ionic equation for the precipitation of the insoluble salt, silver( i) chloride.  [2]  (b) 2.0 cm3 portions of aqueous sodium hydroxide were added to 4.0 cm3 of aqueous  iron( iii) chloride. both solutions had a concentration of 1.0 mol/dm3. after each  addition, the mixture was stirred, centrifuged and the height of the precipitate of iron( iii) hydroxide was measured. the results are shown on the following graph.    (i) complete the ionic equation for the reaction.    fe3+ + \u2026..oh\u2013\u2192   [1]   (ii) on the same grid, sketch the graph that would have been obtained if iron( ii) chloride had been used instead of iron( iii) chloride? [2] 8 76543210 02468 1 0 1 2 1 4 1 6height of precipitateof metalhydroxide/ mm volume of aqueous sodium hydroxide / cm 3",
            "7": "7 \uf6d9 ucles 2004 0620/03/m/j/04 [turn overfor examiner\u2019s use   (iii) if aluminium chloride had been used instead of iron( iii) chloride, the shape of the  graph would be different. how are the shapes of these two graphs different and  why? difference in shape   reason for difference   [2] 5 (a) copper has the structure of a typical metal. it has a lattice of positive ions and a \u201csea\u201d  of mobile electrons. the lattice can accommodate ions of a different metal.    give a different  use of copper that depends on each of the following.    (i) the ability of the ions in the lattice to move past each other  [1]   (ii) the presence of mobile electrons  [1]   (iii) the ability to accommodate ions of a different metal in the lattice  [1]  (b) aqueous copper( ii) sulphate solution can be electrolysed using carbon electrodes. the  ions present in the solution are as follows.  cu2+(aq),       so 42\u2013 (aq),       h+(aq),       oh\u2013 (aq)    (i) write an ionic equation for the reaction at the negative electrode (cathode).  [1]   (ii) a colourless gas was given off at the positive electrode (anode) and the solution  changes from blue to colourless.     explain these observations.  [2] ",
            "8": "8 \uf6d9 ucles 2004 0620/03/m/j/04 for examiner\u2019s use  (c) aqueous copper( ii) sulphate can be electrolysed using copper electrodes. the  reaction at the negative electrode is the same but the positive electrode becomes  smaller and the solution remains blue.    (i) write a word equation for the reaction at the positive electrode.  [1]   (ii) explain why the colour of the solution does not change.  [2]   (iii) what is the large scale use of this electrolysis?  [1] ",
            "9": "9 \uf6d9 ucles 2004 0620/03/m/j/04 [turn overfor examiner\u2019s use 6in 2002, swedish scientists found high levels of acrylamide in starchy foods that had been  cooked above 120oc. acrylamide, which is thought to be a risk to human health, has the  following structure.  cch hhconh 2  (a) (i) it readily polymerises to polyacrylamide. draw the structure of this polymer.  [2]   (ii) starch is formed by polymerisation. it has a structure of the type shown below.  name the monomer.  oo [1]   (iii) what are the differences between these two polymerisation reactions, one forming polyacrylamide and the other starch?  [2]  (b) acrylamide hydrolyses to form acrylic acid and ammonium ions.    (i) describe the test for the ammonium ion.  test result  [2]   (ii) given an aqueous solution, concentration 0.1 mol / dm3, how could you show that  acrylic acid is a weak acid.  [2] ",
            "10": "10 \uf6d9 ucles 2004 0620/03/m/j/04 for examiner\u2019s use  (c) the structural formula of acrylic acid is shown below. it forms compounds called  acrylates. cch hcoohh   (i) acrylic acid reacts with ethanol to form the following compound.  cchhcooch 2ch3 h    deduce the name of this compound. what type of organic compound is it?  name type of compound  [2]   (ii) acrylic acid is an unsaturated compound. it will react with bromine. describe the  colour change and draw the structural formula of the product of this addition  reaction. colour change   structural formula of product  [2]",
            "11": "11 \uf6d9 ucles 2004 0620/03/m/j/04for examiner\u2019s use 7chemists use the concept of the mole to calculate the amounts of chemicals involved in a  reaction.  (a) define mole . [1]  (b) 3.0 g of magnesium was added to 12.0g of ethanoic acid.    mg + 2ch 3cooh\u2192 (ch 3coo) 2mg + h 2   the mass of one mole of mg is 24g.   the mass of one mole of ch 3cooh is 60 g.   (i) which one, magnesium or ethanoic acid, is in excess? you must show your  reasoning. [3]   (ii) how many moles of hydrogen were formed?  [1]   (iii) calculate the volume of hydrogen formed, measured at r.t.p.  [2]  (c) in an experiment, 25.0cm3 of aqueous sodium hydroxide, 0.4mol / dm3, was neutralised  by 20.0cm3 of aqueous oxalic acid, h 2c2o4. 2naoh + h 2c2o4\u2192 na 2c2o4 +2h 2o   calculate the concentration of the oxalic acid in mol/ dm3.   (i) calculate the number of moles of naoh in 25.0cm3 of 0.4 mol/ dm3 solution.  [1]   (ii) use your answer to (i) and the mole ratio in the equation to find out the number of  moles of h 2c2o4 in 20 cm3 of solution.  [1]   (iii) calculate the concentration, mol/ dm3, of the aqueous oxalic acid.  [2] ",
            "12": "12 university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles) which is itself a department of  the university of cambridge.  \uf6d9 ucles 2004 0620/03/m/j/04 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57 *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x= atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s04_qp_5.pdf": {
            "1": "centre number candidate number name      university of cambridge international examinations  international general certificate of secondary education  chemistry0620/05 paper 5  practical test  may/june 2004  1 hour 15 minutes candidates answer on the question paper.   additional materials: as listed in instructions to supervisors                     read these instructions first   write your name, centre number and candidate number in the spaces at the top of this page.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.   you may use a calculator.   answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part questions.   practical notes are provided on page 8.  for examiner\u2019suse  1 2 total this document consists of 8 printed pages.  ib04 06_0620_05/4rp   \uf6d9 ucles  2004 [turn overif you have been given a label, look at the  details. if any details are incorrect or missing, please fill in your correct details in  the space given at the top of this page.  stick your personal label here, if provided. ",
            "2": "2 \u00a9 ucles 2004 0620/05/m/j/04 for examiner\u2019s use1 you are going to investigate the temperature changes that occur when two compounds, a andb, react with hydrochloric acid.   read all the instructions below carefully before starting the experiments.  move cup standhydrochloric acidplastic cupthermometer add solidclamp  instructions  experiment 1   using a measuring cylinder, add 30cm3 of the hydrochloric acid provided to the plastic cup.   in the table record the initial temperature of the acid.   start the timer, and using a spatula, add some of the solid a to the cup. stir the mixture by  moving the cup (not the thermometer) until the fizzing stops (see diagram above). now add  some more of a. continue adding a in this way until all of solid a has been added.   during the addition of a, record the temperature of the mixture every 30 seconds/half  minute. it should take less than five minutes to add all of the solid. continue taking temperature readings for the full five minutes.   experiment 2   using the second plastic cup provided, a fresh supply of hydrochloric acid and solid b (instead of a), repeat experiment 1. ",
            "3": "3 \u00a9 ucles 2004 0620/05/m/j/04 [turn overfor examiner\u2019s use table of results   experiment 1  time/ minutes 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5  temperature/oc              [3]  experiment 2 time/ minutes 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5  temperature/oc              [3]",
            "4": "4 \u00a9 ucles 2004 0620/05/m/j/04 for examiner\u2019s use(a)plot your results for both experiments on the grid below. for each set of results draw a  smooth line graph. indicate clearly which line represents experiment 1 and which line experiment 2.  01234540 30 20 10 0 time / minutestemperature /oc [7]",
            "5": "5 \u00a9 ucles 2004 0620/05/m/j/04 [turn overfor examiner\u2019s use (b) from your graphs,   (i) find the temperature of the reaction mixture after the hydrochloric acid had  reacted for 2 minutes 15 seconds with  solid a, solid b. [2]   (ii) what type of chemical reaction occurs when  solid a, solid b. [2]    reacts with hydrochloric acid?   (c) give two observations in experiment 1, apart from temperature change.  1 2 [2]  (d) suggest what type of compound solids a and b are. explain your answer.  [2]  (e) if the plastic cup and final reaction mixture were left for one hour, predict the  temperature at this time for    (i) solid a and hydrochloric acid,    (ii) solid b and hydrochloric acid.     explain your answers.  [3] ",
            "6": "6 \u00a9 ucles 2004 0620/05/m/j/04 for examiner\u2019s use2 you are provided with a mixture of two solid compounds c and d, containing the same  metal cation.  c is partially soluble in water and d is soluble.   carry out the following tests on c and d, recording all of your observations in the table. do  not write any conclusions in the table.  tests observations  (a)note the appearance of the  mixture of c and d.  [1]      (b)add the mixture of c and d to  10 cm3 of distilled water in a  boiling-tube. stopper the tube  and shake for 1 minute. filter the mixture. keep the filtrate.  (c) divide the filtrate from (b) into  five approximately equal  portions. (i)to the first portion add  drops of aqueous sodium  hydroxide, a little at a time, with shaking.  [2]  [1]        add excess aqueous  sodium hydroxide.  (ii) to the second portion  add excess aqueous ammonia, a little at a time. [1] (iii) to the third portion add  about 1cm3 of dilute  sodium hydroxide and  aluminium powder.  carefully boil the mixture and test the gas with  damp indicator paper. [3] (iv) test the ph of the fourth  portion with indicator paper.[1] (v) using a straw blow into  the fifth portion. [1]     ",
            "7": "7 \u00a9 ucles 2004 0620/05/m/j/04 [turn overfor examiner\u2019s use (d) what conclusions can you draw about the identity of the metal cation in c and d? [1]  (e) name the gas given off in (c)(iii) . [1]  (f) suggest an explanation for the observation in (c)(v) . [2]  (g) what conclusions can you draw about the identity of the anions in solid c and d? [2] ",
            "8": "8 university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.  \u00a9 ucles 2004 0620/05/m/j/04 notes for use in qualitative analysis test for anions anion test test result  carbonate (co-2 3)add dilute acid effervescence, carbon dioxide  produced chloride (c l\u2013) [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013) [in solution] acidify with dilute nitric acid, then aqueous lead( ii) nitrate yellow ppt.  nitrate (no\u2212 3) [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulphate (so-2 4) [in solution] acidify with dilute nitric acid, then aqueous barium nitrate white ppt.  test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh+ 4) ammonia produced on warming -  calcium (ca2+) white., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution  test for gases gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint "
        },
        "0620_s04_qp_6.pdf": {
            "1": "centre number candidate number name      university of cambridge international examinations  international general certificate of secondary education  chemistry0620/06 paper 6  alternative to practical  may/june 2004  1 hour  candidates answer on the question paper.   no additional materials required.                     read these instructions first   write your name, centre number and candidate number at the top of this page.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.   answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part question.  for examiner\u2019s use  1 2 3 4 5 6 7 8 total this document consists of 12 printed pages.  ib04 06_0620_06/3rp   \uf6d9 ucles  2004 [turn overif you have been given a label, look at the  details. if any details are incorrect or  missing, please fill in your correct details in the space given at the top of this page.  stick your personal label here, if provided. ",
            "2": "2 \uf6d9 ucles 2004 0620/06/m/j/04 for examiner\u2019s use1an experiment was carried out to find the ph of samples of soil from a farmer\u2019s field.  soil samplewater filtrateuniversal indicatorc a b  (a) identify the pieces of apparatus labelled  a, b, c. [3]  (b) why was the soil crushed?  [2] ",
            "3": "3 \uf6d9 ucles 2004 0620/06/m/j/04 [turn overfor examiner\u2019s use (c) why should soil samples be taken from different parts of the field?  [1]  (d) suggest why it is important to know the ph of soil.  [1] 2the four tubes show an investigation of rusting.  each one of these four tubes contains a  nail and the reagents indicated.  cork cork waterdistilled water (boiled to remove dissolved oxygen)dry oxygenair oxygen 1234  (a) predict the order in which rust would appear.  firstsecond [1]  (b) explain your prediction.  [2] ",
            "4": "4 \uf6d9 ucles 2004 0620/06/m/j/04 for examiner\u2019s use3lead bromide was placed in a tube and connected to an electrical circuit as shown below.  bulbdc power supply heatlead bromide toxic  the lead bromide was heated until molten. a brown gas was given off.  (a) state one other expected observation.  [1] (b) (i) suggest a suitable material for the electrodes.  (ii) indicate on the diagram the negative electrode (cathode). [2]   (c) name the brown gas. at what electrode will the gas be given off?  nameelectrode [2]  (d) why is this experiment carried out in a fume cupboard?  [1] ",
            "5": "5 \uf6d9 ucles 2004 0620/06/m/j/04 [turn overfor examiner\u2019s use4a student investigated the temperature changes that occur when two compounds a and b, react with hydrochloric acid.  the apparatus below was used.  move cup standhydrochloric acidplastic cupthermometer add solidclamp  experiment 1   by using a measuring cylinder, 30cm3of hydrochloric acid was added to the plastic cup.   use the thermometer diagram to record the initial temperature of the acid in the table.  the  timer was started, and some of the solid a was added to the cup.  immediate effervescence  occurred.  the mixture was stirred by moving the cup until the fizzing stopped.   more of a was then added and the student continued adding a in this way until all of solid a had been added.   use the thermometer diagrams to record the temperature of the mixture every half minute.  experiment 2   experiment 1 was repeated using solid b.  use the thermometer diagrams to record the  temperatures in the table. ",
            "6": "6 \uf6d9 ucles 2004 0620/06/m/j/04 for examiner\u2019s usetable of results   experiment 1  time/min 0.0 0.5 1.0 1.5 2.0 2.5 thermometer diagram temperature /oc25 2015353025 353025302520302520 302520302520302520 302520353025 3530253.0 3.5 4.0 4.5 5.0 [2]  experiment 2  252015252015201510 201510201510 201510201510201510 20151015105 15105time/min 0.0 0.5 1.0 1.5 2.0 2.5 thermometer diagram temperature /oc 3.0 3.5 4.0 4.5 5.0 [2]",
            "7": "7 \uf6d9 ucles 2004 0620/06/m/j/04 [turn overfor examiner\u2019s use(a)plot the results from both experiments on the grid below.  for each set of results draw  a smooth line graph.  indicate clearly which line represents experiment 1 and which line experiment 2 [6]  01234540 30 20 10 0 time / minutestemperature /oc",
            "8": "8 \uf6d9 ucles 2004 0620/06/m/j/04 for examiner\u2019s use (b) from your graphs ;   (i) find the temperature of the reaction mixture after the hydrochloric acid had  reacted for 2 minutes 15 seconds with  solid a, solid b.[ 2] (ii) what type of chemical reaction occurs when  solid a, solid b    reacts with hydrochloric acid? [2]   (c) suggest what type of compound solids a and b are.  explain your answer  [2]  (d) if the plastic cup and final reaction mixture are left for one hour, predict the temperature  at this time for  (i)solid a and hydrochloric acid,  (ii)solid band hydrochloric acid.    explain your answers.  [3] ",
            "9": "9 \uf6d9 ucles 2004 0620/06/m/j/04 [turn overfor examiner\u2019s use5a mixture of two calcium compounds candd was tested.  c is partially soluble in water and d is soluble in water.   complete the observations in the table.  tests observations  the mixture of c and d was added to  distilled water in a boiling tube.  the  tube was shaken.  the mixture was  filtered. (a) the filtrate was divided into five  equal portions.  (i)to the first portion was  added drops of aqueous  sodium hydroxide, a little at  a time, with shaking. [2] excess aqueous sodium  hydroxide was added. [1] (ii)to the second portion was  added excess aqueous  ammonia, a little at a time. [1] (iii)to the third portion was  added dilute sodium hydroxide and aluminium  powder.  the mixture was  boiled and the gas tested  with damp litmus paper.  red litmus went blue  (iv)the ph of the fourth portion  was tested with indicator paper.  ph about 10   (v) carbon dioxide was bubbled  through the fifth portion.  solution turned milky/cloudy  (b)name the gas given off in (a)(iii) . [1] (c) suggest an explanation for the observation in (a)(v) . [1] ",
            "10": "10 \uf6d9 ucles 2004 0620/06/m/j/04 for examiner\u2019s use(d) what conclusions can you draw about the identity of the anions in solid c and d? [2] 6copper oxide was reacted with hydrogen using the apparatus shown below.  excess hydrogen burning in air colourlessliquidiceheatdry hydrogen  (a) indicate on the diagram with an arrow where the copper oxide is placed. [1]  (b) the colour of the copper oxide would change from  to  [2]  (c) what is the purpose of the ice?  [2] ",
            "11": "11 \uf6d9 ucles 2004 0620/06/m/j/04 [turn overfor examiner\u2019s use7describe a chemical test to distinguish  between each of the following pairs of substances.   an example is given.   potassium chloride and potassium iodide    test: add aqueous lead( ii) nitrate    result: potassium chloride gives a white precipitate, potassium iodide gives a yellow  precipitate (a) water and ethanol  test result with water  result with ethanol [2] (b)sulphuric acid and aqueous sodium sulphate testresult with sulphuric acid  result with aqueous sodium sulphate [2] (c)hydrochloric acid and nitric acid  test result with hydrochloric acid  result with nitric acid [2] ",
            "12": "12 university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles) which is itself a  department of the university of cambridge.  \uf6d9 ucles 2004 0620/06/m/j/04 for examiner\u2019s use8 is manganese( iv) oxide a catalyst? a catalyst is a substance that speeds up a chemical reaction and remains unchanged.   hydrogen peroxide, h 2o2 breaks down to form oxygen. this reaction is very slow without a  catalyst.  describe an experiment to show that manganese( iv) oxide is a catalyst for this  reaction.  you are provided with the following items.    hydrogen peroxide solution   manganese( iv) oxide    measuring cylinder   balance    beaker    filtration apparatus    splints/bunsen burner    distilled water  [6] "
        },
        "0620_w04_qp_1.pdf": {
            "1": "university of cambridge international examinations international general certificate of secondary education chemistry0620/01 paper 1  multiple choice october/november 2004 45 minutes additional materials: multiple choice answer sheet soft clean eraser soft pencil (type b or hb is recommended) read these instructions first write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless this has been done for you. there are forty  questions on this paper. answer all questions. for each question there are four possible answers  a, b, c, and d. choose the one you consider correct and record your choice in soft pencil on the separate answer sheet. read the instructions on the answer sheet very carefully. each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator. this document consists of 16 printed pages. /g211 ucles 2004 [turn over",
            "2": "2 /g211 ucles 2004 0620/1/o/n/041when steam at 100  oc condenses to water at 25  oc, what happens to the water molecules? athey move faster and closer together. bthey move faster and further apart. cthey move slower and closer together. dthey move slower and further apart. 2the melting points and boiling points of four substances are shown. which substance is liquid at 100  oc? substance melting point  / oc boiling point  / oc a \u2013203 \u201317 b \u201325 50 c 11 181 d 463 972",
            "3": "3 /g211 ucles 2004 0620/1/o/n/04 [turn over3the apparatus shown cannot  be used to determine the melting point of sodium chloride, na+cl \u2013. thermometer heatwater thin glass tube containingsodium chloride why is this? melting point of sodium chloride is greater than 100  ocsodium chloride dissolves in the water a /g51/g51 b /g51/g55 c /g55/g51 d /g55/g55 4a student wishes to extract a coloured solution from some berries to make an indicator solution. which of the listed instructions should the student follow? 1 crush the berries 2 add acid 3 add a solvent 4 filter the mixture 5 distil the filtrate a1, 2 and 4 b1, 3 and 4 c2, 3 and 5 d2, 4 and 5",
            "4": "4 /g211 ucles 2004 0620/1/o/n/045hydrogen and helium have isotopes, as shown. in which of these isotopes does the nucleus have twice as many neutrons as protons? ah2 1 bh3 1 c he3 2 d he4 2 6how are the electrons arranged in a neon atom , ne, and a sodium ion, na+? 7which compound has ionic bonds? ahydrogen chloride bmethane csodium chloride dwaterneon atom a bcdsodium ion e eeeeee eeee ee eeeeee ee eeeeee ee eeeeeeee ee ee eeeeee ee eeeeeeee ee eeeeeeee ee eeeeeeee ee eelectron nucleusekey",
            "5": "5 /g211 ucles 2004 0620/1/o/n/04 [turn over8which diagram shows an atom in the same group of the periodic table as sodium? eee eee e eeee eee ee ee eeee eeeeeee eee ekey an electron nucleusabcd 9when propane is burned, carbon dioxide and water are formed, as shown. c3h8 + 5o 2 /g174 r  co 2 + s h2o which values of r and s balance the equation? rs a 13 b 15 c 34 d 38 10which formula represents a compound containing three atoms? ahno 3 bh2o clif dznso 4 11a substance x is heated in an evaporating basin until there is no further change. mass of basin and contents before heating 25.52  g after heating 26.63  g what could x be? acopper bcopper( ii) carbonate ccopper( ii) oxide dhydrated copper( ii) sulphate",
            "6": "6 /g211 ucles 2004 0620/1/o/n/0412aluminium is extracted from its oxide by electrolysis. which words correctly complete the spaces? the oxide is dissolved in \u2026\u20261\u2026\u2026 cryolite and aluminium is deposited at the \u2026\u20262\u2026\u2026 space 1 space 2 a aqueous negative cathode b aqueous positive anode c molten negative cathode d molten positive anode 13the diagram shows an electrolysis experiment using metals x and y as electrodes. aqueous solution xy+_ one of the metals becomes coated with copper.which metal becomes coated and which aqueous solution is used? metalaqueous solution ax crc l3 bx cuc l2 cy crc l3 dy cuc l2",
            "7": "7 /g211 ucles 2004 0620/1/o/n/04 [turn over14the solvent ethanol is produced by the fermentation of sugar, using yeast. which graph correctly shows how the speed of fermentation changes with temperature? 15in which process does an endothermic change take place? acombustion bevaporation cfiltration dneutralisationspeed of fermentation temperature  / oc temperature  / oc temperature  / oc temperature  / oc00 100b speed of fermentation 00 100a speed of fermentation 00 100c speed of fermentation 00 100d",
            "8": "8 /g211 ucles 2004 0620/1/o/n/0416the sign        is used in some equations to show that a reaction can be reversed. two incomplete equations are given. reagents products p coc l 2 + 2h 2oc o c l 2. 2h 2o q c + o 2 co 2 for which of these reactions can a        sign be correctly used to complete the equation? pq a/g51/g51 b/g51/g55 c/g55/g51 d/g55/g55 17in which reaction does reduction of the underlined substance take place? acu2o + c /g174 2cu + co b2cu 2o + o 2 /g174 4cuo c2cu + o 2 /g174 2cuo dcuo + co /g174 cu + co 2 18in which experiment is the rate of reaction between hydrochloric acid and calcium carbonate slowest ? water at 30  ocdilute hydrochloric acid lumps of calcium carbonatea water at 30  occoncentrated hydrochloric acid lumps of calcium carbonatecwater at 60  ocdilute hydrochloric acid powdered calcium carbonateb water at 60  occoncentrated hydrochloric acid powdered calcium carbonated",
            "9": "9 /g211 ucles 2004 0620/1/o/n/04 [turn over19aqueous ammonia is added to a solution of a metal sulphate. a green precipitate that is insoluble in excess of the aqueous ammonia forms. which metal ion is present? aca2+bcu2+cfe3+dfe2+ 20the chart shows the colour ranges of four different indicators. which indicator is blue in an acidic solution? 21an ion x in solution is identified as shown. heatdamp red litmusstays red solution x + naoh(aq) heatdamp redlitmusturns blue solution x + naoh(aq) metal powder what is ion x? aal 3+  (aq) bnh 4+  (aq) cno 3\u2013  (aq) dso 42\u2013  (aq)indicator a bcd1 2 3 4 5 6 7 8 9 10 11 12 13 14ph value yellow yellowblue red redblue blue blue colourless",
            "10": "10 /g211 ucles 2004 0620/1/o/n/0422metals can be joined together by welding them at a high temperature. why is an argon atmosphere often used? aargon has a low density. bargon is colourless. cargon is inexpensive. dargon is unreactive. 23part of the reactivity series is outlined below. aluminium carbon ironlead hydrogenincreasing reactivity copper electrolysis is an expensive way of extraction. which metal has to be extracted from its ore by electrolysis? aaluminium bcopper clead diron",
            "11": "11 /g211 ucles 2004 0620/1/o/n/04 [turn over24the diagram shows part of the periodic table. xz y which statement about elements x, y and z is correct? the proton number of x is aseven less than that of z. bthree less than that of z. cone less than that of y. dsixteen less than that of y. 25three different metals, cu, fe and mg, are each added to an excess of dilute hydrochloric acid.the graph shows how rapidly hydrogen is given off. 0timevolume of hydrogen12 3 which metal gives which curve? 123 a fe cu mg b fe mg cu c mg cu fe d mg fe cu",
            "12": "12 /g211 ucles 2004 0620/1/o/n/0426which substance is a metal? electrical conductivity (solid)electrical conductivity (molten) a high high b high low c low high d low low 27which changes occur when impure iron is made into stainless steel? carbon chromium a added added b added removed c removed added d removed removed 28the bodies of an aeroplane, a car and a wheelbarrow are made of metal. which metal is used for which body? aeroplane car wheelbarrow a aluminium iron steel b aluminium steel iron c steel aluminium iron d steel iron aluminium 29what is used to test for the presence of water? aanhydrous copper( ii) sulphate baqueous barium chloride caqueous sodium hydroxide duniversal indicator paper",
            "13": "13 /g211 ucles 2004 0620/1/o/n/04 [turn over30a candle is burned in a fixed volume of air. how do the percentages (%) of carbon dioxide and oxygen change? carbon dioxide oxygen a fall fall b fall rise c rise fall d rise rise 31anhydrous calcium chloride is used as a drying agent.an alkaline solution of pyrogallol absorbs oxygen and carbon dioxide. clean air is passed through the apparatus shown. clean air alkaline pyrogallolanhydrous calciumchloride which gases are present in the air leaving the apparatus? argon nitrogen hydrogen a /g51/g51/g51 b /g51/g55/g51 c /g55/g51/g51 d /g51/g51/g55 32which chart could represent the composition of a galvanised roof? carbon ironb carbonirona ironcarbonzincd carbonironzincc",
            "14": "14 /g211 ucles 2004 0620/1/o/n/0433which statement explains why iron is used as the catalyst in the manufacture of ammonia? amore ammonia is produced in a given time. bthe catalyst is unchanged at the end of the reaction. cthe catalyst neutralises the ammonia. dthe purity of the ammonia is improved. 34a sample of acid rainwater (ph  = 4) is passed down a glass column packed with marble chippings (calcium carbonate). the water coming from the bottom of the column is collected in a beaker. the ph is now 6. rainwate r marble chippings water what causes the change in ph? athe acid has been filtered. bthe acid has been neutralised. cthe acid is made more concentrated. dthe acid is precipitated. 35what are the products when limestone (calcium carbonate) is strongly heated?acalcium hydroxide and carbon dioxide bcalcium hydroxide and carbon monoxide ccalcium oxide and carbon dioxide dcalcium oxide and carbon monoxide 36which compound is ethanol? ch ho h ha ch hc hhho hb h c oo hc ch hc h oo hd",
            "15": "15 /g211 ucles 2004 0620/1/o/n/0437what is petroleum? aan aircraft fuel ba central heating fuel ca mixture of carbohydrates da mixture of hydrocarbons 38methanol and ethanol belong to the same homologous series. what does this mean?atheir molecules contain atoms only of carbon and hydrogen. btheir molecules have the same number of carbon atoms. cthey have the same functional group. dthey have the same relative molecular mass. 39which substances can be obtained by cracking hydrocarbons?aethanol and ethene bethanol and hydrogen cethene and hydrogen dethene and poly(ethene) 40the apparatus shown may be used to study the products of fermentation. fermenting solutionaqueous calciumhydroxide what is the purpose of the aqueous calcium hydroxide? ato absorb any excess of yeast bto condense the ethanol produced cto prevent air entering the system dto show that carbon dioxide is produced",
            "16": "16 university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles) which is itself a department of the university of cambridge. 0620/1/o/n/04group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89                9 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w04_qp_2.pdf": {
            "1": "centre number candidate number name university of cambridge international examinations international general certificate of secondary education chemistry0620/02 paper 2 october/november 2004 1 hour 15 minutes candidates answer on the question paper. no additional materials required. read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen in the spaces provided on the question paper. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. you may use a calculator. answer all questions. the number of marks is given in brackets [  ] at the end of each question or part question. a copy of the periodic table is provided on page 16. for examiner\u2019s use 1 2 3 4 5 6 total this document consists of 15 printed pages and 1 blank page. ib04 11_0620_02/3rp /g211 ucles 2004 [turn overif you have been given a label, look at the details. if any details are incorrect o r missing, please fill in your correct details in the space given at the top of this page. stick your personal label here, if provided.",
            "2": "2 /g211 ucles 2004 0620/02/o/n/04for examiner\u2019s use1the table below gives some information about the elements in group i of the periodic table. element boiling point / oc density / g  cm/g1503radius of atom in the metal / nmreactivity with water lithium 1342 0.53 0.157 sodium 883 0.97 0.191 rapid potassium 760 0.86 0.235 very rapid rubidium 1.53 0.250 extremely rapid caesium 669 1.88 explosive (a)how does the density of the group i elements change down the group? [2] (b)suggest a value for the boiling point of rubidium. [1] (c)suggest a value for the radius of a caesium atom. [1] (d)use the information in the table to suggest how fast lithium reacts with water compared with the other group i metals. [1] (e)state three properties shown by all metals. 1. 2. 3. [3] ",
            "3": "3 /g211 ucles 2004 0620/02/o/n/04 [turn overfor examiner\u2019s use(f)when sodium reacts with water, hydrogen is given off. 2na(s)   +    2h 2o(l)     /g174      2naoh(aq)      +      h 2(g) (i)state the name of the other product formed in this reaction. [1] (ii) describe a test for hydrogen. test result [2] (g)the diagrams below show three types of hydrogen atom. +n+nn+ hydrogen deuterium tritium (i)state the name of the positively charged particle in the nucleus. [1] (ii) what is the name given to atoms with the same number of positive charges in the nucleus but different numbers of neutrons? [1] (iii) state the number of nucleons in a single atom of tritium. [1] (iv) tritium is a radioactive form of hydrogen. state one medical use of radioactivity. [1] ",
            "4": "4 /g211 ucles 2004 0620/02/o/n/04for examiner\u2019s use2the structures of some compounds found in plants are shown below. hnh hco oh hchhhhc o oc hhhc hhc ho hcc c cchh hhhh h h hcch hhhbc dea (a)which two of these compounds are unsaturated hydrocarbons? [1] (b)which two of these compounds contain a carboxylic acid functional group? [1] (c)write the molecular formula for compound d. [1] (d)draw the structure of the product formed when compound a reacts with bromine. show all atoms and all bonds. [1]",
            "5": "5 /g211 ucles 2004 0620/02/o/n/04 [turn overfor examiner\u2019s use(e)strawberry fruits produce compound a (ethene) naturally. a scientist left some green strawberry fruits to ripen. the scientist measured the concentration of ethene and carbon dioxide produced by the strawberry fruits over a ten day period. the graph below shows the results. 0 02468 1 0100200300400 daysconcentration of gas/partsper million(ppm) carbon dioxide ethene (i)between which two days does the rate of ethene production increase most rapidly? [1] (ii) what is the name given to the process in which carbon dioxide is produced by living organisms? put a ring around the correct answer. acidification combustion neutralization respiration [1] (iii) carbon dioxide concentration over 350  ppm has an effect on ethene production by the fruits.what effect is this? [1] (iv) ethene gas spreads throughout the fruit by a random movement of molecules.what is the name given to the random movement of molecules? put a ring around the correct answer. aeration diffusion evaporation ionisation [1]",
            "6": "6 /g211 ucles 2004 0620/02/o/n/04for examiner\u2019s use(v) ethene gas promotes the ripening of strawberry fruits. ripening of strawberries is slowed down by passing a stream of nitrogen over the fruit. suggest why this slows down the ripening process. [1] (vi) enzymes are involved in the ripening process. what is an enzyme ? [2] (f)plants make a variety of coloured pigments. a student extracted red colouring from four different plants, r, s, t and u. the student put a spot of each colouring on a piece of filter paper.the filter paper was dipped into a solvent and left for 30 minutes.the results are shown below. rstu rstustart of experiment result after 30 minutes filter paper solvent (i)what is name given to the process shown in the diagram? [1] (ii) which plant contained the greatest number of different pigments? [1] (iii) which two plants contained the same pigments? [1] ",
            "7": "7 /g211 ucles 2004 0620/02/o/n/04 [turn overfor examiner\u2019s use3read the following instructions for the preparation of hydrated nickel( ii) sulphate (niso 4.7h 2o), then answer the questions which follow. 1put 25  cm3 of dilute sulphuric acid in a beaker. 2heat the sulphuric acid until it is just boiling then add a small amount of nickel( ii) carbonate. 3when the nickel( ii) carbonate has dissolved, stop heating, then add a little more nickel carbonate. continue in this way until nickel( ii) carbonate is in excess. 4filter the hot mixture into a clean beaker. 5make the hydrated nickel( ii) sulphate crystals from the nickel( ii) sulphate solution. the equation for the reaction is nico 3(s)     +    h 2so 4(aq)    /g174    niso 4(aq)     +    co 2(g)    +   h 2o(l) (a)what piece of apparatus would you use to measure out 25  cm3 of sulphuric acid? [1] (b)why is the nickel( ii) carbonate added in excess? [1] (c)when nickel( ii) carbonate is added to sulphuric acid, there is a fizzing. explain why there is a fizzing. [1] (d)draw a diagram to describe step 4. you must label your diagram. [3]",
            "8": "8 /g211 ucles 2004 0620/02/o/n/04for examiner\u2019s use(e)after filtration, which one of the following describes the nickel( ii) sulphate in the beaker? put a ring around the correct answer. crystals filtrate precipitate water [1] (f)explain how you would obtain pure dry crystals of hydrated nickel( ii) sulphate from the solution of nickel( ii) sulphate. [2] (g)when hydrated nickel( ii) sulphate is heated gently in a test tube, it changes colour from green to white. (i)complete the symbol equation for this reaction. niso 4.7h 2o(s) niso 4(s) + [1] (ii)what does the sign mean? [1] (iii) how can you obtain a sample of green nickel( ii) sulphate starting with white nickel( ii) sulphate? [1] ",
            "9": "9 /g211 ucles 2004 0620/02/o/n/04 [turn overfor examiner\u2019s use4the table below shows the composition of the mixture of gases coming from a typical car exhaust. gas% of the gas in the exhaust fumes carbon dioxide 9 carbon monoxide 5 oxygen 4 hydrogen 2 hydrocarbons 0.2 nitrogen oxides 0.2 sulphur dioxide less than 0.003 gas x 79.6 (a)state the name of the gas x. [1] (b)the carbon dioxide comes from the burning of hydrocarbons, such as octane, in thepetrol. (i)complete the word equation for the complete combustion of octane. octane + /g174 carbon dioxide + [2] (ii) which two chemical elements are present in hydrocarbons? [1] (iii) to which homologous series of hydrocarbons does octane belong? [1] (c)suggest a reason for the presence of carbon monoxide in the exhaust fumes. [1] ",
            "10": "10 /g211 ucles 2004 0620/02/o/n/04for examiner\u2019s use(d)nitrogen oxides are present in small quantities in the exhaust fumes. (i)complete the following equation for the formation of nitrogen dioxide. n2(g) + o2(g)/g174 no 2(g) [1] (ii) state one harmful effect of nitrogen dioxide on organisms. [1] (e)sulphur dioxide is an atmospheric pollutant which is only found in small amounts in car exhausts. (i)what is the main source of sulphur dioxide pollution of the atmosphere? [1] (ii) sulphur dioxide is oxidised in the air to sulphur trioxide. the sulphur trioxide may dissolve in rainwater to form a dilute solution of sulphuric acid, h 2so 4. state the meaning of the term oxidation . [1] (iii) calculate the relative molecular mass of sulphuric acid. [1] (iv) sulphuric acid reacts with metals such as iron. complete the following word equation for the reaction of sulphuric acid with iron. sulphuric acid + iron /g174 + [2] (v) what effect does acid rain have on buildings made of stone containing calcium carbonate? [1] ",
            "11": "11 /g211 ucles 2004 0620/02/o/n/04 [turn overfor examiner\u2019s use5fertilizers often contain ammonium nitrate. (a) (i) what effect do fertilizers have on crops? [1] (ii) name one metal ion which is commonly present in fertilizers. [1] (iii) which one  of the following ions is commonly present in fertilizers? put a ring around the correct answer. bromide chloride hydroxide phosphate [1] (b)describe a test for nitrate ions. test result [4] (c)ammonium nitrate can be made by adding nitric acid to a solution of ammonia. (i)what type of reaction is this? [1] (ii) complete the symbol equation for this reaction. + hno 3(aq)/g174nh 4no 3(aq) [1] (d)which two of the following statements about ammonia are true?tick two boxes. ammonia is insoluble in water ammonia turns red litmus blue a solution of ammonia in water has a ph of 7 ammonia has a molecular structure [2]",
            "12": "12 /g211 ucles 2004 0620/02/o/n/04for examiner\u2019s use6the electrolysis of a concentrated solution of sodium chloride, provides us with chemicals. (a)sodium chloride has an ionic giant structure. which one  of the following is a correct description of a property of sodium chloride. tick one  box. sodium chloride has a low melting point sodium chloride conducts electricity when it is solid sodium chloride has a high boiling point sodium chloride is insoluble in water [1] (b) (i) explain what is meant by the term electrolysis . [1] (ii) at which electrode is hydrogen produced during the electrolysis of aqueous sodium chloride? [1] (iii) name a suitable substance that can be used for the electrodes. [1] (c) (i) state the name of the particle which is added to a chlorine atom to make a chloride ion. [1] (ii) describe a test for chloride ions. test result [2] ",
            "13": "13 /g211 ucles 2004 0620/02/o/n/04 [turn overfor examiner\u2019s use(d)if chlorine is allowed to mix with sodium hydroxide, sodium chlorate( i), naocl is formed. balance the equation for this reaction. cl2+n a o h /g174 nac l+naoc l+h 2o [1] (e)one tonne (1  000  kg) of a commercial solution of sodium hydroxide produced by electrolysis contains the following masses of compounds. compound mass of compound kg/ tonne sodium hydroxide 510 sodium chloride 10 sodium chlorate( v) 9 water 471 total 1000 (i)how many kilograms of sodium hydroxide will be present in 5 tonnes of the solution? [1] (ii) all the water from one tonne of impure sodium hydroxide is evaporated. what would the approximate percentage of the remaining impurities be? put a ring around the correct answer. 0.036% 3.6% 36% 96% [1]",
            "14": "14 /g211 ucles 2004 0620/02/o/n/04for examiner\u2019s use(f)the hydrogen obtained by electrolysis can be used in the manufacture of margarine. ch hchh cchh co 2h h nchh chh hhcchh co 2h h +   h 2 nni (i)complete the following sentences about this reaction using words from the list. catalyst inhibitormonomericsaturated unsaturated hydrogen gas is bubbled through carbon compounds using a nickel which speeds up the reaction. the mar garines produced are compounds. [3] (ii) state one other use of hydrogen. [1] ",
            "15": "15 0620/02/o/n/04blank page",
            "16": "16 university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles) which is itself a department of the university of cambridge. /g211 ucles 2004 0620/02/o/n/04group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89                9 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w04_qp_3.pdf": {
            "1": "this document consists of 15 printed pages and 1 blank page.  ib04 11_0620_03rep/rp   \u00a9 ucles  2004        [turn over   university of cambridge international examinations   international general certificate of secondary education       chemistry       paper 3 0620/03        october/november 2004       1 hour 15 minutes   candidates answer on the question paper.   no additional materials required.                                 read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen.  you may use a pencil for any diagrams, graphs or rough working.  write in the boxes provided on the question paper  do not  write in the barcode.  do not  write in the grey areas between the pages.  do not use staples, paper clips, highlighters, glue or correction fluid.  you may use a calculator.    answer all questions.  the number of marks is given in brackets [  ] at the end of each question   or part questions.  a copy of the periodic table is printed on page 16. for examiner's use 1 2345678 totalcandidate name centrenumber candidatenumbe r*062003*",
            "2": "2  .    \u00a9 ucles 2004 0620/03/o/n/04 for  examiner\u2019s  use 1 (a)  two of the gases in air are nitrogen and oxygen. name two other gases present in  unpolluted air.    [2]       (b) two common pollutants present in air are sulphur dioxide and lead compounds. state the source and harmful effect of each.    sulphur dioxide   source  harmful effect [3]    lead compounds    source  harmful effect [2]      (c) respiration and photosynthesis are two of the processes that determine the percentage  of oxygen and of carbon dioxide in the air.     (i) name another process that changes the percentages of these two gases in air.    [1]     (ii) the equation for photosynthesis is given below.    6co 2 + 6h 2o    c6h12o6 + 6o 2    this is an endothermic reaction.   complete the reaction for respiration.   c 6h12o6 + 6o 2   +         this is an reaction.      [2]   ",
            "3": "3  \u00a9 ucles 2004 0620/03/o/n/04 [turn over  for  examiner\u2019s  use  (d) the rate of photosynthesis of pond weed can be measured using the following  experiment.    gas collects bubbles pond weed water containing dissolvedcarbon dioxidegraduatedtube       (i) describe how you could show that the gas collected in this experiment is oxygen.    [1]     (ii) what measurements are needed to calculate the rate of this reaction?    [2]    (iii) what would be the effect, and why, of moving the apparatus further away from the  light?    [2]   ",
            "4": "4  .    \u00a9 ucles 2004 0620/03/o/n/04 for  examiner\u2019s  use 2 the salt copper( ii) sulphate can be prepared by reacting copper( ii) oxide with sulphuric  acid.     complete the list of instructions for making copper( ii) sulphate using six of the words below.    blue cool dilute filter   saturated sulphate white oxide      instructions   1 add excess copper( ii) oxide to  sulphuric acid in a   beaker and boil it.      2  to remove the unreacted copper( ii) oxide.    3 heat the solution until it is   .    4  the solution to form        coloured crystals of copper ( ii)  . [6]   ",
            "5": "5  \u00a9 ucles 2004 0620/03/o/n/04 [turn over  for  examiner\u2019s  use 3 the simplest alcohol is methanol.     (a) it is manufactured by the following reversible reaction.    co (g) + 2h 2 (g)  ch 3oh (g)   300  oc   30atm    (i) reversible reactions can come to equilibrium. explain the term equilibrium .      [1]    (ii) at 400  oc, the percentage of methanol in the equilibrium mixture is lower than at   300  oc. suggest an explanation.    [2]    (iii) suggest two advantages of using high pressure for this reaction.   give a reason for each advantage.    advantage   reason    advantage  reason  [5]      ",
            "6": "6  .    \u00a9 ucles 2004 0620/03/o/n/04 for  examiner\u2019s  use (b) (i) complete the equation for the combustion of methanol in an excess of oxygen.    ch 3oh + o 2  +[ 2]   (ii) complete the word equation.    methanol + ethanoic acid    +   [2]       (iii) methanol can be oxidised to an acid. name this acid.    [1]     ",
            "7": "7  \u00a9 ucles 2004 0620/03/o/n/04 [turn over  for  examiner\u2019s  use 4 in the following list of ionic equations, the metals are in order of reactivity.       +    zn  zn2+ + 2e\u2013   sn  sn2+ + 2e\u2013  reactivity of metals increases hg  hg2+ + 2e\u2013   ag  ag+ + e\u2013      (a) (i) in the space at the top of the series, write an ionic equation that includes a more  reactive metal. [1]      (ii) define oxidation  in terms of electron transfer.      [1]     (iii) explain why the positive ions are likely to be oxidising agents.    [1]     (iv) which positive ion(s) can oxidise mercury metal (hg)?    [1]      ",
            "8": "8  .    \u00a9 ucles 2004 0620/03/o/n/04 for  examiner\u2019s  use (b) the following diagram shows a simple cell.    vvoltmeter zinc electrode tin electrode electrolyte dilute sulphuric acid       (i) predict how the voltage of the cell would change if the tin electrode was replaced with a silver one.    [1]      (ii) which electrode would go into the solution as positive ions? give a reason for your choice.    [1]      (iii) state how you can predict the direction of the electron flow in cells of this type.    [1]   ",
            "9": "9  \u00a9 ucles 2004 0620/03/o/n/04 [turn over  for  examiner\u2019s  use 5 strontium and sulphur chlorides both have a formula of the type xc l  2 but they have  different properties.    property strontium chloride sulphur chloride  appearance white crystalline solid red liquid  melting point / oc 873 -80  particles present ions molecules  electrical conductivity of solid poor poor  electrical conductivity of liquid good poor      (a) the formulae of the chlorides are similar because both elements have a valency of 2.  explain why group ii and group vi elements both have a valency of 2.    [2]     (b) draw a diagram showing the arrangement of the valency electrons in one covalent  molecule of sulphur chloride.    use x to represent an electron from a sulphur atom.   use o to represent an electron from a chlorine atom.   [3]    (c) explain the difference in electrical conductivity between the following.     (i) solid and liquid strontium chloride    [1]     (ii) liquid strontium chloride and liquid sulphur chloride    [1]   ",
            "10": "10  .    \u00a9 ucles 2004 0620/03/o/n/04 for  examiner\u2019s  use 6 polymers are extensively used in food packaging. poly(dichloroethene) is used because gases can only diffuse through it very slowly. polyesters have a high thermal stability and food can be cooked in a polyester bag.    (a) (i) the structure of poly(dichloroethene) is given below.    hclcchcl n       draw the structural formula of the monomer.        (ii) explain why oxygen can diffuse faster through the polymer bag than carbon  dioxide can.       [2]    (b) (i) a polyester can be formed from the monomers ho-ch 2ch 2-oh and     hooc-c 6h4-cooh. draw the structure of this polyester.        [2]           [1] ",
            "11": "11  \u00a9 ucles 2004 0620/03/o/n/04 [turn over  for  examiner\u2019s  use (ii)  name a naturally occurring class of compounds that contains the ester linkage.     [1]      (iii) suggest what is meant by the term thermal stability.        [1]       (c) (i) describe two environmental problems caused by the disposal of plastic (polymer)  waste.         [2]   (ii) the best way of disposing of plastic waste is recycling to form new plastics. what  is another advantage of recycling plastics made from petroleum?     [1]     ",
            "12": "12  .    \u00a9 ucles 2004 0620/03/o/n/04 for  examiner\u2019s  use 7 (a)  (i) write a symbol equation for the action of heat on zinc hydroxide.        [2]       (ii) describe what happens when solid sodium hydroxide is heated strongly.     [1]    (b) what would be observed  when copper( ii) nitrate is heated?       [3]   (c)  iron( iii) sulphate decomposes when heated. calculate the mass of iron( iii) oxide  formed and the volume of sulphur trioxide produced when 10.0  g of iron( iii) sulphate  was heated.   mass of one mole of fe 2(so 4)3 is 400  g.    fe2(so 4)3 (s)    fe 2o3 (s) + 3so 3 (g)    number of moles of fe 2(so 4)3 =   number of moles of fe 2o3 formed =  mass of iron( iii) oxide formed = g   number of moles of so 3 produced =  volume of sulphur trioxide at r.t.p. = dm3[5]   ",
            "13": "13  \u00a9 ucles 2004 0620/03/o/n/04 [turn over  for  examiner\u2019s  use 8 the alkenes are a homologous series of unsaturated hydrocarbons.     (a) the table below gives the names, formulae and boiling points of the first members of the series.    name formula boiling point  / oc  ethene c 2h4 -102  propene c 3h6 -48  butene c 4h8 -7  pentene c 5h10 30  hexene       (i) complete the table by giving the formula of hexene and by predicting its boiling point.  [2]    (ii) deduce the formula of the alkene which has a relative molecular mass of 168. show your working.    [2]   (b) describe a test that will distinguish between the two isomers, but-2-ene and cyclobutane.      test   result with but-2-ene   result with cyclobutane  [3]     ",
            "14": "14  .    \u00a9 ucles 2004 0620/03/o/n/04 for  examiner\u2019s  use (c) alkenes undergo addition reactions.      (i) what class of organic compound is formed when an alkene reacts with water?    [1]     (ii) predict the structural formula of the compound formed when hydrogen chloride reacts with but-2-ene.      [1]          (iii) draw the structure of the polymer formed from but-2-ene.      [2]                    ",
            "15": "15  every reasonable effort has been made to trace all copyright holders where the publishers (i.e. ucles) are aware that third-par ty material has been  reproduced. the publishers would be pleased to hear from any one whose rights they have unwittingly infringed.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.        0620/03/o/n/04  blank page",
            "16": "16  \u00a9 ucles 2004 0620/03/o/n/04 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89                9 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w04_qp_5.pdf": {
            "1": "this document consists of 7 printed pages and 1 blank page.  ib04 11_0620_05/3rp   \u00a9 ucles  2004  [turn over   university of cambridge international examinations   international general certificate of secondary education       chemistry       paper 5 practical test 0620/05        october/november 2004      candidates answer on the question paper.   additional materials:  as listed in instructions  1 hour 15 minutes    to supervisors                                     read these instructions first    write your name, centre number and candidate number on all the work you hand in.  write in dark blue or black pen in the spaces provided on the question paper.  you may use a pencil for any diagrams, graphs or rough working.  do not  write in the barcode.  do not  write in the grey areas between the pages.  do not use staples, paper clips, highlighters, glue or correction fluid.   you may use a calculator.  answer all questions.  the number of marks is given in brackets [  ] at the end of each question or part question.   practical notes are provided on page 8.  candidate name centrenumber candidatenumbe r*062005*    for examiner's use total1 2",
            "2": "2  \u00a9 ucles 2004 0620/05/o/n/04 for  examiner\u2019s  use 1 you are going to investigate what happens when sodium thiosulphate dissolves in water.     read all the instructions  below carefully before starting the experiments.    instructions     experiment 1    place a polystyrene cup in the beaker provided.     by using a measuring cylinder, pour 20  cm3 of the distilled water into the polystyrene cup  provided and record the temperature of the water in the table.     add the 1  g of powdered sodium thiosulphate provided to the cup and stir the mixture with  the thermometer.  measure and record the temperature of the solution after one minute.   pour the solution away and rinse the polystyrene cup.    experiment 2    repeat experiment 1 using 2  g of the powdered sodium thiosulphate provided.    record your results in the table.     experiments 3, 4 and 5    repeat experiment 1 using 3  g, 4  g and 5  g of powdered sodium thiosulphate respectively.   record your results in the table.    table of results    temperature  / oc  mass of sodium thiosulphate /  g  initial final  1    2    3    4    5      [5] ",
            "3": "3  \u00a9 ucles 2004 0620/05/o/n/04  [turn over  for  examiner\u2019s  use  (a) plot the results of the experiments on the grid below.  draw a best-fit straight line  graph.    01234540 30 20 10 0 mass of thiosulphate  / gfinal temperature  / oc 6    [5]   ",
            "4": "4  \u00a9 ucles 2004 0620/05/o/n/04 for  examiner\u2019s  use  (b) (i) use your graph  to estimate the temperature of the reaction mixture if 3.5  g of  powdered sodium thiosulphate were added to 20  cm3 of water.       indicate clearly  on the graph how you obtained your answer.    [2]      (ii) from your graph work out the temperature of the reaction mixture if 6  g of  powdered sodium thiosulphate were added to 20  cm3 of water.      indicate clearly  how you used your graph.    [2]      (c) what type of chemical reaction occurs when sodium thiosulphate dissolves in water?    [1]      (d) explain how the temperature changes would differ in the experiments if 40  cm3 of water  were used.        [2]       (e) explain why the sodium thiosulphate was powdered before being used.      [2]       (f) predict what the temperature of the reaction mixture in experiment 5 would be after 1  hour.  explain your answer.      [2]      (g) suggest one change you could make to the apparatus  used in the experiments to  obtain more accurate results.      [1]     ",
            "5": "5  \u00a9 ucles 2004 0620/05/o/n/04  [turn over  for  examiner\u2019s  use 2 you are provided with salt e.     carry out the following tests on e, recording all of your observations in the table.  do not  write any conclusions in the table.    tests observations   (a) describe the appearance of e  [2]                [2]  appearance     (b) using a spatula place about half of e in a hard glass test- tube. inside the top of the tube suspend a piece of damp indicator paper. heat e gently  until gas comes out of the  tube.     leave the tube to cool and  study its appearance.   [2]       dissolve the rest of e in about 6  cm3  of water.     (c) test the ph of the solution  using indicator paper.  [1]            (d) divide the solution into three test- tubes.    (i) to the first portion, add a few drops of dilute nitric  acid and about 1  cm3 of  aqueous silver nitrate.   [2]   (ii) to the second portion of  solution e, add about        1 cm3 of lead nitrate  solution.  [2]          [2]   (iii) to the third portion of  solution e, add about       1 cm3 of aqueous sodium  hydroxide. boil gently   and test the gas given off  with indicator paper.         (e) name the gas given off in test (d)(iii) .    [1]   ",
            "6": "6  \u00a9 ucles 2004 0620/05/o/n/04 for  examiner\u2019s  use  (f) explain the observations in test (b).      [2]       (g) what conclusions can you draw about salt e?      [2]   ",
            "7": "7   0620/05/o/n/04   blank page ",
            "8": "8      every reasonable effort has been made to trace all copyright holders. the publishers would be pleased to hear from anyone whose  rights we have unwittingly  infringed.   university of cambridge international examinations is part of  the university of cambridge local examinations syndicate (ucles), which is itself a department  of the university of cambridge .      \u00a9 ucles 2004 0620/05/o/n/04 notes for use in qualitative analysis   test for anions   anion test test result  carbonate (co-2 3) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then aqueous lead( ii) nitrate yellow ppt.  nitrate (no\u2212 3)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulphate (so-2 4)  [in solution] acidify with dilute nitric acid, then  aqueous barium nitrate white ppt.  test for aqueous cations   cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh+ 4) ammonia produced on warming -  calcium (ca2+) white., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving a colourless solution  test for gases   gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_w04_qp_6.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry         paper 6  alternative to practical    october/november 2004        1 hour    candidates answer on the question paper.     no additional materials required.                           read these instructions first     write your name, centre number and candidate number at the top of this page.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     you may use a calculator.     answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part question.                           for examiner\u2019s use   1    2    3    4    5    6    7    total       this document consists of 11 printed pages and 1 blank page.  ib04 11_0620_06/3rp   \uf6d9 ucles  2004  [turn over    if you have been given a label, look at the  details. if any details are incorrect or  missing, please fill in your correct details in the space given at the top of this page.    stick your personal label here, if provided.   ",
            "2": "2  \uf6d9 ucles 2004 0620/06/o/n/04 for  examiner\u2019s  use 1 the apparatus below was used to make hydrogen. dilute hydrochloric acid was added to zinc.      watera b      (a) identify the pieces of apparatus labelled  a,   b.   [2]     (b) complete the boxes [1]       (c) give a test for hydrogen.  test   result   [2]     ",
            "3": "3  \uf6d9 ucles 2004 0620/06/o/n/04  [turn over  for  examiner\u2019s  use 2 the addition of calcium carbonate to excess dilute nitric acid produces carbon dioxide. the  volume of carbon dioxide given off at 20 second intervals was recorded and plotted on the  grid.    0 2 04 06 08 0 1 0 0120 100140 80 60 2040 0 time  / secondsvolume of carbon dioxide  / cm3 120      (a) draw a smooth line graph on the grid. [1]      (b) circle the result which appears to be incorrect? why have you selected this result?        [2]       (c) why does the reaction slow down?    [1]  ",
            "4": "4  \uf6d9 ucles 2004 0620/06/o/n/04 for  examiner\u2019s  use 3 a liquid alkane was passed over heated aluminium oxide to make ethene.     waterliquid alkane and mineral woolaluminiumoxide very strong heatethene        (a) what is the purpose of the mineral wool?    [1]      (b) what is this type of chemical reaction called?    [1]     (c) give a test for ethene.  test   result   [2]     (d) what precaution should be taken in the experiment when the heat is removed? explain.        [2]     ",
            "5": "5  \uf6d9 ucles 2004 0620/06/o/n/04  [turn over  for  examiner\u2019s  use 4 a student investigated what happened when sodium thiosulphate dissolved in water.    experiment 1   by using a measuring cylinder, 20  cm3 of distilled water was poured into a polystyrene cup.  use the thermometer diagram to record the temperature of the water in the table.    1  g of powdered sodium thiosulphate was added to the cup and the mixture stirred with a  thermometer. use the thermometer diagram to record the temperature of the solution.    experiment 2   experiment 1  was repeated using 2  g of powdered sodium thiosulphate. record the  temperature in the table.    experiments 3, 4 and 5   experiment 1  was repeated using 3  g, 4  g and 5  g of powdered sodium thiosulphate  respectively. record the temperatures in the table.   ",
            "6": "6  \uf6d9 ucles 2004 0620/06/o/n/04 for  examiner\u2019s  use   mass of sodium thiosulphate  / g temperature  / oc initial final 30 2520 302520201510 201510302520 252015 252015252015252015 15105 151050 12345      [5] ",
            "7": "7  \uf6d9 ucles 2004 0620/06/o/n/04  [turn over  for  examiner\u2019s  use  (a) plot the results of the experiments on the grid below. draw a straight line graph. clearly  label the graph. [5]    mass of thiosulphate added  / gfinal temperature  / oc 012345630 25 20 15 510 0      (b) (i) use your graph  to estimate the temperature of the reaction mixture if 3.5  g of  powdered sodium thiosulphate were added to 20  cm3 of water.      indicate clearly  on the graph how you obtained your answer.    [2]      (ii) from your graph work out the temperature of the reaction mixture if 6  g of  powdered sodium thiosulphate were added to 20  cm3 of water.      indicate clearly  how you used your graph.    [2]       (c) what type of chemical reaction occurs when sodium thiosulphate dissolves in water?    [1]    ",
            "8": "8  \uf6d9 ucles 2004 0620/06/o/n/04 for  examiner\u2019s  use  (d) explain how the temperature changes would differ in the experiments if 40  cm3 of water  were used.        [2]      (e) explain why the sodium thiosulphate was powdered before being used.      [2]      (f) predict what the temperature of the reaction mixture in experiment 5  would be after 1  hour. explain your answer.      [2]      (g) suggest one change you could make to the apparatus  used in the experiments to  obtain more accurate results.      [1]     ",
            "9": "9  \uf6d9 ucles 2004 0620/06/o/n/04  [turn over  for  examiner\u2019s  use 5 salt e, which is ammonium chloride was tested.     record all observations in the table.   tests observations  (a) describe the appearance of e    [2]     (b) using a spatula salt e was  placed in a hard glass test-tube. inside the top of the tube was suspended a piece of damp blue  litmus paper next to a piece of  damp red litmus paper. e was  heated gently until gas came out  of the tube.             red litmus went blue then  blue litmus went red           (c) e was dissolved in water to make  an aqueous solution.   the solution was divided into  three test-tubes   (i) to the first portion, was  added a few drops of dilute  nitric acid and about 1cm3 of  aqueous silver nitrate.   [2]   (ii) to the second portion of  solution e, was added     about 1  cm3 of lead nitrate  solution.   [2]     (iii) to the third portion of  solution e, was added about  1 cm3 of aqueous sodium  hydroxide. the mixture was  boiled gently and the gas given off was tested with indicator paper   [2]       (d) name the gas given off in test (c)(iii) .    [1]      (e) explain the observations in test (b).      [2]   ",
            "10": "10  \uf6d9 ucles 2004 0620/06/o/n/04 for  examiner\u2019s  use 6 describe a chemical test to distinguish between each of the following pairs of substances.  an example is given.      oxygen and carbon dioxide     test: glowing splint     result: re-lights in oxygen, no effect with carbon dioxide    (a) aqueous chlorine and aqueous sodium chloride  test   result with chlorine   result with sodium chloride   [2]     (b) aqueous iron( ii) chloride and aqueous iron( iii) chloride  test   result with iron( ii) chloride   result with iron( iii) chloride   [2]      (c) copper sulphate and copper carbonate  test   result with copper sulphate   result with copper carbonate   [2]  ",
            "11": "11  \uf6d9 ucles 2004 0620/06/o/n/04  for  examiner\u2019s  use 7 forged banknote      a fake banknote can be investigated by dissolving the ink off the paper.   you are provided with four different inks from four different criminals. describe an  experiment to show which one of these inks is the same as the ink from the banknote.    you can use a labelled diagram to help you answer the question.                                  [6]     ",
            "12": "12    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.     0620/06/o/n/04 blank page "
        }
    },
    "2005": {
        "0620_s05_qp_1.pdf": {
            "1": "     university of cambridge international examinations    international general certificate of secondary education        chemistry 0620/01       paper 1  multiple choice    may/june 2005        45 minutes     additional materials: multiple choice answer sheet      soft clean eraser      soft pencil (type b or hb is recommended)                          read these instructions first     write in soft pencil.    do not use staples, paper clips, highlighters, glue or correction fluid.   write your name, centre number and candidate number on the answer sheet in the spaces provided unless   this has been done for you.      there are forty  questions on this paper. answer all questions.   for each question there are four possible answers  a, b , c and d. choose the one you consider correct and   record your choice in soft pencil on the separate answer sheet.     read the instructions on the answer sheet very carefully.     each correct answer will score one mark. a mark will not be deducted for a wrong answer.   any rough working should be done in this booklet.   a copy of the periodic table is printed on page 16.  you may use a calculator.                                              this document consists of 15 printed pages and 1 blank page.  ib05 06_0620_01/2rp   \uf6d9 ucles 2005  [turn over  ",
            "2": "2    \u00a9 ucles 2005 0620/01/m/j/05 1 in which of the following are the particles arranged in a regular pattern?  a a gas  b a liquid  c a metal  d a solution      2 a student mixes 25  cm3 samples of dilute hydrochloric acid with different volumes of aqueous  sodium hydroxide. each time, the student measures the change in temperature to test if the  reaction is exothermic.    which piece of apparatus is not needed?    burette clock pipette thermometerab c d     3 in an experiment, a student needs to measure out 36.50  cm3 of a solution.    which piece of apparatus would measure this volume most accurately?  a beaker  b burette  c measuring cylinder  d pipette     ",
            "3": "3    \u00a9 ucles 2005 0620/01/m/j/05  [turn over  4 two isotopes of helium are he3 2and he4 2.    which two diagrams show the arrangement of particles in these two isotopes?     p n2 1ee ep n22ee p ne e ea np 21ee ep n2 2ee e eb p n21ee p n22ee c p 3 p 4ee ee dkey electron protonneutronnucleushe 3 242he      5 which row gives the outer electronic shell of fluorine and of neon?     9f 10ne  a 7 8  b 7 10  c 9 8  d 9 10    ",
            "4": "4    \u00a9 ucles 2005 0620/01/m/j/05 6 the electronic configuration of an ion is 2.8.8.    what could this ion be?     s2\u2013 ca2+  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    7 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     if the percentage of graphite is increased, the pencil slides across the paper more easily.    why is this?  a graphite conducts electricity.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.      8 which statement about gaseous hydrogen chloride and solid potassium chloride is correct?  a hydrogen chloride is covalent but potassium chloride is ionic.  b hydrogen chloride is ionic but potassium chloride is covalent. c they are both covalent compounds. d they are both ionic compounds.      9 which two elements form an alloy when they are heated together?  a chlorine and hydrogen  b chlorine and zinc c copper and hydrogen d copper and zinc     ",
            "5": "5    \u00a9 ucles 2005 0620/01/m/j/05  [turn over  10 for which compound is the formula correct?     compound formula  a ammonia nh 4  b carbon monoxide co 2  c iron( iii) oxide fe 3o2  d zinc hydroxide zn(oh) 2     11 at which stage in the manufacture of magnesium from sea-water can electrolysis be used?    sea watersolid magnesiumhydroxidesolidmagnesiumchloridemoltenmagnesiumchloride moltenmagnesiummetalstage a stage b stage c stage d       12 metallic and non-metallic elements can both be extracted by electrolysis.    which element is produced at the negative electrode (cathode)?  a bromine  b chlorine c hydrogen  d oxygen     13 which product is manufactured by electrolysis?  a aluminium  b copper( ii) sulphate  c sodium chloride  d steel     ",
            "6": "6    \u00a9 ucles 2005 0620/01/m/j/05 14 which diagrams show a process in which an exothermic change is taking place?    icesodium wate r water12 3 rocket     a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3     15 are hydrogen and uranium oxidised when used as a source of energy?     hydrogen uranium  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "7": "7    \u00a9 ucles 2005 0620/01/m/j/05  [turn over  16 a liquid x reacts with solid y to form a gas.    which two diagrams show suitable methods for investigating the speed of the reaction?    balancestopper x y3cotton wool x y1 stopper x y4balancecotton wool x y2     a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      17 in different experiments, 2  g of marble are added to 10  cm3 of hydrochloric acid.    in which tube is the reaction fastest?    hot hydrochloric acid marble chips powdered marbleab cold hydrochloric acid marble chips powdered marblecd      ",
            "8": "8    \u00a9 ucles 2005 0620/01/m/j/05 18 what is the colour of liquid bromine and of the aqueous bromide ion?     bromine bromide ion  a red-brown red-brown  b red-brown colourless  c yellow-green yellow-green  d yellow-green colourless     19 which property does hydrochloric acid have?  a it gives a pale blue precipitate with aqueous copper( ii) sulphate.  b it gives a white precipitate with aqueous barium nitrate.  c it releases ammonia from aqueous ammonium sulphate.  d it releases hydrogen with zinc powder.      20 hydrochloric acid is used to clean a metal surface by removing the oxide layer on the metal.    this is because hydrochloric acid has a \u2026.. x\u2026.. ph and the metal oxide is \u2026.. y\u2026..    what are x  and y?     x y  a high acidic  b high basic  c low acidic  d low basic    ",
            "9": "9    \u00a9 ucles 2005 0620/01/m/j/05  [turn over  21 the apparatus shown can be used to prepare aqueous copper( ii) sulphate.    aqueous ystirrer solid x aqueous copper( ii) sulphateexcess of solid xfilter paper heat    what are substances x and y?     substance x substance y  a copper iron( ii) sulphate  b copper( ii) chloride sulphuric acid  c copper( ii) oxide sulphuric acid  d sulphur copper( ii) chloride     22 in the experiment shown, the dilute sulphu ric acid is run into the flask of aqueous barium  hydroxide until the reaction is complete.    dilute sulphuricacid aqueousbariumhydroxide     which processes occur in this reaction?     neutralisation precipitation  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017 ",
            "10": "10    \u00a9 ucles 2005 0620/01/m/j/05 23 the chemical properties of an element depend mainly on the number of  a electrons in the innermost shell.  b electrons in the outermost shell.  c fully occupied shells of electrons.  d partly occupied shells of electrons.      24 an element x is in group iii of the periodic table.    which property of x can be predicted from this fact?  a the charge on an ion of x  b the colour of the ion of x  c the melting point of x  d the relative atomic mass, ar, of x     25 the table compares the properties of group i elements with those of transition elements.    which entry in the table is correct?     property group i elements transition elements  a catalytic activity low high  b density high low  c electrical conductivity low high  d melting point high low    26 caesium is near the bottom of group i of the periodic table.    what is the correct description of caesium?     state at room  temperature reaction with  cold water  a liquid reacts quickly  b liquid reacts slowly  c solid reacts quickly  d solid reacts slowly    ",
            "11": "11    \u00a9 ucles 2005 0620/01/m/j/05  [turn over  27 mild steel is an alloy of iron and carbon.    how does the carbon affect the properties of mild steel?  a the carbon makes the alloy a better conductor of electricity than iron.  b the carbon makes the alloy harder than the iron. c the carbon makes the alloy softer than the iron.  d the carbon stops the iron rusting.     28 which metal reacts quickly with cold water only when it is finely powdered?  a calcium  b copper  c sodium  d magnesium     29 which of the oxides cao, cuo and na 2o can be reduced by heating with carbon?  a cao only  b cuo only  c na2o only  d cao, cuo and na 2o     30 three stages in making steel from iron ore are listed.     x carbon dioxide reacts with carbon   y basic oxides and oxygen are added   z hematite is reduced    in which order do these stages occur?  a x \u2192 y \u2192 z  b x \u2192 z \u2192 y  c y \u2192 x \u2192 z  d z \u2192 y \u2192 x     ",
            "12": "12    \u00a9 ucles 2005 0620/01/m/j/05 31 the diagram shows ethanol burning inside a sealed jar.    air jar ethanol     the mass of one gas in the jar does not change.    which gas is this?  a carbon dioxide  b nitrogen c oxygen d water vapour     32 which methods prevent rusting of iron?     coating  with zinc painting washing with  distilled water  a \u0013 \u0013 \u0013  b \u0017 \u0013 \u0013  c \u0013 \u0013 \u0017  d \u0013 \u0017 \u0017     33 which processes do not use oxygen?     1 burning natural gas   2 heating a room with an electric fire   3 welding apparatus    a 1 only b 2 only c 3 only d 1, 2 and 3     ",
            "13": "13    \u00a9 ucles 2005 0620/01/m/j/05  [turn over  34 the presence of nitrates in soil can be shown by warming the soil with aqueous sodium  hydroxide and aluminium foil.    which gas is given off?  a ammonia  b carbon dioxide  c nitrogen  d nitrogen dioxide     35 dolomite is a rock that contains magnesium carbonate.    a piece of dolomite is heated strongly in air.    which word equation correctly describes the reaction that takes place?  a magnesium carbonate + water \u2192 magnesium hydroxide + carbon dioxide  b magnesium carbonate + oxygen \u2192 magnesium oxide + carbon dioxide + water  c magnesium carbonate + oxygen \u2192 magnesium oxide + water  d magnesium carbonate \u2192 magnesium oxide + carbon dioxide     36 which two compounds have molecules in which there is a double bond?  a ethane and ethanoic acid  b ethane and ethanol  c ethene and ethanoic acid  d ethene and ethanol    37 which substance is found in crude oil?  a bitumen  b ethanol c ethanoic acid  d poly(ethene)     ",
            "14": "14    \u00a9 ucles 2005 0620/01/m/j/05 38 which statement about a family of organic compounds describes an homologous series?    all compounds in the family have the same  a functional group.  b physical properties. c relative molecular mass. d structural formula.     39 which column describes ethane and which column describes ethene?    hydrocarbon    1 2 3 4  state at room temperature gas gas liquid liquid  reaction with oxygen burns burns burns burns  reaction with  aqueous bromine no reaction decolourises  bromine no reaction decolourises  bromine    a 1 (ethane) and 2  (ethene)  b 1 (ethane) and 3  (ethene)  c 2 (ethene) and 3  (ethane)  d 3 (ethane) and 4  (ethene)     40 which of the products c 12h24 and h 2 could be formed by cracking dodecane, c 12h26?     c12h24 h 2  a \u0017 \u0017  b \u0017 \u0013  c \u0013 \u0017  d \u0013 \u0013     ",
            "15": "15      every reasonable effort has been made to trace all copyright holders where the publishers (i.e. ucles) are aware that third-par ty material has been  reproduced. the publishers would be pleased to hear from any one whose rights they have unwittingly infringed.     0620/01/m/j/05   blank page",
            "16": "16      university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.   0620/01/m/j/05  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89                9 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s05_qp_2.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry 0620/02        paper 2 (core)    may/june 2005        1 hour 15 minutes     candidates answer on the question paper.     no additional materials required.                                read these instructions first     write your centre number, candidate number and name on all the work you hand in.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part question.   a copy of the periodic table is printed on page 16.                                 for examiner\u2019s use   1    2    3    4    5    6    total     this document consists of 16 printed pages.  ib05 06_0620_02/4rp   \uf6d9 ucles  2005  [turn over    if you have been given a label, look at the  details. if any details are incorrect or missing, please fill in your correct details in  the space given at the top of this page.   stick your personal label here, if provided.   ",
            "2": "2  \u00a9 ucles 2005 0620/02/m/j/05 for  examiner's  use 1 the structures of some substances are shown below.      br hch c hh ch hh ch hh hi\u2013na+i\u2013na+na+ i\u2013i\u2013i\u2013na+na+ i\u2013na+i\u2013na+na+ i\u2013i\u2013i\u2013na+na+ cc c cc c cccc cc ccc ccc c ccccc c ccc cccccccc ccc cab dec           (a) answer these questions using the letters a, b, c, d or e.  (i) which structure is methane?  [1]  (ii) which two structures are giant structures?  and  [1]  (iii) which two structures are hydrocarbons?  and  [1]  (iv) which structure contains ions?  [1]  (v) which two structures have very high melting points?    and  [1]     ",
            "3": "3  \u00a9 ucles 2005 0620/02/m/j/05 [turn over  for  examiner's  use  (b) structure e is a form of carbon.     (i) what is the name of this structure?   put a ring around the correct answer.  carbide graphite lead poly(hexene) [1]     (ii) name another form of carbon.   [1]     (c) write the simplest formula for substance b.   [1]       (d) is substance d an element or a compound?    explain your answer.     [1]      ",
            "4": "4  \u00a9 ucles 2005 0620/02/m/j/05 for  examiner's  use 2 a student collected some water from a polluted river.   the water contained soluble solids and insoluble clay and had a ph of 5.    (a) how can the student separate the clay from the rest of the river water?   [1]     (b) the student uses litmus paper to show that the river water is acidic.    what will be the result of this test?   [1]     (c) the student then boiled the river water to obtain the soluble solids.    the diagram shows how she heated the water.    steel can copper gauze iron tripodboiling water natural gassteam        which of the substances named in the diagram is  (i) an alloy,  [1]  (ii) a compound which is liquid at room temperature,  [1]  (iii) an element,  [1]  (iv) a fuel?  [1]      (d) name the main substance in natural gas.   [1]      (e) what is the normal temperature of boiling water?   [1]   ",
            "5": "5  \u00a9 ucles 2005 0620/02/m/j/05 [turn over  for  examiner's  use  (f) after the student boiled off the water, she analysed the white powder on the inside of  the steel can.   the table shows her results.    name of ion formula of ion mass of ion present  /milligrams  calcium ca2+ 16  carbonate co 32\u2013 35  chloride cl \u2013 8  nitrate no 3\u2013 4  sodium na+ 8  sulphate so 42\u2013 6       (i) which positive ion had the greatest concentration in the sample of river water?   [1]      (ii) complete the following equation to show how a sodium ion is formed from a  sodium atom.  na na+   +    [1]       (g) instead of using natural gas, the student could have used butane to heat the water.    the formula of butane is c 4h10.     (i) what products are formed when butane burns in excess air?   [1]     (ii) name the poisonous gas formed when butane undergoes incomplete combustion.   [1]    ",
            "6": "6  \u00a9 ucles 2005 0620/02/m/j/05 for  examiner's  use 3 ammonia is a gas which forms an alkaline solution when dissolved in water.     (a) complete the diagram below to show the arrangement of the molecules in ammonia  gas.      o represents a single molecule of ammonia.    o   [2]     (b) which one of the following values is most likely to represent the ph of a dilute solution  of ammonia?   put a ring around the correct answer.  ph2 ph6 ph7 ph9 [1]      (c) the structure of the ammonia molecule is shown below.    n hh h       (i) write the simplest formula for ammonia.       [1]      (ii) describe the type of bonding in a molecule of ammonia.   [1]      (iii) ammonia is a gas at room temperature.     suggest why ammonia has a low boiling point.   [1]   ",
            "7": "7  \u00a9 ucles 2005 0620/02/m/j/05 [turn over  for  examiner's  use  (d) many fertilisers contain ammonium sulphate.     (i) which acid must be added to ammonia solution to make ammonium sulphate?   put a ring around the correct answer.  hc l hno 3 h 3po 4 h 2so 4 [1]    (ii) fill in the missing words in the following sentence using two of the words from the  list.  air hydrogen nitrogen soil sodium water     fertilisers are needed in agriculture to replace the  ,  phosphorus and other elements which are removed from the   when crops are grown. [2]        (e) a solution of ammonia has a strong smell.   a beaker of ammonia solution is put in the corner of a room which is free of draughts.    beaker of ammoniasolution girl (standingby window)      at first, the girl by the closed window cannot smell the ammonia.  after 30 seconds she smells the ammonia.   use the kinetic particle theory to explain these facts.         [3]   ",
            "8": "8  \u00a9 ucles 2005 0620/02/m/j/05 for  examiner's  use  (f) the diagram shows the apparatus used for oxidising ammonia in the laboratory.    airtongs platinum wire ammonia solution       first, nitrogen( ii) oxide, no, is produced. this then reacts with oxygen to form  nitrogen( iv) oxide, no 2.     (i) where does the oxygen come from in this reaction?   [1]     (ii) balance the equation for the reaction of nitrogen( ii) oxide with oxygen.    2no   +   o 2 .no 2   [1]     (iii) what is the meaning of the symbol  ?   [1]       (iv) the platinum wire acts as a catalyst in the reaction. as the reaction takes place, the  wire begins to glow red hot.   what does this show about the reaction?    [1]     ",
            "9": "9  \u00a9 ucles 2005 0620/02/m/j/05 [turn over  for  examiner's  use 4 poly(ethene) is a plastic which is made by polymerizing ethene, c 2h4.     (a) which one of the following best describes the ethene molecules in this reaction?   put a ring around the correct answer.   alcohols alkanes monomers polymers products [1]     (b) the structure of ethane is shown below.    c hh ch h hh      explain, by referring to its bonding, why ethane cannot be polymerized.   [1]      (c) draw the structure of ethene, showing all atoms and bonds.            [1]    (d) ethene is obtained by cracking alkanes.    (i) explain the meaning of the term cracking .     [1]      (ii) what condition is needed to crack alkanes?   [1]     (iii) complete the equation for cracking decane, c 10h22.    c10h22 c2h4   +   . [1]    ",
            "10": "10  \u00a9 ucles 2005 0620/02/m/j/05 for  examiner's  use  (e) some oil companies \u2018crack\u2019 the ethane produced when petroleum is distilled.     (i) complete the equation for this reaction.  c2h6 c2h4   +   . [1]       (ii) describe the process of fractional distillation which is used to separate the different  fractions in petroleum.          [2]       (iii) state a use for the following petroleum fractions.  petrol fraction   lubricating fraction  [2]     ",
            "11": "11  \u00a9 ucles 2005 0620/02/m/j/05 [turn over  for  examiner's  use 5 the halogens are a group of diatomic non-metals showing a trend in colour, state and  reactivity.    (a) in this description, what is the meaning of  (i) diatomic,  [1]  (ii) state?  [1]     (b) the table gives some information about some of the halogens.    element melting point  /  oc boiling point  / oc colour state at room  temperature  chlorine -101 -35 green   bromine -7 +59    iodine +114  grey-black        (i) complete the last column in the table to show the state of each of the halogens at room temperature. [2]       (ii) state the colour of bromine.   [1]      (iii) suggest a value for the boiling point of iodine.   [1]        (c) complete the word equation for the reaction of chlorine with potassium iodide.  chlorine + potassium iodide   +     [2]       ",
            "12": "12  \u00a9 ucles 2005 0620/02/m/j/05 for  examiner's  use  (d) (i)  draw a diagram to show the electronic structure of a chlorine molecule.   show only the outer electrons.                 [2]     (ii) state a use of chlorine.   [1]      (e) the structures of some substances containing halogens are shown below.    cl h br brbr ff fcl \u2013na+ na+cl \u2013na+ cl \u2013na+cl \u2013na+cl \u2013cl \u2013na+ ab c d       (i) which one of these structures, a, b, c or d, shows an element?   [1]     (ii) which one of these structures forms hydrochloric acid when dissolved in water?   [1]     (iii) complete the following sentence.  structure b conducts electricity when it is molten because    [2]     ",
            "13": "13  \u00a9 ucles 2005 0620/02/m/j/05 [turn over  for  examiner's  use  (f) astatine, at, is below iodine in group vii of the periodic table.     (i) in which period of the periodic table is astatine?    [1]       (ii) how many protons does astatine have in its nucleus?   [1]      (iii) astatine has many isotopes.   what do you understand by the term isotopes ?     [1]       (iv) the most common isotope of astatine has a nucleon number (mass number) of 210.   calculate the number of neutrons in this isotope of astatine.   [1]  ",
            "14": "14  \u00a9 ucles 2005 0620/02/m/j/05 for  examiner's  use 6 the electroplating of iron with chromium involves four stages.   1. the iron object is cleaned with sulphuric acid, then washed with water.   2. the iron is plated with copper.  3. it is then plated with nickel to prevent corrosion.  4. it is then plated with chromium.     (a) the equation for stage 1 is    fe   +   h 2so 4 feso 4   +   h 2      (i) write a word equation for this reaction.         [2]      (ii) describe a test for the gas given off in this reaction.  test   result  [2]      (b) the diagram shows how iron is electroplated with copper.    +_ rod of pure copperiron object copper( ii) sulphate solution      (i) choose a word from the list below which describes the iron object.   put a ring around the correct answer.  anion anode cathode cation [1]      (ii) what is the purpose of the copper( ii) sulphate solution?   [1]     ",
            "15": "15      every reasonable effort has been made to trace all copyright holders where the publishers (i.e. ucles) are aware that third-par ty material has been  reproduced. the publishers would be pleased to hear from any one whose rights they have unwittingly infringed.    university of cambridge international examinations is part of t he university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.    \u00a9 ucles 2005 0620/02/m/j/05  for  examiner's  use  (iii) describe what happens during the electroplating to  the iron object,   the rod of pure copper.  [2]      (iv) describe a test for copper( ii) ions.  test   result    [3]       (c) suggest why chromium is used to electroplate articles.   [1]      (d) the information below shows the reactivity of chromium, copper and iron with warm  hydrochloric acid.     chromium \u2013 few bubbles of gas produced every second   copper \u2013 no bubbles of gas produced   iron \u2013 many bubbles of gas produced every second     put these three metals in order of their reactivity with hydrochloric acid.   most reactive \u2192      least reactive \u2192    [1]   ",
            "16": "16  \u00a9 ucles 2005 0620/02/m/j/05    group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89                9 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s05_qp_3.pdf": {
            "1": "this document consists of 14 printed pages and 2 blank pages.  ib05 06_0620_03/3rp   \uf6d9 ucles  2005        [turn over   university of cambridge international examinations   international general certificate of secondary education      chemistry       paper 3 (extended) 0620/03        may/june 2005       1 hour 15 minutes   candidates answer on the question paper.   no additional materials required.                                 read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen.  you may use a pencil for any diagrams, graphs or rough working.  write in the boxes provided on the question paper  do not  write in the barcode.  do not  write in the grey areas between the pages.  do not use staples, paper clips, highlighters, glue or correction fluid.  you may use a calculator.    answer all questions.  the number of marks is given in brackets [  ] at the end of each question   or part questions.  a copy of the periodic table is printed on page 16. candidate name centrenumber candidatenumbe r*062003* for examiner\u2019s use 1 234 5 6 total",
            "2": "2  \u00a9 ucles 2005 0620/03/m/j/05 for  examiner's  use1 three of the halogens in group vii are:  chlorine  bromine  iodine       (a) (i)  how does their colour change down the group?   [1]     (ii) how does their physical state (solid, liquid or gas) change down the group?   [1]     (iii) predict the colour and physical state of fluorine.  colour   physical state  [2]      (b) describe how you could distinguish between aqueous potassium bromide and aqueous  potassium iodide.  test   result with bromide   result with iodide  [3]       (c) 0.015 moles of iodine react with 0.045 moles of chlorine to form 0.030 moles of a single  product. complete the equation.  i2 +  cl2   [2]       (d) traces of chlorine can be separated from bromine vapour by diffusion.    which gas would diffuse the faster and why?     [2]   ",
            "3": "3  \u00a9 ucles 2005 0620/03/m/j/05 [turn over  for  examiner's  use 2 the following apparatus was used to measure the rate of the reaction between zinc and  iodine.     100  cm3 of aqueous iodine, 0.1  mol  / dm3 at 25 oc mixture stirred by magnetic stirrerthin plate of zincto balance       the mass of the zinc plate was measured every minute until the reaction was complete.    (a) write an ionic equation for the redox reaction that occurred between zinc atoms and  iodine molecules.   [2]      (b) describe how you could show by adding aqueous sodium hydroxide and aqueous  ammonia that a solution contained zinc ions.  result with sodium  hydroxide   excess sodium hydroxide   result with aqueous ammonia   excess aqueous ammonia  [3]     ",
            "4": "4  \u00a9 ucles 2005 0620/03/m/j/05 for  examiner's  use (c) from the results of this experiment two graphs were plotted.      time timemass of plateloss ofmassgraph 1 graph 2        (i) which reagent iodine or zinc was in excess? give a reason for your choice.   [1]     (ii) describe how the shape of graph 1 would change if 100cm3 of 0.05 mol/dm3 iodine  had been used.     [2]     (iii) on graph 2, sketch the shape if the re action had been carried out using 100 cm3 of  0.1 mol/dm3 iodine at 35  \u00b0c instead of at 25  \u00b0c. [2]   ",
            "5": "5  \u00a9 ucles 2005 0620/03/m/j/05 [turn over  for  examiner's  use 3 a south korean chemist has discovered a cure for smelly socks. small particles of silver are  attached to a polymer, poly(propene), and this is woven into the socks.    (a) (i)  give the structural formula of the monomer.                 [1]     (ii) draw the structural formula of the polymer.                [2]     (iii) suggest which one, monomer or polymer, will react with aqueous bromine and why?     [2]       (b) to show that the polymer contains silver the following test was carried out.      the polymer fibres were chopped into small pieces and warmed with nitric acid. the  silver atoms were oxidised to silver( i) ions. the mixture was filtered. aqueous sodium  chloride was added to the filtrate and a white precipitate formed.    (i) why was the mixture filtered?   [1]    (ii) explain why the change of silver atoms to silver ions is oxidation.   [1]     (iii) give the name of the white precipitate.   [1]   ",
            "6": "6  \u00a9 ucles 2005 0620/03/m/j/05 for  examiner's  use (c) the unpleasant smell is caused by carboxylic acids. bacteria cause the fats on the skin  to be hydrolysed to these acids. silver kills the bacteria and prevents the hydrolysis of  the fats.    (i) fats are esters. give the name and structural formula of an ester.  name  [1]  structural formula                 [1]     (ii) complete the word equation.  ester + water   carboxylic acid +   [1]       (d) propanoic acid is a weak acid.     (i) the following equation represents its reaction with ammonia.     ch 3   ch 2   cooh   +   nh 3 ch 3   ch 2   coo\u2013   +   nh 4+      explain why propanoic acid behaves as an acid and ammonia as a base.     [3]     (ii) explain the expression weak acid.    [1]   ",
            "7": "7  \u00a9 ucles 2005 0620/03/m/j/05 [turn over  for  examiner's  use 4 the carlsbad caverns in new mexico are very large underground caves. although the walls  of these caves are coated with gypsum (hydrated calcium sulphate), the caves have been formed in limestone.    (a) it is believed that the caves were formed by sulphuric acid reacting with the limestone.    (i) complete the word equation.  calcium + sulphuric   calcium +  +    carbonate acid  sulphate  [1]   (ii) describe how you could test the water entering the cave to show that it contained  sulphate ions.  test   result  [2]     (iii) how could you show that the water entering the cave has a high concentration of  hydrogen ions?   [1]       (b) hydrogen sulphide gas which was escaping from nearby petroleum deposits was being  oxidised to sulphuric acid.     (i) complete the equation for this reaction forming sulphuric acid.  h2s +  o2     [2]     (ii) explain why all the hydrogen sulphide should be removed from the petroleum  before it is used as a fuel.      [1]  ",
            "8": "8  \u00a9 ucles 2005 0620/03/m/j/05 for  examiner's  use (iii) draw a diagram to show the arrangement of the valency electrons in one molecule  of the covalent compound hydrogen sulphide.   use o to represent an electron from a sulphur atom.   use x to represent an electron from a hydrogen atom.                     [2]     (c) sulphuric acid is manufactured by the contact process. sulphur dioxide is oxidised to  sulphur trioxide by oxygen.      2so 2   +   o 2 2so 3      (i) name the catalyst used in this reaction.   [1]    (ii) what temperature is used for this reaction?   [1]   (iii) describe how sulphur trioxide is changed into sulphuric acid.      [2]      (d) gypsum is hydrated calcium sulphate, caso 4.xh 2o. it contains 20.9% water by mass.  calculate x.  mr: caso 4, 136; h 2o, 18.  79.1  g of caso 4 =  moles  20.9 g of h 2o =  moles  x =     [3]  ",
            "9": "9  \u00a9 ucles 2005 0620/03/m/j/05 [turn over  for  examiner's  use 5 enzymes are biological catalysts. they are used both in research laboratories and in  industry.    (a) enzymes called proteases can hydrolyse proteins to amino acids. the amino acids can  be separated and identified by chromatography. the diagram below shows a typical  chromatogram.      sample asample bsolvent front initial level of solventsamples are placed on this line        (i) the rf value of a sample =  distance travelled by sample    distance travelled by solvent front    some r f values for amino acids are:  glutamic acid = 0.4 glycine = 0.5 alanine = 0.7 leucine = 0.9    identify the two amino acids on the chromatogram.  a is   b is   [2]     (ii) explain why the chromatogram must be exposed to a locating agent before rf  values can be measured.   [1]  ",
            "10": "10  \u00a9 ucles 2005 0620/03/m/j/05 for  examiner's  use (iii) measuring rf values is one way of identifying amino acids on a chromatogram.  suggest another.   [1]    (iv) the synthetic polymer, nylon, has the same linkage as proteins. draw the structural  formula of nylon.                  [3]     (b) enzymes called carbohydrases can hydrolyse complex carbohydrates to simple sugars  which can be represented as   oh ho . draw the structure of a complex  carbohydrate.                     [2]    ",
            "11": "11  \u00a9 ucles 2005 0620/03/m/j/05 [turn over  for  examiner's  use  (c) fermentation can be carried out in the ap paratus drawn below. after a few days the  reaction stops. it has produced a 12% aqueous solution of ethanol.      aqueous glucose and yeastallows carbondioxide to escape but prevents air entering        (i) complete the equation.  c6h12o6   +     glucose  ethanol  carbon dioxide  [2]   (ii) zymase catalyses the anaerobic respiration of glucose. define the term respiration .     [2]    (iii) suggest a reason why the reaction stops after a few days.   [1]    (iv) why is it essential that there is no oxygen in the flask?   [1]   (v) what technique is used to concentrate the aqueous ethanol?   [1]  ",
            "12": "12  \u00a9 ucles 2005 0620/03/m/j/05 for  examiner's  use6 the position of aluminium in the reactivity series of metals is shown below.    magnesium  aluminium  zinc  copper       (a) aluminium is extracted by the electrolysis of its molten oxide.     waste gases carbon cathode (\u2013)carbon anode (+) mixture of aluminium  oxide and cryolite aluminium900 oc       (i) name the main ore of aluminium.   [1]     (ii) why does the molten electrolyte contain cryolite?   [1]     (iii) oxygen is produced at the positive electrode (anode). name another gas which is  given off at this electrode.   [1]      (b) aluminium reacts very slowly with aqueous copper( ii) sulphate.    2al(s)   +   3cuso 4(aq) al2(so 4)3(aq)   +   3cu(s)     (i) which of the two metals has the greater tendency to form ions?   [1]     (ii) describe what you would see when this reaction occurs.   [1]     (iii) explain why aluminium reacts so slowly.   [1]  ",
            "13": "13  \u00a9 ucles 2005 0620/03/m/j/05 for  examiner's  use  (c) complete the following table by writing \u201creaction\u201d or \u201cno reaction\u201d in the spaces  provided.    oxide type of oxide reaction with acid reaction with alkali    magnesium basic           aluminium amphoteric          [2]       (d) predict the equations for the decomposition of the following aluminium compounds.  (i)  al(oh) 3  +   [2]    (ii) aluminium nitrate   +  +          [2]   ",
            "14": "14   0620/03/m/j/05 blank page  ",
            "15": "15    every reasonable effort has been made to t race all copyright holders where the publishers  (i.e. ucles) are aware that third-par ty material  has been reproduced. the publishers would be pleased to hear f rom anyone whose rights they have unwittingly infringed.    university of cambridge international examinations is part of t he university of cambridge local examinations syndicate (ucles),  which is  itself a department of the university of cambridge.    0620/03/m/j/05 blank page  ",
            "16": "16  \u00a9 ucles 2005 0620/03/m/j/05    group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89                9 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s05_qp_5.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry 0620/05        paper 5  practical test    may/june 2005        1 hour 15 minutes     candidates answer on the question paper.     additional materials:  as listed in instructions to supervisors                                read these instructions first     write your name, centre number and candidate number in the spaces at the top of this page.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part question.   practical notes are provided on page 8.                                               for examiner\u2019s use   1    2    total     this document consists of 6 printed pages and 2 blank pages.  ib05 06_0620_05/4rp   \uf6d9 ucles  2005  [turn over    if you have been given a label, look at the  details. if any details are incorrect or missing, please fill in your correct details in  the space given at the top of this page.   stick your personal label here, if provided.   ",
            "2": "2  \u00a9 ucles 2005 0620/05/m/j/05 for  examiner's  use  1 you are going to investigate a mixture of calcium hydroxide and water.     read all the instructions below carefully before  starting the experiment.     instructions     shake the mixture of calcium hydroxide and water provided in the bottle.     after one minute of shaking, filter the mixture into a beaker.   start experiment 1 when enough solution has been collected. continue to filter the mixture.      experiment 1     by using a measuring cylinder, measure 25  cm3 of the solution (filtrate) into the conical flask  provided.     carry out the titration as follows.    fill the burette to the 0.0  cm3 mark with the solution m  of hydrochloric acid.     add 3 or 4 drops of phenolphthalein to the flask.    add solution m slowly to the flask until the colour just disappears. record the burette  readings in the table. pour the solution away and rinse the conical flask.      experiment 2    empty the contents of the burette down the sink.   rinse the burette with the solution n of hydrochloric acid.    repeat experiment 1 using the solution n of hydrochloric acid.    record your results in the table.   normally you would be required to carry out repeat titrations.  however, owing to time considerations you are only required to carry out one titration for each experiment    table of results    burette readings/  cm3 experiment 1 experiment 2  final reading    initial reading    difference     [6]    (a) describe the appearance of the mixture of calcium hydroxide and water.   [1]   ",
            "3": "3  \u00a9 ucles 2005 0620/05/m/j/05 [turn over  for  examiner's  use   (b) how did the colour of the solution in the flask change?  from  to  [2]       (c) what type of chemical reaction occurs when hydrochloric acid reacts with calcium  hydroxide?   [1]     (d) (i)  in which experiment was the greater volume of hydrochloric acid used?   [1]     (ii) compare the volumes of acid used in experiments 1 and 2.     [2]     (iii) suggest an explanation for the difference in volumes.     [2]      (e) predict the volume of hydrochloric acid m which would be needed to react completely if  experiment 1 was repeated with 50  cm3 of calcium hydroxide solution and explain your  answer.  volume of solution   explanation    [3]      (f) suggest one change you could make to the apparatus  used in the experiments to  obtain more accurate results.     [1]     (g) from the list below choose the correct word to complete the sentence.     not slightly very     calcium hydroxide is   soluble in water. [1]   ",
            "4": "4  \u00a9 ucles 2005 0620/05/m/j/05 for  examiner's  use  2 you are provided with liquid a.     carry out the following tests on a, recording all of your observations in the table.  do not  write any conclusions in the table.    tests observations   (a) describe the appearance and smell of a.     [2]        colour     ph   [2]   (b) test the ph of the solution  using indicator paper.          (c) divide the liquid into five test- tubes.   (i) to the first portion, add the piece of magnesium  ribbon provided. note any observations and test the  gas.  [3]              [2]   (ii) to the second portion of  liquid a, add slowly a  spatula measure of anhydrous sodium  carbonate. test the gas  with limewater.                        [2]   (iii) to the third portion of  liquid a, add a spatula  measure of solid b. boil  gently  for 2 minutes.     note any observations.      by using a teat pipette  transfer the solution to  another test tube. to this  solution add excess  aqueous ammonia.      ",
            "5": "5  \u00a9 ucles 2005 0620/05/m/j/05  for  examiner's  use  tests observations                  [2]   (iv) to the fourth portion of  the liquid add about 1  cm3  of ethanol. ask your  supervisor to add a few drops of concentrated  sulphuric acid to the  mixture.     boil the mixture gently.  pour the mixture into a beaker half full of water. note your observations.                  [1]   (v) to the fifth portion of  liquid a add a few drops  of dilute sulphuric acid  and about 1  cm3 of  potassium dichromate  solution.     boil gently  and note any  observation.       (d) (i)  name the gas given off in test (c)(i) .   [1]     (ii) name the gas given off in test (c)(ii) .   [1]      (e) use your observations in test (c)(iii) to say what ion is present in solid b.     [2]      (f) what conclusions can you draw about liquid a?     [2]  ",
            "6": "6   0620/05/m/j/05 blank page    ",
            "7": "7   0620/05/m/j/05  blank page    ",
            "8": "8    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.  \u00a9 ucles 2005 0620/05/m/j/05 notes for use in qualitative analysis     test for anions     anion test test result  carbonate (co-2 3) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then  aqueous lead( ii) nitrate yellow ppt.  nitrate (no\u2212 3)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulphate (so-2 4)  [in solution] acidify with dilute nitric acid, then  aqueous barium nitrate white ppt.    test for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh+ 4) ammonia produced on warming -  calcium (ca2+) white., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution    test for gases     gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_s05_qp_6.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry  0620/06         paper 6  alternative to practical    may/june 2005        1 hour    candidates answer on the question paper.     no additional materials required.                           read these instructions first     write your name, centre number and candidate number at the top of this page.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part question.                         for examiner\u2019s use     1    2   3   4   5    6    7    8    total       this document consists of 11 printed pages and 1 blank page.  ib05 06_0620_06/4rp   \uf6d9 ucles 2005  [turn over    if you have been given a label, look at the details. if any details are incorrect or  missing, please fill in your correct details in  the space given at the top of this page.   stick your personal label here, if provided.  ",
            "2": "2    \u00a9 ucles 2005 0620/06/m/j/05 for  examiner's  use 1 a small piece of limestone was heated strongly and left to cool. a few drops of cold water  were added. the solid expanded and gave off steam.     limestone water lime (calciumoxide)        (a) complete the empty boxes to identify the pieces of apparatus labelled. [3]     (b) what type of chemical reaction takes place when water is added?   [1]    ",
            "3": "3    \u00a9 ucles 2005  0620/06/m/j/05  [turn over  for  examiner's  use 2 the diagram shows the apparatus used to find out the effect of an electric current on a  concentrated aqueous solution of sodium chloride.          (a) on the diagram label the electrodes [1]     (b) give three observations when the circuit is switched on.  1   2   3  [3]      (c) (i) name the product at the positive electrode (anode).   [1]    (ii) state a test for this product and the result of the test.  test   result  [2]     ",
            "4": "4    \u00a9 ucles 2005 0620/06/m/j/05 for  examiner's  use 3 in a set of experiments zinc was reacted with sulphuric acid to form hydrogen. the  apparatus below was used.     gas syringe sulphuric acid10 20 30 40 50 60 70 80 excess zinc     the same mass of zinc was used each time. the volume of acid used was different each  time. use the syringe diagrams to record the volume of hydrogen produced each time in the table.    table of results    volume of sulphuric  acid/cm 3 syringe diagram volume of  hydrogen/cm3  0 70 10 20 30 40 50 60 80    5 70 10 20 30 40 50 60 80    15 70 10 20 30 40 50 60 80    20 70 10 20 30 40 50 60 80    25 70 10 20 30 40 50 60 80    30 70 10 20 30 40 50 60 80    35 70 10 20 30 40 50 60 80    40 70 10 20 30 40 50 60 80       [4]   ",
            "5": "5    \u00a9 ucles 2005  0620/06/m/j/05  [turn over  for  examiner's  use  (a) plot the results on the grid below. draw a smooth line graph.      80 70605040302010 51 0 1 5 2 0 volume of acid  / cm325 30 35 400volume of hydrogen  / cm3    [4]     (b) use the graph to find the volume of sulphuric acid that will produce 33  cm3 of gas.   [1]     (c) what volume of gas is produced if 10 cm 3 of sulphuric acid is used?   [1]    ",
            "6": "6    \u00a9 ucles 2005 0620/06/m/j/05 for  examiner's  use 4 a student investigated an aqueous solution of calcium hydroxide and water.     two experiments were carried out.   experiment 1     by using a measuring cylinder 25  cm3 of the aqueous solution of calcium hydroxide was  placed in a flask. phenolphthalein indicator was added to the flask. a burette was filled to the 0.0  cm3 mark with solution m of hydrochloric acid.    solution m was added slowly to the flask until the colour just disappeared. use the burette  diagram to record the volume in the table and complete the column.      9 1011       experiment 2     experiment 1 was repeated using a different solution, n, of hydrochloric acid.    use the burette diagrams to record the volumes in the table and complete the table.    14 1516353637 initial final    ",
            "7": "7    \u00a9 ucles 2005  0620/06/m/j/05  [turn over  for  examiner's  use table of results       burette readings/cm3 experiment 1 experiment 2  final reading    initial reading 0.0   difference     [4]    (a) what type of chemical reaction occurs when hydrochloric acid reacts with calcium hydroxide?   [1]     (b) (i) in which experiment was the greater volume of hydrochloric acid used?   [1]    (ii) compare the volumes of acid used in experiments 1 and 2.     [2]     (iii) suggest an explanation for the difference in volumes.     [2]       (c) predict the volume of hydrochloric acid m that would be needed to react completely if  experiment 1 was repeated with 50  cm3 of calcium hydroxide solution?  volume of solution   explanation    [3]      (d) suggest one change you could make to the apparatus  used in the experiments to  obtain more accurate results.     [1]     ",
            "8": "8    \u00a9 ucles 2005 0620/06/m/j/05 for  examiner's  use 5 a sample of a solution of acid a was analysed.     the tests on a, and some of the observations are in the following table.    complete the observations in the table.      tests observations   (a) the ph of the solution was  tested using indicator paper colour orange  ph 4       (b) the solution was divided into  three test-tubes    (i) to the first portion was  added a piece of  magnesium ribbon. the  gas was tested with a  lighted splint.  [2]        (ii) to the second portion of  a was added sodium  carbonate. the gas was  tested  with lim ewater.   [2]   (iii) to the third portion of  liquid a was added a  spatula measure of solid  b. the mixture was boiled  gently. by using a teat  pipette the solution was transferred to another test tube. excess aqueous  ammonia was added.          green solution formed      dark blue solution formed            (c) what does test (a) tell you about the type of acid in solution a?   [1]      (d) (i) name the gas given off in test (b)(i) .   [1]    (ii) name the gas given off in test (b)(ii) .   [1]     ",
            "9": "9    \u00a9 ucles 2005  0620/06/m/j/05  [turn over  for  examiner's  use  (e) explain the observations in test (b)(iii) .     [2]      6 the label below is from a bottle of concentrated lemon drink.      concentrated lemon drink   ingredients:  water, sugar, citric acid, preservatives, potassium sorbate  (artificial sweetener). yellow colourings e102 and e104.      (a) what is meant by the term concentrated ?   [1]       (b) predict the ph of the lemon drink.   [1]      (c) describe an experiment to show that two different yellow colourings are present in the  drink.                                      [4] ",
            "10": "10    \u00a9 ucles 2005 0620/06/m/j/05 for  examiner's  use 7 samples of concrete were placed in solutions of different ph. the graph shows the  percentage corrosion of the samples.     70 605040302010 2 13 4 ph567% corrosion       (a) draw a smooth line graph on the grid [1]      (b) which point on the grid appears to be inaccurate? explain your reason for identifying  this point.     [2]       (c) what happens to the percentage corrosion as the ph changes from 1 to 7?   [1]   ",
            "11": "11    \u00a9 ucles 2005 0620/06/m/j/05  for  examiner's  use 8 an aqueous solution of hydrogen peroxide decomposes very slowly to form oxygen. the  speed of decomposition can be increased by using a catalyst. two possible catalysts are  the solids copper( ii) oxide and chromium( iii) oxide.     plan an investigation to find out which of these two oxides is the better catalyst for this  decomposition.    the space below can be used for a diagram.                                 [6]     ",
            "12": "12      permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.     0620/06/m/j/05 blank page "
        },
        "0620_w05_qp_1.pdf": {
            "1": "     university of cambridge international examinations    international general certificate of secondary education        chemistry 0620/01       paper 1  multiple choice    october/november 2005        45 minutes     additional materials: multiple choice answer sheet      soft clean eraser      soft pencil (type b or hb is recommended)                          read these instructions first     write in soft pencil.    do not use staples, paper clips, highlighters, glue or correction fluid.   write your name, centre number and candidate number on the answer sheet in the spaces provided unless   this has been done for you.      there are forty  questions on this paper. answer all questions.   for each question there are four possible answers  a, b , c and d. choose the one you consider correct and   record your choice in soft pencil on the separate answer sheet.     read the instructions on the answer sheet very carefully.     each correct answer will score one mark. a mark will not be deducted for a wrong answer.   any rough working should be done in this booklet.   a copy of the periodic table is printed on page 20.  you may use a calculator.                                              this document consists of 17 printed pages and 3 blank pages.  ib05 11_0620_01/2rp   \uf6d9 ucles 2005  [turn over  ",
            "2": "2    \u00a9 ucles 2005 0620/01/o/n/05 1 blue copper( ii) sulphate crystals are soluble in water.    a few copper( ii) sulphate crystalsone week laterwater blue solution     what has happened after one week?  a crystallisation  b diffusion  c distillation  d filtration     2 the reaction between solution p and solution q is exothermic.    a student is told to test this statement by mixing equal volumes of the two solutions and measuring the temperature change.    which two pieces of apparatus should the student use?  a balance and clock  b balance and thermometer  c pipette and clock  d pipette and thermometer     ",
            "3": "3    \u00a9 ucles 2005 0620/01/o/n/05  [turn over  3 a coin is dissolved in an acid. chromatography is used to test the solution formed. the diagram  shows the chromatogram obtained.    chromatography paper starting line     what is the coin made from?  a a metal element  b a non-metal element c a mixture of metals d a mixture of non-metals      4 what do the nuclei in hydrogen molecules contain?  a electrons and neutrons  b electrons and protons  c neutrons only  d protons only    5 which statements about isotopic atoms of the same element are correct?    different number of  electrons different number of  neutrons  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "4": "4    \u00a9 ucles 2005 0620/01/o/n/05 6 which diagram shows a positively charged ion?    p n9 10ee ee ee e ee ep n9 10ee e ee ee e ep n3 4e eep n34e e p nekey electron protonneutronnucleusd cb a       7 bottles of sodium hydroxide, sodium chloride and sugar have lost their labels.    students test a sample from each bottle. their results are shown in the table.    bottle addition of water conductivity of solution  1 forms an alkaline solution conducts electricity  2 forms a neutral solution conducts electricity  3 forms a neutral solution does not conduct electricity    what are the correct labels for each bottle?     bottle 1 bottle 2 bottle 3  a sodium hydroxide sodium chloride sugar  b sodium hydroxide sugar sodium chloride  c sodium chloride sugar sodium hydroxide  d sugar sodium hydroxide sodium chloride     ",
            "5": "5    \u00a9 ucles 2005 0620/01/o/n/05  [turn over  8 the diagram shows the structure of hydrogen peroxide.    oo h h    what is the total number of electrons used for bonding in this molecule?  a 3 b 4 c 6 d 8     9 the equation shows the reaction that occurs when ethanol burns in air.    c 2h5oh + x  o2 \u2192 y co 2 + z  h2o    which values of x, y and z are needed to balance this equation?     x y z  a 2 2 2  b 2 2 3  c 2 3 3  d 3 2 3    10 the diagram shows the electrolysis of molten lead( ii) bromide.    heatelectrode x    + electrode y    \u2013 molten lead( ii) bromide     what is seen at each electrode?     electrode x electrode y  a brown gas silvery metal  b brown metal green gas  c green gas brown metal  d silvery metal brown gas   ",
            "6": "6    \u00a9 ucles 2005 0620/01/o/n/05 11 the diagram shown is not complete.    concentrated hydrochloric acidx     what should be shown at x when the solution has been electrolysed for some time?    o2a o2 h2b cl2 h2c h2d h2 cl2      12 which process is endothermic?  a burning hydrogen to form water  b condensing steam to water c melting ice to form water  d reacting sodium with water     13 the elements h 2 and 235u are both used as fuels.    in these processes, the reactions are \u2026..1\u2026.. and \u2026..2\u2026.. oxidised.    which words correctly complete gaps 1 and 2?     1 2  a endothermic both elements are  b endothermic only hydrogen is  c exothermic both elements are  d exothermic only hydrogen is   ",
            "7": "7    \u00a9 ucles 2005 0620/01/o/n/05  [turn over  14 why does the powdering of calcium carbonate increase the speed of its reaction with an acid?  a it increases the mass of calcium carbonate.  b it increases the surface area of the calcium carbonate.  c the powder becomes more concentrated.  d the powder floats on top of the acid.      15 which process does not involve either oxidation or reduction?  a burning methane in the air  b extracting iron from hematite  c heating copper( ii) oxide with carbon  d reacting sodium carbonate with dilute hydrochloric acid      16 an excess of acid in the stomach causes i ndigestion that can be cured by an anti-indigestion  tablet.    what should the tablet contain to decrease the acidity?  a an acidic substance  b an alkaline substance  c a neutral substance  d universal indicator     17 a solution is made by adding sodium oxide to water.    which ph change can occur?     ph change  a 1 \u2192 7  b 7 \u2192 1  c 7 \u2192 12  d 12 \u2192 7    18 which element has an oxide that forms a salt with an alkali?  a n b na c ne d ni    ",
            "8": "8    \u00a9 ucles 2005 0620/01/o/n/05 19 pure zinc sulphate can be prepared by adding an excess of either zinc carbonate or an excess of  zinc hydroxide to dilute sulphuric acid.    in which form are these zinc compounds used?    solid solidsolidaqueous solutionzinc carbonate aqueous solutionzinc hydroxide a aqueous solutionsolidb aqueous solutionc d       20 which aqueous ion causes a yellow precipitate to form when acidified aqueous lead( ii) nitrate is  added to it?  a chloride  b iodide c nitrate d sulphate      21 which information about an element can be used to predict its chemical properties?  a colour of its compounds  b density c melting point d position in the periodic table     ",
            "9": "9    \u00a9 ucles 2005 0620/01/o/n/05  [turn over  22 the table shows some properties of four gases.    which gas is most suitable for filling weather balloons?     density compared  with air chemical reactivity  a higher reactive  b higher unreactive  c lower reactive  d lower unreactive      23 a data book gives the following information about an element.    appearance silver-grey solid  melting point 63  oc  density 0.86  g / cm3  reaction with water vigorous reaction with cold water    where is the element likely to be found in the periodic table?  a group 0  b group i  c group vii  d transition elements      24 calcium, on the left of period 3 of the periodic table, is more metallic than bromine on the right of  this period.    why is this?    calcium has  a fewer electrons.  b fewer protons.  c fewer full shells of electrons.  d fewer outer shell electrons.     ",
            "10": "10    \u00a9 ucles 2005 0620/01/o/n/05 25 brass, an alloy of copper with another element, is used to make the contact pins of electrical  plugs because it is harder than copper.    in brass, the other element is a \u2026.. x\u2026.. that \u2026.. y\u2026.. with the copper.    what are x  and y?     x y  a metal mixes  b metal reacts  c non-metal mixes  d non-metal reacts     26 a student added dilute hydrochloric acid to four metals and recorded his results. not all of his  results are correct.    results    metal gas given off  1 copper yes  2 iron yes  3 magnesium no  4 zinc yes    which two results are correct?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     27 which of the following is made from stainless steel?    aircraft frames car bodies electrical cables knives and forksab c d     ",
            "11": "11    \u00a9 ucles 2005 0620/01/o/n/05  [turn over  28 what is the purpose of the fine sand filter in the purification of the water?    water in water ou tstones gravel coarse sand fine sand     a to allow particles to settle  b to sort particles into layers  c to trap large particles  d to trap small particles      29 what is formed when ethane burns incompletely but not when it burns completely?  a carbon dioxide  b carbon monoxide  c ethene  d hydrogen     ",
            "12": "12    \u00a9 ucles 2005 0620/01/o/n/05 30 the diagrams show experiments to investigate rusting of iron nails.    3 boiled water2 salt water1 tap waterlayer of oil     in which test-tubes do the nails rust?  a 1 only  b 1 and 2 only c 1 and 3 only d 1, 2 and 3      31 the diagrams show three experiments.    heat1 aqueous ammonium sulphate + dilute sulphuric acid heat2 aqueous ammonium nitrate + aqueous sodium nitrate heat3 aqueous ammonium chloride + aqueous sodium hydroxide     in which experiments is ammonia formed?  a 1 only b 2 only c 3 only d 1, 2 and 3     ",
            "13": "13    \u00a9 ucles 2005 0620/01/o/n/05  [turn over  32 in which process is carbon dioxide not formed?  a blast furnace extraction of iron  b burning of natural gas  c heating lime  d oxy-acetylene welding     33 the diagram shows the results of a ph test on a sample of garden soil.    34567 ph8 9 10 11soil reading     what could be added to the soil to change its ph to 7?  a ammonium nitrate  b lime  c sand  d sodium chloride     ",
            "14": "14    \u00a9 ucles 2005 0620/01/o/n/05 34 some students are asked to draw the structure of propanol.    which diagram should the students draw?     ch hchh oh c hhhchh chh chh h h ch hc oo hc hh hch hc hh ch h a b c d      35 acetylene is an unsaturated hydrocarbon used with oxygen in a welding torch.     which diagram shows a molecule of acetylene?    key = c = h= oab c d      ",
            "15": "15    \u00a9 ucles 2005 0620/01/o/n/05  [turn over  36 the table shows the composition of natural gas.    gas % of natural gas  x 93.1   ethane 3.4   nitrogen 2.3     what is x?  a ethanol  b ethene  c methane  d propane     37 which pair of compounds belong to the same homologous series?  a ch 3ch 3 and ch 3ch 2ch 3  b ch 3ch 2oh and ch 3och 2ch 3  c ch 2chch 2ch 3 and ch 3ch 2ch 2ch 3  d ch 3ch 2oh and ch 2chch 2oh    38 the diagram shows the structure of an important product.    ch hchh chh chh chh chh     this product is formed by \u2026..1\u2026.. of an \u2026..2\u2026..    which words correctly complete gaps 1 and 2?     1 2  a addition polymerisation alkane  b addition polymerisation alkene  c cracking alkane  d cracking alkene     ",
            "16": "16    \u00a9 ucles 2005 0620/01/o/n/05 39 an organic compound has the structure shown.    c ccc cch hhhh h hhhh h h     from knowledge of the properties of alkanes and alkenes, which reactions would be predicted for  this compound?     burn decolourise aqueous bromine  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     40 ethanol can be formed by    1 fermentation,  2 reaction between steam and ethene.    which of these processes uses a catalyst?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "17": "17     0620/01/o/n/05   blank page  ",
            "18": "18     0620/01/o/n/05 blank page  ",
            "19": "19      every reasonable effort has been made to trace all copyright holders  where the publishers (i.e. ucles) are aware that third-par ty material has been  reproduced. the publishers would be pleased to hear from any one whose rights they have unwittingly infringed.     0620/01/o/n/05   blank page  ",
            "20": "20      university of cambridge international examinations is part of  the university of cambridge local examinations syndicate (ucles), which is itself a department  of the university of cambridge.   0620/01/o/n/05  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w05_qp_2.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry 0620/02        paper 2 (core)    october/november 2005        1 hour 15 minutes     candidates answer on the question paper.     no additional materials required.                                read these instructions first     write your centre number, candidate number and name on all the work you hand in.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part question.   a copy of the periodic table is printed on page 16.                               for examiner\u2019s use   1    2    3    4    5    6    total     this document consists of 16 printed pages.  ib05 11_0620_02/3rp   \uf6d9 ucles 2005  [turn over  ",
            "2": "2  \u00a9 ucles 2005 0620/02/o/n/05 for  examiner's  use 1 the diagram shows part of the periodic table.        h e   c n o f ne    s cl ar     br kr     (a)  answer these questions using only the elements shown in the diagram.     write down the symbol for an element which  (i)has five electrons in its outer shell,  [1]  (ii) has diatomic molecules,  [1]  (iii) reacts with sodium to form sodium bromide,  [1]  (iv) is a noble gas,  [1]  (v) has a giant covalent structure,  [1]  (vi) has a lower proton number than fluorine,  [1]  (vii) is the most abundant gas in the air.  [1]     (b) write down a use for each of the following elements.    (i) argon   [1]     (ii) helium   [1]     (iii) oxygen   [1]    ",
            "3": "3  \u00a9 ucles 2005 0620/02/o/n/05 [turn over  for  examiner's  use  (c) (i)  draw a diagram to show the electronic structure of argon.                        [2]    (ii) why is argon very unreactive?   [1]    ",
            "4": "4  \u00a9 ucles 2005 0620/02/o/n/05 for  examiner's  use 2 the diagram shows the salt mines at bex in switzerland.      salt solution pumped upmountain side underground reservoir sodium chloride solution rock (mainly anhydrite) layers of saltair vent        the salt is dissolved by water from underground springs and then pumped up to a reservoir  where it is stored as a solution.       (a) write the chemical formula for sodium chloride.   [1]      (b) suggest how solid sodium chloride is obtained from the sodium chloride solution.   [1]     ",
            "5": "5  \u00a9 ucles 2005 0620/02/o/n/05 [turn over  for  examiner's  use  (c) sodium chloride has an ionic giant structure.   which one of the following best describes an aqueous solution of sodium chloride?   tick one box.   a mixture of sodium ions and chlorine molecules in water          a mixture of sodium and chlorine atoms in water          a mixture of sodium and chloride ions in water          a mixture of sodium, chloride, oxide and hydrogen ions       [1]      (d) describe a test for chloride ions.  test   result  [2]       (e)  the rock surrounding the layers of salt is anhydrite.   pure anhydrite has the chemical formula caso 4.    (i) state the name of the chemical found in anhydrite.   [1]    (ii) calculate the relative formula mass of the chemical in pure anhydrite.          [1]    (iii) when anhydrite reacts with water, gypsum (caso 4.2h 2o) is formed.   complete the equation for this reaction.  caso 4 +   caso 4.2h 2o  [1]     (iv) which one of the following describes this reaction?   put a ring around the correct answer.  combustion fermentation hydration oxidation reduction [1]   ",
            "6": "6  \u00a9 ucles 2005 0620/02/o/n/05 for  examiner's  use  (v) the chemical in anhydrite can be made by reacting calcium hydroxide with  sulphuric acid.   complete the balanced equation for this reaction.  ca(oh) 2 +   caso 4 +  h2o [2]     (vi) the spring water running through the rocks changes anhydrite into gypsum.   this reaction is exothermic.   use this information to explain why the temperature of the mine never falls below  17  oc even in cold winters.     [1]      (f) the air inside the mine contains 19% oxygen.   which one of the following best describes the oxygen level inside the mine compared  with that outside the mine?   tick one box.   the level of oxygen inside the mine is higher          the level of oxygen is the same          the level of oxygen is about a quarter of that of the outside air          the level of oxygen inside the mine is lower       [1]    ",
            "7": "7  \u00a9 ucles 2005 0620/02/o/n/05 [turn over  for  examiner's  use 3 hydrogen peroxide solution, h 2o2, decomposes slowly in the absence of a catalyst.   oxygen and water are formed.    2h2o2(aq) 2h 2o(l)   +   o 2(g)    (a) draw a diagram of the apparatus you could use to investigate the speed of this  reaction.   you must label your diagram.                        [3]     (b) catalyst x was added to 50cm 3 of hydrogen peroxide solution at 20oc and the amount  of oxygen given off was recorded over a two minute period.   the experiment was repeated with the same amounts of catalyst y and catalyst z.   apart from the type of catalyst, all conditions were kept the same in the three experiments.  a graph of the results is shown below.   60 5040302010 30 60 time  / seconds90 1200volume of oxygengas  / cm3x y z      (i) what is a catalyst?   [1]   ",
            "8": "8  \u00a9 ucles 2005 0620/02/o/n/05 for  examiner's  use  (ii) which catalyst, x, y or z, produced oxygen gas the fastest?   explain your answer.     [2]     (iii) why is the final amount of oxygen gas the same in each experiment?     [1]     (iv) many transition metals and their oxides are good catalysts.   state two other properties of transition metals which are not shown by other  metals.     [2]       (c) the experiment with catalyst z was repeated at 40oc.    all other conditions were kept the same.  the speed of the reaction increased.  explain why, using ideas about particles.       [2]       (d) some enzymes also catalyse the decomposition of hydrogen peroxide.     (i) state one difference between an enzyme and an inorganic catalyst such as a  transition metal.   [1]    (ii) enzymes are also responsible for fermentation reactions.   which one of the following equations a, b, c or d describes fermentation?     c6h12o6   +   6o 2 a 6co 2   +   6h 2o c2h4   +   h 2o b c2h5oh c6h12o6 c 6c   +   6h 2o c6h12o6 d 2c2h5oh   +   2co 2     [1]   ",
            "9": "9  \u00a9 ucles 2005 0620/02/o/n/05 [turn over  for  examiner's  use 4 the list shows some oxides.  calcium oxide  magnesium oxide  nitrogen dioxide  sodium oxide  sulphur dioxide     (a) from this list choose two oxides which are basic.   give a reason for your answer.      [2]      (b) (i)  which two oxides from this list contribute to acid rain?   [2]    (ii) how do each of these oxides get into the atmosphere?  name of oxide    source of oxide  [1]  name of oxide    source of oxide  [1]      (c) calcium oxide is manufactured from calcium carbonate.    (i) complete the word equation for this reaction.  calcium carbonate   calcium oxide +  [1]     (ii) what condition is needed for this reaction to take place?   [1]     ",
            "10": "10  \u00a9 ucles 2005 0620/02/o/n/05 for  examiner's  use  (d) (i)  explain why calcium oxide and sodium oxide cannot be reduced by heating with  carbon.   [1]     (ii) copper( ii) oxide can be reduced by heating with carbon.   complete the equation for this reaction.   cuo + c  2cu +   [2]     (iii) what do you understand by the term reduction ?     [1]     ",
            "11": "11  \u00a9 ucles 2005 0620/02/o/n/05 [turn over  for  examiner's  use 5 the structures of some organic compounds are shown below.      c hh ch h hchh chh h c hh chh hchh chh o h c hh h h ab c hh ch hch ch hh dc hh co ohh ec       (a) name compound a.   [1]     (b) which two of the compounds a to e belong to the same homologous series?   [1]     (c) (i)  which one of the compounds a to e has the same functional group as ethanol?   [1]     (ii) draw the structure of ethanol, showing all atoms and bonds.             [2]    (iii) describe how ethanol is made in industry from ethene.     [2]   ",
            "12": "12  \u00a9 ucles 2005 0620/02/o/n/05 for  examiner's  use  (d) (i)  which one of the compounds a to e is an unsaturated hydrocarbon?   [1]     (ii) describe a chemical test for an unsaturated hydrocarbon.  test   result  [2]      (e) compound e is acidic.     (i) state the name of compound e.   [1]     (ii) describe a test to show that compound e is acidic.  test   result  [2]     ",
            "13": "13  \u00a9 ucles 2005 0620/02/o/n/05 [turn over  for  examiner's  use 6 the diagram shows an electrolysis cell used to extract aluminium.      + ++ \u2013 electrolyte (aluminium compound dissolvedin cryolite)negativeelectrodepositiveelectrode moltenaluminium       (a) what compound of aluminium is used for the electrolyte?   [1]     (b) the electrolyte must be molten for the electrolysis to work.   explain why.   [1]     (c) (i)  state the name of the substance used for the electrodes.   [1]     (ii) to which electrode do the aluminium ions move during electrolysis?   explain your answer.     [2]       (d) complete the following sentences about the molten electrolyte using words from the list  below.    bauxite chemical cryolite decreased  electrical haematite increased light      the melting point of the electrolyte is  by adding  . this means that less  energy is needed to melt the electrolyte.  [3]     ",
            "14": "14  \u00a9 ucles 2005 0620/02/o/n/05 for  examiner's  use  (e) aluminium is used in overhead power cables.      aluminium steel core pylonsteel cored aluminium cables        the table shows some properties of three metals which could be used for the power  cables.    metal relative electrical  conductivity density  / grams per cm3 price  / \u00a3 per kg relative  strength  aluminium 0.4 2.70 18 9  copper 0.7 8.92 15 30  steel 0.1 7.86 2.7 50       (i) suggest why aluminium is used for overhead power cables rather than copper.   [1]     (ii) suggest why steel is not used alone for overhead power cables.   [1]    (iii) why is steel used as a core for overhead power cables?   [1]    (iv) electrical insulators are used in parts of the pylons which carry the electrical cables.   which one of the following is an electrical insulator?  put a ring around the correct answer.   aluminium ceramic graphite zinc [1]    ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.    \u00a9 ucles 2005 0620/02/o/n/05 for  examiner's  use  (f) aluminium has many uses.    (i) why is aluminium used for aircraft bodies?   [1]     (ii) describe a test for aluminium ions.  test   result    [3]  ",
            "16": "16  \u00a9 ucles 2005 0620/02/o/n/05    group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89                9 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w05_qp_3.pdf": {
            "1": "this document consists of 14 printed pages and 2 blank page.  ib05 11_0620_03/5rp   \u00a9 ucles 2005    [turn over   university of cambridge international examinations   international general certificate of secondary education       chemistry       paper 3 (extended) 0620/03        october/november 2005       1 hour 15 minutes   candidates answer on the question paper.   no additional materials required.                                  read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen.  you may use a pencil for any diagrams, graphs or rough working.  write in the boxes provided on the question paper  do not  write in the barcode.  do not  write in the grey areas between the pages.  do not use staples, paper clips, highlighters, glue or correction fluid.  you may use a calculator.    answer all questions.  the number of marks is given in brackets [  ] at the end of each question   or part question.  a copy of the periodic table is printed on page 16. candidate name centrenumber candidatenumbe r*062003* for examiner's use 1 234 5 67 total",
            "2": "2  \u00a9 ucles 2005 0620/03/o/n/05 for  examiner's  use1 (a)  the structure of a typical ionic compound is a regular arrangement of positive and  negative ions.      + \u2013 + \u2013 + \u2013 + \u2013 +\u2013 + \u2013+ \u2013 + \u2013 \u2013 + \u2013 + + \u2013 + \u2013     (i) what is the name of this regular arrangement of particles?   [1]       (ii) give two physical properties of ionic compounds.     [2]        (b) ions are formed by electron loss or gain.  the electron distribution of a magnesium  atom is 2 + 8 + 2 and of a nitrogen atom is 2 + 5.    (i) give the formula of the magnesium ion.   [1]      (ii) give the formula of the nitride ion.   [1]      (iii) what is the formula of the ionic compound, magnesium nitride?   [1]     (iv)  in this compound there is an ionic bond. why are the two ions attracted to each  other?   [1]   ",
            "3": "3  \u00a9 ucles 2005 0620/03/o/n/05 [turn over  for  examiner's  use 2 ethanoic acid is a colourless liquid at room temperature.  it has the typical acid properties  and forms compounds called ethanoates.    (a) a pure sample of ethanoic acid  is slowly heated from 0 oc  to 150oc and its temperature  is measured every minute.  the results are represented on the graph below.     temperature timeab cdef      (i) name the change that occurs in the region d to  e.   [1]     (ii) what would be the difference in the region b to c if an impure sample had been  used?   [1]     (iii) sketch on the graph how the line would continue if the acid was heated to a higher  temperature. [1]    ",
            "4": "4  \u00a9 ucles 2005 0620/03/o/n/05 for  examiner's  use (iv)  complete the following table that compares the separation and movement of the  molecules in regions c to d with those in e to f.     c to d e to f    separation (distance  between particles)            movement of particles  random and slow        can particles move apart to  fill  any volume?         [5]       (b) complete the word equations for the reactions of ethanoic acid.  calcium + ethanoic acid      +      + ethanoic acid  zinc ethanoate + water [2]     (c) write the symbol equation for the reaction between ethanoic acid and sodium  hydroxide.   [2]   ",
            "5": "5  \u00a9 ucles 2005 0620/03/o/n/05 [turn over  for  examiner's  use 3 reversible reactions can come to equilibrium. they have both a forward and a backward  reaction.     (a) when water is added to an acidic solution of bismuth( iii) chloride, a white precipitate  forms and the mixture slowly goes cloudy.      bic/k6c 3(aq)   +   h 2o(l) bioc/k6c(s)   +   2hc /k6c(aq) colourless whiteforward backward      (i) explain why the rate of the forward reaction decreases with time.     [2]      (ii) why does the rate of the backward reaction increase with time?     [1]      (iii) after some time why does the appearance of the mixture remain unchanged?     [2]      (iv) when a few drops of concentrated hydrochloric acid are added to the cloudy mixture, it changes to a colourless solution. suggest an explanation.     [2]     ",
            "6": "6  \u00a9 ucles 2005 0620/03/o/n/05 for  examiner's  use (b) both of the following reactions are reversible.      n2(g)   +   o 2(g) reaction 1 2no(g) 2no(g)   +   o 2(g) reaction 2 2no 2(g)      (i) suggest a reason why an increase in pressure does not affect the position of  equilibrium for reaction 1.   [1]      (ii) what effect would an increase in pressure have on the position of equilibrium for  reaction 2? give a reason for your answer.     [2]   ",
            "7": "7  \u00a9 ucles 2005 0620/03/o/n/05 [turn over  for  examiner's  use 4 the alcohols form a homologous series. the first member is methanol and the fourth is  butanol.    ch 3ch 2 ch 3oh ch 2ch 2oh methanol butanol      (a) (i)  give two general characteristics of a homologous series.       [2]       (ii) calculate the mass of one mole of the c 8 alcohol.     [2]       (b) give the name and structural formula of the third member of this series.  name  [1]  structural formula             [1]       (c) the structural formula of the fifth member, pentan-1-ol, is drawn below.    ch 3ch 2ch 2ch 2ch 2oh     (i) draw the structural formula of an isomer of this alcohol.              [1]   ",
            "8": "8  \u00a9 ucles 2005 0620/03/o/n/05 for  examiner's  use  (ii) predict the names of the product(s) formed when pentan-1-ol   \u007f  reacts with an excess of oxygen,    and  [1] \u007f  is dehydrated to form an alkene,     [1] \u007f  is oxidised by acidified potassium dichromate( vi).    [1]  ",
            "9": "9  \u00a9 ucles 2005 0620/03/o/n/05 [turn over  for  examiner's  use 5 strontium and zinc are both metals with a valency of 2. strontium is more reactive than zinc.   its chemistry is similar to that of calcium.    (a) (i)  complete the following table that shows the number of protons, electrons and  neutrons in each particle.    particle protons electrons neutrons  88sr     90sr     65zn2+      [3]     (ii) explain why  88sr and 90sr are isotopes.   [1]     (iii) complete the electron distribution of an atom of strontium.  2 + 8 + 18 +  +  [1]       (b) the major ore of zinc is zinc blende, zns.    (i) describe how zinc is extracted from zinc blende.       [2]      (ii) give a use of zinc.   [1]    ",
            "10": "10  \u00a9 ucles 2005 0620/03/o/n/05 for  examiner's  use (c) the major ore of strontium is its carbonate, srco 3.  strontium is extracted by the  electrolysis of its molten chloride.     (i) name the reagent that will react with the carbonate to form the chloride.   [1]    (ii) the electrolysis of molten strontium chloride produces strontium metal and  chlorine. write ionic equations for the reactions at the electrodes.  negative electrode (cathode)    positive electrode (anode)  [2]    (iii) one of the products of the electrolysis of concentrated aqueous strontium chloride is chlorine.  name the other two.   [2]       (d) both metals react with water.    (i) write a word equation for the reaction of zinc and water and state the reaction  conditions.  word equation  [1]  conditions  [2]     (ii) write an equation for the reaction of strontium with water and give the reaction  condition.  equation  [2]  condition  [1]   ",
            "11": "11  \u00a9 ucles 2005 0620/03/o/n/05 [turn over  for  examiner's  use 6 (a)  the following method is used to make crystals of hydrated nickel sulphate.     an excess of nickel carbonate, 12.0 g, was added to 40 cm3 of sulphuric acid, 2.0  mol/dm3. the unreacted nickel carbonate was filtered off and the filtrate evaporated to  obtain the crystals.     nico 3   +   h 2so 4 niso 4   +   co 2   +   h 2o niso 4   +   7h 2o niso 4.7h 2o     mass of one mole of niso 4.7h 2o  =  281 g   mass of one mole of nico 3  =  119 g     (i) calculate the mass of unreacted nickel carbonate.  number of moles of h 2so 4 in 40 cm3 of  2.0 mol/dm3 acid  = 0.08  number of moles of nico 3 reacted  =      mass of nickel carbonate reacted  =    g   mass of unreacted nickel carbonate  =  g [3]    (ii) the experiment produced 10.4  g of hydrated nickel sulphate. calculate the  percentage yield.  the maximum number of moles of niso 4 .7h 2o that could be formed =      the maximum mass of niso 4 .7h 2o that could be formed  =   g   the percentage yield  =    % [3]     (b) in the above method, a soluble salt was prepared by neutralising an acid with an  insoluble base. other salts have to be made by different methods.     (i) give a brief description of how the soluble salt, rubidium sulphate could be made  from the soluble base, rubidium hydroxide.         [3]     ",
            "12": "12  \u00a9 ucles 2005 0620/03/o/n/05 for  examiner's  use (ii) suggest a method of making the insoluble salt, calcium fluoride.         [3]   ",
            "13": "13  \u00a9 ucles 2005 0620/03/o/n/05 for  examiner's  use 7 in 1909, haber discovered that nitrogen and hydrogen would react to form ammonia.  the  yield of ammonia was 8%.    n2 (g)  +  3h 2 (g)  2nh 3 (g)     the forward reaction is exothermic    catalyst platinum  temperature 600  oc   pressure  200  atm     (a) describe how hydrogen is obtained for the modern process.     [2]       (b) (i)  what is the catalyst in the modern process?   [1]     (ii) explain why the modern process, which uses a lower temperature, has a higher  yield of 15%.     [2]       (c) (i)  complete the following table that describes the bond breaking and forming in the  reaction between nitrogen and hydrogen to form ammonia.    bonds energy change  /kj exothermic or endothermic   1 mole of n  n  broken +945     3 moles of      broken   +1308      6 moles of n \u2013 h  formed -2328      [3]     (ii) explain, using the above data, why the forward reaction is exothermic.     [2]  ",
            "14": "14   0620/03/o/n/05 blank page ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here  possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring  clearance  have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he university of cambridge local examinations syndicate (ucles),  which is  itself a department of the university of cambridge.     0620/03/o/n/05 blank page ",
            "16": "16   0620/03/o/n/05    group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89                9 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w05_qp_5.pdf": {
            "1": "this document consists of 7 printed pages and 1 blank page.  ib05 11_0620_05/5rp   \u00a9 ucles  2005  [turn over   university of cambridge international examinations   international general certificate of secondary education       chemistry       paper 5 practical test 0620/05        october/november 2005      candidates answer on the question paper.   additional materials:  as listed in instructions  1 hour 15 minutes    to supervisors                                     read these instructions first    write your name, centre number and candidate number on all the work you hand in.  write in dark blue or black pen in the spaces provided on the question paper.  you may use a pencil for any diagrams, graphs or rough working.  do not  write in the barcode.  do not  write in the grey areas between the pages.  do not use staples, paper clips, highlighters, glue or correction fluid.   you may use a calculator.  answer all questions.  the number of marks is given in brackets [  ] at the end of each question or part question.   practical notes are provided on page 8.  candidate name centrenumber candidatenumbe r*062005*    for examiner's use total1 2",
            "2": "2  \u00a9 ucles 2005 0620/05/o/n/05 for  examiner's  use1 you are going to investigate the speed of reaction between aqueous hydrochloric acid and  marble chips (calcium carbonate).     read all the instructions  below carefully before starting the experiments.     instructions      put 5 test-tubes in a line in the rack provi ded so you can see the graph paper through them.     to each test-tube you are going to add 3  cm3 of different solutions of aqueous hydrochloric  acid and a marble chip. the marble chips are the same size.     experiment 1     using the measuring cylinder pour 3  cm3 of the solution p of aqueous hydrochloric acid into  the first test-tube.    experiment 2     using the measuring cylinder pour 3  cm3 of the solution q of aqueous hydrochloric acid into  the second test-tube.     experiments 3, 4 and 5      repeat experiment 1 using 3  cm3 of the solutions of aqueous hydrochloric acid r, s and t  in the third, fourth and fifth test-tubes.     into all of the test-tubes quickly place a marble chip and start the timer. shake the tubes  from time to time.     look at the tubes from the side. take the time in seconds for each  tube when the lines on  the graph paper can be seen through all of the acid in that tube . do not stop the timer  until all the reactions are finished.     record the times in the table.    table of results     experiment solution of  hydrochloric acid time/s  1 p   2 q   3 r   4 s   5 t    [3] ",
            "3": "3  \u00a9 ucles 2005 0620/05/o/n/05 [turn over  for  examiner's  use  (a) plot your results on the grid. draw a best-fit straight line graph.    time/s 12345 experiment number     [4]      (b) describe how the appearance of the mixture in the test-tubes changed as you timed the  reaction.     [3]       (c) (i) which experiment has the fastest rate of reaction?   [1]    (ii) explain why this experiment has the fastest rate.       [2]  ",
            "4": "4  \u00a9 ucles 2005 0620/05/o/n/05 for  examiner's  use (d) (i) in the experiments which of the reactants is in excess ?   [1]     (ii) explain your answer to (d)(i) .     [2]      (e) (i) state two sources of error in the experiments.  1     2    [2]     (ii) suggest two improvements to reduce the sources of error in the experiments.  1     2    [2]     ",
            "5": "5  \u00a9 ucles 2005 0620/05/o/n/05 [turn over  for  examiner's  use 2 you are provided with a solid compound x.     carry out the following tests on x, recording all of your observations in the table. do not  write any conclusions in the table.    tests observations   (a) appearance of solid x.     [2]                   [4]   (b) place one spatula measure of  x into a hard-glass test-tube.  heat gently then strongly. test any gases with damp ph indicator paper. note all  observations.       add the rest of solid x to a  test-tube. add about 10  cm3 of  distilled water and shake to  dissolve. divide the solution into five portions in test-tubes.           (c) (i) by using a teat pipette add drops of aqueous  sodium hydroxide to the  first portion of the solution. now add excess aqueous sodium hydroxide to the  test-tube.   [3]              [3]   (ii) using the second portion  repeat experiment (c)(i)   using aqueous ammonia instead of aqueous  sodium hydroxide.    ",
            "6": "6  \u00a9 ucles 2005 0620/05/o/n/05 for  examiner's  use         [1]            [1]     (iii) to the third portion of  solution add a few drops  of hydrochloric acid and  about 1  cm3 of barium  chloride solution.   (iv) to the fourth portion of  solution add a few drops  of nitric acid and about    1  cm3 of lead nitrate  solution.      (v) to the fifth portion of  solution add aqueous  sodium hydroxide and a  spatula measure of aluminium granules. warm carefully  and test  the gas with damp indicator paper.     [2]        (d) what do tests (c)(iii)  and (iv)  tell you about x?   [1]     (e) what conclusions can you draw about substance x?         [3]   ",
            "7": "7   0620/05/o/n/05 blank page",
            "8": "8    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here  possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring  clearance  have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he university of cambridge local examinations syndicate (ucles),  which is  itself a department of the university of cambridge.    \u00a9 ucles 2005 0620/05/o/n/05 notes for use in qualitative analysis     test for anions     anion test test result  carbonate (co-2 3) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then  aqueous lead( ii) nitrate yellow ppt.  nitrate (no\u2212 3)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulphate (so-2 4)  [in solution] acidify with dilute nitric acid, then  aqueous barium nitrate white ppt.   test for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh+ 4) ammonia produced on warming -  calcium (ca2+) white., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution   test for gases     gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_w05_qp_6.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry  0620/06         paper 6  alternative to practical    october/november 2005        1 hour    candidates answer on the question paper.     no additional materials required.                           read these instructions first     write your name, centre number and candidate number at the top of this page.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part question.                             for examiner\u2019s use   1    2    3    4    5    6    7    total       this document consists of 12 printed pages.  ib05 11_0620_06/4rp   \uf6d9 ucles 2005  [turn over    if you have been given a label, look at the  details. if any details are incorrect or  missing, please fill in your correct details in the space given at the top of this page.    stick your personal label here, if provided.   ",
            "2": "2  \u00a9 ucles 2005 0620/06/o/n/05 for  examiner's  use 1 a student reacted sulphuric acid with copper( ii) oxide. the diagram shows the procedure  followed.    dilute sulphuric acid50 cm3 of dilute sulphuric acid was measured into a beakercopper oxide was added until all the sulphuric acidhad reacted warm         (a) complete the boxes to identify the pieces of apparatus labelled. [3]      (b) what is the colour of the solution formed?   [1]       (c) describe how crystals could be quickly obtained from the solution.     [2]     ",
            "3": "3  \u00a9 ucles 2005 0620/06/o/n/05 [turn over  for  examiner's  use 2 the diagram shows the apparatus used to pass an electric current through concentrated  hydrochloric acid.     chlorine hydrogen      (a) label the electrodes. [1]     (b) give two observations when the current is switched on.  1   2  [2]      (c) give a test for the product at the negative electrode (cathode).  test   result  [2]     ",
            "4": "4  \u00a9 ucles 2005 0620/06/o/n/05 for  examiner's  use 3 the green pigment chlorophyll can be obtained from grass.     step 1 the grass is crushed with sand.   step 2 the grass is ground with ethanol until the solution is saturated.     step 3 the solution is separated from the rest of the mixture.   step 4 the colours in the solution are separated.      (a) what apparatus is used in step 1?   [2]       (b) suggest why the grass is ground with et hanol rather than water in step 2.   [1]      (c) name the separation method in step 3.   [1]       (d) describe how step 4 is carried out.                              [4]   ",
            "5": "5  \u00a9 ucles 2005 0620/06/o/n/05 [turn over  4 a student investigated the speed of reaction between aqueous hydrochloric acid and marble  chips (calcium carbonate).    the apparatus below was used.     marble chiphydrochloric acid       5 test-tubes were put in a rack. to each test-tube was added 10  cm3 of different solutions of  aqueous hydrochloric acid and a marble chip. the marble chips were the same size.     experiment 1     by using a measuring cylinder 10  cm3 of the solution p of aqueous hydrochloric acid was placed  in the first test-tube. a marble chip was added and the volume of gas collected after two minutes was measured. use the gas syringe diagram to record the volume.     70 10 20 30 40 50 60 80     experiment 2      experiment 1 was repeated using the solution q of aqueous hydrochloric acid. use the diagram  to record the volume of gas collected in the table.      70 10 20 30 40 50 60 80     ",
            "6": "6  \u00a9 ucles 2005 0620/06/o/n/05 for  examiner's  use  experiments 3, 4 and 5      experiment 1 was repeated using the solutions r, s and t of aqueous hydrochloric acid in  the third, fourth and fifth test-tubes.     use the diagrams to record the volumes in the table.    experiment 3       70 10 20 30 40 50 60 80       experiment 4      70 10 20 30 40 50 60 80       experiment 5       70 10 20 30 40 50 60 80       table of results       experiment solution of  hydrochloric acid volume of gas collected  / cm3  1 p   2 q   3 r   4 s   5 t      [3]     ",
            "7": "7  \u00a9 ucles 2005 0620/06/o/n/05 [turn over  for  examiner's  use  (a) plot your results on the grid. draw a straight line graph.    60 50403020 12345 volume of gas  / cm3 experiment number     [4]    (b) which result appears inaccurate? give a reason for your choice.  experiment   reason  [2]       (c) (i) which experiment had the fastest rate of reaction?   [1]     (ii) suggest why this experiment was the fastest.       [2]   ",
            "8": "8  \u00a9 ucles 2005 0620/06/o/n/05 for  examiner's  use  (d) how would the student know which of the reactants in the experiment was in excess ?     [2]       (e) (i) state one possible source of error in the experiments.     [1]     (ii) suggest one  improvement to reduce this source of error in the experiments.     [1]     ",
            "9": "9  \u00a9 ucles 2005 0620/06/o/n/05 [turn over  for  examiner's  use 5 a solid compound x was analysed. solid x was an aluminium salt. the tests on x and  some of the observations are in the following table.     complete the observations in the table.   tests observations  condensation at top of tube  (a) one spatula measure of x was  placed into a hard-glass test-tube. the solid was heated gently then strongly. the gas was tested with ph indicator  paper. paper went red               [3]         [3]     no visible change  no visible change  pungent gas distilled water was added to x and  shaken to dissolve. the solution was divided into five portions in  test-tubes.   (b) (i) to the first portion, drops  of aqueous sodium  hydroxide were added. excess aqueous sodium hydroxide was then added.     (ii) to the second portion,  drops of aqueous ammonia were added.   excess ammonia was  then added.     (iii) to the third portion of  solution, hydrochloric acid  and barium chloride solution were added.   (iv) to the fourth portion of  solution, nitric acid and lead nitrate solution were  added.   (v) to the fifth portion,  aqueous sodium hydroxide and a spatula  measure of aluminium granules were added. the mixture was warmed and  the gas tested with  indicator paper. paper went blue, ph 10  ",
            "10": "10  \u00a9 ucles 2005 0620/06/o/n/05 for  examiner's  use  (c) what does test (a) tell you about the gas given off?   [1]      (d) what conclusions can you draw about x from tests (b)(iii)  and (iv)?  (b)(iii)    (b)(iv)   [2]     (e) identify the gas in (b)(v) .   [1]     (f) what conclusions can you draw about substance x?     [2]     ",
            "11": "11  \u00a9 ucles 2005 0620/06/o/n/05 [turn over  for  examiner's  use 6 the diagram shows how ethene can be made by cracking liquid alkanes.      waterliquid alkane on mineralfibrealuminiumoxide ethene       (a) indicate with arrows on the diagram where heat is applied. [2]       (b) give a chemical test to show the presence of ethene.  test   result  [2]       (c) why must the delivery tube be removed from the water before the heat is turned off?   [2]   ",
            "12": "12    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.    \u00a9 ucles 2005 0620/06/o/n/05 for  examiner's  use 7 some plants do not grow well in acidic soil.   a farmer gives you a small sample of soil from a corner of one of his fields.   (a) plan an investigation to find out the ph of the soil sample.     you are provided with universal indicator solution and common laboratory apparatus.             [5]       (b) why would further experiments be necessary to inform the farmer which plants should  be grown in each of his fields?     [2]     "
        }
    },
    "2006": {
        "0620_s06_qp_1.pdf": {
            "1": "        university of cambridge international examinations    international general certificate of secondary education        chemistry 0620/01       paper 1  multiple choice    may/june 2006        45 minutes     additional materials: multiple choice answer sheet      soft clean eraser      soft pencil (type b or hb is recommended)                          read these instructions first     write in soft pencil.    do not use staples, paper clips, highlighters, glue or correction fluid.   write your name, centre number and candidate number on the answer sheet in the spaces provided unless   this has been done for you.      there are forty  questions on this paper. answer all questions. for each question there are four possible    answers  a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.     read the instructions on the answer sheet very carefully.     each correct answer will score one mark. a mark will not be deducted for a wrong answer.   any rough working should be done in this booklet.   a copy of the periodic table is printed on page 20.  you may use a calculator.                                              this document consists of 18 printed pages and 2 blank pages.  ib06 06_0620_01/3rp   \uf6d9 ucles 2006  [turn over  ",
            "2": "2    \u00a9 ucles 2006 0620/01/m/j/06 1 at room temperature, in which substance are the particles furthest apart?  a h2 b h2o c mg d mgo     2 which method can be used to obtain crystals from aqueous copper( ii) sulphate?  a chromatography  b electrolysis  c evaporation  d neutralisation    3 five elements have proton numbers 10, 12, 14, 16 and 18.    what are the proton numbers of the three elements that form oxides?  a 10, 12 and 14  b 10, 14 and 18  c 12, 14 and 16  d 14, 16 and 18     4 the rows p, q and r in the table show three pairs of structures.   2p1nee 2p2nee pnekey electron neutronprotonnucleus atoms of the  same elementp q r hh h hc h hh hch hc     which pair or pairs are isotopes?  a p only b p and q only c q only d q and r only ",
            "3": "3    \u00a9 ucles 2006  0620/01/m/j/06  [turn over  5 which numbers are added to give the nucleon number of an ion?  a number of electrons + number of neutrons   b number of  electrons + number of protons  c number of electrons + number of protons + number of neutrons  d number of protons + number of neutrons      6 in the molecules ch 4, hcl and h 2o, which atoms use all of their outer shell electrons in bonding?  a c and c l  b c and h  c cl and h  d h and o      7 which change to an atom occurs when it forms a positive ion?  a it gains an electron.  b it gains a proton.  c it loses an electron.  d it loses a proton.     8 for which compound is the formula correct?    compound formula  a ammonia nh 4  b carbon dioxide co  c potassium oxide p 2o  d zinc chloride znc l2     ",
            "4": "4    \u00a9 ucles 2006 0620/01/m/j/06 9 the diagrams show the molecules of three elements.    123    which of these elements are present in water?  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3     10 the diagram shows that two gases are formed when concentrated hydrochloric acid is  electrolysed between inert electrodes.    + ve \u2013 ve concentrated hydrochloric acid    which line correctly describes the colours of the gases at the electrodes?     anode (+ve) cathode (\u2013ve)  a colourless colourless  b colourless yellow-green  c yellow-green colourless  d yellow-green yellow-green     ",
            "5": "5    \u00a9 ucles 2006  0620/01/m/j/06  [turn over  11 the diagram shows an electrolysis experiment to electroplate nickel with a different metal.    1 ni2 ni3 ni4 ni aqueous copper( ii) sulphateaqueous sodium chloride+\u2013     which nickel electrodes are plated with a metal?  a 1 only  b 1 and 3 only  c 2 only  d 2 and 4 only      12 the diagram shows an experiment in which magnesium oxide powder is added to dilute  hydrochloric acid.    dilute hydrochloric acid 20  oc ph2aqueous magnesium chloride22  oc ph7 before aftermagnesium oxide powder     which terms describe the experiment?     exothermic neutralisation  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "6": "6    \u00a9 ucles 2006 0620/01/m/j/06 13 coal, methane and hydrogen are burned as fuels.    which descriptions of this process are correct?     what happens to the fuel type of reaction  a oxidised endothermic  b oxidised exothermic  c reduced endothermic  d reduced exothermic     14 two reactions involving water are shown.    x feso 4 + water \u2192 hydrated iron( ii) sulphate  y fe + o 2 + water \u2192 rust    which of these reactions are reversible by heating?     x y  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "7": "7    \u00a9 ucles 2006  0620/01/m/j/06  [turn over  15 the diagram shows a speed of reaction experiment.    excess of dilute hydrochloric acid at 25 ochydrogen magnesium     increasing the concentration of the acid and incr easing the temperature both affect the speed of  reaction.   which line of the table is correct?     increase concentration of  acid increase temperature  a decrease speed of reaction decrease speed of reaction  b decrease speed of reaction increase speed of reaction  c increase speed of reaction decrease speed of reaction  d increase speed of reaction increase speed of reaction      16 barium hydroxide is an alkali. it reacts with hydrochloric acid.     ph meter hydrochloric acidaqueous bariumhydroxide     what happens to the ph of a solution of hydrochloric acid as an excess of aqueous barium  hydroxide is added?   a the ph decreases from 14 but becomes constant at 7.  b the ph decreases from 14 to about 1.  c the ph increases from 1 but becomes constant at 7.  d the ph increases from 1 to about 14.   ",
            "8": "8    \u00a9 ucles 2006 0620/01/m/j/06 17 element x is at the left-hand side of the periodic table.     which line in the table shows the correct type and property of the oxide of x?     type of oxide property of oxide  a metallic acidic  b metallic basic  c non-metallic acidic  d non-metallic basic     18 the diagram shows the positions of some elements in the periodic table.    w x yz     which elements form ionic bonds with oxygen?  a w only  b w and x only  c y only  d y and z only     ",
            "9": "9    \u00a9 ucles 2006  0620/01/m/j/06  [turn over  19 the diagrams show three experiments using dilute sulphuric acid. three different powders are  added to the acid.    1 2 3h2so 4(aq)cu powder h2so 4(aq) h2so 4(aq)cu(oh) 2 powder cuco 3 powder     the mixtures are stirred.    which test-tubes then contain cu2+(aq) ions?  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3      20 the equation shows the reaction bet ween a halogen and aqueous bromide ions.    x2 + 2br\u2013(aq) \u2192 2x\u2013(aq) + br 2  \u20261\u2026 \u20262\u2026 \u20263\u2026    which words should be written in gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     ",
            "10": "10    \u00a9 ucles 2006 0620/01/m/j/06 21 the diagram shows an outline of part of the periodic table.    yw x z     which two elements could form a covalent compound?  a w and x b w and y c x and y d x and z     22 a student is asked to complete two sentences.    metallic and non-metallic elements are classified in the \u2026\u20261\u2026\u2026. this can be used to \u2026\u20262\u2026\u2026  the properties of elements.    which words correctly complete the gaps?     gap 1 gap 2  a periodic table measure  b periodic table predict  c reactivity series measure  d reactivity series predict      23 the diagram shows three balloons held by children.    p carbon dioxideq heliumr hydrogen     which of the balloons float up into the air when the children let go?  a p only  b p and r only  c q only  d q and r only     ",
            "11": "11    \u00a9 ucles 2006  0620/01/m/j/06  [turn over  24 three mixtures are made.    1 c + fe 2o3   2 cu + fe 2o3  3 mg + fe 2o3    the mixtures are heated strongly.    which of the elements c, cu and mg are reactive enough to reduce the iron oxide to iron?  a c and cu only  b c and mg only c cu and mg only  d c, cu and mg      25 which property do all metals have?  a their densities are low.  b their melting points are high.  c they act as catalysts.  d they conduct electricity.    26 copper, iron and zinc are all used to make things.    which of these three metals are also used in the form of alloys?     copper iron zinc  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0017 \u0013    27 which diagram shows a common use of stainless steel?    d ab c      ",
            "12": "12    \u00a9 ucles 2006 0620/01/m/j/06 28 the diagram shows stages in the purification of water.    which stage uses chlorine?    water at ph9 + bacteria+ large solids+ fine solidswater at ph9+ bacteria+ fine solidswater at ph9+ bacteria water at ph7+ bacteriapure waterat ph7ab c d       29 in experiments on rusting, some students are each given two metal objects to study.    one student set up his apparatus as shown.    chrome- platedkeyring waterair nitrogen brass screw     which objects rusted?     brass screw chrome-plated  keyring  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      30 which substance is not a pollutant of clean air?  a argon  b carbon monoxide  c nitrogen dioxide  d sulphur dioxide   ",
            "13": "13    \u00a9 ucles 2006  0620/01/m/j/06  [turn over  31 which metallic element is needed in a complete fertiliser?  a calcium  b magnesium  c potassium  d sodium      32 a newspaper article claims that carbon dioxide is formed as follows.    1 during respiration  2 when calcium carbonate reacts with hydrochloric acid  3 when methane burns in air    which statements are correct?  a 1, 2 and 3  b 1 and 2 only  c 1 and 3 only  d 2 and 3 only     33 the diagram shows an experiment.    damp litmus paper mixture of ammonium chloride and sodium hydroxidegas given off heat    what is the name of the gas and the final colour of the litmus paper?     gas colour  a ammonia blue  b ammonia red  c chlorine white  d chlorine red     ",
            "14": "14    \u00a9 ucles 2006 0620/01/m/j/06 34 the diagram shows the ph values of the soil in x and y, two parts of the garden of a house.    ph 7.0x ph 5.5y     the house owner wishes to use lime to neutralise the soil in one part of the garden.    to which part should the lime be added, and why?     part of garden because lime is  a x acidic  b x basic  c y acidic  d y basic     35 in the molecule shown, the two \u2013oh groups are numbered.    h c o oo h hh chh hchc 12     which of these \u2013oh groups react with aqueous sodium hydroxide?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "15": "15    \u00a9 ucles 2006  0620/01/m/j/06  [turn over  36 when a suitable catalyst is used, ethene reacts with steam.    what is the structure of the compound formed?    oo ho oo o h hcch c hhhchoha hc o hhhchohb hc hhccd      37 the diagram shows the separation of crude oil into fractions.    petrol x y z bitumencrude oil     what could x, y and z represent?     x y z  a diesel lubricating oil paraffin  b lubricating oil diesel paraffin  c lubricating oil paraffin diesel  d paraffin diesel lubricating oil     ",
            "16": "16    \u00a9 ucles 2006 0620/01/m/j/06 38 which of the compounds shown are used as fuels?    h c h hhchohhc hhhchh oo hh c hhc 12 3      1 2 3  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0013     39 which set of diagrams shows three substances that are all in the same homologous series?    a bcdhh hhhh cc hhcchh hh c hh c hoh hc oo h hh hcch hch hc co h hh o hcc hh c hh hh hch h c hhcc hhh hohh h cch hcc hhhcch hhh cchhhh      ",
            "17": "17    \u00a9 ucles 2006  0620/01/m/j/06  [turn over  40 the diagram shows the structure of a small molecule.    ch3 hh hcc     which chain-like molecule is formed when these small molecules link together?    cc ccch3 ch3ch3 ch3h hhha cc ccch3 hch3 hhhhhb cc ccch3 ch3ch3 ch3 ch3 ch3ch3 ch3c cc ccch3 ch3ch3 ch3h hhhd        ",
            "18": "18     0620/01/m/j/06 blank page",
            "19": "19     0620/01/m/j/06   blank page",
            "20": "20      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.     0620/01/m/j/06  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s06_qp_2.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry  0620/02         paper 2    may/june 2006        1 hour 15 minutes     candidates answer on the question paper.     no additional materials are required.                                read these instructions first      write your centre number, candidate number and name in the spaces at the top of this page.   write in dark blue or black pen.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   a copy of the periodic table is printed on page 16.     at the end of the examination, fasten all your work securely together.   the number of marks is given in brackets [  ] at the end of each question or part question.                           for examiner\u2019s use   1    2    3    4    5    6    total     this document consists of 15 printed pages and 1 blank page.  ib06 06_0620_02/4rp   \uf6d9 ucles  2006  [turn over",
            "2": "2  \u00a9 ucles 2006 0620/02/m/j//06  for  examiner's  use 1 the diagram shows models of various elements.    b e dac      (a) define the term element.      [1]       (b) which one  of the models a to e represents a solid containing diatomic molecules?   [1]      (c) which two of the models a to e represent gases?   and  [1]       (d) (i) which one  of the models a to e represents diamond?   [1]     (ii) state the name of the element present in diamond.   [1]     (iii) state a use of diamond other than in jewellery.   [1]   ",
            "3": "3  \u00a9 ucles 2006 0620/02/m/j//06 [turn over  for  examiner's  use  (e) structure e is a metal.  state three  physical properties which are characteristic of all  metals.       [3]      (f) metals are sometimes mixed with other elements in order to change their properties.     (i) what is the name given to a mixture of metals with other elements?   [1]     (ii) match up the metals in the boxes on the left with their uses on the right.  the first one has been done for you.    for making chemical plants for plating tin cans for car bodies for electrical wiring in houses for aircraft bodiestin mild steel stainless steel aluminium copper      [4]    ",
            "4": "4  \u00a9 ucles 2006 0620/02/m/j//06  for  examiner's  use 2 the diagram shows a biogas digester.  animal and vegetable waste is fermented by  bacteria.  the gas produced is a mixture of mainly carbon dioxide and methane.    gasgas out gas holder animal and vegetablewastesolid residue fermentationchamber      (a) state the name given to the energy-releasing process in which organisms use food and produce carbon dioxide.   [1]     (b) hydrogen is also produced during the fermentation.   the hydrogen reacts with the carbon dioxide to form methane and oxygen.   (i) complete the equation for this reaction.    co 2   +   2h 2    +      [2]   (ii) suggest a use for the methane produced in this reaction.   [1]    (iii) describe the arrangement and motion of the molecules in methane gas.  arrangement   motion  [2]     (iv) state the name of the homologous series to which methane belongs.   [1]     (v) which one of the following compounds belongs to the same homologous series as  methane?   tick one box.    c2h4 c2h6 ch 3oh ch 3co 2h    [1] ",
            "5": "5  \u00a9 ucles 2006 0620/02/m/j//06 [turn over  for  examiner's  use  (c) which one  of the following equations a, b, c or d describes fermentation?    ach 4   +   h 2o co   +   3h 2 bc6h12o6   +   6o 2 6h2o   +   6co 2 cc6h12o6 2c2h5oh   +   2co 2 dc6h14 c4h10   +   c 2h4     [1]       (d) many of the reactions occurring in the biogas digester are catalysed by enzymes.     (i) suggest where the enzymes come from.   [1]     (ii) define the term catalysis .   [1]      (e) the solid residue from the biogas digester can be used as a fertiliser.   state the names of two non-metallic elements found in fertilisers which are needed for  plant growth.   and  [2]  ",
            "6": "6  \u00a9 ucles 2006 0620/02/m/j//06  for  examiner's  use 3 the electronic structures of various atoms are shown below.    ab dec      (a) (i)  which one of these structures a to e represents a noble gas?   [1]    (ii) which two of these structures represent atoms from the same group of the  periodic table?   and  [1]     (iii) which one  of these structures represents an atom with an atomic number of 8?   [1]     (iv) which one  of these structures forms a stable ion by gaining one electron?   [1]    (v) which one  of these structures is in period 3 of the periodic table?   [1]   ",
            "7": "7  \u00a9 ucles 2006 0620/02/m/j//06 [turn over  for  examiner's  use  (b) complete the following sentences using words from the list.    chlorine    diamond     high      low sharing  sodium strong  transfer  weak       covalent bonds are formed by the   of pairs of electrons.  simple  covalent molecules such as   and bromine have   melting points.  giant covalent structures such as  have many   bonds and have high melting points. [5]     (c) the simplest covalent molecule is hydrogen.     (i) draw a diagram to show how the electrons are arranged in a hydrogen molecule.                   [1]   (ii) describe a test for hydrogen.  test   result  [2]     ",
            "8": "8  \u00a9 ucles 2006 0620/02/m/j//06  for  examiner's  use 4 coal gas is made by heating coal in the absence of air.   the table shows the composition of coal gas.    name of gas % of gas in coal gas  hydrogen 50  methane 30  carbon monoxide 7  carbon dioxide 4  nitrogen 4  ethene 3  oxygen 2     (a) (i)  which element in this table is a highly flammable gas?   [1]     (ii) which compound in the table is an alkene?   [1]    (iii) which compound in the table turns limewater milky?   [1]      (b) describe a test you can use to distinguish between ethene and methane.  test   result with ethene   result with methane  [3]     ",
            "9": "9  \u00a9 ucles 2006 0620/02/m/j//06 [turn over  for  examiner's  use  (c) molecules of ethene can react with each other to make poly(ethene).     (i) what is the name given to this type of reaction?   [1]     (ii) which formula below best represents a molecule of poly(ethene)?   tick one box.    cc hh hh ncc hh hch3 ncchh ncc hh hh      [1]     (d) ethene can be manufactured by breaking down hydrocarbons into smaller molecules  using high temperatures and a catalyst.   state the name given to this type of reaction.   [1]     (e) a liquid is also formed when coal is heated in the absence of air.   this liquid contains a high percentage of ammonia.    (i) describe a test for ammonia.  test   result  [2]     (ii) ammonia has the formula nh 3.   calculate the relative molecular mass of ammonia.            [1]   (f) coal contains a small amount of sulphur.   explain why burning coal is harmful to the environment.       [2]   ",
            "10": "10  \u00a9 ucles 2006 0620/02/m/j//06  for  examiner's  use 5 the diagram shows a cross section of a soil.    decaying leaves topsoil subsoil limestone      (a) a student took 10  g of topsoil and shook it with 200  cm3 of distilled water.     (i) how can the student separate the solids in the soil from the solution?   [1]     (ii) the topsoil had a ph of 6.   which of the following gives the best description of this ph?   tick one box.     strongly acidic       weakly acidic       neutral       weakly alkaline       [1] ",
            "11": "11  \u00a9 ucles 2006 0620/02/m/j//06 [turn over  for  examiner's  use  (b) the soil contained large amounts of calcium ions and carbonate ions.     (i) use the information in the diagram to suggest where these ions came from.   [1]     (ii) complete the word equation for the reaction of calcium carbonate with hydrochloric  acid.    calcium carbonate++hydrochloric acidcalcium chloride. .+.      [2]     (c) the table shows the mass of each ion present in 200  cm3 of soil solution.    ion formula of ion mass present/milligrams  calcium ca2+ 12  carbonate -2 3co  20  iron( iii) fe3+ 4  magnesium mg2+ 5  nitrate - 3no  2  phosphate -3 4po  1  others  6     (i) which negative ion has the highest concentration in the soil solution?   [1]     (ii) calculate the mass of iron( iii) ions in one litre (1000  cm3) of solution.         [1]     (iii) which ion in the table will release ammonia when heated with aqueous sodium  hydroxide and aluminium foil?   [1]     (iv) describe a test for iron( iii) ions.  test   result  [3]   ",
            "12": "12  \u00a9 ucles 2006 0620/02/m/j//06  for  examiner's  use  (d) the air trapped in the soil has a different composition from the air in the atmosphere.   the table shows the composition of the air in the soil.    gas percentage of gas in soil air  carbon dioxide 2  nitrogen 82  oxygen 15  other gases 1    state how the composition of soil air compares with the composition of air in the  atmosphere.  carbon dioxide   nitrogen   oxygen  [3]       (e) decaying leaves produce ethanoic acid.   complete the formula for ethanoic acid showing all atoms and bonds.    cc h hh     [1]   ",
            "13": "13  \u00a9 ucles 2006 0620/02/m/j//06 [turn over  for  examiner's  use 6 iron is extracted from iron ore by heating the iron ore with coke and limestone.     (a) state the name of the ore from which iron is extracted.   [1]       (b) the coke burns in a blast of hot air to form carbon monoxide.    (i) complete the equation for this reaction.    ..c   +   o 2 ..co    [1]    (ii) state an adverse effect of carbon monoxide on human health if it were to escape  from the blast furnace.   [1]      (c) near the top of the blast furnace, carbon monoxide reacts with iron ore.    fe2o3   +   3co 2fe   +   3co 2    (i) write a word equation for this reaction.         [1]     (ii) what type of chemical reaction is the conversion of fe 2o3 to 2fe?   [1]     ",
            "14": "14  \u00a9 ucles 2006 0620/02/m/j//06  for  examiner's  use  (d) the limestone is converted to calcium oxide and carbon dioxide by the intense heat in  the furnace.    caco 3 cao   +   co 2    (i) what type of chemical reaction is this?   [1]    (ii) name a use of limestone other than in the blast furnace.   [1]     (iii) the calcium oxide reacts with silica and alumina in the iron ore.   the product of this reaction collects on top of the molten iron at the bottom of the  furnace.  what is the name of this product?   put a ring around the correct answer.    bauxite   sand   slag  slaked lime     [1]    (e) the iron obtained from the blast furnace contains the following impurities.    carbon   manganese  phosphorus   silicon     (i) which one  of these elements is a transition element?   [1]    (ii) what type of oxide is phosphorus oxide?   put a ring around the correct answer.   acidic  amphoteric   basic   neutral    [1]    (iii) 50 tonnes of impure cast iron from the blast furnace contains 47 tonnes of iron.   calculate the percentage of the impurities in the cast iron.             [1]    ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.   0620/02/m/j//06 blank page ",
            "16": "16  \u00a9 ucles 2006 0620/02/m/j//06  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s06_qp_3.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry  0620/03         paper 3    may/june 2006        1 hour 15 minutes     candidates answer on the question paper.     no additional materials are required.                                read these instructions first      write your centre number, candidate number and name in the spaces at the top of this page.   write in dark blue or black pen.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   a copy of the periodic table is printed on page 16.     at the end of the examination, fasten all your work securely together.   the number of marks is given in brackets [  ] at the end of each question or part question.                       for examiner\u2019s use   1    2    3    4    5    6    7    total     this document consists of 16 printed pages.  ib06 06_0620_03/4rp   \uf6d9 ucles 2006  [turn over  ",
            "2": "2  \u00a9 ucles 2006 0620/03/m/j/06 for  examiner's  use 1 iron is a transition element.    (a) which of the following statements about transition elements are correct?     tick three  boxes.    the metals are highly coloured e.g. yellow, green, blue.     the metals have low melting points.     their compounds are highly coloured.     their compounds are colourless.     the elements and their compounds are often used as catalysts.     they have more than one oxidation state.     [3]    (b) (i) in which period in the periodic table is iron to be found?   [1]   (ii) use the periodic table to work out the number of protons and the number of  neutrons in one atom of iron.  number of protons =   number of neutrons =  [1]    (c) iron is extracted in a blast furnace.  the list below gives some of the substances used  or formed in the extraction.    carbon monoxide  coke  iron ore limestone slag      (i) which  substance is a mineral containing largely calcium carbonate?   [1]     (ii) which  substance is formed when impurities in the ore react with calcium oxide?   [1]     (iii) which substance is also called hematite?   [1]  ",
            "3": "3  \u00a9 ucles 2006 0620/03/m/j/06 [turn over for  examiner's  use  (d) state two functions of the coke used in the blast furnace.     [2]       (e) most of the iron is converted into mild steel or stainless steel. give one use for each.  mild steel   stainless steel  [2]     ",
            "4": "4  \u00a9 ucles 2006 0620/03/m/j/06 for  examiner's  use 2 some reactions of metals w, x, y and z are given below.    metal  reaction with water  reaction with dilute  hydrochloric acid   w a few bubbles form slowly in cold  water. vigorous reaction. gas given off.  x vigorous reaction.  metal melts.  gas given off. explosive reaction. should not  be attempted.  y no reaction. no reaction.  z does not react with cold water.  hot metal reacts with steam. steady fizzing.     (a) arrange  these metals in order of reactivity.  most reactive         least reactive  [2]       (b) which of these metals could be     (i) magnesium,   [1]     (ii) copper?   [1]   ",
            "5": "5  \u00a9 ucles 2006 0620/03/m/j/06 [turn over for  examiner's  use  (c) the equation for the reaction of x with cold water is given below.    2x(s) + 2h 2o(l)                2 xoh(aq) + h 2(g)     (i) describe  the test you would use to show that the gas evolved is hydrogen.     [1]     (ii) how could you show that the water contained a compound of the type xoh?     [2]      (iii) in which group of the periodic table does metal x belong?   [1]     (iv) the ore of x is its chloride.  suggest how metal x could be extracted from its  chloride.   [2]   ",
            "6": "6  \u00a9 ucles 2006 0620/03/m/j/06 for  examiner's  use 3 (a) four bottles were known to contain aqueous ammonia, dilute hydrochloric acid, sodium  hydroxide solution and vinegar, which is dilute ethanoic acid.  the bottles had lost their labels.  the ph values of the four solutions were 1, 4, 10 and 13.    complete the table.    solution ph  aqueous ammonia   dilute hydrochloric acid   sodium hydroxide solution   vinegar    [2]     (b) the following apparatus was set up to investigate the electrical conductivity of dilute  acids.    +_ carbon anodebulb/lamp carboncathode dilute sulphuric acid bubbles ofoxygen gasbubbles ofhydrogen gas       dilute sulphuric acid is a strong acid. if it was replaced by a weak acid, what two  differences in the observations would you expect to make?       [2]     (c) when nitric acid is added to water the following reaction occurs.    hno 3 + h 2o  - 3no  +     h 3o+    give the name and the formula of the particle which is transferred from nitric acid to  water.  name   formula  [2]  ",
            "7": "7  \u00a9 ucles 2006 0620/03/m/j/06 [turn over for  examiner's  use  (d) this question is concerned with the following oxides.    aluminium oxide al2o3  calcium oxide cao  carbon dioxide co 2  carbon monoxide co  magnesium oxide mgo  sulphur dioxide so 2       (i) which of the above oxides will react with hydrochloric acid but not with aqueous sodium hydroxide?   [1]     (ii) which of the above oxides will react with aqueous sodium hydroxide but not with hydrochloric acid?   [1]     (iii) which of the above oxides will react both with hydrochloric acid and with aqueous sodium hydroxide?   [1]      (iv) which of the above oxides will react neither with hydrochloric acid nor with  aqueous sodium hydroxide?   [1]    ",
            "8": "8  \u00a9 ucles 2006 0620/03/m/j/06 for  examiner's  use 4 the first three elements in group iv are   carbon,   silicon,  germanium.    (a) the element germanium has a diamond-type structure.  describe the structure of  germanium.  a diagram is acceptable.                [2]       (b) unlike diamond, graphite is soft and is a good conductor of electricity.    (i) explain why graphite has these properties.       [3]     (ii) give a use of graphite that depends on one of these properties.  property   use  [1]       (c) carbon dioxide and silicon( iv) oxide have similar formulae but different types of  structure.     (i) give the formulae of these oxides.   [1]    (ii) how are their structures different?     [2]     (d) all these elements form compounds with hydrogen called hydrides.  the saturated hydrides of carbon are the alkanes.  predict the formula of the hydride of germanium  which contains two germanium atoms.   [1]  ",
            "9": "9  \u00a9 ucles 2006 0620/03/m/j/06 [turn over for  examiner's  use 5 sulphuric acid is made by the contact process in the following sequence of reactions.    sulphur  sulphur dioxide  sulphur trioxide   sulphuric acid      (a) (i) how is sulphur dioxide made from sulphur?   [1]    (ii) sulphur dioxide has other uses.   why is it used in the manufacture of paper?   [1]    (iii) how does it preserve food?   [1]    (b) the equation for a stage of the contact process is    2so 2 + o 2   2so 3    the percentage of sulphur trioxide in the equilibrium mixture varies with temperature.    percentage of  sulphur trioxide temperature    (i) how does the percentage of sulphur trioxide in the equilibrium mixture vary as the  temperature increases?  circle the correct answer.    increases  stays the same  decreases  [1]     (ii) is the forward reaction in the equilibrium 2so 2 + o 2   2 s o 3 exothermic or  endothermic?  give a reason for your choice.     [2]   ",
            "10": "10  \u00a9 ucles 2006 0620/03/m/j/06 for  examiner's  use  (iii) explain, mentioning both rate and percentage yield, why the temperature used in  the contact process is 450\u00b0c.     [2]     (iv) describe how the sulphur trioxide is changed into concentrated sulphuric acid.     [2]     ",
            "11": "11  \u00a9 ucles 2006 0620/03/m/j/06 [turn over for  examiner's  use 6 (a) exothermic reactions produce heat energy.     an important fuel is methane, natural gas. the equation for its combustion is as follows.   ch 4 + 2o 2                      co 2 + 2h 2o    (i) in chemical reactions bonds are broken and new bonds are formed.   using this reaction give an example of  a bond that is broken,   a bond that is formed.  [2]     (ii) explain, using the idea of bonds forming and breaking, why this reaction is exothermic, that is it produces heat energy.     [2]      (b) some radioactive isotopes are used as nuclear fuels.     (i) give the symbol and the nucleon number of an isotope that is used as a nuclear  fuel.   [2]     (ii) give another use of radioactive isotopes.   [1]   ",
            "12": "12  \u00a9 ucles 2006 0620/03/m/j/06 for  examiner's  use  (c) cell reactions are both exothermic and redox.  they produce electrical energy as well  as heat energy.    (i) the diagram shows a simple cell.    v zinc electrode becomesthinnerironelectrode bubbles of hydrogen form dilutesulphuric acidvoltmeter      which substance in this cell is the reductant and which ion is the oxidant?  reductant   oxidant  [2]     (ii) how could the voltage of this cell be increased?   [1]     (iii) what is the important large scale use, relating to iron and steel, of this type of cell reaction?   [1]   ",
            "13": "13  \u00a9 ucles 2006 0620/03/m/j/06 [turn over for  examiner's  use  (d) cells can be set up with inert electrodes and the electrolytes as oxidant and reductant.    vvoltmeter carbon electrode(inert)carbonelectrode(inert) potassiummanganate( vii) (aq)potassiumiodide (aq) salt bridge(allows ions to move fromone beaker to another)electron flow      the potassium manganate( vii) is the oxidant and the potassium iodide is the reductant.    (i) describe the colour change that would be observed in the left hand beaker.   [2]    (ii) write an ionic equation for the reaction in the right hand beaker.   [2]    ",
            "14": "14  \u00a9 ucles 2006 0620/03/m/j/06 for  examiner's  use 7 the fractional distillation of crude oil usually produces large quantities of the heavier  fractions.  the market demand is for the lighter fractions and for the more reactive alkenes.   the heavier fractions are cracked to form smaller alkanes and alkenes as in the following example.   c 8h18  c 4h10 + c 4h8   octane   butane   butenes    (a) (i)  write a different equation for the cracking of octane.    c 8h18  +  [1]     (ii) the cracking of octane can produce isomers with the molecular formula c 4h8.   draw the structural formulae of two of these isomers.                [2]    (b) (i) give the essential condition for the reaction between chlorine and butane.   [1]    (ii) what type of reaction is this?   [1]    (iii) this reaction produces a mixture of products.  give the names of two products  that contain four carbon atoms per molecule.   and  [2]    ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.    \u00a9 ucles 2006 0620/03/m/j/06  for  examiner's  use  (c) alkenes are more reactive than alkanes and are used to make a range of organic chemicals.  propene, ch 3\u2013ch=ch 2, is made by cracking.  give the structural formula  of the addition product when propene reacts with the following.    (i) water           [1]   (ii) bromine           [1]   (d) propene reacts with hydrogen iodide to form 2  - iodopropane.  ch 3\u2212ch=ch 2 + hi  ch 3\u2212ch i\u2212ch 3    1.4  g of propene produced 4.0  g of 2  - iodopropane.    calculate the percentage yield.   moles of ch 3\u2013ch=ch 2 reacted =     maximum moles of ch 3\u2013ch i\u2013ch 3 that could be formed =      mass of one mole of ch 3\u2013ch i\u2013ch 3 = 170  g    maximum mass of 2  - iodopropane that could be formed =      percentage yield  % [4]    ",
            "16": "16  \u00a9 ucles 2006 0620/03/m/j/06 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s06_qp_5.pdf": {
            "1": "centre number candidate number name               cambridge international examinations    international general certificate of secondary education        chemistry  0620/05         paper 5  practical test    may/june 2006        1 hour 15 minutes     candidates answer on the question paper.     additional materials:  as listed in instructions to supervisors                                read these instructions first      write your name, centre number and candidate number in the spaces at the top of this page.   write in dark blue or black pen.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   practical notes are provided on page 8.     at the end of the examination, fasten all your work securely together.   the number of marks is given in brackets [  ] at the end of each question or part question.                                           for examiner\u2019s use   1    2    total     this document consists of 8 printed pages.  ib06 06_0620_05/5rp   \uf6d9 ucles  2006  [turn over  ",
            "2": "2  \u00a9 ucles 2006 0620/05/m/j/06 for  examiner's  use 1 you are going to investigate the speed of reaction when aqueous hydrogen peroxide  breaks down using a catalyst.  manganese( iv) oxide is the catalyst.  a catalyst remains  unchanged at the end of the reaction.     read all the instructions  below carefully before starting the experiments.       instructions     experiment 1     using a measuring cylinder, pour 20  cm3 of the hydrogen peroxide solution labelled a into  the conical flask.  fill the 50  cm3 measuring cylinder provided with water and set up the  apparatus as in the diagram below.  add one spatula measure of manganese( iv) oxide to  the conical flask, quickly put the bung in the flask and start your timer.     measure the volume of gas collected in the measuring cylinder at 10 seconds and at   20 seconds and record the results in the table opposite.   pour away the contents of the conical flask and rinse the flask with distilled water.    clampclamprubber connector 20  cm3 hydrogen peroxide solutioninverted measuringcylinder water trough       experiment 2     using the measuring cylinder, pour 15  cm3 of the solution a of aqueous hydrogen peroxide  into the conical flask.  now add 5  cm3 of distilled water to the flask.  set up the apparatus as  in experiment 1.  repeat the instructions as given for experiment 1, adding one spatula  measure of manganese( iv) oxide to the flask and measuring the volume of gas given off at  10 seconds and 20 seconds.  record your results in the table.      experiment 3     repeat experiment 1 using 10  cm3 of solution a and 10  cm3 of distilled water.  record your  results in the table.      experiment 4      repeat experiment 1 using 5  cm3 of solution a and 15  cm3 of distilled water.  record your  results in the table. ",
            "3": "3  \u00a9 ucles 2006 0620/05/m/j/06 [turn over  for  examiner's  use  table of results     experiment volume of gas collected after 10  seconds / cm3 volume of gas collected after 20  seconds / cm3  1    2    3    4       [5]       (a) plot your results on the grid for each experiment.  draw 4 graphs.  label each line clearly with the number of the experiment.    10 time  / svolume of gas given off  / cm3 20050 40302010 0    [4]     (b) describe the appearance of the mixture in the conical flask as you timed the reaction.     [1]     ",
            "4": "4  \u00a9 ucles 2006 0620/05/m/j/06 for  examiner's  use  (c) (i)  which experiment has the fastest rate of reaction?   [1]     (ii) explain, in terms of particles, why this experiment has the fastest rate.       [2]      (d) (i)  state two sources of error in the experiments.  1     2    [2]     (ii) suggest two improvements to reduce the sources of error in the experiments.  1     2    [2]       (e) state a practical method you could use to prove that manganese( iv) oxide was a  catalyst in experiment 1.       [2]   ",
            "5": "5  \u00a9 ucles 2006 0620/05/m/j/06 [turn over  for  examiner's  use experiment 5      to a few cm3 of solution a in a test-tube, add a spatula measure of manganese( iv) oxide.     test the gas given off by using a splint.  test   observation  [2]     identify the gas.   [1]     ",
            "6": "6  \u00a9 ucles 2006 0620/05/m/j/06 for  examiner's  use 2 you are provided with a mixture of two compounds, b and c, each containing the same  metal cation.  compound b is soluble in water and compound c is insoluble.   carry out the following tests on the mixture, recording all of your observations in the table.   do not write any conclusions in the table.    tests observations      [1]  (a) describe the appearance of the  mixture.         [2]  (b) place one spatula measure of  the mixture into a hard glass  test-tube.   heat gently then strongly.  test any gases released with  cobalt chloride paper. note all observations.   add the rest of the mixture to a boiling tube.  add about 25  cm3 of distilled water and shake for two minutes.  filter the  mixture into a small beaker and retain both the filtrate and the residue.  tests on the filtrate    pour about 2  cm depth of the solution into each of four test-tubes.         [3]  (c) (i) by using a teat pipette, add  drops of aqueous sodium  hydroxide to the first portion of the solution.     now add excess aqueous  sodium hydroxide to the  test-tube.         [2]  (ii) take the second portion  and repeat test (c)(i)  using  aqueous ammonia instead  of aqueous sodium  hydroxide.  ",
            "7": "7  \u00a9 ucles 2006 0620/05/m/j/06 for  examiner's  use  tests observations   [1] (iii) to the third portion of the  solution add a few drops of hydrochloric acid and about 1  cm3 of barium nitrate  solution.   [1] (iv) to the fourth portion of the  solution add a few drops of  nitric acid and about 1  cm3  of silver nitrate solution.  tests on the residue        [2]  (d) by using a spatula, transfer  some of the residue from the  filter paper into a test-tube.  add hydrochloric acid to the test-tube and test the gas with limewater.      (e) what does test (b) indicate?   [1]      (f) what do tests (c)(iii)  and (iv)  tell you about b?     [2]       (g) what conclusions can you draw about  compound b,     compound c?    [3]     ",
            "8": "8    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.   0620/05/m/j/06 notes for use in qualitative analysis     tests for anions     anion test test result  carbonate (co_ 2 3) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous lead( ii) nitrate yellow ppt.  nitrate (no\u2212 3)  [in solution] add aqueous sodium hydroxide, then aluminium foil; warm carefully ammonia produced  sulphate (so_ 2 4)  [in solution] acidify, then add aqueous barium  nitrate white ppt.    tests for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh+ 4) ammonia produced on warming -  calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution    tests for gases     gas test and test result  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_s06_qp_6.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry  0620/06         paper 6  alternative to practical    may/june 2006        1 hour    candidates answer on the question paper.     no additional materials are required.                        read these instructions first      write your name, centre number and candidate number at the top of this page.   write in dark blue or black pen.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.     at the end of the examination, fasten all your work securely together.   the number of marks is given in brackets [  ] at the end of each question or part question.                             for examiner\u2019s use   1    2    3    4    5    6    total       this document consists of 14 printed pages and 2 blank pages.  ib06 06_0620_06/5rp   \uf6d9 ucles 2006  [turn over  ",
            "2": "2  \u00a9 ucles 2006 0620/06/m/j/06 for  examiner's  use 1 the diagram shows the effect of passing electricity through concentrated hydrochloric acid.    +\u2013chlorine hydrogen      (a) label the diagram by completing the boxes. [3]       (b) name this process.   [1]      (c) give a test for chlorine.  test   result  [2]     ",
            "3": "3  \u00a9 ucles 2006 0620/06/m/j/06 [turn over  for  examiner's  use 2 a sample of orange fruit jam was investigated to check the three colourings present.    step 1 the jam was boiled with water.  step 2 the mixture was filtered.  step 3 the filtrate was concentrated.  step 4 the concentrate was analysed by chromatography.       (a) what was the purpose of step 1?   [1]      (b) why was the mixture filtered?   [1]     (c) how was step 3 carried out?   [1]     (d) draw a diagram to show the possible paper chromatogram obtained in step 4.                   [2]     ",
            "4": "4  \u00a9 ucles 2006 0620/06/m/j/06 for  examiner's  use 3 a student carried out an experiment to meas ure the temperature changes during the  reaction of two solutions x and y.     the instructions were as follows.     leave the solutions to stand in the laboratory for one hour.     pour 25 cm3 of solution x into a polystyrene cup and record its temperature.     add 10 cm3 of solution y and record the maximum temperature reached.     repeat the experiment using 25 cm3 of solution x with different volumes of solution y.     the results are shown in the table.  use the thermometer diagrams to record the maximum  temperatures reached.    volume of solution y added to 25  cm3 solution x  / cm3maximum temperature  / octhermometer diagram 0 10 20 30 40 5055 5045 454035504540302520 403530 504540    [2]   ",
            "5": "5  \u00a9 ucles 2006 0620/06/m/j/06 [turn over  for  examiner's  use  (a) why were the solutions left standing in the laboratory for about one hour before the  experiment?     [1]       (b) what was the temperature in the laboratory?   [1]      (c) why were the reactions carried out in a polystyrene cup rather than a glass container?   [1]      (d) plot the results on the grid.  draw two straight  lines through the points, one for the  increasing temperatures and one for the decreasing temperatures.    0 1 02 03 04 05 0 volume of solution y added  / cm3maximum temperature  / oc60 5040302010 0    [3]   ",
            "6": "6  \u00a9 ucles 2006 0620/06/m/j/06 for  examiner's  use  (e) (i) read from your graph the maximum temperature that could be reached in the  reaction.   [1]    (ii) indicate on the graph where the two solutions completely react with each other. [1]    (iii) what volume of solution y exactly reacts with the 25 cm 3 of solution x?   [1]      (f) circle which word correctly describes this chemical reaction.    endothermic  reversible  exothermic  [1]    ",
            "7": "7  \u00a9 ucles 2006 0620/06/m/j/06 [turn over  for  examiner's  use 4 a student investigates the speed of reaction when aqueous hydrogen peroxide breaks  down using a catalyst, manganese( iv) oxide.  the catalyst remains unchanged at the end  of the reaction.   the apparatus was set up as shown in the diagram.    clampclamprubber connector 20  cm3 hydrogen peroxide solutioninverted measuringcylinder water trough      experiment 1      by using a measuring cylinder, 20  cm3 of hydrogen peroxide solution was poured into a  conical flask.  one spatula measure of manganese( iv) oxide was added to the flask, the  bung was quickly put in the flask and the timer started.   the volume of gas collected in the measuring cylinder at 10 seconds, 20 seconds and 30  seconds was measured.   the results are shown in the table below.   measuring cylinder diagram volume of gas in measuring cylinder  / cm30 time  / s1 0 20 30 10 20 30405010 20 30405010 20 30405010 20 304050 01 9 3 9 5 1      ",
            "8": "8  \u00a9 ucles 2006 0620/06/m/j/06 for  examiner's  use experiment 2      by using a measuring cylinder 15  cm3 of hydrogen peroxide was poured into the conical  flask.  the instructions were repeated exactly as given for experiment 1, but 5  cm3 of  distilled water was also added to the flask.   use the diagrams to record your results in the table below.   measuring cylinder diagram volume of gas in measuring cylinder  / cm30 time  / s1 0 20 30 10 20 30405010 20 30405010 20 30405010 20 304050      [2]     experiment 3     experiment 1 was repeated using 10  cm3 of hydrogen peroxide and 10  cm3 of distilled  water.  record your results in the table.    measuring cylinder diagram volume of gas in measuring cylinder  / cm30 time  / s1 0 20 30 10 20 3010 20 3010 20 3010 20 30      [2] ",
            "9": "9  \u00a9 ucles 2006 0620/06/m/j/06 [turn over  for  examiner's  use experiment 4      experiment 1 was repeated using 5  cm3 of hydrogen peroxide and 15  cm3 of distilled water.    record your results in the table.    measuring cylinder diagram volume of gas in measuring cylinder  / cm30 time  / s1 0 20 30 10 20 3010 20 3010 20 3010 20 30      [2]   ",
            "10": "10  \u00a9 ucles 2006 0620/06/m/j/06 for  examiner's  use  (a) plot your results on the grid for each experiment.  draw 4 graphs and label each  clearly with the number of the experiment.    60 5040302010 10 20 30 0 time  / secondsvolume of gas  / cm3    [5]     (b) (i)  which experiment has the fastest rate of reaction?   [1]     (ii) explain, in terms of particles, why this experiment has the fastest rate.       [2]     ",
            "11": "11  \u00a9 ucles 2006 0620/06/m/j/06 [turn over  for  examiner's  use  (c) (i)  state two sources of error in the experiments.  1     2    [2]     (ii) suggest two improvements to reduce the sources of error in the experiments.  1     2    [2]       (d) state a practical method you could use to prove that manganese( iv) oxide was a  catalyst in experiment 1.       [2]     ",
            "12": "12  \u00a9 ucles 2006 0620/06/m/j/06 for  examiner's  use 5 a mixture of two compounds, b and c, was tested.   compound b was a water-soluble zinc salt and compound c was insoluble.   the tests and some of the observations are in the following table.   complete the observations in the table.   tests  observations    (a) one measure of the mixture was heated gently then strongly.         the gas released was tested  with cobalt chloride paper. condensation at the top of the tube       paper turned pink   the rest of the mixture was added to  about 25 cm3 of distilled water in a  boiling tube.  the contents of the tube were shaken and filtered. the following tests were carried out.  tests on the filtrate   the solution was divided into 2 cm3 portions in four test-tubes.         [3]  (b) (i) drops of aqueous sodium hydroxide were added to the first portion of the  solution.       excess aqueous sodium  hydroxide was added.           [3]    (ii) using the second portion  test (b)(i)  was repeated  using aqueous ammonia instead of aqueous sodium hydroxide.  white precipitate  (iii) to the third portion of solution was added hydrochloric acid and barium nitrate solution. ",
            "13": "13  \u00a9 ucles 2006 0620/06/m/j/06 [turn over  for  examiner's  use  tests  observations    (iv) to the fourth portion of  solution was added nitric  acid and silver nitrate solution. no visible reaction  tests on the residue    rapid effervescence  (c) some of the residue was placed  into a test-tube.  dilute  hydrochloric acid was added  and the gas given off was tested with limewater.  limewater turned milky     (d) what does test (a) indicate?   [1]       (e) what conclusions can you draw about compound b?     [2]       (f) what does test (c) indicate?     [2]     ",
            "14": "14  \u00a9 ucles 2006 0620/06/m/j/06 for  examiner's  use 6 the diagram shows two bottles of liquid oven cleaner.         the oven cleaners contain sodium hydroxide solution.  plan an investigation to show which  oven cleaner contains the highest concentration of sodium hydroxide.                 [6]     ",
            "15": "15   0620/06/m/j/06 blank page",
            "16": "16    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.   0620/06/m/j/06 blank page  "
        },
        "0620_w06_qp_1.pdf": {
            "1": "       university of cambridge international examinations    international general certificate of secondary education        chemistry 0620/01        paper 1  multiple choice     october/november 2006        45 minutes     additional materials: multiple choice answer sheet      soft clean eraser      soft pencil (type b or hb is recommended)                          read these instructions first     write in soft pencil.    do not use staples, paper clips, highlighters, glue or correction fluid.   write your name, centre number and candidate number on the answer sheet in the spaces provided unless   this has been done for you.      there are forty  questions on this paper. answer all questions. for each question there are four possible    answers  a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.     read the instructions on the answer sheet very carefully.     each correct answer will score one mark. a mark will not be deducted for a wrong answer.   any rough working should be done in this booklet.   a copy of the periodic table is printed on page 16.  you may use a calculator.                                              this document consists of 16 printed pages.  ib06 11_0620_01/2rp   \uf6d9 ucles 2006  [turn over  ",
            "2": "2    \uf6d9 ucles 2006 0620/01/o/n/06 1 in which change of state do the particles become more widely separated?  a gas to liquid  b gas to solid  c liquid to gas  d liquid to solid      2 a student mixes 25  cm3 samples of dilute hydrochloric acid with different volumes of aqueous  sodium hydroxide. each time, the student measures the change in temperature.    which piece of apparatus is not needed?    clock thermometer beaker measuring cylinderbd ac      3 which piece of apparatus should be used for the accurate  measurement of 30.0  cm3 of a liquid?  a a beaker  b a burette  c a conical flask  d a measuring cylinder    4 which number is different for isotopes of the same element?  a number of electrons  b number of full shells  c number of nucleons  d number of protons    ",
            "3": "3    \uf6d9 ucles 2006 0620/01/o/n/06  [turn over  5 the table shows the nucleon numbers and proton numbers of some atoms.    nucleon number 35 37 40 39 40  proton number 17 17 18 19 19    how many are atoms of non-metallic elements?  a 1 b 2 c 3 d 4      6 the table shows the electronic structures of four atoms.    atom electronic structure  w 2,1  x 2,7  y 2,8,4  z 2,8,8    which two atoms combine to form an ionic compound?  a w and x b w and y c x and y d x and z      7 element x forms an acidic, covalent oxide.   which row in the table shows how many electrons there could be in the outer shell of an atom of x?     1 2 6 7  a \u0013 \u0017 \u0017 \u0017  b \u0013 \u0013 \u0017 \u0017  c \u0017 \u0017 \u0017 \u0013  d \u0017 \u0017 \u0013 \u0013      8 which atom has twice as many neutrons as protons?  a h1 1 b h2 1 c h3 1 d he4 2     ",
            "4": "4    \uf6d9 ucles 2006 0620/01/o/n/06 9 magnesium and sulphur each form a chloride.    what could be the formulae of these chlorides?     magnesium sulphur  a mg 2cl s 2cl  b mg 2cl scl 2  c mgc l2 s 2cl  d mgc l2 scl 2     10 a gas has the molecular formula noc l.    which diagram could show molecules of the pure gas noc l  ?    a b c dkey cl no      ",
            "5": "5    \uf6d9 ucles 2006 0620/01/o/n/06  [turn over  11 the electrolysis of concentrated aqueous sodium chloride makes three products.    which products are shown at the correct electrodes?     anode (+ve) cathode (\u2013ve)  a chlorine sodium hydroxide  b sodium hydroxide chlorine  c hydrogen sodium  d sodium hydrogen     12 aluminium is extracted from its oxide by electrolysis. to do so, the oxide is dissolved.    which substance is used to dissolve aluminium oxide and where is aluminium deposited during the electrolysis?     substance used to  dissolve aluminium oxide where aluminium is  deposited  a cryolite anode (+ve)  b cryolite cathode (\u2013ve)  c water anode (+ve)  d water cathode (\u2013ve)     13 which piece of apparatus is essential to measure the speed of a reaction?  a accurate balance  b gas syringe  c stopwatch  d thermometer    ",
            "6": "6    \uf6d9 ucles 2006 0620/01/o/n/06 14 equations for two changes p and q are shown.    p h 2o(s) \u2192 h 2o(l)  q ch 4(g) + 2o 2(g) \u2192 co 2(g) + 2h 2o(l)    which of these changes are exothermic?     p q  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     15 the decomposition of glucose, in aqueous solution, to form ethanol and carbon dioxide is  catalysed by an enzyme in yeast.    which change increases the rate of this decomposition?  a add more water to the solution  b cool the solution  c heat the solution to boiling point  d heat the solution to 30  \u00b0c     16 which equation shows an oxidation reaction?  a c + o 2 \u2192 co 2  b caco 3 \u2192 cao + co 2  c 2h2o2 \u2192 2h 2o + o 2  d n2o4 \u2192 2no 2     17 acids react with bases, carbonates and metals.    which of these reactions produce a gas?    reaction of acid with a    base  carbonate metal  a \u0013 \u0013 \u0013  b \u0013 \u0017 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017   ",
            "7": "7    \uf6d9 ucles 2006 0620/01/o/n/06  [turn over  18 which properties does an acid have?    1 reacts with ammonium sulphate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     19 the diagrams show two experiments, one to make barium chloride and the other to make barium  sulphate.    dilute hydrochloric acid aqueous barium hydroxidedilute sulphuric acid aqueous barium hydroxide     in each experiment, the acid is run into the conical flask until the resulting liquid has ph7.    what are the next steps to obtain samples of the solid salts?     barium chloride barium sulphate  a crystallisation crystallisation  b crystallisation filtration  c filtration crystallisation  d filtration filtration     ",
            "8": "8    \uf6d9 ucles 2006 0620/01/o/n/06 20 which piece of equipment can be used to show that a gas is hydrogen?    damp litmus paper splint splintabcd flame glowing limewater       21 the statements are about metals and their oxides.    metals \u2026x\u2026 electrons to form ions. the oxides of metals are \u2026y\u2026.    which words correctly complete the statements?     x y  a gain acidic  b gain basic  c lose acidic  d lose basic     22 the diagram shows one stage in the manufacture of nitric acid from ammonia.    ammonia and airproductsheated platinum gauze     what could be the use of the platinum gauze in this process?  a as a base  b as a catalyst  c as a filter  d as a fuel     ",
            "9": "9    \uf6d9 ucles 2006 0620/01/o/n/06  [turn over  23 an element does not conduct electricity but  it does exist as diatomic molecules.    in which area of the periodic table is the element to be found?    bac d      24 which properties of helium explain its use in filling balloons?     low density its unreactivity  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      25 the diagram shows apparatus used to test the reactivity of calcium, copper and magnesium with  steam.    steam metal heatgas     which metals react with steam to form hydrogen?     calcium copper magnesium  a \u0013 \u0013 \u0017  b \u0013 \u0017 \u0013  c \u0017 \u0013 \u0017  d \u0017 \u0017 \u0013     ",
            "10": "10    \uf6d9 ucles 2006 0620/01/o/n/06 26 which types of steel are used in chemical plants and machinery?     chemical plant machinery  a mild steel mild steel  b mild steel stainless steel  c stainless steel mild steel  d stainless steel stainless steel     27 in separate experiments, mixtures of cuo/c and of mgo/c are strongly heated in the apparatus  shown.    heattube metal oxide and carbon limewater     what happens to the limewater in these experiments?     cuo/c mgo/c  a goes cloudy goes cloudy  b goes cloudy stays clear  c stays clear goes cloudy  d stays clear stays clear      28 which raw materials are used in the manufacture of iron?  a bauxite and lime  b bauxite and limestone  c hematite and lime  d hematite and limestone    ",
            "11": "11    \uf6d9 ucles 2006 0620/01/o/n/06  [turn over  29 the diagram represents the composition of dry air.    which part shows the percentage of nitrogen in the air?    a b c d      30 the diagram shows some uses of water in the home.    1 2 3    for which of these uses is it important for the water to have been purified?  a 1 only  b 2 only  c 3 only  d 1, 2 and 3     31 the listed pollutants are sometimes found in car exhaust fumes.    1 carbon monoxide  2 nitrogen oxides  3 sulphur dioxide    which of these pollutants are products of the combustion of the fuel?  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3 ",
            "12": "12    \uf6d9 ucles 2006 0620/01/o/n/06 32 a shopkeeper stores iron nails in an airtight container, as shown in the diagram.    tight lid plastic jar air iron nails     the nails begin to rust after a few days.    how can the rusting of the nails be prevented?  a leave the lid off  b put a drying agent in the jar  c put the jar in a warm place  d seal the jar in a bag      33 two uses of oxygen are    1 burning acetylene in welding,  2 helping the breathing of hospital patients.    which of these uses form carbon dioxide?     use 1 use 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "13": "13    \uf6d9 ucles 2006 0620/01/o/n/06  [turn over  34 the diagram shows a kiln used to heat limestone.    gas burners productairwaste gaseslimestone     what is the product and what waste gas is formed?     product waste gas  a lime carbon monoxide  b lime carbon dioxide  c slaked lime carbon monoxide  d slaked lime carbon dioxide     35 the structures of three compounds are shown.    ch3 ch3 ch2 ch3ch ch3 ch2 ch2ch ch3 c ch2 oho x y z    what are x , y and z?     x y z  a alkane alkene alcohol  b alkane alkene carboxylic acid  c alkene alkane alcohol  d alkene alkane carboxylic acid     ",
            "14": "14    \uf6d9 ucles 2006 0620/01/o/n/06 36 how many oxygen atoms and double bonds are there in one molecule of ethanoic acid?     number of oxygen atoms number of double bonds  a 1 0  b 1 1  c 2 0  d 2 1     37 compounds r and s occur naturally.    r is c 6h14 and s is c 6h12o6.    which of the terms hydrocarbon  and occurs in crude oil  describe r and s?     hydrocarbon occurs in crude oil  a r only r only  b r only s only  c s only r only  d s only s only     38 the diagram shows an ethane molecule.    hh hhhh cc     which compound has chemical properties similar to those of ethane?    h hhhh cc hh hc h hhhh cc oh h hh cc oo habcd cch hhh      ",
            "15": "15    \uf6d9 ucles 2006 0620/01/o/n/06  [turn over  39 the diagram shows the first four members of a homologous series.    hch hh hcc hh h hh hcc hh c hh h hh hcc hh c hh c hh h hh    what is the difference in molecular formula between one member and the next in the series?  a ch b ch 2 c ch 3 d ch 4     40 the diagram shows part of a polymer.    cc hh c hh c hh hh cc hh hh    which compound is used as the monomer?  a c2h4  b c2h6  c c6h12  d c6h14     ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.    \uf6d9 ucles 2006 0620/01/o/n/06 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w06_qp_2.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry  0620/02         paper 2    october/november 2006        1 hour 15 minutes     candidates answer on the question paper.     no additional materials required.                                read these instructions first      write your centre number, candidate number and name on all the work you hand in.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part questions.   a copy of the periodic table is printed on page 20.                       for examiner\u2019s use   1    2    3    4    5    6    7    total     this document consists of 18 printed pages and 2 blank pages.  ib06 11_0620_02/2rp   \uf6d9 ucles 2006  [turn over  ",
            "2": "2  \u00a9 ucles 2006 0620/02/o/n/06 for  examiner's  use 1 when group i elements react with water, hydrogen gas is given off.   the diagram shows the reaction of lithium, potassium and sodium with water.    abc     (a) which one  of these elements a, b or c is lithium?   [1]      (b) (i)  balance the equation for the reaction of sodium with water by completing the left- hand side.    ..na   +   ..h 2o 2naoh   +   h 2   [1]    (ii) apart from fizzing, describe two things that you would see when sodium reacts  with water.       [2]     (iii) after the sodium had reacted with the wate r, the solution was tested with red litmus  paper.   what colour did the litmus paper turn?   give a reason for your answer.  colour   reason  [2]   ",
            "3": "3  \u00a9 ucles 2006 0620/02/o/n/06 [turn over  for  examiner's  use  (iv) which of the following statements about sodium are true?   tick two boxes.    it is made by reducing sodium oxide with carbon.    it reacts with chlorine to form sodium chloride.    it reacts readily with oxygen.    it only conducts electricity when molten.     [2]      (c) rubidium also reacts with water.  how does the speed of reaction of rubidium with  water compare with that of potassium with water?   [1]      (d) sodium has only one stable isotope whereas potassium has several isotopes.    (i) what do you understand by the term isotopes ?     [1]     (ii) how many protons does sodium have in its nucleus?   use the periodic table to help you.   [1]     (iii) how many electrons are there in an atom of potassium?   [1]    (iv) uranium has many isotopes.  one of these is uranium-235 ( 235u).   what is the main use of this isotope of uranium?   [1]    ",
            "4": "4  \u00a9 ucles 2006 0620/02/o/n/06 for  examiner's  use 2 copper can be extracted by heating copper carbonate with carbon.     (a) the copper carbonate breaks down into copper oxide and releases a gas.   complete the equation for this reaction.    cuco 3 cuo   +    [1]     (b) the copper oxide then reacts with the carbon.    2cuo   +   c 2cu   +   co 2heat     (i) complete the following sentences using words from the list.  endothermic  exothermic  halogen  metal   neutralised oxidised  reduced     in this reaction copper oxide is  to copper.  the copper obtained is a pinkish-brown    the reaction is   because heat is absorbed. [3]     (ii) state the name of the substance which is oxidised during this reaction.   [1]     (iii) how would you test for the carbon dioxide given off in this reaction?  test   result  [2]       (c) describe a test for aqueous copper ions and state the result.       [3]     ",
            "5": "5  \u00a9 ucles 2006 0620/02/o/n/06 [turn over  for  examiner's  use  (d) carbon is in group iv of the periodic table.     (i) draw a diagram to show how the electrons are arranged in an atom of carbon.                    [1]   (ii) to which period in the periodic table does carbon belong?   [1]       (e) organic compounds contain carbon and hydrogen.    (i) to which homologous series does the organic compound a belong?    hh hchhch compound a      [1]     (ii) state the name of compound a.   [1]     ",
            "6": "6  \u00a9 ucles 2006 0620/02/o/n/06 for  examiner's  use 3 lavandulol is found in lavender plants.  the formula of lavandulol is shown below.    ch 2ch 3 ch 3 ch 2 ch 3cch ch 2 hocc h      (a) put a ring around the alcohol functional group in this formula.   [1]     (b) is lavandulol a saturated or unsaturated compound?   give a reason for your answer.     [1]      (c) state the names of the two products formed when lavandulol is burnt in excess oxygen.   and  [2]       (d) lavandulol can be extracted from lavender flowers by distillation using the apparatus shown below.  the lavandulol is carried off in small droplets with the steam.    heatlavender flowersand waterxa lavandulol water    ",
            "7": "7  \u00a9 ucles 2006 0620/02/o/n/06 [turn over  for  examiner's  use  (i) state the name of the piece of apparatus labelled a.   [1]     (ii) what is the temperature of the water at point x in the diagram?   [1]    (iii) the lavandulol and water are collected in the beaker.   what information in the diagram shows that lavandulol is less dense than water?   [1]       (e) lavender flowers contain a variety of different pigments (colourings).   a student separated these pigments using paper chromatography.  the results are shown in the diagram below.   chromatography paper     (i) put an x on this diagram to show where the mixture of pigments was placed at the start of the experiment.  [1]    (ii) how many different pigments have been separated?   [1]    (iii) draw a diagram to show how the chromatography apparatus was set up.   on your diagram label  \u007f the solvent  \u007f the origin line                      [1] ",
            "8": "8  \u00a9 ucles 2006 0620/02/o/n/06 for  examiner's  use  (iv) during chromatography, the solvent evaporates and then diffuses throughout the  chromatography jar.   what do you understand by the term diffusion ?     [1]     (v) ethanol can be used as a solvent in chromatography.   draw the formula for ethanol showing all atoms and bonds.             [1]   (vi) which of the following statements about ethanol are true?   tick two boxes.    it is a carboxylic acid.    it is a product of the fermentation of glucose.    it is an unsaturated compound.    it is formed by the catalytic addition of steam to ethene.   [1]    ",
            "9": "9  \u00a9 ucles 2006 0620/02/o/n/06 [turn over  for  examiner's  use 4 this question is about compounds.     (a) what do you understand by the term compound ?     [1]      (b) complete the table below to show the formulae and uses of some compounds.    compound  relative number of atoms present formula use  calcium oxide ca = 1  o = 1 cao     sodium chloride   na = 1  cl = 1  table salt  calcium carbonate ca = 1  c =1  o = 3          nh 4no 3 in fertilizers   [6]     (c) calculate the relative formula mass of nh 4no 3.             [1]     ",
            "10": "10  \u00a9 ucles 2006 0620/02/o/n/06 for  examiner's  use 5 the list shows part of the reactivity series.    strontium calciummagnesiumironcoppermore reactive less reactive      (a) calcium is manufactured by the electrolysis of molten calcium chloride.   suggest why calcium is extracted by electrolysis.   [1]     (b) equal sized pieces of magnesium, strontium and calcium are placed in water.  some  observations about these reactions are shown in the table.   complete the box for strontium.    metal  observations   magnesium gives off a few bubbles of gas with hot water. dissolves very slowly.  calcium gives off bubbles steadily with cold water. dissolves slowly.  strontium     [2]      (c) when water is added to calcium carbide, acetylene and calcium hydroxide are formed.   state a use for acetylene.   [1]     (d) a solution of calcium hydroxide is alkaline.     (i) complete and balance the equation for the reaction of calcium hydroxide with  hydrochloric acid.    ca(oh) 2   +   2hc l cac l2   +       [1]   (ii) what type of chemical reaction is this?   [1]   ",
            "11": "11  \u00a9 ucles 2006 0620/02/o/n/06 [turn over  for  examiner's  use  (e) a student used the apparatus shown below to calculate the concentration of a solution  of calcium hydroxide.    calcium hydroxide solutionhydrochloric acida      (i) state the name of the piece of apparatus labelled a.   [1]    (ii) describe how the ph of the solution in the flask changes as the hydrochloric acid is added.     [2]     ",
            "12": "12  \u00a9 ucles 2006 0620/02/o/n/06 for  examiner's  use 6 the diagram shows the structure of lead bromide.    pb2+pb2+ pb2+pb2+pb2+pb2+br\u2013br\u2013br\u2013br\u2013 br\u2013br\u2013br\u2013br\u2013 br\u2013br\u2013br\u2013br\u2013      (a) what is the simplest formula for lead bromide?   [1]      (b) what type of structure and bonding is present in lead bromide?   choose two words from the following:    atomic covalent giant ionic metallic molecular     [2]      (c) lead bromide is electrolysed using the apparatus shown below.    + \u2013 heatmolten lead bromideelectrodesb a c      (i) which letter, a, b or c represents the cathode?   [1]   ",
            "13": "13  \u00a9 ucles 2006 0620/02/o/n/06 [turn over  for  examiner's  use  (ii) state the name of a metal which can be used for the electrodes.   [1]     (iii) why does lead bromide have to be molten for electrolysis to occur?     [1]     (iv) state the name of the products formed during this electrolysis;  at the anode,   at the cathode.  [2]      (d) a student bubbled chlorine gas through an aqueous solution of sodium bromide.    (i) complete the equation for this reaction.    cl2    +    2nabr     +    2nacl chlorine sodium bromidebromine sodium chloride     [1]   (ii) what colour is the solution at the end of the reaction?   [1]    (iii) an aqueous solution of iodine does not react with a solution of sodium bromide.  explain why there is no reaction.     [1]   ",
            "14": "14  \u00a9 ucles 2006 0620/02/o/n/06 for  examiner's  use  (e) bromine becomes decolourised when it reacts with ethene.     (i) draw the structure of ethene showing all atoms and bonds.                [1]    (ii) which one of the following, a, b, c or d, shows the correct structure of the product  formed when bromine reacts with ethene?    hh hcbr hcb r ahhhhcbr hc chh hcbr br hc dhcbr br ch b     answer  [1]     ",
            "15": "15  \u00a9 ucles 2006 0620/02/o/n/06 [turn over  for  examiner's  use 7 the table gives some information about the properties of some metals.    metal  melting point /\u00b0c colour of chloride   a 1890 pink  b 98 white  c 63 white  d 1535 brownish-black     (a) which two of the metals a to d are transition metals?   give a reason for your answer.  metals   reason  [2]      (b) when iron powder reacts with warm sulphuric acid, hydrogen is given off.    fe   +   h 2so 4 feso 4   +   h 2     state the name of the salt made in this reaction.   [1]     ",
            "16": "16  \u00a9 ucles 2006 0620/02/o/n/06 for  examiner's  use  (c) a student used the apparatus shown below for investigating the speed of the reaction  between iron and sulphuric acid.    watersulphuric acid iron powder      describe how this apparatus can be used to investigate the speed of this reaction.         [3]      (d) the student repeated the experiment with different concentrations of sulphuric acid.   in each experiment the mass of iron powder was the same and the temperature was  kept at 30\u00b0c.   the results are shown in the table.   concentration of sulphuric  acid / moles per dm 3 speed of reaction /cm3  hydrogen per second  0.4 4.2  0.8 8.5  1.6 17.0    (i) use the information in the table to help you work out how the speed of the reaction is affected by the concentration of sulphuric acid.       [2]     (ii) what will happen to the speed of the reaction if lumps of iron are used instead of  iron powder?   [1]  ",
            "17": "17  \u00a9 ucles 2006 0620/02/o/n/06  for  examiner's  use    (iii) what will happen to the speed of the reaction if it is carried out at 20\u00b0c rather than at 30\u00b0c?   [1]     ",
            "18": "18   0620/02/o/n/06 blank page",
            "19": "19    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.   0620/02/o/n/06 blank page",
            "20": "20  \u00a9 ucles 2006 0620/02/o/n/06  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89                9 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series  90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w06_qp_3.pdf": {
            "1": "this document consists of 14 printed pages and 2 blank pages.  ib06 11_0620_03/5rp   \uf6d9 ucles 2006    [turn over   university of cambridge international examinations   international general certificate of secondary education       chemistry       paper 3 (extended) 0620/03        october/november 2006       1 hour 15 minutes   candidates answer on the question paper.   no additional materials required.                                  read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen in the spaces provided on the question paper.  you may use a pencil for any diagrams, graphs or rough working.  do not use staples, paper clips, highlighters, glue or correction fluid.  do not  write in the barcode.  do not  write in the grey areas between the pages.    answer all questions.  the number of marks is given in brackets [  ] at the end of each question   or part question.  a copy of the periodic table is printed on page 16.   candidate name centrenumber candidatenumbe r*062003* 6 7 8 totalfor examiner's use 1 234 5",
            "2": "2  \u00a9 ucles 2006 0620/03/o/n/06 for  examiner's  use 1 choose a gas from the following list to answer the questions below.  each gas may be used  once, more than once or not at all.      ammonia argon  carbon dioxide  carbon monoxide  chlorine  ethene  hydrogen  nitrogen  oxygen       which gas    (i) is a noble gas,         (ii) is an acidic oxide,          (iii) can be polymerised,          (iv) is the active component of air,          (v) is used in the treatment of water,         (vi) is a product of respiration?        [6]    ",
            "3": " 3   \u00a9 ucles 2006 0620/03/o/n/06 [turn over  for  examiner's  use 2 the table shows the melting points, boiling points and electrical properties of the six  substances a to f.      substance melting point / oc boiling point / oc electrical conductor  at room  temperature electrical  conductor of  substance  dissolved in water a 961 2193 good does not dissolve  b 113 444 does not conduct does not dissolve  c 0 100 very poor very poor  d 803 1465 does not conduct good  e \u20135 to -10 102 to 105 good good  f -85 -60 does not conduct does not dissolve        (i) which three  substances are solids at room temperature?   [1]       (ii) which one  is an ionic compound?   [1]      (iii) which one  is a gas at room temperature?   [1]      (iv) which two substances are liquids at room temperature?   [1]        (v) which substance is a metal?   [1]       (vi) which one  is an impure substance?   [1]     ",
            "4": "4  \u00a9 ucles 2006 0620/03/o/n/06 for  examiner's  use 3 calcium carbonate is an important raw material.     (a) name a rock which is made up of calcium carbonate.   [1]       (b) when calcium carbonate is heated strongly, it decomposes.  caco 3 \u2192 cao + co 2     (i) calculate the relative formula mass of:  caco 3   cao  [2]       (ii) 7.00 kg of calcium oxide was formed.  what mass of calcium carbonate was  heated?     [2]       (c) calcium carbonate is used to control soil acidity.    (i) why is it important to control soil acidity?   [1]   (ii) both calcium carbonate, insoluble in water, and calcium oxide, slightly soluble, are used to increase soil ph.  suggest two advantages of using calcium carbonate.     [2]     (iii) give one use of calcium carbonate other than for making calcium oxide and  controlling soil ph.   [1]     ",
            "5": " 5   \u00a9 ucles 2006 0620/03/o/n/06 [turn over  for  examiner's  use 4 minimising air pollution is essential for health and for the environment.     (a) natural gas is methane.    (i) write the equation for complete combustion of methane.   [2]    (ii) explain why it is dangerous to use a gas fire in a poorly ventilated room.     [2]      (b) low sulphur fuels are being introduced.  ordinary diesel contains 500  ppm of sulphur  but low sulphur diesel contains less than 50  ppm.  why is this an advantage to the  environment?     [2]       (c) catalytic converters reduce pollution from motor vehicles, as shown in the following  diagram.    oxides of nitrogen carbon monoxideunburnt hydrocarbonsless harmful gasesto atmosphere catalysts rhodium,platinum, palladium      (i) what type of elements are the metals rhodium, platinum and palladium?   [1]     (ii) rhodium catalyses the decomposition of the oxides of nitrogen.        2no \u2192 n 2 + o 2    two other pollutants are carbon monoxide and unburnt hydrocarbons.  how are  they made into less harmful substances?     [2]     ",
            "6": "6  \u00a9 ucles 2006 0620/03/o/n/06 for  examiner's  use 5 ammonia is manufactured by the haber process.     n 2(g) + 3h 2(g)  2nh 3(g)   200 atmospheres  450\u00b0c     the forward reaction is exothermic.     (a) (i)  what is the catalyst for this reaction?   [1]     (ii) newer catalysts have been discovered for this process.  using these catalysts, the operating temperature is lowered from 450\u00b0c to 400\u00b0c.  what is the advantage of  using a lower temperature?   explain your answer.  advantage   explanation    [2]      (b) after passing over the catalyst, the mixture contains 15% of ammonia.  it is cooled and the ammonia liquefies and is separated from the unreacted nitrogen and hydrogen.   they are recycled.     (i) how are the gases recycled?   [1]     (ii) only ammonia gas liquefies.  suggest an explanation for this.   [1]      (c) urea, co(nh 2)2, is one of the fertilisers manufactured from ammonia.   ammonia is heated with carbon dioxide.   (i) write an equation for the manufacture of urea.   [2]     (ii) explain why urea on its own might not be very effective in promoting crop growth.   [1]     ",
            "7": " 7   \u00a9 ucles 2006 0620/03/o/n/06 [turn over  for  examiner's  use  (d) give a diagram showing the arrangement of the valency electrons in one molecule of  the covalent compound urea.  its structural formula is given below.    ocnh h nhh      use \u03bf to represent an electron from a carbon atom.   use x to represent an electron from a hydrogen atom.  use \u2022 to represent an electron from a nitrogen atom.                      [3]     ",
            "8": "8  \u00a9 ucles 2006 0620/03/o/n/06 for  examiner's  use 6 an ore of copper is the mineral, chalcopyrite.  this is a mixed sulphide of iron and copper.     (a) analysis of a sample of this ore shows that 13.80  g of the ore contained 4.80  g of  copper, 4.20  g of iron and the rest sulphur.   complete the table and calculate the empirical formula of chalcopyrite.     copper iron sulphur  composition by mass  / g 4.80 4.20     number of moles of atoms       simplest mole ratio of atoms        [3]   the empirical formula is   [1]     (b) impure copper is extracted from the ore.  this copper is refined by electrolysis.    (i) name;   the material used for the positive electrode (anode),        the material used for the negative electrode (cathode),        a suitable electrolyte.   [3]    (ii) write an ionic equation for the reaction at the negative electrode.   [1]    (iii) one use of this pure copper is electrical conductors, another is to make alloys.   name the metal that is alloyed with copper to make brass.   [1]     ",
            "9": " 9  \u00a9 ucles 2006 0620/03/o/n/06 [turn over  for  examiner's  use  (c) two of the elements in chalcopyrite are the metal, copper, and the non-metal, sulphur.  these have different properties.  copper is an excellent conductor of electricity and is malleable.  sulphur is a poor conductor and is not malleable, it is brittle.  explain, in terms of their structures, why this is so.     difference in electrical conductivity     [2]     difference in malleability     [2]     ",
            "10": "10  \u00a9 ucles 2006 0620/03/o/n/06 for  examiner's  use 7 the rate of a reaction depends on concentration of reactants, temperature and possibly a  catalyst or light.    (a) a piece of magnesium ribbon was added to 100  cm3 of 1.0  mol/dm3 hydrochloric acid.  the hydrogen evolved was collected in a gas syringe and its volume measured every  30 seconds.    20 40 60 80 100 hydrochloric acid magnesium ribbon     in all the experiments mentioned in this question, the acid was in excess.   the results were plotted to give a graph.    timevolume of hydrogen 0   ",
            "11": " 11  \u00a9 ucles 2006 0620/03/o/n/06 [turn over  for  examiner's  use  (i) the experiment was repeated. two pieces of magnesium ribbon were added to  100  cm3 of 1.0  mol/dm3 hydrochloric acid. sketch this graph on the same grid and  label it x.   [2]     (ii) the experiment was repeated using one piece of magnesium ribbon and 100  cm3  of 1.0 mol/dm3 ethanoic acid.  describe how the shape  of this graph would differ  from the one given on the grid.     [2]      (b) reaction rate increases when concentration or temperature is increased.   using the idea of reacting particles, explain why;     increasing concentration increases reaction rate,     [2]     increasing temperature increases reaction rate.     [2]       (c) the rate of a photochemical reaction is affected by light.  a reaction, in plants, between carbon dioxide and water is photochemical.    (i) name the two products of this reaction.     [2]     (ii) this reaction will only occur in the presence of light and another chemical.  name this chemical.   [1]    ",
            "12": "12  \u00a9 ucles 2006 0620/03/o/n/06 for  examiner's  use 8 the three types of food are carbohydrates, proteins and fats.     (a) aqueous starch is hydrolysed to maltose by the enzyme amylase.   the formula of maltose is:   ho oh o    starch is hydrolysed by dilute sulphuric acid to glucose.   ho oh    (i) what is an enzyme?   [1]    (ii) draw the structure of starch.              [1]    (iii) name the technique that would show that the products of these two hydrolyses are  different.   [1]      (b) proteins have the same linkage as nylon but there is more than one monomer in the  macromolecule.     (i) draw the structure of a protein.                  [2]     (ii) what class of compound is formed by the hydrolysis of proteins?   [1]     ",
            "13": " 13   \u00a9 ucles 2006 0620/03/o/n/06 for  examiner's  use  (c) fats are esters.  some fats are saturated, others are unsaturated.     (i) write the word equation for the preparation of the ester, propyl ethanoate.   [2]     (ii) deduce the structural formula of this ester showing each individual bond.                 [2]   (iii) how could you distinguish between these two fats?   fat 1 has the formula     ch 2 \u2013 co 2 \u2013 c17h33 ch \u2013 co 2 \u2013 c17h33 ch 2 \u2013 co 2 \u2013 c17h33     fat 2 has the formula     ch 2 \u2013 co 2 \u2013 c17h35 ch \u2013 co 2 \u2013 c17h35 ch 2 \u2013 co 2 \u2013 c17h35    test   result with fat 1   result with fat 2  [3]     (iv) both of these fats are hydrolysed by boiling with aqueous sodium hydroxide.  what type of compounds are formed?   and  [2]    ",
            "14": "14  \u00a9 ucles 2006 0620/03/o/n/06 blank page ",
            "15": " 15     permission to reproduce items where third-party owned material prote cted by copyright is included has been sought and cleared w here  possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring  clearance  have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is  itself a department of the university of cambridge.   0620/03/o/n/06 blank page ",
            "16": "16  \u00a9 ucles 2006 0620/03/o/n/06 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w06_qp_5.pdf": {
            "1": "this document consists of 7 printed pages and 1 blank page.  ib06 11_0620_05/3rp   \uf6d9 ucles  2005  [turn over   university of cambridge international examinations   international general certificate of secondary education       chemistry       paper 5 practical test 0620/05        october/november 2006      candidates answer on the question paper.   additional materials:  as listed in instructions  1 hour 15 minutes    to supervisors                                     read these instructions first    write your name, centre number and candidate number on all the work you hand in.  write in dark blue or black pen in the spaces provided on the question paper.  you may use a pencil for any diagrams, graphs or rough working.  do not use staples, paper clips, highlighters, glue or correction fluid.  do not  write in the barcode.  do not  write in the grey areas between the pages.    answer all questions.  the number of marks is given in brackets [  ] at the end of each question or part question.   practical notes are provided on page 8.  candidate name centrenumber candidatenumbe r*062005*    for examiner's use total1 2",
            "2": "2  \u00a9 ucles 2006 0620/05/o/n/06 blank page",
            "3": "3  \u00a9 ucles 2006 0620/05/o/n/06 [turn over  for  examiner's  use 1 you are going to investigate the reactions of three different metals.   magnesium, iron and zinc will be used.   read all the instructions  below carefully before starting the experiments.    instructions     experiment 1      by using a measuring cylinder, pour 5  cm3 of the aqueous copper( ii) sulphate into the test- tube provided.  measure the initial temperature of the solution and record it in the table  below.  add the 1  g sample of zinc powder to the solution in the test-tube and stir the  mixture with the thermometer.  record the maximum temperature reached and any  observations in the table.   remove the thermometer and rinse with water.      experiment 2     repeat experiment 1, using 1  g of iron filings instead of zinc.  record the maximum  temperature reached and any observations in the table.     experiment 3      repeat experiment 1, using the 0.5  g sample of magnesium.  test the gas given off with a  lighted splint.      table of results     experiment  metal  temperature of solution/\u00b0c  observations     initial maximum   1 zinc     2 iron     3 magnesium       [9] ",
            "4": "4  \u00a9 ucles 2006 0620/05/o/n/06 for  examiner's  use  (a) use your results and observations to answer the following questions.     (i) which metal is most reactive with aqueous copper( ii) sulphate?   [1]     (ii) give two reasons why you chose this metal.  1   2  [2]     (iii) name the gas given off in experiment 3.   [1]     you are now going to investigate the reaction between two of the metals and aqueous  copper( ii) sulphate in more detail.    experiment 4     rinse the thermometer with water at room temperature.  by using a measuring cylinder pour  10 cm 3 of aqueous copper( ii) sulphate into a polystyrene cup.  measure the initial  temperature of the solution and record it in the table below.   add the 1  g sample of magnesium powder to the cup and record the temperature every 10  seconds for 1 minute.  record all of your results in the table.    experiment 5     repeat experiment 4 using the 2  g sample of zinc powder instead of magnesium.    record all of your results in the table.   table of results     temperature/\u00b0c   time/seconds   experiment 4 experiment 5  0    10    20    30    40    50    60      [3] ",
            "5": "5  \u00a9 ucles 2006 0620/05/o/n/06 [turn over  for  examiner's  use (b) plot the results of  experiments 4 and 5 on the grid below.  draw two smooth line graphs.   clearly label the graphs.    90 807060504030201001 0 2 0 3 0 time  / seconds40 50 60temperature  / oc    [4]      (c) use your graph  to estimate the temperature of the reaction mixture in experiment 4  after 5 seconds.  indicate clearly  on the graph how you obtained your answer.   [2]    ",
            "6": "6  \u00a9 ucles 2006 0620/05/o/n/06 for  examiner's  use 2 you are provided with solid f and solid g.     carry out the following tests on f and g, recording all of your observations in the table.    conclusions must not be written in the table.    tests observations         [3] (a) place a little of solid f in a hard  glass test-tube.  insert a damp piece of ph paper in the mouth  of the tube.  heat the solid gently, then more strongly.   (b) place the rest of solid f in a  boiling-tube.  add 10  cm3 of  distilled water and shake to dissolve.   divide the solution into 4 equal  portions in test-tubes.  colour    ph  [2]  (c) (i) test the ph of the first  portion of the solution using  universal indicator solution.      [2]  (ii) to the second portion, add about 1  cm3 of aqueous  sodium hydroxide.  heat gently  and test the gas  given off with damp litmus paper.      [2]  (c) (iii) to the third portion of solution, add a few drops of  dilute nitric acid and then  aqueous lead( ii) nitrate.  ",
            "7": "7  \u00a9 ucles 2006 0620/05/o/n/06 [turn over  for  examiner's  use tests observations         [1]  (c) (iv) to the fourth portion of  solution, add a few drops of dilute nitric acid followed by aqueous silver nitrate.   (d) (i) dissolve solid g in about     5 cm3 of distilled water in a  test-tube.  divide the  solution into two equal  portions in two test-tubes.     (ii) repeat (c)(iii)  using the first  portion of the solution.   [2]     [2]  (iii) repeat (c)(iv)  using the  second portion of the  solution.      (e) name the gas given off in (c)(ii) .   [1]     (f) identify solid f.   [2]       (g) name the anion in solid g.   [1]    ",
            "8": "8    permission to reproduce items where third-party owned material prote cted by copyright is included has been sought and cleared w here  possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring  clearance  have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is  itself a department of the university of cambridge.  \u00a9 ucles 2006 0620/05/o/n/06 notes for use in qualitative analysis     test for anions     anion test test result  carbonate (co-2 3) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then  aqueous lead( ii) nitrate yellow ppt.  nitrate (no\u2212 3)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulphate (so-2 4)  [in solution] acidify with dilute nitric acid, then  add aqueous barium nitrate white ppt.   test for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh+ 4) ammonia produced on warming -  calcium (ca2+) white., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution   test for gases     gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_w06_qp_6.pdf": {
            "1": "centre number candidate number name               university of cambridge international examinations    international general certificate of secondary education        chemistry  0620/06         paper 6  alternative to practical    october/november 2006        1 hour    candidates answer on the question paper.     no additional materials required.                           read these instructions first      write your name, centre number and candidate number at the top of this page.   write in dark blue or black pen in the spaces provided on the question paper.   you may use a pencil for any diagrams, graphs or rough working.   do not use staples, paper clips, highlighters, glue or correction fluid.     answer all questions.   the number of marks is given in brackets [  ] at the end of each question or part question.                                 for examiners use   1    2    3    4    5    6    total       this document consists of 13 printed pages and 3 blank pages.  ib06 11_0620_06/4rp   \uf6d9 ucles 2006  [turn over  ",
            "2": "2  \u00a9 ucles 2006 0620/06/o/n/06 for  examiner's  use 1 the diagram shows the formation of a solution of magnesium hydroxide from magnesium.    water magnesium oxide heatindicator turns bluesolution ofmagnesiumhydroxideuniversalindicatorsolution magnesiumburning to formmagnesiumoxide      (a) complete the empty boxes to name the pieces of apparatus. [3]     (b) what type of chemical reaction is the burning of magnesium?   [1]     (c) suggest a ph for the solution of magnesium hydroxide.   [1]     2 the diagram shows the rusting of a sample of iron filings.    150  mm125  mmair before rustingair after rusting waterdamp iron filings      (a) what colour are the rusty filings?   [1]     (b) why does the water rise up the tube after rusting?   [1]   ",
            "3": "3  \u00a9 ucles 2006 0620/06/o/n/06 [turn over  for  examiner's  use  (c) calculate the percentage of air used in the rusting of the iron.     [2]       (d) how would the results differ if pure oxygen was in the tube instead of air before rusting?   [1]     ",
            "4": "4  \u00a9 ucles 2006 0620/06/o/n/06 for  examiner's  use 3 an investigation into the reaction of calcium with water was carried out using the apparatus  below.  the temperature of the water increased during the experiment.    20 40 60 80 100cm3 reaction mixture          the volume of hydrogen collected at one minute intervals was measured.  use the  diagrams to record the volumes in the table.    10 20 30 40 50 60 70 80 90time  / minutes 0 1 23456syringe diagram volume of gas  / cm3 10 20 30 40 50 60 70 80 90 10 20 30 40 50 60 70 80 90 10 20 30 40 50 60 70 80 90 10 20 30 40 50 60 70 80 90 10 20 30 40 50 60 70 80 90 10 20 30 40 50 60 70 80 90      [2] ",
            "5": "5  \u00a9 ucles 2006 0620/06/o/n/06 [turn over  for  examiner's  use  (a) plot the results on the grid. join all of the results with a smooth curve.    0123456volume of gas  / cm3100 80 604020 0 time  / minutes     [3]     (b) what type of chemical reaction occurs when calcium reacts with cold water?   [1]       (c) (i)  use the graph to describe how the speed of this reaction changes during the six  minutes.     [2]     (ii) explain possible reasons for the changes in (c)(i) .       [2]     ",
            "6": "6  \u00a9 ucles 2006 0620/06/o/n/06 for  examiner's  use 4 an investigation was carried out into the reactions of aqueous copper( ii) sulphate with  magnesium, iron and zinc.     experiment 1      by using a measuring cylinder, 5  cm3 of aqueous copper( ii) sulphate was added to each of  three test-tubes.  the initial temperature of the solution was measured.  zinc powder was  added to the first test-tube, iron powder to the second tube and magnesium powder to the  third tube.  the mixtures were stirred with the thermometer.  all the observations were recorded and the maximum temperature reached measured.    (a) use the thermometer diagrams to complete the results table.    table of results     metal addedtemperature of solution  / ocobservations moderate  effervescence, solution paler, brown solid. little  effervescence, brown solid. rapid effervescence, pops with lighted splint, brown solid.temperature difference  / oc  zinc iron magnesiuminitial maximum 30 2520605550 302520757065302520454035       [4]    (b) use your results and observations to answer the following questions.     (i) which metal is most reactive with aqueous copper( ii) sulphate?   [1]     (ii) give two reasons why you chose this metal.  1   2  [2]     (iii) identify the gas given off when magnesium reacts with aqueous copper( ii)  sulphate.   [1]  ",
            "7": "7  \u00a9 ucles 2006 0620/06/o/n/06 [turn over  for  examiner's  use  (c) the reactions of magnesium and zinc with aqueous copper( ii) sulphate were  investigated in more detail.     experiment 2      by using a measuring cylinder 10  cm3 of aqueous copper( ii) sulphate was poured into  a polystyrene cup.  the initial temperature of the solution was measured.   a 1  g sample of magnesium powder was added to the cup and the temperature  measured every 10 seconds for 1 minute.    use the thermometer diagrams on page 8  to complete the results table.     experiment 3      experiment 2 was repeated using zinc powder instead of magnesium.    use the thermometer diagrams on page 8  to complete the results table.   ",
            "8": "8  \u00a9 ucles 2006 0620/06/o/n/06 for  examiner's  use  table of results     30 2520time  / seconds 0 10 20 30 40 50 60temperature  / oc experiment 2 experiment 3 30 2520 656055 706560353025 403530757065 706560454035 504540706560302520 605550 353025     [6] ",
            "9": "9  \u00a9 ucles 2006 0620/06/o/n/06 [turn over  for  examiner's  use  (d) plot the results of both experiments on the grid below.  draw two smooth line graphs.   clearly label the graphs.    10 20 30 time  / secondstemperature  / oc 40 50 6070 605040302010 0    [4]      (e) use your graph  to estimate the temperature of the reaction mixture in experiment 2  after 5 seconds.  indicate clearly  on the graph how you obtained your answer.   [2]     (f) sketch lines on the grid to show the predicted results if experiment 2 were repeated using:     (i) larger pieces of magnesium;     (ii) iron powder.     clearly label the lines. [2] ",
            "10": "10  \u00a9 ucles 2006 0620/06/o/n/06 for  examiner's  use  (g) why is a polystyrene cup used instead of a glass container?   [1]      (h) suggest one improvement to the method in experiment 2.   [1]    ",
            "11": "11  \u00a9 ucles 2006 0620/06/o/n/06 [turn over  for  examiner's  use 5 two solids, f and g, were analysed.  solid f was an ammonium salt and solid g was a  potassium salt.     the tests on f and g and some of the observations are in the following table.     complete the observations in the table.    tests  observations    solid f was added to distilled water  and shaken to dissolve.   the solution was divided into 4 equal  portions in test-tubes.  colour orange  (a) (i) the ph of the first portion of the solution was tested using universal indicator  solution.  ph  5      [2]  (ii) aqueous sodium hydroxide  was added to the second portion and heated gently.  the gas given off was  tested with damp litmus  paper.  white precipitate  (iii) to the third portion of  solution, was added dilute nitric acid and then aqueous  lead( ii) nitrate.   (iv) to the fourth portion of  solution, was added dilute  nitric acid followed by  aqueous silver nitrate. white precipitate   (b) (i)  solid g was dissolved in  distilled water.  the solution was divided into two test-tubes.  bright yellow precipitate  (ii) (a)(iii)  was repeated using  the first portion of the solution.   (iii) (a)(iv)  was repeated using  the second portion of the solution. pale yellow precipitate ",
            "12": "12  \u00a9 ucles 2006 0620/06/o/n/06 for  examiner's  use  (c) what conclusion can be drawn from test (a)(i) ?   [2]      (d) name the gas given off in (a)(ii) .   [1]     (e) identify solid f.   [1]     (f) identify solid g.   [1]     ",
            "13": "13  \u00a9 ucles 2006 0620/06/o/n/06 for  examiner's  use 6 you are provided with a pot of paint as shown below.    coloured solids liquid magnified view of paint     the paint is a mixture of a liquid and a solid.   the liquid can be dissolved in water. the solids are insoluble in water but soluble in organic  solvents.    (a) how can a sample of the solid be separated from the rest of the paint?       [2]       (b) how would you determine the number of coloured substances contained in the solid you separated in (a)?         [4]     (c) the label on the paint tin states    \u201ctouch-dry in three hours\u201d    (i) how could you check this value?     [2]     (ii) suggest how you could speed up this drying process.   [1]   ",
            "14": "14   0620/06/o/n/06 blank page",
            "15": "15   0620/06/o/n/06 blank page",
            "16": "16    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the university of cambridge local examinations syndicate (ucles),  which is itself a department  of the university of cambridge.   0620/06/o/n/06 blank page "
        }
    },
    "2007": {
        "0620_s07_qp_1.pdf": {
            "1": "    this document consists of 16 printed pages.  ib07 06_0620_01/2rp  \u00a9 ucles 2007  [turn over       *3849119746* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/01     paper 1 multiple choice  may/june 2007     45 minutes    additional materials: multiple choice answer sheet    soft clean eraser    soft pencil (type b or hb is recommended)        read these instructions first    write in soft pencil.  do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided  unless this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.   read the instructions on the answer sheet very carefully.    each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.       ",
            "2": "2    \u00a9 ucles 2007 0620/01/m/j/07 1 when there is no wind, the scent of flowers can be detected more easily on a warm evening than  on a cold evening.    this is because the molecules of the scent   \u2026\u20261\u2026\u2026    \u2026\u20262\u2026\u2026   than in colder conditions.    which words correctly complete gaps 1 and 2?     gap 1 gap 2  a condense nearer to the flowers  b condense further from the flowers  c diffuse nearer to the flowers  d diffuse further from the flowers     2 a student investigates if, at 30  oc, the concentration of acid affects how rapidly it reacts with a  known mass of magnesium.    the student has a beaker, concentrated acid, water and the apparatus below.   p a balance  q a clock  r a measuring cylinder s a thermometer    which of these pieces of apparatus does the student use?  a p, q and r only  b p, q and s only  c q, r and s only  d p, q, r and s      3 the boiling point of liquid x is lower than that of water. to test a student, a teacher covers up the numbers on a thermometer. the student places the thermometer in boiling liquid x.    the diagram represents part of the stem of this thermometer.    mercury    what could the temperature on the thermometer be?  a 75.5  \u00b0c b 84.5  \u00b0c c 104.5  \u00b0c d 105.5  \u00b0c     ",
            "3": "3    \u00a9 ucles 2007  0620/01/m/j/07  [turn over  4 which mixture can be separated by adding water, stirring and filtering?  a barium chloride and sodium chloride  b copper and magnesium   c diamond and graphite  d silver chloride and sodium nitrate      5 an atom has the symbol xp q.    which value determines the position of the element in the periodic table?  a p  b q  c p \u2013 q   d p + q     6 element y is in the second period of the periodic table. an atom of element z has six more  protons than an atom of element y.    which statement must  be correct?  a elements y and z are in the same period.  b elements y and z have the same number of electrons in the first shell.  c element z has six more electrons in its outer shell than element y.  d the nucleon number of element z is six more than that of element y.    7 the diagram shows the structure of methane.   hhh hc     what is the total number of electrons used for bonding in this molecule?  a 2 b 4 c 8 d 10     ",
            "4": "4    \u00a9 ucles 2007 0620/01/m/j/07 8 the diagram shows the structure of a substance.        what is represented?  a diamond  b ethane  c graphite  d poly(ethene)      9 in the diagrams, circles of different sizes represent atoms of different elements.    which diagram can represent hydrogen chloride gas?    b ac d     10 boron, b, forms an oxide.    which equation is correctly balanced?  a 2b + 3o 2 \u2192 b 2o3  b 2b + 3o 2 \u2192 2b 2o3  c 4b + 2o 2 \u2192 2b 2o3  d 4b + 3o 2 \u2192 2b 2o3     ",
            "5": "5    \u00a9 ucles 2007  0620/01/m/j/07  [turn over  11 students are asked to state    \u2022 the number of atoms in one molecule of ethanoic acid,  \u2022 the relative molecular mass, mr, of this acid.    which line is correct?     number of atoms mr  a 8 32  b 8 60  c 9 26  d 9 46      12 a molten compound is electrolysed. two atoms of x are deposited at the negative electrode at  the same time as three atoms of y are deposited at the positive electrode.    these results show that:  x is a \u20261\u2026;  y is a \u20262\u2026;  the formula of the compound is \u20263\u2026 .    how are gaps 1, 2 and 3 correctly completed?     1 2 3  a metal non-metal x 3y2  b metal non-metal x 2y3  c non-metal metal x 3y2  d non-metal metal x 2y3      13 in which electrolyses are chlorine, hydrogen and sodium hydroxide all produced?     aqueous sodium chloride molten sodium chloride  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "6": "6    \u00a9 ucles 2007 0620/01/m/j/07 14 the diagram shows a match.        by striking the match, a chemical reaction takes place.    which statements about the chemical reaction are correct?     type of reaction reason  a endothermic because energy is used to strike the match  b endothermic because energy is given out as the match burns  c exothermic because energy is used to strike the match  d exothermic because energy is given out as the match burns      15 which process is not exothermic?  a burning a fossil fuel  b obtaining lime from limestone  c radioactive decay of 235u  d reacting hydrogen with oxygen      16 three reactions used in the manufacture of sulphuric acid are shown.    1 s + o 2 \u2192 so 2  2 2so 2 + o 2 \u2192 2so 3  3 so 3 + h 2o \u2192 h 2so 4    which of these reactions are redox reactions?  a 1 only  b 3 only  c 1 and 2 only  d 2 and 3 only     ",
            "7": "7    \u00a9 ucles 2007  0620/01/m/j/07  [turn over  17 in an experiment using dilute acid and a metal, the speed at which hydrogen is released is  measured (curve x on graph).    the experiment is repeated but with one of the conditions changed (curve y on graph).    y x 00total volume of hydrogen time    which changes in condition could result in curve y?     increase in  concentration of acid increase in particle  size of metal increase in  temperature  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0013     18 aqueous sodium hydroxide and aqueous ammonia each give a white precipitate when added to  aqueous zinc sulphate.    what happens when an excess of each of these reagents is added?     excess naoh(aq) excess nh 3(aq)  a precipitate dissolves precipitate dissolves   b precipitate dissolves  precipitate does not dissolve  c precipitate does not dissolve precipitate dissolves   d precipitate does not dissolve precipitate does not dissolve    ",
            "8": "8    \u00a9 ucles 2007 0620/01/m/j/07 19 aqueous sodium hydroxide is added to two different solutions with the results shown.    xy green precipitate formed light blue precipitate formed     what are the cations present in x and y?     x y  a copper( ii) iron( ii)  b copper( ii) iron( iii)  c iron( ii) copper( ii)  d iron( iii) copper( ii)     20 in which experiment does the limewater not turn milky?    limewateracid magnesium carbonateab limewater ethanolsuction pump d limewaterc acid iron filingslimewater      ",
            "9": "9    \u00a9 ucles 2007  0620/01/m/j/07  [turn over  21 two indicators, bromophenol blue and congo red, show the following colours in acidic solutions  and in alkaline solutions.    indicator acid alkali  bromophenol blue yellow blue  congo red violet red    a few drops of each indicator are added to separate samples of a solution of ph 2.    what are the colours of the indicators in this solution?    in a solution of ph 2    bromophenol blue is congo red is  a blue red  b blue violet  c yellow red  d yellow violet      22 aqueous lead( ii) nitrate is added to a solution containing iodide ions. lead( ii) iodide is formed.    which type of reaction takes place?  a neutralisation  b oxidation  c precipitation  d reduction     23 the diagram shows an outline of part of the periodic table.    w yx z    which two elements could form a covalent compound?  a w and x b w and y c x and y d x and z    ",
            "10": "10    \u00a9 ucles 2007 0620/01/m/j/07 24 which substances react with aqueous potassium bromide to form bromine?     chlorine iodine  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     25 why are some weather balloons filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen. c helium is more dense than hydrogen. d helium is unreactive.     26 the table shows the densities of some group i metals.    which of these metals sinks in benzene (density = 0.88  g / cm3) but floats in nitrobenzene   (density = 1.2  g / cm3)?     metal density, in g  / cm3  a lithium 0.53  b sodium 0.97  c potassium 0.86  d rubidium 1.53    27 the diagram shows the properties of four substances.    which one could be magnesium?    does it bend or break easily? bends breaks does it react with dilute hydrochloric acid?does it react with dilute hydrochloric acid? yes yes no no ab c d    ",
            "11": "11    \u00a9 ucles 2007  0620/01/m/j/07  [turn over  28 in \u2018native\u2019 copper, the element occurs as the metal, not as a compound.     gold is below copper in the reactivity series.    which can be deduced about the properties of gold?     it occurs \u2018native\u2019 it reacts with dilute  sulphuric acid  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     29 the diagram shows a method for displacing a metal from its oxide.    hydrogenmetal oxide heatexcess of hydrogen burning     which metal can be displaced from its oxide by using this method?  a calcium  b copper  c magnesium  d potassium     30 stainless steel is used to make cutlery. aluminium is used to make food containers.    which property do both  metals have that makes them suitable for these uses?  a they are good conductors of electricity.  b they are good conductors of heat.  c they are resistant to corrosion.  d they are very strong.    ",
            "12": "12    \u00a9 ucles 2007 0620/01/m/j/07 31 which process takes place in the conversion of iron into steel?  a basic oxides are removed.  b carbon is converted to carbon dioxide.  c iron is oxidised.  d iron oxide is reduced.      32 in which industrial process is the presence of water not essential?  a the electrolytic purification of copper  b the production of ethanol from ethene  c the production of ethanol by fermentation  d the production of iron in the blast furnace     33 the pie chart represents the composition of air.    x     what is gas x?  a carbon dioxide  b hydrogen  c nitrogen  d oxygen     ",
            "13": "13    \u00a9 ucles 2007  0620/01/m/j/07  [turn over  34 the diagram shows an experiment in which ammonia is released.    heatammonia mixture of solution x andaqueous ammonium sulphatedamplitmus paper     which line in the table is correct?     solution x  final colour of litmus paper  a aqueous sodium hydroxide blue  b aqueous sodium hydroxide red  c dilute sulphuric acid blue  d dilute sulphuric acid red     35 a bag of fertiliser \u2018watch it grow\u2019 contains ammonium sulphate and potassium sulphate.    which of the three elements n, p and k does \u2018watch it grow\u2019 contain?     n p k  a \u0013 \u0013 \u0017  b \u0013 \u0017 \u0013  c \u0017 \u0017 \u0013  d \u0017 \u0013 \u0017    ",
            "14": "14    \u00a9 ucles 2007 0620/01/m/j/07 36 when limestone is heated very strongly in air, lime is made.    what is the formula of limestone and of lime?     limestone lime  a caco 3 cao  b caco 3 ca(oh) 2  c cao caco 3  d ca(oh) 2 caco 3     37 bromine and steam each react with ethene.    which of these reactions need a catalyst?     br 2 / ethene steam  / ethene  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    38 what are formed when glucose is fermented?  a ethanol and carbon dioxide  b ethanol and oxygen  c ethene and carbon dioxide  d ethene and oxygen    39 which formula represents a compound that dissolves in water to form an acidic solution?    a hh hchhchhchc hhhchhchhchhcohd hhhchhcc oo hb hh hch chhc      ",
            "15": "15      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    \u00a9 ucles 2007  0620/01/m/j/07   40 butane reacts as shown.    butane butene + hydrogencatalyst and heat    what is this type of reaction?  a combustion  b cracking  c polymerisation  d reduction     ",
            "16": "16      university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/01/m/j/07  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements    "
        },
        "0620_s07_qp_2.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib07 06_0620_02/6rp  \u00a9 ucles 2007  [turn over      *2339708426* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/02     paper 2  may/june 2007     1 hour 15 minutes    candidates answer on the question paper.    no additional materials required.      read these instructions first    write your centre number, candidate number and name in the spaces at the top of this page.  write in dark blue or black pen. you may need to use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [ ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2007 0620/02/m/j/07  for  examiner's  use 1 the structures of some elements and compounds are shown below.    s ss ss sss hhc hh hc hh hh ch n hh hpb pb pb pb pb pb pb pb pb pbpb pb pb pbna+cl \u2013 na+cl \u2013na+ cl \u2013na+cl \u2013na+cl \u2013 na+cl \u2013na+ cl \u2013na+cl \u2013na+ cl \u2013na+cl \u2013ab c de f       (a) answer these questions using the letters a to f.    (i) which structure is ethane?  [1]   (ii) which structure contains ions?  [1]   (iii) which structure is a gas that turns moist red litmus paper blue?  [1]    (iv) which structure is sodium chloride?  [1]    (v) which structure is the main constituent of natural gas?  [1]   (vi) which two structures are organic compounds?  [1]   (vii)  which two structures are elements?  [1]  ",
            "3": "3  \u00a9 ucles 2007 0620/02/m/j/07 [turn over  for  examiner's  use  (b) structure f is lead.     (i) what is the source of the small amount of lead present in the air?   [1]    (ii) state an adverse effect of lead on health.   [1]     (c) structure a is sulphur. explain why burning fossil fuels containing sulphur is harmful to  the environment.     [2]    [total: 11]     ",
            "4": "4  \u00a9 ucles 2007 0620/02/m/j/07  for  examiner's  use 2 clean air contains a number of different gases.      (a) state the names of the two gases which make up most of the air.   [2]     (b) a sample of air is drawn through the apparatus shown below.      white (anhydrous) copper sulphatelimewaterairtosuctionpump heated copper        (i) when the air is drawn through the apparatus, the lime water turns milky. which gas turns lime water milky?   [1]   (ii) the white (anhydrous) copper sulphate turns blue. state the name of the substance which turns white copper sulphate blue.   [1]   (iii) oxygen is removed from the air by passing it over heated copper.   complete the equation for this reaction.   2cu   +  \u2192  cuo [2]  ",
            "5": "5  \u00a9 ucles 2007 0620/02/m/j/07 [turn over  for  examiner's  use  (c) pure air contains about 1% argon.     (i) in which period of the periodic table is argon?   [1]   (ii) state the name  of the group of elements to which argon belongs.   [1]   (iii) draw the electronic structure of argon.                          [1]    (iv) why is argon used in lamps?   [1]   (v) an isotope of argon has a mass number of 40.   calculate the number of neutrons in this isotope of argon.   [1]    (d) a small amount of xenon is present in the air.   a few compounds of xenon have been made in recent years.    calculate the relative molecular mass of xenon difluoride, xef 2.                [1]   ",
            "6": "6  \u00a9 ucles 2007 0620/02/m/j/07  for  examiner's  use  (e) the structure of another compound of xenon is shown below.      xe ffffo       (i) write the simplest formula for this compound of xenon.   [1]      (ii) describe the type of bonding in this compound.   [1]     [total: 14]   ",
            "7": "7  \u00a9 ucles 2007 0620/02/m/j/07 [turn over  for  examiner's  use 3 hydrogen is a fuel which can be obtained from water by electrolysis.   petrol is a fuel obtained by the fractional distillation of petroleum.     (a) (i) complete the equation for the burning of hydrogen.      h 2 + o 2 \u2192  h 2o [1]    (ii) suggest why hydrogen is a renewable source of energy.   [1]     (iii) when hydrogen is burnt, heat is given off. state the name of the type of reaction  which gives off heat.   [1]     (b) petrol is a mixture of alkanes.   one of the alkanes in petrol is octane, c 8h18.    what products are formed when octane is completely burnt in air?   [2]     (c) petrol is only one of the fractions obtained from the fractional distillation of petroleum.   state the name of two other  fractions obtained from the distillation of petroleum. give a  use for each of these fractions.     fraction   use   fraction   use  [4]     ",
            "8": "8  \u00a9 ucles 2007 0620/02/m/j/07  for  examiner's  use  (d) more petrol can be made by cracking less useful petroleum fractions.      (i) what do you understand by the term cracking ?   [1]      (ii) state two conditions needed for cracking.   [2]      (iii) alkenes can be formed by cracking. the simplest alkene is ethene.   draw a diagram to show the structure of ethene.  show all atoms and bonds.                          [1]     [total: 13]     ",
            "9": "9  \u00a9 ucles 2007 0620/02/m/j/07 [turn over  for  examiner's  use 4 catalysts are often used in industry.     (a) (i) what do you understand by the term catalyst?   [1]   (ii) which type of metals often act as catalysts?   [1]    (b) a student measured the volume of hydrogen gas produced when a few large pieces of  zinc reacted with hydrochloric acid of concentration 2.0 mol  / dm3. the hydrochloric acid  was in excess.   the results are given in the table.    time  / minutes 0 10 20 30 40 50 60  volume of hydrogen  / cm3 0 27 54 81 100 110 110      (i) plot a graph of volume of hydrogen agai nst time on the axes below. label the  axes.        [4] ",
            "10": "10  \u00a9 ucles 2007 0620/02/m/j/07  for  examiner's  use    (ii) copper ions catalyse the reaction between zinc and hydrochloric acid.    on the axes above, sketch the line you would expect for the catalysed reaction.  label this line c. [2]     (iii) explain why no more hydrogen is given off after 50 minutes.   [1]     (c) what would happen to the speed of the reaction if     (i) small pieces of zinc were used instead of large pieces,   [1]   (ii) the concentration of hydrochloric acid was 1.0  mol  / dm3?   [1]     (d) the equation for this reaction is    zn + 2hc l \u2192 zncl 2 + h 2    (i) state the name of the salt formed in this reaction.   [1]   (ii) describe a test for hydrogen.    test   result  [2]    [total: 14]    ",
            "11": "11  \u00a9 ucles 2007 0620/02/m/j/07 [turn over  for  examiner's  use 5 some sunglasses are made from glass which darkens in bright sunlight. the glass contains  tiny crystals of silver chloride and copper( i) chloride.     (a) in bright sunlight, in the presence of copper( i) chloride, the silver chloride breaks down  to solid silver which darkens the glass.    ag+(s) + e-   \u2192    ag(s)     state the name of the particle with the symbol e-.   [1]   (b) silver is a metal. state two physical properties which are characteristic of all metals.     [2]    (c) in bright sunlight, the copper( i) chloride in the sunglasses is converted to copper( ii)  chloride.   what do the roman numerals ( i) and ( ii) show in these copper compounds?   tick one box.    the number of atoms of copper in the copper compounds      the number of neutrons in the copper compounds      whether the copper is in the solid, liquid or gaseous state      the oxidation state of the copper in the copper compounds     [1]    (d) describe a test for aqueous copper( ii) ions.    test   result    [3]    (e) give a common use of copper.   [1]   [total: 8]   ",
            "12": "12  \u00a9 ucles 2007 0620/02/m/j/07  for  examiner's  use 6 the halogens are a group of elements showing trends in colour, state and reaction with  other halide ions.    (a) complete the word equation for the re action of chlorine with aqueous potassium  bromide.      chlorine + potassium bromide   \u2192     +  [2]    (b) explain why an aqueous solution of iodine does not react with potassium chloride.   [1]     (c) the table shows the properties of some halogens.      halogen state at room  temperature colour boiling point  / \u00b0c density of solid  /  g cm-3  fluorine gas yellow  1.51  chlorine  green \u221235 1.56  bromine liquid red-brown 59   iodine solid  184 4.93    (i) complete the missing spaces in the table. [2]    (ii) suggest values for    the boiling point of fluorine,   the density of bromine.  [2]    (d) how many electrons does an atom of fluorine have    (i) in total,   (ii) in its outer shell?  [2]    (e) state a use for chlorine.     [1]    [total: 10]   ",
            "13": "13  \u00a9 ucles 2007 0620/02/m/j/07 [turn over  for  examiner's  use 7 aluminium is extracted by the electrolysis of aluminium oxide dissolved in cryolite.    b d ca a a+ \u2013positive electrode electrolyte (aluminium oxide dissolvedin molten cryolite) molten aluminiumsteel casenegative electrode      (a) what information in the diagram shows that aluminium is more dense than the electrolyte?   [1]     (b) what form of carbon is used for the electrodes in this electrolysis?   [1]     (c) which letter in the diagram, a, b, c or d, represents the anode?   [1]    (d) suggest why electrolysis is used to extract aluminium rather than reduction using  carbon.   [1]     (e) oxygen gas is released at the anode.    (i) where does this oxygen come from?   [1]    (ii) the oxygen reacts with the carbon anode to form carbon dioxide.   what is the formula of carbon dioxide?   [1]    (iii) why does the anode decrease in size during electrolysis?   [1]  ",
            "14": "14  \u00a9 ucles 2007 0620/02/m/j/07  for  examiner's  use  (f) each electrolysis cell makes 212  kg of aluminium per day from 400  kg of aluminium  oxide.   calculate how much aluminium can be made from 1 tonne (1000  kg) of aluminium  oxide.               [1]     (g) complete the following sentences about the electrolysis of aluminium oxide using words from the following list.    atoms   gaseous   molten solid  ions  molecules     aluminium oxide conducts electricity when it is   because it  contains  which are free to move. [2]   [total: 10]   ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/02/m/j/07 blank page",
            "16": "16  \u00a9 ucles 2007 0620/02/m/j/07 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s07_qp_3.pdf": {
            "1": "    this document consists of 14 printed pages and 2 blank pages.  ib07 06_0620_03/4rp  \u00a9 ucles 2007  [turn over      *6703363366* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/03     paper 3 (extended)  may/june 2007     1 hour 15 minutes    candidates answer on the question paper.    no additional materials required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen in the spaces provided on the question paper. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid.  do not  write in any barcodes.    answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2007 0620/03/m/j/07 for  examiner's  use 1 a major source of energy is the combustion of fossil fuels.     (a) (i) name a solid fossil fuel.   [1]   (ii) name a gaseous fossil fuel.   [1]   (b) petroleum is separated into more useful fractions by fractional distillation.     (i) name two liquid fuels obtained from petroleum.   and  [2]    (ii) name two other useful products obtained from petroleum that are not used as  fuels.   and  [2]   (iii) give another mixture of liquids that is separated on an industrial scale by fractional distillation.   [1]    [total: 7]   ",
            "3": "3  \u00a9 ucles 2007 0620/03/m/j/07 [turn over  for  examiner's  use 2 complete the following table.    type of  structure particles present electrical  conductivity  of solid electrical  conductivity of  liquid example           ionic positive and negative  ions poor          macro  molecular atoms of two different  elements in a giant  covalent structure poor poor         and           metallic     good     copper      [total: 6]    ",
            "4": "4  \u00a9 ucles 2007 0620/03/m/j/07 for  examiner's  use 3 there are three methods of preparing salts.     method a \u2013 use a burette and an indicator.    method b \u2013 mix two solutions and obtain the salt by precipitation.     method c \u2013 add an excess of base or a metal to a dilute acid and remove the excess by  filtration.     for each of the following salt preparations, choose one of the methods a, b or c, name any  additional reagent needed and then write or complete the equation.     (i) the soluble salt, zinc sulphate, from the insoluble base, zinc oxide    method   reagent   word equation  [3]     (ii) the soluble salt, potassium chloride, from the soluble base, potassium hydroxide    method   reagent   equation  +   \u2192 kc l + h 2o [3]    (iii) the insoluble salt, lead( ii) iodide, from the soluble salt, lead( ii) nitrate    method   reagent   equation pb2+ +  \u2192  [4]    [total: 10]     ",
            "5": "5  \u00a9 ucles 2007 0620/03/m/j/07 [turn over  for  examiner's  use 4 use your copy of the periodic table to help you answer these questions.     (a) predict the formula of each of the following compounds.    (i)  barium oxide  [1]   (ii)  boron oxide  [1]     (b) give the formula of the following ions.    (i)  sulphide  [1]    (ii)  gallium  [1]    (c) draw a diagram showing the arrangement of the valency electrons in one molecule of the covalent compound nitrogen trichloride.                 use x to represent an electron from a nitrogen atom.   use o to represent an electron from a chlorine atom. [3]      (d) potassium and vanadium are elements in period iv.     (i) state two differences in their physical properties.     [2]     (ii) give two differences in their chemical properties.     [2]     ",
            "6": "6  \u00a9 ucles 2007 0620/03/m/j/07 for  examiner's  use  (e) fluorine and astatine are halogens. use your knowledge of the other halogens to  predict the following:    (i) the physical state of fluorine at r.t.p.    the physical state of astatine at r.t.p.  [2]   (ii) two similarities in their chemical properties     [2]    [total 15]     ",
            "7": "7  \u00a9 ucles 2007 0620/03/m/j/07 [turn over  for  examiner's  use 5 (a) titanium is produced by the reduction of its chloride. this is heated with magnesium in  an inert atmosphere of argon.    tic l4  +  2mg  \u2192  ti  +  2mgc l2    (i) explain why it is necessary to use argon rather than air.   [1]    (ii) name another metal that would reduce titanium chloride to titanium.   [1]   (iii) suggest how you could separate the metal, titanium, from the soluble salt magnesium chloride.     [2]    (b) titanium is very resistant to corrosion. one of its uses is as an electrode in the cathodic  protection of large steel structures from rusting.    + \u2013power steel oil rig which is cathode sea water containsh +(aq), oh\u2013(aq), na+(aq), cl\u2013(aq)titaniumanode      (i) define oxidation in terms of electron transfer.   [1]    (ii) the steel oil rig is the cathode. name the gas formed at this electrode.   [1]   (iii) name the two gases formed at the titanium anode.   and  [2]   (iv) explain why the oil rig does not rust.     [2]   ",
            "8": "8  \u00a9 ucles 2007 0620/03/m/j/07 for  examiner's  use  (v) another way of protecting steel from corrosion is sacrificial protection.   give two differences between sacrificial protection and cathodic protection.     [2]    [total: 12]     ",
            "9": "9  \u00a9 ucles 2007 0620/03/m/j/07 [turn over  for  examiner's  use 6 aluminium is extracted by the electrolysis of a molten mixture that contains alumina, which  is aluminium oxide, a l2o3.    (a) the ore of aluminium is bauxite. this contains alumina, which is amphoteric, and    iron( iii) oxide, which is basic. the ore is heated with aqueous sodium hydroxide.   complete the following sentences.   the  dissolves to give a solution of   the  does not dissolve and can be removed by  [4]       (b) complete the labelling of the diagram.    waste gases carbon anode (+) mixture of aluminium oxide and .  temperature is  ... (\u2013)      [4]     (c) the ions that are involved in the electrolysis are a l3+ and o2-.     (i) write an equation for the reaction at the cathode.   [2]    (ii) explain how carbon dioxide is formed at the anode.     [2]  ",
            "10": "10  \u00a9 ucles 2007 0620/03/m/j/07 for  examiner's  use  (d) give an explanation for each of the following.     (i) aluminium is used extensively in the manufacture of aircraft.   [1]   (ii) aluminium is used to make food containers.   [2]   (iii) aluminium electricity cables have a steel core.   [1]   [total: 16]    ",
            "11": "11  \u00a9 ucles 2007 0620/03/m/j/07 [turn over  for  examiner's  use 7 esters, fats and polyesters all contain the ester linkage.     (a) the structural formula of an ester is given below.    c hh hh c c oo hh hh chh hh cc     name two chemicals that could be used to make this ester and draw their structural  formulae. show all bonds.    names  and  [2]   structural formulae                [2]     (b) (i)  draw the structural formula of a polyester such as terylene .                [2]     (ii) suggest a use for this polymer.   [1]   ",
            "12": "12  \u00a9 ucles 2007 0620/03/m/j/07 for  examiner's  use  (c) cooking products, fats and vegetable oils, are mixtures of saturated and unsaturated  esters.    the degree of unsaturation can be estimated by the following experiment. 4 drops of  the oil are dissolved in 5  cm3 of ethanol. dilute bromine water is added a drop at a time  until the brown colour no longer disappears. enough bromine has been added to the sample to react with all the double bonds.    cooking  product mass of saturated fat in  100  g of product  / g mass of  unsaturated fat in  100  g of product  / g number of drops of  bromine water  margarine 35 35 5  butter 45 28 4  corn oil 10 84 12  soya oil 15 70 10       lard 38 56         (i) complete the one blank space in the table. [1]    (ii) complete the equation for bromine reacting with a double bond.    c c +   br 2   [2]    (iii) using saturated fats in the diet is thought to be a major cause of heart disease. which of the products is the least likely to cause heart disease?   [1]   ",
            "13": "13  \u00a9 ucles 2007 0620/03/m/j/07 for  examiner's  use  (d) a better way of measuring the degree of unsa turation is to find the iodine number of the  unsaturated compound. this is the mass of iodine that reacts with all the double bonds  in 100  g of the fat.    use the following information to calculate the number of double bonds in one molecule  of the fat.    mass of one mole of the fat is 884  g.     one mole of i2 reacts with one mole cc.     the iodine number of the fat is 86.2  g.    complete the following calculation.    100  g of fat reacts with 86.2  g of iodine.  884  g of fat reacts with  g of iodine.  one mole of fat reacts with  moles of iodine molecules.  number of double bonds in one molecule of fat is   [3]    [total:14]   ",
            "14": "14   0620/03/m/j/07 blank page",
            "15": "15      permission to reproduce items where third-party owned material prote cted by copyright is included has been sought and cleared w here  possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring  clearance  have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of  university of cambridge local examinations syndicate (ucles), whic h is itself a department of the university of cambridge.     0620/03/m/j/07 blank page",
            "16": "16  \u00a9 ucles 2007 0620/03/m/j/07 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s07_qp_5.pdf": {
            "1": "    this document consists of 6 printed pages and 2 blank pages.  ib07 06_0620_05/8rp  \u00a9 ucles 2007  [turn over      *6545751546* for examiner's use  1   2   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/05     paper 5  practical test  may/june 2007     1 hour 15 minutes    candidates answer on the question paper .    additional materials: as listed in instructions to supervisors      read these instructions first    write your name, centre number and candidate number in the spaces at the top of this page.  write in dark blue or black pen in the spaces provided on the question paper. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid.  do not  write in any barcodes.    answer all questions. the number of marks is given in brackets [  ] at the end of each question or part question. practical notes are provided on page 8.   ",
            "2": "2  \u00a9 ucles 2007 0620/05/m/j/07  for  examiner's  use 1 you are going to investigate the reaction between sodium thiosulphate and potassium  iodate.    read all the instructions below carefully before  starting the two experiments.     instructions      experiment 1    fill the burette provided up to the 0.0  cm3 mark with the solution of sodium thiosulphate. by  using a measuring cylinder, pour 20  cm3 of the solution a of potassium iodate into the  conical flask provided. add 10  cm3 of dilute sulphuric acid into the flask and 1  g of potassium  iodide. swirl the flask to mix the contents.    from the burette add the sodium thiosulphate solution to the flask and swirl to mix  thoroughly. when the contents of the flask are yellow, add 1  cm3 of starch solution to the  flask. continue to add sodium thiosulphate solution slowly to the flask until the solution  becomes colourless. record the burette readings in the table.    experiment 2    pour away the contents of the flask and rinse with distilled water. fill the burette up to the  0.0  cm3 mark with the solution of sodium thiosulphate. repeat experiment 1 exactly, using  solution b of potassium iodate instead of solution a. record your burette readings and  complete the table.     normally you would be required to carry out repeat titrations. however, owing to time  considerations you are only required to carry out one titration for each experiment.      table of results     burette readings  / cm3     experiment 1 experiment 2  final reading    initial reading    difference       [6] ",
            "3": "3  \u00a9 ucles 2007 0620/05/m/j/07 [turn over  for  examiner's  use  (a) describe the appearance of the solution in the conical flask before adding the sodium  thiosulphate solution.   [1]      (b) what happens to the colour of the solution in the flask as the sodium thiosulphate  solution is added?   [1]    (c) (i)  what was the colour change when the starch was added to the flask?  from  to  [2]    (ii) suggest why the starch was used.   [1]       (d) (i)  in which experiment was the greatest volume of sodium thiosulphate solution  used?   [1]     (ii) compare the volumes of sodium thiosulphate solution used in experiments 1 and  2.   [1]    (iii) suggest an explanation for the difference in the volumes.     [2]       (e) predict the volume of sodium thiosulphate solution which would be needed to react  completely with 10  cm3 of solution b.     [2]       (f) explain one change you could make to the experimental method  to obtain more  accurate results, without changing the apparatus.  change   explanation  [2]      [total:19]",
            "4": "4  \u00a9 ucles 2007 0620/05/m/j/07  for  examiner's  use 2 you are provided with a sample of solid c which is a mixture of two salts, d and e. solid d  is insoluble in water and solid e is water-soluble.   carry out the following tests on c, recording all of your observations in the table. do not  write any conclusions in the table.    tests observations      [1] (a) describe the appearance of c.     ph  [2]      [1]     (b) using a spatula, place a little of c in a hard glass test-tube. inside the top of the tube  suspend a piece of damp  indicator paper. heat c gently  until gas comes out of the tube.          leave the tube to cool and  study its appearance.      [2]       (c) using a spatula, place a little of c in a test-tube. add about     2  cm3 of dilute nitric acid and  test the gas.   add the rest of solid c to a boiling tube containing 10  cm3 of distilled water.  stopper the tube and shake the contents gently for 2 minutes. filter the contents of the boiling tube. keep both the filtrate and the residue on the filter paper in the funnel.   carry out the following tests, recording all your observations in each case.  tests on the residue in the filter paper observations         [2]   (d) place the funnel in a test-tube.  pour about 3  cm3 of dilute nitric  acid onto the residue contained  in the funnel. add about 2  cm3 of  potassium iodide to the solution  collected in the tube.  ",
            "5": "5  \u00a9 ucles 2007 0620/05/m/j/07 [turn over  for  examiner's  use tests on the filtrate observations     (e) divide the filtrate from c into  three test-tubes.     (i) to the first portion,  add a few drops of dilute hydrochloric  acid and about 1  cm3  of aqueous barium  nitrate.  [2]   [2]  (ii) to the second portion of filtrate, add excess aqueous ammonia and shake.    (iii) to the third portion of  filtrate, add an equal  volume of aqueous sodium hydroxide.  [1]        warm the mixture  gently. test the gas with indicator paper.     [2]     (f) what conclusions can you draw about salt d?   [2]     (g) what conclusions can you draw about salt e?     [4]      [total:21]",
            "6": "6   0620/05/m/j/07 blank page",
            "7": "7      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2007 0620/05/m/j/07 blank page",
            "8": "8  \u00a9 ucles 2007 0620/05/m/j/07  notes for use in qualitative analysis     test for anions     anion test test result  carbonate (co2 3-) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then aqueous lead( ii) nitrate yellow ppt.  nitrate (no\u2212 3)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulphate (so2 4-)  [in solution] acidify with dilute nitric acid, then aqueous barium nitrate white ppt.    test for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh4+) ammonia produced on warming -  calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt.  copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution    test for gases     gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_s07_qp_6.pdf": {
            "1": "    this document consists of 13 printed pages and 3 blank pages.  ib07 06_0620_06/8rp  \u00a9 ucles 2007  [turn over      *9863619676* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/06     paper 6  alternative to practical  may/june 2007     1 hour    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your name, centre number and candidate number at the top of this page.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid.  do not  write in any barcodes.    answer all questions.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2007 0620/06/m/j/07  for  examiner's  use 1 a mixture of ethanol and water can be separated by fractional distillation. the apparatus  below can be used to carry out such a separation in the laboratory.    heata b cd     (a) name each piece of apparatus.    a   b   c  [3]       (b) what is the purpose of d?   [1]       (c) how could the purity of the ethanol collected be checked?   [1]      [total: 5]",
            "3": "3  \u00a9 ucles 2007 0620/06/m/j/07 [turn over  for  examiner's  use 2 concentrated hydrochloric acid can be electrolysed using the apparatus shown.         (a) label the position of the electrodes on the diagram. [1]     (b) give two observations when the circuit is switched on.  1   2  [2]      (c) (i) name the product at the positive electrode.   [1]     (ii) state a test for this product and the result of the test.  test   result  [2]       [total: 6]",
            "4": "4  \u00a9 ucles 2007 0620/06/m/j/07  for  examiner's  use 3 chromatography can be used to identify amino acids from a sample of protein.     the diagram shows the chromatogram obtained when four samples of amino acids were  analysed. the paper was sprayed with ninhydrin.    1 2 34 original positions of samples of amino acidsoriginchromatography papersolvent front level of solvent      (a) why is the origin line drawn in pencil?   [1]      (b) which amino acids could possibly be the same?   [1]     (c) which amino acid sample contains more than one amino acid? explain your answer.  sample   explanation    [2]       (d) suggest why it is necessary to spray the chromatogram with ninhydrin.   [1]      [total: 5]",
            "5": "5  \u00a9 ucles 2007 0620/06/m/j/07 [turn over  for  examiner's  use 4 a student investigated the reaction between sodium thiosulphate and potassium iodate.     two experiments were carried out.     experiment 1    a burette was filled up to the 0.0  cm3 mark with sodium thiosulphate solution. by using a  measuring cylinder, 20  cm3 of solution a of potassium iodate was placed into a conical  flask. dilute sulphuric acid and potassium iodide were also added to the flask. the flask was shaken to mix the contents and produce a red solution of iodine.    the sodium thiosulphate solution was added to the flask. when the contents of the flask  were yellow, 1  cm3 of starch solution was added to the flask. addition of sodium  thiosulphate to the flask was continued until the solution turned colourless. use the burette  diagram to record the final volume in the table and complete the column in the table of results on page 6.        38 3940          experiment 2   experiment 1 was repeated using a different solution of potassium iodate, solution b. use  the burette diagrams to record the volumes and complete the table on page 6.      8 910282930 initial final    ",
            "6": "6  \u00a9 ucles 2007 0620/06/m/j/07  for  examiner's  use  table of results    burette readings  / cm3   experiment 1 experiment 2  final reading    initial reading 0.0 8.1  difference     [4]     (a) suggest why the starch was used.   [1]      (b) (i) in which experiment was the greatest volume of sodium thiosulphate solution  used?   [1]    (ii) compare the volumes of sodium thiosulphate solution used in experiments 1 and 2.   [1]    (iii) suggest an explanation for the difference in the volumes.     [2]      (c) predict the volume of sodium thiosulphate solution which would be needed to react completely with 10  cm3 of solution b.     [2]      (d) explain one change that could be made to the experimental method  to obtain more  accurate results, without changing the apparatus.  change   explanation  [2]     [total: 13]",
            "7": "7  \u00a9 ucles 2007 0620/06/m/j/07 [turn over  for  examiner's  use 5 a sample of solid c was analysed. c is a mixture of two salts, d and e. solid d is insoluble  lead carbonate and solid e is water-soluble.   the tests on c, and some of the observations are in the following table.   complete the observations in the table.    tests observations     pale green solid  (a) describe the appearance of c.     paper turns blue   ph 8 to 11    (b) using a spatula, place a little of c  in a hard glass test-tube. inside the top of the tube suspend a  piece of damp indicator paper.  heat c gently until gas comes  out of the tube.         [3]     (c) using a spatula, place a little of c  in a test-tube. add about    2  cm3 of dilute nitric acid and test  the gas.     solid c was added to a boiling tube containing distilled water. the tube was  shaken to mix the contents. the contents of the boiling tube were filtered.  tests on the residue in the filter paper observations         [2]   (d) place the funnel in a test-tube.  pour dilute nitric acid onto the  residue contained in the funnel.  add 2  cm3 of potassium iodide to  the solution collected in the tube.  ",
            "8": "8  \u00a9 ucles 2007 0620/06/m/j/07  for  examiner's  use  tests on the filtrate observations     (e) divide the filtrate into three test- tubes.      (i) to the first portion add  dilute hydrochloric acid  and about 1  cm3 of  aqueous barium  nitrate. white precipitate   green precipitate     (ii) to the second portion of  solution add excess aqueous ammonia.    (iii) to the third portion of solution, add an equal  volume of aqueous  sodium hydroxide. green precipitate   paper turned blue   warm the mixture  gently. test the gas  with indicator paper.  ph 8 to 11       (f) name the gas given off in (c).   [1]     (g) name the gas given off in (e)(iii) .   [1]     (h) what conclusions can you draw about salt e?       [4]      [total: 11]",
            "9": "9  \u00a9 ucles 2007 0620/06/m/j/07 [turn over  for  examiner's  use 6 hydrogen peroxide breaks down to form oxygen.     the volume of oxygen given off can be measured using the apparatus below.      gas syringe01 02 03 04 05 0        solids w and x both catalyse the breakdown of hydrogen peroxide. the syringe diagrams  show the volume of oxygen formed every 20 seconds using these catalysts at 25  \u00b0c.       time  / s using catalyst w using catalyst x 01 02 03 04 0 01 02 03 04 001 02 03 04 001 02 03 04 001 02 03 04 001 02 03 04 001 02 03 04 001 02 03 04 001 02 03 04 001 02 03 04 001 02 03 04 0 0 20 406080 10001 02 03 04 0       ",
            "10": "10  \u00a9 ucles 2007 0620/06/m/j/07  for  examiner's  use  (a) use the gas syringe diagrams to complete the table.    volume of oxygen  / cm3  time  / s  catalyst w catalyst x  0    20    40    60    80    100       [3]   ",
            "11": "11  \u00a9 ucles 2007 0620/06/m/j/07 [turn over  for  examiner's  use  (b) plot a graph to show each set of results. clearly label the curves.    0 2 04 06 08 0 1 0 0 time  / s     [6]     (c) which solid is the better catalyst in this reaction? give a reason for your choice.  solid   reason    [2]     ",
            "12": "12  \u00a9 ucles 2007 0620/06/m/j/07  for  examiner's  use  (d) why is the final volume of oxygen the same in each experiment?   [1]      (e) sketch a line on the grid to show the shape of the graph you would expect if the  reaction with catalyst x was repeated at 40  \u00b0c. [2]      [total: 14]",
            "13": "13  \u00a9 ucles 2007 0620/06/m/j/07 for  examiner's  use 7 when cement powder is added to water a reaction takes place.     (a) describe an experiment to show that this reaction is exothermic.             [4]      (b) how could you show that the solution contains calcium ions?     [2]     [total: 6]   ",
            "14": "14   0620/06/m/j/07 blank page",
            "15": "15   0620/06/m/j/07 blank page",
            "16": "16    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/06/m/j/07  blank page  "
        },
        "0620_w07_qp_1.pdf": {
            "1": "    this document consists of 18 printed pages and 2 blank pages.  ib07 11_0620_01/4rp  \u00a9 ucles 2007  [turn over      *7620553924* university of cambridge international examinations  international general certificate of secondary education        chemistry 0620/01     paper 1 multiple choice  october/november 2007      45 minutes    additional materials: multiple choice answer sheet    soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil.  do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.    there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.    read the instructions on the answer sheet very carefully.    each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet.  a copy of the periodic table is printed on page 20.  you may use a calculator.       ",
            "2": "2    \u00a9 ucles 2007 0620/01/o/n/07 1 oxides of nitrogen from car exhausts can spread through the atmosphere.    car exhaust fumes     this occurs because gas molecules move from a region of \u2026\u20261\u2026\u2026 concentration to a region of  \u2026\u20262\u2026\u2026 concentration by a process called \u2026\u20263\u2026\u2026 .  which words correctly complete the gaps?     1 2 3  a high low diffusion  b high low evaporation  c low high diffusion  d low high evaporation     2 part of the instructions in an experiment reads as follows.    quickly add 50  cm3 of acid.    what is the best piece of apparatus to use?  a a burette  b a conical flask  c a measuring cylinder  d a pipette     ",
            "3": "3    \u00a9 ucles 2007  0620/01/o/n/07  [turn over  3 the outline diagrams show three methods of separation.    xyz     what are the three methods called?     x y z  a chromatography distillation filtration  b distillation chromatography filtration  c distillation  filtration  chromatography   d filtration chromatography distillation    4 a sample of a drug is analysed by using a chemical test for aspirin and measuring its melting  point.    the chemical test is positive but the melting point is 130  \u00b0c not 135  \u00b0c as it should be.    what is correct?     the sample contains  aspirin the sample has an  impurity  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "4": "4    \u00a9 ucles 2007 0620/01/o/n/07 5 students are asked to draw a diagram of an atom with symbol x3 1.    which diagram is correct?    p nnea p n p n eb epp nnn ed c p ee proton neutronelectronnucleuskey       6 the table describes the structures of four particles.    particle number of  protons number of  neutrons number of  electrons  o 8 8 8  o2\u2013 8 8 x  na 11 y 11  na+ 11 12 z    what are the correct values of x, y and z?     x y z  a 9 11 10  b 9 11 11  c 10 12 10  d 10 12 11    7 the table shows the electronic structures of four atoms.    atom electronic structure  w 2,8,1  x 2,8,4  y 2,8,7  z 2,8,8    which two atoms combine to form a covalent compound?  a w and x b w and y c x and y d x and z     ",
            "5": "5    \u00a9 ucles 2007  0620/01/o/n/07  [turn over  8 the following statement is about chemical bonds.     covalent bonds are formed by the \u20261\u2026 of electrons. covalent substances have \u20262\u2026 electrical conductivity.    which words complete the statement?     1 2  a sharing high  b sharing low  c transfer high  d transfer low    9 a student sets up the apparatus shown. the bulb does not light.   bulb electrode water     after the student adds substance x to the water, the bulb lights.    what could x be?  a barium sulphate  b carbon (or diamond)  c copper (or graphite)  d potassium sulphate     ",
            "6": "6    \u00a9 ucles 2007 0620/01/o/n/07 10 the diagram shows a model of a molecule of an organic acid.        what is the relative molecular mass of this acid?  a 11 b 40 c 58 d 74      11 for complete combustion, one molecule of an organic compound needs 8 molecules of oxygen.    what could the formula of this compound be?  a c5h11oh  b c6h9oh  c c6h11oh  d c6h12     12 what is the charge on an anode and the type of  element formed at such an electrode?     charge on anode type of element formed  a negative metal  b negative non-metal  c positive metal  d positive non-metal    ",
            "7": "7    \u00a9 ucles 2007  0620/01/o/n/07  [turn over  13 the diagram shows how to cause a chemical change in a molten compound.    electrodes molten compound heat    what is this process used for?  a extraction of metal from its ore  b neutralisation of industrial waste c production of fertilisers d removal of oxides from metals     ",
            "8": "8    \u00a9 ucles 2007 0620/01/o/n/07 14 in which set of apparatus is the metal key electroplated with copper?     +\u2013a aqueous copper( ii) sulphate+\u2013b aqueouscopper( ii) sulphate c aqueouscopper( ii) sulphate+\u2013d aqueouscopper( ii) sulphate+\u2013= piece of copper = metal keykey       15 which substance is not used as a fuel?  a ethanol  b methane  c oxygen  d uranium      16 the mass of a beaker and its contents is plotted against time.    which graph represents what happens when sodium carbonate reacts with an excess of dilute  hydrochloric acid in an open beaker?    mass timea mass timeb mass timec mass timed 00 00 00 00     ",
            "9": "9    \u00a9 ucles 2007  0620/01/o/n/07  [turn over  17 which changes of condition slow down the reaction between magnesium and air?  1 heating the magnesium to a higher temperature  2 using a higher proportion of oxygen in the air  3 using magnesium ribbon instead of powdered magnesium    a 1 only  b 2 only  c 3 only  d 1, 2 and 3      18 dilute sulphuric acid is added to a mixture of copper, magnesium and zinc in a beaker. the  beaker is left for about 10 minutes and its contents are then filtered.    what does the filtrate contain?  a copper( ii) sulphate, magnesium sulphate and zinc sulphate   b copper( ii) sulphate and zinc sulphate only  c magnesium sulphate and zinc sulphate only   d magnesium sulphate only     19 gas x is passed into water as shown.    gas x water     the ph of the water changes from 7 to 10.    what is gas x?  a ammonia  b carbon dioxide c nitrogen d sulphur dioxide     ",
            "10": "10    \u00a9 ucles 2007 0620/01/o/n/07 20 powdered carbon and powdered copper are separately heated as shown.    air aircarbon heat copper  heat    which changes in the masses of the powders occur?     carbon copper  a decrease decrease  b decrease increase  c increase decrease  d increase increase      21 two tests are carried out on a solution containing both copper( ii) sulphate and sodium chloride.  a student records results as shown.    test reagent result  1 aqueous barium chloride blue precipitate  2 aqueous silver nitrate white precipitate    which results are correctly recorded?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "11": "11    \u00a9 ucles 2007  0620/01/o/n/07  [turn over  22 aqueous solution s is added to aqueous ammonium chloride. the mixture is heated. ammonia  gas is given off.    what could solution s contain?  a aluminium  b ammonium sulphate  c sodium chloride  d sodium hydroxide     23 rubidium is below potassium in group i of the periodic table.    \u2022 the melting point of rubidium is \u2026...1\u2026... than that of potassium.   \u2022 the reaction of rubidium with water is \u2026\u20262\u2026\u2026 than that of potassium.    which words correctly complete these statements?     1 2  a higher faster  b higher slower  c lower faster  d lower slower     24 the equation shows the reaction between a hal ogen and the aqueous ions of another halogen.    x 2 + 2y  \u2013 \u2192 2x  \u2013 + y2    what could x2 and the colour of y \u2013 be?     x2 y \u2013  a chlorine brown   b chlorine colourless   c iodine brown   d iodine colourless      ",
            "12": "12    \u00a9 ucles 2007 0620/01/o/n/07 25 the diagram shows a light bulb.    filament argon     why is argon used instead of air in the light bulb?  a argon is a good conductor of electricity.  b argon is more reactive than air.  c the filament glows more brightly.  d the filament lasts for a longer time.      26 element x exists as diatomic molecules.    in which group of the periodic table is x placed?  a group 0  b group i  c group ii  d group vii    27 which statement is correct about all metals?  a they are attracted to a magnet.  b they are weak and brittle.  c they may be used to form alloys.  d they react with water.    ",
            "13": "13    \u00a9 ucles 2007  0620/01/o/n/07  [turn over  28 the table gives information about three different metals.    metal metal oxide reduced when  heated with carbon reacts with dilute  hydrochloric acid  x \u0013 \u0017  y \u0017 \u0013  z \u0013 \u0013    what is the correct order of reactivity of these metals?     most reactive  least reactive  a x y z  b y x z  c y z x  d z x y      29 the following statements are about alloys.    \u2022 alloys are \u2026x\u2026. .  \u2022 \u2026y\u2026 alloys conduct electricity.    which words complete the statements?     x y  a compounds all  b compounds some  c mixtures all  d mixtures some      30 a piece of equipment needs to be made from a me tal that is of low density, relatively strong and  resistant to corrosion.     which metal is best suited for this?  a aluminium  b copper  c iron  d silver     ",
            "14": "14    \u00a9 ucles 2007 0620/01/o/n/07 31 some elements of the periodic table are shown shaded.    which set of shaded elements could be used with iron to make different types of steel?    a bcd       32 which of the following do not use oxygen?    1 breathing apparatus in a hospital  2 heating a room with an electric fire  3 welding apparatus    a 1 only b 2 only c 3 only d 1, 2 and 3      33 possible methods to prevent the rusting of iron are    \u2022 coat with grease,  \u2022 plate the iron with zinc,  \u2022 paint the iron.    which of these methods can easily be used to prevent the rusting of an iron girder of a bridge?     coating with grease plating with zinc painting  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0017 \u0013     ",
            "15": "15    \u00a9 ucles 2007  0620/01/o/n/07  [turn over  34 to grow roses, a fertiliser containing nitrogen,  phosphorus and potassium is needed. for a good  yield, the fertiliser should contain a high proportion of potassium.    which fertiliser is best for roses?    proportion by mass  fertiliser  n p k  a 29 5 0  b 29 15 5  c 13 13 20  d 9 0 25      35 a label on a bottle of spring water gives the following information.    contents per litre  calcium 25.0  mg  magnesium 4.5  mg  potassium 1.0  mg  sodium 6.5  mg  hydrogencarbonate 103  mg  sulphate 10.5  mg  nitrate 7.0  mg  chloride 5.5  mg    what is the total mass of singly charged positive ions in the water?  a 7.5  mg b 12.5  mg c 29.5  mg d 115.5  mg     36 when calcium carbonate is heated, compound x and a gas are formed.    what is the name of x  and what is its use?     name of x use of x  a lime to neutralise acid soil  b lime to provide nutrients for crop growth  c slaked lime to neutralise acid soil  d slaked lime to provide nutrients for crop growth     ",
            "16": "16    \u00a9 ucles 2007 0620/01/o/n/07 37 which statements about all polymers are correct?    1 they are compounds containing only carbon and hydrogen.  2 they are large molecules made from many smaller molecules.  3 they occur in nature.     1 2 3  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0017  d \u0017 \u0017 \u0013     38 properties of some organic compounds include:    1 they burn;  2 they dissolve in water;  3 they polymerise.    which of these properties does ethanol have?     1 2 3  a \u0013 \u0017 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0017 \u0013     39 which two molecules contain the same number of hydrogen atoms?  a ethane and ethanoic acid  b ethane and ethene  c ethanoic acid and ethanol  d ethanoic acid and ethene    ",
            "17": "17    \u00a9 ucles 2007  0620/01/o/n/07   40 the structures of two compounds are shown.    ch3 ch2 ch3ch ch3 ch3 ch ch2 ch2 pq    which line in the table is correct?     polymerises reacts readily  with bromine  a p p  b p q  c q p  d q q       ",
            "18": "18     0620/01/o/n/07 blank page  ",
            "19": "19      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.     0620/01/o/n/07   blank page",
            "20": "20      university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/01/o/n/07  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w07_qp_2.pdf": {
            "1": "    this document consists of 16 printed pages.  ib07 11_0620_02/5rp  \u00a9 ucles 2007  [turn over       *9241932394* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/02     paper 2  october/november 2007     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name in the spaces at the top of this page.  write in dark blue or black pen. you may need to use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2007 0620/02/o/n/07  for  examiner's  use 1 some oxides are listed below.    calcium oxide  carbon dioxide  carbon monoxide  phosphorus trioxide  sodium oxide  sulphur dioxide  water     (a) which one of these oxides is most likely to contribute to acid rain?   [1]      (b) which one of these oxides is a product of the reaction between an acid and a  carbonate?   [1]      (c) which one of these oxides is formed by the incomplete combustion of carbon?   [1]       (d) which one of these oxides is a good solvent?   [1]      (e) which one of these oxides is used to neutralise acidic industrial waste products?   [1]     (f) which two of these oxides reacts with water to form an alkaline solution?   [1]     (g) complete the diagram to show the electronic structure of water.   show hydrogen electrons by \u2018o\u2019  show oxygen electrons by \u2018x\u2019       hho\u00d7\u00d7\u00d7\u00d7       [1] ",
            "3": "3  \u00a9 ucles 2007 0620/02/o/n/07 [turn over  for  examiner's  use  (h) the structure of phosphorus trioxide is shown below.    pp oo p opooo      write the simplest  formula for phosphorus trioxide.   [1]       [total: 8]   ",
            "4": "4  \u00a9 ucles 2007 0620/02/o/n/07  for  examiner's  use 2 the diagram shows a bottle of mineral water.    top made of poly(propene) label bottle made of poly(ethene)      (a) the poly(propene) top is made by polymerising propene molecules, ch 3ch=ch 2.    (i) which one of the following best describes the propene molecules in this reaction?  put a ring around the correct answer.    alkanes   monomers  polymers products   salts      [1]    (ii) state the name of the homologous series to which propene belongs.   [1]    (iii) propene is an unsaturated hydrocarbon.   state the meaning of the following terms.   unsaturated      hydrocarbon     [2]    (iv) describe a chemical test to distinguish between an unsaturated hydrocarbon and a saturated hydrocarbon. state the results.  test   result with saturated hydrocarbon   result with unsaturated hydrocarbon  [3]     ",
            "5": "5  \u00a9 ucles 2007 0620/02/o/n/07 [turn over  for  examiner's  use  (b) the poly(ethene) bottle is made by polymerising ethene.    nch 2=ch 2 \u2014ch 2\u2013ch 2\u2014n ()     complete the following sentence about this reaction by filling in the blank space.   the formation of poly(ethene) is an example of an  polymerisation  reaction. [1]     (c) the label on the bottle lists the concentration of ions dissolved in the water in milligrams  per litre.    concentration of ions in milligrams per litre  calcium 32 nitrate 1  chloride 5 potassium 0.5  hydrogencarbonate 133 sodium 4.5  magnesium 8 sulphate 7     (i) state the name of two negative ions which appear in this list.   [1]    (ii) which metal ion in this list is present in the highest concentration?   [1]    (iii) calculate the amount of magnesium ions in 5 litres of this mineral water.             [1]     (iv) which ion in the list reacts with aqueous silver nitrate to give a white precipitate?   [1]    (v) which ion in the list gives off ammonia when warmed with sodium hydroxide and aluminium foil?   [1]     (vi) complete the equation to show the formation of a potassium ion from a potassium  atom.    k    \u2192    k+    +  [1]  ",
            "6": "6  \u00a9 ucles 2007 0620/02/o/n/07  for  examiner's  use  (d) the ph of the mineral water is 7.8.   which one of the following best describes this ph?   tick one box.   slightly acidic      slightly alkaline      neutral      very acidic      very alkaline   [1]    (e) pure water can be obtained by distilling the mineral water using the apparatus shown below.    heatflask mineral waterbeakera      (i) state the name of the piece of apparatus labelled a.   [1]    (ii) where does the pure water collect?   [1]     (iii) how does the boiling point of the mineral water in the flask compare with the boiling  point of pure water?   [1]   ",
            "7": "7  \u00a9 ucles 2007 0620/02/o/n/07 [turn over  for  examiner's  use  (f) the diagram shows how mineral water is formed. mineral water contains no bacteria or  particles of earth.    water drains through limestone mineral watersurface water soil andbacteriawater bacteria andsoil particles limestone particles      use the diagram to explain how the water is purified from bacteria and particles of earth.     [2]     [total: 20]   ",
            "8": "8  \u00a9 ucles 2007 0620/02/o/n/07  for  examiner's  use 3 this question is about metals.     (a) match up the metals in the boxes on the left with the descriptions in the boxes on the right. the first one has been done for you.    silver aluminium potassium platinum irona metal used to make aircraft bodies a metal used in jewellery a metal extracted from haematite a very soft metal an unreactive metal used for electrodes     [4]     (b) iron powder reacts rapidly with sulphuric acid to form aqueous iron( ii) sulphate and  hydrogen.    fe(s)    +    h 2so 4(aq)    \u2192    feso 4(aq)    +    h 2(g)    describe two things that you would see happening as this reaction takes place.     [2]     (c) alloys are often more useful than pure metals.     (i) complete the following sentences by filling in the blank spaces.  an alloy is a  of a metal with other elements. the properties  of  can be changed by the controlled use of additives to form  steel alloys. increasing the amount of carbon in a steel makes it  [3]     (ii) name one other alloy apart from steel.   [1]     (iii) iron rusts very easily. describe two methods of preventing rusting.  1.   2.  [2]     [total:12] ",
            "9": "9  \u00a9 ucles 2007 0620/02/o/n/07 [turn over  for  examiner's  use 4 the diagram shows the changes in ph in a student\u2019s mouth after she has eaten a sweet.    8 76543 0 1 02 03 04 05 0 time  / minutesph      (a) describe how the acidity in the student\u2019s mouth changes after she has eaten the sweet.     [2]     (b) (i) chewing a sweet stimulates the formation of saliva. saliva is slightly alkaline.   use this information to explain the shape of the graph.      [2]     (ii) state the name of the type of reaction which occurs when an acid reacts with an  alkali.   [1]     (c) many sweets contain citric acid. the formula of citric acid is shown below.    ho c ch 2ch 2co 2h co 2hco 2h      (i) put a ring around the alcohol functional group on the above formula. [1]     (ii) state the name of the \u2013 co 2h functional group in citric acid.   [1]     (iii) ethanoic acid also has a \u2013 co 2h functional group.   write down the formula for ethanoic acid.   [1]  ",
            "10": "10  \u00a9 ucles 2007 0620/02/o/n/07  for  examiner's  use  (d) citric acid can be extracted from lemon juice as follows:     stage 1: add calcium carbonate to hot lemon juice  stage 2: filter off the precipitate which is formed (calcium citrate)  stage 3: wash the calcium citrate precipitate with water   stage 4: add sulphuric acid to the calcium citrate to make a solution of citric acid   stage 5: crystallise the citric acid   (i) when calcium carbonate is added to lemon juice a fizzing is observed.   explain why there is a fizzing.   [1]     (ii) draw a diagram to show step 2. label your diagram.               [2]     (iii) suggest why the calcium citrate precipitate is washed with water.   [1]    (iv) describe how you would carry out step 5.     [1]     (v) nowadays, citric acid is usually made by the fermentation of sugars.   which one of the following is required for fermentation?   put a ring around the correct answer.   acid  high temperature  light  microorganisms nitrogen     [1]     [total: 14]     ",
            "11": "11  \u00a9 ucles 2007 0620/02/o/n/07 [turn over  for  examiner's  use 5 some coal dust was heated with copper( ii) oxide using the apparatus shown below.    heatcoal dust and copper(ii) oxideplug of damp cotton wool      (a) coal contains carbon and various hydrocarbons. the carbon reduces the copper( ii)  oxide when heated.     (i) what do you understand by the term reduction ?   [1]    (ii) at the end of the experiment a reddish-brown solid remained in the tube.   state the name of this reddish-brown solid.   [1]    (iii) the reddish brown solid conducts electricity.   how could you show that it conducts electricity?     [2]       (b) during the experiment, water collected on the cooler parts of the test tube.     (i) suggest where the hydrogen in the water comes from.   [1]     (ii) water is a liquid.   describe the arrangement and motion of the particles in a liquid.     [2]     [total: 7]     ",
            "12": "12  \u00a9 ucles 2007 0620/02/o/n/07  for  examiner's  use 6 the table below shows an early form of the periodic table made by john newlands in  1866.     h f cl co, ni br  li na k cu rb  be mg ca zn sr  b al cr y   c si ti in   n p mn as   o s fe sc      (a) newlands arranged the elements according to their relative atomic masses.   what governs the order of the elements in the modern periodic table?   [1]     (b) use your modern periodic table to suggest why newlands put cobalt and nickel in the same place.   [1]     (c) which group of elements is missing from newlands\u2019 table?   [1]       (d) describe three other  differences between newlands\u2019 table and the modern periodic  table. you must not give any of the answers you mentioned in parts (a), (b) or (c).         [3]     ",
            "13": "13  \u00a9 ucles 2007 0620/02/o/n/07 [turn over  for  examiner's  use  (e) carbon exists in two forms, graphite and diamond.    strong bonds weak forces diamond graphite= carbon atom      use ideas about structure and bonding to suggest     (i) why graphite is used as a lubricant,   [1]    (ii) why diamond is very hard.   [1]    [total: 8]    ",
            "14": "14  \u00a9 ucles 2007 0620/02/o/n/07 for  examiner's  use 7 compounds and elements vary in their volatility, solubility in water and electrical  conductivity depending on their bonding.    (a) place copper, methane and water in order of their volatility.    most volatile    \u2192    least volatile    \u2192 [1]    (b) complete the table to show the solubility in water and electrical conductivity of various solids.    solid structure soluble or  insoluble does it conduct  electricity?  silver metallic insoluble   sodium chloride ionic  no  sulphur covalent  no  copper sulphate ionic soluble     [4]    (c) the apparatus shown below is used to electrolyse concentrated aqueous sodium  chloride.    + \u2013electrode a electrode bconcentrated aqueous sodium chloride      (i) suggest a suitable substance which could be used for the electrodes.   [1]     (ii) state the name of the gas given off  at electrode a,   at electrode b.  [2]   ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of  university of cambridge local examinations syndicate (ucles), whic h is itself a department of the university of cambridge.    \u00a9 ucles 2007 0620/02/o/n/07  for  examiner's  use   (iii) state the name given to electrode a.   [1]    (iv) explain why aqueous sodium chloride conducts electricity but solid sodium  chloride does not.     [2]     [total: 11]    ",
            "16": "16  \u00a9 ucles 2007 0620/02/o/n/07 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w07_qp_3.pdf": {
            "1": "    this document consists of 13 printed pages and 3 blank pages.  ib07 11_0620_03/8rp  \u00a9 ucles 2007  [turn over       *3664092880* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/03     paper 3 (extended)  october/november 2007     1 hour 15 minutes   candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen.  you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  questions.   ",
            "2": "2  \u00a9 ucles 2007 0620/03/o/n/07  for  examiner's  use 1 a list of techniques used to separate mixtures is given below.    fractional   distillation   simple  distillation   crystallization   filtration   diffusion      from the list choose the most suitable technique to separate the following.  water from aqueous copper( ii) sulphate   helium from a mixture of helium and argon   copper( ii) sulphate from aqueous copper( ii) sulphate   ethanol from aqueous ethanol   barium sulphate from a mixture of water and barium sulphate  [5]     [total: 5]",
            "3": "3  \u00a9 ucles 2007 0620/03/o/n/07 [turn over  for  examiner's  use 2 the table below gives the number of protons, neutrons and electrons in atoms or ions.    particle number of  protons number of  electrons number of neutrons symbol or  formula  a 9 10 10 19 9-f  b 11 11 12   c 18 18 22   d 15 18 16   e 13 10 14      (a) complete the table. the first line is given as an example. [6]      (b) which atom in the table is an isotope of the atom which has the composition 11p, 11e and 14n? give a reason for your choice.     [2]     [total: 8]     ",
            "4": "4  \u00a9 ucles 2007 0620/03/o/n/07  for  examiner's  use 3 magnesium reacts with bromine to form magnesium bromide.     (a) magnesium bromide is an ionic compound. draw a diagram that shows the formula of the compound, the charges on the ions and the arrangement of outer electrons around the negative ion.   the electron distribution of a bromine atom is 2, 8, 18, 7.                use x to represent an electron from a magnesium atom.  use o to represent an electron from a bromine atom. [3]      (b) in the lattice of magnesium bromide, the ratio of magnesium ions to bromide ions is 1:2.    (i) explain the term lattice.     [2]     (ii) explain why the ratio of ions is 1:2.   [1]     (iii) the reaction between magnesium and bromine is redox. complete the sentences.  magnesium is the  agent because it has   electrons.    bromine has been  because it has   electrons. [4]     [total: 10]   ",
            "5": "5  \u00a9 ucles 2007 0620/03/o/n/07 [turn over  for  examiner's  use 4 zinc is extracted from zinc blende, zns.     (a) zinc blende is heated in air to give zinc oxide and sulphur dioxide. most of the sulphur dioxide is used to make sulphur trioxide. this is used to manufacture sulphuric acid. some of the acid is used in the plant, but most of it is used to make fertilisers.    (i) give another use of sulphur dioxide.   [1]     (ii) describe how sulphur dioxide is converted into sulphur trioxide.       [3]     (iii) name a fertiliser made from sulphuric acid.   [1]      (b) some of the zinc oxide was mixed with an excess of carbon and heated to 1000  \u00b0c.  zinc distils out of the furnace.    2zno   +   c      2zn   +   co 2  c   + co 2  \u2192  2co     (i) name the two changes of state involved in the process of distillation.   [2]     (ii) why is it necessary to use an excess of carbon?     [2]  ",
            "6": "6  \u00a9 ucles 2007 0620/03/o/n/07  for  examiner's  use (c) the remaining zinc oxide reacts with sulphuric acid to give aqueous zinc sulphate. this  is electrolysed with inert electrodes (the electrolysis is the same as that of     copper( ii) sulphate with inert electrodes).   ions present:   zn2+(aq)   so 42-(aq)   h+(aq)   oh-(aq)    (i) zinc forms  at the negative electrode (cathode). write the equation for this reaction.   [1]     (ii) write the equation for the reaction at the positive electrode (anode).   [2]     (iii) the electrolyte changes from aqueous zinc sulphate to   [1]    (d) give two uses of zinc.  1.    2.  [2]     [total: 15]     ",
            "7": "7  \u00a9 ucles 2007 0620/03/o/n/07 [turn over  for  examiner's  use 5 methylamine, ch 3nh 2, is a weak base. its properties are similar to those of ammonia.     (a) when methylamine is dissolved in water, the following equilibrium is set up.    ch3nh2 + h2oc h3nh3 + oh\u2013 + base acid    (i) suggest why the arrows are not the same length.   [1]    (ii) explain why water is stated to behave as an acid and methylamine as a base.     [2]       (b) an aqueous solution of the strong base, sodium hydroxide, is ph 12. predict the ph of  an aqueous solution of methylamine which has the same concentration. give a reason for your choice of ph.     [2]      (c) methylamine is a weak base like ammonia.    (i) methylamine can neutralise acids.    2ch 3nh 2   +   h 2so 4 \u2192 (ch 3nh 3)2 so 4   methylammonium sulphate     write the equation for the reaction between methylamine and hydrochloric acid.  name the salt formed.     [2]     (ii) when aqueous methylamine is added to aqueous iron( ii) sulphate, a green  precipitate is formed. what would you see if iron( iii) chloride solution had been  used instead of iron( ii) sulphate?   [1]    (iii) suggest the name of a reagent that will displace methylamine from one of its salts,  for example methylammonium sulphate.   [1]     [total: 9]   ",
            "8": "8  \u00a9 ucles 2007 0620/03/o/n/07  for  examiner's  use 6 the alcohols form a homologous series. the first four members are methanol, ethanol,  propan-1-ol and butan-1-ol.    (a) one characteristic of a homologous series is that the physical properties vary in a predictable way. the table below gives t he heats of combustion of the first three  alcohols.    alcohol formula heat of combustion in kj  / mol  methanol ch 3oh -730  ethanol ch 3-ch 2-oh -1370  propan-1-ol ch 3-ch 2-ch 2-oh -2020  butan-1-ol ch 3-ch 2-ch 2-ch 2-oh     (i) the minus sign indicates that there is less chemical energy in the products than in the reactants. what form of energy is given out by the reaction?   [1]     (ii) is the reaction exothermic or endothermic?   [1]     (iii) complete the equation for the complete combustion of ethanol.  c2h5oh  +    o2 \u2192    +   [2]   ",
            "9": "9  \u00a9 ucles 2007 0620/03/o/n/07 [turn over  for  examiner's  use  (iv) determine the heat of combustion of butan-1-ol by plotting the heats of combustion  of the first three alcohols against the number of carbon atoms per molecule.    \u2013700 \u2013800\u2013900 \u20131000\u20131100\u20131200\u20131300\u20131400\u20131500\u20131600\u20131700\u20131800\u20131900\u20132000\u20132100\u20132200\u20132300\u20132400\u20132500\u20132600\u20132700\u201328001234number of carbon atoms per molecule heat of combustion  /  kj  / mol     the heat of combustion of butan-1-ol =  kj / mol [3] ",
            "10": "10  \u00a9 ucles 2007 0620/03/o/n/07  for  examiner's  use  (v) describe two other characteristics of homologous series.     [2]     (b) give the name and structural formula of an isomer of propan-1-ol.   structural formula           name  [2]    (c) methanol is made from carbon monoxide.    co(g)  +  2h 2(g)    ch 3oh(g)             the forward reaction is exothermic     (i) describe how hydrogen is obtained from alkanes.     [2]     (ii) suggest a method of making carbon monoxide from methane.   [2]     (iii) which condition, high or low pressure, would give the maximum yield of methanol? give a reason for your choice.  pressure   reason  [2]     (d) for each of the following predict the name of the organic product.     (i) reaction between methanol and ethanoic acid   [1]    (ii) oxidation of propan-1-ol by potassium dichromate( vi)   [1]     (iii) removal of h 2o from ethanol (dehydration)   [1]     [total: 20]",
            "11": "11  \u00a9 ucles 2007 0620/03/o/n/07 [turn over  for  examiner's  use 7 (a)  a small piece of marble, calcium carbonate, was added to 5  cm3 of hydrochloric acid at  25  \u00b0c. the time taken for the reaction to stop was measured.    caco 3(s)  +  2hc l(aq) \u2192 cac l2(aq)  +  co 2(g)  +  h 2o(l)     similar experiments were performed always using 5  cm3 of hydrochloric acid.    experiment number of  pieces of  marble concentration of acid  in mol  / dm3 temperature  / \u00b0c time  / min  1 1 1.00 25 3  2 1 0.50 25 7  3 1 piece  crushed 1.00 25 1  4 1 1.00 35 2    explain each of the following in terms of collisions between reacting particles.      (i) why is the rate in experiment 2 slower than in experiment 1?     [2]     (ii) why is the rate in experiment 3 faster than in experiment 1?     [2]     (iii) why is the rate in experiment 4 faster than in experiment 1?     [2]     ",
            "12": "12  \u00a9 ucles 2007 0620/03/o/n/07  for  examiner's  use  (b) an alternative method of measuring the rate of this reaction would be to measure the  volume of carbon dioxide produced at regular intervals.    (i) sketch this graph    volume time    [2]    (ii) one piece of marble, 0.3  g, was added to 5  cm3 of hydrochloric acid, concentration  1.00  mol  / dm3. which reagent is in excess? give a reason for your choice.  mass of one mole of caco 3 = 100  g  number of moles of caco 3 =   number of moles of hc l =   reagent in excess is   reason  [4]    (iii) use your answer to (ii) to calculate the maximum volume of carbon dioxide  produced measured at r.t.p.   [1]    [total: 13] ",
            "13": "13   0620/03/o/n/07  blank page",
            "14": "14   0620/03/o/n/07  blank page",
            "15": "15    permission to reproduce items where third-party owned material prote cted by copyright is included has been sought and cleared w here  possible. every reasonable effort has been made by the publisher ( ucles) to trace copyright holders, but if any items requiring  clearance  have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name  of university of cambridge local examinations syndicate (ucles), w hich is itself a department of the university of cambridge.     0620/03/o/n/07  blank page",
            "16": "16   0620/03/o/n/07  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w07_qp_5.pdf": {
            "1": "    this document consists of 7 printed pages and 1 blank page.  ib07 11_0620_05/9rp  \u00a9 ucles 2007  [turn over      *1043157493* for examiner's use  1   2   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/05     paper 5 practical test  october/november 2007     1 hour 15 minutes    candidates answer on the question paper .    additional materials: as listed in confidential instructions      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcode.   answer all questions.  practical notes are provided on page 8.   at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part question.   ",
            "2": "2  \u00a9 ucles 2007 0620/05/o/n/07  for  examiner's  use 1 you are going to investigate what happens when dilute hydrochloric acid reacts with two  different solids, calcium carbonate (marble) and calcium oxide.    read all the instructions below carefully before  starting the two experiments.     instructions      experiment 1     place a polystyrene cup in the beaker provided.   by using a measuring cylinder, pour 50  cm3 of dilute hydrochloric acid into the polystyrene  cup and record the temperature of the acid in the table.   add the 2.5  g of small marble chips provided to the cup and stir the mixture with the  thermometer. measure and record the temperature of the mixture after 2 minutes. pour the mixture away and rinse the polystyrene cup.     experiment 2    repeat experiment 1 using 2.5  g of the powdered calcium carbonate provided. record your  results in the table.     experiment 3    repeat experiment 1 using 1.5  g of the lumps of calcium oxide provided. record your  results in the table.    experiment 4   repeat experiment 1 using the 1.5  g of the powdered calcium oxide provided. record your  results in the table.    table of results  temperature  / \u00b0c  experiment   initial final difference  1     2     3     4       [7]   ",
            "3": "3  \u00a9 ucles 2007 0620/05/o/n/07 [turn over  for  examiner's  use  (a) what did you observe in experiment 2?   [2]      (b) draw a bar chart of the results of the experiments on the grid below.    experiment numbertemperature difference  / \u00b0c     [3]       (c) which experiment produced    (i) the smallest temperature change,   [1]    (ii) the largest temperature change?   [1]   ",
            "4": "4  \u00a9 ucles 2007 0620/05/o/n/07  for  examiner's  use  (d) give two reasons why the temperature changes in (c) are different.  1.     2.    [2]      (e) in experiment 2 which reactant is in excess ? explain your answer.       [2]      (f) explain how the temperature changes would differ in the experiments if 100  cm3 of  hydrochloric acid were used.       [2]     [total: 20]   ",
            "5": "5  \u00a9 ucles 2007 0620/05/o/n/07 [turn over  for  examiner's  use 2 you are provided with four different liquids p, q, r and s.   carry out the following tests on the liquids, recording all of your observations and  deductions in the table. do not write any conclusions in the table.    tests  observations and deductions   p colour    ph   q colour    ph    r colour    ph    s colour    ph  [2]   (a) test the ph of the liquids using  indicator paper. note the colour  of the paper.         [3]    (b) (i) add a 5  cm piece of  magnesium to about 3  cm3 of  liquid p in a test\u2013tube.    test the gas given off.  q    r    s  [2]    (ii) repeat (b)(i)  using liquids  q, r and s.    do not test for any gases.  ",
            "6": "6  \u00a9 ucles 2007 0620/05/o/n/07  for  examiner's  use tests  observations and deductions          [3]  (c) to about 2  cm3 of liquid s add 1  spatula measure of sodium  carbonate.    test the gas given off.   [2]  (d) by using a teat pipette add  aqueous silver nitrate to about    1  cm3 of liquid p.     [2]   (e) by using a teat pipette add  liquid q to about 1  cm3 of  aqueous iron( ii) sulphate.      (f) name the gas given off in test (b)(i) .   [1]     (g) name the gas given off in test (c).   [1]      (h) identify liquid p.   [1]      (i) what conclusions can you draw about liquid q?     [2]      (j) what conclusion can you draw about liquid r?   [1]    [total: 20]   ",
            "7": "7   0620/05/o/n/07 blank page",
            "8": "8      permission to reproduce items where third-party owned material prote cted by copyright is included has been sought and cleared w here  possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring  clearance  have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name  of university of cambridge local examinations syndicate (ucles), w hich is itself a department of the university of cambridge.    \u00a9 ucles 2007 0620/05/o/n/07 notes for use in qualitative analysis     test for anions     anion test test result  carbonate (co 32\u2212) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then  aqueous lead( ii) nitrate yellow ppt.  nitrate (no 3\u2212)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulphate (so 42\u2212)  [in solution] acidify with dilute nitric acid, then aqueous barium nitrate white ppt.    test for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving a colourless solution white ppt., insoluble in excess  ammonium (nh 4+) ammonia produced on warming -  calcium (ca2+) white., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving a colourless solution    test for gases     gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_w07_qp_6.pdf": {
            "1": "    this document consists of 13 printed pages and 3 blank pages.  ib07 11_0620_06/6rp  \u00a9 ucles 2007  [turn over       *7279389372* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/06     paper 6 alternative to practical  october/november 2007     1 hour    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.    answer all questions.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2007 0620/06/o/n/07  for  examiner's  use 1 hydrated copper sulphate crystals, cuso 4.5h 2o were heated in the apparatus shown  below.    ice      (a) indicate on the diagram using arrows     (i) where the copper sulphate crystals are placed,    (ii) where heat is applied. [2]    (b) what is the purpose of the ice?   [1]      (c) the crystals changed colour from  to  [2]      [total: 5]",
            "3": "3  \u00a9 ucles 2007 0620/06/o/n/07 [turn over  for  examiner's  use 2 an experiment was set up to investigate the rusting of iron.    150  mm125  mmair before rustingair after rusting waterdamp iron filings      (a) describe the appearance of the iron after rusting.   [1]      (b) (i) why does the water rise up the tube?   [1]     (ii) calculate the percentage change in the volume of air in the tube.   [1]     (c) what difference would be observed if     (i) an iron nail was suspended in the tube instead of using iron filings,   [1]     (ii) the water contained salt?   [1]       [total: 5]",
            "4": "4  \u00a9 ucles 2007 0620/06/o/n/07  for  examiner's  use 3 the information in the box is about the preparation of zinc nitrate crystals.      step 1: add a small amount of zinc oxide to some hot dilute nitric acid, and stir.  step 2: keep adding zinc oxide until it is in excess .  step 3: remove the excess zinc oxide to leave colourless zinc nitrate solution.  step 4: evaporate the zinc nitrate solution until it is saturated .  step 5: leave the saturated  solution  to cool. white crystals form on cooling.  step 6: remove the crystals from the remaining solution.  step 7: dry the crystals on a piece of filter paper.      (a) suggest a reason for using excess  zinc oxide in step 2.     [1]       (b) suggest how the excess  zinc oxide can be removed from the solution in step 3.   [1]      (c) (i) what is meant by the term saturated solution ?     [2]     (ii) what practical method could show the solution to be saturated?     [1]      (d) why are the crystals dried in step 7 using filter paper instead of by heating?     [1]      [total: 6]",
            "5": "5  \u00a9 ucles 2007 0620/06/o/n/07 [turn over  for  examiner's  use 4 a student investigated the reaction of dilute hydrochloric acid with two different solids,  calcium carbonate (marble) and calcium oxide.   four experiments were carried out.   experiment 1     by using a measuring cylinder, 50  cm3 of dilute hydrochloric acid was poured into a  polystyrene cup and the initial temperature of the acid was measured.   2.5  g of small marble chips were added to the cup and the mixture stirred with the  thermometer.   the temperature of the mixture was measured after 2 minutes.   use the thermometer diagrams to record the temperatures in the table of results on page 6 .    20 1015 initial temperature  / \u00b0c20 1015 final temperature  / \u00b0c     experiment 2    experiment 1 was repeated using 2.5  g of powdered calcium carbonate. use the  thermometer diagrams to record the results in the table.    30 2025 initial temperature  / \u00b0c30 2025 final temperature  / \u00b0c     experiment 3     experiment 1 was repeated using 1.5  g of lumps of calcium oxide. use the thermometer  diagrams to record the temperatures in the table.    20 1015 initial temperature  / \u00b0c30 2025 final temperature  / \u00b0c   ",
            "6": "6  \u00a9 ucles 2007 0620/06/o/n/07  for  examiner's  use  experiment 4     experiment 1 was repeated using 1.5  g of powdered calcium oxide.   use the thermometer diagrams to record the results in the table.   30 2025 initial temperature  / \u00b0c50 4045 final temperature  / \u00b0c     table of results     temperature  / \u00b0c  experiment   initial  final difference   1     2     3     4       [4]     (a) what would be observed in experiment 2?   [1]    ",
            "7": "7  \u00a9 ucles 2007 0620/06/o/n/07 [turn over  for  examiner's  use  (b) draw a bar chart of the results of the experiments on the grid below.    experiment numbertemperature difference  / \u00b0c      [3]     (c) which experiment produced    (i) the smallest temperature change,   [1]    (ii) the largest temperature change?   [1]     (d) give two reasons why the temperature changes are different in (c).  1.     2.    [2]  ",
            "8": "8  \u00a9 ucles 2007 0620/06/o/n/07  for  examiner's  use  (e) in experiment 1, how would you know which reactant is in excess ? explain your  answer.       [2]      (f) explain how the temperature changes would differ in the experiments if 100  cm3 of  hydrochloric acid were used.       [2]     [total: 16] ",
            "9": "9  \u00a9 ucles 2007 0620/06/o/n/07 [turn over  for  examiner's  use 5 three different liquids p, q and r were analysed. q was an aqueous solution of sodium  hydroxide.   the tests on the liquids and some of the observations are in the following table.   complete the observations in the table.   tests  observations   p colour red   ph   1  q colour    ph  [2]  r colour orange   ph   5   (a) test the ph of the liquids using  indicator paper. note the colour of the paper.  bubbles of gas   lighted splint pops       (b) (i) add a 5  cm piece of  magnesium to about 3  cm3  of liquid p in a test\u2013tube.     test the gas given off.  q    r  [2]     (ii) repeat (b)(i)  using liquids  q, and r.    do not test for any gases.  ",
            "10": "10  \u00a9 ucles 2007 0620/06/o/n/07  for  examiner's  use  tests  observations          [3]  (c) to about 2  cm3 of liquid p add 1  spatula measure of sodium  carbonate.    test the gas given off.   (d) by using a teat pipette add  aqueous silver nitrate to about    1  cm3 of liquid p.   white precipitate     [2]   (e) by using a teat pipette add liquid q to about 1  cm3 of  aqueous iron( ii) sulphate.     ( f) name the gas given off in test (b)(i) .   [1]     (g) name the gas given off in test (c).   [1]     (h) identify liquid p.   [1]       (i) what conclusions can you draw about liquid r?     [2]       [total: 14]",
            "11": "11  \u00a9 ucles 2007 0620/06/o/n/07 [turn over  for  examiner's  use 6 magnesium reacts with dilute sulphuric acid to form hydrogen gas. the speed of the  reaction was investigated using the apparatus below.    magnesium waterdilute sulphuric acid measuring cylinder      in an experiment 50  cm3 of dilute sulphuric acid was added to a large piece of magnesium.  a student measured the total volume of gas produced at 2 minute intervals.     use the measuring cylinder diagrams to complete the table.  time  / minutesmeasuring cylinder diagramtotal volume of collected  / cm3 0 2468 100 5 10 10 15 20 25 30 35 25 30 35 35 40 45 1240 45 5040 45 50    [3] ",
            "12": "12  \u00a9 ucles 2007 0620/06/o/n/07  for  examiner's  use  (a) plot the student\u2019s results on the grid. use the points to draw a smooth line graph.    50 40302010 0 02468 1 0 1 2 time  / minutestotal volume of gas  / cm3      [3]     (b) (i) at which time does the result appear to be inaccurate?   [1]     (ii) use the graph to deduce what the correct volume should be at this time.   [1]     [total:8]",
            "13": "13  \u00a9 ucles 2007 0620/06/o/n/07 for  examiner's  use 7 diesel is a liquid fuel obtained from crude oil. biodiesel is a fuel made from oil obtained  from the seeds of plants such as sunflowers.    using the apparatus below plan an experiment to investigate which of these two fuels  produces more energy.    25  cm3 water spirit burnertest  - tubethermometer                    [6]       [total: 6]",
            "14": "14   0620/06/o/n/07 blank page",
            "15": "15   0620/06/o/n/07 blank page",
            "16": "16    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. ca mbridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/06/o/n/07 blank page "
        }
    },
    "2008": {
        "0620_s08_qp_1.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib08 06_0620_01/rp  \u00a9 ucles 2008  [turn over      *8469352397* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/01     paper 1 multiple choice  may/june 2008       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2008 0620/01/m/j/08  1 a yellow precipitate is formed in the experiment shown.    flat dish containing distilled water yellow precipitate forms after a few minutesfive drops ofaqueous lead(ii) nitratefive drops of aqueous potassium iodide     how is the precipitate formed?  a particles collide, diffuse and then react.  b particles collide, react and then diffuse.  c particles diffuse, collide and then react.  d particles diffuse, react and then collide     2 a student is asked to measure the time taken for 4.00  g of magnesium carbonate to react  completely with 25.0  cm3 (an excess) of dilute hydrochloric acid.    which pieces of apparatus does the student need?  a balance, clock, pipette  b balance, clock, thermometer  c balance, pipette, thermometer  d clock, pipette, thermometer      3 chromatography and fractional distillation can be used to separate compounds.   in which type of separation is a thermometer needed for checking that complete separation has  occurred?  a chromatographic separation of two colourless solids  b chromatographic separation of two solids of different colours  c fractional distillation of two colourless liquids  d fractional distillation of two liquids of different colours    ",
            "3": "3  \u00a9 ucles 2008 0620/01/m/j/08 [turn over  4 the nucleon number and proton number of the lithium atom are shown by the symbol li7 3.    what is the correct symbol for the lithium ion in lithium chloride?  a 6 2li\u2212 b 6 3li+ c 73li+ d 73li\u2212      5 the table shows the numbers of particles present in the nuclei of four atoms or ions.     protons neutrons electron structure  1 18 22 2,8,8  2 19 20 2,8,8  3 19 21 2,8,8,1  4 20 20 2,8,8,2    which two particles belong to the same element?  a 1 and 2 b 1 and 4 c 2 and 3 d 2 and 4      6 what are the nucleon numbers for carbon and magnesium?     carbon magnesium  a 6 12  b 6 24  c 12 12  d 12 24    7 which of the following can be used as a lubricant?     graphite a liquid fraction from petroleum  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "4": "4  \u00a9 ucles 2008 0620/01/m/j/08  8 the diagram shows the outer shell electron arrangement of compound j that contains the  elements y and z.    y z yy     what type of compound is j?  a an alloy  b a macromolecule  c covalent  d ionic      9 the electronic structures of atoms p and q are shown.    p q= electronkey     p and q react to form an ionic compound.    what is the formula of this compound?  a pq 2 b p2q c p2q6 d p6q2     10 for which compound is the formula correct?     compound formula  a ammonium chloride nh 3cl  b copper( ii) sulphide cus  c iron( ii) sulphide fe 3s  d silver nitrate ag 2no 3     ",
            "5": "5  \u00a9 ucles 2008 0620/01/m/j/08 [turn over  11 the diagram shows a molecule of vinyl chloride (used to make pvc).    a carbon atom a chlorine atom a hydrogen atomkey     what is the formula of vinyl chloride?  a ch 2cl3 b ch 3cl2 c c 2hc l3 d c 2h3cl     12 which apparatus could be used to electroplate an iron nail with copper?    +ve \u2013vea +ve \u2013veb +ve \u2013vecdaqueous copper( ii) sulphate aqueous iron(ii) sulphate+ve \u2013vekey copper sheet iron nail      ",
            "6": "6  \u00a9 ucles 2008 0620/01/m/j/08  13 two elements x and y form ionic compounds, xbr 2 and y 2o3. the compounds are separately  melted and electricity is passed through the liquids.    what are the products at the cathodes?  a bromine and oxygen  b bromine and y  c oxygen and x  d x and y      14 which change can take place during electrolysis?  a lead( iv) oxide \u2192 lead( ii) oxide + oxygen  b concentrated hydrochloric acid \u2192 hydrogen + chlorine  c sodium hydroxide + nitric acid \u2192 sodium nitrate + water  d lead( ii) nitrate + sulphuric acid \u2192 lead( ii) sulphate + nitric acid    15 the diagram shows an experiment.    dilute hydrochloric acid 20  \u00b0c ph2aqueous zinc chloride22  \u00b0c ph7 before afterzinc oxide powder     which terms describe the experiment?     endothermic neutralisation  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "7": "7  \u00a9 ucles 2008 0620/01/m/j/08 [turn over  16 charcoal and uranium are used as sources of energy.    which of them are oxidised when used in this way?     charcoal uranium  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     17 magnesium reacts with acids to produce hydrogen gas.     under which set of conditions is hydrogen formed the most slowly?     magnesium acid temperature  / \u00b0c  a ribbon concentrated 40  b ribbon dilute 20  c powder concentrated 40  d powder dilute 20    18 when written as formulae, which compound has the greatest number of oxygen atoms?  a calcium oxide  b copper( ii) oxide  c iron( iii) oxide  d potassium oxide     ",
            "8": "8  \u00a9 ucles 2008 0620/01/m/j/08  19 the equation explains the colour change that occurs when aqueous potassium hydroxide is  added to aqueous potassium dichromate( vi).    k2cr2o7  +  2koh  \u2192  2k 2cro 4  +  h 2o  potassium  potassium  dichromate( vi) chromate( vi)  orange  yellow    as a result of adding an excess of aqueous potassium hydroxide to aqeous potassium  dichromate( vi), what happens to the oxidation state of the chromium and the ph of the reaction  mixture?     oxidation state of the  chromium ph of the mixture  a decreases decreases  b decreases increases  c stays the same decreases  d stays the same increases     20 an oxide of element x dissolves in water to form a solution of ph 5.    which line in the table is correct?     type of element type of oxide  a metallic acidic  b metallic basic  c non-metallic acidic  d non-metallic basic    21 which statement describes a test for carbon dioxide gas?  a it bleaches damp litmus paper.  b it relights a glowing splint.  c it turns cobalt( ii) chloride paper pink.  d it turns limewater cloudy.     ",
            "9": "9  \u00a9 ucles 2008 0620/01/m/j/08 [turn over  22 a solution of zinc sulphate can be made by adding an excess either  of zinc carbonate or of zinc  hydroxide to dilute sulphuric acid.    in which forms are these zinc compounds added to the acid?     zinc carbonate zinc hydroxide  a aqueous aqueous  b aqueous solid  c solid aqueous  d solid solid      23 which aqueous ion causes a white precipitate to form when acidified aqueous silver nitrate is  added to it?  a chloride  b iodide c nitrate d sulphate     24 what is the colour of gaseous chlorine and of solid sodium chloride?     chlorine sodium chloride  a colourless yellow-green  b colourless white  c yellow-green yellow-green  d yellow-green white    25 the group i elements lithium and potassium are tested.    which element has the higher melting point and which element reacts more vigorously with water?     higher melting point more vigorous  reaction with water  a lithium lithium  b lithium potassium  c potassium lithium  d potassium potassium     ",
            "10": "10  \u00a9 ucles 2008 0620/01/m/j/08  26 the proton numbers of four elements are shown.    which element forms a singly charged positive ion in its salts?    element proton number  a 34  b 35  c 36  d 37     27 the table gives information about four elements.    which element is a transition metal?     electrical  conductivity density  g  / cm3 melting point  in \u00b0c  a good 0.97 98  b good 7.86 1535  c poor 2.33 1410  d poor 3.12 \u20137    28 which diagram best represents the structure of a solid alloy?    a b c d      29 element e    \u2022 forms an alloy;  \u2022 has a basic oxide;  \u2022 is below hydrogen in the reactivity series.    what is element e?  a carbon  b copper  c sulphur  d zinc     ",
            "11": "11  \u00a9 ucles 2008 0620/01/m/j/08 [turn over  30 the position of metal x in the reactivity series is shown.    k   na   mg   fe   (h)   x    which statements about x and its oxide are correct?     reaction of x with dilute  hydrochloric acid reaction of oxide of x  with carbon  a hydrogen formed no reaction  b hydrogen formed oxide reduced  c no reaction no reaction  d no reaction oxide reduced     31 the diagram shows a blast furnace used to extract iron from iron ore.    iron ore + coke + limestone waste gases hot air molten ironslag     why is limestone added to the furnace?  a to cause the furnace to heat up  b to change the ore into iron  c to convert impurities in the ore into slag  d to produce oxygen for the coke to burn     ",
            "12": "12  \u00a9 ucles 2008 0620/01/m/j/08  32 which uses of the metals shown are both correct?     aluminium stainless steel  a aircraft bodies car bodies  b car bodies aircraft bodies  c chemical plant food containers  d food containers chemical plant     33 in which industrial process is water essential?  a the production of aluminium from bauxite  b the production of calcium oxide from limestone  c the production of ethanol from ethene  d the production of petrol from crude oil    34 some students are asked to suggest why acetylene, rather than ethanol, is the fuel used for  welding metals.    two suggestions are    1 acetylene is a gas but ethanol is a liquid;  2 acetylene burns with a hotter flame.    which suggestions are correct?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "13": "13  \u00a9 ucles 2008 0620/01/m/j/08 [turn over  35 the diagrams show four sacks which a farmer has in his barn.    nitram ammonium nitrate1 lime calcium oxide2 nitre potassium nitrate3 super superphosphate4     which sacks should be mixed to make a complete fertiliser, containing all the essential elements  needed by plants?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     36 which of the following does not produce carbon dioxide?  a adding hydrochloric acid to carbon  b adding hydrochloric acid to potassium carbonate  c burning coke  d burning petrol    ",
            "14": "14  \u00a9 ucles 2008 0620/01/m/j/08  37 cholesterol occurs naturally in the body.    its name indicates that it has the same functional group as    a hh hchhchb hh hchhcohc h hchhcd hh hcc ho o      38 which fuel is a mixture of hydrocarbons?  a coal  b methane c petroleum  d wood     39 in the diagram, which substance could be ethene?    state at room temperature is it saturated? is it saturated?gas liquid a byes no cdyes no      40 which properties do butane, propene and ethanol all have?     burn polymerise  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "15": "15   0620/01/m/j/08  blank page",
            "16": "16    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/01/m/j/08  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s08_qp_2.pdf": {
            "1": "    this document consists of 16 printed pages.  ib08 06_0620_02/4rp  \u00a9 ucles 2008  [turn over      *6335113340* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/02     paper 2  may/june 2008     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name in the spaces at the top of this page.  write in dark blue or black pen. you may need to use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes   answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2008 0620/02/m/j/08  for  examiner's  use 1 the diagram shows the structures of some substances containing carbon.    oc o cch hhhch hh h cco hhhhhh cc cccc ccccccc ccc cc cccc cc c ccc cc ccccc cccca2+co2\u2013 3 ca2+co2\u2013 3 co2\u2013 3ca2+ca2+co2\u2013 3 co2\u2013 3ca2+ca2+co2\u2013 3 ca2+co2\u2013 3 co2\u2013 3ca2+ca2+co2\u2013 3 co2\u2013 3ca2+ ab c de f       (a) answer these questions using the letters a, b, c, d, e  or f.    (i) which one of these structures is ionic?  [1]   (ii) which one of these structures represents ethanol?  [1]    (iii) which one of these structures represents a gas which  turns limewater milky?  [1]    (iv) which one of these structures is an unsaturated  hydrocarbon?  [1]     (b) describe a chemical test for an unsaturated hydrocarbon.  test   result  [2]    ",
            "3": "3  \u00a9 ucles 2008 0620/02/m/j/08 [turn over  for  examiner's  use  (c) state the chemical name of structure b.   [1]      (d) structure f has several uses. which one of the following is a correct use of structure f?   tick one box.       for cutting metals       as a lubricant       for filling balloons       as an insulator   [1]     (e) the structures a to e are compounds. what do you understand by the term compound ?     [1]     (f) state the type of bonding in structure a.   [1]     [total: 10]   ",
            "4": "4  \u00a9 ucles 2008 0620/02/m/j/08  for  examiner's  use 2 the diagram shows a statue in a park in an industrial town. the statue is made from  limestone.     iron pins inside statue statue when first erectedthe same statue after 20 years       (a) state the name of the chemical present in limestone.   [1]    (b) use ideas about the chemistry of atmospheric pollutants to suggest how and why the statue changes over 20 years.           [4]      (c) parts of the statue are joined together with iron pins. after 30 years, the arm falls off the statue.   suggest why the arm falls off.   [1]   ",
            "5": "5  \u00a9 ucles 2008 0620/02/m/j/08 [turn over  for  examiner's  use  (d) iron has several isotopes.     (i) what do you understand by the term isotopes ?   [1]   (ii) the table shows the number of subatomic particles in an atom of iron.      type of particle number of particles relative charge on the particle  electron 26   neutron 30   proton 26        complete the table to show the relative charge on each particle. [3]    (iii) state the number of nucleons in this isotope of iron.   [1]     (e) some isotopes are radioactive. state one industrial use of radioactive isotopes.   [1]     (f) iron reacts with very dilute nitric acid.    fe  +  2hno 3    fe(no 3)2  +  h 2    write a word equation for this reaction.             [1]     [total: 13] ",
            "6": "6  \u00a9 ucles 2008 0620/02/m/j/08  for  examiner's  use 3 the table shows the concentration of some ions present in seawater.    name of ion formula of ion concentration of  ion in g  / dm3  bromide br  \u2013 0.07  calcium ca2+ 0.4  chloride cl \u2013 19.1  magnesium mg2+ 1.2  potassium k+ 0.3  sodium na+ 10.6   \u22122 4so  0.8     (a) which negative ion has the highest concentration in seawater?   [1]      (b) state the name of the ion with the formula  \u22122 4so .   [1]       (c) which two ions in the table are formed from group i elements?   and  [1]       (d) when seawater is evaporated a number of different compounds are formed.   state the name of the compound which is present in the greatest quantity.   [1]       (e) state the names of two ions in the table which move to the cathode when seawater is  electrolysed.   and  [2]   ",
            "7": "7  \u00a9 ucles 2008 0620/02/m/j/08 [turn over  for  examiner's  use  (f) when concentrated seawater is electrolysed, chlorine is formed at one of the electrodes.     (i) to which period in the periodic table does chlorine belong?   [1]     (ii) draw the electronic structure of a chlorine molecule. show only the outer electrons.                   [2]     (g) drinking water can be obtained by purifying seawater.   explain why distillation rather than filtration is used to purify seawater for drinking.     [2]     [total: 11]    ",
            "8": "8  \u00a9 ucles 2008 0620/02/m/j/08  for  examiner's  use 4 the diagram shows a water treatment works.    water in to homeschlorine addedaluminium sulphate added sedimentation tank sand filter      (a) state one use of water in industry.   [1]     (b) explain how the sand filter helps purify the water.     [2]     (c) the aluminium ions in aluminium sulphate cause clay particles to clump together.   describe a test for aluminium ions.  test   result    [3]     (d) why is chlorine added to the water?   [1]    ",
            "9": "9  \u00a9 ucles 2008 0620/02/m/j/08 [turn over  for  examiner's  use  (e) chlorine is in group vii of the periodic table.   when chlorine reacts with a solution of potassium bromide, the solution turns a  reddish \u2013 brown colour.     (i) write a word equation for this reaction.           [2]     (ii) explain why iodine does not react with a solution of potassium bromide.   [1]    (f) when chlorine reacts with sodium to form sodium chloride, energy is released.    (i) state the name given to a reaction which releases energy.   [1]    (ii) what type of bonding is present in sodium chloride?   [1]    (iii) explain what happens in terms of electron transfer when a sodium atom reacts with a chlorine atom.     [2]     [total: 14]   ",
            "10": "10  \u00a9 ucles 2008 0620/02/m/j/08  for  examiner's  use 5 pure dry crystals of magnesium sulphate can be made by reacting excess magnesium  powder with dilute sulphuric acid.    (a) during the reaction, bubbles of a colourless gas are given off.   state the name of this gas.   [1]       (b) (i)  why is excess magnesium used?   [1]   (ii) how is the excess magnesium removed from the reaction mixture?   [1]    (c) describe how you can obtain pure dry crystals of magnesium sulphate from a solution  of magnesium sulphate.     [2]       (d) (i)  describe one other reaction that makes magnesium sulphate.     [1]     (ii) write a word equation for the reaction you suggested in part (d)(i) .           [1]    (iii) magnesium sulphate can be used as a medicine. explain why the chemicals used  in medicines need to be as pure as possible.     [1]    ",
            "11": "11  \u00a9 ucles 2008 0620/02/m/j/08 [turn over  for  examiner's  use  (e) a student repeats the experiment using excess sulphuric acid.   she obtains 24  g of magnesium sulphate from 4.8  g of magnesium.   how much magnesium sulphate can the student obtain from 1.2  g of magnesium?               [1]      (f) a sample of 20  g of impure magnesium sulphate contains 19.5  g of magnesium    sulphate.   calculate the percentage purity of the magnesium sulphate.              [1]    [total: 10]    ",
            "12": "12  \u00a9 ucles 2008 0620/02/m/j/08  for  examiner's  use 6 petroleum is separated into useful fractions by distillation.    petroleumfuel gasfractions petrol paraffin diesel lubricating fraction bitumen       (a) (i)  what do you understand by the term fraction ?     [1]     (ii) which fraction has the lowest boiling point?   [1]    (iii) describe how distillation is used to separate these fractions.       [2]    (iv) state a use for  the paraffin fraction,   the bitumen fraction.  [2]    ",
            "13": "13  \u00a9 ucles 2008 0620/02/m/j/08 [turn over  for  examiner's  use  (b) ethene can be made by cracking certain hydrocarbon fractions.     (i) explain what is meant by the term cracking .     [1]     (ii) complete the equation for the cracking of tetradecane, c 14h30.  c14h30       +  c 2h4 [1]     (c) ethanol is formed when steam reacts with ethene at high pressure and temperature. a  catalyst of phosphoric acid is used.    ethene  + steam     ethanol    (i) what is the function of the catalyst?   [1]     (ii) what is the meaning of the symbol ?   [1]   (iii) ethanol is also formed when yeast grows in sugar solution.   what is this process called?  put a ring around the correct answer.      addition   combustion   fermentation   neutralisation   [1]    (iv) phosphoric acid is a typical acid. state what you would observe when a solution of phosphoric acid is added to  blue litmus,   a solution of sodium carbonate.  [2]    [total: 13]   ",
            "14": "14  \u00a9 ucles 2008 0620/02/m/j/08  for  examiner's  use 7 a student placed a crystal of copper( ii) sulphate in a beaker of water.   after one hour the crystal had completely disappeared and a dense blue colour was  observed in the water at the bottom of the beaker. after 48 hours the blue colour had spread  throughout the water.     water copper( ii) sulphate crystalafter 1 hour after 48 hours       (a) use the kinetic particle theory to explain these observations.         [2]       (b) describe the arrangement and motion of the particles in the copper( ii) sulphate crystal.  arrangement   motion  [2]     (c) copper ions can be separated from other metal ions by paper chromatography. draw a labelled diagram of the apparatus for paper chromatography.    in your diagram include   \u007f the solvent,  \u007f the spot where the solution containing copper ions is placed.                        [2]   ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/02/m/j/08 for  examiner's  use  (d) copper can be purified by electrolysis.    impure copper foil pure copper foil copper(ii) sulphate solution+ \u2013      (i) choose a word from the list below which describes the pure copper foil.   put a ring around the correct answer.   anion  anode   cathode   cation   electrolyte   [1]    (ii) describe what happens during this electrolysis to  the pure copper foil,   the impure copper foil.  [2]     [total: 9]    ",
            "16": "16  \u00a9 ucles 2008 0620/02/m/j/08  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s08_qp_3.pdf": {
            "1": "location entry codes       as part of cie\u2019s continual commitment to main taining best practice in assessment, cie uses  different variants of some question papers for our most popular assessments with large and  widespread candidature. the question papers are closely related and the relationships between  them have been thoroughly established using our assessment expertise.  all versions of the  paper give assessment of equal standard.     the content assessed by the examination papers and the type of questions is unchanged.   this change means that for this component there are now two variant question papers, mark  schemes and principal examiner\u2019s reports where previously there was only one.  for any individual country, it is intended that only one variant is used.  this document contains both  variants which will give all centres access to even more past examination ma terial than is usually  the case.      the diagram shows the relationship between the question papers, mark schemes and principal examiners\u2019 reports that are available.     question paper   mark scheme  principal examiner\u2019s  report  introduction     introduction   introduction   first variant question paper    first variant mark scheme  first variant principal  examiner\u2019s report    second variant question  paper  second variant mark  scheme    second variant principal  examiner\u2019s report      who can i contact for further information on these changes?  please direct any questions about this to cie\u2019s customer services team at: international@cie.org.uk              the titles for the variant items should correspond with the table above, so that at the top of the  first page of the relevant part of the document and on the header, it has the words:    \u2022 first variant question paper / mark scheme / principal examiner\u2019s report     or     \u2022 second variant question paper / mark scheme / principal examiner\u2019s report      as appropriate.    ",
            "2": "    this document consists of 11 printed pages and 1 blank page.  ibo8.06_0620_31/4rp  \u00a9 ucles 2008  [turn over      *7190250824* for examiner's use  1   2   3   4   5   6   7   8   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/31     paper 3 (extended)  may/june 2008     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes   answer all questions. a copy of the periodic table is printed on page 12.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  questions.   ",
            "3": "2  \u00a9 ucles 2008 0620/31/m/j/08  for  examiner's  use 1 for each of the following select an element from period 4, potassium to krypton, that  matches the description.    (a) it is a brown liquid at room temperature.      (b) it forms a compound with hydrogen having the formula xh 4.      (c) a metal that reacts violently with cold water.      (d) it has a complete outer energy level.      (e) it has oxidation states of 2 and 3 only.      (f) it can form an ion of the type x-.      (g) one of its oxides is the catalyst in the contact process.       [total: 7]   ",
            "4": "3  \u00a9 ucles 2008 0620/31/m/j/08 [turn over  for  examiner's  use 2 (a)  complete the table which gives the names, symbols, relative masses and relative  charges of the three subatomic particles.    name symbol relative mass relative charge  electron e-    proton  1    n  0   [3]     (b) use the information in the table to explain the following.     (i) atoms contain charged particles but they are electrically neutral because they  have no overall charge.     [2]    (ii) atoms can form positive ions.     [2]     (iii) atoms of the same element can have different masses.     [2]     (iv) scientists are certain that there are no undiscovered elements missing from the  periodic table from hydrogen to lawrencium.   [1]    [total: 10]    ",
            "5": "4  \u00a9 ucles 2008 0620/31/m/j/08  for  examiner's  use 3 copper is purified by electrolysis.     (a) complete the following.  the positive electrode (anode) is made from   the negative electrode (cathode) is made from   the electrolyte is aqueous  [3]       (b) write an ionic equation for the reaction at the positive electrode (anode).   [2]     (c) (i)  give two reasons why copper is used,  in electric wiring,     [2]    in cooking utensils.     [2]      (ii) give another use of copper.   [1]    [total: 10]     ",
            "6": "5  \u00a9 ucles 2008 0620/31/m/j/08 [turn over  for  examiner's  use 4 sulphuric acid is a typical strong acid.     (a) change the equations given into a different format.    (i) mg   +  h 2so 4    mgso 4  +  h 2   change into a word equation.   [1]    (ii) lithium oxide +  sulphuric acid     lithium sulphate + water   change into a symbol equation.   [2]    (iii) cuo  +  2h +    cu2+  +  h 2o   change the ionic equation into a symbol equation.   [2]     (iv) na 2co 3  +  h 2so 4    na 2so 4  +  co 2  +  h 2o   change into a word equation.   [1]      (b) when sulphuric acid dissolves in water, the following reaction occurs.   h 2so 4  +  h 2o    hso 4-  +  h 3o+   explain why water is behaving as a base in this reaction.   [2]       (c) sulphuric acid is a strong acid, ethanoic acid is a weak acid.   explain the difference between a strong acid and a weak acid.     [2]     [total: 10]    ",
            "7": "6  \u00a9 ucles 2008 0620/31/m/j/08  for  examiner's  use 5 carbonyl chloride, coc l2, is a colourless gas. it is made by the following reaction.     cool    co(g)  +  c l2(g)     cocl 2(g)   heat     (a) when the pressure on the equilibrium mixture is decreased, the position of equilibrium  moves to left.    (i) how does the concentration of each of the three chemicals change?     [2]     (ii) explain why the position of equilibrium moves to left.     [2]     (b) using the information given with the equation, is the forward reaction exothermic or endothermic? give a reason for your choice.     [2]     (c) carbonyl chloride reacts with water to form two acidic compounds.   suggest which acidic compounds are formed.  1.   2.  [2]     (d) the structural formula of carbonyl chloride is given below.    oc clcl      draw a diagram that shows the arrangement of the valency electrons in one molecule  of this covalent compound.   use x for an electron from a chlorine atom.   use o for an electron from a carbon atom.   use \u25cf for an electron from an oxygen atom.         [4]   [total: 12] ",
            "8": "7  \u00a9 ucles 2008 0620/31/m/j/08 [turn over  for  examiner's  use 6 three of the factors that can influence the rate of a chemical reaction are:    \u007f physical state of the reactants  \u007f light  \u007f the presence of a catalyst     (a) the first recorded dust explosion was in a flour mill in italy in 1785. flour contains  carbohydrates. explosions are very fast exothermic reactions.     (i) use the collision theory to explain why the reaction between the particles of flour and the oxygen in the air is very fast.     [2]     (ii) write a word equation for this exothermic reaction.   [1]     the decomposition of silver( i) bromide is the basis of film photography. the equation for  this decomposition is:     2agbr    2ag  +  br 2   white  black    this reaction is photochemical.  a piece of white paper was coated with silver( i) bromide and the following experiment was  carried out.  paper coated with silver(i) bromidenot covered covered with thin paper covered with thick cardblack greywhiteinitiallysome time later with the card and paper removed exposure to light      (b) explain the results.         [3]   ",
            "9": "8  \u00a9 ucles 2008 0620/31/m/j/08  for  examiner's  use  (c) the fermentation of glucose is catalysed by enzymes from yeast. yeast is added to  aqueous glucose, the solution starts to bubble and becomes cloudy as more yeast cells are formed.    c 6h12o6(aq)    2c 2h5oh(aq)  +  2co 2(g)    the reaction is exothermic.   eventually the fermentation stops when the concentration of ethanol is about 12%.      (i) what is an enzyme?   [1]   (ii) pasteur said that fermentation was respiration in the absence of air. suggest a definition of respiration .     [2]     (iii) on a large scale, the reaction mixture is cooled. suggest a reason why this is  necessary.   [1]    (iv) why does the fermentation stop? suggest two reasons.     [2]       (v) when the fermentation stops, there is a mi xture of dilute aqueous ethanol and  yeast. suggest a technique which could be used to remove the cloudiness due to the yeast.   [1]      name a technique which will separate the ethanol from the ethanol  / water mixture.   [1]    [total: 14]   ",
            "10": "9  \u00a9 ucles 2008 0620/31/m/j/08 [turn over  for  examiner's  use 7 crystals of sodium sulphate-10-water, na 2so 4.10h 2o, are prepared by titration.    conical flaskburette filled with sulphuric acid 25.0  cm3 of sodium hydroxide(aq) concentration 2.24  mol  / dm3     (a) 25.0  cm3 of aqueous sodium hydroxide is pipetted into a conical flask.   a few drops of an indicator are added. using a burette, dilute sulphuric acid is slowly  added until the indicator just changes colour. the volume of acid needed to neutralise  the alkali is noted.     suggest how you would continue the experiment to obtain pure, dry crystals of sodium  sulphate-10-water.         [4]     (b) using 25.0  cm3 of aqueous sodium hydroxide, 2.24  mol  / dm3, 3.86  g of crystals were  obtained. calculate the percentage yield.    2naoh  +  h 2so 4    na 2so 4  +  2h 2o    na 2so 4  +  10h 2o    na 2so 4.10h 2o    number of moles of naoh used =  maximum number of moles of  na 2so 4.10h 2o that could be formed =   mass of one mole of na 2so 4.10h 2o = 322  g   maximum yield of sodium sulphate-10-water =  g  percentage yield =  % [4]     [total: 8]   ",
            "11": "10  \u00a9 ucles 2008 0620/31/m/j/08  for  examiner's  use 8 large areas of the amazon rain forest are cl eared each year to grow soya beans. the trees  are cut down and burnt.     (a) why do these activities increase the percentage of carbon dioxide in the atmosphere?     [2]      (b) soya beans contain all three main food groups. two of which are protein and  carbohydrate.     (i) what is the third group?   [1]    (ii) draw the structural formula of a complex carbohydrate such as starch.                  [3]     (iii) compare the structure of a protein with that of a synthetic polyamide. the structure of a typical protein is given below.    n c o hhnc ohnc oo hn c      how are they similar?        how are they different?     [3]     [total: 9]       ",
            "12": "11    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/31/m/j/08 blank page",
            "13": "12  \u00a9 ucles 2008 0620/31/m/j/08 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  ",
            "14": "    this document consists of 11 printed pages and 1 blank page.  ib08 06_0620_32_tz/rp  \u00a9 ucles 2008  [turn over      *8672182532* for examiner's use  1   2   3   4   5   6   7   8   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/32     paper 3 (extended)  may/june 2008     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes   answer all questions. a copy of the periodic table is printed on page 12.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  questions.   ",
            "15": "2  \u00a9 ucles 2008 0620/32/m/j/08  for  examiner's  use 1 for each of the following select an element from period 4, potassium to krypton, that  matches the description.    (a) it is a brown liquid at room temperature.     (b)   it forms a covalent compound with hydrogen having the formula h 2x.      (c) a metal that reacts violently with cold water.      (d) it has a complete outer energy level.      (e) it has oxidation states of 2 and 3 only.      (f) it can form an ion of the type x  +.     (g) this metal is the catalyst in the haber process.       [total: 7]   ",
            "16": "3  \u00a9 ucles 2008 0620/32/m/j/08 [turn over  for  examiner's  use 2 (a)  complete the table which gives the names, symbols, relative masses and relative  charges of the three subatomic particles.     name symbol relative mass relative charge  electron e-    proton  1   neutron n     [3]     (b) use the information in the table to explain the following.     (i) atoms contain charged particles but they are electrically neutral - they have no overall charge.     [2]    (ii) atoms can form negative ions.     [2]     (iii) different  atoms of the element chlorine are 35 17cl and  3717cl.  how are they different?   how are they the same?  [2]     (iv) scientists are certain that there are no undiscovered elements missing from the  periodic table from hydrogen to lawrencium.   [1]   [total: 10]     ",
            "17": "4  \u00a9 ucles 2008 0620/32/m/j/08  for  examiner's  use 3 copper is purified by electrolysis.     (a) complete the following.  the positive electrode (anode) is made from   the negative electrode (cathode) is made from   the electrolyte is aqueous  [3]       (b) write an ionic equation for the reaction at the positive electrode (anode).   [2]     (c) (i)  give two reasons why copper is used,  in electric wiring,     [2]    in cooking utensils.     [2]      (ii) give another use of copper.   [1]    [total: 10]     ",
            "18": "5  \u00a9 ucles 2008 0620/32/m/j/08 [turn over  for  examiner's  use 4 sulphuric acid is a typical strong acid.     (a) change the equation given into a different format.     (i) mg   +  h 2so 4    mgso 4  +  h 2   change into a word equation.   [1]    (ii) lithium oxide +  sulphuric acid     lithium sulphate + water   change into a symbol equation.   [2]     (iii) cuco 3  +  2h+    cu2+  +  h 2o  +  co 2   change the ionic equation into a symbol equation.   [2]     (iv) na 2co 3  +  h 2so 4    na 2so 4  +  co 2  +  h 2o   change into a word equation.   [1]      (b) when sulphuric acid dissolves in water, the following reaction occurs.   h 2so 4  +  h 2o    hso 4-  +  h 3o+   explain why water is behaving as a base.   [2]      (c) sulphuric acid is a strong acid, ethanoic acid is a weak acid. one way of distinguishing  between them is to measure their ph. the weaker acid will have the higher ph. describe another way by which they could be distinguished.     [2]     [total: 10]   ",
            "19": "6  \u00a9 ucles 2008 0620/32/m/j/08  for  examiner's  use 5 carbonyl chloride, coc l2, is a colourless gas. it is made by the following reaction.     cool    co(g)  +  c l2(g)     cocl 2(g)   heat    (a) when the pressure on the equilibrium mixture is increased, the position of equilibrium moves to right.     (i) how does the concentration of each of the three chemicals change?     [2]     (ii) explain why the position of equilibrium moves to right.     [2]     (b) using the information given with the equation, is the forward reaction exothermic or  endothermic? give a reason for your choice.     [2]     (c) carbonyl chloride reacts with water to form two acidic compounds.   name them.   [2]     (d) the structural formula of carbonyl chloride is given below.    oc clcl      draw a diagram that shows the arrangement of the valency electrons in one molecule  of this covalent compound.   use x for an electron from a chlorine atom.  use o for an electron from a carbon atom.  use \u25cf for an electron from an oxygen atom.         [4]   [total: 12]   ",
            "20": "7  \u00a9 ucles 2008 0620/32/m/j/08 [turn over  for  examiner's  use 6 three of the factors that can influence the rate of a chemical reaction are:    \u007f physical state of the reactants  \u007f light  \u007f the presence of a catalyst     (a) the first recorded dust explosion was in a flour mill in italy in 1785. flour contains  carbohydrates. explosions are very fast exothermic reactions.     (i) use the collision theory to explain why the reaction between the particles of flour and the oxygen in the air is very fast.     [2]     (ii) write a word equation for this exothermic reaction.   [1]     the decomposition of silver( i) bromide is the basis of film photography. the equation for  this decomposition is:     2agbr    2ag  +  br 2   white  black    (b) this reaction is photochemical.   a piece of white paper was coated with silver( i) bromide and the following experiment  was carried out.  paper coated with silver(i) bromidenot covered covered with thin paper covered with thick cardblack greywhiteinitiallysome time later with the card and paper removed exposure to light      explain the results.       [3]     ",
            "21": "8  \u00a9 ucles 2008 0620/32/m/j/08  for  examiner's  use  (c) the fermentation of glucose is catalysed by enzymes from yeast. yeast is added to  aqueous glucose, the solution starts to bubble and becomes cloudy as more yeast cells are formed.    c 6h12o6(aq)    2c 2h5oh(aq)  +  2co 2(g)    the reaction is exothermic.   eventually the fermentation stops when the concentration of ethanol is about 12%.      (i) what is an enzyme?   [1]   (ii) pasteur said that fermentation was respiration in the absence of air. define respiration .     [2]     (iii) on a large scale, the reaction mixture is cooled. suggest a reason why this is  necessary.   [1]    (iv) why does the fermentation stop? suggest two reasons.     [2]       (v) when the fermentation stops, there is a mi xture of dilute aqueous ethanol and  yeast. suggest a technique which could be used to remove the cloudiness due to the yeast.   [1]      name another technique which will separate the ethanol from the ethanol  / water  mixture.   [1]    [total: 14]     ",
            "22": "9  \u00a9 ucles 2008 0620/32/m/j/08 [turn over  for  examiner's  use 7 crystals of sodium sulphate-10-water, na 2so 4.10h 2o, are prepared by titration.    conical flaskburette filled with sulphuric acid 25.0  cm3 of sodium hydroxide(aq) concentration 2.64  mol  / dm3     (a) 25.0  cm3 of aqueous sodium hydroxide is pipetted into a conical flask.   a few drops of an indicator are added. using a burette, dilute sulphuric acid is slowly  added until the indicator just changes colour. the volume of acid needed to neutralise  the alkali is noted.     suggest how you would continue the experiment to obtain pure, dry crystals of sodium  sulphate-10-water.         [4]     (b) using 25.0  cm3 of aqueous sodium hydroxide, 2.64  mol  / dm3, 3.95  g of crystals were  obtained. calculate the percentage yield.    2naoh  +  h 2so 4    na 2so 4  +  2h 2o    na 2so 4  +  10h 2o    na 2so 4.10h 2o    number of moles of naoh used =  maximum number of moles of  na 2so 4.10h 2o that could be formed =   mass of one mole of na 2so 4.10h 2o = 322  g   maximum yield of sodium sulphate-10-water =  g  percentage yield =  % [4]     [total: 8]   ",
            "23": "10  \u00a9 ucles 2008 0620/32/m/j/08  for  examiner's  use 8 large areas of the amazon rain forest are cleared each year to grow soya beans. the trees  are cut down and burnt.    (a) why do these activities increase the percentage of carbon dioxide in the atmosphere?     [2]      (b) soya beans contain all three main food groups.  two of which are protein and  carbohydrate.    (i) what is the third group?   [1]    (ii) draw the structural formula of a complex carbohydrate such as starch.                 [3]    (iii) compare the structure of a protein with that of a synthetic polyamide. the structure of a typical protein is given below.    n c o hhnc ohnc oo hn c      how are they similar?        how are they different?     [3]     [total: 9]     ",
            "24": "11    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/32/m/j/08  blank page",
            "25": "12  \u00a9 ucles 2008 0620/32/m/j/08   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements    "
        },
        "0620_s08_qp_5.pdf": {
            "1": "    this document consists of 6 printed pages and 2 blank pages.  ib08 06_0620_05/3rp  \u00a9 ucles 2008  [turn over      *6928316447* for examiner's use  1   2   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/05     paper 5 practical test  may/june 2008     1 hour 15 minutes    candidates answer on the question paper .    additional materials: as listed in confidential instructions       read these instructions first    write your, centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions.  practical notes are provided on page 8.   at the end of the examination, fasten all you work securely together.  the number of marks is given in brackets [  ] at the end of each question or part question.   ",
            "2": "2  \u00a9 ucles 2008 0620/05/m/j/08  for  examiner's  use 1 you are going to investigate the reaction between potassium manganate( vii) and a metallic  salt solution.     read all the instructions below carefully before starting the two experiments .     experiment 1     (a) pour a little of the metal salt solution a into a test-tube. add about 1  cm3 of aqueous  sodium hydroxide and note your observation.  observation  [1]     (b) fill the burette provided up to the 0.0  cm3 mark with the potassium manganate( vii)  solution. using a measuring cylinder, pour 25  cm3 of solution a of the salt solution into     the conical flask provided. shake the flask to mix the contents.     from the burette add 1  cm3 of the potassium manganate( vii) solution to the flask, and  shake to mix thoroughly. continue to add potassium manganate( vii) solution to the  flask until there is a pale pink colour in the contents of the flask. record the burette readings in the table.    experiment 2    (c) pour away the contents of the flask and rinse with distilled water. fill the burette up to  the 0.0  cm3 mark with the potassium manganate( vii) solution. repeat experiment 1(b)  exactly using solution b instead of solution a. record your burette readings in the table  and complete the table.     (d) pour a little of the solution in the flask into a test-tube. add about 1  cm3 of aqueous  sodium hydroxide and note your observation.  observation  [1]     table of results   burette readings  / cm3     experiment 1 experiment 2  final reading    initial reading    difference       [6]",
            "3": "3  \u00a9 ucles 2008 0620/05/m/j/08 [turn over  for  examiner's  use  (e) describe the appearance of the solution in the conical flask before adding the  potassium manganate( vii) solution.   [1]      (f) what happens to the colour of the solution in the flask as the     potassium manganate( vii) solution is added?   [1]     (g) (i)  in which experiment was the greatest volume of potassium manganate( vii)  solution used?   [1]   (ii) compare the volumes of potassium manganate( vii) solution used in  experiments 1 and 2.     [1]    (iii) suggest an explanation for the difference in the volumes.     [2]     (h) predict the volume of potassium manganate solution which would be needed to react completely with 50  cm3 of solution b.     [2]    (i) explain one change that could be made to the experimental method to obtain more accurate results.  change   explanation  [2]      (j) what conclusion can you draw about the salt solution from    (i)experiment 1(a),  [1]  (ii) experiment 2(d)?  [1]  [total: 20] ",
            "4": "4  \u00a9 ucles 2008 0620/05/m/j/08  for  examiner's  use 2 you are provided with two solids, solid t and solid v.   carry out the following tests on t and  v, recording all of your observations in the table.   conclusions must not be written in the table.    tests observations      [1] tests on solid t    (a) describe the appearance of  solid t.      [2]      (b) place a little of solid t in a   test-tube. heat the solid gently,  then more strongly. test the gas given off with a lighted  splint.                   colour    ph  [2]         [2]      [1]   [1]      (c) dissolve one spatula measure of solid t in about 3  cm3 of  distilled water and shake to dissolve.   leave to stand for 1 minute.  decant the liquid into another test-tube.    divide the solution into 3 equal  portions in test-tubes.     (i) test the ph of the solution using universal indicator solution.      (ii) to the second portion add aqueous sodium hydroxide  in drops, then add excess  sodium hydroxide solution.     (iii) to the third portion of  solution add about 1  cm3 of  iron( iii) chloride solution.  note the colour.     heat the solution.  ",
            "5": "5  \u00a9 ucles 2008 0620/05/m/j/08 for  examiner's  use tests observations   [1] tests on solid v      (d) describe the appearance of  solid v.       [1]   (e) place a little of solid v in a   test-tube. heat the solid gently, then more strongly.         [1]       colour    ph   [2]               [2]          [1]   (f) dissolve one spatula measure of solid v in about 3  cm3 of  distilled water in a test-tube and shake to dissolve. divide  the solution into 3 equal  portions in test-tubes. note the smell of the solution.        (i) repeat (c)(i) using the first portion of the solution.          (ii) repeat (c)(ii) using the  second portion of the solution.         (iii) repeat (c)(iii) using the  third portion of the solution. do not heat the solution.     (g) what conclusion can you draw about solid t?   [1]    (h) what conclusions can you draw about solid v?     [2]     [total: 20]   ",
            "6": "6   0620/05/m/j/08  blank page",
            "7": "7    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/05/m/j/08 blank page",
            "8": "8  \u00a9 ucles 2008 0620/05/m/j/08  notes for use in qualitative analysis     test for anions     anion test test result  carbonate (co 32\u2013) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then aqueous lead( ii) nitrate yellow ppt.  nitrate (no 3\u2013)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulphate (so 42\u2013)  [in solution] acidify with dilute nitric acid, then aqueous barium nitrate white ppt.    test for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh 4+) ammonia produced on warming -  calcium (ca2+) white., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution    test for gases     gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_s08_qp_6.pdf": {
            "1": "    this document consists of 12 printed pages.  ib08 06_0620_06/5rp  \u00a9 ucles 2008  [turn over      *1427920488* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/06     paper 6 alternative to practical  may/june 2008     1 hour    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your, centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes   answer all questions.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2008 0620/06/m/j/08  for  examiner's  use 1 a solution of copper sulphate was made by reacting excess copper oxide with dilute  sulphuric acid. the diagram shows the method used.     warm50  cm3 of dilute sulphuric acid was measured intoa beakercopper oxide wasadded until all thesulphuric acid hadreacted the mixturewas filtered dilute sulphuric acid      (a) complete the empty boxes to name the pieces of apparatus. [3]      (b) what does the term excess mean?   [1]     (c) draw a labelled diagram to show how the mixture was filtered.                                [2]    [total: 6]   ",
            "3": "3  \u00a9 ucles 2008 0620/06/m/j/08 [turn over  for  examiner's  use 2 the diagram shows an experiment to pass electricity through lead bromide.   electricity has no effect on solid lead bromide.     lead bromide toxicd.c. power supply bulb heat     (a) (i)  clearly label the electrodes on the diagram. [1]    (ii) suggest a suitable material to make the electrodes.   [1]    (b) give two observations expected when the lead bromide is heated to melting point.  1.   2.  [2]      (c) state two different safety precautions when carrying out this experiment.  1.   2.  [2]    [total: 6]     ",
            "4": "4  \u00a9 ucles 2008 0620/06/m/j/08  for  examiner's  use 3 sulphur dioxide gas is denser than air and soluble in water. a sample of sulphur dioxide can  be prepared by adding dilute hydrochloric acid to sodium sulphite and warming the mixture. study the diagram of the apparatus used.     water        (a) fill in the boxes to show the chemicals used. [2]      (b) show by using an arrow, on the diagram, where heat is applied. [1]      (c) identify and explain two mistakes in the diagram.  mistake 1     mistake 2    [2]    [total: 5]     ",
            "5": "5  \u00a9 ucles 2008 0620/06/m/j/08 [turn over  for  examiner's  use 4 a student investigated the reaction between potassium manganate( vii) and a metallic salt  solution.     two experiments were carried out.   experiment 1      (a) about 1  cm3 of aqueous sodium hydroxide was added to a little of the salt solution a  and the observation noted.     observation  green precipitate formed        (b) a burette was filled with potassium manganate( vii) solution up to the 0.0  cm3 mark.    by using a measuring cylinder, 25  cm3 of solution a of the salt was placed into a conical  flask. the flask was shaken to mix the contents.   the potassium manganate( vii) solution was added to the flask, and shaken to mix  thoroughly. addition of potassium manganate( vii) solution was continued until there  was a pale pink colour in the contents of the flask.     use the burette diagram to record the volume in the table and complete the column.    25 26 27 final reading     experiment 2   (c) experiment 1(b) was repeated using a different solution b of the salt, instead of solution  a. use the burette diagrams to record the volumes in the table and complete the table.    15 16 17 initial reading28 29 30 final reading   ",
            "6": "6  \u00a9 ucles 2008 0620/06/m/j/08  for  examiner's  use  (d) about 1  cm3 of aqueous sodium hydroxide was added to a little of the solution in the  flask and the observation noted.     observation  red-brown precipitate      table of results    burette readings  / cm3     experiment 1 experiment 2  final reading    initial reading    difference       [4]     (e) (i)  in which experiment was the greatest volume of potassium manganate( vii)  solution used?   [1]     (ii) compare the volumes of potassium manganate( vii) solution used in experiments   1 and 2.     [2]     (iii) suggest an explanation for the difference in the volumes.     [2]      (f) predict the volume of potassium manganate( vii) solution which would be needed to  react completely with 50  cm3 of solution b.     [2]     ",
            "7": "7  \u00a9 ucles 2008 0620/06/m/j/08 [turn over  for  examiner's  use  (g) explain one change that could be made to the experimental method to obtain more  accurate results.  change   explanation  [2]       (h) what conclusion can you draw about the salt solution from    (i) experiment 1(a),   [1]   (ii) experiment 2(d)?   [1]   [total: 15]    ",
            "8": "8  \u00a9 ucles 2008 0620/06/m/j/08  for  examiner's  use 5 two different solids, t and v, were analysed. t was a calcium salt.   the tests on the solids and some of the observations are in the following table.   complete the observations in the table.      tests observations     white solid  tests on solid t      (a) appearance of solid t.     colour orange   ph 5          [2]         [2]     (b) a little of solid t was dissolved  in distilled water. the solution  was divided into three test- tubes.      (i) the ph of the first portion of  the solution was tested.      (ii) to the second portion of  solution was added excess aqueous sodium hydroxide.        (iii) to the third portion of solution was added excess ammonia solution.  ",
            "9": "9  \u00a9 ucles 2008 0620/06/m/j/08 [turn over  for  examiner's  use tests observations  green crystals  tests on solid v      (c) appearance of solid v.  smells of vinegar  colour orange  ph 6    pale blue precipitate    pale blue precipitate soluble in  excess to form a dark blue  solution.  (d) a little of solid v was dissolved  in distilled water. the solution was divided into three test-tubes. the smell of the solution was noted.     (i) test (b)(i)  was repeated  using the first portion of  solution.         (ii) test (b)(ii)  was repeated  using the second portion of  the solution.        (iii) test (b)(iii)  was repeated  using the third portion of solution.          (e) what do tests (b)(i)  and (d)(i)  tell you about solutions t and v?   [2]    (f) what additional conclusions can you draw about solid v?     [2]    [total: 8]     ",
            "10": "10  \u00a9 ucles 2008 0620/06/m/j/08  for  examiner's  use 6 the speed of reaction between excess magnesium and dilute hydrochloric acid was  investigated using the apparatus below.    01 02 03 0 5 06 0 40 dilute hydrochloric acid excess magnesiumgas syringe     the volume of hydrogen produced was measured every minute for six minutes.   (a) use the gas syringe diagrams to complete the table.    table of results   time  / minutes gas syringe diagram volume of hydrogen  / cm3 01 02 03 0 5 06 0 400 01 02 03 0 5 06 0 40 01 02 03 0 5 06 0 40 01 02 03 0 5 06 0 40 01 02 03 0 5 06 0 40 01 02 03 0 5 06 0 40 01 02 03 0 5 06 0 401 2345 6    [4]   ",
            "11": "11  \u00a9 ucles 2008 0620/06/m/j/08 [turn over  for  examiner's  use  (b) plot the results on the grid below. draw a smooth line graph.    70 605040302010 0 0123456volume of hydrogen  / cm3 time  / minutes     [4]     (c) why is the volume of gas given off the same at 5 minutes and 6 minutes?     [1]      (d) which point appears to be inaccurate? explain why.    [2]    (e) sketch on the grid the graph you would expect if the experiment were repeated using  the same volume of acid which was half as concentrated. [2]    [total: 13] ",
            "12": "12    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/06/m/j/08  for  examiner's  use 7 this label is from a container of \u2018bite relief\u2019 solution.        bite relief     for fast relief from insect bites and stings      active ingredient: ammonia   also contains water and alcohol     directions for use: use cotton wool to dab the solution on the affected area  of the skin        (a) give a chemical test to show the presence of ammonia in bite relief solution.  test   result  [2]      (b) what practical method could be used to separate the mixture of alcohol (bp 78\u00b0c) and  water (bp 100\u00b0c)?   [2]     (c) give a chemical test to show the presence of water.  test   result  [2]      (d) what would be the effect of touching the alcohol with a lighted splint?   [1]    [total: 7]     "
        },
        "0620_w08_qp_03.pdf": {
            "1": "location entry codes       as part of cie\u2019s continual commitment to main taining best practice in assessment, cie uses  different variants of some question papers for our most popular assessments with large and  widespread candidature. the question papers are closely related and the relationships between  them have been thoroughly established using our assessment expertise.  all versions of the  paper give assessment of equal standard.     the content assessed by the examination papers and the type of questions is unchanged.   this change means that for this component there are now two variant question papers, mark  schemes and principal examiner\u2019s reports where previously there was only one.  for any individual country, it is intended that only one variant is used.  this document contains both  variants which will give all centres access to even more past examination ma terial than is usually  the case.      the diagram shows the relationship between the question papers, mark schemes and principal examiners\u2019 reports that are available.     question paper   mark scheme  principal examiner\u2019s  report  introduction     introduction   introduction   first variant question paper    first variant mark scheme  first variant principal  examiner\u2019s report    second variant question  paper  second variant mark  scheme    second variant principal  examiner\u2019s report      who can i contact for further information on these changes?  please direct any questions about this to cie\u2019s customer services team at: international@cie.org.uk              the titles for the variant items should correspond with the table above, so that at the top of the  first page of the relevant part of the document and on the header, it has the words:    \u2022 first variant question paper / mark scheme / principal examiner\u2019s report     or     \u2022 second variant question paper / mark scheme / principal examiner\u2019s report      as appropriate.    ",
            "2": "    this document consists of 12 printed pages.  ib08 11_0620_31/6rp  \u00a9 ucles 2008  [turn over      *2942397288* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/31     paper 3 (extended)  october/november 2008     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes   answer all questions. a copy of the periodic table is printed on page 12.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  questions.   ",
            "3": "2  \u00a9 ucles 2008 0620/31/o/n/08  for  examiner's  use 1 complete the following table.      gas test for gas  ammonia    bleaches damp litmus paper  hydrogen    relights a glowing splint   turns limewater milky     [total: 5]     ",
            "4": "3  \u00a9 ucles 2008 0620/31/o/n/08 [turn over  for  examiner's  use 2 there are three types of giant structure \u2013 ionic, metallic and macromolecular.     (a) sodium nitride is an ionic compound. draw a diagram that shows the formula of the compound, the charges on the ions and the arrangement of the valency electrons around the negative ion.    use x to represent an electron from a sodium atom.  use o to represent an electron from a nitrogen atom.                 [3]     (b) (i)  describe metallic bonding.     [3]    (ii) use the above ideas to explain why      metals are good conductors of electricity,   [1]      metals are malleable.   [2]      (c) silicon( iv) oxide has a macromolecular structure.    (i) describe  the structure of silicon( iv) oxide (a diagram is not acceptable).       [3]     (ii) diamond has a similar structure and consequently similar properties.    give two physical properties common to both diamond and silicon( iv) oxide.     [2]     [total: 14] ",
            "5": "4  \u00a9 ucles 2008 0620/31/o/n/08  for  examiner's  use 3 steel is an alloy made from impure iron.     (a) both iron and steel rust. the formula for rust is fe 2o3.2h 2o.    it is hydrated iron( iii) oxide.    (i) name the two substances that must be present for rusting to occur.   [2]     (ii) painting and coating with grease are two methods of preventing iron or steel from  rusting. give two other methods.     [2]       (b) (i)  name a reagent that can reduce iron( iii) oxide to iron.   [1]    (ii) write a symbol equation for the reduction of iron( iii) oxide, fe 2o3, to iron.   [2]     (c) (i)  calculate the mass of one mole of  fe 2o3.2h 2o.   [1]    (ii) use your answer to (i) to calculate the percentage of iron in rust.     [2]     (d) iron from the blast furnace is impure. two of the impurities are carbon and silicon.  these are removed by blowing oxygen through the molten iron and adding calcium  oxide.    (i) explain how the addition of oxygen removes carbon.     [1]     (ii) explain how the addition of oxygen and calcium oxide removes silicon.     [2]     [total: 13]   ",
            "6": "5  \u00a9 ucles 2008 0620/31/o/n/08 [turn over  for  examiner's  use 4 across the world, food safety agencies are investigating the presence of minute traces of  the toxic hydrocarbon, benzene, in soft drinks. it is formed by the reduction of sodium  benzoate by vitamin c.    ingredients orange juice, sodium benzoate, vitamin c      (a) sodium benzoate is a salt, it has the formula c 6h5coona. it can be made by the  neutralisation of benzoic acid by sodium hydroxide.    (i) deduce the formula of benzoic acid.   [1]    (ii) write a word equation for the reaction between benzoic acid and sodium hydroxide.   [1]    (iii) name two other compounds that would react with benzoic acid to form     sodium benzoate.   [2]    (b) benzene contains 92.3% of carbon and its relative molecular mass is 78.    (i) what is the percentage of hydrogen in benzene?   [1]    (ii) calculate the ratio of moles of c atoms: moles of h atoms in benzene.     [2]     (iii) calculate its empirical formula and then  its molecular formula.  the empirical formula of benzene is   the molecular formula of benzene is  [2]  ",
            "7": "6  \u00a9 ucles 2008 0620/31/o/n/08  for  examiner's  use  (c) the structural formula of vitamin c is drawn below.    c cco ccc oh hhhh oho ho oh     (i) what is its molecular formula?   [1]   (ii) name the two functional groups which are circled.   [2]   [total: 12]    ",
            "8": "7  \u00a9 ucles 2008 0620/31/o/n/08 [turn over  for  examiner's  use 5 the electrolysis of concentrated aqueous sodium chloride produces three commercially  important chemicals hydrogen, chlorine and sodium hydroxide.     (a) the ions present are na+(aq), h+(aq) ,c l \u2013(aq) and oh\u2013(aq).     (i) complete the ionic equation for the reaction at the negative electrode (cathode).   +    h2 [1]   (ii) complete the ionic equation for the reaction at the positive electrode (anode).   \u2212     cl2 [1]   (iii) explain why the solution changes from sodium chloride to sodium hydroxide.   [1]      (b) (i)  why does the water supply industry use chlorine?   [1]    (ii) name an important chemical that is made from hydrogen.   [1]    (iii) how is sodium hydroxide used to make soap?   [2]    [total: 7]    ",
            "9": "8  \u00a9 ucles 2008 0620/31/o/n/08  for  examiner's  use 6 the reactivity series lists metals in order of reactivity.     (a) to find out which is the more reactive metal, zinc or tin, the following experiment could be carried out.    tin(ii) nitrate(aq)piece of zinc shiny surface piece of zinc,surface still shinyno reaction (nr) surface of zinc covered with a grey depositreaction (r)      this experiment could be carried out with other metals and the results recorded in a  table. then the order of reactivity can be deduced.    (i) the order was found to be:   manganese most reactive  zinc   tin   silver least reactive   complete the table of results from which this order was determined.    aqueous   solution tin  sn manganese   mn silver   ag zinc zn  tin(ii) nitrate  r nr r  manganese( ii) nitrate      silver( i) nitrate      zinc nitrate       [3]     (ii) write the ionic equation for the reaction between tin atoms and silver( i) ions.   [2]   ",
            "10": "9  \u00a9 ucles 2008 0620/31/o/n/08 [turn over  for  examiner's  use  (iii) the following is a redox reaction.    mn  +  sn2+    mn2+  +  sn     indicate on the equation the change which is oxidation.   give a reason for your choice.   [2]    (iv) explain why experiments of this type cannot be used to find the position of aluminium in the reactivity series.     [2]      (b) potassium and calcium are very reactive metals at the top of the series. because their ions have different charges, k + and ca2+, their compounds behave differently when  heated.    (i) explain why the ions have different charges.     [2]   (ii) their hydroxides are heated.    if the compound decomposes, complete the word equation.    if it does not decompose, write \u201cno reaction\u201d.  potassium hydroxide     calcium hydroxide    [2]   (iii) complete the equations for the decomposition of their nitrates.  2kno 3    +   2ca(no 3)2    +  +  [4]   [total: 17]     ",
            "11": "10  \u00a9 ucles 2008 0620/31/o/n/08  for  examiner's  use 7 the alkanes are generally unreactive. their reactions include combustion, substitution and  cracking.    (a) the complete combustion of an alkane gives carbon dioxide and water.     (i) 10  cm3 of butane is mixed with 100  cm3 of oxygen, which is an excess. the mixture  is ignited. what is the volume of unreacted oxygen left and what is the volume of  carbon dioxide formed?    c4h10(g)  +  (g) o 62 21    4co 2(g)  +  5h 2o(l)    volume of oxygen left =  cm3  volume of carbon dioxide formed =  cm3 [2]   (ii) why is the incomplete combustion of any alkane dangerous, particularly in an  enclosed space?     [2]      (b) the equation for a substitution reaction of butane is given below.    ch 3\u2212ch 2\u2212ch 2\u2212ch 3  +  c l2    ch 3\u2212ch 2\u2212ch 2\u2212ch 2 \u2212cl  +  hc l    (i) name the organic product.   [1]   (ii) this reaction does not need increased temperature or pressure.   what is the essential reaction condition?   [1]   (iii) write a different equation for a substituti on reaction between butane and chlorine.   [1]    ",
            "12": "11  \u00a9 ucles 2008 0620/31/o/n/08 for  examiner's  use  (c) alkenes are more reactive and industrially more useful than alkanes.   they are made by cracking alkanes.    c7h16    ch 3\u2212ch=ch 2  +  ch 3\u2212ch 2\u2212ch=ch 2 + h 2   heptane propene but\u22121\u2212ene     (i) draw the structural formula of the polymer poly(propene).                 [2]    (ii) give the structural formula and name of the alcohol formed when but-1-ene reacts with steam.  name  [1]   structural formula          [1]     (iii) deduce the structural formula of the product formed when propene reacts with hydrogen chloride.              [1]     [total: 12]     ",
            "13": "12    permission to reproduce items where third-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/31/o/n/08  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  ",
            "14": "    this document consists of 12 printed pages.  ib08 11_0620_03_tz/4rp  \u00a9 ucles 2008  [turn over      *7507316830* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/32     paper 3 (extended)  october/november 2008     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes   answer all questions. a copy of the periodic table is printed on page 12.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  questions.   ",
            "15": "2  \u00a9 ucles 2008 0620/32/o/n/08  for  examiner's  use 1 complete the following table.      gas test for gas   turns damp red litmus paper blue   bleaches damp litmus paper  hydrogen   oxygen   carbon dioxide      [total: 5]     ",
            "16": "3  \u00a9 ucles 2008 0620/32/o/n/08 [turn over  for  examiner's  use 2 there are three types of giant structure \u2013 ionic, metallic and macromolecular.     (a) sodium sulphide is an ionic compound. draw a diagram that shows the formula of the compound, the charges on the ions and the arrangement of the valency electrons around the negative ion.    use x to represent an electron from a sodium atom.  use o to represent an electron from a sulphur atom.               [3]    (b) (i)  describe metallic bonding.     [3]      (ii) use the above ideas to explain why     metals are good conductors of electricity,   [1]      metals are malleable.   [2]     (c) silicon( iv) oxide has a macromolecular structure.     (i) describe  the structure of silicon( iv) oxide (a diagram is not acceptable).       [3]     (ii) diamond has a similar structure and consequently similar properties.    give two physical properties common to both diamond and silicon( iv) oxide.     [2]     [total: 14] ",
            "17": "4  \u00a9 ucles 2008 0620/32/o/n/08  for  examiner's  use 3 steel is an alloy made from impure iron.     (a) both iron and steel rust. the formula for rust is fe 2o3.2h 2o.    it is hydrated iron( iii) oxide.    (i) name the two substances that must be present for rusting to occur.   and  [2]    (ii) painting and coating with grease are two methods of preventing iron or steel from rusting. give two other methods.     [2]      (b) (i)  name a reagent that can reduce iron( iii) oxide to iron.   [1]   (ii) write a symbol equation for the reduction of iron( iii) oxide, fe 2o3, to iron.   [2]     (c) (i)  calculate the mass of one mole of  fe 2o3.2h 2o.   [1]   (ii) use your answer to (i) to calculate the percentage of water in rust.     [2]     (d) iron from the blast furnace is impure. two of the impurities are carbon and silicon.  these are removed by blowing oxygen through the molten iron and adding calcium  oxide.     (i) explain how the addition of oxygen removes carbon.     [1]    (ii) explain how the addition of oxygen and calcium oxide removes silicon.     [2]    [total: 13] ",
            "18": "5  \u00a9 ucles 2008 0620/32/o/n/08 [turn over  for  examiner's  use 4 across the world, food safety agencies are investigating the presence of minute traces of  the toxic hydrocarbon, benzene, in soft drinks. it is formed by the reduction of sodium benzoate by vitamin c.    ingredients orange juice, sodium benzoate, vitamin c     (a) sodium benzoate is a salt, it has the formula c 6h5coona. it can be made by the  neutralisation of benzoic acid by sodium hydroxide.    (i) deduce the formula of benzoic acid.   [1]   (ii) write a word equation for the reaction between benzoic acid and sodium hydroxide.   [1]   (iii) name two other compounds that would react with benzoic acid to form     sodium benzoate.   [2]  ",
            "19": "6  \u00a9 ucles 2008 0620/32/o/n/08  for  examiner's  use  (b) benzene contains 92.3% of carbon and its relative molecular mass is 78.     (i) what is the percentage of hydrogen in benzene?   [1]   (ii) calculate the ratio of moles of c atoms: moles of h atoms in benzene.     [2]    (iii) calculate its empirical formula and then  its molecular formula.  the empirical formula of benzene is   the molecular formula of benzene is  [2]    (c) the structural formula of vitamin c is drawn below.    c cco ccc oh hhhh oho ho oh     (i) what is its molecular formula?   [1]   (ii) name the two functional groups which are circled.   [2]   [total: 12]   ",
            "20": "7  \u00a9 ucles 2008 0620/32/o/n/08 [turn over  for  examiner's  use 5 the electrolysis of concentrated aqueous sodium chloride produces three commercially  important chemicals; hydrogen, chlorine and sodium hydroxide.     (a) the ions present are na+(aq), h+(aq) ,c l \u2013(aq) and oh\u2013(aq).     (i) complete the ionic equation for the reaction at the negative electrode (cathode).   +    h2 [1]   (ii) complete the ionic equation for the reaction at the positive electrode (anode).  2c l  \u2013 \u2212   [1]   (iii) explain why the solution changes from sodium chloride to sodium hydroxide.   [1]     (b) (i)  why does the water supply industry use chlorine?   [1]    (ii) name an important chemical that is made from hydrogen.   [1]    (iii) sodium hydroxide reacts with fats to make soap and glycerine    what type of compound are fats?   [1]    what type of the reaction is this?   [1]   [total : 7]   ",
            "21": "8  \u00a9 ucles 2008 0620/32/o/n/08  for  examiner's  use 6 the reactivity series lists metals in order of reactivity.     (a) to find out which is the more reactive metal, zinc or tin, the following experiment could be carried out.    tin(ii) nitrate(aq)piece of zinc shiny surface piece of zinc,surface still shinyno reaction (nr) surface of zinc covered with a grey depositreaction (r)      this experiment could be carried out with other metals and the results recorded in a  table.  then the order of reactivity can be deduced.    (i) the order was found to be:   manganese most reactive  zinc   tin   silver least reactive   complete the table of results from which this order was determined.    aqueous   solution tin  sn manganese   mn silver   ag zinc zn  tin( ii) nitrate  r nr r  manganese( ii) nitrate      silver( i) nitrate      zinc nitrate       [3]     (ii) write the equation for the reaction between zinc and silver( i) nitrate.   [2] ",
            "22": "9  \u00a9 ucles 2008 0620/32/o/n/08 [turn over  for  examiner's  use  (iii) the following is a redox reaction.    mn  +  sn2+    mn2+  +  sn     indicate on the equation which reagent is the oxidant or oxidizing agent.   give a reason for your choice.   [2]    (iv) explain why experiments of this type cannot be used to find the position of aluminium in the reactivity series.     [2]     (b) potassium and calcium are very reactive metals at the top of the series.  because their ions have different charges, k + and ca2+, their compounds behave differently when  heated.    (i) explain why the ions have different charges.     [2]    (ii) their hydroxides are heated.    if the compound decomposes, complete the word equation.    if it does not decompose, write \u201cno reaction\u201d.  potassium hydroxide     calcium hydroxide    [2]   (iii) complete the equations for the decomposition of their nitrates.  2kno 3    +    2ca(no 3)2    +  +  [4]   [total: 17]   ",
            "23": "10  \u00a9 ucles 2008 0620/32/o/n/08  for  examiner's  use 7 the alkanes are generally unreactive. their reactions include combustion, substitution and  cracking.    (a) the complete combustion of an alkane gives carbon dioxide and water.     (i) 20  cm3 of butane is mixed with 150  cm3 of oxygen, which is an excess.  the mixture  is ignited. what is the volume of unreacted oxygen left and what is the volume of  carbon dioxide formed?    c4h10(g)  +  61 2o2 (g)    4co 2(g)  +  5h 2o (l)    volume of oxygen left =  cm3  volume of carbon dioxide formed =  cm3 [2]   (ii) why is the incomplete combustion of any alkane dangerous, particularly in an enclosed space?     [2]     (b) the equation for a substitution reaction of butane is given below.    ch 3\u2212ch 2\u2212ch 2\u2212ch 3  +  c l2    ch 3\u2212ch 2\u2212ch 2\u2212ch 2 \u2212cl  +  hc l    (i) name the organic product.   [1]    (ii) this reaction does not need increased temperature or pressure.   what is the essential reaction condition?   [1]    (iii) write a different equation for a substituti on reaction between butane and chlorine.   [1] ",
            "24": "11  \u00a9 ucles 2008 0620/32/o/n/08 [turn over  for  examiner's  use  (c) alkenes are more reactive and industrially more useful than alkanes.   they are made by cracking alkanes.    c7h16    ch 3\u2212ch=ch 2  +  ch 3\u2212ch 2\u2212ch=ch 2 + h 2   heptane propene but\u22121\u2212ene     (i) draw the structural formula of the polymer poly(propene).                 [2]    (ii) give the structural formula and name of the alcohol formed when propene reacts with steam.  name  [1]   structural formula          [1]     (iii) deduce the structural formula of the pr oduct formed when but\u22121\u2212ene reacts with  hydrogen chloride.              [1]     [total: 12]       ",
            "25": "12    permission to reproduce items where third-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/32/o/n/08  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w08_qp_1.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib08 11_0620_01/rp  \u00a9 ucles 2008  [turn over      *6400528663* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/01     paper 1 multiple choice  october/november 2008     45 minutes  additional materials: multiple choice answer sheet  soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2008 0620/01/o/n/08  1 in which substance are the particles furthest apart at room temperature?  a ethanol  b methane  c salt  d sugar      2 an experiment is carried out to separate a mixture of two dyes. a line is drawn on a piece of  chromatography paper and a spot of the dye mixture placed on it. the paper is dipped into a  solvent and left for several minutes.    spot of mixtureof dyesbeaker solventsolvent levelpaper line     which statement about this experiment is correct?  a the dyes must differ in their boiling points.  b the dyes must differ in their solubilities in the solvent.  c the line must be drawn in ink.  d the line must be placed below the level of the solvent.      3 an aqueous solution contains barium iodide.    it is possible to obtain a solution that contains ba2+(aq) but no i\u2013(aq) by adding \u2026\u20261\u2026\u2026 until no  more \u2026\u20262\u2026\u2026 precipitate forms.    which words correctly complete gaps 1 and 2?     1 2  a aqueous lead( ii) nitrate white  b aqueous lead( ii) nitrate yellow  c dilute sulphuric acid white  d dilute sulphuric acid yellow     ",
            "3": "3  \u00a9 ucles 2008 0620/01/o/n/08 [turn over  4 a solid mixture contains an ionic salt, x, and a covalent organic compound, y.    two students suggested methods of separating the mixture as shown.    1 2shake with water x + yy solutionof x shake withethanol x + yx solutionof y     which methods of separation are likely to work?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      5 what do the nuclei in hydrogen molecules contain?  a electrons and neutrons  b electrons and protons  c neutrons only  d protons only    ",
            "4": "4  \u00a9 ucles 2008 0620/01/o/n/08  6 the diagram shows part of the periodic table.    w yx z     which element is correctly matched with its electronic structure?     element electronic structure  a w 2,8,1  b x 2,4  c y 2,8,2  d z 2,8    7 which of the following compounds exist?    raar rbbr  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    8 which particle is an ion?     number of  protons number of  neutrons number of  electrons  a 1 0 1  b 3 4 3  c 6 6 6  d 11 12 10     ",
            "5": "5  \u00a9 ucles 2008 0620/01/o/n/08 [turn over  9 the diagram shows a molecule of hydrogen fluoride.    f h     in the molecule hydrogen fluoride, hf,  a the hydrogen and fluorine share a pair of electrons.  b the hydrogen and fluorine share a pair of protons.  c the hydrogen gives the fluorine an electron.  d the hydrogen gives fluorine a proton.     10 lead( ii) nitrate can be decomposed as shown.    xpb(no 3)2 \u2192 ypbo + zno 2 + o 2    which numbers x, y and z balance the equation?     x y z  a 2 2 2  b 2 2 4  c 2 4 4  d 4 4 2      11 carbon and chlorine form a chloride.    what is the formula of this chloride?  a ccl 2 b ccl 4 c cac l2 d cac l4    ",
            "6": "6  \u00a9 ucles 2008 0620/01/o/n/08  12 which diagram shows an experiment in which the bulb lights?    a cable: plastic steel aluminiumb carbon rods bitumen heat d carbon rods sodium chloride crystalsc carbon rods concentrated hydrochloric acid     13 metal x is low in the reactivity series and it is liberated by electrolysis of its bromide.    metal x is \u2026\u20261\u2026\u2026 and the bromide is \u2026\u20262\u2026\u2026 .    which words correctly complete gaps 1 and 2?     1 2  a lead in solution  b lead molten  c sodium in solution  d sodium molten    ",
            "7": "7  \u00a9 ucles 2008 0620/01/o/n/08 [turn over  14 copper and hydrogen can each be formed by electrolysis.    at which electrodes are these elements formed?     copper hydrogen  a anode anode  b anode cathode  c cathode anode  d cathode cathode     15 when solid x is dissolved in water, an endothermic change takes place.    when 5  g of x are dissolved in 1000  cm3 of water, a temperature change of 10  \u00b0c occurs.    which temperature change occurs when 5  g of x are dissolved in 500  cm3 of water?  a a decrease of 20  \u00b0c  b a decrease of 5  \u00b0c  c an increase of 20  \u00b0c  d an increase of 5  \u00b0c    16 the elements h 2 and 235u are both used as fuels.    in these processes, the reactions are \u2026...1\u2026... and \u2026...2\u2026... oxidised.    which words correctly complete gaps 1 and 2?     1 2  a endothermic both elements are  b endothermic only hydrogen is  c exothermic both elements are  d exothermic only hydrogen is      17 in which of the following reactions is the substance printed in bold oxidised?  a burning the wax in a candle  b dissolving hydrogen chloride  in water  c making glucose from carbon dioxide  and water by photosynthesis  d reacting sodium hydroxide  with sulphuric acid    ",
            "8": "8  \u00a9 ucles 2008 0620/01/o/n/08  18 the diagram shows the change from a salt to its hydrated form.    hydrated salt anhydrous saltx y    which labels can be used for x and y?     x y  a + heat + water  b + heat \u2013 water  c + water + heat  d + water \u2013 heat      19 oxygen is formed when manganese( iv) oxide is added to hydrogen peroxide, h 2o2.    2h2o2 \u2192 2h 2o + o 2    in this reaction, the manganese( iv) oxide acts as  a an acid.  b a base.  c a catalyst.  d a drying agent.     20 dilute hydrochloric acid is added to aqueous barium nitrate in a test-tube.    what happens?     the ph of the liquid  in the test-tube a precipitate forms  a decreases yes  b decreases no  c increases yes  d increases no    ",
            "9": "9  \u00a9 ucles 2008 0620/01/o/n/08 [turn over  21 a colourless liquid in an unlabelled bottle is tested as shown.    \u2022 litmus paper turns red.  \u2022 magnesium ribbon fizzed.  \u2022 reaction with aqueous barium nitrate produced a white precipitate.    what is the colourless liquid?  a aqueous sodium hydroxide  b aqueous  sodium sulphate  c dilute hydrochloric acid  d dilute  sulphuric acid     22 the diagrams show two experiments.    experiment 1 red litmus paperblue litmus paper aqueous ammonium chloride + aqueous sodium hydroxide heatexperiment 2 redlitmus paperblue litmus paper aqueous ammonium chloride + dilute sulphuric acid heat     what happens to the pieces of litmus paper?     experiment 1 experiment 2  a blue \u2192 red both pieces bleached  b blue \u2192 red no change  c red \u2192 blue both pieces bleached  d red \u2192 blue no change     ",
            "10": "10  \u00a9 ucles 2008 0620/01/o/n/08  23 which substances react with dilute sulphuric acid to form a salt?     magnesium magnesium  oxide magnesium  carbonate magnesium  chloride  a \u0013 \u0013 \u0013 \u0017  b \u0013 \u0013 \u0017 \u0013  c \u0013 \u0017 \u0013 \u0013  d \u0017 \u0013 \u0013 \u0013     24 which properties of the element titanium, ti, can be predicted from its position in the periodic  table?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0017 \u0013 \u0013 \u0013  b \u0013 \u0017 \u0013 \u0013  c \u0013 \u0013 \u0017 \u0013  d \u0013 \u0013 \u0013 \u0017    25 the table gives information about four elements.    which element could be in group i of the periodic table?     proton number reaction with water  a even reacts  b even no reaction  c odd reacts  d odd no reaction      26 what is the formula of a strontium ion?  a sr2+ b sr  + c sr  \u2013 d sr  2\u2013     ",
            "11": "11  \u00a9 ucles 2008 0620/01/o/n/08 [turn over  27 nichrome is an alloy of the two transition elements nickel and chromium. the alloy is used as the  heating coil in electric fires and electric toasters.    which properties of nichrome are important for these uses?     high melting point resistant to oxidation a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      28 mild steel is an alloy of iron and carbon.    how does the carbon affect the properties of mild steel?  a the carbon makes the alloy a better conductor of electricity than iron.  b the carbon makes the alloy harder than the iron. c the carbon makes the alloy softer than the iron.  d the carbon stops the iron rusting.     29 a new isotope of a divalent metal is discovered. some students are asked to predict its  properties.    which student\u2019s predictions are correct?    student number of electrons  in outer shell bonding in the oxide  a 2 covalent  b 2 ionic  c 6 covalent  d 6 ionic    ",
            "12": "12  \u00a9 ucles 2008 0620/01/o/n/08  30 the diagrams show two experiments to investigate metal reactivity.    experiment 1 experiment 2 hydrogen evolveddilute sulphuric acid metalmetal oxide + carbon limewater goes cloudyheat     in which of these experiments could the metal be copper?     experiment 1 experiment 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      31 which reaction is not a step in the production of iron from hematite in the blast furnace?  a carbon (coke) burning in air to produce carbon dioxide  b carbon monoxide being formed from carbon and carbon dioxide  c iron oxide reacting with carbon monoxide to form iron  d iron reacting with limestone to produce slag     32 which item is sometimes made from stainless steel?    car bodybc food containera d drinks can kitchen sink    ",
            "13": "13  \u00a9 ucles 2008 0620/01/o/n/08 [turn over  33 some pollutant gases are present in the atmosphere because of the combustion of fossil fuels.    for which gases is this statement correct?     co no 2 so 2  a \u0013 \u0013  \u0013  b \u0013 \u0013  \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0013     34 air is a mixture of gases.    which gas is present in the largest amount?  a argon  b carbon dioxide c nitrogen d oxygen     35 the experiment shown in the diagram was set up.    which tube had the highest water level after one month?    ironcd oxygen airironab hydrogennitrogen trough water     36 an excess of fertiliser on a field can be dissolved by rain water and washed into streams and  rivers. fertiliser can then find its way into water supplies.    which process at the water works, if any, would remove this fertiliser?     filtration chlorination  a no no  b no yes  c yes no  d yes yes ",
            "14": "14  \u00a9 ucles 2008 0620/01/o/n/08  37 when added in turn to four solutions, aqueous sodium carbonate gives the following results.    which solution is acidic?    solution result  a a blue precipitate forms  b a white precipitate forms  c bubbles of gas form  d no visible reaction occurs     38 which products are obtained by the cracking of an alkane?     alkene hydrogen water  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0013      39 a compound takes part in an addition reaction.    how does its name end?  a \u2026..ane  b \u2026..ene  c \u2026..ol  d \u2026..oic acid     40 when glucose is fermented, ethanol is formed together with  a carbon dioxide.  b ethene.  c methane.  d oxygen.    ",
            "15": "15   0620/01/o/n/08  blank page",
            "16": "16    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/01/o/n/08  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w08_qp_2.pdf": {
            "1": "    this document consists of 16 printed pages.  ib08 11_0620_02/6rp  \u00a9 ucles 2008  [turn over      *0269167397* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/02     paper 2  october/november 2008     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name in the spaces at the top of this page.  write in dark blue or black pen. you may need to use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2008 0620/02/o/n/08  for  examiner's  use 1 (a) the table gives some information about five elements, a, b, c, d and e.   complete the table by writing either metal or non-metal in the last column.    element properties metal or non-metal  a shiny solid which conducts electricity   b reddish brown liquid with a low boiling point   c a form of carbon which is black in colour and conducts electricity   d white solid which is an insulator and has a high melting point   e dull yellow solid which does not conduct heat     [5]     (b) describe how metallic character changes across a period.   [1]       (c) sodium is in group i of the periodic table.    (i) draw a diagram to show the full electronic structure of sodium.                      [1]    (ii) complete the equation to show what happens when a sodium atom forms a sodium ion.    na     na+ +    [1]  ",
            "3": "3  \u00a9 ucles 2008 0620/02/o/n/08 [turn over  for  examiner's  use  (d) complete these sentences about the properties of the group i elements using words  from the list.    acidic  basic   decrease   hard    increase  lithium  potassium soft    the group i elements are relatively  metals which  in  reactivity going down the group. sodium reacts more violently with water than  . the group i metals all form  oxides. [4]    [total: 12]    ",
            "4": "4  \u00a9 ucles 2008 0620/02/o/n/08  for  examiner's  use 2 (a)  match up the atmospheric pollutants on the left with their main source on the right.   the first one has been done for you.    chlorofluorocarbons car exhausts sulphur dioxide aerosol sprays carbon monoxidecombustion of fossil fuels containing sulphur nitrogen oxidesincomplete combustion of fossil fuels   [3]    (b) one stage in the manufacture of sulphuric acid involves the oxidation of sulphur dioxide by oxygen in the air to form sulphur trioxide.    2so 2  +  o 2    2so 3    (i) explain how this reaction shows that sulphur dioxide is oxidized.   [1]    (ii) what is the percentage of oxygen in clean air?  [1]   (iii) sulphuric acid is used to make the fertiliser ammonium sulphate.    ammonia  +  sulphuric acid     ammonium sulphate    what type of reaction is this?   [1]   ",
            "5": "5  \u00a9 ucles 2008 0620/02/o/n/08 [turn over  for  examiner's  use  (iv) why do farmers need to use fertilisers?     [2]     (v) another fertiliser can be made by the reaction of ammonia with nitric acid.   state the chemical name of this fertiliser.   [1]    [total: 9]    ",
            "6": "6  \u00a9 ucles 2008 0620/02/o/n/08  for  examiner's  use 3 calcium carbonate, caco 3, is the raw material used in the manufacture of lime, cao.     (a) (i)  describe how lime is manufactured from calcium carbonate.   [1]    (ii) write a symbol equation for this reaction.             [1]    (iii) state one large scale use of lime.   [1]     (b) a student investigated the speed of reaction of calcium carbonate with hydrochloric acid  using the apparatus shown below.    (i) complete the labelling of the apparat us by filling in the three boxes. [3]    reaction mixturewater bath at 40  \u00b0c     (ii) the equation for the reaction is    caco 3  +  2hcl    cac l2  +  co 2  +  h 2o     write the word equation for this reaction.          [2]",
            "7": "7  \u00a9 ucles 2008 0620/02/o/n/08 [turn over  for  examiner's  use  (iii) the student carried out the reaction at 40\u00b0c using large pieces of calcium  carbonate. the results of the experiment are shown below.    80 604020 0 0 20 40 60 80 100 120 140 160 time  / secondscm3 gas released100      at what time did the reaction stop?   [1]    (iv) the student repeated the experiment using the same mass of powdered calcium  carbonate. all other conditions were kept the same. on the grid above, sketch the  graph for the reaction with calcium carbonate powder. [2]    (v) how does the speed of reaction change when  the concentration of hydrochloric acid is decreased,   the temperature is increased?  [2]      [total: 13]    ",
            "8": "8  \u00a9 ucles 2008 0620/02/o/n/08  for  examiner's  use 4 iron is extracted from its ore in a blast furnace.     (a) state the name of the ore from which iron is extracted.   [1]    (b) the diagram shows a blast furnace.    a b c dcoke + limestone + iron ore firebrick lining air in      (i) which one  of the raw materials is added to the blast furnace to help remove the  impurities from the iron ore?   [1]   (ii) the impurities are removed as a slag. which letter on the diagram shows the slag?   [1]     (c) carbon monoxide is formed in the blast furnace by reaction of coke with oxygen.     (i) complete the equation for this reaction.     c  +       co [2]    (ii) state the adverse affect of carbon monoxide on human health.   [1]    ",
            "9": "9  \u00a9 ucles 2008 0620/02/o/n/08 [turn over  for  examiner's  use  (d) in the hottest regions of the blast furnace the following reaction takes place.    fe2o3  +  3c    2fe  +  3co     which two of these sentences correctly describe this reaction?  tick two boxes.        the iron oxide gets reduced.      the reaction is a thermal decomposition.      the carbon gets oxidised.      the carbon gets reduced.      carbon neutralises the iron oxide.   [1]     (e) aluminium cannot be extracted from aluminium oxide in a blast furnace.    explain why aluminium cannot be extracted in this way.     [2]       (f) (i)  state the name of the method used to extract aluminium from its oxide ore.   [1]   (ii) state one use of aluminium.   [1]    [total: 11]    ",
            "10": "10  \u00a9 ucles 2008 0620/02/o/n/08  for  examiner's  use 5 the apparatus shown below can be used to measure the energy released when a liquid fuel  is burnt. the amount of energy released is calculated from the increase in temperature of a known amount of water.    iron can water ethanol      (a) (i)  explain how this experiment shows that the burning of ethanol is an exothermic  reaction.   [1]    (ii) complete the word equation for the complete combustion of ethanol.  ethanol  +  oxygen     +  [2]     (b) ethanol is a fuel containing carbon.   state the names of two other commonly used fuels containing carbon.   and  [2]      (c) give the formula of the functional group present in ethanol.   [1]      (d) the can contains water. describe a chemical test for water.  test   result  [2]     ",
            "11": "11  \u00a9 ucles 2008 0620/02/o/n/08 [turn over  for  examiner's  use  (e) the iron can used in this experiment rusts easily.     (i) describe a method which can be used to prevent iron from rusting.   [1]    (ii) rust contains hydrated iron( iii) oxide.   what do you understand by the term hydrated ?   [1]     (iii) iron is a transition metal. state two properties which are typical of transition metals.     [2]     [total: 12]    ",
            "12": "12  \u00a9 ucles 2008 0620/02/o/n/08  for  examiner's  use 6 the compound shown below is the first member of the alkane homologous series.    h hch h      (a) state two characteristics of a homologous series.     [2]    (b) name and draw the structure of the next member of the alkane homologous series.  name     structure               [2]     (c) complete the table to show the structure and uses of some organic compounds.    name of  compound molecular formula structure  (showing all atoms and bonds) use  ethene c 2h4    ethanoic acid c 2h4o2   making esters  dibromoethane  br hcc hbr hh     ch 4 h hch h     [6]",
            "13": "13  \u00a9 ucles 2008 0620/02/o/n/08 [turn over  for  examiner's  use  (d) calculate the relative molecular mass of dibromoethane.            [1]     [total: 11]   ",
            "14": "14  \u00a9 ucles 2008 0620/02/o/n/08  for  examiner's  use 7 the diagram shows the structures of calcium chloride, calcium and chlorine.    caca caca cacaca cacaca ca ca2+cl \u2013cl \u2013 ca2+cl \u2013cl \u2013ca2+cl \u2013cl \u2013 ca2+cl \u2013cl \u2013 cl clclclclcl cl cl calcium chloride calcium chlorine     (a) use ideas about structure and bonding to explain the following:    (i) calcium chloride conducts electricity when molten but not when solid.       [2]     (ii) at room temperature, calcium is a solid but chlorine is a gas.       [2]     ",
            "15": "15  \u00a9 ucles 2008 0620/02/o/n/08 for  examiner's  use  (b) calcium is manufactured by the electrolysis of molten calcium chloride.    calcium\u2013 + molten calcium chloridewater-cooledsteel cathode      (i) state the products formed  at the anode,   at the cathode.  [2]     (ii) suggest a non-metal that can be used as an anode in this electrolysis.   [1]     (iii) a stream of inert gas is blown over the calcium as it is removed from the molten  calcium chloride.   suggest why a stream of inert gas is blown over the hot calcium.   [1]    (iv) state the name of a gas which is inert.   [1]     (c) aqueous sodium hydroxide or aqueous ammonia can be used to test for calcium ions in  solution.   describe the results of these tests  with aqueous sodium hydroxide,    [2]  with aqueous ammonia.    [1]     [total: 12]   ",
            "16": "16    permission to reproduce items where thir d-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/02/o/n/08   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulphur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w08_qp_5.pdf": {
            "1": "    this document consists of 7 printed pages and 1 blank page.  ib08 11_0620_05/4rp  \u00a9 ucles 2008  [turn over      *5942113768* for examiner's use  1   2   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/05     paper 5  practical test  october/november 2008     1 hour 15 minutes    candidates answer on the question paper .    additional materials: as listed in confidential instructions      read these instructions first    write your, centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes   answer all questions.  practical notes are provided on page 8.   at the end of the examination, fasten all you work securely together.  the number of marks is given in brackets [  ] at the end of each question or part question.   ",
            "2": "2  \u00a9 ucles 2008 0620/05/o/n/08  for  examiner's  use 1 you are going to investigate the addition of four different solids, a, b, c and d, to water.   4 g of each solid will be used.     read all the instructions below carefully before  starting the experiments.     instructions      experiment 1    by using a measuring cylinder, pour 30  cm3 of distilled water into one of the polystyrene  cups provided. measure the initial temperature of the water and record it in the table below. add solid a to the water in the cup and stir the mixture with the thermometer. record the  temperature reached after 2 minutes.   remove the thermometer and rinse with water.   experiment 2    repeat experiment 1 using solid b instead of solid a and a clean polystyrene cup. record  the initial and final temperatures in the table.   keep the solution for experiment 5.    experiment 3     repeat experiment 1, using solid c and a clean polystyrene cup. record the temperatures    in the table.     experiment 4    repeat experiment 1 using solid d and a clean polystyrene cup. record the temperatures    in the table.     experiment 5    pour about 2  cm3 of the solution from experiment 2 into a test-tube. by using a teat pipette  add a little of the solution from experiment 4 to the test-tube. record your observations.     [2]      table of results    experiment initial temperature  / \u00b0c final temperature  / \u00b0c difference  / \u00b0c  1     2     3     4      [5] ",
            "3": "3  \u00a9 ucles 2008 0620/05/o/n/08 [turn over  for  examiner's  use  (a) draw a labelled bar chart of the results to experiments 1, 2, 3 and 4 on the grid below.    temperature difference  / \u00b0c+15 +10 +5 0 \u20135 \u201310\u201315      [4]     use your results and observations to answer the following questions.   (b) (i)  which solid dissolves in water to produce an exothermic reaction?   [1]    (ii) give a reason why you chose this solid.   [1]     (c) which experiment produced the largest temperature change?   [1]    ",
            "4": "4  \u00a9 ucles 2008 0620/05/o/n/08  for  examiner's  use  (d) predict the temperature change that would happen if     (i) 8 g of solid b were used in experiment 2,   [1]    (ii) 60  cm3 of water was used in experiment 4.   [1]   (iii) explain your answer to (d)(ii) .     [2]      (e) suggest an explanation for the observations to experiment 5.     [2]    [total: 20]     ",
            "5": "5  \u00a9 ucles 2008 0620/05/o/n/08 [turn over  for  examiner's  use 2 you are provided with two solutions k and l, each containing the same anion but different  metal cations.   carry out the following tests on the solutions, recording all of your observations in the table.  do not write any conclusions in the table.    tests observations        [1]      (a) describe the appearance of the  solutions.     solution k     solution l  ph    ph  [1]     (b) using universal indicator paper  test the ph of each solution.    solution k    solution l     [2]        [2]      [1]tests on solution k     (c) (i) by using a teat pipette add  drops of aqueous sodium  hydroxide to about 3  cm3 of  solution k. now add  excess aqueous sodium hydroxide to the test-tube.      (ii) repeat experiment (c)(i)   using aqueous ammonia  instead of aqueous sodium  hydroxide.         (iii) to about 3  cm3 of solution  k add a few drops of hydrochloric acid and about  1  cm3 of barium chloride  solution.  ",
            "6": "6  \u00a9 ucles 2008 0620/05/o/n/08  for  examiner's  use tests observations   [2]   (iv) to about 3  cm3 of solution  k add a few drops of nitric  acid and about 1  cm3 of  silver nitrate solution.   [2] tests on solution l    (d) (i) repeat experiment (c)(i)   using about 3  cm3 of  solution l.   [1]         [1]         [2]    (ii) repeat experiment (c)(ii)   using about 3  cm3 of  solution l.     (iii) repeat experiment (c)(iii)   using about 3  cm3 of  solution l.      (iv) repeat experiment (c)(iv)   using about 3  cm3 of  solution l.     (e) what does test (b) indicate?   [1]      (f) identify the anion present in solutions k and l.   [1]      (g) identify the metal cation present in    (i) solution k,   [1]     (ii) solution l.   [2]   [total: 20] ",
            "7": "7    permission to reproduce items where third-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/05/o/n/08 blank page",
            "8": "8  \u00a9 ucles 2008 0620/05/o/n/08  notes for use in qualitative analysis     test for anions     anion test test result  carbonate (co 32\u2013) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then aqueous lead( ii) nitrate yellow ppt.  nitrate (no\u2212 3)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulphate (so 42\u2013)  [in solution] acidify with dilute nitric acid, then aqueous barium nitrate white ppt.    test for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh+ 4) ammonia produced on warming -  calcium (ca2+) white., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution    test for gases     gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_w08_qp_6.pdf": {
            "1": "    this document consists of 11 printed pages and 1 blank page.  ib08 11_0620_06/5rp  \u00a9 ucles 2008  [turn over      *9723414007* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/06     paper 6 alternative to practical  october/november 2008     1 hour    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your, centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes   answer all questions.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2008 0620/06/o/n/08  for  examiner's  use 1 the colours present in some blackcurrant sweets can be separated by chromatography.  the colours are water-soluble dyes.   the diagrams show how the colours can be extracted from the sweets.        (a) complete the empty boxes to name the pieces of apparatus. [3]     the apparatus below was used to carry out the chromatography.    beakerglass cover solventchromatography paper      (b) (i)  name the solvent used.   [1]   (ii) label, with an arrow, the origin on the diagram. [1]    (c) sketch, in the box, the chromatogram you would expect if two different colours were  present in the sweets.       [1]   [total: 6] ",
            "3": "3  \u00a9 ucles 2008 0620/06/o/n/08 [turn over  for  examiner's  use 2 electricity was passed through a concentrated solution of sodium chloride containing  universal indicator.     +\u2013 positive electrodenegative electrode concentrated aqueous sodiumchloride anduniversal indicato rcarbon rods       (a) suggest a suitable material for the electrodes.   [1]    three observations were noted:     1 bubbles of gas seen immediately at the negative electrode.  2 bubbles of gas formed after some time at the positive electrode.  3 the solution turned blue around the negative electrode and colourless near the  positive electrode.     (b) give a test to show that the gas observed in 1 is hydrogen.  test   result  [2]      (c) suggest why bubbles of gas were not seen immediately in 2.     [1]     (d) what causes the colour change in 3 at  the negative electrode,   the positive electrode?  [2]    [total: 6] ",
            "4": "4  \u00a9 ucles 2008 0620/06/o/n/08  for  examiner's  use 3 ethene gas was formed by the cracking of a liquid alkane. the diagram shows the  apparatus used.    liquid alkane on mineralfibrealuminiumoxide very strong heatethene      (a) identify two mistakes in the diagram.  1    [1]  2    [1]      (b) describe a test to show the presence of ethene.  test   result  [2]    [total: 4]     ",
            "5": "5  \u00a9 ucles 2008 0620/06/o/n/08 [turn over  for  examiner's  use 4 a student investigated the addition of four different solids, a, b, c and d, to water.   five experiments were carried out.     experiment 1    by using a measuring cylinder, 30  cm3 of distilled water was poured into a polystyrene cup  and the initial temperature of the water was measured. 4  g of solid a was added to the cup  and the mixture stirred with a thermometer. the temperature of the solution was measured  after 2 minutes.    30 25 2030 25 20 initial temperature final temperature     experiment 2    experiment 1 was repeated using 4  g of solid b.     30 25 2030 25 20 initial temperature final temperature     experiment 3    experiment 1 was repeated using 4  g of solid c.     30 25 2020 15 10 initial temperature final temperature   ",
            "6": "6  \u00a9 ucles 2008 0620/06/o/n/08  for  examiner's  use  experiment 4     experiment 1 was repeated using 4  g of solid d.     30 25 2030 25 20 initial temperature final temperature     experiment 5    a little of the solution from experiment 4 was added to a little of the solution from  experiment 2 in a test-tube. the observations were recorded.     observations  a fast reaction. vigorous effervescence and bubbles produced.      (a) use the thermometer diagrams for experiments 1-4 to record the initial and final  temperatures in table 4.1.    calculate and record the temperature difference in table 4.1.   table 4.1    experiment initial temperature  / \u00b0c final temperature  / \u00b0c difference  / \u00b0c  1     2     3     4      [4]   ",
            "7": "7  \u00a9 ucles 2008 0620/06/o/n/08 [turn over  for  examiner's  use  (b) draw a labelled bar chart of the results to experiments 1, 2, 3 and 4 on the grid below.    +10 +5 0 \u20135 \u201310temperature difference  / \u00b0c      [4]     use the results and observations from experiments 1-5 to answer the following questions.     (c) (i)  which solid dissolves in water to produce an exothermic reaction?   [1]     (ii) give a reason why you chose this solid.   [1]    (d) which experiment produced the largest temperature change?   [1]     (e) predict the temperature change that would happen if     (i) 8 g of solid b were used in experiment 2,   [1]     (ii) 60  cm3 of water was used in experiment 4.   [1]    (iii) explain your answer to (e)(ii) .     [2]    (f) suggest an explanation for the observations in experiment 5.     [2]     [total: 17] ",
            "8": "8  \u00a9 ucles 2008 0620/06/o/n/08  for  examiner's  use 5 two salt solutions k and l were analysed. each contained the same chloride anion but  different metal cations. k was a copper( ii) salt.   the tests on the solutions and some of the obse rvations are in the following table. complete  the observations in the table.    tests observations   [1]  yellow  (a) appearance of the solutions.          solution k       solution l  ph 3   ph 2      (b) the ph of each solution was  tested.    solution k    solution l         [2]  drops  [1]  excess     [2]   [1]  tests on solution k    (c) (i)  drops of aqueous sodium  hydroxide were added to solution k. excess  aqueous sodium hydroxide was then added to the test-tube.        (ii) experiment (c)(i)  was  repeated using aqueous  ammonia instead of  aqueous sodium  hydroxide.       (iii) a few drops of  hydrochloric acid and  about 1  cm3 of barium  chloride solution were  added to a little of solution  k.  ",
            "9": "9  \u00a9 ucles 2008 0620/06/o/n/08 [turn over  for  examiner's  use tests observations   [1]   (iv) a few drops of nitric acid  and about 1  cm3 of silver  nitrate solution were  added to a little of solution  k.  red - brown precipitate     red \u2013 brown precipitate       [1]      [1] tests on solution l       (d) (i) experiment (c)(i)  was  repeated using solution l.         (ii) experiment (c)(ii)  was  repeated using solution l.       (iii) experiment (c)(iii)  was  repeated using solution l.      (iv) experiment (c)(iv)  was  repeated using solution l.       (e) what does test (b) indicate?   [1]     (f) identify the metal cation present in solution l.   [2]    [total: 13]    ",
            "10": "10  \u00a9 ucles 2008 0620/06/o/n/08  for  examiner's  use 6 an experiment was carried out to determine the solubility of potassium chlorate at different  temperatures. the solubility is the mass of potassium chlorate that dissolves in 100  g of  water.   the results obtained are shown in the table below.    temperature  / \u00b0c 0 10 20 30 40 50 60  solubility in g  / 100  g water 14 17 20 24 29 34 40     (a) on the grid, draw a smooth line graph to show the solubility of potassium chlorate at different temperatures.    50 40302010 0 0 1 02 03 04 05 06 07 0 temperature  / \u00b0csolubility in g / 100g water      [4]     (b) use your graph to determine the solubility of potassium chlorate at 70  \u00b0c. show clearly  on the graph how you obtained your answer.   [2]     (c) what would be the effect of cooling a saturated solution of potassium chlorate from     60  \u00b0c to 20  \u00b0c?       [2]     [total: 8] ",
            "11": "11  \u00a9 ucles 2008 0620/06/o/n/08 for  examiner's  use 7 a solution of magnesium sulphate can be made by reacting magnesium oxide with warm  sulphuric acid.     (a) describe how you could make a solution of magnesium sulphate starting with  magnesium oxide powder and dilute sulphuric acid.             [3]      (b) describe how you would obtain pure dry crystals of hydrated magnesium sulphate, mgso 4.7h 2o, from the solution of magnesium sulphate in (a).             [3]    [total: 6] ",
            "12": "12    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2008 0620/06/o/n/08  blank page "
        }
    },
    "2009": {
        "0620_s09_qp_1.pdf": {
            "1": "location entry codes       as part of cie\u2019s continual commitment to main taining best practice in assessment, cie uses  different variants of some question papers for our most popular assessments with large and  widespread candidature. the question papers are closely related and the relationships between  them have been thoroughly established using our assessment expertise.  all versions of the  paper give assessment of equal standard.     the content assessed by the examination papers and the type of questions is unchanged.   this change means that for this component there are now two variant question papers, mark  schemes and principal examiner\u2019s reports where previously there was only one.  for any individual country, it is intended that only one variant is used.  this document contains both  variants which will give all centres access to even more past examination ma terial than is usually  the case.      the diagram shows the relationship between the question papers, mark schemes and principal examiners\u2019 reports that are available.     question paper   mark scheme  principal examiner\u2019s  report  introduction     introduction   introduction   first variant question paper    first variant mark scheme  first variant principal  examiner\u2019s report    second variant question  paper  second variant mark  scheme    second variant principal  examiner\u2019s report      who can i contact for further information on these changes?  please direct any questions about this to cie\u2019s customer services team at: international@cie.org.uk              the titles for the variant items should correspond with the table above, so that at the top of the  first page of the relevant part of the document and on the header, it has the words:    \u2022 first variant question paper / mark scheme / principal examiner\u2019s report     or     \u2022 second variant question paper / mark scheme / principal examiner\u2019s report      as appropriate.    ",
            "2": "    this document consists of 15 printed pages and 1 blank page.  ib09 06_0620_01/6rp  \u00a9 ucles 2009  [turn over      *7177477 880* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  may/june 2009       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "3": "2  \u00a9 ucles 2009 0620/11/m/j/09  1 the diagram shows how the molecules in the exhaust gases diffuse into the air.    molecules in air molecules in exhaust gases    which statement describes what happens to these molecules next?  a the molecules fall to the ground because they are heavier than air molecules.  b the molecules go back together as they cool.  c the molecules spread further into the air.  d the molecules stay where they are.     2 a student takes 2  g samples of calcium carbonate and adds them to 20  cm3 samples of dilute  hydrochloric acid at different temperatures. she measures how long it takes for the effervescence  to stop.    which apparatus does she use?     balance clock filter  funnel measuring  cylinder thermometer a \u0013 \u0013 \u0013 \u0013 \u0017  b \u0013 \u0013 \u0017 \u0013 \u0013  c \u0013 \u0017 \u0013 \u0013 \u0013  d \u0017 \u0013 \u0013 \u0017 \u0013    ",
            "4": "3  \u00a9 ucles 2009 0620/11/m/j/09 [turn over  3 the diagram shows the paper chromatograms of four substances, w, x, y and z.    w x y z     which two substances are pure?  a w and x b w and y c x and y d x and z      4 an element s has the proton number 18. the ne xt element in the periodic table is an element t.    which statement is correct?  a element t has one more electron in its outer shell than element s.  b element t has one more electron shell than element s.  c element t is in the same group of the periodic table as element s.  d element t is in the same period of the periodic table as element s.      5 which numbers are added together to give the nucleon number of an ion?  a number of electrons + number of neutrons   b number of  electrons + number of protons  c number of electrons + number of protons + number of neutrons  d number of protons + number of neutrons    ",
            "5": "4  \u00a9 ucles 2009 0620/11/m/j/09  6 the electronic configuration of an ion is 2.8.8.    what could this ion be?     s2\u2013 ca2+  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    7 the diagrams show the structures of two forms, p and q, of a solid element.    pq    what are suitable uses of p and q, based on their structures?     use of solid p use of solid q  a drilling drilling  b drilling lubricating  c lubricating drilling  d lubricating lubricating   8 element v forms an acidic, covalent oxide.    which row in the table shows how many electrons there could be in the outer shell of an atom of  v?    1 2 6 7  a \u0013 \u0017 \u0017 \u0017  b \u0013 \u0013 \u0017 \u0017  c \u0017 \u0017 \u0017 \u0013  d \u0017 \u0017 \u0013 \u0013   ",
            "6": "5  \u00a9 ucles 2009 0620/11/m/j/09 [turn over  9 when sodium chloride is formed from its elements, each chlorine atom \u2026\u20261\u2026\u2026 one \u2026\u20262\u2026\u2026.    which words correctly complete gaps 1 and 2?     1 2  a gains electron  b gains proton  c loses electron  d loses proton    10 nitrogen and hydrogen react together to form ammonia.    n 2 + 3h 2 \u2192 2nh 3    when completely converted, 7 tonnes of nitrogen gives 8.5 tonnes of ammonia.    how much nitrogen will be needed to produce 34 tonnes of ammonia?  a 7 tonnes b 8.5 tonnes c 28 tonnes d 34 tonnes      11 which relative molecular mass, mr, is not correct for the molecule given?     molecule mr  a ammonia, nh 3 17  b carbon dioxide, co 2 44  c methane, ch 4 16  d oxygen, o 2 16   12 aluminium is extracted from its oxide by electrolysis.    the oxide is dissolved in \u2026\u20261\u2026\u2026 cryolite and aluminium is deposited at the \u2026\u20262\u2026\u2026    which words correctly complete gaps 1 and 2?     1 2  a aqueous cathode  b aqueous anode  c molten cathode  d molten anode    ",
            "7": "6  \u00a9 ucles 2009 0620/11/m/j/09  13 molten lead( ii) bromide is electrolysed as shown.    a+\u2013 molten lead(ii) bromide     which ions are discharged at each electrode?     positive electrode negative electrode  a pb+ br2\u2013  b pb2+ br  \u2013  c br2\u2013 pb+  d br \u2013 pb2+     14 which of these elements could be formed at the anode when a molten salt is electrolysed?    a copper  b iodine  c lithium  d strontium    15 the diagram shows some properties that substances may have.    to which labelled part of the diagram does  235u belong?    compoundused as an energy source radioactivea bdc     ",
            "8": "7  \u00a9 ucles 2009 0620/11/m/j/09 [turn over  16 which diagram shows a process in which an endothermic change is taking place?    candlesodiumab c d ice rocket waterwater     17 the equation shows a reaction that is reversed by changing the conditions.    forward reaction  cuso 4.5h 2o \u2192 cuso 4 + 5h 2o    how can the forward reaction be reversed?     by adding water by heating  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    18 the reactions shown may occur in the air during a thunder storm.    n 2 + o 2 \u2192 2no  2no + o 2 \u2192 2no 2  no + o 3 \u2192 no 2 + o 2    which line shows what happens to the reactant molecules in each of these reactions?     n2 no o 3  a oxidised oxidised oxidised  b oxidised oxidised reduced  c reduced reduced oxidised  d reduced reduced reduced    ",
            "9": "8  \u00a9 ucles 2009 0620/11/m/j/09  19 which does not increase the speed of a reaction?  a adding a catalyst  b increasing the concentration of one of the reactants  c increasing the particle size of one of the reactants  d increasing the temperature      20 aqueous sodium hydroxide is added to a solution of a salt. a blue precipitate is formed which  does not dissolve in excess.    aluminium foil is added to the mixture and the mixture is warmed. a gas is produced that turns  damp red litmus paper blue.    what is the name of the salt?  a ammonium nitrate  b ammonium sulfate  c copper( ii) nitrate  d copper( ii) sulfate    21 the graph shows how the ph of soil in a field changed over time.    at which point was the soil neutral?    11 9 753ph of soil timea b cd       22 an element e is burned in air. a white solid oxide is formed.    the oxide is tested with damp red litmus paper. the paper turns blue.    what is element e?  a calcium  b carbon  c iodine  d sulfur ",
            "10": "9  \u00a9 ucles 2009 0620/11/m/j/09 [turn over  23 some reactions of a substance, r, are shown in the diagram.    substance rmagnesium sodium carbonate copper( ii) oxidehydrogen carbon dioxide copper(ii) sulfatereacts with     what type of substance is r ?  a an acid  b a base  c an element  d a salt     24 which statement describes the trends going down group vii of the periodic table?  a the boiling point and melting point both decrease.  b the boiling point and melting point both increase.  c the boiling point decreases but the melting point increases.  d the boiling point increases but the melting point decreases.     25 an inert atmosphere is needed in a lamp to lengthen the useful life of the metal filament.    why is argon, rather than helium, used for this purpose?     argon is more abundant  in the air argon is less dense  than helium  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "11": "10  \u00a9 ucles 2009 0620/11/m/j/09  26 the sulfate of element f is green.    which other properties is element f likely to have?     density melting point  a high high  b high low  c low high  d low low     27 which diagram represents the structure of an alloy?    abcd      28 in a blast furnace, iron( iii) oxide is converted to iron and carbon monoxide is converted to carbon  dioxide.    fe 2o3 + 3co \u2192 2fe + 3co 2    what happens to each of these reactants?  a both iron( iii) oxide and carbon monoxide are oxidised.  b both iron( iii) oxide and carbon monoxide are reduced.  c iron( iii) oxide is oxidised and carbon monoxide is reduced.  d iron( iii) oxide is reduced and carbon monoxide is oxidised.     ",
            "12": "11  \u00a9 ucles 2009 0620/11/m/j/09 [turn over  29 the table gives information about three different metals g, h and j.    does it react with   metal  water steam key  g \u0017 \u0017 \u0013= does react  h \u0013 \u0013 \u0017= does not react  j \u0017 \u0013     what is the order of reactivity of these metals?     most  reactive  least  reactive  a g h j  b h g j  c h j g  d j h g     30 which property do all metals have?  a they are hard.  b they conduct electricity.  c they form acidic oxides.  d they react with water.      31 stainless steel is an alloy of iron and other metals. it is strong and does not rust but it costs much  more than normal steel.    what is not  made from stainless steel?  a cutlery  b pipes in a chemical factory  c railway lines  d saucepans    ",
            "13": "12  \u00a9 ucles 2009 0620/11/m/j/09  32 substance k reacts with sodium carbonate to form a gas.    the gas turns limewater cloudy.    what is substance k and which process takes place in the reaction?     k process  a ethanol combustion  b ethanol neutralisation  c hydrochloric acid combustion  d hydrochloric acid neutralisation      33 an iron nail is placed in a closed test-tube, containing gas l.    the nail rusts.  gas l waternail       what is gas l?  a carbon dioxide  b hydrogen c nitrogen  d oxygen     34 which statements are correct?    1 carbon monoxide is responsible for the production of \u2018acid rain\u2019.  2 oxides of nitrogen are present in car exhausts.  3 sulfur dioxide can be produced by the combustion of fossil fuels.    a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3     ",
            "14": "13  \u00a9 ucles 2009 0620/11/m/j/09 [turn over  35 the diagram shows stages in the purification of water.    which stage uses chlorine?    water at ph9  + bacteria + large solids + fine solids water at ph9+ bacteria+ fine solidswater at ph9+ bacteria water at ph7+ bacteriapure waterat ph7a b  c  d        36 which element is not added to a fertiliser?  a aluminium  b nitrogen  c phosphorus  d potassium      37 a compound has the formula ch 3ch 2ch=ch 2.    which row in the table shows the type of compound and the colour change when aqueous  bromine is added?     type of compound colour change  a saturated brown to colourless  b saturated colourless to brown  c unsaturated brown to colourless  d unsaturated colourless to brown     ",
            "15": "14  \u00a9 ucles 2009 0620/11/m/j/09  38 the diagram shows an industrial process. subst ance m is one of the substances produced by  this process and is used as aircraft fuel.    substance m     what is this process and what is substance m?     process substance m  a fractional distillation paraffin  b fractional distillation petrol  c thermal decomposition paraffin  d thermal decomposition petrol      39 the structures of three compounds are shown.    hhh hchh hh c cc cchhc h hhhhhhh hh c cchhc hhc     why do these substances all belong to the same homologous series?  a they all contain an even number of carbon atoms.  b they all contain the same functional group. c they are all hydrocarbons. d they are all saturated.      40 which bond is not in a molecule of ethanoic acid?  a c\u2013o b c=o c c=c d o\u2013h     ",
            "16": "15   0620/11/m/j/09  blank page",
            "17": "16    permission to reproduce items where third-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/11/m/j/09   group  140  ce  cerium  58 141  pr  praseodymium  59 144  nd  neodymium  60 pm  promethium  61 150  sm  samarium  62 152  eu  europium  63 157  gd  gadolinium  64 159  tb  t erbiu m  65 162  dy  dysprosium  66 165  ho  holmium  67 167  er  erbium  68 169  tm  thulium  69 173  yb  ytterbium  70 175  lu  lutetium  71  232  th  thorium  90 pa  protactinium  91 238  u  uranium  92 np  neptunium  93 pu  plutonium  94 am  americium  95 cm  curium  96 bk  berkelium  97 cf  californium  98 es  einsteinium  99 fm  fermium  100 md  mendelevium  101 no  nobelium  102 lr  lawrencium  103 1  h  hydrogen  1  7  li  lithium  3  23  na  sodium  1 1 24  mg  magnesium  12  40  ca  calcium  20 45  sc  scandium  21 48  t i  t itaniu m  22 51  v  v anadiu m  23 52  cr  chromium  24 55  mn  manganese  25 56  fe  iron  26 59  co  cobalt  27 59  ni  nickel  28 64  cu  copper  29 65  zn  zinc  30 70  ga gallium  31 27  a l  aluminium  13 1 1  b  boron  5 12  c  carbon  6 14  n  nitrogen  7 16  o  oxygen  8 19  f  fluorine  9  28  si  silicon  14 31  p  phosphorus  15 32  s  sulfur  16 35.5  c l  chlorine  17 40  ar  argon  18 20  ne  neon  10 4  he  helium  2  73  ge  germanium  32 75  as  arsenic  33 79  se  selenium  34 80  br  bromine  35 84  kr  krypton  36 39  k  potassium  19  88  sr  strontium  38 89  y  yttrium  39 91  zr  zirconium  40 93  nb  niobium  41 96  mo  molybdenum  42 t c  t echnetiu m  43 101  ru  ruthenium  44 103  rh  rhodium  45 106  pd  palladium  46 108  ag  silver  47 1 1 2  cd  cadmium  48 1 1 5  in indium  49 1 1 9  sn  t i n  50 122  sb  antimony  51 128  t e  t elluriu m  52 127  i iodine  53 131  xe  xenon  54  137  ba  barium  56 139  la  lanthanum  57         * 178  hf  hafnium  72 181  t a  t antalu m  73 184  w  t ungste n  74 186  re  rhenium  75 190  os  osmium  76 192  ir  iridium  77 195  pt  platinum  78 197  au  gold  79 201  hg  mercury  80 204  t l  thallium  81 207  pb  lead  82 209  bi  bismuth  83 po  polonium  84 at  astatine  85 rn  radon  86  fr  francium  87 227  ac  actinium  89 9  be  beryllium  4 i ii iii iv v vi vii 0  85  rb  rubidium  37  133  cs  caesium  55  226  ra  radium  88  the volume of one mole of an y gas is 2 4 dm 3 at room temperature and pressure ( r .t.p.) . a  x  b a = relative atomic mass  x  = atomic symbol  b = proton (atomic) number key * 58-71 lanthanoid series  90-103 actinoid series d a t a  shee t  the periodic  t able of the element s   ",
            "18": "    this document consists of 15 printed pages and 1 blank page.  ib09 06_0620_12/7rp  \u00a9 ucles 2009  [turn over      *6562648243* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1  multiple choice  may/june 2009     45 minutes    additional materials: multiple choice answer sheet    soft clean eraser    soft pencil (type b or hb is recommended)        read these instructions first    write in soft pencil.  do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided  unless this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.   read the instructions on the answer sheet very carefully.    each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.         ",
            "19": "2  \u00a9 ucles 2009 0620/12/m/j/09  1 the diagram shows how the molecules in the exhaust gases diffuse into the air.    molecules in air molecules in exhaust gases    which statement describes what happens to these molecules next?  a the molecules fall to the ground because they are heavier than air molecules.  b the molecules go back together as they cool.  c the molecules spread further into the air.  d the molecules stay where they are.     2 the diagram shows the paper chromatograms of four substances, w, x, y and z.    w x y z     which two substances are pure?  a w and x b w and y c x and y d x and z     ",
            "20": "3  \u00a9 ucles 2009 0620/12/m/j/09 [turn over  3 a student takes 2  g samples of calcium carbonate and adds them to 20  cm3 samples of dilute  hydrochloric acid at different temperatures. she measures how long it takes for the effervescence  to stop.    which apparatus does she use?     balance clock filter  funnel measuring  cylinder thermometer a \u0013 \u0013 \u0013 \u0013 \u0017  b \u0013 \u0013 \u0017 \u0013 \u0013  c \u0013 \u0017 \u0013 \u0013 \u0013  d \u0017 \u0013 \u0013 \u0017 \u0013    4 the diagrams show the structures of two forms, p and q, of a solid element.    pq     what are suitable uses of p and q, based on their structures?     use of solid p use of solid q  a drilling drilling  b drilling lubricating  c lubricating drilling  d lubricating lubricating     5 an element s has the proton number 18. the next element in the periodic table is an element t.    which statement is correct?  a element t has one more electron in its outer shell than element s.  b element t has one more electron shell than element s.  c element t is in the same group of the periodic table as element s.  d element t is in the same period of the periodic table as element s. ",
            "21": "4  \u00a9 ucles 2009 0620/12/m/j/09  6 element v forms an acidic, covalent oxide.    which row in the table shows how many electrons there could be in the outer shell of an atom of v?     1 2 6 7  a \u0013 \u0017 \u0017 \u0017  b \u0013 \u0013 \u0017 \u0017  c \u0017 \u0017 \u0017 \u0013  d \u0017 \u0017 \u0013 \u0013    7 which numbers are added together to give the nucleon number of an ion?  a number of electrons + number of neutrons   b number of  electrons + number of protons  c number of electrons + number of protons + number of neutrons  d number of protons + number of neutrons    8 when sodium chloride is formed from its elements, each chlorine atom \u2026\u20261\u2026\u2026 one \u2026\u20262\u2026\u2026.    which words correctly complete gaps 1 and 2?     1 2  a gains electron  b gains proton  c loses electron  d loses proton     9 the electronic configuration of an ion is 2.8.8.   what could this ion be?     s 2\u2013 ca2+  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "22": "5  \u00a9 ucles 2009 0620/12/m/j/09 [turn over  10 nitrogen and hydrogen react together to form ammonia.    n2 + 3h 2 \u2192 2nh 3    when completely converted, 7 tonnes of nitrogen gives 8.5 tonnes of ammonia.    how much nitrogen will be needed to produce 34 tonnes of ammonia?  a 7 tonnes b 8.5 tonnes c 28 tonnes d 34 tonnes     11 which relative molecular mass, m r, is not correct for the molecule given?     molecule mr  a ammonia, nh 3 17  b carbon dioxide, co 2 44  c methane, ch 4 16  d oxygen, o 2 16    12 which of these elements could be formed at the anode when a molten salt is electrolysed?    a copper  b iodine  c lithium  d strontium      13 aluminium is extracted from its oxide by electrolysis.    the oxide is dissolved in \u2026\u20261\u2026\u2026 cryolite and aluminium is deposited at the \u2026\u20262\u2026\u2026    which words correctly complete gaps 1 and 2?     1 2  a aqueous cathode  b aqueous anode  c molten cathode  d molten anode    ",
            "23": "6  \u00a9 ucles 2009 0620/12/m/j/09  14 molten lead( ii) bromide is electrolysed as shown.    a+\u2013 molten lead(ii) bromide     which ions are discharged at each electrode?     positive electrode negative electrode  a pb+ br2\u2013  b pb2+ br  \u2013  c br2\u2013 pb+  d br \u2013 pb2+     15 which diagram shows a process in which an endothermic change is taking place?    candlesodiumab c d ice rocket waterwater      ",
            "24": "7  \u00a9 ucles 2009 0620/12/m/j/09 [turn over  16 the diagram shows some properties that substances may have.    to which labelled part of the diagram does 235u belong?    compoundused as an energy source radioactivea bdc      17 the equation shows a reaction that is reversed by changing the conditions.    forward reaction  cuso 4.5h 2o \u2192 cuso 4 + 5h 2o    how can the forward reaction be reversed?     by adding water by heating  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      18 which does not increase the speed of a reaction?  a adding a catalyst  b increasing the concentration of one of the reactants  c increasing the particle size of one of the reactants  d increasing the temperature     ",
            "25": "8  \u00a9 ucles 2009 0620/12/m/j/09  19 the reactions shown may occur in the air during a thunder storm.    n2 + o 2 \u2192 2no  2no + o 2 \u2192 2no 2  no + o 3 \u2192 no 2 + o 2    which line shows what happens to the reactant molecules in each of these reactions?     n2 no o 3  a oxidised oxidised oxidised  b oxidised oxidised reduced  c reduced reduced oxidised  d reduced reduced reduced      20 some reactions of a substance, r, are shown in the diagram.    substance rmagnesium sodium carbonate copper( ii) oxidehydrogen carbon dioxide copper(ii) sulfatereacts with     what type of substance is r?  a an acid  b a base  c an element  d a salt     21 an element e is burned in air. a white solid oxide is formed.    the oxide is tested with damp red litmus paper. the paper turns blue.    what is element e?  a calcium  b carbon  c iodine  d sulfur     ",
            "26": "9  \u00a9 ucles 2009 0620/12/m/j/09 [turn over  22 the graph shows how the ph of soil in a field changed over time.    at which point was the soil neutral?    11 9 753ph of soil timea b cd       23 aqueous sodium hydroxide is added to a solution of a salt. a blue precipitate is formed which  does not dissolve in excess.    aluminium foil is added to the mixture and the mixture is warmed. a gas is produced that turns  damp red litmus paper blue.    what is the name of the salt?  a ammonium nitrate  b ammonium sulfate  c copper( ii) nitrate  d copper( ii) sulfate      24 which statement describes the trends going down group vii of the periodic table?  a the boiling point and melting point both decrease.  b the boiling point and melting point both increase.  c the boiling point decreases but the melting point increases.  d the boiling point increases but the melting point decreases.     ",
            "27": "10  \u00a9 ucles 2009 0620/12/m/j/09  25 the sulfate of element f is green.    which other properties is element f likely to have?     density melting point  a high high  b high low  c low high  d low low     26 which diagram represents the structure of an alloy?    abcd     27 an inert atmosphere is needed in a lamp to lengthen the useful life of the metal filament.    why is argon, rather than helium, used for this purpose?     argon is more abundant  in the air argon is less dense  than helium  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     28 in a blast furnace, iron( iii) oxide is converted to iron and carbon monoxide is converted to carbon  dioxide.    fe 2o3 + 3co \u2192 2fe + 3co 2    what happens to each of these reactants?  a both iron( iii) oxide and carbon monoxide are oxidised.  b both iron( iii) oxide and carbon monoxide are reduced.  c iron( iii) oxide is oxidised and carbon monoxide is reduced.  d iron( iii) oxide is reduced and carbon monoxide is oxidised. ",
            "28": "11  \u00a9 ucles 2009 0620/12/m/j/09 [turn over  29 which property do all metals have?  a they are hard.  b they conduct electricity.  c they form acidic oxides.  d they react with water.      30 stainless steel is an alloy of iron and other metals. it is strong and does not rust but it costs much  more than normal steel.    what is not  made from stainless steel?  a cutlery  b pipes in a chemical factory  c railway lines  d saucepans     31 the table gives information about three different metals g, h and j.    does it react with   metal  water steam key  g \u0017 \u0017 \u0013= does react  h \u0013 \u0013 \u0017= does not react  j \u0017 \u0013     what is the order of reactivity of these metals?     most  reactive  least  reactive  a g h j  b h g j  c h j g  d j h g     ",
            "29": "12  \u00a9 ucles 2009 0620/12/m/j/09  32 the diagram shows stages in the purification of water.    which stage uses chlorine?    water at ph9  + bacteria + large solids + fine solids water at ph9+ bacteria+ fine solidswater at ph9+ bacteria water at ph7+ bacteriapure waterat ph7a b  c  d        33 which statements are correct?    1 carbon monoxide is responsible for the production of \u2018acid rain\u2019.  2 oxides of nitrogen are present in car exhausts. 3 sulfur dioxide can be produced by the combustion of fossil fuels.    a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3      34 substance k reacts with sodium carbonate to form a gas.    the gas turns limewater cloudy.    what is substance k and which process takes place in the reaction?     k process  a ethanol combustion  b ethanol neutralisation  c hydrochloric acid combustion  d hydrochloric acid neutralisation    ",
            "30": "13  \u00a9 ucles 2009 0620/12/m/j/09 [turn over  35 an iron nail is placed in a closed test-tube, containing gas l.    the nail rusts.    gas l waternail     what is gas l?  a carbon dioxide  b hydrogen  c nitrogen  d oxygen      36 a compound has the formula ch 3ch 2ch=ch 2.    which row in the table shows the type of compound and the colour change when aqueous  bromine is added?     type of compound colour change  a saturated brown to colourless  b saturated colourless to brown  c unsaturated brown to colourless  d unsaturated colourless to brown     37 which element is not added to a fertiliser?  a aluminium  b nitrogen  c phosphorus  d potassium    ",
            "31": "14  \u00a9 ucles 2009 0620/12/m/j/09  38 the structures of three compounds are shown.    hhh hchh hh c cc cchhc h hhhhhhh hh c cchhc hhc     why do these substances all belong to the same homologous series?  a they all contain an even number of carbon atoms.  b they all contain the same functional group. c they are all hydrocarbons. d they are all saturated.      39 which bond is not in a molecule of ethanoic acid?  a c\u2013o b c=o c c=c d o\u2013h      40 the diagram shows an industrial process. subst ance m is one of the substances produced by  this process and is used as aircraft fuel.    substance m     what is this process and what is substance m?     process substance m  a fractional distillation paraffin  b fractional distillation petrol  c thermal decomposition paraffin  d thermal decomposition petrol     ",
            "32": "15   0620/12/m/j/09  blank page",
            "33": "16    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/12/m/j/09   group  140  ce  cerium  58 141  pr  praseodymium  59 144  nd  neodymium  60 pm  promethium  61 150  sm  samarium  62 152  eu  europium  63 157  gd  gadolinium  64 159  tb  t erbiu m  65 162  dy  dysprosium  66 165  ho  holmium  67 167  er  erbium  68 169  tm  thulium  69 173  yb  ytterbium  70 175  lu  lutetium  71  232  th  thorium  90 pa  protactinium  91 238  u  uranium  92 np  neptunium  93 pu  plutonium  94 am  americium  95 cm  curium  96 bk  berkelium  97 cf  californium  98 es  einsteinium  99 fm  fermium  100 md  mendelevium  101 no  nobelium  102 lr  lawrencium  103 1  h  hydrogen  1  7  li  lithium  3  23  na  sodium  1 1 24  mg  magnesium  12  40  ca  calcium  20 45  sc  scandium  21 48  t i  t itaniu m  22 51  v  v anadiu m  23 52  cr  chromium  24 55  mn  manganese  25 56  fe  iron  26 59  co  cobalt  27 59  ni  nickel  28 64  cu  copper  29 65  zn  zinc  30 70  ga gallium  31 27  a l  aluminium  13 1 1  b  boron  5 12  c  carbon  6 14  n  nitrogen  7 16  o  oxygen  8 19  f  fluorine  9  28  si  silicon  14 31  p  phosphorus  15 32  s  sulfur  16 35.5  c l  chlorine  17 40  ar  argon  18 20  ne  neon  10 4  he  helium  2  73  ge  germanium  32 75  as  arsenic  33 79  se  selenium  34 80  br  bromine  35 84  kr  krypton  36 39  k  potassium  19  88  sr  strontium  38 89  y  yttrium  39 91  zr  zirconium  40 93  nb  niobium  41 96  mo  molybdenum  42 t c  t echnetiu m  43 101  ru  ruthenium  44 103  rh  rhodium  45 106  pd  palladium  46 108  ag  silver  47 1 1 2  cd  cadmium  48 1 1 5  in indium  49 1 1 9  sn  t i n  50 122  sb  antimony  51 128  t e  t elluriu m  52 127  i iodine  53 131  xe  xenon  54  137  ba  barium  56 139  la  lanthanum  57         * 178  hf  hafnium  72 181  t a  t antalu m  73 184  w  t ungste n  74 186  re  rhenium  75 190  os  osmium  76 192  ir  iridium  77 195  pt  platinum  78 197  au  gold  79 201  hg  mercury  80 204  t l  thallium  81 207  pb  lead  82 209  bi  bismuth  83 po  polonium  84 at  astatine  85 rn  radon  86  fr  francium  87 227  ac  actinium  89 9  be  beryllium  4 i ii iii iv v vi vii 0  85  rb  rubidium  37  133  cs  caesium  55  226  ra  radium  88  the volume of one mole of an y gas is 2 4 dm 3 at room temperature and pressure ( r .t.p.) . a  x  b a = relative atomic mass  x  = atomic symbol  b = proton (atomic) number key * 58-71 lanthanoid series  90-103 actinoid series d a t a  shee t  the periodic  t able of the element s   "
        },
        "0620_s09_qp_2.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib09 06_0620_02/6rp  \u00a9 ucles 2009  [turn over       *7049085572* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/02     paper 2  may/june 2009     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name in the spaces at the top of this page.  write in dark blue or black pen. you may need to use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.    answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2009 0620/02/m/j/09  for  examiner's  use 1 (a) choose from the list of compounds to answer questions (i) to (v).    calcium carbonate carbon dioxide hydrogen chloride  iron(iii) oxide lead( ii) bromide methane sodium hydroxide      each compound can be used once, more than once or not at all.     name the compound which    (i) is a transition metal compound,   [1]       (ii) produces brown fumes at the anode when electrolysed,   [1]      (iii) is used to manufacture lime,   [1]      (iv) dissolves in water to form an alkaline solution,   [1]     (v) is the main constituent of natural gas.   [1]    ",
            "3": "3  \u00a9 ucles 2009 0620/02/m/j/09 [turn over  for  examiner's  use  (b) at a high temperature iron( iii) oxide is reduced by carbon.    fe2o3    +    3c        2fe    +    3co     (i) explain how the equation shows that iron( iii) oxide is reduced by carbon.   [1]       (ii) complete these sentences about the extraction of iron using words from the list.    bauxite blast  converter haematite lime      limestone sand   slag    iron is extracted from  by mixing the ore with   coke and  in a  furnace.   the iron ore is reduced to iron and impurities in the ore react with calcium oxide  to form   . [4]    [total: 10] ",
            "4": "4  \u00a9 ucles 2009 0620/02/m/j/09  for  examiner's  use 2 the table shows some observations about the reactivity of various metals with dilute  hydrochloric acid.    metal observations  calcium many bubbles produced rapidly with much spitting  copper no bubbles formed  iron a few bubbles produced very slowly  magnesium many bubbles produced rapidly with no spitting    (a) put these metals in order of their reactivity.      most reactive least reactive    [1]    (b) zinc is between iron and magnesium in its reactivity.    suggest what observations are made about how fast the bubbles are produced when  zinc reacts with dilute hydrochloric acid.   [1]     (c) magnesium is extracted by the electrolysis of molten magnesium chloride.    inert gas molten magnesium molten magnesium chlorideiron cathode (\u2013)anode (+)      (i) what information in the diagram suggests that magnesium is less dense than  molten magnesium chloride?   [1]     ",
            "5": "5  \u00a9 ucles 2009 0620/02/m/j/09 [turn over  for  examiner's  use  (ii) suggest why magnesium has to be extracted by electrolysis rather than by heating  its oxide with carbon.   [1]      (iii) suggest why a stream of inert gas is blown over the surface of the molten  magnesium.   [1]      (iv) state the name of a gaseous element which is inert.   [1]      (d) in some old magnesium manufacturing plants, coal gas is blown over the surface of the  magnesium.    the list shows the main substances in coal gas.    carbon monoxide ethene hydrogen  hydrogen sulfide       methane    (i) draw the structure of ethene showing all atoms and bonds.                 [1]       (ii) suggest two hazards of using coal gas by referring to two specific substances in  the list.  substance   hazard   substance   hazard  [2]     ",
            "6": "6  \u00a9 ucles 2009 0620/02/m/j/09  for  examiner's  use  (e) carbon monoxide can be removed from coal gas by mixing it with steam and passing  the mixture over a catalyst of iron( iii) oxide at 400  \u00bac.    co    +    h 2o        co 2    +    h 2       (i) write a word equation for this reaction.   [1]      (ii) what does the symbol   mean?   [1]      (iii) iron( iii) oxide reacts with acids to form a solution containing iron( iii) ions.     describe a test for aqueous iron( iii) ions.  test   result    [2]     [total: 13]    ",
            "7": "7  \u00a9 ucles 2009 0620/02/m/j/09 [turn over  for  examiner's  use 3 petroleum is a mixture of hydrocarbons which can be separated into fractions such as  petrol, paraffin and diesel.     (a) state the name of the process used to separate these fractions.   [1]       (b) name two other fractions which are obtained from petroleum .    and   [2]       (c) give one  use for the paraffin fraction.   [1]      (d) many of the compounds obtained from petroleum are alkanes.    which two of the following structures are alkanes?    cab hh h h cc hh oh h cd hh ch c h hhhhcch hhh    [1]       (e) use words from the list below to complete the following sentence.    ethane ethene hydrogen nitrogen oxygen    reactive  unreactive  water    alkanes such as   are generally   but they can  be burnt in   to form carbon dioxide and  [4]       (f) alkanes are saturated hydrocarbons.    what do you understand by the terms  (i) saturated,      (ii) hydrocarbon?     [2]    [total: 11] ",
            "8": "8  \u00a9 ucles 2009 0620/02/m/j/09  for  examiner's  use 4 this question is about some compounds of nitrogen.     a mixture of ammonium sulfate and sodium hydroxide was warmed in a test-tube.  the gas was tested with moist red litmus paper.   heat gentlyred litmus paper ammonium sulfate and sodium hydroxide      (a) state the name of the gas released.   [1]       (b) state the colour change of the litmus paper.   [1]      (c) complete the word equation for the reaction of ammonium carbonate with hydrochloric  acid.      ammonium       +       hydrochloric      \u2026\u2026\u2026...   +   \u2026\u2026\u2026...   +   \u2026\u2026\u2026..     carbonate                   acid                                                                                                                \u2026\u2026\u2026...       \u2026\u2026\u2026 [3]        (d) ammonium salts such as ammonium nitrate, nh 4no 3 and ammonium chloride nh 4cl  are used as fertilisers.     (i) explain why farmers need to use fertilisers.     [1]      (ii) explain why ammonium nitrate is a better fertiliser than ammonium chloride.   [1]    ",
            "9": "9  \u00a9 ucles 2009 0620/02/m/j/09 [turn over  for  examiner's  use  (iii)  calculate the relative formula mass of ammonium nitrate.            [1]       (e) when ammonium nitrate is heated nitrogen( i) oxide is given off.    nitrogen( i) oxide relights a glowing splint.     name one other gas which relights a glowing splint.   [1]       (f) state one harmful effect of nitrogen oxides on the environment.   [1]     [total: 10]        ",
            "10": "10  \u00a9 ucles 2009 0620/02/m/j/09  for  examiner's  use  100.4 100.3100.2100.1100.0mass of flask and contents  / grams 0 100 200 300 400 500 600 700 time  / seconds5 a student used the apparatus shown below to investigate the rate of reaction of calcium  carbonate with dilute hydrochloric acid.    caco 3    +    2hc l        cac l2    +    co 2    +    h 2o    cotton wool dilute hydrochloric acid calcium carbonate balance100.4        (a) use the information in the equation to sugge st why the mass of the flask and contents  decreases with time.     [1]       (b) the graph shows how the mass of the flask and its contents changes with time.                   ",
            "11": "11  \u00a9 ucles 2009 0620/02/m/j/09 [turn over  for  examiner's  use  (i) at what time was the reaction just complete?   [1]      (ii) on the graph, mark with an x the point where the speed (rate) of reaction was  fastest. [1]     (iii) the student repeated the experiment but altered the concentration of the  hydrochloric acid so that it was half the original value. in both experiments calcium  carbonate was in excess and all other conditions were kept the same.      on the graph on page 10, draw a curve to show how the mass of the flask and  contents changes with time when hydrochloric acid of half the concentration was  used.  [2]      (c) how does the speed (rate) of this reaction change when     (i)  the temperature is increased,   [1]    (ii)  smaller pieces of calcium carbonate are used?   [1]       (d) complete the following sentence using words from the list.    combustion expansion large rapid slow small    in flour mills there is often the risk of an explosion due to the rapid   of the very   particles which have a very   surface area to react. [3]       (e) cells in plants and animals break down glucose to carbon dioxide and water.    glucose    +    oxygen        carbon dioxide    +    water    (i) state the name of this process.   [1]      (ii) in this process enzymes act as catalysts.     what do you understand by the term catalyst?   [1]     [total: 12] ",
            "12": "12  \u00a9 ucles 2009 0620/02/m/j/09  for  examiner's  use 6 bromine is an element in group vii of the periodic table.     (a) write the formula for a molecule of bromine.   [1]       (b) complete the diagram below to show the arrangement of the molecules in liquid  bromine.      represents a bromine molecule         [2]       (c) a teacher placed a small amount of liquid bromine in the bottom of a sealed gas jar of air. after two minutes brown fumes were seen just above the liquid surface. after one hour the brown colour had spread completely throughout the gas jar.    start after 2 minutes afterliquid bromineair         use the kinetic particle theory to explain these observations.       [3]     ",
            "13": "13  \u00a9 ucles 2009 0620/02/m/j/09 [turn over  for  examiner's  use  (d) magnesium salts are colourless but group vii elements are coloured.    an aqueous solution of magnesium bromide reacts with an aqueous solution of  chlorine.    magnesium bromide   +   chlorine      magnesium chloride   +   bromine      state the colour change in this reaction.   [2]       (e) a solution of magnesium bromide will not react with iodine.    explain why there is no reaction.   [1]       (f) the structures of some compounds containing bromine are shown below.    na+ br \u2013  na+ br \u2013  na+ br \u2013  na+ br \u2013 na+ br \u2013  na+ br \u2013  na+ br \u2013  na+ br \u2013 zn2+br \u2013br \u2013 zn2+br \u2013br \u2013zn2+br \u2013br \u2013 zn2+br \u2013br \u2013a b c d  h br  br f f  f      (i) write the simplest formula for the substance with structure a.   [1]      (ii) state the name of the substance with structure d.   [1]     (iii) state the type of bonding within a molecule of structure c.   [1]     (iv) which two structures are giant structures?    and   [1]       (v) why does structure a conduct electricity when it is molten?   [1]    [total: 14] ",
            "14": "14  \u00a9 ucles 2009 0620/02/m/j/09  for  examiner's  use 7 hydrogen chloride can be made by burning hydrogen in chlorine.    (a) complete the equation for this reaction.    h 2    +    \u2026\u2026\u2026\u2026...        \u2026\u2026\u2026..    hc l   [2]       (b) draw a dot and cross diagram for a molecule of hydrogen chloride.    show all the electrons.      use o for an electron from a hydrogen atom    use x for an electron from a chlorine atom                 [2]       (c) hydrochloric acid is formed when hydrogen chloride gas dissolves in water.    suggest the ph of hydrochloric acid.    put a ring around the correct answer.   ph 1 ph7 ph9 ph 13    [1]    (d) complete the equation for the reaction of hydrochloric acid with zinc.  zinc    +    hydrochloric acid        zinc chloride    +    \u2026\u2026\u2026\u2026\u2026\u2026 [1]       (e) describe how dry crystals of zinc chloride can be obtained from a solution of zinc  chloride.       [2]       (f) a student electrolysed molten zinc chloride.    state the name of the product formed at  (i) the anode,  [1]   (ii) the cathode.  [1]    [total: 10] ",
            "15": "15   0620/02/m/j/09   blank page   ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2009 0620/02/m/j/09  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s09_qp_3.pdf": {
            "1": "location entry codes       as part of cie\u2019s continual commitment to main taining best practice in assessment, cie uses  different variants of some question papers for our most popular assessments with large and  widespread candidature. the question papers are closely related and the relationships between  them have been thoroughly established using our assessment expertise.  all versions of the  paper give assessment of equal standard.     the content assessed by the examination papers and the type of questions is unchanged.   this change means that for this component there are now two variant question papers, mark  schemes and principal examiner\u2019s reports where previously there was only one.  for any individual country, it is intended that only one variant is used.  this document contains both  variants which will give all centres access to even more past examination ma terial than is usually  the case.      the diagram shows the relationship between the question papers, mark schemes and principal examiners\u2019 reports that are available.     question paper   mark scheme  principal examiner\u2019s  report  introduction     introduction   introduction   first variant question paper    first variant mark scheme  first variant principal  examiner\u2019s report    second variant question  paper  second variant mark  scheme    second variant principal  examiner\u2019s report      who can i contact for further information on these changes?  please direct any questions about this to cie\u2019s customer services team at: international@cie.org.uk              the titles for the variant items should correspond with the table above, so that at the top of the  first page of the relevant part of the document and on the header, it has the words:    \u2022 first variant question paper / mark scheme / principal examiner\u2019s report     or     \u2022 second variant question paper / mark scheme / principal examiner\u2019s report      as appropriate.    ",
            "2": "    this document consists of 15 printed pages and 1 blank pages.  ib09 06_0620_31/5rp  \u00a9 ucles 2009  [turn over       *5310297 965* for examiner's use  1   2   3   4   5   6   7   8   9   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/31     paper 3 (extended)  may/june 2009     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  questions.   ",
            "3": "2  \u00a9 ucles 2009 0620/31/m/j/09  for  examiner's  use 1 some grass is crushed and mixed with the solvent, propanone. the colour pigments are  extracted to give a deep green solution.    (a) (i)  draw a labelled diagram to describe how you could show that there is more than  one coloured pigment in the green solution.                  [3]       (ii) given a pure sample of chlorophyll, how could you show that the green solution  from the grass contained chlorophyll?         [2]       (b) explain the role of chlorophyll in green plants.             [3]       [total: 8]     ",
            "4": "3  \u00a9 ucles 2009 0620/31/m/j/09 [turn over  for  examiner's  use 2 the results of experiments on electrolysis using inert electrodes are given in the table.      complete the table; the first line has been completed as an example.   electrolyte change at negative  electrode change at positive  electrode change to  electrolyte    molten lead( ii)  bromide     lead formed  bromine formed  used up            potassium formed  iodine formed  used up    dilute aqueous sodium chloride                     aqueous copper( ii)  sulfate                             hydrogen formed  bromine formed  potassium hydroxide formed     [total: 8]     ",
            "5": "4  \u00a9 ucles 2009 0620/31/m/j/09  for  examiner's  use 3 the following is a list of the electron distributions of atoms of unknown elements.    element electron distribution  a 2,5  b 2,8,4  c 2,8,8,2  d 2,8,18,8  e 2,8,18,8,1  f 2,8,18,18,7     (a) choose an element from the list for each of the following descriptions.  (i) it is a noble gas.    (ii) it is a soft metal with a low density.    (iii) it can form a covalent compound with element a.    (iv) it has a giant covalent structure similar to diamond.    (v) it can form a negative ion of the type x3-.  [5]     (b) elements c and f can form an ionic compound.    (i) draw a diagram that shows the formula of this compound, the charges on the ions and the arrangement of the valency electrons around the negative ion.     use o to represent an electron from an atom of c.     use x to represent an electron from an atom of f.               [3]     (ii) predict two properties of this compound.       [2]      [total: 10] ",
            "6": "5  \u00a9 ucles 2009 0620/31/m/j/09 [turn over  for  examiner's  use 4 the reactivity series of metals given below contains both familiar and unfamiliar elements.  for most of the unfamiliar elements, which are marked *, their common oxidation states are given.    * barium  ba  * lanthanum  la    (+3)   magnesium     zinc   * chromium cr  (+2), (+3), (+6)   iron     copper   * palladium (+2)       choose metal(s) from the above list to answer the following questions.   (i) which two metals would not react with dilute hydrochloric acid?   [2]    (ii) which two unfamiliar metals (*) would react with cold water?   [2]     (iii) what is the oxidation state of barium?   [1]     (iv) name an unfamiliar metal (*) whose oxide cannot be reduced by carbon.   [1]     (v) why should you be able to predict that metals such as iron and chromium have  more than one oxidation state?      [1]     [total: 7]    ",
            "7": "6  \u00a9 ucles 2009 0620/31/m/j/09  for  examiner's  use 5 insoluble salts are made by precipitation.     (a) a preparation of the insoluble salt calcium fluoride is described below.      to 15  cm3 of aqueous calcium chloride, 30  cm3 of aqueous sodium fluoride is added.  the concentration of both solutions is 1.00  mol  / dm3. the mixture is filtered and the  precipitate washed with distilled water. finally, the precipitate is heated in an oven.    (i) complete the equation.        ca 2+   +   ...\u2026\u2026.f-      \u2026\u2026\u2026..  [2]     (ii) why is the volume of sodium fluoride solution double that of the calcium chloride  solution?      [1]     (iii) why is the mixture washed with distilled water?      [1]     (iv) why is the solid heated?      [1]    ",
            "8": "7  \u00a9 ucles 2009 0620/31/m/j/09 [turn over  for  examiner's  use  16 12 840 02468 1 0 1 2 1 4 volume of phosphate solution  / cm3height of precipitate/  mm (b) the formulae of insoluble compounds can be found by precipitation reactions.      to 12.0  cm3 of an aqueous solution of the nitrate of metal t was added 2.0  cm3 of  aqueous sodium phosphate, na 3po 4. the concentration of both solutions was          1.00  mol  / dm3. when the precipitate had settled, its height was measured.    solution height of precipitateprecipitate of the phosphate of metal t       the experiment was repeated using different volumes of the phosphate solution. the  results are shown on the following graph.                           what is the formula of the phosphate of metal t? give your reasoning.         [3]       [total: 8]     ",
            "9": "8  \u00a9 ucles 2009 0620/31/m/j/09  for  examiner's  use 6 ammonia is manufactured by the haber process.    n2(g)   +    3h 2(g)        2nh 3(g)    the forward reaction is exothermic     (a) (i)  name the raw materials from which nitrogen and hydrogen are obtained.  nitrogen from  [1]  hydrogen from  [1]    (ii) name the catalyst used in this process.   [1]    (iii) what is the most important use of ammonia?   [1]      (b) the following graph shows how the percentage of ammonia in the equilibrium mixture  changes with temperature.    00% ammonia at equilibrium temperature     (i) explain the term equilibrium .         [2]     (ii) how does the percentage of ammonia vary with temperature?   [1]    ",
            "10": "9  \u00a9 ucles 2009 0620/31/m/j/09 [turn over  for  examiner's  use  (c) (i)  sketch a graph which shows how the percentage of ammonia in the equilibrium  mixture varies with pressure.    00% ammonia at equilibrium pressure     [1]     (ii) explain why the graph has the shape shown.       [2]      [total: 10]   ",
            "11": "10  \u00a9 ucles 2009 0620/31/m/j/09  for  examiner's  use 7 hydrogen reacts with the halogens to form hydrogen halides.       (a) bond energy is the amount of energy, in kj, that must be supplied (endothermic) to break one mole of a bond.    bond bond energy in kj  / mol  h\u2500h +436  cl\u2500cl +242  h\u2500c l +431     use the above data to show that the following reaction is exothermic.   h\u2500h    +    c l\u2500cl    /barb2right    2h\u2500cl           [3]     ",
            "12": "11  \u00a9 ucles 2009 0620/31/m/j/09 [turn over  for  examiner's  use  (b) they react with water to form acidic solutions.    hc l    +    h 2o        h 3o+    +    c l -    hf    +    h 2o        h 3o+    +    f  -     (i) explain why water behaves as a base in both of these reactions.     [2]     (ii) at equilibrium, only 1% of the hydrogen chloride exists as molecules, the rest has  formed ions. in the other equilibrium, 97% of the hydrogen fluoride exists as  molecules, only 3% has formed ions.      what does this tell you about the strength of each acid?     [2]     (iii) how would the ph of these two solutions differ?   [1]     [total: 8]   ",
            "13": "12  \u00a9 ucles 2009 0620/31/m/j/09  for  examiner's  use 8 lactic acid can be made from corn starch.    ch3ch cooh oh lactic acid     it polymerises to form the polymer, polylactic acid (pla ) which is biodegradable.     (a) suggest two advantages that pla has compared with a polymer made from petroleum.         [2]      (b) the structure of pla is given below.    ch3o ch occh3 oc h     (i) what type of compound contains the group that is circled?   [1]    (ii) complete the following sentence.  lactic acid molecules can form this group because they contain both an    group and an  group. [2]     (iii) is the formation of pla, an addition or condensation polymerisation? give a reason for your choice.       [2]     ",
            "14": "13  \u00a9 ucles 2009 0620/31/m/j/09 [turn over  for  examiner's  use  (c) when lactic acid is heated, acrylic acid is formed.    c c cooh ohh h hh lactic acid acrylic acidcch hh cooh      (i) complete the word equation for the action of heat on lactic acid.  lactic acid \u2192   +   [1]     (ii) describe a test that would distinguish between lactic acid and acrylic acid.  test   result for lactic acid   result for acrylic acid  [3]     (iii) describe a test, other than using an indicator, which would show that both chemicals contain an acid group.  test   result    [2]       [total: 13]    ",
            "15": "14  \u00a9 ucles 2009 0620/31/m/j/09  for  examiner's  use 9 quantities of chemicals, expressed in moles, can be used to find the formula of a  compound, to establish an equation and to determine reacting masses.    (a) a compound contains 72% magnesium and 28% nitrogen. what is its empirical formula?         [2]      (b) a compound contains only aluminium and carbon. 0.03  moles of this compound reacted  with excess water to form 0.12  moles of al(oh) 3 and 0.09  moles of ch 4.      write a balanced equation for this reaction.         [2]      (c) 0.07  moles of silicon reacts with 25  g of bromine.    si    +    2br 2        sibr 4    (i) which one is the limiting reagent? explain your choice.           [3]     (ii) how many moles of sibr 4 are formed?   [1]      [total: 8]   ",
            "16": "15   0620/31/m/j/09  blank page      ",
            "17": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.   \u00a9 ucles 2009 0620/31/m/j/09  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  ",
            "18": "    this document consists of 15 printed pages and 1 blank page.  ib09 06_0620_32/4rp  \u00a9 ucles 2009  [turn over       *0583100121* for examiner's use  1   2   3   4   5   6   7   8   9   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/32     paper 3 (extended)  may/june 2009     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  questions.   ",
            "19": "2  \u00a9 ucles 2009 0620/32/m/j/09  for  examiner's  use 1 some grass is crushed and mixed with the solvent, propanone. the colour pigments are  extracted to give a deep green solution.    (a) (i)  draw a labelled diagram to describe how you could show that there is more than  one coloured pigment in the green solution.                  [3]       (ii) given a pure sample of chlorophyll, how could you show that the green solution  from the grass contained chlorophyll?         [2]       (b) explain the role of chlorophyll in green plants.             [3]       [total: 8]     ",
            "20": "3  \u00a9 ucles 2009 0620/32/m/j/09 [turn over  for  examiner's  use 2 the results of experiments on electrolysis using inert electrodes are given in the table.      complete the table; the first line has been completed as an example.   electrolyte change at negative  electrode change at positive  electrode change to electrolyte    molten lead( ii)  bromide    lead formed  bromine formed  used up            lithium formed  chlorine formed  used up   dilute aqueous sodium chloride                    aqueous copper( ii)  sulfate                           hydrogen formed  bromine formed  potassium hydroxide  formed      [total: 8]    ",
            "21": "4  \u00a9 ucles 2009 0620/32/m/j/09  for  examiner's  use 3 the following is a list of the electron distributions of atoms of unknown elements.    element electron distribution  a 2,6  b 2,8,4  c 2,8,8,2  d 2,8,18,8  e 2,8,18,8,1  f 2,8,18,18,7     (a) choose an element from the list for each of the following descriptions.  (i) it is a noble gas.    (ii) it is a soft metal with a low density.    (iii) it can form a covalent compound with element a.    (iv) it has a giant covalent structure similar to diamond.    (v) it is a diatomic gas with molecules of the type x 2.  [5]     (b) elements c and a can form an ionic compound.    (i) draw a diagram that shows the formula of this compound, the charges on the ions and the arrangement of the valency electrons around the negative ion.     use o to represent an electron from an atom of c.     use x to represent an electron from an atom of a.                [3]    (ii) predict two properties of this compound.       [2]      [total: 10]   ",
            "22": "5  \u00a9 ucles 2009 0620/32/m/j/09 [turn over  for  examiner's  use 4 the reactivity series of metals given below contains both familiar and unfamiliar elements.  for most of the unfamiliar elements, which are marked *, their common oxidation states are given.    * barium  ba  * lanthanum  la    (+3)   magnesium     zinc   * chromium cr  (+2), (+3), (+6)   iron     copper   * palladium (+2)       choose metal(s) from the above list to answer the following questions.   (i) which two metals would not react with dilute hydrochloric acid?   [2]    (ii) which two unfamiliar metals (*) would react with cold water?   [2]     (iii) what is the oxidation state of barium?   [1]     (iv) name an unfamiliar metal (*) whose oxide cannot be reduced by carbon.   [1]     (v) why should you be able to predict that metals such as iron and chromium have  more than one oxidation state?      [1]     [total: 7]    ",
            "23": "6  \u00a9 ucles 2009 0620/32/m/j/09  for  examiner's  use 5 insoluble salts are made by precipitation.     (a) a preparation of the insoluble salt iron fluoride is described below.      to 15  cm3 of aqueous iron( iii) chloride, 45  cm3 of aqueous sodium fluoride is added.  the concentration of both solutions is 1.00  mol  / dm3. the mixture is filtered and the  precipitate washed with distilled water. finally, the precipitate is heated in an oven.     (i) complete the equation.        fe3+   +   ...\u2026\u2026.f-      \u2026\u2026\u2026..  [2]     (ii) why is the volume of sodium fluoride solution three times that of the iron( iii)  chloride solution?      [1]     (iii) why is the mixture washed with distilled water?      [1]     (iv) why is the solid heated?      [1]     ",
            "24": "7  \u00a9 ucles 2009 0620/32/m/j/09 [turn over  for  examiner's  use  16 12 840 02468 1 0 1 2 1 4 volume of phosphate solution  / cm3height of precipitate/  mm (b) the formulae of insoluble compounds can be found by precipitation reactions.      to 18.0  cm3 of an aqueous solution of the nitrate of metal t was added 2.0  cm3 of  aqueous sodium phosphate, na 3po 4. the concentration of both solutions was          1.00  mol  / dm3. when the precipitate had settled, its height was measured.    solution height of precipitateprecipitate of the phosphate of metal t       the experiment was repeated using different volumes of the phosphate solution. the  results are shown on the following graph.                            what is the formula of the phosphate of metal t? give your reasoning.         [3]       [total: 8]      ",
            "25": "8  \u00a9 ucles 2009 0620/32/m/j/09  for  examiner's  use 6 ammonia is manufactured by the haber process.    n2(g)   +    3h 2(g)        2nh 3(g)    the forward reaction is exothermic     (a) (i)  name the raw materials from which nitrogen and hydrogen are obtained.  nitrogen from  [1]  hydrogen from  [1]    (ii) name the catalyst used in this process.   [1]    (iii) what is the most important use of ammonia?   [1]     (b) the following graph shows how the percentage of ammonia in the equilibrium mixture changes with pressure.    00% ammonia at equilibrium pressure     (i) explain the term equilibrium .         [2]     (ii) how does the percentage of ammonia vary with pressure?   [1]     ",
            "26": "9  \u00a9 ucles 2009 0620/32/m/j/09 [turn over  for  examiner's  use  (c) (i)  sketch a graph which shows how the percentage of ammonia in the equilibrium  mixture varies with temperature.  00% ammonia at equilibrium temperature     [1]     (ii) explain why the graph has the shape shown.       [2]      [total: 10]       ",
            "27": "10  \u00a9 ucles 2009 0620/32/m/j/09  for  examiner's  use 7 hydrogen reacts with the halogens to form hydrogen halides.       (a) bond energy is the amount of energy, in kj, that must be supplied (endothermic) to  break one mole of a bond.    bond bond energy in kj  / mol  h\u2500h +436  f\u2500f +158  h\u2500f +562      use the above data to show that the following reaction is exothermic.    h\u2500h    +    f\u2500f    /barb2right    2h\u2500f             [3]     ",
            "28": "11  \u00a9 ucles 2009 0620/32/m/j/09 [turn over  for  examiner's  use  (b) they react with water to form acidic solutions.    hc l    +    h 2o        h 3o+    +    cl  -    hf    +    h 2o        h 3o+    +    f  -     (i) explain why water behaves as a base in both of these reactions.     [2]     (ii) at equilibrium, only 1% of the hydrogen chloride exists as molecules, the rest has formed ions. in the other equilibrium, 97% of the hydrogen fluoride exists as molecules, only 3% has formed ions.      what does this tell you about the strength of each acid?     [2]     (iii) how would the ph of these two solutions differ?   [1]      [total: 8]    ",
            "29": "12  \u00a9 ucles 2009 0620/32/m/j/09  for  examiner's  use 8 lactic acid can be made from corn starch.    ch3ch cooh oh lactic acid     it polymerises to form the polymer, polylactic acid (pla ) which is biodegradable.     (a) suggest two advantages that pla has compared with a polymer made from petroleum.         [2]      (b) the structure of pla is given below.    ch3o ch occh3 oc h     (i) what type of compound contains the group that is circled?   [1]    (ii) complete the following sentence.  lactic acid molecules can form this group because they contain both an    group and an  group. [2]     (iii) is the formation of pla, an addition or condensation polymerisation? give a reason for your choice.       [2]     ",
            "30": "13  \u00a9 ucles 2009 0620/32/m/j/09 [turn over  for  examiner's  use  (c) when lactic acid is heated, acrylic acid is formed.    c c cooh ohh h hh lactic acid acrylic acidcch hh cooh      (i) complete the word equation for the action of heat on lactic acid.  lactic acid \u2192   +   [1]     (ii) describe a test that would distinguish between lactic acid and acrylic acid.  test   result for lactic acid   result for acrylic acid  [3]    (iii) describe a test, other than using an indicator, which would show that both chemicals contain an acid group.  test   result    [2]       [total: 13]    ",
            "31": "14  \u00a9 ucles 2009 0620/32/m/j/09  for  examiner's  use 9 quantities of chemicals, expressed in moles, can be used to find the formula of a  compound, to establish an equation and to determine reacting masses.    (a) a compound contains 72% magnesium and 28% nitrogen. what is its empirical formula?         [2]      (b) a compound contains only aluminium and carbon. 0.03  moles of this compound reacted  with excess water to form 0.12  moles of al(oh) 3 and 0.09  moles of ch 4.      write a balanced equation for this reaction.         [2]      (c) 0.08  moles of silicon reacts with 7.2  g of fluorine.    si    +    2f 2        sif 4    (i) which one is the limiting reagent? explain your choice.           [3]     (ii) how many moles of sif 4 are formed?   [1]     [total: 8]   ",
            "32": "15   0620/32/m/j/09        blank page        ",
            "33": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2009 0620/32/m/j/09  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s09_qp_5.pdf": {
            "1": "    this document consists of 8 printed pages and 1 insert.  ib09 06_0620_05/5rp  \u00a9 ucles 2009  [turn over       *8948770840* for examiner's use  1   2   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/05     paper 5 practical test  may/june 2009     1 hour 15 minutes    candidates answer on the question paper .    additional materials: as listed in the confidential instructions   an insert is provided with the question paper      read these instructions first    write your name, centre number and candidate number on all the work you hand in.  write in dark blue or black pen.  you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid.  answer all questions. practical notes are provided on page 8. you have been provided with a separate insert to be used with question 1.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part question.   ",
            "2": "2  \u00a9 ucles 2009 0620/05/m/j/09  for  examiner's  use 1 you are going to investigate the effect of temperature on the speed of reaction between  hydrochloric acid and aqueous sodium thiosulfate. when these chemicals react they form a  precipitate, which makes the solution go cloudy. the formation of this precipitate can be used to show how fast the reaction proceeds.     read all the instructions below carefully before starting the experiments.    aqueous sodium thiosulfateeye 10  cm3 of hydrochloric acid conical flask printed insert sheet   you are going to carry out five experiments.   experiment 1   using the large measuring cylinder pour 50  cm3 of aqueous sodium thiosulfate into the conical  flask. measure the temperature of the solution and record it in the table. place the conical flask  on the printed insert provided. place 10  cm3 of the hydrochloric acid provided into the small measuring cylinder. add the acid to  the liquid in the flask and immediately start your timer and shake the flask. record in the table of results the time taken for the printed words to disappear from view. measure and record the final temperature of the liquid.  wash out the flask thoroughly  with water and rinse with distilled water.    experiment 2   pour 50  cm3 of aqueous sodium thiosulfate into the conical flask. heat the solution gently until  the temperature is about 30  \u00b0c. remove the flask from the heat, measure the temperature of the  solution and record it in the table.   place 10  cm3 of hydrochloric acid into the small measuring cylinder and repeat experiment 1.  measure and record the final temperature of the liquid. wash out the flask thoroughly  with water and rinse with distilled water.   experiment 3    repeat experiment 2, this time heating the sodium thiosulfate solution to about 40  \u00b0c before  adding the hydrochloric acid. measure the temperatures and record them in the table.     ",
            "3": "3  \u00a9 ucles 2009 0620/05/m/j/09 [turn over  for  examiner's  useexperiment 4    repeat experiment 2, this time heating the sodium thiosulfate solution to about 50  \u00b0c before  adding the hydrochloric acid.  measure and record the temperatures in the table.   experiment 5    repeat experiment 2, this time heating the sodium thiosulfate solution to about 60  \u00b0c before  adding the hydrochloric acid.  measure and record the temperatures in the table.   complete the table of results.   table of results   experiment  number   initial  temperature  of solution  / \u00b0cfinal  temperature  of solution  / \u00b0c average  temperature  / \u00b0c  time for  printed words  to disappear  / s  1      2      3      4      5        [5]",
            "4": "4  \u00a9 ucles 2009 0620/05/m/j/09  for  examiner's  use  (a) plot the results you have obtained on the grid and draw a smooth line graph.     180 160140120100 80604020 0 0 1 02 03 04 05 06 07 0 average temperature  / \u00b0ctime  / s       [3]   ",
            "5": "5  \u00a9 ucles 2009 0620/05/m/j/09 [turn over  for  examiner's  use (b) describe the appearance of the solution in the conical flask at the end of each  experiment.   [1]    (c) (i) in which experiment was the speed of reaction greatest?     [1]      (ii) explain why the speed was greatest in this experiment.         [3]        (d) why is the same volume of sodium thiosulfate and the same volume of hydrochloric acid used in each experiment?     [1]      (e) (i) from your graph deduce the time for the printed words to disappear if experiment  2 was repeated at 70  \u00b0c.     show clearly on the grid how you worked out your answer.   [3]      (ii) sketch on the grid the curve you would expect if all the experiments were repeated  using 50 cm3 of more concentrated sodium thiosulfate solution. [1]      (f) explain one change that could be made to the experimental method  to obtain more  accurate results.    change   explanation  [2]         [total:20]   ",
            "6": "6  \u00a9 ucles 2009 0620/05/m/j/09  for  examiner's  use 2 you are provided with two solids, solid s and solid v.   carry out the following tests on s and v.   record all your observations in the table.   do not write any conclusions in the table.    tests observations       tests on solid s    (a) describe the appearance of solid  s.      [2]    (b) place half of solid s in a  test-tube. add about 2 cm 3 of  hydrogen peroxide and shake the  tube. after 1 minute insert a  glowing splint into the tube.             colour of solution  [1]            [2]      [1]   [2]      [2]      [2]   (c) add the rest of solid s to about 5cm 3 of dilute sulfuric acid in a  boiling tube. heat the solution  carefully  to boiling point. place the  tube and contents in a test-tube  rack. leave to stand for 1 minute.   decant off the liquid into another  test-tube and add an equal  volume of distilled water to the  tube. using clean test-tubes, divide the solution into 3 equal portions.       (i) add several drops of aqueous  sodium hydroxide to the first  portion of the solution and shake the tube.   now add excess sodium  hydroxide to the tube.        heat the contents of the tube  gently.       (ii) to the second portion of the  solution add 1 cm3 of aqueous  ammonia solution.  now add excess ammonia  solution to the tube.         (iii) to the third portion of solution  add about 1  cm3 of dilute  hydrochloric acid followed by  about 1  cm3 of barium chloride  solution.    ",
            "7": "7    copyright acknowledgements:    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2009 0620/05/m/j/09 for  examiner's  usetests observations     [1] tests on solid v    (d) describe the appearance of solid  v.      [2]     (e) place half of solid v in a   test-tube. add about 2cm3 of  hydrogen peroxide to the   test-tube. test the gas with a glowing splint.    (f) (i) compare the reaction of solid s and solid v with hydrogen peroxide.   [1]      (ii) identify the gas given off in test (e).   [1]      (g) what conclusions can you draw about solid s?       [2]       (h) what conclusions can you draw about solid v?     [1]     [total: 20]",
            "8": "8  \u00a9 ucles 2009 0620/05/m/j/09  notes for use in qualitative analysis     test for anions     anion test test result  carbonate (co 32\u2013) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then add aqueous lead( ii) nitrate yellow ppt.  nitrate (no 3\u2013)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulfate (so 42\u2013)  [in solution] acidify with dilute nitric acid, then aqueous barium nitrate white ppt.    test for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh 4+) ammonia produced on warming -  calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt.  copper(cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution    test for gases     gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_s09_qp_6.pdf": {
            "1": "    this document consists of 12 printed pages and 4 blank pages.  ib09 06_0620_06/4rp  \u00a9 ucles 2009  [turn over       *7022409479* for examiner's use  1   2   3   4   5   6   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/06     paper 6 alternative to practical  may/june 2009     1 hour    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part question.   ",
            "2": "2   0620/06/m/j/09   blank page",
            "3": "3  \u00a9 ucles 2009 0620/06/m/j/09 [turn over  for  examiner's  use 1 a student reacted nitric acid with magnesium oxide to prepare magnesium nitrate. the  diagram shows the procedure followed in three stages.    warm  1 magnesium oxide weighed2  magnesium oxide  added until all the  nitric acid reacted 3  mixture allowed  to cool          (a) complete the boxes to identify the pieces of apparatus labelled. [3]      (b) (i)  what term is used to describe the unreacted magnesium oxide?   [1]       (ii) what method is used to remove the unreacted magnesium oxide after stage 3?   [1]      (c) describe how crystals of magnesium nitrate could be quickly obtained from the  solution.     [2]     [total: 7]   ",
            "4": "4  \u00a9 ucles 2009 0620/06/m/j/09  for  examiner's  use 2 an experiment was carried out to measure the temperature changes during the  neutralisation of sodium hydroxide solution with dilute hydrochloric acid. both solutions were allowed to stand in the laboratory for about 30 minutes.     25  cm3 of sodium hydroxide solution was added to a polystyrene beaker and the  temperature was measured. 10  cm3 of hydrochloric acid was added to the beaker and the  highest temperature reached measured.     the experiment was repeated using different volumes of acid.     (a) why were the solutions left to stand for about 30 minutes before the experiments?   [1]     (b) why was a polystyrene beaker used instead of a glass beaker?   [1]     the results of the experiments are shown plotted on the grid below.  0 1 02 03 04 05 06 040 30 20 10 0 volume of hydrochloric acid  / cm3 addedhighest temperaturereached  / \u00b0c  ",
            "5": "5  \u00a9 ucles 2009 0620/06/m/j/09 [turn over  for  examiner's  use  (c) what type of chemical reaction occurs when sodium hydroxide is neutralised by  hydrochloric acid?   [1]      (d) (i)  which point appears to be inaccurate?   [1]     (ii) draw two straight lines through the points and extend them until they cross. [2]     (iii) what volume of hydrochloric acid was needed to neutralise 25  cm3 of the sodium  hydroxide solution?   [2]     [total: 8]   ",
            "6": "6  \u00a9 ucles 2009 0620/06/m/j/09  for  examiner's  use 3 describe a chemical test to distinguish between each of the following pairs of substances.  an example is given.    example: hydrogen and carbon dioxide  test lighted splint  result with hydrogen   gives a pop    result with carbon dioxide   splint is extinguished       (a) zinc carbonate and zinc chloride  test   result with zinc carbonate   result with zinc chloride  [2]       (b) ammonia and chlorine  test   result with ammonia   result with chlorine  [3]       (c) aqueous iron( ii) sulfate and aqueous iron( iii) sulfate  test   result with aqueous iron( ii) sulfate   result with aqueous iron( iii) sulfate  [3]     [total: 8]   ",
            "7": "7  \u00a9 ucles 2009 0620/06/m/j/09 [turn over  for  examiner's  use 4 a student investigated the effect of temperature on the speed of reaction between  hydrochloric acid and aqueous sodium thiosulfate. when these chemicals react they form a precipitate, which makes the solution go cloudy. the formation of this precipitate can be used to show how fast the reaction pr oceeds, using the set up shown below.    aqueous sodium thiosulfateeye 10  cm3 of hydrochloric acid conical flask printed sheet printed text    five experiments were carried out.    experiment 1     by using a measuring cylinder 50  cm3 of aqueous sodium thiosulfate was poured into a  flask. the temperature of the solution was measured. the conical flask was placed on the printed text.   10  cm3 of hydrochloric acid was added to the flask and the timer started. the time taken for  the printed text to disappear from view was recorded in the table. the final temperature of the mixture was measured.      experiment 2     50  cm3 of aqueous sodium thiosulfate was poured into a conical flask. the solution was  heated until the temperature was about 30  \u00bac. the temperature of the solution was  measured.    10  cm3 of hydrochloric acid was added to the flask and experiment 1  was repeated.   the final temperature of the liquid was measured.   experiment 3    experiment 2 was repeated but the sodium thiosulfate solution was heated to about 40  \u00bac  before adding the hydrochloric acid.   the initial and final temperatures were measured.     experiment 4   experiment 2  was repeated but the sodium thiosulfate solution was heated to about 50  \u00bac  before adding the hydrochloric acid.   the initial and final temperatures were measured.  ",
            "8": "8  \u00a9 ucles 2009 0620/06/m/j/09  for  examiner's  use  experiment 5     experiment 2  was repeated but the sodium thiosulfate solution was heated to about 60  \u00bac  before adding the hydrochloric acid.   the initial and final  temperatures were measured.     use the thermometer diagrams to record all of the initial and final  temperatures in the table.   (a) complete the table of results to show the average temperatures.    table of results    experiment 1 2345130 79553326thermometer diagraminitial temperature /  \u00b0cthermometer diagramfinal temperature / \u00b0caverage temperature / \u00b0ctime for printed text to disappear / s 30 25 20 40 35 30 45 40 35 55 50 45 60 55 5030 25 20 40 35 30 45 40 35 55 50 45 60 55 50     [5]   ",
            "9": "9  \u00a9 ucles 2009 0620/06/m/j/09 [turn over  for  examiner's  use  (b) plot the results obtained on the grid and draw a smooth line graph.  140  120 100  80 60 40 20  0  0 10 20 30 40 50 60 70 time for printed text todisappear/  s average temperature  / \u00b0c      [4]     (c) (i)  in which experiment was the speed of reaction greatest?   [1]     (ii) explain why the speed was greatest in this experiment.       [3]  ",
            "10": "10  \u00a9 ucles 2009 0620/06/m/j/09  for  examiner's  use (d) why was the same volume of sodium thiosulfate solution and the same volume of  hydrochloric acid used in each experiment?     [1]      (e) (i)  from your graph, deduce the time fo r the printed text to disappear if experiment 2  was to be repeated at 70  \u00bac.       show clearly on the grid how you worked out your answer.   [3]      (ii) sketch on the grid the curve you would expect if all the experiments were repeated  using 50  cm3 of more concentrated sodium thiosulfate solution. [1]    (f) explain one change that could be made to the experimental method  to obtain more  accurate results.  change    explanation   [2]     [total: 20]   ",
            "11": "11   0620/06/m/j/09 [turn over     blank page                                              question 5 starts on page 12",
            "12": "12  \u00a9 ucles 2009 0620/06/m/j/09  for  examiner's  use 5 two solids, s and v, were analysed. s was copper( ii) oxide.   the tests on the solids, and some of the observations are in the following table.   complete the observations in the table. do not write any conclusions in the table.   test observation  tests on solid s       (a) appearance of solid s    black solid    (b) hydrogen peroxide was added to solid s in a test-tube.      slow effervescence      a glowing splint was inserted into the  tube.      splint relit     (c) dilute sulfuric acid was added to solid  s in a test-tube. the mixture was heated to boiling point.       blue solution formed      the solution was divided into three  equal portions into test-tubes.        (i) to the first portion of the solution,  excess sodium hydroxide was  added.        [1]    (ii) to the second portion of the  solution, about 1   cm3 of aqueous  ammonia solution was added.         [2]         excess ammonia solution was then  added.       [2]      (iii)   to the third portion of the solution,  dilute hydrochloric acid was added followed by barium chloride solution.           [2]       ",
            "13": "13  \u00a9 ucles 2009 0620/06/m/j/09 [turn over  for  examiner's  use test observation  tests on solid v       (d) appearance of solid v    black solid    (e) hydrogen peroxide was added to solid  v in a test-tube.     rapid effervescence      a glowing splint was inserted into the  tube.      splint relit         (f) (i)  compare the reactivity of solid s and solid v with hydrogen peroxide.   [1]    (ii) identify the gas given off in test (e).   [1]      (g) what conclusions can you draw about solid v?       [2]     [total: 11]     ",
            "14": "14  \u00a9 ucles 2009 0620/06/m/j/09  for  examiner's  use 6 acid base indicators     indicators are used to identify acids and bases.  indicators can be obtained from berries and other fruits.    (a) plan an experiment to obtain an aqueous solution of an indicator from some berries.               [3]       (b) plan an experiment to  use the indicator solution to show that it is an effective indicator.               [3]     [total: 6] ",
            "15": "15   0620/06/m/j/09   blank page ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2009 0620/06/m/j/09   blank page  "
        },
        "0620_w09_qp_11.pdf": {
            "1": "    this document consists of 16 printed pages.  ib09 11_0620_01/4rp  \u00a9 ucles 2009  [turn over      *2348620235* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  october/november 2009       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2009 0620/01/o/n/09  1 aqueous lead( ii) nitrate and aqueous potassium iodide are added to a dish containing water, as  shown.    aqueous lead( ii) nitrate aqueous potassium iodideyellow precipitate     a yellow precipitate forms after a few minutes.    which process occurs before the precipitate forms?  a diffusion   b distillation  c fermentation  d filtration      2 a student carries out an experiment to prepare pure magnesium sulfate crystals.    the diagram shows the first stage of the preparation.    dilute sulfuric acidstirrer magnesium carbonate     he adds magnesium carbonate until no more reacts.    which process should he use for the next stage?  a crystallisation  b evaporation  c filtration  d neutralisation     ",
            "3": "3  \u00a9 ucles 2009 0620/01/o/n/09 [turn over  3 a student separates salt from a mixture of salt and sand.    what is the correct order of steps for the student to take?  a filter \u2192 evaporate \u2192 shake with water  b filter \u2192 shake with water \u2192 evaporate  c shake with water \u2192 evaporate \u2192 filter  d shake with water \u2192 filter \u2192 evaporate      4 atom x has 8 more electrons than atom y.    student 1 says they are in the same group.    student 2 says they are unreactive.    which students can be correct?     student 1 student 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     5 which number is different for isotopes of the same element?  a number of electrons  b number of full shells  c number of nucleons  d number of protons     6 which atom has two more electrons than an atom of a noble gas?  a aluminium  b bromine c calcium d rubidium     ",
            "4": "4  \u00a9 ucles 2009 0620/01/o/n/09  7 statements 1, 2 and 3 are about diamond and graphite.    1 they are different solid forms of the same element.  2 they each conduct electricity. 3 they have atoms that form four equally strong bonds.     which statements are correct?  a 1 only b 3 only c 1 and 3 d 2 and 3      8 covalent bonds are formed when electrons are \u2026\u20261\u2026\u2026 . covalent compounds have \u2026\u20262\u2026\u2026 electrical conductivity.    which words correctly complete gaps 1 and 2?     1 2  a shared high  b shared low  c transferred high  d transferred low    9 which change to an atom occurs when it forms a positive ion?  a it gains electrons.  b it gains protons.  c it loses electrons.  d it loses protons.     10 for each atom of carbon present in a molecule, there is an equal number of atoms of oxygen but  twice as many atoms of hydrogen.    what is the formula of the molecule?  a c 2h2o2 b c 2h2o4 c c 2h4o2 d c 2h6o      11 water is formed when 48  g of oxygen combine with 6  g of hydrogen.    what mass of oxygen combines with 2  g of hydrogen?  a 12  g b 16  g c 96  g d 144  g    ",
            "5": "5  \u00a9 ucles 2009 0620/01/o/n/09 [turn over  12 the diagram shows how aluminium is manufactured by electrolysis.    cathode (\u2013ve) molten aluminiumaluminium  oxide  dissolved in  cryolite anode (+ve)     what are the anode and cathode made of?     anode cathode  a aluminium aluminium  b aluminium graphite  c graphite aluminium  d graphite graphite      13 the diagram shows the electrolysis of concentrated aqueous sodium chloride.    +\u2013positive electrodenegative electrode concentrated aqueous sodiumchloride anduniversal indicato rcarbon rods     what is the colour of the universal indicator at each electrode after five minutes?     colour at anode  (+ electrode) colour at cathode  (\u2013 electrode)  a blue/purple red  b red blue/purple  c red colourless  d colourless blue/purple ",
            "6": "6  \u00a9 ucles 2009 0620/01/o/n/09  14 the diagram shows an electrical cable.    metal coreplastic coating     which statement about the substances used is correct?  a the coating is plastic because it conducts electricity well.  b the core is copper because it conducts electricity well.  c the core is copper because it is cheap and strong.  d the core is iron because it is cheap and strong.      15 substance x requires oxygen in order to produce energy.    it does not  form carbon dioxide as a result of this energy production.    what is substance x?  a hydrogen  b natural gas  c petrol  d 235u      16 when an acid is added to an alkali the temperature rises.    which words describe this reaction?  a decomposition and endothermic  b decomposition and exothermic  c neutralisation and endothermic  d neutralisation and exothermic     ",
            "7": "7  \u00a9 ucles 2009 0620/01/o/n/09 [turn over  17 when blue copper( ii) sulfate is heated, a white solid and water are formed.    the white solid turns blue and gives out heat when water is added to it.    which terms describe the blue copper( ii) sulfate and the reactions?     the blue  copper( ii) sulfate is reaction  a a mixture can be reversed  b a mixture cannot be reversed  c hydrated can be reversed  d hydrated cannot be reversed     18 the equations represent redox reactions.     in which equation is the underlined substance acting as a reducing agent?  a cao  + h 2o \u2192 ca(oh) 2  b co 2 + c \u2192 2co  c cuo + h 2 \u2192 cu + h 2o  d 3co + fe 2o3 \u2192 2fe + 3co 2      19 which change does not increase the speed of reaction between zinc and hydrochloric  acid?  a adding a catalyst  b decreasing the temperature  c decreasing the particle size of the zinc  d using more concentrated acid     ",
            "8": "8  \u00a9 ucles 2009 0620/01/o/n/09  20 an aqueous solution y contains both barium ions and silver ions.    in separate experiments, dilute sulfuric acid and dilute hydrochloric acid are added to solution y.    which of these acids causes a precipitate to form in solution y?     dilute  sulfuric acid dilute  hydrochloric acid  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     21 the diagram shows the ph values of four solutions.    1 2 3 4 5 6 7 8 9 10 11 12 13 14     \u2191   \u2191  \u2191    \u2191    p q r s    which of these solutions are alkaline?  a p only  b p and q only  c q, r and s only  d r and s only    ",
            "9": "9  \u00a9 ucles 2009 0620/01/o/n/09 [turn over  22 the diagram shows the position of an element x in the periodic table.    x    what is the correct classification of element x and its oxide?     x oxide of x  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic     23 salts can be prepared by reacting a dilute acid    1 with a metal;  2 with a base;  3 with a carbonate.    which methods could be used to prepare copper( ii) chloride?  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3     ",
            "10": "10  \u00a9 ucles 2009 0620/01/o/n/09  24 astatine is an element in group vii of the periodic table. it has only ever been produced in very  small amounts.    what is the best description of its likely properties?     colour state reaction with aqueous  potassium iodide  a black solid no reaction  b dark brown gas brown colour  c green solid no reaction  d yellow liquid brown colour      25 elements in group 0 of the periodic table have uses.    these noble gases are \u2026\u20261.\u2026.. and this explains why argon \u2026\u20262\u2026\u2026 be used in lamps.    which words correctly complete gaps 1 and 2?     1 2  a reactive can  b reactive cannot  c unreactive can  d unreactive cannot     26 the table gives information about four elements.    which element is a transition metal?     colour  of element electrical conductivity  of element colour  of oxide  a black high colourless  b colourless low white  c grey high red  d yellow low colourless    27 which statement about alloys is not correct?  a alloys are more expensive than the metals they are made from.  b alloys are mixtures of different metals.  c alloys are not as strong as the metals they are made from.  d alloys conduct electricity well. ",
            "11": "11  \u00a9 ucles 2009 0620/01/o/n/09 [turn over  28 compound x is heated with carbon using the apparatus shown.    heatcompound x and carbon limewaterreaction tube     a brown solid is formed in the reaction tube and the limewater turns cloudy.    what is compound x?  a calcium oxide  b copper( ii) oxide  c magnesium oxide  d sodium oxide     29 some reactions of three metals are listed in the table.    metal reacts with dilute  hydrochloric acid metal oxide is  reduced by carbon  p yes yes  q no yes  r yes no    what is the order of reactivity of the metals?     most  reactive  least  reactive  a p r q  b r p q  c r q p  d q p r    ",
            "12": "12  \u00a9 ucles 2009 0620/01/o/n/09  30 which property do all metals have?  a they are soluble in water.  b they conduct electricity.  c they have high melting points.  d they react with dilute sulfuric acid.      31 which object is least  likely to contain aluminium?  a a bicycle frame  b a hammer  c a saucepan  d an aeroplane body      32 a newspaper article claims that carbon dioxide is formed as follows.    1 during respiration  2 when calcium carbonate reacts with hydrochloric acid  3 when methane burns in air    which statements are correct?  a 1, 2 and 3  b 1 and 2 only  c 1 and 3 only  d 2 and 3 only     33 which iron nail rusts?    abcd zinc coated nail painted nail nail in damp clothnail covered in grease     ",
            "13": "13  \u00a9 ucles 2009 0620/01/o/n/09 [turn over  34 a new planet has been discovered and its atmosphere has been analysed.    atmosphere planet     the table shows the composition of the atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only     35 water must be purified before it is suitable for use in the home.    which processes are used to remove solid impurities and bacteria?     to remove  solid impurities to remove  bacteria  a chlorination chlorination  b chlorination filtration  c filtration chlorination  d filtration filtration      36 fertilisers are used to provide three of the elements needed for plant growth.    which two compounds would give a fertiliser containing all three of these elements?  a ca(no 3)2 and (nh 4)2so 4  b ca(no 3)2 and (nh 4)3po 4  c kno 3 and (nh 4)2so 4  d kno 3 and (nh 4)3po 4 ",
            "14": "14  \u00a9 ucles 2009 0620/01/o/n/09  37 the apparatus shows an experiment used to test gas x.    gas x orange bromine solution     the bromine solution quickly becomes colourless.    what is the structure of gas x?    cch hhhb hca h hh hcc hh chhh hcd hh chho h      38 which statement about petroleum is not correct?  a it can be separated into useful substances by fractional distillation.  b it consists mainly of hydrocarbons.  c it is found underground in many parts of the world.  d its main use is for making lubricants and polishes.    39 butene and hexene belong to the same homologous series.    what is the same for butene and hexene?  a boiling point  b functional group  c number of hydrogen atoms per molecule  d relative molecular mass     ",
            "15": "15  \u00a9 ucles 2009 0620/01/o/n/09  40 the table shows the formulae of members of the alkane series.    name of compound formula  methane ch 4  ethane c 2h6  propane ?  butane c 4h10  pentane c 5h12    what is the formula of propane?  a c2h8 b c3h7 c c3h8 d c3h9     ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/01/o/n/09   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w09_qp_12.pdf": {
            "1": "    this document consists of 16 printed pages.  ib09 11_0620_12/3rp  \u00a9 ucles 2009  [turn over      *5151368285*  university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  october/november 2009       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2    \u00a9 ucles 2009 0620/12/o/n/09  1 a student separates salt from a mixture of salt and sand.    what is the correct order of steps for the student to take?  a filter \u2192 evaporate \u2192 shake with water  b filter \u2192 shake with water \u2192 evaporate  c shake with water \u2192 evaporate \u2192 filter  d shake with water \u2192 filter \u2192 evaporate     2 aqueous lead( ii) nitrate and aqueous potassium iodide are added to a dish containing water, as  shown.    aqueous lead( ii) nitrate aqueous potassium iodideyellow precipitate     a yellow precipitate forms after a few minutes.    which process occurs before the precipitate forms?  a diffusion  b distillation  c fermentation  d filtration     ",
            "3": "3  \u00a9 ucles 2009 0620/12/o/n/09 [turn over  3 a student carries out an experiment to prepare pure magnesium sulfate crystals.    the diagram shows the first stage of the preparation.    dilute sulfuric acidstirrer magnesium carbonate     he adds magnesium carbonate until no more reacts.    which process should he use for the next stage?  a crystallisation  b evaporation  c filtration  d neutralisation     4 which change to an atom occurs when it forms a positive ion?  a it gains electrons.  b it gains protons.  c it loses electrons.  d it loses protons.   5 statements 1, 2 and 3 are about diamond and graphite.    1 they are different solid forms of the same element.  2 they each conduct electricity.  3 they have atoms that form four equally strong bonds.     which statements are correct?  a 1 only b 3 only c 1 and 3 d 2 and 3     ",
            "4": "4    \u00a9 ucles 2009 0620/12/o/n/09  6 covalent bonds are formed when electrons are \u2026\u20261\u2026\u2026 . covalent compounds have \u2026\u20262\u2026\u2026  electrical conductivity.    which words correctly complete gaps 1 and 2?     1 2  a shared high  b shared low  c transferred high  d transferred low     7 atom x has 8 more electrons than atom y.    student 1 says they are in the same group.    student 2 says they are unreactive.    which students can be correct?     student 1 student 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     8 which number is different for isotopes of the same element?  a number of electrons  b number of full shells  c number of nucleons  d number of protons     9 which atom has two more electrons than an atom of a noble gas?  a aluminium  b bromine  c calcium  d rubidium     ",
            "5": "5  \u00a9 ucles 2009 0620/12/o/n/09 [turn over  10 for each atom of carbon present in a molecule, there is an equal number of atoms of oxygen but  twice as many atoms of hydrogen.    what is the formula of the molecule?  a c 2h2o2 b c 2h2o4 c c 2h4o2 d c 2h6o     11 water is formed when 48  g of oxygen combine with 6  g of hydrogen.    what mass of oxygen combines with 2  g of hydrogen?  a 12  g b 16  g c 96  g d 144  g     12 the diagram shows an electrical cable.    metal coreplastic coating     which statement about the substances used is correct?  a the coating is plastic because it conducts electricity well.  b the core is copper because it conducts electricity well.  c the core is copper because it is cheap and strong.  d the core is iron because it is cheap and strong.     ",
            "6": "6    \u00a9 ucles 2009 0620/12/o/n/09  13 the diagram shows how aluminium is manufactured by electrolysis.    cathode (\u2013ve) molten aluminiumaluminium  oxide  dissolved in  cryolite anode (+ve)     what are the anode and cathode made of?     anode cathode  a aluminium aluminium  b aluminium graphite  c graphite aluminium  d graphite graphite      14 the diagram shows the electrolysis of concentrated aqueous sodium chloride.    +\u2013positive electrodenegative electrode concentrated aqueous sodiumchloride anduniversal indicato rcarbon rods     what is the colour of the universal indicator at each electrode after five minutes?     colour at anode  (+ electrode) colour at cathode  (\u2013 electrode)  a blue/purple red  b red blue/purple  c red colourless  d colourless blue/purple ",
            "7": "7  \u00a9 ucles 2009 0620/12/o/n/09 [turn over  15 when an acid is added to an alkali the temperature rises.    which words describe this reaction?  a decomposition and endothermic  b decomposition and exothermic  c neutralisation and endothermic  d neutralisation and exothermic      16 substance x requires oxygen in order to produce energy.    it does not  form carbon dioxide as a result of this energy production.    what is substance x?  a hydrogen  b natural gas  c petrol  d 235u     17 which change does not increase the speed of reaction between zinc and hydrochloric  acid?  a adding a catalyst  b decreasing the temperature  c decreasing the particle size of the zinc  d using more concentrated acid     18 when blue copper( ii) sulfate is heated, a white solid and water are formed.    the white solid turns blue and gives out heat when water is added to it.    which terms describe the blue copper( ii) sulfate and the reactions?     the blue  copper( ii) sulfate is reaction  a a mixture can be reversed  b a mixture cannot be reversed  c hydrated can be reversed  d hydrated cannot be reversed        ",
            "8": "8    \u00a9 ucles 2009 0620/12/o/n/09  19 the equations represent redox reactions.    in which equation is the underlined substance acting as a reducing agent?  a cao + h 2o \u2192 ca(oh) 2  b co 2 + c \u2192 2co  c cuo + h 2 \u2192 cu + h 2o  d 3co + fe 2o3 \u2192 2fe + 3co 2      20 an aqueous solution y contains both barium ions and silver ions.    in separate experiments, dilute sulfuric acid and dilute hydrochloric acid are added to solution y.    which of these acids causes a precipitate to form in solution y?     dilute  sulfuric acid dilute  hydrochloric acid  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     21 the diagram shows the ph values of four solutions.    1 2 3 4 5 6 7 8 9 10 11 12 13 14     \u2191   \u2191  \u2191    \u2191    p q r s    which of these solutions are alkaline?  a p only  b p and q only  c q, r and s only  d r and s only    ",
            "9": "9  \u00a9 ucles 2009 0620/12/o/n/09 [turn over  22 salts can be prepared by reacting a dilute acid    1 with a metal;  2 with a base; 3 with a carbonate.    which methods could be used to prepare copper( ii) chloride?  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3      23 the diagram shows the position of an element x in the periodic table.    x    what is the correct classification of element x and its oxide?     x oxide of x  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic     24 elements in group 0 of the periodic table have uses.    these noble gases are \u2026\u20261.\u2026.. and this explains why argon \u2026\u20262\u2026\u2026 be used in lamps.    which words correctly complete gaps 1 and 2?     1 2  a reactive can  b reactive cannot  c unreactive can  d unreactive cannot ",
            "10": "10    \u00a9 ucles 2009 0620/12/o/n/09  25 astatine is an element in group vii of the periodic table. it has only ever been produced in very  small amounts.    what is the best description of its likely properties?     colour state reaction with aqueous  potassium iodide  a black solid no reaction  b dark brown gas brown colour  c green solid no reaction  d yellow liquid brown colour     26 which property do all metals have?  a they are soluble in water.  b they conduct electricity. c they have high melting points.  d they react with dilute sulfuric acid.     27 the table gives information about four elements.    which element is a transition metal?     colour  of element electrical conductivity  of element colour  of oxide  a black high colourless  b colourless low white  c grey high red  d yellow low colourless     ",
            "11": "11  \u00a9 ucles 2009 0620/12/o/n/09 [turn over  28 some reactions of three metals are listed in the table.    metal reacts with dilute  hydrochloric acid metal oxide is  reduced by carbon  p yes yes  q no yes  r yes no    what is the order of reactivity of the metals?     most  reactive  least  reactive  a p r q  b r p q  c r q p  d q p r      29 which object is least  likely to contain aluminium?  a a bicycle frame  b a hammer  c a saucepan  d an aeroplane body      30 which statement about alloys is not correct?  a alloys are more expensive than the metals they are made from.  b alloys are mixtures of different metals.  c alloys are not as strong as the metals they are made from.  d alloys conduct electricity well.     ",
            "12": "12    \u00a9 ucles 2009 0620/12/o/n/09  31 compound x is heated with carbon using the apparatus shown.    heatcompound x and carbon limewaterreaction tube     a brown solid is formed in the reaction tube and the limewater turns cloudy.    what is compound x?  a calcium oxide  b copper( ii) oxide  c magnesium oxide  d sodium oxide     32 water must be purified before it is suitable for use in the home.    which processes are used to remove solid impurities and bacteria?     to remove  solid impurities to remove  bacteria  a chlorination chlorination  b chlorination filtration  c filtration chlorination  d filtration filtration    ",
            "13": "13  \u00a9 ucles 2009 0620/12/o/n/09 [turn over  33 a newspaper article claims that carbon dioxide is formed as follows.    1 during respiration  2 when calcium carbonate reacts with hydrochloric acid 3 when methane burns in air    which statements are correct?  a 1, 2 and 3  b 1 and 2 only  c 1 and 3 only  d 2 and 3 only     34 which iron nail rusts?    abcd zinc coated nail painted nail nail in damp clothnail covered in grease     35 fertilisers are used to provide three of the elements needed for plant growth.    which two compounds would give a fertiliser containing all three of these elements?  a ca(no 3)2 and (nh 4)2so 4  b ca(no 3)2 and (nh 4)3po 4  c kno 3 and (nh 4)2so 4  d kno 3 and (nh 4)3po 4 ",
            "14": "14    \u00a9 ucles 2009 0620/12/o/n/09  36 a new planet has been discovered and its atmosphere has been analysed.    atmosphere planet     the table shows the composition of the atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only     37 butene and hexene belong to the same homologous series.    what is the same for butene and hexene?  a boiling point  b functional group  c number of hydrogen atoms per molecule  d relative molecular mass     38 which statement about petroleum is not correct?  a it can be separated into useful substances by fractional distillation.  b it consists mainly of hydrocarbons.  c it is found underground in many parts of the world.  d its main use is for making lubricants and polishes. ",
            "15": "15  \u00a9 ucles 2009 0620/12/o/n/09 [turn over  39 the apparatus shows an experiment used to test gas x.     gas x orange bromine solution     the bromine solution quickly becomes colourless.    what is the structure of gas x?    cch hhhb hca h hh hcc hh chhh hcd hh chho h      40 the table shows the formulae of members of the alkane series.    name of compound formula  methane ch 4  ethane c 2h6  propane ?  butane c 4h10  pentane c 5h12    what is the formula of propane?  a c2h8 b c3h7 c c3h8 d c3h9     ",
            "16": "16    permission to reproduce items where thir d-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. ca mbridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2009 0620/12/o/n/09  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w09_qp_2.pdf": {
            "1": "    this document consists of 17 printed pages and 3 blank pages.  ib09 11_0620_02/7rp  \u00a9 ucles 2009  [turn over      *2973907829* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/02     paper 2  october/november 2009     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name in the spaces at the top of this page.  write in dark blue or black pen. you may need to use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.    answer all questions. a copy of the periodic table is printed on page 20.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2009  0620/02/o/n/09  for  examiner's  use 1 the list shows some non-metallic elements.    bromine  carbon   fluorine  krypton   nitrogen   oxygen     (a) which two elements in the list are in the same group of the periodic table?   and  [1]      (b) which element in the list has the highest proton number?   [1]     (c) which two of these elements make up most of the air?   and  [1]     (d) bromine and fluorine form a compound with the formula brf 5.   calculate the relative molecular mass of brf 5.            [1]     (e) the diagram shows the structure of some compounds containing oxygen.    k+k+ k+k+o2\u2013 k+o2\u2013 k+k+k+ k+k+ k+o2\u2013 k+o2\u2013 k+o2\u2013ab c oc od on oo os     (i) what type of oxide is compound c?   [1]   ",
            "3": "3  \u00a9 ucles 2009  0620/02/o/n/09 [turn over  for  examiner's  use  (ii) compound a is an atmospheric pollutant.     describe the source of compound a and state its effect on the environment.  source   effect on the environment    [2]     (iii) in the presence of air, compound d reacts with water to form nitric acid.     a student used the apparatus below to add an aqueous solution of nitric acid to an  aqueous solution of potassium hydroxide. he added the acid until it was in excess.    flasksolution of nitric acid solution of potassium hydroxideburette      describe how the ph of the solution in the flask changes as the nitric acid is added  until the acid is in excess.        [3]     (iv) describe how you can measure this ph change.   [1]     (v) the equation for the reaction is       koh   +   hno 3  \u2192  kno 3  +   h 2o     state the name of the salt formed in this reaction.   [1]      [total: 12] ",
            "4": "4  \u00a9 ucles 2009  0620/02/o/n/09  for  examiner's  use 2 (a)  link the terms in the boxes on the left with the definitions on the right.  the first one has been done for you.    atoma substance containing different atoms or ions bonded together a substance made up of one type of atom the smallest part of an element which takes part in a chemical reaction the smallest group of covalently bonded atoms which can exist on its own a charged atom or group of atomscompound element ion molecule       [4]     (b) which two of the following are mixtures?    tick two boxes.    air      graphite      sodium chloride      steel       [1]     ",
            "5": "5  \u00a9 ucles 2009  0620/02/o/n/09 [turn over  for  examiner's  use  (c) (i)  draw a labelled diagram to show the atomic structure of an atom of helium.     in your diagram include the structure of the nucleus.                                 [4]       (ii) state a use for helium.   [1]    (iii) which one of these statements about helium is correct?    helium is in period 2 of the periodic table      helium is a liquid at room temperature      helium is unreactive      helium has an incomplete outer shell of electrons        [1]       [total: 11]   ",
            "6": "6  \u00a9 ucles 2009  0620/02/o/n/09  for  examiner's  use 3 a student used the apparatus shown to calculate the energy released when ethanol burns.    copper calorimeter water ethanolclamppoly(ethene) lidthermometer        (a) draw the structure of ethanol showing all atoms and bonds.                    [1]     (b) the energy released by the burning ethanol raises the temperature of the water in the copper calorimeter.      (i) which one of these words best describes the energy change when ethanol burns?   put a ring around the correct answer.    electrolytic  electronic  endothermic  exothermic    [1]    (ii)  when 4.6  g of ethanol is burnt, 5.4  g of water is formed.     calculate the mass of water formed when 13.8  g of ethanol is burnt.                   [1]    ",
            "7": "7  \u00a9 ucles 2009  0620/02/o/n/09 [turn over  for  examiner's  use  (iii) complete the equation for the combustion of ethanol.  c2h5oh      +      3o 2        \u2192  co 2         +  h 2o   [1]      (c) the calorimeter is made of copper. copper is a transition metal.    state two properties which distinguish transition metals from group i metals.     [2]       (d) when copper is left exposed to the air for some time, a coating of copper carbonate  forms on its surface.  the equation shows how copper carbonate reacts with hydrochloric acid.    cuco 3(s)   +   2hcl(aq)   \u2192   cucl 2(aq)   +   co 2(g)   +   h 2o(l)    (i) describe two observations that can be made as this reaction happens.  1.   2.  [2]    (ii) state the meaning of the symbol (aq).   [1]      (e) the calorimeter lid is made of poly(ethene).    complete these sentences about poly(ethene) using words from the list.   acids  addition  condensation  ethane  ethene    monomers   polymer     poly(ethene) is a  formed by the  of ethene molecules.  in this reaction the ethene molecules can be described as      [3]       [total: 12]  ",
            "8": "8  \u00a9 ucles 2009  0620/02/o/n/09  for  examiner's  use 4 caesium is a metal in group i of the periodic table.     (a) state two physical properties of caesium.     [2]      (b) state the number of electrons in the outer shell of a caesium atom.   [1]       (c) an isotope of caesium has a mass number of 133.    (i) what do you understand by the term isotope ?   [1]    (ii) calculate the number of neutrons in this isotope of caesium.   [1]      (d) complete the following table to estimate the boiling point of caesium and predict the  reactivity of caesium with water.    group i  metal density  /  g / cm3 boiling point   / \u00b0c reactivity with water  sodium 0.97 883 fizzes quickly, disappears gradually and does not burst into flame  potassium 0.86 760 fizzes very quickly, disappears quickly and bursts into flame with a little spitting  rubidium 1.53 686 fizzes extremely quickly, bursts into  flame then spits violently and may  explode  caesium 1.88         [2]    ",
            "9": "9  \u00a9 ucles 2009  0620/02/o/n/09 [turn over  for  examiner's  use  (e) the diagram shows the structure of caesium chloride.    cs+ cl \u2013 cs+ cl \u2013 cs+ cl \u2013cs+ cl \u2013 cs+ cl \u2013 cs+ cl \u2013cs+ cl \u2013 cs+ cl \u2013 cs+ cl \u2013       use this diagram to work out the simplest formula for caesium chloride.   [1]      (f) caesium chloride dissolves in water to form a neutral solution.     state the ph of a neutral solution.   [1]     (g) describe a test for chloride ions.  test   result     [2]        [total: 11]   ",
            "10": "10  \u00a9 ucles 2009  0620/02/o/n/09  for  examiner's  use 5 limonene is a colourless unsaturated hydrocarbon found in lemons.   the structure of limonene is shown below.     c ch cch2 ch2 h2c h2cch3 ch ch3     (a) on the formula above, draw a circle around the bonds which make limonene an unsaturated compound. [1]     (b) write the molecular formula for a molecule of limonene.   [1]       (c) describe the colour change which occurs when excess limonene is added to a few drops of bromine water.   [2]    ",
            "11": "11  \u00a9 ucles 2009  0620/02/o/n/09 [turn over  for  examiner's  use  (d) limonene can be extracted from lemon peel by steam distillation.    heatxba cwater lemon peel      (i) state the name of the pieces of apparatus labelled a, b and c.  a   b   c  [3]     (ii) at point x on the diagram, the water is in the form of steam.     describe the arrangement and the movement of the particles in steam.  arrangement   movement  [2]       (e) when limonene undergoes incomplete combustion, carbon monoxide is formed.    (i) what do you understand by the term incomplete combustion ?   [1]    (ii) state an adverse effect of carbon monoxide on health.   [1]     ",
            "12": "12  \u00a9 ucles 2009  0620/02/o/n/09  for  examiner's  use  (f) the structures of some compounds found in plants are shown below.    co2hh h hhc cco2hab h c hh hh oh cc nhhhd     (i)which one of these compounds is a carboxylic acid?  [1]    (ii)which one of these compounds is produced by the fermentation of glucose?        [1]    (iii)which one of these compounds is a hydrocarbon?  [1]        [total: 14] ",
            "13": "13  \u00a9 ucles 2009  0620/02/o/n/09 [turn over  for  examiner's  use 6 aluminium is extracted by the electrolysis of aluminium oxide.    aa+  \u2013 positive electrode  electrolyte (aluminium  oxide dissolved in molten cryolite)  dcb      (a) hydrated aluminium oxide is heated to produce pure aluminium oxide.    al2o3.3h 2o \u2192 al2o3     +     3h 2o  hydrated aluminium oxide        what type of reaction is this?   put a ring around the correct answer.   decompositon  neutralisation  oxidation  reduction        [1]     (b) explain why the electrolyte must be molten for electrolysis to occur.   [1]      (c) what is the purpose of the cryolite?   [1]     (d) which letter in the diagram, a, b, c or d, represents the cathode?   [1]     (e) state the name of the products formed at the anode and cathode during this electrolysis.  anode   cathode  [2]     (f) why do the anodes have to be renewed periodically?     [2]   ",
            "14": "14  \u00a9 ucles 2009  0620/02/o/n/09  for  examiner's  use  (g) complete the equation for the formation of aluminium from aluminium ions.   al 3+     +  e\u2212     \u2192     a l [1]      (h) state one use of aluminium.   [1]        [total: 10] ",
            "15": "15  \u00a9 ucles 2009  0620/02/o/n/09 [turn over  for  examiner's  use 7 the diagram shows an experiment to investigate the rusting of some iron nails.    a air distilled wateriron nailb air iron nailc air distilled wateriron nail coated with zinc drying agent (calcium chloride)     (a) for each tube a, b and c predict whether the nails will rust. in each case give a  reason.    tube a: does the nail rust?    reason tube b: does the nail rust?    reason tube c: does the nail rust?    reason        [3]     (b) iron from the blast furnace contains impurities such as carbon, phosphorus, silicon and sulfur.    describe how the level of these impurities is decreased when steel is made from  impure iron.          [3]      (c) state a use for stainless steel.   [1]     ",
            "16": "16  \u00a9 ucles 2009  0620/02/o/n/09  for  examiner's  use  (d) pure iron can be prepared by the reduction of iron( ii) oxide, feo.    feo   +   h 2   \u2192   fe   +   h 2o      explain how this equation shows that the iron( ii) oxide has been reduced.     [1]       (e) iron( ii) oxide reacts with acids.    feo   +   2hc l   \u2192   fec l2   +   h 2o     write a word equation for this reaction.   [2]         [total: 10]   ",
            "17": "17   0620/02/o/n/09   blank page",
            "18": "18   0620/02/o/n/09   blank page",
            "19": "19   0620/02/o/n/09   blank page",
            "20": "20    permission to reproduce items where thir d-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/02/o/n/09    group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w09_qp_31.pdf": {
            "1": "    this document consists of 14 printed pages and 2 blank pages.  ib09 11_0620_31/7rp  \u00a9 ucles 2009  [turn over      *7116024521* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/31     paper 3 (extended)  october/november 2009     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  questions.   ",
            "2": "2  \u00a9 ucles 2009 0620/31/o/n/09  for  examiner's  use 1 (a) the major gases in unpolluted air are 79  % nitrogen and 20  % oxygen.     (i) name another gaseous element in unpolluted air.   [1]     (ii) name two compounds in unpolluted air.   [2]      (b) two common pollutants in air are carbon monoxide and the oxides of nitrogen.    (i) name another pollutant in air.   [1]    (ii) describe how carbon monoxide is formed.       [2]     (iii) how are the oxides of nitrogen formed?       [2]     (iv) explain how a catalytic converter reduces the emission of these two gases.       [2]        [total: 10]  ",
            "3": "3  \u00a9 ucles 2009 0620/31/o/n/09 [turn over  for  examiner's  use 2 oxides are classified as acidic, basic, neutral and amphoteric.     (a) complete the table.    type of oxide ph of solution of oxide example  acidic    basic    neutral        [6]     (b) (i) explain the term amphoteric .     [1]       (ii) name two reagents that are needed to show that an oxide is amphoteric.     [2]        [total: 9]   ",
            "4": "4  \u00a9 ucles 2009 0620/31/o/n/09  for  examiner's  use 3 (a) an important ore of zinc is zinc blende, zns.     (i) how is zinc blende changed into zinc oxide?   [1]     (ii) write a balanced equation for the reduction of zinc oxide to zinc by carbon.   [2]     (b) a major use of zinc is galvanizing; steel objects are coated with a thin layer of zinc. this protects the steel from rusting even when the layer of zinc is broken.    thin layer of zincsteel exposed to oxygen and water steel    explain, by mentioning ions and electrons, why the exposed steel does not rust.             [3]   ",
            "5": "5  \u00a9 ucles 2009 0620/31/o/n/09 [turn over  for  examiner's  use  (c)  zinc electrodes have been used in cells for many years, one of the first was the daniel  cell in 1831.    zinc electrode copper electrode zinc sulfate(aq) copper(ii) sulfate(aq) porous pot - stops solutions from mixingvvoltmeter      (i) give an explanation for the following in terms of atoms and ions.     observation at zinc electrode \u2013 the electrode becomes smaller   explanation    [1]      observation at copper electrode \u2013 the electrode becomes bigger   explanation    [1]     (ii) when a current flows, charged particles move around the circuit.     what type of particle moves through the electrolytes?   [1]     which particle moves through the wires and the voltmeter?   [1]     [total: 10] ",
            "6": "6  \u00a9 ucles 2009 0620/31/o/n/09  for  examiner's  use 4 the distinctive smell of the seaside was thought to be caused by ozone, o 3.   ozone is a form of the element oxygen.     (a) a mixture of oxygen and ozone is formed by passing electric sparks through oxygen.    3o 2  2o 3     suggest a technique that might separate this mixture. explain why this method  separates the two forms of oxygen.  technique   explanation        [2]      (b) ozone is an oxidant. it can oxidise an iodide to iodine.    2i\u2013  +  o 3  +  2h+  \u2192  i2  + o 2  +  h 2o    (i) what would you see when ozone is bubbled through aqueous acidified potassium  iodide?         [2]     (ii) explain in terms of electron transfer why the change from iodide ions to iodine  molecules is oxidation.     [1]     (iii) explain, using your answer to b(ii), why ozone is the oxidant in this reaction.     [1]   ",
            "7": "7  \u00a9 ucles 2009 0620/31/o/n/09 [turn over  for  examiner's  use  (c) it is now known that the smell of the seaside is due to the chemical dimethyl sulfide,  (ch 3)2s.    (i) draw a diagram that shows the arrangement of the valency electrons in one molecule of this covalent compound.   use x to represent an electron from a carbon atom.  use o to represent an electron from a hydrogen atom.  use \u25cf to represent an electron from a sulfur atom.                       [3]   (ii) name the three  compounds formed when dimethyl sulfide is burnt in excess  oxygen.       [2]        [total: 11] ",
            "8": "8  \u00a9 ucles 2009 0620/31/o/n/09  for  examiner's  use 5 the first three elements in group iv are carbon, silicon and germanium.   the elements and their compounds have similar properties.    (a) the compound, silicon carbide, has a macromolecular structure similar to that of diamond.    (i) a major use of silicon carbide is to reinforce aluminium alloys which are used in the construction of spacecraft. suggest three  of its physical properties.       [3]     (ii) complete the following description of the structure of silicon carbide.  each carbon atom is bonded to four   atoms.  each silicon atom is bonded to   carbon atoms. [2]       (b) germanium( iv) oxide, geo 2, has the same macromolecular structure as silicon( iv)  oxide. draw the structural formula of germanium( iv) oxide.                     [3] ",
            "9": "9  \u00a9 ucles 2009 0620/31/o/n/09 [turn over  for  examiner's  use  (c) germanium forms a series of hydrides comparable to the alkanes.     (i) draw the structural formula of the hydride which contains four germanium atoms per molecule.                        [1]   (ii) predict the products of the complete combustion of this hydride.    [2]        [total: 11]  ",
            "10": "10  \u00a9 ucles 2009 0620/31/o/n/09  for  examiner's  use 6 (a) sulfuric acid is made by the contact process.    2so 2  +  o 2    2so 3      this is carried out in the presence of a catalyst at 450  \u00b0c and 2 atmospheres pressure.     (i) how is the sulfur dioxide made?     [1]      (ii) give another use of sulfur dioxide.   [1]       (iii) name the catalyst used.   [1]     (iv) if the temperature is decreased to 300  \u00b0c, the yield of sulfur trioxide increases.  explain why this lower temperature is not used.     [1]     (v) sulfur trioxide is dissolved in concentrated sulfuric acid. this is added to water to  make more sulfuric acid. why is sulfur trioxide not added directly to water?     [1]     ",
            "11": "11  \u00a9 ucles 2009 0620/31/o/n/09 [turn over  for  examiner's  use  (b) sulfuric acid was first made in the middle east by heating the mineral, green vitriol,  feso 4.7h 2o. the gases formed were cooled.      feso 4.7h 2o(s)      \u2192      feso 4(s)      +     7h 2o(g)    green crystals yellow powder    2feso 4(s)    \u2192    fe 2o3(s)   +   so 2(g)  +  so 3(g)    on cooling   so 3  +   h 2o   \u2192  h2so 4   sulfuric acid    so 2  +   h 2o   \u2192  h2so 3   sulfurous acid     (i) how could you show that the first reaction is reversible?     [2]     (ii) sulfurous acid is a reductant. what would you see when acidified potassium  manganate( vii) is added to a solution containing this acid?     [2]     (iii) suggest an explanation why sulfurous acid in contact with air changes into sulfuric acid.   [1]     (c) 9.12  g of anhydrous iron( ii) sulfate was heated. calculate the mass of iron( iii) oxide  formed and the volume of sulfur trioxide, at r.t.p., formed.      2feso 4(s)  \u2192  fe 2o3(s)  +  so 2(g)  +  so 3(g)    mass of one mole of feso 4  =  152  g  number of moles of feso 4 used =    number of moles of fe 2o3  formed =    mass of one mole of fe 2o3 =  g  mass of iron( iii) oxide formed  =  g  number of moles of so 3 formed  =    volume of sulfur trioxide formed  =  dm3   [6]        [total: 16] ",
            "12": "12  \u00a9 ucles 2009 0620/31/o/n/09  for  examiner's  use 7 butan-1-ol is used as a solvent for paints and varnishes, to make esters and as a fuel.  butan-1-ol can be manufactured from but-1-ene, which is made from petroleum.     biobutanol is a fuel of the future. it can be made by the fermentation of almost any form of biomass - grain, straw, leaves etc.    (a) but-1-ene can be obtained from alkanes such as decane, c 10h22, by cracking.    (i) give the reaction conditions.     [2]     (ii) complete an equation for the cracking of decane, c 10h22, to give but-1-ene.  c10h22    \u2192  [2]     (iii) name the reagent that reacts with but-1-ene to form butan-1-ol.   [1]       (b) (i)  balance the equation for the complete combustion of butan-1-ol.     c 4h9oh  +    o2  \u2192  co 2  +   h 2o [2]     (ii) write a word equation for the preparation of the ester butyl methanoate.   [2]    ",
            "13": "13  \u00a9 ucles 2009 0620/31/o/n/09 [turn over  for  examiner's  use  (c) the fermentation of biomass by bacteria produces a mixture of products which include  biobutanol, propanol, hydrogen and propanoic acid.    (i) draw the structural formula of propanol and of propanoic acid. show all the bonds.     propanol               propanoic acid                  [2]    (ii) why is it important to develop these fuels, such as biobutanol, as alternatives to petroleum?   [1]    (d) how could you show that butanol made from petroleum and biobutanol are the same chemical?     [1]       [total: 13]  ",
            "14": "14   0620/31/o/n/09   blank page",
            "15": "15   0620/31/o/n/09  blank page",
            "16": "16    permission to reproduce items where thir d-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/31/o/n/09   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w09_qp_32.pdf": {
            "1": "    this document consists of 14 printed pages and 2 blank pages.  ib09 11_0620_32/7rp  \u00a9 ucles 2009  [turn over      *4230027975* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/32     paper 3 (extended)  october/november 2009     1 hour 15 minutes    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions. a copy of the periodic table is printed on page 16.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  questions.   ",
            "2": "2  \u00a9 ucles 2009 0620/32/o/n/09  for  examiner's  use 1 (a) the major gases in unpolluted air are 79  % nitrogen and 20  % oxygen.     (i) name another gaseous element in unpolluted air.   [1]     (ii) name two compounds in unpolluted air.   [2]      (b) two common pollutants in air are sulfur dioxide and the oxides of nitrogen.    (i) name another pollutant in air.   [1]    (ii) describe how sulfur dioxide is formed.       [2]     (iii) how are the oxides of nitrogen formed?       [2]     (c) how is oxygen obtained from air?       [2]     [total: 10]    ",
            "3": "3  \u00a9 ucles 2009 0620/32/o/n/09 [turn over  for  examiner's  use 2 oxides are classified as acidic, basic, neutral and amphoteric.     (a) complete the table.    type of oxide ph of solution of oxide example  acidic    basic    neutral     [6]     (b) (i) explain the term amphoteric .     [1]       (ii) how could you distinguish between an acidic oxide and an amphoteric oxide using  hydrochloric acid and aqueous sodium hydroxide?     [2]     [total: 9]     ",
            "4": "4  \u00a9 ucles 2009 0620/32/o/n/09  for  examiner's  use 3 (a) an important ore of zinc is zinc blende, zns.     (i) how is zinc blende changed into zinc oxide?   [1]     (ii) write a balanced equation for the reduction of zinc oxide to zinc by carbon.   [2]      (b) a major use of zinc is galvanizing; steel objects are coated with a thin layer of zinc.  this protects the steel from rusting even when the layer of zinc is broken.    thin layer of zincsteel exposed to oxygen and water steel     explain, by mentioning ions and electrons, why the exposed steel does not rust.             [3]   ",
            "5": "5  \u00a9 ucles 2009 0620/32/o/n/09 [turn over  for  examiner's  use  (c)  zinc electrodes have been used in cells for many years, one of the first was the daniel  cell in 1831.    zinc electrode copper electrode zinc sulfate(aq) copper(ii) sulfate(aq) porous pot - stops solutions from mixingvvoltmeter      (i) give an explanation for the following in terms of atoms and ions.     observation at zinc electrode \u2013 the electrode becomes smaller   explanation    [1]     observation at copper electrode \u2013 the electrode becomes bigger   explanation    [1]     (ii) when a current flows, charged particles move around the circuit.     what type of particle moves through the electrolytes?   [1]     which particle moves through the wires and the voltmeter?   [1]     [total: 10] ",
            "6": "6  \u00a9 ucles 2009 0620/32/o/n/09  for  examiner's  use 4 the distinctive smell of the seaside was thought to be caused by ozone, o 3.   ozone is a form of the element oxygen.     (a) a mixture of oxygen and ozone is formed by passing electric sparks through oxygen.    3o 2  2o 3    suggest a technique that might separate this mixture. explain why this method  separates the two forms of oxygen.  technique   explanation        [2]     (b) ozone is an oxidant. it can oxidise an iodide to iodine.    2 i\u2013  +  o 3  +  2h+  \u2192  i2  +  o 2  +  h 2o     (i)  what would you see when ozone is bubbled through aqueous acidified potassium  iodide?         [2]     (ii) explain in terms of electron transfer why the change from iodide ions to iodine molecules is oxidation.       [1]     (iii) explain, using your answer to b(ii), why ozone is the oxidant in this reaction.     [1]     ",
            "7": "7  \u00a9 ucles 2009 0620/32/o/n/09 [turn over  for  examiner's  use (c) it is now known that the smell of the seaside is due to the chemical dimethyl sulfide,  (ch 3)2s.    (i) draw a diagram that shows the arrangement of the valency electrons in one molecule of this covalent compound.   use x to represent an electron from a carbon atom.  use o to represent an electron from a hydrogen atom.  use \u25cf to represent an electron from a sulfur atom.                    [3]   (ii) name the three  compounds formed when dimethyl sulfide is burnt in excess  oxygen.       [2]     [total: 11] ",
            "8": "8  \u00a9 ucles 2009 0620/32/o/n/09  for  examiner's  use 5 the first three elements in group iv are carbon, silicon and germanium.   the elements and their compounds have similar properties.     (a) the compound, silicon carbide, has a macromolecular structure similar to that of diamond.    (i) a major use of silicon carbide is to reinforce aluminium alloys which are used in  the construction of spacecraft. suggest three  of its physical properties.       [3]     (ii) draw a diagram to show the arrangement of silicon atoms around one carbon atom in silicon carbide. label this diagram 1.  draw a diagram to show the arrangement of carbon atoms around one silicon  atom in silicon carbide. label this diagram 2.              [3]      (b) germanium( iv) oxide, geo 2, has the same macromolecular structure as silicon( iv)  oxide. draw the structural formula of germanium( iv) oxide.                 [2]   ",
            "9": "9  \u00a9 ucles 2009 0620/32/o/n/09 [turn over  for  examiner's  use (c) germanium forms a series of hydrides comparable to the alkanes.     (i) draw the structural formula of the hydride which contains three germanium atoms  per molecule.                     [1]   (ii) predict the products of the complete combustion of this hydride.   [2]     [total: 11] ",
            "10": "10  \u00a9 ucles 2009 0620/32/o/n/09  for  examiner's  use 6 (a) sulfuric acid is made by the contact process.    2so 2  +  o 2    2so 3     this is carried out in the presence of a catalyst at 450  \u00b0c and 2 atmospheres pressure.     (i) sulfur dioxide is made by burning sulfur. name a source of sulfur.     [1]     (ii) give another use of sulfur dioxide.   [1]     (iii) name the catalyst used.   [1]     (iv) if the temperature is decreased to 300  \u00b0c, the yield of sulfur trioxide increases.  explain why this lower temperature is not used.     [1]     (v) sulfur trioxide is dissolved in concentrated sulfuric acid. this is added to water to make more sulfuric acid. why is sulfur trioxide not added directly to water?     [1]     ",
            "11": "11  \u00a9 ucles 2009 0620/32/o/n/09 [turn over  for  examiner's  use  (b) sulfuric acid was first made in the middle east by heating the mineral, green vitriol,  feso 4.7h 2o. the gases formed were cooled.     feso 4.7h 2o(s)      \u2192      feso 4(s)      +     7h 2o(g)   green crystals yellow powder   2feso 4(s)    \u2192    fe2o 3(s)   +   so 2(g)  +  so 3(g)   on cooling   so 3  +   h 2o   \u2192  h2so 4   sulfuric acid   so 2  +   h 2o   \u2192  h2so 3  sulfurous acid     (i) how could you show that the first reaction is reversible?     [2]     (ii) sulfurous acid is a reductant. what would you see when acidified potassium  manganate( vii) is added to a solution containing this acid?     [2]     (iii) suggest an explanation why sulfurous acid in contact with air changes into sulfuric  acid.   [1]     (c) 12.16  g of anhydrous iron( ii) sulfate was heated. calculate the mass of iron( iii) oxide  formed and the volume of gases, at r.t.p., formed.     2feso 4 (s)    \u2192    fe 2o3(s)   +   so 2(g)  +  so 3(g)    mass of one mole of feso 4  =  152   g  number of moles of feso 4 used =    number of moles of fe 2o3 formed =    mass of one mole of fe 2o3 =  g  mass of iron( iii) oxide formed =  g  total number of moles of gases formed =    total volume of gases formed =  dm3   [6]     [total: 16] ",
            "12": "12  \u00a9 ucles 2009 0620/32/o/n/09  for  examiner's  use 7 butan-1-ol is used as a solvent for paints and varnishes, to make esters and as a fuel.  butan-1-ol can be manufactured from but-1-ene, which is made from petroleum.     biobutanol is a fuel of the future. it can be made by the fermentation of almost any form of  biomass - grain, straw, leaves etc.    (a) but-1-ene can be obtained from alkanes such as nonane, c 9h20, by cracking.    (i) give the reaction conditions.     [2]     (ii) complete an equation for the cracking of nonane, c 9h20, to give but-1-ene.  c9h20    \u2192  [2]    (iii) name the reagent that reacts with but-1-ene to form butan-1-ol.   [1]      (b) (i)  balance the equation for the complete combustion of butan-1-ol.     c 4h9oh  +    o2  \u2192  co 2  +   h 2o [2]     (ii) write a word equation for the preparation of the ester butyl propanoate.   [2]    ",
            "13": "13  \u00a9 ucles 2009 0620/32/o/n/09  for  examiner's  use  (c) the fermentation of biomass by bacteria produces a mixture of products which include  biobutanol, propanol, hydrogen and propanoic acid.    (i) draw the structural formula of propanol and of propanoic acid. show all the bonds.     propanol               propanoic acid                [2]    (ii) why is it important to develop these fuels, such as biobutanol, as alternatives to petroleum?   [1]     (d) how could you show that butanol made from petroleum and biobutanol are the same chemical?     [1]    [total: 13]   ",
            "14": "14   0620/32/o/n/09  blank page",
            "15": "15   0620/32/o/n/09  blank page",
            "16": "16    permission to reproduce items where thir d-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/32/o/n/09  group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_w09_qp_5.pdf": {
            "1": "    this document consists of 7 printed pages and 1 blank pages.  ib09 11_0620_05/4rp  \u00a9 ucles 2009  [turn over      *9223011686* for examiner's use  1   2   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/05     paper 5 practical test  october/november 2009     1 hour 15 minutes    candidates answer on the question paper .    additional materials: as listed in instructions to supervisors      read these instructions first    write your, centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid.  do not write in any barcodes  answer all questions.  practical notes are provided on page 8.   at the end of the examination, fasten all you work securely together.  the number of marks is given in brackets [  ] at the end of each question or part question.   ",
            "2": "2  \u00a9 ucles 2009 0620/05/o/n/09  for  examiner's  use 1 you are going to investigate the temperature rise produced when equal lengths of  magnesium ribbon react with excess dilute sulfuric acid of different concentrations (labelled a, b, c, and d).    read all the instructions below carefully before  starting the experiments.     instructions     pour about 4  cm3 of solution a into a test-tube. add a piece of magnesium ribbon to the  tube. note your observations and test the gas.  observations    [1]   test for gas   result  [2]     experiment 1  by using a measuring cylinder, pour 20  cm3 of solution a into the beaker provided. measure  the initial temperature of the solution and record it in the table below. add one length of  magnesium ribbon to the solution in the beaker, and stir the mixture with the thermometer. record the highest temperature reached.   remove the thermometer and rinse out the beaker with water.     experiment 2   repeat experiment 1 using solution b instead of solution a. record the initial and final  temperatures in the table.    rinse out the beaker.   experiment 3   repeat experiment 1, using solution c. record the temperatures in the table.    experiment 4   repeat experiment 1 using solution d. record the temperatures in the table.      table of results    solution of  sulfuric acid initial temperature  / \u00b0c highest temperature  / \u00b0cchange in  temperature  / \u00b0c  a     b     c     d        [4] ",
            "3": "3  \u00a9 ucles 2009 0620/05/o/n/09 [turn over  for  examiner's  use  (a) work out the temperature change for each experiment and record the value in the  table. [1]     (b) draw a labelled bar chart of the results to experiments 1, 2, 3 and 4 on the grid below.    16 141210 8642change in temperature /  \u00b0c      [4]    ",
            "4": "4  \u00a9 ucles 2009 0620/05/o/n/09  for  examiner's  use  use your results and observations to answer the following questions.    (c) (i)  name the gas given off when magnesium reacts with dilute sulfuric acid.   [1]     (ii) what type of chemical reaction occurs when magnesium reacts with dilute sulfuric  acid?   [1]      (d) (i)  which experiment produced the largest temperature change?   [1]     (ii) suggest why this experiment produced the largest temperature change.     [1]      (e) predict the effect on the temperature changes that would happen if     (i) equal masses of magnesium powder were used in the experiments,   [1]     (ii) 40  cm3 of dilute sulfuric acid was used in experiment 1.   [1]    (iii) explain your answer to (e)(ii) .     [1]       (f) give one possible source of experimental error in this investigation.     [1]       [total: 20]   ",
            "5": "5  \u00a9 ucles 2009 0620/05/o/n/09 [turn over  for  examiner's  use 2 you are provided with three solutions k, l and m.   carry out the following tests on the solutions, recording all of your observations in the table.  do not write any conclusions in the table.    tests observations  (a) describe the appearance  of the solutions.   solution k      solution l      solution m   [1]     (b) using universal indicator paper, test the ph of each solution.   solution k  ph     solution l  ph     solution m  ph  [2]       tests on solution k     (c) (i)  by using a teat pipette, add drops of  solution k to about   3  cm3 of copper sulfate  solution in a test-tube.           now add an excess of  solution k to the test  tube.  [2]          [2]  (ii)  repeat experiment  (c)(i)  using aqueous  aluminium sulfate  instead of aqueous copper sulfate.     (iii)  to about 3  cm3 of  solution k add a few  drops of nitric acid and  about 1  cm3 of silver  nitrate solution.    [1]      ",
            "6": "6  \u00a9 ucles 2009 0620/05/o/n/09  for  examiner's  use tests observations  tests on solution l   (d) (i) repeat experiment  (c)(i)  using solution l    [1]               (ii)repeat experiment (c)(ii)  using solution l    [2]      [1]  (iii)repeat experiment  (c)(iii)  using  solution l            tests on solution m   (e) repeat experiment c(iii)  using solution m    [2]           (f) what conclusions can you make about solution k?     [2]      (g) what conclusions can you make about solution l?     [2]      (h) identify solution m.   [2]       [total: 20 marks]   ",
            "7": "7    permission to reproduce items where t hird-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2009 0620/05/o/n/09  blank page   ",
            "8": "8  \u00a9 ucles 2009 0620/05/o/n/09 notes for use in qualitative analysis     test for anions     anion test test result  carbonate (co 32\u2013) add dilute acid effervescence, carbon dioxide  produced  chloride (c l \u2013)  [in solution] acidify with dilute nitric acid, then  add aqueous silver nitrate white ppt.  iodide ( i\u2013)  [in solution] acidify with dilute nitric acid, then add aqueous silver nitrate yellow ppt.  nitrate (no 3\u2013)  [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced  sulfate (so 42\u2013)  [in solution] acidify, then add aqueous barium nitrate white ppt.    test for aqueous cations     cation effect of aqueous sodium hydroxide effect of aqueous ammonia  aluminium (a l 3+) white ppt., soluble in excess giving  a colourless solution white ppt., insoluble in excess  ammonium (nh 4+) ammonia produced on warming -  calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt.  copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess  giving a dark blue solution  iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess  iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess  zinc (zn2+) white ppt., soluble in excess giving  a colourless solution white ppt., soluble in excess giving  a colourless solution    test for gases     gas test and test results  ammonia (nh 3) turns damp red litmus paper blue  carbon dioxide (co 2) turns limewater milky  chlorine (c l2) bleaches damp litmus paper  hydrogen (h 2) \u201cpops\u201d with a lighted splint  oxygen (o 2) relights a glowing splint   "
        },
        "0620_w09_qp_6.pdf": {
            "1": "    this document consists of 12 printed pages.  ib09 11_0620_06/5rp  \u00a9 ucles 2009  [turn over      *3567155373* for examiner's use  1   2   3   4   5   6   7   total   university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/06     paper 6 alternative to practical  october/november 2009     1 hour    candidates answer on the question paper.    no additional materials are required.      read these instructions first    write your centre number, candidate number and name on all the work you hand in.  write in dark blue or black pen. you may use a pencil for any diagrams, graphs or rough working. do not use staples, paper clips, highlighters, glue or correction fluid. do not  write in any barcodes.   answer all questions.  at the end of the examination, fasten all your work securely together.  the number of marks is given in brackets [  ] at the end of each question or part  question.   ",
            "2": "2  \u00a9 ucles 2009 0620/06/o/n/09  for  examiner's  use 1 the apparatus below was used to make oxygen. the tube of manganese oxide was added  to the hydrogen peroxide solution by releasing the cotton.    40 20 60 100 cm3 80  hydrogen  peroxide cotton  tube containing  manganese oxide      (a) complete the boxes to identify the pieces of apparatus. [2]     (b) why was the tube of manganese oxide suspended in the flask?   [1]       (c) give a test for oxygen.  test   result  [2]     [total: 5]   ",
            "3": "3  \u00a9 ucles 2009 0620/06/o/n/09 [turn over  for  examiner's  use 2 a steel spoon can be coated in silver usin g electrolysis. the spoon must be very clean and  free of grease.    metal electrode electrolytespoon      (a) suggest     (i) one  advantage of putting a thin layer of silver on the spoon,   [1]     (ii) one disadvantage if the spoon is used frequently,   [1]     (iii) why the spoon must be very clean and free of grease?   [1]     (b) which electrode should be the spoon?   [1]       (c) identify the metal from which the other electrode is made.   [1]     [total: 5] ",
            "4": "4  \u00a9 ucles 2009 0620/06/o/n/09  for  examiner's  use 3 three unlabelled bottles of chemicals each contained one of the following liquids:    \u007f sodium nitrate dissolved in water;  \u007f pure water;  \u007f hexene.     (a) give a test by which you could identify sodium nitrate solution.  test   result  [2]       (b) give a test by which you could identify pure water.   test   result  [2]       (c) give a test by which you could identify hexene.  test   result  [2]          [total: 6]   ",
            "5": "5  \u00a9 ucles 2009 0620/06/o/n/09 [turn over  for  examiner's  use 4 a student investigated the temperature change produced when equal lengths of  magnesium ribbon reacted with excess dilute sulfuric acid of different concentrations (labelled solutions a, b, c, d and e).   five experiments were carried out.     experiment 1     using a measuring cylinder, 20  cm3 of sulfuric acid solution a was poured into a beaker.  the initial temperature of the solution was measured. a length of magnesium ribbon was added to the solution and stirred. the highest temperature reached was measured.     experiment 2     experiment 1 was repeated using solution b instead of solution a. the initial and highest  temperatures were measured as before.      experiment 3     experiment 1 was repeated using solution c. the initial and highest temperatures were  measured.    experiment 4     experiment 1 was repeated using solution d. the initial and highest temperatures were  measured.    experiment 5     experiment 1 was repeated using solution e. the initial and highest temperatures were  measured.    use the thermometer diagrams in the table on page 6, to record the initial and highest  temperatures in each experiment. ",
            "6": "6  \u00a9 ucles 2009 0620/06/o/n/09  for  examiner's  use   solution of sulfuric acid a b cd ethermometer diagraminitial temperature /  \u00b0cthermometer diagramhighest temperature / \u00b0cchange in temperature / \u00b0c 30 25 20 30 25 20 30 25 20 30 25 20 30 25 2040 35 30 40 35 30 40 35 30 35 30 25 30 25 20     [4]    (a) work out the temperature change for each experiment and record the values in the table. [1]    ",
            "7": "7  \u00a9 ucles 2009 0620/06/o/n/09 [turn over  for  examiner's  use  (b) draw a labelled bar chart of the results for experiments 1, 2, 3, 4 and 5 on the grid  below. [4]    change in temperature/  \u00b0c         use the results and observations to answer the following questions.    (c) what type of chemical reaction occurs when magnesium reacts with dilute sulfuric acid?   [1]     (d) (i) which experiment produced the largest temperature change?   [1]    (ii) suggest why this experiment produced the largest temperature change.     [1]     ",
            "8": "8  \u00a9 ucles 2009 0620/06/o/n/09  for  examiner's  use  (e) predict the effect on the temperature changes that would happen if     (i) equal masses of magnesium powder were used in the experiments.   [1]     (ii) 40  cm3 of dilute sulfuric acid was used in experiment 1.   [1]     (iii) explain your answer to (e)(ii) .     [1]      (f) give one  possible source of experimental error in this investigation.     [1]      [total: 16]   ",
            "9": "9  \u00a9 ucles 2009 0620/06/o/n/09 [turn over  for  examiner's  use 5 three aqueous solutions k, l and m, were analysed. l was a solution of sodium hydroxide.    the tests on the solutions and some of the observations are in the table.    complete the observations in the table. do not write any conclusions in the table.    tests observations  (a) appearance of the solutions.    solution k    solution l    solution m       colourless liquid   colourless liquid   colourless liquid  (b) universal indicator paper was used to test the ph of each  solution.   solution k ph 10    solution l ph  [1]   solution m ph 2  (c)  (i) (ii)      (iii)tests on solution k   drops of solution k were  added to copper sulfate solution in a test-tube. excess of solution k was then  added to the test-tube.   experiment (c)(i)  was  repeated using aqueous  aluminium sulfate instead of  aqueous copper sulfate.    a few drops of nitric acid and  silver nitrate solution were  added to solution k.        pale blue precipitate formed    deep blue solution formed        white precipitate formed  insoluble in excess      no visible reaction  (d) tests on solution l      (i) experiment (c)(i)  was  repeated using solution l.   [1]   (ii) experiment (c)(ii)  was  repeated using solution l.         [3]  (e) test on solution m  experiment (c)(iii)  was  repeated using solution m.     white precipitate formed ",
            "10": "10  \u00a9 ucles 2009 0620/06/o/n/09  for  examiner's  use  (f) what conclusions can you make about solution k?     [2]       (g) what conclusions can you make about solution m?     [2]       [total: 9]                 6 dilute hydrochloric acid was added to excess calcium carbonate in a beaker as shown.    cotton wool hydrochloric acid balancecalcium carbonate 184.0      the beaker was placed on a balance and the mass of the beaker and contents recorded  every minute.   the results are shown in the table.    mass of beaker and contents  / g 184.0 178.0 175.6 174.6 174.0 174.0  time  / min 0 1 2 3 4 5   ",
            "11": "11  \u00a9 ucles 2009 0620/06/o/n/09 [turn over  for  examiner's  use  (a) plot the results on the grid and draw a smooth line graph.        [5]     (b) use your graph to determine the mass of the beaker and contents after 30 seconds.    show clearly on your graph how you worked out your answer.   [2]       (c) why does the mass of the beaker and contents decrease?   [1]      (d) suggest the purpose of the cotton wool.   [1]      (e) after how long did the reaction finish?   [1]      (f) a second experiment was carried out using hydrochloric acid at a lower temperature.   on the grid sketch a curve to show the expected results for this experiment.   label this curve c. [2]     [total: 12] ",
            "12": "12    permission to reproduce items where thir d-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the p ublisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   university of cambridge international examinations is part of  the cambridge assessment group. cambridge assessment is the brand name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    0620/06/o/n/09 for  examiner's  use 7 leaves from trees contain a mixture of coloured pigments which are not soluble in water. a  student was given these two instructions to investigate the pigments in the leaves.    1. crush some leaves to extract the coloured pigments.  2. use the liquid extract to find the number of coloured pigments in the leaves.    (a) what would the student need in order to effectively carry out instruction 1?         [3]      (b) describe an experiment to carry out instruction 2.    a space has been left below if you want to draw a diagram to help answer the question.                                      [4]     [total: 7] "
        }
    },
    "2010": {
        "0620_s10_qp_11.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib10 06_0620_11/rp  \u00a9 ucles 2010  [turn over       *9829839277* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  may/june 2010       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2010 0620/11/m/j/10  1 the diagram shows a cup of tea.        which row describes the water particles in the air above the cup compared with the water  particles in the cup?     moving faster closer together  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    2 a fruit drink coloured orange contains a dissolved mixture of red and yellow colouring agents.  one of these colouring agents is suspected of being illegal.    which method could be used to show the presence of this illegal colouring agent?  a chromatography  b distillation  c evaporation  d filtration     3 a student carries out an experiment to find how fast 3  cm pieces of magnesium ribbon dissolve in  10  cm3 samples of sulfuric acid at different temperatures.    which piece of apparatus does the student not need?  a balance  b measuring cylinder  c stop-clock  d thermometer     ",
            "3": "3  \u00a9 ucles 2010 0620/11/m/j/10 [turn over  4 which row shows the change that takes place when element x gains the new particle shown?     particle gained change  a electron an isotope of element x is formed  b electron the element one place to the right of x in the periodic table is formed  c proton an isotope of element x is formed  d proton the element one place to the right of x in the periodic table is formed     5 the diagram shows an atom.    ee eeelectron nucleus containing nine particlesekey     what is the proton number and neutron number of the atom?     proton  number neutron  number  a 4 5  b 4 9  c 5 4  d 5 9    6 the symbols of two atoms may be written as shown.    x52 23 y52 24    which statement about these atoms is correct?  a they are different elements because they have different numbers of neutrons.  b they are different elements because they have different numbers of protons.  c they are isotopes of the same element because they have the same nucleon number.  d they are isotopes of the same element because they have the same proton number.     ",
            "4": "4  \u00a9 ucles 2010 0620/11/m/j/10  7 which name is given to mixtures of metals?  a alloys  b compounds  c ores  d salts      8 element x has six electrons in its outer shell.    = electronkey e eee eee     how could the element react?  a by gaining two electrons to form a positive ion  b by losing six electrons to form a negative ion  c by sharing two electrons with two electrons from another element to form two covalent bonds  d by sharing two electrons with two electrons from another element to form four covalent bonds      9 in which compounds are pairs of electrons shared between atoms?    1 sodium chloride  2 methane  3 lead bromide    a 1 only b 2 only c 1 and 3 d 1, 2 and 3      10 hydrogen and chlorine react as shown.    1 molecule  of hydrogen + 1 molecule of chlorine \u2192 2 molecules  of hydrogen chloride   what is the equation for this reaction?  a 2h + 2c l \u2192 2hc l  b 2h + 2c l \u2192 h2cl 2  c h 2 + c l 2 \u2192 2hc l  d h 2 + c l 2 \u2192 h2cl 2     ",
            "5": "5  \u00a9 ucles 2010 0620/11/m/j/10 [turn over  11 the diagram shows apparatus for plating a spoon with silver.    spoon metal electrode electrolyte    which statement is not correct?  a silver would stick to the spoon because it is a very reactive metal.  b the electrolyte would be a silver salt dissolved in water.  c the metal electrode would be made from silver.  d the spoon would be connected to the negative of the power supply.     12 aqueous copper( ii) sulfate solution is electrolysed using inert electrodes.    copper( ii) ions (cu 2+), hydrogen ions (h+), hydroxide ions (oh\u2013) and sulfate ions (\u22122 4so ) are  present in the solution.    to which electrodes are the ions attracted during this electrolysis?     attracted to anode attracted to cathode  a cu2+ and h+ oh\u2013 and \u22122 4so   b cu2+ and \u22122 4so  h+ and oh\u2013  c h+ and oh\u2013 cu2+ and \u22122 4so   d oh\u2013 and \u22122 4so  cu2+ and h+     13 three electrolysis cells are set up. each cell has inert electrodes.     the electrolytes are listed below.    cell 1 aqueous sodium chloride  cell 2 concentrated hydrochloric acid cell 3 molten lead( ii) bromide    in which cells is a gas formed at both  electrodes?  a 1 and 2 b 1 and 3 c 2 only d 3 only     ",
            "6": "6  \u00a9 ucles 2010 0620/11/m/j/10  14 clouds are formed when water vapour evaporates from the sea.    clouds seawater vapou r     what is the energy change and what name is given to the type of change when water  evaporates?     energy change type of change  a energy given out endothermic  b energy given out exothermic  c energy taken in endothermic  d energy taken in exothermic      15 which process is not exothermic?  a burning a fossil fuel  b obtaining lime from limestone  c radioactive decay of 235u  d reacting hydrogen with oxygen     ",
            "7": "7  \u00a9 ucles 2010 0620/11/m/j/10 [turn over  16 a student investigates the rate of reaction between marble chips and hydrochloric acid.    the loss in mass of the reaction flask is measured.     the graph shows the results of two experiments, p and q.    0mass of reaction flask timep q     which change explains the difference between p and q?  a a catalyst is added in p.  b a higher temperature is used in p.  c bigger marble chips are used in q.  d hydrochloric acid is more concentrated in q.      17 when pink cobalt( ii) sulfate crystals are heated, they form steam and a blue solid.    when water is added to the blue solid, it turns pink and becomes hot.    which terms describe the pink cobalt( ii) sulfate crystals and the reactions?     pink cobalt sulfate reactions  a aqueous irreversible  b aqueous reversible  c hydrated irreversible  d hydrated reversible     18 iron is extracted from iron oxide using carbon monoxide as shown in the equation.    iron oxide + carbon monoxide \u2192 iron + carbon dioxide    what does the equation show?  a carbon monoxide is oxidised to carbon dioxide.  b carbon monoxide is reduced to carbon dioxide.  c iron is oxidised to iron oxide.  d iron oxide is oxidised to iron.   ",
            "8": "8  \u00a9 ucles 2010 0620/11/m/j/10  19 aqueous sodium hydroxide is added to a solid, x, and the mixture is heated.    a green precipitate is formed and an alkaline gas is given off.    which ions are present in x?  a + 4nh  and fe2+  b + 4nh  and fe3+  c oh\u2013 and fe2+  d oh\u2013 and fe3+     20 an aqueous solution of the organic compound methylamine has a ph greater than 7.    which statement about methylamine is correct?  a it neutralises an aqueous solution of sodium hydroxide.  b it reacts with copper( ii) carbonate to give carbon dioxide.  c it reacts with hydrochloric acid to form a salt.  d it turns blue litmus red.      21 the positions in the periodic table of four elements are shown.    which element is most  likely to form an acidic oxide?    a b c d      ",
            "9": "9  \u00a9 ucles 2010 0620/11/m/j/10 [turn over  22 an excess of copper( ii) oxide is added to dilute sulfuric acid to make crystals of hydrated  copper( ii) sulfate.    the processes listed may be used to obtain crystals of hydrated copper( ii) sulfate.    1 concentrate the resulting solution  2 filter  3 heat the crystals  4 wash the crystals    which processes are needed and in which order?  a 1, 2, 3 and 4  b 1, 2, 4 and 3  c 2, 1, 2 and 3  d 2, 1, 2 and 4      23 which is not a property of group i metals?  a they are soft and can be cut with a knife.  b they corrode rapidly when exposed to oxygen in the air.  c they produce an acidic solution when they react with water.  d they react rapidly with water producing hydrogen gas.     24 an element melts at 1455  \u00b0c, has a density of 8.90  g / cm3 and forms a green chloride.    where in the periodic table is this element found?    cb da      ",
            "10": "10  \u00a9 ucles 2010 0620/11/m/j/10  25 an element does not conduct electricity and exists as diatomic molecules.    in which area of the periodic table is the element to be found?    bac d      26 solutions of a halogen and a sodium halide are mixed.    which mixture darkens in colour because a reaction occurs?  a bromine and sodium chloride  b bromine and sodium fluoride  c chlorine and sodium fluoride  d chlorine and sodium iodide      27 copper, iron and zinc are all used as pure metals.    which of these three metals are also used in alloys?     copper iron zinc  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0017 \u0013     28 some properties of four elements are shown in the table.    which element is a metal?     melting point  / \u00b0c electrical conductivity  when liquid electrical conductivity  when solid  a \u20137 low low  b 801 high low  c 1535 high high  d 3550 low low   ",
            "11": "11  \u00a9 ucles 2010 0620/11/m/j/10 [turn over  29 a student added dilute hydrochloric acid to four metals and recorded the results.     not all of the results are correct.    results    metal gas given off  1 copper yes  2 iron yes  3 magnesium no  4 zinc yes    which two results are correct?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     30 the diagram shows the manufacture of steel.    waste gasesgas x molten iron     what is gas x?  a carbon dioxide  b chlorine  c hydrogen  d oxygen     ",
            "12": "12  \u00a9 ucles 2010 0620/11/m/j/10  31 aluminium is an important metal with many uses.    some of its properties are listed.    1 it is a good conductor of heat.  2 it is a reactive metal.  3 it has a low density.  4 it has an oxide layer that prevents corrosion.    which set of properties help to explain the use of aluminium for cooking and storing food?  a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4     32 which statements about water are correct?    1 water is treated with chlorine to kill bacteria.  2 household water may contain salts in solution. 3 water is used in industry for cooling. 4 water for household use is filtered to remove soluble impurities.    a 1, 2 and 3 b 1 and 4 c 2, 3 and 4 d 1, 2, 3 and 4     33 which compound in polluted air can damage stonework and kill trees?  a carbon dioxide  b carbon monoxide  c lead compounds  d sulfur dioxide     34 which statement about methane is not correct?  a it is a liquid produced by distilling petroleum.  b it is produced as vegetation decomposes.  c it is produced by animals such as cows.  d it is used as a fuel.    ",
            "13": "13  \u00a9 ucles 2010 0620/11/m/j/10 [turn over  35 to grow roses, a fertiliser containing nitrogen, phosphorus and potassium is needed.    for the best flowers, the fertiliser should contain a high proportion of potassium.    which fertiliser is best for roses?    proportion by mass  fertiliser  n p k  a 9 0 25  b 13 13 20  c 29 5 0  d 29 15 5      36 the diagram shows three types of item.    cutlery cooking paninstruments used in hospitals    which method of rust prevention can be used for all three types of item?  a coating with plastic  b covering with grease  c galvanising  d using stainless steel     37 which structure is incorrect ?    hhh hhh ccca hhhhhh cc b hhoho cc hd hhhho cc hh      ",
            "14": "14  \u00a9 ucles 2010 0620/11/m/j/10  38 which structure shows a compound that belongs to a different  homologous series to propane?    ab c d cch hhh hch hh hchhh c c chhhhhh hchhh c c ch hh hhh h h h     39 a macromolecule is a very large molecule.    macromolecules can be made by joining smaller molecules together. this is called polymerisation.    which row in the table describes the formation of a polymer?     monomer polymer  a ethane poly(ethane)  b ethene poly(ethene)  c ethane poly(ethene)  d ethene poly(ethane)     40 diesel, petrol and bitumen are all  a fuels.  b hydrocarbons.  c lubricants.  d waxes.   ",
            "15": "15   0620/11/m/j/10  blank page     ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.     0620/11/m/j/10   group  140  ce  cerium  58 141  pr  praseodymium  59 144  nd  neodymium  60 pm  promethium  61 150  sm  samarium  62 152  eu  europium  63 157  gd  gadolinium  64 159  tb  t erbiu m  65 162  dy  dysprosium  66 165  ho  holmium  67 167  er  erbium  68 169  tm  thulium  69 173  yb  ytterbium  70 175  lu  lutetium  71  232  th  thorium  90 pa  protactinium  91 238  u  uranium  92 np  neptunium  93 pu  plutonium  94 am  americium  95 cm  curium  96 bk  berkelium  97 cf  californium  98 es  einsteinium  99 fm  fermium  100 md  mendelevium  101 no  nobelium  102 lr  lawrencium  103 1  h  hydrogen  1  7  li  lithium  3  23  na  sodium  1 1 24  mg  magnesium  12  40  ca  calcium  20 45  sc  scandium  21 48  t i  t itaniu m  22 51  v  v anadiu m  23 52  cr  chromium  24 55  mn  manganese  25 56  fe  iron  26 59  co  cobalt  27 59  ni  nickel  28 64  cu  copper  29 65  zn  zinc  30 70  ga gallium  31 27  a l  aluminium  13 1 1  b  boron  5 12  c  carbon  6 14  n  nitrogen  7 16  o  oxygen  8 19  f  fluorine  9  28  si  silicon  14 31  p  phosphorus  15 32  s  sulfur  16 35.5  c l  chlorine  17 40  ar  argon  18 20  ne  neon  10 4  he  helium  2  73  ge  germanium  32 75  as  arsenic  33 79  se  selenium  34 80  br  bromine  35 84  kr  krypton  36 39  k  potassium  19  88  sr  strontium  38 89  y  yttrium  39 91  zr  zirconium  40 93  nb  niobium  41 96  mo  molybdenum  42 t c  t echnetiu m  43 101  ru  ruthenium  44 103  rh  rhodium  45 106  pd  palladium  46 108  ag  silver  47 1 1 2  cd  cadmium  48 1 1 5  in indium  49 1 1 9  sn  t i n  50 122  sb  antimony  51 128  t e  t elluriu m  52 127  i iodine  53 131  xe  xenon  54  137  ba  barium  56 139  la  lanthanum  57         * 178  hf  hafnium  72 181  t a  t antalu m  73 184  w  t ungste n  74 186  re  rhenium  75 190  os  osmium  76 192  ir  iridium  77 195  pt  platinum  78 197  au  gold  79 201  hg  mercury  80 204  t l  thallium  81 207  pb  lead  82 209  bi  bismuth  83 po  polonium  84 at  astatine  85 rn  radon  86  fr  francium  87 227  ac  actinium  89 9  be  beryllium  4 i ii iii iv v vi vii 0  85  rb  rubidium  37  133  cs  caesium  55  226  ra  radium  88  the volume of one mole of an y gas is 2 4 dm 3 at room temperature and pressure ( r .t.p.) . a  x  b a = relative atomic mass  x  = atomic symbol  b = proton (atomic) number key * 58-71 lanthanoid series  90-103 actinoid series d a t a  shee t  the periodic  t able of the element s   "
        },
        "0620_s10_qp_12.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib10 06_0620_12/rp  \u00a9 ucles 2010  [turn over       *8778752636* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  may/june 2010       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2010 0620/12/m/j/10  1 the diagram shows a cup of tea.        which row describes the water particles in the air above the cup compared with the water  particles in the cup?     moving faster closer together  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     2 which row shows the change that takes place when element x gains the new particle shown?     particle gained change  a electron an isotope of element x is formed  b electron the element one place to the right of x in the periodic table is formed  c proton an isotope of element x is formed  d proton the element one place to the right of x in the periodic table is formed     3 the symbols of two atoms may be written as shown.    x52 23 y52 24    which statement about these atoms is correct?  a they are different elements because they have different numbers of neutrons.  b they are different elements because they have different numbers of protons.  c they are isotopes of the same element because they have the same nucleon number.  d they are isotopes of the same element because they have the same proton number.     ",
            "3": "3  \u00a9 ucles 2010 0620/12/m/j/10 [turn over  4 the diagram shows an atom.    ee eeelectron nucleus containing nine particlesekey     what is the proton number and neutron number of the atom?     proton  number neutron  number  a 4 5  b 4 9  c 5 4  d 5 9      5 a fruit drink coloured orange contains a dissolved mixture of red and yellow colouring agents.  one of these colouring agents is suspected of being illegal.    which method could be used to show the presence of this illegal colouring agent?  a chromatography  b distillation  c evaporation  d filtration     6 a student carries out an experiment to find how fast 3  cm pieces of magnesium ribbon dissolve in  10  cm3 samples of sulfuric acid at different temperatures.    which piece of apparatus does the student not need?  a balance  b measuring cylinder  c stop-clock  d thermometer    ",
            "4": "4  \u00a9 ucles 2010 0620/12/m/j/10  7 three electrolysis cells are set up. each cell has inert electrodes.     the electrolytes are listed below.    cell 1 aqueous sodium chloride  cell 2 concentrated hydrochloric acid cell 3 molten lead( ii) bromide    in which cells is a gas formed at both  electrodes?  a 1 and 2 b 1 and 3 c 2 only d 3 only     8 the diagram shows apparatus for plating a spoon with silver.    spoon metal electrode electrolyte    which statement is not correct?  a silver would stick to the spoon because it is a very reactive metal.  b the electrolyte would be a silver salt dissolved in water.  c the metal electrode would be made from silver.  d the spoon would be connected to the negative of the power supply.      9 aqueous copper( ii) sulfate solution is electrolysed using inert electrodes.    copper( ii) ions (cu2+), hydrogen ions (h+), hydroxide ions (oh\u2013) and sulfate ions (\u22122 4so ) are  present in the solution.    to which electrodes are the ions attracted during this electrolysis?     attracted to anode attracted to cathode  a cu2+ and h+ oh\u2013 and \u22122 4so   b cu2+ and \u22122 4so  h+ and oh\u2013  c h+ and oh\u2013 cu2+ and \u22122 4so   d oh\u2013 and \u22122 4so  cu2+ and h+     ",
            "5": "5  \u00a9 ucles 2010 0620/12/m/j/10 [turn over  10 in which compounds are pairs of electrons shared between atoms?    1 sodium chloride  2 methane 3 lead bromide    a 1 only b 2 only c 1 and 3 d 1, 2 and 3      11 element x has six electrons in its outer shell.    = electronkey e eee eee     how could the element react?  a by gaining two electrons to form a positive ion  b by losing six electrons to form a negative ion  c by sharing two electrons with two electrons from another element to form two covalent bonds  d by sharing two electrons with two electrons from another element to form four covalent bonds      12 hydrogen and chlorine react as shown.    1 molecule  of hydrogen + 1 molecule of chlorine \u2192 2 molecules  of hydrogen chloride   what is the equation for this reaction?  a 2h + 2c l \u2192 2hc l  b 2h + 2c l \u2192 h2cl 2  c h 2 + c l 2 \u2192 2hc l  d h 2 + c l 2 \u2192 h2cl 2      13 which name is given to mixtures of metals?  a alloys  b compounds  c ores  d salts    ",
            "6": "6  \u00a9 ucles 2010 0620/12/m/j/10  14 iron is extracted from iron oxide using carbon monoxide as shown in the equation.    iron oxide + carbon monoxide \u2192 iron + carbon dioxide    what does the equation show?  a carbon monoxide is oxidised to carbon dioxide.  b carbon monoxide is reduced to carbon dioxide.  c iron is oxidised to iron oxide.  d iron oxide is oxidised to iron.      15 a student investigates the rate of reaction between marble chips and hydrochloric acid.    the loss in mass of the reaction flask is measured.     the graph shows the results of two experiments, p and q.    0mass of reaction flask timep q     which change explains the difference between p and q?  a a catalyst is added in p.  b a higher temperature is used in p.  c bigger marble chips are used in q.  d hydrochloric acid is more concentrated in q.     ",
            "7": "7  \u00a9 ucles 2010 0620/12/m/j/10 [turn over  16 clouds are formed when water vapour evaporates from the sea.    clouds seawater vapou r     what is the energy change and what name is given to the type of change when water  evaporates?     energy change type of change  a energy given out endothermic  b energy given out exothermic  c energy taken in endothermic  d energy taken in exothermic      17 which process is not exothermic?  a burning a fossil fuel  b obtaining lime from limestone  c radioactive decay of 235u  d reacting hydrogen with oxygen     18 when pink cobalt( ii) sulfate crystals are heated, they form steam and a blue solid.    when water is added to the blue solid, it turns pink and becomes hot.    which terms describe the pink cobalt( ii) sulfate crystals and the reactions?     pink cobalt sulfate reactions  a aqueous irreversible  b aqueous reversible  c hydrated irreversible  d hydrated reversible    ",
            "8": "8  \u00a9 ucles 2010 0620/12/m/j/10  19 an element melts at 1455  \u00b0c, has a density of 8.90  g / cm3 and forms a green chloride.    where in the periodic table is this element found?    cb da       20 an excess of copper( ii) oxide is added to dilute sulfuric acid to make crystals of hydrated  copper( ii) sulfate.    the processes listed may be used to obtain crystals of hydrated copper( ii) sulfate.    1 concentrate the resulting solution  2 filter  3 heat the crystals  4 wash the crystals    which processes are needed and in which order?  a 1, 2, 3 and 4  b 1, 2, 4 and 3  c 2, 1, 2 and 3  d 2, 1, 2 and 4     21 which is not a property of group i metals?  a they are soft and can be cut with a knife.  b they corrode rapidly when exposed to oxygen in the air.  c they produce an acidic solution when they react with water.  d they react rapidly with water producing hydrogen gas.    ",
            "9": "9  \u00a9 ucles 2010 0620/12/m/j/10 [turn over  22 aqueous sodium hydroxide is added to a solid, x, and the mixture is heated.    a green precipitate is formed and an alkaline gas is given off.    which ions are present in x?  a + 4nh  and fe2+  b + 4nh  and fe3+  c oh\u2013 and fe2+  d oh\u2013 and fe3+     23 an aqueous solution of the organic compound methylamine has a ph greater than 7.    which statement about methylamine is correct?  a it neutralises an aqueous solution of sodium hydroxide.  b it reacts with copper( ii) carbonate to give carbon dioxide.  c it reacts with hydrochloric acid to form a salt.  d it turns blue litmus red.      24 the positions in the periodic table of four elements are shown.    which element is most  likely to form an acidic oxide?    a b c d      ",
            "10": "10  \u00a9 ucles 2010 0620/12/m/j/10  25 the diagram shows the manufacture of steel.    waste gasesgas x molten iron     what is gas x?  a carbon dioxide  b chlorine  c hydrogen  d oxygen      26 a student added dilute hydrochloric acid to four metals and recorded the results.     not all of the results are correct.    results    metal gas given off  1 copper yes  2 iron yes  3 magnesium no  4 zinc yes    which two results are correct?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "11": "11  \u00a9 ucles 2010 0620/12/m/j/10 [turn over  27 an element does not conduct electricity and exists as diatomic molecules.    in which area of the periodic table is the element to be found?    bac d      28 copper, iron and zinc are all used as pure metals.    which of these three metals are also used in alloys?     copper iron zinc  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0017 \u0013      29 solutions of a halogen and a sodium halide are mixed.    which mixture darkens in colour because a reaction occurs?  a bromine and sodium chloride  b bromine and sodium fluoride  c chlorine and sodium fluoride  d chlorine and sodium iodide     30 some properties of four elements are shown in the table.    which element is a metal?     melting point  / \u00b0c electrical conductivity  when liquid electrical conductivity  when solid  a \u20137 low low  b 801 high low  c 1535 high high  d 3550 low low   ",
            "12": "12  \u00a9 ucles 2010 0620/12/m/j/10  31 the diagram shows three types of item.    cutlery cooking paninstruments used in hospitals    which method of rust prevention can be used for all three types of item?  a coating with plastic  b covering with grease  c galvanising  d using stainless steel     32 aluminium is an important metal with many uses.    some of its properties are listed.    1 it is a good conductor of heat.  2 it is a reactive metal.  3 it has a low density.  4 it has an oxide layer that prevents corrosion.    which set of properties help to explain the use of aluminium for cooking and storing food?  a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4      33 to grow roses, a fertiliser containing nitrogen, phosphorus and potassium is needed.    for the best flowers, the fertiliser should contain a high proportion of potassium.    which fertiliser is best for roses?    proportion by mass  fertiliser  n p k  a 9 0 25  b 13 13 20  c 29 5 0  d 29 15 5    ",
            "13": "13  \u00a9 ucles 2010 0620/12/m/j/10 [turn over  34 which statements about water are correct?    1 water is treated with chlorine to kill bacteria.  2 household water may contain salts in solution.  3 water is used in industry for cooling.  4 water for household use is filtered to remove soluble impurities.    a 1, 2 and 3 b 1 and 4 c 2, 3 and 4 d 1, 2, 3 and 4      35 which statement about methane is not correct?  a it is a liquid produced by distilling petroleum.  b it is produced as vegetation decomposes.  c it is produced by animals such as cows.  d it is used as a fuel.      36 which compound in polluted air can damage stonework and kill trees?  a carbon dioxide  b carbon monoxide  c lead compounds  d sulfur dioxide      37 diesel, petrol and bitumen are all  a fuels.  b hydrocarbons.  c lubricants.  d waxes.     ",
            "14": "14  \u00a9 ucles 2010 0620/12/m/j/10  38 a macromolecule is a very large molecule.    macromolecules can be made by joining smaller molecules together. this is called  polymerisation.    which row in the table describes the formation of a polymer?     monomer polymer  a ethane poly(ethane)  b ethene poly(ethene)  c ethane poly(ethene)  d ethene poly(ethane)    39 which structure shows a compound that belongs to a different  homologous series to propane?    ab c d cch hhh hch hh hchhh c c chhhhhh hchhh c c ch hh hhh h h h      40 which structure is incorrect ?    hhh hhh ccca hhhhhh cc b hhoho cc hd hhhho cc hh    ",
            "15": "15  \u00a9 ucles 2010 0620/12/m/j/10  blank page      ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2010 0620/12/m/j/10   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s10_qp_13.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib10 06_0620_13/rp  \u00a9 ucles 2010  [turn over       *1150134 897* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  may/june 2010       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2010 0620/13/m/j/10  1 the diagram shows a cup of tea.        which row describes the water particles in the air above the cup compared with the water  particles in the cup?     moving faster closer together  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     2 which row shows the change that takes place when element x gains the new particle shown?     particle gained change  a electron an isotope of element x is formed  b electron the element one place to the right of x in the periodic table is formed  c proton an isotope of element x is formed  d proton the element one place to the right of x in the periodic table is formed     3 the symbols of two atoms may be written as shown.    x52 23 y52 24    which statement about these atoms is correct?  a they are different elements because they have different numbers of neutrons.  b they are different elements because they have different numbers of protons.  c they are isotopes of the same element because they have the same nucleon number.  d they are isotopes of the same element because they have the same proton number.     ",
            "3": "3  \u00a9 ucles 2010 0620/13/m/j/10 [turn over  4 the diagram shows an atom.    ee eeelectron nucleus containing nine particlesekey     what is the proton number and neutron number of the atom?     proton  number neutron  number  a 4 5  b 4 9  c 5 4  d 5 9      5 a fruit drink coloured orange contains a dissolved mixture of red and yellow colouring agents.  one of these colouring agents is suspected of being illegal.    which method could be used to show the presence of this illegal colouring agent?  a chromatography  b distillation  c evaporation  d filtration     6 a student carries out an experiment to find how fast 3  cm pieces of magnesium ribbon dissolve in  10  cm3 samples of sulfuric acid at different temperatures.    which piece of apparatus does the student not need?  a balance  b measuring cylinder  c stop-clock  d thermometer    ",
            "4": "4  \u00a9 ucles 2010 0620/13/m/j/10  7 three electrolysis cells are set up. each cell has inert electrodes.     the electrolytes are listed below.    cell 1 aqueous sodium chloride  cell 2 concentrated hydrochloric acid cell 3 molten lead( ii) bromide    in which cells is a gas formed at both  electrodes?  a 1 and 2 b 1 and 3 c 2 only d 3 only     8 the diagram shows apparatus for plating a spoon with silver.    spoon metal electrode electrolyte    which statement is not correct?  a silver would stick to the spoon because it is a very reactive metal.  b the electrolyte would be a silver salt dissolved in water.  c the metal electrode would be made from silver.  d the spoon would be connected to the negative of the power supply.      9 aqueous copper( ii) sulfate solution is electrolysed using inert electrodes.    copper( ii) ions (cu2+), hydrogen ions (h+), hydroxide ions (oh\u2013) and sulfate ions (\u22122 4so ) are  present in the solution.    to which electrodes are the ions attracted during this electrolysis?     attracted to anode attracted to cathode  a cu2+ and h+ oh\u2013 and \u22122 4so   b cu2+ and \u22122 4so  h+ and oh\u2013  c h+ and oh\u2013 cu2+ and \u22122 4so   d oh\u2013 and \u22122 4so  cu2+ and h+     ",
            "5": "5  \u00a9 ucles 2010 0620/13/m/j/10 [turn over  10 in which compounds are pairs of electrons shared between atoms?    1 sodium chloride  2 methane 3 lead bromide    a 1 only b 2 only c 1 and 3 d 1, 2 and 3      11 element x has six electrons in its outer shell.    = electronkey e eee eee     how could the element react?  a by gaining two electrons to form a positive ion  b by losing six electrons to form a negative ion  c by sharing two electrons with two electrons from another element to form two covalent bonds  d by sharing two electrons with two electrons from another element to form four covalent bonds      12 hydrogen and chlorine react as shown.    1 molecule  of hydrogen + 1 molecule of chlorine \u2192 2 molecules  of hydrogen chloride   what is the equation for this reaction?  a 2h + 2c l \u2192 2hc l  b 2h + 2c l \u2192 h2cl 2  c h 2 + c l 2 \u2192 2hc l  d h 2 + c l 2 \u2192 h2cl 2      13 which name is given to mixtures of metals?  a alloys  b compounds  c ores  d salts    ",
            "6": "6  \u00a9 ucles 2010 0620/13/m/j/10  14 iron is extracted from iron oxide using carbon monoxide as shown in the equation.    iron oxide + carbon monoxide \u2192 iron + carbon dioxide    what does the equation show?  a carbon monoxide is oxidised to carbon dioxide.  b carbon monoxide is reduced to carbon dioxide.  c iron is oxidised to iron oxide.  d iron oxide is oxidised to iron.      15 a student investigates the rate of reaction between marble chips and hydrochloric acid.    the loss in mass of the reaction flask is measured.     the graph shows the results of two experiments, p and q.    0mass of reaction flask timep q     which change explains the difference between p and q?  a a catalyst is added in p.  b a higher temperature is used in p.  c bigger marble chips are used in q.  d hydrochloric acid is more concentrated in q.     ",
            "7": "7  \u00a9 ucles 2010 0620/13/m/j/10 [turn over  16 clouds are formed when water vapour evaporates from the sea.    clouds seawater vapou r     what is the energy change and what name is given to the type of change when water  evaporates?     energy change type of change  a energy given out endothermic  b energy given out exothermic  c energy taken in endothermic  d energy taken in exothermic      17 which process is not exothermic?  a burning a fossil fuel  b obtaining lime from limestone  c radioactive decay of 235u  d reacting hydrogen with oxygen     18 when pink cobalt( ii) sulfate crystals are heated, they form steam and a blue solid.    when water is added to the blue solid, it turns pink and becomes hot.    which terms describe the pink cobalt( ii) sulfate crystals and the reactions?     pink cobalt sulfate reactions  a aqueous irreversible  b aqueous reversible  c hydrated irreversible  d hydrated reversible    ",
            "8": "8  \u00a9 ucles 2010 0620/13/m/j/10  19 an element melts at 1455  \u00b0c, has a density of 8.90  g / cm3 and forms a green chloride.    where in the periodic table is this element found?    cb da       20 an excess of copper( ii) oxide is added to dilute sulfuric acid to make crystals of hydrated  copper( ii) sulfate.    the processes listed may be used to obtain crystals of hydrated copper( ii) sulfate.    1 concentrate the resulting solution  2 filter  3 heat the crystals  4 wash the crystals    which processes are needed and in which order?  a 1, 2, 3 and 4  b 1, 2, 4 and 3  c 2, 1, 2 and 3  d 2, 1, 2 and 4     21 which is not a property of group i metals?  a they are soft and can be cut with a knife.  b they corrode rapidly when exposed to oxygen in the air.  c they produce an acidic solution when they react with water.  d they react rapidly with water producing hydrogen gas.    ",
            "9": "9  \u00a9 ucles 2010 0620/13/m/j/10 [turn over  22 aqueous sodium hydroxide is added to a solid, x, and the mixture is heated.    a green precipitate is formed and an alkaline gas is given off.    which ions are present in x?  a + 4nh  and fe2+  b + 4nh  and fe3+  c oh\u2013 and fe2+  d oh\u2013 and fe3+     23 an aqueous solution of the organic compound methylamine has a ph greater than 7.    which statement about methylamine is correct?  a it neutralises an aqueous solution of sodium hydroxide.  b it reacts with copper( ii) carbonate to give carbon dioxide.  c it reacts with hydrochloric acid to form a salt.  d it turns blue litmus red.      24 the positions in the periodic table of four elements are shown.    which element is most  likely to form an acidic oxide?    a b c d      ",
            "10": "10  \u00a9 ucles 2010 0620/13/m/j/10  25 the diagram shows the manufacture of steel.    waste gasesgas x molten iron     what is gas x?  a carbon dioxide  b chlorine  c hydrogen  d oxygen      26 a student added dilute hydrochloric acid to four metals and recorded the results.     not all of the results are correct.    results    metal gas given off  1 copper yes  2 iron yes  3 magnesium no  4 zinc yes    which two results are correct?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "11": "11  \u00a9 ucles 2010 0620/13/m/j/10 [turn over  27 an element does not conduct electricity and exists as diatomic molecules.    in which area of the periodic table is the element to be found?    bac d      28 copper, iron and zinc are all used as pure metals.    which of these three metals are also used in alloys?     copper iron zinc  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0017 \u0013      29 solutions of a halogen and a sodium halide are mixed.    which mixture darkens in colour because a reaction occurs?  a bromine and sodium chloride  b bromine and sodium fluoride  c chlorine and sodium fluoride  d chlorine and sodium iodide     30 some properties of four elements are shown in the table.    which element is a metal?     melting point  / \u00b0c electrical conductivity  when liquid electrical conductivity  when solid  a \u20137 low low  b 801 high low  c 1535 high high  d 3550 low low   ",
            "12": "12  \u00a9 ucles 2010 0620/13/m/j/10  31 the diagram shows three types of item.    cutlery cooking paninstruments used in hospitals    which method of rust prevention can be used for all three types of item?  a coating with plastic  b covering with grease  c galvanising  d using stainless steel     32 aluminium is an important metal with many uses.    some of its properties are listed.    1 it is a good conductor of heat.  2 it is a reactive metal.  3 it has a low density.  4 it has an oxide layer that prevents corrosion.    which set of properties help to explain the use of aluminium for cooking and storing food?  a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4      33 to grow roses, a fertiliser containing nitrogen, phosphorus and potassium is needed.    for the best flowers, the fertiliser should contain a high proportion of potassium.    which fertiliser is best for roses?    proportion by mass  fertiliser  n p k  a 9 0 25  b 13 13 20  c 29 5 0  d 29 15 5    ",
            "13": "13  \u00a9 ucles 2010 0620/13/m/j/10 [turn over  34 which statements about water are correct?    1 water is treated with chlorine to kill bacteria.  2 household water may contain salts in solution.  3 water is used in industry for cooling.  4 water for household use is filtered to remove soluble impurities.    a 1, 2 and 3 b 1 and 4 c 2, 3 and 4 d 1, 2, 3 and 4      35 which statement about methane is not correct?  a it is a liquid produced by distilling petroleum.  b it is produced as vegetation decomposes.  c it is produced by animals such as cows.  d it is used as a fuel.      36 which compound in polluted air can damage stonework and kill trees?  a carbon dioxide  b carbon monoxide  c lead compounds  d sulfur dioxide      37 diesel, petrol and bitumen are all  a fuels.  b hydrocarbons.  c lubricants.  d waxes.     ",
            "14": "14  \u00a9 ucles 2010 0620/13/m/j/10  38 a macromolecule is a very large molecule.    macromolecules can be made by joining smaller molecules together. this is called  polymerisation.    which row in the table describes the formation of a polymer?     monomer polymer  a ethane poly(ethane)  b ethene poly(ethene)  c ethane poly(ethene)  d ethene poly(ethane)    39 which structure shows a compound that belongs to a different  homologous series to propane?    ab c d cch hhh hch hh hchhh c c chhhhhh hchhh c c ch hh hhh h h h      40 which structure is incorrect ?    hhh hhh ccca hhhhhh cc b hhoho cc hd hhhho cc hh  ",
            "15": "15  \u00a9 ucles 2010 0620/13/m/j/10  blank page      ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2010 0620/13/m/j/10   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s10_qp_21.pdf": {
            "1": "for examiner\u2019s use 1 2 3 total4 5 6 7 8read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 may/june 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 16 printed pages. [turn overib10 06_0620_21/4rp\u00a9 ucles 2010 *6848373417*",
            "2": "2 0620/21/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  choose from the following list of gases to answer the questions.  ammonia carbon monoxide chlorine ethene methane  nitrogen nitrogen dioxide oxygen propane   each gas can be used once, more than once or not at all.  which gas  (a)  is a greenhouse gas produced by the decomposition of vegetation,  .. ... [1]  (b)  is an alkane,  .. ... [1]  (c)  reacts with sulfuric acid to form a salt,  .. ... [1]  (d)  makes up about 20% of the air,  .. ... [1]  (e)  is a halogen,  .. ... [1]  (f) is a hydrocarbon which decolourizes aqueous bromine?  .. ... [1] [total: 6]",
            "3": "3 0620/21/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  this question is about hydrogen and some compounds containing hydrogen.  (a) hydrogen is a gas at room temperature.   describe the arrangement and motion of the molecules in hydrogen gas.  arrangement .. ...  motion ... .. [2]  (b)  draw the electronic structure of a hydrogen molecule. [1]  (c)  the symbols for two isotopes of hydrogen are shown below. 1 1h31h  (i)  what do you understand by the term isotope ?  .. ..  ..  [1]  (ii)  complete the table to show the number of subatomic particles in these two isotopes of hydrogen. isotope 11h31h number of electrons number of neutrons number of protons [4]  (d)  when hydrogen burns, energy is given out.    state the name given to a reaction which gives out energy.  .. ... [1]",
            "4": "4 0620/21/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (e)  hydrochloric acid reacts both with metals and with metal carbonates.  (i)  a student observed the reaction of hydrochloric acid with four different metals.   the student used the same concentration of hydrochloric acid and the same mass  of metal in each experiment. metal observations cobalt dissolves very slowly and very few bubbles produced iron dissolves slowly and a few bubbles produced slowly magnesium dissolves very quickly and many bubbles produced very rapidly zinc dissolves quickly and many bubbles produced rapidly  use the information in the table to suggest the order of reactivity of these metals. most reactive least reactive [2]  (ii)  state the names of the three  products formed when hydrochloric acid reacts with  calcium carbonate.  .. ..  .. ..  ..  [3] [total: 14]",
            "5": "5 0620/21/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use3  some pink cobalt chloride was heated gently in a test-tube.   the cobalt chloride turned blue.   a few drops of water were then added to the blue cobalt chloride.   the cobalt chloride turned pink. water blue cobalt chloride pink cobalt chloride  heat   (a) (i)  state the name of this type of reaction.  ..  [1]  (ii)  complete the following sentence. use words from the list below.  alkaline chloride dehydrated hydrated water   when  cobalt chloride is heated, it loses its  of crystallisation and changes colour. [2]  (b)  cobalt is a metal.  (i)  state two physical properties which are characteristic of metals.  .. ..  ..  [2]  (ii)  from its position in the periodic table predict two physical properties of cobalt in  addition to its general metallic properties.  .. ..  ..  [2]  (c)  cobalt( ii) oxide is a basic oxide.   predict one chemical property of cobalt( ii) oxide.  .. ... [1] [total: 8]",
            "6": "6 0620/21/m/j/10 \u00a9 ucles 2010for examiner\u2019s use4  the table shows the mass of various compounds obtained when 500  cm3 of seawater is  evaporated. compound ions present mass of compound  / g sodium chloride na+ and c l \u201314.0 magnesium chloride mg2+ and c l \u20133.0 magnesium sulfate mg2+ and so42\u20132.0 calcium sulfate ca2+ and so42\u20130.5 potassium chloride k+ and c l \u2013 0.5potassium bromide calcium carbonate ca2+ and co32\u2013 sodium iodide na+ and i \u2013 total mass = 20.0  (a)  which negative ion is present in seawater in the highest concentration?  .. ... [1]  (b)  write the symbols for the two ions present in potassium bromide.  ... and ..  [1]  (c)  calculate the mass of sodium chloride present in 5  g of the solid left by evaporating the  seawater. [1]  (d)  describe a test for iodide ions.  test . ...  result ...  [2]",
            "7": "7 0620/21/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (e)   aqueous chlorine reacts with aqueous sodium iodide.  (i)  complete the equation for this reaction. cl 2    +    2na i    \u2192    ...    +    2nac l [1]  (ii)  what colour is the solution when the reaction is complete?  ..  [1]  (iii)  an aqueous solution of iodine does not react with aqueous potassium bromide.  explain why there is no reaction.  ..  [1]  (f)  calculate the relative formula mass of magnesium chloride, mgc l 2.  .. ... [1] [total: 9]",
            "8": "8 0620/21/m/j/10 \u00a9 ucles 2010for examiner\u2019s use5  ammonium sulfate is used in fertilisers.  (a)  state the names of the three elements found in most fertilisers.  1.   2.  3.  [3] (b)  suggest why farmers use fertilisers.  .. .  .. ... [2]  (c)  ammonium sulfate is a salt which is soluble in water.  (i)  what do you understand by the term soluble ?  ..  [1]  (ii)  which of the following methods is used to make this salt in the laboratory?  tick one box.  adding an acid to a metal adding an acid to a metal oxide by a precipitation reaction by the titration of an acid with an alkali [1]  (d)  a mixture of ammonium sulfate and sodium hydroxide was warmed in a test-tube.   a gas was given off which turned red litmus paper blue.   state the name of this gas.  .. ... [1]",
            "9": "9 0620/21/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (e)   fertilisers containing ammonium salts are often slightly acidic.  (i)  state the name of a compound which farmers add to the soil to make it less acidic.  ..  [1]  (ii)  explain why it is important for farmers to control the acidity of the soil.  .. ..  ..  [2]  (f)  the formula of ammonium sulfate is (nh4)2so4.  in this formula state:  (i)  the number of different types of atoms present, ... [1]  (ii)  the total number of atoms present. ... [1] [total: 13]",
            "10": "10 0620/21/m/j/10 \u00a9 ucles 2010for examiner\u2019s use6  many metals are extracted from their ores by reduction with carbon.  (a)  name the main ore of iron.  .. ... [1]  (b)  iron is extracted from its ore in a blast furnace.  (i)  other than iron ore, state the names of two other raw materials used in the extraction  of iron.  1. ... 2. ... [2] (ii)  one of the reactions taking place in the blast furnace is feo   +   c   \u2192   fe   +   co   write a word equation for this reaction.  ..  [2]  (iii)  the diagram shows a blast furnace.  label the diagram to show each of the following:  \u25cf the slag,  \u25cf where the molten iron collects,  \u25cf where air is blown into the furnace,  \u25cf where the iron ore is put into the furnace. mixture of iron ore and raw materials [4]",
            "11": "11 0620/21/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  zinc is extracted from an ore containing zinc sul \ufb01 de.  part of a zinc sul \ufb01 de structure is shown below. zn2+zn2+zn2+zn2+ zn2+s2\u2013 zn2+s2\u2013 zn2+s2\u2013 zn2+s2\u2013 s2\u2013s2\u2013s2\u2013s2\u2013  suggest the simplest formula for zinc sul \ufb01 de.  .. ... [1] [total: 10]",
            "12": "12 0620/21/m/j/10 \u00a9 ucles 2010for examiner\u2019s use7  petroleum is a mixture of hydrocarbons.   two of the processes carried out in an oil re \ufb01 nery are fractional distillation of petroleum and  cracking of hydrocarbon fractions.  (a)  which property of hydrocarbons is used to separate petroleum into fractions?  tick one box.  boiling point chemical reactivity electrical conductivity melting point [1]  (b)  match the fractions on the left with their uses on the right.   the \ufb01 rst one has been done for you. fuel for home heating making roads waxes and polishes making chemicals jet fuelbitumen fuel oil kerosene lubricating fraction naphtha [4]",
            "13": "13 0620/21/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  cracking is used to break down long chained alkanes into shorter chained alkanes and  alkenes.  (i)  state two conditions needed for cracking.  1. ... .  2. .. [2]  (ii)  the hydrocarbon, c14h30, can be cracked to make ethene and one other  hydrocarbon.   complete the equation for this reaction. c14h30   \u2192   c2h4   +   ... [1]  (iii)  draw the full structure of ethene showing all atoms and bonds. [1]  (d)  state the name of the polymer formed from ethene.  .. ... [1]  (e)  ethene is used to make ethanol.  (i)  which substance is needed for this reaction?  put a ring around the correct answer.  ammonia hydrogen oxygen steam [1]  (ii)  phosphoric acid is a catalyst in this reaction.  what do you understand by the term catalyst ?  .. ..  ..  [1] [total: 12]",
            "14": "14 0620/21/m/j/10 \u00a9 ucles 2010for examiner\u2019s use8  some substances conduct electricity, others do not.  (a)  which three of the following conduct electricity?   tick three  boxes.  aqueous sodium chloride  ceramics copper graphite sodium chloride crystals sulfur [3]  (b)  state the name given to a substance, such as plastic, which does not conduct  electricity.  .. ... [1]  (c)  molten zinc chloride was electrolysed using the apparatus shown below. + \u2013  positive  electrode negative  electrode  molten zincchloride  (i)  choose a word from the list below which describes the positive electrode.  put a ring around the correct answer.  anion anode cathode cation [1]",
            "15": "15 0620/21/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  state the name of the product formed during this electrolysis at  the negative electrode,  . .  the positive electrode.  . [2] (iii)  suggest the name of a non-metal which can be used for the electrodes in this  electrolysis.  ..  [1] [total: 8]",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/21/m/j/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s10_qp_22.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 may/june 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib10 06_0620_22/4rp\u00a9 ucles 2010 *7783817036* for examiner\u2019s use 1 2 3 total4 5 6 7 8",
            "2": "2 0620/22/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  the diagram shows part of the periodic table.   only some of the elements are shown. li na kmg ca ti zrv nb  (a)  answer the following questions by choosing only from the elements shown in the  diagram.   you can use each element once, more than once or not at all.  (i)  state the names of two transition elements shown in the diagram.  ..  and  . [2] (ii)  state the name of an element which is in period 3 of the periodic table.  ..  [1]  (iii)  which element has the electronic structure 2,8,1?  ..  [1]  (iv)  which element has the fastest reaction with water?  ..  [1]  (v)  which element has 23 protons in its nucleus?  ..  [1]  (b)  sodium reacts with oxygen to form sodium peroxide, na 2o2.   complete the symbol equation for this reaction. ... na  +  ...   \u2192   na2o2 [2] [total: 8]",
            "3": "3 0620/22/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  the list describes \ufb01 ve types of chemical structures.  giant covalent  giant ionic metallic simple atomic  simple molecular  (a)  the diagrams below show four types of chemical structures. i\u2013k+ i\u2013k+i\u2013 i\u2013k+ k+i\u2013k+ i\u2013k+i\u2013 i\u2013k+arar arclcl clcl clclcl clznznznznzn znznznznznznznznzn ar ark+abc d  (i)  use the list to match these structures with the diagrams.  structure a is  [1]  structure b is  [1]  structure c is  [1]  structure d is  [1]  (ii)  which two of the structures a, b, c or d have low melting points?  ..  and  . [1] (b)  sodium chloride is an ionic solid.   complete the following sentences using words from the list.  electrons ionic molecular molten solid  sodium chloride does not conduct electricity when it is a .  because the ions cannot move. when it is ... sodium chloride does  conduct electricity because the ions are free to move. [2] [total: 7]",
            "4": "4 0620/22/m/j/10 \u00a9 ucles 2010for examiner\u2019s use3  water is an important raw material in industry.  (a)  state one use of water in industry.  .. ... [1]  (b)  describe a chemical test for water.  test . ...  result ...  [2]  (c)  a small piece of potassium was placed in a beaker of water.  the equation for the reaction is 2k(s)  +  2h2o(l)  \u2192  2koh(aq)  +  h2(g)  (i)  describe a test for the gas given off in this reaction.  test .   result  [2 ]  (ii)  what is the most likely ph of the solution in the beaker when the reaction is  complete?  put a ring around the correct answer.  ph2 ph6 ph7 ph8 ph12 [1]  (d)  water is formed when propane burns.  (i)  complete the equation for this reaction. c3h8  +  5o2  \u2192  ...co2  +  ... h2o [2]  (ii)  which of the following best describes this reaction?  put a ring around the correct answer.  carbonisation combustion dehydration hydrogenation [1]  (iii)   when 4.4  g of propane are burnt in excess oxygen, 7.2  g of water are formed.   calculate the mass of water formed when 22  g of propane are burnt. [1] [total: 10]",
            "5": "5 0620/22/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use4  a student half- \ufb01 lled a syringe with water.   she then carefully drew up some blue ink into the syringe so that it formed a separate layer  below the water.   she then left the syringe in a clamp for twenty hours. water water ink inkwaterclamp   after twenty hours the blue colour of the ink had spread throughout the water.  (a)  use the kinetic particle theory to explain these observations.  .. .  .. .  .. ... [2]  (b)  ink is a mixture of many chemicals.  what do you understand by the term mixture ?  .. .  .. ... [1]  (c)  the list shows some of the substances present in ink.  carboxylic acids  cobalt( ii) ions  ethanol iron( ii) ions  nickel( ii) ions  tannins water  (i)  water is a good solvent.   from the list choose one other substance that is a good solvent.  ..  [1]",
            "6": "6 0620/22/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  what is the meaning of the symbol ( ii) in iron( ii)?  tick one box.  the number of outer shell electrons the difference between the  neutron and proton number  the oxidation state the type of isotope [1]  (iii)  tannins are polymers.  what do you understand by the term polymer ?  .. ..  ..  [2]  (d)  one of the carboxylic acids present in ink is gallic acid.  the structure of gallic acid is shown below. ho oh ohoh o c  (i)  on the structure above, put a ring around the carboxylic acid functional group. [1]  (ii)  gallic acid is a good reducing agent.  what do you understand by the term reduction ?  ..  [1] [total: 9]",
            "7": "7 0620/22/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  a student wants to separate the coloured pigments in a plant leaf by chromatography.  he grinds the plant leaf and separates the solids from the green solution.  (a)  what method can he use to separate the solids from the solution?  .. ... [1]  (b)  the student takes a drop of the green solution and puts a spot of it onto a piece of  chromatography paper.   from the diagrams below choose the letter for the most suitable piece of apparatus for  this task. abcd  letter . [1]  (c)  the student sets up the chromatography apparatus as shown.  (i)  label the diagram to show:  \u25cf the solvent,  \u25cf the original position of the spot of green solution,  \u25cf the chromatography paper. [3]  (ii)  how many different pigments were present in the plant leaf?  ..  [1]",
            "8": "8 0620/22/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (d)  the structure of some organic compounds found in plant leaves are shown below. cch hhh cco h hh o hcch hh co ohh hab c cch hh oh hhd  (i)  which one of these compounds is an unsaturated hydrocarbon?  . [1]  (ii)  describe a chemical test for an unsaturated hydrocarbon.  test .   result  [2 ]  (iii)  what do you understand by the term hydrocarbon ?  ..  [1]  (iv)  state the name of compound b.  ..  [1]  (v)  to which homologous series does compound d belong?  . [1] [total: 12]",
            "9": "9 0620/22/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use6  lead is a grey metal.  (a)  state two physical properties which are characteristic of metals.  .. .  .. ... [2]  (b)  to which group in the periodic table does lead belong?  .. ... [1]  (c)  an isotope of lead has the mass number 208.   complete the table to show the number of subatomic particles in an atom of this isotope  of lead.  use the periodic table to help you. type of particle number of particles electrons protons neutrons [3]  (d)  when lead is heated in oxygen, lead( ii) oxide is formed.  write a word equation for this reation.  .. ... [1]  (e)  when lead( ii) oxide is heated with carbon, lead and carbon monoxide are formed. pbo  +  c  \u2192  pb  +  co  (i)  which substance becomes oxidised during this reaction?  ..  [1]  (ii)   carbon monoxide is a covalent compound.  which one of these statements about carbon monoxide is correct? tick one box.  it is a solid with a high melting point. it conducts electricity when it is a liquid. it is a gas at room temperature. it forms about 1  % of the atmosphere. [1] [total: 9]",
            "10": "10 0620/22/m/j/10blank page",
            "11": "11 0620/22/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use7  three forms of carbon are diamond, graphite and buckminsterfullerene. diamond graphite buckminsterfullerenecarbon atom  (a)  (i)  state one difference in structure between buckminsterfullerene and diamond.  .. ..  ..  [1]  (ii)  state two differences in structure between graphite and diamond.  .. ..  .. ..  ..  [2]  (b)  state the type of bonding between the carbon atoms in diamond.  .. ... [1]  (c)  suggest why graphite is used as a lubricant.   refer to the layers in your answer.  .. .  .. ... [1]  (d)  state one use for diamond.  .. ... [1]",
            "12": "12 0620/22/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (e)  coal is a fuel containing carbon.    when coal is burnt, carbon dioxide is produced.   explain how the increase in carbon dioxide concentration in the atmopshere affects the  world\u2019s climate.  .. .  .. .  .. ... [2]  (f)  coal also contains small amounts of sulfur.   explain how burning coal leads to acid rain.  .. .  .. .  .. ... [2]  (g)  methane is a fuel.  (i)  which one of the following is a natural source of methane?  tick one box.  waste gases from respiration in plants waste gases from digestion in animals gases from photosynthesis in plants gases from forest \ufb01 res [1]",
            "13": "13 0620/22/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (ii)  draw a diagram to show the arrangement of the electrons in a molecule of methane,  ch4.  use  \u25cf for an electron from a carbon atom  \u00d7 for an electron from a hydrogen atom [1]  (iii)  methane belongs to the alkane homologous series.  name one other alkane.  ..  [1] [total: 13]",
            "14": "14 0620/22/m/j/10 \u00a9 ucles 2010for examiner\u2019s use8  the diagram shows a rotary kiln used to make lime from limestone.   limestone is fed in at the top of the kiln and lime comes out at the bottom. hot airair out limestone limekiln moves round  (a)  what is the chemical name for lime?  .. ... [1]  (b)  state the name of the type of chemical reaction that takes place in the rotary lime kiln.  .. ... [1]  (c)  suggest why the air coming out of the rotary kiln has a greater percentage of carbon  dioxide than the air entering the kiln.  .. ... [1]  (d)  state one use for lime.  .. ... [1]  (e)  a student compared the speed of reaction of three metal carbonates.   she measured the volume of gas released using the apparatus shown. metal carbonate heatgas syringe   state one thing that must be kept constant if the speeds of these reactions are to be  compared in a fair way.  .. ... [1]",
            "15": "15 0620/22/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (f)  the graph shows the volume of carbon dioxide released when the three metal carbonates  are heated. 02468 1 0 1 250 40302010 0 volume of carbon dioxide / cm3 time  / minutescalcium carbonate strontium carbonate barium carbonate  (i)  which carbonate produced carbon dioxide the fastest?  ..  [1]  (ii)  what volume of carbon dioxide was produced by strontium carbonate in ten  minutes?  ..  [1]  (iii)  how does the speed of the reaction of these three metal carbonates relate to the  position of calcium, strontium and barium in the periodic table?  .. ..  ..  [2]  (g)   describe how hydrochloric acid and limewater can be used to show that carbonate ions  are present in calcium carbonate.  .. .  .. .  .. ... [3] [total: 12]",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/22/m/j/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s10_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) may/june 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib10 06_0620_31/3rp\u00a9 ucles 2010 *3309238257* for examiner\u2019s use 3 4 5 total6 7 81 2",
            "2": "2 0620/31/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  choose an element which \ufb01 ts each of the following descriptions.  (i)  it is a yellow solid which burns to form an acidic oxide.  ..  [1]  (ii)  this element is a black solid which, when heated, forms a purple vapour.  ..  [1]  (iii)  most of its soluble salts are blue.  ..  [1]  (iv)  it has a basic oxide of the type mo which is used to treat acidic soils.  ..  [1]  (v)  it is an unreactive gas used to \ufb01 ll balloons.  ..  [1] [total: 5] 2  ozone is a form of oxygen. ozone is present in the upper atmosphere and it prevents  dangerous solar radiation from reaching the earth\u2019s surface. some of the chemicals that  diffuse into the upper atmosphere decompose ozone. chemicals that have this effect are methane (ch 4), chloromethane (ch3cl ) and an oxide of nitrogen (no2).  (i)  which of these three chemicals diffuses the most slowly? give a reason for your  choice.  .. ..  .. ..  ..  [2]  (ii)  chloromethane is formed when seaweed decomposes. name the compounds in the  environment from which seaweed might have obtained the following elements:  carbon; .. .  hydrogen; ...  chlorine.  [3] (iii)  how can chloromethane be made from methane?  reagent .. .  condition ... [2]",
            "3": "3 0620/31/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (iv) the oxides of nitrogen are atmospheric pollutants. describe how they are formed.  .. ..  .. ..  ..  [2]  (v)   complete the equation for the decomposition of ozone. ... o3  \u2192  ... [2] [total: 11]",
            "4": "4 0620/31/m/j/10 \u00a9 ucles 2010for examiner\u2019s use3  a diagram of the apparatus which could be used to investigate the rate of reaction between  magnesium and an excess of an acid is drawn below. 100  cm3 of acid 1.0  mol  / dm3 (excess)volume of hydrogen measured every 15 seconds small piece of magnesiumgraduated tubehydrogen collects  (a)  the magnesium kept rising to the surface. in one experiment, this was prevented by  twisting the magnesium around a piece of copper. in a second experiment, the magnesium was held down by a plastic net fastened to the beaker.  (i)  suggest a reason why magnesium, which is denser than water, \ufb02 oated to the  surface.  .. ..  ..  [1]  (ii)  iron, zinc and copper have similar densities. why was copper a better choice than  iron or zinc to weigh down the magnesium?  .. ..  ..  [1]  (b)  the only difference in the two experiments was the method used to hold down the  magnesium. the results are shown below. 00volume of h2 / cm3 time  / smagnesium held down by copper magnesium held down by plastic",
            "5": "5 0620/31/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (i)  in which experiment did the magnesium react faster?  ..  [1]  (ii)  suggest a reason why the experiment chosen in (i) had the faster rate.  ..  [1]  (c)  the experiment was repeated using 1.0  mol  / dm3 propanoic acid instead of 1.0  mol  / dm3  hydrochloric acid. propanoic acid is a weak acid.  (i)  how would the graph for propanoic acid differ  from the graph for hydrochloric  acid?  ..  [1]  (ii)  how would the graph for propanoic acid be the same  as the graph for hydrochloric  acid?  ..  [1]  (d)  give two factors which would alter the rate of this reaction.  for each factor explain why it alters the rate.  factor ... ..  explanation .. .  .. .  factor ... ..  explanation .. .  .. ... [4] [total: 10]",
            "6": "6 0620/31/m/j/10 \u00a9 ucles 2010for examiner\u2019s use4  hydrolysis is used in chemistry to break down complex molecules into simpler ones.  (a)  compounds containing the group                                             are esters.  (i)  give the names and formulae of the two compounds formed when the ester ethyl  propanoate is hydrolysed. ch2co och3 ch2ch3  name .. name ..  formula formula [4]  (ii)  fats are naturally occurring esters. they can be hydrolysed by boiling with aqueous  sodium hydroxide. c17h35cooch2 c17h35cooch2c17h35cooch +  3naoh  \u2192  3c17h35coona  + chohch2oh fatch2oh   what type of compound has the formula c17h35coona and what is its main use?  type of compound  [1] use ... [1 ]  (iii)  name a synthetic polyester.  ..  [1]co ro ocoo",
            "7": "7 0620/31/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (b)  the structure of a typical protein is drawn below. n c o h hn c o hn c o o hn c  (i)  what is the name of the polymer linkage?  ..  [1]  (ii)  draw the structural formula of a man-made polymer with the same linkage. [3]  (iii)  a protein can be hydrolysed to a mixture of amino acids which are colourless.  individual amino acids can be identi \ufb01 ed by chromatography. the rf value of the  amino acid glycine is 0.5. describe how you could show that glycine was present on a chromatogram.  .. ..  .. ..  ..  [3] [total: 14] 5  carbon and silicon are elements in group iv. both elements have macromolecular  structures.  (a)  diamond and graphite are two forms of the element carbon.  (i)  explain why diamond is a very hard substance.  .. ..  .. ..  ..  [2]  (ii)  give one use of diamond.  ..  [1]",
            "8": "8 0620/31/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (iii)  explain why graphite is a soft material.  .. ..  ..  [2]  (iv)  give one use of graphite.  . [1]  (b)  two of the oxides of these elements are carbon dioxide, co2, and silicon( iv) oxide,  sio2.  (i)  draw a diagram showing the arrangement of the valency electrons in one molecule  of the covalent compound carbon dioxide.  use x to represent an electron from a carbon atom. use o to represent an electron from an oxygen atom. [3]  (ii)  a section of the macromolecular structure of silicon( iv) oxide is given below. si oo o o   use this diagram to explain why the formula is sio2 not sio4.  .. ..  ..  [2]  (iii)  predict two differences in the physical properties of these two oxides.  .. ..  ..  [2] [total: 13]",
            "9": "9 0620/31/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use6  iodine reacts with chlorine to form dark brown iodine monochloride. i2  +  c l2  \u2192  2icl  this reacts with more chlorine to give yellow iodine trichloride.  there is an equilibrium between these iodine chlorides. icl (l)  +  c l2(g)    icl 3(s)  dark brown yellow  (a)  explain what is meant by equilibrium .  .. .  .. .  .. ... [2]  (b)  when the equilibrium mixture is heated it becomes a darker brown colour.  is the reverse reaction endothermic or exothermic? give a reason for your choice.  .. .  .. .  .. ... [2]  (c)  the pressure on the equilibrium mixture is decreased.  (i) how would this affect the position of equilibrium and why?  it would move to the . [1] reason ... .  ..  [1]  (ii)  describe what you would observe.  .. ..  ..  [1] [total: 7]",
            "10": "10 0620/31/m/j/10 \u00a9 ucles 2010for examiner\u2019s use7  titanium is a transition element. it is isolated by the following reactions. titanium ore \u2192 titanium( iv) oxide \u2192 titanium( iv) chloride \u2192 titanium  tio2 tic l 4 ti  (a)  why is it usually necessary to include a number in the name of the compounds of  transition elements?  .. ... [1]  (b)  titanium( iv) chloride is made by heating the oxide with coke and chlorine. tio2 + 2c l 2  tic l 4 + o2 2c + o2  2co  explain why the presence of coke ensures the maximum yield of the metal chloride. .. .  .. .  .. ... [2]  (c)  explain why the change, titanium( iv) chloride to titanium, is reduction.  .. .  .. ... [1]  (d)  complete the table which shows some of the properties of titanium and its uses.  the \ufb01 rst line has been completed as an example. property related use soluble in molten steel making steel titanium alloys  making aircraft and space vehiclesresistant to corrosion, especially in sea water ... [2]",
            "11": "11 0620/31/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (e)  the titanium ore contains 36.8% iron, 31.6% titanium and the remainder is oxygen.  (i)  determine the percentage of oxygen in this titanium compound.  percentage of oxygen = ... % [1] (ii)  calculate the number of moles of atoms for each element.  the number of moles of fe is shown as an example. number of moles of fe = 36.8  / 56 = 0.66  number of moles of ti = ... number of moles of o = . [1] (iii)  what is the simplest ratio for the moles of atoms? fe         :         ti         :         o  . . . [1]  (iv)  what is the formula of this titanium compound?  ..  [1] [total: 10]",
            "12": "12 0620/31/m/j/10 \u00a9 ucles 2010for examiner\u2019s use8  methanoic acid is the \ufb01 rst member of the homologous series of carboxylic acids.  (a)  give two general characteristics of a homologous series.  .. .  .. .  .. ... [2]  (b)  in some areas when water is boiled, the inside of kettles become coated with a layer of  calcium carbonate. this can be removed by adding methanoic acid.  (i)  complete the equation.  hcooh  +  caco3  \u2192  ca(hcoo)2  +  .  +  . [2]  (ii)  methanoic acid reacts with most metals above hydrogen in the reactivity series.  complete the word equation. zinc  +  methanoic acid  \u2192    +   [2]  (iii)  aluminium is also above hydrogen in the reactivity series.  why does methanoic acid not react with an aluminium kettle?  .. ..  ..  [1]  (c)  give the name, molecular formula and empirical formula of the fourth acid in this series.  name . .. [1]  molecular formula ... [1] empirical formula  [1] [total: 10]",
            "13": "13 0620/31/m/j/10blank page \u00a9 ucles 2010",
            "14": "14 0620/31/m/j/10blank page \u00a9 ucles 2010",
            "15": "15 0620/31/m/j/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/31/m/j/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s10_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) may/june 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib10 06_0620_32/2rp\u00a9 ucles 2010 *7667729700* for examiner\u2019s use 3 4 5 total6 7 81 2",
            "2": "2 0620/32/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  for each of the following unfamiliar elements predict one physical and one chemical  property.  (a) caesium (cs)  physical property  ... ...   chemical property  ... ..   ... ..  [2]  (b) vanadium (v)  physical property  ... ...   chemical property  ... ..   ... ..  [2]  (c) \ufb02 uorine (f)  physical property  ... ...   chemical property  ... ..   ... ..  [2] [total: 6] 2  the hydrolysis of complex carbohydrates to simple sugars is catalysed by enzymes called carbohydrases and also by dilute acids.  (a) (i)  they are both catalysts. how do enzymes differ from catalysts such as dilute acids?   . .  [1]  (ii)  explain why ethanol, c 2h6o, is not a carbohydrate but glucose, c6h12o6, is a  carbohydrate.   . ...   . .  [2]  (b)  draw the structure of a complex carbohydrate, such as starch. the formula of a simple  sugar can be represented by                              . [3]ho oh",
            "3": "3 0620/32/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  iodine reacts with starch to form a deep blue colour.  (i)  in the experiment illustrated below, samples are removed at intervals and tested  with iodine in potassium iodide solution. pipette toremove samples hot water aqueous starch anda few drops of saliva(saliva contains enzymes)   typical results of this experiment are shown in the table. time  / mincolour of sample tested with iodine  in potassium iodide solution 0 deep blue 10 pale blue30 colourless   explain these results.   . ...   . ...   . .  [3]  (ii)  if the experiment was repeated at a higher temperature, 60  \u00b0c, all the samples stayed  blue. suggest an explanation.   . .  [1] [total: 10]",
            "4": "4 0620/32/m/j/10 \u00a9 ucles 2010for examiner\u2019s use3  the following are examples of redox reactions.  (a)  bromine water was added to aqueous sodium sul \ufb01 de. br2(aq)  + s2\u2013(aq)  \u2192  2br  \u2013(aq)  +  s(s)  (i)  describe what you would observe when this reaction occurs.   . ...   . .  [2]  (ii)  write a symbol equation for this reaction.   . .  [1]  (iii)  explain, in terms of electron transfer, why bromine is the oxidant (oxidising agent) in  this reaction.   . ...   . .  [2]  (b)  iron and steel in the presence of water and oxygen form rust. fe2+ goes into solutionoxygen dissolvedin water electrons move in metalcolourlessgas forms  the reactions involved are:  reaction 1  fe  \u2192  fe2+  +  2e\u2013  the electrons move through the iron on to the surface where a colourless gas forms.  reaction 2  fe2+  +  2oh\u2013  \u2192  fe(oh)2  from water  reaction 3  ..fe(oh)2  +  o2  +  ..h2o  \u2192  ..fe(oh)3  the water evaporates to leave rust.",
            "5": "5 0620/32/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (i)   what type of reaction is reaction 1 ?  [1]  (ii)  deduce the name of the colourless gas mentioned in reaction 1 .   . .  [1]  (iii)  what is the name of the iron compound formed in reaction 2 ?   . .  [1]  (iv)  balance the equation for reaction 3 .  ..fe(oh)2  +  o2  +  ..h2o  \u2192  ..fe(oh)3 [1]  (v)  explain why the change fe(oh)2 to fe(oh)3 is oxidation.   . ...   . .  [1]  (vi)  explain why iron in electrical contact with a piece of zinc does not rust.   . ...   . ...   . .  [3] [total: 13] 4  but-1-ene is a typical alkene. it has the structural formula shown below. ch3ch2ch2ch  the structural formula of cyclobutane is given below. cc cch h h h hhhh  (a)  these two hydrocarbons are isomers.  (i)  de\ufb01 ne the term isomer .   . ...   . .  [2]",
            "6": "6 0620/32/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  draw the structural formula of another isomer of but-1-ene. [1]  (iii)  describe a test which would distinguish between but-1-ene and cyclobutane.  reagent  . .  result with but-1-ene  ..  . ...  result with cyclobutane  ..  . .  [3]  (b)  describe how alkenes, such as but-1-ene, can be made from alkanes.   ...    ... ..  [2]  (c)  name the product formed when but-1-ene reacts with:  bromine,  ..  [1]  hydrogen,    [1]  steam.  .. ...  [1] [total: 11]",
            "7": "7 0620/32/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  fuel cells are used in spacecraft to produce electrical energy. hydrogen oxygenanode electrolyte cathode  (a)  how is oxygen obtained from liquid air?  .. .  .. ...  [2]  (b)  hydrogen and oxygen react to form water. 2h2  + o2  \u2192  2h2o  (i)  give an example of bond breaking in the above reaction.  ..   [1]  (ii)  give an example of bond forming in the above reaction.  ..   [1]  (iii)  is the change given in (i) exothermic or endothermic?  ..   [1]  (c) (i)  give two reasons why hydrogen may be considered to be the ideal fuel for the  future.  .. ..  .. ..  ..   [2]  (ii)  suggest a reason why hydrogen is not widely used at the moment.  .. ..  ..   [1] [total: 8]",
            "8": "8 0620/32/m/j/10 \u00a9 ucles 2010for examiner\u2019s use6  thallium is a metal in group iii. it has oxidation states of +1 and +3.  (a)  give the formula for the following thallium compounds.  (i)  thallium( i) sul \ufb01 de .. [1]  (ii)  thallium( iii) chloride . [1]  (b)  thallium( i) chloride is insoluble in water. complete the description of the preparation of  a pure sample of this salt.  step 1   mix a solution of sodium chloride with thallium( i) sulfate solution. a white precipitate  forms.  step 2  .. ...  [1]  step 3  .. ...  [1]  step 4  .. ...  [1]  (c)  when thallium( i) chloride is exposed to light, a photochemical reaction occurs. it changes  from a white solid to a violet solid.  (i)  name another metal halide which changes colour when exposed to light. give the  major use of this metal halide.  name . .  use ...  [ 2]",
            "9": "9 0620/32/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (ii)  a piece of paper coated with thallium( i) chloride is exposed to a bright light. paper coated with thallium( i) chloride lamp  suggest two ways of increasing the time it takes for the violet colour to appear.  .. ..  .. ..  ..   [2]  (d)  thallium( i) hydroxide is an alkali. it has similar properties to sodium hydroxide.  (i)  complete the following word equation. thallium( i) hydroxideammonium sulfate..  ++ ..+ \u2192 [1]  (ii)  complete the equation.   t l oh  +  h2so4  \u2192  ..  +  .. [2]  (iii)  aqueous thallium( i) hydroxide was added to aqueous iron( ii) sulfate. describe what  you would see and complete the ionic equation for the reaction.  observation  ..   [1]  equation fe 2+  +  ... oh\u2013  \u2192   [1] [total: 14]",
            "10": "10 0620/32/m/j/10 \u00a9 ucles 2010for examiner\u2019s use7  aluminium was \ufb01 rst isolated in 1827 using sodium. al cl 3  +  3na  \u2192  a l  +  3nac l   aluminium, obtained by this method, was more expensive than gold.  (a)  suggest an explanation why aluminium was so expensive.  .. .  .. ...  [1]  (b)  the modern method for extracting aluminium is the electrolysis of a molten electrolyte,  aluminium oxide dissolved in cryolite. the aluminium oxide decomposes. 2a l 2o3  \u2192  4a l  + 3o2  both electrodes are made of carbon.  (i)  give two reasons why the oxide is dissolved in cryolite.  .. ..  .. ..  ..   [2]  (ii)  complete the ionic equation for the reaction at the anode. .. o2\u2013  \u2192  o2  +  . e\u2013 [2]  (iii)  why do the carbon anodes need to be replaced frequently?  .. ..  ..   [1]  (c)  the electrolysis of a molten electrolyte is one method of extracting a metal from its ore.  other methods are the electrolysis of an aqueous solution and the reduction of the oxide by carbon. explain why these last two methods cannot be used to extract aluminium.  electrolysis of an aqueous solution ... .. .  using carbon .   .. ...  [2] [total: 8]",
            "11": "11 0620/32/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use8  nitrogen dioxide is a brown gas. it can be made by heating certain metal nitrates. 2pb(no3)2  \u2192  2pbo  +  4no2  +  o2  (a) (i)   name another metal whose nitrate decomposes to give the metal oxide, nitrogen  dioxide and oxygen.  ..   [1]  (ii)  complete the word equation for a metal whose nitrate does not give nitrogen dioxide  on decomposition. metal nitrate  \u2192  .  +  oxygen [1]  (b)  at most temperatures, samples of nitrogen dioxide are equilibrium mixtures. 2no2(g)        n2o4(g)  dark brown pale yellow  (i)  at 25  \u00b0c, the mixture contains 20  % of nitrogen dioxide. at 100  \u00b0c this has risen to 90  %. is the forward reaction exothermic or endothermic?   give a reason for your choice.  .. ..  .. ..  ..   [2]  (ii)  explain why the colour of the equilibrium mixture becomes lighter when the pressure  on the mixture is increased.  .. ..  .. ..  ..   [2]",
            "12": "12 0620/32/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (c)  a 5.00  g sample of impure lead( ii) nitrate was heated. the volume of oxygen formed was  0.16  dm3 measured at r.t.p. the impurities did not decompose.   calculate the percentage of lead( ii) nitrate in the sample. 2pb(no3)2  \u2192  2pbo  +  4no2  + o2   number of moles of o2 formed = ...   number of moles of pb(no3)2 in the sample = ...  mass of one mole of pb(no3)2 = 331  g   mass of lead( ii) nitrate in the sample = ... g   percentage of lead( ii) nitrate in sample = . [4] [total: 10]",
            "13": "13 0620/32/m/j/10blank page \u00a9 ucles 2010",
            "14": "14 0620/32/m/j/10blank page \u00a9 ucles 2010",
            "15": "15 0620/32/m/j/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/32/m/j/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s10_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) may/june 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib10 06_0620_33/fp\u00a9 ucles 2010 *4049475364* for examiner\u2019s use 3 4 5 total6 7 81 2",
            "2": "2 0620/33/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  for each of the following unfamiliar elements predict one physical and one chemical  property.  (a) caesium (cs)  physical property  ... ...   chemical property  ... ..   ... ..  [2]  (b) vanadium (v)  physical property  ... ...   chemical property  ... ..   ... ..  [2]  (c) \ufb02 uorine (f)  physical property  ... ...   chemical property  ... ..   ... ..  [2] [total: 6] 2  the hydrolysis of complex carbohydrates to simple sugars is catalysed by enzymes called carbohydrases and also by dilute acids.  (a) (i)  they are both catalysts. how do enzymes differ from catalysts such as dilute acids?   . .  [1]  (ii)  explain why ethanol, c 2h6o, is not a carbohydrate but glucose, c6h12o6, is a  carbohydrate.   . ...   . .  [2]  (b)  draw the structure of a complex carbohydrate, such as starch. the formula of a simple  sugar can be represented by                              . [3]ho oh",
            "3": "3 0620/33/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  iodine reacts with starch to form a deep blue colour.  (i)  in the experiment illustrated below, samples are removed at intervals and tested  with iodine in potassium iodide solution. pipette toremove samples hot water aqueous starch anda few drops of saliva(saliva contains enzymes)   typical results of this experiment are shown in the table. time  / mincolour of sample tested with iodine  in potassium iodide solution 0 deep blue 10 pale blue30 colourless   explain these results.   . ...   . ...   . .  [3]  (ii)  if the experiment was repeated at a higher temperature, 60  \u00b0c, all the samples stayed  blue. suggest an explanation.   . .  [1] [total: 10]",
            "4": "4 0620/33/m/j/10 \u00a9 ucles 2010for examiner\u2019s use3  the following are examples of redox reactions.  (a)  bromine water was added to aqueous sodium sul \ufb01 de. br2(aq)  + s2\u2013(aq)  \u2192  2br  \u2013(aq)  +  s(s)  (i)  describe what you would observe when this reaction occurs.   . ...   . .  [2]  (ii)  write a symbol equation for this reaction.   . .  [1]  (iii)  explain, in terms of electron transfer, why bromine is the oxidant (oxidising agent) in  this reaction.   . ...   . .  [2]  (b)  iron and steel in the presence of water and oxygen form rust. fe2+ goes into solutionoxygen dissolvedin water electrons move in metalcolourlessgas forms  the reactions involved are:  reaction 1  fe  \u2192  fe2+  +  2e\u2013  the electrons move through the iron on to the surface where a colourless gas forms.  reaction 2  fe2+  +  2oh\u2013  \u2192  fe(oh)2  from water  reaction 3  ..fe(oh)2  +  o2  +  ..h2o  \u2192  ..fe(oh)3  the water evaporates to leave rust.",
            "5": "5 0620/33/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (i)   what type of reaction is reaction 1 ?  [1]  (ii)  deduce the name of the colourless gas mentioned in reaction 1 .   . .  [1]  (iii)  what is the name of the iron compound formed in reaction 2 ?   . .  [1]  (iv)  balance the equation for reaction 3 .  ..fe(oh)2  +  o2  +  ..h2o  \u2192  ..fe(oh)3 [1]  (v)  explain why the change fe(oh)2 to fe(oh)3 is oxidation.   . ...   . .  [1]  (vi)  explain why iron in electrical contact with a piece of zinc does not rust.   . ...   . ...   . .  [3] [total: 13] 4  but-1-ene is a typical alkene. it has the structural formula shown below. ch3ch2ch2ch  the structural formula of cyclobutane is given below. cc cch h h h hhhh  (a)  these two hydrocarbons are isomers.  (i)  de\ufb01 ne the term isomer .   . ...   . .  [2]",
            "6": "6 0620/33/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  draw the structural formula of another isomer of but-1-ene. [1]  (iii)  describe a test which would distinguish between but-1-ene and cyclobutane.  reagent  . .  result with but-1-ene  ..  . ...  result with cyclobutane  ..  . .  [3]  (b)  describe how alkenes, such as but-1-ene, can be made from alkanes.   ...    ... ..  [2]  (c)  name the product formed when but-1-ene reacts with:  bromine,  ..  [1]  hydrogen,    [1]  steam.  .. ...  [1] [total: 11]",
            "7": "7 0620/33/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  fuel cells are used in spacecraft to produce electrical energy. hydrogen oxygenanode electrolyte cathode  (a)  how is oxygen obtained from liquid air?  .. .  .. ...  [2]  (b)  hydrogen and oxygen react to form water. 2h2  + o2  \u2192  2h2o  (i)  give an example of bond breaking in the above reaction.  ..   [1]  (ii)  give an example of bond forming in the above reaction.  ..   [1]  (iii)  is the change given in (i) exothermic or endothermic?  ..   [1]  (c) (i)  give two reasons why hydrogen may be considered to be the ideal fuel for the  future.  .. ..  .. ..  ..   [2]  (ii)  suggest a reason why hydrogen is not widely used at the moment.  .. ..  ..   [1] [total: 8]",
            "8": "8 0620/33/m/j/10 \u00a9 ucles 2010for examiner\u2019s use6  thallium is a metal in group iii. it has oxidation states of +1 and +3.  (a)  give the formula for the following thallium compounds.  (i)  thallium( i) sul \ufb01 de .. [1]  (ii)  thallium( iii) chloride . [1]  (b)  thallium( i) chloride is insoluble in water. complete the description of the preparation of  a pure sample of this salt.  step 1   mix a solution of sodium chloride with thallium( i) sulfate solution. a white precipitate  forms.  step 2  .. ...  [1]  step 3  .. ...  [1]  step 4  .. ...  [1]  (c)  when thallium( i) chloride is exposed to light, a photochemical reaction occurs. it changes  from a white solid to a violet solid.  (i)  name another metal halide which changes colour when exposed to light. give the  major use of this metal halide.  name . .  use ...  [ 2]",
            "9": "9 0620/33/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (ii)  a piece of paper coated with thallium( i) chloride is exposed to a bright light. paper coated with thallium( i) chloride lamp  suggest two ways of increasing the time it takes for the violet colour to appear.  .. ..  .. ..  ..   [2]  (d)  thallium( i) hydroxide is an alkali. it has similar properties to sodium hydroxide.  (i)  complete the following word equation. thallium( i) hydroxideammonium sulfate..  ++ ..+ \u2192 [1]  (ii)  complete the equation.   t l oh  +  h2so4  \u2192  ..  +  .. [2]  (iii)  aqueous thallium( i) hydroxide was added to aqueous iron( ii) sulfate. describe what  you would see and complete the ionic equation for the reaction.  observation  ..   [1]  equation fe 2+  +  ... oh\u2013  \u2192   [1] [total: 14]",
            "10": "10 0620/33/m/j/10 \u00a9 ucles 2010for examiner\u2019s use7  aluminium was \ufb01 rst isolated in 1827 using sodium. al cl 3  +  3na  \u2192  a l  +  3nac l   aluminium, obtained by this method, was more expensive than gold.  (a)  suggest an explanation why aluminium was so expensive.  .. .  .. ...  [1]  (b)  the modern method for extracting aluminium is the electrolysis of a molten electrolyte,  aluminium oxide dissolved in cryolite. the aluminium oxide decomposes. 2a l 2o3  \u2192  4a l  + 3o2  both electrodes are made of carbon.  (i)  give two reasons why the oxide is dissolved in cryolite.  .. ..  .. ..  ..   [2]  (ii)  complete the ionic equation for the reaction at the anode. .. o2\u2013  \u2192  o2  +  . e\u2013 [2]  (iii)  why do the carbon anodes need to be replaced frequently?  .. ..  ..   [1]  (c)  the electrolysis of a molten electrolyte is one method of extracting a metal from its ore.  other methods are the electrolysis of an aqueous solution and the reduction of the oxide by carbon. explain why these last two methods cannot be used to extract aluminium.  electrolysis of an aqueous solution ... .. .  using carbon .   .. ...  [2] [total: 8]",
            "11": "11 0620/33/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use8  nitrogen dioxide is a brown gas. it can be made by heating certain metal nitrates. 2pb(no3)2  \u2192  2pbo  +  4no2  +  o2  (a) (i)   name another metal whose nitrate decomposes to give the metal oxide, nitrogen  dioxide and oxygen.  ..   [1]  (ii)  complete the word equation for a metal whose nitrate does not give nitrogen dioxide  on decomposition. metal nitrate  \u2192  .  +  oxygen [1]  (b)  at most temperatures, samples of nitrogen dioxide are equilibrium mixtures. 2no2(g)        n2o4(g)  dark brown pale yellow  (i)  at 25  \u00b0c, the mixture contains 20  % of nitrogen dioxide. at 100  \u00b0c this has risen to 90  %. is the forward reaction exothermic or endothermic?   give a reason for your choice.  .. ..  .. ..  ..   [2]  (ii)  explain why the colour of the equilibrium mixture becomes lighter when the pressure  on the mixture is increased.  .. ..  .. ..  ..   [2]",
            "12": "12 0620/33/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (c)  a 5.00  g sample of impure lead( ii) nitrate was heated. the volume of oxygen formed was  0.16  dm3 measured at r.t.p. the impurities did not decompose.   calculate the percentage of lead( ii) nitrate in the sample. 2pb(no3)2  \u2192  2pbo  +  4no2  + o2   number of moles of o2 formed = ...   number of moles of pb(no3)2 in the sample = ...  mass of one mole of pb(no3)2 = 331  g   mass of lead( ii) nitrate in the sample = ... g   percentage of lead( ii) nitrate in sample = . [4] [total: 10]",
            "13": "13 0620/33/m/j/10blank page \u00a9 ucles 2010",
            "14": "14 0620/33/m/j/10blank page \u00a9 ucles 2010",
            "15": "15 0620/33/m/j/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/33/m/j/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s10_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test may/june 2010  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 8 printed pages. [turn overib10 06_0620_51/5rp\u00a9 ucles 2010 *6086340837* for examiner\u2019s use total1 2",
            "2": "2 0620/51/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  you are going to investigate what happens when aqueous sodium hydroxide reacts with two  different acids c and d.   read all the instructions below carefully before starting the experiments.  instructions   you are going to carry out two experiments.   experiment 1   using a measuring cylinder, pour 20  cm3 of aqueous sodium hydroxide into the conical \ufb02 ask.  measure the temperature of the solution and record it in the table below.   add 6 drops of the indicator phenolphthalein to the \ufb02 ask.  fill the burette with acid c to the 0.0  cm3 mark.   add 5  cm3 of acid c to the sodium hydroxide, stirring with the thermometer. measure the  temperature of the mixture and record your result in the table below.   continue to add 5  cm3 portions of acid c to the \ufb02 ask, stirring with the thermometer until a total  volume of 30  cm3 of acid c has been added. measure and record the temperatures after each  5 cm3 portion has been added.   record the volume of acid c added when the indicator changes colour.   volume of acid c added to change the indicator colour   cm3 [1]  table of results volume of acid c added  / cm3temperature  / \u00b0c 0 5 1015202530 [3]",
            "3": "3 0620/51/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use  experiment 2   empty the burette and rinse it with water. add a small volume of acid d to the burette and use  it to rinse out the burette. fill the burette with acid d to the 0.0  cm3 mark.   using a measuring cylinder, pour 20  cm3 of aqueous sodium hydroxide into a clean conical  \ufb02 ask. measure the temperature of the solution and record it in the table.   add 6 drops of the indicator phenolphthalein to the \ufb02 ask.   add 5  cm3 of acid d to the sodium hydroxide, stirring with the thermometer. measure the  temperature of the mixture and record your result in the table below.   continue to add 5  cm3 portions of acid d to the \ufb02 ask, stirring with the thermometer until a total  volume of 30  cm3 of acid d has been added. measure and record the temperatures after each  5 cm3 portion has been added.   record the volume of acid d added when the indicator changes colour.   volume of acid d added to change the indicator colour   cm3 [1]  table of results volume of acid d added  / cm3temperature  / \u00b0c 0 5 1015202530 [3]",
            "4": "4 0620/51/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (a)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.  clearly label your graphs. 0 5 10 15 volume of acid added  / cm3temperature of mixture  / \u00b0c 20 25 3045 40353025 20 15 10 [6]  (b)  from your graph, deduce the temperature of the mixture when 3 cm3 of acid c reacts  with sodium hydroxide in experiment 1.   show clearly on the graph  how you worked out your answer.  ... \u00b0c [2]  (c)  when phenolphthalein indicator is used in these experiments, the colour changes from   to   . [1]",
            "5": "5 0620/51/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (d) (i)  in which experiment is the temperature change greater?  ..  [1]  (ii)  suggest why the temperature change is greater in this experiment.  .. ..  .. ..  ..  [2]  (e)  predict the temperature of the reaction mixture in experiment 2 after 1 hour. explain your  answer.  .. .  .. ... [2] [total: 22]",
            "6": "6 0620/51/m/j/10 \u00a9 ucles 2010for examiner\u2019s use2  you are provided with solid e.   carry out the following tests on e, recording all of your observations in the table.   conclusions must not be written in the table. tests observations (a)  describe the appearance of solid e.   [1] (b)   place half of solid e in a test-tube.   heat the test-tube gently.   test any gas given off with damp ph  indicator paper. .   [2] (c)  add the rest of solid e to about 8  cm3 of  distilled water in a test-tube.   cork the test-tube and shake the contents  until dissolved.   divide the solution into 4 equal portions in  test-tubes and carry out the following.  (i)  add several drops of aqueous sodium  hydroxide to the \ufb01 rst portion of the  solution and shake the test-tube.   now add excess sodium hydroxide to  the test-tube.  (ii)  repeat test (i) using aqueous  ammonia solution instead of aqueous sodium hydroxide.  (iii)  test the ph of the third portion of  the solution with indicator paper. now add to the solution about 1  cm3 of dilute hydrochloric acid  followed by about 1  cm3 of barium  chloride solution.  (iv)  to the fourth portion of the solution add  an equal volume of aqueous sodium hydroxide. now add a small spatula measure of aluminium powder and warm the mixture carefully . test any  gases given off. .  .  [3] .  [2]  ph .. [1]   [1]  .   [2]",
            "7": "7 0620/51/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (d)  what does test (c)(iii)  tell you about e?  .. .  .. ... [2]  (e)  identify the gas given off in test (c)(iv) .  .. ... [1]  (f)  what conclusions can you draw about solid e?  .. .  .. .  .. ... [3] [total: 18]",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/51/m/j/10notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2010"
        },
        "0620_s10_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test may/june 2010  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 8 printed pages. [turn overib10 06_0620_52/5rp\u00a9 ucles 2010 *7898557078* for examiner\u2019s use total1 2",
            "2": "2 0620/52/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  you are going to investigate the solubility of salt a in water at various temperatures.   read all the instructions below carefully before starting the experiments.  instructions  experiment 1   you are provided with a clean boiling tube containing 12  g of a.   fill the burette provided with distilled water and add 10.0  cm3 of water to the boiling tube.    heat the mixture of salt a and water carefully until all of the solid has dissolved.   you will have to boil the solution gently .   remove the boiling tube from the heat and allow the solution to cool.  stir the solution gently  with the thermometer.   note the temperature at which crystals \ufb01 rst appear  and record the temperature in the  table.   keep the boiling tube and its contents for the remaining experiments in this  question.  experiment 2   from the burette, add 2.0  cm3 more of the water into the boiling tube and contents from  experiment 1.   repeat the experiment exactly as before to \ufb01 nd the temperature at which crystals \ufb01 rst  appear .   it may help if the boiling tube is dipped for short  periods of time in a beaker of cold water to  speed up the cooling.   record, in the table, the total  volume of water in the boiling tube and the temperature at  which crystals \ufb01 rst appear.",
            "3": "3 0620/52/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use experiment 3   from the burette, add 2.0  cm3 more of the water into the boiling tube and contents from  experiment 2.   repeat the experiment exactly as before and record, in the table, the total volume of water  used and the temperature at which crystals \ufb01 rst appear.   continue this procedure for experiment 4  with one more addition of 2.0  cm3 of water. note all  the results in the table.   at the end of experiment 4, the total volume of water in the boiling tube will be 16.0  cm3.  table of results experiment total volume of water  / cm3 temperature at which crystals \ufb01 rst appear  / \u00b0c 1 10.0 234 [5]",
            "4": "4 0620/52/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (a)  plot your results on the grid below and draw a straight line graph.temperature at which crystals first appear  / \u00b0c total volume of water  / cm39 1 01 11 21 31 41 51 6 [6]",
            "5": "5 0620/52/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (b)  how did you know when salt a was completely dissolved in the water?  .. ... [1]  (c)  from your graph , \ufb01 nd the temperature at which crystals of a would \ufb01 rst appear if the  total volume of water in the solution were 9.0  cm3.   show clearly on the graph  how you worked out your answer.  ... \u00b0c [2]  (d)  salt b is more soluble in water than salt a. sketch on the grid the graph you would  expect for b. label this graph. [2]  (e)  suggest, with a reason, how the results would be different if 6  g of salt a were used  instead of 12  g.  .. .  .. ... [2]  (f)  explain one improvement you could make to the experimental procedure to obtain more  accurate results in this investigation.  improvement .. ...  explanation . [2] [total: 20]",
            "6": "6 0620/52/m/j/10 \u00a9 ucles 2010for examiner\u2019s use2  you are provided with solid w and two solutions, x and y.   carry out the following tests on the solid and the solutions, recording all of your observations  in the table.   conclusions must not be written in the table. tests observations tests on solid w (a)  dissolve half of the sample of solid w in  about 3  cm3 of distilled water.   add a few drops of dilute nitric acid and  then aqueous silver nitrate.   [2] tests on solution x (b) (i)  describe solution x.   test a little of solution x with universal  indicator paper. record the ph.  (ii)  to about 2  cm3 of solution x, add  aqueous sodium hydroxide.  (iii)  to about 2  cm3 of solution x, add  aqueous ammonia drop by drop and shake the test-tube.   now add excess aqueous ammonia  solution to the test-tube.  (iv)  add the rest of solid w to about 3  cm3  of solution x. stir and leave to stand  for 5 minutes.  [1]  ph ... [1]  [2]  [1]  ..  [2] .. ..  [3] tests on solution y (c) (i)  test a little of solution y with universal  indicator paper. record the ph.  (ii)  to about 3  cm3 of solution y, add a  few drops of dilute hydrochloric acid and then aqueous barium chloride. ph ... [1]  ..  [2]",
            "7": "7 0620/52/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (d)  what conclusion can you make about solid w?  .. ... [1]  (e)  what conclusions can you make about solution x?  .. .  .. ... [2]  (f)  identify solution y.  .. ... [2] [total: 20]",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/52/m/j/10notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2010"
        },
        "0620_s10_qp_61.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical may/june 2010  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib10 06_0620_61/4rp\u00a9 ucles 2010 *0444503908* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/61/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  the diagram shows the apparatus used to prepare a gas. the gas is more dense than air. concentrated sulfuric acid  (a)  complete the boxes to name the apparatus. [3]  (b)  identify one mistake in the diagram.  .. ... [1]  (c)  suggest a reason why the gas is passed through concentrated sulfuric acid.  .. ... [1] [total: 5]",
            "3": "3 0620/61/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  three bottles of liquids have lost their labels.  the liquids are known to be:  aqueous sodium iodide, hexene, dilute nitric acid. outline chemical tests you could use to distinguish between the liquids in the three bottles. liquid test result aqueous sodium iodide. ... .. hexene. ... .. dilute nitric acid. ... .. [6] [total: 6]",
            "4": "4 0620/61/m/j/10 \u00a9 ucles 2010for examiner\u2019s use3  the speed of reaction between excess copper carbonate and dilute nitric acid was investigated  using the apparatus below.  the temperature of the nitric acid was 20  \u00b0c. nitric acid copper carbonategas syringe    the volume of carbon dioxide produced was measured every minute for six minutes.  (a)  use the gas syringe diagrams to complete the table of results. time  / minutes gas syringe diagramtotal volume of carbon dioxide produced  / cm3 01 02 03 0 50 60 400 01 02 03 0 50 60 40 30 40 50 60 80 90 100 70 30 40 50 60 80 90 100 70 30 40 50 60 80 90 100 70 30 40 50 60 80 90 100 70 30 40 50 60 80 90 100 701 2 3 45 6 [4]",
            "5": "5 0620/61/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (b)  plot the results on the grid below and draw a smooth line graph. 120 100 80604020 0  0 1 2 3 4 5  6volume of carbon dioxide produced  / cm3 time  / minutes  [4]  (c)  which point appears to be inaccurate? explain why.  .. .  .. ... [2]  (d)  sketch on the grid, the graph you would expect if the experiment was repeated using  nitric acid at a temperature of 60  \u00b0c. [2] [total: 12]",
            "6": "6 0620/61/m/j/10 \u00a9 ucles 2010for examiner\u2019s use4  a student investigated the reaction of aqueous sodium hydroxide with two different acids,  acid c and acid d.  two experiments were carried out. experiment 1   by using a measuring cylinder, 20  cm3 of aqueous sodium hydroxide was poured into a conical  \ufb02 ask and the initial temperature of the solution was measured.   a burette was \ufb01 lled with acid c up to the 0.0  cm3 mark.   5 cm3 of acid c was added to the sodium hydroxide in the \ufb02 ask. the temperature of the  mixture was measured.   further 5  cm3 portions of acid c were added to the mixture in the \ufb02 ask, stirring with the  thermometer until a total volume of 30  cm3 of acid c had been added. the temperatures after  each 5  cm3 portion had been added were measured.  (a) use the thermometer diagrams to record the temperatures in the table of results.",
            "7": "7 0620/61/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s usetable of results volume of acid c added  / cm3 0 5 101520thermometer diagrams temperature  / \u00b0c 25 3030 25 20 40 35 30 40 35 30 40 35 30 35 30 25 35 30 25 35 30 25 [2]",
            "8": "8 0620/61/m/j/10 \u00a9 ucles 2010for examiner\u2019s use experiment 2   the burette was emptied and rinsed with water. experiment 1 was repeated using acid d.  (b)  use the thermometer diagrams to record the temperatures in the table of results. table of results volume of acid d added  / cm3 0 5 101520thermometer diagrams temperature  / \u00b0c 25 3030 25 20 30 25 20 30 25 20 30 25 20 30 25 20 30 25 20 30 25 20 [2]",
            "9": "9 0620/61/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.  clearly label your graphs. 3040 20 10 0 0 5 10 15 20 25 30temperature / \u00b0c volume of acid added  / cm3 [6]  (d)  from your graph, deduce the temperature of the mixture when 3  cm3 of acid c reacted  with sodium hydroxide in experiment 1.  show clearly on the graph  how you worked out your answer.  ... \u00b0c [2]",
            "10": "10 0620/61/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (e) (i)  which experiment produced the larger temperature change?  ..  [1]  (ii)  suggest why the temperature change is greater in this experiment.  .. ..  .. ..  ..  [2]  (f)  why was the burette rinsed with water in experiment 2?  .. .  .. ... [1]  (g)  predict the temperature of the reaction mixture in experiment 2 after 1 hour. explain your  answer.  .. .  .. .  .. ... [2] [total: 18]",
            "11": "11 0620/61/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  solid e was analysed. e was an aluminium salt.  the tests on the solid and some of the observations are in the following table. complete the observations in the table. tests observations tests on solid e (a)  appearance of solid e. white crystalline solid (b)   a little of solid e was heated in a test-tube.colourless drops of liquid formed at the top  of the tube (c)  a little of solid e was dissolved in distilled  water.   the solution was divided into four test-tubes and the following tests were carried out.  (i)  to the \ufb01 rst test-tube of solution, drops  of aqueous sodium hydroxide were added.   excess sodium hydroxide was then  added to the test-tube.  (ii)  test (i) was repeated using aqueous  ammonia solution instead of aqueous sodium hydroxide.  (iii)  to the third test-tube of solution,  dilute hydrochloric acid was added, followed by barium chloride solution.  (iv)  to the fourth test-tube of solution,  aqueous sodium hydroxide and aluminium powder were added.  the mixture was heated. ..  ..  [3] ... ... [2] no reaction effervescence pungent gas given off turned damp litmus paper blue",
            "12": "12 0620/61/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (d)  what does test (b) tell you about solid e.  .. .  .. ... [1]  (e)  identify the gas given off in test (c)(iv) .  .. ... [1]  (f)  what conclusions can you draw about solid e?  .. .  .. ... [2] [total: 9]",
            "13": "13 0620/61/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use6  hydrated cobalt chloride crystals, coc l 2.6h2o, were heated in the apparatus shown below. icew  (a)  indicate on the diagram, using an arrow, where heat is applied. [1]  (b)  the crystals change colour from .. to .. . [1]  (c)  what is the purpose of the ice?  .. .  .. .. [1]  (d)  why is the tube open at point w?  .. .. [1] [total: 4]",
            "14": "14 0620/61/m/j/10 \u00a9 ucles 2010for examiner\u2019s use7  malachite is a naturally occurring form of copper carbonate. outline how a sample of copper  metal could be obtained from large lumps of malachite in the laboratory.  copper is one of the least reactive metals. your answer should include any chemicals used and conditions.  ..   ..   ..   ..   ..   ..   ..   ..   .. .. [6] [total: 6]",
            "15": "15 0620/61/m/j/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/61/m/j/10blank page \u00a9 ucles 2010"
        },
        "0620_s10_qp_62.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical may/june 2010  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib10 06_0620_62/4rp\u00a9 ucles 2010 *3839499632* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/62/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  the diagrams show three sets of apparatus, f, g and h, used to separate three different  mixtures. fg h  (a)  complete the boxes to name the apparatus used. [3]  (b) (i)  which apparatus is used to obtain crystals of a salt from a solution of the salt?  ..  [1]  (ii)  which apparatus is used to separate a mixture of coloured dyes?  ..  [1] [total: 5]",
            "3": "3 0620/62/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  a student investigated the green colour in grass.  the student followed these instructions.  1  cut the grass into small pieces and crush the grass by grinding with sand and ethanol.  2 decant the liquid.  3  investigate which colours are present in the green solution.  (a)  name the apparatus used to crush the grass in instruction 1.  .. ... [1]  (b)  explain the term decant .  .. ... [1]  (c)  outline how the student could carry out instruction 3. you may draw a diagram to help  you answer this question.  .. .  .. .  .. .  .. .  .. .  .. ... [4] [total: 6]",
            "4": "4 0620/62/m/j/10 \u00a9 ucles 2010for examiner\u2019s use3  two students investigated the speed of reaction between excess calcium carbonate and  dilute hydrochloric acid using the apparatus below. calcium carbonatewater dilute hydrochloric acid measuring  cylinder   large lumps of calcium carbonate were used.  the volume of carbon dioxide produced was measured every minute for \ufb01 ve minutes.  (a)  use the measuring cylinder diagrams to complete the table of results. time  / minutesmeasuring cylinder diagramtotal volume of carbon dioxide produced  / cm3 0 12 3450  5  10  15 20 25 25  30  35  35 40 45 40 45 50 40 45 50 [3]",
            "5": "5 0620/62/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (b)  plot the results on the grid below and draw a smooth line graph. 012345volume of carbon dioxide produced  / cm3 time  / minutes50 40302010 0 [4]  (c)  which point appears to be inaccurate? explain why.  .. .  .. ... [2]  (d)  sketch on the grid, the graph you would expect if the experiment was repeated using  small lumps of calcium carbonate. [2] [total: 11]",
            "6": "6 0620/62/m/j/10 \u00a9 ucles 2010for examiner\u2019s use4  a student investigated the reaction of aqueous potassium hydroxide with two different acids,  acid c and acid d.  two experiments were carried out.  experiment 1   by using a measuring cylinder, 40  cm3 of aqueous potassium hydroxide was poured into a  conical \ufb02 ask and the initial temperature of the solution was measured.   a burette was \ufb01 lled with acid c up to the 0.0  cm3 mark.   10  cm3 of acid c was added to the potassium hydroxide in the \ufb02 ask. the temperature of the  mixture was measured.   further 10  cm3 portions of acid c were added to the mixture in the \ufb02 ask, stirring with the  thermometer until a total volume of 60  cm3 of acid c had been added. the temperatures after  each 10  cm3 portion had been added were measured.  (a) use the thermometer diagrams to record the temperatures in the table of results.",
            "7": "7 0620/62/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s usetable of results volume of acid c added  / cm3 0 10 203040thermometer diagrams temperature  / \u00b0c 506030 25 20 30 25 20 30 25 20 30 25 20 30 25 20 30 25 20 30 25 20 [2]",
            "8": "8 0620/62/m/j/10 \u00a9 ucles 2010for examiner\u2019s use experiment 2   the burette was emptied and rinsed with water. experiment 1 was repeated using acid d.  (b)  use the thermometer diagrams to record the temperatures in the table of results. table of results volume of acid d added  / cm3 0 10 203040thermometer diagrams temperature  / \u00b0c 506030 25 20 40 35 30 40 35 30 40 35 30 35 30 25 35 30 25 35 30 25 [2]",
            "9": "9 0620/62/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.  clearly label your graphs. 3040 20 10 0 0 1 02 03 04 05 0 60temperature / \u00b0c volume of acid added  / cm3 [6]  (d)  from your graph, deduce the temperature of the mixture when 6  cm3 of acid c reacted  with potassium hydroxide in experiment 1.  show clearly on the graph  how you worked out your answer.  ... \u00b0c [2]",
            "10": "10 0620/62/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (e) (i)  which experiment produced the larger temperature change?  ..  [1]  (ii)  suggest why the temperature change is greater in this experiment.  .. ..  .. ..  ..  [2]  (f)  why was the burette rinsed with water in experiment 2?  .. .  .. ... [1]  (g)  predict the temperature of the reaction mixture in experiment 2 after 1 hour. explain your  answer.  .. .  .. .  .. ... [2] [total: 18]",
            "11": "11 0620/62/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  solid e was analysed. e was a calcium salt.  the tests on the solid and some of the observations are in the following table. complete the observations in the table. tests observations tests on solid e (a)  appearance of solid e. white crystalline solid (b)   a little of solid e was heated in a test- tube.colourless drops of liquid formed at the top  of the tube (c)  a little of solid e was dissolved in distilled  water.   the solution was divided into four test-tubes and the following tests were carried out.  (i)  to the \ufb01 rst test-tube of solution, drops  of aqueous sodium hydroxide were added.   excess sodium hydroxide was then  added to the test-tube.  (ii)  test (i) was repeated using aqueous  ammonia solution instead of aqueous sodium hydroxide.  (iii)  to the third test-tube of solution,  dilute hydrochloric acid was added followed by barium chloride solution.  (iv)  to the fourth test-tube of solution,  aqueous sodium hydroxide and aluminium powder were added.  the mixture was heated. ..  ..  [3] ... ... [1] no reaction effervescence pungent gas given off turned damp litmus paper blue",
            "12": "12 0620/62/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (d)  what does test (b) tell you about solid e.  .. .  .. ... [1]  (e)  what does test (c)(iii)  tell you about solid e?  .. ... [1]  (f)  identify the gas given off in test (c)(iv) .  .. ... [1]  (g)  what conclusions can you draw about solid e?  .. .  .. ... [2] [total: 9]",
            "13": "13 0620/62/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use6  concentrated hydrochloric acid was broken down by the passage of electricity using this  apparatus. gas a gas b concentrated hydrochloric acid electrodes + \u2013  (a)  what is the name of this process?  .. ... [1]  (b)  suggest a suitable material from which to make the electrodes.  .. ... [1]  (c)  gas a is chlorine. give a test for chlorine.  test . ...  result ...  [2]  (d)  gas b pops when tested with a lighted splint. what is gas b?  .. ... [1] [total: 5]",
            "14": "14 0620/62/m/j/10 \u00a9 ucles 2010for examiner\u2019s use7  metal cooking containers, such as saucepans, can be made from copper or steel.   outline experiments that could be carried out to show which of these metals would be most  suitable for a saucepan.   you are provided with pieces of copper and steel foil.  common laboratory chemicals and apparatus are available.  ..   ..   ..   ..   ..   ..   ..   ..   ..   ..   .. .. [6] [total: 6]",
            "15": "15 0620/62/m/j/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/62/m/j/10blank page \u00a9 ucles 2010"
        },
        "0620_s10_qp_63.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical may/june 2010  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib10 06_0620_63/fp\u00a9 ucles 2010 *8990937183* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/63/m/j/10 \u00a9 ucles 2010for examiner\u2019s use1  the diagrams show three sets of apparatus, f, g and h, used to separate three different  mixtures. fg h  (a)  complete the boxes to name the apparatus used. [3]  (b) (i)  which apparatus is used to obtain crystals of a salt from a solution of the salt?  ..  [1]  (ii)  which apparatus is used to separate a mixture of coloured dyes?  ..  [1] [total: 5]",
            "3": "3 0620/63/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  a student investigated the green colour in grass.  the student followed these instructions.  1  cut the grass into small pieces and crush the grass by grinding with sand and ethanol.  2 decant the liquid.  3  investigate which colours are present in the green solution.  (a)  name the apparatus used to crush the grass in instruction 1.  .. ... [1]  (b)  explain the term decant .  .. ... [1]  (c)  outline how the student could carry out instruction 3. you may draw a diagram to help  you answer this question.  .. .  .. .  .. .  .. .  .. .  .. ... [4] [total: 6]",
            "4": "4 0620/63/m/j/10 \u00a9 ucles 2010for examiner\u2019s use3  two students investigated the speed of reaction between excess calcium carbonate and  dilute hydrochloric acid using the apparatus below. calcium carbonatewater dilute hydrochloric acid measuring  cylinder   large lumps of calcium carbonate were used.  the volume of carbon dioxide produced was measured every minute for \ufb01 ve minutes.  (a)  use the measuring cylinder diagrams to complete the table of results. time  / minutesmeasuring cylinder diagramtotal volume of carbon dioxide produced  / cm3 0 12 3450  5  10  15 20 25 25  30  35  35 40 45 40 45 50 40 45 50 [3]",
            "5": "5 0620/63/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (b)  plot the results on the grid below and draw a smooth line graph. 012345volume of carbon dioxide produced  / cm3 time  / minutes50 40302010 0 [4]  (c)  which point appears to be inaccurate? explain why.  .. .  .. ... [2]  (d)  sketch on the grid, the graph you would expect if the experiment was repeated using  small lumps of calcium carbonate. [2] [total: 11]",
            "6": "6 0620/63/m/j/10 \u00a9 ucles 2010for examiner\u2019s use4  a student investigated the reaction of aqueous potassium hydroxide with two different acids,  acid c and acid d.  two experiments were carried out.  experiment 1   by using a measuring cylinder, 40  cm3 of aqueous potassium hydroxide was poured into a  conical \ufb02 ask and the initial temperature of the solution was measured.   a burette was \ufb01 lled with acid c up to the 0.0  cm3 mark.   10  cm3 of acid c was added to the potassium hydroxide in the \ufb02 ask. the temperature of the  mixture was measured.   further 10  cm3 portions of acid c were added to the mixture in the \ufb02 ask, stirring with the  thermometer until a total volume of 60  cm3 of acid c had been added. the temperatures after  each 10  cm3 portion had been added were measured.  (a) use the thermometer diagrams to record the temperatures in the table of results.",
            "7": "7 0620/63/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s usetable of results volume of acid c added  / cm3 0 10 203040thermometer diagrams temperature  / \u00b0c 506030 25 20 30 25 20 30 25 20 30 25 20 30 25 20 30 25 20 30 25 20 [2]",
            "8": "8 0620/63/m/j/10 \u00a9 ucles 2010for examiner\u2019s use experiment 2   the burette was emptied and rinsed with water. experiment 1 was repeated using acid d.  (b)  use the thermometer diagrams to record the temperatures in the table of results. table of results volume of acid d added  / cm3 0 10 203040thermometer diagrams temperature  / \u00b0c 506030 25 20 40 35 30 40 35 30 40 35 30 35 30 25 35 30 25 35 30 25 [2]",
            "9": "9 0620/63/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.  clearly label your graphs. 3040 20 10 0 0 1 02 03 04 05 0 60temperature / \u00b0c volume of acid added  / cm3 [6]  (d)  from your graph, deduce the temperature of the mixture when 6  cm3 of acid c reacted  with potassium hydroxide in experiment 1.  show clearly on the graph  how you worked out your answer.  ... \u00b0c [2]",
            "10": "10 0620/63/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (e) (i)  which experiment produced the larger temperature change?  ..  [1]  (ii)  suggest why the temperature change is greater in this experiment.  .. ..  .. ..  ..  [2]  (f)  why was the burette rinsed with water in experiment 2?  .. .  .. ... [1]  (g)  predict the temperature of the reaction mixture in experiment 2 after 1 hour. explain your  answer.  .. .  .. .  .. ... [2] [total: 18]",
            "11": "11 0620/63/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  solid e was analysed. e was a calcium salt.  the tests on the solid and some of the observations are in the following table. complete the observations in the table. tests observations tests on solid e (a)  appearance of solid e. white crystalline solid (b)   a little of solid e was heated in a test- tube.colourless drops of liquid formed at the top  of the tube (c)  a little of solid e was dissolved in distilled  water.   the solution was divided into four test-tubes and the following tests were carried out.  (i)  to the \ufb01 rst test-tube of solution, drops  of aqueous sodium hydroxide were added.   excess sodium hydroxide was then  added to the test-tube.  (ii)  test (i) was repeated using aqueous  ammonia solution instead of aqueous sodium hydroxide.  (iii)  to the third test-tube of solution,  dilute hydrochloric acid was added followed by barium chloride solution.  (iv)  to the fourth test-tube of solution,  aqueous sodium hydroxide and aluminium powder were added.  the mixture was heated. ..  ..  [3] ... ... [1] no reaction effervescence pungent gas given off turned damp litmus paper blue",
            "12": "12 0620/63/m/j/10 \u00a9 ucles 2010for examiner\u2019s use (d)  what does test (b) tell you about solid e.  .. .  .. ... [1]  (e)  what does test (c)(iii)  tell you about solid e?  .. ... [1]  (f)  identify the gas given off in test (c)(iv) .  .. ... [1]  (g)  what conclusions can you draw about solid e?  .. .  .. ... [2] [total: 9]",
            "13": "13 0620/63/m/j/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use6  concentrated hydrochloric acid was broken down by the passage of electricity using this  apparatus. gas a gas b concentrated hydrochloric acid electrodes + \u2013  (a)  what is the name of this process?  .. ... [1]  (b)  suggest a suitable material from which to make the electrodes.  .. ... [1]  (c)  gas a is chlorine. give a test for chlorine.  test . ...  result ...  [2]  (d)  gas b pops when tested with a lighted splint. what is gas b?  .. ... [1] [total: 5]",
            "14": "14 0620/63/m/j/10 \u00a9 ucles 2010for examiner\u2019s use7  metal cooking containers, such as saucepans, can be made from copper or steel.   outline experiments that could be carried out to show which of these metals would be most  suitable for a saucepan.   you are provided with pieces of copper and steel foil.  common laboratory chemicals and apparatus are available.  ..   ..   ..   ..   ..   ..   ..   ..   ..   ..   .. .. [6] [total: 6]",
            "15": "15 0620/63/m/j/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/63/m/j/10blank page \u00a9 ucles 2010"
        },
        "0620_w10_qp_11.pdf": {
            "1": "    this document consists of 17 printed pages and 3 blank pages.  ib10 11_0620_11/3rp  \u00a9 ucles 2010  [turn over       *5060581 702* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  october/november 2010       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2010 0620/11/o/n/10  1 in which changes do the particles move further apart?     w x  gas      liquid      solid   y z    a w and x b w and z c x and y d y and z      2 chromatography is used to find out if a banned dye, p, is present in foodstuffs.    the results are shown in the diagram.    which foodstuff contains p?    a p bcd     3 a mixture of ethanol and methanol are separated by fractional distillation.    this method of separation depends on a difference in property x of these two alcohols.     what is property x?  a boiling point  b colour  c melting point  d solubility     4 element x has a nucleon (mass) number of 19 and a proton (atomic) number of 9.    to which group in the periodic table does it belong?  a i b iii c vii d 0     ",
            "3": "3  \u00a9 ucles 2010 0620/11/o/n/10 [turn over  5 the table shows the structure of different atoms and ions.    particle proton  number nucleon  number number of  protons number of  neutrons number of  electrons  mg 12 24 12 w 12  mg2+ x 24 12 12 10  f 9 19 9 y 9  f\u2013 9 19 9 10 z    what are the values of w, x, y and z?     w x y z  a 10 10 9 9  b 10 12 10 9  c 12 10 9 10  d 12 12 10 10      6 two isotopes of hydrogen are h1 1 and h2 1.    which diagram shows the arrangement of particles in the two isotopes?    a  b c d1h 1 2h 1  e  n e  e  n e p p  e e npp e e p pp p np nekey  = an electron  = a proton = a neutron  = a nucleus       ",
            "4": "4  \u00a9 ucles 2010 0620/11/o/n/10  7 element x is shiny and can be formed into a sheet by hammering.    which row correctly describes the properties of element x?     conducts electricity melts below 25  \u00b0c  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     8 the electronic structures of atoms x and y are shown.    x y     x and y form a covalent compound.    what is its formula?  a xy 5 b xy 3 c xy d x 3y     9 which diagram does not show the outer shell electrons in the molecule correctly?    h hab c d h cl cl cl hh h hc     ",
            "5": "5  \u00a9 ucles 2010 0620/11/o/n/10 [turn over  10 the chemical compositions of two substances, w and x, are given.    w na(a l si3)o8  x ca(a l 2si2)o8    which statements are correct?    1 w and x contain the same amount of oxygen.  2 w contains three times as much silicon as x.  3 x contains twice as much aluminium as w.    a 1 and 2 b 1 and 3 c 2 and 3 d 1, 2 and 3      11 the diagram shows apparatus used in an attempt to electroplate a metal ring with copper.    +\u2013 aqueous copper( ii) sulfate (electrolyte)metal ring copper electrode bulb     the experiment did not work.    what change is needed in the experiment to make it work?  a add solid copper( ii) sulfate to the electrolyte.  b increase the temperature of the electrolyte.  c replace the copper electrode by a carbon electrode.  d reverse the connections to the battery.     ",
            "6": "6  \u00a9 ucles 2010 0620/11/o/n/10  12 when concentrated sodium chloride solution is electrolysed, elements x and y are formed.    x \u2013+y concentrated sodium chloridesolution     what are x and y?     x y  a chlorine hydrogen  b hydrogen chlorine  c hydrogen oxygen  d oxygen hydrogen     13 substance x was electrolysed in an electrolytic cell.    a coloured gas was formed at the anode and a metal was formed at the cathode.    cathode substance xanodepower supply     what is substance x?  a aqueous sodium chloride  b molten lead bromide  c molten zinc oxide  d solid sodium chloride     ",
            "7": "7  \u00a9 ucles 2010 0620/11/o/n/10 [turn over  14 which is an endothermic process?  a burning hydrogen  b distilling petroleum  c reacting potassium with water  d using petrol in a motor car engine      15 the diagrams show some pieces of laboratory equipment.    3 thermometer 60 3045 152 stop-clock1 balance     which equipment is needed to find out whether dissolving salt in water is an endothermic  process?  a 1 only b 1 and 3 c 2 and 3 d 3 only      16 calcium carbonate was reacted with hydrochloric acid in a conical flask. the flask was placed on  a balance and the mass of the flask and contents was recorded as the reaction proceeded.    during the reaction, carbon dioxide gas was given off.    the reaction was carried out at two different temperatures.    which row is correct?     change in mass temperature at which mass  changed more quickly  a decrease higher temperature  b decrease lower temperature  c increase higher temperature  d increase lower temperature    ",
            "8": "8  \u00a9 ucles 2010 0620/11/o/n/10  17 when pink crystals of cobalt( ii) chloride are heated, steam is given off and the colour of the solid  changes to blue.    coc l2.6h 2o  coc l2 + 6h 2o    what happens when water is added to the blue solid?     colour temperature  a changes to pink decreases  b changes to pink increases   c remains blue decreases   d remains blue increases     18 the red colour in some pottery glazes may be formed as a result of the reactions shown.    cuco3 cuo + co2  cuo + sno cu + sno2 heat      these equations show that \u2026\u20261\u2026\u2026 is oxidised and \u2026\u20262\u2026\u2026 is reduced.    which substances correctly complete gaps 1 and 2 in the above sentence?     1 2  a co 2 sno 2  b cuco 3 cuo  c cuo sno  d sno cuo    ",
            "9": "9  \u00a9 ucles 2010 0620/11/o/n/10 [turn over  19 some barium iodide is dissolved in water.    aqueous lead( ii) nitrate is added to the solution until no more precipitate forms.     this precipitate, x, is filtered off.    dilute sulfuric acid is added to the filtrate and another precipitate, y, forms.    what are the colours of precipitates x and y?     x y  a white white  b white yellow  c yellow white  d yellow yellow     20 which reaction will result in a decrease in ph?  a adding calcium hydroxide to acid soil  b adding citric acid to sodium hydrogen carbonate solution  c adding sodium chloride to silver nitrate solution  d adding sodium hydroxide to hydrochloric acid     ",
            "10": "10  \u00a9 ucles 2010 0620/11/o/n/10  21 the oxide of element x was added to an acid. it reacted to form a salt and water.    acidoxide of element x     what is the ph of the acid before the reaction and what type of element is x?     ph type of element x  a greater than 7 metal  b greater than 7 non-metal  c less than 7 metal  d less than 7 non-metal      22 a salt is made by adding an excess of an insoluble metal oxide to an acid.    how can the excess metal oxide be removed?  a chromatography  b crystallisation  c distillation  d filtration     23 the table compares the properties of group i elements with those of transition elements.    which entry in the table is correct?     property group i elements transition elements  a catalytic activity low high  b density high low  c electrical conductivity low high  d melting point high low    ",
            "11": "11  \u00a9 ucles 2010 0620/11/o/n/10 [turn over  24 which compound is likely to be coloured?  a kmno 4 b kno 3 c k2co 3 d k2so 4      25 the diagram shows the positions of elements p, q, r, s and t in the periodic table.    these letters are not the chemical symbols for the elements.    p qrst     which statement about the properties of these elements is correct?  a p reacts more vigorously with water than does q.  b p, q and r are all metals.  c t exists as diatomic molecules.  d t is more reactive than s.     26 the table shows some reactions of the halogens.    which reaction is the most likely to be explosive?    reaction chlorine gas bromine gas iodine gas  reaction with hydrogen a b c  reaction with iron very vigorous less vigorous d    ",
            "12": "12  \u00a9 ucles 2010 0620/11/o/n/10  27 which diagram could represent the structure of an alloy?    \u2013  \u2013 \u2013 \u2013  \u2013  \u2013 + + + +  + + a b  c d       28 which property do all metals have?  a their boiling points are low.  b their densities are low.  c they conduct electricity.  d they react with water.     29 some metals react readily with dilute hydrochloric acid.    some metals can be extracted by heating their oxides with carbon.    for which metal are both statements correct?  a calcium  b copper  c iron  d magnesium     ",
            "13": "13  \u00a9 ucles 2010 0620/11/o/n/10 [turn over  30 the diagram shows the materials used in the production of steel from impure iron.    impure ironsteel an oxide of element xoxygen     what could element x be?  a calcium  b carbon  c nitrogen  d sulfur     31 which diagram shows a common use of stainless steel?    d a b c       32 why is chlorination used in water treatment?    a to kill bacteria in the water  b to make the water neutral  c to make the water taste better  d to remove any salt in the water    33 which pollutant, found in car exhaust fumes, does not come from the fuel?  a carbon monoxide  b hydrocarbons  c lead compounds  d nitrogen oxides    ",
            "14": "14  \u00a9 ucles 2010 0620/11/o/n/10  34 which information about carbon dioxide and methane is correct?      carbon dioxide methane  a formed when vegetation decomposes \u0013 \u0017  b greenhouse gas \u0013 \u0013  c present in unpolluted air \u0017 \u0017  d produced during respiration \u0017 \u0013     35 a bag of fertiliser \u2018watch it grow\u2019 contains ammonium sulfate and potassium sulfate.    which of the three elements n, p and k does \u2018watch it grow\u2019 contain?     n p k  a \u0013 \u0013 \u0017  b \u0013 \u0017 \u0013  c \u0017 \u0013 \u0017  d \u0017 \u0017 \u0013      36 a test-tube containing damp iron wool is inverted in water.    after three days, the water level inside the test-tube has risen.    waterdamp iron wool     which statement explains this rise?  a iron oxide has been formed.  b iron wool has been reduced.  c oxygen has been formed.  d the temperature of the water has risen.     ",
            "15": "15  \u00a9 ucles 2010 0620/11/o/n/10 [turn over  37 the diagram shows the structure of a compound.    h ch c hh ch o hh ch     to which classes of compound does this molecule belong?     alkane alkene alcohol  a no no no  b no yes yes  c yes no yes  d yes yes yes     38 which structures show compounds that are members of the same homologous series?    o ch hch hch hh h1 h ch hch hco o h2 h ch hch hc hh hc3 h ch hch hch hch ho h4     a 1 and 2  b  1 and 4  c  2 and 3 d 3 and 4     39 ethene reacts with y to produce ethanol.    ethene + y \u2192 ethanol    what is y?  a hydrogen  b oxygen  c steam  d yeast   ",
            "16": "16  \u00a9 ucles 2010 0620/11/o/n/10  40 in an oil refinery, crude oil is separated into useful fractions.     the diagram shows some of these fractions.    pre-heat 400  \u00b0crefinery gases gasolenexdieselyz     what are fractions x, y and z?     x y z  a fuel oil bitumen paraffin (kerosene)  b fuel oil paraffin (kerosene) bitumen  c paraffin (kerosene) bitumen fuel oil  d paraffin (kerosene) fuel oil bitumen     ",
            "17": "17  \u00a9 ucles 2010 0620/11/o/n/10  blank page   ",
            "18": "18  \u00a9 ucles 2010 0620/11/o/n/10  blank page   ",
            "19": "19  \u00a9 ucles 2010 0620/11/o/n/10  blank page   ",
            "20": "20      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2010 0620/11/o/n/10   group  140  ce  cerium  58 141  pr  praseodymium  59 144  nd  neodymium  60 pm  promethium  61 150  sm  samarium  62 152  eu  europium  63 157  gd  gadolinium  64 159  tb  t erbiu m  65 162  dy  dysprosium  66 165  ho  holmium  67 167  er  erbium  68 169  tm  thulium  69 173  yb  ytterbium  70 175  lu  lutetium  71  232  th  thorium  90 pa  protactinium  91 238  u  uranium  92 np  neptunium  93 pu  plutonium  94 am  americium  95 cm  curium  96 bk  berkelium  97 cf  californium  98 es  einsteinium  99 fm  fermium  100 md  mendelevium  101 no  nobelium  102 lr  lawrencium  103 1  h  hydrogen  1  7  li  lithium  3  23  na  sodium  1 1 24  mg  magnesium  12  40  ca  calcium  20 45  sc  scandium  21 48  t i  t itaniu m  22 51  v  v anadiu m  23 52  cr  chromium  24 55  mn  manganese  25 56  fe  iron  26 59  co  cobalt  27 59  ni  nickel  28 64  cu  copper  29 65  zn  zinc  30 70  ga gallium  31 27  a l  aluminium  13 1 1  b  boron  5 12  c  carbon  6 14  n  nitrogen  7 16  o  oxygen  8 19  f  fluorine  9  28  si  silicon  14 31  p  phosphorus  15 32  s  sulfur  16 35.5  c l  chlorine  17 40  ar  argon  18 20  ne  neon  10 4  he  helium  2  73  ge  germanium  32 75  as  arsenic  33 79  se  selenium  34 80  br  bromine  35 84  kr  krypton  36 39  k  potassium  19  88  sr  strontium  38 89  y  yttrium  39 91  zr  zirconium  40 93  nb  niobium  41 96  mo  molybdenum  42 t c  t echnetiu m  43 101  ru  ruthenium  44 103  rh  rhodium  45 106  pd  palladium  46 108  ag  silver  47 1 1 2  cd  cadmium  48 1 1 5  in indium  49 1 1 9  sn  t i n  50 122  sb  antimony  51 128  t e  t elluriu m  52 127  i iodine  53 131  xe  xenon  54  137  ba  barium  56 139  la  lanthanum  57         * 178  hf  hafnium  72 181  t a  t antalu m  73 184  w  t ungste n  74 186  re  rhenium  75 190  os  osmium  76 192  ir  iridium  77 195  pt  platinum  78 197  au  gold  79 201  hg  mercury  80 204  t l  thallium  81 207  pb  lead  82 209  bi  bismuth  83 po  polonium  84 at  astatine  85 rn  radon  86  fr  francium  87 227  ac  actinium  89 9  be  beryllium  4 i ii iii iv v vi vii 0  85  rb  rubidium  37  133  cs  caesium  55  226  ra  radium  88  the volume of one mole of an y gas is 2 4 dm 3 at room temperature and pressure ( r .t.p.) . a  x  b a = relative atomic mass  x  = atomic symbol  b = proton (atomic) number key * 58-71 lanthanoid series  90-103 actinoid series d a t a  shee t  the periodic  t able of the element s   "
        },
        "0620_w10_qp_12.pdf": {
            "1": "    this document consists of 16 printed pages.  ib10 11_0620_12/fp  \u00a9 ucles 2010  [turn over       *7210437430* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  october/november 2010       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.      ",
            "2": "2  \u00a9 ucles 2010 0620/12/o/n/10  1 in which changes do the particles move further apart?     w x  gas      liquid      solid   y z    a w and x b w and z c x and y d y and z      2 a mixture of ethanol and methanol are separated by fractional distillation.    this method of separation depends on a difference in property x of these two alcohols.     what is property x?  a boiling point  b colour  c melting point  d solubility      3 chromatography is used to find out if a banned dye, p, is present in foodstuffs.    the results are shown in the diagram.    which foodstuff contains p?    a p bcd     4 which diagram does not show the outer shell electrons in the molecule correctly?    h hab c d h cl cl cl hh h hc     ",
            "3": "3  \u00a9 ucles 2010 0620/12/o/n/10 [turn over  5 the chemical compositions of two substances, w and x, are given.    w na(a l si3)o8  x ca(a l 2si2)o8    which statements are correct?    1 w and x contain the same amount of oxygen.  2 w contains three times as much silicon as x.  3 x contains twice as much aluminium as w.    a 1 and 2 b 1 and 3 c 2 and 3 d 1, 2 and 3      6 the electronic structures of atoms x and y are shown.    x y     x and y form a covalent compound.    what is its formula?  a xy 5 b xy 3 c xy d x 3y      7 element x is shiny and can be formed into a sheet by hammering.    which row correctly describes the properties of element x?     conducts electricity melts below 25  \u00b0c  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "4": "4  \u00a9 ucles 2010 0620/12/o/n/10  8 two isotopes of hydrogen are h1 1 and h2 1.    which diagram shows the arrangement of particles in the two isotopes?    a  b c d1h 1 2h 1  e  n e  e  n e p p  e e npp e e p pp p np nekey  = an electron  = a proton = a neutron  = a nucleus        9 the table shows the structure of different atoms and ions.    particle proton  number nucleon  number number of  protons number of  neutrons number of  electrons  mg 12 24 12 w 12  mg2+ x 24 12 12 10  f 9 19 9 y 9  f\u2013 9 19 9 10 z    what are the values of w, x, y and z?     w x y z  a 10 10 9 9  b 10 12 10 9  c 12 10 9 10  d 12 12 10 10    ",
            "5": "5  \u00a9 ucles 2010 0620/12/o/n/10 [turn over  10 element x has a nucleon (mass) number of 19 and a proton (atomic) number of 9.    to which group in the periodic table does it belong?  a i b iii c vii d 0     11 substance x was electrolysed in an electrolytic cell.    a coloured gas was formed at the anode and a metal was formed at the cathode.    cathode substance xanodepower supply     what is substance x?  a aqueous sodium chloride  b molten lead bromide  c molten zinc oxide  d solid sodium chloride     ",
            "6": "6  \u00a9 ucles 2010 0620/12/o/n/10  12 the diagram shows apparatus used in an attempt to electroplate a metal ring with copper.    +\u2013 aqueous copper( ii) sulfate (electrolyte)metal ring copper electrode bulb     the experiment did not work.    what change is needed in the experiment to make it work?  a add solid copper( ii) sulfate to the electrolyte.  b increase the temperature of the electrolyte.  c replace the copper electrode by a carbon electrode.  d reverse the connections to the battery.     13 when concentrated sodium chloride solution is electrolysed, elements x and y are formed.    x \u2013+y concentrated sodium chloridesolution     what are x and y?     x y  a chlorine hydrogen  b hydrogen chlorine  c hydrogen oxygen  d oxygen hydrogen     ",
            "7": "7  \u00a9 ucles 2010 0620/12/o/n/10 [turn over  14 calcium carbonate was reacted with hydrochloric acid in a conical flask. the flask was placed on  a balance and the mass of the flask and contents was recorded as the reaction proceeded.    during the reaction, carbon dioxide gas was given off.    the reaction was carried out at two different temperatures.    which row is correct?     change in mass temperature at which mass  changed more quickly  a decrease higher temperature  b decrease lower temperature  c increase higher temperature  d increase lower temperature      15 some barium iodide is dissolved in water.    aqueous lead( ii) nitrate is added to the solution until no more precipitate forms.    this precipitate, x, is filtered off.    dilute sulfuric acid is added to the filtrate and another precipitate, y, forms.    what are the colours of precipitates x and y?     x y  a white white  b white yellow  c yellow white  d yellow yellow    ",
            "8": "8  \u00a9 ucles 2010 0620/12/o/n/10  16 when pink crystals of cobalt( ii) chloride are heated, steam is given off and the colour of the solid  changes to blue.    coc l2.6h 2o  coc l2 + 6h 2o    what happens when water is added to the blue solid?     colour temperature  a changes to pink decreases  b changes to pink increases   c remains blue decreases   d remains blue increases     17 the diagrams show some pieces of laboratory equipment.    3 thermometer 60 3045 152 stop-clock1 balance     which equipment is needed to find out whether dissolving salt in water is an endothermic  process?  a 1 only b 1 and 3 c 2 and 3 d 3 only     18 which reaction will result in a decrease in ph?  a adding calcium hydroxide to acid soil  b adding citric acid to sodium hydrogen carbonate solution  c adding sodium chloride to silver nitrate solution  d adding sodium hydroxide to hydrochloric acid    19 which is an endothermic process?  a burning hydrogen  b distilling petroleum  c reacting potassium with water  d using petrol in a motor car engine    ",
            "9": "9  \u00a9 ucles 2010 0620/12/o/n/10 [turn over  20 the red colour in some pottery glazes may be formed as a result of the reactions shown.    cuco3 cuo + co2  cuo + sno cu + sno2 heat      these equations show that \u2026\u20261\u2026\u2026 is oxidised and \u2026\u20262\u2026\u2026 is reduced.    which substances correctly complete gaps 1 and 2 in the above sentence?     1 2  a co 2 sno 2  b cuco 3 cuo  c cuo sno  d sno cuo      21 the table shows some reactions of the halogens.    which reaction is the most likely to be explosive?    reaction chlorine gas bromine gas iodine gas  reaction with hydrogen a b c  reaction with iron very vigorous less vigorous d      22 which compound is likely to be coloured?  a kmno 4 b kno 3 c k2co 3 d k2so 4      23 a salt is made by adding an excess of an insoluble metal oxide to an acid.    how can the excess metal oxide be removed?  a chromatography  b crystallisation  c distillation  d filtration     ",
            "10": "10  \u00a9 ucles 2010 0620/12/o/n/10  24 the oxide of element x was added to an acid. it reacted to form a salt and water.    acidoxide of element x     what is the ph of the acid before the reaction and what type of element is x?     ph type of element x  a greater than 7 metal  b greater than 7 non-metal  c less than 7 metal  d less than 7 non-metal      25 the table compares the properties of group i elements with those of transition elements.    which entry in the table is correct?     property group i elements transition elements  a catalytic activity low high  b density high low  c electrical conductivity low high  d melting point high low     ",
            "11": "11  \u00a9 ucles 2010 0620/12/o/n/10 [turn over  26 the diagram shows the positions of elements p, q, r, s and t in the periodic table.    these letters are not the chemical symbols for the elements.    p qrst     which statement about the properties of these elements is correct?  a p reacts more vigorously with water than does q.  b p, q and r are all metals.  c t exists as diatomic molecules.  d t is more reactive than s.     27 some metals react readily with dilute hydrochloric acid.    some metals can be extracted by heating their oxides with carbon.    for which metal are both statements correct?  a calcium  b copper  c iron  d magnesium    ",
            "12": "12  \u00a9 ucles 2010 0620/12/o/n/10  28 which diagram could represent the structure of an alloy?    \u2013  \u2013 \u2013 \u2013  \u2013  \u2013 + + + +  + + a b  c d       29 the diagram shows the materials used in the production of steel from impure iron.    impure ironsteel an oxide of element xoxygen     what could element x be?  a calcium  b carbon  c nitrogen  d sulfur     30 which property do all metals have?  a their boiling points are low.  b their densities are low.  c they conduct electricity.  d they react with water.    ",
            "13": "13  \u00a9 ucles 2010 0620/12/o/n/10 [turn over  31 which pollutant, found in car exhaust fumes, does not come from the fuel?  a carbon monoxide  b hydrocarbons  c lead compounds  d nitrogen oxides      32 which diagram shows a common use of stainless steel?    d a b c       33 why is chlorination used in water treatment?    a to kill bacteria in the water  b to make the water neutral  c to make the water taste better  d to remove any salt in the water     34 a test-tube containing damp iron wool is inverted in water.    after three days, the water level inside the test-tube has risen.    waterdamp iron wool     which statement explains this rise?  a iron oxide has been formed.  b iron wool has been reduced.  c oxygen has been formed.  d the temperature of the water has risen.     ",
            "14": "14  \u00a9 ucles 2010 0620/12/o/n/10  35 which information about carbon dioxide and methane is correct?      carbon dioxide methane  a formed when vegetation decomposes \u0013 \u0017  b greenhouse gas \u0013 \u0013  c present in unpolluted air \u0017 \u0017  d produced during respiration \u0017 \u0013     36 a bag of fertiliser \u2018watch it grow\u2019 contains ammonium sulfate and potassium sulfate.    which of the three elements n, p and k does \u2018watch it grow\u2019 contain?     n p k  a \u0013 \u0013 \u0017  b \u0013 \u0017 \u0013  c \u0017 \u0013 \u0017  d \u0017 \u0017 \u0013      37 in an oil refinery, crude oil is separated into useful fractions.     the diagram shows some of these fractions.    pre-heat 400  \u00b0crefinery gases gasolenexdieselyz     what are fractions x, y and z?     x y z  a fuel oil bitumen paraffin (kerosene)  b fuel oil paraffin (kerosene) bitumen  c paraffin (kerosene) bitumen fuel oil  d paraffin (kerosene) fuel oil bitumen     ",
            "15": "15  \u00a9 ucles 2010 0620/12/o/n/10  38 ethene reacts with y to produce ethanol.    ethene + y \u2192 ethanol    what is y?  a hydrogen  b oxygen  c steam  d yeast      39 the diagram shows the structure of a compound.    h ch c hh ch o hh ch     to which classes of compound does this molecule belong?     alkane alkene alcohol  a no no no  b no yes yes  c yes no yes  d yes yes yes      40 which structures show compounds that are members of the same homologous series?    o ch hch hch hh h1 h ch hch hco o h2 h ch hch hc hh hc3 h ch hch hch hch ho h4     a 1 and 2  b  1 and 4  c  2 and 3 d 3 and 4   ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the p ublisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2010 0620/12/o/n/10   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w10_qp_13.pdf": {
            "1": "    this document consists of 16 printed pages.  ib10 11_0620_13/rp  \u00a9 ucles 2010  [turn over       *8947497 463* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  october/november 2010       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2010 0620/13/o/n/10  1 in which changes do the particles move further apart?     w x  gas      liquid      solid   y z    a w and x b w and z c x and y d y and z      2 the table shows the structure of different atoms and ions.    particle proton  number nucleon  number number of  protons number of  neutrons number of  electrons  mg 12 24 12 w 12  mg2+ x 24 12 12 10  f 9 19 9 y 9  f\u2013 9 19 9 10 z    what are the values of w, x, y and z?     w x y z  a 10 10 9 9  b 10 12 10 9  c 12 10 9 10  d 12 12 10 10     3 element x has a nucleon (mass) number of 19 and a proton (atomic) number of 9.    to which group in the periodic table does it belong?  a i b iii c vii d 0      4 a mixture of ethanol and methanol are separated by fractional distillation.    this method of separation depends on a difference in property x of these two alcohols.     what is property x?  a boiling point  b colour  c melting point  d solubility     ",
            "3": "3  \u00a9 ucles 2010 0620/13/o/n/10 [turn over  5 chromatography is used to find out if a banned dye, p, is present in foodstuffs.    the results are shown in the diagram.    which foodstuff contains p?    a p bcd      6 which diagram does not show the outer shell electrons in the molecule correctly?    h hab c d h cl cl cl hh h hc     ",
            "4": "4  \u00a9 ucles 2010 0620/13/o/n/10  7 two isotopes of hydrogen are h1 1 and h2 1.    which diagram shows the arrangement of particles in the two isotopes?    a  b c d1h 1 2h 1  e  n e  e  n e p p  e e npp e e p pp p np nekey  = an electron  = a proton = a neutron  = a nucleus        8 the chemical compositions of two substances, w and x, are given.    w na(a l si3)o8  x ca(a l 2si2)o8    which statements are correct?    1 w and x contain the same amount of oxygen.  2 w contains three times as much silicon as x.  3 x contains twice as much aluminium as w.    a 1 and 2 b 1 and 3 c 2 and 3 d 1, 2 and 3     ",
            "5": "5  \u00a9 ucles 2010 0620/13/o/n/10 [turn over  9 the electronic structures of atoms x and y are shown.    x y     x and y form a covalent compound.    what is its formula?  a xy 5 b xy 3 c xy d x 3y      10 element x is shiny and can be formed into a sheet by hammering.    which row correctly describes the properties of element x?     conducts electricity melts below 25  \u00b0c  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      11 substance x was electrolysed in an electrolytic cell.    a coloured gas was formed at the anode and a metal was formed at the cathode.    cathode substance xanodepower supply     what is substance x?  a aqueous sodium chloride  b molten lead bromide  c molten zinc oxide  d solid sodium chloride ",
            "6": "6  \u00a9 ucles 2010 0620/13/o/n/10  12 the diagram shows apparatus used in an attempt to electroplate a metal ring with copper.    +\u2013 aqueous copper( ii) sulfate (electrolyte)metal ring copper electrode bulb     the experiment did not work.    what change is needed in the experiment to make it work?  a add solid copper( ii) sulfate to the electrolyte.  b increase the temperature of the electrolyte.  c replace the copper electrode by a carbon electrode.  d reverse the connections to the battery.     13 when concentrated sodium chloride solution is electrolysed, elements x and y are formed.    x \u2013+y concentrated sodium chloridesolution     what are x and y?     x y  a chlorine hydrogen  b hydrogen chlorine  c hydrogen oxygen  d oxygen hydrogen     ",
            "7": "7  \u00a9 ucles 2010 0620/13/o/n/10 [turn over  14 calcium carbonate was reacted with hydrochloric acid in a conical flask. the flask was placed on  a balance and the mass of the flask and contents was recorded as the reaction proceeded.    during the reaction, carbon dioxide gas was given off.    the reaction was carried out at two different temperatures.    which row is correct?     change in mass temperature at which mass  changed more quickly  a decrease higher temperature  b decrease lower temperature  c increase higher temperature  d increase lower temperature      15 which is an endothermic process?  a burning hydrogen  b distilling petroleum  c reacting potassium with water  d using petrol in a motor car engine      16 the diagrams show some pieces of laboratory equipment.    3 thermometer 60 3045 152 stop-clock1 balance     which equipment is needed to find out whether dissolving salt in water is an endothermic  process?  a 1 only b 1 and 3 c 2 and 3 d 3 only     ",
            "8": "8  \u00a9 ucles 2010 0620/13/o/n/10  17 which reaction will result in a decrease in ph?  a adding calcium hydroxide to acid soil  b adding citric acid to sodium hydrogen carbonate solution  c adding sodium chloride to silver nitrate solution  d adding sodium hydroxide to hydrochloric acid     18 when pink crystals of cobalt( ii) chloride are heated, steam is given off and the colour of the solid  changes to blue.    coc l 2.6h 2o  coc l2 + 6h 2o    what happens when water is added to the blue solid?     colour temperature  a changes to pink decreases  b changes to pink increases   c remains blue decreases   d remains blue increases    19 the red colour in some pottery glazes may be formed as a result of the reactions shown.    cuco3 cuo + co2  cuo + sno cu + sno2 heat      these equations show that \u2026\u20261\u2026\u2026 is oxidised and \u2026\u20262\u2026\u2026 is reduced.    which substances correctly complete gaps 1 and 2 in the above sentence?     1 2  a co 2 sno 2  b cuco 3 cuo  c cuo sno  d sno cuo    ",
            "9": "9  \u00a9 ucles 2010 0620/13/o/n/10 [turn over  20 some barium iodide is dissolved in water.    aqueous lead( ii) nitrate is added to the solution until no more precipitate forms.     this precipitate, x, is filtered off.    dilute sulfuric acid is added to the filtrate and another precipitate, y, forms.    what are the colours of precipitates x and y?     x y  a white white  b white yellow  c yellow white  d yellow yellow     21 the table shows some reactions of the halogens.    which reaction is the most likely to be explosive?    reaction chlorine gas bromine gas iodine gas  reaction with hydrogen a b c  reaction with iron very vigorous less vigorous d      22 which compound is likely to be coloured?  a kmno 4 b kno 3 c k2co 3 d k2so 4      23 a salt is made by adding an excess of an insoluble metal oxide to an acid.    how can the excess metal oxide be removed?  a chromatography  b crystallisation  c distillation  d filtration     ",
            "10": "10  \u00a9 ucles 2010 0620/13/o/n/10  24 the oxide of element x was added to an acid. it reacted to form a salt and water.    acidoxide of element x     what is the ph of the acid before the reaction and what type of element is x?     ph type of element x  a greater than 7 metal  b greater than 7 non-metal  c less than 7 metal  d less than 7 non-metal      25 the diagram shows the positions of elements p, q, r, s and t in the periodic table.    these letters are not the chemical symbols for the elements.    p qrst     which statement about the properties of these elements is correct?  a p reacts more vigorously with water than does q.  b p, q and r are all metals.  c t exists as diatomic molecules.  d t is more reactive than s.     ",
            "11": "11  \u00a9 ucles 2010 0620/13/o/n/10 [turn over  26 the table compares the properties of group i elements with those of transition elements.    which entry in the table is correct?     property group i elements transition elements  a catalytic activity low high  b density high low  c electrical conductivity low high  d melting point high low     27 which pollutant, found in car exhaust fumes, does not come from the fuel?  a carbon monoxide  b hydrocarbons  c lead compounds  d nitrogen oxides     28 the diagram shows the materials used in the production of steel from impure iron.    impure ironsteel an oxide of element xoxygen     what could element x be?  a calcium  b carbon  c nitrogen  d sulfur     29 which property do all metals have?  a their boiling points are low.  b their densities are low.  c they conduct electricity.  d they react with water.    ",
            "12": "12  \u00a9 ucles 2010 0620/13/o/n/10  30 which diagram could represent the structure of an alloy?    \u2013  \u2013 \u2013 \u2013  \u2013  \u2013 + + + +  + + a b  c d       31 some metals react readily with dilute hydrochloric acid.    some metals can be extracted by heating their oxides with carbon.    for which metal are both statements correct?  a calcium  b copper  c iron  d magnesium     32 which diagram shows a common use of stainless steel?    d a b c      ",
            "13": "13  \u00a9 ucles 2010 0620/13/o/n/10 [turn over  33 why is chlorination used in water treatment?    a to kill bacteria in the water  b to make the water neutral  c to make the water taste better  d to remove any salt in the water      34 a test-tube containing damp iron wool is inverted in water.    after three days, the water level inside the test-tube has risen.    waterdamp iron wool     which statement explains this rise?  a iron oxide has been formed.  b iron wool has been reduced.  c oxygen has been formed.  d the temperature of the water has risen.     35 a bag of fertiliser \u2018watch it grow\u2019 contains ammonium sulfate and potassium sulfate.    which of the three elements n, p and k does \u2018watch it grow\u2019 contain?     n p k  a \u0013 \u0013 \u0017  b \u0013 \u0017 \u0013  c \u0017 \u0013 \u0017  d \u0017 \u0017 \u0013    ",
            "14": "14  \u00a9 ucles 2010 0620/13/o/n/10  36 which information about carbon dioxide and methane is correct?      carbon dioxide methane  a formed when vegetation decomposes \u0013 \u0017  b greenhouse gas \u0013 \u0013  c present in unpolluted air \u0017 \u0017  d produced during respiration \u0017 \u0013     37 ethene reacts with y to produce ethanol.    ethene + y \u2192 ethanol    what is y?  a hydrogen  b oxygen  c steam  d yeast     38 in an oil refinery, crude oil is separated into useful fractions.     the diagram shows some of these fractions.    pre-heat 400  \u00b0crefinery gases gasolenexdieselyz     what are fractions x, y and z?     x y z  a fuel oil bitumen paraffin (kerosene)  b fuel oil paraffin (kerosene) bitumen  c paraffin (kerosene) bitumen fuel oil  d paraffin (kerosene) fuel oil bitumen     ",
            "15": "15  \u00a9 ucles 2010 0620/13/o/n/10  39 the diagram shows the structure of a compound.    h ch c hh ch o hh ch     to which classes of compound does this molecule belong?     alkane alkene alcohol  a no no no  b no yes yes  c yes no yes  d yes yes yes     40 which structures show compounds that are members of the same homologous series?    o ch hch hch hh h1 h ch hch hco o h2 h ch hch hc hh hc3 h ch hch hch hch ho h4     a 1 and 2  b  1 and 4  c  2 and 3 d 3 and 4     ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2010 0620/13/o/n/10   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w10_qp_21.pdf": {
            "1": "for examiner\u2019s use 1 2 3 total4 5 6 7 8read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 20. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 october/november 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 17 printed pages and 3 blank pages. [turn overib10 11_0620_21/4rp\u00a9 ucles 2010 *4308315385*",
            "2": "2 0620/21/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  the diagram below shows the elements in a period of the periodic table. li be b c n o f ne  (a)  to which period of the periodic table do these elements belong?   ... ..  [1]  (b)  answer these questions using only the elements shown in the diagram.  each element can be used once, more than once or not at all.  write down the symbol for the element which (i)  has six electrons in its outer shell. ...  (ii)  is a halogen. ...  (iii) is a metal which reacts rapidly with cold water. ...  (iv)  has two forms, graphite and diamond. ...  (v)  is in group ii of the periodic table. ...  (vi)  makes up about 80  % of the air. .  [6]  (c)  complete the following sentence using words from the list below.  atoms electrons molecules neutrons protons   the  of the elements in the periodic table are arranged in order of  increasing number of  . [2] [total: 9]",
            "3": "3 0620/21/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  calcium carbonate was heated strongly in a test-tube.  the gas given off was bubbled through limewater. heatcalcium carbonatelimewate r  (a)  what type of chemical reaction occurs when calcium carbonate is heated strongly?   put a ring around the correct answer. hydration neutralisation oxidation thermal decomposition [1]  (b) (i)   state the name of the gas given off when calcium carbonate is heated strongly.   . .  [1]  (ii)  state the colour change of the limewater.   . .  [1]  (c)  the product remaining in the test-tube is calcium oxide.  (i)  calcium oxide is used in steelmaking.  describe how and why calcium oxide is used in making steel.   . ...   . ...   . .  [2]  (ii)  steel is an alloy. what do you understand by the term alloy  ?   . ...   . .  [1]",
            "4": "4 0620/21/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (iii)  give one other use of calcium oxide.   . .  [1]  (iv)  complete the symbol equation for the reaction of calcium oxide with hydrochloric  acid.  cao  +  ...hc l  \u2192  cac l 2  +  ... [2]  (v)  state the chemical name of the compound cac l 2.   . .  [1] [total: 10]",
            "5": "5 0620/21/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use3  helium and argon are noble gases.  (a)  state one use of helium.   ... ..  [1]  (b)  the atomic structures of helium and argon are shown below. x helium argon  (i)  state the name of the central part of the atom, labelled x.   . .  [1]  (ii)  which statement about helium and argon is correct?  tick one box.  argon has an incomplete inner shell of electrons. an atom of argon has 16 electrons. helium has a complete outer shell of electrons. helium has an incomplete outer shell of electrons. [1]  (iii)  how many protons are there in an atom of argon?   . .  [1]  (iv) the symbol for a particular isotope of helium is written as         .  write a similar symbol for the isotope of argon which has 16 neutrons. [1]he4 2",
            "6": "6 0620/21/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (c)  argon is a liquid at a temperature of \u2013188  \u00b0c.   complete the diagram below to show how the atoms of argon are arranged at \u2013188  \u00b0c.          represents one atom of argon. [2] [total: 7]",
            "7": "7 0620/21/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use4  the table shows the mass of some ions present in a 500  cm3 bottle of mineral water. name of ion symbolmass of ion / mg calcium ca2+40.5 cl \u20138.1 magnesium mg2+11.6 nitrate no3\u20132.4 potassium k+0.9 so42\u20136.4  (a)  state the name of the following ions.  c l \u2013  . ...  so42\u2013  ...  [2]  (b)  calculate the mass of magnesium ions in 100  cm3 of this mineral water. [1]  (c) (i)  describe a test for nitrate ions.   . ...   . .  [2]  (ii)  the gas produced in this test turns damp red litmus paper blue.   state the name of this gas.   . .  [1]",
            "8": "8 0620/21/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (d)  the apparatus shown is used to get pure water from impure mineral water. heatmineral water  (i)  complete the diagram by putting the correct labels in the three boxes. [3]  (ii)  describe how this apparatus separates pure water from dissolved ionic solids.   . ...   . ...   . .  [2]  (iii)  water purity is important in everyday life.  describe one other area of everyday life where purity of substances is important.   . .  [1] [total: 12]",
            "9": "9 0620/21/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  a solution of calcium hydroxide in water is alkaline.  (a)  which one of the ph values below is alkaline?  put a ring around the correct answer.  ph 3 ph 6 ph 7 ph 11  [1]  (b)  which of the following is the common name for calcium hydroxide?  tick one box.  cement limestone quicklime slaked lime [1]  (c)  some farmers use calcium hydroxide to control soil acidity.  (i)  why is it important to control soil acidity?   . .  [1]  (ii)  acid rain can cause soil to become acidic.  describe how acid rain is formed.   . ...   . ...   . ...   . .  [3]  (d)  calcium hydroxide reacts with hydrochloric acid. calcium hydroxide  +  hydrochloric acid  \u2192  calcium chloride  +  water  (i)  state the name of this type of chemical reaction.   . .  [1]",
            "10": "10 0620/21/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  a dilute solution of calcium hydroxide can be titrated with hydrochloric acid using the  apparatus shown. burette solution ofcalcium hydroxidehydrochloric acid flask  describe how you would carry out this titration.   . ...   . ...   . ...   . .  [3] [total: 10]",
            "11": "11 0620/21/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use6  iron is extracted from its ore by reduction with carbon. aluminium is extracted from its ore by  electrolysis.  (a) (i)   state the name of an ore of aluminium.   . .  [1]  (ii)  what do you understand by the term reduction  ?   . .  [1]  (iii)  suggest why aluminium is not extracted from its ore by reduction with carbon.   . .  [1]  (b)  the table gives information about the reduction of four different metal oxides by heating  with carbon. metal oxide reduction conditions lead( ii) oxide reduced very easily using a bunsen burner magnesium oxide reduced with dif \ufb01 culty in a furnace above 2000  \u00b0c nickel( ii) oxide reduced very easily in a furnace above 680  \u00b0c zinc oxide reduced fairly easily in a furnace above 1200  \u00b0c   use the information in the table to suggest the order of reactivity of these metals. least reactive most reactive [2]  (c)  zinc powder reacts with hydrochloric acid.   the speed of reaction can be followed by measuring the volume of hydrogen gas  produced per minute.  what happens to the volume of gas produced per minute when (i)  large lumps of zinc are used instead of zinc powder?   . .  [1]  (ii)  the reaction is carried out at a higher temperature?   . .  [1]",
            "12": "12 0620/21/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (d)  match the metals on the left with their uses on the right.  the \ufb01 rst one has been done for you. nickel electrical wiring copper making coins aluminium chemical plant mild steel car bodies stainless steel aircraft bodies [4] [total: 11]",
            "13": "13 0620/21/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use7  ethene, c2h4, is manufactured by cracking petroleum fractions.  (a) (i)   what do you understand by the term petroleum fraction  ?   . ...   . .  [1]  (ii)  complete the equation for the manufacture of ethene from dodecane, c12h26.  c12h26  \u2192  c2h4  +  ... [1]  (b)  two fractions obtained from the distillation of petroleum are re \ufb01 nery gas and gasoline.   state one use of each of these fractions.  re \ufb01 nery gas   ...  gasoline . ..  [2]  (c)  ethene is an unsaturated hydrocarbon.  what do you understand by the following terms?  unsaturated  ...  hydrocarbon    [2]  (d)  ethene is used to make ethanol.  (i)  which of these reactions is used to make ethanol from ethene?  tick one box.  catalytic addition of steam fermentation oxidation using oxygen reduction using hydrogen [1]",
            "14": "14 0620/21/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  draw the structure of ethanol showing all atoms and bonds. [2]  (e)  ethene is used to make poly(ethene).  complete the following sentences about this reaction. use words from the list below.  additions carbohydrates catalysts monomers polymers  the ethene molecules which join to form poly(ethene) are the ... . the poly(ethene) molecules formed are ... . [2] [total: 11]",
            "15": "15 0620/21/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use8  lead( ii) bromide can be electrolysed using the apparatus shown below. heat+\u2013graphite rod ceramic crucible lead( ii) bromidegraphite rod  (a)  choose one word from the list below which describes the graphite rods.  put a ring around the correct answer.  cations electrodes electrons insulators metals  [1]  (b)  state the name of the products formed during this electrolysis at  the negative graphite rod.  . the positive graphite rod.    [2]  (c)  which of the following conduct electricity?  tick two boxes.  ceramic crucible graphite rod molten lead( ii) bromide  solid lead( ii) bromide [2]",
            "16": "16 0620/21/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (d)  the structure of lead( ii) bromide is shown below. br \u2013 br \u2013br \u2013 br \u2013pb2+ pb2+pb2+ pb2+br \u2013 br \u2013br \u2013 br \u2013 br \u2013br \u2013br \u2013br \u2013pb2+ pb2+  write the simplest formula for lead( ii) bromide.   ... ..  [1]  (e)  lead( ii) bromide is formed as a precipitate when aqueous solutions of lead( ii) nitrate  and potassium bromide are mixed.  (i)  what do you understand by the term precipitate  ?   . ...   . .  [1]  (ii)  the formula of lead( ii) nitrate is pb(no3)2.  state the number of different types of atom present in this formula.   . .  [1]  (iii)  state the total number of oxygen atoms present in this formula.   . .  [1]  (iv)  lead compounds are pollutants in the air.  state one harmful effect of lead compounds on health.   . .  [1] [total: 10]",
            "17": "17 0620/21/o/n/10blank page \u00a9 ucles 2010",
            "18": "18 0620/21/o/n/10blank page \u00a9 ucles 2010",
            "19": "19 0620/21/o/n/10blank page \u00a9 ucles 2010",
            "20": "20 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/21/o/n/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w10_qp_22.pdf": {
            "1": "for examiner\u2019s use 1 2 3 total4 5 6 7read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 october/november 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib10 11_0620_22/4rp\u00a9 ucles 2010 *5310008024*",
            "2": "2 0620/22/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  choose from the following list of oxides to answer the questions below.   you can use each oxide once, more than once or not at all. carbon dioxide carbon monoxide magnesium oxide nitrogen dioxide sulfur dioxide water  (a)  which one of these oxides is a basic oxide?   ... ..  [1]  (b)  which two oxides cause acid rain?  .  and  . [2]  (c)  which two oxides are formed when a hydrocarbon undergoes complete combustion?  .  and  . [2] (d)  which one of these oxides turns white copper( ii) sulfate blue?   ... ..  [1]  (e)  which oxide is formed when calcium carbonate undergoes thermal decomposition?   ... ..  [1] [total: 7]",
            "3": "3 0620/22/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  the diagram shows the structure of some compounds containing iodine. cl cl clii\u2013 na+na+na+na+ na+na+ i\u2013i\u2013i\u2013 i\u2013i\u2013abc i hd iio oo oo  (a) (i)  what do you understand by the term compound  ?   . ...   . .  [1]  (ii) which one of these compounds, a, b, c or d, has a high melting point?  explain your answer.  compound  .. explanation  ..  [2] (iii)  which one of these compounds is similar in structure to hydrogen chloride?   . .  [1]  (b)  compound b is sodium iodide.  (i)  which statement about the electrical conductivity of sodium iodide is correct?  tick one box.  it conducts electricity when molten. it conducts electricity when solid. it does not conduct electricity when molten. it does not conduct electricity in aqueous solution. [1]  (ii)  describe a test for iodide ions.  test   .  result    [2]  (c)  compound d is iodine( v) oxide. it is an acidic oxide.  suggest why iodine( v) oxide is an acidic oxide.   ... ..  [1] [total: 8]",
            "4": "4 0620/22/o/n/10 \u00a9 ucles 2010for examiner\u2019s use3  some properties of the group i elements are given in the table. elementmelting point / \u00b0cboiling point / \u00b0cdensity in g  / cm3 lithium 181 1342 0.53 sodium 98 883 0.97potassium 63 0.86rubidium 39 686 1.53caesium 29 669 1.88  (a) (i)   predict the boiling point of potassium.   . .  [1]  (ii)  which group i elements are liquids at 50  \u00b0c?   . .  [2]  (iii)  how, in general, does the density of the group i elements change down the group?   . .  [1]  (b)  complete the following sentences about the group i elements using words from the list  below.  crystallising decreases hard increases  melting similarity soft  the group i elements are relatively . metals which show a trend in . point and reaction with water.  the reactivity with water . down the group. [3]  (c)  the equation for the reaction of sodium with water is given below. 2na  + 2h 2o  \u2192  2naoh  +  h2  write a word equation for this reaction. [2]",
            "5": "5 0620/22/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (d)  chlorine reacts with sodium to form sodium chloride.  (i)  complete the equation for this reaction. ...na  +  c l 2  \u2192  ...nac l [2]  (ii)  chlorine is a diatomic gas.  what do you understand by the term diatomic  ?   . .  [1]  (iii)  describe the arrangement and motion of the molecules in chlorine gas.  arrangement  .. motion  ..  [2 ]  (iv)  draw a diagram to show the arrangement of the electrons in a molecule of  chlorine.   show only the outer electrons. [2] [total: 16]",
            "6": "6 0620/22/o/n/10 \u00a9 ucles 2010for examiner\u2019s use4  the formulae of four organic compounds are shown below. abc d cc ch hh hhh c h oo h ch hc h hh hch hc o h hh h  (a) (i)   state the name of the type of bonding between the atoms in these four  compounds.   . .  [1]  (ii)  which one of these compounds, a, b, c or d, is a saturated hydrocarbon?   . .  [1]  (iii)  which one of these compounds is acidic?   . .  [1]  (iv)  state the name of compound d.   . .  [1]  (v)  compound a contains a c=c double bond.  describe a test for a c=c double bond.  test   .  result    [2]  (b)  compound c is a member of the alkane homologous series.  (i)  state  two features of an homologous series.  1.  .. ..  2.  .. ..[2]  (ii)  state the formula and name of another alkane in the same homologous series as  compound c.  formula  name    [2 ]",
            "7": "7 0620/22/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  the alkanes present in petroleum can be separated by fractional distillation.  the diagram below shows a fractional distillation column.  (i)  on the diagram, label where the temperature in the column is the lowest.  mark this with the letter x. [1]  (ii)  on the diagram, label where the bitumen fraction is collected.  mark this with the letter y. [1] [total: 12]",
            "8": "8 0620/22/o/n/10 \u00a9 ucles 2010for examiner\u2019s use5  a student used the apparatus shown below to investigate the speed of reaction when large  lumps of zinc reacted with excess sulfuric acid. zinc  +  sulfuric acid  \u2192  zinc sulfate  +  hydrogen sulfuric acid zincgas syringe  (a)  as the reaction proceeds, describe what happens to  (i)  the mass of the zinc lumps.   . .  [1]  (ii)  the concentration of zinc sulfate in the solution in the \ufb02 ask.   . .  [1]",
            "9": "9 0620/22/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (b)   the student\u2019s results are shown below. time  / minutes 0 10 20 30 40 50 60 volume of hydrogen  / cm30 2 43 94 85 35 55 5  (i)  plot a graph of volume of hydrogen against time. use the axes below. 60 5040302010 0 0 1 02 03 04 05 06 0 time  / minutesvolume of hydrogen / cm3 [3]  (ii)  use your graph to calculate the volume of hydrogen given off after 25 minutes.  volume of hydrogen  .  [1] (iii)  explain why no more hydrogen was given off after 50 minutes.   . .  [1]  (iv)  describe a test for hydrogen.  test   .  result    [2]",
            "10": "10 0620/22/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (c)  what happens to the speed of the reaction when  (i)  smaller pieces of zinc are used?   . .  [1]  (ii)  some water is added to the sulfuric acid?   . .  [1]  (d)  the reaction between zinc and sulfuric acid is catalysed by copper( ii) sulfate solution.  what do you understand by the term catalyst  ?   ... ..  [1] [total: 12]",
            "11": "11 0620/22/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use6  iron is a transition element.  (a)  state three  properties of transition elements which are not shown by the group i  elements.  1.  ...   2.  ...   3.  ... ..  [3]  (b)  the symbols for two isotopes of iron are shown below.  (i)  how do these two isotopes differ in their atomic structure?   . .  [1]  (ii)  state the number of nucleons present in one atom of the isotope         .   . .  [1]  (iii)  how many electrons are there in one atom of the isotope         ?   . .  [1]  (c)  pure iron rusts very easily.  (i)  state the two conditions that are needed for rusting to take place.  1.  .. ..  2.  ..   [2]  (ii)  describe and explain one method of preventing rusting.  method  .. .  explain why this method works  ..  . .  [2]fe57 26 fe5726fe5426 fe5426",
            "12": "12 0620/22/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (d)  in the blast furnace, iron( iii) oxide reacts with carbon monoxide. fe2o3  +  3co  \u2192  2fe  +  3co2   which substance gets reduced in this reaction?  explain your answer.  substance  ... ..  explanation  . ..   ... ..  [2]  (e) (i)   carbon monoxide is a pollutant gas produced in motor car engines.   explain why carbon monoxide is formed.   . .  [1]  (ii)  state one harmful effect of carbon monoxide.   . .  [1] [total: 14]",
            "13": "13 0620/22/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use7  boric acid is an acid. urea is a base. both compounds are crystalline.   a student placed some crystals of boric acid and urea in a large beaker of water. the ph  value of the water at the start of the experiment was ph 7. water boric acid ureaa b  (a)  after 15 minutes the ph at point a in the beaker was ph 6.2.  (i)  suggest why the ph at point a had decreased.   . .  [1]  (ii)  what was the most likely ph at point b in the beaker after 15 minutes?   put a ring around the correct answer.  ph 1 ph 6 ph 7 ph 8  [1]  (iii)  the particles of boric acid and urea diffuse throughout the solution.   what do you understand by the term diffusion  ?   . ...   . .  [1]  (iv)  after 24 hours the ph throughout the whole solution was ph 7.   use your knowledge of acids and alkalis to explain why the ph returned to ph 7.   . ...   . .  [1]  (b)  the structure of urea is shown below. h2nn h2c o  (i)  write the simplest formula for urea. [1]",
            "14": "14 0620/22/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  calculate the relative molecular mass of urea.   use your periodic table to help you. [1]  (c)  urea is used as a fertiliser.  (i)  which element present in urea is an essential part of most fertilisers?   . .  [1]  (ii)  explain why farmers put fertilisers on their \ufb01 elds.   . ...   . .  [2]  (d)  describe how you can obtain pure, dry crystals of urea from an aqueous solution of  urea.   ...    ...    ... ..  [2] [total: 11]",
            "15": "15 0620/22/o/n/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/22/o/n/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w10_qp_23.pdf": {
            "1": "for examiner\u2019s use 1 2 3 total4 5 6 7read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/23   paper 2 october/november 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib10 11_0620_23/fp\u00a9 ucles 2010 *7888284667*",
            "2": "2 0620/23/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  choose from the following list of oxides to answer the questions below.   you can use each oxide once, more than once or not at all. carbon dioxide carbon monoxide magnesium oxide nitrogen dioxide sulfur dioxide water  (a)  which one of these oxides is a basic oxide?   ... ..  [1]  (b)  which two oxides cause acid rain?  .  and  . [2]  (c)  which two oxides are formed when a hydrocarbon undergoes complete combustion?  .  and  . [2] (d)  which one of these oxides turns white copper( ii) sulfate blue?   ... ..  [1]  (e)  which oxide is formed when calcium carbonate undergoes thermal decomposition?   ... ..  [1] [total: 7]",
            "3": "3 0620/23/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  the diagram shows the structure of some compounds containing iodine. cl cl clii\u2013 na+na+na+na+ na+na+ i\u2013i\u2013i\u2013 i\u2013i\u2013abc i hd iio oo oo  (a) (i)  what do you understand by the term compound  ?   . ...   . .  [1]  (ii) which one of these compounds, a, b, c or d, has a high melting point?  explain your answer.  compound  .. explanation  ..  [2] (iii)  which one of these compounds is similar in structure to hydrogen chloride?   . .  [1]  (b)  compound b is sodium iodide.  (i)  which statement about the electrical conductivity of sodium iodide is correct?  tick one box.  it conducts electricity when molten. it conducts electricity when solid. it does not conduct electricity when molten. it does not conduct electricity in aqueous solution. [1]  (ii)  describe a test for iodide ions.  test   .  result    [2]  (c)  compound d is iodine( v) oxide. it is an acidic oxide.  suggest why iodine( v) oxide is an acidic oxide.   ... ..  [1] [total: 8]",
            "4": "4 0620/23/o/n/10 \u00a9 ucles 2010for examiner\u2019s use3  some properties of the group i elements are given in the table. elementmelting point / \u00b0cboiling point / \u00b0cdensity in g  / cm3 lithium 181 1342 0.53 sodium 98 883 0.97potassium 63 0.86rubidium 39 686 1.53caesium 29 669 1.88  (a) (i)   predict the boiling point of potassium.   . .  [1]  (ii)  which group i elements are liquids at 50  \u00b0c?   . .  [2]  (iii)  how, in general, does the density of the group i elements change down the group?   . .  [1]  (b)  complete the following sentences about the group i elements using words from the list  below.  crystallising decreases hard increases  melting similarity soft  the group i elements are relatively . metals which show a trend in . point and reaction with water.  the reactivity with water . down the group. [3]  (c)  the equation for the reaction of sodium with water is given below. 2na  + 2h 2o  \u2192  2naoh  +  h2  write a word equation for this reaction. [2]",
            "5": "5 0620/23/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (d)  chlorine reacts with sodium to form sodium chloride.  (i)  complete the equation for this reaction. ...na  +  c l 2  \u2192  ...nac l [2]  (ii)  chlorine is a diatomic gas.  what do you understand by the term diatomic  ?   . .  [1]  (iii)  describe the arrangement and motion of the molecules in chlorine gas.  arrangement  .. motion  ..  [2 ]  (iv)  draw a diagram to show the arrangement of the electrons in a molecule of  chlorine.   show only the outer electrons. [2] [total: 16]",
            "6": "6 0620/23/o/n/10 \u00a9 ucles 2010for examiner\u2019s use4  the formulae of four organic compounds are shown below. abc d cc ch hh hhh c h oo h ch hc h hh hch hc o h hh h  (a) (i)   state the name of the type of bonding between the atoms in these four  compounds.   . .  [1]  (ii)  which one of these compounds, a, b, c or d, is a saturated hydrocarbon?   . .  [1]  (iii)  which one of these compounds is acidic?   . .  [1]  (iv)  state the name of compound d.   . .  [1]  (v)  compound a contains a c=c double bond.  describe a test for a c=c double bond.  test   .  result    [2]  (b)  compound c is a member of the alkane homologous series.  (i)  state  two features of an homologous series.  1.  .. ..  2.  .. ..[2]  (ii)  state the formula and name of another alkane in the same homologous series as  compound c.  formula  name    [2 ]",
            "7": "7 0620/23/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  the alkanes present in petroleum can be separated by fractional distillation.  the diagram below shows a fractional distillation column.  (i)  on the diagram, label where the temperature in the column is the lowest.  mark this with the letter x. [1]  (ii)  on the diagram, label where the bitumen fraction is collected.  mark this with the letter y. [1] [total: 12]",
            "8": "8 0620/23/o/n/10 \u00a9 ucles 2010for examiner\u2019s use5  a student used the apparatus shown below to investigate the speed of reaction when large  lumps of zinc reacted with excess sulfuric acid. zinc  +  sulfuric acid  \u2192  zinc sulfate  +  hydrogen sulfuric acid zincgas syringe  (a)  as the reaction proceeds, describe what happens to  (i)  the mass of the zinc lumps.   . .  [1]  (ii)  the concentration of zinc sulfate in the solution in the \ufb02 ask.   . .  [1]",
            "9": "9 0620/23/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (b)   the student\u2019s results are shown below. time  / minutes 0 10 20 30 40 50 60 volume of hydrogen  / cm30 2 43 94 85 35 55 5  (i)  plot a graph of volume of hydrogen against time. use the axes below. 60 5040302010 0 0 1 02 03 04 05 06 0 time  / minutesvolume of hydrogen / cm3 [3]  (ii)  use your graph to calculate the volume of hydrogen given off after 25 minutes.  volume of hydrogen  .  [1] (iii)  explain why no more hydrogen was given off after 50 minutes.   . .  [1]  (iv)  describe a test for hydrogen.  test   .  result    [2]",
            "10": "10 0620/23/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (c)  what happens to the speed of the reaction when  (i)  smaller pieces of zinc are used?   . .  [1]  (ii)  some water is added to the sulfuric acid?   . .  [1]  (d)  the reaction between zinc and sulfuric acid is catalysed by copper( ii) sulfate solution.  what do you understand by the term catalyst  ?   ... ..  [1] [total: 12]",
            "11": "11 0620/23/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use6  iron is a transition element.  (a)  state three  properties of transition elements which are not shown by the group i  elements.  1.  ...   2.  ...   3.  ... ..  [3]  (b)  the symbols for two isotopes of iron are shown below.  (i)  how do these two isotopes differ in their atomic structure?   . .  [1]  (ii)  state the number of nucleons present in one atom of the isotope         .   . .  [1]  (iii)  how many electrons are there in one atom of the isotope         ?   . .  [1]  (c)  pure iron rusts very easily.  (i)  state the two conditions that are needed for rusting to take place.  1.  .. ..  2.  ..   [2]  (ii)  describe and explain one method of preventing rusting.  method  .. .  explain why this method works  ..  . .  [2]fe57 26 fe5726fe5426 fe5426",
            "12": "12 0620/23/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (d)  in the blast furnace, iron( iii) oxide reacts with carbon monoxide. fe2o3  +  3co  \u2192  2fe  +  3co2   which substance gets reduced in this reaction?  explain your answer.  substance  ... ..  explanation  . ..   ... ..  [2]  (e) (i)   carbon monoxide is a pollutant gas produced in motor car engines.   explain why carbon monoxide is formed.   . .  [1]  (ii)  state one harmful effect of carbon monoxide.   . .  [1] [total: 14]",
            "13": "13 0620/23/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use7  boric acid is an acid. urea is a base. both compounds are crystalline.   a student placed some crystals of boric acid and urea in a large beaker of water. the ph  value of the water at the start of the experiment was ph 7. water boric acid ureaa b  (a)  after 15 minutes the ph at point a in the beaker was ph 6.2.  (i)  suggest why the ph at point a had decreased.   . .  [1]  (ii)  what was the most likely ph at point b in the beaker after 15 minutes?   put a ring around the correct answer.  ph 1 ph 6 ph 7 ph 8  [1]  (iii)  the particles of boric acid and urea diffuse throughout the solution.   what do you understand by the term diffusion  ?   . ...   . .  [1]  (iv)  after 24 hours the ph throughout the whole solution was ph 7.   use your knowledge of acids and alkalis to explain why the ph returned to ph 7.   . ...   . .  [1]  (b)  the structure of urea is shown below. h2nn h2c o  (i)  write the simplest formula for urea. [1]",
            "14": "14 0620/23/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  calculate the relative molecular mass of urea.   use your periodic table to help you. [1]  (c)  urea is used as a fertiliser.  (i)  which element present in urea is an essential part of most fertilisers?   . .  [1]  (ii)  explain why farmers put fertilisers on their \ufb01 elds.   . ...   . .  [2]  (d)  describe how you can obtain pure, dry crystals of urea from an aqueous solution of  urea.   ...    ...    ... ..  [2] [total: 11]",
            "15": "15 0620/23/o/n/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/23/o/n/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w10_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) october/november 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib10 11_0620_31/3rp\u00a9 ucles 2010 *5805031630* for examiner\u2019s use 3 4 5 total6 7 81 2",
            "2": "2 0620/31/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  the table gives the composition of three particles. particlenumber of protonsnumber of electronsnumber of neutrons a 15 15 16 b 15 18 16 c 15 15 17  (a)  what is the evidence in the table for each of the following?  (i)  particle a is an atom.  .. ..  ..    [1]  (ii)  they are all particles of the same element.  .. ..  ..    [1]  (iii)  particle b is a negative ion.  .. ..  ..    [2]  (iv)  particles a and c are isotopes.  .. ..  ..    [2]  (b)  (i)  what is the electronic structure of particle a?  ..    [1]  (ii)  what is the valency of the element?  ..    [1]  (iii)  is the element a metal or a non-metal? give a reason for your choice.  .. ..  ..    [1] [total: 9]",
            "3": "3 0620/31/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  about 4000 years ago the bronze age started in britain. bronze is an alloy of copper and  tin.  (a) (i)   suggest a reason why a bronze axe was better than a copper axe.  ..    [1]  (ii)  brass is another copper alloy. name the other metal in brass.  ..    [1]  (b)  the diagram below shows the arrangement of particles in a pure metal.  (i)  what is the name given to a regular arrangement of particles in a crystalline solid?  ..    [1]  (ii)  draw a diagram which shows the arrangement of particles in an alloy. [2]  (iii)  explain the term malleable .  ..    [1]  (iv)  why are metals malleable?  .. ..  ..    [2]",
            "4": "4 0620/31/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (c)   the common ore of tin is tin( iv) oxide and an ore of copper is malachite, cuco3.cu(oh)2.  (i)  write a word equation for the reduction of tin( iv) oxide by carbon.  ..   [1]  (ii)  malachite is heated to form copper oxide and two other chemicals.   name these chemicals.  ...  and  .  [ 2]  (iii)  copper oxide is reduced to copper which is then re \ufb01 ned by electrolysis.   label the diagram of the apparatus which could be used to re \ufb01 ne copper. \u2013 +power supply [3]  (iv)  give one use of copper, other than making alloys.   . .  [1] [total: 15]",
            "5": "5 0620/31/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use3  the diagram shows a cell. this is a device which produces electrical energy. the reaction in  a cell is a redox reaction and involves electron transfer. filter paper soaked in sodium chloride solution to complete the circuitsolution of bromine br2(aq)solution of iron( ii) salt fe2+(aq)inert electrode inert electrodev+ \u2013  (i)  complete the sentence.   a cell will change  energy into electrical energy. [1]  (ii)  draw an arrow on the diagram to show the direction of the electron \ufb02 ow. [1]  (iii)  in the left hand beaker, the colour changes from brown to colourless.   complete the equation for the reaction. br2  +  ...  \u2192  ... [2]  (iv)  is the change in (iii) oxidation or reduction? give a reason for your choice.   . ...   . .  [1]  (v)  complete the following description of the reaction in the right hand beaker.  fe2+ changes into . . [1]  (vi)  when a solution of bromine is replaced by a solution of chlorine, the voltage  increases. when a solution of bromine is replaced by a solution of iodine, the voltage decreases.   suggest an explanation for this difference.   . ...   . .  [1] [total: 7]",
            "6": "6 0620/31/o/n/10 \u00a9 ucles 2010for examiner\u2019s use4  ammonia is an important industrial chemical.  (a)  (i)  give the electron structure of an atom of nitrogen.   . .  [1]  (ii)  use this electronic structure, rather than the valency of nitrogen, to explain why the  formula of ammonia is nh3 not nh4.   . ...   . ...   . .  [2]  (b)  ammonia is made by the haber process.  n2(g)  + 3h2(g)    2nh3(g)   forward reaction is exothermic   the percentage of ammonia in the equilibrium mixture varies with conditions. pressure  / atmospheres 100 200 300 400 % ammonia at 300  \u00b0c 4 56 57 27 8 % ammonia at 500  \u00b0c 9 18 25 31   the conditions actually used are 200 atmospheres, 450  \u00b0c and an iron catalyst.  (i)  the original catalyst was platinum. suggest a reason why it was changed to iron.   . .  [1]  (ii)  explain why the highest pressure gives the highest percentage of ammonia in the  equilibrium mixture.   . ...   . .  [2]  (iii)  what happens to the unreacted nitrogen and hydrogen?   . ...   . .  [1]",
            "7": "7 0620/31/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (iv)  state one advantage and one disadvantage of using a lower temperature.  advantage   .  . .  [1]  disadvantage     . .  [1] [total: 9]",
            "8": "8 0620/31/o/n/10 \u00a9 ucles 2010for examiner\u2019s use5  monomers polymerise to form polymers or macromolecules.  (a) (i)  explain the term polymerise .   . ...   . .  [1]  (ii)  there are two types of polymerisation - addition and condensation. what is the  difference between them?   . ...   . ...   . .  [2]  (b)  an important monomer is chloroethene which has the structural formula shown below. cch clh h  it is made by the following method. c2h4  +  c l 2  \u2192  c2h4 cl 2   dichloroethane  this is heated to make chloroethene. c2h4cl 2  \u2192  c2h3cl   +  hc l   (i)  ethene is made by cracking alkanes. complete the equation for cracking  dodecane. c12h26  \u2192    +  2c2h4 [1]  another method of making dichloroethane is from ethane. c2h6  +  2c l 2   \u2192  c2h4cl 2   +  2hc l  (ii)  suggest a reason why the method using ethene is preferred.   . ...   . .  [1]  (iii)  describe an industrial method of making chlorine.   . ...   . .  [2]",
            "9": "9 0620/31/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (iv)  draw the structural formula of poly(chloroethene).   include three monomer units. [2] [total: 9]",
            "10": "10 0620/31/o/n/10 \u00a9 ucles 2010for examiner\u2019s use6  the table below shows the elements in the second period of the periodic table and some of  their oxidation states in their most common compounds. element li be b c n o f ne number of outer electrons 12345678 oxidation state +1 +2 +3 +4 \u20133 \u20132 \u20131 0  (a) (i)  what does it mean when the only oxidation state of an element is zero?   . ...   . .  [1]  (ii)  explain why some elements have positive oxidation states but others have negative  ones.   . ...   . .  [2]  (iii)  select two elements in the table which exist as diatomic molecules of the type x2.   . .  [1]  (b)  beryllium hydroxide, a white solid, is an amphoteric hydroxide.  (i)  name another metal which has an amphoteric hydroxide.   . .  [1]  (ii)   suggest what you would observe when an excess of aqueous sodium hydroxide is  added gradually to aqueous beryllium sulfate.   . ...   . .  [2]  (c) (i)  give the formulae of lithium \ufb02 uoride and nitrogen \ufb02 uoride.  lithium \ufb02 uoride   ..  nitrogen \ufb02 uoride   ..  [2]",
            "11": "11 0620/31/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (ii)  predict two differences in their properties.   . ...   . .  [2]  (iii)  explain why these two \ufb02 uorides have different properties.   . ...   . .  [2] [total: 13]",
            "12": "12 0620/31/o/n/10 \u00a9 ucles 2010for examiner\u2019s use7  the diagram shows part of the carbon cycle. this includes some of the processes which  determine the percentage of carbon dioxide in the atmosphere. carbon dioxide in the atmosphere photosynthesiscombustion respiration  (i)  carbon dioxide is one greenhouse gas. name another one.   . .  [1]  (ii)  explain the term respiration  and how this process increases the percentage of  carbon dioxide in the atmosphere.   . ...   . ...   . .  [3]  (iii)  explain why the combustion of waste crop material should not alter the percentage  of carbon dioxide in the atmosphere.   . ...   . .  [2]  (iv)  in 1960 the percentage of carbon dioxide in the atmosphere was 0.032% and in  2008 it was 0.038%. suggest an explanation for this increase.   . ...   . .  [2] [total: 8]",
            "13": "13 0620/31/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use8  soluble salts can be made using a base and an acid.  (a)  complete this method of preparing dry crystals of the soluble salt   cobalt( ii) chloride-6-water from the insoluble base cobalt( ii) carbonate.  step 1  add an excess of cobalt( ii) carbonate to hot dilute hydrochloric acid.  step 2   ...    ...   step 3   ...    ...   step 4   ...    ... ..  [4]",
            "14": "14 0620/31/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (b)  6.0  g of cobalt( ii) carbonate was added to 40  cm3 of hydrochloric acid, concentration 2.0  mol  / dm3. calculate the maximum yield of cobalt( ii) chloride-6-water and show that  the cobalt( ii) carbonate was in excess. coco3  + 2hc l  \u2192  coc l 2  +  co2  +  h2o coc l 2  +  6h2o  \u2192  coc l 2.6h2o  maximum yield  number of moles of hc l used = .  number of moles of coc l 2 formed = .  number of moles of coc l 2.6h2o formed = .  mass of one mole of coc l 2.6h2o = 238  g  maximum yield of coc l 2.6h2o = . g [4]  to show that cobalt( ii) carbonate is in excess  number of moles of hc l used = . (use value from above)  mass of one mole of coco3 = 119  g  number of moles of coco3 in 6.0  g of cobalt( ii) carbonate = . [1]  explain why cobalt( ii) carbonate is in excess   .   ... ..  [1] [total: 10]",
            "15": "15 0620/31/o/n/10blank page",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/31/o/n/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w10_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) october/november 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib10 11_0620_32/2rp\u00a9 ucles 2010 *7061419556* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/32/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  the following table gives information about six substances. substancemelting point / \u00b0cboiling point / \u00b0celectrical conductivity  as a solidelectrical conductivity  as a liquid a 839 1484 good good b \u2013210 \u2013196 poor poor c 776 1497 poor goodd \u2013117 78 poor poor e 1607 2227 poor poor f \u20135 102 poor good  (a)  which substance could have a macromolecular structure, similar to that of silicon( iv)  oxide?   ... ..  [1]  (b)  which substances are solids at room temperature?   ... ..  [1]  (c)  which substance could be a metal?   ... ..  [1]  (d)  which substance could be aqueous sodium chloride?   ... ..  [1]  (e)  which substance is an ionic compound?   ... ..  [1]  (f)  which substances are liquids at room temperature?   ... ..  [1] [total: 6]",
            "3": "3 0620/32/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  an ore of the important metal zinc is zinc blende, zns. this is changed into zinc oxide which  is reduced to the impure metal by carbon reduction.  (a)  (i)  how is zinc oxide obtained from zinc sul \ufb01 de?   . ...   . .  [2]  (ii)  write a balanced equation for the reduction of zinc oxide by carbon.   . .  [1]  (iii)  the major impurity in the zinc is cadmium. the boiling point of zinc is 907  \u00b0c and that  of cadmium is 767  \u00b0c.   name a technique which could be used to separate these two metals.   . .  [2]  (b)  in common with most metals, zinc is a good conductor of electricity. it is used as an  electrode in cells.  (i)  give two other uses of zinc.   . ...   . .  [2]  (ii)  describe the metallic bonding in zinc and then explain why it is a good conductor of  electricity.   . ...   . ...   . ...   . .  [4] [total: 11]",
            "4": "4 0620/32/o/n/10 \u00a9 ucles 2010for examiner\u2019s use3  the decomposition of hydrogen peroxide is catalysed by manganese( iv) oxide. 2h2o2(aq)  \u2192  2h2o(l)  +  o2(g)   to 50  cm3 of aqueous hydrogen peroxide, 0.50  g of manganese( iv) oxide was added. the  volume of oxygen formed was measured every 20 seconds. the average reaction rate was calculated for each 20 second interval. time  / s 0 20 40 60 80 100 volume of oxygen  / cm30 4 87 08 28 88 8 average reaction rate in cm3 / s 2.4 1.1 . 0.3 0.0 0.0  (a)  explain how the average reaction rate, 2.4  cm3 / s, was calculated for the \ufb01 rst 20  seconds.   ...    ... ..  [2]  (b)  complete the table. [1]  (c)  explain why the average reaction rate decreases with time.   ...    ... ..  [2]  (d)  the experiment was repeated but 1.0  g of manganese( iv) oxide was added.   what effect, if any, would this have on the reaction rate and on the \ufb01 nal volume of oxygen?  give a reason for each answer.  effect on rate  .. .  [1]  reason  ...   ... ..  [2]  effect on \ufb01 nal volume of oxygen  .  [1]  reason  ...   ... ..  [2] [total: 11]",
            "5": "5 0620/32/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use4  chromium is a transition element.  (a) (i)   predict two differences in the physical properties of chromium and sodium.   . ...   . .  [2]  (ii)  predict two differences in the chemical properties of chromium and sodium.   . ...   . ...   . .  [2]  (b)  chromium is used to electroplate steel objects. the diagram shows how this could be  done. lead anode+\u2013 object to be plated chromium( iii) sulfate(aq)add more chromium( iii) sulfate(aq)  (i)  give two reasons why steel objects are plated with chromium.   . ...   . .  [2]  (ii)  the formula of the chromium( iii) ion is cr3+ and of the sulfate ion is so42\u2013. give the  formula of chromium( iii) sulfate.   . .  [1]  (iii)  write the equation for the reaction at the negative electrode (cathode).   . .  [2]  (iv)  a colourless gas, which relights a glowing splint, is formed at the positive electrode  (anode). name this gas.   . .  [1]",
            "6": "6 0620/32/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (v)  during electrolysis, it is necessary to add more chromium( iii) sulfate but during  copper-plating using a copper anode, it is not necessary to add more copper( ii)  sulfate. explain.   . ...   . ...   . .  [2] [total: 12]",
            "7": "7 0620/32/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  in the absence of oxygen, certain bacteria decompose carbohydrates to biogas. this is a  mixture of gases mainly methane and carbon dioxide.   biogas is becoming an increasingly important fuel around the world.   a diagram of a simple biogas generator is given below. typically, it contains biomass - animal  manure, plant material etc. biogas biomass added waste material removed  (a) (i)  what is meant by the term carbohydrate ?   . ...   . .  [2]  (ii)  the reaction in the generator is an example of anaerobic respiration.   anaerobic means in the absence of oxygen. what does respiration  mean?   . ...   . .  [2]  (iii)  the generator must produce some carbon dioxide.   why is it impossible for it to produce only a hydrocarbon such as methane?   . .  [1]  (iv)  suggest a use for the nitrogen-rich solid removed from the generator.   . .  [1]",
            "8": "8 0620/32/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (b) (i)  in an experiment, a 60  cm3 sample of biogas required 80  cm3 of oxygen for the  complete combustion of the methane in the sample.   calculate the percentage of methane in the sample of biogas. assume that biogas  contains only methane and carbon dioxide. ch4  +  2o2  \u2192  co2  +  2h2o   . ...   . ...   . .  [2]  (ii)  carbon dioxide is acidic and methane is neutral.  suggest another way of measuring the volume of methane in the sample.   . ...   . .  [2] [total: 10]",
            "9": "9 0620/32/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use6  the alcohols form an homologous series.  (a)  give three  characteristics of an homologous series.   ...    ...    ...    ... ..  [3]  (b)  the following two alcohols are members of the series and they are isomers. ch3 \u2014 ch2 \u2014 ch2 \u2014 ch2 \u2014 oh     and     (ch3)2ch  \u2014 ch2oh  (i)  explain why they are isomers.   . ...   . ...   . .  [2]  (ii)  give the structural formula of another alcohol which is also an isomer of these  alcohols. [1]",
            "10": "10 0620/32/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (c)  copper( ii) oxide can oxidise butan-1-ol to liquid x whose ph is 4. liquid x formed by oxidation of butan-1-ol.heatmineral wool soaked in butan-1-ol copper( ii) oxide  (i)  name another reagent which can oxidise butan-1-ol.   . .  [1]  (ii)  what type of compound is liquid x and what is its formula?  type of compound   ...  [1] formula of liquid x   [1]",
            "11": "11 0620/32/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (d)  the alcohol ethanol can be made by fermentation. yeast is added to aqueous glucose. c6h12o6(aq)  \u2192  2c2h5oh(aq)  +  2co2(g)   carbon dioxide is given off and the mixture becomes warm as the reaction is exothermic.  the graph shows how the rate of reaction varies over several days. rate ofreaction time  (i)  suggest a method of measuring the rate of this reaction.   . ...   . .  [2]  (ii)  why does the rate increase initially?   . ...   . .  [1]  (iii)  suggest two reasons why the rate eventually decreases.   . ...   . .  [2]  (iv)  why is fermentation carried out in the absence of air?   . ...   . .  [1] [total: 15]",
            "12": "12 0620/32/o/n/10 \u00a9 ucles 2010for examiner\u2019s use7  the major use of sulfur dioxide is to manufacture sulfuric acid.  (a) (i)  another use of sulfur dioxide is as the food additive e220.  how does it preserve food?   . ...   . .  [1]  (ii)  why is sulfur dioxide used in the manufacture of wood pulp?   . .  [1]  (iii)  how is sulfur dioxide manufactured?   . .  [1]  (b)  complete the following description of the manufacture of sulfuric acid.  sulfur dioxide reacts with .. to form sulfur trioxide. the above reaction is catalysed by . . the optimum temperature for this reaction is .. \u00b0c. sulfur trioxide needs to react with .. to form sulfuric acid. [4]  (c) (i)  de\ufb01 ne the term acid.   . .  [1]  (ii)  sulfuric acid is a strong acid. ethanedioic acid is a weak acid.   given solutions of both acids, how could you show that sulfuric acid is a strong acid  and ethanedioic acid is a weak acid?  method   . .   . .  [1]  result for each acid   ...  . .  [1]",
            "13": "13 0620/32/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (d)  20.0  cm3 of sulfuric acid, concentration 0.30  mol  / dm3, was added to 40  cm3 of sodium  hydroxide, concentration 0.20  mol  / dm3. 2naoh  +  h2so4  \u2192  na2so4  +  2h2o  (i)  how many moles of h2so4 were added? ..   [1]  (ii)  how many moles of naoh were used? .. [1]  (iii)  which reagent is in excess? give a reason for your choice.  reagent in excess   ...  [1] reason   . ..   . .  [1]  (iv)  is the ph of the \ufb01 nal mixture less than 7, equal to 7 or more than 7?   . .  [1] [total: 15]",
            "14": "14 0620/32/o/n/10blank page \u00a9 ucles 2010",
            "15": "15 0620/32/o/n/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/32/o/n/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w10_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) october/november 2010  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib10 11_0620_33/3rp\u00a9 ucles 2010 *2824794606* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/33/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  the diagrams below show the electron arrangement in two compounds. k+\u2013hho cl  (a)   in a water molecule, each hydrogen atom is bonded to the oxygen atom by sharing a pair  of electrons.   why does an oxygen atom share two pairs of electrons rather than just one pair?   ...    ... ..  [1]  (b) describe how a potassium atom becomes a potassium ion.   ... ..  [1]  (c)  why is there a bond between the ions in potassium chloride?   ...    ... ..  [1]  (d)  solid potassium chloride is a poor conductor of electricity. when dissolved in water it is a good conductor. explain.   ...    ... ..  [2] [total: 5]",
            "3": "3 0620/33/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  vanadium is a transition element.  (a)  an atom of the most common isotope of vanadium can be represented as       .   complete the following table to show the number of protons, electrons and neutrons in  each particle. particlenumber of protonsnumber of electronsnumber of neutrons v51 23 v51 3+23 v5023 [3]  (b)  the major use of vanadium is to make vanadium steel alloys.  (i)  explain the phrase steel alloys .   . ...   . .  [2]  (ii)  state the name and use of another steel alloy.  name   ..  use  ...  [2]  (c)  two of the oxidation states of vanadium are +3 and +4.  (i)  write the formula of vanadium( iii) oxide and of vanadium( iv) oxide.  vanadium( iii) oxide  ...  vanadium( iv) oxide  .  [2]  (ii)  vanadium( iii) oxide is basic and vandium( iv) oxide is amphoteric.   describe how you would obtain a sample of vanadium( iii) oxide from a mixture of  these two oxides.   . ...   . ...   . .  [3] [total: 12]v5123",
            "4": "4 0620/33/o/n/10 \u00a9 ucles 2010for examiner\u2019s use3  the reactions of a metal and the thermal stability of some of its compounds are determined  by the position of the metal in the reactivity series.  (a)  to \ufb01 nd the order of reactivity of the metals, cobalt, magnesium, silver and tin, the following  experiments were carried out. experiment result tin plus silver( i) nitrate solution silvery layer on tin magnesium plus tin( ii) nitrate solution grey deposit on magnesium tin plus cobalt nitrate solution no reaction  (i)  give as far as possible the order of reactivity of these metals.  write the least reactive \ufb01 rst.   . .  [2]  (ii)  what additional experiment needs to be done to put all four metals in order of  reactivity?   . .  [1]  (iii)  write an ionic equation for the reaction between tin atoms and silver( i) ions. indicate  on the equation the change which is oxidation.   . ...   . .  [3]  (b)  sodium is a more reactive metal than magnesium. sodium compounds are more stable  than magnesium compounds.   in an experiment, their hydroxides were heated. if the hydroxide did not decompose write  \u2018no reaction\u2019 otherwise complete the equation.  naoh  \u2192  .  mg(oh)2  \u2192  . [2]",
            "5": "5 0620/33/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  a cell consists of two different metal electrodes in an electrolyte.  three possible cells are shown below. v zinc copper dilute acid1.1  v v tin dilute acid0.5  v v zinc tin dilute acid...  v + \u2013 + \u2013  (i)  why is the more reactive metal the negative electrode?   . ...   . .  [2]  (ii)  how can you deduce that zinc is more reactive than tin?   . .  [1]  (iii)  how could you change the zinc/copper cell to have a voltage greater than 1.1  v?   . .  [1]  (iv)  complete the labelling of the zinc/tin cell. [2] [total: 14]",
            "6": "6 0620/33/o/n/10 \u00a9 ucles 2010for examiner\u2019s use4  the electrolysis of concentrated aqueous sodium chloride, between inert electrodes, is used  to make four important chemicals.  hydrogen  chlorine sodium hydroxide sodium chlorate( i)  (a)  the ions present in the electrolyte are na +, h+, c l \u2013 and oh  \u2013.  (i)  hydrogen ions are discharged at the negative electrode (cathode).   write an equation for this reaction.   . .  [2]  (ii)  the hydrogen ions are from the water. h2o    h+  +  oh  \u2013  suggest an explanation why the concentration of hydroxide ions increases.  . ...   . .  [2]  (iii)  when a dilute solution of sodium chloride is used, chlorine is not formed at the  positive electrode (anode), a different gas is produced. name this gas.   . .  [1]  (iv)  state an example of an inert electrode.   . .  [1]  (b) (i)   state a use of hydrogen.   . .  [1]  (ii)  why is chlorine used to treat the water supply?   . .  [1]",
            "7": "7 0620/33/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  sodium chlorate( i) is made by the reaction between chlorine and sodium hydroxide. it is  used as bleach but over time it decomposes. 2nac l o(aq)  \u2192  2nac l (aq)  +  o2(g)   the rate of decomposition can be studied using the apparatus shown below. sodium chlorate( i) solution   (i)  how could you measure the rate of decomposition of sodium chlorate( i)?   . .  [1]  (ii)  describe how you could show that the rate of decomposition of sodium chlorate( i) is  a photochemical reaction.   . ...   . .  [2] [total: 11]",
            "8": "8 0620/33/o/n/10 \u00a9 ucles 2010for examiner\u2019s use5  carboxylic acids contain the group o ohco r cooh.  (a)  ethanoic acid is a typical carboxylic acid. it forms ethanoates.  (i)  complete the following equations. mg  +  ...ch3cooh  \u2192    +   [2] ethanoic acidsodium hydroxide+ \u2192    +   [1]  (ii)  ethanoic acid reacts with ethanol to form an ester. give the name of the ester and  draw its structural formula. show all of the bonds.  name   ..  structural formula [2]  (b)  maleic acid is an unsaturated acid. 5.8  g of this acid contained 2.4  g of carbon, 0.2  g of  hydrogen and 3.2  g of oxygen.  (i)  how do you know that the acid contained only carbon, hydrogen and oxygen?   . ...   . .  [1]  (ii)  calculate the empirical formula of maleic acid.  number of moles of carbon atoms =   number of moles of hydrogen atoms =  number of moles of oxygen atoms =   the empirical formula is  ..  [3]",
            "9": "9 0620/33/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (iii)  the mass of one mole of maleic acid is 116  g. what is its molecular formula?   . .  [2]  (iv)  maleic acid is dibasic. one mole of acid produces two moles of h+. deduce its  structural formula. [2] [total: 13]",
            "10": "10 0620/33/o/n/10 \u00a9 ucles 2010for examiner\u2019s use6  the kinetic theory explains the properties of matter in terms of the arrangement and  movement of particles.  (a)  nitrogen is a gas at room temperature. nitrogen molecules, n2, which are spread far  apart move in a random manner at high speed.  (i)  draw a diagram showing the arrangement of the valency electrons in a nitrogen  molecule.   use \u00d7 to represent an electron from a nitrogen atom. [2]  (ii)  how does the movement and arrangement of the molecules in a crystal of nitrogen  differ from those in gaseous nitrogen?   . ...   . ...   . .. [3]  (b)  use the ideas of the kinetic theory to explain the following.  (i)  a sealed container contains nitrogen gas. the pressure of a gas is due to the  molecules of the gas hitting the walls of the container.   explain why the pressure inside the container increases when the temperature is  increased.   . ...   . .  [2]",
            "11": "11 0620/33/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (ii)  the following apparatus can be used to measure the rate of diffusion of a gas. constant pressure applied gas syringe gasmetal foilgas escapesthrough smallhole in foil   the following results were obtained. gastemperature / \u00b0crate of diffusion in cm3 / min nitrogen 25 1.00 chlorine 25 0.63nitrogen 50 1.05  explain why nitrogen diffuses faster than chlorine.   . ...   . .  [2]  explain why the nitrogen diffuses faster at the higher temperature.  . .  [1] [total: 10]",
            "12": "12 0620/33/o/n/10 \u00a9 ucles 2010for examiner\u2019s use7  synthetic polymers are widely used in the modern world.  (a)  their use has brought considerable advantages to modern life as well as some  disadvantages.  (i)  suggest two advantages of a plastic bucket compared to a steel bucket.   . ...   . .  [2]  (ii)  name two uses of man-made \ufb01 bres, such as nylon and terylene.   . ...   . .  [2]  (iii)  describe the pollution caused by synthetic polymers.   . ...   . ...   . .  [3]  (b)  one type of polymer is formed by addition polymerisation.  (i)  the structural formula of an addition polymer is given below. nch ch3ch2   give the name and structural formula of the monomer.  name of monomer  ...  [1] structural formula of monomer [1]",
            "13": "13 0620/33/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  draw the structural formula of the addition polymer formed by the polymerisation of  phenylethene. the structural formula of phenylethene is given below. cch hc6h5 h [2]   (c)  nylon is made by condensation polymerisation. it has the structural formula shown  below. c( c h2)8(ch2)6 o oc n hn h  (i)  name the linkage in this polymer.   . .  [1]  (ii)  name the natural macromolecules which have the same linkage.   . .  [1]  (iii)  deduce the formulae of the two monomers which reacted to form the nylon and  water.  monomer  ...  monomer  ... [2] [total: 15]",
            "14": "14 0620/33/o/n/10blank page \u00a9 ucles 2010",
            "15": "15 0620/33/o/n/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/33/o/n/10 \u00a9 ucles 2010 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w10_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test october/november 2010  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 8 printed pages. [turn overib10 11_0620_51/3rp\u00a9 ucles 2010 *5922988318* for examiner\u2019s use total1 2",
            "2": "2 0620/51/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  you are going to investigate what happens when two different solids, a and b, dissolve in  water.   read all instructions below carefully before starting the experiments.   instructions   you are going to carry out two sets of experiments.  (a)  experiment 1    using a measuring cylinder, pour 20  cm3 of distilled water into the polystyrene cup  provided. put the cup into a 250  cm3 beaker for support. measure the temperature of the  water and record it in the table below.    add 2  g of solid a provided to the cup and stir the mixture with a thermometer. measure  and record the temperature of the solution after one minute. pour the solution away and rinse the polystyrene cup.    repeat the experiment using 3  g of the solid a provided. record your results in the table.    repeat the experiment using 4  g of the solid a provided. record your results in the table.    repeat the experiment using 6  g of the solid a provided. record your results in the table. mass of solid a / g initial temperature  / \u00b0c \ufb01 nal temperature  / \u00b0c 2 346 [3]  (b)  experiment 2    repeat experiment 1 using 2  g, 3  g and 4  g of solid b respectively.    record your results in the table below. mass of solid b / g initial temperature  / \u00b0c \ufb01 nal temperature  / \u00b0c 2 34 [2]",
            "3": "3 0620/51/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  plot the results of the experiments on the grid below. draw two best- \ufb01 t straight line  graphs.  clearly label your graphs. 40 30 20 10 0 0123456final temperature/  \u00b0c mass of solid  / g [6]",
            "4": "4 0620/51/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (d) (i)   use your graph  to estimate the temperature of the reaction mixture if 6  g of solid b  was added to 20  cm3 of water.   show clearly on the grid  how you worked out your answer.   . .  [2]  (ii)  from your graph , work out the temperature of the reaction mixture if 5  g of solid a  was added to 20  cm3 of water.   show clearly on the graph  how you worked out your answer.   . .  [2]  (e)  what type of chemical reaction occurs when solid a dissolves in water?   ... ..  [1]  (f)  explain how the temperature changes would differ in the experiments if 40  cm3 of water  was used.   ...    ...    ... ..  [2]  (g)  predict the effect of using lumps of solid b in experiment 2. explain your answer.   ...    ... ..  [2]  (h)  suggest one change you could make to the apparatus  used in the experiments to obtain  more accurate results.   ...    ... ..  [1] [total: 21]",
            "5": "5 0620/51/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  you are provided with a mixture of two solids, c and d. solid c is water-soluble and d is  insoluble. carry out the following tests on c and d, recording all of your observations in the  table.  conclusions must not be written in the table. tests observations add 15  cm3 of distilled water to the mixture in  the boiling tube. stopper and shake the boiling tube for two minutes. filter the contents of the tube, keeping the \ufb01 ltrate and the residue for  the following tests. test on the \ufb01 ltrate (a)  to about 1  cm3 of the solution, add a few  drops of dilute nitric acid and about 1  cm3  of aqueous potassium iodide.. ...  [2] (b)  to about 1  cm3 of the solution add about 1 cm3 of dilute hydrochloric acid. ...  [1] (c)  to about 1  cm3 of the solution add an equal  volume of aqueous sodium hydroxide.   now add a small spatula measure of  aluminium powder and warm the mixture carefully . test any gases given off.. ...  [2]",
            "6": "6 0620/51/o/n/10 \u00a9 ucles 2010for examiner\u2019s usetests observations tests on the residue wash the residue in the \ufb01 lter paper with a little  distilled water. using a spatula, transfer some of the  solid residue from the \ufb01 lter paper into two test-tubes. (d)  heat the solid in the \ufb01 rst test-tube gently  and then strongly. leave the test-tube to cool.. ...  [2] (e)  add about 2  cm3 of dilute hydrochloric acid  to the second test-tube. test the gas given off with limewater.. ...  [2] (f)  after 2 minutes, add an equal volume of  distilled water and shake the test-tube. decant off the liquid and divide into two approximately equal portions.  (i)  to the \ufb01 rst portion add aqueous  sodium hydroxide a little at a time until in excess.  (ii)  to the second portion add aqueous  ammonia a little at a time until in excess.. ...  [2] . ...  [2]",
            "7": "7 0620/51/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (g)   identify the gas given off in test (c).   ... ..  [1]  (h)  identify solid c.   ... ..  [2]  (i)  what conclusions can you draw about solid d?   ...    ...    ... ..  [3] [total: 19]",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/51/o/n/10notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2010"
        },
        "0620_w10_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test october/november 2010  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 8 printed pages. [turn overib10 11_0620_52/fp\u00a9 ucles 2010 *2536379922* for examiner\u2019s use total1 2",
            "2": "2 0620/52/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  you are going to investigate what happens when two different solids, a and b, dissolve in  water.   read all instructions below carefully before starting the experiments.   instructions   you are going to carry out two sets of experiments.  (a)  experiment 1    using a measuring cylinder, pour 20  cm3 of distilled water into the polystyrene cup  provided. put the cup into a 250  cm3 beaker for support. measure the temperature of the  water and record it in the table below.    add 2  g of solid a provided to the cup and stir the mixture with a thermometer. measure  and record the temperature of the solution after one minute. pour the solution away and rinse the polystyrene cup.    repeat the experiment using 3  g of the solid a provided. record your results in the table.    repeat the experiment using 4  g of the solid a provided. record your results in the table.    repeat the experiment using 6  g of the solid a provided. record your results in the table. mass of solid a / g initial temperature  / \u00b0c \ufb01 nal temperature  / \u00b0c 2 346 [3]  (b)  experiment 2    repeat experiment 1 using 2  g, 3  g and 4  g of solid b respectively.    record your results in the table below. mass of solid b / g initial temperature  / \u00b0c \ufb01 nal temperature  / \u00b0c 2 34 [2]",
            "3": "3 0620/52/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  plot the results of the experiments on the grid below. draw two best- \ufb01 t straight line  graphs.  clearly label your graphs. 40 30 20 10 0 0123456final temperature/  \u00b0c mass of solid  / g [6]",
            "4": "4 0620/52/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (d) (i)   use your graph  to estimate the temperature of the reaction mixture if 6  g of solid b  was added to 20  cm3 of water.   show clearly on the grid  how you worked out your answer.   . .  [2]  (ii)  from your graph , work out the temperature of the reaction mixture if 5  g of solid a  was added to 20  cm3 of water.   show clearly on the graph  how you worked out your answer.   . .  [2]  (e)  what type of chemical reaction occurs when solid a dissolves in water?   ... ..  [1]  (f)  explain how the temperature changes would differ in the experiments if 40  cm3 of water  was used.   ...    ...    ... ..  [2]  (g)  predict the effect of using lumps of solid b in experiment 2. explain your answer.   ...    ... ..  [2]  (h)  suggest one change you could make to the apparatus  used in the experiments to obtain  more accurate results.   ...    ... ..  [1] [total: 21]",
            "5": "5 0620/52/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  you are provided with a mixture of two solids, c and d. solid c is water-soluble and d is  insoluble. carry out the following tests on c and d, recording all of your observations in the  table.  conclusions must not be written in the table. tests observations add 15  cm3 of distilled water to the mixture in  the boiling tube. stopper and shake the boiling tube for two minutes. filter the contents of the tube, keeping the \ufb01 ltrate and the residue for  the following tests. test on the \ufb01 ltrate (a)  to about 1  cm3 of the solution, add a few  drops of dilute nitric acid and about 1  cm3  of aqueous potassium iodide.. ...  [2] (b)  to about 1  cm3 of the solution add about 1 cm3 of dilute hydrochloric acid. ...  [1] (c)  to about 1  cm3 of the solution add an equal  volume of aqueous sodium hydroxide.   now add a small spatula measure of  aluminium powder and warm the mixture carefully . test any gases given off.. ...  [2]",
            "6": "6 0620/52/o/n/10 \u00a9 ucles 2010for examiner\u2019s usetests observations tests on the residue wash the residue in the \ufb01 lter paper with a little  distilled water. using a spatula, transfer some of the  solid residue from the \ufb01 lter paper into two test-tubes. (d)  heat the solid in the \ufb01 rst test-tube gently  and then strongly. leave the test-tube to cool.. ...  [2] (e)  add about 2  cm3 of dilute hydrochloric acid  to the second test-tube. test the gas given off with limewater.. ...  [2] (f)  after 2 minutes, add an equal volume of  distilled water and shake the test-tube. decant off the liquid and divide into two approximately equal portions.  (i)  to the \ufb01 rst portion add aqueous  sodium hydroxide a little at a time until in excess.  (ii)  to the second portion add aqueous  ammonia a little at a time until in excess.. ...  [2] . ...  [2]",
            "7": "7 0620/52/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (g)   identify the gas given off in test (c).   ... ..  [1]  (h)  identify solid c.   ... ..  [2]  (i)  what conclusions can you draw about solid d?   ...    ...    ... ..  [3] [total: 19]",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/52/o/n/10notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2010"
        },
        "0620_w10_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test october/november 2010  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 6 printed pages and 2 blank pages. [turn overib10 11_0620_53/3rp\u00a9 ucles 2010 *3216989122* for examiner\u2019s use total1 2",
            "2": "2 0620/53/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  you are going to investigate what happens when dilute hydrochloric acid reacts with two  different alkaline solutions, f and g.   read all instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   fill the burette with the dilute hydrochloric acid provided to the 0.0  cm3 mark.    using a measuring cylinder, pour 25  cm3 of solution f into a conical \ufb02 ask. add 4 to 6  drops of phenolphthalein indicator to the conical \ufb02 ask.    add the hydrochloric acid from the burette 1  cm3 at a time while shaking the \ufb02 ask. when  the colour of the phenolphthalein changes, record in the table the volume of acid added.  (b)  experiment 2   fill the burette with dilute hydrochloric acid to the 0.0  cm3 mark.    empty the conical \ufb02 ask and rinse it with water. using a measuring cylinder, pour 25  cm3  of solution g into the conical \ufb02 ask. add 4 to 6 drops of phenolphthalein to the conical  \ufb02 ask.    add the hydrochloric acid from the burette 1 cm3 at a time while shaking the \ufb02 ask. when  the colour of the phenolphthalein changes, record in the table the volume of acid added. experiment solutionvolume of hydrochloric acid  added  / cm3 1 f 2 g [4]",
            "3": "3 0620/53/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  what colour change was observed when hydrochloric acid was added to the conical  \ufb02 ask?  from ... to ... [2]  (d) (i)   which ion is present in all alkaline solutions?   . .  [1]  (ii)  what type of chemical reaction occurs when hydrochloric acid reacts with alkaline  solutions?   . .  [1]  (e) (i)   in which experiment was the greatest volume of hydrochloric acid used?   . .  [1]  (ii)  compare the volumes of hydrochloric acid used in experiments 1 and 2.   . .  [1]  (iii)  suggest an explanation for the difference in volumes.   . ...   . ...   . .  [2]  (f)  if experiment 2 were repeated using 12.5  cm3 of solution g, what volume of hydrochloric  acid would be used? explain your answer.   ...    ... ..  [2]  (g) (i)   state two sources of error in the experiments.  1  ... ..  2  ...   [2]  (ii)  suggest two improvements to reduce the sources of error in the experiments.  1  ... ..  2  ...   [2] [total: 18]",
            "4": "4 0620/53/o/n/10 \u00a9 ucles 2010for examiner\u2019s use2  you are provided with two different salts, w and x.   carry out the following tests on each salt, recording all of your observations in the table.  conclusions must not be written in the table. tests observations tests on solid w (a)  describe the appearance of solid w. ...  [1] (b)  place half of solid w in a test-tube.  heat the test-tube gently . test any  gas given off with damp ph indicator  paper.. ...  [2] (c)  add the rest of solid w to about 6  cm3  of distilled water in a test-tube.   cork the test-tube and shake the contents until dissolved.   divide the solution into 3 equal portions in test-tubes and carry out the following tests.  (i)  add about 1  cm3 of dilute  hydrochloric acid to the \ufb01 rst  portion of the solution and then add aqueous barium chloride.  (ii)  add about 1  cm3 of dilute nitric  acid to the second portion of the solution and then add silver nitrate solution.  (iii)  to the third portion of the solution add about 1  cm3 of aqueous  sodium hydroxide. heat the mixture gently and test any gases given off with damp ph indicator paper.. ...  [2] ...  [1] . ...  [2]",
            "5": "5 0620/53/o/n/10 \u00a9 ucles 2010for examiner\u2019s usetests observations tests on solid x (d)  repeat experiment (b) using about  half of the solid x. leave the test-tube  and contents to cool. this will be used  in test (f).. ...  [2] (e)  dissolve the rest of solid x in  about 4  cm3 of distilled water in a test-tube. divide the solution into 3 equal portions in test-tubes and carry out the following tests.  (i)  to the \ufb01 rst portion, add excess  aqueous sodium hydroxide.  (ii)  to the second portion, add a few drops of hydrochloric acid, followed by aqueous barium chloride.  (iii)  to the third portion, add aqueous potassium manganate( vii) drop  by drop.. ...  [2] ...  [1]...  [1] (f)  using a teat pipette, add drops of cold  water to the test-tube and contents from test (d).. ...  [2]  (g)  identify the gas given off in test (b).   ... ..  [1]  (h)  what conclusions can you draw about solid w?   ...    ... ..  [2]  (i)  identify solid x.   ...    ...    ... ..  [3] [total: 22]",
            "6": "6 0620/53/o/n/10blank page \u00a9 ucles 2010",
            "7": "7 0620/53/o/n/10blank page \u00a9 ucles 2010",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/53/o/n/10notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2010"
        },
        "0620_w10_qp_61.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical october/november 2010  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib10 11_0620_61/5rp\u00a9 ucles 2010 *8059844668* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/61/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  ethene can be prepared by passing ethanol vapour over hot aluminium oxide. waterethene mineral wool  (a)  complete the boxes to show the chemicals used. [1]  (b)  show on the diagram with two arrows where the heat is applied. [2]  (c)  why must the delivery tube be removed from the water before the heating is stopped?   ...    ...    ... ..  [2] [total: 5]",
            "3": "3 0620/61/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  the following instructions were used to prepare magnesium sulfate crystals, mgso4.7h2o.  step 1   measure 50  cm3 of dilute sulfuric acid into a beaker and warm the solution.  step 2   using a spatula, add some magnesium oxide and stir the mixture. continue  adding the magnesium oxide until excess is present.  step 3   separate the excess magnesium oxide from the solution of magnesium sulfate.  step 4   heat the solution until crystals form. obtain the crystals and dry them.  (a)  why is the sulfuric acid warmed?   ... ..  [1]  (b)  how would you know when excess magnesium oxide is present in step 2 ?   ... ..  [1]  (c)  what method is used in step 3 ?   ... ..  [1]  (d)  why must care be taken when drying the crystals in step 4 ?   ... ..  [1]  (e)  explain how the method would differ if magnesium carbonate was used instead of magnesium oxide.   ...    ... ..  [2] [total: 6]",
            "4": "4 0620/61/o/n/10 \u00a9 ucles 2010for examiner\u2019s use3  a student carried out an experiment to investigate the speed of reaction between sodium  thiosulfate solution and dilute nitric acid.   sulfur is formed during this reaction and the mixture turns cloudy.  experiment 1   using a measuring cylinder, 100  cm3 of sodium thiosulfate solution was poured into a 250  cm3 beaker. the beaker was placed on a cross drawn on a piece of paper. 20  cm3 of dilute  nitric acid was added to the beaker and the timer started. eye 20  cm3 of dilute nitric acid beaker aqueous sodium thiosulfate paper with cross marked on it   the time until the cross could not be seen was taken. the time was recorded in the table.   experiment 1 was repeated using different volumes of sodium thiosulfate as shown in the  table.   all experiments were carried out at 20  \u00b0c. table of results experimentvolume of sodium  thiosulfate solution  / cm3volume of water  / cm3 time for cross to disappear  / s 1 100 0 10 28 0 2 0 1 234 0 6 0 2 442 0 8 0 5 151 0 9 0 9 8  (a)  why was the total volume of solution kept constant?   ...    ... ..  [1]  (b)  in experiment 2, which is the last liquid to be added to the beaker?   ... ..  [1]",
            "5": "5 0620/61/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c) (i)  plot the results on the grid below. draw a smooth line graph. 0 20 40 60 80 100time  / s volume of sodium thiosulfate solution  / cm3100 90807060 50 40 30 2010 0 [4]",
            "6": "6 0620/61/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  use your graph  to work out the time taken for the cross to disappear when 55  cm3  of sodium thiosulfate solution and 45  cm3 of water were used.   indicate on the graph  how you worked out your answer.   . .  [2]  (d)  the experiments were repeated at 40  \u00b0c. suggest how the results would differ. explain  your answer.   ...    ... ..  [2] [total: 10]",
            "7": "7 0620/61/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use4  a student investigated the solubility of salt a in water at various temperatures.  five experiments were carried out.  experiment 1   the student was provided with a boiling tube containing 12  g of salt a.   a burette was \ufb01 lled with distilled water and 10.0  cm3 of water was added to the boiling tube.  the mixture of salt a and water was heated until all of the solid had dissolved.   the boiling tube was removed from the heat and the solution was stirred with a thermometer  and allowed to cool.   the temperature at which crystals \ufb01 rst appeared was measured.   use the thermometer diagram to record the temperature in the table of results. 70 65 60   the boiling tube and contents were kept for the next four experiments.  experiment 2   from the burette, 1.0  cm3 more of water was added into the boiling tube and contents from  experiment 1.   the experiment was repeated exactly as before to \ufb01 nd the temperature at which crystals \ufb01 rst  appeared.   the boiling tube was dipped for short periods of time in a beaker of cold water to speed up  the cooling.   record, in the table of results, the total volume of water in the boiling tube.   use the thermometer diagram to record the temperature at which crystals \ufb01 rst appeared. 70 65 60",
            "8": "8 0620/61/o/n/10 \u00a9 ucles 2010for examiner\u2019s use  experiment 3   from the burette 1.0  cm3 more of water was added into the boiling tube and contents from  experiment 2. the experiment was repeated exactly as before.   record, in the table of results, the total volume of water used.   use the thermometer diagram to record the temperature at which crystals \ufb01 rst appeared. 60 55 50   this procedure was continued for experiments 4 and 5 with two more successive additions  of 1.0  cm3 of water. note all the results in the table. 60 55 5060 55 50 diagram for experiment 4 diagram for experiment 5 table of results experimenttotal volume of water  / cm3temperature at which crystals \ufb01 rst appeared  / \u00b0c 1 10.0 2345 [5]",
            "9": "9 0620/61/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (a)  plot the results on the grid below and draw a straight line graph. 840 10 12 14 total volume of water /  cm3temperature at which crystals first appeared  / \u00b0c [6]  (b)  how did the student know when salt a was completely dissolved in the water?   ... ..  [1]  (c)  from your graph , \ufb01 nd the temperature at which crystals of salt a would \ufb01 rst appear if  the total volume of water in the solution was 9.0  cm3.   show clearly on the grid  how you worked out your answer.   ... ..  [2]",
            "10": "10 0620/61/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (d)  suggest, with a reason, how the results would be different if 6  g of salt a were used  instead of 12  g of salt a.   ...    ... ..  [2]  (e) salt b is more soluble in water than salt a.   sketch on the grid the graph you would expect for salt b. label this graph. [2]  (f)  explain one improvement you could make to the experimental procedure to obtain more  accurate results in this investigation.  improvement  .   explanation  .   [2] [total: 20]",
            "11": "11 0620/61/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  two different solutions, x and y, were analysed. x was copper sulfate solution.   the tests on the solutions, and some of the observations, are in the following table.   complete the observations in the table. tests observations tests on solution x (a) (i)  appearance of solution x.  (ii)  to a little of solution x, aqueous  sodium hydroxide was added.  (iii)  to a little of solution x, aqueous  ammonia was added drop by drop and shaken.   excess aqueous ammonia solution  was then added to the test-tube.  [1]   [2]  [1] ..   [2] tests on solution y (b) (i)  a little of solution y was tested with  universal indicator paper. the ph was recorded.  (ii)  to about 3  cm3 of solution y a few  drops of dilute hydrochloric acid and then aqueous barium chloride wasadded.ph1 white precipitate  (c)  identify solution y.   ... ..  [2] [total: 8]",
            "12": "12 0620/61/o/n/10 \u00a9 ucles 2010for examiner\u2019s use6  a concentrated solution of sodium chloride was electrolysed using the apparatus below. + \u2013 positive  electrode negative  electrode  concentratedaqueous sodium chlorideand universal indicator   one observation noted was that the universal indicator turned purple at the negative  electrode.  (a)  what observation would be made at both  electrodes?   ... ..  [1]  (b)  why did the indicator turn purple at the negative electrode?   ... ..  [1]  (c) (i)  name the product formed at the positive electrode.   . .  [1]  (ii)  suggest the effect of this product on the universal indicator.   . .  [1] [total: 4]",
            "13": "13 0620/61/o/n/10 \u00a9 ucles 2010for examiner\u2019s use7  e numbers identify chemicals which are added to foods.  (a)  e210 is benzoic acid. how could you show that a solution of benzoic acid is a weak  acid?  test     result  .. .  [2]  (b)  e211 is sodium benzoate. name a suitable substance that would react with a solution of  benzoic acid to form sodium benzoate.   ... ..  [1]  (c)  e110 is sunset yellow.   outline a method you could use to show the presence of e110 in a food colouring.   a space has been left if you want to draw a diagram to help you answer the question.   ...    ...    ...    ...    ... ..  [4] [total: 7]",
            "14": "14 0620/61/o/n/10blank page \u00a9 ucles 2010",
            "15": "15 0620/61/o/n/10blank page \u00a9 ucles 2010",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/61/o/n/10blank page \u00a9 ucles 2010"
        },
        "0620_w10_qp_62.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical october/november 2010  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib10 11_0620_62/5rp\u00a9 ucles 2010 *9445620254* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/62/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  the diagram shows the apparatus used by a student to \ufb01 nd the concentration of hydrochloric  acid.   sodium hydroxide solution was added to hydrochloric acid until the solution was neutral. hydrochloric acidsodium hydroxide  (a)  complete the boxes to name the apparatus used. [3]  (b)  how could the student tell when the solution was neutral?   ...    ... ..  [2] [total: 5]",
            "3": "3 0620/62/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  three bottles of liquids have lost their labels.   the liquids are known to be:  aqueous potassium chloride,  ethanol, sodium hydroxide solution.   outline chemical tests you could use to distinguish between the liquids in the three bottles. liquid test result aqueous potassium chloride ethanol sodium hydroxide solution [total: 6]",
            "4": "4 0620/62/o/n/10 \u00a9 ucles 2010for examiner\u2019s use3  dilute sulfuric acid was added to zinc carbonate in a conical \ufb02 ask as shown. cotton wool dilute sulfuric acid zinc carbonate balance129.8   two experiments were carried out.  experiment 1   the \ufb02 ask was placed on a balance and the mass of the \ufb02 ask and contents recorded every  \ufb01 ve minutes. the temperature of the sulfuric acid was 30  \u00b0c.   the results have been plotted on the grid.  experiment 2   experiment 1 was repeated but the temperature of the acid was different. the results are  shown in the table. table of results for experiment 2 time  / minutes 0 5 10 15 20 25 30 mass of \ufb02 ask and contents  / g 129.8 128.4 127.0 125.6 124.0 122.6 121.2",
            "5": "5 0620/62/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (a)  plot the results for experiment 2 on the grid and draw a straight line graph. 130 128126124122120 0 5 10 15 20 25 30 time  / minutesmass of flask and contents  / g [3]  (b)  why does the mass of the \ufb02 ask and contents decrease?   ... ..  [1]  (c)  suggest the purpose of the cotton wool.   ... ..  [1]  (d) (i)  in which experiment was the loss of mass of the \ufb02 ask and contents the fastest?   . .  [1]  (ii)  compare the temperature of the sulfuric acid in experiment 2 with experiment 1.   . .  [1]  (e)  use the graph for experiment 1 to \ufb01 nd the time taken for the mass of the \ufb02 ask and contents  to decrease to 120  g. indicate clearly on the grid  how you obtained your answer. [2]  (f)  on the grid, sketch the graph you would expect if experiment 1 was repeated using more  concentrated sulfuric acid. [1] [total: 10]",
            "6": "6 0620/62/o/n/10 \u00a9 ucles 2010for examiner\u2019s use4  a student investigated the temperature changes when two different solids, a and b, dissolved   in water.  two sets of experiments were carried out. experiment 1   using a measuring cylinder, 20  cm3 of distilled water was poured into a polystyrene cup. the  temperature of the water was measured. 2  g of solid a was added to the cup and the mixture  was stirred with a thermometer. the temperature of the solution was measured after one minute. 25 20 1525 20 15 initial temperature final temperature   the experiment was repeated using 3  g of solid a. 25 20 1525 20 15 initial temperature final temperature   the experiment was repeated using 4  g of solid a. 25 20 1525 20 15 initial temperature final temperature",
            "7": "7 0620/62/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use  the experiment was repeated using 6  g of solid a.   25 20 1525 20 15 initial temperature final temperature  (a)  use the thermometer diagrams for experiment 1 to record the initial and \ufb01 nal temperatures  in table 4.1. table 4.1 mass of solid a / g initial temperature  / \u00b0c \ufb01 nal temperature  / \u00b0c 2 346 [3]",
            "8": "8 0620/62/o/n/10 \u00a9 ucles 2010for examiner\u2019s use  experiment 2   experiment 1 was repeated using 2  g, 3  g and 4  g of solid b respectively.  2  g of b 30 25 2030 25 20 initial temperature final temperature  3  g of b 30 25 2030 25 20 initial temperature final temperature  4  g of b 30 25 2030 25 20 initial temperature final temperature  (b)   use the thermometer diagrams for experiment 2 to record the initial and \ufb01 nal temperatures  in table 4.2. table 4.2 mass of solid b / g initial temperature  / \u00b0c \ufb01 nal temperature  / \u00b0c 2 34 [2]",
            "9": "9 0620/62/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (c)  plot the results of the experiments on the grid below. draw two best- \ufb01 t straight line  graphs. clearly label your graphs. 02 14 6 35 mass of solid added  / gfinal temperature of solution  / \u00b0c40 30 20 10 0 [6]  (d) (i)   use your graph  to estimate the temperature of the reaction mixture if 6  g of solid b  was added to 20  cm3 of water.  show clearly on the grid  how you worked out your answer.   . .  [2]",
            "10": "10 0620/62/o/n/10 \u00a9 ucles 2010for examiner\u2019s use (ii)  from your graph  work out the temperature of the reaction mixture if 5  g of solid a  was added to 20  cm3 of water.   show clearly on the graph  how you worked out your answer.   . .  [2]  (e)  what type of chemical reaction occurred when solid a dissolved in water?   ... ..  [1]  (f)  explain how the temperature changes would differ in the experiments if 40  cm3 of water  was used.   ...    ...    ... ..  [2]  (g)  predict the effect of using lumps of solid b in experiment 2. explain your answer.   ...    ... ..  [2] [total: 20]",
            "11": "11 0620/62/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use5  a mixture of two solids, c and d, was analysed. solid c was lead nitrate, which is water-soluble. solid d was insoluble.   the tests on c and d, and some of the observations, are in the following table.  complete the observations in the table. tests observations water was added to the mixture in a boiling  tube and shaken. the contents of the tube were \ufb01 ltered. tests on \ufb01 ltrate (a)  to about 1  cm3 of the solution, a few drops  of dilute nitric acid and about 1  cm3 of  aqueous potassium iodide was added. (b)  to about 1  cm3 of the solution, sodium  hydroxide solution and aluminium powder were added. the mixture was heated. any gases given off were tested with damp ph indicator paper.  [2]  ..  ..  [3] tests on residue (c)  dilute hydrochloric acid was added to the  residue. the gas given off was tested with limewater.   the solution was divided into two equal  portions.  (i)  to the \ufb01 rst portion, aqueous sodium  hydroxide was added a little at a time until in excess.  (ii)  to the second portion, aqueous  ammonia solution was added a little at a time until in excess.rapid effervescence, limewater turns milky white precipitate, soluble in excess aqueous sodium hydroxide white precipitate, soluble in excess aqueous ammonia solution  (d)  identify the gas given off in test (c).   ... ..  [1]  (e)  identify solid d.   ... ..  [2] [total: 8]",
            "12": "12 0620/62/o/n/10 \u00a9 ucles 2010for examiner\u2019s use6  the apparatus below was used to deposit a thin layer of chromium on a steel knife.   the knife was cleaned carefully and all grease removed before the process started. metal a steel knife solution of salt b  (a)  what is the name of the process when metal objects are coated with other metals?   ... ..  [1]  (b) (i)  suggest the identity of metal a.   . .  [1]  (ii)  suggest the name of salt b.   . .  [1]  (c)  give two reasons why steel knives are coated with chromium.  1.  ...   2.  ... ..  [2] [total: 5]",
            "13": "13 0620/62/o/n/10 \u00a9 ucles 2010for examiner\u2019s use7  iron rusts when in contact with air and water.   you are provided with iron nails and three different samples of water:  tap water,  sea water, distilled water.   plan an investigation to \ufb01 nd out which sample of water causes iron to rust the fastest.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...[6] [total: 6]",
            "14": "14 0620/62/o/n/10blank page \u00a9 ucles 2010",
            "15": "15 0620/62/o/n/10blank page \u00a9 ucles 2010",
            "16": "0620/62/o/n/10permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.16 blank page \u00a9 ucles 2010"
        },
        "0620_w10_qp_63.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical october/november 2010  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib10 11_0620_63/3rp\u00a9 ucles 2010 *2908924238* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/63/o/n/10 \u00a9 ucles 2010for examiner\u2019s use1  a student separated a mixture of two alkanes, decane (b.p. 174  \u00b0c) and octane (b.p. 126  \u00b0c)  using the apparatus shown below. heatacb  (a) (i)  name this method of separation.   . .  [1]  (ii)  name the pieces of apparatus labelled  a  . ...  b  ..  [ 2]  (b)  why would an electric heater be used rather than a \ufb02 ame for heating this mixture?   ... ..  [1]  (c)  which of the two alkanes would be collected \ufb01 rst at c?   ... ..  [1]  (d)  how would the student know when the second alkane began to be collected?   ... ..  [1] [total: 6]",
            "3": "3 0620/63/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use2  the notes below show the steps taken by a student to prepare crystals of hydrated nickel  nitrate, ni(no3)2.6h2o.  step 1   place 25  cm3 of dilute nitric acid in a beaker.  step 2   add nickel carbonate powder to the beaker until it is in excess.  step 3   separate the solution of nickel nitrate from the mixture.  step 4   heat the solution to obtain crystals of hydrated nickel nitrate.  (a) (i)  name the piece of apparatus used to measure the nitric acid in step 1 .   . .  [1]  (ii)  why is it not necessary to heat the dilute nitric acid before adding the nickel  carbonate?   . .  [1]  (b)  how would the student know when excess nickel carbonate was present in step 2 ?   ... ..  [1]  (c)  draw a diagram to show the separation method used in step 3 . [2]  (d)  how could the student make sure a good sample of crystals was obtained when carrying  out step 4 ? explain your answer.   ...    ...    ... ..  [2] [total: 7]",
            "4": "4 0620/63/o/n/10 \u00a9 ucles 2010for examiner\u2019s use3  peter investigated the temperature change when 0.5  g of zinc powder was added to 50  cm3  of copper sulfate solution in a beaker.   the experiment was repeated three times using different masses of zinc powder. the initial  temperature of the copper sulfate solution was the same in each experiment. copper sulfate solutionthermometer zinc powder   the thermometer diagrams show the highest temperature reached. 35 30 25 0.5  g zinc35 30 25 1.0  g zinc35 30 25 1.5  g zinc35 30 25 2.0  g zinc  (a)  use the thermometer diagrams to complete the table of results. table of results mass of zinc  / ginitial temperature  / \u00b0chighest temperature  / \u00b0ctemperature rise  / \u00b0c 0.5 21 1.0 211.5 212.0 21 [2]",
            "5": "5 0620/63/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (b)  plot the results on the grid below and connect the points with straight lines. 12 10 86420 0 0.5 1.0 1.5 2.0 2.5temperature rise  / \u00b0c mass of zinc  / g [3]  (c) (i)   use your graph  to \ufb01 nd the mass of zinc required to produce a temperature rise of 6.0  \u00b0c. show clearly on the grid  how you obtained your answer.   . .  [2]  (ii)  suggest why the temperature rise was the same in the last two experiments.   . .  [1]  (d)  sketch on the grid the graph you would expect if the experiments were repeated using  the same masses of magnesium powder. [2] [total: 10]",
            "6": "6 0620/63/o/n/10 \u00a9 ucles 2010for examiner\u2019s use4 (a)  a student investigated the reaction between dilute hydrochloric acid and two different  alkaline solutions, f and g.   two experiments were carried out.  experiment 1   a burette was \ufb01 lled up to the 0.0  cm3 mark with dilute hydrochloric acid.   using a measuring cylinder, 25  cm3 of solution f was placed into a conical \ufb02 ask with a  few drops of phenolphthalein indicator.   the hydrochloric acid was added to the \ufb02 ask until the colour of the phenolphthalein  changed. use the burette diagram to record the \ufb01 nal volume in the table of results. 12 1314  experiment 2   experiment 1 was repeated using solution g.   use the burette diagrams to record the volumes and complete the table of results. 7 89 initial333435 final table of results burette readings / cm3 experiment 1 experiment 2 \ufb01 nal reading initial reading difference [4]",
            "7": "7 0620/63/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (b)  which ion is present in all alkaline solutions?   ... ..  [1]  (c) (i)  in which experiment was the greatest volume of hydrochloric acid used?   . .  [1]  (ii)  compare the volumes of hydrochloric acid used in experiments 1 and 2.   . .  [1]  (iii)  suggest explanations for the difference in volumes.   . ...   . ...   . .  [2]  (d)  predict the volume of hydrochloric acid which would be needed to react completely with  12.5  cm3 of solution g. explain your answer.   ...    ... ..  [3]  (e) (i)  state two sources of error in the experimental procedure.  1.  .. ..  2.  ..   [2]  (ii)  suggest two improvements to reduce the sources of error in the experimental  procedure.  1.  .. ..  2.  ..   [2] [total: 16]",
            "8": "8 0620/63/o/n/10 \u00a9 ucles 2010for examiner\u2019s use5  two salts, w and x, were analysed. x was iron( ii) chloride.  the tests on each salt, and some of their observations, are in the following table. complete the observations in the table. tests observations tests on salt w (a)  a little of w was heated in a test-tube. any  gas given off was tested with damp ph indicator paper.a white solid formed at the top of the test-tube pungent gas evolved, ph 8-10 (b)  w was dissolved in distilled water in a test-tube.   the solution was divided into three portions  in test-tubes and the following tests carried out.  (i)  to the \ufb01 rst portion, dilute hydrochloric  acid was added and then aqueous barium chloride.  (ii)  to the second portion, dilute nitric  acid was added and then aqueous silver nitrate.  (iii)  to the third portion, aqueous sodium  hydroxide was added. the mixture was heated and any gases given off were tested with damp ph indicator paper.white precipitate no visible reaction pungent gas evolved, ph 8-10 tests on salt x (c)  appearance of salt x. (d)  salt x was dissolved in distilled water in  a test-tube. the solution was divided into two portions.  (i)  to the \ufb01 rst portion, excess aqueous  sodium hydroxide was added.  (ii)  to the second portion, a few drops  of nitric acid was added followed by aqueous silver nitrate..  [1] ... .  [2] ... .  [2]",
            "9": "9 0620/63/o/n/10 \u00a9 ucles 2010 [turn overfor examiner\u2019s use (e)  identify the gas given off in tests (a) and (b)(iii) .   ... ..  [1]  (f)  what conclusions can you draw about salt w?   ...    ...    ... ..  [3] [total: 9]",
            "10": "10 0620/63/o/n/10 \u00a9 ucles 2010for examiner\u2019s use6  a student passed hydrogen over hot copper oxide using the apparatus below. copper was  formed. excess hydrogenburning in air hydrogenpowdered copper oxide ice colourless liquidheat  (a)  explain why powdered copper oxide was used and not lumps of copper oxide.   ...    ... ..  [2]  (b)  the copper oxide changed colour from black to  [1]  (c)  what caused the colourless liquid to form in the u-tube?   ... ..  [1]  (d)  give a chemical test that could be carried out on the colourless liquid to show the  presence of water.  test   ...   result   . .  [2] [total: 6]",
            "11": "11 0620/63/o/n/10 \u00a9 ucles 2010for examiner\u2019s use7  the label shows the substances present in a bottle of orange fruit drink. orange fruit drink contains: orange juice, malic acid, citric acid and natural colours (carotenes) no artificial colours (e numbers)  (a)  a piece of ph indicator paper was dipped in the drink.  (i)  predict the ph value obtained.   . .  [1]  (ii)  why does the ph indicator paper give a more reliable result than adding universal  indicator solution to the drink?   . ...   . .  [1]  (b)  describe an experiment you could carry out to show that only natural colours were  present in the drink.  a space has been left if you want to draw a diagram to help you answer the question.   ...    ...    ...    ...    ... ..  [4] [total: 6]",
            "12": "0620/63/o/n/10permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.12 blank page \u00a9 ucles 2010"
        }
    },
    "2011": {
        "0620_s11_qp_11.pdf": {
            "1": "    this document consists of 16 printed pages.  ib11 06_0620_11/2rp  \u00a9 ucles 2011  [turn over       *9373386046* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  may/june 2011       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2011 0620/11/m/j/11  1 the diagrams show the arrangement of particles in three different physical states of substance x.    state 1 state 2 state 3    which statement about the physical states of substance x is correct?  a particles in state 1 vibrate about fixed positions.  b state 1 changes to state 2 by diffusion.  c state 2 changes directly to state 3 by condensation.  d the substance in stage 3 has a fixed volume.     2 an aqueous solution is coloured.    which method of separation would show that the solution contains ions of different colours?  a chromatography  b crystallisation  c distillation  d filtration      3 the table gives the solubility of four substances in ethanol and in water.    a mixture containing all four substances is added to ethanol, stirred and filtered.    the solid residue is added to water, stirred and filtered.    the filtrate is evaporated to dryness, leaving a white solid.    which is the white solid?    solubility in    ethanol water  a insoluble insoluble  b insoluble soluble  c soluble insoluble  d soluble soluble    ",
            "3": "3  \u00a9 ucles 2011 0620/11/m/j/11 [turn over  4 which two elements react together to form an ionic compound?    element electronic structure  w 2,4  x 2,8  y 2,8,1  z 2,8,7    a w and x b x and y c y and z d z and w     5 the diagram shows part of the periodic table.    a cb d     which element is correctly matched with its electronic structure?     electronic structure  a 2,8,1  b 2,4  c 2,8,2  d 2,8      6 in the diagrams, circles of different sizes represent atoms of different elements.    which diagram represents hydrogen chloride gas?    b ac d     ",
            "4": "4  \u00a9 ucles 2011 0620/11/m/j/11  7 the nucleon number and proton number of the lithium atom are shown by the symbol li7 3.    what is the correct symbol for the lithium ion in lithium chloride?  a 6 2li\u2212 b 6 3li+ c 73li+ d 73li\u2212      8 what is the relative molecular mass ( mr) of hno 3?  a 5 b 31 c 32 d 63     9 electricity from a power station passes through overhead cables to a substation and then to a  school where it is used to electrolyse concentrated hydrochloric acid using inert electrodes.    which substances are used for the overhead cables and for the electrodes?     overhead cables electrodes  a aluminium copper  b aluminium platinum  c copper platinum  d platinum aluminium    10 which statement about the electrolysis of molten lead( ii) bromide is correct?  a a colourless gas is seen at the cathode.  b a grey metal is seen at the anode.  c a red  / brown gas is seen at the anode.  d a red  / brown metal is seen at the cathode.    ",
            "5": "5  \u00a9 ucles 2011 0620/11/m/j/11 [turn over  11 electricity is passed through concentrated aqueous sodium chloride, as shown.    +\u2013positive electrodenegative electrode concentrated aqueous sodiumchloridecarbon rods     what is the test for the gas formed at the positive electrode?  a bleaches damp litmus paper  b \u2018pops\u2019 with a lighted splint  c relights a glowing splint  d turns damp red litmus paper blue      12 three processes are listed.    burning methane in air  radioactive decay of 235u  reacting hydrogen with oxygen.    which statements about these processes are correct?    1 hydrogen and methane are being used as fuels. 2 all the processes involve oxidation.  3 all the processes are used to produce energy.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     ",
            "6": "6  \u00a9 ucles 2011 0620/11/m/j/11  13 butane, ethanol and hydrogen are fuels.    which substances produce both carbon dioxide and water when used as a fuel?     butane ethanol hydrogen  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0017     14 the equation for the effect of heat on hydrated sodium carbonate is as shown.    na 2co 3.10h 2o(s)  na 2co 3(s) + 10h 2o(g)    statements made by four students about the reaction are given.    p anhydrous sodium carbonate is formed.  q steam is formed.  r there is a colour change from blue to white.  s the reaction is reversible.    which students\u2019 statements are correct?  a p, q and r only  b p, q and s only  c q, r and s only  d p, q, r and s     ",
            "7": "7  \u00a9 ucles 2011 0620/11/m/j/11 [turn over  15 the apparatus shown can be used to measure the rate of some chemical reactions.    gas syringe     for which two reactions would the apparatus be suitable?    reaction 1 agno 3(aq) + hc l (aq) \u2192 agc l (s) + hno 3(aq)  reaction 2 2h 2o2(aq) \u2192 2h 2o(l) + o 2(g)  reaction 3 mgo(s) + 2hc l (aq) \u2192 mgc l 2(aq) + h 2o(l)  reaction 4 znco 3(s) + 2hc l (aq) \u2192 znc l 2(aq) + co 2(g) + h 2o(l)    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      16 a student investigates the rate of reaction between magnesium and excess sulfuric acid.     the volume of hydrogen given off in the reaction is measured over time.    the graph shows the results of two experiments, r and s.    r svolume of hydrogen given off time    which change in conditions would cause the difference between r and s?  a a catalyst is added in s.  b the acid is more concentrated in r than in s.  c the magnesium is less finely powdered in r than in s.  d the temperature in r is lower than in s.     ",
            "8": "8  \u00a9 ucles 2011 0620/11/m/j/11  17 carbon dioxide is an acidic oxide that reacts with aqueous calcium hydroxide.    which type of reaction takes place?  a decomposition  b fermentation  c neutralisation  d oxidation     18 which is not a typical property of an acid?  a they react with alkalis producing water.  b they react with all metals producing hydrogen.  c they react with carbonates producing carbon dioxide.  d they turn litmus paper red.    19 a solution contains barium ions and silver ions.    what could the anion be?  a chloride only  b nitrate only  c sulfate only  d chloride or nitrate or sulfate      20 a mixture containing two anions was tested and the results are shown below.    test result  dilute nitric acid added   effervescence of a gas which turned limewater milky  dilute nitric acid added, followed by aqueous silver nitrate yellow precipitate formed     which anions were present?  a carbonate and chloride  b carbonate and iodide  c sulfate and chloride  d sulfate and iodide     ",
            "9": "9  \u00a9 ucles 2011 0620/11/m/j/11 [turn over  21 x is a monatomic gas.    gas x     which statement about x is correct?  a x burns in air.  b x is coloured.  c x is unreactive.  d x will displace iodine from potassium iodide.      22 the diagram shows a section of the periodic table.    w vx z yi ii iii iv v vi vii 0     which elements will conduct electricity at room temperature?  a v, w and x b v, y and w c w, x and z d y and z      23 the equation shows the reaction bet ween a halogen and aqueous bromide ions.    x2 + 2br\u2013(aq) \u2192 2x\u2013(aq) + br 2  \u20261\u2026 \u20262\u2026 \u20263\u2026    which words correctly complete gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     ",
            "10": "10  \u00a9 ucles 2011 0620/11/m/j/11  24 which statement is correct for the element of proton number 19?  a it is a gas that dissolves in water.  b it is a hard metal that is not very reactive with water.  c it is a non-metal that burns quickly in air.  d it is a soft metal that is highly reactive with water.      25 brass is an alloy of copper and zinc.    which statement is correct?  a brass can be represented by a chemical formula.  b brass is formed by a chemical reaction between copper and zinc.  c the alloy will dissolve completely in dilute hydrochloric acid.  d the zinc in the alloy will dissolve in dilute hydrochloric acid.     26 which substance is a metal?     electrical conductivity  (solid) electrical conductivity  (molten)  a high high  b high low  c low high  d low low    27 the table shows the results of adding three metals, p, q and r, to dilute hydrochloric acid and to  water.    metal dilute hydrochloric acid water  p hydrogen produced hydrogen produced  q no reaction no reaction  r hydrogen produced no reaction    what is the order of reactivity of the metals?     most reactive  least reactive  a p r q  b p q r  c r q p  d r p q ",
            "11": "11  \u00a9 ucles 2011 0620/11/m/j/11 [turn over  28 the properties of a metal are important in deciding its use.    which row lists a property that is not correct for the use given?     use of the metal metal property needed  a aluminium in aircraft wings low density  b aluminium in food containers resists corrosion  c mild steel in car bodies high density  d stainless steel in cutlery does not rust     29 which row describes the conditions used to make steel from the iron produced by a blast  furnace?     calcium oxide  (lime) oxygen heat  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017    30 water from a reservoir flows to the water works where purification processes 1 takes place  followed by process 2.    what are purification processes 1 and 2?     purification  process 1 purification  process 2  a chlorination filtration  b filtration chlorination  c fractional distillation filtration  d filtration fractional distillation    ",
            "12": "12  \u00a9 ucles 2011 0620/11/m/j/11  31 the diagram shows the composition by volume of air.    x    what is x?  a argon  b carbon dioxide  c nitrogen  d oxygen     32 the table gives the composition of the atmosphere of four newly discovered planets.    planet composition of atmosphere  w argon, carbon dioxide and oxygen  x argon, nitrogen and oxygen  y argon, carbon dioxide and methane  z methane, nitrogen and oxygen    on which planets is the greenhouse effect likely to occur?  a w only  b w, x and z  c w and y only  d w, y and z     ",
            "13": "13  \u00a9 ucles 2011 0620/11/m/j/11 [turn over  33 statement 1: alloying iron with other materials to form stainless steel prevents iron from rusting    by excluding oxygen.    statement 2: painting, oiling and electroplating are all methods of preventing iron from rusting.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.      34 which two substances, when reacted together, would form a salt that contains two of the  essential elements provided by fertilisers?  a potassium hydroxide and nitric acid  b potassium hydroxide and sulfuric acid  c sodium hydroxide and nitric acid  d sodium hydroxide and sulfuric acid     35 greenhouse gases may contribute to climate change.     two of these gases are emitted into the atmosphere as a result of processes within animals.    gas \u2026\u20261\u2026\u2026 is produced by process \u2026\u20263\u2026\u2026 .  gas \u2026\u20262\u2026\u2026 is produced by process \u2026\u20264\u2026\u2026 .    which words correctly complete gaps 1, 2, 3 and 4?     1 2 3 4  a co c 2h6 digestion respiration  b co c 2h6 respiration digestion  c co 2 ch 4 digestion respiration  d co 2 ch 4 respiration digestion     ",
            "14": "14  \u00a9 ucles 2011 0620/11/m/j/11  36 compounds containing five carbon atoms in a molecule may have names beginning with \u2018pent\u2026\u2019.    what is the name of the compound shown?    key = carbon = oxygen= hydrogen     a pentane  b pentanoic acid  c pentanol  d pentene      37 which industrial process is shown in the diagram?    crude oil vapour bitumenwaste gases petrol paraffin diesellubricating oils     a cracking  b fermentation  c fractional distillation  d polymerisation     ",
            "15": "15  \u00a9 ucles 2011 0620/11/m/j/11  38 the diagram shows the structures of three compounds.    o c hho h c hh c hh hho c chh c h     why do these three compounds belong to the same homologous series?  a they all contain carbon, hydrogen and oxygen.  b they all contain the same functional group.  c they are all carbon based molecules.  d they are all flammable liquids.     39 what is the main constituent of natural gas?  a carbon dioxide  b ethane  c hydrogen  d methane    40 what is not essential for the formation of ethanol by fermentation?  a light  b sugar  c yeast  d water    ",
            "16": "16    permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2011 0620/11/m/j/11   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s11_qp_12.pdf": {
            "1": "    this document consists of 16 printed pages.  ib11 06_0620_12/fp  \u00a9 ucles 2011  [turn over       *5571641406*        university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  may/june 2011       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser  soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.    there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2011 0620/12/m/j/11  1 the diagrams show the arrangement of particles in three different physical states of substance x.    state 1 state 2 state 3    which statement about the physical states of substance x is correct?  a particles in state 1 vibrate about fixed positions.  b state 1 changes to state 2 by diffusion.  c state 2 changes directly to state 3 by condensation.  d the substance in stage 3 has a fixed volume.     2 in the diagrams, circles of different sizes represent atoms of different elements.    which diagram represents hydrogen chloride gas?    b ac d       3 the diagram shows part of the periodic table.    a cb d     which element is correctly matched with its electronic structure?     electronic structure  a 2,8,1  b 2,4  c 2,8,2  d 2,8   ",
            "3": "3  \u00a9 ucles 2011 0620/12/m/j/11 [turn over  4 an aqueous solution is coloured.    which method of separation would show that the solution contains ions of different colours?  a chromatography  b crystallisation  c distillation  d filtration     5 the table gives the solubility of four substances in ethanol and in water.    a mixture containing all four substances is added to ethanol, stirred and filtered.    the solid residue is added to water, stirred and filtered.    the filtrate is evaporated to dryness, leaving a white solid.    which is the white solid?    solubility in    ethanol water  a insoluble insoluble  b insoluble soluble  c soluble insoluble  d soluble soluble    6 which two elements react together to form an ionic compound?    element electronic structure  w 2,4  x 2,8  y 2,8,1  z 2,8,7    a w and x b x and y c y and z d z and w    ",
            "4": "4  \u00a9 ucles 2011 0620/12/m/j/11  7 electricity is passed through concentrated aqueous sodium chloride, as shown.    +\u2013positive electrodenegative electrode concentrated aqueous sodiumchloridecarbon rods     what is the test for the gas formed at the positive electrode?  a bleaches damp litmus paper  b \u2018pops\u2019 with a lighted splint  c relights a glowing splint  d turns damp red litmus paper blue      8 electricity from a power station passes through overhead cables to a substation and then to a  school where it is used to electrolyse concentrated hydrochloric acid using inert electrodes.    which substances are used for the overhead cables and for the electrodes?     overhead cables electrodes  a aluminium copper  b aluminium platinum  c copper platinum  d platinum aluminium      9 the nucleon number and proton number of the lithium atom are shown by the symbol li7 3.    what is the correct symbol for the lithium ion in lithium chloride?  a 6 2li\u2212 b 6 3li+ c 73li+ d 73li\u2212     ",
            "5": "5  \u00a9 ucles 2011 0620/12/m/j/11 [turn over  10 three processes are listed.    burning methane in air  radioactive decay of 235u  reacting hydrogen with oxygen.    which statements about these processes are correct?    1 hydrogen and methane are being used as fuels. 2 all the processes involve oxidation.  3 all the processes are used to produce energy.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3      11 which statement about the electrolysis of molten lead( ii) bromide is correct?  a a colourless gas is seen at the cathode.  b a grey metal is seen at the anode.  c a red  / brown gas is seen at the anode.  d a red  / brown metal is seen at the cathode.      12 what is the relative molecular mass ( mr) of hno 3?  a 5 b 31 c 32 d 63      13 the equation for the effect of heat on hydrated sodium carbonate is as shown.    na2co 3.10h 2o(s)  na 2co 3(s) + 10h 2o(g)    statements made by four students about the reaction are given.    p anhydrous sodium carbonate is formed.  q steam is formed.  r there is a colour change from blue to white.  s the reaction is reversible.    which students\u2019 statements are correct?  a p, q and r only  b p, q and s only  c q, r and s only  d p, q, r and s    ",
            "6": "6  \u00a9 ucles 2011 0620/12/m/j/11  14 the apparatus shown can be used to measure the rate of some chemical reactions.    gas syringe     for which two reactions would the apparatus be suitable?    reaction 1 agno 3(aq) + hc l (aq) \u2192 agc l (s) + hno 3(aq)  reaction 2 2h 2o2(aq) \u2192 2h 2o(l) + o 2(g)  reaction 3 mgo(s) + 2hc l (aq) \u2192 mgc l 2(aq) + h 2o(l)  reaction 4 znco 3(s) + 2hc l (aq) \u2192 znc l 2(aq) + co 2(g) + h 2o(l)    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      15 a student investigates the rate of reaction between magnesium and excess sulfuric acid.     the volume of hydrogen given off in the reaction is measured over time.    the graph shows the results of two experiments, r and s.    r svolume of hydrogen given off time    which change in conditions would cause the difference between r and s?  a a catalyst is added in s.  b the acid is more concentrated in r than in s.  c the magnesium is less finely powdered in r than in s.  d the temperature in r is lower than in s.     ",
            "7": "7  \u00a9 ucles 2011 0620/12/m/j/11 [turn over  16 butane, ethanol and hydrogen are fuels.    which substances produce both carbon dioxide and water when used as a fuel?     butane ethanol hydrogen  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0017     17 x is a monatomic gas.    gas x     which statement about x is correct?  a x burns in air.  b x is coloured.  c x is unreactive.  d x will displace iodine from potassium iodide.      18 the equation shows the reaction between a halogen and aqueous bromide ions.    x2 + 2br\u2013(aq) \u2192 2x\u2013(aq) + br 2  \u20261\u2026 \u20262\u2026 \u20263\u2026    which words correctly complete gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     ",
            "8": "8  \u00a9 ucles 2011 0620/12/m/j/11  19 carbon dioxide is an acidic oxide that reacts with aqueous calcium hydroxide.    which type of reaction takes place?  a decomposition  b fermentation  c neutralisation  d oxidation     20 a solution contains barium ions and silver ions.    what could the anion be?  a chloride only  b nitrate only  c sulfate only  d chloride or nitrate or sulfate      21 a mixture containing two anions was tested and the results are shown below.    test result  dilute nitric acid added   effervescence of a gas which turned limewater milky  dilute nitric acid added, followed  by aqueous silver nitrate yellow precipitate formed     which anions were present?  a carbonate and chloride  b carbonate and iodide  c sulfate and chloride  d sulfate and iodide     22 which is not a typical property of an acid?  a they react with alkalis producing water.  b they react with all metals producing hydrogen.  c they react with carbonates producing carbon dioxide.  d they turn litmus paper red.    ",
            "9": "9  \u00a9 ucles 2011 0620/12/m/j/11 [turn over  23 the diagram shows a section of the periodic table.    w vx z yi ii iii iv v vi vii 0     which elements will conduct electricity at room temperature?  a v, w and x b v, y and w c w, x and z d y and z     24 water from a reservoir flows to the water works where purification processes 1 takes place  followed by process 2.    what are purification processes 1 and 2?     purification  process 1 purification  process 2  a chlorination filtration  b filtration chlorination  c fractional distillation filtration  d filtration fractional distillation      25 the properties of a metal are important in deciding its use.    which row lists a property that is not correct for the use given?     use of the metal metal property needed  a aluminium in aircraft wings low density  b aluminium in food containers resists corrosion  c mild steel in car bodies high density  d stainless steel in cutlery does not rust    ",
            "10": "10  \u00a9 ucles 2011 0620/12/m/j/11  26 brass is an alloy of copper and zinc.    which statement is correct?  a brass can be represented by a chemical formula.  b brass is formed by a chemical reaction between copper and zinc.  c the alloy will dissolve completely in dilute hydrochloric acid.  d the zinc in the alloy will dissolve in dilute hydrochloric acid.     27 which statement is correct for the element of proton number 19?  a it is a gas that dissolves in water.  b it is a hard metal that is not very reactive with water.  c it is a non-metal that burns quickly in air.  d it is a soft metal that is highly reactive with water.    28 which row describes the conditions used to make steel from the iron produced by a blast  furnace?     calcium oxide  (lime) oxygen heat  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017    ",
            "11": "11  \u00a9 ucles 2011 0620/12/m/j/11 [turn over  29 the table shows the results of adding three metals, p, q and r, to dilute hydrochloric acid and to  water.    metal dilute hydrochloric acid water  p hydrogen produced hydrogen produced  q no reaction no reaction  r hydrogen produced no reaction    what is the order of reactivity of the metals?     most reactive  least reactive  a p r q  b p q r  c r q p  d r p q      30 which substance is a metal?     electrical conductivity  (solid) electrical conductivity  (molten)  a high high  b high low  c low high  d low low      31 greenhouse gases may contribute to climate change.     two of these gases are emitted into the atmosphere as a result of processes within animals.    gas \u2026\u20261\u2026\u2026 is produced by process \u2026\u20263\u2026\u2026 .  gas \u2026\u20262\u2026\u2026 is produced by process \u2026\u20264\u2026\u2026 .    which words correctly complete gaps 1, 2, 3 and 4?     1 2 3 4  a co c 2h6 digestion respiration  b co c 2h6 respiration digestion  c co 2 ch 4 digestion respiration  d co 2 ch 4 respiration digestion     ",
            "12": "12  \u00a9 ucles 2011 0620/12/m/j/11  32 the diagram shows the composition by volume of air.    x    what is x?  a argon  b carbon dioxide  c nitrogen  d oxygen     33 the table gives the composition of the atmosphere of four newly discovered planets.    planet composition of atmosphere  w argon, carbon dioxide and oxygen  x argon, nitrogen and oxygen  y argon, carbon dioxide and methane  z methane, nitrogen and oxygen    on which planets is the greenhouse effect likely to occur?  a w only  b w, x and z  c w and y only  d w, y and z     ",
            "13": "13  \u00a9 ucles 2011 0620/12/m/j/11 [turn over  34 which two substances, when reacted together, would form a salt that contains two of the  essential elements provided by fertilisers?  a potassium hydroxide and nitric acid  b potassium hydroxide and sulfuric acid  c sodium hydroxide and nitric acid  d sodium hydroxide and sulfuric acid      35 statement 1: alloying iron with other materials to form stainless steel prevents iron from rusting   by excluding oxygen.    statement 2: painting, oiling and electroplating are all methods of preventing iron from rusting.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     36 what is the main constituent of natural gas?  a carbon dioxide  b ethane  c hydrogen  d methane    37 what is not essential for the formation of ethanol by fermentation?  a light  b sugar  c yeast  d water    ",
            "14": "14  \u00a9 ucles 2011 0620/12/m/j/11  38 which industrial process is shown in the diagram?    crude oil vapour bitumenwaste gases petrol paraffin diesellubricating oils     a cracking  b fermentation  c fractional distillation  d polymerisation      39 the diagram shows the structures of three compounds.    o c hho h c hh c hh hho c chh c h     why do these three compounds belong to the same homologous series?  a they all contain carbon, hydrogen and oxygen.  b they all contain the same functional group.  c they are all carbon based molecules.  d they are all flammable liquids.     ",
            "15": "15  \u00a9 ucles 2011 0620/12/m/j/11  40 compounds containing five carbon atoms in a molecule may have names beginning with \u2018pent\u2026\u2019.    what is the name of the compound shown?    key = carbon = oxygen= hydrogen     a pentane  b pentanoic acid  c pentanol  d pentene     ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2011 0620/12/m/j/11   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s11_qp_13.pdf": {
            "1": "    this document consists of 16 printed pages.  ib11 06_0620_13/fp  \u00a9 ucles 2011  [turn over       *8339598569* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  may/june 2011       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2011 0620/13/m/j/11  1 the diagrams show the arrangement of particles in three different physical states of substance x.    state 1 state 2 state 3    which statement about the physical states of substance x is correct?  a particles in state 1 vibrate about fixed positions.  b state 1 changes to state 2 by diffusion.  c state 2 changes directly to state 3 by condensation.  d the substance in stage 3 has a fixed volume.    2 in the diagrams, circles of different sizes represent atoms of different elements.    which diagram represents hydrogen chloride gas?    b ac d       3 the diagram shows part of the periodic table.    a cb d     which element is correctly matched with its electronic structure?     electronic structure  a 2,8,1  b 2,4  c 2,8,2  d 2,8   ",
            "3": "3  \u00a9 ucles 2011 0620/13/m/j/11 [turn over  4 an aqueous solution is coloured.    which method of separation would show that the solution contains ions of different colours?  a chromatography  b crystallisation  c distillation  d filtration     5 the table gives the solubility of four substances in ethanol and in water.    a mixture containing all four substances is added to ethanol, stirred and filtered.    the solid residue is added to water, stirred and filtered.    the filtrate is evaporated to dryness, leaving a white solid.    which is the white solid?    solubility in    ethanol water  a insoluble insoluble  b insoluble soluble  c soluble insoluble  d soluble soluble     6 which two elements react together to form an ionic compound?    element electronic structure  w 2,4  x 2,8  y 2,8,1  z 2,8,7    a w and x b x and y c y and z d z and w     ",
            "4": "4  \u00a9 ucles 2011 0620/13/m/j/11  7 electricity is passed through concentrated aqueous sodium chloride, as shown.    +\u2013positive electrodenegative electrode concentrated aqueous sodiumchloridecarbon rods     what is the test for the gas formed at the positive electrode?  a bleaches damp litmus paper  b \u2018pops\u2019 with a lighted splint  c relights a glowing splint  d turns damp red litmus paper blue     8 electricity from a power station passes through overhead cables to a substation and then to a  school where it is used to electrolyse concentrated hydrochloric acid using inert electrodes.    which substances are used for the overhead cables and for the electrodes?     overhead cables electrodes  a aluminium copper  b aluminium platinum  c copper platinum  d platinum aluminium      9 the nucleon number and proton number of the lithium atom are shown by the symbol li7 3.    what is the correct symbol for the lithium ion in lithium chloride?  a 6 2li\u2212 b 6 3li+ c 7 3li+ d 7 3li\u2212     ",
            "5": "5  \u00a9 ucles 2011 0620/13/m/j/11 [turn over  10 three processes are listed.    burning methane in air  radioactive decay of 235u  reacting hydrogen with oxygen.    which statements about these processes are correct?    1 hydrogen and methane are being used as fuels.  2 all the processes involve oxidation.  3 all the processes are used to produce energy.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3      11 which statement about the electrolysis of molten lead( ii) bromide is correct?  a a colourless gas is seen at the cathode.  b a grey metal is seen at the anode.  c a red  / brown gas is seen at the anode.  d a red  / brown metal is seen at the cathode.      12 what is the relative molecular mass ( mr) of hno 3?  a 5 b 31 c 32 d 63      13 the equation for the effect of heat on hydrated sodium carbonate is as shown.    na2co 3.10h 2o(s)  na 2co 3(s) + 10h 2o(g)    statements made by four students about the reaction are given.    p anhydrous sodium carbonate is formed.  q steam is formed.  r there is a colour change from blue to white.  s the reaction is reversible.    which students\u2019 statements are correct?  a p, q and r only  b p, q and s only  c q, r and s only  d p, q, r and s    ",
            "6": "6  \u00a9 ucles 2011 0620/13/m/j/11  14 the apparatus shown can be used to measure the rate of some chemical reactions.    gas syringe     for which two reactions would the apparatus be suitable?    reaction 1 agno 3(aq) + hc l (aq) \u2192 agc l (s) + hno 3(aq)  reaction 2 2h 2o2(aq) \u2192 2h 2o(l) + o 2(g)  reaction 3 mgo(s) + 2hc l (aq) \u2192 mgc l 2(aq) + h 2o(l)  reaction 4 znco 3(s) + 2hc l (aq) \u2192 znc l 2(aq) + co 2(g) + h 2o(l)    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      15 a student investigates the rate of reaction between magnesium and excess sulfuric acid.     the volume of hydrogen given off in the reaction is measured over time.    the graph shows the results of two experiments, r and s.    r svolume of hydrogen given off time    which change in conditions would cause the difference between r and s?  a a catalyst is added in s.  b the acid is more concentrated in r than in s.  c the magnesium is less finely powdered in r than in s.  d the temperature in r is lower than in s.     ",
            "7": "7  \u00a9 ucles 2011 0620/13/m/j/11 [turn over  16 butane, ethanol and hydrogen are fuels.    which substances produce both carbon dioxide and water when used as a fuel?     butane ethanol hydrogen  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0017     17 x is a monatomic gas.    gas x     which statement about x is correct?  a x burns in air.  b x is coloured.  c x is unreactive.  d x will displace iodine from potassium iodide.     18 the equation shows the reaction betw een a halogen and aqueous bromide ions.    x 2 + 2br\u2013(aq) \u2192 2x\u2013(aq) + br 2  \u20261\u2026 \u20262\u2026 \u20263\u2026    which words correctly complete gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     ",
            "8": "8  \u00a9 ucles 2011 0620/13/m/j/11  19 carbon dioxide is an acidic oxide that reacts with aqueous calcium hydroxide.    which type of reaction takes place?  a decomposition  b fermentation  c neutralisation  d oxidation     20 a solution contains barium ions and silver ions.    what could the anion be?  a chloride only  b nitrate only  c sulfate only  d chloride or nitrate or sulfate      21 a mixture containing two anions was tested and the results are shown below.    test result  dilute nitric acid added   effervescence of a gas which  turned limewater milky  dilute nitric acid added, followed  by aqueous silver nitrate yellow precipitate formed      which anions were present?  a carbonate and chloride  b carbonate and iodide  c sulfate and chloride  d sulfate and iodide    22 which is not a typical property of an acid?  a they react with alkalis producing water.  b they react with all metals producing hydrogen.  c they react with carbonates producing carbon dioxide.  d they turn litmus paper red.    ",
            "9": "9  \u00a9 ucles 2011 0620/13/m/j/11 [turn over  23 the diagram shows a section of the periodic table.    w vx z yi ii iii iv v vi vii 0     which elements will conduct electricity at room temperature?  a v, w and x b v, y and w c w, x and z d y and z    24 water from a reservoir flows to the water works where purification processes 1 takes place  followed by process 2.    what are purification processes 1 and 2?     purification  process 1 purification  process 2  a chlorination filtration  b filtration chlorination  c fractional distillation filtration  d filtration fractional distillation      25 the properties of a metal are important in deciding its use.    which row lists a property that is not correct for the use given?     use of the metal metal property needed  a aluminium in aircraft wings low density  b aluminium in food containers resists corrosion  c mild steel in car bodies high density  d stainless steel in cutlery does not rust     ",
            "10": "10  \u00a9 ucles 2011 0620/13/m/j/11  26 brass is an alloy of copper and zinc.    which statement is correct?  a brass can be represented by a chemical formula.  b brass is formed by a chemical reaction between copper and zinc.  c the alloy will dissolve completely in dilute hydrochloric acid.  d the zinc in the alloy will dissolve in dilute hydrochloric acid.     27 which statement is correct for the element of proton number 19?  a it is a gas that dissolves in water.  b it is a hard metal that is not very reactive with water.  c it is a non-metal that burns quickly in air.  d it is a soft metal that is highly reactive with water.    28 which row describes the conditions used to make steel from the iron produced by a blast  furnace?     calcium oxide  (lime) oxygen heat  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017     ",
            "11": "11  \u00a9 ucles 2011 0620/13/m/j/11 [turn over  29 the table shows the results of adding three metals, p, q and r, to dilute hydrochloric acid and to  water.    metal dilute hydrochloric acid water  p hydrogen produced hydrogen produced  q no reaction no reaction  r hydrogen produced no reaction    what is the order of reactivity of the metals?     most reactive  least reactive  a p r q  b p q r  c r q p  d r p q      30 which substance is a metal?     electrical conductivity  (solid) electrical conductivity  (molten)  a high high  b high low  c low high  d low low      31 greenhouse gases may contribute to climate change.     two of these gases are emitted into the atmosphere as a result of processes within animals.    gas \u2026\u20261\u2026\u2026 is produced by process \u2026\u20263\u2026\u2026 .  gas \u2026\u20262\u2026\u2026 is produced by process \u2026\u20264\u2026\u2026 .    which words correctly complete gaps 1, 2, 3 and 4?     1 2 3 4  a co c 2h6 digestion respiration  b co c 2h6 respiration digestion  c co 2 ch 4 digestion respiration  d co 2 ch 4 respiration digestion     ",
            "12": "12  \u00a9 ucles 2011 0620/13/m/j/11  32 the diagram shows the composition by volume of air.    x    what is x?  a argon  b carbon dioxide  c nitrogen  d oxygen     33 the table gives the composition of the atmosphere of four newly discovered planets.    planet composition of atmosphere  w argon, carbon dioxide and oxygen  x argon, nitrogen and oxygen  y argon, carbon dioxide and methane  z methane, nitrogen and oxygen    on which planets is the greenhouse effect likely to occur?  a w only  b w, x and z  c w and y only  d w, y and z    ",
            "13": "13  \u00a9 ucles 2011 0620/13/m/j/11 [turn over  34 which two substances, when reacted together, would form a salt that contains two of the  essential elements provided by fertilisers?  a potassium hydroxide and nitric acid  b potassium hydroxide and sulfuric acid  c sodium hydroxide and nitric acid  d sodium hydroxide and sulfuric acid      35 statement 1: alloying iron with other materials to form stainless steel prevents iron from rusting    by excluding oxygen.    statement 2: painting, oiling and electroplating are all methods of preventing iron from rusting.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.    36 what is the main constituent of natural gas?  a carbon dioxide  b ethane  c hydrogen  d methane    37 what is not essential for the formation of ethanol by fermentation?  a light  b sugar  c yeast  d water    ",
            "14": "14  \u00a9 ucles 2011 0620/13/m/j/11  38 which industrial process is shown in the diagram?    crude oil vapour bitumenwaste gases petrol paraffin diesellubricating oils     a cracking  b fermentation  c fractional distillation  d polymerisation     39 the diagram shows the structures of three compounds.    o c hho h c hh c hh hho c chh c h     why do these three compounds belong to the same homologous series?  a they all contain carbon, hydrogen and oxygen.  b they all contain the same functional group.  c they are all carbon based molecules.  d they are all flammable liquids.     ",
            "15": "15  \u00a9 ucles 2011 0620/13/m/j/11  40 compounds containing five carbon atoms in a molecule may have names beginning with \u2018pent\u2026\u2019.    what is the name of the compound shown?    key = carbon = oxygen= hydrogen     a pentane  b pentanoic acid  c pentanol  d pentene    ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.   \u00a9 ucles 2011 0620/13/m/j/11   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements  "
        },
        "0620_s11_qp_21.pdf": {
            "1": "for examiner\u2019s use 1 2 3 total4 5 6 7 8read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 may/june 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib11 06_0620_21/4rp\u00a9 ucles 2011 *4887369687*",
            "2": "2 0620/21/m/j/11 \u00a9 ucles 2011for examiner\u2019s use1  the structures of some substances containing nitrogen are shown below. ab dec no3\u2013k+ k+no3\u2013k+ k+no3\u2013 no3\u2013k+ n cl clcln hh h n o on n   answer the following questions by choosing from the structures a, b, c, d or e.  you can use each structure once, more than once or not at all.   which structure represents  (a)  an acidic oxide,  (b)  an ionic giant structure,  (c)  a gas which turns moist litmus paper blue,  (d)  a compound which is formed under conditions  of high temperature and pressure in car engines, (e)  a molecule containing halogen atoms,  (f)  a salt? [total: 6]",
            "3": "3 0620/21/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use2  vanadium has two isotopes. 50 23v5123v  (a)  de\ufb01 ne the term isotope .   ...    ... ..  [1]  (b)  an atom contains protons, electrons and neutrons.   complete the table to show the number of protons, electrons and neutrons in these two isotopes of vanadium. isotopenumber of protonsnumber of electronsnumber of neutrons 5023v 23 23 5123v 28 [3]  (c)  complete these sentences using words from the list.  cancer extra industry in \ufb02 uenza medicine non   two types of isotopes are radioactive and ..-radioactive. radioactive  isotopes are used in .. for treating patients with .. . [3]  (d) vanadium is a transition element.   which two of these statements about vanadium are correct?   tick two boxes.  vanadium is a non-metal  vanadium conducts electricity  vanadium has a low melting point  vanadium is less dense than sodium compounds of vanadium are coloured [2] [total: 9]",
            "4": "4 0620/21/m/j/11 \u00a9 ucles 2011for examiner\u2019s use3  water is present in the atmosphere, the seas and in ice and snow.  (a)  describe a chemical test for water.  test     result  .. .  [2]  (b)  state one use of water in industry.   ... ..  [1]  (c)  water is a good solvent.   what do you understand by the term solvent  ?   ... ..  [1]  (d)  water vapour in the atmosphere reacts with sulfur dioxide, so2, to produce acid rain.  (i)  state one source of sulfur dioxide.   . .  [1]  (ii)  state two adverse effects of acid rain.  1.  .. ..  2.  ..   [2]  (iii)  calculate the relative molecular mass of sulfur dioxide. [1]  (e)  water from lakes and rivers can be treated to make the water safer to drink.   describe two of the steps in water puri \ufb01 cation.   for each of these steps, give an explanation of its purpose.  step 1  .. ..   ...   step 2  .. ..   ... ..  [4]",
            "5": "5 0620/21/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (f)   water is formed when hydrogen burns in air.  (i)  state the percentage of oxygen present in the air.   . .  [1]  (ii)  when 8  g of hydrogen is burned in excess air, 72  g of water is formed.   what mass of hydrogen needs to be burnt to produce 252  g of water? [1] [total: 14]",
            "6": "6 0620/21/m/j/11 \u00a9 ucles 2011for examiner\u2019s use4  the structures of some organic compounds are shown below. nc hh c hhdc h hh cc hhh hha c h hh co h hhec h hbr br ch hc c hh cc hhhhb  (a)  which one of these structures represents  (i)  a polymer,  (ii)  an unsaturated hydrocarbon,  (iii)  the product of the catalytic addition of steam to ethene,  (iv)  a product of the addition of aqueous bromine to ethene? [4]  (b) (i)   balance the equation for the complete combustion of compound a, c3h8. c3h8  +  o2  \u2192  3co2  +  h2o [2]  (ii)  state the name of two substances formed when compound a undergoes incomplete  combustion.  .  and  . [2] (c)  complete the structure of ethanoic acid to show all atoms and bonds. c h hh [1] [total: 9]",
            "7": "7 0620/21/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use5  concentrated hydrochloric acid can be electrolysed using the apparatus shown. concentrated hydrochloric acid \u2013 +negative electrode positive electrode  (a)  what do you understand by the term electrolysis  ?   ...    ... ..  [1]  (b)  what is the name given to the positive electrode?   put a ring around the correct answer.  anion anode cathode cation electrolyte [1]  (c)  state the name of the gas given off at the negative electrode.   ... ..  [1]  (d)  complete the following sentence about electrolysis using words from the list.  inert magnesium platinum reactive solid   electrodes made of graphite or .. are generally used in electrolysis  because they are .. . [2]",
            "8": "8 0620/21/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (e)   when concentrated hydrochloric acid is electrolysed, chlorine is released at the positive  electrode.  (i)  draw the arrangement of the electrons in an atom of chlorine. [1]  (ii)  draw the electronic structure of a chlorine molecule.   show only the outer electron shells. [2]  (iii)  describe a test for chlorine.  test   .  result    [2]  (f)  hydrochloric acid reacts with the base calcium hydroxide.  (i)  complete the word equation for this reaction. hydrochloric acid  +  calcium hydroxide  \u2192  .  +  .  . [2]  (ii)  hydrochloric acid also reacts with zinc.   complete the symbol equation for this reaction. zn  +  hc l  \u2192  znc l 2  +   [2] [total: 14]",
            "9": "9 0620/21/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use6  a student observed the reaction of various metals with both cold water and steam. her results  are shown below. metal reaction with cold water reaction with steam calcium reacts rapidly reacts very rapidly copper no reaction no reaction magnesium reacts very slowly reacts rapidly zinc no reaction reacts  (a) (i)  put these metals in order of their reactivity. least reactive most reactive [1]  (ii)  iron is a metal between zinc and copper in the reactivity series.   predict the reactivity of iron with  cold water,  . steam.  ..  [2 ]  (b)  the equation for the reaction of zinc with steam is: zn  +  h 2o  \u2192  zno  +  h2   write a word equation for this reaction. [1]  (c)  state three  physical properties which are characteristic of most  metals.  1.  ...   2.  ...   3.  ... ..  [3]",
            "10": "10 0620/21/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (d)  some properties of the group i metals are shown in the table. metalmelting point / \u00b0chardnessdensity / g per cm3 lithium fairly hard 0.53 sodium 98 fairly soft potassium 63 soft rubidium 39 very soft 1.53 caesium 29 extremely soft 1.88  (i)  estimate the melting point of lithium.   . .  [1]  (ii)  how does the hardness of these metals change down the group?   . .  [1]  (iii)  estimate the density of potassium.   . .  [1] [total: 10]",
            "11": "11 0620/21/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use7  the diagram shows a basic oxygen converter. this is used to convert impure iron from the  blast furnace into steel. during this process, some of the impurities in the iron are converted into a slag.  (a)  label the diagram to show each of the following:  \u25cf where the oxygen enters;  \u25cf the slag;  \u25cf the molten steel. [3]  (b)  in the converter, the oxygen oxidises sulfur, carbon and phosphorus to their oxides.  (i)  explain why sulfur dioxide and carbon dioxide are easily removed from the  converter.   . .  [1]  (ii)  explain how calcium oxide is used to remove phosphorus( v) oxide from the  converter.   . ...   . ...   . ...   . .  [3]",
            "12": "12 0620/21/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (c)  stainless steel is an alloy.  (i)  which one of the diagrams, a, b, c or d, best represents an alloy?  put a ring around the correct answer. a bcd [1]  (ii)  state one use of stainless steel.   . .  [1] [total: 9]",
            "13": "13 0620/21/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use8  bromine is a red-brown liquid. when warmed, it forms an orange vapour.  (a)  describe what happens to the arrangement and motion of the particles when bromine  changes state from a liquid to a vapour.   ...    ...    ...    ... ..  [3]  (b)  bromine can be obtained from bromide ions in seawater.  (i)  the symbol equation for this reaction is: cl 2  +  2br  \u2013  \u2192  2c l \u2013  +  br2   complete the word equation for this reaction. ..  +  bromide ions  \u2192  ..  +  .. [1]  (ii)  bromine is very volatile, so it can be removed from solution by bubbling air through  the solution.   what do you understand by the term volatile  ?   . .  [1]  (c)  hydrogen reacts with bromine in the presence of a hot platinum catalyst to form hydrogen  bromide.  (i)  de\ufb01 ne the term catalyst .   . .  [1]  (ii)  hydrogen bromide reduces hydrogen peroxide, h2o2. 2hbr  +  h2o2  \u2192  br2  +  2h2o   explain how this equation shows that hydrogen peroxide is reduced.   . ...   . .  [1]",
            "14": "14 0620/21/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (iii)  a solution of hydrogen bromide in water is called hydrobromic acid.   hydrobromic acid has similar reactions to hydrochloric acid.   state the names of three  products formed when hydrobromic acid reacts with sodium  carbonate.   . .  [2] [total: 9]",
            "15": "15 0620/21/m/j/11 \u00a9 ucles 2011blank page",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/21/m/j/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s11_qp_22.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.for examiner\u2019s use 1 2 3 total4 5 6 7chemistry  0620/22   paper 2 may/june 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib11 06_0620_22/4rp\u00a9 ucles 2011 *0710019578*",
            "2": "2 0620/22/m/j/11 \u00a9 ucles 2011for examiner\u2019s use1  the diagram shows the electronic structures of six atoms. a b c d e f  (a)  answer the following questions by choosing from the structures a, b, c, d, e or f.  you can use each structure once, more than once or not at all.   which structure represents  (i)  an atom in period 3 of the periodic table,  (ii)  an atom containing six protons,  (iii)  an atom of a group i metal,  (iv)  an atom of phosphorus,  (v)  an atom with six electrons in its outer shell,  (vi)  an atom with a complete outer shell of electrons? [6]  (b)  atoms d and f can combine to form a covalent molecule.  (i)  complete the following sentence using words from the list.  atoms electrons ions neutrons solids   a covalent bond is formed when a pair of .. is shared between two .. . [2]  (ii)  which one of the following structures represents an ionic compound?  tick one box. \u2013+ \u2013+\u2013 + \u2013 +\u2013+ \u2013+\u2013 + \u2013 + [1] [total: 9]",
            "3": "3 0620/22/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use2  many metal oxides can be reduced with carbon.   the table shows the temperatures required to produce different metals from their oxides by  heating with carbon. reaction temperature  / \u00b0c aluminium oxide  \u2192  aluminium 2100 iron oxide  \u2192  iron 425 nickel oxide  \u2192  nickel 475 zinc oxide  \u2192  zinc 925  (a) (i)   use the information in the table to arrange aluminium, iron, nickel and zinc in order  of their reactivity. least reactive most reactive [1]  (ii)  suggest why aluminium is extracted by electrolysis rather than by heating with  carbon.   . ...   . .  [1]  (iii)  state the name of the main ore of aluminium.   . .  [1]  (b)  iron is extracted by heating iron ore with carbon in a blast furnace.  (i)  apart from iron ore and carbon (coke), state the names of two other raw materials  used in the blast furnace for the extraction of iron.  .  and  . [2] (ii)  complete this equation for the reaction of iron( iii) oxide with carbon. fe 2o3  +  co  \u2192  fe  +  3co2 [2]  (iii)   in the blast furnace, carbon dioxide reacts with red hot carbon to form carbon  monoxide. co2  +  c  \u2192  2co  which substance gets reduced during this reaction? explain your answer.  . ...   . .  [2]",
            "4": "4 0620/22/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (iv)  state one adverse effect of carbon monoxide on health.   . .  [1]  (v)  the reaction between carbon dioxide and red hot carbon is endothermic.    what do you understand by the term endothermic  ?   . .  [1]  (c)  iron is usually made into steel alloys.  (i)  what do you understand by the term alloy  ?   . ...   . .  [1]  (ii)  mild steel is an alloy.   state one use of mild steel.   . .  [1] [total: 13]",
            "5": "5 0620/22/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use3  the pie chart shows the composition of air. oxygennitrogen other gases  (a) (i)   what is the percentage of nitrogen in the air?   . .  [1]  (ii)  apart from nitrogen and oxygen, state the names of two gases present in unpolluted  air.  .  and  . [2] (b)  the percentage of oxygen in air can be found using the apparatus shown below. air air gas syringe heatcopper wire   air is passed backwards and forwards over the heated copper using the syringes. the  copper reacts with oxygen in the air. copper  +  oxygen  \u2192  copper( ii) oxide   as the experiment proceeds, suggest what happens to  (i)  the total volume of air in the gas syringes,   . .  [1]  (ii)  the mass of the wire in the tube.   . .  [1]  (c)  state one use of copper.   ... ..  [1]",
            "6": "6 0620/22/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (d)  a steel spoon can be electroplated using the apparatus shown. steel spoon to be electroplatedcopper electrode electrolyte+ \u2013  give a description of this electroplating.  in your answer, refer to:  \u25cf a suitable electrolyte that can be used;  \u25cf the anode and the cathode;  \u25cf changes to the spoon.   ...    ...    ...    ...    ...    ... ..  [3] [total: 9]",
            "7": "7 0620/22/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use4  ethanol can be produced by fermentation or by the catalytic addition of steam to ethene.  (a) (i)   complete the word equation for fermentation. glucose  \u2192  ...  +  ethanol [1]  (ii)  state the conditions needed for fermentation.   . ...   . .  [2]  (b) (i)   complete the equation for the catalytic addition of steam to ethene by drawing the  structures of water and ethanol in the boxes. ch hch hc2h4c2h5oh h2o + \u2192 + \u2192 [2]  (ii)  ethene is an unsaturated hydrocarbon.   describe a test for an unsaturated hydrocarbon.  test   .  result    [2]  (c)  ethanol can be used as a fuel.   state the names of the products formed when ethanol undergoes complete  combustion.  .  and  . [2] (d)  complete these sentences using words from the list.  different      functional      homologous      similar      unreactive      unsaturated   ethanol is a member of the alcohol ... series.   all alcohols have .. chemical properties because they contain the same  .. group. [3] [total: 12]",
            "8": "8 0620/22/m/j/11 \u00a9 ucles 2011for examiner\u2019s use5  the structures of diamond and chlorine are shown below. = carbon atom = chlorine atomdiamond chlorine  (a)  describe the structure of these two substances.   use the list of words to help you.  covalent       diatomic       giant       macromolecule       molecule       structure  diamond  . ...   ...    ...   chlorine   .   ...    ... ..  [4]  (b)  the structure of a compound containing carbon and chlorine is shown below. c ccc cc cl clcl cl cl clcl cl clcl clcl   what is the molecular formula of this compound?   ... ..  [1]",
            "9": "9 0620/22/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)   chlorine is a halogen.  (i)  state the colour of chlorine.   . .  [1]  the table shows some properties of the halogens. element boiling point  / \u00b0cdensity in liquid  state  / g per cm3 colour \ufb02 uorine \u2013188 1.51 yellow chlorine \u201335 1.56 bromine \u20137 red-brown iodine +114 4.93 grey-black   use the information in the table to answer the following questions.  (ii)  predict the density of liquid bromine.   . .  [1]  (iii)  describe the trend in boiling point of the halogens down the group.   . .  [1]  (d) (i)   complete the word equation for the reaction of bromine with aqueous potassium  iodide. bromine  +  potassium iodide  \u2192  .  +  .  . [2]  (ii)  explain why bromine does not react with aqueous potassium chloride.   . .  [1]  (e)  potassium chloride is an ionic substance but iodine is a molecular substance.  how do most ionic and molecular substances differ in their  solubility in water,   .   ...   electrical conductivity?  ..   ... ..  [2] [total: 13]",
            "10": "10 0620/22/m/j/11 \u00a9 ucles 2011for examiner\u2019s use6  iron( ii) sulfate is a light green salt.  (a)  describe how you can prepare pure dry crystals of iron( ii) sulfate from iron powder and  dilute sulfuric acid.   ...    ...    ...    ...    ... ..  [3]  (b)  the formula for iron( ii) sulfate is feso4.7h2o.  (i)  what is the meaning of the symbol ( ii) in this formula?   . .  [1]  (ii)  describe a test for iron( ii) ions.  test   .  result    [3]  (iii)  a student warmed a sample of iron( ii) sulfate, feso4.7h2o, in a test-tube. drops  of a colourless liquid appeared at the mouth of the test-tube and the iron( ii) sulfate  turned white.   explain these observations.   . .  [1]  (iv)  the reaction in part (iii) can be reversed.   write down the symbol which shows that a reaction is reversible. [1]  (c)  many centuries ago, sulfuric acid was made from iron( ii) sulfate.   sulfuric acid is a typical acid.  (i)  describe what you would observe when sulfuric acid is added to  blue litmus paper,  .. iron powder.  .  [2]",
            "11": "11 0620/22/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (ii)  farmers can add a solution of dilute sulfuric acid to their \ufb01 elds if the soil is too  alkaline.   explain why farmers do not want their \ufb01 elds to become too alkaline.   . .  [1]  (iii)  which one of the following ph values best describes a solution which is slightly  alkaline?   put a ring around the correct answer.  ph 1 ph 6 ph 7 ph 8 ph 14 [1]  (iv)  give the name of a compound which farmers add to the soil to make it less acidic.   . .  [1] [total: 14]",
            "12": "12 0620/22/m/j/11 \u00a9 ucles 2011for examiner\u2019s use7  smelling salts are sometimes used to \u2018wake up\u2019 people who feel faint.   the main chemical in smelling salts is ammonium carbonate. ammonium carbonate breaks  down slowly at room temperature to release ammonia gas. ammonium carbonate  \u2192  ammonia  +  carbon dioxide  +  water  (a)  a few crystals of ammonium carbonate were put on a bench at the front of a classroom. ammonium carbonate abc   the students in row a could smell the ammonia 10 seconds after the smelling salts  had been put on the bench. the students in row c could smell the ammonia after 40  seconds.  (i)  suggest how long it took the students in row b to smell the ammonia.   . .  [1]  (ii)  explain these results using ideas about moving particles.   . ...   . ...   . .  [3]  (b)  ammonium carbonate has the formula (nh4)2co3.   calculate the relative formula mass of ammonium carbonate. [1]  (c)  ammonia is used to make fertilisers such as ammonium sulfate.  (i)  state the names of the three  chemical elements, essential for plant growth, that are  present in fertilisers.   . .  [3]",
            "13": "13 0620/22/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (ii)  which one of the following statements about ammonium sulfate is correct?   tick one box.   when ammonium sulfate is heated with sodium hydroxide, carbon  dioxide is given off.   when ammonium sulfate is added to a solution of barium chloride,  a blue precipitate is formed.  ammonium sulfate can be made by adding sulfuric acid to ammonia. farmers add ammonium sulfate to the soil to make it alkaline. [1]  (d)  ammonium carbonate is made by heating ammonium sulfate with excess calcium  carbonate. ammonium sulfate  +  calcium carbonate  \u2192  ammonium carbonate  +  calcium sulfate   when 132  g of ammonium sulfate is reacted with calcium carbonate, 96  g of ammonium  carbonate is formed.   calculate the mass of ammonium sulfate needed to make 240  g of ammonium  carbonate. [1] [total: 10]",
            "14": "14 0620/22/m/j/11 \u00a9 ucles 2011blank page",
            "15": "15 0620/22/m/j/11 \u00a9 ucles 2011blank page",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/22/m/j/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s11_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) may/june 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib11 06_0620_31/4rp\u00a9 ucles 2011 *6145201818* for examiner\u2019s use 3 4 5 total6 7 81 2",
            "2": "2 0620/31/m/j/11 \u00a9 ucles 2011for examiner\u2019s use1  the following techniques are used to separate mixtures.  a  simple distillation b  fractional distillation c  evaporation  d  chromatography e  \ufb01 ltration f  diffusion   from this list, choose the most suitable technique to separate the following.  (a)  methane from a mixture of the gases, methane and ethane .. [1]  (b)  water from aqueous magnesium sulfate .. [1]  (c)  glycine from a mixture of the amino acids, glycine and lysine ... [1]  (d)  iron \ufb01 lings from a mixture of iron \ufb01 lings and water .. [1]  (e)  zinc sulfate crystals from aqueous zinc sulfate .. [1]  (f)  hexane from a mixture of the liquids, hexane and octane .. [1] [total: 6] 2  selenium and sulfur are in group vi. they have similar properties.  (a)  one of the main uses of selenium is in photoelectric cells. these cells can change light  into electrical energy.  (i)  name a process which can change light into chemical energy.   . ...  (ii)  name a device which can change chemical energy into electrical energy.   . .  [2]  (b)  the electron distribution of a selenium atom is 2 + 8 + 18 + 6.  (i)  selenium forms an ionic compound with potassium. draw a diagram which shows the formula of this ionic compound, the charges on the ions and the arrangement of the valency  electrons around the negative ion.  use o to represent an electron from an atom of potassium. use x to represent an electron from an atom of selenium. [3]",
            "3": "3 0620/31/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (ii)  draw a diagram showing the arrangement of the valency electrons in one molecule  of the covalent compound selenium chloride.  use x to represent an electron from an atom of selenium. use o to represent an electron from an atom of chlorine. [3]  (iii)  predict two differences in the physical properties of these two compounds.   . ...   . .  [2]  (c)  the selenide ion reacts with water. se 2\u2013  +  h2o  \u2192  hse\u2013  +  oh\u2013  what type of reagent is the selenide ion in this reaction? give a reason for your choice.   ...    ... ..  [3] [total: 13] 3  iron from the blast furnace is impure. it contains about 4  % carbon and 0.5  % silicon. most  of this impure iron is used to make mild steel, an alloy of iron containing less then 0.25  %  carbon.  (a)  a jet of oxygen is blown through the molten iron in the presence of a base, usually  calcium oxide. explain how the percentage of carbon is reduced and how the silicon is removed.   ...    ...    ...    ... ..  [4]",
            "4": "4 0620/31/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (b) (i)   why are steel alloys used in preference to iron?   . .  [1]  (ii)  state a use of the following alloys.  mild steel  .. .    stainless steel  ..  [2] (c)  both iron and steel have typical metallic structures - a lattice of positive ions and a sea  of electrons.  (i)  suggest an explanation for why they have high melting points.   . ...   . ...   . .  [2]  (ii)  explain why, when a force is applied to a piece of steel, it does not break but just  changes its shape.   . ...   . .  [2] [total: 11] 4  a major ore of zinc is zinc blende, zns. a by-product of the extraction of zinc from this ore is  sulfur dioxide which is used to make sulfuric acid.  (a) (i)  zinc blende is heated in air. zinc oxide and sulfur dioxide are formed. write the  balanced equation for this reaction.   . .  [2]  (ii)  zinc oxide is reduced to zinc by heating with carbon. name two other reagents  which could reduce zinc oxide.   . .  [2]  (iii)  the zinc obtained is impure. it is a mixture of metals. explain how fractional distillation  could separate this mixture.  zinc bp = 908  \u00b0c, cadmium bp = 765  \u00b0c, lead bp = 1751  \u00b0c   . ...   . .  [2]",
            "5": "5 0620/31/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (b)  sulfur dioxide is used to make sulfur trioxide in the contact process. 2so2(g)  +  o2(g)    2so3(g)   the forward reaction is exothermic. the conditions used are:  temperature: 450  \u00b0c  pressure: 2 atmospheres catalyst: vanadium( v) oxide   explain, mentioning both position of equilibrium and rate, why these conditions give the  most economic yield.   ...    ...    ...    ... ..  [4] [total: 10] 5  hydriodic acid, h i(aq), is a strong acid. its salts are iodides.  (a)  it has the reactions of a typical strong acid. complete the following equations.  (i) li  +  h i  \u2192    +  ... [1]  (ii) zinc carbonate++ + \u2192hydriodic acid..  ... [1]  (iii) mgo  +  h i  \u2192 +... ... [1]  (b)  two of the reactions in (a) are acid  / base and one is redox. which one is redox? explain  your choice.   ...    ...    ... ..  [2]  (c)  describe how you could distinguish between hydriodic, h i(aq), and hydrobromic, hbr(aq)  acids, by bubbling chlorine through these two acids.  result with hydriodic acid  .. result with hydrobromic acid  ...  [2]",
            "6": "6 0620/31/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (d)  20.0  cm3 of aqueous sodium hydroxide, 2.00  mol  / dm3, was placed in a beaker. the  temperature of the alkali was measured and 1.0  cm3 portions of hydriodic acid were  added. after each addition, the temperature of the mixture was measured. typical results are shown on the graph. temperature volume of acid added18.0  cm3 naoh(aq)  +  h i(aq)  \u2192  nai(aq)  +  h2o(l)  (i)  explain why the temperature increases rapidly at \ufb01 rst then stops increasing.   . ...   . .  [2]  (ii)  suggest why the temperature drops after the addition of 18.0  cm3 of acid.   . .  [1]  (iii)  in another experiment, it was shown that 15.0  cm3 of the acid neutralised 20.0  cm3 of  aqueous sodium hydroxide, 1.00  mol  / dm3. calculate the concentration of the acid.   . ...   . .  [2] [total: 12] 6  the structural formula of a butanol is given below. ch3 \u2014 ch2 \u2014 ch2 \u2014 ch2 \u2014 oh  (a)  butanol can be made from petroleum and also by fermentation.  (i)  describe the chemistry of making butanol from petroleum by the following route. petroleum  \u2192  butene  \u2192  butanol   . ...   . ...   . .  [3]",
            "7": "7 0620/31/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (ii)  explain, in general terms, what is meant by fermentation .   . ...   . ...   . ...   . .  [3]  (b)  butanol can be oxidised to a carboxylic acid by heating with acidi \ufb01 ed potassium  manganate( vii). give the name and structural formula of the carboxylic acid.  name  ...  [1 ]  structural formula [1]  (c)  butanol reacts with ethanoic acid to form a liquid, x, which has the sweet smell of  bananas. its empirical formula is c3h6o and its mr is 116.  (i)  what type of compound is liquid x?   . .  [1]  (ii)  give the molecular formula of liquid x.   . .  [1]  (iii)  draw the structural formula of x. show all the individual bonds. [2] [total: 12]",
            "8": "8 0620/31/m/j/11 \u00a9 ucles 2011for examiner\u2019s use7  excess hydrochloric acid was added to powdered zinc. the hydrogen evolved was collected  and its volume measured every 20 seconds.   the experiments were repeated at the same temperature using the same number of moles  of powdered magnesium and aluminium. volume of hydrogen timemetal cmetal b metal a  (a)  identify metals a, b and c by choosing from zinc, magnesium and aluminium. give a  reason for each choice.  metal a  .   ...   metal b  .   ...   metal c  .   ... ..  [5]  (b)  using \u2018moles\u2019, explain why two of the metals form the same volume of hydrogen but the  third metal forms a larger volume.   ...    ...    ... ..  [3] [total: 8]",
            "9": "9 0620/31/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use8  there are two types of polymerisation - addition and condensation.  (a)  explain the difference between them.   ...    ...    ... ..  [2]  (b)  poly(dichloroethene) is used to package food. draw its structure. the structural formula  of dichloroethene is shown below. cccl clh h [2]  (c)  the polymer known as pva is used in paints and adhesives. its structural formula is  shown below. ch2ch oocch3oocch3ch2ch   deduce the structural formula of its monomer. [1]",
            "10": "10 0620/31/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (d)  a condensation polymer can be made from the following monomers. hooc(ch2)4cooh  and  h2n(ch2)6nh2  draw the structural formula of this polymer. [3] [total: 8]",
            "11": "11 0620/31/m/j/11blank page \u00a9 ucles 2011",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/31/m/j/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s11_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) may/june 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib11 06_0620_32/4rp\u00a9 ucles 2011 *8533856820* for examiner\u2019s use 3 4 5 total6 7 81 2",
            "2": "2 0620/32/m/j/11 \u00a9 ucles 2011for examiner\u2019s use1  choose an element from the list below which best \ufb01 ts the description.  rb fe si i p sr  (a)  an element which reacts with cold water.  ... [1]  (b)  it is a solid at room temperature and exists as diatomic molecules, x2. ... [1]  (c)  it can form two oxides, xo and x2o3. ... [1]  (d)  this element has a hydride of the type xh3. ... [1]  (e)  it has a macromolecular structure similar to that of carbon. ... [1] [total: 5] 2  tin is an element in group iv.  (a)  the position of tin in the reactivity series is: zinc iron tin copper  (i)  for each of the following, decide if a reaction would occur. if there is a reaction,  complete the equation, otherwise write \u2018no reaction\u2019.  cu  +  sn2+  \u2192  ..  fe  +  sn2+  \u2192  ..  sn  +  zn2+  \u2192  .. [4]  (ii)  name the three  products formed when tin( ii) nitrate is heated.   . ...   . .  [2]  (b)  aqueous tin( ii) sulfate is electrolysed using carbon electrodes. this electrolysis is similar  to that of aqueous copper( ii) sulfate using carbon electrodes.  (i)  what is the product at the negative electrode (cathode)?   . .  [1]  (ii)  write the equation for the reaction at the positive electrode (anode).   . .  [2]  (iii)  name the acid formed in this electrolysis.   . .  [1]",
            "3": "3 0620/32/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  steel articles can be plated with tin or zinc to prevent rusting.   when the zinc layer is damaged exposing the underlying steel, it does not rust, but when  the tin layer is broken the steel rusts. explain.   ...    ...    ... ..  [4] [total: 14]",
            "4": "4 0620/32/m/j/11 \u00a9 ucles 2011for examiner\u2019s use3  the equation for the reaction between sodium thiosulfate and hydrochloric acid is given  below. na2s2o3(aq)  +  2hc l (aq)  \u2192  2nac l (aq)  +  s(s)  +  so2(g)  +  h2o(l)   the speed of this reaction was investigated using the following experiment. a beaker  containing 50  cm3 of 0.2  mol  / dm3 sodium thiosulfate was placed on a black cross. 5.0  cm3 of  2.0  mol  / dm3 hydrochloric acid was added and the clock was started. look down atcross on paper papersolution turns from colourless to cloudysodium thiosulfateand hydrochloric acid cross on paper view looking down   initially the cross was clearly visible. when the solution became cloudy and the cross could  no longer be seen, the clock was stopped and the time recorded.  (a)  the experiment was repeated with 25  cm3 of 0.2  mol  / dm3 sodium thiosulfate and 25  cm3  of water. typical results for this experiment and a further two experiments are given in the table. experiment 1234 volume of thiosulfate  / cm350 40 25 10 volume of water  / cm301 02 54 0 volume of acid  / cm35555 total volume  / cm355 55 55 55 time  / s 48 60 96 ..  (i)  explain why it is necessary to keep the total volume the same in all the  experiments.   . ...   . ...   . .  [2]  (ii)  complete the table. [1]",
            "5": "5 0620/32/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (iii)  how and why does the speed of the reaction vary from experiment 1 to 4?   . ...   . ...   . .  [3]  (b)  the idea of collisions between reacting particles is used to explain changes in the speed  of reactions. use this idea to explain the following results. volume of sodium thiosulfate  / cm325 25 volume of water  / cm325 25 volume of acid  / cm355 temperature  / \u00b0c2 0 4 2 time  / s9 6 4 0   ...    ...    ...    ... ..  [4] [total: 10]",
            "6": "6 0620/32/m/j/11 \u00a9 ucles 2011for examiner\u2019s use4  iron is extracted from its ore, hematite, in the blast furnace. slag molten ironairfirebrick liningwaste gases raw materials coke, ciron ore, fe 2o3 limestone, caco3   describe the reactions involved in this extraction. include in your description an equation for  a redox reaction and one for an acid  / base reaction.   ... ...   ... ...   ... ...   ... ...   ... .  [5] [total: 5]",
            "7": "7 0620/32/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use5  the diagram shows a simple cell. zinc electrode iron electrode bubbles of hydrogen dilute sulfuric acidvvoltmeter  (a)  write an equation for the overall reaction occurring in the cell.   ... ..  [2]  (b)  explain why all cell reactions are exothermic and redox.   ...    ...    ... ..  [3]  (c)  which electrode, zinc or iron, is the negative electrode? give a reason for your choice.   ...    ... ..  [2]  (d)  suggest two ways of increasing the voltage of this cell.   ...    ... ..  [2] [total: 9]",
            "8": "8 0620/32/m/j/11 \u00a9 ucles 2011for examiner\u2019s use6 (a)  methanol can be made from a mixture of carbon monoxide and hydrogen. co(g)  +  2h2(g)    ch3oh(g)   the forward reaction is exothermic.  (i)  explain why the concentration of methanol at equilibrium does not change.   . ...   . .  [2]  (ii)  suggest conditions, in terms of temperature and pressure, which would give a high  yield of methanol.   . ...   . .  [2]  (iii)  how would the conditions used in practice compare with those given in (ii)? give an  explanation of any differences.   . ...   . ...   . .  [2]  (b)  biodiesel is made from a vegetable oil by the following reaction. ++3ch3oh\u2192 3c17h35cooch3ch2oh choh ch2ohc17h35co2ch2 c17h35co2ch c17h35co2ch2 vegetable oil methanol biodiesel glycerol  (i)  what type of compound are vegetable oil and biodiesel?   . .  [1]  (ii)  what other useful product is made from vegetable oil by heating it with aqueous  sodium hydroxide?   . .  [1]  (iii)  suggest an explanation why making and using biodiesel has a smaller effect on  the percentage of carbon dioxide in the atmosphere than using petroleum-based diesel.   . ...   . ...   . .  [2]",
            "9": "9 0620/32/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  petroleum-based diesel is a mixture of hydrocarbons, such as octane and octene.  (i)  \u2018oct\u2019 means eight carbon atoms per molecule. draw a structural formula of an octene  molecule. [1]  (ii)  describe a test which would distinguish between octane and octene.  test   .  result with octane  ... result with octene  .  [3] [total: 14] 7  chlorine reacts with phosphorus to form phosphorus trichloride.  (a)  draw a diagram showing the arrangement of the valency  electrons in one molecule of  the covalent compound, phosphorus trichloride.  use x to represent an electron from a phosphorus atom. use o to represent an electron from a chlorine atom. [2]  (b)  phosphorus trichloride reacts with water to form two acids.  (i)  balance the equation for this reaction. pc l  3  +  ...h2o  \u2192  ...hc l  +  h3po3 [1]  (ii)  describe how you could show that phosphorus acid, h3po3, is a weaker acid than  hydrochloric acid.   . ...   . ...   . .  [3]",
            "10": "10 0620/32/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (iii)  two salts of phosphorus acid are its sodium salt, which is soluble in water, and its  calcium salt which is insoluble in water. suggest a method of preparation for each of these salts from aqueous phosphorus acid. specify any other reagent needed and brie\ufb02 y outline the method.  sodium salt    . ...   . ...   . .  [2]  calcium salt    . ...   . ...   . .  [2] [total: 10] 8  hydrocarbons are compounds which contain only carbon and hydrogen.  (a)  20  cm3 of a gaseous hydrocarbon was burned in 120  cm3 of oxygen, which is in excess.  after cooling, the volume of the gases remaining was 90  cm3. aqueous sodium hydroxide  was added to remove carbon dioxide, 30  cm3 of oxygen remained. all volumes were  measured at r.t.p..  (i)  explain why it is essential to use excess oxygen.   . ...   . .  [2]  (ii)  carbon dioxide is slightly soluble in water. why does it dissolve readily in the alkali,  sodium hydroxide?   . .  [1]  (iii)  complete the following.  volume of gaseous hydrocarbon = ...cm3  volume of oxygen used = .cm3  volume of carbon dioxide formed = .cm3 [2]  (iv)  use the above volume ratio to \ufb01 nd the mole ratio in the equation below and hence  \ufb01 nd the formula of the hydrocarbon.  cxhy(g)  +  o2(g)  \u2192  co2(g)  +  h2o(l) hydrocarbon formula =   [2]",
            "11": "11 0620/32/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (b)  alkanes are hydrocarbons and are generally unreactive. their reactions include  combustion, substitution and cracking.  (i)  chlorine reacts with butane in a substitution reaction. ch3 \u2014 ch2 \u2014 ch2 \u2014 ch3  +  c l 2  \u2192  ch3 \u2014 ch2 \u2014 ch2 \u2014 ch2 \u2014 cl  +  hc l   give the structural formula of another possible product of this reaction. [1]  (ii)  what is the essential condition for this reaction?   . .  [1]  (iii)  explain what is meant by cracking . give an example of a cracking reaction and  explain why the process is used.   . ...   . ...   . ...   . ...   . .  [4] [total: 13]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/32/m/j/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s11_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) may/june 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib11 06_0620_33/fp\u00a9 ucles 2011 *0026964373* for examiner\u2019s use 3 4 5 total6 7 81 2",
            "2": "2 0620/33/m/j/11 \u00a9 ucles 2011for examiner\u2019s use1  choose an element from the list below which best \ufb01 ts the description.  rb fe si i p sr  (a)  an element which reacts with cold water.  ... [1]  (b)  it is a solid at room temperature and exists as diatomic molecules, x2. ... [1]  (c)  it can form two oxides, xo and x2o3. ... [1]  (d)  this element has a hydride of the type xh3. ... [1]  (e)  it has a macromolecular structure similar to that of carbon. ... [1] [total: 5] 2  tin is an element in group iv.  (a)  the position of tin in the reactivity series is: zinc iron tin copper  (i)  for each of the following, decide if a reaction would occur. if there is a reaction,  complete the equation, otherwise write \u2018no reaction\u2019.  cu  +  sn2+  \u2192  ..  fe  +  sn2+  \u2192  ..  sn  +  zn2+  \u2192  .. [4]  (ii)  name the three  products formed when tin( ii) nitrate is heated.   . ...   . .  [2]  (b)  aqueous tin( ii) sulfate is electrolysed using carbon electrodes. this electrolysis is similar  to that of aqueous copper( ii) sulfate using carbon electrodes.  (i)  what is the product at the negative electrode (cathode)?   . .  [1]  (ii)  write the equation for the reaction at the positive electrode (anode).   . .  [2]  (iii)  name the acid formed in this electrolysis.   . .  [1]",
            "3": "3 0620/33/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  steel articles can be plated with tin or zinc to prevent rusting.   when the zinc layer is damaged exposing the underlying steel, it does not rust, but when  the tin layer is broken the steel rusts. explain.   ...    ...    ... ..  [4] [total: 14]",
            "4": "4 0620/33/m/j/11 \u00a9 ucles 2011for examiner\u2019s use3  the equation for the reaction between sodium thiosulfate and hydrochloric acid is given  below. na2s2o3(aq)  +  2hc l (aq)  \u2192  2nac l (aq)  +  s(s)  +  so2(g)  +  h2o(l)   the speed of this reaction was investigated using the following experiment. a beaker  containing 50  cm3 of 0.2  mol  / dm3 sodium thiosulfate was placed on a black cross. 5.0  cm3 of  2.0  mol  / dm3 hydrochloric acid was added and the clock was started. look down atcross on paper papersolution turns from colourless to cloudysodium thiosulfateand hydrochloric acid cross on paper view looking down   initially the cross was clearly visible. when the solution became cloudy and the cross could  no longer be seen, the clock was stopped and the time recorded.  (a)  the experiment was repeated with 25  cm3 of 0.2  mol  / dm3 sodium thiosulfate and 25  cm3  of water. typical results for this experiment and a further two experiments are given in the table. experiment 1234 volume of thiosulfate  / cm350 40 25 10 volume of water  / cm301 02 54 0 volume of acid  / cm35555 total volume  / cm355 55 55 55 time  / s 48 60 96 ..  (i)  explain why it is necessary to keep the total volume the same in all the  experiments.   . ...   . ...   . .  [2]  (ii)  complete the table. [1]",
            "5": "5 0620/33/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (iii)  how and why does the speed of the reaction vary from experiment 1 to 4?   . ...   . ...   . .  [3]  (b)  the idea of collisions between reacting particles is used to explain changes in the speed  of reactions. use this idea to explain the following results. volume of sodium thiosulfate  / cm325 25 volume of water  / cm325 25 volume of acid  / cm355 temperature  / \u00b0c2 0 4 2 time  / s9 6 4 0   ...    ...    ...    ... ..  [4] [total: 10]",
            "6": "6 0620/33/m/j/11 \u00a9 ucles 2011for examiner\u2019s use4  iron is extracted from its ore, hematite, in the blast furnace. slag molten ironairfirebrick liningwaste gases raw materials coke, ciron ore, fe 2o3 limestone, caco3   describe the reactions involved in this extraction. include in your description an equation for  a redox reaction and one for an acid  / base reaction.   ... ...   ... ...   ... ...   ... ...   ... .  [5] [total: 5]",
            "7": "7 0620/33/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use5  the diagram shows a simple cell. zinc electrode iron electrode bubbles of hydrogen dilute sulfuric acidvvoltmeter  (a)  write an equation for the overall reaction occurring in the cell.   ... ..  [2]  (b)  explain why all cell reactions are exothermic and redox.   ...    ...    ... ..  [3]  (c)  which electrode, zinc or iron, is the negative electrode? give a reason for your choice.   ...    ... ..  [2]  (d)  suggest two ways of increasing the voltage of this cell.   ...    ... ..  [2] [total: 9]",
            "8": "8 0620/33/m/j/11 \u00a9 ucles 2011for examiner\u2019s use6 (a)  methanol can be made from a mixture of carbon monoxide and hydrogen. co(g)  +  2h2(g)    ch3oh(g)   the forward reaction is exothermic.  (i)  explain why the concentration of methanol at equilibrium does not change.   . ...   . .  [2]  (ii)  suggest conditions, in terms of temperature and pressure, which would give a high  yield of methanol.   . ...   . .  [2]  (iii)  how would the conditions used in practice compare with those given in (ii)? give an  explanation of any differences.   . ...   . ...   . .  [2]  (b)  biodiesel is made from a vegetable oil by the following reaction. ++3ch3oh\u2192 3c17h35cooch3ch2oh choh ch2ohc17h35co2ch2 c17h35co2ch c17h35co2ch2 vegetable oil methanol biodiesel glycerol  (i)  what type of compound are vegetable oil and biodiesel?   . .  [1]  (ii)  what other useful product is made from vegetable oil by heating it with aqueous  sodium hydroxide?   . .  [1]  (iii)  suggest an explanation why making and using biodiesel has a smaller effect on  the percentage of carbon dioxide in the atmosphere than using petroleum-based diesel.   . ...   . ...   . .  [2]",
            "9": "9 0620/33/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  petroleum-based diesel is a mixture of hydrocarbons, such as octane and octene.  (i)  \u2018oct\u2019 means eight carbon atoms per molecule. draw a structural formula of an octene  molecule. [1]  (ii)  describe a test which would distinguish between octane and octene.  test   .  result with octane  ... result with octene  .  [3] [total: 14] 7  chlorine reacts with phosphorus to form phosphorus trichloride.  (a)  draw a diagram showing the arrangement of the valency  electrons in one molecule of  the covalent compound, phosphorus trichloride.  use x to represent an electron from a phosphorus atom. use o to represent an electron from a chlorine atom. [2]  (b)  phosphorus trichloride reacts with water to form two acids.  (i)  balance the equation for this reaction. pc l  3  +  ...h2o  \u2192  ...hc l  +  h3po3 [1]  (ii)  describe how you could show that phosphorus acid, h3po3, is a weaker acid than  hydrochloric acid.   . ...   . ...   . .  [3]",
            "10": "10 0620/33/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (iii)  two salts of phosphorus acid are its sodium salt, which is soluble in water, and its  calcium salt which is insoluble in water. suggest a method of preparation for each of these salts from aqueous phosphorus acid. specify any other reagent needed and brie\ufb02 y outline the method.  sodium salt    . ...   . ...   . .  [2]  calcium salt    . ...   . ...   . .  [2] [total: 10] 8  hydrocarbons are compounds which contain only carbon and hydrogen.  (a)  20  cm3 of a gaseous hydrocarbon was burned in 120  cm3 of oxygen, which is in excess.  after cooling, the volume of the gases remaining was 90  cm3. aqueous sodium hydroxide  was added to remove carbon dioxide, 30  cm3 of oxygen remained. all volumes were  measured at r.t.p..  (i)  explain why it is essential to use excess oxygen.   . ...   . .  [2]  (ii)  carbon dioxide is slightly soluble in water. why does it dissolve readily in the alkali,  sodium hydroxide?   . .  [1]  (iii)  complete the following.  volume of gaseous hydrocarbon = ...cm3  volume of oxygen used = .cm3  volume of carbon dioxide formed = .cm3 [2]  (iv)  use the above volume ratio to \ufb01 nd the mole ratio in the equation below and hence  \ufb01 nd the formula of the hydrocarbon.  cxhy(g)  +  o2(g)  \u2192  co2(g)  +  h2o(l) hydrocarbon formula =   [2]",
            "11": "11 0620/33/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (b)  alkanes are hydrocarbons and are generally unreactive. their reactions include  combustion, substitution and cracking.  (i)  chlorine reacts with butane in a substitution reaction. ch3 \u2014 ch2 \u2014 ch2 \u2014 ch3  +  c l 2  \u2192  ch3 \u2014 ch2 \u2014 ch2 \u2014 ch2 \u2014 cl  +  hc l   give the structural formula of another possible product of this reaction. [1]  (ii)  what is the essential condition for this reaction?   . .  [1]  (iii)  explain what is meant by cracking . give an example of a cracking reaction and  explain why the process is used.   . ...   . ...   . ...   . ...   . .  [4] [total: 13]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/33/m/j/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s11_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test may/june 2011  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 6 printed pages and 2 blank pages. [turn overib11 06_0620_51/4rp\u00a9 ucles 2011 *5258007914* for examiner\u2019s use total1 2",
            "2": "2 0620/51/m/j/11 \u00a9 ucles 2011for examiner\u2019s use1  you are going to investigate the reaction between two different solutions of potassium  manganate( vii), a and b, and an acidic solution of substance c.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out three experiments.  (a)  experiment 1   fill the burette with the solution a of potassium manganate( vii) to the 0.0  cm3 mark.  using a measuring cylinder, pour 25  cm3 of solution c into the conical \ufb02 ask.   add 1  cm3 of the solution a to the \ufb02 ask, with shaking. continue to add solution a to the  \ufb02 ask until the mixture just turns permanently pink. record the burette readings in the  table and complete the table.   pour away the contents of the conical \ufb02 ask and rinse the \ufb02 ask with distilled water. \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]   (b) experiment 2   empty the burette and rinse it \ufb01 rst with distilled water, and then with a little of solution b.  fill the burette with the solution b of potassium manganate( vii) solution to the 0.0  cm3  mark.   repeat experiment 1.   record the burette readings in the table and complete the table. \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]  (c) experiment 3   to about 2  cm3 of solution c in a test-tube, add one spatula measure of manganese( iv)  oxide. note any observations and test the gas given off.   ...    ...    ... ..  [3]",
            "3": "3 0620/51/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (d)  identify the gas given off in experiment 3.   ... ..  [1]  (e) (i)   what colour change was observed when potassium manganate( vii) solution was  added to the \ufb02 ask in experiment 1.  from ...  to  ... [1]  (ii)  why is an indicator not added to the \ufb02 ask?   . .  [1]  (f) (i)   in which experiment was the greatest volume of potassium manganate( vii) solution  used?   . .  [1]  (ii)  compare the volumes of potassium manganate( vii) used in experiments 1 and 2.   . .  [1]  (iii)  suggest an explanation for the difference in volumes.   . ...   . ...   . .  [2]  (g)  if experiment 2 was repeated using 12.5  cm3 of solution c, what volume of potassium  manganate( vii) solution would be used? explain your answer.   ...    ...    ... ..  [3]  (h)  give one advantage and one disadvantage of using a measuring cylinder for solution c.  advantage  ... ..  disadvantage  ..  [2] [total: 21]",
            "4": "4 0620/51/m/j/11 \u00a9 ucles 2011for examiner\u2019s use2  you are provided with two different liquids, m and n.   carry out the following tests on each liquid, recording all of your observations in the table.   conclusions must not be written in the table. tests observations (a) (i)  place a little of liquid m in a test-tube  and describe its smell and colour.  (ii)  place a little of liquid n in a test-tube  and describe its smell and colour. ..   [2] ..  [1] (b) (i)   using a teat pipette, transfer a few  drops of m to a dry watch glass.    touch the liquid with a lighted splint.  (ii)  repeat (b)(i)  using liquid n. ..   [2]  [1] (c) (i)   using a teat pipette, add about 1  cm3 of liquid m to a crystal of iodine  provided in a test-tube.   stopper and shake the test-tube.  (ii)  add about 1  cm3 of n to the other  crystal of iodine provided.    stopper and shake the test-tube.  (iii)  add a few drops of liquid t to the  mixture.   stopper and shake the test-tube. .  [2] .  [1]   [2] (d) (i)   to about 1  cm3 of liquid m, add a few  drops of dilute nitric acid and then  aqueous silver nitrate.  (ii)  repeat (d)(i)  using liquid n.  [1]   [2] (e)  to about 2  cm3 of liquid n, add about 2 cm3 of aqueous copper sulfate.   shake and leave to stand for \ufb01 ve  minutes. .   [2]",
            "5": "5 0620/51/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (f)  what type of substance is liquid m?   ...    ... ..  [2]  (g)  identify one ion present in liquid n.   ... ..  [1] [total: 19]",
            "6": "6 0620/51/m/j/11blank page \u00a9 ucles 2011",
            "7": "7 0620/51/m/j/11blank page \u00a9 ucles 2011",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/51/m/j/11notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2011"
        },
        "0620_s11_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test may/june 2011  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib11 06_0620_52/5rp\u00a9 ucles 2011 *3551390504* for examiner\u2019s use total1 2",
            "2": "2 0620/52/m/j/11 \u00a9 ucles 2011for examiner\u2019s use1  you are going to investigate the reaction between excess magnesium and two different dilute  acids, x and y.   read all the instructions below carefully before starting the experiments.  instructions   you are going to carry out two experiments.   (a)  experiment 1   set up the apparatus as shown in the diagram below. troughinverted 50  cm3 measuring cylinder  waterrubber connector bung conical flaskstand and clamp   remove the bung from the conical \ufb02 ask and move the measuring cylinder away from  the delivery tube without letting any water run out. twist one of the strips of magnesium  provided to break it into four pieces and place all of them into the conical \ufb02 ask.   using a different measuring cylinder, add 50  cm3 of aqueous acid x into the conical \ufb02 ask  and replace the bung \ufb01 rmly. place the measuring cylinder back over the delivery tube  and start the timer. in the table, record the volume of gas collected in the measuring cylinder every thirty seconds for three minutes. time  / s 0 30 60 90 120 150 180 volume of gas  / cm3 [3]   (b) experiment 2   repeat the whole of experiment 1 using 50  cm3 of aqueous acid y.   in the table, record the volume of gas collected in the measuring cylinder every thirty seconds for three minutes. time  / s 0 30 60 90 120 150 180 volume of gas  / cm3 [3]",
            "3": "3 0620/52/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  plot the results you have obtained for both experiments on the grid below. for each set  of results, draw a smooth line graph. indicate clearly which line represents experiment  1  and which line represents experiment 2. 60 5040302010 0 0 3 06 09 0 1 2 0 1 5 0 1 8 0 time  / svolume of gas  / cm3 [6]  (d) (i)   in which experiment was the speed of reaction fastest?   . .  [1]  (ii)  suggest why the speed was fastest in this experiment.   . ...   . .  [1]  (e)  why eventually will no more gas be produced?   ...    ... ..  [2]",
            "4": "4 0620/52/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (f)  from your graph , deduce the time required to collect 25  cm3 of gas in experiment 1.   show clearly on the graph  how you worked out your answer.   ... ..  [2]  (g)  why was the measuring cylinder moved away from the delivery tube while the acid  solution was added to the \ufb02 ask?   ...    ... ..  [2]  (h)  give one advantage and one disadvantage of using a measuring cylinder to add the  acids to the \ufb02 ask.  advantage  ... ..  disadvantage  ..  [2] [total: 22]",
            "5": "5 0620/52/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use2  you are provided with mixture z.   z consists of two solids, w and v. solid w is water-soluble and solid v is insoluble.   carry out the following tests on z, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on mixture z (a)  describe the appearance of the mixture.   [1] (b)  place a little of mixture z in a test-tube.   heat the mixture for about 1 minute.   after 1 minute, test the gas with damp ph  indicator paper. leave the test-tube to cool. ..  ..  [3]  add the rest of mixture z to about 10  cm3 of  distilled water in a boiling tube.  stopper the boiling tube and shake the  contents for about one minute. filter the contents of the test-tube. keep the residue and the \ufb01 ltrate for the  following tests. tests on the \ufb01 ltrate (c) (i)  to about 1  cm3 of the \ufb01 ltrate, add a few  drops of dilute nitric acid followed by  about 1  cm3 of silver nitrate solution  and shake the test-tube.  (ii)  to about 1  cm3 of the \ufb01 ltrate, add about  1 cm3 of aqueous sodium hydroxide.    gently heat the mixture. test the gas given off with damp ph indicator paper.  (iii)  to the third portion of the \ufb01 ltrate, add  about 1  cm3 of dilute hydrochloric acid  followed by about 1  cm3 of barium  chloride solution.  [2]  ..   [1]   [1]",
            "6": "6 0620/52/m/j/11 \u00a9 ucles 2011for examiner\u2019s usetests observations tests on the residue (d)  using a spatula, transfer some of the  residue from the \ufb01 lter paper to a test-tube.   using a teat pipette, add about 2  cm3 of  dilute hydrochloric acid to the residue.   test the gas given off.  add to the solution in the test-tube an equal  volume of distilled water. shake the contents and divide into two  portions. (e) (i)  to the \ufb01 rst portion of the solution, add  excess aqueous sodium hydroxide.  (ii)  to the second portion, add excess  aqueous ammonia solution. ..   [3]   [2]   [1]  (f)  what conclusions can you draw about solid w?   ...    ... ..  [2]  (g)  what conclusions can you draw about solid v?   ...    ... ..  [2] [total: 18]",
            "7": "7 0620/52/m/j/11blank page \u00a9 ucles 2011",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/52/m/j/11notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2011"
        },
        "0620_s11_qp_61.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical may/june 2011  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib11 06_0620_61/5rp\u00a9 ucles 2011 *4839073064* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/61/m/j/11 \u00a9 ucles 2011for examiner\u2019s use1  a student heated hydrated zinc sulfate crystals, znso4.7h2o, using the apparatus below to  obtain a sample of water. ice cubes in water  (a)  complete the box to identify the piece of apparatus labelled. [1]  (b)  use labelled arrows to indicate:  (i)  where the heat is applied,  (ii)  where the sample of water would collect. [2]  (c)  state the purpose of the ice cubes.   ... ..  [1]  (d)  describe a physical test for pure water.  test     result  .. .  [2] [total: 6]",
            "3": "3 0620/61/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use2  hydrochloric acid reacts with aqueous sodium thiosulfate to form a precipitate, which makes  the solution turn cloudy.   the formation of the precipitate can be used to show how fast the reaction proceeds, using the apparatus shown below. aqueous sodium thiosulfateeye 10  cm3 of hydrochloric acid conical flask printed sheet printed text   a student used this method to investigate the effect of changing the concentration of the sodium thiosulfate solution on the speed of the reaction.   the student used different concentrations of sodium thiosulfate solution.   all other variables were kept the same.  (a)  give two variables which were kept the same in the investigation.  1.  ...   2.  ... ..  [2]",
            "4": "4 0620/61/m/j/11 \u00a9 ucles 2011for examiner\u2019s use the results of the experiments are shown plotted on the grid below. 0.20 0.160.120.080.040.00 0.0 0.1 0.2 0.3speed of reaction /  arbitrary units concentration of sodium thiosulfate in mol  / dm3  (b)  draw a line of best \ufb01 t on the grid. [1]  (c)  suggest two reasons why not all of the points lie on the line of best \ufb01 t.  1.  ...   2.  ... ..  [2]  (d)  from your graph, deduce the speed of reaction when the concentration of sodium  thiosulfate is 0.075  mol  / dm3. show clearly on the graph  how you worked out your  answer.   ... ..  [2]  (e)  explain why the speed of reaction increases when the concentration of sodium thiosulfate is increased.   ...    ... ..  [2]  (f)  sketch on the grid the line you would expect if the experiments were repeated at a higher temperature. [1] [total: 10]",
            "5": "5 0620/61/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use3  the colours present in some fruit sweets can be separated using the apparatus below. the  colours are water-soluble dyes. solvent  (a)  name the process used to separate the colours.   ... ..  [1]  (b)  name the solvent used.   ... ..  [1]  the results obtained for the colours in two different sweets, c and d, are shown below. b sweet csweet d  (c)  what is the name for the line at position b?   ... ..  [1]  (d)  what conclusions can you draw about the colours present in sweets c and d?   ...    ...    ... ..  [3] [total: 6]",
            "6": "6 0620/61/m/j/11 \u00a9 ucles 2011for examiner\u2019s use4  a student investigated the reaction between two different solutions of deep purple potassium  manganate( vii), a and b, and an acidic solution of hydrogen peroxide.   three experiments were carried out.  experiment 1   a burette was \ufb01 lled with the solution a of potassium manganate( vii) up to the 0.0  cm3 mark.  using a measuring cylinder, 25  cm3 of colourless hydrogen peroxide solution was poured into  the conical \ufb02 ask.   the potassium manganate( vii) solution a was added slowly to the \ufb02 ask, and shaken to mix  thoroughly. addition of potassium manganate( vii) solution was continued until there was a  permanent pink colour in the contents of the \ufb02 ask.  (a)  use the burette diagram to record the volume in the table of results and complete the column. [2] 31 32 33 final reading  experiment 2   experiment 1 was repeated using the solution b of potassium manganate( vii) instead of  solution a.   (b)  use the burette diagrams to record the volumes in the table of results and complete the  table. [2] 18 19 20 initial reading34 35 36 final reading experiment 1 experiment 2 \ufb01 nal reading  / cm3 initial reading  / cm3 difference  / cm3",
            "7": "7 0620/61/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use experiment 3   to a little of the hydrogen peroxide solution in a test-tube, manganese( iv) oxide was added.   rapid effervescence was observed and a glowing splint relit.  (c)  identify the gas given off in experiment 3.   ... ..  [1]  (d) (i)   what colour change was observed when potassium manganate( vii) solution was  added to the \ufb02 ask?  from .  to . [1]  (ii)  why was an indicator not added to the \ufb02 ask?   . .  [1]  (e) (i)   in which experiment was the greatest volume of potassium manganate( vii) solution  used?   . .  [1]  (ii)  compare the volumes of potassium manganate( vii) used in experiments 1 and 2.   . .  [1]  (iii)  suggest an explanation for the difference in volumes.   . ...   . ...   . .  [2]  (f)  if experiment 2 was repeated using 12.5  cm3 of the hydrogen peroxide solution, what  volume of potassium manganate( vii) solution would be needed to react completely?  explain your answer.   ...    ... ..  [3]  (g)  give one advantage and one disadvantage of using a measuring cylinder for the  hydrogen peroxide solution.  advantage  ... ..  disadvantage  ..  [2] [total: 16]",
            "8": "8 0620/61/m/j/11 \u00a9 ucles 2011for examiner\u2019s use5  two different liquids, m and n, were analysed. n was aqueous potassium iodide.  the tests on the liquids and some of the observations are in the following table.  complete the observations in the table. tests observations (a) (i)  appearance of liquid m.  (ii)  appearance of liquid n. colourless liquid with an antiseptic smell   [2] (b) (i)  a few drops of m were transferred  to a dry watch glass. the liquid was  touched with a lighted splint.  (ii)  test (b)(i)  was repeated using liquid n. (c)  a little of liquid m was added to a crystal  of iodine in a test-tube. the test-tube was shaken. (d)  to a little of liquid n, a few drops of dilute  nitric acid was added, followed by silver nitrate solution. burns with a yellow \ufb02 ame   [1]  orange-brown solution ... [2]  (e)  what type of substance is liquid m?   ...    ... ..  [2] [total: 7]",
            "9": "9 0620/61/m/j/11blank page \u00a9 ucles 2011 [turn over",
            "10": "10 0620/61/m/j/11 \u00a9 ucles 2011for examiner\u2019s use6  the reaction between aqueous barium chloride and aqueous sodium sulfate produces a  white precipitate.   six experiments were carried out to \ufb01 nd the mass of precipitate produced using solution p  and solution q.   solution p was aqueous barium chloride.   solution q was aqueous sodium sulfate.   both solutions were of the same concentration.   5 cm3 of solution p was put into each of six test-tubes. increasing volumes of solution q were  added to each test-tube. the mixtures were \ufb01 ltered to obtain the precipitates, which were  washed, dried and then weighed in a suitable container.  (a)  draw a labelled diagram to show how the mixture was \ufb01 ltered. [2]   the results are shown in the table below.  (b)  complete the table. volume of p / cm3volume of q / cm3mass of  container  / gmass of container  and precipitate  / gmass of  precipitate  / g 5 1 4.50 4.95 5 2 4.50 5.455 3 4.50 5.905 4 4.50 6.405 5 4.50 6.855 6 4.50 6.85 [2]",
            "11": "11 0620/61/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  plot the points on the grid below. join the points with two intersecting straight lines. 2.5 2.01.51.00.50.0 0246 135mass of precipitate  / g volume of q / cm3 [3]  (d)  what is the minimum volume of q required to completely react with 5  cm3 of p?   ... ..  [1] [total: 8]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/61/m/j/11 \u00a9 ucles 2011for examiner\u2019s use7  the label shows some information on a bottle of liquid sink and drain cleaner. contains: sodium hydroxide, sodiumhypochloritecontact with acids liberateschlorinerinse container with waterbefore throwing out  (a)  give a chemical test for the presence of sodium hydroxide.  test     result  .. .  [2]  (b)  suggest why it could be dangerous to pour \ufb01 zzy drinks into a sink containing this liquid  cleaner.   ...    ... ..  [2]  (c)  why should the container be rinsed with water before throwing out?   ... ..  [1]  (d)  give a chemical test for chlorine.  test     result  .. .  [2] [total: 7]"
        },
        "0620_s11_qp_62.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical may/june 2011  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib11 06_0620_62/4rp\u00a9 ucles 2011 *9988663665* for examiner\u2019s use 3 4 5 total612",
            "2": "2 0620/62/m/j/11blank page \u00a9 ucles 2011",
            "3": "3 0620/62/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use1  a student separated an aqueous solution of sodium chloride.   she measured out 70  cm3 of the solution and then obtained pure water from the solution.  (a)  which of these pieces of apparatus is most suitable to measure 70  cm3 of the solution?  tick one box. [1]  (b) (i)   complete the empty boxes to name the pieces of apparatus below. heat heat ab c [3]  (ii)  which method of separation, a, b or c, would be most suitable to obtain pure water  from the solution?  apparatus  [1]  (c)  describe how crystals of sodium chloride could be quickly obtained from the solution.   ...    ...    ... ..  [2] [total: 7]",
            "4": "4 0620/62/m/j/11 \u00a9 ucles 2011for examiner\u2019s use2  a student investigated the temperature changes when increasing amounts of zinc powder  were added to 25  cm3 of aqueous copper( ii) sulfate in a beaker. the equation for the reaction  is shown below. zn(s)  +  cuso4(aq)  \u2192  cu(s)  +  znso4(aq)   five experiments were carried out. the initial temperature in each experiment was 22  \u00b0c.   the thermometer diagrams in the table show the highest temperature reached after each  addition of zinc.  (a)  use the thermometer diagrams to record the highest temperatures and complete the  table. mass of zinc added  / g 0.30 0.600.901.201.501 2345thermometer diagramexperimenthighest temperature  / \u00b0ctemperature rise  / \u00b0c 30 25 20 30 25 20 40 35 30 40 35 30 45 40 35 [4]",
            "5": "5 0620/62/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (b)  plot the results on the grid below and draw a straight line graph. 0.00 0.30 0.60 0.90 1.20 1.50 1.80temperature rise  / \u00b0c mass of zinc added  / g25 201510 50 [3]  (c)  which result appears to be inaccurate?   ... ..  [1]  (d)  use your graph to \ufb01 nd the temperature rise produced by 1.80  g of zinc. show clearly on  the grid  how you obtained your answer.   ... ..  [3]  (e)  state two observations, other than a rise in temperature, which would be made when  zinc reacted with the aqueous copper( ii) sulfate.  1.  ...   2.  ... ..  [2] [total: 13]",
            "6": "6 0620/62/m/j/11 \u00a9 ucles 2011for examiner\u2019s use3  electricity was passed through a solution of concentrated hydrochloric acid using the  apparatus shown. electrode electrode concentratedhydrochloric acid  (a)  give two expected observations.  1.  ...   2.  ... ..  [2]  (b)  suggest a suitable material for the electrodes.   ... ..  [1]  (c)  a lighted splint placed in a test-tube of the gas collected at the negative electrode gave  a pop sound.  the identity of the gas was  .  [1] (d)  state two safety precautions that must be followed when carrying out this experiment.  1.  ...   2.  ... ..  [2] [total: 6]",
            "7": "7 0620/62/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use4  a student investigated the speed of reaction between excess magnesium and two different  dilute acids, x and y.  two experiments were carried out.  experiment 1   the apparatus was set up as shown in the diagram. water trough50  cm3 of acid solutionbungrubber connector inverted100  cm3 measuringcylinder   using a measuring cylinder, 50  cm3 of acid x was poured into the conical \ufb02 ask.   0.5  g of magnesium ribbon was added to the conical \ufb02 ask and the bung replaced.   the timer was started and the volume of gas collected in the measuring cylinder was measured  every thirty seconds for three minutes.",
            "8": "8 0620/62/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (a)   use the measuring cylinder diagrams to record the volumes of gas collected in the table  of results. time  / smeasuring cylinder diagramtotal volume of gas collected  / cm3 0 3060 90 1201500 5 10 10 15 20 20 25 30 25 30 35 30 35 40 40 45 50 18045 50 55 [3]",
            "9": "9 0620/62/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use experiment 2   experiment 1 was repeated using 50  cm3 of acid y.  (b)  use the measuring cylinder diagrams to record the volumes of gas collected in the table  of results. time  / smeasuring cylinder diagramtotal volume of gas collected  / cm3 0 3060 90 1201500 5 10 0 5 10 5 10 15 10 15 20 10 15 20 15 20 25 18015 20 25 [3]",
            "10": "10 0620/62/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (c)  plot the results for both experiments on the grid below. for each set of results, draw a  smooth line graph. indicate clearly which line represents experiment 1 and which line represents experiment 2. 0 30 60 90 120 150 180volume of gas  / cm3 time  / s60 5040302010 0 [6]  (d) (i)   in which experiment was the speed of reaction fastest?   . .  [1]  (ii)  suggest why the speed was fastest in this experiment.   . ...   . .  [1]  (e)   why, eventually, will no more gas be produced?   ...    ... ..  [2]",
            "11": "11 0620/62/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (f)  from your graph, deduce the time required to collect 25  cm3 of gas in experiment 1.    show clearly on the graph  how you worked out your answer.   ... ..  [2]  (g)  give one advantage and one disadvantage of using a measuring cylinder to add the  acids to the \ufb02 ask.  advantage  ... ..  disadvantage  ..  [2] [total: 20]",
            "12": "12 0620/62/m/j/11 \u00a9 ucles 2011for examiner\u2019s use5  a mixture, z, of two different solids was analysed. z consisted of solid w, which was water-soluble ammonium chloride, and solid v, which was insoluble.   the tests on the solids, and some of the observations, are in the following table.   complete the observations in the table. tests observations tests on mixture z (a)  appearance of the mixture. white solid mixture z was added to distilled water in a  boiling tube. the boiling tube and contents were shaken and then \ufb01 ltered. tests on the \ufb01 ltrate the \ufb01 ltrate was divided into three test-tubes. (b) (i)  to the \ufb01 rst test-tube of the \ufb01 ltrate, a few  drops of dilute nitric acid was added followed by silver nitrate solution.  (ii)  to the second test-tube of the \ufb01 ltrate,  aqueous sodium hydroxide was added.   the mixture was heated. the gas given  off was tested with damp ph indicator paper.  (iii)  to the third test-tube of the \ufb01 ltrate,  dilute hydrochloric acid was added followed by barium chloride solution.  [2]  ...  ... [2]  ... [1]",
            "13": "13 0620/62/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s usetests observations tests on the residue (c)  by using a spatula, some of the residue  was transferred from the \ufb01 lter paper into  a test-tube. dilute hydrochloric acid was added to the residue.   the gas given off was tested.  the solution in the test-tube was divided into  two portions.rapid effervescence limewater turned milky (d) (i)  to the \ufb01 rst portion of the solution,  excess aqueous sodium hydroxide was added.  (ii)  to the second portion of the solution,  excess aqueous ammonia solution was added.white precipitate formed, insoluble in excess no precipitate formed  (e)  identify the gas given off in (c).   ... ..  [1]  (f)  what conclusions can you draw about solid v?   ...    ...    ... ..  [2] [total: 8]",
            "14": "14 0620/62/m/j/11 \u00a9 ucles 2011for examiner\u2019s use6  petrol is a liquid fuel obtained from petroleum (crude oil).   bioethanol is a liquid fuel made by the fermentation of carbohydrates obtained from plants  such as sugar cane.   using the apparatus below, plan an experiment to investigate which of these two fuels  produces more energy.   you may use the space below to draw a diagram to help you answer the question. retort standspirit burner balancethermometer copper can water   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [6] [total: 6]",
            "15": "15 0620/62/m/j/11blank page \u00a9 ucles 2011",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/62/m/j/11blank page \u00a9 ucles 2011"
        },
        "0620_s11_qp_63.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical may/june 2011  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib11 06_0620_63/fp\u00a9 ucles 2011 *4894356121* for examiner\u2019s use 3 4 5 total612",
            "2": "2 0620/63/m/j/11blank page \u00a9 ucles 2011",
            "3": "3 0620/63/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use1  a student separated an aqueous solution of sodium chloride.   she measured out 70  cm3 of the solution and then obtained pure water from the solution.  (a)  which of these pieces of apparatus is most suitable to measure 70  cm3 of the solution?  tick one box. [1]  (b) (i)   complete the empty boxes to name the pieces of apparatus below. heat heat ab c [3]  (ii)  which method of separation, a, b or c, would be most suitable to obtain pure water  from the solution?  apparatus  [1]  (c)  describe how crystals of sodium chloride could be quickly obtained from the solution.   ...    ...    ... ..  [2] [total: 7]",
            "4": "4 0620/63/m/j/11 \u00a9 ucles 2011for examiner\u2019s use2  a student investigated the temperature changes when increasing amounts of zinc powder  were added to 25  cm3 of aqueous copper( ii) sulfate in a beaker. the equation for the reaction  is shown below. zn(s)  +  cuso4(aq)  \u2192  cu(s)  +  znso4(aq)   five experiments were carried out. the initial temperature in each experiment was 22  \u00b0c.   the thermometer diagrams in the table show the highest temperature reached after each  addition of zinc.  (a)  use the thermometer diagrams to record the highest temperatures and complete the  table. mass of zinc added  / g 0.30 0.600.901.201.501 2345thermometer diagramexperimenthighest temperature  / \u00b0ctemperature rise  / \u00b0c 30 25 20 30 25 20 40 35 30 40 35 30 45 40 35 [4]",
            "5": "5 0620/63/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (b)  plot the results on the grid below and draw a straight line graph. 0.00 0.30 0.60 0.90 1.20 1.50 1.80temperature rise  / \u00b0c mass of zinc added  / g25 201510 50 [3]  (c)  which result appears to be inaccurate?   ... ..  [1]  (d)  use your graph to \ufb01 nd the temperature rise produced by 1.80  g of zinc. show clearly on  the grid  how you obtained your answer.   ... ..  [3]  (e)  state two observations, other than a rise in temperature, which would be made when  zinc reacted with the aqueous copper( ii) sulfate.  1.  ...   2.  ... ..  [2] [total: 13]",
            "6": "6 0620/63/m/j/11 \u00a9 ucles 2011for examiner\u2019s use3  electricity was passed through a solution of concentrated hydrochloric acid using the  apparatus shown. electrode electrode concentratedhydrochloric acid  (a)  give two expected observations.  1.  ...   2.  ... ..  [2]  (b)  suggest a suitable material for the electrodes.   ... ..  [1]  (c)  a lighted splint placed in a test-tube of the gas collected at the negative electrode gave  a pop sound.  the identity of the gas was  .  [1] (d)  state two safety precautions that must be followed when carrying out this experiment.  1.  ...   2.  ... ..  [2] [total: 6]",
            "7": "7 0620/63/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use4  a student investigated the speed of reaction between excess magnesium and two different  dilute acids, x and y.  two experiments were carried out.  experiment 1   the apparatus was set up as shown in the diagram. water trough50  cm3 of acid solutionbungrubber connector inverted100  cm3 measuringcylinder   using a measuring cylinder, 50  cm3 of acid x was poured into the conical \ufb02 ask.   0.5  g of magnesium ribbon was added to the conical \ufb02 ask and the bung replaced.   the timer was started and the volume of gas collected in the measuring cylinder was measured  every thirty seconds for three minutes.",
            "8": "8 0620/63/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (a)   use the measuring cylinder diagrams to record the volumes of gas collected in the table  of results. time  / smeasuring cylinder diagramtotal volume of gas collected  / cm3 0 3060 90 1201500 5 10 10 15 20 20 25 30 25 30 35 30 35 40 40 45 50 18045 50 55 [3]",
            "9": "9 0620/63/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use experiment 2   experiment 1 was repeated using 50  cm3 of acid y.  (b)  use the measuring cylinder diagrams to record the volumes of gas collected in the table  of results. time  / smeasuring cylinder diagramtotal volume of gas collected  / cm3 0 3060 90 1201500 5 10 0 5 10 5 10 15 10 15 20 10 15 20 15 20 25 18015 20 25 [3]",
            "10": "10 0620/63/m/j/11 \u00a9 ucles 2011for examiner\u2019s use (c)  plot the results for both experiments on the grid below. for each set of results, draw a  smooth line graph. indicate clearly which line represents experiment 1 and which line represents experiment 2. 0 30 60 90 120 150 180volume of gas  / cm3 time  / s60 5040302010 0 [6]  (d) (i)   in which experiment was the speed of reaction fastest?   . .  [1]  (ii)  suggest why the speed was fastest in this experiment.   . ...   . .  [1]  (e)   why, eventually, will no more gas be produced?   ...    ... ..  [2]",
            "11": "11 0620/63/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (f)  from your graph, deduce the time required to collect 25  cm3 of gas in experiment 1.    show clearly on the graph  how you worked out your answer.   ... ..  [2]  (g)  give one advantage and one disadvantage of using a measuring cylinder to add the  acids to the \ufb02 ask.  advantage  ... ..  disadvantage  ..  [2] [total: 20]",
            "12": "12 0620/63/m/j/11 \u00a9 ucles 2011for examiner\u2019s use5  a mixture, z, of two different solids was analysed. z consisted of solid w, which was water-soluble ammonium chloride, and solid v, which was insoluble.   the tests on the solids, and some of the observations, are in the following table.   complete the observations in the table. tests observations tests on mixture z (a)  appearance of the mixture. white solid mixture z was added to distilled water in a  boiling tube. the boiling tube and contents were shaken and then \ufb01 ltered. tests on the \ufb01 ltrate the \ufb01 ltrate was divided into three test-tubes. (b) (i)  to the \ufb01 rst test-tube of the \ufb01 ltrate, a few  drops of dilute nitric acid was added followed by silver nitrate solution.  (ii)  to the second test-tube of the \ufb01 ltrate,  aqueous sodium hydroxide was added.   the mixture was heated. the gas given  off was tested with damp ph indicator paper.  (iii)  to the third test-tube of the \ufb01 ltrate,  dilute hydrochloric acid was added followed by barium chloride solution.  [2]  ...  ... [2]  ... [1]",
            "13": "13 0620/63/m/j/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s usetests observations tests on the residue (c)  by using a spatula, some of the residue  was transferred from the \ufb01 lter paper into  a test-tube. dilute hydrochloric acid was added to the residue.   the gas given off was tested.  the solution in the test-tube was divided into  two portions.rapid effervescence limewater turned milky (d) (i)  to the \ufb01 rst portion of the solution,  excess aqueous sodium hydroxide was added.  (ii)  to the second portion of the solution,  excess aqueous ammonia solution was added.white precipitate formed, insoluble in excess no precipitate formed  (e)  identify the gas given off in (c).   ... ..  [1]  (f)  what conclusions can you draw about solid v?   ...    ...    ... ..  [2] [total: 8]",
            "14": "14 0620/63/m/j/11 \u00a9 ucles 2011for examiner\u2019s use6  petrol is a liquid fuel obtained from petroleum (crude oil).   bioethanol is a liquid fuel made by the fermentation of carbohydrates obtained from plants  such as sugar cane.   using the apparatus below, plan an experiment to investigate which of these two fuels  produces more energy.   you may use the space below to draw a diagram to help you answer the question. retort standspirit burner balancethermometer copper can water   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [6] [total: 6]",
            "15": "15 0620/63/m/j/11blank page \u00a9 ucles 2011",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/63/m/j/11blank page \u00a9 ucles 2011"
        },
        "0620_w11_qp_11.pdf": {
            "1": "    this document consists of 16 printed pages.  ib11 11_0620_11/2rp  \u00a9 ucles 2011  [turn over       *4524729851* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  october/november 2011       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2011 0620/11/o/n/11  1 in which substance are the particles close together and slowly moving past each other?  a air  b ice  c steam  d water      2 a student was provided with only a thermometer, a stopwatch and a beaker.    what could the student measure?  a 10.5  g solid and 24.8  cm3 liquid  b 10.5  g solid and 25  \u00b0c  c 24.8  cm3 liquid and 45 seconds  d 25  \u00b0c and 45 seconds      3 mixture 1 contains sand and water.    mixture 2 contains salt and water.    which method of separation could be used to obtain each of the required products from each  mixture?    mixture 1 mixture 2    to obtain sand to obtain water to obtain salt to obtain water  a crystallisation distillation filtration filtration  b crystallisation filtration filtration distillation  c filtration distillation crystallisation filtration  d filtration filtration crystallisation distillation    ",
            "3": "3  \u00a9 ucles 2011 0620/11/o/n/11 [turn over  4 the diagram shows the electronic structures of atoms p and q.    key  = electron ee eeee e e eeeee ee epq= nucleus     p and q combine to form a molecule.    what is the formula of this molecule?  a pq 4 b pq c p 2q d p 4q      5 two isotopes of helium are he3 2and he.4 2     which two diagrams show the arrangement of particles in these two isotopes?    p n2 1ee ep n22ee p ne e ea np 21ee ep n2 2ee e eb p n21ee p n22ee c p3 p4ee ee dkey = electron = proton= neutron= nucleushe 3 242he  ",
            "4": "4  \u00a9 ucles 2011 0620/11/o/n/11  6 two elements, represented by  and , form a compound.    which diagram shows molecules of the compound?    abc d       7 the table describes the structures of four particles.    particle number of  protons number of  neutrons number of  electrons  o 8 8 8  o2\u2013 8 8 x  na 11 y 11  na+ 11 12 z    what are the correct values of x, y and z?     x y z  a 9 11 10  b 9 11 11  c 10 12 10  d 10 12 11      8 the relative formula mass, mr, of copper( ii) sulfate, cuso 4, is 160.    which mass of sulfur is present in 160  g of copper( ii) sulfate?  a 16  g b 32  g c 64  g d 128  g     ",
            "5": "5  \u00a9 ucles 2011 0620/11/o/n/11 [turn over  9 the diagram shows a section of an overhead power cable.    aluminiumsteel glazed porcelain     which statement explains why a particular substance is used?  a aluminium has a low density and is a good conductor of electricity.  b porcelain is a good conductor of electricity.  c steel can rust in damp air.  d steel is more dense than aluminium.      10 metals could be extracted from their molten chlorides using electrolysis.    which substances are formed at each electrode?     anode cathode  a chlorine hydrogen  b chlorine metal  c hydrogen metal  d metal chlorine      11 concentrated aqueous potassium bromide solution is electrolysed using inert electrodes.    the ions present in the solution are k+, br  \u2013, h+ and oh\u2013.    to which electrodes are the ions attracted during this electrolysis?     attracted to anode attracted to cathode  a br \u2013 and k+ h+ and oh\u2013  b br \u2013 and oh\u2013 h+ and k+  c h+ and k+ br  \u2013 and oh\u2013  d h+ and oh\u2013 br  \u2013 and k+    ",
            "6": "6  \u00a9 ucles 2011 0620/11/o/n/11  12 which fuel needs oxygen in order to produce heat energy and which type of reaction produces  the energy?     fuel type of reaction  a a radioactive isotope endothermic  b a radioactive isotope exothermic  c hydrogen endothermic  d hydrogen exothermic     13 some reactions are listed.    methane + oxygen \u2192 carbon dioxide + water  sodium + water \u2192 sodium hydroxide + hydrogen  magnesium + hydrochloric acid \u2192 magnesium chloride + hydrogen    which word correctly describes all of these reactions?  a combustion  b endothermic  c exothermic  d neutralisation     14 the sign   is used in some equations to show that a reaction is reversible.    two incomplete equations are given.     reactants products  p coc l 2 + 2h 2o coc l 2.2h 2o   q c + o 2 co 2    for which of these reactions can a  sign be correctly used to complete the equation?     p q  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "7": "7  \u00a9 ucles 2011 0620/11/o/n/11 [turn over  15 an experiment to determine the rate of a chemical reaction could be carried out using the  apparatus shown.    reaction mixture     which reaction is being studied?  a c l 2 + 2kbr \u2192 2kc l + br 2  b mg + h 2so 4 \u2192 mgso 4 + h 2  c nac l + agno 3 \u2192 nano 3 + agc l  d naoh + hc l \u2192 nac l + h 2o      16 copper( ii) carbonate reacts with dilute sulfuric acid.    cuco 3(s) + h 2so 4(aq) \u2192 cuso 4(aq) + co 2(g) + h 2o(l)    the speed of the reaction can be changed by varying the conditions.    which conditions would always increase the speed of this chemical reaction?    1 increase the concentration of the reactants.  2 increase the size of the pieces of copper( ii) carbonate.  3 increase the temperature. 4 increase the volume of sulfuric acid.    a 1, 3 and 4 b 1 and 3 only c 2 and 3 d 3 and 4 only     17 which type of reaction always forms a salt and water?  a exothermic  b neutralisation  c oxidation  d polymerisation    ",
            "8": "8  \u00a9 ucles 2011 0620/11/o/n/11  18 which property is not characteristic of a base?  a it reacts with a carbonate to form carbon dioxide.  b it reacts with an acid to form a salt.  c it reacts with an ammonium salt to form ammonia.  d it turns universal indicator paper blue.      19 an alloy contains copper and zinc.    some of the zinc has become oxidised to zinc oxide.    what is the result of adding an excess of dilute sulfuric acid to the alloy?  a a blue solution and a white solid remains.  b a colourless solution and a pink  / brown solid remains.  c the alloy dissolves completely to give a blue solution.  d the alloy dissolves completely to give a colourless solution.      20 the results of three tests on a solution of compound x are shown.    test result  aqueous sodium  hydroxide added white precipitate formed, soluble in excess  aqueous ammonia added white precipitate formed,  soluble in excess  dilute hydrochloric  acid added bubbles of gas    what is compound x?  a aluminium carbonate  b aluminium chloride  c zinc carbonate  d zinc chloride     ",
            "9": "9  \u00a9 ucles 2011 0620/11/o/n/11 [turn over  21 statement 1:  helium is a reactive gas.    statement 2:  helium can be used to fill balloons.    which is correct?    a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     22 an element has the following properties.    \u25cf it forms coloured compounds.  \u25cf it acts as a catalyst.  \u25cf it melts at 1539  \u00b0c.    in which part of the periodic table is the element found?  a group i  b group iv  c group vii  d transition elements     23 the table shows some properties of two elements in group vii of the periodic table.    element state at 20  \u00b0c density  / g per cm3 melting point  / \u00b0c  chlorine gas 0.0032 \u2013101   bromine liquid 3.1 000  \u20137     which properties is fluorine likely to have?     state at 20  \u00b0c density  / g per cm3 melting point  / \u00b0c  a gas 0.0017 \u2013220  b gas 0.17 00  \u2013188  c liquid 0.0017 \u2013220  d liquid 0.17 00  \u2013188     ",
            "10": "10  \u00a9 ucles 2011 0620/11/o/n/11  24 when sodium reacts with water, a solution and a gas are produced.    watersodium     the solution is tested with litmus paper and the gas is tested with a splint.    what happens to the litmus paper and to the splint?     litmus paper splint  a blue to red glowing splint relights  b blue to red lighted splint \u2018pops\u2019  c red to blue glowing splint relights  d red to blue lighted splint \u2018pops\u2019     25 which statements are correct?    1 metals are often used in the form of alloys.  2 stainless steel is an alloy of iron. 3 alloys always contain more than two metals.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     26 which statement is true about all metals?  a they are attracted to a magnet.  b they are weak and brittle.  c they may be used to form alloys.  d they react with water.     27 a chemical engineer plans to produce hydrochloric acid.    which metal is best for the reaction container?  a copper  b iron  c magnesium  d zinc     ",
            "11": "11  \u00a9 ucles 2011 0620/11/o/n/11 [turn over  28 alloy x is strong and has a low density.    alloy y is heavy but is resistant to corrosion.    which could be uses of x and y?     bridge  supports aircraft overhead  cables  a x x y  b x y y  c y x x  d y y x     29 a metal is extracted from hematite, its oxide ore.    what is the metal and how is the oxide reduced?     metal method of reduction  a al electrolysis  b al heating with carbon  c fe electrolysis  d fe heating with carbon      30 a liquid turns white anhydrous copper sulfate blue and has a boiling point of 103 \u00b0c.     which could be the identity of the liquid?  a alcohol  b petrol  c salt solution  d pure water     ",
            "12": "12  \u00a9 ucles 2011 0620/11/o/n/11  31 dry air is passed over hot copper until all the oxygen has reacted.    heatcopper dry air     the volume of gas at the end of the reaction is 120  cm3.    what is the starting volume of dry air?  a 132  cm3 b 150  cm3 c 180  cm3 d 600  cm3      32 in which row is the air pollutant not correctly matched with its source?     air pollutant source  a carbon monoxide incomplete combustion of fuels  b lead compounds burning petrol in cars  c nitrogen oxides decomposing vegetation  d sulfur dioxide burning coal and other fossil fuels    33 iron is a metal that rusts in the presence of oxygen and water.    mild steel is used for \u2026\u20261\u2026\u2026 and is prevented from rusting by \u2026\u20262\u2026\u2026 .    stainless steel is prevented from rusting by \u2026\u20263\u2026\u2026 it with another metal.    which words correctly complete gaps 1, 2 and 3?     1 2 3  a car bodies greasing covering  b car bodies painting mixing  c cutlery greasing covering  d cutlery painting mixing    ",
            "13": "13  \u00a9 ucles 2011 0620/11/o/n/11 [turn over  34 which combination of chemical compounds could be used to produce the fertiliser shown?    supergrown     p     k 21 16 8::     a nh 4no 3, ca 3(po 4)2  b nh 4no 3, co(nh 2)2  c nh 4no 3, k2so 4, (nh 4)2so 4  d (nh 4)3po 4, kc l      35 which pollutant gas is produced by the decomposition of vegetation?  a carbon monoxide  b methane  c nitrogen oxide  d sulfur dioxide    36 the diagram represents the molecule of an organic compound.    key = carbon = oxygen= hydrogen     what is the name of the compound?  a ethane  b ethanoic acid   c ethanol  d ethene     ",
            "14": "14  \u00a9 ucles 2011 0620/11/o/n/11  37 petroleum is a very important raw material that is separated into more useful products.    which terms describe petroleum and the method used to separate it?     petroleum is a method used to  separate petroleum  a compound cracking  b compound fractional distillation  c mixture cracking  d mixture fractional distillation      38 which pair of compounds are members of the same homologous series?    a cch hhh hc hh c hhhb hc hh ch hh hc hh ch ch hhh d hc hh ch ohh o ohhc hh cc cch hhh c hh ch nh      ",
            "15": "15  \u00a9 ucles 2011 0620/11/o/n/11  39 the table shows the composition of four different types of petroleum (crude oil).    fraction arabian heavy  / % arabian light  / % iranian heavy  / % north sea  / %  gasoline 18 21 21 23  kerosene 11.5 13 13 15  diesel 18 20 20 24  fuel oil 52.5 46 46 38    which type of petroleum is best for the motor vehicle industry?  a arabian heavy  b arabian light  c iranian heavy  d north sea     40 when glucose is fermented, ethanol is formed together with  a carbon dioxide.  b ethene.  c methane.  d oxygen.    ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2011 0620/11/o/n/11   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w11_qp_12.pdf": {
            "1": "    this document consists of 16 printed pages.  ib11 11_0620_12/2rp  \u00a9 ucles 2011  [turn over       *6081136031* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  october/november 2011       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2011 0620/12/o/n/11  1 in which substance are the particles close together and slowly moving past each other?  a air  b ice  c steam  d water      2 the diagram shows the electronic structures of atoms p and q.    key  = electron ee eeee e e eeeee ee epq= nucleus     p and q combine to form a molecule.    what is the formula of this molecule?  a pq 4 b pq c p 2q d p 4q     3 a student was provided with only a thermometer, a stopwatch and a beaker.    what could the student measure?  a 10.5  g solid and 24.8  cm3 liquid  b 10.5  g solid and 25  \u00b0c  c 24.8  cm3 liquid and 45 seconds  d 25  \u00b0c and 45 seconds    ",
            "3": "3  \u00a9 ucles 2011 0620/12/o/n/11 [turn over  4 two isotopes of helium are he3 2and he.4 2     which two diagrams show the arrangement of particles in these two isotopes?    p n2 1ee ep n22ee p ne e ea np 21ee ep n2 2ee e eb p n21ee p n22ee c p3 p4ee ee dkey = electron = proton= neutron= nucleushe 3 242he       5 mixture 1 contains sand and water.    mixture 2 contains salt and water.    which method of separation could be used to obtain each of the required products from each  mixture?    mixture 1 mixture 2    to obtain sand to obtain water to obtain salt to obtain water  a crystallisation distillation filtration filtration  b crystallisation filtration filtration distillation  c filtration distillation crystallisation filtration  d filtration filtration crystallisation distillation    ",
            "4": "4  \u00a9 ucles 2011 0620/12/o/n/11  6 the relative formula mass, mr, of copper( ii) sulfate, cuso 4, is 160.    which mass of sulfur is present in 160  g of copper( ii) sulfate?  a 16  g b 32  g c 64  g d 128  g     7 two elements, represented by  and , form a compound.    which diagram shows molecules of the compound?    abc d     8 the table describes the structures of four particles.    particle number of  protons number of  neutrons number of  electrons  o 8 8 8  o2\u2013 8 8 x  na 11 y 11  na+ 11 12 z    what are the correct values of x, y and z?     x y z  a 9 11 10  b 9 11 11  c 10 12 10  d 10 12 11    ",
            "5": "5  \u00a9 ucles 2011 0620/12/o/n/11 [turn over  9 metals could be extracted from their molten chlorides using electrolysis.    which substances are formed at each electrode?     anode cathode  a chlorine hydrogen  b chlorine metal  c hydrogen metal  d metal chlorine     10 the diagram shows a section of an overhead power cable.    aluminiumsteel glazed porcelain     which statement explains why a particular substance is used?  a aluminium has a low density and is a good conductor of electricity.  b porcelain is a good conductor of electricity.  c steel can rust in damp air.  d steel is more dense than aluminium.      11 concentrated aqueous potassium bromide solution is electrolysed using inert electrodes.    the ions present in the solution are k+, br  \u2013, h+ and oh\u2013.    to which electrodes are the ions attracted during this electrolysis?     attracted to anode attracted to cathode  a br \u2013 and k+ h+ and oh\u2013  b br \u2013 and oh\u2013 h+ and k+  c h+ and k+ br  \u2013 and oh\u2013  d h+ and oh\u2013 br  \u2013 and k+    ",
            "6": "6  \u00a9 ucles 2011 0620/12/o/n/11  12 the sign  is used in some equations to show that a reaction is reversible.    two incomplete equations are given.     reactants products  p coc l 2 + 2h 2o coc l 2.2h 2o   q c + o 2 co 2    for which of these reactions can a  sign be correctly used to complete the equation?     p q  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     13 which fuel needs oxygen in order to produce heat energy and which type of reaction produces  the energy?     fuel type of reaction  a a radioactive isotope endothermic  b a radioactive isotope exothermic  c hydrogen endothermic  d hydrogen exothermic    14 some reactions are listed.    methane + oxygen \u2192 carbon dioxide + water  sodium + water \u2192 sodium hydroxide + hydrogen  magnesium + hydrochloric acid \u2192 magnesium chloride + hydrogen    which word correctly describes all of these reactions?  a combustion  b endothermic  c exothermic  d neutralisation     ",
            "7": "7  \u00a9 ucles 2011 0620/12/o/n/11 [turn over  15 which type of reaction always forms a salt and water?  a exothermic  b neutralisation  c oxidation  d polymerisation      16 an experiment to determine the rate of a chemical reaction could be carried out using the  apparatus shown.    reaction mixture     which reaction is being studied?  a c l 2 + 2kbr \u2192 2kc l + br 2  b mg + h 2so 4 \u2192 mgso 4 + h 2  c nac l + agno 3 \u2192 nano 3 + agc l  d naoh + hc l \u2192 nac l + h 2o      17 copper( ii) carbonate reacts with dilute sulfuric acid.    cuco 3(s) + h 2so 4(aq) \u2192 cuso 4(aq) + co 2(g) + h 2o(l)    the speed of the reaction can be changed by varying the conditions.    which conditions would always increase the speed of this chemical reaction?    1 increase the concentration of the reactants.  2 increase the size of the pieces of copper( ii) carbonate.  3 increase the temperature.  4 increase the volume of sulfuric acid.    a 1, 3 and 4 b 1 and 3 only c 2 and 3 d 3 and 4 only     ",
            "8": "8  \u00a9 ucles 2011 0620/12/o/n/11  18 the table shows some properties of two elements in group vii of the periodic table.    element state at 20  \u00b0c density  / g per cm3 melting point  / \u00b0c  chlorine gas 0.0032 \u2013101   bromine liquid 3.1 000  \u20137     which properties is fluorine likely to have?     state at 20  \u00b0c density  / g per cm3 melting point  / \u00b0c  a gas 0.0017 \u2013220  b gas 0.17 00  \u2013188  c liquid 0.0017 \u2013220  d liquid 0.17 00  \u2013188      19 statement 1:  helium is a reactive gas.    statement 2:  helium can be used to fill balloons.    which is correct?   a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.    20 an alloy contains copper and zinc.    some of the zinc has become oxidised to zinc oxide.    what is the result of adding an excess of dilute sulfuric acid to the alloy?  a a blue solution and a white solid remains.  b a colourless solution and a pink  / brown solid remains.  c the alloy dissolves completely to give a blue solution.  d the alloy dissolves completely to give a colourless solution.     ",
            "9": "9  \u00a9 ucles 2011 0620/12/o/n/11 [turn over  21 an element has the following properties.    \u25cf it forms coloured compounds.  \u25cf it acts as a catalyst.  \u25cf it melts at 1539  \u00b0c.    in which part of the periodic table is the element found?  a group i  b group iv  c group vii  d transition elements     22 the results of three tests on a solution of compound x are shown.    test result  aqueous sodium  hydroxide added white precipitate formed, soluble in excess  aqueous ammonia added white precipitate formed,  soluble in excess  dilute hydrochloric acid added bubbles of gas    what is compound x?  a aluminium carbonate  b aluminium chloride  c zinc carbonate  d zinc chloride     23 which property is not characteristic of a base?  a it reacts with a carbonate to form carbon dioxide.  b it reacts with an acid to form a salt.  c it reacts with an ammonium salt to form ammonia.  d it turns universal indicator paper blue.    ",
            "10": "10  \u00a9 ucles 2011 0620/12/o/n/11  24 a liquid turns white anhydrous copper sulfate blue and has a boiling point of 103 \u00b0c.     which could be the identity of the liquid?  a alcohol  b petrol  c salt solution  d pure water     25 alloy x is strong and has a low density.    alloy y is heavy but is resistant to corrosion.    which could be uses of x and y?     bridge  supports aircraft overhead  cables  a x x y  b x y y  c y x x  d y y x     26 which statements are correct?    1 metals are often used in the form of alloys.  2 stainless steel is an alloy of iron.  3 alloys always contain more than two metals.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     27 which statement is true about all metals?  a they are attracted to a magnet.  b they are weak and brittle.  c they may be used to form alloys.  d they react with water.    ",
            "11": "11  \u00a9 ucles 2011 0620/12/o/n/11 [turn over  28 a metal is extracted from hematite, its oxide ore.    what is the metal and how is the oxide reduced?     metal method of reduction  a al electrolysis  b al heating with carbon  c fe electrolysis  d fe heating with carbon     29 a chemical engineer plans to produce hydrochloric acid.    which metal is best for the reaction container?  a copper  b iron  c magnesium  d zinc     30 when sodium reacts with water, a solution and a gas are produced.    watersodium     the solution is tested with litmus paper and the gas is tested with a splint.    what happens to the litmus paper and to the splint?     litmus paper splint  a blue to red glowing splint relights  b blue to red lighted splint \u2018pops\u2019  c red to blue glowing splint relights  d red to blue lighted splint \u2018pops\u2019     ",
            "12": "12  \u00a9 ucles 2011 0620/12/o/n/11  31 iron is a metal that rusts in the presence of oxygen and water.    mild steel is used for \u2026\u20261\u2026\u2026 and is prevented from rusting by \u2026\u20262\u2026\u2026 .    stainless steel is prevented from rusting by \u2026\u20263\u2026\u2026 it with another metal.    which words correctly complete gaps 1, 2 and 3?     1 2 3  a car bodies greasing covering  b car bodies painting mixing  c cutlery greasing covering  d cutlery painting mixing     32 dry air is passed over hot copper until all the oxygen has reacted.    heatcopper dry air     the volume of gas at the end of the reaction is 120  cm3.    what is the starting volume of dry air?  a 132  cm3 b 150  cm3 c 180  cm3 d 600  cm3     33 in which row is the air pollutant not correctly matched with its source?     air pollutant source  a carbon monoxide incomplete combustion of fuels  b lead compounds burning petrol in cars  c nitrogen oxides decomposing vegetation  d sulfur dioxide burning coal and other fossil fuels     ",
            "13": "13  \u00a9 ucles 2011 0620/12/o/n/11 [turn over  34 which pollutant gas is produced by the decomposition of vegetation?  a carbon monoxide  b methane  c nitrogen oxide  d sulfur dioxide      35 which combination of chemical compounds could be used to produce the fertiliser shown?    supergrown     p     k 21 16 8::     a nh 4no 3, ca 3(po 4)2  b nh 4no 3, co(nh 2)2  c nh 4no 3, k2so 4, (nh 4)2so 4  d (nh 4)3po 4, kc l     36 the diagram represents the molecule of an organic compound.    key = carbon = oxygen= hydrogen     what is the name of the compound?  a ethane  b ethanoic acid   c ethanol  d ethene     ",
            "14": "14  \u00a9 ucles 2011 0620/12/o/n/11  37 when glucose is fermented, ethanol is formed together with  a carbon dioxide.  b ethene.  c methane.  d oxygen.      38 the table shows the composition of four different types of petroleum (crude oil).    fraction arabian heavy  / % arabian light  / % iranian heavy  / % north sea  / %  gasoline 18 21 21 23  kerosene 11.5 13 13 15  diesel 18 20 20 24  fuel oil 52.5 46 46 38    which type of petroleum is best for the motor vehicle industry?  a arabian heavy  b arabian light  c iranian heavy  d north sea     39 which pair of compounds are members of the same homologous series?    a cch hhh hc hh c hhhb hc hh ch hh hc hh ch ch hhh d hc hh ch ohh o ohhc hh cc cch hhh c hh ch nh      ",
            "15": "15  \u00a9 ucles 2011 0620/12/o/n/11  40 petroleum is a very important raw material that is separated into more useful products.    which terms describe petroleum and the method used to separate it?     petroleum is a method used to  separate petroleum  a compound cracking  b compound fractional distillation  c mixture cracking  d mixture fractional distillation     ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2011 0620/12/o/n/11   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w11_qp_13.pdf": {
            "1": "    this document consists of 16 printed pages.  ib11 11_0620_13/rp  \u00a9 ucles 2011  [turn over       *9111606963* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  october/november 2011       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2011 0620/13/o/n/11  1 in which substance are the particles close together and slowly moving past each other?  a air  b ice  c steam  d water      2 two isotopes of helium are he3 2and he.4 2     which two diagrams show the arrangement of particles in these two isotopes?    p n2 1ee ep n22ee p ne e ea np 21ee ep n2 2ee e eb p n21ee p n22ee c p3 p4ee ee dkey = electron = proton= neutron= nucleushe 3 242he      ",
            "3": "3  \u00a9 ucles 2011 0620/13/o/n/11 [turn over  3 the diagram shows the electronic structures of atoms p and q.    key  = electron ee eeee e e eeeee ee epq= nucleus     p and q combine to form a molecule.    what is the formula of this molecule?  a pq 4 b pq c p 2q d p 4q     4 a student was provided with only a thermometer, a stopwatch and a beaker.    what could the student measure?  a 10.5  g solid and 24.8  cm3 liquid  b 10.5  g solid and 25  \u00b0c  c 24.8  cm3 liquid and 45 seconds  d 25  \u00b0c and 45 seconds      5 mixture 1 contains sand and water.    mixture 2 contains salt and water.    which method of separation could be used to obtain each of the required products from each mixture?    mixture 1 mixture 2    to obtain sand to obtain water to obtain salt to obtain water  a crystallisation distillation filtration filtration  b crystallisation filtration filtration distillation  c filtration distillation crystallisation filtration  d filtration filtration crystallisation distillation    ",
            "4": "4  \u00a9 ucles 2011 0620/13/o/n/11  6 concentrated aqueous potassium bromide solution is electrolysed using inert electrodes.    the ions present in the solution are k+, br  \u2013, h+ and oh\u2013.    to which electrodes are the ions attracted during this electrolysis?     attracted to anode attracted to cathode  a br \u2013 and k+ h+ and oh\u2013  b br \u2013 and oh\u2013 h+ and k+  c h+ and k+ br  \u2013 and oh\u2013  d h+ and oh\u2013 br  \u2013 and k+      7 metals could be extracted from their molten chlorides using electrolysis.    which substances are formed at each electrode?     anode cathode  a chlorine hydrogen  b chlorine metal  c hydrogen metal  d metal chlorine      8 the table describes the structures of four particles.    particle number of  protons number of  neutrons number of  electrons  o 8 8 8  o2\u2013 8 8 x  na 11 y 11  na+ 11 12 z    what are the correct values of x, y and z?     x y z  a 9 11 10  b 9 11 11  c 10 12 10  d 10 12 11    ",
            "5": "5  \u00a9 ucles 2011 0620/13/o/n/11 [turn over  9 the diagram shows a section of an overhead power cable.    aluminiumsteel glazed porcelain     which statement explains why a particular substance is used?  a aluminium has a low density and is a good conductor of electricity.  b porcelain is a good conductor of electricity.  c steel can rust in damp air.  d steel is more dense than aluminium.      10 two elements, represented by  and , form a compound.    which diagram shows molecules of the compound?    abc d      11 the relative formula mass, m r, of copper( ii) sulfate, cuso 4, is 160.    which mass of sulfur is present in 160  g of copper( ii) sulfate?  a 16  g b 32  g c 64  g d 128  g     ",
            "6": "6  \u00a9 ucles 2011 0620/13/o/n/11  12 the sign  is used in some equations to show that a reaction is reversible.    two incomplete equations are given.     reactants products  p coc l 2 + 2h 2o coc l 2.2h 2o   q c + o 2 co 2    for which of these reactions can a  sign be correctly used to complete the equation?     p q  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     13 which fuel needs oxygen in order to produce heat energy and which type of reaction produces  the energy?     fuel type of reaction  a a radioactive isotope endothermic  b a radioactive isotope exothermic  c hydrogen endothermic  d hydrogen exothermic    14 some reactions are listed.    methane + oxygen \u2192 carbon dioxide + water  sodium + water \u2192 sodium hydroxide + hydrogen  magnesium + hydrochloric acid \u2192 magnesium chloride + hydrogen    which word correctly describes all of these reactions?  a combustion  b endothermic  c exothermic  d neutralisation     ",
            "7": "7  \u00a9 ucles 2011 0620/13/o/n/11 [turn over  15 which type of reaction always forms a salt and water?  a exothermic  b neutralisation  c oxidation  d polymerisation      16 an experiment to determine the rate of a chemical reaction could be carried out using the  apparatus shown.    reaction mixture     which reaction is being studied?  a c l 2 + 2kbr \u2192 2kc l + br 2  b mg + h 2so 4 \u2192 mgso 4 + h 2  c nac l + agno 3 \u2192 nano 3 + agc l  d naoh + hc l \u2192 nac l + h 2o      17 copper( ii) carbonate reacts with dilute sulfuric acid.    cuco 3(s) + h 2so 4(aq) \u2192 cuso 4(aq) + co 2(g) + h 2o(l)    the speed of the reaction can be changed by varying the conditions.    which conditions would always increase the speed of this chemical reaction?    1 increase the concentration of the reactants.  2 increase the size of the pieces of copper( ii) carbonate.  3 increase the temperature.  4 increase the volume of sulfuric acid.    a 1, 3 and 4 b 1 and 3 only c 2 and 3 d 3 and 4 only     ",
            "8": "8  \u00a9 ucles 2011 0620/13/o/n/11  18 the table shows some properties of two elements in group vii of the periodic table.    element state at 20  \u00b0c density  / g per cm3 melting point  / \u00b0c  chlorine gas 0.0032 \u2013101   bromine liquid 3.1 000  \u20137     which properties is fluorine likely to have?     state at 20  \u00b0c density  / g per cm3 melting point  / \u00b0c  a gas 0.0017 \u2013220  b gas 0.17 00  \u2013188  c liquid 0.0017 \u2013220  d liquid 0.17 00  \u2013188      19 the results of three tests on a solution of compound x are shown.    test result  aqueous sodium  hydroxide added white precipitate formed, soluble in excess  aqueous ammonia added white precipitate formed, soluble in excess  dilute hydrochloric acid added bubbles of gas    what is compound x?  a aluminium carbonate  b aluminium chloride  c zinc carbonate  d zinc chloride     ",
            "9": "9  \u00a9 ucles 2011 0620/13/o/n/11 [turn over  20 an element has the following properties.    \u25cf it forms coloured compounds.  \u25cf it acts as a catalyst.  \u25cf it melts at 1539  \u00b0c.    in which part of the periodic table is the element found?  a group i  b group iv  c group vii  d transition elements     21 an alloy contains copper and zinc.    some of the zinc has become oxidised to zinc oxide.    what is the result of adding an excess of dilute sulfuric acid to the alloy?  a a blue solution and a white solid remains.  b a colourless solution and a pink  / brown solid remains.  c the alloy dissolves completely to give a blue solution.  d the alloy dissolves completely to give a colourless solution.     22 which property is not characteristic of a base?  a it reacts with a carbonate to form carbon dioxide.  b it reacts with an acid to form a salt.  c it reacts with an ammonium salt to form ammonia.  d it turns universal indicator paper blue.    23 statement 1:  helium is a reactive gas.    statement 2:  helium can be used to fill balloons.    which is correct?    a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     ",
            "10": "10  \u00a9 ucles 2011 0620/13/o/n/11  24 a liquid turns white anhydrous copper sulfate blue and has a boiling point of 103 \u00b0c.     which could be the identity of the liquid?  a alcohol  b petrol  c salt solution  d pure water     25 alloy x is strong and has a low density.    alloy y is heavy but is resistant to corrosion.    which could be uses of x and y?     bridge  supports aircraft overhead  cables  a x x y  b x y y  c y x x  d y y x     26 when sodium reacts with water, a solution and a gas are produced.    watersodium     the solution is tested with litmus paper and the gas is tested with a splint.    what happens to the litmus paper and to the splint?     litmus paper splint  a blue to red glowing splint relights  b blue to red lighted splint \u2018pops\u2019  c red to blue glowing splint relights  d red to blue lighted splint \u2018pops\u2019     ",
            "11": "11  \u00a9 ucles 2011 0620/13/o/n/11 [turn over  27 which statements are correct?    1 metals are often used in the form of alloys.  2 stainless steel is an alloy of iron. 3 alloys always contain more than two metals.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3      28 a chemical engineer plans to produce hydrochloric acid.    which metal is best for the reaction container?  a copper  b iron  c magnesium  d zinc     29 which statement is true about all metals?  a they are attracted to a magnet.  b they are weak and brittle.  c they may be used to form alloys.  d they react with water.    30 a metal is extracted from hematite, its oxide ore.    what is the metal and how is the oxide reduced?     metal method of reduction  a al electrolysis  b al heating with carbon  c fe electrolysis  d fe heating with carbon    ",
            "12": "12  \u00a9 ucles 2011 0620/13/o/n/11  31 iron is a metal that rusts in the presence of oxygen and water.    mild steel is used for \u2026\u20261\u2026\u2026 and is prevented from rusting by \u2026\u20262\u2026\u2026 .    stainless steel is prevented from rusting by \u2026\u20263\u2026\u2026 it with another metal.    which words correctly complete gaps 1, 2 and 3?     1 2 3  a car bodies greasing covering  b car bodies painting mixing  c cutlery greasing covering  d cutlery painting mixing     32 in which row is the air pollutant not correctly matched with its source?     air pollutant source  a carbon monoxide incomplete combustion of fuels  b lead compounds burning petrol in cars  c nitrogen oxides decomposing vegetation  d sulfur dioxide burning coal and other fossil fuels      33 dry air is passed over hot copper until all the oxygen has reacted.    heatcopper dry air     the volume of gas at the end of the reaction is 120  cm3.    what is the starting volume of dry air?  a 132  cm3 b 150  cm3 c 180  cm3 d 600  cm3    ",
            "13": "13  \u00a9 ucles 2011 0620/13/o/n/11 [turn over  34 which pollutant gas is produced by the decomposition of vegetation?  a carbon monoxide  b methane  c nitrogen oxide  d sulfur dioxide      35 which combination of chemical compounds could be used to produce the fertiliser shown?    supergrown     p     k 21 16 8::     a nh 4no 3, ca 3(po 4)2  b nh 4no 3, co(nh 2)2  c nh 4no 3, k2so 4, (nh 4)2so 4  d (nh 4)3po 4, kc l     36 the diagram represents the molecule of an organic compound.    key = carbon = oxygen= hydrogen     what is the name of the compound?  a ethane  b ethanoic acid   c ethanol  d ethene     ",
            "14": "14  \u00a9 ucles 2011 0620/13/o/n/11  37 the table shows the composition of four different types of petroleum (crude oil).    fraction arabian heavy  / % arabian light  / % iranian heavy  / % north sea  / %  gasoline 18 21 21 23  kerosene 11.5 13 13 15  diesel 18 20 20 24  fuel oil 52.5 46 46 38    which type of petroleum is best for the motor vehicle industry?  a arabian heavy  b arabian light  c iranian heavy  d north sea     38 which pair of compounds are members of the same homologous series?    a cch hhh hc hh c hhhb hc hh ch hh hc hh ch ch hhh d hc hh ch ohh o ohhc hh cc cch hhh c hh ch nh      ",
            "15": "15  \u00a9 ucles 2011 0620/13/o/n/11  39 petroleum is a very important raw material that is separated into more useful products.    which terms describe petroleum and the method used to separate it?     petroleum is a method used to  separate petroleum  a compound cracking  b compound fractional distillation  c mixture cracking  d mixture fractional distillation      40 when glucose is fermented, ethanol is formed together with  a carbon dioxide.  b ethene.  c methane.  d oxygen.    ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2011 0620/13/o/n/11   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w11_qp_21.pdf": {
            "1": "for examiner\u2019s use 1 2 3 total4 5 6 7 8read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 20. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 october/november 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 18 printed pages and 2 blank pages. [turn overib11 11_0620_21/4rp\u00a9 ucles 2011 *5524108358*",
            "2": "2 0620/21/o/n/11 \u00a9 ucles 2011for examiner\u2019s use1  chromatography can be used to test for the purity of substances.  (a) (i)   describe one area in everyday life where purity of substances is important.   . .  [1]  (ii)  mineral water contains dissolved salts such as magnesium chloride.   which one of the following statements about mineral water is correct?   tick one box.  mineral water boils at slightly above 100  \u00b0c.  mineral water is pure water. mineral water boils at exactly 100  \u00b0c.  another name for mineral water is \ufb01 zzy water. [1]  (b)  the diagram shows the apparatus used to separate different dyes in food colourings. spot of food colouring placed here   label the diagram in the boxes provided using the words below.  chromatography paper origin line solvent solvent front  [2]",
            "3": "3 0620/21/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  the diagram below shows the chromatography of four different food colourings, a, b, c  and d. abcd at the start of the experimentabcd the final chromatogram  (i)  which food colouring, a, b, c or d, contains only one dye?   [1]  (ii)  which three  food colourings have one dye in common?   [1]  (iii) which food colouring contains the greatest number of dyes?   [1] [total: 7]",
            "4": "4 0620/21/o/n/11 \u00a9 ucles 2011for examiner\u2019s use2  a student set up an experiment to demonstrate rusting as shown below.    he made observations at the start of the experiment, after 2 weeks and after  4 weeks.  measuring cylinder air water10  cm38 cm3iron wool 8 cm3 start after 2 weeks after 4 weeks  (a)  what conditions are needed for the iron wool to rust?   ... ..  [2]  (b)  two weeks after the start of the experiment, the volume of air in the measuring cylinder  had decreased. after a further two weeks there was no change in the volume of air.   explain the results of this experiment.   ...    ...    ...    ... ..  [3]  (c)  what change would you observe in the iron wool as it rusted?  appearance at start  ...  appearance after 2 weeks  ..  [2] (d)  rust contains iron( iii) ions.   describe a test for iron( iii) ions.  test     result  .. .  [2]",
            "5": "5 0620/21/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (e)  clean iron reacts with dilute hydrochloric acid. fe  +  2hc l  \u2192  fec l 2  +  h2  write a word equation for this reaction.   ... ..  [2] [total: 11]",
            "6": "6 0620/21/o/n/11 \u00a9 ucles 2011for examiner\u2019s use3  the diagram shows some of the elements in period 3 of the periodic table. na mg si p s c l ar  (a)  from the diagram, choose  (i)  one element which forms a basic oxide.   . .  [1]  (ii)  two elements which form acidic oxides.  ... and ... [2 ]  (b)  describe how metallic character of the elements changes across a period.   ... ..  [1]  (c)  what determines the order of the elements in the periodic table?   ... ..  [1]  (d)  the missing element in the table is aluminium.  (i)  describe the structure of an aluminium atom.   in your description write about  \u25cf the number and types of particles in the nucleus  \u25cf the electrons.   . ...   . ...   . ...   . ...   . ...   . .  [4]",
            "7": "7 0620/21/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (ii)  use the information in the table below to explain why aluminium is used in   preference to iron or titanium for overhead electricity cables.  give two reasons. metalelectrical conductivitydensity in g  / cm3melting point   / \u00b0cstrengthprice in \u00a3  / kg aluminium very good 2.7 660 fairly strong 24 iron good 7.9 1535 strong 3titanium good 4.5 1660 very strong 104   . ...   . ...   . .  [2]  (e)  chlorine is a green gas.   when chlorine is bubbled through an aqueous solution of potassium bromide, the solution  turns orange.   complete the symbol equation for this reaction.  c l  2  +  kbr  \u2192  ...  +  kc l [2]  (f)  argon is a noble gas which is denser than air.    which one of these statements about argon is correct?   tick one box.  argon reacts rapidly with chlorine. argon is used for \ufb01 lling balloons.  argon has a complete outer shell of valency electrons. argon has only two valency electrons in its outer shell. [1] [total: 14]",
            "8": "8 0620/21/o/n/11 \u00a9 ucles 2011for examiner\u2019s use4  ethane is a saturated hydrocarbon. ethene is an unsaturated hydrocarbon.  (a)  describe how you can distinguish between ethane and ethene using aqueous bromine.   ...    ... ..  [2]  (b)  the diagram shows the apparatus used to crack long chain alkanes into alkenes and  shorter chained alkanes in the laboratory. long chain alkane absorbed into mineral woolhot aluminium oxide wateralkene  (i)  state two conditions needed for cracking.   . .  [2]  (ii)  what information in the diagram shows that alkenes are insoluble in water?   . .  [1]  (iii)  propene is an alkene.  the formula of propene is c3h6.  calculate the relative molecular mass of propene. [1]  (iv)  complete the equation for the cracking of the alkane tetradecane, c14h30.  c14h30  \u2192  ...  +  c10h22 [1]",
            "9": "9 0620/21/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  poly(ethene) is formed from ethene monomers.   select two words from the list that describe this reaction.  addition condensation dehydration  fermentation neutralisation polymerisation ... and ... [2 ] [total: 9]",
            "10": "10 0620/21/o/n/11 \u00a9 ucles 2011for examiner\u2019s use5  a pupil studied the effect of temperature on the speed of reaction of aqueous sodium  thiosulfate with dilute hydrochloric acid.   when he added hydrochloric acid to a solution of sodium thiosulfate, a precipitate of sulfur  gradually formed. he recorded the time taken for some writing placed under the \ufb02 ask to  disappear from view. experiment experimentsodium thiosulfate solution (colourless)precipitate of sulfuraddhydrochloricacid   he repeated the experiment at different temperatures.   the table shows his results. temperature / \u00b0ctime taken for the writing to disappear from view  / s 15 100 30 5645 3460 2075 12",
            "11": "11 0620/21/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (a) (i)   on the grid below, plot a graph of the time taken against temperature. 02 0 4 0 temperature  / \u00b0c60 80100 80604020 0time taken /  s [3]  (ii)  at which temperature was the reaction the fastest?   . .  [1]  (iii)  describe how the temperature affects the speed of reaction.   . ...   . .  [1]  (b)  suggest how the speed of this reaction at 30  \u00b0c will change when the concentration of  hydrochloric acid is increased.   ... ..  [1]",
            "12": "12 0620/21/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (c)  the equation for the reaction is  na2s2o3(aq)  +  2hc l (aq)  \u2192  2nac l (aq)  + so2(g)  +  s(s)  +  h2o(l)  (i)  state the name of the salt formed in this reaction.   . .  [1]  (ii)  to which group in the periodic table does sulfur belong?   . .  [1]  (iii)   sulfur dioxide is formed when coal is burnt in power stations.   state one harmful effect of sulfur dioxide on the environment.   . .  [1]  (iv)  sulfur dioxide can be removed in power stations by \ufb02 ue gas desulfurisation.    which one of these compounds is used to remove the sulfur dioxide in this process?   tick one box.  calcium chloride calcium oxide nitrogen dioxide potassium nitrate [1]  (v)  magnesium burns in sulfur dioxide. 2mg  +  so 2  \u2192  2mgo  +  s   refer to this equation to explain why this is a redox reaction.   . ...   . .  [2] [total: 12]",
            "13": "13 0620/21/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use6  the diagram shows the \ufb02 ame from a bunsen burner when its air hole is open. outer zone middle zone inner cone  (a)  in the outer zone of the \ufb02 ame, methane undergoes complete combustion.   complete the equation for the complete combustion of methane.  ch4  +  ...  \u2192  co2  +  2h2o [2]  (b)  in the middle zone of the \ufb02 ame, less air is present and incomplete combustion occurs.   state the name of the poisonous gas formed during the incomplete combustion of  methane.   ... ..  [1]  (c)  the inner cone of the \ufb02 ame contains only unburnt methane.   a student put a match in the bunsen burner as shown in the diagram below.   he then lit the bunsen burner. match head pin   suggest why the match did not catch \ufb01 re.   ... ..  [1]",
            "14": "14 0620/21/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (d)  the products of the complete combustion of methane were drawn through the apparatus  shown below. abto suction pump anhydrous (white) copper sulfatesoda lime granules  (i)  state the name of the substance that turned the white copper sulfate in tube a, blue.   . .  [1]  (ii)  how could you change blue copper sulfate to white copper sulfate?   . .  [1]  (iii)  the soda lime in tube b absorbs carbon dioxide.    state and explain what happens to the mass of the soda lime as the experiment  proceeds.   . ...   . .  [1]  (e)  methane is a greenhouse gas.  (i)  state one source of the methane in the atmosphere.   . .  [1]  (ii)  state one effect of an increased concentration of methane in the atmosphere.   . .  [1] [total: 9]",
            "15": "15 0620/21/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use7  a student studied the reaction of citric acid with sodium hydrogen carbonate. she put a  solution of citric acid in a plastic cup and measured its temperature.   she then added sodium hydrogen carbonate powder and measured the temperature again. thermometer plastic cupsodium hydrogen carbonate citric acid solutionlid  (a)  the temperature of the reaction mixture decreased.   which one of these statements about this reaction is correct?   tick one box.  the reaction released heat energy. the reaction is exothermic. the reaction is endothermic. the products have less energy than the reactants. [1]  (b)  the structure of citric acid is shown below. cooh ch2 c cooh ho ch2 cooh  (i)  on this structure, put a ring around the alcohol functional group. [1]  (ii)  write the simplest formula for citric acid.   . .  [1]",
            "16": "16 0620/21/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (c)  salts of citric acid can be prepared from lemon juice.  (i)  the lemon juice is \ufb01 rst boiled to remove various substances including enzymes.   what do you understand by the term enzyme ?   . ...   . .  [2]  (ii)  the lemon juice is then neutralised with calcium carbonate and solid calcium citrate  is formed.   suggest how the calcium citrate can be separated from the mixture.   . .  [1]  (iii)  carbon dioxide gas is released when citric acid solution reacts with calcium  carbonate.   describe a test for carbon dioxide.  test   .  result    [2]  (d)  the concentration of a citric acid solution can be found by carrying out a titration using  the apparatus shown below. sodium hydroxide solution citric acid solution   describe how to carry out this titration.   ...    ...    ...    ...    ... ..  [3] [total: 11]",
            "17": "17 0620/21/o/n/11 \u00a9 ucles 2011for examiner\u2019s use8  the diagram shows an electrolysis cell for extracting sodium from molten sodium chloride. \u2013\u2013 + \u2013 +b c dasodium e molten sodium chloridesodium power supply  (a) (i)   which letter on the diagram represents  the electrolyte?  .. the cathode?    [2] (ii)  which one of the following substances is most likely to be used as the anode?   put a ring around the correct answer.  graphite sodium sulfur zinc  [1]  (b)  what information from the diagram suggests that sodium is less dense than molten  sodium chloride?   ... ..  [1]  (c)  predict the product formed at the anode during this electrolysis.   ... ..  [1]  (d)  name the gases formed at the anode and cathode when an aqueous  solution of sodium  chloride is electrolysed.  product at the anode  .  product at the cathode    [2] [total: 7]",
            "18": "18 blank page 0620/21/o/n/11 \u00a9 ucles 2011",
            "19": "19 blank page 0620/21/o/n/11 \u00a9 ucles 2011",
            "20": "20 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/21/o/n/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w11_qp_22.pdf": {
            "1": "for examiner\u2019s use 1 2 3 total4 5 6 7read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 20. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 october/november 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 19 printed pages and 1 blank page. [turn overib11 11_0620_22/4rp\u00a9 ucles 2011 *6305238937*",
            "2": "2 0620/22/o/n/11 \u00a9 ucles 2011for examiner\u2019s use1  the diagram shows \ufb01 ve different pieces of laboratory glassware, a, b, c, d and e. abc de  (a)  choose from a, b, c, d or e to answer the following questions.   each letter may be used once, more than once or not at all.   which piece of glassware is best used to  (i)  measure out a volume of liquid accurately,  (ii)  place a spot of liquid on chromatography paper,  (iii)  condense a liquid with a low boiling point,  (iv)  shake two solutions together to mix them,  (v)  deliver a variable volume of solution when performing a titration? [5]",
            "3": "3 0620/22/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (b)  the diagram shows the apparatus used to prepare carbon dioxide in the laboratory. pieces of calcium carbonatewaterconcentrated hydrochloric acid delivery tube gas ja r  (i)  state the name of a rock which is made up largely of calcium carbonate.   . .  [1]  (ii)  which one of these statements about carbon dioxide is correct?    tick one box.  carbon dioxide is lighter than air. carbon dioxide is a liquid at room temperature. carbon dioxide is heavier than air. carbon dioxide has the same density as air. [1]  (iii)  complete the equation for the reaction of calcium carbonate with hydrochloric acid.   caco 3  +  hc l  \u2192  cac l 2  +  co2  +  ... [2] [total: 9]",
            "4": "4 0620/22/o/n/11 \u00a9 ucles 2011for examiner\u2019s use2  many of the elements in the periodic table are metals.  (a)  state one common use for each of the following metals.  (i) copper  ..  [1 ]  (ii)  platinum  ...  [1]  (iii)  aluminium    [1]  (b)  lead is a metal in group iv of the periodic table.  (i)  state one adverse effect of lead on health.   . .  [1]  (ii)  lead has several isotopes.   one isotope of lead is 207pb82   state the number of protons and neutrons in this isotope of lead.   number of protons  ...  [1]   number of neutrons  .  [1]  (c)  sodium is a very reactive metal.   (i)  a student added a few drops of litmus solution to a large beaker of water. she then  dropped a small piece of sodium into the beaker.   describe what the student would observe during the reaction.   . ...   . ...   . .  [3]  (ii)  complete the word equation for the reaction of sodium with water.  sodium  +  water  \u2192  ...  +  ...  ... [2]",
            "5": "5 0620/22/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (iii)  sodium chloride is formed when sodium burns in chlorine.    sodium chloride is an ionic compound.   complete the following sentences about this reaction using words from the list.  electron gains ion loses  molecule negative positive proton  when sodium burns in chlorine, each sodium atom loses an  and becomes a sodium   . each chlorine atom  an electron and becomes a  ion. [4] [total: 15]",
            "6": "6 0620/22/o/n/11 \u00a9 ucles 2011for examiner\u2019s use3  hydrogen peroxide decomposes slowly at room temperature to form water and oxygen.   the reaction is catalysed by manganese( iv) oxide.  2h2o2  \u2192  2h2o  +  o2   a student used the apparatus shown below to study how changing the concentration of  hydrogen peroxide affects the speed of this reaction. hydrogen peroxide manganese( iv) oxidegas syringeoxygen collects here  (a)  apart from the volume of hydrogen peroxide, state two things that the student must keep  the same in each experiment.  1.  ...   2.  ... ..  [2]",
            "7": "7 0620/22/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (b)  the student measured the volume of oxygen produced using three different concentrations  of hydrogen peroxide.   the results are shown on the graph below. 100 80604020 0 0 1 02 03 0 time  / s40 50 60volume of oxygen/  cm3concentration of hydrogen peroxide in g  / dm3 a b c3 2 1  (i)  describe how the speed of the reaction varies with the concentration of hydrogen  peroxide.   . .  [1]  (ii)  explain why the \ufb01 nal volume of oxygen given off is less for graph b than for graph a.   . ...   . .  [1]  (iii)  from the graph, determine   the time taken for the reaction to be completed when 3  g / dm3 hydrogen peroxide  (line a) was used.   . .  [1]   the volume of oxygen produced by 2  g / dm3 hydrogen peroxide (line b) in the \ufb01 rst 15 seconds.   . .  [1]",
            "8": "8 0620/22/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (c)  the student then tested various compounds to see how well they catalysed the reaction.  he used the same concentration of hydrogen peroxide in each experiment.   the table shows the time taken to produce 20  cm3 of oxygen using each compound as  a catalyst. compoundtime taken to produce 20  cm3 of oxygen  / s copper( ii) oxide 130 lead( iv) oxide 15 magnesium oxide did not produce any oxygenmanganese( iv) oxide 18   put these compounds in order of their effectiveness as catalysts. worst catalyst best catalyst [1] [total: 7]",
            "9": "9 0620/22/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use4  natural gas and the hydrocarbons obtained from the distillation of petroleum are important  fuels.  (a)  state the name of the main substance present in natural gas.   ... ..  [1]  (b)  petroleum is a thick liquid.   describe the liquid state in terms of  \u25cf how close the particles are to each other,  \u25cf the arrangement of the particles,  \u25cf the movement of the particles.   ...    ...    ...    ... ..  [3]  (c)  the diagram shows a distillation column used to separate petroleum into fractions. refinery gasfractions x kerosene y fuel oil lubricating oil bitumengasoline  (i)  on the diagram, draw an arrow to show where the petroleum vapour enters the  column. [1]  (ii)  what do you understand by the term fraction ?   . ...   . .  [2]",
            "10": "10 0620/22/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (iii)  in the diagram on page 9, two fractions have not been named.   state the name of  fraction x  ...  fraction y  .  [2]  (iv)  one of the re \ufb01 nery gases is ethane.   draw the structure of ethane showing all atoms and bonds. [1]  (v)  which one of these phrases describes ethane correctly?   tick one box.  ethane is an unsaturated hydrocarbon. ethane is a saturated hydrocarbon. ethane polymerises to form poly(ethene). ethane is an alkene. [1] [total: 11]",
            "11": "11 0620/22/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use5 (a)   match the phrases on the left with the de \ufb01 nitions on the right.   the \ufb01 rst one has been done for you. relative formula massan atom that has become charged moleculethe smallest part of an element which can take part in a chemical change atomtwo or more atoms covalently bonded together ionthe sum of the relative atomic masses in a compound [3]  (b)  sodium hydroxide, naoh, is an ionic compound which dissolves in water to form a  strongly alkaline solution.  (i)  which one of the following best describes the ph of a concentrated aqueous solution  of sodium hydroxide?   put a ring around the correct answer.  ph 2 ph 5 ph 7 ph 8 ph 13  [1]  (ii)  calculate the relative formula mass of sodium hydroxide. [1]  (iii)  the equation describes how sodium hydroxide reacts with hydrochloric acid. naoh  +  hc l  \u2192  nac l  +  h2o   what type of chemical reaction is this?   . .  [1]",
            "12": "12 0620/22/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (iv)  a student used a syringe to add 1  cm3 portions of hydrochloric acid to an aqueous  solution of sodium hydroxide. hydrochloric acidsyringe sodium hydroxide solution   describe how the ph of the solution in the beaker changes as the hydrochloric acid  is added until the acid is in excess.   . ...   . ...   . .  [2]",
            "13": "13 0620/22/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  the diagram shows the apparatus used to electrolyse concentrated aqueous sodium  chloride. anode cathodeconcentrated aqueous sodium chloridegases +\u2013   give a description of this electrolysis.   in your description include  \u25cf  what substance the electrodes are made from and the reason for using this  substance  \u25cf   what you would observe during the electrolysis  \u25cf   the names of the substances produced at each electrode.   ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 14]",
            "14": "14 0620/22/o/n/11 \u00a9 ucles 2011for examiner\u2019s use6  when coal is heated in the absence of air, coke is formed together with a gas called coal gas  and a liquid which contains ammonia.  (a)  coke is largely carbon.   state one use of coke in industry.   ... ..  [1]  (b)  two other forms of carbon are diamond and graphite.  (i)  use your knowledge of the structure of diamond and graphite to explain   why graphite is a good lubricant.   . ...   . .  [1]   why diamond is very hard.   . .  [1]  (ii)  give one use of diamond that depends on its hardness.   . .  [1]  (c)  the liquid which contains ammonia can be reacted with sulfuric acid.  (i)  complete the word equation for this reaction  ammonia  +  sulfuric acid  \u2192   [1]  (ii)  which one of the following elements do most fertilisers contain?   put a ring around the correct answer.  chlorine nitrogen sodium sulfur  [1]  (d)  coal gas contains methane.   complete the diagram to show how the electrons are arranged in a molecule of methane. h hhh c [1]",
            "15": "15 0620/22/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (e)  when coal is burnt, sulfur dioxide is given off.   which two of the following statements about sulfur dioxide are correct?   tick two boxes.  sulfur dioxide is an acidic oxide. about 20  % of the air is sulfur dioxide.  most of the sulfur dioxide in the air comes from car exhausts. sulfur dioxide contributes to acid rain. [2] [total: 9]",
            "16": "16 0620/22/o/n/11 \u00a9 ucles 2011for examiner\u2019s use7  ethanol, c2h5oh, is a member of the alcohol homologous series.  (a) (i)   give two characteristics of a homologous series.  1.  .. ..  2.  ..   [2]  (ii)  draw the structure of ethanol showing all atoms and bonds. [1]  (b)  one use of ethanol is as a solvent.   a pupil studied the reaction of iodine with zinc.   she \ufb01 rst dissolved a few crystals of iodine in ethanol and recorded the temperature of the  solution.   the temperature was 18  \u00b0c.   she then added excess powdered zinc and recorded the temperature again.   the new temperature was 37  \u00b0c. temperature 18  \u00b0c iodine dissolved in ethanoltemperature 37  \u00b0c excess zinc  (i)  is this reaction endothermic or exothermic?   explain your answer.   . ...   . .  [1]  (ii)  what colour is solid iodine?   . .  [1]",
            "17": "17 0620/22/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  the equation for the reaction is zinc  +  iodine  \u2192  zinc iodide   when the reaction is complete, the mixture contains zinc iodide dissolved in ethanol and  unreacted zinc powder.   suggest how you can get crystals of zinc iodide from the reaction mixture.   ...    ...    ... ..  [2]  (d)  the diagram shows the structure of zinc iodide. i \u2013 i \u2013i \u2013 i \u2013 i \u2013i \u2013 zn2+zn2+ zn2+zn2+zn2+i \u2013 i \u2013 i \u2013i \u2013  (i)  what is the simplest formula for zinc iodide?   . .  [1]  (ii)  the list below shows four different types of structure.   what type of structure is zinc iodide?   put a ring around the correct answer. giant covalent giant ionic metallic molecular [1]",
            "18": "18 0620/22/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (e)  the equation for the reaction of zinc with dilute nitric acid is 4zn  +  10hno3  \u2192  4zn(no3)2  +  nh4no3  +  3h2o  write a word equation for this reaction.  ... ..  [3]  (f)  describe a test for ammonium ions.  test     result  .. ...   ... ..  [3] [total: 15]",
            "19": "19 blank page 0620/22/o/n/11 \u00a9 ucles 2011",
            "20": "20 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/22/o/n/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w11_qp_23.pdf": {
            "1": "for examiner\u2019s use 1 2 3 total4 5 6 7read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 20. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/23   paper 2 october/november 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 19 printed pages and 1 blank page. [turn overib11 11_0620_23/fp\u00a9 ucles 2011 *1913993284*",
            "2": "2 0620/23/o/n/11 \u00a9 ucles 2011for examiner\u2019s use1  the diagram shows \ufb01 ve different pieces of laboratory glassware, a, b, c, d and e. abc de  (a)  choose from a, b, c, d or e to answer the following questions.   each letter may be used once, more than once or not at all.   which piece of glassware is best used to  (i)  measure out a volume of liquid accurately,  (ii)  place a spot of liquid on chromatography paper,  (iii)  condense a liquid with a low boiling point,  (iv)  shake two solutions together to mix them,  (v)  deliver a variable volume of solution when performing a titration? [5]",
            "3": "3 0620/23/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (b)  the diagram shows the apparatus used to prepare carbon dioxide in the laboratory. pieces of calcium carbonatewaterconcentrated hydrochloric acid delivery tube gas ja r  (i)  state the name of a rock which is made up largely of calcium carbonate.   . .  [1]  (ii)  which one of these statements about carbon dioxide is correct?    tick one box.  carbon dioxide is lighter than air. carbon dioxide is a liquid at room temperature. carbon dioxide is heavier than air. carbon dioxide has the same density as air. [1]  (iii)  complete the equation for the reaction of calcium carbonate with hydrochloric acid.   caco 3  +  hc l  \u2192  cac l 2  +  co2  +  ... [2] [total: 9]",
            "4": "4 0620/23/o/n/11 \u00a9 ucles 2011for examiner\u2019s use2  many of the elements in the periodic table are metals.  (a)  state one common use for each of the following metals.  (i) copper  ..  [1 ]  (ii)  platinum  ...  [1]  (iii)  aluminium    [1]  (b)  lead is a metal in group iv of the periodic table.  (i)  state one adverse effect of lead on health.   . .  [1]  (ii)  lead has several isotopes.   one isotope of lead is 207pb82   state the number of protons and neutrons in this isotope of lead.   number of protons  ...  [1]   number of neutrons  .  [1]  (c)  sodium is a very reactive metal.   (i)  a student added a few drops of litmus solution to a large beaker of water. she then  dropped a small piece of sodium into the beaker.   describe what the student would observe during the reaction.   . ...   . ...   . .  [3]  (ii)  complete the word equation for the reaction of sodium with water.  sodium  +  water  \u2192  ...  +  ...  ... [2]",
            "5": "5 0620/23/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (iii)  sodium chloride is formed when sodium burns in chlorine.    sodium chloride is an ionic compound.   complete the following sentences about this reaction using words from the list.  electron gains ion loses  molecule negative positive proton  when sodium burns in chlorine, each sodium atom loses an  and becomes a sodium   . each chlorine atom  an electron and becomes a  ion. [4] [total: 15]",
            "6": "6 0620/23/o/n/11 \u00a9 ucles 2011for examiner\u2019s use3  hydrogen peroxide decomposes slowly at room temperature to form water and oxygen.   the reaction is catalysed by manganese( iv) oxide.  2h2o2  \u2192  2h2o  +  o2   a student used the apparatus shown below to study how changing the concentration of  hydrogen peroxide affects the speed of this reaction. hydrogen peroxide manganese( iv) oxidegas syringeoxygen collects here  (a)  apart from the volume of hydrogen peroxide, state two things that the student must keep  the same in each experiment.  1.  ...   2.  ... ..  [2]",
            "7": "7 0620/23/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (b)  the student measured the volume of oxygen produced using three different concentrations  of hydrogen peroxide.   the results are shown on the graph below. 100 80604020 0 0 1 02 03 0 time  / s40 50 60volume of oxygen/  cm3concentration of hydrogen peroxide in g  / dm3 a b c3 2 1  (i)  describe how the speed of the reaction varies with the concentration of hydrogen  peroxide.   . .  [1]  (ii)  explain why the \ufb01 nal volume of oxygen given off is less for graph b than for graph a.   . ...   . .  [1]  (iii)  from the graph, determine   the time taken for the reaction to be completed when 3  g / dm3 hydrogen peroxide  (line a) was used.   . .  [1]   the volume of oxygen produced by 2  g / dm3 hydrogen peroxide (line b) in the \ufb01 rst 15 seconds.   . .  [1]",
            "8": "8 0620/23/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (c)  the student then tested various compounds to see how well they catalysed the reaction.  he used the same concentration of hydrogen peroxide in each experiment.   the table shows the time taken to produce 20  cm3 of oxygen using each compound as  a catalyst. compoundtime taken to produce 20  cm3 of oxygen  / s copper( ii) oxide 130 lead( iv) oxide 15 magnesium oxide did not produce any oxygenmanganese( iv) oxide 18   put these compounds in order of their effectiveness as catalysts. worst catalyst best catalyst [1] [total: 7]",
            "9": "9 0620/23/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use4  natural gas and the hydrocarbons obtained from the distillation of petroleum are important  fuels.  (a)  state the name of the main substance present in natural gas.   ... ..  [1]  (b)  petroleum is a thick liquid.   describe the liquid state in terms of  \u25cf how close the particles are to each other,  \u25cf the arrangement of the particles,  \u25cf the movement of the particles.   ...    ...    ...    ... ..  [3]  (c)  the diagram shows a distillation column used to separate petroleum into fractions. refinery gasfractions x kerosene y fuel oil lubricating oil bitumengasoline  (i)  on the diagram, draw an arrow to show where the petroleum vapour enters the  column. [1]  (ii)  what do you understand by the term fraction ?   . ...   . .  [2]",
            "10": "10 0620/23/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (iii)  in the diagram on page 9, two fractions have not been named.   state the name of  fraction x  ...  fraction y  .  [2]  (iv)  one of the re \ufb01 nery gases is ethane.   draw the structure of ethane showing all atoms and bonds. [1]  (v)  which one of these phrases describes ethane correctly?   tick one box.  ethane is an unsaturated hydrocarbon. ethane is a saturated hydrocarbon. ethane polymerises to form poly(ethene). ethane is an alkene. [1] [total: 11]",
            "11": "11 0620/23/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use5 (a)   match the phrases on the left with the de \ufb01 nitions on the right.   the \ufb01 rst one has been done for you. relative formula massan atom that has become charged moleculethe smallest part of an element which can take part in a chemical change atomtwo or more atoms covalently bonded together ionthe sum of the relative atomic masses in a compound [3]  (b)  sodium hydroxide, naoh, is an ionic compound which dissolves in water to form a  strongly alkaline solution.  (i)  which one of the following best describes the ph of a concentrated aqueous solution  of sodium hydroxide?   put a ring around the correct answer.  ph 2 ph 5 ph 7 ph 8 ph 13  [1]  (ii)  calculate the relative formula mass of sodium hydroxide. [1]  (iii)  the equation describes how sodium hydroxide reacts with hydrochloric acid. naoh  +  hc l  \u2192  nac l  +  h2o   what type of chemical reaction is this?   . .  [1]",
            "12": "12 0620/23/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (iv)  a student used a syringe to add 1  cm3 portions of hydrochloric acid to an aqueous  solution of sodium hydroxide. hydrochloric acidsyringe sodium hydroxide solution   describe how the ph of the solution in the beaker changes as the hydrochloric acid  is added until the acid is in excess.   . ...   . ...   . .  [2]",
            "13": "13 0620/23/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  the diagram shows the apparatus used to electrolyse concentrated aqueous sodium  chloride. anode cathodeconcentrated aqueous sodium chloridegases +\u2013   give a description of this electrolysis.   in your description include  \u25cf  what substance the electrodes are made from and the reason for using this  substance  \u25cf   what you would observe during the electrolysis  \u25cf   the names of the substances produced at each electrode.   ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 14]",
            "14": "14 0620/23/o/n/11 \u00a9 ucles 2011for examiner\u2019s use6  when coal is heated in the absence of air, coke is formed together with a gas called coal gas  and a liquid which contains ammonia.  (a)  coke is largely carbon.   state one use of coke in industry.   ... ..  [1]  (b)  two other forms of carbon are diamond and graphite.  (i)  use your knowledge of the structure of diamond and graphite to explain   why graphite is a good lubricant.   . ...   . .  [1]   why diamond is very hard.   . .  [1]  (ii)  give one use of diamond that depends on its hardness.   . .  [1]  (c)  the liquid which contains ammonia can be reacted with sulfuric acid.  (i)  complete the word equation for this reaction  ammonia  +  sulfuric acid  \u2192   [1]  (ii)  which one of the following elements do most fertilisers contain?   put a ring around the correct answer.  chlorine nitrogen sodium sulfur  [1]  (d)  coal gas contains methane.   complete the diagram to show how the electrons are arranged in a molecule of methane. h hhh c [1]",
            "15": "15 0620/23/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (e)  when coal is burnt, sulfur dioxide is given off.   which two of the following statements about sulfur dioxide are correct?   tick two boxes.  sulfur dioxide is an acidic oxide. about 20  % of the air is sulfur dioxide.  most of the sulfur dioxide in the air comes from car exhausts. sulfur dioxide contributes to acid rain. [2] [total: 9]",
            "16": "16 0620/23/o/n/11 \u00a9 ucles 2011for examiner\u2019s use7  ethanol, c2h5oh, is a member of the alcohol homologous series.  (a) (i)   give two characteristics of a homologous series.  1.  .. ..  2.  ..   [2]  (ii)  draw the structure of ethanol showing all atoms and bonds. [1]  (b)  one use of ethanol is as a solvent.   a pupil studied the reaction of iodine with zinc.   she \ufb01 rst dissolved a few crystals of iodine in ethanol and recorded the temperature of the  solution.   the temperature was 18  \u00b0c.   she then added excess powdered zinc and recorded the temperature again.   the new temperature was 37  \u00b0c. temperature 18  \u00b0c iodine dissolved in ethanoltemperature 37  \u00b0c excess zinc  (i)  is this reaction endothermic or exothermic?   explain your answer.   . ...   . .  [1]  (ii)  what colour is solid iodine?   . .  [1]",
            "17": "17 0620/23/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  the equation for the reaction is zinc  +  iodine  \u2192  zinc iodide   when the reaction is complete, the mixture contains zinc iodide dissolved in ethanol and  unreacted zinc powder.   suggest how you can get crystals of zinc iodide from the reaction mixture.   ...    ...    ... ..  [2]  (d)  the diagram shows the structure of zinc iodide. i \u2013 i \u2013i \u2013 i \u2013 i \u2013i \u2013 zn2+zn2+ zn2+zn2+zn2+i \u2013 i \u2013 i \u2013i \u2013  (i)  what is the simplest formula for zinc iodide?   . .  [1]  (ii)  the list below shows four different types of structure.   what type of structure is zinc iodide?   put a ring around the correct answer. giant covalent giant ionic metallic molecular [1]",
            "18": "18 0620/23/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (e)  the equation for the reaction of zinc with dilute nitric acid is 4zn  +  10hno3  \u2192  4zn(no3)2  +  nh4no3  +  3h2o  write a word equation for this reaction.  ... ..  [3]  (f)  describe a test for ammonium ions.  test     result  .. ...   ... ..  [3] [total: 15]",
            "19": "19 blank page 0620/23/o/n/11 \u00a9 ucles 2011",
            "20": "20 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/23/o/n/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w11_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) october/november 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib11 11_0620_31/2rp\u00a9 ucles 2011 *0279941738* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/31/o/n/11blank page \u00a9 ucles 2011",
            "3": "3 0620/31/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use1  this question is concerned with the following oxides.  sulfur dioxide  carbon monoxide lithium oxide aluminium oxide nitrogen dioxide strontium oxide  (a) (i)   which of the above oxides will react with hydrochloric acid but not with aqueous  sodium hydroxide?   . .  [1]  (ii)  which of the above oxides will react with aqueous sodium hydroxide but not with hydrochloric acid?   . .  [1]  (iii)  which of the above oxides will react with both hydrochloric acid and aqueous sodium  hydroxide?   . .  [1]  (iv)  which of the above oxides will not react with hydrochloric acid or with aqueous sodium hydroxide?   . .  [1]  (b)  two of the oxides are responsible for acid rain.   identify the two oxides and explain their presence in the atmosphere.   ...    ...    ...    ...    ... ..  [5]",
            "4": "4 0620/31/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (c)   lithium oxide is an ionic compound.  (i)  identify another ionic oxide in the list on page 3.   . .  [1]  (ii)  draw a diagram which shows the formula of lithium oxide, the charges on the ions  and the arrangement of the valency electrons around the negative ion.   use x to represent an electron from an atom of oxygen.   use o to represent an electron from an atom of lithium. [2] [total: 12]",
            "5": "5 0620/31/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use2  two important greenhouse gases are methane and carbon dioxide.  (a)  methane is twenty times more effective as a greenhouse gas than carbon dioxide. the  methane in the atmosphere comes from both natural and industrial sources.  (i)  describe two natural sources of methane.   . ...   . .  [2]  (ii)  although methane can persist in the atmosphere for up to 15 years, it is eventually removed by oxidation.   what are the products of this oxidation?   . .  [2]  (b)  how do the processes of respiration, combustion and photosynthesis determine the percentage of carbon dioxide in the atmosphere?   ...    ...    ...    ... ..  [4] [total: 8]",
            "6": "6 0620/31/o/n/11 \u00a9 ucles 2011for examiner\u2019s use3  aluminium is extracted by the electrolysis of a molten mixture of alumina, which is aluminium  oxide, and cryolite. carbon cathode (\u2013)carbon anode (+) mixture of aluminiumoxide and cryolite aluminium at cathode900  \u00b0cwaste gases, oxygen and carbon dioxide, from anode  (a) (i)   alumina is obtained from the main ore of aluminium.   name this ore.   . .  [1]  (ii)  explain why it is necessary to use a mixture, alumina and cryolite, rather than just alumina.   . ...   . .  [2]  (iii)  copper can be extracted by the electrolysis of an aqueous solution.   suggest why the electrolysis of an aqueous solution cannot be used to extract aluminium.   . ...   . ...   . .  [2]  (b)  the ions which are involved in the electrolysis are a l  3+ and o2\u2013. the products of this  electrolysis are given on the diagram.   explain how they are formed. use equations where appropriate.   ...    ...    ...    ... ..  [4]",
            "7": "7 0620/31/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  the uses of a metal are determined by its properties.  (i)  foods which are acidic can be supplied in aluminium containers. chicken inlemon saucefood that is acidic aluminium containe r   explain why the acid in the food does not react with the aluminium.   . ...   . .  [1]  (ii)  explain why overhead electrical power cables are made from aluminium with a steel  core. aluminium steel core   . ...   . ...   . .  [3] [total: 13]",
            "8": "8 0620/31/o/n/11 \u00a9 ucles 2011for examiner\u2019s use4  reversible reactions can come to equilibrium. the following are three examples of types of  gaseous equilibria.  a2(g)  +  b2(g)    2ab(g) reaction 1  a2(g)  +  3b2(g)    2ab3(g) reaction 2  2ab2(g)    2ab(g)  +  b2(g) reaction 3  (a)  explain the term equilibrium .   ...    ... ..  [2]  (b)  the following graphs show how the percentage of products of a reversible reaction at equilibrium could vary with pressure.   for each graph, decide whether the percentage of products decreases, increases or stays the same when the pressure is increased , then match each graph to one of the  above reactions and give a reason for your choice.  (i) % product at equilibrium pressure00  effect on percentage of products  ...  reaction   ..  reason  .. ..   . .  [3]  (ii) % product at equilibrium pressure00  effect on percentage of products  ... reaction   ..  reason  .. ..   . .  [3]",
            "9": "9 0620/31/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (iii) % product at equilibrium pressure00  effect on percentage of products  ...  reaction   ..  reason  .. ..   . .  [3] [total: 11]",
            "10": "10 0620/31/o/n/11 \u00a9 ucles 2011for examiner\u2019s use5  the rate of the reaction between iron and aqueous bromine can be investigated using the  apparatus shown below. piece of metal (iron) solution of bromineattached to stirrer piece of metal rotates  (a)  a piece of iron was weighed and placed in the apparatus. it was removed at regular intervals and the clock was paused. the piece of iron was washed, dried, weighed and replaced. the clock was restarted.   this was continued until the solution was colourless.   the mass of iron was plotted against time. the graph shows the results obtained. mass of iron time (iron was in solution of bromine)00  (i)  suggest an explanation for the shape of the graph.   . ...   . ...   . .  [3]  (ii)  predict the shape of the graph if a similar piece of iron with a much rougher surface had been used.   explain your answer.   . ...   . .  [2]",
            "11": "11 0620/31/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (iii)  describe how you could \ufb01 nd out if the rate of this reaction depended on the speed  of stirring.   . ...   . ...   . .  [2]  (b)  iron has two oxidation states +2 and +3. there are two possible equations for the redox  reaction between iron and bromine.  fe  +  br2  \u2192  fe2+  +  2br  \u2013  2fe  +  3br2  \u2192  2fe3+  +  6br  \u2013  (i)  indicate, on the \ufb01 rst equation, the change which is oxidation. give a reason for your  choice.   . ...   . .  [2]  (ii)  which substance in the \ufb01 rst equation is the reductant (reducing agent)?   . .  [1]  (c)  describe how you could test the solution to \ufb01 nd out which ion, fe2+ or fe3+, is present.   ...    ...    ... ..  [3] [total: 13]",
            "12": "12 0620/31/o/n/11 \u00a9 ucles 2011for examiner\u2019s use6  structural formulae are an essential part of organic chemistry.  (a)  draw the structural formula of each of the following. show all the bonds in the structure.  (i)  ethanoic acid [1]  (ii)  ethanol [1]  (b) (i)   ethanoic acid and ethanol react to form an ester.   what is the name of this ester?   . .  [1]  (ii)  the same linkage is found in polyesters. draw the structure of the polyester which  can be formed from the monomers shown below. hooc  \u2014 c6h4 \u2014 cooh  and  ho  \u2014 ch2 \u2014 ch2 \u2014 oh [3]  (iii)  describe the pollution problems caused by non-biodegradable polymers.    . ...   . ...   . .  [2]",
            "13": "13 0620/31/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  two macromolecules have the same amide linkage.    nylon, a synthetic polymer, has the following structure. co hn hn hn co co hn co co   protein, a natural macromolecule, has the following structure. n c o h hn c o hn c o o hn c   how are they different?   ...    ...    ... ..  [2] [total: 10]",
            "14": "14 0620/31/o/n/11 \u00a9 ucles 2011for examiner\u2019s use7  some hydroxides, nitrates and carbonates decompose when heated.  (a) (i)   name a metal hydroxide which does not decompose when heated.   . .  [1]  (ii)  write the equation for the thermal decomposition of copper( ii) hydroxide.   . .  [2]  (iii)  suggest why these two hydroxides behave differently.   . .  [1]  (b) (i)   metal nitrates, except those of the group 1 metals, form three products when heated.  name the products formed when zinc nitrate is heated.   . ...   . .  [2]  (ii)  write the equation for the thermal decomposition of potassium nitrate.   . .  [2]  (c)  there are three possible equations for the thermal decomposition of sodium  hydrogencarbonate.  2nahco3(s)  \u2192  na2o(s)  +  2co2(g)  +  h2o(g) equation 1  nahco3(s)  \u2192  naoh(s)  +  co2(g) equation 2  2nahco3(s)  \u2192  na2co3(s)  +  co2(g)  +  h2o(g) equation 3   the following experiment was carried out to determine which one of the above is the  correct equation.   a known mass of sodium hydrogencarbonate was heated for ten minutes. it was then  allowed to cool and weighed.  results   mass of sodium hydrogencarbonate = 3.36  g   mass of the residue = 2.12  g  calculation   mr for nahco3 = 84  g; mr for na2o = 62  g; mr for naoh = 40  g   mr for na2co3 = 106  g  (i)  number of moles of nahco3 used = ... [1]",
            "15": "15 0620/31/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (ii)  if residue is na2o, number of moles of na2o = ...   if residue is naoh, number of moles of naoh = ...   if residue is na2co3, number of moles of na2co3 = ... [2]  (iii)  use the number of moles calculated in (i) and (ii) to decide which one of the three  equations is correct. explain your choice.   . ...   . ...   . .  [2] [total: 13]",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/31/o/n/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w11_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) october/november 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib11 11_0620_32/2rp\u00a9 ucles 2011 *4888728650* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/32/o/n/11 \u00a9 ucles 2011for examiner\u2019s use1  cobalt is an element in period 4 of the periodic table.  (a)  use your copy of the periodic table to help you complete the table below. particlenumber of protonsnumber of neutronsnumber of electrons co co2+ [2]  (b)  60co is a cobalt isotope.  (i)  explain the term isotope .   . ...   . ...   . .  [2]  (ii)  explain why two isotopes of the same element have identical chemical properties.   . .  [1]  (iii)  state one industrial use and one medical use of radioactive isotopes.  industrial use  ...  [1]  medical use  .  [1] [total: 7]",
            "3": "3 0620/32/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use2  sulfur is needed for the production of sulfuric acid. two of the major sources of sulfur are  \u25cf underground deposits of the element sulfur,  \u25cf sulfur compounds from natural gas and petroleum.  (a)  explain why sulfur and its compounds are removed from these fuels before they are  burned.   ...    ... ..  [2]  (b)  sulfur dioxide is made by spraying molten sulfur into air. the sulfur ignites and sulfur  dioxide is formed.  (i)  suggest why molten sulfur is used in the form of a \ufb01 ne spray.   . ...   . .  [2]  (ii)  explain why traces of sulfur dioxide act as a preservative in fruit juices.   . .  [1]  (iii)  state another use of sulfur dioxide.   . .  [1]  (c)  describe how sulfur dioxide is changed into sulfur trioxide. give the reaction conditions  and an equation.   ...    ...    ...    ... ..  [4]  (d)  complete the following equations for the formation of sulfuric acid from sulfur trioxide.  so3  +  ...  \u2192  h2s2o7  h2s2o7  +  \u2026\u2026\u2026.  \u2192  ..h2so4 [2] [total: 12]",
            "4": "4 0620/32/o/n/11 \u00a9 ucles 2011for examiner\u2019s use3  antimony, sb, is an element in group v.  (a)  the main ore of antimony is its sul \ufb01 de. the extraction of antimony is similar to that of  zinc.   describe how each of these changes in the extraction of antimony is carried out.  (i)  antimony sul \ufb01 de to antimony oxide    . .  [1]  (ii)  antimony oxide to antimony   . .  [1]  (b)  antimony oxide is a white powder which is insoluble in water.   describe how you would \ufb01 nd out if it is a basic, an acidic or an amphoteric oxide.   ...    ...    ...    ... ..  [4]  (c)  when antimony chloride is added to water, a faint white precipitate forms and the mixture  slowly goes cloudy.  forward sbc l 3(aq)  +  h2o(l)    2hc l (aq)  +  sboc l (s)  colourless backward white  (i) explain why after some time the appearance of the mixture remains unchanged.   . ...   . .  [2]  (ii)  when a few drops of concentrated hydrochloric acid are added to the mixture, it  changes to a colourless solution. suggest an explanation.   . ...   . .  [1]  (iii)  suggest how you could make the colourless solution go cloudy.   . .  [1] [total: 10]",
            "5": "5 0620/32/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use4  the structure of an element or compound determines its physical properties.   scandium \ufb02 uoride and silicon( iv) oxide have giant structures.  (a)  scandium \ufb02 uoride is an ionic compound.  (i)  the valency of scandium is three. draw a diagram which shows the formula of the  compound, the charges on the ions and the arrangement of the valency electrons around the negative ion.  use x to represent an electron from a scandium atom. use o to represent an electron from a \ufb02 uorine atom. [3]  (ii)  the melting point of scandium \ufb02 uoride is 1552  \u00b0c. explain why scandium \ufb02 uoride  has a high melting point.   . ...   . .  [1]  (b)  silicon( iv) oxide has a macromolecular structure.  (i)  describe the structure of silicon( iv) oxide. you may use a diagram. [3]  (ii)  how does the electrical conductivity of these two compounds differ?   . ...   . .  [1]  (iii) explain the difference in conductivity.   . ...   . .  [2] [total: 10]",
            "6": "6 0620/32/o/n/11 \u00a9 ucles 2011for examiner\u2019s use5  the alcohols form a homologous series. two characteristics of a homologous series are  that the physical properties of the members vary in a predictable way and they have similar chemical properties.  (a)  complete the table. name formulamass of one mole  / gboiling point / \u00b0c methanol ch3 \u2013 oh 32 64 ethanol ch3 \u2013 ch2 \u2013 oh 46 78 propan-1-ol ch3 \u2013 ch2 \u2013 ch2 \u2013 oh 60 98 butan-1-ol ch3 \u2013 ch2 \u2013 ch2 \u2013 ch2 \u2013 oh 74 118 pentan-1-ol 138hexan-1-ol ch 3 \u2013 ch2 \u2013 ch2 \u2013 ch2 \u2013 ch2 \u2013 ch2 \u2013 oh 102 [3]  (b)  give two other characteristics of a homologous series.   ...    ... ..  [2]  (c)  draw a diagram showing the arrangement of the valency electrons in one molecule of  the covalent compound methanol.  use x to represent an electron from a carbon atom. use o to represent an electron from an oxygen atom. use \u25cf to represent an electron from a hydrogen atom. [3]",
            "7": "7 0620/32/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (d)   alcohols can be oxidised to carboxylic acids by heating with acidic potassium  manganate( vii).  (i)  draw the structural formula of the carboxylic acid formed by the oxidation of propan-1-ol. show all the bonds. [1]  (ii)  describe how ethanol could be oxidised to ethanoic acid by fermentation.   . ...   . .  [2]  (e)  propan-1-ol and ethanoic acid react together to form an ester. give its name and structural  formula.  name  ...  [1 ]  formula [1] [total: 13]",
            "8": "8 0620/32/o/n/11 \u00a9 ucles 2011for examiner\u2019s use6  soluble salts can be made by the neutralisation of an acid by a base. insoluble salts can be  made by precipitation.  (a)  the following is a brief description of the preparation of the soluble salt, nickel( ii) chloride-6-water, from the insoluble base nickel( ii) carbonate.   nickel( ii) carbonate is added in small amounts to hot dilute hydrochloric acid until it is  in excess. the mixture is \ufb01 ltered. the \ufb01 ltrate is partially evaporated and then allowed to  cool until crystals of nickel( ii) chloride-6-water form.  (i)  why is it necessary to use excess carbonate?   . ...   . .  [1]  (ii)  explain why it is necessary to \ufb01 lter.   . .  [1]  (iii)  why partially evaporate rather than evaporate to dryness?   . ...   . .  [1]  (iv)  what additional steps are needed to obtain dry crystals?   . ...   . .  [2]  (b)  potassium chloride can be made from hydrochloric acid and potassium carbonate.  (i)  why must a different experimental method be used for this preparation?   . ...   . .  [1]  (ii)  give a description of the different method used for this salt preparation.   . ...   . ...   . ...   . .  [4]",
            "9": "9 0620/32/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  insoluble salts are made by precipitation. an equation for the preparation of barium  sulfate is given below. bac l 2(aq)  +  mgso4(aq)  \u2192  baso4(s)  +  mgc l 2(aq)   this reaction can be used to \ufb01 nd x in the formula for hydrated magnesium sulfate mgso4.xh2o.   a known mass of hydrated magnesium sulfate, mgso4.xh2o, was dissolved in water.  excess aqueous barium chloride was added. the precipitate of barium sulfate was \ufb01 ltered, washed and dried. finally it was weighed.  mass of hydrated magnesium sulfate = 1.476  g  mass of barium sulfate formed = 1.398  g  the mass of one mole of baso4 = 233  g  the number of moles of baso4 formed = ... [1]  the number of moles of mgso4.xh2o = ... [1]  the mass of one mole of mgso4.xh2o = ...  g [1]  the mass of one mole of mgso4 = 120  g  the mass of xh2o in one mole of mgso4.xh2o = ... [1]  x = ... [1] [total: 15]",
            "10": "10 0620/32/o/n/11 \u00a9 ucles 2011for examiner\u2019s use7  petrol is  a mixture of hydrocarbons and additives. the combustion of petrol in car engines is  a major source of air pollution. this is reduced by catalytic converters.  (a)  petrol is obtained from the gasoline fraction, boiling point range 40  \u00b0c to 100  \u00b0c, from the  distillation of petroleum. explain the term fraction .   ...    ... ..  [2]  (b)  in many countries, a lead compound of the type pb(c2h5)n used to be added to petrol to  improve its combustion. after combustion, lead oxide was formed. leaded 98 octane  (i)  octane is a constituent of petrol. write the equation for the complete combustion of  octane.  c8h18  +  ...o2  \u2192  ...  +  ... [2]  (ii)  dibromoethane was added to petrol to remove the lead oxide from inside the engine.   lead bromide was formed which escaped into the environment through the exhaust.   leaded petrol cannot be used with a catalytic converter. give another reason why leaded petrol is no longer used.   . .  [1]  (iii)  what does each of the following tell you about the structure of dibromoethane?  dibromo   ..  eth  . .  ane  ...  [2]  (iv)  what additional information is needed to draw the structural formula of dibromoethane?   . .  [1]",
            "11": "11 0620/32/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (c)  an analysis of the compound, pb(c2h5)n , showed that 0.026 moles of pb was combined  with 0.104 moles of c2h5 groups.   what is the value of n? show how you arrived at your answer.   ...    ... ..  [2]  (d)  some of the pollutants emitted by vehicle exhausts are carbon monoxide, oxides of  nitrogen and unburnt hydrocarbons. explain how the emission of these gases is reduced by a catalytic converter.   ...    ...    ... ..  [3] [total: 13]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/32/o/n/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w11_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) october/november 2011  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib11 11_0620_33/2rp\u00a9 ucles 2011 *1895357616* for examiner\u2019s use 3 4 5 total6 71 2",
            "2": "2 0620/33/o/n/11 \u00a9 ucles 2011for examiner\u2019s use1  use your copy of the periodic table to answer these questions.  (a)  choose an element from the periodic table to match each description.   you may give either the name or the symbol.  (i) it is the most reactive metal.    [1]  (ii)  it is the only non-metal which is a liquid at r.t.p..  .  [1]  (iii)  an isotope of this element is used as a fuel in nuclear reactors.  .  [1]  (iv)  this group vii element is a solid at r.t.p..    [1]  (v)  this element is in group v and period 4.    [1]  (vi)  this unreactive gas is used to \ufb01 ll lamps.  .  [1]  (b)  predict the formula of each of the following compounds.  (i)  germanium oxide  ...  (ii)  tellurium bromide  .  [2]  (c)  give the formula of each of the following ions.  (i) strontium  ... .  (ii)  \ufb02 uoride  .  [2] [total: 10]",
            "3": "3 0620/33/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use2  starch, a complex carbohydrate, is a natural macromolecule or polymer.   it can be formed from its monomer by condensation polymerisation.  (a) (i)   explain the terms:  monomer   ...   . ...  condensation polymerisation  ..   . .  [2]  (ii)  draw the structural formula of starch to include three monomer units.   glucose, the monomer, can be represented as                                . [3]  (b)  starch can be hydrolysed to simple sugars by heating with dilute sulfuric acid or by  warming with a dilute solution of saliva. the reaction can be catalysed by h+ ions from  the acid or by the enzymes in saliva.  (i)  what is an enzyme?   . .  [1]  (ii)  explain why, if the saliva  / starch mixture is heated above 70  \u00b0c, the hydrolysis stops.   . .  [1]  (iii)  the complete acid-catalysed hydrolysis of starch forms only glucose.   the partial acid-catalysed hydrolysis of starch forms a mixture of sugars which includes glucose. describe how you could identify the different sugars in this mixture.   . ...   . ...   . .  [3] [total: 10]ho oh",
            "4": "4 0620/33/o/n/11 \u00a9 ucles 2011for examiner\u2019s use3  fertilisers are used to promote plant growth.   two fertilisers are ammonium phosphate, (nh4)3po4, and calcium dihydrogenphosphate,  ca(h2po4)2.  (a)  describe a test to distinguish between these two fertilisers.  test      ... ..  [2]  result  .. ...   ... ..  [1]  (b)  many fertilisers are manufactured from ammonia. describe how ammonia is made in the  haber process. give the essential conditions and an equation for the process.   ...    ...    ...    ... ..  [4]  (c)  state the essential plant nutrient not supplied by ammonium phosphate.   ... ..  [1]  (d)  the soluble compound, calcium dihydrogenphosphate is made by heating the insoluble  mineral rock phosphate, ca3(po4)2, with sulfuric acid.  (i)  why would rock phosphate not be effective as a fertiliser?   . .  [1]  (ii)  the phosphate ion, po43\u2013, from the rock phosphate is changed into the dihydrogenphosphate ion, h2po4\u2013. po43\u2013  +  2h2so4  \u2192  h2po4\u2013  +  2hso4\u2013   what type of reagent is the phosphate ion? give a reason for your choice.   . ...   . .  [2]  (e)  the extensive use of fertilisers and possibly the effect of acid rain tend to increase the  acidity of the soil. state why it is necessary to control soil acidity and explain how this can be done.   ...    ... ..  [2] [total: 13]",
            "5": "5 0620/33/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use4 (a)  steel rusting is an example of an oxidation reaction.  (i)  de\ufb01 ne the term steel .   . ...   . .  [2]  (ii)  de\ufb01 ne oxidation in terms of electron transfer.   . .  [1]  (b)  a method of preventing steel rusting is sacri \ufb01 cial protection. block of magnesiumconnected electrically to steel pipesteel pipe   give an explanation, in terms of electron transfer, why the steel does not rust.   ...    ... ..  [2]  (c)  another method of preventing steel rusting is cathodic protection. \u2013 +power inert anode titanium rodsteel girder cathode bubbles of hydrogen gassea water  (i)  write an equation for the formation of the gas given off at the steel cathode during  cathodic protection.   . .  [2]  (ii)  give one difference between the two methods.   . ...   . .  [2] [total: 9]",
            "6": "6 0620/33/o/n/11 \u00a9 ucles 2011for examiner\u2019s use5 the reactions in this question are all examples of photochemical reactions.  (a)  explain the phrase photochemical reaction .   ...    ... ..  [2]  (b)  many millions of years ago, the earth\u2019s atmosphere was rich in carbon dioxide and  contained negligible amounts of oxygen. after the appearance of green plant-like bacteria, the proportions of these two gases in the atmosphere changed.  (i)  what are the approximate percentages of these two gases in the atmosphere now?  carbon dioxide =  ..  [1] oxygen =  ..  [1] (ii)  explain how the green plant-like bacteria changed the composition of the atmosphere.   . ...   . ...   . ...   . .  [4]  (c)  the reduction of silver( i) bromide to silver is the basis of \ufb01 lm photography. 2agbr  \u2192  2ag  +  br 2  white black   an opaque object is placed on a piece of paper coated with silver( i) bromide which is  then exposed to a bright light. the light is switched off and the opaque object removed. before exposed to light after exposed to light cardboard removedopaque e.g. thick cardboardpaper coated with silver( i) bromidewhite black   explain how the image is formed.   ...    ...    ... ..  [4] [total: 12]",
            "7": "7 0620/33/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use6  nickel is a transition element.  (a)  predict three  differences in the chemical properties of nickel and barium.   ...    ...    ... ..  [3]  (b)  nickel ores are converted into nickel( ii) oxide. this can be reduced to impure nickel by  heating with carbon.  the nickel is puri \ufb01 ed by the following reversible reaction. ni(s)  +  4co(g)    ni(co)4(g)  nickel carbonyl  (i)  impure nickel is heated at 60  \u00b0c. the forward reaction occurs. ni(s)  +  4co(g)  \u2192  ni(co)4(g)  impure   the nickel carbonyl, a gas, moves into a hotter chamber at 200  \u00b0c. the backward  reaction occurs and the nickel carbonyl decomposes. ni(co)4(g)  \u2192  ni(s)  +  4co(g)  pure  is the forward reaction exothermic or endothermic? give a reason for your answer.  . ...   . ...   . .  [2]  (ii)  explain why the forward reaction is favoured by an increase in pressure.   . ...   . .  [2]  (iii)  suggest what happens to the impurities.   . .  [1]",
            "8": "8 0620/33/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (iv)  suggest another method of re \ufb01 ning nickel. give a brief description of the method  which you have suggested. a labelled diagram is acceptable. [4] [total: 12]",
            "9": "9 0620/33/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use7  the alkenes are a series of unsaturated hydrocarbons. they have the general molecular  formula cnh2n.  (a)  deduce the molecular formula of an alkene which has a relative molecular mass of 126.   show your working.   ...    ... ..  [2]  (b)  the structural formula of propene is drawn below. c h hh ch c hh  (i)  draw a diagram showing the arrangement of the valency electrons in one molecule  of this covalent compound.   use x to represent an electron from an atom of carbon.   use o to represent an electron from an atom of hydrogen. [3]  (ii)  draw the structure of the polymer formed from propene [2]",
            "10": "10 0620/33/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (iii)  bond energy is the amount of energy, in kj, which must be supplied to break one  mole of the bond. bondbond energy in kj  / mol h \u2014 h +436 c  c +610 c \u2014 c +346 c \u2014 h +415   use the data in the table to show that the following reaction is exothermic. c h h h hh ch c+ \u2192 hh c hh hh c hhc hh   . ...   . ...   . .  [3]  (c)  this question is concerned with some of the addition reactions of but-1-ene.  (i)  name the product formed when but-1-ene reacts with water.   . .  [1]  (ii)  complete the equation.  ch3 \u2014 ch2 \u2014 ch   ch2  +  br2  \u2192   .  [2]  (iii)  deduce the formula of the compound which reacts with but-1-ene to form  1-iodobutane.   . .  [1] [total: 14]",
            "11": "11 0620/33/o/n/11blank page \u00a9 ucles 2011",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/33/o/n/11 \u00a9 ucles 2011 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w11_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test october/november 2011  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib11 11_0620_51/2rp\u00a9 ucles 2011 *5913063841* for examiner\u2019s use total1 2",
            "2": "2 0620/51/o/n/11 \u00a9 ucles 2011for examiner\u2019s use1  you are going to investigate what happens when aqueous copper( ii) sulfate reacts with two  different metals, zinc and iron.   read all the instructions below carefully before starting the experiments.  instructions  you are going to carry out two experiments.  (a) experiment 1    use a measuring cylinder to pour 25  cm3 of the aqueous copper( ii) sulfate provided  into the polystyrene cup. put the cup into a 250  cm3 beaker for support. measure the  temperature of the solution and record it in the table below. start the timer and record the temperature every half a minute for one minute.    at exactly 1 minute, add the 5  g of zinc powder provided to the cup and stir the mixture  with the thermometer. measure and record the temperature of the mixture every half minute for an additional three minutes. pour the solution away and rinse the polystyrene cup. time  / min 0.0 0.5 1.0 1.5 2.0 2.5 temperature  / \u00b0c time  / min 3.0 3.5 4.0 temperature  / \u00b0c [3]  (b) experiment 2    repeat experiment 1 using 5  g of the iron powder provided instead of the zinc powder.  record your results in the table below. time  / min 0.0 0.5 1.0 1.5 2.0 2.5 temperature  / \u00b0c time  / min 3.0 3.5 4.0 temperature  / \u00b0c [3]",
            "3": "3 0620/51/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  plot the results of both experiments on the grid below. draw two smooth line graphs.  clearly label your graphs. 0 0.5 1.0 1.5 2.0 time  / min2.5 3.0 3.5 4.080 70605040 30 20 10 0temperature  / \u00b0c [5]  (d)  from your graph, work out the temperature of the reaction mixture in experiment 1 after  1 minute 15 seconds.    show clearly on the graph  how you worked out your answer.   ... ..  [3]  (e)  what type of chemical reaction occurs when zinc and iron react with aqueous copper( ii)  sulfate?   ... ..  [1]",
            "4": "4 0620/51/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (f) (i)   compare the temperature changes in experiments 1 and 2.   . .  [1]  (ii) suggest an explanation for the difference in temperature changes.   . ...   . .  [1]  (g)  explain how the temperature changes would differ in the experiments if 12.5  cm3 of  copper( ii) sulfate solution were used.   ...    ...    ... ..  [2]  (h)  predict the effect of using lumps of zinc in experiment 1. explain your answer.   ...    ... ..  [2] [total: 21]",
            "5": "5 0620/51/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use2 you are provided with three different liquids p, q and r.  p and r are aqueous solutions and q is a pure liquid.  carry out the following tests on p, q and r, recording all of your observations in the table.  conclusions must not be written in the table.  tests observations (a) (i)   add about 1  cm3 of each liquid to  separate test-tubes.  describe the  colour and smell of each liquid.  (ii)   using a teat pipette, add a few drops  of each liquid to separate pieces of universal indicator paper. describe the colour and the ph.p . q . r ... [2] p . q . r ... [2] (b)   to about 2  cm3 of each liquid, add a piece  of magnesium ribbon.  test the gas given off by liquid p.p .   [3]q ...  [1] r ... [1] (c)  to about 2  cm3 of each liquid, add a  marble chip.  p ...  [1] q ...  [1] r ...  [1] (d)  to about 5  cm3 of liquid p add a spatula  measure of copper oxide. heat the mixture to boiling. leave to settle for 1 minute.   decant off the liquid and add 1  cm3 of  dilute nitric acid and 1  cm3 of aqueous  barium nitrate to this liquid  [1] ...  [1] (e)  add about 2  cm3 of liquid q to a boiling  tube. heat the liquid to boiling and use a thermometer to record the constant temperature of the vapour  produced just  above the surface of the liquid. temperature .. \u00b0c [1]",
            "6": "6 0620/51/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (f)  identify liquid p.   ... ..  [2]  (g)  identify liquid q.   ... ..  [1]  (h)  what conclusion can you draw about liquid r?   ... ..  [1] [total: 19]",
            "7": "7 0620/51/o/n/11blank page \u00a9 ucles 2011",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/51/o/n/11notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2011"
        },
        "0620_w11_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test october/november 2011  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 6 printed pages and 2 blank pages. [turn overib11 11_0620_52/2rp\u00a9 ucles 2011 *4238227109* for examiner\u2019s use total1 2",
            "2": "2 0620/52/o/n/11 \u00a9 ucles 2011for examiner\u2019s use1  you are going to investigate what happens when iodine reacts with two different solutions of  sodium thiosulfate, f and g.  read all the instructions below carefully before starting the experiments.  instructions  you are going to carry out two experiments.  (a) experiment 1   fill the burette with the aqueous sodium thiosulfate f provided to the 0.0  cm3 mark.    using a measuring cylinder, pour 20  cm3 of the aqueous potassium iodate into a conical  \ufb02 ask. add 1  g of potassium iodide (an excess) and 5  cm3 of the dilute sulfuric acid provided  to the \ufb02 ask and shake the mixture. these chemicals react to form iodine.    add the sodium thiosulfate from the burette 1  cm3 at a time while shaking the \ufb02 ask. when  the colour of the mixture is pale yellow add 2  cm3 of starch solution to the \ufb02 ask. continue  to add sodium thiosulfate solution until the colour changes. record, in the table, the  volume of sodium thiosulfate solution added. \ufb01 nal volume  / cm3 initial volume  / cm3 difference  / cm3 [3]  (b) experiment 2    empty the burette and rinse with the solution g of sodium thiosulfate.    fill the burette with the aqueous sodium thiosulfate g to the 0.0  cm3 mark.    empty the conical \ufb02 ask and rinse it with distilled water.    repeat experiment 1 using solution g instead of solution f.    record, in the table, the volume of sodium thiosulfate solution added. \ufb01 nal volume  / cm3 initial volume  / cm3 difference  / cm3 [3]  (c)  what was the colour of the mixture in the \ufb02 ask before the sodium thiosulfate solution  was added?   ... ..  [1]  (d)  the \ufb01 nal volume reading was taken when the colour of the mixture in the \ufb02 ask changed   from \u2026\u2026\u2026\u2026\u2026.\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026  to \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026..\u2026 [2]",
            "3": "3 0620/52/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (e)  suggest the purpose of the starch in the experiments.   ... ..  [1]  (f) (i)   in which experiment was the greater volume of sodium thiosulfate solution used?   . .  [1]  (ii)  compare the volumes of sodium thiosulfate solution used in experiments 1 and 2.   . .  [1]  (iii)  suggest an explanation for the difference in volumes.   . ...   . ...   . .  [2]  (g)  if experiment 1 was repeated using 10  cm3 of aqueous potassium iodate, what volume of  solution f would be used? explain your answer.   ...    ... ..  [2]  (h) (i)  state two sources of error in the experiments.  1.  .. ..  2.  ..   [2]  (ii) suggest two improvements to reduce the sources of error in the experiments.  1.  .. ..  2.  ..   [2] [total: 20]",
            "4": "4 0620/52/o/n/11 \u00a9 ucles 2011for examiner\u2019s use2 you are provided with two different liquids, h and j.   carry out the following tests on each liquid, recording all of your observations in the table.   conclusions must not be written in the table. tests observations (a) (i)   pour 1  cm3 of liquid h into a test-tube.  describe the appearance and smell of  liquid h.   test the ph of liquid h.  (ii)   pour 1  cm3 of liquid j into a test-tube.  describe the colour and smell ofliquid j.    add 1  cm3 of distilled water to the test-tube and shake the contents. insert a piece of ph indicator paper so that it touches the bottom of thetest-tube.  [1]   [1]   [2] . ...  [2] (b)   to about 1  cm3 of liquid h add about 1 cm3 of dilute hydrochloric acid and then  aqueous barium chloride.   [1] (c) (i)   to about 1  cm3 of liquid h, add about 1 cm3 of aqueous sodium hydroxide.    heat the mixture gently until no further  change is observed.  (ii)   to about 1  cm3 of liquid h, add about 1 cm3 of aqueous ammonia solution.    now add excess aqueous ammonia solution.  [2]   [1] . ...  [3] (d) (i)   using a teat pipette, transfer a few  drops of liquid h to a dry watch glass.   touch the liquid with a lighted splint.  (ii)   repeat test (d)(i)  using liquid j.  [1]   [2]",
            "5": "5 0620/52/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (e) what conclusions can you draw about liquid h?   ...    ... ..  [2]  (f) what conclusions can you draw about liquid j?   ...    ...    ... ..  [2] [total: 20]",
            "6": "6 0620/52/o/n/11blank page \u00a9 ucles 2011",
            "7": "7 0620/52/o/n/11blank page \u00a9 ucles 2011",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/52/o/n/11notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2011"
        },
        "0620_w11_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test october/november 2011  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 6 printed pages and 2 blank pages. [turn overib11 11_0620_53/2rp\u00a9 ucles 2011 *0637573378* for examiner\u2019s use total1 2",
            "2": "2 0620/53/o/n/11 \u00a9 ucles 2011for examiner\u2019s use1  you are going to investigate the reaction between dilute sulfuric acid and three aqueous  solutions of sodium hydroxide of different concentrations, labelled a, b and c.  read all the instructions below carefully before starting the experiments.  instructions  you are going to carry out three experiments.  (a) experiment 1     fill the burette with the dilute sulfuric acid provided to the 0.0  cm3 mark.   use a measuring cylinder to pour 20  cm3 of solution a into a conical \ufb02 ask. add a few  drops of phenolphthalein indicator to the \ufb02 ask.   add the sulfuric acid from the burette 1  cm3 at a time, while shaking the \ufb02 ask, until the  colour of the phenolphthalein changes. record the burette readings in the table.  (b) experiment 2   fill the burette with dilute sulfuric acid to the 0.0  cm3 mark.   empty the conical \ufb02 ask and rinse it with water. use a measuring cylinder to pour 20  cm3  of solution b into the conical \ufb02 ask. add a few drops of phenolphthalein to the \ufb02 ask.   add the sulfuric acid from the burette 1  cm3 at a time, while shaking the \ufb02 ask, until the  colour of the phenolphthalein changes. record the burette readings in the table.  (c) experiment 3    repeat experiment 2, using solution c instead of solution b. record your burette  readings in the table and complete the table. experiment 1 experiment 2 experiment 3 \ufb01 nal reading  / cm3 initial reading  / cm3 difference  / cm3 [6]  (d) what colour change was observed after the sulfuric acid was added to the \ufb02 ask?  from  to . ... [2]  (e)  what type of chemical reaction occurs when sulfuric acid reacts with sodium  hydroxide?   ... ..  [1]",
            "3": "3 0620/53/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (f) (i)   complete the sentences below.   aqueous sodium hydroxide labelled .. needed the smallest volume of  sulfuric acid to change the colour of the phenolphthalein.   aqueous sodium hydroxide labelled .. needed the largest volume of  sulfuric acid to change the colour of the phenolphthalein. [1]  (ii)  the order of concentration of the solutions of sodium hydroxide is  least concentrated . \u2193 .  most concentrated . [2]  (g)  compare the volumes of sulfuric acid used in experiments 1 and 2.   ... ..  [1]  (h)  if experiment 3 was repeated using 40  cm3 of solution c, what volume of sulfuric acid  would be used?    ... ..  [2]  (i)  what would be a more accurate method of measuring the volume of the aqueous sodium  hydroxide?   ... ..  [1]  (j)  what would be the effect on the results if the solutions of sodium hydroxide were warmed  before adding the sulfuric acid? give a reason for your answer.  effect on results  ... .  reason  .  [2]  (k)  suggest a different method of \ufb01 nding the order of concentrations of the solutions of  sodium hydroxide.    ...    ...    ...    ...    ... ..  [3] [total: 21]",
            "4": "4 0620/53/o/n/11 \u00a9 ucles 2011for examiner\u2019s use2  you are provided with two different salts, d and e.  d is an aqueous solution of the salt and e is a solid.   carry out the following tests on each salt, recording all of your observations in the table.   conclusions must not be written in the table. tests observations (a) describe the appearance of  (i)   solution d,  (ii) solid e.  [1]   [1] tests on solution d (b)   divide the solution into \ufb01 ve equal portions  in test-tubes, and carry out the following tests.  (i)  add about 1  cm3 of dilute nitric acid  to the \ufb01 rst portion of the solution and  then aqueous barium nitrate.  (ii)   to the second portion of the solution,  add about 1  cm3  of dilute nitric acid  and aqueous silver nitrate.  (iii)   to the third portion of the solution,  add an excess of aqueous sodium hydroxide.  (iv)  add an excess of aqueous ammonia  solution to the fourth portion.    keep the remaining portion of the  solution for use in test (c)(ii) .  [1]   [2]   [2]   [1] tests on solid e (c) (i)   place about half of solid e in a test-tube. heat the test-tube gently, then strongly. test any gas given off.    leave the test-tube to cool for \ufb01 ve  minutes. then add about 1  cm3 of  dilute nitric acid to the test-tube.  (ii)   add the rest of solid e to the remaining  portion of solution d in a test-tube.. ...  [3] ...  [1] ...  [1]",
            "5": "5 0620/53/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (d)  identify salt d.   ... ..  [3]  (e)  identify the gas given off in test (c)(i) .   ... ..  [1]  (f)  what conclusions can you draw about solid e?   ...    ... ..  [2] [total: 19]",
            "6": "6 0620/53/o/n/11blank page \u00a9 ucles 2011",
            "7": "7 0620/53/o/n/11blank page \u00a9 ucles 2011",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/53/o/n/11notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2011"
        },
        "0620_w11_qp_61.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical october/november 2011  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib11 11_0620_61/3rp\u00a9 ucles 2011 *2666903188* for examiner\u2019s use 3 4 5 total612",
            "2": "2 0620/61/o/n/11blank page \u00a9 ucles 2011",
            "3": "3 0620/61/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use1  a student investigated the reaction of air with copper. 100  cm3 of air was passed continuously  over heated copper using the apparatus below. when the volume remained constant, the  apparatus was left to cool and the volume of gas was measured. copper air  (a) (i)   complete the box to show the apparatus labelled. [1]  (ii)  indicate on the diagram, with an arrow, where heat is applied. [1]  (b)  what should be used to transfer the copper from a bottle to the apparatus?   ... ..  [1]  (c)  the copper changed colour from brown to . [1]  (d)  why was the apparatus left to cool before measuring the \ufb01 nal volume of gas?   ...    ... ..  [2] [total: 6]",
            "4": "4 0620/61/o/n/11 \u00a9 ucles 2011for examiner\u2019s use2  a student prepared a sample of potassium nitrate by neutralising nitric acid using potassium  hydroxide solution.   25.0  cm3 of nitric acid was poured into a conical \ufb02 ask. potassium hydroxide was added a little  at a time from a burette as shown below. potassium hydroxide solution nitric acid   after each addition of potassium hydroxide solution the ph was measured with a ph meter and the values recorded in the table of results. volume of potassium hydroxide solution added  / cm3 ph value 5.0 1.2 10.0 1.4 15.0 2.620.0 2.024.0 2.724.5 3.025.5 11.026.0 11.330.0 12.040.0 13.2   you are going to draw a graph to \ufb01 nd the volume of potassium hydroxide solution required to  neutralise the 25.0  cm3 of nitric acid.",
            "5": "5 0620/61/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (a)  plot the results on the grid below and draw a smooth line graph. 14 1210 86420 0 5 10 15 20 volume of potassium hydroxide solution added  / cm325 30 35 40ph [3]  (b)  which point appears to be inaccurate?   ... ..  [1]  (c) (i)   use your graph  to \ufb01 nd the ph of the solution when 35.0  cm3 of potassium hydroxide  was added.   . .  [1]  (ii)  use your graph  to \ufb01 nd the ph of 25.0  cm3 of nitric acid.   show clearly on the grid  how you obtained your answer.   . .  [2]",
            "6": "6 0620/61/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (d) (i)   what is the ph of the solution when all of the nitric acid has just been neutralised?   . .  [1]  (ii)  what volume of potassium hydroxide was required to neutralise 25.0  cm3 of nitric  acid?   . .  [1]  (e)  describe how the student should modify the experiment to obtain pure crystals of  potassium nitrate.   ...    ...    ...    ...    ... ..  [3] [total: 12]",
            "7": "7 0620/61/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use3  the diagram shows the results of an experiment to separate and identify the colours present  in two coloured mixtures, a and b.   substances c, d, e and f are single colours. a b c d e fsolvent front origin  (a) name this method of separation.   ... ..  [1]  (b)  draw a line on the diagram  to show the level of the solvent at the beginning of the  experiment. [1]  (c)  why should a pencil be used instead of a pen to draw the origin line?   ...    ... ..  [1]  (d)  state one difference and one similarity between the coloured mixtures, a and b.  difference  ..    ...   similarity     ... ..  [2]  (e)  which substances are present in mixture a?   ... ... [1] [total: 6]",
            "8": "8 0620/61/o/n/11 \u00a9 ucles 2011for examiner\u2019s use4  a student investigated the reaction between aqueous copper( ii) sulfate and two different  metals, zinc and iron.   two experiments were carried out.   experiment 1   using a measuring cylinder, 25  cm3 of aqueous copper( ii) sulfate was poured into a  polystyrene cup. the temperature of the solution was measured. the timer was started and  the temperature was measured every half a minute for one minute.   at 1 minute, 5  g of zinc powder was added to the cup and the mixture stirred with the  thermometer. the temperature of the mixture was measured every half minute for an additional three minutes. ",
            "9": "9 0620/61/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (a)   use the thermometer diagrams in the table to record the temperatures. time  / min 0.0 0.51.01.52.0thermometer diagrams temperature  / \u00b0c 2.53.03.54.025 20 15 25 20 15 25 20 15 35 30 25 45 40 35 45 40 35 45 40 35 50 45 40 50 45 40 [3]",
            "10": "10 0620/61/o/n/11 \u00a9 ucles 2011for examiner\u2019s use experiment 2   experiment 1 was repeated using 5  g of iron powder instead of the zinc powder.  (b)  use the thermometer diagrams in the table to record the temperatures. time  / min 0.0 0.51.01.52.0thermometer diagrams temperature  / \u00b0c 2.53.03.54.025 20 15 25 20 15 25 20 15 30 25 20 35 30 25 40 35 30 40 35 30 40 35 30 40 35 30 [3]",
            "11": "11 0620/61/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  plot the results of both experiments on the grid below. draw two smooth line graphs.   clearly label your graphs. 60 5040302010 0 0.0 0.5 1.0 1.5 2.0 time  / min2.5 3.0 3.5 4.0temperature  / \u00b0c [5]  (d)  from your graph , work out the temperature of the reaction mixture in experiment 1 after  1 minute 15 seconds. show clearly on the graph  how you worked out your answer.   ... ..  [3]  (e)  what type of chemical process occurs when zinc and iron react with aqueous copper( ii)  sulfate?   ... ..  [1]",
            "12": "12 0620/61/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (f) (i)   compare the temperature changes in experiments 1 and 2.   . .  [1]  (ii)  suggest an explanation for the difference in temperature changes.   . ...   . .  [1]  (g)  explain how the temperature changes would differ in the experiments if 12.5  cm3 of  copper( ii) sulfate solution were used.   ...    ...    ... ..  [2]  (h) predict the effect of using lumps of zinc in experiment 1. explain your answer.   ...    ... ..  [2] [total: 21]",
            "13": "13 0620/61/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use5 three different liquids p, q and r were analysed.  p was an aqueous solution of sulfuric acid.  the tests on the liquids and some of the observations are in the following table. complete the observations in the table.  tests observations (a) (i)   appearance of the liquids.  (ii)   the ph of the liquids was tested using  universal indicator paper.p ... [1] q colourless, smell of vinegar r colourless, no smell p ... [1] q ph  5 r ph  7 (b)   a piece of magnesium ribbon was added  to a little of each liquid.  the gas given off by liquid p was tested.p . ... [2]q slow effervescence r no reaction (c)  to a little of liquid p, hydrochloric acid and  aqueous barium chloride were added. ...  [2] (d)  liquid r was heated to boiling in a test-tube. a thermometer was used to record the constant temperature of the vapour produced. temperature = 100  \u00b0c  (e)  what conclusions can you draw about liquid q?   ... ..  [2]  (f)  identify liquid r.   ... ..  [1] [total: 9]",
            "14": "14 0620/61/o/n/11 \u00a9 ucles 2011for examiner\u2019s use6  seawater contains sodium chloride and other salts.   plan an experiment to \ufb01 nd the mass of salts in 1  dm3 of seawater.   you will be provided with a small bottle of seawater.   you should include details of the method and any apparatus used.   (1 dm3 = 1000  cm3)   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [6] [total: 6]",
            "15": "15 0620/61/o/n/11blank page \u00a9 ucles 2011",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/61/o/n/11blank page \u00a9 ucles 2011"
        },
        "0620_w11_qp_62.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical october/november 2011  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib11 11_0620_62/3rp\u00a9 ucles 2011 *8480914510* for examiner\u2019s use 3 4 5 total612",
            "2": "2 0620/62/o/n/11blank page \u00a9 ucles 2011",
            "3": "3 0620/62/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use1  a student reacted steam with heated magnesium ribbon using the apparatus below.   a white solid was left in the boiling tube and hydrogen gas was collected. waterwet mineral woolmagnesium hydrogen gas  (a) (i)   complete the box to show the chemical used. [1]  (ii)  indicate on the diagram, with two arrows, where heat is applied. [1]  (b)  suggest the name of the white solid.   ... ..  [1]  (c)  state a test for hydrogen.  test     result  .. .  [2]  (d)  suggest why the boiling tube containing the magnesium often cracks on cooling.   ... ..  [1] [total: 6]",
            "4": "4 0620/62/o/n/11 \u00a9 ucles 2011for examiner\u2019s use2  a student carried out an experiment to investigate the speed of reaction between 50  cm3 of  dilute hydrochloric acid and excess zinc powder using the apparatus shown below.   the reaction was carried out at a room temperature of 25  \u00b0c. dilute hydrochloric acid zinc powdergas syringe   (a)  the volume of gas produced was measured every minute for six minutes.   use the syringe diagrams to complete the table of results. time  / minutes gas syringe diagram volume of gas collected  / cm3 01 02 03 0 50 60 400 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 401 2 3 45 6 [3]",
            "5": "5 0620/62/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (b)  plot the results on the grid below and draw a smooth line graph. 60 5040302010 0 0 1 2 3 4 5  6 volume of gas  / cm3 time  / minutes  [4]  (c) (i)   at which time does the result appear to be inaccurate?   . .  [1]  (ii)  use your graph  to work out the volume of gas that should have been recorded at  this time. show clearly on the grid  how you obtained your answer.   . .  [2]  (d) (i)   how does the speed of the reaction change over six minutes?   . .  [1]  (ii) explain why this change in speed takes place.   . ...   . .  [1]",
            "6": "6 0620/62/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (e)  sketch, on the grid , the graph you would expect if the experiment was repeated   (i) at 50  \u00b0c,  (ii) using excess lumps of zinc.   clearly label your sketches. [2] [total: 14]",
            "7": "7 0620/62/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use3  the following account is from a student\u2019s notebook on how she made a sample of hydrated  cobalt( ii) chloride crystals, coc l 2.6h2o.  (a)  why was the acid warmed?   ... ..  [1]  (b)  why did it not matter if the volume of hydrochloric acid was not exactly 40  cm3?   ... ..  [1]  (c)  why was the mixture stirred with a glass rod and not a metal spatula?   ... ..  [1]  (d)  how would the student have known when no more cobalt carbonate reacted?   ... ..  [1]  (e)  how would the student know when the crystallisation point had been reached?   ... ..  [1]  (f)  suggest the effect of heat on hydrated cobalt( ii) chloride crystals.   ...    ... ..  [2] [total: 7]",
            "8": "8 0620/62/o/n/11 \u00a9 ucles 2011for examiner\u2019s use4  a student investigated the reaction of iodine with two different aqueous solutions of sodium  thiosulfate, f and g.  two experiments were carried out. experiment 1  a burette was \ufb01 lled with the aqueous solution of sodium thiosulfate, f, to the 0.0  cm3 mark.   using a measuring cylinder, 20  cm3 of aqueous potassium iodate was poured into a conical  \ufb02 ask. excess potassium iodide and dilute sulfuric acid were added to the \ufb02 ask and the mixture  shaken. these chemicals reacted to form iodine.   the sodium thiosulfate solution was added from the burette 1  cm3 at a time. when the colour  of the mixture was pale yellow, starch solution was added to the \ufb02 ask. sodium thiosulfate  solution was then added until the solution became colourless.   (a)  use the burette diagram to record the volume in the table and complete the column. 22 2324 final reading  experiment 2   the burette was emptied and rinsed with the aqueous solution of sodium thiosulfate, g.   experiment 1 was repeated using the solution g of sodium thiosulfate instead of solution f.  (b)  use the burette diagrams to record the volumes in the table and complete the table. 1 23 initial reading474849 final reading burette readings  / cm3 experiment 1 experiment 2 \ufb01 nal reading initial reading difference [4]",
            "9": "9 0620/62/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (c)  why was the burette rinsed with solution g before carrying out experiment 2?   ... ..  [1]  (d)  suggest the purpose of the starch in the experiments.   ... ..  [1]  (e) (i)   in which experiment was the greater volume of sodium thiosulfate solution used?   . .  [1]  (ii)  compare the volumes of sodium thiosulfate solution used in experiments 1 and 2.   . .  [1]  (iii)  suggest an explanation for the difference in volumes.   . ...   . ...   . .  [2]  (f)  if experiment 1 was repeated using 10  cm3 of aqueous potassium iodate, what volume of  solution f would be used? explain your answer.   ...    ... ..  [2]  (g) (i)  state two sources of error in the experiments.  1.  .. ..  2.  ..   [2]  (ii)  suggest two improvements to reduce the sources of error in the experiments.  1.  .. ..  2.  ..   [2] [total: 16]",
            "10": "10 0620/62/o/n/11 \u00a9 ucles 2011for examiner\u2019s use5 two different liquids, h and j, were analysed.  h was an aqueous solution of copper( ii) sulfate.  the tests on the liquids and some of the observations are in the following table. complete the observations in the table. tests observations (a) (i)   appearance of liquid h.  (ii)   appearance and smell of liquid j.  (iii)   distilled water was added to liquid j in  a test-tube and the contents shaken [1]  distinctive smell  two layers of liquid visible (b)   to liquid h was added dilute hydrochloric  acid and then aqueous barium chloride. ... [2] (c) (i)   to a little of liquid h, excess aqueous  sodium hydroxide was added.  (ii)   to a little of liquid h, about 1  cm3 of  aqueous ammonia solution was added.    excess aqueous ammonia solution  was then added  [2] ...  [3] (d)  a few drops of liquid j were put on a dry  watch glass.   the liquid was touched with a lighted  splint. liquid burns with a sooty \ufb02 ame  (e)  what conclusions can you draw about liquid j?   ...    ... ..  [2] [total: 10]",
            "11": "11 0620/62/o/n/11 \u00a9 ucles 2011for examiner\u2019s use6  kleen up is a colourless liquid used to clean work surfaces and glass windows.   kleen up contains ammonia solution, which is a weak alkali. contains ammoniakleenkleen upupkleenkleen upupkleen up  (a)  state a chemical test to show the presence of ammonia in kleen up.  test     result  .. .  [2]  (b)  plan an experiment to determine the concentration of ammonia in kleen up.   you are provided with aqueous nitric acid of known concentration and common laboratory  apparatus.   ...    ...    ...    ...    ...    ... ..  [5] [total: 7]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/62/o/n/11blank page \u00a9 ucles 2011"
        },
        "0620_w11_qp_63.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical october/november 2011  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib11 11_0620_63/2rp\u00a9 ucles 2011 *4271923629* for examiner\u2019s use 3 4 5 total61 2",
            "2": "2 0620/63/o/n/11blank page \u00a9 ucles 2011",
            "3": "3 0620/63/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use1  three sets of apparatus, a, b and c, are shown below. ab c  (a)  complete the empty boxes to name the pieces of apparatus. [3]  (b)  what name is given to the separation method in a?   ... ..  [1]  (c)  which apparatus would be most suitable to obtain crystals from an aqueous solution of  copper sulfate?   ... ..  [1] [total: 5]",
            "4": "4 0620/63/o/n/11 \u00a9 ucles 2011for examiner\u2019s use2  a student investigated the temperature changes when metals are added to excess dilute  hydrochloric acid using the apparatus shown.  dilute hydrochloric acidmetal   the \ufb01 ve metals used were copper, magnesium, calcium, iron and zinc.   0.5  g of each metal was added to 25  cm3 of hydrochloric acid and the highest temperature  reached was measured.   in each experiment the initial temperature of the acid was 25  \u00b0c.  (a)  use the thermometer diagrams to record the highest temperatures in the table.   complete the table by calculating the temperature rises. metals copper magnesium calcium iron zincthermometer diagrams highest temperature  / \u00b0c temperature rise  / \u00b0c 30 25 20 45 40 35 50 45 40 35 30 25 35 30 25 [4]",
            "5": "5 0620/63/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use (b)  draw a labelled bar chart to show the results of the experiments. temperature rise  / \u00b0c [4]  (c) (i)   which metal reacted with the hydrochloric acid to produce the largest temperature  rise?   . .  [1]  (ii)  state and explain the result obtained for copper.   . ...   . .  [2]  (d)  use the results to place the metals in order of increasing reactivity. least reactive metal most reactive metal [2]  (e)  predict the effect on the temperature changes if the experiments were repeated using  50  cm3 of the dilute hydrochloric acid. explain your answer.   ...    ... ..  [2] [total: 15]",
            "6": "6 0620/63/o/n/11 \u00a9 ucles 2011for examiner\u2019s use3  the solubility of carbon dioxide gas in water varies with temperature.   a student used a data book to plot the solubility of carbon dioxide in water at different  temperatures on the grid below. solubility of carbon dioxide 02 0 4 0 6 0 temperature  / \u00b0c  (a)  draw a smooth curve through the points. [1]  (b)  which point appears to have been incorrectly plotted?   ... ..  [1]  (c)  what is the effect of increasing the temperature on the solubility of carbon dioxide in  water?   ... ..  [1]  (d)  nitrogen is less soluble in water than carbon dioxide. on the grid, sketch a graph to  represent the solubility of nitrogen. [1] [total: 4]",
            "7": "7 0620/63/o/n/11 \u00a9 ucles 2011question 4 starts on the next page.",
            "8": "8 0620/63/o/n/11 \u00a9 ucles 2011for examiner\u2019s use4  a student investigated the reaction between dilute sulfuric acid and three aqueous solutions  of sodium hydroxide of different concentrations, labelled a, b and c.  three experiments were carried out. experiment 1  a burette was \ufb01 lled up to the 0.0  cm3 mark with dilute sulfuric acid.   using a measuring cylinder, 20  cm3 of solution a was poured into a conical \ufb02 ask with a few  drops of phenolphthalein indicator.   the sulfuric acid was added to the \ufb02 ask, until the colour of the phenolphthalein changed.  (a)  use the burette diagram to record the \ufb01 nal volume in the table. 9 1011 final reading  experiment 2   experiment 1 was repeated using solution b.   (b)  use the burette diagrams to record the volumes in the table. 1 23 initial reading222324 final reading  experiment 3   experiment 2 was repeated using solution c instead of solution b.   (c)  use the burette diagrams to record the volumes in the table and complete the table. 10 1112 initial reading151617 final reading",
            "9": "9 0620/63/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s useburette readings  / cm3 experiment 1 experiment 2 experiment 3 \ufb01 nal reading initial reading difference [4]  (d)  what permanent colour change was observed after the sulfuric acid was added to the  \ufb02 ask?  from .. to .. [2]  (e)  what type of chemical reaction occurs when sulfuric acid reacts with sodium hydroxide?   ... ..  [1]  (f) (i)  complete the sentences below.   aqueous sodium hydroxide labelled .. needed the smallest volume  of sulfuric acid to change the colour of the phenolphthalein.   aqueous sodium hydroxide labelled .. needed the largest volume  of sulfuric acid to change the colour of the phenolphthalein. [1]  (ii)  the order of concentration of the solutions of sodium hydroxide is least concentrated most concentrated [2]  (g)  compare the volumes of sulfuric acid used in experiments 1 and 2.   ... ..  [1]  (h)  if experiment 3 was repeated using 40  cm3 of solution c, what volume of sulfuric acid  would be used?    ... ..  [2]  (i)  what would be a more accurate method of measuring the volume of the aqueous sodium  hydroxide?   ... ..  [1]",
            "10": "10 0620/63/o/n/11 \u00a9 ucles 2011for examiner\u2019s use (j)  what would be the effect on the results if the solutions of sodium hydroxide were warmed  before adding the sulfuric acid? give a reason for your answer.  effect on results  ... .  reason  .  [2]  (k)  suggest a different  method of \ufb01 nding the order of concentrations of the solutions of  sodium hydroxide.    ...    ...    ...    ...    ... ..  [3] [total: 19]",
            "11": "11 0620/63/o/n/11 \u00a9 ucles 2011 [turn overfor examiner\u2019s use5 two different salts, d and e, were analysed.  d was an aqueous solution of iron( iii) chloride and e was a solid.  the tests on the salts and some of the observations are in the following table. complete the observations in the table. tests observations (a) (i)   appearance of solution d.  (ii)   appearance of solid e [1]  white crystals tests on solution d (b)  the solution was divided into four equal  portions in test-tubes, and the following tests carried out.  (i)   dilute hydrochloric acid was added  to the \ufb01 rst portion of the solution and  then aqueous barium chloride.  (ii)   dilute nitric acid was added to the  second portion and then aqueous silver nitrate.  (iii)   an excess of aqueous sodium  hydroxide was added to the third portion of the solution.  (iv)   an excess of aqueous ammonia was  added to the fourth portion [1] ... [2]... [2] ... [1] tests on solid e (c) (i)   solid e was heated in a test-tube.    the gas given off was tested.  (ii)   dilute nitric acid was added to solid e  in a test-tube. limewater turned milky  rapid effervescence,  limewater turned milky  (d)  identify the gas given off in tests (c)(i)  and (c)(ii) .   ... ..  [1]  (e)  what conclusions can you draw about solid e?   ...    ... ..  [2] [total: 10]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/63/o/n/11 \u00a9 ucles 2011for examiner\u2019s use6 the label on an aerosol can of kleen air air freshener is shown. kleenkleen airairkleenkleen airairkleen aircontains: solventsethanolpropanone lemon oil  (a)  what is meant by the term solvent  ?   ... ..  [1]  (b)  what does the hazard sign indicate?   ... ..  [1]  (c)  what method could be used to obtain ethanol (boiling point 78  \u00b0c) from a mixture of  ethanol and propanone (boiling point 56  \u00b0c)?   ... ..  [1]  (d)  describe an experiment to investigate the number of coloured substances present in a  sample of the lemon oil obtained from kleen air.   ...    ...    ...    ...    ...    ... ..  [4] [total: 7]"
        }
    },
    "2012": {
        "0620_s12_qp_11.pdf": {
            "1": "    this document consists of 16 printed pages.  ib12 06_0620_11/3rp  \u00a9 ucles 2012  [turn over       *3111298563* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  may/june 2012       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2012 0620/11/m/j/12  1 which diagram shows the process of diffusion?    a b c ddifferent atomskey       2 which method is most suitable to obtain zinc carbonate from a suspension of zinc carbonate in  water?  a crystallisation  b distillation  c evaporation  d filtration      3 a student investigates how the concentration of an acid affects the speed of reaction with a 0.5  g  mass of magnesium at 30  \u00b0c.    the student has a beaker, concentrated acid, water and the apparatus below.    p a balance  q a clock r a measuring cylinder s a thermometer    which pieces of apparatus does the student use?  a p, q and r only  b p, q and s only  c q, r and s only  d p, q, r and s     ",
            "3": "3  \u00a9 ucles 2012 0620/11/m/j/12 [turn over  4 an element y has the proton number 18.    the next element in the periodic table is an element z.    which statement is correct?  a element z has one more electron in its outer shell than element y.  b element z has one more electron shell than element y.  c element z is in the same group of the periodic table as element y.  d element z is in the same period of the periodic table as element y.     5 which atom has twice as many neutrons as protons?  a  h1 1 b h2 1 c h3 1 d he4 2     6 which is a simple covalent molecule?    conducts electricity    when solid when molten volatile  a \u0013 \u0013 \u0017  b \u0013 \u0017 \u0013  c \u0017 \u0013 \u0017  d \u0017 \u0017 \u0013    7 the electronic structures of atoms p and q are shown.    q p= electron key      p and q react to form an ionic compound.    what is the formula of this compound?  a pq 2 b p2q c p2q6 d p6q2    ",
            "4": "4  \u00a9 ucles 2012 0620/11/m/j/12  8 the diagrams show the structures of two forms, p and q, of a solid element.    pq     what are suitable uses of p and q, based on their structures?     use of solid p use of solid q  a drilling drilling  b lubricating drilling  c drilling lubricating  d lubricating lubricating     9 the equation for the reaction between magnesium and dilute sulfuric acid is shown.    mg  +  h 2so 4  \u2192  mgso 4  +  h 2   m r of mgso 4 is 120    which mass of magnesium sulfate will be formed if 12  g of magnesium are reacted with sulfuric  acid?  a 5  g b 10  g c 60  g d 120  g    ",
            "5": "5  \u00a9 ucles 2012 0620/11/m/j/12 [turn over  10 winston churchill, a british prime minister, had his false teeth electroplated with gold.    the teeth were coated with a thin layer of car bon and were then placed in the apparatus shown.    false teethswitch gold aqueous solution of a gold saltxy     which row is correct?     terminal x is the carbon powder  could be  a negative diamond  b negative graphite  c positive diamond  d positive graphite     ",
            "6": "6  \u00a9 ucles 2012 0620/11/m/j/12  11 the diagram shows that two gases are formed when concentrated hydrochloric acid is  electrolysed using inert electrodes.    +ve \u2013ve concentrated hydrochloric acid     which row correctly describes the colours of the gases at the electrodes?     anode (+ve) cathode (\u2013ve)  a colourless colourless  b colourless yellow-green  c yellow-green colourless  d yellow-green yellow-green      12 the diagram shows the reaction between zinc oxide and dilute hydrochloric acid.    dilute hydrochloric acid 20  \u00b0c ph  1aqueous zinc chloride22  \u00b0c ph  7 before afterzinc oxide powder     which terms describe the reaction?     endothermic neutralisation  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017   ",
            "7": "7  \u00a9 ucles 2012 0620/11/m/j/12 [turn over  13 the apparatus shown is used to measure the speed of a reaction.    gas syringe reactants     which equation represents a reaction where the speed can be measured using this apparatus?  a mg(s)  +  2hc l (aq)  \u2192  mgc l 2(aq)  +  h 2(g)  b hc l (aq)  +  naoh(aq)  \u2192  nac l (aq)  +  h 2o(l)  c fe(s)  +  cuso 4(aq)  \u2192  cu(s)  +  feso 4(aq)  d 2na(s)  +  br 2(l)  \u2192  2nabr(s)     14 the element vanadium, v, forms several oxides.    in which change is oxidation taking place?  a vo 2 \u2192 v 2o3  b v2o5 \u2192 vo 2  c v2o3 \u2192 vo  d v2o3 \u2192 v 2o5      15 a gas is escaping from a pipe in a chemical plant.    a chemist tests this gas and finds that it is alkaline.    what is this gas?  a ammonia  b chlorine  c hydrogen  d sulfur dioxide      ",
            "8": "8  \u00a9 ucles 2012 0620/11/m/j/12  16 the results of three tests on a solution of compound x are shown in the table.    test result  aqueous sodium hydroxide added white precipitate formed, soluble in excess  aqueous ammonia added white precipitate formed, insoluble in excess  acidified silver nitrate added white precipitate formed    what is compound x?  a aluminium bromide  b aluminium chloride  c zinc bromide  d zinc chloride     17 the graph shows how the ph changes as an acid is added to an alkali.    acid  +  alkali  \u2192  salt  +  water    which letter represents the area of the graph where both acid and salt are present?    pha b c d14 7 0      18 dilute hydrochloric acid is added to a solid, s.    a flammable gas, g, is formed. gas g is less dense than air.    what are s and g?     solid s gas g  a copper hydrogen  b copper carbonate carbon dioxide  c zinc hydrogen  d zinc carbonate carbon dioxide     ",
            "9": "9  \u00a9 ucles 2012 0620/11/m/j/12 [turn over  19 the diagram shows a section of the periodic table.    which element is described below?    \u2018a colourless, unreactive gas that is denser than air.\u2019    a b c d      20 element x is below iodine in the periodic table.    which row correctly shows the physical state of element x at room temperature and its reactivity compared with that of iodine?     physical state  of element x at  room temperature reactivity compared  with that of iodine  a gas less reactive  b solid less reactive  c gas more reactive  d solid more reactive    21 which properties of the element titanium, ti, can be predicted from its position in the periodic  table?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0013 \u0013 \u0017 \u0013  b \u0013 \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013 \u0013  d \u0017 \u0013 \u0013 \u0013    ",
            "10": "10  \u00a9 ucles 2012 0620/11/m/j/12  22 five elements have proton numbers 10, 12, 14, 16 and 18.    what are the proton numbers of the three elements that form oxides?  a 10, 12 and 14  b 10, 14 and 18  c 12, 14 and 16  d 14, 16 and 18     23 which statement about the uses of metals is correct?  a aluminium is used in the manufacture of aircraft as it has a high density.  b aluminium is used to make food containers as it conducts electricity.  c stainless steel for cutlery is made by adding other elements to iron.  d stainless steel is used to make chemical reactors as it corrodes readily.    24 which statement about the extraction of iron from its ore is correct?  a iron is more difficult to extract than zinc.  b iron is more difficult to extract than copper.  c iron is easy to extract because it is a transition metal.  d iron cannot be extracted by reduction with carbon.    25 metal x reacts violently with water.    metal y reacts slowly with steam.    metal z does not react with dilute hydrochloric acid.    what is the correct order of reactivity of these metals, most reactive first?  a x \u2192 y \u2192 z  b x \u2192 z \u2192 y  c z \u2192 x \u2192 y  d z \u2192 y \u2192 x      26 which property is shown by all metals?  a they are extracted from their ores by heating with carbon.  b they conduct electricity.  c they form acidic oxides.  d they react with hydrochloric acid to form hydrogen. ",
            "11": "11  \u00a9 ucles 2012 0620/11/m/j/12 [turn over  27 some uses of water are listed.    1 for drinking  2 in chemical reactions  3 in swimming pools  4 in washing    for which uses is it necessary to chlorinate the water?  a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      28 coal is a fossil fuel.    which gas is not formed when coal burns?  a carbon dioxide  b carbon monoxide  c methane  d sulfur dioxide     29 which is a use of oxygen?  a filling balloons  b filling light bulbs  c food preservation  d making steel    30 fertilisers need to supply crops with three main elements.    which compound contains all three of these elements?  a h 3po 4 b kno 3 c nh 4k2po 4 d nh 4no 3     ",
            "12": "12  \u00a9 ucles 2012 0620/11/m/j/12  31 a new planet has been discovered a nd its atmosphere has been analysed.    atmosphere planet     the table shows the composition of the atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only     32 gas x is a waste gas from digestion in animals.    gas y is formed when gas x is burnt with a small amount of oxygen.    gas z is formed when gas x is burnt with an excess of oxygen.    what are x, y and z?     x y z  a carbon dioxide methane carbon monoxide  b carbon monoxide methane carbon dioxide  c methane carbon dioxide carbon monoxide  d methane carbon monoxide carbon dioxide    ",
            "13": "13  \u00a9 ucles 2012 0620/11/m/j/12 [turn over  33 air containing an acidic impurity was neutralised by passing it through a column containing  substance x.    acidic air neutralised ai rsubstance x     what is substance x?  a calcium oxide  b sand  c sodium chloride  d concentrated sulfuric acid     34 the structure of a compound is shown.    ch co ohh h hc c h     which functional groups are present in this compound?     alcohol alkene carboxylic acid  a \u0013 \u0013 \u0013  b \u0013 \u0017 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0017 \u0013     35 which fraction from the fractional distillation of petroleum does not match its correct use?     fraction use  a fuel oil domestic heating  b kerosene jet fuel  c naphtha making roads  d refinery gas for heating and cooking    ",
            "14": "14  \u00a9 ucles 2012 0620/11/m/j/12  36 the diagram shows apparatus used to separate petroleum into four fractions.    petroleum on rock wool heatthermometer water fraction    which fraction contains the smallest hydrocarbon molecules?    fraction boiling point range  / \u00b0c  a up to 70  b 70 to 120  c 120 to 170  d over 170      37 when a long chain hydrocarbon is cracked, the following products are produced.    1 c 3h8  2 c 2h4  3 c 3h6  4 c 2h6    which products would decolourise bromine water?  a 1 and 4 b 2 and 3 c 2 only d 3 only     ",
            "15": "15  \u00a9 ucles 2012 0620/11/m/j/12  38 pva is a polymer. the monomer has the structure shown.    c coh hh h    to which homologous series does this compound belong?     alcohols alkenes  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     39 which equation represents incomplete combustion of ethane?  a c 2h6  +  o 2  \u2192  2co  +  3h 2  b c 2h6  +  2o 2  \u2192  2co 2  +  3h 2  c 2c 2h6  +  5o 2  \u2192  4co  +  6h 2o  d 2c 2h6  +  7o 2  \u2192  4co 2  +  6h 2o    40 ethanol is an important chemical produced by the  \u2026\u20261\u2026\u2026  of  \u2026\u20262\u2026\u2026 .    which words correctly complete gaps 1 and 2?     1 2  a combustion ethane  b combustion glucose  c fermentation ethane  d fermentation glucose    ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2012 0620/11/m/j/12   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s12_qp_12.pdf": {
            "1": "    this document consists of 16 printed pages.  ib12 06_0620_12/3rp  \u00a9 ucles 2012  [turn over       *7216958504* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  may/june 2012       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2012 0620/12/m/j/12  1 which diagram shows the process of diffusion?    a b c ddifferent atomskey       2 which method would be most suitable for the separation of a mixture of sand and water to obtain  the sand?  a chromatography  b crystallisation  c distillation  d filtration      3 a student investigates how the concentration of an acid affects the speed of reaction with a 0.5  g  mass of magnesium at 30  \u00b0c.    the student has a beaker, concentrated acid, water and the apparatus below.    p a balance  q a clock r a measuring cylinder s a thermometer    which pieces of apparatus does the student use?  a p, q and r only  b p, q and s only  c q, r and s only  d p, q, r and s     ",
            "3": "3  \u00a9 ucles 2012 0620/12/m/j/12 [turn over  4 an element y has the proton number 18.    the next element in the periodic table is an element z.    which statement is correct?  a element z has one more electron in its outer shell than element y.  b element z has one more electron shell than element y.  c element z is in the same group of the periodic table as element y.  d element z is in the same period of the periodic table as element y.     5 which atom has twice as many neutrons as protons?  a  h1 1 b h2 1 c h3 1 d he4 2     6 the table contains information about four substances.    which substance is potassium chloride?    conduction of electricity   melting point  / \u00b0c when molten in aqueous solution  a 11 no yes  b 98 yes yes  c 772 yes yes  d 1410 no insoluble      7 the electronic structures of atoms p and q are shown.    q p= electron key      p and q react to form an ionic compound.    what is the formula of this compound?  a pq 2 b p2q c p2q6 d p6q2     ",
            "4": "4  \u00a9 ucles 2012 0620/12/m/j/12  8 the diagrams show the structures of two forms, p and q, of a solid element.    pq     what are suitable uses of p and q, based on their structures?     use of solid p use of solid q  a drilling drilling  b lubricating drilling  c drilling lubricating  d lubricating lubricating     9 methane, ch 4, burns in the air to form carbon dioxide and water.    what is the balanced equation for this reaction?  a ch 4(g)  +  o 2(g)  \u2192  co 2(g)  +  2h 2o(g)  b ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(g)  c ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  h 2o(g)  d ch 4(g)  +  3o 2(g)  \u2192  co 2(g)  +  2h 2o(g)      10 in which reaction is lead( ii) oxide, pbo, oxidised?  a pbo  +  c  \u2192  pb  +  co  b pbo  +  co  \u2192  pb  +  co 2  c pbo  +  h 2  \u2192  pb  +  h 2o  d 2pbo  +  o 2  \u2192  2pbo 2     ",
            "5": "5  \u00a9 ucles 2012 0620/12/m/j/12 [turn over  11 the diagram shows an unsuccessful experiment to nickel plate a pan.    pan nickel sulfate solutionnickel cathode\u2013ve +ve     which change is necessary to plate the pan with nickel?  a add more nickel sulfate to the solution.  b heat the solution to 100  \u00b0c.  c increase the current in the circuit.  d make the pan the negative electrode.     12 the rates of some chemical reactions can be measured by using the apparatus shown.    94.72  g reactants  balance      for which reaction is this apparatus suitable?  a mgco 3  +  2hc l  \u2192  mgc l 2  +  co 2  +  h 2o  b mg  +  znc l 2  \u2192  mgc l 2  +  zn  c mgc l 2  +  2naoh  \u2192  mg(oh) 2  +  2nac l  d mgo  +  2hc l  \u2192  mgc l 2  +  h 2o     ",
            "6": "6  \u00a9 ucles 2012 0620/12/m/j/12  13 the diagram shows that two gases are formed when concentrated hydrochloric acid is  electrolysed using inert electrodes.    +ve \u2013ve concentrated hydrochloric acid     which row correctly describes the colours of the gases at the electrodes?     anode (+ve) cathode (\u2013ve)  a colourless colourless  b colourless yellow-green  c yellow-green colourless  d yellow-green yellow-green      14 the diagram shows the reaction between zinc oxide and dilute hydrochloric acid.    dilute hydrochloric acid 20  \u00b0c ph  1aqueous zinc chloride22  \u00b0c ph  7 before afterzinc oxide powder     which terms describe the reaction?     endothermic neutralisation  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017   ",
            "7": "7  \u00a9 ucles 2012 0620/12/m/j/12 [turn over  15 four different gases are passed through the apparatus shown.    gas in gas out damp red litmus paperdamp blue litmus paper    which gas has no effect on either piece of litmus paper?  a ammonia  b carbon dioxide  c chlorine  d hydrogen      16 an aqueous solution of copper( ii) sulfate was made by adding excess copper( ii) oxide to dilute  sulfuric acid. the mixture was heated, stirred and then filtered.    dilute sulfuric acid copper( ii) oxide heatcopper( ii) sulfate solution     what was the ph of the acid before adding the copper( ii) oxide and of the solution after filtration?     ph of acid before adding  copper( ii) oxide ph of solution  after filtration  a greater than 7 7  b greater than 7 less than 7  c less than 7 7  d less than 7 greater than 7     ",
            "8": "8  \u00a9 ucles 2012 0620/12/m/j/12  17 aqueous potassium iodide is added to aqueous silver nitrate.    what are the colours of the final precipitate and solution?     precipitate solution  a brown colourless  b white yellow  c yellow colourless  d yellow white     18 three gas jars contain carbon dioxide, hydrogen and oxygen, as shown.    carbon dioxide hydrogen oxygen    which one of the following tests could be used to discover which gas is in each jar?  a a glowing splint  b a lighted splint  c damp blue litmus paper  d limewater      19 the diagram shows an outline of part of the periodic table.    x yz     which statement about elements x, y and z is not correct?  a all are metals.  b all conduct electricity.  c all form coloured compounds.  d all react with oxygen.   ",
            "9": "9  \u00a9 ucles 2012 0620/12/m/j/12 [turn over  20 elements x, y and z are in group vii of the periodic table.    x is a gas.    y is less reactive than z    z is a red liquid.    when x, y and z are put in order of increasing proton number, which order is correct?  a x \u2192 y \u2192 z b x \u2192 z \u2192 y c y \u2192 x \u2192 z d y \u2192 z \u2192 x      21 which properties of the element titanium, ti, can be predicted from its position in the periodic  table?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0013 \u0013 \u0017 \u0013  b \u0013 \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013 \u0013  d \u0017 \u0013 \u0013 \u0013     22 five elements have proton numbers 10, 12, 14, 16 and 18.    what are the proton numbers of the three elements that form oxides?  a 10, 12 and 14  b 10, 14 and 18  c 12, 14 and 16  d 14, 16 and 18      23 which statement about aluminium is not correct?  a it is resistant to corrosion.  b it is strong and has a high density.  c it is used in food containers.  d it is used in the manufacture of aircraft.    ",
            "10": "10  \u00a9 ucles 2012 0620/12/m/j/12  24 many metals are extracted from their ores by heating the metal oxide with carbon.    which metal cannot  be extracted using this method?  a aluminium  b copper  c iron  d zinc     25 a metal has the following properties.    \u25cf it does not react with cold water.  \u25cf it reacts with dilute hydrochloric acid.  \u25cf it cannot be extracted from its oxide using carbon.    between which two metals in the reactivity series should it be placed?  a calcium and magnesium  b iron and copper  c magnesium and zinc  d zinc and iron      26 which statements about the general properties of metals are correct?    1 conduct electricity when solid  2 form acidic oxides  3 high melting point    a 1 and 3 b 1 only c 2 and 3 d 2 only      27 water for human use is treated by filtration then chlorination.    which uses do not need water of this quality?    1 water for cooling in industry  2 water for flushing toilets in the home  3 water for drinking    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "11": "11  \u00a9 ucles 2012 0620/12/m/j/12 [turn over  28 carbon monoxide is an air pollutant produced when petrol is burned in a car engine.    why is carbon monoxide considered to be an air pollutant?  a it causes global warming.  b it causes the corrosion of buildings.  c it is a greenhouse gas.  d it is poisonous.     29 a new planet has been discovered a nd its atmosphere has been analysed.    atmosphere planet     the table shows the composition of the atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only    30 acetylene, c 2h2, is a hydrocarbon. when acetylene and oxygen react, the hot flame produced  can be used to weld steel.    which statement is correct?  a acetylene and oxygen react exothermically.  b acetylene is saturated.  c oxygen and steel react endothermically.  d oxygen is a gaseous fuel.     ",
            "12": "12  \u00a9 ucles 2012 0620/12/m/j/12  31 fertilisers are used to provide three elements needed to increase the yield of crops.    which two compounds, when used together, would provide all three of these elements?  a ammonium nitrate and calcium phosphate  b ammonium nitrate and potassium sulfate  c potassium nitrate and calcium phosphate  d potassium nitrate and potassium sulfate     32 carbon dioxide and methane are \u2018greenhouse gases\u2019 which contribute to global warming.    which process does not increase global warming?  a burning fossil fuels  b decay of organic waste  c farming cattle for beef  d growing crops such as sugar cane      33 when coal and oil burn in power stations, the acidic gas sulfur dioxide is formed. sulfur dioxide is  removed by absorbing it in a liquid sprayed down a tower.    towe r waste gases (including sulfur dioxide)liquid x spray      what is liquid x?  a calcium hydroxide solution  b sodium chloride solution  c dilute  hydrochloric acid  d water     ",
            "13": "13  \u00a9 ucles 2012 0620/12/m/j/12 [turn over  34 the table shows bonds that are present a nd bonds that are not present in compound x.    bond   c\u2013c \u0013  c=c \u0017  c\u2013h \u0013  c\u2013o \u0013  c=o \u0013  o\u2013h \u0013    what type of compound is x?  a a carboxylic acid  b an alcohol  c an alkane  d an alkene      35 the diagram shows different fuels from which electricity can be generated.    electricity coaluranium diesel oil     which box completes the diagram?    ammoniaa bitumenb natural gasc steamd      ",
            "14": "14  \u00a9 ucles 2012 0620/12/m/j/12  36 the diagram shows apparatus used to separate petroleum into four fractions.    petroleum on rock wool heatthermometer water fraction    which fraction contains the smallest hydrocarbon molecules?    fraction boiling point range  / \u00b0c  a up to 70  b 70 to 120  c 120 to 170  d over 170      37 ethanol is a fuel used in cars. it can be made from petroleum.     c 4h10  \u2192  c2h4  +  c 2h6 cracking   c 2h4  +  h 2o  \u2192  c2h5oh producing ethanol   c 2h5oh  +  3o 2  \u2192  2co 2  +  3h 2o burning    compounds of how many homologous series appear in these equations?  a 1 b 2 c 3 d 4     ",
            "15": "15  \u00a9 ucles 2012 0620/12/m/j/12  38 butene is an alkene which is manufactured by cracking hydrocarbons.    h ch hhhh h hc c c     which hydrocarbon can be cracked to make butene?  a ethane, c 2h6  b decane, c 10h22  c methane, ch 4  d propane, c 3h8      39 which substance does not produce carbon dioxide when it burns in oxygen?  a butane  b ethanol  c ethene  d hydrogen     40 ethanol is an important chemical produced by the  \u2026\u20261\u2026\u2026  of  \u2026\u20262\u2026\u2026 .    which words correctly complete gaps 1 and 2?     1 2  a combustion ethane  b combustion glucose  c fermentation ethane  d fermentation glucose    ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2012 0620/12/m/j/12   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s12_qp_13.pdf": {
            "1": "    this document consists of 16 printed pages.  ib12 06_0620_13/fp  \u00a9 ucles 2012  [turn over       *7094438313* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  may/june 2012       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2012 0620/13/m/j/12  1 which diagram shows the process of diffusion?    a b c ddifferent atomskey       2 a student investigates how the concentration of an acid affects the speed of reaction with a 0.5  g  mass of magnesium at 30  \u00b0c.    the student has a beaker, concentrated acid, water and the apparatus below.    p a balance  q a clock  r a measuring cylinder  s a thermometer    which pieces of apparatus does the student use?  a p, q and r only  b p, q and s only  c q, r and s only  d p, q, r and s      3 which method is most suitable to obtain zinc carbonate from a suspension of zinc carbonate in  water?  a crystallisation  b distillation  c evaporation  d filtration     ",
            "3": "3  \u00a9 ucles 2012 0620/13/m/j/12 [turn over  4 the electronic structures of atoms p and q are shown.    q p= electron key      p and q react to form an ionic compound.    what is the formula of this compound?  a pq 2 b p2q c p2q6 d p6q2      5 an element y has the proton number 18.    the next element in the periodic table is an element z.    which statement is correct?  a element z has one more electron in its outer shell than element y.  b element z has one more electron shell than element y.  c element z is in the same group of the periodic table as element y.  d element z is in the same period of the periodic table as element y.      6 which atom has twice as many neutrons as protons?  a h1 1 b h2 1 c h3 1 d he4 2     7 which is a simple covalent molecule?    conducts electricity    when solid when molten volatile  a \u0013 \u0013 \u0017  b \u0013 \u0017 \u0013  c \u0017 \u0013 \u0017  d \u0017 \u0017 \u0013    ",
            "4": "4  \u00a9 ucles 2012 0620/13/m/j/12  8 the equation for the reaction between magnesium and dilute sulfuric acid is shown.    mg  +  h 2so 4  \u2192  mgso 4  +  h 2   m r of mgso 4 is 120    which mass of magnesium sulfate will be formed if 12  g of magnesium are reacted with sulfuric  acid?  a 5  g b 10  g c 60  g d 120  g      9 the diagrams show the structures of two forms, p and q, of a solid element.    pq     what are suitable uses of p and q, based on their structures?     use of solid p use of solid q  a drilling drilling  b lubricating drilling  c drilling lubricating  d lubricating lubricating     ",
            "5": "5  \u00a9 ucles 2012 0620/13/m/j/12 [turn over  10 winston churchill, a british prime minister, had his false teeth electroplated with gold.    the teeth were coated with a thin layer of car bon and were then placed in the apparatus shown.    false teethswitch gold aqueous solution of a gold saltxy     which row is correct?     terminal x is the carbon powder  could be  a negative diamond  b negative graphite  c positive diamond  d positive graphite     ",
            "6": "6  \u00a9 ucles 2012 0620/13/m/j/12  11 the apparatus shown is used to measure the speed of a reaction.    gas syringe reactants     which equation represents a reaction where the speed can be measured using this apparatus?  a mg(s)  +  2hc l (aq)  \u2192  mgc l 2(aq)  +  h 2(g)  b hc l (aq)  +  naoh(aq)  \u2192  nac l (aq)  +  h 2o(l)  c fe(s)  +  cuso 4(aq)  \u2192  cu(s)  +  feso 4(aq)  d 2na(s)  +  br 2(l)  \u2192  2nabr(s)     12 the diagram shows the reaction between zinc oxide and dilute hydrochloric acid.    dilute hydrochloric acid 20  \u00b0c ph  1aqueous zinc chloride22  \u00b0c ph  7 before afterzinc oxide powder     which terms describe the reaction?     endothermic neutralisation  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "7": "7  \u00a9 ucles 2012 0620/13/m/j/12 [turn over  13 the diagram shows that two gases are formed when concentrated hydrochloric acid is  electrolysed using inert electrodes.    +ve \u2013ve concentrated hydrochloric acid     which row correctly describes the colours of the gases at the electrodes?     anode (+ve) cathode (\u2013ve)  a colourless colourless  b colourless yellow-green  c yellow-green colourless  d yellow-green yellow-green      14 a gas is escaping from a pipe in a chemical plant.    a chemist tests this gas and finds that it is alkaline.    what is this gas?  a ammonia  b chlorine  c hydrogen  d sulfur dioxide       15 the element vanadium, v, forms several oxides.    in which change is oxidation taking place?  a vo 2 \u2192 v 2o3  b v2o5 \u2192 vo 2  c v2o3 \u2192 vo  d v2o3 \u2192 v 2o5     ",
            "8": "8  \u00a9 ucles 2012 0620/13/m/j/12  16 dilute hydrochloric acid is added to a solid, s.    a flammable gas, g, is formed. gas g is less dense than air.    what are s and g?     solid s gas g  a copper hydrogen  b copper carbonate carbon dioxide  c zinc hydrogen  d zinc carbonate carbon dioxide      17 the results of three tests on a solution of compound x are shown in the table.    test result  aqueous sodium hydroxide added white precipitate formed, soluble in excess  aqueous ammonia added white precipitate formed, insoluble in excess  acidified silver nitrate added white precipitate formed    what is compound x?  a aluminium bromide  b aluminium chloride  c zinc bromide  d zinc chloride     18 the graph shows how the ph changes as an acid is added to an alkali.    acid  +  alkali  \u2192  salt  +  water    which letter represents the area of the graph where both acid and salt are present?    pha b c d14 7 0     ",
            "9": "9  \u00a9 ucles 2012 0620/13/m/j/12 [turn over  19 which properties of the element titanium, ti, can be predicted from its position in the periodic  table?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0013 \u0013 \u0017 \u0013  b \u0013 \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013 \u0013  d \u0017 \u0013 \u0013 \u0013     20 the diagram shows a section of the periodic table.    which element is described below?    \u2018a colourless, unreactive gas that is denser than air.\u2019    a b c d       21 element x is below iodine in the periodic table.    which row correctly shows the physical state of element x at room temperature and its reactivity  compared with that of iodine?     physical state  of element x at  room temperature reactivity compared  with that of iodine  a gas less reactive  b solid less reactive  c gas more reactive  d solid more reactive     ",
            "10": "10  \u00a9 ucles 2012 0620/13/m/j/12  22 which property is shown by all metals?  a they are extracted from their ores by heating with carbon.  b they conduct electricity.  c they form acidic oxides.  d they react with hydrochloric acid to form hydrogen.      23 five elements have proton numbers 10, 12, 14, 16 and 18.    what are the proton numbers of the three elements that form oxides?  a 10, 12 and 14  b 10, 14 and 18  c 12, 14 and 16  d 14, 16 and 18     24 metal x reacts violently with water.    metal y reacts slowly with steam.    metal z does not react with dilute hydrochloric acid.    what is the correct order of reactivity of these metals, most reactive first?  a x \u2192 y \u2192 z  b x \u2192 z \u2192 y  c z \u2192 x \u2192 y  d z \u2192 y \u2192 x      25 which statement about the extraction of iron from its ore is correct?  a iron is more difficult to extract than zinc.  b iron is more difficult to extract than copper.  c iron is easy to extract because it is a transition metal.  d iron cannot be extracted by reduction with carbon.      26 which statement about the uses of metals is correct?  a aluminium is used in the manufacture of aircraft as it has a high density.  b aluminium is used to make food containers as it conducts electricity.  c stainless steel for cutlery is made by adding other elements to iron.  d stainless steel is used to make chemical reactors as it corrodes readily. ",
            "11": "11  \u00a9 ucles 2012 0620/13/m/j/12 [turn over  27 fertilisers need to supply crops with three main elements.    which compound contains all three of these elements?  a h 3po 4 b kno 3 c nh 4k2po 4 d nh 4no 3     28 some uses of water are listed.    1 for drinking  2 in chemical reactions 3 in swimming pools  4 in washing    for which uses is it necessary to chlorinate the water?  a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     29 which is a use of oxygen?  a filling balloons  b filling light bulbs  c food preservation  d making steel    30 coal is a fossil fuel.    which gas is not formed when coal burns?  a carbon dioxide  b carbon monoxide  c methane  d sulfur dioxide     ",
            "12": "12  \u00a9 ucles 2012 0620/13/m/j/12  31 air containing an acidic impurity was neutralised by passing it through a column containing  substance x.    acidic air neutralised ai rsubstance x     what is substance x?  a calcium oxide  b sand  c sodium chloride  d concentrated sulfuric acid     32 a new planet has been discovered a nd its atmosphere has been analysed.    atmosphere planet     the table shows the composition of the atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only    ",
            "13": "13  \u00a9 ucles 2012 0620/13/m/j/12 [turn over  33 the structure of a compound is shown.    ch co ohh h hc c h     which functional groups are present in this compound?     alcohol alkene carboxylic acid  a \u0013 \u0013 \u0013  b \u0013 \u0017 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0017 \u0013      34 gas x is a waste gas from digestion in animals.    gas y is formed when gas x is burnt with a small amount of oxygen.    gas z is formed when gas x is burnt with an excess of oxygen.    what are x, y and z?     x y z  a carbon dioxide methane carbon monoxide  b carbon monoxide methane carbon dioxide  c methane carbon dioxide carbon monoxide  d methane carbon monoxide carbon dioxide     35 which fraction from the fractional distillation of petroleum does not match its correct use?     fraction use  a fuel oil domestic heating  b kerosene jet fuel  c naphtha making roads  d refinery gas for heating and cooking    ",
            "14": "14  \u00a9 ucles 2012 0620/13/m/j/12  36 when a long chain hydrocarbon is cracked, the following products are produced.    1 c 3h8  2 c 2h4  3 c 3h6  4 c 2h6    which products would decolourise bromine water?  a 1 and 4 b 2 and 3 c 2 only d 3 only      37 the diagram shows apparatus used to separate petroleum into four fractions.    petroleum on rock wool heatthermometer water fraction    which fraction contains the smallest hydrocarbon molecules?    fraction boiling point range  / \u00b0c  a up to 70  b 70 to 120  c 120 to 170  d over 170     ",
            "15": "15  \u00a9 ucles 2012 0620/13/m/j/12  38 pva is a polymer. the monomer has the structure shown.    c coh hh h    to which homologous series does this compound belong?     alcohols alkenes  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     39 ethanol is an important chemical produced by the  \u2026\u20261\u2026\u2026  of  \u2026\u20262\u2026\u2026 .    which words correctly complete gaps 1 and 2?     1 2  a combustion ethane  b combustion glucose  c fermentation ethane  d fermentation glucose    40 which equation represents incomplete combustion of ethane?  a c 2h6  +  o 2  \u2192  2co  +  3h 2  b c 2h6  +  2o 2  \u2192  2co 2  +  3h 2  c 2c 2h6  +  5o 2  \u2192  4co  +  6h 2o  d 2c 2h6  +  7o 2  \u2192  4co 2  +  6h 2o    ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2012 0620/13/m/j/12   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s12_qp_21.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 may/june 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib12 06_0620_21/3rp\u00a9 ucles 2012 *3940916627* for examiner\u2019s use 1 234567 total",
            "2": "2 0620/21/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  stearic acid is a solid at room temperature.   the diagram below shows the apparatus used for \ufb01 nding the melting point of stearic acid.  the apparatus was heated at a steady rate and the temperature recorded every minute. stearic acidstirrer heatwate rba  (a)  state the name of the piece of apparatus labelled  a,  ..   b.  .. ..  [2]  (b) (i)   suggest why the water needs to be kept stirred during this experiment.   . ...   . .  [1]  (ii)  describe a chemical test for water.  test   .  result    [2]",
            "3": "3 0620/21/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  a graph of temperature of stearic acid against time of heating is shown below. 100 80 604020 0 02468 1 0 1 2 time  / minutestemperature  / \u00b0c  (i)  what was the temperature of the stearic acid after 3 minutes heating?   . .  [1]  (ii)  use the information on the graph to determine the melting point of stearic acid.   . .  [1]  (d)  describe the arrangement and motion of the particles in liquid stearic acid.  arrangement  .   motion  .. ...  [2]",
            "4": "4 0620/21/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (e)   a sample of stearic acid contained 1  % of another compound with a higher relative  molecular mass.  (i)  which one of the following statements about this sample of stearic acid is correct?  tick one box.  its density is exactly the same as that of pure stearic acid.  its boiling point is the same as that of pure stearic acid. its melting point is different from pure stearic acid. its melting point is the same as that of pure stearic acid. [1]  (ii)  describe one area of everyday life where the purity of substances is important.   . .  [1] [total: 11]",
            "5": "5 0620/21/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  the diagram below shows the structure of some substances, a, b, c, d and e. c hhh cs h hh hs ha os oebc ds ss ss ss s na+ s2\u2013na+ na+ s2\u2013na+na+ s2\u2013na+ na+ s2\u2013na+  (a) (i)   which one of these substances, a, b, c, d or e, is an element?   . .  [1]  (ii)  what do you understand by the term element  ?   . .  [1]  (b)  calculate the relative molecular mass of e. [1]  (c)  write the simplest formula for d.   ... ..  [1]  (d)  which substance, a, b, c, d or e, conducts electricity when it is molten?  explain your answer.   ...    ... ..  [2]  (e)  the equation for the combustion of substance a is shown below. 2h2s  +  3o2  \u2192  2h2o  +  2so2  what type of chemical reaction is this?  put a ring around the correct answer.  decomposition neutralisation oxidation reversible [1] [total: 7]",
            "6": "6 0620/21/m/j/12 \u00a9 ucles 2012for examiner\u2019s use3  hydrochloric acid and ethanoic acid are both acidic in nature.  (a)  which one of the following is a ph value for an acidic solution.   put a ring around the correct answer.  ph  3 ph  7 ph  9 ph  13 [1]  (b)  describe how you would use litmus to test if a solution is acidic.   ...    ...    ... ..  [3]  (c)  acids react with metal carbonates.  (i)  write a word equation for the reaction of calcium carbonate with hydrochloric acid. [3]  (ii)  calcium carbonate can be used to treat acidic soil.   state one other use of calcium carbonate.   . .  [1]  (iii)  name one other compound that can be used to treat acidic soil.   . .  [1]  (d)  hydrochloric acid reacts with iron to form iron( ii) chloride and hydrogen.   complete the equation for this reaction. fe  +  hc l  \u2192  fec l 2  +   [2]",
            "7": "7 0620/21/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (e) (i)   complete the table below to show:  \u25cf the molecular formula for ethanoic acid  \u25cf the full structural formula for ethanol. ethanoic acid ethanol full structural formula ch hco ohh molecular formula c2h6o [2]  (ii)  ethanol can be manufactured by the catalytic addition of steam to ethene. complete  the equation for this reaction.   +  ..  \u2192  c2h5oh [1] [total: 14]",
            "8": "8 0620/21/m/j/12 \u00a9 ucles 2012for examiner\u2019s use4  fractional distillation is used to separate petroleum into different fractions.  each fraction has a particular use.  (a)  match the fractions on the left with their uses on the right.   the \ufb01 rst one has been done for you. heating fuel for ships surfacing roads waxes and polishes making chemicalsgas oil bitumen lubricating fraction refinery gases naphtha  [4]  (b)  petroleum fractions contain hydrocarbons.   what do you understand by the term hydrocarbon  ?   ... ..  [1]  (c)  methane, ch4, is a hydrocarbon.  (i)  draw the structure of methane, showing all atoms and bonds. [1]  (ii)  complete the following equation for the burning of methane in excess oxygen. ch4  +  .o2  \u2192  ..  +  2h2o [2]",
            "9": "9 0620/21/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (iii)  methane belongs to a homologous series called the alkanes.   what do you understand by the term homologous series  ?   . ...   . .  [2]  (iv)  name the second member of the alkane homologous series.   . .  [1] [total: 11]",
            "10": "10 0620/21/m/j/12 \u00a9 ucles 2012for examiner\u2019s use5  a student investigated the reaction between zinc and hydrochloric acid using the apparatus  shown below.  the zinc was in excess. zinc  +  hydrochloric acid  \u2192  zinc chloride  +  hydrogen hydrochloric acidsmall test-tube held by a piece of cotton zinc powdermeasuring cylinde r water  (a)  what should the student do to start the reaction?   ... ..  [1]  (b)  the student measured the volume of gas in the measuring cylinder at minute intervals.   the results are shown in the table. time  / minutes 0 1234567 volume of gas  / cm30 1 52 33 03 33 53 53 5  (i)  plot the results on the grid below and draw the best curve through the points. 1 02 3 4 time  / minutesvolume of gas  / cm3 56740 302010 0 [3]",
            "11": "11 0620/21/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  explain why the volume of gas stays the same after 5 minutes.   . ...   . .  [2]  (c)  complete the following sentences about this reaction using words or phrases from the  list below.  concentration decreases increases speed stays the same volume  when the . of hydrochloric acid is increased, the volume of gas given  off in the \ufb01 rst two minutes . . decreasing the temperature of the reaction  mixture . the . of the reaction. [4]  (d)  when the reaction is complete, the \ufb02 ask contains a mixture of zinc and aqueous zinc  chloride.   describe how you can obtain pure dry crystals of zinc chloride from this reaction mixture.   ...    ...    ...    ... ..  [3] [total: 13]",
            "12": "12 0620/21/m/j/12 \u00a9 ucles 2012for examiner\u2019s use6  lithium, sodium and potassium are in group i of the periodic table.  (a)  the equation for the reaction of lithium with water is 2li  +  2h2o  \u2192  2lioh  +  h2  (i)  write a word equation for this reaction.   . .  [2]  (ii)  sodium reacts with water in a similar way to lithium.   write a symbol equation for the reaction of sodium with water. [1]  (b)  describe the reactions of lithium, sodium and potassium with water.  in your description, write about:  \u25cf the difference in the reactivity of the metals  \u25cf the observations you would make when these metals react with water.   ...    ...    ...    ...    ...    ...    ... ..  [5]",
            "13": "13 0620/21/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  the diagram below shows an electrolysis cell used to manufacture sodium from molten  sodium chloride. \u2013 \u2013 +abc d e  (i)  which letter in the diagram above represents  the anode? .. the electrolyte? .. [2] (ii)  state the name of the product formed  at the positive electrode,   at the negative electrode.    [2] (iii)  which one of the following substances is most likely to be used for the anode?  put a ring around the correct answer.  graphite iodine magnesium sodium [1]  (d)  lithium, sodium and potassium are metals with a low density.   state two other physical properties of these metals.  1.  ...   2.  ... ..  [2] [total: 15]",
            "14": "14 0620/21/m/j/12 \u00a9 ucles 2012for examiner\u2019s use7 (a)   the equations a and b below show two reactions which lead to the formation of acid  rain.  a s  +  o2  \u2192  so2  b so2  +  o3  \u2192  so3  +  o2  (i)  write a word equation for reaction a.   . .  [2]  (ii)  which two of the following statements about reaction b are correct?  tick two boxes.  so2 is oxidised to so3  so2 is reduced to so3  o3 is reduced to o2  o3 is oxidised to o2   [2]  (iii)  complete the equation to show how an aqueous solution of sulfuric acid, h2so4, is  formed from so3. so3  +    \u2192  h2so4 [1]  (b)  describe and explain the effect of sulfuric acid on buildings made from limestone (calcium  carbonate).   ...    ...    ...    ... ..  [3]  (c)  state one effect of acid rain other than on buildings.   ... ..  [1] [total: 9]",
            "15": "15 0620/21/m/j/12blank page \u00a9 ucles 2012",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/21/m/j/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s12_qp_22.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 may/june 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib12 06_0620_22/3rp\u00a9 ucles 2012 *7086809263* for examiner\u2019s use 1 234567 total",
            "2": "2 0620/22/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1 (a)  gases can be identi \ufb01 ed by carrying out particular tests.   some gases and tests to identify them are shown below.   match the gases on the left with the tests on the right.   the \ufb01 rst one has been done for you. turns limewater milky turns potassium dichromate green \u2018pops\u2019 with a lighted splint relights a glowing splint bleaches damp litmus papersulfur dioxide carbon dioxide chlorine oxygen hydrogen [4]  (b)  chlorine can be prepared by heating hydrochloric acid with manganese( iv) oxide. mno2  +  4hc l  \u2192  mnc l 2  +  c l 2  +  2h2o  (i)  write a word equation for this reaction. [3]",
            "3": "3 0620/22/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  chlorine is  \u25cf denser than air  \u25cf soluble in water.   which one of the following diagrams, a, b or c, best describes how chlorine gas is  collected? abc water answer = .  [1]  (c)  hydrogen reacts with oxygen to form water.  (i)  complete the equation for this reaction. 2h2  +  ...  \u2192  .h2o [2]  (ii)  state one use of  hydrogen,  ... water.  ...  [ 2] [total: 12]",
            "4": "4 0620/22/m/j/12 \u00a9 ucles 2012for examiner\u2019s use2  alkalis are soluble bases.  (a)  which one of the following is alkaline?   put a ring around the correct answer.  distilled water hydrochloric acid sodium chloride solution sodium hydroxide solution [1]  (b)  suggest a ph value for a solution which is alkaline.   ... ..  [1]  (c)  describe how you would \ufb01 nd the ph of a solution.   ...    ...    ... ..  [2]  (d)  when excess fertilisers are put on the soil, the soil may become acidic.  (i)  why is it important to farmers that the soil does not become too acidic?   . .  [1]  (ii)  calcium carbonate is used to decrease the acidity of the soil. explain how calcium  carbonate decreases soil acidity.   . ...   . .  [2] [total: 7]",
            "5": "5 0620/22/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use3  the table below shows some properties of the halogens. halogen melting point  / \u00b0c boiling point  / \u00b0c colour chlorine \u2013101 \u201335 bromine \u20137 +59 iodine +114 +184 greyish-black  (a) (i)   complete the spaces in the table to show the colours of chlorine and bromine. [2]  (ii)  room temperature is about 20  \u00b0c.   use the information in the table to explain why  chlorine is a gas at room temperature,  ..  . ...  bromine is a liquid at room temperature.  ...  . .  [2]  (iii)  astatine is the halogen below iodine in the periodic table.   suggest a value for the melting point of astatine.   . .  [1]  (b)  chlorine reacts with an aqueous solution of potassium iodide.  (i)  complete the balanced equation for this reaction. cl  2  +  .k i  \u2192  2kc l  +  ... [2]  (ii)  state the names of the products of this reaction.   . .  [2]  (iii)  to which period in the periodic table does chlorine belong?   . .  [1]  (c)  complete the following sentences about the test for iodide ions using words from the list  below.  hydrochloric nitric potassium precipitate  silver solution white yellow  a small volume of solution containing aqueous iodide ions is put into a test-tube. dilute   acid is added followed by a few drops of  nitrate solution. a  coloured  is formed if iodide ions are present. [4] [total: 14]",
            "6": "6 0620/22/m/j/12 \u00a9 ucles 2012for examiner\u2019s use4  the diagram below shows the structure of some substances containing nitrogen. ch2h2n coohhnn n hha ebc dnh4+no3\u2013nh4+no3\u2013 nh4+no3\u2013nh4+no3\u2013nh4+no3\u2013nh4+no3\u2013 cln clcl  (a) (i)   which one of these substances, a, b, c, d or e, is an alkaline gas?  (ii)  which one of these substances is an ionic salt?  (iii)  which one of these substances contains a carboxylic acid functional group? [3]  (b)  oxides of nitrogen such as nitrogen dioxide, no2, are atmospheric pollutants.   give one source of nitrogen oxides in the air.   ... ..  [1]  (c)  state one harmful effect of nitrogen dioxide.   ... ..  [1]  (d)  calculate the relative formula mass of nitrogen dioxide, no2. [1]  (e)  in the presence of a catalyst, nitrogen dioxide reacts with carbon monoxide. 2no2  +  4co  \u2192  n2  +  4co2  (i)  which substance gets oxidised during this reaction? explain your answer.   . ...   . .  [2]",
            "7": "7 0620/22/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  what is the meaning of the term catalyst  ?   . .  [1]  (iii)  carbon monoxide is formed when some of the air holes in a water heater get blocked.   the diagram shows a water heater. cold water inhot water out gas burning in air air holescombustion products   explain why carbon monoxide is formed when some of the air holes in a water  heater get blocked.   . ...   . .  [2]  (iv)  explain why carbon monoxide is dangerous.   . .  [1] [total: 12]",
            "8": "8 0620/22/m/j/12 \u00a9 ucles 2012for examiner\u2019s use5  iron is a shiny metallic solid. iron is a transition element.  (a)  state three  other physical properties of a transition element.   ...    ...    ... ..  [3]  (b)  iron reacts with sulfuric acid. fe  +  h2so4  \u2192  feso4  +  h2  (i)  write a word equation for this reaction.   . .  [2]  (ii)  describe, with the aid of a diagram, how you could measure the speed of this  reaction.   in your answer describe:  \u25cf the apparatus you would use  \u25cf the measurements you would take.   . ...   . ...   . ...   . .  [4]  (c)  when iron reacts with sulfur, energy is released.  (i)  what is the name given to a reaction which releases energy?   . .  [1]",
            "9": "9 0620/22/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  the compound formed in this reaction is iron( ii) sul \ufb01 de.   what do you understand by the term compound  ?   . ...   . .  [1]  (iii)  the diagram below shows the structure of iron( ii) sul \ufb01 de. fe atoms s atoms  what is the simplest formula for iron( ii) sul \ufb01 de?   . .  [1] [total: 12]",
            "10": "10 0620/22/m/j/12 \u00a9 ucles 2012for examiner\u2019s use6  the diagram shows a fractionating column used to separate different hydrocarbon fractions  in an oil re \ufb01 nery. petroleumrefinery gasfractions gasoline a kerosene diesel oil fuel oil lubricating oil bitumen  (a)  on the diagram, draw an x to show the place in the column where the temperature is the  highest. [1]  (b)  state the name of the fraction labelled a.   ... ..  [1]  (c)  state a use for  the kerosene fraction,  .. .  the diesel oil fraction.  ..  [2]",
            "11": "11 0620/22/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (d)  complete the following sentences about fractional distillation using words from the list  below.  boiling condenses cooled heated higher  lower melting mixture pressure vaporises  petroleum is a  of hydrocarbons. this mixture is   and the hydrocarbons vaporise. the temperature in the fractionating column is    at the top than at the bottom. as the vapours move up the column, each hydrocarbon fraction  when the temperature in the column falls below the  point of the hydrocarbon fraction. [5]  (e) the structures of four hydrocarbons, a, b, c and d, are shown below. a c h hh cc hhh hhb c h hh cc hh ch h hhhcd c hh cc hhc hhhhch cc hh hh hc hh  (i)  which two of these structures a, b, c or d have the same relative molecular mass?  ..  and  .. [1 ]  (ii)  which two of these structures a, b, c or d will decolourise aqueous bromine?  ..  and  .. [2 ] [total: 12]",
            "12": "12 0620/22/m/j/12 \u00a9 ucles 2012for examiner\u2019s use7  a student placed some crystals of salt at the bottom of a beaker of distilled water. she left the  contents of the beaker to stand for one hour.   the diagram below shows her observations. distilled water at start after 15 minutes after 1 hourxx salt crystals   after one hour, all the salt had disappeared but the solution at point x tasted salty.  (a)  use the kinetic particle theory to explain these observations.   ...    ...    ...    ...    ... ..  [4]  (b)  salt is sodium chloride, nac l.  (i)  which one of the following statements about bond formation in sodium chloride is  true?   tick one box.   a sodium atom shares one electron with a chlorine atom.   a sodium atom loses its outermost electron and a chlorine  atom gains an electron.   a sodium atom shares two electrons with a chlorine atom.   a sodium atom gains an electron and a chlorine atom  loses its outermost electrons. [1]",
            "13": "13 0620/22/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  explain why solid sodium chloride does not conduct electricity but molten sodium  chloride does conduct.   . ...   . ...   . .  [2]  (iii)  state the name of the product formed at each electrode when a concentrated  aqueous solution of sodium chloride is electrolysed using graphite electrodes.  at the positive electrode  . at the negative electrode  .  [2] (iv)  what is the name of the negative electrode?   put a ring around the correct answer.  anion anode cation cathode electrolyte [1]  (v)  suggest why graphite is a suitable material for an electrode.   . .  [1] [total: 11]",
            "14": "14 0620/22/m/j/12blank page \u00a9 ucles 2012",
            "15": "15 0620/22/m/j/12blank page \u00a9 ucles 2012",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/22/m/j/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s12_qp_23.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/23   paper 2 may/june 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib12 06_0620_23/fp\u00a9 ucles 2012 *5356166968* for examiner\u2019s use 1 234567 total",
            "2": "2 0620/23/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1 (a)  gases can be identi \ufb01 ed by carrying out particular tests.   some gases and tests to identify them are shown below.   match the gases on the left with the tests on the right.   the \ufb01 rst one has been done for you. turns limewater milky turns potassium dichromate green \u2018pops\u2019 with a lighted splint relights a glowing splint bleaches damp litmus papersulfur dioxide carbon dioxide chlorine oxygen hydrogen [4]  (b)  chlorine can be prepared by heating hydrochloric acid with manganese( iv) oxide. mno2  +  4hc l  \u2192  mnc l 2  +  c l 2  +  2h2o  (i)  write a word equation for this reaction. [3]",
            "3": "3 0620/23/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  chlorine is  \u25cf denser than air  \u25cf soluble in water.   which one of the following diagrams, a, b or c, best describes how chlorine gas is  collected? abc water answer = .  [1]  (c)  hydrogen reacts with oxygen to form water.  (i)  complete the equation for this reaction. 2h2  +  ...  \u2192  .h2o [2]  (ii)  state one use of  hydrogen,  ... water.  ...  [ 2] [total: 12]",
            "4": "4 0620/23/m/j/12 \u00a9 ucles 2012for examiner\u2019s use2  alkalis are soluble bases.  (a)  which one of the following is alkaline?   put a ring around the correct answer.  distilled water hydrochloric acid sodium chloride solution sodium hydroxide solution [1]  (b)  suggest a ph value for a solution which is alkaline.   ... ..  [1]  (c)  describe how you would \ufb01 nd the ph of a solution.   ...    ...    ... ..  [2]  (d)  when excess fertilisers are put on the soil, the soil may become acidic.  (i)  why is it important to farmers that the soil does not become too acidic?   . .  [1]  (ii)  calcium carbonate is used to decrease the acidity of the soil. explain how calcium  carbonate decreases soil acidity.   . ...   . .  [2] [total: 7]",
            "5": "5 0620/23/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use3  the table below shows some properties of the halogens. halogen melting point  / \u00b0c boiling point  / \u00b0c colour chlorine \u2013101 \u201335 bromine \u20137 +59 iodine +114 +184 greyish-black  (a) (i)   complete the spaces in the table to show the colours of chlorine and bromine. [2]  (ii)  room temperature is about 20  \u00b0c.   use the information in the table to explain why  chlorine is a gas at room temperature,  ..  . ...  bromine is a liquid at room temperature.  ...  . .  [2]  (iii)  astatine is the halogen below iodine in the periodic table.   suggest a value for the melting point of astatine.   . .  [1]  (b)  chlorine reacts with an aqueous solution of potassium iodide.  (i)  complete the balanced equation for this reaction. cl  2  +  .k i  \u2192  2kc l  +  ... [2]  (ii)  state the names of the products of this reaction.   . .  [2]  (iii)  to which period in the periodic table does chlorine belong?   . .  [1]  (c)  complete the following sentences about the test for iodide ions using words from the list  below.  hydrochloric nitric potassium precipitate  silver solution white yellow  a small volume of solution containing aqueous iodide ions is put into a test-tube. dilute   acid is added followed by a few drops of  nitrate solution. a  coloured  is formed if iodide ions are present. [4] [total: 14]",
            "6": "6 0620/23/m/j/12 \u00a9 ucles 2012for examiner\u2019s use4  the diagram below shows the structure of some substances containing nitrogen. ch2h2n coohhnn n hha ebc dnh4+no3\u2013nh4+no3\u2013 nh4+no3\u2013nh4+no3\u2013nh4+no3\u2013nh4+no3\u2013 cln clcl  (a) (i)   which one of these substances, a, b, c, d or e, is an alkaline gas?  (ii)  which one of these substances is an ionic salt?  (iii)  which one of these substances contains a carboxylic acid functional group? [3]  (b)  oxides of nitrogen such as nitrogen dioxide, no2, are atmospheric pollutants.   give one source of nitrogen oxides in the air.   ... ..  [1]  (c)  state one harmful effect of nitrogen dioxide.   ... ..  [1]  (d)  calculate the relative formula mass of nitrogen dioxide, no2. [1]  (e)  in the presence of a catalyst, nitrogen dioxide reacts with carbon monoxide. 2no2  +  4co  \u2192  n2  +  4co2  (i)  which substance gets oxidised during this reaction? explain your answer.   . ...   . .  [2]",
            "7": "7 0620/23/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  what is the meaning of the term catalyst  ?   . .  [1]  (iii)  carbon monoxide is formed when some of the air holes in a water heater get blocked.   the diagram shows a water heater. cold water inhot water out gas burning in air air holescombustion products   explain why carbon monoxide is formed when some of the air holes in a water  heater get blocked.   . ...   . .  [2]  (iv)  explain why carbon monoxide is dangerous.   . .  [1] [total: 12]",
            "8": "8 0620/23/m/j/12 \u00a9 ucles 2012for examiner\u2019s use5  iron is a shiny metallic solid. iron is a transition element.  (a)  state three  other physical properties of a transition element.   ...    ...    ... ..  [3]  (b)  iron reacts with sulfuric acid. fe  +  h2so4  \u2192  feso4  +  h2  (i)  write a word equation for this reaction.   . .  [2]  (ii)  describe, with the aid of a diagram, how you could measure the speed of this  reaction.   in your answer describe:  \u25cf the apparatus you would use  \u25cf the measurements you would take.   . ...   . ...   . ...   . .  [4]  (c)  when iron reacts with sulfur, energy is released.  (i)  what is the name given to a reaction which releases energy?   . .  [1]",
            "9": "9 0620/23/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  the compound formed in this reaction is iron( ii) sul \ufb01 de.   what do you understand by the term compound  ?   . ...   . .  [1]  (iii)  the diagram below shows the structure of iron( ii) sul \ufb01 de. fe atoms s atoms  what is the simplest formula for iron( ii) sul \ufb01 de?   . .  [1] [total: 12]",
            "10": "10 0620/23/m/j/12 \u00a9 ucles 2012for examiner\u2019s use6  the diagram shows a fractionating column used to separate different hydrocarbon fractions  in an oil re \ufb01 nery. petroleumrefinery gasfractions gasoline a kerosene diesel oil fuel oil lubricating oil bitumen  (a)  on the diagram, draw an x to show the place in the column where the temperature is the  highest. [1]  (b)  state the name of the fraction labelled a.   ... ..  [1]  (c)  state a use for  the kerosene fraction,  .. .  the diesel oil fraction.  ..  [2]",
            "11": "11 0620/23/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (d)  complete the following sentences about fractional distillation using words from the list  below.  boiling condenses cooled heated higher  lower melting mixture pressure vaporises  petroleum is a  of hydrocarbons. this mixture is   and the hydrocarbons vaporise. the temperature in the fractionating column is    at the top than at the bottom. as the vapours move up the column, each hydrocarbon fraction  when the temperature in the column falls below the  point of the hydrocarbon fraction. [5]  (e) the structures of four hydrocarbons, a, b, c and d, are shown below. a c h hh cc hhh hhb c h hh cc hh ch h hhhcd c hh cc hhc hhhhch cc hh hh hc hh  (i)  which two of these structures a, b, c or d have the same relative molecular mass?  ..  and  .. [1 ]  (ii)  which two of these structures a, b, c or d will decolourise aqueous bromine?  ..  and  .. [2 ] [total: 12]",
            "12": "12 0620/23/m/j/12 \u00a9 ucles 2012for examiner\u2019s use7  a student placed some crystals of salt at the bottom of a beaker of distilled water. she left the  contents of the beaker to stand for one hour.   the diagram below shows her observations. distilled water at start after 15 minutes after 1 hourxx salt crystals   after one hour, all the salt had disappeared but the solution at point x tasted salty.  (a)  use the kinetic particle theory to explain these observations.   ...    ...    ...    ...    ... ..  [4]  (b)  salt is sodium chloride, nac l.  (i)  which one of the following statements about bond formation in sodium chloride is  true?   tick one box.   a sodium atom shares one electron with a chlorine atom.   a sodium atom loses its outermost electron and a chlorine  atom gains an electron.   a sodium atom shares two electrons with a chlorine atom.   a sodium atom gains an electron and a chlorine atom  loses its outermost electrons. [1]",
            "13": "13 0620/23/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  explain why solid sodium chloride does not conduct electricity but molten sodium  chloride does conduct.   . ...   . ...   . .  [2]  (iii)  state the name of the product formed at each electrode when a concentrated  aqueous solution of sodium chloride is electrolysed using graphite electrodes.  at the positive electrode  . at the negative electrode  .  [2] (iv)  what is the name of the negative electrode?   put a ring around the correct answer.  anion anode cation cathode electrolyte [1]  (v)  suggest why graphite is a suitable material for an electrode.   . .  [1] [total: 11]",
            "14": "14 0620/23/m/j/12blank page \u00a9 ucles 2012",
            "15": "15 0620/23/m/j/12blank page \u00a9 ucles 2012",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/23/m/j/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s12_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) may/june 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib12 06_0620_31/4rp\u00a9 ucles 2012 *0978813545* for examiner\u2019s use 1 2345678 total",
            "2": "2 0620/31/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  the diagram below shows part of the water cycle. seah2o(g) h2o(l)suncloud h2o(l) landrain  (a) (i)   state the name of each of the following changes of state. h2o(l)  \u2192  h2o(g)  name   .. h2o(g)  \u2192  h2o(l)  name   .. [2]  (ii) which one of the above changes of state is exothermic? explain your choice.   . ...   . .  [1]  (b)  the rain drains into rivers and then into reservoirs. describe how water is treated before  it enters the water supply.   ...    ... ..  [2]  (c) (i)  explain how acid rain is formed.   . ...   . ...   . ...   . .  [4]",
            "3": "3 0620/31/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  fish live in water which is neutral (neither acidic nor alkaline). acid rain decreases  the ph of water in lakes and rivers. both of the bases, calcium oxide and calcium carbonate, can neutralise this acid and increase the ph. explain why calcium carbonate is a better choice.   . ...   . .  [2] [total: 11] 2  three ways of making salts are  \u25cf titration using a soluble base or carbonate  \u25cf neutralisation using an insoluble base or carbonate  \u25cf precipitation.  (a) complete the following table of salt preparations. method reagent 1 reagent 2 salt titration ... .. ...sodium nitrate neutralisation nitric acid ... ...copper( ii) nitrate precipitation ... .. ...silver( i) chloride neutralisation sulfuric acid zinc( ii) carbonate ... ... [6]  (b) (i)   write an ionic equation with state symbols for the preparation of silver( i) chloride.   . .  [2]  (ii) complete the following equation. znco3  +  h2so4  \u2192  ...  +  ...  +  ... [2] [total: 10]",
            "4": "4 0620/31/m/j/12 \u00a9 ucles 2012for examiner\u2019s use3  the group i metals show trends in both their physical and chemical properties.  (a) (i)   how do their melting points vary down the group?   . .  [1]  (ii)  which element in the group has the highest density?   . .  [1]  (iii)  all group i metals react with cold water. complete the following equation. rb  +  h2o  \u2192    +   [2]  (b)  lithium reacts with nitrogen to form the ionic compound, lithium nitride.  (i)  state the formula of the lithium ion. .\u2026\u2026.. [1]  (ii)  deduce the formula of the nitride ion. .\u2026\u2026.. [1]  (iii)  in all solid ionic compounds, the ions are held together in a lattice.  explain the term lattice .   . ...   . .  [1]  (iv)  what is the ratio of lithium ions to nitride ions in the lattice of lithium nitride?  give a reason for your answer.   lithium ions :  nitride ions   . ...   . .  [2] [total: 9] 4  vanadium is a transition element. it has more than one oxidation state.   the element and its compounds are often used as catalysts.  (a)  complete the electron distribution of vanadium by inserting one number. 2  +  8  +  ..  +  2 [1]  (b) predict three  physical properties of vanadium which are typical of transition elements.  1.  ...   2.  ...   3.  ... ..  [2]",
            "5": "5 0620/31/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  vanadium(v) oxide is used to catalyse the exothermic reaction between sulfur dioxide  and oxygen in the contact process. 2so2  +  o2    2so3   the rate of this reaction can be increased either by using a catalyst or by increasing the  temperature. explain why a catalyst is used and not a higher temperature.   ...    ...    ... ..  [2]  (d)  the oxidation states of vanadium in its compounds are v(+5), v(+4), v(+3) and v(+2).   the vanadium( iii) ion can behave as a reductant or an oxidant.  (i)  indicate on the following equation which reactant is the oxidant. 2v3+  +  zn  \u2192  2v2+  +  zn2+ [1]  (ii)  which change in the following equation is oxidation?   explain your choice. v3+  +  fe3+  \u2192  v4+  +  fe2+   . ...   . .  [2] [total: 8] 5  reactive metals tend to have unreactive compounds. the following is part of the reactivity  series.  sodium most reactive  calcium zinc copper silver least reactive  (a)  sodium hydroxide and sodium carbonate do not decompose when heated.   the corresponding calcium compounds do decompose when heated.   complete the following equations. calcium carbonate  \u2192 +   ca(oh) 2  \u2192    +   [2]",
            "6": "6 0620/31/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (b)  all nitrates decompose when heated.  (i)  the equation for the thermal decomposition of silver( i) nitrate is given below. 2agno3  \u2192  2ag   +   2no2  +  o2  what are the products formed when copper( ii) nitrate is heated?   . .  [1]  (ii)  complete the equation for the action of heat on sodium nitrate. ..nano3  \u2192    +   [2]  (c)  which of the metals in the list on page 5 have oxides which are not reduced by carbon?   ... ..  [1]  (d)  choose from the list on page 5, metals whose ions would react with zinc.   ... ..  [2] [total: 8] 6  butane is an alkane. it has the following structural formula. c hh hh c hhc hhc hh  (a)  the equation for the complete combustion of butane is given below. insert the two  missing volumes. 2c4h10(g)  +  13o2(g)  \u2192  8co2(g)  +  10h2o(g)  .. .. 40 volume of gas  / cm3 [2]  (b)  butane reacts with chlorine to form two isomers of chlorobutane.  (i)  what type of reaction is this?   . .  [1]  (ii) explain the term isomer .   . ...   . .  [2]",
            "7": "7 0620/31/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (iii)  draw the structural formulae of these two chlorobutanes. [2]  (c)  one of the chlorobutanes reacts with sodium hydroxide to form butan-1-ol. butan-1-ol  can be oxidised to a carboxylic acid.  (i)  state a reagent, other than oxygen, which will oxidise butan-1-ol to a carboxylic acid.   . .  [1]  (ii)  name the carboxylic acid formed.   . .  [1]  (iii)  butan-1-ol reacts with ethanoic acid to form an ester. name this ester and give its  structural formula showing all the individual bonds.  name   ...  [1 ]  structural formula [2] [total: 12]",
            "8": "8 0620/31/m/j/12 \u00a9 ucles 2012for examiner\u2019s use7  plastics are polymers. they are formed from their monomers by polymerisation.  (a)  two methods for the disposal of waste plastics are  \u25cf burning  \u25cf recycling.  describe one advantage and one disadvantage of each method.  burning  ..   ...    ...   recycling  ...    ...    ... ..  [4]  (b) (i)   there are two types of polymerisation reaction. give their names and explain the  differences between them.   . ...   . ...   . ...   . .  [4]  (ii)  give the structural formula of a polymer which is formed from two different monomers. [2] [total: 10]",
            "9": "9 0620/31/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use8  iron and steel rust when exposed to water and oxygen. rust is hydrated iron( iii) oxide.  (a)  the following cell can be used to investigate rusting. \u2013 +v oxygen bubbled on to electrode iron electrode b iron electrode awater iron( iii) oxide (rust)electron flow  (i)  what is a cell?   . ...   . .  [2]  (ii)  which electrode will be oxidised and become smaller? explain your choice.   . ...   . ...   . .  [3]  (iii)  what measurements would you need make to \ufb01 nd the rate of rusting of the electrode  you have chosen in (ii)?   . ...   . .  [2]  (iv)  suggest an explanation why the addition of salt to the water increases the rate of  rusting.   . .  [1]",
            "10": "10 0620/31/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (b)  a sample of rust had the following composition:  51.85  g of iron 22.22  g of oxygen 16.67  g of water.  calculate the following and then write the formula for this sample of rust. number of moles of iron atoms, fe =  ... [1] number of moles of oxygen atoms, o =  ... [1] number of moles of water molecules, h 2o =  ... [1]  simplest mole ratio fe  : o : h2o is  .. : .. : ..  formula for this sample of rust is ... [1] [total: 12]",
            "11": "11 0620/31/m/j/12blank page \u00a9 ucles 2012",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/31/m/j/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s12_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) may/june 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib12 06_0620_32/3rp\u00a9 ucles 2012 *7023052942* for examiner\u2019s use 1 2 3 4 5 678 total",
            "2": "2 0620/32/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  the table below includes information about some of the elements in period 2. element carbon nitrogen \ufb02 uorine neon symbol c n f ne structure macromolecular simple molecules n2simple molecules f2single atoms ne boiling point  / \u00b0c 4200 \u2013196 \u2013188 \u2013246  (a) why does neon exist as single atoms but \ufb02 uorine exists as molecules?   ...    ... ..  [2]  (b)  what determines the order of the elements in a period?   ... ..  [1]  (c)  when liquid nitrogen boils the following change occurs. n2(l) \u2192 n2(g)   the boiling point of nitrogen is very low even though the bond between the atoms in a  nitrogen molecule is very strong. suggest an explanation.   ...    ... ..  [2]  (d)  draw a diagram showing the arrangement of the outer shell (valency) electrons in a  molecule of nitrogen. [2] [total: 7]",
            "3": "3 0620/32/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  diamond and graphite are different forms of the same element, carbon.   explain the following in terms of their structure.  (a)  graphite is a soft material which is used as a lubricant.   ...    ... ..  [2]  (b)  diamond is a very hard material which is used for drilling and cutting.   ...    ... ..  [2]  (c)  graphite is a good conductor of electricity and diamond is a poor conductor.   ...    ...    ... ..  [2] [total: 6] 3  the uses of a substance are determined by its properties.  (a)  plastics are poor conductors of electricity. they are used as insulation for electric cables.   which other two properties of plastics make them suitable for this purpose?   ...    ... ..  [2]  (b)  chromium is a hard, shiny metal. suggest two reasons why chromium is used to  electroplate steel.   ...    ... ..  [2]  (c)  why is aluminium used extensively in the manufacture of aeroplanes?   ...    ... ..  [2]",
            "4": "4 0620/32/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (d)  why is copper a suitable material from which to make cooking utensils? heatcopper cookingutensil food   ...    ... ..  [2]  (e)  describe the bonding in a typical metal.   ...    ...    ... ..  [2] [total: 10] 4  the ore of aluminium is bauxite which is impure aluminium oxide. alumina, pure aluminium  oxide, is obtained from bauxite.   aluminium is formed at the cathode when a molten mixture of alumina and cryolite, na3al f6,  is electrolysed.  (a) (i)  name two products formed at the anode in this electrolysis.   . .  [2]  (ii)  all the aluminium formed comes from the alumina not the cryolite.  suggest two reasons why the electrolyte must contain cryolite.   . ...   . .  [2]  (iii)  the major impurity in bauxite is iron( iii) oxide. iron( iii) oxide is basic, aluminium  oxide is amphoteric. explain how aqueous sodium hydroxide can be used to separate them.   . ...   . ...   . .  [2]",
            "5": "5 0620/32/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  the puri \ufb01 cation of bauxite uses large amounts of sodium hydroxide.  (i)  describe the chemistry of how sodium hydroxide is made from concentrated aqueous  sodium chloride. the description must include at least one ionic equation.   . ...   . ...   . ...   . ...   . .  [5]  (ii)  making sodium hydroxide from sodium chloride produces two other chemicals.  name these two chemicals and state one use of each chemical.  chemical   use  .   chemical   use  ...  [2] [total: 13] 5  islay is an island off the west coast of scotland. the main industry on the island is making  ethanol from barley.   barley contains the complex carbohydrate, starch. enzymes catalyse the hydrolysis of starch  to a solution of glucose.  (a) (i)  draw the structure of the starch.   glucose can be represented by                              [2]ho oh",
            "6": "6 0620/32/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (ii)  enzymes can catalyse the hydrolysis of starch. name another catalyst for this  reaction.   . .  [1]  (iii)  both starch and glucose are carbohydrates. name the elements found in all  carbohydrates.   . ...   . .  [1]  (b)  yeast cells are added to the aqueous glucose. fermentation produces a solution  containing up to 10  % of ethanol.  (i)  complete the word equation for the fermentation of glucose. glucose  \u2192  ..  +  .. [1]  (ii)  explain why is it necessary to add yeast and suggest why the amount of yeast in the  mixture increases.   . ...   . ...   . .  [2]  (iii)  fermentation is carried out at 35  \u00b0c. for many reactions a higher temperature would  give a faster reaction. why is a higher temperature not used in this process?   . ...   . .  [2]  (c)  the organic waste, the residue of the barley and yeast, is disposed of through a pipeline  into the sea. in the future this waste will be converted into biogas by the anaerobic respiration of bacteria. biogas, which is mainly methane, will supply most of the island\u2019s energy.  (i)  anaerobic means in the absence of oxygen. suggest an explanation why oxygen  must be absent.   . .  [1]  (ii)  the obvious advantage of converting the waste into methane is economic.   suggest two other advantages.   . ...   . .  [2] [total: 12]",
            "7": "7 0620/32/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use6  a length of magnesium ribbon was added to 50  cm3 of sulfuric acid, concentration 1.0  mol  / dm3. the time taken for the magnesium to react was measured. the experiment was  repeated with the same volume of different acids. in all these experiments, the acid was in excess and the same length of magnesium ribbon was used.  (a) experiment acidconcentration in mol  / dm3 time  / s a sulfuric acid 1.0 20 b propanoic acid 0.5 230 c hydrochloric acid 1.0 40d hydrochloric acid 0.5 80  (i)  write these experiments in order of reaction speed. give the experiment with the  fastest speed \ufb01 rst.   . .  [1]  (ii)  give reasons for the order you have given in (i).   . ...   . ...   . ...   . ...   . ...   . .  [5]  (b)  suggest two changes to experiment c which would increase the speed of the reaction  and explain why the speed would increase. the volume of the acid, the concentration of the acid and the mass of magnesium used were kept the same.  change 1   ...  explanation  . ..   ...   change 2   ...  explanation  . ..   ... ..  [5] [total: 11]",
            "8": "8 0620/32/m/j/12 \u00a9 ucles 2012for examiner\u2019s use7  the alkenes are unsaturated hydrocarbons. they form a homologous series, the members of  which have similar chemical properties:  \u25cf easily oxidised  \u25cf addition reactions  \u25cf polymerisation  \u25cf combustion.  (a)  all the alkenes have the same empirical formula.  (i) state their empirical formula.     ..  [1]  (ii) why is the empirical formula the same for all alkenes?     ..  [1]  (b)  alkenes can be oxidised to carboxylic acids by boiling with aqueous potassium  manganate(v ii).  (i)  pent-2-ene, ch3\u2013ch2\u2013ch=ch\u2013ch3, oxidises to ch3\u2013ch2\u2013cooh and ch3cooh.   name these two acids.  ch3\u2013ch2\u2013cooh  ...  ch3cooh   [2]  (ii)  most alkenes oxidise to two carboxylic acids. deduce the formula of an alkene which  forms only one carboxylic acid. [1]  (c)  complete the following equations for the addition reactions of propene.  (i)  ch3\u2013ch=ch2  +  br2   \u2192   [1]  (ii)  ch3\u2013ch=ch2  +  h2o  \u2192   [1]  (d)  draw the structural formula of poly(propene) [2]",
            "9": "9 0620/32/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (e)  0.01 moles of an alkene needed 2.4  g of oxygen for complete combustion. 2.2  g of carbon  dioxide were formed. determine the following mole ratio.  moles of alkene : moles of o2 : moles of co2   from this ratio determine the formula of the alkene.   ... ..  [3]  write an equation for the complete combustion of this alkene.  ... ..  [1] [total: 13] 8  ethylamine, ch 3\u2013ch2\u2013nh2, is a base which has similar properties to ammonia.  (a)  in aqueous ethylamine, there is the following equilibrium. ch3\u2013ch2\u2013nh2  +  h2o    ch3\u2013ch2\u2013nh3+  +  oh\u2013   explain why water is behaving as an acid in this reaction.   ... ..  [1]  (b)  given aqueous solutions of ethylamine and sodium hydroxide, describe how you could  show that ethylamine is a weak base like ammonia and not a strong base like sodium hydroxide.   ...    ...    ... ..  [3]  (c)   ethylamine, like ammonia, reacts with acids to form salts. ch 3\u2013ch2\u2013nh2  +   hc l  \u2192  ch3\u2013ch2\u2013nh3cl  ethylammonium chloride   suggest how you could displace ethylamine from the salt, ethylammonium chloride.   ...    ... ..  [2]",
            "10": "10 0620/32/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (d)  explain the chemistry of the following reaction:   when aqueous ethylamine is added to aqueous iron( iii) chloride, a brown precipitate is  formed.   ...    ... ..  [2] [total: 8]",
            "11": "11 0620/32/m/j/12blank page \u00a9 ucles 2012",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/32/m/j/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s12_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) may/june 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib12 06_0620_33/fp\u00a9 ucles 2012 *2925136620* for examiner\u2019s use 1 2 3 4 5 678 total",
            "2": "2 0620/33/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  the table below includes information about some of the elements in period 2. element carbon nitrogen \ufb02 uorine neon symbol c n f ne structure macromolecular simple molecules n2simple molecules f2single atoms ne boiling point  / \u00b0c 4200 \u2013196 \u2013188 \u2013246  (a) why does neon exist as single atoms but \ufb02 uorine exists as molecules?   ...    ... ..  [2]  (b)  what determines the order of the elements in a period?   ... ..  [1]  (c)  when liquid nitrogen boils the following change occurs. n2(l) \u2192 n2(g)   the boiling point of nitrogen is very low even though the bond between the atoms in a  nitrogen molecule is very strong. suggest an explanation.   ...    ... ..  [2]  (d)  draw a diagram showing the arrangement of the outer shell (valency) electrons in a  molecule of nitrogen. [2] [total: 7]",
            "3": "3 0620/33/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  diamond and graphite are different forms of the same element, carbon.   explain the following in terms of their structure.  (a)  graphite is a soft material which is used as a lubricant.   ...    ... ..  [2]  (b)  diamond is a very hard material which is used for drilling and cutting.   ...    ... ..  [2]  (c)  graphite is a good conductor of electricity and diamond is a poor conductor.   ...    ...    ... ..  [2] [total: 6] 3  the uses of a substance are determined by its properties.  (a)  plastics are poor conductors of electricity. they are used as insulation for electric cables.   which other two properties of plastics make them suitable for this purpose?   ...    ... ..  [2]  (b)  chromium is a hard, shiny metal. suggest two reasons why chromium is used to  electroplate steel.   ...    ... ..  [2]  (c)  why is aluminium used extensively in the manufacture of aeroplanes?   ...    ... ..  [2]",
            "4": "4 0620/33/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (d)  why is copper a suitable material from which to make cooking utensils? heatcopper cookingutensil food   ...    ... ..  [2]  (e)  describe the bonding in a typical metal.   ...    ...    ... ..  [2] [total: 10] 4  the ore of aluminium is bauxite which is impure aluminium oxide. alumina, pure aluminium  oxide, is obtained from bauxite.   aluminium is formed at the cathode when a molten mixture of alumina and cryolite, na3al f6,  is electrolysed.  (a) (i)  name two products formed at the anode in this electrolysis.   . .  [2]  (ii)  all the aluminium formed comes from the alumina not the cryolite.  suggest two reasons why the electrolyte must contain cryolite.   . ...   . .  [2]  (iii)  the major impurity in bauxite is iron( iii) oxide. iron( iii) oxide is basic, aluminium  oxide is amphoteric. explain how aqueous sodium hydroxide can be used to separate them.   . ...   . ...   . .  [2]",
            "5": "5 0620/33/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  the puri \ufb01 cation of bauxite uses large amounts of sodium hydroxide.  (i)  describe the chemistry of how sodium hydroxide is made from concentrated aqueous  sodium chloride. the description must include at least one ionic equation.   . ...   . ...   . ...   . ...   . .  [5]  (ii)  making sodium hydroxide from sodium chloride produces two other chemicals.  name these two chemicals and state one use of each chemical.  chemical   use  .   chemical   use  ...  [2] [total: 13] 5  islay is an island off the west coast of scotland. the main industry on the island is making  ethanol from barley.   barley contains the complex carbohydrate, starch. enzymes catalyse the hydrolysis of starch  to a solution of glucose.  (a) (i)  draw the structure of the starch.   glucose can be represented by                              [2]ho oh",
            "6": "6 0620/33/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (ii)  enzymes can catalyse the hydrolysis of starch. name another catalyst for this  reaction.   . .  [1]  (iii)  both starch and glucose are carbohydrates. name the elements found in all  carbohydrates.   . ...   . .  [1]  (b)  yeast cells are added to the aqueous glucose. fermentation produces a solution  containing up to 10  % of ethanol.  (i)  complete the word equation for the fermentation of glucose. glucose  \u2192  ..  +  .. [1]  (ii)  explain why is it necessary to add yeast and suggest why the amount of yeast in the  mixture increases.   . ...   . ...   . .  [2]  (iii)  fermentation is carried out at 35  \u00b0c. for many reactions a higher temperature would  give a faster reaction. why is a higher temperature not used in this process?   . ...   . .  [2]  (c)  the organic waste, the residue of the barley and yeast, is disposed of through a pipeline  into the sea. in the future this waste will be converted into biogas by the anaerobic respiration of bacteria. biogas, which is mainly methane, will supply most of the island\u2019s energy.  (i)  anaerobic means in the absence of oxygen. suggest an explanation why oxygen  must be absent.   . .  [1]  (ii)  the obvious advantage of converting the waste into methane is economic.   suggest two other advantages.   . ...   . .  [2] [total: 12]",
            "7": "7 0620/33/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use6  a length of magnesium ribbon was added to 50  cm3 of sulfuric acid, concentration 1.0  mol  / dm3. the time taken for the magnesium to react was measured. the experiment was  repeated with the same volume of different acids. in all these experiments, the acid was in excess and the same length of magnesium ribbon was used.  (a) experiment acidconcentration in mol  / dm3 time  / s a sulfuric acid 1.0 20 b propanoic acid 0.5 230 c hydrochloric acid 1.0 40d hydrochloric acid 0.5 80  (i)  write these experiments in order of reaction speed. give the experiment with the  fastest speed \ufb01 rst.   . .  [1]  (ii)  give reasons for the order you have given in (i).   . ...   . ...   . ...   . ...   . ...   . .  [5]  (b)  suggest two changes to experiment c which would increase the speed of the reaction  and explain why the speed would increase. the volume of the acid, the concentration of the acid and the mass of magnesium used were kept the same.  change 1   ...  explanation  . ..   ...   change 2   ...  explanation  . ..   ... ..  [5] [total: 11]",
            "8": "8 0620/33/m/j/12 \u00a9 ucles 2012for examiner\u2019s use7  the alkenes are unsaturated hydrocarbons. they form a homologous series, the members of  which have similar chemical properties:  \u25cf easily oxidised  \u25cf addition reactions  \u25cf polymerisation  \u25cf combustion.  (a)  all the alkenes have the same empirical formula.  (i) state their empirical formula.     ..  [1]  (ii) why is the empirical formula the same for all alkenes?     ..  [1]  (b)  alkenes can be oxidised to carboxylic acids by boiling with aqueous potassium  manganate(v ii).  (i)  pent-2-ene, ch3\u2013ch2\u2013ch=ch\u2013ch3, oxidises to ch3\u2013ch2\u2013cooh and ch3cooh.   name these two acids.  ch3\u2013ch2\u2013cooh  ...  ch3cooh   [2]  (ii)  most alkenes oxidise to two carboxylic acids. deduce the formula of an alkene which  forms only one carboxylic acid. [1]  (c)  complete the following equations for the addition reactions of propene.  (i)  ch3\u2013ch=ch2  +  br2   \u2192   [1]  (ii)  ch3\u2013ch=ch2  +  h2o  \u2192   [1]  (d)  draw the structural formula of poly(propene) [2]",
            "9": "9 0620/33/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (e)  0.01 moles of an alkene needed 2.4  g of oxygen for complete combustion. 2.2  g of carbon  dioxide were formed. determine the following mole ratio.  moles of alkene : moles of o2 : moles of co2   from this ratio determine the formula of the alkene.   ... ..  [3]  write an equation for the complete combustion of this alkene.  ... ..  [1] [total: 13] 8  ethylamine, ch 3\u2013ch2\u2013nh2, is a base which has similar properties to ammonia.  (a)  in aqueous ethylamine, there is the following equilibrium. ch3\u2013ch2\u2013nh2  +  h2o    ch3\u2013ch2\u2013nh3+  +  oh\u2013   explain why water is behaving as an acid in this reaction.   ... ..  [1]  (b)  given aqueous solutions of ethylamine and sodium hydroxide, describe how you could  show that ethylamine is a weak base like ammonia and not a strong base like sodium hydroxide.   ...    ...    ... ..  [3]  (c)   ethylamine, like ammonia, reacts with acids to form salts. ch 3\u2013ch2\u2013nh2  +   hc l  \u2192  ch3\u2013ch2\u2013nh3cl  ethylammonium chloride   suggest how you could displace ethylamine from the salt, ethylammonium chloride.   ...    ... ..  [2]",
            "10": "10 0620/33/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (d)  explain the chemistry of the following reaction:   when aqueous ethylamine is added to aqueous iron( iii) chloride, a brown precipitate is  formed.   ...    ... ..  [2] [total: 8]",
            "11": "11 0620/33/m/j/12blank page \u00a9 ucles 2012",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/33/m/j/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s12_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test may/june 2012  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib12 06_0620_51/3rp\u00a9 ucles 2012 *4263914068* for examiner\u2019s use total",
            "2": "2 0620/51/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  you are going to investigate the reaction between aqueous lead nitrate and aqueous  potassium chloride.  read all the instructions below carefully before starting the experiment.  instructions   you are going to carry out one experiment.  (a) experiment   using the measuring cylinder, pour 3  cm3 of the aqueous lead nitrate provided into  each of the six test-tubes in the test-tube rack. label the test-tubes 1, 2, 3, 4, 5 and 6 respectively.   fill the burette with the aqueous potassium chloride provided to the 0.0  cm3 mark.  from the burette add 1.0  cm3 of aqueous potassium chloride to test-tube 1.  add 2.0  cm3 of aqueous potassium chloride to test-tube 2.   add 4.0  cm3, 5.0  cm3, 6.0  cm3 and 7.0  cm3 of aqueous potassium chloride to test-tubes 3,  4, 5 and 6 respectively.   using a glass rod carefully stir the contents of each of the test-tubes. leave the contents of the test-tubes to stand for 10 minutes.   you should start question 2 while waiting for the solid in the test-tubes to settle.   after 10 minutes, use a ruler to measure the height of the solid in each test-tube. record your results in the table. test-tube numbervolume of aqueous potassium chloride  / cm3 height of solid  / mm 1 23456 [4]",
            "3": "3 0620/51/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  plot your results on the grid below. draw a line graph. 01234 volume of aqueous potassium chloride  / cm3height of solid  / mm 5678 [4]",
            "4": "4 0620/51/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (c)  from your graph , \ufb01 nd the height of the solid formed when 3.5  cm3 of aqueous potassium  chloride is added to 3  cm3 of aqueous lead nitrate.   show clearly on the graph  how you obtained your answer.   ... ..  [3]  (d)  what type of chemical reaction occurs when aqueous potassium chloride reacts with  aqueous lead nitrate?   ... ..  [1]  (e) describe the trend in the heights of the solids in test-tubes 1 to 6.   ...    ...    ... ..  [2]  (f)  predict what would happen if the experiment were continued using three furthertest-tubes with 8  cm3, 9  cm3 and 10  cm3 of aqueous potassium chloride. explain your  answer.   ...    ...    ... ..  [2]  (g)  what difference would be observed if the experiment was repeated using aqueous silver nitrate and aqueous potassium iodide?   ...    ... ..  [1]  (h)  explain one improvement you could make to the experiment to obtain more accurate  results.  improvement  .   explanation  . ..   ... ..  [2] [total: 19]",
            "5": "5 0620/51/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  you are provided with solid w.   carry out the following tests on w, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solid w (a)  describe the appearance of solid w.   [1]  use a spatula to place about one spatula  measure of w into each of four test-tubes to  carry out the tests in (b). (b) (i)   heat solid w gently and then strongly.    leave the mixture to cool for \ufb01 ve  minutes. add about 2  cm3 of dilute  hydrochloric acid. test the gas given off with a lighted splint.  (ii)  add about 2  cm3 of dilute hydrochloric  acid to solid w.    test the gas given off.  (iii)  to solid w, add about 5  cm3 of  aqueous copper sulfate.    heat the mixture gently.  (iv)  to solid w, add one spatula measure  of ammonium chloride and shake the test-tube. heat the mixture gently. test the gas given off with damp ph indicator paper. .   [2] .  [2]  .   [3]  .   [2]  .   [2] tests on aqueous w (c)  pour 10  cm3 of distilled water into a boiling  tube. measure and record the temperature  of the water.   add the rest of solid w to the water and  stir with the thermometer. measure and record the temperature of the solution after one minute.   use ph indicator paper to record the ph of the solution.  [2]   [1]   [1]",
            "6": "6 0620/51/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (d)  identify the gas given off in test (b)(ii) .   ... ..  [1]  (e)  identify the gas given off in test (b)(iv) .   ... ..  [1]  (f)  what type of change occurs when solid w dissolves in water in test (c)?   ... ..  [1]  (g)  what conclusions can you draw about solid w?   ...    ... ..  [2] [total: 21]",
            "7": "7 0620/51/m/j/12blank page \u00a9 ucles 2012",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/51/m/j/12notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2012"
        },
        "0620_s12_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test may/june 2012  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib12 06_0620_52/rp\u00a9 ucles 2012 *1869046502* for examiner\u2019s use total",
            "2": "2 0620/52/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  you are going to investigate what happens when two different solids, c and d, dissolve in  water.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   place the polystyrene cup in the 250  cm3 beaker for support.   use a measuring cylinder to pour 25  cm3 of distilled water into the polystyrene cup.  measure the temperature of the water and record it in the table below.   add all of solid c to the water, start the timer and stir the mixture with the thermometer.   measure the temperature of the solution every 30 seconds for three minutes. record  your results in the table. time  / s 0 30 60 90 120 150 180 temperature of solution  / \u00b0c [2]  (b)  experiment 2   empty the polystyrene cup and rinse it with water.   use a measuring cylinder to pour 25  cm3 of distilled water into the polystyrene cup.  measure the temperature of the water and record it in the table below.   add all of solid d to the water, start the timer and stir the mixture with the thermometer.   measure the temperature of the solution every 30 seconds for three minutes. record  your results in the table. time  / s 0 30 60 90 120 150 180 temperature of solution  / \u00b0c [2]",
            "3": "3 0620/52/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label your graphs. 0 30 60 90 120 150 180 time  / stemperature of solution  / \u00b0c [6]  (d) (i)   from your graph , deduce the temperature of the solution in experiment 1 after 45 seconds.   show clearly on the graph  how you worked out your answer.  .. \u00b0c [2]  (ii)  from your graph , deduce how long it takes for the initial  temperature of the solution  in experiment 2 to change by 1  \u00b0c.   show clearly on the graph  how you worked out your answer.  .. s [2]",
            "4": "4 0620/52/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (e)  what type of change occurs when substance d dissolves in water?   ... ..  [1]  (f)  suggest and explain the effect on the results if experiment 1 was repeated using 50  cm3  of distilled water.   ...    ... ..  [2]  (g)  predict the temperature of the solution in experiment 2 after 1 hour. explain your answer.   ...    ... ..  [2]  (h)  when carrying out the experiments, what would be the advantage of taking the  temperature readings every 15 seconds?   ...    ... ..  [2] [total: 21]",
            "5": "5 0620/52/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  you are provided with solid e and liquid f.   carry out the following tests on e and f, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solid e (a)  describe the appearance of solid e.   [1] (b)  place half of solid e in a test-tube. heat  the test-tube gently.   test any gas given off. ..   [3] (c) (i)   add half of the remaining solid e to  about 5  cm3 of dilute sulfuric acid in a  test-tube.    allow the mixture to settle. decant off  the liquid into a test-tube.    divide the solution into two equal  portions in test-tubes. add 1  cm  depth of distilled water to eachtest-tube and shake. carry out the following tests.  (ii)   add several drops of aqueous sodium  hydroxide to the \ufb01 rst portion of the  solution and shake the test-tube.    now add excess sodium hydroxide to  the test-tube.  (iii)   add several drops of aqueous  ammonia to the second portion of the solution and shake the test-tube.    now add excess aqueous ammonia  to the test-tube. ..   [2]  ..   [2]  ..  ..  [3]",
            "6": "6 0620/52/m/j/12 \u00a9 ucles 2012for examiner\u2019s usetests observations tests on liquid f (d)  describe the appearance and smell of  liquid f.  appearance  [1]  smell ... [1] (e)  use ph indicator paper to measure the ph  of liquid f.  ph .. [1] (f)  add about 3  cm3 of liquid f to the rest of  solid e in a test-tube. leave to stand for  \ufb01 ve minutes. ..   [2]  (g)  identify solid e.   ... ..  [2]  (h)  draw one conclusion about liquid f.   ... ..  [1] [total: 19]",
            "7": "7 0620/52/m/j/12blank page \u00a9 ucles 2012",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/52/m/j/12notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2012"
        },
        "0620_s12_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test may/june 2012  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib12 06_0620_53/fp\u00a9 ucles 2012 *7620311346* for examiner\u2019s use total",
            "2": "2 0620/53/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  you are going to investigate what happens when two different solids, c and d, dissolve in  water.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   place the polystyrene cup in the 250  cm3 beaker for support.   use a measuring cylinder to pour 25  cm3 of distilled water into the polystyrene cup.  measure the temperature of the water and record it in the table below.   add all of solid c to the water, start the timer and stir the mixture with the thermometer.   measure the temperature of the solution every 30 seconds for three minutes. record  your results in the table. time  / s 0 30 60 90 120 150 180 temperature of solution  / \u00b0c [2]  (b)  experiment 2   empty the polystyrene cup and rinse it with water.   use a measuring cylinder to pour 25  cm3 of distilled water into the polystyrene cup.  measure the temperature of the water and record it in the table below.   add all of solid d to the water, start the timer and stir the mixture with the thermometer.   measure the temperature of the solution every 30 seconds for three minutes. record  your results in the table. time  / s 0 30 60 90 120 150 180 temperature of solution  / \u00b0c [2]",
            "3": "3 0620/53/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label your graphs. 0 30 60 90 120 150 180 time  / stemperature of solution  / \u00b0c [6]  (d) (i)   from your graph , deduce the temperature of the solution in experiment 1 after 45 seconds.   show clearly on the graph  how you worked out your answer.  .. \u00b0c [2]  (ii)  from your graph , deduce how long it takes for the initial  temperature of the solution  in experiment 2 to change by 1  \u00b0c.   show clearly on the graph  how you worked out your answer.  .. s [2]",
            "4": "4 0620/53/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (e)  what type of change occurs when substance d dissolves in water?   ... ..  [1]  (f)  suggest and explain the effect on the results if experiment 1 was repeated using 50  cm3  of distilled water.   ...    ... ..  [2]  (g)  predict the temperature of the solution in experiment 2 after 1 hour. explain your answer.   ...    ... ..  [2]  (h)  when carrying out the experiments, what would be the advantage of taking the  temperature readings every 15 seconds?   ...    ... ..  [2] [total: 21]",
            "5": "5 0620/53/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  you are provided with solid e and liquid f.   carry out the following tests on e and f, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solid e (a)  describe the appearance of solid e.   [1] (b)  place half of solid e in a test-tube. heat  the test-tube gently.   test any gas given off. ..   [3] (c) (i)   add half of the remaining solid e to  about 5  cm3 of dilute sulfuric acid in a  test-tube.    allow the mixture to settle. decant off  the liquid into a test-tube.    divide the solution into two equal  portions in test-tubes. add 1  cm  depth of distilled water to eachtest-tube and shake. carry out the following tests.  (ii)   add several drops of aqueous sodium  hydroxide to the \ufb01 rst portion of the  solution and shake the test-tube.    now add excess sodium hydroxide to  the test-tube.  (iii)   add several drops of aqueous  ammonia to the second portion of the solution and shake the test-tube.    now add excess aqueous ammonia  to the test-tube. ..   [2]  ..   [2]  ..  ..  [3]",
            "6": "6 0620/53/m/j/12 \u00a9 ucles 2012for examiner\u2019s usetests observations tests on liquid f (d)  describe the appearance and smell of  liquid f.  appearance  [1]  smell ... [1] (e)  use ph indicator paper to measure the ph  of liquid f.  ph .. [1] (f)  add about 3  cm3 of liquid f to the rest of  solid e in a test-tube. leave to stand for  \ufb01 ve minutes. ..   [2]  (g)  identify solid e.   ... ..  [2]  (h)  draw one conclusion about liquid f.   ... ..  [1] [total: 19]",
            "7": "7 0620/53/m/j/12blank page \u00a9 ucles 2012",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/53/m/j/12notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2012"
        },
        "0620_s12_qp_61.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical may/june 2012  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib12 06_0620_61/4rp\u00a9 ucles 2012 *0367948514* for examiner\u2019s use 1 23456 total",
            "2": "2 0620/61/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  a student reacted excess iron powder with sulfuric acid to prepare a solution of iron( ii)  sulfate.   the diagram shows the procedure followed in three stages. 50  cm3 of dilute sulfuric acid was measured and added to a beaker heat1iron powder was addeduntil all the sulfuric acidhad reacted the mixture wasallowed to cool2 solution ofiron( ii) sulfate3  (a)  complete the boxes to identify the pieces of apparatus labelled. [2]  (b)  how would the student know when all of the sulfuric acid had reacted? give two reasons.  1  ... .  2  ... ...  [2]  (c)  describe the effect of boiling the solution of iron( ii) sulfate for several minutes.   ...    ...    ... ..  [3] [total: 7]",
            "3": "3 0620/61/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  heat is given out when alcohols are burned.   a student used the apparatus below to \ufb01 nd the amount of heat produced when four different  alcohols, methanol, ethanol, propanol and butanol, were burned. 25  cm3 water spirit burnerboiling tubethermometer  (a)  some methanol was put into the burner. the initial temperature of the water was measured.  the burner was lit and allowed to burn for one minute. the \ufb02 ame was extinguished and  the \ufb01 nal temperature of the water was measured. the experiment was repeated with  ethanol, propanol and butanol.   use the thermometer diagrams to record the temperatures in the table on page 4. complete the table by recording the temperature rise for each alcohol.",
            "4": "4 0620/61/m/j/12 \u00a9 ucles 2012for examiner\u2019s use ch3oh c2h5oh c3h7oh c4h9ohmethanol ethanol propanol butanolthermometer diagramthermometer diagramalcohol formula temperature  / \u00b0c temperature  / \u00b0ctemperature rise  / \u00b0c 30 25 20 30 25 20 30 25 20 30 25 2030 25 20 40 35 30 50 45 40 60 55 50initial final [4]",
            "5": "5 0620/61/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  plot the results obtained on the grid and draw a straight line graph. 50 40302010 0 012345 number of carbon atoms in the alcohol formulatemperature rise  / \u00b0c [4]  (c)  from your graph , work out the temperature rise expected if the experiment was repeated  using pentanol, c5h11oh.   show clearly on the grid  how you obtained your answer.   ... ..  [3]  (d)  suggest the effect of using a copper can to contain the water instead of a boiling tube. explain your answer.   ...    ... ..  [2] [total: 13]",
            "6": "6 0620/61/m/j/12 \u00a9 ucles 2012for examiner\u2019s use3  coffee beans contain caffeine and other compounds. caffeine is soluble in water and in  trichloromethane, an organic solvent.   a student obtained crystals of caffeine by the following method.  stage 1 some coffee beans were crushed into small pieces.  stage 2  hot water was added to the crushed beans to dissolve the soluble substances.  stage 3  the crushed beans were separated from the liquid solution.  stage 4  the liquid was allowed to cool and shaken with trichloromethane to extract the  caffeine from the water.  stage 5  the caffeine was crystallised from the trichloromethane solution.  stage 6  the caffeine crystals were checked for purity.  (a)  what apparatus should be used to crush the beans in stage 1?   ... ..  [2]  (b)  how could the dissolving process in stage 2 be speeded up?   ... ..  [1]  (c)  draw a diagram of the apparatus used in stage 3. [2]  (d)  how should stage 5 be carried out?   ...    ... ..  [2]  (e)  what method could be used to check the purity of the crystals in stage 6?   ... ..  [1] [total: 8]",
            "7": "7 0620/61/m/j/12blank page \u00a9 ucles 2012 [turn over",
            "8": "8 0620/61/m/j/12 \u00a9 ucles 2012for examiner\u2019s use4  a student investigated the reaction between aqueous lead nitrate and aqueous potassium  chloride.  (a)  one experiment was carried out.   using a measuring cylinder, 3  cm3 of aqueous lead nitrate was poured into each of six test-tubes in a test-tube rack. the test-tubes were labelled a, b, c, d, e and f respectively.   a burette was \ufb01 lled with aqueous potassium chloride. a 1.0  cm3 sample of the aqueous  potassium chloride was added to test-tube a.   a 2.0  cm3 sample of aqueous potassium chloride was added to test-tube b.   a 4.0  cm3, 5.0  cm3, 6.0  cm3 and 7.0  cm3 sample of aqueous potassium chloride was added  to test-tubes c, d, e and f respectively.   using a glass rod, the contents of the test-tubes were stirred. the contents of thetest-tubes were left to stand for 10 minutes.   after 10 minutes, a ruler was used to measure the height of the solid in each test-tube. the diagrams show the six test-tubes in a rack. use a ruler to measure the height of the solid in each test-tube in the diagram. record the heights of the solid in the table. test-tube a solidbcdef test-tube numbervolume of aqueous potassium chloride  / cm3 height of solid  / mm a b c d e f [4]",
            "9": "9 0620/61/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  plot your results on the grid below. draw two intersecting straight line graphs. 25 201510 5 0 01234567 volume of aqueous potassium chloride  / cm3height of solid  / mm [4]  (c)  from your graph , \ufb01 nd the height of the solid formed when 3.5  cm3 of aqueous potassium  chloride was added to 3  cm3 of aqueous lead nitrate.    show clearly on the graph  how you obtained your answer.   ... ..  [3]  (d)  what type of chemical reaction occurs when aqueous potassium chloride reacts with aqueous lead nitrate?   ... ..  [1]  (e) (i)   compare the heights of the solids in test-tubes e and f.   . .  [1]  (ii)  suggest an explanation for the heights of the solids in (e)(i) .   . ...   . .  [1]",
            "10": "10 0620/61/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (f)  predict what would happen if the experiment were continued using three further test- tubes with 8  cm3, 9  cm3 and 10  cm3 of aqueous potassium chloride. explain your answer.   ...    ...    ... ..  [2]  (g)  what difference would be observed if the experiment was repeated using aqueous silver nitrate and aqueous potassium iodide?   ...    ... ..  [1]  (h)  explain one improvement the student could make to the experiment to obtain more  accurate results.  improvement  .   explanation  . ..   ... ..  [2] [total: 19]",
            "11": "11 0620/61/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use5  solid w was analysed. w was a carbonate salt.   the tests on solid w, and some of the observations, are in the following table. complete the  observations in the table.   do not write any conclusions in the table. tests observations tests on solid w (a)  appearance of solid w. white solid (b)  solid w was heated.   the gas given off was tested with damp  red litmus paper.gas evolved formed a white solid at the top  of the test-tube litmus paper turned blue (c)  dilute hydrochloric acid was added to solid w.   the gas given off was tested. ..  .. ... [3] (d)  dilute sodium hydroxide was added to  solid w and the mixture heated.   the gas given off was tested with damp ph indicator paper. pungent gas given off ph of gas = 10  (e)  identify the gas given off in test (d).   ... ..  [1]  (f)  what conclusions can you draw about solid w?   ... ..  [2] [total: 6]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/61/m/j/12 \u00a9 ucles 2012for examiner\u2019s use6 stop rust!   solutions of chemicals known as corrosion inhibitors are added to the water in steel radiators  to reduce rust.   you are provided with three different bottles of liquid corrosion inhibitors, r, s and t, and  some steel nails.   plan an experiment to test if these inhibitors prevent the corrosion of steel and which of these inhibitors is the most effective.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [7] [total: 7]"
        },
        "0620_s12_qp_62.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical may/june 2012  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib12 06_0620_62/4rp\u00a9 ucles 2012 *8566192908* for examiner\u2019s use 1 2345 6 7 total",
            "2": "2 0620/62/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  a student heated red crystals of hydrated cobalt( ii) chloride, coc l 2.6h2o, to obtain a sample  of water. he used two different sets of apparatus, a and b. heat heatcobalt chloride crystals cobalt chloride crystalscold water cold waterwater watera bboiling tubeboiling tube  (a)  complete the box to identify the piece of apparatus labelled. [1]  (b)  the steam could have been condensed more ef \ufb01 ciently using a condenser.   draw a labelled diagram of a condenser. [2]",
            "3": "3 0620/62/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  the colour of the solid remaining in the boiling tube after heating was blue.   predict the effect of adding water to this solid. explain your answer.  effect  .. ...  explanation  .   [2]  (d)  suggest why the boiling tube cracked using set of apparatus b but not set a.   ...    ... ..  [2] [total: 7]",
            "4": "4 0620/62/m/j/12 \u00a9 ucles 2012for examiner\u2019s use2  an experiment was carried out to measure the speed (rate) of reaction between magnesium  carbonate and excess dilute nitric acid.   50  cm3 of dilute nitric acid was poured into a conical \ufb02 ask and placed on a balance. 1.0  g of  powdered magnesium carbonate was added to the \ufb02 ask. the mass of the \ufb02 ask and contents  decreased as a gas was given off. the loss in mass was recorded every half minute for six minutes.   the results of the experiment are shown plotted on the grid below. 0.5 0.40.30.20.10.0 012345 6 time  / minutesloss in mass  / g  (a)  draw a smooth line graph through the points. [1]  (b)  which point appears to be inaccurate?   ... ..  [1]  (c)  why does the curve level out? explain your answer.   ...    ... ..  [2]  (d)  on the grid, sketch the graph you would expect if the reaction was repeated using 0.5  g  of lumps of magnesium carbonate. [2] [total: 6]",
            "5": "5 0620/62/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use3  electricity was passed through a solution of concentrated hydrochloric acid as shown below. concentrated hydrochloric acid   bubbles were observed at both electrodes.  (a)  give one other expected observation.   ... ..  [1]  (b)  label the electrodes. [1]  (c) (i)   name the gas given off at the cathode (negative electrode).   . .  [1]  (ii)  give a test for this gas.  test   .  result    [2]  (d)  suggest why, at the beginning of the electrolysis, no gas was collected at the anode (positive electrode).   ...    ... ..  [2] [total: 7]",
            "6": "6 0620/62/m/j/12 \u00a9 ucles 2012for examiner\u2019s use4  a student investigated a reaction between a solid and a liquid. the reaction produced a gas.   she wanted to know if any of the substances w, x and y were catalysts for the reaction.   firstly she carried out the reaction without any w, x or y.   then she repeated the reaction three times adding a small amount of w, x or y. in each case  she timed how long the reaction took to \ufb01 nish. the results are in the table. substance added time of reaction  / s none 277 w 266 x 279 y 78  (a)  how would the student know when the reaction had \ufb01 nished?   ... ..  [1]  (b) (i)  state the effect of each substance on the speed (rate) of the reaction.  w  . ..  x  . ...  y  ..  [ 3]  (ii)  which substance, w, x or y, is the best catalyst for this reaction?   . .  [1]  (c)  how could the student check the reliability of her results?   ...    ... ..  [2] [total: 7]",
            "7": "7 0620/62/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use5  a student investigated the temperature changes when two different solids, c and d, dissolved  in water.  two experiments were carried out.   experiment 1   using a measuring cylinder, 25  cm3 of distilled water was poured into a polystyrene cup. the  initial temperature of the water was measured.    solid c was added to the water, the timer started and the mixture stirred with a thermometer.    the temperature of the solution was measured every 30 seconds for three minutes.   (a)  use the thermometer diagrams in the table to record the temperatures. 0 30 6090 120thermometer diagramtime  / s temperature  / \u00b0c 30 25 20 30 25 20 30 25 20 30 25 20 30 25 20 15030 25 20 18030 25 20 [2]",
            "8": "8 0620/62/m/j/12 \u00a9 ucles 2012for examiner\u2019s use experiment 2   the polystyrene cup was emptied and rinsed with water. experiment 1 was repeated using  solid d instead of solid c. the temperature of the solution was measured every 30 seconds  for three minutes as before.  (b)  use the thermometer diagrams in the table to record the temperatures. 0 30 6090 120thermometer diagramtime  / s temperature  / \u00b0c 25 20 15 25 20 15 25 20 15 25 20 15 25 20 15 25 20 15 25 20 15150 180 [2]",
            "9": "9 0620/62/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label your graphs. 28 262422201816 14 0 30 60 90 120 150 180temperature of solution  / \u00b0c time  / s [6]  (d) (i)   from your graph , deduce the temperature of the solution in experiment 1 after 15 seconds.   show clearly on the graph  how you worked out your answer.  . \u00b0c [2]  (ii)  from your graph , deduce how long it takes for the initial  temperature of the solution  in experiment 2 to change by 1.5  \u00b0c.   show clearly on the graph  how you worked out your answer.  .s [2]",
            "10": "10 0620/62/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (e)  what type of change occurs when substance d dissolves in water?   ... ..  [1]  (f)  suggest the effect on the results if experiment 1 was repeated using 50  cm3 of distilled  water.   ...    ... ..  [1]  (g)  predict the temperature of the solution in experiment 2 after 1 hour. explain your answer.   ...    ... ..  [2]  (h)  when carrying out the experiments what would be the advantage of taking the temperature  readings every 15 seconds?   ...    ... ..  [2] [total: 20]",
            "11": "11 0620/62/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use6  two substances, e and f, were analysed. e was a solid compound and f was a solution of  ethanoic acid.   the tests on e and f, and some of the observations, are in the table. complete the observations  in the table.   do not write any conclusions in the table. tests observations tests on solid e (a)  appearance of solid e. green powder (b)  solid e was heated in a test-tube.   the gas given off was tested.black solid formed limewater turned milky (c) (i)  solid e was added to dilute sulfuric  acid.    the solution was divided into two  equal portions in test-tubes.  (ii)  excess aqueous sodium hydroxide  was added to the \ufb01 rst portion of the  solution.  (iii)  drops of aqueous ammonia were  added to the second portion of the solution.    excess aqueous ammonia was then  added to the mixture.effervescence and blue solution formed pale blue precipitate formed pale blue precipitate formed precipitate dissolved to form a dark blue solution tests on liquid f (d)  appearance and smell of liquid f. (e)  ph indicator paper was used to measure  the ph of liquid f. appearance ...  smell   [2]  ph   [1]  (f)  identify the gas given off in test (c)(i) .   ... ..  [1]  (g)   identify solid e.   ... ..  [2] [total: 6]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/62/m/j/12 \u00a9 ucles 2012for examiner\u2019s use7 fizzy drinks   the bubbles in \ufb01 zzy drinks are bubbles of carbon dioxide. the carbon dioxide is dissolved in  the drink under pressure.   when a bottle of \ufb01 zzy drink is opened the gas escapes and eventually the drink goes \ufb02 at.   the gas is lost more quickly if the \ufb01 zzy drink is heated.  (a) how could the acidity of the \ufb01 zzy drink be checked?   ... ..  [1]  (b)  plan an experiment to \ufb01 nd the volume of gas in a bottle of \ufb01 zzy drink.   you may use common laboratory apparatus.   ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 7]"
        },
        "0620_s12_qp_63.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical may/june 2012  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib12 06_0620_63/3rp\u00a9 ucles 2012 *1874433085* for examiner\u2019s use 1 234567 total",
            "2": "2 0620/63/m/j/12 \u00a9 ucles 2012for examiner\u2019s use1  zinc blende is an ore of zinc containing zinc sul \ufb01 de, zns.   a student attempted to obtain a sample of zinc metal from this ore. the diagram shows the  procedure followed in four stages. zincsulfatesolution dilute acidstage 1 a lump of zinc blende was heated to form zinc oxide.stage 2 the zinc oxide was crushed.stage 3 dilute acid was added.stage 4 the mixture was separated to give a solution of zinc sulfate. zincblende tripodcrucible bunsenburner  (a)  complete the box to name the apparatus used. [1]  (b)  explain why the student should have carried out stage 2 before stage 1.   ...    ... ..  [2]  (c)  identify the dilute acid used in stage 3.   ... ..  [1]  (d)  name the process used in stage 4.   ... ..  [1]  (e)  suggest how the student could have obtained a sample of zinc from the zinc sulfate solution.   ... ..  [1] [total: 6]",
            "3": "3 0620/63/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  three bottles of liquids have lost their labels.   the liquids are known to be:  pentene;  aqueous sodium iodide;  aqueous ammonia.  outline chemical tests you would do to identify and distinguish the liquid in each bottle. liquid chemical test result pentene.. .. aqueous sodium iodide aqueous ammonia [6] [total: 6]",
            "4": "4 0620/63/m/j/12 \u00a9 ucles 2012for examiner\u2019s use3  hydrogen peroxide decomposes to form oxygen. manganese( iv) oxide is a catalyst for this  reaction.   two students investigated the speed of reaction using the apparatus below.   2 g of manganese( iv) oxide powder was added to 50  cm3 of aqueous hydrogen peroxide at  20  \u00b0c. gas syringe manganese( iv) oxideaqueous hydrogen peroxide   the volume of oxygen released was measured every 20 seconds.  (a)  use the gas syringe diagrams to record the volumes in the table. time  / s gas syringe diagram volume of oxygen  / cm3 001 02 03 0 50 60 40 2001 02 03 0 50 60 40 4001 02 03 0 50 60 40 6001 02 03 0 50 60 40 8001 02 03 0 50 60 40 10001 02 03 0 50 60 40 12001 02 03 0 50 60 40 14001 02 03 0 50 60 40 [3]",
            "5": "5 0620/63/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  plot the results on the grid below. draw a smooth line graph. 70 605040302010 0 0 20 40 60 80 100 120 140volume of oxygen  / cm3 time  / s [4]  (c)  which point appears to be inaccurate? explain why.   ...    ... ..  [2]  (d)  use your graph  to \ufb01 nd the volume of oxygen produced after 12 seconds. show clearly  how you used the graph.   ... ..  [2]  (e)  why did the volume of oxygen level out after 120 seconds?   ... ..  [1]",
            "6": "6 0620/63/m/j/12 \u00a9 ucles 2012for examiner\u2019s use (f)  the experiment was repeated but the hydrogen peroxide was cooled to 10  \u00b0c before  starting.  (i)  how could the hydrogen peroxide be cooled?   . .  [1]  (ii)  sketch on the grid, on page 5, the graph you would expect for the results at 10  \u00b0c. [2] [total: 15]",
            "7": "7 0620/63/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use4  a student prepared some crystals of sodium nitrate. the following extract was taken from her  notes. preparing sodium nitrate crystalspreparing sodium nitrate crystals into a conical flask was placed 25.0into a conical flask was placed 25.0 cmcm3 of aqueous sodium hydroxide  of aqueous sodium hydroxide  and 5 drops of indicator. dilute nitric acid was added to the flask until and 5 drops of indicator. dilute nitric acid was added to the flask until  the indicator changed colour. the volume of nitric acid used was 29.0the indicator changed colour. the volume of nitric acid used was 29.0 cmcm3. .  crystals of sodium nitrate were obtained from the mixture in the flask.crystals of sodium nitrate were obtained from the mixture in the flask.  (a)  what piece of apparatus should be used to measure the aqueous sodium hydroxide?   ... ..  [1]  (b) (i)   name a suitable indicator that could be used.   . .  [1]  (ii)  this indicator would change colour from ... to ... . [1]  (c)  which solution was less concentrated? explain your answer.  solution of  .  explanation  . ..   ... ..  [2]  (d)  how could the student obtain pure crystals of sodium nitrate using this method?   ...    ...    ...    ... ..  [3] [total: 8]",
            "8": "8 0620/63/m/j/12 \u00a9 ucles 2012for examiner\u2019s use5  a mixture of two solids, g and h, was analysed. g was water-soluble and h was copper  carbonate.   the tests on the mixture and some of the observations are in the following table.   complete the observations in the table. tests observations the mixture was added to water in a boiling  tube. the mixture was shaken and \ufb01 ltered.  the \ufb01 ltrate and the residue were tested. tests on the \ufb01 ltrate (a)  to the \ufb01 ltrate, dilute nitric acid was added  followed by aqueous silver nitrate. white precipitate (b)  to the \ufb01 ltrate, dilute sulfuric acid was  added. white precipitate tests on the residue (c)  a little of the residue was put into a test-tube and dilute nitric acid added.  the gas was tested.  the contents of the test-tube were kept  for test (d)  [1] ...  [2] (d)  the contents of the test-tube were divided  into two portions.  (i)  to the \ufb01 rst portion, an excess of  aqueous sodium hydroxide was added.  (ii)  to the second portion, a few drops of  aqueous ammonia were added.    excess aqueous ammonia was then  added  [2] ...  [1] . ...  [2]  (e)  what conclusions can you draw about solid g?   ... ..  [2] [total: 10]",
            "9": "9 0620/63/m/j/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use6  electricity was passed through molten lead iodide as shown below. lead iodide toxic molten lead iodide   a purple gas was observed coming from the positive electrode (anode).  (a)  what piece of apparatus is missing from the diagram?   ... ..  [1]  (b)  clearly label the electrodes on the diagram. [1]  (c)  give one other expected observation  (i)  during the electrolysis,  ...  (ii)  when the molten lead iodide cools and solidi \ufb01 es.   . .  [2]  (d)  suggest why a stopper is not used in the top of the boiling tube.   ... ..  [1]  (e)  explain the observation at the positive electrode.   ...    ... ..  [2]  (f)  give one safety precaution necessary when carrying out this experiment.   ...    ... ..  [1] [total: 8]",
            "10": "10 0620/63/m/j/12 \u00a9 ucles 2012for examiner\u2019s use7 fertilisers   growwell and plantstrong are two different granular fertilisers.   fertilisers improve the growth of plants.   a farmer decides to buy one of these fertilisers to improve the soil on his land.   plan an investigation to \ufb01 nd out which of these fertilisers would be best for the farmer to buy,  and use, to grow beans on his land.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [7] [total: 7]",
            "11": "11 0620/63/m/j/12blank page \u00a9 ucles 2012",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/63/m/j/12blank page \u00a9 ucles 2012"
        },
        "0620_w12_qp_11.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib12 11_0620_11/3rp  \u00a9 ucles 2012  [turn over       *9334910042* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  october/november 2012       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2012 0620/11/o/n/12  1 what are the processes w, x, y and z in the following diagram?     w x  solid    liquid    gas   y z    w x y z  a condensing boiling freezing melting  b condensing freezing melting boiling  c melting boiling freezing condensing  d melting freezing condensing boiling    2 a mixture of sulfur and iron filings needs to be separated. the solubilities of sulfur and iron filings  in water and carbon disulfide are shown in the table below.     solubility  in water solubility in  carbon disulfide sulfur \u0017 \u0013  iron filings \u0017 \u0017    what are possible methods of separating the sulfur and iron filings?     using  water using  carbon disulfide using  a magnet  a \u0013 \u0013 \u0017  b \u0017 \u0013 \u0013  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0017     3 part of the instructions in an experiment reads as follows.    quickly add 50  cm3 of acid.    what is the best piece of apparatus to use?  a a burette  b a conical flask  c a measuring cylinder  d a pipette     ",
            "3": "3  \u00a9 ucles 2012 0620/11/o/n/12 [turn over  4 which statements comparing the properties of electrons, neutrons and protons are correct?     neutrons and protons are  both heavier than electrons only electrons and  neutrons are charged  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     5 which row gives the number of electrons in the outer electron shell of fluorine and of neon?      f19 9 ne20 10  a 7 8  b 7 10  c 9 8  d 9 10      6 in the molecules ch 4, hcl and h 2o, which atoms use all of their outer shell electrons in bonding?  a c and c l b c and h c cl and h d h and o     7 the table shows the electronic structures of four atoms.    atom electronic structure  w 2,1  x 2,7  y 2,8,4  z 2,8,8    which two atoms combine to form an ionic compound?  a w and x b w and y c x and y d x and z    ",
            "4": "4  \u00a9 ucles 2012 0620/11/o/n/12  8 a compound has the formula ch 3co 2h.    how should the relative molecular mass, mr, of this compound be calculated?  a 12 + 1 + 16  b 3(12 + 1) + 2(12 + 16) + 1  c (4 \u00d7 12) + (2 \u00d7 1) + 16  d (2 \u00d7 12) + (4 \u00d7 1) + (2 \u00d7 16)      9 the diagram shows the electrolysis of concentrated aqueous sodium chloride.    +\u2013positive electrodenegative electrode concentrated aqueous sodiumchloridecarbon rods     what is produced at each of the electrodes?     product at cathode product at anode  a hydrogen chlorine  b hydrogen oxygen  c sodium chlorine  d sodium oxygen     ",
            "5": "5  \u00a9 ucles 2012 0620/11/o/n/12 [turn over  10 the diagram shows an electrolysis experiment using metals x and y as electrodes.    aqueous solution xy+\u2013     one of the metals becomes coated with copper.    which metal becomes coated and which aqueous solution is used?     metal aqueous  solution  a x crc l 3  b x cuc l 2  c y crc l 3  d y cuc l 2     11 the diagrams show the difference in energies  of the reactants and products in two types of  reaction.    energydiagram 1 heat taken in products reactantsenergydiagram 2 heat given out reactants products     which diagram and which type of energy change apply to a fuel burning in air?     diagram type of energy change  a 1 endothermic  b 1 exothermic  c 2 endothermic  d 2 exothermic   ",
            "6": "6  \u00a9 ucles 2012 0620/11/o/n/12  12 the diagram shows a match.        by striking the match, a chemical reaction takes place.    which statements about the chemical reaction are correct?     type of reaction reason  a endothermic because energy is used to strike the match  b endothermic because energy is given out as the match burns  c exothermic because energy is used to strike the match  d exothermic because energy is given out as the match burns      13 separate samples of anhydrous and hydrated copper( ii) sulfate are heated.    heatanhydrous copper( ii) sulfate heathydrated copper( ii) sulfate     which shows the correct colour changes?     anhydrous copper( ii) sulfate hydrated copper( ii) sulfate  a blue to white white to blue  b no change blue to white  c white to blue blue to white  d white to blue no change     14 which change is an oxidation?  a feo to fe 2o3  b fe2o3 to feo  c h2o2 to h 2o  d h2o to h 2    ",
            "7": "7  \u00a9 ucles 2012 0620/11/o/n/12 [turn over  15 which change does not increase the speed of reaction between zinc and hydrochloric acid?  a adding a catalyst  b decreasing the particle size of the zinc  c decreasing the temperature  d using more concentrated acid      16 which of these pairs of aqueous ions both  react with dilute sulfuric acid to give a visible result?  a ba2+ and c l \u2212  b ba2+ and co 32\u2212  c nh 4+ and c l \u2212  d nh 4+ and co 32\u2212     17 element x forms an acidic, covalent oxide.    which row shows how many electrons there could be in the outer shell of an atom of x?     1 2 6 7  a \u0013 \u0013 \u0017 \u0017  b \u0013 \u0017 \u0013 \u0017  c \u0017 \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017 \u0013      18 barium hydroxide is an alkali. it reacts with hydrochloric acid.    how does the ph of the hydrochloric acid change as an excess of aqueous barium hydroxide is  added?  a the ph decreases from 14 and becomes constant at 7.  b the ph decreases from 14 to about 1.  c the ph increases from 1 and becomes constant at 7.  d the ph increases from 1 to about 14.      19 a compound is a salt if it  a can neutralise an acid.  b contains more than one element.  c dissolves in water.  d is formed when an acid reacts with a base.   ",
            "8": "8  \u00a9 ucles 2012 0620/11/o/n/12  20 the diagram shows an outline of the periodic table.    x wy uv     which of the elements u, v, w, x and y would react together in the ratio of 1  : 1?  a u and x b u and y c v and y d w and x      21 the element rubidium, rb, is immediately below potassium in the periodic table.    it reacts with bromine to form the compound rubidium bromide.    which descriptions of this compound are correct?     type of bond formula colour  a covalent rbbr brown  b covalent rbbr 2 white  c ionic rbbr white  d ionic rbbr 2 brown    22 the table gives information about four elements.    which element is a transition metal?     colour  of element electrical  conductivity  of element colour  of oxide  a black high colourless  b colourless low white  c grey high red  d yellow low colourless ",
            "9": "9  \u00a9 ucles 2012 0620/11/o/n/12 [turn over  23 why are weather balloons filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen.  c helium is more dense than hydrogen.  d helium is unreactive.      24 some properties of aluminium are listed.    1 it has mechanical strength.  2 it conducts heat. 3 it is resistant to corrosion. 4 it has a low density.    which properties make aluminium useful for making the bodies of aircraft?  a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4      25 brass is used in electrical equipment.    it contains two \u2026\u20261\u2026\u2026 elements. together they form \u2026\u20262\u2026\u2026 .    which words correctly complete gaps 1 and 2?     1 2  a metallic a covalent compound  b metallic an alloy  c non-metallic a covalent compound  d non-metallic an alloy    ",
            "10": "10  \u00a9 ucles 2012 0620/11/o/n/12  26 the basic oxygen process converts iron into steel.    in step 1, oxygen is blown into impure molten iron.    in step 2, oxides are removed by reaction with calcium oxide.    waste  gases oxygen molten iron  and  calcium oxide     which chemical reaction takes place in step 1 and which type of oxides are removed in step 2?     chemical reaction  in step 1 type of oxides removed  in step 2  a carbon is converted to carbon dioxide acidic  b carbon is converted to carbon dioxide basic  c iron is converted to iron( iii) oxide acidic  d iron is converted to iron( iii) oxide basic     27 pieces of copper, iron, magnesium and zinc ar e added to separate test-tubes containing dilute  hydrochloric acid.    which test-tube contains iron and dilute hydrochloric acid?    a b c d      ",
            "11": "11  \u00a9 ucles 2012 0620/11/o/n/12 [turn over  28 which processes are used in the treatment of water?  a filtration and chlorination  b filtration and reduction  c neutralisation and chlorination  d neutralisation and reduction      29 a factory burns coal with a high sulfur content.    which pollutant is most  likely to lead to the death of trees?  a carbon dioxide  b carbon monoxide  c lead compounds  d sulfur dioxide     30 what is the correct order of abundance of the gases in the air?  a nitrogen \u2192 oxygen \u2192 argon \u2192 carbon dioxide  b nitrogen \u2192 oxygen \u2192 carbon dioxide \u2192 argon  c oxygen \u2192 nitrogen \u2192 argon \u2192 carbon dioxide  d oxygen \u2192 nitrogen \u2192 carbon dioxide \u2192 argon    31 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change ",
            "12": "12  \u00a9 ucles 2012 0620/11/o/n/12  32 the diagram shows two substances, x and y, being heated together.    damp universal indicato r paper substances x and y heat    the universal indicator paper turns blue during the experiment.    what are substances x and y?  a ammonium nitrate and hydrochloric acid  b ammonium nitrate and sodium hydroxide  c sodium carbonate and hydrochloric acid  d sodium carbonate and sodium hydroxide     33 carbon dioxide is produced when dilute hydrochloric acid reacts with  a calcium sulfate.  b carbon.  c copper( ii) carbonate.  d limewater.     ",
            "13": "13  \u00a9 ucles 2012 0620/11/o/n/12 [turn over  34 a student is asked to draw a diagram showing the uses of limestone.    limestone making  cement making lime added, with hematite,  to a blast furnace 1 2  3      which numbered lines show a correct use of limestone?  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3     35 which structure is correctly named?    cc ch hhhha ethanoic acidoo h hc chh hhb etheneh hc chh hhc ethanolo h cchh hhhd propanec h      36 which properties of the different compounds in petroleum enable its separation into fractions?    1 boiling point  2 chain length 3 chemical reactivity  4 solubility in water    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      37 alkenes have the general formula c nh2n.    which of the following is an alkene?  a ch 2 b ch 4 c c 3h6 d c 6h6     ",
            "14": "14  \u00a9 ucles 2012 0620/11/o/n/12  38 bitumen is a substance obtained from the fractional distillation of petroleum.    which row describes its boiling point and the size of its molecules?     boiling point size of molecules  a high large  b high small  c low large  d low small     39 a hydrocarbon x is cracked to make y and hydrogen.    compound z is formed by the addition polymerisation of y.    to which homologous series do x, y and z belong?     alkane alkene  a x, y and z \u2013  b x and y z  c x and z y  d y and z x      40 which row is correct for ethanol?     burns made by  fermentation  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "15": "15  \u00a9 ucles 2012 0620/11/o/n/12  blank page   ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2012 0620/11/o/n/12   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w12_qp_12.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib12 11_0620_12/fp  \u00a9 ucles 2012  [turn over       *5992676139* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  october/november 2012       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2012 0620/12/o/n/12  1 what are the processes w, x, y and z in the following diagram?     w x  solid    liquid    gas   y z    w x y z  a condensing boiling freezing melting  b condensing freezing melting boiling  c melting boiling freezing condensing  d melting freezing condensing boiling    2 part of the instructions in an experiment reads as follows.    quickly add 50  cm3 of acid.    what is the best piece of apparatus to use?  a a burette  b a conical flask  c a measuring cylinder  d a pipette     3 a mixture of sulfur and iron filings needs to be separated. the solubilities of sulfur and iron filings  in water and carbon disulfide are shown in the table below.     solubility  in water solubility in  carbon disulfide sulfur \u0017 \u0013  iron filings \u0017 \u0017    what are possible methods of separating the sulfur and iron filings?     using  water using  carbon disulfide using  a magnet  a \u0013 \u0013 \u0017  b \u0017 \u0013 \u0013  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0017    ",
            "3": "3  \u00a9 ucles 2012 0620/12/o/n/12 [turn over  4 which row gives the number of electrons in the outer electron shell of fluorine and of neon?     f19 9 ne20 10  a 7 8  b 7 10  c 9 8  d 9 10     5 which statements comparing the properties of electrons, neutrons and protons are correct?     neutrons and protons are  both heavier than electrons only electrons and  neutrons are charged  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     6 the table shows the electronic structures of four atoms.    atom electronic structure  w 2,1  x 2,7  y 2,8,4  z 2,8,8    which two atoms combine to form an ionic compound?  a w and x b w and y c x and y d x and z    7 in the molecules ch 4, hcl and h 2o, which atoms use all of their outer shell electrons in bonding?  a c and c l b c and h c cl and h d h and o     ",
            "4": "4  \u00a9 ucles 2012 0620/12/o/n/12  8 a compound has the formula ch 3co 2h.    how should the relative molecular mass, mr, of this compound be calculated?  a 12 + 1 + 16  b 3(12 + 1) + 2(12 + 16) + 1  c (4 \u00d7 12) + (2 \u00d7 1) + 16  d (2 \u00d7 12) + (4 \u00d7 1) + (2 \u00d7 16)      9 the diagram shows an electrolysis experiment using metals x and y as electrodes.    aqueous solution xy+\u2013     one of the metals becomes coated with copper.    which metal becomes coated and which aqueous solution is used?     metal aqueous  solution  a x crc l 3  b x cuc l 2  c y crc l 3  d y cuc l 2     ",
            "5": "5  \u00a9 ucles 2012 0620/12/o/n/12 [turn over  10 the diagram shows the electrolysis of concentrated aqueous sodium chloride.    +\u2013positive electrodenegative electrode concentrated aqueous sodiumchloridecarbon rods     what is produced at each of the electrodes?     product at cathode product at anode  a hydrogen chlorine  b hydrogen oxygen  c sodium chlorine  d sodium oxygen      11 the diagrams show the difference in energies  of the reactants and products in two types of  reaction.    energydiagram 1 heat taken in products reactantsenergydiagram 2 heat given out reactants products     which diagram and which type of energy change apply to a fuel burning in air?     diagram type of energy change  a 1 endothermic  b 1 exothermic  c 2 endothermic  d 2 exothermic    ",
            "6": "6  \u00a9 ucles 2012 0620/12/o/n/12  12 which change is an oxidation?  a feo to fe 2o3  b fe2o3 to feo  c h2o2 to h 2o  d h2o to h 2      13 the diagram shows a match.        by striking the match, a chemical reaction takes place.    which statements about the chemical reaction are correct?     type of reaction reason  a endothermic because energy is used to strike the match  b endothermic because energy is given out as the match burns  c exothermic because energy is used to strike the match  d exothermic because energy is given out as the match burns      14 separate samples of anhydrous and hydrated copper( ii) sulfate are heated.    heatanhydrous copper( ii) sulfate heathydrated copper( ii) sulfate     which shows the correct colour changes?     anhydrous copper( ii) sulfate hydrated copper( ii) sulfate  a blue to white white to blue  b no change blue to white  c white to blue blue to white  d white to blue no change     ",
            "7": "7  \u00a9 ucles 2012 0620/12/o/n/12 [turn over  15 element x forms an acidic, covalent oxide.    which row shows how many electrons there could be in the outer shell of an atom of x?     1 2 6 7  a \u0013 \u0013 \u0017 \u0017  b \u0013 \u0017 \u0013 \u0017  c \u0017 \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017 \u0013     16 which change does not increase the speed of reaction between zinc and hydrochloric acid?  a adding a catalyst  b decreasing the particle size of the zinc  c decreasing the temperature  d using more concentrated acid     17 barium hydroxide is an alkali. it reacts with hydrochloric acid.    how does the ph of the hydrochloric acid change as an excess of aqueous barium hydroxide is  added?  a the ph decreases from 14 and becomes constant at 7.  b the ph decreases from 14 to about 1.  c the ph increases from 1 and becomes constant at 7.  d the ph increases from 1 to about 14.     18 which of these pairs of aqueous ions both  react with dilute sulfuric acid to give a visible result?  a ba 2+ and c l \u2212  b ba2+ and co 32\u2212  c nh 4+ and c l \u2212  d nh 4+ and co 32\u2212      19 a compound is a salt if it  a can neutralise an acid.  b contains more than one element.  c dissolves in water.  d is formed when an acid reacts with a base.   ",
            "8": "8  \u00a9 ucles 2012 0620/12/o/n/12  20 the table gives information about four elements.    which element is a transition metal?     colour  of element electrical  conductivity  of element colour  of oxide  a black high colourless  b colourless low white  c grey high red  d yellow low colourless     21 the diagram shows an outline of the periodic table.    x wy uv     which of the elements u, v, w, x and y would react together in the ratio of 1  : 1?  a u and x b u and y c v and y d w and x    22 the element rubidium, rb, is immediately below potassium in the periodic table.    it reacts with bromine to form the compound rubidium bromide.    which descriptions of this compound are correct?     type of bond formula colour  a covalent rbbr brown  b covalent rbbr 2 white  c ionic rbbr white  d ionic rbbr 2 brown    ",
            "9": "9  \u00a9 ucles 2012 0620/12/o/n/12 [turn over  23 brass is used in electrical equipment.    it contains two \u2026\u20261\u2026\u2026 elements. together they form \u2026\u20262\u2026\u2026 .    which words correctly complete gaps 1 and 2?     1 2  a metallic a covalent compound  b metallic an alloy  c non-metallic a covalent compound  d non-metallic an alloy      24 why are weather balloons filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen.  c helium is more dense than hydrogen.  d helium is unreactive.    25 some properties of aluminium are listed.    1 it has mechanical strength.  2 it conducts heat. 3 it is resistant to corrosion.  4 it has a low density.    which properties make aluminium useful for making the bodies of aircraft?  a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4     ",
            "10": "10  \u00a9 ucles 2012 0620/12/o/n/12  26 pieces of copper, iron, magnesium and zinc ar e added to separate test-tubes containing dilute  hydrochloric acid.    which test-tube contains iron and dilute hydrochloric acid?    a b c d      27 the basic oxygen process converts iron into steel.    in step 1, oxygen is blown into impure molten iron.    in step 2, oxides are removed by reaction with calcium oxide.    waste  gases oxygen molten iron  and  calcium oxide     which chemical reaction takes place in step 1 and which type of oxides are removed in step 2?     chemical reaction  in step 1 type of oxides removed  in step 2  a carbon is converted to carbon dioxide acidic  b carbon is converted to carbon dioxide basic  c iron is converted to iron( iii) oxide acidic  d iron is converted to iron( iii) oxide basic     ",
            "11": "11  \u00a9 ucles 2012 0620/12/o/n/12 [turn over  28 what is the correct order of abundance of the gases in the air?  a nitrogen \u2192 oxygen \u2192 argon \u2192 carbon dioxide  b nitrogen \u2192 oxygen \u2192 carbon dioxide \u2192 argon  c oxygen \u2192 nitrogen \u2192 argon \u2192 carbon dioxide  d oxygen \u2192 nitrogen \u2192 carbon dioxide \u2192 argon     29 which processes are used in the treatment of water?  a filtration and chlorination  b filtration and reduction  c neutralisation and chlorination  d neutralisation and reduction     30 a factory burns coal with a high sulfur content.    which pollutant is most  likely to lead to the death of trees?  a carbon dioxide  b carbon monoxide  c lead compounds  d sulfur dioxide     31 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change ",
            "12": "12  \u00a9 ucles 2012 0620/12/o/n/12  32 carbon dioxide is produced when dilute hydrochloric acid reacts with  a calcium sulfate.  b carbon.  c copper( ii) carbonate.  d limewater.     33 the diagram shows two substances, x and y, being heated together.    damp universal indicato r paper substances x and y heat    the universal indicator paper turns blue during the experiment.    what are substances x and y?  a ammonium nitrate and hydrochloric acid  b ammonium nitrate and sodium hydroxide  c sodium carbonate and hydrochloric acid  d sodium carbonate and sodium hydroxide     ",
            "13": "13  \u00a9 ucles 2012 0620/12/o/n/12 [turn over  34 a student is asked to draw a diagram showing the uses of limestone.    limestone making  cement making lime added, with hematite,  to a blast furnace 1 2  3      which numbered lines show a correct use of limestone?  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3     35 which properties of the different compounds in petroleum enable its separation into fractions?    1 boiling point  2 chain length  3 chemical reactivity  4 solubility in water    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      36 which structure is correctly named?    cc ch hhhha ethanoic acidoo h hc chh hhb etheneh hc chh hhc ethanolo h cchh hhhd propanec h       37 alkenes have the general formula c nh2n.    which of the following is an alkene?  a ch 2 b ch 4 c c 3h6 d c 6h6     ",
            "14": "14  \u00a9 ucles 2012 0620/12/o/n/12  38 a hydrocarbon x is cracked to make y and hydrogen.    compound z is formed by the addition polymerisation of y.    to which homologous series do x, y and z belong?     alkane alkene  a x, y and z \u2013  b x and y z  c x and z y  d y and z x      39 bitumen is a substance obtained from the fractional distillation of petroleum.    which row describes its boiling point and the size of its molecules?     boiling point size of molecules  a high large  b high small  c low large  d low small      40 which row is correct for ethanol?     burns made by  fermentation  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "15": "15  \u00a9 ucles 2012 0620/12/o/n/12  blank page     ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2012 0620/12/o/n/12   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w12_qp_13.pdf": {
            "1": "    this document consists of 14 printed pages and 2 blank pages.  ib12 11_0620_13/3rp  \u00a9 ucles 2012  [turn over       *1773725021* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  october/november 2012       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. you may use a calculator.  ",
            "2": "2  \u00a9 ucles 2012 0620/13/o/n/12  1 \u2018particles moving very slowly  from an area of high concentration to an area of low  concentration.\u2019    which process is being described above?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air      2 solid w melts at exactly 54  \u00b0c and boils at exactly 302  \u00b0c.    solid x, when dissolved in water and examined using paper chromatography, shows a blue  colour and a red colour.    which row is correct?     contains only  one substance contains more  than one substance  a w and x \u2013  b w x  c x w  d \u2013 w and x    3 part of the instructions in an experiment reads as follows.    quickly add 50  cm3 of acid.    what is the best piece of apparatus to use?  a a burette  b a conical flask  c a measuring cylinder  d a pipette     ",
            "3": "3  \u00a9 ucles 2012 0620/13/o/n/12 [turn over  4 the nucleon number of an isotope of rubidium is 85.    how many protons, neutrons and electrons are present in an atom of this isotope?     protons neutrons electrons  a 37 48 37  b 37 48 39  c 39 46 37  d 39 46 39     5 which row gives the number of electrons in the outer electron shell of fluorine and of neon?      f19 9 ne20 10  a 7 8  b 7 10  c 9 8  d 9 10     6 in the molecules ch 4, hcl and h 2o, which atoms use all of their outer shell electrons in bonding?  a c and c l b c and h c cl and h d h and o     7 the table shows the electronic structures of four atoms.    atom electronic structure  w 2,1  x 2,7  y 2,8,4  z 2,8,8    which two atoms combine to form an ionic compound?  a w and x b w and y c x and y d x and z    ",
            "4": "4  \u00a9 ucles 2012 0620/13/o/n/12  8 a compound has the formula ch 3co 2h.    how should the relative molecular mass, mr, of this compound be calculated?  a 12 + 1 + 16  b 3(12 + 1) + 2(12 + 16) + 1  c (4 \u00d7 12) + (2 \u00d7 1) + 16  d (2 \u00d7 12) + (4 \u00d7 1) + (2 \u00d7 16)      9 in separate experiments, electricity was passed through concentrated aqueous sodium chloride  and molten lead bromide.    what would happen in both  experiments?  a a halogen would be formed at the anode.  b a metal would be formed at the cathode.  c hydrogen would be formed at the anode.  d hydrogen would be formed at the cathode.     10 the diagram shows an electrolysis experiment using metals x and y as electrodes.    aqueous solution xy+\u2013     one of the metals becomes coated with copper.    which metal becomes coated and which aqueous solution is used?     metal aqueous  solution  a x crc l 3  b x cuc l 2  c y crc l 3  d y cuc l 2   ",
            "5": "5  \u00a9 ucles 2012 0620/13/o/n/12 [turn over  11 a diagram for the energy change during an exothermic reaction is shown.    energy reactants products     for which reactions would this be an appropriate diagram?    1 ch 4  +  2o 2  \u2192  co 2  +  2h 2o  2 2h 2  +  o 2  \u2192  2h 2o  3 c  +  o 2  \u2192  co 2    a none of them  b 1 and 2 only  c 2 and 3 only  d all of them      12 the diagram shows a match.        by striking the match, a chemical reaction takes place.    which statements about the chemical reaction are correct?     type of reaction reason  a endothermic because energy is used to strike the match  b endothermic because energy is given out as the match burns  c exothermic because energy is used to strike the match  d exothermic because energy is given out as the match burns     ",
            "6": "6  \u00a9 ucles 2012 0620/13/o/n/12  13 solid copper( ii) sulfate can exist in two different forms, anhydrous and hydrated.    one of these forms is blue and the other is white.    the change between these two forms is reversible.    blue form  white form    which is the blue form and how is the change from the blue form to the white form brought  about?     blue form change to  white form  a anhydrous add water  b anhydrous heat  c hydrated add water  d hydrated heat      14 which statement describes what happens in the reaction shown?    2mg  +  co 2  \u2192  2mgo  +  c    a carbon and magnesium are both oxidised.  b carbon is oxidised and magnesium oxide is reduced.  c magnesium is oxidised and carbon dioxide is reduced.  d magnesium oxide and carbon dioxide are both reduced.     15 which change does not increase the speed of reaction between zinc and hydrochloric acid?  a adding a catalyst  b decreasing the particle size of the zinc  c decreasing the temperature  d using more concentrated acid    ",
            "7": "7  \u00a9 ucles 2012 0620/13/o/n/12 [turn over  16 salts x and y are separately dissolved in water.    samples of the solutions obtained are separately tested with dilute hydrochloric acid and with  aqueous sodium hydroxide.    in two of the tests, a gaseous product is formed. no precipitate is formed in any of the tests.    what are salts x and y?     x y  a agno 3 baso 4  b baso 4 na 2co 3  c na2co 3 nh 4cl  d nh 4cl agno 3     17 some reactions involving sodium are shown.    which reaction does not involve the formation of a base?    sodiumsodium oxide sodium chloridesodium hydroxidea b cd       18 barium hydroxide is an alkali. it reacts with hydrochloric acid.    how does the ph of the hydrochloric acid change as an excess of aqueous barium hydroxide is  added?  a the ph decreases from 14 and becomes constant at 7.  b the ph decreases from 14 to about 1.  c the ph increases from 1 and becomes constant at 7.  d the ph increases from 1 to about 14.     ",
            "8": "8  \u00a9 ucles 2012 0620/13/o/n/12  19 a compound is a salt if it  a can neutralise an acid.  b contains more than one element.  c dissolves in water.  d is formed when an acid reacts with a base.      20 the diagram shows an outline of the periodic table.    wx y z     which ionic compound could be formed?  a w+y\u2013 b w+z\u2013 c x+y\u2013 d x+z\u2013      21 element x  is in group vii of the periodic table.    it reacts with aqueous potassium bromide as shown.    x2  +  2kbr  \u2192  2kx  +  br 2    which statements about x  are correct?     relative atomic mass reactivity  a greater than that of bromine less reactive than bromine  b greater than that of bromine more reactive than bromine  c less than that of bromine less reactive than bromine  d less than that of bromine more reactive than bromine     ",
            "9": "9  \u00a9 ucles 2012 0620/13/o/n/12 [turn over  22 the table gives information about four elements.    which element is a transition metal?     colour  of element electrical  conductivity  of element colour  of oxide  a black high colourless  b colourless low white  c grey high red  d yellow low colourless     23 why are weather balloons filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen.  c helium is more dense than hydrogen.  d helium is unreactive.    24 the three statements below about aluminium are all correct.    1 aluminium has an oxide ore.  2 aluminium is extracted from its ore by electrolysis.  3 aluminium is used to make cooking utensils.    in which of these statements can \u2018 aluminium \u2019 be replaced by \u2018 iron\u2019 and still be correct?     1 2 3  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0013     ",
            "10": "10  \u00a9 ucles 2012 0620/13/o/n/12  25 statement 1: an aluminium alloy containing a small amount of copper is stronger than pure  aluminium.    statement 2: alloys are made by mixing molten metals together and allowing them to cool.    which of the following is true?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is not correct.  d statement 2 is correct but statement 1 is not correct.      26 iron is extracted from its ore in a blast furnace.    hematite, coke, limestone and hot air are added to the furnace.    which explanation is not correct?  a coke burns and produces a high temperature.  b hematite is the ore containing the iron as iron oxide.  c hot air provides the oxygen for the burning.  d limestone reduces the iron oxide to iron.      27 how does the reactivity of potassium compare with that of sodium and how does the reactivity of  calcium compare with that of magnesium?     reactivity of  potassium and sodium reactivity of  calcium and magnesium  a k greater than na ca greater than mg  b k greater than na mg greater than ca  c na greater than k ca greater than mg  d na greater than k mg greater than ca     28 untreated water can spread diseases such as cholera.    what can be added to drinking water to reduce the spread of such diseases?  a carbon monoxide  b chlorine  c nitrogen monoxide  d sulfur     ",
            "11": "11  \u00a9 ucles 2012 0620/13/o/n/12 [turn over  29 statement 1: the burning of fossil fuels containing sulfur is a cause of \u2018acid rain\u2019.    statement 2: acid rain contains sulfur dioxide which is formed when sulfur compounds burn in the  air.    which of the following is true?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct, but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.      30 argon is a noble gas used to fill light bulbs.    what is the approximate percentage of argon in air?  a 1  % b 20  % c 79  % d 99  %    31 the experiment shown was set up to investigate the rusting of iron.    wate riron nails     rusting occurs in this experiment because of the presence of  a hydrogen and oxygen.  b nitrogen and oxygen.  c nitrogen and water.  d oxygen and water.      32 what are x and y in the reaction shown?    ammonium chloride  +  solution x  \u2192  alkaline gas y     x y  a hydrochloric acid ammonia  b hydrochloric acid chlorine  c sodium hydroxide ammonia  d sodium hydroxide chlorine ",
            "12": "12  \u00a9 ucles 2012 0620/13/o/n/12  33 which process does not produce carbon dioxide?  a combustion of petrol  b reaction between an acid and a metal hydroxide  c reaction between an acid and a carbonate  d respiration      34 two industrial processes that involve heating are    \u2022 extracting iron from its ore using a blast furnace,  \u2022 making lime.    in which of these processes is calcium carbonate used?     extracting iron making lime  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     35 which structure shows a carboxylic acid?    a h ch hhh c hd ch hhh cb h ch hhh c o hc h ch ho c o h      36 which method is used to obtain petrol from petroleum?  a crystallisation  b diffusion  c filtration  d fractional distillation    ",
            "13": "13   ucles 2012 0620/13/o/n/12  37 which group of compounds is part of a homologous series?  a ch 4, c2h4, c3h8  b c 3h6, c3h8, c3h7oh  c ch 3oh, c 2h5oh, c 3h7oh  d ch 3co 2h, ch 3ch 2oh, hco 2h      38 bitumen is a substance obtained from the fractional distillation of petroleum.    which row describes its boiling point and the size of its molecules?     boiling point size of molecules  a high large  b high small  c low large  d low small      39 a hydrocarbon a is cracked to make b and hydrogen.    compound c is formed by the addition polymerisation of b.    to which homologous series do a, b and c belong?     alkene alkane  a a b and c  b b a and c  c c a and b  d \u2013 a and c     40 which statement about ethanol is not correct?  a it can be used as a fuel.  b it can be used as a solvent.  c it is formed by reaction between steam and ethane.  d its functional group is \u2013oh.    ",
            "14": "14  \u00a9 ucles 2012 0620/13/o/n/12  blank page ",
            "15": "15   ucles 2012 0620/13/o/n/12  blank page   ",
            "16": "16      permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2012 0620/13/o/n/12   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w12_qp_21.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 october/november 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib12 11_0620_21/3rp\u00a9 ucles 2012 *3776834834* for examiner\u2019s use 1 234567 total",
            "2": "2 0620/21/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  the diagram shows the structures of \ufb01 ve compounds, a, b, c, d and e, containing carbon. cch hhh ch hc o h hhh cocab c o cl cl clcl cde hh hh  (a)  answer these questions using the letters a, b, c, d or e.   each compound can be used once, more than once or not at all.   which one of these compounds  (i)  is an unsaturated hydrocarbon,  ...  [1]  (ii)  is a product of the complete combustion of a hydrocarbon,    [1]  (iii)  belongs to the alcohol homologous series,  .  [1]  (iv)  is an alkane,    [1]  (v)  is a product of respiration,  ...  [1]  (vi)  is a product of fermentation?  ...  [1]  (b)  write the molecular formula of compound c.  .  [1]  (c)  compound b is inert to most chemical reagents.   it is made by reacting chlorine with carbon disul \ufb01 de in the presence of an aluminium  chloride catalyst.   what do you understand by the following terms?  compound   .   ... ..  [1]  inert  .  [1]  catalyst   ...  [1] [total: 10]",
            "3": "3 0620/21/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  hydrogen chloride, hc l, is an acidic gas.  (a)  draw a dot and cross diagram of a molecule of hydrogen chloride.   show only the outer electrons. [2]  (b)  hydrogen chloride dissolves in water to form a solution of hydrochloric acid.   a student titrated aqueous ammonia with hydrochloric acid using the apparatus shown  below. bhydrochloric acid aqueous ammoniaa  (i)  state the name of the pieces of apparatus labelled a and b.  a is a  ...  [1]  b is a  ...  [1]  (ii)  describe how the ph value of the solution in b changes as hydrochloric acid is  added until the acid is in excess.   . ...   . ...   . .  [3]",
            "4": "4 0620/21/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (iii)  complete the word and symbol equations for this reaction. ammonia  +  hydrochloric acid  \u2192  ...  ... + hc l \u2192 nh4cl [2]  (c)  aqueous ammonia is used to test for copper( ii) ions.   describe what happens when you add aqueous ammonia to a solution of copper( ii)  sulfate until the aqueous ammonia is in excess.   ...    ...    ...    ... ..  [4] [total: 13]",
            "5": "5 0620/21/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use3  the reactivity of different metal oxides was compared by heating them with metals in a  crucible. heatmixture of metaloxide and metal   the results are shown in the table below. mixture observations iron oxide + zinc reacts lead oxide + iron reacts magnesium oxide + zinc no reaction  (a) (i)   use the results in the table to suggest the order of reactivity of the metals iron, lead,  magnesium and zinc. most reactive least reactive [2]  (ii)  predict whether iron will react with zinc oxide.   explain your answer.   . ...   . .  [1]  (b)  which two of the following statements about metals are correct?   tick two boxes.  metals conduct electricity and heat. all group iv elements show metallic properties. magnesium is extracted by heating its oxide with carbon. all metals have high densities. iron is a transition element. [2]",
            "6": "6 0620/21/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (c)  sand and salt (sodium chloride) are both solids.  (i)  describe the arrangement and movement of the particles in a solid.  arrangement  .. movement    [2]  (ii)  describe how you could separate the sand from a mixture of sand and salt.  give full details of how this is carried out.   . ...   . ...   . ...   . .  [3]  (d)  the diagram below shows the apparatus used to separate ethanol and water from a  mixture of ethanol and water. heatethanol and waterfractionating columnwater out water in   complete the following sentences about this separation using words from the list below.  condenser crystallisation distillation \ufb02 ask heavy  higher lower solid volatile vapour  fractional ... is used to separate a mixture of water and ethanol. the  temperature at the top of the fractionating column is ... than the temperature at the bottom. the more ... liquid evaporates and moves further up the column. it eventually reaches the ... where the ... changes to a liquid. [5] [total: 15]",
            "7": "7 0620/21/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use4  lithium has two naturally-occurring isotopes, li6 3 and li7 3.  (a)  what do you understand by the term isotope ?   ...    ... ..  [1]  (b)  draw a labelled  diagram to show the atomic structure of an atom of li7 3.   show the particles in the nucleus as well as the electrons. [5]  (c)  lithium reacts with oxygen to form lithium oxide, li2o.   complete the equation for this reaction. ..li   +   .   \u2192   ..li2o [3]",
            "8": "8 0620/21/o/n/12 \u00a9 ucles 2012for examiner\u2019s use(d)  aqueous lithium chloride is electrolysed using the apparatus shown below. + \u2013  (i)  on the diagram above, label:  \u25cf the electrolyte  \u25cf the anode. [2]  (ii)  what do you understand by the term aqueous ?   . .  [1]  (iii)  explain why aqueous lithium chloride is able to conduct electricity.   . .  [1] [total: 13]",
            "9": "9 0620/21/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use5 (a)   match the fuel on the left with the information on the right.   the \ufb01 rst one has been done for you. uranium-236a fuel with a relative molecular mass of 2 hydrogenthe main constituent of natural gas methane a nuclear \u2018fuel\u2019 fuel oil fuel for aircraft kerosene fuel for ships [4]  (b)  two students investigated some fuels to \ufb01 nd which gave off the most energy.   they tested four liquid fuels using the apparatus shown below. thermometer spirit burnercopper can liquid fuel100  g of wate r  (i)  in each experiment, the amount of fuel burnt was the same.   suggest one other factor that should be kept the same in each experiment.   . .  [1]  (ii)  the students used the thermometer to stir the water.   suggest why it is important to keep the water stirred.   . .  [1]",
            "10": "10 0620/21/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (iii)  the results are shown in the table below. fuelinitial temperature  of the water  / \u00b0c\ufb01 nal temperature  of the water  / \u00b0c ethanol 24 40 propanol 24 42 paraf \ufb01 n2 2 3 3 petroleum spirit 20 40   which fuel transfers the most energy to the water?   explain your answer.   . ...   . .  [2]  (c)  air is needed for fuels to burn.   the pie chart below shows the composition of the air. mainly argonab  state the name of  gas a,  ... .  gas b.  .. ...  [2]  (d) argon is a noble gas.  (i)  state one use for argon.   . .  [1]  (ii)  to which period in the periodic table does argon belong?   . .  [1]  (iii)  describe the chemical properties of argon.   . .  [1] [total: 13]",
            "11": "11 0620/21/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use6  a student placed a crystal of silver nitrate and a crystal of potassium iodide in a dish of water.  after an hour she observed that  \u25cf the crystals had disappeared,  \u25cf a yellow precipitate had appeared near the middle of the dish. at the start after an hourcrystal of silver nitratecrystal of potassiumiodidedish of water yellowprecipitate  (a)  use your knowledge of the kinetic particle theory and reactions between ions to explain  these observations.   ...    ...    ...    ...    ... ..  [4]  (b)  potassium iodide reacts with aqueous chlorine.   complete the equation for this reaction. 2ki  +    \u2192  ..kc l  +  i2 [2] [total: 6]",
            "12": "12 0620/21/o/n/12 \u00a9 ucles 2012for examiner\u2019s use7  the diagram shows one molecule of sulfur. s s sss s ss  (a)  how many atoms are there in three  molecules of sulfur?   ... ..  [1]  (b)  calculate the relative molecular mass of sulfur. [1]  (c)  explain how acid rain is formed when fossil fuels containing sulfur are burnt.   in your answer, include  \u25cf the name of a fossil fuel which contains sulfur,  \u25cf the gas formed when sulfur burns,  \u25cf the reactions which lead to the formation of acid rain.   ...    ...    ...    ...    ... ..  [4]  (d)  potassium sulfate can be used as a fertiliser.   the potassium in this fertiliser is an important element for plant growth.   name two other elements , important for plant growth, which are present in most  fertilisers.  .  and  .. ... [2]  (e)  describe a test for sulfate ions.  test     result  .. .  [2] [total: 10]",
            "13": "13 0620/21/o/n/12blank page \u00a9 ucles 2012",
            "14": "14 0620/21/o/n/12blank page \u00a9 ucles 2012",
            "15": "15 0620/21/o/n/12blank page \u00a9 ucles 2012",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/21/o/n/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w12_qp_22.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 october/november 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib12 11_0620_22/2rp\u00a9 ucles 2012 *2998687209* for examiner\u2019s use 1 234567 total",
            "2": "2 0620/22/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  the diagram shows the structures of \ufb01 ve elements, a, b, c, d and e. c cc cc cc cc c c cccc c ccc ccc c ccccc cccucucucu cucucucu cucucucuab c d e cl cl clclcl clp p ppp p pp p p pphehe he he hehe  (a)  answer these questions using the letters a, b, c, d or e.  each element can be used once, more than once or not at all.   which one of these elements  (i)  is in group v of the periodic table,  .  [1]  (ii)  is used to \ufb01 ll weather balloons,    [1]  (iii)  is a diatomic gas at room temperature,  ...  [1]  (iv)  conducts electricity, ..  [1]  (v)  is a transition element?    [1]  (b)  which two of the elements a, b, c, d or e are simple molecules?  .  and  .. ... [2]  (c)  which two of the words or phrases in the list below describe the structure of element b?  covalent giant ionic  metallic simple atomic simple molecular .  and  .. ... [2]  (d)  what do you understand by the term element  ?   ... ..  [1] [total: 10]",
            "3": "3 0620/22/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  ammonia, nh3, is an alkaline gas.  (a)  describe a test for ammonia.  test     result  .. .  [2]  (b)  what is the ph of an aqueous solution of ammonia?   put a ring around the correct answer.  ph  1 ph  3 ph  5 ph  7 ph  9 [1]  (c)  ammonia reacts with hydrochloric acid.  (i)  complete the symbol equation for this reaction. nh3  +  hc l  \u2192  .. [1]  (ii)  hydrochloric acid can be made by dissolving hydrogen chloride, hc l, in water.   draw a diagram to show the arrangement of electrons in hydrogen chloride.   show only the outer electrons.   show a hydrogen electron as \u25cf   show a chlorine electron as x [2]",
            "4": "4 0620/22/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (d)   aqueous ammonia reacts with sulfuric acid to form a solution of ammonium sulfate. 2nh3(aq)  +  h2so4 (aq)  \u2192  (nh4)2so4 (aq)  (i)  ammonium sulfate is a colourless salt. describe how you could use a titration method  to make a colourless solution of ammonium sulfate.   . ...   . ...   . ...   . ...   . ...   . .  [4]  (ii)  how can crystals of ammonium sulfate be obtained from a solution of ammonium  sulfate?   . ...   . .  [1] [total: 11]",
            "5": "5 0620/22/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use3  the table below shows the properties of some halogens. halogen colourstate at room temperaturemelting point / \u00b0c \ufb02 uorine yellow \u2013220 chlorine light green gas bromine brownish-red liquid \u20137 iodine grey-black solid +114  (a) (i)   what is the trend in the colour of the halogens down the group?   . .  [1]  (ii)  predict the state of \ufb02 uorine at room temperature.   . .  [1]  (iii)  predict the melting point of chlorine.   . .  [1]  (b)  the reactivity of three different halogens was compared by reacting them with solutions  of sodium halides.   the results are shown in the table below. reaction mixture observations astatine + sodium iodide colour of reaction mixture remains unchanged bromine + sodium iodide mixture turns dark brown chlorine + sodium bromide mixture turns brownish-red  (i)  use the results in the table to suggest the order of reactivity of astatine, bromine,  chlorine and iodine. most reactive least reactive [2]  (ii)  predict whether bromine will react with sodium chloride solution.   explain your answer.   . ...   . .  [1]",
            "6": "6 0620/22/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (c)  chlorine reacts with excess cold dilute sodium hydroxide. the products of the reaction  are sodium chloride, sodium chlorate( i) and water.   the formula of sodium chlorate( i) is nac l o.   complete the equation for this reaction. cl 2  +  ..naoh  \u2192  nac l  +  nac l o  +  .. [2]  (d) (i)   explain why chlorine is used in water puri \ufb01 cation.   . .  [1]  (ii)  impure water contains particles of minerals and remains of dead plants and animals.   one stage in water puri \ufb01 cation is the removal of these particles by \ufb01 ltration.   the diagram below shows a water \ufb01 lter. water insmall particles of sand  explain how this water \ufb01 lter works.   . ...   . ...   . .  [2] [total: 11]",
            "7": "7 0620/22/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use4  the process of distillation is used in an oil re \ufb01 nery to separate petroleum into different  fractions.  (a)  what do you understand by the term petroleum fraction  ?   ...    ... ..  [2]  (b)  some petroleum fractions are more useful than others. there is a greater demand for  these fractions.   the diagram shows the demand from customers and the ability of an oil re \ufb01 nery to  supply these fractions by fractional distillation alone. 50 40302010 0percentage refinery gas gasoline kerosene diesel fuel oil lubricating oil and bitumensupply from refinery demand  (i)  state the name of two fractions for which demand is greater than supply.   . .  [2]  (ii)  state one use for each of the following fractions.  re \ufb01 nery gas    bitumen    [2]  (c)  more gasoline can be made by cracking long-chain hydrocarbons.   state the conditions needed for cracking.   ...    ... ..  [2]",
            "8": "8 0620/22/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (d)  dodecane, c12h26, can be cracked to form smaller hydrocarbons.  (i)  what do you understand by the term hydrocarbon  ?   . .  [1]  (ii)  complete the equation for the cracking of dodecane. c12h26  \u2192  c8h18  +  . [1]  (e)  ethene, c2h4, can be formed by cracking.  (i)  draw the full structure of ethene showing all atoms and bonds. [1]  (ii)  poly(ethene) can be made from ethene.   complete the following sentences using words from the list below.  addition atoms condensation dimers  monomers polymers subtraction  the small ethene molecules which join together to form poly(ethene) are called  ethene  . the process of joining the ethene molecules together is an example of an  reaction. the long-chain molecules which are formed are called  . [3] [total: 14]",
            "9": "9 0620/22/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use5  aluminium is in group iii of the periodic table. iron is a transition element.  (a)  both aluminium and iron have high melting points and boiling points.   state two differences in the physical properties of aluminium and iron.   ...    ... ..  [2]  (b)  state one use of aluminium.   ... ..  [1]  (c)  sodium hydroxide is used to test for aluminium ions.   describe what happens when you add a solution of sodium hydroxide to a solution of  aluminium ions until the sodium hydroxide is in excess.   ...    ...    ... ..  [3] [total: 6]",
            "10": "10 0620/22/o/n/12 \u00a9 ucles 2012for examiner\u2019s use6  the diagram below shows a kiln used for manufacturing lime. air blown inwaste gases mixture of calcium carbonateand coke lime removed   the reaction taking place in the kiln is calcium carbonate  \u2192  calcium oxide  +  carbon dioxide  (lime)  (a) (i)   state the name of a rock which is largely calcium carbonate.   . .  [1]  (ii)  explain why, at the end of the reaction, there is only lime left in the lime kiln.   . .  [1]  (b) (i)   coke is mainly carbon.   combustion of coke provides the heat for the reaction in the lime kiln.   write a symbol equation for the complete combustion of carbon in oxygen.   . .  [2]  (ii)  complete these sentences using words from the list below.  air dioxide harmless hydrogenated  limited monoxide poisonous water  when carbon burns in a .. supply of .., carbon  .. is formed. this is a colourless gas which has no smell and is .. . [4]",
            "11": "11 0620/22/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  calcium carbonate reacts with hydrochloric acid to form carbon dioxide.   complete the word equation for this reaction. calcium carbonatecarbon dioxide++ + \u2192hydrochloric acid. .. [2]  (d)  the speed of reaction of calcium carbonate with hydrochloric acid can be found using the  apparatus shown below. cotton wool top pan balancehydrochloric acidsmall pieces of calcium carbonate  (i)  suggest how this apparatus can be used to \ufb01 nd the speed of this reaction.   . ...   . ...   . .  [2]  (ii)  state how the speed of this reaction changes when  the concentration of acid is increased,  .. larger pieces of calcium carbonate are used,   the temperature is increased.  ..  [3] [total: 15]",
            "12": "12 0620/22/o/n/12 \u00a9 ucles 2012for examiner\u2019s use7  the structures of iodine and potassium iodide are shown below. i\u2013k+ i\u2013k+i\u2013 i\u2013k+ k+i\u2013k+ i\u2013k+i\u2013 i\u2013k+i ii ii ii i i ii ii ii ii ii ii ii i k+ iodine potassium iodide  (a)  iodine is a solid at room temperature. its melting point is +114  \u00b0c.  (i)  describe what happens to the arrangement and movement of iodine molecules  when iodine is gradually heated from 20  \u00b0c to 120  \u00b0c.   . ...   . ...   . ...   . ...   . .  [4]  (ii)  calculate the relative molecular mass of iodine.   . .  [1]  (b) (i)   what type of bonding is present in potassium iodide?   . .  [1]  (ii)  write the simplest formula for potassium iodide.   . .  [1]",
            "13": "13 0620/22/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  complete the table below to show the solubility in water and electrical conductivity of  solid iodine and solid potassium iodide. substance solubility in waterelectrical conductivity of solid iodine potassium iodide [4]  (d)  predict the product formed at each electrode when molten potassium iodide is  electrolysed.  at the positive electrode    at the negative electrode    [2] [total: 13]",
            "14": "14 0620/22/o/n/12blank page \u00a9 ucles 2012",
            "15": "15 0620/22/o/n/12blank page \u00a9 ucles 2012",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/22/o/n/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w12_qp_23.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/23   paper 2 october/november 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib12 11_0620_23/3rp\u00a9 ucles 2012 *3659885698* for examiner\u2019s use 1 2345678 total",
            "2": "2 0620/23/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  part of the periodic table of elements is shown below. hh e nof n e ps c lar br i  (a)  answer the following questions using only the elements shown in the table above.   write the symbol for an element which  (i)  is used to \ufb01 ll light bulbs,  ...  [1]  (ii)  is in group vi and period 3 of the periodic table,  ...  [1]  (iii)  is a greyish-black solid,  ...  [1]  (iv)  forms about 79  % of the air,  .  [1]  (v)  consists of single atoms with a full outer shell of electrons,    [1]  (vi)  is liberated at the cathode when concentrated hydrochloric acid is electrolysed. .  [1]  (b)  hydrogen reacts with chlorine to form hydrogen chloride.  (i)  complete the equation for this reaction. h2  +  .  \u2192  ..hc l [2]  (ii)  draw the electronic structure of a chlorine molecule.   show only the outer shell electrons. [2] [total: 10]",
            "3": "3 0620/23/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  vinegar contains ethanoic acid. the formula of ethanoic acid is shown below. c hh hco oh  (a) (i)   on the formula above, put a ring around the carboxylic acid functional group. [1]  (ii)  write the simplest formula for a molecule of ethanoic acid. [1]  (b)  ethanoic acid reacts with sodium hydroxide to form the salt sodium ethanoate. ethanoic acid  +  sodium hydroxide  \u2192  sodium ethanoate  +  water  what type of chemical reaction is this?  ... ..  [1]  (c)  sodium ethanoate is soluble in water.   what do you understand by the term soluble  ?   ... ..  [1]  (d)  which one of the following is the most likely ph value of ethanoic acid?   put a ring around the correct answer.  ph 3 ph 7 ph 9 ph 13 [1]  (e)  all acids react with carbonates.   complete the general equation for this reaction. acid  + carbonate  \u2192  salt  +    +     [2]",
            "4": "4 0620/23/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (f)  the structure of sodium carbonate is shown below. co32\u2013 na+na+ co32\u2013 na+na+co32\u2013 na+na+ co32\u2013 na+na+  write the simplest formula for sodium carbonate.   ... ..  [1] [total: 8]",
            "5": "5 0620/23/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use3  a student used the apparatus shown below to separate a mixture of coloured dyes. the  solvent is not shown. filter paperbeaker mixture of dyes  (a)  on the diagram above, draw and label the position of the solvent at the start of the  experiment. [1]  (b)  the student let the solvent move up the \ufb01 lter paper to separate the dyes.  (i)  state the name of this method of separation.   . .  [1]  (ii)  the student found that four different dyes had been separated by this method.  on the diagram below draw  \u25cf the position of four separated dyes (show as spots)  \u25cf the solvent front (show as a line). original position of dye mixture [3]  (c)  part of the structure of a dye called indigo is shown below. cc nno och hc   is this a saturated or unsaturated compound?   give a reason for your answer.   ... ..  [1] [total: 6]",
            "6": "6 0620/23/o/n/12 \u00a9 ucles 2012for examiner\u2019s use4  hydrogen can be manufactured by heating methane with steam. ch4  +  h2o co  +  3h2400  \u00b0c + catalyst  (a) (i)   draw the structure of methane showing all atoms and bonds. [1]  (ii)  methane is a greenhouse gas.   what do you understand by the term greenhouse gas ?   . .  [1]  (iii)  state one source of the methane in the atmosphere.   . .  [1]  (iv)  when 16  g of methane reacts completely with an excess of steam, 6  g of hydrogen  are produced.   calculate the mass of methane required to produce 300  g of hydrogen.  answer = ... [1]  (b)  more hydrogen can be formed by reacting the carbon monoxide with more steam at 500  \u00b0c. co  +  h2o    co2  +  h2   this reaction is reversible.  (i)  how do you know from this equation that the reaction is reversible?   . .  [1]  (ii)  what do you understand by the term reversible reaction ?   . .  [1]",
            "7": "7 0620/23/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (iii)  carbon monoxide is a common atmospheric pollutant.   state a source of the carbon monoxide in the atmosphere other than from the manufacture of hydrogen.   . .  [1]  (iv)  carbon dioxide is a product of the reaction between carbon monoxide and steam.   is carbon dioxide an acidic or a basic oxide?   give a reason for your answer.   . .  [1] [total: 8]",
            "8": "8 0620/23/o/n/12 \u00a9 ucles 2012for examiner\u2019s use5  ethanol can be made by  \u25cf an addition reaction with ethene or  \u25cf by fermentation.  (a) (i)   state the name of the substance that needs to be added to ethene to make ethanol.   . .  [1]  (ii)  what conditions are needed to make ethanol from ethene?   . ...   . .  [2]  (b) (i)   complete the word equation for fermentation in the presence of yeast. ..  \u2192  ethanol  +  ..  .. [2]  (ii)  the yeast contains enzymes.   what do you understand by the term enzyme ?   . ...   . .  [2]  (c)  the speed of ethanol formation during fermentation depends on the temperature.  (i)  use the information in the table below to describe how the speed of this reaction  changes with temperature. temperature / \u00b0cspeed of reaction / g ethanol formed  per hr 10 1 20 330 740 1150 660 270 0   . ...   . ...   . .  [3]",
            "9": "9 0620/23/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  state two factors which should be kept constant during this experiment.   . ...   . .  [2]  (d)  ethanol belongs to the alcohol homologous series.   the boiling points of some alcohols are given in the table below. alcoholnumber of carbon atoms in the alcoholboiling point / \u00b0c methanol 1 65 ethanol 2 79 propanol 3 98 butanol 4 117  (i)  on the grid below, plot a graph of boiling point against the number of carbon atoms.  join the points with a smooth line. 160 140120100 806040 012345 number of carbon atoms in the alcoholboiling point  / \u00b0c [3]  (ii)  use your graph to estimate the boiling point of the alcohol having \ufb01 ve carbon atoms.  boiling point =  \u00b0c [1] [total: 16]",
            "10": "10 0620/23/o/n/12 \u00a9 ucles 2012for examiner\u2019s use6  lead and lead compounds are common pollutants of the air.  (a) (i)  state one source of lead in the air.   . .  [1]  (ii)  state one effect of lead on human health.   . .  [1]  (b)  lead( ii) oxide can be reduced by heating with carbon. heat pbo  +  c   \u2192   pb  +  co  (i)  write a word equation for this reaction.   . .  [1]  (ii)  explain how you know that lead( ii) oxide is reduced in this reaction.   . ...   . .  [1]  (iii)  explain why this reaction is described as endothermic.   . .  [1]  (c)  lead nitrate solution reacts with sodium iodide solution. lead nitrate  +  sodium iodide  \u2192  lead iodide  + sodium nitrate   lead iodide is insoluble in water but the reactants and sodium nitrate are soluble.   draw a labelled diagram to explain how you can separate lead iodide from the rest of the  reaction mixture. [2]  (d)  complete the table below to show the number of protons, electrons and neutrons in the  isotope of lead          . number of protons number of electronsnumber of neutrons [2] [total: 9]204pb82",
            "11": "11 0620/23/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use7  the diagram below shows the apparatus used to electroplate a spoon with silver. rod of pure silveriron spoon aqueous silver nitrate+\u2013battery  (a)  which is the anode?   put a ring around the correct answer in the list below. aqueous silver nitrate battery iron spoon rod of pure silver [1]  (b)  describe what happens to the silver rod and the iron spoon during electroplating.  silver rod  .. .  iron spoon  .. .  [2]  (c)  why are metal objects electroplated?   ... ..  [1]  (d)  during the electroplating, silver atoms are converted to silver ions.   which one of the following statements about this reaction is correct?   tick one box.  silver atoms gain electrons. silver atoms lose neutrons. silver atoms lose electrons. silver atoms gain protons. [1]",
            "12": "12 0620/23/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (e)  a student is given a slightly alkaline solution which contains chloride ions.   describe how the student could use aqueous silver nitrate to show that chloride ions are  present in the solution.   ...    ...    ... ..  [3]  (f)  silver is a shiny metallic solid with a high melting point and boiling point.   describe two other  physical properties of silver.  1  ... .  2  ... ...  [2] [total: 10]",
            "13": "13 0620/23/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use8  the diagram shows a type of blast furnace built about 230 years ago. it was used to extract  iron from iron ore. ba cde  (a)  which letter on the diagram shows  (i)  where the solid raw materials are put into the furnace,  ...  [1]  (ii)  where air is blown into the furnace,  .  [1]  (iii)  where iron is removed from the furnace?    [1]  (b)  describe the main reactions occurring in a blast furnace for extracting iron from iron ore.   in your answer, include  \u25cf the names of the raw materials used  \u25cf the main chemical reactions which occur  \u25cf relevant word equations.   ...    ...    ...    ...    ...    ...    ... ..  [5]",
            "14": "14 0620/23/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (c)  iron reacts with hydrochloric acid.  (i)  complete the word equation for this reaction. iron  +  hydrochloric acid  \u2192  ..  +  ..  .. [2]  (ii)  iron( ii) ions are formed in this reaction.   describe a test for iron( ii) ions.  test   .  result    [2]  (d)  steel is an alloy of iron.   which one of the following statements about steel is correct?   tick one box.  steel is a mixture of iron with sulfur atoms. stainless steel is commonly used to make car bodies. the physical properties of steel are exactly the same  as those of iron.   steel is made by blowing oxygen through the molten  iron obtained from the blast furnace. [1] [total: 13]",
            "15": "15 0620/23/o/n/12blank page \u00a9 ucles 2012",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/23/o/n/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w12_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) october/november 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib12 11_0620_31/2rp\u00a9 ucles 2012 *1129003385* for examiner\u2019s use 1 234 5 67 total",
            "2": "2 0620/31/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  a list of techniques used to separate mixtures is given below. \ufb01 ltration diffusion fractional distillation simple distillation crystallisation chromatography   from this list, choose the most suitable technique to separate the following mixtures.   a technique may be used once, more than once or not at all.  (a)  butane from a mixture of propane and butane  ...  [1]  (b)  oxygen from liquid air  .  [1]  (c)  water from aqueous magnesium sulfate  .  [1]  (d)  potassium chloride from aqueous potassium chloride    [1]  (e)  silver chloride from a mixture of silver chloride and water  ..  [1]  (f)  glucose from a mixture of glucose and maltose  .  [1] [total: 6]",
            "3": "3 0620/31/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  three of the halogens in group vii are listed below. chlorine bromine iodine  (a) (i)   how does their colour change down the group?   . .  [1]  (ii)  how do their melting points and boiling points change down the group?   . .  [1]  (iii)  predict the colour and physical state (solid, liquid or gas) of astatine, at.  colour  .. ...  physical state  ...  [2]  (b)  a radioactive isotope of iodine, i53131, is used to treat cancer.   (i)  de\ufb01 ne the term isotope .   . ...   . .  [2]  (ii)  how many protons, electrons and neutrons are there in one atom of i53131?  number of protons  ..  number of electrons   number of neutrons    [2]  (iii)  when this isotope,  i53131, emits radiation, a different element with a proton number of  54 is formed.   what is the name of this element?   . .  [1]  (c)  fluorine, the most reactive halogen, forms compounds with the other halogens. it forms  two compounds with bromine.   deduce their formulae from the following information.  compound 1   the mass of one mole of this compound is 137  g.  its formula is . [1]  compound 2   0.02 moles of this compound contain 0.02 moles of bromine atoms and 0.1 moles of \ufb02 uorine atoms.  its formula is . [1] [total: 11]",
            "4": "4 0620/31/o/n/12 \u00a9 ucles 2012for examiner\u2019s use3  the speed (rate) of a chemical reaction depends on a number of factors which include  temperature and the presence of a catalyst.  (a)  reaction speed increases as the temperature increases.  (i)  explain why reaction speed increases with temperature.   . ...   . ...   . .  [3]  (ii)  reactions involving enzymes do not follow the above pattern.   the following graph shows how the speed of such a reaction varies with temperature. speed temperature   suggest an explanation why initially the reaction speed increases then above a  certain temperature the speed decreases.   . ...   . .  [2]  (b)  an organic compound decomposes to give off nitrogen. c6h5n2cl (aq)  \u2192  c6h5cl (l)  +  n2(g)   the speed of this reaction can be determined by measuring the volume of nitrogen  formed at regular intervals. typical results are shown in the graph below. timevolume of nitrogen 00  (i)  the reaction is catalysed by copper.   sketch the graph for the catalysed reaction on the diagram above. [2]",
            "5": "5 0620/31/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  how does the speed of this reaction vary with time?   . .  [1]  (iii)   why does the speed of reaction vary with time?   . ...   . .  [2]  (c)  catalytic converters reduce the pollution from motor vehicles. oxides of nitrogen and carbon monoxideless harmful gases to atmosphere catalysts: rhodium, platinum, palladium  (i)  describe how carbon monoxide and the oxides of nitrogen are formed in car engines.   . ...   . ...   . ...   . .  [4]  (ii)  describe the reaction(s) inside the catalytic converter which change these pollutants  into less harmful gases. include at least one equation in your description.   . ...   . ...   . .  [3] [total: 17]",
            "6": "6 0620/31/o/n/12 \u00a9 ucles 2012for examiner\u2019s use4  silicon( iv) oxide, sio2, and zirconium( iv) oxide, zro2, are both macromolecules.   they have similar physical properties but silicon( iv) oxide is acidic and zirconium( iv) oxide  is amphoteric.  (a)  de\ufb01 ne the term macromolecule .   ...    ... ..  [1]  (b) (i)  predict three  physical properties of these two oxides.   . ...   . ...   . .  [3]  (ii)  name an element which has the same physical properties as these two oxides.   . .  [1]  (c) (i)  name a reagent that reacts with the oxides of both elements.   . .  [1]  (ii)  name a reagent that reacts with only one of the oxides.  reagent  . .  oxide which reacts  ...  [2] [total: 8]",
            "7": "7 0620/31/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use5  carbonyl chloride, coc l 2, is widely used in industry to make polymers, dyes and  pharmaceuticals.  (a)  carbonyl chloride was \ufb01 rst made in 1812 by exposing a mixture of carbon monoxide and  chlorine to bright sunlight. this is a photochemical reaction. co(g)  +  c l 2(g)  \u2192  coc l 2(g)  (i)  explain the phrase photochemical reaction .   . ...   . .  [2]  (ii)  give another example of a photochemical reaction and explain why it is important  either to the environment or in industry.   . ...   . ...   . .  [3]  (b)  carbonyl chloride is now made by the reversible reaction given below. co(g)  +  c l 2(g)    coc l 2(g)   the forward reaction is exothermic.   the reaction is catalysed by carbon within a temperature range of 50 to 150  \u00b0c.  (i)  predict the effect on the yield of carbonyl chloride of increasing the pressure.   explain your answer.   . ...   . .  [2]  (ii)  if the temperature is allowed to increase to above 200  \u00b0c, very little carbonyl chloride  is formed. explain why.   . ...   . .  [2]  (iii)  explain why a catalyst is used.   . .  [1]",
            "8": "8 0620/31/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (c)  the structural formula of carbonyl chloride is given below. cocl cl   draw a diagram showing the arrangement of the outer (valency) electrons in one molecule  of this covalent compound.   use o to represent an electron from a carbon atom.   use x to represent an electron from a chlorine atom.   use \u25cf to represent an electron from an oxygen atom. [3] [total: 13]",
            "9": "9 0620/31/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use6  a sandwich contains three of the main constituents of food. bread contains complex carbohydrates butter contains fat meat contains protein  (a) (i)   these constituents of food can be hydrolysed by boiling with acid or alkali.   complete the table. constituent of food product of hydrolysis protein fat complex carbohydrate [3]  (ii)  what type of synthetic polymer contains the same linkage as  fats,  .. proteins?  ..  [2] (b)  an incomplete structural formula of a protein is given below.   complete this diagram by inserting the linkages. insert linkageinsert linkage [2]  (c)  butter contains mainly saturated fats. fats based on vegetable oils, such as olive oil,  contain mainly unsaturated fats.   a small amount of fat was dissolved in an organic solvent.   describe how you could determine if the fat was saturated or unsaturated.   ...    ...    ... ..  [3] [total: 10]",
            "10": "10 0620/31/o/n/12 \u00a9 ucles 2012for examiner\u2019s use7  both strontium and sulfur have chlorides of the type xc l 2. the table below compares some  of their properties. strontium chloride sulfur chloride appearance white crystals red liquid formula src l 2 sc l 2 melting point  / \u00b0c 874 \u2013120 boiling point  / \u00b0c 1250 59 conductivity of liquid good poor solubility in waterdissolves to form a neutral solutionreacts to form a solution of ph  1  (a) (i)   use the data in the table to explain why sulfur chloride is a liquid at room temperature,  25  \u00b0c.   . ...   . .  [2]  (ii)  strontium is a metal and sulfur is a non-metal. explain why both have chlorides of  the type xc l 2.   the electron distribution of a strontium atom is 2 + 8 + 18 + 8 + 2.   . ...   . ...   . .  [2]  (iii)  deduce the name of the acidic compound formed when sulfur chloride reacts with  water.   . .  [1]  (iv)  explain the difference in the electrical conductivity of liquid strontium chloride and  liquid sulfur chloride.   . ...   . ...   . .  [3]",
            "11": "11 0620/31/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  strontium chloride-6-water can be made from the insoluble compound, strontium  carbonate, by the following reactions.  srco3(s)  +  2hc l (aq)  \u2192  src l 2(aq)  +  co2(g)  +  h2o(l)  src l 2 (aq)  +  6h2o(l)  \u2192  src l 2.6h2o(s)   the following method was used to prepare the crystals.  1  add excess strontium carbonate to hot hydrochloric acid.  2  filter the resulting mixture.  3  partially evaporate the filtrate and allow to cool.  4  filter off the crystals of src l 2.6h2o.  5  dry the crystals between filter papers.  (i)  how would you know when excess strontium carbonate had been added in step 1?   . ...   . .  [1]  (ii)  why is it necessary to \ufb01 lter the mixture in step 2?   . .  [1]  (iii)  in step 3, why partially evaporate the \ufb01 ltrate rather than evaporate to dryness?   . .  [1]  (c)  in the above experiment, 50.0  cm3 of hydrochloric acid of concentration 2.0  mol  / dm3 was  used. 6.4  g of src l 2.6h2o was made.  calculate the percentage yield.  number of moles of hc l used =   number of moles of src l 2.6h2o which could be formed =   mass of one mole of src l 2.6h2o is 267  g  theoretical yield of src l 2.6h2o = g  percentage yield = % [4] [total: 15]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/31/o/n/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w12_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) october/november 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib12 11_0620_32/2rp\u00a9 ucles 2012 *1580108680* for examiner\u2019s use 1 234567 total",
            "2": "2 0620/32/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  this question is concerned with the elements in period 5, rb to xe.  (a)  the electron distributions of some of these elements are given in the following list.  element a 2 + 8 + 18 + 8 + 2  element b 2 + 8 + 18 + 18 + 8  element c 2 + 8 + 18 + 18 + 5  element d 2 + 8 + 18 + 18 + 6  element e 2 + 8 + 18 + 18 + 4  element f 2 + 8 + 18 + 18 + 7  (i)  identify element c.  ...  [1]  (ii)  which element in the list does not form any compounds?   . .  [1]  (iii)  which element in the list forms a chloride of the type xc l 2?   . .  [1]  (iv)  which two elements would react together to form a compound of the type xy4?   . .  [1]  (v)  which element in the list would react with cold water to form an alkaline solution and  hydrogen?   . .  [1]  (b)  predict two differences in physical properties and two differences in chemical properties  between rubidium and the transition metal niobium.  physical  .   ...    ...    chemical   ...   ...    ... ..  [4] [total: 9]",
            "3": "3 0620/32/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  the diagram shows a heating curve for a sample of compound x. temperature  / \u00b0c time80 15 ab cd ef  (a)  is x a solid, a liquid or a gas at room temperature, 20  \u00b0c?   ... ..  [1]  (b)  write an equation for the equilibrium which exists in region bc.   ... ..  [2]  (c)  name the change of state which occurs in region de.   ... ..  [1]  (d)  explain how the curve shows that a pure sample of compound x was used.   ...    ... ..  [2] [total: 6]",
            "4": "4 0620/32/o/n/12 \u00a9 ucles 2012for examiner\u2019s use3  many organic compounds which contain a halogen have chloro, bromo or iodo in their name.  (a)  the following diagram shows the structure of 1-chloropropane. c h hh cc hhcl hh  (i)  draw the structure of an isomer of this compound. [1]  (ii)  describe how 1-chloropropane could be made from propane.   . ...   . .  [2]  (iii)  suggest an explanation why the method you have described in (ii) does not produce  a pure sample of 1-chloropropane.   . ...   . .  [2]  (b)  organic halides react with water to form an alcohol and a halide ion. ch3\u2013ch2\u2013i  +  h2o  \u2192  ch3\u2013ch2\u2013oh  +  i \u2013  (i)  describe how you could show that the reaction mixture contained an iodide ion.   . ...   . .  [2]  (ii)  name the alcohol formed when 1-chloropropane reacts with water.   . .  [1]",
            "5": "5 0620/32/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  the speed (rate) of reaction between an organic halide and water can be measured by  the following method.   a mixture of 10  cm3 of aqueous silver nitrate and 10  cm3 of ethanol is warmed to 60  \u00b0c.  drops of the organic halide are added and the time taken for a precipitate to form is measured.   silver ions react with the halide ions to form a precipitate of the silver halide. ag +(aq)  +  x\u2013(aq)  \u2192  agx(s)   typical results for four experiments, a, b, c and d, are given in the table. experiment organic halide number of drops time  / min a bromobutane 4 6 b bromobutane 8 3 c chlorobutane 4 80 d iodobutane 4 0.1  (i)  explain why it takes longer to produce a precipitate in experiment a than in b.   . ...   . .  [2]  (ii)  how does the order of reactivity of the organic halides compare with the order of  reactivity of the halogens?   . ...   . .  [2]  (iii)  explain why the time taken to produce a precipitate would increase if the experiments  were repeated at 50  \u00b0c.   . ...   . ...   . .  [3] [total: 15]",
            "6": "6 0620/32/o/n/12 \u00a9 ucles 2012for examiner\u2019s use4  iron is extracted from its ore, hematite, in the blast furnace. slag molten ironairfirebrick liningwaste gases raw materials: coke, climestone, caco 3 hematite, fe2o3  (a)  the temperature inside the blast furnace can rise to 2000  \u00b0c.   write an equation for the exothermic reaction which causes this high temperature.   ... ..  [1]  (b)  carbon monoxide is formed in the blast furnace. this reduces the ore hematite, fe2o3,  to iron.  (i)  explain how carbon monoxide is formed in the blast furnace.   . ...   . .  [2]  (ii)  write an equation for the reduction of hematite by carbon monoxide.   . .  [2]  (c)  explain why it is necessary to add limestone, calcium carbonate, to the blast furnace.  include an equation in your explanation.   ...    ...    ... ..  [3]",
            "7": "7 0620/32/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (d)  most of the iron from the blast furnace is converted into mild steel. a method of preventing  the steel from rusting is coating it with zinc.  (i)  what is the name of this method of rust prevention?   . .  [1]  (ii)  explain, using the idea of electron transfer, why zinc-coated steel does not rust even  when the coating is scratched and the steel is in contact with oxygen and water.   . ...   . ...   . ...   . .  [3] [total: 12]",
            "8": "8 0620/32/o/n/12 \u00a9 ucles 2012for examiner\u2019s use5  the food additive e220 is sulfur dioxide. it is a preservative for a variety of foods and drinks.  (a)  state two other uses of sulfur dioxide.   ...    ... ..  [2]  (b)  how is sulfur dioxide manufactured?   ...    ... ..  [2]  (c)  sulfur dioxide is a reductant (reducing agent). describe what you would see when  aqueous sulfur dioxide is added to acidi \ufb01 ed potassium manganate( vii).   ...    ... ..  [2]  (d)  sulfur dioxide can also be made by the reaction between a sul \ufb01 te and an acid. na2so3  +  2hc l  \u2192  2nac l  +  so2  +  h2o   excess hydrochloric acid was added to 3.15  g of sodium sul \ufb01 te. calculate the maximum  volume, measured at r.t.p., of sulfur dioxide which could be formed.  the mass of one mole of na2so3 is 126  g.   ...    ...    ... ..  [3] [total: 9]",
            "9": "9 0620/32/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use6  during electrolysis, ions move in the electrolyte and electrons move in the external circuit.  reactions occur at the electrodes.  (a)  the diagram shows the electrolysis of molten lithium iodide. molten lithium iodideelectrode electrode+\u2013 external circuit heat  (i)  draw an arrow on the diagram to show the direction of the electron \ufb02 ow in the  external circuit. [1]  (ii)  electrons are supplied to the external circuit. how and where is this done?   . ...   . .  [2]  (iii)  explain why solid lithium iodide does not conduct electricity but when molten it is a  good conductor.   . ...   . .  [1]  (b)  the results of experiments on electrolysis are shown in the following table. complete the  table. the \ufb01 rst line has been done as an example. electrolyte electrodesproduct at cathodeproduct at anodechange to electrolyte molten lithium iodide carbon lithium iodine used up aqueous copper( ii) sulfate platinum oxygen concentrated aqueous potassium chloridecarbon chlorine [4]",
            "10": "10 0620/32/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (c)  the diagram below shows the electrolysis of dilute sulfuric acid. hydrogen is formed at  the negative electrode (cathode) and oxygen at the positive electrode (anode) and the concentration of sulfuric acid increases. carbon cathode dilute sulfuric acid bubbles of hydrogen gasbubbles of oxygen gascarbon anode+\u2013   the ions present in the dilute acid are h+(aq), oh\u2013(aq) and so42\u2013(aq).  (i)  write an equation for the reaction at the negative electrode (cathode).   . .  [2]  (ii)  complete the equation for the reaction at the positive electrode (anode).  4oh\u2013(aq)  \u2192  o2(g)  +  .h2o(l)  +  ... [1]  (iii)  suggest an explanation of why the concentration of the sulfuric acid increases.   . .  [1]  (d)  in the apparatus used in (c), the power supply is removed and immediately replaced by  a voltmeter. carbon cathode dilute sulfuric acid bubbles of hydrogen gasbubbles of oxygen gascarbon anodevvoltmeter   a reading on the voltmeter shows that electrical energy is being produced. suggest an  explanation for how this energy is produced.   ...    ...    ... ..  [3] [total: 15]",
            "11": "11 0620/32/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use7  the alcohols form a homologous series. the \ufb01 rst member of this series is methanol, ch3oh.  (a) (i)   give the general formula of the alcohols.   . .  [1]  (ii)  the mass of one mole of an alcohol is 116  g. what is its formula?   show your reasoning.   . ...   . .  [2]  (iii)  draw a diagram showing the arrangement of the outer (valency) electrons in one  molecule of methanol.  use x to represent an electron from a carbon atom.  use o to represent an electron from a hydrogen atom. use \u25cf to represent an electron from an oxygen atom. [3]  (b)  methanol is manufactured using the following method.  ch 4(g)  +  h2o(g)  \u2192  co(g)  +  3h2(g) reaction 1  co(g)  +  2h2(g)    ch3oh(g) reaction 2  the conditions for reaction 2 are: pressure 100 atmospheres  catalyst a mixture of copper, zinc oxide and aluminium oxide temperature 250  \u00b0c   the forward reaction is exothermic.  (i)  why is high pressure used in reaction 2?   . ...   . .  [2]",
            "12": "12 0620/32/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (ii)  explain why using a catalyst at 250  \u00b0c is preferred to using a higher temperature of  350  \u00b0c and no catalyst.   . ...   . ...   . .  [3]  (c)  methanol is oxidised by atmospheric oxygen. this reaction is catalysed by platinum.  (i)  the products of this reaction include a carboxylic acid. give its name and structural  formula.  name  ...  structural formula showing all bonds [2]  (ii)  deduce the name of the ester formed by the reaction of methanol with the carboxylic  acid named in (i).   . .  [1] [total: 14]",
            "13": "13 0620/32/o/n/12blank page \u00a9 ucles 2012",
            "14": "14 0620/32/o/n/12blank page \u00a9 ucles 2012",
            "15": "15 0620/32/o/n/12blank page \u00a9 ucles 2012",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/32/o/n/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w12_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. a copy of the periodic table is printed on page 16. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) october/november 2012  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib12 11_0620_33/3rp\u00a9 ucles 2012 *8141362656* for examiner\u2019s use 1 234567 total",
            "2": "2 0620/33/o/n/12blank page \u00a9 ucles 2012",
            "3": "3 0620/33/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use1  for each of the following, select an element from period 4, potassium to krypton, which  matches the description.  (a)  a metal that reacts rapidly with cold water to form a compound of the type m(oh)2 and  hydrogen.   ... ..  [1]  (b)  its only oxidation state is 0.    [1]  (c)  it has a macromolecular oxide, xo2, which has similar physical properties to those of  diamond.   ... ..  [1]  (d)  this is one of the metals alloyed with iron in stainless steel.  .  [1]  (e)  it can be reduced to an ion of the type x\u2013.  ..  [1]  (f)  it can form a covalent hydride having the formula h2x.  ..  [1]  (g)  its soluble salts are blue and its oxide is black.  ..  [1]  (h)  it is a liquid at room temperature.  ...  [1] [total: 8] 2 (a)  state a use for each of the following gases.  (i)  chlorine    [1]  (ii)  argon  ...  [1]  (iii)  ethene  ..  [1]  (iv)  oxygen  .  [1]  (b)  describe how oxygen is obtained from air.   ...    ... ..  [2] [total: 6]",
            "4": "4 0620/33/o/n/12 \u00a9 ucles 2012for examiner\u2019s use3 (a)  a small amount of liquid bromine is added to a container which is then sealed. br2(l)  \u2192  br2(g)   use the ideas of the kinetic theory to explain why, after about an hour, the bromine  molecules have spread uniformly to occupy the whole container.   ...    ...    ... ..  [3]  (b)  the diagrams below show simple experiments on the speed of diffusion of gases. diagram 1 diagram 2porous pot allows gasmoleculesto diffuse airporous pot airairhydrogen large beaker large beakercarbon dioxidesame level colouredliquidhigher level diagram 3higherlevel air",
            "5": "5 0620/33/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use  complete the following explanations. diagram 1 has been done for you.  diagram 1   there is air inside and outside the porous pot so the rate of diffusion of air into the pot is  the same as the rate of diffusion of air out of the pot. the pressure inside and outside the pot is the same so the coloured liquid is at the same level on each side of the tube.  diagram 2   ...    ...    ...    ... ..  [3]  diagram 3   ...    ...    ...    ... ..  [3] [total: 9]",
            "6": "6 0620/33/o/n/12 \u00a9 ucles 2012for examiner\u2019s use4  zinc alloys have been used for over 2500 years.  (a) (i)   explain the phrase zinc alloy .   . ...   . .  [1]  (ii)  making alloys is still a major use of zinc. state one other large scale use of zinc.   . .  [1]  (iii)  describe the bonding in a typical metal, such as zinc, and then explain why it is  malleable. you may use a diagram to illustrate your answer.   . ...   . ...   . .  [3]  (iv)  suggest why the introduction of a different atom into the structure makes the alloy  less malleable than the pure metal.   . ...   . .  [2]  (b)  zinc metal is made by the reduction of zinc oxide. the major ore of zinc is zinc blende,  zns. zinc blende contains silver and lead compounds as well as zinc sul \ufb01 de.   zinc blende is converted into impure zinc oxide by heating it in air. 2zns  +  3o2  \u2192  2zno  +  2so2  (i)  describe how zinc oxide is reduced to zinc.   . .  [1]  (ii)  some of the zinc oxide is dissolved in sulfuric acid to make aqueous zinc sulfate.  write a balanced symbol equation for this reaction.   . .  [2]",
            "7": "7 0620/33/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (iii)  this impure solution of zinc sulfate contains zinc ions, silver( i) ions and lead ions.  explain why the addition of zinc powder produces pure zinc sulfate solution.  include at least one ionic equation in your explanation.   . ...   . ...   . ...   . ...   . .  [4]  (iv)  describe how zinc metal can be obtained from zinc sulfate solution by electrolysis.  a labelled diagram is acceptable. include all the products of this electrolysis. the  electrolysis is similar to that of copper( ii) sulfate solution with inert electrodes. [4] [total: 18]",
            "8": "8 0620/33/o/n/12 \u00a9 ucles 2012for examiner\u2019s use5  propenoic acid is an unsaturated carboxylic acid. the structural formula of propenoic acid is  given below. cch hcooh h  (a) (i)   describe how you could show that propenoic acid is an unsaturated compound.  test   .  result  ..    . .  [2]  (ii)  without using an indicator, describe how you could show that a compound is an  acid.  test   .  result  ..    . .  [2]  (b)  propenoic acid reacts with ethanol to form an ester. deduce the name of this ester. draw  its structural formula.  name of ester    structural formula showing all bonds [3]  (c)  an organic compound has a molecular formula c6h8o4. it is an unsaturated carboxylic  acid. one mole of the compound reacts with two moles of sodium hydroxide.  (i)  explain the phrase molecular formula .   . ...   . .  [2]",
            "9": "9 0620/33/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (ii)  one mole of this carboxylic acid reacts with two moles of sodium hydroxide.   how many moles of \u2013cooh groups are there in one mole of this compound?   . .  [1]  (iii)  what is the formula of another functional group in this compound?   . .  [1]  (iv)  deduce a structural formula of this compound. [1] [total: 12]",
            "10": "10 0620/33/o/n/12 \u00a9 ucles 2012for examiner\u2019s use6  until recently, arsenic poisoning, either deliberate or accidental, has been a frequent cause  of death. the symptoms of arsenic poisoning are identical with those of a common illness, cholera. a reliable test was needed to prove the presence of arsenic in a body.  (a)  in 1840, marsh devised a reliable test for arsenic. hydrochloric acid h2 and arsine burning pieces of zinc and arsenic compoundblack stainshows presenceof arseniccold surface   hydrogen is formed in this reaction. any arsenic compound reacts with this hydrogen to  form arsine which is arsenic hydride, ash3.   the mixture of hydrogen and arsine is burnt at the jet and arsenic forms as a black stain  on the glass.  (i)  write an equation for the reaction which forms hydrogen.   . .  [2]  (ii)  draw a diagram which shows the arrangement of the outer (valency) electrons in  one molecule of the covalent compound arsine.  the electron distribution of arsenic is 2 + 8 + 18 + 5.   use x to represent an electron from an arsenic atom.   use o to represent an electron from a hydrogen atom. [2]",
            "11": "11 0620/33/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  another hydride of arsenic has the composition below.  arsenic    97.4  % hydrogen    2.6  %  (i)  calculate the empirical formula of this hydride from the above data .  show your working.   . ...   . ...[2]  (ii)  the mass of one mole of this hydride is 154  g. what is its molecular formula?   . .  [1]  (iii)  deduce the structural formula of this hydride. [1]  (c)  hair is a natural protein. hair absorbs arsenic from the body. analysis of the hair provides  a measurement of a person\u2019s exposure to arsenic. to release the absorbed arsenic for analysis, the protein has to be hydrolysed.  (i)  what is the name of the linkage in proteins?   . .  [1]  (ii)  name a reagent which can be used to hydrolyse proteins.   . .  [1]  (iii)  what type of compound is formed by the hydrolysis of proteins?   . .  [1]",
            "12": "12 0620/33/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (d)  in the 19th century, a bright green pigment, copper( ii) arsenate( v) was used to kill rats  and insects. in damp conditions, micro-organisms can act on this compound to produce the very poisonous gas, arsine.  (i)  suggest a reason why it is necessary to include the oxidation states in the name of  the compound.   . ...   . .  [1]  (ii)  the formula for the arsenate( v) ion is aso43\u2013. complete the ionic equation for the  formation of copper( ii) arsenate( v). ..cu2+  +  ..aso43\u2013  \u2192  .. [2] [total: 14]",
            "13": "13 0620/33/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use7  ammonia is made by the haber process. n2(g)  +  3h2(g)    2nh3(g)  (a)  state one major use of ammonia.   ... ..  [1]  (b)  describe how hydrogen is obtained for the haber process.   ...    ...    ... ..  [3]  (c)  this reaction is carried out at a high pressure, 200 atmospheres.   state, with an explanation for each, two advantages of using a high pressure.   ...    ...    ...    ...    ... ..  [5]  (d) (i)   what is the difference between an endothermic and an exothermic reaction?   . ...   . .  [1]",
            "14": "14 0620/33/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (ii)  bond breaking is an endothermic process. bond energy is the amount of energy  needed to break or form one mole of the bond. complete the table and explain why the forward reaction is exothermic. n n  +  3 h h 2 h n h h bondbond energy kj / molenergy change kjexothermic or endothermic n  n 944 +944 endothermic h \u2014  h 436 3 \u00d7 436 = +1308 n \u2014  h 388   ...    ... ..  [3] [total: 13]",
            "15": "15 0620/33/o/n/12blank page \u00a9 ucles 2012",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/33/o/n/12 \u00a9 ucles 2012 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w12_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test october/november 2012  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib12 11_0620_51/3rp\u00a9 ucles 2012 *7579196361* for examiner\u2019s use total",
            "2": "2 0620/51/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  you are going to investigate the speed of reaction when iodine is produced by the reaction                      of solution l with potassium iodide at different temperatures.   read all the instructions below carefully before starting the experiments.  instructions   you are going to carry out \ufb01 ve experiments.  (a)  experiment 1   fill the burette with the aqueous solution l provided to the 0.0  cm3 mark.   add 10  cm3 of solution l from the burette into a boiling tube. record the initial temperature  of the solution in the table.   use a measuring cylinder to pour 5  cm3 of the aqueous potassium iodide and 3  cm3 of  aqueous sodium thiosulfate provided into a second boiling tube. add 2  cm3 of the starch  solution provided to this boiling tube and shake the mixture.    add the mixture in the second boiling tube to the solution l in the \ufb01 rst boiling tube, shake  the mixture and start the clock. these chemicals react to form iodine which reacts with starch. when a blue colour \ufb01 rst appears stop the clock and record the time in the table.  measure and record the \ufb01 nal temperature of the mixture in the table.  (b)  experiment 2   discard the contents of the boiling tube and rinse both boiling tubes with distilled water.    use a measuring cylinder to pour 5  cm3 of aqueous potassium iodide and 3  cm3 of  aqueous sodium thiosulfate into the \ufb01 rst boiling tube. add 2  cm3 of the starch solution  and shake the mixture.   add 10  cm3 of solution l from the burette into the second boiling tube. heat solution l  to about 40  \u00b0c stirring with a thermometer. record the temperature of solution l in the  table.   add the mixture in the \ufb01 rst boiling tube to the solution l, shake the mixture and start the  clock. when a blue colour \ufb01 rst appears, stop the clock and record the time in the table.  measure and record the \ufb01 nal temperature of the mixture in the table.  (c) experiment 3   repeat experiment 2, heating solution l to about 50  \u00b0c.  (d)  experiment 4   repeat experiment 2, heating solution l to about 60  \u00b0c.  (e)  experiment 5   repeat experiment 2, heating solution l to about 70  \u00b0c.",
            "3": "3 0620/51/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (f)  complete the table of results. experimenttemperature of  solution l / \u00b0c\ufb01 nal temperature  of mixture  / \u00b0caverage  temperature  / \u00b0ctime for blue colour  to appear  / s 1 2345 [5]  (g)  plot the results on the grid below and draw a smooth line graph. 300 250200150100 50 0 0 1 02 03 04 05 06 07 08 0time  / s average temperature  / \u00b0c [5]",
            "4": "4 0620/51/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (h)  from your graph , work out the time taken for the blue colour to \ufb01 rst appear if solution l  was heated to 80  \u00b0c. the \ufb01 nal temperature of the reaction mixture was 64  \u00b0c.   show on the grid  how you obtained your answer.   ... ..  [3]  (i)  suggest the purpose of the starch solution in the experiments.   ... ..  [1]  (j) (i)  in which experiment was the reaction speed fastest?   . .  [1]  (ii)  explain, using ideas about particles, why this experiment was the fastest.   . ...   . .  [2]  (k)  predict the effect on the time and speed of the reaction in experiment 5 if it was repeated  using a less concentrated solution of l.  time   ...  speed  ... ...  [2]  (l)  why was a burette used to measure solution l instead of a measuring cylinder?   ...    ... ..  [1] [total: 20]",
            "5": "5 0620/51/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  you are provided with a mixture of two solids, m and n.   solid m is water-soluble and solid n is insoluble.   carry out the following tests on the mixture, recording all of your observations in the table.   conclusions must not be written in the table. tests observations add about 15  cm3 of distilled water to the  mixture in a boiling tube.stopper and shake the boiling tube for one minute. filter the contents of the boiling tube, keeping the \ufb01 ltrate and residue for the following  tests. tests on the \ufb01 ltrate  divide the \ufb01 ltrate into \ufb01 ve portions in \ufb01 ve test-tubes. (a)  use ph indicator paper to test the ph of  the \ufb01 ltrate.   [1] (b) (i)   to the second portion of the \ufb01 ltrate,  add drops of aqueous sodium hydroxide and shake the mixture.    now add excess aqueous sodium  hydroxide to the test-tube.  (ii)   to the third portion of the \ufb01 ltrate,  add drops of aqueous ammonia and shake the mixture.    now add excess aqueous ammonia  to the test-tube. ..   [3]  ..   [3] (c)  to the fourth portion of the \ufb01 ltrate, add  about 1  cm3 of dilute nitric acid followed by  silver nitrate solution.   [1] (d)  to the \ufb01 fth portion of the \ufb01 ltrate, add  about 1  cm3 of dilute nitric acid followed by  barium nitrate solution.   [2]",
            "6": "6 0620/51/o/n/12 \u00a9 ucles 2012for examiner\u2019s usetests observations tests on the residue  use a spatula to transfer some of the residue  into two test-tubes. (e)  to the \ufb01 rst sample of the residue, add  about 3  cm3 of dilute hydrochloric acid. boil  the mixture for about two minutes and test the gas given off with damp blue litmus paper. ..   [2] (f)  to the second sample of the residue,  add about 3  cm3 of aqueous hydrogen  peroxide.   test the gas given off. ..   [3]  (g)  what conclusions can you draw about solid m?   ...    ... ..  [2]  (h)  identify the gas given off in test (f).   ... ..  [1]  (i)  what conclusions can you draw about solid n?   ...    ...    ... ..  [2] [total: 20]",
            "7": "7 0620/51/o/n/12blank page \u00a9 ucles 2012",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/51/o/n/12notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2012"
        },
        "0620_w12_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test october/november 2012  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib12 11_0620_52/fp\u00a9 ucles 2012 *9139900259* for examiner\u2019s use total",
            "2": "2 0620/52/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  you are going to investigate the speed of reaction when iodine is produced by the reaction                      of solution l with potassium iodide at different temperatures.   read all the instructions below carefully before starting the experiments.  instructions   you are going to carry out \ufb01 ve experiments.  (a)  experiment 1   fill the burette with the aqueous solution l provided to the 0.0  cm3 mark.   add 10  cm3 of solution l from the burette into a boiling tube. record the initial temperature  of the solution in the table.   use a measuring cylinder to pour 5  cm3 of the aqueous potassium iodide and 3  cm3 of  aqueous sodium thiosulfate provided into a second boiling tube. add 2  cm3 of the starch  solution provided to this boiling tube and shake the mixture.    add the mixture in the second boiling tube to the solution l in the \ufb01 rst boiling tube, shake  the mixture and start the clock. these chemicals react to form iodine which reacts with starch. when a blue colour \ufb01 rst appears stop the clock and record the time in the table.  measure and record the \ufb01 nal temperature of the mixture in the table.  (b)  experiment 2   discard the contents of the boiling tube and rinse both boiling tubes with distilled water.    use a measuring cylinder to pour 5  cm3 of aqueous potassium iodide and 3  cm3 of  aqueous sodium thiosulfate into the \ufb01 rst boiling tube. add 2  cm3 of the starch solution  and shake the mixture.   add 10  cm3 of solution l from the burette into the second boiling tube. heat solution l  to about 40  \u00b0c stirring with a thermometer. record the temperature of solution l in the  table.   add the mixture in the \ufb01 rst boiling tube to the solution l, shake the mixture and start the  clock. when a blue colour \ufb01 rst appears, stop the clock and record the time in the table.  measure and record the \ufb01 nal temperature of the mixture in the table.  (c) experiment 3   repeat experiment 2, heating solution l to about 50  \u00b0c.  (d)  experiment 4   repeat experiment 2, heating solution l to about 60  \u00b0c.  (e)  experiment 5   repeat experiment 2, heating solution l to about 70  \u00b0c.",
            "3": "3 0620/52/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (f)  complete the table of results. experimenttemperature of  solution l / \u00b0c\ufb01 nal temperature  of mixture  / \u00b0caverage  temperature  / \u00b0ctime for blue colour  to appear  / s 1 2345 [5]  (g)  plot the results on the grid below and draw a smooth line graph. 300 250200150100 50 0 0 1 02 03 04 05 06 07 08 0time  / s average temperature  / \u00b0c [5]",
            "4": "4 0620/52/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (h)  from your graph , work out the time taken for the blue colour to \ufb01 rst appear if solution l  was heated to 80  \u00b0c. the \ufb01 nal temperature of the reaction mixture was 64  \u00b0c.   show on the grid  how you obtained your answer.   ... ..  [3]  (i)  suggest the purpose of the starch solution in the experiments.   ... ..  [1]  (j) (i)  in which experiment was the reaction speed fastest?   . .  [1]  (ii)  explain, using ideas about particles, why this experiment was the fastest.   . ...   . .  [2]  (k)  predict the effect on the time and speed of the reaction in experiment 5 if it was repeated  using a less concentrated solution of l.  time   ...  speed  ... ...  [2]  (l)  why was a burette used to measure solution l instead of a measuring cylinder?   ...    ... ..  [1] [total: 20]",
            "5": "5 0620/52/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  you are provided with a mixture of two solids, m and n.   solid m is water-soluble and solid n is insoluble.   carry out the following tests on the mixture, recording all of your observations in the table.   conclusions must not be written in the table. tests observations add about 15  cm3 of distilled water to the  mixture in a boiling tube.stopper and shake the boiling tube for one minute. filter the contents of the boiling tube, keeping the \ufb01 ltrate and residue for the following  tests. tests on the \ufb01 ltrate  divide the \ufb01 ltrate into \ufb01 ve portions in \ufb01 ve test-tubes. (a)  use ph indicator paper to test the ph of  the \ufb01 ltrate.   [1] (b) (i)   to the second portion of the \ufb01 ltrate,  add drops of aqueous sodium hydroxide and shake the mixture.    now add excess aqueous sodium  hydroxide to the test-tube.  (ii)   to the third portion of the \ufb01 ltrate,  add drops of aqueous ammonia and shake the mixture.    now add excess aqueous ammonia  to the test-tube. ..   [3]  ..   [3] (c)  to the fourth portion of the \ufb01 ltrate, add  about 1  cm3 of dilute nitric acid followed by  silver nitrate solution.   [1] (d)  to the \ufb01 fth portion of the \ufb01 ltrate, add  about 1  cm3 of dilute nitric acid followed by  barium nitrate solution.   [2]",
            "6": "6 0620/52/o/n/12 \u00a9 ucles 2012for examiner\u2019s usetests observations tests on the residue  use a spatula to transfer some of the residue  into two test-tubes. (e)  to the \ufb01 rst sample of the residue, add  about 3  cm3 of dilute hydrochloric acid. boil  the mixture for about two minutes and test the gas given off with damp blue litmus paper. ..   [2] (f)  to the second sample of the residue,  add about 3  cm3 of aqueous hydrogen  peroxide.   test the gas given off. ..   [3]  (g)  what conclusions can you draw about solid m?   ...    ... ..  [2]  (h)  identify the gas given off in test (f).   ... ..  [1]  (i)  what conclusions can you draw about solid n?   ...    ...    ... ..  [2] [total: 20]",
            "7": "7 0620/52/o/n/12blank page \u00a9 ucles 2012",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/52/o/n/12notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2012"
        },
        "0620_w12_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test october/november 2012  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 8 printed pages. [turn overib12 11_0620_53/4rp\u00a9 ucles 2012 *3666446597* for examiner\u2019s use total",
            "2": "2 0620/53/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  you are going to investigate what happens when aqueous sodium hydroxide reacts with two  different acids, g and h.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a) experiment 1   use a measuring cylinder to pour 20  cm3 of solution g into the polystyrene cup provided.  put the cup into a 250  cm3 beaker for support. measure the initial temperature of the  solution and record it in the table below.   fill the burette with the aqueous sodium hydroxide provided to the 0.0  cm3 mark.   add 5.0  cm3 of aqueous sodium hydroxide to the solution of g in the cup and stir the  mixture.   measure and record the maximum temperature of the solution in the table below. add  a further 5.0  cm3 of aqueous sodium hydroxide to the cup and stir the mixture. measure  and record the maximum temperature of the mixture in the table below.   continue to add 5.0  cm3 portions of aqueous sodium hydroxide to the cup, until a total  volume of 40  cm3 of aqueous sodium hydroxide has been added. stir after each addition  and measure and record the maximum temperatures in the table.   pour the solution away and rinse the polystyrene cup. volume of aqueous sodium hydroxide added  / cm3maximum temperature of solution in polystyrene cup  / \u00b0c 0.0 5.0 10.015.020.025.030.035.040.0 [3]",
            "3": "3 0620/53/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  experiment 2   repeat experiment 1 using 20  cm3 of solution h instead of 20  cm3 of solution g.   record your results in the table below. volume of aqueous sodium hydroxide added  / cm3maximum temperature of solution in polystyrene cup  / \u00b0c 0.0 5.0 10.015.020.025.030.035.040.0 [3]",
            "4": "4 0620/53/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.  clearly label your graphs. 50 40 30 20 10 0 5 10 15 20 25 30 35 40 volume of aqueous sodium hydroxide  / cm3maximum temperature of solution  / \u00b0c [6]  (d)  use your graph  to estimate the maximum temperature of the reaction mixture when 8 cm3 of aqueous sodium hydroxide were added to 20  cm3 of the solution of acid g.   show clearly on the graph  how you worked out your answer.   ... ..  [2]  (e)  what type of chemical reaction, other than neutralisation, occurs when acid h reacts with  aqueous sodium hydroxide?   ... ..  [1]",
            "5": "5 0620/53/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (f) (i)   in which experiment is the temperature change greater?   . .  [1]  (ii)  suggest why the temperature change is greater in this experiment.   . ...   . .  [1]  (g)  predict the temperature of the mixture in experiment 2 after two hours. explain your  answer.   ...    ... ..  [2] [total: 19]",
            "6": "6 0620/53/o/n/12 \u00a9 ucles 2012for examiner\u2019s use2  you are provided with two salt solutions, j and k.   carry out the following tests on j and k, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solution j (a)  describe the appearance of j.   [1] (b)  to about 1  cm3 of the solution, add an equal  volume of aqueous sodium hydroxide.   leave to stand for \ufb01 ve minutes. note any  changes. ..  ..  [2] (c)  to about 1  cm3 of the solution, add an  equal volume of hydrogen peroxide.   test the gas given off. ..  ..  [3] (d)  to about 1  cm3 of the solution, add about 1 cm3 of aqueous ammonia.   [1] (e)  to about 1  cm3 of the solution, add a  few drops of dilute nitric acid followed by aqueous silver nitrate.   [1] (f)  to about 1  cm3 of the solution, add a  few drops of dilute nitric acid followed by barium nitrate solution.   [2]",
            "7": "7 0620/53/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s usetests observations tests on solution k (g)  describe the appearance of k.   [1] (h)  to about 1  cm3 of the solution, add 5 drops  of aqueous sodium hydroxide.   now add excess aqueous sodium  hydroxide. .  .  [3] (i)  to about 1  cm3 of the solution, add about 2 cm3 of aqueous sodium hydroxide  and one spatula measure of aluminium powder. heat the mixture gently.   test the gas given off. ..   [2]  (j)  what conclusions can you draw about solution j?   ...    ... ..  [3]  (k)  what conclusions can you draw about solution k?   ...    ... ..  [2] [total: 21]",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/53/o/n/12notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2012"
        },
        "0620_w12_qp_61.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical october/november 2012  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib12 11_0620_61/2rp\u00a9 ucles 2012 *5673438807* for examiner\u2019s use 1 23456 total",
            "2": "2 0620/61/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  a student reacted dry ammonia gas with hot copper( ii) oxide.   the apparatus used is shown below.   the equation for the reaction is 2nh3  +  3cuo  \u2192  3cu  +  n2  +  3h2o dry ammonia gasnitrogen and water vapourcopper( ii) oxide  (a)  indicate with an arrow where the heat is applied. [1]  (b)  the colour of the copper( ii) oxide would change  from ...  to  ... [2] (c)  draw a labelled diagram to show how liquid water could be obtained from the water  vapour produced. [2]  (d)  suggest the effect of nitrogen on a lighted splint.   ... ... [1] [total: 6]",
            "3": "3 0620/61/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  electricity was passed through aqueous copper( ii) sulfate using inert electrodes as shown in  the diagram below.   copper was deposited at one of the electrodes. aqueous copper( ii) sulfate  (a)  name a suitable material for the electrodes.   ... ..  [1]  (b)  at which electrode was copper deposited?   ... ..  [1]  (c)  give one other observation seen during the electrolysis.   ... ..  [1]   the electrode at which copper was deposited was removed at intervals, washed, dried and  weighed.   the results are shown in the table on page 4.  (d) (i)   suggest how the electrode was washed?   . .  [1]  (ii)  how could the electrode be dried quickly?   . .  [1]",
            "4": "4 0620/61/o/n/12 \u00a9 ucles 2012for examiner\u2019s use table of results time  / minmass of electrode  / gtotal increase in mass  / g 0 3.75 0.00 10 4.00 0.2520 4.25 0.5030 4.5040 4.7550 4.9060 4.9070 4.90  (e)  complete the table by calculating the total increase in mass for the remaining time  intervals. [1]  (f)  plot the points on the grid below. draw a graph with two intersecting straight lines. 1.20 1.000.800.600.40 0.20 0.00 0 1 02 03 04 05 06 07 0 time  / mintotal increasein mass  / g [3]",
            "5": "5 0620/61/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (g)  suggest why the last three readings were the same.   ...    ... ..  [1] [total: 10]",
            "6": "6 0620/61/o/n/12 \u00a9 ucles 2012for examiner\u2019s use3  a student carried out an experiment to \ufb01 nd the mass of magnesium oxide formed when  magnesium burns in air.   a strip of magnesium ribbon was loosely coiled and placed in a weighed crucible, which was  then reweighed.   the crucible was heated strongly for several minutes. during the heating, the crucible lid was  lifted and replaced several times as in the diagram below. heatcrucible   the magnesium was converted into magnesium oxide. after cooling, the crucible and contents  were reweighed.  (a)  describe the appearance of the  (i) magnesium  ..  [1]  (ii) magnesium oxide.  ...  [1]  (b)  name the element that reacted with the magnesium.   ... ..  [1]  (c)  why was the lid lifted during heating?   ... ..  [1]  (d)  suggest why the mass of the magnesium oxide was found to be lower  than expected.   ...    ... ..  [2] [total: 6]",
            "7": "7 0620/61/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use4  a student investigated the speed of reaction when iodine was produced by the reaction of  solution l with potassium iodide at different temperatures.   five experiments were carried out.  experiment 1   a burette was \ufb01 lled with the aqueous solution l to the 0.0  cm3 mark.   10.0  cm3 of solution l was added from the burette into a boiling tube and the initial temperature  of the solution was measured.   using a measuring cylinder, 5  cm3 of aqueous potassium iodide and 3  cm3 of aqueous sodium  thiosulfate were poured into a second boiling tube. starch solution was added to this boiling tube and the mixture shaken.   the mixture in the second boiling tube was added to the solution l, shaken and the clock  started. these chemicals reacted to form iodine which reacted with the starch. when a blue colour appeared, the clock was stopped and the time measured and recorded in the table. the \ufb01 nal temperature of the mixture was measured.  experiment 2   experiment 1 was repeated but solution l was heated to about 40  \u00b0c. the temperature of the  solution was measured before adding the mixture in the second boiling tube.   when a blue colour appeared, the clock was stopped and the time measured and recorded  in the table. the \ufb01 nal temperature of the mixture was measured.   experiment 3   experiment 2 was repeated, heating solution l to about 50  \u00b0c.  experiment 4  experiment 2 was repeated, heating solution l to about 60  \u00b0c.  experiment 5   experiment 2 was repeated, heating solution l to about 70  \u00b0c.",
            "8": "8 0620/61/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (a)   use the thermometer diagrams in the table to record the temperatures and complete the  table. 1 234thermometer diagramthermometer diagramexperiment time  / sfinal temperature / \u00b0caverage temperature / \u00b0cinitial temperature / \u00b0c 30 25 20 45 40 35 50 45 40 65 60 5530 25 20 30 25 20 45 40 35 45 40 35 5215 105 604035 75 70 6550 45 40 [5]",
            "9": "9 0620/61/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  plot the results on the grid below and draw a smooth line graph. 250 200150100 50 0 0 1 02 03 04 05 06 07 08 0 average temperature  / \u00b0ctime  / s [5]  (c)  from your graph , work out the time taken for the blue colour to appear if solution l was  heated to 80  \u00b0c. the \ufb01 nal temperature of the reaction mixture was 64  \u00b0c.   show clearly on the grid  how you obtained your answer.   ... ..  [2]  (d)  suggest the purpose of the starch solution in the experiments.   ... ..  [1]  (e) (i)  in which experiment was the reaction speed fastest?   . .  [1]  (ii)  explain, using ideas about particles, why this experiment was the fastest.   . ...   . .  [2]",
            "10": "10 0620/61/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (f)  predict the effect on the time and speed of the reaction in experiment 5 if it was repeated  using a less concentrated solution of l.  time   ...  speed  ... ...  [2]  (g)  why was a burette used to measure solution l instead of a measuring cylinder?   ...    ... ..  [1] [total: 19]",
            "11": "11 0620/61/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use5  a mixture of two solids, m and n, was analysed.   solid m was zinc sulfate which is water-soluble and solid n was insoluble.   the tests on the mixture, and some of the observations, are in the table.   complete the observations in the table. tests observations distilled water was added to the mixture in a  boiling tube and shaken. the contents of the tube were \ufb01 ltered and the \ufb01 ltrate and residue  kept for the following tests. tests on the \ufb01 ltrate the \ufb01 ltrate was divided into four portions. (a) (i)  drops of aqueous sodium hydroxide  were added to the \ufb01 rst portion of the  \ufb01 ltrate.    excess aqueous sodium hydroxide  was then added.  (ii)  drops of aqueous ammonia were  added to the second portion of the \ufb01 ltrate.    excess aqueous ammonia was then  added. ...  .  [3]  ...  .  [2] (b)  about 1  cm3 of dilute nitric acid followed  by silver nitrate solution was added to the third portion of the \ufb01 ltrate.  .  [1] (c)  about 1  cm3 of dilute nitric acid followed by  barium nitrate solution was added to the fourth portion of the \ufb01 ltrate.  .  [2]",
            "12": "12 0620/61/o/n/12 \u00a9 ucles 2012for examiner\u2019s usetests observations tests on the residue (d)  appearance of the residue. black solid (e)  dilute hydrochloric acid was added to  a little of the residue. the mixture was heated and the gas given off was tested with damp blue litmus paper.effervescence pungent gas, bleached litmus paper (f)  aqueous hydrogen peroxide was added  to a little of the residue. the gas given off was tested.effervescence glowing splint relit  (g)  identify the gas given off in test (e).   ... ..  [1]  (h)  identify the gas given off in test (f).   ... ..  [1]  (i)  what conclusions can you draw about solid n?   ...    ... ..  [2] [total: 12]",
            "13": "13 0620/61/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use6 which is the more pure - limestone or marble?   calcium carbonate is found in limestone and in marble. all carbonates react with hydrochloric  acid to form chlorides. calcium carbonate is insoluble in water but calcium chloride is water soluble.   most impurities in limestone and marble are insoluble.   plan an experiment to \ufb01 nd out which of limestone and marble contain most insoluble impurities.   you are provided with common laboratory apparatus.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [7] [total: 7]",
            "14": "14 0620/61/o/n/12blank page \u00a9 ucles 2012",
            "15": "15 0620/61/o/n/12blank page \u00a9 ucles 2012",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/61/o/n/12 \u00a9 ucles 2012blank page"
        },
        "0620_w12_qp_62.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical october/november 2012  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib12 11_0620_62/2rp\u00a9 ucles 2012 *6376664364* for examiner\u2019s use 1 234 5 6 total",
            "2": "2 0620/62/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  the apparatus below was used to prepare hydrogen and measure the volume of gas  produced. water metaldilutehydrochloricacid  (a)  complete the boxes to identify the pieces of apparatus labelled. [2]  (b) (i)   why would copper metal not be used in this preparation?   . ...  (ii)  name a suitable metal that could be used in this preparation.   . .  [2]  (c)  draw a labelled diagram to show a different  method of collecting and measuring the  hydrogen. [2]  (d)  state a test for hydrogen.  test     result  .. .  [2] [total: 8]",
            "3": "3 0620/62/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  hydrogen peroxide breaks down to form oxygen. a student investigated the speed of the  breakdown of aqueous solutions of hydrogen peroxide of different concentrations, using 1  g  of powdered manganese( iv) oxide. the temperature was kept constant at 25  \u00b0c. she plotted  her results on the grid below. 0.6 0.50.40.30.20.10.0 0.0 0.1 0.2 0.3 concentration of hydrogen peroxide in  mol  / dm30.4 0.5speed of reactionin cm 3 / s  (a)  draw a straight line graph on the grid. [2]  (b)  from your graph , work out the speed of the reaction when the concentration of hydrogen  peroxide is 0.5  mol  / dm3. show clearly on the grid  how you obtained your answer.   ... ..  [2]  (c)  sketch on the grid the graph you would expect if the experiments were repeated at 10  \u00b0c. [1]  (d) (i)   what is the function of the manganese( iv) oxide?   . .  [1]  (ii)  suggest the effect of repeating the investigation using 1  g of lumps of manganese( iv)  oxide. explain your answer.  effect  ..   explanation  ..  [2] [total: 8]",
            "4": "4 0620/62/o/n/12 \u00a9 ucles 2012for examiner\u2019s use3  a student prepared zinc nitrate from zinc oxide.   the zinc nitrate was then heated to change it back into zinc oxide.   the procedure followed was in three steps.  step 1  some zinc oxide was put into a weighed evaporating dish and the mass noted. the  zinc oxide was transferred into a beaker.  step 2  a dilute acid was slowly added to the beaker until all the zinc oxide had reacted. zinc  nitrate solution was produced.  step 3  the solution was evaporated to dryness in the evaporating dish. the resulting solid  was heated in a fume cupboard. after cooling, the dish was weighed. the dish was then heated again, cooled and reweighed.   the mass of zinc oxide produced was not the same as the amount used at the start.  (a)  what could be used to transfer the zinc oxide in step 1?   ... ..  [1]  (b)  name the acid used in step 2.   ... ..  [1]  (c) (i)   suggest why the heating in step 3 was carried out in a fume cupboard.   . .  [1]  (ii)  why was the dish reweighed in step 3?   . ...   . .  [2]  (d)  suggest two reasons why the amount of zinc oxide produced in step 3 was not the same  as the mass of zinc oxide used in step 1.  1  ... .  2  ... ...  [2] [total: 7]",
            "5": "5 0620/62/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use4  a student investigated the reaction of aqueous sodium hydroxide with two different acids, g  and h.   two experiments were carried out.  experiment 1   using a measuring cylinder, 20  cm3 of the solution of acid g was poured into a polystyrene  cup. the initial temperature of the solution was measured.   a burette was \ufb01 lled with aqueous sodium hydroxide to the 0.0  cm3 mark.   5.0  cm3 of aqueous sodium hydroxide was added to the solution of g in the cup and the  mixture stirred. the maximum temperature of the solution was measured.   a further 5.0  cm3 of aqueous sodium hydroxide was added to the cup and the mixture stirred.  the maximum temperature of the mixture was measured.   further 5.0  cm3 portions of aqueous sodium hydroxide were added to the cup, until a total  volume of 40.0  cm3 of sodium hydroxide had been added. after each addition, the mixture  was stirred and the maximum temperatures measured.",
            "6": "6 0620/62/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (a)  use the thermometer diagrams in the table to record the temperatures. 0.0 5.0 10.015.020.0thermometer diagramvolume of aqueous sodium hydroxide added  / cm3maximum temperature of solution in polystyrene cup  / \u00b0c 30 25 20 30 25 20 35 30 25 40 35 30 40 35 30 25.040 35 30 30.040 35 30 35.040 35 30 40.040 35 30 [3]",
            "7": "7 0620/62/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use experiment 2   experiment 1 was repeated using 20  cm3 of the solution of acid h instead of the solution of  acid g.  (b)  use the thermometer diagrams in the table to record the temperatures. 0.0 5.0 10.015.020.0thermometer diagramvolume of aqueous sodium hydroxide added  / cm3maximum temperature of solution in polystyrene cup  / \u00b0c 30 25 20 30 25 20 35 30 25 40 35 30 40 35 30 25.040 35 30 30.040 35 30 35.040 35 30 40.040 35 30 [3]",
            "8": "8 0620/62/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label your graphs. 40 35 30 25 20 0.0 5.0 10.0 15.0 20.0 volume of aqueous sodium hydroxide added  / cm3maximum temperature of solution  / \u00b0c 25.0 30.0 35.0 40.0 [6]  (d)  use your graph  to estimate the maximum temperature of the reaction mixture when 8.0  cm3 of aqueous sodium hydroxide was added to 20  cm3 of the solution of acid g.  show clearly on the graph  how you worked out your answer.   ... ..  [2]  (e)  what type of chemical reaction, other than neutralisation, occurs when acid h reacts with  aqueous sodium hydroxide?   ... ..  [1]",
            "9": "9 0620/62/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (f) (i)   in which experiment was the temperature change greater?   . .  [1]  (ii)  suggest why the temperature change was greater in this experiment.   . ...   . .  [1]  (g)  predict the temperature of the mixture in experiment 2 after two hours.   explain your answer.   ...    ... ..  [2] [total: 19]",
            "10": "10 0620/62/o/n/12 \u00a9 ucles 2012for examiner\u2019s use5  two salt solutions, j and k, were analysed. j was aqueous iron( ii) sulfate.   the tests on the solutions, and some of the observations, are in the table.   complete the observations in the table. tests observations tests on solution j (a)  appearance of solution j.  .  [1] (b)  to about 1  cm3 of solution j, an equal  volume of aqueous sodium hydroxide was added.  .  [2] (c)  to about 1  cm3 of solution j, an equal  volume of aqueous ammonia was added.  .  [1] (d)  to about 1  cm3 of solution j, dilute nitric  acid and aqueous silver nitrate were added.  .  [1] (e)  to about 1  cm3 of solution j, dilute nitric  acid and barium nitrate solution were added.  .  [2] tests on solution k (f)  appearance of solution k. dark pink liquid (g)  to about 1  cm3 of solution k, an equal  volume of aqueous sodium hydroxide was added.blue precipitate formed (h)  to solution k, aqueous sodium hydroxide  and aluminium powder were added. the mixture was heated.   the gas given off was tested.effervescence, pungent gas evolved damp red litmus turned blue",
            "11": "11 0620/62/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (i)  identify the gas given off in test (h).   ... ..  [1]  (j)  what conclusions can you draw about solution k?   ...    ... ..  [2] [total: 10]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/62/o/n/12 \u00a9 ucles 2012for examiner\u2019s use6 (a)  ethanoic acid can be prepared by heating ethanol with acidi \ufb01 ed potassium  manganate( vii).   give a test to distinguish between ethanoic acid and ethanol.  test     result  .. .  [2]  (b)  coal is a fossil fuel. when heated strongly, sulfur dioxide gas is one of the products  formed.   sulfur dioxide changes the colour of acidi \ufb01 ed potassium manganate( vii) from purple to  colourless.   plan an investigation to show which of the two different types of coal produces the most  sulfur dioxide when heated. you are provided with one lump of each type of coal.   ...    ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 8]"
        },
        "0620_w12_qp_63.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. at the end of the examination, fasten all your work securely together.the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical october/november 2012  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib12 11_0620_63/2rp\u00a9 ucles 2012 *1741889902* for examiner\u2019s use 1 23456 total",
            "2": "2 0620/63/o/n/12 \u00a9 ucles 2012for examiner\u2019s use1  the diagrams show four sets of apparatus, a, b, c and d. aliquidthermometer bcdliquidthermometer liquidthermometer liquidthermometer side arm side arm  (a) (i)   which set of apparatus would be most suitable to determine the boiling point of a  liquid?  .. [1]  (ii)  indicate with an arrow on this diagram where heat should be applied. [1]  (b)  what would be the effect if the liquid in a was heated strongly? explain your answer.  effect  .. ...  explanation  .   [2]  (c)  the apparatus below can be used to prepare and collect a gas which is insoluble in  water. complete the diagram to show how this gas could be collected over water. label the diagram. [2] [total: 6]",
            "3": "3 0620/63/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use2  a student carried out two experiments to investigate the speed of reaction between magnesium  and excess dilute sulfuric acid.    the apparatus shown below was used to measure the volume of gas produced. dilute sulfuric acidgas syringe magnesium ribbon  (a)  name the gas produced during the reaction.   ... ..  [1]  two experiments were carried out.  experiment 1   dilute sulfuric acid was added to magnesium ribbon and the volume of gas produced was  measured every minute for seven minutes.",
            "4": "4 0620/63/o/n/12 \u00a9 ucles 2012for examiner\u2019s use (b)  use the gas syringe diagrams to complete the table of results. time  / min gas syringe diagram volume of gas produced  / cm3 01 02 03 0 50 60 400 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 401 2 3 45 6 01 02 03 0 50 60 407 [3]  experiment 2   the results for experiment 2 have been plotted on the grid opposite and a graph drawn.  (c)  plot the results for experiment 1 on the grid. draw a smooth line graph. [4]",
            "5": "5 0620/63/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use70 605040302010 0 0123 time  / min4567volume of gas  / cm3experiment 2  (d) (i)   at which time interval does the volume reading appear to be inaccurate? explain the reason for your choice.   . ...   . .  [2]  (ii)  what was the total volume of gas that should have been produced at that time? indicate on the grid  how you arrived at your answer.  .. [2]  (e)  suggest and explain how the conditions had changed in experiment 2 compared to  experiment 1.   ...    ... ..  [2] [total: 14]",
            "6": "6 0620/63/o/n/12 \u00a9 ucles 2012for examiner\u2019s use3  the formula of any acid can be written as h ya.   a student investigated an acid, s, by titrating its aqueous solution with aqueous sodium  hydroxide.   a burette was \ufb01 lled with a solution of acid s up to the 0.0  cm3 mark. a 25.0  cm3 portion of  aqueous sodium hydroxide was added to a conical \ufb02 ask. a few drops of litmus indicator  were added to the \ufb02 ask. the acid was added from the burette until the colour of the indicator  changed. three titrations were carried out.   the burette diagrams in the table below show the initial and \ufb01 nal readings in the three  titrations.  (a)  use the burette diagrams to record the volumes in the table. complete the table. 1 2 3burette diagramburette diagramtitrationinitial reading /  cm3final reading / cm3difference / cm3 0 12 161718 8910232425 404142 313233 [3]  (b)  which of these are the best two titration results? use these results to work out the  average volume of solution s added.  best results   ...  average volume = .cm3 [2]",
            "7": "7 0620/63/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (c)  which piece of apparatus was used to measure the sodium hydroxide solution?   ... ..  [1]  (d)  the litmus indicator changed colour  from  ...  to  ... [1]   the experiment was repeated using hydrochloric acid of the same concentration as acid s.  46.6  cm3 of hydrochloric acid was needed to neutralise 25.0  cm3 of the aqueous sodium  hydroxide.  (e) (i)  compare the volume of acid s used to neutralise 25.0  cm3 of the aqueous sodium  hydroxide with the volume of hydrochloric acid used.   . .  [1]  (ii)  suggest the value of y in the formula h ya for acid s.   . .  [1] [total: 9]",
            "8": "8 0620/63/o/n/12 \u00a9 ucles 2012for examiner\u2019s use4  a mixture of solids, y and z, was analysed. y was calcium chloride, which is water-soluble  and z is an insoluble salt.   the tests on the mixture, and some of the observations, are in the following table.   complete the observations in the table. tests observations distilled water was added to the mixture in  a boiling tube. the mixture was shaken and \ufb01 ltered. the residue was saved and tests  carried out on the \ufb01 ltrate. tests on the \ufb01 ltrate (a)  the solution was divided into threetest-tubes and the following tests were carried out.  (i)   to the \ufb01 rst test-tube of solution, drops  of aqueous sodium hydroxide were added.    excess aqueous sodium hydroxide was then added to the test-tube.  (ii)   test (i) was repeated using aqueous  ammonia instead of aqueous sodium hydroxide.  (iii)   to the third test-tube of the solution, dilute nitric acid was added followed by silver nitrate solution.. ... [3] ... [1]... [2] tests on the residue (b)  dilute nitric acid was added to the residue.   the gas given off was tested with  limewater.   distilled water was added to the solution followed by aqueous potassium iodide.rapid effervescence limewater turned milky yellow precipitate formed  (c)  identify the gas given off in test (b).   ... ..  [1]  (d)  what conclusions can you draw about solid z?   ... ..  [2] [total: 9]",
            "9": "9 0620/63/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use5  a student investigated the temperature changes when zinc and magnesium react with  aqueous iron( ii) sulfate solution.   two experiments were carried out.  experiment 1   using a measuring cylinder, 40  cm3 of aqueous iron( ii) sulfate was poured into a beaker and  the initial temperature of the solution was measured. the initial temperature of the solution was 25  \u00b0c in each experiment.   0.2  g of zinc powder was added to the beaker and the maximum temperature of the mixture  measured and recorded.   the experiment was repeated using increasing masses of zinc powder. the results are in the  table below. mass of zinc added  / gmaximum temperature  / \u00b0ctemperature rise  / \u00b0c 0.0 25.0 0.0 0.2 30.0 5.00.4 34.5 9.50.6 39.0 14.00.8 44.0 19.01.0 44.0 19.01.2 44.0 19.0",
            "10": "10 0620/63/o/n/12 \u00a9 ucles 2012for examiner\u2019s use experiment 2   experiment 1 was repeated using magnesium powder.  (a)  use the thermometer diagrams in the table to record the maximum temperatures reached  and complete the table. 0.0 0.20.40.60.8thermometer diagrammass of magnesium added  / gmaximum temperature reached  / \u00b0ctemperature rise  / \u00b0c 30 25 20 35 30 25 40 35 30 45 40 35 50 45 40 50 45 40 50 45 401.0 1.2 [3]",
            "11": "11 0620/63/o/n/12 \u00a9 ucles 2012 [turn overfor examiner\u2019s use (b)  plot the results for both experiments on the grid below. for each experiment draw a  graph with two intersecting straight lines. label the graphs. 0.0 0.2 0.4 0.6 mass of metal added  / g0.8 1.0 1.225 201510 5 0temperature rise  / \u00b0c [5]  (c)  use your graphs  to \ufb01 nd  (i)  the mass of zinc required to produce a temperature rise of 12  \u00b0c.   . .  [1]  (ii)  the temperature rise produced by 0.3  g of magnesium.   . .  [1]  (d)  what is the minimum mass of magnesium required to produce the maximum temperature?   ... ..  [1]  (e)  which reagent is in excess in experiment 1? explain your answer.   ...    ... ..  [2]  (f)  experiment 2 was repeated using copper powder. suggest how the results of this  experiment would compare with those using zinc and magnesium.   ...    ... ..  [2] [total: 15]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/63/o/n/12 \u00a9 ucles 2012for examiner\u2019s use6 fats and oils   unsaturated fats and oils contain at least one carbon to carbon double bond.   these double bonds react with bromine water which changes colour from orange to colourless.    plan an experiment that could be carried out to compare samples of sun \ufb02 ower oil, olive oil  and butter to \ufb01 nd out which of these contains the largest number of carbon to carbon double  bonds.   you are provided with common laboratory apparatus and an organic solvent to dissolve the  fats and oils.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [7] [total: 7]"
        }
    },
    "2013": {
        "0620_s13_qp_11.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib13 06_0620_11/rp  \u00a9 ucles 2013  [turn over       *9639789716* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  may/june 2013       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2013 0620/11/m/j/13  1 the diagram shows a cup of tea.        which row describes the water particles in the air above the cup compared with the water  particles in the cup?     moving faster closer together  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     2 crystals of sodium chloride were prepared by the following method.    1 25.0  cm3 of dilute hydrochloric acid was accurately measured into a conical flask.  2 aqueous sodium hydroxide was added until the solution was neutral. the volume of  sodium hydroxide added was measured.  3 the solution was evaporated and the crystals washed with approximately 15  cm3 of  water.    which row shows the pieces of apparatus used to measure the 25.0  cm3 of hydrochloric acid, the  volume of aqueous sodium hydroxide and the 15  cm3 of water?     25.0  cm3 of hydrochloric  acid accurately the volume of aqueous  sodium hydroxide added 15  cm3 of water  approximately  a burette pipette measuring cylinder  b measuring cylinder burette pipette  c pipette burette measuring cylinder  d pipette measuring cylinder burette     ",
            "3": "3  \u00a9 ucles 2013 0620/11/m/j/13 [turn over  3 lead iodide is insoluble in water.    lead iodide is made by adding aqueous lead nitrate to aqueous potassium iodide.    which pieces of apparatus are needed to obtain solid lead iodide from 20  cm3 of aqueous lead  nitrate?    12345    a 1, 2 and 4 b 1, 3 and 5 c 1, 4 and 5 d 2, 4 and 5      4 element x is represented by x27 13.    which statement about element x is correct?  a an atom of x contains 13 protons and 13 neutrons.  b an atom of x contains 27 protons and 13 electrons.  c x forms an ion by gaining electrons.  d x is placed in group iii of the periodic table.      5 the positions of four elements are shown on the outline of the periodic table.    which element forms a coloured oxide?    a b c d      ",
            "4": "4  \u00a9 ucles 2013 0620/11/m/j/13  6 for which substance is the type of bonding not correct?    type of bonding   substance  ionic covalent metallic  a chlorine  \u0013   b potassium bromide \u0013    c sodium   \u0013  d sodium chloride  \u0013       7 element x has six electrons in its outer shell.    = electronkey e eee eee     how could the element react?  a by gaining two electrons to form a positive ion  b by losing six electrons to form a negative ion  c by sharing two electrons with two electrons from another element to form two covalent bonds  d by sharing two electrons with two electrons from another element to form four covalent bonds     8 the diagram shows an incomplete circuit.    glass tubelamp     which substance causes the lamp to  light when added to the glass tube?  a aqueous sodium chloride  b aqueous sugar  c solid sodium chloride  d solid sugar     ",
            "5": "5  \u00a9 ucles 2013 0620/11/m/j/13 [turn over  9 a compound with the formula xf 2 has a relative formula mass of 78.    what is element x?  a argon  b calcium  c neon  d zirconium     10 what is the balanced chemical equation for the reaction between calcium and water?  a ca  +  h 2o \u2192 caoh + h 2  b ca  +  h 2o \u2192 ca(oh) 2 + h 2  c ca  +  2h 2o \u2192 caoh + h 2  d ca  +  2h 2o \u2192 ca(oh) 2 + h 2    11 the diagram shows an electrical cable.    metal coreplastic coating     which statement about the substances used is correct?  a the coating is plastic because it conducts electricity well.  b the core is copper because it conducts electricity well.  c the core is copper because it is cheap and strong.  d the core is iron because it is cheap and strong.     ",
            "6": "6  \u00a9 ucles 2013 0620/11/m/j/13  12 the diagram shows an electrolysis circuit.    at which electrode is hydrogen formed?    +\u2013 +\u2013 ab cd aqueous sodium chloridemolten sodiumchloride       13 some white anhydrous copper( ii) sulfate powder is put into a beaker of water and stirred.    what would show that the process was exothermic?  a a blue solution is formed.  b the beaker feels cooler.  c the beaker feels warmer.  d the powder dissolves in the water.      14 which substance does not require oxygen in order to produce energy?  a coal  b hydrogen  c natural gas  d 235u     ",
            "7": "7  \u00a9 ucles 2013 0620/11/m/j/13 [turn over  15 the equation shows the formation of anhydrous copper( ii) sulfate from hydrated copper( ii)  sulfate.    cuso 4.5h 2o    cuso 4  +  5h 2o    statements 1, 2 and 3 refer to this reaction.    1 hydrated copper( ii) sulfate is reduced to anhydrous copper( ii) sulfate.  2 the ( ii) in the name copper( ii) sulfate refers to the oxidation state of the metal.  3 the reaction is reversible.    which statements are correct?  a 1 only b 1 and 2 c 2 and 3 d 3 only      16 calcium carbonate reacts with hydrochloric acid to form carbon dioxide.    which changes would slow this reaction down?    1 decreasing the concentration of hydrochloric acid  2 decreasing the particle size of calcium carbonate  3 decreasing the temperature    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     17 the equations represent redox reactions.    in which equation is the underlined substance acting as a reducing agent?  a 3co   +  fe 2o3  \u2192  2fe  +  3co 2  b co 2  +  c  \u2192  2co  c cuo  +  h 2  \u2192  cu  +  h 2o  d cao  +  h 2o  \u2192  ca(oh) 2      18 ant stings hurt because of the methanoic acid produced by the ant.    which substance could, most safely , be used to neutralise the acid?     substance ph  a baking soda 8  b car battery acid 1  c lemon juice 3  d oven cleaner 14     ",
            "8": "8  \u00a9 ucles 2013 0620/11/m/j/13  19 the diagram shows one period of the periodic table.    li be b c n o f ne    which two elements form acidic oxides?  a carbon and lithium  b carbon and neon  c carbon and nitrogen  d nitrogen and neon     20 the diagram shows an experiment.    red litmus paperblue litmus paper aqueous ammonium chloride + aqueous sodium hydroxide heat    what happens to the pieces of litmus paper?     blue litmus paper red litmus paper  a changes colour changes colour  b changes colour no colour change  c no colour change changes colour  d no colour change no colour change     ",
            "9": "9  \u00a9 ucles 2013 0620/11/m/j/13 [turn over  21 two indicators, bromophenol blue and congo red, show the following colours in acidic solutions  and in alkaline solutions.    indicator acid alkali  bromophenol blue yellow blue  congo red violet red    a few drops of each indicator are added to separate samples of a solution of ph 2.    what are the colours of the indicators in this solution?    in a solution of ph 2    bromophenol blue is congo red is  a blue red  b blue violet  c yellow red  d yellow violet     22 which property of elements increases across a period of the periodic table?  a metallic character  b number of electron shells  c number of outer shell electrons  d tendency to form positive ions    23 which element is a transition metal?     colour of  chloride melting point of  element  / \u00b0c  a white 113  b white 1495  c yellow 113  d yellow 1495    ",
            "10": "10  \u00a9 ucles 2013 0620/11/m/j/13  24 fluorine is at the top of group vii in the periodic table.    which row shows the properties of fluorine?     colour state at room  temperature reaction with aqueous  potassium iodide  a brown gas no reaction  b brown liquid iodine displaced  c yellow gas iodine displaced  d yellow liquid no reaction      25 group i metals are also known as the alkali metals.    which statement about the metals in group i is not correct?  a in their reactions they lose electrons.  b their atoms all have one electron in their outer shell.  c they form +1 ions in their reactions with non-metals.  d they form covalent compounds by sharing electrons.     26 which element is a metal?     charge on  element ion electrical  conductivity  a negative low  b positive high  c negative high  d positive low      27 which property makes aluminium ideal for making food containers?  a conducts electricity  b conducts heat  c mechanical strength  d resistance to corrosion     ",
            "11": "11  \u00a9 ucles 2013 0620/11/m/j/13 [turn over  28 which substance is not involved in the extraction of iron from hematite?  a carbon  b carbon monoxide  c calcium carbonate  d nitrogen      29 pure metals conduct electricity and can be hammered into different shapes.    why are metals sometimes used as alloys?  a alloys are cheaper than the metals they are made from.  b alloys are easier to hammer into different shapes.  c alloys are harder and keep their shape better.  d alloys conduct electricity better.     30 below are some metals in decreasing order of reactivity.    magnesium  zinc  iron  copper    titanium reacts with acid and cannot be extracted from its ore by heating with carbon.    where should titanium be placed in this list?  a below copper  b between iron and copper  c between magnesium and zinc  d between zinc and iron     31 water has been contaminated with sea-water.    which substances can be removed by chlorination and filtration?  a bacteria, sand and sodium chloride  b bacteria and sand only  c bacteria and sodium chloride only  d sand and sodium chloride only     ",
            "12": "12  \u00a9 ucles 2013 0620/11/m/j/13  32 iron rusts when it reacts with \u2026\u20261\u2026\u2026    rusting can be prevented by covering the iron with a more reactive metal, such as \u2026\u20262\u2026\u2026    which words correctly complete gaps 1 and 2?     1 2  a oxygen copper  b oxygen magnesium  c oxygen and water copper  d oxygen and water magnesium      33 nitrogen, phosphorus and potassium are essential elements for plant growth.    which mixture provides all three essential elements?     mixture formula  a ammonium phosphate  +  potassium chloride (nh 4)3po 4  +  kc l  b ammonium phosphate  +  ammonium nitrate (nh 4)3po 4  +  nh 4no 3  c ammonium phosphate  +  ammonium chloride (nh 4)3po 4  +  nh 4cl  d ammonium nitrate  +  potassium chloride nh 4no 3  +  kc l    34 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0013 \u0017 key  b greenhouse gas \u0013 \u0013 \u0013 = true  c present in unpolluted air \u0017 \u0017 \u0017 = false  d produced during respiration \u0017 \u0013     ",
            "13": "13  \u00a9 ucles 2013 0620/11/m/j/13 [turn over  35 the list shows four methods that were suggested for the formation of carbon dioxide.    1 action of an alkali on a carbonate  2 action of heat on a carbonate  3 complete combustion of methane  4 reaction of a carbonate with oxygen    which methods would result in the production of carbon dioxide?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4      36 organic compounds may have names ending in -ane, -ene, -ol or -oic acid.    how many of these endings indicate the com pounds contain double bonds in their molecules?  a 1 b 2 c 3 d 4     37 the table shows the boiling points of four members of the homologous series of alcohols.    compound  name formula boiling point  / \u00b0c  methanol ch 3oh 65  ethanol c 2h5oh 78  propanol c 3h7oh x  butanol c 4h9oh 117    what is the value of x?  a 55  \u00b0c b 82  \u00b0c c 98  \u00b0c d 115  \u00b0c    ",
            "14": "14  \u00a9 ucles 2013 0620/11/m/j/13  38 the table shows some fractions that are obtained from petroleum by fractional distillation,  together with some of their uses.    fraction use  refinery gas cooking  gasoline fuel for cars  1 making chemicals  2 jet fuel  3 fuel for ships  bitumen making roads    which row correctly identifies fractions 1, 2 and 3?     1 2 3  a diesel oil fuel oil lubricating fraction  b fuel oil diesel oil kerosene  c kerosene naphtha diesel oil  d naphtha kerosene fuel oil     39 which columns describe the hydrocarbons ethane and ethene?     1 2 3 4  state at room temperature gas gas liquid liquid  reaction with oxygen burns burns burns burns  reaction with aqueous  bromine no reaction decolourises  bromine no reaction decolourises  bromine    a 1 (ethane) and 2 (ethene)  b 1 (ethane) and 4 (ethene)  c 2 (ethene) and 3 (ethane)  d 3 (ethane) and 4 (ethene)      40 which of the statements about ethanol are correct?    1 ethanol can be formed by an addition reaction.  2 ethanol can be formed by fermentation.  3 when ethanol burns in air, it forms carbon dioxide and water.    a 1, 2 and 3 b 1 and 2 c 1 and 3 d 2 and 3   ",
            "15": "15  \u00a9 ucles 2013 0620/11/m/j/13  blank page       ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of t he cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2013 0620/11/m/j/13   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s13_qp_12.pdf": {
            "1": "    this document consists of 16 printed pages.  ib13 06_0620_12/3rp  \u00a9 ucles 2013  [turn over       *5414314673* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  may/june 2013       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2013 0620/12/m/j/13  1 the diagram shows a cup of tea.        which row describes the water particles in the air above the cup compared with the water  particles in the cup?     moving faster closer together  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     2 the diagram shows an experiment to find the formula of magnesium oxide.    heatcrucible magnesium ribbon     which piece of apparatus would be needed in addition to those shown?  a a balance  b a measuring cylinder  c a spatula  d a thermometer     ",
            "3": "3  \u00a9 ucles 2013 0620/12/m/j/13 [turn over  3 methanol, ch 3oh, and ethanol, c 2h5oh, are miscible liquids.    which diagram shows apparatus that is used to obtain methanol from a mixture of ethanol and  methanol?    a b  c d  heat heat  heat     4 the positions of four elements are shown on the outline of the periodic table.    which element forms a coloured oxide?    a b c d     ",
            "4": "4  \u00a9 ucles 2013 0620/12/m/j/13  5 the diagram shows an atom of an element.    e e ee eekey = electron = nucleus containing    eleven particles     how many protons and neutrons are in the nucleus of the atom and in which group and period of  the periodic table is the element found?     number of  protons number of  neutrons group  number period  number  a 5 6 3 2  b 5 11 2 3  c 6 5 3 2  d 6 11 2 3     6 electrons from each element are shared by both of the elements in a compound.    which compound matches this description?  a lead bromide  b sodium chloride  c water  d zinc oxide      7 the equation shows the reaction between magnesium and sulfuric acid.    mg  +  h 2so 4  \u2192  mgso 4  +  h 2    (mg = 24, h = 1, s = 32, o = 16)    in this reaction, what mass of magnesium sulfate will be formed when 6  g of magnesium reacts  with excess sulfuric acid?  a 8 b 24 c 30 d 60     ",
            "5": "5  \u00a9 ucles 2013 0620/12/m/j/13 [turn over  8 element x has six electrons in its outer shell.    = electronkey e eee eee     how could the element react?  a by gaining two electrons to form a positive ion  b by losing six electrons to form a negative ion  c by sharing two electrons with two electrons from another element to form two covalent bonds  d by sharing two electrons with two electrons from another element to form four covalent bonds      9 the diagram shows an incomplete circuit.    glass tubelamp     which substance causes the lamp to  light when added to the glass tube?  a aqueous sodium chloride  b aqueous sugar  c solid sodium chloride  d solid sugar    10 what is the balanced chemical equation for the reaction between calcium and water?  a ca  +  h 2o \u2192 caoh + h 2  b ca  +  h 2o \u2192 ca(oh) 2 + h 2  c ca  +  2h 2o \u2192 caoh + h 2  d ca  +  2h 2o \u2192 ca(oh) 2 + h 2    ",
            "6": "6  \u00a9 ucles 2013 0620/12/m/j/13  11 the diagram shows an electrical cable.    metal coreplastic coating     which statement about the substances used is correct?  a the coating is plastic because it conducts electricity well.  b the core is copper because it conducts electricity well.  c the core is copper because it is cheap and strong.  d the core is iron because it is cheap and strong.     12 statement 1 hydrogen is used as a fuel.    statement 2 when hydrogen burns in the air to form water, heat energy is produced.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     13 which substance does not require oxygen in order to produce energy?  a coal  b hydrogen  c natural gas  d  235u     14 in which equation is the underlined substance acting as a reducing agent?    a 3co   +  fe 2o3  \u2192  2fe  +  3co 2  b co 2  +  c  \u2192  2co  c cuo  +  h 2  \u2192  cu  +  h 2o  d cao  +  h 2o  \u2192  ca(oh) 2     ",
            "7": "7  \u00a9 ucles 2013 0620/12/m/j/13 [turn over  15 the diagram shows an experiment to compare the rate of reaction when a metal is added to  hydrochloric acid.    in which test-tube is the reaction fastest?   concentrated  hydrochloric aciddilute  hydrochloric acidabcd zinc copper zinc copper    16 two oxides, x and y, are added separately to dilute sulfuric acid and dilute sodium hydroxide.    x reacts with dilute sulfuric acid but y does not react.    y reacts with aqueous sodium hydroxide but x does not react.    which type of oxide are x and y?     acidic oxide basic oxide metallic oxide  a x y x  b x y y  c y x x  d y x y     17 heating pink cobalt( ii) chloride crystals forms a blue solid and steam.    the blue solid turns pink when water is added.    which terms describe the pink cobalt( ii) chloride and the reaction?     pink cobalt( ii)  chloride is the reaction is  reversible  a anhydrous yes  b anhydrous no  c hydrated yes  d hydrated no     ",
            "8": "8  \u00a9 ucles 2013 0620/12/m/j/13  18 concentrated aqueous sodium chloride, concentrated hydrochloric acid and molten lead bromide  were separately electrolysed in experiments 1, 2 and 3.    platinum electrodesconcentrated aqueous sodium chlorideexperiment 1 experiment 3platinumelectrodesconcentrated hydrochloric acidexperiment 2 d.c. power supply lamp lead bromide toxic heat    which statement about the electrode products is correct?  a gases were given off at the anode in experiments 2 and 3 only.  b gases were given off at the cathode in experiments 1 and 2 only.  c metals were formed at the anode in experiments 1 and 3 only.  d metals were formed at the cathode in experiments 1 and 3 only.     19 which statement about the reaction of acids is correct?  a they react with ammonium salts to form a salt and ammonia only.  b they react with metal carbonates to give a salt and carbon dioxide only.  c they react with metal hydroxides to give a salt and water only.  d they react with metals to give a salt, hydrogen and water only. ",
            "9": "9  \u00a9 ucles 2013 0620/12/m/j/13 [turn over  20 the diagram shows an experiment.    red litmus paperblue litmus paper aqueous ammonium chloride + aqueous sodium hydroxide heat    what happens to the pieces of litmus paper?     blue litmus paper red litmus paper  a changes colour changes colour  b changes colour no colour change  c no colour change changes colour  d no colour change no colour change      21 two indicators, bromophenol blue and congo red, show the following colours in acidic solutions  and in alkaline solutions.    indicator acid alkali  bromophenol blue yellow blue  congo red violet red    a few drops of each indicator are added to separate samples of a solution of ph 2.    what are the colours of the indicators in this solution?    in a solution of ph 2    bromophenol blue is congo red is  a blue red  b blue violet  c yellow red  d yellow violet     ",
            "10": "10  \u00a9 ucles 2013 0620/12/m/j/13  22 w, x, y and z are elements in the same period in the periodic table.    w and y are metals. x and z are non-metals.    which shows the correct order of these elements across the period?  a w  x  y  z     b x z    w  y    c y     w x z    d w  y    x z      23 platinum is a transition metal.    which statement about platinum is correct?  a it does not catalyse reactions.  b it forms coloured compounds.  c it has a low density.  d it has a low melting point.     24 which element will be less reactive than the other members of its group in the periodic table?  a astatine  b caesium  c fluorine  d rubidium     25 bromine is in group vii on the periodic table.    which describes the appearance of bromine at room temperature?  a grey solid  b purple fumes  c red-brown liquid  d yellow gas     ",
            "11": "11  \u00a9 ucles 2013 0620/12/m/j/13 [turn over  26 a substance, x, has the following properties.    1 it has a high melting point.  2 it conducts electricity in the solid and liquid states.  3 it is malleable.  4 it had a high density.    what is x?  a a ceramic  b copper  c graphite  d sodium chloride      27 why is aluminium used to make food containers?  a it has a low density.  b it is strong.  c it keeps the food hot.  d it resists corrosion.      28 which statement is incorrect?  a carbon dioxide is a waste product in the extraction of iron.  b carbon monoxide is a reducing agent.  c the extraction of iron from hematite involves reduction.  d when iron is converted into steel, oxygen is used to oxidise the iron.    29 the diagram represents the structure of substance s.        what is s?  a an alloy  b an ionic solid  c a macromolecule  d a pure metal   ",
            "12": "12  \u00a9 ucles 2013 0620/12/m/j/13  30 q, r, s and t are four metals.    q is found naturally as the metal.  r reacts with steam but not with cold water.  s reacts violently with cold water.  the oxide of t is reduced to t by heating with carbon.    what is the order of reactivity of the four metals, starting with the most reactive first?  a q \u2192 r \u2192 t \u2192 s  b q \u2192 t \u2192 r \u2192 s  c s \u2192 r \u2192 q \u2192 t  d s \u2192 r \u2192 t \u2192 q      31 the diagram shows a stage in the purification of dirty water.    coarse gravelfine gravelsanddirty water pot with holes in bottom     which process does this apparatus show?  a chlorination  b condensation  c distillation  d filtration     ",
            "13": "13  \u00a9 ucles 2013 0620/12/m/j/13 [turn over  32 the diagrams show two processes.    iron  irontorch rust before after  rusting  welding     for which processes is oxygen involved?     rusting welding  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      33 which substance would make the best general fertiliser?    relative amount    p k n solubility in water  a 5 0 5 soluble  b 5 5 20 insoluble  c 5 10 15 soluble  d 10 5 10 insoluble     34 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0013 \u0017 key  b greenhouse gas \u0013 \u0013 \u0013 = true  c present in unpolluted air \u0017 \u0017 \u0017 = false  d produced during respiration \u0017 \u0013     ",
            "14": "14  \u00a9 ucles 2013 0620/12/m/j/13  35 which process does not produce carbon dioxide?  a fermentation  b respiration  c the production of lime from limestone  d the treatment of acidic soil with lime      36 organic compounds may have names ending in -ane, -ene, -ol or -oic acid.    how many of these endings indicate the com pounds contain double bonds in their molecules?  a 1 b 2 c 3 d 4     37 in the flow chart, which fuel could be gasoline?    is it obtained from petroleum? is it used as fuel for cars?is it used as fuel for cars?no yes no yes ab cdno yes     38 the structures of four molecules are shown.    s rc hh oh h pqcoh ch o hhcoh ho c hhc hh     which two molecules belong to the same homologous series?  a p and q b p and s c q and r d r and s     ",
            "15": "15  \u00a9 ucles 2013 0620/12/m/j/13  39 which columns describe the hydrocarbons ethane and ethene?     1 2 3 4  state at room temperature gas gas liquid liquid  reaction with oxygen burns burns burns burns  reaction with aqueous  bromine no reaction decolourises  bromine no reaction decolourises  bromine    a 1 (ethane) and 2 (ethene)  b 1 (ethane) and 4 (ethene)  c 2 (ethene) and 3 (ethane)  d 3 (ethane) and 4 (ethene)      40 which process is not used during the production of ethanol?  a addition of steam to ethene  b fermentation  c fractional distillation  d reacting ethane with oxygen    ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2013 0620/12/m/j/13   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s13_qp_13.pdf": {
            "1": "    this document consists of 15 printed pages and 1 blank page.  ib13 06_0620_13/fp  \u00a9 ucles 2013  [turn over       *3600035500* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  may/june 2013       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2013 0620/13/m/j/13  1 the diagram shows a cup of tea.        which row describes the water particles in the air above the cup compared with the water  particles in the cup?     moving faster closer together  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    2 crystals of sodium chloride were prepared by the following method.    1 25.0  cm3 of dilute hydrochloric acid was accurately measured into a conical flask.  2 aqueous sodium hydroxide was added until the solution was neutral. the volume of  sodium hydroxide added was measured.  3 the solution was evaporated and the crystals washed with approximately 15  cm3 of  water.    which row shows the pieces of apparatus used to measure the 25.0  cm3 of hydrochloric acid, the  volume of aqueous sodium hydroxide and the 15  cm3 of water?     25.0  cm3 of hydrochloric  acid accurately the volume of aqueous  sodium hydroxide added 15  cm3 of water  approximately  a burette pipette measuring cylinder  b measuring cylinder burette pipette  c pipette burette measuring cylinder  d pipette measuring cylinder burette     ",
            "3": "3  \u00a9 ucles 2013 0620/13/m/j/13 [turn over  3 the positions of four elements are shown on the outline of the periodic table.    which element forms a coloured oxide?    a b c d      4 lead iodide is insoluble in water.    lead iodide is made by adding aqueous lead nitrate to aqueous potassium iodide.    which pieces of apparatus are needed to obtain solid lead iodide from 20  cm3 of aqueous lead  nitrate?    12345    a 1, 2 and 4 b 1, 3 and 5 c 1, 4 and 5 d 2, 4 and 5     5 element x is represented by  x27 13.    which statement about element x is correct?  a an atom of x contains 13 protons and 13 neutrons.  b an atom of x contains 27 protons and 13 electrons.  c x forms an ion by gaining electrons.  d x is placed in group iii of the periodic table.     ",
            "4": "4  \u00a9 ucles 2013 0620/13/m/j/13  6 element x has six electrons in its outer shell.    = electronkey e eee eee     how could the element react?  a by gaining two electrons to form a positive ion  b by losing six electrons to form a negative ion  c by sharing two electrons with two electrons from another element to form two covalent bonds  d by sharing two electrons with two electrons from another element to form four covalent bonds      7 for which substance is the type of bonding not correct?    type of bonding   substance  ionic covalent metallic  a chlorine  \u0013   b potassium bromide \u0013    c sodium   \u0013  d sodium chloride  \u0013     8 a compound with the formula xf 2 has a relative formula mass of 78.    what is element x?  a argon  b calcium  c neon  d zirconium     ",
            "5": "5  \u00a9 ucles 2013 0620/13/m/j/13 [turn over  9 the diagram shows an incomplete circuit.    glass tubelamp     which substance causes the lamp to  light when added to the glass tube?  a aqueous sodium chloride  b aqueous sugar  c solid sodium chloride  d solid sugar     10 the diagram shows an electrical cable.    metal coreplastic coating     which statement about the substances used is correct?  a the coating is plastic because it conducts electricity well.  b the core is copper because it conducts electricity well.  c the core is copper because it is cheap and strong.  d the core is iron because it is cheap and strong.     11 what is the balanced chemical equation for the reaction between calcium and water?  a ca  +  h 2o \u2192 caoh + h 2  b ca  +  h 2o \u2192 ca(oh) 2 + h 2  c ca  +  2h 2o \u2192 caoh + h 2  d ca  +  2h 2o \u2192 ca(oh) 2 + h 2     ",
            "6": "6  \u00a9 ucles 2013 0620/13/m/j/13  12 some white anhydrous copper( ii) sulfate powder is put into a beaker of water and stirred.    what would show that the process was exothermic?  a a blue solution is formed.  b the beaker feels cooler.  c the beaker feels warmer.  d the powder dissolves in the water.      13 the diagram shows an electrolysis circuit.    at which electrode is hydrogen formed?    +\u2013 +\u2013 ab cd aqueous sodium chloridemolten sodiumchloride       14 which substance does not require oxygen in order to produce energy?  a coal  b hydrogen  c natural gas  d 235u      15 calcium carbonate reacts with hydrochloric acid to form carbon dioxide.    which changes would slow this reaction down?    1 decreasing the concentration of hydrochloric acid  2 decreasing the particle size of calcium carbonate 3 decreasing the temperature    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     ",
            "7": "7  \u00a9 ucles 2013 0620/13/m/j/13 [turn over  16 the equation shows the formation of anhydrous copper( ii) sulfate from hydrated copper( ii)  sulfate.    cuso 4.5h 2o    cuso 4  +  5h 2o    statements 1, 2 and 3 refer to this reaction.    1 hydrated copper( ii) sulfate is reduced to anhydrous copper( ii) sulfate.  2 the ( ii) in the name copper( ii) sulfate refers to the oxidation state of the metal.  3 the reaction is reversible.    which statements are correct?  a 1 only b 1 and 2 c 2 and 3 d 3 only      17 ant stings hurt because of the methanoic acid produced by the ant.    which substance could, most safely , be used to neutralise the acid?     substance ph  a baking soda 8  b car battery acid 1  c lemon juice 3  d oven cleaner 14      18 in which equation is the underlined substance acting as a reducing agent?    a 3co  +  fe 2o3  \u2192  2fe  +  3co 2  b co 2  +  c  \u2192  2co  c cuo  +  h 2  \u2192  cu  +  h 2o  d cao  +  h 2o  \u2192  ca(oh) 2     ",
            "8": "8  \u00a9 ucles 2013 0620/13/m/j/13  19 two indicators, bromophenol blue and congo red, show the following colours in acidic solutions  and in alkaline solutions.    indicator acid alkali  bromophenol blue yellow blue  congo red violet red    a few drops of each indicator are added to separate samples of a solution of ph 2.    what are the colours of the indicators in this solution?    in a solution of ph 2    bromophenol blue is congo red is  a blue red  b blue violet  c yellow red  d yellow violet     20 the diagram shows an experiment.    red litmus paperblue litmus paper aqueous ammonium chloride + aqueous sodium hydroxide heat    what happens to the pieces of litmus paper?     blue litmus paper red litmus paper  a changes colour changes colour  b changes colour no colour change  c no colour change changes colour  d no colour change no colour change     ",
            "9": "9  \u00a9 ucles 2013 0620/13/m/j/13 [turn over  21 the diagram shows one period of the periodic table.    li be b c n o f ne    which two elements form acidic oxides?  a carbon and lithium  b carbon and neon  c carbon and nitrogen  d nitrogen and neon     22 which element is a transition metal?     colour of  chloride melting point of  element  / \u00b0c  a white 113  b white 1495  c yellow 113  d yellow 1495    23 which property of elements increases across a period of the periodic table?  a metallic character  b number of electron shells  c number of outer shell electrons  d tendency to form positive ions    24 which property makes aluminium ideal for making food containers?  a conducts electricity  b conducts heat  c mechanical strength  d resistance to corrosion    ",
            "10": "10  \u00a9 ucles 2013 0620/13/m/j/13  25 fluorine is at the top of group vii in the periodic table.    which row shows the properties of fluorine?     colour state at room  temperature reaction with aqueous  potassium iodide  a brown gas no reaction  b brown liquid iodine displaced  c yellow gas iodine displaced  d yellow liquid no reaction      26 which element is a metal?     charge on  element ion electrical  conductivity  a negative low  b positive high  c negative high  d positive low     27 group i metals are also known as the alkali metals.    which statement about the metals in group i is not correct?  a in their reactions they lose electrons.  b their atoms all have one electron in their outer shell.  c they form +1 ions in their reactions with non-metals.  d they form covalent compounds by sharing electrons.     ",
            "11": "11  \u00a9 ucles 2013 0620/13/m/j/13 [turn over  28 below are some metals in decreasing order of reactivity.    magnesium  zinc  iron  copper    titanium reacts with acid and cannot be extracted from its ore by heating with carbon.    where should titanium be placed in this list?  a below copper  b between iron and copper  c between magnesium and zinc  d between zinc and iron     29 which substance is not involved in the extraction of iron from hematite?  a carbon  b carbon monoxide  c calcium carbonate  d nitrogen    30 pure metals conduct electricity and can be hammered into different shapes.    why are metals sometimes used as alloys?  a alloys are cheaper than the metals they are made from.  b alloys are easier to hammer into different shapes.  c alloys are harder and keep their shape better.  d alloys conduct electricity better.     31 water has been contaminated with sea-water.    which substances can be removed by chlorination and filtration?  a bacteria, sand and sodium chloride  b bacteria and sand only  c bacteria and sodium chloride only  d sand and sodium chloride only     ",
            "12": "12  \u00a9 ucles 2013 0620/13/m/j/13  32 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0013 \u0017 key  b greenhouse gas \u0013 \u0013 \u0013 = true  c present in unpolluted air \u0017 \u0017 \u0017 = false  d produced during respiration \u0017 \u0013      33 iron rusts when it reacts with \u2026\u20261\u2026\u2026    rusting can be prevented by covering the iron with a more reactive metal, such as \u2026\u20262\u2026\u2026    which words correctly complete gaps 1 and 2?     1 2  a oxygen copper  b oxygen magnesium  c oxygen and water copper  d oxygen and water magnesium    34 nitrogen, phosphorus and potassium are essential elements for plant growth.    which mixture provides all three essential elements?     mixture formula  a ammonium phosphate  +  potassium chloride (nh 4)3po 4  +  kc l  b ammonium phosphate  +  ammonium nitrate (nh 4)3po 4  +  nh 4no 3  c ammonium phosphate  +  ammonium chloride (nh 4)3po 4  +  nh 4cl  d ammonium nitrate  +  potassium chloride nh 4no 3  +  kc l    ",
            "13": "13  \u00a9 ucles 2013 0620/13/m/j/13 [turn over  35 organic compounds may have names ending in -ane, -ene, -ol or -oic acid.    how many of these endings indicate the com pounds contain double bonds in their molecules?  a 1 b 2 c 3 d 4     36 the list shows four methods that were suggested for the formation of carbon dioxide.    1 action of an alkali on a carbonate  2 action of heat on a carbonate 3 complete combustion of methane  4 reaction of a carbonate with oxygen    which methods would result in the production of carbon dioxide?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     37 the table shows the boiling points of four members of the homologous series of alcohols.    compound  name formula boiling point  / \u00b0c  methanol ch 3oh 65  ethanol c 2h5oh 78  propanol c 3h7oh x  butanol c 4h9oh 117    what is the value of x?  a 55  \u00b0c b 82  \u00b0c c 98  \u00b0c d 115  \u00b0c    38 which columns describe the hydrocarbons ethane and ethene?     1 2 3 4  state at room temperature gas gas liquid liquid  reaction with oxygen burns burns burns burns  reaction with aqueous  bromine no reaction decolourises  bromine no reaction decolourises  bromine    a 1 (ethane) and 2 (ethene)  b 1 (ethane) and 4 (ethene)  c 2 (ethene) and 3 (ethane)  d 3 (ethane) and 4 (ethene) ",
            "14": "14  \u00a9 ucles 2013 0620/13/m/j/13  39 the table shows some fractions that are obtained from petroleum by fractional distillation,  together with some of their uses.    fraction use  refinery gas cooking  gasoline fuel for cars  1 making chemicals  2 jet fuel  3 fuel for ships  bitumen making roads    which row correctly identifies fractions 1, 2 and 3?     1 2 3  a diesel oil fuel oil lubricating fraction  b fuel oil diesel oil kerosene  c kerosene naphtha diesel oil  d naphtha kerosene fuel oil     40 which of the statements about ethanol are correct?    1 ethanol can be formed by an addition reaction.  2 ethanol can be formed by fermentation. 3 when ethanol burns in air, it forms carbon dioxide and water.    a 1, 2 and 3 b 1 and 2 c 1 and 3 d 2 and 3     ",
            "15": "15  \u00a9 ucles 2013 0620/13/m/j/13  blank page",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2013 0620/13/m/j/13   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s13_qp_21.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 may/june 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib13 06_0620_21/2rp\u00a9 ucles 2013 *0286058287*",
            "2": "2 0620/21/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  the electronic structures of \ufb01 ve atoms of different elements, a, b, c, d and e, are shown  below. a b c d e   answer the following questions about these structures. each structure may be used once,  more than once or not at all.  (a)  which structure  (i)  is in period 4 of the periodic table,  (ii)  is a noble gas,  (iii)  is in group ii of the periodic table,  (iv)  has \ufb01 ve electrons in its outer shell,  (v)  has a proton (atomic) number of 7,  (vi)  represents a \ufb02 uorine atom? [6]  (b)  complete the following sentences about elements using words from the list below. alkali       atom       covalent       ion monatomic       three       transition       two   an element is a substance containing only one type of .. .   the group vii elements exist as molecules containing .. atoms.   carbon has a giant .. structure with many strong bonds.   elements such as iron and copper, which form coloured compounds, are called  .. elements. [4] [total: 10]",
            "3": "3 0620/21/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  the table below shows some properties of the group i elements. metal density in g  / cm3melting point  / \u00b0c boiling point  / \u00b0c lithium 0.53 181 1342 sodium 0.97 98 883potassium 0.86 63rubidium 1.53 39 686caesium 1.88 29 669  (a)  use the information in the table to explain why caesium is a liquid when the temperature  is 34  \u00b0c.   ...    ... ..  [1]  (b)  suggest a value for the boiling point of potassium. .. \u00b0c  [1]  (c) (i)   describe the general  trend in density down the group.   . .  [1]  (ii)  which element does not follow this trend?   . .  [1]  (d)  state three  physical properties of potassium, other than density, melting point and boiling  point.   ...    ...    ... ..  [3]  (e)  potassium reacts with water. the products are potassium hydroxide and hydrogen.  (i)  describe two observations when potassium reacts with water.   . ...   . ...   . .  [2]  (ii)  complete the symbol equation for this reaction.  2k  +  ..h2o  \u2192  2koh  +  . [2] [total: 11]",
            "4": "4 0620/21/m/j/13 \u00a9 ucles 2013for examiner\u2019s use3 (a)   match the name of the homologous series on the left with its formula on the right.   the \ufb01 rst one has been done for you.  halogenoalkane alkanealkene alcohol carboxylic acidc 2h6 c2h4c2h5oh c2h5clch3cooh [4]  (b)  draw the full structural formula of the compound, c2h6, showing all atoms and bonds. [1]  (c)  the compound with the formula c2h4 is an unsaturated hydrocarbon.   describe the difference between a saturated and an unsaturated hydrocarbon in terms  of the bonds they contain.   ...    ... ..  [2]  (d)  describe a test to distinguish between a saturated and unsaturated hydrocarbon.  test     result with saturated hydrocarbon    ...   result with unsaturated hydrocarbon    ... ..  [3] [total: 10]",
            "5": "5 0620/21/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use4  farmers spread fertilisers on the soil where crops are to be grown.  (a)  why do farmers use fertilisers? in your answer, include  \u25cf  the names of the essential elements present in most fertilisers,  \u25cf  the reasons why farmers use fertilisers.   ...    ...    ...    ...    ... ..  [4]  (b)  urea can be used as a fertiliser.   the structure of urea is shown below. c onhh n hh  (i)  deduce the molecular formula of urea.   . .  [1]  (ii)  calculate the relative molecular mass of urea. you must show all your working. [2]",
            "6": "6 0620/21/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (c)  urea is a solid at room temperature. complete the diagram below to show the arrangement  of the molecules in solid urea.   show a molecule of urea as  [2]  (d)  when urea is heated with an alkali, ammonia is given off.   describe a test for ammonia.  test     result  .. .  [2] [total: 11]",
            "7": "7 0620/21/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use5  the table shows some properties of four substances, a, b, c and d. substance melting point  / \u00b0cdoes the solid  conduct electricity?does a solution of  the solid conduct  electricity? a 962 yes does not dissolve b 747 no dissolves and conducts c 113 no does not dissolve d 3550 no does not dissolve  (a)  which one of these substances has  (i)  a giant covalent structure,  (ii) a simple molecular structure,  (iii) a metallic structure? [3]  (b)  a student carried out an experiment to determine the rate of reaction of calcium carbonate  with excess hydrochloric acid. caco3(s)  +  2hc l (aq)  \u2192  cac l 2(aq)  +  co2(g)  +  h2o(l)   he recorded the loss of mass of the reaction mixture over a period of time. 362.05cotton wool small pieces of calcium carbonate balancehydrochloric acid  (i)  explain why the reaction mixture decreases in mass.   . .  [1]",
            "8": "8 0620/21/m/j/13 \u00a9 ucles 2013for examiner\u2019s use  he carried out the reaction at constant temperature using 2  g of calcium carbonate in  small pieces. the hydrochloric acid was in excess.   he plotted his results on a grid. this is shown below. 1.0 0.80.60.40.2 0 0 100 200 300 400 500 600 time  / secondsloss in mass  / g  (ii)  at what time has the reaction just \ufb01 nished? ... s  [1]  (iii)  from the graph, deduce the loss in mass in the \ufb01 rst 100 seconds. ... g  [1]  (iv)  the student repeated the experiment keeping everything the same except for the  size of the pieces of calcium carbonate. he used smaller pieces of calcium carbonate but the mass used was the same.   on the grid above, draw a line to show how the loss of mass changes with time when  smaller pieces of calcium carbonate are used. [2]  (v)   state the effect of increasing the concentration of hydrochloric acid on the rate  (speed) of this reaction when all other factors remain constant.   . .  [1] [total: 9]",
            "9": "9 0620/21/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use6 (a)  propanol is a solvent.   sugar is soluble in propanol. salt (sodium chloride) is insoluble in propanol.   a student wants to separate a mixture of solid salt and solid sugar.  (i)  describe how she could separate the salt from the sugar.   you may draw a labelled diagram to help you answer this question.   . ...   . ...   . .  [3]  (ii)  describe how the student could obtain solid sodium chloride from a solution of  sodium chloride in water.   . .  [1]  (b)  the diagram shows the structure of sodium chloride. na+ cl \u2013 na+ cl \u2013na+ na+cl \u2013cl \u2013na+ cl \u2013 na+ cl \u2013na+ na+cl \u2013cl \u2013  (i)  deduce the simplest formula for sodium chloride.   . .  [1]  (ii)  what type of bonding is present in sodium chloride?   put a ring around the correct answer.  covalent          ionic          metallic          weak  [1]",
            "10": "10 0620/21/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (c)  the diagram shows the apparatus used to electrolyse a concentrated aqueous solution  of sodium chloride. +\u2013a c db  (i)  which letter on the diagram, a, b, c or d, represents the electrolyte?   . .  [1]  (ii)  name the product formed at  the positive electrode,    the negative electrode.    [2] [total: 9]",
            "11": "11 0620/21/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use7 (a)  a student set up the apparatus shown below.   the concentrated hydrochloric acid gives off hydrogen chloride gas.   after 15 seconds, the damp blue litmus paper begins to turn red.   after 25 seconds, the litmus paper has turned completely red. damp blue litmus paper cotton wool soaked in concentrated hydrochloric acidlong glass tube at the startslightly red after 15 secondsall red after 25 seconds   use ideas about moving particles to explain these observations.   ...    ...    ...    ...    ... ..  [4]  (b)  hydrogen chloride reacts with ammonia to form a salt which has the formula nh4cl.   state the name of this salt.    ... ..  [1]  (c) (i)   hydrochloric acid reacts with iron to form iron( ii) chloride and hydrogen.   write a word equation for this reaction.   . .  [1]  (ii)  describe a test for iron( ii) ions.  test   .  result    [2]",
            "12": "12 0620/21/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (d)  a student investigates various methods of protecting iron from rusting. she sets up four  tubes as shown in the diagram below. tube 1 iron nail water irontube 2 tube 3 tube 4 oil ironwater iron completelycoated withplasticwater iron incompletelycoated withplastic  (i)  tube 1 contains unprotected iron. what is the purpose of this experiment?   . .  [1]  (ii)  state the names of the two substances needed for iron to rust.  ..  and  .. [2 ]  (iii)  explain why the iron in tube 4 does not rust.   . ...   . .  [1]  (iv)  explain why the iron in tube 3 eventually rusts.   . ...   . .  [1] [total: 13]",
            "13": "13 0620/21/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use8  the diagram shows a silvered light bulb. thin coil of tungsten wire  plastic copper wiresbrass lamp holderthin layer of silver alloy   some properties of metals used in the light bulb are shown in the table below. metal hardnesselectrical  conductivitymelting point / \u00b0cprice / $ per tonne brass hard good about 1000 7 000 copper fairly soft very good 1083 9 600silver fairly soft very good 962 1 300 000tungsten hard good 3410 450  (a) (i)   suggest why copper rather than tungsten is used for electrical wiring?   . .  [1]  (ii)  suggest why silver is not used for electrical wiring.   . .  [1]  (iii)  suggest two reasons why tungsten rather than copper is used to make the bulb  \ufb01 lament.   reason 1   .  reason 2  ...  [2] (iv)  explain why the copper wires are covered with plastic.   . ...   . .  [2]",
            "14": "14 0620/21/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (b)  brass is an alloy.   which one of the following diagrams, a, b, c or d, best represents an alloy? a b c d   ... ..  [1] [total: 7]",
            "15": "15 0620/21/m/j/13blank page \u00a9 ucles 2013",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/21/m/j/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s13_qp_22.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 may/june 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib13 06_0620_22/3rp\u00a9 ucles 2013 *2056544724*",
            "2": "2 0620/22/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  the structures of \ufb01 ve substances, a, b, c, d and e, are shown below. na+ cl \u2013 na+ cl \u2013 clclna+ na+cl \u2013cl \u2013na+ cl \u2013 na+ cl \u2013na+ na+cl \u2013cl \u2013 n hh h hch c hh ho ha db ec cc cccc ccccccc ccc cc cccc cc c ccc cc ccccc ccc  (a)  answer the following questions about these substances. each substance may be used  once, more than once or not at all.  (i) which two substances are elements? .  and  .  (ii)  which substance has a giant covalent structure? .  (iii)  which substance turns damp red litmus blue? .  (iv)  which substance is a product of fermentation? .  (v)  which substance is used as a lubricant? . [6]  (b)  complete the following sentences about compounds using words from the list below.  atom combined copper covalent  ionic metals molecules separated  a compound is a substance containing two or more types of  chemically   .   compounds such as water and sulfur dioxide exist as simple  .   others, such as sodium chloride, are giant  structures. [4] [total: 10]",
            "3": "3 0620/22/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  the table shows how the density of the transition elements varies across period 4. element ti v cr mn fe co ni cu density in g per cm34.50 7.20 7.20 7.86 8.90 8.90 8.92  (a)  describe the general  trend in density of the transition elements across period 4.   ... ..  [1]  (b)  suggest a value for the density of vanadium, v.   ... ..  [1]  (c)  many transition elements and their compounds are catalysts.   what is the meaning of the term catalyst  ?   ... ..  [1]  (d)  describe three  properties of transition metals, apart from catalytic activity, which make  them different from group i metals.  1.  ...   2.  ...   3.  ... ..  [3]  (e)  iron reacts with steam to form an oxide with the formula fe3o4.   complete the symbol equation for this reaction.  ...fe(s)  +  ...h2o(g)  \u2192  fe3o4(s)  +  4h2(g) [2]  (f)  iron reacts with sulfuric acid.   complete the word equation for this reaction. iron  +  sulfuric acid  \u2192    +     [2] [total: 10]",
            "4": "4 0620/22/m/j/13 \u00a9 ucles 2013for examiner\u2019s use3  the concentration of alkali in a solution can be determined from the results of a titration.   the apparatus used is shown below. abcd  (a)  state the name of each of these pieces of apparatus.  a .  b .  c .  d . [4]",
            "5": "5 0620/22/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b)  the graph below shows how the ph changes when an alkali is neutralised by an acid. 0 5 10 15 20 2514 1210 86420ph volume of acid added  / cm3  (i)  what is the ph of the alkali at the start of the experiment? ph = ...  [1]  (ii)  what volume of acid has been added when the ph is 12? ... cm3  [1]  (iii)  what is the value of the ph when the solution is neutral?   put a ring around the correct answer. ph 0        ph 5        ph 7        ph 9        ph 14 [1]",
            "6": "6 0620/22/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (c) (i)   which two of the following compounds could a farmer use to control the ph of soils  which are too acidic?   tick two boxes.  aluminium chloride calcium carbonate calcium oxide copper sulfate potassium chloride [2]  (ii)  explain why farmers need to control the ph of soils which are too acidic.   . ...   . .  [1] [total: 10]",
            "7": "7 0620/22/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use4  methane belongs to the alkane homologous series.  (a) (i)   draw the structure of methane showing all atoms and bonds. [1]  (ii)  state the name of one other member of the alkane homologous series.   . .  [1]  (iii)  methane is an atmospheric pollutant.   give one natural source of methane in the atmosphere.   . .  [1]  (iv)  methane burns in excess oxygen to form carbon dioxide and water.   complete the symbol equation for this reaction.  ch4  +  o2  \u2192    +  2h2o [2]  (b) (i)   in an oil re \ufb01 nery, hydrocarbons are separated into different fractions. on what  physical property does this fractionation depend?   . .  [1]  (ii)  match the fraction on the left with the use of the fraction on the right. the \ufb01 rst one  has been done for you. gasoline diesel fuel oil kerosene naphthafuel for lorries fuel for cars fuel for ships making chemicals fuel for jet aircraft [4] [total: 10]",
            "8": "8 0620/22/m/j/13 \u00a9 ucles 2013for examiner\u2019s use5  clean air is a mixture of gases.  (a)  state the composition of clean air and describe how it gets polluted by gases such as  sulfur dioxide, carbon monoxide and oxides of nitrogen.   in your answer, include  \u25cf the names and percentages of the two main gases present in clean air,  \u25cf the source of each of the pollutant gases named above.   ...    ...    ...    ...    ...    ... ..  [5]  (b)  lead is an atmospheric pollutant. it is extracted by heating ores containing lead sul \ufb01 de.  (i)  the structure of lead sul \ufb01 de is shown below. pb2+s2\u2013 pb2+s2\u2013 pb2+s2\u2013 pb2+s2\u2013 pb2+s2\u2013 pb2+s2\u2013   deduce the simplest formula for lead sul \ufb01 de.   . .  [1]  (ii)  the last stage in extracting lead involves reducing lead( ii) oxide with carbon. pbo  +  c  \u2192  pb  +  co   how does this equation show that lead oxide gets reduced?   . .  [1]",
            "9": "9 0620/22/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  dichloroethane used to be added to petrol to prevent the build-up of lead deposits in car  engines.   the structure of dichloroethane is shown below. c hh cc l cl hh  (i)  dichloroethane is a liquid.   describe the arrangement and closeness of the particles in a liquid.  arrangement  .. closeness  .  [2] (ii)  deduce the molecular formula for dichloroethane.   . .  [1]  (iii)  calculate the relative molecular mass of dichloroethane. you must show all your  working. [2] [total: 12]",
            "10": "10 0620/22/m/j/13 \u00a9 ucles 2013for examiner\u2019s use6 (a)   the table below describes the reaction of some metals with water. metal reaction calciumreacts rapidly with cold water producing many  bubbles of gas magnesiumreacts very slowly with cold water but reacts  rapidly with steam rubidiumreacts very rapidly with cold water producing  many bubbles of gas and will explode zinconly reacts with steam when in powdered form  and heated very strongly  put these metals in order of their reactivity. least reactive most reactive [2]  (b)  the list below shows part of the reactivity series. potassium sodium aluminium carbon zinc ironincreasing reactivity   give the names of two metals from this list that can be extracted from their oxide ores by  heating with carbon.  ..  and  .  [1]  (c)  a magnesium atom has 12 electrons.  (i)  complete the diagram below to show the electronic structure of an atom of  magnesium. mg [2]  (ii)  an isotope of magnesium has a nucleon number (mass number) of 26.   deduce the number of neutrons in one atom of this isotope of magnesium.   . .  [1] [total: 6]",
            "11": "11 0620/22/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use7  the table shows some properties of sulfur, sucrose (sugar) and zinc chloride. property sulfur sucrose zinc chloride state at room  temperaturesolid solid solid solubility in water insoluble soluble soluble electrical conductivity  of aqueous solutiondoes not conduct conducts structure molecular molecular ionic  (a)  suggest why an aqueous solution of zinc chloride conducts electricity.   ... ..  [1]  (b)  suggest why an aqueous solution of sucrose does not conduct electricity.   ... ..  [1]  (c)  suggest how you could separate a mixture of solid sucrose and solid sulfur.   ...    ...    ... ..  [2]  (d)  molten zinc chloride can be electrolysed using the apparatus shown below. +\u2013 a c db  (i)  which one of the letters, a, b, c or d, represents the cathode?   . .  [1]  (ii)  which one of the following substances is the most suitable for use as an electrode  in this electrolysis?   put a ring around the correct answer. copper            graphite            sodium            sulfur [1]",
            "12": "12 0620/22/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (iii)  predict the products of the electrolysis of molten zinc chloride at   the negative electrode,  ..   the positive electrode.  ..  [2]  (iv)  describe a test for chloride ions.  test   .  result    [3] [total: 11] 8  a student placed a spoonful of sugar in the bottom of a glass of cold tea and left it undisturbed  for several minutes.   after 2 minutes, she used a straw to taste some of the tea from the top of the glass. it did not  taste sweet.   after 10 minutes, the sugar had disappeared and the solution at the top of the glass tasted  sweet. cold tea sugar at the start after 2 minutes after 10 minutes  (a)  use the kinetic particle theory to explain these observations.   ...    ...    ...    ...    ... ..  [4]",
            "13": "13 0620/22/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b)  glucose is a sugar. the structure of a glucose molecule is shown below. co cch h hh h occ co h hh h h o o ho h  (i)  how many different types of atom are there in one molecule of glucose?   . .  [1]  (ii)  how many hydrogen atoms are there in one molecule of glucose?   . .  [1]  (iii)  on the diagram of the glucose molecule above, put a ring around an alcohol  functional group. [1]  (iv)  glucose is oxidised in the body by a process called respiration.   complete the word equation for respiration. glucose  +  oxygen  \u2192  .  +  water  . [1]  (v)  when glucose solution is fermented, ethanol is produced.   describe how you would carry out fermentation in the laboratory.   . ...   . ...   . .  [2]  (vi)  state one use of ethanol other than in alcoholic drinks.   . .  [1] [total: 11]",
            "14": "14 0620/22/m/j/13blank page \u00a9 ucles 2013",
            "15": "15 0620/22/m/j/13blank page \u00a9 ucles 2013",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/22/m/j/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s13_qp_23.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/23   paper 2 may/june 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib13 06_0620_23/3rp\u00a9 ucles 2013 *4714033593*",
            "2": "2 0620/23/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  the structures of \ufb01 ve atoms, a, b, c, d and e, are shown below. a b c d en ++ n ++n+ nn+ n+ n++proton neutronelectron  (a)  answer the following questions about these structures. each structure can be used once,  more than once or not at all.  (i)  which two structures are hydrogen atoms? .  and  .  (ii)  which structure represents an atom of a metal? .  (iii)  which structure has a proton (atomic) number of 3? .  (iv)  which structure has two neutrons in its nucleus? . [5]  (b)  the structure of carbon-12 can be written c612.   write the structure of atom d in a similar way. [1]  (c)  complete the following sentences about isotopes using words from the list below.  atoms energy iron molecules  neutrons protons radioactive stable   isotopes are atoms of the same element with the same number of ...  and different numbers of ... . some isotopes such as uranium-235 are  . uranium-235 can be used as a source of ... . [4] [total: 10]",
            "3": "3 0620/23/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  the table shows some physical properties of the group vii elements. halogenmelting point / \u00b0cboiling point / \u00b0catomic radius / nanometrescolour \ufb02 uorine \u2013220 \u2013188 pale yellow chlorine \u2013101 \u201335 0.099bromine \u20137 +59 0.114 red-browniodine +114 +184 0.133 grey-black  (a)  use the information in the table to explain why  (i)  chlorine is a gas at room temperature,  ..   . .  [1]  (ii)  bromine is a liquid at room temperature.  ...   . .  [1]  (b)  describe the trend in atomic radius going down the group from chlorine to iodine.   ... ..  [1]  (c)  suggest a value for the atomic radius of \ufb02 uorine.   ... ..  [1]  (d)  describe the colour of chlorine.   ... ..  [1]  (e)  a chlorine atom has 17 electrons.   complete the following structure to show how the electrons are arranged. cl [2]  (f)  chlorine reacts with potassium bromide to form potassium chloride and bromine.  (i)  complete the symbol equation for this reaction.  c l 2  +  ...kbr  \u2192  2kc l  +  ... [2]  (ii)  explain why iodine does not react with potassium bromide.   . .  [1] [total: 10]",
            "4": "4 0620/23/m/j/13 \u00a9 ucles 2013for examiner\u2019s use3  aluminium and gallium are in group iii of the periodic table.  (a)  the heat from your hand is suf \ufb01 cient to melt gallium.   describe the change in state from solid to liquid in terms of the kinetic particle theory.   in your answer include  \u25cf  the difference in arrangement and closeness of the particles in a solid and a liquid,  \u25cf  the difference in the motion of the particles in a solid and a liquid.   ...    ...    ...    ...    ... ..  [5]  (b)  gallium is a metal. describe three  physical properties of gallium which are typical of  most metals.  1.  ...   2.  ...   3.  ... ..  [3]  (c)  when it is a gas, gallium( iii) chloride has the structure shown below. gacl clcl clgacl cl   write the molecular formula for gallium( iii) chloride.   ... ..  [1]",
            "5": "5 0620/23/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (d)  aluminium is used to make high voltage electricity cables. electricity cables electricity pylon   the table shows some properties of four metals which could be used for overhead power  cables. metalrelative strengthdensity in g / cm3relative electrical  conductivityprice $ per tonne aluminium 9 2.70 0.4 2120 copper 30 8.92 0.7 9600tungsten 100 19.35 0.2 450steel 50 7.86 0.1 700  (i)  suggest why aluminium, rather than tungsten, is used in overhead power cables?   . .  [1]  (ii)  suggest why steel, rather than copper, is used as a core for overhead power cables.   . .  [1]  (iii)  give two reasons why aluminium is used for overhead power cables rather than  copper.  1.  .. ..  2.  ..   [2]  (e)  state one use of aluminium other than as an electrical conductor.   ... ..  [1] [total: 14]",
            "6": "6 0620/23/m/j/13 \u00a9 ucles 2013for examiner\u2019s use4  impure water needs to be treated if it is to be used in the home.  (a) (i)   explain why \ufb01 ltration and chlorination are used in the water treatment process.   . ...   . ...   . .  [2]  (ii)  state one use of water in the home.   . .  [1]  (b)  describe a chemical test for water.  test     result  .. .  [2]  (c) (i)   complete the diagram below to show the electron arrangement in a water molecule. o hh [1]  (ii)  is the bonding in water covalent or ionic?   give a reason for your answer.   . .  [1]  (d)  pure water is neutral. which one of these ph values is neutral?   put a ring around the correct answer. ph 0          ph 6          ph 7          ph 9          ph 13 [1]  (e)  water reacts with sodium. the products are sodium hydroxide and hydrogen.   write a word equation for this reaction. [1] [total: 9]",
            "7": "7 0620/23/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use5  energy is given out when fuels burn.  (a)  state the name given to a chemical reaction which releases energy.   ... ..  [1]  (b)  hydrogen can be used as a fuel.   complete the symbol equation for the burning of hydrogen in oxygen.  ...h2  +  ...  \u2192  2h2o [2]  (c)  gasoline is a mixture of hydrocarbons containing between 5 and 10 carbon atoms.   four of these hydrocarbons are shown below. c h hh c hhc hha c hh c hhhc h hh c hhc hhbc hh c hhc hhc hhc hhh c h hh c hhc hhcc hh c hhc hhhc h hh c hhc hhdc hh c hhc hhc hhh  (i)  which one of these structures, a, b, c or d, has the highest relative molecular  mass?   you are not expected to do any calculations.   . .  [1]  (ii)  give one use of gasoline.   . .  [1]",
            "8": "8 0620/23/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (d)  the table shows the boiling points of the straight-chain hydrocarbons in the gasoline  fraction. number of carbon atoms 5 6789 1 0 boiling point  / \u00b0c 36 69 126 151 174  (i)  on the grid below, plot a graph to show how the boiling point changes with the  number of carbon atoms in these hydrocarbons. draw a smooth curve through the points. 5 6 7 8 9 10180 160140120100 80604020boiling point /  \u00b0c number of carbon atoms [3]  (ii)  use your graph to deduce the boiling point of the hydrocarbon with 7 carbon atoms.  boiling point  ... \u00b0c  [1]",
            "9": "9 0620/23/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (e)  the alkanes are a homologous series of hydrocarbons.  (i)  what is meant by the term homologous series  ?   . ...   . .  [2]  (ii)  alkanes can be cracked to form alkenes and smaller alkanes.   state the conditions needed for cracking.   . ...   . .  [2] [total: 13]",
            "10": "10 0620/23/m/j/13 \u00a9 ucles 2013for examiner\u2019s use6  inks are mixtures of different dyes.  (a)  a student used paper chromatography to separate the dyes in a particular ink.   describe how paper chromatography is carried out. you may draw a diagram to help  explain your answer.   in your description include  \u25cf the apparatus you would use,  \u25cf how chromatography is carried out.   ...    ...    ...    ... ..  [4]  (b) the chromatogram below shows the results of a chromatography experiment.   x, y and z are pure dyes containing only one compound.   the dyes present in four different inks, d, e, f and g are also shown. xyzdefg  (i)  which ink, d, e, f or g, contains all the dyes x, y and z?   . .  [1]  (ii)  which ink, d, e, f or g, does not contain any of the dyes x, y and z?   . .  [1]  (iii)  which ink contains the greatest number of different dyes?   . .  [1]",
            "11": "11 0620/23/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  some inks contain ethanoic acid.   complete the structure of ethanoic acid. c h hh [1]  (d)  ethanoic acid can be used as a solvent.   what is the meaning of the term solvent  ?   ... ..  [1]  (e)  the structure of a dye called gambine r is shown below. cho cc hhhnoh cc cc cc hc h  (i)  how many different types of atom are there in one molecule of gambine r?   . .  [1]  (ii)  how many carbon atoms are there in one molecule of gambine r?   . .  [1] [total: 11]",
            "12": "12 0620/23/m/j/13 \u00a9 ucles 2013for examiner\u2019s use7  hydrogen peroxide, h2o2, decomposes in the presence of an enzyme called peroxidase. the  products of this reaction are water and oxygen.  (a) (i)   what is meant by the term enzyme ?   . ...   . .  [2]  (ii)  complete the symbol equation for this reaction.  ...h2o2  \u2192  2h2o  +  o2 [1]  (b)  a student followed the course of this reaction by measuring the volume of oxygen  released over a period of time.   the diagram below shows some results that he obtained using hydrogen peroxide at  three different concentrations. 0 20 40 60 80 10040 302010 0volume of oxygen  / cm3 time  / secondsconcentration of h2o2 0.4 mol  / dm3 0.2 mol  / dm3 0.1 mol  / dm3  (i)  describe how the concentration of hydrogen peroxide affects the rate of this reaction.   . .  [1]  (ii)  on the graph above, draw a line to show the course of the reaction when the starting  concentration of hydrogen peroxide is 0.3  mol  / dm3. [2]  (iii)  for the concentration of hydrogen peroxide of 0.4  mol  / dm3, deduce  \u25cf the volume of oxygen given off when the reaction is complete,  cm3  \u25cf the time it takes to produce 14  cm3 of oxygen.  seconds  [2]",
            "13": "13 0620/23/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  in the presence of sulfuric acid, hydrogen peroxide reacts with iodide ions to form iodine  and water. this involves the reduction of hydrogen peroxide.  (i)  what is the meaning of the term reduction  ?   . .  [1]  (ii)  complete the word equation for the reaction of sulfuric acid with calcium hydroxide.  sulfuric acid  +  calcium hydroxide  \u2192    +     [2] (iii)  describe a test for iodide ions.  test   .  result    [2] [total: 13]",
            "14": "14 0620/23/m/j/13blank page \u00a9 ucles 2013",
            "15": "15 0620/23/m/j/13blank page \u00a9 ucles 2013",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/23/m/j/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s13_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) may/june 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib13 06_0620_31/2rp\u00a9 ucles 2013 *2845008432*",
            "2": "2 0620/31/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  petroleum contains hydrocarbons which are separated by fractional distillation.  (a) (i)  complete the following de \ufb01 nition of a hydrocarbon.   a hydrocarbon is a compound which  .   . .  [2]  (ii)  explain what is meant by the term fractional distillation .   . ...   . ...   . .  [2]  (b)  some of the fractions obtained from petroleum are given below.   state a use for each fraction.  bitumen    lubricating fraction  ... paraf \ufb01 n fraction    gasoline fraction  .. [4] [total: 8] 2  an element, m, has the electron distribution 2 + 8 + 18 + 3.  (a)  which group in the periodic table is element m likely to be in?   ... ..  [1]  (b)   predict whether element m is a poor or a good conductor of electricity.   give a reason for your answer.   ... ..  [1]  (c)  binary compounds contain two atoms per molecule, for example hc l.   identify an element which could form a binary compound with element m.   ... ..  [1]  (d)  predict the formula of the sulfate of m. the formula of the sulfate ion is so 42\u2013.   ... ..  [1]",
            "3": "3 0620/31/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (e)  the hydroxide of m is a white powder which is insoluble in water.  describe how you could show that this hydroxide is amphoteric.   ...    ...    ... ..  [2] [total: 6] 3  a small piece of marble, caco3, was added to 5.0  cm3 of hydrochloric acid, concentration  1.0  mol  / dm3, at 25  \u00b0c. the time taken for the reaction to stop was measured. the experiment  was repeated using 5.0  cm3 of different solutions of acids. the acid was in excess in all of the  experiments.   typical results are given in the table. experiment temperature  / \u00b0c acid solution time  / min 1 25 hydrochloric acid 1.0  mol  / dm33 2 25 hydrochloric acid 0.5  mol  / dm37 3 25 ethanoic acid 1.0  mol  / dm310 4 15 hydrochloric acid 1.0  mol  / dm38  (a) (i)  explain why it is important that the pieces of marble are the same size and the same  shape.   . ...   . ...   . .  [2]  (ii)  how would you know when the reaction had stopped?   . .  [1]  (b)  the equation for the reaction in experiment 1 is: caco3(s)  +  2hc l (aq)  \u2192  cac l 2(aq)  +  co2(g)  +  h2o(l)   complete the following ionic equation. caco3(s)  +  2h+(aq)  \u2192     +    +   [1]",
            "4": "4 0620/31/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (c) (i)  explain why the reaction in experiment 1 is faster than the reaction in experiment 2.   . ...   . .  [1]  (ii)  the acids used for experiment 1 and experiment 3 have the same concentration.   explain why experiment 3 is slower than experiment 1.   . ...   . ...   . .  [2]  (iii)  explain in terms of collisions between reacting particles why experiment 4 is slower  than experiment 1.   . ...   . ...   . .  [3] [total: 10] 4  the structural formula of cyclohexane is drawn below. ch2 ch2 ch2 h2ch2c ch2  (a)  the name gives information about the structure of the compound.   hex because there are six carbon atoms and cyclo  because they are joined in a ring.   what information about the structure of this compound is given by the ending ane?   ...    ... ..  [2]  (b)  what are the molecular and empirical formulae of cyclohexane?   molecular formula .   empirical formula .. [2]",
            "5": "5 0620/31/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  draw the structural formula of cyclobutane. [1]  (d) (i)  deduce the molecular formula of hexene.   . .  [1]  (ii)  explain why cyclohexane and the alkene, hexene, are isomers.   . ...   . ...   . .  [2]  (e)  describe a test which would distinguish between cyclohexane and the unsaturated  hydrocarbon hexene.  test     result of test with cyclohexane  ..   ...    result of test with hexene  ..  ... ..  [3] [total: 11]",
            "6": "6 0620/31/m/j/13 \u00a9 ucles 2013for examiner\u2019s use5  the reactivity series shows the metals in order of reactivity.  (a)  the reactivity series can be established using displacement reactions. a piece of zinc is  added to aqueous lead nitrate. the zinc becomes coated with a black deposit of lead. zn  +  pb2+  \u2192  zn2+  +  pb   zinc is more reactive than lead.   the reactivity series can be written as a list of ionic equations.  .. \u2192 .. + .. most reactive metal  : the best reductant (reducing agent)  zn \u2192 zn2+ + 2e\u2013  fe \u2192 fe2+ + 2e\u2013  pb \u2192 pb2+ + 2e\u2013  cu \u2192 cu2+ + 2e\u2013  ag \u2192 ag+ + e\u2013  (i)  in the space at the top of the list, write an ionic equation for a metal which is more  reactive than zinc. [1]  (ii)   write an ionic equation for the reaction between aqueous silver( i) nitrate and zinc.   . .  [2]  (iii)  explain why the positive ions are likely to be oxidants (oxidising agents).   . .  [1]  (iv)  deduce which ion is the best oxidant (oxidising agent).   . .  [1]  (v)  which ion(s) in the list can oxidise lead metal?   . .  [1]",
            "7": "7 0620/31/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b)  a reactivity series can also be established by measuring the voltage of simple cells. the  diagram shows a simple cell. vvoltmeter copperelectrode sulfuric acidcadmium electrode   results from cells using the metals tin, cadmium, zinc and copper are given in the table  below. cellelectrode 1 positive electrodeelectrode 2 negative electrodevoltage  / volts 1 copper cadmium 0.74 2 copper tin 0.483 copper zinc 1.10   write the four metals in order of increasing reactivity and explain how you used the data  in the table to determine this order.   ...    ...    ... ..  [3] [total: 9] 6  ammonia is a compound which only contains the elements nitrogen and hydrogen. it is a  weak base.  (a) (i)  de\ufb01 ne the term base .   . .  [1]  (ii)  given aqueous solutions of ammonia and sodium hydroxide, both having a  concentration of 0.1  mol  / dm3, how could you show that ammonia is the weaker  base?   . ...   . ...   . .  [2]",
            "8": "8 0620/31/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (b)  ammonia is manufactured by the haber process. the economics of this process require  that as much ammonia as possible is made as quickly as possible.   explain how this can be done using the following information.   the conditions for the following reversible reaction are:  \u25cf 450  \u00b0c  \u25cf 200 atmospheres pressure  \u25cf iron catalyst n2(g)  +  3h2(g)    2nh3(g)       the reaction is exothermic   ...    ...    ...    ...    ...    ... ..  [5]  (c)  another compound which contains only nitrogen and hydrogen is hydrazine, n2h4.   complete the equation for the preparation of hydrazine from ammonia.  .nh3  +  nac l o  \u2192  n2h4  +    +  h2o [2]  (d)  the structural formula of hydrazine is given below. nnh hhh   draw a diagram showing the arrangement of the valency electrons in one molecule of  the covalent compound hydrazine.   use x to represent an electron from a nitrogen atom.   use o to represent an electron from a hydrogen atom. [3]",
            "9": "9 0620/31/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (e)  hydrazine is a weak base and it removes dissolved oxygen from water. it is added to  water in steel boilers to prevent rusting.  (i)  one way it reduces the rate of rusting is by changing the ph of water.   what effect would hydrazine have on the ph of water?   . .  [1]  (ii)  give a reason, other than ph, why hydrazine reduces the rate of rusting.   . .  [1] [total: 15] 7  the hydroxides of the group i metals are soluble in water. most other metal hydroxides are  insoluble in water.  (a) (i)  crystals of lithium chloride can be prepared from lithium hydroxide by titration. conical flaskburette filled with hydrochloric acid ofconcentration 2.20  mol  / dm3 25.0  cm3 of aqueous lithium hydroxide and indicator   25.0  cm3 of aqueous lithium hydroxide is pipetted into the conical \ufb02 ask.   a few drops of an indicator are added. dilute hydrochloric acid is added slowly to the  alkali until the indicator just changes colour. the volume of acid needed to neutralise the lithium hydroxide is noted.   a neutral solution of lithium chloride, which still contains the indicator, is left. describe  how you could obtain a neutral solution of lithium chloride which does not contain an  indicator.   . ...   . .  [2]",
            "10": "10 0620/31/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (ii)  you cannot prepare a neutral solution of magnesium chloride by the same method.  describe how you could prepare a neutral solution of magnesium chloride.   . ...   . ...   . .  [3]  (b)  the concentration of the hydrochloric acid was 2.20  mol  / dm3. the volume of acid needed  to neutralise the 25.0  cm3 of lithium hydroxide was 20.0  cm3. calculate the concentration  of the aqueous lithium hydroxide. lioh  +  hc l  \u2192  lic l  +  h2o   ...    ...    ... ..  [2]  (c)  lithium chloride forms three hydrates. they are lic l.h2o, lic l.2h2o and lic l.3h2o.   which one of these three hydrates contains 45.9  % of water?  show how you arrived at your answer.   ...    ...    ... ..  [3] [total: 10] 8  there are three types of giant structure - ionic, metallic and giant covalent.  (a)  in an ionic compound, the ions are held in a lattice by strong forces.  (i)  explain the term lattice .   . ...   . .  [2]  (ii)  explain how the ions are held together by strong forces.   . ...   . .  [1]",
            "11": "11 0620/31/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b)  describe the bonding in a typical metal.   ...    ...    ... ..  [3]  (c)  the electrical conductivities of the three types of giant structure are given in the following  table. type of structure conductivity of solid conductivity of liquid ionic poor good metallic good good giant covalent poor poor   explain the differences in electrical conductivity between the three types of giant structure  and the difference, if any, between the solid and liquid states of the same structure.   ...    ...    ...    ...    ... ..  [5] [total: 11]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/31/m/j/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s13_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) may/june 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib13 06_0620_32/2rp\u00a9 ucles 2013 *0737818166*",
            "2": "2 0620/32/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  air is a mixture of gases. the main constituents are the elements oxygen and nitrogen.  (a) (i)  name another element in air.   . .  [1]  (ii)  give the formula of a compound in unpolluted air.   . .  [1]  (b)  common pollutants present in air are the oxides of nitrogen and sulfur dioxide.  (i)  how are the oxides of nitrogen formed?   . ...   . ...   . .  [2]  (ii) how is sulfur dioxide formed?   . ...   . ...   . .  [2]  (iii)  these oxides are largely responsible for acid rain.   state two harmful effects of acid rain.   . ...   . .  [2]",
            "3": "3 0620/32/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  the percentage of oxygen in air can be determined by the following experiment. heatgas syringe containing 50 cm3 of airgas syringelarge pile of coppersmall pile of copper   the gas syringe contains 50  cm3 of air. the large pile of copper is heated and the air is  passed from one gas syringe to the other over the hot copper. the large pile of copper turns black. the gas is allowed to cool and its volume measured.   the small pile of copper is heated and the remaining gas passed over the hot copper. the copper does not turn black. the \ufb01 nal volume of gas left in the apparatus is less than 50  cm3.  (i)  explain why the copper in the large pile turns black.   . ...   . .  [2]  (ii)  why must the gas be allowed to cool before its volume is measured?   . .  [1]  (iii)  explain why the copper in the small pile did not turn black.   . .  [1]  (iv)  what is the approximate volume of the gas left in the apparatus?   . .  [1] [total: 13]",
            "4": "4 0620/32/m/j/13 \u00a9 ucles 2013for examiner\u2019s use2 (a)  the table below gives the number of protons, neutrons and electrons in atoms or ions.   complete the table.  the \ufb01 rst line is given as an example.   you will need to use the periodic table. particlenumber of protonsnumber of electronsnumber of neutronssymbol or formula a4 4 5 be49 b1 9 1 8 2 0 c3 0 3 0 3 5 d 8 10 8 e3 1 3 1 3 9 [6]  (b)  using the data in the table, explain how you can determine whether a particle is an atom,  a negative ion or a positive ion.   ...    ...    ... ..  [3] [total: 9] 3  the diagram shows some of the processes which determine the percentage of carbon dioxide in the atmosphere. carbon dioxide in atmosphere combustion photosynthesis respiration  (a)  explain how the following two processes alter the percentage of carbon dioxide in the atmosphere.  (i)  combustion   . ...   . ...   . .  [3]",
            "5": "5 0620/32/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (ii)  respiration   . ...   . ...   . .  [3]  (b)  photosynthesis reduces the percentage of carbon dioxide in the atmosphere.  (i)  complete the word equation for photosynthesis.  carbon dioxide  +  water  \u2192    +   [2]  (ii)  state two essential conditions for the above reaction to occur.   . ...   . .  [2] [total: 10] 4  at present the most important method of manufacturing hydrogen is steam reforming of  methane.  (a)  in the \ufb01 rst stage of the process, methane reacts with steam at 800  \u00b0c. ch4(g)  +  h2o(g)    3h2(g)  +  co(g)   in the second stage of the process, carbon monoxide reacts with steam at 200  \u00b0c. co(g)  +  h2o(g)    co2(g)  +  h2(g)  (i)  explain why the position of equilibrium in the \ufb01 rst reaction is affected by pressure but  the position of equilibrium in the second reaction is not.   . ...   . ...   . .  [2]  (ii)  suggest why a high temperature is needed in the \ufb01 rst reaction to get a high yield of  products but in the second reaction a high yield is obtained at a low temperature.   . ...   . .  [2]",
            "6": "6 0620/32/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (b)  two other ways of producing hydrogen are cracking and electrolysis.  (i)  hydrogen can be a product of the cracking of long chain alkanes.   complete the equation for the cracking of c8h18.  c8h18  \u2192  2  +  h2 [1]  (ii)  there are three products of the electrolysis of concentrated aqueous sodium  chloride. hydrogen is one of them.   write an equation for the electrode reaction which forms hydrogen.   . .  [2]  (iii)  name the other two products of the electrolysis of concentrated aqueous sodium  chloride and give a use of each one.  product  use  product  use  [4] [total: 11] 5  many monomer molecules react together to form one molecule of a polymer. this reaction is  called polymerisation.  (a)  the structural formula of the polymer, poly(chloroethene), is given below. this polymer  is also known as pvc. nc hh c clh  (i)  a major use of pvc is insulation of electric cables. pvc is a poor conductor of  electricity.   suggest another property which makes it suitable for this use.   . .  [1]  (ii)  one way of disposing of waste pvc is by burning it. this method has the disadvantage  that poisonous gases are formed.   suggest two poisonous gases which could be formed by the combustion of pvc.   . .  [2]",
            "7": "7 0620/32/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b) (i)  deduce the structural formula of the monomer from that of the polymer. nc hhh cch3   structural formula of monomer [1]  (ii)  deduce the structural formula of the polymer, poly(phenylethene), from the formula  of its monomer, phenylethene. cch hc6h5 h   structural formula of polymer [2]",
            "8": "8 0620/32/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (c)  the carbohydrate, glucose, polymerises to form the more complex carbohydrate starch.    if glucose is represented by ho oh  then the structural formula of starch is as drawn below. o o   how does the polymerisation of glucose differ from that of an alkene such as phenylethene?   ...    ...    ... ..  [2] [total: 8] 6  aluminium is an important metal with a wide range of uses.  (a)  aluminium is obtained by the electrolysis of aluminium oxide dissolved in molten cryolite. carbon cathode (\u2013)oxygen given off at carbon anode (+) molten mixture of aluminium oxide and cryolite aluminiumwaste gases  (i)  solid aluminium oxide is a poor conductor of electricity. it conducts either when  molten or when dissolved in molten cryolite. explain why.   . ...   . ...   . .  [2]  (ii)  why is a solution of aluminium oxide in molten cryolite used rather than molten  aluminium oxide?   . .  [1]",
            "9": "9 0620/32/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (iii)  explain why the carbon anodes need to be replaced periodically.   . .  [1]  (iv)  one reason why graphite is used for the electrodes is that it is a good conductor of  electricity. give another reason.   . .  [1]  (b)  aluminium is used to make food containers because it resists corrosion.   explain why it is not attacked by the acids in food.   ...    ... ..  [2]  (c)  aluminium is used for overhead power (electricity) cables which usually have a steel  core. aluminium steel core  (i)  give two properties of aluminium which make it suitable for this use.   . ...   . .  [2]  (ii)   explain why the cables have a steel core.   . ...   . .  [1] [total: 10]",
            "10": "10 0620/32/m/j/13 \u00a9 ucles 2013for examiner\u2019s use7  the ester linkage showing all the bonds is drawn as co o   or more simply it can be written as \u2013coo\u2013.  (a) (i)  give the structural formula of the ester ethyl ethanoate. [1]  (ii)  deduce the name of the ester formed from methanoic acid and butanol.   . .  [1]  (b) (i)  which group of naturally occurring compounds contains the ester linkage?   . .  [1]  (ii)  draw the structural formula of the polyester formed from the following monomers. hoocc6h4cooh  and  hoch2ch2oh   you are advised to use the simpler form of the ester linkage. [3]",
            "11": "11 0620/32/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  esters can be used as solvents in chromatography. the following shows a chromatogram  of plant acids. solvent front baseline sample 1 sample 2the cross representsthe centre of the spot   an ester was used as the solvent and the chromatogram was sprayed with bromothymol  blue.  (i)  suggest why it was necessary to spray the chromatogram.   . ...   . .  [2]  (ii)  explain what is meant by the rf value of a sample.   . ...   . .  [1]",
            "12": "12 0620/32/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (iii)  calculate the rf values of the two samples and use the data in the table to identify  the plant acids. plant acid rf value tartaric acid 0.22 citric acid 0.30oxalic acid 0.36malic acid 0.46succinic acid 0.60  sample 1 r f  =   it is . acid.  sample 2 rf  =   it is . acid. [2] [total: 11] 8 (a)  de\ufb01 ne the following  (i)  the mole   . ...   . .  [1]  (ii)  the avogadro constant   . ...   . .  [1]  (b)  which two of the following contain the same number of molecules?   show how you arrived at your answer.  2.0  g of methane, ch4  8.0  g of oxygen, o2  2.0  g of ozone, o3  8.0  g of sulfur dioxide, so2   ...    ...    ... ..  [2]",
            "13": "13 0620/32/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c) 4.8  g of calcium is added to 3.6  g of water. the following reaction occurs. ca  +  2h2o  \u2192  ca(oh)2  +  h2  (i)  the number of moles of ca =    the number of moles of h2o =  [1]  (ii)  which reagent is in excess? explain your choice.   . ...   . .  [2]  (iii)  calculate the mass of the reagent named in (ii) which remained at the end of the  experiment.   . ...   . .  [1] [total: 8]",
            "14": "14 0620/32/m/j/13blank page \u00a9 ucles 2013",
            "15": "15 0620/32/m/j/13blank page \u00a9 ucles 2013",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/32/m/j/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s13_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) may/june 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib13 06_0620_33/2rp\u00a9 ucles 2013 *6258911381*",
            "2": "2 0620/33/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  substances can be classi \ufb01 ed as: elements        mixtures        compounds   elements can be divided into: metals        non-metals  (a)  de\ufb01 ne each of the following terms.  (i)  element   . ...   . .  [2]  (ii)  compound   . ...   . .  [2]  (iii)  mixture   . ...   . .  [1]  (b)  classify each of the following as either an element, compound or mixture.  (i)  brass    [1 ]  (ii)  carbon dioxide  .  [1]  (iii)  copper  ..  [1]  (c)  which physical property is used to distinguish between metals and non-metals?   it is possessed by all metals but by only one non-metal.   ... ..  [1] [total: 9]",
            "3": "3 0620/33/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  one of the factors which determine the reaction rate of solids is particle size.  (a)  a mixture of \ufb01 nely powdered aluminium and air may explode when ignited.   an explosion is a very fast exothermic reaction. this causes a large and sudden increase  in temperature.   explain each of the following in terms of collisions between reacting particles.  (i)  why is the reaction between \ufb01 nely powdered aluminium and air very fast?   . ...   . .  [2]  (ii)  explain why for most reactions the rate of reaction decreases with time.   . ...   . .  [2]  (iii)  suggest an explanation why the rate of reaction in an explosion could increase rather than decrease with time.   . ...   . ...   . .  [3]  (b) (i)  give another example of a substance other than a metal which, when \ufb01 nely  powdered, might explode when ignited in air.   . .  [1]  (ii)  describe a simple test-tube reaction which shows the effect of particle size on the rate at which a solid reacts with a solution.   . ...   . ...   . .  [3] [total: 11]",
            "4": "4 0620/33/m/j/13 \u00a9 ucles 2013for examiner\u2019s use3  iron from the blast furnace is impure. it contains 5% of impurities, mainly carbon, sulfur,  silicon and phosphorus. almost all of this impure iron is converted into the alloy, mild steel.  (a) (i)  state a use of mild steel.   . .  [1]  (ii)  name and give a use of another iron-containing alloy.  name   ..  use  ...  [2]  (b)  the oxides of carbon and sulfur are gases. the oxides of silicon and phosphorus are not.   explain how these impurities are removed from the impure iron when it is converted into mild steel.   ...    ...    ...    ...    ... ..  [5] [total: 8] 4  germanium is an element in group iv. the electron distribution of a germanium atom is2 + 8 + 18 + 4. it has oxidation states of +2 and +4.  (a)  germanium forms a series of saturated hydrides similar to the alkanes.  (i)  draw the structural formula of the hydride which contains three germanium atoms per molecule. [1]  (ii)  predict the general formula of the germanium hydrides.   . .  [1]",
            "5": "5 0620/33/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b)  draw a diagram showing the arrangement of the valency electrons in one molecule of  the covalent compound germanium( iv) chloride, gec l 4.  use o to represent an electron from a chlorine atom.  use x to represent an electron from a germanium atom. [2]  (c)  describe the structure of the giant covalent compound germanium( iv) oxide, geo2.   it has a similar structure to that of silicon( iv) oxide.   ...    ...    ... ..  [3]  (d)  is the change gec l 2 to gec l 4 reduction, oxidation or neither? give a reason for your  choice.   ...    ... ..  [2] [total: 9] 5  all metal nitrates decompose when heated. a few form a nitrite and oxygen. most form the  metal oxide, oxygen and a brown gas called nitrogen dioxide.  (a) (i)  name a metal whose nitrate decomposes to form the metal nitrite and oxygen.   . .  [1]  (ii)  complete the equation for the action of heat on lead( ii) nitrate.  ..pb(no3)2  \u2192  .  +  ..no2  +  o2 [2]  (iii)  suggest why the nitrate of the metal, named in (a)(i) , decomposes less readily than  lead( ii) nitrate.   . ...   . .  [2]",
            "6": "6 0620/33/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (b)  almost all samples of nitrogen dioxide are an equilibrium mixture of nitrogen dioxide,  no2, and dinitrogen tetroxide, n2o4. forward reaction reverse reactionn2o4(g) colourless2no2(g) dark brown   in the forward reaction, a bond forms between the two nitrogen dioxide molecules. no2  +  no2  \u2192  o2n \u2013 no2  (i)  explain the term equilibrium mixture .   . ...   . .  [1]  (ii)  the syringe contains a sample of the equilibrium mixture. the plunger was pulled  back reducing the pressure.   how would the colour of the gas inside the syringe change? give an explanation for  your answer. equilibrium mixture sealed end gas syringe   . ...   . ...   . .  [3]  (iii)  a sealed tube containing an equilibrium mixture of nitrogen dioxide and dinitrogen  tetroxide was placed in a beaker of ice cold water.   the colour of the mixture changed from brown to pale yellow.   is the forward reaction exothermic or endothermic? give an explanation for your  choice.   . ...   . .  [2]  (iv)  what other piece of information given in the equation supports your answer to (iii)? no2  +  no2  \u2192  o2n\u2013no2   . .  [1] [total: 12]",
            "7": "7 0620/33/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use6  sulfuric acid and malonic acid are both dibasic acids. one mole of a dibasic acid can form  two moles of hydrogen ions. h2so4  \u2192  2h+  +  so42\u2013   dibasic acids can form salts of the type na2x and cax.  (a)  malonic acid is a white crystalline solid which is soluble in water. it melts at 135  \u00b0c.   the structural formula of malonic acid is given below. it forms salts called malonates. ch2(cooh)2  or  hooc  \u2013 ch2 \u2013 cooh  (i)  how could you determine if a sample of malonic acid is pure?  technique used  .. result if pure  .  [2] (ii)  what is the molecular formula of malonic acid?   . .  [1]  (iii)  when malonic acid is heated there are two products, carbon dioxide and a simpler  carboxylic acid. deduce the name and molecular formula of this acid.   . ...   . .  [2]  (iv)  malonic acid reacts with ethanol to form a colourless liquid which has a \u2018fruity\u2019 smell.   its structural formula is given below. cco oo och2 ch2ch3 ch2 ch3   what type of compound contains the group which is circled?   . .  [1]",
            "8": "8 0620/33/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (b) (i)  suggest why a solution of malonic acid, concentration 0.2  mol  / dm3, has a higher ph  than one of sulfuric acid of the same concentration.   . .  [1]  (ii)  describe a test, other than measuring ph, which can be carried out on both acid  solutions to con \ufb01 rm the explanation given in (b)(i)  for the different ph values of the  two acids.   . ...   . .  [2]  (c)  complete the following equations for reactions of these two acids.  (i) sodium hydroxide  +  malonic acid  \u2192    +   [1]   (ii) cuo  +  h 2so4  \u2192    +    [2]  (iii) mg  +  ch2(cooh)2  \u2192    +   [2]  (iv) k2co3  +  h2so4  \u2192    +    +   [2] [total: 16] 7  alkanes and alkenes are both series of hydrocarbons.  (a) (i)  explain the term hydrocarbon .   . ...   . .  [1]  (ii)  what is the difference between these two series of hydrocarbons?   . ...   . .  [2]  (b)  alkenes and simpler alkanes are made from long-chain alkanes by cracking.   complete the following equation for the cracking of the alkane c20h42.  c20h42  \u2192  2c4h8  +  2c2h4  +  ... [1]",
            "9": "9 0620/33/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c) alkenes such as butene and ethene are more reactive than alkanes.   alkenes are used in the petrochemical industry to make a range of products, which  includes polymers and alcohols.  (i)  dibromoethane is used as a pesticide. complete the equation for its preparation  from ethene. c c +    br2    \u2192h hhh [1]  (ii)  the structural formula of a poly(alkene) is given below. ncch3 cch3 hh   deduce the structural formula of its monomer. [2]  (iii)  how is butanol made from butene, ch3 \u2013 ch2 \u2013 ch  = ch2? include an equation in  your answer.   . ...   . .  [2]  (iv)  cracking changes alkanes into alkenes. how could an alkene be converted into an  alkane? include an equation in your answer.   . ...   . .  [2]",
            "10": "10 0620/33/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (d)  20  cm3 of a hydrocarbon was burnt in 175  cm3 of oxygen. after cooling, the volume of  the remaining gases was 125  cm3. the addition of aqueous sodium hydroxide removed  carbon dioxide leaving 25  cm3 of unreacted oxygen.  (i)  volume of oxygen used = .. cm3 [1]  (ii)  volume of carbon dioxide formed = .. cm3 [1]  (iii)  deduce the formula of the hydrocarbon and the balanced equation for the reaction.   . ...   . ...   . ...   . .  [2] [total: 15]",
            "11": "11 0620/33/m/j/13blank page \u00a9 ucles 2013",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/33/m/j/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s13_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test may/june 2013  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib13 06_0620_51/3rp\u00a9 ucles 2013 *8601854076* for examiner\u2019s use total",
            "2": "2 0620/51/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  you are going to investigate what happens when two different solids, c and d, react with  excess dilute hydrochloric acid.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out \ufb01 ve experiments.  (a)  experiment 1   use a measuring cylinder to pour 30  cm3 of dilute hydrochloric acid into the polystyrene  cup supported in the beaker provided. measure the temperature of the dilute hydrochloric acid and record it in the table below. add 1  g of solid c to the dilute hydrochloric acid and  stir the mixture with the thermometer.   measure the maximum temperature reached by the liquid mixture. record your result in  the table.  (b)  experiment 2   empty the polystyrene cup and rinse it with water.    repeat experiment 1 using 2  g of solid c.   record your results in the table.  (c)  experiments 3 and 4   repeat experiment 2 using 3  g and then 5  g of solid c.   record your results in the table.  complete the \ufb01 nal column in the table. experimentmass of solid c / ginitial temperature of acid  / \u00b0cmaximum temperature reached  / \u00b0ctemperature change  / \u00b0c 1 234 [4]",
            "3": "3 0620/51/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (d)   experiment 5   repeat experiment 1 using all of the solid d provided. measure the minimum temperature  reached by the liquid mixture. record your results in the spaces below.  initial temperature of dilute hydrochloric acid =  . \u00b0c  final temperature of liquid mixture =  . \u00b0c  temperature change =  . \u00b0c [2]  (e) plot the results for experiments 1, 2, 3 and 4 on the grid and draw a straight line graph. 0123 mass of solid c added  / g456temperature change  / \u00b0c [4]  (f) (i)  from your graph , deduce the temperature change of the solution when 6  g of solid  c is added to 30  cm3 of dilute hydrochloric acid.   show clearly on the grid  how you worked out your answer.    \u00b0c [2]  (ii)  from your graph , deduce the mass of solid c that would give a temperature rise of  9 \u00b0c when added to 30  cm3 of dilute hydrochloric acid.   show clearly on the grid  how you worked out your answer.   . ...   . .  [2]",
            "4": "4 0620/51/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (g)  what type of chemical process occurs when solid d reacts with dilute hydrochloric acid?   ... ..  [1]  (h)  suggest the effect on the results if experiment 3 was repeated using 60  cm3 of dilute  hydrochloric acid.   ...    ... ..  [2]  (i)  predict the temperature of the solution in experiment 4 after 1 hour. explain your answer.   ...    ... ..  [2]  (j)  when carrying out the experiments, what would be one advantage and one disadvantage  of taking the temperature readings after exactly one minute?  advantage  ... ..   ...   disadvantage      ... ..  [2] [total: 21]",
            "5": "5 0620/51/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  you are provided with two different liquids, a and b.   a is an aqueous solution and b is a pure liquid.   carry out the following tests on a and b, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on liquid a divide liquid a into four equal portions in  separate test-tubes. (a)  describe the colour and smell of liquid a.   using a teat pipette, add a few drops of  the liquid to universal indicator paper. describe the colour and state the ph.  [1]   [2] (b)  to the second portion of liquid a, add a  piece of magnesium ribbon.   after two minutes, test the gas given off  with a splint. ...  ...  [3] (c)  to the third portion of liquid a, add a  marble chip.   [2] (d)  to the fourth portion of liquid a, add a  spatula measure of copper oxide.   heat the solution gently and leave to  settle.   [1]",
            "6": "6 0620/51/m/j/13 \u00a9 ucles 2013for examiner\u2019s usetests observations tests on liquid b (e) (i)   to about 1  cm3 of liquid b, add a  few drops of dilute sulfuric acid followed by aqueous potassium  dichromate( vi). heat the mixture to  boiling.  (ii)  repeat (e)(i)  using aqueous  potassium manganate( vii) instead  of potassium dichromate( vi). ..   [2]  ..   [2] (f)  place a few drops of liquid b on a dry  watch glass. touch the surface of the liquid with a lighted splint.   [2]  (g)  identify liquid a.   ... ..  [2]  (h)  what conclusions can you draw about liquid b?   ... ..  [2] [total: 19]",
            "7": "7 0620/51/m/j/13blank page \u00a9 ucles 2013",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/51/m/j/13notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2013"
        },
        "0620_s13_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test may/june 2013  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 6 printed pages and 2 blank pages. [turn overib13 06_0620_52/2rp\u00a9 ucles 2013 *7326112403* for examiner\u2019s use total",
            "2": "2 0620/52/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  you are going to investigate the reaction between solution a, aqueous potassium  manganate( vii), and two different solutions, b and c, of an acidic solution of a sodium salt.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   fill the burette with the solution a of potassium manganate( vii) to the 0.0  cm3 mark.    using a measuring cylinder, pour 25  cm3 of solution b into the conical \ufb02 ask.   place the \ufb02 ask on a tripod and gauze and heat the mixture in the \ufb02 ask to about 80  \u00b0c.   remove the \ufb02 ask from the tripod and place it on the white tile under the burette. slowly  add 1  cm3 of the solution a to the \ufb02 ask, with shaking. continue to add solution a to the  \ufb02 ask until the mixture just turns permanently pink. record the burette reading in the table  and complete the table.   pour away the contents of the conical \ufb02 ask and rinse the \ufb02 ask with distilled water. \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]  (b)  experiment 2   re\ufb01 ll the burette with the solution a of potassium manganate( vii).   using a measuring cylinder, pour 25  cm3 of solution c into the conical \ufb02 ask. heat the  mixture in the \ufb02 ask to about 80  \u00b0c.   remove the \ufb02 ask from the tripod and place it on the white tile under the burette. slowly  add 1  cm3 of the solution a to the \ufb02 ask, with shaking. continue to add solution a to the  \ufb02 ask until the mixture just turns permanently pink. record the burette readings in the  table and complete the table. \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]",
            "3": "3 0620/52/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c) (i)  suggest why the mixture in the \ufb02 ask is heated before adding the potassium  manganate( vii) solution.   . .  [1]  (ii)  what colour change was observed when potassium manganate( vii) solution was  added to the \ufb02 ask in experiment 1?  from  to  [2] (iii)  why is an indicator not added to the \ufb02 ask?   . .  [1]  (d) (i)  in which experiment was the greater volume of potassium manganate( vii) solution  used?   . .  [1]  (ii)  compare the volumes of potassium manganate( vii) used in experiments 1 and 2.   . .  [1]  (iii)  suggest an explanation for the difference in volumes.   . ...   . ...   . .  [2]  (e)  if experiment 2 was repeated using 12.5  cm3 of solution c, what volume of potassium  manganate( vii) solution would be used? explain your answer.   ...    ... ..  [3]  (f)  a redox reaction occurs when potassium manganate( vii) reacts with solutions b and c.  explain the term redox reaction .   ...    ... ..  [2]  (g)  give one advantage and one disadvantage of using a measuring cylinder for solution c.  advantage  ... ..  disadvantage  ..  [2] [total: 21]",
            "4": "4 0620/52/m/j/13 \u00a9 ucles 2013for examiner\u2019s use2  you are provided with a mixture of two solids, r and s.   solid r is water-soluble and solid s is insoluble.   carry out the following tests on the mixture, recording all of your observations in the table.   conclusions must not be written in the table. tests observations add about 15  cm3 of distilled water to the  mixture in a boiling tube.shake the boiling tube for one minute. filter the contents of the boiling tube, keeping  the \ufb01 ltrate and residue for the following tests.  divide the \ufb01 ltrate into \ufb01 ve test-tubes.  [1] tests on the \ufb01 ltrate (a)  use ph indicator paper to measure the  ph of the \ufb01 rst portion of the \ufb01 ltrate.   [1] (b) (i)   add several drops of aqueous sodium  hydroxide to the second portion of the solution and shake the test-tube.    now add a large excess of aqueous  sodium hydroxide.  (ii)   using the third portion of solution,  repeat test (b)(i)  using aqueous  ammonia instead of aqueous sodium hydroxide. ..   [2]  ..   [2] (c)  add about 1  cm3 of dilute nitric acid to the  fourth portion of the solution followed by aqueous silver nitrate.   [1] (d)  to the \ufb01 fth portion of the solution add  about 1  cm3 of dilute nitric acid followed  by aqueous barium nitrate.   [2]",
            "5": "5 0620/52/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s usetests observations tests on the residue use a spatula to transfer some of the residue  into the bottom of a test-tube. (e)  to the residue, add about 2  cm3 of dilute  hydrochloric acid.   test the gas given off.   now add a large excess of aqueous  sodium hydroxide to the mixture. ..  ..  [3]   [2]  (f)  what conclusions can you draw about solid r?   ...    ... ..  [2]  (g)  name the gas given off in test (e).   ... ..  [1]  (h)  identify solid s.   ... ..  [2] [total: 19]",
            "6": "6 0620/52/m/j/13blank page \u00a9 ucles 2013",
            "7": "7 0620/52/m/j/13blank page \u00a9 ucles 2013",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/52/m/j/13notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2013"
        },
        "0620_s13_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test may/june 2013  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 6 printed pages and 2 blank pages. [turn overib13 06_0620_53/rp\u00a9 ucles 2013 *8508882337* for examiner\u2019s use total",
            "2": "2 0620/53/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  you are going to investigate the reaction between potassium hydrogen carbonate and two  aqueous solutions of dilute hydrochloric acid of different concentrations, labelled f and g.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   use a measuring cylinder to pour 20  cm3 of distilled water into a conical \ufb02 ask. add a  0.3  g sample of potassium hydrogen carbonate to the conical \ufb02 ask and shake the \ufb02 ask  to dissolve the solid.   add \ufb01 ve drops of methyl orange indicator to the conical \ufb02 ask.   fill the burette provided up to the 0.0  cm3 mark with the solution f of dilute hydrochloric  acid. add acid f from the burette 1  cm3 at a time, while shaking the \ufb02 ask, until the solution  just changes colour. record the burette readings in the table below and complete the  table.  (b)  experiment 2   empty the conical \ufb02 ask and rinse it with distilled water.   pour away the contents of the burette and rinse the burette with the solution g of dilute  hydrochloric acid.   repeat experiment 1, using solution g instead of solution f.   record the burette readings in the table below and complete the table. experiment 1 experiment 2 \ufb01 nal reading  / cm3 initial reading  / cm3 difference  / cm3 [6]",
            "3": "3 0620/53/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  what colour change was observed in the contents of the \ufb02 ask after the hydrochloric acid  was added to the \ufb02 ask?  from  to . ... [2]  (d)  what type of chemical reaction occurs when hydrochloric acid reacts with potassium hydrogen carbonate?   ... ..  [1]  (e)  complete the sentence below.   experiment  needed the smallest volume of hydrochloric acid to change the colour of the methyl orange. [1]  (f) (i)   compare the volumes of hydrochloric acid used in experiments 1 and 2.   . .  [1]  (ii)  the most concentrated solution of hydrochloric acid is solution .. . [1]  (g)   if experiment 2 was repeated using 0.6  g of potassium hydrogen carbonate, what volume  of hydrochloric acid would be needed?   ... ..  [2]  (h)  what would be a more accurate method of measuring the volume of the distilled water?   ... ..  [1]  (i)  what would be the effect on the results if the solutions of potassiumhydrogen carbonate were warmed before adding the hydrochloric acid? give a reason for your answer.  effect on results  ... .  reason ..  [2]  (j)  describe a different  method of \ufb01 nding out which of the solutions of hydrochloric acid, f  or g, is the more concentrated.   ...    ...    ...    ...    ... ..  [3] [total: 20]",
            "4": "4 0620/53/m/j/13 \u00a9 ucles 2013for examiner\u2019s use2  you are provided with two solids, h and i, which are both salts.   carry out the following tests on each solid, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solid h add all of h to about 10  cm3 of distilled water  in a test-tube and shake to dissolve. divide the solution into three equal portions in  test-tubes, and carry out the following tests. (a)  describe the appearance of the solution.   add about 1  cm3 of dilute hydrochloric  acid to the \ufb01 rst portion of the solution.  [1]   [1] (b)  to the second portion of the solution, add  drops of aqueous sodium hydroxide until a change is seen.   heat the mixture gently  for two minutes  and stir the mixture. allow the mixture to settle.   remove the liquid with a teat pipette.add about 2  cm3 of dilute nitric acid to the  solid and heat the mixture gently .  [2]  ..   [2]   [1] (c)  to the third portion of the solution, add  drops of aqueous ammonia until a change is seen.   now add an excess of aqueous ammonia to the mixture.  [2]  ..   [2]",
            "5": "5 0620/53/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s usetests observations tests on solid i (d)  place about half of solid i into a dry  test-tube. heat the test-tube gently, then  strongly. test the gas given off with a lighted splint.   leave the test-tube to cool for \ufb01 ve  minutes and then add about 1  cm3 of dilute  hydrochloric acid to the test-tube. test the gas with a lighted splint. ..   [2]  ..   [2] (e)  add the rest of solid i to about 2  cm3 of  dilute nitric acid in a test-tube. warm the  solution and smell the mixture.   [1]  (f)  what conclusions can you draw about solid h?   ...    ... ..  [2]  (g)  what conclusions can you draw about solid i?   ...    ... ..  [2] [total: 20]",
            "6": "6 0620/53/m/j/13blank page \u00a9 ucles 2013",
            "7": "7 0620/53/m/j/13blank page \u00a9 ucles 2013",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/53/m/j/13notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2013"
        },
        "0620_s13_qp_61.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical may/june 2013  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib13 06_0620_61/2rp\u00a9 ucles 2013 *0139348906*",
            "2": "2 0620/61/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  electricity was passed through a solution of concentrated hydrochloric acid using the  apparatus shown. hydrogen concentrated hydrochloric acid + \u2013  (a)  complete the boxes to identify the parts of the apparatus labelled. [2]  (b)  describe the test for hydrogen.  test     result  .. .  [2]  (c)  describe how a sample of the gas given off at the positive electrode could be collected and its volume measured.   ...    ...    ... ..  [2]  (d)  the experiment was repeated using a concentrated aqueous solution of sodium chloride instead of hydrochloric acid.  (i)  state the name of the solution formed.   . .  [1]  (ii)  give a test to show the presence of this product.   . .  [1] [total: 8]",
            "3": "3 0620/61/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  a student found a recipe for making elderberry wine by fermentation.  1  kg elderberries  0.5  kg sugar  10  g yeast granules  3  dm3 water   the student decided to make some elderberry wine using the apparatus below. airlock water fermenting mixture   the student carried out the following method.   step 1 the elderberries were crushed.  step 2  the crushed elderberries and sugar were added to the water and the mixture was  boiled for ten minutes. the crushed elderberries were then separated from the mixture.  step 3  yeast was added to the liquid when it had cooled to room temperature.  (a)  suggest the purpose of the airlock in the apparatus.   ... ..  [1]  (b)  what apparatus could be used in step 1?   ... ..  [1]  (c)  draw a labelled diagram of the apparatus used to separate the crushed elderberries from the mixture in step 2. [2]  (d)  why was the yeast in step 3 not added until the liquid was at room temperature?   ... ..  [1]",
            "4": "4 0620/61/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (e) (i)   state one observation during the fermentation.   . .  [1]  (ii)  suggest how the rate of the fermentation reaction could be measured.   . ...   . .  [2]  (f)  name the method that could be used to separate ethanol from the fermented mixture.   ... ..  [1] [total: 9]",
            "5": "5 0620/61/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use3  a student investigated the reaction between two different solids, c and d, and excess dilute  hydrochloric acid.   five experiments were carried out.  (a) experiment 1   a measuring cylinder was used to pour 30  cm3 of dilute hydrochloric acid into a polystyrene  cup. the temperature of the dilute hydrochloric acid was measured. 1  g of solid c was  added to the dilute hydrochloric acid and the mixture stirred with a thermometer.   the maximum temperature reached by the liquid mixture was measured.  (b) experiment 2   the polystyrene cup was emptied and rinsed with water.   experiment 1 was repeated using 2  g of solid c.  (c) experiments 3 and 4   experiment 2 was repeated using 3  g and then 5  g of solid c.   use the thermometer diagrams to record the results in the table below.   complete the \ufb01 nal column in the table. experimentmass of  solid c / gthermometer diagraminitial  temperature  of acid  / \u00b0cthermometer diagrammaximum  temperature  reached  / \u00b0ctemperature difference / \u00b0c 130 25 2030 25 20 230 25 2035 30 25 330 25 2035 30 25 430 25 2035 30 25 [3]",
            "6": "6 0620/61/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (d)  experiment 5   experiment 1 was repeated using solid d. use the thermometer diagrams to record the  results in the spaces below. 25 20 15 initial temperature of acid20 15 10 final temperature of liquid mixture   initial temperature of dilute hydrochloric acid =  ... \u00b0c   \ufb01 nal temperature of liquid mixture =   \u00b0c   temperature change =  . \u00b0c [2]  (e)  plot the results for experiments 1, 2, 3 and 4 on the grid and draw a straight line graph. 0 1 2 3 4 5 615 10 5 0temperature difference  / \u00b0c mass of solid c / g [4]",
            "7": "7 0620/61/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (f) (i)   from your graph , deduce the temperature of the solution when 6  g of solid c is  added to 30  cm3 of dilute hydrochloric acid.   show clearly on the grid  how you worked out your answer.  ... \u00b0c [2]  (ii)  from your graph , deduce the mass of solid c that would give a temperature rise of  9 \u00b0c when added to 30  cm3 of dilute hydrochloric acid.   . ...   . .  [2]  (g)  what type of chemical process occurs when solid d reacts with dilute hydrochloric acid?   ... ..  [1]  (h)  suggest the effect on the results if experiment 3 was repeated using 60  cm3 of dilute  hydrochloric acid.   ...    ... ..  [2]  (i)  predict the temperature of the solution in experiment 4 after 1 hour. explain your answer.   ...    ... ..  [2]  (j)   when carrying out the experiments, what would be one advantage and one disadvantage  of taking the temperature readings after exactly one minute?   advantage   .   ...    disadvantage  . ...   ... ..  [2] [total: 20]",
            "8": "8 0620/61/m/j/13 \u00a9 ucles 2013for examiner\u2019s use4  a mixture of two solids, e and f, was analysed.   solid e was the water-soluble salt aluminium chloride, a l cl 3, and solid f was an insoluble  salt.   the tests on the mixture and some of the observations are in the following table.   complete the observations in the table. tests observations distilled water was added to the mixture in a  boiling tube.the contents of the boiling tube were shaken and \ufb01 ltered, keeping the \ufb01 ltrate and residue for  the following tests. tests on the \ufb01 ltrate the \ufb01 ltrate was divided into \ufb01 ve portions in  \ufb01 ve test-tubes. (a)  the \ufb01 rst portion was used to describe the  appearance of the \ufb01 ltrate.  appearance  [1] (b)  several drops of aqueous sodium  hydroxide were added to the second portion of the solution.   excess aqueous sodium hydroxide was  then added to the test-tube. ...   [3] (c)  aqueous ammonia was added to the third  portion, dropwise and then in excess. ...   [2] (d)  to the fourth portion of the solution, dilute  nitric acid and aqueous silver nitrate were added.   [2] (e)  to the \ufb01 fth portion of the solution, about  1  cm3 of dilute nitric acid and barium  nitrate solution were added.   [1]",
            "9": "9 0620/61/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s usetests observations tests on the residue (f) (i)  to a little of the residue, dilute hydrochloric acid was added.    the gas given off was tested.  (ii)  the residue was heated, gently then  strongly.rapid effervescence gas turned limewater milky solid changed colour from green to black  (g)  what conclusions can you draw about solid f?   ...    ... ..  [2] [total: 11]",
            "10": "10 0620/61/m/j/13 \u00a9 ucles 2013for examiner\u2019s use5  identical pieces of steel were placed in two different boiling liquids for 12 hours.   the graphs show how the mass of each piece of steel changed. 0 2 4 6 8 10 12200 150100 50 0mass loss  / mggraph a steel in boiling acid solution time  / hours0 2 4 6 8 10 120.20 0.150.100.05 0mass loss  / mggraph b steel in boiling alkali solution time  / hours  (a)  give one similarity in the change in mass of the steel in both liquids.   ... ..  [1]  (b)  describe two ways in which the mass loss shown in graph a is different from that shown  in graph b.  1.  ...    ...   2.  ...    ... ..  [3]  (c)  state two different safety precautions that would need to be taken when carrying out this  investigation.  1.  ...   2.  ... ..  [2] [total: 6]",
            "11": "11 0620/61/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use6  copper( ii) oxide and carbon are both black solids. copper( ii) oxide reacts with dilute sulfuric  acid to form aqueous copper( ii) sulfate. carbon does not react with dilute sulfuric acid.   you are given a mixture of copper( ii) oxide and carbon and access to dilute sulfuric acid.   plan an experiment to investigate the percentage of copper( ii) oxide in the mixture.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [6] [total: 6]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/61/m/j/13blank page \u00a9 ucles 2013"
        },
        "0620_s13_qp_62.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical may/june 2013  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib13 06_0620_62/rp\u00a9 ucles 2013 *2436679162*",
            "2": "2 0620/62/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  a student extracted the colours present in some leaves using the apparatus below.  (a)  complete the boxes to identify the pieces of apparatus used. [2]  (b)  use labelled arrows to indicate  (i)  the solvent,  (ii)  the solution of colours. [2]  (c)  chromatography was used to separate the colours. the chromatogram obtained is  shown.  (i)  on the diagram, label the solvent front. [1]  (ii)  how many colours were present?   . .  [1] [total: 6]",
            "3": "3 0620/62/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  a student investigated the reaction of methane, ch4, and copper( ii) oxide. she passed  methane gas over hot copper( ii) oxide using the apparatus shown. excess methane burning methane heatcopper( ii) oxide   the solid changed colour to red-brown and drops of liquid condensed in the cold part of the tube.  (a)  what was the original colour of the solid?   ... ..  [1]  (b)  suggest the identity of  (i)  the red-brown solid,  ...  (ii)  the drops of liquid.  ...  [2]  (c)  suggest a physical test to identify the liquid.  test     result  .. .  [2] [total: 5]",
            "4": "4 0620/62/m/j/13 \u00a9 ucles 2013for examiner\u2019s use3  a student investigated the reaction between a solution of deep purple aqueous potassium  manganate( vii), and two different colourless solutions, b and c, of an acidic solution of a  sodium salt.  two experiments were carried out.  experiment 1   a burette was \ufb01 lled with the solution of potassium manganate( vii) to the 0.0  cm3 mark.   using a measuring cylinder, 25  cm3 of solution b was poured into the conical \ufb02 ask.   the potassium manganate( vii) solution was added slowly to the \ufb02 ask and shaken to mix  thoroughly. addition of the solution was continued until there was a permanent pink colour in  the contents of the \ufb02 ask.  (a)  use the burette diagram to record the volume in the table of results and complete the table. 25 26 27 final reading \ufb01 nal reading  / cm3 initial reading  / cm3 difference  / cm3 [2]  experiment 2   experiment 1 was repeated using solution c instead of solution b.  (b)  use the burette diagrams to record the volumes in the table and complete the table. 31 32 33 initial reading18 19 20 final reading \ufb01 nal reading  / cm3 initial reading  / cm3 difference  / cm3 [2]",
            "5": "5 0620/62/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c) (i)  what colour change was observed in the contents of the \ufb02 ask when potassium  manganate( vii) solution was added to the \ufb02 ask in experiment 1?  from ...  to   [1]  (ii)  why was an indicator not added to the \ufb02 ask?   . .  [1]  (d) (i)  in which experiment was the greater volume of potassium manganate( vii) solution  used?   . .  [1]  (ii)  compare the volumes of potassium manganate( vii) solution used in experiments 1  and 2.   . .  [1]  (iii)  suggest an explanation for the difference in volumes in (d)(ii) .   . ...   . ...   . .  [2]  (e)  if experiment 2 was repeated using 12.5  cm3 of solution c, what volume of potassium  manganate( vii) solution would be used? explain your answer.   ...    ...    ... ..  [3]  (f)  a redox reaction occurs when potassium manganate( vii) reacts with solutions b and c.  explain the term redox reaction .   ...    ... ..  [2]  (g)  give one advantage and one disadvantage of using a measuring cylinder for solution c.  advantage  ... ..  disadvantage  ..  [2] [total: 17]",
            "6": "6 0620/62/m/j/13 \u00a9 ucles 2013for examiner\u2019s use4  a mixture of two solids, r and s, was analysed.   solid r was the water-soluble salt aluminium sulfate, a l 2(so4)3, and solid s was an insoluble  salt.   the tests on the mixture and some of the observations are in the following table.   complete the observations in the table. tests observations distilled water was added to the mixture in a  boiling tube.the boiling tube was shaken and the contents of the boiling tube \ufb01 ltered, keeping the \ufb01 ltrate  and residue for the following tests. the \ufb01 ltrate  was divided into \ufb01 ve test-tubes. tests on the \ufb01 ltrate (a)  appearance of the \ufb01 rst portion of the  \ufb01 ltrate.   [1] (b)  drops of aqueous sodium hydroxide were added to the second portion of the solution and the test-tube shaken.   excess aqueous sodium hydroxide was then added to the test-tube. ...   [3] (c)  aqueous ammonia was added to the third  portion, dropwise and then in excess. ...   [2] (d)  dilute nitric acid was added to the fourth  portion of the solution followed by aqueous silver nitrate.   [1] (e)  dilute nitric acid was added to the \ufb01 fth  portion of the solution and then aqueous barium nitrate.   [2]",
            "7": "7 0620/62/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s usetests observations tests on the residue (f)  dilute hydrochloric acid was added to the  residue.   the gas given off was tested.   excess aqueous sodium hydroxide was added to the mixture in the test-tube.rapid effervescence limewater turned milky white precipitate, insoluble in excess  (g)  name the gas given off in test (f).   ... ..  [1]  (h)  what conclusions can you draw about solid s?   ... ..  [2] [total: 12]",
            "8": "8 0620/62/m/j/13 \u00a9 ucles 2013for examiner\u2019s use5  a student investigated the temperature changes when dilute nitric acid neutralised aqueous  potassium hydroxide. the instructions followed are listed below.  step 1 the solutions were left at room temperature for one hour. step 2  using a measuring cylinder, 20  cm3 of aqueous potassium hydroxide solution was  poured into a polystyrene cup and its temperature measured.  step 3  from a burette, 5.0  cm3 of nitric acid was added to the cup. the highest temperature  reached by the mixture was measured. a further 5.0  cm3 of nitric acid was added to  the mixture and the highest temperature measured. further 5.0  cm3 additions were  made until a total of 30.0  cm3 of nitric acid had been added.  (a)  use the thermometer diagrams to complete the temperatures in the table. volume of nitric acid added  / cm3thermometer diagramhighest temperature  reached  / \u00b0c 0.030 25 5.03025 10.04035 15.04540 20.04540 25.04035 30.04035 [3]",
            "9": "9 0620/62/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b)   plot the results on the grid. draw two intersecting straight lines through the points. 0 5 10 15 20 25 3050 40 30 20 10highest temperature reached  / \u00b0c total volume of nitric acid  / cm3 [4]  (c)  from your graph , work out the volume of nitric acid needed to completely neutralise the  20  cm3 of aqueous potassium hydroxide. using an arrow, show clearly on the grid  this  neutralisation point.   ... ..  [2]  (d)  what was the room temperature?   ... ..  [1]  (e)  why was a polystyrene cup used instead of a glass beaker?   ... ..  [1]",
            "10": "10 0620/62/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (f)  why does the temperature:  increase      ...   then decrease?  .. ...   ... ..  [2]  (g)  what type of chemical reaction is this neutralisation?   ... ..  [1] [total: 14]",
            "11": "11 0620/62/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use6  two metals, a and b, each react with dilute sulfuric acid to produce hydrogen.   plan an investigation to show which metal, a or b, is the more reactive metal. you may  include a diagram in your answer.   you are provided with:  \u25cf  standard laboratory equipment  \u25cf  powdered metals a and b  \u25cf  dilute sulfuric acid.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [6] [total: 6]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/62/m/j/13blank page \u00a9 ucles 2013"
        },
        "0620_s13_qp_63.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical may/june 2013  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib13 06_0620_63/2rp\u00a9 ucles 2013 *9962014292*",
            "2": "2 0620/63/m/j/13 \u00a9 ucles 2013for examiner\u2019s use1  a student passed dry hydrogen gas over heated copper( ii) oxide using the apparatus below.   he wanted to collect and measure the water formed in the reaction. icedry hydrogen  (a)  use labelled arrows to indicate where  (i)  the heat is applied,  (ii)  the water collects. [2]  (b)  the colour of the copper( ii) oxide changes from black to  ..  [1]  (c)  suggest why the hydrogen gas that was used had to be dry.   ... ..  [1]  (d)  describe a chemical test for water.  test     result  .. .  [2] [total: 6]",
            "3": "3 0620/63/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  electricity was passed through a solution of concentrated sodium chloride containing  universal indicator using the apparatus shown. solution of concentratedsodium chloridecontaininguniversal indicator   the bulb lit up. the solution near the negative electrode changed colour from green to purple.  (a)  give one other expected observation.   ... ..  [1]  (b)  name a suitable non-metallic element for the electrodes.   ... ..  [1]  (c)  name the process which uses electricity to break down solutions.   ... ..  [1]  (d) (i)   explain why the universal indicator changed colour.   . ...   . .  [2]  (ii)  predict the colour of the indicator near the positive electrode. explain your prediction.  colour  .. ...  explanation  ..  [2] [total: 7]",
            "4": "4 0620/63/m/j/13 \u00a9 ucles 2013for examiner\u2019s use3  a student investigated the reaction between potassium hydrogen carbonate, khco3, and two  aqueous solutions of dilute hydrochloric acid of different concentrations, labelled f and g.   two experiments were carried out.  (a)  experiment 1   using a measuring cylinder, 20  cm3 of distilled water was poured into a conical \ufb02 ask. a 0.3  g sample of potassium hydrogen carbonate was added to the \ufb02 ask and shaken to  dissolve the solid.   methyl orange indicator was added to the alkaline solution in the conical \ufb02 ask.   a burette was \ufb01 lled up to the 0.0  cm3 mark with the solution f of dilute hydrochloric acid.  acid f was added from the burette until the solution in the \ufb02 ask just changed colour.   use the burette diagram to record the \ufb01 nal reading in the table below and complete the  table for this experiment. 38 39 40 final reading  (b)  experiment 2   the conical \ufb02 ask was emptied and rinsed with distilled water.   the contents of the burette were poured away and the burette rinsed with distilled water  and then the solution g of dilute hydrochloric acid. experiment 1 was repeated using  solution g instead of solution f.   use the burette diagrams to record the readings in the table below and complete the table. 8 9 10 initial reading21 22 23 final reading burette readings  / cm3 experiment 1 experiment 2 \ufb01 nal reading initial reading difference [4]",
            "5": "5 0620/63/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)   what colour change was observed in the contents of the \ufb02 ask after the hydrochloric acid  was added to the \ufb02 ask?  from ...  to   ... [2]  (d)  what type of chemical reaction occurred when hydrochloric acid reacted with potassium hydrogen carbonate?   ... ..  [1]  (e)  complete the sentence below.   experiment  needed the smallest volume of hydrochloric acid to change the colour of the methyl orange. [1]  (f) (i)   compare the volumes of hydrochloric acid used in experiments 1 and 2.   . .  [1]  (ii)  the most concentrated solution of hydrochloric acid was solution  .  [1]  (g)  if experiment 2 was repeated using 0.6  g of potassium hydrogen carbonate, what volume  of hydrochloric acid would be needed?   ... ..  [2]  (h)  what would be a more accurate method of measuring the volume of the distilled water?   ... ..  [1]  (i)  why was the burette rinsed with distilled water and then the solution g of dilute  hydrochloric acid before starting experiment 2?   ...    ... ..  [2]  (j)  what would be the effect on the results if the solutions of potassium hydrogen carbonate were warmed before adding the hydrochloric acid? give a reason for your answer.  effect on results  ... .  reason  .  [2]",
            "6": "6 0620/63/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (k)   describe a different  method of \ufb01 nding out which of the solutions of hydrochloric acid, f  or g, is the more concentrated.   ...    ...    ...    ...    ... ..  [3] [total: 20]",
            "7": "7 0620/63/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use4  two solids, h and i, were analysed. h was the salt copper ethanoate, (ch3coo)2cu.   the tests on the solids and some of the observations are in the following table.  complete the observations in the table. tests observations tests on solid h solid h was added to distilled water in a test-tube and shaken to dissolve. the solution  was divided into three equal portions intest-tubes, and the following tests carried out. (a)  appearance of the solution. ...  [1] (b)  aqueous sodium hydroxide was added to  the second portion of the solution. ...  [2] (c)  drops of aqueous ammonia were added to the third portion of the solution.   excess aqueous ammonia was then added to the mixture  [2]  ...  [2] tests on solid i (d) (i)   solid i was heated in a dry test-tube.  the gas given off was tested with a  lighted splint.   the test-tube was left to cool.    dilute hydrochloric acid was then added to the test-tube. the gas given off was tested.  (ii)   solid i was added to dilute nitric acid in  a test-tube. the solution was warmed and the mixture smelled.solid turned black and charred the gas ignited effervescence limewater turned milky smell of vinegar  (e)  what conclusions can you draw about solid i?   ...    ... ..  [2] [total: 9]",
            "8": "8 0620/63/m/j/13 \u00a9 ucles 2013for examiner\u2019s use5  a student investigated the rate of reaction between magnesium and excess dilute hydrochloric  acid at room temperature. the apparatus was set up as shown in the diagram. watermeasuring cylinde rdilute hydrochloric acid magnesium   using a tap funnel, 20  cm3 of hydrochloric acid was added to 4  cm of magnesium ribbon. the  volume of hydrogen produced was measured every minute for six minutes.  (a)  use the measuring cylinder diagrams to record the volumes of gas collected in the table of results. time  / minmeasuring cylinder diagramtotal volume of gas collected  / cm3 0 12 3450 5 10 30 35 40 55 60 65 65 70 75 70 75 80 70 75 80 70 75 806 [2]",
            "9": "9 0620/63/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b)  plot the points on the grid and draw a smooth line graph. 0 1 2 3 4 5 6 time  / minutesvolume of hydrogen  / cm3 [4]  (c)  from your graph , \ufb01 nd the time at which 50  cm3 of gas was produced. show clearly on  the graph  how you obtained your answer.   ... ..  [2]  (d)  sketch on the grid  the graph you would expect if the experiment was repeated using  2 cm of magnesium ribbon. [2]",
            "10": "10 0620/63/m/j/13 \u00a9 ucles 2013for examiner\u2019s use (e)  explain why the rate of reaction would be lower if the hydrochloric acid was cooled to  5 \u00b0c before the reaction.   ...    ...    ... ..  [2] [total: 12]",
            "11": "11 0620/63/m/j/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use6  the table gives information about the solubility of three different solids, w, x and y, in two  different solvents. substancesolubility in cold watersolubility in hot watersolubility in  cyclohexane w insoluble insoluble very soluble x insoluble very soluble insoluble y very soluble very soluble insoluble   you are provided with a mixture of the three substances, w, x and y. plan a method which  could be used to separate pure dry samples of w, x and y from the mixture.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [6] [total: 6]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/63/m/j/13blank page \u00a9 ucles 2013"
        },
        "0620_w13_qp_11.pdf": {
            "1": "    this document consists of 18 printed pages and 2 blank pages.  ib13 11_0620_11/2rp  \u00a9 ucles 2013  [turn over       *6047676049* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  october/november 2013       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2013 0620/11/o/n/13  1 an attempt was made to compress a gas and a solid using the apparatus shown.    piston gas solid     which substance would be compressed and what is the reason for this?     substance reason  a gas the gas particles are close together  b gas the gas particles are far apart  c solid the solid particles are close together  d solid the solid particles are far apart      2 a student measures the rate of two reactions.    in one reaction, there is a change in ma ss of the reactants during the reaction.    in the second reaction, there is a change in temperature during the reaction.    which piece of apparatus would be essential in both  experiments?  a balance  b clock  c pipette  d thermometer     ",
            "3": "3  \u00a9 ucles 2013 0620/11/o/n/13 [turn over  3 diagram 1 shows the paper chromatogram of substance x.    r y x  diagram 1     diagram 2 shows the cooling curve for substance y.    0 147  0 temperature  / \u00b0c time  diagram 2     which statement about x and y is correct?  a x is a mixture and y is a pure substance.  b x is a pure substance and y is a mixture.  c x and y are mixtures.  d x and y are pure substances.     ",
            "4": "4  \u00a9 ucles 2013 0620/11/o/n/13  4 element x has 7 protons.    element y has 8 more protons than x.    which statement about element y is correct?  a y has more electron shells than x.  b y has more electrons in its outer shell than x.  c y is in a different group of the periodic table from x.  d y is in the same period of the periodic table as x      5 which statements about a sodium atom, na,23 11  are correct?    1 the number of protons and neutrons is the same.  2 the number of protons and electrons is the same. 3 the number of outer electrons is one.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     6 rubidium is in group i of the periodic table and bromine is in group vii.    rubidium reacts with bromine to form an ionic compound.    which row shows the electron change taking place for rubidium and the correct formula of the  rubidium ion?     electron change formula of ion formed  a electron gained rb+  b electron gained rb\u2013  c electron lost rb+  d electron lost rb\u2013    7 the diagrams show the electron arrangements in the atoms of four elements.    which element does not form a covalent bond?    e e e e e e e  e e e e  e e e  e  e e e e key  electron  nucleus a b c d  e e e e  e e  e e      ",
            "5": "5  \u00a9 ucles 2013 0620/11/o/n/13 [turn over  8 a solid mixture contains an ionic salt, x, and a covalent organic compound, y.    two students suggest methods of separating the mixture as shown.    method 1 method 2shake with water x + y shake with ethanol x + y    which methods of separation are likely to work?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     9 the formulae of compounds w, x and y are shown.    w cuso 4.5h 2o  x mgso 4.7h 2o  y cu(no 3)2.6h 2o    which statement is correct?  a w contains twice as many hydrogen atoms as oxygen atoms.  b x contains the most oxygen atoms.  c y contains the most hydrogen atoms.  d y contains the same number of hydrogen and oxygen atoms.     ",
            "6": "6  \u00a9 ucles 2013 0620/11/o/n/13  10 which relative molecular mass, mr, is not correct for the molecule given?     molecule mr  a ammonia, nh 3 17  b carbon dioxide, co 2 44  c methane, ch 4 16  d oxygen, o 2 16      11 the diagram shows the circuit for electrolysing lead( ii) bromide and sodium chloride to liberate  the metal.    a container for lead(ii) bromidecontainer for sodium chloride    in what form are these salts electrolysed for liberating the metal?     lead( ii) bromide sodium chloride  a concentrated solution concentrated solution  b concentrated solution molten  c molten concentrated solution  d molten molten     ",
            "7": "7  \u00a9 ucles 2013 0620/11/o/n/13 [turn over  12 the diagram shows the electrolysis of concentrated aqueous sodium chloride.    +\u2013anode cathode concentrated aqueous sodiumchloride and litmuscarbon rods     what is the colour of the litmus at each electrode after five minutes?     colour at anode colour at cathode  a blue red  b red blue  c red colourless  d colourless blue      13 when anhydrous copper( ii) sulfate is added to water a solution is formed and heat is given out.    wateranhydrous copper( ii) sulfatethermometer     which row correctly shows the temperature change and the type of reaction taking place?     temperature change type of reaction  a decreases endothermic  b decreases exothermic  c increases endothermic  d increases exothermic   ",
            "8": "8  \u00a9 ucles 2013 0620/11/o/n/13  14 which fuel does not produce carbon dioxide when it burns?  a coal  b hydrogen  c methane  d petrol      15 a student investigates the rate of reaction between zinc and an excess of sulfuric acid.    the graph shows the results of two experiments, x and y.    0xy time0volume of hydrogen     which change explains the difference between x and y?  a a catalyst is added in y.  b a lower temperature is used in y.  c larger pieces of zinc are used in y.  d less concentrated acid is used in y.      16 anhydrous copper( ii) sulfate can be made by heating hydrated copper( ii) sulfate.    cuso 4.5h 2o  \u2192  cuso 4  +  5h 2o    what can be added to anhydrous copper( ii) sulfate to turn it into hydrated copper( ii) sulfate?  a concentrated sulfuric acid  b sodium hydroxide powder  c sulfur dioxide  d water     ",
            "9": "9  \u00a9 ucles 2013 0620/11/o/n/13 [turn over  17 the reactions shown may occur in the air during a thunder storm.    n2  +  o 2  \u2192  2no  2no  +  o 2  \u2192  2no 2  no  +  o 3  \u2192  no 2  +  o 2    which row shows what happens to the reactant molecules in each of these reactions?     n2 no o 3  a oxidised oxidised oxidised  b oxidised oxidised reduced  c reduced reduced oxidised  d reduced reduced reduced      18 which are properties of an acid?    1 reacts with ammonium sulfate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     19 which of the following are properties of the oxides of non-metals?     property 1 property 2  a acidic covalent  b acidic ionic  c basic covalent  d basic ionic     ",
            "10": "10  \u00a9 ucles 2013 0620/11/o/n/13  20 compound x is tested and the results are shown in the table.    test result  aqueous sodium hydroxide is  added, then heated gently gas given off which turns damp  red litmus paper blue  dilute hydrochloric acid is added effervescence, gas given off  which turns limewater milky    which ions are present in compound x?  a ammonium ions and carbonate ions  b ammonium ions and chloride ions  c calcium ions and carbonate ions  d calcium ions and chloride ions     21 calcium, on the left of period 4 of the periodic table, is more metallic than bromine on the right of  this period.    why is this?    calcium has  a fewer electrons.  b fewer protons.  c fewer full shells of electrons.  d fewer outer shell electrons.      22 the diagrams show the labels of four bottles.    which label is not correct?    a  b  c  d  bromine  br 2    harmful liquid.  do not spill.  iodine  i2    danger  avoid breathing vapour  from the solid.  potassium  k    danger  store under water.  sodium  na    danger  store under oil.     ",
            "11": "11  \u00a9 ucles 2013 0620/11/o/n/13 [turn over  23 an element has a melting point of 1084  \u00b0c and a density of 8.93  g / cm3. it\u2019s oxide can be used as  a catalyst.    in which position in the periodic table is the element found?    a bc d     24 the diagram shows a light bulb.    filament argon     why is argon used instead of air in the light bulb?  a argon is a good conductor of electricity.  b argon is more reactive than air.  c the filament glows more brightly.  d the filament does not react with the argon.     25 some properties of four elements w, x, y and z are listed.    1 w melts at 1410  \u00b0c and forms an acidic oxide.  2 x has a high density and is easily drawn into wires.  3 y acts as a catalyst and its oxide reacts with acids. 4 z is a red-brown solid used to make alloys.    which of the elements are metals?  a 1 and 3 b 2, 3 and 4 c 2 and 3 only d 2 and 4 only     ",
            "12": "12  \u00a9 ucles 2013 0620/11/o/n/13  26 m is a shiny silver metal. it has a melting point of 1455  \u00b0c. many of its compounds are green.    what is metal m?  a aluminium  b copper  c mercury  d nickel     27 reactions of three metals and their oxides are listed in the table.    metal reacts with   cold water metal oxide reacts  with carbon  w no no  x no yes  y yes no    what is the order of reactivity of the metals?     least reactive  most reactive  a w x y  b x w y  c x y w  d y w x    28 equations p and q represent two reactions which occur inside a blast furnace.    p fe 2o3  +  3co  \u2192  2fe  +  3co 2  q caco 3  \u2192  cao  +  co 2    which type of reactions are p and q?     p q  a redox redox  b redox thermal decomposition  c thermal decomposition redox  d thermal decomposition thermal decomposition     ",
            "13": "13  \u00a9 ucles 2013 0620/11/o/n/13 [turn over  29 which row describes the uses of mild steel and stainless steel?     mild steel stainless steel  a car bodies, cutlery chemical plant, machinery  b car bodies, machinery chemical plant, cutlery  c chemical plant, cutlery car bodies, machinery  d chemical plant, machinery car bodies, cutlery     30 in which process is carbon dioxide not formed?  a burning of natural gas  b fermentation  c heating lime  d respiration    31 farmers add calcium oxide (lime) and ammonium salts to their fields.    the compounds are not added at the same time because they react with each other.    which gas is produced in this reaction?  a ammonia  b carbon dioxide  c hydrogen  d nitrogen     32 the diagrams show four uses of iron.    in which of these uses is the iron most likely to rust?    iron bucket electroplated with zinca iron cored aluminium electricity cablesb iron hinges on a gatec painted iron fenced      ",
            "14": "14  \u00a9 ucles 2013 0620/11/o/n/13  33 which air pollutant is not made when coal burns in a power station?  a carbon monoxide  b lead compounds  c nitrogen oxides  d sulfur dioxide      34 in many countries river water is used for the washing of clothes.    the same water is not considered to be safe for drinking.    why is it not safe for drinking?  a because river water contains dissolved salts  b because river water may contain harmful bacteria  c because river water may contain small particles of sand  d because river water may contain soap from washing clothes     35 the diagram shows a kiln used to heat limestone.    gas burners productairwaste gaseslimestone     what is the product and what waste gas is formed?     product waste gas  a lime, cao carbon monoxide  b lime, cao carbon dioxide  c slaked lime, ca(oh) 2 carbon monoxide  d slaked lime, ca(oh) 2 carbon dioxide ",
            "15": "15  \u00a9 ucles 2013 0620/11/o/n/13 [turn over  36 three types of organic compound are alkanes, alkenes and alcohols.    which structure does not belong to any of these three types of compound?    hch hchh c oo hh chh chh chh ohhchh h cchhh h ch hab cdch hch h      37 the diagram shows some properties of two organic compounds x and y.    reacts with bromine polymerisesxused as a fuel used as a solventysteam and a catalyst     what are x and y?     x y  a ethane ethanoic acid  b ethane ethanol  c ethene ethanoic acid  d ethene ethanol    ",
            "16": "16  \u00a9 ucles 2013 0620/11/o/n/13  38 petroleum is a mixture of hydrocarbons which can be separated into fractions using fractional  distillation.    which fraction is used as fuel in jet engines?  a bitumen  b gasoline  c kerosene  d naphtha     39 the diagram represents ethene.    c ch hhh     which compound has chemical properties similar to those of ethene?    c c h hh hha hc c h hhhhb hchh c c hhhhd chh c c h hhhc ohh      ",
            "17": "17  \u00a9 ucles 2013 0620/11/o/n/13  40 a chemist carried out a cracking reaction on a hydrocarbon, x, and obtained two products, y   and z.    h c hh c hhc hhc hhhh c hhch c hh+ x yz     the chemist then wrote the following statements in his notebook.    1 a molecule of x has 7 carbon atoms.  2 y is unsaturated.  3 z will decolourise bromine water.    which statements are correct?  a 3 only b 1 and 2 c 1 and 3 d 1, 2 and 3     ",
            "18": "18  \u00a9 ucles 2013 0620/11/o/n/13  blank page ",
            "19": "19  \u00a9 ucles 2013 0620/11/o/n/13  blank page",
            "20": "20      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2013 0620/11/o/n/13   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w13_qp_12.pdf": {
            "1": "    this document consists of 18 printed pages and 2 blank pages.  ib13 11_0620_12/fp  \u00a9 ucles 2013  [turn over       *9656669434* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  october/november 2013       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2013 0620/12/o/n/13  1 an attempt was made to compress a gas and a solid using the apparatus shown.    piston gas solid     which substance would be compressed and what is the reason for this?     substance reason  a gas the gas particles are close together  b gas the gas particles are far apart  c solid the solid particles are close together  d solid the solid particles are far apart      2 a student measures the rate of two reactions.    in one reaction, there is a change in ma ss of the reactants during the reaction.    in the second reaction, there is a change in temperature during the reaction.    which piece of apparatus would be essential in both  experiments?  a balance  b clock  c pipette  d thermometer     ",
            "3": "3  \u00a9 ucles 2013 0620/12/o/n/13 [turn over  3 diagram 1 shows the paper chromatogram of substance x.    r y x  diagram 1     diagram 2 shows the cooling curve for substance y.    0 147  0 temperature  / \u00b0c time  diagram 2     which statement about x and y is correct?  a x is a mixture and y is a pure substance.  b x is a pure substance and y is a mixture.  c x and y are mixtures.  d x and y are pure substances.      4 which statements about a sodium atom, na,23 11  are correct?    1 the number of protons and neutrons is the same.  2 the number of protons and electrons is the same.  3 the number of outer electrons is one.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "4": "4  \u00a9 ucles 2013 0620/12/o/n/13  5 the diagrams show the electron arrangements in the atoms of four elements.    which element does not form a covalent bond?    e e e e e e e  e e e e  e e e  e  e e e e key  electron  nucleus a b c d  e e e e  e e  e e      6 rubidium is in group i of the periodic table and bromine is in group vii.    rubidium reacts with bromine to form an ionic compound.    which row shows the electron change taking place for rubidium and the correct formula of the  rubidium ion?     electron change formula of ion formed  a electron gained rb+  b electron gained rb\u2013  c electron lost rb+  d electron lost rb\u2013    7 element x has 7 protons.    element y has 8 more protons than x.    which statement about element y is correct?  a y has more electron shells than x.  b y has more electrons in its outer shell than x.  c y is in a different group of the periodic table from x.  d y is in the same period of the periodic table as x    ",
            "5": "5  \u00a9 ucles 2013 0620/12/o/n/13 [turn over  8 the formulae of compounds w, x and y are shown.    w cuso 4.5h 2o  x mgso 4.7h 2o  y cu(no 3)2.6h 2o    which statement is correct?  a w contains twice as many hydrogen atoms as oxygen atoms.  b x contains the most oxygen atoms.  c y contains the most hydrogen atoms.  d y contains the same number of hydrogen and oxygen atoms.     9 a solid mixture contains an ionic salt, x, and a covalent organic compound, y.    two students suggest methods of separating the mixture as shown.    method 1 method 2shake with water x + y shake with ethanol x + y    which methods of separation are likely to work?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "6": "6  \u00a9 ucles 2013 0620/12/o/n/13  10 the diagram shows the circuit for electrolysing lead( ii) bromide and sodium chloride to liberate  the metal.    a container for lead(ii) bromidecontainer for sodium chloride    in what form are these salts electrolysed for liberating the metal?     lead( ii) bromide sodium chloride  a concentrated solution concentrated solution  b concentrated solution molten  c molten concentrated solution  d molten molten      11 which relative molecular mass, mr, is not correct for the molecule given?     molecule mr  a ammonia, nh 3 17  b carbon dioxide, co 2 44  c methane, ch 4 16  d oxygen, o 2 16     ",
            "7": "7  \u00a9 ucles 2013 0620/12/o/n/13 [turn over  12 when anhydrous copper( ii) sulfate is added to water a solution is formed and heat is given out.    wateranhydrous copper( ii) sulfatethermometer     which row correctly shows the temperature change and the type of reaction taking place?     temperature change type of reaction  a decreases endothermic  b decreases exothermic  c increases endothermic  d increases exothermic     13 the diagram shows the electrolysis of concentrated aqueous sodium chloride.    +\u2013anode cathode concentrated aqueous sodiumchloride and litmuscarbon rods     what is the colour of the litmus at each electrode after five minutes?     colour at anode colour at cathode  a blue red  b red blue  c red colourless  d colourless blue   ",
            "8": "8  \u00a9 ucles 2013 0620/12/o/n/13  14 anhydrous copper( ii) sulfate can be made by heating hydrated copper( ii) sulfate.    cuso 4.5h 2o  \u2192  cuso 4  +  5h 2o    what can be added to anhydrous copper( ii) sulfate to turn it into hydrated copper( ii) sulfate?  a concentrated sulfuric acid  b sodium hydroxide powder  c sulfur dioxide  d water      15 which fuel does not produce carbon dioxide when it burns?  a coal  b hydrogen  c methane  d petrol    16 a student investigates the rate of reaction between zinc and an excess of sulfuric acid.    the graph shows the results of two experiments, x and y.    0xy time0volume of hydrogen     which change explains the difference between x and y?  a a catalyst is added in y.  b a lower temperature is used in y.  c larger pieces of zinc are used in y.  d less concentrated acid is used in y.     ",
            "9": "9  \u00a9 ucles 2013 0620/12/o/n/13 [turn over  17 which are properties of an acid?    1 reacts with ammonium sulfate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     18 which of the following are properties of the oxides of non-metals?     property 1 property 2  a acidic covalent  b acidic ionic  c basic covalent  d basic ionic     19 the reactions shown may occur in the air during a thunder storm.    n 2  +  o 2  \u2192  2no  2no  +  o 2  \u2192  2no 2  no  +  o 3  \u2192  no 2  +  o 2    which row shows what happens to the reactant molecules in each of these reactions?     n2 no o 3  a oxidised oxidised oxidised  b oxidised oxidised reduced  c reduced reduced oxidised  d reduced reduced reduced    ",
            "10": "10  \u00a9 ucles 2013 0620/12/o/n/13  20 calcium, on the left of period 4 of the periodic table, is more metallic than bromine on the right of  this period.    why is this?    calcium has  a fewer electrons.  b fewer protons.  c fewer full shells of electrons.  d fewer outer shell electrons.      21 compound x is tested and the results are shown in the table.    test result  aqueous sodium hydroxide is  added, then heated gently gas given off which turns damp  red litmus paper blue  dilute hydrochloric acid is added effervescence, gas given off  which turns limewater milky    which ions are present in compound x?  a ammonium ions and carbonate ions  b ammonium ions and chloride ions  c calcium ions and carbonate ions  d calcium ions and chloride ions      22 some properties of four elements w, x, y and z are listed.    1 w melts at 1410  \u00b0c and forms an acidic oxide.  2 x has a high density and is easily drawn into wires.  3 y acts as a catalyst and its oxide reacts with acids. 4 z is a red-brown solid used to make alloys.    which of the elements are metals?  a 1 and 3 b 2, 3 and 4 c 2 and 3 only d 2 and 4 only     ",
            "11": "11  \u00a9 ucles 2013 0620/12/o/n/13 [turn over  23 the diagram shows a light bulb.    filament argon     why is argon used instead of air in the light bulb?  a argon is a good conductor of electricity.  b argon is more reactive than air.  c the filament glows more brightly.  d the filament does not react with the argon.      24 an element has a melting point of 1084  \u00b0c and a density of 8.93  g / cm3. it\u2019s oxide can be used as  a catalyst.    in which position in the periodic table is the element found?    a bc d     25 the diagrams show the labels of four bottles.    which label is not correct?    a  b  c  d  bromine  br 2    harmful liquid.  do not spill.  iodine  i2    danger  avoid breathing vapour  from the solid.  potassium  k    danger  store under water.  sodium  na    danger  store under oil.     ",
            "12": "12  \u00a9 ucles 2013 0620/12/o/n/13  26 equations p and q represent two reactions which occur inside a blast furnace.    p fe 2o3  +  3co  \u2192  2fe  +  3co 2  q caco 3  \u2192  cao  +  co 2    which type of reactions are p and q?     p q  a redox redox  b redox thermal decomposition  c thermal decomposition redox  d thermal decomposition thermal decomposition     27 farmers add calcium oxide (lime) and ammonium salts to their fields.    the compounds are not added at the same time because they react with each other.    which gas is produced in this reaction?  a ammonia  b carbon dioxide  c hydrogen  d nitrogen    28 which row describes the uses of mild steel and stainless steel?     mild steel stainless steel  a car bodies, cutlery chemical plant, machinery  b car bodies, machinery chemical plant, cutlery  c chemical plant, cutlery car bodies, machinery  d chemical plant, machinery car bodies, cutlery    ",
            "13": "13  \u00a9 ucles 2013 0620/12/o/n/13 [turn over  29 reactions of three metals and their oxides are listed in the table.    metal reacts with   cold water metal oxide reacts  with carbon  w no no  x no yes  y yes no    what is the order of reactivity of the metals?     least reactive  most reactive  a w x y  b x w y  c x y w  d y w x     30 the diagrams show four uses of iron.    in which of these uses is the iron most likely to rust?    iron bucket electroplated with zinca iron cored aluminium electricity cablesb iron hinges on a gatec painted iron fenced      31 in which process is carbon dioxide not formed?  a burning of natural gas  b fermentation  c heating lime  d respiration    ",
            "14": "14  \u00a9 ucles 2013 0620/12/o/n/13  32 m is a shiny silver metal. it has a melting point of 1455  \u00b0c. many of its compounds are green.    what is metal m?  a aluminium  b copper  c mercury  d nickel     33 in many countries river water is used for the washing of clothes.    the same water is not considered to be safe for drinking.    why is it not safe for drinking?  a because river water contains dissolved salts  b because river water may contain harmful bacteria  c because river water may contain small particles of sand  d because river water may contain soap from washing clothes    ",
            "15": "15  \u00a9 ucles 2013 0620/12/o/n/13 [turn over  34 the diagram shows a kiln used to heat limestone.    gas burners productairwaste gaseslimestone     what is the product and what waste gas is formed?     product waste gas  a lime, cao carbon monoxide  b lime, cao carbon dioxide  c slaked lime, ca(oh) 2 carbon monoxide  d slaked lime, ca(oh) 2 carbon dioxide     35 which air pollutant is not made when coal burns in a power station?  a carbon monoxide  b lead compounds  c nitrogen oxides  d sulfur dioxide    ",
            "16": "16  \u00a9 ucles 2013 0620/12/o/n/13  36 the diagram shows some properties of two organic compounds x and y.    reacts with bromine polymerisesxused as a fuel used as a solventysteam and a catalyst     what are x and y?     x y  a ethane ethanoic acid  b ethane ethanol  c ethene ethanoic acid  d ethene ethanol      37 three types of organic compound are alkanes, alkenes and alcohols.    which structure does not belong to any of these three types of compound?    hch hchh c oo hh chh chh chh ohhchh h cchhh h ch hab cdch hch h      ",
            "17": "17  \u00a9 ucles 2013 0620/12/o/n/13  38 the diagram represents ethene.    c ch hhh     which compound has chemical properties similar to those of ethene?    c c h hh hha hc c h hhhhb hchh c c hhhhd chh c c h hhhc ohh       39 petroleum is a mixture of hydrocarbons which can be separated into fractions using fractional  distillation.    which fraction is used as fuel in jet engines?  a bitumen  b gasoline  c kerosene  d naphtha     40 a chemist carried out a cracking reaction on a hydrocarbon, x, and obtained two products, y   and z.    h c hh c hhc hhc hhhh c hhch c hh+ x yz     the chemist then wrote the following statements in his notebook.    1 a molecule of x has 7 carbon atoms.  2 y is unsaturated.  3 z will decolourise bromine water.    which statements are correct?  a 3 only b 1 and 2 c 1 and 3 d 1, 2 and 3     ",
            "18": "18  \u00a9 ucles 2013 0620/12/o/n/13  blank page ",
            "19": "19  \u00a9 ucles 2013 0620/12/o/n/13  blank page",
            "20": "20      permission to reproduce items where thir d-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2013 0620/12/o/n/13   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w13_qp_13.pdf": {
            "1": "    this document consists of 19 printed pages and 1 blank page.  ib13 11_0620_13/rp  \u00a9 ucles 2013  [turn over       *5450428188* university of cambridge international examinations  international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  october/november 2013       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, highlighters, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2013 0620/13/o/n/13  1 a gas jar of bromine vapour and a gas jar of air are set up as shown in diagram 1.    the glass slide is removed. diagram 2 shows the appearance of the gas jars after one hour.    diagram 1 diagram 2bromine vapourmixture of ai r and bromineair glass slide     which statement explains why the bromine and air mix together?  a bromine is denser than air.  b bromine is lighter than air.  c bromine molecules moved upwards and molecules in air moved downwards.  d molecules in bromine and air moved randomly.     2 the diagram shows a method for separating a substance that contains x and y.    filter paper x y     which types of substance can be separated as shown?  a compounds  b elements  c mixtures  d molecules     ",
            "3": "3  \u00a9 ucles 2013 0620/13/o/n/13 [turn over  3 diagram 1 shows the paper chromatogram of substance x.    r y x  diagram 1     diagram 2 shows the cooling curve for substance y.    0 147  0 temperature  / \u00b0c time  diagram 2     which statement about x and y is correct?  a x is a mixture and y is a pure substance.  b x is a pure substance and y is a mixture.  c x and y are mixtures.  d x and y are pure substances.     ",
            "4": "4  \u00a9 ucles 2013 0620/13/o/n/13  4 the atomic structures of four atoms are shown.    atom number of  neutrons number of  protons number of  electrons  w 6 6 6  x 7 7 7  y 8 6 6  z 8 8 8    which pair of atoms are isotopes?  a w and x b w and y c x and y d y and z     5 the diagram shows the structure of three particles, r, s and t.    3 p 3 nkey = electron = neutron= proton = nucleuseee e n p r3 p 3 nee s3 p4 neee t    which row describes these particles?     ions isotopes  a r s and t  b r and s t  c s r and t  d t r and s      6 which statement about the bonding in a molecule of water is not correct?  a both hydrogen and oxygen have a noble gas configuration of electrons.  b each hydrogen shares its one electron with oxygen.  c oxygen shares one of its own electrons with each hydrogen.  d oxygen shares two of its own electrons with each hydrogen.    ",
            "5": "5  \u00a9 ucles 2013 0620/13/o/n/13 [turn over  7 the electronic structures of atoms p and q are shown.    pq     p and q react to form an ionic compound.    what is the formula of the compound?  a q7p b qp c qp 3 d qp 7      8 a solid mixture contains an ionic salt, x, and a covalent organic compound, y.    two students suggest methods of separating the mixture as shown.    method 1 method 2shake with water x + y shake with ethanol x + y    which methods of separation are likely to work?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "6": "6  \u00a9 ucles 2013 0620/13/o/n/13  9 which relative molecular mass, mr, is not correct for the molecule given?     molecule mr  a ammonia, nh 3 17  b carbon dioxide, co 2 44  c methane, ch 4 16  d oxygen, o 2 16     10 two electrolysis experiments were carried out as shown in the diagram below.    the graphite electrodes are labelled 1-4.    molten  sodium chloride12 34 concentrated aqueous sodium chloride++ \u2013\u2013     which row describes the products at the electrodes in these experiments?     electrode 1 electrode 2 electrode 3 electrode 4  a chlorine hydrogen chlorine hydrogen  b chlorine sodium chlorine hydrogen  c chlorine sodium hydrogen chlorine  d sodium chlorine sodium chlorine     ",
            "7": "7  \u00a9 ucles 2013 0620/13/o/n/13 [turn over  11 one molten compound and two aqueous solutions were electrolysed.    the table gives the compounds electrolysed and the electrodes used.     substance electrolysed electrodes  1 concentrated hydrochloric acid carbon  2 concentrated sodium chloride platinum  3 molten lead bromide platinum    in which experiments is a gas evolved at the cathode?  a 1, 2 and 3 b 1 and 2 only c 1 only d 3 only      12 when ammonium nitrate is added to water the temperature of the water decreases.    the ammonium nitrate can be recovered by evaporating the water added.    which explains these observations?  a the ammonium nitrate dissolves in the water and the process is endothermic.  b the ammonium nitrate reacts with the water and the process is endothermic.  c the ammonium nitrate dissolves in the water and the process is exothermic.  d the ammonium nitrate reacts with the water and the process is exothermic.     13 which substance could not be used as a fuel to heat water in a boiler?  a ethanol  b hydrogen  c methane  d oxygen      14 which substance is not a fossil fuel?  a coal b kerosene c gasoline d wood    ",
            "8": "8  \u00a9 ucles 2013 0620/13/o/n/13  15 a student investigates the rate of reaction between zinc and an excess of sulfuric acid.    the graph shows the results of two experiments, x and y.    0xy time0volume of hydrogen     which change explains the difference between x and y?  a a catalyst is added in y.  b a lower temperature is used in y.  c larger pieces of zinc are used in y.  d less concentrated acid is used in y.      16 when green iron( ii) sulfate is heated, it turns white and a colourless liquid is produced.    when the liquid is put back into the white solid it changes back to green.    what type of reaction takes place and what is the name of the liquid?   type of reaction name of liquid  a redox sulfuric acid  b redox water  c reversible sulfuric acid  d reversible water     ",
            "9": "9  \u00a9 ucles 2013 0620/13/o/n/13 [turn over  17 the reactions shown may occur in the air during a thunder storm.    n2  +  o 2  \u2192  2no  2no  +  o 2  \u2192  2no 2  no  +  o 3  \u2192  no 2  +  o 2    which row shows what happens to the reactant molecules in each of these reactions?     n2 no o 3  a oxidised oxidised oxidised  b oxidised oxidised reduced  c reduced reduced oxidised  d reduced reduced reduced      18 which are properties of an acid?    1 reacts with ammonium sulfate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     19 which of the following are properties of the oxides of non-metals?     property 1 property 2  a acidic covalent  b acidic ionic  c basic covalent  d basic ionic     ",
            "10": "10  \u00a9 ucles 2013 0620/13/o/n/13  20 the cations shown are identified by the colour of the precipitates formed when an excess of an  aqueous solution of x is added.    cations present effect of adding an excess of  aqueous x  iron( ii) (fe2+) green precipitate  copper( ii) (cu2+) light blue precipitate  iron( iii) (fe3+) red-brown precipitate    what is x?  a ammonia  b limewater  c silver nitrate  d sodium hydroxide      21 calcium, on the left of period 4 of the periodic table, is more metallic than bromine on the right of  this period.    why is this?    calcium has  a fewer electrons.  b fewer protons.  c fewer full shells of electrons.  d fewer outer shell electrons.     22 the diagrams show the labels of four bottles.    which label is not correct?    a  b  c  d  bromine  br 2    harmful liquid.  do not spill.  iodine  i2    danger  avoid breathing vapour  from the solid.  potassium  k    danger  store under water.  sodium  na    danger  store under oil.     ",
            "11": "11  \u00a9 ucles 2013 0620/13/o/n/13 [turn over  23 an element has a melting point of 1084  \u00b0c and a density of 8.93  g / cm3. it\u2019s oxide can be used as  a catalyst.    in which position in the periodic table is the element found?    a bc d     24 the diagram shows a light bulb.    filament argon     why is argon used instead of air in the light bulb?  a argon is a good conductor of electricity.  b argon is more reactive than air.  c the filament glows more brightly.  d the filament does not react with the argon.     25 duralumin is an alloy. it contains aluminium, copper and magnesium.    it has many uses including the manufacture of cooking utensils and ships.    which statement about duralumin and its properties is correct?  a it is a good conductor of electricity.  b it is brittle.  c it is soluble in water.  d the aluminium, copper and magnesium are chemically combined.    ",
            "12": "12  \u00a9 ucles 2013 0620/13/o/n/13  26 the list gives the order of some metals (and hydrogen) in the reactivity series.    metal x is also included:    most reactive k   mg   zn  (h)   x  least reactive cu    which row correctly shows the properties of metal x?     reacts with  dilute acids oxide reduced  by carbon  a no no  b no yes  c yes no  d yes yes      27 a new bicycle is being developed.   two different materials are used in its construction, both of which must be corrosion resistant.        which two metals could be used?  a aluminium and mild steel  b aluminium and stainless steel  c mild steel and pure iron  d pure iron and stainless steel     ",
            "13": "13  \u00a9 ucles 2013 0620/13/o/n/13 [turn over  28 iron is extracted from hematite in the blast furnace.    waste gases  raw materials firebrick lining  air  slag  molten iron     the hematite contains silica as an impurity.    what reacts with this impurity to remove it?  a calcium oxide  b carbon  c carbon dioxide  d oxygen     29 in which process is carbon dioxide not formed?  a burning of natural gas  b fermentation  c heating lime  d respiration    ",
            "14": "14  \u00a9 ucles 2013 0620/13/o/n/13  30 carbon dioxide is produced when    x reacts with ethanol.   y reacts with sodium carbonate.    what are x and y?     x y  a h2 hc l  b h2 naoh  c o2 hc l  d o2 naoh      31 a sample of fertiliser is tested by warming it with aqueous sodium hydroxide.    a colourless gas is produced which turns red litmus paper blue.    which element, essential for plant growth, must be present?  a nitrogen  b phosphorus  c potassium  d sulfur      32 iron rusts. this process involves the \u2026\u20261\u2026\u2026 of iron. rusting can be prevented by covering the  iron with grease or paint which stops \u2026\u20262\u2026\u2026 from reaching the surface of the iron.    which words correctly complete gaps 1 and 2?     1 2  a oxidation nitrogen  b oxidation oxygen  c reduction nitrogen  d reduction oxygen    ",
            "15": "15  \u00a9 ucles 2013 0620/13/o/n/13 [turn over  33 oxides of nitrogen are given out from car exhausts.    which row best shows why oxides of nitrogen are unwanted?     acidic toxic  a no no  b no yes  c yes no  d yes yes      34 water is treated at a water works to make it fit to drink.    what is present in the water when it leaves the waterworks?  a bacteria only  b bacteria and insoluble substances  c chlorine only  d chlorine and soluble substances    ",
            "16": "16  \u00a9 ucles 2013 0620/13/o/n/13  35 the diagram shows a kiln used to heat limestone.    gas burners productairwaste gaseslimestone     what is the product and what waste gas is formed?     product waste gas  a lime, cao carbon monoxide  b lime, cao carbon dioxide  c slaked lime, ca(oh) 2 carbon monoxide  d slaked lime, ca(oh) 2 carbon dioxide     36 molecule x is both an alkene and a carboxylic acid.    which row describes x?     saturated \u2013cooh present  a no no  b no yes  c yes no  d yes yes     37 which hydrocarbon reacts with steam to produce ethanol?  a c 2h4 b c2h6 c c3h6 d c3h8     ",
            "17": "17  \u00a9 ucles 2013 0620/13/o/n/13 [turn over  38 petroleum is a mixture of different hydrocarbons.    which process is used to separate the petroleum into groups of similar hydrocarbons?  a combustion  b cracking  c fractional distillation  d reduction     39 which row represents compounds in the same homologous series?    h c hh c hhc hhh h c hhc hhc hhc hhh h c hhc hhc hhh h c hhc hho hh c hhc ohh c hhh c ch hhc hhc hhh h c hhc hhh h c hho hhc hh c hhc brh c hhh h ch ch hch c hhh h c hhc oo ha bcdc ch hh c hhc hhh hh      ",
            "18": "18  \u00a9 ucles 2013 0620/13/o/n/13  40 the diagram shows a flow diagram.    petroleumsubstance x \u25cf  burns with a     yellow flame \u25cf  does not     decolourise    bromine watersubstance y \u25cf  decolourises    bromine water \u25cf  undergoes     addition    polymerisation     which type of organic compounds are x and y?     substance x substance y  a alcohol alkane  b alkane alkene  c alkene alkane  d alkane alcohol     ",
            "19": "19  \u00a9 ucles 2013 0620/13/o/n/13  blank page",
            "20": "20      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2013 0620/13/o/n/13   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w13_qp_21.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 october/november 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib13 11_0620_21/3rp\u00a9 ucles 2013 *7249373810*",
            "2": "2 0620/21/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1 (a)   choose from the list of elements below to answer the following questions. calcium helium iodine nickel nitrogen sodium sulfur   each element can be used once, more than once or not at all.   which element:  (i)  is an element present in most fertilisers,    [1]  (ii)  is in group vi of the periodic table,  ...  [1]  (iii)  is in period 5 of the periodic table,    [1]  (iv)  has a single electron shell containing two electrons,  ..  [1]  (v)  is a transition element,    [1]  (vi)  forms ions with a single negative charge?  ..  [1]  (b)  what is the meaning of the term element  ?   ...    ... ..  [1]  (c)  many of the elements in the periodic table have metallic properties.   describe three  physical properties which are typical of most metals.  1.  ...   2.  ...   3.  ... ..  [3] [total: 10]",
            "3": "3 0620/21/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  hydrogen chloride is an acidic gas.  (a) (i)   complete the dot and cross diagram to show the electronic structure of hydrogen  chloride. h cl [2]  (ii)  is hydrogen chloride a covalent or an ionic compound?   give a reason for your answer.   . .  [1]  (b)  hydrogen chloride reacts with water to form hydrochloric acid.   which one of the following is the most likely ph of hydrochloric acid?   put a ring around the correct answer. ph  2          ph  7          ph  9          ph  14 [1]  (c)  hydrochloric acid reacts with both metal oxides and carbonates.  (i)  complete the word equation for the reaction of hydrochloric acid with calcium  carbonate. hydrochloric  +  calcium    \u2192   ..  +  ..  +  ..  acid carbonate .. .. [3]  (ii)  complete the symbol equation for the reaction of magnesium oxide with hydrochloric  acid. name the salt which is formed. mgo  +  ..hc l  \u2192  mgc l  2  +  h2o  name of salt  .  [2]",
            "4": "4 0620/21/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (d)  a student reacted magnesium with hydrochloric acid to \ufb01 nd out how concentration  affects the rate of reaction. the magnesium was in excess. he measured the volume of hydrogen produced at various time intervals.   the graph shows his results. 0 50 100 150 200 250 300 35050 40302010 0volume of hydrogen  / cm3 time  / seconds  (i)  at what time had the reaction just \ufb01 nished?   . .  [1]  (ii)  what volume of hydrogen gas is given off during the \ufb01 rst 50 seconds of the reaction?  volume of hydrogen ... cm3 [1]  (iii) the student repeated the experiment.   state two factors, apart from the concentration of hydrochloric acid, that should be  kept constant when repeating the experiment.  1.  .. ..  2.  ..   [2] [total: 13]",
            "5": "5 0620/21/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use3  organic compounds can be put into groups called homologous series.  (a)  complete the following sentences about organic compounds and homologous series.  use words from the list below.  carbon chlorine different elements functional  hydrocarbon hydrogen oxide similar sulfur   organic compounds usually contain atoms of ... and ... .    each homologous series contains compounds with . chemical  properties due to the presence of the same . group. [4]  (b)  ethanol belongs to the alcohol homologous series.  (i)  draw the structure of ethanol, showing all atoms and bonds. [2]  (ii)  state the name of the two compounds formed when ethanol burns in excess air.  ..  and  .. [2 ]",
            "6": "6 0620/21/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (c)  salicylic acid is used to make aspirin.   the structure of salicylic acid is shown below. c ccc ccoh h hhoo c hh  (i)  on this structure, put a ring around the carboxylic acid functional group. [1]  (ii)  how many carbon atoms are there in one molecule of salicylic acid?   . .  [1]  (iii)  when making drugs and medicines, it is important that the chemicals used are pure.   state one other area of everyday life where purity is important.   . .  [1] [total: 11]",
            "7": "7 0620/21/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use4  the structures of diamond and graphite are shown below.  diamond graphite= carbon atom  (a)  describe the similarities and differences between these structures.   ...    ...    ...    ...    ...    ... ..  [4]  (b)  graphite burns in excess air to form carbon dioxide.   describe a test for carbon dioxide.  test     result  .. .  [2]  (c)  when graphite is burnt in a limited supply of air, carbon monoxide is formed.   state one adverse effect of carbon monoxide on health.   ... ..  [1]  (d)  in the blast furnace for the production of iron, carbon monoxide reduces  iron( iii) oxide. fe2o3  +  3co  \u2192  2fe  +  3co2   how does this equation show that carbon monoxide is acting as a reducing agent?   ... ..  [1]  (e)  iron( iii) oxide and coke (carbon) are raw materials used in the production of iron.   state the names of two other raw materials used in the blast furnace for the production  of iron.  1.  ...   2.  ... ..  [2] [total: 10]",
            "8": "8 0620/21/o/n/13 \u00a9 ucles 2013for examiner\u2019s use5  many plants contain coloured pigments.   a student crushes some plant leaves in alcohol to extract the pigments.   she then separates the pigments using the apparatus shown below.  (a)  write the correct labels in the boxes in the diagram above. [2]  (b)  draw an x on the diagram above to show where a drop of the pigment solution is placed  at the start of the experiment. [1]  (c)  after leaving the apparatus for half an hour, the pigments separated from each other.   state the name given to this method of separating pigments.   ... ..  [1]  (d)  some plants can absorb nickel from the ground. the nickel can then be extracted from  the plants and puri \ufb01 ed by electrolysis. + \u2013 rod of pure nickel electrolyterod of impure nickelpower supply  (i)  which one of the following is the most suitable electrolyte for this electrolysis.   tick one box.  aqueous copper( ii) sulfate  aqueous nickel( ii) sulfate  solid nickel( ii) sulfate  water [1]",
            "9": "9 0620/21/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (ii)  which one of the following elements is most likely to be formed at the negative  electrode during this electrolysis?   put a ring around the correct answer. chlorine            nickel            sulfur            oxygen [1]  (iii)  the positive electrode is called the anode.   state the name of the negative electrode.   . .  [1]  (e)  electroplating is used to put a thin layer of one metal on top of another by electrolysis.   give two reasons for electroplating metals.  1.  ...   2.  ... ..  [2]  (f) (i)   hydrated nickel( ii) chloride is green in colour.   when hydrated nickel( ii) chloride is heated gently, it changes colour from green to  white.   complete the symbol equation for this reaction. nic l 2.6h2o(s)          nic l 2(s)  +    hydrated nickel( ii) chloride [1]  (ii)  what does the sign  mean?   . .  [1]  (iii)  how can you obtain a sample of green nickel( ii) chloride starting with white nickel( ii)  chloride?   . .  [1] [total: 12]",
            "10": "10 0620/21/o/n/13 \u00a9 ucles 2013for examiner\u2019s use6  the diagram shows a kettle of boiling water. kettlewater vapourwater droplets   as the water vapour cools it turns back to water droplets.  (a)  describe this change of state in terms of the kinetic particle theory.   in your answer, include  \u25cf  the difference in the closeness of the water molecules as the water vapour changes  to water,  \u25cf  the difference in the motion of the water molecules as the water vapour changes to  water.   ...    ...    ...    ...    ... ..  [4]  (b)  water is a common solvent in the laboratory.  (i)  what is meant by the term solvent  ?   . .  [1]  (ii)  state the name of the solvent whose formula is c2h5oh.   . .  [1]  (c)  when ammonium chloride dissolves in water the temperature of the solution falls.   state the name of the energy change which results in the temperature falling.   ... ..  [1]",
            "11": "11 0620/21/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (d)  which one of the following conducts electricity.   tick one box.  aqueous ammonium chloride solid ammonium chloride ammonia gas chlorine gas [1]  (e) (i)   complete the symbol equation for the reaction of lithium with water to form lithium  hydroxide and hydrogen. 2li  +  .h 2o  \u2192  2..  +  h2 [2]  (ii)  when 14  g of lithium react with water, 4  g of hydrogen are formed.   calculate the mass of hydrogen formed when 70  g of lithium react with water. [1] [total: 11]",
            "12": "12 0620/21/o/n/13 \u00a9 ucles 2013for examiner\u2019s use7  the table shows some properties of seven different substances. substancedensity / g per cm3relative  strengthrelative electrical  conductivityrelative  thermal  conductivity aluminium 2.7 15 42 200.0 ceramic 2.5 15 does not conduct 1.6copper 8.9 20 63 385.0iron 7.9 25 11 80.0lead 11.4 15 5 38.0poly(ethene) 0.9 1 does not conduct 0.3steel 7.8 90 2 25.0  (a)  use the information in this table to answer the following questions.  (i)  which substance is the best conductor of heat?   . .  [1]  (ii)  suggest why copper is preferred to iron for electrical wiring in houses.   . .  [1]  (iii)  what property of ceramic makes it a good electrical insulator?   . .  [1]  (iv)  which pure metal in the table conducts electricity least well?   . .  [1]  (v)  suggest why steel rather than iron is used in making machinery.   . .  [1]  (vi)  which metal in the table is the most dense?   . .  [1]  (b)  a solution of a metal salt reacts with aqueous sodium hydroxide to form a white precipitate.  the white precipitate is soluble in excess aqueous sodium hydroxide.  (i)  which one of the following ions is most likely to be present in the salt?   put a ring around the correct answer. calcium            copper( ii)            iron( ii)            zinc [1]  (ii)  state the name of the white precipitate.   . .  [1]",
            "13": "13 0620/21/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  copper( ii) chloride can be made by the action of hydrochloric acid on copper( ii) oxide.   put the statements, a, b, c and d, about this preparation in the correct order.  a leave the saturated solution to crystallise.  b filter the solution to remove excess copper( ii) oxide.  c add excess copper( ii) oxide to hydrochloric acid and warm.  d evaporate the \ufb01 ltrate to the crystallisation point.   ... ..  [1]  (d)  the structure of copper( ii) chloride is shown below. cu2+ cu2+cu2+cu2+cl \u2013cl \u2013 cl \u2013cl \u2013 cl \u2013cl \u2013cu2+ cu2+cl \u2013cl \u2013 cl \u2013cl \u2013 cl \u2013cl \u2013  write the simplest formula for copper( ii) chloride.   ... ..  [1]  (e)  suggest the product formed at each electrode when molten copper( ii) chloride is  electrolysed.  at the positive electrode    at the negative electrode    [2]  (f)  when copper( ii) chloride is heated strongly, a gas is given off.   the gas is green in colour and bleaches litmus paper.   state the name of this gas.   ... ..  [1] [total: 13]",
            "14": "14 0620/21/o/n/13blank page \u00a9 ucles 2013",
            "15": "15 0620/21/o/n/13blank page \u00a9 ucles 2013",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/21/o/n/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w13_qp_22.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 october/november 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib13 11_0620_22/2rp\u00a9 ucles 2013 *5048513202*",
            "2": "2 0620/22/o/n/13blank page \u00a9 ucles 2013",
            "3": "3 0620/22/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use1 (a)   choose from the list of compounds below to answer the following questions. ammonia ammonium chloride calcium carbonate calcium oxide copper( ii) sulfate ethane iron( ii) chloride methane water   each compound can be used once, more than once or not at all.   which compound:  (i)  is an alkaline gas,  ... [1]  (ii)  is a gas contributing to climate change,  . [1]  (iii)  is a salt containing only non-metals,  ... [1]  (iv)  turns blue cobalt chloride paper pink,  . [1]  (v)  reacts with an acid to release carbon dioxide,   [1]  (vi)  gives a light blue precipitate when aqueous sodium hydroxide is added to a solution  of its aqueous ions?   [1]  (b) what is the meaning of the term compound  ?   ...    ... ..  [1]  (c)  complete the following symbol equation for the complete combustion of methane in  oxygen. ch4  +  ...o2  \u2192  ..  +  2h2o [2] [total: 9]",
            "4": "4 0620/22/o/n/13 \u00a9 ucles 2013for examiner\u2019s use2 (a)   the table describes the reactivity of some metals with hydrochloric acid. metal observations calcium many bubbles produced. reaction mixture may boil. magnesium steady stream of bubbles produced. reaction mixture gets hot. sodium many bubbles produced. may explode. zinc slow stream of bubbles produced. reaction mixture rises  slightly in temperature.   put these metals in order of their reactivity. least reactive most reactive [2]  (b)  complete the word equation for the reaction of magnesium with hydrochloric acid. magnesium  +  hydrochloric acid  \u2192    +     [2]  (c)  when magnesium reacts with hydrochloric acid, magnesium atoms lose electrons.   what type of magnesium particle is formed?   put a ring around the correct answer. covalent          ion           molecule          proton [1]  (d)  complete the diagram to show the electronic structure of a sodium atom. na [2]",
            "5": "5 0620/22/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (e)  a student added large lumps of zinc to 20  cm3 of 2  mol  / dm3 hydrochloric acid.   she carried out the reaction at 15  \u00b0c.   she measured the volume of gas given off at various time intervals.  (i)  draw a labelled diagram of the apparatus she could use for this experiment. [3]  (ii)  describe three  different things she could do to increase the rate of this reaction.  1.  .. ..  2.  .. ..  3.  ..   [3] [total: 13]",
            "6": "6 0620/22/o/n/13 \u00a9 ucles 2013for examiner\u2019s use3  the diagram below shows the apparatus which can be used to obtain pure water from sea-water. heatsea-water pure water  (a)  state the name of this process.   ... ..  [1]  (b)  label the boxes on the diagram above with the correct names of the pieces of apparatus  shown. [3]  (c)  complete the following sentences using words from the list below.  boils condenses cools freezes  higher lower melts  water has a . boiling point than salt. when a solution of salt is heated   strongly, the water . and escapes as steam. when the steam cools, it . back to liquid water. [3]",
            "7": "7 0620/22/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (d)  the table shows the concentration of the seven most abundant compounds in sea-water.  compound ions presentconcentration in g  / m3 calcium carbonate ca2+  and  co32\u2013100 calcium sulfate ca2+  and  so42\u20131 800 magnesium chloride mg2+  and  c l \u20136 800 magnesium sulfate 5 700potassium bromide k +  and  br  \u2013100 potassium chloride k+  and  c l \u2013800 sodium chloride na+  and  c l \u201328 000  (i)  which negative ion is present in the greatest concentration in sea-water?   . .  [1]  (ii)  which positive ion is present in the lowest concentration in sea-water?    . .  [1]  (iii)  write the formulae of the two ions present in magnesium sulfate.   . .  [2] [total: 11]",
            "8": "8 0620/22/o/n/13 \u00a9 ucles 2013for examiner\u2019s use4 (a)   match the compounds on the left with the statements on the right.   the \ufb01 rst one has been done for you. butane poly(ethene) ethene methane ethanoic acida hydrocarbon containing four carbon atoms it decolourises bromine water it is the main constituent of natural gas it contains a \u2013cooh functional group it has a very long chain of carbon atoms [4]  (b)  methane and ethene are hydrocarbons.  (i)  what is meant by the term hydrocarbon  ?   . .  [1]  (ii)  the structure of ethene is shown below. cch hhh   use this structure to explain why ethene is an unsaturated hydrocarbon.   . .  [1]  (c)  molecules of ethene react together at high temperature and pressure to form poly(ethene).    which one of the following words best describes the molecules of ethene in this reaction?   put a ring around the correct answer. acids          alkanes          monomers          polymers [1]",
            "9": "9 0620/22/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (d)  ethanoic acid can be made by the oxidation of ethanol.  (i)  what is meant by the term oxidation  ?   . .  [1]  (ii)  ethanol can be made by fermentation.   complete the word equation for fermentation.  yeast ..      \u2192      ..    +    ethanol  .. [2] [total: 10]",
            "10": "10 0620/22/o/n/13 \u00a9 ucles 2013for examiner\u2019s use5 (a)   explain why metals are often used in the form of alloys.   in your answer, write about  \u25cf  the structure of an alloy,  \u25cf why alloys are often more useful than pure metals.   ...    ...    ...    ...    ... ..  [3]  (b)  iron is a transition element.  (i)  which two of the following statements about iron are correct?   tick two boxes.  a freshly-cut surface of iron is green in colour. iron exists in only one oxidation state in its compounds. iron has a high density. iron has a giant covalent structure. iron has a high melting point. [2]  (ii)  describe one method of rust prevention and explain how it works.  method  .. .  how this works  ...  . .  [2]  (c)  iron is used as a catalyst in the haber process for making ammonia.  (i)  what does the term catalyst  mean?   . .  [1]  (ii)  describe a test for ammonia.  test   .  result    [2]",
            "11": "11 0620/22/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (iii)  ammonia is used to make fertilisers.   explain why farmers need to add fertilisers to the soil.   . ...   . ...   . .  [2] [total: 12]",
            "12": "12 0620/22/o/n/13 \u00a9 ucles 2013for examiner\u2019s use6 (a)   garlic is a vegetable that is often used in cooking. it has a strong smell.   a student is cutting up garlic in the kitchen.   after a time, the smell of the garlic travels all over the house even though there are no  currents of air.   use the kinetic particle theory to explain why the smell of garlic travels all over the house.   ...    ...    ...    ... ..  [3]  (b)  the smell of garlic is due to a compound containing sulfur.   the structure of this compound (compound a) is shown below. ch2  ch  \u2014 ch2 \u2014 s \u2014 s \u2014 ch2 \u2014 ch   ch2 compound a  (i)  write the molecular formula for this compound.   . .  [1]  (ii)  another organic sulfur compound (compound b) is shown below. ch2 h2cc2h5 sch c compound b   by comparing the formulae of compound a and compound b, how can you tell that  compound a has the higher relative molecular mass?   you are not required to do any mathematical calculations.   . ...   . .  [2]",
            "13": "13 0620/22/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  an isotope of sulfur has a nucleon number of 34 and an atomic number of 16.  (i)  how many neutrons are there in one atom of this isotope of sulfur?   . .  [1]  (ii)  what is meant by the terms  isotope ,  ..   . .  [1]  nucleon number  ?    [1]  (iii)  some fuels contain sulfur as a contaminating substance.   complete the following sentences using words from the list below.  coal dioxide hydrogen monoxide  nitrogen oxidised reduced water  fuels such as ... contain sulfur.   when these fuels burn, the sulfur is ... to sulfur ... .    this reacts with ... in the atmosphere to form an acidic solution. [4]  (iv)  describe and explain the effect of acid rain on buildings made of limestone.   . ...   . ...   . .  [2] [total: 15]",
            "14": "14 0620/22/o/n/13 \u00a9 ucles 2013for examiner\u2019s use7  the diagram shows a kiln for making lime (calcium oxide) from limestone (calcium carbonate). a b d cbrick lime kiln  (a) (i)   which letter on the diagram above shows   where the limestone is added,  ...   where the waste gases exit from the kiln?  ...  [2]  (ii)  complete the symbol equation for the decomposition of limestone. caco3  \u2192  cao  +  . [1]  (iii)  when 50  g of calcium carbonate is decomposed, 28  g of calcium oxide is formed.   calculate the minimum mass of calcium carbonate needed to produce 8.4  g of  calcium oxide. [1]  (b)  the table below shows the temperatures at which some group ii carbonates decompose. group ii carbonatetemperature at which group ii carbonates decompose  / \u00b0c beryllium carbonate 100 magnesium carbonate 350 calcium carbonate 900  (i)  describe the pattern in the ease of decomposition of group ii carbonates.   . .  [1]",
            "15": "15 0620/22/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (ii)  predict the decomposition temperature of barium carbonate. . \u00b0c  [1]  (c)  lime is calcium oxide.  (i)  state one use of lime.   . .  [1]  (ii)  what type of oxide is calcium oxide?   . .  [1]  (iii)  calculate the relative formula mass of calcium oxide.   use your periodic table to help you. [1]  (d)  calcium is extracted from its compounds by electrolysis.   suggest why calcium is extracted by electrolysis rather than by reduction with carbon.   ... ..  [1] [total: 10]",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/22/o/n/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w13_qp_23.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may need to use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/23   paper 2 october/november 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib13 11_0620_23/2rp\u00a9 ucles 2013 *3407475716*",
            "2": "2 0620/23/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1 (a)   choose from the list of metals below to answer the following questions. aluminium bariumcalcium iron lithiumsilver   each metal can be used once, more than once or not at all.  (i)  which metal has an atom with three electrons in its outer electron shell?   . .  [1]  (ii)  which two metals are in the same period of the periodic table?  ..  and  .. [1 ]  (iii)  which metal has an atom with three protons in its nucleus?   . .  [1]  (iv)  which metal has a nitrate which is used to test for halide ions?   . .  [1]  (v)  which metal is used in food containers because of its resistance to corrosion?   . .  [1]  (b)  describe two chemical properties of iron.  1.  ...   2.  ... ..  [2]  (c)  describe brie \ufb02 y how iron from the blast furnace is made into steel.   ...    ...    ... ..  [2] [total: 9]",
            "3": "3 0620/23/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  helium is in group 0 of the periodic table.  (a)  describe the structure of a helium atom. use your periodic table to help you.   in your answer, include  \u25cf the type and number of subatomic particles present,  \u25cf the position of these particles in the atom,  \u25cf the relative charges on the particles.   ...    ...    ...    ...    ...    ... ..  [5]  (b)  give one use of helium.   ... ..  [1]  (c)  some elements in group 0 can form compounds with \ufb02 uorine and oxygen.   the structure of one of these compounds is shown below. xe f ffo f   calculate the relative molecular mass of this compound.   use your periodic table to help you.   you must show all your working. [2]  (d)  fluorine is a diatomic molecule. it melts at \u2013220  \u00b0c and boils at \u2013188  \u00b0c.  (i)  what is the physical state of \ufb02 uorine   at room temperature,  .  at \u2013200  \u00b0c?  ..  [2]  (ii)  what is meant by the term diatomic  ?   . .  [1] [total: 11]",
            "4": "4 0620/23/o/n/13 \u00a9 ucles 2013for examiner\u2019s use3  this question is about calcium and some calcium compounds.  (a)  calcium is in group ii of the periodic table.   complete the diagram below to show the electronic structure of calcium. ca [2]  (b)  calcium reacts with hydrochloric acid to form a salt with the formula cac l 2.   state the name of this salt.   ... ..  [1]  (c)  calcium carbonate reacts with hydrochloric acid.   the course of this reaction can be followed by measuring the volume of carbon dioxide  given off at various time intervals.   the graph below shows the results obtained from an experiment using 0.15  g of calcium  carbonate in small pieces. 0 50 100 150 200 time  / seconds250 300 350 400volume of carbon dioxide  / cm350 40302010 0",
            "5": "5 0620/23/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (i)  what volume of gas is given off in the \ufb01 rst 75 seconds of the reaction?   . .  [1]  (ii)  on the grid opposite, sketch the line you would expect for the same reaction using  large pieces of calcium carbonate. assume that the mass of the calcium carbonate and all other conditions remain the same. [2]  (iii)  what would happen to the rate of this reaction if:   the temperature is increased,   . ...   the concentration of hydrochloric acid is decreased?   . .  [2]  (d)  when calcium carbonate is heated at high temperatures, calcium oxide and carbon  dioxide are formed.  (i)  which one of the following words best describes this reaction?   put a ring around the correct answer. combustion          decomposition          exothermic          reduction [1]  (ii)  describe a test for carbon dioxide.   test  .    result    [ 2]  (e)  calcium oxide can be used to neutralise acidic industrial waste.  (i)  complete the word equation for the reaction of calcium oxide with nitric acid. calcium oxide  +  nitric acid  \u2192    +     [2] (ii)  state one other use of calcium oxide.   . .  [1]  (iii)  when calcium oxide reacts with water, heat is given off.   state the name given to a chemical reaction which gives off heat.   . .  [1] [total: 15]",
            "6": "6 0620/23/o/n/13 \u00a9 ucles 2013for examiner\u2019s use4  the diagram shows how a liquid alkane can be cracked in a school laboratory to form a  mixture of gaseous and liquid hydrocarbons. watercatalyst (aluminium oxide granules) liquid alkane (absorbed in mineral wool)  (a)  what piece of apparatus is missing from the diagram?   ... ..  [1]  (b)  on the diagram above, put an x to show where the gas is collected. [1]  (c)  what is the purpose of the catalyst?   ... ..  [1]  (d)  complete the equation to show the cracking of dodecane, c12h26, to form octane and  one other substance. c12h26  \u2192  c8h18  +  . [1]  (e)  cracking produces a mixture of shorter-chain alkanes and alkenes.  (i)  describe what you would observe when a few drops of bromine water are added to  an alkene.   . .  [1]",
            "7": "7 0620/23/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (ii)  which one of the following compounds, a, b, c or d, is formed when bromine water  reacts with ethene? ch h ca br brc h h hc hb br br c h c hoh oh oh ohc c cd br brbr brbr br   . .  [1]  (iii)  poly(ethene) is made by combining ethene monomers.   which one of the following describes this reaction?   tick one box.  decomposition neutralisation oxidation polymerisation [1]  (f)  many alkanes found in petrol are branched hydrocarbons.   one example is shown below. c cc hh h hchh c chh h h hhhhh h c  (i)  write the molecular formula for this hydrocarbon.   . .  [1]  (ii)  what is meant by the term hydrocarbon  ?   . .  [1]  (g)  state the name of the two products formed when a hydrocarbon burns in excess air.  .  and  ..  [2] [total: 11]",
            "8": "8 0620/23/o/n/13 \u00a9 ucles 2013for examiner\u2019s use5  ethanol can be made by fermentation. fermentation mixtureu-shaped tubecontaining wate r  (a)  apart from yeast, what other substances are present in the reaction mixture?   tick two boxes.  copper sulfate ethene sugar methane water [2]  (b)  what method is used to separate ethanol from the rest of the reaction mixture?   ... ..  [1]  (c)  complete the structure of ethanol.   c c hh h hh [1]  (d)  ethanol belongs to the alcohol homologous series.   which one of the following compounds also belongs to the alcohol homologous series?   put a ring around the correct answer. butene          hexane          ethanoic acid          octanol [1]  (e)  describe one other way, apart from fermentation, by which ethanol can be made on an  industrial scale. include the necessary reaction conditions in your answer.   ...    ...    ... ..  [3] [total: 8]",
            "9": "9 0620/23/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use6 (a)   when hydrated copper( ii) sulfate is heated, the following reaction occurs: cuso4.5h2o(s)                      cuso4(s)           +           5h2o(l)  hydrated copper( ii) sulfate anhydrous copper( ii) sulfate  (i)  what does the sign  mean?   . .  [1]  (ii)  explain how this reaction is used as a chemical test for water.   . ...   . .  [2]  (iii)  copper( ii) sulfate is a salt.   sodium chloride is also a salt. solid sodium chloride does not conduct electricity.   suggest two things you could do to make solid sodium chloride conduct electricity.  1.  .. ..  2.  ..   [2]  (b)  copper ore contains copper, iron and sulfur.   copper is extracted by heating copper ore with sand and oxygen.  (i)  in the \ufb01 rst stage of this process, the copper ore is heated in a furnace.   a liquid mixture containing copper sul \ufb01 de and iron sul \ufb01 de is formed. the sand reacts  with the impurities to form a slag. waste gases oxygen slag out mixture outslag mixture of copper sulfide + iron sulfide   what information in the diagram above suggests that the slag is less dense than the  mixture of copper and iron sul \ufb01 des.   . .  [1]",
            "10": "10 0620/23/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (ii)  in a later stage, copper sul \ufb01 de is reacted with more oxygen. cu2s  +  o2  \u2192  2cu  +  so2   how does this equation show that the sulfur in copper sul \ufb01 de gets oxidised?   . .  [1]  (iii)  copper is puri \ufb01 ed by electrolysis using copper electrodes. +\u2013a c db   which letter, a, b, c or d, in the diagram above represents   the cathode,  ...   the electrolyte?    [2] [total: 9]",
            "11": "11 0620/23/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use7  the graph below shows how the temperature rises with time when a solid, p, is heated  steadily and changes to a liquid and then to a gas. 0 20 40 60200 180160140120100 80604020 0temperature  / \u00b0c time  / seconds  (a)  use the information on the graph to deduce  the melting point of p,  ...  the state of p at 160  \u00b0c.  ..  [2]  (b)  explain what happens to the arrangement and motion of the particles when a solid  changes to a liquid.  arrangement  .   motion  .. ...  [2]",
            "12": "12 0620/23/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (c)  a student placed a purple crystal in a \ufb02 ask of organic solvent.   after 10 minutes, the crystal had completely disappeared and a dense purple colour was  observed at the bottom of the \ufb02 ask.   after 2 hours, the purple colour had spread throughout the solvent. organic solvent crystal  at startafter 10 minutes after 2 hours   use the kinetic particle theory to explain these observations.   ...    ...    ...    ... ..  [3] [total: 7]",
            "13": "13 0620/23/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use8 (a)  state two differences between a mixture and a compound.   ...    ...    ... ..  [2]  (b)  plant ash is a mixture of large insoluble particles and salts which are soluble in water.   in parts of africa, salts are traditionally obtained from plant ash.   water is added to the plant ash.   the apparatus shown below is then used to remove the insoluble particles. clay potclay bowl holes in clay bowlplant ash and water strips of banana leafwith holes in them   explain how this apparatus separates the salts from the insoluble particles.   ...    ...    ...    ... ..  [2]",
            "14": "14 0620/23/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (c)  the composition and solubility of some salts found in the ash from the papyrus plant are  shown in the table below. saltion present in the saltmass of salt per 100  g of ash  / gsolubility of salt in g  / dm3 magnesium sulfate mg2+  and  so42\u20135 220 potassium carbonate k+  and  co32\u201310 1120 potassium chloride k+  and  c l \u201318 359 potassium sulfate 4 122sodium carbonate na +  and  co32\u201312 70 sodium chloride na+  and  c l \u201340 359  (i)  which salt in the table has the lowest solubility in g  / dm3?   . .  [1]  (ii)  which negatively-charged ion is present in the highest amount in the ash?   . .  [1]  (iii)  write the symbols for the two ions present in potassium sulfate.   . .  [2]  (d)  sodium chloride reacts with lead( ii) nitrate to form sodium nitrate and lead( ii) chloride.   complete the symbol equation for this reaction. ...nac l  +  pb(no3)2  \u2192  2nano3  +  pbc l 2 [1]  (e)  complete the following sentence about the formation of chloride ions.   chloride ions are formed when chlorine atoms gain  . [1] [total: 10]",
            "15": "15 0620/23/o/n/13blank page \u00a9 ucles 2013",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/23/o/n/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w13_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) october/november 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib13 11_0620_31/3rp r \u00a9 ucles 2013 \uf02a\uf038\uf037\uf037\uf032\uf030\uf037\uf038\uf030\uf032\uf031\uf02a",
            "2": "2 0620/31/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1  for each of the following, name an element which matches the description.  (a)  it is used as a fuel in nuclear reactors.   ... ..  [1]  (b)  it is the only non-metal which is a good conductor of electricity.   ... ..  [1]  (c)  inert electrodes are made from this metal.   ... ..  [1]  (d)  this gaseous element is used to \ufb01 ll balloons in preference to hydrogen.   ... ..  [1]  (e)  an element which can form an ion of the type x3\u2013.   ... ..  [1]  (f)  it has the same electron distribution as the calcium ion, ca2+.   ... ..  [1]  (g)  the element is in period 5 and group vi.   ... ..  [1] [total: 7]",
            "3": "3 0620/31/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2 (a)  give three  differences in physical properties between the group i metal, potassium, and  the transition element, iron.  1.  ...   2.  ...   3.  ... ..  [3]  (b)  the following metals are in order of reactivity.  potassium  zinc copper   for those metals which react with water or steam, name the products of the reaction,  otherwise write \u2018no reaction\u2019.  potassium  ... ..   ...   zinc   ...   ...   copper  ...   ... ..  [5] [total: 8]",
            "4": "4 0620/31/o/n/13 \u00a9 ucles 2013for examiner\u2019s use3  ammonia is manufactured by the haber process. n2(g)  +  3h2(g)    2nh3(g)   the forward reaction is exothermic.  (a)  describe how the reactants are obtained.  (i)  nitrogen   . ...   . .  [2]  (ii) hydrogen   . ...   . ...   . .  [3]  (b)  the percentage of ammonia in the equilibrium mixture varies with temperature and  pressure.  (i)  which pair of graphs, a, b or c, shows correctly how the percentage of ammonia at  equilibrium varies with temperature and pressure? percentagenh 3 at equilibrium temperaturepercentage nh3 at equilibrium pressurepair a percentage nh3 at equilibrium temperaturepercentage nh3 at equilibrium pressurepair b percentage nh3 at equilibrium temperaturepercentage nh3 at equilibrium pressurepair c  the pair with both graphs correct  is  .  [1]",
            "5": "5 0620/31/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (ii)  give a full explanation of why the pair of graphs you have chosen in (i) is correct.   . ...   . ...   . ...   . ...   . ...   . ...   . .  [6]  (iii)  catalysts do not alter the position of equilibrium. explain why a catalyst is used in  this process.   . ...   . ...   . ...   . .  [2] [total: 14]",
            "6": "6 0620/31/o/n/13 \u00a9 ucles 2013for examiner\u2019s use4  20.0  g of small lumps of calcium carbonate and 40  cm3 of hydrochloric acid, concentration  2.0  mol  / dm3, were placed in a \ufb02 ask on a top pan balance. the mass of the \ufb02 ask and contents  was recorded every minute. cotton wool to preventdrops of acid spray escaping flask 40  cm3 of hydrochloric acid, 2.0  mol  / dm3 20.0  g of small lumps of calcium carbonate balance  the mass of carbon dioxide given off was plotted against time. 00timemass of carbon dioxide caco3(s)  +  2hc l (aq)  \uf0ae  cac l 2(aq)  +  h2o(l)  +  co2(g)   in all the experiments mentioned in this question, the calcium carbonate was in excess.  (a) (i)   explain how you could determine the mass of carbon dioxide given off in the \ufb01 rst \ufb01 ve  minutes.   . .  [1]  (ii)  label the graph f where the reaction rate is the fastest, s where it is slowing down  and 0 where the rate is zero. [2]  (iii)  explain how the shape of the graph shows where the rate is fastest, where it is  slowing down and where the rate is zero.   . ...   . ...   . .  [2]  (b)  sketch on the same graph, the line which would have been obtained if 20.0  g of small  lumps of calcium carbonate and 80  cm3 of hydrochloric acid, concentration 1.0  mol  / dm3,  had been used. [2]",
            "7": "7 0620/31/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  explain in terms of collisions between reacting particles each of the following.  (i)  the reaction rate would be slower if 20.0  g of larger lumps of calcium carbonate and  40  cm3 of hydrochloric acid, concentration 2.0  mol  / dm3, were used.   . ...   . ...   . .  [2]  (ii)  the reaction rate would be faster if the experiment was carried out at a higher  temperature.   . ...   . ...   . .  [2]  (d)  calculate the maximum mass of carbon dioxide given off when 20.0  g of small lumps of  calcium carbonate react with 40  cm3 of hydrochloric acid, concentration 2.0  mol  / dm3. caco3(s)  +  2hc l (aq)  \uf0ae  cac l 2(aq)  +  h2o(l)  +  co2(g)  number of moles of hc l used = mass of carbon dioxide = . g  [4] [total: 15]",
            "8": "8 0620/31/o/n/13 \u00a9 ucles 2013for examiner\u2019s use5  the alkenes are unsaturated hydrocarbons. they form a homologous series, the members of  which have the same chemical properties.   they undergo addition reactions and are easily oxidised.  (a)  the following hydrocarbons are isomers. ch3 ch3ch2 ch ch ch3 ch2 ch2 ch2 ch  (i)  explain why these two hydrocarbons are isomers.   . ...   . .  [2]  (ii)  give the structural formula of another hydrocarbon which is isomeric with the above. [1]  (b)  give the structural formula and name of each of the products of the following addition  reactions.  (i)  ethene and bromine  structural formula of product   name of product  ...  [2]  (ii) propene and hydrogen  structural formula of product  name of product  ...  [2]  (iii)  but-1-ene and water  structural formula of product  name of product  ...  [2]",
            "9": "9 0620/31/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  alkenes can be oxidised to carboxylic acids.  (i)  for example, propene, ch3 \u2013 ch  = ch2, would produce ethanoic acid, ch3 \u2013 cooh,  and methanoic acid, h  \u2013 cooh. deduce the formulae of the alkenes which would  form the following carboxylic acids when oxidised.   ethanoic acid and propanoic acid  only ethanoic acid [2]  (ii)  describe the colour change you would observe when an alkene is oxidised with  acidi \ufb01 ed potassium manganate( vii).   . .  [2]  (d)  alkenes polymerise to form addition polymers.   draw the structural formula of poly(cyanoethene), include at least two monomer units.  the structural formula of the monomer, cyanoethene, is given below. cch cnhh [3] [total: 16]",
            "10": "10 0620/31/o/n/13 \u00a9 ucles 2013for examiner\u2019s use6  lead is an excellent roo \ufb01 ng material. it is malleable and resistant to corrosion. lead rapidly  becomes coated with basic lead carbonate which protects it from further corrosion.  (a)  lead has a typical metallic structure which is a lattice of lead ions surrounded by a \u2018sea\u2019  of mobile electrons. this structure is held together by attractive forces called a metallic bond.  (i) explain why there are attractive forces in a metallic structure.   . ...   . .  [2]  (ii)  explain why a metal, such as lead, is malleable.   . ...   . .  [2]  (b)  basic lead( ii) carbonate is heated in the apparatus shown below. water and carbon  dioxide are produced. soda lime,carbon dioxidereacts herebasic lead carbonate heat u-tube filled with silica gel to absorb water  (i)  silica gel absorbs water. silica gel often contains anhydrous cobalt( ii) chloride.  when this absorbs water it changes from blue to pink.   suggest a reason.   . .  [1]  (ii)  soda lime is a mixture of sodium hydroxide and calcium oxide. why do these two  substances react with carbon dioxide?   . ...   . .  [2]  (iii)  name two substances formed when soda lime reacts with carbon dioxide.   . .  [2]",
            "11": "11 0620/31/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  basic lead( ii) carbonate has a formula of the type xpbco3.ypb(oh)2 where x and y are  whole numbers.   determine x and y from the following information. pbco3  \uf0ae  pbo  +  co2 pb(oh)2  \uf0ae\uf020 pbo  +  h2o   when heated, the basic lead( ii) carbonate gave 2.112  g of carbon dioxide and 0.432  g of  water.  mass of one mole of co2 = 44  g  mass of one mole of h2o = 18  g  number of moles of co2 formed = . [1]  number of moles of h2o formed = . [1]  x = .  and  y = .   formula of basic lead( ii) carbonate is    [1] [total: 12]",
            "12": "12 0620/31/o/n/13 \u00a9 ucles 2013for examiner\u2019s use7 (a)  the following are two examples of substitution reactions. only the reaction involving  chlorine is a photochemical reaction. ch4  +  c l 2  \uf0ae  ch3cl  +  hc l ch4  +  br2  \uf0ae\uf020 ch3br  +  hbr  (i)  explain the phrase substitution reaction .   . ...   . .  [1]  (ii)  how do photochemical reactions differ from other reactions?   . ...   . .  [1]  (b)  bond forming is exothermic, bond breaking is endothermic. explain the difference  between an exothermic reaction and an endothermic reaction.   ...    ... ..  [2]",
            "13": "13 0620/31/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  use the bond energies to show that the following reaction is exothermic.   bond energy is the amount of energy (kj  / mol) which must be supplied to break one mole  of the bond. h ch hhh ch hclcl cl h cl ++ \u2192  bond energies in kj  / mol  c l \u2013cl +242   c\u2013c l +338  c\u2013h +412 h\u2013c l +431  bonds broken energy in kj  / mol  .. . .. . total energy = .  bonds formed energy in kj  / mol  .. . .. . total energy = .   ...    ... ..  [4] [total: 8]",
            "14": "14 0620/31/o/n/13blank page \u00a9 ucles 2013",
            "15": "15 0620/31/o/n/13blank page \u00a9 ucles 2013",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/31/o/n/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w13_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) october/november 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib13 11_0620_32/2rp\u00a9 ucles 2013 *3900490383*",
            "2": "2 0620/32/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1  the table gives the melting points, the boiling points and the electrical properties of six  substances a to f. substancemelting point / \u00b0cboiling point / \u00b0celectrical conductivity as a solidelectrical conductivity as a liquid a \u2013210 \u2013196 does not conduct does not conduct b 777 1627 does not conduct good conductor c 962 2212 good conductor good conductord \u201394 63 does not conduct does not conduct e 1410 2355 does not conduct does not conduct f 1064 2807 good conductor good conductor  (a) which two substances could be metals?  ...  [1]  (b) which substance could be nitrogen?  ..  [1]  (c) which substance is an ionic solid?  .  [1]  (d) which substance is a liquid at room temperature?  .  [1]  (e) which substance has a giant covalent structure similar to that of diamond? ..  [1]  (f) which two substances could exist as simple covalent molecules?  ...  [1] [total: 6]",
            "3": "3 0620/32/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  the halogens are a collection of diatomic non-metals in group vii.  (a) (i)   de\ufb01 ne the term diatomic .   . .  [1]  (ii)  what do the electron distributions of the halogens have in common?   . .  [1]  (iii)  how do their electron distributions differ?   . .  [1]  (iv)  complete the table. halogensolid, liquid or gas at room temperaturecolour chlorine . . bromine . . iodine . . [2]  (b)  the halogens react with other non-metals to form covalent compounds.   draw a diagram which shows the arrangement of the valency electrons in one molecule  of the covalent compound arsenic tri \ufb02 uoride.   the electron distribution of an arsenic atom is  2 + 8 + 18 + 5.   use x to represent an electron from an arsenic atom.   use o to represent an electron from a \ufb02 uorine atom. [3]",
            "4": "4 0620/32/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (c)  photochromic glass is used in sunglasses. in bright light, the glass darkens reducing  the amount of light reaching the eye. when the light is less bright, the glass becomes colourless increasing the amount of light reaching the eye.   photochromic glass contains very small amounts of the halides silver( i) chloride and  copper( i) chloride.   the reaction between these two chlorides is photochemical. agc l   +   cuc l      ag   +   cuc l 2  colourless colourless black colourless  how does photochromic glass work?   ...    ...    ... ..  [3] [total: 11]",
            "5": "5 0620/32/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use3 (a)  nitric acid is now made by the oxidation of ammonia. it used to be made from air and  water. this process used very large amounts of electricity.   air was blown through an electric arc and heated to 3000  \u00b0c.  n2(g)  +  o2(g)    2no(g) equilibrium 1  nitric oxide    the equilibrium mixture leaving the arc contained 5  % of nitric oxide. this mixture was  cooled rapidly. at lower temperatures, nitric oxide will react with oxygen to form nitrogen dioxide.  2no(g)  +  o 2(g)    2no2 equilibrium 2   nitrogen dioxide reacts with oxygen and water to form nitric acid.  (i)  suggest a reason why the yield of nitric oxide in equilibrium 1  increases with  temperature.   . .  [1]  (ii)  what effect, if any, would increasing the pressure have on the percentage of nitric  oxide in equilibrium 1 ? explain your answer.   . ...   . .  [2]  (iii)  deduce why equilibrium 2 is only carried out at lower temperatures.   . ...   . .  [2]  (iv)  complete the equation for the reaction between nitrogen dioxide, water and oxygen  to form nitric acid.  no2  +  o2  +    \u2192  hno3 [2]  (v)  ammonia is more expensive than water and air. suggest a reason why the ammonia-based process is preferred to the electric arc process.   . .  [1]",
            "6": "6 0620/32/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (b) (i)   nitric acid is used to make the fertiliser ammonium nitrate, nh4no3.   what advantage has this fertiliser over another common fertiliser, ammonium sulfate,  (nh4)2so4?   . .  [1]  (ii)  plants need nitrogen to make chlorophyll. explain why chlorophyll is essential for  plant growth.   . ...   . ...   . ...   . ...   . .  [4] [total: 13]",
            "7": "7 0620/32/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use4  for centuries, iron has been extracted from its ore in the blast furnace. the world production  of pig iron is measured in hundreds of million tonnes annually.  (a)  the following raw materials are supplied to a modern blast furnace.  iron ore which is hematite, fe2o3  limestone which is calcium carbonate  carbon in the form of coke air   describe the essential reactions in the blast furnace. each of the four raw materials must  be mentioned at least once. give the equation for the reduction of hematite.   ...    ...    ...    ...    ...    ...    ...    ...    ... ..  [6]  (b)  each year, blast furnaces discharge millions of tonnes of carbon dioxide into the  atmosphere. this will increase the percentage of atmospheric carbon dioxide.  (i)  explain why this increased percentage of carbon dioxide may cause problems in the  future.   . ...   . .  [2]  (ii)  until the early eighteenth century, charcoal, not coke, was used in the blast furnace.   charcoal is made from wood but coke is made from coal. explain why the use of charcoal would have a smaller effect on the level of atmospheric carbon dioxide.   . ...   . ...   . .  [2]",
            "8": "8 0620/32/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (iii)  a method being developed to produce iron with lower emissions of carbon dioxide  is by electrolysis. hematite, fe2o3, is dissolved in molten lithium carbonate and  electrolysed. the ore is spilt into its constituent elements.   write an equation for the reaction at the negative electrode (cathode).   . ...   complete the equation for the reaction at the positive electrode (anode).  o2\u2013  \u2192  ...  +  ... [3] [total: 13]",
            "9": "9 0620/32/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use5  silver( i) chromate( vi) is an insoluble salt. it is prepared by precipitation.   20  cm3 of aqueous silver( i) nitrate, concentration 0.2  mol  / dm3, was mixed with 20  cm3 of  aqueous potassium chromate( vi), concentration 0.1  mol  / dm3. after stirring, the mixture was  \ufb01 ltered. the precipitate was washed several times with distilled water. the precipitate was  then left in a warm oven for several hours. 2agno3(aq)  +  k2cro4(aq)  \u2192  ag2cro4(s)  +  2kno3(aq)  (a)  what dif \ufb01 culty arises if the name of a compound of a transition element does not include  its oxidation state, for example iron oxide?   ...    ... ..  [2]  (b)  these questions refer to the preparation of the salt.  (i)  why is it necessary to \ufb01 lter the mixture after mixing and stirring?   . .  [1]  (ii)  what is the purpose of washing the precipitate?   . .  [1]  (iii)  why leave the precipitate in a warm oven?   . .  [1]  (c) (i)   explain why the concentrations of silver( i) nitrate and potassium chromate( vi) are  different.   . .  [1]  (ii)  what mass of silver( i) nitrate is needed to prepare 100  cm3 of silver( i) nitrate solution,  concentration 0.2  mol  / dm3?   the mass of one mole of agno3 is 170  g.   . ...   . .  [2]  (iii)  what is the maximum mass of silver( i) chromate( vi) which could be obtained from  20  cm3 of aqueous silver( i) nitrate, concentration 0.2  mol  / dm3?  number of moles of agno3 used = . [1]  number of moles of ag2cro4 formed = . [1]  mass of one mole of ag2cro4 = 332  g  mass of ag2cro4 formed = . g [1] [total: 11]",
            "10": "10 0620/32/o/n/13 \u00a9 ucles 2013for examiner\u2019s use6  the following reactivity series shows both familiar and unfamiliar elements in order of  decreasing reactivity. each element is represented by a redox equation.  rb   rb+  +  e\u2013  mg   mg2+  +  2e\u2013  mn   mn2+  +  2e\u2013  zn   zn2+  +  2e\u2013  h2   2h+  +  2e\u2013  cu   cu2+  + 2e\u2013  hg   hg2+  + 2e\u2013   two of the uses of the series are to predict the thermal stability of compounds of the metals  and to explain their redox reactions.  (a)  most metal hydroxides decompose when heated.  (i)  complete the equation for the thermal decomposition of copper( ii) hydroxide.  cu(oh)2  \u2192  ...  +  ... [1]  (ii)  choose a metal from the above series whose hydroxide does not decompose when  heated.   . .  [1]  (b) (i)   de\ufb01 ne in terms of electron transfer the term oxidation .   . .  [1]  (ii)  explain why the positive ions in the above equations are oxidising agents.   . ...   . .  [1]  (c) (i)   which metals in the series above do not react with dilute acids to form hydrogen?   . .  [1]  (ii)  describe an experiment which would con \ufb01 rm the prediction made in (c)(i) .   . ...   . .  [1]  (d) (i)   which metal in the series above can form a negative ion which gives a pink  / purple  solution in water?   . .  [1]  (ii)  describe what you would observe when zinc, a reducing agent, is added to this  pink  / purple solution.   . .  [1] [total: 8]",
            "11": "11 0620/32/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use7  plants can make complex molecules from simple starting materials, such as water, carbon  dioxide and nitrates. substances produced by plants include sugars, more complex carbohydrates, esters, proteins, vegetable oils and fats.  (a) (i)   describe how you could decide from its molecular formula whether a compound is a  carbohydrate.   . ...   . .  [2]  (ii)  plants can change the sugar, glucose, into starch which is a more complex  carbohydrate.  what type of reaction is this?   . .  [2]  (b)  the fermentation of glucose can be carried out in the apparatus shown below. after a few  days the reaction stops. a 12% aqueous solution of ethanol has been produced. water allows carbondioxide to escape butprevents air from entering aqueous glucose and yeast  (i)  the enzyme, zymase, catalyses the anaerobic respiration of the yeast.  explain the term respiration .   . ...   . .  [2]  (ii)  complete the equation.  c6h12o6   \u2192   .  +  ... [2]  glucose ethanol carbon dioxide  (iii)  why must air be kept out of the \ufb02 ask?   . .  [1]",
            "12": "12 0620/32/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (c)  the ester methyl butanoate is found in apples. it can be made from butanoic acid and  methanol. their structural formulae are given below. ch hco o hch hch hh h o ch hh butanoic acid methanol   use the information given above to deduce the structural formula of methyl butanoate  showing all the bonds. [2]  (d)  the equation represents the hydrolysis of a naturally occurring ester. c17h35 co2ch2 c17h35 co2 3c17h35coona choh ch 3naoh ++ \u2192 c17h35 co2ch2ch2oh ch2oh  (i)  which substance in the equation is an alcohol? put a ring around this substance in  the equation above. [1]  (ii)  is the alkyl group, c17h35, in this ester saturated or unsaturated? give a reason for  your choice.   . .  [1]  (iii)  what type of compound is represented by the formula c17h35coona?  what is the major use for compounds of this type?  type of compound  .. use  ...  [2]",
            "13": "13 0620/32/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (e)  proteins are natural macromolecules. draw the structural formula of a typical protein.   include three monomer units. you may represent amino acids by formulae of the type drawn below. h2n cooh h2n cooh [3] [total: 18]",
            "14": "14 0620/32/o/n/13blank page \u00a9 ucles 2013",
            "15": "15 0620/32/o/n/13blank page \u00a9 ucles 2013",
            "16": "16 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/32/o/n/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w13_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) october/november 2013  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib13 11_0620_33/3rp\u00a9 ucles 2013 *1277729958*",
            "2": "2 0620/33/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1  zirconium (zr) is a metal in period 5. its main oxidation state is +4.  (a)  the following are all zirconium atoms: 90zr40, 91zr40 and 92zr40.   in terms of numbers of electrons, neutrons and protons, how are these three atoms the  same and how are they different?   they are the same because  .   ...    they are different because  ...   ... ..  [3]  (b)  containers for fuel rods in nuclear reactors are made of zirconium.   nuclear reactors are used to produce energy and to make radioactive isotopes.  (i)  which isotope of a different element is used as a fuel in nuclear reactors?   . .  [1]  (ii)  state one medical and one industrial use of radioactive isotopes.   . ...   . .  [2]  (iii)  above 900  \u00b0c, zirconium reacts with water to form zirconium( iv) oxide, zro2, and  hydrogen.  write an equation for this reaction.   . .  [2]  (iv)  in a nuclear accident, water may come in contact with very hot zirconium.   explain why the presence of hydrogen inside the reactor greatly increases the  danger of the accident.   . .  [1]  (c)  it is possible to determine whether zirconium( iv) oxide is acidic, neutral, basic or  amphoteric using an acid and an alkali. complete the table of possible results. if the oxide is predicted to react write \u2018r\u2019, if it is predicted not to react write \u2018nr\u2019. if the oxide ispredicted result with hydrochloric acidpredicted result with aqueous sodium hydroxide acidic neutral basic amphoteric [4] [total: 13]",
            "3": "3 0620/33/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2 (a)  the diagram shows the lattice of a typical ionic compound. \u2013 + \u2013+ \u2013\u2013 + \u2013 ++ \u2013 +\u2013 + \u2013 + +\u2013 \u2013\u2013 + ++ \u2013  (i)  explain the term ionic lattice .   . ...   . .  [2]  (ii)  in this lattice, the ratio of positive ions to negative ions is 1:1.   in the lattice of a different ionic compound, the ratio of positive ions to negative ions  is 1:2.   suggest why this ratio varies in different ionic compounds.   . .  [1]  (iii)  give three  physical properties of ionic compounds.   . ...   . ...   . .  [3]  (b)  strontium oxide is an ionic compound. draw a diagram which shows its formula, the  charges on the ions and the arrangement of the valency  electrons around the negative  ion.   the electron distribution of a strontium atom is 2 + 8 + 18 + 8 + 2.   use o to represent an electron from a strontium atom.   use x to represent an electron from an oxygen atom. [3] [total: 9]",
            "4": "4 0620/33/o/n/13 \u00a9 ucles 2013for examiner\u2019s use3  the main uses of zinc are preventing steel from rusting and making alloys.  (a)  the main ore of zinc is zinc blende. zinc blende consists mainly of zinc sul \ufb01 de, zns.  there are two major methods of extracting zinc from its ore. they are the direct reduction of zinc oxide to zinc and by electrolysis. in both methods, zinc oxide is made from the zinc sul \ufb01 de in the ore.  (i)  how is zinc oxide made from zinc sul \ufb01 de?   . ...   . .  [1]  (ii)  write an equation for the reaction used to reduce zinc oxide to zinc.   . .  [1]  (b)  in the electrolytic method, zinc oxide reacts with sulfuric acid to form impure aqueous  zinc sulfate. this solution contains ni 2+, co2+ and cu2+ ions as impurities.  (i)  write the equation for the reaction between zinc oxide and sulfuric acid.   . .  [1]  (ii)  nickel, cobalt and copper are all less reactive than zinc. explain why the addition of  zinc powder removes these ions from the solution.   . ...   . .  [2]  (c)  the solution of zinc sulfate is electrolysed using inert electrodes.   this electrolysis is similar to that of copper( ii) sulfate with inert electrodes.  (i)  write the equation for the reaction at the negative electrode (cathode).   . .  [1]  (ii)  complete the equation for the reaction at the positive electrode (anode).  .oh\u2013  \u2192  2h2o  +  .  +  .e\u2013 [2]  (iii)  the electrolyte changes from zinc sulfate to   . .  [1]",
            "5": "5 0620/33/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (d) (i)   brass is an alloy of copper and zinc. suggest two reasons why brass is often used  in preference to copper.   . ...   . .  [2]  (ii)  sacri \ufb01 cial protection is a method of rust prevention. explain in terms of electron  transfer why steel, which is in electrical contact with zinc, does not rust.   . ...   . ...   . ...   . .  [4] [total: 15]",
            "6": "6 0620/33/o/n/13 \u00a9 ucles 2013for examiner\u2019s use4  sulfuric acid is a strong acid. hexanesulfonic acid is also a strong acid. it has similar properties  to sulfuric acid.  (a)  sulfonic acids are made from alkanes and oleum, h2s2o7. c6h14  +  h2s2o7  \u2192  c6h13so3h  +  h2so4  (i)  describe how oleum is made from sulfur by the contact process. give equations  and reaction conditions.   . ...   . ...   . ...   . ...   . ...   . ...   . .  [6]  (ii)  how is concentrated sulfuric acid made from oleum?   . .  [1]  (b)  the formula of the hexanesulfonate ion is c6h13so3\u2013.   the formula of the barium ion is ba2+. what is the formula of barium hexanesulfonate?   ... ..  [1]  (c)  complete the following equations.  (i)  magnesium  +  hexanesulfonic  \u2192  .  +  .  acid . [1]  (ii) calcium  +  hexanesulfonic  \u2192  .  +  .  oxide acid . [1]  (iii) .c6h13so3h  +  na2co3  \u2192  .  +    +   [2]",
            "7": "7 0620/33/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (d) (i)  sulfuric acid is a strong acid.   you are given aqueous sulfuric acid, concentration 0.1  mol  / dm3, and aqueous  hexanesulfonic acid, concentration 0.2  mol  / dm3. describe how you could show that  hexanesulfonic acid is also a strong acid.   . ...   . .  [2]  (ii)  deduce why, for a fair comparison, the two acid solutions must have different  concentrations.   . ...   . .  [1]  (iii)  explain the terms strong acid  and weak acid .   . ...   . ...   . .  [2] [total: 17]",
            "8": "8 0620/33/o/n/13 \u00a9 ucles 2013for examiner\u2019s use5  domestic rubbish is disposed of in land \ufb01 ll sites. rubbish could include the following items. item of rubbishapproximate time for item to break down newspaper one month cotton rag six months woollen glove one year aluminium container up to 500 years styrofoam cup 1000 years  (a)  explain why aluminium, a reactive metal, takes so long to corrode.   ... ..  [1]  (b)  both paper and cotton are complex carbohydrates. they can be hydrolysed to simple  sugars such as glucose.   the formula of glucose can be represented as: ho oh   draw the structural formula of a complex carbohydrate, such as cotton.   include at least two glucose units. [2]",
            "9": "9 0620/33/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  wool is a protein. it can be hydrolysed to a mixture of monomers by enzymes.  (i)  what are enzymes?   . ...   . .  [2]  (ii)  name another substance which can hydrolyse proteins.   . .  [1]  (iii)  what type of compound are the monomers formed by the hydrolysis of proteins?   . .  [1]  (iv)  which technique could be used to identify the individual monomers in the mixture?   . .  [1]  (v)  proteins contain the amide linkage. name a synthetic macromolecule which contains  the same linkage.   . .  [1]  (d) (i)   what is the scienti \ufb01 c term used to describe polymers which do not break down in  land \ufb01 ll sites?   . .  [1]  (ii)  styrofoam is poly(phenylethene). it is an addition polymer. its structural formula is  given below. deduce the structural formula of the monomer, phenylethene. nch2ch c6h5 [1] [total: 11]",
            "10": "10 0620/33/o/n/13 \u00a9 ucles 2013for examiner\u2019s use6  the alcohols form a homologous series. the \ufb01 rst \ufb01 ve members are given in the table below.  (a) alcohol formulaheat of combustion in kj  / mol methanol ch3oh 730 ethanol ch3\u2013ch2\u2013oh 1380 propan-1-ol butan-1-ol ch3\u2013ch2\u2013ch2\u2013ch2\u2013oh 2680 pentan-1-ol ch3\u2013ch2\u2013ch2\u2013ch2\u2013ch2\u2013oh 3350  (i)  complete the table. [2]  (ii)  complete the equation for the combustion of pentan-1-ol in excess oxygen.  c5h11oh  +  ...o2  \u2192  .  +  . [1]  (b)  state three  characteristics of a homologous series other than the variation of physical  properties down the series.   ...    ...    ... ..  [3]  (c)  the following alcohols are isomers. ch3\u2013ch2\u2013ch2\u2013ch2\u2013oh   and   (ch3)2ch\u2013ch2\u2013oh  (i)  explain why they are isomers.   . ...   . ...   . .  [2]  (ii)  draw the structural formula of another isomer of the above alcohols. [1]",
            "11": "11 0620/33/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (d)  alcohols can be made by fermentation and from petroleum.  (i)  ethanol is made from sugars by fermentation. c6h12o6  \u2192  2c2h5oh  +  2co2   the mass of one mole of glucose, c6h12o6, is 180  g.   calculate the maximum mass of ethanol which could be obtained from 72  g of  glucose.   . ...   . ...   . ...   . .  [3]  (ii)  describe how ethanol is made from petroleum. petroleum (alkanes)  \u2192  ethene  \u2192  ethanol   . ...   . ...   . ...   . .  [3] [total: 15]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/33/o/n/13 \u00a9 ucles 2013 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w13_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.practical notes are provided on page 8.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test october/november 2013  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib13 11_0620_51/2rp\u00a9 ucles 2013 *1146292889* for examiner\u2019s use total",
            "2": "2 0620/51/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1  you are going to investigate what happens when aqueous sodium hydroxide reacts with acid k.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   use a measuring cylinder to pour 25  cm3 of acid k into a conical \ufb02 ask. add \ufb01 ve drops of  phenolphthalein to the \ufb02 ask.   fill the burette with the aqueous sodium hydroxide to the 0.0  cm3 mark.   slowly add the aqueous sodium hydroxide to acid k in the \ufb02 ask and shake the mixture.   continue to add aqueous sodium hydroxide to the \ufb02 ask until the solution shows a  permanent colour change.   measure and record the volume in the table. complete the table.   pour the solution away and rinse the conical \ufb02 ask. burette reading \ufb01 nal volume  / cm3 initial volume  / cm3 difference  / cm3 [3]  (b)  experiment 2   use a measuring cylinder to pour 50  cm3 of acid k into a conical \ufb02 ask. add the 0.3  g of  powdered calcium carbonate to the \ufb02 ask and shake the \ufb02 ask until no further reaction is  observed.   add \ufb01 ve drops of phenolphthalein to the mixture in the \ufb02 ask.   fill the burette with aqueous sodium hydroxide and record the burette reading. slowly add  aqueous sodium hydroxide from the burette to the \ufb02 ask and shake the mixture. continue  to add aqueous sodium hydroxide to the \ufb02 ask until the solution shows a permanent  colour change.   measure and record the volume in the table. complete the table. burette reading \ufb01 nal volume  / cm3 initial volume  / cm3 difference  / cm3 [3]",
            "3": "3 0620/51/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  what colour change was observed after the sodium hydroxide solution was added to the  \ufb02 ask?  from  to . ... [2]  (d)  what type of chemical reaction occurs when acid k reacts with sodium hydroxide?   ... ..  [1]  (e)  if experiment 1 was repeated using 50  cm3 of acid k, what volume of sodium hydroxide  would be required to change the colour of the indicator?   ... ..  [2]  (f) (i)   what is the effect of adding 0.3  g of powdered calcium carbonate to acid k?   . ...   . .  [2]  (ii)  use your answers from (b) and (e) to work out the difference in the volume of sodium  hydroxide added when 0.3  g of calcium carbonate is mixed with 50  cm3 of acid k in  experiment 2.   . ...   . .  [2]  (iii)  estimate the mass of calcium carbonate that would need to be added to 50  cm3 of  acid k to require 0.0  cm3 of sodium hydroxide. [1]  (g)  what would be the effect on the results if the solutions of acid k were warmed before  adding the sodium hydroxide? give a reason for your answer.   effect on results     reason  .  [2]",
            "4": "4 0620/51/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (h)  suggest the advantage, if any, of  (i)  using a pipette to measure the volume of acid k.   . ...   . .  [2]  (ii)  using a polystyrene cup instead of a \ufb02 ask.   . ...   . .  [2] [total: 22]",
            "5": "5 0620/51/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  you are provided with two liquids, l and m.   carry out the following tests on l and m, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on liquid l (a)  describe the appearance of liquid l.   [1] divide liquid l into \ufb01 ve equal portions in  separate test-tubes. (b) (i)   add the \ufb01 rst portion of liquid l to  the test-tube containing the iodine  crystal. stopper the test-tube and shake the contents.    now add an equal volume of liquid m  to the test-tube, stopper and shake  the contents. leave to stand for \ufb01 ve  minutes and continue to part (c).  (ii)   after \ufb01 ve minutes, remove most of  the top layer using a teat pipette and  add ethanol to the liquid which you have removed. stopper the test-tube and shake the contents. leave to stand for \ufb01 ve minutes.  [1]  ..   [2]  ..   [2] (c)  to the second portion of liquid l, add a  few drops of dilute nitric acid and about  1  cm3 of barium nitrate solution.   [1] (d)  to the third portion of liquid l, add a few  drops of dilute nitric acid and about 1  cm3  of silver nitrate solution.   [2] (e)  to the fourth portion of liquid l, add about  1 cm3 of aqueous copper sulfate, shake  and leave to stand for \ufb01 ve minutes. ..   [2] (f)  to the \ufb01 fth portion of liquid l, add about  2 cm3 of aqueous hydrogen peroxide.   now add about 1  cm3 of starch solution. ..  [3]",
            "6": "6 0620/51/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (g)  why does the colour of liquid l change in test (b)(i) ?   ...    ... ..  [1]  (h)  what conclusions can you draw about liquid m from test (b)(i) ?   ...    ... ..  [2]  (i)  what conclusions can you draw about liquid l?   ...    ...    ... ..  [1] [total: 18]",
            "7": "7 0620/51/o/n/13blank page \u00a9 ucles 2013",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/51/o/n/13notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2013"
        },
        "0620_w13_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.practical notes are provided on page 8.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test october/november 2013  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib13 11_0620_52/fp\u00a9 ucles 2013 *6686368564* for examiner\u2019s use total",
            "2": "2 0620/52/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1  you are going to investigate what happens when aqueous sodium hydroxide reacts with acid k.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   use a measuring cylinder to pour 25  cm3 of acid k into a conical \ufb02 ask. add \ufb01 ve drops of  phenolphthalein to the \ufb02 ask.   fill the burette with the aqueous sodium hydroxide to the 0.0  cm3 mark.   slowly add the aqueous sodium hydroxide to acid k in the \ufb02 ask and shake the mixture.   continue to add aqueous sodium hydroxide to the \ufb02 ask until the solution shows a  permanent colour change.   measure and record the volume in the table. complete the table.   pour the solution away and rinse the conical \ufb02 ask. burette reading \ufb01 nal volume  / cm3 initial volume  / cm3 difference  / cm3 [3]  (b)  experiment 2   use a measuring cylinder to pour 50  cm3 of acid k into a conical \ufb02 ask. add the 0.3  g of  powdered calcium carbonate to the \ufb02 ask and shake the \ufb02 ask until no further reaction is  observed.   add \ufb01 ve drops of phenolphthalein to the mixture in the \ufb02 ask.   fill the burette with aqueous sodium hydroxide and record the burette reading. slowly add  aqueous sodium hydroxide from the burette to the \ufb02 ask and shake the mixture. continue  to add aqueous sodium hydroxide to the \ufb02 ask until the solution shows a permanent  colour change.   measure and record the volume in the table. complete the table. burette reading \ufb01 nal volume  / cm3 initial volume  / cm3 difference  / cm3 [3]",
            "3": "3 0620/52/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  what colour change was observed after the sodium hydroxide solution was added to the  \ufb02 ask?  from  to . ... [2]  (d)  what type of chemical reaction occurs when acid k reacts with sodium hydroxide?   ... ..  [1]  (e)  if experiment 1 was repeated using 50  cm3 of acid k, what volume of sodium hydroxide  would be required to change the colour of the indicator?   ... ..  [2]  (f) (i)   what is the effect of adding 0.3  g of powdered calcium carbonate to acid k?   . ...   . .  [2]  (ii)  use your answers from (b) and (e) to work out the difference in the volume of sodium  hydroxide added when 0.3  g of calcium carbonate is mixed with 50  cm3 of acid k in  experiment 2.   . ...   . .  [2]  (iii)  estimate the mass of calcium carbonate that would need to be added to 50  cm3 of  acid k to require 0.0  cm3 of sodium hydroxide. [1]  (g)  what would be the effect on the results if the solutions of acid k were warmed before  adding the sodium hydroxide? give a reason for your answer.   effect on results     reason  .  [2]",
            "4": "4 0620/52/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (h)  suggest the advantage, if any, of  (i)  using a pipette to measure the volume of acid k.   . ...   . .  [2]  (ii)  using a polystyrene cup instead of a \ufb02 ask.   . ...   . .  [2] [total: 22]",
            "5": "5 0620/52/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  you are provided with two liquids, l and m.   carry out the following tests on l and m, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on liquid l (a)  describe the appearance of liquid l.   [1] divide liquid l into \ufb01 ve equal portions in  separate test-tubes. (b) (i)   add the \ufb01 rst portion of liquid l to  the test-tube containing the iodine  crystal. stopper the test-tube and shake the contents.    now add an equal volume of liquid m  to the test-tube, stopper and shake  the contents. leave to stand for \ufb01 ve  minutes and continue to part (c).  (ii)   after \ufb01 ve minutes, remove most of  the top layer using a teat pipette and  add ethanol to the liquid which you have removed. stopper the test-tube and shake the contents. leave to stand for \ufb01 ve minutes.  [1]  ..   [2]  ..   [2] (c)  to the second portion of liquid l, add a  few drops of dilute nitric acid and about  1  cm3 of barium nitrate solution.   [1] (d)  to the third portion of liquid l, add a few  drops of dilute nitric acid and about 1  cm3  of silver nitrate solution.   [2] (e)  to the fourth portion of liquid l, add about  1 cm3 of aqueous copper sulfate, shake  and leave to stand for \ufb01 ve minutes. ..   [2] (f)  to the \ufb01 fth portion of liquid l, add about  2 cm3 of aqueous hydrogen peroxide.   now add about 1  cm3 of starch solution. ..  [3]",
            "6": "6 0620/52/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (g)  why does the colour of liquid l change in test (b)(i) ?   ...    ... ..  [1]  (h)  what conclusions can you draw about liquid m from test (b)(i) ?   ...    ... ..  [2]  (i)  what conclusions can you draw about liquid l?   ...    ...    ... ..  [1] [total: 18]",
            "7": "7 0620/52/o/n/13blank page \u00a9 ucles 2013",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/52/o/n/13notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2013"
        },
        "0620_w13_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.practical notes are provided on page 8.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test october/november 2013  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionsuniversity of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 6 printed pages and 2 blank pages. [turn overib13 11_0620_53/2rp\u00a9 ucles 2013 *7606081731* for examiner\u2019s use total",
            "2": "2 0620/53/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1  you are going to investigate the reaction between aqueous potassium manganate( vii),  solution c, and two different acidic solutions, d and e.   read all the instructions below carefully before starting the experiments.  instructions   you are going to carry out three experiments.  (a)  experiment 1   fill the burette with the solution c of potassium manganate( vii) to the 0.0  cm3 mark.  using a measuring cylinder, pour 25  cm3 of solution d into the conical \ufb02 ask.   add 1.0  cm3 of the solution c to the \ufb02 ask, with shaking. continue to add solution c to the  \ufb02 ask until the mixture just turns permanently pink. record the burette reading in the table  and complete the table.   pour away the contents of the conical \ufb02 ask and rinse the \ufb02 ask with distilled water. burette reading \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]  (b)  experiment 2   repeat experiment 1 using 25  cm3 of solution e instead of solution d.   record the burette readings in the table and complete the table. burette reading \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]  (c)  experiment 3   to about 2  cm3 of solution e in a test-tube, add an equal volume of aqueous ammonia.  shake the test-tube and note any observations. leave the mixture to stand for 5 minutes  and note any changes.   ...    ... ..  [2]",
            "3": "3 0620/53/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (d) (i)   what colour change was observed as potassium manganate( vii) solution was  added to the \ufb02 ask in experiment 1?   . ...[1]  (ii)  why is an indicator not added to the \ufb02 ask?   . .  [1]  (e) (i)   in which experiment was the greatest volume of potassium manganate( vii) solution  used?   . .  [1]  (ii)  compare the volumes of potassium manganate( vii) used in experiments 1 and 2.   . .  [1]  (iii)  suggest an explanation for the difference in volumes.   . ...   . ...   . .  [2]  (f)  if experiment 2 was repeated using 12.5  cm3 of solution e, what volume of potassium  manganate( vii) solution would be used? explain your answer.   ...    ... ..  [2]  (g)   give one advantage and one disadvantage of using a measuring cylinder for solutions  d and e.  advantage  ... ..  disadvantage ...  [2]  (h)  explain your observations in experiment 3.   ...    ... ..  [3] [total: 21]",
            "4": "4 0620/53/o/n/13 \u00a9 ucles 2013for examiner\u2019s use2  you are provided with liquid f.   carry out the following tests on the liquid, recording all of your observations in the table.   conclusions must not be written in the table. tests observations divide liquid f into \ufb01 ve equal portions in  separate test-tubes. (a)  describe the appearance of liquid f.   test the ph of the liquid.   to the \ufb01 rst portion of liquid f, add an  equal volume of dilute sulfuric acid.   now add excess aqueous sodium  hydroxide and shake the mixture.  [1]   [1]  ..   [2] (b)  to the second portion of liquid f, add  an equal volume of dilute sulfuric acid  followed by about 2  cm3 of hydrogen  peroxide.   shake the mixture and test the gas given off with a splint. ..   [1]   [2] (c)  to the third portion of liquid f, add  aqueous silver nitrate followed by excess  dilute nitric acid. shake the mixture. ..   [3] (d)  to the fourth portion of liquid f, add  aqueous barium nitrate followed by  excess dilute nitric acid. shake the mixture. ..   [3] (e)  to the \ufb01 fth portion of liquid f, add an  equal volume of sulfuric acid and one  spatula measure of iron \ufb01 lings. ..   [2]",
            "5": "5 0620/53/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (f)  what type of reaction happened in test (a)? explain your answer.  type of reaction   .  explanation  . ..   ... ..  [2]  (g)  identify the gas given off in test (b).   ... ..  [1]  (h)  draw one conclusion about liquid f.   ... ..  [1] [total: 19]",
            "6": "6 0620/53/o/n/13blank page \u00a9 ucles 2013",
            "7": "7 0620/53/o/n/13blank page \u00a9 ucles 2013",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/53/o/n/13notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2013"
        },
        "0620_w13_qp_61.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical october/november 2013  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib13 11_0620_61/2rp\u00a9 ucles 2013 *8106479956*",
            "2": "2 0620/61/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1  a student investigated the products formed when ethanol was burned using the apparatus  shown. suctionpump liquid f  (a)  complete the box to identify the piece of apparatus. [1]  (b)  why is a suction pump used?   ... ..  [1]  (c) (i)  suggest the purpose and identity of liquid f.  identity   ...  purpose    [2]  (ii)  why is the end of the delivery tube below the surface of liquid f?   . ...   . .  [1]  (d)  give one expected observation in the horizontal part of the delivery tube.   explain your answer.   ...    ... ..  [2] [total: 7]",
            "3": "3 0620/61/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  eight steel rods of the same size were placed in solutions of different ph for one week.   the percentage corrosion of the rods was measured and the results plotted on the grid below. 30 20 10 0percentage corrosion of steel rod 01234 ph of solution5678  (a)  draw a best \ufb01 t straight line through the points. [1]  (b)  why were the steel rods the same size?   ... ..  [1]  (c)  state one other variable which should have been kept constant.   ... ..  [1]  (d)  state one conclusion that could be drawn from the results.   ... ..  [1]  (e)  determine the percentage corrosion of a steel rod in a solution of ph 6.5.   ... ..  [1] [total: 5]",
            "4": "4 0620/61/o/n/13 \u00a9 ucles 2013for examiner\u2019s use3  a student investigated the reaction between aqueous sodium hydroxide and acid k.   two experiments were carried out.  (a)   experiment 1   using a measuring cylinder, 25  cm3 of acid k was poured into a conical \ufb02 ask.  phenolphthalein indicator was added to the \ufb02 ask. a burette was \ufb01 lled with aqueous  sodium hydroxide to the 0.0  cm3 mark. aqueous sodium hydroxide was added from the  burette to the \ufb02 ask and the mixture shaken until the solution showed a permanent colour  change.   the \ufb01 nal volume was measured. use the burette diagram to record the \ufb01 nal volume in  the table and complete the table. 37 38 39 final volume burette reading final volume  / cm3 initial volume  / cm3 difference  / cm3 [2]  (b)  experiment 2   the solution was poured away and the conical \ufb02 ask rinsed.   using a measuring cylinder, 50  cm3 of acid k was poured into the conical \ufb02 ask. 0.3  g of  powdered calcium carbonate was added to the \ufb02 ask and the \ufb02 ask shaken until no further  reaction was observed.   phenolphthalein was added to the mixture in the \ufb02 ask.   a burette was \ufb01 lled with the same aqueous sodium hydroxide and the initial volume  measured. aqueous sodium hydroxide was added from the burette to the \ufb02 ask and the  mixture shaken until the solution showed a permanent colour change.   use the burette diagrams to record the initial and \ufb01 nal volumes in the table and complete  the table. initial volume final volume28 29 309 10 11 burette reading final volume  / cm3 initial volume  / cm3 difference  / cm3 [2]",
            "5": "5 0620/61/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  what colour change was observed after the sodium hydroxide solution was added to the  \ufb02 ask?   from   to . ...  [2]  (d)  what type of chemical reaction occurred when acid k reacted with sodium hydroxide?   ... ..  [1]  (e)  if experiment 1 were repeated using 50  cm3 of acid k, what volume of sodium hydroxide  would be required to change the colour of the indicator?   ... ..  [2]  (f) (i)   what were the effects of adding 0.3  g of powdered calcium carbonate to acid k?   . ...   . .  [2]  (ii)  use your answer in (e) to work out the difference between the volume of sodium  hydroxide needed to completely react with 50  cm3 of acid k and the volume of  sodium hydroxide used in experiment 2.   . ...   . .  [2]  (iii)  estimate the mass of calcium carbonate that would be needed to be added to 50  cm3  of acid k to require 0.0  cm3 of sodium hydroxide.   . .  [1]  (g)  what would be the effect on the results if the solutions of acid k were warmed before  adding the sodium hydroxide? give a reason for your answer.  effect on results  ... .  reason  .  [2]",
            "6": "6 0620/61/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (h)  suggest the advantage, if any, of  (i)  using a pipette to measure the volume of acid k.   . ...   . .  [2]  (ii)  using a polystyrene cup instead of a \ufb02 ask.   . ...   . .  [2] [total: 20]",
            "7": "7 0620/61/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use4  two liquids, l and m, were analysed. l was aqueous potassium iodide. m was a colourless  liquid.   the tests on the liquids and some of the observations are in the following table.   complete the observations in the table. tests observations tests on liquid l (a) appearance of liquid l.   [1] liquid l was divided into three equal portions  in separate test-tubes. (b) (i)  an iodine crystal was added to the \ufb01 rst  portion of liquid l. the test-tube was  stoppered and the contents shaken.  (ii)  an equal volume of liquid m was added  to the test-tube, the contents shaken  and left to stand for \ufb01 ve minutes.liquid turned orange two layers were formed, pink top layer and orange lower layer (c)  to the second portion of liquid l, dilute  nitric acid and barium nitrate solution were added.   [1] (d)  to the third portion of liquid l, dilute nitric  acid and silver nitrate solution were added.   [2]  (e)  why does the colour of liquid l change in test (b)(i) ?   ...    ... ..  [1]  (f)  what conclusions can you draw about liquid m from test (b)(ii) ?   ...    ... ..  [2] [total: 7]",
            "8": "8 0620/61/o/n/13 \u00a9 ucles 2013for examiner\u2019s use5  two experiments using catalysts were carried out. catalysts r and s were used to break  down 50  cm3 of aqueous hydrogen peroxide at a temperature of 20  \u00b0c. the volume of oxygen  given off was measured using the apparatus shown. aqueoushydrogen peroxide catalystgas syringe   the gas syringe diagrams show the volume of oxygen formed every 30 seconds in each  experiment.  (a)  use the syringe diagrams to complete the volumes in the table. time  / s syringe diagramusing catalyst r using catalyst s volume  / cm3syringe diagram volume  / cm3 01 00 20 30 40 30 40 50 50 60 70 60 70 80 60 70 80 60 70 8001 0 10 20 30 30 40 50 50 60 70 60 70 80 60 70 80 60 70 8030 60 90 120150 180 [4]",
            "9": "9 0620/61/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b)  plot a graph to show each set of results. clearly label the graphs r and s. 80 70605040302010 0volume of oxygen  / cm3 0 3 06 09 0 1 2 0 time  / s150 180 [6]  (c)  which result using catalyst r was inaccurate?   ... ..  [1]  (d)  which is the better catalyst in this reaction? explain your answer.   ...    ... ..  [2]  (e)  sketch a line on the grid to show the graph you would expect if the reaction with catalyst  r was repeated at 50  \u00b0c. [2] [total: 15]",
            "10": "10 0620/61/o/n/13 \u00a9 ucles 2013for examiner\u2019s use6 old documents   some documents are stored in containers with packets of silica gel crystals. these crystals  absorb water from air that enters the container. water could damage the documents.   anhydrous cobalt( ii) chloride is added to the silica gel. as the crystals absorb water they  change colour from blue to pink. heating the silica gel in an oven removes the water from the crystals so that the crystals can be reused.   plan an experiment to \ufb01 nd the mass of water absorbed by a packet of silica gel crystals.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [6] [total: 6]",
            "11": "11 0620/61/o/n/13blank page \u00a9 ucles 2013",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/61/o/n/13blank page \u00a9 ucles 2013"
        },
        "0620_w13_qp_62.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical october/november 2013  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib13 11_0620_62/2rp\u00a9 ucles 2013 *4045280680*",
            "2": "2 0620/62/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1  alkenes can be made by cracking long chain alkanes. a student used the apparatus below to  demonstrate cracking. broken tileliquid alkane on mineral wool very strong heat water  (a)  complete the box to show the apparatus used. [1]  (b)  indicate with an arrow where the alkenes are collected. [1]  (c)  suggest the purpose of the mineral wool.   ... ..  [1]  (d)  why are small  pieces of broken tile used?   ...    ... ..  [1]  (e)  describe a test to show that alkenes have been made.  test     result  .. .  [2] [total: 6]",
            "3": "3 0620/62/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  substance m is a mixture of four dyes. three of the dyes have different solubilities in  propanone. the fourth dye is insoluble in propanone.  (a)  name the process that could be used to separate these dyes.   ... ..  [1]  (b)  sketch on the right hand diagram the results you would expect if m was analysed as  shown. base-line propanone at the beginning at the endm [2]  (c)  why is the base-line not drawn in ink?   ...    ... ..  [1]  (d)  why must the level of the propanone be below the base-line?   ... ..  [1] [total: 5]",
            "4": "4 0620/62/o/n/13 \u00a9 ucles 2013for examiner\u2019s use3  a student investigated the formation of calcium oxide by heating calcium in air, using the  apparatus shown. heatcrucible   she weighed an empty crucible and its lid. she then added some calcium to the crucible and reweighed it.  (a)  use the balance diagrams to record the masses in the table. balance diagram mass  / g mass of crucible and lid32 31 mass of crucible, lid and calcium3231 [1]   the student then heated the calcium in the crucible for ten minutes. the lid was raised  occasionally using a pair of tongs. after ten minutes, the crucible was allowed to cool and reweighed. this procedure was repeated twice.  (b)  use the balance diagrams to complete the table of results. time  / min 10 20 30 balance diagram32 3133323332 mass of crucible, lid  and calcium oxide  / g [2]",
            "5": "5 0620/62/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  why was the lid of the crucible raised occasionally?   ... ..  [1]  (d)  explain why the crucible was heated three times.   ...    ... ..  [2]   the table shows the results of experiments using different masses of calcium. experimentmass of calcium  / gmass of calcium oxide  / gmass of oxygen reacted  / g 1 0.12 0.20 0.08 2 0.20 0.32 0.123 0.30 0.49 0.194 0.40 0.615 0.44 0.726 0.48 0.797 0.56 0.92  (e)  complete the table of results. [1]  (f)  plot the results on the grid and draw a straight line graph. 0.5 0.40.30.20.10.0 0.0 0.1 0.2 0.3 0.4 mass of calcium  / g0.5 0.6 0.7mass of oxygen reacted  / g [5]",
            "6": "6 0620/62/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (g)  which result is inaccurate?   ... ..  [1]  (h)  use your graph  to work out the mass of calcium oxide formed when 0.7  g of calcium is  heated in air. show clearly on the grid how you used your graph. [3] [total: 16]",
            "7": "7 0620/62/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use4  a student investigated what happened when dilute hydrochloric acid and aqueous copper( ii)  sulfate solution reacted with different metals.   five experiments were carried out.  (a)  experiment 1   using a measuring cylinder 10  cm3 of dilute hydrochloric acid was poured into a boiling  tube. the temperature of the solution was measured.   1 g of zinc powder was added to the boiling tube and the mixture stirred with the  thermometer. the maximum temperature of the mixture was measured.   (b)  experiment 2   experiment 1 was repeated using 1  g of iron powder instead of zinc. the initial and  maximum temperatures were measured.  (c)  experiment 3   experiment 1 was repeated using 1  g of magnesium powder instead of zinc. the initial  and maximum temperatures were measured.   use the thermometer diagrams to record the temperatures in the table. complete the  table. experimentthermometer  diagraminitial temperature  / \u00b0cthermometer  diagrammaximum temperature  / \u00b0ctemperature rise  / \u00b0c 130 25 2030 25 20 230 25 2030 25 20 330 25 2080 75 70 [3]  (d)  experiment 4   using a measuring cylinder, 10  cm3 of aqueous copper sulfate was poured into a boiling  tube. the temperature of the solution was measured.   1 g of magnesium powder was added to the boiling tube and the mixture stirred with the  thermometer.   the gas was tested with a lighted splint and a loud pop was observed. the maximum  temperature of the mixture was measured.",
            "8": "8 0620/62/o/n/13 \u00a9 ucles 2013for examiner\u2019s use (e)  experiment 5   experiment 4 was repeated using 1  g of iron powder instead of magnesium. a red-brown  solid was formed.   use the thermometer diagrams to record the temperatures in the table. complete the  table. experimentthermometer  diagraminitial temperature  / \u00b0cthermometer  diagrammaximum temperature  / \u00b0ctemperature rise  / \u00b0c 4 5 [3]  (f)  draw a labelled bar chart for the results of experiments 1, 2, 3, 4 and 5 on the grid below. temperature rise  / \u00b0c [5]",
            "9": "9 0620/62/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use  use the results and observations to answer the following questions.  (g) (i)   which experiment produced the largest temperature rise?   . .  [1]  (ii)  suggest why this experiment produced the largest temperature rise.   . .  [1]  (h)  name the gas given off in experiment 4.   ... ..  [1]  (i) (i)  identify the red-brown solid formed in experiment 5.   . .  [1]  (ii)  what type of chemical reaction occurs when iron reacts with aqueous copper( ii)  sulfate in experiment 5?   . .  [1]  (j)  predict the effect on the temperature change if 1  g of magnesium ribbon was used in  experiment 3. explain your answer.  effect  .. ...  explanation  . ..   ... ..  [2]  (k)  suggest why potassium was not used as one of the metals in these experiments.   ...    ... ..  [1] [total: 19]",
            "10": "10 0620/62/o/n/13 \u00a9 ucles 2013for examiner\u2019s use5  two different liquids, a and b, were analysed.   a was an aqueous solution of ethanoic acid and b was a pure liquid.   the tests on the liquids and some of the observations are in the following table.   complete the observations in the table. tests observations tests on liquid a liquid a was divided into three equal portions  in separate test-tubes. (a)  colour and smell of liquid a.   the liquid was added to universal  indicator.    [1]  colour changed from green to  .. ph  ..  [2] (b)  a piece of magnesium ribbon was added  to the second portion of liquid a.  the gas given off was tested with a splint.  ..   ..    [3] (c)  calcium carbonate was added to the third  portion of liquid a.     [1]",
            "11": "11 0620/62/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s usetests observations tests on liquid b (d)  dilute sulfuric acid was added to liquid  b followed by aqueous potassium  manganate( vii). the mixture was  heated.changed colour from purple to colourless (e)  liquid b was poured onto a dry watch  glass. the surface of the liquid was touched with a lighted splint.liquid burned with a yellow  / blue \ufb02 ame  (f)  what conclusions can you draw about liquid b?   ...    ... ..  [2] [total: 9]",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/62/o/n/13 \u00a9 ucles 2013for examiner\u2019s use6 hair bleach   a solution of hydrogen peroxide can be used to bleach hair. hairdressers buy \u201820 volume\u2019  hydrogen peroxide. one volume of this solution breaks down to form 20 volumes of oxygen. for example 10  cm3 of 20 volume hydrogen peroxide will break down to produce 200  cm3 of  oxygen.   old solutions of hydrogen peroxide will produce less oxygen than expected.   plan an experiment to \ufb01 nd out which of two solutions of hydrogen peroxide, h and j, is  new and which is old. you are provided with common laboratory apparatus and the catalyst  manganese( iv) oxide which speeds up the break down of hydrogen peroxide.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [5] [total: 5]"
        },
        "0620_w13_qp_63.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use a pencil for any diagrams, graphs or rough working.do not use staples, paper clips, highlighters, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical october/november 2013  1 hour candidates answer on the question paper. no additional materials are required.university of cambridge international examinations international general certi \ufb01 cate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib13 11_0620_63/rp\u00a9 ucles 2013 *8630438523*",
            "2": "2 0620/63/o/n/13 \u00a9 ucles 2013for examiner\u2019s use1  a student tried to separate a mixture of salt and sand. salt, sodium chloride, is soluble in  water. sand, silicon( iv) oxide, is insoluble in water. he added the mixture to water. three  sets of apparatus are shown. a bc  (a)  complete the boxes to identify the pieces of apparatus. [2]  (b)  fill in the blanks in the following sentences.   liquids that dissolve substances are called  .   the clear liquid formed is a . . [2]  (c)  which set of apparatus should be used to obtain   the sand, ...    salt crystals? .   [2]  (d)  what happened to the water used in the experiment?   ... ..  [1] [total: 7]",
            "3": "3 0620/63/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use2  sulfur dioxide is a poisonous gas which is denser than air and soluble in water.   sulfur dioxide can be prepared by adding dilute hydrochloric acid to sodium sul \ufb01 te and  warming the mixture.   study the diagram of the apparatus used. hydrochloric acid sodium sulfitewater heat  (a)  identify and explain three  mistakes in the diagram.  1   mistake  . ...       reason    [2]  2   mistake  . ...       reason    [2]  3   mistake  . ...       reason    [2]  (b)  state one precaution that should be taken when carrying out this experiment.   ... ..  [1] [total: 7]",
            "4": "4 0620/63/o/n/13 \u00a9 ucles 2013for examiner\u2019s use3  a scientist measured the boiling point of water at different pressures.  (a)  use the thermometer diagrams in the table to complete the boiling point temperatures. pressure / atmospheresthermometer diagramboiling point / \u00b0c 1105 100 95 2125 120 115 3140 135 130 4140 135 130 5155 150 145 6160 155 150 7170 165 160 [3]",
            "5": "5 0620/63/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (b)  plot the points on the grid and draw a smooth line graph. 170 160150140130120 110 100 01234 pressure  / atmospheres5678boiling point  / \u00b0c [4]  (c)  state which point is inaccurate. why have you chosen this point?   ...    ... ..  [2]  (d)  use your graph  to \ufb01 nd the boiling point of water at a pressure of 7.5 atmospheres.   show clearly on the grid  how you obtained your answer.   ... ..  [3]  (e)  state a chemical test for water.  test     result  .. .  [2] [total: 14]",
            "6": "6 0620/63/o/n/13 \u00a9 ucles 2013for examiner\u2019s use4  a student investigated the reaction between aqueous potassium manganate( vii), which is  purple, and two different colourless acidic solutions, d and e.   three experiments were carried out.  (a)  experiment 1   a burette was \ufb01 lled with the solution of potassium manganate( vii) to the 0.0  cm3 mark.  using a measuring cylinder, 25  cm3 of solution d was poured into a conical \ufb02 ask.    potassium manganate( vii) solution was added to the \ufb02 ask until the mixture just turned  permanently pink.   use the burette diagram to record the \ufb01 nal volume in the table and complete the table. 14 15 16 final reading burette reading \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [2]  (b)  experiment 2   experiment 1 was repeated using 25  cm3 of solution e instead of solution d.   use the burette diagrams to record the readings in the table and complete the table. 15 16 27 initial reading46 47 48 final reading burette reading \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [2]",
            "7": "7 0620/63/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use (c)  experiment 3   aqueous ammonia was added to solution e in a test-tube. a green precipitate was  observed.   the mixture was left to stand for 5 minutes. the surface of the precipitate turned brown.  what conclusions can you draw from these observations?  ...    ... ..  [3]  (d) (i)  what colour change was observed as potassium manganate( vii) solution was  added to the \ufb02 ask in experiment 1?   . .  [1]  (ii)  why was an indicator not added to the \ufb02 ask?   . .  [1]  (e) (i)  in which experiment was the greatest volume of potassium manganate( vii) solution  used?   . .  [1]  (ii)  compare the volumes of potassium manganate( vii) used in experiments 1 and 2.   . .  [1]  (iii)  suggest an explanation for the difference in volumes.   . ...   . ...   . .  [2]  (f)  if experiment 2 was repeated using 12.5  cm3 of solution e, what volume of potassium  manganate( vii) solution would be used? explain your answer.   ...    ... ..  [2]  (g)  give one advantage and one disadvantage of using a measuring cylinder for solutions d  and e.  advantage  ... ..  disadvantage  ..  [2] [total: 17]",
            "8": "8 0620/63/o/n/13 \u00a9 ucles 2013for examiner\u2019s use5  two liquids, f and g, were analysed. g was an aqueous solution of potassium chloride.   the tests on the liquids and some of the observations are in the following table.   complete the observations in the table. tests observations tests on liquid f (a) (i)   appearance of liquid f.   the ph of the liquid was tested.  (ii)   an equal volume of dilute sulfuric acid  was added to liquid f.    excess aqueous sodium hydroxide  was then added to the mixture.yellow solution ph = 7 solution turned orange solution turned from orange to yellow (b)  dilute sulfuric acid was added to liquid f  followed by hydrogen peroxide.   the mixture was shaken and the gas  given off tested with a splint.rapid effervescence glowing splint relit tests on liquid g (c)  dilute nitric acid was added to liquid g  followed by aqueous barium nitrate.    [1] (d)  dilute nitric acid was added to liquid g  followed by aqueous silver nitrate.     [2]  (e)  what does test (a)(i)  tell you about liquid f?   ...    ... ..  [2]  (f)  what type of reaction happened in test (a)(ii) ? explain your answer.  type of reaction   .  explanation  . ..   ... ..  [2]  (g)  identify the gas given off in test (b).   ... ..  [1] [total: 8]",
            "9": "9 0620/63/o/n/13 \u00a9 ucles 2013 [turn overfor examiner\u2019s use6 indigestion tablets   indigestion pain is caused by too much acid in your stomach. the acid is hydrochloric acid.   indigestion tablets contain a base which neutralises the acid.   you are provided with two different brands of indigestion tablets, painremuve and indcure.   plan an investigation to compare which of these brands of tablet is the most effective. you are  provided with dilute hydrochloric acid and common laboratory apparatus.   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... ...   ... .  [7] [total: 7]",
            "10": "10 0620/63/o/n/13blank page \u00a9 ucles 2013",
            "11": "11 0620/63/o/n/13blank page \u00a9 ucles 2013",
            "12": "12 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. university of cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand  name of university of  cambridge local examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/63/o/n/13blank page \u00a9 ucles 2013"
        }
    },
    "2014": {
        "0620_s14_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 15 printed pages and 1 blank page.  ib14 06_0620_11/2rp  \u00a9 ucles 2014 [turn over       *8079009177* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  may/june 2014       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2014 0620/11/m/j/14  1 the diagram shows the result of dropping a purple crystal into water.    water purple crystalafter five hourspurple solution     which processes take place in this experiment?     chemical  reaction diffusing dissolving  a \u0013 \u0013 \u0013  b \u0013 \u0017 \u0013  c \u0017 \u0017 \u0013  d \u0017 \u0013 \u0013     2 the four pieces of apparatus shown below are used in chemical experiments.    burette measuring cylinderpipette thermometer     which statement about the apparatus is correct?  a the burette measures the volume of liquid added in a titration.  b the measuring cylinder measures the mass of a substance used in an experiment.  c the pipette measures the volume of gas given off in a reaction.  d the thermometer measures the density of a solution.     ",
            "3": "3  \u00a9 ucles 2014 0620/11/m/j/14 [turn over  3 alcohol and water are completely miscible. this means when mixed together they form only one  liquid layer.    which method is used to separate alcohol from water?  a crystallisation  b filtration  c fractional distillation  d precipitation     4 the diagram shows the structure of an atom of element x.    5p 6n eeeeekey e  = electronn  = neutronp  = proton    = nucleus     what is x?  a boron  b carbon  c sodium  d sulfur     ",
            "4": "4  \u00a9 ucles 2014 0620/11/m/j/14  5 the diagrams show four particles.    1 key = an electron = a neutron = a proton2p 2n = nucleuse e e2 3p3ne e e 3 3p3ne e e e4 3p4ne e ee n p     which two diagrams show atoms  that are isotopes of each other?  a 1 and 2 b 1 and 3 c 2 and 3 d 2 and 4     6 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     when the percentage of graphite is increased, the pencil slides across the paper more easily.    which statement explains this observation?  a graphite has a high melting point.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.     ",
            "5": "5  \u00a9 ucles 2014 0620/11/m/j/14 [turn over  7 element x is in group i of the periodic table. x reacts with element y to form an ionic compound.    which equation shows the process that takes place when x forms ions?  a x  +  e\u2013  \u2192  x+  b x  \u2013  e\u2013  \u2192  x\u2013  c x  +  e\u2013  \u2192  x\u2013  d x  \u2013  e\u2013  \u2192  x+      8 solid f is an element.    solid g is a compound.  neither solid conducts electricity but g conducts electricity when dissolved in water.    these properties suggest that f is \u2026\u20261\u2026\u2026 and that g is \u2026\u20262\u2026\u2026 with \u2026\u20263\u2026\u2026 bonds.    which words correctly complete gaps 1, 2 and 3?     1 2 3  a diamond agc l covalent  b diamond nac l ionic  c graphite agc l ionic  d graphite nac l covalent      9 a compound contains one atom of calcium, two atoms of hydrogen and two atoms of oxygen.    what is the correct chemical formula of the compound?  a cao 2h2 b hocaoh c h 2cao 2 d ca(oh) 2     10 in athletics, banned drugs such as nandrolone have been taken illegally to improve performance. nandrolone has the molecular formula c 18h26o2.    what is the relative molecular mass, mr, of nandrolone?    (relative atomic mass:  h = 1;  c = 12;  o = 16)  a 46 b 150 c 274 d 306     11 which substance will not conduct electricity?  a aluminium  b copper  c plastic  d steel   ",
            "6": "6  \u00a9 ucles 2014 0620/11/m/j/14  12 which products are formed at the anode and cathode when electricity is passed through molten  lead( ii) bromide?     anode (+) cathode (\u2013)  a bromide ions lead ions  b bromine molecules lead atoms  c lead atoms bromine molecules  d lead ions bromide ions      13 some reactions are endothermic.    how does the temperature and energy change in an endothermic reaction?     temperature change energy change  a decreases energy taken in  b decreases energy given out  c increases energy taken in  d increases energy given out     14 two chemical processes are described below.    \u25cf in the combustion of methane, energy is ..1.. .  \u25cf in the electrolysis of molten lead( ii) bromide, energy is ..2.. .    which words correctly complete gaps 1 and 2?     1 2  a given out given out  b given out taken in  c taken in given out  d taken in taken in     15 which equation shows an oxidation reaction?  a c  +  o 2  \u2192  co 2  b caco 3  \u2192  cao  +  co 2  c cao  +  2hc l  \u2192  cac l 2  +  h 2o  d n2o4  \u2192  2no 2     ",
            "7": "7  \u00a9 ucles 2014 0620/11/m/j/14 [turn over  16 in separate experiments, a catalyst is added to a reaction mixture and the temperature of the  mixture is decreased.    what are the effects of these cha nges on the rate of the reaction?     catalyst  added temperature  decreased  a faster faster  b faster slower  c slower faster  d slower slower      17 an experiment is carried out to investigate the rate of reaction when calcium carbonate is reacted  with hydrochloric acid.    the volume of carbon dioxide gas given off is measured at different intervals of time.    the diagram shows pieces of apparatus used to collect gases.    1 downward delivery2 gas measuring syringe3 over water in graduated tube     which apparatus is suitable to collect and measure the volume of the carbon dioxide?  a 1, 2 and 3 b 2 and 3 only c 1 only d 3 only     ",
            "8": "8  \u00a9 ucles 2014 0620/11/m/j/14  18 the equation shows a reaction that is reversed by changing the conditions.       forward reaction  cuso 4.5h 2o    cuso 4  +  5h 2o    how can the forward reaction be reversed?     by adding water by heating  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      19 which statements about alkalis are correct?    1 when reacted with an acid, the ph of the alkali increases.  2 when tested with litmus, the litmus turns blue.  3 when warmed with an ammonium salt, ammonia gas is given off.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      20 only two elements are liquid at 20  \u00b0c. one of these elements is shiny and conducts electricity.    this suggests that this element is a ..1 .. and therefore its oxide is ..2.. .    which words correctly complete gaps 1 and 2?     1 2  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic     21 which acid reacts with ammonia to produce the salt ammonium sulfate?  a hydrochloric  b nitric  c phosphoric  d sulfuric     ",
            "9": "9  \u00a9 ucles 2014 0620/11/m/j/14 [turn over  22 aqueous sodium hydroxide is added to solid x and the mixture is heated.    a green precipitate is formed and an alkaline gas is given off.    which ions are present in x?  a nh 4+ and fe2+  b nh 4+ and fe3+  c oh\u2013 and fe2+  d oh\u2013 and fe3+      23 which statement about the periodic table is correct?  a elements in the same period have the same number of outer electrons.  b the elements on the left are usually gases.  c the most metallic elements are on the left.  d the relative atomic mass of the elements increases from right to left.      24 why is argon gas used to fill electric lamps?  a it conducts electricity.  b it glows when heated.  c it is less dense than air.  d it is not reactive.      25 an element melts at 1455  \u00b0c, has a density of 8.90  g / cm3 and forms a green chloride.    where in the periodic table is this element found?    cb da      ",
            "10": "10  \u00a9 ucles 2014 0620/11/m/j/14  26 the diagrams show two items that may be found in the home. each item contains zinc.    zinc plated bucket brass door-knocker    in which is zinc used as an alloy?     bucket door-knocker  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     27 in an experiment, three test-tubes labelled x, y and z were half-filled with dilute hydrochloric  acid. a different metal was added to each test-tube. after a few minutes the following observations were made.    in tube x, bubbles slowly rose to the surface.  in tube y, there was a rapid release of bubbles.  in tube z, no bubbles were produced.    which three metals match the observations?     tube x tube y tube z  a copper zinc iron  b magnesium iron copper  c zinc magnesium copper  d zinc magnesium iron     ",
            "11": "11  \u00a9 ucles 2014 0620/11/m/j/14 [turn over  28 the table shows properties of four metals.    which metal is the most suitable for aircraft construction?     density strength resistance to  corrosion  a high high low  b high low low  c low high high  d low low high      29 the diagram shows a blast furnace.    in which part is iron ore changed to iron?    a b c d     30 the diagram shows some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3     ",
            "12": "12  \u00a9 ucles 2014 0620/11/m/j/14  31 four steel paper clips are treated as described before being placed in a beaker of water.    which paper clip rusts most quickly?  a coated with grease  b dipped in paint and allowed to dry  c electroplated with zinc  d washed with soap and rinsed     32 which compound contains two of the three essential elements needed for a complete fertiliser?  a ammonium chloride  b ammonium nitrate  c ammonium phosphate  d ammonium sulfate    33 when compound x is heated, it changes colour from green to black. compound y is formed and  a gas is given off which turns limewater milky.    what are x and y?     x y  a calcium carbonate calcium oxide  b copper carbonate carbon  c copper carbonate copper oxide  d copper sulfate copper oxide    34 acid rain is formed when sulfur dioxide and oxides of nitrogen dissolve in rain water.    which problem is not caused by acid rain?  a breathing difficulties  b dying trees  c erosion of statues  d lowered ph of lakes    ",
            "13": "13  \u00a9 ucles 2014 0620/11/m/j/14 [turn over  35 which pollutant gas is produced by the decomposition of vegetation?   a carbon monoxide  b methane  c nitrogen oxide  d sulfur dioxide      36 which type of compound is shown?    h c hh hh c hh c oh     a alcohol  b alkane  c alkene  d carboxylic acid      37 the table shows the composition of four different types of petroleum (crude oil).    fraction arabian heavy  / % arabian light  / % iranian heavy  / % north sea  / %  gasoline 18 21 21 23  kerosene 11.5 13 13 15  diesel oil 18 20 20 24  fuel oil 52.5 46 46 38    which type of petroleum is best for the motor vehicle industry?  a arabian heavy  b arabian light  c iranian heavy  d north sea     ",
            "14": "14  \u00a9 ucles 2014 0620/11/m/j/14  38 alkenes are manufactured by cracking hydrocarbons obtained from petroleum.    alkane x obtained from petroleumalkene ycracking     which row describes the process of cracking?     size of x  molecules size of y  molecules catalyst  required temperature  required  a large small no low  b large small yes high  c small large no low  d small large yes high     39 x, y and z are three hydrocarbons.    x ch 2=ch 2 y ch 3\u2013ch=ch 2 z ch 3\u2013ch 2\u2013ch=ch 2    what do compounds x, y and z have in common?    1 they are all alkenes.  2 they are all part of the same homologous series.  3 they all have the same boiling point.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     40 which statements about ethanol are correct?    1 it can be made by fermentation.  2 it is an unsaturated compound.  3 it burns in air and can be used as a fuel.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "15": "15  \u00a9 ucles 2014 0620/11/m/j/14  blank page",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2014 0620/11/m/j/14   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s14_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 16 printed pages.  ib14 06_0620_12/2rp  \u00a9 ucles 2014 [turn over       *3542456426* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  may/june 2014       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2014 0620/12/m/j/14  1 two gas jars each contain a different gas. the gas jars are connected and the cover slips are  removed.    the diagram shows what happens to the particles of the gases.    cover slips     which process has occurred?  a chemical reaction  b condensation   c diffusion  d evaporation      2 a liquid is heated until it boils.    thermomete r test-tube 25 cm3 liquid ethanolspirit burner     which result shows that the liquid in the test-tube is pure water?  a condensation forms at the top of the test-tube.  b steam is produced.  c the thermometer reads 100  \u00b0c.  d there is nothing left behind in the test-tube.     ",
            "3": "3  \u00a9 ucles 2014 0620/12/m/j/14 [turn over  3 which two methods can be used to separate a salt from its solution in water?    1 crystallisation  2 decanting  3 distillation  4 filtration    a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4      4 which statements about a phosphorus atom, p31 15, are correct?    1 the nucleon number is 16.  2 the number of outer electrons is 5.  3 the proton number is 15.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     5 the diagrams show four particles.    1 key = an electron = a neutron = a proton2p 2n = nucleuse e e2 3p3ne e e 3 3p3ne e e e4 3p4ne e ee n p     which two diagrams show atoms  that are isotopes of each other?  a 1 and 2 b 1 and 3 c 2 and 3 d 2 and 4   ",
            "4": "4  \u00a9 ucles 2014 0620/12/m/j/14  6 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     when the percentage of graphite is increased, the pencil slides across the paper more easily.    which statement explains this observation?  a graphite has a high melting point.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.      7 the electronic structures of two atoms, x and y, are shown.    x y     x and y combine together to form a compound.    what is the type of bonding in the compound and what is the formula of the compound?     type of bonding formula  a covalent x 2y  b covalent xy 2  c ionic xy 2  d ionic x 2y    ",
            "5": "5  \u00a9 ucles 2014 0620/12/m/j/14 [turn over  8 the structure of an organic compound, x, is shown.    c c  c c c c c h h h hh h h  h  h  h h h      what is the molecular formula of x?  a c 6h9 b c 6h12 c c 7h12 d c 7h14      9 what is the relative molecular mass, m r, of nitrogen dioxide?  a 15 b 23 c 30 d 46     10 electrical cables are made from either \u2026\u20261\u2026\u2026, because it is a very good conductor of  electricity, or from\u2026\u20262\u2026\u2026, because it has a low density.   overhead cables have a \u2026\u20263\u2026\u2026 core in order to give the cable strength.    which words correctly complete gaps 1, 2 and 3?     1 2 3  a aluminium copper magnesium  b copper aluminium magnesium  c copper aluminium steel  d magnesium copper steel    11 what will be produced at the anode and at t he cathode, if molten potassium chloride is  electrolysed?     anode (+) cathode (-)  a chlorine hydrogen  b chlorine potassium  c hydrogen chlorine  d potassium chlorine    ",
            "6": "6  \u00a9 ucles 2014 0620/12/m/j/14  12 solutions of two chemicals are mixed.    a reaction occurs and the temperature change is measured.    which statement is correct?  a if the reaction is endothermic, the temperature decreases and energy is taken in.  b if the reaction is endothermic, the temperature increases and energy is given out.  c if the reaction is exothermic, the temperature decreases and energy is given out.  d if the reaction is exothermic, the temperature increases and energy is taken in.      13 power stations produce electrical energy from different fuels.    which fuel causes least pollution to the atmosphere?  a coal  b fuel oil  c natural gas  d radioactive isotopes     14 a student was investigating the reaction between marble chips and dilute hydrochloric acid.    bung marble chips25 cm3 dilute hydrochloric acidgas syringe     which changes would reduce the rate of reaction?     temperature  of acid concentration  of acid surface area  of marble chips  a decrease decrease decrease  b decrease decrease increase  c increase decrease decrease  d increase increase increase    ",
            "7": "7  \u00a9 ucles 2014 0620/12/m/j/14 [turn over  15 which equation shows an oxidation reaction?  a c  +  o 2  \u2192  co 2  b caco 3  \u2192  cao  +  co 2  c cao  +  2hc l  \u2192  cac l 2  +  h 2o  d n2o4  \u2192  2no 2     16 in separate experiments, a catalyst is added to a reaction mixture and the temperature of the  mixture is decreased.    what are the effects of these cha nges on the rate of the reaction?     catalyst  added temperature  decreased  a faster faster  b faster slower  c slower faster  d slower slower    17 different plants grow best under different ph conditions.    which plant grows best in alkaline soil?     plant grows best in soil at  ph  a cabbage 6-8  b potato 4-7  c strawberry 5-7  d wheat 6-7    ",
            "8": "8  \u00a9 ucles 2014 0620/12/m/j/14  18 the equation shows a reaction that is reversed by changing the conditions.       forward reaction  cuso 4.5h 2o    cuso 4  +  5h 2o    how can the forward reaction be reversed?     by adding water by heating  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      19 element x forms an oxide, xo, that neutralises sulfuric acid.    which row describes x and xo?     element x nature of oxide, xo  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic     20 copper carbonate reacts with dilute sulfuric acid to make copper sulfate.    cuco 3(s)  +  h 2so 4(aq)  \u2192  cuso 4(aq)  +  co 2(g)  +  h 2o(l)    which row gives the correct order of steps for making copper sulfate crystals?     step 1 step 2 step 3 step 4  a   add excess acid to  the copper carbonate filter   evaporate filtrate to  point of crystallisation leave to cool    b   add excess acid to  the copper carbonate filter   evaporate to  dryness leave to cool    c   add excess copper  carbonate to the acid evaporate to point  of crystallisation leave to cool   filter    d   add excess copper  carbonate to the acid filter   evaporate filtrate to  point of crystallisation leave to cool       ",
            "9": "9  \u00a9 ucles 2014 0620/12/m/j/14 [turn over  21 element x is a non-metal.    in which position of the periodic table could element x be found?  a at the bottom of group i  b at the top of group 0  c at the top of group i  d in the transition elements     22 aqueous sodium hydroxide is added to solid x and the mixture is heated.    a green precipitate is formed and an alkaline gas is given off.    which ions are present in x?  a nh 4+ and fe2+  b nh 4+ and fe3+  c oh\u2013 and fe2+  d oh\u2013 and fe3+    23 a student carried out an experiment to find the order of reactivity of five metals.    they were tested with cold water, hot water and steam and the results recorded in a table.    metal cold water hot water steam  v no reaction reacts slowly vigorous reaction  w no reaction no reaction slow reaction  x reacts slowly vigorous reaction not attempted  y no reaction no reaction no reaction  z vigorous reaction explosive reaction not attempted    what is the order of reactivity of these metals?     most reactive  least reactive  a v w y x z  b w x z v y  c z x v w y  d z x y w v     ",
            "10": "10  \u00a9 ucles 2014 0620/12/m/j/14  24 why is argon gas used to fill electric lamps?  a it conducts electricity.  b it glows when heated.  c it is less dense than air.  d it is not reactive.      25 an element melts at 1455  \u00b0c, has a density of 8.90  g / cm3 and forms a green chloride.    where in the periodic table is this element found?    cb da       26 the diagrams show two items that may be found in the home. each item contains zinc.    zinc plated bucket brass door-knocker    in which is zinc used as an alloy?     bucket door-knocker  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "11": "11  \u00a9 ucles 2014 0620/12/m/j/14 [turn over  27 which object is likely to be made from stainless steel?    bicycle chaina car bodyb can of beansc teaspoond      28 four reactions that take place in the blast furnace to produce iron are shown.    which reaction is used to keep the furnace hot?  a c  +  o 2  \u2192  co 2  b co 2  +  c  \u2192  2co  c fe 2o3  +  3c  \u2192  2fe  +  3co  d fe 2o3  +  3co  \u2192  2fe  +  3co 2     ",
            "12": "12  \u00a9 ucles 2014 0620/12/m/j/14  29 the diagram shows a blast furnace.    in which part is iron ore changed to iron?    a b c d     30 the diagram shows some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3      31 a piece of uncoated iron and three pieces of iron with various coatings were left exposed to the  air.    which piece of iron would rust?  a the painted piece  b the tin-coated piece  c the uncoated piece  d the zinc-coated piece     ",
            "13": "13  \u00a9 ucles 2014 0620/12/m/j/14 [turn over  32 which compound would not be an effective fertiliser?  a ammonium nitrate, nh 4no 3  b calcium oxide, cao  c calcium phosphate, ca 3(po 4)2  d potassium nitrate, kno 3      33 sulfur dioxide, so 2, nitrogen dioxide, no 2, and carbon monoxide, co, are air pollutants.   which row correctly shows their major source?   motor car engines power stations a co no 2, so 2  b no 2, co so 2  c so 2, no 2 co  d so 2 no 2, co     34 which process does not produce carbon dioxide?  a combustion of methane  b fermentation of sugar  c polymerisation of ethene  d respiration    35 which pollutant gas is produced by the decomposition of vegetation?  a carbon monoxide  b methane  c nitrogen oxide  d sulfur dioxide    ",
            "14": "14  \u00a9 ucles 2014 0620/12/m/j/14  36 which diagram shows the structure of pentanoic acid?    h ch hhhhhhhhh c c c c o ha hhho hhhhh c c c c chh ob h chhhhhh hhh c c c cc h chhhhhhhho c c c c h odh h      37 the table shows the composition of four different types of petroleum (crude oil).    fraction arabian heavy  /  % arabian light  / % iranian heavy  / % north sea  / %  gasoline 18 21 21 23  kerosene 11.5 13 13 15  diesel oil 18 20 20 24  fuel oil 52.5 46 46 38    which type of petroleum is best for the motor vehicle industry?  a arabian heavy  b arabian light  c iranian heavy  d north sea     ",
            "15": "15  \u00a9 ucles 2014 0620/12/m/j/14  38 the diagram shows the cracking of substance x.    y watercotton wool soaked in xcatalyst heat     which type of organic compound is found in y, which is not present in x?  a acid  b alcohol  c alkane  d alkene     39 in which reaction could one of the products bel ong to the same homologous series as the organic  reactant?  a addition of steam to ethene  b combustion of an alkane  c cracking of an alkane  d polymerisation of ethene      40 ethanol is produced from either ethene or sugar.    which type of chemical reaction is used in each case?     ethene \u2192 ethanol sugar \u2192 ethanol  a addition fermentation  b addition fractional distillation  c distillation fermentation  d distillation fractional distillation     ",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2014 0620/12/m/j/14   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s14_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 15 printed pages and 1 blank page.  ib14 06_0620_13/fp  \u00a9 ucles 2014 [turn over       *8978722695* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  may/june 2014       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2014 0620/13/m/j/14  1 the diagram shows the result of dropping a purple crystal into water.    water purple crystalafter five hourspurple solution     which processes take place in this experiment?     chemical  reaction diffusing dissolving  a \u0013 \u0013 \u0013  b \u0013 \u0017 \u0013  c \u0017 \u0017 \u0013  d \u0017 \u0013 \u0013     2 alcohol and water are completely miscible. this means when mixed together they form only one liquid layer.    which method is used to separate alcohol from water?  a crystallisation  b filtration  c fractional distillation  d precipitation     ",
            "3": "3  \u00a9 ucles 2014 0620/13/m/j/14 [turn over  3 the four pieces of apparatus shown below are used in chemical experiments.    burette measuring cylinderpipette thermometer     which statement about the apparatus is correct?  a the burette measures the volume of liquid added in a titration.  b the measuring cylinder measures the mass of a substance used in an experiment.  c the pipette measures the volume of gas given off in a reaction.  d the thermometer measures the density of a solution.      4 the diagram shows the structure of an atom of element x.    5p 6n eeeeekey e  = electronn  = neutronp  = proton    = nucleus     what is x?  a boron  b carbon  c sodium  d sulfur     ",
            "4": "4  \u00a9 ucles 2014 0620/13/m/j/14  5 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     when the percentage of graphite is increased, the pencil slides across the paper more easily.    which statement explains this observation?  a graphite has a high melting point.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.      6 the diagrams show four particles.    1 key = an electron = a neutron = a proton2p 2n = nucleuse e e2 3p3ne e e 3 3p3ne e e e4 3p4ne e ee n p     which two diagrams show atoms  that are isotopes of each other?  a 1 and 2 b 1 and 3 c 2 and 3 d 2 and 4     ",
            "5": "5  \u00a9 ucles 2014 0620/13/m/j/14 [turn over  7 solid f is an element.    solid g is a compound.   neither solid conducts electricity but g conducts electricity when dissolved in water.   these properties suggest that f is \u2026\u20261\u2026\u2026 and that g is \u2026\u20262\u2026\u2026 with \u2026\u20263\u2026\u2026 bonds.    which words correctly complete gaps 1, 2 and 3?     1 2 3  a diamond agc l covalent  b diamond nac l ionic  c graphite agc l ionic  d graphite nac l covalent    8 in athletics, banned drugs such as nandrolone have been taken illegally to improve performance.  nandrolone has the molecular formula c 18h26o2.    what is the relative molecular mass, mr, of nandrolone?    (relative atomic mass:  h = 1;  c = 12;  o = 16)  a 46 b 150 c 274 d 306     9 a compound contains one atom of calcium, two atoms of hydrogen and two atoms of oxygen.    what is the correct chemical formula of the compound?  a cao 2h2 b hocaoh c h 2cao 2 d ca(oh) 2      10 element x is in group i of the periodic table. x reacts with element y to form an ionic compound.    which equation shows the process that takes place when x forms ions?  a x  +  e\u2013  \u2192  x+  b x  \u2013  e\u2013  \u2192  x\u2013  c x  +  e\u2013  \u2192  x\u2013  d x  \u2013  e\u2013  \u2192  x+     11 which substance will not conduct electricity?  a aluminium  b copper  c plastic  d steel   ",
            "6": "6  \u00a9 ucles 2014 0620/13/m/j/14  12 two chemical processes are described below.    \u25cf in the combustion of methane, energy is ..1.. .  \u25cf in the electrolysis of molten lead( ii) bromide, energy is ..2.. .    which words correctly complete gaps 1 and 2?     1 2  a given out given out  b given out taken in  c taken in given out  d taken in taken in     13 which equation shows an oxidation reaction?  a c  +  o 2  \u2192  co 2  b caco 3  \u2192  cao  +  co 2  c cao  +  2hc l  \u2192  cac l 2  +  h 2o  d n2o4  \u2192  2no 2      14 some reactions are endothermic.    how does the temperature and energy change in an endothermic reaction?     temperature change energy change  a decreases energy taken in  b decreases energy given out  c increases energy taken in  d increases energy given out     15 which products are formed at the anode and cathode when electricity is passed through molten  lead( ii) bromide?     anode (+) cathode (\u2013)  a bromide ions lead ions  b bromine molecules lead atoms  c lead atoms bromine molecules  d lead ions bromide ions     ",
            "7": "7  \u00a9 ucles 2014 0620/13/m/j/14 [turn over  16 an experiment is carried out to investigate the rate of reaction when calcium carbonate is reacted  with hydrochloric acid.    the volume of carbon dioxide gas given off is measured at different intervals of time.    the diagram shows pieces of apparatus used to collect gases.    1 downward delivery2 gas measuring syringe3 over water in graduated tube     which apparatus is suitable to collect and measure the volume of the carbon dioxide?  a 1, 2 and 3 b 2 and 3 only c 1 only d 3 only      17 in separate experiments, a catalyst is added to a reaction mixture and the temperature of the  mixture is decreased.    what are the effects of these cha nges on the rate of the reaction?     catalyst  added temperature  decreased  a faster faster  b faster slower  c slower faster  d slower slower     18 which statements about alkalis are correct?    1 when reacted with an acid, the ph of the alkali increases.  2 when tested with litmus, the litmus turns blue.  3 when warmed with an ammonium salt, ammonia gas is given off.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "8": "8  \u00a9 ucles 2014 0620/13/m/j/14  19 which acid reacts with ammonia to produce the salt ammonium sulfate?  a hydrochloric  b nitric  c phosphoric  d sulfuric      20 the equation shows a reaction that is reversed by changing the conditions.       forward reaction  cuso 4.5h 2o    cuso 4  +  5h 2o    how can the forward reaction be reversed?     by adding water by heating  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     21 only two elements are liquid at 20  \u00b0c. one of these elements is shiny and conducts electricity.    this suggests that this element is a ..1 .. and therefore its oxide is ..2.. .    which words correctly complete gaps 1 and 2?     1 2  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic     ",
            "9": "9  \u00a9 ucles 2014 0620/13/m/j/14 [turn over  22 an element melts at 1455  \u00b0c, has a density of 8.90  g / cm3 and forms a green chloride.    where in the periodic table is this element found?    cb da      23 why is argon gas used to fill electric lamps?  a it conducts electricity.  b it glows when heated.  c it is less dense than air.  d it is not reactive.     24 which statement about the periodic table is correct?  a elements in the same period have the same number of outer electrons.  b the elements on the left are usually gases.  c the most metallic elements are on the left.  d the relative atomic mass of the elements increases from right to left.      25 aqueous sodium hydroxide is added to solid x and the mixture is heated.    a green precipitate is formed and an alkaline gas is given off.    which ions are present in x?  a nh 4+ and fe2+  b nh 4+ and fe3+  c oh\u2013 and fe2+  d oh\u2013 and fe3+    ",
            "10": "10  \u00a9 ucles 2014 0620/13/m/j/14  26 in an experiment, three test-tubes labelled x, y and z were half-filled with dilute hydrochloric  acid. a different metal was added to each test-tube. after a few minutes the following  observations were made.    in tube x, bubbles slowly rose to the surface.  in tube y, there was a rapid release of bubbles.  in tube z, no bubbles were produced.    which three metals match the observations?     tube x tube y tube z  a copper zinc iron  b magnesium iron copper  c zinc magnesium copper  d zinc magnesium iron     27 the diagrams show two items that may be found in the home. each item contains zinc.    zinc plated bucket brass door-knocker    in which is zinc used as an alloy?     bucket door-knocker  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "11": "11  \u00a9 ucles 2014 0620/13/m/j/14 [turn over  28 the diagram shows some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3     29 the table shows properties of four metals.    which metal is the most suitable for aircraft construction?     density strength resistance to  corrosion  a high high low  b high low low  c low high high  d low low high    30 the diagram shows a blast furnace.    in which part is iron ore changed to iron?    a b c d     ",
            "12": "12  \u00a9 ucles 2014 0620/13/m/j/14  31 acid rain is formed when sulfur dioxide and oxides of nitrogen dissolve in rain water.    which problem is not caused by acid rain?  a breathing difficulties  b dying trees  c erosion of statues  d lowered ph of lakes     32 which compound contains two of the three essential elements needed for a complete fertiliser?  a ammonium chloride  b ammonium nitrate  c ammonium phosphate  d ammonium sulfate    33 four steel paper clips are treated as described before being placed in a beaker of water.    which paper clip rusts most quickly?  a coated with grease  b dipped in paint and allowed to dry  c electroplated with zinc  d washed with soap and rinsed      34 when compound x is heated, it changes colour from green to black. compound y is formed and  a gas is given off which turns limewater milky.    what are x and y?     x y  a calcium carbonate calcium oxide  b copper carbonate carbon  c copper carbonate copper oxide  d copper sulfate copper oxide    ",
            "13": "13  \u00a9 ucles 2014 0620/13/m/j/14 [turn over  35 which type of compound is shown?    h c hh hh c hh c oh     a alcohol  b alkane  c alkene  d carboxylic acid     36 the table shows the composition of four different types of petroleum (crude oil).    fraction arabian heavy  /  % arabian light  / % iranian heavy  / % north sea  / %  gasoline 18 21 21 23  kerosene 11.5 13 13 15  diesel oil 18 20 20 24  fuel oil 52.5 46 46 38    which type of petroleum is best for the motor vehicle industry?  a arabian heavy  b arabian light  c iranian heavy  d north sea      37 which pollutant gas is produced by the decomposition of vegetation?  a carbon monoxide  b methane  c nitrogen oxide  d sulfur dioxide    ",
            "14": "14  \u00a9 ucles 2014 0620/13/m/j/14  38 x, y and z are three hydrocarbons.    x ch 2=ch 2 y ch 3\u2013ch=ch 2 z ch 3\u2013ch 2\u2013ch=ch 2    what do compounds x, y and z have in common?    1 they are all alkenes.  2 they are all part of the same homologous series. 3 they all have the same boiling point.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      39 alkenes are manufactured by cracking hydrocarbons obtained from petroleum.    alkane x obtained from petroleumalkene ycracking     which row describes the process of cracking?     size of x  molecules size of y  molecules catalyst  required temperature  required  a large small no low  b large small yes high  c small large no low  d small large yes high     40 which statements about ethanol are correct?    1 it can be made by fermentation.  2 it is an unsaturated compound.  3 it burns in air and can be used as a fuel.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "15": "15  \u00a9 ucles 2014 0620/13/m/j/14  blank page",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publis her (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2014 0620/13/m/j/14   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s14_qp_21.pdf": {
            "1": "this document consists o f 17 printed pages and 3 blank pages . [turn overib14 06_0620_21/2rp \u00a9 ucles 2014 *1339612500* read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 20. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 may/june 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/21/m/j/14 \u00a9 ucles 20141 (a)   choose from the list of substances below to answer the following questions. calcium oxide carbon dioxide carbon monoxide copper hydrogen magnesium methane oxygen water   each substance may be used once, more than once or not at all.   which substance:  (i)  releases hydrogen when it reacts with steam,   . ..  [1]  (ii)  is produced at the cathode when concentrated aqueous sodium chloride is electrolysed,   . ..  [1]  (iii)  is a product of the incomplete combustion of carbon,   . ..  [1]  (iv)  is used in electrical wiring,   . ..  [1]  (v)  is manufactured by heating limestone?   . ..  [1]  (b)  complete the following sentences about the periodic table of elements using words from the  list below.  argon colour density sodium  one similarity  trend  seven   chlorine, bromine and iodine are elements in group . of the periodic table.   these elements show a . in . down the group.   they all react rapidly with . to form ionic compounds. [4] [total: 9]",
            "3": "3 0620/21/m/j/14 \u00a9 ucles 2014 [turn over2  in 1904, j. j. thomson suggested a model of the atom. he called this the \u2018plum pudding\u2019 model.  this model of an atom, containing 14 electrons, is shown below. sphere of positive charge which is spread out electrons  (a)  describe how thomson\u2019s model of the atom differs from our present ideas of the structure of  an atom.   ... .   ... .   ... .   ... ...  [3]  (b)  lithium has two naturally-occurring isotopes. these can be written as: 6 3li73li and  (i) describe the difference between these isotopes.   . ..  [1]  (ii)  isotopes can be radioactive or non-radioactive.   state one industrial use of radioactive isotopes.   . ..  [1]  (c)  lithium is in group i of the periodic table.   the table shows some properties of the group i elements. metal melting point  / \u00b0c atomic radius  / nm lithium 0.157 sodium 98 0.191potassium 63rubidium 39 0.250caesium 29 0.272  deduce:   the melting point of lithium,  ... \u00b0c   the atomic radius of potassium   nm [2]",
            "4": "4 0620/21/m/j/14 \u00a9 ucles 2014 (d)   lithium reacts with water. an alkaline solution and a colourless gas are formed.  (i)  complete the word equation for this reaction. lithium   +   water   \u2192   ..   ..   +   .. [2]  (ii)  what is the most likely ph of the alkaline solution?   put a ring around the correct answer. ph 2                ph 5                ph 7                ph 13 [1]  (e)  draw the electronic structure of a potassium atom. [2] [total: 12]",
            "5": "5 0620/21/m/j/14 \u00a9 ucles 2014 [turn over3  the table shows some fractions obtained from the distillation of petroleum. fractionnumber of carbon atomsboiling point of the fraction  / \u00b0c re\ufb01 nery gas 1  \u2013 4 under 40 gasoline 5  \u2013 10 40  \u2013 160 kerosene 10  \u2013 16 160  \u2013 250 diesel 16  \u2013 20 250  \u2013 300 fuel oil 20  \u2013 30 300  \u2013 350  (a)  what is the relationship between the number of carbon atoms and the boiling points of the  fractions?   ... ...  [1]  (b)  state the names of two petroleum fractions not given in the table.  ... and .. . [2]  (c) two of the compounds present in re \ufb01 nery gas are methane and ethane.  (i)  draw the structure of ethane. show all atoms and bonds. [1]  (ii)  complete the dot and cross diagram of methane to show all the electrons. h h h c h [2]",
            "6": "6 0620/21/m/j/14 \u00a9 ucles 2014 (d)  re\ufb01 nery gas also contains propane.   propane can be cracked in the presence of a catalyst to form hydrogen.  (i)  complete the symbol equation for this reaction. c3h8   \u2192   ...   +   h2 [1]  (ii)  a catalyst is one condition needed to crack an alkane.   state one other condition needed to crack an alkane.   . ..  [1] [total: 8]",
            "7": "7 0620/21/m/j/14 \u00a9 ucles 2014 [turn over4  the diagram shows the changes of state when tin vapour is cooled slowly to room temperature. tin vapourliquid tinsolid tincondensation solidification (freezing)  (a)  explain what happens to the arrangement and motion of the atoms during these changes.   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  tin is a metal in group iv of the periodic table.   how many electrons does tin have in its outer shell?   ... ...  [1]  (c)  state one physical property of tin.   ... ...  [1]  (d)  the table below describes the reaction of some metals with dilute hydrochloric acid. ironbubbles of gas produced and temperature  of the mixture rises slowly magnesiummany bubbles of gas produced rapidly and  temperature of the mixture rises rapidly silverno bubbles of gas given off and no  temperature change tina few bubbles of gas given off slowly and  temperature of the mixture rises very slowly   put these metals in order of their reactivity. least reactive most reactive [2]",
            "8": "8 0620/21/m/j/14 \u00a9 ucles 2014 (e)  tin is extracted by heating tin( iv) oxide with carbon.  (i)  complete the symbol equation for this reaction. sno2   +   ...c   \u2192   sn   +   ...co [2]  (ii)  state one adverse effect of carbon monoxide on health.   . ..  [1] [total: 11]",
            "9": "9 0620/21/m/j/14 \u00a9 ucles 2014 [turn over5  the diagram shows a blast furnace for extracting iron. mixture of iron ore and coke  (a)  on the diagram above, write:  \u25cf  the letter a to show where the air blast enters the furnace,  \u25cf  the letter w to show where the waste gases exit the furnace. [2]  (b)  which one of the following is an ore of iron?   put a ring around the correct answer. calcite             \ufb02 uorite             hematite             halite [1]  (c)   in the furnace, the coke burns to form carbon dioxide. this reaction is exothermic.  (i)  what is meant by the term exothermic  ?   . ..  [1]  (ii)  describe a test for carbon dioxide.  test   ..  result  .. ...  [2]  (d)  in the blast furnace, carbon dioxide reacts with more coke to form carbon monoxide.   the carbon monoxide reduces iron( iii) oxide to iron. fe2o3  +  3co  \u2192  2fe  +  3co2   how does this equation show that iron( iii) oxide is being reduced?   ... ...  [1] [total: 7]",
            "10": "10 0620/21/m/j/14 \u00a9 ucles 20146  the structure of ethanol is shown below. hc c hh o hhh  (a)  on the structure above, put a ring around the alcohol functional group. [1]  (b)   ethanol can be made by fermentation.  (i)  complete the word equation for fermentation.    \u2192   ethanol   +       [2]  (ii)  what type of catalysts are used in fermentation?   put a ring around the correct answer. acids                carbonates                enzymes                metals [1]  (c)  ethanol can also be made by hydration.   complete the symbol equation for this reaction.    +   h2o   \u2192   c2h5oh [1]  (d)  the diagram below shows how the rate of fermentation changes with temperature. 0 1 02 03 0 temperature  / \u00b0c40 50 60rate   describe how the rate of fermentation changes with temperature.   ... .   ... .   ... ...  [2]",
            "11": "11 0620/21/m/j/14 \u00a9 ucles 2014 [turn over (e)  the table shows some properties of different alcohols. alcohol formulamelting point / \u00b0cboiling point / \u00b0cdensity in g  / cm3 methanol ch4o\u2013  94 65 ethanol c2h6o \u2013117 79 0.789 propanol c3h8o \u2013126 98 0.804 butanol c4h10o\u2013  89 117 0.810 pentanol c5h12o\u2013  79 138 0.815  (i)  describe how density changes with the number of carbon atoms in the alcohol.   . ..  [1]  (ii)  which one of these alcohols has the lowest melting point?   . ..  [1]  (iii)  is pentanol a solid, liquid or gas at room temperature?   explain your answer.   .    .    . ..  [1] [total: 10]",
            "12": "12 0620/21/m/j/14 \u00a9 ucles 20147  a student used chromatography to separate the dyes in the blue ink from a ball-point pen.   she used the equipment shown in the diagrams below. solvent large watchglass chromatography tank chromatography paper  (a)  complete the diagram below to show how she set up the apparatus. [3]  (b)  describe how chromatography could be used by the student to separate the dyes.   ... .   ... .   ... ...  [3]  (c)  the student used water as a solvent. suggest a different solvent that she could use.   ... ...  [1]",
            "13": "13 0620/21/m/j/14 \u00a9 ucles 2014 [turn over (d)  the diagram below shows the results of the chromatography using the blue ink, b, and several  pure dyes, w, x, y and z. bwxyz  (i)  which of the dyes, w, x, y and z, were in the blue ink?   . ..  [1]  (ii)  how many dyes in the ink had been separated by this chromatography?   . ..  [1]  (e)  the diagram shows the ball-point pen used in the experiment. alloy tippoly(ethene) cap ink  (i)  the cap of the pen is made of poly(ethene).   describe the formation of poly(ethene) from ethene. in your answer, include the words:  \u25cf monomer,  \u25cf polymer.   .    .    . ..  [2]  (ii)  the tip of the pen is made from an alloy.   what is meant by the term alloy  ?   .    . ..  [1]",
            "14": "14 0620/21/m/j/14 \u00a9 ucles 2014 (f)  the table shows some properties of four alloys. alloystrength / gpadensity in g  / cm3thermal conductivity in w  / m / k low strength steel 250 7.70 60 high strength steel 300 7.90 56low strength aluminium 70 2.72 170high strength aluminium 220 2.80 100  (i)  how does the strength of the steel and aluminium alloys vary with their thermal  conductivity?   . ..  [1]  (ii)  which one of these alloys is the best one to use to make the body of an aircraft?   give two reasons for your answer.   .    .    . ..  [3] [total: 16]",
            "15": "15 0620/21/m/j/14 \u00a9 ucles 2014 [turn over8  zinc can be extracted from zinc sul \ufb01 de ore in three steps.  (a)  in the \ufb01 rst step, zinc sul \ufb01 de is heated in air to produce zinc oxide.  (i)  complete the symbol equation for this reaction. 2zns   +   o2   \u2192   2zno   +   .so2 [2]  (ii)  the product sulfur dioxide, so2, is harmful to the environment.   explain why it is harmful to the environment and state one effect it has on buildings.   .    . ..  [2]  (b) in the second step, zinc oxide reacts with sulfuric acid to form zinc sulfate. zinc oxide  +  sulfuric acid  \u2192  zinc sulfate  +  water   zinc sulfate is soluble in water.   some insoluble impurities in the zinc oxide do not react with the sulfuric acid.   suggest how these insoluble impurities are removed from the zinc sulfate solution.   ... ...  [1]  (c)  in the third step, zinc is extracted from zinc sulfate by electrolysis using the cell shown below. +\u2013lead rod aluminium rod aqueous zinc sulfate  (i)  which word best describes the aluminium rod?   put a ring around the correct answer. anion          anode          cathode          cation          electrolyte          product [1]",
            "16": "16 0620/21/m/j/14 \u00a9 ucles 2014 (ii)  suggest which statement about this electrolysis is completely correct.   tick one box.  zinc is formed at the positive electrode and  hydrogen at the negative electrode.  zinc is formed at the positive electrode and  oxygen at the negative electrode.  zinc is formed at the negative electrode and  hydrogen at the positive electrode.  zinc is formed at the negative electrode and  oxygen at the positive electrode. [1] [total: 7]",
            "17": "17 0620/21/m/j/14 \u00a9 ucles 2014blank page",
            "18": "18 0620/21/m/j/14 \u00a9 ucles 2014blank page",
            "19": "19 0620/21/m/j/14 \u00a9 ucles 2014blank page",
            "20": "20 0620/21/m/j/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s14_qp_22.pdf": {
            "1": "this document consists of 15 printed pages and 1 bla nk page. [turn overib14 06_0620_22/3rp \u00a9 ucles 2014 *6390889396* read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 may/june 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/22/m/j/14 \u00a9 ucles 2014blank page",
            "3": "3 0620/22/m/j/14 \u00a9 ucles 2014 [turn over1  the diagram shows part of the periodic table. only some of the elements are shown. h li c n o na a l k f ec on ic uz n rb cs pb  (a)  answer the following questions using only the elements shown in the diagram.   each element may be used once, more than once or not at all.  (i)  which element has a giant covalent structure?    [1]  (ii)  which element has the highest relative atomic mass?  .  [1]  (iii)  which two elements are formed when molten aluminium oxide is electrolysed? ..  and  ..  [1]  (iv)  which element in group i reacts most rapidly with water?  ...  [1]  (v)  which element oxidises in the presence of water to form rust?  ...  [1]  (vi)  which element burns in oxygen to form water?  ...  [1]  (b)  rubidium reacts with oxygen to form rubidium oxide, rb2o.   complete the symbol equation for this reaction. rb   +   ..   \u2192   2rb2o [2]  (c)  lead compounds are atmospheric pollutants.   state one adverse effect of lead compounds on health.   ... ...  [1] [total: 9]",
            "4": "4 0620/22/m/j/14 \u00a9 ucles 20142  carbon dioxide can be prepared in the laboratory using the apparatus shown below. hydrochloric acidacarbon dioxideb marble chips(calcium carbonate)  (a)  state the names of the pieces of apparatus labelled a and b.  a  . ...  b  . ... [2]  (b)  complete the word equation for this reaction. calcium carbonate+hydrochloric acid\u2192. .+carbon dioxide+ . [2]  (c)  carbon dioxide is slightly soluble in water.   what effect will this have on the volume of carbon dioxide collected?   tick one box.  the volume is lower than expected. the volume is higher than expected. the volume is the same as expected. no carbon dioxide is collected. [1]",
            "5": "5 0620/22/m/j/14 \u00a9 ucles 2014 [turn over (d)  a burning candle is lowered into a beaker of carbon dioxide. beake r candle  (i)  the \ufb02 ame goes out.   explain why the \ufb02 ame goes out.   . ..  [1]  (ii)  after 20 seconds, the candle is removed and relit.   it is then lowered into the same beaker again.   the \ufb02 ame goes out again.   what does this tell you about the density of carbon dioxide compared to air?   . ..  [1]  (iii)  after 40 minutes, the candle is removed and relit.   it is then lowered into the same beaker again.   the candle stays alight.   explain why the candle stays alight.   .    .    . ..  [2] [total: 9]",
            "6": "6 0620/22/m/j/14 \u00a9 ucles 20143  river water contains a variety of ions and gases, and insoluble materials such as soil particles.  (a)  describe how you could remove the insoluble materials from a sample of river water.   include a labelled diagram.   ... .   ... .   ... .   ... ...  [4]  (b) the table shows the ions present in a sample of river water.  name of ion formula of ionconcentration  in mg  / dm3 calcium ca2+0.6 chloride c l \u201314.0 hydrogen carbonate hco3\u20131.5 iron(iii)f e3+0.5 magnesium mg2+1.0 potassium k+3.0 sodium na+11.0 so42\u20130.4  (i)  which ion with a charge of 2+ is present in the highest concentration?   . ..  [1]  (ii)  state the name of the ion with the formula so42\u2013.   . ..  [1]",
            "7": "7 0620/22/m/j/14 \u00a9 ucles 2014 [turn over (iii)  calculate the total mass of ions present in 1  dm3 of river water. .. mg  [1]  (iv)  use your answer to part (iii) to calculate the total mass of ions in 50  cm3 of river water. .. mg  [1]  (v)  a student evaporated the sample of river water to leave a solid containing a number of  different compounds.   use the information in the table to suggest the name of the compound present in the  greatest amount.   . ..  [1]",
            "8": "8 0620/22/m/j/14 \u00a9 ucles 2014 (c)  the table shows the solubility of oxygen in river water at different temperatures. temperature  / \u00b0c 0 10 20 30 40 50 60 solubility in mg  / dm311.0 8.8 7.2 6.0 4.9 4.2 3.6  (i)  on the axes below, plot a graph to show how the solubility of oxygen changes with  temperature. draw a curve of best \ufb01 t through the points. 12 10 864 2 0 0 1 02 03 0 temperature  / \u00b0csolubility in mg  / dm3 40 50 60 [3]  (ii)  deduce the solubility of oxygen in river water at 25  \u00b0c.   . ..  [1]  (iii)  state the approximate percentage of oxygen in the air .   . ..  [1] [total: 14]",
            "9": "9 0620/22/m/j/14 \u00a9 ucles 2014 [turn over4  the alkanes are a homologous series of hydrocarbons.  (a)  name another homologous series of hydrocarbons.   ... ...  [1]  (b)  the graph below shows how the melting points of the \ufb01 rst eight alkanes vary with the number  of carbon atoms. 12345 number of carbon atoms6789 1 00 \u201350 \u2013100\u2013150\u2013200melting point  / \u00b0c  (i)  describe how the melting points of these alkanes vary with the number of carbon atoms.   .    .    . ..  [2]  (ii)  on the graph above , continue the line to show the melting points of the hydrocarbons  having 9 and 10 carbon atoms. [2]  (c)  the \ufb01 rst member of the alkane homologous series is methane.  (i)  state one source of the methane in the atmosphere.   . ..  [1]  (ii)  state one adverse effect of methane in the atmosphere.   . ..  [1]  (d)  complete the symbol equation to show the complete combustion of methane. ch4   +   o2   \u2192      +   2h2o [2] [total: 9]",
            "10": "10 0620/22/m/j/14 \u00a9 ucles 20145  iron from a blast furnace contains carbon, sulfur, silicon and phosphorus as impurities.  (a)  iron is converted into steel in a basic oxygen converter.   the impurities undergo oxidation.   what is meant by the term oxidation ?   ... ...  [1]  (b)  carbon is oxidised to carbon dioxide. sulfur is oxidised to sulfur dioxide.   explain why these oxides are easily removed from the molten iron.   ... ...  [1]  (c)  phosphorus is converted to phosphorus( v) oxide.  (i)  complete the symbol equation for this reaction. .p   +   5o2   \u2192   2p2o5 [1]  (ii)  is phosphorus( v) oxide an acidic or basic oxide?   give a reason for your answer.   .    . ..  [1]  (d)  phosphorus( v) oxide is a solid.   explain how this oxide is removed from the molten iron.   ... .   ... .   ... ...  [3]  (e)  steel is an alloy.  (i)  state one use of:  mild steel,  . ..  stainless steel.    [2]",
            "11": "11 0620/22/m/j/14 \u00a9 ucles 2014 [turn over (ii)  which diagram, a, b, c or d, best represents an alloy?   put a ring around the correct answer. a b c d [1]  (f)  the table shows the composition of some different brasses. composition of the brassstrength / 108 pa% zinc % copper 10 90 2.6 20 80 3.030 70 3.340 60 3.6   how does the composition of brass affect its strength?   ... ...  [1]  (g)  a student dissolved a sample of brass in concentrated nitric acid.   nitrogen dioxide, no 2, was released. cu  +  4hno3  \u2192  cu(no3)2  +  2no2  +  2h2o  (i)  write a word equation for this reaction. [2]  (ii)  the student added aqueous ammonia to the solution formed until the ammonia was in  excess.   describe what the student would observe.   .    .    . ..  [3]  (iii)  state one source of the nitrogen dioxide in the atmosphere.   . ..  [1] [total: 17]",
            "12": "12 0620/22/m/j/14 \u00a9 ucles 20146  in the 1860s, john newlands listed the elements in order of increasing atomic mass. part of his  table is shown. h 1li 2be 3b 4c 5n 6o 7 f 8na 9mg 10al 11si 12p 13s 14 cl 15k 16ca 17cr 18ti 19mn 20fe 21  (a) (i)   describe the differences between newlands\u2019 table and the periodic table we use today.   .    .    .    .    . ..  [3]  (ii)  what evidence is there, from newlands\u2019 table, that some elements with similar properties  are grouped together?   .    . ..  [1]  (b)  the table below shows some properties of some of the halogens. halogenmelting point / \u00b0cboiling point / \u00b0ccolour chlorine \u2013101 \u20137 yellow-green bromine \u20137 red-browniodine +114 +184 grey-blackastatine +302 +337   deduce:  the colour of astatine,  . ...  the boiling point of bromine,  ... ...  the state of iodine at 190  \u00b0c.  .. [3]",
            "13": "13 0620/22/m/j/14 \u00a9 ucles 2014 [turn over (c)  aqueous chlorine reacts with aqueous potassium bromide. cl 2  +  2kbr  \u2192  br2  +  2kc l  (i)  describe the colour change you would observe in this reaction.   . ..  [1]  (ii)  state the name of the salt formed in this reaction.   . ..  [1]  (iii)  explain why aqueous bromine does not react with aqueous potassium chloride.   .    . ..  [1]  (iv)  the halogens exist as diatomic molecules.   what is meant by the term diatomic ?   . ..  [1] [total: 11]",
            "14": "14 0620/22/m/j/14 \u00a9 ucles 20147  ethanol is an alcohol.  (a)  complete the structure of ethanol showing all atoms and bonds. \u2013 c \u2013 o \u2013 h [1]  (b)  state the name of the products formed when ethanol undergoes incomplete  combustion.  ... and .. . [2]  (c)  ethanol can be manufactured by fermentation or by the hydration of ethene.  (i)  complete the word equation for the manufacture of ethanol from ethene. ethene   +      \u2192   ethanol [1]  (ii)  what conditions are needed for the manufacture of ethanol from ethene?   tick two boxes.  temperature above 100  \u00b0c  room temperature presence of inorganic catalyst presence of yeast presence of hydrogen [2]",
            "15": "15 0620/22/m/j/14 \u00a9 ucles 2014 [turn over (iii)   when ethanol is prepared by fermentation, the fermentation mixture produced contains  ethanol and water.   the boiling point of ethanol is 78  \u00b0c.   describe how fractional distillation can be used to separate ethanol from water.   in your answer, refer to:  \u25cf the apparatus used,  \u25cf changes in state,  \u25cf differences in boiling points.   you may use a diagram.   .    .    .    .    .    .    . ..  [5] [total: 11]",
            "16": "16 0620/22/m/j/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s14_qp_23.pdf": {
            "1": "this document consists of 17 printed pages and 3 blank pages. [turn overib14 06_0620_23/3rp \u00a9 ucles 2014 *1126807358* read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 20. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/23   paper 2 may/june 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/23/m/j/14 \u00a9 ucles 20141 (a)   choose from the list of compounds below to answer the following questions. aluminium oxide calcium carbonate calcium oxide copper( ii) sulfate hydrogen chloride potassium bromide sodium chloride sodium hydroxide   each compound can be used once, more than once or not at all.   which compound:  (i)  reacts with aqueous ammonia to form a light blue precipitate,   . ..  [1]  (ii)  is formed by the decomposition of limestone,   . ..  [1]  (iii)  forms an acidic solution when dissolved in water,   . ..  [1]  (iv)  when electrolysed, gives a red-brown vapour at the anode,   . ..  [1]  (v)  is an oxide of a metal in group iii of the periodic table,   . ..  [1]  (vi)  is a transition element compound?   . ..  [1]  (b) complete the following sentences about compounds using words from the list below.  chemically different \ufb01 xed  mixed physically similar   a compound is a substance which consists of two or more different elements   combined together.   the properties of a compound are  from those of the elements from which it is formed.   in a compound, the elements are combined in  proportions. [3] [total: 9]",
            "3": "3 0620/23/m/j/14 \u00a9 ucles 2014 [turn over2 (a)   calcium chloride, cac l 2, is a salt.   suggest the name of an acid and a base that would react together to make calcium chloride.  acid     base   ... [2]  (b)  calcium chloride absorbs water vapour.   when calcium chloride is heated, it loses its water of crystallisation.   complete the symbol equation for this reaction. include the sign for a reversible reaction. cac l 2.6h2o                   cac l 2   +   . [2]  (c)  a student put some clean iron nails in two test-tubes, as shown in the diagram. she then left  the test-tubes for several weeks. a banhydrous calcium chloride cac l 2cotton wool cotton wool  explain why the nails in tube a did not rust but the nails in tube b rusted.   ... .   ... .   ... ...  [2]  (d)  rust is hydrated iron( iii) oxide.   what does the ( iii) in iron( iii) oxide refer to?   tick one box.  the oxidation state of the oxygen  the oxidation state of the iron the number of atoms of oxygen in a  formula unit of iron( iii) oxide  the number of water molecules in the hydrated iron oxide [1]",
            "4": "4 0620/23/m/j/14 \u00a9 ucles 2014 (e) (i)   the table describes the ease of reduction of some metal oxides with carbon monoxide. lead oxide moderate heating to about 200  \u00b0c needed iron oxide high temperature furnace at 750  \u00b0c needed magnesium oxide temperatures above 1000  \u00b0c needed zinc oxide very high temperature furnace at 900  \u00b0c needed   put these metals in order of their reactivity with carbon monoxide. least reactive most reactive [2]  (ii)  some metal oxides can be reduced by heating with hydrogen gas. cuo   +   h2   \u2192   cu   +   h2o   explain how this equation shows that copper oxide is being reduced.   . ..  [1] [total: 10]",
            "5": "5 0620/23/m/j/14 \u00a9 ucles 2014 [turn over3  the diagram shows the best ph ranges for growing different plants. 4 ph 5 6 7 8 beans carrotscloverpotatoestomatoes  (a) (i)   which two plants grow best in acidic conditions only?   and . .. [1]  (ii)  which ph shown in the diagram above represents a neutral ph?   . ..  [1]  (b) (i)   explain why lime is added to acidic soils.   .    . ..  [2]  (ii)  farmers fertilise soil by adding compounds containing ammonium salts.   explain why adding lime to fertilised soil may cause a loss of nitrogen from the soil.   .    .    . ..  [3]",
            "6": "6 0620/23/m/j/14 \u00a9 ucles 2014 (c)  the graphs below show the rate of uptake of potassium and phosphate ions by plant roots at  different ph values. 34567 ph89 1 0rate of uptake of potassium 34567 ph89 1 0 1 1rate of uptake of phosphorus  (i)  describe the effect of ph on the rate of uptake of potassium by plant roots.   .    . ..  [2]  (ii)  at which ph value is the rate of uptake of phosphorus by plant roots the highest?   . ..  [1] [total: 10]",
            "7": "7 0620/23/m/j/14 \u00a9 ucles 2014 [turn over4  chromatography is used to separate a mixture of coloured dyes.  (a)  three different dye mixtures, a, b and c, were spotted onto a piece of chromatography paper.  two pure dyes, x and y, were also spotted onto the same piece of paper.   the diagram below shows the results of the chromatography. abc xysolvent front base line  (i)  state the name of a piece of apparatus that could be used to spot the dyes onto the paper.   . ..  [1]  (ii)  suggest why the base line was drawn in pencil and not in ink.   . ..  [1]  (iii)  which dye mixture contains both  dye x and dye y?   . ..  [1]  (iv)  which dye mixture does not contain dye x or dye y?   . ..  [1]  (v)  in which mixture, a, b or c, has the greatest number of dyes been separated?   . ..  [1]",
            "8": "8 0620/23/m/j/14 \u00a9 ucles 2014 (b)  the structure of the dye chrysoidine g is shown below. cc cccc c n n n hh h h hcc ccch h hhh n h h  (i)  how many nitrogen atoms are there in a molecule of chrysoidine g?   . ..  [1]  (ii)  complete the table below to calculate the relative molecular mass of chrysoidine g. type of atom number of atoms atomic mass carbon 12 12 12 \u00d7 12 = 144 hydrogennitrogen relative molecular mass =  [2]  (c)  the \ufb01 bres in the chromatography paper are polymers.  (i)  what is meant by the term polymer ?   .    . ..  [1]  (ii)  state the chemical name of the polymer formed from ethene.   . ..  [1] [total: 10]",
            "9": "9 0620/23/m/j/14 \u00a9 ucles 2014 [turn over5  the table shows some properties of the \ufb01 rst four carboxylic acids. acidmolecular formulamelting point / \u00b0cboiling point / \u00b0cdensity in g  / cm3 methanoic acid ch2o2 +10 +101 1.22 ethanoic acid c2h4o2 +17 +118 1.05 propanoic acid c3h6o2 \u201321 0.99 butanoic acid c4h8o2 \u2013 4 +166  (a) (i)   how does the boiling point of these carboxylic acids vary with the number of carbon atoms?   . ..  [1]  (ii)  suggest a value for:  the boiling point of propanoic acid,   \u00b0c   the density of butanoic acid.   g / cm3 [2]  (iii)  is butanoic acid a solid, liquid or gas at room temperature?   use the data in the table to explain your answer.   .    . ..  [1]  (b)   complete the diagram below to show the structure of ethanoic acid.   show all atoms and bonds. h ch hc [1]",
            "10": "10 0620/23/m/j/14 \u00a9 ucles 2014 (c)   the concentration of ethanoic acid can be determined by titration using the apparatus shown  below. a b ethanoic acid  (i)  state the name of the piece of glassware labelled a.    . ..  [1]  (ii)  liquid b is an alkali.   which one of the following compounds is also an alkali?   put a ring around the correct answer.  calcium carbonate  calcium sulfate sodium chloride sodium hydroxide [1]  (iii) describe how you would carry out this titration.   .    .    .    . ..  [2] [total: 9]",
            "11": "11 0620/23/m/j/14 \u00a9 ucles 2014 [turn over6  lead( ii) bromide is a white solid.   part of the structure of lead( ii) bromide is shown below. br \u2013 br \u2013br \u2013 br \u2013pb2+br \u2013 br \u2013br \u2013 br \u2013pb2+ br \u2013br \u2013 pb2+br \u2013br \u2013 pb2+pb2+pb2+  (a)  deduce the simplest formula for lead( ii) bromide.   ... ...  [1]  (b)  a student electrolysed lead( ii) bromide in a fume cupboard using the apparatus shown below. anode cathode lead( ii) bromide  (i)  why is heat needed for this electrolysis?   . ..  [1]  (ii)  suggest the name of a substance that could be used for the electrodes.   . ..  [1]  (iii)  state the name of the products of electrolysis at:  the anode,  .. .  the cathode.   ..  [1] ",
            "12": "12 0620/23/m/j/14 \u00a9 ucles 2014 (c)  items can be electroplated with silver using the apparatus shown below. b c a drod of silve r alloy rod electrolyte+ \u2013  (i)  on the diagram, which letter, a, b, c or d, is the cathode?   . ..  [1]  (ii)  what would you observe during the experiment at the:  positive electrode,  .    negative electrode?   .  [2]  (iii)  the electrolyte used is aqueous silver cyanide, agcn.   calculate the relative formula mass of silver cyanide.   you must show all your working. [2] [total: 9]",
            "13": "13 0620/23/m/j/14 \u00a9 ucles 2014 [turn over7  dmitri mendeleev published his \ufb01 rst periodic table in 1869.   part of this table is shown below.     ti = 50     v  = 51    cr = 52    mn = 55    fe = 56    co = 59 h = 1   cu = 63.4  be = 9.4 mg = 24 zn = 65.2  b = 11 a l = 27.4 ?   c = 12 si = 28 ?  n = 14 p = 31 as = 75  o = 16 s = 32 se = 79.4  f = 19 c l = 35.5 br = 80  li = 7 na = 23 k = 39 rb = 85.4  (a) (i)   what differences are there between mendeleev\u2019s table and the periodic table we use  today?   .    .    .    .    . ..  [4]  (ii)  state the names of any two elements in the table above which exist as diatomic molecules.   and . .. [1]  (b)  titanium is a transition element. sodium is a metal in group i of the periodic table.   state three  differences in the physical properties of titanium and sodium.  1  ... ..  2  ... ..  3  ... .. [3]",
            "14": "14 0620/23/m/j/14 \u00a9 ucles 2014 (c)   titanium( iv) oxide reacts with a mixture of chlorine and carbon.   the products are titanium( iv) chloride, tic l 4, and a gas which turns limewater milky.   complete the symbol equation for this reaction. tio2   +   .c l 2   +   c   \u2192   tic l 4   +   ... [2]  (d)  titanium is extracted from titanium( iv) chloride by reduction with molten sodium in the presence  of argon.   suggest why this reaction is carried out in the presence of argon.   ... .   ... ...  [2] [total: 12]",
            "15": "15 0620/23/m/j/14 \u00a9 ucles 2014 [turn over8  sodium sulfate is a solid with a high melting point.   sodium sulfate conducts electricity when molten but not when solid.  (a)  what type of structure is sodium sulfate?  tick one box.  structure of separated atoms simple molecular structure giant ionic structure giant covalent structure [1]  (b)  describe a test for sulfate ions.  test   .  result  ..  [2]  (c)  describe how simple distillation is used to separate water from an aqueous solution of sodium  sulfate.   in your answer, refer to:  \u25cf the apparatus used,  \u25cf changes in state,  \u25cf differences in boiling points.   you may use a diagram.   ... .   ... .   ... .   ... .   ... .   ... .   ... ...  [5]",
            "16": "16 0620/23/m/j/14 \u00a9 ucles 2014 (d)  what would you observe when a piece of blue cobalt chloride paper is dipped into water?   ... ...  [1]  (e)  describe how impure water is treated so that it can be used for drinking.   ... .   ... ...  [2] [total: 11]",
            "17": "17 0620/23/m/j/14 \u00a9 ucles 2014blank page",
            "18": "18 0620/23/m/j/14 \u00a9 ucles 2014blank page",
            "19": "19 0620/23/m/j/14 \u00a9 ucles 2014blank page",
            "20": "20 0620/23/m/j/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s14_qp_31.pdf": {
            "1": "this document consists of 13 printed pages and 3 blank pages. [turn overib14 06_0620_31/2rp \u00a9 ucles 2014 *3226538232* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) may/june 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/31/m/j/14 \u00a9 ucles 20141  the table below gives the composition of six particles which are either atoms or ions. particle number of protons number of neutrons number of electrons a 33 40 33 b 19 20 18 c 34 45 36 d 33 42 33 e 13 14 13 f 24 28 21  (a)  which particles are atoms? explain your choice.   ... .   ... ...  [2]  (b)  which particle is a negative ion and why has this particle got a negative charge?   ... .   ... ...  [2]  (c)  which particles are positive ions?   ... ...  [1]  (d)  explain why particle a and particle d are isotopes.   ... .   ... ...  [2] [total: 7]",
            "3": "3 0620/31/m/j/14 \u00a9 ucles 2014 [turn over2 (a)  water is needed for industry and in the home.  (i)  rain water is collected in reservoirs. how is it treated before entering the water supply?   .    . ..  [2]  (ii)  state two industrial uses of water.   .    . ..  [2]  (iii) state two uses of water in the home.   .    . ..  [1]  (b)  in many regions, drinking water is obtained by the distillation of sea-water. explain how  distillation separates the water from sea-water.   ... .   ... .   ... ...  [2] [total: 7]",
            "4": "4 0620/31/m/j/14 \u00a9 ucles 20143 (a)  different gases diffuse at different speeds.  (i)  what is meant by the term diffusion ?   .    . ..  [1]  (ii)  what property of a gas molecule affects the speed at which it diffuses?   . ..  [1]  (b)  helium is a gas used to \ufb01 ll balloons. it is present in the air in very small quantities. diffusion can  be used to separate it from the air.   air at 1000  \u00b0c is on one side of a porous barrier. the air which passes through the barrier has  a larger amount of helium in it.  (i)  why does the air on the other side of the barrier contain more helium?   . ..  [1]  (ii)  why is it an advantage to have the air at a high temperature?   .    . ..  [1]  (c)  most helium is obtained from natural gas found in the usa. natural gas contains methane and  7% helium. one possible way to obtain the helium would be to burn the methane.  (i)  write an equation for the complete combustion of methane.   . ..  [1]  (ii)  suggest why this would not be a suitable method to obtain the helium.   .    . ..  [1]  (iii)  suggest another method, other than diffusion, by which helium could be separated from  the mixture of gases in natural gas.   . ..  [1] [total: 7]",
            "5": "5 0620/31/m/j/14 \u00a9 ucles 2014 [turn over4  in the periodic table, the elements are arranged in columns called groups and in rows called  periods.  (a) (i)   complete the table for some of the elements in period 3. group number i ii iii iv v vi vii symbol na mg a l si p s c l number of  valency electrons valency [2]  (ii)  what is the relationship between the group number and the number of valency electrons?   .    . ..  [1]  (iii)  explain the relationship between the number of valency electrons and the valency  for the elements na to a l,   .    .    .   for the elements p to c l.   .    .    .  [4]  (b)  across a period, the elements change from metallic to non-metallic.  (i)  describe how the type of oxide changes across this period.   .    . ..  [2]  (ii)  describe how the type of bonding in the chlorides formed by these elements changes  across this period.   .    . ..  [2] [total: 11]",
            "6": "6 0620/31/m/j/14 \u00a9 ucles 2014blank page",
            "7": "7 0620/31/m/j/14 \u00a9 ucles 2014 [turn over5  zinc is obtained from the ore, zinc blende, zns.  (a)  describe the extraction of zinc from its ore, zinc blende. include at least one balanced equation  in your description.   ... .   ... .   ... .   ... .   ... ...  [5]  (b)  state two major uses of zinc.   ... .   ... ...  [2] [total: 7]",
            "8": "8 0620/31/m/j/14 \u00a9 ucles 20146  hydrogen peroxide decomposes to form water and oxygen. this reaction is catalysed by  manganese( iv) oxide. 2h2o2(aq)  \u2192  2h2o(l)  +  o2(g)   the rate of this reaction can be investigated using the following apparatus. aqueous hydrogen peroxide and manganese( iv) oxideoxygen gas   40  cm3 of aqueous hydrogen peroxide was put in the \ufb02 ask and 0.1  g of small lumps of manganese( iv)  oxide was added. the volume of oxygen collected was measured every 30 seconds. the results were plotted to give the graph shown below. volume of oxygen time00 t1 t2 t3  (a) (i)   how do the rates at times t1, t2 and t3 differ?   .    . ..  [2]  (ii)  explain the trend in reaction rate that you described in (a)(i) .   .    .    . ..  [2]",
            "9": "9 0620/31/m/j/14 \u00a9 ucles 2014 [turn over (b)  the experiment was repeated using 0.1  g of \ufb01 nely powdered manganese( iv) oxide. all the  other variables were kept the same.  (i)  on the axes opposite, sketch the graph that would be expected. [2]  (ii)  explain the shape of this graph. ..   .    .    . ..  [2]  (c)  describe how you could show that the catalyst, manganese( iv) oxide, was not used up in the  reaction. manganese( iv) oxide is insoluble in water.   ... .   ... .   ... .   ... .   ... ...  [4]  (d)  in the \ufb01 rst experiment, the maximum volume of oxygen produced was 96  cm3 measured at  r.t.p. calculate the concentration of the aqueous hydrogen peroxide in mol  / dm3. 2h2o2(aq)  \u2192  2h2o(l)  +  o2(g)   number of moles of o2 formed =  ..  [1]   number of moles of h2o2 in 40  cm3 of solution =  .  [1]   concentration of the aqueous hydrogen peroxide in mol  / dm3 =  ..  [1] [total: 15]",
            "10": "10 0620/31/m/j/14 \u00a9 ucles 20147  one way of establishing a reactivity series is by displacement reactions.  (a)  a series of experiments was carried out using the metals lead, magnesium, zinc and silver.  each metal was added in turn to aqueous solutions of the metal nitrates.   the order of reactivity was found to be: magnesium most reactive zinc\u2193lead silver least reactive  (i)  complete the table.  \u0016= reacts  \u001a= does not react metal aqueous  solutionlead pbmagnesium mgzinc znsilver ag lead( ii) nitrate\u0016\u0016\u001a magnesium nitrate zinc nitrate silver nitrate [3]  (ii)  displacement reactions are redox reactions.   on the following equation, draw a ring around the reducing agent and an arrow  to show  the change which is oxidation. zn   +   pb2+   \u2192   zn2+   +   pb [2]  (iii)  complete the following ionic equation. zn  +  2ag+  \u2192  ...  +  ... [1]",
            "11": "11 0620/31/m/j/14 \u00a9 ucles 2014 [turn over (b)  another way of determining the order of reactivity of metals is by measuring the voltage and  polarity of simple cells. the polarity of a cell is shown by which metal is the positive electrode and which metal is the negative electrode. an example of a simple cell is shown below. zinc electrode lead electrode electrolyte of dilute acidvoltmeter + \u2013v  (i)  mark on the above diagram the direction of the electron \ufb02 ow. [1]  (ii)  explain, in terms of electron transfer, why the more reactive metal is always the negative  electrode.   .    .    . ..  [2]  (iii)  the following table gives the polarity of cells using the metals zinc, lead, copper and  manganese. cell electrode 1 polarity electrode 2 polarity a zinc \u2013 lead + b manganese \u2013 lead + c copper + lead \u2013   what information about the order of reactivity of these four metals can be deduced from  the table?   .    .    . ..  [2]  (iv)  what additional information is needed to establish the order of reactivity of these four  metals using cells?   . ..  [1] [total: 12]",
            "12": "12 0620/31/m/j/14 \u00a9 ucles 20148  polymers are made by the polymerisation of simple molecules called monomers.  (a) (i)   the structural formula of a polymer is given below.  nch ch3ch ch3   this polymer is made by addition polymerisation. draw the structural formula of its  monomer. [1]  (ii)  the two monomers shown below form a nylon which is a condensation polymer.  nh2 h2n cooh hooc   draw its structural formula showing one repeat unit of the polymer. [3]  (iii)  name the natural macromolecule which contains the same linkage as nylon.   . ..  [1]  (iv)  explain the difference between addition polymerisation and condensation polymerisation.   .    .    . ..  [2]",
            "13": "13 0620/31/m/j/14 \u00a9 ucles 2014 [turn over (b)  many polymers are non-biodegradable.  (i)  explain the term non-biodegradable .   .    . ..  [2]  (ii)  state three  problems caused by the disposal of non-biodegradable polymers.   .    .    . ..  [3]  (c)  storage tanks for cold water are now made from polymers because they are cheaper than  metal tanks. suggest two other advantages of making cold water tanks from polymers.   ... .   ... ...  [2] [total: 14]",
            "14": "14 0620/31/m/j/14 \u00a9 ucles 2014blank page",
            "15": "15 0620/31/m/j/14 \u00a9 ucles 2014blank page",
            "16": "16 0620/31/m/j/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s14_qp_32.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib14 06_0620_32/4rp \u00a9 ucles 2014 *5879467154* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) may/june 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/32/m/j/14 \u00a9 ucles 20141  the table below gives the electron distributions of atoms of different elements. element electron distribution a 2 + 7 b 2 + 8 + 4 c 2 + 8 + 8 + 1 d 2 + 8 + 18 + 5 e 2 + 8 + 18 + 7 f 2 + 8 + 18 + 18 + 8   for each of the following, select an element or elements from the table that matches the description.  each element may be selected once, more than once or not at all.  (a)  these two elements are in the same group.   ... ...  [1]  (b)  this element forms a \ufb02 uoride with a formula of the type xf3.   ... ...  [1]  (c)  this element reacts violently with cold water.   ... ...  [1]  (d)  this element has a macromolecular structure similar to that of diamond.   ... ...  [1]  (e)  the only oxidation state of this element is 0.   ... ...  [1]  (f)  this element is bromine.   ... ...  [1]  (g)  this element is a good conductor of electricity.   ... ...  [1] [total: 7]",
            "3": "3 0620/32/m/j/14 \u00a9 ucles 2014 [turn over2 (a)  natural gas, which is mainly methane, is a fossil fuel.  (i)  what is meant by the term fuel  ?   .    . ..  [1]  (ii)  name two other fossil fuels.   . ..  [2]  (iii)  name a solid  fuel which is not a fossil fuel.   . ..  [1]  (b)  fossil fuels are formed by the anaerobic decomposition of organic matter. anaerobic means in  the absence of oxygen.  (i)  the organic matter contains hydrogen and carbon. suggest the products that would be formed if the decomposition occurred in the presence of oxygen.   . ..  [2]  (ii)  what are the two main disadvantages in the widespread use of fossil fuels?   .    .    . ..  [2] [total: 8]",
            "4": "4 0620/32/m/j/14 \u00a9 ucles 20143  plant growth is improved by the availability of essential elements, such as nitrogen, and by the soil  having a suitable ph.  (a)  nitrogen-based fertilisers are made from ammonia. ammonia is manufactured by the haber process.  (i)  describe the haber process giving reaction conditions and a balanced equation.   (do not discuss reaction rate and yield.)   .    .    .    .    . ..  [5]  (ii)  fertilisers contain nitrogen.   name the other two elements essential for plant growth commonly found in fertilisers.   . ..  [2]  (b)  crops do not grow well if the soil is too acidic.  (i)  one cause of acidity in soil is acid rain. explain how acid rain is formed.   .    .    .    . ..  [3]  (ii)  name two bases which are used to increase the ph of acidic soils.   . ..  [2] [total: 12]",
            "5": "5 0620/32/m/j/14 \u00a9 ucles 2014 [turn over4  propanoic acid is a carboxylic acid. its formula is ch3\u2013ch2\u2013cooh.  (a)  propanoic acid is the third member of the homologous series of carboxylic acids.  (i)  give the name and structural formula of the fourth member of this series.  name   ...  formula  . .  [2]    (ii)  members of a homologous series have very similar chemical properties.   state three  other characteristics of a homologous series.   .    .    .    . ..  [3]  (b)  carboxylic acids can be made by the oxidation of alcohols.  (i)  draw the structural formula of the alcohol which can be oxidised to propanoic acid.   show all atoms and bonds. [1]  (ii)  name a reagent, other than oxygen, which can oxidise alcohols to carboxylic acids.   . ..  [2]",
            "6": "6 0620/32/m/j/14 \u00a9 ucles 2014 (c)  complete the following equations for some of the reactions of propanoic acid.   the salts of this acid are called propanoates.  (i)  zinc  +  propanoic acid  \u2192  ...  ...  +  hydrogen [1]  (ii) calcium  +  propanoic  \u2192  ...  ...  +  ...  oxide acid [1]  (iii) lioh  +  ch3ch2cooh  \u2192  ...  +  ... [1]  (d)  a piece of magnesium was added to 100  cm3 of an aqueous acid. the time taken for the metal  to react completely was measured. this experiment was repeated using different aqueous acids. the same volume of acid was used in each experiment and the pieces of magnesium used were identical. in one experiment the reaction was carried out at a different temperature.  experiment acidconcentration in mol  / dm3temperature / \u00b0ctime / minutes a propanoic 1.0 20 5 b propanoic 1.0 30 3 c propanoic 0.5 20 8 d hydrochloric 1.0 20 1   explain the following in terms of collision rate between reacting particles.  (i)  why is the rate in experiment c slower than the rate in experiment a?   .    .    . ..  [2]  (ii)  why is the rate in experiment b faster than the rate in experiment a?   .    .    . ..  [2]  (iii)  why is the rate in experiment d faster than the rate in experiment a?   .    .    . ..  [3] [total: 18]",
            "7": "7 0620/32/m/j/14 \u00a9 ucles 2014 [turn over5  carbonyl chloride is made from carbon monoxide and chlorine. co(g)  +  c l 2(g)    coc l 2(g)  (a)  two methods of preparing carbon monoxide are from methane and oxygen, and from methane  and steam.  (i)  the reaction between methane and oxygen can also form carbon dioxide. how can carbon  monoxide be made instead of carbon dioxide?   . ..  [1]  (ii)  the following reaction is used to make carbon monoxide and hydrogen.   the reaction is carried out at 1100  \u00b0c and normal pressure. ch4(g)  +  h2o(g)    co(g)  +  3h2(g)   the reaction is reversible and comes to equilibrium. suggest why a high temperature is  used.   .    .    . ..  [2]  (iii)  what is the disadvantage of using a high pressure for the reaction given in (a)(ii) ?   .    . ..  [2]  (b)  chlorine is made by the electrolysis of concentrated aqueous sodium chloride.   describe this electrolysis. write ionic equations for the reactions at the electrodes and name  the sodium compound formed.   ... .   ... .   ... .   ... .   ... .   ... ...  [5]",
            "8": "8 0620/32/m/j/14 \u00a9 ucles 2014 (c)  the structural formula of carbonyl chloride is given below. cocl cl   draw a diagram showing the arrangement of the valency electrons around the atoms in one  molecule of this covalent compound.   use \u25cb to represent an electron from an oxygen atom.   use \u00d7 to represent an electron from a chlorine atom.   use \u25cf to represent an electron from a carbon atom. [3] [total: 13] 6  scandium, proton number 21, is not a typical transition element.  (a)  scandium is a low density metal which has only one oxidation state in its compounds. scandium  compounds are white solids which form colourless solutions. titanium, the next metal in the period, is a far more typical transition element. how would the properties of titanium differ from those of scandium?   ... .   ... .   ... .   ... ...  [3]",
            "9": "9 0620/32/m/j/14 \u00a9 ucles 2014 [turn over (b)  scandium \ufb02 uoride is an ionic compound. the valency of scandium in scandium \ufb02 uoride is  three.   draw a diagram which shows the formula of this compound, the charges on the ions and the  arrangement of the valency electrons around the negative ions.   use \u00d7 to represent an electron from a \ufb02 uorine atom.   use \u25cb to represent an electron from a scandium atom. [3]  (c)  scandium oxide is insoluble in water. describe how you could show that it is an amphoteric  oxide.   ... .   ... .   ... .   ... ...  [3] [total: 9]",
            "10": "10 0620/32/m/j/14 \u00a9 ucles 20147  the soluble salt hydrated lithium sulfate is made by titration from the soluble base lithium hydroxide. burette filled with sulfuric acid aqueous lithium hydroxideand a few drops of a ph indicatorconical flask  (a)  the sulfuric acid is added slowly from the burette until the indicator just changes colour. the  volume of sulfuric acid needed to just neutralise the lithium hydroxide is noted.   describe how you would continue the experiment to obtain pure dry crystals of hydrated lithium  sulfate.   ... .   ... .   ... .   ... .   ... .   ... ...  [5]  (b)  using 25.0  cm3 of aqueous lithium hydroxide, concentration 2.48  mol  / dm3, 2.20  g of hydrated  lithium sulfate was obtained.   calculate the percentage yield, giving your answer to one decimal place. 2lioh  +  h2so4  \u2192  li2so4  +  2h2o li2so4  +  h2o  \u2192  li2so4.h2o   number of moles of lioh used = ...   number of moles of li2so4.h2o which could be formed = ...   mass of one mole of li2so4.h2o = 128  g   maximum yield of li2so4.h2o = ... g  percentage yield = ...% [4]",
            "11": "11 0620/32/m/j/14 \u00a9 ucles 2014 [turn over (c)  an experiment was carried out to show that the formula of the hydrated salt is li2so4.h2o.  a sample of the hydrated salt was weighed and its mass recorded. it was then heated and the anhydrous salt was weighed. this procedure was repeated until two consecutive masses were the same. this procedure is called \u2018heating to constant mass\u2019.  (i)  what is the reason for heating to constant mass?   . ..  [1]  (ii)  the mass of the hydrated salt is m 1 and the mass of the anhydrous salt is m2. explain how  you could show that the hydrated salt has one mole of water of crystallisation per mole of  the anhydrous salt.   .    .    . ..  [3] [total: 13]",
            "12": "12 0620/32/m/j/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s14_qp_33.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib14 06_0620_33/2rp \u00a9 ucles 2014 *4182021420* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) may/june 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/33/m/j/14 \u00a9 ucles 20141  choose a gas from the following list to answer the questions below. each gas may be used once,  more than once or not at all. ammonia       carbon dioxide       carbon monoxide       \ufb02 uorine hydrogen       krypton       nitrogen       propene       sulfur dioxide  (a)  it is a product of respiration.  .. ..  [1]  (b)  it polymerises to form a poly(alkene).  ..  [1]  (c)  it is a noble gas.  ... ...  [1]  (d)  it is the main component of air.    [1]  (e)  it is a very reactive non-metal.  .  [1]  (f)  it is used to kill micro-organisms in fruit juice.  .  [1]  (g)  it burns to form water as the only product.  ..  [1] [total: 7]",
            "3": "3 0620/33/m/j/14 \u00a9 ucles 2014 [turn over2  explain each of the following in terms of the kinetic particle theory.  (a)  the rate of most reactions increases at higher temperatures.   ... .   ... .   ... .   ... ...  [3]  (b)  a liquid has a \ufb01 xed volume but takes up the shape of the container. a gas takes up the shape  of the container but it does not have a \ufb01 xed volume. liquid gas   ... .   ... .   ... .   ... .   ... ...  [3] [total: 6]",
            "4": "4 0620/33/m/j/14 \u00a9 ucles 20143 (a)  biological catalysts produced by microbes cause food to deteriorate and decay.  (i)  what is the name of these biological catalysts?   . ..  [1]  (ii)  freezing does not kill the microbes.   suggest why freezing is still a very effective way of preserving food.   .    . ..  [2]  (b)  pea seeds grow in pods on pea plants.   freshly picked pea seeds contain a sugar. the sugar can form a polymer.   give the structural formula of the polymer and name the other product of this polymerisation  reaction.   you may represent the sugar by the formula: oh ho   structural formula of the polymer   other product   ...  [3]",
            "5": "5 0620/33/m/j/14 \u00a9 ucles 2014 [turn over (c)  describe how the pea plant makes a sugar such as glucose.   ... .   ... .   ... .   ... .   ... ...  [3] [total: 9] 4  iron from a blast furnace contains about 5% of the impurities \u2013 carbon, silicon, phosphorus and sulfur.  most of this impure iron is used to make steels, such as mild steel, and a very small percentage is used to make pure iron.  (a)  calcium oxide and oxygen are used to remove the impurities from the iron produced in the blast furnace.  (i)  state how these chemicals are manufactured.  calcium oxide  ... ...   .   oxygen  .. ..   .  [3]  (ii)  describe how these two chemicals remove the four impurities. include at least one equation in your answer.   .    .    .    .    .    .    . ..  [5]",
            "6": "6 0620/33/m/j/14 \u00a9 ucles 2014 (b) (i)   describe the structure of a typical metal such as iron. you may include a diagram.   .    .   [2]  (ii)  explain why pure iron is malleable.   .    . ..  [2]  (iii)  mild steel is an alloy of iron and carbon.   suggest why mild steel is harder than pure iron.   .    .    . ..  [2] [total: 14]",
            "7": "7 0620/33/m/j/14 \u00a9 ucles 2014 [turn over5  ammonia is made by the haber process. n2(g)  +  3h2(g)    2nh3(g)   the forward reaction is exothermic.   the conditions in the reaction chamber are:  \u25cf a pressure of 200 atmospheres,  \u25cf a catalyst of finely divided iron,  \u25cf a temperature of 400 to 450  \u00b0c.  (a)  what are the two advantages of using a high pressure? give a reason for both.  advantage 1  . ..  reason  ... .   ... .  advantage 2  . ..  reason  ... .   ... . [4]  (b)  a higher temperature would give a faster reaction rate.   why is a higher temperature not used?   ... .   ... .   ... ...  [3]  (c) (i)   why is the iron catalyst used as a \ufb01 ne powder?   .    . ..  [1]  (ii)  give two reasons why a catalyst is used.   .    .    .    . ..  [2]",
            "8": "8 0620/33/m/j/14 \u00a9 ucles 2014 (d)  the equilibrium mixture leaving the reaction chamber contains 15% ammonia. suggest how  the ammonia could be separated from the mixture.  boiling point  / \u00b0c hydrogen \u2013253nitrogen \u2013196ammonia \u201333   ... .   ... ...  [2]  (e)  ammonia is used to make nitrogen tri \ufb02 uoride, nf 3.   nitrogen tri \ufb02 uoride is essential to the electronics industry. it is made by the following reaction. hn hh+ +ff \u2192 ff ffhf hf hfn f f f   determine if the above reaction is exothermic or endothermic using the following bond energies  and by completing the following table. the \ufb01 rst line has been done as an example.   bond energy is the amount of energy, in kj  / mole, needed to break or make one mole of the  bond. bond bond energy in kj  / mole n \u2013 h 390 f \u2013 f 155 n \u2013 f 280 h \u2013 f 565 bond energy change  / kj n \u2013 h (3 \u00d7 390) = 1170 f \u2013 f n \u2013 f h \u2013 f   ... .   ... ...  [4] [total: 16]",
            "9": "9 0620/33/m/j/14 \u00a9 ucles 2014 [turn over6  the alkanes are a family of saturated hydrocarbons. their reactions include combustion, cracking  and substitution.  (a) (i)   what is meant by the term hydrocarbon ?   . ..  [1]  (ii)  what is meant by the term saturated  ?   . ..  [1]  (b) (i)   what is the general formula for the homologous series of alkanes?   . ..  [1]  (ii)  calculate the mass of one mole of an alkane with 14 carbon atoms.   .    . ..  [2]  (c)  the complete combustion of hydrocarbons produces carbon dioxide and water only.  (i)  write the equation for the complete combustion of nonane, c9h20.   . ..  [2]  (ii)  20  cm3 of a gaseous hydrocarbon was mixed with an excess of oxygen, 200  cm3. the  mixture was ignited. after cooling, 40  cm3 of oxygen and 100  cm3 of carbon dioxide  remained. deduce the formula of the hydrocarbon and the equation for its combustion. all volumes were measured at r.t.p..   .    .    .    .    . ..  [3]",
            "10": "10 0620/33/m/j/14 \u00a9 ucles 2014 (d)  cracking is used to obtain short-chain alkanes, alkenes and hydrogen from long-chain alkanes.  (i)  give a use for each of the three products listed above.  short-chain alkanes  . ...  alkenes  . ..  hydrogen   ...  [3]  (ii)  write an equation for the cracking of decane, c10h22, which produces two different alkenes  and hydrogen as the only products.   . ..  [1]  (e)  chlorine reacts with propane in a substitution reaction to form 1-chloropropane. ch3 \u2013 ch2 \u2013 ch3  +  c l 2  \u2192  ch3 \u2013 ch2 \u2013 ch2 \u2013 cl  +  hc l  (i)  what is the essential condition for the above reaction?   . ..  [1]  (ii)  there is more than one possible substitution reaction between chlorine and propane.  suggest the structural formula of a different product.   . ..  [1] [total: 16]",
            "11": "11 0620/33/m/j/14 \u00a9 ucles 2014 [turn over7  aluminium is obtained from puri \ufb01 ed alumina, a l 2o3, by electrolysis.  (a)  alumina is obtained from the main ore of aluminium.   state the name of this ore.   ... ...  [1]  (b)  describe the extraction of aluminium from alumina. include the electrolyte, the electrodes and  the reactions at the electrodes.   ... .   ... .   ... .   ... .   ... .   ... .   ... ...  [6]  (c) aluminium is resistant to corrosion. it is protected by an oxide layer on its surface.   the thickness of this oxide layer can be increased by anodising.  (i)  state a use of aluminium due to its resistance to corrosion.   . ..  [1]  (ii)  anodising is an electrolytic process. dilute sulfuric acid is electrolysed with an aluminium  object as the anode. the thickness of the oxide layer is increased. complete the equations for the reactions at the aluminium anode.  ...oh \u2013  \u2192  o2  +  2h2o  +  ..e\u2013  a l  +  .  \u2192  . a l 2o3 [4] [total: 12]",
            "12": "12 0620/33/m/j/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s14_qp_51.pdf": {
            "1": "this document consists of 6 printed pages and 2 blank pages. [turn overib14 06_0620_51/4rp \u00a9 ucles 2014 *5760352473* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test may/june 2014  1 hour 15 minutes candidates answer on the question paper.additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/51/m/j/14 \u00a9 ucles 20141  you are going to investigate what happens when dilute hydrochloric acid reacts with an aqueous solution r, containing two different substances s and t.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out three experiments.  (a)  experiment 1   using a measuring cylinder, pour 25  cm3 of solution r into the conical \ufb02 ask. add \ufb01 ve drops of  the phenolphthalein indicator to the \ufb02 ask.   fill the burette with hydrochloric acid to the 0.0  cm3 mark. using the burette, add hydrochloric  acid to solution r and shake the \ufb02 ask. continue to add hydrochloric acid to the \ufb02 ask until the  colour just disappears.   record the volume of hydrochloric acid added when the indicator changes colour.   keep the mixture  in the \ufb02 ask for experiment 2. burette readings \ufb01 nal volume  / cm3 initial volume  / cm3 difference  / cm3 [3]  (b)  experiment 2   add four drops of methyl orange indicator to the mixture in the \ufb02 ask from experiment 1.   check that the burette reading is the same as your \ufb01 nal reading in experiment 1. this is the  initial volume reading for experiment 2.   using the burette, add hydrochloric acid to the mixture in the \ufb02 ask and shake the mixture.   record the volume of hydrochloric acid added when the indicator just changes colour. burette readings \ufb01 nal volume  / cm3 initial volume  / cm3 difference  / cm3 [4]  (c)  experiment 3   pour about 5  cm3 of solution r into a test-tube. using a teat pipette, add hydrochloric acid to  the solution. note any observations.   ... ...  [1]",
            "3": "3 0620/51/m/j/14 \u00a9 ucles 2014 [turn over (d) (i)   when phenolphthalein indicator was used in experiment 1 the colour changed  from   to  . [2]  (ii)  what was the colour of the indicator at the end-point in experiment 2?   . ..  [1]  (e) (i)  what type of substances are s and t?   . ..  [1]  (ii)  what conclusion can you draw from experiment 3?   . ..  [1]  (f)  the volume of hydrochloric acid added in experiment 1 reacted with all of substance s and half  of substance t.   the volume of hydrochloric acid in experiment 2 reacted with half of substance t.  (i)  work out the volume of hydrochloric acid which reacted with substance s.   . ..  [2]  (ii)  work out the volume of hydrochloric acid which reacted with substance t.   . ..  [1]  (iii)  compare the volumes of hydrochloric acid which reacted with substances s and t.   .    . ..  [1]  (g) (i)   predict the volume of hydrochloric acid which would be added in experiments 1 and 2 if  the experiments were repeated using 100  cm3 of solution r. explain your answer.  experiment 1   ..  experiment 2   ..  explanation  . ..  [3]  (ii)  suggest a practical problem that would occur when carrying out these repeat experiments  and how you could solve this problem.   .    . ..  [2] [total: 22]",
            "4": "4 0620/51/m/j/14 \u00a9 ucles 20142  you are provided with solid u, which is a metal salt.  carry out the following tests on u, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solid u (a)  describe the appearance of solid u.   [2] (b)  place half of solid u in a test-tube.   heat the test-tube gently at \ufb01 rst and then  more strongly. ..   [2] (c)  add the rest of solid u to about 8  cm3 of  distilled water in a test-tube.   stopper the test-tube and shake the  contents until dissolved.   divide the solution into four equal portions  in separate test-tubes and carry out the following tests.   add several drops of aqueous  sodium hydroxide to the \ufb01 rst portion of the  solution and shake the test-tube.   then add about 1  cm3 of hydrogen peroxide  solution to the mixture.    test the gas given off. ..  ..   [5] (d)  add excess aqueous ammonia to the  second portion of the solution.   [1] (e)  add about 1  cm3 of dilute nitric acid to the  third portion of the solution followed by about 1  cm3 of barium nitrate solution.   [2] (f)  add about 1  cm3 of dilute nitric acid to the  fourth portion of the solution followed by about 1  cm3 of silver nitrate solution.   [1]",
            "5": "5 0620/51/m/j/14 \u00a9 ucles 2014 [turn over (g)  what does test (f) tell you about solid u?   ... ...  [1]  (h)  name the gas given off in test (c).   ... ...  [1]  (i)  what conclusions can you draw about solid u?   ... .   ... ...  [3] [total: 18]",
            "6": "6 0620/51/m/j/14blank page \u00a9 ucles 2014",
            "7": "7 0620/51/m/j/14blank page \u00a9 ucles 2014",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/51/m/j/14notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2014"
        },
        "0620_s14_qp_52.pdf": {
            "1": "this document consists of 7 printed pages and 1 blank page. [turn overib14 06_0620_52/3rp \u00a9 ucles 2014 *1093878163* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test may/june 2014  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/52/m/j/14 \u00a9 ucles 20141  you are going to investigate the temperature rise produced when different lengths of magnesium  ribbon react with excess dilute sulfuric acid.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out \ufb01 ve experiments.  (a)  experiment 1   using a measuring cylinder, pour 20  cm3 of dilute sulfuric acid into the beaker. measure the  initial temperature of the acid and record it in the table below. add the 2  cm length of magnesium  ribbon to the acid in the beaker, and stir the mixture with the thermometer.   measure the highest temperature reached and record it in the table.   remove the thermometer and rinse out the beaker with water.  (b)  experiment 2   repeat experiment 1, using the 3  cm length of magnesium ribbon. record the initial and  highest temperatures in the table.  (c)  experiment 3   repeat experiment 1, using the 4  cm length of magnesium ribbon. record the temperatures in  the table.  (d)  experiment 4   repeat experiment 1, using the 6  cm length of magnesium ribbon. record the temperatures in  the table.  (e)  experiment 5   repeat experiment 1, using the 7  cm length of magnesium ribbon. record the temperatures in  the table.   complete the table. experimentinitial temperature / \u00b0chighest temperature / \u00b0cchange in temperature / \u00b0c 1 2345 [5]",
            "3": "3 0620/52/m/j/14 \u00a9 ucles 2014 [turn over (f)  plot the results you have obtained on the grid below. draw a straight line of best \ufb01 t through the  points. 30 20 10 0 length of magnesium ribbon  / cmchange in temperature  / \u00b0c [4]  (g)  from your graph , deduce the expected change in temperature if experiment 1 was repeated  using a 5  cm length of magnesium ribbon.   show clearly on the graph  how you worked out your answer.   ... ...  [2]  (h)  give two observations when magnesium reacts with dilute sulfuric acid.  1  ... ..  2  ...   [2]",
            "4": "4 0620/52/m/j/14 \u00a9 ucles 2014 (i) (i)   which experiment gave the greatest change in temperature?   . ..  [1]  (ii)  suggest why the change in temperature was greatest in this experiment.   .    . ..  [1]  (j)  what difference would be observed if experiment 1 was repeated using an equal mass of  magnesium powder? explain your answer.   ... .   ... ...  [2]  (k)  draw a diagram of apparatus you could use to collect and measure the volume of gas given off  in the reaction. [2]  (l)  state one source of error in the results obtained in experiments 1-5. give one improvement to  reduce this source of error.  error  ...   improvement  . ...  [2] [total: 21]",
            "5": "5 0620/52/m/j/14 \u00a9 ucles 2014 [turn over2  you are provided with mixture e. e consists of two solids, f and g. solid f is water-soluble and  solid g is insoluble.   carry out the following tests on e, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on the mixture e (a)  describe the appearance of the mixture.   [1] (b)  place a little of mixture e in a test-tube.   heat the mixture gently at \ufb01 rst then more  strongly for about 1 minute. after 1 minute, test the gas given off with damp ph indicator paper. leave the test-tube to cool. ..  ..  [3]   add the rest of mixture e to about 10  cm3  of distilled water in a boiling tube. stopper the boiling tube and shake the contents for about a minute. filter the contents of the boiling tube.   keep the residue and the \ufb01 ltrate for the  following tests. tests on the \ufb01 ltrate (c) (i)   to about 1  cm3 of the \ufb01 ltrate, add about  1 cm3 of aqueous sodium hydroxide.    gently heat the mixture. test the gas  given off with damp ph indicator paper.  (ii)  add about 1  cm3 of silver nitrate  solution to the second portion of the \ufb01 ltrate followed by about 1  cm3 of dilute  nitric acid. ..   [1]  ..   [1]",
            "6": "6 0620/52/m/j/14 \u00a9 ucles 2014tests observations tests on the residue (d)  using a spatula, transfer a little of the  residue from the \ufb01 lter paper to a test-tube.  using a teat pipette, add about 2  cm3 of  dilute hydrochloric acid to the residue. test the gas given off.   add an equal volume of distilled water to  the solution in the test-tube.   shake the contents and divide into two  portions. ..  ..  [2] (e) (i)   add several drops of aqueous sodium  hydroxide to the \ufb01 rst portion of the  solution. now add excess aqueous sodium hydroxide.  (ii)  add several drops of aqueous  ammonia to the second portion. now add excess aqueous ammonia. ..   [3]  ..   [2]  (f)  explain your observations in test (b).   ... .   ... ...  [2]  (g)  what conclusions can you draw about solid f?   ... .   ... ...  [2]  (h)  what conclusions can you draw about solid g?   ... .   ... ...  [2] [total: 19]",
            "7": "7 0620/52/m/j/14blank page \u00a9 ucles 2014",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/52/m/j/14notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2014"
        },
        "0620_s14_qp_53.pdf": {
            "1": "this document consists of 7 printed pages and 1 blank page. [turn overib14 06_0620_53/3rp \u00a9 ucles 2014 *7887217677* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test may/june 2014  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/53/m/j/14 \u00a9 ucles 20141  you are going to investigate what happens when two different solids, m and n, dissolve in water.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out three experiments.  (a) experiment 1   use a measuring cylinder to pour 25  cm3 of distilled water into the polystyrene cup. support the  cup by putting it into the 250  cm3 beaker. measure the temperature of the water and record it  in the table below.   add all of solid m to the water, start the timer and stir the solution with the thermometer.   measure the temperature of the solution every 30 seconds for three minutes. record your  results in the table. at the end of the experiment, pour about 4  cm3 of the solution into a test- tube for experiment 3. time  / s 0 30 60 90 120 150 180 temperature of solution  / \u00b0c [2]  (b) experiment 2   empty the polystyrene cup and rinse it with water.   use a measuring cylinder to pour 25  cm3 of distilled water into the polystyrene cup.   measure the temperature of the water and record it in the table below.   add all of solid n to the water, start the timer and stir the solution with the thermometer.   measure the temperature of the solution every 30 seconds for three minutes. record your  results in the table. time  / s 0 30 60 90 120 150 180 temperature of solution  / \u00b0c [2]  (c) experiment 3   to about 4  cm3 of the solution from experiment 1, add about 1  cm3 of dilute sulfuric acid.   record your observation.   ... ...  [1]",
            "3": "3 0620/53/m/j/14 \u00a9 ucles 2014 [turn over (d)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label your graphs. 60 5040302010 0 time  / stemperature of solution  / \u00b0c 0 30 60 90 120 150 180 [6]  (e) (i)   from your graph , deduce the temperature of the solution in experiment 1 after 45 seconds.   show clearly on the graph  how you worked out your answer.  ..  \u00b0c [2]  (ii)  from your graph , deduce how long it takes for the initial temperature of the solution in  experiment 2 to change by 2  \u00b0c.   show clearly on the graph  how you worked out your answer.  ..  s [2]",
            "4": "4 0620/53/m/j/14 \u00a9 ucles 2014 (f)  from your results in experiment 2, what type of chemical process occurs when substance n  dissolves in water?   ... ...  [1]  (g)  what conclusion can you draw from experiment 3?   ... ...  [1]  (h)  suggest the effect on the results if experiment 1 was repeated using 50  cm3 of distilled water.   ... .   ... ...  [2]  (i)  predict the temperature of the solution in experiment 2 after one hour. explain your answer.   ... .   ... ...  [2]  (j)  when carrying out the experiments, what would be the advantage of taking the temperature  readings every 10 seconds?   ... .   ... ...  [1] [total: 22]",
            "5": "5 0620/53/m/j/14 \u00a9 ucles 2014 [turn over2  you are provided with two solids p and q.   carry out the following tests on p and q, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solid p use a spatula to divide solid p into two separate  boiling tubes. (a)  describe the appearance of solid p.  .. (b) (i)   add about 3  cm3 of dilute sulfuric acid  to the \ufb01 rst boiling tube of p and warm  the mixture for two minutes.    allow the mixture to settle.     decant the solution into two equal  portions in separate test-tubes. add an equal volume of distilled water to each test-tube. carry out the following tests.  (ii)  add several drops of aqueous sodium  hydroxide to the \ufb01 rst portion of the  solution and shake the test-tube.    now add excess sodium hydroxide to  the test-tube.  (iii)  add aqueous potassium iodide to the  second portion of the solution, shake and leave to stand for ten minutes.  [1]  ..   [2]  ..   [2] (c)  to the second boiling tube of p add about  2  cm3 of dilute hydrochloric acid and warm  the mixture for two minutes. allow the mixture to settle.   decant off 1  cm3 of the liquid into a test-tube. add aqueous ammonia to the solution until no further change is seen.  [1]  ..  ..  [3]",
            "6": "6 0620/53/m/j/14 \u00a9 ucles 2014tests observations tests on solid q (d)  describe the appearance of solid q.   [1] (e) (i)   add about 3  cm3 of dilute sulfuric acid  to solid q in the boiling tube and warm  the mixture for two minutes.    allow the mixture to settle.    decant the solution into two equal  portions in separate test-tubes.  (ii)  add aqueous sodium hydroxide to the  \ufb01 rst portion until there is no further  change.  (iii)  add aqueous ammonia to the second  portion until there is no further change. ..   [2]  ..   [1]  ..   [2]  (f)  identify solid p.   ... ...  [2]  (g)  draw a conclusion about q.   ... ...  [1] [total: 18]",
            "7": "7 0620/53/m/j/14blank page \u00a9 ucles 2014",
            "8": "8 permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 0620/53/m/j/14notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint \u00a9 ucles 2014"
        },
        "0620_s14_qp_61.pdf": {
            "1": "this document consists of 10 printed pages and 2 blank pages. [turn overib14 06_0620_61/2rp \u00a9 ucles 2014 \uf02a\uf035\uf037\uf035\uf035\uf037\uf031\uf037\uf036\uf036\uf037\uf02a read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical may/june 2014  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/61/m/j/14 \u00a9 ucles 20141  a student separated a mixture of two alcohols, ethanol (boiling point 78 \uf0b0c) and butanol (boiling point 118 \uf0b0c).   the apparatus used is shown below. heatmixture of alcohols  (a)  complete the boxes to identify the pieces of apparatus labelled. [2]  (b)  label the arrows. [1]  (c)  state the name of this separation process.   ... ...  [2]  (d) (i)   which liquid is \ufb01 rst to collect in the beaker?   . ..  [1]  (ii)  how would the student know when all of this liquid had collected?   .    . ..  [1]",
            "3": "3 0620/61/m/j/14 \u00a9 ucles 2014 [turn over (e)  identify and explain a possible hazard in this experiment.   ... .   ... ...  [2] [total: 9] 2  the following paragraph was taken from a student\u2019s notebook. preparation of lead chloride 10 cm3 of aqueous lead nitrate was placed in a beaker and 10  cm3 of aqueous potassium  chloride added. lead chloride, a white solid, was formed. the solid was separated from the mixture.water was then added to the solid and the mixture boiled. a clear liquid was formed. on cooling, white crystals were deposited.  (a)  what type of chemical reaction resulted in the formation of the lead chloride?   ... ...  [1]  (b)  what is the solubility of lead chloride in  (i)  cold water,  ..   (ii)  hot water?  ... ..  [2]  (c)  what method should be used to separate the crystals from the mixture?   ... ...  [1] [total: 4]",
            "4": "4 0620/61/m/j/14 \u00a9 ucles 20143  a student investigated the reaction of zinc powder with dilute hydrochloric acid using the apparatus  below. hydrochloric acid zincgas syringe   the same mass of zinc was added to different volumes of hydrochloric acid at room temperature,  20 \uf0b0c. the total volume of hydrogen gas given off in each experiment was measured.  (a)  use the gas syringe diagrams to record the volumes of hydrogen gas in the table. volume of hydrochloric acid / cm3gas syringe diagramvolume of hydrogen gas / cm3 001 02 03 0 50 60 40 501 02 03 0 50 60 40 1001 02 03 0 50 60 40 1501 02 03 0 50 60 40 2001 02 03 0 50 60 40 3001 02 03 0 50 60 40 4001 02 03 0 50 60 40 [3]",
            "5": "5 0620/61/m/j/14 \u00a9 ucles 2014 [turn over (b)  on the grid, plot the points and draw a smooth line graph. 60 40 20 0 01 0 2 0 volume of hydrochloric acid  / cm330 40volume of hydrogengas  / cm3 [4]  (c) (i)   which point is inaccurate?   . ..  [1]  (ii)  suggest a possible reason for this inaccurate measurement.   . ..  [1]  (iii)  use your graph  to work out the volume that would be expected to be formed.   show clearly on the grid  how you got your answer.   . ..  [2]  (d)  explain why the volume of hydrogen gas does not increase after 30 cm3 of hydrochloric acid.   ... .   ... ...  [2]  (e)  sketch on the grid the graph you would expect if the experiments were repeated using the  same mass of zinc granules. [2] [total: 15]",
            "6": "6 0620/61/m/j/14 \u00a9 ucles 20144  a student investigated the reaction between dilute hydrochloric acid and an aqueous alkaline  solution r, containing two different substances, s and t.   three experiments were carried out.   experiment 1   using a measuring cylinder, 25 cm3 of solution r was poured into a conical \ufb02 ask and \ufb01 ve drops of  phenolphthalein were added to the \ufb02 ask.   a burette was \ufb01 lled with hydrochloric acid up to the 0.0 cm3 mark. hydrochloric acid was added to  the solution r and the \ufb02 ask shaken. addition of hydrochloric acid was continued until the colour just  disappeared.   the mixture in the \ufb02 ask was kept for experiment 2.  (a)  use the burette diagram to record the \ufb01 nal volume in the table of results and complete the  table. 16 1718 final burette reading burette readings \ufb01 nal volume / cm3 initial volume / cm3 difference / cm3 [3]   experiment 2   five drops of methyl orange indicator were added to the mixture in the \ufb02 ask from experiment 1. the  mixture turned yellow. the initial volume reading of the burette was the same as the \ufb01 nal reading  in experiment 1. hydrochloric acid was added from the burette to the mixture in the \ufb02 ask and the  mixture shaken.   the volume of hydrochloric acid added was recorded when the indicator just changed colour.  (b)  use the burette diagram to record the \ufb01 nal volume in the table of results and complete the  table. 24 2526 final burette reading burette readings \ufb01 nal volume / cm3 initial volume / cm3 difference / cm3 [3]",
            "7": "7 0620/61/m/j/14 \u00a9 ucles 2014 [turn over (c)   experiment 3   hydrochloric acid was added to about 5 cm3 of solution r in a test-tube.  rapid effervescence was observed. (d)  when phenolphthalein indicator was used in experiment 1 the colour changed   from pink to  . .  [1]  (e)  in a similar experiment, methyl orange indicator was used in experiment 1 followed by  phenolphthalein in experiment 2.   suggest why this experiment would not work.   ... .   ... ...  [1]  (f)  what conclusion can you draw from experiment 3?   ... ...  [1]  (g)  the volume of hydrochloric acid added in experiment 1 reacted with all of substance s and half  of substance t.   the volume of hydrochloric acid in experiment 2 reacted with half of substance t.  (i)  work out the volume of hydrochloric acid which reacted with substance s.   . ..  [2]  (ii)  work out the volume of hydrochloric acid which reacted with substance t.   . ..  [1]  (iii)  compare the volumes of hydrochloric acid which reacted with substances s and t.   . ..  [1]  (h) (i)   the experiments were repeated using 100 cm 3 of solution r.   predict the volume of hydrochloric acid which would be added in experiments 1 and 2.  explain your answer.  experiment 1   ..  experiment 2   ..  explanation  . ..  [3]  (ii)  suggest a practical problem that would occur when carrying out these repeat experiments  and how you could solve this problem.   .    . ..  [2] [total: 18]",
            "8": "8 0620/61/m/j/14 \u00a9 ucles 20145  a solid u was analysed. u was a soluble metal sulfate.   the tests on u, and some of the observations are in the following table.   complete the observations. tests observations tests on solid u (a)  appearance of solid u. pink crystals (b)  solid u was heated gently and then  strongly in a test-tube. condensation droplets formed on the sides of the test-tube (c)  solid u was added to distilled  water in a test-tube and shaken until dissolved.   the solution was divided into  three equal portions in separate test-tubes and the following tests carried out.   several drops of aqueous sodium  hydroxide were added to the \ufb01 rst  portion of the solution and thetest-tube shaken.   then hydrogen peroxide solution  was added to the mixture and the gas given off tested.pale brown precipitate effervescence glowing splint relit (d)  dilute nitric acid was added to  the second portion of the solution followed by barium nitrate solution. ..   [2] (e)  dilute nitric acid was added to the  third portion of the solution followed by silver nitrate solution. ..   [1]",
            "9": "9 0620/61/m/j/14 \u00a9 ucles 2014 [turn over (f)   what does test (e) tell you about solid u?   ... ...  [1]  (g)  name the gas given off in test (c).   ... ...  [1]  (h)  what conclusions can you draw about solid u?   ... .   ... ...  [2] [total: 7]",
            "10": "10 0620/61/m/j/14 \u00a9 ucles 20146  nuts contain oil. nuts can be burned to produce energy. the apparatus shown can be used to  compare the energy produced by burning different nuts. thermometer water nut   plan an investigation to show which of three different types of nut produce the most energy. you are  provided with peanuts, brazil nuts and hazelnuts.   ...    ...    ...    ...    ...    ...    ...    ...    ... ..  [7] [total: 7]",
            "11": "11 0620/61/m/j/14 \u00a9 ucles 2014blank page",
            "12": "12 0620/61/m/j/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.blank page"
        },
        "0620_s14_qp_62.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib14 06_0620_62/4rp \u00a9 ucles 2014 *9115508770* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical may/june 2014  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/62/m/j/14 \u00a9 ucles 20141  a student investigated the effect of using electricity to break down a solution of concentrated  hydrochloric acid using the apparatus shown. concentrated hydrochloric acidcarbon rods   during the experiment, bubbles were observed at both carbon rods.  (a)  complete the box to identify the piece of apparatus used. [1]  (b) (i)   name the process that occurs when electricity is passed through concentrated hydrochloric  acid.   . ..  [1]  (ii)  what is the purpose of the carbon rods?   . ..  [1]  (c)   name one of the gases formed and state a test for this gas.  name  ... ...  test   .  result  .. ..  [2]  (d)  draw a diagram of different apparatus that could be used to collect the gases formed at the carbon rods. [2] [total: 7]",
            "3": "3 0620/62/m/j/14 \u00a9 ucles 2014 [turn over2  the graph shows the change in the ph when aqueous potassium hydroxide is added to 25.0 cm3 of  dilute nitric acid to form a solution of potassium nitrate. a ph meter was used. 14 1210 86420 0 5 10 15 volume of potassium hydroxide  / cm320 25phpoint x  (a)  name a suitable piece of apparatus to measure 25.0 cm3 of dilute nitric acid.   ... ...  [1]  (b)  what could be used instead of a ph meter in this experiment?   ... ...  [1]  (c)  describe how the ph of the mixture changes as the potassium hydroxide is added.   ... .   ... .   ... ...  [2]",
            "4": "4 0620/62/m/j/14 \u00a9 ucles 2014 (d) (i)  what has happened at point x?   . ..  [1]  (ii)  what volume of aqueous potassium hydroxide had been added to the mixture at point x?   . ..  [2]  (iii)  what conclusion can you draw about the concentrations of the dilute nitric acid and the  aqueous potassium hydroxide? explain your answer.   .    .    . ..  [3]  (e)  suggest the effect of heating the solution of potassium nitrate to boiling point and then heating for a further ten minutes.   ... .   ... ...  [2] [total: 12]",
            "5": "5 0620/62/m/j/14 \u00a9 ucles 2014 [turn over3  long-chain alkanes can be cracked to form short-chain alkenes. the apparatus below was used to  produce ethene. waterethenealuminium oxideliquid alkane on mineral fibre  (a)  which piece of apparatus is missing from the diagram?   ... ...  [1]  (b)  suggest why the \ufb01 rst tube of gas that is collected should be discarded.   ... .   ... ...  [2]  (c)  what is the function of the aluminium oxide?   ... ...  [1]  (d)  describe a chemical test to distinguish an alkane from an alkene.   ... .   ... ...  [2] [total: 6]",
            "6": "6 0620/62/m/j/14 \u00a9 ucles 20144  a student investigated the temperature rises produced when different lengths of magnesium ribbon  reacted with excess dilute sulfuric acid.   five experiments were carried out.  (a) experiment 1   using a measuring cylinder, 20 cm3 of dilute sulfuric acid was added to a beaker. the initial  temperature of the solution was measured. a 2 cm length of magnesium ribbon was added to the acid in the beaker and the mixture stirred with a thermometer. the highest temperature reached was measured.   use the thermometer diagrams to record the initial and highest temperatures in the table on page 7. 40 35 3030 25 20 initial temperature highest temperature  (b) experiment 2   experiment 1 was repeated, using a 3 cm length of magnesium ribbon. use the thermometer  diagrams to record the initial and highest temperatures in the table.",
            "7": "7 0620/62/m/j/14 \u00a9 ucles 2014 [turn over (c) experiments 3, 4 and 5   experiment 1 was repeated, using a 4 cm length, a 6 cm length and a 7 cm length of magnesium  ribbon. use the thermometer diagrams to record the temperatures in the table.   complete the table of results. 1 40 35 30230 25 20 50 45 40335 30 25 50 45 40430 25 20 55 50 45535 30 25experimentinitial temperature / \u00b0cthermometer diagramthermometer diagramhighest temperature / \u00b0cchange in temperature / \u00b0c [5]",
            "8": "8 0620/62/m/j/14 \u00a9 ucles 2014 (d)   plot the results on the grid below. draw a best \ufb01 t straight line graph. 30 20 10 0 0123 length of magnesium ribbon  / cm45 6 7 8change in temperature / \u00b0c [4]  (e)  from your graph , deduce the temperature change expected if experiment 1 was repeated  using an 8 cm length of magnesium ribbon.   show clearly on the grid  how you worked out your answer.   ... ...  [3]  (f)  give one expected observation, other than temperature rise, when magnesium reacts with  dilute sulfuric acid.   ... ...  [1]",
            "9": "9 0620/62/m/j/14 \u00a9 ucles 2014 [turn over (g) (i)   which experiment gave the greatest change in temperature?   . ..  [1]  (ii)  suggest why the change in temperature was greatest in this experiment.   .    . ..  [1]  (h)  what difference would be observed if experiment 1 was repeated using an equal mass of  magnesium powder? explain your answer.   ... .   ... ...  [2]  (i)  suggest the temperature change expected if experiment 1 was repeated using 40 cm3 of dilute  sulfuric acid.   ... ...  [1]  (j)  draw a diagram of apparatus you could use to collect and measure the volume of gas given off in the reaction. [2]  (k)  state one source of error in the results obtained in the experiments. give one improvement to  reduce this source of error.  error  ...   improvement  . ...  [2] [total: 22]",
            "10": "10 0620/62/m/j/14 \u00a9 ucles 20145  a mixture e was analysed. e consisted of two solids, f and g. solid f was ammonium chloride  which is water-soluble and solid g was insoluble.   the tests on e and some of the observations are in the following table.   complete the observations in the table.  tests observations tests on mixture e (a)  appearance of mixture e. white solid (b)  mixture e was heated gently then  strongly.   the gas was tested with damp ph  indicator paper and the test-tube left to cool. ..   [1] mixture e was added to distilled water in  a boiling tube and shaken. the contents  of the boiling tube were \ufb01 ltered. tests on the \ufb01 ltrate (c) (i)  aqueous sodium hydroxide  was added to the \ufb01 ltrate.    the mixture was heated. the gas given off was tested with damp ph indicator paper.  (ii)  silver nitrate solution was added to the \ufb01 ltrate followed  by about 1 cm 3 of dilute nitric  acid. ..   [2] ..   [2]",
            "11": "11 0620/62/m/j/14 \u00a9 ucles 2014 [turn overtests observations tests on the residue (d)  the residue was transferred from  the \ufb01 lter paper into a test-tube.  dilute hydrochloric acid was added to the residue.   the gas given off was tested.rapid effervescence limewater turned milky the solution in the test-tube was divided  into two portions. (e) (i)  several drops of aqueous  sodium hydroxide were added to the \ufb01 rst portion of the  solution.    excess aqueous sodium hydroxide was then added to the mixture.  (ii)  several drops of aqueous ammonia were added to the second portion of the solution.     excess aqueous ammonia was then added to the mixture.white precipitate precipitate dissolved white precipitate precipitate dissolved  (f)  what conclusions can you draw about solid g?   ... .   ... ...  [2] [total: 7]",
            "12": "12 0620/62/m/j/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.6  cerussite is an ore of lead. cerussite is lead carbonate, pbco3.   in the reactivity series, lead is between iron and copper.   plan an investigation to obtain a sample of lead from a large lump of cerussite.   you are provided with common laboratory apparatus and chemicals.   ...    ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 6]"
        },
        "0620_s14_qp_63.pdf": {
            "1": "this document consists of 11 printed pages and 1 blank page. [turn overib14 06_0620_63/2rp \u00a9 ucles 2014 \uf02a\uf033\uf035\uf032\uf038\uf035\uf037\uf034\uf037\uf033\uf035\uf02a read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical may/june 2014  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/63/m/j/14 \u00a9 ucles 20141  steam was passed over heated magnesium ribbon using the apparatus below. ceramic woolmagnesium ribbon y  (a) (i)   complete the box to show the substance absorbed by the ceramic wool. [1]  (ii)  indicate on the diagram, with two arrows, where the heat is applied. [1]  (b) (i)  describe the change in the appearance of the magnesium.   . ..  [2]  (ii)  predict the effect of adding water and a few drops of universal indicator to the solid product  of the reaction.   .    . ..  [2]  (c)   suggest the effect of a lighted splint at point y. explain your suggestion.   ... .   ... ...  [2] [total: 8]",
            "3": "3 0620/63/m/j/14 \u00a9 ucles 2014 [turn over2  a student carried out three experiments to investigate the rate of reaction between dilute hydrochloric acid and zinc powder.  experiment 1   50 cm3 of dilute hydrochloric acid were reacted with excess zinc powder. the volume of gas  produced was measured every minute for ten minutes.  experiment 2   experiment 1 was then repeated using 100 cm3 of the dilute hydrochloric acid.   the results for these two experiments are shown below. 60 5040302010 0 012345 time  / mins6789 1 0volume of gas  / cm3  (a)  label the two lines to identify each experiment. [1]",
            "4": "4 0620/63/m/j/14 \u00a9 ucles 2014 experiment 3   experiment 1 was repeated using 50 cm3 of dilute hydrochloric acid which was half as concentrated  as in experiment 1.  (b) (i)   how could the student prepare a solution of dilute hydrochloric acid which was half as  concentrated as the acid in experiment 1?   .    . ..  [2]  (ii)  sketch, on the grid on page 3, the result that would be expected in experiment 3. [2]  (c)  complete the diagram to show how the gas could be collected and measured. [2]  (d)  explain how the rate of reaction could be increased in experiment 3 without changing the  concentration of the dilute hydrochloric acid.   ... .   ... .   ... ...  [3] [total: 10]",
            "5": "5 0620/63/m/j/14 \u00a9 ucles 2014 [turn over3  a student carried out an investigation to coat a copper key with nickel. he followed these instructions.  1  rub the copper key with sandpaper.  2  set up the circuit as shown. copper key nickel electrode electrolyte  3  switch on the circuit for ten minutes.  4  remove the key, wash it and dry.  (a)  name the process used to coat the copper key with nickel.   ... ...  [1]  (b)  why was the key rubbed with sandpaper?   ... .   ... ...  [2]  (c)  name a possible electrolyte that could be used.   ... ...  [2]  (d)  give one expected observation during the ten minutes that the circuit was switched on.   ... ...  [1]  (e)   describe how the key would be washed and dried.   ... .   ... ...  [1] [total: 7]",
            "6": "6 0620/63/m/j/14 \u00a9 ucles 20144  a student investigated what happened when two different solids, m and n, dissolved in water.   three experiments were carried out.  (a) experiment 1   using a measuring cylinder, 25 cm3 of distilled water were poured into a polystyrene cup. the  temperature of the water was measured. solid m was added to the water, the timer started and  the mixture stirred with a thermometer. the temperature of the solution was measured every 30 seconds for three minutes.    use the thermometer diagrams to record the results in the table.   a little of the solution was poured into a test-tube for experiment 3. 30 25 20time  / s temperature / \u00b0cthermometer diagram0 40 35 3030 40 35 3060 40 35 3090 40 35 30120 40 35 30150 40 35 30180 [2]  (b)  experiment 2   experiment 1 was repeated using solid n.   the temperature of the solution was measured every 30 seconds for three minutes.   use the thermometer diagrams to record the results in the table. 30 25 20time  / s temperature / \u00b0cthermometer diagram0 20 15 1030 20 15 1060 20 15 1090 20 15 10120 20 15 10150 20 15 10180 [2]  (c)  experiment 3   dilute sulfuric acid was added to the solution from experiment 1.   rapid effervescence was observed.",
            "7": "7 0620/63/m/j/14 \u00a9 ucles 2014 [turn over (d)   plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label your graphs. 40 30 20 10 0 03 0 6 0 9 0 time  / s120 150 180temperature / \u00b0c [6]  (e) (i)   from your graph , deduce the temperature of the solution in experiment 1 after 45 seconds.   show clearly on the graph  how you worked out your answer.  . \uf0b0c [2]  (ii)  from your graph , deduce how long it takes for the initial temperature of the solution in  experiment 2 to change by 2 \uf0b0c.   show clearly on the graph  how you worked out your answer.  . s [2]",
            "8": "8 0620/63/m/j/14 \u00a9 ucles 2014 (f)  from the results in experiment 2, what type of chemical process occurs when substance n  dissolves in water?   . ..  [1]  (g)  what conclusion can you draw from experiment 3?   . ..  [1]  (h)  suggest the effect on the results if experiment 1 was repeated using 50 cm3 of water.   ... .   ... ...  [2]  (i)  predict the temperature of the solution in experiment 2 after 1 hour. explain your answer.   ... .   ... ...  [2]  (j)  when carrying out the experiments, what would be the advantage of taking the temperature  readings every 10 seconds?   ... .   ... ...  [1] [total: 21]",
            "9": "9 0620/63/m/j/14 \u00a9 ucles 2014 [turn over5  two solids, p and q, were analysed. p was a metal compound and q was calcium iodide.   tests were carried out on p and q and some of the observations are in the following table.   complete the observations for solid q. tests observations tests on solid p (a)  appearance of solid p. black solid (b) (i)  dilute sulfuric acid was added to  solid p and the mixture warmed.    the solution was divided into  two equal portions in test-tubes.    the following tests were carried  out.  (ii)  drops of aqueous sodium  hydroxide were added to the \ufb01 rst portion of the solution.     excess sodium hydroxide was  then added to the mixture in the test-tube.  (iii)  aqueous ammonia was added  to the second portion of the solution until no further change was seen.the solid reacted and a blue solution was formed blue precipitate formed blue precipitate insoluble blue precipitate formed which dissolved to form a deep blue solution",
            "10": "10 0620/63/m/j/14 \u00a9 ucles 2014tests observations tests on solid q (c)  distilled water was added to solid q  and the mixture shaken to dissolve solid q.   the solution was divided into three  equal portions in separate test-tubes.  (i)  aqueous sodium hydroxide was  added to the \ufb01 rst portion until no  further change was seen.  (ii)  aqueous ammonia was added  to the second portion until no further change was seen.  (iii)  dilute nitric acid and aqueous  silver nitrate were added to the third portion... .   [3] .. .   [1] .   [1]  (d)  identify solid p.   ... ...  [2] [total: 7]",
            "11": "11 0620/63/m/j/14 \u00a9 ucles 2014 [turn over6  vinegar contains ethanoic acid. different brands of vinegar contain different concentrations of  ethanoic acid. the concentration of ethanoic acid in the vinegar can be determined by reaction with aqueous sodium hydroxide.   plan an experiment to show which of two different brands of colourless vinegar, c and d, contain  the highest concentration of ethanoic acid.   you are provided with common laboratory apparatus.   you may use the space below to draw a diagram.   ...    ...    ...    ...    ...    ...    ...    ... ..  [7] [total: 7]",
            "12": "12 0620/63/m/j/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.blank page"
        },
        "0620_w14_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 13 printed pages and 3 blank pages.  ib14 11_0620_11/2rp  \u00a9 ucles 2014 [turn over       *4174905704* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  october/november 2014       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2014 0620/11/o/n/14  1 which statement is an example of diffusion?  a a kitchen towel soaks up some spilt milk.  b ice cream melts in a warm room.  c pollen from flowers is blown by the wind.  d the smell of cooking spreads through a house.      2 a mixture is separated using the apparatus shown.    mixture funnel filter paper     what is the mixture?  a aqueous copper chloride and copper  b aqueous copper chloride and sodium chloride  c ethane and methane  d ethanol and water     3 ethanol is made by fermentation.    how is ethanol obtained from the fermentation mixture?  a chromatography  b crystallisation  c electrolysis  d fractional distillation      4 what is different for isotopes of the same element?  a nucleon number  b number of electron shells  c number of electrons in the outer shell  d proton number   ",
            "3": "3  \u00a9 ucles 2014 0620/11/o/n/14 [turn over  5 which element has the atomic structure shown?    ekey electron nucleus16nnneutron eeeee ee ee ee ee ee     a a l b  p c  s d  si      6 slate has a layered structure and can easily be split into thin sheets.    which diagram shows a structure most like that of slate?    b a cd       7 sodium chloride is an ionic solid.    which statement is not correct?  a ions are formed when atoms lose or gain electrons.  b ions in sodium chloride are strongly held together.  c ions with the same charge attract each other.  d sodium chloride solution can conduct electricity.     ",
            "4": "4  \u00a9 ucles 2014 0620/11/o/n/14  8 caesium chloride and rubidium bromide are halide compounds of group i elements.    caesium chloride has the formula \u2026\u20261\u2026\u2026, a relative formula mass \u2026\u20262\u2026\u2026 that of rubidium  bromide and bonds that are \u2026\u20263\u2026\u2026 .    which words correctly complete gaps 1, 2 and 3?     1 2 3  a cac l different from ionic  b cac l the same as covalent  c csc l different from ionic  d csc l the same as covalent    9 how many atoms of hydrogen are there in a molecule of ethanol, c 2h5oh?  a 1 b 2 c 5 d 6    10 iron forms an oxide with the formula fe 2o3.    what is the relative formula mass of this compound?  a 76 b 100 c 136 d 160      11 which metal could not be used for electroplating by using an aqueous solution?  a chromium  b copper  c silver  d sodium    12 which products are formed at the electrodes when a concentrated solution of sodium chloride is  electrolysed?     cathode (\u2013) anode (+)  a hydrogen chlorine  b hydrogen oxygen  c sodium chlorine  d sodium oxygen    ",
            "5": "5  \u00a9 ucles 2014 0620/11/o/n/14 [turn over  13 which statements about exothermic and endothermic reactions are correct?    1 during an exothermic reaction, heat is given out.  2 the temperature of an endothermic reaction goes up because heat is taken in. 3 burning methane in the air is an exothermic reaction.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      14 a power station was designed to burn gaseous fuels only.    which two substances could be used?  a carbon dioxide and hydrogen  b carbon dioxide and  235u  c hydrogen and methane  d methane and 235u     15 the rate of a reaction depends on temperature, concentration, particle size and catalysts.    which statement is not correct?  a catalysts can be used to increase the rate of reaction.  b higher concentration decreases the rate of reaction.  c higher temperature increases the rate of reaction.  d larger particle size decreases the rate of reaction.      16 the diagram shows the change from an anhydrous salt to its hydrated form.    hydrated salt anhydrous saltforward reverse    which statement is correct?    a forward reaction requires heat and water  b forward reaction requires water only  c reverse reaction requires heat and water  d reverse reaction requires water only   ",
            "6": "6  \u00a9 ucles 2014 0620/11/o/n/14  17 the equations for two reactions p and q are given.    p 2nano 2  +  o 2  \u2192  2nano 3  q 2hgo  \u2192  2hg  +  o 2    in which of these reactions does oxidation of the underlined substance occur?     p q  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     18 which changes decrease the rate of reaction between magnesium and air?    1 heating the magnesium to a higher temperature  2 using a higher proportion of oxygen in the air  3 using magnesium ribbon instead of powdered magnesium    a 1, 2 and 3 b 1 only c 2 only d 3 only     19 which substance is the most acidic?     substance ph  a calcium hydroxide 12  b lemon juice 4  c milk 6  d washing up liquid 8    20 the positions of elements w, x, y and z in the periodic table are shown.    w xy z    which elements form basic oxides?  a w, x and y b w and x only c y only d z only     ",
            "7": "7  \u00a9 ucles 2014 0620/11/o/n/14 [turn over  21 how many different salts could be made from a supply of dilute sulfuric acid, dilute hydrochloric  acid, copper, magnesium oxide and zinc carbonate?  a 3 b 4 c 5 d 6      22 the graph shows how the ph of soil in a field changes over time.    at which point was the soil neutral?    11 9 753ph of soil timea b cd      23 elements in group i of the periodic table react with water.    which row describes the products made in t he reaction and the trend in reactivity of the  elements?     products trend in reactivity  a metal hydroxide and hydrogen less reactive down the group  b metal hydroxide and hydrogen more reactive down the group  c metal oxide and hydrogen less reactive down the group  d metal oxide and hydrogen more reactive down the group    ",
            "8": "8  \u00a9 ucles 2014 0620/11/o/n/14  24 an element x has the two properties listed.    1 it acts as a catalyst.  2 it forms colourless ions.    which of these properties suggest that x is a transition element?     property 1 property 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      25 an inert gas x is used to fill weather balloons.    which descriptions of x are correct?     number of outer  electrons in atoms of x structure of gas x  a 2 single atoms  b 2 diatomic molecules  c 8 single atoms  d 8 diatomic molecules      26 the table shows the reactions of four different metals with water.    metal reaction  w reacts vigorously with cold water  x no reaction with water  y reacts very slowly with water, more vigorously with steam  z reacts violently with cold water    what is the correct order of reactivity, from most reactive to least reactive?  a w \u2192 x \u2192 y \u2192 z  b w \u2192 z \u2192 y \u2192 x  c z \u2192 w \u2192 x \u2192 y  d z \u2192 w \u2192 y \u2192 x     ",
            "9": "9  \u00a9 ucles 2014 0620/11/o/n/14 [turn over  27 which information about an element can be used to predict its chemical properties?  a boiling point  b density  c melting point  d position in the periodic table      28 aluminium is the most common metal in the earth\u2019s crust.    which is not a property of aluminium?    a low density  b resistance to corrosion  c good conductor of electricity  d poor conductor of heat    29 the oxide of element x is reduced by heating with carbon.    element x does not react with cold water, steam or dilute hydrochloric acid.    what is x?  a copper  b iron  c magnesium  d zinc      30 which object is least  likely to contain aluminium?  a a bicycle frame  b a hammer  c a saucepan  d an aeroplane body      31 which reaction involves oxidation?  a heating hydrated copper( ii) sulfate in the air  b polymerisation of ethene  c rusting of iron  d thermal decomposition of calcium carbonate     ",
            "10": "10  \u00a9 ucles 2014 0620/11/o/n/14  32 which method can be used to obtain ammonia from ammonium sulfate?  a heat it with an acid.  b heat it with an alkali.  c heat it with an oxidising agent.  d heat it with a reducing agent.      33 which method of purification would produce water most  suitable for drinking?    muddy river waterpurified waterfiltration filtration filtrationsettlementchlorination chlorinationa b cd       34 which statement about methane is not correct?  a it is a liquid produced by distilling petroleum.  b it is produced as vegetation decomposes.  c it is produced by animals, such as cows.  d it is used as a fuel.    35 which is an air pollutant that affects a part of the body other than the lungs and blood system?  a lead compounds  b nitrogen  c oxides of nitrogen  d sulfur dioxide    ",
            "11": "11  \u00a9 ucles 2014 0620/11/o/n/14 [turn over  36 increasing the number of atoms in one molecule of a hydrocarbon increases the amount of  energy released when it burns.    what is the correct order?     less energy  released  more energy  released  a ethene ethane methane  b ethene methane ethane  c methane ethane ethene  d methane ethene ethane      37 which molecular structure shows hexene?    h ch hhhhhhh h hh c c c c ca h ch hhhhhh h h hoho c c c ccdh ch hhhhhhh c c chh chh h cb h ch hhhhhhh c c chh chh o h cc      38 the diagram shows three repeat units in the structure of an addition polymer.    ch hccl hcchhchclhhccl h     which alkene monomer is used to make this polymer?    cc hh clh cc hcl clh hhcl ch hc hhhcl cl chchabcd    ",
            "12": "12  \u00a9 ucles 2014 0620/11/o/n/14  39 which statement about alkenes is not correct?  a the functional group is c=c.  b the structural difference between one member and the next is \u2013  ch 3 \u2013.  c they form a homologous series.  d they turn aqueous bromine from brown to colourless.      40 ethanol can be manufactured from substance x.    substance x  +  steam ethanolcatalyst     what is substance x?  a carbon dioxide  b ethene  c hydrogen  d oxygen     ",
            "13": "13  \u00a9 ucles 2014 0620/11/o/n/14  blank page ",
            "14": "14  \u00a9 ucles 2014 0620/11/o/n/14  blank page ",
            "15": "15  \u00a9 ucles 2014 0620/11/o/n/14  blank page",
            "16": "16    permission to reproduce items where third -party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2014 0620/11/o/n/14   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w14_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 13 printed pages and 3 blank pages.  ib14 11_0620_12/fp  \u00a9 ucles 2014 [turn over       *7952590132* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  october/november 2014       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2014 0620/12/o/n/14  1 ethanol is made by fermentation.    how is ethanol obtained from the fermentation mixture?  a chromatography  b crystallisation  c electrolysis  d fractional distillation     2 which statement is an example of diffusion?  a a kitchen towel soaks up some spilt milk.  b ice cream melts in a warm room.  c pollen from flowers is blown by the wind.  d the smell of cooking spreads through a house.    3 a mixture is separated using the apparatus shown.    mixture funnel filter paper     what is the mixture?  a aqueous copper chloride and copper  b aqueous copper chloride and sodium chloride  c ethane and methane  d ethanol and water      4 what is different for isotopes of the same element?  a nucleon number  b number of electron shells  c number of electrons in the outer shell  d proton number   ",
            "3": "3  \u00a9 ucles 2014 0620/12/o/n/14 [turn over  5 slate has a layered structure and can easily be split into thin sheets.    which diagram shows a structure most like that of slate?    b a cd       6 sodium chloride is an ionic solid.    which statement is not correct?  a ions are formed when atoms lose or gain electrons.  b ions in sodium chloride are strongly held together.  c ions with the same charge attract each other.  d sodium chloride solution can conduct electricity.     7 caesium chloride and rubidium bromide are halide compounds of group i elements.    caesium chloride has the formula \u2026\u20261\u2026\u2026, a relative formula mass \u2026\u20262\u2026\u2026 that of rubidium bromide and bonds that are \u2026\u20263\u2026\u2026 .    which words correctly complete gaps 1, 2 and 3?     1 2 3  a cac l different from ionic  b cac l the same as covalent  c csc l different from ionic  d csc l the same as covalent    ",
            "4": "4  \u00a9 ucles 2014 0620/12/o/n/14  8 which element has the atomic structure shown?    ekey electron nucleus16nnneutron eeeee ee ee ee ee ee     a a l b  p c  s d  si      9 how many atoms of hydrogen are there in a molecule of ethanol, c 2h5oh?  a 1 b 2 c 5 d 6      10 which metal could not be used for electroplating by using an aqueous solution?  a chromium  b copper  c silver  d sodium      11 which products are formed at the electrodes when a concentrated solution of sodium chloride is  electrolysed?     cathode (\u2013) anode (+)  a hydrogen chlorine  b hydrogen oxygen  c sodium chlorine  d sodium oxygen     12 iron forms an oxide with the formula fe 2o3.    what is the relative formula mass of this compound?  a 76 b 100 c 136 d 160     ",
            "5": "5  \u00a9 ucles 2014 0620/12/o/n/14 [turn over  13 which statements about exothermic and endothermic reactions are correct?    1 during an exothermic reaction, heat is given out.  2 the temperature of an endothermic reaction goes up because heat is taken in. 3 burning methane in the air is an exothermic reaction.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      14 a power station was designed to burn gaseous fuels only.    which two substances could be used?  a carbon dioxide and hydrogen  b carbon dioxide and  235u  c hydrogen and methane  d methane and 235u     15 the diagram shows the change from an anhydrous salt to its hydrated form.    hydrated salt anhydrous saltforward reverse    which statement is correct?    a forward reaction requires heat and water  b forward reaction requires water only  c reverse reaction requires heat and water  d reverse reaction requires water only    16 the rate of a reaction depends on temperature, concentration, particle size and catalysts.    which statement is not correct?  a catalysts can be used to increase the rate of reaction.  b higher concentration decreases the rate of reaction.  c higher temperature increases the rate of reaction.  d larger particle size decreases the rate of reaction.    ",
            "6": "6  \u00a9 ucles 2014 0620/12/o/n/14  17 which changes decrease the rate of reaction between magnesium and air?    1 heating the magnesium to a higher temperature  2 using a higher proportion of oxygen in the air 3 using magnesium ribbon instead of powdered magnesium    a 1, 2 and 3 b 1 only c 2 only d 3 only      18 which substance is the most acidic?     substance ph  a calcium hydroxide 12  b lemon juice 4  c milk 6  d washing up liquid 8     19 the equations for two reactions p and q are given.    p 2nano 2  +  o 2  \u2192  2nano 3  q 2hgo  \u2192  2hg  +  o 2    in which of these reactions does oxidation of the underlined substance occur?     p q  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    20 the positions of elements w, x, y and z in the periodic table are shown.    w xy z    which elements form basic oxides?  a w, x and y b w and x only c y only d z only     ",
            "7": "7  \u00a9 ucles 2014 0620/12/o/n/14 [turn over  21 how many different salts could be made from a supply of dilute sulfuric acid, dilute hydrochloric  acid, copper, magnesium oxide and zinc carbonate?  a 3 b 4 c 5 d 6      22 elements in group i of the periodic table react with water.    which row describes the products made in the reaction and the trend in reactivity of the elements?     products trend in reactivity  a metal hydroxide and hydrogen less reactive down the group  b metal hydroxide and hydrogen more reactive down the group  c metal oxide and hydrogen less reactive down the group  d metal oxide and hydrogen more reactive down the group      23 the graph shows how the ph of soil in a field changes over time.    at which point was the soil neutral?    11 9 753ph of soil timea b cd      ",
            "8": "8  \u00a9 ucles 2014 0620/12/o/n/14  24 the table shows the reactions of four different metals with water.    metal reaction  w reacts vigorously with cold water  x no reaction with water  y reacts very slowly with water, more vigorously with steam  z reacts violently with cold water    what is the correct order of reactivity, from most reactive to least reactive?  a w \u2192 x \u2192 y \u2192 z  b w \u2192 z \u2192 y \u2192 x  c z \u2192 w \u2192 x \u2192 y  d z \u2192 w \u2192 y \u2192 x      25 an inert gas x is used to fill weather balloons.    which descriptions of x are correct?     number of outer  electrons in atoms of x structure of gas x  a 2 single atoms  b 2 diatomic molecules  c 8 single atoms  d 8 diatomic molecules      26 an element x has the two properties listed.    1 it acts as a catalyst.  2 it forms colourless ions.    which of these properties suggest that x is a transition element?     property 1 property 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "9": "9  \u00a9 ucles 2014 0620/12/o/n/14 [turn over  27 the oxide of element x is reduced by heating with carbon.    element x does not react with cold water, steam or dilute hydrochloric acid.    what is x?  a copper  b iron  c magnesium  d zinc      28 which information about an element can be used to predict its chemical properties?  a boiling point  b density  c melting point  d position in the periodic table      29 aluminium is the most common metal in the earth\u2019s crust.    which is not a property of aluminium?   a low density  b resistance to corrosion  c good conductor of electricity  d poor conductor of heat     30 which reaction involves oxidation?  a heating hydrated copper( ii) sulfate in the air  b polymerisation of ethene  c rusting of iron  d thermal decomposition of calcium carbonate     31 which object is least  likely to contain aluminium?  a a bicycle frame  b a hammer  c a saucepan  d an aeroplane body    ",
            "10": "10  \u00a9 ucles 2014 0620/12/o/n/14  32 which method can be used to obtain ammonia from ammonium sulfate?  a heat it with an acid.  b heat it with an alkali.  c heat it with an oxidising agent.  d heat it with a reducing agent.      33 which is an air pollutant that affects a part of the body other than the lungs and blood system?  a lead compounds  b nitrogen  c oxides of nitrogen  d sulfur dioxide     34 which statement about methane is not correct?  a it is a liquid produced by distilling petroleum.  b it is produced as vegetation decomposes.  c it is produced by animals, such as cows.  d it is used as a fuel.    35 which method of purification would produce water most  suitable for drinking?    muddy river waterpurified waterfiltration filtration filtrationsettlementchlorination chlorinationa b cd      ",
            "11": "11  \u00a9 ucles 2014 0620/12/o/n/14 [turn over  36 which molecular structure shows hexene?    h ch hhhhhhh h hh c c c c ca h ch hhhhhh h h hoho c c c ccdh ch hhhhhhh c c chh chh h cb h ch hhhhhhh c c chh chh o h cc      37 increasing the number of atoms in one molecule of a hydrocarbon increases the amount of  energy released when it burns.    what is the correct order?     less energy  released  more energy  released  a ethene ethane methane  b ethene methane ethane  c methane ethane ethene  d methane ethene ethane    38 which statement about alkenes is not correct?  a the functional group is c=c.  b the structural difference between one member and the next is \u2013  ch 3 \u2013.  c they form a homologous series.  d they turn aqueous bromine from brown to colourless.    ",
            "12": "12  \u00a9 ucles 2014 0620/12/o/n/14  39 the diagram shows three repeat units in the structure of an addition polymer.    ch hccl hcchhchclhhccl h     which alkene monomer is used to make this polymer?    cc hh clh cc hcl clh hhcl ch hc hhhcl cl chchabcd       40 ethanol can be manufactured from substance x.    substance x  +  steam ethanolcatalyst     what is substance x?  a carbon dioxide  b ethene  c hydrogen  d oxygen     ",
            "13": "13  \u00a9 ucles 2014 0620/12/o/n/14  blank page ",
            "14": "14  \u00a9 ucles 2014 0620/12/o/n/14  blank page ",
            "15": "15  \u00a9 ucles 2014 0620/12/o/n/14  blank page",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2014 0620/12/o/n/14   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w14_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 14 printed pages and 2 blank pages.  ib14 11_0620_13/3rp  \u00a9 ucles 2014 [turn over       *0100096687* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  october/november 2014       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2014 0620/13/o/n/14  1 a few drops of perfume were spilt on the floor. a few minutes later the perfume could be smelt a  few metres away.    which two processes had taken place?  a distillation and condensation  b distillation and diffusion  c evaporation and condensation  d evaporation and diffusion     2 the diagram shows three pieces of apparatus that are used for measuring the volume of a liquid.    123    what are these pieces of apparatus?     1 2 3  a burette measuring cylinder pipette  b burette pipette measuring cylinder c measuring cylinder burette pipette  d measuring cylinder pipette burette    ",
            "3": "3  \u00a9 ucles 2014 0620/13/o/n/14 [turn over  3 a student is investigating a coloured mixture using chromatography.    paper pencil line solvent    where should he place the coloured mixture?  a in the solvent  b just above the pencil line  c just below the pencil line  d on the pencil line     4 which statement about a neutron is not correct?  a it can be present in different numbers in atoms of the same element.  b it has no electrical charge.  c it is always found in the nucleus of an atom.  d it weighs much less than a proton.    5 which element has the atomic structure shown?    ekey electron nucleus16nnneutron eeeee ee ee ee ee ee     a a l b  p c  s d  si    ",
            "4": "4  \u00a9 ucles 2014 0620/13/o/n/14  6 slate has a layered structure and can easily be split into thin sheets.    which diagram shows a structure most like that of slate?    b a cd       7 element x, x19 9, forms a compound with element y, y39 19.    which statement describes the bonding in the compound formed?  a x and y share electrons.  b x gives away one electron to y.  c y gives away one electron to x.  d y gives away two electrons to x.      8 which substance is methane?     volatility electrical conductivity  at room temperature solubility in water  a high good soluble  b high poor insoluble  c low good soluble  d low poor insoluble     9 the table shows the numbers of atoms present in the formula of some compounds.    which row is not correct?     numbers of atoms formula  a 1 \u00d7 calcium, 1 \u00d7 carbon, 3 \u00d7 oxygen caco 3  b 1 \u00d7 carbon, 5 \u00d7 hydrogen, 1 \u00d7 oxygen c 2h5oh  c 1 \u00d7 hydrogen, 1 \u00d7 oxygen, 1 \u00d7 sodium naoh  d 2 \u00d7 hydrogen, 4 \u00d7 oxygen, 1 \u00d7 sulfur h 2so 4    ",
            "5": "5  \u00a9 ucles 2014 0620/13/o/n/14 [turn over  10 an element, x, can be represented as xa b.    which statement is correct?  a the number of protons in an atom of x is a.  b the exact position of x in the periodic table can be found from a.  c the relative atomic mass of x is b.  d the total number of electrons in one atom of x is b.      11 a student wishes to electroplate an object with copper.    which row is correct?     object is made  the a suitable  electrolyte is  a anode cuo(s)  b anode cuso 4(aq)  c cathode cuo(s)  d cathode cuso 4(aq)    12 in the electrolysis shown, chlorine is produced at w and sodium at x.    +\u2013wx y     which labels are correct?     w x y  a anode cathode nac l (l)  b anode cathode nac l (aq)  c cathode anode nac l (l)  d cathode anode nac l (aq)    ",
            "6": "6  \u00a9 ucles 2014 0620/13/o/n/14  13 what occurs when a fuel burns?      fuel reacts  with oxygen energy  change  a no endothermic  b no exothermic  c yes endothermic  d yes exothermic     14 which fuel does not produce air pollution when it burns?  a coal  b diesel oil  c hydrogen  d gasoline (petrol)    15 which graph shows the effect of increasing temperature on the rate of reaction of calcium  carbonate with dilute hydrochloric acid?    rate temperaturea 00rate temperatureb 00 rate temperaturec 00rate temperatured 00      ",
            "7": "7  \u00a9 ucles 2014 0620/13/o/n/14 [turn over  16 the diagram shows the change from an anhydrous salt to its hydrated form.    hydrated salt anhydrous saltforward reverse    which statement is correct?    a forward reaction requires heat and water  b forward reaction requires water only  c reverse reaction requires heat and water  d reverse reaction requires water only      17 the equations for two reactions p and q are given.    p 2nano 2  +  o 2  \u2192  2nano 3  q 2hgo  \u2192  2hg  +  o 2    in which of these reactions does oxidation of the underlined substance occur?     p q  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     18 which changes decrease the rate of reaction between magnesium and air?    1 heating the magnesium to a higher temperature  2 using a higher proportion of oxygen in the air  3 using magnesium ribbon instead of powdered magnesium    a 1, 2 and 3 b 1 only c 2 only d 3 only     19 a colourless solution is tested by the following reactions.    which reaction is not characteristic of an acid?  a a piece of magnesium ribbon is added. bubbles are seen and the magnesium disappears.  b a pungent smelling gas is produced when ammonium carbonate is added.  c copper oxide powder is added and the mixed is warmed. the solution turns blue.  d the solution turns blue litmus red.   ",
            "8": "8  \u00a9 ucles 2014 0620/13/o/n/14  20 which statement about oxides is correct?  a a solution of magnesium oxide will have a ph less than 7.  b a solution of sulfur dioxide will have a ph greater than 7.  c magnesium oxide will react with nitric acid to make a salt.  d sulfur dioxide will react with hydrochloric acid to make a salt.      21 which salt preparation uses a burette and a pipette?  a calcium nitrate from calcium carbonate and nitric acid  b copper( ii) sulfate from copper( ii) hydroxide and sulfuric acid  c potassium chloride from potassium hydroxide and hydrochloric acid  d zinc chloride from zinc and hydrochloric acid     22 the graph shows how the ph of soil in a field changes over time.    at which point was the soil neutral?    11 9 753ph of soil timea b cd       23 which statement about the elements of group i is correct?  a lithium is more dense than sodium.  b potassium has a higher density than lithium.  c potassium is less reactive than sodium.  d sodium has a higher melting point than lithium.     ",
            "9": "9  \u00a9 ucles 2014 0620/13/o/n/14 [turn over  24 an element x has the two properties listed.    1 it acts as a catalyst.  2 it forms colourless ions.    which of these properties suggest that x is a transition element?     property 1 property 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      25 an inert gas x is used to fill weather balloons.    which descriptions of x are correct?     number of outer  electrons in atoms of x structure of gas x  a 2 single atoms  b 2 diatomic molecules  c 8 single atoms  d 8 diatomic molecules      26 the metal beryllium does not react with cold water.    it reacts with hydrochloric acid but cannot be extracted from its ore by using carbon.    where should it be placed in the reactivity series?  magnesium  a  zinc  b  iron  c  copper  d     ",
            "10": "10  \u00a9 ucles 2014 0620/13/o/n/14  27 which information about an element can be used to predict its chemical properties?  a boiling point  b density  c melting point  d position in the periodic table      28 a list of properties of aluminium is shown.    1 it conducts heat.  2 it has a low density. 3 it is resistant to corrosion.    which properties make aluminium useful for making food storage containers?  a 1, 2 and 3 b 1 and 3 only c 1 only d 3 only      29 which metal is commonly used to form alloys with a non-metallic element?    a copper  b iron  c magnesium  d zinc     30 which object is least  likely to contain aluminium?  a a bicycle frame  b a hammer  c a saucepan  d an aeroplane body    31 which process does not involve oxidation?  a burning a fossil fuel  b conversion of iron from the blast furnace into steel  c distillation of crude oil  d rusting of iron    ",
            "11": "11  \u00a9 ucles 2014 0620/13/o/n/14 [turn over  32 which pair of compounds would make a n, p, k fertiliser?  a ammonium sulfate and potassium phosphate  b calcium hydroxide and ammonium nitrate  c calcium phosphate and potassium chloride  d potassium nitrate and ammonium sulfate.      33 which method of purification would produce water most  suitable for drinking?    muddy river waterpurified waterfiltration filtration filtrationsettlementchlorination chlorinationa b cd       34 which statement about methane is not correct?  a it is a liquid produced by distilling petroleum.  b it is produced as vegetation decomposes.  c it is produced by animals, such as cows.  d it is used as a fuel.    35 a man blows up a balloon.    what is the approximate composition of his exhaled air in the balloon?     % composition  carbon dioxide oxygen nitrogen  a 0.03 20 79  b 0.03 79 20  c 4 16 79  d 4 20 75     ",
            "12": "12  \u00a9 ucles 2014 0620/13/o/n/14  36 increasing the number of atoms in one molecule of a hydrocarbon increases the amount of  energy released when it burns.    what is the correct order?     less energy  released  more energy  released  a ethene ethane methane  b ethene methane ethane  c methane ethane ethene  d methane ethene ethane      37 the list gives the names of four organic compounds.    ethane  ethanoic acid ethanol  ethene    which bond do all four compounds contain?  a c\u2013c b c=c c c\u2013h d c\u2013o      38 the diagram shows a reaction sequence.    butane ethene ethanolcarbon dioxide and waterxyz     which row names the processes x, y and z?    x y z  a cracking fermentation respiration  b cracking hydration combustion  c distillation fermentation respiration  d distillation hydration combustion    ",
            "13": "13  \u00a9 ucles 2014 0620/13/o/n/14  39 the main constituent of natural gas is hydrocarbon x.    to which homologous series does x belong and how many atoms  are in one molecule of x?     homologous series number of atoms  in one molecule  a alkane 1  b alkane 5  c alkene 1  d alkene 5      40 the equation shows an industrial process.     catalyst  h2o  +  c 2h4    compound x    what is the name of compound x?  a ethane  b ethanoic acid  c ethanol  d methanol     ",
            "14": "14  \u00a9 ucles 2014 0620/13/o/n/14  blank page ",
            "15": "15  \u00a9 ucles 2014 0620/13/o/n/14  blank page",
            "16": "16      permission to reproduce items where thir d-party owned material protected by copyright  is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2014 0620/13/o/n/14   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w14_qp_21.pdf": {
            "1": "this document consists of 16 printed pages. [turn overib14 11_0620_21/3rp \u00a9 ucles 2014 *4095387716* read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 october/november 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/21/o/n/14 \u00a9 ucles 20141  the structures of \ufb01 ve carbon compounds are shown below. cco ohh hhhhhh ccbr hbr hcc h h hab dec hhh cc h hhhc hh hc h  (a)  answer the following questions about these compounds. each compound may be used once,  more than once or not at all.  (i)  which compound, a, b, c, d or e, is ethanoic acid?  ...  [1]  (ii)  which two compounds are saturated hydrocarbons? . and  .  [1]  (iii)  which compound is the main constituent of natural gas?    [1]  (iv)  which compound reacts with steam to form ethanol?  ..  [1]  (v)  which compound is causing concern as a greenhouse gas?  ..  [1]  (vi)  which two compounds are in the same homologous series?  and  ..  [1]  (b)  deduce the molecular formula for compound c.   ... ...  [1]  (c)  complete the symbol equation for the complete combustion of compound a.  c3h8   +   .o2    \u2192    3co2    +    .h2o [2] [total: 9]",
            "3": "3 0620/21/o/n/14 \u00a9 ucles 2014 [turn over2  the diagram shows a bottle of mineral water. the concentration of the ions present in the water is  shown on the label. the ph of the water is also shown. poly(ethene) bottleions present ph = 6.6chloride, c l \u2013 x, f\u2013 magnesium, mg2+ manganese, mn2+ y, no3\u2013 potassium, k+ sodium, na+concentration in mg  / 1000  cm3 0.71 0.310.020.010.700.441.22  (a) (i)   which positively charged ion is present in the highest concentration?   . ..  [1]  (ii)  state the name of:  ion x  . ..  ion y  . .. [2]  (iii)  calculate the mass, in mg, of sodium ions in 200  cm3 of mineral water. . mg  [1]  (iv)  which one of the following phrases best describes the ph of this mineral water?   tick one box.  neutral strongly acidic strongly alkaline weakly acidic weakly alkaline [1]  (b)  describe a test for chloride ions.  test   .  result  ..  [2]",
            "4": "4 0620/21/o/n/14 \u00a9 ucles 2014 (c)  the mineral water bottle is made of poly(ethene).   complete the following sentence about poly(ethene) using words from the list below. atom      ionic      monomer      polymer      reactant      saturated   poly(ethene) is a . made by the addition of . units. [2] [total: 9] 3  rose oil contains 2-phenylethanol.   the structure of 2-phenylethanol is shown below. cc cch cch hh h hc h ch ho h  (a)  on the structure above, draw a ring around the alcohol functional group. [1]  (b)  when heated with an alkali, 2-phenylethanol forms styrene.   styrene is an unsaturated compound.   describe a test for an unsaturated compound.  test   .  result  ..  [2]  (c)  rose petals contain a variety of different coloured pigments.   a student wants to identify these pigments.  (i)  she grinds up rose petals with a solvent.   explain why.   .    .    . ..  [2]  (ii)  she then \ufb01 lters the solution through some glass wool.   suggest why she does not use \ufb01 lter paper.   . ..  [1]",
            "5": "5 0620/21/o/n/14 \u00a9 ucles 2014 [turn over (d)   the student uses the apparatus shown below to identify the different pigments in the mixture. glass cover filter paper pure solvent  (i)  state the name of this method of separating the pigments.   . ..  [1]  (ii)  on the diagram above, draw a spot, \u25cf, to show where the mixture of pigments is placed at  the start of the experiment. [1]  (iii)  what is the purpose of the glass cover?   . ..  [1]  (iv)  the student also puts four spots of pure pigments, a, b, c and d, onto the \ufb01 lter paper.   the diagram below shows the results of her experiment. pigments from rose petalabcd   which of the pigments, a, b, c and d, are present in the rose petals?   . ..  [1]",
            "6": "6 0620/21/o/n/14 \u00a9 ucles 2014 (e)  the solvent used in the experiment is ethanol.   draw the structure of a molecule of ethanol showing all atoms and bonds. [2] [total: 12]",
            "7": "7 0620/21/o/n/14 \u00a9 ucles 2014 [turn over4  a student wants to compare the energy released when different fuels are burned.   he measures the increase in temperature of the water in a metal can when the fuels are burned. clamp water metal can glass spirit burner fuel top-pan balance  (a)  what piece of apparatus is missing from the diagram above?   ... ...  [1]  (b)  state two things the student should keep the same when burning each fuel.   ... .   ... .   ... ...  [2]  (c)  suggest why the water in the can should be stirred.   ... .   ... ...  [1]  (d)  what happens to the reading on the top-pan balance as the fuel burns?   give a reason for your answer.   ... .   ... ...  [2]",
            "8": "8 0620/21/o/n/14 \u00a9 ucles 2014 (e)  the results of burning four fuels, d, e, f and g, are shown in the table below. fueltemperature of water at start of experiment  / \u00b0ctemperature of water at end of experiment  / \u00b0c d 20 45 e 19 43 f 16 44 g 21 46   which fuel produced the greatest temperature rise in the water?   ... ...  [1]  (f)  the metal can is made of mild steel coated with tin.  (i)  steel is an alloy.  what is meant by the term alloy?   .    . ..  [1]  (ii) why does the tin prevent the steel can from rusting?   .    . ..  [2]  (g)  glass is made from silicon( iv) oxide.   part of the structure of silicon dioxide is shown below. oxygen atom silicon atom   which one of the following best describes the structure of silicon dioxide?   tick one box.  giant covalent giant ionic simple atomic simple molecular [1] [total: 11]",
            "9": "9 0620/21/o/n/14 \u00a9 ucles 2014 [turn over5 (a)   describe how acids react with metals and with metal oxides.   in your answer:  \u25cf refer to a particular metal and metal oxide,  \u25cf illustrate your answer with at least one word equation.   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  when metals react with hydrochloric acid, the temperature of the reaction mixture increases.   which one of the following words best describes this reaction?   draw a ring around the correct answer. endothermic       exothermic       isotopic       radioactive [1]  (c)  uranium is a metal which has several radioactive isotopes. some of these are used as sources  of energy.   state one other use of radioactive isotopes.   ... ...  [1]  (d)  complete the table below to show the number of protons, neutrons and electrons in two  isotopes of uranium. isotope235u92238u92 protons neutronselectrons [3] [total: 9]",
            "10": "10 0620/21/o/n/14 \u00a9 ucles 20146  the organic compound 1-bromobutane reacts with excess sodium hydroxide to form butan-1-ol.   a scientist studied the rate of this reaction by \ufb01 nding out how the concentration of sodium hydroxide  changed with time.   the graph below shows the results. 0.25 0.200.150.100.050.00 0246 time  / hoursconcentration of sodium hydroxidein mol  / dm3 81 0 1 2  (a) (i)   describe how the concentration of sodium hydroxide changes with time.   .    . ..  [2]  (ii)  determine the time it took for the concentration of sodium hydroxide to fall to 0.15  mol  / dm3.   . ..  [1]  (iii)  at what time was the reaction complete?   . ..  [1]  (iv)  on the grid above, draw a line to show how the concentration of sodium hydroxide changes  when the concentration of 1-bromobutane in the reaction mixture is increased.   all other conditions remain the same. [2]  (v)  increasing the concentration of 1-bromobutane increases the rate of this reaction.   suggest one other way of increasing the rate of this reaction.   . ..  [1]",
            "11": "11 0620/21/o/n/14 \u00a9 ucles 2014 [turn over (b)  the concentration of aqueous sodium hydroxide can be found by titrating samples of the  reaction mixture with hydrochloric acid.   describe how you would carry out this titration.   in your answer, refer to:  \u25cf a burette,  \u25cf a volumetric pipette,  \u25cf an acid-base indicator solution.   ... .   ... .   ... .   ... .   ... ...  [4]  (c)  hydrochloric acid is made by dissolving hydrogen chloride gas, hc l, in water.   draw a dot-and-cross diagram to show a molecule of hydrogen chloride.   show hydrogen electrons as x.   show chlorine electrons as \u25cf. [2] [total: 13]",
            "12": "12 0620/21/o/n/14 \u00a9 ucles 20147  fertilisers usually contain compounds of nitrogen, phosphorus and potassium.  (a)  why do farmers use fertilisers?   ... ...  [1]  (b)  many fertilisers contain ammonium sulfate.   ammonium sulfate is made by reacting aqueous ammonia with sulfuric acid.   what type of chemical reaction is this?   ... ...  [1]  (c)  aqueous ammonia reacts with nitric acid to make another compound often found in fertilisers.   state the name of this compound.   ... ...  [1]  (d)  the structure of ammonium sulfate is shown below. so42\u2013nh4+ nh4+nh4+ so42\u2013so42\u2013nh4+ nh4+nh4+nh4+ so42\u2013nh4+ so42\u2013nh4+ so42\u2013nh4+nh4+nh4+   deduce the simplest ratio of ammonium and sulfate ions in ammonium sulfate.   ... ...  [1]  (e)  ammonium salts react with alkalis. for example: ammonium sulfate+sodium hydroxide\u2192sodium sulfate +    ammonia    +    water   use this information to explain why adding slaked lime to \ufb01 elds which have fertilisers spread  on them may result in loss of nitrogen.   ... .   ... .   ... ...  [2]",
            "13": "13 0620/21/o/n/14 \u00a9 ucles 2014 [turn over (f)  many fertilisers contain potassium chloride.   when molten potassium chloride is electrolysed, two products are formed.   complete the table below to show the name of the electrodes and the products formed. charge on the electrodename of the electrodeproduct formed at the electrode positive negative [3] [total: 9]",
            "14": "14 0620/21/o/n/14 \u00a9 ucles 20148 (a)   a student placed a crystal of iodine in a test tube of solvent.   after two minutes, a dense violet colour was observed at the bottom of the test-tube. after  three hours, the violet colour had spread throughout the solvent. at the startafter 2 minutesafter 3 hourssolvent   use the kinetic particle theory to explain these observations.   in your answer, refer to:  \u25cf  the arrangement and motion of the molecules in the iodine crystal,  \u25cf  the arrangement and motion of the molecules in the solution,  \u25cf  the names of the processes which are occurring.   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  astatine, at, is below iodine in group vii of the periodic table.  (i)  the table shows the states of the group vii elements at room temperature. element state \ufb02 uorine gas chlorine gas bromine liquid iodine solid   use this information to deduce the state of astatine at room temperature.   . ..  [1]",
            "15": "15 0620/21/o/n/14 \u00a9 ucles 2014 [turn over (ii)  astatine is radioactive. a lot of heat is given off due to this radioactivity.   the small samples of astatine that have been isolated are often liquid.   suggest why they are often liquid.   . ..  [1]  (iii)  although few compounds of astatine have been made, scientists think that sodium astatide  will react with iodine.   complete the equation for this reaction. i2   +   .naat   \u2192   2na i   +    [2] [total: 8]",
            "16": "16 0620/21/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w14_qp_22.pdf": {
            "1": "this document consists of 17 printed pages and 3 blank pages. [turn overib14 11_0620_22/2rp \u00a9 ucles 2014 *4078903609* read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 20. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 october/november 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/22/o/n/14 \u00a9 ucles 20141 (a)   the electronic structure of \ufb01 ve atoms, a, b, c, d and e, are shown below. e d c b a   answer the following questions about these structures.   each structure can be used once, more than once or not at all.   which structure:  (i)  represents an atom of an element in group v of the periodic table,  ...  [1]  (ii)  has a complete outer shell of electrons,  ...  [1]  (iii)  represents an oxygen atom,  .  [1]  (iv)  has a proton number of 20,  ..  [1]  (v)  is an atom of an element in period 4 of the periodic table,  .  [1]  (vi)  has a single valency electron?  .  [1]  (b)  complete the following sentences about isotopes using words from the list below. atoms        ions        molecules        neutrons        nuclei        protons   isotopes are .. of the same element with the same number of ..   but different numbers of .. . [3] [total: 9]",
            "3": "3 0620/22/o/n/14 \u00a9 ucles 2014 [turn over2  the table below shows some nutritional information on a bottle of apple juice. contentsmass present in g  / 100  cm3 protein 0.10 sugars 10.40unsaturated fat 0.10saturated fat 0.06chloride ions, c l  \u20130.04 magnesium ions, mg2+0.01 nitrate ions, no3\u20130.01 potassium ions, k+0.02 sodium ions, na+0.05 x, so42\u20130.01  (a)  answer these questions using information from the table.  (i)  which negatively charged ion is present in the highest concentration?   . ..  [1]  (ii)  state the name of the ion, x, whose formula is so42\u2013.   . ..  [1]  (iii)  the formulae for some chlorides are shown below.  aluminium chloride, a l cl 3  calcium chloride, cac l 2  lead( iv) chloride, pbc l 4  potassium chloride, kc l  deduce the formula for magnesium chloride.   . ..  [1]  (iv)  calculate the mass of sugars in 250  cm3 of this apple juice. ... g  [1]",
            "4": "4 0620/22/o/n/14 \u00a9 ucles 2014 (b)  the fats in the apple juice are both saturated and unsaturated.   describe a test to distinguish between saturated and unsaturated compounds.  test   .  result with saturated compound  .  result with unsaturated compound  . [3]  (c)  apple juice is slightly acidic.  (i)  which one of the following ph values is slightly acidic?   put a ring around the correct answer. ph 1            ph 5            ph 7            ph 9            ph 14 [1]  (ii)  one of the acids found in apple juice is malic acid.   the structure of malic acid is shown below. o oooh c co h h c c hh h   on the structure of malic acid above, put a ring around a carboxylic acid functional  group. [1] [total: 9]",
            "5": "5 0620/22/o/n/14 \u00a9 ucles 2014 [turn over3  hydrogen chloride gas can be prepared by the action of concentrated sulfuric acid on sodium  chloride. h2so4  +  2nac l  \u2192  na2so4  +  2hc l  (a)  write the word equation for this reaction.   ... ...  [1]  (b)  hydrogen chloride dissolves in water to form hydrochloric acid.  (i)  complete the dot-and-cross diagram to show the arrangement of the outer shell electrons  in water. o h h [2]  (ii)  describe what you would observe when a few drops of silver nitrate solution are added to  hydrochloric acid.   . ..  [2]",
            "6": "6 0620/22/o/n/14 \u00a9 ucles 2014 (c)  the graph below shows how ph changes when aqueous ammonia is neutralised by hydrochloric  acid. 14 1210 86420 0 5 10 15 volume of hydrochloric acid added  / cm320 25 30ph  (i)  what is the ph of the aqueous ammonia at the start of the experiment?   . ..  [1]  (ii)  what volume of hydrochloric acid has been added when the ph is 10?   . ..  [1]  (iii)  what volume of hydrochloric acid has been added when the ph is changing most quickly?   . ..  [1]",
            "7": "7 0620/22/o/n/14 \u00a9 ucles 2014 [turn over (d)  concentrated hydrochloric acid reduces manganese( iv) oxide, mno2, to manganese( ii)  chloride. 4hc l  +  mno2  \u2192  mnc l 2  +  c l 2  +  2h2o   how does this equation show that manganese( iv) oxide gets reduced?   ... ...  [1]  (e)  the table shows some properties of four metals, a, b, c and d, and their oxides. metaldensity in g  / cm3boiling point / \u00b0ccolour of oxidecharge on the metal ion a 2.99 2831 white 3+ b 0.53 1342 white 1+ c 7.86 2750 black or red-brown 2+ or 3+ d 7.14 907 white 2+   which one of these metals is a transition metal?   use the information in the table to explain your answer.   ... .   ... .   ... ...  [2] [total: 11]",
            "8": "8 0620/22/o/n/14 \u00a9 ucles 20144  calcium carbonate reacts with dilute hydrochloric acid.  (a)  complete the symbol equation for this reaction. caco3   +   ..hc l   \u2192   cac l 2   +   co2   +    [2]  (b)  the rate of this reaction can be followed using the apparatus shown below. a bhydrochloric acidcotton wool calcium carbonate  (i)  state the names of the pieces of apparatus labelled a and b.  a  .   b  .  [2]  (ii)  explain why the mass of the reaction mixture decreases with time.   . ..  [1]",
            "9": "9 0620/22/o/n/14 \u00a9 ucles 2014 [turn over (c)  the graph below shows how the mass of the reaction mixture changes with time.   the calcium carbonate was in excess and large pieces of calcium carbonate were used. 100.25 100.20100.15100.10100.05 100.00 0 100 200 300 time  / s400 500 600 700mass of reactionmixture  / g  (i)  at what time was the reaction just complete?   . ..  [1]  (ii)  calculate the total loss in mass of the reaction mixture in this experiment.   . ..  [1]  (iii)  how does the rate of reaction change when:   smaller pieces of calcium carbonate are used,   .    the temperature is decreased,   .    the concentration of hydrochloric acid is decreased?   .  [3]",
            "10": "10 0620/22/o/n/14 \u00a9 ucles 2014 (d)  when heated, calcium carbonate breaks down to form calcium oxide and carbon dioxide.   which two words from the list below describe this reaction?   tick two boxes.  combustion decomposition endothermic exothermic oxidation [2]  (e)  calcium oxide is used in \ufb02 ue-gas desulfurisation.  (i)  explain how \ufb02 ue-gas desulfurisation works.   .    .    . ..  [2]  (ii)  give one other use of calcium oxide.   . ..  [1] [total: 15]",
            "11": "11 0620/22/o/n/14 \u00a9 ucles 2014 [turn over5  the structures of graphite and sodium chloride are shown below. ccc ccc cc ccc ccc cc cc ccc ccc cccc cc ccc ccc cc cc graphite sodium chloridena+cl \u2013 cl \u2013na+ na+cl \u2013na+cl \u2013 cl \u2013na+ na+cl \u2013  (a)  describe the similarity and differences in these structures.   ... .   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  graphite is a form of carbon.   carbon is an element.  (i)  what is meant by the term element  ?   .    . ..  [1]  (ii)  write a symbol equation for the complete combustion of carbon. [2]",
            "12": "12 0620/22/o/n/14 \u00a9 ucles 2014 (c)  the table shows some properties of four substances, a, b, c and d. substancemelting point / \u00b0cboiling point / \u00b0celectrical conductivity a \u20137 +59 does not conduct b \u2013157 \u2013152 does not conduct c +769 +1930 conducts when molten but not when solid d +1410 +2355 does not conduct   which one of these substances, a, b, c or d,  (i)  is a liquid at room temperature,    [1]  (ii)  is a giant ionic structure,  ...  [ 1]  (iii)  is a noble gas,  ..   [1]  (iv)  is a giant covalent structure?    [1] [total: 11]",
            "13": "13 0620/22/o/n/14 \u00a9 ucles 2014 [turn over6  the table below shows some properties of the \ufb01 rst \ufb01 ve members of the alkane homologous series. alkanemolecular formulaboiling point / \u00b0cdensity of the liquid alkane in g  / cm3 methane ch4 \u2013164 0.47 ethane c2h6 \u201388 propane c3h8 \u201342 0.59 butane c4h10 0 0.60 pentane +36 0.63  (a) (i)   what do you understand by the term homologous series  ?   .    . ..  [2]  (ii)  deduce the molecular formula for pentane.   . ..  [1]  (iii)  describe how the boiling points of these alkanes change as the number of carbon atoms  increases.   . ..  [1]  (iv)  deduce the density of liquid ethane.   . ..  [1]  (b)  methane is a fuel which is a gas at room temperature.   state the name of a fuel which is:  a solid at room temperature,  ..  a liquid at room temperature.  . [2]",
            "14": "14 0620/22/o/n/14 \u00a9 ucles 2014 (c)  the diagram below shows a distillation column used to separate petroleum into different  fractions.  (i)  on the diagram above:  \u25cf  put a letter x to show where the temperature in the column is lowest,  \u25cf  put a letter f to show where the fraction containing the largest molecules is collected,  \u25cf  put a letter m to show where petroleum enters the distillation column. [3]  (ii)  the re \ufb01 nery gas fraction contains ethane.   hydrogen is one of the products formed when ethane is cracked.   complete the symbol equation for the cracking of ethane. c2h6   \u2192      +    [2]  (iii)  state the conditions needed for cracking.   . ..  [2] [total: 14]",
            "15": "15 0620/22/o/n/14 \u00a9 ucles 2014 [turn over7  gallium and aluminium are in group iii of the periodic table.  (a)  the melting point of gallium is 30  \u00b0c.   use the kinetic particle theory to explain what happens when a spoon made of gallium is put  into a cup of tea at 40  \u00b0c.   in your answer, refer to:  \u25cf  the change of state which occurs,  \u25cf  the change in the arrangement of the particles,  \u25cf  the change in the motion of the particles.   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  gallium burns in air at a high temperature to form gallium( iii) oxide.   complete the symbol equation for this reaction. ..ga   +   3o2   \u2192   ..ga2o3 [2]  (c)  explain why aluminium is often used in containers for food and drinks.   ... .   ... ...  [2]",
            "16": "16 0620/22/o/n/14 \u00a9 ucles 2014 (d)   aluminium chloride can be made by heating aluminium foil in a stream of chlorine. chlorinealuminium foil aluminium chloride  (i)  on the diagram above, draw an arrow to show where heat should be applied. [1]  (ii)  at temperatures between 178 \u00b0c and 400  \u00b0c, aluminium chloride has the structure shown  below. clalcl clcl clalcl   deduce the molecular formula of this structure.   . ..  [1]  (iii)  some properties of aluminium and silver are shown in the table below. costdensity in g  / cm3electrical conductivitymelting point / \u00b0c aluminium high 2.7 good 660 silver very high 10.5 very good 962   use the information in the table to suggest why aluminium rather than silver is used in  overhead power cables.   . ..  [1] [total: 11]",
            "17": "17 0620/22/o/n/14 \u00a9 ucles 2014blank page",
            "18": "18 0620/22/o/n/14 \u00a9 ucles 2014blank page",
            "19": "19 0620/22/o/n/14 \u00a9 ucles 2014blank page",
            "20": "20 0620/22/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w14_qp_23.pdf": {
            "1": "this document consis ts of 16 printed pages . [turn overib14 11_0620_23/3rp \u00a9 ucles 2014 *3304301344* read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/23   paper 2 october/november 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/23/o/n/14 \u00a9 ucles 20141 (a)   the structures of \ufb01 ve substances, a, b, c, d and e, are shown below. br \u2013br \u2013k+ br \u2013k+ k+br \u2013br \u2013k+ br \u2013k+ k+abc des sss ss ssoc o ccc c ccc cccc ccc cc cc ccc ccc cccc cc ccc ccc cc ccf f fff fs   answer the following questions about these substances.   each substance may be used once, more than once or not at all.  (i)  which two substances are elements?    and    [2]  (ii)  which substance has a giant ionic structure?    [1]  (iii)  which substance is a product formed when a hydrocarbon is completely burnt in air?   [1]  (iv)  which substance, when molten, produces a brown vapour at the anode when electrolysed?   [1]  (v)  which substance is used as a lubricant?   [1]  (b) deduce the simplest formula of substance a.   ... ...  [1]  (c)  calculate the relative molecular mass of substance e.   you must show your working. [2] [total: 9]",
            "3": "3 0620/23/o/n/14 \u00a9 ucles 2014 [turn over2 (a)   use ideas about the movement and arrangement of particles to explain why:  \u25cf  solids have a definite volume and shape,  \u25cf  liquids have a definite volume but no definite shape,  \u25cf  gases have no definite volume or shape.   ... .   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  the table shows some properties of six substances, a to f, which are either solids or liquids  at room temperature. substancemelting point / \u00b0celectrical conductivitysolubility in water a +3550 does not conduct in any state insoluble b +44 does not conduct in any state insoluble c +1660 conducts when solid or liquid insoluble d +681 only conducts when in aqueous solution or liquid soluble e \u201339 conducts when solid or liquid insoluble f \u201311 does not conduct in any state insoluble  (i)  which substance has a giant covalent structure?   . ..  [1]  (ii)  which two substances are liquids at room temperature?   . ..  [2]  (iii)  which two substances are metals?   . ..  [2]  (iv)  which two substances are simple molecules?   . ..  [2]",
            "4": "4 0620/23/o/n/14 \u00a9 ucles 2014 (c)  dry air contains mainly nitrogen, noble gases and oxygen.  (i)  which one of the following shows the correct composition of dry air?   tick one box.  nitrogen 21%, oxygen 78%, noble gases 1% nitrogen 1%, oxygen 78%, noble gases 21% nitrogen 69%, oxygen 21%, noble gases 10% nitrogen 78%, oxygen 21%, noble gases 1% [1]  (ii)  metals can be joined together by high temperature welding.   this process is sometimes carried out in the presence of argon.   suggest why welding is carried out in the presence of argon.   .    . ..  [2] [total: 14]",
            "5": "5 0620/23/o/n/14 \u00a9 ucles 2014 [turn over3  rhubarb is a plant which has a red stem.  (a)  a student separated the pigments in the rhubarb stem by chromatography.   he used the apparatus shown below to extract the pigments. solvent a pieces of rhubarb  (i)  state the name of the piece of apparatus labelled a.   . ..  [1]  (ii)  suggest a suitable solvent, other than water, that he could use to extract the pigments.   . ..  [1]  (iii)  the solution of pigments was not concentrated enough to use for chromatography.   suggest how the student could make the solution more concentrated.   . ..  [1]  (b)  the student carried out chromatography using the apparatus shown below. chromatography paper chromatography jarlid for chromatography ja r solventy z  (i)  a spot of the pigment mixture was placed at y.   explain why a spot of the mixture was not placed at z.   . ..  [1]  (ii)  describe how the rest of the procedure was carried out.   .    .    . ..  [2]",
            "6": "6 0620/23/o/n/14 \u00a9 ucles 2014 (c)  rhubarb leaves contain ethanedioic acid.   the structure of ethanedioic acid is shown below. c c oo ooh h  (i)  on the structure above, put a ring around a carboxylic acid group. [1]  (ii)  deduce the molecular formula of ethanedioic acid.   . ..  [1]  (d)  a teacher heated ethanedioic acid with concentrated sulfuric acid.   the equation for the reaction is: cooh cooh(s)h2so4co(g)  +  co2(g)  +  x  (i)  deduce the formula of compound x.   . ..  [1]  (ii)  at the end of the reaction, the contents of the test-tube contained diluted sulfuric acid only.   explain why.   . ..  [1]  (iii)  carbon dioxide is a product of this reaction.   state one common source of the carbon dioxide in the atmosphere.   . ..  [1]  (iv)  explain why an increase in the concentration of carbon dioxide in the atmosphere is  harmful to the environment.   .    . ..  [2] [total: 13]",
            "7": "7 0620/23/o/n/14 \u00a9 ucles 2014 [turn over4  a mixture of soil and water was shaken and then \ufb01 ltered.  (a)  draw a labelled diagram of the apparatus you would use for separating the insoluble particles  of soil from the solution. [2]  (b)  the \ufb01 ltrate was then evaporated.   the table shows the composition and mass of each compound obtained by evaporating the  \ufb01 ltrate. compoundions present in the compoundmass of compound  / g calcium carbonate  ca2+ and co32\u20134.0 calcium sulfate  ca2+ and so42\u20135.0 magnesium sulfate  mg2+ and so42\u20132.8  k+ and no3\u20131.2 potassium sulfate  k+ and so42\u20132.4 sodium carbonate 3.0sodium chloride  na + and c l \u20131.6  (i)  state the name of the compound which contains k+ and no3\u2013 ions.   . ..  [1]  (ii)  write the symbols for the ions present in sodium carbonate.   . ..  [1]  (iii)  which compound with a singly charged negative ion has the highest mass in the mixture?   . ..  [1]",
            "8": "8 0620/23/o/n/14 \u00a9 ucles 2014  the table from page 7 is repeated below: compoundions present in the compoundmass of compound  / g calcium carbonate  ca2+ and co32\u20134.0 calcium sulfate  ca2+ and so42\u20135.0 magnesium sulfate  mg2+ and so42\u20132.8  k+ and no3\u20131.2 potassium sulfate  k+ and so42\u20132.4 sodium carbonate 3.0sodium chloride  na + and c l \u20131.6  (iv)  calculate:  the total mass of all the compounds present in the mixture,  . ..  [1]  the percentage of magnesium sulfate by mass in the mixture. [1]  (c)  calcium carbonate decomposes when heated.  (i)  complete the symbol equation for this reaction. caco 3  \u2192  cao  +  .. [1]  (ii)  calcium oxide, cao, reacts with water to form a strongly alkaline solution.   which one of the following ph values is strongly alkaline?   put a ring around the correct answer. ph  3                    ph  7                    ph  8                    ph  12 [1] [total: 9]",
            "9": "9 0620/23/o/n/14 \u00a9 ucles 2014 [turn over5  methanol reacts with excess hydrochloric acid to form chloromethane and water. methanol  +  hydrochloric acid  \u2192  chloromethane  +  water  (a)  to which homologous series does methanol belong?   ... ...  [1]  (b)  complete the structure of methanol below to show its functional group. c h hh [1]  (c)  methanol can be made from synthesis gas which contains carbon monoxide and hydrogen.   synthesis gas is made from methane.  (i)  complete the symbol equation for this reaction. ch4  +  h2o  \u2192  co  +  .h2 [1]  (ii)  suggest two hazards associated with the products of this reaction.   .    . ..  [2]",
            "10": "10 0620/23/o/n/14 \u00a9 ucles 2014 (d)  a student investigated the rate of reaction of methanol with hydrochloric acid.   the graph below shows how the concentration of hydrochloric acid changes with time. 1.0 0.80.60.40.2 0.0 0 1 02 03 0 time  / hours40 50 60 70concentration of hc l (aq) in mol  / dm3  (i)  describe how the concentration of hydrochloric acid changes with time.   .    . ..  [2]  (ii)  deduce the concentration of hydrochloric acid when the reaction had proceeded for 15 hours.   . ..  [1]  (iii)  at what time was the reaction just complete?   . ..  [1]  (iv)  on the grid above, draw a line to show how the concentration of hydrochloric acid changes  with time when the reaction takes place at a higher temperature. [2]",
            "11": "11 0620/23/o/n/14 \u00a9 ucles 2014 [turn over (e)  hydrochloric acid is formed when hydrogen chloride gas is dissolved in water.   draw a dot-and-cross diagram to show the electron arrangement in a molecule of hydrogen  chloride.   show only the outer electron shells.   show hydrogen electrons as x.   show chlorine electrons as \u25cf. [2] [total: 13]",
            "12": "12 0620/23/o/n/14 \u00a9 ucles 20146  sulfur burns in air to form sulfur dioxide.  (a) (i)   is sulfur dioxide an acidic or basic oxide?   give a reason for your answer.   .    . ..  [1]  (ii)  sulfur dioxide is an atmospheric pollutant.   explain why sulfur dioxide in the atmosphere can erode buildings made of limestone.   .    .    . ..  [3]  (b)  sulfur dioxide reacts with oxygen to form sulfur trioxide.   sulfur trioxide can be made in the laboratory using the apparatus shown below.   sulfur trioxide has a melting point of 17  \u00b0c and a boiling point of 45  \u00b0c. ice sulfur trioxide crystalssulfur dioxide oxygenplatinum catalyst concentrated sulfuric acid  (i)  suggest one safety precaution when carrying out this experiment.   . ..  [1]  (ii)  what is the purpose of the platinum catalyst?   . ..  [1]  (iii)  complete the symbol equation for the reaction. 2so2  +  ...  \u2192  .so3 [2]  (iv)  suggest why the sulfur trioxide is collected in a \ufb02 ask surrounded by ice.   . ..  [1]",
            "13": "13 0620/23/o/n/14 \u00a9 ucles 2014 [turn over (v)  when 64  g of sulfur dioxide react with excess oxygen, 80  g of sulfur trioxide is formed.   calculate the mass of sulfur trioxide formed from 160  g of sulfur dioxide. mass = . g  [1]  (c)  sulfur trioxide reacts with water to form sulfuric acid.   a student used the apparatus shown below to determine the concentration of a solution of  sodium hydroxide. sulfuric acid sodium hydroxide + indicator  (i)  which one of these pieces of apparatus should the student use to put 25.0  cm3 of sodium  hydroxide into the \ufb02 ask.   tick one box.  beaker measuring cylinder test-tube volumetric pipette [1]  (ii) how would the student know when the sulfuric acid had neutralised the sodium hydroxide?   . ..  [1]",
            "14": "14 0620/23/o/n/14 \u00a9 ucles 2014 (d)  clean air contains mainly nitrogen, noble gases, oxygen and water vapour.   a teacher left a beaker of concentrated sulfuric acid open to the air for a week.   after a week, the concentration of sulfuric acid in the beaker had decreased. at the start after one weekconcentrated sulfuric acid   explain these results by referring to one or more of the substances present in the air.   ... .   ... ...  [1] [total: 13]",
            "15": "15 0620/23/o/n/14 \u00a9 ucles 2014 [turn over7 (a)  describe the properties of chlorine, bromine and iodine.   in your answer, include the trends in:  \u25cf their state,  \u25cf their colour,  \u25cf their reactivity.   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  a molecule of chlorine can be written as c l \u2013 cl.   which one of the following words describes this molecule?   put a ring around the correct answer. diatomic           giant           ionic           monatomic [1]  (c)  draw the electronic structure of a \ufb02 uorine atom. [2]  (d)  the equation below describes the reaction of a halogen with a halide. br2  +  2k i  \u2192  i2  +  2kbr   write a word equation for this reaction. [2] [total: 9]",
            "16": "16 0620/23/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w14_qp_31.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib14 11_0620_31/2rp \u00a9 ucles 2014 *5421214333* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) october/november 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/31/o/n/14 \u00a9 ucles 20141 (a)  match the following ph values to the solutions given below. 1        3        7        10        13   the solutions all have the same concentration.  solution ph  aqueous ammonia, a weak base   dilute hydrochloric acid, a strong acid  aqueous sodium hydroxide, a strong base  aqueous sodium chloride, a salt  dilute ethanoic acid, a weak acid  [5]  (b)  explain why solutions of hydrochloric acid and ethanoic acid with the same concentration, in  mol  / dm3, have a different ph.   ... .   ... .   ... ...  [2]  (c)  measuring ph is one way of distinguishing between a strong acid and a weak acid.   describe another method.  method  ...    ... .  results  . ...   ... . [2] [total: 9]",
            "3": "3 0620/31/o/n/14 \u00a9 ucles 2014 [turn over2  two macromolecular forms of carbon are graphite and diamond. the structures of graphite and  diamond are given below. diamond graphite  (a)  explain in terms of its structure why graphite is soft and is a good conductor of electricity.   ... .   ... .   ... .   ... .   ... ...  [3]  (b)  state two uses of graphite which depend on the above properties.  it is soft  ..    ... .  it is a good conductor of electricity  ... .   ... . [2]  (c)  silicon( iv) oxide also has a macromolecular structure.  (i)  describe the macromolecular structure of silicon( iv) oxide.   .    . ..  [1]  (ii)  predict two physical properties which diamond and silicon( iv) oxide have in common.   .    . ..  [2] [total: 8]",
            "4": "4 0620/31/o/n/14 \u00a9 ucles 20143  the main use of sulfur dioxide is the manufacture of sulfuric acid.  (a)  state two other uses of sulfur dioxide.   ... .   ... ...  [2]  (b)  one source of sulfur dioxide is burning sulfur in air.   describe how sulfur dioxide can be made from the ore zinc sul \ufb01 de.   ... .   ... ...  [2]  (c)  the contact process changes sulfur dioxide into sulfur trioxide.  2so2(g)  +  o2(g)    2so3(g)  the forward reaction is exothermic temperature 400 to 450  \u00b0c  low pressure 1 to 10 atmospheres catalyst vanadium( v) oxide  (i)  what is the formula of vanadium( v) oxide?   . ..  [1]  (ii)  vanadium( v) oxide is an ef \ufb01 cient catalyst at any temperature in the range 400 to 450  \u00b0c.  scientists are looking for an alternative catalyst which is ef \ufb01 cient at 300  \u00b0c.   what would be the advantage of using a lower temperature?   .    .    . ..  [2]  (iii)  the process does not use a high pressure because of the extra expense.   suggest two advantages of using a high pressure?   explain your suggestions.   .    .    .    .    . ..  [4]",
            "5": "5 0620/31/o/n/14 \u00a9 ucles 2014 [turn over (d)  sulfuric acid is made by dissolving sulfur trioxide in concentrated sulfuric acid to form oleum.   water is reacted with oleum to form more sulfuric acid.   why is sulfur trioxide not reacted directly with water?   ... ...  [1] [total: 12]",
            "6": "6 0620/31/o/n/14 \u00a9 ucles 20144  iron is extracted from the ore hematite in the blast furnace. slag molten ironairfirebrick lining co forms co2 formswaste gases raw materials: coke, ciron ore, fe 2o3 limestone, caco3  (a)  the coke reacts with the oxygen in the air to form carbon dioxide. c  +  o2  \u2192  co2  (i)  explain why carbon monoxide is formed higher in the blast furnace.   .    . ..  [2]  (ii)  write an equation for the reduction of hematite, fe2o3, by carbon monoxide.   . ..  [2]  (b) (i)   limestone decomposes to form two products, one of which is calcium oxide.   name the other product.   . ..  [1]  (ii)  calcium oxide reacts with silicon( iv) oxide, an acidic impurity in the iron ore, to form slag.     write an equation for this reaction.   . ..  [2]  (iii)  explain why the molten iron and the molten slag form two layers and why molten iron is  the lower layer.   .    . ..  [2]  (iv)  suggest why the molten iron does not react with the air.   . ..  [1]",
            "7": "7 0620/31/o/n/14 \u00a9 ucles 2014 [turn over (c) iron and steel rust. iron is oxidised to hydrated iron( iii) oxide, fe2o3.2h2o, which is rust.  (i)  name the two substances which cause iron to rust.   . ..  [1]  (ii)  explain why an aluminium article coated with aluminium oxide is protected from further  corrosion but a steel article coated with rust continues to corrode.   .    . ..  [1]  (d) there are two electrochemical methods of rust prevention.  (i)  the \ufb01 rst method is sacri \ufb01 cial protection.   explain why the steel article does not rust. block of zincconnected electrically to steel pipesteel pipe   .    .    .    . ..  [4]   the second method is to make the steel article the cathode in a circuit for electrolysis. \u2013 +power inert anodesteel girder bubbles of hydrogen gassea-water  (ii)   mark on the diagram the direction of the electron \ufb02 ow. [1]  (iii)  the steel girder does not rust because it is the cathode. reduction takes place at the  cathode. give the equation for the reduction of hydrogen ions.   . ..  [2] [total: 19]",
            "8": "8 0620/31/o/n/14 \u00a9 ucles 20145  three common pollutants in the air are carbon monoxide, the oxides of nitrogen, no and no2, and  unburnt hydrocarbons. they are all emitted by motor vehicles.  (a)  describe how the oxides of nitrogen are formed.   ... .   ... ...  [2]  (b)  describe how a catalytic converter reduces the emission of these three pollutants.   ... .   ... .   ... .   ... .   ... ...  [4]  (c)  other atmospheric pollutants are lead compounds from leaded petrol.   explain why lead compounds are harmful.   ... .   ... ...  [1] [total: 7]",
            "9": "9 0620/31/o/n/14 \u00a9 ucles 2014 [turn over6  esters, polyesters and fats all contain the ester linkage.  (a)  esters can be made from alcohols and carboxylic acids. for example, the ester ethyl ethanoate  can be made by the following reaction. ch3cooh  +  ch3ch2oh  \u2192  ch3cooch2ch3  +  h2o  (i)  name the carboxylic acid and the alcohol from which the following ester could be made. ch2co och2 ch3ch3  name of carboxylic acid  . .  name of alcohol  . . [2]  (ii) 6.0  g of ethanoic acid, mr = 60, was reacted with 5.5  g of ethanol, mr = 46.   determine which is the limiting reagent and the maximum yield of ethyl ethanoate, mr = 88.  number of moles of ethanoic acid =  ..  [1]  number of moles of ethanol =  ...  [1] the limiting reagent is    [1]  number of moles of ethyl ethanoate formed =  ..  [1] maximum yield of ethyl ethanoate =  .  [1]  (b)  the following two monomers can form a polyester. hooc cooh ho oh   draw the structural formula of this polyester. include two ester linkages. [3]",
            "10": "10 0620/31/o/n/14 \u00a9 ucles 2014 (c)  fats and vegetable oils are esters. the formulae of two examples of natural esters are given  below. c17h33co2ch2 c17h33co2ch c17h33co2ch2 ester 1c17h35co2ch2 c17h35co2ch c17h35co2ch2 ester 2  (i)  one ester is saturated, the other is unsaturated.   describe a test to distinguish between them.  test   ..  result with unsaturated ester  ..  .   result with saturated ester  . .   .  [3]  (ii)  deduce which one of the above esters is unsaturated. give a reason for your choice.   .    .    . ..  [2]  (iii)  both esters are hydrolysed by boiling with aqueous sodium hydroxide.   what types of compound are formed?  ...  and   .. [2] [total: 17]",
            "11": "11 0620/31/o/n/14 \u00a9 ucles 2014 [turn over7  nitrogen can form ionic compounds with reactive metals and covalent compounds with non-metals.  (a)  nitrogen reacts with lithium to form the ionic compound lithium nitride, li3n.  (i)  write the equation for the reaction between lithium and nitrogen.   . ..  [2]  (ii)  lithium nitride is an ionic compound. draw a diagram which shows its formula, the charges  on the ions and the arrangement of the valency electrons around the negative ion.  use x for an electron from a lithium atom.  use o for an electron from a nitrogen atom. [2]  (b)  nitrogen \ufb02 uoride is a covalent compound.  (i)  draw a diagram showing the arrangement of the valency electrons in one molecule of the  covalent compound nitrogen tri \ufb02 uoride, nf3.  use x for an electron from a nitrogen atom.  use o for an electron from a \ufb02 uorine atom. [2]  (ii)  lithium nitride has a high melting point, 813  \u00b0c. nitrogen tri \ufb02 uoride has a low melting point,  \u2013207  \u00b0c.   explain why the melting points are different.   .    .    . ..  [2] [total: 8]",
            "12": "12 0620/31/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w14_qp_32.pdf": {
            "1": "this document consists of 13 printed pages and 3 blank pages. [turn overib14 11_0620_32/2rp \u00a9 ucles 2014 *1845295131* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) october/november 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/32/o/n/14 \u00a9 ucles 20141  an important aspect of chemistry is purity and methods of puri \ufb01 cation.  (a)  give an example of substances used in everyday life which must be pure.   ... ...  [1]  (b)  a list of techniques used to separate mixtures is given below. chromatography       crystallisation       diffusion       dissolving evaporation       \ufb01 ltration       fractional distillation       simple distillation  (i)  from the list, choose the most suitable technique to separate the following.  water from sea-water   ..  helium from a mixture of helium and methane  ...  ethanol from a mixture of ethanol and propanol  . iron \ufb01 lings from a mixture of iron \ufb01 lings and water  .  a mixture of two amino acids, glycine and alanine  . [5]  (ii)  describe how you would obtain a pure sample of copper( ii) sulfate-5-water crystals from  a mixture of copper( ii) sulfate-5-water with copper( ii) oxide using some of the techniques  listed above.   .    .    .    .    . ..  [4] [total: 10]",
            "3": "3 0620/32/o/n/14 \u00a9 ucles 2014 [turn over2  aluminium is obtained by the reduction of aluminium ions to aluminium atoms.  (a)  write an ionic equation for the reduction of an aluminium ion to an aluminium atom.   ... ...  [2]  (b)  the original method of extracting aluminium involved the reduction of aluminium chloride using  the reactive metal sodium. aluminium obtained by this method was very expensive due to the high cost of extracting sodium from sodium chloride.  (i)  complete the equation for this reduction. al  cl 3  +  ...na  \u2192  ...  +  ... [2]  (ii)  how can sodium metal be obtained from sodium chloride?   .    . ..  [2]  (c)  in the modern method, aluminium is obtained by the electrolysis of aluminium oxide (alumina)  dissolved in molten cryolite, na3al f6. carbon cathode (\u2013)carbon anode (+) mixture of aluminium oxide and cryolite molten aluminiumwaste gases, o2, co2, co, f2  (i)  the major ore of aluminium is impure aluminium oxide.   what is the name of this ore?   . ..  [1]  (ii)  this ore is a mixture of aluminium oxide, which is amphoteric, and iron( iii) oxide which is  basic.   explain how these two oxides can be separated by the addition of aqueous sodium  hydroxide.   .    .    . ..  [2]",
            "4": "4 0620/32/o/n/14 \u00a9 ucles 2014 (iii)  give two reasons why the electrolyte contains cryolite.   .    .    . ..  [2]  (iv) the mixture of gases evolved at the positive electrode includes:  carbon dioxide  carbon monoxide \ufb02 uorine  oxygen   explain the presence of these gases in the gaseous mixture formed at the positive  electrode. include at least one equation in your explanation.   .    .    .    .    . ..  [5]  (d)  a major use of aluminium is the manufacture of pots and pans. one reason for this is its  resistance to corrosion.  (i)  explain why aluminium, a reactive metal, is resistant to corrosion.   .    . ..  [1]  (ii)  suggest two other reasons why aluminium is suitable for making pots and pans.   .    . ..  [2] [total: 19]",
            "5": "5 0620/32/o/n/14 \u00a9 ucles 2014 [turn over3 (a)   a hydrocarbon has the following structural formula. cc cc hhhh hhhh  (i)  state the molecular formula and the empirical formula of this hydrocarbon.  molecular formula  ...   empirical formula  ... . [2]  (ii) draw the structural formula of an isomer of the above hydrocarbon. [1]  (iii) explain why these two hydrocarbons are isomers.   .    . ..  [2]  (iv)  are these two hydrocarbons members of the same homologous series?   give a reason for your choice.   .    . ..  [1]  (b)  alkenes can be made from alkanes by cracking.  (i)  explain the term cracking .   .    . ..  [2]  (ii)  one mole of an alkane, when cracked, produced one mole of hexane, c6h14, and two  moles of ethene.   what is the molecular formula of the original alkane?   . ..  [1]",
            "6": "6 0620/32/o/n/14 \u00a9 ucles 2014 (c)  alkenes are used in polymerisation reactions and addition reactions.  (i)  draw the structural formula of the product formed by the addition polymerisation of  but-2-ene. its formula is given below. cch ch3 h3ch [3]  (ii)  give the name and structural formula of the addition product formed from ethene and  bromine.  name   ...  structural formula [2] [total: 14]",
            "7": "7 0620/32/o/n/14 \u00a9 ucles 2014 [turn over4  zinc is an important metal. its uses include making alloys and the construction of dry cells (batteries).  (a)  name an alloy which contains zinc. what is the other metal in this alloy?  name of alloy  ... ..  other metal in alloy    [2]  (b)  the main ore of zinc is zinc blende, zns.  (i)  the ore is heated in the presence of air to form zinc oxide and sulfur dioxide.   write the equation for this reaction.   . ..  [2]  (ii)  give a major use of sulfur dioxide.   . ..  [1]  (c)  zinc can be obtained from zinc oxide in a two step process. aqueous zinc sulfate is made from  zinc oxide and then this solution is electrolysed with inert electrodes. the electrolysis is similar to that of copper( ii) sulfate with inert electrodes.  (i)  name the reagent which will react with zinc oxide to form zinc sulfate.   . ..  [1]  (ii)  complete the following for the electrolysis of aqueous zinc sulfate.   write the equation for the reaction at the negative electrode.   .    name the product at the positive electrode.   .    the electrolyte changes from zinc sulfate to   . [3]",
            "8": "8 0620/32/o/n/14 \u00a9 ucles 2014 (d)  a dry cell (battery) has a central rod, usually made of graphite. this is the positive electrode which  is surrounded by the electrolyte, typically a paste of ammonium chloride and manganese( iv)  oxide, all of which are in a zinc container which is the negative electrode. electrons flow when cell produces energywire graphite electrode zinc electrode electrolyte which is a paste of ammonium chloride and manganese( iv) oxide  (i)  draw an arrow on the diagram to indicate the direction of electron \ufb02 ow. [1]  (ii)  suggest why the electrolyte is a paste.    . ..  [1]  (iii)  the following changes occur in a dry cell.   for each change, decide if it is oxidation or reduction and give a reason for your choice.   zn to zn2+   .   manganese( iv) oxide to manganese( iii) oxide   .  [2] [total: 13]",
            "9": "9 0620/32/o/n/14 \u00a9 ucles 2014 [turn over5 (a)  glucose, sucrose and starch are all carbohydrates. their formulae are:  glucose, c6h12o6,  sucrose, c12h22o11,  starch, (c6h10o5)n.  (i)  identify two common features in the formulae of these carbohydrates.   .    . ..  [2]  (ii)  draw the structure of a complex carbohydrate, such as starch. the formula of glucose,  can be represented by ho oh   include three  glucose units in the structure. [2]  (b)  starch hydrolyses to glucose in the presence of the enzyme, amylase.   what is meant by the term enzyme ?   ... ...  [2]",
            "10": "10 0620/32/o/n/14 \u00a9 ucles 2014 (c)  the effect of temperature on this reaction can be studied by the experiment shown below.   starch and iodine form a blue-black colour.   glucose and iodine do not form a blue-black colour. teat pipette to add a few drops of iodine water at differenttemperatures aqueous starch andamylase (enzyme)   the experiment is set up as in the diagram and the time measured for the mixture to change  from blue-black to colourless. the experiment is repeated at different temperatures.   typical results of this experiment are given in the table below. experimenttemperature / \u00b0ctime  for blue-black colour to disappear / min a2 0 3 0 b4 0 1 5 c 70 remained blue-black  (i)  put the experiments in order of reaction rate \u2013 slowest \ufb01 rst and fastest last.   . ..  [2]  (ii)  explain why the reaction rates in experiments a and b are different.   .    .    .    . ..  [3]  (iii)  suggest why the colour remains blue-black in experiment c.   . ..  [1] [total: 12]",
            "11": "11 0620/32/o/n/14 \u00a9 ucles 2014 [turn over6  sulfuric acid is an important acid, both in the laboratory and in industry.   sulfuric acid is manufactured in the contact process. originally, it was made by heating metal  sulfates and by burning a mixture of sulfur and potassium nitrate.  (a)  give a major use of sulfuric acid.   ... ...  [1]  (b)  a group of naturally occurring minerals have the formula of the type feso4.xh2o where x is 1,  4, 5, 6 or 7. the most common of these minerals is iron( ii) sulfate-7-water.  (i)  when this mineral is heated gently it dehydrates. feso4.7h2o        feso4    +    7h2o  green pale yellow   describe how you could show that this reaction is reversible.   .    .    . ..  [2]  (ii) when the iron( ii) sulfate is heated strongly, further decomposition occurs. 2feso4(s)  \u2192  fe2o3(s)  +  so2(g)  +  so3(g)   the gases formed in this reaction react with water and oxygen to form sulfuric acid.   explain how the sulfuric acid is formed.   .    . ..  [2]  (iii)  a mineral of the type feso4.xh2o contains 37.2% of water.   complete the calculation to determine x.  mass of one mole of h2o = 18  g  mass of water in 100  g of feso4.xh2o = 37.2  g  number of moles of h2o in 100  g of feso4.xh2o = .  mass of feso4 in 100  g of feso4.xh2o = .  g  mass of one mole of feso4 = 152  g  number of moles of feso4 in 100  g of feso4.xh2o = .  x = . [4]",
            "12": "12 0620/32/o/n/14 \u00a9 ucles 2014 (c)  when a mixture of sulfur and potassium nitrate is burned and the products are dissolved in  water, sulfuric acid is formed.  (i)  the sulfuric acid formed by this method is not pure. it contains another acid.   deduce the identity of this acid.   . ..  [1]  (ii)  the heat causes some of the potassium nitrate to decompose.   write the equation for the action of heat on potassium nitrate.   . ..  [2] [total: 12]",
            "13": "13 0620/32/o/n/14 \u00a9 ucles 2014blank page",
            "14": "14 0620/32/o/n/14 \u00a9 ucles 2014blank page",
            "15": "15 0620/32/o/n/14 \u00a9 ucles 2014blank page",
            "16": "16 0620/32/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w14_qp_33.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib14 11_0620_33/rp \u00a9 ucles 2014 *8916450001* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) october/november 2014  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/33/o/n/14 \u00a9 ucles 20141  for each of the following elements give one physical property and one chemical property.  (a)  bromine (br2)  physical property  ...   chemical property  ... ... [2]  (b)  carbongraphite (c)  physical property  ...   chemical property  ... ... [2]  (c)  manganese (mn)  physical property  ...   chemical property  ... ... [2] [total: 6]",
            "3": "3 0620/33/o/n/14 \u00a9 ucles 2014 [turn over2  compound x is a colourless liquid at room temperature.  (a)  a sample of pure x was slowly heated from \u20135.0  \u00b0c, which is below its melting point, to 90  \u00b0c,  which is above its boiling point. its temperature is measured every minute and the results are represented on the graph. temperature timeab cd ef t \u00b0c90 \u00b0c \u20135 \u00b0c  (i)  complete the equation for the equilibrium present in the region bc.  x(s)       [1]  (ii)  what is the signi \ufb01 cance of temperature t  \u00b0c?   . ..  [1]  (iii)  what is the physical state of compound x in the region ef?   . ..  [1]  (iv)  what would be the difference in the region bc if an impure sample of x had been used?   . ..  [1]  (b)  compound x is a hydrocarbon. it contains 85.7% of carbon. the mass of one mole of x is 84  g.  (i)  what is the percentage of hydrogen in the compound ?   . ..  [1]  (ii)  calculate the empirical formula of x. show your working. empirical formula =   [3]  (iii)  what is the molecular formula of compound x?   . ..  [1] [total: 9]",
            "4": "4 0620/33/o/n/14 \u00a9 ucles 20143  in 1985 the fullerenes were discovered. they are solid forms of the element carbon. the structure  of the c60 fullerene is given below.  (a) (i)  in the c60 fullerene, how many other carbon atoms is each carbon atom bonded to?   . ..  [1]  (ii)   another fullerene has a relative molecular mass of 840.   how many carbon atoms are there in one molecule of this fullerene?   . ..  [1]  (b)  fullerenes are soluble in liquid hydrocarbons such as octane. the other solid forms of carbon  are insoluble.    describe how you could obtain crystals of fullerenes from soot which is a mixture of fullerenes  and other solid forms of carbon.   ... .   ... .   ... .   ... ...  [3]  (c)  a mixture of a fullerene and potassium is an excellent conductor of electricity.  (i)  which other form of solid carbon is a good conductor of electricity?   . ..  [1]  (ii)  explain why metals, such as potassium, are good conductors of electricity.   .    . ..  [2]  (iii)  the mixture of fullerene and potassium has to be stored out of contact with air. there are  substances in unpolluted air which will react with potassium.   name two potassium compounds which could be formed when potassium is exposed to  air.   . ..  [2] [total: 10]",
            "5": "5 0620/33/o/n/14 \u00a9 ucles 2014 [turn over4  a fuel cell produces electrical energy by the oxidation of a fuel by oxygen.   the fuel is usually hydrogen but methane and methanol are two other fuels which may be used.   a diagram of a hydrogen fuel cell is given below. cathodeanode ve\u2013 e\u2013h2 h2o o2  (a)  when the fuel is hydrogen, the only product is water.   what additional product would be formed if methane was used?   ... ...  [1]  (b)  write the equation for the chemical reaction that takes place in a hydrogen fuel cell.   ... ...  [1]  (c) (i)  at which electrode does oxidation occur? explain your choice.   . ..  [1]  (ii)  write an ionic equation for the reaction at this electrode.   . ..  [2]  (d)  fuel cells are used to propel cars.   give two advantages of a fuel cell over a gasoline-fuelled engine.   ... .   ... ...  [2] [total: 7]",
            "6": "6 0620/33/o/n/14 \u00a9 ucles 20145 (a)  sodium chlorate( i) decomposes to form sodium chloride and oxygen. the rate of this reaction  is very slow at room temperature provided the sodium chlorate( i) is stored in a dark bottle to  prevent exposure to light. 2nac l o  \u2192  2nac l  +  o2   the rate of this decomposition can be studied using the following experiment. sodium chlorate( i) solutionoxygen collects in syringe20 40 60 80 100   sodium chlorate( i) is placed in the \ufb02 ask and 0.2  g of copper( ii) oxide is added. this catalyses  the decomposition of the sodium chlorate( i) and the volume of oxygen collected is measured  every minute. the results are plotted to give a graph of the type shown below. volume of oxygen time00  (i)  explain why the gradient (slope) of this graph decreases with time.   .    . ..  [2]  (ii)  cobalt( ii) oxide is a more ef \ufb01 cient catalyst for this reaction than copper( ii) oxide.   sketch, on the grid, the graph for the reaction catalysed by cobalt( ii) oxide.   all other conditions were kept constant. [2]",
            "7": "7 0620/33/o/n/14 \u00a9 ucles 2014 [turn over (iii)  what can you deduce from the comment that sodium chlorate( i) has to be shielded from  light?   .    . ..  [1]  (iv)  explain, in terms of collisions between particles, why the initial gradient would be steeper  if the experiment was repeated at a higher temperature.   .    .    .    . ..  [3]  (b)  the ions present in aqueous sodium chloride are na+(aq), c l \u2013(aq), h+(aq) and oh\u2013(aq).   the electrolysis of concentrated aqueous sodium chloride forms three products. they are  hydrogen, chlorine and sodium hydroxide.  (i)  explain how these three  products are formed. give ionic equations for the reactions at the  electrodes.   .    .    .    .    . ..  [4]  (ii)  if the solution of the electrolyte is stirred, chlorine reacts with sodium hydroxide to form  sodium chlorate( i), sodium chloride and water.   write an equation for this reaction. cl 2  +  ...naoh  \u2192  .  +  .  +  . [2] [total: 14]",
            "8": "8 0620/33/o/n/14 \u00a9 ucles 20146  rubidium and strontium are very reactive metals at the top of the reactivity series. because their  ions have different charges, their compounds behave differently when heated.  (a)  the formulae of the ions of these two elements are rb+ and sr2+.   explain why these metals, which are in different groups, form ions which have different charges.   ... .   ... ...  [2]  (b)  strontium carbonate is similar to calcium carbonate. it is insoluble in water and it decomposes  when heated. rubidium carbonate is soluble in water and does not decompose when heated.  (i)  describe a method to prepare a pure sample of the insoluble salt, strontium carbonate, by  precipitation.   .    .    .    .    . ..  [4]  (ii)  complete the equation for the decomposition of strontium carbonate. srco3  \u2192    +   [1]  (c) metal nitrates decompose when heated.  (i)  rubidium nitrate decomposes as follows: 2rbno3  \u2192  2rbno2  +  o2   what is the name of the compound rbno2?   . ..  [1]  (ii)  the nitrates of most other metals decompose in a different way.   complete the equation for the decomposition of strontium nitrate. ...sr(no3)2  \u2192    +  4no2  +   [2] [total: 10]",
            "9": "9 0620/33/o/n/14 \u00a9 ucles 2014 [turn over7  butane is oxidised to a mixture of carboxylic acids by oxygen in the presence of a catalyst.   the acids formed are methanoic acid, ethanoic acid and propanoic acid \u2013 the \ufb01 rst three members  of the carboxylic acid homologous series.  (a) (i)   give the name and structural formula of the fourth member of this series.  name   ...  structural formula showing all the atoms and bonds [3]  (ii) state three  characteristics of a homologous series.   .    .    . ..  [3]  (iii)  all members of this series are weak acids.   what is meant by the term weak acid ?   .    .    . ..  [3]  (b)  carboxylic acids react with alcohols to form esters. ethanol reacts with ethanoic acid to form  the ester ethyl ethanoate, ch3cooch2ch3.  (i)  give the name and formula of the ester which is formed from methanol and propanoic  acid.  name   ...  formula  . ... [2]  (ii)  what is the name of the ester which has the formula ch3cooch3?   . ..  [1]",
            "10": "10 0620/33/o/n/14 \u00a9 ucles 2014 (c) (i)   complete the equation for the oxidation of butane to propanoic acid. 3c4h10  +  .o2  \u2192  4c2h5cooh  +  ...h2o [1]  (ii)  name another  compound which can be oxidised to propanoic acid.   . ..  [1] [total: 14]",
            "11": "11 0620/33/o/n/14 \u00a9 ucles 2014 [turn over8 (a)   describe how cobalt chloride paper can be used to test for the presence of water.   ... .   ... ...  [2]  (b)  complete the description of the preparation of crystals of the soluble salt, cobalt( ii) chloride-6-water, coc l 2.6h2o, from the insoluble base, cobalt( ii) carbonate. coco3(s)  +  2hc l (aq)  \u2192  coc l 2(aq)  +  co2(g)  +  h2o(l)   50  cm3 of dilute hydrochloric acid, concentration 2.2  mol  / dm3, was heated and cobalt( ii)  carbonate was added in small amounts until  .   ... .   ... .   ... .   ... .   ... ...  [4]  (c)  6.31  g of cobalt( ii) chloride-6-water crystals were obtained. calculate the percentage yield to  1 decimal place.  number of moles of hc l in 50  cm3 of acid, concentration 2.2  mol  / dm3 = ..  maximum number of moles of coc l 2.6h2o which could be formed = ..  mass of 1 mole of coc l 2.6h2o = 238  g  maximum yield of coc l 2.6h2o = ..  g  percentage yield = ..% [4] [total: 10]",
            "12": "12 0620/33/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w14_qp_51.pdf": {
            "1": "this document consists of 7 printed pages and 1 blank page. [turn overib14 11_0620_51/2rp \u00a9 ucles 2014 *3364232586* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test october/november 2014  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/51/o/n/14 \u00a9 ucles 20141  you are going to investigate the reaction between two different solutions of dilute hydrochloric acid,  a and b, and a solution of substance c which is an alkali.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   fill the burette with the solution a of dilute hydrochloric acid to the 0.0  cm3 mark. using a  measuring cylinder, pour 20  cm3 of solution c into the conical \ufb02 ask. add a few drops of methyl  orange to the \ufb02 ask.   add solution a to the \ufb02 ask, with shaking. continue to add solution a to the \ufb02 ask until the  mixture just changes colour. record the burette reading in the table and complete the table.   pour away the contents of the conical \ufb02 ask and rinse the \ufb02 ask with distilled water. \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]  (b)  experiment 2   empty the burette and rinse it \ufb01 rst with distilled water, and then with a little of solution b. fill the  burette with the solution b of dilute hydrochloric acid to the 0.0  cm3 mark.   repeat experiment 1 using solution b.   record the burette readings in the table and complete the table. \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]",
            "3": "3 0620/51/o/n/14 \u00a9 ucles 2014 [turn over (c) (i)   what colour change was observed when dilute hydrochloric acid was added to solution c?  from   to  . [1]  (ii)  why is methyl orange added to the \ufb02 ask?   . ..  [1]  (iii)  what type of chemical reaction takes place when hydrochloric acid reacts with alkaline  solutions?   . ..  [1]  (d) (i)   in which experiment was the greater volume of dilute hydrochloric acid used?   . ..  [1]  (ii)  compare the volumes of dilute hydrochloric acid used in experiments 1 and 2.   . ..  [1]  (iii)  suggest, in terms of the concentration of solutions a and b, an explanation for the  difference in volumes used.   .    .    . ..  [2]  (e)  if experiment 2 was repeated using 10 cm3 of solution c, what volume of dilute hydrochloric  acid would be used? explain your answer.   ... .   ... ...  [2]  (f)  give one advantage and one disadvantage of using a measuring cylinder for solution c.  advantage  ... ...  disadvantage   . [2]",
            "4": "4 0620/51/o/n/14 \u00a9 ucles 2014 (g)  describe a method other than titration, using a different  reactant, that could be used to  compare the concentrations of the two solutions of dilute hydrochloric acid, a and b.   ... .   ... .   ... .   ... .   ... .   ... ...  [4] [total: 21]",
            "5": "5 0620/51/o/n/14 \u00a9 ucles 2014 [turn over2  you are provided with solid d which is a salt.   carry out the following tests on solid d, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on the solid (a) (i)   describe the appearance of solid d.  (ii)   place about half of solid d into a test-tube.  heat the test-tube gently and then strongly.  leave to stand for two minutes .  [2] ... ... .  [2] tests on the aqueous solutionadd the rest of solid d to about 10 cm 3 of distilled  water in a boiling tube and shake to dissolve. divide  the solution into \ufb01 ve equal portions in separate test-tubes. (b) (i)   using a teat pipette, add several drops  of aqueous sodium hydroxide to the \ufb01 rst  portion of the solution.    now add excess aqueous sodium hydroxide to the mixture.  (ii)  using a teat pipette, add several drops of aqueous ammonia to the second portion of the solution. now add excess aqueous ammonia to the mixture..  [2] .  [1] ... .  [2]",
            "6": "6 0620/51/o/n/14 \u00a9 ucles 2014tests observations (c)  to the third portion of the solution, add about  1 cm3 of hydrogen peroxide solution. heat  the mixture to boiling. leave to stand for one minute. test any gases given off with a splint ... .  [3] (d)  to the fourth portion of the solution, add about  1  cm3 of dilute nitric acid and aqueous silver  nitrate. .  [1] (e)  to the \ufb01 fth portion of solution, add about 1 cm3  of dilute nitric acid and aqueous barium nitrate.  shake and leave to stand for one minute .  [2]  (f)  what does test (a)(ii)  tell you about solid d?   ... ...  [1]  (g)  what conclusions can you draw about the identity of solid d?   ... .   ... .   ... ...  [3] [total: 19]",
            "7": "7 0620/51/o/n/14 \u00a9 ucles 2014blank page",
            "8": "8 0620/51/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_w14_qp_52.pdf": {
            "1": "this document consists of 7 printed pages and 1 blank page. [turn overib14 11_0620_52/fp \u00a9 ucles 2014 *1244230503* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test october/november 2014  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/52/o/n/14 \u00a9 ucles 20141  you are going to investigate the reaction between two different solutions of dilute hydrochloric acid,  a and b, and a solution of substance c which is an alkali.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   fill the burette with the solution a of dilute hydrochloric acid to the 0.0  cm3 mark. using a  measuring cylinder, pour 20  cm3 of solution c into the conical \ufb02 ask. add a few drops of methyl  orange to the \ufb02 ask.   add solution a to the \ufb02 ask, with shaking. continue to add solution a to the \ufb02 ask until the  mixture just changes colour. record the burette reading in the table and complete the table.   pour away the contents of the conical \ufb02 ask and rinse the \ufb02 ask with distilled water. \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]  (b)  experiment 2   empty the burette and rinse it \ufb01 rst with distilled water, and then with a little of solution b. fill the  burette with the solution b of dilute hydrochloric acid to the 0.0  cm3 mark.   repeat experiment 1 using solution b.   record the burette readings in the table and complete the table. \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [3]",
            "3": "3 0620/52/o/n/14 \u00a9 ucles 2014 [turn over (c) (i)   what colour change was observed when dilute hydrochloric acid was added to solution c?  from   to  . [1]  (ii)  why is methyl orange added to the \ufb02 ask?   . ..  [1]  (iii)  what type of chemical reaction takes place when hydrochloric acid reacts with alkaline  solutions?   . ..  [1]  (d) (i)   in which experiment was the greater volume of dilute hydrochloric acid used?   . ..  [1]  (ii)  compare the volumes of dilute hydrochloric acid used in experiments 1 and 2.   . ..  [1]  (iii)  suggest, in terms of the concentration of solutions a and b, an explanation for the  difference in volumes used.   .    .    . ..  [2]  (e)  if experiment 2 was repeated using 10 cm3 of solution c, what volume of dilute hydrochloric  acid would be used? explain your answer.   ... .   ... ...  [2]  (f)  give one advantage and one disadvantage of using a measuring cylinder for solution c.  advantage  ... ...  disadvantage   . [2]",
            "4": "4 0620/52/o/n/14 \u00a9 ucles 2014 (g)  describe a method other than titration, using a different  reactant, that could be used to  compare the concentrations of the two solutions of dilute hydrochloric acid, a and b.   ... .   ... .   ... .   ... .   ... .   ... ...  [4] [total: 21]",
            "5": "5 0620/52/o/n/14 \u00a9 ucles 2014 [turn over2  you are provided with solid d which is a salt.   carry out the following tests on solid d, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on the solid (a) (i)   describe the appearance of solid d.  (ii)   place about half of solid d into a test-tube.  heat the test-tube gently and then strongly.  leave to stand for two minutes .  [2] ... ... .  [2] tests on the aqueous solutionadd the rest of solid d to about 10 cm 3 of distilled  water in a boiling tube and shake to dissolve. divide  the solution into \ufb01 ve equal portions in separate test-tubes. (b) (i)   using a teat pipette, add several drops  of aqueous sodium hydroxide to the \ufb01 rst  portion of the solution.    now add excess aqueous sodium hydroxide to the mixture.  (ii)  using a teat pipette, add several drops of aqueous ammonia to the second portion of the solution. now add excess aqueous ammonia to the mixture..  [2] .  [1] ... .  [2]",
            "6": "6 0620/52/o/n/14 \u00a9 ucles 2014tests observations (c)  to the third portion of the solution, add about  1 cm3 of hydrogen peroxide solution. heat  the mixture to boiling. leave to stand for one minute. test any gases given off with a splint ... .  [3] (d)  to the fourth portion of the solution, add about  1  cm3 of dilute nitric acid and aqueous silver  nitrate. .  [1] (e)  to the \ufb01 fth portion of solution, add about 1 cm3  of dilute nitric acid and aqueous barium nitrate.  shake and leave to stand for one minute .  [2]  (f)  what does test (a)(ii)  tell you about solid d?   ... ...  [1]  (g)  what conclusions can you draw about the identity of solid d?   ... .   ... .   ... ...  [3] [total: 19]",
            "7": "7 0620/52/o/n/14 \u00a9 ucles 2014blank page",
            "8": "8 0620/52/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_w14_qp_53.pdf": {
            "1": "this document consists of 7 printed pages and 1 blank page. [turn overib14 11_0620_53/2rp \u00a9 ucles 2014 *8578699418* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test october/november 2014  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/53/o/n/14 \u00a9 ucles 20141  you are going to investigate the addition of four different solids, h, j, k and l, to water.   the same mass of solid, 4  g, will be used in each experiment.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out \ufb01 ve experiments.  (a)  experiment 1   use a measuring cylinder to pour 25  cm3 of distilled water into the polystyrene cup provided.  support the polystyrene cup in the 250 cm3 beaker. measure the initial temperature of the  water and record it in the table below.   add all of solid h to the water in the cup and stir the mixture with the thermometer.   measure the temperature of the liquid mixture after 90 seconds. record your result in the table.   remove the thermometer and rinse the thermometer and the cup with water.  (b)  experiment 2   repeat experiment 1, using solid j instead of solid h.   measure and record the initial and \ufb01 nal temperatures in the table below.   keep  some of this solution in a test-tube for experiment 5.  (c)  experiment 3   repeat experiment 1, using solid k. record the temperatures in the table.  (d)  experiment 4   repeat experiment 1 using solid l. record the temperatures in the table and complete the  table. keep  this solution for experiment 5. experiment solidinitial temperature / \u00b0c\ufb01 nal temperature / \u00b0ctemperature difference  / \u00b0c 1 h 2 j 3 k 4 l [4]  (e)  experiment 5   pour about 3  cm3 of the solution from experiment 2 into a test-tube. use a teat pipette to add  about 3  cm3 of the solution from experiment 4 to the test-tube. record your observations.   ... .   ... ...  [2]",
            "3": "3 0620/53/o/n/14 \u00a9 ucles 2014 [turn over (f)   draw a labelled bar chart of the results for experiments 1, 2, 3 and 4 on the grid below. 0temperature difference  / \u00b0c experiment [4]   use your results and observations to answer the following questions.  (g) (i)  which experiment produced the smallest temperature change?   . ..  [1]  (ii)  which solids dissolve in water to produce an endothermic change? explain your choice.   .    . ..  [2]",
            "4": "4 0620/53/o/n/14 \u00a9 ucles 2014 (h)  suggest the temperature change that would occur if  (i)  experiment 3 was repeated using 50  cm3 of distilled water,   .    . ..  [1]  (ii)  2 g of solid l were used in experiment 4.   . ..  [1]  (iii)  explain your answer to (h)(ii) .   . ..  [1]  (i)  predict the temperature of the solution in experiment 2 after one hour. explain your answer.   ... .   ... ...  [2]  (j)  suggest an explanation for the observations in experiment 5.   ... .   ... .   ... ...  [2] [total: 20]",
            "5": "5 0620/53/o/n/14 \u00a9 ucles 2014 [turn over2  you are provided with two aqueous solutions, m and n.   carry out the following tests on m and n, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solution m divide solution m into four equal portions in separate  test-tubes. (a)  describe the appearance of solution m.   test the ph of the \ufb01 rst portion of m .  [1] (b)  add a spatula measure of calcium carbonate to  the second portion of m.   test the gas given off with a splint .  [2] (c)  to the third portion of m, add magnesium ribbon.   test the gas given off with a splint ... .  [3] (d)  to the fourth portion of m, add a few drops of  dilute nitric acid and about 1  cm3 of aqueous  silver nitrate .  [2]",
            "6": "6 0620/53/o/n/14 \u00a9 ucles 2014tests observations tests on solution n divide solution n into three equal portions in  separate test-tubes. (e)  describe the appearance of solution n.   test the ph of the \ufb01 rst portion of solution n..  [1] .  [1] (f)  use a teat pipette to add three to four drops of  aqueous zinc sulfate to the second portion of n. shake the mixture.   now add excess aqueous zinc sulfate to the  mixture and shake .  [3] (g)  to the third portion of n, add a spatula measure  of ammonium chloride. warm the mixture and test the gas given off with damp litmus paper .  [2]  (h) (i)  identify the gas given off in test (c).   . ..  [1]  (ii)  identify the gas given off in test (g).   . ..  [1]  (i)  identify solution m.   ... ...  [2]  (j)  what conclusion can you draw about solution n?   ... ...  [1] [total: 20]",
            "7": "7 0620/53/o/n/14 \u00a9 ucles 2014blank page",
            "8": "8 0620/53/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_w14_qp_61.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib14 11_0620_61/3rp \u00a9 ucles 2014 *9261581316* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical october/november 2014  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/61/o/n/14 \u00a9 ucles 20141  a student reacted dilute nitric acid with lead( ii) oxide to prepare lead( ii) nitrate. the diagram shows  the stages in the method used. dilute nitric acid15 0  cm3 of dilute nitric acid was measured into a beaker2 lead( ii) oxide was added untilall the nitric acidhad reacted 3 the mixture was separated4 the solution was allowed to coolheat solution oflead( ii) nitrate  (a)  complete the boxes to identify the pieces of apparatus. [2]  (b)  why is the dilute nitric acid heated?   ... ...  [1]  (c)  the lead( ii) oxide was weighed before and after the additions. 16171819 g before12131415 g after  use the balance diagrams to work out the mass of lead( ii) oxide added to the dilute nitric acid.   ... ...  [2]",
            "3": "3 0620/61/o/n/14 \u00a9 ucles 2014 [turn over (d) (i)   how would the student know when all of the dilute nitric acid had reacted in stage 2?   . ..  [1]  (ii)  what method is used to separate the mixture in stage 3?   . ..  [1]  (iii)  what term is used to describe the unreacted lead( ii) oxide?   . ..  [1]  (e)  describe the effect of heating the solution of lead( ii) nitrate until it boils and then heating for a  further ten minutes.   ... .   ... .   ... ...  [2] [total: 10]",
            "4": "4 0620/61/o/n/14 \u00a9 ucles 20142  two experiments were carried out to show what factors affect the rate of decomposition of hydrogen  peroxide, h2o2.   in each experiment the volume of gas produced was measured every minute for ten minutes.  experiment 1  the student used a mixture of 50  cm3 of hydrogen peroxide, 50  cm3 of water and 1 g of manganese( iv) oxide at a room temperature of 20  \u00b0c.  the results were plotted to obtain the graph shown.  experiment 2  the student repeated experiment 1 but did not record how much of each substance was used. the  points were plotted on the grid. 80 7060504030 20 10 0 012345 time  / minutes6789 1 0volume of gas  / cm3experiment 2 experiment 1",
            "5": "5 0620/61/o/n/14 \u00a9 ucles 2014 [turn over (a)   complete the graph for experiment 2. [1]  (b)  suggest the composition of the mixture used in experiment 2. explain your suggestion.  composition  . ..   ... .  explanation  . ...   ... ...  [4]  (c)  what is the function of the manganese( iv) oxide?   ... ...  [1]  (d)  sketch on the grid the curve that you would expect if experiment 1 was repeated at 10  \u00b0c. [2] [total: 8] 3  a student investigated the colours present in a fruit drink. the fruit drink was tested to check that  no arti \ufb01 cial colours had been added. the apparatus below was used. beakerglass cover solventpaper  (a) (i)   name the method used.   . ..  [1]  (ii)  why is there a glass cover on the beaker?   . ..  [1]  (b)  when should the paper be removed from the beaker?   ... ...  [1]",
            "6": "6 0620/61/o/n/14 \u00a9 ucles 2014 (c)  the diagram shows the results of the experiment. artificial colourscolours from fruit drinksolvent front  (i)  how many different coloured compounds were present in the fruit drink?   . ..  [1]  (ii)  are there any of the arti \ufb01 cial colours present in the fruit drink? explain your answer.   .    .    . ..  [2] [total: 6]",
            "7": "7 0620/61/o/n/14 \u00a9 ucles 2014 [turn over4  a student investigated the reaction between two different solutions of dilute hydrochloric acid, a  and b, and solution c which is alkaline.   two experiments were carried out.  (a)  experiment 1   a burette was \ufb01 lled with solution a of dilute hydrochloric acid to the 0.0  cm3 mark. using a  measuring cylinder, 20  cm3 of solution c was poured into a conical \ufb02 ask. a few drops of methyl  orange were added to the \ufb02 ask.   solution a was added to the \ufb02 ask, with shaking, until the mixture just changed colour.   use the burette diagram to record the burette reading in the table and complete the table. 24 2526 initial reading \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [2]  (b)  experiment 2   the burette was emptied and rinsed, \ufb01 rst with distilled water, and then with a little of solution b. the burette was \ufb01 lled with solution b of dilute hydrochloric acid to the 0.0  cm3 mark.   experiment 1 was repeated using solution b.   use the burette diagram to record the burette reading in the table and complete the table. 5 67 final reading \ufb01 nal burette reading  / cm3 initial burette reading  / cm3 difference  / cm3 [2]",
            "8": "8 0620/61/o/n/14 \u00a9 ucles 2014 (c) (i)   what type of chemical reaction takes place when hydrochloric acid reacts with alkaline  solutions?   . ..  [1]  (ii)  why is methyl orange added to the \ufb02 ask?   . ..  [1]  (d)  why was the burette rinsed, \ufb01 rst with distilled water and then with solution b, before starting  experiment 2?   ... .   ... .   ... ...  [2]  (e) (i)   in which experiment was the greater volume of dilute hydrochloric acid used?   . ..  [1]  (ii)  compare the volumes of dilute hydrochloric acid used in experiments 1 and 2.   . ..  [1]  (iii)  suggest, in terms of the concentration of solutions a and b, an explanation for the  difference in volumes used.   .    .    . ..  [2]  (f)  if experiment 2 was repeated using 10  cm3 of solution c, what volume of dilute hydrochloric  acid would be used? explain your answer.   ... .   ... ...  [2]  (g)  give one advantage and one disadvantage of using a measuring cylinder for solution c.  advantage  ... ...  disadvantage   ...  [2]",
            "9": "9 0620/61/o/n/14 \u00a9 ucles 2014 [turn over (h)  describe a method other than titration, using a different  reactant, that could be used to  compare the concentrations of the two solutions of dilute hydrochloric acid, a and b.   ... .   ... .   ... .   ... .   ... .   ... ...  [4] [total: 20]",
            "10": "10 0620/61/o/n/14 \u00a9 ucles 20145  a solid d, which is a soluble metal sulfate, was analysed.   the tests on d, and some of the observations, are in the following table.   complete the observations in the table. tests observations tests on solid d (a) (i)   appearance of solid d.  (ii)  solid d was heated in a  test-tube gently and then strongly.pale green crystals condensation formed at the top of the test-tube tests on the aqueous solution solid d was added to distilled water  and shaken to dissolve. the solution was divided into four equal portions in separate test-tubes. (b) (i)  several drops of aqueous  sodium hydroxide were added to the \ufb01 rst portion of the solution.    excess aqueous sodium  hydroxide was added to the mixture.  (ii)  excess aqueous ammonia was  added to the second portion of the solution.green precipitate green precipitate remained green precipitate (c)  aqueous silver nitrate and dilute  nitric acid were added to the third portion of the solution. ..   [1] (d)  aqueous barium nitrate and dilute  nitric acid were added to the fourth portion of the solution. ..   [2]",
            "11": "11 0620/61/o/n/14 \u00a9 ucles 2014 [turn over (e)   what does test (a) tell you about solid d?   ... ...  [2]  (f)  what conclusions can you draw about the identity of solid d?   ... .   ... ...  [3] [total: 8] 6 fizzy water   fizzy water contains carbon dioxide dissolved under pressure. when the water is heated, the gas  is given off.  (a) (i)   complete the labelled diagram to show how you could collect and measure the volume of  gas given off when \ufb01 zzy water is heated. heatfizzy water [2]  (ii)  state a test for carbon dioxide.   .    . ..  [2]",
            "12": "12 0620/61/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. (b)  a label on a bottle of \ufb01 zzy water stated that \u2018when evaporated completely the mass of solid  residue remaining is 200  mg  / dm3 of water\u2019.   plan an experiment to check the mass of solid formed when the \ufb01 zzy water is completely  evaporated. you are provided with a 500  cm3 bottle of \ufb01 zzy water. you can use the space below  to draw a diagram of the apparatus used if you wish.   ... .   ... .   ... .   ... .   ... ...  [4] [total: 8]"
        },
        "0620_w14_qp_62.pdf": {
            "1": "this document consists of 10 printed pages and 2 blank pages. [turn overib14 11_0620_62/2rp \u00a9 ucles 2014 *2703862241* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical october/november 2014  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/62/o/n/14 \u00a9 ucles 20141  ammonia gas can be prepared using the apparatus below. a mixture of two solids, ammonium  sulfate and calcium hydroxide, is heated. ammonium sulfate and calcium hydroxideammonia silica gel  (a) (i)   complete the boxes to identify the pieces of apparatus. [2]  (ii) show, by using an arrow, where heat is applied. [1]  (b)  why is the ammonia collected by upward delivery as shown, and not over water?   ... .   ... ...  [2]  (c)  a stopper from a bottle of concentrated hydrochloric acid was placed near the ammonia gas.   clouds of white smoke were seen. explain this observation.   ... .   ... .   ... ...  [3]  (d)  give a different test for ammonia gas.  test   .  result  ..  [2] [total: 10]",
            "3": "3 0620/62/o/n/14 \u00a9 ucles 2014 [turn over2  four bottles of liquids have lost their labels.   the liquids are known to be:  a solution of chlorine in water  dilute sulfuric acid hexene limewater   outline the chemical tests you could do to identify and distinguish between the liquids in each  bottle. liquid chemical test result a solution of chlorine in water dilute sulfuric acid hexene limewater [8] [total: 8]",
            "4": "4 0620/62/o/n/14 \u00a9 ucles 20143  a student prepared crystals of magnesium sulfate, mgso4.7h2o, from magnesium carbonate.   the procedure followed was in three steps.  step 1  some solid magnesium carbonate was transferred from a bottle into a beaker.  step 2  a dilute acid was slowly added to the beaker until all the magnesium carbonate had  reacted. magnesium sulfate solution was produced.  step 3  the solution was evaporated to crystallising point in an evaporating dish.  (a)  what should be used to transfer the magnesium carbonate in step 1?   ... ...  [1]  (b) (i)   name the acid used in step 2.   . ..  [1]  (ii)  why was the acid not heated in step 2?   . ..  [1]  (c) (i)   which reactant was in excess?   . ..  [1]  (ii)  suggest why this reactant should not have been in excess.   .    . ..  [1]  (d) (i)  how would the student know when the crystallisation point had been reached in step 3?   .    . ..  [1]  (ii)  suggest the effect of heating the magnesium sulfate crystals.   . ..  [1] [total: 7]",
            "5": "5 0620/62/o/n/14 \u00a9 ucles 2014 [turn over4  a student carried out an experiment to measure the temperature changes when aqueous sodium  hydroxide reacted with dilute hydrochloric acid.   one experiment was carried out.   using a measuring cylinder, 25  cm3 of the aqueous solution of sodium hydroxide was poured into a  polystyrene cup. the initial temperature of the solution was measured.   a burette was \ufb01 lled with dilute hydrochloric acid to the 0.0  cm3 mark.   10.0  cm3 of dilute hydrochloric acid was added to the aqueous sodium hydroxide in the cup and  the mixture stirred. the maximum temperature of the solution was measured. a further 10.0  cm3 of  dilute hydrochloric acid was added to the cup and the mixture stirred. the highest temperature of the mixture was measured.   further 10.0  cm3 portions of dilute hydrochloric acid were added to the cup, until a total volume of  60  cm3 of hydrochloric acid had been added. after each addition the mixture was stirred and the  highest temperature measured.  (a)  use the thermometer diagrams to record the temperatures measured in the table. 30 25 20volume of dilute hydrochloric acid added  / cm3thermometer diagramstemperature of solution in polystyrene cup  / \u00b0c 0.0 40 35 3010.0 50 45 4020.0 60 55 5030.0 60 55 5040.0 60 55 5050.0 55 50 4560.0  [3]",
            "6": "6 0620/62/o/n/14 \u00a9 ucles 2014 (b)  plot the results for the experiment on the grid. draw two straight lines through the points and  extend them until they cross. 60 5040302010 0 0.0 10.0 20.0 30.0 volume of dilute hydrochloric acid added  / cm3highest temperaturereached  / \u00b0c 40.0 50.0 60.0 [4]  (c) (i)   use your graph  to estimate the temperature of the reaction mixture when 25.0  cm3 of  dilute hydrochloric acid were added to 25  cm3 of aqueous sodium hydroxide.   show clearly on the grid  how you worked out your answer.   . ..  [2]  (ii)  what volume of dilute hydrochloric acid was needed to completely neutralise 25  cm3 of  aqueous sodium hydroxide?   show clearly on the grid  how you worked out your answer.   . ..  [3]",
            "7": "7 0620/62/o/n/14 \u00a9 ucles 2014 [turn over (d)  which reactant had the highest concentration? explain your answer.   ... .   ... ...  [2]  (e)  what type of chemical reaction, other than neutralisation, occurs when dilute hydrochloric acid  reacts with aqueous sodium hydroxide?   ... ...  [1]  (f)  predict the temperature of the mixture after two hours. explain your answer.   ... .   ... ...  [2]  (g)  suggest how the reliability of the results could be checked.   ... .   ... ...  [2] [total: 19]",
            "8": "8 0620/62/o/n/14 \u00a9 ucles 20145  two metallic salt solutions, a and b, were analysed. a was aqueous iron( iii) chloride.   the tests on the solutions and some of the observations are in the table.   complete the observations in the table. tests observations tests on solution a (a)  appearance of solution a. ..   [1] (b)  aqueous sodium hydroxide was  added to about 1  cm3 of solution a...   [2] (c)  aqueous ammonia was added to about 1  cm3 of solution a. ..   [1] (d)  dilute nitric acid and aqueous silver nitrate were added to about 1  cm3 of solution a. ..   [1] tests on solution b (e)  appearance of solution b. colourless liquid (f)  drops of aqueous sodium  hydroxide were added to solution b.   excess sodium hydroxide was then added to the mixture.white precipitate formed precipitate dissolved (g)  drops of aqueous ammonia were added to solution b.   excess ammonia was then added.white precipitate formed precipitate remained (h)  dilute nitric acid and aqueous barium nitrate were added to about 1 cm 3 of solution b.white precipitate formed",
            "9": "9 0620/62/o/n/14 \u00a9 ucles 2014 [turn over (i)  identify solution b?   ... .   ... ...  [2] [total: 7]",
            "10": "10 0620/62/o/n/14 \u00a9 ucles 20146 oven cleaners  (a)  some liquid oven cleaners contain particles of an insoluble solid, bentonite, suspended in an  aqueous solution.   outline an experiment to obtain a pure  sample of bentonite from the oven cleaner.   ... .   ... .   ... .   ... .   ... ...  [3]  (b)  oven cleaners contain an aqueous solution of sodium hydroxide.   plan an investigation to show which of two different oven cleaners, c and d, contains the  more concentrated solution of sodium hydroxide.   you are provided with common laboratory apparatus and chemicals.   ... .   ... .   ... .   ... .   ... .   ... .   ... .   ... .   ... .   ... ...  [6] [total: 9]",
            "11": "11 0620/62/o/n/14 \u00a9 ucles 2014blank page",
            "12": "12 0620/62/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.blank page"
        },
        "0620_w14_qp_63.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib14 11_0620_63/rp \u00a9 ucles 2014 *9232692217* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical october/november 2014  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/63/o/n/14 \u00a9 ucles 20141  sulfuric acid was added to sodium carbonate to prepare and collect a sample of carbon dioxide. sodium carbonatedilute sulfuric acid  (a)  complete and label the diagram to show how a sample of carbon dioxide should be collected. [2]  (b)  complete the box to identify the piece of apparatus used. [1]  (c)  suggest why it is not necessary to heat the reactants.   ... ...  [1]  (d)  give a test to identify carbon dioxide.  test   .  result  .. ..  [2] [total: 6]",
            "3": "3 0620/63/o/n/14 \u00a9 ucles 2014 [turn over2  a student investigated the rate of reaction between dilute nitric acid and marble chips (calcium  carbonate). the apparatus below was used. dilute nitric acidmarble chips   50  cm3 of dilute nitric acid, an excess, was poured into a beaker. the beaker was placed on a  balance and the marble chips added to the beaker. the apparatus was weighed immediately and a timer started. the mass of the beaker and contents was measured every minute for ten minutes.",
            "4": "4 0620/63/o/n/14 \u00a9 ucles 2014 (a)   use the balance diagrams to record the mass of the beaker and contents in the table.   complete the table to work out the total loss in mass of the beaker and contents. time  / minutes balance diagrammass of beaker and contents  / gtotal loss in mass  / g 0 93949596 g95.0 0.0 1 92939495 g 2 91929394 g 3 90919293 g 4 90919293 g 5 89909192 g 6 89909192 g 7 89909192 g 8 89909192 g 9 89909192 g 10 89909192 g [3]",
            "5": "5 0620/63/o/n/14 \u00a9 ucles 2014 [turn over (b)   plot the results on the grid and draw a smooth line graph. 5.0 4.03.02.01.00.0 0246 time  / minutestotal loss in mass  / g 81 0 [3]  (c)  why does the mass of the beaker and contents decrease?   ... ...  [1]  (d) (i)   which result appears to be inaccurate?   . ..  [1]  (ii)  use your graph to work out the loss in mass expected at that time.   . ..  [1]  (e)  sketch on the grid the graph you would expect if the experiment was repeated using the same  mass of smaller marble chips. [2] [total: 11]",
            "6": "6 0620/63/o/n/14 \u00a9 ucles 20143  electricity was used to break down an aqueous solution of copper chromate, cucro4, which is  green.   the apparatus used is shown. + \u2013aqueous copper chromateelectrodes   a brown deposit was seen forming at one electrode and oxygen was evolved at the other electrode.  (a)  suggest a suitable non-metal for the electrodes.   ... ...  [1]  (b)  give one other observation expected during this experiment.   ... ...  [1]  (c) name the brown deposit and identify at which electrode it is formed.   ... ...  [2]  (d)  name the process when electricity breaks down aqueous solutions.   ... ...  [1] [total: 5]",
            "7": "7 0620/63/o/n/14 \u00a9 ucles 2014 [turn over4  a student investigated the addition of four different solids, h, j, k and l, to water.   the same mass of solid, 4  g, was used in each experiment.   five experiments were carried out.  (a)  experiment 1   using a measuring cylinder, 25  cm3 of distilled water was poured into a polystyrene cup. the  initial temperature of the water was measured.   4 g of solid h was added to the water in the cup and the mixture stirred with a thermometer.   the temperature of the liquid mixture was measured after 90 seconds.   use the thermometer diagrams to record the results in the table below.   the thermometer and the cup were rinsed with water.  (b)  experiment 2   experiment 1 was repeated, using solid j instead of solid h.   use the thermometer diagrams to record the initial and \ufb01 nal temperatures in the table.   some of this solution was kept in a test-tube for experiment 5.  (c)  experiment 3  and experiment 4   experiment 1 was repeated, using solid k and then solid l.   use the thermometer diagrams to record the temperatures in the table. complete the table.   a little of the solution from experiment 4 was kept for experiment 5. experiment 1 2 325 20 15 25 20 15 25 20 15 25 20 1545 40 35 20 15 10 15 10 5 35 30 254thermometer diagraminitial temperature  / \u00b0cthermometer diagramfinal temperature  / \u00b0ctemperature difference  / \u00b0c [3]",
            "8": "8 0620/63/o/n/14 \u00a9 ucles 2014 (d)   experiment 5   a little of the solution from experiment 2 was poured into a test-tube. the solution from  experiment 4 was added to the test-tube. observations were noted. observation rapid effervescence  (e)  draw a labelled bar chart of the results for experiments 1, 2, 3 and 4 on the grid below. 0temperature difference  / \u00b0c [4]   use your results and observations to answer the following questions.  (f)  why were the thermometer and polystyrene cup rinsed after each experiment?   ... .   ... ...  [1]",
            "9": "9 0620/63/o/n/14 \u00a9 ucles 2014 [turn over (g) (i)   which experiment produced the smallest temperature change?   . ..  [1]  (ii)  which solids dissolve in water to produce an endothermic change? explain your choice.   .    . ..  [2]  (h)  suggest the temperature change that would occur if  (i) experiment 3 was repeated using 50  cm3 of distilled water,   .    . ..  [1]  (ii)  2 g of solid l were used in experiment 4.   . ..  [1]  (iii)  explain your answer to (h)(ii) .   . ..  [1]  (i)  predict the temperature of the solution in experiment 2 after one hour. explain your answer.   ... .   ... ...  [2]  (j)  suggest an explanation for the observations in experiment 5.   ... .   ... ...  [2]  (k)  suggest how the reliability of the results could be checked.   ... .   ... ...  [2] [total: 20]",
            "10": "10 0620/63/o/n/14 \u00a9 ucles 20145  two aqueous solutions, m and n, were analysed. solution n was aqueous sodium hydroxide.   the tests on m and n, and some of the observations are in the following table.   complete the observations in the table.  tests observations tests on solution m solution m was divided into four equal  portions in separate test-tubes. (a)  appearance of solution m.   the ph of the \ufb01 rst portion of m was  tested.colourless liquid ph 1 (b)  calcium carbonate was added to  the second portion of m.   the gas given off was tested with a splint.effervescence lighted splint extinguished (c)  magnesium ribbon was added to the third portion of m.   the gas given off was tested with a splint.effervescence lighted splint popped (d)  a few drops of dilute nitric acid and aqueous silver nitrate were added to the fourth portion of m. white precipitate",
            "11": "11 0620/63/o/n/14 \u00a9 ucles 2014 [turn overtests observations tests on solution n solution n was divided into three equal  portions in separate test-tubes. (e)  appearance of solution n.   the ph of the \ufb01 rst portion of  solution n was tested...   [1]  ph = [1] (f)  drops of aqueous zinc sulfate were  added to the second portion of n  and the mixture was shaken.   excess aqueous zinc sulfate was then added to the mixture and the mixture was shaken...  [1] ..   [2] (g)  ammonium chloride was added to  the third portion of n. the mixture  was warmed and the gas tested with damp red litmus paper. ..   [2]  (h) (i)  identify the gas given off in test (c).   . ..  [1]  (ii)  identify the gas given off in test (g).   . ..  [1]  (i)  identify solution m.   ... ...  [2] [total: 11]",
            "12": "12 0620/63/o/n/14 \u00a9 ucles 2014permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included the  publisher will be pleased to make amends at the earliest possible opportunity. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.6 indicators   indicators turn different colours in acidic and alkaline solutions. many plants contain substances  which are indicators. these coloured substances can be extracted from the plant material using water and these substances can then be used to test whether a solution is an acid or an alkali.   you are provided with two plant materials, blueberries and red cabbage leaves, and common laboratory apparatus and chemicals.  (a)  plan an investigation to extract the coloured substances from these plant materials.   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  plan an experiment to show if the coloured substances obtained in (a) are suitable to use as  indicators.   ... .   ... .   ... .   ... .   ... ...  [3] [total: 7]"
        }
    },
    "2015": {
        "0620_m15_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 15 printed pages and 1 blank page.  ib15 03_0620_12/2rp  \u00a9 ucles 2015 [turn over       *8505533334* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  february/march 2015       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2015 0620/12/f/m/15  1 a crystal of purple potassium manganate( vii) was added to each of the beakers shown in the  diagram.    hot water cold wate r crystal of potassium manganate( vii)    one beaker contained hot water and t he other beaker contained cold water.    in both beakers the purple colour of the potassium manganate( vii) spreads out.    which result and explanation are correct?     result explanation  a colour spreads faster in cold water particles move faster at a higher temperature  b colour spreads faster in cold water particles move slower at a higher temperature  c colour spreads faster in hot water particles move faster at a higher temperature  d colour spreads faster in hot water particles move slower at a higher temperature      2 during a reaction, the following changes take place.  1 the temperature rises.  2 a gas is given off.  which apparatus is required to measure the rate of this reaction?  a balance and burette  b balance and gas syringe  c gas syringe and burette  d gas syringe and stopclock     3 which statement about bonding is not correct?  a carbon can form four single covalent bonds.  b chlorine atoms react to gain a noble gas electronic structure.  c covalent bonding involves losing and gaining electrons.  d hydrogen molecules have the formula h 2.   ",
            "3": "3  \u00a9 ucles 2015 0620/12/f/m/15 [turn over  4 the table shows the numbers of particles present in the nuclei of four atoms or ions.     protons neutrons electronic structure  1 18 22 2,8,8  2 19 20 2,8,8  3 19 21 2,8,8,1  4 20 20 2,8,8,2    which two particles belong to the same element?  a 1 and 2 b 1 and 4 c 2 and 3 d 2 and 4      5 which substance is an ionic compound?     volatility electrical conductivity  when molten solubility in water  a high good soluble  b high poor insoluble  c low good soluble  d low poor insoluble    6 covalent bonds are formed when electrons are \u2026\u20261\u2026\u2026 .    most covalent compounds have \u2026\u20262\u2026\u2026 electrical conductivity.   which words correctly complete gaps 1 and 2?     1 2  a shared high  b shared low  c transferred high  d transferred low     7 which equation for the reaction between sodium carbonate and dilute hydrochloric acid is  correct?  a na 2co 3(s)  +  hc l (aq)  \u2192  nac l (aq)  +  co 2(g)  +  h 2o(i)  b na2co 3(s)  +  hc l (aq)  \u2192  na 2cl (aq)  +  co 2(g)  +  h 2o(i)  c na2co 3(s)  +  2hc l (aq)  \u2192  nac l (aq)  +  co 2(g)  +  h 2o(i)  d na2co 3(s)  +  2hc l (aq)  \u2192  2nac l (aq)  +  co 2(g)  +  h 2o(i)   ",
            "4": "4  \u00a9 ucles 2015 0620/12/f/m/15  8 the diagram shows an electrolysis experiment.    electrode p xelectrode q     during the electrolysis, sodium was formed at electrode p and chlorine at electrode q.    which row correctly identifies p, q and x?     p q x  a   anode   cathode   concentrated solution of  sodium chloride in water  b anode cathode molten sodium chloride  c   cathode   anode   concentrated solution of  sodium chloride in water  d cathode anode molten sodium chloride     9 the diagram shows apparatus for plating a spoon with silver.    spoon metal electrode electrolyte    which statement is not correct?  a silver would stick to the spoon because it is a very reactive metal.  b the electrolyte would be a silver salt dissolved in water.  c the metal electrode would be made from silver.  d the spoon would be connected to the negative terminal of the power supply.     ",
            "5": "5  \u00a9 ucles 2015 0620/12/f/m/15 [turn over  10 limestone can be changed into slaked lime in two chemical reactions.    1 when limestone, caco 3, is heated it decomposes into lime, cao.  2 water is slowly dripped onto the cooled lime. the lime appears to expand and  steam is produced. slaked lime, ca(oh) 2, is formed.    which row shows the correct description of each of the chemical reactions?     reaction 1 reaction 2  a endothermic endothermic  b endothermic exothermic  c exothermic endothermic  d exothermic exothermic      11 a student investigates the rate of reaction between marble chips and hydrochloric acid.    the mass of the reaction flask is measured.     the graph shows the results of two experiments, p and q.    0mass of reaction flask timep q     which change explains the difference between p and q?  a a catalyst is added in p.  b a higher temperature is used in p.  c bigger marble chips are used in q.  d hydrochloric acid is more concentrated in q.     ",
            "6": "6  \u00a9 ucles 2015 0620/12/f/m/15  12 hydrated cobalt( ii) chloride decomposes on heating.    the equation for the reaction is    coc l 2.6h 2o    coc l 2  +  6h 2o    the reaction is reversed by adding water.    which row describes the colour change and the type of reaction for the reverse  reaction?     colour change type of reaction  a blue to pink endothermic  b blue to pink exothermic  c pink to blue endothermic  d pink to blue exothermic      13 when copper is heated in air a black coating forms on the copper.   what happens to the copper in this reaction?  a the copper catches fire.  b the copper decomposes.  c the copper gains oxygen.  d the copper loses oxygen.     14 three chemicals, p, q and r, were each dissolved in water. the table shows some of the reactions of these solutions.    solution reaction when solid sodium  carbonate is added reaction when heated with  solid ammonium chloride  p gas evolved no reaction  q no reaction gas evolved  r no reaction no reaction    the ph of the three solutions was also measured.    what are the correct ph values of these solutions?     p q r  a 2 7 13  b 2 13 7  c 7 2 13  d 13 7 2 ",
            "7": "7  \u00a9 ucles 2015 0620/12/f/m/15 [turn over  15 the oxide of element x forms a solution with ph  4.    the oxide of element y forms a solution that turns universal indicator blue.    which row correctly classifies elements x and y?     element x element y  a metal metal  b metal non-metal  c non-metal metal  d non-metal non-metal      16 which two processes are involved in the preparation of magnesium sulfate from dilute sulfuric  acid and an excess of magnesium oxide?  a neutralisation and filtration  b neutralisation and oxidation  c thermal decomposition and filtration  d thermal decomposition and oxidation      17 which statement about aqueous sodium hydroxide is correct?  a when it is added to a solution containing sulfate ions, a white precipitate is formed.  b when it is added to a solution of copper( ii) ions, a blue precipitate is formed which dissolves  in excess to give deep blue solution.  c when it is added to a solution of iron( ii) ions, a green precipitate is formed which does not  dissolve in excess.  d when it is added to ammonium chloride, a gas is produced which turns blue litmus red.     18 which pair of elements will react together most violently?  a chlorine and lithium  b chlorine and potassium  c iodine and lithium  d iodine and potassium     ",
            "8": "8  \u00a9 ucles 2015 0620/12/f/m/15  19 the table shows some information about elements in group vii of the periodic table.    name state at room  temperature colour  chlorine gas yellow-green  bromine liquid brown  iodine ? ?  astatine solid black    which information about iodine completes the table?     state colour  a liquid black  b liquid green  c solid grey  d solid yellow     20 the diagram shows a section of the periodic table.    which element is described below?    \u2018a colourless, unreactive gas that is denser than air.\u2019    a b c d       21 which is not a characteristic property of transition metals?  a act as catalysts  b form coloured compounds  c high melting point  d low density     ",
            "9": "9  \u00a9 ucles 2015 0620/12/f/m/15 [turn over  22 which statement is correct for all metals?  a conduct electricity when molten  b gain electrons when they form ions  c have a low density  d have a low melting point      23 metal x lies between zinc and iron in the reactivity series.    which statements about metal x are correct?    1 it reacts with steam to produce hydrogen gas.  2 it does not react with steam but will produce hydrogen with dilute acid.  3 the metal can be obtained from its oxide by heating strongly with charcoal.  4 the metal oxide cannot be reduced using carbon.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      24 which of these gases is an atmospheric pollutant?    1 carbon monoxide  2 nitrogen dioxide  3 sulfur dioxide    a 1 only b 2 only c 3 only d 1, 2 and 3     25 molten iron from the blast furnace contains impurities.   the process of turning the impure iron into steel involves blowing oxygen into the molten iron and  adding calcium oxide.   what are the reasons for blowing in oxygen and adding calcium oxide?   blowing in oxygen adding calcium oxide  a carbon is removed by reacting with oxygen reacts with acidic impurities making slag  b carbon is removed by reacting with oxygen reacts with slag and so removes it  c iron reacts with the oxygen reacts with acidic impurities making slag  d iron reacts with the oxygen reacts with slag and so removes it     ",
            "10": "10  \u00a9 ucles 2015 0620/12/f/m/15  26 some properties of aluminium are listed.    1 it has mechanical strength.  2 it is resistant to corrosion.  3 it has a low density.  4 it conducts heat.    which three  properties make aluminium useful for making the bodies of aircraft?  a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4      27 the table describes three types of water.    water  type source of  water appearance before  treatment treatment appearance after  treatment  p river muddy none muddy  q river muddy filtration and chlorination clear  r well clear chlorination only clear    which statement is correct?  a only q and r are suitable for drinking, while p could be used for irrigation.  b only q and r are suitable for drinking, while p is unsuitable for any purpose.  c only q is suitable for drinking. r could be used for washing cars and p for irrigation.  d p, q and r are suitable for irrigation and washing cars, but are not suitable for drinking.      28 a sample of air from a town centre was analysed and found to contain mainly nitrogen and  oxygen, but also traces of the four gases below.    which of these gases is a pollutant?  a argon  b carbon dioxide  c sulfur dioxide  d water vapour     29 which elements does an npk fertiliser contain?  a nickel, phosphorus, potassium  b nickel, potassium, calcium  c nitrogen, phosphorus, potassium  d nitrogen, potassium, calcium   ",
            "11": "11  \u00a9 ucles 2015 0620/12/f/m/15 [turn over  30 the diagram shows experiments involving the rusting of iron.    water boiled to remove airwater anhydrous calciumchloride to dry the airoil iron nailstube q tube r tube p      the following results were suggested.  1 in tube p, the iron nails rust.  2 in tube q, the iron nails do not rust. 3 in tube r, the iron nails do not rust.   which results are correct?  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3      31 gas x is a waste gas from digestion in animals.    gas y is formed when gas x is burnt with a small amount of oxygen.    gas z is formed when gas x is burnt with an excess of oxygen.    what are x, y and z?     x y z  a carbon dioxide methane carbon monoxide  b carbon monoxide methane carbon dioxide  c methane carbon dioxide carbon monoxide  d methane carbon monoxide carbon dioxide    ",
            "12": "12  \u00a9 ucles 2015 0620/12/f/m/15  32 the list gives four experiments carried out with calcium carbonate.  1 acid added  2 alkali added  3 heated strongly  4 water added  which experiments produce carbon dioxide?  a 1 and 2 b 1 and 3 c 2 and 3 d 2 and 4      33 the diagram shows the soil ph range over which a vegetable grows well.    the ph of the soil to be used is 5.5.    5.0 6.0 7.0 8.0 9.0 ph vegetable grows well    why is lime added to the soil before planting the vegetable?  a the lime acts as a catalyst.  b the lime changes the soil acidity.  c the lime is an indicator.  d the lime supplies nitrogen.      34 the diagram shows the structure of a compound.    h ch c hh ch o hh ch     which functional groups does this molecule contain?     carboxylic  acid alkene alcohol  a no no no  b no yes yes  c yes no yes  d yes yes yes     ",
            "13": "13  \u00a9 ucles 2015 0620/12/f/m/15 [turn over  35 petroleum is separated into useful fractions by fractional distillation.   separation occurs in a fractionating column.   some properties of three of these fractions are shown.  fraction boiling point  range  / \u00b0c number of  carbon atoms in  the molecules  1  5\u201310  2 320\u2013350 16\u201324  3 120\u2013210      which statement is correct?  a fraction 1 has a higher boiling point range than fraction 2.  b fraction 2 is removed from a higher point in the fractioning tower than fraction 1.  c molecules in fraction 3 have shorter chains than those in fraction 2.  d none of the fractions is liquid at room temperature.      36 the structures of four molecules are shown.    c hh c hh4 c hh c h oh hh2 c hh c h h hh3 c hh c h c hhh ohh1      which molecules belong to the same homologous series?  a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4    37 which statement about alkanes is correct?  a ethane has one more carbon atom and one more hydrogen atom than methane.  b they are converted to alcohols by reaction with steam.  c they contain carbon-carbon double bonds.  d they form carbon dioxide and water on combustion.    ",
            "14": "14  \u00a9 ucles 2015 0620/12/f/m/15  38 which statement about alkenes is not correct?  a they are hydrocarbons.  b they are saturated.  c they contain a c=c bond.  d they form polymers.      39 ethene reacts with y to produce ethanol.    ethene + y \u2192 ethanol    what is y?  a hydrogen  b oxygen  c steam  d yeast      40 which description of ethanoic acid is correct?  a a clear, colourless and odourless liquid  b a colourless liquid with a distinctive odour  c a soft white solid with a distinctive odour  d a transparent solid with a low melting point    ",
            "15": "15  \u00a9 ucles 2015 0620/12/f/m/15  blank page",
            "16": "16    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    \u00a9 ucles 2015 0620/12/f/m/15   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_m15_qp_22.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 february/march 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 bla nk pages. [turn overib15 03_0620_22/3rp\u00a9 ucles 2015 *6533820761* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/22/f/m/15 \u00a9 ucles 20151  the diagram shows the structures of some substances containing carbon. abc defo c oh ch hhh c h ca2+co32\u2013co32\u2013co32\u2013co32\u2013co32\u2013 co32\u2013co32\u2013co32\u2013 ca2+ca2+ca2+ca2+ca2+ca2+ca2+ ccl clcl clc c hh hc hh h   answer the following questions about these substances.   each substance may be used once, more than once or not at all.  (a)  which substance, a, b, c, d, e or f  (i)  is a saturated hydrocarbon,    (ii)  has an ionic structure,  .. ..  (iii)  is a product of respiration,  . .  (iv)  is in the same homologous series as methane,  .  (v)  is used for cutting?  .  [5]  (b)  substance d is an element.   explain why substance d is an element.   ... ...  [1] [total: 6]",
            "3": "3 0620/22/f/m/15 \u00a9 ucles 2015 [turn over2  some properties of the halogens are shown in the table. halogenboiling point / \u00b0cstate at room temperature and pressure \ufb02 uorine \u2013188 chlorine \u201335 gasbromine +59 liquidiodine +184 solidastatine solid  (a)  use the information in the table to deduce  (i)  the boiling point of astatine,   . ..  [1]  (ii)  the state of \ufb02 uorine at room temperature and pressure.   . ..  [1]  (b)  when chlorine reacts with aqueous potassium iodide, the solution turns brown.  (i)  write a word equation for this reaction.   . ..  [2]  (ii)  explain why iodine does not react with aqueous potassium chloride.   .    . ..  [1]  (c)  when sodium reacts with iodine, energy is released.  (i)  what is the name given to a reaction which releases energy?   . ..  [1]  (ii)  explain what happens in terms of electron transfer when a sodium atom reacts with an  iodine atom.   .    . ..  [2] [total: 8]",
            "4": "4 0620/22/f/m/15 \u00a9 ucles 20153  the diagram shows a limestone column in an industrial town. limestone is largely calcium  carbonate. column when first built the same column after 40 yearsiron pins  (a)  describe and explain the changes to the column over 40 years.   in your answer refer to  \u2022  the change to the limestone,  \u2022  the name of a pollutant causing this change,  \u2022  the chemistry involved in this change.   ... .   ... .   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  the sections of the column are joined with iron pins which rust when exposed to the atmosphere.   describe two methods of rust prevention and explain how they prevent rusting.   ... .   ... .   ... .   ... ...  [3]",
            "5": "5 0620/22/f/m/15 \u00a9 ucles 2015 [turn over (c)  iron is a transition element.   give two properties of transition elements that make them different from non-transition metals  such as magnesium.   ... .   ... ...  [2]  (d)  an isotope of iron has 58 nucleons.  complete the table to show \u2022  the number of electrons and neutrons in this isotope of iron,  \u2022  the relative charges on each particle. particlenumber of each particle presentrelative charge on the particle electron neutron no chargeproton 26 [4]  (e)  iron reacts with hydrochloric acid to form iron( ii) chloride and a gas which \u2018pops\u2019 with a lighted  splint.   complete the symbol equation for this reaction. fe  +  ... hc l  \u2192  fec l 2  +   [2] [total: 15]",
            "6": "6 0620/22/f/m/15 \u00a9 ucles 20154  ammonium phosphate, (nh4)3po4, is a fertiliser.  (a)  which two elements in ammonium phosphate are important for plant growth?  . and  .  [1]   (b)  aqueous ammonium phosphate can be made in the laboratory by reacting aqueous ammonia  with aqueous phosphoric acid. aqueous phosphoric acid flaska aqueous ammonia  (i)  state the name of the piece of apparatus labelled a.   . ..  [1]  (ii)  suggest the ph value of aqueous phosphoric acid.   . ..  [1]  (iii)  describe how the ph of the mixture in the \ufb02 ask changes as the acid is added.   . ..  [1]  (iv)  which one of the following best describes the reaction of aqueous ammonia with aqueous  phosphoric acid?   put a ring around the correct answer. combustion           decomposition           neutralisation           reduction [1]  (c)  when sodium hydroxide is added to ammonium phosphate, ammonia is released.   complete the symbol equation for this reaction. (nh4)3po4  +  3naoh  \u2192  na3po4  +  ...nh3  +  3 ... [2] [total: 7]",
            "7": "7 0620/22/f/m/15 \u00a9 ucles 2015 [turn over5  the table shows the concentration of some ions present in a sample of seawater. name of ion formula of ionconcentration in g / dm3 bromide br \u20130.06 calcium ca2+0.30 chloride c l \u201320.00 i\u20130.04 magnesium mg2+1.00 potassium k+0.50 sodium na+11.00 sulfate so42\u20130.80  (a) (i)   which positive ion in the table has the lowest concentration?   . ..  [1]  (ii)  give the name of the ion with the formula i\u2013.   . ..  [1]  (iii)  which two ions in the table are formed from elements in group ii of the periodic table?   and   ...  [1]   (iv)  give the names of two ions in the table which move towards the anode (positive electrode)  when a sample of this seawater is electrolysed.   and   ...  [2] ",
            "8": "8 0620/22/f/m/15 \u00a9 ucles 2015 (b)  sodium chloride can be extracted from seawater.   concentrated aqueous sodium chloride is electrolysed using the apparatus shown. +\u2013 graphite anode concentrated aqueoussodium chloridegraphite cathodebattery  (i)  suggest why the anode and cathode are made of graphite.   . ..  [1]  (ii)  give the name of the product formed at the cathode (negative electrode).   . ..  [1]  (iii)  chlorine is formed at the anode.   complete the electronic structure of a chlorine molecule. show only the outer shell  electrons. cl cl [2]  (c)  molten magnesium bromide is electrolysed.   predict the products at the anode (positive electrode) and cathode (negative electrode).  anode  ... ..  cathode  . . [2] [total: 11]",
            "9": "9 0620/22/f/m/15 \u00a9 ucles 2015 [turn over6  zinc oxide is used for making baby soap and cream for treating sunburn.  (a)  suggest why the zinc oxide used for these purposes needs to be pure.   ... ...  [1]  (b)  zinc oxide can be reduced by carbon. carbon monoxide is one of the products.  (i)  what is the meaning of the term reduction ?   . ..  [1]  (ii)  write a word equation for the reaction of zinc oxide with carbon.   . ..  [1]  (iii)  explain why, in the laboratory, the reaction should be carried out in a fume cupboard.   . ..  [1]  (c)  the table shows how easy it is to reduce various metal oxides by heating with carbon. metal oxide ease of reduction with carbon lead oxide easily reduced at 300 \u00b0c magnesium oxide not reduced at 900 \u00b0c nickel oxide easily reduced at 500 \u00b0c zinc oxide fairly easily reduced at 900 \u00b0c   use the information in the table to put the metals in order of their reactivity. least reactive most reactive [2]  (d)  zinc oxide reacts with sulfuric acid.   complete the word equation for this reaction. zinc oxide  +  sulfuric acid  \u2192  zinc sulfate  +   [1]",
            "10": "10 0620/22/f/m/15 \u00a9 ucles 2015 (e)   pure dry crystals of zinc sulfate can be made by the reaction of dilute sulfuric acid with excess  zinc.  (i)  how is excess zinc removed from the reaction mixture?   . ..  [1]  (ii)  describe how you would obtain pure dry crystals of zinc sulfate from an aqueous solution  of zinc sulfate.   .    .    .    . ..  [3]  (iii)  zinc sulfate can be made from the reaction of sulfuric acid with zinc oxide or zinc.   give the name of another compound that reacts with sulfuric acid to produce zinc sulfate.   . ..  [1]  (f)  a student reacts zinc with excess sulfuric acid.   she obtains 16.1 g of zinc sulfate from 6.5 g of zinc.  (i)  calculate the mass of zinc sulfate she would obtain from 26.0 g of zinc. [1]  (ii)  calculate the relative formula mass of zinc sulfate, znso4. [2] [total: 15]",
            "11": "11 0620/22/f/m/15 \u00a9 ucles 2015 [turn over7  petroleum is separated into useful fractions by fractional distillation. kerosene fractiontgasoline fractionrefinery gasfractions fuel oil lubricating fraction petroleum bitumendiesel oil  (a) (i)   put an x on the diagram to show where the temperature in the column is the highest. [1]  (ii)  give the name of the fraction labelled t.   . ..  [1]  (iii)  the lubricating fraction is used to make lubricants.   give one other use of this fraction.   . ..  [1]  (b)  each fraction contains alkanes.   which two of the following statements are correct?   tick two boxes.   alkanes burn to form carbon dioxide and hydrogen.   ethene is an alkane with two carbon atoms.   alkanes polymerise to form poly(alkanes).   alkanes are generally unreactive apart from burning.   methane is an alkane present in natural gas. [2]",
            "12": "12 0620/22/f/m/15 \u00a9 ucles 2015 (c)  hydrogen can be made by cracking.  (i)  what is meant by the term cracking ?   .    . ..  [2]  (ii)  complete the equation for the cracking of propane. c3h8  \u2192    +  h2 [1]  (d)  ethanol is formed by the catalytic addition of steam to ethene.  (i)  complete the structures of ethene and ethanol in the equation below, showing all atoms  and bonds. + etheneh hc ethanolh hc ho hh [2]  (ii)  what does the symbol  mean?   . ..  [1] [total: 11]",
            "13": "13 0620/22/f/m/15 \u00a9 ucles 2015 [turn over8  a student placed a crystal of purple potassium manganate( vii) on a \ufb01 lter paper which had been  soaked in water.   after 5 minutes, a purple colour had spread out from the crystal.   after 30 minutes, the purple colour had spread further out. crystal of potassium manganate( vii) at the start after 5 minutes after 30 minuteswet filter paper  (a)  use the kinetic particle theory to explain these observations.   ... .   ... .   ... .   ... .   ... ...  [3]  (b)  describe the closeness and motion of the particles in a crystal of potassium manganate( vii).  closeness  ...   motion  .. .. [2]  (c)  mixtures of dyes can be separated by paper chromatography using the apparatus shown  below. base line   on the diagram above  \u2022  draw a line to show the solvent level at the beginning of the experiment,  \u2022  put a cross to show where the spot of dye mixture is placed at the beginning of the  experiment. [2] [total: 7]",
            "14": "14 0620/22/f/m/15 \u00a9 ucles 2015blank page",
            "15": "15 0620/22/f/m/15 \u00a9 ucles 2015blank page",
            "16": "16 0620/22/f/m/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_m15_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) february/march 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib15 03_0620_32/3rp\u00a9 ucles 2015 *3584316295* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/32/f/m/15 \u00a9 ucles 20151  for each of the following, give the name of an element from period 3 (sodium to argon), which  matches the description.  (a)  an element which is gaseous at room temperature and pressure   ... ...  [1]  (b)  an element that is added to water to kill bacteria   ... ...  [1]  (c)  an element that forms a basic oxide of the type xo   ... ...  [1]  (d)  an element used as an inert atmosphere in lamps   ... ...  [1]  (e)  an element that forms an amphoteric oxide   ... ...  [1]  (f)  an element that reacts vigorously with cold water to produce hydrogen   ... ...  [1] [total: 6] 2 (a)   de\ufb01 ne the term isotope .   ... .   ... ...  [2]  (b)  the table gives information about four particles, a, b, c and d.   complete the table.   the \ufb01 rst line has been done for you. particlenumber of protonsnumber of electronsnumber of neutronsnucleon numbersymbol or formula a 666 1 2 c b 11 10 12 c 88 o2\u2013 d 10 28 a l 3+ [7] [total: 9]",
            "3": "3 0620/32/f/m/15 \u00a9 ucles 2015 [turn over3  ammonia is manufactured by the haber process. nitrogen and hydrogen are passed over a catalyst  at a temperature of 450 \u00b0c and a pressure of 200 atmospheres.   the equation for the reaction is as follows. n2  +  3h2    2nh3   the forward reaction is exothermic.  (a)  state one use of ammonia.   ... ...  [1]  (b)  what is the meaning of the symbol ?   ... ...  [1]  (c)  what are the sources of nitrogen and hydrogen used in the haber process?  nitrogen  ... ...  hydrogen  ... . [2]  (d)  name the catalyst in the haber process.   ... ...  [1]  (e) (i)   if a temperature higher than 450 \u00b0c was used in the haber process, what would happen to  the rate of the reaction? give a reason for your answer.   .    .    . ..  [2]  (ii)  if a temperature higher than 450 \u00b0c was used in the haber process, what would happen to  the yield  of ammonia? give a reason for your answer.   .    .    . ..  [2]",
            "4": "4 0620/32/f/m/15 \u00a9 ucles 2015 (f) (i)   if a pressure higher than 200 atmospheres was used in the haber process, what would  happen to the yield  of ammonia? give a reason for your answer.   .    .    . ..  [2]  (ii)  explain why the rate of reaction would be faster if the pressure was greater than  200 atmospheres.   .    . ..  [1]  (iii)  suggest one reason why a pressure higher than 200 atmospheres is not used in the  haber process.   .    . ..  [1]  (g)  draw a dot-and-cross diagram to show the arrangement of the outer (valency) electrons in one  molecule of ammonia. [2]  (h)  ammonia acts as a base when it reacts with sulfuric acid.  (i)  what is a base?   . ..  [1]  (ii)  write a balanced equation for the reaction between ammonia and sulfuric acid.   . ..  [2] [total: 18]",
            "5": "5 0620/32/f/m/15 \u00a9 ucles 2015 [turn over4 (a)  a compound x contains 82.76% of carbon by mass and 17.24% of hydrogen by mass.  (i)  calculate the empirical formula of compound x. [2]  (ii)  compound x has a relative molecular mass of 58.   deduce the molecular formula of compound x. [2]  (b)  alkenes are unsaturated hydrocarbons.  (i)  state the general formula of alkenes.   . ..  [1]  (ii)  state the empirical formula of alkenes.   . ..  [1]  (c)  what is meant by the term unsaturated hydrocarbon ?  unsaturated   ... .   ... .  hydrocarbon   ...   ... . [2]",
            "6": "6 0620/32/f/m/15 \u00a9 ucles 2015 (d)  describe a test that would distinguish between saturated and unsaturated hydrocarbons.  reagent  . .  observation (saturated hydrocarbon)  .  observation (unsaturated hydrocarbon)  . [3]  (e)  addition polymers can be made from alkenes. the diagram shows part of an addition polymer. c hc2h5h c2h5h h h hc c c  (i)  draw a circle on the diagram to show one repeat unit in this polymer. [1]  (ii)  give the structure and the name of the monomer used to make this polymer.   structure   name  .   [2]  (iii)  give the structure of an isomer of the alkene in (e)(ii) . [1] [total: 15]",
            "7": "7 0620/32/f/m/15 \u00a9 ucles 2015 [turn over5  aluminium and iron are extracted from their ores by different methods.   aluminium is extracted from its puri \ufb01 ed oxide ore by electrolysis. cathode (negative electrode)oxygen given off at anode (positive electrode) aluminium oxide dissolved in molten cryolite aluminiumwaste gases  (a)  what is the name of the ore of aluminium which consists mainly of aluminium oxide?   ... ...  [1]  (b)  the electrodes are both made of the same substance.   name this substance.   ... ...  [1]  (c)  aluminium oxide is dissolved in molten cryolite before it is electrolysed.   give two reasons why aluminium oxide dissolved in molten cryolite is electrolysed rather than  molten aluminium oxide alone.   ... .   ... ...  [2]  (d)  write the ionic  equations for the reactions at the electrodes in this electrolysis.   anode (positive electrode)  ... ..  cathode (negative electrode)   . [2]",
            "8": "8 0620/32/f/m/15 \u00a9 ucles 2015 (e)  iron is extracted from its oxide ore by reduction using carbon in a blast furnace. slag molten ironair airwaste gases raw materials: coke,iron ore,limestone.  (i)  place the elements aluminium, carbon and iron in order of reactivity with the least  reactive  element \ufb01 rst.   . ..  [1]  (ii)  use your answer to (e)(i)  to explain why iron is extracted by reduction using carbon but  aluminium is not.   .    . ..  [1]  (f)  what is the name of the ore of iron which consists mainly of iron( iii) oxide?   ... ...  [1]  (g)  write balanced equations for the reactions occurring in the blast furnace which involve  (i)  the complete combustion of coke (carbon),   . ..  [1]  (ii)  the production of carbon monoxide from carbon dioxide,   . ..  [1]  (iii)  the reduction of iron( iii) oxide,   . ..  [1]  (iv)  the formation of slag.   . ..  [1] [total: 13]",
            "9": "9 0620/32/f/m/15 \u00a9 ucles 2015 [turn over6  a student is told to produce the maximum amount of copper from a mixture of copper and  copper( ii) carbonate.   the student adds the mixture to an excess of dilute sulfuric acid in a beaker and stirs the mixture  with a glass rod. the copper( ii) carbonate reacts with the sulfuric acid, forming a solution of  copper( ii) sulfate but the copper does not react with the sulfuric acid.   the student then  \u2022  removes the unreacted copper from the mixture,  \u2022  converts the solution of copper( ii) sulfate into copper by a series of reactions.  (a)  describe two things that the student would observe when the mixture is added to the dilute  sulfuric acid.   ... .   ... ...  [2]  (b)  describe how the student can produce pure dry copper from the mixture of copper and  copper( ii) sulfate solution.   ... .   ... .   ... .   ... ...  [3]  (c)  the student then adds sodium hydroxide solution to the copper( ii) sulfate solution to produce  copper( ii) hydroxide.  (i)  describe what the student would observe.   . ..  [1]  (ii)  write an ionic  equation for this reaction.   . ..  [1]  (d)  after separating the copper( ii) hydroxide from the mixture, the copper( ii) hydroxide is heated  strongly. the copper( ii) hydroxide decomposes into copper( ii) oxide and steam.  (i)  write an equation for the decomposition of copper( ii) hydroxide. include state symbols.   . ..  [2]  (ii)  name a non-metallic element that can be used to convert copper( ii) oxide into copper.   . ..  [1] [total: 10]",
            "10": "10 0620/32/f/m/15 \u00a9 ucles 20157  ethanol is manufactured from glucose, c6h12o6, by fermentation according to the following equation. c6h12o6  \u2192  2c2h5oh  +  2co2  (a)  state the conditions required for this reaction.   ... .   ... ...  [2]  (b)  in an experiment, 30.0 g of glucose was fermented.  (i)  calculate the number of moles of glucose in 30.0 g. . mol  [2]  (ii)  calculate the maximum mass of ethanol that could be obtained from 30.0 g of glucose. . g  [2]  (iii)  calculate the volume of carbon dioxide at room temperature and pressure that can be  obtained from 30.0 g of glucose. . dm3  [1]  (c)  ethanol can also be manufactured from ethene.  (i)  name the raw material which is the source of ethene.   . ..  [1]  (ii)  write a balanced equation for the manufacture of ethanol from ethene.   . ..  [1] [total: 9]",
            "11": "11 0620/32/f/m/15 \u00a9 ucles 2015blank page",
            "12": "12 0620/32/f/m/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_m15_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test february/march 2015  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib15 03_0620_52/3rp\u00a9 ucles 2015 *7312444178* for examiner\u2019s use total the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/52/f/m/15 \u00a9 ucles 2015blank page",
            "3": "3 0620/52/f/m/15 \u00a9 ucles 2015 [turn over1  you are going to investigate the solubility of salt d in water at various temperatures.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out four experiments.  (a)  experiment 1   you are provided with a clean boiling tube containing 4 g of salt d.   fill the burette provided with distilled water and add 10.0 cm3 of water to the boiling tube. heat  the mixture of salt d and water carefully  until all of the solid has dissolved.   remove the boiling tube from the heat and allow the solution to cool. stir the solution gently  with the thermometer.   note the temperature at which crystals \ufb01 rst appear  and record the temperature in the table at  the top of page 4 .   keep the boiling tube and its contents for the remaining three experiments in this  question.  (b)  experiment 2   from the burette, add a further 2.0 cm3 of water to the boiling tube and contents from  experiment 1.   heat the mixture to dissolve the crystals as before. find the temperature at which crystals \ufb01 rst  appear.   it will help if the boiling tube is dipped for short  periods of time in a beaker of cold water to  speed up the rate of cooling.   record, in the table, the total volume of water in the boiling tube and the temperature at which crystals \ufb01 rst appear.  (c)  experiment 3   from the burette, add a further 2.0 cm 3 of water to the boiling tube and contents from  experiment 2. repeat the experiment exactly as before.   record, in the table, the total volume of water in the boiling tube and the temperature at which crystals \ufb01 rst appear.",
            "4": "4 0620/52/f/m/15 \u00a9 ucles 2015 (d)  experiment 4   from the burette, add a further 4.0 cm3 of water to the boiling tube and contents from  experiment 3. repeat the experiment exactly as before.   note all the results in the table.   at the end of experiment 4, the total volume of water in the boiling tube will be 18.0 cm3. experiment numbertotal volume of water / cm3temperature at which crystals \ufb01 rst appear / \u00b0c 1 10.0 234 [5]    (e)  plot the results on the grid below and draw a smooth line graph. 8 10 12 14 16 total volume of water  / cm318 20 22temperature at which crystalsfirst appear  / \u00b0c [5]",
            "5": "5 0620/52/f/m/15 \u00a9 ucles 2015 [turn over (f)  from your graph , \ufb01 nd the temperature at which crystals of d would \ufb01 rst appear if the total  volume of water in the solution was 20.0 cm3.   show clearly on the grid  how you worked out your answer. .. \u00b0c  [2]  (g)   how did you know when salt d was completely dissolved in the water?   ... ...  [1]  (h)  the solubility of salt d at 100 \u00b0c is 57 g in 100 cm3 of water.   suggest, with a reason, the effect of using 8 g of salt d instead of 4 g in these experiments.   ... .   ... ...  [2]  (i)  salt c is less soluble in water than salt d.   sketch on the grid the graph you would expect for salt c. label this graph. [2]  (j)  describe and explain one improvement that could be made to the experimental method to  obtain more reliable results in this investigation.   improvement  ..    explanation  .. ..   ... .   ... ...  [2] [total: 19]   before moving on to question 2 , carefully place your solution of salt d, boiling tube, stopper  and thermometer into the container labelled waste for question 1 .",
            "6": "6 0620/52/f/m/15 \u00a9 ucles 20152  you are provided with two metal salt solutions, e and f.   carry out the following tests on e and f, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solution e (a)  describe the appearance of solution e.   [1] divide the solution into three equal portions in  separate test-tubes. (b)  to the \ufb01 rst portion of the solution, add a  few drops of dilute nitric acid and about 1 cm 3 of aqueous barium nitrate.   [2] (c)  to the second portion of the solution, add  excess aqueous sodium hydroxide and shake the mixture.   filter the mixture. gently warm the \ufb01 ltrate  and test the gas given off.   note how the residue on the \ufb01 lter paper  changes after \ufb01 ve minutes.  [1]  ..  [2]   [1] (d)  to the third portion of the solution, add  about 1 cm 3 of aqueous potassium  manganate( vii).   now add aqueous sodium hydroxide to the  mixture.  [1]   [2] tests on solution f (e) (i)  describe the appearance of solution f.  (ii) test the ph of solution f.  [1]   [1] (f)  add a few zinc granules to the solution f  provided in the boiling tube. shake the tube every minute.   note how the colour of the solution changes  over the next \ufb01 ve minutes. ..   [3]",
            "7": "7 0620/52/f/m/15 \u00a9 ucles 2015 [turn over (g)  what conclusions can you draw about solution e?   ... .   ... ...  [4]  (h)  what conclusions can you draw about solution f?   ... .   ... ...  [2] [total: 21]",
            "8": "8 0620/52/f/m/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_m15_qp_62.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib15 03_0620_62/3rp \u00a9 ucles 2015 *7492298954* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical february/march 2015  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/62/f/m/15 \u00a9 ucles 20151  a teacher separated a mixture of two liquids using the apparatus shown. the liquids were:  \u2022  ethanoic acid, boiling point 118 \u00b0c,  \u2022  chloroethanoic acid, boiling point 190 \u00b0c. heatcold water out cold water insmall glass beadsfractionating column mixture of liquids  (a)  complete the boxes to label the pieces of apparatus used. [2]  (b) (i)   which liquid would be collected \ufb01 rst? explain why.   .    . ..  [2]  (ii)  how would the teacher know when all of this liquid had been collected?   . ..  [1]  (c)  suggest why small glass beads are used in the fractionating column instead of large glass  beads.   ... .   ... ...  [1]  (d)  give a test to show that the liquids are acidic.  test   .  result  .. ..  [2] [total: 8]",
            "3": "3 0620/62/f/m/15 \u00a9 ucles 2015 [turn over2  the rate of reaction between excess calcium carbonate and dilute hydrochloric acid was investigated  using the apparatus shown below. the temperature of the hydrochloric acid was 25 \u00b0c. hydrochloric acid excess calcium carbonategas syringe   the volume of carbon dioxide evolved was measured every minute for six minutes.  (a)  use the gas syringe diagrams to complete the table of results. 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 30 40 50 60 80 90 7030 40 50 60 80 90 70 30 40 50 60 80 90 70 30 40 50 60 80 90 70time / minutes 0 123456gas syringe diagramtotal volume of carbon dioxide evolved  / cm3 [3]",
            "4": "4 0620/62/f/m/15 \u00a9 ucles 2015 (b)  plot the results on the grid below and draw a smooth line graph. 0 1 2 3 4 time  / minutes5 6volume of carbon dioxideevolved  / cm3100 80604020 0 [4]  (c) (i)   which point appears to be inaccurate? explain why.   .    . ..  [2]  (ii)  use your graph  to work out the volume of gas expected at that time. show clearly on the  grid how you worked out your answer.   . ..  [2]  (d)  sketch, on the grid , the graph you would expect if the experiment was repeated using  hydrochloric acid at a temperature of 50 \u00b0c. [2] [total: 13]",
            "5": "5 0620/62/f/m/15 \u00a9 ucles 2015 [turn over3  electricity was passed through concentrated hydrochloric acid using the apparatus shown. concentrated hydrochloric acid anduniversal indicator+\u2013battery negative electrodepositive electrode   effervescence was observed at both electrodes.  (a)  name this process used to break down concentrated hydrochloric acid.   ... ...  [1]  (b)  suggest why the electrodes are made of platinum and not aluminium.   ... ...  [1]  (c) (i)   name the gas given off at the positive electrode.   .   (ii)  what would be the colour of the universal indicator around the positive electrode at the  end of the experiment?   .  [2] [total: 4]",
            "6": "6 0620/62/f/m/15 \u00a9 ucles 20154  a student investigated the solubility of salt d in water at various temperatures.   four experiments were carried out.  (a)  experiment 1   4 g of salt d was added to a boiling tube. a burette was \ufb01 lled with distilled water and 10.0 cm3 of  water added to the boiling tube. the mixture of salt d and water was heated carefully until all of  the solid had dissolved. the boiling tube was removed from the heat and the solution allowed to cool. the solution was stirred gently with a thermometer.   the temperature at which crystals \ufb01 rst appeared was noted.   the boiling tube and its contents were kept for the remaining three experiments.  (b)  experiment 2   from the burette another 2.0 cm 3 of water was added to the boiling tube and contents from  experiment 1.   the mixture was heated to dissolve the crystals and allowed to cool as in experiment 1. the  temperature at which crystals \ufb01 rst appeared was noted.   record, in the table, the total volume of water in the boiling tube.  (c)  experiment 3   from the burette another 2.0 cm3 of water was added to the boiling tube and contents from  experiment 2. the experiment was repeated exactly as before.   record, in the table, the total volume of water in the boiling tube.",
            "7": "7 0620/62/f/m/15 \u00a9 ucles 2015 [turn over (d)  experiment 4   from the burette another 4.0 cm3 of water was added to the boiling tube and contents from  experiment 3. the experiment was repeated exactly as before.   record in the table the total volume of water in the boiling tube.   use the thermometer diagrams in the table to record the temperatures at which crystals \ufb01 rst  appeared in the four experiments. experiment numbertotal volume of water / cm3 thermometer diagramtemperature at which crystals \ufb01 rst appeared / \u00b0c 1 10.095 90 85 280 75 70 370 65 60 460 55 50 [3]",
            "8": "8 0620/62/f/m/15 \u00a9 ucles 2015 (e)   plot the results on the grid below and draw a smooth line graph. 8.0 10.0 12.0 14.0 16.0 total volume of water  / cm318.0 20.0temperature at which crystalsfirst appeared  / \u00b0c [5]  (f)  from your graph , \ufb01 nd the temperature at which crystals of d would \ufb01 rst appear if the total  volume of water in the solution was 20.0 cm3.   show clearly on the grid  how you worked out your answer.  ... [3]  (g)   how would the student know when salt d was completely dissolved in the water?   ... ...  [1]",
            "9": "9 0620/62/f/m/15 \u00a9 ucles 2015 [turn over (h)  the solubility of salt d at 100 \u00b0c is 57 g in 100 cm3 of water.   suggest, with a reason, the effect of using 8 g of salt d instead of 4 g in these experiments.   ... .   ... ...  [2]  (i)  salt c is less soluble in water than salt d.   sketch on the grid the graph you would expect for salt c. label this graph. [2]  (j)  describe and explain one improvement that could be made to the experimental method to  obtain more reliable results in this investigation.  improvement  . .  explanation  . ...   ... .   ... ...  [2] [total: 18]",
            "10": "10 0620/62/f/m/15 \u00a9 ucles 20155  two metal salt solutions, e and f, were analysed.   e was a mixture of iron( ii) sulfate and ammonium sulfate.   the tests on the solutions and some of the observations are in the following table.   complete the observations in the table. tests observations tests on solution e (a)  appearance of solution e.   [1] the solution was divided into three equal  portions in separate test-tubes. (b)  dilute nitric acid and aqueous barium  nitrate were added to the \ufb01 rst portion of the  solution.   [1] (c) (i)  excess aqueous sodium hydroxide  was added to the second portion of the solution.  (ii)  the mixture was \ufb01 ltered and the \ufb01 ltrate  heated.    the gas given off was tested with  damp litmus paper.  [2]  ..   [2] (d)  dilute sulfuric acid and aqueous potassium  manganate( vii), an oxidising agent, were  added to the third portion of the solution.   aqueous sodium hydroxide was then  added to the mixture.   [1] tests on solution f (e)  appearance of solution f. yellow liquid (f)  zinc powder was added to solution f.   the solution was observed for \ufb01 ve minutes.   the gas given off was tested with a splint.rapid effervescence turned blue, then green and \ufb01 nally light purple lighted splint popped",
            "11": "11 0620/62/f/m/15 \u00a9 ucles 2015 [turn over (g)  identify the gas given off in test (f).   ... ...  [1]  (h)  what conclusions can you draw about solution f?   ... .   ... ...  [2] [total: 10]",
            "12": "12 0620/62/f/m/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.6 rhubarb leaves   ethanedioic acid dihydrate, h2c2o4.2h2o, is a white crystalline solid. this acid is water-soluble and  is found in rhubarb leaves.   plan an investigation to obtain crystals of ethanedioic acid dihydrate from some rhubarb leaves.   you are provided with common laboratory apparatus, water and sand.   ...    ...    ...    ...    ...    ...    ...    ...    ... ..  [7] [total: 7]"
        },
        "0620_s15_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 16 printed pages.  ib15 06_0620_11/3rp  \u00a9 ucles 2015 [turn over       *4319041575* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  may/june 2015       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2015 0620/11/m/j/15  1 the changes that occur when a substance changes state are shown below.     w x  solid    liquid    gas   z y    which process, w, x, y or z, is occurring in the following four situations?    1 butter melts on a warm day.  2 water condenses on a cold surface. 3 the volume of liquid ethanol in an open beaker reduces.  4 ice forms inside a freezer.     1 2 3 4  a w x y z  b w y x z  c x y z w  d x z y w     2 a student uses the apparatus shown in the diagram below to measure the volume of carbon  dioxide gas made when different masses of marble chips are added to 25  cm3 of dilute  hydrochloric acid.    marble chipsbunggas syringe 25 cm3 dilute hydrochloric acid     which other items of apparatus are needed?   a funnel and balance  b funnel and stopwatch  c measuring cylinder and balance  d measuring cylinder and stopwatch    ",
            "3": "3  \u00a9 ucles 2015 0620/11/m/j/15 [turn over  3 atoms contain electrons, neutrons and protons.   what is the definition of nucleon number?  a the number of neutrons in the nucleus of an atom  b the number of protons in the nucleus of an atom  c the total number of neutrons and protons in the nucleus of an atom  d the total number of particles in an atom     4 the diagram shows the atomic structure of an element x.    pp p ppn n nnnee eeprotonkey eelectron nneutron     what is x?  a aluminium  b beryllium  c boron  d fluorine     5 which statements comparing the properties of electrons, neutrons and protons are correct?     neutrons and protons are  both heavier than electrons only electrons and  neutrons are charged  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "4": "4  \u00a9 ucles 2015 0620/11/m/j/15  6 rescuers are drilling through fallen rock in order to rescue some men trapped in a cave. the drill  needs lubricating from time to time.    the following statements were made about the materials used for the drill tip and the lubricant  and the reasons for their use.    1 diamond was used for the drill tip as it does not conduct electricity.  2 diamond was used for the drill tip as it is very hard.  3 graphite was used as the lubricant as it conducts electricity.  4 graphite was used as the lubricant as it is soft and flaky.    which statements are correct?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      7 in which compounds are pairs of electrons shared between atoms?    1 methane  2 lead bromide 3 sodium chloride    a 1 only b 2 only c 1 and 3 d 1, 2 and 3      8 what is the relative formula mass, m r, of caco 3?  a 50 b 68 c 100 d 204      9 copper and hydrogen can each be formed by electrolysis.    at which electrodes are these elements formed?     copper hydrogen  a anode anode  b anode cathode  c cathode anode  d cathode cathode     ",
            "5": "5  \u00a9 ucles 2015 0620/11/m/j/15 [turn over  10 the diagram shows a failed attempt to copper-plate a pan.    pan copper sulfate solutioncopper cathode3 v + \u2013     which action will plate the pan with copper?  a cooling the copper sulfate solution in an ice bath  b heating the copper sulfate solution to boiling point  c increasing the voltage from 3  v to 6  v  d making the pan the cathode and the copper the anode     ",
            "6": "6  \u00a9 ucles 2015 0620/11/m/j/15  11 the diagrams show four chemical reactions.    which reaction is endothermic?    ab cdaddition of water to calcium oxide combustion of natural gas thermal decomposition of limestone reaction of acid with alkaliwatersteam calcium oxidenatural gasflame final temperature initial temperature acidalkali heat      ",
            "7": "7  \u00a9 ucles 2015 0620/11/m/j/15 [turn over  12 powdered marble reacts with hydrochloric acid using the apparatus shown.    the gas syringe fills in 36 seconds.    powdered marblegas syringe gas hydrochloric acid     the experiment is repeated using marble chips in place of powdered marble.    how long does it take to fill the gas syringe in this experiment?  a 9 seconds  b 18 seconds  c 36 seconds  d 72 seconds      13 when pink crystals of cobalt( ii) chloride are heated, steam is given off and the colour of the solid  changes to blue.    coc l 2.6h 2o  coc l 2 + 6h 2o    what happens when water is added to the blue solid?     colour temperature  a changes to pink decreases  b changes to pink increases   c remains blue decreases   d remains blue increases     ",
            "8": "8  \u00a9 ucles 2015 0620/11/m/j/15  14 in which change is chromium( ii) oxide, cro, reduced?    crocro3 cr2o3cro2 crb da c      15 the table shows the ph of four aqueous solutions, w, x, y and z.    substance ph  w 7  x 9  y 2  z 5    universal indicator is added to each solution.    which row shows the colour of each solution after the indicator is added?     w x y z  a blue green orange red  b green blue red orange  c orange red blue green  d red orange green blue    16 hydrochloric acid is used to clean metals.    the acid reacts with the oxide layer on the surface of the metal, forming a salt and water.    which word describes the metal oxide?  a alloy  b base  c element  d indicator     ",
            "9": "9  \u00a9 ucles 2015 0620/11/m/j/15 [turn over  17 four steps to prepare a salt from an excess of a solid base and an acid are listed.  1 crystallisation  2 evaporation  3 filtration  4 neutralisation  in which order are the steps carried out?  a 2 \u2192 3 \u2192 4 \u2192 1  b 3 \u2192 1 \u2192 2 \u2192 4  c 4 \u2192 2 \u2192 1 \u2192 3  d 4 \u2192 3 \u2192 2 \u2192 1     18 which two compounds give a white precipitate when their aqueous solutions are mixed?  a silver nitrate and sodium chloride  b silver nitrate and sodium iodide  c sodium hydroxide and copper( ii) sulfate  d sodium hydroxide and iron( ii) chloride     19 which element is in the same group of the periodic table as lithium?   electrical conductivity density in g  / cm3  a high 0.97  b high 8.93  c low 0.07  d low 3.12     20 which properties of the element titanium, ti, can be predicted from its position in the periodic  table?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0013 \u0013 \u0013 \u0017  b \u0013 \u0013 \u0017 \u0013  c \u0013 \u0017 \u0013 \u0013  d \u0017 \u0013 \u0013 \u0013     ",
            "10": "10  \u00a9 ucles 2015 0620/11/m/j/15  21 the following statements are about elements in the periodic table.  1 their atoms have a full outer shell of electrons.  2 they form basic oxides.  3 they are found in group 0.  4 they are present in small quantities in the air.  which statements are correct for the noble gases?  a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4     22 in the outline of the periodic table below, some elements are shown as numbers.    651 72 4 3     which two numbers are  metals  in the same period?  a 1 and 2 b 1 and 7 c 3 and 5 d 5 and 6      23 solder is an alloy of lead and tin. it is used for joining pieces of metal.    metalheated solder molten solder     which statement about solder is correct?  a it can be represented by a chemical formula.  b it contains a mixture of lead and tin.  c it contains lead and tin chemically combined.  d it has a higher melting point than lead or tin.    ",
            "11": "11  \u00a9 ucles 2015 0620/11/m/j/15 [turn over  24 what is a major use of aluminium?  a making brass  b making cutlery  c making electrical wiring  d making food containers      25 which row describes the conditions used to make steel from the iron produced by a blast  furnace?     calcium oxide  (lime) oxygen heat  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017      26 w, x, y and z are four metals.    some properties of these metals are listed below.    1 only w and z can be extracted by reduction of their oxides with carbon.  2 only x will react with cold water.  3 only z can be found \u2018native\u2019 (not combined with any other element).    what is the correct order of these metals in the reactivity series (most reactive first)?  a x, w, y, z b x, y, w, z c z, w, y, x d z, y, w, x     27 the diagram shows stages in producing drinking water.    in which tank is chlorine added to the water?    reservoirsedimentation tankfiltration tankmains supplystorage tankanti-bacterial treatment tankab d c     28 which gas is not found in clean air?  a carbon dioxide  b carbon monoxide  c nitrogen  d oxygen ",
            "12": "12  \u00a9 ucles 2015 0620/11/m/j/15  29 which combination of chemical compounds could be used to produce the fertiliser shown?    supergrown     p     k 21 16 8::     a (nh 4)3po 4, kc l   b nh 4no 3, ca 3(po 4)2  c nh 4no 3, co(nh 2)2  d nh 4no 3, k 2so 4, (nh 4)2so 4      30 the pollutants released into the air from car exhausts and some power stations include oxides of  the type xo and yo 2.  what are x and y?   x y  a carbon only nitrogen only  b carbon only nitrogen and sulfur only  c carbon and nitrogen carbon and nitrogen only  d carbon and nitrogen carbon, nitrogen and sulfur     31 which statement about rusting is not correct?  a only oxygen is needed for rusting.  b painting can stop iron gates rusting.  c rust is hydrated iron( iii) oxide.  d water and oxygen are both needed for rusting.     32 carbon dioxide and methane are \u2018greenhouse gases\u2019 which contribute to global warming.    which process does not increase global warming?  a burning fossil fuels  b decay of organic waste  c farming cattle for beef  d growing crops such as sugar cane   ",
            "13": "13  \u00a9 ucles 2015 0620/11/m/j/15 [turn over  33 these statements are about a gas.    1 it is produced by thermal decomposition of a carbonate.  2 it is produced by the fermentation of glucose.  3 it makes up 1% of unpolluted air.  4 it is produced during the production of steel from iron.    which statements are correct for carbon dioxide?  a 1 and 2 only b 1, 2 and 3 c 1, 2 and 4 d 1, 3 and 4      34 the diagram represents a lime kiln.    air infuel in fuel in air in xwaste gases limestonelime kiln     what leaves the furnace at x?  a calcium carbonate  b calcium hydroxide  c calcium oxide  d calcium sulfate     ",
            "14": "14  \u00a9 ucles 2015 0620/11/m/j/15  35 the structures of four organic compounds are shown.    ch h hh ch c hh h hh ch hhhc ch c hh o h hh      which statement is not correct?  a only one of the compounds is an alcohol.  b only one of the compounds is an alkane.  c only one of the compounds is unsaturated.  d only three of the compounds are hydrocarbons.      36 which statement about petroleum is not correct?  a it can be separated into useful substances by fractional distillation.  b it consists mainly of hydrocarbons.  c it is found underground in many parts of the world.  d its main use is for making lubricants and polishes.    37 which statement about alkane molecules is correct?  a they burn in oxygen.  b they contain carbon, hydrogen and oxygen atoms.  c they contain double bonds.  d they contain ionic bonds.    38 which statements are correct for ethanoic acid?  1 it contains a carbon-oxygen double bond.  2 it contains two carbon atoms. 3 it decolourises bromine water.  4 it contains an \u2013oh group.  a 1 and 2 only  b 1 and 3  c 1, 2 and 4  d 2, 3 and 4     ",
            "15": "15  \u00a9 ucles 2015 0620/11/m/j/15  39 a hydrocarbon a is cracked to make b and hydrogen.    compound c is formed by the addition polymerisation of b.    to which homologous series do a, b and c belong?     alkene alkane  a a b and c  b b a and c  c c a and b  d \u2013 a and c      40 by which of the following methods is ethanol formed?  1 fractional distillation of petroleum  2 fermentation  3 catalytic addition of steam to ethene  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3     ",
            "16": "16    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    \u00a9 ucles 2015 0620/11/m/j/15   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s15_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 15 printed pages and 1 blank page.  ib15 06_0620_12/2rp  \u00a9 ucles 2015 [turn over       *8071151377* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  may/june 2015       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2015 0620/12/m/j/15  1 the diagram shows a sugar lump in a cup of tea.        which two processes must happen to spread the sugar evenly in the tea?     first process second process  a diffusion dissolving  b dissolving diffusion  c dissolving melting  d melting diffusion     2 the results of some tests on a colourless liquid x are shown.    \u007f boiling point = 102  \u00b0c  \u007f universal indicator turns green  what is x?  a ethanol  b hydrochloric acid  c pure water  d sodium chloride (salt) solution    3 the atomic structures of four particles are shown.    particle electrons neutrons protons  w 8  9 8  x 7  9 7  y 8 10 8  z 9 10 9    which two particles are isotopes?  a w and x b w and y c x and z d y and z     ",
            "3": "3  \u00a9 ucles 2015 0620/12/m/j/15 [turn over  4 q+ is an ion of element q.    what has the highest value in the ion?  a the nucleon number  b the number of electrons  c the number of neutrons  d the proton number     5 which statements comparing the properties of electrons, neutrons and protons are correct?     neutrons and protons are  both heavier than electrons only electrons and  neutrons are charged  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      6 graphite is a form of carbon.   why can graphite be used as a lubricant?  a graphite contains delocalised electrons which move throughout the structure.  b graphite contains weak covalent bonds so the atoms move easily.  c graphite has a low melting point so it easily turns into a liquid.  d graphite has weak forces of attraction between layers so they can move.    7 in which compounds are pairs of electrons shared between atoms?    1 methane  2 lead bromide  3 sodium chloride    a 1 only b 2 only c 1 and 3 d 1, 2 and 3     ",
            "4": "4  \u00a9 ucles 2015 0620/12/m/j/15  8 a molecule, z, contains two atoms of oxygen, six atoms of hydrogen and three atoms of carbon.    what is the formula of z?  a ch 3ch 2cho  b ch 3coch 3  c c 2h5co 2h  d c 3h6co 2h     9 copper and hydrogen can each be formed by electrolysis.    at which electrodes are these elements formed?     copper hydrogen  a anode anode  b anode cathode  c cathode anode  d cathode cathode    10 the diagram shows the electroplating of a steel object.    steel objectcopper copper( ii) sulfate solution+\u2013     a student made the following statements.    1 the object turns a reddish-brown colour.  2 the copper sulfate solution changes to a paler blue colour.  3 the copper electrode becomes smaller.    which statements are correct?    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "5": "5  \u00a9 ucles 2015 0620/12/m/j/15 [turn over  11 the elements hydrogen and uranium are used as fuels.   the compound ethanol is also used as a fuel.  which fuels require oxygen in order to produce heat energy?     hydrogen uranium ethanol  a \u0013 \u0013  \u0013  b \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0013      12 in which equation does the oxidation of the underlined compound occur?  a 2cuo   +  c  \u2192  co 2  +  cu  b fe2o3  +  3co  \u2192  2fe  +  3co 2  c 2mg  +  o 2  \u2192  2mgo  d mno 2  +  4hc l  \u2192  mnc l 2  +  2h 2o  +  c l 2      13 when pink crystals of cobalt( ii) chloride are heated, steam is given off and the colour of the solid  changes to blue.    coc l 2.6h 2o  coc l 2 + 6h 2o    what happens when water is added to the blue solid?     colour temperature  a changes to pink decreases  b changes to pink increases   c remains blue decreases   d remains blue increases     ",
            "6": "6  \u00a9 ucles 2015 0620/12/m/j/15  14 a simple way of making bread includes    1 mixing flour with a small amount of yeast and some water to make a \u2018dough\u2019.  2 leaving the dough in a warm place for the yeast to act on the dough to form carbon  dioxide which increases the volume of the dough.    which factors affecting a reaction rate are involved in bread making?     temperature use of an enzyme  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     15 which statement is not correct?  a when a base reacts with an ammonium salt, ammonia is given off.  b when an acid reacts with a base, neutralisation takes place.  c when an acid reacts with a carbonate, carbon dioxide is given off.  d when the acidity of a solution increases, the ph increases.    16 hydrochloric acid is used to clean metals.    the acid reacts with the oxide layer on the surface of the metal, forming a salt and water.    which word describes the metal oxide?  a alloy  b base  c element  d indicator     17 which method is used to make the salt copper sulfate?  a dilute acid  +  alkali  b dilute acid  +  carbonate  c dilute acid  +  metal  d dilute acid  +  non-metal oxide    ",
            "7": "7  \u00a9 ucles 2015 0620/12/m/j/15 [turn over  18 two tests are carried out to identify an aqueous solution of x.    test 1 aqueous sodium hydroxide is added and a blue precipitate is produced.  test 2 dilute nitric acid is added followed by aqueous silver nitrate and a white  precipitate is produced.    what is x?  a copper carbonate  b copper chloride  c iron( iii) carbonate  d iron( iii) chloride      19 the positions of four elements in the periodic table are shown.    which element does not form a compound with chlorine?    a bc d      20 which properties of the element titanium, ti, can be predicted from its position in the periodic  table?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0013 \u0013 \u0013 \u0017  b \u0013 \u0013 \u0017 \u0013  c \u0013 \u0017 \u0013 \u0013  d \u0017 \u0013 \u0013 \u0013    ",
            "8": "8  \u00a9 ucles 2015 0620/12/m/j/15  21 the table shows some properties of the group i metals.    metal melting point  / \u00b0c hardness reaction with water  lithium 181 moderately soft steady effervescence  sodium 98 soft vigorous effervescence  potassium 63 very soft very vigorous effervescence  rubidium ? ? ?    what are the properties of rubidium?  a melts below 63  \u00b0c, very soft, reacts explosively with water  b melts below 63  \u00b0c, very soft, reacts slowly with water  c melts above 181  \u00b0c, very soft, reacts explosively with water  d melts above 181  \u00b0c, very soft, reacts slowly with water      22 in the outline of the periodic table below, some elements are shown as numbers.    651 72 4 3     which two numbers are  metals  in the same period?  a 1 and 2 b 1 and 7 c 3 and 5 d 5 and 6     ",
            "9": "9  \u00a9 ucles 2015 0620/12/m/j/15 [turn over  23 which diagram represents an alloy?    a cb d      24 which statement is not correct?  a aluminium is used in food containers because of its resistance to corrosion.  b aluminium is used in the manufacture of aircraft because of its strength and low density.  c mild steel is used in car bodies because of its strength and low density.  d stainless steel is used in chemical plant because of its strength and resistance to corrosion.    25 which row describes the conditions used to make steel from the iron produced by a blast  furnace?     calcium oxide  (lime) oxygen heat  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017    ",
            "10": "10  \u00a9 ucles 2015 0620/12/m/j/15  26 samples of five different metals, e, f, g, h and j were reacted with dilute sulfuric acid using the  apparatus shown.    metalbunggas syringe dilute sulfuric acid     the volume of hydrogen gas collected after one minute was measured.  the results are shown on the bar chart.    efg metalhj25 201510 50volume of gas collected  / cm3     what is the order of reactivity of the metals (most reactive first)?  a e, f, g, h, j  b g, e, h, f, j  c j, f, h, e, g  d j, h, g, f, e     27 the diagram shows stages in producing drinking water.    in which tank is chlorine added to the water?    reservoirsedimentation tankfiltration tankmains supplystorage tankanti-bacterial treatment tankab d c    ",
            "11": "11  \u00a9 ucles 2015 0620/12/m/j/15 [turn over  28 which gas is not present in a sample of clean air?  a carbon dioxide  b chlorine  c oxygen  d water vapour      29 which combination of chemical compounds could be used to produce the fertiliser shown?    supergrown     p     k 21 16 8::     a (nh 4)3po 4, kc l   b nh 4no 3, ca 3(po 4)2  c nh 4no 3, co(nh 2)2  d nh 4no 3, k2so 4, (nh 4)2so 4     30 carbon monoxide is given out from the exhaust of vehicles that burn fossil fuels.   which row shows why carbon monoxide is a pollutant?   acidic toxic  a no no  b no yes  c yes no  d yes yes     31 a steel bicycle which had been left outdoors for several months was starting to rust.   what would not reduce the rate of corrosion?  a remove the rust and paint the bicycle.  b remove the rust and store the bicycle in a dry shed.  c remove the rust and wipe the bicycle with a clean damp cloth.  d remove the rust and wipe the bicycle with an oily cloth.     ",
            "12": "12  \u00a9 ucles 2015 0620/12/m/j/15  32 carbon dioxide and methane are \u2018greenhouse gases\u2019 which contribute to global warming.    which process does not increase global warming?  a burning fossil fuels  b decay of organic waste  c farming cattle for beef  d growing crops such as sugar cane     33 a zinc compound forms carbon dioxide in two different reactions.  1 it is heated strongly.  2 it is added to hydrochloric acid.   which type of reaction occurs in 1 and 2?   1 2  a combustion neutralisation  b combustion oxidation  c thermal decomposition neutralisation  d thermal decomposition oxidation      34 substance x is used to treat industrial waste.    industrial waste ph 4treated waste ph 7x      what is x and which type of reaction occurs during the treatment?   x type of reaction  a calcium oxide (lime) neutralisation  b calcium oxide (lime) redox  c carbon neutralisation  d carbon redox    ",
            "13": "13  \u00a9 ucles 2015 0620/12/m/j/15 [turn over  35 an organic compound has the molecular structure shown.    hc hh c hhhhhhc c o h     which type of organic compound is this?  a alcohol  b alkane  c alkene  d carboxylic acid      36 which statement about petroleum is not correct?  a it can be separated into useful substances by fractional distillation.  b it consists mainly of hydrocarbons.  c it is found underground in many parts of the world.  d its main use is for making lubricants and polishes.     37 the structures of four different organic compounds are shown.    h ch hhh ch h hoh co hh h co o h h      how many different homologous series are represented by these compounds?  a 1 b 2 c 3 d 4     ",
            "14": "14  \u00a9 ucles 2015 0620/12/m/j/15  38 the structure of a compound, y, is shown.    h ch ho co h     which row describes some of the physical properties of y?   colourless characteristic smell dissolves in water  a no no no  b no no yes  c yes yes no  d yes yes yes     39 a hydrocarbon a is cracked to make b and hydrogen.    compound c is formed by the addition polymerisation of b.    to which homologous series do a, b and c belong?     alkene alkane  a a b and c  b b a and c  c c a and b  d \u2013 a and c    40 which row correctly describes the production of ethanol and its properties?   can be made  from glucose can be made  from ethene is used as a  fuel is used as a  solvent  a \u0013 \u0013 \u0013 \u0013  b \u0013 \u0017 \u0013 \u0013  c \u0017 \u0013 \u0013 \u0017  d \u0017 \u0013 \u0017 \u0013   ",
            "15": "15  \u00a9 ucles 2015 0620/12/m/j/15  blank page            ",
            "16": "16    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    \u00a9 ucles 2015 0620/12/m/j/15   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements    "
        },
        "0620_s15_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 14 printed pages and 2 blank pages.  ib15 06_0620_13/4rp  \u00a9 ucles 2015 [turn over       *8479982220* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  may/june 2015       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2015 0620/13/m/j/15  1 a sugar cube is dropped into a hot cup of tea.    the tea is not stirred.    which statement explains why the tea becomes sweet?  a the heated water molecules penetrate the sugar cube.  b the hot tea causes the sugar to melt.  c the sugar cube dissolves and its molecules diffuse.  d the sugar molecules get hot and evaporate.      2 a blue solid, x, is soluble in water.    which method is used to obtain pure solid x from an aqueous solution?  a chromatography  b crystallisation  c filtration  d neutralisation     3 two atoms, x and y, can be represented as shown.    x41 20               y45 20    which statement is not correct?  a x and y are atoms of different elements.  b x and y are isotopes.  c x and y have different mass numbers.  d x and y have the same number of electrons.    4 two atoms have the same relative atomic mass but different chemical properties.    which row about the proton and neutron numbers of these atoms is correct?     proton numbers neutron numbers  a different different  b different same  c same different  d same same     ",
            "3": "3  \u00a9 ucles 2015 0620/13/m/j/15 [turn over  5 which statements comparing the properties of electrons, neutrons and protons are correct?     neutrons and protons are  both heavier than electrons only electrons and  neutrons are charged  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     6 diamond and graphite are both macromolecules.    which statement is not correct?  a diamond and graphite contain carbon atoms only.  b diamond and graphite contain charged ions.  c diamond and graphite have high melting points.  d the atoms in diamond and graphite are held together by covalent bonds.      7 in which compounds are pairs of electrons shared between atoms?    1 methane  2 lead bromide  3 sodium chloride    a 1 only b 2 only c 1 and 3 d 1, 2 and 3     8 aluminium oxide has the formula a l  2o3.     which statement about aluminium oxide is correct?  a 2 g of aluminium atoms are combined with 3  g of oxygen atoms.  b 2 g of aluminium atoms are combined with 3  g of oxygen molecules.  c aluminium oxide has a relative molecular mass of 102.  d pure aluminium oxide contains a higher mass of oxygen than of aluminium.     ",
            "4": "4  \u00a9 ucles 2015 0620/13/m/j/15  9 copper and hydrogen can each be formed by electrolysis.    at which electrodes are these elements formed?     copper hydrogen  a anode anode  b anode cathode  c cathode anode  d cathode cathode     10 an object is electroplated with silver using an aqueous silver salt as the electrolyte.    which set of conditions is used?     the object to be  electroplated is the the other electrode   is made from  a anode carbon  b anode silver  c cathode carbon  d cathode silver    11 which substance does not use oxygen to produce energy?  a coal  b hydrogen  c natural gas  d uranium     12 in which change is n 2o3 oxidised?    n2o3 n2o n2o4n2 nob dca      ",
            "5": "5  \u00a9 ucles 2015 0620/13/m/j/15 [turn over  13 when pink crystals of cobalt( ii) chloride are heated, steam is given off and the colour of the solid  changes to blue.    coc l 2.6h 2o  coc l 2 + 6h 2o    what happens when water is added to the blue solid?     colour temperature  a changes to pink decreases  b changes to pink increases   c remains blue decreases   d remains blue increases     14 the diagram shows an experiment to measure the rate of a chemical reaction.    dilute hydrochloric acid metalwatermeasuring cylinder      which change decreases the rate of reaction?  a adding water to the flask  b heating the flask during the reaction  c using more concentrated acid  d using powdered metal      15 which reaction is not characteristic of an acid?  a it dissolves magnesium oxide.  b it produces ammonia from ammonium compounds.  c it produces carbon dioxide from a carbonate.  d it produces hydrogen from zinc metal.    ",
            "6": "6  \u00a9 ucles 2015 0620/13/m/j/15  16 hydrochloric acid is used to clean metals.    the acid reacts with the oxide layer on the surface of the metal, forming a salt and water.    which word describes the metal oxide?  a alloy  b base  c element  d indicator      17 which of the following methods are suitable for preparing both zinc sulfate and copper sulfate?  1 reacting the metal oxide with warm dilute aqueous sulfuric acid.  2 reacting the metal with dilute aqueous sulfuric acid. 3 reacting the metal carbonate with dilute aqueous sulfuric acid.  a 1 and 2 only  b 1 and 3 only  c 2 and 3 only  d 1, 2 and 3      18 which gas relights a glowing splint?  a ammonia  b carbon dioxide  c hydrogen  d oxygen      19 the noble gases, which are in group 0 of the periodic table, are all very ...  1... .    ...  2..., one of these gases, is used to provide an inert atmosphere in lamps.    another, ...  3..., is used for filling balloons because it is less dense than air.    which words complete the sentences about noble gases?     1 2 3  a reactive argon helium  b reactive helium argon  c unreactive argon helium  d unreactive helium argon ",
            "7": "7  \u00a9 ucles 2015 0620/13/m/j/15 [turn over  20 which properties of the element titanium, ti, can be predicted from its position in the periodic  table?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0013 \u0013 \u0013 \u0017  b \u0013 \u0013 \u0017 \u0013  c \u0013 \u0017 \u0013 \u0013  d \u0017 \u0013 \u0013 \u0013     21 x is a group i metal.    y and z are group vii elements.    when x reacts with y a salt is formed. a solution of this salt reacts with z to form a different salt.    what are x, y and z?     x y z  a k cl 2 i2  b li cl 2 br2  c mg br 2 cl 2  d na i2 cl 2      22 in the outline of the periodic table below, some elements are shown as numbers.    651 72 4 3     which two numbers are  metals  in the same period?  a 1 and 2 b 1 and 7 c 3 and 5 d 5 and 6     ",
            "8": "8  \u00a9 ucles 2015 0620/13/m/j/15  23 the diagrams show the structure of two substances used to make electrical conductors.    xy     which statement correctly describes x and y?  a x is a pure metal and y is a compound.  b x is a pure metal and y is an alloy.  c x is a solid and y is a liquid.  d x is harder and stronger than y.     24 which statement about the uses of aluminium, mild steel and stainless steel is correct?  a aluminium is used for food containers as it has a high density.  b mild steel is used for car bodies as it is resistant to corrosion.  c stainless steel is used for aircraft bodies as it is strong.  d stainless steel is used for cutlery as it is resistant to corrosion.    25 which row describes the conditions used to make steel from the iron produced by a blast  furnace?     calcium oxide  (lime) oxygen heat  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017    ",
            "9": "9  \u00a9 ucles 2015 0620/13/m/j/15 [turn over  26 the statements describe how different metals react with cold water.    \u25cf calcium sinks, fizzing and releasing a steady stream of hydrogen.  \u25cf copper does not react.  \u25cf sodium floats, fizzing and rapidly releasing hydrogen.  \u25cf zinc does not react but does react with steam, releasing hydrogen.    using the information, where should hydrogen be placed in the reactivity series?  a below copper  b between sodium and calcium  c between calcium and zinc  d between zinc and copper      27 the diagram shows stages in producing drinking water.    in which tank is chlorine added to the water?    reservoirsedimentation tankfiltration tankmains supplystorage tankanti-bacterial treatment tankab d c       28 oxygen is a reactive element.   which row shows which of oxygen\u2019s reactions are useful?   fuel  combustion rusting steel  manufacture  a no no yes  b no yes no  c yes no yes  d yes yes no   ",
            "10": "10  \u00a9 ucles 2015 0620/13/m/j/15  29 which combination of chemical compounds could be used to produce the fertiliser shown?    supergrown     p     k 21 16 8::     a (nh 4)3po 4, kc l   b nh 4no 3, ca 3(po 4)2  c nh 4no 3, co(nh 2)2  d nh 4no 3, k2so 4, (nh 4)2so 4      30 below are two statements about sulfur dioxide.  1 sulfur dioxide is formed when fossil fuels burn and it is an acidic oxide.  2 sulfur dioxide is one of the gases in the air which is responsible for \u2018acid rain\u2019.   which is correct?  a both statements are correct and statement 1 explains statement 2.  b both statements are correct but statement 1 does not explain statement 2.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.      31 which method is not used for rust prevention?  a coating working parts of industrial machinery with oil  b covering wire for gardening use with plastic  c immersing gardening tools in water for storage  d painting car bodies    32 carbon dioxide and methane are \u2018greenhouse gases\u2019 which contribute to global warming.    which process does not increase global warming?  a burning fossil fuels  b decay of organic waste  c farming cattle for beef  d growing crops such as sugar cane ",
            "11": "11  \u00a9 ucles 2015 0620/13/m/j/15 [turn over  33 four reactions produce carbon dioxide.    1 respiration  2 fermentation  3 combustion of methane  4 manufacture of lime    which reactions do not use oxygen from the air?  a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      34 the diagram shows a kiln used to manufacture lime.    gas burners productair yx     which row identifies x and y?   x y  a lime carbon dioxide  b lime steam  c limestone carbon dioxide  d limestone steam     35 which statement about the names of organic compounds is correct?  a compounds containing c=c double bonds are alkanes.  b the compound of formula ch 3co 2h is methanoic acid.  c the compound of formula c 2h4 is ethane.  d the compound of formula c 2h5oh is an alcohol. ",
            "12": "12  \u00a9 ucles 2015 0620/13/m/j/15  36 which statement about petroleum is not correct?  a it can be separated into useful substances by fractional distillation.  b it consists mainly of hydrocarbons.  c it is found underground in many parts of the world.  d its main use is for making lubricants and polishes.      37 ethene, propene and butene are all members of the same homologous series.   which statement explains why ethene, propene and butene have similar chemical properties?  a they all have the same functional group.  b they are all gases at room temperature.  c they are all hydrocarbons.  d they are all organic.     38 which statement describes the compound shown below?    h cco oh h h    a it is a colourless flammable gas.  b it is a liquid which decolourises bromine water.  c it is a liquid with a characteristic smell.  d it is formed when ethane reacts with steam.      39 a hydrocarbon a is cracked to make b and hydrogen.    compound c is formed by the addition polymerisation of b.    to which homologous series do a, b and c belong?     alkene alkane  a a b and c  b b a and c  c c a and b  d \u2013 a and c    ",
            "13": "13  \u00a9 ucles 2015 0620/13/m/j/15  40 ethanol is manufactured from petroleum by reacting ethene with steam.    which statements about this process are correct?  1 ethene is obtained from the cracking of alkanes.  2 the process is carried out in the presence of yeast. 3 the reaction is an addition reaction. 4 the rate of reaction is increased by a catalyst.  a 1 and 3 only b 1 and 4 only c 1, 2 and 3 d 1, 3 and 4     ",
            "14": "14  \u00a9 ucles 2015 0620/13/m/j/15  blank page ",
            "15": "15  \u00a9 ucles 2015 0620/13/m/j/15  blank page",
            "16": "16    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    \u00a9 ucles 2015 0620/13/m/j/15   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_s15_qp_21.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/21   paper 2 may/june 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 16 printed pages . [turn overib15 06_0620_21/2rp\u00a9 ucles 2015 *1564763095* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/21/m/j/15 \u00a9 ucles 20151  the structures of six substances containing carbon are shown below. o cabc defo c ch hhhh ch hhh c h cc cccc c c ccccccc ccc cc cccc cc c ccc cc ccccc cccca2+co32\u2013co32\u2013co32\u2013co32\u2013co32\u2013 co32\u2013co32\u2013co32\u2013 ca2+ca2+ca2+ca2+ca2+ca2+ca2+ zn2+co32\u2013co32\u2013co32\u2013co32\u2013co32\u2013co32\u2013co32\u2013co32\u2013 zn2+zn2+zn2+zn2+zn2+zn2+zn2+   answer the following questions about these substances.   each substance may be used once, more than once or not at all.  (a)  which substance, a, b, c, d, e or f,  (i)  is an element, ..  [1]  (ii)  is a saturated hydrocarbon, ..  [1]  (iii)  is added to the blast furnace to help in the extraction of iron, ..  [1]  (iv)  has a giant covalent structure, ..  [1]  (v)  is a product of respiration, ..  [1]  (vi)  contains a metal ion with 20 protons? ..  [1]  (b)  complete the word equation for the thermal decomposition of substance b. ...heat calcium oxide + ... [2]  (c)  describe a test for substance a.  test   .  result  ..  [2] [total: 10]",
            "3": "3 0620/21/m/j/15 \u00a9 ucles 2015 [turn over2  a small piece of sodium is added to some ethanol. the temperature was measured before and after  the sodium was added. ethanol19 \u00b0c 29 \u00b0c sodium  (a)  explain how this experiment shows that the reaction is exothermic.   ... ...  [1]  (b)  complete the structure of ethanol to show all atoms and bonds. h ch h [1]",
            "4": "4 0620/21/m/j/15 \u00a9 ucles 2015 (c)  ethanol can be made by the reaction of steam with ethene.  (i)  write the word equation for this reaction.   . ..  [1]  (ii)  what conditions are needed for this reaction?  tick two boxes.  enzyme catalyst high temperature (300 \u00b0c)  low temperature (10 \u00b0c)  phosphoric acid catalyst presence of light [2]  (iii)  what will be observed when ethene is bubbled through aqueous bromine?   . ..  [1]  (d)  ethanol can also be made by fermentation.   the fermentation mixture contains solids as well as an aqueous solution of ethanol.   suggest how the ethanol can be puri \ufb01 ed from this fermentation mixture.   ... .   ... .   ... .   ... ...  [3] [total: 9]",
            "5": "5 0620/21/m/j/15 \u00a9 ucles 2015 [turn over3  the diagram shows the apparatus used for the electrolysis of molten sodium bromide. +\u2013r su t  (a) (i)   what does the term electrolysis  mean?   .    . ..  [1]  (ii)  which letter, r, s, t or u, in the diagram above represents the cathode?  ..   [1] (b)  complete the word equation for the electrolysis of molten sodium bromide. sodium bromide  \u2192  ..  +  .. [2]  (c)  a solution of sodium bromide in water is neutral.   which one of the following ph values is neutral?   put a ring around the correct answer. ph 0               ph 6               ph 7               ph 10               ph 14 [1]",
            "6": "6 0620/21/m/j/15 \u00a9 ucles 2015 (d)  the diagram below shows the arrangement of the particles in sodium bromide at room  temperature. na+br \u2013na+ na+br \u2013br \u2013na+br \u2013 na+br \u2013na+br \u2013p  (i)  give the name of the type of particles, p, present in sodium bromide.   . ..  [1]  (ii)  what is the state of sodium bromide at room temperature?   use the information in the diagram to explain your answer.   .    .    . ..  [2]  (e)  sodium bromide can be made by heating sodium in bromine vapour.   complete the balanced symbol equation for this reaction. ... na  +  ...  \u2192  2nabr [2]  (f)  bromine has two naturally-occurring isotopes.   what is the meaning of the term isotope ?   ... .   ... ...  [1] [total: 11]",
            "7": "7 0620/21/m/j/15 \u00a9 ucles 2015 [turn over4  a student investigated the reaction of magnesium with dilute hydrochloric acid. mg(s)  +  2hc l (aq)  \u2192  mgc l 2(aq)  +  h2(g)   she measured the volume of gas given off at various times during the reaction.  (a)  complete the diagram of the apparatus she would use to measure the volume of the gas given  off.   label the apparatus. flask hydrochloric acid magnesium ribbon [3]",
            "8": "8 0620/21/m/j/15 \u00a9 ucles 2015 (b)  the student carried out the reaction at 25 \u00b0c using magnesium ribbon.   her results are shown below. 60 5040302010 0 02 0 4 0 6 0 time  / seconds80 100 120 140volume of gas  / cm3  (i)  how long does it take for the reaction to stop? . seconds  [1]  (ii)  what is the volume of hydrogen made after 20 seconds? . cm3  [1]  (iii)  on the grid above, draw a line to show how the volume of gas changes when the experiment  is carried out at 15 \u00b0c and all other conditions remain the same. [2]  (iv)  the student repeated the experiment using magnesium powder. all other conditions  remain the same.   how does the rate of reaction with magnesium powder compare with the rate of reaction  with magnesium ribbon?   . ..  [1]",
            "9": "9 0620/21/m/j/15 \u00a9 ucles 2015 [turn over (c) (i)   draw a diagram to show the electron arrangement in a molecule of hydrogen. [1]  (ii)  what type of bonding is present in a hydrogen molecule?   . ..  [1]  (d)  magnesium chloride is a salt.   magnesium sulfate is also a salt.   give the name of two compounds  which react together to form magnesium sulfate.  ..  and  . ..  [2] [total: 12]",
            "10": "10 0620/21/m/j/15 \u00a9 ucles 20155  the structure of glycolic acid is shown below. ch co o hh ho  (a)  on the structure above, put a ring around the carboxylic acid functional group. [1]  (b)  glycolic acid is prepared by heating a mixture of methanal, carbon monoxide and water with a  sulfuric acid catalyst.  (i)  the formula of methanal is hcho.   calculate the relative molecular mass of methanal. [1]  (ii)  what is the function of the catalyst?   . ..  [1]  (iii)  state one adverse effect of carbon monoxide on humans.   . ..  [1]  (c)  glycolic acid can also be prepared by the reduction of oxalic acid.  (i)  what does the term reduction  mean?   . ..  [1]  (ii)  give the name of the reducing agent in the following reaction.  heat 2cuo(s)  +  c(s)  \u2192  2cu(s)  +  co2(g)  name of reducing agent    [1]",
            "11": "11 0620/21/m/j/15 \u00a9 ucles 2015 [turn over (d)  glycolic acid is found in unripe grapes.   grape skins contain a number of different coloured pigments.   describe how you could obtain a solution of these pigments from grape skins.   ... .   ... .   ... .   ... ...  [3]  (e)  glycolic acid can undergo polymerisation.   ethene can also undergo polymerisation.   the equation for the polymerisation of ethene is shown below.  catalyst ethene        poly(ethene)  high temperature   give the name of the monomer in this equation.   ... ...  [1]  (f)  long chain alkanes can be cracked to produce shorter chain alkanes and alkenes.  (i)  what conditions are needed for cracking?   .    . ..  [2]  (ii)  complete the equation for the cracking of hexadecane, c16h34, to form octane, c8h18, and  ethene only. c16h34  \u2192  c8h18  +  .. c2h4 [1] [total: 13]",
            "12": "12 0620/21/m/j/15 \u00a9 ucles 20156  the table shows some physical properties of the metals, a, b, c and d. metalelectrical conductivitydensity in g / cm3boiling point / \u00b0chardness a fairly good 8.64 765 hard b good 0.97 883 soft c good 7.14 907 hard d good 0.86 760 soft  (a) (i)   which two metals in the table are group i metals?   give a reason for your answer.   .    . ..  [2]  (ii)  none of the metals a, b, c or d are transition elements.   give two properties of transition elements or their compounds that make them different  from metals a, b, c and d.   .    . ..  [2]  (iii)  cobalt is a transition element.   when it is heated very strongly in steam, hydrogen is given off.   complete the symbol equation for this reaction. .. co(s)  +  4h2o(g)  \u2192  co3o4(s)  +  .. h2(g) [2]  (iv)  iron is also a transition element.   describe how iron is converted to steel.   in your answer, refer to basic oxides and oxygen.   .    .    .    . ..  [3]",
            "13": "13 0620/21/m/j/15 \u00a9 ucles 2015 [turn over (b)  when lithium reacts with water it moves about on the surface of the water, bubbles are seen  and the lithium disappears slowly.   predict how the reaction of potassium with water compares with the reaction of lithium with  water.   in your answer, include  \u2022  any differences in observations,  \u2022  the names of the products formed when lithium and potassium react with water.   ... .   ... .   ... .   ... .   ... .   ... .   ... ...  [5] [total: 14]",
            "14": "14 0620/21/m/j/15 \u00a9 ucles 20157 (a)   a student took two identical syringes.   he \ufb01 lled one with water and the other with helium gas and sealed the end of both syringes.   he then pushed the syringe plungers with equal force.   the diagram shows what happened. syringesyringe plunger water helium   describe and explain these results using ideas about particles in liquids and gases.   ... .   ... .   ... .   ... .   ... .   ... .   ... ...  [4]",
            "15": "15 0620/21/m/j/15 \u00a9 ucles 2015 [turn over (b)  the table shows some properties of the group 0 elements helium, neon, argon and krypton. elementelectron arrangementdensity of the lique \ufb01 ed gas in g / cm3melting point / \u00b0cboiling point / \u00b0c helium 2 0.15 \u2013272 \u2013269 neon 1.20 \u2013248 \u2013245 argon 2,8,8 1.40 \u2013189 \u2013186 krypton 2,8,18,8 2.15 \u2013157 \u2013152  (i)  describe how the density of the lique \ufb01 ed noble gases changes down group 0.   . ..  [1]  (ii)  deduce the electron arrangement of neon.   . ..  [1]  (iii)  what is the state of argon at \u2013188 \u00b0c?   . ..  [1]  (iv)  which element in the table has the highest melting point?   . ..  [1]  (c)  the table below shows the number of electrons, protons and neutrons in some isotopes of  helium, argon and neon.   complete the table. elementnumber of electronsnumber of protonsnumber of neutrons 3he2 22. 38ar18.18 20 .10 10 11 [3] [total: 11]",
            "16": "16 0620/21/m/j/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s15_qp_22.pdf": {
            "1": "this document consists of 16 printed pages. dc (cw) 105195/3 \u00a9 ucles 2015 [turn overcambridge international examinations cambridge international general certificate of secondary education *1585350247* chemistry  0620/22 paper 2 may/june 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen. y ou may use an hb pencil for any diagrams or graphs. do not use staples, paper clips, glue or correction fluid. do not write in any barcodes. answer all questions. electronic calculators may be used. a copy of the periodic table is printed on pa ge 16. y ou may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [ ] at the end of each question or part question. the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.",
            "2": "2 0620/22/m/j/15 \u00a9 ucles 20151 the structures of six compounds containing oxygen are shown below. o2\u2212ca2+o2\u2212ca2+ ca2+o2\u2212ca2+o2\u2212 o2\u2212ca2+o2\u2212ca2+no3\u2212 nh4+nh4+nh4+nh4+ no3\u2212 nh4+no3\u2212 no3\u2212no3\u2212no3\u2212nh4+a efbc d o c o xe oo o o hoho osoo o osisi si sisioo o osisi oo si sio o  (a) answer the following questions about these compounds. each compound, a, b, c, d, e or f,  may be used once, more than once or not at all.   (i) which compound is a compound of a noble gas? [1]   (ii) which compound can be used as a fertiliser? [1]   (iii) which compound can be used to neutralise acidic soil? [1]   (iv) which compound is a greenhouse gas? [1]   (v) which two compounds are ionic?  and [1]   (vi) which two compounds react to form calcium sulfate?  and [1]",
            "3": "3 0620/22/m/j/15 \u00a9 ucles 2015 [turn over (b) complete the symbol equation for the reaction of compound a with hydrochloric acid.  cao  +  ..hc l    cac l2  +  . [2]  (c) complete the following sentence about compounds using words from the list below. atoms            combined            mixtures molecules            separated            unreactive   a compound is a substance containing two or more different .. which are  chemically .. . [2] [total: 10]",
            "4": "4 0620/22/m/j/15 \u00a9 ucles 20152 an aqueous solution of sodium hydrogen carbonate is added to an aqueous solution of citric acid.  the mixture is stirred. the temperature is measured before and after the addition. citric acidsodium hydrogen carbonate20 \u00b0c 11 \u00b0c20 \u00b0c  (a) explain how this experiment shows that the reaction is endothermic.  .. .[1]  (b) citric acid reacts with sodium hydroxide to form the soluble salt sodium citrate.   describe how you could prepare pure dry crystals of sodium citrate from citric acid and  sodium hydroxide.  .. .  .. .  .. .  .. .  .. .  .. .[3]  (c) citric acid can be made by fermentation.   ethanol can also be made by fermentation.   which of the following are required to make ethanol by fermentation?   tick two boxes.    enzymes from yeast     temperature above 100 \u00b0c     high pressure     concentrated sulfuric acid     glucose   [2]",
            "5": "5 0620/22/m/j/15 \u00a9 ucles 2015 [turn over (d) complete the structure of ethanol to show all atoms and all bonds. oh  [1]  (e) ethanol can be made from ethene.   complete the following sentence about the formation of ethanol from ethene using words  from the list below. carbonate            catalyst hydrogen            proton            steam   ethanol can be made by reacting ethene with .. in the presence of  a .. . [2]   [total: 9]",
            "6": "6 0620/22/m/j/15 \u00a9 ucles 20153 when sodium hydrogen carbonate is heated at 60 \u00b0c, carbon dioxide is given off.  (a) (i) complete the equation for this reaction.  ..nahco3    na2co3  +  co2  +  .  [2]   (ii) what type of chemical reaction is this?    tick one box.     addition      neutralisation      oxidation      thermal decomposition   [1]  (b) an aqueous solution of sodium hydrogen carbonate is slightly alkaline.   which one of the following ph values is slightly alkaline?   put a ring around the correct answer.  ph 2            ph 7            ph 8            ph 13 [1]  (c) baking powder contains sodium hydrogen carbonate and crystals of a weak acid.    when water is added, the acid reacts with the sodium hydrogen carbonate.   (i) complete the general equation for the reaction of an acid with a carbonate.  acid + carbonate  carbon dioxide + ... + ... [2]   (ii) the diagram below shows bread baked with and without the addition of baking powder.  all other conditions were kept the same. bread baked without baking powderbread baked with baking powder    why is the bread baked with baking powder bigger?  .. .  .. .[1]   (iii) explain why the sodium hydrogen carbonate used in breadmaking must be pure.  .. .[1]",
            "7": "7 0620/22/m/j/15 \u00a9 ucles 2015 [turn over (d) the diagram shows the arrangement of carbon dioxide molecules at \u201325 \u00b0c and  100 atmospheres pressure. represents a molecule of carbon dioxide   what is the state of carbon dioxide under these conditions?   use the kinetic particle theory and the information in the diagram to explain your answer.  .. .  .. .  .. .[3]  [total: 11] 4 a student investigated the rate of reaction of zinc with dilute hydrochloric acid. zn(s)  +  2hc l(aq)    znc l2(aq)  +  h2(g)  (a) complete the labelling of the apparatus by filling in the two boxes. dilute hydrochloric acid zincthermometer water bath at 20  \u00b0c  [2]",
            "8": "8 0620/22/m/j/15 \u00a9 ucles 2015 (b) the student carried out the reaction at 20 \u00b0c using small pieces of zinc. she measured the  volume of hydrogen given off as the reaction proceeded. 60 50 40 30 20 10 0 01234 time  / min567volume of hydrogen  / cm3   (i) describe how the volume of hydrogen changes with time.  .. .  .. .[2]   (ii) at what time did the reaction stop?  .. .[1]   (iii) what volume of gas was produced over the first two minutes of the reaction?  .. .[1]   (iv) on the graph above draw a line to show how the volume of hydrogen changes when the  reaction was carried out at 30 \u00b0c. all other conditions remain the same. [2]",
            "9": "9 0620/22/m/j/15 \u00a9 ucles 2015 [turn over (c) how does the rate of reaction change when larger pieces of zinc are used?   all other conditions remain the same.  .. .[1]  (d) molten zinc chloride can be electrolysed using graphite electrodes.   (i) state the names of the product formed at: the anode   .. the cathode.  . .. [2]   (ii) graphite conducts electricity. give one other reason why graphite electrodes are used.  .. .[1]  [total: 12]",
            "10": "10 0620/22/m/j/15 \u00a9 ucles 20155 cinnamic acid is found in plants called balsams.  the structure of cinnamic acid is shown below. cc cch cchh h hc h ch co o h  (a) on the structure of cinnamic acid above, put a ring around the carboxylic acid functional  group. [1]  (b) cinnamic acid is an unsaturated compound.   (i) what is the meaning of the term unsaturated  ?  .. .  .. .[1]   (ii) describe a test for an unsaturated compound.  .. .  .. .  .. .[2]  (c) cinnamic acid reacts with sodium hydroxide to form styrene. c6h5ch=chcooh  +  2naoh    c6h5ch=ch2  +  na2co3  +  h2o   complete the word equation for this reaction.   cinnamic  sodium    .    +   styrene +  +    .  acid  hydroxide    .  [2]",
            "11": "11 0620/22/m/j/15 \u00a9 ucles 2015 [turn over (d) styrene is used to make the polymer poly(styrene).   poly(ethene) is also a polymer.   describe how poly(ethene) is made.   in your answer include the words:   \u0081 addition   \u0081 ethene   \u0081 monomer   \u0081 polymerisation  .. .  .. .  .. .[3]  (e) balsam flowers contain a mixture of pigments.   (i) describe how you could obtain a solution of this mixture of pigments from balsam flowers.  .. .  .. .  .. .[3]   (ii) a student uses chromatography to separate the pigments in balsam flowers. he puts the  pigment mixture on a sheet of chromatography paper as well as 5 spots of pure pigments  a, b, c, d and e.    the diagram below shows the results after chromatography. pigments from balsam flowersabcde    which of the pigments a, b, c, d and e are present in balsam flowers?  .. .[1]  [total: 13]",
            "12": "12 0620/22/m/j/15 \u00a9 ucles 20156 the table shows some properties of aluminium, copper, iron and sodium. metal electrical  conductivitydensity in  g / cm3melting  point / \u00b0cstrength colour aluminium very good 2.70  660 fairly strong silver copper very good 8.92 1083 very strong pink-brown iron good 7.86 1535 very strong silver sodium good 0.97   98 weak silver  (a) which two metals in the table are transition elements? explain your answer by referring to a  specific property of transition elements given in the table.  .. .  .. .  .. .[2]  (b) use the information in the table to suggest   (i) why overhead electricity cables are made from aluminium with a steel core,  .. .  .. .[2]   (ii) one reason why sodium is not used for electricity cables.  .. .  .. .[1]  (c) cobalt chloride is a transition element compound.   calcium chloride is a compound of a group ii metal.   describe one difference between cobalt chloride and calcium chloride.  .. .  .. .[1]",
            "13": "13 0620/22/m/j/15 \u00a9 ucles 2015 [turn over (d) the table below shows some observations about the reaction of four metals with water or  steam. metal observations aluminium reacts with steam when strongly heated lithium reacts rapidly with cold water magnesium reacts very slowly with cold water but rapidly with steam silver does not react with steam   place these metals in order of their reactivity. least reactive most reactive  [1]  (e) when iron is heated with steam, hydrogen is given off. 3fe + 4h2o  fe3o4 + 4h2   (i) what does the sign  mean?  .. .[1]   (ii) describe a test for hydrogen. test  . ... result  ... ..  [2]  (f) steel is an alloy of iron. write about alloys of iron.   in your answer refer to:   \u0081 the meaning of the term alloy,   \u0081 why alloys are used instead of pure iron,   \u0081 an example of the use of an alloy of iron.  .. .  .. .  .. .  .. .  .. .  .. .[4]  [total: 14]",
            "14": "14 0620/22/m/j/15 \u00a9 ucles 20157 a teacher placed a few drops of liquid bromine in the bottom of a test-tube containing a solvent.  after 10 minutes, the brown colour of the bromine had spread a little way through the solvent.   after 2 hours, the brown colour had spread throughout the solvent. at the startafter 10 minutesafter 2 hourssolvent liquid bromine    (a) use the kinetic particle theory to explain these observations.  .. .  .. .  .. .  .. .  .. .  .. .[3]  (b) bromine is a halogen in group vii.   the properties of some halogens are given in the table below. halogen melting  point / \u00b0cboiling point / \u00b0c density at  boiling point in  g / cm3electron  arrangement of  halogen atom fluorine \u2013220 \u2013188 1.51 2,7 chlorine \u2013101  \u201335 1.56 2,8,7 bromine   \u20137  +59 2,8,18,7 iodine +114 +184 4.93 2,8,18,18,7   use the information in the table to:   (i) deduce the state of fluorine at \u2013200 \u00b0c.  .. .[1]",
            "15": "15 0620/22/m/j/15 \u00a9 ucles 2015  (ii) describe how the melting point changes down group vii.  .. .[1]   (iii) estimate the density of bromine.  .. .[1]   (iv) deduce the number of completely filled electron shells in an atom of chlorine.  .. .[1]  (c) aqueous bromine reacts with aqueous potassium iodide to form iodine and potassium  bromide.   (i) complete the equation for this reaction. br2 + 2k i  . + 2kbr  [1]   (ii) explain why aqueous bromine does not react with an aqueous solution of potassium  chloride.  .. .[1]  (d) bromine reacts with fluorine to form bromine trifluoride, brf3.   calculate the relative molecular mass of bromine trifluoride.   show all your working.  [2]  [total: 11]",
            "16": "16 0620/22/m/j/15 \u00a9 ucles 2015 groupthe periodic table of the elements 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 231147 237 244 243 247 247 251 252 257 258 259 260 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 209 210 222 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 89 \u20209 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 223 ra radium 88 a x ba = relative atomic mass x = atomic symbol b = atomic (proton) numberkeydata sheet * 58\u201371 lanthanoid series \u2020 90\u2013103 actinoid series the volume of one mole of any gas is 24dm3 at room temperature and pressure (r.t.p.). to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series."
        },
        "0620_s15_qp_23.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/23   paper 2 may/june 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 16 printed pages . [turn overib15 06_0620_23/2rp\u00a9 ucles 2015 *7915342864* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/23/m/j/15 \u00a9 ucles 20151  the structures of \ufb01 ve substances are shown below. nn n hh habc dena+no3\u2013no3\u2013no3\u2013no3\u2013no3\u2013no3\u2013no3\u2013no3\u2013 k+i\u2013i\u2013 k+i\u2013i\u2013k+i\u2013k+na+cl \u2013cl \u2013 na+cl \u2013cl \u2013na+cl \u2013na+na+na+na+na+na+na+na+   answer the following questions about these substances.   each substance may be used once, more than once or not at all.  (a)  which substance, a, b, c, d or e,  (i)  is an element, ..  [1]  (ii)  turns damp red litmus paper blue, ..  [1]  (iii)  is a salt which contains atoms of three different elements, ..  [1]  (iv)  is a compound, whose aqueous solution gives a white precipitate on   addition of aqueous silver nitrate, ..  [1]  (v)  is an ionic compound, whose aqueous solution gives off ammonia when   warmed with aluminium powder and aqueous sodium hydroxide? ..  [1]  (b) (i)   give the name of compound b.   . ..  [1]  (ii)  complete the following sentences about compounds a and e using words from the list  below. atoms       gas       giant       ions       liquid       molecular       polymer       solid  compound a is a .. at room temperature. it does not conduct electricity    because it has a simple .. structure. compound e does not conduct    electricity when it is .. because its .. cannot move. [4] [total: 10]",
            "3": "3 0620/23/m/j/15 \u00a9 ucles 2015 [turn over2  a student adds an aqueous solution of sodium hydroxide to an aqueous solution of ethanoic acid.  she measures the temperature before and after the addition of sodium hydroxide. ethanoic acid solution18 \u00b0c 22 \u00b0csodium hydroxide solution at 18  \u00b0c  (a) (i)   explain how this experiment shows that the reaction is exothermic.   . ..  [1]  (ii)  complete the formula of ethanoic acid showing all atoms and bonds. h cch h [1]  (iii)  the product of the reaction is a salt called sodium ethanoate.   describe how you would prepare pure, dry crystals of sodium ethanoate from a solution of  sodium ethanoate in water.   .    .    .    . ..  [3]  (b)  ethanoic acid belongs to the carboxylic acid homologous series.   which two of the following statements describes the members of the same homologous  series?   tick two boxes.  they have the same physical properties.  they have different functional groups. they have similar chemical properties. they are all inorganic chemicals. they have the same functional group. [2]",
            "4": "4 0620/23/m/j/15 \u00a9 ucles 2015 (c)  ethanoic acid has similar properties to hydrochloric acid.   what would be observed when a small piece of magnesium is added to aqueous ethanoic  acid?   ... .   ... ...  [2] [total: 9]",
            "5": "5 0620/23/m/j/15 \u00a9 ucles 2015 [turn over3  copper( ii) sulfate is heated strongly. the products are copper( ii) oxide and sulfur trioxide.  heat cuso4  \u2192  cuo  +  so3  (a) (i)   what type of reaction is this?   tick one box.  addition neutralisation  oxidation  thermal decomposition [1]  (ii)  sulfur trioxide is an acidic gas.   what precautions must be taken when heating copper( ii) sulfate in the laboratory?   . ..  [1]  (iii)  the diagram below shows the arrangement of sulfur trioxide molecules at 30 \u00b0c. so3 moleculeskey   what is the state of sulfur trioxide at 30 \u00b0c?   use the information in the diagram to explain your answer.   .    .    . ..  [3]  (b)  sulfur trioxide dissolves in water to form sulfuric acid.  (i)  complete the symbol equation for this reaction. so3  +  h2o  \u2192  . [1]  (ii)  sulfuric acid is strongly acidic.   which one of the following ph values is strongly acidic?   put a ring around the correct answer. ph 1            ph 6            ph 7            ph 9            ph 13 [1]",
            "6": "6 0620/23/m/j/15 \u00a9 ucles 2015 (c)  copper( ii) oxide is a solid.   an aqueous solution of copper( ii) sulfate can be made by heating excess copper( ii) oxide with  dilute sulfuric acid.   draw a labelled diagram of the apparatus you would use to separate the excess copper( ii)  oxide from the solution. [2]  (d)  anhydrous copper( ii) sulfate can be used to test for water. cuso4(s)  +  5h2o(l)    cuso4.5h2o(s)  (i)  what is the meaning of the symbol  ?   . ..  [1]  (ii)  give the colour change when water is added to anhydrous copper( ii) sulfate.   from   to   ...   [2] [total: 12]",
            "7": "7 0620/23/m/j/15 \u00a9 ucles 2015 [turn over4  a student investigated the reaction of zinc carbonate with hydrochloric acid. znco3(s)  +  2hc l (aq)  \u2192  znc l 2(aq)  +  co2(g)  +  h2o(l)   she measured the decrease in mass of the reaction mixture with time. cotton wool hydrochloric acid top pan balancepieces of zinc carbonate 200.00g  (a)  explain why the mass of the reaction mixture decreased with time.   ... ...  [1]",
            "8": "8 0620/23/m/j/15 \u00a9 ucles 2015 (b)  the student carried out the reaction at 20 \u00b0c using small pieces of zinc carbonate. the graph  below shows the results. 200 199198197196195194 02 0 4 0 time  / sbalance reading/  g 60  (i)  describe how the mass of the reaction mixture changes with time.   .    . ..  [2]  (ii)  how long did it take for the reaction to stop? ... s  [1]  (iii)  calculate the decrease in mass of the reaction mixture in the \ufb01 rst 20 seconds of the  reaction. ... g  [1]  (iv)  on the grid above, draw a line to show how the mass of the reaction mixture changes  when the experiment is carried out at 30 \u00b0c and all other conditions remain the same. [2]",
            "9": "9 0620/23/m/j/15 \u00a9 ucles 2015 [turn over (v)   how does the rate of this reaction change when larger pieces of zinc carbonate are used?   . ..  [1]  (c)  the zinc chloride formed in this reaction is a salt.  (i)  give the name of another compound of zinc which, when reacted with hydrochloric acid,  makes zinc chloride.   . ..  [1]  (ii)  molten zinc chloride can be electrolysed using graphite electrodes.   give the name of the products formed at  the anode,  .. .  the cathode.    [2] [total: 11]",
            "10": "10 0620/23/m/j/15 \u00a9 ucles 20155  linalool is a compound found in the seeds of the coriander plant.   the formula of linalool is shown below. ch3ch3 ch3 cch ch hch h h h hc oh cc  (a) (i)   on the formula above, put a ring around an alcohol functional group. [1]  (ii)  how many different elements are there in one molecule of linalool?   . ..  [1]  (iii)  how many carbon atoms are there in one molecule of linalool?   . ..  [1]  (iv)  linalool is an unsaturated compound.   what feature in the formula of linalool shows that it is an unsaturated compound?   . ..  [1]  (b)  linalool can be extracted from coriander seeds.   the following statements are about the procedure for extracting linalool from coriander seeds.  a  distil the solution.  b  add a solvent to the ground up seeds.  c  grind the coriander seeds.  d  filter off the solid from the solution.  e  stir the mixture, then it leave for 24 hours.  (i)  put the statements a, b, c, d and e in the correct order.   the \ufb01 rst one has been done for you. c [2]  (ii)  on what physical property does distillation depend?   . ..  [1]",
            "11": "11 0620/23/m/j/15 \u00a9 ucles 2015 [turn over (c)   petroleum is a mixture of hydrocarbons which can be separated into useful fractions by  fractional distillation.   the diagram below shows a fractional distillation column. kerosenenaphthagasolinefuel gasfractions diesel oil fuel oil petroleum lubricating oil and bitumen  (i)  on the diagram above, put  \u2022  a letter x to show where the temperature in the column is lowest, [1]  \u2022  a letter h to show where the fraction containing molecules with the highest relative  molecular mass exits the column. [1]  (ii)  give one use of the naphtha fraction.   . ..  [1]  (d) methane is a hydrocarbon present in natural gas.  (i)  give one other source of methane.   . ..  [1]  (ii)  give one reason why scientists are concerned about the increasing amount of methane in  the atmosphere.   . ..  [1]  (iii)  to which homologous series does methane belong?   . ..  [1] [total: 13]",
            "12": "12 0620/23/m/j/15 \u00a9 ucles 20156  the table below shows the properties of some non-metallic elements, a, b, c and d. elementstate at room temperaturecolourmelting point / \u00bacelectrical conductivity a solid black 3317 good b solid grey 1410 poor c gas green \u2013101 does not conduct d solid yellow 119 does not conduct  (a) (i)   which two elements are giant covalent structures?   give a reason for your answer.   .    . ..  [2]  (ii)  which element is carbon in the form of graphite?   give a reason for your answer.   .    . ..  [2]  (iii)  which element is chlorine?   . ..  [1]  (b)  when aqueous chlorine is added to aqueous potassium bromide, the solution turns orange.   an aqueous solution of bromine and potassium chloride is formed.   describe and explain what happens when aqueous bromine is added to separate solutions of  aqueous potassium chloride and aqueous potassium iodide.   ... .   ... .   ... .   ... .   ... .   ... ...  [4]",
            "13": "13 0620/23/m/j/15 \u00a9 ucles 2015 [turn over (c)   chlorine is used in water treatment.   explain why.   ... ...  [1]  (d)  complete the diagram below to show the arrangement of electrons in a molecule of chlorine. cl cl [2]  (e)  chlorine reacts with indium, in, to form a chloride with the formula shown below. cl clcl clincl clin  (i)  give the molecular formula for this chloride.   . ..  [1]  (ii)  how many protons does indium have in its nucleus?   use the periodic table to help you.   . ..  [1] [total: 14]",
            "14": "14 0620/23/m/j/15 \u00a9 ucles 20157  many \ufb02 owers produce volatile oils. these oils are responsible for the sweet scent (perfume) of  many \ufb02 owers.  (a)  what does the term volatile  mean?    ... ...  [1]  (b)  a teacher placed some highly-scented \ufb02 owers at the front of the class.   at \ufb01 rst, the students at the back of the class could not smell the scent. after two minutes they  could smell the scent.   use the kinetic particle theory to explain these observations.   ... .   ... .   ... .   ... .   ... ...  [3]  (c)  many plant oils are unsaturated hydrocarbons.   alkenes are also unsaturated hydrocarbons.   the table shows some properties of four alkenes. alkenemolecular formularelative molecular  massmelting point / \u00bacboiling point / \u00bac ethene c2h4 28 \u2013161 \u2013103 propene c3h6 42 \u2013185 \u2013 47 butene c4h8 56 \u2013 6 pentene c5h10 70 \u2013165 +30  (i)  how does the boiling point of these alkenes change as the number of carbon atoms in the  alkene increases?   . ..  [1]  (ii)  why is it dif \ufb01 cult to predict the melting point of butene?   . ..  [1]",
            "15": "15 0620/23/m/j/15 \u00a9 ucles 2015 [turn over (iii)  the relative molecular mass of each alkene differs from the next by 14.  which group of atoms is responsible for this difference.  tick one box.  ch4  ch3  ch2  ch [1]  (iv)  complete the word equation for the complete combustion of ethene. ethene  +  ...  \u2192  carbon dioxide  +  ... [2]  (d)  a radioactive isotope of carbon called carbon-14 can be used to date old pieces of cloth.  (i)  what is meant by the term isotope ?   .    . ..  [1]  (ii)  carbon-14 contains 8 neutrons and 6 protons.   the symbol for carbon-14 can be written 14c6.   write the symbol for carbon-12 in a similar way. [1] [total: 11]",
            "16": "16 0620/23/m/j/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_s15_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 (extended) may/june 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib15 06_0620_31/fp\u00a9 ucles 2015 *1045436086* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/31/m/j/15 \u00a9 ucles 20151 (a)  coal is a solid fossil fuel.   name two other fossil fuels.   ... ...  [2]  (b)  two of the elements present in a sample of coal are carbon and sulfur.   a sample of coal was heated in the absence of air and the products included water, ammonia  and hydrocarbons.   name three  other elements present in this sample of coal.   ... ...  [2]  (c)  sulfur, present in coal, is one major cause of acid rain. sulfur burns to form sulfur dioxide which  reacts with rain water to form sulfuric acid.  (i)  describe how the high temperatures in vehicle engines are another cause of acid rain.   .    .    . ..  [3]  (ii)  give two harmful effects of acid rain.   .    . ..  [2]  (d)  in 2010, a large coal-burning power station in the uk was converted to burn both coal and wood.   explain why the combustion of wood rather than coal can reduce the effect of the emissions from this power station on the level of carbon dioxide in the atmosphere.   ... .   ... .   ... .   ... ...  [3] [total: 12]",
            "3": "3 0620/31/m/j/15 \u00a9 ucles 2015 [turn over2  iron from the blast furnace is impure. it contains about 5% of impurities, mainly carbon, sulfur,  silicon and phosphorus, which have to be removed when this iron is converted into steel.  (a)  explain how the addition of oxygen and calcium oxide removes these impurities. include an equation for a reaction of oxygen and a word equation for a reaction of calcium oxide in this process.   ... .   ... .   ... .   ... .   ... .   ... . [5]  (b)  mild steel is the most common form of steel. mild steel contains a maximum of 0.3% of carbon.    high carbon steel contains 2% of carbon. it is less malleable and much harder than mild steel.  (i)  give a use of mild steel.   . ..  [1]  (ii)  suggest a use of high carbon steel.   . ..  [1]  (iii)  explain why metals are malleable.   .    .    .    . ..  [3]  (iv)  suggest an explanation why high carbon steel is less malleable and harder than mild steel.   .    .    . ..  [2] [total: 12]",
            "4": "4 0620/31/m/j/15 \u00a9 ucles 20153 (a)   the reactions between metals and acids are redox reactions. zn  +  2h+  \u2192  zn2+  +  h2  (i)  which change in the above reaction is oxidation, zn to zn2+ or 2h+ to h2? give a reason  for your choice.   .    . ..  [2]  (ii)  which reactant in the above reaction is the oxidising agent? give a reason for your choice.   .    . ..  [2]  (b)  the rate of reaction between a metal and an acid can be investigated using the apparatus  shown below. hydrochloric acidgas syringe20 40 60 80 100 zinc foil   a piece of zinc foil was added to 50 cm3 of hydrochloric acid, of concentration 2.0 mol / dm3. the  acid was in excess. the hydrogen evolved was collected in the gas syringe and its volume measured every minute. the results were plotted and labelled as graph 1. volume time00graph 2 (with copper) graph 1   the experiment was repeated to show that the reaction between zinc metal and hydrochloric  acid is catalysed by copper. a small volume of aqueous copper( ii) chloride was added to the  acid before the zinc was added. the results of this experiment were plotted on the same grid and labelled as graph 2.",
            "5": "5 0620/31/m/j/15 \u00a9 ucles 2015 [turn over (i)  explain why the reaction mixture in the second experiment contains copper metal. include  an equation in your explanation.   .    . ..  [2]  (ii)  explain how graph 2 shows that copper catalyses the reaction.   .    .    . ..  [3]  (c)  if the \ufb01 rst experiment was repeated using ethanoic acid, ch3cooh, instead of hydrochloric  acid, how and why would the graph be different from graph 1?   ... .   ... .   ... .   ... ...  [4]  (d)  calculate the maximum mass of zinc which will react with 50 cm3 of hydrochloric acid, of  concentration 2.0 mol / dm3. zn  +  2hc l  \u2192  znc l 2  +  h2   show your working. [3] [total: 16]",
            "6": "6 0620/31/m/j/15 \u00a9 ucles 20154  the alcohols form a homologous series.  (a) (i)   give three  characteristics which all members of a homologous series share.   .    .    .    . ..  [3]  (ii)  give the name of the third member of this series.  name . [1] (iii)  deduce the molecular formula of the alcohol whose m r = 158. show your working.   .    .    . ..  [2]  (b)  explain why the following two alcohols are isomers. ch3ch3 ch3oh oh c ch3ch2ch2ch2   ... .   ... ...  [2]",
            "7": "7 0620/31/m/j/15 \u00a9 ucles 2015 [turn over (c)  this question is based on typical reactions of butan-1-ol.  (i)  when butan-1-ol, ch3\u2013ch2\u2013ch2\u2013ch2\u2013oh, is passed over the catalyst silicon( iv) oxide,  water is lost.   deduce the name and the structural formula of the organic product in this reaction.  name . structural formula [2]  (ii)  suggest the name of the ester formed from butanol and ethanoic acid.   . ..  [1]  (iii)  butan-1-ol is oxidised by acidi \ufb01 ed potassium manganate( vii).   deduce the name and the structural formula of the organic product in this reaction.  name . structural formula [2] [total: 13]",
            "8": "8 0620/31/m/j/15 \u00a9 ucles 20155  the halogens are a group of non-metals in group vii of the periodic table.  (a)  the reactivity of the halogens decreases down the group.   describe an experiment which shows that chlorine is more reactive than iodine. include an  equation in your answer.   ... .   ... .   ... .   ... ...  [3]  (b)  the halogens form interhalogen compounds. these are compounds which contain two different  halogens.   deduce the formula of the compound which has the composition 0.013 moles of iodine atoms  and 0.065 moles of \ufb02 uorine atoms.   ... .   ... ...  [2]  (c)  iodine reacts with chlorine to form a dark brown liquid, iodine monochloride. chlorine supplied crystalsof iodine i2(s)  +  c l 2(g)  \u2192  2icl (l)  dark brown   when more chlorine is added and the tube is sealed, a reversible reaction occurs and the  reaction comes to equilibrium. icl (l)  +  c l 2(g)    icl 3(s)  dark brown yellow  (i)  give another example of a reversible reaction.   . ..  [1]  (ii)  explain the term equilibrium .   .    . ..  [2]",
            "9": "9 0620/31/m/j/15 \u00a9 ucles 2015 [turn over (d)  chlorine is removed from the tube and a new equilibrium is formed.   explain why there is less of the yellow solid and more dark brown liquid in the new equilibrium  mixture.   ... .   ... .   ... ...  [2]  (e)  a sealed tube containing the equilibrium mixture is placed in ice-cold water. there is an increase  in the amount of yellow solid in the equilibrium mixture.   what can you deduce about the forward reaction in this equilibrium? icl (l)  +  c l 2(g)    icl 3(s)   explain your deduction.   ... .   ... .   ... .   ... ...  [3] [total: 13]",
            "10": "10 0620/31/m/j/15 \u00a9 ucles 20156  acid-base reactions are examples of proton transfer.  (a)  ethylamine is a weak base and sodium hydroxide is a strong base.  (i)  in terms of proton transfer, explain what is meant by the term weak base .   .    . ..  [2]  (ii)  given aqueous solutions of both bases, describe how you could show that sodium  hydroxide is the stronger base. how could you ensure a \u2018fair\u2019 comparison between the two solutions?   .    .    .    . ..  [3]  (b)  ethylamine reacts with acids to form salts. ch 3ch2nh2  +  hc l  \u2192  ch3ch2nh3cl  ethylammonium chloride  (i)  complete the equation for the reaction between sulfuric acid and ethylamine. name the  salt formed. ..ch3ch2nh2  +    \u2192  .  name of salt . [3] (ii)  amines and their salts have similar chemical properties to ammonia and ammonium salts.     suggest a reagent that could be used to displace the weak base, ethylamine, from its salt  ethylammonium chloride.   . ..  [1]",
            "11": "11 0620/31/m/j/15 \u00a9 ucles 2015 [turn over (c)  gases diffuse, which means that they move to occupy the total available volume.  (i)  explain, using kinetic particle theory, why gases diffuse.   .    .    . ..  [2]  (ii)  when the colourless gases hydrogen bromide and ethylamine come into contact, a white  solid is formed. ch3ch2nh2(g)  +  hbr(g)  \u2192  ch3ch2nh3br(s)  white solid   the following apparatus can be used to compare the rates of diffusion of the two gases  ethylamine and hydrogen bromide. gives off ch3ch2nh2(g)gives off hbr(g) cotton wool soaked in ethylamine(aq)cotton wool soaked in conc. hydrobromic acidabc   predict at which position, a, b or c, the white solid will form. explain your choice.   .    .    . ..  [3] [total: 14]",
            "12": "12 0620/31/m/j/15 \u00a9 ucles 2015 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series."
        },
        "0620_s15_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) may/june 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. modified languagecambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 11 printed pages and 1 blank page. [turn overib15 06_0620_32/fp\u00a9 ucles 2015 *9449031324* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/32/m/j/15 \u00a9 ucles 20151  complete the following table which gives the number of protons, electrons and neutrons in each  of the \ufb01 ve particles. particlenumber of protonsnumber of electronsnumber of neutrons ..19 19 20 56fe26.. .. .. ..324 +3 70ga31.. .. .. ..34 36 45 [total: 8]",
            "3": "3 0620/32/m/j/15 \u00a9 ucles 2015 [turn over2  the table shows the melting points, boiling points and electrical properties of \ufb01 ve substances,  a to e. substancemelting point / \u00b0cboiling point / \u00b0celectrical conductivity of solidelectrical conductivity of liquid a \u20137 59 poor poor b 1083 2567 good good c 755 1387 poor good d 43 181 poor poor e 1607 2227 poor poor   choose a substance from the table above to match each of the following descriptions. a  substance may be used once, more than once or not at all. justify each choice with evidence from the table.   one has been completed as an example.    this substance is covalent and is a solid at room temperature (25 \u00b0c).  ..   evidence  . ...   ... .  (a) this substance has a giant covalent structure.  ..   evidence  . ...   ... ...  [3]  (b)  this substance is a metal.  ..  evidence      ... ...  [2]  (c)  this substance is a liquid at room temperature (25 \u00b0c).  ..  evidence      ... ...  [3]  (d)  this substance is an ionic solid.  ..  evidence      ... ...  [3] [total: 11]not conduct as a liquid, so it is covalent .its melting point is above room temperature. it has a low melting point and it doesd",
            "4": "4 0620/32/m/j/15 \u00a9 ucles 20153  calcium reacts with nitrogen to form the ionic compound calcium nitride, ca3n2.  (a)  draw a diagram, based on the correct formula, which shows the charges on the ions and the  arrangement of the electrons around the negative ion.   use o to represent an electron from a calcium atom.   use x to represent an electron from a nitrogen atom. [3]  (b)  in the lattice of calcium nitride, the ratio of calcium ions to nitride ions is 3 : 2.  (i)  what is meant by the term lattice ?   .    . ..  [2]  (ii)  in terms of ionic charges, explain why the ratio of ions is 3 : 2.   .    . ..  [2]  (c)  the reaction between calcium and nitrogen to form calcium nitride is a redox reaction.  in terms of electron transfer, explain why calcium is the reducing agent.  ... .   ... .   ... .   ... ...  [3] [total: 10]",
            "5": "5 0620/32/m/j/15 \u00a9 ucles 2015 [turn over4  ammonia is made by the haber process. n2(g)  +  3h2(g)    2nh3(g)   the forward reaction is exothermic.   typical reaction conditions are:  \u2022  finely divided iron catalyst,  \u2022  temperature 450 \u00b0c,  \u2022  pressure 200 atmospheres.  (a)  explain why the catalyst is used as a very \ufb01 ne powder and larger pieces of iron are not used.   ... .   ... .   ... ...  [2]  (b)  using the above conditions, the equilibrium mixture contains about 15% ammonia.   state two changes to the reaction conditions which would increase the percentage of  ammonia at equilibrium.   ... .   ... .   ... ...  [2]  (c)  suggest why the changes you have described in (b) are not used in practice.   ... .   ... .   ... ...  [2] [total: 6]",
            "6": "6 0620/32/m/j/15 \u00a9 ucles 20155  three common methods of preparing salts are shown below.  method a  adding an excess of an insoluble base or carbonate or metal to a dilute acid and  removing excess by \ufb01 ltration  method b using a burette and indicator  method c mixing two solutions to obtain the salt by precipitation   for each of the following salt preparations, choose a method, a, b or c. name any additional  reagent which is needed and complete the equation.  (a) the soluble salt, nickel chloride, from the insoluble compound nickel carbonate  method  ...   reagent  . .  word equation  ... . [3]  (b) the insoluble salt, lead( ii) bromide, from aqueous lead( ii) nitrate  method  ...   reagent  . .  ionic equation    +    \u2192  pbbr2 [3]  (c)  the soluble salt, lithium sulfate, from the soluble base lithium hydroxide  method  ...   reagent  . .  equation   . [4] [total: 10]",
            "7": "7 0620/32/m/j/15 \u00a9 ucles 2015 [turn over6  the atacama desert in chile has deposits of the salt sodium nitrate. very large amounts of this  salt were exported to europe for use as a fertiliser. after the introduction of the haber process in 1913, this trade rapidly diminished.  (a) (i)   explain why the introduction of the haber process reduced the demand for  sodium nitrate.   .    . ..  [2]  (ii)  suggest why surface deposits of sodium nitrate only occur in areas with very low rainfall  such as desert areas.   . ..  [1]  (iii)  the desert has smaller surface deposits of potassium nitrate.   suggest why potassium nitrate is a better fertiliser than the sodium salt.   . ..  [1]  (b)  all nitrates decompose when heated. the extent to which a nitrate decomposes is  determined by the metal in the salt.  (i)  sodium nitrate decomposes to form sodium nitrite, nano 2.   write the equation for decomposition of sodium nitrate.   . ..  [2]  (ii)  sodium nitrite is a reducing agent.   what would be observed if an excess of sodium nitrite solution was added to a solution  of acidi \ufb01 ed potassium manganate( vii)?   . ..  [2]  (iii)  copper( ii) nitrate decomposes to form copper( ii) oxide, nitrogen dioxide and oxygen.   what is the relationship between the extent of decomposition and the reactivity of the  metal in the nitrate?   .    . ..  [1]",
            "8": "8 0620/32/m/j/15 \u00a9 ucles 2015 (c)  the equation for the decomposition of copper( ii) nitrate is given below. 2cu(no3)2  \u2192  2cuo  +  4no2  +  o2  (i)  predict what you would observe when copper( ii) nitrate is heated.   .    .    . ..  [3]  (ii)  copper( ii) nitrate forms a series of hydrates with the formula cu(no3)2.xh2o.   all these hydrates decompose to form copper( ii) oxide.   1 mole of cu(no3)2.xh2o forms 1 mole of cuo.   what is meant by 1 mole of a substance?   .    . ..  [2]  (iii)  7.26 g of a hydrate, cu(no3)2.xh2o, formed 2.4 g copper( ii) oxide.   number of moles of cuo formed = ..   number of moles of cu(no3)2.xh2o in 7.26 g = ..   mass of 1 mole of cu(no3)2.xh2o = .. g   mass of 1 mole of cu(no3)2 is 188 g   the value of x in this hydrate = .. [4] [total: 18]",
            "9": "9 0620/32/m/j/15 \u00a9 ucles 2015 [turn over7  alcohols can be made by fermentation or from petroleum.  (a)  ethanol can be made by the fermentation of glucose.  yeast  c6h12o6(aq)    2c2h5oh(aq)  +  2co2(g) exothermic reaction   yeast are living single-cell fungi which ferment glucose by anaerobic respiration. this  reaction is catalysed by enzymes from the yeast.  (i)  what is meant by the term respiration ?   .    .    . ..  [3]  (ii)  anaerobic  means in the absence of oxygen.   name the products formed from respiration in the presence  of oxygen.   . ..  [1]  (iii)  what are enzymes?   . ..  [1]  (iv)  suggest a method of measuring the rate of this reaction.   .    . ..  [1]  (b)  the following observations were noted.  \u2022  when a small amount of yeast was added to the aqueous glucose the reaction started  and the solution went slightly cloudy.  \u2022   the reaction rate increased and the solution became cloudier and warmer.  \u2022   after a while, the reaction rate decreased and eventually stopped, leaving a 14%  solution of ethanol in water.  (i)  why did the reaction rate increase?   . ..  [1]  (ii)  suggest an explanation for the increase in cloudiness of the solution.   . ..  [1]  (iii)  give two reasons why the fermentation stopped.   .    . ..  [2]",
            "10": "10 0620/32/m/j/15 \u00a9 ucles 2015 (c)  one use of ethanol is in alcoholic drinks.   give two other uses of ethanol.   ... ...  [2]  (d)  alcohols can be made from petroleum by the following sequence of reactions. alkanes from petroleum  \u2192  alkene  \u2192  alcohol   describe the manufacture of ethanol from hexane, c6h14. include in your description an  equation and type of reaction for each step.   ... .   ... .   ... .   ... ...  [5] [total: 17]",
            "11": "11 0620/32/m/j/15 \u00a9 ucles 2015blank page",
            "12": "12 0620/32/m/j/15 \u00a9 ucles 2015 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series."
        },
        "0620_s15_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) may/june 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib15 06_0620_33/fp \u00a9 ucles 2015 *5054745155* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/33/m/j/15 \u00a9 ucles 20151  use your copy of the periodic table to help you answer these questions.  (a)  predict the formula of each of the following compounds.  (i) aluminium \ufb02 uoride    [1]  (ii) arsenic oxide  ... .  [1]  (iii) silicon bromide  . .  [1]  (b)  deduce the formula of each of the following ions.  (i) phosphide  ... ..  [1]  (ii) barium  .. .  [1]  (iii) francium     [1]  (c)  draw a diagram showing the arrangement of the valency electrons in one molecule of the  covalent compound carbon dioxide.   use x to represent an electron from a carbon atom.   use o to represent an electron from an oxygen atom. [3] [total: 9]",
            "3": "3 0620/33/m/j/15 \u00a9 ucles 2015 [turn over2  this question is concerned with the following oxides.  aluminium oxide  carbon monoxide copper( ii) oxide  silicon( iv) oxide  sodium oxide sulfur dioxide zinc oxide   choose one oxide from the above list to match each of the following descriptions. an oxide may be  used once, more than once or not at all.  (a)  this oxide does not react with acid or alkali.  ...  [1]  (b)  this oxide reacts with water to give a strong alkali solution.  ...  [1]  (c)  this oxide is used as a bleach.  ...  [ 1]  (d)  this oxide is amphoteric.   .  [1]  (e)  this oxide has a giant covalent structure.  ...  [1]  (f)  this oxide is soluble in water and it is acidic.  ..  [1] [total: 6]",
            "4": "4 0620/33/m/j/15 \u00a9 ucles 20153  quicklime, which is calcium oxide, is made by heating limestone in a furnace. caco3(s)    cao(s)  +  co2(g)   the reaction does not come to equilibrium.  (a)  suggest why the conversion to calcium oxide is complete.   ... ...  [1]  (b)  calcium hydroxide, slaked lime, is made from calcium oxide.   write an equation for this reaction.   ... ...  [2]  (c)  calculate the maximum mass of calcium oxide which could be made from 12.5 tonnes of  calcium carbonate. 1 tonne = 1 \u00d7 106 g.   ... .   ... .   ... ...  [2]  (d)  limestone is used in agriculture to reduce the acidity of soil and for the desulfurisation of \ufb02 ue  gases in power stations.  (i)  most crops thrive in soils whose ph is close to 7. calcium carbonate, which is insoluble  in water, and calcium oxide, which is slightly soluble in water, are both used to reduce the acidity of soils.     suggest two advantages of using calcium carbonate for this purpose.  1.  .. ...  2.  .. .  [2]  (ii)  explain the chemistry of desulfurisation of \ufb02 ue gases.   .    .    .    . ..  [3]  (iii)  give one other use of calcium carbonate.   . ..  [1] [total: 11]",
            "5": "5 0620/33/m/j/15 \u00a9 ucles 2015 [turn over4 (a) (i)   coal is a solid fossil fuel.   name another fossil fuel.   . ..  [1]  (ii)  explain what is meant by the term fossil fuel .   .    . ..  [2]  (b)  the burning of fossil fuels is largely responsible for the formation of acid rain. two of the acids  in acid rain are sulfuric acid and nitric acid.  (i)  explain how the combustion of coal can form sulfuric acid.   .    .    . ..  [3]  (ii)  high temperatures generated by the combustion of fossil fuels can lead to the formation  of nitric acid. explain.   .    .    . ..  [3]  (iii)  nitric acid contains nitrate ions.   describe a test for nitrate ions.   .    . ..  [2]  (iv)  explain how you could determine which one of two samples of acid rain had the higher  concentration of hydrogen ions.   .    . ..  [2] [total: 13]",
            "6": "6 0620/33/m/j/15 \u00a9 ucles 20155  the law of constant composition states that all pure samples of a compound contain the same  elements in the same proportion by weight.   a typical experiment to test this law is to prepare the same compound by different methods and  then show that the samples have the same composition.   methods of making copper( ii) oxide include:  \u2022 heating copper carbonate,  \u2022 heating copper hydroxide,  \u2022 heating copper nitrate,  \u2022 heating copper foil in air.  (a)  complete the following equations.  (i) cuco3  \u2192  .  +  . [1]  (ii) cu(oh)2  \u2192  .  +  . [1]  (iii) 2cu(no3)2  \u2192  .  +  4no2  +  . [2]  (b)  copper oxide can be reduced to copper by heating in hydrogen.  (i)  what colour change would you observe during the reduction?   . ..  [1]  (ii)  explain why the copper must be allowed to cool in hydrogen before it is exposed to air.   . ..  [2]  (iii)  name another gas which can reduce copper( ii) oxide to copper.   . ..  [1]  (iv)  name a solid which can reduce copper( ii) oxide to copper.   . ..  [1]",
            "7": "7 0620/33/m/j/15 \u00a9 ucles 2015 [turn over (c)  the table below shows the results obtained by reducing the copper( ii) oxide produced by  different methods to copper.  (i) complete the table. source of copper( ii) oxidemass of copper( ii) oxide / gmass of copper / gpercentage copper / % cuco3 2.37 1.89 79.7 cu(oh)2 2.51 1.99 cu(no3)2 2.11 1.68 cu and o2 2.29 1.94 [2]  (ii)  one of the samples of copper( ii) oxide is impure.   identify this sample and suggest an explanation why the percentage of copper in this  sample is bigger than in the other three samples.   .    . ..  [2] [total: 13]",
            "8": "8 0620/33/m/j/15 \u00a9 ucles 20156  chemical reactions are always accompanied by an energy change.  (a)  aluminium is extracted by the electrolysis of a molten mixture which contains aluminium oxide,  al 2o3. this decomposes to form aluminium at the negative electrode and oxygen at the positive  electrode.  (i)  write an ionic equation for the reaction at the negative electrode.   . ..  [2]  (ii)  complete the ionic equation for the reaction at the positive electrode. 2o2\u2013  \u2192  ...  +  ... [2]  (iii)  is the reaction exothermic or endothermic? explain your answer.   .    . ..  [1]  (b)  the cell shown below can be used to determine the order of reactivity of metals. v copper electrodemagnesium electrode mgso4(aq) cuso4(aq) porous barrier  (i)  is the reaction in the cell exothermic or endothermic? explain your answer.   .    . ..  [1]",
            "9": "9 0620/33/m/j/15 \u00a9 ucles 2015 [turn over (ii)  explain why the mass of the magnesium electrode decreases and the mass of the copper  electrode increases.   .    . ..  [2]  (iii)  how could you use this cell to determine which is the more reactive metal, magnesium or  manganese?   .    . ..  [2]  (c)  the combustion of propane, c3h8, is exothermic.   give an equation for the complete combustion of propane.   ... ...  [2]  (d)  photosynthesis is an unusual endothermic reaction.  (i)  where does the energy for photosynthesis come from?   . ..  [1]  (ii)  give the word equation for photosynthesis.   . ..  [1] [total: 14]",
            "10": "10 0620/33/m/j/15 \u00a9 ucles 20157 (a)  alkanes and alkenes are both hydrocarbons.  (i)  how does the structure of alkenes differ from the structure of alkanes?   . ..  [1]  (ii)  is the straight-chain hydrocarbon c22h44 an alkane or an alkene? explain your choice.   .    . ..  [2]  (iii)  describe how you could distinguish between pentane and pentene.  test   ..  result with pentane  .   result with pentene  .  [3]  (b)  alkenes polymerise to form poly(alkenes).  (i)  the alkene 1,1-dichloroethene has the structural formula given below. cl c clh c h   draw the structural formula of the polymer formed by the polymerisation of  1,1-dichloroethene. [3]",
            "11": "11 0620/33/m/j/15 \u00a9 ucles 2015 [turn over (ii)  the structural formula of a different polymer is given below. c ch3cch 3cch 3ch h h h ch3   deduce the structural formula of the monomer used to form this polymer. [2]  (iii)  there are two types of polymerisation - addition and condensation.   explain the difference between them.   .    .    . ..  [2]  (iv)  there are two types of condensation polymer.   give the name of one type of condensation polymer.   .    . ..  [1] [total: 14]",
            "12": "12 0620/33/m/j/15 \u00a9 ucles 2015 group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series."
        },
        "0620_s15_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test may/june 2015  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 8 printed pages. [turn overib15 06_0620_51/3rp\u00a9 ucles 2015 *7727926786* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/51/m/j/15 \u00a9 ucles 20151  you are going to investigate what happens when aqueous sodium hydroxide reacts with aqueous  solutions of two different acids, a and b.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   use a measuring cylinder to pour 50 cm3 of aqueous sodium hydroxide into the polystyrene  cup provided. put the cup into a 250 cm3 beaker for support. measure the initial temperature of  the solution and record it in the table below.   fill the burette with the solution of acid a provided to the 0.0 cm3 mark.   add 5.0 cm3 of acid a to the aqueous sodium hydroxide in the cup and stir the mixture.   measure and record the maximum temperature of the solution in the table below. add a further  5.0 cm3 of acid a to the cup and stir the mixture. measure and record the temperature of the  mixture in the table below.   continue to add 5.0 cm3 portions of acid a to the cup, until a total volume of 40 cm3 of acid has  been added. stir after each addition and measure and record the temperatures in the table.   at the end of this experiment, pour the solution away and rinse the polystyrene cup. volume of acid a added / cm3 temperature of solution in polystyrene cup / \u00b0c 0.0 5.0 10.015.020.025.030.035.040.0 [3]",
            "3": "3 0620/51/m/j/15 \u00a9 ucles 2015 [turn over (b)  experiment 2   empty the burette and rinse it with distilled water. half \ufb01 ll the burette with the solution of acid b  and swirl the contents. discard this acid.   now \ufb01 ll the burette to the 0.0 cm3 mark with the solution of acid b.   repeat experiment 1 using acid b instead of acid a.   record your results in the table below. volume of acid b added / cm3 temperature of solution in polystyrene cup / \u00b0c 0.0 5.0 10.015.020.025.030.035.040.0 [3]",
            "4": "4 0620/51/m/j/15 \u00a9 ucles 2015 (c)  plot the results for experiments 1 and 2 on the grid and draw a smooth line graph for each  experiment.   clearly label your graphs. 5 01 0 1 5 volume of acid added  / cm320 25 30 35 4050 40 30 20 10temperature of solution/  \u00b0c [5]  (d)  use your graph  to estimate the temperature of the reaction mixture when 8 cm3 of acid b were  added to 50 cm3 of aqueous sodium hydroxide.   show clearly on the graph  how you worked out your answer.   ... ...  [2]",
            "5": "5 0620/51/m/j/15 \u00a9 ucles 2015 [turn over (e)  what type of chemical reaction, other than neutralisation, occurs when acid a reacts with  sodium hydroxide?   ... ...  [1]  (f)  why was the burette rinsed \ufb01 rstly with distilled water and then with acid b before starting  experiment 2?   ... .   ... ...  [2]  (g)  the solutions of acids a and b are the same concentration.  (i)  in which experiment is the maximum temperature change greater?   . ..  [1]  (ii)  suggest why the maximum temperature change is greater in this experiment.   .    . ..  [1]  (h)  describe one source of error in experiment 2. suggest an improvement to reduce this source  of error.  source of error  . ..  improvement  . ...  [2] [total: 20]",
            "6": "6 0620/51/m/j/15 \u00a9 ucles 20152  you are provided with solid c, which is a salt containing two cations and one anion.   carry out the following tests on solid c recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solid c (a)  describe the appearance of solid c.   [1] (b)  use a spatula to put a little of solid c into a  hard-glass test-tube. heat the solid gently and then strongly.   test any gases given off with damp ph  indicator paper. ..  ..  [3] tests on a solution of c add about 10 cm3 of distilled water to the rest of  solid c, stopper and shake to dissolve. divide the solution into four equal portions in four test-tubes. carry out the following tests. (c)  to the \ufb01 rst portion of the solution, add  aqueous sodium hydroxide using a teat pipette.   now add excess aqueous sodium  hydroxide to the mixture.   heat the mixture gently and test any gases  given off.  [2]   [1]  ..  [2] (d)  to the second portion of the solution, add  excess aqueous ammonia. ..   [2] (e)  to the third portion of the solution, add a  few drops of dilute nitric acid and about 1 cm 3 of aqueous silver nitrate.   [1] (f)  to the fourth portion of the solution, add  a few drops of dilute nitric acid and about 1 cm 3 of barium nitrate solution. ..   [2]",
            "7": "7 0620/51/m/j/15 \u00a9 ucles 2015 [turn over (g)  what does test (b) tell you about the nature of solid c?   ... .   ... .   ... ...  [2]  (h)  what does test (e) tell you about the nature of solid c?   ... ...  [1]  (i)  what conclusions can you draw about the identity of solid c?   ... .   ... ...  [3] [total: 20]",
            "8": "8 0620/51/m/j/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_s15_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test may/june 2015  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 8 printed pages and 1 insert. [turn overib15 06_0620_52/3rp\u00a9 ucles 2015 *6194711301* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/52/m/j/15 \u00a9 ucles 20151  you are going to investigate the rate of reaction between hydrochloric acid and aqueous sodium  thiosulfate. when these chemicals react they form a precipitate which makes the solution go cloudy. the formation of this precipitate can be used to show how fast the reaction proceeds.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out \ufb01 ve experiments using the apparatus shown below. aqueous sodium thiosulfateeye 10 cm3 of hydrochloric acid 250  cm3 conical flask printed insert printed text  (a)  experiment 1   use the large measuring cylinder to pour 50 cm3 of aqueous sodium thiosulfate into a conical  \ufb02 ask. place the conical \ufb02 ask on the printed insert provided.   fill the small measuring cylinder with 10 cm3 of the hydrochloric acid provided.   add the acid to the solution in the conical \ufb02 ask and immediately start your timer and swirl the  mixture.   measure the time taken for the printed text to disappear from view. record the time in the table.    pour the solution away and rinse the conical \ufb02 ask with distilled water.  (b)  experiment 2   use the large measuring cylinder to pour 40 cm3 of aqueous sodium thiosulfate into the conical  \ufb02 ask, followed by 10 cm3 of distilled water. place the conical \ufb02 ask on the printed insert.   fill the small measuring cylinder with 10 cm3 of the hydrochloric acid provided.   add the acid to the solution in the \ufb02 ask, start your timer and swirl the mixture.   measure the time taken for the printed text to disappear from view. record the time in the table.",
            "3": "3 0620/52/m/j/15 \u00a9 ucles 2015 [turn over (c)  experiment 3   repeat experiment 2 using 35 cm3 of aqueous sodium thiosulfate and 15 cm3 of distilled water.   record the time in the table.  (d)  experiment 4   repeat experiment 2 using 30 cm3 of aqueous sodium thiosulfate and 20 cm3 of distilled water.   record the time in the table.  (e)  experiment 5   repeat experiment 2 using 20 cm3 of aqueous sodium thiosulfate and 30 cm3 of distilled water.   record the time in the table.  (f)  complete the table. experimentvolume of aqueous sodium thiosulfate / cm3volume of distilled water / cm3time for printed text to disappear / s 1 2345 [4]",
            "4": "4 0620/52/m/j/15 \u00a9 ucles 2015 (g)  plot the results you have obtained on the grid and draw a smooth line graph. 00 10 20 30 volume of aqueous sodium thiosulfate  / cm3time for printed text to disappear  / s 40 50 60 [4]",
            "5": "5 0620/52/m/j/15 \u00a9 ucles 2015 [turn over (h)   describe the appearance of the solution in the conical \ufb02 ask at the end of each experiment.   ... ...  [1]  (i) (i)   from your graph , deduce the time for the printed text to disappear if the experiment  was  repeated using 25 cm3 of aqueous sodium thiosulfate and 25 cm3 of distilled water.   show clearly on the grid  how you worked out your answer.   . ..  [3]  (ii)  sketch on the grid  the curve you would expect if the experiments were repeated at a  lower temperature. label this curve. [1]  (j) (i)   in which experiment was the rate of reaction greatest?   . ..  [1]  (ii)  explain why the rate of reaction was greatest in this experiment.   .    .    . ..  [1]  (k)  a student carried out a sixth experiment using 60 cm3 of aqueous sodium thiosulfate.   why would this not be an appropriate volume to use in this series of experiments?   ... .   ... ...  [2]  (l)  suggest and explain the effect of  (i)  using a burette to measure the volume of the hydrochloric acid,   .    . ..  [2]  (ii)  using a 100 cm3 conical \ufb02 ask.   .    . ..  [2] [total: 21]",
            "6": "6 0620/52/m/j/15 \u00a9 ucles 20152  you are provided with a mixture of two solids, j and k, which are both salts. j is water soluble and  k is insoluble.   carry out the following tests on the mixture, recording all of your observations in the table.   conclusions must not be written in the table. tests observations (a)  describe the appearance of the mixture.   [1] add 10 cm3 of distilled water to the mixture.  stopper the boiling tube and shake the mixture  for a minute. filter the mixture and keep the residue for tests later. tests on the \ufb01 ltrate divide the solution into three equal portions in  three test-tubes. (b)  to the \ufb01 rst portion of the solution, add  about 1 cm 3 of aqueous sodium hydroxide.  heat the mixture gently and test any gas  evolved with damp ph indicator paper. ..   [3] (c)  to the second portion of the solution, add  a few drops of dilute nitric acid and about 1 cm 3 of aqueous silver nitrate solution.   [2] (d)  to the third portion of the solution, add about 1 cm 3 of hydrogen peroxide solution.   add a spatula measure of starch to the mixture.   test the gas given off with a splint. ..  ..   [5] tests on the residueuse a spatula to transfer some of the residue  into a test-tube. (e)  add about 3 cm 3 of dilute hydrochloric acid  to the test-tube. test the gas given off.   to the solution add about 1 cm3 of dilute  sulfuric acid. ..  [3]   [1]",
            "7": "7 0620/52/m/j/15 \u00a9 ucles 2015 [turn over (f)   what conclusions can you draw about solid j?   ... .   ... ...  [2]  (g)  what conclusions can you draw about solid k?   ... .   ... .   ... ...  [2] [total: 19]",
            "8": "8 0620/52/m/j/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series.cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_s15_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test may/june 2015  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib15 06_0620_53/fp \u00a9 ucles 2015 *0106732732* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/53/m/j/15 \u00a9 ucles 20151  you are going to investigate what happens when four different solids, d, e, f and g, react with  excess dilute hydrochloric acid. the solids are all calcium compounds.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out four experiments.  (a) experiment 1   use a measuring cylinder to pour 30 cm3 of hydrochloric acid into the polystyrene cup supported  in the beaker provided. measure the temperature of the hydrochloric acid and record it in the table below.   add all of solid d to the hydrochloric acid and stir the mixture with the thermometer.   measure the temperature reached by the liquid mixture. record your result in the table. record  any observations.  observations   ..   ... ...  [1]   empty the polystyrene cup and rinse it with water.  (b) experiment 2   repeat experiment 1 using solid e.   record your results in the table.  (c) experiment 3   repeat experiment 1 using solid f.   record your results in the table.  (d) experiment 4   repeat experiment 1 using solid g but add 3-4 drops of universal indicator solution to the  hydrochloric acid before adding the solid. record your results in the table and note any observations below.  observations   ..   ... ...  [2]  (e)  complete the \ufb01 nal column in the table. experiment solid addedinitial temperature of acid / \u00b0ctemperature reached / \u00b0ctemperature difference / \u00b0c 1 d 2 e 3 f 4 g [4]",
            "3": "3 0620/53/m/j/15 \u00a9 ucles 2015 [turn over (f)  draw a labelled bar chart to show the results for experiments 1, 2, 3 and 4 on the grid below. 0temperature difference  / \u00b0c [4]   use the results and observations to answer the following questions.  (g) (i)   what type of chemical process occurs when solid d reacts with hydrochloric acid?   . ..  [1]  (ii)  what conclusion can you draw about solid d from your observations in experiment 1?   . ..  [1]",
            "4": "4 0620/53/m/j/15 \u00a9 ucles 2015 (h)  which experiment produced the largest temperature difference?   ... ...  [1]  (i)  explain your observations in experiment 4.   ... .   ... ...  [2]  (j)  predict the temperature of the solution in experiment 2 after 1 hour. explain your prediction.   ... .   ... ...  [2]  (k)  suggest and explain the effect on the results if experiment 2 was repeated using 60 cm3 of  hydrochloric acid.   ... .   ... ...  [2] [total: 20]",
            "5": "5 0620/53/m/j/15 \u00a9 ucles 2015 [turn over2  you are provided with solid h. solid h is a salt containing two cations and one anion.   carry out the following tests on solid h, recording all of your observations in the table.   conclusions must not be written in the table. tests observations tests on solid h (a)  describe the appearance of solid h.   [1] (b)  use a spatula to put half of solid h into a  hard-glass test-tube. heat the solid gently and then strongly.   test any gases given off with damp ph  indicator paper. ..  ..  [3] tests on a solution of h (c)  add about 10 cm3 of distilled water to  the rest of solid h, stopper and shake to  dissolve. describe the appearance of the solution.   [1] divide the solution into four equal portions in  four test-tubes. carry out the following tests.(d)  to the \ufb01 rst portion of the solution, add  aqueous sodium hydroxide using a teat pipette and shake the test-tube.   now add excess sodium hydroxide to the  test-tube.   heat the mixture gently and test any gases  given off.  [2]   [1]  ..  [2] (e)  to the second portion of the solution, add  excess aqueous ammonia solution.   [1]",
            "6": "6 0620/53/m/j/15 \u00a9 ucles 2015tests observations (f)  to the third portion of the solution, add a  few drops of dilute nitric acid and about 1 cm 3 of aqueous silver nitrate.   [1] (g)  to the fourth portion of the solution, add a  few drops of dilute nitric acid followed by about 1 cm 3 of barium nitrate solution. ..   [2]  (h)  what does test (b) tell you about the nature of solid h?   ... .   ... ...  [2]  (i)  what does test (f) tell you about the nature of solid h?   ... ...  [1]  (j)  what conclusions can you draw about the identity of solid h?   ... .   ... ...  [3] [total: 20]",
            "7": "7 0620/53/m/j/15 \u00a9 ucles 2015blank page",
            "8": "8 0620/53/m/j/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron( iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_s15_qp_61.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib15 06_0620_61/rp \u00a9 ucles 2015 *9821411450* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical may/june 2015  1 hour candidates answer on the question paper. no additional materials are required. modified languagecambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/61/m/j/15 \u00a9 ucles 20151  ethanol was reacted with hot acidi \ufb01 ed potassium manganate( vii) solution using the apparatus  below. ethanoic acid was formed. electric heaterethanol + acidified potassium manganate( vii)condenser  (a) (i)   complete the box to identify the piece of apparatus labelled. [1]  (ii)  label the arrows. [1]  (b) (i)   suggest and explain why an electric heater is used to heat this reaction and not a  bunsen burner.   .    . ..  [2]  (ii)  suggest why a condenser is necessary.   . ..  [1]  (c)  complete the table to show the difference in smell between ethanol and ethanoic acid. smell ethanol ethanoic acid [2] [total: 7]",
            "3": "3 0620/61/m/j/15 \u00a9 ucles 2015 [turn over2  electricity was passed through molten lead( ii) bromide using the apparatus shown. molten lead( ii) bromideelectrodeslight bulb   the formation of a brown gas was observed at the positive electrode.  (a)  give one other expected observation.   ... ...  [1]  (b) (i)  name a non-metal that could be used for the electrodes.   . ..  [1]  (ii)  suggest why iron is not used for the electrodes.   . ..  [1]  (c) (i)   name the brown gas formed.   . ..  [1]  (ii)  suggest the result of testing this gas with damp blue litmus paper.   . ..  [1]  (d)  name the product formed at the negative electrode.   ... ...  [1]  (e)  state one safety precaution that should be used when doing this experiment.   ... ...  [1] [total: 7]",
            "4": "4 0620/61/m/j/15 \u00a9 ucles 20153  a mixture of coloured dyes, m, was separated by chromatography. the dyes were insoluble in  water.   the chromatogram below shows the result of separating the mixture and the chromatography of  three known dyes 1, 2 and 3. 12 known dyes3m  (a)  on the diagram, label the base line (origin). [1]  (b)  name a solvent that could be used in this separation.   ... ...  [1]  (c)  how many dyes were there in the mixture, m?   ... ...  [1]  (d)  what are your conclusions about the identity of the dyes in the mixture, m?   ... .   ... .   ... ...  [3]  (e)  how could the reliability of the results be checked?   ... ...  [1] [total: 7]",
            "5": "5 0620/61/m/j/15 \u00a9 ucles 2015 [turn over4  a student investigated the reaction of aqueous sodium hydroxide with aqueous solutions of two  different acids, a and b.   two experiments were done.  (a) experiment 1   using a measuring cylinder, 50 cm3 of aqueous sodium hydroxide solution was poured into a  polystyrene cup. the initial temperature of the solution was measured.   a burette was \ufb01 lled with the solution of acid a to the 0.0 cm3 mark.   5.0 cm3 of acid a was added to the aqueous sodium hydroxide in the cup and the mixture  stirred.   the temperature of the solution was measured. another 5.0 cm3 of acid a was added to the  cup and the mixture stirred. the temperature of the mixture was measured.   more 5.0 cm3 portions of acid a were added to the cup until a total volume of 40.0 cm3 of acid  had been added. after each addition, the mixture was stirred and the temperature measured.",
            "6": "6 0620/61/m/j/15 \u00a9 ucles 2015 use the thermometer diagrams in the table to record the temperatures. 0.030 25 20 30 25 20 35 30 25 35 30 25 35 30 25 40 35 30 40 35 30 40 35 30 40 35 305.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0thermometer diagramvolume of acid a added  / cm3temperature of solution in polystyrene cup  / \u00b0c [3]",
            "7": "7 0620/61/m/j/15 \u00a9 ucles 2015 [turn over  the burette was emptied and rinsed with distilled water, and then with acid b. this acid was  discarded. the burette was then \ufb01 lled up to the 0.0 cm3 mark with acid b.  (b) experiment 2   experiment 1 was repeated using acid b instead of acid a.   use the thermometer diagrams in the table to record the temperatures. 0.030 25 20 40 35 30 45 40 35 45 40 35 40 35 3040 35 30 40 35 30 40 35 30 40 35 305.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0thermometer diagramvolume of acid b added  / cm3temperature of solution in polystyrene cup  / \u00b0c [3]",
            "8": "8 0620/61/m/j/15 \u00a9 ucles 2015 (c)  plot the results for experiments 1 and 2 on the grid and draw a smooth line graph for each  experiment.   clearly label your graphs. 01 0 2 0 volume of acid added  / cm330 4050 40 30 20temperature of solution  / \u00b0c [5]  (d)  use your graph  to estimate the temperature of the reaction mixture when 8.0 cm3 of acid b  were added to 50 cm3 of aqueous sodium hydroxide.   show clearly on the grid  how you worked out your answer.   ... ...  [2]  (e)  what type of chemical reaction, other than neutralisation, occurred when acid a reacted with  sodium hydroxide?   ... ...  [1]",
            "9": "9 0620/61/m/j/15 \u00a9 ucles 2015 [turn over (f)  why was the burette rinsed \ufb01 rstly with distilled water and then with acid b before starting  experiment 2?   ... .   ... ...  [2]  (g)  the solutions of acids a and b are the same concentration.  (i)  in which experiment was the maximum temperature change greater?   . ..  [1]  (ii)  suggest why the maximum temperature change was greater in this experiment.   .    . ..  [1]  (h)  describe one source of error in experiment 2. suggest one improvement to reduce this  source of error.  source of error  . ..  improvement  . . [2] [total: 20]",
            "10": "10 0620/61/m/j/15 \u00a9 ucles 20155  solid c was analysed. solid c was a mixture of salts containing aluminium ions, sulfate ions and  another cation (positive ion).   tests on solid c, and some of the observations, are in the table.   complete the observations in the table. tests observations tests on solid c (a)  appearance of solid c. white solid (b)  a little of solid c was heated gently  and then strongly.   the gas given off was tested with  damp ph indicator paper.condensation was formed at the top of the test-tube pungent gas, ph = 10 tests on a solution of c water was added to solid c to produce  an aqueous solution, solution c. (c)  drops of aqueous sodium hydroxide were added to solution c  using a teat pipette.   excess aqueous sodium hydroxide was then added to the mixture.   the mixture was boiled gently and any gases given off were tested. ..   [3] pungent gas, ph = 10 (d)  excess aqueous ammonia was  added to solution c. ..   [1] (e)  a few drops of dilute nitric acid and aqueous silver nitrate were added to solution c. ..   [1] (f)  a few drops of dilute nitric acid and barium nitrate solution were added to solution c. ..   [2]",
            "11": "11 0620/61/m/j/15 \u00a9 ucles 2015 [turn over (g)  what does the formation of condensation in test (b) tell you about the nature of solid c?   ... ...  [1]  (h)  what does test (e) tell you about the nature of solid c?   ... ...  [1]  (i) (i)  name the gas given off in test (b).   . ..  [1]  (ii)  what is your conclusion about the identity of the other cation in solid c?   . ..  [1] [total: 11]",
            "12": "12 0620/61/m/j/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series.cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.6  a catalyst is a substance that speeds up the rate of a chemical reaction and remains unchanged  at the end of the reaction.   hydrogen peroxide solution, h2o2, breaks down to form oxygen. this decomposition is very slow  if a catalyst is not used.   plan an investigation to show that copper( ii) oxide is a suitable catalyst for this reaction.   you can use aqueous hydrogen peroxide and common laboratory apparatus.  step 1  show that copper( ii) oxide catalyses the decomposition of hydrogen peroxide and  measure the rate of the reaction.   ...    ...    ...    ...    ...    ...    ...    ...   step 2  show that the copper( ii) oxide is unchanged at the end of the decomposition.   ...    ...    ...    ...    ...    ...    ...  [total: 8]"
        },
        "0620_s15_qp_62.pdf": {
            "1": "this document consists of 11 printed pages and 1 blank page. [turn overib15 06_0620_62/rp \u00a9 ucles 2015 *0859698315* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/62   paper 6 alternative to practical may/june 2015  1 hour candidates answer on the question paper. no additional materials are required. modified language cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/m/j/15 \u00a9 ucles 20151  a student did an experiment to measure the energy produced by burning ethanol.   the apparatus used is shown. boiling tube 20 cm3 water spirit burner ethano l   the ethanol was burned for one minute. the temperature of the water was then measured and  recorded.  (a)  complete the boxes to name the pieces of apparatus. [2]  (b)  give three other measurements the student should have taken.  1  .  2  .  3  . [3]  (c)  the experiment was repeated using 40 cm3 of water. what effect would this have on the  results?   ..   [1]  (d)  another student did this experiment using a copper can instead of a boiling tube.   give one advantage of this change to the apparatus.   ..   [1] [total: 7]",
            "3": "3 0620/62/m/j/15 \u00a9 ucles 2015 [turn over2  a student prepared some crystals of chromium( iii) nitrate, cr(no3)3.6h2o.   the following extract was taken from his practical notes. making chromium( iii) nitrate crystals step 1    i poured 50 cm3 of acid into a beaker. solid chromium( iii) oxide was  then added a little at a time and the mixture stirred. step 2    when no more chromium( iii) oxide reacted i separated the mixture  and collected the solution in an evaporating dish. step 3    i boiled the solution strongly for ten minutes.  (a)  name the acid used in this preparation.   ..   [1]  (b)  what would be used in step 1 to  (i)  add the chromium( iii) oxide to the acid,   ...   [1]  (ii)  stir the mixture?   ...   [1]  (c)  name the separation method used in step 2.   ..   [1]  (d) (i)  suggest what was left in the evaporating dish at the end of step 3.   ...   [1]  (ii)  how should the student have changed the method in step 3 to obtain pure, dry crystals  of chromium( iii) nitrate?   .   .   .   ...   [3] [total: 8]",
            "4": "4 0620/62/m/j/15 \u00a9 ucles 20153  three bottles of liquid have lost their labels. the liquids are known to be:  \u2022 aqueous potassium hydroxide,  \u2022 octane,  \u2022 pure water.   outline tests you would do to identify and distinguish the liquid in each bottle. liquid test result aqueous potassium hydroxide octane pure water [6] [total: 6]",
            "5": "5 0620/62/m/j/15 \u00a9 ucles 2015 [turn over4  a student investigated the rate of reaction between hydrochloric acid and aqueous sodium  thiosulfate. when these chemicals react they form a precipitate which makes the solution go cloudy. the formation of this precipitate can be used to show how fast the reaction proceeds.   five experiments were done using the apparatus shown below. aqueous sodium thiosulfat eeye 10 cm3 of hydrochloric acid 250  cm3 conical flas k printed shee t  (a) experiment 1   using a measuring cylinder, 50 cm3 of aqueous sodium thiosulfate was poured into a conical  flask. the conical flask was placed on a printed sheet of paper.   10 cm3 of the hydrochloric acid was added to the solution in the conical flask and the stop  clock started.   the time taken for the printed words to disappear from view was measured.  (b) experiment 2   using a measuring cylinder, 40 cm3 of aqueous sodium thiosulfate was poured into a conical  flask, followed by 10 cm3 of distilled water. the conical flask was placed on the printed sheet.   10 cm3 of the hydrochloric acid was added to the solution in the conical flask and the stop  clock started.   the time taken for the printed words to disappear from view was measured.  (c) experiment 3   experiment 2 was repeated using 35 cm3 of aqueous sodium thiosulfate and 15 cm3 of  distilled water.  (d) experiment 4   experiment 2 was repeated using 30 cm3 of aqueous sodium thiosulfate and 20 cm3 of  distilled water.  (e) experiment 5   experiment 2 was repeated using 20 cm3 of aqueous sodium thiosulfate and 30 cm3 of  distilled water.",
            "6": "6 0620/62/m/j/15 \u00a9 ucles 2015 (f)  use the stop clock diagrams to record the times in the table.   complete the table. 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5seconds minutesexperiment number 1stop clock diagramtime for printed words to disappear  / svolume of aqueous sodium thiosulfate  / cm3volume of distilled water  / cm3 2 3 4 5 [4]",
            "7": "7 0620/62/m/j/15 \u00a9 ucles 2015 [turn over (g)  plot the results on the grid and draw a smooth line graph. 180 160 140120 100 80 60 40 20 0 0 10 20 30 volume of aqueous sodium thiosulfate  / cm340 50 60time for printed wordsto disappear  / s [3]  (h) (i)  from your graph, deduce the time for the printed words to disappear if experiment 2  was repeated using 25 cm3 of aqueous sodium thiosulfate and 25 cm3 of distilled water.   show clearly on the grid  how you worked out your answer.   ...   [3]  (ii)  sketch on the grid  the curve you would expect if the experiments were repeated at a  lower temperature. label this curve \u2018lower temperature\u2019. [1]",
            "8": "8 0620/62/m/j/15 \u00a9 ucles 2015 (i) (i)  in which experiment was the rate of reaction greatest?   ...   [1]  (ii)  explain why the rate of reaction was greatest in this experiment.   .   ...   [1]  (j)  a student did a sixth experiment using 60 cm3 of aqueous sodium thiosulfate.   why would this not be an appropriate volume to use in this series of experiments?      ..   [2]  (k)  suggest and explain the effect of  (i)  using a burette to measure the volume of the hydrochloric acid,   .   ...   [2]  (ii)  using a 100  cm3 conical flask.   .   ...   [2] [total: 19]",
            "9": "9 0620/62/m/j/15 \u00a9 ucles 2015 [turn over5  a mixture of two salts, j and k, was analysed. j was ammonium iodide which is water soluble  and k is insoluble.   the tests on the mixture, and some of the observations are in the following table.   complete the observations in the table. tests observations (a)  appearance of the mixture. white solid distilled  water  was added  to the mixture.   the mixture was shaken and filtered. tests on the filtratethe solution was divided into two  equal portions in two test-tubes. (b)  to the first portion of the solution,  aqueous sodium hydroxide was  added. the mixture was heated  gently and the gas evolved was tested with ph indicator paper. ..   [2] (c)  to the second portion of the  solution, dilute nitric acid and aqueous silver nitrate solution were added. ..   [2] tests on the residue (d)  dilute  hydrochloric  acid was added  to the residue in a test-tube. the  gas given off was tested.   dilute sulfuric acid was added to the solution formed.rapid effervescence limewater turned milky white precipitate formed  (e)  what is the ph value of the gas given off in test (b)?   ..   [1]  (f)  identify the gas given off in test (d).   ..   [1]  (g)  what are your conclusions about solid k?      ..   [2] [total: 8]",
            "10": "10 0620/62/m/j/15 \u00a9 ucles 20156  concentrated hydrochloric acid was electrolysed. hydrogen electrodesconcentrate d hydrochloric acid + \u2013   hydrogen gas formed at the cathode (negative electrode).  (a)  name a suitable metal to use for the electrodes.   ..   [1]  (b)  why does hydrogen form at the negative electrode?   ..   [1]  (c) (i)  identify the gas given off at the anode (positive electrode).   ...   [1]  (ii)  give a test for this gas.  test  ..    result  ... [2]  (d)  suggest why the volume of gas formed at the positive electrode is less than the volume of  hydrogen.   ..   [1] [total: 6]",
            "11": "11 0620/62/m/j/15 \u00a9 ucles 2015 [turn over7 tonic water   tonic water is a solution containing citric acid. the concentration of the acid can be determined  by reaction with aqueous potassium hydroxide solution.   plan an investigation to show which of two different brands of colourless tonic water, tastyton and  slimton, contains the highest concentration of citric acid.   you can use common laboratory apparatus and chemicals.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "12": "12 0620/62/m/j/15 \u00a9 ucles 2015blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. "
        },
        "0620_s15_qp_63.pdf": {
            "1": "this document consists of 11 printed pages and 1 blank page. [turn overib15 06_0620_63/3rp \u00a9 ucles 2015 *0474927560* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical may/june 2015  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/63/m/j/15 \u00a9 ucles 20151  liquid paraf \ufb01 n oil was heated using the apparatus shown. the vapour was broken down by being  passed over very hot small pieces of broken tile. the gas collected was a mixture of alkenes and  hydrogen. broken tile mixture of gasesliquid paraffin on mineral wool water  (a)  complete the box to name the apparatus used. [1]  (b)  indicate with two arrows where heat was applied. [2]  (c) (i)   why were small  pieces of broken tile used?   . ..  [1]  (ii)  what was the purpose of the mineral wool?   . ..  [1]  (d)  name the process where long-chain hydrocarbons are broken down by heat.   ... ...  [1]  (e)  suggest the effect of passing the mixture of hydrogen and alkenes through bromine water.   ... .   ... ...  [1] [total: 7]",
            "3": "3 0620/63/m/j/15 \u00a9 ucles 2015 [turn over2  a student investigated the rate of reaction between zinc and excess hydrochloric acid, at 20 \u00b0c.   2 g of zinc powder was added to 50 cm3 of dilute hydrochloric acid. dilute hydrochloric acidzincgas syringe   the volume of hydrogen released was measured every 30 seconds.  (a)  use the gas syringe diagrams to record the volumes in the table. 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40 01 02 03 0 50 60 40time  / s 0 306090 120150180210gas syringe diagram volume of hydrogen  / cm3 [3]",
            "4": "4 0620/63/m/j/15 \u00a9 ucles 2015 (b)   plot the points on the grid. draw a smooth line graph. 70 60504030 20 10 0 0 3 06 09 0 1 2 0 time  / svolume of hydrogen/  cm3 150 180 210 [4]  (c) (i)   at which time interval does the point appear to be inaccurate?   . ..  [1]  (ii)  use your graph  to \ufb01 nd the volume of gas that would be expected at this time.   . ..  [2]  (d)  the experiment was repeated but the hydrochloric acid was cooled to 5 \u00b0c before adding the  zinc.  (i)  how could the hydrochloric acid be cooled?   . ..  [1]  (ii)  sketch on the grid  the graph you would expect for the results at 5 \u00b0c. label your graph  \u2018lower temperature\u2019. [2] [total: 13]",
            "5": "5 0620/63/m/j/15 \u00a9 ucles 2015 [turn over3  an investigation into the rusting of iron \ufb01 lings was carried out using damp iron \ufb01 lings in an inverted  boiling tube. 150  mmair before rustingdampiron filings tap water125  mmair afterrustingdampiron filings tap wate r  (a)  after one week the colour of the iron \ufb01 lings changed from grey to . [1]  (b) (i)   why did the water rise up the boiling tube?   . ..  [1]  (ii)  use the information on the diagram to work out the percentage decrease in the volume of  the air in the boiling tube after one week.   .    . ..  [2]  (c)  what would be the effect if this experiment were repeated using boiled distilled water instead  of tap water?   ... ...  [1] [total: 5]",
            "6": "6 0620/63/m/j/15 \u00a9 ucles 20154  a student investigated the temperature changes when four different solids, d, e, f and g, reacted  with excess dilute hydrochloric acid. the solids were all calcium compounds.   four experiments were carried out.  (a) experiment 1   using a measuring cylinder, 30 cm3 of hydrochloric acid was poured into a polystyrene cup.  the temperature of the hydrochloric acid was measured.   2 g of solid d was added to the hydrochloric acid and the mixture stirred with a thermometer.   the temperature reached by the liquid mixture was measured.   observations were recorded.  observation:  rapid effervescence.   the polystyrene cup was emptied and rinsed with distilled water.  (b) experiment 2   experiment 1 was repeated using solid e.  (c) experiment 3   experiment 1 was repeated using solid f.  (d) experiment 4   experiment 1 was repeated using solid g but universal indicator solution was added to the  hydrochloric acid before adding the solid. observations were recorded.  observation:   the red colour of the liquid, ph 1, changed colour to orange then yellow, ph 6.  (e)  use the thermometer diagrams to record all of the temperatures in the table. complete the \ufb01 nal  column in the table. 1 2 3 4experimentinitial temperature of acid  / \u00b0cthermometer diagramthermometer diagramtemperature reached  / \u00b0ctemperature change  / \u00b0c 30 25 2030 25 20 30 25 2060 55 50 30 25 2025 20 15 30 25 2050 45 40 [3]",
            "7": "7 0620/63/m/j/15 \u00a9 ucles 2015 [turn over (f)  draw a labelled bar chart to show the results of the experiments 1, 2, 3 and 4. 0temperature change  / \u00b0c [4]  (g)  use the results and observations to answer the following questions.  (i)  what type of chemical process occurred when solid d reacted with hydrochloric acid?   . ..  [1]  (ii)  what conclusion can you draw about solid d from the observations in experiment 1?   . ..  [1]  (h)  which experiment produced the largest temperature change?   ... ...  [1]",
            "8": "8 0620/63/m/j/15 \u00a9 ucles 2015 (i)  explain the observations in experiment 4.   ... .   ... ...  [2]  (j)  predict the temperature of the solution in experiment 2 after 1 hour. explain your prediction.   ... .   ... ...  [2]  (k)  suggest and explain the effect on the results if experiment 2 was repeated using 60 cm3 of  hydrochloric acid.   ... .   ... ...  [2]  (l)  suggest a possible source of error in this experiment. identify a change in apparatus which  would reduce this error.  source of error  . ..  change to apparatus  . . [2] [total: 18]",
            "9": "9 0620/63/m/j/15 \u00a9 ucles 2015 [turn over5  solid h was analysed. solid h was a salt containing iron( iii) ions, sulfate ions and one other cation  (positive ion).   the tests on solid h, and some of the observations are in the following table.   complete the observations in the table. tests observations tests on solid h (a)  appearance of solid h. pale yellow solid (b)  solid h was heated gently and then  strongly.   the gas given off was tested with  ph indicator paper.condensation formed at the top of the test-tube pungent gas ph paper turned blue-green, ph 10 tests on a solution of h water was added to solid h to produce  an aqueous solution, solution h. (c)  drops of aqueous sodium  hydroxide were added to 1 cm3  of solution h and the test-tube  shaken.   excess sodium hydroxide was then  added to the test-tube.   the mixture was heated gently and  the gas given off was tested...   [2] ..   [1] pungent gas, red litmus paper turned blue (d)  excess aqueous ammonia solution  was added to solution h. ..   [1] (e)  dilute nitric acid and aqueous silver  nitrate were added to solution h. ..   [1] (f)  dilute nitric acid and barium nitrate  solution were added to solution h...   [2]",
            "10": "10 0620/63/m/j/15 \u00a9 ucles 2015 (g)  what does the formation of condensation in test (b) tell you about the nature of solid h?   ... .   ... ...  [1]  (h)  what does test (e) tell you about the nature of solid h?   ... ...  [1]  (i) (i)  name the gas given off in test (c).   . ..  [1]  (ii)   what conclusions can you draw about the identity of the other cation in solid h?   . ..  [1] [total: 11]",
            "11": "11 0620/63/m/j/15 \u00a9 ucles 2015 [turn over6 burnable ice (methane hydrate)   methane hydrate is ice which contains trapped methane gas. methane is released when the ice  melts and is a useful fuel.   plan an investigation to \ufb01 nd the volume of methane gas trapped in 1 kg of this ice.   you are provided with a lump of the ice weighing between 100 g and 200 g and common laboratory  apparatus.   you may include a diagram in your answer.   ...    ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 6]",
            "12": "12 0620/63/m/j/15 \u00a9 ucles 2015blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        },
        "0620_w15_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern i reland as a cambridge international level 1/level 2 certificat e.  this document consists of 17 printed pages and 3 blank pages.  ib15 11_0620_11/5rp  \u00a9 ucles 2015 [turn over       *0290816641* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice  october/november 2015       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2015 0620/11/o/n/15  1 diagrams x, y and z represent the three states of matter.    x y z      which change occurs during boiling?  a x to y b y to z c z to x d z to y    2 p, q, r and s are pieces of apparatus.    pq r s 50 cm3 50 cm325 cm3 100  cm3     which row describes the correct apparatus for the measurement made?    apparatus measurement made  a p the volume of acid added to alkali in a titration  b q 1  cm3 of acid to add to calcium carbonate in a rate-determining experiment  c r 75  cm3 of a gas given off in a rate-determining experiment  d s 20  cm3 of alkali for use in a titration    3 which statement about atoms is correct?  a atoms contain protons and electrons in the nucleus.  b neutrons are negatively charged.  c protons are positively charged.  d the nucleon number is the number of neutrons.     ",
            "3": "3  \u00a9 ucles 2015 0620/11/o/n/15 [turn over  4 which diagram correctly shows the ions present in the compound potassium fluoride?    e ee ee eeee e e ee ee ee ee ee eee e ee ee ee ee eeee e e ee ee ee ee ee eee e ee eea k+ b k\u2013 c k+ d k\u2013f\u2013 f+key = nucleus = electronee ee eeee e e ee ee ee ee f\u2013 ee eee e ee ee+\u2013 ee ee eeee e e ee ee ee ee f+ ee eee e ee ee\u2013+ +\u2013 +\u2013      ",
            "4": "4  \u00a9 ucles 2015 0620/11/o/n/15  5 what do the nuclei of h1 1 hydrogen atoms contain?  a electrons and neutrons  b electrons and protons  c neutrons only  d protons only     6 the electronic structures of atoms x and y are shown.    x y     x and y form a covalent compound.    what is its formula?  a xy 5 b xy 3 c xy d x 3y     7 two atoms of magnesium, mg, react with one molecule of oxygen, o 2.    what is the formula of the product?  a mgo b mgo 2 c mg 2o d mg 2o2     8 which row describes the electrolysis of molten potassium bromide?     product at anode product at cathode  a bromine hydrogen  b bromine potassium  c hydrogen bromine  d potassium bromine    ",
            "5": "5  \u00a9 ucles 2015 0620/11/o/n/15 [turn over  9 the diagram shows a section of an overhead power cable.    aluminiumsteel ceramic     which statement explains why a particular substance is used?  a aluminium has a low density and is a good conductor of electricity.  b ceramic is a good conductor of electricity.  c steel can rust in damp air.  d steel is more dense than aluminium.      10 which reaction is endothermic?  a acid neutralising alkali causing a temperature increase  b adding magnesium to hydrochloric acid  c calcium carbonate decomposing when heated  d combustion of fossil fuels     ",
            "6": "6  \u00a9 ucles 2015 0620/11/o/n/15  11 solid hydrated sodium carbonate was added to solid citric acid.    the mixture was stirred and the temperature recorded every 10 seconds.    the results are shown on the graph:    25 201510 50temperature /  \u00b0c 0 2 04 06 0 time  / s80 100     which row describes the reaction?     reaction type energy change  a neutralisation endothermic  b neutralisation exothermic  c thermal decomposition endothermic  d thermal decomposition exothermic     12 the effect of temperature on the rate of the r eaction between marble chips and hydrochloric acid  can be investigated by measuring the production of carbon dioxide.    which item of equipment is not required for the investigation?  a condenser  b gas syringe  c stopclock  d thermometer    ",
            "7": "7  \u00a9 ucles 2015 0620/11/o/n/15 [turn over  13 the element vanadium, v, forms several oxides.    in which change is oxidation taking place?  a vo 2 \u2192 v 2o3  b v2o5 \u2192 vo 2  c v2o3 \u2192 vo  d v2o3 \u2192 v 2o5      14 some crystals of hydrated cobalt( ii) chloride are heated in a test-tube until no further change is  observed.     the test-tube is allowed to cool and a few drops of water are then added to the contents.    which colours are observed?     before  heating after  heating after adding  water  a blue pink blue  b blue white blue  c pink blue pink  d white blue white     15 the diagram shows a simplified form of the periodic table:    wx y z     which elements will form an acidic oxide?  a w and z b w only c x and y only d y only     ",
            "8": "8  \u00a9 ucles 2015 0620/11/o/n/15  16 a white solid is insoluble in water.     when it is added to hydrochloric acid, bubbles of gas are formed.    adding aqueous ammonia to the solution formed gives a white precipitate. adding excess  aqueous ammonia causes the precipitate to re-dissolve.    what is the white solid?  a aluminium nitrate  b ammonium nitrate  c calcium carbonate  d zinc carbonate     17 which property is not characteristic of a base?  a it reacts with a carbonate to form carbon dioxide.  b it reacts with an acid to form a salt.  c it reacts with an ammonium salt to form ammonia.  d it turns universal indicator paper blue.    18 four stages in the preparation of a salt from an acid and a solid metal oxide are listed.    1 add excess solid.  2 evaporate half the solution and leave to cool.  3 filter to remove unwanted solid.  4 heat the acid.    in which order should the stages be carried out?  a 1 \u2192 3 \u2192 4 \u2192 2  b 2 \u2192 1 \u2192 3 \u2192 4  c 4 \u2192 1 \u2192 3 \u2192 2  d 4 \u2192 2 \u2192 1 \u2192 3     ",
            "9": "9  \u00a9 ucles 2015 0620/11/o/n/15 [turn over  19 which statements about group i and group vii elements are correct?    1 in group i, lithium is more reactive than potassium.  2 in group vii, chlorine is more reactive than fluorine.     statement 1 statement 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     20 the periodic table lists all the known elements.    elements are arranged in order of ...  1 ... number.    the melting points of group i elements ...  2 ... down the group.    the melting points of group vii elements ...  3 ... down the group.    which words correctly complete the gaps 1, 2 and 3?     1 2 3  a nucleon decrease increase  b nucleon increase decrease  c proton decrease increase  d proton increase decrease    21 the table gives information about four elements.    which element is a transition metal?     electrical  conductivity density in  g  / cm3 melting point  in \u00b0c  a good 0.97 98  b good 7.86 1535  c poor 2.33 1410  d poor 3.12 \u20137    ",
            "10": "10  \u00a9 ucles 2015 0620/11/o/n/15  22 the group 0 elements are unreactive.    the gas used to fill balloons is ...  x... .    this gas is unreactive because it has ...  y... electrons in its outermost shell.    which words correctly complete gaps x and y?     x y  a argon eight  b argon two  c helium eight  d helium two     23 which diagram shows the structure of an alloy?    \u2013\u2013 \u2013\u2013 \u2013\u2013 \u2013\u2013\u2013\u2013 \u2013 \u2013\u2013\u2013+++++++++++ + +a cb d      ",
            "11": "11  \u00a9 ucles 2015 0620/11/o/n/15 [turn over  24 the diagrams show what happens when three different metals are added to water.    x y zbubbles of gasflame     what are x, y and z?     x y z  a calcium copper potassium  b copper calcium potassium  c potassium calcium copper  d potassium copper calcium     25 which metal would be suitable for all of the following uses?  \u007f making aircraft bodies  \u007f making food containers  \u007f making overhead power cables  a aluminium  b brass  c mild steel  d pure iron    26 iron is extracted from its ore (hematite) in the blast furnace.    which gas is produced as a waste product?  a carbon dioxide  b hydrogen  c nitrogen  d oxygen     ",
            "12": "12  \u00a9 ucles 2015 0620/11/o/n/15  27 which statements about water are correct?    1 household water may contain salts in solution.  2 water for household use is filtered to remove soluble impurities.  3 water is treated with chlorine to kill bacteria.  4 water is used in industry for cooling.    a 1, 2, 3 and 4   b 1, 2 and 3 only  c 1, 3 and 4 only  d 2, 3 and 4 only      28 which is a use of oxygen?  a as the gas in a lamp  b to react with ethene to form ethanol  c to react with methane in a bunsen burner  d to react with hematite to form iron      29 carbon monoxide is an air pollutant produced when petrol is burned in a car engine.    why is carbon monoxide considered to be an air pollutant?  a it causes climate change.  b it causes the corrosion of buildings.  c it is a significant greenhouse gas.  d it is poisonous.     30 fertilisers are mixtures of different compounds used to increase the growth of crops.   which pair of substances contains the three essential elements for plant growth?  a ammonium nitrate and calcium phosphate  b ammonium nitrate and potassium chloride  c ammonium phosphate and potassium chloride  d potassium nitrate and calcium carbonate     ",
            "13": "13  \u00a9 ucles 2015 0620/11/o/n/15 [turn over  31 which process does not produce carbon dioxide?  a complete combustion of a fossil fuel  b fermentation  c reaction of an alkali with a carbonate  d respiration      32 the apparatus shown is set up and left for a week.    damp iron wool air water     which diagram shows the level of the water at the end of the week?    a b c d      33 carbon dioxide and methane both contribute to climate change.   which process produces both gases?  a complete combustion of natural gas  b farming cattle  c heating calcium carbonate  d respiration    ",
            "14": "14  \u00a9 ucles 2015 0620/11/o/n/15  34 a student is asked to draw a diagram showing the uses of limestone.    limestone making  cement making lime added, with hematite,  to a blast furnace 1 2  3      which numbered lines show a correct use of limestone?  a 1, 2 and 3  b 1 and 2 only  c 1 and 3 only  d 2 and 3 only     35 the diagram shows the structure of a simple hydrocarbon and the products of two of its  reactions.    br br ch hc cchhh hhh   dibromoethane ethanol ethane13 2 hch hcohh hbromine steam     which structures are named correctly?     structure   1 2 3  a \u0013 \u0013 \u0017  b \u0013 \u0017 \u0013  c \u0017 \u0013 \u0013  d \u0017 \u0013 \u0017    ",
            "15": "15  \u00a9 ucles 2015 0620/11/o/n/15 [turn over  36 which row describes the formation of a polymer?     monomer polymer  a ethane poly(ethane)  b ethane poly(ethene)  c ethene poly(ethane)  d ethene poly(ethene)     37 what is not the correct use for the fraction named?   name of fraction use  a fuel oil making waxes  b gas oil diesel engines  c kerosene jet fuel  d naphtha fraction making chemicals    38 ethanol can be formed by    1 fermentation  2 reaction between steam and ethene    which of these processes uses a catalyst?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "16": "16  \u00a9 ucles 2015 0620/11/o/n/15  39 which homologous series is not represented in the compounds shown below?    h ch hhhhh c c h h ch h hh oc c o hh ch hh ohhh c c h h ch hhc hhhh h c c h     a alcohols  b alkanes  c alkenes  d carboxylic acids     40 alkenes are manufactured by cracking hydrocarbons obtained from petroleum.    hydrocarbon p obtained from petroleumhydrocarbon qcracking     which row describes the size of the molecules in hydrocarbons p and q and the effect of q on  aqueous bromine?   size of p  molecules size of q  molecules effect of q  on aqueous bromine  a large small decolourises  b large small no effect  c small large decolourises  d small large no effect     ",
            "17": "17  \u00a9 ucles 2015 0620/11/o/n/15  blank page ",
            "18": "18  \u00a9 ucles 2015 0620/11/o/n/15  blank page ",
            "19": "19  \u00a9 ucles 2015 0620/11/o/n/15  blank page",
            "20": "20    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    \u00a9 ucles 2015 0620/11/o/n/15   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w15_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib15 11_0620_12/3rp  \u00a9 ucles 2015 [turn over       *1006769290* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice  october/november 2015       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2015 0620/12/o/n/15  1 which change of state takes place during evaporation?  a gas to liquid  b liquid to gas  c liquid to solid  d solid to gas      2 the diagram shows apparatus being used to demonstrate how the rate of a chemical reaction  changes with temperature.    reaction mixturemeasuring cylinder tank     which statement must be correct?  a the reaction is endothermic.  b the reaction is exothermic.  c the reaction produces a gas.  d the reaction produces an acid.     ",
            "3": "3  \u00a9 ucles 2015 0620/12/o/n/15 [turn over  3 the table shows the nucleon number and the number of neutrons in one atom of isotopes w, x,  y and z.    isotope nucleon  number number of  neutrons  w 35 18  x 37 20  y 39 20  z 40 22    which statement about w, x, y and z is correct?  a w and x are isotopes of the same element.  b x and y are isotopes of elements in the same group of the periodic table.  c y and z are isotopes of elements in the same period of the periodic table.  d z has a higher proton number than y.      4 compound x melts at 801  \u00b0c and is a good electrical conductor when dissolved in water.    compound y boils at 77  \u00b0c, is insoluble in water and is a non-conductor of electricity.    which type of bonding is present in x and in y?     x y  a covalent covalent  b covalent ionic  c ionic covalent  d ionic ionic      5 what do the nuclei of h1 1 hydrogen atoms contain?  a electrons and neutrons  b electrons and protons  c neutrons only  d protons only     ",
            "4": "4  \u00a9 ucles 2015 0620/12/o/n/15  6 the electronic structures of atoms x and y are shown.    x y     x and y form a covalent compound.    what is its formula?  a xy 5 b xy 3 c xy d x 3y      7 the relative atomic mass of chlorine is 35.5.    when calculating relative atomic mass, which particle is the mass of a chlorine atom compared  to?  a a neutron  b a proton  c an atom of carbon-12  d an atom of hydrogen-1     8 the diagram shows the electrolysis of concentrated hydrochloric acid and concentrated aqueous  sodium chloride using carbon electrodes.    +\u2013 +\u2013 electrode 2 electrode 1 concentrated hydrochloric acidelectrode 4 electrode 3 concentrated aqueous sodium chloride    at which electrode(s) is hydrogen produced?  a electrode 1 only  b electrodes 1 and 3  c electrode 2 only  d electrodes 2 and 4 ",
            "5": "5  \u00a9 ucles 2015 0620/12/o/n/15 [turn over  9 the diagram shows a section of an overhead power cable.    aluminiumsteel ceramic     which statement explains why a particular substance is used?  a aluminium has a low density and is a good conductor of electricity.  b ceramic is a good conductor of electricity.  c steel can rust in damp air.  d steel is more dense than aluminium.      10 hydrogen can be used as a fuel.    which properties of hydrogen would be advantages and which would be disadvantages?    1 hydrogen is expensive to produce.  2 hydrogen reacts exothermically with oxygen. 3 when hydrogen burns, a greenhouse gas is not formed.   advantages disadvantages  a 1 2 and 3  b 1 and 2 3  c 1 and 3 2  d 2 and 3 1     11 which row correctly describes whether the reaction is exothermic or endothermic?     reaction exothermic endothermic  a calcium carbonate \u2192 calcium oxide + carbon dioxide \u0013 \u0017  b carbon + oxygen \u2192 carbon dioxide \u0013 \u0017  c methane + oxygen \u2192 carbon dioxide + water \u0017 \u0013  d sodium + water \u2192 sodium hydroxide + hydrogen \u0017 \u0013   ",
            "6": "6  \u00a9 ucles 2015 0620/12/o/n/15  12 the diagram shows four experiments in which equal volumes of aqueous acid (all in an excess)  are added to equal masses of metal. both acids have the same concentration.    in which experiment has the metal completely reacted in the shortest time?    hc l copper granulesa hno3 copper powderb hc l zinc granulesc hno3 zinc powderd       13 the element vanadium, v, forms several oxides.    in which change is oxidation taking place?  a vo 2 \u2192 v 2o3  b v2o5 \u2192 vo 2  c v2o3 \u2192 vo  d v2o3 \u2192 v 2o5     14 which reaction is not a reversible reaction?  a combustion of alkanes  b hydration of anhydrous copper( ii) sulfate  c melting lead( ii) bromide  d thermal decomposition of hydrated cobalt( ii) chloride      15 the reaction between magnesium and carbon dioxide is represented by the following equation.    2mg  +  co 2  \u2192  2mgo  +  c    which statement describes what happens in this reaction?  a carbon is oxidised.  b magnesium is reduced.  c neither oxidation nor reduction happens.  d the carbon in carbon dioxide is reduced.     ",
            "7": "7  \u00a9 ucles 2015 0620/12/o/n/15 [turn over  16 which element forms an acidic oxide?    a bc d      17 which property is not characteristic of a base?  a it reacts with a carbonate to form carbon dioxide.  b it reacts with an acid to form a salt.  c it reacts with an ammonium salt to form ammonia.  d it turns universal indicator paper blue.    18 a sting from insect x has a ph of 6 and a sting from insect y has a ph of 8.    the table shows the ph of four substances.    substance ph  hydrochloric acid   1  sodium hydrogen carbonate   8  sodium hydroxide 14  vinegar   5    which substances are used to treat the two stings?     x y  a hydrochloric acid sodium hydroxide  b sodium hydrogen carbonate vinegar  c sodium hydroxide hydrochloric acid  d vinegar sodium hydrogen carbonate    ",
            "8": "8  \u00a9 ucles 2015 0620/12/o/n/15  19 a salt is produced in each of the following reactions.    p magnesium + dilute hydrochloric acid  q zinc oxide + dilute sulfuric acid  r sodium hydroxide + dilute hydrochloric acid  s copper carbonate + dilute sulfuric acid    which statements about the products of the reactions are correct?    1 a flammable gas is produced in reaction p.  2 water is formed in all reactions.  3 all the salts formed are soluble in water.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      20 the table shows the symbols of three metals with names that begin with the letter c.    which row correctly shows the melting point of the metals?     co cr cs  a high high high  b high high low  c low low high  d low low low      21 the table gives information about four elements.    which element is a transition metal?     electrical  conductivity density in  g / cm3 melting point  in \u00b0c  a good 0.97 98  b good 7.86 1535  c poor 2.33 1410  d poor 3.12 \u20137     ",
            "9": "9  \u00a9 ucles 2015 0620/12/o/n/15 [turn over  22 the diagram shows elements w, x, y and z in a section of the periodic table.    x yzw     which statement about the reactivity of the elements is correct?  a x is more reactive than y, and w is more reactive than z.  b x is more reactive than y, and z is more reactive than w.  c y is more reactive than x, and w is more reactive than z.  d y is more reactive than x, and z is more reactive than w.     23 which two elements make up mild steel?  a aluminium and magnesium  b copper and zinc  c iron and carbon   d tin and lead    24 the diagrams show what happens when three different metals are added to water.    x y zbubbles of gasflame     what are x, y and z?     x y z  a calcium copper potassium  b copper calcium potassium  c potassium calcium copper  d potassium copper calcium   ",
            "10": "10  \u00a9 ucles 2015 0620/12/o/n/15  25 which substances do not react together?  a calcium  +  water  b copper  +  dilute hydrochloric acid  c sodium  +  water  d zinc  +  dilute hydrochloric acid      26 iron is extracted from hematite in a blast furnace.    which reaction increases the temperature in the blast furnace to over 1500  \u00b0c?  a calcium carbonate \u2192 calcium oxide + carbon dioxide  b calcium oxide + silicon dioxide \u2192 calcium silicate  c carbon + oxygen \u2192 carbon dioxide  d carbon dioxide + carbon \u2192 carbon monoxide     27 which statements about water are correct?    1 household water may contain salts in solution.  2 water for household use is filtered to remove soluble impurities. 3 water is treated with chlorine to kill bacteria. 4 water is used in industry for cooling.    a 1, 2, 3 and 4   b 1, 2 and 3 only  c 1, 3 and 4 only  d 2, 3 and 4 only     28 which gas is a pollutant of the air?  a argon  b carbon dioxide  c nitrogen  d sulfur dioxide    ",
            "11": "11  \u00a9 ucles 2015 0620/12/o/n/15 [turn over  29 carbon monoxide is an air pollutant produced when petrol is burned in a car engine.    why is carbon monoxide considered to be an air pollutant?  a it causes climate change.  b it causes the corrosion of buildings.  c it is a significant greenhouse gas.  d it is poisonous.     30 metals are welded by using the heat produced by burning a gas in oxygen.        which gas could not be used for this purpose?  a ethene  b hydrogen  c helium  d methane     31 which elements are present in npk fertilisers?  a nitrogen, phosphorus, potassium  b nitrogen, potassium, calcium  c sodium, phosphorus, potassium  d sodium, potassium, calcium    ",
            "12": "12  \u00a9 ucles 2015 0620/12/o/n/15  32 the apparatus shown is set up and left for a week.    damp iron wool air water     which diagram shows the level of the water at the end of the week?    a b c d       33 a farmer moves his cows into a concrete shelter for protection.   there is little access for fresh air once the door is closed.    which gases would increase in amount in the shelter?  a carbon dioxide and carbon monoxide  b carbon dioxide and methane  c carbon monoxide and oxygen  d methane and oxygen     ",
            "13": "13  \u00a9 ucles 2015 0620/12/o/n/15 [turn over  34 a student is asked to draw a diagram showing the uses of limestone.    limestone making  cement making lime added, with hematite,  to a blast furnace 1 2  3      which numbered lines show a correct use of limestone?  a 1, 2 and 3  b 1 and 2 only  c 1 and 3 only  d 2 and 3 only     35 which formula is that of an alkene?  a c 2h6 b c 3h6 c c 3h8 d c 4h10    36 which row describes the formation of a polymer?     monomer polymer  a ethane poly(ethane)  b ethane poly(ethene)  c ethene poly(ethane)  d ethene poly(ethene)    37 hydrocarbons obtained by fractional distillation of petroleum can be cracked to make useful  products.    which substance could not be obtained by cracking propane, m r 44?  a c2h4 b c3h6 c c4h8 d h2    ",
            "14": "14  \u00a9 ucles 2015 0620/12/o/n/15  38 ethanol can be formed by    1 fermentation  2 reaction between steam and ethene    which of these processes uses a catalyst?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      39 the flow chart shows the preparation of ethanol and some important chemistry of ethanol.    ethanol carbon dioxide + substance z substance xprocess y fermentation     what are x, y and z?     x y z  a ethane combustion yeast  b glucose combustion steam  c water polymerisation water  d yeast fermentation glucose     40 what are the properties of a dilute solution of ethanoic acid?     smell appearance  a odourless colourless  b odourless red  c pungent smell colourless  d pungent smell red    ",
            "15": "15  \u00a9 ucles 2015 0620/12/o/n/15  blank page",
            "16": "16    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    \u00a9 ucles 2015 0620/12/o/n/15   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements  "
        },
        "0620_w15_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 16 printed pages.  ib15 11_0620_13/4rp  \u00a9 ucles 2015 [turn over       *0977517416* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice  october/november 2015       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2015 0620/13/o/n/15  1 in which process do particles move closer together but remain in motion?  a condensation  b diffusion  c evaporation  d freezing      2 a student was asked to measure the rate of reaction between dilute hydrochloric acid and marble  chips at different temperatures.    some of the apparatus used is shown.        which two other pieces of apparatus would be needed?  a balance and pipette  b balance and stopclock  c beaker and stopclock  d burette and pipette     3 argon, ar, has a higher relative atomic mass than potassium, k, but appears before it in the  periodic table.    kar     why is argon listed before potassium in the periodic table?  a argon has fewer neutrons than potassium.  b argon has fewer protons than potassium.  c argon has more neutrons than potassium.  d argon has more protons than potassium. ",
            "3": "3  \u00a9 ucles 2015 0620/13/o/n/15 [turn over  4 in the following diagrams, x and y are atoms of different elements.   which diagram correctly shows the arrangement of outer electrons in a molecule of methane?    xyy ya xy yb xy yyyc xy yyyd       5 what do the nuclei of h1 1 hydrogen atoms contain?  a electrons and neutrons  b electrons and protons  c neutrons only  d protons only      6 the electronic structures of atoms x and y are shown.    x y     x and y form a covalent compound.    what is its formula?  a xy 5 b xy 3 c xy d x 3y     7 copper( ii) oxide reacts with ammonia.   the left hand side of the balanced equation for this reaction is:  3cuo  +  2nh 3 \u2192   what completes the equation?  a 3cu  +  2hno 3  b 3cu  +  2n  +  3h 2o  c 3cu  +  n 2  + 3h 2o  d 3cu  +  2no  +  3h 2o     ",
            "4": "4  \u00a9 ucles 2015 0620/13/o/n/15  8 what are the electrode products when molten silver iodide is electrolysed between inert  electrodes?   cathode anode  a hydrogen iodine  b iodine silver  c silver iodine  d silver oxygen      9 the diagram shows a section of an overhead power cable.    aluminiumsteel ceramic     which statement explains why a particular substance is used?  a aluminium has a low density and is a good conductor of electricity.  b ceramic is a good conductor of electricity.  c steel can rust in damp air.  d steel is more dense than aluminium.      10 which reaction is endothermic?  a the burning of magnesium ribbon  b the combustion of methane  c the decomposition of calcium carbonate  d the reaction of water with anhydrous copper( ii) sulfate     ",
            "5": "5  \u00a9 ucles 2015 0620/13/o/n/15 [turn over  11 a metal reacts with an aqueous solution.    the graph shows the temperature before, during and after the reaction.    time temperature      which row describes the reaction?     reaction energy change  a combustion endothermic  b combustion exothermic  c thermal decomposition endothermic  d thermal decomposition exothermic      12 which of the following changes decreases the rate of the reaction between magnesium and dilute  hydrochloric acid?  1 diluting the acid  2 using larger pieces of magnesium  3 cooling the mixture  a 1, 2 and 3  b 1 and 2 only  c 1 and 3 only  d 2 and 3 only      13 the element vanadium, v, forms several oxides.    in which change is oxidation taking place?  a vo 2 \u2192 v 2o3  b v2o5 \u2192 vo 2  c v2o3 \u2192 vo  d v2o3 \u2192 v 2o5     ",
            "6": "6  \u00a9 ucles 2015 0620/13/o/n/15  14 if anhydrous copper( ii) sulfate is added to water, which colour change is observed?  a blue to pink  b blue to white  c pink to blue  d white to blue     15 element x is in group i of the periodic table.    which row shows the type of oxide and whether element x is metallic or non-metallic?   type of oxide metallic or  non-metallic  a acidic metallic  b acidic non-metallic  c basic metallic  d basic non-metallic    16 three liquids, p, q and r, are added to a mixture of hydrochloric acid and universal indicator  solution.    the following observations are made.    p the colour of the indicator turns purple.  q the colour of the indicator does not change.  r there is effervescence and the indicator turns blue.  what are p, q and r?     p q r  a sodium carbonate  solution water sodium hydroxide  solution  b sodium hydroxide  solution water sodium carbonate  solution  c water sodium carbonate  solution sodium hydroxide  solution  d water sodium hydroxide  solution sodium carbonate  solution     ",
            "7": "7  \u00a9 ucles 2015 0620/13/o/n/15 [turn over  17 which property is not characteristic of a base?  a it reacts with a carbonate to form carbon dioxide.  b it reacts with an acid to form a salt.  c it reacts with an ammonium salt to form ammonia.  d it turns universal indicator paper blue.      18 zinc sulfate is a soluble salt and can be prepared by reacting excess zinc carbonate with dilute  sulfuric acid.    which piece of equipment would not be required in the preparation of zinc sulfate crystals?  a beaker  b condenser  c evaporating dish  d filter funnel      19 an element, x, is a dark grey crystalline solid at room temperature.    it has a melting point of 114  \u00b0c and a density of 4.9  g / cm3.    when heated gently it forms a purple vapour.    where in the periodic table is x found?    a b c d     ",
            "8": "8  \u00a9 ucles 2015 0620/13/o/n/15  20 j and k are two elements from the same period in the periodic table.    the table gives some properties of j and k.     j k  appearance shiny grey dull yellow  electrical conductivity when solid good poor  malleability malleable brittle    which statement about j and k is correct?  a j forms an acidic oxide.  b j is found to the left of k in the periodic table.  c k forms positive ions when it reacts.  d k is more metallic than j.     21 the table gives information about four elements.    which element is a transition metal?     electrical  conductivity density in  g  / cm3 melting point  in \u00b0c  a good 0.97 98  b good 7.86 1535  c poor 2.33 1410  d poor 3.12 \u20137    22 hydrogen and helium have both been used to fill balloons.    which property of helium makes it the preferred choice to hydrogen?  a easily compressed into a gas cylinder  b forms monatomic molecules  c lower density  d unreactive     ",
            "9": "9  \u00a9 ucles 2015 0620/13/o/n/15 [turn over  23 which statement is true for all metals?  a their atoms lose one or more electrons when they react.  b they are brittle.  c they do not conduct electricity when solid.  d they melt at low temperatures when they are heated.      24 the diagrams show what happens when three different metals are added to water.    x y zbubbles of gasflame     what are x, y and z?     x y z  a calcium copper potassium  b copper calcium potassium  c potassium calcium copper  d potassium copper calcium     25 the table show three uses of aluminium and a reason why aluminium is used for that purpose.   use reason  1 aircraft manufacture high tensile strength  2 overhead electricity cables low density  3 food containers resistance to corrosion    which reasons explain the use?  a 1, 2 and 3  b 1 and 2 only  c 1 and 3 only  d 2 and 3 only    ",
            "10": "10  \u00a9 ucles 2015 0620/13/o/n/15  26 which conditions are necessary to make mild steel from iron?  a add calcium oxide and blow oxygen through it  b heat with calcium oxide  c heat with carbon and limestone  d heat with nickel and chromium      27 which statements about water are correct?    1 household water may contain salts in solution.  2 water for household use is filtered to remove soluble impurities.  3 water is treated with chlorine to kill bacteria.  4 water is used in industry for cooling.    a 1, 2, 3 and 4   b 1, 2 and 3 only  c 1, 3 and 4 only  d 2, 3 and 4 only      28 the diagram shows the flame produced from burning a hydrocarbon, acetylene, in a welding  torch.    x acetylene     which gas is x?  a hydrogen  b methane  c nitrogen  d oxygen     ",
            "11": "11  \u00a9 ucles 2015 0620/13/o/n/15 [turn over  29 carbon monoxide is an air pollutant produced when petrol is burned in a car engine.    why is carbon monoxide considered to be an air pollutant?  a it causes climate change.  b it causes the corrosion of buildings.  c it is a significant greenhouse gas.  d it is poisonous.     30 which compound is not a fertiliser?  a ammonium sulfate, (nh 4)2so 4  b calcium hydroxide, ca(oh) 2  c potassium chloride, kc l  d urea, co(nh 2)2     31 in which reaction is carbon dioxide not produced?  a complete combustion of petrol  b hydrochloric acid reacting with magnesium  c respiration  d thermal decomposition of limestone     ",
            "12": "12  \u00a9 ucles 2015 0620/13/o/n/15  32 the apparatus shown is set up and left for a week.    damp iron wool air water     which diagram shows the level of the water at the end of the week?    a b c d       33 unwanted vegetation is sometimes placed in a bin where it decays to form compost. this  compost can be used to fertilise soils.    which gas is likely to be present in a higher percentage inside the bin than in the air outside the bin?  a carbon monoxide  b methane  c oxygen  d sulfur dioxide     ",
            "13": "13  \u00a9 ucles 2015 0620/13/o/n/15 [turn over  34 a student is asked to draw a diagram showing the uses of limestone.    limestone making  cement making lime added, with hematite,  to a blast furnace 1 2  3      which numbered lines show a correct use of limestone?  a 1, 2 and 3  b 1 and 2 only  c 1 and 3 only  d 2 and 3 only     35 what are the names of the compounds shown in the reaction scheme below?    h ch hhhhh butanehh c c c hh ch hhh wxcchhhh c h h ch hh oh yc h h ch ho zc oh+cracking oxygensteam      w x y z  a ethane ethene ethanol ethanoic acid  b ethane ethene ethanoic acid ethanol  c ethene ethane ethanol ethanoic acid  d ethene ethane ethanoic acid ethanol     ",
            "14": "14  \u00a9 ucles 2015 0620/13/o/n/15  36 which row describes the formation of a polymer?     monomer polymer  a ethane poly(ethane)  b ethane poly(ethene)  c ethene poly(ethane)  d ethene poly(ethene)     37 which row shows the correct use of a fraction obtained by the fractional distillation of petroleum?   fraction use  a bitumen making waxes and polishes  b fuel oil aircraft fuel  c kerosene fuel for ships  d naphtha making chemicals    38 ethanol can be formed by    1 fermentation  2 reaction between steam and ethene    which of these processes uses a catalyst?     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "15": "15  \u00a9 ucles 2015 0620/13/o/n/15  39 the structures of four compounds are shown.    h ch hhw hhh c c hchhx hhh c c h h ch hhy hhh c c chh hhh h c chh hz       which are members of the same homologous series?  a w, x, y and z  b w and x only  c w, y and z only  d x and z only     40 during the process of cracking hydrocarbons, an ... 1 ... is converted into an ... 2 ... .    the presence of an ... 3 ... can be shown by a visible reaction with ... 4 ... .    which words complete gaps 1, 2, 3 and 4?     1 2 3 4  a alkane alkene alkene bromine  b alkane alkene alkene steam  c alkene alkane alkane bromine  d alkene alkane alkane steam    ",
            "16": "16    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    \u00a9 ucles 2015 0620/13/o/n/15   group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 2 4dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic t able of the elements    "
        },
        "0620_w15_qp_21.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/21   paper 2 october/november 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages . [turn overib15 11_0620_21/3rp\u00a9 ucles 2015 *9575812330* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/21/o/n/15 \u00a9 ucles 20151  the structures of six compounds are shown below. alcl clclcl alclcl cla c c hh h h so42\u2013b d f eo h h ba2+nh4+nh4+ nh4+nh4+ so42\u2013 nh4+nh4+so42\u2013nh4+ nh4+ so42\u2013 nh4+so42\u2013nh4+ nh4+ so42\u2013 nh4+hcl \u2013 cl \u2013cl \u2013 cl \u2013 ba2+ cl \u2013cl \u2013ba2+cl \u2013 cl \u2013 ba2+ cl \u2013ba2+cl \u2013 cl \u2013 ba2+ cl \u2013   answer the following questions about these substances.   each compound may be used once, more than once or not at all.  (a)  which substance, a, b, c, d, e or f,  (i)  gives a white precipitate on addition of an aqueous solution of   sodium sulfate, ..  [1]  (ii)  is a component of many fertilisers, ..  [1]  (iii)  contains a group iii element, ..  [1]  (iv)  is an acidic gas at room temperature, ..  [1]  (v)  turns anhydrous cobalt chloride pink, ..  [1]  (vi)  is the main component of natural gas? ..  [1]",
            "3": "3 0620/21/o/n/15 \u00a9 ucles 2015 [turn over (b)  compound a can be made by direct combination of chlorine and aluminium using the apparatus  shown below. chlorine excess chlorinealuminium foilcompound a al 2cl 6  (i)  on the diagram above, draw an arrow to show where heat is applied. [1]  (ii)  suggest one safety precaution that should be taken when carrying out this experiment.   ...   [1]  (iii)  complete the symbol equation for this reaction. 2al  +  c l 2  \u2192  al 2cl 6 [1] [total: 9]",
            "4": "4 0620/21/o/n/15 \u00a9 ucles 20152  a student measures the maximum temperature changes when five different solids, p, q, r, s and t,  are dissolved separately in water. she uses the apparatus shown below. solid thermometer stirrer  (a)  the student stirs the mixture as each solid is added.   suggest why she does this.      ..   [1]  (b)  suggest two factors which should be kept the same to make the experiment a fair test.  1.    2.  ..   [2]  (c)  the table of results is shown below. solid addedinitial temperature of the water / \u00b0chighest temperature of the solution / \u00b0c p 20 24 q 18 23 r 19 16 s 22 23 t 20 18  (i)  which solid gave the greatest temperature change when dissolved in water?   ...   [1]  (ii)  which solids gave an endothermic energy change when dissolved in water?  ... and     [2]",
            "5": "5 0620/21/o/n/15 \u00a9 ucles 2015 [turn over (d)  radioactive isotopes can be used as a source of energy.  (i)  which one of the following isotopes is a radioactive isotope?   put a ring around the correct answer. c12 6               u235 92               h1 1               zn65 30 [1]  (ii)  an isotope of radium, ra, has 226 nucleons in its nucleus.   how many neutrons does this isotope contain?   use your periodic table.   ...   [1]  (iii)  give one use of radioactive isotopes in medicine.   ...   [1]  (e)  fractions obtained from the distillation of petroleum are also sources of energy.  (i)  which one of the following fractions is used as a fuel for jet aircraft?   put a ring around the correct answer. bitumen         gasoline         kerosene         naphtha [1]  (ii)  heptadecane, c17h36, is present in the fuel oil fraction.   complete the equation for the cracking of heptadecane to form two hydrocarbons. c17h36  \u2192  c12h26  +   [1] [total: 11]",
            "6": "6 0620/21/o/n/15 \u00a9 ucles 20153 (a)  nickel is extracted from nickel( ii) oxide, nio, by heating with carbon.   complete the symbol equation for this reaction. .nio  +  c  \u2192  2ni  +  ... [2]  (b)  nickel is refined by electrolysis.  (i)  complete the boxes to label the diagram below to show  \u2022  the negative electrode (cathode),  \u2022  the positive electrode (anode),  \u2022  the electrolyte. + \u2013 [2]  (ii)  at which electrode is the pure nickel formed?   ...   [1]  (c)  molten nickel( ii) chloride can be electrolysed using graphite electrodes.  (i)  predict the products of this electrolysis at  the positive electrode (anode),  ...  the negative electrode (cathode).  ... [2]  (ii)  give two reasons why graphite is used for electrodes.  1.  .  2.  . [2]",
            "7": "7 0620/21/o/n/15 \u00a9 ucles 2015 [turn over (d)  the structures of diamond and graphite are shown below. diamond graphite  (i)  explain how the structure of diamond relates to its use in cutting hard materials.   .   .   ...   [2]  (ii)  explain how the structure of graphite relates to its use as a lubricant.   .   .   ...   [2] [total: 13]",
            "8": "8 0620/21/o/n/15 \u00a9 ucles 20154  a teacher demonstrated the reactivity of calcium with water. he used the apparatus shown below. water calciumgas syringe  (a)  the teacher measured the volume of gas given off at various times during the reaction. he  then repeated the experiment using strontium but keeping all the conditions the same.   the graph obtained from the results is shown below. 60 50 40 30 20 10 0 0 20 40 time  / s60 80 100volume of gas  / cm3calciu mstrontium  (i)  explain how the graph shows that strontium is more reactive than calcium.   .   ...   [1]  (ii)  for the reaction between calcium and water, deduce the volume of gas produced in the  first 50 seconds. . cm3  [1]",
            "9": "9 0620/21/o/n/15 \u00a9 ucles 2015 [turn over (iii)  at what time was the reaction between strontium and water complete? . s  [1]  (iv)  how do you know from the graph that the reaction between calcium and water was not  complete 100 seconds after the reaction started?   ...   [1]  (v)  suggest how the rate of reaction changes when the same mass of calcium is used but in  smaller pieces.   ...   [1]  (b)  the solution formed at the end of the reaction between strontium and water is alkaline. it is a solution of strontium hydroxide.   the teacher titrated this solution with hydrochloric acid using the apparatus shown below. hydrochloric acid 25 cm3 strontium hydroxide solutionburette  (i)  what piece of apparatus should be used to put exactly 25.0 cm3 of the strontium hydroxide  solution into the flask?   ...   [1]  (ii)  a few drops of litmus solution was added to the flask.   explain why litmus is added to the flask and describe what happens to the litmus as the  titration proceeds.   .   .   ...   [2]",
            "10": "10 0620/21/o/n/15 \u00a9 ucles 2015 (c)  the graph below shows how the ph of the solution in the flask changes as the acid is added. 12 10 8 6 4 2 0 0 10 20 volume of hydrochloric acid  / cm330 40 50ph  (i)  describe how the ph of the solution changes as the titration proceeds.   .   .   ...   [3]  (ii)  what volume of acid had been added when the solution had a neutral ph?   ...   [1]  (iii)  the symbol equation for the reaction is sr(oh)2  +  2hcl  \u2192  srcl 2  +  2h2o   give the name of the salt formed in this reaction.   ...   [1] [total: 13]",
            "11": "11 0620/21/o/n/15 \u00a9 ucles 2015 [turn over5  a student left a cube of ice on a plate in a warm room. the diagrams below show what happened  to the ice. at the start after 10 minutes after 30 minutes  (a)  describe and explain what happened to the ice. in your answer,  \u2022  describe and explain the change of state which occurs,  \u2022  explain this change using the kinetic particle theory.                  ..   [5]  (b)  water is used in industry and in the home.  (i)  give one use of water in industry.   ...   [1]  (ii)  give one use of water in the home.   ...   [1]  (c)  the symbol equation for the reaction of lithium with water is shown below. 2li(s)  +  2h2o(l)  \u2192  2lioh(aq)  +  h2(g)  (i)  write the word equation for this reaction.   ...   [1]  (ii)  describe two observations which can be made when lithium reacts with water.   .   ...   [2]  (iii)  describe how the reactivity of potassium with water compares with the reactivity of lithium with water.   ...   [1]",
            "12": "12 0620/21/o/n/15 \u00a9 ucles 2015 (d)  ethanol can be made by the reaction of steam with ethene.  (i)  draw the structure of ethene showing all atoms and all bonds. [1]  (ii)  describe the conditions required for this reaction.   ...   [2]  (e)  the table below describes the reaction of water or steam with different metals. metal observations calcium reacts rapidly with cold water cerium reacts slowly with hot water and very rapidly with steam cobalt reacts with steam when cobalt powder is very hot iron reacts very slowly with hot water and readily with steam   put these metals in order of their reactivity. least reactive most reactive [2] [total: 16]",
            "13": "13 0620/21/o/n/15 \u00a9 ucles 2015 [turn over6  when rubber is distilled, a chemical called isoprene is formed.   the structure of isoprene is shown below. c cch hh hhh hh cc  (a)  deduce the molecular formula of isoprene.   ..   [1]  (b)  isoprene is an unsaturated compound.   describe a test for an unsaturated compound.  test  .  result     [2]  (c)  isoprene forms an addition polymer.  (i)  what feature of the isoprene molecule is responsible for it forming an addition polymer?   ...   [1]  (ii)  give the name of another addition polymer.   ...   [1]  (d) isoprene does not conduct electricity.   explain why.   ..   [1]  (e)  state the names of two substances formed when isoprene undergoes incomplete combustion.  ... and  ...   [2]",
            "14": "14 0620/21/o/n/15 \u00a9 ucles 2015 (f)  isoprene can be prepared from 3-methylbutan-1-ol.   to which group of compounds does 3-methylbutan-1-ol belong?   tick one box.  alcohols  alkanes  alkenes  carboxylic acids [1] [total: 9]",
            "15": "15 0620/21/o/n/15 \u00a9 ucles 2015 [turn over7 (a)  sodium is in group i of the periodic table.   describe the structure of a sodium atom.  in your answer refer to,  \u2022  the type and number of each subatomic particle present,  \u2022  the charges on each type of subatomic particle,  \u2022  the position of each type of subatomic particle in the atom.                     ..   [5]  (b)  sodium carbide, na2c2, reacts with water to form ethyne, c2h2.  (i)  complete the symbol equation for this reaction. na2c2  +  ...h2o  \u2192  ...naoh  +  c2h2 [2]  (ii)  ethyne is a hydrocarbon.   what is the meaning of the term hydrocarbon?   ...   [1]  (iii)  calculate the relative formula mass of sodium carbide. [1] [total: 9]",
            "16": "16 0620/21/o/n/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. group 140 ce ceriu m 58141 pr praseodymium 59144 nd neodymium 60pm promethiu m 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactiniu m 91238 u uraniu m 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californiu m 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithiu m 3 23 na sodium 1124 mg magnesiu m 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromiu m 2455 mn manganes e 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga galliu m 3127 al aluminium 1311 b boron 512 c carbo n 614 n nitroge n 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphoru s 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmiu m 48115 in indium 49119 sn tin 50122 sb antimony 51128 te telluriu m 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanu m 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rheniu m 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4i ii iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numbe rkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the element s"
        },
        "0620_w15_qp_22.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/22   paper 2 october/november 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 14 printed pages and 2 bla nk pages. [turn overib15 11_0620_22/2rp\u00a9 ucles 2015 *7994315301* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/22/o/n/15 \u00a9 ucles 20151  the structures of six substances are shown below. agagagag agagagagagagaga fefefe fe fefe ninini fefefe xe xexe xexeb na+i\u2013na+ i\u2013na+i\u2013na+i\u2013 na+i\u2013na+i\u2013c def n oon oo n ooff f ff fff   answer the following questions about these substances.   each substance may be used once, more than once or not at all.  (a)  which substance, a, b, c, d, e or f,  (i)  is a simple molecular compound, ..  [1]  (ii)  is an alloy, ..  [1]  (iii)  is a compound, whose aqueous solution gives a yellow   precipitate on addition of aqueous silver nitrate, ..  [1]  (iv)  is an atmospheric pollutant arising from reactions taking  place in car engines, ..  [1]  (v)  is a diatomic molecule, ..  [1]  (vi)  conducts electricity when molten but not when solid? ..  [1]  (b)  substance a is an element.   what is meant by the term element ?   ... .   ... ...  [1]  (c)  substance d oxidises water to oxygen.   complete the symbol equation for this reaction. 2f2  +  2h2o  \u2192  ...hf  +  ... [2] [total: 9]",
            "3": "3 0620/22/o/n/15 \u00a9 ucles 2015 [turn over2  a student measured the highest temperature reached when four different fuels were burned. he  used the apparatus shown below. thermomete r copper can fuelclamp water spirit burner  (a)  the same amount of each fuel was burned.   suggest two other things which the student should keep constant to make the experiment a  fair test.  1.  ... .  2.  ... . [2]  (b)  is burning an exothermic or an endothermic reaction?   give a reason for your answer.   ... ...  [1]  (c)  the table below shows the results. fuelmolecular formulainitial temperature / \u00b0c\ufb01 nal temperature / \u00b0c ethanol c2h6o2 3 4 4 hexane c6h14 17 46 pentane c5h12 22 48 propanol c3h8o2 1 4 5  (i)  which fuel gave the highest temperature change?   . ..  [1]  (ii)  which fuel has the highest relative molecular mass?   you are not expected to do any calculations.   . ..  [1]",
            "4": "4 0620/22/o/n/15 \u00a9 ucles 2015 (d)  methane is a fuel.  (i)  draw the structure of methane showing all atoms and all bonds. [1]  (ii)  which one of the following fuels is largely methane?   tick one box.  coal fuel oil gasoline natural gas [1]  (e)  pentane and hexane belong to the same homologous series.  (i)  how can you tell this from their names?   . ..  [1]  (ii)  complete the following sentence about a homologous series using words from the list  below.  acidic alcohol compounds density different  elements functional masses properties solid  a homologous series is a family of similar ... with similar ...    due to the presence of the same ... group. [3] [total: 11]",
            "5": "5 0620/22/o/n/15 \u00a9 ucles 2015 [turn over3  the order of reactivity of zinc, magnesium, calcium and barium is shown below. zinc  \u2192  magnesium  \u2192  calcium  \u2192  barium least reactive    most reactive  (a)  equal-sized pieces of zinc, magnesium, calcium and barium are placed in water.   some observations from these reactions are shown in the table.  (i)  complete the box for barium. metal observations zinc no reaction with cold watermagnesium gives a few bubbles with hot water, does not disappearcalcium gives off bubbles steadily with cold water, gets smaller slowlybarium [2]  (ii)  give the name of a metal in the above table which is extracted by heating with carbon.   . ..  [1]  (iii)  suggest why barium cannot be extracted using carbon.   . ..  [1]  (b)  barium can be extracted by heating barium oxide with aluminium. 4bao  +  2a l  \u2192  3ba  +  baa l  2o4   how does this equation show that barium oxide gets reduced?   ... ...  [1]  (c)  a solution of barium hydroxide is alkaline.  (i)  describe how you would show that barium hydroxide solution is alkaline.   . ..  [1]  (ii)  complete the word equation for the reaction of barium hydroxide with hydrochloric acid. barium hydroxide+hydrochloric acid\u2192. .+ . [2]",
            "6": "6 0620/22/o/n/15 \u00a9 ucles 2015 (d)  a student used the apparatus shown below to calculate the concentration of barium hydroxide  solution. hydrochloric acid barium hydroxide solutiona  (i)  give the name of the piece of apparatus labelled a.   . ..  [1]  (ii)  the hydrochloric acid is added to the barium hydroxide solution in the \ufb02 ask until the acid  is in excess.   describe how the ph of the solution changes as the acid is added.   .    . ..  [2]  (e)  complete the diagram below for the electrolysis of molten zinc chloride.   label the electrodes and the power source. molten zinc chloride [3] [total: 14]",
            "7": "7 0620/22/o/n/15 \u00a9 ucles 2015 [turn over4  a student investigated the reaction of lumps of iron with sulfuric acid. fe(s)  +  h2so4(aq)  \u2192  feso4(aq)  +  h2(g)   she used the apparatus shown below. sulfuric acid lumps of ironwate r  (a) (i)   describe how this apparatus can be used to investigate the rate of this reaction.   .    .    . ..  [3]  (ii)  describe how the rate of reaction would differ if smaller lumps of iron were used.   all other conditions remain the same.   . ..  [1]  (b)  the student investigated the effect of temperature on the reaction rate.  (i)  state three  factors which the student should keep the same in each experiment.  1.  .. ...  2.  .. ...  3.  .. ... [3]",
            "8": "8 0620/22/o/n/15 \u00a9 ucles 2015 (ii)  the table shows how the rate of reaction changed with temperature. temperature / \u00b0crate of reaction in cm3 / s 20 2.2 30 4.440 8.850 17.6   use the information in the table to describe how the rate of reaction changed with  temperature.   .    . ..  [2]  (c)  iron( ii) sulfate can be prepared by adding excess iron to sulfuric acid.   describe how you could obtain pure dry crystals of iron( ii) sulfate from the reaction mixture in  the conical \ufb02 ask.   ... .   ... .   ... .   ... ...  [3] [total: 12]",
            "9": "9 0620/22/o/n/15 \u00a9 ucles 2015 [turn over5  a crystal of sulfur melts when heated.  (a)  explain, using the kinetic particle theory, the differences between the arrangement and motion  of the particles in sulfur crystals and liquid sulfur.   ... .   ... .   ... .   ... .   ... ...  [4]  (b)  sulfur dioxide is an atmospheric pollutant.  (i)  describe how sulfur dioxide is formed and how it gets into the atmosphere.   .    .    . ..  [2]  (ii)  what type of oxide is sulfur dioxide?   . ..  [1]  (iii)  flue gas desulfurisation removes sulfur dioxide from exhaust gases in factories.   describe the process of \ufb02 ue gas desulfurisation.   .    . ..  [2]  (iv)  sulfur dioxide is also formed when copper is reduced by hot concentrated sulfuric acid.   complete the symbol equation for this reaction. cu  +  ..h2so4  \u2192  cuso4  +  so2  +  ..h2o [2]  (c)  copper is a metal.   give two physical properties which are characteristic of all metals.  1.  ... .  2.  ... . [2]",
            "10": "10 0620/22/o/n/15 \u00a9 ucles 2015 (d)   the table below gives some properties of some metals that are used to make electrical cables  and wires. metal strengthelectrical conductivitymelting point / \u00b0cprice $ / kg aluminium comparatively weak good 660 1.5 copper strong very good 1093 29 steel strong fairly good 1535 2.1 silver fairly strong very good 962 635  (i)  suggest why aluminium with a steel core is used for overhead power cables.   .    . ..  [2]  (ii)  copper is used in electrical wiring in the home rather than silver.   suggest why.   . ..  [1] [total: 16]",
            "11": "11 0620/22/o/n/15 \u00a9 ucles 2015 [turn over6  geraniol is a chemical found in rose petals.   the structure of geraniol is shown below. cch ch3ch3 ch3ch2ch2 c hch2oh c  (a) (i)   on the structure above, put a ring around the alcohol functional group. [1]  (ii)  is geraniol a saturated or an unsaturated compound?   give a reason for your answer.   . ..  [1]  (b)  geraniol can be extracted from rose petals by steam distillation using the apparatus shown  below. the geraniol is carried off in small droplets with the steam. a geraniol water heatx rose petals and water  (i)  give the name of the piece of apparatus labelled a.   . ..  [1]  (ii)  the vapour at point x is a mixture of geraniol and steam.   give one property of a mixture which distinguishes it from a compound.   .    . ..  [1]  (iii)  the geraniol and water are collected in the beaker.   what information in the diagram above shows that geraniol is less dense than water?   . ..  [1]",
            "12": "12 0620/22/o/n/15 \u00a9 ucles 2015 (c)  geraniol can also be extracted from rose petals by grinding the petals in ethanol.  (i)  draw the structure of ethanol showing all atoms and all bonds. [1]  (ii)  complete the word equation for the complete combustion of ethanol. ethanol  +  oxygen  \u2192  ..  +   [2]  (d)  what is the percentage by volume of oxygen in the air?   ... ...  [1] [total: 9]",
            "13": "13 0620/22/o/n/15 \u00a9 ucles 2015 [turn over7  beryllium is in group ii and period 2 of the periodic table.  (a)  describe the structure of a beryllium atom.   in your answer, refer to  \u2022  the type and number of each subatomic particle present,  \u2022  the charges on each type of subatomic particle,  \u2022  the position of each type of subatomic particle in the atom.   ... .   ... .   ... .   ... .   ... .   ... .   ... ...  [5]  (b)  part of the structure of beryllium chloride is shown below. cl clcl be clcl becl be   deduce the simplest formula for beryllium chloride.   ... ...  [1]  (c)  beryllium carbide, be2c, reacts with water. beryllium hydroxide and methane are formed. be2c  +   4h2o  \u2192  2be(oh)2  +  ch4  (i)  calculate the relative formula mass of beryllium hydroxide. [2]  (ii)  describe one adverse effect of methane on the environment.   . ..  [1] [total: 9]",
            "14": "14 0620/22/o/n/15 \u00a9 ucles 2015blank page",
            "15": "15 0620/22/o/n/15 \u00a9 ucles 2015blank page",
            "16": "16 0620/22/o/n/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w15_qp_23.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name in the spaces at the top of this page. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on pa ge 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/23   paper 2 october/november 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib15 11_0620_23/3rp\u00a9 ucles 2015 *7225024004* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/23/o/n/15 \u00a9 ucles 20151  the structures of six gases are shown below. a ar o o o c o n n c hh hh cb c d e f cl cl   answer the following questions about these gases.   each gas may be used once, more than once or not at all.  (a)  which gas, a, b, c, d, e or f  (i)  bleaches damp litmus paper, ..  [1]  (ii)  forms 79% of the air, ..  [1]  (iii)  is a noble gas, ..  [1]  (iv)  can undergo polymerisation, ..  [1]  (v)  decolourises aqueous bromine, ..  [1]  (vi)  is a product of respiration? ..  [1]  (b)  gas f is a compound.   define the term compound .      ..   [1]  (c)  give a use for gas e.   ..   [1]  (d)  when magnesium is heated in gas c magnesium nitride, mg3n2, is formed.   complete the symbol equation for this reaction. ..mg  +  ..  \u2192  mg3n2 [1] [total: 9]",
            "3": "3 0620/23/o/n/15 \u00a9 ucles 2015 [turn over2  household waste can be burned to produce energy.   the table shows the energy released by different materials when the waste is burned. material burnedmass burned / kgenergy released / kj metals 1.0 1 000 organic matter 0.5 8 000 paper 2.0 40 000 plastics 1.0 30 000 cloth 1.0 15 000  (a)  which material releases the most energy per kilogram when burned?   ..   [1]  (b)  which one of the following words best describes the energy change when a substance is  burned?   tick one box.  endothermic  neutralisation  exothermic  reduction [1]  (c)  the structure of part of a plastic is shown below. ch2 ch2ch3 ch chcn oo c   how many different types of atom are present in this plastic?   ..   [1]",
            "4": "4 0620/23/o/n/15 \u00a9 ucles 2015 (d)  waste paper can be converted into an \u2018oil\u2019 by heating it at 350 \u00b0c under pressure in the presence  of a catalyst.  (i)  what is the purpose of the catalyst?   ...   [1]  (ii)  the \u2018oil\u2019 has the formula, c22h22o2.   complete the word equation for the complete combustion of this oil. \u2018oil\u2019  +  oxygen  \u2192  ..  +  . [2]  (e)  some plastics contain sulfur.   explain why plastics containing sulfur are harmful to the environment when burned.      ..   [2]  (f)  when organic matter decomposes, methane and carboxylic acids are formed.  (i)  to which homologous series does methane belong?   ...   [1]  (ii)  ethanoic acid is a carboxylic acid.   state one physical property of ethanoic acid.   ...   [1]  (iii)  complete the formula for ethanoic acid showing all atoms and all bonds. chh h [1] [total: 11]",
            "5": "5 0620/23/o/n/15 \u00a9 ucles 2015 [turn over3  hydrogen chloride can be prepared in the laboratory by heating sodium chloride with concentrated  sulfuric acid using the apparatus shown below. sodium chlorideconcentrated sulfuric acid  (a)  complete the diagram by adding the labels in the boxes. [2]  (b)  the equation for the reaction is shown below. 2nac l  +  h2so4  \u2192  na2so4  +  2hcl   state the name of the salt formed as a product in this reaction.   ..   [1]",
            "6": "6 0620/23/o/n/15 \u00a9 ucles 2015 (c)  hydrogen chloride gas dissolves in water to form hydrochloric acid.  (i)  the diagram below shows the apparatus used to electrolyse concentrated hydrochloric  acid. x y + \u2013   label the diagram to show  \u2022 the anode,  \u2022 the cathode,  \u2022 the electrolyte. [2]  (ii)  give the names of the gases collected at  x,    y.  . [2]  (iii)  complete the word equation for the reaction of hydrochloric acid with calcium carbonate. hydrochloric acid+calcium carbonate\u2192. .+..+. [3]",
            "7": "7 0620/23/o/n/15 \u00a9 ucles 2015 [turn over (d)  aqueous ammonia is added slowly to a beaker containing hydrochloric acid.   the graph below shows how the ph of the solution in the flask changes as the aqueous  ammonia is added. 10 8 6 4 2 0ph 0 10 20 30 volume of aqueous ammonia  / cm340  (i)  what was the ph of the hydrochloric acid at the start of the experiment?   ...   [1]  (ii)  describe how the ph of the solution changes as the titration proceeds.   .   .   ...   [3] [total: 14]",
            "8": "8 0620/23/o/n/15 \u00a9 ucles 20154  ethanol can be made by fermenting glucose.  yeast glucose    ethanol  +  carbon dioxide   a student investigated the fermentation of glucose at 30 \u00b0c. she used the apparatus shown below. fermentation mixturewater  (a)  describe how this apparatus can be used to investigate the rate of this reaction.         ..   [3]",
            "9": "9 0620/23/o/n/15 \u00a9 ucles 2015 [turn over (b)  the graph below shows how the rate of fermentation changes with time. 0.4 0.3 0.20.10.0rate of reaction /  cm3 co2 per hour 0 20 40 60 time  / hours80 100  (i)  describe how the rate of fermentation changes with time.   .   ...   [2]  (ii)  what is the rate of reaction 40 hrs after the start of the experiment? . cm3 co2 per hour  [1]  (iii)  suggest two ways to increase the rate of this reaction.  1  ..  2  .. [2]  (c)  if air is introduced into the fermentation mixture, some of the ethanol is converted to ethanoic acid.   ethanoic acid has properties which are typical of most acids.   suggest how you could distinguish between ethanoic acid and ethanol.      ..   [2] [total: 10]",
            "10": "10 0620/23/o/n/15 \u00a9 ucles 20155 (a)  mercury is a liquid at room temperature. when heated, it changes to mercury vapour.   explain, using the kinetic particle theory, the differences in the arrangement and motion of the  particles in liquid mercury and mercury vapour.               ..   [4]  (b)  the table below compares the properties of some metals. metalmelting point / \u00b0cboiling point / \u00b0ccorrosion resistance aluminium 660 2467resistant to corrosion because of oxide layer copper 1083 2567 fairly resistant to corrosion iron 1535 2750 corrodes easily potassium 63 760 corrodes very easily   use the information in the table to answer the following questions.  (i)  what is the state of potassium at 100 \u00b0c?   explain your answer.   .   ...   [2]  (ii)  which two metals in the table are transition elements?   explain your answer.   .   ...   [2]  (iii)  why is aluminium used for food containers?   ...   [1]",
            "11": "11 0620/23/o/n/15 \u00a9 ucles 2015 [turn over (c)  iron undergoes a form of corrosion called rusting.  (i)  state the conditions needed for rusting?   and  ...   [2]  (ii)  explain why painting a clean iron object prevents it from rusting.   ...   [1]  (d)  iron reacts with hydrochloric acid. a salt with the formula fecl 2 is formed as well as a gas  which pops with a lighted splint.  (i)  complete the word equation for this reaction. iron  +  hydrochloric acid  \u2192  ..  +  . [2]  (ii)  describe a test for iron( ii) ions.  test  ..  result  ... [2]  (e)  stainless steel is an alloy of iron.   give one use of stainless steel.   ..   [1] [total: 17]",
            "12": "12 0620/23/o/n/15 \u00a9 ucles 20156  petroleum is a mixture of hydrocarbons. hydrocarbon fractions are separated in an oil refinery. the  diagram shows the chemical plant used. xnaphthagasolinerefinery ga sfractions diesel lubricating fraction petroleum bitumenhighlow temperature  (a)  name the process by which hydrocarbon fractions are separated and state the physical property which allows this process to be carried out.      ..   [2]  (b)  use the information in the diagram above to answer these questions.  (i)  which fraction contains hydrocarbons with the lowest relative molecular masses?   ...   [1]  (ii)  state the name of the fraction labelled x.   ...   [1]",
            "13": "13 0620/23/o/n/15 \u00a9 ucles 2015 [turn over (c)  in some oil refineries, naphtha is heated with steam at 800 \u00b0c.   a mixture of hydrocarbons is formed.   some of these hydrocarbons are shown below. ch hh hca hh ch ch hcd hh hhhch hcb hh ch ch hce hh chh chh hhhc ch h hcc h hh  (i)  which two of these hydrocarbons are unsaturated?   and  ...   [1]  (ii)  compound d can be cracked to make hydrogen.   complete the symbol equation for this reaction. c3h8  \u2192    +   [2]  (d)  bitumen is a mixture of hydrocarbons.   bitumen is heated with copper( ii) oxide. w heatbitumen + copper( ii) oxide  (i)  a pinkish-brown solid appears at the bottom of the test-tube. this solid conducts electricity.   suggest the name of this pinkish-brown solid.   ...   [1]  (ii)  water collects on the walls of the test-tube at w.   suggest why water collects at this point?   ...   [1] [total: 9]",
            "14": "14 0620/23/o/n/15 \u00a9 ucles 20157 (a)  chlorine is in group vii of the periodic table.   one isotope of a chlorine atom has a nucleon number of 35.   describe the structure of an atom of this isotope of chlorine.   in your answer refer to  \u2022  the type and number of each subatomic particle present,  \u2022  the charges on each type of subatomic particle,  \u2022  the position of each type of subatomic particle in the atom.                     ..   [5]  (b)  chlorine reacts with sodium to form sodium chloride.   sodium chloride contains na+ ions and c l \u2013 ions.   explain why sodium ions are positively charged and chloride ions are negatively charged.         ..   [2]  (c)  when chlorine reacts with aqueous potassium iodide, the solution turns brown.  (i)  suggest why the solution turns brown.   ...   [1]  (ii)  explain why aqueous potassium chloride does not react with iodine.   ...   [1]",
            "15": "15 0620/23/o/n/15 \u00a9 ucles 2015 [turn over (d)  the structure of a chlorofluorocarbon is shown below. cf f f fcl fc   deduce the molecular formula of this compound.   ..   [1] [total: 10]",
            "16": "16 0620/23/o/n/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. group 140 ce ceriu m 58141 pr praseodymium 59144 nd neodymium 60pm promethiu m 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactiniu m 91238 u uraniu m 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californiu m 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithiu m 3 23 na sodium 1124 mg magnesiu m 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromiu m 2455 mn manganes e 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga galliu m 3127 al aluminium 1311 b boron 512 c carbo n 614 n nitroge n 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphoru s 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmiu m 48115 in indium 49119 sn tin 50122 sb antimony 51128 te telluriu m 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanu m 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rheniu m 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4i ii iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numbe rkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the element s"
        },
        "0620_w15_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/31   paper 3 (extended) october/november 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 12 printed pages. [turn overib15 11_0620_31/3rp\u00a9 ucles 2015 *7761599169* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/31/o/n/15 \u00a9 ucles 20151 (a)  the symbols of six particles are shown below. na+      ca2+      kr      p      si      o2\u2013   select from the list of particles to answer the following questions. a particle may be selected  once, more than once or not at all.  (i)  which two ions have the same electronic structure?  ...   [1]  (ii)  which ion has the same electronic structure as an atom of argon?  .   [1]  (iii)  which atom can form an ion of the type x3\u2013?  ...   [1]  (iv)  which atom can form a hydride which has a formula of the type xh4?     [1]  (b) (i) how many protons, neutrons and electrons are there in one copper( ii) ion cu2964 2+?  number of protons .  number of neutrons  .  number of electrons  . [2]  (ii)  sc2145 represents an atom of scandium.    how many nucleons and how many charged particles are there in one atom of scandium?  number of nucleons .  number of charged particles . [2]  (c)  two different atoms of sodium are na1123 and na1124.  (i)  explain why these two atoms are isotopes.   .   ...   [2]  (ii)  na1124 is radioactive. it changes into an atom of a different element which has one more  proton.   identify this element.   ...   [1]  (iii)  state two uses of radioactive isotopes.   .   ...   [2] [total: 13]",
            "3": "3 0620/31/o/n/15 \u00a9 ucles 2015 [turn over2  describe how to separate the following. in each example, give a description of the procedure used  and explain why this method works.  (a)  copper powder from a mixture containing copper and zinc powders.  procedure  ..     explanation      [3]  (b)  nitrogen from a mixture of nitrogen and oxygen.  procedure  ..     explanation      [3]  (c)  glycine from a mixture of the two amino acids glycine and alanine. glycine has the lower rf  value.  procedure  ..     explanation      [2]  (d)  magnesium hydroxide from a mixture of magnesium hydroxide and zinc hydroxide.  procedure  ..     explanation      [3] [total: 11]",
            "4": "4 0620/31/o/n/15 \u00a9 ucles 20153  sulfuric acid is made by the contact process.  (a)  sulfur is burned by spraying droplets of molten sulfur into air.   suggest and explain an advantage of using this method.      ..   [2]  (b)  the following equation represents the equilibrium in the contact process. 2so2(g)  +  o2(g)    2so3(g)   oxygen is supplied from the air.   the composition of the reaction mixture is 1 volume of sulfur dioxide to 1 volume of oxygen.   what volume of air contains 1 dm3 of oxygen?   ...  dm3  [1]  (c)  sulfur dioxide is more expensive than air.   what is the advantage of using an excess of air?      ..   [2]  (d)  the forward reaction is exothermic. the reaction is usually carried out at a temperature between  400 and 450 \u00b0c.  (i)  what is the effect on the position of equilibrium of using a temperature above 450 \u00b0c?   explain your answer.   .   .   ...   [2]  (ii)  what is the effect on the rate of using a temperature below 400 \u00b0c?   explain your answer.   .   .   ...   [3]",
            "5": "5 0620/31/o/n/15 \u00a9 ucles 2015 [turn over (e)  a low pressure, 2 atmospheres, is used. at equilibrium, about 98% so3 is present.  (i)  what is the effect on the position of equilibrium of using a higher pressure?   ...   [1]  (ii)  explain why a higher pressure is not used.   ...   [1]  (f)  name the catalyst used in the contact process.   ..   [1]  (g)  describe how concentrated sulfuric acid is made from sulfur trioxide.            ..   [2] [total: 15]",
            "6": "6 0620/31/o/n/15 \u00a9 ucles 20154 (a)  synthetic polymers are disposed of in landfill sites and by burning.  (i)  describe two problems caused by the disposal of synthetic polymers in landfill sites.   .   ...   [2]  (ii)  describe one problem caused by burning synthetic polymers.   ...   [1]  (b)  state two uses of synthetic polymers.      ..   [1]  (c)  the structural formulae of two synthetic polymers are given below. polymer a polymer b co co c co o o o o och2 ch3 ch3ch ch2ch  (i)  draw the structural formula of the monomer of polymer a. [2]  (ii)  identify the functional group circled in polymer b.   ...   [1]  (iii)  deduce the two types of organic compound which have reacted to form polymer b.   ...   [2]",
            "7": "7 0620/31/o/n/15 \u00a9 ucles 2015 [turn over (d)  explain the difference between addition and condensation polymers. classify a and b as  either addition or condensation polymers.            ..   [3] [total: 12]",
            "8": "8 0620/31/o/n/15 \u00a9 ucles 20155 (a)  a compound, x, contains 55.85% carbon, 6.97% hydrogen and 37.18% oxygen.  (i)  how does this prove that compound x contains only carbon, hydrogen and oxygen?   ...   [1]  (ii)  use the above percentages to calculate the empirical formula of compound x.   ...   [2]  (iii)  the mr of x is 86.   what is its molecular formula?   ...   [2]  (b) (i)  bromine water changes from brown to colourless when added to x.   what does this tell you about the structure of x?   ...   [1]  (ii)  magnesium powder reacts with an aqueous solution of x. hydrogen is evolved.   what does this tell you about the structure of x?   ...   [1]  (iii)  x contains two different functional groups.   draw a structural formula of x. [1] [total: 8]",
            "9": "9 0620/31/o/n/15 \u00a9 ucles 2015 [turn over6  carbon and silicon are elements in group iv. they both form oxides of the type xo2.  (a)  silicon( iv) oxide, sio2, has a macromolecular structure.  (i)  describe the structure of silicon( iv) oxide.   .   .   .   .   ...   [3]  (ii)  state three properties which silicon( iv) oxide and diamond have in common.   .   .   ...   [3]  (iii)  how could you show that silicon( iv) oxide is acidic and not basic or amphoteric?   .   .   ...   [2]  (b)  explain why the physical properties of carbon dioxide are different from those of diamond and  silicon( iv) oxide.      ..   [1] [total: 9]",
            "10": "10 0620/31/o/n/15 \u00a9 ucles 20157  the rate of a photochemical reaction is affected by light.  (a)  the decomposition of silver bromide is the basis of film photography. this is a redox reaction. 2agbr  \u2192  2ag  +  br2  cream black  step 1 2br \u2013  \u2192  br2  +  2e\u2013  step 2 ag+  +  e\u2013  \u2192  ag  (i)  which step is reduction? explain your answer.   ...   [1]  (ii)  which ion is the oxidising agent? explain your answer.   ...   [1]  (b)  a piece of white paper was coated with silver bromide and exposed to the light. sections of the  paper were covered as shown in the diagram. not covered covered with thin paper covered with thick cardpaper coated wit h silver bromid e   predict the appearance of the different sections of the paper after exposure to the light and the  removal of the card. explain your predictions.                  ..   [4]",
            "11": "11 0620/31/o/n/15 \u00a9 ucles 2015 [turn over (c)  photosynthesis is another example of a photochemical reaction. green plants can make simple  carbohydrates, such as glucose. these can polymerise to make more complex carbohydrates, such as starch.  (i)  write a word equation for photosynthesis.   ...   [2]  (ii)  name the substance which is responsible for the colour in green plants and is essential for  photosynthesis.   ...   [1]  (iii)  the structural formula of glucose can be represented by   h h o o  .   draw part of the structural formula of starch which contains two glucose units. [2]  (iv)  living organisms need carbohydrates for respiration.   what is meant by respiration ?   ...   [1] [total: 12]",
            "12": "12 0620/31/o/n/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. group 140 ce ceriu m 58141 pr praseodymium 59144 nd neodymium 60pm promethiu m 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactiniu m 91238 u uraniu m 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californiu m 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithiu m 3 23 na sodium 1124 mg magnesiu m 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromiu m 2455 mn manganes e 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga galliu m 3127 al aluminium 1311 b boron 512 c carbo n 614 n nitroge n 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphoru s 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmiu m 48115 in indium 49119 sn tin 50122 sb antimony 51128 te telluriu m 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanu m 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rheniu m 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4i ii iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r .t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numbe rkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the element s"
        },
        "0620_w15_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 (extended) october/november 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 12 printed pages. [turn overib15 11_0620_32/fp \u00a9 ucles 2015 *7234333226* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/32/o/n/15 \u00a9 ucles 20151  use your copy of the periodic table to help you answer some of these questions.  (a)  predict the formulae of the following compounds.  (i)  nitrogen \ufb02 uoride  ..  (ii)  phosphorus sul \ufb01 de  . [2]  (b)  deduce the formulae of the following ions.  (i)  selenide  . .  (ii)  gallium  .. .. [2]  (c)  use the following ions to determine the formulae of the compounds.  ions oh\u2013      cr3+      ba2+      so42\u2013  compounds  (i)  chromium( iii) sulfate  ..  (ii)  barium hydroxide  . ... [2] [total: 6]",
            "3": "3 0620/32/o/n/15 \u00a9 ucles 2015 [turn over2 (a)  polluted air contains two oxides of carbon and two oxides of nitrogen. a major source of these  pollutants is motor vehicles.  (i)  describe how carbon dioxide and carbon monoxide are formed in motor vehicle engines.   .    .    .    . ..  [3]  (ii)  state one adverse effect of each of these gases.   .    . ..  [2]  (iii)  nitrogen monoxide, no, is released by motor vehicle exhausts.   explain how nitrogen monoxide is formed in motor vehicle engines.   .    . ..  [2]  (iv)  when nitrogen monoxide is released into the atmosphere, nitrogen dioxide, no2, is formed.   suggest an explanation why this happens.   . ..  [1]  (b)  predict the possible adverse effect on the environment when this non-metal oxide, no2, reacts  with water and oxygen.   ... .   ... ...  [2]  (c)  how are the amounts of carbon monoxide and nitrogen monoxide emitted by modern motor vehicles reduced? include an equation in your answer.   ... .   ... .   ... ...  [3] [total: 13]",
            "4": "4 0620/32/o/n/15 \u00a9 ucles 20153  two of the main uses of zinc are for galvanising and for making alloys.   one of the main ores of zinc is zinc blende, zns. there are two stages in the extraction of zinc from  this ore.  (a)  stage 1   zinc oxide is made from zinc blende.   describe how this is done and write a word equation for the reaction.   ... .   ... .   ... ...  [2]  (b)  stage 2   zinc oxide is reduced to zinc.   write a word equation for the reduction of zinc oxide by coke.   ... ...  [1]  (c)  the zinc produced by this process is impure. it can be puri \ufb01 ed by electrolysis using a method  which is similar to the puri \ufb01 cation of copper. under the conditions used in the process, zinc is  the product at the negative electrode (cathode).   complete the following description of this puri \ufb01 cation.   the electrolyte is aqueous  . .  [1]   the negative electrode (cathode) is made of   .  [1]   the positive electrode (anode) is impure zinc.   the equation for the reaction at the cathode is  . .  [1]   the equation for the reaction at the anode is   .  [1]  explain why the concentration of the electrolyte does not change.   ... .   ... ...  [2]",
            "5": "5 0620/32/o/n/15 \u00a9 ucles 2015 [turn over (d)  brass is an alloy which contains zinc.  (i)  name the other metal in brass.   . ..  [1]  (ii)  suggest two reasons why an alloy such as brass is preferred to either of its constituent  metals.   .    . ..  [2]  (e)  in an experiment to investigate the rate of rusting of steel, three pieces of steel were used. one  piece of steel was completely coated with copper, one piece completely coated with zinc and the third piece was left uncoated. all three pieces were left exposed to the atmosphere.  (i)  explain why the uncoated piece started to rust.   .    . ..  [1]  (ii)  the coating on both of the other two pieces was scratched, exposing the steel. exposed steel does not rustthin layer of zinc steel   the piece of steel coated with zinc still did not rust but the copper-coated piece of steel  rusted very rapidly.   explain these observations in terms of the formation of ions and the transfer of electrons.   .    .    .    .    . ..  [4] [total: 17]",
            "6": "6 0620/32/o/n/15 \u00a9 ucles 20154 (a)  propane reacts with chlorine to form a mixture of chloropropanes. this is a photochemical  reaction.  (i)  what is meant by the phrase photochemical reaction ?   .    . ..  [1]  (ii)  the products of this reaction include two isomers, one of which has the following structural formula. ch hh ch hch hcl   draw the structural formula of the other isomer. [1]  (iii)  explain why these two different compounds are isomers.   .    . ..  [2]",
            "7": "7 0620/32/o/n/15 \u00a9 ucles 2015 [turn over (b)  bond breaking is an endothermic change and bond forming is an exothermic change.   bond energy is the amount of energy in kj / mol needed to break one mole of the speci \ufb01 ed  bond. ch hh ch hcc lcl clhh h+ + \u2192 ch hhh ch hch hcl   use the following bond energies to determine whether this reaction is exothermic or endothermic. you must show your reasoning. bondbond energies in kj / mol c\u2013c l 338 c\u2013h 412 cl \u2013c l 242 h\u2013c l 431 c\u2013c 348   ... .   ... .   ... .   ... ...  [3]",
            "8": "8 0620/32/o/n/15 \u00a9 ucles 2015 (c) (i)   chloropropane can be hydrolysed to propanol, ch3ch2ch2oh, by sodium hydroxide.   write the equation for this reaction.   . ..  [2]  (ii)  propanol can be dehydrated. it loses a water molecule to form a hydrocarbon.   give the name and structural formula of this hydrocarbon.  name . structural formula [2]  (iii)  propanol is oxidised to a carboxylic acid by acidi \ufb01 ed potassium manganate( vii).   deduce the name of this acid.   . ..  [1]  (d)  propanol reacts with methanoic acid to form the ester propyl methanoate. ch3ch2ch2oh  +  hcooh  \u2192  hcooch2ch2ch3  +  h2o   4.0 g of methanoic acid was reacted with 6.0 g of propanol.  (i)  calculate the mr of methanoic acid =  [1]  (ii)  calculate the mr of propanol =  [1]  (iii)  determine which one is the limiting reagent. show your reasoning.   .    .    . ..  [2]  (iv)  calculate the maximum yield in grams of propyl methanoate, mr = 88.   . ..  [1] [total: 17]",
            "9": "9 0620/32/o/n/15 \u00a9 ucles 2015 [turn over5  iron is extracted from its ore, hematite, in a blast furnace.  substances added to the furnace are:  \u2022  iron ore, hematite, containing impurities such as silica, sio2  \u2022  air  \u2022  coke, c  \u2022  limestone, caco3   substances formed in the blast furnace are:  \u2022  molten iron  \u2022  molten slag  \u2022  waste gases such as carbon dioxide  (a)  state the two functions of the coke used in the blast furnace.   ... .   ... ...  [2]  (b)  write an equation for the conversion of hematite, fe2o3, to iron.   ... ...  [2]  (c)  explain how the silica impurity is removed and separated from the molten iron.   ... .   ... .   ... .   ... ...  [3]  (d)  the molten iron from the furnace is impure.   it contains impurities which include the element carbon.  explain how the carbon is removed. include an equation in your answer.  ... .   ... .   ... ...  [3] [total: 10]",
            "10": "10 0620/32/o/n/15 \u00a9 ucles 20156  the table below shows the elements in the third period of the periodic table, the number of  electrons in their outer energy level, their oxidation state in their common compounds and their melting points. element na mg a l si p s c l ar number of outer electrons 12345678 oxidation state +1 +2 +3 +4 / \u20134 \u20133 \u20132 \u20131 0melting point / \u00b0c 98 650 660 1414 317 115 \u2013101 \u2013189  (a)  describe and explain the variation in oxidation state across the period.   ... .   ... .   ... ...  [3]  (b)  the \ufb01 rst three elements, na, mg and a l, are metals.   describe the structure of a typical metal.   ... .   ... .   ... ...  [3]  (c)  explain why na, mg and a l are good conductors of electricity.   ... ...  [1]  (d)  which element exists as diatomic molecules of the type x 2?   ... ...  [1]  (e)  silicon has a similar structure to diamond.   explain why silicon has the highest melting point in the period.   ... .   ... ...  [2]",
            "11": "11 0620/32/o/n/15 \u00a9 ucles 2015 [turn over (f)  sodium chloride is a crystalline solid with a high melting point. it dissolves in water to give a  neutral solution. phosphorus trichloride is a liquid at room temperature. it reacts with water to form an acidic solution.   suggest an explanation for these differences in properties.   ... .   ... .   ... ...  [2]  (g)  describe how you could show that magnesium oxide is a basic oxide and not an amphoteric  oxide.   ... .   ... ...  [2]  (h)  draw a dot-and-cross diagram showing the bonding in magnesium oxide. show outer electrons  only. [3] [total: 17]",
            "12": "12 0620/32/o/n/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w15_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs./g39/g82/g3/g81/g82/g87/g3/g88/g86/g72/g3/g86/g87/g68/g83/g79/g72/g86/g15/g3/g83/g68/g83/g72/g85/g3/g70/g79/g76/g83/g86/g15/g3/g74/g79/g88/g72/g3/g82/g85/g3/g70/g82/g85/g85/g72/g70/g87/g76/g82/g81/g3/g192/g88/g76/g71/g17do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 (extended) october/november 2015  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations /g38/g68/g80/g69/g85/g76/g71/g74/g72/g3/g44/g81/g87/g72/g85/g81/g68/g87/g76/g82/g81/g68/g79/g3/g42/g72/g81/g72/g85/g68/g79/g3/g38/g72/g85/g87/g76/g191/g70/g68/g87/g72/g3/g82/g73/g3/g54/g72/g70/g82/g81/g71/g68/g85/g92/g3/g40/g71/g88/g70/g68/g87/g76/g82/g81 this document consists of 12 printed pages. [turn overib15 11_0620_33/fp \u00a9 ucles 2015 /;#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23#23#23#23#23#23#23/;#23#23#23#23#23#23 /g55/g75/g72/g3/g86/g92/g79/g79/g68/g69/g88/g86/g3/g76/g86/g3/g68/g83/g83/g85/g82/g89/g72/g71/g3/g73/g82/g85/g3/g88/g86/g72/g3/g76/g81/g3/g40/g81/g74/g79/g68/g81/g71/g15/g3/g58/g68/g79/g72/g86/g3/g68/g81/g71/g3/g49/g82/g85/g87/g75/g72/g85/g81/g3/g44/g85/g72/g79/g68/g81/g71/g3/g68/g86/g3/g68/g3/g38/g68/g80/g69/g85/g76/g71/g74/g72/g3/g44/g81/g87/g72/g85/g81/g68/g87/g76/g82/g81/g68/g79/g3/g47/g72/g89/g72/g79/g3/g20/g18/g47/g72/g89/g72/g79/g3/g21/g3/g38/g72/g85/g87/g76/g191/g70/g68/g87/g72 /g17",
            "2": "2 0620/33/o/n/15 \u00a9 ucles 20151 (a)   describe a chemical test which shows the presence of water.   test  .    colour change if water is present   ...   ... . [3]  (b)  how could you show that a sample of water is pure?   ... ...  [1]  (c)  describe how water is treated before it is supplied to homes and industry.   ... .   ... ...  [2]  (d)  state two industrial uses of water.   ... .   ... ...  [2] [total: 8] 2  choose from the following list of gases. a gas may be chosen once, more than once or not at all.  sulfur dioxide hydrogen methane carbon monoxide  argon ethene butane (a)  it is used to bleach wood pulp.    [1]  (b)  when burned in oxygen, the only product is water.  .  [1]  (c)  it can polymerise.  ... .  [1]  (d)  it is used to provide an inert atmosphere for welding.  .  [1]  (e)  when reacted with oxygen, the only product is carbon dioxide.  ..  [1]  (f)  it is produced by the decay of vegetation in the absence of oxygen.  ..  [1] [total: 6]",
            "3": "3 0620/33/o/n/15 \u00a9 ucles 2015 [turn over3  lithium bromide is an ionic compound. it can be electrolysed when it is molten or in aqueous  solution. it cannot be electrolysed as a solid.  (a)  solid lithium bromide is a poor conductor of electricity. the ions cannot move to the electrodes,  they are held in an ionic lattice by strong forces.  (i)  describe the motion of the ions in the solid state.   . ..  [1]  (ii)/g3/g3/g39/g72/g191/g81/g72/g3/g87/g75/g72/g3/g87/g72/g85/g80/g3 ionic bonding .   .    . ..  [2]  (iii)  what is meant by the term ionic lattice ?   .    . ..  [2]  (b) the diagram shows the electrolysis of molten lithium bromide. + \u2013 carbon electrodespower pack molten lithium bromide heat  (i)/g3/g3/g48/g68/g85/g78/g3/g82/g81/g3/g87/g75/g72/g3/g71/g76/g68/g74/g85/g68/g80/g3/g87/g75/g72/g3/g71/g76/g85/g72/g70/g87/g76/g82/g81/g3/g82/g73/g3/g87/g75/g72/g3/g72/g79/g72/g70/g87/g85/g82/g81/g3/g192/g82/g90/g17/g3 /g62/g20/g64  (ii)  write an ionic equation for the reaction at the negative electrode (cathode).   . ..  [1]  (iii)  write an ionic equation for the reaction at the positive electrode (anode).   . ..  [2]  (iv)  which ion is oxidised? explain your answer.   .    . ..  [2]",
            "4": "4 0620/33/o/n/15 \u00a9 ucles 2015 (c)  when aqueous lithium bromide is electrolysed, a colourless gas is formed at the negative  electrode and the solution becomes alkaline.   explain these observations and include an equation in your explanation.   ... .   ... .   ... .   ... ...  [3] [total: 14] 4  two homologous series of hydrocarbons are the alkanes and the alkenes.  (a) (i)   one general characteristic of a homologous series is that the physical properties vary in a  predictable way.   state three  other general characteristics of a homologous series.   .    .    . ..  [3]  (ii)  how can the molecular formula of a hydrocarbon show whether it is an alkane or an  alkene?   .    . ..  [2]  (iii)  how do alkanes and alkenes differ in their molecular structures?   .    . ..  [2]",
            "5": "5 0620/33/o/n/15 \u00a9 ucles 2015 [turn over (b)  cracking is the thermal decomposition of alkanes into smaller hydrocarbons and possibly  hydrogen.  (i)  state two conditions required for the cracking of an alkane.   . ..  [2]  (ii)  one type of cracking produces an alkane and an alkene.   complete an equation for the cracking of heptane into an alkane and an alkene.  c7h16  /g111    +   [1]  (iii)  complete an equation for the cracking of heptane into hydrogen and two other products.  c7h16  /g111    +    +  h2 [1]  (iv) suggest one reason why cracking is important.   . ..  [1]  (c)  hydrocarbons burn in excess oxygen to form carbon dioxide and water. 20 cm3 of a gaseous  hydrocarbon burned in an excess of oxygen, 200 cm3. after cooling, the volume of the residual  gas at r.t.p. was 150 cm3, 50 cm3 of which was oxygen.  (i)  determine the volume of the oxygen used.   . ..  [1]  (ii)  determine the volume of the carbon dioxide formed.   . ..  [1]  (iii)  the hydrocarbon was an alkane.   determine the formula of the hydrocarbon. [1] [total: 15]",
            "6": "6 0620/33/o/n/15 \u00a9 ucles 20155  sulfuric acid is a strong acid. in aqueous solution, it ionises as shown below. h2so4  /g111  2h+  +  so42\u2013  (a) (i)   what is meant by the term acid ?   . ..  [1]  (ii)  sulfurous acid, h2so3, is a weak acid.   state the difference between a weak acid and a strong acid.   .    . ..  [2]  (b)/g3/g3/g54/g88/g79/g73/g88/g85/g82/g88/g86/g3/g68/g70/g76/g71/g3/g73/g82/g85/g80/g86/g3/g86/g68/g79/g87/g86/g3/g70/g68/g79/g79/g72/g71/g3/g86/g88/g79/g191/g87/g72/g86/g15/g3/g90/g75/g76/g70/g75/g3/g70/g82/g81/g87/g68/g76/g81/g3/g87/g75/g72/g3/g76/g82/g81/g3/g54/g5032\u2013.   when barium nitrate solution is added to aqueous sulfurous acid, a white precipitate, a, forms.   bromine water changes from brown to colourless when added to aqueous sulfurous acid. /g3/g3 /g37/g85/g82/g80/g76/g81/g72/g3 /g82/g91/g76/g71/g76/g86/g72/g86/g3 /g86/g88/g79/g73/g88/g85/g82/g88/g86/g3 /g68/g70/g76/g71/g17/g3 /g58/g75/g72/g81/g3 /g87/g75/g76/g86/g3 /g86/g82/g79/g88/g87/g76/g82/g81/g3 /g76/g86/g3 /g87/g72/g86/g87/g72/g71/g3 /g90/g76/g87/g75/g3 /g68/g70/g76/g71/g76/g191/g72/g71/g3 /g69/g68/g85/g76/g88/g80/g3 /g81/g76/g87/g85/g68/g87/g72/g3 solution, a different white precipitate, b, is formed.  (i)  identify the white precipitate, a.   . ..  [1]  (ii)  identify the white precipitate, b.   . ..  [1]  (iii)  write an ionic equation for the reduction of the bromine molecule.   . ..  [1]  (iv)  name the product formed by the oxidation of sulfurous acid.   . ..  [1]",
            "7": "7 0620/33/o/n/15 \u00a9 ucles 2015 [turn over (c)  complete the following word equations.  (i)  magnesium hydroxide + dilute sulfuric acid   . ..  [1]  (ii)  zinc + dilute sulfuric acid   . ..  [1]  (iii)  copper carbonate + dilute sulfuric acid   . ..  [1]  (d)  write equations for the reaction of dilute sulfuric acid with each of the following.  (i)  ammonia   . ..  [2]  (ii) sodium hydroxide   . ..  [2]  (iii)  iron   . ..  [2] [total: 16]",
            "8": "8 0620/33/o/n/15 \u00a9 ucles 20156  a reactivity series of metals is given below. metal name symbol most reactive least reactivesodium na lithium li magnesium mg zinc zn manganese mn iron fe copper cu rhodium rh  (a)  which two metals will react most vigorously with cold water?   ... ...  [1]  (b)  which two metals will not react with dilute hydrochloric acid?   ... ...  [1]  (c)  deduce the formula of iron( iii) sulfate.   ... ...  [1]  (d)  what is the formula of a magnesium ion?   ... ...  [1]  (e)  describe a test-tube experiment which will show that manganese is more reactive than copper.   ... .   ... .   ... ...  [3]",
            "9": "9 0620/33/o/n/15 \u00a9 ucles 2015 [turn over (f)  manganese is a typical transition metal.  predict three physical and two chemical properties of this metal.  physical properties  ... .   ... .   ... .  chemical properties  ... .   ... . [5] [total: 12]",
            "10": "10 0620/33/o/n/15 \u00a9 ucles 20157  two salts can be made from potassium hydroxide and sulfuric acid. they are potassium sulfate,  k2so4, and the acid salt potassium hydrogen sulfate, khso4. they are both made by titration. conical flaskburette filled with sulfuric acid 25.0  cm3 of potassium hydroxide solution  (a)  25.0 cm3 of potassium hydroxide, concentration 2.53 mol / dm3, was neutralised by 28.2 cm3 of  dilute sulfuric acid. 2koh(aq)  +  h2so4(aq)  /g111  k2so4(aq)  +  2h2o(l)   calculate the concentration of the sulfuric acid.   number of moles of koh used =    number of moles of h2so4 needed to neutralise the koh =    concentration of dilute sulfuric acid =  mol / dm3 [3]  (b)/g3/g3/g44/g81/g3 /g87/g75/g72/g3 /g70/g82/g81/g76/g70/g68/g79/g3 /g192/g68/g86/g78/g3 /g87/g75/g72/g85/g72/g3 /g76/g86/g3 /g68/g3 /g81/g72/g88/g87/g85/g68/g79/g3 /g86/g82/g79/g88/g87/g76/g82/g81/g3 /g82/g73/g3 /g83/g82/g87/g68/g86/g86/g76/g88/g80/g3 /g86/g88/g79/g73/g68/g87/g72/g3 /g90/g75/g76/g70/g75/g3 /g86/g87/g76/g79/g79/g3 /g70/g82/g81/g87/g68/g76/g81/g86/g3 /g87/g75/g72/g3 indicator used in the titration.  (i)  describe how you could obtain a solution of potassium sulfate without the indicator.   .    . ..  [2]  (ii)  potassium hydrogen sulfate can be made by the following reaction. koh(aq)  +  h2so4(aq)  /g111  khso4(aq)  +  h2o(l)   suggest how you could make a solution of potassium hydrogen sulfate without using an  indicator.   .    .    . ..  [2]",
            "11": "11 0620/33/o/n/15 \u00a9 ucles 2015 [turn over (c)  describe a test which would distinguish between aqueous solutions of potassium sulfate and  sulfuric acid.  test   .  result  ..  [2] [total: 9]",
            "12": "12 0620/33/o/n/15 \u00a9 ucles 2015to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. group 140 ce cerium 58141 pr praseodymium 59144 nd neodymium 60pm promethium 61150 sm samarium 62152 eu europium 63157 gd gadolinium 64159 tb terbium 65162 dy dysprosium 66165 ho holmium 67167 er erbium 68169 tm thulium 69173 yb ytterbium 70175 lu lutetium 71 232 th thorium 90pa protactinium 91238 u uranium 92np neptunium 93pu plutonium 94am americium 95cm curium 96bk berkelium 97cf californium 98es einsteinium 99fm fermium 100md mendelevium 101no nobelium 102lr lawrencium 1031 h hydrogen 1 7 li lithium 3 23 na sodium 1124 mg magnesium 12 40 ca calcium 2045 sc scandium 2148 ti titanium 2251 v vanadium 2352 cr chromium 2455 mn manganese 2556 fe iron 2659 co cobalt 2759 ni nickel 2864 cu copper 2965 zn zinc 3070 ga gallium 3127 al aluminium 1311 b boron 512 c carbon 614 n nitrogen 716 o oxygen 819 f fluorine 9 28 si silicon 1431 p phosphorus 1532 s sulfur 1635.5 cl chlorine 1740 ar argon 1820 ne neon 104 he helium 2 73 ge germanium 3275 as arsenic 3379 se selenium 3480 br bromine 3584 kr krypton 3639 k potassium 19 88 sr strontium 3889 y yttrium 3991 zr zirconium 4093 nb niobium 4196 mo molybdenum 42tc technetium 43101 ru ruthenium 44103 rh rhodium 45106 pd palladium 46108 ag silver 47112 cd cadmium 48115 in indium 49119 sn tin 50122 sb antimony 51128 te tellurium 52127 i iodine 53131 xe xenon 54 137 ba barium 56139 la lanthanum 57        *178 hf hafnium 72181 ta tantalum 73184 w tungsten 74186 re rhenium 75190 os osmium 76192 ir iridium 77195 pt platinum 78197 au gold 79201 hg mercury 80204 tl thallium 81207 pb lead 82209 bi bismuth 83po polonium 84at astatine 85rn radon 86 fr francium 87227 ac actinium 899 be beryllium 4ii i iii iv v vi vii 0 85 rb rubidium 37 133 cs caesium 55 226 ra radium 88 the volume of one mole of any gas is 24 dm3at room temperature and pressure (r.t.p.).a x ba = relative atomic mass x = atomic symbol b = proton (atomic) numberkey*58-71 lanthanoid series 90-103 actinoid seriesdata sheet the periodic table of the elements"
        },
        "0620_w15_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test october/november 2015  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib15 11_0620_51/3rp\u00a9 ucles 2015 *3376642215* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/51/o/n/15 \u00a9 ucles 20151  you are going to investigate the rate of reaction when magnesium ribbon reacts with four solutions  of dilute sulfuric acid, of different concentrations, labelled solutions a, b, c and d. the sulfuric acid  is in excess in all experiments.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out \ufb01 ve experiments.  (a) experiment 1   using a measuring cylinder, pour 30 cm3 of dilute sulfuric acid a into the beaker.   start the timer and add the 4 cm length of magnesium to the sulfuric acid in the beaker.   stir the mixture constantly.   measure the time taken for all of the magnesium to react and disappear.   record the time in the table below.   rinse out the beaker with distilled water.  (b) experiment 2   repeat experiment 1, using the solution b of sulfuric acid. record the time in the table.  (c) experiment 3   repeat experiment 1, using the solution c of sulfuric acid. record the time in the table.  (d) experiment 4   repeat experiment 1, using the solution d of sulfuric acid. record the time in the table. experiment numbersolution of sulfuric acidconcentration of sulfuric acid in mol / dm3time for magnesium to completely disappear in seconds 1 a 1.0 2 b 0.8 3 c 0.6 4 d 0.5 [4]  (e)  experiment 5   pour about 3 cm3 of the solution c of sulfuric acid into a test-tube and record its temperature.  add a 4 cm length of magnesium.   record all of your observations and test the gas given off with a splint.   ... .   ... .   ... ...  [2]",
            "3": "3 0620/51/o/n/15 \u00a9 ucles 2015 [turn over (f)  plot the results for experiments 1, 2, 3 and 4 on the grid and draw a smooth line graph. 0 0.2 0.4 0.6 concentration of sulfuric acid in mol  / dm3time in seconds 0.8 1.0 1.2180 160140120100 80604020 0 [3]  (g) (i)   from your graph , deduce the concentration of the sulfuric acid if the time for the reaction  was 80 s.   show clearly on the graph  how you worked out your answer.   mol / dm3  [2]",
            "4": "4 0620/51/o/n/15 \u00a9 ucles 2015 (ii)  from your graph , deduce how long the reaction would take if a solution of sulfuric acid of  concentration 1.2 mol / dm3 was used.   show clearly on the graph  how you worked out your answer.  s  [2]  (h)  why was the same amount of magnesium used in experiments 1, 2, 3 and 4?   ... ...  [1]  (i)  use your observations in experiment 5 to answer these questions.  (i)  what type of chemical reaction occurs when magnesium reacts with sulfuric acid?   . ..  [1]  (ii)  identify the gas given off.   . ..  [1]  (iii)  suggest the effect on the temperature change if this experiment was repeated using 2 cm  of magnesium ribbon.   .    . ..  [1]  (j)  suggest a different method which could be used to investigate the rate of the reaction between magnesium and sulfuric acid. state the difference in the apparatus used and measurements to be taken.  apparatus  ...   measurements   ...   ... .   ... ...  [3] [total: 20]",
            "5": "5 0620/51/o/n/15 \u00a9 ucles 2015 [turn over2  you are provided with two metal salt solutions, x and y.   carry out the following tests on x and y, recording all of your observations in the tables.   conclusions must not be written in the tables. tests observations tests on solution x (a)  describe the appearance of solution x.   [1] divide the solution into four equal portions in  separate test-tubes. (b)  to the \ufb01 rst portion of solution add about  1 cm3 of dilute nitric acid followed by  aqueous silver nitrate.   [2] (c)  to the second portion of solution add about  1 cm3 of aqueous sodium hydroxide and  shake the mixture and leave to stand.   note how the mixture changes after \ufb01 ve  minutes.  [1]   [1] (d)  to the third portion of solution add excess  aqueous ammonia.   [1] (e)  to the fourth portion of solution add a few drops of dilute sulfuric acid followed by about 1 cm 3 of aqueous potassium  manganate( vii).   now add aqueous sodium hydroxide to the  mixture.  [1]   [2]",
            "6": "6 0620/51/o/n/15 \u00a9 ucles 2015tests observations tests on solution y divide the solution into three equal portions in  separate test-tubes. (f)  to the \ufb01 rst portion of the solution add about  1 cm3 of dilute hydrochloric acid.   [1] (g)  tip the second portion of the solution into  a boiling tube. add about 1 cm3 of aqueous  sodium hydroxide and shake the mixture.   add one small piece of aluminium foil to the mixture and warm gently. test the gas given off with red litmus paper. ..   [3] (h)  to the third portion of the solution add  aqueous potassium iodide.   [2]  (i)  what conclusions can you draw about solution x?   ... .   ... ...  [3]  (j)  what conclusions can you draw about solution y?   ... .   ... ...  [2] [total: 20]",
            "7": "7 0620/51/o/n/15 \u00a9 ucles 2015blank page",
            "8": "8 0620/51/o/n/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series.cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_w15_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/52   paper 5 practical test october/november 2015  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructions cambridge international examinations cambridge international general certificate of secondary education this document consists of 7 printed pages and 1 blank page. [turn overib15 11_0620_52/fp\u00a9 ucles 2015 *6783073891* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/52/o/n/15 \u00a9 ucles 20151  you are going to investigate the rate of reaction when magnesium ribbon reacts with four solutions  of dilute sulfuric acid, of different concentrations, labelled solutions a, b, c and d. the sulfuric acid  is in excess in all experiments.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out five experiments.  (a) experiment 1   using a measuring cylinder, pour 30 cm3 of dilute sulfuric acid a into the beaker.   start the timer and add the 4 cm length of magnesium to the sulfuric acid in the beaker.   stir the mixture constantly.   measure the time taken for all of the magnesium to react and disappear.   record the time in the table below.   rinse out the beaker with distilled water.  (b) experiment 2   repeat experiment 1, using the solution b of sulfuric acid. record the time in the table.  (c) experiment 3   repeat experiment 1, using the solution c of sulfuric acid. record the time in the table.  (d) experiment 4   repeat experiment 1, using the solution d of sulfuric acid. record the time in the table. experiment numbersolution of sulfuric acidconcentration of sulfuric acid in mol / dm3time for magnesium to completely disappear in seconds 1 a 1.0 2 b 0.8 3 c 0.6 4 d 0.5 [4]  (e)  experiment 5   pour about 3 cm3 of the solution c of sulfuric acid into a test-tube and record its temperature.  add a 4 cm length of magnesium.   record all of your observations and test the gas given off with a splint.         ..   [2]",
            "3": "3 0620/52/o/n/15 \u00a9 ucles 2015 [turn over (f)  plot the results for experiments 1, 2, 3 and 4 on the grid and draw a smooth line graph. 0 0.2 0.4 0.6 concentration of sulfuric acid in mo l / dm3time in seconds 0.8 1.0 1.2180 160 140 120 100 80 60 40 20 0 [3]  (g) (i)  from your graph, deduce the concentration of the sulfuric acid if the time for the reaction  was 80 s.   show clearly on the graph  how you worked out your answer.   mol / dm3  [2]",
            "4": "4 0620/52/o/n/15 \u00a9 ucles 2015 (ii)  from your graph, deduce how long the reaction would take if a solution of sulfuric acid of  concentration 1.2 mol / dm3 was used.   show clearly on the graph  how you worked out your answer.  s  [2]  (h)  why was the same amount of magnesium used in experiments 1, 2, 3 and 4?   ..   [1]  (i)  use your observations in experiment 5 to answer these questions.  (i)  what type of chemical reaction occurs when magnesium reacts with sulfuric acid?   ...   [1]  (ii)  identify the gas given off.   ...   [1]  (iii)  suggest the effect on the temperature change if this experiment was repeated using 2 cm  of magnesium ribbon.   .   ...   [1]  (j)  suggest a different method which could be used to investigate the rate of the reaction between  magnesium and sulfuric acid. state the difference in the apparatus used and measurements to be taken.  apparatus  ...  measurements  ...      ..   [3] [total: 20]",
            "5": "5 0620/52/o/n/15 \u00a9 ucles 2015 [turn over2  you are provided with two metal salt solutions, x and y.   carry out the following tests on x and y, recording all of your observations in the tables.   conclusions must not be written in the tables. tests observations tests on solution x (a)  describe the appearance of solution x.   [1] divide the solution into four equal portions in  separate test-tubes. (b)  to the first portion of solution add about  1 cm3 of dilute nitric acid followed by  aqueous silver nitrate.   [2] (c)  to the second portion of solution add about  1 cm3 of aqueous sodium hydroxide and  shake the mixture and leave to stand.   note how the mixture changes after five minutes.  [1]   [1] (d)  to the third portion of solution add excess  aqueous ammonia.   [1] (e)  to the fourth portion of solution add a few drops of dilute sulfuric acid followed  by about 1 cm 3 of aqueous potassium  manganate( vii).   now add aqueous sodium hydroxide to the  mixture.  [1]   [2]",
            "6": "6 0620/52/o/n/15 \u00a9 ucles 2015tests observations tests on solution y divide the solution into three equal portions in  separate test-tubes. (f)  to the first portion of the solution add about  1 cm3 of dilute hydrochloric acid.   [1] (g)  tip the second portion of the solution into a boiling tube. add about 1 cm 3 of aqueous  sodium hydroxide and shake the mixture.   add one small piece of aluminium foil to the mixture and warm gently. test the gas given off with red litmus paper. ..   [3] (h)  to the third portion of the solution add  aqueous potassium iodide.   [2]  (i)  what conclusions can you draw about solution x?      ..   [3]  (j)  what conclusions can you draw about solution y?      ..   [2] [total: 20]",
            "7": "7 0620/52/o/n/15 \u00a9 ucles 2015blank page",
            "8": "8 0620/52/o/n/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxideproduced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitratewhite ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, thenadd aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxidethen aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify with dilute nitric acid, thenaqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess givinga colourless solutionwhite ppt., insoluble in excess ammonium (nh 4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excessgiving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess givinga colourless solutionwhite ppt., soluble in excess givinga colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_w15_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on page 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test october/november 2015  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 6 printed pages and 2 blank pages. [turn overib15 11_0620_53/2rp\u00a9 ucles 2015 *3872978216* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/53/o/n/15 \u00a9 ucles 20151  you are going to investigate the reaction between an acidic solution of iron( ii) sulfate, solution l,  and two different solutions of aqueous potassium manganate( vii), solutions m and n.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1   fill the burette with the solution m of potassium manganate( vii) to the 0.0 cm3 mark. using a  measuring cylinder pour 25 cm3 of solution l into the conical \ufb02 ask.   add 1 cm3 of the solution m to the \ufb02 ask, with swirling. continue to add solution m to the \ufb02 ask  until the mixture just turns permanently pink. record the burette readings in the table and  complete the table.   pour away the contents of the conical \ufb02 ask and rinse the \ufb02 ask with distilled water. \ufb01 nal burette reading / cm3 initial burette reading / cm3 difference / cm3 [3]  (b)  experiment 2   empty the burette and rinse thoroughly with distilled water. add a small volume of the solution n of aqueous potassium manganate( vii) to the burette and swirl. discard this solution.   now \ufb01 ll the burette with the solution n of potassium manganate( vii) to the 0.0 cm3 mark.   repeat experiment 1 using solution n instead of solution m.   record the burette readings in the table and complete the table. \ufb01 nal burette reading / cm3 initial burette reading / cm3 difference / cm3 [3]  (c)  why is the burette washed with  (i)  distilled water,   .   (ii)  solution n, before starting experiment 2?   .  [2]",
            "3": "3 0620/53/o/n/15 \u00a9 ucles 2015 [turn over (d) (i)   what colour change was observed in the \ufb02 ask during the addition of potassium  manganate( vii) solution to solution l in both experiments?  from .  to  .. .  [1]  (ii)  explain why an indicator is not needed.   . ..  [1]  (e) (i)   in which experiment was the greatest volume of potassium manganate( vii) solution  used?   . ..  [1]  (ii)  compare the volumes of potassium manganate( vii) solution used in experiments 1 and 2.   . ..  [1]  (iii)  suggest an explanation for the difference in volumes.   .    .    . ..  [2]  (f)  if experiment 2 was repeated using 12.5 cm3 of solution l, what volume of potassium  manganate( vii) solution would be used? explain your answer.   ... .   ... .   ... ...  [2]  (g)  give one advantage and one disadvantage of using a measuring cylinder for solution l.  advantage  ... ...  disadvantage   . [2] [total: 18]",
            "4": "4 0620/53/o/n/15 \u00a9 ucles 20152  you are provided with two solids, p and q.   carry out the following tests on the solids, recording all of your observations in the tables.   conclusions must not be written in the tables. tests observations tests on solid p (a)  describe the appearance of solid p.  .. (b)  use a spatula to place a little of solid p in  to a dry test-tube. heat the solid gently. ..   [2] add about 10 cm3 of distilled water to the rest of  solid p and shake to dissolve. divide the solution into four equal portions in test-tubes. carry out the following tests. (c)  test the ph of the \ufb01 rst portion of the  solution.   [1] (d)  use a thermometer to measure the  temperature of the second portion of solution p and record the temperature.   now add a spatula measure of sodium  hydrogen carbonate to the solution and stir with the thermometer.    measure and record the temperature of the  mixture after one minute.initial temperature =  ... \u00b0c \ufb01 nal temperature =   \u00b0c other observations =  .. ..  [3] (e)  pour the third portion of the solution into  a boiling tube. add a spatula measure  of copper( ii) oxide. heat the mixture to  boiling. leave the mixture to stand for one minute. ..   [1] (f)  to the fourth portion of the solution add  a small measure of magnesium powder. shake the mixture and test the gas evolved. ..   [3]",
            "5": "5 0620/53/o/n/15 \u00a9 ucles 2015 [turn overtests observations tests on solid q (g)  describe the appearance of solid q.   [1] (h)  add about 5 cm3 of distilled water into a  test-tube. measure and record the initial temperature of the water.   now add all of solid q to the water and stir  with the thermometer. measure and record the temperature of the mixture after one minute.   describe the mixture.initial temperature =  ... \u00b0c \ufb01 nal temperature =   \u00b0c  ..  [3] decant the solution and divide into two equal  portions in test-tubes. (i)  to the \ufb01 rst portion of the solution add  an equal volume of aqueous sodium hydroxide.   [2] (j)  to the second portion of the solution add  drops of aqueous ammonia with shaking.   now add excess aqueous ammonia. ..  ..  [3]  (k)  what conclusions can you draw about solid p?   ... .   ... ...  [2]  (l)  what conclusion can you draw about solid q?   ... ...  [1] [total: 22]",
            "6": "6 0620/53/o/n/15 \u00a9 ucles 2015blank page",
            "7": "7 0620/53/o/n/15 \u00a9 ucles 2015blank page",
            "8": "8 0620/53/o/n/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify with dilute nitric acid, then aqueous barium nitratewhite ppt. test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+)white ppt., soluble in excess giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess giving a colourless solution test for gases gas test and test results ammonia (nh3) turns damp red litmus paper blue carbon dioxide (co2) turns limewater milky chlorine (c l 2) bleaches damp litmus paper hydrogen (h2) \u2018pops\u2019 with a lighted splint oxygen (o2) relights a glowing splint"
        },
        "0620_w15_qp_61.pdf": {
            "1": "this document consists of 12 printed pages and 4 blank pages. [turn overib15 11_0620_61/2rp \u00a9 ucles 2015 *7046780444* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical october/november 2015  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/61/o/n/15 \u00a9 ucles 20151  a piece of limestone was heated strongly for ten minutes. the solid was then left to cool.   cold water was added to the solid. the solid reacted with the water to form a solution, a. waterlimestone lime (calcium oxide)  (a)  complete the boxes to label the pieces of apparatus. [2]  (b) (i)   suggest what could be used to hang the piece of limestone from the stand over the heat.  explain your answer.   .    .    . ..  [2]  (ii)  in what position should the air hole of the bunsen burner be?   . ..  [1]  (c)  predict the effect of  (i)  solution a on ph indicator paper,   . ..  [1]  (ii)  carbon dioxide on solution a.   . ..  [1] [total: 7]",
            "3": "3 0620/61/o/n/15 \u00a9 ucles 2015 [turn over2  the alkanes are a homologous series of hydrocarbons which are used as fuels. their general  formula is cnh2n+2.   the energy released when equal amounts of the \ufb01 rst \ufb01 ve alkanes were burned was measured. the  results are shown plotted on the grid below. 123 value of n in general formula4564000 3000 2000 1000 500energy releasedin kj  / mol  (a)  draw a line of best \ufb01 t on the grid. [1]  (b)  suggest two reasons why not all of the points lie on the line of best \ufb01 t.  1  ... ..  2  ... .. [2]",
            "4": "4 0620/61/o/n/15 \u00a9 ucles 2015 (c)  use your graph  to work out the amount of energy released when the same amount of hexane,  c6h14, is burned. show clearly how you worked out your answer.   ... ...  [2]  (d)   a student predicted that the energy released by burning butane would be two times the energy   produced by burning ethane.   suggest why she made this prediction and compare the values obtained for these two alkanes.   ... .   ... .   ... .   ... .   ... ...  [3] [total: 8]",
            "5": "5 0620/61/o/n/15 \u00a9 ucles 2015 [turn over3  electricity was used to break down dilute sulfuric acid using the apparatus shown. dilute sulfuric acidinert metal electrodeshydrogen oxygen +\u2013 light bulb  (a)  what name is given to this process?   ... ...  [1]  (b)  give one observation which could be made during this experiment.   ... ...  [1]  (c)  suggest a suitable metal for the inert metal electrodes.   ... ...  [1]  (d)  give a test for oxygen gas.  test   .  result  ..  [2]  (e)  why does hydrogen form at the negative electrode?   ... ...  [1]  (f)  the experiment was repeated using concentrated hydrochloric acid.   explain why this experiment was carried out in a fume cupboard.   ... .   ... ...  [2] [total: 8]",
            "6": "6 0620/61/o/n/15 \u00a9 ucles 2015blank page",
            "7": "7 0620/61/o/n/15 \u00a9 ucles 2015 [turn over4  a student investigated the rate of reaction between magnesium ribbon and four different solutions  of dilute sulfuric acid, a, b, c and d. the sulfuric acid was in excess in all experiments.   four experiments were carried out.  (a) experiment 1   using a measuring cylinder, 30 cm3 of aqueous sulfuric acid a was poured into a beaker. the  stop clock was started and a 4 cm length of magnesium was added to the sulfuric acid in the beaker. the mixture was stirred constantly. the time taken for all of the magnesium to react and disappear was measured.   the beaker was rinsed out with distilled water.  (b) experiment 2   experiment 1 was repeated using the solution b of sulfuric acid.  (c) experiments 3 and 4   experiment 1 was repeated, using the solutions c and d of sulfuric acid.",
            "8": "8 0620/61/o/n/15 \u00a9 ucles 2015 (d)  use the stop clock diagrams to record the times in the table. experiment numberconcentration of sulfuric  acid in mol / dm3 stop clock diagramtime for magnesium to completely disappear in seconds 1 1.00 0 10 3015 1545 5seconds minutes 2 0.80 0 10 3015 1545 5 3 0.60 0 10 3015 1545 5 4 0.50 0 10 3015 1545 5 [4]",
            "9": "9 0620/61/o/n/15 \u00a9 ucles 2015 [turn over (e)   plot the results for experiments 1, 2, 3 and 4 on the grid and draw a smooth line graph. 0 0.2 0.4 0.6 concentration of sulfuric acid in mol  / dm30.8 1.0 1.2140 120100 80604020 0time in seconds [3]  (f) (i)   from your graph , deduce the concentration of the sulfuric acid if the time for the reaction  was 80 s.   show clearly on the graph  how you worked out your answer. .. mol / dm3  [2]  (ii)  from your graph , deduce how long the reaction would take if a solution of sulfuric acid of  concentration 1.2 mol / dm3 was used.   show clearly on the graph  how you worked out your answer. .. s  [2]",
            "10": "10 0620/61/o/n/15 \u00a9 ucles 2015 (g)  why was the same amount of magnesium used in experiments 1, 2, 3 and 4?   ... ...  [1]  (h)  another experiment was carried out.   a 4 cm length of magnesium ribbon was added to dilute sulfuric acid. the temperature of the  solution was measured before and after the reaction. the observations were recorded and the gas given off tested.   observations:   rapid effervescence and the tube felt hot. a lighted splint popped.  use the thermometer diagrams to record the temperatures. 50 45 4030 25 20before addition of magnesiumtemperature / \u00b0ctemperature / \u00b0cafter addition of magnesium [2]  (i) (i)  what type of chemical reaction occurred when magnesium reacted with sulfuric acid?   . ..  [1]  (ii)  identify the gas given off.   . ..  [1]  (iii)  suggest the effect on the temperature change if this experiment was repeated using 2 cm  of magnesium ribbon.   .    . ..  [2]  (j)  suggest a different method which could be used to investigate the rate of the reaction between magnesium and sulfuric acid. state the difference in the apparatus used and measurements to be taken.  apparatus  ...   measurements   ...   ... .   ... ...  [3] [total: 21]",
            "11": "11 0620/61/o/n/15 \u00a9 ucles 2015 [turn over5  two metal salt solutions, x and y, were analysed. solution x was iron( ii) chloride.   the tests on x and y, and some of the observations, are given in the following tables.   complete the observations in the table. tests observations tests on solution x (a)  appearance of solution x. ..   [1] the solution was divided into four equal  portions. (b)  dilute nitric acid and aqueous  silver nitrate were added to the \ufb01 rst  portion of solution. ..   [1] (c)  aqueous sodium hydroxide was added to the second portion of solution and the mixture shaken. ..   [2] (d)  excess aqueous ammonia was added to the third portion of solution. ..   [1] (e)  an oxidising agent was added to  the fourth portion of the solution.   aqueous sodium hydroxide was then added to the mixture. ..   [2]",
            "12": "12 0620/61/o/n/15 \u00a9 ucles 2015tests observations tests on solution y the solution was divided into three  equal portions. (f)  dilute hydrochloric acid was added  to the \ufb01 rst portion of the solution. white precipitate formed (g)  aqueous sodium hydroxide was added to the second portion of the solution and the mixture shaken.   aluminium powder was added to the mixture and it was warmed gently. the gas given off was tested with damp red litmus paper.effervescence pungent gas evolved, litmus paper turned blue (h)  aqueous potassium iodide was added to the third portion of the solution. pale yellow precipitate  (i)  what conclusions can you draw about solution y?   ... .   ... ...  [2] [total: 9]",
            "13": "13 0620/61/o/n/15 \u00a9 ucles 2015 [turn over6  toothbright toothbright contains fluoride   toothbright toothpaste contains three compounds, sodium \ufb02 uoride, calcium carbonate and water.   calcium carbonate is insoluble in water and sodium \ufb02 uoride is soluble in water.   plan an investigation to \ufb01 nd out the percentage of calcium carbonate present in this toothpaste.   you are provided with common laboratory apparatus.   ...    ...    ...    ...    ...    ...    ...    ... ..  [7] [total: 7]",
            "14": "14 0620/61/o/n/15 \u00a9 ucles 2015blank page",
            "15": "15 0620/61/o/n/15 \u00a9 ucles 2015blank page",
            "16": "16 0620/61/o/n/15 \u00a9 ucles 2015blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series.cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        },
        "0620_w15_qp_62.pdf": {
            "1": "this document consists of 12 printed pages. [turn overib15 11_0620_62/fp \u00a9 ucles 2015 *7362226526* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical october/november 2015  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/62/o/n/15 \u00a9 ucles 20151  the volume of hydrochloric acid that reacts with 25.0 cm3 of aqueous sodium hydroxide can be  found using the apparatus below. 25.0  cm3 of aqueous sodium hydroxide + indicatorhydrochloric acid  (a)  complete the boxes to identify the pieces of apparatus labelled. [2]  (b)  name a suitable indicator that could be used.   ... ...  [1]",
            "3": "3 0620/62/o/n/15 \u00a9 ucles 2015 [turn over (c)  a student did the experiment four times and the volume of hydrochloric acid added each time  was measured.   use the burette diagrams in the table to record the volumes of hydrochloric acid added. experiment burette diagramvolume of acid added / cm3 116 1718 2161718 3161718 4161718 [2]  (d) (i)   what type of chemical reaction occurs when hydrochloric acid reacts with sodium  hydroxide?   . ..  [1]  (ii)  how did the student know when all of the sodium hydroxide had reacted?   . ..  [1]",
            "4": "4 0620/62/o/n/15 \u00a9 ucles 2015 (e) (i)   which one of the results is anomalous?   . ..  [1]  (ii)  suggest what may have caused this result to be anomalous.   . ..  [1]  (iii)  use the other results to calculate the average amount of hydrochloric acid that reacted  with the sodium hydroxide solution.   .    . ..  [2]  (f)  which of the solutions was more concentrated? explain your answer.   ... .   ... ...  [2] [total: 13]",
            "5": "5 0620/62/o/n/15 \u00a9 ucles 2015 [turn over2  a mixture of three compounds, p, q and r, was separated using a piece of paper. solvent front baselinepr q  (a)  name this method of separation.   ... ...  [1]  (b)  what could have been used to apply the mixture onto the paper?   ... ...  [1]  (c)  suggest a possible solvent that could be used for this separation.   ... ...  [1]  (d)  suggest why compound q remained on the baseline.   ... .   ... ...  [1]  (e) rf values are used to identify compounds. rf = distance travelled by the solventdistance travelled by compound   use the diagram to work out the rf value of compound r.   ... .   ... ...  [2] [total: 6]",
            "6": "6 0620/62/o/n/15 \u00a9 ucles 20153  a teacher demonstrated the rate of reaction of dilute nitric acid with powdered calcium carbonate  at different temperatures.   50 cm3 of dilute nitric acid was heated to a known temperature and placed on a balance. cotton wool 50 cm3 of dilute nitric acid balancepowdered calcium carbonate   excess powdered calcium carbonate was added to the nitric acid and the mass of the beaker and  contents recorded. the time taken for the mass to decrease by 1 g was measured. the experiment was repeated at different temperatures.  (a)  using the thermometer diagrams, record the temperatures in the table. thermometer diagramtemperature of nitric acid / \u00b0ctime for mass to decrease by 1 g in seconds 30 25 20139 40 35 30102 50 45 4099 60 55 5060 75 70 6545 85 80 7538 [3]",
            "7": "7 0620/62/o/n/15 \u00a9 ucles 2015 [turn over (b)  plot the results on the grid and draw a smooth line graph. 0 10 20 30 40 temperature of acid  / \u00b0c50 60 70 80160 140120100 8060 40 20 0time /  s [3]  (c)  which point is inaccurate? explain why you chose this point.   ... .   ... ...  [2]  (d)  use your graph  to \ufb01 nd out the time of reaction at a temperature of 30 \u00b0c. show clearly on the  grid how you obtained your answer.   ... ...  [3]",
            "8": "8 0620/62/o/n/15 \u00a9 ucles 2015 (e) (i)   how does the rate of this reaction vary with the change in temperature?   . ..  [1]  (ii)  explain why.   .    .    . ..  [2]  (f) (i)   what would be the effect of repeating the experiments using lumps of calcium carbonate  instead of powdered calcium carbonate? explain your answer.   .    . ..  [2]  (ii)  sketch on the grid the curve you would expect.  [1]  (g)  explain why cotton wool was used in the neck of the conical \ufb02 ask.   ... .   ... ...  [2] [total: 19]",
            "9": "9 0620/62/o/n/15 \u00a9 ucles 2015 [turn over4  three jars of gas have lost their labels. the gases are known to be  \u2022 ethene,  \u2022 ammonia,  \u2022 oxygen.   complete the table to show the chemical tests that could be used to identify each of these gases. gas chemical test result of test ethene  ..  [2] ammonia  ..  [2] oxygen  ..  [2] [total: 6]",
            "10": "10 0620/62/o/n/15 \u00a9 ucles 20155  two aqueous solutions, k and l, were analysed. solution l was aqueous calcium iodide.   tests on the solutions and some of the observations are in the following tables.   complete the observations in the second table. tests observations tests on solution k (a)  colour of solution k. green / blue (b)  the solution was divided into four  equal portions.  (i)  aqueous sodium hydroxide  was added to the \ufb01 rst portion  drop by drop and shaken.    an excess of aqueous sodium  hydroxide was then added to the mixture.  (ii)  aqueous ammonia was added  to the second portion drop by drop and shaken.    an excess of aqueous  ammonia was then added to the mixture.  (iii)  dilute nitric acid and barium  nitrate solution were added to the third portion.  (iv)  dilute nitric acid and silver  nitrate solution were added to the fourth portion.pale blue precipitate the precipitate was insoluble blue precipitate the precipitate dissolved to form a deep blue solution no visible change white precipitate formed  (c)  identify solution k.   ... ...  [2]",
            "11": "11 0620/62/o/n/15 \u00a9 ucles 2015 [turn overtests observations tests on solution l (d)  colour of solution l. ..  [1] (e)  the solution was divided into three  equal portions.  (i)  aqueous sodium hydroxide  was added to the \ufb01 rst portion  of the solution drop by drop and shaken.    an excess of aqueous sodium  hydroxide was then added to the mixture.  (ii)  aqueous ammonia was added  to the second portion of the solution drop by drop and shaken.    an excess of aqueous  ammonia was then added to the mixture and shaken.  (iii)  dilute nitric acid and silver  nitrate solution were added to the third portion of the solution...  [2] ..  [1] ..  [1] ..  [1]..  [2] [total: 10]",
            "12": "12 0620/62/o/n/15 \u00a9 ucles 2015permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.6  you are provided with samples of three metals, tin, zinc and silver.   plan an investigation to show the order of reactivity of these three metals.   you are provided with common laboratory apparatus and dilute acids.   ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 6]"
        },
        "0620_w15_qp_63.pdf": {
            "1": "this document consists of 11 printed pages and 1 blank page. [turn overib15 11_0620_63/2rp \u00a9 ucles 2015 *7700325994* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical october/november 2015  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/63/o/n/15 \u00a9 ucles 20151  the diagrams show the stages in the preparation of zinc nitrate crystals from lumps of zinc  carbonate. dilute nitric acidzinc carbonate bubblesof gas unreactedzinccarbonatestage 2 stage 1 stage 3 stage 5 stage 4 stage 6heatzinc nitrate solutionzinc carbonate  (a)  complete the boxes to show the apparatus used. [2]  (b)  use the diagrams to write a list of instructions for the stages of this preparation.  (i)  stages 1, 2, 3 and 4   .    .    . ..  [3]  (ii)  stage 5   . ..  [1]  (iii)  stage 6   .    . ..  [2] [total: 8]",
            "3": "3 0620/63/o/n/15 \u00a9 ucles 2015 [turn over2  a steel spoon can be coated in chromium using electrolysis. the spoon has to be very clean and  free of grease. spoon aqueous electrolytechromium electrodepower supply  (a)  name this process of coating a metal object with another metal.   ... ...  [1]  (b)  suggest one advantage of putting a layer of chromium on the spoon.   ... ...  [1]  (c)  which electrode should be the spoon?   ... ...  [1]  (d)  suggest the name of a compound that could dissolve in water to form the electrolyte.   ... ...  [2]  (e)  why must the spoon be very clean and free of grease?   ... ...  [1]  (f)  suggest one mistake in the apparatus set up.   ... ...  [1] [total: 7]",
            "4": "4 0620/63/o/n/15 \u00a9 ucles 20153  a student investigated the temperature changes when dilute nitric acid reacted with aqueous  potassium hydroxide.   solution c was nitric acid and solution d was aqueous potassium hydroxide.   she mixed together different volumes of c and d in four experiments. the maximum temperature  reached was measured in each experiment.   the initial temperature of the solutions was 25 \u00b0c.  (a)  use the thermometer diagrams in the table to record the maximum temperatures. work out the  rise in temperature in each experiment. experimentvolume of c / cm3volume of d / cm3thermometer diagrammaximum temperature / \u00b0ctemperature rise / \u00b0c 14 0 1 035 3025 23 0 2 0403530 32 0 3 0353025 41 0 4 0353025 [3]  (b)  why was the total volume of solution always 50 cm3?   ... ...  [1]",
            "5": "5 0620/63/o/n/15 \u00a9 ucles 2015 [turn over (c)   plot the results on the grid and draw two intersecting straight line graphs. 12 10 86420 50 40 30 20 10 0 volume of c  / cm3 volume of d / cm3temperature rise  / \u00b0c 0 1 02 03 04 05 0 [3]  (d) (i)   from your graph , deduce the greatest temperature rise that could occur.   show this point clearly on the grid , with an arrow.   . . \u00b0c  [1]  (ii)  from your graph , deduce the volumes of c and d that would produce this temperature  rise.  c  .   d  .  [2]  (e)  the experiment was repeated using solutions of c and d that were twice as concentrated as  used in the original experiment. the initial temperature of the solutions was still 25 \u00b0c.   suggest the greatest temperature rise that could occur.   ... ...  [1] [total: 11]",
            "6": "6 0620/63/o/n/15 \u00a9 ucles 20154  a student investigated the reaction between an acidic solution of iron( ii) sulfate, solution l, and two  different solutions of aqueous potassium manganate( vii), solutions m and n.   three experiments were carried out.  (a)  experiment 1   excess aqueous sodium hydroxide was added to about 3 cm3 of solution l in a test-tube.   what observations would be expected in experiment 1?   ... ...  [2]  (b)  experiment 2   a burette was \ufb01 lled with the solution m of potassium manganate( vii) to the 0.0 cm3 mark.  using a measuring cylinder, 25 cm3 of solution l was poured into a conical \ufb02 ask.   solution m was added to the \ufb02 ask until the mixture just turned permanently pink.   use the burette diagram to record the readings in the table and complete the table. 10 1112 final reading \ufb01 nal burette reading / cm3 initial burette reading / cm3 difference / cm3 [2]",
            "7": "7 0620/63/o/n/15 \u00a9 ucles 2015 [turn over (c)  experiment 3   the burette was emptied and rinsed thoroughly with distilled water. a small volume of the  solution n of aqueous potassium manganate( vii) was added to the burette and shaken.   this solution was discarded.   solution n of potassium manganate( vii) was then poured into the burette.   experiment 1 was repeated using solution n instead of solution m.   use the burette diagrams to record readings in the table and complete the table. 11 1213 final reading678 initial reading \ufb01 nal burette reading / cm3 initial burette reading / cm3 difference / cm3 [2]  (d)   why was the burette washed before starting experiment 3  (i)  with distilled water,   .   (ii)  then with solution n?   .  [2]  (e)  explain why an indicator was not needed.   ... ...  [1]",
            "8": "8 0620/63/o/n/15 \u00a9 ucles 2015 (f) (i)  in which experiment was the greater volume of potassium manganate( vii) solution used?   . ..  [1]  (ii)  compare the volumes of potassium manganate( vii) solution used in experiments 2 and 3.   . ..  [1]  (iii)  suggest an explanation for the difference in volumes.   .    .    . ..  [2]  (g)  if experiment 3 was repeated using 12.5 cm3 of solution l, what volume of potassium  manganate( vii) solution would be used? explain your answer.   ... .   ... ...  [2]  (h)  give one advantage and one disadvantage of using a measuring cylinder for solution l.  advantage  ... ...  disadvantage   . [2] [total: 17]",
            "9": "9 0620/63/o/n/15 \u00a9 ucles 2015 [turn over5  two solids, p and q, were analysed. q was anhydrous copper( ii) sulfate.   tests on the solids and some of the observations are in the following tables.   complete the observations in the table. tests observations tests on solid p (a)  appearance of solid p. white crystals (b)  solid p was heated gently in a dry  test-tube. condensation formed at the top of the test-tube tests on aqueous solution of p an aqueous solution of p was divided  into three equal portions.the following tests were carried out. (c)  the ph of the \ufb01 rst portion of the  solution was tested. ph 5 (d)  copper( ii) oxide was added to the  second portion of the solution. the mixture was boiled and the mixture left to stand for one minute. blue solution formed (e)  magnesium powder was added  to the third portion of the solution. the mixture was shaken and the gas evolved tested. effervescence, lighted splint popped  (f)  identify the gas in test (e).   ... ...  [1]  (g)  what conclusions can you draw about solid p?   ... .   ... ...  [2]",
            "10": "10 0620/63/o/n/15 \u00a9 ucles 2015tests observations tests on solid q (h)  appearance of solid q. ..  [1] (i)  solid q was added to distilled water  and stirred with a thermometer. the temperature of the mixture was measured and recorded after one minute.temperature change ... other observations .. ..  [2] the solution formed was divided into  two equal portions. (j)  an equal volume of aqueous  sodium hydroxide was added to the \ufb01 rst portion of the solution. ..  [2] (k)  drops of aqueous ammonia were  added to the second portion of the solution and shaken.   excess ammonia solution was then  added.  ..  [3] [total: 11]",
            "11": "11 0620/63/o/n/15 \u00a9 ucles 2015 [turn over6  dilute sulfuric acid reacts rapidly with magnesium ribbon. the magnesium ribbon gets smaller and  eventually disappears.   plan an investigation to show how the rate of this reaction changes using different concentrations  of sulfuric acid.   you are provided with common laboratory apparatus, sulfuric acid, water and magnesium ribbon.   ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 6]",
            "12": "12 0620/63/o/n/15 \u00a9 ucles 2015blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        }
    },
    "2016": {
        "0620_m16_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 14 printed pages and 2 blank pages.  ib16 03_0620_12/3rp  \u00a9 ucles arch [turn over       *0403093803* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice (core)  february/march 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2016 0620/12/f/m/16  1 two gas jars are set up as shown.    before afterjar 2jar 1 jar 2jar 1 lidair brown gas     the lid is removed and the gas jars are left to stand.  after some time the contents of both gas jars  are brown.    which process causes this to happen?  a condensation  b diffusion  c evaporation  d filtration     2 which piece of apparatus is used to measure variable quantities of liquid in a titration?    abcd      3 which method separates a mixture of sugar and glass?  a dissolve, filter and evaporate  b distil and filter  c fractionally distil  d use chromatography     ",
            "3": "3  \u00a9 ucles 2016 0620/12/f/m/16 [turn over  4 in which row are the substances correctly classified?     element compound mixture  a brass sulfur water  b sulfur brass water  c sulfur water brass  d water sulfur brass     5 element q has 4 electrons in its outer shell and has 69 neutrons. q conducts electricity.    what is q?  a carbon (c)  b lead (pb)  c thulium (tm)  d tin (sn)      6 which statement describes positive ions?  a positive ions have more electrons than neutrons.  b positive ions have more protons than neutrons.  c positive ions have more electrons than protons.  d positive ions have more protons than electrons.      7 the electronic structures of atoms x and y are shown.    x y     x and y form a covalent compound.   what is its formula?  a x 2 y b xy c xy 2 d xy 6      8 the compound magnesium nitrate has the formula mg(no 3)2.    what is the relative formula mass of magnesium nitrate?    a 86 b 134 c 148 d 172   ",
            "4": "4  \u00a9 ucles 2016 0620/12/f/m/16  9 the diagram shows, in cross-section, the arrangement of aluminium and steel wires in an electric  power cable.    key = aluminium = steel    which metal wire is the better conductor and which metal wire has the greater mechanical  strength?     better conductor greater  mechanical strength  a aluminium aluminium  b aluminium steel  c steel aluminium  d steel steel     10 when concentrated hydrochloric acid is electrolysed, gases p and q are formed.    pq + \u2013concentrated hydrochloric acid platinumelectrodes     what are p and q?   p q  a chlorine hydrogen  b chlorine oxygen  c hydrogen chlorine  d hydrogen oxygen     ",
            "5": "5  \u00a9 ucles 2016 0620/12/f/m/16 [turn over  11 which substance could not be used as a fuel to heat water in a boiler?  a ethanol  b hydrogen  c methane  d oxygen      12 which statement about reactions that produce heat is not correct?  a burning magnesium produces heat energy.  b the overall reaction is exothermic.  c the products have more energy than the reactants.  d the temperature of the surroundings increases.     13 which changes increase the rate of reaction?    1 increasing the concentration of the reactants  2 increasing the particle size of a solid reactant  3 increasing the temperature    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      14 two reactions involving water are shown.    x anhydrous cobalt( ii) chloride  +  water  \u2192  hydrated cobalt( ii) chloride  y iron  +  oxygen  +  water  \u2192  rust    which reactions are reversible by heating?     x y  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "6": "6  \u00a9 ucles 2016 0620/12/f/m/16  15 iron is extracted from iron oxide using carbon monoxide as shown.    iron oxide  +  carbon monoxide  \u2192  iron  +  carbon dioxide    which statement is correct?  a carbon monoxide is oxidised to carbon dioxide.  b carbon monoxide is reduced to carbon dioxide.  c iron is oxidised to iron oxide.  d iron oxide is oxidised to iron.      16 four different solutions, w, x, y and z, are tested with universal indicator.    solution w x y z  colour with  universal indicator green red purple orange    which solutions are acidic?  a w and z b x and z c x only d y only     17 methyl orange turns red in the solution formed when substance r reacts with water.    what is r?  a calcium oxide  b potassium oxide  c sodium oxide  d sulfur dioxide      18 a salt is made by adding an excess of an insoluble metal oxide to an acid.    how is the excess metal oxide removed from the mixture?  a chromatography  b crystallisation  c distillation  d filtration     ",
            "7": "7  \u00a9 ucles 2016 0620/12/f/m/16 [turn over  19 a substance is heated with aluminium foil in aqueous sodium hydroxide. a gas is produced which  turns damp, red litmus paper blue.    which anion is present in the substance?  a carbonate  b iodide  c nitrate  d sulfate     20 an element does not conduct electricity and exists as diatomic molecules.    where in the periodic table is the element found?    bac d       21 in the periodic table, how does the metallic character of the elements vary from left to right  across a period?  a it decreases.  b it increases.  c it increases then decreases.  d it stays the same.    22 the elements in a group of the periodic table show the following trends.    1 the element with the lowest proton number has the lowest reactivity.  2 all the elements in the group form basic oxides.  3 the density of the elements increases down the group.  4 the melting point of the elements decreases down the group.    in which group are the elements found?  a i b iv c vi d vii     ",
            "8": "8  \u00a9 ucles 2016 0620/12/f/m/16  23 which element is a transition metal?     melting point in  \u00b0c density in g  / cm3 colour of oxide  a 98 1.0 white  b 328 11.3 yellow  c 651 1.7 white  d 1240 7.4 black      24 uranium is a radioactive element but it is also a typical metal.    what is not a property of uranium?  a it can be hammered into shape.  b it conducts heat.  c it is used as a source of energy.  d it forms covalent compounds.     25 which metal reacts with steam but not with cold water?  a calcium  b copper  c sodium  d zinc      26 iron is extracted from hematite in the blast furnace.    the hematite contains silicon( iv) oxide (sand) as an impurity.    what reacts with this impurity to remove it?  a calcium oxide  b carbon  c carbon dioxide  d slag     ",
            "9": "9  \u00a9 ucles 2016 0620/12/f/m/16 [turn over  27 the bodies of aircraft are often made using aluminium.    which two properties of aluminium make it suitable for this use?     property 1 property 2  a good conductor of electricity good conductor of heat  b good conductor of electricity strong  c good conductor of heat low density  d strong low density     28 the diagram shows how water is treated to make it suitable for drinking.    reservoirstage 1 stage 2 chlorinationstage 3 drinking waterstage 4     what happens in stage 2?  a condensation  b distillation  c evaporation  d filtration      29 pure air contains nitrogen, oxygen and small amounts of other gases. the noble gases have  been left out of the table.    which row shows the composition of dry, unpolluted air?     nitrogen  / % oxygen  / % other gases  a 21 78 small amount of carbon dioxide  b 21 78 small amount of carbon monoxide  c 78 21 small amount of carbon dioxide  d 78 21 small amount of carbon monoxide    30 which pollutant gas can be produced as a result of incomplete combustion of octane, c 8h18?  a carbon  b carbon dioxide  c carbon monoxide  d methane   ",
            "10": "10  \u00a9 ucles 2016 0620/12/f/m/16  31 fertilisers are used to provide three elements needed to increase the yield of crops.    which two compounds would provide all three of these elements?  a ammonium nitrate and calcium phosphate  b ammonium nitrate and potassium sulfate  c potassium nitrate and calcium phosphate  d potassium nitrate and potassium sulfate     32 which statement describes a disadvantage of sulfur dioxide?  a it can be used as a bleach in making wood pulp.  b it can be used to kill bacteria in food.  c it can be used to manufacture sulfuric acid.  d it can dissolve the limestone in statues.    33 why does a farmer put lime (calcium oxide) on the soil?  a to act as a fertiliser  b to kill pests  c to make the soil less acidic  d to make the soil less alkaline    ",
            "11": "11  \u00a9 ucles 2016 0620/12/f/m/16 [turn over  34 what is the name of fraction x?    kerosenexgasolinerefinery gasfractions diesel oil lubricating fraction petroleum bitumen    a alcohol  b fuel oil  c naphtha  d paraffin      35 which pair of molecules are hydrocarbons?  a ethane and ethanol  b ethane and ethene  c ethanoic acid and ethene  d ethanol and ethanoic acid      36 which bond is not present in the structure of ethanol, ch 3ch 2oh?  a c\u2013c b h\u2013h c h\u2013o d o\u2013c     ",
            "12": "12  \u00a9 ucles 2016 0620/12/f/m/16  37 which change on the diagram involves combustion?    some of the reaction products are not shown on the diagram.    sugar + yeast in waterethanolcarbon dioxide ethene poly(ethene)change achange b change cchange d      38 the structures of three molecules are shown.    co ohhch hch hchh h hchh ch hhchh ch ohch hh     which homologous series is not represented?  a alcohols  b alkanes  c alkenes  d carboxylic acids      39 information about four hydrocarbons is shown.  hydrocarbon number of carbon atoms   in the molecule reaction with  bromine water  w 1 no reaction  x 2 no reaction  y 3 decolourises it  z 4 decolourises it     which statement is correct?  a hydrocarbon w has the formula ch 4 and can be polymerised.  b hydrocarbon x has the formula c 2h4 and can be polymerised.  c hydrocarbon y has the formula c 3h6 and can be polymerised.  d hydrocarbon z has the formula c 4h10 and can be polymerised.    ",
            "13": "13  \u00a9 ucles 2016 0620/12/f/m/16  40 which structure represents a compound that dissolves in water to form an acidic solution?    a hh hchhc hhc h c hhhc hhc hhc hhc o hdb hh hch chhc hhhc hhc c oo h     ",
            "14": "14  \u00a9 ucles 2016 0620/12/f/m/16  blank page      ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is  produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/12/f/m/16  blank page      ",
            "16": "16  \u00a9 ucles 2016 0620/12/f/m/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m16_qp_22.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib16 03_0620_22/3rp  \u00a9 ucles 2016 [turn over       *6492011221* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2 multiple choice (extended)  february/march 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2016 0620/22/f/m/16  1 two gas jars are set up as shown.    before afterjar 2jar 1 jar 2jar 1 lidair brown gas     the lid is removed and the gas jars are left to stand.  after some time the contents of both gas jars  are brown.    which process causes this to happen?  a condensation  b diffusion  c evaporation  d filtration     2 which piece of apparatus is used to measure variable quantities of liquid in a titration?    abcd     ",
            "3": "3  \u00a9 ucles 2016 0620/22/f/m/16 [turn over  3 a sample of a green food colouring was se parated into its component colours using paper  chromatography.     the results obtained are shown.    baselineblue spotyellow spotsolvent front     what is the rf value of the blue spot?  a 0.45 b 0.90 c 1.10 d 2.20      4 in which row are the substances correctly classified?     element compound mixture  a brass sulfur water  b sulfur brass water  c sulfur water brass  d water sulfur brass    5 which molecule contains only single covalent bonds?  a cl  2 b co 2 c n2 d o2    ",
            "4": "4  \u00a9 ucles 2016 0620/22/f/m/16  6 which structure represents the sodium chloride lattice?    na\u2013cl + na\u2013cl +na\u2013cl +na\u2013cl + na\u2013cl + na\u2013cl +na\u2013cl +na\u2013cl +a + \u2013 + \u2013 + \u2013+ \u2013 + \u2013 + \u2013 + \u2013+ \u2013b \u2013 + \u2013 + \u2013 +\u2013 + \u2013 + \u2013 + \u2013 +\u2013 +c + + + + + + + + + + +++ ++ +\u2013d \u2013 \u2013 \u2013 \u2013 \u2013 \u2013\u2013\u2013 \u2013\u2013\u2013\u2013\u2013 \u2013\u2013 \u2013 \u2013 \u2013 \u2013 \u2013 \u2013\u2013\u2013 \u2013      7 x and y are isotopes of the same element.    which statement is correct?  a x and y have atoms with different numbers of electron shells.  b x and y have atoms with the same nucleon number.  c x and y have atoms with the same number of outer shell electrons.  d x and y have different chemical properties.      8 which quantities of chemicals will react exactly with no reactants left over?  a 12  g of carbon and 12  g of oxygen  b 12 g of carbon and 48  g of oxygen  c 12 g of magnesium and 16  g of oxygen  d 24 g of magnesium and 16  g of oxygen   ",
            "5": "5  \u00a9 ucles 2016 0620/22/f/m/16 [turn over  9 magnesium nitride is formed when magnesium burns in air. magnesium nitride is an ionic  compound.    what is the formula of magnesium nitride?  a mgn 2 b mg 2n2 c mg 2n3 d mg 3n2     10 the electrolysis of concentrated hydrochloric acid is shown.    chlorine hydrogen concentrated hydrochloric acid \u2013 +platinumelectrodes     which statement describes what happens to the electrons during the electrolysis?  a they are added to chloride ions.  b they are added to hydrogen ions.  c they move through the circuit from positive to negative.  d they move through the solution from negative to positive.     11 which reaction does not occur in the extraction of aluminium?  a a l  3+  +  3e\u2013  \u2192  a l  b 2a l 2o3  +  3c  \u2192  4a l  +  3co 2  c 2o2\u2013  \u2192  o 2  +  4e\u2013  d c  +  o 2  \u2192  co 2     12 which substance could not be used as a fuel to heat water in a boiler?  a ethanol  b hydrogen  c methane  d oxygen     ",
            "6": "6  \u00a9 ucles 2016 0620/22/f/m/16  13 which row describes an endothermic reaction?     energy needed to  break bonds  / kj energy released by  forming bonds  / kj temperature  a 400 200 decreases  b 400 800 decreases  c 600 200 increases  d 600 800 increases     14 a reversible reaction is shown.     2no 2(g)    n2o4(g) \u2206 h = \u201358  kj / mol    which statement about an equilibrium mixture of no 2 and n 2o4 is correct?  a if the pressure is decreased the amount of n 2o4 increases.  b if the temperature is increased the amount of n 2o4 increases.  c the rates of formation and decomposition of n 2o4 are not the same.  d the decomposition of n 2o4 is an endothermic reaction.     15 which statement about catalysts in chemical reactions is not correct?  a catalysts are not used up in the reaction.  b catalysts increase the energy of the reacting particles.  c catalysts increase the rate of the reaction.  d catalysts lower the activation energy.    16 zinc is extracted from zinc blende by roasting it in air to form zinc oxide.    the zinc oxide is then heated with carbon to form zinc.    the equations for the reactions are shown.    1 2zns  +  3o 2  \u2192  2zno  +  2so 2    2 zno  +  c  \u2192  zn  +  co    which statement about reactions 1 and 2 is not correct?  a in reaction 1 the oxidation state of sulfur increases and it is oxidised.  b in reaction 1 the oxidation state of zinc increases and it is oxidised.  c in reaction 2 the carbon acts as a reducing agent and it is oxidised.  d in reaction 2 the oxidation state of zinc decreases and it is reduced.   ",
            "7": "7  \u00a9 ucles 2016 0620/22/f/m/16 [turn over  17 the diagram shows an energy level diagram for a reaction.    ea energy     the diagram shows that the reaction is ..1.. .    increasing the temperature increases the rate of reaction. a reason for this is that the ..2... .    which words correctly complete gaps 1 and 2?     1 2  a endothermic activation energy decreases  b endothermic collision rate increases  c exothermic activation energy decreases  d exothermic collision rate increases     18 concentrated hydrochloric acid is a strong acid .    what is meant by the terms \u2018strong\u2019 and \u2018acid\u2019?     strong acid  a contains a low proportion of water accepts protons  b contains a low proportion of water donates protons  c fully ionised accepts protons  d fully ionised donates protons    19 which oxide is amphoteric?  a aluminium oxide  b calcium oxide  c carbon monoxide  d sodium oxide    ",
            "8": "8  \u00a9 ucles 2016 0620/22/f/m/16  20 a salt is made by adding an excess of an insoluble metal oxide to an acid.    how is the excess metal oxide removed from the mixture?  a chromatography  b crystallisation  c distillation  d filtration     21 a substance is heated with aluminium foil in aqueous sodium hydroxide. a gas is produced which turns damp, red litmus paper blue.    which anion is present in the substance?  a carbonate  b iodide  c nitrate  d sulfate     22 an element does not conduct electricity and exists as diatomic molecules.    where in the periodic table is the element found?    bac d     23 in the periodic table, how does the metallic character of the elements vary from left to right  across a period?  a it decreases.  b it increases.  c it increases then decreases.  d it stays the same.     ",
            "9": "9  \u00a9 ucles 2016 0620/22/f/m/16 [turn over  24 the elements in a group of the periodic table show the following trends.    1 the element with the lowest proton number has the lowest reactivity.  2 all the elements in the group form basic oxides.  3 the density of the elements increases down the group.  4 the melting point of the elements decreases down the group.    in which group are the elements found?  a i b iv c vi d vii      25 brass is an alloy of two metals.    which row gives a correct use for the two metals from which brass is made?     metal 1 metal 2  a used for electrical wiring used for galvanising steel  b used for galvanising steel used for making aircraft  c used for making aircraft used for making cutlery  d used for making cooking pans used for electrical wiring     26 iron is extracted from hematite in the blast furnace.    the hematite contains silicon( iv) oxide (sand) as an impurity.    what reacts with this impurity to remove it?  a calcium oxide  b carbon  c carbon dioxide  d slag     27 the reaction below is called the \u2018thermite reaction\u2019.    2a l  +  fe 2o3  \u2192  2fe  +  a l 2o3      which pair of substances reacts in a similar way?  a fe and mgo  b fe and zno  c mg and cuo  d zn and a l 2o3     ",
            "10": "10  \u00a9 ucles 2016 0620/22/f/m/16  28 one method of preventing the rusting of iron is to keep oxygen away from the surface of the  metal.    which way of rust prevention does not use this method?  a coating the iron with grease  b connecting the iron to a more reactive metal  c covering the iron with plastic  d painting the iron     29 the diagram shows how water is treated to make it suitable for drinking.    reservoirstage 1 stage 2 chlorinationstage 3 drinking waterstage 4     what happens in stage 2?  a condensation  b distillation  c evaporation  d filtration      30 nitrogen monoxide is produced in a car engine when petrol is burnt.    the gases from the car engine are passed through a catalytic converter.    in the catalytic converter the nitrogen monoxide reacts with carbon monoxide to form nitrogen and carbon dioxide.    which statement is not correct?  a carbon monoxide is oxidised in the catalytic converter.  b carbon monoxide is produced by the complete combustion of petrol.  c nitrogen monoxide is formed by the reaction of nitrogen and oxygen.  d nitrogen monoxide is reduced in the catalytic converter.     31 which pollutant gas can be produced as a result of incomplete combustion of octane, c 8h18?  a carbon  b carbon dioxide  c carbon monoxide  d methane ",
            "11": "11  \u00a9 ucles 2016 0620/22/f/m/16 [turn over  32 fertilisers are used to provide three elements needed to increase the yield of crops.    which two compounds would provide all three of these elements?  a ammonium nitrate and calcium phosphate  b ammonium nitrate and potassium sulfate  c potassium nitrate and calcium phosphate  d potassium nitrate and potassium sulfate     33 what is a property of concentrated sulfuric acid but not of dilute sulfuric acid?  a it is a dehydrating agent.  b it neutralises alkalis.  c it produces a white precipitate with barium nitrate.  d it reacts with metals to give a salt and hydrogen.    34 why does a farmer put lime (calcium oxide) on the soil?  a to act as a fertiliser  b to kill pests  c to make the soil less acidic  d to make the soil less alkaline    ",
            "12": "12  \u00a9 ucles 2016 0620/22/f/m/16  35 what is the name of fraction x?    kerosenexgasolinerefinery gasfractions diesel oil lubricating fraction petroleum bitumen    a alcohol  b fuel oil  c naphtha  d paraffin      36 which compounds are alkanes?    compound w x y z  formula c 4h10 c 5h10 c 6h12 c 6h14    a w and x b w and z c x and y d y and z     ",
            "13": "13  \u00a9 ucles 2016 0620/22/f/m/16 [turn over  37 the statements below are about the alcohol homologous series.    the alcohols have the same ..1.. formula.    the alcohols have ..2.. chemical properties bec ause they have the same ..3.. .    the melting points of the alcohols ..4.. as the number of carbon atoms increases.    which words correctly complete gaps 1\u20134?     1 2 3 4  a general different functional group decrease  b general similar electronic structure increase  c general similar functional group increase  d molecular similar functional group increase      38 which structure represents a compound that dissolves in water to form an acidic solution?    a hh hchhc hhc h c hhhc hhc hhc hhc o hdb hh hch chhc hhhc hhc c oo h     ",
            "14": "14  \u00a9 ucles 2016 0620/22/f/m/16  39 the partial structure of an addition polymer is shown.    ch hccl clcl hch hch ch hc h    what is the structure of the monomer used to make this polymer?    ch ccl clhc hccl cl ch hha ch ch hccl ch hh ccl h hbc d      40 which statement about polymers is correct?  a addition polymers are all biodegradable.  b condensation polymers can all be hydrolysed to give amino acids.  c condensation polymers only exist in nature.  d forming addition polymers produces only one product.    ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/22/f/m/16  blank page     ",
            "16": "16  \u00a9 ucles 2016 0620/22/f/m/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m16_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/32   paper 3 theory (core) february/march 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib16 03_0620_32/6rp\u00a9 ucles 2016 *1609274387* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/f/m/16 \u00a9 ucles 20161  the diagram shows part of the periodic table. i li ti cr fe cuznc n o f ne ar kr xebr isi ge sn pbal clii iiiivv vi viiviii   answer the following questions using only the elements in the diagram.   each element may be used once, more than once or not at all.  (a)  which element  (i)  forms 78% of the air,   ...   [1]  (ii)  has an oxide which is a product of respiration,   ...   [1]  (iii)  is used to make food containers because of its resistance to corrosion,   ...   [1]  (iv)  forms an ion of type x3+,   ...   [1]  (v)  forms an ion whose aqueous solution forms a light blue precipitate on addition of a few  drops of aqueous ammonia?   ...   [1]",
            "3": "3 0620/32/f/m/16 \u00a9 ucles 2016 [turn over (b)  calcium is an element with several naturally-occurring isotopes.  (i)  what is the meaning of the term element ?   ...   [1]  (ii)  two of the isotopes of calcium are ca43 20  and ca48 20 .   complete the table to show the number of protons, neutrons and electrons in one atom of  each of these isotopes. ca43 20 ca48 20 number of protons number of neutronsnumber of electrons [3]  (iii)  determine the number of electrons in one calcium ion, ca 2+.   ...   [1] [total: 10]",
            "4": "4 0620/32/f/m/16 \u00a9 ucles 20162  molten potassium bromide can be electrolysed using the apparatus shown. + \u2013 graphite electrodes molten potassium bromid e  (a)  predict the products of this electrolysis at the  positive electrode (anode),    negative electrode (cathode).   [2]  (b) (i)  explain why graphite electrodes are used in this electrolysis.   ...   [1]  (ii)  give one other use of graphite.   ...   [1]  (c)  when chlorine is bubbled through an aqueous solution of potassium bromide, the solution turns red-brown in colour.   which substance causes the red-brown colour?   ..   [1]  (d)  describe what you would observe when an aqueous solution of potassium bromide is added  to an acidified aqueous solution of silver nitrate.   ..   [1]  (e)  silver nitrate decomposes when heated. one of the products is nitrogen dioxide.   state one adverse effect of nitrogen dioxide on health.   ..   [1] [total: 7]",
            "5": "5 0620/32/f/m/16 \u00a9 ucles 2016 [turn over3  many metals react with either cold water or steam.  (a)  describe the reaction of sodium with cold water, and iron with steam.   in your answer describe  \u2022 the products formed,  \u2022 any observations that can be made.               ..   [4]  (b)  iron reacts with hydrochloric acid. fe(s)  +  2hcl (aq)  \u2192  fecl 2(aq)  +  h2(g)   describe a practical method to investigate the rate of this reaction.   you may draw a labelled diagram.         ..   [3]  (c)  the experiment in (b) was repeated using different sized pieces of iron.   all other conditions remained the same.   the sizes of the pieces of iron were  \u2022 large pieces,  \u2022 small pieces,  \u2022 iron powder.   complete the table below by writing the sizes of the pieces in the first column. sizes of the pieces of ironrate of reaction in cm3 hydrogen / min 25 3 10 [1]",
            "6": "6 0620/32/f/m/16 \u00a9 ucles 2016 (d)  the graph shows the effect of temperature on the rate of the reaction of hydrochloric acid with  iron. 25 20 15 10 5 0 0 10 20 30 40 temperature  / \u00b0c50 60 70rate of reaction in cm3 hydrogen / min  (i)  describe the effect of temperature on the rate of this reaction.   .   ...   [2]  (ii)  determine the rate of reaction at 60 \u00b0c. . cm3 hydrogen / min  [1]  (e)  describe how the concentration of hydrochloric acid affects the rate of its reaction with iron.      ..   [1] [total: 12]",
            "7": "7 0620/32/f/m/16 \u00a9 ucles 2016 [turn over4  the structures of sodium chloride and nitrogen are shown below. na+cl \u2013na+ na+cl \u2013cl \u2013na+ na+cl \u2013cl \u2013na+cl \u2013 na+cl \u2013na+cl \u2013 sodium chloride nitrogennn nnnn n n  (a)  describe the structure and bonding of these two substances and the differences in  \u2022  their volatility,  \u2022  their electrical conductivity.                  ..   [5]  (b)  ammonia is manufactured by reacting nitrogen with hydrogen using a catalyst.  (i)  what is the purpose of the catalyst?   ...   [1]  (ii)  complete the chemical equation for this reaction.  n2  +  .h2  \u2192  .nh3 [2]  (iii)  complete the electronic structure of a molecule of ammonia.   show only the outer electrons. n h hh [2]",
            "8": "8 0620/32/f/m/16 \u00a9 ucles 2016 (iv)  ammonia reacts with copper( ii) oxide. 2nh3  +  3cuo  \u2192  3cu  +  3h2o  +  n2   which compound is reduced in this reaction?   explain your answer.   .   ...   [2] [total: 12]",
            "9": "9 0620/32/f/m/16 \u00a9 ucles 2016 [turn over5 (a)  the table shows some properties of cobalt, copper, magnesium and tin. metalrelative heat conductiondensity in g / cm3melting point / \u00b0crelative strength cobalt 1.00 8.90 1495 55.0 copper 3.85 8.92 1083 32.0 magnesium 1.50 1.74 649 1.5 tin 0.64 7.28 232 1.0   answer the questions using the information shown in the table.  (i)  which metal is the best to use for the base of a pan for cooking food?   use information in the table to give reasons for your answer.   .   ...   [2]  (ii)  which two metals in the table are transition elements?   use information in the table to give reasons for your answer.   .   ...   [2]  (iii)  which metal in the table is most likely to be used in an alloy for aircraft bodies?   use information in the table to give reasons for your answer.   .   ...   [2]  (b)  some observations about the reactions of the four metals with hydrochloric acid are shown in  the table. metal observations cobalt bubbles formed very slowly. copper no bubbles formed. magnesium many bubbles formed very rapidly. tin a steady stream of bubbles formed.   use the information in the table to put these metals in order of their reactivity with hydrochloric acid. least reactive most reactive [2]",
            "10": "10 0620/32/f/m/16 \u00a9 ucles 2016 (c)  crystals of hydrated cobalt( ii) sulfate, coso4.7h2o, can be made by reacting dilute  sulfuric acid with insoluble cobalt carbonate.   describe how you could prepare a pure dry sample of cobalt( ii) sulfate crystals from dilute  sulfuric acid and cobalt( ii) carbonate.               ..   [4]  (d)  when heated, hydrated cobalt( ii) sulfate forms an anhydrous salt in a reversible reaction.  (i)  complete the equation for this reaction by inserting the sign for a reversible reaction in the  box. coso4.7h2o hydrated cobalt( ii) sulfate pale redcoso4 anhydrous cobalt( ii) sulfate dark blue+   7h2o [1]  (ii)  suggest how you could use this reaction to test for the presence of water.   .   ...   [2] [total: 15]",
            "11": "11 0620/32/f/m/16 \u00a9 ucles 2016 [turn over6  citric acid is found in lemon juice. citric acid shows typical acidic properties.  (a)  describe how you could determine the ph of a solution of lemon juice using universal indicator.         ..   [2]  (b)  the structure of citric acid is shown below. c c c c hh c o o ho o o oh hh h o c h  (i)  on the diagram, draw a ring around a carboxylic acid functional group. [1]  (ii)  state the name of one other carboxylic acid.   ...   [1]  (c)  calcium citrate can be prepared by neutralising aqueous citric acid with excess calcium  carbonate.  (i)  complete the word equation for this reaction. citric acid+calcium carbonate\u2192calcium citrate+ + [2]  (ii)  suggest how you could separate the excess calcium carbonate from the rest of the solution.   ...   [1]",
            "12": "12 0620/32/f/m/16 \u00a9 ucles 2016 (d)  the energy level diagram for the reaction of citric acid with sodium hydrogen carbonate is  shown below. energy reactantsproducts   is this reaction exothermic or endothermic?   give a reason for your answer.      ..   [1]  (e)  both citric acid and ethanol can be manufactured by fermentation.  (i)  complete the chemical equation for the fermentation of glucose to form ethanol.  c6h12o6  \u2192  .c2h5oh  +  .co2 [2]  (ii)  state two conditions needed for fermentation.   .   ...   [2]  (iii)  complete the table below and calculate the relative molecular mass of glucose. type of atom number of atoms relative atomic mass carbon 6 12 6 \u00d7 12 = 72 hydrogen oxygen relative molecular mass =   [2] [total: 14]",
            "13": "13 0620/32/f/m/16 \u00a9 ucles 2016 [turn over7  rhenium is a metal.  (a)  describe three physical properties of rhenium.         ..   [3]  (b)  the structure of a rhenium chloride molecule is shown. cl clcl clre re re clclcl clcl   determine the simplest formula for this chloride of rhenium.   ..   [1]  (c)  rhenium oxide is a yellow solid which undergoes sublimation at a low temperature.   what is the meaning of the term sublimation ?   ..   [1]  (d)  rhenium oxide reacts with water to form perrhenic acid.   perrhenic acid is strongly acidic.  (i)  which one of the following ph values represents an acidic solution?   draw a ring around the correct answer. ph 2          ph 7          ph 9          ph 14 [1]",
            "14": "14 0620/32/f/m/16 \u00a9 ucles 2016 (ii)  perrhenic acid reacts with potassium hydroxide.   complete the word equation for this reaction. perrhenic acid+potassium hydroxide\u2192potassium perrhenate+ [1]  (iii)  which one of the following compounds will react with perrhenic acid?   tick one box.  ethane  hydrochloric acid  potassium carbonate  sodium chloride [1]  (e)  potassium perrhenate has a similar formula to potassium manganate( vii).   potassium manganate( vii) decomposes to give off oxygen.   describe a test for oxygen.  test  .  result  .. [2] [total: 10]",
            "15": "15 0620/32/f/m/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "16": "16 0620/32/f/m/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi v ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silico n 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn coperniciu m \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arseni c 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorin e 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samariu m 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrencium \u2013"
        },
        "0620_m16_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/42   paper 4 theory (extended) february/march 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib15 03_0620_42/7rp\u00a9 ucles 2016 *9003309678* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/f/m/16 \u00a9 ucles 20161 (a)  the table below gives information about particles.   complete the table. the first line has been done for you. particlenumber of protonsnumber of electronselectronic configurationcharge on particle a 12 10 2,8 2+ b 18 2,8,8 1\u2013 c 18 2,8,8 0 d 8 10 [4]  (b)  gallium is a group iii element.   define the term element .         ..   [1]  (c)  the following are gallium atoms. ga69 31             ga71 31   complete the following table. atomnumber of protonsnumber of neutronsnumber of electrons ga6931 ga71 31 [3] [total: 8]",
            "3": "3 0620/42/f/m/16 \u00a9 ucles 2016 [turn over2  rubidium, rb, is a group i element. it has similar physical and chemical properties to the other  elements in group i.  (a)  predict how many electrons there are in the outer shell of a rubidium atom.   ..   [1]  (b)  predict one physical property of rubidium which is the same as that of a transition element  such as iron.   ..   [1]  (c)  predict two physical properties of rubidium which are different to those of a transition element  such as iron.      ..   [2]  (d)  when rubidium is added to cold water a reaction occurs.  (i)  suggest two observations that would be made when rubidium is added to cold water.   .   ...   [2]  (ii)  what would be the colour of the solution if methyl orange was added to it after the reaction?   ...   [1]  (iii)  write a chemical equation for the reaction between rubidium and water.   ...   [2]  (iv)  put the group i elements, caesium, lithium, potassium, rubidium and sodium in their order  of reactivity with water. put the most reactive element first. most reactive least reactive [1]  (v)  suggest one safety measure that should be used when rubidium is added to cold water.   ...   [1]  (e)  the phosphate ion has the formula po43\u2013.  deduce the formula of rubidium phosphate.   ..   [1] [total: 12]",
            "4": "4 0620/42/f/m/16 \u00a9 ucles 20163  carbon dioxide and silicon( iv) oxide are oxides of group iv elements.  (a)  complete the following table. carbon dioxide silicon( iv) oxide formula sio2 melting point / \u00b0c \u201356 1610 physical state at 25 \u00b0c gas conduction of electricity non-conductor structure macromolecular [4]  (b) (i) name the type of bonds that exist between the atoms in silicon( iv) oxide.   ...   [1]  (ii)  explain why silicon( iv) oxide has a very high melting point.   .   ...   [1]  (iii)  explain, in terms of attractive forces between particles, why carbon dioxide has a very low  melting point.   .   ...   [1]  (iv)  explain, in terms of particles, why carbon dioxide is a non-conductor of electricity.   .   ...   [1]  (c)  suggest a chemical equation for the reaction between sodium hydroxide solution and carbon dioxide.   ..   [2]",
            "5": "5 0620/42/f/m/16 \u00a9 ucles 2016 [turn over (d) (i)  name the type of chemical reaction in which carbon dioxide is produced from fossil fuels.   ...   [1]  (ii)  name the chemical process in which green plants convert carbon dioxide into carbohydrates.   ...   [1]  (iii)  name the chemical process in which living things produce carbon dioxide.   ...   [1] [total: 13]",
            "6": "6 0620/42/f/m/16 \u00a9 ucles 20164  hydrogen peroxide, h2o2, decomposes into water and oxygen in the presence of a catalyst,  manganese( iv) oxide. 2h2o2(aq)  \u2192  2h2o(l)  +  o2(g)  (a)  what is meant by the term catalyst?      ..   [2]  (b)  a student studies the rate of decomposition of hydrogen peroxide using the apparatus shown.  the student uses 20 cm3 of 0.1 mol / dm3 hydrogen peroxide and 1.0 g of manganese( iv) oxide.    the student measures the volume of oxygen given off at regular time intervals until the reaction  stops. a graph of the results is shown. hydrogen peroxidecatalystgas syringe volume of oxygenproduced  / cm3 time  / s00  (i)  when is the rate of reaction highest?   ...   [1]  (ii)  suggest one method of increasing the rate of reaction using the same amounts of hydrogen  peroxide and manganese( iv) oxide.   ...   [1]",
            "7": "7 0620/42/f/m/16 \u00a9 ucles 2016 [turn over (c) (i)  calculate the number of moles of hydrogen peroxide used in this experiment. . mol  [1]  (ii)  use your answer to (c)(i) and the equation to calculate the number of moles of oxygen  produced in the reaction. 2h2o2(aq)  \u2192  2h2o(l)  +  o2(g) . mol  [1]  (iii)  calculate the volume (at r.t.p.) of oxygen produced. . dm3  [1]  (iv)  what would be the effect on the volume of oxygen produced if the mass of catalyst was  increased?   ...   [1]  (v)  deduce the volume of oxygen that would be produced if 20 cm3 of 0.2 mol / dm3 hydrogen  peroxide was used instead of 20 cm3 of 0.1 mol / dm3 hydrogen peroxide. . dm3  [1]",
            "8": "8 0620/42/f/m/16 \u00a9 ucles 2016 (d)  the student carries out a second experiment to investigate whether another substance,  copper( ii) oxide, is a better catalyst than manganese( iv) oxide.   describe how the second experiment is carried out. you should state clearly how you would  make sure that the catalyst is the only variable.                  ..   [3] [total: 12]",
            "9": "9 0620/42/f/m/16 \u00a9 ucles 2016 [turn over5  this question is about compounds of nitrogen.  (a) (i)  describe the haber process giving reaction conditions and a chemical equation.   reference to rate and yield is not required.   .   .   .   .   ...   [5]  (ii)  give one use of ammonia.   ...   [1]  (b)  the diagram shows the structure of a hydrazine molecule. n hh n hh   draw the electron arrangement of a hydrazine molecule. show the outer shell electrons only. [2]  (c)  hydrazine is a base.  (i)  define the term base.   ...   [1]  (ii)  complete the chemical equation to show that hydrazine acts as a base when added to  water.  n2h4  +  h2o  \u2192  ..  +  .. [1]",
            "10": "10 0620/42/f/m/16 \u00a9 ucles 2016 (d)  nitrogen dioxide is an atmospheric pollutant.  (i)  state one environmental problem caused by nitrogen dioxide.   ...   [1]  (ii)  explain how oxides of nitrogen, such as nitrogen dioxide, are formed in car engines.   .   ...   [2] [total: 13]",
            "11": "11 0620/42/f/m/16 \u00a9 ucles 2016 [turn over6  iron pyrite, fes2, is known as fool\u2019s gold because it is a shiny yellow solid which is similar in  appearance to gold. iron pyrite is an ionic compound. gold is a metallic element.  (a)  iron pyrite, fes2, contains positive and negative ions. the positive ion is fe2+.   deduce the formula of the negative ion.   ..   [1]  (b)  a student is provided with a sample of iron pyrite and a sample of gold.   suggest how the student could distinguish between the two substances.      ..   [2]  (c)  sulfur dioxide is produced on a large scale by heating iron pyrite strongly in air. the iron pyrite  reacts with oxygen in the air producing iron( iii) oxide, fe2o3, and sulfur dioxide.  (i)  construct a chemical equation for the reaction between iron pyrite and oxygen.   ...   [2]  (ii)  give one use of sulfur dioxide.   ...   [1] [total: 6]",
            "12": "12 0620/42/f/m/16 \u00a9 ucles 20167 (a)  alkanes and alkenes are examples of hydrocarbons.  (i)  what is meant by the term hydrocarbon ?   .   ...   [1]  (ii)  give the general formula of straight-chain  alkanes,  ..  alkenes.  .. [2]  (b)  a compound x contains carbon, hydrogen and oxygen only.   x contains 54.54% of carbon by mass, 9.09% of hydrogen by mass and 36.37% of oxygen by  mass.  (i)  calculate the empirical formula of compound x. [2]  (ii)  compound x has a relative molecular mass of 88.   deduce the molecular formula of compound x. [2]",
            "13": "13 0620/42/f/m/16 \u00a9 ucles 2016 [turn over (c)  an ester has the molecular formula c3h6o2.   name and give the structural formulae of two esters with the molecular formula c3h6o2. name of ester structural formula [4]  (d)  name the ester produced from the reaction of propanoic acid and methanol.   ..   [1]  (e)  a polyester is represented by the structure shown. co co o o  (i)  what type of polymerisation is used for the production of polyesters?   ...   [1]  (ii)  which simple molecule is removed when the polyester is formed?   ...   [1]  (iii)  complete the diagrams below to show the structures of the monomers used to produce  the polyester. show all atoms and bonds. c c o o [2] [total: 16]",
            "14": "14 0620/42/f/m/16 \u00a9 ucles 2016blank page",
            "15": "15 0620/42/f/m/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "16": "16 0620/42/f/m/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi v ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silico n 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn coperniciu m \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arseni c 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorin e 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samariu m 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrencium \u2013"
        },
        "0620_m16_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/52   paper 5 practical test february/march 2016  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructions cambridge international examinations cambridge international general certificate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib16 03_0620_52/5rp\u00a9 ucles 2016 *1793569024* for examiner\u2019s use total the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/52/f/m/16 \u00a9 ucles 20161  you are going to investigate the rate of a reaction between two solutions, j and k, and sulfuric acid  at different temperatures.   read all the instructions below carefully before starting the experiments.   instructions   you are going to carry out four experiments.  (a) experiment 1   use the large measuring cylinder to pour 50 cm3 of distilled water and 40 cm3 of sulfuric acid  into the 250 cm3 conical flask.   use the small measuring cylinder to add 2 cm3 of methyl orange and 5 cm3 of solution j to the  mixture in the conical flask. measure the temperature of the mixture and record it in the table.   use the small measuring cylinder to now start the reaction by adding 5 cm3 of solution k to the  conical flask and immediately start your timer and swirl the mixture.   measure the time taken for the mixture to turn very pale yellow and record the time in the table.  measure and record the final temperature of the mixture.   experiment 2   repeat experiment 1 but heat the mixture in the conical flask to about 30 \u00b0c before adding the  solution k. measure and record the temperature of the mixture.   now add 5 cm3 of solution k to the conical flask and immediately start your timer and swirl the  mixture.   measure the time taken for the mixture to turn very pale yellow and record the time in the table.    measure and record the final temperature of the mixture.   experiment 3   repeat experiment 1 but heat the mixture in the conical flask to about 40 \u00b0c before adding  the solution k to the conical flask. take the same measurements and record the values in the  table.   experiment 4   repeat experiment 1 but heat the mixture in the conical flask to about 50 \u00b0c before adding  the solution k to the conical flask. take the same measurements and record the values in the  table.   work out the average temperatures to complete the table. experimenttime taken for mixture to  turn very pale yellow / sinitial temperature / \u00b0cfinal  temperature / \u00b0caverage temperature / \u00b0c 1 2 34 [4]",
            "3": "3 0620/52/f/m/16 \u00a9 ucles 2016 [turn over (b)  plot the results you have obtained on the grid and draw a smooth line graph. 0 10 20 30 average temperature  / \u00b0ctime  / s 40 50 60 [4]  (c)  from your graph, deduce the time taken for the mixture to turn very pale yellow  if experiment 1  was repeated at an average temperature of 60 \u00b0c.   show clearly on the grid  how you worked out your answer.   ..   [2]",
            "4": "4 0620/52/f/m/16 \u00a9 ucles 2016 (d) (i)  in which experiment was the rate of reaction greatest?   ...   [1]  (ii)  explain why the rate of reaction was greatest in this experiment.   .   .   ...   [2]  (e) (i)  suggest and explain the effect on the results of using a burette to measure the volume of  solution j.   .   ...   [2]  (ii)  suggest and explain one other improvement to these experiments.   .   ...   [2] [total: 17]",
            "5": "5 0620/52/f/m/16 \u00a9 ucles 2016 [turn over2  you are provided with two solids, l and m, which are both salts.   carry out the following tests on the solids, recording all of your observations at each stage.  tests on solid l  (a)  describe the appearance of solid l.   ..   [1]  (b)  add about 10 cm3 of distilled water to solid l and shake the mixture for about one minute to  dissolve.   divide the solution into four equal portions in four test-tubes and carry out the following tests.  (i)  add several drops of aqueous ammonia to the first portion of the solution.   now add excess ammonia solution to the mixture and shake.  observation  .   .   .   ...   [4]  (ii)  add excess aqueous sodium hydroxide to the second portion of the solution.  observation  .   ...   [1]  (iii)  add about 1 cm3 of dilute nitric acid to the third portion of the solution followed by aqueous  silver nitrate.  observation  ...   [1]  (iv)  add about 1 cm3 of dilute nitric acid to the fourth portion of the solution followed by aqueous  barium nitrate.  observation  ...   [1]  (c)  identify solid l.      ..   [2]",
            "6": "6 0620/52/f/m/16 \u00a9 ucles 2016 tests on solid m  (d)  use a spatula to divide solid m into two portions in two test-tubes.  heat the first portion of the solid, gently.   test the gas given off with damp red litmus paper.  observation        ..   [3]  (e)  dissolve the second portion of the solid in about 6 cm3 of water. pour half of the solution into a  boiling tube.  (i)  add about 1 cm3 of aqueous sodium hydroxide to the solution in the boiling tube and heat  the mixture gently. test the gas given off.  observation  ...   [1]  (ii)  add about 1 cm3 of dilute nitric acid to the remaining solution in the test-tube followed by  aqueous silver nitrate.  observation  ...   [1]  (f)  identify solid m.      ..   [2] [total: 17]",
            "7": "7 0620/52/f/m/16 \u00a9 ucles 2016 [turn over3  the label on a bottle of orange drink stated \u2018contains no artificial colours\u2019. a scientist thought that  the orange colour in the drink was a mixture of two artificial colours:  \u2022 sunset yellow e110  \u2022 allura red e129   plan an investigation to show that the orange colour in the drink did not contain these two artificial  colours.   you are provided with samples of e110, e129 and the orange colouring from the drink. you are also provided with common laboratory apparatus.   you may draw a diagram to help answer the question.   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "8": "8 0620/52/f/m/16 \u00a9 ucles 2016blank page",
            "9": "9 0620/52/f/m/16 \u00a9 ucles 2016blank page",
            "10": "10 0620/52/f/m/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/52/f/m/16 \u00a9 ucles 2016notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/52/f/m/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. test for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidifed aqueous potassium  manganate( vii) from purple to  colourless"
        },
        "0620_m16_qp_62.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib16 03_0620_62/5rp \u00a9 ucles 2016 *8977051001* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/62   paper 6 alternative to practical february/march 2016  1 hour candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/f/m/16 \u00a9 ucles 20161  the diagrams show the apparatus used to obtain crystals of calcium chloride from a mixture of solid  calcium chloride and solid calcium carbonate.   calcium chloride is soluble in water and calcium carbonate is insoluble in water. a b cdish solid  (a)  complete the boxes to name the apparatus. [2]  (b) (i)  write down the order in which the apparatus should be used in this experiment.   ...   [1]  (ii)  name the separation process in c.   ...   [1]  (c) (i) what has been added to the mixture in b?   ...   [1]  (ii)  what is the general name given to the liquid in the dish in c?   ...   [1]  (d)  how would you know when to stop heating the dish in a?      ..   [1] [total: 7]",
            "3": "3 0620/62/f/m/16 \u00a9 ucles 2016 [turn over2  a teacher investigated the rate of a reaction between two solutions, j and k, and sulfuric acid at  different temperatures.   four experiments were carried out.  (a) experiment 1   a large measuring cylinder was used to pour 50 cm3 of distilled water and 40 cm3 of sulfuric acid  into a 250 cm3 conical flask.   a small measuring cylinder was used to add 2 cm3 of methyl orange and 5 cm3 of solution j to  the mixture in the conical flask. the temperature of the mixture was measured.   the reaction was started by adding 5 cm3 of solution k to the conical flask, immediately starting  the timer and swirling the mixture.   the time taken for the mixture to turn pale yellow was measured. the final temperature of the  mixture was measured.   experiment 2   experiment 1 was repeated but the mixture in the conical flask was heated to about 30 \u00b0c  before adding the solution k. the temperature of the mixture was measured.   5 cm3 of solution k was added to the conical flask. the timer was started and the mixture  swirled.   the time taken for the mixture to turn pale yellow was measured. the final temperature of the mixture was measured.   experiment 3   experiment 1 was repeated but the mixture in the conical flask was heated to about 40 \u00b0c  before adding the solution k to the flask. the same measurements were taken.   experiment 4   experiment 1 was repeated but the mixture in the conical flask was heated to about 50 \u00b0c  before adding the solution k to the flask. the same measurements were taken.   stop-clock diagrams for these experiments are on page 4.",
            "4": "4 0620/62/f/m/16 \u00a9 ucles 2016  use the stop-clock diagrams to record the times in the table.   work out the average temperatures to complete the table. 0 0 10 3015 1545 1 17 15 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5experimentstop-clock diagramtime taken for mixture to turn pale yellow / sinitial temperature / \u00b0cfinal temperature / \u00b0caverage temperature / \u00b0c 2 28 26 3 42 40 4 51 49second s minutes [4]",
            "5": "5 0620/62/f/m/16 \u00a9 ucles 2016 [turn over (b)  plot the results on the grid and draw a smooth line graph. 160 140 120 100 80 60 40 20 0 0 10 20 30 average temperature  / \u00b0c40 50 60time  / s   [4]  (c)  from your graph deduce the time taken for the mixture to turn pale yellow if experiment 1 was  repeated at an average temperature of 60 \u00b0c.   show clearly on the grid  how you worked out your answer.   ..   [2]",
            "6": "6 0620/62/f/m/16 \u00a9 ucles 2016 (d) (i)  in which experiment was the rate of reaction greatest?   ...   [1]  (ii)  explain why the rate of reaction was greatest in this experiment.   .   .   ...   [2]  (e) (i)  suggest and explain the effect on the results of using a burette to measure the volume of  solution j.   .   ...   [2]  (ii)  suggest and explain one other improvement to these experiments.   .   ...   [2] [total: 17]",
            "7": "7 0620/62/f/m/16 \u00a9 ucles 2016 [turn over3  two solids, l and m, were analysed. solid l was copper( ii) chloride and solid m was a different  salt.   the tests on the solids, and some of the observations, are shown.  tests on solid l  (a)  describe the appearance of solid l.  observation  ..   [1]  (b) distilled water was added to solid l and shaken to dissolve.   the solution was divided into four equal portions in four test-tubes and the following tests  carried out.  (i)  drops of aqueous ammonia were added to the first portion of the solution.   excess ammonia solution was then added to the mixture and shaken.  observation  .   .   .   ...   [4]  (ii)  excess aqueous sodium hydroxide was added to the second portion of the solution.  observation  .   ...   [1]  (iii)  dilute nitric acid was added to the third portion of the solution followed by aqueous silver  nitrate.  observation  ...   [1]  (iv)  dilute nitric acid was added to the fourth portion of the solution followed by aqueous barium nitrate.  observation  ...   [1]",
            "8": "8 0620/62/f/m/16 \u00a9 ucles 2016 tests on solid m   tests are carried out and the following observations made. tests on solid m observations appearance of the solid. white crystals the solid was heated and the gas given off was  tested with damp red litmus paper.a sublimate formed on the sides of the test-tube litmus paper turned blue solid m was dissolved in water to form a  solution. aqueous sodium hydroxide was added to the  solution and the mixture heated. the gas given  off was tested.pungent gas evolved ph paper showed ph 10 dilute nitric acid was added to the solution followed by aqueous silver nitrate. yellow precipitate  (c)  identify solid m.      ..   [2] [total: 10]",
            "9": "9 0620/62/f/m/16 \u00a9 ucles 2016 [turn over4  the label on a bottle of orange drink stated \u2018contains no artificial colours\u2019. a scientist thought that  the orange colour in the drink was a mixture of two artificial colours:  \u2022  sunset yellow e110  \u2022  allura red e129   plan an investigation to show that the orange colour in the drink did not contain these two artificial  colours.   you are provided with samples of e110, e129 and the orange colouring from the drink. you are also  provided with common laboratory apparatus.   you may draw a diagram to help answer the question.   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "10": "10 0620/62/f/m/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/62/f/m/16 \u00a9 ucles 2016blank page",
            "12": "12 0620/62/f/m/16 \u00a9 ucles 2016blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. "
        },
        "0620_s16_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern i reland as a cambridge international level1/level 2 certificate .  this document consists of 16 printed pages.  ib16 06_0620_11/4rp  \u00a9 ucles 2016 [turn over       *0022143872* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice (core)  may/june 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2016 0620/11/m/j/16  1 in which changes do the particles move further apart?     w x  gas      liquid      solid   y z    a w and x b w and z c x and y d y and z      2 a sample of a dye is investigated by chromatography.    a line is drawn across a piece of chromatography paper and a spot of the dye is placed on it.    the paper is placed in water.    waterchromatography paper line spot of dye     which row is correct?     what is used to   draw the line position of spot  a ink above the level of the water  b ink below the level of the water  c pencil above the level of the water  d pencil below the level of the water     3 one of the instructions for an experiment reads as follows.    quickly add 50  cm3 of acid.    what is the best piece of apparatus to use?  a a burette  b a conical flask  c a measuring cylinder  d a pipette     ",
            "3": "3  \u00a9 ucles 2016 0620/11/m/j/16 [turn over  4 diamond and graphite are macromolecules.    which statement about diamond and graphite is not correct?  a they are giant structures with high melting points.  b they are non-conductors of electricity.  c they contain only atoms of a non-metal.  d they have covalent bonds between the atoms.     5 the table shows the electronic structure of four atoms.    atom electronic structure  w 2,8,1  x 2,8,4  y 2,8,7  z 2,8,8    which two atoms combine to form a covalent compound?  a w and x b w and y c x and y d x and z    6 an aluminium atom has a nucleon number of 27 and a proton number of 13.    how many neutrons does this aluminium atom contain?  a 13 b 14 c 27 d 40      7 what happens when a bond is formed between a green gaseous element and a soft metallic element?  a the gas atoms gain an electron.  b the gas atoms lose an electron.  c the metal atoms gain an electron.  d the two elements share a pair of electrons.     8 the equation shows the reaction between magnesium and sulfuric acid.  [a r: h, 1; o, 16; mg, 24; s, 32]    mg  +  h 2so 4  \u2192  mgso 4  +  h 2    in this reaction, which mass of magnesium sulfate is formed when 6  g of magnesium react with  excess sulfuric acid?  a 8 b 24 c 30 d 60   ",
            "4": "4  \u00a9 ucles 2016 0620/11/m/j/16  9 the diagram shows an electrical cable.    metal coreplastic coating     which statement about the substances used is correct?  a the coating is plastic because it conducts electricity well.  b the core is copper because it conducts electricity well.  c the core is copper because it is cheap and strong.  d the core is iron because it is cheap and strong.     10 when substance x is electrolysed, the amount of gases p and q formed is shown.    pq + \u2013substance x     what is substance x?  a concentrated aqueous sodium chloride  b concentrated hydrochloric acid  c dilute sulfuric acid  d molten lead( ii) bromide     ",
            "5": "5  \u00a9 ucles 2016 0620/11/m/j/16 [turn over  11 the energy level diagram for the reaction between sodium hydrogen carbonate and dilute  hydrochloric acid is shown.    sodium chloride + water + carbon dioxide sodium hydrogen carbonate + dilute hydrochloric acidenergy     which row correctly describes the type of reaction an d the energy of the reactants and products?     type of reaction energy of the reactants  and products  a   endothermic   the products have more  energy than the reactants  b   endothermic   the reactants have more  energy than the products  c   exothermic   the products have more  energy than the reactants  d   exothermic   the reactants have more  energy than the products      12 the diagram shows some properties that substances may have.    to which labelled part of the diagram does 235u belong?    compoundused as  an energy  source  radioactive a  b d c       ",
            "6": "6  \u00a9 ucles 2016 0620/11/m/j/16  13 a liquid x reacts with solid y to form a gas.    which two diagrams show suitable methods for investigating the rate (speed) of the reaction?    x yxcotton wool cotton wool12 34y x yx ystopperbalance balancestopper     a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "7": "7  \u00a9 ucles 2016 0620/11/m/j/16 [turn over  14 an experiment, s, is carried out to measure the volume of hydrogen produced when excess dilute  sulfuric acid is added to zinc.    a second experiment, t, is carried out using the same mass of zinc but under different  conditions.    the results of the two experiments are shown.    00 timetotal volume of hydrogens t     which changes in the conditions between experiments s and t give curve t?     addition of  a catalyst the zinc is in large  pieces not powdered  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      15 aluminium reacts with iron( iii) oxide as shown.    iron( iii) oxide  +  aluminium  \u2192  iron  +  aluminium oxide    which statement about this reaction is correct?  a aluminium is oxidised.  b aluminium oxide is reduced.  c iron( iii) oxide is oxidised.  d iron is oxidised.      16 which reaction is reversible?  a cu  +  znso 4  \u2192  cuso 4  +  zn  b cuo  +  h 2so 4  \u2192  cuso 4  +  h 2o  c cuo  +  h 2  \u2192  cu  +  h 2o  d cuso 4.5h 2o  \u2192  cuso 4  +  5h 2o ",
            "8": "8  \u00a9 ucles 2016 0620/11/m/j/16  17 which statements are properties of an acid?    1 reacts with ammonium sulfate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     18 part of the periodic table is shown.    which element forms an acidic oxide?    ab c d      19 a method used to make copper( ii) sulfate crystals is shown.    1 place dilute sulfuric acid in a beaker.  2 warm the acid.  3 add copper( ii) oxide until it is in excess.  4 filter the mixture.  5 evaporate the filtrate until crystals start to form. 6 leave the filtrate to cool.    what are the purposes of step 3 and step 4?     step 3 step 4  a to ensure all of the acid has reacted to obtain solid copper( ii) sulfate  b to ensure all of the acid has reacted to remove excess copper( ii) oxide  c to speed up the reaction to obtain solid copper( ii) sulfate  d to speed up the reaction to remove excess copper( ii) oxide     ",
            "9": "9  \u00a9 ucles 2016 0620/11/m/j/16 [turn over  20 the results of two tests on solid x are shown.    test observation  aqueous sodium hydroxide added green precipitate formed  acidified silver nitrate added yellow precipitate formed    what is x?  a copper( ii) chloride  b copper( ii) iodide  c iron( ii) chloride  d iron( ii) iodide      21 where in the periodic table is the metallic character of the elements greatest?     left or right  side of a period at the top or bottom  of a group  a left bottom  b left top  c right bottom  d right top     22 some properties of four elements, p, q, r and s, are shown in the table.    two of these elements are in group i of the periodic table and two are in group vii.    element reaction with water physical state at  room temperature  p reacts vigorously solid  q does not react with water solid  r reacts explosively solid  s dissolves giving a coloured solution liquid    which statement is correct?  a p is below r in group i.  b q is above r in group i.  c q is below s in group vii.  d r is below s in group vii.     ",
            "10": "10  \u00a9 ucles 2016 0620/11/m/j/16  23 which of the following could be a transition element?     melting point  in \u00b0c density in  g / cm3 colour electrical  conductor  a 114 4.9 purple no  b 659 2.7 grey yes  c 1677 4.5 grey yes  d 3727 2.3 black yes      24 two statements about argon are given.     1 argon has a full outer shell of electrons.     2 argon is very reactive and is used in lamps.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.      25 three students, x, y and z, were told that solid p reacts with dilute acids and also conducts  electricity.    the table shows the students\u2019 suggestions about the identity of p.    x y z  copper iron graphite    which of the students are correct?  a x, y and z b x only c y only d z only     ",
            "11": "11  \u00a9 ucles 2016 0620/11/m/j/16 [turn over  26 w, x and y are metals, one of which is copper and one of which is iron.    \u2022 w has a coloured oxide which can be reduced by carbon.  \u2022 x has a black oxide and is also found in nature as a pure metal.  \u2022 y has an oxide which cannot be reduced by carbon.    which metal is the most reactive and what is the possible identity of w?     most reactive  metal possible identity  of w  a x cu  b x fe  c y cu  d y fe     27 tin is a metal that is less reactive than iron and is extracted from its ore cassiterite, sno 2.    which statements about tin are correct?    1 tin can be extracted from cassiterite using carbon.  2 tin does not conduct electricity. 3 tin is hard and shiny.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     28 which statement about the uses of metals is correct?  a aluminium is used in the manufacture of aircraft because of its strength and high density.  b copper is used in electrical wiring because of its strength and high density.  c mild steel is used in the manufacture of car bodies because of its strength and resistance to  corrosion.  d stainless steel is used in the construction of chemical plant because of its strength and  resistance to corrosion.    ",
            "12": "12  \u00a9 ucles 2016 0620/11/m/j/16  29 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change     30 a new planet has been discovered a nd its atmosphere has been analysed.    atmosphere planet     the table shows the composition of its atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only   ",
            "13": "13  \u00a9 ucles 2016 0620/11/m/j/16 [turn over  31 water was added to separate samples of anhydrous cobalt( ii) chloride and anhydrous  copper( ii) sulfate.    which row describes the colour changes that take place in these reactions?     cobalt( ii) chloride copper( ii) sulfate  a blue to pink blue to white  b blue to pink white to blue  c pink to blue blue to white  d pink to blue white to blue      32 which pollutant found in air does not have an effect on respiration?  a carbon monoxide  b lead compounds  c oxides of nitrogen  d sulfur dioxide      33 a farmer\u2019s soil is very low in both nitrogen (n) and phosphorus (p).    which fertiliser would improve the quality of this soil most effectively?     percentage  nitrogen (n) phosphorus (p) potassium (k)  a 11 11 27  b 12 37 10  c 28 10 10  d 31 29 9     34 when limestone is heated it forms lime (calcium oxide) and carbon dioxide.    caco 3(s)  \u2192  cao(s)  +  co 2(g)    which statement is not correct?  a carbon dioxide is a greenhouse gas which may contribute to climate change.  b slaked lime is used to neutralise industrial waste.  c the lime can be used to treat alkaline soil.  d this reaction is an example of thermal decomposition.    ",
            "14": "14  \u00a9 ucles 2016 0620/11/m/j/16  35 the diagram shows the separation of petroleum into fractions.    gasoline x y z bitumenpetroleum     what could x, y and z represent?     x y z  a diesel oil lubricating fraction paraffin  b lubricating fraction diesel oil paraffin  c paraffin lubricating fraction diesel oil  d paraffin diesel oil lubricating fraction     36 which of the compounds shown are in the same homologous series?    1 ch 3oh  2 ch 3ch 2oh  3 ch 3cooh  4 ch 3ch 2ch 2oh    a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4      37 compound q decolourises bromine water.    compound q has two carbon atoms in each molecule.    which statement about compound q is correct?  a it contains carbon-hydrogen double bonds.  b it has six hydrogen atoms per molecule.  c it has two carbon-carbon double bonds.  d it is produced by cracking alkanes.     ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/11/m/j/16  38 what is used in the production of ethanol from ethene?  a hydrogen and oxygen  b oxygen only  c steam  d yeast      39 ethene forms an addition polymer as shown.    h c .. + hh c+ hh chh c + .. .. .. hh chh c hh c hh c h    which terms describe this polymer?  a a saturated compound called poly(ethane)  b a saturated compound called poly(ethene)  c an unsaturated compound called poly(ethane)  d an unsaturated compound called poly(ethene)     40 the diagram shows a molecule of an organic compound w.    h c hh c oho     which statement is not correct?  a a solution of w in water has a ph greater than ph 7.  b a solution of w in water reacts with sodium hydroxide solution.  c when copper( ii) carbonate is added to a solution of w in water, a gas is produced.  d when magnesium is added to a solution of w in water, a gas is produced.     ",
            "16": "16  \u00a9 ucles 2016 0620/11/m/j/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s16_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 17 printed pages and 3 blank pages.  ib16 06_0620_12/3rp  \u00a9 ucles 2016 [turn over       *2847144730* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice (core)  may/june 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2016 0620/12/m/j/16  1 in which changes do the particles move further apart?     w x  gas      liquid      solid   y z    a w and x b w and z c x and y d y and z      2 in the chromatography experiment shown, which label represents the solvent front?    cdba      3 one of the instructions for an experiment reads as follows.    quickly add 50  cm3 of acid.    what is the best piece of apparatus to use?  a a burette  b a conical flask  c a measuring cylinder  d a pipette      4 two statements about diamond are given.    1 diamond has a giant three-dimensional covalent structure of carbon atoms.  2 diamond is one of the hardest substances known.    which is correct?  a both statements are correct and statement 1 explains statement 2.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     ",
            "3": "3  \u00a9 ucles 2016 0620/12/m/j/16 [turn over  5 the table shows the electronic structure of four atoms.    atom electronic structure  w 2,8,1  x 2,8,4  y 2,8,7  z 2,8,8    which two atoms combine to form a covalent compound?  a w and x b w and y c x and y d x and z      6 an atom of element q contains 19 electrons, 19 protons and 20 neutrons.    what is q?  a calcium  b potassium  c strontium  d yttrium     7 lithium is in group i of the periodic table. nitrogen is in group v of the periodic table.    lithium reacts with nitrogen to form the ionic compound lithium nitride.    what happens to the electrons when lithium atoms and nitrogen atoms form ions?     lithium atoms nitrogen atoms  a   each lithium atom loses one  electron to form a li+ ion each nitrogen atom gains three  electrons to form an n3\u2013 ion  b   each lithium atom loses one  electron to form a li+ ion each nitrogen atom gains five  electrons to form an n5\u2013 ion  c   each lithium atom gains one  electron to form a li\u2013 ion each nitrogen atom loses three  electrons to form an n3+ ion  d   each lithium atom gains one  electron to form a li\u2013 ion each nitrogen atom loses five  electrons to form an n5+ ion    ",
            "4": "4  \u00a9 ucles 2016 0620/12/m/j/16  8 the equation shows the reaction between magnesium and sulfuric acid.  [ar: h, 1; o, 16; mg, 24; s, 32]    mg  +  h 2so 4  \u2192  mgso 4  +  h 2    in this reaction, which mass of magnesium sulfate is formed when 6  g of magnesium react with  excess sulfuric acid?  a 8 b 24 c 30 d 60     9 the diagram shows an electrical cable.    metal coreplastic coating     which statement about the substances used is correct?  a the coating is plastic because it conducts electricity well.  b the core is copper because it conducts electricity well.  c the core is copper because it is cheap and strong.  d the core is iron because it is cheap and strong.      10 what are the products at the electrodes when dilute sulfuric acid is electrolysed using inert  electrodes?     anode cathode  a hydrogen oxygen  b oxygen hydrogen  c sulfur oxygen  d sulfur dioxide hydrogen    ",
            "5": "5  \u00a9 ucles 2016 0620/12/m/j/16 [turn over  11 the energy level diagram for the reaction between magnesium and hydrochloric acid is shown.    mg  +  2hc l mgc l 2  +  h2energy     which statement about the reaction is not correct?  a energy is given out during the reaction.  b the products are at a lower energy level than the reactants.  c the reaction is endothermic.  d the temperature increases during the reaction.     12 the diagram shows some properties that substances may have.    to which labelled part of the diagram does  235u belong?    compoundused as  an energy  source  radioactive a  b d c      ",
            "6": "6  \u00a9 ucles 2016 0620/12/m/j/16  13 a liquid x reacts with solid y to form a gas.    which two diagrams show suitable methods for investigating the rate (speed) of the reaction?    x yxcotton wool cotton wool12 34y x yx ystopperbalance balancestopper     a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "7": "7  \u00a9 ucles 2016 0620/12/m/j/16 [turn over  14 the results of two separate reactions between excess calcium carbonate and hydrochloric acid  are shown.    volume of gas collected timefirst reactionsecond reaction 00    which statement explains the differences between the reactions?  a more calcium carbonate was used in the second reaction.  b the same volume of more concentrated acid was used in the second reaction.  c the second reaction was allowed to react for longer.  d the temperature was higher in the second reaction.     15 the equations below all show redox reactions.    fe 2o3  +  3co  \u2192  2fe  +  3co 2  2zno  +  c  \u2192  2zn  +  co 2  fe2o3  +  2a l  \u2192  a l 2o3  +  2fe  2co  +  2no  \u2192  2co 2  +  n 2    which oxide is oxidised in these reactions?  a fe2o3 b co c zno d no     16 in which reaction is the colour change from blue to white?    a heating hydrated cobalt( ii) chloride  b heating hydrated copper( ii) sulfate  c adding water to anhydrous cobalt( ii) chloride  d adding water to anhydrous copper( ii) sulfate     ",
            "8": "8  \u00a9 ucles 2016 0620/12/m/j/16  17 which statements are properties of an acid?    1 reacts with ammonium sulfate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     18 part of the periodic table is shown.    which element forms an acidic oxide?    a bc d      19 what is the correct sequence of steps for the preparation of a pure sample of copper( ii) sulfate  crystals from copper( ii) oxide and sulfuric acid?  a dissolving \u2192 crystallisation \u2192 evaporation \u2192 filtration  b dissolving \u2192 evaporation \u2192 filtration \u2192 crystallisation  c dissolving \u2192 filtration \u2192 crystallisation \u2192 evaporation  d dissolving \u2192 filtration \u2192 evaporation \u2192 crystallisation     ",
            "9": "9  \u00a9 ucles 2016 0620/12/m/j/16 [turn over  20 the following tests are carried out on an aqueous solution of salt x.    test observation  sodium hydroxide solution is added   a green precipitate is formed  which dissolves in excess  a small piece of aluminium foil is then  added to the mixture and the mixture is heateda gas is given off which turns  damp, red litmus paper blue    what is x?  a aluminium nitrate  b ammonium sulfate  c chromium( iii) nitrate  d iron( ii) nitrate      21 where in the periodic table is the metallic character of the elements greatest?     left or right  side of a period at the top or bottom  of a group  a left bottom  b left top  c right bottom  d right top     22 rubidium is a group i metal.    which statement about rubidium is not correct?  a it has a higher melting point than lithium.  b it has one electron in its outer shell.  c it reacts vigorously with water.  d it reacts with chlorine to form rubidium chloride, rbc l  .    ",
            "10": "10  \u00a9 ucles 2016 0620/12/m/j/16  23 the table gives information about four elements, p, q, r and s.     melting point  in \u00b0c electrical conductivity  of element when solid density in g  / cm3 colour of iodide  of element  p 98 good 0.97 white  q \u201339 good 13.53 red  r 1410 poor 2.33 colourless  s 1535 good 7.87 green    which elements could be transition elements?  a p, q and s b q and s only c r and s only d s only      24 part of the periodic table is shown.    which element is a gas that does not form a compound with potassium?    a b cd       25 which property is not considered a typical metallic property?  a good conductor of heat  b low melting point  c malleable (can be hammered into shape)  d strong    ",
            "11": "11  \u00a9 ucles 2016 0620/12/m/j/16 [turn over  26 some chemical properties of three metals w, x and y and their oxides are shown.    metal reaction with steam reaction with dilute  hydrochloric acid reaction of metal  oxide with carbon  w reacts reacts reacts  x no reaction no reaction reacts  y reacts reacts no reaction    what is the order of reactivity of these metals, most reactive first?  a w \u2192 y \u2192 x  b x \u2192 y \u2192 w  c y \u2192 w \u2192 x  d y \u2192 x \u2192 w     27 iron from a blast furnace is treated with oxygen and with calcium oxide to make steel.   which substances in the iron are removed?   oxygen removes calcium oxide  removes  a carbon acidic oxides  b carbon basic oxides  c iron acidic oxides  d iron basic oxides      28 copper is sometimes used to make cooking utensils.    saucepan gas ring    three properties of copper are given.    1 corrosion resistant  2 good conductor of electricity  3 good conductor of heat    which properties make copper a suitable metal for making cooking utensils?  a 1 and 3 b 1 only c 2 and 3 d 2 only   ",
            "12": "12  \u00a9 ucles 2016 0620/12/m/j/16  29 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change     30 a new planet has been discovered a nd its atmosphere has been analysed.    atmosphere planet     the table shows the composition of its atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only   ",
            "13": "13  \u00a9 ucles 2016 0620/12/m/j/16 [turn over  31 which of the following are tests for water?    1 it turns anhydrous copper( ii) sulfate blue.  2 it boils at 100  \u00b0c.  3 it turns anhydrous cobalt( ii) chloride paper blue.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     32 sulfur dioxide, carbon monoxide and oxides of nitrogen are common gaseous pollutants found in  the air.    which pollutants contribute to acid rain?  a carbon monoxide and sulfur dioxide  b oxides of nitrogen and sulfur dioxide  c oxides of nitrogen only  d sulfur dioxide only      33 which compound is not used as a fertiliser?  a ammonium phosphate  b ammonium sulfate  c calcium carbonate  d potassium nitrate    34 lime (calcium oxide) is used to treat waste water from a factory.    which substance is removed by the lime?  a ammonia  b sodium chloride  c sodium hydroxide  d sulfuric acid     ",
            "14": "14  \u00a9 ucles 2016 0620/12/m/j/16  35 the diagram shows the separation of petroleum into fractions.    gasoline x y z bitumenpetroleum     what could x, y and z represent?     x y z  a diesel oil lubricating fraction paraffin  b lubricating fraction diesel oil paraffin  c paraffin lubricating fraction diesel oil  d paraffin diesel oil lubricating fraction     36 which compound is not an alkane, c nh2n+2?  a ch 3ch 2ch 2ch 3  b (ch 3)2chch 3  c ch 3chchch 3  d (ch 3)3ch    ",
            "15": "15  \u00a9 ucles 2016 0620/12/m/j/16 [turn over  37 a hydrocarbon w burns to form carbon dioxide and water.    w decolourises bromine water.    what is the name of w and what is its structure?     name of w structure of w  a ethane ch hhh c h h  b ethane c c hh hh  c ethene ch hhh c h h  d ethene c c hh hh     38 which term describes the formation of ethanol from glucose?  a cracking  b distillation  c fermentation  d polymerisation    ",
            "16": "16  \u00a9 ucles 2016 0620/12/m/j/16  39 ethene forms an addition polymer as shown.    h c .. + hh c+ hh chh c + .. .. .. hh chh c hh c hh c h    which terms describe this polymer?  a a saturated compound called poly(ethane)  b a saturated compound called poly(ethene)  c an unsaturated compound called poly(ethane)  d an unsaturated compound called poly(ethene)     40 which statement about carboxylic acids is not correct?  a aqueous ethanoic acid has a ph below ph 7.  b they contain the functional group \u2013cooh.  c they produce carbon dioxide when reacted with a metal carbonate.  d methyl orange turns yellow in aqueous ethanoic acid.    ",
            "17": "17  \u00a9 ucles 2016 0620/12/m/j/16  blank page     ",
            "18": "18  \u00a9 ucles 2016 0620/12/m/j/16  blank page     ",
            "19": "19    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/12/m/j/16  blank page      ",
            "20": "20  \u00a9 ucles 2016 0620/12/m/j/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s16_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 16 printed pages.  ib16 06_0620_13/3rp  \u00a9 ucles 2016 [turn over       *8830351027* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice (core)  may/june 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2016 0620/13/m/j/16  1 in which changes do the particles move further apart?     w x  gas      liquid      solid   y z    a w and x b w and z c x and y d y and z      2 chromatography experiments are carried out on four substances, p, q, r and s.    the same solvent is used in each experiment.     the resulting chromatograms are shown below.    p q r sbaseline     which statement is not correct?  a p and q are pure substances.  b p and r are different substances.  c r and s are pure substances.  d s is a mixture of substances.     3 one of the instructions for an experiment reads as follows.    quickly add 50  cm3 of acid.    what is the best piece of apparatus to use?  a a burette  b a conical flask  c a measuring cylinder  d a pipette     ",
            "3": "3  \u00a9 ucles 2016 0620/13/m/j/16 [turn over  4 the structures of diamond and graphite are shown.    diamond graphite    which statement about diamond and graphite is not correct?  a diamond is used in cutting tools because the strong covalent bonds make it very hard.  b graphite acts a lubricant because of the weak bonds between the layers.  c graphite conducts electricity because the electrons between the layers are free to move.  d graphite has a low melting point because of the weak bonds between the layers.      5 the table shows the electronic structure of four atoms.    atom electronic structure  w 2,8,1  x 2,8,4  y 2,8,7  z 2,8,8    which two atoms combine to form a covalent compound?  a w and x b w and y c x and y d x and z     6 the table shows the atomic structure of four atoms.    which atom is not a metal?     electrons neutrons protons  a 18 22 18  b 19 20 19  c 19 21 19  d 20 20 20    ",
            "4": "4  \u00a9 ucles 2016 0620/13/m/j/16  7 potassium, k, forms a compound with fluorine, f.    which statements about this compound are correct?    1 the compound is ionic.  2 the formula of the compound is kf.  3 the compound is soluble in water.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     8 the equation shows the reaction between magnesium and sulfuric acid.  [a r: h, 1; o, 16; mg, 24; s, 32]    mg  +  h 2so 4  \u2192  mgso 4  +  h 2    in this reaction, which mass of magnesium sulfate is formed when 6  g of magnesium react with  excess sulfuric acid?  a 8 b 24 c 30 d 60      9 the diagram shows an electrical cable.    metal coreplastic coating     which statement about the substances used is correct?  a the coating is plastic because it conducts electricity well.  b the core is copper because it conducts electricity well.  c the core is copper because it is cheap and strong.  d the core is iron because it is cheap and strong.     ",
            "5": "5  \u00a9 ucles 2016 0620/13/m/j/16 [turn over  10 electricity is passed separately through concentrated hydrochloric acid, concentrated aqueous  sodium chloride and dilute sulfuric acid.    in which rows are the electrolysis products correctly named?      cathode product anode product  1   concentrated  hydrochloric acid hydrogen   chlorine    2   concentrated  aqueous sodium chloride sodium   chlorine    3 dilute sulfuric acid hydrogen oxygen    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      11 the energy level diagram shows the energy of the reactants and products in a chemical reaction.    reactants productsenergy     which row correctly describes the energy change and the type of reaction shown?     energy change type of reaction  a energy is given out  to the surroundings endothermic    b energy is given out  to the surroundings exothermic    c energy is taken in from  the surroundings endothermic    d energy is taken in from  the surroundings exothermic      ",
            "6": "6  \u00a9 ucles 2016 0620/13/m/j/16  12 the diagram shows some properties that substances may have.    to which labelled part of the diagram does 235u belong?    compoundused as  an energy  source  radioactive a  b d c       13 a liquid x reacts with solid y to form a gas.    which two diagrams show suitable methods for investigating the rate (speed) of the reaction?    x yxcotton wool cotton wool12 34y x yx ystopperbalance balancestopper     a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "7": "7  \u00a9 ucles 2016 0620/13/m/j/16 [turn over  14 magnesium is reacted with a dilute acid.     the hydrogen gas is collected and its volume measured.    the results are shown on the graph.    40 302010 0 01234 time  / minutesvolume of hydrogen  / cm3 5678     between which times was the reaction fastest?  a 0 and 1 minute  b 1 and 2 minutes  c 2 and 3 minutes  d 7 and 8 minutes      15 a violent reaction occurs when a mixture of chromium( iii) oxide and aluminium is ignited with a  magnesium fuse as shown.    cruciblemagnesium fuse mixture of chromium( iii) oxide and aluminium sand    the equation for the reaction is shown.    cr2o3  +  2a l  \u2192  2cr  +  a l 2o3    which substance is oxidised in the reaction?  a aluminium  b aluminium oxide  c chromium  d chromium( iii) oxide   ",
            "8": "8  \u00a9 ucles 2016 0620/13/m/j/16  16 equations for the effect of water on anhydrous cobalt( ii) chloride and anhydrous  copper( ii) sulfate are shown.    coc l 2(s)  +  6h 2o(l)  \u2192  coc l 2.6h 2o(s)  cuso 4(s)  +  5h 2o(l)  \u2192  cuso 4.5h 2o(s)    which statement is not correct?  a both reactions can be reversed by changing the conditions.  b both reactions can be used as a test for water.  c the colour change observed when hydrated copper( ii) sulfate is heated is from blue to white.  d the colour change observed when water is added to anhydrous cobalt( ii) chloride is from  pink to blue.     17 which statements are properties of an acid?    1 reacts with ammonium sulfate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      18 part of the periodic table is shown.    which element forms an acidic oxide?    a bc d     ",
            "9": "9  \u00a9 ucles 2016 0620/13/m/j/16 [turn over  19 salts can be made by adding different substances to dilute hydrochloric acid.    for which substance could any excess not be removed by filtration?  a copper( ii) oxide  b magnesium  c sodium hydroxide  d zinc hydroxide      20 a solution containing substance x was tested. the table shows the results.    test result  flame test lilac colour  acidified silver nitrate solution added yellow precipitate    what is x?  a lithium bromide  b lithium iodide  c potassium bromide  d potassium iodide     21 where in the periodic table is the metallic character of the elements greatest?     left or right  side of a period at the top or bottom  of a group  a left bottom  b left top  c right bottom  d right top      22 which statement about the elements in group i is correct?  a hydrogen is evolved when they react with water.  b ions of group i elements have a \u20131 charge.  c sodium is more reactive than potassium.  d solid sodium is a poor electrical conductor.    ",
            "10": "10  \u00a9 ucles 2016 0620/13/m/j/16  23 osmium is a transition element.    which row gives the expected properties of osmium?     melting point density compounds  formed  a high high coloured  b high high white  c high low white  d low high coloured      24 two statements about noble gases are given.      1 noble gases are reactive, monatomic gases.    2 noble gases all have full outer shells of electrons.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     25 some properties of substance x are listed.    \u25cf it conducts electricity when molten.  \u25cf it has a high melting point.  \u25cf it burns in oxygen and the product dissolves in water to give a solution with ph 11.    what is x?  a a covalent compound  b a macromolecule  c a metal  d an ionic compound     ",
            "11": "11  \u00a9 ucles 2016 0620/13/m/j/16 [turn over  26 the list shows the order of reactivity of some elements.    k         na         ca         mg         zn         fe         (h)         cu    which statement about the reactivity of these metals is correct?  a copper reacts with steam to form hydrogen gas.  b magnesium is more reactive than calcium.  c potassium reacts with water to form hydrogen gas.  d sodium oxide is reduced by carbon to sodium.      27 iron is obtained from its ore in a blast furnace and is used to make steel.    iron obtained from the blast furnace is contaminated with ..1.. .    in order to remove this substance, ..2.. is passed through the molten iron.    ..3.. is also added to remove oxides of phosphorus and silicon which are ..4.. .    which words complete the sentences about the conversion of iron to steel?     1 2 3 4  a carbon nitrogen calcium carbonate acidic  b carbon oxygen calcium oxide acidic  c carbon oxygen calcium oxide basic  d sand oxygen calcium oxide basic     28 copper is a transition element used to make saucepans.    which property is not correct for copper?  a good conductor of heat  b insoluble in water  c low melting point  d malleable (can be hammered into shape)    ",
            "12": "12  \u00a9 ucles 2016 0620/13/m/j/16  29 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change     30 a new planet has been discovered a nd its atmosphere has been analysed.    atmosphere planet     the table shows the composition of its atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only   ",
            "13": "13  \u00a9 ucles 2016 0620/13/m/j/16 [turn over  31 the following substances can be formed when petrol is burnt in a car engine.    which substance is the main cause of acid rain?  a carbon  b carbon monoxide  c nitrogen dioxide  d water     32 which statement about methane is not correct?  a it is a greenhouse gas.  b it is an alkene.  c it is formed by decomposition of vegetation.  d it is used as a fuel.    33 the formulae of four compounds, w, x y and z, are given.  compound formula  w feso 4  x (nh 4)3po 4  y kno 3  z nac l    which mixture of compounds makes a complete fertiliser?  a w and x b w and z c x and y d y and z    34 which process is used to make lime (calcium oxide) from limestone (calcium carbonate)?  a chromatography  b electrolysis  c fractional distillation  d thermal decomposition    ",
            "14": "14  \u00a9 ucles 2016 0620/13/m/j/16  35 the diagram shows the separation of petroleum into fractions.    gasoline x y z bitumenpetroleum     what could x, y and z represent?     x y z  a diesel oil lubricating fraction paraffin  b lubricating fraction diesel oil paraffin  c paraffin lubricating fraction diesel oil  d paraffin diesel oil lubricating fraction     36 which compound does not belong to the same homologous series as the other three  compounds?  a ch 3oh b c 2h5cooh c c 2h5oh d c 7h15oh    37 which reaction is used as a test for alkenes?  a alkenes burn in air to give carbon dioxide and water.  b alkenes decolourise aqueous bromine.  c alkenes form polymers when heated in the presence of a catalyst.  d alkenes react with steam to form alcohols.    38 which statement about ethanol is correct?  a it burns in air to form ethene and water.  b it is prepared from ethene by fermentation.  c it is prepared from glucose in an addition reaction.  d it is the only product when ethene reacts with steam.    ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/13/m/j/16  39 ethene forms an addition polymer as shown.    h c .. + hh c+ hh chh c + .. .. .. hh chh c hh c hh c h    which terms describe this polymer?  a a saturated compound called poly(ethane)  b a saturated compound called poly(ethene)  c an unsaturated compound called poly(ethane)  d an unsaturated compound called poly(ethene)     40 liquid w burns completely to give carbon dioxide and water.    liquid w is a compound containing carbon, hydrogen and oxygen.    a solution of liquid w in water is ph  7.    what is liquid w?  a ethanoic acid  b ethanol  c gasoline  d methane     ",
            "16": "16  \u00a9 ucles 2016 0620/13/m/j/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s16_qp_21.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 17 printed pages and 3 blank pages.  ib16 06_0620_21/4rp  \u00a9 ucles 2016 [turn over       *6622954837* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/21     paper 2 multiple choice (extended)  may/june 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2016 0620/21/m/j/16  1 the rate of diffusion of two gases, methane, ch 4, and ethene, c 2h4, is measured using the  apparatus shown.    constant pressureapplied gas syringe gasmetal foil \u2013 gasescapes throughsmall hole in the foil     which gas diffuses faster and why?     gas that  diffuses faster reason  a   ethene   ethene molecules are heavier and so move faster.    b   ethene   ethene molecules have a double bond which makes them more reactive.  c methane methane molecules are lighter and so move faster.  d   methane   methane molecules are smaller so they can get out of the small hole more easily.      2 a sample of a dye is investigated by chromatography.    a line is drawn across a piece of chromatography paper and a spot of the dye is placed on it.    the paper is placed in water.    waterchromatography paper line spot of dye     which row is correct?     what is used to   draw the line position of spot  a ink above the level of the water  b ink below the level of the water  c pencil above the level of the water  d pencil below the level of the water     ",
            "3": "3  \u00a9 ucles 2016 0620/21/m/j/16 [turn over  3 the paper chromatogram below was obtained from four different dyes.    which dye has an rf value of 0.7?    abcdsolvent front baseline       4 which statements about isotopes of the same element are correct?    1 they are atoms which have the same chemical properties because they have the  same number of electrons in their outer shell.  2 they are atoms which have the same number of electrons and neutrons but  different numbers of protons.  3 they are atoms which have the same number of electrons and protons but different  numbers of neutrons.    a 1 and 2 b 1 and 3 c 2 only d 3 only     5 the table shows the electronic structure of four atoms.    atom electronic structure  w 2,8,1  x 2,8,4  y 2,8,7  z 2,8,8    which two atoms combine to form a covalent compound?  a w and x b w and y c x and y d x and z    ",
            "4": "4  \u00a9 ucles 2016 0620/21/m/j/16  6 which statement describes the attractive forces between molecules (intermolecular forces)?  a they are strong covalent bonds which hold molecules together.  b they are strong ionic bonds which hold molecules together.  c they are weak forces formed between covalently-bonded molecules.  d they are weak forces which hold ions together in a lattice.      7 the diagram represents the general structure of a solid z.    + + + + + ++ + +\u2013\u2013 \u2013\u2013 \u2013 \u2013 \u2013\u2013 \u2013     what is z?  a aluminium  b iodine  c silicon dioxide  d sulfur     8 a compound, x, contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen by mass.     the relative molecular mass, m r, of x is 60.    what is the molecular formula of x?  a ch 2o b ch 4o c c2h4o d c2h4o2      9 25  cm3 of 0.1  mol  / dm3 hydrochloric acid exactly neutralise 20  cm3 of aqueous sodium hydroxide.    the equation for this reaction is:    naoh  +  hc l  \u2192  nac l  +  h 2o    what is the concentration of the sodium hydroxide solution?  a 0.080  mol  / dm3  b 0.800  mol  / dm3  c 0.125  mol  / dm3  d 1.25  mol  / dm3     ",
            "5": "5  \u00a9 ucles 2016 0620/21/m/j/16 [turn over  10 which reactions could take place at the anode during electrolysis?    1 4oh\u2013(aq)  \u2192  2h 2o(i)  +  o 2(g)  +  4e\u2013  2 2c l \u2013(aq)  \u2192  c l 2(g)  +  2e\u2013  3 cu2+(aq)  +  2e\u2013  \u2192  cu(s)  4 2h+(aq)  +  2e\u2013  \u2192  h2(g)    a 1 and 2 b 1 and 4 c 2 and 4 d 3 and 4      11 the diagram shows some properties that substances may have.    to which labelled part of the diagram does 235u belong?    compoundused as  an energy  source  radioactive a  b d c       12 the diagram shows a simple cell.    voltmeter copper electrode zinc electrode electrolytev     which statement about the process occurring when the cell is in operation is correct?  a cu2+ ions are formed in solution.  b electrons travel through the solution.  c the reaction zn  \u2192  zn2+  +  2e\u2013 occurs.  d the zinc electrode increases in mass.   ",
            "6": "6  \u00a9 ucles 2016 0620/21/m/j/16  13 hydrogen burns exothermically in oxygen.    the equation for the reaction is:    2h2  +  o 2  \u2192  2h 2o    the table shows the bond energies involved.    bond bond energy in kj  / mol  h\u2013h 436  o=o 498  o\u2013h 464    what is the energy given out during the reaction?  a \u20133226  kj  / mol   b \u2013884  kj  / mol  c \u2013486  kj  / mol  d \u2013442  kj  / mol     ",
            "7": "7  \u00a9 ucles 2016 0620/21/m/j/16 [turn over  14 a liquid x reacts with solid y to form a gas.    which two diagrams show suitable methods for investigating the rate (speed) of the reaction?    x yxcotton wool cotton wool12 34y x yx ystopperbalance balancestopper     a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     15 which statements explain why increasing temperature increases the rate of a chemical reaction?    1 heat makes the molecules move faster and collide more often.  2 heat makes the molecules collide with more energy so they are more likely to react.  3 increasing temperature lowers the activation energy for the reaction.    a 1 and 2 b 1 and 3 c 1 only d 2 only    ",
            "8": "8  \u00a9 ucles 2016 0620/21/m/j/16  16 steam reacts with carbon in an endothermic reaction.    c(s)  +  h 2o(g)    co(g)  +  h 2(g)    which conditions of temperature and pressure would give the largest yield of hydrogen?     temperature pressure  a high high  b high low  c low high  d low low      17 which equation represents a reduction reaction?  a fe2+  +  e\u2013  \u2192  fe3+  b fe2+  \u2192  fe3+  +  e\u2013  c fe3+  +  e\u2013  \u2192  fe2+  d fe3+  \u2192  fe2+  +  e\u2013      18 which statements are properties of an acid?    1 reacts with ammonium sulfate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     19 which row describes whether an amphoteric oxide reacts with acids and bases?     reacts with acids reacts with bases  a no no  b no yes  c yes no  d yes yes     ",
            "9": "9  \u00a9 ucles 2016 0620/21/m/j/16 [turn over  20 which substance reacts with dilute sulfuric acid to form a salt that can be removed from the  resulting mixture by filtration?  a aqueous barium chloride  b aqueous sodium hydroxide  c copper  d copper( ii) carbonate      21 where in the periodic table is the metallic character of the elements greatest?     left or right  side of a period at the top or bottom  of a group  a left bottom  b left top  c right bottom  d right top     22 some properties of four elements, p, q, r and s, are shown in the table.    two of these elements are in group i of the periodic table and two are in group vii.    element reaction with water physical state at  room temperature  p reacts vigorously solid  q does not react with water solid  r reacts explosively solid  s dissolves giving a coloured solution liquid    which statement is correct?  a p is below r in group i.  b q is above r in group i.  c q is below s in group vii.  d r is below s in group vii.     ",
            "10": "10  \u00a9 ucles 2016 0620/21/m/j/16  23 which of the following could be a transition element?     melting point  in \u00b0c density in  g / cm3 colour electrical  conductor  a 114 4.9 purple no  b 659 2.7 grey yes  c 1677 4.5 grey yes  d 3727 2.3 black yes      24 two statements about argon are given.     1 argon has a full outer shell of electrons.     2 argon is very reactive and is used in lamps.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.      25 a student investigated the reactions of four metals, r, s, t and u, with solutions of their salts.    the results are given in the table.    metal metal salt result  r  r  s s nitrate  t nitrate  u nitrate reacts reacts  no reaction  t u nitrate reacts  u r nitrate no reaction    what is the order of reactivity of the metals, most reactive first?  a r \u2192 s \u2192 u \u2192 t  b r \u2192 t \u2192 u \u2192 s  c s \u2192 u \u2192 t\u2192 r  d u \u2192 r \u2192 t \u2192 s     ",
            "11": "11  \u00a9 ucles 2016 0620/21/m/j/16 [turn over  26 three students, x, y and z, were told that solid p reacts with dilute acids and also conducts  electricity.    the table shows the students\u2019 suggestions about the identity of p.    x y z  copper iron graphite    which of the students are correct?  a x, y and z b x only c y only d z only      27 which statement about the uses of metals is correct?  a aluminium is used in the manufacture of aircraft because of its strength and high density.  b copper is used in electrical wiring because of its strength and high density.  c mild steel is used in the manufacture of car bodies because of its strength and resistance to  corrosion.  d stainless steel is used in the construction of chemical plant because of its strength and  resistance to corrosion.    28 aluminium is manufactured by electrolysis of aluminium oxide.    the diagram shows the electrolysis cell.    molten aluminiumaluminium oxide in molten cryolite cathodeanode ++     which statement about the process is not correct?  a aluminium ions gain electrons during the electrolysis and are reduced.  b cryolite is added to reduce the melting point of the aluminium oxide.  c the anode and cathode are made of graphite.  d the cathode has to be replaced regularly because it is burnt away.     ",
            "12": "12  \u00a9 ucles 2016 0620/21/m/j/16  29 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change     30 a new planet has been discovered a nd its atmosphere has been analysed.    atmosphere planet     the table shows the composition of its atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only   ",
            "13": "13  \u00a9 ucles 2016 0620/21/m/j/16 [turn over  31 many car exhaust systems contain a catalytic converter.    which change does not occur in a catalytic converter?  a carbon dioxide \u2192 carbon  b carbon monoxide \u2192 carbon dioxide  c nitrogen oxides \u2192 nitrogen  d unburnt hydrocarbons \u2192 carbon dioxide and water      32 ammonia is formed by a reversible reaction.    n2(g)  +  3h 2(g)    2nh 3(g)    the forward reaction is exothermic.  which changes in conditions would increase the yield of ammonia?     increase in  pressure increase in  temperature  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017      33 the equation for an exothermic reaction in the contact process is shown.    2so 2(g)  +  o 2(g)  \u2192  2so 3(g)    which effects do increasing the temperature and using a catalyst have on the rate of formation of sulfur trioxide, so 3?     increasing the  temperature using a  catalyst  a rate decreases rate decreases  b rate decreases rate increases  c rate increases rate decreases  d rate increases rate increases     ",
            "14": "14  \u00a9 ucles 2016 0620/21/m/j/16  34 a farmer\u2019s soil is very low in both nitrogen (n) and phosphorus (p).    which fertiliser would improve the quality of this soil most effectively?     percentage  nitrogen (n) phosphorus (p) potassium (k)  a 11 11 27  b 12 37 10  c 28 10 10  d 31 29 9     35 the diagram shows the separation of petroleum into fractions.    gasoline x y z bitumenpetroleum     what could x, y and z represent?     x y z  a diesel oil lubricating fraction paraffin  b lubricating fraction diesel oil paraffin  c paraffin lubricating fraction diesel oil  d paraffin diesel oil lubricating fraction     ",
            "15": "15  \u00a9 ucles 2016 0620/21/m/j/16 [turn over  36 which of the compounds shown are in the same homologous series?    1 ch 3oh  2 ch 3ch 2oh  3 ch 3cooh  4 ch 3ch 2ch 2oh    a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4     37 which compounds contain the same number of carbon, hydrogen and oxygen atoms?    w x y z  ethyl methanoate methyl ethanoate methyl methanoate ethyl ethanoate    a w and x b w and y c x and z d y and z     38 what is an advantage of producing ethanol by fermentation of sugar compared to the catalytic  addition of steam to ethene?  a the alcohol produced is purer.  b the process is faster.  c the process uses high temperature.  d the process uses renewable raw materials.     ",
            "16": "16  \u00a9 ucles 2016 0620/21/m/j/16  39 the structure of a monomer is shown.    ccl hc hf     which polymer can be made from this monomer?    clcl clcl cc clcl c clcl ca hcl hf cc hcl c hf cb clcl ff cc clcl c ff cc clf clf cc clf c clf cd     40 which formula represents a polyester?    c do co c co o n hn hn hn hcon bh nh co co on hc c co co c co o o oo oa o o o o     ",
            "17": "17  \u00a9 ucles 2016 0620/21/m/j/16  blank page     ",
            "18": "18  \u00a9 ucles 2016 0620/21/m/j/16  blank page     ",
            "19": "19    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/21/m/j/16  blank page      ",
            "20": "20  \u00a9 ucles 2016 0620/21/m/j/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s16_qp_22.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 16 printed pages.  ib16 06_0620_22/4rp  \u00a9 ucles 2016 [turn over       *1301766353* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2 multiple choice (extended)  may/june 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2016 0620/22/m/j/16  1 the particles of a substance gain energy and change from a regular ordered structure to a  disordered structure with large distances between the particles.    which change of state is described?  a boiling  b evaporation  c melting  d sublimation     2 in the chromatography experiment shown, which label represents the solvent front?    cdba      3 x is a mixture of colourless compounds. the diagram shows a chromatogram of x and of three  pure compounds, p, q and r.    xpqr    which statement is not correct?  a a locating agent was used to develop the chromatogram of x.  b p and r could be present in x.  c p and r have different solubilities in the solvent.  d q has a greater rf value than r.     ",
            "3": "3  \u00a9 ucles 2016 0620/22/m/j/16 [turn over  4 which statements about isotopes of the same element are correct?    1 they are atoms which have the same chemical properties because they have the  same number of electrons in their outer shell.  2 they are atoms which have the same number of electrons and neutrons but  different numbers of protons.  3 they are atoms which have the same number of electrons and protons but different  numbers of neutrons.    a 1 and 2 b 1 and 3 c 2 only d 3 only     5 the table shows the electronic structure of four atoms.    atom electronic structure  w 2,8,1  x 2,8,4  y 2,8,7  z 2,8,8    which two atoms combine to form a covalent compound?  a w and x b w and y c x and y d x and z    6 which statement describes the attractive forces between molecules (intermolecular forces)?  a they are strong covalent bonds which hold molecules together.  b they are strong ionic bonds which hold molecules together.  c they are weak forces formed between covalently-bonded molecules.  d they are weak forces which hold ions together in a lattice.     7 metals consist of a lattice of positive ions in a \u2018sea of electrons\u2019.    why is aluminium malleable?  a its ions are attracted to the \u2018sea of electrons\u2019.  b its ions are tightly packed together.  c its ions repel each other.  d its layers of ions can slide over each other.     ",
            "4": "4  \u00a9 ucles 2016 0620/22/m/j/16  8 a sample of 16.0  g of a metal oxide, mo, is reduced to 12.8  g of the metal, m.    what is the relative atomic mass, ar, of m?  a 32 b 64 c 80 d 128     9 the equation for the reaction between calcium carbonate and hydrochloric acid is shown.    caco 3(s)  +  2hc l (aq)  \u2192  cac l 2(aq)  +  h 2o(l)  +  co 2(g)    how many moles of calcium carbonate will give 24  cm3 of carbon dioxide when reacted with an  excess of the acid?    a 1  mol b 0.1  mol c 0.01  mol d 0.001  mol     10 the diagram shows the electrolysis of molten zinc chloride, znc l  2.    electrode yelectrode x molten zinc chloride+\u2013     which statement is correct?  a oxidation occurs at electrode x and the equation is: 2c l \u2013  \u2192  c l 2  +  2e\u2013.  b oxidation occurs at electrode y and the equation is: zn2+  +  2e\u2013  \u2192  zn.  c reduction occurs at electrode x and the equation is: zn2+  +  2e\u2013  \u2192  zn.  d reduction occurs at electrode y and the equation is: 2c l \u2013  \u2192  c l 2  +  2e\u2013.     ",
            "5": "5  \u00a9 ucles 2016 0620/22/m/j/16 [turn over  11 the diagram shows some properties that substances may have.    to which labelled part of the diagram does 235u belong?    compoundused as  an energy  source  radioactive a  b d c       12 the diagram shows a simple cell.    dilute sulfuric acidmetal y metal xflow of electrons wire     for which pair of metals would electrons flow from metal x to metal y?     x y  a copper iron  b copper zinc  c iron zinc  d zinc iron     ",
            "6": "6  \u00a9 ucles 2016 0620/22/m/j/16  13 the energy level diagram for the combustion of methane is shown.    ch4(g)  +  2o2(g) co2(g)  +  2h2o(g)energy energy change     which row gives the equation and energy change for this reaction?   equation energy change in kj  / mol  a ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(g) +891  b ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(g) \u2013891  c ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(i) +891  d ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(i) \u2013891     ",
            "7": "7  \u00a9 ucles 2016 0620/22/m/j/16 [turn over  14 a liquid x reacts with solid y to form a gas.    which two diagrams show suitable methods for investigating the rate (speed) of the reaction?    x yxcotton wool cotton wool12 34y x yx ystopperbalance balancestopper     a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     15 which row describes how the energy of collision between particles changes when concentration  and temperature are increased?     concentration temperature  a increases increases  b increases no change  c no change increases  d no change no change     ",
            "8": "8  \u00a9 ucles 2016 0620/22/m/j/16  16 methanol is made by reacting carbon monoxide with hydrogen.    the reaction is exothermic and is a chemical equilibrium.    the equation for the reaction is shown.    co(g)  +  2h 2(g)    ch 3oh(g)    which changes in temperature and pressure increase the yield of methanol?     temperature pressure  a decrease decrease  b decrease increase  c increase decrease  d increase increase      17 which equation represents a reduction reaction?  a fe2+  +  e\u2013  \u2192  fe3+  b fe2+  \u2192  fe3+  +  e\u2013  c fe3+  +  e\u2013  \u2192  fe2+  d fe3+  \u2192  fe2+  +  e\u2013     18 which statements are properties of an acid?    1 reacts with ammonium sulfate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "9": "9  \u00a9 ucles 2016 0620/22/m/j/16 [turn over  19 which row describes whether an amphoteric oxide reacts with acids and bases?     reacts with acids reacts with bases  a no no  b no yes  c yes no  d yes yes     20 silver chloride is insoluble in water and is prepared by precipitation.    which two substances can be used to make silver chloride?  a barium chloride and silver nitrate  b hydrochloric acid and silver  c hydrochloric acid and silver bromide  d sodium chloride and silver iodide      21 where in the periodic table is the metallic character of the elements greatest?     left or right  side of a period at the top or bottom  of a group  a left bottom  b left top  c right bottom  d right top     22 rubidium is a group i metal.    which statement about rubidium is not correct?  a it has a higher melting point than lithium.  b it has one electron in its outer shell.  c it reacts vigorously with water.  d it reacts with chlorine to form rubidium chloride, rbc l  .    ",
            "10": "10  \u00a9 ucles 2016 0620/22/m/j/16  23 the table gives information about four elements, p, q, r and s.     melting point  in \u00b0c electrical conductivity  of element when solid density in g  / cm3 colour of iodide  of element  p 98 good 0.97 white  q \u201339 good 13.53 red  r 1410 poor 2.33 colourless  s 1535 good 7.87 green    which elements could be transition elements?  a p, q and s b q and s only c r and s only d s only      24 part of the periodic table is shown.    which element is a gas that does not form a compound with potassium?    a b cd       25 some magnesium compounds undergo thermal decomposition.    what are the products of thermal decomposition of magnesium nitrate, mg(no 3)2, and  magnesium hydroxide, mg(oh) 2?     mg(no 3)2 mg(oh) 2  a mgo, no 2 and o 2 mgo and h 2o  b mgo, no 2 and o 2 mgo and h 2  c mg(no 2)2 and o 2 mgo and h 2o  d mg(no 2)2 and o 2 mgo and h 2      26 which property is not considered a typical metallic property?  a good conductor of heat  b low melting point  c malleable (can be hammered into shape)  d strong    ",
            "11": "11  \u00a9 ucles 2016 0620/22/m/j/16 [turn over  27 iron from a blast furnace is treated with oxygen and with calcium oxide to make steel.   which substances in the iron are removed?   oxygen removes calcium oxide  removes  a carbon acidic oxides  b carbon basic oxides  c iron acidic oxides  d iron basic oxides     28 why is cryolite used during the extraction of aluminium by electrolysis?  a it is a catalyst for the reaction.  b it lowers the melting point of the electrolyte.  c it protects the anodes.  d it separates the aluminium from the electrolyte.    29 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change    ",
            "12": "12  \u00a9 ucles 2016 0620/22/m/j/16  30 a new planet has been discovered a nd its atmosphere has been analysed.    atmosphere planet     the table shows the composition of its atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only     31 the gases coming from a car\u2019s engine contain oxides of nitrogen.    how are these oxides formed?  a nitrogen reacts with carbon dioxide.  b nitrogen reacts with carbon monoxide.  c nitrogen reacts with oxygen.  d nitrogen reacts with petrol.     ",
            "13": "13  \u00a9 ucles 2016 0620/22/m/j/16 [turn over  32 ammonia is manufactured by a reversible reaction.    n2(g)  +  3h 2(g)    2nh 3(g)    the forward reaction is exothermic.    what is the effect of increasing the pressure on the percentage yield and rate of formation of  ammonia?     percentage yield rate of  formation  a decreases decreases  b decreases increases  c increases decreases  d increases increases      33 the contact process is used for the manufacture of sulfuric acid.    which statement about this process is not correct?  a a catalyst of iron is used.  b oxygen from the air is used to react with sulfur dioxide.  c sulfur trioxide dissolves in sulfuric acid to form oleum.  d the temperature used is around 450  \u00b0c.     34 lime (calcium oxide) is used to treat waste water from a factory.    which substance is removed by the lime?  a ammonia  b sodium chloride  c sodium hydroxide  d sulfuric acid     ",
            "14": "14  \u00a9 ucles 2016 0620/22/m/j/16  35 the diagram shows the separation of petroleum into fractions.    gasoline x y z bitumenpetroleum     what could x, y and z represent?     x y z  a diesel oil lubricating fraction paraffin  b lubricating fraction diesel oil paraffin  c paraffin lubricating fraction diesel oil  d paraffin diesel oil lubricating fraction     36 which compound is not an alkane, c nh2n+2?  a ch 3ch 2ch 2ch 3  b (ch 3)2chch 3  c ch 3chchch 3  d (ch 3)3ch    37 an ester is formed when a carboxylic acid reacts with an alcohol.    which ester is formed when propanoic acid and ethanol react?  a ch 3co 2ch 2ch 3  b ch 3co 2ch 2ch 2ch 3  c ch 3ch 2co 2ch 3  d ch 3ch 2co 2ch 2ch 3     ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/22/m/j/16  38 what is an advantage of producing ethanol by fermentation of sugar compared to the catalytic  addition of steam to ethene?  a the alcohol produced is purer.  b the process is faster.  c the process uses high temperature.  d the process uses renewable raw materials.      39 in which row are the monomer and polymer chain correctly matched?     monomer part of the polymer chain  a ch 3ch=chch 3 \u2013ch(ch 3)\u2013ch(ch 3)\u2013ch(ch 3)\u2013ch(ch 3)\u2013  b ch 2=chc l \u2013chc l \u2013chc l \u2013chc l \u2013chc l \u2013  c ch 3ch=ch 2 \u2013ch 3\u2013ch\u2013ch 2\u2013ch 3\u2013ch\u2013ch 2\u2013  d ch 2=chch 2ch 3 \u2013ch 2\u2013ch 2\u2013ch 2\u2013ch(ch 2ch 3)\u2013    40 which two polymers have the same linkages bonding the monomers together?  a nylon and complex carbohydrate  b nylon and protein  c terylene  and complex carbohydrate  d terylene  and protein    ",
            "16": "16  \u00a9 ucles 2016 0620/22/m/j/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s16_qp_23.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 17 printed pages and 3 blank pages.  ib16 06_0620_23/3rp  \u00a9 ucles 2016 [turn over       *0872645576* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/23     paper 2 multiple choice (extended)  may/june 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2016 0620/23/m/j/16  1 the diagram shows an experiment to demonstrate diffusion.    cotton wool soaked in hydrochloric acidcotton wool soaked in ammonia solutionammonium chloride    which statement explains why the ring of ammonium chloride appears as shown?  a ammonia solution only produces a gas which moves until it meets the hydrochloric acid.  b both solutions produce a gas, but ammonia moves quicker than hydrogen chloride because  it is lighter.  c hydrochloric acid produces hydrogen chloride which stays at one end of the tube until the  ammonia reaches it.  d the two solutions run along the tube until they meet.      2 chromatography experiments are carried out on four substances, p, q, r and s.    the same solvent is used in each experiment.     the resulting chromatograms are shown below.    p q r sbaseline     which statement is not correct?  a p and q are pure substances.  b p and r are different substances.  c r and s are pure substances.  d s is a mixture of substances.    ",
            "3": "3  \u00a9 ucles 2016 0620/23/m/j/16 [turn over  3 the diagram shows the apparatus used to separate the different components of a mixture by  chromatography.    baseline solventspotsolvent frontchromatography pape r     which statement about this experiment is correct?  a a locating agent is used to find the position of the solvent front.  b the components to be separated must be soluble in the solvent.  c the baseline on which the spot of the mixture is placed is drawn in ink.  d the rf value is calculated by component theby  travelled distance thefront solvent theby  travelled distance the      4 which statements about isotopes of the same element are correct?    1 they are atoms which have the same chemical properties because they have the  same number of electrons in their outer shell.  2 they are atoms which have the same number of electrons and neutrons but  different numbers of protons.  3 they are atoms which have the same number of electrons and protons but different  numbers of neutrons.    a 1 and 2 b 1 and 3 c 2 only d 3 only     ",
            "4": "4  \u00a9 ucles 2016 0620/23/m/j/16  5 the table shows the electronic structure of four atoms.    atom electronic structure  w 2,8,1  x 2,8,4  y 2,8,7  z 2,8,8    which two atoms combine to form a covalent compound?  a w and x b w and y c x and y d x and z      6 which statement describes the attractive forces between molecules (intermolecular forces)?  a they are strong covalent bonds which hold molecules together.  b they are strong ionic bonds which hold molecules together.  c they are weak forces formed between covalently-bonded molecules.  d they are weak forces which hold ions together in a lattice.      7 which substance exists as a lattice of positive ions in a \u2018sea of electrons\u2019?  a liquid potassium chloride  b solid graphite  c solid magnesium  d solid silicon( iv) oxide    8 analysis of a compound formed between magnesium and nitrogen showed it contained 14.4  g of  magnesium and 5.6  g of nitrogen.    what is the empirical formula of the compound?  a mg 2n3 b mg 3n2 c mg 4n6 d mg 6n4      9 an excess of zinc is added to 100  cm3 of 1.0  mol  / dm3 hydrochloric acid.    the equation for the reaction is:    zn  +  2hc l  \u2192  znc l  2  +  h 2    what is the maximum volume of hydrogen evolved at room temperature and pressure?   a 1.2  dm3 b 2.0  dm3 c 2.4  dm3 d 24  dm3     ",
            "5": "5  \u00a9 ucles 2016 0620/23/m/j/16 [turn over  10 the diagram shows a method used to copper-plate a pan    pan copper( ii) sulfate solutioncopper+\u2013     which equation represents the reaction at the cathode?  a cu2+  +  2e\u2013  \u2192  cu  b 2h+  +  2e\u2013  \u2192  h2  c 4oh\u2013  \u2192  o 2  +  2h 2o  +  4e\u2013  d 2o2\u2013  \u2192  o 2  +  4e\u2013      11 the diagram shows some properties that substances may have.    to which labelled part of the diagram does 235u belong?    compoundused as  an energy  source  radioactive a  b d c       ",
            "6": "6  \u00a9 ucles 2016 0620/23/m/j/16  12 the diagram shows a simple cell.    dilute sulfuric acidmetal q metal pwirev     which pair of metals produces the largest voltage?     metal p metal q  a iron copper  b magnesium copper  c magnesium zinc  d zinc copper     13 hydrazine, n 2h4, decomposes as shown.    nh hnn nh 2 + hhh     the energy change for this reaction is \u201395  kj / mol.    the table shows some bond energies involved.    bond bond energy in kj  / mol  nn 945  n\u2013h 391  h\u2013h 436    what is the bond energy of the n \u2013n bond?  a 158  kj / mol b 315  kj / mol c 348  kj / mol d 895  kj / mol     ",
            "7": "7  \u00a9 ucles 2016 0620/23/m/j/16 [turn over  14 a liquid x reacts with solid y to form a gas.    which two diagrams show suitable methods for investigating the rate (speed) of the reaction?    x yxcotton wool cotton wool12 34y x yx ystopperbalance balancestopper     a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     15 which row explains why increasing temperature increases the rate of reaction?     particles collide  more often particles collide  with more energy  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017    ",
            "8": "8  \u00a9 ucles 2016 0620/23/m/j/16  16 methanol is manufactured by reacting carbon monoxide and hydrogen together in the presence  of an aluminium oxide catalyst.    the equation for the reaction is shown.    co(g)  +  2h 2(g)    ch 3oh(g)    the reaction is a reversible reaction.    the forward reaction is exothermic.    which change in conditions increases the yield of methanol?  a decreasing the concentration of the carbon monoxide  b increasing the pressure  c increasing the rate of the reaction  d increasing the temperature     17 which equation represents a reduction reaction?  a fe 2+  +  e\u2013  \u2192  fe3+  b fe2+  \u2192  fe3+  +  e\u2013  c fe3+  +  e\u2013  \u2192  fe2+  d fe3+  \u2192  fe2+  +  e\u2013    18 which statements are properties of an acid?    1 reacts with ammonium sulfate to form ammonia  2 turns red litmus blue     1 2  a \u0013 \u0013  b \u0013 \u0017  c \u0017 \u0013  d \u0017 \u0017     ",
            "9": "9  \u00a9 ucles 2016 0620/23/m/j/16 [turn over  19 which row describes whether an amphoteric oxide reacts with acids and bases?     reacts with acids reacts with bases  a no no  b no yes  c yes no  d yes yes     20 barium sulfate is an insoluble salt.    it can be made by reacting copper( ii) sulfate solution with barium nitrate solution.    cuso 4(aq)  +  ba(no 3)2(aq)  \u2192  cu(no 3)2(aq)  +  baso 4(s)    what is the correct order of steps to obtain a pure, dry sample of barium sulfate from the reaction mixture?     step 1 step 2 step 3  a   filter   evaporate the filtrate  to dryness leave the solid formed  to cool  b   filter   evaporate the filtrate to the  point of crystallisation leave the filtrate to cool    c   filter   leave the residue in a  warm place to dry wash the residue  with water  d   filter   wash the residue  with water leave the residue in a  warm place to dry    21 where in the periodic table is the metallic character of the elements greatest?     left or right  side of a period at the top or bottom  of a group  a left bottom  b left top  c right bottom  d right top    ",
            "10": "10  \u00a9 ucles 2016 0620/23/m/j/16  22 which statement about the elements in group i is correct?  a hydrogen is evolved when they react with water.  b ions of group i elements have a \u20131 charge.  c sodium is more reactive than potassium.  d solid sodium is a poor electrical conductor.      23 osmium is a transition element.    which row gives the expected properties of osmium?     melting point density compounds  formed  a high high coloured  b high high white  c high low white  d low high coloured     24 two statements about noble gases are given.     1 noble gases are reactive, monatomic gases.    2 noble gases all have full outer shells of electrons.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statement 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     ",
            "11": "11  \u00a9 ucles 2016 0620/23/m/j/16 [turn over  25 some properties of substance x are listed.    \u25cf it conducts electricity when molten.  \u25cf it has a high melting point. \u25cf it burns in oxygen and the product dissolves in water to give a solution with ph 11.    what is x?  a a covalent compound  b a macromolecule  c a metal  d an ionic compound     26 four metals p, q, r and s are added to separate aqueous solutions of their ions.    the results are shown.    metal p 2+ q2+ r2+ s2+   p \u0017 \u0017 \u0013 \u0013 key  q \u0013 \u0017 \u0013 \u0013 \u0013= reaction occurs  r \u0017 \u0017 \u0017 \u0017 \u0017= reaction does not occur  s \u0017 \u0017 \u0013 \u0017     what is the order of reactivity of the metals, most reactive first?  a q \u2192 p \u2192 s \u2192 r  b q \u2192 s \u2192 p \u2192 r  c r \u2192 p \u2192 s \u2192 q  d r \u2192 s \u2192 p \u2192 q      27 copper is a transition element used to make saucepans.    which property is not correct for copper?  a good conductor of heat  b insoluble in water  c low melting point  d malleable (can be hammered into shape)     ",
            "12": "12  \u00a9 ucles 2016 0620/23/m/j/16  28 aluminium is extracted by electrolysis of a mixture of aluminium oxide and cryolite.    which statement is not correct?  a the electrodes are made from graphite.  b the formula for aluminium oxide is a l 2o3.  c the purpose of the cryolite is to lower the melting point of the mixture.  d the reaction taking place at the anode is a l 3+  +  3e\u2013  \u2192  a l .     29 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change    ",
            "13": "13  \u00a9 ucles 2016 0620/23/m/j/16 [turn over  30 a new planet has been discovered a nd its atmosphere has been analysed.    atmosphere planet     the table shows the composition of its atmosphere.    gas percentage by volume  carbon dioxide 4  nitrogen 72  oxygen 24    which gases are present in the atmosphere of the planet in a higher percentage than they are in  the earth\u2019s atmosphere?  a carbon dioxide and oxygen  b carbon dioxide only  c nitrogen and oxygen  d nitrogen only     31 catalytic converters are used to remove some gaseous pollutants from car exhaust fumes.    which gas is removed from the fumes by oxidation?   a carbon dioxide  b carbon monoxide  c nitrogen  d nitrogen oxide     32 ammonia is produced by the haber process.    n 2(g)  +  3h 2(g)  \u2192  2nh 3(g).    which statement about the haber process is not correct?  a an iron catalyst is used to increase the rate of reaction.  b the reaction is carried out at high temperature to increase the rate of reaction.  c the reaction is carried out at low pressure to increase the yield of ammonia.  d the reaction is reversible.   ",
            "14": "14  \u00a9 ucles 2016 0620/23/m/j/16  33 one step in the manufacture of sulfuric acid is the oxidation of sulfur dioxide to sulfur trioxide.    which conditions are used for this step?     temperature  / \u00b0c pressure  / atmospheres catalyst  a 450 1.5 iron  b 450 1.5 vanadium( v) oxide  c 450 200 iron  d 450 200 vanadium( v) oxide      34 which process is used to make lime (calcium oxide) from limestone (calcium carbonate)?  a chromatography  b electrolysis  c fractional distillation  d thermal decomposition     35 the diagram shows the separation of petroleum into fractions.    gasoline x y z bitumenpetroleum     what could x, y and z represent?     x y z  a diesel oil lubricating fraction paraffin  b lubricating fraction diesel oil paraffin  c paraffin lubricating fraction diesel oil  d paraffin diesel oil lubricating fraction    ",
            "15": "15  \u00a9 ucles 2016 0620/23/m/j/16 [turn over  36 which compound does not belong to the same homologous series as the other three  compounds?  a ch 3oh b c 2h5cooh c c 2h5oh d c 7h15oh      37 the structure of an alkene and the structure of an ester are shown.    c hh c hhh chh c hhh c ch c hhh cch c hh h oopq     what are the names of p and q?     p q  a but-1-ene ethyl propanoate  b but-1-ene propyl ethanoate  c but-2-ene ethyl propanoate  d but-2-ene propyl ethanoate     38 what is an advantage of producing ethanol by fermentation of sugar compared to the catalytic  addition of steam to ethene?  a the alcohol produced is purer.  b the process is faster.  c the process uses high temperature.  d the process uses renewable raw materials.     ",
            "16": "16  \u00a9 ucles 2016 0620/23/m/j/16  39 a polymer has the formula shown.    ncch3 coohc hh     from which monomers can it be formed?    ch hc coohch3r ch hc coohch3s c hh ccooh ch3t ch hccooh ch3u     a r and s b r and t c s and u d t and u     40 which row shows a natural polymer with the same linkages as a synthetic polymer?     natural polymer synthetic polymer  a complex carbohydrate nylon  b complex carbohydrate terylene  c protein nylon  d protein terylene     ",
            "17": "17  \u00a9 ucles 2016 0620/23/m/j/16  blank page      ",
            "18": "18  \u00a9 ucles 2016 0620/23/m/j/16  blank page     ",
            "19": "19    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/23/m/j/16  blank page     ",
            "20": "20  \u00a9 ucles 2016 0620/23/m/j/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s16_qp_31.pdf": {
            "1": "cambridge international examinations cambridge international general certificate of secondary education 0620/31 may/june 2016 1 hour 15 minuteschemistry paper 3 theory (core) candidates answer on the question paper. additional materials: no additional materials are required. read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.donot write in any barcodes. answer allquestions. electronic calculators may be used.a copy of the periodic table is printed on page 20.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [ ] at the end of each question or part question. the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate. this document consists of 18printed pages and 2blank pages. [turn over 06_0620_31_2016_1.11 \u00a9 ucles 2016 *3293960889*",
            "2": "the structures of some substances containing chlorine are shown.1 cl \u2212k+cl \u2212k+ k+cl \u2212k+cl \u2212 cl \u2212k+cl \u2212k+clcl cab dec cl clclcl clclclcl clalcl clalcl c h h fhf c cf answer the following questions about these substances.(a) which substance is a diatomic molecule?(i) ... . [1] which substance represents part of an ionic structure?(ii) ... . [1] which substance is an element? explain your answer.(iii) ... . ... . [2] determine the simplest formula for substance d. (iv) ... . [1] 06_0620_31_2016_1.11 \u00a9 ucles 20162",
            "3": "the symbols for two isotopes of chlorine are shown.(b) cl  cl how do these two isotopes differ in their atomic structure?(i) ... . [1] determine the number of neutrons present in one atom of the isotope  cl. (ii) ... . [1] draw the electronic structure of a chlorine atom. show all shells and all electrons.(iii) [2] [total: 9] [turn over06_0620_31_2016_1.11 \u00a9 ucles 20163",
            "4": "a bicycle maker wants to choose a suitable material to make bicycle frames. the table shows the properties of some materials that could be used.2 cost per tonne in $ / tonneresistance to corrosiondensity in g / cm3relative strengthmaterial 1500 very good 2.7 8 aluminium 450 poor 7.9 21 iron 600 very good 7.9 24 stainless steel 15000 very good 4.5 27 titanium 1300 good 7.1 14 zinc which material is the most suitable for making the bicycle frame? explain your answer using information from the table.(a) ...  ...  ...  ...  [3] aluminium is extracted from aluminium oxide by electrolysis.(b) state the name of the main ore of aluminium.(i) ... . [1] suggest why aluminium is extracted by electrolysis and notby reduction with carbon. (ii) ... . [1] molten aluminium oxide is electrolysed using graphite electrodes. predict the products of this electrolysis at(iii) the positive electrode (anode), .. the negative electrode (cathode).  [2] 06_0620_31_2016_1.11 \u00a9 ucles 20164",
            "5": "the diagram shows the changes of state when zinc vapour is cooled slowly to room temperature.(c) zinc vapourmolten zincsolid zinccondensation freezing (solidification) explain what happens during these changes in terms of \u2022the distance between the particles, \u2022the type of motion shown by the particles. ...  ...  ...  ...  ...  [4] [total: 11] [turn over06_0620_31_2016_1.11 \u00a9 ucles 20165",
            "6": "the table shows some properties of the group i metals.3 boiling point /\u00ba cmelting point /\u00ba cdensity in g / cm3metal 1342 181 0.53 lithium 883 98 sodium 760 63 0.86 potassium 686 39 1.53 rubidium 669 29 caesium describe the trend in boiling points of the group i metals.(i) (a) ... . [1] predict the density of caesium.(ii) ... . [1] deduce the state of caesium at 20 \u00bac. explain your answer.(iii) ... . ... . [2] complete the word equation for the reaction of rubidium with water.(b) [2]rubidium + water \u2192. + . 06_0620_31_2016_1.11 \u00a9 ucles 20166",
            "7": "the dye, indigotin, is formed when compound fis exposed to air. the structure of compound fis shown below.(c) cnc ccc cc c ho\u2013 na+ hhh h h complete the table and calculate the relative molecular mass of compound f. atomic mass number of atoms type of atom 8 12 96 12 8 carbon hydrogen 1 14 14 14 1 nitrogen 1 16 16 16 1 oxygen sodium relative molecular mass =.. [2] [turn over06_0620_31_2016_1.11 \u00a9 ucles 20167",
            "8": "three dye mixtures, j,kandl, were spotted onto a piece of chromatography paper. three pure dyes, x,yandz, were also spotted onto the same piece of paper.(d) the diagram shows the results of this chromatography. jklxyz suggest why the base line was drawn in pencil and notin ink. (i) ... . [1] which dye mixture, j,korl, contains a dye which did notmove during this chromatography?(ii) ... . [1] which dye mixture, j,korl, contains both dye xand dye y? (iii) ... . [1] which dye mixture, j,korl, does notcontain dye z? (iv) ... . [1] [total: 12] 06_0620_31_2016_1.11 \u00a9 ucles 20168",
            "9": "the structures of some organic compounds are shown.4 ccp hh hhhhhh hh cc ccc hh hcq h h hch c hh hcr h h hc h s c hh hct h h hc hh hch h hch o hc hh hch h hch o hch hu which twoof these compounds are alcohols? explain your answer.(i) (a) ... . ... . [2] which twoof these compounds are saturated hydrocarbons? (ii) ... . [1] methanol and ethanol are alcohols in the same homologous series. complete the following sentence about a homologous series using words from the list.(b) elements compounds chemical alcohols physical mixtures functional [3]a homologous series is a family of similar .. with similar .. properties due to the same .. group. [turn over06_0620_31_2016_1.11 \u00a9 ucles 20169",
            "10": "ethene is an alkene.(c) draw the structure of ethene showing all atoms and all bonds.(i) [1] describe how aqueous bromine is used to show that ethene is an unsaturated compound.(ii) ... . ... . [2] ethene is manufactured by cracking. state the conditions needed for cracking.(iii) ... . [1] complete the chemical equation for the cracking of hexadecane, c16h34, to form propene and one other hydrocarbon.(iv) [1]c16h34\u2192c3h6+ . [total: 11] 06_0620_31_2016_1.11 \u00a9 ucles 201610",
            "11": "the group vii elements are called the halogens.5 describe the trends in\u2022 the physical properties of the halogens,\u2022 the reactivity of halogens with other halide ions.include a relevant word equation in your answer.(a) ...  ...  ...  ...  ...  ...  ...  [5] iodine reacts with hot concentrated nitric acid.(b) i 2  10hno3  2hio3  4h2o  10no2 explain why this reaction could have an adverse effect on health if not carried out in a fume cupboard.(i) ... . ... . [2] nitric acid is strongly acidic. which one of the following ph values represents a strongly acidic solution?put a ring around the correct answer.(ii) ph 13d ph 9c ph 7b ph 1a [1] [turn over 06_0620_31_2016_1.11 \u00a9 ucles 201611",
            "12": "nitric acid reacts with zinc oxide. state the names of the products of this reaction.(iii) [2] and  [total: 10] ammonia is manufactured by the reaction of nitrogen with hydrogen in the presence of a catalyst.6 what is the purpose of a catalyst?(a) ...  [1] the reaction is reversible. complete the equation below by adding the sign for a reversible reaction.(b) 2nh3 n2+3 h2 [1] the energy level diagram for this reaction is shown. is this reaction exothermic or endothermic?give a reason for your answer.(c) energyn2 + 3h2 2nh3 ...  ...  [1] 06_0620_31_2016_1.11 \u00a9 ucles 201612",
            "13": "the graph shows how the percentage yield of ammonia changes with temperature when the pressure is kept constant.(d) 100 80604020 0 0 100 200 300 400 temperature  / \u00b0c500 600 700% yield of ammonia describe how the percentage yield of ammonia changes with temperature.(i) ... . [1] determine the percentage yield of ammonia at 350 \u00bac.(ii) ... . [1] describe a test for ammonia.(e) test... .. result ... ... [2] [turn over06_0620_31_2016_1.11 \u00a9 ucles 201613",
            "14": "ammonia is a weak base. describe how you would measure the ph of an aqueous solution of a weak base using universal indicator.(f) ...  ...  [2] complete the chemical equation for the reaction of ammonia with chlorine.(g) [2]nh3+3 c l2\u2192n2+ ..hc l [total: 11] calcium carbonate reacts with dilute hydrochloric acid.7 caco3(s) + 2hc l(aq)\u2192cac l2(aq) + co2(g) + h2o(i) a student investigated this reaction by measuring the volume of carbon dioxide released every minute at constant temperature. draw a diagram of the apparatus that the student could use to investigate this reaction.(a) [2] 06_0620_31_2016_1.11 \u00a9 ucles 201614",
            "15": "the graph shows the results of this reaction using three samples of calcium carbonate of the same mass: large pieces, medium-sized pieces and small pieces.(b) 50 40302010 0 0 50 100 150 200 time  / s250 300 350volume of carbon dioxide/  cm3small medium large which sample, large, medium or small pieces, gave the fastest initial rate of reaction? use the graph to explain your answer.(i) ... . ... . [2] the experiment was repeated using powdered calcium carbonate of the same mass. draw a line on the grid above to show how the volume of carbon dioxide changes with time for this experiment. [2](ii) at what time was the reaction just complete when small pieces of calcium carbonate were used?(iii) ... . [1] [turn over06_0620_31_2016_1.11 \u00a9 ucles 201615",
            "16": "when calcium carbonate is heated strongly, calcium oxide is formed.(c) give one use of calcium oxide. (i) ... . [1] what type of oxide is calcium oxide? explain your answer.(ii) ... . ... . [2] [total: 10] a teacher passed hydrogen gas over hot copper (ii)oxide. 8 cuo(s) + h2(g)\u2192cu(s) + h2o(g) which substance is reduced in this reaction?explain your answer.(a) ...  ...  [2] 06_0620_31_2016_1.11 \u00a9 ucles 201616",
            "17": "the diagram shows the apparatus used.(b) dry hydrogen gas copper( ii) oxide wate rice bath the hydrogen was passed over the hot copper (ii)oxide until the reaction was complete. as the experiment proceeds, suggest what happens to the mass of copper (ii)oxide. (i) ... . [1] suggest why electrical heating is used in this experiment and nota bunsen burner. (ii) ... . [1] describe the chemical test for the presence of water.(iii) test.. result ... [2] [total: 6] [turn over06_0620_31_2016_1.11 \u00a9 ucles 201617",
            "18": "blank page 06_0620_31_2016_1.11 \u00a9 ucles 201618",
            "19": "blank page 06_0620_31_2016_1.11 \u00a9 ucles 201619",
            "20": "groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013 to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridg e international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www .cie.org.uk after the live examination series. 06_0620_31_2016_1.11 \u00a9 ucles 201620"
        },
        "0620_s16_qp_32.pdf": {
            "1": "cambridge international examinations cambridge international general certificate of secondary education 0620/32 may/june 2016 1 hour 15 minuteschemistry paper 3 theory (core) candidates answer on the question paper. additional materials: no additional materials are required. read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.donot write in any barcodes. answer allquestions. electronic calculators may be used.a copy of the periodic table is printed on page 20.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [ ] at the end of each question or part question. the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate. this document consists of 19printed pages and 1blank page. [turn over 06_0620_32_2016_1.12 \u00a9 ucles 2016 *0963380272*",
            "2": "the structures of some substances containing phosphorus are shown.1 p h hhac b deph4+i\u2013ph4+i\u2013 ph4+i\u2013 na+na+ na+p3\u2013na+na+ na+p3\u2013 na+na+na+ p3\u2013ph4+i\u2013i\u2013ph4+i\u2013ph4+p pp p o oo o oop ppp answer the following questions about these substances.(a) which twoof these substances are ionic? (i) [1] ... and ... which one of these substances is an element? explain your answer.(ii) ... . ... . [2] determine the simplest formula for substance d. (iii) ... . [1] 06_0620_32_2016_1.12 \u00a9 ucles 20162",
            "3": "phosphorus has one naturally occurring isotope.(b) determine the number of neutrons present in one atom of the isotope  p. (i) ... . [1] how many electrons are there in the outer shell of one phosphorus atom?(ii) ... . [1] determine the total number of electrons present in a phosphorus molecule, p4. (iii) ... . [1] what type of oxide is phosphorus (v)oxide? explain your answer.(c) ...  ...  [2] [total: 9] [turn over06_0620_32_2016_1.12 \u00a9 ucles 20163",
            "4": "the table describes the ease of reduction of some metal oxides with carbon.(a)2 ease of reduction on heating metal oxide moderate heating at 200 \u00b0c needed lead oxide high temperature at 750 \u00b0c needed nickel oxide very high temperatures above 1700 \u00b0c needed titanium oxide very high temperature at 900 \u00b0c needed zinc oxide put the metals in order of their reactivity. put the least reactive metal first. least reactive most reactive [2] aluminium is extracted by the electrolysis of molten aluminium oxide. predict the products of this electrolysis at the(b) positive electrode (anode), negative electrode (cathode). [2] when iron reacts with dilute hydrochloric acid, an aqueous solution containing iron (ii)ions is formed. describe a test for iron (ii)ions.(c) test... .. result ... ... [2] iron rusts very easily.(d) complete the following sentence.(i) iron rusts in the presence of . and . . [2] 06_0620_32_2016_1.12 \u00a9 ucles 20164",
            "5": "describe one method of rust prevention and explain how it works. (ii) ... . ... . ... . [2] [total: 10] [turn over06_0620_32_2016_1.12 \u00a9 ucles 20165",
            "6": "sulfur dioxide reacts with excess oxygen to form sulfur trioxide.3 2so3(g) \u21cc o2(g) + 2so2(g) what is the meaning of the symbol \u21cc? (a) ...  [1] the energy level diagram for the reaction is shown.(b) energy2so2(g) + o2(g) 2so3(g) is this reaction exothermic or endothermic? give a reason for your answer  ...  [1] 06_0620_32_2016_1.12 \u00a9 ucles 20166",
            "7": "the graph shows how the percentage yield of sulfur trioxide changes with temperature when the pressure is kept constant.(c) 100 9590858075 100 200 300 400 temperature  / \u00b0c% yield of sulfur trioxide 500 600 describe how the percentage yield of sulfur trioxide changes with temperature.(i) ... . [1] determine the percentage yield of sulfur trioxide when the temperature is 500 \u00bac.(ii) ... . [1] describe a test for sulfur dioxide.(d) test... . result ... .. [2] give one useof sulfur dioxide. (e) ...  [1] [turn over06_0620_32_2016_1.12 \u00a9 ucles 20167",
            "8": "sulfur dioxide reacts with magnesium. 2mg + so2\u21922mgo + s which substance is reduced in this reaction?explain your answer.(f) ...  ...  [2] sulfur dioxide reacts with water to form sulfurous acid, h 2so3. sulfurous acid reacts with hydrogen sulfide to form water and sulfur. complete the chemical equation for this reaction.(g) h2so3+2 h2s\u2192.h2o+3 s [1] [total: 10] 06_0620_32_2016_1.12 \u00a9 ucles 20168",
            "9": "alkanes, alkenes and alcohols are three different homologous series of organic compounds.4 what is meant by the term homologous series ? (a) ...  ...  [2] the structures of some alkanes, alkenes and alcohols are shown below.(b) chf h h h ch o h h hchg h h hch h ch o hh hch hch hch h hh cch hh ij k cch c ch hhh h hh which twoof these compounds, f,g,h,i,jandk, are saturated hydrocarbons? explain your answer.(i) ... . ... . [3] which one of these compounds is the main constituent of natural gas? (ii) ... . [1] which twoof these compounds are alkenes? (iii) [2] .and ... why are two compounds, iandk, not hydrocarbons? (iv) ... . [1] [turn over06_0620_32_2016_1.12 \u00a9 ucles 20169",
            "10": "the table gives some information about four alcohols.(c) boiling point /\u00ba cdensity in g / cm3molecular formulaalcohol 0.793 ch4o methanol 79 0.789 c2h6o 98 0.804 c3h8o propanol 117 0.810 c4h10o butanol give the name of the alcohol with the formula c2h6o. (i) ... . [1] a student predicts that the density of the alcohols increases as the number of carbon atoms increases.does the data in the table support this prediction? explain your answer.(ii) ... . ... . ... . [1] suggest a value for the boiling point of methanol.(iii) ... . [1] 06_0620_32_2016_1.12 \u00a9 ucles 201610",
            "11": "the alcohol with the formula c2h6o burns in a limited supply of air to form carbon monoxide and water.(d) complete the chemical equation for this reaction.(i) c2h6o+2 o2\u2192.co + .h2o [2] state an adverse effect of carbon monoxide on health.(ii) ... . [1] [total: 15] [turn over06_0620_32_2016_1.12 \u00a9 ucles 201611",
            "12": "chlorine, bromine and iodine are halogens.5 the melting point of bromine is \u20137 \u00bac. the boiling point of bromine is +59 \u00bac.deduce the state of bromine at +6 \u00bac. explain your answer.(a) ...  ...  [2] complete the word equation for the reaction of chlorine with potassium iodide. chlorine + potassium iodide \u2192... + .. [2](i) (b) suggest why iodine does notreact with aqueous potassium bromide. (ii) ... . ... . [1] the structure of the dye lithol fast yellow is shown.(c) cc ccoo cc cl clh h n h hhc hh nhn hoo n cc cc cc h complete the table and calculate the relative molecular mass of lithol fast yellow. atomic mass number of atoms type of atom 13 \u00d7 12 = 156 12 13 carbon 1 0\u00d71=1 0 1 10 hydrogen 4 \u00d7 14 = 56 14 4 nitrogen oxygen chlorine relative molecular mass = ... [2] 06_0620_32_2016_1.12 \u00a9 ucles 201612",
            "13": "chromatography is used to separate a mixture of dyes.(d) draw a cross on the diagram to show where the mixture of dyes is placed at the start of the chromatography.(i) solvent [1] suggest a suitable solvent that could be used.(ii) ... . [1] describe what you would observe as the experiment proceeds.(iii) ... . ... . [1] [total: 10] [turn over06_0620_32_2016_1.12 \u00a9 ucles 201613",
            "14": "sodium is a metal in group i of the periodic table.6 describe some physical and chemical properties of sodium. in your answer include(a) \u2022any observations about the reactions of sodium, \u2022at least one word equation. ...  ...  ...  ...  ...  ...  ...  [5] the presence of sodium in compounds can be confirmed using a flame test. describe how a flame test is carried out and give the result of the test for sodium.(b) test... . ...  result ... .. [2] aqueous sodium hydroxide is strongly alkaline.(c) which one of the following values is the ph of a strongly alkaline solution?put a ring around the correct answer.(i) ph 13d ph 7c ph 2b ph 1a [1] describe how you could use litmus to show that aqueous sodium hydroxide is alkaline.(ii) ... . ... . [2] 06_0620_32_2016_1.12 \u00a9 ucles 201614",
            "15": "sodium sulfite, na2so3, reacts with hydrochloric acid. na2so3(s) + 2hc l(aq)\u21922nac l(aq) + so2(g) + h2o(l) explain why this reaction could have an adverse effect on health if not carried out in a fume cupboard.(d) ...  ...  [2] [total: 12] [turn over06_0620_32_2016_1.12 \u00a9 ucles 201615",
            "16": "when magnesium reacts with hydrochloric acid, the products are aqueous magnesium chloride and hydrogen.7 mg(s) + 2hc l(aq)\u2192mgc l2(aq) + h2(g) a student used the apparatus shown to follow the progress of this reaction. dilute hydrochloric acid magnesium complete the diagram by putting the correct labels in the boxes. [2](a) the student conducted two experiments using the same mass of magnesium in each experiment and two different concentrations of hydrochloric acid. the hydrochloric acid was in excess. allother conditions were kept constant.the student measured the volume of hydrogen produced over a period of time. the graphshows the results.(b) 50 4540353025201510 50 0 60 120 180 240 time  / s300 360 420 480volume of hydrogen/  cm3 0.5 mol  / dm3 hc l1.0 mol  / dm3 hc l 06_0620_32_2016_1.12 \u00a9 ucles 201616",
            "17": "which concentration of hydrochloric acid gave the faster initial rate of reaction? use the graph to explain your answer.(i) ... . ... . [1] draw a curve on the graph on page 16 to show how the volume of hydrogen would change if a third experiment was carried out using 1.5 mol / dm3hydrochloric acid and the same mass of magnesium. [2](ii) give one use of hydrogen. (c) ...  [1] explosions have occasionally been reported where tiny particles of metal dust escape into the air. explain why metal dust can form an explosive mixture with air.(d) ...  ...  [1] [total: 7] [turn over06_0620_32_2016_1.12 \u00a9 ucles 201617",
            "18": "solder is an alloy of lead and tin.8 what is the meaning of the term alloy ? (a) ...  [1] state the name of another alloy.(b) ...  [1] a student heated a piece of solder carefully. the diagram shows what happens to the solder.(c) at the start after 2 minutessolder solder iron plate use the kinetic particle theory to describe and explain what happens to the solder as it changes state. ...  ...  ...  ...  ...  [4] when heated above 1744 \u00b0c, lead forms a vapour. describe a general property of a vapour (gas) which is not shown by a solid.(d) ...  [1] [total: 7] 06_0620_32_2016_1.12 \u00a9 ucles 201618",
            "19": "blank page [turn over06_0620_32_2016_1.12 \u00a9 ucles 201619",
            "20": "groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013 to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridg e international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www .cie.org.uk after the live examination series. 06_0620_32_2016_1.12 \u00a9 ucles 201620"
        },
        "0620_s16_qp_33.pdf": {
            "1": "cambridge international examinations cambridge international general certificate of secondary education 0620/33 may/june 2016 1 hour 15 minuteschemistry paper 3 theory (core) candidates answer on the question paper. additional materials: no additional materials are required. read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.donot write in any barcodes. answer allquestions. electronic calculators may be used.a copy of the periodic table is printed on page 20.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [ ] at the end of each question or part question. the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate. this document consists of 19printed pages and 1blank page. [turn over 06_0620_33_2016_1.10 \u00a9 ucles 2016 *6622432628*",
            "2": "the structures of some substances containing carbon are shown.1 c ch hh h ca2+c22\u2013c22\u2013c22\u2013 c22\u2013c22\u2013c22\u2013 ca2+ca2+ca2+ca2+ca2+ c ccc cc c cc cc ccccc ccc c c cc ccc cc c cc cc ccccc ccc c c c c cc cc c cc cc cc cc c cc cc cc c cccc cc ccccc c cccc ccc cccccab dec cccch h h hhclcl cl clclc answer the following questions about these substances. which twosubstances have giant covalent structures? (i) (a) [1] ... and. which substance decolourises aqueous bromine?(ii) ... . [1] which substance is most likely to be a gas at room temperature and pressure?(iii) ... . [1] which substance is a hydrocarbon?(iv) ... . [1] determine the simplest formula for substance d. (v) ... . [1] 06_0620_33_2016_1.10 \u00a9 ucles 20162",
            "3": "two isotopes of carbon are  c and  c. (b) how do these two isotopes differ in their atomic structure?(i) ... . [1] determine the number of neutrons present in one atom of the isotope  c. (ii) ... . [1] [total: 7] [turn over06_0620_33_2016_1.10 \u00a9 ucles 20163",
            "4": "this question is about metals.2 the table shows some properties of the metals, r,s,tandu. (a) melting point /\u00b0 cdensity in g/c m3relative heat conductivityrelative electrical conductivitymetal 660 2.7 11.8 4.3 r 1535 7.9 4.2 1.2 s 1083 8.9 22.3 6.2 t 420 7.1 12.4 4.1 u which metal would be best to make the base of a pan for cooking food? use the information in the table to explain your answer  ...  ...  ...  [3] zinc chloride can be made by reacting excess zinc with hydrochloric acid. suggest how the excess zinc can be removed from the reaction mixture.(b) ...  [1] zinc can be obtained from molten zinc chloride by electrolysis.(c) what is meant by the term electrolysis ? (i) ... . ... . [2] 06_0620_33_2016_1.10 \u00a9 ucles 20164",
            "5": "draw a labelled diagram of the apparatus that could be used to electrolyse molten zinc chloride.(ii) [3] give one advantage of recycling metals. (d) ...  [1] [total: 10] [turn over06_0620_33_2016_1.10 \u00a9 ucles 20165",
            "6": "the table gives some information about the halogens.3 boiling point / \u00b0c melting point / \u00b0c colour element \u201335 \u2013101 light green chlorine +59 \u20137 red-brown bromine +184 +114 grey-black iodine +337 +302 astatine predict the colour of astatine.(i) (a) ... . [1] describe the trend in the boiling points of the halogens.(ii) ... . [1] deduce the state of chlorine at \u201350 \u00b0c. explain your answer.(iii) ... . ... . [2] complete the word equation for the reaction of bromine with aqueous potassium astatide.(i) (b) bromine + potassium astatide \u2192.. + . [2] suggest why bromine does notreact with aqueous potassium chloride. (ii) ... . ... . [1] 06_0620_33_2016_1.10 \u00a9 ucles 20166",
            "7": "compound xis used to prepare the dye methyl orange. the structure of compound xis shown.(c) cc cccn+nc l \u2013c so o hh hh o h complete the table and calculate the relative molecular mass of compound x. atomic mass number of atoms type of atom 6 \u00d7 12 = 72 12 6 carbon 5\u00d71=5 1 5 hydrogen 2 \u00d7 14 = 28 14 2 nitrogen 1 \u00d7 32 = 32 32 1 sulfur oxygen chlorine relative molecular mass = ... [2] describe how you could use methyl orange to distinguish between solutions of hydrochloric acid and sodium hydroxide.(d) ...  ...  [2] [turn over06_0620_33_2016_1.10 \u00a9 ucles 20167",
            "8": "methyl orange and congo red are dyes. a mixture of methyl orange and congo red can be separated by chromatography. draw a labelled diagram to show how the apparatus is arranged to carry out chromatography.(e) [3] [total: 14] 06_0620_33_2016_1.10 \u00a9 ucles 20168",
            "9": "blank page turn over to continue [turn over06_0620_33_2016_1.10 \u00a9 ucles 20169",
            "10": "petroleum is a mixture of hydrocarbons.4 what is the meaning of the term hydrocarbon ? (a) ...  [1] petroleum can be separated into different fractions by fractional distillation. the diagram shows a fractionating column. the fractions are shown by letters.(b) petroleuma b c d e ffurnace describe how fractional distillation is used to separate the petroleum into fractions. in your answer refer to\u2022 changes of state,\u2022 differences in boiling points  ...  ...  ...  ...  ...  ...  [5] 06_0620_33_2016_1.10 \u00a9 ucles 201610",
            "11": "the properties of the fractions are shown in the table.(c) boiling range /\u00b0 cpercentage by mass of the fractionnumber of carbon atomsfraction less than 40 3 1\u20134 a 40 \u2013 160 14 4\u20131 0 b 160 \u2013 250 13 10 \u2013 16 c 250 \u2013 300 9 16 \u2013 20 d 300 \u2013 350 9 20 \u2013 25 e more than 350 more than 25 f total = 100 describe how the number of carbon atoms affects the boiling range.(i) ... . ... . [1] determine the percentage by mass of fraction fin this sample of petroleum. (ii) ... . [1] which one of the fractions is mainly gaseous at 25 \u00b0c? (iii) ... . [1] fraction fis the residue. it contains bitumen. give one use of bitumen.(iv) ... . [1] fraction ccan be cracked to form alkenes. (d) describe one condition required for cracking. (i) ... . [1] [turn over06_0620_33_2016_1.10 \u00a9 ucles 201611",
            "12": "complete the chemical equation for the cracking of dodecane, c12h26, to form heptane, c7h16, and one other hydrocarbon. c12h26\u2192c7h16+ . [1](ii) [total: 12] iron is a transition element.5 describe the physical and chemical properties of iron.(a) ...  ...  ...  ...  ...  [5] iron carbonyl, fe(co)5, is a covalent liquid. (b) suggest twophysical properties of iron carbonyl. (i) ... . ... . [2] when heated above 200 \u00b0c, iron carbonyl undergoes thermal decomposition. fe(co)5(i)\u2192fe(s) + 5co(g) explain why this reaction could have an adverse effect on health if not carried out in a fume cupboard.(ii) ... . ... . [2] [total: 9] 06_0620_33_2016_1.10 \u00a9 ucles 201612",
            "13": "ethanol can be manufactured by reacting ethene with steam.6 c2h4(g) + h2o(g)\u21ccc2h5oh(g) what is the meaning of the symbol \u21cc? (a) ...  [1] state twoconditions needed for this reaction. (b) ...  ...  [2] the energy level diagram for this reaction is shown.(c) energyc2h4(g) + h2o(g) c2h5oh(g) is this reaction exothermic or endothermic? give a reason for your answer  ...  [2] [turn over 06_0620_33_2016_1.10 \u00a9 ucles 201613",
            "14": "the graph below shows how the percentage yield of ethanol changes with temperature when the pressure is kept constant.(d) 50 40302010 100 200 300 temperature  / \u00b0c% yield of ethanol 400 describe how the percentage yield changes with temperature.(i) ... . ... . [1] determine the percentage yield when the temperature is 350 \u00b0c.(ii) ... . [1] complete the structure of ethanol, c2h5oh, to show all atoms and all bonds. (i) (e) h hc h [1] give one use of ethanol. (ii) ... . [1] 06_0620_33_2016_1.10 \u00a9 ucles 201614",
            "15": "complete the chemical equation for the complete combustion of ethanol. c2h5o h+3 o2\u2192co2+ h2o [2](iii) [total: 11] [turn over06_0620_33_2016_1.10 \u00a9 ucles 201615",
            "16": "a student investigated the reaction between zinc and sulfuric acid at 20 \u00b0c using the apparatus shown. the zinc was in excess.7 zincgas syringesulfuric acid what should the student do to start the reaction?(a) ...  [1] the graph shows the volume of hydrogen released as the reaction proceeds.(b) 50 40302010 0 0246 time  / minutes8 1 01 21 4volume of hydrogen/  cm3 06_0620_33_2016_1.10 \u00a9 ucles 201616",
            "17": "explain why the volume of gas stays the same after 10 minutes.(i) ... . [1] how long did it take for the first 20 cm3of gas to be collected? (ii) ... . [1] the student repeated the experiment at 30 \u00b0c. all other conditions remained the same. draw the shape of the line on the grid on page 16 when the reaction was carried out at 30 \u00b0c. [2](iii) the student repeated the experiment using zinc powder instead of small pieces of zinc. describe and explain how the rate of reaction differs when zinc powder is used.(c) ...  ...  [2] sulfuric acid is a compound.(d) what is the meaning of the term compound ? (i) ... . ... . [1] sulfur is used to make sulfuric acid. give one source of sulfur.(ii) ... . [1] sulfur is oxidised by air to form sulfur dioxide. give one use of sulfur dioxide.(iii) ... . [1] [total: 10] [turn over06_0620_33_2016_1.10 \u00a9 ucles 201617",
            "18": "the graph shows how increasing the pressure at constant temperature changes the volume of a fixed mass of carbon dioxide gas.8 volume pressure describe how the volume of gas changes with pressure.(a) ...  ...  ...  [2] what happens to the average distance of the molecules from each other when the pressure is decreased?(b) ...  [1] carbon dioxide can be reduced by magnesium.(c) 2mg(s) + co2(g)\u21922mgo(s) + c(s) use the information in the equation to show that carbon dioxide gets reduced.(i) ... . [1] which one of these processes does notproduce carbon dioxide? tickone box.(ii) respiration reaction of an acid with a metal oxide reaction of an acid with a carbonate thermal decomposition of limestone [1] 06_0620_33_2016_1.10 \u00a9 ucles 201618",
            "19": "give twoproblems caused by increasing the amount of carbon dioxide in the atmosphere.(iii) ... . ... . ... . [2] [total: 7] [turn over06_0620_33_2016_1.10 \u00a9 ucles 201619",
            "20": "groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013 to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridg e international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www .cie.org.uk after the live examination series. 06_0620_33_2016_1.10 \u00a9 ucles 201620"
        },
        "0620_s16_qp_41.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/41   paper 4 theory (extended) may/june 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib16 06_0620_41/4rp\u00a9 ucles 2016 *4054381962* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/41/m/j/16 \u00a9 ucles 20161  protons, neutrons and electrons are subatomic particles.  (a)  complete the table to show the relative mass and relative charge of a proton, a neutron and an  electron. particle relative mass relative charge proton neutron electron18401 [3]  (b)  bromine has two isotopes.  (i)  define the term isotope .   .   ...   [2]  (ii)  explain why the two isotopes of bromine have the same chemical properties.   .   ...   [2]  (c)  the table shows the number of protons, neutrons and electrons in some atoms and ions.   complete the table. particlenumber of protonsnumber of neutronsnumber of electrons 7li3 - 34 2s16 19 22 18 [5] [total: 12]",
            "3": "3 0620/41/m/j/16 \u00a9 ucles 2016 [turn over2  period 3 contains the elements sodium to argon. this question asks about the chemistry of each of  the period 3 elements or their compounds.  (a)  sodium nitrate is a white crystalline solid. when heated it melts and the following reaction occurs. 2nano 3(l)  \u2192  2nano2(l)  +  o2(g)   a 3.40 g sample of sodium nitrate is heated.   calculate the  \u2022  number of moles of nano3 used, .. mol  \u2022  number of moles of o2 formed, .. mol  \u2022  volume of o2 formed, in dm3 (measured at r.t.p.). .. dm3 [3]  (b)  magnesium reacts slowly with warm water to form a base, magnesium hydroxide.  (i)  explain what is meant by the term base.   ...   [1]  (ii)  write a chemical equation for the reaction between magnesium and warm water.   ...   [2]",
            "4": "4 0620/41/m/j/16 \u00a9 ucles 2016 (c)  aluminium oxide is amphoteric. it is insoluble in water.   describe experiments to show that aluminium oxide is amphoteric.            ..   [3]  (d)  silicon( iv) oxide has a giant structure.  (i)  name the type of bonding in silicon( iv) oxide.   ...   [1]  (ii)  give two physical properties of silicon( iv) oxide.   .   ...   [2]  (e)  calcium phosphate is used in fertilisers. the bonding in calcium phosphate is ionic.  calcium phosphate contains the phosphate ion, po43\u2013.  (i)  what is ionic bonding?   .   ...   [2]  (ii)  deduce the formula of calcium phosphate.   ...   [1]",
            "5": "5 0620/41/m/j/16 \u00a9 ucles 2016 [turn over (f)  sulfur tetrafluoride, sf4, can be made by combining gaseous sulfur with fluorine. s(g)  +  2f2(g)  \u2192  sf4(g)   the reaction is exothermic.  (i)  complete the energy level diagram for this reaction. include an arrow which clearly shows  the energy change during the reaction. energys(g)  +  2f2(g) [3]  (ii)  during the reaction the amount of energy given out is 780 kj / mol.   the f\u2013f bond energy is 160 kj / mol.   use this information to determine the bond energy, in kj / mol, of one s\u2013f bond in sf4. s  + f\u2192f f f fs ff f .. kj / mol  [3] ",
            "6": "6 0620/41/m/j/16 \u00a9 ucles 2016 (g)  chlorine and compounds of chlorine are important in water treatment and in laboratory testing  for water.  (i)  chlorine is added to water to make the water safe to drink.   explain why adding chlorine makes water safe to drink.   ...   [1]  (ii)  a compound of chlorine is used in the laboratory to test for the presence of water.   name the compound of chlorine used in this test and describe the colour change seen in  a positive result of this test.   name of compound  .   colour change from ...  to   .. . [3]  (h)  argon is an unreactive noble gas.  (i)  explain why argon is unreactive.   ...   [1]  (ii)  give one use of argon.   ...   [1] [total: 27]",
            "7": "7 0620/41/m/j/16 \u00a9 ucles 2016 [turn overquestion 3 starts on the next page.",
            "8": "8 0620/41/m/j/16 \u00a9 ucles 20163  when aqueous sodium thiosulfate and dilute hydrochloric acid are mixed, a precipitate of insoluble  sulfur is produced. this makes the mixture difficult to see through. na2s2o3(aq)  +  2hcl (aq)  \u2192  s(s)  +  2nacl (aq)  +  h2o(l)  +  so2(g)   the time taken for the cross to disappear from view is measured.   a student adds the following volumes of aqueous sodium thiosulfate, dilute hydrochloric acid and distilled water to the conical flask.   the time taken for the formation of the precipitate of sulfur to make the cross disappear from view is recorded. experiment numbervolume of sodium thiosulfate / cm3volume of  hydrochloric acid / cm3volume of distilled water / cm3time taken for  cross to disappear  from view / s 1 10 10 40 56 2 20 10 30 28 3  (a)  state the order in which the aqueous sodium thiosulfate, hydrochloric acid and distilled water should be added to the flask.      ..   [1]",
            "9": "9 0620/41/m/j/16 \u00a9 ucles 2016 [turn over (b)  in experiment 3 the student wanted the sodium thiosulfate to be double the concentration used  in experiment 2.  (i)  complete the table to show the volumes which should be used and the expected time  taken for the cross to disappear from view in experiment 3. [2]  (ii)  use collision theory to explain why increasing the concentration of sodium thiosulfate would change the rate of reaction.   .   .   .   ...   [2]  (c)  the student repeated experiment 1 at a higher temperature.   use collision theory to explain why the rate of reaction would increase.            ..   [3] [total: 8]",
            "10": "10 0620/41/m/j/16 \u00a9 ucles 20164  electroplating steel objects with silver involves a three-step process.  step 1   a coating of copper is applied to the object.  step 2   a coating of nickel is applied to the object.  step 3   the coating of silver is applied to the object.  (a)  a diagram of the apparatus used for step 1 is shown. + \u2013 copper (anode) steel object (cathode) aqueous copper( ii) sulfate electrolyte  (i)  the chemical process taking place on the surface of the object is cu2+(aq)  +  2e\u2013  \u2192  cu(s)   explain whether this process is oxidation or reduction.   .   ...   [1]  (ii)  explain why the concentration of copper ions in the electrolyte remains constant throughout  step 1.   .   .   ...   [2]",
            "11": "11 0620/41/m/j/16 \u00a9 ucles 2016 [turn over (b)  give two changes which would be needed in order to coat nickel onto the object in step 2.            ..   [2]  (c)  copper, nickel and silver are transition elements.   typical physical properties of transition elements are a high density and a high melting point.   give three different properties of transition metals which are not typical of other metals.         ..   [3] [total: 8]",
            "12": "12 0620/41/m/j/16 \u00a9 ucles 20165  sulfuric acid is produced by the contact process. the steps of the contact process are shown. starting materialstep 1sulfur dioxidesulfur trioxidesulfuric acidoleumstep 2 step 3 step 4  (a)  sulfur is a common starting material for the contact process.   name a source of sulfur.   ..   [1]  (b)  describe step 2, giving reaction conditions and a chemical equation. reference to reaction  rate and yield is not required.                     ..   [5]  (c)  step 3 involves adding sulfur trioxide to concentrated sulfuric acid to form oleum.   complete the chemical equation for this reaction. h2so4  +  so3  \u2192   [1]",
            "13": "13 0620/41/m/j/16 \u00a9 ucles 2016 [turn over (d)  dilute sulfuric acid is a typical acid.   a student adds excess dilute sulfuric acid to a sample of solid copper( ii) carbonate in a  test-tube.  (i)  give three observations the student would make.   .   .   ...   [2]  (ii)  give the names of all products formed.   .   ...   [1]  (e)  concentrated sulfuric acid has different properties to dilute sulfuric acid.   when concentrated sulfuric acid is added to glucose, c6h12o6, steam is given off and a black  solid is formed.  (i)  name the black solid.   ...   [1]  (ii)  what type of reaction has occurred?   ...   [1] [total: 12]",
            "14": "14 0620/41/m/j/16 \u00a9 ucles 20166  petroleum is a source of many important chemicals.  (a)  name two industrial processes which must take place to produce alkenes from petroleum.      ..   [2]  (b)  ethene, ch2=ch2, and propene, ch2=chch3, can both be converted into polymers.  (i)  what type of polymerisation takes place when ethene forms a polymer?   ...   [1]  (ii)  what is the empirical formula of the polymer formed from ethene?   ...   [1]  (iii)  propene has the structural formula ch2=chch3.   draw two repeat units of the polymer made from propene. [2]  (c)  ethene will react with steam to form ethanol.   propene will react with steam to form two isomers, both of which are alcohols.   suggest the structures of these alcohols. [2]",
            "15": "15 0620/41/m/j/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (d)  esters are organic chemicals noted for their characteristic smells. ethanoic acid and methanol  will react to form an ester.  (i)  name the catalyst needed to form an ester from ethanoic acid and methanol.   ...   [1]  (ii)  name the ester formed when ethanoic acid reacts with methanol.   ...   [1]  (iii)  draw the structure of the ester formed when ethanoic acid reacts with methanol. show all bonds. [2]  (iv)  give the name of a polyester.   ...   [1] [total: 13]",
            "16": "16 0620/41/m/j/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi vii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silico n 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn coperniciu m \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arseni c 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorin e 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samariu m 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrencium \u2013"
        },
        "0620_s16_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/42   paper 4 theory (extended) may/june 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 12 printed pages. [turn overib16 06_0620_42/3rp\u00a9 ucles 2016 *3291778503* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/m/j/16 \u00a9 ucles 20161 (a)  for each of the following, give the name of an element from period 2 (lithium to neon), which  matches the description.   elements may be used once, more than once or not at all.  (i)  an element which is gaseous at room temperature and pressure   ...   [1]  (ii)  an element which forms an oxide that is a reactant in photosynthesis   ...   [1]  (iii)  an element that is a product of photosynthesis   ...   [1]  (iv)  an element that makes up approximately 78% by volume of the air   ...   [1]  (v)  an element which has atoms with a full outer shell of electrons   ...   [1]  (vi)  an element which exists as both diamond and graphite   ...   [1]  (vii)  an element that reacts vigorously with cold water   ...   [1]  (viii)  a soft metallic element which is stored in oil   ...   [1]  (b)  give the formula of a compound that contains  (i)  only boron and oxygen,     [1]  (ii)  only lithium and nitrogen.  ..   [1] [total: 10]",
            "3": "3 0620/42/m/j/16 \u00a9 ucles 2016 [turn over2 (a) (i)  define the term atomic number .   ...   [1]  (ii)  define the term nucleon number .   .   ...   [2]  (b)  the table shows the number of protons, neutrons and electrons in some atoms or ions.   complete the table. the first line is given as an example. particlenumber of protonsnumber of electronsnumber of neutronssymbol or formula a 6 6 6 c12 6 b 12 12 12 c 8-2o16 8 d 11 10 13 [6] [total: 9]",
            "4": "4 0620/42/m/j/16 \u00a9 ucles 20163  gallium is a metallic element in group iii. it has similar properties to aluminium.  (a) (i)  describe the structure and bonding in a metallic element.   you should include a labelled diagram in your answer.   .   ...   [3]  (ii)  explain why metallic elements such as gallium are good conductors of electricity.   ...   [1]  (b)  give the formula of   gallium( iii) chloride,  ..   gallium( iii) sulfate.   [2]  (c)  gallium( iii) oxide, ga2o3, is amphoteric.  (i)  write the chemical equation for the reaction between gallium( iii) oxide and dilute nitric  acid to form a salt and water only.   ...   [2]  (ii)  the reaction between gallium( iii) oxide and sodium hydroxide solution forms only water  and a salt containing the negative ion ga2o42\u2013.   write the chemical equation for this reaction.   ...   [2]  (d)  alloys of gallium and other elements are often more useful than the metallic element itself.   suggest two reasons why alloys of gallium are more useful than the metallic element.      ..   [2] [total: 12]",
            "5": "5 0620/42/m/j/16 \u00a9 ucles 2016 [turn over4  hydrogen can be manufactured from methane by steam reforming. ch4(g)  +  h2o(g)    co(g)  +  3h2(g)   the reaction is carried out using a nickel catalyst at temperatures between 700 \u00b0c and 1100 \u00b0c and  using a pressure of one atmosphere.   the forward reaction is endothermic.  (a)  what is meant by the term catalyst?      ..   [2]  (b)  suggest two reasons why a temperature lower than 700 \u00b0c is not used.      ..   [2]  (c)  suggest one advantage of using a pressure greater than one atmosphere.   ..   [1]  (d)  suggest one disadvantage of using a pressure greater than one atmosphere.   ..   [1]  (e)  hydrogen can also be manufactured by electrolysis. the electrolyte is concentrated aqueous  sodium chloride. the electrodes are inert.   the products of electrolysis are hydrogen, chlorine and sodium hydroxide.  (i)  define the term electrolysis .   .   ...   [2]  (ii)  name a substance that can be used as the inert electrodes.   ...   [1]  (iii)  write an ionic half-equation for the reaction in which hydrogen is produced.   ...   [1]  (iv)  where is hydrogen produced in the electrolytic cell?   ...   [1]",
            "6": "6 0620/42/m/j/16 \u00a9 ucles 2016 (v)  describe a test for chlorine.   test  ..     result  ... [2]  (f)  the electrolysis of concentrated aqueous sodium chloride can be represented by the following  word equation. sodium chloride  +  water  \u2192  sodium hydroxide  +  hydrogen  +  chlorine   construct a chemical equation to represent this reaction. do not include state symbols.   ..   [2]  (g)  state one use of  chlorine,  .   sodium hydroxide,  .  hydrogen.  ... [3] [total: 18]",
            "7": "7 0620/42/m/j/16 \u00a9 ucles 2016 [turn over5 (a)  hydrocarbons are compounds which contain hydrogen and carbon only.  \u2022  10 cm3 of a gaseous hydrocarbon, cxhy, are burned in 100 cm3 of oxygen, which is an  excess of oxygen.  \u2022  after cooling to room temperature and pressure, there is 25 cm3 of unreacted oxygen,  50 cm3 of carbon dioxide and some liquid water.   all volumes are measured under the same conditions of temperature and pressure.  (i)  what is meant by an excess of oxygen?   ...   [1]  (ii)  what was the volume of oxygen that reacted with the hydrocarbon?   ...   [1]  (iii)  complete the table below to express the smallest whole number ratio of volume of hydrocarbon reacted:volume of oxygen reacted:volume of carbon dioxide produced volume of hydrocarbon reactedvolume of oxygen reactedvolume of carbon dioxide produced smallest whole number ratio ofvolumes [1]  (iv)  use your answer to (a)(iii) to find the mole ratio in the equation below. complete the  equation and deduce the formula of the hydrocarbon. .c xhy(g)  +  .o2(g)  \u2192  .co2(g)  +  .h2o(l) formula of hydrocarbon = ... [2]",
            "8": "8 0620/42/m/j/16 \u00a9 ucles 2016 (b)  cracking is used to convert long chain alkanes into shorter chain alkanes and alkenes. alkenes  are unsaturated compounds.   decane, c10h22, can be cracked to give propene and one other product.  (i)  complete the chemical equation.  c10h22  \u2192  c3h6  +  ... [1]  (ii)  what is meant by the term unsaturated ?   ...   [1]  (iii)  describe a test to show that propene is an unsaturated compound.   test  ..  result  ... [2]  (c)  propene can be polymerised. the only product is polypropene. the equation for the  polymerisation is: nc hch3 c hh nc3h6  (i)  name the type of polymerisation that occurs.   ...   [1]  (ii)  deduce the maximum mass of polypropene that could be produced from 1 kg of propene. ... kg  [1]  (iii)  give the empirical formula of    propene,  .   polypropene.  ... [2] [total: 13]",
            "9": "9 0620/42/m/j/16 \u00a9 ucles 2016 [turn over6  zinc is extracted from an ore called zinc blende, which consists mainly of zinc sulfide, zns.  (a) (i)  the zinc sulfide in the ore is first converted into zinc oxide.   describe how zinc oxide is made from zinc sulfide.   .   ...   [1]  (ii)  write a chemical equation for the reaction in (a)(i).   ...   [2]  (b)  zinc oxide is converted into zinc. zinc oxide and coke are fed into a furnace. hot air is blown  into the bottom of the furnace.   zinc has a melting point of 420 \u00b0c and a boiling point of 907 \u00b0c. the temperature inside the  furnace is over 1000 \u00b0c.  (i)  explain how zinc oxide is converted into zinc. your answer should include details of how the heat is produced and equations for all the reactions you describe.   .   .   .   .   ...   [3]  (ii)  explain why the zinc produced inside the furnace is a gas.   ...   [1]  (iii)  state the name of the physical change for conversion of gaseous zinc into molten zinc.   ...   [1]",
            "10": "10 0620/42/m/j/16 \u00a9 ucles 2016 (c)  rusting of steel can be prevented by coating the steel with a layer of zinc.   explain, in terms of electron transfer, why steel does not rust even if the layer of zinc is  scratched so that the steel is exposed to air and water.               ..   [4]  (d)  when a sample of steel is added to dilute hydrochloric acid, an aqueous solution of  iron(ii) chloride, fec l 2, is formed.   when a sample of rust is added to dilute hydrochloric acid, an aqueous solution of   iron(iii) chloride, fec l 3, is formed.  (i)  aqueous sodium hydroxide is added to the solutions of iron( ii) chloride and  iron(iii) chloride.   complete the table below, showing the observations you would expect to make. iron(ii) chloride solution iron(iii) chloride solution aqueous sodium hydroxide [2]",
            "11": "11 0620/42/m/j/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.   solutions of iron( ii) chloride and iron( iii) chloride were added to solutions of potassium iodide  and acidified potassium manganate( vii). the results are shown in the table. iron(ii) chloride  solutioniron(iii) chloride  solution potassium iodide solutionno changesolution turns from colourless to brown acidified potassium manganate( vii) solutionsolution turns from purple to colourlessno change  (ii)  what types of substance cause potassium iodide solution to turn from colourless to  brown?   ...   [1]  (iii)  what types of substance cause acidified potassium manganate( vii) solution to turn from  purple to colourless?   ...   [1]  (iv)  which ion in iron( iii) chloride solution causes potassium iodide solution to turn from  colourless to brown?   ...   [1]  (v)  which ion in iron( ii) chloride solution causes acidified potassium manganate( vii) solution  to turn from purple to colourless?   ...   [1] [total: 18]",
            "12": "12 0620/42/m/j/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi vii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silico n 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn coperniciu m \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arseni c 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorin e 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samariu m 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrencium \u2013"
        },
        "0620_s16_qp_43.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printe d on page 16. you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/43   paper 4 theory (extended) may/june 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib16 06_0620_43/3rp\u00a9 ucles 2016 *2399434482* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/43/m/j/16 \u00a9 ucles 20161  the diagram shows a blast furnace. waste gases raw materials : coke, c iron ore, fe2o3 limestone, caco3 x y  (a)  the following equations represent reactions which take place in the blast furnace.  a c  +  o2  \u2192  co2  b caco3  \u2192  cao  +  co2  c cao  +  sio2  \u2192  casio3  d co2  +  c  \u2192  2co  e fe2o3  +  3co  \u2192  2fe  +  3co2  (i)  which reaction is used to increase the temperature inside the blast furnace? ...  [1]  (ii)  which reaction is an example of thermal decomposition? ...  [1]  (iii)  in which reaction is carbon both oxidised and reduced? ...  [1]  (iv)  which equation shows the removal of an impurity from the iron? ...  [1]  (v)  which equation shows the reaction of an acidic substance with a basic substance? ...  [1]  (b) use the diagram of the blast furnace to help you answer these questions.  (i)  what enters the blast furnace at x?   ...   [1]  (ii)  what leaves the blast furnace at y?   ...   [1]",
            "3": "3 0620/43/m/j/16 \u00a9 ucles 2016 [turn over (iii)  name two waste gases that leave the blast furnace.  1.  .  2.  . [2]  (c)  the graph shows how the malleability of iron changes as the percentage of carbon in the iron  changes. increasing percentage of carbonmalleabilityhigh low  (i)  describe how the malleability of iron changes as the percentage of carbon changes.   .   ...   [1]  (ii)  iron obtained from the blast furnace contains high levels of carbon.   explain how the amount of carbon in the iron can be decreased.   .   .   ...   [2] [total: 12]",
            "4": "4 0620/43/m/j/16 \u00a9 ucles 20162  the structures of six organic compounds are shown. h chha h hc ch hb c ch h hh ch h chch hhhch ch h hh chc d e fh ohco h chh ho hc h h h chh hhc chh hhc  (a)  give the name of f.   ..   [1]  (b)  identify two of the compounds that are members of the same homologous series.   give the general formula of this homologous series.  compounds    general formula  .. [2]  (c)  which two compounds are isomers of each other?   explain why they are isomers.  compounds    explanation      [3]  (d)  explain why b is an unsaturated hydrocarbon.         ..   [2]",
            "5": "5 0620/43/m/j/16 \u00a9 ucles 2016 [turn over (e)  describe how d is manufactured from b. give a chemical equation for the reaction.         ..   [3]  (f)  compound a forms an addition polymer.   draw two repeat units of the addition polymer formed from a. [2] [total: 13]",
            "6": "6 0620/43/m/j/16 \u00a9 ucles 20163  clean dry air contains mainly nitrogen and oxygen.  (a)  name two other gases that are in clean dry air.      ..   [2]  (b)  air often contains pollutants.   identify three common gaseous pollutants in air and state how each of these pollutants are  produced.  pollutant gas 1  ...  how it is produced  ..     pollutant gas 2  ...  how it is produced  ..     pollutant gas 3  ...  how it is produced  ..    [6] [total: 8]",
            "7": "7 0620/43/m/j/16 \u00a9 ucles 2016 [turn over4 (a)  potassium iodide is an ionic compound.  (i)  describe what happens, in terms of electron loss and gain, when a potassium atom reacts  with an iodine atom.   .   .   .   ...   [2]  (ii)  describe the structure of solid potassium iodide. you may draw a diagram.   .   .   ...   [2]  (iii)  explain why potassium iodide has a high melting point.   .   .   ...   [2]",
            "8": "8 0620/43/m/j/16 \u00a9 ucles 2016 (b)  potassium iodide and lead nitrate are both soluble. lead iodide is insoluble.  (i)  describe how a pure dry sample of lead iodide could be made from solid potassium iodide  and solid lead nitrate.   .   .   .   .   .   ...   [4]  (ii)  write an ionic equation for the formation of lead iodide, pbi2, when potassium iodide and  lead nitrate react with each other.   state symbols are not required.   ...   [2]  (c)  when chlorine gas is bubbled through an aqueous solution of potassium iodide, a redox  reaction takes place. 2i \u2013  +  c l 2  \u2192  i2  +  2cl \u2013  (i)  state the colour change expected in this reaction.   start colour  ..   end colour  ... [2]  (ii)  identify the reducing agent in this reaction. explain your answer.   .   .   ...   [2] [total: 16]",
            "9": "9 0620/43/m/j/16 \u00a9 ucles 2016 [turn over5  dilute hydrochloric acid reacts with sodium carbonate solution. 2hcl (aq)  +  na2co3(aq)  \u2192  2nacl (aq)  +  h2o(l)  +  co2(g)  (a)  explain why effervescence is seen during the reaction.      ..   [1]  (b)  dilute hydrochloric acid was titrated with sodium carbonate solution.  \u2022  10.0 cm3 of 0.100 mol / dm3 hydrochloric acid were placed in a conical flask. \t \u2022  a few drops of methyl orange indicator were added to the dilute hydrochloric acid. \t \u2022  the mixture was titrated with sodium carbonate solution. \t \u2022  16.2 cm3 of sodium carbonate solution were required to react completely with the acid.  (i)  what colour would the methyl orange indicator be in the hydrochloric acid?   ...   [1]  (ii)  calculate how many moles of hydrochloric acid were used.  mol  [1]  (iii)  use your answer to (b)(ii)  and the equation for the reaction to calculate the number of  moles of sodium carbonate that reacted.  mol  [1]  (iv)  use your answer to (b)(iii)  to calculate the concentration of the sodium carbonate solution  in mol / dm3.  mol / dm3  [2]  (c)  in another experiment, 0.020 mol of sodium carbonate were reacted with excess hydrochloric  acid.   calculate the maximum volume (at r.t.p.) of carbon dioxide gas that could be made in this  reaction.  dm3  [3] [total: 9]",
            "10": "10 0620/43/m/j/16 \u00a9 ucles 20166  concentrated ammonia solution gives off ammonia gas. concentrated hydrochloric acid gives off  hydrogen chloride gas. ammonia, nh3, and hydrogen chloride, hc l, are both colourless gases.   ammonia reacts with hydrogen chloride to make the white solid ammonium chloride.   apparatus is set up as shown. cotton wool soaked in concentrated hydrochloric acidcotton wool soaked in concentrated ammonia solution glass tubea b c d   after ten minutes a white solid forms in the tube where the gases meet.  (a) (i)  write the chemical equation for the reaction of ammonia with hydrogen chloride.   ...   [1]  (ii)  name the process by which the ammonia and hydrogen chloride gases move in the tube.   ...   [1]  (iii)  at which point, a, b, c or d, does the white solid form? explain why the white solid forms  at that point.  the solid forms at ..  explanation  .   . [3]  (iv)  the experiment was repeated at a higher temperature.   predict how the results of the experiment would be different. explain your answer.   .   .   ...   [3]",
            "11": "11 0620/43/m/j/16 \u00a9 ucles 2016 [turn over (b)  some of the white solid is removed from the tube and dissolved in water.   describe how the white solid could be tested to show it contains,  (i) ammonium ions,  test  ..   .  result  ...   . [3]  (ii) chloride ions.  test  ..   .  result  ...   . [3]  (c)  the diagram shows the electron arrangement in a molecule of ammonia, showing only outer  shell electrons. n hh h  (i)  state the type of bonding in ammonia.   ...   [1]",
            "12": "12 0620/43/m/j/16 \u00a9 ucles 2016 (ii)  hydrazine, n2h4, is another compound of nitrogen and hydrogen.   complete the diagram to show the electron arrangement in a molecule of hydrazine,  showing only outer shell electrons. n n hh hh [3]  (d)  nylon and proteins are both polymers containing nitrogen.  (i)  name the linkages found in the polymers of nylon and protein.   ...   [1]  (ii)  describe one difference in the structures of nylon and protein.   ...   [1]  (iii)  what is the general name given to the products of hydrolysis of proteins?   ...   [1]",
            "13": "13 0620/43/m/j/16 \u00a9 ucles 2016 [turn over (e)  suggest the structure of the monomer used to make the polymer shown. nh co n [1] [total: 22]",
            "14": "14 0620/43/m/j/16 \u00a9 ucles 2016blank page",
            "15": "15 0620/43/m/j/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "16": "16 0620/43/m/j/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi vii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silico n 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn coperniciu m \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arseni c 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorin e 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samariu m 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrencium \u2013"
        },
        "0620_s16_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on pages 7 and 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/51   paper 5 practical test may/june 2016  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructions cambridge international examinations cambridge international general certificate of secondary education this document consists of 8 printed pages. [turn overib16 06_0620_51/7rp\u00a9 ucles 2016 *8113146472* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/51/m/j/16 \u00a9 ucles 20161  you are going to investigate the reaction between aqueous sodium carbonate and two different  solutions of dilute hydrochloric acid labelled a and b.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out three experiments.  (a)  experiment 1   use a measuring cylinder to pour 25 cm3 of aqueous sodium carbonate into a conical flask.   add ten drops of thymolphthalein indicator to the conical flask.   fill the burette provided up to the 0.0 cm3 mark with solution a of dilute hydrochloric acid.  add solution a from the burette while swirling the flask, until the solution just changes colour.  record the burette readings in the table below.   experiment 2   empty the conical flask and rinse it with distilled water.   repeat experiment 1 using methyl orange indicator instead of thymolphthalein.   record the burette readings in the table below and complete the table. experiment 1 experiment 2 final burette reading / cm3 initial burette reading / cm3 difference / cm3 [4]  (b)  experiment 3   empty the conical flask and rinse it with distilled water.   pour away the contents of the burette and rinse the burette with solution b of dilute  hydrochloric acid.  repeat experiment 1 using solution b instead of solution a.   record the burette readings in the table below and complete the table. experiment 3 final burette reading / cm3 initial burette reading / cm3 difference / cm3 [2]  (c)  what colour change was observed in the flask in experiment 1?  from .. to  ..   [1]",
            "3": "3 0620/51/m/j/16 \u00a9 ucles 2016 [turn over (d)  state one observation, other than colour change, when hydrochloric acid was added to sodium  carbonate.   ..   [1]  (e)  complete the sentence below.   experiment ... needed the largest volume of hydrochloric acid to change the colour of the  indicator. [1]  (f)  what would be a more accurate method of measuring the volume of the aqueous  sodium carbonate?   ..   [1]  (g)  what would be the effect on the results, if any, if the solutions of sodium carbonate were warmed before adding the hydrochloric acid? give a reason for your answer .   effect on results  .   reason   [2]  (h) (i)  determine the ratio of volumes of dilute hydrochloric acid used in experiments 1 and 3.   ...   [1]  (ii)  use your answer to (h)(i) to deduce how the concentration of solution a differs from that  of solution b.   ...   [1]  (i)  suggest a different method, using standard laboratory chemicals, to determine which of the  solutions of dilute hydrochloric acid, a or b, is more concentrated.               ..   [3]  (j)  hydrochloric acid is hazardous.   suggest one safety precaution to follow when using hydrochloric acid.   ..   [1] [total: 18]",
            "4": "4 0620/51/m/j/16 \u00a9 ucles 20162  you are provided with two substances. solid c is a salt and solution d is an aqueous solution of a  different salt.   carry out the following tests on each substance, recording all of your observations at each stage.  tests on solid c   add about half of solid c to about 10 cm3 of distilled water in a test-tube and shake to dissolve.   divide the solution into two equal portions in two test-tubes, and carry out the following tests.  (a) (i)  test the ph of the first portion of the solution.  ph  .   [1]  (ii)  to the second portion of the solution, add about 1 cm3 of dilute nitric acid followed by  aqueous silver nitrate.   record your observations.   ...   [2]  (b)  carry out a flame test on the rest of solid c.   record your observations.   ..   [1]  (c)  identify solid c.   ..   [2]  tests on solution d   divide the solution d into three equal portions in three test-tubes and carry out the following tests.  (d) (i)  describe the appearance of the solution.   ...   [1]  (ii)  to the first portion of the solution, add drops of aqueous sodium hydroxide until a change  is seen.   now add an excess of aqueous sodium hydroxide to the mixture.   record your observations.   .   ...   [3]",
            "5": "5 0620/51/m/j/16 \u00a9 ucles 2016 [turn over (iii)  to the second portion of the solution, add drops of aqueous ammonia until a change is  seen.   now add an excess of aqueous ammonia to the mixture.   record your observations.   .   ...   [2]  (iv)  to the third portion of the solution, add about 1 cm3 of dilute nitric acid followed by aqueous  silver nitrate.   record your observations.   .   ...   [2]  (e)  what conclusions can you draw about solution d?      ..   [2] [total: 16]",
            "6": "6 0620/51/m/j/16 \u00a9 ucles 20163  calcium burns in air to form calcium oxide. the reaction is vigorous and some of the calcium oxide  can be lost as smoke.   plan an investigation to determine the maximum mass of oxygen that combines to form calcium oxide when 2 g of calcium granules are burnt in air.   you are provided with common laboratory apparatus and calcium granules.   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "7": "7 0620/51/m/j/16 \u00a9 ucles 2016notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt. or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "8": "8 0620/51/m/j/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. test for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidifed aqueous potassium  manganate( vii) from purple to  colourless"
        },
        "0620_s16_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/52   paper 5 practical test may/june 2016  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructions cambridge international examinations cambridge international general certificate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib16 06_0620_52/6rp\u00a9 ucles 2016 *3068860685* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/52/m/j/16 \u00a9 ucles 20161  you are going to investigate the rate of reaction between hydrogen peroxide and aqueous  potassium iodide. when these chemicals react they form iodine. sodium thiosulfate solution reacts  with iodine and can be used to show how fast the reaction proceeds.  read all the instructions carefully before starting the experiment.  instructions  (a)  fill the burette up to the 40.0 cm3 mark with sodium thiosulfate solution.   use the large measuring cylinder to pour 100 cm3 of distilled water into the conical flask.   use the small measuring cylinder to add 6 cm3 of sulfuric acid, 1 cm3 of starch solution and  4 cm3 of aqueous potassium iodide to the flask.   add 1.0 cm3 of sodium thiosulfate solution from the burette to the mixture in the flask and swirl  to mix.   several measurements will be taken during this experiment. once the timer has been started leave it running until the experiment is complete.   use the small measuring cylinder to start the reaction by adding 3 cm 3 of hydrogen peroxide  solution to the flask. immediately start your timer and swirl the mixture.   note the time taken for a blue colour to appear and record the time in the table.   add a further 0.5 cm3 of sodium thiosulfate solution to the mixture in the conical flask and swirl  until the blue colour disappears.   note the time when the blue colour reappears and record the time in the table below.   continue the experiment adding a further 0.5 cm3 of sodium thiosulfate solution at a time until  a total of 4.0 cm3 of sodium thiosulfate solution has been added, noting the times for the blue  colour to appear after each addition and recording the times in the table.   complete the table. total volume of sodium thiosulfate solution  added / cm3time at which blue colour appears / s 1.0 1.5 4.0 [4]",
            "3": "3 0620/52/m/j/16 \u00a9 ucles 2016 [turn over (b)  plot the results you have obtained on the grid and draw a best-fit straight-line graph. 0.0 0.5 1.0 1.5 2.0 volume of sodium thiosulfate solution  / cm32.5 3.0 3.5 4.0 4.5time / s [5]  (c) (i)  from your graph deduce the time for the blue colour to appear if only 0.5 cm3 of  sodium thiosulfate solution had been added to the mixture in the conical flask.   show clearly on the grid  how you worked out your answer.   ...   [3]  (ii)  sketch on the grid the graph you would expect if the experiment was repeated at a higher  temperature. [1]",
            "4": "4 0620/52/m/j/16 \u00a9 ucles 2016 (d)  suggest the purpose of the starch solution.   ..   [1]  (e) (i)  suggest one advantage of using a pipette to measure the volume of the hydrogen peroxide.   ...   [1]  (ii)  suggest and explain one disadvantage of using a pipette to measure the volume of the  hydrogen peroxide.   .   ...   [2]  (f)  explain one disadvantage of using a beaker instead of a conical flask.      ..   [1] [total: 18]",
            "5": "5 0620/52/m/j/16 \u00a9 ucles 2016 [turn over2  you are provided with two solids, e and f, which are both water soluble.   carry out the following tests on the solids, recording all of your observations at each stage.  tests on solid e  (a)  use a spatula to place half of solid e into a test-tube.   add about 10 cm3 of distilled water to the solid and shake the mixture to dissolve.   divide the solution into three equal portions in three test-tubes and carry out the following  tests.  (i)  add about 1 cm3 of aqueous sodium hydroxide to the first portion of the solution.   record your observations.   ...   [1]  (ii)  add about 1 cm3 of aqueous barium nitrate to the second portion of the solution.   now add excess dilute nitric acid to the mixture.   record your observations.   .   ...   [2]  (iii)  pour the third portion of the solution into a boiling tube and add about 1 cm3 of dilute  hydrochloric acid. warm the mixture gently. test the gas given off with a piece of filter  paper soaked in aqueous potassium manganate( vii) solution.   record your observations.   .   ...   [2]  (b)  carry out a flame test on the rest of solid e.   record your observations.   ..   [1]  (c)  what conclusions can you draw about solid e?      ..   [2]",
            "6": "6 0620/52/m/j/16 \u00a9 ucles 2016 tests on solid f  use a spatula to divide solid f into two portions in two test-tubes.  (d)  describe the appearance of solid f.   ..   [1]  (e) (i)  heat the first portion of solid f, gently then strongly.   test the gas given off with damp red litmus paper.   record your observations.   .   ...   [3]  (ii)  let the solid residue cool down for a few minutes. to the residue add a few drops of  copper( ii) sulfate solution followed by a few drops of aqueous sodium hydroxide and   shake the mixture.   record your observations.   ...   [1]  (f)  tip the second portion of solid f into a boiling tube.   add about 3 cm3 of aqueous sodium hydroxide to the boiling tube and heat the mixture gently.  test the gas given off.   record your observations.      ..   [2]  (g)  identify one of the ions in solid f.   ..   [1] [total: 16]",
            "7": "7 0620/52/m/j/16 \u00a9 ucles 2016 [turn over3  potassium sulfate is the salt made when sulfuric acid is neutralised by potassium hydroxide solution.   the correct amount of potassium hydroxide solution must be added to neutralise all of the sulfuric  acid.   plan an experiment to obtain pure crystals of potassium sulfate from sulfuric acid and potassium hydroxide solution.   you are provided with common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "8": "8 0620/52/m/j/16 \u00a9 ucles 2016blank page",
            "9": "9 0620/52/m/j/16 \u00a9 ucles 2016blank page",
            "10": "10 0620/52/m/j/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/52/m/j/16 \u00a9 ucles 2016notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt. or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/52/m/j/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. test for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidifed aqueous potassium  manganate( vii) from purple to  colourless"
        },
        "0620_s16_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/53   paper 5 practical test may/june 2016  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructions cambridge international examinations cambridge international general certificate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib16 06_0620_53/6rp\u00a9 ucles 2016 *9424482312* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/53/m/j/16 \u00a9 ucles 20161  you are going to investigate what happens when dilute hydrochloric acid and copper( ii) sulfate  solution react with different metals.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out five experiments.  (a)  experiment 1   use a measuring cylinder to pour 10 cm3 of dilute hydrochloric acid into a boiling tube. put the  boiling tube into a rack for support.   measure the temperature of the hydrochloric acid and record it in the table below.   add 1 g of zinc to the boiling tube and stir the mixture with the thermometer.   measure and record the maximum temperature reached by the mixture. pour the mixture away  and rinse the boiling tube.   experiment 2   repeat experiment 1 using 1 g of iron instead of zinc.   record your results in the table.   experiment 3   repeat experiment 1 using 1 g of magnesium instead of zinc.   record your results in the table. complete the final column in the table. experimentinitial temperature of acid / \u00b0cmaximum temperature reached / \u00b0ctemperature rise / \u00b0c 1 23 [3]  (b)  experiment 4   use a measuring cylinder to pour 10 cm 3 of copper( ii) sulfate solution into a boiling tube.  measure the temperature of the solution and record it in the table on page 3.   add 1 g of magnesium to the boiling tube and stir the mixture with the thermometer.   test the gas given off with a splint and record your result in the space below. measure the  maximum temperature reached by the mixture and record it in the table. pour the mixture away  and rinse the boiling tube.  test  .  result  .. [1]",
            "3": "3 0620/53/m/j/16 \u00a9 ucles 2016 [turn over (c)  experiment 5   repeat experiment 4 using 1 g of iron instead of magnesium. you do not need to test the gas.   record your observations in the space below and record your temperatures in the table.   complete the final column in the table. experiment initial temperature / \u00b0cmaximum temperature / \u00b0ctemperature rise / \u00b0c 4 5  observation   [3]  (d)  draw a labelled bar chart for the results of experiments 1, 2, 3, 4 and 5 on the grid. temperature rise  / \u00b0c [3]",
            "4": "4 0620/53/m/j/16 \u00a9 ucles 2016  use your results and observations for experiments 1, 2 and 3 to answer the following questions.  (e) (i)  which experiment, 1, 2 or 3, produced the largest temperature rise?   ...   [1]  (ii)  suggest why this experiment produced the largest temperature rise.   .   ...   [1]  (f)  name the gas given off in experiment 4.   ..   [1]  (g)  suggest why potassium was not used as one of the metals in these experiments.   ..   [1]  (h)  give one advantage of using a measuring cylinder to add the hydrochloric acid to the boiling  tube.   ..   [1]  (i)  suggest and explain one change to improve the accuracy of these experiments.         ..   [2] [total: 17]",
            "5": "5 0620/53/m/j/16 \u00a9 ucles 2016 [turn over2  you are provided with a mixture of two solids, g and h.   solid g is water soluble and solid h is insoluble in water.   carry out the following tests on the mixture, recording all of your observations at each stage.   add about 15 cm3 of distilled water to the mixture in a boiling tube.   shake the boiling tube for one minute. filter the contents of the tube, keeping the filtrate and the  residue. divide the filtrate into four equal portions in four test-tubes and carry out the following  tests.  tests on filtrate  (a) (i)  add several drops of aqueous sodium hydroxide to the first portion of the solution and  shake the test-tube.   now add excess aqueous sodium hydroxide to the test-tube.   record your observations.   .   .   ...   [3]  (ii)  using the second portion of the solution, repeat the test in (a)(i) using aqueous ammonia  instead of aqueous sodium hydroxide.   record your observations.   .   ...   [2]  (iii)  add a few drops of dilute nitric acid to the third portion of the solution followed by about  1 cm3 of aqueous silver nitrate.   record your observations.   ...   [1]  (iv)  pour the fourth portion of the solution into a boiling tube.   add about 1 cm3 of aqueous sodium hydroxide and a small piece of aluminium foil.   warm the mixture carefully and test the gas given off.   record your observations.   .   .   ...   [3]  (b)  identify solid g.      ..   [2]",
            "6": "6 0620/53/m/j/16 \u00a9 ucles 2016 tests on the residue  (c)  use a spatula to transfer some of the residue into a test-tube.   to the residue, add about 2 cm3 of dilute hydrochloric acid. test any gases given off.   record your observations.         ..   [3]  (d)  carry out a flame test on the residue.   record your observations.   ..   [1]  (e)  identify solid h.      ..   [2] [total: 17]",
            "7": "7 0620/53/m/j/16 \u00a9 ucles 2016 [turn over3  nickel sulfate-6-water, niso4.6h2o, is a blue crystalline salt.   plan an experiment to obtain a sample of pure water from this salt. your answer should include  a diagram of the apparatus, any expected observations and a test to show the presence of pure  water.   you are provided with common laboratory apparatus.   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "8": "8 0620/53/m/j/16 \u00a9 ucles 2016blank page",
            "9": "9 0620/53/m/j/16 \u00a9 ucles 2016blank page",
            "10": "10 0620/53/m/j/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/53/m/j/16 \u00a9 ucles 2016notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt. or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/53/m/j/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. test for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidifed aqueous potassium  manganate( vii) from purple to  colourless"
        },
        "0620_s16_qp_61.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib16 06_0620_61/3rp \u00a9 ucles 2016 *3845366912* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/61   paper 6 alternative to practical may/june 2016  1 hour candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/61/m/j/16 \u00a9 ucles 20161  the diagram shows the apparatus used to separate a mixture of water, boiling point 100 \u00b0c, and  ethanol, boiling point 78 \u00b0c. heat heatwater and ethanol mixturecondenser  (a)  complete the boxes to name the apparatus. [2]  (b)  label the arrows on the condenser. [1]  (c)  identify one mistake in the apparatus.   ..   [1]  (d)  which liquid would collect first? explain your answer.      ..   [2]  (e)  why would it be better to use an electrical heater instead of a bunsen burner to heat the water  and ethanol mixture?   ..   [1] [total: 7]",
            "3": "3 0620/61/m/j/16 \u00a9 ucles 2016 [turn over2  a student investigated the reaction between aqueous sodium carbonate and two different solutions  of dilute hydrochloric acid, a and b.   the reaction is: na2co3(aq)  +  2hcl (aq)  \u2192  2nacl (aq)  +  h2o(l)  +  co2(g)   three experiments were carried out.  (a)  experiment 1   using a measuring cylinder, 25 cm3 of aqueous sodium carbonate were poured into a conical  flask.    thymolphthalein indicator was added to the conical flask.   a burette was filled up to the 0.0 cm3 mark with solution a of dilute hydrochloric acid. a was  added to the flask, until the solution just changed colour.   use the burette diagram to record the reading in the table. 12 13 14 final readin g   experiment 2   experiment 1 was repeated using methyl orange indicator instead of thymolphthalein.   methyl orange is red-orange in acidic solutions and yellow in alkaline solutions.   use the burette diagrams to record the readings in the table and complete the table. 38 39 40 final readin g12 13 14 initial reading experiment 1 experiment 2 final burette reading / cm3 initial burette reading / cm3 difference / cm3 [4]",
            "4": "4 0620/61/m/j/16 \u00a9 ucles 2016 (b)  what colour change was observed in the flask in experiment 2?   from  to     [1]  (c)  experiment 3   experiment 1 was repeated using solution b of acid instead of solution a.   use the burette diagrams to record the readings in the table and complete the table. 15 16 17 final readin g8 9 10 initial reading experiment 3 final burette reading / cm3 initial burette reading / cm3 difference / cm3 [2]  (d)  suggest one observation, other than colour change, that is made when hydrochloric acid is  added to sodium carbonate.   ..   [1]  (e)  complete the sentence below.   experiment .. needed the largest volume of hydrochloric acid to change the colour of the  indicator. [1]  (f)  what would be a more accurate method of measuring the volume of the aqueous sodium carbonate?   ..   [1]",
            "5": "5 0620/61/m/j/16 \u00a9 ucles 2016 [turn over (g)  what would be the effect on the results, if any, if the solutions of sodium carbonate were  warmed before adding the hydrochloric acid? give a reason for your answer .   effect on results  .   reason   [2]  (h) (i)  determine the ratio of volumes of dilute hydrochloric acid used in experiments 1 and 3.   ...   [1]  (ii)  use your answer to (h)(i) to deduce how the concentration of solution a differs from that  of solution b.   ...   [1]  (i)  suggest a different method, using standard laboratory chemicals, to determine which of the  solutions of dilute hydrochloric acid, a or b, is more concentrated.               ..   [3] [total: 17]",
            "6": "6 0620/61/m/j/16 \u00a9 ucles 20163  two substances, c and d, were analysed. solid c was a salt and solution d was an aqueous  solution of chromium( iii) chloride.   the tests on solid c, and some of the observations, are in the following table. tests observations tests on solid c solid c was added to distilled water in a  test-tube and shaken to dissolve.the solution was divided into two portions in  test-tubes, and the following tests carried out.  appearance of the solution.  the ph of the first portion of the solution was  tested.colourless liquid ph = 7  dilute nitric acid was added to the second  portion of the solution followed by aqueous silver nitrate.cream precipitate  a flame test was carried out on solid c. yellow flame colour  (a)  identify solid c.   ..   [2]  (b)  describe the appearance of solution d.   ..   [1]  (c)  tests were carried out on solution d.   complete the observations for tests 1, 2 and 3.  (i)  test 1   drops of aqueous sodium hydroxide were added to solution d.   excess aqueous sodium hydroxide was then added to the mixture.  observations  ...   ...   [3]",
            "7": "7 0620/61/m/j/16 \u00a9 ucles 2016 [turn over (ii)  test 2   excess aqueous ammonia was added to solution d.  observations  .   [2]  (iii) test 3   dilute nitric acid was added to solution d followed by aqueous silver nitrate.  observations  .   [1]  (d)  chromium( iii) can be converted to chromium( vi). chromium( vi) is hazardous.   suggest one safety precaution when using chromium( vi).   ..   [1] [total: 10]",
            "8": "8 0620/61/m/j/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 4  calcium burns in air to form calcium oxide. the reaction is vigorous and some of the calcium oxide  can be lost as smoke.   plan an investigation to determine the maximum mass of oxygen that combines to form calcium  oxide when 2 g of calcium granules are burnt in air.   you are provided with common laboratory apparatus and calcium granules.   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]"
        },
        "0620_s16_qp_62.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib16 06_0620_62/4rp \u00a9 ucles 2016 *2553361951* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/62   paper 6 alternative to practical may/june 2016  1 hour candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/m/j/16 \u00a9 ucles 20161  the diagram shows the apparatus used to reduce copper( ii) oxide with hydrogen. hydrogencopper( ii) oxideexcess hydrogen burning in air ice colourless liqui d  (a)  complete the boxes to name the apparatus. [2]  (b)  use an arrow to indicate where heat is applied. [1]  (c)  the colour of the copper( ii) oxide changes from . to  . [2]  (d)  suggest a reason why the u-tube is surrounded by ice.   ..   [1]  (e) (i)  identify the colourless liquid formed.   ...   [1]  (ii)  give a chemical test for this liquid.  test  ..  result  ... [2]  (iii)  how could you show that this liquid is pure?   ...   [1] [total: 10]",
            "3": "3 0620/62/m/j/16 \u00a9 ucles 2016 [turn over2  a student investigated the rate of reaction between hydrogen peroxide and aqueous potassium iodide. when these chemicals react they form iodine. sodium thiosulfate solution reacts with iodine and can be used to show how fast the reaction proceeds.  (a)  a burette was filled up to the 0.0 cm 3 mark with sodium thiosulfate solution.   using a large measuring cylinder, 100 cm3 of distilled water were poured into a conical flask.   using a small measuring cylinder, 6 cm3 of sulfuric acid, 1 cm3 of starch solution and 4 cm3 of  aqueous potassium iodide were added to the flask.   0.5 cm3 of sodium thiosulfate solution was added from the burette to the mixture in the flask  and swirled to mix.   the reaction was then started by adding 3 cm3 of hydrogen peroxide solution to the mixture,  and the timer started.   the time taken for a blue colour to appear was noted.   a further 0.5 cm3 of sodium thiosulfate solution was added to the mixture in the conical flask,  swirled and the blue colour disappeared. the time when the blue colour reappeared was noted.   the experiment continued by adding further 0.5 cm3 portions of sodium thiosulfate solution  until a total of 3.0 cm3 of sodium thiosulfate solution had been added, noting the times at which  the blue colour reappeared.   use the timer diagrams on page 4 to record the times in seconds in the table.",
            "4": "4 0620/62/m/j/16 \u00a9 ucles 20160.5total volume of sodium thiosulfate solution added  / cm3timer diagramtime at which blue colour appeared  / s 1.0 1.5 2.0 2.5 3.0second s minutes0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5 [3]",
            "5": "5 0620/62/m/j/16 \u00a9 ucles 2016 [turn over (b)  plot the results you have obtained on the grid and draw a best-fit straight-line graph. 0.0 0.5 1.0 1.5 2.0 volume of sodium thiosulfate solution  / cm32.5 3.0 3.5 4.0time  / s [5]  (c) (i)  from your graph deduce the time at which the blue colour would appear if a total of  4.0 cm3 of sodium thiosulfate solution were added to the mixture in the conical flask.   show clearly on the grid  how you worked out your answer.   ...   [3]  (ii)  sketch on the grid the graph you would expect if the experiment was repeated at a higher  temperature. [1]",
            "6": "6 0620/62/m/j/16 \u00a9 ucles 2016 (d)  suggest the purpose of the starch solution.   ..   [1]  (e) (i)  suggest one advantage of using a pipette to measure the volume of the hydrogen peroxide.   ...   [1]  (ii)  suggest and explain one disadvantage of using a pipette to measure the volume of the  hydrogen peroxide.   .   ...   [2]  (f)  explain one disadvantage of using a beaker instead of a conical flask.      ..   [1] [total: 17]",
            "7": "7 0620/62/m/j/16 \u00a9 ucles 2016 [turn over3  two solids, e and f, were analysed. solid e was sodium sulfite. both solids were found to be water  soluble.   the tests on the solids, and some of the observations, are shown below.  tests on solid e  (a)  describe the appearance of the solid.   ..   [1]  (b)  distilled water was added to solid e in a test-tube and shaken to dissolve.   the solution was divided into two portions in two test-tubes and the following tests carried out.  (i)  aqueous sodium hydroxide was added to the first portion of the solution.  observations  .   [1]  (ii)  dilute hydrochloric acid was added to the second portion of the solution. the mixture  was warmed. the gas given off was tested with a piece of filter paper soaked in aqueous acidified potassium manganate( vii) solution.  observations  ...   ...   [2]  (c)  a flame test was carried out on solid e.  observations     [1]   tests on solid f tests observations the solid was heated. the gas given off was  tested with damp, red litmus paper.pungent gas evolved red litmus paper turned blue aqueous sodium hydroxide was added to solid f and the mixture heated. the gas given  off was tested.pungent gas evolved universal indicator paper showed ph 10  (d)  identify the gas given off in the tests on solid f.   ..   [1]  (e)  identify one of the ions in solid f.   ..   [1] [total: 7]",
            "8": "8 0620/62/m/j/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 4  potassium sulfate is the salt produced when sulfuric acid is neutralised by potassium hydroxide  solution.   the correct amount of potassium hydroxide solution must be added to neutralise all of the  sulfuric acid.   plan an experiment to obtain pure crystals of potassium sulfate from sulfuric acid and  potassium hydroxide solution.   you are provided with common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]"
        },
        "0620_s16_qp_63.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib16 06_0620_63/4rp \u00a9 ucles 2016 *9448353441* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/63   paper 6 alternative to practical may/june 2016  1 hour candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/63/m/j/16 \u00a9 ucles 20161  air is a mixture of gases. the diagram shows the apparatus used to find the percentage of oxygen  in air.   50 cm3 of air were passed backwards and forwards over excess heated copper until there was no  further change. the apparatus was left to cool and the volume of gas remaining was 40 cm3. 20406080100 20406080 100copper  (a)  complete the box to name the apparatus. [1]  (b)  use an arrow to indicate where heat is applied. [1]  (c)  the colour of the copper changed from ... to ... . [2]  (d)  from the results, work out the percentage of oxygen in the air.  %  [2] [total: 6]",
            "3": "3 0620/63/m/j/16 \u00a9 ucles 2016 [turn over2  a student investigated what happens when dilute hydrochloric acid and copper( ii) sulfate solution  react with different metals.   five experiments were carried out.  (a)  experiment 1   a measuring cylinder was used to pour 10 cm3 of dilute hydrochloric acid into a boiling tube.   the temperature of the hydrochloric acid was measured.   1 g of zinc was added to the boiling tube and the mixture stirred with a thermometer.   the maximum temperature reached by the mixture was measured.   experiment 2   experiment 1 was repeated using 1 g of iron instead of zinc.   experiment 3   experiment 1 was repeated using 1 g of magnesium instead of zinc.   use the thermometer diagrams to record the results in the table. complete the final column in  the table. experimentthermometer diagraminitial temperature of acid  / \u00b0cthermometer diagrammaximum temperature reached  / \u00b0ctemperature rise  / \u00b0c 130 25 2030 25 20 230 25 2030 25 20 330 25 2065 60 55 [3]  (b)  the gas produced in experiment 3 was tested with a lighted splint and the result recorded  below.  test    result     name the gas given off in experiment 3.   ..   [1]lighted splint popped",
            "4": "4 0620/63/m/j/16 \u00a9 ucles 2016 (c)  experiment 4   a measuring cylinder was used to pour 10 cm3 of copper( ii) sulfate solution into a boiling tube.  the temperature of the solution was measured.   1 g of magnesium was added to the boiling tube and the mixture stirred with a thermometer.  the maximum temperature reached by the mixture was measured.   experiment 5   experiment 4 was repeated using 1 g of iron instead of magnesium.   the observation was recorded below. ..   use the thermometer diagrams to record the results in the table. complete the final column in  the table. experimentthermometer diagraminitial temperature of acid  / \u00b0cthermometer diagrammaximum temperature reached  / \u00b0ctemperature rise  / \u00b0c 430 25 2050 45 40 530 25 2030 25 20 [2]the solution turned colourless and a brown deposit formed.",
            "5": "5 0620/63/m/j/16 \u00a9 ucles 2016 [turn over (d)  draw a labelled bar chart for the results of experiments 1, 2, 3, 4 and 5 on the grid below. temperature rise  / \u00b0c [3]  (e)  use the results for experiments 1, 2 and 3 to answer the following questions.  (i)  which experiment, 1, 2 or 3, produced the largest temperature rise?   ...   [1]  (ii)  suggest why this experiment produced the largest temperature rise.   .   ...   [1]",
            "6": "6 0620/63/m/j/16 \u00a9 ucles 2016 (f)  explain the observations in experiment 5.         ..   [2]  (g)  suggest why potassium was not used as one of the metals in these experiments.   ..   [1]  (h)  give one advantage of using a measuring cylinder to add the hydrochloric acid to the boiling  tube.   ..   [1]  (i)  suggest and explain one improvement to increase the accuracy of these experiments.         ..   [2] [total: 17]",
            "7": "7 0620/63/m/j/16 \u00a9 ucles 2016 [turn over3  a mixture of two solids, g and h, was analysed. solid g was zinc nitrate, which is water soluble,  and solid h is insoluble in water.   the tests on the mixture, and some of the observations, are shown.   distilled water was added to the mixture in a boiling tube and shaken. the contents of the boiling  tube were filtered keeping the filtrate and the residue.  tests on filtrate  (a)  the filtrate was divided into four test-tubes and the following tests carried out.  (i)  drops of aqueous sodium hydroxide were added to the first portion of the solution.   excess aqueous sodium hydroxide was then added to the test-tube.  observations  ...   .   ...   [3]  (ii)  using the second portion of the solution, the test in (a)(i) was repeated using aqueous  ammonia instead of aqueous sodium hydroxide.  observations  ...   ...   [2]  (iii)  dilute nitric acid was added to the third portion of the solution followed by aqueous silver  nitrate.  observations  .   [1]  (iv)  aqueous sodium hydroxide and aluminium foil were added to the fourth portion of the solution.   the mixture was warmed and the gas given off was tested.  observations  ...   .   ...   [3]",
            "8": "8 0620/63/m/j/16 \u00a9 ucles 2016  tests on residue   two tests are carried out and the following observations made. tests observations a spatula was used to transfer some of the  residue into a test-tube. dilute hydrochloric acid was added to the  residue. the gas given off was tested.rapid effervescence, limewater turned milky a flame test was carried out on the residue. red flame colour  (b)  identify solid h.      ..   [2] [total: 11]",
            "9": "9 0620/63/m/j/16 \u00a9 ucles 2016 [turn over4  nickel sulfate-6-water, niso4.6h2o, is a blue crystalline salt.   plan an experiment to obtain a sample of pure water from this salt. your answer should include  a diagram of the apparatus, any expected observations and a test to show the presence of pure  water.   you are provided with common laboratory apparatus.   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "10": "10 0620/63/m/j/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/63/m/j/16 \u00a9 ucles 2016blank page",
            "12": "12 0620/63/m/j/16 \u00a9 ucles 2016blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. "
        },
        "0620_w16_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 17 printed pages and 3 blank pages.  ib16 11_0620_11/6rp  \u00a9 ucles 2016 [turn over     *6275559010* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice (core)  october/november 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 20.  electronic calculators may be used.          ",
            "2": "2  \u00a9 ucles 2016 0620/11/o/n/16  1 \u2018particles moving very slowly  from an area of higher concentration to an area of lower  concentration.\u2019    which process is being described?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air     2 a student mixes 25  cm3 samples of dilute hydrochloric acid with different volumes of aqueous  sodium hydroxide.     in each case, the student measures the change in temperature to test if the reaction is exothermic.    which piece of apparatus is not needed?    burette clock pipette thermometerab c d     ",
            "3": "3  \u00a9 ucles 2016 0620/11/o/n/16 [turn over  3 information about the solubility of four solids, p, q, r and s, is given in the table.     p q r s  solubility in water dissolves insoluble insoluble dissolves    a student attempted to separate mixtures of these solids using the following method.    1 add the mixture to a beaker of water and stir.  2 filter the mixture. 3 crystallise one of the solids from the filtrate.    which of the following mixtures could not be separated by this method?  a a mixture of p and r  b a mixture of q and p  c a mixture of q and r  d a mixture of r and s      4 the table shows information about atoms of three different elements.    element proton  number nucleon  number number of  protons number of  neutrons number of  electrons  chlorine 17 35 17 w 17  chlorine 17 x 17 19 17  argon y 40 18 22 18  potassium 19 39 19 20 z    what are the values of w, x, y and z?     w x y z  a 18 35 18 19  b 18 36 18 19  c 19 35 19 18  d 19 36 19 18     ",
            "4": "4  \u00a9 ucles 2016 0620/11/o/n/16  5 the diagrams show the structures of two forms of the same element.    tu    what are the reasons for using t in cutting tools and u as a lubricant?     t u  a   it is very hard because each atom is  held in place by strong covalent bonds. the layers can slide over each other  because the covalent bonds are weak.  b   it is very hard because each atom is  held in place by strong covalent bonds. the layers can slide over each other  due to weak forces between the layers.  c   it is very hard because there are  no electrons able to move. the layers can slide over each other  because the covalent bonds are weak.  d   it is very hard because there are  no electrons able to move. the layers can slide over each other  due to weak forces between the layers.      6 ions are formed by elements losing or gaining electrons.    which statement is correct?  a metal atoms gain electrons to form positive ions.  b non-metal atoms lose electrons to form positive ions.  c the charge on an ion is always either +1 or \u20131.  d group i ions have the same electronic structure as noble gases.      7 a molecule of x contains two carbon atoms, four hydrogen atoms and two oxygen atoms.    what is the formula of x?  a ch 2co 2h b ch 3coh c ch 3cooh d c2h3cooh    ",
            "5": "5  \u00a9 ucles 2016 0620/11/o/n/16 [turn over  8 concentrated aqueous potassium chloride is electrolysed using platinum electrodes.    the solution contains the ions k+, c l \u2013, h+ and oh\u2013.    which electrodes are the ions attracted to during this electrolysis?     anode cathode  a cl \u2013 and k+ h+ and oh\u2013  b cl \u2013 and oh\u2013 h+ and k+  c h+ and k+ cl \u2013 and oh\u2013  d h+ and oh\u2013 cl \u2013 and k+     9 which apparatus could be used to electroplate an iron nail with copper?    +\u2013a +\u2013b +\u2013cdaqueous copper( ii) sulfate aqueous iron( ii) sulfate+\u2013key = copper sheet = iron nail      ",
            "6": "6  \u00a9 ucles 2016 0620/11/o/n/16  10 when anhydrous copper( ii) sulfate is added to water a solution is formed and heat is given out.    wateranhydrous copper( ii) sulfatethermometer     which row shows the temperature change and the type of reaction taking place?     temperature change type of reaction  a decrease endothermic  b decrease exothermic  c increase endothermic  d increase exothermic      11 the combustion of element x releases large amounts of energy.   what is x?  a ethanol  b hydrogen  c methane  d uranium     ",
            "7": "7  \u00a9 ucles 2016 0620/11/o/n/16 [turn over  12 the rate of reaction between magnesium and excess dilute hydrochloric acid was followed by  measuring the mass of magnesium present at regular time intervals.    two experiments were performed.    both experiments used 0.1  g of magnesium ribbon. the acid in experiment 1 was less  concentrated than in experiment 2.    which graph shows the results of the experiments?    a mass of magnesium time c mass of magnesium time1 2 2 1b mass of magnesium time d0 00 00 00 0mass of magnesium time2 1 1 2       13 which reaction is reversible?  a cuco 3  +  2hc l  \u2192  cuc l 2  +  co 2  +  h 2o  b cuso 4.5h 2o  \u2192  cuso 4  +  5h 2o  c 2na  +  2h 2o  \u2192  2naoh  +  h 2  d naoh  +  hc l  \u2192  nac l  +  h 2o      14 tin is formed when tin( ii) oxide is heated with carbon.    what happens to the tin in the tin( ii) oxide in this reaction?  a it is burnt.  b it is electrolysed.  c it is oxidised.  d it is reduced. ",
            "8": "8  \u00a9 ucles 2016 0620/11/o/n/16  15 part of the periodic table is shown.    which element forms an acidic oxide?    a dcb       16 four substances, p, q, r and s, are tested as shown.    test substance  p q r s  dilute hydrochloric  acid added gas given off  which \u2018pops\u2019 with  a lighted splint gas given off  which turns  limewater milky no reaction no reaction  dilute aqueous  sodium hydroxide  added and  warmed gently no reaction no reaction gas given off  which turns  damp, red litmus  paper blue no reaction    what are p, q, r and s?     p q r s  a mg na 2co 3 nh 4cl nac l  b mg nh 4cl na 2co 3 nac l  c mg na 2co 3 nac l nh 4cl  d na2co 3 mg nac l nh 4cl     17 acids can react with metal oxides, carbonates and metals.    which reactions produce a gas?     acid with  metal oxide acid with  carbonate acid with  metal   a \u0016 \u0016 \u0016 key  b \u0016 \u001a \u001a \u0016= gas is produced  c \u001a \u0016 \u0016 \u001a= no gas is produced  d \u001a \u0016 \u001a      ",
            "9": "9  \u00a9 ucles 2016 0620/11/o/n/16 [turn over  18 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ystirrer solid x aqueous copper( ii) sulfateexcess of solid xfilter paper heat    what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride sulfuric acid  c copper( ii) oxide sulfuric acid  d sulfur aqueous copper( ii) chloride      19 which statement about trends in the periodic table is not correct?  a elements in the same period have the same number of electron shells.  b the elements change from metals to non-metals from left to right.  c the number of protons in an atom of an element increases from left to right.  d the oxides of the elements change from acidic to basic from left to right.      20 what is not a property of group i metals?  a they are soft and can be cut with a knife.  b they react when exposed to oxygen in the air.  c they produce an acidic solution when they react with water.  d they react rapidly with water producing hydrogen gas.      21 which statement about the element with proton number 54 is correct?  a it burns in the air to form an oxide.  b it could be used in balloons because it has a very low density.  c it is a gas at room temperature.  d it is reactive because it has a full outer shell of electrons.   ",
            "10": "10  \u00a9 ucles 2016 0620/11/o/n/16  22 which element is a transition element?     colour of  chloride melting point of  element  / \u00b0c  a orange 113  b orange 1535  c white 113  d white  1535     23 which row describes the trends in the properties of the group vii elements as the group is  descended?     colour density reactivity with  halide ions  a darkens decreases increases  b darkens increases decreases  c lightens decreases increases  d lightens increases decreases     24 four metals are listed in decreasing order of reactivity.    magnesium  zinc iron copper    titanium reacts with acid and cannot be extr acted from its ore by heating with carbon.    where should titanium be placed in the list?  a below copper  b between iron and copper  c between magnesium and zinc  d between zinc and iron    ",
            "11": "11  \u00a9 ucles 2016 0620/11/o/n/16 [turn over  25 impure iron from the blast furnace is converted to steel as shown.    oxygen impure molten iron     which statement about the process is correct?  a acidic oxides are added to remove alkaline impurities.  b coke is added as a reducing agent.  c oxygen is blown in to oxidise the impure iron.  d the steel produced contains less carbon than the impure iron.     26 a student added dilute hydrochloric acid to four metals and recorded the results.     some of the results are not correct.     results  metal gas given off  1 copper yes  2 iron yes  3 magnesium no  4 zinc yes    which two results are correct?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "12": "12  \u00a9 ucles 2016 0620/11/o/n/16  27 some properties of three metals, p, q and r, are shown.    metal density resistance to corrosion electrical conductivity  p low high very good  q high high very good  r low low good    which metals would be suitable for use in electrical wiring and aircraft manufacture?     electrical wiring aircraft manufacture  a p q  b q p  c q r  d r p     28 one sample of sea-water is distilled while another sample of sea-water is filtered.    which statement about the samples is correct?  a the distilled sample boils at exactly 100  \u00b0c and contains dissolved salts.  b the distilled sample boils at 103  \u00b0c and does not contain dissolved salts.  c the filtered sample boils at 103  \u00b0c and contains dissolved salts.  d the filtered sample boils at exactly 100  \u00b0c and does not contain dissolved salts.     29 air is a mixture of gases.    which gas is present in the largest amount?  a argon  b carbon dioxide  c nitrogen  d oxygen     ",
            "13": "13  \u00a9 ucles 2016 0620/11/o/n/16 [turn over  30 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0016 \u001a key  b greenhouse gas \u0016 \u0016 \u0016 = true  c present in unpolluted air \u001a \u001a \u001a = false  d produced during respiration \u001a \u0016       31 a mixture of two substances, x and y, is heated.    the damp, red litmus paper turns blue.    damp, red litmus paper x and y gentle heat    what are x and y?     x y  a aluminium nitrate hydrochloric acid  b aluminium nitrate sodium hydroxide solution  c ammonium chloride hydrochloric acid  d ammonium chloride sodium hydroxide solution     ",
            "14": "14  \u00a9 ucles 2016 0620/11/o/n/16  32 in the experiment shown, a white precipitate forms in the limewater.    x ylimewate r     what are x and y?     x y  a aqueous sodium hydroxide zinc  b aqueous sodium hydroxide zinc carbonate  c dilute sulfuric acid zinc  d dilute sulfuric acid zinc carbonate     33 which box corresponds to limestone?    does limestone contain carbon? yes no yes nodoes limestone burn? does limestone burn? abyes no cd     ",
            "15": "15  \u00a9 ucles 2016 0620/11/o/n/16 [turn over  34 petroleum is an important fossil fuel.    which row correctly describes petroleum?     type of substance composition  a compound mainly hydrocarbons  b compound only hydrogen and carbon  c mixture mainly hydrocarbons  d mixture only hydrogen and carbon      35 butane reacts as shown.    butane butene  +  hydrogencatalyst  and heat     what is this type of reaction?  a combustion  b cracking  c polymerisation  d reduction    36 which substance is in the same homologous series as methanol?    a cco ohb cc h ohh hhh cc c hhhhh hhh hhhc cch hhhd      37 which statement could not be correct for an alkane?  a it burns readily in a plentiful supply of air to form only carbon dioxide and water.  b it decolourises aqueous bromine.  c it has a boiling point of \u2013  42  \u00b0c.  d the carbon and hydrogen atoms in the molecule are joined by sharing pairs of electrons.     ",
            "16": "16  \u00a9 ucles 2016 0620/11/o/n/16  38 in which conical flask will ethanol be produced?    abcd water and sugarsugar and yeastwater, sugar and yeastwater and yeast     39 which molecule can be polymerised?    h ca h hhh cb h hchh hc hch hh hcd h ch o oc h     40 which row describes what happens when ethanol burns in air?     a white powder is left heat energy  is given out carbon dioxide  is formed water  is formed  a \u0016 \u001a \u0016 \u0016  b \u001a \u0016 \u0016 \u0016  c \u001a \u0016 \u0016 \u001a  d \u001a \u0016 \u001a \u0016     ",
            "17": "17    blank page   \u00a9 ucles 2016 0620/11/o/n/16  ",
            "18": "18    blank page   \u00a9 ucles 2016 0620/11/o/n/16  ",
            "19": "19    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.    to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.  cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/11/o/n/16  ",
            "20": "20  \u00a9 ucles 2016 0620/11/o/n/16   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w16_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib16 11_0620_12/7rp  \u00a9 ucles 2016 [turn over     *5967809337* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice (core)  october/november 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.          ",
            "2": "2  \u00a9 ucles 2016 0620/12/o/n/16  1 \u2018particles moving very slowly  from an area of higher concentration to an area of lower  concentration.\u2019    which process is being described?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air     2 a student mixes 25  cm3 samples of dilute hydrochloric acid with different volumes of aqueous  sodium hydroxide.     in each case, the student measures the change in temperature to test if the reaction is exothermic.    which piece of apparatus is not needed?    burette clock pipette thermometerab c d     3 a sample contains a mixture of powdered limestone (calcium carbonate), sugar and wax.    what is the correct way to obtain a pure sample of sugar?  a dissolve the mixture in dilute hydrochl oric acid, filter and wash the residue.  b dissolve the mixture in hexane, filter and evaporate the filtrate.  c dissolve the mixture in water, filter and evaporate the filtrate.  d dissolve the mixture in water, filter and wash the residue.     ",
            "3": "3  \u00a9 ucles 2016 0620/12/o/n/16 [turn over  4 the table shows information about four different particles.    particle proton  number nucleon  number number  of protons number  of neutrons number  of electrons na 11 23 11 w 11  na+ 11 23 11 12 x  o 8 16 8 y 8  o2\u2013 8 16 8 8 z    what are the values of w, x, y and z?     w x y z  a 11 10 10 8  b 11 11 8 10  c 12 10 8 10  d 12 11 10 8      5 which pair of statements about diamond and graphite is correct?    diamond graphite    a diamond and graphite are both pure carbon. they are both macromolecules.  b diamond and graphite can both be used as electrodes. graphite is also used as a lubricant.  c diamond has covalent bonds. graphite has ionic bonds.  d diamond is hard with a high melting point. graphite is soft with a low melting point.     ",
            "4": "4  \u00a9 ucles 2016 0620/12/o/n/16  6 which row shows the electronic structure of the sodium ion and the chloride ion in sodium  chloride?     sodium ion chloride ion  a 2,8 2,8,7  b 2,8 2,8,8  c 2,8,1 2,8,7  d 2,8,1 2,8,8     7 a molecule of x contains two bromine atoms,  three carbon atoms, six hydrogen atoms and one  oxygen atom.    what is the formula of x?  a chbro b c 3h6b2o c c3h6br2o d c3h6br2o     8 the diagram shows the electrolysis of conc entrated aqueous sodium chloride using inert  electrodes.    concentrated aqueous sodium chloride+ \u2013     which substances are produced at the electrodes?     anode cathode  a colourless gas colourless gas  b colourless gas green gas  c green gas colourless gas  d green gas green gas     ",
            "5": "5  \u00a9 ucles 2016 0620/12/o/n/16 [turn over  9 which apparatus could be used to electroplate an iron nail with copper?    +\u2013a +\u2013b +\u2013cdaqueous copper( ii) sulfate aqueous iron( ii) sulfate+\u2013key = copper sheet = iron nail      10 which experiment is the most exothermic?     initial  temperature  / \u00b0c final  temperature  / \u00b0c  a 20 5  b 20 32  c 25 12  d 25 34     11 which substance is not used as a fuel?  a bitumen  b diesel  c gasoline  d hydrogen     ",
            "6": "6  \u00a9 ucles 2016 0620/12/o/n/16  12 zinc granules are reacted with excess dilute hydrochloric acid.    the volume of hydrogen given off is measured at different times.    the results are shown on the graph, labelled experiment 1.    the results for a second experiment are also shown on the graph, labelled experiment 2.    00 timevolume of hydrogenexperiment 1 experiment 2     which change to the conditions was made in experiment 2?  a the concentration of the hydrochloric acid was decreased.  b the size of the zinc granules was decreased.  c the surface area of the zinc granules was increased.  d the temperature was increased.      13 when green crystals of nickel( ii) sulfate are heated, water is given off and a yellow solid remains.  when water is added to the yellow solid, the green colour returns.     which process describes these changes?   a combustion  b corrosion  c neutralisation   d reversible reaction     14 in which reaction is the copper compound reduced?  a cuco 3  \u2192  cuo  +  co 2  b cuo  +  h 2so 4  \u2192  cuso 4  +  h 2o  c cuso 4  +  2naoh  \u2192  cu(oh) 2  +  na 2so 4  d 2cuo  +  c  \u2192  2cu  +  co 2     ",
            "7": "7  \u00a9 ucles 2016 0620/12/o/n/16 [turn over  15 the element selenium forms the oxide seo 2. this oxide dissolves in concentrated aqueous  sodium hydroxide.    the element zirconium forms the oxide zro 2. this oxide dissolves in concentrated sulfuric acid.    how are the elements selenium and zirconium classified?     selenium zirconium  a metal metal  b metal non-metal  c non-metal metal  d non-metal non-metal      16 aqueous sodium hydroxide was added slowly, un til in excess, to separate solutions of  w, x, y and z.    the results are shown.    solution initial observation with   aqueous sodium hydroxide final observation with excess  aqueous sodium hydroxide  w white precipitate formed precipitate dissolves  x white precipitate formed no change  y pale blue precipitate formed no change  z green precipitate formed no change    which row identifies the metal ions in the solutions?     metal ion in  solution w metal ion in  solution x metal ion in  solution y metal ion in  solution z  a aluminium calcium copper( ii) iron( ii)  b aluminium calcium iron( ii) copper( ii)  c aluminium iron( ii) calcium copper( ii)  d calcium aluminium copper( ii) iron( ii)     ",
            "8": "8  \u00a9 ucles 2016 0620/12/o/n/16  17 acids can react with metal oxides, carbonates and metals.    which reactions produce a gas?     acid with  metal oxide acid with  carbonate acid with  metal   a \u0016 \u0016 \u0016 key  b \u0016 \u001a \u001a \u0016= gas is produced  c \u001a \u0016 \u0016 \u001a= no gas is produced  d \u001a \u0016 \u001a       18 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ystirrer solid x aqueous copper( ii) sulfateexcess of solid xfilter paper heat    what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride sulfuric acid  c copper( ii) oxide sulfuric acid  d sulfur aqueous copper( ii) chloride     ",
            "9": "9  \u00a9 ucles 2016 0620/12/o/n/16 [turn over  19 part of the periodic table is shown.    v xw yz     which statement about the elements is correct?  a v has a higher melting point than x.  b x is less reactive than v.  c y has less metallic character than z.  d z is more reactive than w.      20 what is not a property of group i metals?  a they are soft and can be cut with a knife.  b they react when exposed to oxygen in the air.  c they produce an acidic solution when they react with water.  d they react rapidly with water producing hydrogen gas.      21 which gas is not a noble gas?  a fluorine  b helium  c radon  d xenon     22 which element is a transition element?     colour of  chloride melting point of  element  / \u00b0c  a orange 113  b orange 1535  c white 113  d white  1535     ",
            "10": "10  \u00a9 ucles 2016 0620/12/o/n/16  23 which statement about the elements in group vii is not correct?  a br2 is less reactive than i2.  b cl 2 is used for water treatment.  c f2 is a covalent molecule.  d i2 forms a purple vapour when warmed.     24 four metals are listed in decreasing order of reactivity.    magnesium  zinc iron  copper    titanium reacts with acid and cannot be extr acted from its ore by heating with carbon.    where should titanium be placed in the list?  a below copper  b between iron and copper  c between magnesium and zinc  d between zinc and iron    25 impurities in iron obtained from the blast furnace include carbon, phosphorus and silicon.    which impurities are removed from the molten iron as gases when it is made into steel?  a carbon and phosphorus  b carbon and silicon  c carbon only  d phosphorus and silicon    ",
            "11": "11  \u00a9 ucles 2016 0620/12/o/n/16 [turn over  26 a student added dilute hydrochloric acid to four metals and recorded the results.     some of the results are not correct.     results  metal gas given off  1 copper yes  2 iron yes  3 magnesium no  4 zinc yes    which two results are correct?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     27 what is a common use of mild steel?  a aircraft manufacture  b electrical wiring  c making car bodies  d making cutlery    28 river water contains soluble impurities, insoluble impurities and bacteria.    river water is made safe to drink by filtration and chlorination.    which statement is correct?  a filtration removes bacteria and insoluble impurities, and chlorination removes soluble  impurities.  b filtration removes insoluble impurities, and chlorination kills the bacteria.  c filtration removes soluble and insoluble impurities, and chlorination kills the bacteria.  d filtration removes soluble impurities and bacteria, and chlorination removes insoluble  impurities.    29 air is a mixture of gases.    which gas is present in the largest amount?  a argon  b carbon dioxide  c nitrogen  d oxygen ",
            "12": "12  \u00a9 ucles 2016 0620/12/o/n/16  30 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0016 \u001a key  b greenhouse gas \u0016 \u0016 \u0016 = true  c present in unpolluted air \u001a \u001a \u001a = false  d produced during respiration \u001a \u0016       31 aqueous sodium hydroxide is added to a sample of a fertiliser and the mixture warmed.    ammonia gas is given off.    which ion does the fertiliser contain?  a ammonium  b nitrate  c phosphate  d potassium     32 which reaction would not result in the production of carbon dioxide?  a combustion of methane  b fermentation  c reaction between an acid and a metal  d respiration     33 which substance gives off carbon dioxide on heating?  a lime  b limestone  c limewater  d slaked lime    34 petroleum is separated into fractions.    which statement is not correct?  a each fraction contains a mixture of hydrocarbon molecules.  b fuel oil burns easily and is used as fuel in cars.  c refinery gas is the fraction containing the smallest molecules.  d the fractions are separated depending on their boiling point range. ",
            "13": "13  \u00a9 ucles 2016 0620/12/o/n/16 [turn over  35 butane reacts as shown.    butane butene  +  hydrogencatalyst  and heat     what is this type of reaction?  a combustion  b cracking  c polymerisation  d reduction     36 which compound is not a member of the alkene homologous series?  a ch 3chch 2  b ch 3ch 2chch 2  c ch 3chchch 3  d ch 3ch 2ch 2ch 2ch 3     37 which compound decolourises aqueous bromine?  a 2-methylpropane  b butane  c cyclohexane  d hexene    38 the equation represents the fermentation of x.    x   yeast  ethanol  +  carbon dioxide    what is x?  a ethanoic acid  b ethene  c glucose  d methanol     ",
            "14": "14  \u00a9 ucles 2016 0620/12/o/n/16  39 which molecule can be polymerised?    h ca h hhh cb h hchh hc hch hh hcd h ch o oc h      40 which equation for the complete combustion of ethanol is correct?  a c2h5oh  +  3o 2  \u2192  2co 2  +  3h 2o  b 2c2h5oh  +  7o 2  \u2192  4co 2  +  6h 2o  c 2c2h5oh  +  5o 2  \u2192  2co 2  +  6h 2o  d 4c2h5oh  +  7o 2  \u2192  4co 2  +  10h 2o     ",
            "15": "15    blank page     permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.    to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.  cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/12/o/n/16  ",
            "16": "16  \u00a9 ucles 2016 0620/12/o/n/16   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w16_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 17 printed pages and 3 blank pages.  ib16 11_0620_13/6rp  \u00a9 ucles 2016 [turn over     *3471311180* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice (core)  october/november 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 20.  electronic calculators may be used.          ",
            "2": "2  \u00a9 ucles 2016 0620/13/o/n/16  1 \u2018particles moving very slowly  from an area of higher concentration to an area of lower  concentration.\u2019    which process is being described?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air     2 a student mixes 25  cm3 samples of dilute hydrochloric acid with different volumes of aqueous  sodium hydroxide.     in each case, the student measures the change in temperature to test if the reaction is exothermic.    which piece of apparatus is not needed?    burette clock pipette thermometerab c d     ",
            "3": "3  \u00a9 ucles 2016 0620/13/o/n/16 [turn over  3 a solid x is purified in five steps.    the first four steps of the purification are shown in the diagram.    step 1 step 2 step 3 step 4heatsolid xmixture y     in step 5 , how is a pure sample of solid x obtained from mixture y?  a dissolving  b distillation  c evaporating  d filtering     4 an atom has three electron shells. there are three electrons in the outer shell.    how many protons and how many neutrons are in this atom?     protons neutrons  a 13 14  b 13 27  c 14 13  d 21 24    5 boron nitride is a compound of the elements boron and nitrogen.    it has a similar structure to diamond.    what is likely to be a property of boron nitride?  a it conducts electricity.  b it is soluble in water.  c it is used as a lubricant.  d it is very hard.     ",
            "4": "4  \u00a9 ucles 2016 0620/13/o/n/16  6 which row describes the formation of single covalent bonds in methane?    a   atoms share a pair of electrons   both atoms gain a  noble gas electronic structure  b   atoms share a pair of electrons   both atoms have the same number  of electrons in their outer shell  c   electrons are transferred from one  atom to another both atoms gain a  noble gas electronic structure  d   electrons are transferred from one  atom to another both atoms have the same number  of electrons in their outer shell     7 which elements are in the compound baco 3?  a barium and cobalt  b boron, actinium and oxygen  c carbon, oxygen and barium  d oxygen, calcium and boron     8 concentrated aqueous sodium iodide is electrolysed using platinum electrodes.    the solution contains the ions na +, i\u2013, h+ and oh\u2013.    which electrodes are the ions attracted to during this electrolysis?     cathode anode  a h+ and na+ i\u2013 and oh\u2013  b h+ and oh\u2013 i\u2013 and na+  c i\u2013 and na+ h+ and oh\u2013  d i\u2013 and oh\u2013 h+ and na+     ",
            "5": "5  \u00a9 ucles 2016 0620/13/o/n/16 [turn over  9 which apparatus could be used to electroplate an iron nail with copper?    +\u2013a +\u2013b +\u2013cdaqueous copper( ii) sulfate aqueous iron( ii) sulfate+\u2013key = copper sheet = iron nail       10 10  g of ammonium nitrate are added to water at 25  \u00b0c and the mixture stirred. the  ammonium nitrate dissolves and, after one minute, the temperature of the solution is 10  \u00b0c.    which word describes this change?  a endothermic  b exothermic  c neutralisation  d reduction      11 what is always  produced when a fuel is burnt?  a carbon dioxide  b carbon monoxide  c heat energy  d oxides of nitrogen     ",
            "6": "6  \u00a9 ucles 2016 0620/13/o/n/16  12 an experiment x is carried out between a solid and a solution using the apparatus shown.    gas syringe     the volume of gas given off is measured at different times and the results plotted on a graph.    in a second experiment y, the surface area of the solid is increased but all other factors remain  the same.    which graph shows the results of experiments x and y?    a volume of gas time00y xb volume of gas time00y x c volume of gas time00yxd volume of gas time00yx      ",
            "7": "7  \u00a9 ucles 2016 0620/13/o/n/16 [turn over  13 hydrated cobalt( ii) chloride crystals are pink.    when they are heated, they lose water and form blue anhydrous cobalt( ii) chloride.    hydrated cobalt( ii) chloride    anhydrous cobalt( ii) chloride  +  water    a few drops of vinegar were added to anhydrous cobalt( ii) chloride.    there was a colour change from blue to pink.    what does this colour change show about vinegar?  a it contains an acid.  b it contains water.  c it is an alkali.  d it is anhydrous.     14 the equations for three reactions are shown.    1 cuo  +  h 2  \u2192  cu  +  h 2o  2 fe 2o3  +  3co  \u2192  2fe  +  3co 2  3 2h 2  +  o 2  \u2192  2h 2o    which statement about the reactions is not correct?  a in reaction 1, copper( ii) oxide is reduced to copper.  b in reaction 2, carbon monoxide is oxidised to carbon dioxide.  c in reactions 1 and 3, hydrogen is oxidised to water.  d in reaction 2, iron( iii) oxide is oxidised to iron.     ",
            "8": "8  \u00a9 ucles 2016 0620/13/o/n/16  15 part of the periodic table is shown.    xy     which type of oxides do x and y form?     x y  a acidic acidic  b acidic basic  c basic acidic  d basic basic     16 compound t is added to dilute hydrochloric acid and warmed gently.    the mixture gives off a gas which turns acidified aqueous potassium manganate( vii) from purple  to colourless.    a flame test on compound t gives a lilac flame.    what is compound t?  a sodium sulfate  b sodium sulfite  c potassium sulfate  d potassium sulfite     17 acids can react with metal oxides, carbonates and metals.    which reactions produce a gas?     acid with  metal oxide acid with  carbonate acid with  metal   a \u0016 \u0016 \u0016 key  b \u0016 \u001a \u001a \u0016= gas is produced  c \u001a \u0016 \u0016 \u001a= no gas is produced  d \u001a \u0016 \u001a      ",
            "9": "9  \u00a9 ucles 2016 0620/13/o/n/16 [turn over  18 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ystirrer solid x aqueous copper( ii) sulfateexcess of solid xfilter paper heat    what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride sulfuric acid  c copper( ii) oxide sulfuric acid  d sulfur aqueous copper( ii) chloride      19 elements p and q are in the same period of the periodic table.   p is a metal and q is a non-metal.   which statement is correct?  a p has a greater nucleon number than q.  b p is to the right of q in the period.  c q has more electron shells than p.  d q has more protons than p.     20 what is not a property of group i metals?  a they are soft and can be cut with a knife.  b they react when exposed to oxygen in the air.  c they produce an acidic solution when they react with water.  d they react rapidly with water producing hydrogen gas.    ",
            "10": "10  \u00a9 ucles 2016 0620/13/o/n/16  21 a flammable gas needs to be removed from a tank at an industrial plant.    for safety reasons, an inert gas is used.    which gas is suitable?  a argon  b hydrogen  c methane  d oxygen     22 which element is a transition element?     colour of  chloride melting point of  element  / \u00b0c  a orange 113  b orange 1535  c white 113  d white  1535      23 which statement about the element bromine is correct?  a it displaces chlorine from aqueous potassium chloride.  b it has a higher density than chlorine.  c it is a diatomic metal.  d it is a green gas at room temperature.     24 four metals are listed in decreasing order of reactivity.    magnesium  zinc  iron  copper    titanium reacts with acid and cannot be extr acted from its ore by heating with carbon.    where should titanium be placed in the list?  a below copper  b between iron and copper  c between magnesium and zinc  d between zinc and iron ",
            "11": "11  \u00a9 ucles 2016 0620/13/o/n/16 [turn over  25 basic oxides and oxygen are used to convert iron into steel.   which statement is not correct?  a carbon is converted into carbon dioxide.  b silicon is converted into silicon (iv) oxide.  c the basic oxides react with acidic impurities to form slag.  d the oxygen reacts with the iron to produce hematite.    26 a student added dilute hydrochloric acid to four metals and recorded the results.     some of the results are not correct.     results  metal gas given off  1 copper yes  2 iron yes  3 magnesium no  4 zinc yes    which two results are correct?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      27 some properties of aluminium are listed.    1 it conducts heat.  2 it has a low density.  3 it is mechanically strong.  4 it is resistant to corrosion.    which properties make aluminium suitable for making food containers for chilled food products?  a 1, 2 and 4 b 1, 3 and 4 c 1 only d 4 only    ",
            "12": "12  \u00a9 ucles 2016 0620/13/o/n/16  28 the diagram represents the water cycle.    at which stage during the cycle are soluble impurities removed from the water?    seaad rain cevaporatecondense lake riversun b      29 air is a mixture of gases.    which gas is present in the largest amount?  a argon  b carbon dioxide  c nitrogen  d oxygen    30 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0016 \u001a key  b greenhouse gas \u0016 \u0016 \u0016 = true  c present in unpolluted air \u001a \u001a \u001a = false  d produced during respiration \u001a \u0016      ",
            "13": "13  \u00a9 ucles 2016 0620/13/o/n/16 [turn over  31 calcium oxide and ammonium salts ar e used by farmers to treat soils.    why are these two substances added at different times?  a they are both acidic.  b they are both basic.  c they react with each other to produce ammonia.  d they react with each other to produce hydrogen.    32 the chart shows how a gas, g, is formed in four reactions, from glucose or from a solid, s.    gas g solid sglucose heat dilute acidrespirationcombustion     what are the formulae of gas g and solid s?     gas g solid s  a ch 4 ca  b ch 4 caco 3  c co 2 ca  d co 2 caco 3     33 slaked lime is used to neutralise an acidic soil.    how does the ph of the soil change?     from to  a 6 7  b 7 8  c 8 7  d 8 6     ",
            "14": "14  \u00a9 ucles 2016 0620/13/o/n/16  34 which list shows the fractions obtained from distilling petroleum, in order of increasing boiling  point?  a bitumen \u2192 diesel oil \u2192 fuel oil \u2192 lubricating oil  b diesel oil \u2192 gasoline \u2192 naphtha \u2192 kerosene  c gasoline \u2192 naphtha \u2192 kerosene \u2192 diesel oil  d kerosene \u2192 lubricating oil \u2192 naphtha \u2192 refinery gas      35 butane reacts as shown.    butane butene  +  hydrogencatalyst  and heat     what is this type of reaction?  a combustion  b cracking  c polymerisation  d reduction    36 the structure of a compound, x, is shown.    h ch hhhhhch hh hc c c c hh h     to which homologous series does x belong?  a alcohols  b alkanes  c alkenes  d carboxylic acids     ",
            "15": "15  \u00a9 ucles 2016 0620/13/o/n/16 [turn over  37 an organic compound has the following properties.    colour effect on  universal  indicator flammability effect on  aqueous bromine state at room  temperature  colourless none highly flammable decolourises gas    to which homologous series does this organic compound belong?  a alcohols  b alkanes  c alkenes  d carboxylic acids     38 the diagram shows some apparatus.    waterair lock yeast, sugar and wate r     what is made using this apparatus?  a ethane  b ethanoic acid  c ethanol  d ethene      39 which molecule can be polymerised?    h ca h hhh cb h hchh hc hch hh hcd h ch o oc h   ",
            "16": "16  \u00a9 ucles 2016 0620/13/o/n/16  40 ethanol is used as a biofuel.    which equation shows the complete combustion of ethanol?  a c 2h5oh  +  3o 2  \u2192  2co 2  +  2h 2o  b c 2h5oh  +  3o 2  \u2192  2co 2  +  3h 2o  c 2c 2h5oh  +  6o 2  \u2192  4co 2  +  4h 2o  d 2c 2h5oh  +  7o 2  \u2192  4co 2  +  6h 2o     ",
            "17": "17    blank page   \u00a9 ucles 2016 0620/13/o/n/16  ",
            "18": "18    blank page   \u00a9 ucles 2016 0620/13/o/n/16  ",
            "19": "19    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.   cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/13/o/n/16  ",
            "20": "20  \u00a9 ucles 2016 0620/13/o/n/16   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w16_qp_21.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 20 printed pages.  ib16 11_0620_21/6rp  \u00a9 ucles 2016 [turn over       *6942475041* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/21     paper 2 multiple choice (extended)  october/november 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. electronic calculators may be used.   ",
            "2": "2  \u00a9 ucles 2016 0620/21/o/n/16  1 \u2018particles moving very slowly  from an area of higher concentration to an area of lower  concentration.\u2019    which process is being described?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air     2 a student mixes 25  cm3 samples of dilute hydrochloric acid with different volumes of aqueous  sodium hydroxide.     in each case, the student measures the change in temperature to test if the reaction is exothermic.    which piece of apparatus is not needed?    burette clock pipette thermometerab c d      ",
            "3": "3  \u00a9 ucles 2016 0620/21/o/n/16 [turn over  3 information about the solubility of four solids, p, q, r and s, is given in the table.     p q r s  solubility in water dissolves insoluble insoluble dissolves    a student attempted to separate mixtures of these solids using the following method.    1 add the mixture to a beaker of water and stir.  2 filter the mixture.  3 crystallise one of the solids from the filtrate.    which of the following mixtures could not be separated by this method?  a a mixture of p and r  b a mixture of q and p  c a mixture of q and r  d a mixture of r and s      4 the table shows information about atoms of three different elements.    element proton  number nucleon  number number of  protons number of  neutrons number of  electrons  chlorine 17 35 17 w 17  chlorine 17 x 17 19 17  argon y 40 18 22 18  potassium 19 39 19 20 z    what are the values of w, x, y and z?     w x y z  a 18 35 18 19  b 18 36 18 19  c 19 35 19 18  d 19 36 19 18    ",
            "4": "4  \u00a9 ucles 2016 0620/21/o/n/16  5 metal p reacts with non-metal q to form a compound.    which process takes place and which type of compound is formed?     process type of compound  a electrons are transferred from p to q covalent  b electrons are transferred from p to q ionic  c electrons are transferred from q to p covalent  d electrons are transferred from q to p ionic     6 the structure of ethanoic acid is shown.    co ohhch h    which diagram shows the arrangement of outer shell electrons in a molecule of ethanoic acid?    c hh ho ohca c hh ho ohcb c hh ho ohcc c hh ho ohcd      ",
            "5": "5  \u00a9 ucles 2016 0620/21/o/n/16 [turn over  7 x is a solid at room temperature.    x has a high melting point.    solid x conducts electricity.    which diagram shows how the particles are arranged in solid x?    + + + ++ + + +\u2013 + \u2013+ \u2013 +\u2013 + \u2013+ \u2013 +\u2013 + \u2013+ \u2013 +b a d c \u2013 \u2013\u2013 \u2013\u2013 \u2013\u2013 \u2013\u2013      8 benzene is a liquid with molecular formula c 6h6.    ethene is a gas with molecular formula c 2h4.    which statement is correct?  a 1 mole of benzene and 1 mole of ethene contain the same number of atoms.  b 1 mole of benzene and 1 mole of ethene both have a volume of 24  dm3 at room temperature  and pressure.  c both benzene and ethene have the same empirical formula.  d the number of carbon atoms in 0.5 moles of ethene is equal to the avogadro constant.     9 sodium hydrogencarbonate undergoes thermal decomposition as shown.    2nahco 3  \u2192  na 2co 3  +  co 2  +  h 2o    what is the maximum mass of sodium carbonate that can be made from 0.100 moles of sodium hydrogencarbonate?  a 4.15  g b 5.30  g c 10.6  g d 21.2  g     ",
            "6": "6  \u00a9 ucles 2016 0620/21/o/n/16  10 which apparatus could be used to electroplate an iron nail with copper?    +\u2013a +\u2013b +\u2013cdaqueous copper( ii) sulfate aqueous iron( ii) sulfate+\u2013key = copper sheet = iron nail      ",
            "7": "7  \u00a9 ucles 2016 0620/21/o/n/16 [turn over  11 the diagram shows a simple cell.     electrolytemetal y metal xvoltmeter v     which two metals produce the highest reading on the voltmeter?     x y  a magnesium copper  b magnesium iron  c zinc copper  d zinc iron      12 when anhydrous copper( ii) sulfate is added to water a solution is formed and heat is given out.    wateranhydrous copper( ii) sulfatethermometer     which row shows the temperature change and the type of reaction taking place?     temperature change type of reaction  a decrease endothermic  b decrease exothermic  c increase endothermic  d increase exothermic     ",
            "8": "8  \u00a9 ucles 2016 0620/21/o/n/16  13 the energy level diagram for a reaction is shown.    energyproducts reactantsea \u03b4h     which statement is not correct for this energy level diagram?  a it could be the energy level diagram for the reaction when petrol is burnt.  b less energy is released in bond forming than is needed for bond breaking.  c the activation energy, ea, has a positive value.  d the energy change, \u2206h, for the reaction is positive.     ",
            "9": "9  \u00a9 ucles 2016 0620/21/o/n/16 [turn over  14 the rate of reaction between magnesium and excess dilute hydrochloric acid was followed by  measuring the mass of magnesium present at regular time intervals.    two experiments were performed.    both experiments used 0.1  g of magnesium ribbon. the acid in experiment 1 was less  concentrated than in experiment 2.    which graph shows the results of the experiments?    a mass of magnesium time c mass ofmagnesium time1 2 2 1b mass of magnesium time d0 00 00 00 0mass of magnesium time 2 1 1 2       15 which statement explains why coal dust forms an explosive mixture with air?  a coal dust catalyses the explosion.  b coal dust has a large surface area.  c crushing coal increases the concentration of the coal.  d crushing coal increases the temperature of the coal.    ",
            "10": "10  \u00a9 ucles 2016 0620/21/o/n/16  16 the following reversible reaction takes place in a closed vessel at constant temperature.    p(g)  +  q(g)  +  r(g)    s(g)  +  t(g)    when the system has reached equilibrium, more t is added.    after the addition of t, which substances increase in concentration?  a p, q, r and s  b p and q only  c p, q and r only  d s only     17 four ionic half-equations are shown.    1 cu 2+(aq)  +  2e\u2013  \u2192  cu(s)  2 2 i\u2013(aq)  \u2192  i2(aq)  +  2e\u2013  3 fe2+(aq)  \u2192  fe3+(aq)  +  e\u2013  4 c l 2(g)  +  2e\u2013  \u2192  2c l \u2013(aq)    which statement is correct?  a in equation 1, copper( ii) ions are oxidised to copper.  b in equation 2, iodide ions are reduced to iodine.  c in equation 3, iron( ii) ions are oxidised to iron( iii) ions.  d in equation 4, chlorine is oxidised to chloride ions.      18 germanium oxide is a white powder.    germanium oxide reacts with concentrated hydrochloric acid.    germanium oxide reacts with concentrated aqueous sodium hydroxide.    germanium oxide does not dissolve when added to water.    which type of oxide is germanium oxide?  a acidic  b amphoteric  c basic  d neutral     ",
            "11": "11  \u00a9 ucles 2016 0620/21/o/n/16 [turn over  19 hydrogen chloride gas reacts with water to produce an acidic solution. the equation for the  reaction is shown.    hc l  +  h 2o  \u2192  c l \u2013  +  h 3o+    which statement describes what happens during the reaction?  a the chloride ion is formed by accepting an electron from the water.  b the hydrogen chloride loses an electron to form the chloride ion.  c the water accepts a proton from the hydrogen chloride.  d the water donates a proton to the hydrogen chloride.      20 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ystirrer solid x aqueous copper( ii) sulfateexcess of solid xfilter paper heat    what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride sulfuric acid  c copper( ii) oxide sulfuric acid  d sulfur aqueous copper( ii) chloride     ",
            "12": "12  \u00a9 ucles 2016 0620/21/o/n/16  21 information about some silver compounds is shown in the table.    compound formula solubility in water  silver carbonate ag 2co 3 insoluble  silver chloride agc l  insoluble  silver nitrate agno 3 soluble  silver oxide ag 2o insoluble    which equation shows a reaction which cannot  be used to make a silver salt?  a agno 3(aq)  +  hc l (aq)  \u2192  agc l (s)  +  hno 3(aq)  b ag2o(s)  +  2hno 3(aq)  \u2192  2agno 3(aq)  +  h 2o(l)  c ag2co 3(s)  +  2hno 3(aq)  \u2192  2agno 3(aq)  +  h 2o(l)  +  co 2(g)  d 2ag(s)  +  2hc l (aq)  \u2192  2agc l (s)  +  h 2(g)     22 what is not a property of group i metals?  a they are soft and can be cut with a knife.  b they react when exposed to oxygen in the air.  c they produce an acidic solution when they react with water.  d they react rapidly with water producing hydrogen gas.    ",
            "13": "13  \u00a9 ucles 2016 0620/21/o/n/16 [turn over  23 four substances, p, q, r and s, are tested as shown.    test substance  p q r s  dilute hydrochloric  acid added gas given off  which \u2018pops\u2019 with  a lighted splint gas given off  which turns  limewater milky no reaction no reaction  dilute aqueous  sodium hydroxide  added and  warmed gently no reaction no reaction gas given off  which turns  damp, red litmus  paper blue no reaction    what are p, q, r and s?     p q r s  a mg na 2co 3 nh 4cl nac l  b mg nh 4cl na 2co 3 nac l  c mg na 2co 3 nac l nh 4cl  d na2co 3 mg nac l nh 4cl     24 which statement about transition elements and their compounds is correct?  a all the transition elements have an oxidation state of +2 only.  b aqueous solutions of the salts of transition elements are generally coloured.  c transition elements change from metal to non-metal across the period.  d transition elements can act as catalysts but their compounds cannot.    ",
            "14": "14  \u00a9 ucles 2016 0620/21/o/n/16  25 impure iron from the blast furnace is converted to steel as shown.    oxygen impure molten iron     which statement about the process is correct?  a acidic oxides are added to remove alkaline impurities.  b coke is added as a reducing agent.  c oxygen is blown in to oxidise the impure iron.  d the steel produced contains less carbon than the impure iron.      26 the ionic equations represent the reactions between four metals, p, q, r and s, and solutions of  the salts of the same metals.     p  +  q2+ \u2192  no reaction   r  +  p2+ \u2192  r2+  +  p   q  +  s2+ \u2192  q2+  +  s   s  +  p2+ \u2192  s2+  +  p   s  +  r2+ \u2192  s2+  +  r   s  +  q2+ \u2192  no reaction    what is the correct order of reactivity of the metals?     most  least  a p r s q  b q r s p  c q s r p  d s q p r     ",
            "15": "15  \u00a9 ucles 2016 0620/21/o/n/16 [turn over  27 aluminium is extracted by electrolysis.    from which ore is aluminium extracted and at which electrode is aluminium deposited during  electrolysis?     ore electrode  a bauxite negative  b bauxite positive  c cryolite negative  d cryolite positive     28 zinc oxide can be reacted with carbon to produce zinc metal.    which equation for this reaction is correct?  a 2zno  +  c  \u2192  2zn  +  co  b 2zno  +  2c  \u2192  2zn  +  2co 2  c zno  +  c  \u2192  zn  +  co  d zno  +  2c  \u2192  zn  +  2co 2     29 air is a mixture of gases.    which gas is present in the largest amount?  a argon  b carbon dioxide  c nitrogen  d oxygen      30 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0013 \u0017 key  b greenhouse gas \u0013 \u0013 \u0013 = true  c present in unpolluted air \u0017 \u0017 \u0017 = false  d produced during respiration \u0017 \u0013      ",
            "16": "16  \u00a9 ucles 2016 0620/21/o/n/16  31 underwater steel pipes can be protected from corrosion by attaching magnesium blocks to them.    which equation represents the reaction that prevents corrosion?  a fe  \u2192  fe2+  +  2e\u2013  b fe2+  \u2192  fe3+  +  e\u2013  c mg  \u2192  mg2+  +  2e\u2013  d mg2+  +  2e\u2013  \u2192  mg      32 ammonia is manufactured by the haber process. the reaction is exothermic.    n 2(g)  +  3h 2(g)    2nh 3(g) \u2206 h = \u201392  kj / mol    which statement about the haber process is correct?  a the reaction is irreversible and produces only one product.  b the reaction is reversible and produces less ammonia at high pressure.  c the reaction is reversible and produces less ammonia at high temperature.  d the reaction is slow because a catalyst is not used in the haber process.      33 sulfuric acid is manufactured by the contact process.    the most important reaction takes place in the presence of a catalyst.    what are the reactants and the catalyst for this reaction?     reactants catalyst  a sulfur and oxygen vanadium( v) oxide  b sulfur dioxide and oxygen vanadium( v) oxide  c sulfur dioxide and steam iron  d sulfur trioxide and water platinum    ",
            "17": "17  \u00a9 ucles 2016 0620/21/o/n/16 [turn over  34 which box corresponds to limestone?    does limestone contain carbon? yes no yes nodoes limestone burn? does limestone burn? abyes no cd      35 petroleum is an important fossil fuel.    which row correctly describes petroleum?     type of substance composition  a compound mainly hydrocarbons  b compound only hydrogen and carbon  c mixture mainly hydrocarbons  d mixture only hydrogen and carbon    36 butane reacts as shown.    butane butene  +  hydrogencatalyst  and heat     what is this type of reaction?  a combustion  b cracking  c polymerisation  d reduction     ",
            "18": "18  \u00a9 ucles 2016 0620/21/o/n/16  37 substance z has the following characteristics.    1 it burns in an excess of oxygen to form carbon dioxide and water.  2 it is oxidised by air to form a liquid smelling of vinegar. 3 it reacts with carboxylic acids to form esters.    what is substance z?  a ethane  b ethanoic acid  c ethanol  d ethyl ethanoate     38 ethanol is manufactured by the catalytic addition of steam to ethene and by fermentation.    which row shows an advantage and a disadvantage of using the catalytic addition of steam to ethene compared to fermentation?     advantage disadvantage  a fast the product is impure  b fast uses non-renewable materials  c the product is pure slow  d uses renewable materials slow    39 the partial structure of addition polymer x is shown.    cch3 hch ch3cch3 hchch 3    which monomer is used to form polymer x?  a ch 2=ch 2  b ch 3ch=ch 2  c ch 3ch=chch 3  d ch 3ch 2ch=ch 2     ",
            "19": "19    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is  produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/21/o/n/16 40 the diagram shows the partial structure of terylene .    co c co o o oo    from which pair of compounds is it made?    co co ho oh ho oh+ co co ho oh co co ho oh co co ho ohho oh a co ho oh + co ho oh b + c + d     ",
            "20": "20  \u00a9 ucles 2016 0620/21/o/n/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w16_qp_22.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 17 printed pages and 3 blank pages.  ib16 11_0620_22/6rp  \u00a9 ucles 2016 [turn over       *3303892045* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2 multiple choice (extended)  october/november 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 20. electronic calculators may be used.   ",
            "2": "2  \u00a9 ucles 2016 0620/22/o/n/16  1 \u2018particles moving very slowly  from an area of higher concentration to an area of lower  concentration.\u2019    which process is being described?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air     2 a student mixes 25  cm3 samples of dilute hydrochloric acid with different volumes of aqueous  sodium hydroxide.     in each case, the student measures the change in temperature to test if the reaction is exothermic.    which piece of apparatus is not needed?    burette clock pipette thermometerab c d       3 a sample contains a mixture of powdered limestone (calcium carbonate), sugar and wax.    what is the correct way to obtain a pure sample of sugar?  a dissolve the mixture in dilute hydrochloric acid, filter and wash the residue.  b dissolve the mixture in hexane, filter and evaporate the filtrate.  c dissolve the mixture in water, filter and evaporate the filtrate.  d dissolve the mixture in water, filter and wash the residue.     ",
            "3": "3  \u00a9 ucles 2016 0620/22/o/n/16 [turn over  4 the table shows information about four different particles.    particle proton  number nucleon  number number  of protons number  of neutrons number  of electrons na 11 23 11 w 11  na+ 11 23 11 12 x  o 8 16 8 y 8  o2\u2013 8 16 8 8 z    what are the values of w, x, y and z?     w x y z  a 11 10 10 8  b 11 11 8 10  c 12 10 8 10  d 12 11 10 8     5 in which ionic compound do the metal ion and the non-metal ion have the same electronic  structure?  a cao b kbr c mgo d nac l     ",
            "4": "4  \u00a9 ucles 2016 0620/22/o/n/16  6 the structure of methanal is shown.    coh h    which diagram shows the arrangement of outer shell electrons in a molecule of methanal?    co hha co hhb co hhc co hhd       7 iron is a metal. its structure consists of a giant lattice of positive ions in a \u2018sea of electrons\u2019.    which statements about solid iron are correct?    1 iron conducts electricity because the electrons are free to move.  2 iron conducts heat because the positive ions are free to move.  3 iron has a high melting point due to the strong covalent bonds.  4 iron is malleable because the layers of ions can slide over one another.    a 1 and 3 b 1 and 4 c 1 only d 2, 3 and 4     ",
            "5": "5  \u00a9 ucles 2016 0620/22/o/n/16 [turn over  8 which sample contains the greatest number of molecules?  a 4 g of hydrogen  b 18  g of water  c 24  dm3 of oxygen  d 66  g of carbon dioxide      9 sodium carbonate solution reacts with dilute hydrochloric acid. the equation for the reaction is  shown.    na2co 3(aq)  +  2hc l (aq)  \u2192  2nac l (aq)  +  co 2(g)  +  h 2o(l)    excess sodium carbonate is added to 10.0  cm3 of 0.10  mol  / dm3 hydrochloric acid.    which volume of carbon dioxide gas is made?  a 12  cm3 b 24  cm3 c 12  000  cm3 d 24  000  cm3     10 which apparatus could be used to electroplate an iron nail with copper?    +\u2013a +\u2013b +\u2013cdaqueous copper( ii) sulfate aqueous iron( ii) sulfate+\u2013key = copper sheet = iron nail      ",
            "6": "6  \u00a9 ucles 2016 0620/22/o/n/16  11 a student sets up a number of simple cells by putting strips of two different metals into dilute  sulfuric acid.    which cell produces the highest voltage?  a copper and magnesium  b copper and zinc  c iron and copper  d magnesium and zinc     12 which experiment is the most exothermic?     initial  temperature  / \u00b0c final  temperature  / \u00b0c  a 20 5  b 20 32  c 25 12  d 25 34    13 the energy level diagram for a reaction is shown.    reactants products\u03b4hea energy     which row is correct?     sign of \u2206h overall energy change sign of ea  a \u2013 exothermic \u2013  b + endothermic +  c + endothermic \u2013  d \u2013 exothermic +    ",
            "7": "7  \u00a9 ucles 2016 0620/22/o/n/16 [turn over  14 zinc granules are reacted with excess dilute hydrochloric acid.    the volume of hydrogen given off is measured at different times.    the results are shown on the graph, labelled experiment 1.    the results for a second experiment are also shown on the graph, labelled experiment 2.    00 timevolume of hydrogenexperiment 1 experiment 2     which change to the conditions was made in experiment 2?  a the concentration of the hydrochloric acid was decreased.  b the size of the zinc granules was decreased.  c the surface area of the zinc granules was increased.  d the temperature was increased.      15 in an experiment nitric acid is added to excess marble chips and the volume of carbon dioxide  formed is measured.    the experiment is repeated using smaller marble chips. all other conditions remain the same.     which statement about the second experiment is correct?  a the collisions are more frequent and higher energy.  b the collisions are more frequent and the same energy.  c the collisions are the same frequency and the same energy.  d the collisions are the same frequency and higher energy.     ",
            "8": "8  \u00a9 ucles 2016 0620/22/o/n/16  16 at 400  \u00b0c the reaction between hydrogen and iodine reaches an equilibrium. the reaction is  exothermic.     h 2(g)  +  i2(g)    2h i(g) \u2206h = \u201313  kj / mol    which change in conditions would increase the percentage of hydrogen iodide in the equilibrium  mixture?  a a decrease in pressure  b a decrease in temperature  c an increase in pressure  d an increase in temperature      17 chromium forms the compound chromium( iii) sulfate.    what does the ( iii) represent?  a the charge on a sulfate ion  b the number of chromium ions combined with one sulfate ion  c the number of sulfate ions combined with one chromium ion  d the oxidation state of chromium     18 germanium oxide is a white powder.    germanium oxide reacts with concentrated hydrochloric acid.    germanium oxide reacts with concentrated aqueous sodium hydroxide.    germanium oxide does not dissolve when added to water.    which type of oxide is germanium oxide?  a acidic  b amphoteric  c basic  d neutral     ",
            "9": "9  \u00a9 ucles 2016 0620/22/o/n/16 [turn over  19 hydrogen chloride gas reacts with water to produce an acidic solution. the equation for the  reaction is shown.    hc l  +  h 2o  \u2192  c l \u2013  +  h 3o+    which statement describes what happens during the reaction?  a the chloride ion is formed by accepting an electron from the water.  b the hydrogen chloride loses an electron to form the chloride ion.  c the water accepts a proton from the hydrogen chloride.  d the water donates a proton to the hydrogen chloride.      20 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ystirrer solid x aqueous copper( ii) sulfateexcess of solid xfilter paper heat    what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride sulfuric acid  c copper( ii) oxide sulfuric acid  d sulfur aqueous copper( ii) chloride     ",
            "10": "10  \u00a9 ucles 2016 0620/22/o/n/16  21 information about some silver compounds is shown in the table.    compound formula solubility in water  silver carbonate ag 2co 3 insoluble  silver chloride agc l  insoluble  silver nitrate agno 3 soluble  silver oxide ag 2o insoluble    which equation shows a reaction which cannot  be used to make a silver salt?  a agno 3(aq)  +  hc l (aq)  \u2192  agc l (s)  +  hno 3(aq)  b ag2o(s)  +  2hno 3(aq)  \u2192  2agno 3(aq)  +  h 2o(l)  c ag2co 3(s)  +  2hno 3(aq)  \u2192  2agno 3(aq)  +  h 2o(l)  +  co 2(g)  d 2ag(s)  +  2hc l (aq)  \u2192  2agc l (s)  +  h 2(g)     22 what is not a property of group i metals?  a they are soft and can be cut with a knife.  b they react when exposed to oxygen in the air.  c they produce an acidic solution when they react with water.  d they react rapidly with water producing hydrogen gas.    ",
            "11": "11  \u00a9 ucles 2016 0620/22/o/n/16 [turn over  23 aqueous sodium hydroxide was added slowly, until in excess, to separate solutions of  w, x, y and z.    the results are shown.    solution initial observation with   aqueous sodium hydroxide final observation with excess  aqueous sodium hydroxide  w white precipitate formed precipitate dissolves  x white precipitate formed no change  y pale blue precipitate formed no change  z green precipitate formed no change    which row identifies the metal ions in the solutions?     metal ion in  solution w metal ion in  solution x metal ion in  solution y metal ion in  solution z  a aluminium calcium copper( ii) iron( ii)  b aluminium calcium iron( ii) copper( ii)  c aluminium iron( ii) calcium copper( ii)  d calcium aluminium copper( ii) iron( ii)     24 part of the periodic table is shown.    which element has two electrons in its outer shell and three electron shells?    ab c d     25 impurities in iron obtained from the blast furnace include carbon, phosphorus and silicon.    which impurities are removed from the molten iron as gases when it is made into steel?  a carbon and phosphorus  b carbon and silicon  c carbon only  d phosphorus and silicon     ",
            "12": "12  \u00a9 ucles 2016 0620/22/o/n/16  26 y displaces x from its aqueous sulfate.     x does not displace w from its aqueous sulfate.    x displaces z from its aqueous sulfate.    what is the order of reactivity of elements w, x, y and z?     most  reactive  least  reactive  a w x y z  b w y x z  c z x y w  d z w y x      27 which statement about the industrial extraction of aluminium from aluminium oxide is correct?  a aluminium is extracted by heating its oxide with carbon.  b aluminium is extracted using electrolysis and is collected at the anode.  c aluminium is extracted using platinum electrodes and direct current.  d molten cryolite is used as a solvent for aluminium oxide.      28 the alloy brass is a mixture of copper and another metal.    brass is used to make the pins of electrical plugs.    copper is used to make electrical wiring.     which row about brass is correct?     hardness electrical  conductivity other metal  a harder than copper better than copper tin  b harder than copper worse than copper zinc  c softer than copper better than copper tin  d softer than copper worse than copper zinc     ",
            "13": "13  \u00a9 ucles 2016 0620/22/o/n/16 [turn over  29 air is a mixture of gases.    which gas is present in the largest amount?  a argon  b carbon dioxide  c nitrogen  d oxygen     30 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0013 \u0017 key  b greenhouse gas \u0013 \u0013 \u0013 = true  c present in unpolluted air \u0017 \u0017 \u0017 = false  d produced during respiration \u0017 \u0013      31 boats made from steel can be protected from rusting by attaching blocks of a more reactive metal  to the hull of the boat.    hullblock of a more reactive metal     which statement is correct?  a copper is used for the blocks because it does not react with water.  b magnesium is not used for the blocks because it reacts with steel.  c the metal used for the blocks loses electrons more easily than steel.  d this form of protection from rusting is called galvanising.     ",
            "14": "14  \u00a9 ucles 2016 0620/22/o/n/16  32 ammonia is manufactured by the haber process, using an iron catalyst.    n2  +  3h 2    2nh 3    it is not possible to obtain 100% yield.    what is the reason for this?  a a high pressure is used.  b ammonia decomposes at high temperature.  c some of the ammonia is recycled.  d the ammonia reacts with the catalyst.     33 sulfuric acid is manufactured by a series of chemical reactions, one of which is catalysed by  vanadium( v) oxide.    what is the equation for the reaction catalysed by vanadium( v) oxide?  a s  +  o 2  \u2192  so 2  b 2s  +  3o 2  \u2192  2so 3  c 2so 2  +  o 2  \u2192  2so 3  d so 3  +  h 2o  \u2192  h2so 4      34 which substance gives off carbon dioxide on heating?  a lime  b limestone  c limewater  d slaked lime      35 petroleum is separated into fractions.    which statement is not correct?  a each fraction contains a mixture of hydrocarbon molecules.  b fuel oil burns easily and is used as fuel in cars.  c refinery gas is the fraction containing the smallest molecules.  d the fractions are separated depending on their boiling point range.    ",
            "15": "15  \u00a9 ucles 2016 0620/22/o/n/16 [turn over  36 butane reacts as shown.    butane butene  +  hydrogencatalyst  and heat     what is this type of reaction?  a combustion  b cracking  c polymerisation  d reduction      37 substance z has the following characteristics.    1 it burns in an excess of oxygen to form carbon dioxide and water.  2 it is oxidised by air to form a liquid smelling of vinegar.  3 it reacts with carboxylic acids to form esters.    what is substance z?  a ethane  b ethanoic acid  c ethanol  d ethyl ethanoate     38 ethanol is manufactured by the catalytic addition of steam to ethene and by fermentation.    which row shows an advantage and a disadvantage of using the catalytic addition of steam to ethene compared to fermentation?     advantage disadvantage  a fast the product is impure  b fast uses non-renewable materials  c the product is pure slow  d uses renewable materials slow    ",
            "16": "16  \u00a9 ucles 2016 0620/22/o/n/16  39 chloroethene, ch 2=chc l , can be polymerised.    which diagram represents a section of the polymer?    c hh c hc hhc hc hcl cl cl c hc hc hc hc hcl cl cl clcl c hhc hc hhc hhc hcl cl chh c hch c hc hcl cl clcl clc hh c hcl c hhc clab cd       40 terylene  is a synthetic polymer.    which statement about terylene  is not correct?  a it contains amide linkages.  b it contains carbon and oxygen atoms.  c it is made from small units called monomers.  d it is formed by condensation polymerisation.    ",
            "17": "17    blank page   \u00a9 ucles 2016 0620/22/o/n/16 ",
            "18": "18    blank page   \u00a9 ucles 2016 0620/22/o/n/16  ",
            "19": "19    blank page     permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is  produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/22/o/n/16  ",
            "20": "20  \u00a9 ucles 2016 0620/22/o/n/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w16_qp_23.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 16 printed pages.  ib16 11_0620_23/6rp  \u00a9 ucles 2016 [turn over       *0838065749* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/23     paper 2 multiple choice (extended)  october/november 2016       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.   ",
            "2": "2  \u00a9 ucles 2016 0620/23/o/n/16  1 \u2018particles moving very slowly  from an area of higher concentration to an area of lower  concentration.\u2019    which process is being described?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air     2 a student mixes 25  cm3 samples of dilute hydrochloric acid with different volumes of aqueous  sodium hydroxide.     in each case, the student measures the change in temperature to test if the reaction is exothermic.    which piece of apparatus is not needed?    burette clock pipette thermometerab c d      ",
            "3": "3  \u00a9 ucles 2016 0620/23/o/n/16 [turn over  3 a solid x is purified in five steps.    the first four steps of the purification are shown in the diagram.    step 1 step 2 step 3 step 4heatsolid xmixture y     in step 5 , how is a pure sample of solid x obtained from mixture y?  a dissolving  b distillation  c evaporating  d filtering     4 an atom has three electron shells. there are three electrons in the outer shell.    how many protons and how many neutrons are in this atom?     protons neutrons  a 13 14  b 13 27  c 14 13  d 21 24     5 ethanol is a liquid at room temperature and boils at 78  \u00b0c.    sodium chloride is a solid at room temperature.    which statement about the bonding in ethanol and sodium chloride is not correct?  a each ethanol molecule is held together by weak covalent bonds.  b the ethanol molecules are held together by weak attractive forces.  c the sodium ions and chloride ions are held together by strong attractive forces.  d the sodium ions and chloride ions are held together in a giant lattice.     ",
            "4": "4  \u00a9 ucles 2016 0620/23/o/n/16  6 the molecules n 2, c2h4, co 2 and ch 3oh all have covalent bonds.    these bonds consist of shared pairs of electrons.    which row gives the total number of shared pairs of electrons in the molecules shown?     molecule total number of shared  pairs of electrons  a n2 2  b c2h4 6  c co 2 2  d ch 3oh 4     7 metals are malleable.    which statement explains why metals are malleable?  a metallic bonding is very strong.  b metals are good conductors of electricity.  c positive metal ions are arranged in a regular lattice structure.  d the layers of positive metal ions can slide over each other.      8 the equation shows the complete combustion of propane.    c 3h8(g)  +  5o 2(g)  \u2192  3co 2(g)  +  4h 2o(l)    which statement is correct?  a 10  cm3 of propane cannot burn if less than 50  cm3 of oxygen is present.  b 10  cm3 of propane would produce 40  cm3 of liquid water.  c 100  cm3 of oxygen would be sufficient to react completely with 20  cm3 of propane.  d this reaction would result in an increase in the volume of gas.      9 sodium hydroxide reacts with sulfuric acid.    the equation for the reaction is shown.    2naoh  +  h 2so 4  \u2192  na 2so 4  +  2h 2o    which volume of 0.4  mol  / dm3 sodium hydroxide reacts with 50.0  cm3 of 0.1  mol  / dm3  sulfuric acid?  a 12.5  cm3 b 25.0  cm3 c 50.0  cm3 d 100.0  cm3    ",
            "5": "5  \u00a9 ucles 2016 0620/23/o/n/16 [turn over  10 which apparatus could be used to electroplate an iron nail with copper?    +\u2013a +\u2013b +\u2013cdaqueous copper( ii) sulfate aqueous iron( ii) sulfate+\u2013key = copper sheet = iron nail       11 the diagram shows two different metal strips dipped into an electrolyte.    v metal strips electrolyte     which pair of metals produces the highest voltage?  a copper and iron  b copper and magnesium  c copper and zinc  d magnesium and iron ",
            "6": "6  \u00a9 ucles 2016 0620/23/o/n/16  12 10  g of ammonium nitrate are added to water at 25  \u00b0c and the mixture stirred. the  ammonium nitrate dissolves and, after one minute, the temperature of the solution is 10  \u00b0c.    which word describes this change?  a endothermic  b exothermic  c neutralisation  d reduction      13 the energy level diagram for a reaction is shown.    energy reactantsproducts e a h      which row is correct?     sign of \u2206 h overall energy change sign of ea  a \u2013 exothermic \u2013  b + endothermic +  c + endothermic \u2013  d + exothermic +    ",
            "7": "7  \u00a9 ucles 2016 0620/23/o/n/16 [turn over  14 an experiment x is carried out between a solid and a solution using the apparatus shown.    gas syringe     the volume of gas given off is measured at different times and the results plotted on a graph.    in a second experiment y, the surface area of the solid is increased but all other factors remain  the same.    which graph shows the results of experiments x and y?    a volume of gas time00y xb volume of gas time00y x c volume of gas time00yxd volume of gas time00yx       15 which change in conditions increases the energy of the particles in a reaction?  a addition of a catalyst  b increase in concentration  c increase in surface area  d increase in temperature    ",
            "8": "8  \u00a9 ucles 2016 0620/23/o/n/16  16 chlorine can be manufactured by the following reaction. the reaction is exothermic.     4hc l (g)  +  o 2(g)    2h 2o(g)  +  2c l 2(g)    which change increases the yield of chlorine at equilibrium?  a adding more hc l (g)  b adding more h 2o(g)  c decreasing the pressure  d increasing the temperature     17 which change represents an oxidation reaction?  a chlorine changes to chlorate( i) ions  b chlorine changes to chloride ions  c copper( ii) ions change to copper  d potassium manganate( vii) ions change to potassium manganate( vi) ions    18 germanium oxide is a white powder.    germanium oxide reacts with concentrated hydrochloric acid.    germanium oxide reacts with concentrated aqueous sodium hydroxide.    germanium oxide does not dissolve when added to water.    which type of oxide is germanium oxide?  a acidic  b amphoteric  c basic  d neutral     19 hydrogen chloride gas reacts with water to produce an acidic solution. the equation for the  reaction is shown.    hc l  +  h 2o  \u2192  c l \u2013  +  h 3o+    which statement describes what happens during the reaction?  a the chloride ion is formed by accepting an electron from the water.  b the hydrogen chloride loses an electron to form the chloride ion.  c the water accepts a proton from the hydrogen chloride.  d the water donates a proton to the hydrogen chloride.   ",
            "9": "9  \u00a9 ucles 2016 0620/23/o/n/16 [turn over  20 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ystirrer solid x aqueous copper( ii) sulfateexcess of solid xfilter paper heat    what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride sulfuric acid  c copper( ii) oxide sulfuric acid  d sulfur aqueous copper( ii) chloride     21 information about some silver compounds is shown in the table.    compound formula solubility in water  silver carbonate ag 2co 3 insoluble  silver chloride agc l  insoluble  silver nitrate agno 3 soluble  silver oxide ag 2o insoluble    which equation shows a reaction which cannot  be used to make a silver salt?  a agno 3(aq)  +  hc l (aq)  \u2192  agc l (s)  +  hno 3(aq)  b ag2o(s)  +  2hno 3(aq)  \u2192  2agno 3(aq)  +  h 2o(l)  c ag2co 3(s)  +  2hno 3(aq)  \u2192  2agno 3(aq)  +  h 2o(l)  +  co 2(g)  d 2ag(s)  +  2hc l (aq)  \u2192  2agc l (s)  +  h 2(g)    ",
            "10": "10  \u00a9 ucles 2016 0620/23/o/n/16  22 what is not a property of group i metals?  a they are soft and can be cut with a knife.  b they react when exposed to oxygen in the air.  c they produce an acidic solution when they react with water.  d they react rapidly with water producing hydrogen gas.      23 compound t is added to dilute hydrochloric acid and warmed gently.    the mixture gives off a gas which turns acidified aqueous potassium manganate( vii) from purple  to colourless.    a flame test on compound t gives a lilac flame.    what is compound t?  a sodium sulfate  b sodium sulfite  c potassium sulfate  d potassium sulfite     24 part of the periodic table is shown.    w zxy     which row correctly describes the properties of elements w, x, y and z?     has variable  oxidation states reacts with  cold water very  unreactive has four  outer shell  electrons  a w y z x  b x w y z  c z w y x  d z y x w     ",
            "11": "11  \u00a9 ucles 2016 0620/23/o/n/16 [turn over  25 basic oxides and oxygen are used to convert iron into steel.   which statement is not correct?  a carbon is converted into carbon dioxide.  b silicon is converted into silicon (iv) oxide.  c the basic oxides react with acidic impurities to form slag.  d the oxygen reacts with the iron to produce hematite.      26 the results of two experiments are given.    1 cobalt displaces manganese from an aqueous solution of a manganese salt.  2 manganese displaces silver from an aqueous solution of a silver salt.    three more experiments are carried out.    3 cobalt is added to an aqueous solution of a silver salt.  4 manganese is added to an aqueous solution of a cobalt salt.  5 silver is added to an aqueous solution of a cobalt salt.    in which experiments does a reaction take place?  a 3 only b 3 and 4 c 4 and 5 d 5 only      27 cryolite, na 3al f6, is added to aluminium oxide in the electrolytic extraction of aluminium.    what is the reason for this?  a to decrease the melting point of the electrolyte  b to protect the anodes  c to produce more aluminium  d to stop the aluminium reacting with air     28 different forms of steel contain different proportions of carbon.    steel p contains a high proportion of carbon.    steel q contains a low proportion of carbon.    which statement is correct?  a p is stronger and more brittle than q.  b p is stronger and less brittle than q.  c p is less strong and more brittle than q.  d p is less strong and less brittle than q. ",
            "12": "12  \u00a9 ucles 2016 0620/23/o/n/16  29 air is a mixture of gases.    which gas is present in the largest amount?  a argon  b carbon dioxide  c nitrogen  d oxygen     30 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0013 \u0017 key  b greenhouse gas \u0013 \u0013 \u0013 = true  c present in unpolluted air \u0017 \u0017 \u0017 = false  d produced during respiration \u0017 \u0013      31 a metal, x, is used to make oil pipelines.    x corrodes in air and water.    x can be protected from corrosion by attaching blocks of element y.    which statement is correct?  a this process is known as galvanising.  b y forms positive ions more readily than x.  c y is an unreactive metal.  d y is an unreactive non-metal.      32 the haber process for the manufacture of ammonia occurs at 450  \u00b0c and 250 atmospheres. the  nitrogen and hydrogen are supplied in a 1:3 ratio by volume. the reaction is exothermic.     n 2(g)  +  3h 2(g)    2nh 3(g) \u2206 h = \u201392  kj / mol    which change causes an increase in the yield of ammonia?  a decreasing the concentration of nitrogen  b decreasing the pressure  c decreasing the temperature  d using equal amounts of the two reactants     ",
            "13": "13  \u00a9 ucles 2016 0620/23/o/n/16 [turn over  33 the following scheme shows four stages in the conversion of sulfur to sulfuric acid.    in which stage is a catalyst used?    oleumair air watersulfursulfur dioxidesulfur trioxide concentrated sulfuricacid concentrated sulfuric acidstage b stage dstage cstage a       34 slaked lime is used to neutralise an acidic soil.    how does the ph of the soil change?     from to  a 6 7  b 7 8  c 8 7  d 8 6      35 which list shows the fractions obtained from distilling petroleum, in order of increasing boiling  point?  a bitumen \u2192 diesel oil \u2192 fuel oil \u2192 lubricating oil  b diesel oil \u2192 gasoline \u2192 naphtha \u2192 kerosene  c gasoline \u2192 naphtha \u2192 kerosene \u2192 diesel oil  d kerosene \u2192 lubricating oil \u2192 naphtha \u2192 refinery gas     ",
            "14": "14  \u00a9 ucles 2016 0620/23/o/n/16  36 butane reacts as shown.    butane butene  +  hydrogencatalyst  and heat     what is this type of reaction?  a combustion  b cracking  c polymerisation  d reduction      37 substance z has the following characteristics.    1 it burns in an excess of oxygen to form carbon dioxide and water.  2 it is oxidised by air to form a liquid smelling of vinegar.  3 it reacts with carboxylic acids to form esters.    what is substance z?  a ethane  b ethanoic acid  c ethanol  d ethyl ethanoate     38 ethanol is manufactured by the catalytic addition of steam to ethene and by fermentation.    which row shows an advantage and a disadvantage of using the catalytic addition of steam to ethene compared to fermentation?     advantage disadvantage  a fast the product is impure  b fast uses non-renewable materials  c the product is pure slow  d uses renewable materials slow    ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to t race copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is  produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2016 0620/23/o/n/16 39 the organic compound shown can be polymerised.    c ch3cl chf     which diagram represents a section of the polymer?    ffch3 c c ccch3hc l cl ha cl fcl c c c chf c h3 ch3 hb hhf c c c cclfc l ch3 ch3c fc h3h c c ccclhc l ch3 fd      40 the partial structure of a polymer is shown.    co c co o n hnh n h    which type of polymer is represented?  a a carbohydrate  b a polyamide  c a polyester  d an addition polymer     ",
            "16": "16  \u00a9 ucles 2016 0620/23/o/n/16   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.)actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w16_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/31   paper 3 theory (core) october/november 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib16 11_0620_31/3rp\u00a9 ucles 2016 *3756670404* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/31/o/n/16 \u00a9 ucles 20161  the diagram shows part of the periodic table. li b alc n o f ne na sip s clar k cah brkr cuzn   answer the following questions using only the elements in the diagram.   each element may be used once, more than once or not at all.  (a)  which element  (i)  has a smaller proton number than lithium,   ...   [1]  (ii)  is formed at the cathode when a dilute solution of sulfuric acid is electrolysed,   ...   [1]  (iii)  has an oxide of the type xo2 which is used to bleach wood pulp,   ...   [1]  (iv)  forms ions which when tested with excess aqueous sodium hydroxide produce a white  precipitate,   ...   [1]  (v)  is extracted from bauxite?   ...   [1]",
            "3": "3 0620/31/o/n/16 \u00a9 ucles 2016 [turn over (b)  mercury has several naturally-occurring isotopes. one of these is shown. hg80204  (i)  what is the meaning of the term isotope ?   .   ...   [2]  (ii)  how many neutrons are there in one atom of the isotope hg80204?   ...   [1]  (iii)  how many protons are there in one atom of the isotope hg80204?   ...   [1]  (iv)  determine the number of electrons in the mercury( ii) ion, hg2+.   ...   [1] [total: 10]",
            "4": "4 0620/31/o/n/16 \u00a9 ucles 20162  the bar charts compare the concentrations of the main ions in two samples of seawater, sample a  and sample b. 20 15 10 50 na+ca2+k+mg2+sio32\u2013cl \u2013hco3\u2013concentration in mg  / dm320 15 10 50 na+ca2+k+mg2+sio32\u2013cl \u2013hco3\u2013sample bconcentration in mg  / dm3sample a  (a)  use the information in the bar charts to answer the following questions.  (i)  describe two differences in the composition of the seawater in sample a and sample b.   .   .   ...   [2]  (ii)  which positive ion has the lowest concentration in sample a?   ...   [1]  (iii)  calculate the mass of sodium ions in 200 cm3 of sample b.   show all your working. [1 dm3 = 1000 cm3] mass = .. mg  [2]  (b)  describe a test for sodium ions.  test  .  result  .. [2]",
            "5": "5 0620/31/o/n/16 \u00a9 ucles 2016 [turn over (c)  river water contains small particles of clay. when these particles are viewed under a microscope  they show a random, jumpy motion even when the water is still.   what name is given to this type of movement?   ..   [1]  (d)  carbon dioxide dissolves in water to form a mixture which contains hydrogencarbonate ions and hydrogen ions. co 2(g)  +  h2o(l)    hco3\u2013(aq)  +  h+(aq)  (i)  what is the meaning of the symbol ?   ...   [1]  (ii)  the solution formed is slightly acidic.   describe how you would use universal indicator paper to determine the ph of this solution.   .   ...   [2]  (iii)  carbon dioxide is a greenhouse gas which causes climate change.   explain how carbon dioxide contributes to climate change.   ...   [1]  (iv)  state the name of one other greenhouse gas and give one source of this gas.  gas  ..  source  . [2] [total: 14]",
            "6": "6 0620/31/o/n/16 \u00a9 ucles 20163  calcium is in group ii of the periodic table.  (a)  draw a diagram to show the electronic structure of an atom of calcium. [2]  (b)  calcium is manufactured by the electrolysis of molten calcium chloride.   complete the boxes in the diagram to show the  \u2022 anode,  \u2022 cathode,  \u2022 electrolyte. +\u2212 calciu m forming [2]  (c)  calcium reacts with water to form calcium hydroxide and a gas which \u2018pops\u2019 with a lighted  splint.   complete the chemical equation for this reaction. ca  +  ...h2o  \u2192  ca(oh)2  +  ... [2]",
            "7": "7 0620/31/o/n/16 \u00a9 ucles 2016 [turn over (d)  describe the manufacture and uses of lime (calcium oxide).   include at least one relevant word equation relating to the manufacture or use of lime.                  ..   [4] [total: 10]",
            "8": "8 0620/31/o/n/16 \u00a9 ucles 20164  a porous pot has tiny holes in its walls which allow gases to move in or out of the pot.   a teacher filled a porous pot with green chlorine gas. the teacher then placed the pot in a large jar  of air. after 10 minutes, a green colour was seen outside the porous pot. chlorine gasair porous pot at the start after 10 minutes  (a)  use the kinetic particle model of matter to explain this observation.               ..   [3]  (b)  a porous barrier can be used to separate uranium fluoride molecules containing different isotopes of uranium.  (i)  state the main use of the radioactive isotope  235u.   ...   [1]  (ii)  give one medical use of radioactive isotopes.   ...   [1]  (iii)  the accurate relative atomic mass of uranium is 238.03.   define the term relative atomic mass .   .   ...   [2]",
            "9": "9 0620/31/o/n/16 \u00a9 ucles 2016 [turn over (c)  chlorine reacts with potassium bromide to form bromine and potassium chloride.  (i)  complete the chemical equation for this reaction. ...  +  2kbr  \u2192  br2  +  ...kc l [2]  (ii)  give one use of chlorine.   ...   [1]  (iii)  chlorine forms an oxide with the formula cl 2o7.   is this oxide an acidic or a basic oxide?   explain your answer.   .   ...   [1]  (iv)  a teacher heated a test-tube containing anhydrous copper( ii) chloride. a piece of damp  litmus paper was placed at the top of the test-tube. heatlitmus paper anhydrous copper( ii) chloride   the anhydrous copper( ii) chloride decomposed and chlorine was formed.   describe the colour change of the litmus paper.   ...   [1] [total: 12]",
            "10": "10 0620/31/o/n/16 \u00a9 ucles 20165  the table shows the properties of some steels. steelpercentage of carbon in the steelrelative strengthmelting point range / \u00b0cease of corrosion a 1.0 8.0 1430\u20131460 corrodes easily b 0.50 6.5 1430\u20131450 corrodes fairly easily c 0.25 5.0 1410\u20131430 corrodes fairly easily d 0.10 4.0 1440\u20131450 resistant to corrosion  (a)  use the information in the table to answer the following questions.  (i)  what is the relationship between the percentage of carbon in the steel and its strength?   ...   [1]  (ii)  state whether there is a relationship between the percentage of carbon in the steel and its  melting point range.   explain your answer.   .   ...   [1]  (iii)  which steel would be best to use for making a bicycle chain?   explain your answer.   .   ...   [1]  (b)  steel is an alloy.   which one of the diagrams best represents an alloy?   draw a ring around the correct answer. crfefefe fefe crfeni fefefefe fe nife crni afefefefe ninininife crcrcrcr fefefefecr bfefefefe fefefefefe fefefefe fefefefefe cninininini dninininininininini nininini [1]",
            "11": "11 0620/31/o/n/16 \u00a9 ucles 2016 [turn over (c)  high voltage electricity cables are made from aluminium with a steel core.  (i)  apart from conducting electricity, what is the purpose of the steel core?   ...   [1]  (ii)  aluminium is a good electrical conductor.   give one other use of aluminium and state a property of aluminium which makes it suitable  for this use.  use  ..  property  .. [2]  (d)  aluminium powder reacts with powdered iron( iii) oxide. the equation for this reaction is shown. 2al  +  fe2o3  \u2192  al 2o3  +  2fe  (i)  which substance is oxidised in this reaction?   explain your answer.   .   ...   [2]  (ii)  the energy level diagram for this reaction is shown. energy2al  +  fe2o3 al 2o3  +  2f e   is this reaction exothermic or endothermic?   explain your answer.   .   ...   [1] [total: 10]",
            "12": "12 0620/31/o/n/16 \u00a9 ucles 20166 (a)  describe the characteristic properties of acids.   in your answer you should refer to the reactions of acids with metals, bases, carbonates and  indicators.                        ..   [5]  (b)  the table shows some properties of the first five members of the carboxylic acid homologous series. acidmolecular formulamelting point / \u00b0cboiling point / \u00b0cdensity in g / cm3 methanoic acid ch2o2 8 101 1.22 ethanoic acid c2h4o2 17 118 1.05 propanoic acid c3h6o2 \u201321 141 0.99 butanoic acid c4h8o2 \u20135 164 0.96 pentanoic acid c5h10o2 \u201334 0.93  (i)  how does the density of the carboxylic acids vary with the number of carbon atoms in the molecule?   ...   [1]  (ii)  suggest a value for the boiling point of pentanoic acid.   ...   [1]  (iii)  determine the state of ethanoic acid at 15 \u00b0c.   explain your answer.   .   ...   [2]",
            "13": "13 0620/31/o/n/16 \u00a9 ucles 2016 [turn over (iv)  draw the structure of the functional group present in carboxylic acids.   show all of the atoms and all of the bonds. [1]  (v)  calculate the relative molecular mass of butanoic acid.   show all your working. [2]  (c)  identify the following as either physical changes or chemical changes by writing either \u2018physical\u2019  or \u2018chemical\u2019 in the spaces provided.   the condensation of ethanoic acid vapour to liquid ethanoic acid is a . change.  the reaction of sodium with ethanoic acid is a . change.  the dissolving of a salt in water is a . change. [2] [total: 14]",
            "14": "14 0620/31/o/n/16 \u00a9 ucles 20167  the diagram shows the changes of state when sulfur is heated. solid sulfuraliquid sulfursulfur vapourb  (a)  give the names of the changes of state labelled a and b.  a    b   [2]  (b)  describe the arrangement and motion of the particles in sulfur vapour.  arrangement  ..  motion   [2]  (c)  give one use of sulfur.   ..   [1]  (d)  some compounds of sulfur are found in coal.   explain why the presence of sulfur in coal has an adverse effect on human health when the  coal is burnt.      ..   [2]",
            "15": "15 0620/31/o/n/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (e)  one of the compounds of sulfur in coal is thiophene.   the structure of thiophene is shown. c c c c sh hh h  (i)  determine the formula of thiophene.   ...   [1]  (ii)  thiophene can be made in the laboratory by heating ethyne, c2h2, with hydrogen sulfide,  h2s, in the presence of a catalyst.   what is the purpose of the catalyst?   ...   [1]  (iii)  when 2.6 g of ethyne react with excess hydrogen sulfide, 4.2 g of thiophene are formed.   calculate the mass of thiophene formed when 15.6 g of ethyne react with excess hydrogen  sulfide. [1] [total: 10]",
            "16": "16 0620/31/o/n/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi v ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w16_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 20.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/32   paper 3 theory (core) october/november 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 17 printed pages and 3 blank pages. [turn overib16 11_0620_32/3rp\u00a9 ucles 2016 *6390893468* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/o/n/16 \u00a9 ucles 20161  the diagram shows part of the periodic table. li c n o f nehe na ar k ca cuni fe agznalh   answer the following questions using only the elements in the diagram.   each element may be used once, more than once or not at all.  (a)  which element  (i)  gives a lilac colour in a flame test,   ...   [1]  (ii)  is a pinkish-brown metal,   ...   [1]  (iii)  can exist in at least two different solid forms,   ...   [1]  (iv)  has a full outer electron shell containing two electrons,   ...   [1]  (v)  is extracted from hematite?   ...   [1]",
            "3": "3 0620/32/o/n/16 \u00a9 ucles 2016 [turn over (b)  silver has two naturally occurring isotopes. ag47107     and     ag47109   complete the table to show the number of protons, electrons and neutrons in these two  isotopes. ag47107ag47109 number of protons number of electrons number of neutrons [3] [total: 8]",
            "4": "4 0620/32/o/n/16 \u00a9 ucles 20162  the bar charts compare the concentrations of ions in two samples of water, sample a and sample b. 20 15 10 50 na+ca2+k+mg2+sio32\u2013cl \u2013hco3\u2013sample aconcentration in mg  / dm320 15 10 50 na+ca2+k+mg2+sio32\u2013cl \u2013hco3\u2013sample bconcentration in mg  / dm3  (a)  use the information in the bar charts to answer the following questions.  (i)  describe two differences in the composition of sample a and sample b.   .   .   ...   [2]  (ii)  which positive ion has the lowest concentration in sample b?   ...   [1]  (iii)  calculate the mass of chloride ions present in 100 cm3 of sample b.   show all your working. [1 dm3 = 1000 cm3] mass = .. mg  [2]  (b)  describe a test for chloride ions.  test  .  result  .. [2]",
            "5": "5 0620/32/o/n/16 \u00a9 ucles 2016 [turn over (c)  river water contains small particles of clay.   these particles show brownian motion.   which one of these statements best describes brownian motion?   tick one box.  the diffusion of gases  the random movement of particles in a suspension  the downward movement of particles in a suspension [1]  (d)  silicon in river water comes from silicate rocks. some of these contain silicon( iv) oxide.   explain why silicon( iv) oxide is an acidic oxide.   ..   [1]",
            "6": "6 0620/32/o/n/16 \u00a9 ucles 2016 (e)  river water contains dissolved oxygen.   the graph shows how the concentration of dissolved oxygen changes with temperature. 15 10 5 0 0 5 10 15 temperature  / \u00b0c20 25 30concentration of dissolvedoxygen in mg  / dm3  (i)  describe how the concentration of dissolved oxygen changes with temperature.   ...   [1]  (ii)  determine the concentration of oxygen present in the water at 10 \u00b0c.   ...   [1]  (iii)  suggest how the rate of corrosion of iron water pipes changes with temperature.   explain your answer.   .   ...   [1]  (f)  describe how water is treated to make it suitable to drink.      ..   [2]  (g)  oxides of nitrogen are common pollutants in the air.  (i)  state one source of oxides of nitrogen in the air.   ...   [1]  (ii)  state one adverse effect of oxides of nitrogen on health.   ...   [1] [total: 16]",
            "7": "7 0620/32/o/n/16 \u00a9 ucles 2016 [turn over3  iron is a metal.  (a)  the equation for the reaction of iron with steam is shown. 3fe  +  4h2o  \u2192  fe3o4  +  4h2   which substance is reduced in this reaction?   explain your answer.      ..   [2]  (b)  iron is extracted by heating iron ore with carbon in a blast furnace.  (i)  what is the meaning of the term ore?   ...   [1]  (ii)  air is blown into the blast furnace.   what is the purpose of this air?   ...   [1]  (iii)  the impurities in the iron ore are removed as slag.   which one of the following is slag?   tick one box.  iron(ii) oxide  calcium silicate  calcium carbonate  coke [1]",
            "8": "8 0620/32/o/n/16 \u00a9 ucles 2016 (iv)  slag is less dense than iron.   the diagram shows a blast furnace used to extract iron.   on the diagram, write the letter s to show where the slag is removed. mixture including iron ore [1]  (c)  iron from the blast furnace contains impurities.   the diagram shows a converter used to make steel from iron. molten iron from blast furnace   describe how iron is converted into steel.   in your answer  \u2022  describe the impurities present,  \u2022  describe how the impurities are removed,  \u2022  include a relevant word equation.                  ..   [4] [total: 10]",
            "9": "9 0620/32/o/n/16 \u00a9 ucles 2016 [turn over4  methyl orange and methyl red are both dyes which can be used as indicators.  (a)  the actual value for the melting point of methyl red is 180 \u00b0c.   a chemist prepares a sample of methyl red and finds that it melts over the range 173 \u00b0c to  177 \u00b0c.   suggest why the melting point of this sample was different from the actual value.   ..   [1]  (b)  a concentrated solution of methyl orange was placed at the bottom of a beaker containing an  organic solvent.   after 5 hours, the orange colour had spread throughout the solvent. at the start after 5 hoursmethyl orangeorganic solvent   use the kinetic particle model of matter to explain this observation.            ..   [3]  (c)  methyl orange is used as an indicator.   what colour is methyl orange when placed in dilute sulfuric acid?   ..   [1]",
            "10": "10 0620/32/o/n/16 \u00a9 ucles 2016 (d)  sulfuric acid can be used to prepare copper( ii) sulfate from copper( ii) oxide.  (i)  complete the general word equation for this reaction. metal oxide  +  acid  \u2192  ..  +  .. [2]  (ii)  sulfuric acid is added to excess copper( ii) oxide. the mixture is heated and the unreacted  copper( ii) oxide is removed.   suggest how the unreacted copper( ii) oxide is removed.   ...   [1]  (iii)  put statements a to e about the preparation of pure dry crystals of copper( ii) sulfate from  copper( ii) sulfate solution in the correct order.  a  the crystals are filtered off.  b  the heating is stopped when the point of crystallisation is reached.  c  the mixture is left to form crystals.  d  the crystals are dried with filter paper.  e  the solution is heated gently. correct order [2] [total: 10]",
            "11": "11 0620/32/o/n/16 \u00a9 ucles 2016 [turn over5  cement is made by heating clay with limestone. some of the limestone (calcium carbonate) breaks  down to form calcium oxide and a gas which turns limewater milky.  (a) (i)  complete the chemical equation for this reaction. caco3  \u2192  ...  +  ... [2]  (ii)  what type of chemical reaction is this?   ...   [1]  (iii)  determine the relative formula mass of calcium carbonate. show all your working. [2]  (b)  concrete is a mixture of cement, sand, water and small stones.   calcium carbonate is a compound, but concrete is a mixture.   state two differences between a compound and a mixture.            ..   [2]",
            "12": "12 0620/32/o/n/16 \u00a9 ucles 2016 (c)  reinforced concrete contains steel bars within the concrete. concrete steel bars   some properties of concrete and steel are shown in the table. relative strengthrelative expansion when heatedrelative heat conductivitycost concrete 60 12 1.5 low steel 250 12 60.0 high   use the information in the table to suggest why concrete must be reinforced with steel when it  is used to make bridges.      ..   [1]  (d)  if reinforced concrete becomes cracked, liquids and gases can reach the steel bars. the steel bars rust.   which two substances are needed for steel to rust?  ...  and   .   [2] [total: 10]",
            "13": "13 0620/32/o/n/16 \u00a9 ucles 2016 [turn over6  petroleum can be separated into useful hydrocarbon fractions by fractional distillation.  (a) (i)  explain the term hydrocarbon fraction .  hydrocarbon    fraction     . [2]  (ii)  state one use for each of the following hydrocarbon fractions.  naphtha  ...  kerosene  . [2]  (b)  organic compounds can be grouped into different homologous series.   explain the term homologous series  by referring to alkenes.                  ..   [4]",
            "14": "14 0620/32/o/n/16 \u00a9 ucles 2016 (c)  the table shows some information about alkenes. alkene formuladensity of liquid alkene in g / cm3melting point / \u00b0cboiling point / \u00b0c ethene c2h4 0.568 \u2013169 \u2013104 propene c3h6 0.610 \u2013185 \u201347 butene c4h8 0.626 \u2013185 \u20136 pentene c5h10 0.640 \u2013165 +30 hexene c6h12 0.673 \u2013140  (i)  a student predicts that the density of the liquid alkenes increases as the number of carbon  atoms increases.   describe whether the data in the table support this prediction.   .   ...   [1]  (ii)  predict the boiling point of hexene.   ...   [1]  (iii)  deduce the state of pentene at \u2013 60 \u00b0c.   explain your answer.   .   ...   [2]  (d)  draw the structure of ethene. show all of the atoms and all of the bonds. [1]  (e)  alkenes are manufactured by cracking.   when tetradecane, c14h30, is cracked the products are ethene, an alkene with four carbon  atoms and an alkane.   complete the chemical equation for this reaction. c14h30  \u2192  c2h4  +  ...  +  ... [2] [total: 15]",
            "15": "15 0620/32/o/n/16 \u00a9 ucles 2016 [turn over7  the graph shows how the temperature of sodium changes when it is heated at a constant rate in  an atmosphere of argon. temperature timeabcde  (a)  suggest why the sodium is heated in argon and not in air.   ..   [1]  (b)  which part of the graph above represents the boiling point of sodium?   tick one box.  a\u2013b  b\u2013c  c\u2013d  d\u2013e [1]  (c) (i)  describe two differences in the general properties of a liquid and a gas.   .   .   ...   [2]  (ii)  describe the arrangement and motion of the particles in a liquid.  arrangement  ...  motion  . [2]",
            "16": "16 0620/32/o/n/16 \u00a9 ucles 2016 (d)  niobium is a transition element. sodium is an element in group i of the periodic table.  (i)  describe two properties of niobium which are different from sodium.   .   ...   [2]  (ii)  the structure of niobium chloride is shown. nb nb cl cl cl clcl clcl cl cl cl   determine the formula of niobium chloride.   ...   [1]  (iii)  niobium chloride is a covalent molecule.   predict two physical properties of niobium chloride.   .   ...   [2] [total: 11]",
            "17": "17 0620/32/o/n/16 \u00a9 ucles 2016blank page",
            "18": "18 0620/32/o/n/16 \u00a9 ucles 2016blank page",
            "19": "19 0620/32/o/n/16 \u00a9 ucles 2016blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. ",
            "20": "20 0620/32/o/n/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi v ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w16_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/33   paper 3 theory (core) october/november 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib16 11_0620_33/2rp\u00a9 ucles 2016 *5104803745* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/33/o/n/16 \u00a9 ucles 20161  the diagram shows part of the periodic table. li c n o f ne si geclar ti cr brkr sn ixecuznh   answer the following questions using only the elements in the diagram.   each element may be used once, more than once or not at all.  (a)  which element  (i)  forms 21% of the air,   ...   [1]  (ii)  reacts with water to form a solution which turns litmus paper from red to blue,   ...   [1]  (iii)  forms ions of type x3+ which when tested with aqueous sodium hydroxide produce a green  precipitate,   ...   [1]  (iv)  is a red-brown liquid at room temperature and pressure,   ...   [1]  (v)  is a noble gas with only three complete electron shells?   ...   [1]",
            "3": "3 0620/33/o/n/16 \u00a9 ucles 2016 [turn over (b)  the table gives some information about the properties of four metals. metaldensity in g / cm3relative strengthresistance to corrosionrelative electrical conductivitymelting point / \u00b0c chromium 7.2 8 very good 8 1857 copper 8.9 30 good 60 1283 iron 7.9 21 poor 10 1535 titanium 4.5 23 very good 2 1660   which one of these metals is most suitable for making the frame of an aircraft?   explain your answer using information from the table.            ..   [3] [total: 8]",
            "4": "4 0620/33/o/n/16 \u00a9 ucles 20162  a scientist analysed the substances present in a 1 dm3 sample of river water in an agricultural area.   the table shows the mass of each ion dissolved in the 1 dm3 sample. name of ion formula of ion mass / g calcium ca2+1.2 chloride cl \u20130.1 hydrogencarbonate hco3\u20131.0 magnesium mg2+0.5 nitrate no3\u20131.0 sodium na+ so42\u20130.5 phosphate po43\u20131.2 total 6.0  (a) (i)  which negative ion has the highest concentration, in g / dm3, in this sample of water?   ...   [1]  (ii)  give the name of the ion with the formula so42\u2013.   ...   [1]  (iii)  calculate the mass of sodium ions in 1 dm3 of this river water.   ...   [1]  (b)  describe a test for nitrate ions.  test  .     result  .. [3]",
            "5": "5 0620/33/o/n/16 \u00a9 ucles 2016 [turn over (c)  the sample of river water also contains insoluble materials such as clay and the remains of  dead animals and plants.  (i)  what method could be used to separate insoluble materials from river water?   ...   [1]  (ii)  some of the remains of dead animals and plants contain food materials.   which two of the following substances are constituents of food?   tick two boxes.  alkane  carbohydrate  graphite  protein [1]  (iii)  particles of clay suspended in river water show brownian motion.   describe the movement of these particles.   ...   [1]  (d)  most of the nitrate ions in river water come from fertilisers.  (i)  explain why farmers use fertilisers.   .   ...   [2]  (ii)  ammonium nitrate is a fertiliser.   ammonium nitrate reacts with calcium hydroxide.  ammonium nitrate  +  calcium hydroxide  \u2192  calcium nitrate  +  ammonia  +  water   explain why adding calcium hydroxide to the soil at the same time as nitrate fertilisers  results in loss of nitrogen from the soil.   .   ...   [2] [total: 13]",
            "6": "6 0620/33/o/n/16 \u00a9 ucles 20163  ethanol can be manufactured by fermentation and from ethene.  (a)  describe the manufacture of ethanol by fermentation and from ethene.   in your answer include  \u2022  the essential conditions required for each reaction,  \u2022  one or more relevant word equations.                  ..   [5]  (b)  the table shows some properties of different alcohols. alcohol formulamelting point / \u00b0cboiling point / \u00b0crelative viscosity methanol ch4o \u201394 65 0.54 ethanol c2h6o \u2013117 79 1.08 propanol c3h8o \u2013126 98 1.94 butanol c4h10o \u201389 117 2.54 pentanol c5h12o \u201379 3.47  (i)  deduce the state of methanol at room temperature.   explain your answer.   .   ...   [2]  (ii)  predict the boiling point of pentanol.   ...   [1]  (iii)  describe how the relative viscosity changes with the number of carbon atoms in the  alcohol.   ...   [1]",
            "7": "7 0620/33/o/n/16 \u00a9 ucles 2016 [turn over (c) (i)  draw the structure of ethanol. show all of the atoms and all of the bonds. [2]  (ii)  give one major use of ethanol.   ...   [1] [total: 12]",
            "8": "8 0620/33/o/n/16 \u00a9 ucles 20164 jelly is a mixture of water and protein chains. water protein chains  (a)  a crystal of blue dye was placed on top of some jelly.   after 30 minutes some of the blue colour could be seen in the jelly.   after 1 day the blue colour had spread out further into the jelly. at the start after 30 minutes after 1 daydishcrystal of blue dye jelly   use the kinetic particle model of matter to explain these observations.            ..   [3]  (b)  the diagram shows the colour changes of the indicator bromocresol green at different ph  values. green increasing phblue yellowph 3.8 ph 1.0 ph 5.4 ph 8.0   predict the colour of bromocresol green  in pure water,  .  in a strongly acidic solution.  ... [2]",
            "9": "9 0620/33/o/n/16 \u00a9 ucles 2016 [turn over (c)  the concentration of an alkali can be found by titrating it with an acid using the apparatus  shown. acid ab alkali  (i)  state the names of the pieces of glassware labelled a and b.  a  .  b  . [2]  (ii)  describe how you would carry out a titration using the apparatus shown. acid alkali   .   .   .   .   .   ...   [3] [total: 10]",
            "10": "10 0620/33/o/n/16 \u00a9 ucles 20165  lime (calcium oxide) is made by heating limestone (calcium carbonate). caco3(s)    cao(s)  +  co2(g)  (a) (i)  is this reaction exothermic or endothermic?   explain your answer.   .   ...   [1]  (ii)  the reaction is reversible.   what information in the equation shows that this reaction is reversible?   ...   [1]  (b)  the diagram shows a furnace for making lime. mixture of limeston e and coke  (i)  on the diagram, write  \u2022  the letter c to show where the waste gases exit the furnace,  \u2022 the letter l to show where the lime is removed from the furnace. [2]  (ii)  suggest a reason for adding coke (carbon) to the furnace.   ...   [1]  (c)  explain why farmers use lime to treat acidic soils.      ..   [2]",
            "11": "11 0620/33/o/n/16 \u00a9 ucles 2016 [turn over (d)  limestone is used to manufacture cement. the limestone is mixed with clay and heated to  1500 \u00b0c. it is then mixed with calcium sulfate and crushed.  (i)  describe the test for sulfate ions.  test  ..  result  ... [2]  (ii)  concrete is a mixture of cement, silicates and water. part of the structure of a silicate is shown. = silicon atom = oxygen atomkey   deduce the formula for this silicate.   ...   [1]",
            "12": "12 0620/33/o/n/16 \u00a9 ucles 2016 (e)  concrete contains small amounts of calcium oxide.   this can react with rainwater to form calcium hydroxide.  (i)  calcium hydroxide is strongly alkaline.   what is the most likely ph of a strongly alkaline solution?   draw a ring around the correct answer. ph 2               ph 6               ph 7               ph 12 [1]  (ii)  the calcium hydroxide on the surface of a piece of concrete reacts with carbon dioxide in  the air.   complete the chemical equation for this reaction. ca(oh)2  +  co2  \u2192  caco3  +  ... [1]  (iii)  limewater is an aqueous solution of calcium hydroxide. a teacher left an open beaker of  limewater in the laboratory.   after a week, the solution in the beaker was ph 7 and a white precipitate was observed.   use the information in (e)(i) and (e)(ii) to help you explain these observations.   .   .   .   .   .   ...   [3] [total: 15]",
            "13": "13 0620/33/o/n/16 \u00a9 ucles 2016 [turn over6  the periodic table is a method of classifying elements.  (a) (i)  in what order are the elements arranged in the periodic table?   ...   [1]  (ii)  how does the character of the elements change from left to right across a period?   ...   [1]  (iii)  describe two trends in the properties of the elements going down group i.   .   .   ...   [2]  (b)  the halogens are a group of elements with diatomic molecules.  (i)  chlorine reacts with an aqueous solution of sodium iodide. cl 2  +  2nai  \u2192  i2  +  2nacl   what colour change would be observed in the solution?  from .  to     [2]  (ii)  astatine, at2, is a halogen.   suggest why astatine does not react with aqueous potassium iodide.   ...   [1]  (c)  chlorine reacts with hydrogen to form hydrogen chloride.  (i)  complete the chemical equation for this reaction. cl 2  +  ...  \u2192  ..hc l [2]  (ii)  draw a diagram to show the electronic structure of a molecule of hydrogen chloride.   show only the outer shell electrons. [2]",
            "14": "14 0620/33/o/n/16 \u00a9 ucles 2016 (iii)  hydrochloric acid reacts with lithium hydroxide.   complete the word equation for this reaction. hydrochloric acid+lithium hydroxide\u2192 + [2] [total: 13]",
            "15": "15 0620/33/o/n/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 7  the diagram shows the changes of state when phosphorus is cooled slowly to room temperature. phosphorus vapouraliquid phosphorussolid phosphorusb  (a)  give the names of the changes of state labelled a and b.  a    b   [2]  (b)  describe the arrangement and motion of the particles in solid phosphorus.  arrangement  ..  motion   [2]  (c)  is phosphorus( v) oxide an acidic oxide or basic oxide?   explain your answer.   ..   [1]  (d)  phosphorus sulfide is a covalent molecule. p p pss sp   predict two properties of phosphorus sulfide.      ..   [2]  (e)  many metal ores contain sulfides.   when zinc sulfide is heated in air the following reaction takes place. zinc sulfide  +  oxygen  \u2192  zinc oxide  +  sulfur dioxide   explain why this reaction may be harmful to the environment.      ..   [2] [total: 9]",
            "16": "16 0620/33/o/n/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi v ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w16_qp_41.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/41   paper 4 theory (extended) october/november 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib16 11_0620_41/3rp\u00a9 ucles 2016 *6396621448* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/41/o/n/16 \u00a9 ucles 20161  the table gives some information about five substances. substancemelting point / \u00b0cboiling point / \u00b0csolubility in waterelectrical conductivity when moltenelectrical conductivity when solid f \u201397 65 very soluble does not conduct does not conduct g 1600 2230 insoluble does not conduct does not conduct h 801 1413 soluble conducts does not conduct i \u201357 126 insoluble does not conduct does not conduct j 1085 2562 insoluble conducts conducts  (a)  which substance in the table has ionic bonding?   ..   [1]  (b)  which substance in the table has a giant covalent structure?   ..   [1]  (c)  name a method you could use to separate a mixture of substance j and water.   ..   [1]  (d)  name a method you could use to obtain substance f from a mixture of substance f and water.   ..   [2]  (e)  describe how you could obtain a solid sample of substance h from a mixture of substance h  and substance g.                  ..   [3]  (f)  substance j is a metal.   describe how substance j is able to conduct electricity when it is a solid.         ..   [2] [total: 10]",
            "3": "3 0620/41/o/n/16 \u00a9 ucles 2016 [turn over2  matter can exist as solid, liquid or gas. the arrows show some changes of state. solid liquid gasb a c  (a)  name the changes of state represented on the diagram.  (i) a  ...   [1]  (ii) b  ...   [1]  (iii) c  ...   [1]  (b)  explain why energy has to be supplied to turn a liquid into a gas.      ..   [1]  (c)  the diagrams represent the same number of particles of a gas in two containers, d and e,  which have different volumes. the two containers are at the same temperature. d e   in which container will the pressure be higher? explain your answer.         ..   [1] [total: 5]",
            "4": "4 0620/41/o/n/16 \u00a9 ucles 20163 (a)  petroleum is a mixture of hydrocarbons. it is separated into useful fractions by fractional  distillation. this can be done using the fractionating column shown. petroleumk l m n o px  (i)  what happens to the petroleum at point x, before it enters the fractionating column?   .   ...   [1]  (ii)  state two ways in which fraction o differs from fraction l.   .   .   ...   [2]  (b)  most of the hydrocarbons obtained from petroleum are alkanes. the alkanes are an homologous series of saturated hydrocarbons with the general formula c nh2n+2.   give two characteristics, other than having the same general formula, of members of an  homologous series.         ..   [2]",
            "5": "5 0620/41/o/n/16 \u00a9 ucles 2016 [turn over (c)  the alkane with the molecular formula c5h12 can exist as a number of structural isomers.   draw the structures of two isomers with the formula c5h12. [2]  (d)  the alkane ethane has the structure shown. h ch hh hch   when a mixture of ethane and chlorine is exposed to ultraviolet light a substitution reaction  takes place.   draw the structure of one organic product from this substitution reaction. [1]",
            "6": "6 0620/41/o/n/16 \u00a9 ucles 2016 (e)  isoprene is a naturally occurring hydrocarbon.  (i)  explain how the name of isoprene suggests that it contains a c=c double bond.   ...   [1]  (ii)  a sample of isoprene had the following composition by mass: c, 88.24%;  h, 11.76%.   calculate the empirical formula of isoprene. show all your working. empirical formula = ..   [3]  (iii)  what additional information would be required to calculate the molecular formula of  isoprene?   ...   [1] [total: 13] 4 (a)  ammonia, nh3, is made by reacting nitrogen with hydrogen in the haber process.  (i)  write a chemical equation for the formation of ammonia in the haber process.   ...   [2]  (ii)  name the raw materials from which nitrogen and hydrogen are obtained.  nitrogen  ...  hydrogen  . [2]  (iii)  state the temperature and pressure used in the haber process. include the units.  temperature    pressure  .. [2]",
            "7": "7 0620/41/o/n/16 \u00a9 ucles 2016 [turn over (b)  ammonia is also made when ammonium carbonate decomposes. (nh4)2co3(s)    2nh3(g)  +  h2o(g)  +  co2(g)   the reaction is reversible and can reach a position of equilibrium.   the graph shows how the yield of ammonia at equilibrium changes with temperature and  pressure. yield of ammonia pressure300  \u00b0c 100  \u00b0c  (i)  what is meant by the term equilibrium  for a reversible reaction?   .   .   ...   [2]  (ii)  using information from the graph, explain whether the reaction is endothermic or  exothermic.   .   ...   [1]  (iii)  state and explain the effect of increasing the pressure on the yield of ammonia in this reaction.   .   .   .   .   ...   [3] [total: 12]",
            "8": "8 0620/41/o/n/16 \u00a9 ucles 20165  copper( ii) sulfate solution was electrolysed using the apparatus shown. copper wir e carbon cathod e copper( ii) sulfate solutio ncarbon anode bubbles of ga s+ \u2013  (a)  a gas was formed at the anode.   identify this gas and give the test for this gas.  gas  .  test  .  result of test  ... [3]  (b)  during electrolysis, electricity passes through the copper( ii) sulfate solution.   solid copper( ii) sulfate does not conduct electricity.   explain both  of these statements.               ..   [3]",
            "9": "9 0620/41/o/n/16 \u00a9 ucles 2016 [turn over (c)  the electrolysis was repeated using copper electrodes in place of carbon electrodes. the ionic  half-equations for the reactions at the two electrodes are shown.  anode cu(s)  \u2192  cu2+(aq)  +  2e\u2013  cathode cu2+(aq)  +  2e\u2013  \u2192  cu(s)  (i)  which species is reduced during the electrolysis? explain your answer.   .   .   ...   [2]  (ii)  the masses of the copper electrodes changed during the electrolysis.   state how and explain why the masses of the two copper electrodes changed.   use the ionic half-equations to help you.   .   .   .   .   .   .   ...   [3]  (iii)  explain why, during the electrolysis, the colour of the copper( ii) sulfate solution does not  change.   .   .   ...   [1] [total: 12]",
            "10": "10 0620/41/o/n/16 \u00a9 ucles 20166  nylon, terylene  and proteins are all polymers.  (a)  what is a polymer?         ..   [2]  (b)  proteins are natural polymers. proteins are biodegradable.  (i)  name the type of linkage in proteins.   ...   [1]  (ii)  what is meant by the term biodegradable?   .   .   ...   [2]  (iii)  name another natural polymer.   ...   [1]",
            "11": "11 0620/41/o/n/16 \u00a9 ucles 2016 [turn over (c)  nylon and terylene  are synthetic polymers.   the repeat unit of nylon can be shown as co co n hn h   terylene  can be made from the monomers shown. ho o h co co o h ho   draw a diagram to show the repeat unit of terylene . [3] [total: 9]",
            "12": "12 0620/41/o/n/16 \u00a9 ucles 20167  calcium chloride can be made by reacting calcium carbonate with hydrochloric acid. caco3(s)  +  2hcl (aq)  \u2192  cacl 2(aq)  +  h2o(l)  +  co2(g)   an excess of calcium carbonate was added to 50.0 cm3 of 0.500 mol / dm3 hydrochloric acid. the  solution was filtered to remove the excess calcium carbonate.  (a)  how many moles of hc l were used in this reaction? . mol  [2]  (b)  deduce the number of moles of carbon dioxide gas made in this reaction. . mol  [1]  (c)  calculate the mass of carbon dioxide made in this reaction.  g  [2]  (d)  calculate the volume, in dm3, of carbon dioxide made in this reaction at room temperature and  pressure (r.t.p.).  dm3  [1] [total: 6]",
            "13": "13 0620/41/o/n/16 \u00a9 ucles 2016 [turn overquestion 8 starts on the next page.",
            "14": "14 0620/41/o/n/16 \u00a9 ucles 20168  magnesium carbonate reacts with dilute hydrochloric acid. mgco3(s)  +  2hcl (aq)  \u2192  mgcl 2(aq)  +  h2o(l)  +  co2(g)   an excess of magnesium carbonate pieces was added to dilute hydrochloric acid. the apparatus in  the diagram was used to measure the volume of gas produced. the total volume of gas collected was recorded every 20 seconds. water troughmagnesium carbonate piecesinverted measuring cylinde r dilute hydrochlori c acidbung conical flask  (a)  the results obtained are shown on the graph. 120 100 80 604020 0 0 100 200 300 time  / s400 500total volume of gas collected / cm3  (i)  describe how the rate of this reaction changed during the reaction. explain why the rate  changed in this way.   .   .   .   .   ...   [4]",
            "15": "15 0620/41/o/n/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (ii)  the experiment was repeated using the same mass of powdered magnesium carbonate  with the same volume and concentration of dilute hydrochloric acid.   explain how the initial rate of reaction and total volume of gas collected would compare to  the first experiment.  initial rate of reaction  ..   .   .  total volume of gas  .   .   . [4]  (b)  a piece of magnesium ribbon was cleaned. the experiment was repeated using this clean magnesium ribbon instead of magnesium carbonate. mg(s)  +  2hcl (aq)  \u2192  mgcl  2(aq)  +  h2(g)   this reaction is exothermic.   the rate of the reaction gradually increased over the first 2 minutes.   explain why the rate of the reaction increased.                     ..   [5] [total: 13]",
            "16": "16 0620/41/o/n/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi v ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w16_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/42   paper 4 theory (extended) october/november 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib16 11_0620_42/4rp\u00a9 ucles 2016 *5182765417* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/o/n/16 \u00a9 ucles 20161  particles behave differently when in different physical states.  (a)  solids have a fixed volume and a definite shape.   gases have no fixed volume and take the shape of the container.   describe the volume and shape of liquids.      ..   [1]  (b)  complete the table to show the separation, arrangement and movement of particles in each  physical state. state separation of particles arrangement of particles movement of particles solid liquid touching one another randomly arranged move over one another gas [6]  (c)  name the following changes of state.  (i)  ice turning into water.   ...   [1]  (ii)  solid carbon dioxide turning directly into gaseous carbon dioxide at room temperature.   ...   [1] [total: 9]",
            "3": "3 0620/42/o/n/16 \u00a9 ucles 2016 [turn over2  this question is about atoms, ions and isotopes.  (a)  define the term nucleon number .      ..   [2]  (b)  give the electronic structure of the following atom and ion.  na  ..  p3\u2013  .. [2]  (c)  state one medical use of radioactive isotopes.   ..   [1]  (d)  what is meant by the term relative atomic mass ?         ..   [2]  (e)  suggest why the relative atomic mass of chlorine is not a whole number.         ..   [2]",
            "4": "4 0620/42/o/n/16 \u00a9 ucles 2016 (f)  aluminium is a metal in group iii.   describe the bonding in aluminium.   include a labelled diagram and any appropriate charges in your answer. [3] [total: 12]",
            "5": "5 0620/42/o/n/16 \u00a9 ucles 2016 [turn over3  clean, dry air contains a small amount of carbon dioxide.  (a)  the percentages of the other gases present in clean, dry air are  shown in the table.   complete the table by inserting the names of these gases. name of gas percentage present 78 21 1 [2]  (b)  oxides of nitrogen are atmospheric pollutants which can cause acid rain.   describe the formation of oxides of nitrogen and suggest how they can cause acid rain.            ..   [3]  (c)  methane contributes to the greenhouse effect.   state two sources of methane.  1  .  2  . [2]  (d)  combustion and respiration add carbon dioxide to the atmosphere.   name one natural process which removes carbon dioxide from the atmosphere.   ..   [1] [total: 8]",
            "6": "6 0620/42/o/n/16 \u00a9 ucles 20164  dilute nitric acid behaves as a typical acid in some reactions but not in other reactions.  (a)  dilute nitric acid behaves as a typical acid when reacted with copper( ii) oxide and with  copper( ii) carbonate.   describe what you would see if excess dilute nitric acid is added separately to solid samples  of copper( ii) carbonate and copper( ii) oxide followed by warming the mixtures.  copper( ii) carbonate        copper( ii) oxide       [4]  (b)  when dilute nitric acid is added to pieces of copper and heated, a reaction takes place and  copper( ii) nitrate is formed.  (i)  part of the chemical equation for the reaction between copper and dilute nitric acid is  shown.   complete the chemical equation by inserting the formula of copper( ii) nitrate and balancing  the equation. ..cu(s)  +  8hno3(aq)  \u2192  .(aq)  +  4h2o(l)  +  2no(g) [2]  (ii)  how is the reaction of dilute nitric acid with copper different from that of a typical metal with  a typical acid?   .   ...   [1] [total: 7]",
            "7": "7 0620/42/o/n/16 \u00a9 ucles 2016 [turn over5  chlorine, bromine and iodine are halogens.  (a)  chlorine can be made in the laboratory by heating manganese( iv) oxide with concentrated  hydrochloric acid. mno2(s)  +  4hcl (aq)  \u2192  mncl 2(aq)  +  2h2o(l)  +  c l 2(g)   calculate the volume of 8.00 mol / dm3 hcl (aq) needed to react with 3.48 g of mno2.  \u2022 moles of mno2 used  mol  \u2022 moles of hcl needed   mol  \u2022 volume of hc l needed   cm3 [4]  (b)  a student bubbled chlorine gas into a test-tube containing aqueous potassium bromide.  (i)  describe the colour change seen in the test-tube.  from ...  to  ... [2]  (ii)  complete the ionic  equation for this reaction.   include state symbols. cl 2(g)  +  ..br \u2013(aq)  \u2192    +   [3]",
            "8": "8 0620/42/o/n/16 \u00a9 ucles 2016 (c)  when one mole of bromine, br2, reacts with one mole of propene, one organic product is  formed.  (i)  which part of the propene molecule reacts with bromine?   ...   [1]  (ii)  what is the name of the type of reaction which takes place between bromine and propene?   ...   [1]  (d)  when one mole of chlorine, cl 2, reacts with one mole of propane, a mixture of two structural  isomers is formed.  (i)  what is the name of the type of reaction which takes place between chlorine and propane?   ...   [1]  (ii)  explain what is meant by the term structural isomers .   .   ...   [2]  (iii)  draw the structure of two structural isomers formed when one mole of chlorine reacts with  one mole of propane. [2]",
            "9": "9 0620/42/o/n/16 \u00a9 ucles 2016 [turn over (e)  iodine forms an oxide which has the composition by mass: i, 76.0%;  o, 24.0%.  (i)  use this information to determine the empirical formula of this oxide of iodine. empirical formula .  [3]  (ii)  the oxide of iodine in (e)(i) dissolves in water.   predict and explain the effect of adding universal indicator to an aqueous solution of this  oxide of iodine.  effect on universal indicator   ...  explanation  . [2] [total: 21]",
            "10": "10 0620/42/o/n/16 \u00a9 ucles 20166  aluminium is a very important metal.   aluminium is extracted from its ore, bauxite, by electrolysis. bauxite is an impure form of aluminium  oxide, al 2o3.  (a)  describe how aluminium is extracted from bauxite. include an ionic half-equation for the  reaction at each electrode.  description  .                       ionic half-equation for the anode reaction  .  ionic half-equation for the cathode reaction   [5]  (b)  explain why the anodes have to be replaced regularly.      ..   [2]  (c)  give two uses of aluminium and give a reason why aluminium is suitable for each use.  use 1  ..  reason    use 2  ..  reason   [4] [total: 11]",
            "11": "11 0620/42/o/n/16 \u00a9 ucles 2016 [turn overquestion 7 starts on the next page.",
            "12": "12 0620/42/o/n/16 \u00a9 ucles 20167  proteins are a major constituent of food.   proteins are polymers.  (a)  what is a polymer?         ..   [2]  (b)  proteins can be converted into amino acids.  (i)  name the type of chemical reaction which occurs when proteins are converted into amino  acids.   ...   [1]  (ii)  suggest a condition needed to convert proteins into amino acids.   ...   [1]  (c)  a colourless mixture of amino acids was separated by chromatography.   amino acid x has an rf value of 0.8.   the chromatogram of the mixture after treatment with a locating agent is shown. solvent front baseline  (i)  how is an rf value calculated?  rf = [1]  (ii)  on the diagram put a ring around the spot caused by amino acid x. [1]",
            "13": "13 0620/42/o/n/16 \u00a9 ucles 2016 [turn over (iii)  describe how you would perform a chromatography experiment to produce the  chromatogram shown in (c). assume you have been given the mixture of amino acids and  a suitable locating agent. you are provided with common laboratory apparatus.   .   .   .   .   .   ...   [3]",
            "14": "14 0620/42/o/n/16 \u00a9 ucles 2016 (d)  when one molecule of an amino acid a combines with one molecule of another amino acid b,  two different dipeptide molecules could be formed.   draw the structures of the two different dipeptide molecules.   show all of the atoms and all of the bonds in the linkages. amino acid a amino acid b n hh co o ho o hn hh c [3] [total: 12]",
            "15": "15 0620/42/o/n/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "16": "16 0620/42/o/n/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi v ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w16_qp_43.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/43   paper 4 theory (extended) october/november 2016  1 hour 15 minutes candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education this document consists of 12 printed pages. [turn overib16 11_0620_43/4rp\u00a9 ucles 2016 *0906632911* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/43/o/n/16 \u00a9 ucles 20161 (a)  complete the table. particle charge relative mass proton +1 neutron 1 electron [2]  (b)  the following are isotopes of carbon. c12 6          c13 6          c14 6  (i)  in terms of numbers of protons, neutrons and electrons, how are these three isotopes the  same and how are they different?   they are the same because  ...   .   they are different because  .   . [3]  (ii)  why do all isotopes of carbon have the same chemical properties?   ...   [1]  (c)  name two forms of the element carbon which have giant covalent structures.  .. and     [1]  (d)  complete the diagram to show the electron arrangement in a carbon dioxide molecule.   show the outer shell electrons only. o cc o [2] [total: 9]",
            "3": "3 0620/43/o/n/16 \u00a9 ucles 2016 [turn over2  beryllium is a metallic element in group ii.  (a)  give the electronic structure of a beryllium atom.   ..   [1]  (b)  give the formula of beryllium oxide.   ..   [1]  (c) (i)  describe the bonding in a metallic element such as beryllium.   include a labelled diagram and any appropriate charges in your answer.   .   .   ...   [3]  (ii)  explain why metallic elements, such as beryllium, are good conductors of electricity.   .   ...   [1]  (d)  beryllium hydroxide is amphoteric.   beryllium hydroxide reacts with acids. the salts formed contain positive beryllium ions.  (i)  give the formula of the positive beryllium ion.   ...   [1]  (ii)  write a chemical equation for the reaction between beryllium hydroxide and  hydrochloric acid.   ...   [2]  (iii)  beryllium hydroxide also reacts with alkalis. the salts formed contain beryllate ions,  beo22\u2013.   suggest a chemical equation for the reaction between beryllium hydroxide and  sodium hydroxide solution.   ...   [2] [total: 11]",
            "4": "4 0620/43/o/n/16 \u00a9 ucles 20163  when lead( ii) nitrate is heated, two gases are given off and solid lead( ii) oxide remains.    the equation for the reaction is shown. 2pb(no3)2(s)  \u2192  2pbo(s)  +  4no2(g)  +  o2(g)  (a)  calculate the mr of lead( ii) nitrate.   ..   [1]  (b)  6.62 g of lead( ii) nitrate are heated until there is no further change in mass.  (i)  calculate the mass of lead( ii) oxide produced. ... g  [2]  (ii)  calculate the volume of oxygen, o2, produced at room temperature and pressure (r.t.p.). ... dm3  [2]  (c)  describe a test for oxygen.   test  .   result  .. [2]",
            "5": "5 0620/43/o/n/16 \u00a9 ucles 2016 [turn over (d)  lead( ii) oxide is insoluble. a student adds solid lead( ii) oxide to dilute nitric acid until the  lead( ii) oxide is in excess. aqueous lead( ii) nitrate and water are produced.  (i)  what is meant by the term excess?   ...   [1]  (ii)  how would the student know when the lead( ii) oxide is in excess?   ...   [1]  (iii)  write a chemical equation for the reaction.   ...   [1] [total: 10]",
            "6": "6 0620/43/o/n/16 \u00a9 ucles 20164  silicon( iv) oxide and sodium chloride have different types of bonding and structure.  (a)  name the type of bonding present in   silicon( iv) oxide,  ...   sodium chloride.   [2]  (b)  name the type of structure present in silicon( iv) oxide.   ..   [1]  (c) (i)  silicon( iv) oxide has a high melting point. explain why.   .   ...   [2]  (ii)  silicon( iv) oxide is a poor conductor of electricity. explain why.   ...   [1]  (d)  solid sodium chloride does not conduct electricity. however, it conducts electricity when molten.   explain why solid sodium chloride does not conduct electricity, whereas molten sodium chloride  does conduct electricity.            ..   [3]  (e)  a concentrated aqueous solution of sodium chloride is electrolysed using carbon electrodes.   (i)  name the products formed at the electrodes.   product at the positive electrode (anode)  ...   product at the negative electrode (cathode)  ... [2]  (ii)  write an ionic half-equation for the reaction occurring at the negative electrode.   ...   [1]",
            "7": "7 0620/43/o/n/16 \u00a9 ucles 2016 [turn over (f)  a dilute  aqueous solution of sodium chloride is electrolysed using carbon electrodes.   name the main product formed at the positive electrode.   ..   [1]  (g)  molten sodium chloride is electrolysed using carbon electrodes.   (i)  name the product formed at the negative electrode.   ...   [1]  (ii) write an ionic half-equation for the reaction occurring at the negative electrode.   ...   [1]  (iii)  chlorine is produced at the positive electrode.   give the test for chlorine.  test  ..  result  ... [2] [total: 17]",
            "8": "8 0620/43/o/n/16 \u00a9 ucles 20165  sulfuric acid can be manufactured from the raw materials sulfur, air and water. the process can be  divided into four stages.   stage 1 converting sulfur into sulfur dioxide   stage 2 converting sulfur dioxide into sulfur trioxide   stage 3 converting sulfur trioxide into oleum, h2s2o7   stage 4 converting oleum into sulfuric acid  stage 1  (a) (i)  describe how sulfur is converted into sulfur dioxide.   ...   [1]  (ii)  write a chemical equation for the conversion of sulfur into sulfur dioxide.   ...   [1]  stage 2  (b)  sulfur dioxide is converted into sulfur trioxide according to the following equation. 2so2  +  o2    2so3   the reaction is carried out at a temperature of 450 \u00b0c and a pressure of 1\u20132 atmospheres  using a catalyst. the energy change, \u2206 h, for the reaction is \u2013196 kj / mol.  (i)  what is the meaning of the symbol ?   ...   [1]  (ii)  name the catalyst used in this reaction.   ...   [1]  (iii)  why is a catalyst used?   ...   [1]  (iv)  if a temperature higher than 450 \u00b0c were used, what would happen to the amount of  sulfur trioxide produced? give a reason for your answer.   .   ...   [2]  (v)  suggest a reason why a temperature lower than 450 \u00b0c is not used.   .   ...   [1]",
            "9": "9 0620/43/o/n/16 \u00a9 ucles 2016 [turn over (vi)  if a pressure higher than 1\u20132 atmospheres were used, what would happen to the amount  of sulfur trioxide produced? give a reason for your answer.   .   ...   [2]  stage 3  (c) (i)  what is added to sulfur trioxide to convert it into oleum?   ...   [1]  (ii)  write a chemical equation for the conversion of sulfur trioxide into oleum.   ...   [1]  stage 4  (d) (i)  what is added to oleum to convert it into sulfuric acid?   ...   [1]  (ii)  write a chemical equation for the conversion of oleum into sulfuric acid.   ...   [1]  (e)  give one use of sulfuric acid.   ..   [1]  (f)  sulfuric acid reacts with a hydrocarbon called benzene to produce benzenesulfonic acid,  c6h5so3h. benzenesulfonic acid is a strong acid which ionises to produce hydrogen ions, h+,  and benzenesulfonate ions, c6h5so3\u2013.  (i)  what is meant by the term strong acid ?   ...   [1]  (ii)  describe how to show that a 1 mol / dm3 solution of benzenesulfonic acid is a strong acid.   .   ...   [2]  (iii)  write a chemical equation for the reaction between benzenesulfonic acid and  sodium carbonate, na2co3.   ...   [2] [total: 20]",
            "10": "10 0620/43/o/n/16 \u00a9 ucles 20166  synthetic polyamides are made by condensation polymerisation.  (a) (i)  what is meant by the term condensation polymerisation ?   .   .   ...   [3]  (ii) name another type of polymerisation.   ...   [1]  (b)  one repeat unit of a synthetic polyamide is represented by the following structure. co co n hn h  (i)  draw a ring around the amide link. [1]  (ii)  complete the diagrams to show the structures of the monomers used to produce the  synthetic polyamide. show all the missing atoms and bonds. c c n n [2]  (iii)  name an example of a synthetic polyamide.   ...   [1]  (c)  proteins and synthetic polyamides have similarities and differences.  (i)  name the type of compounds that are the monomers used to make up proteins.   ...   [1]",
            "11": "11 0620/43/o/n/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (ii)  starting with a sample of protein, describe how to produce, separate, detect and identify  the monomers which make it up.   your answer should include  \u2022  the name of the process used to break down the protein into its monomers,  \u2022  the name of the process used to separate the monomers,  \u2022  the method used to detect the monomers after they have been separated,  \u2022  the method used to identify the monomers after they have been separated.   .   .   .   .   ...   [4] [total: 13]",
            "12": "12 0620/43/o/n/16 \u00a9 ucles 2016 groupthe periodic table of elements 1 h hydrogen 12 he helium 4i ii iii iv v vi v ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w16_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/51   paper 5 practical test october/november 2016  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructions cambridge international examinations cambridge international general certificate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib16 11_0620_51/3rp\u00a9 ucles 2016 *4268017354* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/51/o/n/16 \u00a9 ucles 20161  you are going to investigate what happens when nitric acid reacts with aqueous solutions of two  different alkalis, solution n and solution o.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a) experiment 1   use a measuring cylinder to pour 50 cm3 of solution n into the polystyrene cup provided. put  the polystyrene cup into a 250 cm3 beaker for support. measure the initial temperature of the  solution and record it in the first row of the table.   fill the burette with nitric acid to the 0.0 cm3 mark.   add 5.0 cm3 of nitric acid to solution n in the polystyrene cup and stir the solution.   measure and record the maximum temperature of the solution in the table.   add a further 5.0 cm3 of nitric acid to the polystyrene cup and stir the solution. measure and  record the maximum temperature of the solution in the table.   continue to add 5.0 cm3 portions of nitric acid to the polystyrene cup, until a total volume of  40 cm3 of nitric acid has been added. stir after each addition and measure and record the  maximum temperatures in the table.   pour the solution away and rinse the polystyrene cup. volume of nitric acid added / cm3maximum temperature of the solution in the polystyrene cup / \u00b0c 0.0 5.0 10.015.020.025.030.035.040.0 [2]",
            "3": "3 0620/51/o/n/16 \u00a9 ucles 2016 [turn over (b) experiment 2   refill the burette with nitric acid.   repeat experiment 1 using solution o instead of solution n.   record your results in the table. volume of nitric acid added / cm3maximum temperature of the solution in the polystyrene cup / \u00b0c 0.0 5.0 10.015.020.025.030.035.040.0 [2]",
            "4": "4 0620/51/o/n/16 \u00a9 ucles 2016 (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label your graphs. 0 10 20 volume of nitric acid added  / cm3maximum temperature of solution / \u00b0c 30 4040 30 20 10 [4]  (d)  use your graph to estimate the maximum temperature of the solution when 13 cm3 of nitric acid  were added to 50 cm3 of solution n in experiment 1.   show clearly on the grid  how you worked out your answer. .. \u00b0c  [2]",
            "5": "5 0620/51/o/n/16 \u00a9 ucles 2016 [turn over (e)  name a suitable indicator that could be used in experiment 1.   ..   [1]  (f)  solution n and solution o are the same concentration.   in which experiment is the temperature change greater? suggest why the temperature change  is greater in this experiment.      ..   [2]  (g)  how would the results differ in experiment 1 if 100 cm3 of solution n were used?      ..   [1]  (h)  suggest why a polystyrene cup is used in these experiments and not a copper can.   ..   [1]  (i)  state one source of error in the experiments. suggest an improvement to reduce this source  of error.   source of error  ...   improvement  .. [2] [total: 17]",
            "6": "6 0620/51/o/n/16 \u00a9 ucles 20162  you are provided with solid p, which is a metallic salt.   carry out the following tests on solid p, recording all of your observations at each stage.  tests on solid p  (a)  describe the appearance of solid p.   ..   [1]  (b)  use a spatula to divide solid p into three portions.  (i)  test 1   heat the first portion of solid p in a hard-glass test-tube.   test any gases given off with cobalt( ii) chloride paper.   record your observations.   .   .   ...   [3]  (ii) test 2   carry out a flame test on the second portion of solid p.   record your observations.   ...   [1]  tests on a solution of p   add about 10 cm3 of distilled water to the third portion of solid p in a test-tube. stopper the test-tube  and shake it to dissolve solid p.  (c)  divide the solution into four equal portions in four test-tubes. carry out the following tests.  (i)  to the first portion of the solution, add several drops of aqueous sodium hydroxide.   then add excess aqueous sodium hydroxide to the mixture.   record your observations.   .   .   ...   [3]  (ii) to the second portion of the solution, add excess aqueous ammonia.   record your observations.       ...   [1]",
            "7": "7 0620/51/o/n/16 \u00a9 ucles 2016 [turn over (iii)  to the third portion of the solution, add a few drops of dilute nitric acid and about 1 cm3 of  aqueous silver nitrate.   record your observations.   ...   [1]  (iv)  to the fourth portion of the solution, add a few drops of dilute nitric acid and about 1 cm3 of  aqueous barium nitrate.   record your observations.   .   ...   [2]  (d)  solid p contains a metal ion.   suggest what the appearance of solid p in (a) tells you about the identity of the metal ion.   ..   [1]  (e)  what does test 1 tell you about solid p?   ..   [1]  (f)  what does test 2 tell you about solid p?   ..   [1]  (g)  identify solid p.      ..   [2] [total: 17]",
            "8": "8 0620/51/o/n/16 \u00a9 ucles 20163  agri limes are mixtures of calcium carbonate and calcium oxide. farmers use agri limes on fields  to neutralise acidity.   plan an investigation to find out which of two different agri limes, q or r, will neutralise more acid.  you are provided with common laboratory apparatus and chemicals, including dilute nitric acid.   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "9": "9 0620/51/o/n/16 \u00a9 ucles 2016blank page",
            "10": "10 0620/51/o/n/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/51/o/n/16 \u00a9 ucles 2016notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt. or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/51/o/n/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. test for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_w16_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/52   paper 5 practical test october/november 2016  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructions cambridge international examinations cambridge international general certificate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib16 11_0620_52/fp\u00a9 ucles 2016 *6860639257* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/52/o/n/16 \u00a9 ucles 20161  you are going to investigate what happens when nitric acid reacts with aqueous solutions of two  different alkalis, solution n and solution o.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a) experiment 1   use a measuring cylinder to pour 50 cm3 of solution n into the polystyrene cup provided. put  the polystyrene cup into a 250 cm3 beaker for support. measure the initial temperature of the  solution and record it in the first row of the table.   fill the burette with nitric acid to the 0.0 cm3 mark.   add 5.0 cm3 of nitric acid to solution n in the polystyrene cup and stir the solution.   measure and record the maximum temperature of the solution in the table.   add a further 5.0 cm3 of nitric acid to the polystyrene cup and stir the solution. measure and  record the maximum temperature of the solution in the table.   continue to add 5.0 cm3 portions of nitric acid to the polystyrene cup, until a total volume of  40 cm3 of nitric acid has been added. stir after each addition and measure and record the  maximum temperatures in the table.   pour the solution away and rinse the polystyrene cup. volume of nitric acid added / cm3maximum temperature of the solution in the polystyrene cup / \u00b0c 0.0 5.0 10.015.020.025.030.035.040.0 [2]",
            "3": "3 0620/52/o/n/16 \u00a9 ucles 2016 [turn over (b) experiment 2   refill the burette with nitric acid.   repeat experiment 1 using solution o instead of solution n.   record your results in the table. volume of nitric acid added / cm3maximum temperature of the solution in the polystyrene cup / \u00b0c 0.0 5.0 10.015.020.025.030.035.040.0 [2]",
            "4": "4 0620/52/o/n/16 \u00a9 ucles 2016 (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label your graphs. 0 10 20 volume of nitric acid added  / cm3maximum temperature of solution / \u00b0c 30 4040 30 20 10 [4]  (d)  use your graph to estimate the maximum temperature of the solution when 13 cm3 of nitric acid  were added to 50 cm3 of solution n in experiment 1.   show clearly on the grid  how you worked out your answer. .. \u00b0c  [2]",
            "5": "5 0620/52/o/n/16 \u00a9 ucles 2016 [turn over (e)  name a suitable indicator that could be used in experiment 1.   ..   [1]  (f)  solution n and solution o are the same concentration.   in which experiment is the temperature change greater? suggest why the temperature change  is greater in this experiment.      ..   [2]  (g)  how would the results differ in experiment 1 if 100 cm3 of solution n were used?      ..   [1]  (h)  suggest why a polystyrene cup is used in these experiments and not a copper can.   ..   [1]  (i)  state one source of error in the experiments. suggest an improvement to reduce this source  of error.   source of error  ...   improvement  .. [2] [total: 17]",
            "6": "6 0620/52/o/n/16 \u00a9 ucles 20162  you are provided with solid p, which is a metallic salt.   carry out the following tests on solid p, recording all of your observations at each stage.  tests on solid p  (a)  describe the appearance of solid p.   ..   [1]  (b)  use a spatula to divide solid p into three portions.  (i)  test 1   heat the first portion of solid p in a hard-glass test-tube.   test any gases given off with cobalt( ii) chloride paper.   record your observations.   .   .   ...   [3]  (ii) test 2   carry out a flame test on the second portion of solid p.   record your observations.   ...   [1]  tests on a solution of p   add about 10 cm3 of distilled water to the third portion of solid p in a test-tube. stopper the test-tube  and shake it to dissolve solid p.  (c)  divide the solution into four equal portions in four test-tubes. carry out the following tests.  (i)  to the first portion of the solution, add several drops of aqueous sodium hydroxide.   then add excess aqueous sodium hydroxide to the mixture.   record your observations.   .   .   ...   [3]  (ii) to the second portion of the solution, add excess aqueous ammonia.   record your observations.       ...   [1]",
            "7": "7 0620/52/o/n/16 \u00a9 ucles 2016 [turn over (iii)  to the third portion of the solution, add a few drops of dilute nitric acid and about 1 cm3 of  aqueous silver nitrate.   record your observations.   ...   [1]  (iv)  to the fourth portion of the solution, add a few drops of dilute nitric acid and about 1 cm3 of  aqueous barium nitrate.   record your observations.   .   ...   [2]  (d)  solid p contains a metal ion.   suggest what the appearance of solid p in (a) tells you about the identity of the metal ion.   ..   [1]  (e)  what does test 1 tell you about solid p?   ..   [1]  (f)  what does test 2 tell you about solid p?   ..   [1]  (g)  identify solid p.      ..   [2] [total: 17]",
            "8": "8 0620/52/o/n/16 \u00a9 ucles 20163  agri limes are mixtures of calcium carbonate and calcium oxide. farmers use agri limes on fields  to neutralise acidity.   plan an investigation to find out which of two different agri limes, q or r, will neutralise more acid.  you are provided with common laboratory apparatus and chemicals, including dilute nitric acid.   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "9": "9 0620/52/o/n/16 \u00a9 ucles 2016blank page",
            "10": "10 0620/52/o/n/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/52/o/n/16 \u00a9 ucles 2016notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt. or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/52/o/n/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. test for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_w16_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.practical notes are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/53   paper 5 practical test october/november 2016  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructions cambridge international examinations cambridge international general certificate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib16 11_0620_53/2rp\u00a9 ucles 2016 *6748383641* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/53/o/n/16 \u00a9 ucles 20161  you are going to investigate what happens when two different metals, iron and magnesium, react  with aqueous copper( ii) sulfate.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a) experiment 1   use a measuring cylinder to pour 25 cm3 of aqueous copper( ii) sulfate into the polystyrene  cup provided. put the polystyrene cup into a 250 cm3 beaker for support. measure the initial  temperature of the solution and then the temperature after 30 seconds and 60 seconds. record  your results in the table.   at 60 seconds add all of the iron to the aqueous copper( ii) sulfate and stir the mixture  continuously with the thermometer.   measure the temperature of the mixture every 30 seconds for 300 seconds (5 minutes). record  your results in the table. time / s 0 30 60 90 120 150 180 210 240 270 300 temperature / \u00b0c [2]  (b) experiment 2   empty the polystyrene cup and rinse it with water.   use a measuring cylinder to pour 25 cm3 of aqueous copper( ii) sulfate into the polystyrene  cup. put the polystyrene cup into a 250 cm3 beaker for support. measure the initial temperature  of the solution and then the temperature after 30 seconds and 60 seconds. record your results in the table.   at 60 seconds add all of the magnesium to the aqueous copper( ii) sulfate and stir the mixture   continuously with the thermometer.   measure the temperature of the mixture every 30 seconds for 300 seconds (5 minutes). record  your results in the table. time / s 0 30 60 90 120 150 180 210 240 270 300 temperature / \u00b0c [2]",
            "3": "3 0620/53/o/n/16 \u00a9 ucles 2016 [turn over (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label the graphs. 90 80 70 60 50 4030 20 10 0 60 120 180 time  / stemperature / \u00b0c 240 300 360 [4]  (d) (i)  from your graph, deduce the temperature of the mixture in experiment 1 after  135 seconds.   show clearly on the grid  how you worked out your answer. ... \u00b0c  [2]  (ii)  from your graph, deduce the time taken for the temperature of the mixture in experiment 2  to change by 30 \u00b0c after the magnesium was added.   show clearly on the grid  how you worked out your answer. . s  [2]",
            "4": "4 0620/53/o/n/16 \u00a9 ucles 2016 (e)  predict the temperature of the mixture in experiment 2 after one hour. explain your answer.      ..   [2]  (f)  suggest an advantage of taking the temperature readings every 15 seconds.      ..   [2]  (g)  explain why a polystyrene cup is used in the experiments and not a copper can.      ..   [2] [total: 18]",
            "5": "5 0620/53/o/n/16 \u00a9 ucles 2016 [turn over2  you are provided with two solutions, solution q and solution r.   carry out the following tests on solution q and solution r, recording all of your observations at each  stage.  tests on solution q  (a)  divide solution q into four equal portions in four test-tubes. carry out the following tests.  (i)  use ph indicator paper to measure the ph of the first portion of solution q.  ph  .   [1]  (ii)  add a 2 cm strip of magnesium ribbon to the second portion of solution q. test the gas  given off.   record your observations.   .   ...   [2]  (iii)  add a spatula measure of sodium carbonate to the third portion of solution q. test the gas  given off.   record your observations.   .   ...   [2]  (iv)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous barium nitrate to the fourth  portion of solution q.   record your observations.   ...   [1]  tests on solution r  (b) divide solution r into four equal portions in four test-tubes. carry out the following tests.  (i)  measure the ph of the first portion of solution r.  ph  .   [1]  (ii)  add several drops of aqueous sodium hydroxide to the second portion of solution r and  shake the test-tube.   then add excess aqueous sodium hydroxide to the test-tube.   record your observations.   .   ...   [2]",
            "6": "6 0620/53/o/n/16 \u00a9 ucles 2016 (iii)  add aqueous silver nitrate to the third portion of solution r and leave to stand for about  5 minutes.   record your observations.   .   ...   [2]  (iv)  add a spatula measure of iron( ii) sulfate crystals to the fourth portion of solution r and  shake the mixture.   record your observations.   ...   [1]  (c)  identify solution q.   ..   [2]  (d)  identify solution r.   ..   [2] [total: 16]",
            "7": "7 0620/53/o/n/16 \u00a9 ucles 2016 [turn over3  a liquid cleaner is a mixture of three substances. these substances are shown in the table. name of substance properties of substance water liquid, boiling point 100 \u00b0c sodium carbonate solid, soluble in water silica solid, insoluble in water   plan experiments to obtain separate pure samples of each substance from the mixture in the liquid  cleaner. you are provided with common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "8": "8 0620/53/o/n/16 \u00a9 ucles 2016blank page",
            "9": "9 0620/53/o/n/16 \u00a9 ucles 2016blank page",
            "10": "10 0620/53/o/n/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/53/o/n/16 \u00a9 ucles 2016notes for use in qualitative analysis test for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt. or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/53/o/n/16 \u00a9 ucles 2016permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. test for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_w16_qp_61.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib16 11_0620_61/3rp \u00a9 ucles 2016 *0345891151* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/61   paper 6 alternative to practical october/november 2016  1 hour candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/61/o/n/16 \u00a9 ucles 20161  the diagram shows the apparatus used to electrolyse dilute sulfuric acid. dilute sulfuric acidhydrogen oxygen + \u2013platinum   (a)  complete the box to show the role of the platinum. [1]  (b)  give one observation made during this electrolysis.   ..   [1]  (c) (i)  compare the volumes of oxygen and hydrogen produced.   .   ...   [2]  (ii)  which substance breaks down to form these gases?   ...   [1]  (d)  give one test to distinguish between oxygen and hydrogen.  test  .  result with oxygen  ..  result with hydrogen  .. [2] [total: 7]",
            "3": "3 0620/61/o/n/16 \u00a9 ucles 2016 [turn over2  a student investigated what happened when dilute nitric acid reacted with aqueous solutions of two  different alkalis, solution n and solution o.   two experiments were carried out.  (a) experiment 1   a measuring cylinder was used to pour 50 cm3 of solution n into a polystyrene cup. the initial  temperature of the solution was measured.   a burette was filled with nitric acid to the 0.0 cm3 mark.   5.0 cm3 of nitric acid were added to solution n in the polystyrene cup and the solution stirred.   the maximum temperature of the solution was measured.   a further 5.0 cm3 of nitric acid were added to the polystyrene cup and the solution stirred. the  maximum temperature of the solution was measured.   the student continued to add 5.0 cm3 portions of nitric acid to the polystyrene cup, until a total  volume of 40 cm3 of nitric acid had been added. after each addition, the solution was stirred  and the maximum temperature measured.",
            "4": "4 0620/61/o/n/16 \u00a9 ucles 2016  use the thermometer diagrams to record the maximum temperatures in the table. 30 25 2030 25 2035 30 2535 30 2535 30 2540 35 3035 30 2535 30 2535 30 25thermometer diagramvolume of nitric acid added  / cm3 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 maximum temperature of the solution in the polystyrene cup  / \u00b0c [2]  (b) experiment 2   experiment 1 was repeated using solution o instead of solution n.   use the thermometer diagrams to record the maximum temperatures in the table. 30 25 2030 25 2030 25 2030 25 2030 25 2030 25 2030 25 2030 25 2030 25 20thermometer diagramvolume of nitric acid added  / cm3 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 maximum temperature of the solution in the polystyrene cup  / \u00b0c [2]",
            "5": "5 0620/61/o/n/16 \u00a9 ucles 2016 [turn over (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label your graphs. maximum temperature of solution / \u00b0c35 30 25 20 15 0 10 20 volume of nitric acid added  / cm330 40 [4]  (d)  use your graph to estimate the maximum temperature of the solution when 13 cm3 of nitric acid  were added to 50 cm3 of solution n in experiment 1.   show clearly on the grid  how you worked out your answer. .. \u00b0c  [2]  (e)  name a suitable indicator that could be used in experiment 1.   ..   [1]",
            "6": "6 0620/61/o/n/16 \u00a9 ucles 2016 (f)  solution n and solution o were the same concentration.   in which experiment is the temperature change greater? suggest why the temperature change  is greater in this experiment.      ..   [2]  (g)  how would the results differ in experiment 1 if 100 cm3 of solution n were used?      ..   [1]  (h)  suggest why a polystyrene cup was used in these experiments and not a copper can.   ..   [1]  (i)  state one source of error in the experiments. suggest an improvement to reduce this source  of error.  source of error  ...  improvement  .. [2] [total: 17]",
            "7": "7 0620/61/o/n/16 \u00a9 ucles 2016 [turn over3  solid p, which is an aluminium salt, was analysed.   the tests on solid p, and some of the observations, are shown.  tests on solid p  (a)  test 1  solid p was divided into three portions. the first portion of solid p was heated.  observations   ...   any gases given off were tested with cobalt( ii) chloride paper.  observations   ...   what does test 1 tell you about solid p?   ..   [1]  (b) test 2   a flame test was carried out on the second portion of solid p.  observations     [1]  tests on a solution of p   distilled water was added to the rest of solid p in a test-tube and shaken to dissolve.  (c)  the solution was divided into four equal portions in four test-tubes. the following tests were  carried out.  (i) test 3   several drops of aqueous sodium hydroxide were added to the first portion of the solution.   excess aqueous sodium hydroxide was then added to the mixture.  observations  ...   .   ...   [3]cobalt( ii) chloride paper turned from blue to pinkcondensation formed on the sides of the test-tube",
            "8": "8 0620/61/o/n/16 \u00a9 ucles 2016 (ii) test 4   several drops of aqueous ammonia were added to the second portion of the solution.    excess aqueous ammonia was then added to the mixture.  observations  ...   ...   [2]  two further tests were carried out and the following observations made. tests on a solution of p observations test 5 dilute nitric acid and aqueous silver nitrate were  added to the third portion of the solution.no visible reaction test 6 dilute nitric acid and aqueous barium nitrate  were added to the fourth portion of the solution.white precipitate formed  (d)  what does test 5 tell you about solid p?   ..   [1]  (e)  identify solid p.   ..   [1]  (f)  describe the appearance of solid p.   ..   [1] [total: 10]",
            "9": "9 0620/61/o/n/16 \u00a9 ucles 2016 [turn over4  agri limes are mixtures of calcium carbonate and calcium oxide. farmers use agri limes on fields  to neutralise acidity.   plan an investigation to find out which of two different agri limes, q or r, will neutralise more acid.  you are provided with common laboratory apparatus and chemicals, including dilute nitric acid.   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "10": "10 0620/61/o/n/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/61/o/n/16 \u00a9 ucles 2016blank page",
            "12": "12 0620/61/o/n/16 \u00a9 ucles 2016blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. "
        },
        "0620_w16_qp_62.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib16 11_0620_62/2rp \u00a9 ucles 2016 *0804599590* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/62   paper 6 alternative to practical october/november 2016  1 hour candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/o/n/16 \u00a9 ucles 20161  this question is about the separation of mixtures.   the diagram shows four sets of apparatus that can be used to separate mixtures. heatheatd c b a  (a)  complete the boxes to name the apparatus. [2]  (b)  the table shows four different mixtures.   complete the table to show which set of apparatus should be used to obtain the substance  listed. the first one has been completed for you. each set of apparatus can be used once, more than once or not at all. mixture to obtain use apparatus petroleum and water petroleum b sodium chloride dissolved in watersodium chloride crystals sodium chloride dissolved in waterwater insoluble silver chloride and watersilver chloride [3]  (c)  put a ring around the separation method that should be used to separate a mixture of coloured dyes. centrifugation          chromatography          condensation          evaporation [1] [total: 6]",
            "3": "3 0620/62/o/n/16 \u00a9 ucles 2016 [turn over2  a student investigated the rate of reaction between dilute hydrochloric acid and excess magnesium  at room temperature.   the apparatus was set up as shown in the diagram. watermagnesium ribbonmeasurin g cylinderdilute hydrochloric acid   30 cm3 of dilute hydrochloric acid were added to the conical flask containing magnesium ribbon. the  timer was then started and the volume of gas collected in the measuring cylinder was measured every 20 seconds for 180 seconds (3 minutes).",
            "4": "4 0620/62/o/n/16 \u00a9 ucles 2016 (a)  use the measuring cylinder diagrams to record the total volume of gas collected in the table. 0 30time  / smeasuring cylinder diagramtotal volume of gas collected  / cm3 2050 45 40 40 35 30 4060 55 50 606560 55 80807570 1009085 80 12095 90 85 14095 9085 1609590 85 18095 90 85 [2]",
            "5": "5 0620/62/o/n/16 \u00a9 ucles 2016 [turn over (b)  plot the results on the grid and draw a smooth line graph. 100 90 80 70 60 50 40 30 0 40 80 time  / stotal volume of gas collected / cm3 120 160 200 [3]  (c) (i)  which result is anomalous?   ...   [1]  (ii)  suggest a possible reason for this anomalous result.   ...   [1]  (iii)  use your graph to deduce the total volume of gas that you would have expected to   collect instead of this anomalous volume.   show clearly on the grid  how you worked out your answer. . cm3  [2]",
            "6": "6 0620/62/o/n/16 \u00a9 ucles 2016 (d)  explain why the total volume of gas collected does not increase after 160 seconds.      ..   [2]  (e)  the average rate of the reaction can be calculated using the equation shown. average rate of reaction =volume of gas collected / cm3 time / s  (i)  calculate the volume of gas collected between 20 seconds and 40 seconds.   ...   [1]  (ii)  calculate the average rate of reaction between 20 seconds and 40 seconds.   include the unit. average rate of reaction = ...  [2]  (f)  room temperature was 20 \u00b0c.   sketch on the grid  the graph you would expect if the experiment were repeated at 30 \u00b0c. [2]  (g)  suggest why the reading on the measuring cylinder was 30 cm3 after the acid had been added  and before the timer had been started.      ..   [1]  (h)  suggest and explain one improvement to this experiment.         ..   [2] [total: 19]",
            "7": "7 0620/62/o/n/16 \u00a9 ucles 2016 [turn over3  two solutions, solution s and solution t, were analysed. solution s was dilute hydrochloric acid.   the tests on solution s and solution t, and some of the observations, are shown.  tests on solution s  (a)  solution s was divided into four equal portions in four test-tubes. the following tests were  carried out.   complete the observations for tests 1\u20134 .  (i) test 1   the ph of the first portion of solution s was tested.  ph  .   [1]  (ii) test 2   copper( ii) oxide was added to the second portion of the solution. the mixture was heated.  observations  ...   .   ...   [2]  (iii) test 3   solid sodium carbonate was added to the third portion of the solution. the gas given off  was tested.  observations  ...   ...   [3]  (iv) test 4   dilute nitric acid and aqueous silver nitrate were added to the fourth portion of the solution.  observations  .   [1]",
            "8": "8 0620/62/o/n/16 \u00a9 ucles 2016  tests on solution t  (b)  tests were carried out on solution t and the following observations made. tests observations solution t was divided into three equal  portions in three test-tubes. appearance of the solution. yellow solution drops of aqueous sodium hydroxide were  added to the second portion of the solution  and the test-tube shaken. excess aqueous sodium hydroxide was then  added to the test-tube.red-brown precipitate no visible change aqueous sodium hydroxide and aluminium foil were added to the third portion of the solution and the mixture heated.the gas given off was tested with ph indicator paper. pungent gas formed, ph 10   identify solution t.      ..   [2] [total: 9]",
            "9": "9 0620/62/o/n/16 \u00a9 ucles 2016 [turn over4  metal rings can be coated with a layer of copper using electricity.   plan an experiment to electroplate a small metal ring with copper.   you are provided with common laboratory apparatus, a copper rod, copper( ii) sulfate crystals,  water and a small metal ring.   include a labelled diagram in your answer.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "10": "10 0620/62/o/n/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/62/o/n/16 \u00a9 ucles 2016blank page",
            "12": "12 0620/62/o/n/16 \u00a9 ucles 2016blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. "
        },
        "0620_w16_qp_63.pdf": {
            "1": "this document consists of 8 printed pages and 4 blank pages. [turn overib16 11_0620_63/3rp \u00a9 ucles 2016 *3013059835* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/63   paper 6 alternative to practical october/november 2016  1 hour candidates answer on the question paper. no additional materials are required. cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/63/o/n/16 \u00a9 ucles 20161  the diagram shows the apparatus used to crack paraffin oil. paraffin oil vapour is passed over  heated aluminium oxide to produce a mixture of hydrocarbons containing alkenes. very strong heatliquid paraf fin oil on mineral woolaluminium oxide mixture of hydrocarbonscontaining alkenes water  (a)  complete the boxes to name the apparatus. [2]  (b)  what is the purpose of the mineral wool?      ..   [1]  (c)  give a test to show the presence of alkenes.  test  .  result  .. [2]  (d)  why must the delivery tube be removed from the water when the heating is stopped?   ..   [1] [total: 6]",
            "3": "3 0620/63/o/n/16 \u00a9 ucles 2016blank page [turn over",
            "4": "4 0620/63/o/n/16 \u00a9 ucles 20162  a student investigated what happened when two different metals, iron and magnesium, reacted  with aqueous copper( ii) sulfate.   two experiments were carried out.  (a) experiment 1   a measuring cylinder was used to pour 25 cm3 of aqueous copper( ii) sulfate into a polystyrene  cup. the initial temperature of the solution was measured, then again at 30 seconds and at  60 seconds.   at 60 seconds, the iron was added to the aqueous copper( ii) sulfate and the mixture stirred  continuously with a thermometer.   the temperature of the mixture was measured every 30 seconds for 300 seconds (5 minutes).   use the thermometer diagrams to record the results in the table. thermometer diagramtime  / s 0 30 60 90 120 150 180 210 240 270 300 temperature / \u00b0c25 20 1525 20 1525 20 1530 25 2030 25 2040 35 3040 35 3040 35 3040 35 3040 35 3040 35 30 [2]  (b)  experiment 2   experiment 1 was repeated using magnesium instead of iron.   use the thermometer diagrams to record the results in the table. thermometer diagramtime  / s 0 30 60 90 120 150 180 210 240 270 300 temperature / \u00b0c25 20 1525 20 1525 20 1575 70 6580 75 7080 75 7080 75 7075 70 6575 70 6570 65 6070 65 60 [2]",
            "5": "5 0620/63/o/n/16 \u00a9 ucles 2016 [turn over (c)  plot the results for experiments 1 and 2 on the grid and draw two smooth line graphs.   clearly label the graphs. 80 70 60 50 40 3020 10 0 60 120 180 time  / stemperature / \u00b0c 240 300 360 [4]  (d) (i)  from your graph, deduce the temperature of the mixture in experiment 1 after  135 seconds.   show clearly on the grid  how you worked out your answer. \u2026\u2026\u2026\u2026.\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 \u00b0c  [2]  (ii)  from your graph, deduce the time taken for the temperature of the mixture in experiment 2  to change by 30 \u00b0c after the magnesium was added.   show clearly on the grid  how you worked out your answer. ..\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026. s  [2]",
            "6": "6 0620/63/o/n/16 \u00a9 ucles 2016 (e)  predict the temperature of the mixture in experiment 2 after one hour. explain your answer.      ..   [2]  (f)  suggest an advantage of taking the temperature readings every 15 seconds.      ..   [2]  (g)  explain why a polystyrene cup is used in the experiments and not a copper can.      ..   [2] [total: 18]",
            "7": "7 0620/63/o/n/16 \u00a9 ucles 2016 [turn over3  two solutions, solution q and solution r, were analysed. solution q was aqueous sulfuric acid.  tests on solution q  (a)  solution q was divided into four equal portions in four test-tubes. the following tests were  carried out.   complete the observations for tests 1\u2013 4.  (i) test 1   the ph of the first portion of solution q was measured.  ph  .   [1]  (ii)  test 2   magnesium ribbon was added to the second portion of solution q. the gas given off was  tested.  observations  ...   ...   [3]  (iii) test 3   sodium carbonate was added to the third portion of solution q. the gas given off was  tested.  observations  ...   ...   [3]  (iv) test 4   dilute nitric acid and aqueous barium nitrate were added to the fourth portion of solution q.  observations  .   [1]",
            "8": "8 0620/63/o/n/16 \u00a9 ucles 2016 tests on solution r   solution r was divided into three equal portions in three test-tubes.   the following tests were carried out. tests observations test 5 the ph of the first portion of solution r was  measured. ph = 10 test 6 drops of aqueous sodium hydroxide were  added to the second portion of solution r and  the test-tube shaken. excess aqueous sodium hydroxide was then  added to the test-tube.white precipitate no visible change test 7  aqueous iron( ii) sulfate was added to the third  portion of solution r and the mixture shaken. green precipitate formed  (b)  identify solution r.      ..   [2] [total: 10]",
            "9": "9 0620/63/o/n/16 \u00a9 ucles 2016 [turn over4  a liquid cleaner is a mixture of three substances. these substances are shown in the table. name of substance properties of substance water liquid, boiling point 100 \u00b0c sodium carbonate solid, soluble in water silica solid, insoluble in water   plan an experiment to obtain separate pure samples of each substance from the mixture in the  liquid cleaner. you are provided with common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "10": "10 0620/63/o/n/16 \u00a9 ucles 2016blank page",
            "11": "11 0620/63/o/n/16 \u00a9 ucles 2016blank page",
            "12": "12 0620/63/o/n/16 \u00a9 ucles 2016blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. "
        }
    },
    "2017": {
        "0620_m17_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern irela nd as a cambridge international level1/level 2 certificate .  this document consists of 16 printed pages.  ib17 03_0620_12/3rp  \u00a9 ucles 2017 [turn over       *7306980568* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice (core)  february/march 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/12/f/m/17  1 a bottle of aqueous ammonia is placed on a table in a corner of the laboratory.    the stopper is removed and after a few minutes all the students in the room can smell the  ammonia.    which process occurs?  a brownian motion  b diffusion  c dissolving  d distillation      2 a student is investigating a coloured mixture using chromatography.    paper pencil line solvent    where should the student place the coloured mixture?  a in the solvent  b just above the pencil line  c just below the pencil line  d on the pencil line     ",
            "3": "3  \u00a9 ucles 2017 0620/12/f/m/17 [turn over  3 the diagrams show liquids in a burette and a measuring cylinder.    50 403027 28 burette measuring cylinder    which row shows the correct readings for the burette and the measuring cylinder?     burette measuring  cylinder  a 27.8 42  b 27.8 44  c 28.2 42  d 28.2 44      4 the diagram shows how muddy water can be purified.    muddy water clean waterfine sand gravel small pebbles     which process for purifying the muddy water is shown?  a crystallisation  b distillation  c filtration  d solvent extraction     ",
            "4": "4  \u00a9 ucles 2017 0620/12/f/m/17  5 the aluminium ion, a l 3+, has the same electronic structure as an atom of which noble gas?  a argon  b helium  c krypton  d neon     6 a covalent molecule m contains a total of four shared electrons.    what is m?  a ammonia, nh 3  b hydrogen chloride, hc l  c methane, ch 4  d water, h 2o      7 three substances have the properties shown.    \u25cf x conducts electricity when solid and when molten.  \u25cf y is soluble in water and the solution conducts electricity.  \u25cf z only conducts electricity when molten.    what are x, y and z?     x y z  a ca mgo naoh  b ca naoh mgo  c mgo ca naoh  d mgo naoh ca     ",
            "5": "5  \u00a9 ucles 2017 0620/12/f/m/17 [turn over  8 caffeine is a stimulant found in coffee.    n occ cchcn nnh3cch3 ch3o caffeine    which formula represents caffeine?  a c7h10n4o2 b c8h10n3o2 c c8h10n4o2 d c8h11n4o2     9 four substances are electrolysed.    the substances are concentrated aqueous sodium chloride, concentrated hydrochloric acid,  molten lead( ii) bromide and molten sodium oxide.    which statement about these electrolysis reactions is correct?  a a colourless gas is formed at the anode when molten sodium oxide is electrolysed.  b a green gas is formed at the cathode when concentrated hydrochloric acid is electrolysed.   c a metal is formed at the anode when molten lead( ii) bromide is electrolysed.  d a metal is formed at the cathode when concentrated aqueous sodium chloride is  electrolysed.      10 ammonium chloride is added to 100  cm3 of water. the temperature changes from 25  \u00b0c to 20  \u00b0c.    which type of reaction occurs?  a endothermic  b exothermic  c freezing   d neutralisation     ",
            "6": "6  \u00a9 ucles 2017 0620/12/f/m/17  11 a diagram for the energy change during an exothermic reaction is shown.    energyreactants products     for which reactions would this be an appropriate diagram?    1 ch 4  +  2o 2  \u2192  co 2  +  2h 2o  2 2h 2  +  o 2  \u2192  2h 2o  3 c  +  o 2  \u2192  co 2    a none of them  b 1 and 2 only  c 2 and 3 only  d all of them      12 the diagram shows the apparatus used to measure the rate of a chemical reaction.    52.73greactants balance     for which reaction can the rate be measured using this apparatus?  a 2na  +  c l 2  \u2192  2nac l  b naoh  +  hc l  \u2192  nac l  +  h 2o  c na2o  +  2hc l  \u2192  2nac l  +  h 2o  d na2co 3  +  2hc l  \u2192  2nac l  +  h 2o  +  co 2     ",
            "7": "7  \u00a9 ucles 2017 0620/12/f/m/17 [turn over  13 copper( ii) carbonate reacts with dilute sulfuric acid.    cuco 3(s)  +  h 2so 4(aq)  \u2192  cuso 4(aq)  +  co 2(g)  +  h 2o(l)    the rate of the reaction can be changed by varying the conditions.    which changes always increase the rate of this chemical reaction?    1 increasing the concentration of sulfuric acid  2 increasing the size of the pieces of copper( ii) carbonate  3 increasing the temperature  4 increasing the volume of sulfuric acid    a 1, 3 and 4 b 1 and 3 only c 2 and 3 d 3 and 4 only     14 in which reaction is the first substance in the equation oxidised?  a cao  +  h 2o  \u2192  ca(oh) 2  b 4feo  +  o 2  \u2192  2fe 2o3  c sno 2  +  2h 2  \u2192  sn  +  2h 2o  d znco 3  \u2192  zno  +  co 2      15 the equation for the effect of heat on hydrated sodium carbonate is as shown.    na2co 3.10h 2o(s)    na 2co 3(s)  +  10h 2o(g)    statements made by four students about the reaction are given.    p anhydrous sodium carbonate is formed.  q steam is formed.  r there is a colour change from blue to white.  s the reaction is reversible.    which students\u2019 statements are correct?  a p, q and r only  b p, q and s only  c q, r and s only  d p, q, r and s    ",
            "8": "8  \u00a9 ucles 2017 0620/12/f/m/17  16 which reaction is a neutralisation reaction?  a agno 3  +  hc l  \u2192  agc l  +  hno 3  b caco 3  \u2192  cao  +  co 2  c 4na  +  o 2  \u2192  2na 2o  d 2naoh  +  h 2so 4  \u2192  na 2so 4  +  2h 2o     17 elements w and x are metals.    elements y and z are non-metals.    the oxides of w, x, y and z all form solutions when added to water.    which statement is correct?  a the solution of the oxide of element w turns blue litmus red.  b the solution of the oxide of element x fizzes when sodium carbonate is added.  c the solution of the oxide of element y has a ph greater than ph 7.  d the solution of the oxide of element z fizzes when powdered magnesium is added.      18 a student is given an unknown solution.    which two tests provide evidence that the solution is copper( ii) sulfate?    1 adding dilute hydrochloric acid  2 adding aqueous sodium hydroxide 3 adding dilute nitric acid, then silver nitrate solution 4 adding dilute nitric acid, then barium nitrate solution    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "9": "9  \u00a9 ucles 2017 0620/12/f/m/17 [turn over  19 the diagram shows the steps in the preparation of a salt.    step 1 step 2 step 3 step 4    which salt is prepared by this method?  a barium sulfate  b copper( ii) sulfate  c potassium sulfate  d sodium sulfate     20 which property of elements increases across a period of the periodic table?  a metallic character  b number of electron shells  c number of outer shell electrons  d tendency to form positive ions     21 the noble gases are in group viii of the periodic table.    which statement explains why noble gases are unreactive?  a they all have eight electrons in their outer shells.  b they all have full outer shells.  c they are all gases.  d they are all monoatomic.     22 which compound is made from elements which are all in the same period?  a al  2(so 4)3 b c2h5oh  c lino 3 d na3al f6    ",
            "10": "10  \u00a9 ucles 2017 0620/12/f/m/17  23 part of the periodic table is shown.    which element is used as a catalyst?    a c db      24 which statement about all metals is correct?  a they are attracted to a magnet.  b they are weak and brittle.  c they may be used to form alloys.  d they react with water.     25 two experiments are carried out.    in experiment 1, copper is heated with steam.     in experiment 2, copper( ii) oxide is heated with carbon.    steam copper experiment 1 experiment 2heatcopper( ii) oxide and carbon     which row describes what happens in experiments 1 and 2?     experiment 1 experiment 2  a no reaction no reaction  b no reaction reaction  c reaction no reaction  d reaction reaction     ",
            "11": "11  \u00a9 ucles 2017 0620/12/f/m/17 [turn over  26 which metal is commonly used to form alloys with a non-metallic element?    a copper  b iron  c magnesium  d zinc      27 steel is made by adding ...  1 ... to molten iron to remove ...  2 ... from the iron.   stainless steel is ...  3 ... resistant to corrosion than mild steel.   which words complete the gaps 1, 2 and 3?   1 2 3  a basic oxides acidic impurities less  b basic oxides carbon more  c oxygen acidic impurities less  d oxygen carbon more     28 water is added to hydrated copper( ii) sulfate.    water hydrated copper( ii) sulfate    which colour change takes place?  a blue to pink  b blue to white  c no change  d white to blue     ",
            "12": "12  \u00a9 ucles 2017 0620/12/f/m/17  29 two reactions, x and y, produce carbon dioxide.     x y  ch 4    co 2    caco 3    which types of reaction are x and y?     x y  a combustion combustion  b combustion thermal decomposition  c thermal decomposition combustion  d thermal decomposition thermal decomposition    30 an experiment to find the percentage of oxygen in 150  cm3 of polluted air is shown.    waterdamp iron woolmeasuring cylinde r 150  cm3 of polluted air     the apparatus is left for one week.    after this time, the volume of gas in the measuring cylinder is 122  cm3.    what is the percentage of oxygen, to the nearest whole number, in the polluted air?  a 19% b 21% c 28% d 81%    31 ammonia is produced when a mixture of ammonium chloride and substance x is heated.    what is substance x?  a ammonium sulfate  b barium chloride  c calcium hydroxide  d silver nitrate     ",
            "13": "13  \u00a9 ucles 2017 0620/12/f/m/17 [turn over  32 which row is correct for both carbon dioxide and methane?     causes  climate change produced by  burning fuels produced by  living organisms  a \u0013 \u0013 \u0013  b \u0013 \u0013 \u0017  c \u0013 \u0017 \u0013  d \u0017 \u0013 \u0013     33 which statements about sulfur dioxide are correct?    1 it dissolves in water to produce a solution with a ph less than ph 7.  2 it is used as a food preservative.  3 it changes potassium manganate( vii) from colourless to purple.  4 it is produced by the combustion of sulfur-containing fossil fuels.    a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4     34 a student carried out two experiments.    experiment 1 the student heated a sample of limestone very strongly. a white powder formed.    experiment 2 the white powder from experiment 1 was cooled. the student then added a small  quantity of cold water to the powder. large quantities of steam were produced.    which statement is not correct?  a an endothermic reaction occurred in experiment 1.  b an exothermic reaction occurred in experiment 2.  c thermal decomposition occurred in experiment 1.  d thermal decomposition occurred in experiment 2.    35 which substance has a main constituent that contains only one carbon atom per molecule?  a bitumen  b gasoline  c natural gas  d petroleum    ",
            "14": "14  \u00a9 ucles 2017 0620/12/f/m/17  36 the table shows the composition of four different types of petroleum.    fraction arabian heavy  / % arabian light  / % iranian heavy  / % north sea  / %  gasoline 18 21 21 23  kerosene 11 15 13 15  diesel oil 18 21 20 24  fuel oil 53 43 46 38    which type of petroleum is best for the motor vehicle industry?  a arabian heavy  b arabian light  c iranian heavy  d north sea     37 ethanol is a fuel used in cars. it can be made from petroleum.     c 4h10  \u2192  c2h4  +  c 2h6 cracking   c 2h4  +  h 2o  \u2192  c2h5oh producing ethanol   c 2h5oh  +  3o 2  \u2192  2co 2  +  3h 2o burning    compounds of how many homologous series appear in these equations?  a 1 b 2 c 3 d 4      38 ethanol is produced from either ethene or sugar.    which type of chemical reaction is used in each case?     ethene \u2192 ethanol sugar \u2192 ethanol  a addition fermentation  b addition fractional distillation  c distillation fermentation  d distillation fractional distillation     ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/12/f/m/17  39 which type of hydrocarbon reacts rapidly with aqueous bromine and what is the colour change of  the aqueous bromine?     type of hydrocarbon colour change of the   aqueous bromine  a alkane brown to colourless  b alkane colourless to brown  c alkene brown to colourless  d alkene colourless to brown     40 the diagram shows the structure of an important product.    ch hchh chh chh chh chh c     this product is formed by \u2026...  1 .\u2026.. of an .\u2026..  2 \u2026\u2026 .    which words complete gaps 1 and 2?     1 2  a addition polymerisation alkane  b addition polymerisation alkene  c cracking alkane  d cracking alkene     ",
            "16": "16  \u00a9 ucles 2017 0620/12/f/m/17   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m17_qp_22.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificat e.  this document consists of 16 printed pages.  ib17 03_0620_22/5rp  \u00a9 ucles 2017 [turn over       *2721741017* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2 multiple choice (extended)  february/march 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first    write in soft pencil. do not use staples, paper clips, glue or correction fluid. write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.  each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet. a copy of the periodic table is printed on page 16. electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/22/f/m/17  1 a gas is released at point q in the apparatus shown.    damp universal indicator paperpoint q     which gas changes the colour of the damp universal indicator paper most quickly?     gas relative  molecular mass  a ammonia 17  b carbon dioxide 44  c chlorine 71  d hydrogen 2      2 the diagrams show liquids in a burette and a measuring cylinder.    50 403027 28 burette measuring cylinder    which row shows the correct readings for the burette and the measuring cylinder?     burette measuring  cylinder  a 27.8 42  b 27.8 44  c 28.2 42  d 28.2 44     ",
            "3": "3  \u00a9 ucles 2017 0620/22/f/m/17 [turn over  3 the diagram shows how muddy water can be purified.    muddy water clean waterfine sand gravel small pebbles     which process for purifying the muddy water is shown?  a crystallisation  b distillation  c filtration  d solvent extraction     4 which statement explains why isotopes of an element have the same chemical properties?  a they have different numbers of neutrons.  b they have the same number of electrons as protons.  c they have the same number of electrons in the outer shell.  d they have the same number of protons in the nucleus.    ",
            "4": "4  \u00a9 ucles 2017 0620/22/f/m/17  5 the formulae of some ions are shown.    positive ions negative ions  al 3+ br  \u2013  ca2+ co 32\u2013  cu2+ no 3\u2013  fe3+ s2\u2013  k+ so 42\u2013    in which row is the formula not correct?     compound formula  a aluminium sulfate a l 2(so 4)3  b calcium nitrate ca(no 3)2  c iron(iii) bromide fe 3br  d potassium sulfide k 2s      6 diamond and silicon( iv) oxide both have giant structures.    which statements are correct?    1 both substances are compounds.  2 there are strong covalent bonds in diamond.  3 silicon( iv) oxide is bonded ionically.  4 both substances have very high melting points.  a 1 and 2 b 2 and 3 c 2 and 4 d 3 and 4     7 which statement about metals is correct?  a layers of positive ions can slide over each other making metals malleable.  b metallic bonding consists of a lattice of negative ions in a sea of delocalised electrons.  c metallic bonding consists of a lattice of positive ions in a sea of delocalised negative ions.  d metals conduct electricity because positive ions are free to move.    ",
            "5": "5  \u00a9 ucles 2017 0620/22/f/m/17 [turn over  8 the gas hydrazine has the molecular formula n 2h4.    hydrazine burns in air to form nitrogen gas and steam.    n2h4(g)  +  o 2(g)  \u2192  n2(g)  +  2h 2o(g)    which statements are correct?    1 1 mole of hydrazine gives 72  dm3 of gaseous products when it reacts with oxygen at  room temperature and pressure.  2 the empirical formula of hydrazine is nh 2.  3 the total number of atoms in 1 mole of hydrazine is 6 \u00d7 the avogadro constant.  4 the volume of 1 mole of hydrazine at room temperature and pressure is 6 \u00d7 24  dm3.    a 1, 2 and 3 b 1 and 2 only c 2, 3 and 4 d 3 and 4 only      9 copper( ii) carbonate is broken down by heating to form copper( ii) oxide and carbon dioxide gas.    the equation for the reaction is shown.    cuco 3  \u2192  cuo  +  co 2    31.0  g of copper( ii) carbonate are heated until all of the contents of the test-tube have turned  from green to black.    the yield of copper( ii) oxide formed is 17.5  g.    what is the percentage yield?  a 19.02% b 21.88% c 56.50% d 87.50%      10 the diagram shows the electrolysis of aqueous copper( ii) sulfate.    + \u2013 aqueous copper( ii) sulfatecarbon electrodes     which statement is correct?  a copper metal is deposited at the positive electrode.  b in the external circuit the electrons move from positive to negative.  c in the solution the electrons move from negative to positive.  d oxygen gas is produced at the positive electrode. ",
            "6": "6  \u00a9 ucles 2017 0620/22/f/m/17  11 four solutions are separately electrolysed.    experiment solution electrodes  1 dilute aqueous sodium chloride carbon  2 aqueous copper( ii) sulfate copper  3 concentrated hydrochloric acid carbon  4 dilute sulfuric acid carbon    in which two experiments is a colourless gas evolved at the anode?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4      12 ammonia is made by reacting nitrogen with hydrogen in the presence of an iron catalyst.    the reaction is exothermic.    the equation for the reaction is shown.    n2  +  3h 2  \u2192  2nh 3    the bond energies are shown in the table.    bond bond energy in kj  / mol  h\u2013h 436  n\u2013h 390  n\u2261n 945    what is the energy given out during this reaction?  a \u20134593  kj / mol b \u20131083  kj / mol c \u2013959  kj / mol d \u201387  kj / mol    ",
            "7": "7  \u00a9 ucles 2017 0620/22/f/m/17 [turn over  13 the energy level diagram for the reaction between p and q to form r and s is shown.    energyp + q r + s     which row describes the energy changes involved and the type of reaction?     energy changes involved type of reaction  a   more energy is given out when the bonds in the products  are formed than is needed to break the bonds in the reactants endothermic    b   more energy is given out when the bonds in the products  are formed than is needed to break the bonds in the reactants exothermic    c   more energy is needed to break the bonds in the reactants  than is given out when the bonds in the products are formed endothermic    d   more energy is needed to break the bonds in the reactants  than is given out when the bonds in the products are formed exothermic        14 copper( ii) carbonate reacts with dilute sulfuric acid.    cuco 3(s)  +  h 2so 4(aq)  \u2192  cuso 4(aq)  +  co 2(g)  +  h 2o(l)    the rate of the reaction can be changed by varying the conditions.    which changes always increase the rate of this chemical reaction?    1 increasing the concentration of sulfuric acid  2 increasing the size of the pieces of copper( ii) carbonate  3 increasing the temperature  4 increasing the volume of sulfuric acid    a 1, 3 and 4 b 1 and 3 only c 2 and 3 d 3 and 4 only     15 which reaction is not affected by the presence of light?  a a candle burning  b methane reacting with chlorine  c photosynthesis  d silver bromide decomposing to form silver    ",
            "8": "8  \u00a9 ucles 2017 0620/22/f/m/17  16 the equation for the reversible reaction between hydrogen and iodine to form hydrogen iodide is  shown.     the colours of the reactants and products are shown.    h2(g)  +  i2(g)    2h i(g)   colourless purple colourless    the forward reaction is exothermic.    which statement is correct?  a an increase in pressure has no effect on the equilibrium position.  b the purple colour fades when the reaction mixture is heated.  c when equilibrium is reached, both forward and reverse reactions stop.  d when more hydrogen gas is added, the purple colour increases.      17 chlorine displaces bromine from a solution of potassium bromide.    cl 2  +  2kbr  \u2192  2kc l  +  br 2    what is the oxidising agent in this reaction?  a bromide ions  b bromine  c chloride ions  d chlorine      18 beryllium oxide  reacts with both sulfuric acid and aqueous sodium hydroxide.    which type of oxide is beryllium oxide?  a acidic   b amphoteric   c basic   d neutral     ",
            "9": "9  \u00a9 ucles 2017 0620/22/f/m/17 [turn over  19 a student investigates two acids w and x.    the same volumes of w and x are reacted separately with excess magnesium.    the student makes the following observations.    1 hydrogen gas is produced at a faster rate with w than with x.  2 the total volume of hydrogen gas produced is the same for both acids.    which statement explains these observations?  a the ph of w is higher than the ph of x.  b w is an organic acid.  c w is a stronger acid than x.  d w is more concentrated than x.     20 a student is given an unknown solution.    which two tests provide evidence that the solution is copper( ii) sulfate?    1 adding dilute hydrochloric acid  2 adding aqueous sodium hydroxide  3 adding dilute nitric acid, then silver nitrate solution  4 adding dilute nitric acid, then barium nitrate solution    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "10": "10  \u00a9 ucles 2017 0620/22/f/m/17  21 the diagram shows the steps in the preparation of a salt.    step 1 step 2 step 3 step 4    which salt is prepared by this method?  a barium sulfate  b copper( ii) sulfate  c potassium sulfate  d sodium sulfate     22 which property of elements increases across a period of the periodic table?  a metallic character  b number of electron shells  c number of outer shell electrons  d tendency to form positive ions     23 magnesium, calcium, strontium and barium are group ii elements.    group ii elements follow the same trends as group i elements.    which statements about group ii elements are correct?    1 calcium reacts faster than magnesium with water.  2 barium reacts less vigorously than magnesium with dilute acid. 3 strontium oxidises in air more slowly than barium.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "11": "11  \u00a9 ucles 2017 0620/22/f/m/17 [turn over  24 the noble gases are in group viii of the periodic table.    which statement explains why noble gases are unreactive?  a they all have eight electrons in their outer shells.  b they all have full outer shells.  c they are all gases.  d they are all monoatomic.     25 part of the periodic table is shown.    which element is used as a catalyst?    a c db     26 which statement about all metals is correct?  a they are attracted to a magnet.  b they are weak and brittle.  c they may be used to form alloys.  d they react with water.    27 which substance produces sulfur dioxide when roasted in air?  a bauxite  b cryolite  c hematite  d zinc blende    28 which metal carbonate does not produce carbon dioxide when it is heated with a bunsen  burner?  a copper( ii) carbonate  b magnesium carbonate  c sodium carbonate  d zinc carbonate ",
            "12": "12  \u00a9 ucles 2017 0620/22/f/m/17  29 two experiments are carried out.    in experiment 1, copper is heated with steam.     in experiment 2, copper( ii) oxide is heated with carbon.    steam copper experiment 1 experiment 2heatcopper( ii) oxide and carbon     which row describes what happens in experiments 1 and 2?     experiment 1 experiment 2  a no reaction no reaction  b no reaction reaction  c reaction no reaction  d reaction reaction     30 which two gases are obtained from liquid air by fractional distillation?  a carbon dioxide and oxygen  b carbon dioxide and water vapour  c nitrogen and oxygen   d nitrogen and water vapour     31 an experiment to find the percentage of oxygen in 150  cm3 of polluted air is shown.    waterdamp iron woolmeasuring cylinde r 150  cm3 of polluted air     the apparatus is left for one week.    after this time, the volume of gas in the measuring cylinder is 122  cm3.    what is the percentage of oxygen, to the nearest whole number, in the polluted air?  a 19% b 21% c 28% d 81% ",
            "13": "13  \u00a9 ucles 2017 0620/22/f/m/17 [turn over  32 two reactions, x and y, produce carbon dioxide.     x y  ch 4    co 2    caco 3    which types of reaction are x and y?     x y  a combustion combustion  b combustion thermal decomposition  c thermal decomposition combustion  d thermal decomposition thermal decomposition    33 the ions present in ammonium sulfate are formed from the products of the contact and haber  processes.    both of these processes involve the use of a catalyst.    which row is correct?     ion formed from process catalyst  a ammonium ammonia contact iron  b ammonium ammonia haber vanadium( v) oxide  c sulfate sulfuric acid contact vanadium( v) oxide  d sulfate sulfuric acid haber iron     34 the table shows the composition of four different types of petroleum.    fraction arabian heavy  /  % arabian light  / % iranian heavy  / % north sea  / %  gasoline 18 21 21 23  kerosene 11 15 13 15  diesel oil 18 21 20 24  fuel oil 53 43 46 38    which type of petroleum is best for the motor vehicle industry?  a arabian heavy  b arabian light  c iranian heavy  d north sea   ",
            "14": "14  \u00a9 ucles 2017 0620/22/f/m/17  35 which reaction of ethene is not an addition reaction?  a reaction with bromine  b reaction with hydrogen  c reaction with oxygen  d reaction with steam      36 ethanol is a fuel used in cars. it can be made from petroleum.     c 4h10  \u2192  c2h4  +  c 2h6 cracking   c 2h4  +  h 2o  \u2192  c2h5oh producing ethanol   c 2h5oh  +  3o 2  \u2192  2co 2  +  3h 2o burning    compounds of how many homologous series appear in these equations?  a 1 b 2 c 3 d 4      37 ethanol is produced from either ethene or sugar.    which type of chemical reaction is used in each case?     ethene \u2192 ethanol sugar \u2192 ethanol  a addition fermentation  b addition fractional distillation  c distillation fermentation  d distillation fractional distillation     38 the structural formula of an organic compound is shown.    ch 3ch 2cooch 3    what is the name of this compound?  a butanoic acid  b ethyl ethanoate  c methyl propanoate  d propyl methanoate     ",
            "15": "15    permission to reproduce items where third-par ty owned material protected by copyright is  included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holder s, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge asse ssment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/22/f/m/17  39 the diagram shows the structure of an important product.    ch hchh chh chh chh chh c     this product is formed by \u2026...  1 .\u2026.. of an .\u2026..  2 \u2026\u2026 .    which words complete gaps 1 and 2?     1 2  a addition polymerisation alkane  b addition polymerisation alkene  c cracking alkane  d cracking alkene      40 which pair of compounds reacts to form a condensation polymer?  a ch 3cooh and c 2h5nh 2  b hcooh and hoc 2h4oh  c hoc 6h12oh and hoocc 3h6cooh  d h 2nc 2h4nh 2 and hoc 3h6oh     ",
            "16": "16  \u00a9 ucles 2017 0620/22/f/m/17   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m17_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 theory (core) february/march 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib17 03_0620_32/4rp\u00a9 ucles 2017 *1726310751* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/f/m/17 \u00a9 ucles 2017 1 (a)  choose from the list of elements to answer the following questions. aluminium argon carbon lithium magnesium nickel nitrogen oxygen sulfur   each element can be used once, more than once or not at all.   which element  (i)  forms 21% of dry air,   ...   [1]  (ii)  reacts rapidly with cold water to produce hydrogen,   ...   [1]  (iii)  is in group iii of the periodic table,   ...   [1]  (iv)  has atoms which have a complete outer shell of electrons,   ...   [1]  (v)  is a transition element,   ...   [1]  (vi)  forms stable ions with a single positive charge?   ...   [1]  (b)  complete the table to show the number of electrons, neutrons and protons in the nickel atom  and oxide ion shown. number of electronsnumber of neutronsnumber of protons 62ni28 28 18o82\u2013 [4] [total: 10]",
            "3": "3 0620/32/f/m/17 \u00a9 ucles 2017 [turn over 2  the diagram shows a blast furnace for extracting iron. mixture of iron ore, coke and limestone (calcium carbonate ) slag molten iron  (a) (i)  on the diagram write \t \u25cf\t\tthe\tletter\ta to show where air is blown into the furnace, \t \u25cf\t\tthe\tletter\tw to show where waste gases exit the furnace. [2]  (ii)  how do you know from the information in the diagram that slag is less dense than molten  iron?   ...   [1]  (b)  limestone (calcium carbonate) is one of the raw materials added to the blast furnace.   calcium carbonate undergoes thermal decomposition in the blast furnace.  (i)  what is meant by the term thermal decomposition ?   .   ...   [2]  (ii)  complete the chemical equation for this reaction.  caco3    cao  +  ... [1]  (iii)  a further reaction in the blast furnace involves calcium oxide, cao.   describe this reaction and explain its importance.   .   ...   [2]",
            "4": "4 0620/32/f/m/17 \u00a9 ucles 2017  (c)  pure iron can be prepared by electrolysis of an aqueous solution of a suitable iron( ii) salt.   draw a labelled diagram of an electrolysis cell that could be used to carry out this reaction.  in your diagram include \t \u25cf\t the\telectrodes, \t \u25cf\t the\telectrolyte,\t \u25cf\t the\tpower\tsupply. [3]  (d) (i)  state the name of an element that could be used for the electrodes.   ...   [1]  (ii)  state one property that an electrode should have.   ...   [1]  (e)  pure iron can also be prepared by the thermal decomposition of iron pentacarbonyl.   the structure of iron pentacarbonyl is shown. fe cc cc co ooo o  (i)  write the formula for iron pentacarbonyl.   ...   [1]  (ii)  the word equation for the reaction is shown. iron pentacarbonyl    iron  +  carbon monoxide   explain why the gaseous product is hazardous.   ...   [1]",
            "5": "5 0620/32/f/m/17 \u00a9 ucles 2017 [turn over  (f)  the rate of rusting of iron varies with ph and temperature.  (i)  what two substances must be in contact with iron for it to rust?   ...   [2]  (ii)  the graph shows the rate of rusting at different ph values and temperatures. mass of rust  / g time  / hoursph 4, 30  \u00b0c ph 4, 20  \u00b0c ph 7, 30  \u00b0c ph 8, 30  \u00b0cph 7, 20  \u00b0c ph 8, 20  \u00b0c   how do ph and temperature affect the rate of rusting?  ph  ...  temperature   [2] [total: 19]",
            "6": "6 0620/32/f/m/17 \u00a9 ucles 2017 3  the hydrocarbons burnt in car engines react with air to form a mixture of gases.   the table shows the composition of the mixture of all the gases coming from a car exhaust. gas% of gas in the exhaust gases carbon dioxide 15 carbon monoxide 3 hydrocarbons 2 hydrogen 1 nitrogen oxides 1 oxygen 1 water vapour 18 gas x 59  (a)  identify gas x.   ..   [1]  (b)  carbon dioxide is formed when hydrocarbons such as octane are burnt in car engines.  (i)  what is meant by the term hydrocarbon ?   .   ...   [2]  (ii)  complete the word equation for this reaction.  octane  +  .    carbon dioxide  +  . [2]  (iii)  the concentration of carbon dioxide in the atmosphere is increasing.   explain why this is a global concern.   .   .   ...   [2]  (iv)  explain why carbon monoxide is present in the exhaust gases.   ...   [1]",
            "7": "7 0620/32/f/m/17 \u00a9 ucles 2017 [turn over  (v)  complete the table to calculate the relative molecular mass of octane, c8h18. number of atoms relative atomic massrelative mass in octane hydrogen 18 1 18 \u00d7 1 = 18 carbon relative molecular mass = ..  [2]  (c)  octane is an alkane.   the table shows some properties of different alkanes. alkane formulamelting point / \u00b0cboiling point / \u00b0c methane ch4 \u2013182 \u2013164 ethane c2h6 \u2013183 \u201388 propane c3h8 \u2013190 \u201342 butane c4h10 \u2013138 0 pentane c5h12 \u2013130 36  (i)  how does the boiling point of the alkanes change with the number of carbon atoms?   ...   [1]  (ii)  which alkane in the table is liquid at room temperature (20 \u00b0c)?   explain your answer.   .   ...   [2]  (iii)  draw the structure of methane showing all of the atoms and all of the bonds. [1] [total: 14]",
            "8": "8 0620/32/f/m/17 \u00a9 ucles 2017 4  ammonia is manufactured by combining nitrogen and hydrogen at high temperature and pressure. n2  +  3h2    2nh3  (a)  what does the symbol  mean?   ..   [1]  (b)  ammonia is used to make fertilisers.   explain why farmers spread fertilisers on the soil where they are going to grow crops.      ..   [1]  (c)  some fertilisers are salts made by adding acids to ammonia.   give the name of the compound formed when ammonia reacts with nitric acid.   ..   [1]  (d)  farmers use calcium oxide to treat acidic soils.  (i)  explain how calcium oxide helps treat acidic soils.   .   ...   [1]  (ii)  suggest why farmers need to treat soils which are too acidic.   .   ...   [1] [total: 5]",
            "9": "9 0620/32/f/m/17 \u00a9 ucles 2017 [turn over 5\t\tlavandulol\tis\ta\tcompound\tfound\tin\tlavender\tflowers.   the structure of lavandulol is shown. cch ch3 ch3ch2ch2 ch2ch3coh ch  (a)  on the diagram, draw a circle around the alcohol functional group. [1]  (b)  how many carbon atoms are there in one molecule of lavandulol?   ..   [1]  (c) (i)  what feature of the lavandulol structure shows that it is unsaturated?   ...   [1]  (ii)  describe a test to show that lavandulol is unsaturated.   test  ..   result  ... [2]  (d)\t\tlavandulol\tcan\tbe\textracted\tfrom\tlavender\tflowers.   the following statements are about the procedure for extracting lavandulol.  a  stir the mixture and leave it for a few hours.  b  filter off the solid from the solution.  c  distil the solution.  d  add solvent to the ground up lavender flowers.  e  grind up the lavender flowers.   put the statements a, b, c, d and e in the correct order. \t \tthe\tfirst\tone\thas\tbeen\tdone\tfor\tyou. e [2]",
            "10": "10 0620/32/f/m/17 \u00a9 ucles 2017  (e)  chromatography can be used to separate the coloured pigments extracted from lavender  flowers.\tthe\tapparatus\tused\tis\tshown. solventchromatography ja rcover chromatography paper baseline \t \tafter\ta\tfew\tminutes\tthe\tsolvent\tvapour\tfills\tthe\twhole\tchromatography\tjar.   use the kinetic particle model to explain this.               ..   [3]  (f)  three different dye mixtures, p, q and r, were placed on a sheet of chromatography paper.   two pure dyes, x and y, were also placed on the same piece of chromatography paper.  the experiment was carried out and the results are shown. pqrx y  (i)  where were the dyes placed on the chromatography paper at the start of the experiment?   ...   [1]  (ii)  which dye mixture contained the greatest number of dyes?   ...   [1]  (iii)  which dye mixture contained both dye x and dye y?   ...   [1] [total: 13]",
            "11": "11 0620/32/f/m/17 \u00a9 ucles 2017 [turn over 6  chlorine and sodium hydroxide are manufactured by the electrolysis of concentrated aqueous  sodium chloride.  (a)  chlorine is produced at the positive electrode (anode).   name the substance produced at the negative electrode (cathode) during the electrolysis.   ..   [1]  (b)  state the name of the particle that is removed from a chloride ion to make a chlorine atom.   ..   [1]  (c)  complete the electronic structure of a chlorine molecule. cl cl [2]  (d)  describe a test for chlorine.  test  .  result  .. [2]  (e)  if chlorine reacts with sodium hydroxide, sodium chlorate( i), naocl, is formed. another  compound of sodium is also produced. this forms a white precipitate on addition of aqueous silver nitrate.   complete the chemical equation for this reaction. cl  2  +  ..naoh    naocl  +    +  h2o [2]",
            "12": "12 0620/32/f/m/17 \u00a9 ucles 2017  (f)  1000 g of a solution produced by the electrolysis of concentrated aqueous sodium chloride  contains the following masses of compounds. compoundmass of substance present / g sodium chlorate( i) 300 sodium chloride 6 sodium hydroxide 9 water 685 total 1000  (i)  calculate the mass of sodium hydroxide present in 200 g of this solution. [1]  (ii)  all the water from the 1000 g of solution is evaporated.   deduce the mass of the remaining mixture. [1] [total: 10]",
            "13": "13 0620/32/f/m/17 \u00a9 ucles 2017 [turn over 7  metals have characteristic properties.  (a)  write about the properties of metals.   in your answer \t \u25cf\t \trefer\tto\tthe\tphysical\tproperties\twhich\tare \tcharacteristic\tof\tmetals, \t \u25cf\t \trefer\tto\tthe\tchemical\tproperties\twhich\tare\tcharacteristic\tof\tmetals, \t \u25cf\t \tinclude\ta\tword\tequation\tto\tshow\ta\tchemical\treaction\tof\ta\tmetal.                     ..   [5]  (b)  the table shows how easy it is to reduce four metal oxides. metal oxide ease of reduction calcium oxide not reduced by carbon at 1600 \u00b0c magnesium oxide reduced by carbon at 1600 \u00b0c nickel( ii) oxide reduced by carbon at 350 \u00b0c zinc oxide reduced by carbon at 850 \u00b0c   use this information to put the metals in order of their reactivity. put the least reactive metal  first. least reactive most reactive [2]  (c)  uranium is a radioactive metal which has several isotopes.  (i)  what is the meaning of the term isotopes?   .   ...   [1]  (ii)  give the main use of the isotope 235u.   ...   [1] [total: 9]",
            "14": "14 0620/32/f/m/17 \u00a9 ucles 2017blank page",
            "15": "15 0620/32/f/m/17 \u00a9 ucles 2017blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.",
            "16": "16 0620/32/f/m/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_m17_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/42   paper 4 theory (extended) february/march 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib17 03_0620_42/3rp\u00a9 ucles 2017 *6232664619* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/f/m/17 \u00a9 ucles 2017 1 (a)  five organic compounds have the following structures. hc ch hhha hhhh cch hc chhhb hhh cch br cch hh hd br br cch hhe h hhcbrcchhhc hhhh cch  (i)  which compound is butane?   ...   [1]  (ii)  which two compounds are structural isomers of each other?   ...   [1]  (iii)  which compound can be made by reacting an alkene with bromine?   ...   [1]  (iv)  which compound is a saturated hydrocarbon?   ...   [1]  (v)  which compound has the empirical formula c2h5?   ...   [1]  (vi)  name the two products made during the complete combustion of compound c.   ...   [1]",
            "3": "3 0620/42/f/m/17 \u00a9 ucles 2017 [turn over  (b)  petroleum can be separated into useful substances using the apparatus shown. x ynaphtha fractiongasoline fractionrefinery gas diesel oil fraction fuel oil fraction petroleum lubricating fraction and bitumen  (i)  name the fraction which is the most viscous.   ...   [1]  (ii)  name the fraction with the smallest molecules.   ...   [1]  (iii)  name the fraction which has the weakest attractive forces between molecules.   ...   [1]  (iv)  fraction x is used as jet fuel.  name fraction x.   ...   [1]  (v)  what happens at point y on the diagram?   ...   [1] [total: 11]",
            "4": "4 0620/42/f/m/17 \u00a9 ucles 2017 2  silver dichromate, ag2cr2o7, is a red insoluble salt.   silver dichromate can be made by reacting silver nitrate solution with ammonium dichromate  solution. the chemical equation for the reaction is shown. 2agno3(aq)  +  (nh4)2cr2o7(aq)    2nh4no3(aq)  +  ag2cr2o7(s)  (a)  describe how you could obtain pure dry solid silver dichromate after mixing silver nitrate solution and ammonium dichromate solution.            ..   [3]  (b) (i)  the charge on a silver ion is +1.   deduce the charge on the dichromate ion in ag 2cr2o7.   ...   [1]  (ii)  write the ionic equation for the formation of silver dichromate in this reaction.   state symbols are not required.   ...   [1]  (c)  dilute aqueous sodium hydroxide was added to the ammonium nitrate solution made in the  reaction. the mixture was then warmed and damp universal indicator paper was held above the mixture.   state and explain what would happen to the universal indicator paper.         ..   [2]",
            "5": "5 0620/42/f/m/17 \u00a9 ucles 2017 [turn over  (d)  the apparatus shown was set up. solid silver nitrate solid ammonium dichromateplastic troug h waters \t \tafter\tfive\tminutes,\ta\tred\tsolid\tappeared\talong\tthe\tline\tmarked\t s on the diagram.  (i)  explain why a red solid appeared along the line marked s.   .   .   .   ...   [3]  (ii)  the experiment was repeated at a higher temperature.   what effect, if any, would this have on the time taken for the red solid to appear? explain  your answer.   .   ...   [2]  (e)  ammonium dichromate, (nh4)2cr2o7, undergoes thermal decomposition.   the products are chromium( iii) oxide, nitrogen and water.  (i)  what is meant by thermal decomposition?   .   ...   [2]  (ii)  write a chemical equation for the thermal decomposition of ammonium dichromate.   ...   [2] [total: 16]",
            "6": "6 0620/42/f/m/17 \u00a9 ucles 2017 3  nitryl chloride, no2cl, reacts with nitric oxide, no. the forward reaction is exothermic. no2cl (g)  +  no(g)    no2(g)  +  nocl (g)   the reaction can reach equilibrium.  (a)  what is meant by the term equilibrium  for a reversible reaction?         ..   [2]  (b)  explain why increasing the temperature increases the rate of reaction.         ..   [3]  (c) state and explain the effect, if any, of increasing the temperature on the position of equilibrium.         ..   [2]  (d)  state and explain the effect, if any, of decreasing the pressure on the position of equilibrium.         ..   [2]",
            "7": "7 0620/42/f/m/17 \u00a9 ucles 2017 [turn over  (e)  nitrosyl chloride, noc l, is a gas at room temperature. it has the structure shown. on cl  (i)  complete the dot-and-cross diagram to show the arrangement of the outer shell electrons  in nitrosyl chloride. cl n o [2]  (ii)  nitrosyl chloride has a boiling point of \u20136  \u00b0c.   explain why nitrosyl chloride has a low boiling point.   .   .   ...   [2] [total: 13]",
            "8": "8 0620/42/f/m/17 \u00a9 ucles 2017 4  copper( ii) sulfate solution was electrolysed using the apparatus shown. +\u2013 carbon cathode carbon anode copper( ii) sulfate solution  (a) (i)  draw an arrow on the diagram to show the direction of movement of electrons in the wire.   label the arrow a. [1]  (ii)  draw an arrow on the diagram to show the direction of movement of positive ions in the  copper( ii) sulfate solution.   label the arrow b. [1]  (b)  oxygen was formed at the anode and copper was formed at the cathode.  (i)  the ionic half-equation for the formation of oxygen is shown. 4oh\u2013    o2  +  2h2o  +  4e\u2013   explain why this reaction is oxidation.   ...   [1]  (ii)  write the ionic half-equation for the formation of copper at the cathode.   ...   [2]  (c)  the electrolysis was repeated using copper electrodes in place of carbon electrodes.   state and explain what happens to the masses of the anode and the cathode during this  electrolysis.               ..   [4] [total: 9]",
            "9": "9 0620/42/f/m/17 \u00a9 ucles 2017 [turn over 5  iron is extracted from its ore using a blast furnace.  (a)  in the blast furnace, coke burns in oxygen to produce heat energy and carbon dioxide.   how is this carbon dioxide converted into carbon monoxide in the blast furnace?   ..   [1]  (b)  calcium carbonate added to the blast furnace decomposes to form calcium oxide.   calcium oxide removes silicon( iv) oxide impurities from the iron in a neutralisation reaction.   write a chemical equation for the reaction of calcium oxide with silicon( iv) oxide. suggest why  it is a neutralisation reaction.         ..   [3]  (c)  the main impurity in iron obtained from the blast furnace is carbon.  (i)  why must the high levels of carbon be lowered before the iron becomes a useful material?   ...   [1]  (ii)  how is the carbon removed from the iron?   .   ...   [1]  (d)\t\tzinc\tis\textracted\t from\tits\tore.\tthe\tore\tcontains\t zinc\tsulfide.\tthe\tzinc\tsulfide\tis\troasted\tin\tair\tto\t produce zinc oxide and sulfur dioxide.   zinc is then obtained from the zinc oxide using a blast furnace.  (i)\t\tgive\tthe\tname\tof\tthe\tore\tof\tzinc\tthat\tcontains\tzinc\tsulfide.   ...   [1]  (ii)\t\twrite\ta\tchemical\t equation\t for\tthe\treaction\t that\ttakes\tplace\twhen\tzinc\tsulfide\tis\troasted\tin\t air.   ...   [1]  (iii)  suggest why the sulfur dioxide should not be released into the atmosphere.   .   ...   [2]",
            "10": "10 0620/42/f/m/17 \u00a9 ucles 2017  (iv)  the temperature inside the blast furnace in which zinc is extracted is about 1000 \u00b0c.   the table gives some information about substances in the blast furnace in which zinc is  extracted. substance melting point / \u00b0c boiling point / \u00b0c carbon sublimes at 4330 \u00b0c silicon( iv) oxide 1610 2230 zinc 420 907   use the data in the table to explain why the zinc obtained does not contain high levels of  impurities such as silicon( iv) oxide and carbon.   .   .   ...   [2] [total: 12]",
            "11": "11 0620/42/f/m/17 \u00a9 ucles 2017 [turn over 6  barium carbonate decomposes when heated. baco3(s)    bao(s)  +  co2(g)  (a)  a student heated a 10.0 g sample of barium carbonate until it was fully decomposed.  (i)  calculate the number of moles of barium carbonate the student used. moles of barium carbonate = . mol  [2]  (ii)  calculate the volume of carbon dioxide gas produced at room temperature and pressure.  give your answer in dm3. volume of carbon dioxide = . dm3  [1]  (b)  the student added 2.00 g of the barium oxide produced to water. bao  +  h2o    ba(oh)2   calculate the mass of barium hydroxide that can be made from 2.00 g of barium oxide. the mr  of ba(oh)2 is 171. mass of barium hydroxide = . g  [1]  (c)  a 1.50 g sample of barium hydroxide was dissolved in water. the total volume of the solution  was 100 cm3.   a 25.0 cm3 portion of the barium hydroxide solution was titrated against hydrochloric acid. the  volume of hydrochloric acid required was 18.75 cm3. ba(oh)2  +  2hcl    bacl 2  +  2h2o  (i)  calculate how many moles of barium hydroxide were in the 25.0 cm3 portion used in the  titration. moles of barium hydroxide = . mol  [1]  (ii)  calculate the concentration of the hydrochloric acid used. concentration of hydrochloric acid = . mol / dm3  [2] [total: 7]",
            "12": "12 0620/42/f/m/17 \u00a9 ucles 2017 7 (a)  the diagram shows part of the structure of an addition polymer. ch hccl hch hccl hch hccl h  (i)  draw a circle around one repeat unit of the polymer. [1]  (ii)  draw the structure of the monomer from which this addition polymer is made. [1]  (iii)  aqueous bromine is added to both the polymer and the monomer.   describe what would be seen in each case.  with the polymer  .  with the monomer  ... [2]  (b)  the diagram shows part of the structure of a condensation polymer. co co c co o n hn hn hn h  (i)  what type of condensation polymer is this?   ...   [1]  (ii)  on the diagram, draw a circle around one repeat unit of the polymer. [1]  (iii)  draw the structures of the two monomers from which the condensation polymer is made. [2]",
            "13": "13 0620/42/f/m/17 \u00a9 ucles 2017 [turn over  (c)  hydrolysis of a polymer gave a compound with the following composition by mass:  c, 34.61%;   h, 3.85%;  o, 61.54%.  (i)  calculate the empirical formula of the compound. empirical formula =   [3]  (ii)  what additional information is needed to calculate the molecular formula of the compound?   .   ...   [1] [total: 12]",
            "14": "14 0620/42/f/m/17 \u00a9 ucles 2017blank page",
            "15": "15 0620/42/f/m/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.blank page",
            "16": "16 0620/42/f/m/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_m17_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 7 and 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test february/march 2017  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 8 printed pages. [turn overib17 03_0620_52/5rp\u00a9 ucles 2017 *5444126075* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/52/f/m/17 \u00a9 ucles 2017 1  you are going to investigate the reaction between dilute hydrochloric acid and two different aqueous  solutions of sodium hydroxide labelled solution o and solution p.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a)  experiment 1 \t \u25cf\t \tfill\tthe\tburette\tup\tto\tthe\t0.0\t cm3 mark with dilute hydrochloric acid. \t \u25cf\t \tuse\tthe\tmeasuring\tcylinder\tto\tpour\t20\t cm3 of solution o into the conical flask. \t \u25cf\t \tadd\t10\tdrops\tof\tthymolphthalein\tindicator\tto\tthe\tconical\tflask. \t \u25cf\t \tadd\tthe\tdilute\thydrochloric\t acid\tfrom\tthe\tburette\t1\tcm3 at a time, while swirling the flask,  until the solution just changes colour. \t \u25cf\t \trecord\tthe\tburette\treadings\tin\tthe\ttable.  (b)  experiment 2 \t \u25cf\t \tfill\tthe\tburette\tup\tto\tthe\t0.0\t cm3 mark with dilute hydrochloric acid. \t \u25cf\t \tempty\tthe\tconical\tflask\tand\trinse\tit\twith\t distilled\twater. \t \u25cf\t \tuse\tthe\tmeasuring\tcylinder\tto\tpour\t20\t cm3 of solution p into the conical flask. \t \u25cf\t \tadd\t10\tdrops\tof\tthymolphthalein\tindicator\tto\tthe\tconical\tflask. \t \u25cf\t \tadd\tthe\tdilute\thydrochloric\t acid\tfrom\tthe\tburette\t1\tcm3 at a time, while swirling the flask,  until the solution just changes colour. \t \u25cf\t \trecord\tthe\tburette\treadings\tin\tthe\ttable \tand\tcomplete\tthe\ttable. experiment\t1 experiment\t2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 [4]  (c)\t\twhat\tcolour\tchange\twas\tobserved\tin\tthe\tconical\tflask\tin\texperiment\t1?  from  to   \t\t[1]  (d)  what type of chemical reaction occurs when dilute hydrochloric acid reacts with  sodium\thydroxide\tsolution?   .. \t\t[1]",
            "3": "3 0620/52/f/m/17 \u00a9 ucles 2017 [turn over  (e) (i)  which solution of sodium hydroxide, solution o or solution p,\t is\tthe\tmore\tconcentrated?\t explain\tyour\tanswer.   .   ... \t\t[2]  (ii)  how many times more concentrated is this solution of sodium hydroxide than the other  solution\tof\tsodium\thydroxide?   ... \t\t[1]  (f)\t\tif\texperiment\t 2\twere\trepeated\t using\t10\tcm3 of solution p, what volume of dilute hydrochloric acid  would\tbe\tneeded?   .. \t\t[2]  (g)\t\twhat\twould\tbe\tthe\teffect,\tif\tany,\ton\tthe\tvolume\tof\tdilute\thydrochloric\t acid\tused\tin\texperiment\t 1\t if the solution of sodium hydroxide were warmed\t before\tadding\tthe\tdilute\thydrochloric\t acid?\t give a reason for your answer.  effect on volume    reason   [2]  (h) (i)  what would be a more accurate method of measuring the volume of the sodium hydroxide  solution?   ... \t\t[1]  (ii)  suggest how the reliability of the results could be checked.   ... \t\t[1]  (i)\t\taqueous\t sodium\thydroxide\t reacts\twith\taqueous\t calcium\t chloride\t to\tform\ta\tprecipitate\t of\t calcium hydroxide. \t \tuse\tthis\tinformation\t to\tsuggest\t a\tdifferent\t method\tof\tfinding\tout\twhich\tof\tthe\tsolutions\t of\t sodium hydroxide is the more concentrated.            ..   [3] [total:\t18]",
            "4": "4 0620/52/f/m/17 \u00a9 ucles 2017 2  you are provided with two solids q and r which are both salts.   carry out the following tests on each solid, recording all of your observations at each stage.  tests on solid q  (a)  describe the appearance of solid q.   .. \t\t[1] \t\tadd\tabout\t10\t cm3 of distilled water to all of solid q in the test-tube and shake to dissolve the solid.   divide the solution into three equal portions in three test-tubes and carry out the following tests.  (b) (i)\t \tto\tthe\tfirst\t portion\tof\t the\tsolution,\tadd\tdrops\tof\t aqueous\tsodium\thydroxide\tuntil\ta\tchange\t is seen. \t \trecord\tyour\tobservations.   ... \t\t[2]  (ii)  now add an excess of aqueous sodium hydroxide to the mixture. \t \trecord\tyour\tobservations.   ... \t\t[1]  (c) (i)  to the second portion of the solution, add drops of aqueous ammonia until a change is  seen. \t \trecord\tyour\tobservations.   ... \t\t[2]  (ii)  now add an excess of aqueous ammonia to the mixture. \t \trecord\tyour\tobservations.   ... \t\t[1]  (d)\t\tto\tthe\tthird\tportion\tof\tthe\tsolution,\t add\ta\tfew\tdrops\tof\tdilute\tnitric\tacid\tand\tabout\t1\tcm3 of  aqueous silver nitrate. \t \trecord\tyour\tobservations.   .. \t\t[1]   keep your mixture from test (d) to compare the result with test (h).  (e)  identify solid q.   .. \t\t[2]",
            "5": "5 0620/52/f/m/17 \u00a9 ucles 2017 [turn over  tests on solid r  (f)\t\tcarry\tout\ta\tflame\ttest\ton\tsolid\tr. \t \trecord\tyour\tobservations.   .. \t\t[1]   dissolve the rest of solid r in about 5 cm3 of distilled water in a test-tube. shake the mixture to  dissolve the solid. divide the solution into two equal portions in two test-tubes.  (g)\t\tto\tthe\tfirst\tportion\tof\tthe\tsolution,\t add\ta\tfew\tdrops\tof\tdilute\tnitric\tacid\tand\tabout\t1\tcm3 of  aqueous barium nitrate. \t \trecord\tyour\tobservations.   .. \t\t[1]  (h)\t\tto\tthe\tsecond\tportion\tof\tthe\tsolution,\t add\ta\tfew\tdrops\tof\tdilute\tnitric\tacid\tand\tabout\t1\tcm3 of  aqueous silver nitrate.   compare the result with test (d).\trecord\tyour\tobservations\tfor\ttest\t(h).   .. \t\t[2]  (i)  identify solid r.   .. \t\t[2] [total:\t16]",
            "6": "6 0620/52/f/m/17 \u00a9 ucles 2017 3  when solid barium hydroxide is added to solid ammonium chloride a reaction takes place.  (a)  describe an experiment to show that this reaction is endothermic.                  ..   [4]  (b)\t\thow\tcould\tyou\tshow\twhether\tor\tnot\tthe\tfinal\tmixture\tcontains\tammonium\tions?            .. \t\t[2] [total:\t6]",
            "7": "7 0620/52/f/m/17 \u00a9 ucles 2017notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "8": "8 0620/52/f/m/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_m17_qp_62.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib17 03_0620_62/6rp \u00a9 ucles 2017 *6948987238* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/62   paper 6 alternative to practical february/march 2017  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/f/m/17 \u00a9 ucles 2017 1  a student investigated the gases formed during the electrolysis of dilute sulfuric acid using the  apparatus shown.   hydrogen and oxygen were produced. dilute sulfuric acidcarbon  +\u2013  (a)  complete the box to name the apparatus used. [1]  (b)  on the diagram, sketch how a sample of one of the gases could be collected.  [2]  (c)  give a test for oxygen.  test  .  result  .. [1]  (d)  the gas collected at the positive side turned limewater milky.  (i)  based on this observation, what gas was present?   ...   [1]  (ii)  suggest how this gas was formed.   ...   [1]  (e)  a solution of dilute sulfuric acid was electrolysed for 1 hour.   suggest why the ph of the solution decreased  during the electrolysis.      ..   [2] [total: 8]",
            "3": "3 0620/62/f/m/17 \u00a9 ucles 2017 [turn over question 2 starts on the next page.",
            "4": "4 0620/62/f/m/17 \u00a9 ucles 2017 2  a student investigated the reaction between dilute hydrochloric acid and two different aqueous  solutions of sodium hydroxide labelled solution o and solution p.   two experiments were carried out.   experiment 1 \t \u25cf\t \ta\tburette\twas\tfilled\twith\tdilute\thydrochloric\tacid.\t the\tinitial\tburette\treading\twas\trecorded. \t \u25cf\t \tusing\ta\tmeasuring\tcylinder,\t20\t cm3 of solution o\twere\tpoured\tinto\ta\tconical\tflask. \t \u25cf\t \tthymolphthalein\tindicator\twas\tadded\tto\tthe\tconical\tflask. \t \u25cf\t \tthe\tdilute\thydrochloric\t acid\twas\tadded\tfrom\tthe\tburette,\t while\tswirling\t the\tflask,\tuntil\tthe\t solution\tjust\tchanged\tcolour.\t the\tfinal\tburette\treading\twas\trecorded.  (a)\t use\tthe\tburette\tdiagrams\tto\trecord\tthe\treadings\tin\t the\ttable\tand\tcomplete\tthe\ttable. 3 4 5 initial reading29 30 31 final reading final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 [2]   experiment 2 \t \u25cf\t \tthe\tconical\tflask\twas\temptied\tand\trinsed\twith\tdistilled\twater. \t \u25cf\t \texperiment\t1\twas\trepeated\tusing\tsolution\t p instead of solution o.  (b)\t\tuse\tthe\tburette\tdiagrams\tto\trecord\tthe\treadings\tin\tthe\ttable\tand\tcomplete\tthe\ttable. 23 24 25 initial reading29 30 31 final reading final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 [2]",
            "5": "5 0620/62/f/m/17 \u00a9 ucles 2017 [turn over  (c)  what type of chemical reaction occurs when dilute hydrochloric acid reacts with  sodium hydroxide solution?   ..   [1]  (d) (i)  which solution of sodium hydroxide, solution o or solution p, is the more concentrated? explain\tyour\tanswer.   .   ...   [2]  (ii)  how many times more concentrated is this solution of sodium hydroxide than the other solution of sodium hydroxide?   ...   [1]  (e)\t\tif\texperiment\t 2\twere\trepeated\t using\t10\tcm 3 of solution p, what volume of dilute hydrochloric acid  would be needed?   ..   [2]  (f)\t\twhat\twould\tbe\tthe\teffect,\tif\tany,\ton\tthe\tvolume\tof\tdilute\thydrochloric\t acid\tused\tin\texperiment\t 1\t if the solution of sodium hydroxide were warmed before adding the dilute hydrochloric acid?  give a reason for your answer.  effect on volume    reason   [2]  (g) (i)  what would be a more accurate method of measuring the volume of the aqueous sodium  hydroxide solution?   ...   [1]  (ii)  suggest how the reliability of the results could be checked.   ...   [1]  (h)  aqueous sodium hydroxide reacts with aqueous calcium chloride to form a precipitate of  calcium hydroxide. \t \tuse\tthis\tinformation\t to\tsuggest\t a\tdifferent\t method\tof\tfinding\tout\twhich\tof\tthe\tsolutions\t of\t sodium hydroxide is the more concentrated.            ..   [3] [total: 17]",
            "6": "6 0620/62/f/m/17 \u00a9 ucles 2017 3  two solids, q and r, which are both salts, were analysed. solid q was zinc bromide.   tests were carried out on each solid.  tests on solid q   solid q was dissolved in distilled water.   the solution was divided into three equal portions in three test-tubes, and the following tests were  carried out.   complete the expected observations.  (a) (i)\t \tdrops\tof\taqueous\t sodium\thydroxide\t were\tadded\tto\tthe\tfirst\tportion\tof\tthe\tsolution\tuntil\ta\t change was seen.  observations  .   [2]  (ii)\t\texcess\taqueous\tsodium\thydroxide\twas \tthen\tadded\tto\tthe\tmixture.  observations  .   [1]  (b) (i)  drops of aqueous ammonia were added to the second portion of the solution until a change  was seen.  observations  .   [1]  (ii)\t\texcess\taqueous\tammonia\twas\tthen\tadded\tto\tthe\tmixture.  observations  .   [1]  (c)  dilute nitric acid and aqueous silver nitrate were added to the third portion of the solution.  observations     [2]",
            "7": "7 0620/62/f/m/17 \u00a9 ucles 2017 [turn over   tests on solid r  tests were carried out and the following observations made. tests on solid r observations test 1 a\tflame\ttest\twas\tcarried\tout\ton\tsolid\t r. yellow colour solid r was dissolved in distilled water. the  solution was divided into two equal portions in two test-tubes. test 2 dilute nitric acid and aqueous barium nitrate  were\tadded\tto\tthe\tfirst\tportion\tof\tthe\tsolution.no change test 3 dilute nitric acid and aqueous silver nitrate  were added to the second portion of the solution.yellow precipitate formed  (d)  identify solid r.   ..   [2] [total: 9]",
            "8": "8 0620/62/f/m/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 4  when solid barium hydroxide is added to solid ammonium chloride a reaction takes place.    (a)  describe an experiment to show that this reaction is endothermic.                  ..   [4]  (b)\t\thow\tcould\tyou\tshow\twhether\tor\tnot\tthe\tfinal\tmixture\tcontains\tammonium\tions?            ..   [2] [total: 6]"
        },
        "0620_s17_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ireland as a cambridge international level1/level 2 certificate .  this document consists of 14 printed pages and 2 blank pages.  ib17 06_0620_11/fp  \u00a9 ucles 2017 [turn over     *2950887077* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice (core)  may/june 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a mark will not be deducted for a wrong answer. any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/11/m/j/17  1 the diagram shows some changes of state.    solid liquid gasp q rs    which words describe the changes of state, p, q, r and s?     p q r s  a freezing boiling melting evaporation  b melting evaporation freezing condensation  c melting sublimation freezing evaporation  d sublimation evaporation melting condensation     2 the diagram shows part of a thermometer.    31 30    what is the reading on the thermometer?  a 30.2 b 30.3 c 31.7 d 31.8      3 pure water has a boiling point of 100  \u00b0c and a freezing point of 0  \u00b0c.    what is the boiling point and freezing point of a sample of aqueous sodium chloride?     boiling point  / \u00b0c freezing point  / \u00b0c  a 98 \u20132  b 98 2  c 102 \u20132  d 102 2     ",
            "3": "3  \u00a9 ucles 2017 0620/11/m/j/17 [turn over  4 pure copper( ii) sulfate crystals can be made by adding copper( ii) oxide to hot dilute sulfuric acid.    the copper( ii) oxide is added until it ..1.. .    the solution is ..2.. and then ..3.. to obtain the pure crystals.    which words complete gaps 1, 2 and 3?     1 2 3  a is in excess cooled filtered  b is in excess filtered cooled  c changes colour cooled filtered  d changes colour filtered cooled     5 which part of an atom has a relative mass of 1 and a relative charge of 0?  a electron  b neutron  c nucleus  d proton      6 which molecule contains exactly two single covalent bonds?  a c l  2 b ch 4 c h 2o d hc l     7 sodium reacts with chlorine to form sodium chloride.    which statements describe what happens to the sodium atoms in this reaction?    1 sodium atoms form positive ions.  2 sodium atoms form negative ions.  3 sodium atoms gain electrons.  4 sodium atoms lose electrons.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "4": "4  \u00a9 ucles 2017 0620/11/m/j/17  8 diamond is extremely hard and does not conduct electricity.    which statement explains these properties?  a it has a lattice of positive carbon ions in a \u2018sea of electrons\u2019.  b it has delocalised electrons and each carbon atom forms three covalent bonds with other  carbon atoms.  c it has no delocalised electrons and each carbon atom forms four covalent bonds with other  carbon atoms.  d it has strong ionic bonds between each carbon atom.     9 what is the relative formula mass of ammonium nitrate, nh 4no 3?  a 80 b 108 c 122 d 150     10 concentrated aqueous sodium chloride is electrolysed.   what is the main product formed at the positive electrode (anode)?  a chlorine  b hydrogen  c oxygen  d sodium      11 some properties of four fuels are shown in the table.    which fuel is a gas at room temperature and makes two products when it burns in a plentiful supply of air?     fuel formula melting point  /  \u00b0c boiling point  / \u00b0c  a hydrogen h 2 \u2013259 \u2013253  b methane ch 4 \u2013182 \u2013164  c octane c 8h18 \u201357 126  d wax c 31h64 60 400    ",
            "5": "5  \u00a9 ucles 2017 0620/11/m/j/17 [turn over  12 which statements about exothermic and endothermic reactions are correct?    1 during an exothermic reaction, heat is given out.  2 the temperature of an endothermic reaction goes up because heat is taken in.  3 burning methane in the air is an exothermic reaction.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     13 when sulfur is heated it undergoes a ..1.. change as it melts.    further heating causes the sulfur to undergo a ..2.. change and form sulfur dioxide.    which words complete gaps 1 and 2?     1 2  a chemical chemical  b chemical physical  c physical chemical  d physical physical    14 which row correctly matches the experiment and observations to the identity of the underlined  substance?     experiment and observations identity of the underlined substance  a   blue crystals are heated. the crystals  turn white and steam is given off. hydrated cobalt( ii) chloride    b   pink crystals are heated. the crystals  turn blue and steam is given off. anhydrous cobalt( ii) chloride    c   water is added to a blue solid.  the blue solid turns pink. hydrated copper( ii) sulfate    d   water is added to a white solid.  the white solid turns blue. anhydrous copper( ii) sulfate      ",
            "6": "6  \u00a9 ucles 2017 0620/11/m/j/17  15 a student was investigating the reaction between marble chips and dilute hydrochloric acid.    bung marble chips 25 cm3 of dilute hydrochloric acidgas syringe     which changes slow down the rate of reaction?     temperature  of acid concentration  of acid surface area  of marble chips  a decrease decrease decrease  b decrease decrease increase  c increase decrease decrease  d increase increase increase     16 the reactions shown may occur in the air during a thunder-storm.    n 2  +  o 2  o  2no  2no  +  o 2  o  2no 2  no  +  o 3  o  no 2  +  o 2    which row shows what happens to the reactant molecules in each of these reactions?     n2 no o 3  a oxidised oxidised oxidised  b oxidised oxidised reduced  c reduced reduced oxidised  d reduced reduced reduced     ",
            "7": "7  \u00a9 ucles 2017 0620/11/m/j/17 [turn over  17 hydrochloric acid is added to magnesium metal and to sodium carbonate in separate tests.    which row shows the observations?     magnesium metal sodium carbonate  a effervescence effervescence  b effervescence no reaction  c no reaction effervescence  d no reaction no reaction      18 which oxide dissolves in water to form a basic solution?  a carbon dioxide  b nitrogen dioxide  c sodium oxide  d sulfur dioxide     19 which salt preparation uses a burette and a pipette?  a calcium nitrate from calcium carbonate and nitric acid  b copper( ii) sulfate from copper( ii) hydroxide and sulfuric acid  c potassium chloride from potassium hydroxide and hydrochloric acid  d zinc chloride from zinc and hydrochloric acid      20 substance x reacts with warm dilute hydrochloric acid to produce a gas which decolourises  acidified aqueous potassium manganate( vii).    substance x gives a yellow flame in a flame test.    what is x?  a potassium chloride  b potassium sulfite  c sodium chloride  d sodium sulfite    ",
            "8": "8  \u00a9 ucles 2017 0620/11/m/j/17  21 part of the periodic table is shown.    which element is a soft solid that reacts violently with cold water?    dca b       22 which element is less reactive than the other members of its group in the periodic table?  a astatine  b caesium  c fluorine  d rubidium     23 an element has the following properties.    \u0263 it forms coloured compounds.  \u0263 it acts as a catalyst.  \u0263 it melts at 1539  \u00b0c.    in which part of the periodic table is the element found?  a group i  b group vii  c group viii  d transition elements     24 why are weather balloons sometimes filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen.  c helium is more dense than hydrogen.  d helium is unreactive.     ",
            "9": "9  \u00a9 ucles 2017 0620/11/m/j/17 [turn over  25 element e:    \u2022 forms an alloy  \u2022 has a basic oxide  \u2022 is below hydrogen in the reactivity series.    what is e?  a carbon  b copper  c sulfur  d zinc     26 some reactions of three metals and their oxides are shown.    metal metal reacts with dilute  hydrochloric acid metal oxide  reacts with carbon  s no yes  t yes no  u yes yes    what is the order of reactivity of the metals?     least  reactive  most  reactive  a s t u  b s u t  c t s u  d u t s      27 which statement about the extraction of iron in a blast furnace is not correct?  a calcium oxide reacts with acidic impurities.  b iron( iii) oxide is reduced to iron by carbon dioxide.  c molten iron is formed at the base of the blast furnace.  d the raw materials are hematite, limestone and coke.     ",
            "10": "10  \u00a9 ucles 2017 0620/11/m/j/17  28 stainless steel is an alloy of iron and other metals. it is strong and does not rust but it costs much  more than normal steel.    what is not made from stainless steel?  a cutlery  b pipes in a chemical factory  c railway lines  d saucepans    29 the diagram shows some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3      30 which gas is colourless and poisonous?  a carbon monoxide  b chlorine  c hydrogen  d nitrogen     ",
            "11": "11  \u00a9 ucles 2017 0620/11/m/j/17 [turn over  31 two experiments involving water are described.    1 water turns purple when potassium manganate( vii) is added to it.  2 adding water to sodium causes the temperature to increase.    which row describes the role of water in 1 and 2?     1 2  a as a chemical reagent as a chemical reagent  b as a chemical reagent as a solvent  c as a solvent as a chemical reagent  d as a solvent as a solvent      32 in which process is carbon dioxide not formed?  a burning of natural gas  b fermentation  c heating lime  d respiration     33 which statement is not correct?  a converting limestone into lime is a thermal decomposition reaction.   b flue gas desulfurisation is a neutralisation reaction.  c in the extraction of iron, calcium carbonate is converted into calcium oxide.   d slaked lime is added to soil as a fertiliser.    34 the structures of three substances are shown.    h c hh o hh chh chh o hh chh chh chh o h     why do these substances all belong to the same homologous series?  a they are all compounds.  b they are all saturated.  c they all contain oxygen.  d they all contain the same functional group.     ",
            "12": "12  \u00a9 ucles 2017 0620/11/m/j/17  35 which fraction of petroleum is not matched to its correct use?     fraction use  a bitumen making roads  b gasoline fuel for cars  c kerosene fuel for ships  d naphtha chemical industry      36 cracking is an important process in the petroleum industry.    the products of cracking include ..1.. and an ..2.. of ..3.. relative molecular mass than the ..4.. that was cracked.    which words complete gaps 1, 2, 3 and 4?     1 2 3 4  a hydrogen alkane greater alkene  b hydrogen alkene smaller alkane  c steam alkane greater alkene  d steam alkene smaller alkane     37 which compound rapidly decolourises aqueous bromine?  a ethane  b ethanoic acid  c ethanol  d ethene     38 there are two methods for producing ethanol.    method 1 catalytic addition of steam to ethene  method 2 fermentation    which statement is not correct?  a method 1 produces carbon dioxide.  b method 1 requires high temperature and pressure.  c method 2 produces carbon dioxide.  d method 2 requires a source of sugar.    ",
            "13": "13  \u00a9 ucles 2017 0620/11/m/j/17  39 which statement about aqueous ethanoic acid is not correct?  a it produces carbon dioxide when it reacts with magnesium carbonate.  b it produces hydrogen when it reacts with magnesium.  c it neutralises magnesium oxide.  d it turns red litmus paper blue.      40 the diagram shows part of the molecule of a polymer.    hh c hh c hh c hh c hh c hh c hh c hh c hh c     which diagram shows the monomer from which this polymer could be manufactured?    abcd hh hh c hc hh c h hh hc hh c o hh h cc hh hh      ",
            "14": "14  \u00a9 ucles 2017 0620/11/m/j/17  blank page",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/11/m/j/17  blank page",
            "16": "16  \u00a9 ucles 2017 0620/11/m/j/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s17_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 14 printed pages and 2 blank pages.  ib17 06_0620_12/4rp  \u00a9 ucles 2017 [turn over     *3788235166* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice (core)  may/june 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/12/m/j/17  1 four statements about the arrangement of particles are given.    1 particles are packed in a regular arrangement.  2 particles are randomly arranged.  3 particles move over each other.  4 particles vibrate about fixed points.    which statements describe the particles in a solid?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      2 a student needs to measure four different volumes of a solution accurately. the volumes are  10  cm3, 25  cm3, 50  cm3 and 60  cm3.    the apparatus available includes a 25  cm3 pipette.    which volumes could be measured using this pipette?  a 10  cm3 and 25  cm3  b 25  cm3 and 50  cm3  c 25  cm3 only  d 50  cm3 and 60  cm3      3 impurities change the melting and boiling points of substances.   sodium chloride is added to a sample of pure water.   how does the addition of sodium chloride affect the melting point and boiling point of the water?     melting point boiling point  a increases increases  b increases decreases  c decreases increases  d decreases decreases    ",
            "3": "3  \u00a9 ucles 2017 0620/12/m/j/17 [turn over  4 the table shows the solubility of four substances, w, x, y and z, in ethanol and in water.    substance solubility in  ethanol solubility in  water  w insoluble insoluble  x insoluble soluble  y soluble insoluble  z soluble soluble    two methods of separation are given.    \u25cf method 1: add the substance to ethanol and then filter  \u25cf method 2: add the substance to water and then filter    which substances can be separated from each other by both method 1 and method 2?  a w and x b x and y c x and z d y and z     5 q and r are elements in the same period of the periodic table.    q has 7 electrons in its outer shell and r has 2 electrons in its outer shell.    which statement about q and r is correct?  a q is a metal and r is a non-metal.  b q and r have different numbers of electron shells.  c r is found to the right of q in the periodic table.  d the proton number of r is less than the proton number of q.      6 which electron arrangement for the outer shell electrons in a covalent compound is correct?    hc la hc lbcd nh hhn h hh       7 which element does not form a stable ion with the same electronic structure as argon?  a aluminium  b chlorine  c phosphorus  d potassium     ",
            "4": "4  \u00a9 ucles 2017 0620/12/m/j/17  8 graphite and diamond are both forms of the element carbon.    which row shows the number of other carbon atoms that each carbon atom is covalently bonded to in graphite and diamond?     graphite diamond  a 3 3  b 3 4  c 4 3  d 4 4     9 when chlorine reacts with hot concentrated aq ueous sodium hydroxide one of the products  formed is sodium chlorate( v).    the formula of sodium chlorate( v) is nac l o3.    what is the relative formula mass of sodium chlorate( v), nac l o3?  a 52.0 b 74.5 c 106.5 d 223.5    10 concentrated aqueous sodium chloride can be electrolysed.    which statement is correct?  a hydrogen gas is formed at the anode, and chlorine gas is formed at the cathode.  b hydrogen gas is formed at the cathode, and chlorine gas is formed at the anode.  c sodium metal is formed at the anode, and chlorine gas is formed at the cathode.  d sodium metal is formed at the cathode, and chlorine gas is formed at the anode.     11 which statement about fuels is correct?  a heat energy can only be produced by burning fuels.  b hydrogen is used as a fuel although it is difficult to store.  c methane is a good fuel because it produces only water when burned.  d uranium is burned in air to produce energy.    ",
            "5": "5  \u00a9 ucles 2017 0620/12/m/j/17 [turn over  12 which statements about exothermic and endothermic reactions are correct?    1 during an exothermic reaction, heat is given out.  2 the temperature of an endothermic reaction goes up because heat is taken in.  3 burning methane in the air is an exothermic reaction.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    13 a gas is produced when calcium carbonate is heated.    which type of change is this?  a chemical  b exothermic  c physical  d separation      14 x is a white solid which dissolves in water to give a blue solution.    what is x?  a anhydrous cobalt( ii) chloride  b anhydrous copper( ii) sulfate  c hydrated cobalt( ii) chloride  d hydrated copper( ii) sulfate     ",
            "6": "6  \u00a9 ucles 2017 0620/12/m/j/17  15 a student was investigating the reaction between marble chips and dilute hydrochloric acid.    bung marble chips 25 cm3 of dilute hydrochloric acidgas syringe     which changes slow down the rate of reaction?     temperature  of acid concentration  of acid surface area  of marble chips  a decrease decrease decrease  b decrease decrease increase  c increase decrease decrease  d increase increase increase     16 the reactions shown may occur in the air during a thunder-storm.    n 2  +  o 2  \u2192  2no  2no  +  o 2  \u2192  2no 2  no  +  o 3  \u2192  no 2  +  o 2    which row shows what happens to the reactant molecules in each of these reactions?     n2 no o 3  a oxidised oxidised oxidised  b oxidised oxidised reduced  c reduced reduced oxidised  d reduced reduced reduced     ",
            "7": "7  \u00a9 ucles 2017 0620/12/m/j/17 [turn over  17 when compound p is added to sodium carbonate, carbon dioxide is produced.    when compound q is added to ammonium chloride, ammonia is produced.    what are p and q?     p q  a a base a base  b a base an acid  c an acid a base  d an acid an acid      18 which oxide is suitable for treating acidic soil?  a calcium oxide  b carbon dioxide  c phosphorus oxide  d silicon( iv) oxide       19 which salt preparation uses a burette and a pipette?  a calcium nitrate from calcium carbonate and nitric acid  b copper( ii) sulfate from copper( ii) hydroxide and sulfuric acid  c potassium chloride from potassium  hydroxide and hydrochloric acid  d zinc chloride from zinc and hydrochloric acid    20 dilute sulfuric acid is added to two separate aqueous solutions, x and y. the observations are  shown.    solution x white precipitate  solution y bubbles of a colourless gas    which row shows the ions present in the solutions?     solution x solution y  a ba2+ co 32\u2013  b ca2+ c l \u2013  c cu2+ co 32\u2013  d fe2+ no 3\u2013     ",
            "8": "8  \u00a9 ucles 2017 0620/12/m/j/17  21 part of the periodic table is shown.    which element is a metal?    a b c d       22 which element is less reactive than the other members of its group in the periodic table?  a astatine  b caesium  c fluorine  d rubidium     23 an element has the following properties.    \u25cf it forms coloured compounds.  \u25cf it acts as a catalyst.  \u25cf it melts at 1539  \u00b0c.    in which part of the periodic table is the element found?  a group i  b group vii  c group viii  d transition elements     24 why are weather balloons sometimes filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen.  c helium is more dense than hydrogen.  d helium is unreactive.    ",
            "9": "9  \u00a9 ucles 2017 0620/12/m/j/17 [turn over  25 element e:    \u2022 forms an alloy  \u2022 has a basic oxide  \u2022 is below hydrogen in the reactivity series.    what is e?  a carbon  b copper  c sulfur  d zinc     26 calcium, copper, iron and magnesium are metals. they can be placed in order of reactivity.    which statement is correct?  a copper reacts with dilute hydrochloric acid to form copper( ii) chloride.  b iron reacts with steam but magnesium does not.  c iron( ii) oxide cannot be reduced by heating strongly with carbon.  d magnesium and calcium both react with hot water.     27 steel is manufactured from the iron produced in a blast furnace.    which statement about the manufacture of iron and steel is not correct?  a in a blast furnace, acidic impurities are removed by adding a basic oxide.  b in a blast furnace, calcium oxide is added to remove basic impurities.  c oxygen is passed into the molten iron from a blast furnace to remove carbon impurities.  d the molten iron from a blast furnace contains traces of other elements such as phosphorus.      28 stainless steel is an alloy of iron and other metals. it is strong and does not rust but it costs much  more than normal steel.    what is not made from stainless steel?  a cutlery  b pipes in a chemical factory  c railway lines  d saucepans    ",
            "10": "10  \u00a9 ucles 2017 0620/12/m/j/17  29 the diagram shows some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3     30 which gas in the air is needed for iron to rust?  a argon  b carbon dioxide  c nitrogen  d oxygen    31 a solid fertiliser contains ammonium sulfate.    a sample of the fertiliser is shaken with water.    to show the presence of ammonium ions in the solution, ..1.. is added and the gas  produced is tested with damp ..2.. litmus paper.    which words complete gaps 1 and 2?     1 2  a aqueous sodium hydroxide blue  b aqueous sodium hydroxide red  c dilute hydrochloric acid blue  d dilute hydrochloric acid red     ",
            "11": "11  \u00a9 ucles 2017 0620/12/m/j/17 [turn over  32 in which process is carbon dioxide not formed?  a burning of natural gas  b fermentation  c heating lime  d respiration      33 statements about methods of manufacture and uses of calcium oxide are shown.    1 it is manufactured by reacting acids with calcium carbonate.  2 it is manufactured by heating calcium carbonate.  3 it is used to desulfurise flue gases.  4 it is used to treat alkaline soil.    which statements are correct?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    34 the structures of three substances are shown.    h c hh o hh chh chh o hh chh chh chh o h     why do these substances all belong to the same homologous series?  a they are all compounds.  b they are all saturated.  c they all contain oxygen.  d they all contain the same functional group.     ",
            "12": "12  \u00a9 ucles 2017 0620/12/m/j/17  35 the industrial fractional distillation of petroleum is shown.    kerosene fractionnaphtha fractiongasoline fractionrefinery gas diesel oil fuel oil fraction petroleum lubricating fraction and bitumeny     which process happens at y?  a burning  b condensation  c cracking  d evaporation     36 two reactions are shown.    1 butane \u2192 ethene  2 ethene \u2192 ethanol    which terms describe reactions 1 and 2?     1 2  a cracking addition  b cracking combustion  c distillation addition  d distillation combustion     ",
            "13": "13  \u00a9 ucles 2017 0620/12/m/j/17  37 ethene is a hydrocarbon.    which row shows the type of bond between the carbon atoms in ethene, and the effect of ethene on aqueous bromine?     type of bond effect of ethene on aqueous bromine  a single bond colour changes from brown to colourless  b single bond colour changes from colourless to brown  c double bond colour changes from brown to colourless  d double bond colour changes from colourless to brown     38 poly(ethene), nylon and terylene  are all polymers.    from which small units are all polymers made?  a alkenes  b monomers  c plastics  d proteins    39 which property is a property of aqueous ethanoic acid?  a it rapidly decolourises aqueous bromine.  b it has a sweet smell.  c it reacts with magnesium ribbon.  d it turns red litmus blue.     40 the diagram shows part of the molecule of a polymer.    hh c hh c hh c hh c hh c hh c hh c hh c hh c     which diagram shows the monomer from which this polymer could be manufactured?    abcd hh hh c hc hh c h hh hc hh c o hh h cc hh hh      ",
            "14": "14  \u00a9 ucles 2017 0620/12/m/j/17  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/12/m/j/17  blank page",
            "16": "16  \u00a9 ucles 2017 0620/12/m/j/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s17_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 13 printed pages and 3 blank pages.  ib17 06_0620_13/3rp  \u00a9 ucles 2017 [turn over     *9908340552 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice (core)  may/june 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/13/m/j/17  1 diagrams r, s and t represent the three states of matter.    t s r    which change occurs during freezing?  a r \u2192 s b s \u2192 t c t \u2192 r d t \u2192 s     2 a student needs to measure 22  cm3 of water at 40  \u00b0c.    which apparatus is required?  a beaker and stopwatch  b beaker and thermometer  c measuring cylinder and stopwatch  d measuring cylinder and thermometer      3 a compound, x, has a melting point of 71  \u00b0c and a boiling point of 375  \u00b0c.    which statement about x is correct?  a it is a liquid at 52  \u00b0c and a gas at 175  \u00b0c.  b it is a liquid at 69  \u00b0c and a gas at 380  \u00b0c.  c it is a liquid at 75  \u00b0c and a gas at 350  \u00b0c.  d it is a liquid at 80  \u00b0c and a gas at 400  \u00b0c.    4 which method is used to obtain a concentrated solution of ethanol from a dilute solution of  ethanol dissolved in water?    a crystallisation  b distillation  c filtration  d paper chromatography     ",
            "3": "3  \u00a9 ucles 2017 0620/13/m/j/17 [turn over  5 which definition of isotopes is correct?  a atoms of the same element that have the same number of electrons and nucleons  b atoms of the same element that have the same number of neutrons and protons  c atoms of the same element that have the same number of protons but a different number of  electrons  d atoms of the same element that have the same number of protons but a different number of  nucleons     6 which statement about a molecule of ammonia, nh 3, is correct?  a each hydrogen atom donates a pair of electrons to a nitrogen atom.  b there are double covalent bonds between the nitrogen atom and the hydrogen atoms.  c there are single covalent bonds between its hydrogen atoms.  d there are three shared pairs of electrons in the molecule.    7 the electronic structures of atoms q and r are shown.    q r     q and r form an ionic compound.    what is the formula of the compound?  a qr 7 b q 2r4 c qr d q 7r      8 which substance is a macromolecule?  a ammonia  b carbon dioxide  c diamond  d water      9 what is the relative formula mass of aluminium oxide, a l 2o3?  a 43 b 70 c 102 d 113     ",
            "4": "4  \u00a9 ucles 2017 0620/13/m/j/17  10 which products are initially obtained at each electrode during the electrolysis of concentrated  aqueous sodium chloride?     cathode anode  a hydrogen chlorine  b hydrogen oxygen  c sodium chlorine  d sodium oxygen     11 heat energy is produced when hydrocarbons burn in air.    which equations represent this statement?    1 c 2h5oh  +  3o 2  \u2192  2co 2  +  3h 2o  2 c 2h4  +  3o 2  \u2192  2co 2  +  2h 2o  3 ch 4  +  2o 2  \u2192  co 2  +  2h 2o    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     12 which statements about exothermic and endothermic reactions are correct?    1 during an exothermic reaction, heat is given out.  2 the temperature of an endothermic reaction goes up because heat is taken in. 3 burning methane in the air is an exothermic reaction.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    13 which changes are physical changes?    1 melting ice to form water  2 burning hydrogen to form water 3 adding sodium to water 4 boiling water to form steam    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    ",
            "5": "5  \u00a9 ucles 2017 0620/13/m/j/17 [turn over  14 which colour change is seen when hydrated cobalt( ii) chloride is heated so that it becomes  anhydrous cobalt( ii) chloride?  a blue to pink  b blue to white  c pink to blue  d white to blue     15 a student was investigating the reaction between marble chips and dilute hydrochloric acid.    bung marble chips 25 cm3 of dilute hydrochloric acidgas syringe     which changes slow down the rate of reaction?     temperature  of acid concentration  of acid surface area  of marble chips  a decrease decrease decrease  b decrease decrease increase  c increase decrease decrease  d increase increase increase     ",
            "6": "6  \u00a9 ucles 2017 0620/13/m/j/17  16 the reactions shown may occur in the air during a thunder-storm.    n2  +  o 2  \u2192  2no  2no  +  o 2  \u2192  2no 2  no  +  o 3  \u2192  no 2  +  o 2    which row shows what happens to the reactant molecules in each of these reactions?     n2 no o 3  a oxidised oxidised oxidised  b oxidised oxidised reduced  c reduced reduced oxidised  d reduced reduced reduced     17 three separate experiments are carried out on a solution of substance x.    1 a gas is produced when x is heated with ammonium chloride.  2 methyl orange is yellow when added to x.  3 there is no reaction between x and sodium carbonate.    which type of substance is x?  a acid  b base  c indicator  d salt     18 farmers spread slaked lime (calcium hydroxide) on  their fields to neutralise soils that are too  acidic for crops to grow well.    which ion in slaked lime neutralises the acid in the soil?  a ca 2+ b h+ c o2\u2013 d oh\u2013      19 which salt preparation uses a burette and a pipette?  a calcium nitrate from calcium carbonate and nitric acid  b copper( ii) sulfate from copper( ii) hydroxide and sulfuric acid  c potassium chloride from potassium  hydroxide and hydrochloric acid  d zinc chloride from zinc and hydrochloric acid    ",
            "7": "7  \u00a9 ucles 2017 0620/13/m/j/17 [turn over  20 aqueous sodium hydroxide reacts with an aqueous solution of compound y to give a green  precipitate.    aqueous ammonia also reacts with an aqueous solution of compound y to give a green  precipitate.    in each case the precipitate is insoluble when an excess of reagent is added.    which ion is present in y?  a chromium( iii)  b copper( ii)  c iron( ii)  d iron( iii)      21 period 3 of the periodic table is shown.    na mg al si p s cl ar    what increases from left to right across period 3?  a density  b melting point  c non-metallic character  d the number of electron shells      22 which element is less reactive than the other members of its group in the periodic table?  a astatine  b caesium  c fluorine  d rubidium     ",
            "8": "8  \u00a9 ucles 2017 0620/13/m/j/17  23 an element has the following properties.    \u25cf it forms coloured compounds.  \u25cf it acts as a catalyst.  \u25cf it melts at 1539  \u00b0c.    in which part of the periodic table is the element found?  a group i  b group vii  c group viii  d transition elements     24 why are weather balloons sometimes filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen.  c helium is more dense than hydrogen.  d helium is unreactive.    25 element e:    \u2022 forms an alloy  \u2022 has a basic oxide  \u2022 is below hydrogen in the reactivity series.    what is e?  a carbon  b copper  c sulfur  d zinc     ",
            "9": "9  \u00a9 ucles 2017 0620/13/m/j/17 [turn over  26 which row shows how the metal reacts?     metal reacts with  dilute acid reacts rapidly with  cold water reacts with  steam  a calcium \u001a \u0016 \u0016  b copper \u0016 \u001a \u001a  c magnesium \u0016 \u001a \u0016  d zinc \u0016 \u001a \u001a      27 which statement about the extraction of iron from hematite is correct?  a air is blown into the blast furnace to oxidise the molten iron.  b carbon dioxide is reduced by coke to carbon monoxide.  c hematite is oxidised by carbon to molten iron.  d the slag produced is denser than molten iron.    28 stainless steel is an alloy of iron and other metals. it is strong and does not rust but it costs much  more than normal steel.    what is not made from stainless steel?  a cutlery  b pipes in a chemical factory  c railway lines  d saucepans      29 the diagram shows some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3    ",
            "10": "10  \u00a9 ucles 2017 0620/13/m/j/17  30 which pollutant gas cannot  be produced by the combustion of fossil fuels (coal, petroleum and  natural gas)?  a carbon monoxide  b methane  c nitrogen dioxide  d sulfur dioxide     31 a farmer wrongly adds two substances to the soil at the same time.    they react together to form a gas which turns damp red litmus blue.    what are the two substances?  a a basic oxide and a potassium salt  b a basic oxide and an ammonium salt  c an acidic oxide and a potassium salt  d an acidic oxide and an ammonium salt    32 in which process is carbon dioxide not formed?  a burning of natural gas  b fermentation  c heating lime  d respiration     33 two equations are shown.    reaction 1 caco 3  \u2192  cao  +  co 2  reaction 2 cao  +  h 2o  \u2192  ca(oh) 2    which terms describe reactions 1 and 2?     reaction 1 reaction 2  a reduction hydration  b reduction hydrolysis  c thermal decomposition hydration  d thermal decomposition hydrolysis     ",
            "11": "11  \u00a9 ucles 2017 0620/13/m/j/17 [turn over  34 the structures of three substances are shown.    h c hh o hh chh chh o hh chh chh chh o h     why do these substances all belong to the same homologous series?  a they are all compounds.  b they are all saturated.  c they all contain oxygen.  d they all contain the same functional group.    35 fuel oil, gasoline, kerosene and naphtha are four fractions obtained from the fractional distillation  of petroleum.    what is the order of the boiling points of these fractions?     highest boiling point \u2192 lowest boiling point  a fuel oil \u2192 kerosene \u2192 gasoline \u2192 naphtha  b fuel oil \u2192 kerosene \u2192 naphtha \u2192 gasoline  c gasoline \u2192 naphtha \u2192 kerosene \u2192 fuel oil  d naphtha \u2192 gasoline \u2192 kerosene \u2192 fuel oil      36 which process produces alkenes from alkanes?  a combustion  b cracking  c fermentation  d polymerisation     ",
            "12": "12  \u00a9 ucles 2017 0620/13/m/j/17  37 poly(ethene) is made from ethene.    ethene is ..1.. hydrocarbon because it contains a carbon to carbon ..2.. bond.    the general name given to small molecules that undergo polymerisation is ..3.. .    which words complete gaps 1, 2 and 3?     1 2 3  a an unsaturated double monomers  b an unsaturated single alkenes  c a saturated double alkenes  d a saturated single monomers      38 which reaction is used to manufacture ethanol?  a reacting ethane with oxygen in the presence of a catalyst  b reacting ethane with steam in the presence of a catalyst  c reacting ethene with steam in the presence of a catalyst  d reacting glucose with steam in the presence of a catalyst      39 which statement about aqueous ethanoic acid is not correct?  a it effervesces with sodium carbonate.  b it neutralises aqueous sodium hydroxide.  c it turns blue litmus from blue to red.  d it turns methyl orange from orange to yellow.      40 the diagram shows part of the molecule of a polymer.    hh c hh c hh c hh c hh c hh c hh c hh c hh c     which diagram shows the monomer from which this polymer could be manufactured?    abcd hh hh c hc hh c h hh hc hh c o hh h cc hh hh    ",
            "13": "13  \u00a9 ucles 2017 0620/13/m/j/17  blank page",
            "14": "14  \u00a9 ucles 2017 0620/13/m/j/17  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/13/m/j/17  blank page",
            "16": "16  \u00a9 ucles 2017 0620/13/m/j/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s17_qp_21.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 16 printed pages.  ib17 o6_0620_21_vi_lil/fp  \u00a9 ucles 2017 [turn over     *8889844006* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/21     paper 2 multiple choice (extended)  may/june 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/21/m/j/17  1 small crystals of purple kmno 4 (mr = 158) and orange k 2cr2o7 (mr = 294) were placed at the  centres of separate petri dishes filled with agar jelly. they were left to stand under the same  physical conditions.    after some time, the colour of each substance had spread out as shown.    dish 1 kmno4dish 2 k2cr2o7    the lengths of the arrows indicate the relative distances travelled by particles of each substance.    which statement is correct?  a diffusion is faster in dish 1 because the mass of the particles is greater.  b diffusion is faster in dish 2 because the mass of the particles is greater.  c diffusion is slower in dish 1 because the mass of the particles is smaller.  d diffusion is slower in dish 2 because the mass of the particles is greater.      2 pure water has a boiling point of 100  \u00b0c and a freezing point of 0  \u00b0c.    what is the boiling point and freezing point of a sample of aqueous sodium chloride?     boiling point  / \u00b0c freezing point  / \u00b0c  a 98 \u20132  b 98 2  c 102 \u20132  d 102 2     ",
            "3": "3  \u00a9 ucles 2017 0620/21/m/j/17 [turn over  3 a chromatogram obtained from the chromatography of four substances is shown.    which substance has an rf value of 0.6?    solvent front baseline a b c d5.5 cm 5.2 cm5.8 cm6.3 cm10.5  cm      4 sodium reacts with chlorine to form sodium chloride.    which statements describe what happens to the sodium atoms in this reaction?    1 sodium atoms form positive ions.  2 sodium atoms form negative ions. 3 sodium atoms gain electrons.  4 sodium atoms lose electrons.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     5 diamond is extremely hard and does not conduct electricity.    which statement explains these properties?  a it has a lattice of positive carbon ions in a \u2018sea of electrons\u2019.  b it has delocalised electrons and each carbon atom forms three covalent bonds with other  carbon atoms.  c it has no delocalised electrons and each carbon atom forms four covalent bonds with other  carbon atoms.  d it has strong ionic bonds between each carbon atom.      6 which statement about metals is not correct?  a metals are malleable because the metal ions can slide over one another.  b metals conduct electricity because electrons can move through the lattice.  c metals consist of a giant lattice of metal ions in a \u2018sea of electrons\u2019.  d metals have high melting points because of the strong attraction between the metal ions.   ",
            "4": "4  \u00a9 ucles 2017 0620/21/m/j/17  7 aluminium reacts with fluorine.    xal (s)  +  y f2(g)  \u2192  zal f3(s)    which values of x, y and z balance the equation?     x y z  a 1 2 1  b 2 3 2  c 3 2 3  d 4 3 4     8 carbon monoxide burns in oxygen to produce carbon dioxide.    2co(g)  +  o 2(g)  \u2192  2co 2(g)    which mass of carbon dioxide is produced from 14  g of carbon monoxide?  a 22  g b 28  g c 44  g d 88  g      9 which statement about electrolysis is correct?  a electrons move through the electrolyte from the cathode to the anode.  b electrons move towards the cathode in the external circuit.  c negative ions move towards the anode in the external circuit.  d positive ions move through the electrolyte towards the anode during electrolysis.     ",
            "5": "5  \u00a9 ucles 2017 0620/21/m/j/17 [turn over  10 the reactivity series for a number of different metals is shown.    most reactive  least reactive  magnesium zinc iron copper silver platinum    the diagram shows different metal strips dipped into an electrolyte.    v metal strip metal strip electrolyte    which pair of metals produces the highest voltage?  a copper and magnesium  b magnesium and platinum  c magnesium and zinc  d silver and platinum    11 some properties of four fuels are shown in the table.    which fuel is a gas at room temperature and makes two products when it burns in a plentiful  supply of air?     fuel formula melting point  /  \u00b0c boiling point  / \u00b0c  a hydrogen h 2 \u2013259 \u2013253  b methane ch 4 \u2013182 \u2013164  c octane c 8h18 \u201357 126  d wax c 31h64 60 400     ",
            "6": "6  \u00a9 ucles 2017 0620/21/m/j/17  12 which statements about exothermic and endothermic reactions are correct?    1 during an exothermic reaction, heat is given out.  2 the temperature of an endothermic reaction goes up because heat is taken in.  3 burning methane in the air is an exothermic reaction.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    13 chlorine reacts with ethane to produce chloroethane and hydrogen chloride.    ch hhh c hc lcl cl cl ++ h ch hhh c hh     the reaction is exothermic.    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013c l +340  c\u2013c +350  c\u2013h +410  cl \u2013c l +240  h\u2013c l +430    what is the energy change for the reaction?  a \u20131420  kj / mol  b \u2013120  kj / mol  c +120  kj / mol  d +1420  kj / mol    ",
            "7": "7  \u00a9 ucles 2017 0620/21/m/j/17 [turn over  14 when sulfur is heated it undergoes a ..1.. change as it melts.    further heating causes the sulfur to undergo a ..2.. change and form sulfur dioxide.    which words complete gaps 1 and 2?     1 2  a chemical chemical  b chemical physical  c physical chemical  d physical physical     15 a student was investigating the reaction between marble chips and dilute hydrochloric acid.    bung marble chips 25 cm3 of dilute hydrochloric acidgas syringe     which changes slow down the rate of reaction?     temperature  of acid concentration  of acid surface area  of marble chips  a decrease decrease decrease  b decrease decrease increase  c increase decrease decrease  d increase increase increase     ",
            "8": "8  \u00a9 ucles 2017 0620/21/m/j/17  16 nitrogen, hydrogen and ammonia gases are placed inside a container. the container is then  sealed. after some time, an equilibrium forms.    n2(g)  +  3h 2(g)    2nh 3(g)    which statement describes the equilibrium in this container?  a the amount of ammonia remains constant from the moment the container is sealed.  b the amounts of ammonia, nitrogen and hydrogen in the container are always equal.  c the rate of formation of ammonia is equal to the rate of decomposition of ammonia.  d the rate of formation of ammonia is faster than the rate of decomposition of ammonia.      17 an example of a redox reaction is shown.    zn  +  cu2+  \u2192  zn2+  +  cu    which statement about the reaction is correct?  a zn is the oxidising agent and it oxidises cu2+.  b zn is the oxidising agent and it reduces cu2+.  c zn is the reducing agent and it oxidises cu2+.  d zn is the reducing agent and it reduces cu2+.     18 zinc oxide is amphoteric.    which row describes the reactions of zinc oxide?     reaction with  hydrochloric acid reaction with  aqueous  sodium hydroxide   a \u0016 \u0016 key  b \u0016 \u001a \u0016= reaction occurs  c \u001a \u0016 \u001a= reaction does not occur  d \u001a \u001a      ",
            "9": "9  \u00a9 ucles 2017 0620/21/m/j/17 [turn over  19 which row shows how the hydrogen ion concentratio n and ph of ethanoic acid compare to those  of hydrochloric acid of the same concentration?     ethanoic acid compared to  hydrochloric acid   hydrogen ion  concentration ph  a higher higher  b higher lower  c lower higher  d lower lower     20 a pure sample of the insoluble salt barium carbonate can be made using the method given.    step 1 dissolve barium chloride in water.  step 2 separately dissolve sodium carbonate in water. step 3 mix the two solutions together. step 4 filter the mixture.  step 5   step 6 dry the residue between two sheets of filter paper.    which instruction is missing from step 5?  a heat the residue to dryness.  b heat the residue to the point of crystallisation.  c place the filtrate in an evaporating basin.  d wash the residue with water.     21 substance x reacts with warm dilute hydroc hloric acid to produce a gas which decolourises  acidified aqueous potassium manganate( vii).    substance x gives a yellow flame in a flame test.    what is x?  a potassium chloride  b potassium sulfite  c sodium chloride  d sodium sulfite     ",
            "10": "10  \u00a9 ucles 2017 0620/21/m/j/17  22 which element is less reactive than the other members of its group in the periodic table?  a astatine  b caesium  c fluorine  d rubidium      23 the elements in  group iv of the periodic table are shown.    carbon  silicon  germanium  tin  lead  flerovium    what does not occur in group iv as it is descended?  a the proton number of the elements increases.  b the elements become more metallic.  c the elements have more electrons in their outer shells.  d the elements have more electron shells.     24 why are weather balloons sometimes filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen.  c helium is more dense than hydrogen.  d helium is unreactive.    ",
            "11": "11  \u00a9 ucles 2017 0620/21/m/j/17 [turn over  25 metal x is added to a colourless aqueous solution of the sulfate of metal y.    a coloured solution is formed and metal y is deposited at the bottom of the beaker.    which row describes elements x and y and their relative reactivity?     type of element relative reactivity  a x is a transition element x is more reactive than y  b x is a transition element y is more reactive than x  c y is a transition element x is more reactive than y  d y is a transition element y is more reactive than x     26 element e:    \u2022 forms an alloy  \u2022 has a basic oxide  \u2022 is below hydrogen in the reactivity series.    what is e?  a carbon  b copper  c sulfur  d zinc    27 zinc metal is extracted from its ore zinc blende in a similar method to that used to extract iron  from hematite.    in which way is zinc extraction different from iron extraction?  a carbon and carbon monoxide are the main reducing agents.  b hot air at the base of the furnace reacts with coke to keep the furnace hot.  c the metal is removed as a vapour at the top of the furnace.  d the metal oxide is added into the top of the furnace.     ",
            "12": "12  \u00a9 ucles 2017 0620/21/m/j/17  28 stainless steel is an alloy of iron and other metals. it is strong and does not rust but it costs much  more than normal steel.    what is not made from stainless steel?  a cutlery  b pipes in a chemical factory  c railway lines  d saucepans    29 the diagram shows some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3     30 oxides of nitrogen are found in polluted air.    which statement about oxides of nitrogen is correct?  a oxides of nitrogen are formed by the reaction of nitrogen with oxygen during the fractional  distillation of liquid air.  b oxides of nitrogen are formed in a car engine by the reaction of petrol with nitrogen from the  air.  c oxides of nitrogen are removed from exhaust gases by reaction with carbon dioxide in a  catalytic converter.  d oxides of nitrogen are removed from exhaus t gases by reduction in a catalytic converter.     ",
            "13": "13  \u00a9 ucles 2017 0620/21/m/j/17 [turn over  31 photosynthesis and respiration are important natural processes.  which statement is correct?  a carbon dioxide is formed by the reaction of glucose with water during photosynthesis.  b carbon dioxide is removed from the air by respiration.  c glucose reacts with water to form oxygen during respiration.  d photosynthesis produces glucose and oxygen.     32 which row gives the conditions for the haber process?     temperature  / \u00b0c pressure  / atm catalyst  a 200 2 v 2o5  b 200 450 fe  c 450 200 fe  d 500 250 v 2o5      33 which statement about sulfuric acid is correct?  a it is made by the haber process.  b it is made in the atmosphere by the action of lightning.  c it reacts with ammonia to produce a fertiliser.  d it reacts with copper metal to produce hydrogen gas.    34 which statement is not correct?  a converting limestone into lime is a thermal decomposition reaction.   b flue gas desulfurisation is a neutralisation reaction.  c in the extraction of iron, calcium carbonate is converted into calcium oxide.   d slaked lime is added to soil as a fertiliser.    ",
            "14": "14  \u00a9 ucles 2017 0620/21/m/j/17  35 which fraction of petroleum is not matched to its correct use?     fraction use  a bitumen making roads  b gasoline fuel for cars  c kerosene fuel for ships  d naphtha chemical industry      36 the diagram shows the structures of two organic molecules.    hch hch ho h hch hch hcoh hch hh     which statement about these molecules is not correct?  a they are both alcohols.  b they both produce carbon dioxide and water when they burn in oxygen.  c they contain different functional groups.  d they have the same general formula.     37 the diagram shows part of the molecule of a polymer.    hh c hh c hh c hh c hh c hh c hh c hh c hh c     which diagram shows the monomer from which this polymer could be manufactured?    abcd hh hh c hc hh c h hh hc hh c o hh h cc hh hh      ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/21/m/j/17  38 ethanol is manufactured by fermentation or by the catalytic addition of steam to ethene.    which statement is correct?  a fermentation uses a higher temperature than the catalytic addition of steam to ethene.  b fermentation uses a non-renewable resource.  c the catalytic addition of steam to ethene produces purer ethanol than fermentation.  d the catalytic addition of steam to ethene uses a biological catalyst.    39 the structure of an ester is shown.    h c h hhch c hhhc oo     which row is correct?     name of ester names of the carboxylic acid and  the alcohol used to form the ester  a methyl propanoate methanoic acid and propanol  b methyl propanoate methanol and propanoic acid  c propyl methanoate methanoic acid and propanol  d propyl methanoate methanol and propanoic acid     40 keratin is a protein that is found in human hair.     keratin is chemically broken down to produce amino acids.    what is the name of this chemical process?  a catalysis  b hydration  c hydrolysis  d polymerisation    ",
            "16": "16  \u00a9 ucles 2017 0620/21/m/j/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s17_qp_22.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib17 06_0620_22/2rp  \u00a9 ucles 2017 [turn over     *6632393932* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2 multiple choice (extended)  may/june 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/22/m/j/17  1 small crystals of purple kmno 4 (mr = 158) and orange k 2cr2o7 (mr = 294) were placed at the  centres of separate petri dishes filled with agar jelly. they were left to stand under the same  physical conditions.    after some time, the colour of each substance had spread out as shown.    dish 1 kmno4dish 2 k2cr2o7    the lengths of the arrows indicate the relative distances travelled by particles of each substance.    which statement is correct?  a diffusion is faster in dish 1 because the mass of the particles is greater.  b diffusion is faster in dish 2 because the mass of the particles is greater.  c diffusion is slower in dish 1 because the mass of the particles is smaller.  d diffusion is slower in dish 2 because the mass of the particles is greater.      2 impurities change the melting and boiling points of substances.   sodium chloride is added to a sample of pure water.   how does the addition of sodium chloride affect the melting point and boiling point of the water?     melting point boiling point  a increases increases  b increases decreases  c decreases increases  d decreases decreases    ",
            "3": "3  \u00a9 ucles 2017 0620/22/m/j/17 [turn over  3 the diagram shows a chromatogram of four substances.    which substance has an rf value of approximately 0.32?    a b c dsolvent front baseline4 cm6 cm12 cm14 cm19 cm 0 cm      4 which element does not form a stable ion with the same electronic structure as argon?  a aluminium  b chlorine  c phosphorus  d potassium     5 graphite and diamond are both forms of the element carbon.    which row shows the number of other carbon atoms that each carbon atom is covalently bonded  to in graphite and diamond?     graphite diamond  a 3 3  b 3 4  c 4 3  d 4 4    ",
            "4": "4  \u00a9 ucles 2017 0620/22/m/j/17  6 which statement describes metallic bonding?  a the attraction between a lattice of negative ions and delocalised protons.  b the attraction between a lattice of positive ions and delocalised electrons.  c the attraction between delocalised protons and electrons.  d the attraction between oppositely charged ions.      7 which equations are balanced?    1 fe 2o3  +  3co  \u2192  2fe  +  3co 2  2 znco 3  +  2hc l  \u2192  znc l 2  +  co 2  +  2h 2o  3 mg(no 3)2  +  naoh  \u2192  mg(oh) 2  +  2nano 3  4 caco 3  +  h 2so 4  \u2192  caso 4  +  h 2o  +  co 2    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    8 calcium carbide, cac 2, reacts with water to form ethyne, c 2h2, and calcium hydroxide.    the equation for the reaction is shown.    cac 2(s)  +  2h 2o(l)  \u2192  c2h2(g)  +  ca(oh) 2(s)    which volume of ethyne is produced when 6  g of water react completely with calcium carbide?  a 4 dm3 b 8 dm3 c 36  dm3 d 72  dm3      9 which statement about electrolysis is correct?  a electrons move through the electrolyte from the cathode to the anode.  b electrons move towards the cathode in the external circuit.  c negative ions move towards the anode in the external circuit.  d positive ions move through the electrolyte towards the anode during electrolysis.     ",
            "5": "5  \u00a9 ucles 2017 0620/22/m/j/17 [turn over  10 the reactivity series for a number of different metals is shown.    most reactive  least reactive  magnesium zinc iron copper silver platinum    the diagram shows different metal strips dipped into an electrolyte.    v metal strip metal strip electrolyte    which pair of metals produces the highest voltage?  a copper and magnesium  b magnesium and platinum  c magnesium and zinc  d silver and platinum     11 which statement about fuels is correct?  a heat energy can only be produced by burning fuels.  b hydrogen is used as a fuel although it is difficult to store.  c methane is a good fuel because it produces only water when burned.  d uranium is burned in air to produce energy.    12 which statements about exothermic and endothermic reactions are correct?    1 during an exothermic reaction, heat is given out.  2 the temperature of an endothermic reaction goes up because heat is taken in. 3 burning methane in the air is an exothermic reaction.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "6": "6  \u00a9 ucles 2017 0620/22/m/j/17  13 the equation for the reaction between hydrogen and chlorine is shown.    h2(g)  +  c l 2(g)  \u2192  2hc l (g)    the reaction is exothermic.    the bond energies are shown in the table.    bond bond energy  in kj  / mol  cl \u2013c l +240  h\u2013c l +430  h\u2013h +436    what is the energy change for the reaction?  a \u20131536  kj / mol  b \u2013184  kj / mol  c +184  kj / mol  d +246  kj / mol      14 a gas is produced when calcium carbonate is heated.    which type of change is this?  a chemical  b exothermic  c physical  d separation    ",
            "7": "7  \u00a9 ucles 2017 0620/22/m/j/17 [turn over  15 a student was investigating the reaction between marble chips and dilute hydrochloric acid.    bung marble chips 25 cm3 of dilute hydrochloric acidgas syringe     which changes slow down the rate of reaction?     temperature  of acid concentration  of acid surface area  of marble chips  a decrease decrease decrease  b decrease decrease increase  c increase decrease decrease  d increase increase increase     16 the reaction used to manufacture ammonia from nitrogen and hydrogen is reversible.    an equilibrium can be established between ammonia, nitrogen and hydrogen.    which statement describes the equilibrium?  a both the forward reaction and the backward reaction have the same rate.  b the rate of the backward reaction is greater than the rate of the forward reaction.  c the rate of the forward reaction is greater than the rate of the backward reaction.  d the forward and backward reactions have both stopped.      17 an example of a redox reaction is shown.    zn  +  cu 2+  \u2192  zn2+  +  cu    which statement about the reaction is correct?  a zn is the oxidising agent and it oxidises cu2+.  b zn is the oxidising agent and it reduces cu2+.  c zn is the reducing agent and it oxidises cu2+.  d zn is the reducing agent and it reduces cu2+.     ",
            "8": "8  \u00a9 ucles 2017 0620/22/m/j/17  18 which type of oxide is aluminium oxide?  a acidic  b amphoteric  c basic  d neutral      19 which statements about a weak acid, such as ethanoic acid, are correct?    1 it reacts with a carbonate.  2 it does not neutralise aqueous sodium hydroxide solution.  3 it turns red litmus blue.  4 it is only partially ionised in aqueous solution.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     20 silver chloride is a white solid which is insoluble in water.    which statement describes how a sample of pure silver chloride can be made?  a add aqueous silver nitrate to aqueous sodium chloride and then filter.  b add aqueous silver nitrate to dilute hydrochloric acid, evaporate and then crystallise.  c add silver carbonate to dilute hydrochloric acid, evaporate and then crystallise.  d add silver to dilute hydrochloric acid, filter and then wash the residue.     21 dilute sulfuric acid is added to two separate aqueous solutions, x and y. the observations are  shown.    solution x white precipitate  solution y bubbles of a colourless gas    which row shows the ions present in the solutions?     solution x solution y  a ba2+ co 32\u2013  b ca2+ c l \u2013  c cu2+ co 32\u2013  d fe2+ no 3\u2013     ",
            "9": "9  \u00a9 ucles 2017 0620/22/m/j/17 [turn over  22 which element is less reactive than the other members of its group in the periodic table?  a astatine  b caesium  c fluorine  d rubidium      23 the elements oxygen and sulfur are in the same group of the periodic table.    which statement about oxygen and sulfur is not correct?  a they are non-metals.  b they have giant covalent structures.  c they have six electrons in their outer shells.  d they react together to form an acidic oxide.     24 why are weather balloons sometimes filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen.  c helium is more dense than hydrogen.  d helium is unreactive.     25 which process is involved in the extraction of zinc from zinc blende?  a cryolite is added to lower the melting point of zinc blende.  b molten zinc blende is electrolysed.  c zinc blende is heated with carbon.  d zinc blende is roasted in air.     ",
            "10": "10  \u00a9 ucles 2017 0620/22/m/j/17  26 element e:    \u2022 forms an alloy  \u2022 has a basic oxide  \u2022 is below hydrogen in the reactivity series.    what is e?  a carbon  b copper  c sulfur  d zinc     27 a list of metals is shown.    aluminium  copper  iron  magnesium  silver  zinc    which metal will displace all of the other metals from aqueous solutions of their salts?  a aluminium  b iron  c magnesium  d zinc    28 stainless steel is an alloy of iron and other metals. it is strong and does not rust but it costs much  more than normal steel.    what is not made from stainless steel?  a cutlery  b pipes in a chemical factory  c railway lines  d saucepans    ",
            "11": "11  \u00a9 ucles 2017 0620/22/m/j/17 [turn over  29 the diagram shows some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3    30 the carbon cycle includes the processes combustion, photosynthesis and respiration.    which row shows how each process changes the amount of carbon dioxide in the atmosphere?     combustion photosynthesis respiration  a decreases decreases increases  b decreases increases decreases  c increases decreases increases  d increases increases decreases      31 which statement about the conditions used in the haber process is not correct?  a a high temperature is used because the forward reaction is exothermic.  b a high pressure is used because there are fewer moles of gas in the products than in the  reactants.  c an iron catalyst is used to increase the rate of the forward reaction.  d the unreacted hydrogen and nitrogen are recycled to increase the amount of ammonia  produced.     32 which chemical reaction decreases pollution in the air?  a s  +  o 2  \u2192  so 2  b n 2  +  o 2  \u2192  2no  c 2ch 4  +  3o 2  \u2192  2co  +  4h 2o  d 2no  +  2co  \u2192  2co 2  +  n 2     ",
            "12": "12  \u00a9 ucles 2017 0620/22/m/j/17  33 which statement about sulfuric acid is correct?  a it is made by the haber process.  b it is made in the atmosphere by the action of lightning.  c it reacts with ammonia to produce a fertiliser.  d it reacts with copper metal to produce hydrogen gas.      34 statements about methods of manufacture and uses of calcium oxide are shown.    1 it is manufactured by reacting acids with calcium carbonate.  2 it is manufactured by heating calcium carbonate.  3 it is used to desulfurise flue gases.  4 it is used to treat alkaline soil.    which statements are correct?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    35 the industrial fractional distillation of petroleum is shown.    kerosene fractionnaphtha fractiongasoline fractionrefinery gas diesel oil fuel oil fraction petroleum lubricating fraction and bitumeny     which process happens at y?  a burning  b condensation  c cracking  d evaporation    ",
            "13": "13  \u00a9 ucles 2017 0620/22/m/j/17 [turn over  36 which statement about homologous series is not correct?  a alkenes have the same general formula, c nh2n+2.  b each member of the homologous series of alkanes differs from the next by ch 2.  c the members of a homologous series all have similar chemical properties.  d the members of a homologous series all have the same functional group.      37 the diagram shows part of the molecule of a polymer.    hh c hh c hh c hh c hh c hh c hh c hh c hh c     which diagram shows the monomer from which this polymer could be manufactured?    abcd hh hh c hc hh c h hh hc hh c o hh h cc hh hh      38 ethanol is manufactured by fermentation or by the catalytic addition of steam to ethene.    what is an advantage of ethanol manufacture by ferm entation instead of by the catalytic addition  of steam to ethene?  a ethanol manufactured by fermentation is purified by distillation.  b ethanol manufacture by fermentation produces purer ethanol.  c ethanol manufacture by fermentation uses large areas of land.  d ethanol manufacture by fermentation uses renewable resources.     39 the formula of an ester is ch 3ch 2ch 2cooch 2ch 2ch 3.    which acid and alcohol react together to make the ester?     acid alcohol  a butanoic acid butanol  b butanoic acid propanol  c propanoic acid butanol  d propanoic acid propanol     ",
            "14": "14  \u00a9 ucles 2017 0620/22/m/j/17  40 polyesters and polyamides are types of synthetic polymer.    which statements are correct?    1 they are made by addition polymerisation.  2 they are made by condensation polymerisation. 3 the monomers from which they are made are unsaturated hydrocarbons. 4 the monomers from which they are made contain reactive functional groups at their  ends.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/22/m/j/17  blank page",
            "16": "16  \u00a9 ucles 2017 0620/22/m/j/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s17_qp_23.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib17 06_0620_23/3rp  \u00a9 ucles 2017 [turn over     *0971587250* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/23     paper 2 multiple choice (extended)  may/june 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.    there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.    read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/23/m/j/17  1 small crystals of purple kmno 4 (mr = 158) and orange k 2cr2o7 (mr = 294) were placed at the  centres of separate petri dishes filled with agar jelly. they were left to stand under the same physical conditions.    after some time, the colour of each substance had spread out as shown.    dish 1 kmno4dish 2 k2cr2o7    the lengths of the arrows indicate the relative distances travelled by particles of each substance.    which statement is correct?  a diffusion is faster in dish 1 because the mass of the particles is greater.  b diffusion is faster in dish 2 because the mass of the particles is greater.  c diffusion is slower in dish 1 because the mass of the particles is smaller.  d diffusion is slower in dish 2 because the mass of the particles is greater.     2 a compound, x, has a melting point of 71  \u00b0c and a boiling point of 375  \u00b0c.    which statement about x is correct?  a it is a liquid at 52  \u00b0c and a gas at 175  \u00b0c.  b it is a liquid at 69  \u00b0c and a gas at 380  \u00b0c.  c it is a liquid at 75  \u00b0c and a gas at 350  \u00b0c.  d it is a liquid at 80  \u00b0c and a gas at 400  \u00b0c.     ",
            "3": "3  \u00a9 ucles 2017 0620/23/m/j/17 [turn over  3 a student used chromatography to analyse a green food colouring.    the chromatogram obtained is shown.    solvent front baselineblue spot yellow spot     the table lists some yellow food dyes and their rf values.    which yellow food dye does the green food colouring contain?     yellow food dye rf value  a quinolene yellow 0.48  b sunset yellow 0.32  c tartrazine 0.69  d yellow 2g 0.82     4 the electronic structures of atoms q and r are shown.    q r     q and r form an ionic compound.    what is the formula of the compound?  a qr 7 b q 2r4 c qr d q 7r     ",
            "4": "4  \u00a9 ucles 2017 0620/23/m/j/17  5 which substance is a macromolecule?  a ammonia  b carbon dioxide  c diamond  d water      6 the diagram shows metallic bonding.    x y     which labels are correct?     x y  a atomic nucleus outer electron  b metal atom mobile electron  c metal ion mobile electron  d positive ion negative ion      7 aqueous iron( iii) sulfate and aqueous sodium hydroxide react to give a precipitate of  iron(iii) hydroxide and a solution of sodium sulfate.    what is the balanced equation for this reaction?  a fe 2(so 4)3(aq)  +  2naoh(aq)  \u2192  fe(oh) 3(s)  +  na 2so 4(aq)  b fe 2(so 4)3(aq)  +  3naoh(aq)  \u2192  fe(oh) 3(s)  +  3na 2so 4(aq)  c fe 2(so 4)3(aq)  +  6naoh(aq)  \u2192  2fe(oh) 3(s)  +  3na 2so 4(aq)  d 2fe 2(so 4)3(aq)  +  6naoh(aq)  \u2192  4fe(oh) 3(s)  +  6na 2so 4(aq)     8 the equation for the reaction between sodium carbonate and dilute hydrochloric acid is shown.    na 2co 3  +  2hc l  \u2192  2nac l  +  h 2o  +  co 2    what is the maximum volume of carbon dioxide produced when 26.5  g of sodium carbonate react  with dilute hydrochloric acid?  a 6 dm3 b 12  dm3 c 18  dm3 d 24  dm3     ",
            "5": "5  \u00a9 ucles 2017 0620/23/m/j/17 [turn over  9 which statement about electrolysis is correct?  a electrons move through the electrolyte from the cathode to the anode.  b electrons move towards the cathode in the external circuit.  c negative ions move towards the anode in the external circuit.  d positive ions move through the electrolyte towards the anode during electrolysis.      10 the reactivity series for a number of different metals is shown.    most reactive  least reactive  magnesium zinc iron copper silver platinum    the diagram shows different metal strips dipped into an electrolyte.    v metal strip metal strip electrolyte    which pair of metals produces the highest voltage?  a copper and magnesium  b magnesium and platinum  c magnesium and zinc  d silver and platinum    11 heat energy is produced when hydrocarbons burn in air.    which equations represent this statement?    1 c 2h5oh  +  3o 2  \u2192  2co 2  +  3h 2o  2 c 2h4  +  3o 2  \u2192  2co 2  +  2h 2o  3 ch 4  +  2o 2  \u2192  co 2  +  2h 2o    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "6": "6  \u00a9 ucles 2017 0620/23/m/j/17  12 which statements about exothermic and endothermic reactions are correct?    1 during an exothermic reaction, heat is given out.  2 the temperature of an endothermic reaction goes up because heat is taken in.  3 burning methane in the air is an exothermic reaction.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    13 hydrogen and chlorine react to form hydrogen chloride.     the reaction is exothermic.   h 2(g)  +  c l 2(g)  \u2192  2hc l (g)    the overall energy change for this reaction is \u2013184  kj / mol.    the table gives some of the bond energies involved.    bond bond energy in  kj / mol  h\u2013c l +430  h\u2013h +436    what is the energy of the c l\u2013cl bond?  a \u2013240  kj / mol  b \u2013190  kj / mol  c +190  kj / mol  d +240  kj / mol    14 which changes are physical changes?    1 melting ice to form water  2 burning hydrogen to form water 3 adding sodium to water 4 boiling water to form steam    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    ",
            "7": "7  \u00a9 ucles 2017 0620/23/m/j/17 [turn over  15 a student was investigating the reaction between marble chips and dilute hydrochloric acid.    bung marble chips 25 cm3 of dilute hydrochloric acidgas syringe     which changes slow down the rate of reaction?     temperature  of acid concentration  of acid surface area  of marble chips  a decrease decrease decrease  b decrease decrease increase  c increase decrease decrease  d increase increase increase     16 hydrogen is produced when methane reacts with steam.    the equation for the reaction is shown.    ch 4(g)  +  h 2o(g)    co(g)  +  3h 2(g)    the forward reaction is endothermic.    which conditions produce the highest yield of hydrogen?     pressure temperature  a high high  b high low  c low high  d low low     ",
            "8": "8  \u00a9 ucles 2017 0620/23/m/j/17  17 an example of a redox reaction is shown.    zn  +  cu2+  \u2192  zn2+  +  cu    which statement about the reaction is correct?  a zn is the oxidising agent and it oxidises cu2+.  b zn is the oxidising agent and it reduces cu2+.  c zn is the reducing agent and it oxidises cu2+.  d zn is the reducing agent and it reduces cu2+.      18 which oxide is amphoteric?  a al 2o3 b cao  c na2o d so 2      19 chloric( i) acid, hc l o, is formed when chlorine dissolves in water. it is a weak acid.    what is meant by the term  weak acid  ?  a it contains fewer hydrogen atoms than a strong acid.  b it is easily neutralised by a strong alkali.  c it is less concentrated than a strong acid.  d it is only partially ionised in solution.     20 silver nitrate reacts with sodium chloride to produce silver chloride and sodium nitrate. the  equation for the reaction is shown.    agno 3(aq)  +  nac l (aq)  \u2192  agc l (s)  +  nano 3(aq)    how is silver chloride separated from the reaction mixture?  a crystallisation  b distillation  c evaporation  d filtration     ",
            "9": "9  \u00a9 ucles 2017 0620/23/m/j/17 [turn over  21 aqueous sodium hydroxide reacts with an aqueous solution of compound y to give a green  precipitate.    aqueous ammonia also reacts with an aqueous solution of compound y to give a green  precipitate.    in each case the precipitate is insoluble when an excess of reagent is added.    which ion is present in y?  a chromium( iii)  b copper( ii)  c iron( ii)  d iron( iii)     22 which element is less reactive than the other members of its group in the periodic table?  a astatine  b caesium  c fluorine  d rubidium     23 ununseptium (atomic number 117) is a man-made element that is below astatine in group vii of  the periodic table.    what is the expected state of ununseptium at room temperature?  a a diatomic gas  b a liquid  c a monatomic gas  d a solid     24 why are weather balloons sometimes filled with helium rather than hydrogen?  a helium is found in air.  b helium is less dense than hydrogen.  c helium is more dense than hydrogen.  d helium is unreactive.     ",
            "10": "10  \u00a9 ucles 2017 0620/23/m/j/17  25 which equation from the zinc extraction proce ss shows the metal being produced by reduction?  a zno  +  c  \u2192  zn  +  co  b 2zns  +  3o 2  \u2192  2zno  +  2so 2  c zn(g)  \u2192  zn(l)  d zn(l)  \u2192  zn(s)     26 element e:    \u2022 forms an alloy  \u2022 has a basic oxide  \u2022 is below hydrogen in the reactivity series.    what is e?  a carbon  b copper  c sulfur  d zinc    27 the section of the reactivity series shown in cludes a newly discovered element, symbol x.    the only oxide of x has the formula xo.    ca  mg  fe  x  h  cu    which equation shows a reaction which occurs?  a cu(s)  +  x 2+(aq)  \u2192  cu2+(aq)  +  x(s)  b 2x(s)  +  cu2+(aq)  \u2192  2x+(aq)  +  cu(s)  c x(s)  +  fe 2o3(s)  \u2192  2fe(s)  +  3xo(s)  d x(s)  +  2hc l (aq)  \u2192  xc l 2(aq)  +  h 2(g)     ",
            "11": "11  \u00a9 ucles 2017 0620/23/m/j/17 [turn over  28 stainless steel is an alloy of iron and other metals. it is strong and does not rust but it costs much  more than normal steel.    what is not made from stainless steel?  a cutlery  b pipes in a chemical factory  c railway lines  d saucepans    29 the diagram shows some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3     30 the carbon cycle describes how carbon dioxide gas is added to or removed from the  atmosphere.    which row describes the movement of carbon dioxide during each process?     photosynthesis combustion respiration  a   added to the  atmosphere added to the  atmosphere removed from  the atmosphere  b   added to the  atmosphere removed from  the atmosphere added to the  atmosphere  c   removed from  the atmosphere added to the  atmosphere added to the  atmosphere  d   removed from  the atmosphere added to the  atmosphere removed from  the atmosphere     ",
            "12": "12  \u00a9 ucles 2017 0620/23/m/j/17  31 which row gives the catalyst for the haber process and the sources of the raw materials?     catalyst source of  hydrogen source of  nitrogen  a iron electrolysis fertiliser  b iron methane air  c vanadium pentoxide methane air  d vanadium pentoxide methane fertiliser     32 petrol burns in a car engine to produce waste gases which leave through the car exhaust.     one of these waste gases is an oxide of nitrogen.    which statement describes how this oxide of nitrogen is formed?  a carbon dioxide reacts with nitrogen in the catalytic converter.  b nitrogen reacts with oxygen in the car engine.  c nitrogen reacts with oxygen in the catalytic converter.  d petrol combines with nitrogen in the car engine.    33 which statement about sulfuric acid is correct?  a it is made by the haber process.  b it is made in the atmosphere by the action of lightning.  c it reacts with ammonia to produce a fertiliser.  d it reacts with copper metal to produce hydrogen gas.     34 two equations are shown.    reaction 1 caco 3  \u2192  cao  +  co 2  reaction 2 cao  +  h 2o  \u2192  ca(oh) 2    which terms describe reactions 1 and 2?     reaction 1 reaction 2  a reduction hydration  b reduction hydrolysis  c thermal decomposition hydration  d thermal decomposition hydrolysis     ",
            "13": "13  \u00a9 ucles 2017 0620/23/m/j/17 [turn over  35 fuel oil, gasoline, kerosene and naphtha are four fractions obtained from the fractional distillation  of petroleum.    what is the order of the boiling points of these fractions?     highest boiling point \u2192 lowest boiling point  a fuel oil \u2192 kerosene \u2192 gasoline \u2192 naphtha  b fuel oil \u2192 kerosene \u2192 naphtha \u2192 gasoline  c gasoline \u2192 naphtha \u2192 kerosene \u2192 fuel oil  d naphtha \u2192 gasoline \u2192 kerosene \u2192 fuel oil     36 butane and methylpropane are isomers with molecular formula c 4h10.    which statements are correct?    1 they have similar chemical properties.  2 they have the same general formula. 3 they have the same structural formula.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    37 the diagram shows part of the molecule of a polymer.    hh c hh c hh c hh c hh c hh c hh c hh c hh c     which diagram shows the monomer from which this polymer could be manufactured?    abcd hh hh c hc hh c h hh hc hh c o hh h cc hh hh      ",
            "14": "14  \u00a9 ucles 2017 0620/23/m/j/17  38 ethanol can be produced by fermentation or by the catalytic addition of steam to ethene.    which row shows an advantage and a disadvantage for each process?     fermentation catalytic addition  of steam to ethene  advantage disadvantage advantage disadvantage  a   batch  process slow   reaction continuous  process fast  reaction  b   fast  reaction continuous  process pure ethanol  formed renewable  raw material  c   renewable  raw material batch   process pure ethanol  formed slow  reaction  d   renewable  raw material impure ethanol  formed fast   reaction finite raw  material    39 the structure of an ester is shown.    h c h hh cco o hh c hh ch h    which alcohol and carboxylic acid produce this ester?     alcohol carboxylic acid  a ethanol ethanoic acid  b ethanol propanoic acid  c propanol ethanoic acid  d propanol propanoic acid     40 how can the amino acids in a protein be separated and identified?  a add a locating agent to the protein.  b hydrolyse the protein and then use chromatography.  c polymerise the protein and then add a locating agent.  d use chromatography on a solution of the protein.    ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/23/m/j/17  blank page",
            "16": "16  \u00a9 ucles 2017 0620/23/m/j/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s17_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry   0620/31   paper 3 theory (core) may/june 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 16 printed pages. [turn overib17 06_0620_31/fp \u00a9 ucles 2017 \uf02a\uf032\uf033\uf038\uf034\uf034\uf034\uf034\uf030\uf030\uf038\uf02a the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/31/m/j/17 \u00a9 ucles 20171 (a)   the electronic structures of \ufb01 ve atoms, a, b, c, d and e, are shown. a b c d e   answer the following questions about these atoms.   each atom may be used once, more than once or not at all.   which atom, a, b, c, d or e,  (i)  has a complete outer shell of electrons,  ..  [1]  (ii)  has a proton number of 15,  ..  [1]  (iii)  has 4 shells containing electrons,  ..  [1]  (iv)  is a \ufb02 uorine atom,  ..  [1]  (v)  is an atom of a metallic element?  ..  [1]  (b)  complete the table to show the number of electrons, neutrons and protons in the chlorine atom  and bromide ion shown. number of electrons number of neutrons number of protons 35cl17 17 79br \u2013 35 44 [3] [total: 8]",
            "3": "3 0620/31/m/j/17 \u00a9 ucles 2017 [turn over2 (a)   the table shows the ions present in a 1000 cm3 sample of polluted river water. ion present formula of ionmass present in mg / 1000 cm3 calcium ca2+2.0 chloride c l \u20131.3 hydrogencarbonate hco3\u20132.0 magnesium mg2+1.0 potassium k+4.0 silicate sio32\u201312.0 sodium na+11.0 so32\u20133.0   answer these questions using the information from the table.  (i)  which positive ion is present in the highest concentration?   . ..  [1]  (ii)  state the name of the ion so32\u2013.   . ..  [1]  (iii)  calculate the mass of silicate ions present in 250 cm3 of this sample. mass of silicate ions = .. mg  [1]  (iv)  calculate the mass of solid formed when all the water is evaporated from the 1000 cm3  sample. mass of solid formed = .. mg  [1]  (v)  name the compound containing ca2+ ions and hco3\u2013 ions.   . ..  [1]",
            "4": "4 0620/31/m/j/17 \u00a9 ucles 2017 (b)  describe a test for sodium ions.  test   .  result  ..  [2]  (c)  the formulae of some chlorides are given.   aluminium chloride, a l cl 3   calcium chloride, cac l 2   sodium chloride, nac l   deduce the formula for magnesium chloride.   ... ...  [1]  (d)  molten calcium chloride can be electrolysed using inert electrodes.   predict the products of this electrolysis at  the negative electrode (cathode),  ... ...  the positive electrode (anode).  . . [2] [total: 10]",
            "5": "5 0620/31/m/j/17 \u00a9 ucles 2017 [turn over3  the diagram shows part of the structures of three substances, x, y and z, at room temperature and  pressure. oco ocoo c ooco o c ona+cl \u2013na+cl \u2013 na+cl \u2013na+cl \u2013cl \u2013na+cl \u2013na+ xyz  (a)  describe substances x, y and z in terms of  \u25cf  their bonding,  \u25cf  the arrangement of their particles,  \u25cf  the motion of their particles.   ... .   ... .   ... .   ... .   ... .   ... .   ... .   ... .   ... ...  [5]",
            "6": "6 0620/31/m/j/17 \u00a9 ucles 2017 (b)  a closed gas syringe contains substance x. x end blocked gas syringe   describe what happens to the volume of substance x in the syringe when the pressure is  increased. the temperature remains constant. explain your answer in terms of particles.   ... .   ... ...  [2]  (c)  substance z is diamond. diamond is used in jewellery.   give one other use of diamond.   ... ...  [1]  (d)  substance y undergoes physical and chemical changes.  which two of the following are physical changes? explain your answer.  a  substance y dissolves easily in water.  b  an aqueous solution of substance y gives a white precipitate with acidified aqueous  silver nitrate.  c  substance y melts at 801 \uf0b0c.  d  substance y reacts with concentrated sulfuric acid.   ... .   ... .   ... ...  [3] [total: 11]",
            "7": "7 0620/31/m/j/17 \u00a9 ucles 2017 [turn over4  chlorine is an element in group vii of the periodic table.  (a)  chlorine is a diatomic molecule.   explain what is meant by the term diatomic .   ... ...  [1]  (b)  aqueous chlorine reacts with aqueous potassium bromide. cl 2  +  2kbr    br2  +  2kc l  (i)  how does this equation show that chlorine is more reactive than bromine?   . ..  [1]  (ii)  aqueous potassium bromide and aqueous potassium chloride are both colourless.   predict the colour change when aqueous chlorine reacts with aqueous potassium bromide.   . ..  [1]  (iii)  complete the chemical equation for the reaction of aqueous bromine with aqueous  potassium iodide. br2  +  2k i    ...  +  ... [2]  (c)  describe a test for iodide ions.  test   .  result  ..  [2]",
            "8": "8 0620/31/m/j/17 \u00a9 ucles 2017 (d)  chlorine is used to make the polymer pvc.  (i)  give one other use of chlorine.   . ..  [1]  (ii)  the monomer used to make pvc is made by the thermal decomposition of dichloroethane. ch2cl \u2013ch2cl    ch2=chc l  +  hc l   explain what is meant by the term thermal decomposition .   .    . ..  [2]  (iii)   pvc is a non-biodegradable plastic.   describe two pollution problems caused by non-biodegradable plastics.  1  ... ...  2  ... ... [2] [total: 12]",
            "9": "9 0620/31/m/j/17 \u00a9 ucles 2017 [turn over5  citronellol is found in rose oil.   the structure of citronellol is shown. ch2ch2 ch2 ch2 ccc h hch3 ch3 ch3oh  (a)  on the structure shown draw a circle around the alcohol functional group. [1]  (b)  how many hydrogen atoms are there in one molecule of citronellol?   ... ...  [1]  (c)  what feature of the citronellol structure shows that it is unsaturated?   ... ...  [1]",
            "10": "10 0620/31/m/j/17 \u00a9 ucles 2017 (d)  the table shows the properties of some alkanes. alkanenumber of carbon atoms in one moleculemelting point in \uf0b0cboiling point in \uf0b0cdensity of liquid alkane in g / cm3 methane 1 \u2013182 \u2013162 0.466 ethane 2 \u2013183 \u201388 0.572 propane 3 \u2013188 0.585 butane 4 0 0.601 pentane 5 \u2013130 36 0.626  (i)  describe how the density of the liquid alkanes varies with the number of carbon atoms in  one molecule.   . ..  [1]  (ii)  predict the boiling point of propane.   . ..  [1]  (iii)  why would it be dif \ufb01 cult to predict the melting point of butane from the information in the  table?   . ..  [1]  (iv)  what is the state of pentane at 30 \uf0b0c? explain your answer.   .    . ..  [2]  (v)  alkanes are hydrocarbons.   what is the meaning of the term hydrocarbon ?   .    . ..  [2]  (vi)  draw the structure of ethane. show all of the atoms and all of the bonds. [1]  (vii)  complete the chemical equation for the combustion of propane. c3h8  +  ...o2    ...co2  +  4h2o [2] [total: 13]",
            "11": "11 0620/31/m/j/17 \u00a9 ucles 2017 [turn over6 (a)   the table shows the properties of some metals. metaldensity in g / cm3melting point in \uf0b0crelative strengthrelative electrical conductivitycost aluminium 2.7 660 7.0 4.0 expensive iron 7.9 1535 21.0 1.1 cheap lead 11.3 328 1.5 0.5 expensive silver 10.5 962 2.0 6.7 very expensive tungsten 19.4 3420 12.0 2.0 expensive   use the information in the table to answer the questions.  (i)  which metal would be most useful for making overhead power cables?   give two reasons for your answer.  metal  reason 1   ..  reason 2   .. [2]  (ii)  why is iron and not tungsten used to reinforce concrete?   . ..  [1]  (iii)  the front part of a space rocket is called a nose cone. the nose cone gets very hot as the  space rocket moves through the air.   which metal is best to make a space rocket nose cone? explain your answer.   . ..  [1]  (b)  tungsten is a transition element.   state two physical properties of transition elements which are not shown by group i elements.  1  ... ..  2  ... .. [2]",
            "12": "12 0620/31/m/j/17 \u00a9 ucles 2017 (c)  when extremely hot tungsten reacts with oxygen, tungsten( vi) oxide is formed.   balance the chemical equation for this reaction. ..w  +  ..o2    2wo3 [2]  (d)  some information about the reaction of four metals with oxygen is given.  cobalt:  reacts slowly at high temperatures  iron: thin wire burns when heated strongly magnesium:  burns when heated  tungsten:  reacts very slowly at extremely high temperatures   list these metals in order of their reactivity. put the least reactive metal \ufb01 rst. least  reactive most  reactive [2]  (e)  the table compares the time taken for reaction of an alloy with ethanoic acid, nitric acid and  phosphoric acid, each at three different concentrations. the time taken for the alloy to decrease in mass by 1.0 g was measured. all other conditions were kept the same. acidtime taken for reaction / hours concentration of acid 0.04 mol / dm3concentration of acid 0.02 mol / dm3concentration of acid 0.01 mol / dm3 ethanoic acid 92 190 410 nitric acid 2 6 18 phosphoric acid 19 39 80  (i)  how does the concentration of acid affect the rate of reaction?   .    . ..  [1]  (ii)  which acid reacts most rapidly with the alloy?   . ..  [1]",
            "13": "13 0620/31/m/j/17 \u00a9 ucles 2017 [turn over (iii)  predict how long it would take for the alloy to decrease in mass by 1.0 g using phosphoric  acid of concentration 0.03 mol / dm3. time taken = .. hours  [1]  (iv)  suggest which one of these ph values is the ph of concentrated aqueous ethanoic acid.  draw a circle around the correct answer. ph 4                    ph 7                    ph 10                    ph 13 [1] [total: 14]",
            "14": "14 0620/31/m/j/17 \u00a9 ucles 20177  carbon is an element in group iv of the periodic table. it reacts with oxygen to form carbon dioxide.  (a)  the energy level diagram for this reaction is shown. energyc + o2 co2   explain how this diagram shows that the reaction is exothermic.   ... .   ... ...  [1]  (b)  carbon monoxide, carbon dioxide and methane are all atmospheric pollutants.  \u25cf  give the sources of these gases.  \u25cf  describe the effects that both carbon dioxide and methane have on the environment.  \u25cf  state an adverse effect of carbon monoxide on health.   ... .   ... .   ... .   ... .   ... .   ... .   ... .   ... .   ... .   ... ...  [5]",
            "15": "15 0620/31/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. (c)  calcium carbonate decomposes to form calcium oxide (lime) and carbon dioxide.  (i)  state one use of calcium oxide.   . ..  [1]  (ii)  calculate the relative formula mass of calcium carbonate, caco3.   show all your working.   use your periodic table to help you. relative formula mass = ..  [2]  (d)  carbon and magnesium are both insoluble in water.   carbon does not react with hydrochloric acid but magnesium reacts to form a soluble salt and  a gas which escapes into the air.   suggest how you could prepare a pure dry sample of carbon from a mixture of carbon powder  and magnesium powder.   ... .   ... .   ... .   ... .   ... .   ... ...  [3] [total: 12]",
            "16": "16 0620/31/m/j/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013"
        },
        "0620_s17_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 theory (core) may/june 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib17 06_0620_32/3rp\u00a9 ucles 2017 *9365905616* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/m/j/17 \u00a9 ucles 2017 1 (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td\tand\te,\tare\tshown. a b c d e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\tatoms. \t\teach\tatom\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\twhich\tatom,\ta,\tb,\tc,\td or e,  (i)\t\thas\ta\ttotal\tof\t8\telectrons,\t ..\t\t[1]  (ii)\t\tis\tin\tgroup\tiii\tof\tthe\tperiodic\t table,\t ..\t\t[1]  (iii)\t has\t13\tprotons,\t ..\t\t[1]  (iv)\t\tis\ta\tnoble\tgas,\t ..\t\t[1]  (v)\t\tforms\ta\tstable\tion\twith\ta\tsingle\tnegative \tcharge?\t ..\t\t[1]  (b)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\tthe\tsulfur\tatom\t and\toxide\tion\tshown. number\tof\telectrons number\tof\tneutrons number\tof\tprotons 34s16 16 18o2\u2013 8 10 [3] [total:\t8]",
            "3": "3 0620/32/m/j/17 \u00a9 ucles 2017 [turn over 2 (a)\t\tthe\ttable\tshows\tthe\tions\tpresent\tin\ta\t1000\t cm3\tsample\tof\trainwater. ion present formula\tof\tionmass\tpresent in\tmg\t/\t1000\tcm3 calcium ca2+1 hydrogencarbonate hco3\u20133 magnesium mg2+1 potassium k+2 sodium na+9 silicate sio32\u20131 cl \u201317 \t\tanswer\tthese\tquestions\tusing\tthe\tinformation\tfrom\tthe\ttable.  (i)\t\tstate\tthe\tname\tof\tthe\tion\tcl \u2013.  \t ... \t\t[1]  (ii)\t\twhich\tpositive\tion\tis\tpresent\tin\tthe\thighest\tconcentration?  \t ... \t\t[1]  (iii)\t\tcalculate\tthe\tmass\tof\tpotassium\tions\tpresent\tin\t200\t cm3\tof\tthis\tsample. mass\tof\tpotassium\tions\t=\t..\tmg\t\t[1]  (iv)\t\tcalculate\t the\tmass\tof\tsolid\tformed\twhen\tall\tthe\twater\tis\tevaporated\t from\tthe\t1000\tcm3  sample. mass\tof\tsolid\tformed\t=\t..\tmg\t\t[1]  (v)\t\tname\tthe\tcompound\tcontaining\tna+\tions\tand\thco3\u2013\tions.  \t ... \t\t[1]",
            "4": "4 0620/32/m/j/17 \u00a9 ucles 2017  (b)\t\tdescribe\ta\ttest\tfor\tpotassium\tions.  test \t.  result \t.. [2]  (c)\t\tthe\tformulae\tof\tsome\tnitrates\tare\tgiven. \t \taluminium\tnitrate,\t al (no3)3 \t \tmagnesium\tnitrate,\tmg(no3)2 \t \tsodium\tnitrate,\tnano3 \t\tdeduce\tthe\tformula\tfor\tpotassium\tnitrate.  \t.. \t\t[1]  (d)\t\tmolten\tpotassium\tbromide\tcan\tbe\telectrolysed\tusing\tinert\telectrodes. \t\tpredict\tthe\tproducts\tof\tthis\telectrolysis\tat \t the\tnegative\telectrode\t(cathode),\t \t.. \t the\tpositive\telectrode\t(anode).\t \t.. [2] [total:\t10]",
            "5": "5 0620/32/m/j/17 \u00a9 ucles 2017 [turn over 3\t\tthe\tdiagram\tshows\tpart\tof\tthe\tstructures\t of\tthree\tsubstances,\t x,\ty\tand\tz,\tat\troom\ttemperature\t and\t pressure. na+i\u2013na+i\u2013 na+i\u2013na+i\u2013i\u2013na+i\u2013na+ xy zc o c o c oc o co ho h ho h ho h hoh ho h hoh  (a)\t\tdescribe\tsubstances\t x,\ty\tand\tz\tin\tterms\tof \t \u25cf\t \ttheir\tbonding, \t \u25cf\t \tthe\tarrangement\tof\ttheir\tparticles, \t \u25cf\t \tthe\tmotion\tof\ttheir\tparticles.  \t  \t  \t  \t  \t  \t  \t  \t  \t.. \t\t[5]",
            "6": "6 0620/32/m/j/17 \u00a9 ucles 2017  (b)\t\ta\tclosed\tgas\tsyringe\tcontains\tsubstance\t z. z end blocked gas syringe \t\tdescribe\twhat\thappens\tto\tthe\tvolume\tof\tsubstance\t z\tin\tthe\tsyringe\twhen\tthe\ttemperature\t is\t increased.\t the\tpressure\tremains\tconstant.\texplain\tyour\tanswer\tin\tterms\tof\tparticles.  \t  \t.. \t\t[2]  (c)\t\tdescribe\tthe\tcolour\tchange\twhen\tsubstance\t y\tis\tadded\tto\tanhydrous\tcopper( ii)\tsulfate.  \t.. \t\t[2]  (d)\t\tgive\ta\treason\twhy\tsubstance\t y\tis\ta\tcompound.  \t.. \t\t[1] [total:\t10]",
            "7": "7 0620/32/m/j/17 \u00a9 ucles 2017 [turn over 4\t\taluminium\tand\tzinc\tare\tboth\tmetals. \t\taluminium\tis\textracted\tfrom\tits\tpurified\tore\tby\telectrolysis.  (a) (i)\t\tstate\tthe\tname\tof\tan\tore\tof\taluminium.  \t ... \t\t[1]  (ii)\t\texplain\twhy\taluminium\t is\textracted\tfrom\tits\tpurified\tore\tby\telectrolysis\t and\tnot\tby\theating\t with\tcarbon.  \t .  \t ... \t\t[1]  (b)\t\taluminium\t reacts\twith\thydrochloric\t acid\tto\tform\taluminium\t chloride\tand\ta\tgas\twhich\t\u2018pops\u2019\twith\t a\tlighted\tsplint.  (i)\t\tidentify\tthis\tgas.  \t ... \t\t[1]  (ii)\t\tsuggest\ta\tpractical\tmethod\tfor\tinvestigating\t the\trate\tof\tthis\treaction\tinvolving\tcollection\t of\t the\tgas. \t you\tmay\tinclude\ta\tlabelled\tdiagram\tin\tyour\tanswer.  \t .  \t .  \t .  \t ... \t\t[3]  (c)\t\tstate\tone\tuse\tof\taluminium.\tgive\ta\treason\twhy\tit\tis\tused\tfor\tthis\tpurpose.  use \t. \t reason\t\t  [2]",
            "8": "8 0620/32/m/j/17 \u00a9 ucles 2017  (d)\t\tgive\ttwo\tadvantages\tof\trecycling\taluminium. \t 1\t\t .  2 \t. [2]  (e)\t\tzinc\tis\textracted\tfrom\tzinc\toxide\tby\theating\tzinc\toxide\twith\tcarbon\tmonoxide. zno  +  co    zn  +  co2  (i)\t\thow\tdoes\tthis\tequation\tshow\tthat\tzinc\toxide\tis\treduced?  \t ... \t\t[1]  (ii)\t\tthe\tenergy \tlevel\tdiagram\tfor\tthis\treaction\tis\tshown. energyzn + co2 zno + co \t \texplain\thow\tthis\tdiagram\tshows\tthat\tthe \treaction\tis\tendothermic.  \t .  \t ... \t\t[1] [total:\t12]",
            "9": "9 0620/32/m/j/17 \u00a9 ucles 2017 [turn over question 5 starts on the next page.",
            "10": "10 0620/32/m/j/17 \u00a9 ucles 2017 5\t\tthe\tstructure\tof\tlactic\tacid\tis\tshown. hoc hch o o h hch  (a) (i)\t\ton\tthe\tstructure\tshown\tdraw\ta\tcircle\taround\tthe\tcarboxylic\tacid\tfunctional\tgroup.\t [1]  (ii)\t\tstate\tthe\tname\tof\tone\tother\tfunctional\tgroup\tfound\tin\tlactic\tacid.  \t ... \t\t[1]  (b)\t\tgive\tthe\tmolecular\t formula\tof\tlactic\tacid\tshowing\tthe\tnumber\tof\tcarbon,\thydrogen\t and\toxygen\t atoms.  \t.. \t\t[1]  (c)\t\tcomplete\tthe\tstructure\tof\tethanol.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds. cc [2]  (d)\t\tthe\ttable\tshows\tthe\tproperties\tof\tsome\talcohols. alcoholmelting\tpoint /\t\u00b0cboiling\tpoint /\t\u00b0cvolatility methanol \u201398 65 decreases ethanol \u2013114 propanol \u2013126 98 butanol \u201389 117  (i)\t\twhat\tis\tthe\tmeaning\tof\tthe\tterm\tvolatility?  \t ... \t\t[1]  (ii)\t\twhich\talcohol\tin\tthe\ttable\thas\tthe\thighest\tmelting\tpoint?  \t ... \t\t[1]",
            "11": "11 0620/32/m/j/17 \u00a9 ucles 2017 [turn over  (iii)\t\tpredict\tthe\tboiling\tpoint\tof\tethanol.  \t ... \t\t[1]  (iv)\t\twhat\tis\tthe\tstate\tof\tpropanol\tat\t120\t \u00b0c?\texplain\tyour\tanswer.  \t .  \t ... \t\t[2]  (e) (i)\t\tcomplete\tthis\tchemical\tequation\tfor\tthe \tincomplete\tcombustion\tof\tmethanol. ch3oh\t\t+\t\t...\t\t \t\tco\t\t+\t\t..h2o [2]  (ii)\t\tcalculate\tthe\trelative\tmolecular\tmass\tof \tmethanol,\tch3oh. \t \tshow\tall\tyour\tworking. \t \tuse\tyour\tperiodic\t table\tto\thelp\tyou. relative\tmolecular\tmass\t=\t..\t\t[2] [total:\t14]",
            "12": "12 0620/32/m/j/17 \u00a9 ucles 2017 6 (a)\t\tthe\ttable\tshows\tthe\tproperties\tof\tsome\ttypes\tof\tsteel. type of steeldensity in\tg\t/\tcm3resistance to corrosionrelative strengthrelative hardness l 7.80 poor 4.8 200 m 7.82 very\tgood 5.1 210 n 7.85 good 4.6 210 \t\twhich\ttype\tof\tsteel,\tl,\tm or n,\twould\tbe\tbest\tto\treinforce\tconcrete? \t\tgive\ttwo\treasons\tfor\tyour\tanswer. \t type\tof\tsteel\t. \t reason\t1\t\t . \t reason\t2\t\t . [2]  (b)  steel\tis\tan\talloy. \t\twhich\tdiagram,\t p,\tq,\tr or s,\trepresents\tan\talloy? fefefefe fefefefe fefefefecfecfe fefefec fecfefesssc sccs cssccccc cccc cccc pq rs  \t.. \t\t[1]  (c)\t\tiron\tis\ta\ttransition\telement. \t\tstate\tthree\tproperties\tof\ttransition\telements\twhich\tare\t not\tshown\tby\tgroup\ti\telements. \t 1\t\t .  2 \t. \t 3\t\t . [3]  (d)\t\tiron\treacts\twith\thydrochloric\tacid\tto\tform\tiron( ii)\tchloride\tand\thydrogen. \t\tcomplete\tthe\tchemical\tequation\tfor\tthis\treaction. fe\t\t+\t\t..hc l    fecl 2\t\t+\t\t... [2]",
            "13": "13 0620/32/m/j/17 \u00a9 ucles 2017 [turn over  (e)\t\tsome\tinformation\tabout\tthe\treaction\tof\tfour\tmetals\t with\toxygen\tis\tgiven. \t copper:\t surface\tturns\tblack\tslowly\twhen\theated\tstrongly \t iron:\t thin\twire\tburns\twhen\theated\tstrongly \t gold:\t remains\ta\tgold\tcolour\twhen\theated\tstrongly \t potassium:\tbursts\tinto\tflame\twhen\theated\tgently \t\tlist\tthese\tmetals\tin\torder\tof\ttheir\treactivity.\tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive [2]  (f)\t\tthe\ttable\tcompares\t the\ttime\ttaken\tfor\treaction\tof\tiron\twith\tmethanoic\t acid,\tphosphoric\t acid\tand\t propanoic\t acid,\teach\tat\tthree\tdifferent\tconcentrations.\t the\ttime\ttaken\tfor\tthe\tiron\tto\tdecrease\t in\tmass\tby\t1.0\t g\twas\tmeasured.\t all\tother\tconditions\twere\tkept\tthe\tsame. acidtime\ttaken\tfor\treaction\t /\thours concentration\tof\tacid 0.01\tmol\t/\tdm3concentration\tof\tacid 0.02\tmol\t/\tdm3concentration\tof\tacid 0.04\tmol\t/\tdm3 methanoic\tacid 98 47 20 phosphoric\tacid 9 5 2 propanoic\tacid 220 102 45  (i)\t\thow\tdoes\tthe\tconcentration\tof\tacid\taffect\tthe\trate\tof\treaction?  \t .  \t ... \t\t[1]  (ii)\t\twhich\tacid \treacts\tmost\trapidly\twith\tthe\tiron?  \t ... \t\t[1]  (iii)\t\tpredict\thow\tlong\tit\twould\ttake\tfor\tthe\tiron\tto\tdecrease\tin\tmass\tby\t1.0\tg\tusing\tpropanoic\t acid\t of\tconcentration\t0.03\t mol\t/\tdm3. time\ttaken\t=\t..\thours\t\t[1]  (iv)\t\tsuggest\twhich\t one\tof\tthese\tph\tvalues\tis\tthe\tph\tof\tconcentrated\t aqueous\tphosphoric\t acid.\t draw\ta\tcircle\taround\tthe\tcorrect\tanswer. ph\t2\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t7\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t9\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t13 [1] [total:\t14]",
            "14": "14 0620/32/m/j/17 \u00a9 ucles 2017 7\t\tsulfur\tis\tan\telement\tin\tgroup\tvi\tof\tthe\tperiodic\t table.  (a)\t\twhat\tis\tthe\tmeaning\tof\tthe\tterm\telement ?  \t  \t.. \t\t[1]  (b)\t\tgive\tone\tsource\tand\tone\tuse\tof\tsulfur.  source \t  use \t. [2]  (c)\t\twhen\tsulfur\tvapour\ttouches\ta\tcold\tsurface\tit\tchanges\tdirectly\tto\ta\tsolid. \t\twhat\tis\tthe\tname\tgiven\tto\tthis\tchange\tof\tstate?  \t.. \t\t[1]  (d)\t\tsulfur\tdioxide\tand\toxides\tof\tnitrogen\tare\tboth\tatmospheric\tpollutants. \t \u25cf\t \tgive\tthe\tsources\tof\tthese\tgases. \t \u25cf\t \tdescribe\tthe\teffects\tof\tthese\tpollutants\ton\tthe\tenvironment. \t \u25cf\t \tdescribe\tthe\teffects\tof\tthese\tpollutants\ton\thealth.  \t  \t  \t  \t  \t  \t  \t.. \t\t[5]",
            "15": "15 0620/32/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (e)\t\tsulfur\tand\tzinc\tare\tboth\tinsoluble\tin\twater. \t\tsulfur\tdoes\t not\treact\twith\thydrochloric\t acid\tbut\tzinc\treacts\tto\tform\ta\tsoluble\tsalt\tand\ta\tgas\t which\tescapes\tinto\tthe\tair. \t\tsuggest\thow\tyou\tcould\tprepare\ta\tpure\tdry\tsample\tof\tsulfur\tfrom\ta\tmixture\tof\tsulfur\tpowder\t and\tzinc\tpowder.  \t  \t  \t  \t  \t  \t.. \t\t[3] [total:\t12]",
            "16": "16 0620/32/m/j/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s17_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 theory (core) may/june 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib17 06_0620_33/3rp\u00a9 ucles 2017 *6485603039* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/33/m/j/17 \u00a9 ucles 2017 1 (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td\tand\te,\tare\tshown. a b c d e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\tatoms. \t\teach\tatom\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\twhich\tatom,\ta,\tb,\tc,\td or e,  (i)\t\tis\tin\tgroup\tviii\tof\tthe\tperiodic\t table,\t ..\t\t[1]  (ii)\t\tis\ta\tchlorine \tatom,\t ..\t\t[1]  (iii)\t\thas\t17\tprotons\tin\tits\tnucleus,\t ..\t\t[1]  (iv)\t\tis\tan\tatom\tof\tan\telement\tin\tthe\tsame\tperiod\tas\tcarbon,\t ..\t\t[1]  (v)\t\tis\tan\tatom\tof\ta\tmetal?\t ..\t\t[1]  (b)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\tthe\tmagnesium\t atom\tand\tcalcium\tion\tshown. number\tof\telectrons number\tof\tneutrons number\tof\tprotons 26mg12 12 44ca2+ 20 24 [3] [total:\t8]",
            "3": "3 0620/33/m/j/17 \u00a9 ucles 2017 [turn over 2 (a)\t\tthe\ttable\tshows\tthe\tions\tpresent\tin\ta\t1000\t cm3\tsample\tof\tmineral\twater. ion present formula\tof\tionmass\tpresent in\tmg\t/\t1000\tcm3 calcium ca2+52 chloride cl \u201310 hydrogencarbonate hco3\u201350 magnesium mg2+ sodium na+12 sulfate so42\u201310 no3\u20138 total 150 \t\tanswer\tthese\tquestions\tusing\tthe\tinformation\tfrom\tthe\ttable.  (i)\t\tcalculate\tthe\tmass\tof\tmagnesium\tions\tin\tthe\t1000\t cm3\tsample\tof\tmineral\twater. mass\tof\tmagnesium\tions\t=\t..\tmg\t\t[1]  (ii)\t\twhich\tnegative\tion\tis\tpresent\tin\tthe\thighest\tconcentration?  \t ... \t\t[1]  (iii)\t\tstate\tthe\tname\tof\tthe\tion\tno3\u2013.  \t ... \t\t[1]  (iv)\t\tcalculate\tthe\tmass\tof\thydrogencarbonate\tions\tpresent\tin\t250\t cm3\tof\tthis\tsample. mass\tof\thydrogencarbonate\tions\t=\t..\tmg\t\t[1]",
            "4": "4 0620/33/m/j/17 \u00a9 ucles 2017  (b)\t\twhen\tnitrate\tions\tare\twarmed\twith\taqueous\tsodium\thydroxide\t and\taluminium\t foil,\tammonia\t gas\tis\tgiven\toff. \t\tdescribe\ta\ttest\tfor\tammonia\tgas.  test \t.  result \t.. [2]  (c)\t\tthe\tformulae\tof\tsome\tbromides\tare\tgiven. \t aluminium\tbromide,\t al br3 \t magnesium\tbromide,\tmgbr2 \t sodium\tbromide,\tnabr \t\tdeduce\tthe\tformula\tfor\tcalcium\tbromide.  \t.. \t\t[1]  (d)\t\tmolten\tcalcium\tbromide\tcan\tbe\telectrolysed\tusing\tinert\telectrodes.  (i)\t\tpredict\tthe\tproducts\tof\tthis\telectrolysis\tat \t the\tnegative\telectrode\t(cathode),\t \t ... \t the\tpositive\telectrode\t(anode).\t \t ... [2]  (ii)\t\tgraphite\telectrodes\tare\tinert. \t \tgive\tthe\tname\tof\tone\tother\tsubstance\tthat\tcan\tbe\tused\tto\tmake\tan\tinert\telectrode.  \t ... \t\t[1] [total:\t10]",
            "5": "5 0620/33/m/j/17 \u00a9 ucles 2017 [turn over 3\t\tthe\tdiagram\tshows\tpart\tof\tthe\tstructures\t of\tthree\tsubstances,\t p,\tq\tand\tr,\tat\troom\ttemperature\t and\tpressure. k+i\u2013k+ k+i\u2013 k+k+i\u2013i\u2013 k+i\u2013i\u2013 pq rbrbrbr brbrbr brbr brbrbrbrbrbr ararararar arar arar  (a)\t\tdescribe\tsubstances\t p,\tq\tand\tr\tin\tterms\tof \t \u25cf\t \ttheir\tbonding, \t \u25cf\t \tthe\tarrangement\tof\ttheir\tparticles, \t \u25cf\t \tthe\tmotion\tof\ttheir\tparticles.  \t  \t  \t  \t  \t  \t  \t  \t  \t.. \t\t[5]",
            "6": "6 0620/33/m/j/17 \u00a9 ucles 2017  (b)\t\ta\tclosed\tgas\tsyringe\tcontains\tsubstance\t r.\tthe\tsyringe\tis\theated\tin\ta\twater\tbath. r end blockedwater bathgas syringe heat \t\tdescribe\twhat\thappens\tto\tthe\tvolume\tof\tsubstance\t r\tin\tthe\tsyringe.\tthe\tpressure\tremains\t constant.\texplain\tyour\tanswer\tin\tterms\tof\tparticles.  \t  \t.. \t\t[2]  (c)\t\tsubstance\tp\tundergoes\tphysical\tand\tchemical\tchanges.   which two\tof\tthe\tfollowing\tare\tphysical\tchanges?\texplain\tyour\tanswer.  a\t\tsubstance\tp\treacts\twith\tconcentrated\tsulfuric\tacid.  b\t\tiodine\tforms\twhen\tchlorine\tis\tadded\tto\tan\taqueous\tsolution\tof\tsubstance\t p.  c  substance\tp\tboils\tat\t1330\t \u00b0c.  d  substance\tp\tdissolves\teasily\tin\twater.  \t  \t  \t.. \t\t[3]  (d)\t\tgraphite\thas\ta\tgiant\tcovalent\tstructure\tcontaining\tlayers\tof\tcarbon\tatoms. \t\tgraphite\tis\tused\tto\tmake\tinert\telectrodes\tfor\telectrolysis. \t\tstate\tone\tother\tuse\tof\tgraphite\tand\texplain\thow\tthis\tuse\tis\trelated\tto\tits\tstructure.  \t  \t.. \t\t[2] [total:\t12]",
            "7": "7 0620/33/m/j/17 \u00a9 ucles 2017 [turn over 4\t\tiron\tis\textracted\tfrom\tits\tore\tby\theating\tthe\tore\twith\tcarbon\tin\ta\tblast\tfurnace.  (a) (i)\t\tstate\tthe\tname\tof\tan\tore\tof\tiron.  \t ... \t\t[1]  (ii)\t\tin\tthe\tblast\tfurnace,\tiron( iii)\toxide\tis\treduced\tby\tcarbon\tmonoxide. \t \texplain\thow\tthe\tcarbon\tmonoxide\tis\tformed\tin\tthe\tblast\tfurnace.  \t .  \t ... \t\t[2]  (iii)\t\tbalance\tthe \tchemical\tequation\tfor\tthis\treaction. fe2o3\t\t+\t\t3co\t\t \t\t..fe\t\t+\t\t..co2 [2]  (iv)\t\thow\tdoes\tthis\tequation\tshow\tthat\tiron( iii)\toxide\tis\treduced?  \t ... \t\t[1]  (v)\t\tcalculate\tthe\trelative\tformula\tmass\tof\tiron( iii)\toxide,\tfe2o3. \t \tshow\tall\tyour\tworking. \t \tuse\tyour\tperiodic\t table\tto\thelp\tyou. relative\tformula\tmass\t=\t..\t\t[2]",
            "8": "8 0620/33/m/j/17 \u00a9 ucles 2017  (b)\t\tiron\treacts\twith\thydrochloric\t acid\tto\tform\tiron( ii)\tchloride\tand\ta\tgas\twhich\t\u2018pops\u2019\twith\ta\tlighted\t splint.  (i)\t\tidentify\tthis\tgas.  \t ... \t\t[1]  (ii)\t\tsuggest\ta\tpractical\tmethod\tfor\tinvestigating\t the\trate\tof\tthis\treaction\tinvolving\tcollection\t of\t the\tgas. \t \tyou\tmay\tinclude\ta\tlabelled\tdiagram\tin\tyour\tanswer.  \t .  \t .  \t .  \t ... \t\t[3]  (c)\t\tdescribe\ta\ttest\tfor\tiron( ii)\tions.  test \t.  result \t.. [2]  (d)\t\tgive\ttwo\tadvantages\tof\trecycling\tsteel. \t 1\t\t . \t 2\t\t . [2] [total:\t16]",
            "9": "9 0620/33/m/j/17 \u00a9 ucles 2017 [turn over 5\t\tglycolic\tacid\tis\tfound\tin\tthe\tstalks\tof\tsugar-cane \tplants. \t\tthe\tstructure\tof\tglycolic\tacid\tis\tshown. h cco o hoh h  (a)\t\ton\tthe\tstructure\tshown\tdraw\ta\tcircle\taround\tthe\tcarboxylic\tacid\tfunctional\tgroup.\t [1]  (b)\t\tgive\tthe\tmolecular\t formula\tof\tglycolic\tacid\tshowing\tthe\tnumber\tof\tcarbon,\thydrogen\t and\t oxygen\tatoms.  \t.. \t\t[1]  (c)\t\tsuggest\thow\tyou\tcould\tobtain\ta\tsolution\tcontaining \tglycolic\tacid\tfrom\tsugar-cane\tplants.  \t  \t  \t.. \t\t[3]  (d)\t\tnitric\tacid\tcan\toxidise\tglycolic\tacid. \t\twhat\tis\tthe\tmeaning\tof\tthe\tterm\toxidation ?  \t.. \t\t[1]",
            "10": "10 0620/33/m/j/17 \u00a9 ucles 2017  (e)\t\tthe\ttable\tshows\tthe\tproperties\tof\tsome\tcarboxylic\tacids. carboxylic\tacidnumber\tof carbon\tatoms in\tone\tmoleculemelting\tpoint in \u00b0cboiling\tpoint in \u00b0cdensity in\tg\t/\tcm3 methanoic\tacid 1 8 101 1.220 ethanoic\tacid 2 17 118 1.049 propanoic\tacid 3 \u201321 0.993 butanoic\tacid 4 \u20135 164 0.958  (i)\t\tdescribe\thow\tthe\tdensity\tof\tthe\tcarboxylic\t acids\tvaries\twith\tthe\tnumber\tof\tcarbon\tatoms\t in\tone\tmolecule.  \t ... \t\t[1]  (ii)\t\tpredict\tthe\tboiling\tpoint\tof\tpropanoic\tacid.  \t ... \t\t[1]  (iii)\t\twhat\tis\tthe\tstate\tof\tbutanoic\tacid\tat\t\u201310 \t\u00b0c?\texplain\tyour\tanswer.  \t .  \t ... \t\t[2] [total:\t10]",
            "11": "11 0620/33/m/j/17 \u00a9 ucles 2017 [turn over 6 (a)\t\tthe\ttable\tshows\tthe\tproperties\tof\tsome\talloys. alloydensity in\tg\t/\tcm3relative hardnessrelative strengthrelative electrical conductivitycost j 7.8 4.0 24.0 1.1 cheap k 2.8 2.5 7.5 3.8 expensive l 11.3 0.2 1.5 0.5 cheap m 10.2 5.5 16.5 0.2 very\texpensive \t\tuse\tthe\tinformation\tin\tthe\ttable\tto\tanswer\tthe\tquestions.  (i)\t\twhich\talloy \twould\tbe\tmost\tuseful\tfor\tmaking\ta\tbridge? \t \tgive\ttwo\treasons\tfor\tyour\tanswer. \t alloy\t. \t reason\t1\t\t .. \t reason\t2\t\t .. [2]  (ii)\t\twhich\talloy \tis\tbest\tto\tmake\tthe\ttips\tof\thigh-speed\tdrills? \t \tgive\tone\treason\tfor\tyour\tanswer. \t alloy\t. \t reason\t\t . [1]  (iii)\t\twhich\talloy \tis\tbest\tto\tmake\taircraft\tbodies? \t \tgive\tone\treason\tfor\tyour\tanswer. \t alloy\t. \t reason\t .. [1]",
            "12": "12 0620/33/m/j/17 \u00a9 ucles 2017  (b)\t\ta\tstudent\ttook\tpieces\tof\tfour\tdifferent\tsteel\talloys,\t w,\tx,\ty\tand\tz,\teach\tof\tthe\tsame\tmass,\tand\t placed\tthem\tseparately\t into\thydrochloric\t acid.\tthe\tconcentration\t of\tacid\twas\tthe\tsame\tin\teach\t case\tand\tthe\tmetal\twas\tin\texcess.\t all\tother\tconditions\twere\tkept\tthe\tsame. \t\tthe\tstudent\tmeasured\t the\tmass\tof\teach\talloy\tat\tintervals\tas\tthe\treaction\tproceeded\t and\t calculated\tthe\tpercentage\tmass\tloss. \t\tthe\tresults\tfor\talloys\tw,\tx\tand\ty\tare\tshown\ton\tthe\tgraph. 100 80 6040 20 0 0 1234 time  / days56 7percentage mass lossw x y  (i)\t\talloy\tz\treacts\tfaster\twith\thydrochloric\tacid\tthan\talloy\t w. \t \ton\tthe\tgraph,\tdraw\ta\tline\twhich\tcould\trepresent\tthe\tpercentage\t mass\tloss\tof\talloy\tz\twith\t time. [2]  (ii)\t\twhich\talloy \tshowed\tthe\tleast\tpercentage\tmass\tloss\tafter\t3\tdays?  \t ... \t\t[1]  (iii)\t\thow\tlong\tdid\tit\ttake\tfor\talloy\tx\tto\tlose\t40%\tof\tits\tmass?  \t ... \t\t[1]  (iv)\t\tsuggest\thow\tthe\tfollowing\tfactors\taffect\tthe\trate\tof\tmass\tloss. \t increasing\tthe\ttemperature\t \t . \t increasing\tthe\tconcentration\tof\tthe\tacid\t \t. [2]",
            "13": "13 0620/33/m/j/17 \u00a9 ucles 2017 [turn over  (c)\t\tthe\tconcentration\tof\tan\tacid\tcan\tbe\tfound\tby\ttitrating\tit\twith\taqueous\tsodium\thydroxide. \t\tsuggest\twhich\t one\tof\tthese\tph\tvalues\tis\tthe\tph\tof\tconcentrated\taqueous\tsodium\thydroxide. \t\tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. ph\t1\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t3\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t7\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t12 [1] [total:\t11]",
            "14": "14 0620/33/m/j/17 \u00a9 ucles 2017 7\t\twater\tis\ta\tsimple\tcovalent\tcompound.  (a)\t\tcomplete\tthe\tdiagram\tto\tshow\tthe\telectrons\tin\tthe\t covalent\tbonds\tin\ta\twater\tmolecule. o h h [1]  (b)\t\tgive\t two\tphysical\tproperties\t which\tdistinguish\t a\tsimple\tcovalent\tcompound\t from\tan\tionic\t compound. \t 1\t\t . \t 2\t\t . [2]  (c)\t\tsome\tinformation\tabout\tthe\treaction\tof\tfour\tmetals\t with\twater\tis\tgiven. \t cerium:\t reacts\tslowly\twith\tcold\twater \t iron:\t reacts\twith\tsteam\tonly\twhen\textremely\thot \t lithium:\t reacts\trapidly\twith\tcold\twater \t magnesium:\treacts\tslowly\twith\thot\twater \t\tlist\tthese\tmetals\tin\torder\tof\ttheir\treactivity.\tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive [2]",
            "15": "15 0620/33/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (d) (i)\t\tstate\tthe\tconditions\tneeded\tfor\tiron\tto\trust.  \t .  \t ... \t\t[2]  (ii)\t\tstate\ttwo\tmethods\tof\trust\tprevention. \t 1\t\t .. \t 2\t\t .. [2]  (e)\t\tstarting\twith\tan\taqueous\tsolution\tof\tcopper( ii)\tsulfate,\tdescribe\thow\tyou\tcould\tobtain\ta\tpure\t dry\tsample\tof\tcopper( ii)\tsulfate\tcrystals.  \t  \t  \t  \t.. \t\t[2]  (f)\t\tcarbon\tdioxide\tand\twater\tare\tformed\twhen\thydrocarbons\tburn. \t\tcomplete\tthe\tchemical\tequation\tfor\tthe\tcombustion\tof\tbutene. c4h8\t\t+\t\t6o2  \t\t..co2\t\t+\t\t..h2o [2] [total:\t13]",
            "16": "16 0620/33/m/j/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s17_qp_41.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/41   paper 4 theory (extended) may/june 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib17 06_0620_41/4rp\u00a9 ucles 2017 *3843148954* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/41/m/j/17 \u00a9 ucles 2017 1  this question is about subatomic particles.  (a)\t\tdefine\tthe\tterms  proton number ,  ..     nucleon number .      [3]  (b)  why is the 1h1 hydrogen atom the only atom to have an identical proton number and nucleon  number?      ..   [1]  (c)  complete the table to show the number of protons, neutrons and electrons in the atoms and  ions given. number of protonsnumber of neutronsnumber of electrons 19f 9 26mg 12 31p3\u2013 87sr2+ [6]  (d) (i)\t \twrite\tthe\tformula\tof\tthe\tcompound\tformed\tfrom\tfluorine\tand\tmagnesium.   ...   [1]  (ii)  write the formula of the compound formed from sr2+ and p3\u2013.   ...   [1] [total: 12]",
            "3": "3 0620/41/m/j/17 \u00a9 ucles 2017 [turn over 2  some oxides of some elements are listed.  co co2  na2o mgo al 2o3  sio2 p4o10 so2 cl 2o7 cr2o3  (a)  answer the following questions using only oxides from the list. each oxide may be used once,  more than once or not at all.   give the formula of an oxide  (i)  which is the main cause of acid rain,  ..  (ii)  which would give a solution of ph 14 when added to water,  ...  (iii)  which is coloured,  ...  (iv)  which is the major impurity in iron ore,    (v)  which is amphoteric,   (vi)  which is neutral.  .. [6]  (b)  amphoteric oxides and neutral oxides are different from each other.  (i)  what is meant by the term amphoteric  oxide?   .   ...   [1]  (ii)  what is meant by the term neutral  oxide ?   .   ...   [1] [total: 8]",
            "4": "4 0620/41/m/j/17 \u00a9 ucles 2017 3  magnesium sulfate and lead( ii) sulfate are examples of salts.  (a)  a student prepared magnesium sulfate crystals starting from magnesium carbonate. the  student carried out the experiment in four steps.  step 1  the student added excess magnesium carbonate to a small volume of   dilute sulfuric acid until no more magnesium carbonate would react.  step 2\t\tthe\tstudent\tfiltered\tthe\tmixture.  step 3\t\tthe\tstudent\theated\tthe\tfiltrate\tobtained\tfrom\t step 2 until it was saturated.  step 4\t\tthe\tstudent\tallowed\tthe\thot\tfiltrate\tto\tcool\tto\troom\ttemperature\t and\tthen\tremoved\t the crystals which formed.  (i)\t\thow\tdid\tthe \tstudent\tknow\twhen\tthe\treaction\thad\tfinished\tin\t step 1?   ...   [1]  (ii)  name the residue in step 2.   ...   [1]  (iii)  a saturated solution forms in step 3.   what is a saturated solution?   .   ...   [2]  (iv)  explain why magnesium sulfate crystals form during step 4.   .   ...   [1]",
            "5": "5 0620/41/m/j/17 \u00a9 ucles 2017 [turn over  (b)  magnesium sulfate crystals are hydrated. another student heated some hydrated  magnesium sulfate crystals in a crucible and obtained the following results.  mass of hydrated magnesium sulfate crystals = 4.92 g  mass of water removed = 2.52 g  (i)  calculate the number of moles of water removed. moles of water = . mol  [1]  (ii)  calculate the number of moles of anhydrous magnesium sulfate remaining in the crucible.   the mr of anhydrous magnesium sulfate is 120. moles of anhydrous magnesium sulfate = . mol  [1]  (iii)  calculate the ratio of moles of anhydrous magnesium sulfate : moles of water. give your  answer as whole numbers. ratio =  :   [1]  (iv)  suggest the formula of hydrated magnesium sulfate crystals. formula of hydrated magnesium sulfate crystals =   [2]",
            "6": "6 0620/41/m/j/17 \u00a9 ucles 2017  (c)  lead( ii) sulfate, pbso4, is insoluble.   describe how you would prepare a pure dry sample of lead( ii) sulfate crystals starting from  solutions of lead( ii) nitrate and sodium sulfate.   include a series of key steps in your answer.                        ..   [4]  (d)  write the ionic equation for the reaction which takes place between solutions of lead( ii) nitrate  and sodium sulfate.   include state symbols.   ..   [2] [total: 16]",
            "7": "7 0620/41/m/j/17 \u00a9 ucles 2017 [turn over 4  zinc is a very important metal.  (a)\t\tzinc\tis\textracted\tfrom\tits\tore,\tzinc\tblende.\tzinc\tblende\tcontains\tzinc\tsulfide,\tzns. \t \tzinc\tsulfide\tis\tconverted\tto\tzinc\toxide\tin\tan\tindustrial\tprocess.  (i)\t\tdescribe\thow\tzinc\tsulfide\tis\tconverted\tto\tzinc\toxide\tin\tthis\tindustrial\tprocess.   .   ...   [1]  (ii)  write the chemical equation for this reaction.   ...   [2]  (b)  zinc oxide is then reduced in a furnace.  (i)  name the substance added to the furnace to reduce the zinc oxide.   ...   [1]  (ii)  describe how the pure zinc is removed from the furnace and collected.   .   .   ...   [2]",
            "8": "8 0620/41/m/j/17 \u00a9 ucles 2017  (c)  when rods of zinc and copper are placed into dilute sulfuric acid as shown, electricity is  generated. copper rod dilute sulfuric acidzinc ro dbulb  (i)  write the ionic half-equation for the reaction occurring at the zinc rod.   ...   [2]  (ii)  write the ionic half-equation for the reaction occurring at the copper rod.   ...   [2]  (iii)  the copper rod was replaced by an iron rod.   suggest the change, if any, in the intensity of the light emitted from the bulb and give a  reason for your answer.  change    reason  .   . [2] [total: 12]",
            "9": "9 0620/41/m/j/17 \u00a9 ucles 2017 [turn over 5  when barium carbonate is added to dilute hydrochloric acid, carbon dioxide gas is formed.   a student carried out an experiment to measure the volume of gas formed as a reaction proceeds.  the student added a small mass of powdered barium carbonate to an excess of 0.1 mol / dm3  hydrochloric acid. a graph of the results was drawn.   the graph is shown. 400 300 200 100 0volum e of gas / cm3 03 06 09 0120 time  / s150 180 210 240  (a)  name the two pieces of apparatus needed to take the measurements shown on the graph.  1  .  2  . [1]  (b)  on the axes below, sketch a graph to show how the rate of reaction changes as the reaction  proceeds.   assume the initial rate of reaction is represented by the point at x. 00 120 90 60 30 time  / srate of reactionx [2]",
            "10": "10 0620/41/m/j/17 \u00a9 ucles 2017  (c)  the total volume of gas collected was 180 cm3 at room temperature and pressure.   calculate the mass, in grams, of barium carbonate used. baco3  +  2hcl    bacl 2  +  h2o  +  co2 mass of barium carbonate = . g  [3]  (d)  the original graph has been drawn again.   on the grid, draw the graph expected if the same mass of barium carbonate is added as large  lumps instead of as a powder. all other conditions are the same as in the original experiment.   explain why your graph is different from the original graph. 400 300 200100 0volum e of gas / cm3 03 06 09 0120 time  / s150 180 210 240         ..   [2]",
            "11": "11 0620/41/m/j/17 \u00a9 ucles 2017 [turn over  (e)  the original graph has been drawn again.   on the grid, draw the graph expected if the concentration of dilute hydrochloric acid is changed  from 0.1 mol / dm3 to 0.2 mol / dm3. all other conditions are the same as in the original experiment.   explain, in terms of particles, why your graph is different from the original graph. 400 300 200 100 0volum e of gas / cm3 03 06 09 0120 time  / s150 180 210 240            ..   [4]  (f)  the experiment is changed and the mass of powdered barium carbonate is doubled. all other  conditions are the same as in the original experiment. the acid is still in excess.   deduce the volume of gas formed at room temperature and pressure, in cm3, in this experiment. volume of gas = .. cm3  [1] [total: 13]",
            "12": "12 0620/41/m/j/17 \u00a9 ucles 2017 6  the alkenes and alkanes are both examples of homologous series which are hydrocarbons.  (a)  what is meant by the term hydrocarbon ?      ..   [2]  (b)  give three characteristics of an homologous series.  1  .  2  .  3  . [3]  (c)  name and draw the structure of the second member of the alkene homologous series.   show all of the atoms and all of the bonds.  name  ..  structure [2]  (d)  alcohols can be made from alkenes.   name the reagent and conditions needed to convert an alkene into an alcohol.      ..   [2]",
            "13": "13 0620/41/m/j/17 \u00a9 ucles 2017 [turn over  (e)  the alcohol butanol, ch3ch2ch2ch2oh, can be converted into a carboxylic acid with four  carbon atoms.  (i)  name the carboxylic acid formed from butanol and draw its structure. show all of the  atoms and all of the bonds.  name  ...  structure [2]  (ii)  ethanoic acid can be formed from ethanol by fermentation. it can also be formed by the addition of a suitable chemical reagent.  name the reagent needed to convert ethanol into ethanoic acid.   ...   [2]  (iii)  state the type of chemical change which occurs when ethanol is converted into  ethanoic acid.   ...   [1]  (f)  describe how a student could prepare the ester methyl ethanoate in a school laboratory.   in your description give \t \u25cf\t \tthe\tnames\tof\tthe\ttwo starting organic chemicals, \t \u25cf\t \tthe\tessential\treaction\tconditions\tneeded, \t \u25cf\t a\tchemical\tequation\tfor\tthe\treaction.                        ..   [5] [total: 19]",
            "14": "14 0620/41/m/j/17 \u00a9 ucles 2017blank page",
            "15": "15 0620/41/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.blank page",
            "16": "16 0620/41/m/j/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s17_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/42   paper 4 theory (extended) may/june 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib17 06_0620_42/5rp\u00a9 ucles 2017 *5924154296* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/m/j/17 \u00a9 ucles 2017 1 (a)  state the name of the process that is used to  (i)  separate oxygen from liquid air,   ...   [1]  (ii)  separate the individual dyes in ink,   ...   [1]  (iii)  produce ethanol from simple sugars,   ...   [1]  (iv)  obtain water from aqueous sodium chloride,   ...   [1]  (v)  separate the precipitate formed when aqueous silver nitrate is added to aqueous   sodium chloride.   ...   [1]  (b)  state what is meant by the terms  (i)  element ,   .   ...   [1]  (ii)  compound ,   .   ...   [1]  (iii)  ion.   .   ...   [1] [total: 8]",
            "3": "3 0620/42/m/j/17 \u00a9 ucles 2017 [turn over 2  carbon and silicon are elements in group iv of the periodic table. both carbon and silicon exist as  more than one isotope.  (a)\t\tdefine\tthe\tterm\tisotopes .      ..   [2]  (b)  complete the following table which gives information about carbon atoms and silicon atoms. carbon silicon proton number electronic structure nucleon number 12 28 number of neutrons in one atom [3]  (c)  silicon has a giant structure which is similar to the structure of diamond.  (i)  name the type of bond which is present between silicon atoms in silicon.   ...   [1]  (ii)  suggest two physical properties of silicon.   use your knowledge of structure and bonding to explain why silicon has these physical  properties.  property 1  ...  reason 1  ..  property 2  ...  reason 2  .. [4]  (d)  samples of air taken from industrial areas are found to contain small amounts of carbon monoxide.  (i)  explain how this carbon monoxide is formed.   .   ...   [2]  (ii)  state why carbon monoxide should not be inhaled.   ...   [1]",
            "4": "4 0620/42/m/j/17 \u00a9 ucles 2017  (e)  carbon dioxide, co2, is a gas at room temperature and pressure, whereas silicon( iv) oxide,  sio2, is a solid.  (i)  name the type of structure which the following compounds have.  carbon dioxide  ..   [1]  silicon( iv) oxide    [1]  (ii)  use your knowledge of structure and bonding to explain why carbon dioxide is a gas at  room temperature and pressure, whereas silicon( iv) oxide is a solid.   .   .   .   ...   [3]  (f)  silicon( iv) oxide is an acidic oxide. when silicon( iv) oxide reacts with alkalis, the salts formed  contain the ion sio32\u2013.   write a chemical equation for the reaction between silicon( iv) oxide and aqueous  sodium hydroxide.   ..   [2] [total: 20]",
            "5": "5 0620/42/m/j/17 \u00a9 ucles 2017 [turn over 3  this question is about nitrogen and some of its compounds.  (a)  nitrogen in the air can be converted into ammonia by the haber process. the chemical equation  for the reaction is shown. n2  +  3h2    2nh3  (i)  state the temperature and pressure used in the haber process.  temperature    pressure  .. [2]  (ii)  name the catalyst used in the haber process.   ...   [1]  (b)  the ammonia produced in the haber process can be oxidised to nitrogen( ii) oxide at 900 \u00b0c.   the reaction is exothermic.  (i)  balance the chemical equation for this reaction. 4nh3  +  .o2    .no  +  .h2o [2]  (ii)  suggest a reason, other than cost, why a temperature greater than 900 \u00b0c is not used.   ...   [1]  (iii)  suggest a reason why a temperature less than 900 \u00b0c is not used.   ...   [1]  (c)  nitrogen( ii) oxide can be reacted with oxygen and water to produce nitric acid as the only  product.   write a chemical equation for this reaction.   ..   [2]",
            "6": "6 0620/42/m/j/17 \u00a9 ucles 2017  (d)  describe how you would prepare a pure dry sample of copper( ii) nitrate crystals in the  laboratory using dilute nitric acid and solid copper( ii) carbonate.   include a series of key steps in your answer.   you should include a chemical equation for the reaction.                        ..   [6] [total: 15]",
            "7": "7 0620/42/m/j/17 \u00a9 ucles 2017 [turn over question 4 starts on the next page.",
            "8": "8 0620/42/m/j/17 \u00a9 ucles 2017 4  nickel, copper and zinc are three consecutive elements in the periodic table.   (a)  nickel and copper are transition elements.   state three chemical properties of transition elements.         ..   [3]  (b)  copper( ii) oxide is a basic oxide but zinc oxide is an amphoteric oxide. both oxides are  insoluble in water.   you are provided with a mixture of solid copper( ii) oxide and solid zinc oxide. describe how  you would obtain a sample of copper( ii) oxide from this mixture.            ..   [3]  (c)  three cells are set up each using two metals. cell 1 1.10  v electrolytezinc copper\u2013 + \u2013 +vcell 2 0.51  v electrolytezinc nickelvcell 3 .  v electrolytecopper nickelv  (i)  write the ionic half-equation for the reaction occurring at the zinc electrode in cell 1.   ...   [2]",
            "9": "9 0620/42/m/j/17 \u00a9 ucles 2017 [turn over  (ii)  put the three metals, copper, nickel and zinc, in order of reactivity.  most reactive        least reactive   [1]  (iii)  complete the labelling in cell 3 by writing the polarity (+/\u2013) of each electrode in the circles  and calculating the reading on the voltmeter. [2] [total: 11]",
            "10": "10 0620/42/m/j/17 \u00a9 ucles 2017 5 (a)  the elements in group vii are known as the halogens. some halogens react with aqueous  solutions of halides.  (i)  complete the table by adding a \uf033 to indicate when a reaction occurs and a \uf037 to indicate  when no reaction occurs. aqueous potassium chlorideaqueous potassium bromideaqueous potassium iodide chlorine \uf037 \uf033 bromine \uf037 iodine \uf037 [3]  (ii)  write a chemical equation for the reaction between chlorine and aqueous potassium bromide .   ...   [1]  (b)  a sample of vanadium chloride was weighed and dissolved in water. an excess of aqueous  silver\tnitrate,\tacidified\t with\tdilute\tnitric\tacid,\twas\tadded.\ta\tprecipitate\t of\tsilver\tchloride\t was\t formed. the ionic equation for this reaction is shown. ag+(aq)  +  cl \u2013(aq)    agcl (s)   the mass of silver chloride formed was 2.87 g.  (i)  state the colour of the precipitate of silver chloride.   ...   [1]  (ii)  the relative formula mass of silver chloride, agcl, is 143.5.   calculate the number of moles in 2.87 g of agcl. moles of agcl = .. mol  [1]  (iii)  use your answer to (b)(ii)  and the ionic equation to deduce the number of moles of chloride  ions, cl \u2013, that produced 2.87 g of agcl. moles of cl \u2013 = .. mol  [1]  (iv)  the amount of vanadium chloride in the sample was 0.01 moles.   use this and your answer to (b)(iii)  to deduce the whole number ratio of moles of  vanadium chloride : moles of chloride ions.   deduce the formula of vanadium chloride.  moles of vanadium chloride : moles of chloride ions   ... : ...  formula of vanadium chloride  . [2]",
            "11": "11 0620/42/m/j/17 \u00a9 ucles 2017 [turn over  (c)  astatine is at the bottom of group vii. use your knowledge of the properties of the halogens to  (i)  predict the physical state of astatine at room temperature and pressure,   ...   [1]  (ii)  write a chemical equation for the reaction between sodium and astatine.   ...   [2]  (d)  iodine reacts with chlorine. the chemical equation is shown. i2  +  c l 2    2icl   use the bond energies to answer the questions. bond bond energy in kj / mol i\u2013i 151 cl \u2013cl 242 i\u2013cl 208  (i)  calculate the total amount of energy required to break the bonds in 1 mole of i2 and  1 mole of cl 2.  kj  [1]  (ii)  calculate the total amount of energy given out when the bonds in 2 moles of icl are  formed.  kj  [1]  (iii)  use your answers to (d)(i) and (d)(ii)  to calculate the overall energy change for the  reaction. i2  +  c l 2    2icl  kj / mol  [1] [total: 15]",
            "12": "12 0620/42/m/j/17 \u00a9 ucles 2017 6 (a)  an homologous series is a \u2018family\u2019 of organic compounds whose names have the same ending.  (i)  name the homologous series for which the names of the organic compounds end in -ene  and -oic acid .  -ene  ..   [1]  -oic acid      [1]  (ii)  state two characteristics of an homologous series.   .   ...   [2]  (b)  propan-1-ol is a member of the homologous series of alcohols. it reacts in the same way as  ethanol\twith\tacidified\tpotassium\tmanganate( vii) and with carboxylic acids.   name the type of compound that is formed when propan-1-ol is heated with \t \tacidified\tpotassium\tmanganate( vii),     ethanoic acid and a suitable catalyst.   [2]",
            "13": "13 0620/42/m/j/17 \u00a9 ucles 2017 [turn over  (c)  the structure of prop-2-enoic (acrylic) acid is shown. h c hcco2h h  (i)  what would you see if prop-2-enoic acid were added to  aqueous bromine,  ...  a solution of sodium carbonate.  .. [2]  (ii)  prop-2-enoic acid can be polymerised to form poly(acrylic acid).   suggest the type of polymerisation that occurs and draw one repeat unit of the polymer.   type of polymerisation  .   repeat unit [3] [total: 11]",
            "14": "14 0620/42/m/j/17 \u00a9 ucles 2017blank page",
            "15": "15 0620/42/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.blank page",
            "16": "16 0620/42/m/j/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s17_qp_43.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry 0620/43   paper 4 theory (extended) may/june 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib17 06_0620_43/4rp\u00a9 ucles 2017 *5634281822* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/43/m/j/17 \u00a9 ucles 2017 1  six different atoms can be represented as follows. 3 1a32d12 6e13 6g14 7j19 9l  (a)  answer the following questions using atoms from the list. each atom may be used once, more  than once or not at all .   select one atom from the six shown which  (i) has exactly seven protons,   ...   [1]  (ii) has exactly six neutrons,   ...   [1]  (iii) has more protons than neutrons,   ...   [1]  (iv) has the electronic structure [2,5],   ...   [1]  (v) is an atom of an element from group vii of the periodic table,   ...   [1]  (vi) is an atom of a noble gas.   ...   [1]  (b)  two of the six atoms shown are isotopes of each other.  (i)  what is meant by the term isotopes ?   .   ...   [2]  (ii)  which two of the six atoms shown are isotopes of each other?   ...   [1]  (iii)  why do isotopes have identical chemical properties?   .   ...   [1] [total: 10]",
            "3": "3 0620/43/m/j/17 \u00a9 ucles 2017 [turn over 2  cyclopropane is a colourless gas.   cyclopropane reacts with bromine at room temperature. the chemical equation for the reaction is  shown. ch hh hhh c+b rb r cbr br ch hch hch h cyclopropane bromine dibromopropane  (a) (i)  what is the empirical formula of cyclopropane?   ...   [1]  (ii)  what colour change, if any, would you see when cyclopropane is bubbled into aqueous  bromine?  initial colour  . \t final\tcolour\t  .. [2]  (b)  the reaction of cyclopropane with bromine is exothermic.  (i)  complete the energy level diagram for this reaction by \t \u25cf\t\tadding\tthe\tproduct\tof\tthe\treaction, \t \u25cf\t\tlabelling\t the\tenergy\tchange,\t\u2206 h. cyclopropane + bromine energy [2]",
            "4": "4 0620/43/m/j/17 \u00a9 ucles 2017  (ii)  propene also reacts with bromine. +b rb r hhcbr hcbr hch hh cc hhh ch h   use the bond energies in the table to calculate the energy change, \u03b4h, for the reaction. c\u2013h c\u2013c br\u2013br c\u2013br c=c bond energy in kj / mol 412 348 193 285 611 energy change =  kj / mol  [3]  (c)  the boiling point of bromine is 59 \u00b0c and the boiling point of iodine is 184 \u00b0c.   explain why iodine has a higher boiling point than bromine.               ..   [2] [total: 10]",
            "5": "5 0620/43/m/j/17 \u00a9 ucles 2017 [turn over 3  magnesium is a metal.  (a)  describe the structure and bonding in magnesium.            ..   [3]  (b)  why can magnesium conduct electricity when solid?            ..   [2]  (c)  why is magnesium malleable?            ..   [2]",
            "6": "6 0620/43/m/j/17 \u00a9 ucles 2017  (d)\t\tmagnesium\treacts\twith\tsulfur\tto\tform\tthe\tionic\tcompound\tmagnesium\tsulfide,\tmgs.   the diagrams show the electronic structures of atoms of magnesium and sulfur. mg s  (i)\t\tcomplete\t the\tdiagrams\t to\tshow\tthe\telectronic\t structures\t of\tthe\tions\tin\tmagnesium\t sulfide.\t show the charges on the ions. mg s [3]  (ii)\t\tionic\tcompounds,\tsuch\tas\tmagnesium\tsulfide,\tdo\tnot conduct electricity when solid. \t \tmagnesium\tsulfide\tdoes\t not dissolve in water. \t \tmagnesium\tsulfide\t does conduct electricity under certain conditions. \t \tstate\tthe\tconditions\t needed\t for\tmagnesium\t sulfide\tto\tconduct\t electricity.\t explain\twhy\t magnesium\tsulfide\tconducts\telectricity\tunder\tthese\tconditions.   .   .   .   ...   [2] [total: 12]",
            "7": "7 0620/43/m/j/17 \u00a9 ucles 2017 [turn over 4  gasoline is used as a fuel for cars. it is a mixture of hydrocarbons.  (a)  name the raw material from which gasoline is obtained.   ..   [1]  (b)  one of the compounds in gasoline is heptane, c7h16. heptane is a saturated hydrocarbon.  (i)  what is meant by the term saturated hydrocarbon ?  saturated  .   .  hydrocarbon      . [3]  (ii)  to which homologous series does heptane belong?   ...   [1]  (iii)  give two characteristics of an homologous series.  1  ..  2  .. [2]  (iv)  complete the chemical equation for the complete combustion of heptane. c7h16  +  ..o2    ...  +  ... [2]",
            "8": "8 0620/43/m/j/17 \u00a9 ucles 2017  (c)  car engines produce carbon monoxide and oxides of nitrogen.  (i)  name an environmental problem that is caused by the release of oxides of nitrogen into  the air.   ...   [1]  (ii)  explain how carbon monoxide and oxides of nitrogen are formed in car engines.  carbon monoxide     .  oxides of nitrogen  ...   . [3]  (iii)  state one adverse effect of carbon monoxide on human health.   ...   [1]  (iv)  describe and explain how catalytic converters remove oxides of nitrogen from car engine exhaust fumes. you are advised to include a chemical equation in your answer.   .   .   .   .   .   ...   [3]",
            "9": "9 0620/43/m/j/17 \u00a9 ucles 2017 [turn over  (d)  the formula c4h10 represents two structural isomers, a and b. hch hch hc ahh ch hh hch hh cc hc bh hh h h  (i)  name isomer a.   ...   [1]  (ii)  what is meant by the term structural isomers?   .   .   ...   [2]  (iii)  isomer b reacts with chlorine in a substitution reaction.   give the conditions required for the reaction to occur and draw the structures of two  possible products, one of which is organic and one of which is not organic.   conditions  ...   structures of products [3] [total: 23]",
            "10": "10 0620/43/m/j/17 \u00a9 ucles 2017 5  the diagram shows a simple cell. v metal 2 electrolyt emetal 1voltmeter   the simple cell was used with different metals as electrodes. the voltages were recorded in the  table. \t \u25cf\t \tif\tthe\tvoltage\tmeasured\tis\tpositive\tthen\tmetal\t2\tis\tmore\treactive\tthan\tmetal\t1. \t \u25cf\t \tif\tthe\tvoltage\tmeasured\tis\tnegative\tthen\tmetal\t1\tis\tmore\treactive\tthan\tmetal\t2. metal 2 beryllium cobalt nickel silver vanadiummetal 1beryllium 0.0 v \u20131.6 v \u20131.6 v not measured \u20130.7 v cobalt 0.0 v 0.0 v \u20131.1 v 0.9 v nickel 0.0 v \u20131.1 v 0.9 v silver 0.0 v 2.0 v vanadium 0.0 v \t \u25cf\t \tthe\tmore\treactive\tmetal\tis\toxidised. \t \u25cf\t \tthe\tbigger\tthe\tdifference\tin\treactivity\tof\tthe\tmetals,\tthe\tlarger\tthe\treading\ton\tthe\tvoltmeter.  (a)  in a simple cell using nickel and silver, the nickel is oxidised.   (i)\t\tdefine\toxidation  in terms of electrons.   ...   [1]  (ii)  nickel forms ions with a charge of +2.   write an ionic half-equation to show the oxidation of nickel.   ...   [1]  (iii)  what will happen to the mass of the nickel electrode when the nickel is oxidised?   .   ...   [1]",
            "11": "11 0620/43/m/j/17 \u00a9 ucles 2017 [turn over  (b)  use the data in the table to answer the following questions.  (i)  which of the metals in the table is the most reactive?   explain your answer.   .   ...   [2]  (ii)  state which two different metals have the same reactivity.   ...   [1]  (iii)  predict the voltage produced by a simple cell with beryllium as metal 1 and silver as  metal 2.   .   ...   [2]  (c)  describe how the simple cell in the diagram can be used to show that magnesium is more  reactive than beryllium. explain your answer.            ..   [2] [total: 10]",
            "12": "12 0620/43/m/j/17 \u00a9 ucles 2017 6  barium carbonate, baco3, is an insoluble solid.  (a)  when barium carbonate is heated strongly, it undergoes thermal decomposition. one of the  products is barium oxide.  (i)  write a chemical equation for the thermal decomposition of barium carbonate.   ...   [1]  (ii)  suggest the ph of the solution formed when barium oxide is added to water.   ...   [1]  (iii)  barium nitrate decomposes on heating in the same way as magnesium nitrate decomposes.   name the two gaseous products formed when barium nitrate is heated.   .   ...   [2]  (b) aqueous sodium carbonate is added to aqueous barium nitrate.  (i)  write a chemical equation for the reaction of aqueous sodium carbonate with aqueous barium nitrate.   ...   [2]  (ii)  describe how a pure sample of barium carbonate could be obtained from the resulting  mixture.   .   .   .   ...   [3]",
            "13": "13 0620/43/m/j/17 \u00a9 ucles 2017 [turn over  (c)  barium carbonate reacts with dilute hydrochloric acid. baco3  +  2hcl    bacl 2  +  co2  +  h2o   9.85 g of barium carbonate were added to 250 cm3 of 1.00 mol / dm3 hydrochloric acid. this is  an excess of hydrochloric acid.  (i)  calculate how many moles of barium carbonate were used in this experiment. moles of barium carbonate =  mol  [2]  (ii)  deduce how many moles of carbon dioxide were made when all the barium carbonate had  reacted. moles of carbon dioxide =  mol  [1]  (iii)  calculate the volume of carbon dioxide formed in (c)(ii) at room temperature and pressure,  in dm3. volume of carbon dioxide =  dm3  [1]  (iv)  calculate how many moles of hydrochloric acid there were in excess. excess moles of hydrochloric acid  =  mol  [2] [total: 15]",
            "14": "14 0620/43/m/j/17 \u00a9 ucles 2017blank page",
            "15": "15 0620/43/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.blank page",
            "16": "16 0620/43/m/j/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmiu m 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbiu m 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s17_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 7 and 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test may/june 2017  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 8 printed pages. [turn overib17 06_0620_51/3rp\u00a9 ucles 2017 *2045765175* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/51/m/j/17 \u00a9 ucles 2017 1  you are going to investigate the reaction between aqueous sodium thiosulfate and two different  aqueous solutions of potassium iodate labelled solution c and solution d.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a) experiment 1 \t \u25cf\t \tfill\tthe\tburette\tprovided\tup\tto\tthe\t0.0\t cm3 mark with the aqueous sodium thiosulfate. \t \u25cf\t \tuse\ta\tmeasuring\tcylinder\tto\tpour\t20\t cm3 of solution c into a conical flask. \t \u25cf\t \tadd\t10\tcm3\tof\tdilute\tsulfuric\tacid\tinto\tthe\tflask\tand\t1\tg\tof\tpotassium\t iodide.\tswirl\tthe\tflask\t to mix the contents. \t \u25cf\t \tadd\tthe\taqueous\t sodium\tthiosulfate\t slowly\tfrom\tthe\tburette\tto\tthe\tflask,\tand\tswirl\tto\tmix\t thoroughly.  \t \u25cf\t \twhen\tthe\tcontents\tof\tthe\tflask\tare\tpale\t yellow,\tadd\t1\t cm3 of starch solution to the flask. \t \u25cf\t \tcontinue\t to\tadd\taqueous\t sodium\tthiosulfate\t slowly\tto\tthe\tflask\tuntil\tthe\tsolution\tjust\tturns\t colourless. \t \u25cf\t \trecord\tthe\tburette\treadings\tin\tthe\ttable.  (b) experiment 2 \t \u25cf\t \tempty\tthe\tconical\tflask\tand\trinse\tit\twith\t distilled\twater. \t \u25cf\t \trepeat\texperiment\t1,\tusing\tsolution\t d instead of solution c. \t \u25cf\t \trecord\tthe\tburette\treadings\tin\tthe\ttable \tand\tcomplete\tthe\ttable. experiment\t1 experiment\t2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 [4]  (c)\t\tdescribe\t the\tappearance\t of\tthe\tsolution\t in\tthe\tconical\tflask\tbefore\tadding\tthe\taqueous\t   sodium thiosulfate.   .. \t\t[1]  (d)\t\tbefore\tthe\taddition\t of\tthe\tstarch\tsolution,\t describe\t the\tchanges\t to\tthe\tcolour\tof\tthe\tsolution\tin\t the\tconical\tflask\tas\tthe\taqueous\tsodium\tthiosulfate\tis\tadded.   .. \t\t[1]  (e)\t\twhat\tcolour\tchange\tis\tobserved\tin\tthe\tconical\tflask \twhen\tthe\tstarch\tsolution\tis\tadded?   from .. to  .. \t\t[1]",
            "3": "3 0620/51/m/j/17 \u00a9 ucles 2017 [turn over  (f) (i)\t \twhich\tsolution\t of\tpotassium\t iodate,\tsolution\t c or solution d,\tis\tthe\tmore\tconcentrated?\t explain\tyour\tanswer.   .   ... \t\t[2]  (ii)\t\thow\tmany\ttimes\tmore\tconcentrated\tis\tthis\tsolution\tof\tpotassium\tiodate?   ... \t\t[1]  (g)  predict the volume of aqueous sodium thiosulfate which would be needed to react completely  with\t30\tcm3 of solution d.      .. \t\t[2]  (h) (i)\t \tstate\ttwo sources of error in the experiments. \t 1\t .. \t 2\t .. [2]  (ii)\t\tsuggest\ttwo improvements to reduce the sources of error in (h)(i). \t 1\t .. \t 2\t .. [2] [total:\t16]",
            "4": "4 0620/51/m/j/17 \u00a9 ucles 2017 2  you are provided with two solids e and f. \t\tcarry\tout\tthe\tfollowing\ttests\ton\teach\tsolid,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.  tests on solid e  (a)  describe the appearance of solid e.   .. \t\t[1]  (b)  place a small amount of solid e in a hard glass test-tube. heat the solid gently then strongly. \t \trecord\tyour\tobservations.      .. \t\t[2]  (c) (i)  place a small amount of solid e\t in\ta\ttest-tube\t and\tadd\tabout\t2\tcm3 of dilute sulfuric acid.  test the gas given off. \t \trecord\tyour\tobservations.   .   .   ...   [3]  (ii)  now gradually add an excess of aqueous ammonia to the mixture in the test-tube. \t \trecord\tyour\tobservations.   .   .   ...   [3]  (d)\t\tcarry\tout\ta\tflame\ttest\ton\tsolid\te. \t \trecord\tyour\tobservations.   .. \t\t[1]  (e)  identify solid e.   .. \t\t[2]",
            "5": "5 0620/51/m/j/17 \u00a9 ucles 2017 [turn over  tests on solid f  (f)  describe the appearance of solid f.   .. \t\t[1] \t\tadd\tabout\t4\tcm3 of distilled water to about half of solid f in a test-tube and shake the test-tube to  dissolve solid f.   divide the solution into two equal portions in two test-tubes and carry out the following tests.  (g) (i)\t \tto\tthe\tfirst\tportion\tof\tthe\tsolution,\tadd\tan\texcess\tof\taqueous\tsodium\thydroxide. \t \trecord\tyour\tobservations.   ... \t\t[1]  (ii)\t\tto\tthe\tsecond\tportion\tof\tthe\tsolution,\t add\tabout\t1\tcm3 of dilute nitric acid and aqueous  silver nitrate. \t \trecord\tyour\tobservations.   ... \t\t[1]  (h)\t\tcarry\tout\ta\tflame\ttest\ton\tsolid\tf. \t \trecord\tyour\tobservations.   .. \t\t[1]  (i)  identify solid f.   .. \t\t[2] [total:\t18]",
            "6": "6 0620/51/m/j/17 \u00a9 ucles 2017 3\t\ta\tsample\tof\tfurniture\tcleaner\tcontains\taqueous\tsodium\tchloride,\taqueous\tammonia\tand\tsand.  (a)  give a test to show the presence of ammonia in the mixture.   .. \t\t[1]  (b)  plan experiments to obtain a sample of  (i)\t\tpure\twater\tfrom\tthe\tmixture,\t ...   .   .   ... \t\t[2]  (ii)  pure sand from the mixture.     .   .   .   ...   [3] [total:\t6]",
            "7": "7 0620/51/m/j/17 \u00a9 ucles 2017notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "8": "8 0620/51/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_s17_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 7 and 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry   0620/52   paper 5 practical test may/june 2017  1 hour 15 minutes candidates answer on the question paper.additional materials: as listed in the con \ufb01 dential instructionscambridge international examinations cambridge international general certi \ufb01 cate of secondary education this document consists of 8 printed pages. [turn overib17 06_0620_52/fp \u00a9 ucles 2017 \uf02a\uf030\uf033\uf038\uf030\uf035\uf035\uf032\uf035\uf032\uf030\uf02a the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.for examiner\u2019s use total",
            "2": "2 0620/52/m/j/17 \u00a9 ucles 20171  you are going to investigate the reaction between aqueous potassium manganate( vii), solution a,  and two solutions of iron( ii) sulfate, solution b and solution c, of different concentrations.  read all the instructions carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a) experiment 1  \u25cf  fill the burette with solution a to the 0.0 cm3 mark.  \u25cf  use a measuring cylinder to pour 25 cm3 of solution b into the conical flask.  \u25cf  add 1 cm3 of solution a from the burette to the flask, while swirling the flask.  \u25cf  continue to add solution a to the flask until the mixture just turns permanently pink.  \u25cf  record the burette reading in the table and complete the table.  \u25cf  pour away the contents of the flask and rinse the flask with distilled water. \ufb01 nal burette reading / cm3 initial burette reading / cm3 difference / cm3 [2]  (b)  experiment 2  \u25cf  repeat experiment 1 using 25 cm3 of solution c instead of solution b.  \u25cf  record the burette readings in the table and complete the table. \ufb01 nal burette reading / cm3 initial burette reading / cm3 difference / cm3 [2]",
            "3": "3 0620/52/m/j/17 \u00a9 ucles 2017 [turn over (c) (i)   how does the colour of solution a change when it is \ufb01 rst added to the conical \ufb02 ask?  from ... to  . .  [1]  (ii)  why is an indicator not added to the conical \ufb02 ask?   . ..  [1]  (d) (i)   which solution of iron( ii) sulfate, solution b or solution c, is the more concentrated?  explain your answer.   .    . ..  [2]  (ii)  how many times more concentrated is this solution of iron( ii) sulfate?   . ..  [1]  (e) (i)   if experiment 2 were repeated using 50 cm3 of solution c, what volume of solution a would  be needed? explain your answer.   .    . ..  [2]  (ii)  suggest a practical problem that using 50 cm3 of solution c in this investigation would  cause. suggest a possible solution to the problem.  problem  . ..  solution   ... [2]  (f)  give one advantage and one disadvantage of using a measuring cylinder instead of a  25 cm3 pipette for solution b.  advantage  ... ...  disadvantage   . [2] [total: 15]",
            "4": "4 0620/52/m/j/17 \u00a9 ucles 20172  you are provided with two solids, e and f, which are both salts.   carry out the following tests on each solid, recording all of your observations at each stage.   tests on solid e  (a)  carry out a \ufb02 ame test on a sample of solid e.   record your observations.   ... ...  [1]  (b)  pour about 10 cm3 of distilled water into a boiling tube. measure the initial temperature of the  water and record it in the table. add the rest of solid e to the boiling tube and shake the boiling  tube to dissolve solid e. measure and record the temperature of the solution after 1 minute.  complete the table. temperature of the solution after 1 minute / \uf0b0c initial temperature of the water / \uf0b0c temperature difference / \uf0b0c [2]   divide the solution into three equal portions in three test-tubes and carry out the following tests.  (c)  to the \ufb01 rst portion of the solution, add about 2 cm3 of dilute hydrochloric acid.    test the gas given off with a small strip of \ufb01 lter paper that has been dipped into  acidi \ufb01 ed aqueous potassium manganate( vii).   record your observations.   ... .   ... ...  [3]  (d)  to the second portion of the solution, add an excess of aqueous sodium hydroxide.   record your observations.   ... ...  [1]  (e) (i)   mix about 2 cm3 of aqueous copper( ii) sulfate and 2 cm3 of aqueous potassium iodide. add  a small amount of starch solution to the mixture. leave the solution to stand for 5 minutes.   record your observations.   .    . ..  [2]  (ii)  now add the third portion of the solution of e to the mixture in (e)(i) .   record your observations.   .    . ..  [2]",
            "5": "5 0620/52/m/j/17 \u00a9 ucles 2017 [turn over (f)  what conclusions can you draw about solid e?   ... ...  [2]  tests on solid f  (g)  carry out a \ufb02 ame test on a sample of solid f.   record your observations.   ... ...  [1]   add the rest of solid f to about 5 cm3 of distilled water in a test-tube. shake the mixture to dissolve  solid f. divide the solution into two equal portions in two test-tubes.  (h)  to the \ufb01 rst portion of the solution, add about 1 cm3 of dilute nitric acid and aqueous silver nitrate.   record your observations.   ... ...  [2]  (i)  to the second portion of the solution, add excess aqueous sodium hydroxide.   record your observations.   ... ...  [1]  (j)  identify solid f.   ... ...  [2] [total: 19]",
            "6": "6 0620/52/m/j/17 \u00a9 ucles 20173  calcium carbonate and kaolinite are both white solids found in sedimentary rocks.   calcium carbonate reacts with dilute hydrochloric acid to form aqueous calcium chloride. kaolinite  does not react with dilute acids.   you are provided with a mixture of calcium carbonate and kaolinite and access to  dilute hydrochloric acid.   plan an experiment to determine the percentage by mass of calcium carbonate in the mixture.   ...    ...    ...    ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 6]",
            "7": "7 0620/52/m/j/17 \u00a9 ucles 2017notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous barium  nitratewhite ppt. sul\ufb01 te (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn  acidi \ufb01 ed aqueous potassium  manganate( vii) from purple to  colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+) ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "8": "8 0620/52/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion \ufb02 ame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2) turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidi \ufb01 ed aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_s17_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 7 and 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test may/june 2017  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 8 printed pages. [turn overib17 06_0620_53/3rp\u00a9 ucles 2017 *1598429303* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/53/m/j/17 \u00a9 ucles 2017 1  you are going to investigate the rate of reaction between magnesium ribbon and two different  solutions of dilute sulfuric acid, solution g and solution h. the acid is in excess in both experiments.   read all the instructions carefully before starting the experiments.   instructions you are going to carry out two experiments.  (a)  experiment 1 \t \u25cf\t \tset\tup\tthe\tapparatus\tas\tshown\tin\tthe\tdiagram. trough waterconical flaskbungrubber connector inverted 100  cm3 measuring cylinderclamp \t \u25cf\t \tremove\t the\tbung\tfrom\tthe\tconical\tflask\tand\tplace\t one piece of magnesium ribbon into the  conical\tflask. \t \u25cf\t \tuse\tanother\tmeasuring\t cylinder\tto\tmeasure\t 50\tcm3 of solution g. pour solution g into the  flask\tand\treplace\tthe\tbung\tfirmly.\timmediately\t start\tthe\ttimer.\tmeasure\t the\ttotal\tvolume\tof\t gas\tcollected \tin\tthe\tmeasuring\t cylinder\tevery\t20\tseconds\t for\t180\tseconds\t (3\tminutes)\t or\t until\t100\t cm3\tof\tgas\thave\tbeen\tcollected.\trecord\tyour\tresults\tin\tthe\ttable. time / s 020406080100120140160180 volume of gas / cm3 [2] \t \u25cf\t \tempty\tthe\tflask\tand\trinse\tit\twith\tdistilled \twater.  (b) experiment 2 \t \u25cf\t \trepeat\texperiment\t1\tusing\t50\t cm3 of solution h instead of solution g. \t \u25cf\t \tmeasure\t the\ttotal\tvolume\tof\tgas\tcollected\t in\tthe\tmeasuring\t cylinder\tevery\t20\tseconds\t for\t 180\tseconds\t (3\tminutes)\t or\tuntil\t100\tcm3\tof\tgas\thave\tbeen\tcollected.\t record\tyour\tresults\t in the table. time / s 020406080100120140160180 volume of gas / cm3 [2]",
            "3": "3 0620/53/m/j/17 \u00a9 ucles 2017 [turn over  (c)\t\tplot\tthe\tresults\tfor\texperiments\t1\tand\t2\ton\tthe\tgrid\t and\tdraw\t two smooth line graphs.   clearly label your graphs. 02 04 06 0 time  / s80 100 120 140 160 180 200100 90 80 70 60 50 40 30 20 10 0volume of gas  / cm3 [4]  (d)\t\twhich\texperiment \thad\tthe\tfaster\trate\tof\treaction?\t suggest\t a\treason\twhy\tthe\trate\twas\tfaster\tin\t this experiment.      ..   [2]",
            "4": "4 0620/53/m/j/17 \u00a9 ucles 2017  (e)  the average rate of this reaction can be calculated using the equation shown. average rate = volume of gas / cm3 time\ttaken\t /\ts \t \tfor\texperiment\t 1,\tcalculate\t the\taverage\t rate\tof\treaction\t for\tthe\tfirst\t30\tseconds\t of\tthe\treaction.\t include\tthe\tunits. rate =  units =  [3]  (f)  why, eventually, will no more gas be produced?   .. \t\t[1]  (g)\t\tsuggest\t the\teffect\ton\tthe\trate\tof\treaction\t of\tusing\tthe\tsame\tmass\tof\tmagnesium\t powder\t instead\tof\tmagnesium\tribbon.\texplain\tyour\tanswer.         ..   [2]  (h)  give one advantage and one disadvantage of using a measuring cylinder to measure the  volumes of solution g and solution h.  advantage  ..  disadvantage  . [2]  (i)\t\tsuggest\tone improvement to these experiments.      .. \t\t[1] [total:\t19]",
            "5": "5 0620/53/m/j/17 \u00a9 ucles 2017 [turn over 2  you are provided with two substances, solid j and solution k.   carry out the following tests on each substance, recording all of your observations at each stage.  tests on solid j  (a)  describe the appearance of solid j.   .. \t\t[1]  (b) (i)\t \tuse\ta\tspatula\tto\tplace\thalf\tof\tsolid\t j into a boiling tube.   add about 2 cm3 of dilute hydrochloric acid to solid j. heat the mixture.   test the gas given off with damp litmus paper. \t \trecord\tyour\tobservations.   ... \t\t[1]  (ii)  allow the mixture to settle, pour off the liquid and add an excess of aqueous sodium hydroxide  to the liquid. \t \trecord\tyour\tobservations.   ...   [2]  (c)  name the gas given off in (b)(i).   .. \t\t[1]   keep the rest of solid j for the test in (g).   tests on solution k   divide solution k into four equal portions in four test-tubes.  (d)\t\tadd\ta\tsmall\tspatula\tmeasure\t of\tiron(ii)\tsulfate\tcrystals\t to\tthe\tfirst\tportion\tof\tthe\tsolution.\t shake\tthe\tmixture\tand\tadd\taqueous\tsodium\thydroxide\tto\tthe\tmixture. \t \trecord\tyour\tobservations.      ..   [3]  (e)  add a few drops of dilute sulfuric acid to the second portion of the solution followed by about  1\tcm3\tof\taqueous\t potassium\t iodide.\tshake\tthe\tmixture.\t add\ta\tfew\tdrops\tof\tstarch\tsolution\t to\t the mixture. \t \trecord\tyour\tobservations.      ..   [2]",
            "6": "6 0620/53/m/j/17 \u00a9 ucles 2017  (f)  add a few drops of dilute sulfuric acid to the third portion of the solution. then add a few drops  of\tpotassium\tmanganate( vii)\tsolution. \t \trecord\tyour\tobservations.   .. \t\t[1]  (g)  add the rest of solid j to the fourth portion of the solution. test the gas given off with a splint. \t \trecord\tyour\tobservations.      ..   [3]  (h)  name the gas given off in (g).   .. \t\t[1] [total:\t15] 3  cassiterite is a naturally occurring form of tin oxide.   describe how you would \t \u25cf\t \tobtain\ta\tsample\tof\ttin\tfrom\ta\tlarge\tlump\tof\tcassiterite\tin\tthe\tlaboratory, \t \u25cf\t \tdetermine\tthe\tpercentage\tby\tmass\tof\ttin\tpresent\tin\tcassiterite.   tin is similar in reactivity to iron.   your answer should include any apparatus and chemicals used and the conditions required.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "7": "7 0620/53/m/j/17 \u00a9 ucles 2017notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "8": "8 0620/53/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp, red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_s17_qp_61.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib17 06_0620_61/fp \u00a9 ucles 2017 *3090986058* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical may/june 2017  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/61/m/j/17 \u00a9 ucles 2017 1  a student prepared strontium nitrate crystals.   the diagram shows some of the stages in this preparation. strontium carbonate added stage 1 stage 2 stage 3dilute acid unreacted solidstrontium nitrate solution .  (a) (i)  complete the box to identify the apparatus. [1]  (ii)  what is used to add the strontium carbonate to the acid in stage 1?   ...   [1]  (iii)  name the dilute acid used.   ...   [1]  (iv)  give one expected observation in stage 2.   ...   [1]  (b)  why is heat not necessary in stage 2?   ..   [1]  (c)  which of the reactants is in excess? explain your answer.      ..   [2]  (d)  describe how crystals of strontium nitrate could be obtained from the mixture in stage 3.         ..   [3] [total: 10]",
            "3": "3 0620/61/m/j/17 \u00a9 ucles 2017 [turn over 2  a student investigated the reaction between aqueous sodium thiosulfate and two different aqueous  solutions of potassium iodate labelled solution c and solution d.   two experiments were carried out.  experiment 1 \t \u25cf\t \ta\tburette\twas\tfilled\twith\taqueous\t sodium\tthiosulfate.\t the\tinitial\tburette\treading\twas\trecorded. \t \u25cf\t \tusing\ta\tmeasuring\t cylinder,\t 20\tcm3 of solution c\t were\tpoured\tinto\ta\tconical\tflask.\t10\tcm3 of  dilute\tsulfuric\tacid\tand\t1\tg\tof\tpotassium\t iodide\twere\tadded\tto\tthe\tflask\tto\tform\ta\tsolution\t of\t iodine.\tthe\tflask\twas\tswirled\tto\tmix\tthe\tcontents. \t \u25cf\t \taqueous\t sodium\tthiosulfate\t was\tslowly\tadded\tfrom\tthe\tburette\tto\tthe\tflask\tand\tswirled\tto\tmix\t thoroughly. \t \u25cf\t \twhen\tthe\tcontents\t of\tthe\tflask\tturned\tpale\tyellow,\tstarch\tsolution\twas\tadded\tand\tthe\tsolution\t turned\tblue-black. \t \u25cf\t \tmore\taqueous\t sodium\tthiosulfate\t was\tthen\tadded\tslowly\tto\tthe\tflask\tuntil\tthe\tsolution\t just\t turned\tcolourless.\t the\tfinal\tburette\treading\twas\trecorded.  (a)\t\tuse\tthe\tburette\tdiagrams\tto\trecord\tthe\treadings\tin\t the\ttable\tand\tcomplete\tthe\ttable. 4 5 6 initial readin g37 38 39 final reading final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 [2]",
            "4": "4 0620/61/m/j/17 \u00a9 ucles 2017   experiment 2 \t \u25cf\t \tthe\tconical\tflask\twas\temptied\tand\trinsed\twith\tdistilled\twater. \t \u25cf\t \texperiment\t1\twas\trepeated\tusing\tsolution\t d instead of solution c.  (b)\t\tuse\tthe\tburette\tdiagrams\tto\trecord\tthe\treadings\tin\tthe\ttable\tand\tcomplete\tthe\ttable. 20 21 22 initial reading3 4 5 final reading final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 [2]  (c) (i)\t\twhich\tsolution\t of\tpotassium\t iodate,\tsolution\t c or solution d,\tis\tthe\tmore\tconcentrated?\t explain your answer.   .   ...   [2]  (ii)  how many times more concentrated is this solution of potassium iodate?   ...   [1]  (d)  predict the volume of aqueous sodium thiosulfate which would be needed to react completely  with 30 cm3 of solution d.      ..   [2]",
            "5": "5 0620/61/m/j/17 \u00a9 ucles 2017 [turn over  (e) (i)  state two sources of error in the experiments.  1.  .  2.  . [2]  (ii)  suggest two improvements to reduce the sources of error in (e)(i).  1.  .  2.  . [2] [total: 13]",
            "6": "6 0620/61/m/j/17 \u00a9 ucles 2017 3\t\ttwo\tsolids,\t e and f,\t were\tanalysed.\t solid\t f was potassium iodide. tests were carried out on each  solid. some of the observations on solid e are shown. tests on solid e observations appearance of solid e. green solid test 1 solid e was heated gently then strongly. the\tsolid\tturned\tblack test 2 dilute sulfuric acid was added to solid e. the gas given off was tested. excess aqueous ammonia was then added to  the mixture in the test-tube.rapid effervescence limewater\tturned\tmilky a\tpale\tblue\tprecipitate\tformed,\twhich\tthen dissolved\tto\tform\ta\tdark\tblue\tsolution test 3 a\tflame\ttest\twas\tcarried\tout\ton\tsolid\t e. blue-green colour  (a)  test 1 states that the solid should be heated gently then strongly. \t \tin\tterms\tof\tsafety,\texplain\twhy\tit\tis\tnecessary\tto\theat\tgently\tat\tfirst.      ..   [1]  (b)  identify the gas given off in test 2.   ..   [1]  (c)  identify solid e.   ..   [2]",
            "7": "7 0620/61/m/j/17 \u00a9 ucles 2017 [turn over   tests on solid f   complete the expected observations.  (d)  describe the appearance of solid f.   ..   [1]   distilled water was added to solid f\tin\ta\ttest-tube\tand\tshaken\tto\tdissolve\tsolid\t f.  (e) (i)\t \tto\tthe\tfirst\tportion\tof\tthe\tsolution,\tan\texcess\tof\taqueous\tsodium\thydroxide\twas\tadded.  observations  .   [1]  (ii)\t\tto\tthe\tsecond\tportion\tof\tthe\tsolution,\t dilute\tnitric\tacid\tand\taqueous\t silver\tnitrate\twere\t added.  observations  .   [2]  (f)\t\ta\tflame\ttest\twas\tcarried\tout\ton\tsolid\t f.  observations     [1]  (g)\t\tdescribe\thow\tyou\twould\tcarry\tout\ta\tflame\ttest.         ..   [2] [total: 11]",
            "8": "8 0620/61/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 4\t\ta\tsample\tof\tfurniture\tcleaner\tcontains\taqueous\tsodium\tchloride,\taqueous\tammonia\tand\tsand.  (a)  give a test to show the presence of ammonia in the mixture.   ..   [1]  (b)  plan an investigation to obtain a sample of  (i)\t\tpure\twater\tfrom\tthe\tmixture,\t ...   .   .   ...   [2]  (ii)  pure sand from the mixture.     .   .   .   ...   [3] [total: 6]"
        },
        "0620_s17_qp_62.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib17 06_0620_62/fp \u00a9 ucles 2017 \uf02a\uf037\uf039\uf039\uf031\uf036\uf038\uf031\uf032\uf030\uf039\uf02a read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction \ufb02 uid. do not  write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry   0620/62   paper 6 alternative to practical may/june 2017  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certi \ufb01 cate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certi \ufb01 cate.",
            "2": "2 0620/62/m/j/17 \u00a9 ucles 20171  a student investigated the rate of reaction between an excess of dilute hydrochloric acid and  magnesium ribbon. the apparatus is shown. watermagnesium ribbon dilutehydrochloricacid. .   two experiments were carried out. the temperature was the same in each case.  (a)  complete the boxes to identify the apparatus. [2]  (b)  give one observation expected during this reaction.   ... ...  [1]   graphs were drawn from the results for each experiment as shown. volume of gas  / cm3experiment 1 experiment 2100 908070605040302010 0  (c)  label the x-axis of the graph. [2]",
            "3": "3 0620/62/m/j/17 \u00a9 ucles 2017 [turn over (d) (i)   give the volumes of gas at which the two graphs level out and compare these values.   .    . ..  [2]  (ii)  suggest why the graphs level out at different volumes.   . ..  [1]  (iii)  the graph has been drawn again.   draw the curve expected if experiment 1 were repeated using the same mass of  magnesium powder instead of magnesium ribbon. volume of gas  / cm3experiment 1 experiment 2100 908070605040302010 0 [2] [total: 10]",
            "4": "4 0620/62/m/j/17 \u00a9 ucles 20172  a student investigated the reaction between aqueous potassium manganate( vii), solution a, and  two solutions of iron( ii) sulfate, solution b and solution c, of different concentrations.   two experiments were carried out.  experiment 1  \u25cf  a burette was \ufb01 lled with solution a to the 0.0 cm3 mark.  \u25cf  a measuring cylinder was used to pour 25 cm3 of solution b into a conical \ufb02 ask.  \u25cf  solution a was added to the \ufb02 ask, while the \ufb02 ask was swirled, until the mixture just turned  permanently pink. the burette reading was recorded.  (a)  use the burette diagram to record the reading in the table and complete the table. 12 1314 final reading \ufb01 nal burette reading / cm3 initial burette reading / cm3 difference / cm3 [2]  experiment 2  \u25cf  experiment 1 was repeated using 25 cm3 of solution c instead of solution b. in experiment 2  the burette was not \ufb01 lled to the 0.0 cm3 mark.  (b)  use the burette diagrams to record the readings in the table and complete the table. 2 34 initial reading404142 final reading \ufb01 nal burette reading / cm3 initial burette reading / cm3 difference / cm3 [2]",
            "5": "5 0620/62/m/j/17 \u00a9 ucles 2017 [turn over (c)  why is an indicator not added to the conical \ufb02 ask?   ... ...  [1]  (d) (i)   which solution of iron( ii) sulfate, solution b or solution c, is the more concentrated?  explain your answer.   .    . ..  [2]  (ii)  how many times more concentrated is this solution of iron( ii) sulfate?   . ..  [1]  (e) (i)   if experiment 2 were repeated using 50 cm3 of solution c, what volume of solution a would  be needed? explain your answer.   .    . ..  [2]  (ii)  suggest a practical problem that using 50 cm3 of solution c in this investigation would  cause. suggest a practical solution to the problem.  problem  . ..  solution   ... [2]  (f)  give one advantage and one disadvantage of using a measuring cylinder instead of a  25 cm3 pipette for solution b.  advantage  ... ...  disadvantage   . [2]  (g)  how would the results be improved by taking repeated measurements?   ... .   ... ...  [1] [total: 15]",
            "6": "6 0620/62/m/j/17 \u00a9 ucles 20173  two solids, e and f, which are both salts, were analysed. solid f was lithium chloride.   tests were carried out on each solid.   some of the tests and observations are shown.  tests on solid e tests on solid e observations test 1 a \ufb02 ame test was carried out on solid e. yellow colour  test 2   10 cm3 of distilled water were poured into a boiling tube. the initial temperature of the water was  measured.   solid e was added to the boiling tube and the boiling tube was shaken to dissolve solid e. the  temperature of the solution was measured after 1 minute.  (a)   use the thermometer diagrams in the table to record the temperatures and complete the table. temperature of  the solution after  1 minute / \uf0b0c20 15 10 initial temperature  of the water / \uf0b0c30 25 20 temperature difference / \uf0b0c  [2]   the solution was divided into two equal portions in two test-tubes and the following tests carried  out. tests on solid e observations test 3 dilute hydrochloric acid was added to the \ufb01 rst  portion of the solution. the gas given off was tested with \ufb01 lter paper dipped into acidi \ufb01 ed  aqueous potassium manganate( vii).\ufb01 lter paper turned from purple to colourless test 4 an excess of aqueous sodium hydroxide was  added to the second portion of the solution.no change",
            "7": "7 0620/62/m/j/17 \u00a9 ucles 2017 [turn over (b)  what does the temperature change tell you about the process occurring in test 2 ?   ... ...  [1]  (c)  name the gas given off in test 3 .   ... ...  [1]  (d)  identify solid e.   ... ...  [2]  tests on solid f   complete the expected observations.  (e)  a \ufb02 ame test was carried out on solid f.  observations     [1]   solid f was added to distilled water in a test-tube and the test-tube shaken to dissolve solid f.  (f)  dilute nitric acid and aqueous silver nitrate were added to the solution.  observations     [2] [total: 9]",
            "8": "8 0620/62/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly  been included, the publisher will  be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to do wnload at www.cie.org.uk after  the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.4  calcium carbonate and kaolinite are both white solids found in sedimentary rocks.   calcium carbonate reacts with dilute hydrochloric acid to form aqueous calcium chloride. kaolinite  does not react with dilute acids.   you are provided with a mixture of calcium carbonate and kaolinite and access to  dilute hydrochloric acid.   plan an experiment to determine the percentage by mass of calcium carbonate in the mixture.   ...    ...    ...    ...    ...    ...    ...    ...    ...    ... ..  [6] [total: 6]"
        },
        "0620_s17_qp_63.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib17 06_0620_63/3rp \u00a9 ucles 2017 *6879205020* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical may/june 2017  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/63/m/j/17 \u00a9 ucles 2017 1  a mixture of alcohols can be separated by fractional distillation. the apparatus shown was used to  separate ethanol from the mixture. mixture of alcoholswater .  (a) (i)  complete the box to identify the apparatus. [1]  (ii)  indicate with an arrow where heat is applied. [1]   (b)  what is the purpose of the water?      ..   [2]  (c)  why is the thermometer bulb placed as shown and not in the mixture of alcohols?      ..   [1]  (d)  use the letter e to indicate on the diagram where ethanol would collect. [1]  (e) (i)  suggest a simple chemical test to show that the liquid collected is ethanol and not water.   ...   [1]  (ii)  give a physical test to identify pure ethanol.   ...   [1] [total: 8]",
            "3": "3 0620/63/m/j/17 \u00a9 ucles 2017 [turn over 2  a student investigated the rate of reaction between magnesium ribbon and two different solutions  of dilute sulfuric acid, solution g and solution h. the acid was in excess in both experiments.   two experiments were carried out.   experiment 1 \t \u25cf\t \tthe\tapparatus\twas\tset\tup\tas\tshown\tin\tthe\tdiagram. trough waterconical flaskbungrubber connector inverted 100  cm3 measuring cylinderclamp \t \u25cf\t \tusing\ta\tmeasuring \tcylinder,\t 50\tcm3 of solution g\t were\tpoured\tinto\tthe\tconical\tflask.\ta\tpiece\tof\t magnesium\tribbon\twas\tadded\tto\tthe\tconical\tflask\tand\tthe\tbung\treplaced. \t \u25cf\t \tthe\ttimer\twas\tstarted\timmediately\t and\tthe\ttotal\tvolume\tof\tgas\tcollected\t in\tthe\tmeasuring\t cylinder\twas\tmeasured\tevery\t20\tseconds\tfor\t180\tseconds\t(3\tminutes).   experiment 2 \t \u25cf\t \texperiment\t1\twas\trepeated\tusing\t50\t cm3 of solution h instead of solution g.",
            "4": "4 0620/63/m/j/17 \u00a9 ucles 2017  (a)\t\tuse\tthe\tmeasuring\tcylinder\tdiagrams\tto\trecord\tthe\t volumes\tof\tgas\tcollected\tin\texperiment\t1. 0time  / smeasuring cylinder diagramvolume of gas  / cm3volume of gas  / cm3 2020 15 10 10 5 0 4030 25 20 6045 40 35 8050 4540 100605550 1207570 65 14085 8075 16095908595 90851800 8 14 21 27 3339 45 50 55experiment 1e xperiment 2 [3]",
            "5": "5 0620/63/m/j/17 \u00a9 ucles 2017 [turn over  (b)\t\tplot\tthe\tresults\tfor\texperiments\t1\tand\t2\ton\tthe\tgrid\t and\tdraw\t two smooth line graphs.   clearly label your graphs. 02 04 06 0 time  / s80 100 120 140 160 180 200100 90 80 7060 50 40 30 20 10 0volume of gas  / cm3 [4]  (c)  which experiment had the faster rate of reaction? suggest a reason why the rate was faster in  this experiment.      ..   [2]",
            "6": "6 0620/63/m/j/17 \u00a9 ucles 2017  (d)  the average rate of this reaction can be calculated using the equation shown. average rate = volume of gas / cm3 time\ttaken\t /\ts \t \tfor\texperiment\t 1,\tcalculate\t the\taverage\t rate\tof\treaction\t for\tthe\tfirst\t30\tseconds\t of\tthe\treaction.\t include the units. rate =  units =  [3]  (e)  why, eventually, will no more gas be produced?   ..   [1]  (f)  suggest the effect on the rate of reaction of using the same mass of magnesium powder  instead\tof\tmagnesium\tribbon.\texplain\tyour\tanswer.         ..   [2]  (g)  give one advantage and one disadvantage of using a measuring cylinder to measure the  volumes of solution g and solution h.  advantage  ..  disadvantage  . [2]  (h)  suggest one improvement to these experiments.      ..   [1] [total: 18]",
            "7": "7 0620/63/m/j/17 \u00a9 ucles 2017 [turn over 3  two substances, solid j and solution k, were analysed. solution k was hydrogen peroxide.   tests on each substance were carried out. the observations are shown. tests observations tests on solid j appearance of solid j. black\tsolid test 1 dilute hydrochloric acid was added to solid j.  the mixture was heated and the gas given off  was tested with damp litmus paper.blue litmus turned white tests on solution k solution k was divided into two equal portions  in two test-tubes. test 2 iron( ii)\tsulfate\tcrystals\twere\tadded\tto\tthe\tfirst\t portion\tof\tthe\tsolution.\t the\tmixture\twas\tshaken\t and aqueous sodium hydroxide was added to  the mixture.red-brown precipitate formed test 3 solid j was added to the second portion of the  solution. the gas given off was tested with a splint.glowing splint relit solid j was unchanged  (a)  name the gas given off in test 1.   ..   [1]  (b) (i)  name the precipitate formed in test 2.   ...   [2]  (ii)  a new test 2\twas\tcarried\tout.\tiron( ii)\tsulfate\tcrystals\twere\tadded\tto\twater, the mixture   was\tshaken\tand\tthen\taqueous\tsodium\thydroxide\twas\tadded.   what would be observed?   ...   [2]",
            "8": "8 0620/63/m/j/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (c)  name the gas given off in test 3.   ..   [1]  (d)  what conclusions can you draw about solid j?      ..   [2] [total: 8] 4  cassiterite is a naturally occurring form of tin oxide.   describe how you would \t \u25cf\t \tobtain\ta\tsample\tof\ttin\tfrom\ta\tlarge\tlump\tof\tcassiterite\tin\tthe\tlaboratory, \t \u25cf\t \tdetermine\tthe\tpercentage\tby\tmass\tof\ttin\tpresent\tin\tcassiterite.   tin is similar in reactivity to iron.   your answer should include any apparatus and chemicals used and the conditions required.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]"
        },
        "0620_w17_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 15 printed pages and 1 blank page.  ib17 11_0620_11/4rp  \u00a9 ucles 2017 [turn over     *1330880521 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice (core)  october/november 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/11/o/n/17  1 the diagram shows how the arrangement of particles changes when a substance changes state.        which change of state is shown?  a boiling  b condensation  c evaporation  d sublimation     2 which method can be used to separate a mixture of salt and water to obtain both  parts of the  mixture?  a crystallisation  b distillation  c evaporation  d filtration     3 a student put 25.0  cm3 of dilute hydrochloric acid into a conical flask.    the student added 2.5  g of solid sodium carbonate and measured the change in temperature of  the mixture.    which apparatus does the student need to use to obtain the most accurate results?  a balance, measuring cylinder, thermometer  b balance, pipette, stopwatch  c balance, pipette, thermometer  d burette, pipette, thermometer     4 propanone, c 3h6o, is a liquid at room temperature.    what is the boiling point of pure propanone?  a \u201361  \u00b0c to \u201351  \u00b0c  b \u201356  \u00b0c  c 51  \u00b0c to 61  \u00b0c  d 56  \u00b0c     ",
            "3": "3  \u00a9 ucles 2017 0620/11/o/n/17 [turn over  5 which statement about the boxes p, q and r is correct?    p q r     a box p contains two compounds and box r contains two elements.  b box p contains two elements and  box q contains a mixture.  c box p contains two elements and box q contains one compound.  d box q contains two compounds and box r contains a mixture.      6 the number of particles in atoms w, x, y and z are shown.     protons electrons neutrons  w 6 6 6  x 6 6 7  y 7 7 7  z 7 7 8    which statement is correct?  a w and x are isotopes of carbon.  b x and y are isotopes of nitrogen.  c x has a mass number of 12.  d z has an atomic number of 8.      7 which row describes the type of bonding present in substances 1 and 2?     substance 1 substance 2  a methane has ionic bonding graphite has covalent bonding  b graphite has ionic bonding potassium chloride has covalent bonding  c potassium chloride has ionic bonding methane has covalent bonding  d potassium chloride has ionic bonding graphite has ionic bonding     ",
            "4": "4  \u00a9 ucles 2017 0620/11/o/n/17  8 substances with giant covalent structures can be used as lubricants and as cutting tools for hard  materials.    the diagram shows how the atoms are arranged in two giant covalent substances, x and y.    x y key strong covalentbond weak attraction     which statement is correct?  a only x is used as a cutting tool and only y is used as a lubricant.  b only x is used as a lubricant and only y is used as a cutting tool.  c x and y are both used as cutting tools.  d x and y are both used as lubricants.     9 the equation shows the thermal decomposition of magnesium carbonate ( m r = 84).    mgco 3  \u2192  mgo  +  co 2    which mass of magnesium oxide is formed when 21.0  g of magnesium carbonate are completely  decomposed?  a 1.9  g b 4.0  g c 10.0  g d 40.0  g    ",
            "5": "5  \u00a9 ucles 2017 0620/11/o/n/17 [turn over  10 electricity is passed through concentrated aqueous sodium chloride. inert electrodes are used.    +\u2013 concentrated aqueous sodiumchloride     what is formed at the negative electrode?  a chlorine  b hydrogen  c oxygen  d sodium     11 two chemical processes are described.    \u25cf during the combustion of gasoline, energy is ..1.. .  \u25cf during the electrolysis of sulfuric acid, energy is ..2.. .    which words complete gaps 1 and 2?     1 2  a given out given out  b given out taken in  c taken in given out  d taken in taken in     ",
            "6": "6  \u00a9 ucles 2017 0620/11/o/n/17  12 when dilute sulfuric acid reacts with aqueous sodium hydroxide, the temperature of the solution  increases.    which words describe this reaction?  a endothermic and neutralisation  b endothermic and redox  c exothermic and neutralisation  d exothermic and redox    13 the mass of a beaker and its contents is plotted against time.    which graph represents what happens when sodium carbonate reacts with an excess of dilute hydrochloric acid in an open beaker?    mass  time a mass  time b mass  time c mass  time d 00000000       14 when blue copper( ii) sulfate is heated, a white solid and water are formed.    the white solid turns blue and gives out heat when water is added to it.    which terms describe the blue copper( ii) sulfate and the reactions?     the blue  copper( ii) sulfate is reactions  a a mixture can be reversed  b a mixture cannot be reversed  c hydrated can be reversed  d hydrated cannot be reversed      15 which changes increase the rate of reaction between calcium carbonate and dilute  hydrochloric acid?    1 increasing the concentration of the acid  2 increasing the temperature  3 increasing the size of the pieces of calcium carbonate    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only ",
            "7": "7  \u00a9 ucles 2017 0620/11/o/n/17 [turn over  16 the equations for two reactions p and q are given.    p 2nano 2  +  o 2  \u2192  2nano 3  q 2hgo  \u2192  2hg  +  o 2    in which of these reactions does oxidation of the underlined substance occur?     p q  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a      17 what is not a typical characteristic of acids?  a they react with alkalis producing water.  b they react with all metals producing hydrogen.  c they react with carbonates producing carbon dioxide.  d they turn blue litmus paper red.     18 magnesium, phosphorus and chlorine are elements in the same period of the periodic table.    which row describes the type of oxid e formed by each of these elements?     magnesium phosphorus chlorine  a acidic acidic basic  b acidic basic basic  c basic acidic acidic  d basic basic acidic     19 zinc sulfate is made by reacting an excess of zinc oxide with dilute sulfuric acid.    the excess zinc oxide is then removed from the solution.    which process is used to obtain solid zinc sulfate from the solution?  a crystallisation  b dissolving  c filtration  d fractional distillation     ",
            "8": "8  \u00a9 ucles 2017 0620/11/o/n/17  20 what is used to test for chlorine?  a a glowing splint  b damp litmus paper  c limewater  d potassium manganate( vii) solution      21 which statements about the trends across a period of the periodic table are correct?    1 aluminium is more metallic than sodium.  2 beryllium is more metallic than carbon. 3 boron is more metallic than lithium.  4 magnesium is more metallic than silicon.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4    22 astatine is an element in group vii of the periodic table.    astatine is ..1.. reactive than iodine.    the melting point of astatine is ..2.. than the melting point of iodine.    astatine is ..3.. in colour than bromine.    which words complete gaps 1, 2 and 3?     1 2 3  a less higher darker  b less lower lighter  c more higher darker  d more lower lighter      23 which row describes the properties of a typical transition element?     melting point forms coloured  compounds can act as  a catalyst  a high no no  b high yes yes  c low no yes  d low yes no     ",
            "9": "9  \u00a9 ucles 2017 0620/11/o/n/17 [turn over  24 why is argon gas used to fill electric lamps?  a it conducts electricity.  b it glows when heated.  c it is less dense than air.  d it is not reactive.      25 what is a property of all metals?  a conduct electricity  b hard  c low melting points  d react with water      26 which material is not involved in the large-scale extraction of iron from iron ore?  a bauxite  b calcium carbonate (limestone)  c carbon (coke)  d hematite     ",
            "10": "10  \u00a9 ucles 2017 0620/11/o/n/17  27 some reactions of three metals are listed in the table.    metal metal reacts with dilute  hydrochloric acid metal oxide is  reduced by carbon  p yes no  q no yes  r yes yes    what is the order of reactivity of the metals?     most  reactive  least  reactive  a p r q  b q p r  c r p q  d r q p      28 which uses of the metals shown are both correct?     aluminium stainless steel  a aircraft bodies cutlery  b car bodies aircraft bodies  c chemical plant food containers  d food containers car bodies      29 the flow chart shows stages in the treatment of river water to produce drinking water.    drinking waterstage ystage xsettling tankriver water    what occurs at stages x and y?     x y  a distillation chlorination  b distillation filtration  c filtration chlorination  d filtration distillation     ",
            "11": "11  \u00a9 ucles 2017 0620/11/o/n/17 [turn over  30 which gas is over 30% of air?  a argon  b carbon dioxide  c nitrogen  d oxygen      31 iron is a metal that rusts in the presence of oxygen and water.    mild steel is used for ..1.. and is prevented from rusting by ..2.. .    stainless steel does not rust. it is produced by ..3.. iron with another metal.    which words complete gaps 1, 2 and 3?     1 2 3  a car bodies greasing covering  b car bodies painting mixing  c cutlery greasing covering  d cutlery painting mixing      32 a mixture produces a gas both when it reacts with an acid and when it reacts with an alkali.    which ions are present in the mixture?  a ammonium ions and carbonate ions  b ammonium ions and oxide ions  c hydrogen ions and carbonate ions  d hydrogen ions and oxide ions    33 some marble chips (calcium carbonate) are heated strongly and substances x and y are formed.    substance x is a white solid that reacts with water, giving out heat. substance y is a colourless  gas.    what are substances x and y?     x y  a calcium chloride oxygen  b calcium hydroxide carbon dioxide  c calcium oxide carbon dioxide  d calcium sulfate oxygen   ",
            "12": "12  \u00a9 ucles 2017 0620/11/o/n/17  34 the structures of some organic molecules are shown.    c c ch3h h3ch cch3 hhh c ch3 hcch3 hhh c h hcch3 hc h3h c h h2 13 4     which structures represent an alkane with four carbon atoms?  a 1 only b 2 and 3 c 2 and 4 d 3 and 4      35 some of the fractions obtained from the fractional  distillation of petroleum are used as fuels for  vehicles.    which two fractions are used as fuels for vehicles?  a bitumen fraction and gasoline fraction  b bitumen fraction and naphtha fraction  c gasoline fraction and kerosene fraction  d kerosene fraction and lubricating fraction    36 burning fossil fuels releases heat energy.    which substance is not a fossil fuel?  a coal  b hydrogen  c natural gas  d petroleum     37 x, y and z are three hydrocarbons.    x ch 2=ch 2 y ch 3\u2013ch=ch 2 z ch 3\u2013ch 2\u2013ch=ch 2    what do compounds x, y and z have in common?    1 they are all alkenes.  2 they are all part of the same homologous series. 3 they all have the same boiling point.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "13": "13  \u00a9 ucles 2017 0620/11/o/n/17 [turn over  38 the table shows bonds that are present and bonds that are not present in compound x.    bond   c\u2013c \u0016  c=c \u001a  c\u2013h \u0016  c\u2013o \u0016  c=o \u0016  o\u2013h \u0016    what type of compound is x?  a a carboxylic acid  b an alcohol  c an alkane  d an alkene     39 the diagram shows a reaction sequence.    butane ethene ethanolcarbon dioxide and waterxyz     which row names the processes x, y and z?     x y z  a cracking fermentation respiration  b cracking hydration combustion  c distillation fermentation respiration  d distillation hydration combustion     ",
            "14": "14  \u00a9 ucles 2017 0620/11/o/n/17  40 molecules of a substance react together as shown.    hhhh cc hhhh cc hh c hh c hh c hh c hh c hh c hhhh cc + +      which type of reaction has taken place?  a cracking  b oxidation  c polymerisation  d reduction    ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/11/o/n/17  blank page",
            "16": "16  \u00a9 ucles 2017 0620/11/o/n/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w17_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 15 printed pages and 1 blank page.  ib17 11_0620_12/3rp  \u00a9 ucles 2017 [turn over     *1011389924 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice (core)  october/november 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/12/o/n/17  1 the melting points and boiling points of four elements are shown.    element melting  point  / \u00b0c boiling  point  / \u00b0c  w \u20137 60  x \u2013101 \u201334  y 114 184  z 39 688    in which elements do the particles vibrate about fixed positions at 0  \u00b0c?  a w and x b w and z c x and y d y and z     2 the apparatus used to separate a mixture is shown.    mixture funnel filter paper     what is the mixture?  a aqueous calcium chloride and aqueous calcium nitrate  b calcium carbonate and aqueous calcium chloride  c ethanol and water  d sand and calcium carbonate     3 during an experiment a measurement is recorded in cm 3.    which apparatus is used?  a balance  b measuring cylinder  c stopclock  d thermometer     ",
            "3": "3  \u00a9 ucles 2017 0620/12/o/n/17 [turn over  4 substance q boils at 445  \u00b0c and is a yellow solid at room temperature.    which temperature could be the melting point of pure q?  a \u20139  \u00b0c  b 72  \u00b0c to 78  \u00b0c  c 116  \u00b0c  d 116  \u00b0c to 126  \u00b0c     5 which diagram shows a mixture of an element and a compound?    a b c d     6 which pair of atoms contains the same number of neutrons?  a  co59 27  and ni5928  b cu6429 and cu6529  c cu6429 and zn6530  d cu6529 and zn6530      7 in which row do the properties described match the type of bonding?     melting point electrical conductivity  when liquid type of bonding  a high  does not conduct  ionic  b low conducts covalent  c low conducts ionic  d low does not conduct covalent    ",
            "4": "4  \u00a9 ucles 2017 0620/12/o/n/17  8 which statement explains why graphite is used a lubricant?  a all bonds between the atoms are weak.  b it conducts electricity.  c it has a low melting point.  d layers in the structure can slide over each other.      9 what is the relative formula mass of magnesium nitrate, mg(no 3)2?  a 74 b 86 c 134 d 148     10 the diagram shows the electrolysis of two solutions using inert electrodes.    dilute sulfuric acidconcentrated aqueoussodium chloridepq rs +\u2013 +\u2013     which substance is made at each electrode?     p q r s  a hydrogen oxygen chlorine sodium  b hydrogen oxygen sodium chlorine  c oxygen hydrogen chlorine hydrogen  d oxygen hydrogen hydrogen chlorine     ",
            "5": "5  \u00a9 ucles 2017 0620/12/o/n/17 [turn over  11 two chemical processes are described.    \u25cf during the combustion of ethanol, energy is ..1.. .  \u25cf during the electrolysis of aqueous sodium chloride, energy is ..2.. .    which words complete gaps 1 and 2?     1 2  a given out given out  b given out taken in  c taken in given out  d taken in taken in      12 water is added to anhydrous copper( ii) sulfate in a test-tube.    the mixture becomes hot.    which type of reaction and energy level diagram apply to this reaction?     type of reaction energy level diagram  a endothermic energyreactants products   b endothermic energy reactantsproducts   c exothermic energyreactants products   d exothermic energy reactantsproducts      ",
            "6": "6  \u00a9 ucles 2017 0620/12/o/n/17  13 the mass of a beaker and its contents is plotted against time.    which graph represents what happens when sodium carbonate reacts with an excess of dilute hydrochloric acid in an open beaker?    mass  time a mass  time b mass  time c mass  time d 00000000       14 when blue copper( ii) sulfate is heated, a white solid and water are formed.    the white solid turns blue and gives out heat when water is added to it.    which terms describe the blue copper( ii) sulfate and the reactions?     the blue  copper( ii) sulfate is reactions  a a mixture can be reversed  b a mixture cannot be reversed  c hydrated can be reversed  d hydrated cannot be reversed     ",
            "7": "7  \u00a9 ucles 2017 0620/12/o/n/17 [turn over  15 an experiment was carried out to find the rate of reaction when 1  g of solid x reacts with 100  cm3  of solution y.    solution y solid xgas syringe     the experiment took place too quickly for measurements to be made.    which change could be made to slow down the reaction?  a add a catalyst  b decrease the concentration of solution y  c decrease the particle size of solid x  d increase the temperature    16 the equations for two reactions p and q are given.    p 2nano 2  +  o 2  \u2192  2nano 3  q 2hgo  \u2192  2hg  +  o 2    in which of these reactions does oxidation of the underlined substance occur?     p q  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a      17 what is not a typical characteristic of acids?  a they react with alkalis producing water.  b they react with all metals producing hydrogen.  c they react with carbonates producing carbon dioxide.  d they turn blue litmus paper red.    ",
            "8": "8  \u00a9 ucles 2017 0620/12/o/n/17  18 elements q and r both burn in air.    the oxides formed both dissolve in water.    the solution of the oxide formed from element q turns universal indicator red.    the solution of the oxide formed from element r turns universal indicator blue.    what are q and r?     q r  a carbon sulfur  b sodium magnesium  c sodium sulfur  d sulfur sodium      19 copper( ii) sulfate can be prepared by adding excess copper( ii) carbonate to sulfuric acid.    why is an excess  of copper( ii) carbonate added?  a to ensure all the copper( ii) carbonate has reacted  b to ensure all the sulfuric acid has reacted  c to increase the rate of reaction  d to increase the yield of copper( ii) sulfate     20 compound p reacts with hydrochloric acid to produce a gas that turns limewater milky.    what is p?  a sodium carbonate  b sodium chloride  c sodium hydroxide  d sodium sulfate     21 which statement about nitrogen and phosphorus is not correct?  a both are in the same group of the periodic table.  b both are in the same period of the periodic table.  c both are non-metals.  d both have the same number of electrons in their outer shell.    ",
            "9": "9  \u00a9 ucles 2017 0620/12/o/n/17 [turn over  22 sodium and rubidium are elements in group i of the periodic table.    which statement is correct?  a sodium atoms have more electrons than rubidium atoms.  b sodium has a lower density than rubidium.  c sodium has a lower melting point than rubidium.  d sodium is more reactive than rubidium.    23 which properties do the elements chromium, iron and vanadium have in common?    1 they all conduct electricity.  2 they, or their compounds, can act as catalysts. 3 they all form coloured compounds.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      24 why is argon gas used to fill electric lamps?  a it conducts electricity.  b it glows when heated.  c it is less dense than air.  d it is not reactive.      25 what is a property of all metals?  a conduct electricity  b hard  c low melting points  d react with water      26 which process is used to extract iron from hematite in the blast furnace?  a electrolysis  b reduction with carbon monoxide  c reduction with lime  d thermal decomposition     ",
            "10": "10  \u00a9 ucles 2017 0620/12/o/n/17  27 some reactions of three metals are listed in the table.    metal metal reacts with dilute  hydrochloric acid metal oxide is  reduced by carbon  p yes yes  q yes no  r no yes    what is the order of reactivity of the metals?     most  reactive  least  reactive  a p q r  b p r q  c q p r  d r p q      28 which uses of the metals shown are both correct?     aluminium copper  a aircraft bodies electrical wiring  b car bodies aircraft bodies  c chemical plant cooking utensils  d food containers chemical plant      29 the flow chart shows stages in the treatment of river water to produce drinking water.    drinking waterstage ystage xsettling tankriver water    what occurs at stages x and y?     x y  a distillation chlorination  b distillation filtration  c filtration chlorination  d filtration distillation     ",
            "11": "11  \u00a9 ucles 2017 0620/12/o/n/17 [turn over  30 which element in group vi is a component of air?  a argon  b nitrogen  c oxygen  d sulfur      31 iron is a metal that rusts in the presence of oxygen and water.    mild steel is used for ..1.. and is prevented from rusting by ..2.. .    stainless steel does not rust. it is produced by ..3.. iron with another metal.    which words complete gaps 1, 2 and 3?     1 2 3  a car bodies greasing covering  b car bodies painting mixing  c cutlery greasing covering  d cutlery painting mixing      32 a chemical reaction is carried out on substance x.    a gas is produced that turns red litmus paper blue.    what is this reaction?  a the reaction of an acid with a metal carbonate  b the reaction of an acid with an ammonium salt  c the reaction of an alkali with a metal carbonate  d the reaction of an alkali with an ammonium salt    ",
            "12": "12  \u00a9 ucles 2017 0620/12/o/n/17  33 some marble chips (calcium carbonate) are heated strongly and substances x and y are formed.    substance x is a white solid that reacts with water, giving out heat. substance y is a colourless gas.    what are substances x and y?     x y  a calcium chloride oxygen  b calcium hydroxide carbon dioxide  c calcium oxide carbon dioxide  d calcium sulfate oxygen      34 the structures of four organic compounds are shown.    hc hh c hhhhs hh c c h hc hh c hht hc hh c hhv hc ch c chu h h h hh     which compounds are unsaturated?  a s only b t and u c u only d v only      35 which statement is not correct?  a petroleum is a mixture of hydrocarbons.  b the main constituent of natural gas is ethane.  c the naphtha fraction of petroleum is used for making chemicals.  d when natural gas burns in air, carbon dioxide and water are formed.      36 which equation represents the complete combustion of butane, c 4h10?  a 2c 4h10  +  5o 2  \u2192  8c  +  10h 2o  b 2c 4h10  +  9o 2  \u2192  8co  +  10h 2o  c 2c 4h10  +  13o 2  \u2192  8co 2  +  10h 2o  d c 4h10  +  4o 2  \u2192  4co 2  +  5h 2     ",
            "13": "13  \u00a9 ucles 2017 0620/12/o/n/17 [turn over  37 x, y and z are three hydrocarbons.    x ch 2=ch 2 y ch 3\u2013ch=ch 2 z ch 3\u2013ch 2\u2013ch=ch 2    what do compounds x, y and z have in common?    1 they are all alkenes.  2 they are all part of the same homologous series. 3 they all have the same boiling point.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    38 the table shows bonds that are present and bonds that are not present in compound x.    bond   c\u2013c \u0016  c=c \u001a  c\u2013h \u0016  c\u2013o \u0016  c=o \u0016  o\u2013h \u0016    what type of compound is x?  a a carboxylic acid  b an alcohol  c an alkane  d an alkene     39 the diagram shows a reaction sequence.    butane ethene ethanolcarbon dioxide and waterxyz     which row names the processes x, y and z?     x y z  a cracking fermentation respiration  b cracking hydration combustion  c distillation fermentation respiration  d distillation hydration combustion   ",
            "14": "14  \u00a9 ucles 2017 0620/12/o/n/17  40 molecules of a substance react together as shown.    hhhh cc hhhh cc hh c hh c hh c hh c hh c hh c hhhh cc + +      which type of reaction has taken place?  a cracking  b oxidation  c polymerisation  d reduction    ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/12/o/n/17  blank page",
            "16": "16  \u00a9 ucles 2017 0620/12/o/n/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w17_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 16 printed pages.  ib17 11_0620_13/4rp  \u00a9 ucles 2017 [turn over     *5136071969 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice (core)  october/november 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/13/o/n/17  1 which statement about liquids and gases is correct?  a 1 cm3 of gas contains more particles than 1  cm3 of liquid.  b a given mass of liquid has a fixed volume at room temperature.  c particles in a liquid can easily be forced closer together.  d particles in a liquid have fixed positions.      2 which method is used to obtain copper( ii) sulfate crystals from an aqueous solution of  copper( ii) sulfate?  a chromatography  b condensation  c evaporation  d filtration      3 25  cm3 of an alkali are added to 20  cm3 of an acid. the temperature change is measured.    which apparatus is not needed in the experiment?  a 25  cm3 measuring cylinder  b 100  cm3 beaker  c balance  d thermometer      4 a sample of liquid x turns blue cobalt( ii) chloride paper pink. the sample boils at 102  \u00b0c.    which statements are correct?    1 x contains water.  2 x is impure water.  3 x freezes above 0  \u00b0c.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "3": "3  \u00a9 ucles 2017 0620/13/o/n/17 [turn over  5 substance y is added to an excess of hot water.    a blue solution forms and a brown solid remains.    the brown solid is filtered off and dried.    the brown solid conducts electricity.    what is y?  a a compound which contains a metal  b a mixture which contains a metal  c a pure substance which is a metal  d a pure substance which is a non-metal     6 which row gives the number of protons, electrons and neutrons found in an atom of zinc?     protons electrons neutrons  a 30 30 35  b 30 35 35  c 35 30 30  d 35 35 30    7 four statements about atoms and ions are shown.    1 f \u2013 has more electrons than na+.  2 mg2+ has the same number of electrons as na+.  3 na+ has more electrons than li+.  4 an atom of p has more outer shell electrons than an atom of n.    which statements are correct?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     ",
            "4": "4  \u00a9 ucles 2017 0620/13/o/n/17  8 the diagrams, x, y and z, show part of a polymer and two giant covalent structures.    y xz     which of x, y or z could be used as a cutting tool and which of x, y or z could be used to reduce  friction?     cutting tool reduce friction a x y  b y z  c z x  d z y     9 a compound with the formula xo 2 has a relative formula mass of 64.    what is x?  a cadmium  b copper  c gadolinium  d sulfur     ",
            "5": "5  \u00a9 ucles 2017 0620/13/o/n/17 [turn over  10 the electrolysis of concentrated hydrochloric  acid using platinum electrodes is shown.    concentrated hydrochloric acid+\u2013     what is observed at each electrode at the start of the electrolysis?     positive electrode negative electrode a colourless gas colourless gas  b colourless gas green gas  c green gas colourless gas  d green gas green gas     11 two chemical processes are described.    \u25cf during the combustion of kerosene, energy is ..1.. .  \u25cf during the electrolysis of hydrochloric acid, energy is ..2.. .    which words complete gaps 1 and 2?     1 2  a given out given out  b given out taken in  c taken in given out  d taken in taken in      12 which reaction is endothermic?  a neutralisation of an acid by an alkali  b reaction of hydrogen with oxygen  c reaction of sodium with water  d thermal decomposition of limestone    ",
            "6": "6  \u00a9 ucles 2017 0620/13/o/n/17  13 the mass of a beaker and its contents is plotted against time.    which graph represents what happens when sodium carbonate reacts with an excess of dilute hydrochloric acid in an open beaker?    mass  time a mass  time b mass  time c mass  time d 00000000       14 when blue copper( ii) sulfate is heated, a white solid and water are formed.    the white solid turns blue and gives out heat when water is added to it.    which terms describe the blue copper( ii) sulfate and the reactions?     the blue  copper( ii) sulfate is reactions  a a mixture can be reversed  b a mixture cannot be reversed  c hydrated can be reversed  d hydrated cannot be reversed     ",
            "7": "7  \u00a9 ucles 2017 0620/13/o/n/17 [turn over  15 the equation for the reaction between magnesium and hydrochloric acid is shown.    mg  +  2hc l  \u2192  mgc l 2  +  h 2    the rate of this reaction is studied using the apparatus shown.    hydrochloric acid magnesium ribbongas syringe     which change increases the rate of reaction?  a lowering the temperature of the acid  b using a larger volume of the same hydrochloric acid  c using less concentrated hydrochloric acid  d using the same mass of magnesium powder    16 the equations for two reactions p and q are given.    p 2nano 2  +  o 2  \u2192  2nano 3  q 2hgo  \u2192  2hg  +  o 2    in which of these reactions does oxidation of the underlined substance occur?     p q  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a      17 what is not a typical characteristic of acids?  a they react with alkalis producing water.  b they react with all metals producing hydrogen.  c they react with carbonates producing carbon dioxide.  d they turn blue litmus paper red.    ",
            "8": "8  \u00a9 ucles 2017 0620/13/o/n/17  18 which oxide produces a solution with a ph between ph  1 and ph  7 when reacted with water?  a calcium oxide  b carbon dioxide  c potassium oxide  d sodium oxide      19 three solids, p, q and r, all react with dilute sulfuric acid to produce zinc sulfate.    p and r produce gases during the reaction.    the gas produced when p reacts will not burn. the gas produced when r reacts will burn.    what are p, q and r?     p q r  a zinc zinc hydroxide zinc carbonate  b zinc carbonate zinc zinc oxide  c zinc carbonate zinc hydroxide zinc  d zinc oxide zinc carbonate zinc      20 which ion forms a green precipitate with aqueous sodium hydroxide that dissolves in an excess  of aqueous sodium hydroxide?  a ca2+ b cr3+ c cu2+ d fe2+    21 a period of the periodic table is shown.    group i ii iii iv v vi vii viii  element r s t v w x y z    the letters are not their chemical symbols.    which statement is correct?  a element r does not conduct electricity.  b elements r and y react together to form an ionic compound.  c element z exists as a diatomic molecule.  d element z reacts with element t.    ",
            "9": "9  \u00a9 ucles 2017 0620/13/o/n/17 [turn over  22 some properties of element x are shown.    melting point   in  \u00b0c 98  boiling point   in  \u00b0c 883  reaction with cold water gives off h 2 gas  reaction when heated with oxygen burns to give a white solid    in which part of the periodic table is x found?  a group i  b group vii  c group viii  d transition elements    23 the table gives some properties of an element.    melting point in \u00b0c 3422  appearance of the element grey  appearance of the chloride of the element dark blue  density in g  / cm3 19.2  electrical conductivity when solid good    which other property would you expect this element to have?  a acts as a catalyst  b brittle  c forms an acidic oxide  d highly reactive with water      24 why is argon gas used to fill electric lamps?  a it conducts electricity.  b it glows when heated.  c it is less dense than air.  d it is not reactive.     ",
            "10": "10  \u00a9 ucles 2017 0620/13/o/n/17  25 what is a property of all metals?  a conduct electricity  b hard  c low melting points  d react with water      26 what is the reducing agent in the large-scale extraction of iron from iron ore?  a air  b carbon monoxide  c hematite  d limestone      27 some reactions of three metals are listed in the table.    metal metal reacts with dilute  hydrochloric acid metal oxide is reduced  by carbon  p yes no  q yes yes  r no yes    what is the order of reactivity of the metals?     most  reactive  least  reactive  a p q r  b p r q  c q p r  d r p q      28 which uses of the metals shown are both correct?     aluminium stainless steel  a aircraft bodies car bodies  b car bodies aircraft bodies  c chemical plant food containers  d food containers cutlery     ",
            "11": "11  \u00a9 ucles 2017 0620/13/o/n/17 [turn over  29 the flow chart shows stages in the treatment of river water to produce drinking water.    drinking waterstage ystage xsettling tankriver water    what occurs at stages x and y?     x y  a distillation chlorination  b distillation filtration  c filtration chlorination  d filtration distillation     30 what is produced by the incomplete combustion of methane?  a carbon monoxide  b hydrogen  c lead compounds  d sulfur dioxide     31 iron is a metal that rusts in the presence of oxygen and water.    mild steel is used for ..1.. and is prevented from rusting by ..2.. .    stainless steel does not rust. it is produced by ..3.. iron with another metal.    which words complete gaps 1, 2 and 3?     1 2 3  a car bodies greasing covering  b car bodies painting mixing  c cutlery greasing covering  d cutlery painting mixing     ",
            "12": "12  \u00a9 ucles 2017 0620/13/o/n/17  32 compound q is heated with aqueous sodium hydroxide.    damp red litmus paper q and aqueoussodium hydroxide heat    the damp red litmus paper turns blue.    what is q?  a ammonium chloride  b copper( ii) chloride  c iron( iii) chloride  d sodium chloride     33 some marble chips (calcium carbonate) are heated strongly and substances x and y are formed.    substance x is a white solid that reacts with water, giving out heat. substance y is a colourless  gas.    what are substances x and y?     x y  a calcium chloride oxygen  b calcium hydroxide carbon dioxide  c calcium oxide carbon dioxide  d calcium sulfate oxygen     ",
            "13": "13  \u00a9 ucles 2017 0620/13/o/n/17 [turn over  34 the structure of compound r is shown.    co h h ch hhh chh     what is r?  a propane  b propanoic acid  c propanol  d propene    35 fuel oil and naphtha are two fractions obtained from petroleum.    what are the major uses of these fractions?     fuel oil naphtha  a jet fuel making chemicals  b jet fuel making roads  c ship fuel making chemicals  d ship fuel making roads     36 what are the products of the complete combustion of ethanol?  a co  +  h 2  b co  +  h 2o  c co 2  +  h 2  d co 2  +  h 2o     37 x, y and z are three hydrocarbons.    x ch 2=ch 2 y ch 3\u2013ch=ch 2 z ch 3\u2013ch 2\u2013ch=ch 2    what do compounds x, y and z have in common?    1 they are all alkenes.  2 they are all part of the same homologous series. 3 they all have the same boiling point.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only   ",
            "14": "14  \u00a9 ucles 2017 0620/13/o/n/17  38 the table shows bonds that are present and bonds that are not present in compound x.    bond   c\u2013c \u0016  c=c \u001a  c\u2013h \u0016  c\u2013o \u0016  c=o \u0016  o\u2013h \u0016    what type of compound is x?  a a carboxylic acid  b an alcohol  c an alkane  d an alkene     39 the diagram shows a reaction sequence.    butane ethene ethanolcarbon dioxide and waterxyz     which row names the processes x, y and z?     x y z  a cracking fermentation respiration  b cracking hydration combustion  c distillation fermentation respiration  d distillation hydration combustion     ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/13/o/n/17  40 molecules of a substance react together as shown.    hhhh cc hhhh cc hh c hh c hh c hh c hh c hh c hhhh cc + +      which type of reaction has taken place?  a cracking  b oxidation  c polymerisation  d reduction    ",
            "16": "16  \u00a9 ucles 2017 0620/13/o/n/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w17_qp_21.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib17 11_0620_21/3rp  \u00a9 ucles 2017 [turn over     *1790619835 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/21     paper 2 multiple choice (extended)  october/november 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2017 0620/21/o/n/17  1 which process causes the greatest increase in the distance between particles?  a condensation  b freezing  c melting  d sublimation      2 a student put 25.0  cm3 of dilute hydrochloric acid into a conical flask.    the student added 2.5  g of solid sodium carbonate and measured the change in temperature of  the mixture.    which apparatus does the student need to use to obtain the most accurate results?  a balance, measuring cylinder, thermometer  b balance, pipette, stopwatch  c balance, pipette, thermometer  d burette, pipette, thermometer      3 the results obtained from a chromatogram are shown.     distance travelled  / cm  solvent 5.0  substance x 3.0  substance y 2.5    which row gives the rf values of substance x and substance y?     rf (x) rf (y)  a 0.5 0.6  b 0.6 0.5  c 1.6 2.0  d 2.0 1.6     ",
            "3": "3  \u00a9 ucles 2017 0620/21/o/n/17 [turn over  4 two statements about silicon( iv) oxide are given.    1 it is a hard substance.  2 it has a macromolecular structure with strong covalent bonds.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statem ent 2 does not explain statement 1.  c statement 1 is correct but statement 2 is not correct.  d statement 2 is correct but statement 1 is not correct.    5 which statement explains why isotopes of the same element have the same chemical properties?  a they have a different number of neutrons in the nucleus.  b they have the same number of neutrons in the nucleus.  c they have the same number of outer shell electrons.  d they have the same number of protons as neutrons.     6 which dot-and-cross diagram shows the outer shell electron arrangement in a molecule of  nitrogen?    na n nb n nc n nd n      7 the equation for the reaction between barium chloride solution and dilute sulfuric acid is shown.    bac l  2  +  h 2so 4  \u2192  baso 4  +  2hc l    which row shows the state symbols for this equation?     bac l 2 h2so 4 baso 4 2hc l  a (aq) (aq) (s) (aq)  b (aq) (l) (s) (aq)  c (l) (aq) (s) (l)  d (aq) (l) (aq) (l)     ",
            "4": "4  \u00a9 ucles 2017 0620/21/o/n/17  8 a compound is analysed and found to contain 85.7% carbon and 14.3% hydrogen.    what is its empirical formula?  a ch b ch 2 c c 2h4 d c 6h     9 which statements about the electrolysis of concentrated copper( ii) chloride are correct?    1 electrons are transferred from the cathode to the copper( ii) ions.  2 electrons move round the external circuit from the cathode to the anode.  3 chloride ions are attracted to the anode. 4 hydroxide ions transfer electrons to the cathode.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    10 which metal combination produces the highest voltage reading in the cells shown?    va fe cuvb zn cu vc cu cuvd mg cu      ",
            "5": "5  \u00a9 ucles 2017 0620/21/o/n/17 [turn over  11 the compound hydrazine is used as a rocket fuel. it has the structural formula shown.    nh hh hn     one of the reactions of hydrazine is shown. this reaction is exothermic.    n2h4  \u2192  n2  +  2h 2    the bond energies are shown in the table.     bond energy  in kj  / mol  h\u2013h +436  n\u2013h +390  n\u2013n +160  n\u2261n +945    what is the energy change for this reaction?  a \u2013339  kj / mol b \u201397  kj / mol c +97  kj / mol d +339  kj / mol      12 which statement describes an exothermic reaction?  a the energy absorbed for bond breaking is greater than the energy released by bond  formation.  b the energy absorbed for bond breaking is less than the energy released by bond formation.  c the energy released by bond breaking is greater than the energy absorbed for bond  formation.  d the energy released by bond breaking is less than the energy absorbed for bond formation.    13 the mass of a beaker and its contents is plotted against time.    which graph represents what happens when sodium carbonate reacts with an excess of dilute  hydrochloric acid in an open beaker?    mass  time a mass  time b mass  time c mass  time d 00000000    ",
            "6": "6  \u00a9 ucles 2017 0620/21/o/n/17  14 copper( ii) oxide reacts with hydrogen.    cuo  +  h 2  \u2192  cu  +  h 2o    which row is correct?     oxidising agent reducing agent  a h2 cuo  b cuo h 2  c h2o cu  d cu h 2o      15 ethanoic acid reacts slowly with calcium carbonate.    which statements explain why an increase in temperature increases the rate of the reaction?    1 the activation energy of the reaction is decreased.  2 there is an increase in collision rate.  3 the particles have more energy.  4 there will be fewer successful collisions.    a 1 and 2 b 1 and 3 c 2 and 3 d 2 and 4      16 methane reacts with steam to produce hydrogen and carbon monoxide.    the equation for the reaction is shown.    ch 4(g)  +  h 2o(g)    3h 2(g)  +  co(g)    the reaction is reversible. the forward reaction is endothermic.    which changes in temperature and pressure increase the equilibrium yield of carbon monoxide?     temperature pressure  a decrease decrease  b decrease increase  c increase decrease  d increase increase     ",
            "7": "7  \u00a9 ucles 2017 0620/21/o/n/17 [turn over  17 some properties of four oxides are listed.    oxide 1 reacts with both acids and alkalis to form salts.    oxide 2 reacts with acids to form sa lts but does not react with alkalis.    oxide 3 reacts with alkalis to form salts but does not react with acids.    oxide 4 does not react with acids or alkalis.    which row describes the oxides?     oxide 1 oxide 2 oxide 3 oxide 4  a amphoteric acidic basic neutral  b amphoteric basic acidic neutral  c neutral acidic basic amphoteric  d neutral basic acidic amphoteric     18 what is not a typical characteristic of acids?  a they react with alkalis producing water.  b they react with all metals producing hydrogen.  c they react with carbonates producing carbon dioxide.  d they turn blue litmus paper red.     19 zinc sulfate is made by reacting an excess of zinc oxide with dilute sulfuric acid.    the excess zinc oxide is then removed from the solution.    which process is used to obtain solid zinc sulfate from the solution?  a crystallisation  b dissolving  c filtration  d fractional distillation     20 what is used to test for chlorine?  a a glowing splint  b damp litmus paper  c limewater  d potassium manganate( vii) solution     ",
            "8": "8  \u00a9 ucles 2017 0620/21/o/n/17  21 which statements about the trends across a period of the periodic table are correct?    1 aluminium is more metallic than sodium.  2 beryllium is more metallic than carbon.  3 boron is more metallic than lithium.  4 magnesium is more metallic than silicon.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     22 astatine is an element in group vii of the periodic table.    astatine is ..1.. reactive than iodine.    the melting point of astatine is ..2.. than the melting point of iodine.    astatine is ..3.. in colour than bromine.    which words complete gaps 1, 2 and 3?     1 2 3  a less higher darker  b less lower lighter  c more higher darker  d more lower lighter     23 which row describes the properties of a typical transition element?     melting point forms coloured  compounds can act as  a catalyst  a high no no  b high yes yes  c low no yes  d low yes no      24 why is argon gas used to fill electric lamps?  a it conducts electricity.  b it glows when heated.  c it is less dense than air.  d it is not reactive.    ",
            "9": "9  \u00a9 ucles 2017 0620/21/o/n/17 [turn over  25 what is a property of all metals?  a conduct electricity  b hard  c low melting points  d react with water      26 aluminium is extracted by the electrolysis of aluminium oxide.    which statement is not correct?  a aluminium ions are oxidised at the cathode.  b carbon dioxide is made at the anode.  c cryolite is added to lower the melting point of the aluminium oxide.  d the electrodes are made from graphite.    27 which row describes how the metals are used?     mixed with zinc  to form brass used to  galvanise iron  a aluminium tin  b aluminium zinc  c copper tin  d copper zinc     ",
            "10": "10  \u00a9 ucles 2017 0620/21/o/n/17  28 information about the nitrates and carbonates of two metals, q and r, is shown.     appearance solubility in water effect of heat  nitrate of q   white solid   soluble   colourless gas evolved which  relights a glowing splint  carbonate of q white solid soluble no reaction  nitrate of r white solid soluble brown gas evolved  carbonate of r   white solid   insoluble   colourless gas evolved which  turns limewater milky    which statement is correct?  a q is calcium and r is magnesium.  b q is magnesium and r is sodium.  c q is potassium and r is copper.  d q is sodium and r is calcium.     29 the flow chart shows stages in the treatment of river water to produce drinking water.    drinking waterstage ystage xsettling tankriver water    what occurs at stages x and y?     x y  a distillation chlorination  b distillation filtration  c filtration chlorination  d filtration distillation     ",
            "11": "11  \u00a9 ucles 2017 0620/21/o/n/17 [turn over  30 four iron nails had different metals wrapped around them.    the nails were placed in an open dish filled with water and left for a week.    which iron nail has no protection against rusting?    a wrapped in aluminiumb wrapped in copper d wrapped in zinc c wrapped in magnesium      31 ammonia is made by the haber process.    n2  +  3h 2    2nh 3    what are the sources of the nitrogen and hydrogen used in the haber process?     nitrogen hydrogen  a fertilisers reacting methane with steam  b fertilisers the air  c the air reacting methane with steam  d the air the air      32 which process does not produce carbon dioxide?  a combustion of alkanes  b photosynthesis  c respiration  d thermal decomposition of limestone    ",
            "12": "12  \u00a9 ucles 2017 0620/21/o/n/17  33 which row shows the conditions used in the manufacture of sulfuric acid by the contact process?     temperature  / \u00b0c pressure  / atm catalyst  a 40 200 fe  b 40 200 v 2o5  c 400 2 fe  d 400 2 v 2o5     34 some marble chips (calcium carbonate) are heated strongly and substances x and y are formed.    substance x is a white solid that reacts with water, giving out heat. substance y is a colourless gas.    what are substances x and y?     x y  a calcium chloride oxygen  b calcium hydroxide carbon dioxide  c calcium oxide carbon dioxide  d calcium sulfate oxygen      35 the structures of some organic molecules are shown.    c c ch3h h3ch cch3 hhh c ch3 hcch3 hhh c h hcch3 hc h3h c h h2 13 4     which structures represent an alkane with four carbon atoms?  a 1 only b 2 and 3 c 2 and 4 d 3 and 4     ",
            "13": "13  \u00a9 ucles 2017 0620/21/o/n/17 [turn over  36 some of the fractions obtained from the fractio nal distillation of petroleum are used as fuels for  vehicles.    which two fractions are used as fuels for vehicles?  a bitumen fraction and gasoline fraction  b bitumen fraction and naphtha fraction  c gasoline fraction and kerosene fraction  d kerosene fraction and lubricating fraction    37 x, y and z are three hydrocarbons.    x ch 2=ch 2 y ch 3\u2013ch=ch 2 z ch 3\u2013ch 2\u2013ch=ch 2    what do compounds x, y and z have in common?    1 they are all alkenes.  2 they are all part of the same homologous series.  3 they all have the same boiling point.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      38 the diagram shows a reaction sequence.    butane ethene ethanolcarbon dioxide and waterxyz     which row names the processes x, y and z?     x y z  a cracking fermentation respiration  b cracking hydration combustion  c distillation fermentation respiration  d distillation hydration combustion     39 which pair of compounds can be used to prepare ch 3ch 2cooch 2ch 3?  a ethanoic acid and ethanol  b ethanoic acid and propanol  c propanoic acid and ethanol  d propanoic acid and propanol    ",
            "14": "14  \u00a9 ucles 2017 0620/21/o/n/17  40 the structure of a synthetic polymer is shown.    co co c co o n hn hn hn hco     the structure shows that it is a ..1.. . it is formed by ..2.. polymerisation.    which words complete gaps 1 and 2?     1 2  a polyamide addition  b polyamide condensation  c polyester addition  d polyester condensation     ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/21/o/n/17  blank page",
            "16": "16  \u00a9 ucles 2017 0620/21/o/n/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w17_qp_22.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 14 printed pages and 2 blank pages.  ib17 11_0620_22/3rp  \u00a9 ucles 2017 [turn over     *4951844726 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2 multiple choice (extended)  october/november 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.    ",
            "2": "2  \u00a9 ucles 2017 0620/22/o/n/17  1 the diagram shows the arrangement of particles in the three states of matter.    p q r    solid carbon dioxide (dry ice) su blimes to gaseous carbon dioxide.    which row describes the initial and final states?     initial  state final  state  a p r  b q p  c r p  d r q     2 during an experiment a measurement is recorded in cm 3.    which apparatus is used?  a balance  b measuring cylinder  c stopclock  d thermometer     3 a student carried out paper chromatography on a mixture of amino acids.    the student sprayed the dried chromatogram with a locating agent.    what is the function of the locating agent?  a to dissolve the amino acids  b to form coloured spots with the amino acids  c to preserve the amino acids  d to stop the amino acids reacting     ",
            "3": "3  \u00a9 ucles 2017 0620/22/o/n/17 [turn over  4 which row describes silicon( iv) oxide?     has a  giant structure is an  acidic oxide conducts  electricity  a \u0016 \u0016 \u0016  b \u0016 \u0016 \u001a  c \u0016 \u001a \u001a  d \u001a \u0016 \u0016      5 why do isotopes of the same element have the same chemical properties?  a they have the same nucleon number.  b they have the same number of electrons in the outer shell.  c they have the same number of neutrons in the nucleus.  d they have the same number of protons as neutrons.      6 which dot-and-cross diagram shows the outer shell electron arrangement in a molecule of  carbon dioxide?    o ca o o cbo o cco o cdo      ",
            "4": "4  \u00a9 ucles 2017 0620/22/o/n/17  7 the equation for the reaction between phosphorus and oxygen is shown.    xp4  +  yo2  \u2192  zp2o5    which values of x, y and z balance the equation?     x y z  a 1 5 2  b 1 10 2  c 2 5 2  d 2 10 1      8 the relative molecular mass of an alcohol is 88.    its percentage composition by mass is: c, 54.5%;  h, 9.1%;  o, 36.4%.    which row shows the empirical formula and molecular formula for this alcohol?     empirical formula molecular formula  a c2h4o c 2h4o  b c2h4o c 4h8o2  c c4h8o2 c 4h8o2  d c4h8o2 c 2h4o      9 which statements about the electrolysis of concentrated copper( ii) chloride are correct?    1 electrons are transferred from the cathode to the copper( ii) ions.  2 electrons move round the external circuit from the cathode to the anode.  3 chloride ions are attracted to the anode. 4 hydroxide ions transfer electrons to the cathode.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "5": "5  \u00a9 ucles 2017 0620/22/o/n/17 [turn over  10 which metal combination produces the highest voltage reading in the cells shown?    va fe cuvb zn cu vc cu cuvd mg cu      11 the equation for the combustion of methane is shown.    ch 4  +  2o 2  \u2192  co 2  +  2h 2o    the energy change for the combustion of methane is \u2013890  kj / mol.    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013h +410  o=o +496  h\u2013o +460    what is the bond energy of the c=o bond?  a +49  kj / mol b +841  kj / mol c +1301  kj / mol d +1335  kj / mol    ",
            "6": "6  \u00a9 ucles 2017 0620/22/o/n/17  12 which statement describes an exothermic reaction?  a the energy absorbed for bond breaking is greater than the energy released by bond  formation.  b the energy absorbed for bond breaking is less than the energy released by bond formation.  c the energy released by bond breaking is greater than the energy absorbed for bond  formation.  d the energy released by bond breaking is less than the energy absorbed for bond formation.    13 the mass of a beaker and its contents is plotted against time.    which graph represents what happens when sodium carbonate reacts with an excess of dilute  hydrochloric acid in an open beaker?    mass  time a mass  time b mass  time c mass  time d 00000000      14 copper metal donates electrons to silver ions.    zinc metal donates electrons to copper ions.    what is the strongest reducing agent?  a copper ions  b copper metal  c silver ions  d zinc metal      15 four statements about the effect of increasing temperature on a reaction are shown.    1 the activation energy becomes lower.  2 the particles move faster.  3 there are more collisions between reacting particles.  4 there are more collisions which have energy greater than the activation energy.    which statements are correct?  a 1, 2 and 3 b 1, 3 and 4 c 2, 3 and 4 d 2 and 3 only    ",
            "7": "7  \u00a9 ucles 2017 0620/22/o/n/17 [turn over  16 the formation of sulfur trioxide from sulfur dioxide is a reversible reaction.    2so 2(g)  +  o 2(g)    2so 3(g)    the forward reaction is exothermic.    which changes would increase the equilibrium yield of so 3?    1 increasing the pressure  2 lowering the temperature  3 decreasing the concentration of oxygen    a 1, 2 and 3 b 1 and 2 only c 1 only d 2 and 3 only     17 some properties of four oxides are listed.    oxide 1 reacts with both acids and alkalis to form salts.    oxide 2 reacts with acids to form sa lts but does not react with alkalis.    oxide 3 reacts with alkalis to form salts but does not react with acids.    oxide 4 does not react with acids or alkalis.    which row describes the oxides?     oxide 1 oxide 2 oxide 3 oxide 4  a amphoteric acidic basic neutral  b amphoteric basic acidic neutral  c neutral acidic basic amphoteric  d neutral basic acidic amphoteric      18 what is not a typical characteristic of acids?  a they react with alkalis producing water.  b they react with all metals producing hydrogen.  c they react with carbonates producing carbon dioxide.  d they turn blue litmus paper red.    ",
            "8": "8  \u00a9 ucles 2017 0620/22/o/n/17  19 copper( ii) sulfate can be prepared by adding excess copper( ii) carbonate to sulfuric acid.    why is an excess  of copper( ii) carbonate added?  a to ensure all the copper( ii) carbonate has reacted  b to ensure all the sulfuric acid has reacted  c to increase the rate of reaction  d to increase the yield of copper( ii) sulfate     20 compound p reacts with hydrochloric acid to produce a gas that turns limewater milky.    what is p?  a sodium carbonate  b sodium chloride  c sodium hydroxide  d sodium sulfate      21 which statement about nitrogen and phosphorus is not correct?  a both are in the same group of the periodic table.  b both are in the same period of the periodic table.  c both are non-metals.  d both have the same number of electrons in their outer shell.      22 sodium and rubidium are elements in group i of the periodic table.    which statement is correct?  a sodium atoms have more electrons than rubidium atoms.  b sodium has a lower density than rubidium.  c sodium has a lower melting point than rubidium.  d sodium is more reactive than rubidium.    23 which properties do the elements chromium, iron and vanadium have in common?    1 they all conduct electricity.  2 they, or their compounds, can act as catalysts.  3 they all form coloured compounds.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only   ",
            "9": "9  \u00a9 ucles 2017 0620/22/o/n/17 [turn over  24 why is argon gas used to fill electric lamps?  a it conducts electricity.  b it glows when heated.  c it is less dense than air.  d it is not reactive.      25 what is a property of all metals?  a conduct electricity  b hard  c low melting points  d react with water      26 aluminium is extracted from bauxite by electrolysis.    which row shows the anode material and the anode reaction?     anode material anode reaction  a carbon a l 3+  +  3e\u2013  \u2192  a l  b carbon 2o2\u2013  \u2192  o 2  +  4e\u2013  c steel a l 3+  +  3e\u2013  \u2192  a l  d steel 2o2\u2013  \u2192  o 2  +  4e\u2013      27 which statement about the metal zinc is not correct?  a it forms an oxide more readily than iron.  b it is manufactured by the electrolysis of zinc blende.  c it is used to make brass.  d it is used to prevent iron from rusting.     28 calcium nitrate decomposes when it is heated.    what is the equation for the thermal decomposition of calcium nitrate?  a 2ca(no 3)2  \u2192  2cao  +  o 2  + 4no 2  b ca(no 3)2  \u2192  ca(no 2)2  +  o 2  c ca(no 3)2  \u2192  ca  +  o 2  +  2no 2  d ca(no 3)2  \u2192  ca  +  3o 2  +  n 2     ",
            "10": "10  \u00a9 ucles 2017 0620/22/o/n/17  29 the flow chart shows stages in the treatment of river water to produce drinking water.    drinking waterstage ystage xsettling tankriver water    what occurs at stages x and y?     x y  a distillation chlorination  b distillation filtration  c filtration chlorination  d filtration distillation      30 an experiment to investigate the effect of galvanising iron is shown.    airpure iron galvanised iron waterxy     the experiment is left for seven days.    what happens to the water level in tubes x and y?     tube x tube y  a falls rises  b no change no change  c rises falls  d rises no change      31 which metal is used as a catalyst in the haber process for the manufacture of ammonia?  a iron  b nickel  c platinum  d vanadium    ",
            "11": "11  \u00a9 ucles 2017 0620/22/o/n/17 [turn over  32 which process removes carbon dioxide from the atmosphere?  a combustion of fossil fuels  b decomposition of carbonates  c photosynthesis  d respiration      33 which row shows the conditions used in the manufacture of sulfuric acid by the contact process?     temperature  / \u00b0c pressure  / atm catalyst  a 40 200 fe  b 40 200 v 2o5  c 400 2 fe  d 400 2 v 2o5      34 some marble chips (calcium carbonate) are heated strongly and substances x and y are formed.    substance x is a white solid that reacts with water, giving out heat. substance y is a colourless gas.    what are substances x and y?     x y  a calcium chloride oxygen  b calcium hydroxide carbon dioxide  c calcium oxide carbon dioxide  d calcium sulfate oxygen      35 the structures of four organic compounds are shown.    hc hh c hhhhs hh c c h hc hh c hht hc hh c hhv hc ch c chu h h h hh     which compounds are unsaturated?  a s only b t and u c u only d v only   ",
            "12": "12  \u00a9 ucles 2017 0620/22/o/n/17  36 which statement is not correct?  a petroleum is a mixture of hydrocarbons.  b the main constituent of natural gas is ethane.  c the naphtha fraction of petroleum is used for making chemicals.  d when natural gas burns in air, carbon dioxide and water are formed.      37 x, y and z are three hydrocarbons.    x ch 2=ch 2 y ch 3\u2013ch=ch 2 z ch 3\u2013ch 2\u2013ch=ch 2    what do compounds x, y and z have in common?    1 they are all alkenes.  2 they are all part of the same homologous series. 3 they all have the same boiling point.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    38 the diagram shows a reaction sequence.    butane ethene ethanolcarbon dioxide and waterxyz     which row names the processes x, y and z?     x y z  a cracking fermentation respiration  b cracking hydration combustion  c distillation fermentation respiration  d distillation hydration combustion     ",
            "13": "13  \u00a9 ucles 2017 0620/22/o/n/17 39 the structure of an ester is shown.    c o c h ch hh o hhhhh c c h     which substances react to form this ester?  a ethanol and ethanoic acid  b ethanol and propanoic acid  c propanol and ethanoic acid  d propanol and propanoic acid    40 a polymer can be made from methyl propene.    cch hch3 ch3    which diagram shows the structure of the polymer?    ch hcch3 ch3ca h hcch3 ch3ch hcch3 ch3 h hch3 ch3h hch3 ch3h hch3 ch3ch ch ch3cb h ch ch3ch ch ch3 ch3 ch3 ch3 ch cch3 cc h c ch cch3 hc h3 hh ch3ch3 ch3cc cd c cc      ",
            "14": "14    blank page   \u00a9 ucles 2017 0620/22/o/n/17  ",
            "15": "15    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/22/o/n/17  ",
            "16": "16  \u00a9 ucles 2017 0620/22/o/n/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w17_qp_23.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib17 11_0620_23/3rp  \u00a9 ucles 2017 [turn over     *7280088800 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/23     paper 2 multiple choice (extended)  october/november 2017       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.    ",
            "2": "2  \u00a9 ucles 2017 0620/23/o/n/17  1 which statement describes sublimation?  a particles moving slowly past each other speed up and move further apart.  b particles vibrating next to each other become mobile and move slowly past each other.  c particles vibrating next to each other start to move rapidly and move further apart.  d rapidly moving particles slow down and move closer together.      2 25  cm3 of an alkali are added to 20  cm3 of an acid. the temperature change is measured.    which apparatus is not needed in the experiment?  a 25  cm3 measuring cylinder  b 100  cm3 beaker  c balance  d thermometer    3 the painkiller paracetamol is synthesised from 4-aminophenol.    chromatography was carried out on an impure sample of paracetamol. the results are shown  (not drawn to scale).    p s0.35  cm 0.26  cm 0.17  cmsolvent front baselinekey ps = pure paracetamol= impure sample of paracetamol     the sample of paracetamol was contaminated with 4-aminophenol only.    what is the rf value of 4-aminophenol?  a 0.49 b 0.65 c 0.74 d 1.35     ",
            "3": "3  \u00a9 ucles 2017 0620/23/o/n/17 [turn over  4 which compound is silicon( iv) oxide?     melting point  / \u00b0c good electrical  conductor when solid good electrical  conductor when molten  a \u201373 no no  b 801 no yes  c 1495 yes yes  d 1710 no no      5 carbon has three naturally occurring isotopes, 12c, 13c and 14c.    which statement explains why the isotopes have the same chemical properties?  a they have the same number of electrons in the first shell.  b they have the same number of electrons in the outer shell.  c they have the same number of neutrons in the nucleus.  d they have the same number of protons as neutrons.    6 which dot-and-cross diagram shows the outer shell electron arrangement in a molecule of  carbon dioxide?    ca oo cb oo cc oo cd oo      7 the equation represents the reaction between solid magnesium oxide and dilute  hydrochloric acid to form magnesium chloride and water.    mgo  +  2hc l  \u2192  mgc l  2  +  h 2o    which row shows the state symbols for hydrochloric acid, magnesium chloride and water?     hc l mgc l 2 h2o  a (aq) (aq) (l)  b (aq) (l) (l)  c (l) (aq) (aq)  d (l) (l) (aq)     ",
            "4": "4  \u00a9 ucles 2017 0620/23/o/n/17  8 a compound contains 34.5% calcium, 24.1% silicon and 41.4% oxygen by mass.    what is its empirical formula?  a ca 2sio 3 b casio 3 c casi 2o3 d casio 6     9 which statements about the electrolysis of concentrated copper( ii) chloride are correct?    1 electrons are transferred from the cathode to the copper( ii) ions.  2 electrons move round the external circuit from the cathode to the anode.  3 chloride ions are attracted to the anode. 4 hydroxide ions transfer electrons to the cathode.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    10 which metal combination produces the highest voltage reading in the cells shown?    va fe cuvb zn cu vc cu cuvd mg cu      ",
            "5": "5  \u00a9 ucles 2017 0620/23/o/n/17 [turn over  11 some bond energies are shown in the table.  bond   bond energy  in kj / mol  h\u2013h +436  o=o +496  h\u2013o +460    hydrogen reacts with oxygen. the reaction is exothermic.    2h2(g)  +  o 2(g)  \u2192  2h 2o(g)    what is the energy change for the reaction?  a \u20133208  kj / mol  b \u2013908  kj / mol  c \u2013472  kj / mol  d \u2013448  kj / mol     12 which statement describes an exothermic reaction?  a the energy absorbed for bond breaking is greater than the energy released by bond  formation.  b the energy absorbed for bond breaking is less than the energy released by bond formation.  c the energy released by bond breaking is greater than the energy absorbed for bond  formation.  d the energy released by bond breaking is less than the energy absorbed for bond formation.    13 the mass of a beaker and its contents is plotted against time.    which graph represents what happens when sodium carbonate reacts with an excess of dilute hydrochloric acid in an open beaker?    mass  time a mass  time b mass  time c mass  time d 00000000      ",
            "6": "6  \u00a9 ucles 2017 0620/23/o/n/17  14  silver chloride reacts when it is exposed to light.    which row shows what happens to the silver in this process?     half-equation type of reaction  a ag  \u2192  ag+  +  e\u2013 oxidation  b ag  \u2192  ag+  +  e\u2013 reduction  c ag+  +  e\u2013  \u2192  ag oxidation  d ag+  +  e\u2013  \u2192  ag reduction     15 which statement about the effect of concentration and temperature on the rate of a reaction is  not correct?  a if the concentration of a reactant is increased, the rate of reaction increases because more  particles have sufficient energy to react.  b if the concentration of a reactant is increased, the rate of reaction increases because there  are more collisions between particles per second.  c if the temperature is increased, the rate of reaction increases because there are more  collisions between particles per second.  d if the temperature is increased, the rate of reaction increases because more particles have  sufficient energy to react.     16 the following reaction has reached equilibrium in a closed system.    2so 2(g)  +  o 2(g)    2so 3(g)    the forward reaction is exothermic.    which row shows the effect of increasing the pressure on the equilibrium mixture?     reaction rate amount of so 2 amount of so 3  a increases decreases increases  b increases increases decreases  c unchanged decreases increases  d unchanged increases decreases     ",
            "7": "7  \u00a9 ucles 2017 0620/23/o/n/17 [turn over  17 some properties of four oxides are listed.    oxide 1 reacts with both acids and alkalis to form salts.    oxide 2 reacts with acids to form sa lts but does not react with alkalis.    oxide 3 reacts with alkalis to form salts but does not react with acids.    oxide 4 does not react with acids or alkalis.    which row describes the oxides?     oxide 1 oxide 2 oxide 3 oxide 4  a amphoteric acidic basic neutral  b amphoteric basic acidic neutral  c neutral acidic basic amphoteric  d neutral basic acidic amphoteric     18 what is not a typical characteristic of acids?  a they react with alkalis producing water.  b they react with all metals producing hydrogen.  c they react with carbonates producing carbon dioxide.  d they turn blue litmus paper red.     19 three solids, p, q and r, all react with dilute sulfuric acid to produce zinc sulfate.    p and r produce gases during the reaction.    the gas produced when p reacts will not burn. the gas produced when r reacts will burn.    what are p, q and r?     p q r  a zinc zinc hydroxide zinc carbonate  b zinc carbonate zinc zinc oxide  c zinc carbonate zinc hydroxide zinc  d zinc oxide zinc carbonate zinc      20 which ion forms a green precipitate with aqueous sodium hydroxide that dissolves in an excess  of aqueous sodium hydroxide?  a ca2+ b cr3+ c cu2+ d fe2+    ",
            "8": "8  \u00a9 ucles 2017 0620/23/o/n/17  21 a period of the periodic table is shown.    group i ii iii iv v vi vii viii  element r s t v w x y z    the letters are not their chemical symbols.    which statement is correct?  a element r does not conduct electricity.  b elements r and y react together to form an ionic compound.  c element z exists as a diatomic molecule.  d element z reacts with element t.      22 some properties of element x are shown.    melting point   in  \u00b0c 98  boiling point   in  \u00b0c 883  reaction with cold water gives off h 2 gas  reaction when heated with oxygen burns to give a white solid    in which part of the periodic table is x found?  a group i  b group vii  c group viii  d transition elements    ",
            "9": "9  \u00a9 ucles 2017 0620/23/o/n/17 [turn over  23 the table gives some properties of an element.    melting point in \u00b0c 3422  appearance of the element grey  appearance of the chloride of the element dark blue  density in g  / cm3 19.2  electrical conductivity when solid good    which other property would you expect this element to have?  a acts as a catalyst  b brittle  c forms an acidic oxide  d highly reactive with water     24 why is argon gas used to fill electric lamps?  a it conducts electricity.  b it glows when heated.  c it is less dense than air.  d it is not reactive.     25 what is a property of all metals?  a conduct electricity  b hard  c low melting points  d react with water    26 aluminium is obtained by the electrolysis of a mixture of aluminium oxide and cryolite.    why is cryolite used?  a as a catalyst to speed up the process  b as a coolant to prevent the process getting too hot  c as a solvent for aluminium oxide  d as the main source of aluminium ions    ",
            "10": "10  \u00a9 ucles 2017 0620/23/o/n/17  27 metal m is mixed with copper to produce brass.    what is m?  a chromium  b nickel  c vanadium  d zinc    28 some metal nitrates and carbonates decompose when heated strongly.    metal q has a nitrate that decomposes to give a salt and a colourless gas only.    the carbonate of metal q does not decompose when heated with a bunsen burner.    what is metal q?  a calcium  b copper  c sodium  d zinc    29 the flow chart shows stages in the treatment of river water to produce drinking water.    drinking waterstage ystage xsettling tankriver water    what occurs at stages x and y?     x y  a distillation chlorination  b distillation filtration  c filtration chlorination  d filtration distillation     ",
            "11": "11  \u00a9 ucles 2017 0620/23/o/n/17 [turn over  30 a piece of zinc is attached to the hull of a steel boat. steel is an alloy of iron.    which statement explains why the zinc prevents the iron from rusting?  a zinc is less reactive than iron, and iron is less likely to lose electrons than zinc.  b zinc is less reactive than iron, and iron is more likely to lose electrons than zinc.  c zinc is more reactive than iron, and iron is less likely to lose electrons than zinc.  d zinc is more reactive than iron, and iron is more likely to lose electrons than zinc.     31 the haber process for making ammonia is carried out at a temperature of 450  \u00b0c and a pressure  of 200 atmospheres in the presence of a catalyst.    which statement is not correct?  a lowering the pressure increases the rate at which ammonia is produced.  b lowering the temperature slows down the rate at which ammonia is produced.  c maintaining a very high pressure is very difficult and needs expensive equipment.  d the reaction is a reversible reaction which can proceed forwards and backwards.      32 which process does not produce carbon dioxide?  a combustion of methane  b photosynthesis  c respiration  d thermal decomposition of calcium carbonate      33 which row shows the conditions used in the manufacture of sulfuric acid by the contact process?     temperature  / \u00b0c pressure  / atm catalyst  a 40 200 fe  b 40 200 v 2o5  c 400 2 fe  d 400 2 v 2o5     ",
            "12": "12  \u00a9 ucles 2017 0620/23/o/n/17  34 some marble chips (calcium carbonate) are heated strongly and substances x and y are formed.    substance x is a white solid that reacts with water, giving out heat. substance y is a colourless gas.    what are substances x and y?     x y  a calcium chloride oxygen  b calcium hydroxide carbon dioxide  c calcium oxide carbon dioxide  d calcium sulfate oxygen      35 the structure of compound r is shown.    co h h ch hhh chh     what is r?  a propane  b propanoic acid  c propanol  d propene    36 fuel oil and naphtha are two fractions obtained from petroleum.    what are the major uses of these fractions?     fuel oil naphtha  a jet fuel making chemicals  b jet fuel making roads  c ship fuel making chemicals  d ship fuel making roads     ",
            "13": "13  \u00a9 ucles 2017 0620/23/o/n/17 [turn over  37 x, y and z are three hydrocarbons.    x ch 2=ch 2 y ch 3\u2013ch=ch 2 z ch 3\u2013ch 2\u2013ch=ch 2    what do compounds x, y and z have in common?    1 they are all alkenes.  2 they are all part of the same homologous series. 3 they all have the same boiling point.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    38 the diagram shows a reaction sequence.    butane ethene ethanolcarbon dioxide and waterxyz     which row names the processes x, y and z?     x y z  a cracking fermentation respiration  b cracking hydration combustion  c distillation fermentation respiration  d distillation hydration combustion     39 the structure of an ester is shown.    ch hh cco oh h ch hch hch hchh h    which combination of carboxylic acid and alcohol produces this ester?     carboxylic acid alcohol  a butanoic acid ethanol  b butanoic acid propanol  c ethanoic acid butanol  d propanoic acid butanol     ",
            "14": "14  \u00a9 ucles 2017 0620/23/o/n/17  40 the equation shows the formation of a polymer called kevlar .    hooc cooh co c+ n h2nn h2 n no n hnh\u2013 h2o     which row describes kevlar ?     how the polymer is formed type of polymer  a addition polymerisation polyamide  b addition polymerisation polyester  c condensation polymerisation polyamide  d condensation polymerisation polyester     ",
            "15": "15    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2017 0620/23/o/n/17 ",
            "16": "16  \u00a9 ucles 2017 0620/23/o/n/17   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w17_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31   paper 3 theory (core) october/november 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib17 11_0620_31/3rp\u00a9 ucles 2017 *8786129582* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/31/o/n/17 \u00a9 ucles 2017 1\t\tthe\tdiagram\tshows\tthe\tstructures\tof\tfive\tsubstances,\ta,\tb,\tc,\td\tand\te. ab dec br br ch c hh hch cbr br hh hna+br \u2013na+br \u2013 na+br \u2013na+br \u2013br \u2013na+na+br \u2013f ff br \t\tanswer\tthe\tfollowing\tquestions\tusing\tonly\tthe\tstructures\tin\tthe\tdiagram. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall.  (a)\t\twhich\tstructure,\ta,\tb,\tc,\td or e,  (i)\t\tis\ta\tdiatomic\tmolecule,\t  .   [1]  (ii)\t\tcontains\tions,\t    [1]  (iii)\t\tdecolourises\taqueous\tbromine,\t     [1]  (iv)\t\tconducts\telectricity\twhen\tmolten,\t  .   [1]  (v)\t\tcontains\tatoms\tof\ttwo\tdifferent\thalogens?\t ...   [1]  (b)\t\tbromine\tis\tan\telement. \t\twhat\tis\tmeant\tby\tthe\tterm\telement ?      ..   [1]  (c)\t bromine\tmelts\tat\t\u20137\t \u00b0c\tand\tboils\tat\t59\t \u00b0c. \t\twhat\tis\tthe\tphysical\tstate\tof\tbromine\tat\t\u201315\t \u00b0c? \t\texplain\tyour\tanswer.      ..   [2] [total:\t8]",
            "3": "3 0620/31/o/n/17 \u00a9 ucles 2017 [turn over 2\t\tthe\ttable\tshows\tthe\tcomposition\tof\tthe\tatmosphere\tof\tthe\tplanet\tneptune. gas\tpresentpercentage\tof\tgas\tin neptune\u2019s\tatmosphere helium 19.5 hydrogen 78.8 methane other gases 0.2  (a)\t\tcomplete\tthe\ttable\tto\tcalculate\tthe\tpercentage\tof\tmethane\tin\tneptune\u2019s\tatmosphere.\t [1]  (b)\t\tdescribe\thow\tneptune\u2019s\tatmosphere\tdiffers\tfrom\tthe\tearth\u2019s\tatmosphere. \t\tgive\tthree\tdifferences.  1  .     2  .     3  .    [3]  (c)\t\tmethane\tis\ta\tcovalent\tcompound. \t\tcomplete\tthe\tdiagram\tto\tshow \t \u25cf\t \tthe\tarrangement\tof\telectrons\tin\ta\tmolecule\tof\tmethane, \t \u25cf\t \tthe\tsymbols\tof\tthe\tatoms\tpresent. \t\tshow\touter\tshell\telectrons\tonly. [2]",
            "4": "4 0620/31/o/n/17 \u00a9 ucles 2017  (d)\t\tisotopes\tof\thydrogen\tare\tpresent\tin\tneptune\u2019s\tatmosphere.  (i)\t\twhat\tis\tmeant\tby\tthe\tterm\tisotopes ?   .   ...   [1]  (ii)\t\tan\tatom\tof\thydrogen\thas\tthree\tnucleons. \t \tdeduce\tthe\tnumber\tof\tprotons\tand\tneutrons\tpresent\tin\tone atom of this isotope of  hydrogen. \t \tuse\tyour\tperiodic\t table\tto\thelp\tyou. \t number\tof\tprotons\t .. \t number\tof\tneutrons\t   [2]  (e)\t\tother\tgases\tpresent\tin\tneptune\u2019s\tatmosphere\tinclude\tethane\tand\twater\tvapour.  (i)\t\tcalculate\tthe\trelative\tmolecular\tmass\tof \tethane,\tc2h6. \t \tuse\tyour\tperiodic\t table\tto\thelp\tyou. relative\tmolecular\tmass\t=\t..\t\t[2]  (ii)\t\tdescribe\ta\t chemical\ttest\tfor\twater.  test  .. \t result\t ... [2] [total:\t13]",
            "5": "5 0620/31/o/n/17 \u00a9 ucles 2017 [turn over 3\t\tthe\tfollowing\tsubstances\tare\tpresent\tin\ta\tliquid\t floor\tcleaner. coloured\tdyes ethanol preservatives sodium\tcarbonate  (a) (i)\t\tbalance\tthe \tchemical\tequation\tfor\tthe\tcomplete\tcombustion\tof\tethanol. c2h5oh  +  3o2    ..co2  +  ..h2o [2]  (ii)\t\tdraw\tthe\tstructure\tof\tan\tethanol\tmolecule\tshowing\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds. [2]  (b)\t\taqueous\tsodium\tcarbonate\tis\talkaline.  (i)  which one\tof\tthe\tfollowing\tph\tvalues\tis \talkaline? \t \tput\ta\tcircle\taround\tthe\tcorrect\tanswer. ph\t3\t\t\t\t\t\t\t\t\t\tph\t 6\t\t\t\t\t\t\t\t\t\tph\t 7\t\t\t\t\t\t\t\t\t\tph\t 10 [1]  (ii)\t\taqueous\tsodium\tcarbonate\tis\tcolourless. \t \tan\texcess\tof\taqueous\tsodium\tcarbonate\t is\tadded\tto\ta\tsolution\tof\tdilute\tsulfuric\tacid\tand\t methyl\torange. \t \tdescribe\tthe\tcolour\tchange.  from .. to  ...   [2]  (iii)\t\tthe\tchemical\tequation\tfor\tthe\treaction\tbetween\tsodium\tcarbonate\t and\tdilute\tsulfuric\tacid\t is\tshown. na2co3  +  h2so4  \t\tna2so4  +  co2  +  h2o \t \twrite\tthe\tword\tequation\tfor\tthis\treaction.   ...   [2]",
            "6": "6 0620/31/o/n/17 \u00a9 ucles 2017  (c)\t\tpreservatives\tstop\tthe\tgrowth\tof\tbacteria\tand\tfungi. \t\tstate\tthe\tname\tof\tan\tacidic\tgas\tused\tto\tpreserve\tfood.   ..   [1]  (d)\t\tthe\tcoloured\tdyes\tin\tthe\tliquid\tfloor\tcleaner\tcan\tbe \tseparated\tusing\tthe\tapparatus\tshown. p . . q ..  (i)\t\tcomplete\tthe\tboxes\tto\tlabel\t p\tand\tq. [2]       (ii)\t\tstate\tthe\tname\tof\tthis\tmethod\tof\tseparation.   ...   [1]  (iii)\t\ton\tthe\tdiagram,\tput\tan\tx\tto\tshow\twhere\tthe\tmixture\tof\tcoloured\tdyes\tis\tplaced\tat\tthe\tstart\t of\tthe\texperiment.\t [1] [total:\t14]",
            "7": "7 0620/31/o/n/17 \u00a9 ucles 2017 [turn over 4\t\tthe\ttable\tshows\tthe\tproperties\tof\tfour\tsubstances. substance boiling\tpointelectrical conductivity of\tsolidelectrical\t conductivity when\tmoltendensity in\tg\t/\tcm3 graphite 2.25 iodine low does\tnot\tconduct does\tnot\tconduct 4.93 potassium high conducts 0.86 zinc\tchloride high does\tnot\tconduct conducts 2.91  (a)\t\tcomplete\tthe\ttable\tto\tshow\tthe\telectrical\tconductivity\tof\tsolid\tgraphite\tand\tsolid\tpotassium. [2]  (b)\t\tgive\t one\tpiece\tof\tevidence\tfrom\tthe\ttable\tthat\tshows\tthat\tiodine\tis\ta\tsimple\tcovalent\tsubstance.   ..   [1]  (c)\t\twhat\tinformation\tin\tthe\ttable\tshows\tthat\tzinc\tchloride\tis\tan\tionic\tcompound?      ..   [2]  (d)\t\tmolten\tzinc\tchloride\tcan\tbe\telectrolysed. \t\tpredict\tthe\tproducts\tof\tthis\telectrolysis\tat \t the\tpositive\telectrode\t(anode),\t  .. \t the\tnegative\telectrode\t(cathode).\t  .. [2]  (e)\t\taqueous\tiodine\tis\tformed\twhen\taqueous\tchlorine\tis \tadded\tto\taqueous\tpotassium\tiodide. \t\tuse\tideas\tabout\treactivity\tto\texplain\twhy\tthis\treaction\toccurs.      ..   [1] [total:\t8]",
            "8": "8 0620/31/o/n/17 \u00a9 ucles 2017 5\t\ttitanium\tis\textracted\tfrom\tan\tore\twhich\tcontains \ttitanium( iv)\toxide,\ttio2.  (a) (i)\t\tbalance\tthe \tchemical\tequation\tfor\tthe\tfirst\tstep\tin\tthis\textraction. tio2  +  ..c  +  ..c l 2    tic l 4  +  2co [2]  (ii)\t\texplain\twhy\tthe\tconversion\tof\tcarbon\tto \tcarbon\tmonoxide\tis\tan\toxidation\treaction.   ...   [1]  (b)\t\ttitanium\tis\ta\ttransition\telement. \t\tsodium\tis\ta\tgroup\ti\telement. \t\tdescribe\t two\tdifferences\tin\tthe\tphysical\tproperties\tof\ttitanium\tand\tsodium.  1  .     2  .    [2]  (c)\t\tthe\tproperties\t and\trelative\treactivity\twith\twater\tof\tsome\tgroup\ti\telements\t are\tshown\tin\tthe\t table. element density\tin\tg\t /\tcm3melting\tpoint\tin\t \u00b0crelative\treactivity\twith\twater lithium 0.53 181 sodium 98forms\tbubbles\trapidly but\tdoes\tnot\tburst\tinto\tflames potassium 0.86forms\tbubbles\tvery\trapidly and\tbursts\tinto\tflames rubidium 1.53 39 reacts\texplosively  (i)\t\tcomplete\tthe\ttable \t \u25cf\t\tfor\tthe\trelative\treactivity\tof\tlithium\twith\twater, \t \u25cf\t\tto\tpredict\tthe\tmelting\tpoint\tof\tpotassium.  [2]  (ii)\t\tdescribe\tthe\tgeneral\ttrend\tin\tthe\tdensity \tof\tthe\tgroup\ti\telements.   ...   [1]  (d)\t\tis\tlithium\toxide\tan\tacidic\toxide\tor\ta\tbasic\toxide? \t\texplain\tyour\tanswer.      ..   [1] [total:\t9]",
            "9": "9 0620/31/o/n/17 \u00a9 ucles 2017 [turn over 6\t\tthe\tdiagram\tshows\ta\tfractionating\tcolumn\tused\t for\tthe\tfractional\tdistillation\tof\tpetroleum. kerosene fractionnaphtha fractiongasoline fractionrefinery gas diesel oil fraction fuel oil fraction lubricating fraction and bitumen  (a)\t\tdescribe\tthe\tfractional\tdistillation\tof\tpetroleum. \t\tin\tyour\tanswer,\tinclude \t \u25cf\t \twhere\tthe\tpetroleum\tenters\tthe\tfractionating\tcolumn, \t \u25cf\t \tthe\trelative\ttemperatures\tin\tthe\tfractionating\tcolumn\t(higher\tor\tlower), \t \u25cf\t \tthe\trelative\tboiling\tpoints\tof\tthe\tfractions \t(higher\tor\tlower), \t \u25cf\t \tthe\tchanges\tin\tphysical\tstate\twhich\toccur.                     ..   [4]",
            "10": "10 0620/31/o/n/17 \u00a9 ucles 2017  (b)\t\talkenes\tcan\tbe\tmade\tby\tcracking\tthe\tkerosene\tfraction.  (i)\t\twhat\tis\tmeant\tby\tthe\tterm\tcracking ?   .   ...   [2]  (ii)\t\twhen\tbutane\tis\tcracked,\tethene\tand\tgas\tx are produced. c4h10    2c2h4  +  x \t \tstate\tthe\tname\tof\tgas\tx.   ...   [1]  (c)\t\tcomplete\tthe\tsentence\tabout\tthe\tbonding\tin\tbutane. \t\tall\tthe\tbonds\tin\tbutane\tare\tsingle\t\tchemical\tbonds.\t [1]  (d)\t\tethene\tis\tused\tto\tmake\tpoly(ethene).   which one\tof\tthe\tfollowing\twords\tdescribes\tpoly(ethene)? \t\tput\ta\tcircle\taround\tthe\tcorrect\tanswer. gas               monomer               polymer               solvent [1] [total:\t9]",
            "11": "11 0620/31/o/n/17 \u00a9 ucles 2017 [turn over 7\t\tbromine\tis\ta\tred-brown\tliquid\twhich\tis\tsoluble\tin\t cyclohexane.  (a)\t\ta\tfew\tdrops\tof\tliquid\tbromine\twere\tplaced\tat\tthe\tbottom\tof\ta\tbeaker\tcontaining\tcyclohexane. \t\tafter\t3\tdays,\ta\tred-brown\tcolour\thad\tspread\tthroughout\tthe\tbeaker. at the start after 6 hours after 3 dayscyclohexane bromine \t\texplain\tthese\tobservations\tusing\tthe\tkinetic\tparticle\tmodel.               ..   [3]  (b)\t\tthe\tstructure\tof\ta\tcompound\tcontaining\tbromine\tis\t shown. hc hbr brch cco o h hh  (i)\t\tdeduce\tthe\tmolecular\t formula\tof\tthis\tcompound\t showing\tthe\tnumber\tof\tcarbon,\thydrogen,\t oxygen\tand\tbromine\tatoms.   ...   [1]  (ii)\t\tstate\tthe\tname\tof\tthe\t co oh\tfunctional\tgroup.   ...   [1]",
            "12": "12 0620/31/o/n/17 \u00a9 ucles 2017  (c)\t\tthe\trelative\tatomic\tmass\tof\tbromine\tis\t80. \t\tcomplete\tthe\tdefinition\tof\trelative\tatomic\tmass\tusing\tterms\tfrom\tthe\tlist. 6 12 an atom an element a molecule average carbon hydrogen total \t\trelative\tatomic\tmass\tis\tthe\t\tmass\tof\tnaturally\toccurring\tatoms\t     of\t\ton\ta\tscale\twhere\t\tof\tthe\t12c isotope has    a\tmass\tof\texactly\t\tunits.\t [4]  (d)\t\tdilute\thydrobromic\tacid\treacts\twith\tmagnesium\tribbon.  (i)  suggest three\tways\tof\tincreasing\tthe\trate\tof\tthis\treaction.  1  ..  2  ..  3  .. [3]  (ii)\t\thydrobromic\tacid\treacts\twith\toxygen.\t the\tproducts\tare\twater\tand\tbromine. \t \tbalance\tthe\tchemical\tequation\tfor\tthis\treaction. ..hbr  +  o 2    2h2o  +  2br2 [1] [total:\t13]",
            "13": "13 0620/31/o/n/17 \u00a9 ucles 2017 [turn over 8\t\tammonia\t is\tmanufactured\t by\tcombining\t nitrogen\tand\thydrogen\t at\thigh\ttemperature\t and\tpressure. \t catalyst nitrogen\t\t+\t\thydrogen\t\t \t\tammonia  (a) (i)\t\twhat\tis\tthe\tmeaning\tof\tthe\tsymbol\t ?   ...   [1]  (ii)\t\twhat\tis\tthe\tpurpose\tof\tthe\tcatalyst?   ...   [1]  (b)\t\tthe\tgraph\tshows\tthe\tpercentage\tyield\tof\tammonia\t at\tdifferent\ttemperatures. 100 80 60 4020 0 100 0 200 300 temperature  / \u00b0cpercentage yield ofammonia 400 500 600  (i)\t\tdescribe\thow\tthe\tpercentage\tyield\tof\tammonia\tchanges\twith\ttemperature.   ...   [1]  (ii)\t\tdeduce\tthe \tpercentage\tyield\tof\tammonia\tat\t400\t \u00b0c.   ...   [1]",
            "14": "14 0620/31/o/n/17 \u00a9 ucles 2017  (c)\t\tcopper( ii)\toxide\treacts\twith\tammonia. copper( ii)\toxide\t\t+\t\tammonia\t\t \t\tcopper\t\t+\t\tnitrogen\t\t+\t\twater \t\twhen\t20\tg\tof\tcopper( ii)\toxide\treact\twith\tan\texcess\tof\tammonia,\t16\t g\tof\tcopper\tare\tformed. \t\tcalculate\t the\tmass\tof\tcopper\tformed\twhen\t140\tg\tof\tcopper( ii)\toxide\treact\twith\tan\texcess\tof\t ammonia. .. g  [1]  (d)\t\tammonia\tis\tused\tin\tthe\tmanufacture\tof\tnylon. \t\tgive\tone\tuse\tof\tnylon.   ..   [1] [total:\t6]",
            "15": "15 0620/31/o/n/17 \u00a9 ucles 2017blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.",
            "16": "16 0620/31/o/n/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w17_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32   paper 3 theory (core) october/november 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib17 11_0620_32/3rp\u00a9 ucles 2017 *9126653271* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/o/n/17 \u00a9 ucles 2017 1\t\tthe\tdiagram\tshows\tthe\tstructures\tof\tfive\tsubstances,\ta,\tb,\tc,\td\tand\te. ab dec ch c h sh hh hhhs ooss sss s sss sscl cl \t\tanswer\tthe\tfollowing\tquestions\tusing\tonly\tthe\tstructures\tin\tthe\tdiagram. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall.  (a)\t\twhich\tstructure,\ta,\tb,\tc,\td or e,  (i)\t\tis\tan\telement,\t ...   [1]  (ii)\t\thas\ta\tstructure\tsimilar\tto\tethanol,\t  .   [1]  (iii)\t\tis\ta\tcompound\twhich\tcontributes\tto\tacid \train,\t ..   [1]  (iv)\t\thas\tdouble \tcovalent\tbonds,\t  ..   [1]  (v)\t\tcontains\thalogen\tatoms?\t  ..   [1]  (b)  structure a\tis\ta\tnon-metal.   state three\ttypical\tdifferences\tbetween\tmetals\tand\tnon-metals.  1  .  2  .  3  ...   [3]  (c)  structure b\tis\thydrogen\tsulfide. \t\thydrogen\tsulfide\tis\ta\tcompound. \t\twhat\tis\tmeant\tby\tthe\tterm\tcompound \t?      ..   [1] [total:\t9]",
            "3": "3 0620/32/o/n/17 \u00a9 ucles 2017 [turn over 2\t\tthe\tdiagram\tshows\tthe\tcomposition\tof\tthe\tplanet\tsaturn. liquid hydrogen liquid heliumatmosphere rocky core75.0% hydrogen 24.9% helium 0.1% other gases  (a)\t\tdescribe\thow\tsaturn\u2019s\tatmosphere\tdiffers\tfrom\tthe\tearth\u2019s\tatmosphere. \t\tgive\tthree\tdifferences.  1  .     2  .     3  .    [3]  (b)\t\tsome\tproperties\tof\thydrogen\tand\thelium\tare\tgiven\t in\tthe\ttable. elementdensity\tof\tthe liquid\tin\tg\t/\tcm3melting\tpoint in\t\u00b0cboiling\tpoint in\t\u00b0c hydrogen 0.07 \u2013259 \u2013253 helium 0.15 \u2013272 \u2013269  (i)\t\tuse\tthe\tinformation\t to\tsuggest\twhy\tthe\tlayer\tof\tliquid\thydrogen\t in\tsaturn\tfloats\ton\ttop\tof\t the\tliquid\thelium.   ...   [1]  (ii)\t\twhat\tis\tthe\tphysical\tstate\tof\thydrogen\tat\t\u2013250\t \u00b0c? \t \texplain\tyour\tanswer.   .   ...   [2]",
            "4": "4 0620/32/o/n/17 \u00a9 ucles 2017  (c)\t\tthe\tatmosphere\tof\tsaturn\tcontains\tsmall\tamounts\t of\tammonia.  (i)\t\tdescribe\ta\t test\tfor\tammonia.  test  .. \t result\t ... [2]  (ii)\t\tammonia\tis \ta\tcovalent\tcompound. \t \tcomplete\tthe\tdiagram\tto\tshow \t \u25cf\t\tthe\tarrangement\tof\telectrons\tin\ta\tmolecule\tof\tammonia, \t \u25cf\t\tthe\tsymbols\tof\tthe\tatoms\tpresent. \t \tshow\touter\telectrons\tonly. [2]  (d)\t\tsaturn\u2019s\tatmosphere\talso\tcontains\tsmall\tamounts\tof\tammonium\thydrosulfide. \t\tcalculate\tthe\trelative\tmolecular\tmass\tof\tammonium\thydrosulfide,\tnh4sh. \t\tuse\tyour\tperiodic\t table\tto\thelp\tyou. relative\tmolecular\tmass\t=\t..\t\t[2]  (e)\t\tsaturn\u2019s\tatmosphere\talso\tcontains\tsmall\tamounts\tof\tmethane. \t\tsmall\tamounts\tof\tmethane\tare\tpresent\tin\tthe\tearth\u2019s\tatmosphere. \t\tmethane\tis\ta\tgreenhouse\tgas.  (i)\t\tname\tanother\tgreenhouse\tgas\tpresent\t in\tthe\tearth\u2019s\tatmosphere.   ...   [1]  (ii)\t\tscientists\t are\tconcerned\t about\tthe\tincrease\tin\tthe\tamount\tof\tgreenhouse\t gases\tin\tthe\t earth\u2019s\tatmosphere. \t \texplain\twhy.   ...   [1] [total:\t14]",
            "5": "5 0620/32/o/n/17 \u00a9 ucles 2017 [turn over 3\t\tthe\tfollowing\tcompounds\tare\tpresent\tin\ta\tliquid\t used\tfor\tcleaning\tmetal. ethanoic\tacid ethanol glycerol sodium\tchloride water  (a) (i)\t\tdraw\tthe\tstructure\tof\tthe\tfunctional\tgroup\tpresent\tin\tethanoic\tacid. [1]  (ii)  which one\tof\tthe\tfollowing\tph\tvalues\tis \tacidic? \t \tput\ta\tcircle\taround\tthe\tcorrect\tanswer. ph\t4\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t 7\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t 9\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t 13 [1]  (iii)\t\tethanoic\tacid\treacts\twith\tsodium\thydroxide. \t \twhat\ttype\tof\treaction\tis\tthis? \t \tput\ta\tcircle\taround\tthe\tcorrect\tanswer. neutralisation               oxidation               polymerisation               reduction [1]  (iv)\t\tthe\treaction\tof\tethanoic\tacid\twith\tsodium\thydroxide\tis\texothermic. \t \twhat\tis\tmeant\tby\tthe\tterm\texothermic ?   ...   [1]  (b)\t\tthe\tstructure\tof\tglycerol\tis\tshown. hchchc ooo hhhh h \t\tdeduce\tthe\tmolecular\t formula\tof\tglycerol\tshowing\tthe\tnumber\tof\tcarbon,\thydrogen\t and\toxygen\t atoms.   ..   [1]",
            "6": "6 0620/32/o/n/17 \u00a9 ucles 2017  (c)\t\tbalance\tthe\tchemical\tequation\tfor\tthe\tincomplete\tcombustion\tof\tethanol. c2h5oh  +  2o2    ..co  +  ..h2o [2]  (d) (i)\t\tdescribe\ta\tmethod\tof\tobtaining\t pure\tsamples\tof\tboth\tsodium\tchloride\tand\twater\tfrom\t aqueous\tsodium\tchloride.\texplain\twhy\tthis\tmethod\tworks.   .   .   .   .   ...   [3]  (ii)\t\twhich\tphysical\tproperty\tcould\tyou\tmeasure\tto\tfind\tout\tif\ta\tsample\tof\twater\tis\tpure?   ...   [1]  (iii)\t\tsodium\tchloride\tcontains\tchloride\tions. \t \tdescribe\ta\ttest\tfor\tchloride\tions.  test  .. \t result\t ... [2] [total:\t13]",
            "7": "7 0620/32/o/n/17 \u00a9 ucles 2017 [turn over 4\t\tthe\ttable\tshows\tthe\tproperties\tof\tfour\tsubstances. substance boiling\tpointelectrical conductivity of\tsolidelectrical\t conductivity when\tmoltensolubility in\twater calcium\tiodide very\thigh does\tnot\tconduct conducts phosphorus low does\tnot\tconduct does\tnot\tconduct insoluble sodium\tchloride very\thigh does\tnot\tconduct conducts soluble zinc high conducts insoluble  (a)\t\tcomplete\t the\ttable\tto\tshow\tthe\tsolubility\tin\twater\tof\tcalcium\tiodide\tand\tthe\telectrical\tconductivity \t of\tsolid\tzinc.\t [2]  (b)\t\tgive\t one\tpiece\tof\tevidence\tfrom\tthe\ttable\tthat\tshows\tthat\tphosphorus\t is\ta\tsimple\tcovalent\t substance.   ..   [1]  (c)\t\twhat\tinformation\tin\tthe\ttable\tshows\tthat\tsodium\tchloride\tis\tan\tionic\tcompound?      ..   [2]  (d)\t\tmolten\tcalcium\tiodide\tcan\tbe\telectrolysed. \t\tpredict\tthe\tproducts\tof\tthis\telectrolysis\tat \t the\tpositive\telectrode\t(anode),\t  .. \t the\tnegative\telectrode\t(cathode).\t  .. [2]  (e)\t\tan\tatom\tof\tphosphorus\thas\t31\tnucleons. \t\tdeduce\tthe\tnumber\tof\tprotons\tand\tneutrons\tpresent\tin\t one atom of phosphorus. \t\tuse\tyour\tperiodic\t table\tto\thelp\tyou. \t number\tof\tprotons\t  . \t number\tof\tneutrons\t  ... [2]",
            "8": "8 0620/32/o/n/17 \u00a9 ucles 2017  (f)\t\tphosphorus\tburns\tin\tan\texcess\tof\tair\tto\tform\tphosphorus( v)\toxide. \t\tis\tphosphorus( v)\toxide\tan\tacidic\toxide\tor\ta\tbasic\toxide? \t\texplain\tyour\tanswer.      ..   [1]  (g)\t\tarsenic\tis\tin\tthe\tsame\tgroup\tof\tthe\tperiodic\t table\tas\tphosphorus. \t\tarsenic\tsublimes\tat\t613\t \u00b0c. \t\twhat\tis\tmeant\tby\tthe\tterm\tsublimation ?      ..   [1] [total:\t11]",
            "9": "9 0620/32/o/n/17 \u00a9 ucles 2017 [turn over 5\t\tnickel\tcan\tbe\tobtained\tfrom\tnickel( ii)\toxide\tby\theating\tit\twith\ta\tmixture\tof\tcarbon\tmonoxide\t and\t hydrogen. 2nio\t\t+\t\tco\t\t+\t\th2  \t\t2ni\t\t+\t\tco2  +  h2o  (a)\t\thow\tdoes\tthis\tequation\tshow\tthat\tthe\tnickel( ii)\toxide\tis\treduced?   ..   [1]  (b)\t\tnickel\tcan\tbe\tpurified\tby\treacting\timpure\tnickel\twith \tcarbon\tmonoxide. \t\ta\tcompound\tcalled\ttetracarbonylnickel,\tni(co)4,\tis\tformed. ni\t\t+\t\t4co\t\t \t\tni(co)4 \t\twhat\tis\tthe\tmeaning\tof\tthe\tsymbol\t ?   ..   [1]  (c)\t\tthe\ttetracarbonylnickel\tis\theated\tto\tobtain\tpure\tnickel. ni(co)4  \t\tni\t\t+\t\t4co  (i)\t\tsuggest\twhy\tthe\tnickel\tobtained\tcan\tbe \tseparated\teasily\tfrom\tthe\tcarbon\tmonoxide.   ...   [1]  (ii)  state one\tadverse\teffect\tof\tcarbon\tmonoxide\ton\thealth.   ...   [1]  (d)\t\tnickel\tis\ta\ttransition\telement. \t\tpotassium\tis\ta\tgroup\ti\telement.  (i)\t\tdescribe\t two\tdifferences\tin\tthe\tphysical\tproperties\tof\tnickel\tand\tpotassium.  1  ..   .  2  ..   . [2]  (ii)\t\tdescribe\t one\tdifference\tin\tthe\tproperties\tof\tnickel( ii)\tchloride\tand\tpotassium\tchloride.   ...   [1]",
            "10": "10 0620/32/o/n/17 \u00a9 ucles 2017  (e)\t\tthe\tproperties\t and\trelative\treactivity\twith\twater\tof\tsome\tgroup\ti\telements\t are\tshown\tin\tthe\t table. element density\tin\tg\t /\tcm3boiling\tpoint\tin\t \u00b0crelative\treactivity\twith\twater sodium 883forms\tbubbles\trapidly but\tdoes\tnot\tburst\tinto\tflames potassium 0.86 760forms\tbubbles\tvery\trapidly and\tbursts\tinto\tflames rubidium 1.53 caesium 1.88 669 reacts\texplosively  (i)\t\tcomplete\tthe\ttable \t \u25cf\t\tto\tpredict\tthe\tboiling\tpoint\tof\trubidium, \t \u25cf\t\tfor\tthe\trelative\treactivity\tof\trubidium\twith\twater.  [2]  (ii)\t\tdescribe\tthe\tgeneral\ttrend\tin\tthe\tdensity \tof\tthe\tgroup\ti\telements.   ...   [1] [total:\t10]",
            "11": "11 0620/32/o/n/17 \u00a9 ucles 2017 [turn over 6\t\tethanol\tcan\tbe\tmanufactured\tfrom\tethene\tor\tby\t the\tfermentation\tof\tglucose.  (a)\t\tdescribe\tthese\t two\tmethods\tof\tmanufacturing\tethanol. \t\tin\tyour\tanswer,\tinclude \t \u25cf\t \tthe\tnames\tof\tany\tadditional\tsubstances \tneeded, \t \u25cf\t \tthe\treaction\tconditions.                        ..   [5]  (b)\t\tethene\tis\tan\tunsaturated\thydrocarbon.  (i)\t\tdescribe\thow\tyou\tcould\tdistinguish\t between\tan\tunsaturated\t hydrocarbon\t and\ta\tsaturated\t hydrocarbon\tusing\taqueous\tbromine.   .   .   ...   [2]  (ii)\t\tethene\tmolecules\tcan\tform\tpolymers. \t \twhich\tphrase\tdescribes\ta\tpolymer? \t \ttick\tone\tbox. \t \ta\tgiant\tstructure\tcontaining\tone\ttype\tof\tatom \t \ta\tlarge\tmolecule\tformed\tby\tcracking\tmonomers \t \ta\tlarge\tmolecule\tformed\tby\tthe\taddition\tof\tmany\tions \t \ta\tlarge\tmolecule\tformed\tfrom\tmany\tmonomers [1]  (iii)  terylene\tis\ta\tpolymer. \t \tgive\tone use of terylene .   ...   [1] [total:\t9]",
            "12": "12 0620/32/o/n/17 \u00a9 ucles 2017 7\t\tsulfur\tdichloride,\tsc l 2,\tis\ta\tred\tliquid\twhich\tvaporises\teasily\tat\troom\ttemperature\tand\tpressure.  (a)\t\ta\tdrop\tof\tsulfur\tdichloride\twas\tplaced\tin\tthe\tcorner\t of\ta\tglass\tbox. \t\tthe\tglass\tbox\twas\tclosed\tand\tleft\tfor\t12\thours. \t\tafter\t12\thours\ta\tred\tvapour\thad\tspread\tto\tfill\tthe\twhole\tbox. at the start after 1 hour after 12 hoursdrop of sulfur dichlorideglass box \t\texplain\tthese\tobservations\tusing\tthe\tkinetic\tparticle\tmodel.               ..   [3]  (b)\t\tsulfur\tdichloride\tcan\tbe\tmade\tby\tpassing\tchlorine\tthrough\tliquid\tdisulfur\tdichloride,\ts2cl 2. \t\tcomplete\tthe\tchemical\tequation\tfor\tthis\treaction. s2cl 2  +  ..    ..sc l 2 [2]  (c)\t\tsome\tchanges\tof\tstate\tof\tsulfur\tdichloride\tare\tshown. sc l 2 solidscl  2 liquidscl  2 gasmelting pevaporating q \t\tname\tthe\tchanges\tof\tstate\trepresented\tby\t p\tand\tq.  p    q   [2] [total:\t7]",
            "13": "13 0620/32/o/n/17 \u00a9 ucles 2017 [turn over 8\t\tcalcium\tcarbonate\t(limestone)\tdecomposes\twhen\theated. caco3    cao  +  co2  (a)\t\twhen\t20.0\tg\tof\tcalcium\tcarbonate\t are\tdecomposed,\t 11.2\tg\tof\tcalcium\toxide\t(lime),\tcao,\tare\t formed. \t\tcalculate\tthe\tmass\tof\tcalcium\toxide\tformed\twhen\t160.0\tg\tof\tcalcium\tcarbonate\t are\tdecomposed. .. g  [1]  (b)\t\tthe\tgraph\tshows\tthe\tvolume\tof\tcarbon\tdioxide\tproduced\t when\tsome\tsmall\tpieces\tof\t calcium\tcarbonate\tare\theated\tand\tdecompose. 300 200 100 0 10 02 03 0 time  / minutesvolume of carbon dioxide / cm3 40 50  (i)\t\tdeduce\tthe\tvolume\tof\tcarbon\tdioxide\tproduced\t during\tthe\tfirst\t20\tminutes\tof\tthe\t decomposition.   ...   [1]  (ii)\t\tat\twhat\ttime\twas\tthe\treaction\tcomplete?   ...   [1]  (iii)\t\twhat\twould\tbe\tthe\teffect,\tif\tany,\ton\tthe\trate\tof\treaction\tif\tthe\tsame\tmass\tof\tpowdered\t calcium\tcarbonate\twere\tused?   ...   [1]",
            "14": "14 0620/32/o/n/17 \u00a9 ucles 2017  (c)\t\tthe\ttable\tshows\thow\tlimestone\tis\tused. use\tof\tlimestonepercentage\tof\tlimestone used for this purpose agriculture cement\tmanufacture 37 chemical\tindustries 14 iron\tand\tsteel\tmanufacture 11 road\tbuilding 20 other uses 2 total 100  (i)\t\twhat\tpercentage\tof\tlimestone\tis\tused\tin \tagriculture?   ...   [1]  (ii)\t\tlimestone\t and\tlime\tare\tused\tin\tagriculture. \t \twhy\tis\tlime\tused\tin\tagriculture?   .   ...   [2] [total:\t7]",
            "15": "15 0620/32/o/n/17 \u00a9 ucles 2017blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.",
            "16": "16 0620/32/o/n/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w17_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33   paper 3 theory (core) october/november 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib17 11_0620_33/4rp\u00a9 ucles 2017 *5730339853* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/33/o/n/17 \u00a9 ucles 2017 1\t\tthe\tdiagram\tshows\tthe\tstructures\tof\tfive\tsubstances,\ta,\tb,\tc,\td\tand\te. ab de c nn os ooc ocl \u2013 cl \u2013nh4+ nh4+cl \u2013 cl \u2013nh4+ nh4+cl \u2013 cl \u2013nh4+ nh4+h hhn \t\tanswer\tthe\tfollowing\tquestions\tusing\tonly\tthe\tstructures\tin\tthe\tdiagram. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall.  (a)\t\twhich\tstructure,\ta,\tb,\tc,\td or e,  (i)\t\tis\ta\tcompound\twhich\tis\tused\tas\ta\tfertiliser,\t .   [1]  (ii)\t\tis\ta\tdiatomic\tmolecule,\t  .   [1]  (iii)\t\tcontains\tchloride\tions,\t  ..   [1]  (iv)\t\tis\ta\tgas\twhich\tturns\tdamp\tred\tlitmus\tpaper\tblue,\t    [1]  (v)\t is\tan\telement?\t ..   [1]  (b)  structure a\tis\tsulfur\tdioxide. \t\tsulfur\tdioxide\tis\tan\tatmospheric\tpollutant.  (i)  state one\tsource\tof\tsulfur\tdioxide.   ...   [1]  (ii)\t\tgive\tone\tadverse\teffect\tof\tsulfur\tdioxide \ton\thealth.   ...   [1]  (c)\t\tan\tisotope\tof\tnitrogen\tis\trepresented\tby\tthe\tsymbol\t15n7. \t\tdeduce\tthe\tnumber\tof\tprotons,\tneutrons\tand\telectrons\tin\tthis\tisotope\tof\tnitrogen. \t number\tof\tprotons\t  . \t number\tof\tneutrons\t  ... \t number\tof\telectrons\t  ... [3] [total:\t10]",
            "3": "3 0620/33/o/n/17 \u00a9 ucles 2017 [turn over 2\t\tthe\tatmosphere\t of\tthe\tplanet\tvenus\tcontains\t96.4%\tcarbon\tdioxide,\t3.5%\tnitrogen\tand\tsmall\t amounts\tof\tother\tgases.  (a)\t\tdescribe\thow\tvenus\u2019 \tatmosphere\tdiffers\tfrom\tthe\tearth\u2019s\tatmosphere. \t\tgive\tthree\tdifferences.  1  .     2  .     3  .    [3]  (b)\t\tdescribe\ta\ttest\tfor\tcarbon\tdioxide.  test  . \t result\t .. [2]  (c)\t\tvenus\u2019\tatmosphere\talso\tcontains\tsmall\tamounts\tof\t water\tand\targon.  (i)\t\twater\tis\ta\tcovalent\tcompound. \t \tcomplete\tthe\tdiagram\tto\tshow \t \u25cf\t\tthe\tarrangement\tof\telectrons\tin\ta\tmolecule\tof\twater, \t \u25cf\t\tthe\tsymbols\tof\tthe\tatoms\tpresent. \t \tshow\touter\tshell\telectrons\tonly. [2]  (ii)\t\tthe\tmelting \tpoint\tof\targon\tis\t\u2013189\t \u00b0c. \t \tthe\tboiling\tpoint\tof\targon\tis\t\u2013186\t \u00b0c. \t \twhat\tis\tthe\tphysical\tstate\tof\targon\tat\t\u2013200\t \u00b0c? \t \texplain\tyour\tanswer.   .   ...   [2]",
            "4": "4 0620/33/o/n/17 \u00a9 ucles 2017  (iii)\t\targon\tis\tunreactive. \t \texplain\twhy\targon\tis\tunreactive\tin\tterms \tof\tits\telectronic\tstructure.   .   ...   [1]  (d)\t\tclouds\tof\tsulfuric\tacid\tare\tpresent\tin\tvenus\u2019 \tatmosphere. \t\tsulfuric\tacid\treacts\twith\tmagnesium\tcarbonate. h2so4  +  mgco3    mgso4  +  co2  +  h2o  (i)\t\twrite\tthe\tword\tequation\tfor\tthis\treaction.   ...   [2]  (ii)\t\tcalculate\tthe\trelative\tmolecular\tmass\tof \tsulfuric\tacid,\th2so4. \t \tuse\tyour\tperiodic\t table\tto\thelp\tyou. relative\tmolecular\tmass\t=\t..\t\t[2]  (e)\t\tsulfur\tdioxide\tis\tfound\tin\tthe\tatmospheres\tof\tboth\tvenus\tand\tthe\tearth.  (i)  state one\tuse\tof\tsulfur\tdioxide.   ...   [1]  (ii)\t\tsulfur\tdioxide\tdissolves\tin\twater\tto\tform \tan\tacidic\tsolution.   which one\tof\tthe\tfollowing\tph\tvalues\tis \tacidic? \t \tput\ta\tcircle\taround\tthe\tcorrect\tanswer. ph\t2\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t 7\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t 9\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t 14 [1] [total:\t16]",
            "5": "5 0620/33/o/n/17 \u00a9 ucles 2017 [turn over 3\t\tthe\tlist\tshows\tsome\tof\tthe\tcompounds\tused\tto\tmanufacture\tink. calcium\tcarbonate ethanoic\tacid iron(ii)\tsulfate potassium\tdichromate( vi) sodium\tsulfate sulfuric\tacid  (a)\t\twhich\tcompound\tis\tpresent\tin\tlimestone?   ..   [1]  (b)\t\thydrated\tiron( ii)\tsulfate\tis\theated\tgently. feso4.7h2o    feso4  +  7h2o  (i)\t\tdescribe\t what\tyou\twould\tsee\twhen\ta\ttest-tube\t containing\t a\tsmall\tamount\tof\t hydrated\tiron( ii)\tsulfate\tis\theated\tgently.   ...   [1]  (ii)\t\tdescribe\ta\t test\tfor\taqueous\tiron( ii)\tions.  test  .. \t result\t ... [2]  (c)\t\tiron(ii)\tsulfate\tcan\tbe\tprepared\tby\treacting\tan\texcess\tof\tiron\twith\tdilute\tsulfuric\tacid.  (i)\t\tcomplete\tthe\tchemical\tequation\tfor\tthis \treaction. fe  +  h2so4    feso4  +   [1]  (ii)\t\tdescribe\thow\tyou\tcould\tremove\tthe\texcess\tiron\tfrom\tthe\tmixture\tformed.   ...   [1]",
            "6": "6 0620/33/o/n/17 \u00a9 ucles 2017  (d) (i)\t\tcomplete\tthe\tstructure\tof\tethanoic\tacid\t to\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds. cco [2]  (ii)\t\tgive\tone\tobservation\twhen\taqueous\tethanoic\tacid\treacts\twith \tmagnesium.   ...   [1]  (e)\t\tblack\tink\tcontains\ta\tmixture\tof\tdifferent\tcoloured\tdyes. \t\tdraw\ta\tlabelled\tdiagram\tof\tthe\tapparatus\t used\tto\tseparate\tthese\tdifferent\tcoloured\tdyes\tby\t chromatography. [3]  (f)\t\tblue\tink\twas\tplaced\tat\tthe\tbottom\tof\ta\tbeaker\tcontaining\twater. \t\tafter\t2\tdays,\ta\tblue\tcolour\thad\tspread\tthroughout\tthe\tbeaker. at the start after 6 hours after 2 dayswater ink \t\texplain\tthese\tobservations\tusing\tthe\tkinetic\tparticle\tmodel.               ..   [3] [total:\t15]",
            "7": "7 0620/33/o/n/17 \u00a9 ucles 2017 [turn over 4\t\tthe\ttable\tshows\tthe\tproperties\tof\tfour\tsubstances. substance boiling\tpointelectrical conductivity of\tsolidelectrical conductivity when\tmoltendensity in\tg\t/\tcm3 aluminium high conducts conducts 2.70 diamond 3.51 potassium\tbromide high does\tnot\tconduct conducts 2.75 sulfur low does\tnot\tconduct 2.07  (a)\t\tcomplete\tthe\ttable\tto\tshow\tthe\telectrical\tconductivity\tof\tsolid\tdiamond\tand\tmolten\tsulfur.\t [2]  (b)\t\tgive\t one\tpiece\tof\tevidence\tfrom\tthe\ttable\tthat\tshows\tthat\tsulfur\tis\ta\tsimple\tcovalent\tsubstance.   ..   [1]  (c)\t\twhat\tinformation\tin\tthe\ttable\tshows\tthat\tpotassium \tbromide\tis\tan\tionic\tcompound?      ..   [2]  (d) (i)  state one\tproperty\tof\taluminium\t given\tin\tthe\ttable\twhich\tmakes\tit\tsuitable\tfor\tmaking\t aircraft.   ...   [1]  (ii)\t\taluminium\t oxide\tis\tobtained\tfrom\tthe\tore\tbauxite. \t \twhat\tmethod\tis\tused\tto\textract\taluminium\tfrom\taluminium\toxide?   ...   [1]  (e)\t\tmolten\tpotassium\tbromide\tcan\tbe\telectrolysed. \t\tpredict\tthe\tproducts\tof\tthis\telectrolysis\tat \t the\tpositive\telectrode\t(anode),\t  .. \t the\tnegative\telectrode\t(cathode).\t  .. [2]",
            "8": "8 0620/33/o/n/17 \u00a9 ucles 2017  (f) (i)  which two\tstatements\tdescribe\tthe\tstructure\tand\tbonding\tin\tdiamond? \t \ttick\ttwo\tboxes. \t \tdiamond\thas\tionic\tbonds. \t \tdiamond\thas\ta\tgiant\tstructure. \t \tdiamond\tis\ta\tsimple\tmolecule. \t \tdiamond\thas\tcovalent\tbonds. [1]  (ii)\t\tgive\tone\tuse\tof\tdiamond.   ...   [1] [total:\t11]",
            "9": "9 0620/33/o/n/17 \u00a9 ucles 2017 [turn over 5\t\tlead\tis\textracted\tfrom\tan\tore\twhich\tcontains\tlead( ii)\tsulfide.  (a)\t\tthe\tore\tis\tfirst\theated\tin\tair. \t\tbalance\tthe\tchemical\tequation\tfor\tthis\treaction. 2pbs\t\t+\t\t..o2  \t\t2pbo\t\t+\t\t..so2 [2]  (b)\t\tthe\tlead( ii)\toxide\tproduced\tis\tthen\treduced\twith\tcarbon. pbo\t\t+\t\tc\t\t \t\tpb\t\t+\t\tco  (i)\t\thow\tdoes\tthis\tequation\tshow\tthat\tthe\tlead( ii)\toxide\tis\treduced?   ...   [1]  (ii)\t\tlead\tis\ta\tmetal\tin\tgroup\tiv. \t \tiron\tis\ta\ttransition\telement. \t \tgive\ttwo\tphysical\tproperties\tthat\tare\ttypical\tof\ttransition\telements.  1  ..  2  .. [2]  (c)\t\tstate\tthe\tconditions\tneeded\tfor\tiron\tto\trust.   ..   [2]  (d)\t iron\tfrom\tthe\tblast\tfurnace\tis\tconverted\tinto\tsteel\tusing\toxygen\tand\tbasic\toxides.  (i)\t\twhat\tis\tthe\tpurpose\tof\tthe\toxygen?   ...   [1]  (ii)  which one\tof\tthese\toxides\tis\ta\tbasic\toxide? \t \tput\ta\tcircle\taround\tthe\tcorrect\tanswer. carbon dioxide           nitrogen dioxide           potassium oxide          sulfur trioxide \t \texplain\tyour\tanswer.   . [2]",
            "10": "10 0620/33/o/n/17 \u00a9 ucles 2017  (e)\t\tsteel\tis\tan\talloy. \t\twhat\tis\tmeant\tby\tthe\tterm\talloy ?      ..   [2]  (f) (i)\t\tgive\tone\tcommon\tuse\tof\tmild\tsteel.   ...   [1]  (ii)\t\tgive\tone\tcommon\tuse\tof\tstainless\tsteel.   ...   [1] [total:\t14]",
            "11": "11 0620/33/o/n/17 \u00a9 ucles 2017 [turn over 6\t\tthe\tdiagram\tshows\ta\tfractionating\tcolumn\tused\t for\tthe\tfractional\tdistillation\tof\tpetroleum. kerosene fractionfgasoline fractionrefinery gas  (a)\t\ton\tthe\tdiagram,\twrite \t \u25cf\t \tthe\tletter\tx\tto\tshow\twhere\tthe\ttemperature\tin\tthe\tfractionating\tcolumn\tis\thighest, \t \u25cf\t \tthe\tletter\tb\tto\tshow\twhere\tbitumen\tis\tremoved\tfrom\tthe\tfractionating\tcolumn. [2]  (b)\t\tgive\tthe\tname\tof\tthe\tfraction\tlabelled\t f\tin\tthe\tdiagram.   ..   [1]  (c)\t\trefinery\tgas\tcontains\tmethane,\tethane\tand\tpropane.  (i)\t\tdraw\tthe\tstructure\tof\ta\tmolecule\tof\tethane\tshowing\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds. [1]  (ii)\t\tmethane\tcan\tbe\tconverted\tto\thydrogen\t by\treaction\twith\tsteam. \t \tbalance\tthe\tchemical\tequation\tfor\tthis\treaction. ch4  +  h2o    co  +  ..h2 [1]  (iii)\t\tthis\treaction\tis\tendothermic. \t \twhat\tis\tmeant\tby\tthe\tterm\tendothermic ?   ...   [1]",
            "12": "12 0620/33/o/n/17 \u00a9 ucles 2017  (d)\t\tsome\tpetroleum\tfractions\tare\tcracked\tto\tform\tdifferent\thydrocarbons. \t\tdescribe\tthe\tprocess\tof\tcracking. \t\tin\tyour\tanswer \t \u25cf\t \texplain\twhat\tis\tmeant\tby\tthe\tterm\t cracking, \t \u25cf\t \tstate\tthe\tconditions\tneeded\tto\tcrack\thydrocarbons.                     .. \t\t[4]  (e)\t\tthe\ttable\tshows\tsome\tproperties\tof\tfour\talkanes. alkanenumber\tof carbon\tatoms\tin\t one\tmoleculeboiling\tpoint /\t\u00b0c methane 1 \u2013164 ethane 2 \u201388 propane 3 butane 4 0  (i)\t\thow\tdoes\tthe\tboiling\tpoint\tchange\tas\tthe\tnumber\tof\tcarbon\tatoms\tin\tone\tmolecule\t increases?   ...   [1]  (ii)\t\tpredict\tthe\tboiling\tpoint\tof\tpropane.   ...   [1]  (iii)\t\tdescribe\tthe\tarrangement\tand\tseparation\tof\tthe\tmolecules\tin\tliquid\tbutane. \t arrangement\t  ... \t separation\t  ... [2] [total:\t14]",
            "13": "13 0620/33/o/n/17 \u00a9 ucles 2017blank page",
            "14": "14 0620/33/o/n/17 \u00a9 ucles 2017blank page",
            "15": "15 0620/33/o/n/17 \u00a9 ucles 2017blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.",
            "16": "16 0620/33/o/n/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w17_qp_41.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/41   paper 4 theory (extended) october/november 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib17 11_0620_41/4rp\u00a9 ucles 2017 *1311966589* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/41/o/n/17 \u00a9 ucles 2017 1\t\tthe\ttable\tgives\tinformation\tabout\tfive\tparticles.\t the\tparticles\tare\tall\tatoms\tor\tions. particlenumber of protonsnumber of neutronsnumber of electrons a 6 8 6 b 12 12 12 c 13 14 10 d 8 8 10 e 11 12 11 \t\tanswer\tthe\tfollowing\tquestions\tusing\tthe\tinformation\tin\tthe\ttable. \t\teach\tparticle\tmay\tbe\tused\tonce,\tmore\tthan\tonce \tor\tnot\tat\tall.  (a)\t\twhich\tparticle,\ta,\tb,\tc,\td or e,  (i)\t\tis\tan\tatom\twith\tatomic\tnumber\t12,  \t ...   [1]  (ii)\t\tis\tan\tatom\twith\tnucleon\tnumber\t14,  \t ...   [1]  (iii)\t\tis\tan\tion\twith\ta\tpositive\tcharge,  \t ...   [1]  (iv)\t\thas\tonly\tone\telectron\tin\tits\touter\tshell?  \t ...   [1]  (b)  d\tis\tan\tion\tof\tan\telement. \t\tidentify\tthe\telement\tand\twrite\tthe\tformula\tof\t d.  \t..   [2] [total: 6]",
            "3": "3 0620/41/o/n/17 \u00a9 ucles 2017 [turn over 2\t\tthe\tgraph\tshows\thow\tthe\ttemperature\t of\ta\tsubstance\t changes\tas\tit\tis\tcooled\tover\ta\tperiod\tof\t 30\tminutes.\t the\tsubstance\tis\ta\tgas\tat\tthe\tstart. 0 10 20 30300 250 200 150 100 50 0temperature / \u00b0c time  / minutess t w x y zv \t\teach\tletter\ton\tthe\tgraph\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall.  (a)\t\twhich\tletter,\ts,\tt,\tv,\tw,\tx,\ty or z,\tshows\twhen  (i)\t the\tparticles\tin\tthe\tsubstance\thave\tthe\tmost\tkinetic\tenergy,  \t ...   [1]  (ii)\t\tthe\tparticles\tin\tthe\tsubstance\tare\tfurthest\tapart,  \t ...   [1]  (iii)\t\tthe\tsubstance\texists\tas\tboth\ta\tgas\tand\ta\tliquid?  \t ...   [1]  (b)\t\tuse\tthe\tgraph\tto\testimate\tthe\tfreezing\tpoint\tof\tthe\tsubstance. \t ..\t \u00b0c  [1]  (c)\t\tname\tthe\tchange\tof\tstate\tdirectly\tfrom\ta\tsolid\tto\ta\t gas.  \t..   [1]  (d)\t\twhen\tsmoke\tis\tviewed\tthrough\ta\tmicroscope,\t the\tsmoke\tparticles\tin\tthe\tair\tappear\tto\tjump\t around.  (i)\t\twhat\tterm\tdescribes\tthis\tmovement\tof\tthe\tsmoke\tparticles?  \t ...   [1]  (ii)\t\texplain\twhy\tthe\tsmoke\tparticles\tmove\tin \tthis\tway.  \t .  \t .  \t ...   [2] [total: 8]",
            "4": "4 0620/41/o/n/17 \u00a9 ucles 2017 3 (a)\t\twhen\tmagnesium\tis\tadded\tto\taqueous\tcopper( ii)\tsulfate\ta\treaction\toccurs. \t\tthe\tionic\tequation\tfor\tthe\treaction\tis\tshown. mg  +  cu2+    mg2+  +  cu  (i)  give one\tchange\tyou\twould\tobserve\tduring\tthis\treaction.  \t ...   [1]  (ii)\t\texplain\twhy\tthis\tis\ta\tredox\treaction.  \t .  \t ...   [1]  (iii)\t\tidentify\tthe\toxidising\tagent\tin\tthis\treaction.\tgive\ta\treason\tfor\tyour\tanswer.  \t .  \t ...   [2]  (iv)\t\ta\tredox\treaction\toccurs\twhen\tmagnesium\tis\theated\twith\tiron( iii)\toxide. \t \twrite\ta\tchemical\tequation\tfor\tthe\treaction\tbetween\tmagnesium\tand\tiron( iii)\toxide.  \t ...   [2]  (b)\t\tthe\tmetal\tiron\tand\tthe\talloy\tsteel\tare\tcommonly\t used\tmaterials.\t a\tproblem\twith\tthem\tis\tthat\t they\trust.  (i)\t\thow\tdoes\tpainting\tiron\tand\tsteel\tprevent\trusting?  \t .  \t ...   [1]  (ii)\t\tmagnesium \tblocks\tcan\tbe\tattached\tto\tthe\tbottom\tof\tsteel\tboats. \t \texplain\thow\tthe\tmagnesium\t blocks\tprevent\tthe\twhole\tof\tthe\tbottom\tof\tthe\tboat\tfrom\t rusting.  \t .  \t .  \t .  \t ...   [2]",
            "5": "5 0620/41/o/n/17 \u00a9 ucles 2017 [turn over  (iii)\t\treplacing\tthe\tmagnesium\tblocks\twith\tcopper\tblocks\tdoes\tnot\tprevent\trusting. \t \texplain\twhy\tthe\tcopper\tblocks\tdo\t not\tprevent\trusting.  \t .  \t ...   [1] [total: 10]",
            "6": "6 0620/41/o/n/17 \u00a9 ucles 2017 4 (a)\t\tethanol,\tc2h5oh,\tcan\tbe\tmade\tby\tfermentation.  (i)\t\tcomplete\tthe\tchemical\tequation\tfor\tthe\t formation\tof\tethanol\tby\tfermentation. c6h12o6  \t\t..c2h5oh\t\t+\t\t.. [2]  (ii)  state two\tconditions\trequired\tfor\tfermentation.  1 \t ..  2 \t .. [2]  (b)\t\tethanol\tcan\talso\tbe\tmade\tby\tthe\tcatalytic\thydration\tof\tethene.\tthe\tequation\tfor\tthe\treaction\tis\t shown. c2h4  +  h2o    c2h5oh  (i)\t\tname\ta\tsuitable\tcatalyst\tfor\tthis\treaction.  \t ...   [1]  (ii)\t\tcalculate\tthe\tmaximum\tmass\tof\tethanol\tthat\tcan\tbe\tmade\tfrom\t56\t g\tof\tethene. maximum\tmass\tof\tethanol\t=\t.\tg\t\t[2]  (c)\t\tethanol\tcan\tbe\toxidised\tto\tform\tethanoic\tacid.  (i)\t\tname\ta\tsuitable\toxidising\tagent\tfor\tthis\t reaction.  \t ...   [1]",
            "7": "7 0620/41/o/n/17 \u00a9 ucles 2017 [turn over  (ii)\t\ta\tmolecule\tof\tethanoic\tacid\thas\tthe\tstructure\tshown. cco ohh h h \t \tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\tethanoic\tacid.\t show\touter\tshell\telectrons\tonly. hc h co o hh [3]  (d)\t\tethanoic\tacid\tis\ta\tweak\tacid.  (i)\t\twhen\treferring\tto\tan\tacid,\twhat\tis\tmeant\tby\tthe\tterm\t weak?  \t .  \t ...   [1]  (ii)\t\tdescribe\thow\tyou\tcould\tshow\tthat\tethanoic\tacid\tis\ta\tweaker\tacid\tthan\thydrochloric\tacid.  \t .  \t .  \t .  \t ...   [3]",
            "8": "8 0620/41/o/n/17 \u00a9 ucles 2017  (e)\t\tcarboxylic\tacids\treact\twith\talcohols\tto\tmake\testers. \t\tthe\tstructure\tof\tan\tester\tis\tshown. cco och hhh h cc ch h hhh hh c hh \t\tdraw\tthe\tstructures\tof\tthe\tcarboxylic\tacid\tand\talcohol\tfrom\twhich\tthis\tester\tcan\tbe\tmade. \t\tgive\tthe\tnames\tof\tthe\tcarboxylic\tacid\tand\talcohol. \t structure\tof\tthe\tcarboxylic\tacid \t name\tof\tthe\tcarboxylic\tacid\t \t... \t structure\tof\tthe\talcohol \t name\tof\tthe\talcohol\t \t... [4] [total: 19]",
            "9": "9 0620/41/o/n/17 \u00a9 ucles 2017 [turn over 5 (a)\t\tsolid\tcopper( ii)\tcarbonate\t undergoes\t thermal\tdecomposition.\t one\tof\tthe\tproducts\tof\tthe\t thermal\tdecomposition\tis\tcopper( ii)\toxide.  (i)\t\tstate\tthe\tcolour\tchange\tof\tthe\tsolid\tseen\tduring\tthe\treaction. \t start\tcolour\t\t  .. \t end\tcolour\t \t ... [1]  (ii)\t\twrite\ta\tchemical\tequation\tfor\tthe\tthermal\tdecomposition\tof\tcopper( ii)\tcarbonate.  \t ...   [1]  (b)\t\tcopper( ii)\tcarbonate\t reacts\twith\tdilute\tnitric\tacid.\tone\tof\tthe\tproducts\tof\tthe\treaction\tis\ta\t solution\tof\tcopper( ii)\tnitrate.  (i)\t\tdescribe\ttests\tfor\tcopper( ii)\tions\tand\tnitrate\tions.\tinclude\tthe\tresults\tof\tthe\ttests. \t copper( ii) ions \t   \t .  \t .  nitrate ions \t ...  \t .  \t . [4]  (ii)\t\tcopper( ii)\tnitrate\tundergoes\tthermal\tdecomposition. \t \tbalance\tthe\tchemical\tequation\tfor\tthe\tthermal\tdecomposition\tof\tcopper( ii)\tnitrate. ..cu(no3)2  \t\t..cuo\t\t+\t\t..no2\t\t+\t\t..o2 [1]",
            "10": "10 0620/41/o/n/17 \u00a9 ucles 2017  (c)\t\tnitrogen\tdioxide,\tno2,\texists\tin\tequilibrium\twith\tdinitrogen\ttetroxide,\tn2o4. \t\tnitrogen\tdioxide\tis\tbrown\tand\tdinitrogen\ttetroxide\tis\tcolourless. 2no2(g)\t\t   n2o4(g)  brown\t colourless  (i)\t\ta\tsample\tof\tnitrogen\tdioxide\tand\tdinitrogen\t tetroxide\tat\tequilibrium\t was\tplaced\tin\ta\tclosed\t gas\tsyringe. \t \tthe\tsyringe\tplunger\twas\tpushed\tin.\tthis\tincreased\t the\tpressure\tin\tthe\tgas\tsyringe.\tthe\t temperature\twas\tkept\tconstant. nitrogen dioxide and dinitrogen tetroxide at equilibrium end blocked gas syringe \t \tstate\thow\tthe\tcolour\tof\tthe\tgas\tin\tthe\tsyringe\tchanged.\t explain\tyour\tanswer\tin\tterms\tof\t the\tposition\tof\tthe\tequilibrium.  \t .  \t .  \t .  \t ...   [3]  (ii)\t\ta\tsealed\ttube\tcontaining\t nitrogen\tdioxide\tand\tdinitrogen\t tetroxide\tat\tequilibrium\t was\t cooled\tin\tan\tice\tbath\tat\tconstant\tpressure.\t the\tcontents\tof\tthe\ttube\tbecame\tpaler. \t \tsuggest\tan\texplanation\tfor\tthis\tobservation\tin\tterms\tof\tthe\tposition\tof\tthe\tequilibrium.  \t .  \t .  \t ...   [2] [total: 12]",
            "11": "11 0620/41/o/n/17 \u00a9 ucles 2017 [turn over 6\t\taluminium\tis\textracted\tfrom\taluminium\toxide\tby\t electrolysis.  (a)\t\twhy\tis\taluminium\t not\textracted\tby\theating\taluminium\toxide\twith\tcarbon?  \t  \t..   [1]  (b)\t\taluminium\toxide\tis\tan\tionic\tcompound\twith\ta\thigh\tmelting\tpoint.  (i)\t\tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\tone of the  oxide\tions\tpresent\tin\taluminium\toxide.\tinclude\tthe\tcharge\ton\tthe\toxide\tion. \t \tone\tof\tthe\taluminium\tions\tis\tshown. al o3+ [2]  (ii)\t\tthe\tmelting \tpoint\tof\taluminium\toxide\tis\t above\t2000\t \u00b0c. \t \texplain\twhy\taluminium\toxide\thas\ta\thigh \tmelting\tpoint.  \t .  \t .  \t ...   [2]",
            "12": "12 0620/41/o/n/17 \u00a9 ucles 2017  (c)\t\taluminium\tcan\tbe\textracted\tby\telectrolysis\tusing\tthe\tapparatus\tshown. molten aluminiumaluminium oxide and cryolite cathodewires anodes ++power supply\u2013 +  (i)\t\tname\tthe\ttype\tof\tparticle\tresponsible\tfor\tthe\ttransfer\tof\tcharge\tin \t the\twires,\t\t   \t the\telectrolyte.\t\t   [2]  (ii)  give two\treasons\twhy\tcryolite\tis\tused.  1 \t ..  2 \t .. [2]  (iii)\t\twrite\tthe\tionic\thalf-equation\tfor\tthe\tformation\tof\taluminium\tduring\tthe\telectrolysis.  \t ...   [1]  (iv)\t\texplain\thow \tcarbon\tdioxide\tgas\tis\tformed\tat\tthe\tanodes.  \t .  \t .  \t ...   [3]  (d)\t\twhen\ta\tpiece\tof\taluminium\t is\tplaced\tin\tdilute\thydrochloric\t acid,\tthere\tis\tno\timmediate\t visible\t reaction.   if the aluminium is left in the dilute\thydrochloric\t acid\tfor\tseveral\thours,\tbubbles\tstart\tto\tform. \t\texplain\twhy\taluminium\tdoes\t not\treact\timmediately\twith\tdilute\thydrochloric\tacid.  \t  \t..   [1] [total: 14]",
            "13": "13 0620/41/o/n/17 \u00a9 ucles 2017 [turn over question 7 starts on the next page.",
            "14": "14 0620/41/o/n/17 \u00a9 ucles 2017 7\t\tcopper( ii)\toxide\treacts\twith\tdilute\thydrochloric\tacid. cuo(s)\t\t+\t\t2hcl\t (aq)\t\t   cucl 2(aq)\t\t+\t\th2o(l) \t\t6.00\tg\tof\tcopper( ii)\toxide\twere\tadded\tto\t50.0\tcm3\tof\t1.00\tmol\t/\tdm3\thydrochloric\t acid.\tthis\twas\tan\t excess\tof\tcopper( ii)\toxide.  (a)\t\tthe\trate\tof\tthe\treaction\tcan\tbe\tincreased\t by\tincreasing\t the\tconcentration\t of\tthe\thydrochloric\t acid\t or\tby\theating\tit.  (i)\t\tin\tterms\tof\tcollisions,\t explain\twhy\tincreasing\t the\tconcentration\t of\tthe\thydrochloric\t acid\t increases\tthe\trate\tof\tthe\treaction.  \t .  \t .  \t .  \t ...   [2]  (ii)\t\tin\tterms\tof\tcollisions,\t explain\twhy\theating\tthe\thydrochloric\t acid\tincreases\t the\trate\tof\tthe\t reaction.  \t .  \t .  \t .  \t ...   [2]",
            "15": "15 0620/41/o/n/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (b) (i)\t\tcalculate\tthe\tnumber\tof\tmoles\tof\tcopper( ii)\toxide\tadded\tto\tthe\thydrochloric\tacid. moles\tof\tcopper( ii)\toxide\t=\t.\tmol\t\t[2]  (ii)\t\tcalculate\tthe\tnumber\tof\tmoles\tof\thydrochloric\tacid\tused. moles\tof\thydrochloric\tacid\t=\t.\tmol\t\t[1]  (iii)\t\tcalculate\tthe\tmass\tof\tcopper( ii)\toxide\tthat\tdid\tnot\treact. mass\tof\tcopper( ii)\toxide\tthat\tdid\tnot\treact\t=\t.\tg\t\t[2]  (c)\t\tcrystals\tof\thydrated\tcopper( ii)\tchloride\twere\tobtained\tfrom\tthe\tsolution\tat\tthe\tend\tof\tthe\t reaction. \t\tthe\tcrystals\thad\tthe\tfollowing\tcomposition\t by\tmass:\tcl,\t41.52%;\t\t cu,\t37.43%;\t\t h,\t2.34%;\t\t o,\t18.71%. \t\tcalculate\tthe\tempirical\tformula\tof\tthe\tcrystals. empirical\tformula\t=\t.\t\t[2] [total: 11]",
            "16": "16 0620/41/o/n/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w17_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/42   paper 4 theory (extended) october/november 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib17 11_0620_42/4rp\u00a9 ucles 2017 *9307337210* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/o/n/17 \u00a9 ucles 2017 1 (a)  dust particles in the air move around in a random way.  (i)  what term describes the random movement of the dust particles?   ...   [1]  (ii)  identify the particles in the air which cause the random movement of the dust particles.   ...   [2]  (iii)  explain why the dust particles move in this way.   .   .   ...   [2]  (b)  when chlorine gas, c l 2, is put into a gas jar, it spreads out to fill the gas jar.   when bromine gas, br2, is put into a gas jar, it also spreads out to fill the gas jar.   the process takes longer for bromine gas than for chlorine gas. start latergasgas jar  (i)  what term describes the way that the gas particles spread out?   ...   [1]  (ii)  use data from the periodic table to explain why bromine gas takes longer to fill a gas jar  than chlorine gas.   .   .   ...   [2]  (iii)  explain why increasing the temperature increases the rate at which the gas particles  spread out.   .   ...   [1] [total: 9]",
            "3": "3 0620/42/o/n/17 \u00a9 ucles 2017 [turn over 2 (a)  complete the table to show the electronic structure of the atoms and ions. electronic structure f 2,7 si ca2+ n3\u2013 [3]  (b)  predict the formula of the compound formed between ca2+ and n3\u2013.   ..   [1]  (c)  draw a dot-and-cross diagram to show the electron arrangements in the two ions present in  lithium chloride, lic l.   show outer shell electrons only. include the charges on the ions. [3]  (d)  sulfur dichloride, sc l 2, is a covalent compound. it has the structure cl \u2013s\u2013cl.   draw a dot-and-cross diagram to show the electron arrangement in a molecule of  sulfur dichloride.   show outer shell electrons only. [3]",
            "4": "4 0620/42/o/n/17 \u00a9 ucles 2017  (e)  in terms of attractive forces, explain why lic l has a higher melting point than sc l 2.               ..   [3]  (f)  suggest the identity of a covalent compound  with a higher melting point than lic l.   ..   [1] [total: 14]",
            "5": "5 0620/42/o/n/17 \u00a9 ucles 2017 [turn over 3  the chemical equation for the complete combustion of ethanol, c2h5oh, is shown. c2h5oh  +  3o2    2co2  +  3h2o   the energy released when one mole of ethanol undergoes complete combustion is 1280 kj.   part of the energy level diagram for this reaction is shown. energyc2h5oh + 3o2x  (a)  complete the energy level diagram to show  \u25cf  the products of the reaction,  \u25cf  the overall energy change of the reaction.  [3]  (b)  what does x represent?   ..   [1]",
            "6": "6 0620/42/o/n/17 \u00a9 ucles 2017  (c)  the chemical equation for the complete combustion of methanol, ch3oh, is shown. 2ch3oh  +  3o2    2co2  +  4h2o   the equation can be represented as shown. h ch2o 3 o oh4 h h+ + o o2c o h   use the bond energies in the table to determine the energy change, \u03b4h, for the complete  combustion of one mole of methanol. bondbond energy in kj / mol c\u2013h 410 c\u2013o 360 o\u2013h 460 o=o 500 c=o 805  \u25cf  energy needed to break bonds .. kj  \u25cf  energy released when bonds are formed .. kj  \u25cf  energy change, \u03b4h, for the complete combustion of one mole of methanol .. kj / mol [4]",
            "7": "7 0620/42/o/n/17 \u00a9 ucles 2017 [turn over  (d)  dodecane is an alkane containing 12 carbon atoms. ethanol can be manufactured from  dodecane in a two-stage process.   in stage 1, each molecule of dodecane is converted into three molecules of ethene and one  molecule of another hydrocarbon.  (i)  name the process which occurs in stage 1.   ...   [1]  (ii)  write a chemical equation for the reaction which occurs in stage 1.   ...   [2]   in stage 2, ethene reacts with steam to produce ethanol.  (iii)  state two conditions needed for stage 2.  1  ..  2  .. [2]  (iv)  name the type of reaction which occurs in stage 2.   ...   [1]  (v)  suggest how to test the purity of the ethanol produced.   .   ...   [2]",
            "8": "8 0620/42/o/n/17 \u00a9 ucles 2017  (e)  ethanol can also be manufactured by the fermentation of glucose, c6h12o6.  (i)  state two conditions needed for the fermentation of glucose.  1  ..  2  .. [2]  (ii)  complete the chemical equation for the fermentation of glucose. c6h12o6    ..c2h5oh  +  .. [2]  (iii)  one disadvantage of fermentation is that the maximum concentration of ethanol produced  is about 15%.   suggest why the concentration of ethanol produced by fermentation does not exceed  15%.   .   ...   [1]  (iv)  give one other disadvantage of manufacturing ethanol by fermentation.   ...   [1]  (v)  give one advantage, other than cost, of manufacturing ethanol by fermentation.   ...   [1]  (vi)  suggest the name of a process to obtain ethanol from a mixture of ethanol and water.   ...   [1]",
            "9": "9 0620/42/o/n/17 \u00a9 ucles 2017 [turn over  (f)  ethane-1,2-diol has the following structure. h co hh c hh ho  (i)  write the empirical formula of ethane-1,2-diol.   ...   [1]  (ii)  ethane-1,2-diol can undergo condensation polymerisation but cannot undergo addition  polymerisation.   explain why ethane-1,2-diol cannot undergo addition polymerisation.   .   ...   [1]  (iii)  ethane-1,2-diol undergoes condensation polymerisation with molecule y.   the diagrams represent the structures of ethane-1,2-diol and molecule y. co h h o o ethane-1,2-diolco h h o o molecule y   draw the condensation polymer formed between ethane-1,2-diol and molecule y.   show one repeat unit. show all of the atoms and all of the bonds in the linkage. [3]  (iv)  name the type of condensation polymer formed between ethane-1,2-diol and molecule y.   ...   [1] [total: 30]",
            "10": "10 0620/42/o/n/17 \u00a9 ucles 2017 4  a student sets up the following electrolysis experiment. graphite electrodes dilute aqueous sodium chloridewirebulb +\u2013  (a)  define the term electrolysis .      ..   [2]  (b)  the student observes bubbles of colourless gas forming at each electrode.  (i)  name the main gas produced at the positive electrode (anode).   ...   [1]  (ii)  describe a test for the gas produced in (b)(i).  test  ..  result  ... [2]  (iii)  write the ionic half-equation for the reaction taking place at the negative electrode (cathode).   ...   [2]  (c)  charge is transferred during electrolysis.   name the type of particle responsible for the transfer of charge in  the wires,  ...  the electrolyte.  ... [2]",
            "11": "11 0620/42/o/n/17 \u00a9 ucles 2017 [turn over  (d)  the student replaces the dilute aqueous sodium chloride with concentrated aqueous  sodium chloride.   suggest two differences that the student observes.  1  .  2  . [2]  (e)  the student has a small piece of impure copper. the main impurities in the copper are small quantities of silver and zinc.   the student uses electrolysis to extract pure copper from the small piece of impure copper.  (i)  complete the labels on the diagram of the student\u2019s electrolysis experiment. +\u2013 . . ...anode made of cathode made of electrolyte of [3]  (ii)  use your knowledge of the reactivity series to suggest what happens to the silver and zinc  impurities. explain your answers.  silver impurities  ...   .   .  zinc impurities  .   .   . [3] [total: 17]",
            "12": "12 0620/42/o/n/17 \u00a9 ucles 2017 5  some chemical reactions are reversible.  (a)  aqueous potassium chromate( vi), k2cro4, is a yellow solution.   aqueous potassium dichromate( vi), k2cr2o7, is an orange solution.   the two compounds interconvert when the ph of the solution changes. 2k2cro4  +  h2so4    k2cr2o7  +  k2so4 +  h2o  yellow orange   solution y is a mixture of aqueous potassium chromate( vi) and aqueous   potassium dichromate( vi) at equilibrium.  \u25cf  explain, in terms of the position of the equilibrium, what you would see if sulfuric acid were  added to solution y.   .   .   .  \u25cf  explain, in terms of the position of the equilibrium, what you would see if sodium hydroxide  were added to solution y.   .   .   .   . [5]",
            "13": "13 0620/42/o/n/17 \u00a9 ucles 2017 [turn over  (b)  hydrogen can be manufactured using a reversible reaction between methane and steam. ch4(g)  +  h2o(g)    co(g)  +  3h2(g)   at 900 \u00b0c, in the presence of a nickel catalyst, the yield of hydrogen is 70%.  (i)  what volume of hydrogen is produced from 100 cm3 of methane under these conditions? .. cm3  [2]   under different conditions, different yields of hydrogen are obtained.  (ii)  if the pressure is increased, the yield of hydrogen becomes less than 70%.   explain why, in terms of the position of the equilibrium.   .   ...   [1]  (iii)  if the temperature is decreased, the yield of hydrogen decreases.   what does this information indicate about the reaction between methane and steam?   ...   [1]  (iv)  why is a catalyst used in this reaction?   ...   [1] [total: 10]",
            "14": "14 0620/42/o/n/17 \u00a9 ucles 2017blank page",
            "15": "15 0620/42/o/n/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "16": "16 0620/42/o/n/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w17_qp_43.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/43   paper 4 theory (extended) october/november 2017  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 12 printed pages. [turn overib17 11_0620_43/5rp\u00a9 ucles 2017 *6479123383* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/43/o/n/17 \u00a9 ucles 2017 1\t\tsubstances\tcan\tbe\tclassified\tas\telements,\tcompounds\tor\tmixtures. \t\tstate\twhether\teach\tof\tthe\tfollowing\tis\tan\telement,\ta\tcompound\tor\ta\tmixture.  (a)\t\tbrass\t\t   [1]  (b)\t\tgold\t\t..   [1]  (c)  butane \t..   [1]  (d)\t\tair\t\t.   [1] [total:\t4]",
            "3": "3 0620/43/o/n/17 \u00a9 ucles 2017 [turn over 2 (a) (i)\t\tdefine\tthe\tterm\tmolecule .  \t .  \t ...   [2]  (ii)\t\tdefine\tthe\tterm\telement .  \t .  \t ...   [1]  (b)\t\tthe\ttable\tshows\tthe\tcomposition\tof\tfour\tatoms\tor\tions,\ta,\tb,\tc\tand\td. number\tof protonsnumber\tof neutronsnumber\tof electrons a 10 10 10 b 10 12 10 c 12 10 10 d 13 14 10  (i)\t\twhat\tis\tthe\tatomic\tnumber\tof\ta?  \t ...   [1]  (ii)\t\twhat\tis\tthe\tnucleon\tnumber\tof\t b?  \t ...   [1]  (iii)\t\twhich\tof\ta,\tb,\tc\tand\td\tare\tisotopes\tof\teach\tother?  \t ...   [1]  (iv)\t\twhich\tof\ta,\tb,\tc\tand\td\tare\tatoms?  \t ...   [1]  (v)\t\twhich\tof\ta,\tb,\tc\tand\td\tare\tpositive\tions?  \t ...   [1]  (c)  complete\tthe\ttable. number\tof protonsnumber\tof electrons na s2\u2013 cl 2 [3] [total:\t11]",
            "4": "4 0620/43/o/n/17 \u00a9 ucles 2017 3\t\tiron\tis\textracted\tfrom\tits\tore\tusing\tcoke\tin\ta\tblast\tfurnace. slag molten ironair airwaste gases raw materials : coke, iron ore, limeston e  (a)\t\tname\tthe\tore\tof\tiron\twhich\tis\tmainly\tiron( iii)\toxide.  \t..   [1]  (b)\t\tdescribe\tthe\treactions\toccurring\tin\tthe\tblast\tfurnace. \t\tin\tyour\tanswer,\tinclude \t \u25cf\t \ttwo\treasons\tfor\tusing\tcoke\tin\tthe\tblast\tfurnace, \t \u25cf\t a\tchemical\tequation\tfor\tthe\treduction\tof \tiron( iii)\toxide, \t \u25cf\t an\texplanation\tfor\tusing\tlimestone\tin\tthe \tblast\tfurnace.  \t  \t  \t  \t  \t  \t  \t  \t  \t  \t  \t  \t..   [6]",
            "5": "5 0620/43/o/n/17 \u00a9 ucles 2017 [turn over  (c) (i)\t\tdescribe\tthe\tbonding\tin\tiron.\tinclude\ta\tdiagram\tin\tyour\tanswer.  \t .  \t ...   [3]  (ii)\t\tuse\tyour\tdiagram\tin\t (c)(i)\tto\texplain\twhy\tiron\tis\tmalleable.  \t .  \t ...   [2]  (iii)\t\tiron\tcontaining\ta\tsmall\tamount\tof\tcarbon\tis\tknown\tas\tsteel. \t \texplain\twhy\tsteel\tis\tless\tmalleable\tthan \tiron.  \t .  \t ...   [2]  (d) (i)\t\twhen\tiron\tis\tadded\tto\tdilute\tsulfuric\tacid,\tan\taqueous\tsolution\tof\tiron(ii)\tsulfate\tis\tformed\t as\tone\tof\tthe\tproducts. \t \twrite\ta\tchemical\tequation\tfor\tthe\treaction.  \t ...   [1]  (ii)\t\twhen\tiron(iii)\toxide\tis\tadded\tto\tdilute\tsulfuric\tacid,\tan\taqueous\tsolution\tof\tiron(iii)\tsulfate\t is\tformed\tas\tone\tof\tthe\tproducts. \t \twrite\ta\tchemical\tequation\tfor\tthe\treaction.  \t ...   [3]",
            "6": "6 0620/43/o/n/17 \u00a9 ucles 2017  (e)\t\taqueous\t sodium\thydroxide,\t aqueous\t potassium\t iodide\tand\taqueous\t acidified\t potassium\t manganate( vii)\tare\tadded\tto\taqueous\t solutions\t of\tiron(ii)\tsulfate\tand\t iron(iii)\tsulfate. \t \u25cf\t \tiron(ii)\tions,\tfe2+,\tare\treducing\tagents\tin\taqueous\tsolution. \t \u25cf\t \tiron(iii)\tions,\tfe3+,\tare\toxidising\tagents\t in\taqueous\tsolution. \t\tcomplete\tthe\ttable. reagentobservations\twith aqueous\tiron( ii)\tsulfateobservations\twith aqueous\tiron( iii)\tsulfate aqueous\tsodium\thydroxide green\tprecipitate aqueous\tpotassium\tiodide aqueous\tacidified potassium\tmanganate( vii)no\tchange [4] [total:\t22] 4  hydrogen\t and\toxygen\treact\ttogether\tin\ta\thydrogen\t fuel\tcell.\ta\thydrogen\t fuel\tcell\tis\tshown\tin\tthe\t diagram. membranewaterhydrogen h2oxygen o2v electrolyte  (a)\t\tname\tthe\tprocess\tby\twhich\toxygen\tis\tobtained\tfrom \tair.  \t..   [1]",
            "7": "7 0620/43/o/n/17 \u00a9 ucles 2017 [turn over  (b) (i)\t\tin\ta\thydrogen\t fuel\tcell,\tthe\thydrogen\t molecules\t are\tconverted\t into\thydrogen\t ions,\th+,\t according\tto\tthe\tionic\thalf-equation\tshown. h2    2h+  +  2e\u2013 \t \twhat\ttype\tof\treaction\tdoes\tthis\tionic\thalf-equation\trepresent?  \t ...   [1]  (ii)  what type\tof\tsubstance\treacts\tby\tdonating\thydrogen\tions,\th+?  \t ...   [1]  (c)\t\twrite\ta\tchemical\tequation\tfor\tthe\toverall\treaction\tthat\toccurs\tin\ta\thydrogen\tfuel\tcell.  \t..   [1]  (d)\t\thydrogen\tfuel\tcells\tare\tbeing\tdeveloped\tas\talternatives\tto\tpetrol\tengines\tin\tcars.  (i)\t\tgive\tone\tadvantage\tof\thydrogen\tfuel\tcells\tcompared\tto\tpetrol \tengines.  \t ...   [1]  (ii)\t\tgive\tone\tdisadvantage\tof\thydrogen\tfuel\tcells\tcompared\tto\tpetrol\tengines.  \t ...   [1]  (e)\t\tsome\tfuel\tcells\tuse\tethanol,\tc2h5oh,\tinstead\tof\thydrogen.\t carbon\tdioxide\tand\twater\tare\t products\tof\tthe\treaction\tin\tan\tethanol\tfuel\tcell.  (i)\t\twrite\ta\tchemical\tequation\tfor\tthe\toverall\treaction\toccurring\tin\tan\tethanol\tfuel\tcell.  \t ...   [2]  (ii)\t\tstate\tan\tenvironmental\t problem\tcaused\tby\tthe\trelease\tof\tcarbon\tdioxide\tinto\tthe\t atmosphere.  \t ...   [1]  (iii)\t\tname\tthe\tprocess\tby\twhich\tethanol\tcan \tbe\tmanufactured\tfrom\ta\trenewable\tresource.  \t ...   [1]  (f)\t\tname\tthe\tprocess\toccurring\twhen\telectrical\tenergy\tis\tused\tto\tbreak\tdown\tan\tionic\tcompound.  \t..   [1] [total:\t11]",
            "8": "8 0620/43/o/n/17 \u00a9 ucles 2017 5 (a) (i)\t name\tthe\tproducts\tformed\twhen\tsodium \tnitrate\tis\theated.  \t ...   [2]  (ii)\t\twhen\tcopper( ii)\tnitrate,\tcu(no3)2,\tundergoes\t thermal\tdecomposition,\t three\tproducts\tare\t formed.\tone\tof\tthe\tproducts\tis\tnitrogen\tdioxide,\tno2. \t \twrite\ta\tchemical\tequation\tfor\tthe\tthermal\tdecomposition\tof\tcopper( ii)\tnitrate.  \t ...   [2]  (b)\t\tthe\tchemical\tequation\tshows\tthe\tequilibrium\t between\tdinitrogen\t tetroxide\t(n2o4,\ta\tcolourless\t gas)\tand\tnitrogen\tdioxide\t(no2,\ta\tbrown\tgas). n2o4(g)\t\t   2no2(g)  colourless\t brown \t\ta\tmixture\tof\tdinitrogen\t tetroxide\tand\tnitrogen\tdioxide\tis\tallowed\tto\treach\tequilibrium\t in\ta\t closed\tgas\tsyringe.  (i)\t\tin\tchemistry,\twhat\tis\tmeant\tby\tthe\tterm\tequilibrium ?  \t .  \t .  \t ...   [2]  (ii)\t\tif\tthe\tequilibrium\t mixture\tis\theated\tat\tconstant\tpressure,\t a\tdarker\tbrown\tcolour\tis\tseen\t inside\tthe\tgas\tsyringe. \t \twhat\tdoes\tthis\tinformation\tindicate\tabout\tthe\tdecomposition\tof\tdinitrogen\ttetroxide? \t \texplain\tyour\tanswer\tin\tterms\tof\tthe\tposition\tof\tthe\tequilibrium.  \t .  \t .  \t ...   [2]  (iii)\t\tsuggest\twhat\tyou\twould\tsee\tif\tthe\tpressure\ton\tthe\tequilibrium\t mixture\twere\tincreased\t at\t constant\ttemperature. \t \texplain\tyour\tanswer\tin\tterms\tof\tthe\tposition\tof\tthe\tequilibrium.  \t .  \t .  \t ...   [2] [total:\t10]",
            "9": "9 0620/43/o/n/17 \u00a9 ucles 2017 [turn over 6 (a)\t\talkanes\tand\talkenes\tare\ttwo\thomologous\tseries\tof \thydrocarbons.  (i)\t\twhat\tis\tmeant\tby\tthe\tterm\thydrocarbon ?  \t ...   [1]  (ii)\t\twhat\tis\tthe\tgeneral\tformula\tof\tthe\thomologous\tseries\tof \t alkanes,\t\t .. \t alkenes?\t\t . [2]  (iii)\t\tother\tthan\thaving\ta\tgeneral\tformula,\tstate\ttwo\tcharacteristics\tof\ta\thomologous\tseries.  1 \t ..  2 \t .. [2]  (iv)\t\tthe\tstructure\tof\tan\talkene\tmolecule\twith \tthe\tmolecular\tformula\tc4h8\tis\tshown. hch ch hch hch h \t \tdraw\tthe\tstructure\tof\ta\tdifferent\talkene\tmolecule\twith\tthe\tmolecular\t formula\tc4h8.\tshow\t all\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds. [1]  (v)\t\twhat\tterm\tdescribes\t molecules\t with\tthe\tsame\tmolecular\t formula\tbut\tdifferent\tstructural\t formulae?  \t ...   [1]",
            "10": "10 0620/43/o/n/17 \u00a9 ucles 2017  (b)\t\t25\tcm3\tof\ta\tgaseous\thydrocarbon,\t cxhy,\twere\tburnt\tin\t150\tcm3\tof\toxygen.\tthis\twas\tan\texcess\t of\toxygen. \t\tafter\tcooling,\tthe\tvolume\tof\tthe\tgases\tremaining\t was\t100\tcm3.\tthis\tconsisted\t of\t75\tcm3\tof\t carbon\tdioxide\tand\t25\tcm3\tof\tunreacted\t oxygen.\tthe\twater\tthat\twas\tproduced\t in\tthe\treaction\t was\tliquid. \t\tall\tvolumes\twere\tmeasured\tat\tthe\tsame\ttemperature\tand\tpressure.  (i)\t\twhat\tis\tmeant\tby\tan\texcess\tof\toxygen?  \t ...   [1]  (ii)\t\twhat\twas\tthe\tvolume\tof\toxygen\tthat\treacted\twith\tthe\thydrocarbon? .\tcm3  [1]  (iii)\t\tcomplete\tthe\ttable\tto\tshow\tthe\tsmallest \twhole\tnumber\tratio\tof\tvolumes. volume\tof hydrocarbon\treacted:volume\tof oxygen\treacted:volume\tof\t  carbon\tdioxide\t produced smallest\twhole\t number\tratio\tof\t volumes: : [1]  (iv)\t\tuse\tyour\tanswer\tto\t(b)(iii)\tto\tbalance\tthe\tchemical\tequation.\t deduce\tthe\tformula\tof\tthe\t hydrocarbon. cxhy(g)\t\t+\t\t..o2(g)\t\t\t\t..co2(g)\t\t+\t\t..h2o(l) formula\tof\tthe\thydrocarbon\t=\t.\t\t[2] [total:\t12]",
            "11": "11 0620/43/o/n/17 \u00a9 ucles 2017to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. 7 (a)\t\tcarbon\tand\tsilicon\tare\telements\tin\tgroup\tiv\tof\tthe\t periodic\ttable. \t\tcarbon\tdioxide\tfrom\tthe\tair\tmoves\tinto\tgreen\tplants\tand\tis\tconverted\tinto\tcarbohydrates.  (i)\t\tname\tthe\tprocess\tby\twhich\tcarbon\tdioxide\tmolecules\t move\tthrough\tthe\tair\tinto\tgreen\t plants.  \t ...   [1]  (ii)\t\texplain\twhy\tsilicon( iv)\toxide\t cannot\tmove\tthrough\tthe\tair\tin\tthe\tsame\tway\tthat\t carbon\tdioxide\tcan.  \t ...   [1]  (iii)\t\tname\tthe\tprocess\tby\twhich\tcarbon\tdioxide\tis\tconverted\t into\tglucose,\tc6h12o6,\tin\tgreen\t plants.\tgive\t two\tconditions\t required\tfor\tthis\tprocess\tto\toccur.\twrite\ta\tchemical\tequation\t for\tthe\treaction\twhich\toccurs. \t name\tof\tprocess\t\t  . \t condition\t1\t \t .. \t condition\t2\t \t .. \t chemical\tequation\t \t ... [5]  (b)\t\tstarch\tis\ta\tnatural\tpolymer\tmade\tfrom\tglucose.  (i)\t\twhat\ttype\tof\tpolymerisation\toccurs\twhen\tglucose\tis\tconverted\tinto\tstarch?  \t ...   [1]  (ii)\t\twhat\ttype\tof\treaction\toccurs\twhen\tstarch\tis\tconverted\tinto\tglucose?  \t ...   [1]  (iii)\t\tstarch\tcan\tbe\trepresented\tas\tshown. o o o o \t \tcomplete\tthe\tdiagram\tbelow\tto\trepresent\tthe\tstructure\tof\tthe\tglucose\tmonomer. [1] [total:\t10]",
            "12": "12 0620/43/o/n/17 \u00a9 ucles 2017 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w17_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5 practical test october/november 2017  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib17 11_0620_51/fp\u00a9 ucles 2017 *8318292337* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/51/o/n/17 \u00a9 ucles 2017 1  you are going to investigate what happens to the temperature when two different solids, w and x,  dissolve in water.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a) experiment 1 \t \u25cf\t \tput\tthe\tpolystyrene\tcup\tinto\tthe\t250\t cm3 beaker for support. \t \u25cf\t \tuse\tthe\tmeasuring\tcylinder\tto\tpour\t30\t cm3 of distilled water into the polystyrene cup.  \t \u25cf\t \tmeasure\tthe\tinitial\ttemperature\t of\tthe\twater\tand\trecord\tit\tin\tthe\ttable\tat\ttime\t=\t0\tseconds. \t \u25cf\t \tadd\tall\tof\tsolid\t w to the water, start the timer and stir the solution continuously with the  thermometer. \t \u25cf\t \tmeasure\tthe\ttemperature\tof\tthe\tsolution \tevery\t10\tseconds\tfor\t90\tseconds. \t \u25cf\t \trecord\tyour\tresults\tin\tthe\ttable. time / s 0102030405060708090 temperature of  the solution / \u00b0c [2]  (b) experiment 2 \t \u25cf\t \tempty\tthe\tpolystyrene\t cup\tand\trinse\tit\twith\twater.\tput\tthe\tpolystyrene\t cup\tback\tinto\tthe\t 250\tcm3 beaker. \t \u25cf\t \tuse\ta\tmeasuring\tcylinder\tto\tpour\t30\t cm3 of distilled water into the polystyrene cup. \t \u25cf\t \tmeasure\tthe\tinitial\ttemperature\t of\tthe\twater\tand\trecord\tit\tin\tthe\ttable\tat\ttime\t=\t0\tseconds. \t \u25cf\t \tadd\tall\tof\tsolid\t x to the water, start the timer and stir the solution continuously with the  thermometer.  \t \u25cf\t \tmeasure\tthe\ttemperature\tof\tthe\tsolution \tevery\t10\tseconds\tfor\t90\tseconds. \t \u25cf\t \trecord\tyour\tresults\tin\tthe\ttable.\t time / s 0102030405060708090 temperature of  the solution / \u00b0c [2]",
            "3": "3 0620/51/o/n/17 \u00a9 ucles 2017 [turn over  (c)\t\tplot\tyour\tresults\tfor\texperiments\t1\tand\t2\ton\tthe\tgrid.\tdraw\ttwo smooth line graphs.   clearly label your lines. 0 20 40 60 time  / stemperature of the solution  / \u00b0c 80 10045 40 35 30 25 20 15 10 50 [4]  (d) (i)  from your graph,\t deduce\tthe\ttemperature\t of\tthe\tsolution\tin\texperiment\t 1\tafter\t15\tseconds.   show clearly on the grid  how you worked out your answer. .. \u00b0c\t\t[2]  (ii)  from your graph,\t deduce\tthe\ttime\ttaken\tfor\tthe\ttemperature\t of\tthe\tsolution\tin\texperiment\t 2\t to change by 6 \u00b0c from the initial temperature.   show clearly on the grid  how you worked out your answer. ..\ts\t\t[2]",
            "4": "4 0620/51/o/n/17 \u00a9 ucles 2017  (e)\t\tuse\tyour\tresults\tto\tidentify\tthe\ttype\tof\tenergy\tchange\tthat\toccurs\twhen\tsolid\t x dissolves in  water.   .. \t\t[1]  (f)\t\tpredict\tthe\ttemperature\tof\tthe\tsolution\tin\texperiment\t2\tafter\t1\thour.\texplain\tyour\tanswer.      .. \t\t[1]  (g)  state two sources of error in these experiments. give one improvement to reduce each of  these sources of error. \t source\tof\terror\t1\t  \t improvement\t1\t  ... \t source\tof\terror\t2\t \t improvement\t2\t  ... [4]  (h)  when carrying out the experiments, what would be a disadvantage of taking the temperature  readings\tonly\tevery\t30\tseconds?      .. \t\t[1] [total:\t19]",
            "5": "5 0620/51/o/n/17 \u00a9 ucles 2017 [turn over question 2 starts on the next page.",
            "6": "6 0620/51/o/n/17 \u00a9 ucles 2017 2  you are provided with two solutions, y and z.   carry out the following tests on the solutions, recording all of your observations at each stage.   tests on solution y \t\tdivide\tthe\tsolution\tinto\ttwo\tequal\tportions\tin\ttwo \ttest-tubes.  (a)\t\tdescribe\tthe\tappearance\tof\tsolution\t y.   .. \t\t[1]  (b) (i)\t\tadd\ta\tfew\tdrops\tof\taqueous\tsodium\thydroxide\t to\tthe\tfirst\tportion\tof\tsolution\t y and shake  the\ttest-tube\tto\tmix\tthe\tsolutions. \t \trecord\tyour\tobservations.   ... \t\t[2]  (ii)\t\tnow\tadd\tan \texcess\tof\taqueous\tsodium\t hydroxide\tto\tthe\tmixture. \t \trecord\tyour\tobservations.   ... \t\t[1]  (iii)\t\tpour\tthe\tmixture\tfrom\t (b)(ii)  into a boiling tube and add a small piece of aluminium foil.  heat the mixture carefully. test the gas produced with indicator paper. \t \trecord\tyour\tobservations.   .   ... \t\t[2]   keep the second portion of solution y for the test in (e).",
            "7": "7 0620/51/o/n/17 \u00a9 ucles 2017 [turn over  tests on solution z \t\tdivide\tthe\tsolution\tinto\tthree\tequal\tportions\tin\tthree\ttest-tubes.  (c)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tz. \t\trecord\tyour\tobservations.   .. \t\t[1]  (d) (i)\t\tadd\ta\tfew\tdrops\tof\taqueous\tcopper( ii) sulfate to the second portion of solution z. \t \trecord\tyour\tobservations.   ... \t\t[1]  (ii)\t\tnow\tadd\tan \texcess\tof\taqueous\tcopper( ii) sulfate to the mixture. \t \trecord\tyour\tobservations.   ... \t\t[2]  (e)  to the third portion of solution z, add the second portion of solution y. \t\trecord\tyour\tobservations.   .. \t\t[2]  (f)  identify solution y.   .. \t\t[2]  (g)  identify solution z.   .. \t\t[1] [total:\t15]",
            "8": "8 0620/51/o/n/17 \u00a9 ucles 2017 3  washing soda crystals are crystals of hydrated sodium carbonate, na2co3.10h2o. when exposed  to the air, some of the water is lost from the crystals and a new substance is formed. this process  occurs faster in hotter climates. \t\tplan\tan\texperiment\tto\tdetermine\tthe\tpercentage \tof\twater\tby\tmass\tpresent\tin\tthe\tnew\tsubstance.   you are provided with common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6] [total:\t6]",
            "9": "9 0620/51/o/n/17 \u00a9 ucles 2017blank page",
            "10": "10 0620/51/o/n/17 \u00a9 ucles 2017blank page",
            "11": "11 0620/51/o/n/17 \u00a9 ucles 2017notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/51/o/n/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_w17_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5 practical test october/november 2017  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib17 11_0620_52/4rp\u00a9 ucles 2017 *2908845984* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/52/o/n/17 \u00a9 ucles 2017 1  you are going to investigate what happens when two different solids, s and t, dissolve in water.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a) experiment 1 \t \u25cf\t \tput\tthe\tpolystyrene\tcup\tinto\tthe\t250\t cm3 beaker for support. \t \u25cf\t \tuse\tthe\tmeasuring\tcylinder\tto\tpour\t30\t cm3 of distilled water into the polystyrene cup. \t \u25cf\t \tmeasure\tthe\tinitial\ttemperature\tof\tthe\twater\tand\trecord\tit\tin\tthe\tfirst\trow\tof\tthe\ttable. \t \u25cf\t \tadd\tthe\t2.0\tg\tsample\tof\tsolid\t s to the polystyrene cup and stir the solution with the  thermometer. \t \u25cf\t \tmeasure\tand\trecord\tthe\t maximum temperature of the solution. \t \u25cf\t \tpour\tthe\tsolution\taway\tand\trinse\tout\tthe \tpolystyrene\tcup\twith\tdistilled\twater. \t \u25cf\t \trepeat\tthe\tprocedure\t using\tthe\t3.0\tg\tsample\tof\tsolid\t s.\trecord\tyour\tresults\tin\tthe\t appropriate row of the table. \t \u25cf\t \trepeat\tthe\tprocedure\t using\tthe\t5.0\tg\tsample\tof\tsolid\t s.\trecord\tyour\tresults\tin\tthe\t appropriate row of the table. mass of solid s / ginitial temperature of the water / \u00b0cmaximum temperature of the solution / \u00b0c 2.0 3.05.0 [2]  (b) experiment 2 \t \u25cf\t \tput\tthe\tpolystyrene\tcup\tinto\tthe\t250\t cm 3 beaker for support. \t \u25cf\t \tuse\tthe\tmeasuring\tcylinder\tto\tpour\t30\t cm3 of distilled water into the polystyrene cup. \t \u25cf\t \tmeasure\tthe\tinitial\ttemperature\tof\tthe\twater\tand\trecord\tit\tin\tthe\tfirst\trow\tof\tthe\ttable. \t \u25cf\t \tadd\tthe\t2.0\tg\tsample\tof\tsolid\t t to the polystyrene cup and stir the solution with the  thermometer. \t \u25cf\t \tmeasure\tand\trecord\tthe\t minimum temperature of the solution. \t \u25cf\t \tpour\tthe\tsolution\taway\tand\trinse\tout\tthe \tpolystyrene\tcup\twith\tdistilled\twater. \t \u25cf\t \trepeat\tthe\tprocedure\tusing\tthe\t3.0\t g\tsample\tof\tsolid\t t. \t \u25cf\t \trepeat\tthe\tprocedure\tusing\tthe\t4.0\t g\tsample\tof\tsolid\t t. \t \u25cf\t \trepeat\tthe\tprocedure\tusing\tthe\t6.0\t g\tsample\tof\tsolid\t t. \t \u25cf\t \trecord\tyour\tresults\tin\tthe\tappropriate\trows\tof\tthe\ttable. mass of solid t / ginitial temperature of the water / \u00b0cminimum temperature of the solution / \u00b0c 2.0 3.0 4.0 6.0 [2]",
            "3": "3 0620/52/o/n/17 \u00a9 ucles 2017 [turn over  (c)\t\tplot\tyour\tresults\tfor\texperiment\t 1\t(maximum\t temperature)\t and\texperiment\t 2\t(minimum\t temperature)\ton\tthe\tgrid.\tdraw\t two\tstraight\tlines\tof\tbest\tfit.   clearly label your lines. 0.0 1.0 2.0 3.0 mass of solid  / gtemperature of the solution  / \u00b0c 4.0 5.0 6.0 7.060 50 40 302010 0 [4]  (d) (i)  from your graph,\t deduce\tthe\tmaximum\t temperature\t of\tthe\tsolution\t if\t6.0\tg\tof\tsolid\t s  were\tadded\tto\t30\t cm 3 of distilled water.   show clearly on the grid  how you worked out your answer. .. \u00b0c\t\t[2]  (ii)  from your graph,\t deduce\tthe\tminimum \ttemperature\t of\tthe\tsolution\tif\t4.5\tg\tof\tsolid\t t were  added\tto\t30\t cm3 of distilled water.   show clearly on the grid  how you worked out your answer. .. \u00b0c\t\t[2]  (e)\t\tuse\tyour\tresults\tto\tidentify\tthe\ttype\tof\tenergy\tchange\tthat\toccurs\twhen\tsolid\t s dissolves in  water.   .. \t\t[1]",
            "4": "4 0620/52/o/n/17 \u00a9 ucles 2017  (f)  suggest one change you could make to the experiments to obtain more accurate results.  explain\thow\tthis\tchange\twould\tmake\tthe\tresults\tmore\taccurate.  change  ...  explanation      [2]  (g)  suggest how the reliability of the results could be checked.   .. \t\t[1]  (h)\t\texplain\thow\tthe\ttemperatures\t measured\t would\tbe\tdifferent\t if\texperiment\t 1\twere\trepeated\t using\t60\t cm3 of distilled water in each case.      .. \t\t[2] [total:\t18]",
            "5": "5 0620/52/o/n/17 \u00a9 ucles 2017 [turn over question 2 starts on the next page.",
            "6": "6 0620/52/o/n/17 \u00a9 ucles 2017 2  you are provided with two solid salts, u and w.   carry out the following tests on solid u and solid w, recording all of your observations at each  stage.   tests on solid u  (a)\t\tdescribe\tthe\tappearance\tof\tsolid\t u.   .. \t\t[1] \t\tadd\tabout\thalf\tof\tsolid\t u\tto\tabout\t5\tcm3 of distilled water in a test-tube. stopper the test-tube and  shake it to dissolve solid u and form solution u. \t\tdivide\tsolution\t u into two equal portions in two test-tubes and carry out the following tests.  (b)  to\tthe\tfirst\tportion\tof\tsolution\tu,\tadd\tabout\t1\t cm3 of dilute hydrochloric acid.   test the gas produced. \t \trecord\tyour\tobservations.      .. \t\t[3]   keep the second portion of solution u for the test in (g)(i).  (c)  identify the gas produced in (b).   .. \t\t[1]  (d)\t\tcarry\tout\ta\tflame\ttest\ton\tsolid\tu. \t \trecord\tyour\tobservations.   .. \t\t[1]  (e)  identify solid u.   .. \t\t[2]",
            "7": "7 0620/52/o/n/17 \u00a9 ucles 2017 [turn over   tests on solid w \t\tadd\tabout\thalf\tof\tsolid\t w\tto\tabout\t5\tcm3 of distilled water in a test-tube. stopper the test-tube and  shake it to dissolve solid w and form solution w. \t\tdivide\tsolution\t w into two equal portions in two test-tubes and carry out the following tests.  (f)  to\tthe\tfirst\tportion\tof\tsolution\t w,\tadd\ta\tfew\tdrops\tof\tdilute\tnitric\tacid\tand\tabout\t1\tcm3 of  aqueous silver nitrate. \t \trecord\tyour\tobservations.   .. \t\t[2]  (g) (i)  to the second portion of solution w, add the second portion of solution u. \t \trecord\tyour\tobservations.   ... \t\t[2]  (ii)  now add an excess of dilute hydrochloric acid to the mixture from (g)(i). \t \trecord\tyour\tobservations.   ... \t\t[2]  (h)  what conclusions can you draw about solid w?      .. \t\t[2] [total:\t16]",
            "8": "8 0620/52/o/n/17 \u00a9 ucles 2017 3  when iron nails rust, the mass of the nails increases. \t\tplan\tan\texperiment\tto\tinvestigate\tif\tiron\tnails\trust\tmore\tquickly\tin\ttap\twater\tor\tin\tdistilled\twater.   you are provided with new iron nails and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6] [total:\t6]",
            "9": "9 0620/52/o/n/17 \u00a9 ucles 2017blank page",
            "10": "10 0620/52/o/n/17 \u00a9 ucles 2017blank page",
            "11": "11 0620/52/o/n/17 \u00a9 ucles 2017notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/52/o/n/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_w17_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5 practical test october/november 2017  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib17 11_0620_53/4rp\u00a9 ucles 2017 *4303303595* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/53/o/n/17 \u00a9 ucles 2017 1  you are going to investigate what happens to the temperature when two different solids, w and x,  dissolve in water.   read all the instructions carefully before starting the experiments.   instructions   you are going to carry out two experiments.  (a) experiment 1 \t \u25cf\t \tput\tthe\tpolystyrene\tcup\tinto\tthe\t250\t cm3 beaker for support. \t \u25cf\t \tuse\tthe\tmeasuring\tcylinder\tto\tpour\t30\t cm3 of distilled water into the polystyrene cup.  \t \u25cf\t \tmeasure\tthe\tinitial\ttemperature\t of\tthe\twater\tand\trecord\tit\tin\tthe\ttable\tat\ttime\t=\t0\tseconds. \t \u25cf\t \tadd\tall\tof\tsolid\t w to the water, start the timer and stir the solution continuously with the  thermometer. \t \u25cf\t \tmeasure\tthe\ttemperature\tof\tthe\tsolution \tevery\t10\tseconds\tfor\t90\tseconds. \t \u25cf\t \trecord\tyour\tresults\tin\tthe\ttable. time / s 0102030405060708090 temperature of  the solution / \u00b0c [2]  (b) experiment 2 \t \u25cf\t \tempty\tthe\tpolystyrene\t cup\tand\trinse\tit\twith\twater.\tput\tthe\tpolystyrene\t cup\tback\tinto\tthe\t 250\tcm3 beaker. \t \u25cf\t \tuse\ta\tmeasuring\tcylinder\tto\tpour\t30\t cm3 of distilled water into the polystyrene cup. \t \u25cf\t \tmeasure\tthe\tinitial\ttemperature\t of\tthe\twater\tand\trecord\tit\tin\tthe\ttable\tat\ttime\t=\t0\tseconds. \t \u25cf\t \tadd\tall\tof\tsolid\t x to the water, start the timer and stir the solution continuously with the  thermometer.  \t \u25cf\t \tmeasure\tthe\ttemperature\tof\tthe\tsolution \tevery\t10\tseconds\tfor\t90\tseconds. \t \u25cf\t \trecord\tyour\tresults\tin\tthe\ttable.\t time / s 0102030405060708090 temperature of  the solution / \u00b0c [2]",
            "3": "3 0620/53/o/n/17 \u00a9 ucles 2017 [turn over  (c)\t\tplot\tyour\tresults\tfor\texperiments\t1\tand\t2\ton\tthe\tgrid.\tdraw\ttwo smooth line graphs.   clearly label your lines. 0 20 40 60 time  / stemperature of the solution  / \u00b0c 80 10045 40 35 30 25 20 15 10 50 [4]  (d) (i)  from your graph,\t deduce\tthe\ttemperature\t of\tthe\tsolution\tin\texperiment\t 1\tafter\t15\tseconds.   show clearly on the grid  how you worked out your answer. .. \u00b0c\t\t[2]  (ii)  from your graph,\t deduce\tthe\ttime\ttaken\tfor\tthe\ttemperature\t of\tthe\tsolution\tin\texperiment\t 2\t to change by 6 \u00b0c from the initial temperature.   show clearly on the grid  how you worked out your answer. ..\ts\t\t[2]",
            "4": "4 0620/53/o/n/17 \u00a9 ucles 2017  (e)\t\tuse\tyour\tresults\tto\tidentify\tthe\ttype\tof\tenergy\tchange\tthat\toccurs\twhen\tsolid\t x dissolves in  water.   .. \t\t[1]  (f)\t\tpredict\tthe\ttemperature\tof\tthe\tsolution\tin\texperiment\t2\tafter\t1\thour.\texplain\tyour\tanswer.      .. \t\t[1]  (g)  state two sources of error in these experiments. give one improvement to reduce each of  these sources of error. \t source\tof\terror\t1\t  \t improvement\t1\t  ... \t source\tof\terror\t2\t \t improvement\t2\t  ... [4]  (h)  when carrying out the experiments, what would be a disadvantage of taking the temperature  readings\tonly\tevery\t30\tseconds?      .. \t\t[1] [total:\t19]",
            "5": "5 0620/53/o/n/17 \u00a9 ucles 2017 [turn over question 2 starts on the next page.",
            "6": "6 0620/53/o/n/17 \u00a9 ucles 2017 2  you are provided with two solutions, y and z.   carry out the following tests on the solutions, recording all of your observations at each stage.   tests on solution y \t\tdivide\tthe\tsolution\tinto\ttwo\tequal\tportions\tin\ttwo \ttest-tubes.  (a)\t\tdescribe\tthe\tappearance\tof\tsolution\t y.   .. \t\t[1]  (b) (i)\t\tadd\ta\tfew\tdrops\tof\taqueous\tsodium\thydroxide\t to\tthe\tfirst\tportion\tof\tsolution\t y and shake  the\ttest-tube\tto\tmix\tthe\tsolutions. \t \trecord\tyour\tobservations.   ... \t\t[2]  (ii)\t\tnow\tadd\tan \texcess\tof\taqueous\tsodium\t hydroxide\tto\tthe\tmixture. \t \trecord\tyour\tobservations.   ... \t\t[1]  (iii)\t\tpour\tthe\tmixture\tfrom\t (b)(ii)  into a boiling tube and add a small piece of aluminium foil.  heat the mixture carefully. test the gas produced with indicator paper. \t \trecord\tyour\tobservations.   .   ... \t\t[2]   keep the second portion of solution y for the test in (e).",
            "7": "7 0620/53/o/n/17 \u00a9 ucles 2017 [turn over  tests on solution z \t\tdivide\tthe\tsolution\tinto\tthree\tequal\tportions\tin\tthree\ttest-tubes.  (c)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tz. \t\trecord\tyour\tobservations.   .. \t\t[1]  (d) (i)\t\tadd\ta\tfew\tdrops\tof\taqueous\tcopper( ii) sulfate to the second portion of solution z. \t \trecord\tyour\tobservations.   ... \t\t[1]  (ii)\t\tnow\tadd\tan \texcess\tof\taqueous\tcopper( ii) sulfate to the mixture. \t \trecord\tyour\tobservations.   ... \t\t[2]  (e)  to the third portion of solution z, add the second portion of solution y. \t\trecord\tyour\tobservations.   .. \t\t[2]  (f)  identify solution y.   .. \t\t[2]  (g)  identify solution z.   .. \t\t[1] [total:\t15]",
            "8": "8 0620/53/o/n/17 \u00a9 ucles 2017 3  washing soda crystals are crystals of hydrated sodium carbonate, na2co3.10h2o. when exposed  to the air, some of the water is lost from the crystals and a new substance is formed. this process  occurs faster in hotter climates. \t\tplan\tan\texperiment\tto\tdetermine\tthe\tpercentage \tof\twater\tby\tmass\tpresent\tin\tthe\tnew\tsubstance.   you are provided with common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6] [total:\t6]",
            "9": "9 0620/53/o/n/17 \u00a9 ucles 2017blank page",
            "10": "10 0620/53/o/n/17 \u00a9 ucles 2017blank page",
            "11": "11 0620/53/o/n/17 \u00a9 ucles 2017notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/53/o/n/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_w17_qp_61.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib17 11_0620_61/3rp \u00a9 ucles 2017 *4473552331* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6 alternative to practical october/november 2017  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/61/o/n/17 \u00a9 ucles 2017 1  a student reacted dilute hydrochloric acid with zinc oxide to prepare zinc chloride solution.   the diagram shows part of the procedure. zinc chloride solution unreacted zinc oxide funnel .  (a)  complete the box to name the apparatus. [1]  (b)  which of the reactants was in excess?   ..   [1]  (c) (i)  name the separation process this apparatus is used for.   ...   [1]  (ii)  suggest why this apparatus would not work.   .   ...   [1]  (d)  describe how crystals of zinc chloride could be obtained from the zinc chloride solution.         ..   [3] [total: 7]",
            "3": "3 0620/61/o/n/17 \u00a9 ucles 2017 [turn over 2  a student investigated the rate of reaction between dilute hydrochloric acid and aqueous  sodium thiosulfate. when these chemicals react they form a precipitate which makes the solution  go cloudy. the formation of this precipitate can be used to show how fast the reaction proceeds.   five experiments were carried out using the apparatus shown. aqueous sodium thiosulfat eeye 10 cm3 of dilute hydrochloric acid 250  cm3 conical flas k sheet of paper wit h words printed on it   experiment 1 \t \u25cf\t \tusing\ta\tmeasuring\t cylinder,\t 50\tcm3 of aqueous sodium thiosulfate were poured into a conical  flask.\tthe\tinitial\ttemperature\t of\tthe\tsolution\twas\tmeasured.\t the\tconical\tflask\twas\tplaced\ton\ta\t sheet of paper with words printed on it. \t \u25cf\t \tusing\ta\tmeasuring \tcylinder,\t 10\tcm3 of dilute hydrochloric acid were added to the solution in the  conical\tflask\tand\ta\tstopclock\twas\tstarted. \t \u25cf\t \tthe\ttime\ttaken\tfor\tthe\tprinted\twords\tto\tdisappear\tfrom\tview\twas\tmeasured. \t \u25cf\t \tthe\tfinal\ttemperature\tof\tthe\tmixture\twas\tmeasured.  experiment 2 \t \u25cf\t \tusing\ta\tmeasuring\t cylinder,\t 50\tcm3 of aqueous sodium thiosulfate were poured into a conical  flask.\tthe\tsolution\twas\theated\tto\tabout\t 30 \u00b0c and the temperature was measured. the conical  flask\twas\tplaced\ton\ta\tsheet\tof\tpaper\twith\twords\tprinted\ton\tit. \t \u25cf\t \tusing\ta\tmeasuring \tcylinder,\t 10\tcm3 of dilute hydrochloric acid were added to the solution in the  conical\tflask\tand\ta\tstopclock\twas\tstarted. \t \u25cf\t \tthe\ttime\ttaken\tfor\tthe\tprinted\twords\tto\tdisappear\tfrom\tview\twas\tmeasured. \t \u25cf\t \tthe\tfinal\ttemperature\tof\tthe\tmixture\twas\tmeasured.  experiment 3 \t \u25cf\t \texperiment\t 2\twas\trepeated\t but\tthe\t50\tcm3 of aqueous sodium thiosulfate were heated to about  40 \u00b0c before adding the dilute hydrochloric acid.   experiment 4 \t \u25cf\t \texperiment\t 2\twas\trepeated\t but\tthe\t50\tcm3 of aqueous sodium thiosulfate were heated to about  50 \u00b0c before adding the dilute hydrochloric acid.   experiment 5 \t \u25cf\t \texperiment\t 2\twas\trepeated\t but\tthe\t50\tcm3 of aqueous sodium thiosulfate were heated to about  60 \u00b0c before adding the dilute hydrochloric acid.",
            "4": "4 0620/61/o/n/17 \u00a9 ucles 2017  (a)  calculate the average temperatures and record them in the table. \t \tuse\tthe\tstopclock\tdiagrams\tto\trecord\tthe\ttimes\tin\tthe\ttable. 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5 0 0 10 3015 1545 5seconds minutesexperiment number 1stopclock diagramtime taken for the printed words to disappear from view  / sinitial temperature of the solution  / \u00b0cfinal temperature of the mixture  / \u00b0caverage temperature / \u00b0c 2 3 4 519 32 42 54 6517 30 40 52 61 [3]",
            "5": "5 0620/61/o/n/17 \u00a9 ucles 2017 [turn over  (b)\t\tplot\tthe\tresults\tof\texperiments\t1\u20135\ton\tthe\tgrid.\tdraw\ta\tsmooth\tline\tgraph. 0 10 20 30 40 average temperature  / \u00b0c50 60 70 80240 210 180 150 120 90 60 30 0time taken for the printed words todisappearfrom view  / s [4]  (c)  from your graph,\t deduce\tthe\ttime\ttaken\tfor\tthe\tprinted\twords\tto\tdisappear\t from\tview\twhen\t experiment\t 2\twas\trepeated\t at\tan\tinitial\ttemperature \tof\t73\t\u00b0c.\tthe\tfinal\ttemperature\t of\tthe\t mixture was 71 \u00b0c.   show clearly on the grid  how you worked out your answer.   ..   [3]  (d)  sketch on the grid the graph you would expect if all of the experiments were repeated using  a more dilute solution of aqueous sodium thiosulfate. [1]",
            "6": "6 0620/61/o/n/17 \u00a9 ucles 2017  (e) (i)\t \tin\twhich\texperiment,\t1,\t2,\t3,\t4\tor\t5,\twas\tthe\trate\tof\treaction\tgreatest?   ...   [1]  (ii)\t\texplain,\tin\t terms\tof\tparticles,\twhy\tthe\trate\tof\treaction\twas\tgreatest\tin\tthis\texperiment.   .   .   .   ... \t\t[2]  (f)  suggest and explain the effect on the results of using  (i)\t\ta\tburette\tto\tmeasure\tthe\tvolumes,   .   .   ... \t\t[2]  (ii)\t\ta\t100\tcm3\tconical\tflask\tinstead\tof\ta\t250\t cm3\tconical\tflask.   .   .   ... \t\t[2] [total: 18]",
            "7": "7 0620/61/o/n/17 \u00a9 ucles 2017 [turn over 3\t\ttwo\tsolid\tsalts,\tf and g,\twere\tanalysed.\tsolid\t f was iron( iii) nitrate.   tests were carried out on each solid.  tests on solid f   complete the expected observations.   solid f was dissolved in distilled water to produce solution  f. solution f was divided into three  equal portions in three test-tubes.  (a) (i)\t \ta\tfew\tdrops\tof\taqueous\t sodium\thydroxide\t were\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t f until  a change was seen.  observations  . \t\t[2]  (ii)  an excess of aqueous sodium hydroxide was then added to the mixture from (a)(i).  observations  ..   [1]  (b)  an excess of aqueous ammonia was added to the second portion of solution f until a change  was seen.  observations  .   [1]  (c)  aluminium foil and aqueous sodium hydroxide were added to the third portion of solution f.  the mixture was heated and the gas which was produced was tested.  test for gas  .  test result  ... [2]  (d)  identify the gas produced in (c).   ..   [1]  tests on solid g   tests were carried out and the following observations made. tests on solid g observations test 1 a\tflame\ttest\twas\tcarried\tout\ton\tsolid\t g. red colour test 2dilute nitric acid was added to solid g. the gas produced was passed through limewater.rapid effervescence limewater turned milky  (e)  identify solid g.   .. \t\t[2] [total: 9]",
            "8": "8 0620/61/o/n/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 4\t\tiron,\ttin\tand\tzinc\tall\treact\twith\tdilute\thydrochloric \tacid\tto\tproduce\thydrogen. \t\tplan\tan\texperiment\tto\tdetermine\tthe\torder\tof\treactivity\tof\tiron,\ttin\tand\tzinc.   you are provided with powdered samples of the metals and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]"
        },
        "0620_w17_qp_62.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib17 11_0620_62/4rp \u00a9 ucles 2017 *1525169577* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6 alternative to practical october/november 2017  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/o/n/17 \u00a9 ucles 2017 1  some magnesium ribbon was cleaned.   steam was then passed over the magnesium ribbon as it was heated, using the apparatus shown. mineral wool magnesium ribbon .  (a)  what liquid is absorbed on the mineral wool?   ..   [1]  (b) (i) use two arrows to show two places where heat is applied. [1]  (ii)  complete the box to name the apparatus. [1]  (c)  suggest how the magnesium ribbon was cleaned.   ..   [1]  (d) (i)  complete the diagram to show how the hydrogen produced could be collected and its  volume measured. label your diagram. [2]   (ii)  state the effect of a lighted splint on the hydrogen produced.   ...   [1]  (e)  suggest why the tube containing the magnesium cracks after the reaction.      ..   [1] [total: 8]",
            "3": "3 0620/62/o/n/17 \u00a9 ucles 2017 [turn over 2  a student investigated what happened when two different solids, s and t, dissolved in water.   two experiments were carried out.  experiment 1 \t \u25cf\t \tusing\ta\tmeasuring\t cylinder,\t 30\tcm3 of distilled water were poured into a polystyrene cup. the  initial temperature of the water was measured. \t \u25cf\t \t2.0\tg\tof\tsolid\t s were added to the polystyrene cup and the solution was stirred with a  thermometer. \t \u25cf\t \tthe\tmaximum temperature of the solution was measured. \t \u25cf\t \tthe\tsolution\twas\tpoured\taway\tand\tthe\tpolystyrene\tcup\twas\trinsed\tout\twith\tdistilled\twater. \t \u25cf\t \tthe\tprocedure\twas\trepeated\tusing\t3.0\t g\tof\tsolid\ts. \t \u25cf\t \tthe\tprocedure\twas\trepeated\tusing\t5.0\t g\tof\tsolid\ts.  (a)  use the thermometer diagrams to record the temperatures in the table. 2.0 3.0 5.0mass of solid s  / ginitial temperature of the water  / \u00b0cthermometer diagramthermometer diagrammaximum temperature of the solution  / \u00b0c 30 25 2040 35 30 30 25 2040 35 30 30 25 2055 50 45 [2]",
            "4": "4 0620/62/o/n/17 \u00a9 ucles 2017  experiment 2 \t \u25cf\t \texperiment\t 1\twas\trepeated\t using\t2.0\tg,\t3.0\tg,\t4.0\tg\tand\t6.0\tg\tof\tsolid\t t. the minimum  temperature of the solution was measured in each case.  (b)  use the thermometer diagrams to record the temperatures in the table. 2.0 3.0 4.0 6.0mass of solid t  / ginitial temperature of the water  / \u00b0cthermometer diagramthermometer diagramminimum temperature of the solution  / \u00b0c 30 25 2025 20 15 30 25 2020 15 10 30 25 2020 15 10 30 25 2020 15 10 [2]",
            "5": "5 0620/62/o/n/17 \u00a9 ucles 2017 [turn over  (c)\t\tplot\tthe\tresults\tof\texperiment\t 1\t(maximum\t temperature)\t and\texperiment\t 2\t(minimum\t temperature)\ton\tthe\tgrid.\tdraw\t two\tstraight\tlines\tof\tbest\tfit.   clearly label your lines. 0.0 1.0 2.0 3.0 4.0temperature of the solution  / \u00b0c mass of solid  / g5.0 6.0 7.070 60 50 40 30 2010 0 [4]  (d) (i)  from your graph,\t deduce\tthe\tmaximum\t temperature\t of\tthe\tsolution\t if\t6.0\tg\tof\tsolid\t s  were\tadded\tto\t30\t cm 3 of distilled water.   show clearly on the grid  how you worked out your answer. .. \u00b0c  [2]  (ii)  from your graph,\t deduce\tthe\tminimum \ttemperature\t of\tthe\tsolution\tif\t4.5\tg\tof\tsolid\t t were  added\tto\t30\t cm3 of distilled water.   show clearly on the grid  how you worked out your answer. .. \u00b0c  [2]",
            "6": "6 0620/62/o/n/17 \u00a9 ucles 2017  (e)  use the results to identify the type of energy change that occurs when solid s dissolves in  water.   ..   [1]  (f)  suggest one change you could make to the experiments to obtain more accurate results.  explain\thow\tthis\tchange\twould\tmake\tthe\tresults\tmore\taccurate.  change  ...  explanation      [2]  (g)  suggest how the reliability of the results could be checked.   ..   [1]  (h)\t\texplain\thow\tthe\ttemperatures\t measured\t would\tbe\tdifferent\t if\texperiment\t 1\twere\trepeated\t using\t60\t cm3 of distilled water in each case.      ..   [2] [total: 18]",
            "7": "7 0620/62/o/n/17 \u00a9 ucles 2017 [turn over 3  two solid salts, u and w, were analysed. solid u was sodium carbonate.   tests were carried out on each solid.   tests on solid u   complete the expected observations.  (a)\t\tdescribe\tthe\tappearance\tof\tsolid\t u.   ..   [1]   about half of solid u was dissolved in distilled water to produce solution u. solution u was divided  into two equal portions in two test-tubes.  (b)\t\tdilute\thydrochloric\tacid\twas\tadded\tto\tthe\tfirst\tportion\tof\tsolution\tu.   the gas produced was tested.  observations  ..   .. \t\t[3]  (c)  name the gas produced in (b).   ..   [1]  (d)\t\ta\tflame\ttest\twas\tcarried\tout\ton\tsolid\t u.  observations  .   [1]  tests on solid w  tests were carried out and the following observations made. tests on solid w observations appearance of solid w. white crystals solid w was dissolved in distilled water to produce  solution w. the solution was divided into two equal  portions in two test-tubes. test 1dilute\tnitric\tacid\tand\taqueous\t silver\tnitrate\twere\tadded\t to\tthe\tfirst\tportion\tof\tsolution\tw.white precipitate formed test 2the second portion of solution u was added to the  second portion of solution w. an excess of dilute hydrochloric acid was then added  to the mixture.white precipitate formed rapid effervescence white precipitate dissolved  (e)  what conclusions can you draw about solid w?   ..   [2] [total: 8]",
            "8": "8 0620/62/o/n/17 \u00a9 ucles 2017permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 4  when iron nails rust, the mass of the nails increases.   plan an experiment to investigate if iron nails rust more quickly in tap water or in distilled water.   you are provided with new iron nails and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6] [total:\t6]"
        },
        "0620_w17_qp_63.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib17 11_0620_63/3rp \u00a9 ucles 2017 *4976035785* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6 alternative to practical october/november 2017  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/63/o/n/17 \u00a9 ucles 2017 1  cerussite is a lead ore which contains lead( ii) carbonate. a student obtained a solution of  lead( ii) nitrate from cerussite using the apparatus shown. step 1 step 2 step 3dilute acid cerussite..  (a)  complete the boxes to name the apparatus. [2]  (b)  why was the cerussite crushed in step 1?   ..   [1]  (c)  name the dilute acid used in step 2.   ..   [1]  (d)\t\twhat\tis\tthe\tgeneral\tname\tgiven\tto\tan\tinsoluble\tsolid \tleft\ton\ta\tfilter\tpaper\tafter\tfiltration?   ..   [1]  (e)  suggest how a sample of lead could be obtained from the solution of lead( ii) nitrate.            ..   [2] [total: 7]",
            "3": "3 0620/63/o/n/17 \u00a9 ucles 2017 [turn over question 2 starts on the next page.",
            "4": "4 0620/63/o/n/17 \u00a9 ucles 2017 2  a student investigated what happened to the temperature when two different solids, w and x,  dissolved in water.   two experiments were carried out.  experiment 1 \t \u25cf\t\tusing\ta\tmeasuring\t cylinder,\t30\tcm3 of distilled water were poured into a polystyrene cup. the  initial\ttemperature\tof\tthe\twater\twas\tmeasured\tat\ttime\t=\t0\tseconds. \t \u25cf\t\tsolid\t w was added to the water, a timer was started and the solution was stirred with a  thermometer. \t \u25cf\t\tthe\ttemperature\tof\tthe\tsolution\twas\tmeasured\tevery\t10\tseconds\tfor\t90\tseconds.  (a)\t\tuse\tthe\tthermometer\tdiagrams\tto\trecord\tthe\ttemperatures\tin\tthe\ttable. 30 25 2020 15 1020 15 1020 15 1020 15 10thermometer diagramtime  / s0 10 20 30 40 50 60 70 80 90 temperature of the solution  / \u00b0c15 10 515 10 515 10 515 10 515 10 5 [2]  experiment 2  \u25cf  the polystyrene cup was emptied and rinsed with water.  \u25cf  experiment 1 was repeated using solid x.  \u25cf\t\tthe\ttemperature\tof\tthe\tsolution\twas\tmeasured\tevery\t10\tseconds\tfor\t90\tseconds .  (b)\t\tuse\tthe\tthermometer\tdiagrams\tto\trecord\tthe\ttemperatures\tin\tthe\ttable. 30 25 2030 25 2030 25 2035 30 2535 30 2535 30 2540 35 3040 35 3040 35 3040 35 30thermometer diagramtime  / s0 10 20 30 40 50 60 70 80 90 temperature of the solution  / \u00b0c [2]",
            "5": "5 0620/63/o/n/17 \u00a9 ucles 2017 [turn over  (c)  plot the results for experiments 1 and 2 on the grid. draw two smooth line graphs.   clearly label your lines. 40 30 20 10 0 02 04 06 08 0 time  / stemperature of the solution  / \u00b0c 100 [4]  (d) (i)  from your graph, deduce the temperature of the solution in experiment 1 after 15 seconds.   show clearly on the grid  how you worked out your answer. . \u00b0c  [2]  (ii)  from your graph, deduce the time taken for the temperature of the solution in experiment 2  to change by 6 \u00b0c from the initial temperature.   show clearly on the grid  how you worked out your answer. . s  [2]",
            "6": "6 0620/63/o/n/17 \u00a9 ucles 2017  (e)\t\tuse\tthe\tresults\tto\tidentify\tthe\ttype\tof\tenergy\tchange\tthat\toccurs\twhen\tsolid\t x dissolves in  water.   ..   [1]  (f)  predict the temperature of the solution in experiment 2 after 1 hour. explain your answer.      ..   [1]  (g)  state two sources of error in these experiments. give one improvement to reduce each of  these sources of error.  source of error 1    improvement 1  ...  source of error 2    improvement 2  ... [4]  (h)  when carrying out the experiments, what would be a disadvantage of taking the temperature  readings\tonly\tevery\t30\tseconds?      ..   [1] [total:\t19]",
            "7": "7 0620/63/o/n/17 \u00a9 ucles 2017 [turn over 3  two solutions, y and z, were analysed.   solution y was aqueous chromium( iii) nitrate.   tests were carried out on both solutions.  tests on solution y   complete the expected observations.   the solution was divided into two equal portions in two test-tubes.  (a) (i)\t\ta\tfew\tdrops\tof\taqueous\tsodium\thydroxide\t were\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t y and  the test-tube shaken to mix the solutions.  observations  .   [2]  (ii)  an excess of aqueous sodium hydroxide was then added to the mixture.  observations  ..   [1]  (iii)  the mixture from (a)(ii) was poured into a boiling tube and a small piece of aluminium foil  was added.   the mixture was heated and the gas produced was tested.  observations     ... \t\t[3]  (b)  identify the gas produced in (a)(iii).   ..   [1]",
            "8": "8 0620/63/o/n/17 \u00a9 ucles 2017  tests on solution z   tests were carried out and the following observations made. tests on solution z observations solution z was divided into three equal portions  in three test-tubes. test 1 the\tph\tof\tthe\tfirst\tportion\tof\tsolution\t z was  tested.ph\t10 test 2a few drops of aqueous copper( ii) sulfate were  added to the second portion of solution z. an excess of aqueous copper( ii) sulfate was  then added to the mixture.dark blue solution formed light blue precipitate formed test 3 the second portion of solution y was added to  the third portion of solution z.grey-green precipitate formed  (c)  identify solution z.   ..   [1] [total: 8]",
            "9": "9 0620/63/o/n/17 \u00a9 ucles 2017 [turn over 4  washing soda crystals are crystals of hydrated sodium carbonate, na2co3.10h2o. when exposed  to the air, some of the water is lost from the crystals and a new substance is formed. this process  occurs faster in hotter climates.   plan an experiment to determine the percentage of water by mass present in the new substance.   you are provided with common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "10": "10 0620/63/o/n/17 \u00a9 ucles 2017blank page",
            "11": "11 0620/63/o/n/17 \u00a9 ucles 2017blank page",
            "12": "12 0620/63/o/n/17 \u00a9 ucles 2017blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        }
    },
    "2018": {
        "0620_m18_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 13 printed pages and 3 blank pages.  ib18 03_0620_12/3rp  \u00a9 ucles 2018 [turn over     *8565891309* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice (core)  february/march 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/12/f/m/18  1 four physical changes are listed.    1 condensation  2 evaporation  3 freezing  4 sublimation    in which changes do the particles move further apart?  a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      2 the diagram shows liquid in a burette and in a measuring cylinder.    100 90 8070605040302010 measuring cylinde r burette27 2829     which row shows the readings for the burette and the measuring cylinder?     burette measuring  cylinder  a 27.8 42  b 27.8 44  c 28.2 42  d 28.2 44     ",
            "3": "3  \u00a9 ucles 2018 0620/12/f/m/18 [turn over  3 substance l melts at \u20137  \u00b0c and is a brown liquid at room temperature.    which temperature is the boiling point of pure l?  a \u201377  \u00b0c  b \u20137  \u00b0c to +7  \u00b0c  c 59  \u00b0c  d 107  \u00b0c to 117  \u00b0c      4 a student is given a mixture of barium sulfate, copper( ii) sulfate and water.    the table shows information about barium sulfate and copper( ii) sulfate.    substance solubility in water state at room  temperature  barium sulfate insoluble solid  copper( ii) sulfate soluble solid    how does the student obtain copper( ii) sulfate crystals from the mixture?  a crystallisation followed by distillation  b crystallisation followed by filtration  c distillation followed by crystallisation  d filtration followed by crystallisation      5 what is the nucleon number of an atom?  a the number of electrons, neutrons and protons in the nucleus  b the number of neutrons and protons in the nucleus  c the number of neutrons in the nucleus  d the number of protons in the nucleus     6 caesium, cs, is an element in group i of the periodic table.    when caesium reacts it forms a positive ion, cs +.    how is a caesium ion formed?  a a caesium atom gains a proton.  b a caesium atom gains an electron.  c a caesium atom loses an electron.  d a caesium atom shares an electron. ",
            "4": "4  \u00a9 ucles 2018 0620/12/f/m/18  7 which statement about graphite and diamond is correct?  a diamond has a high melting point but graphite does not.  b graphite and diamond both conduct electricity.  c graphite and diamond both have giant structures.  d graphite is ionic and diamond is covalent.      8 what is the definition of relative atomic mass, ar?    average mass of naturally occurring atoms of an element mass of one atom of 12ca \u00d7  12 average mass of naturally occurring atoms of an element mass of one atom of 12c  \u00d7  12b average mass of naturally occurring atoms of an element mass of one atom of 12cc mass of one atom of 12c average mass of naturally occurring atoms of an elementd     9 which statement about electrolysis reactions is correct?  a when concentrated aqueous sodium chloride is electrolysed, sodium forms at the cathode.  b when concentrated hydrochloric acid is electrolysed, a green gas forms at the cathode.  c when dilute sulfuric acid is electrolysed, a colourless gas forms at both electrodes.  d when molten lead( ii) bromide is electrolysed, lead forms at the anode.    10 statement 1 hydrogen is used as a fuel.    statement 2 when hydrogen burns in the air to form water, heat energy is produced.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statem ent 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     ",
            "5": "5  \u00a9 ucles 2018 0620/12/f/m/18 [turn over  11 the diagram shows a match.        by striking the match, a chemical reaction takes place.    which row describes the chemical reaction?     type of reaction reason  a endothermic because energy is given out as the match burns  b endothermic because energy is used to strike the match  c exothermic because energy is given out as the match burns  d exothermic because energy is used to strike the match     12 magnesium carbonate was reacted with dilute hydrochloric acid in a conical flask.    the conical flask was placed on a balance and the mass of the conical flask and contents was recorded as the reaction proceeded.    during the reaction, carbon dioxide gas was produced.    the reaction was done at two different temperatures.    which row is correct?     change in mass temperature at which the  mass changed more quickly  a decrease higher temperature  b decrease lower temperature  c increase higher temperature  d increase lower temperature    ",
            "6": "6  \u00a9 ucles 2018 0620/12/f/m/18  13 separate samples of anhydrous copper( ii) sulfate and hydrated copper( ii) sulfate are heated.    heatanhydrous copper( ii) sulfate heathydrated copper( ii) sulfate     which row shows the correct colour changes?     anhydrous copper( ii) sulfate hydrated copper( ii) sulfate  a blue to white white to blue  b no change blue to white  c white to blue blue to white  d white to blue no change      14 in which equation does oxidation of the underlined substance occur?  a 2cuo   +  c  \u2192  co 2  +  2cu  b fe2o3  +  3co  \u2192  2fe  +  3co 2  c 2mg  +  o 2  \u2192  2mgo  d mno 2  +  4hc l  \u2192  mnc l 2  +  2h 2o  +  c l 2      15 which property is shown by the alkali sodium hydroxide?  a it has a ph less than ph 7.  b it produces a gas when it is warmed with ammonium chloride.  c it turns blue litmus red.  d it turns universal indicator green.     16 a solution of compound z gives a light blue precipitate with aqueous ammonia. the precipitate  dissolves in an excess of ammonia.    a flame test is done on compound z.    what is the colour of the flame?  a blue-green  b lilac  c red  d yellow    ",
            "7": "7  \u00a9 ucles 2018 0620/12/f/m/18 [turn over  17 carbon, copper, magnesium, sodium and sulfur can all form oxides.    how many of these elements form acidic oxides?  a 1 b 2 c 3 d 4     18 which method is used to make the salt copper( ii) sulfate?  a dilute acid  +  alkali  b dilute acid  +  carbonate  c dilute acid  +  metal  d dilute acid  +  non-metal oxide    19 the periodic table lists all the known elements.    elements are arranged in order of ...  1 ... number.    the melting points of group i elements ...  2 ... down the group.    the melting points of group vii elements ...  3 ... down the group.    which words correctly complete gaps 1, 2 and 3?     1 2 3  a nucleon decrease increase  b nucleon increase decrease  c proton decrease increase  d proton increase decrease      20 which statements about group i and group vii elements are correct?    1 in group i, lithium is more reactive than potassium.  2 in group vii, chlorine is more reactive than fluorine.     statement 1 statement 2  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     ",
            "8": "8  \u00a9 ucles 2018 0620/12/f/m/18  21 which statement describes transition elements?  a they have high densities and high melting points.  b they have high densities and low melting points.  c they have low densities and high melting points.  d they have low densities and low melting points.      22 which trend occurs across the period from sodium to argon?  a a change from metal to non-metal  b an increase in melting point  c a more violent reaction with water  d an increase in electrical conductivity      23 why is argon used in lamps?  a argon forms molecules when electricity is passed through it.  b argon is inert and so does not react with the hot filament.  c argon is less dense than air.  d argon produces light when it burns.      24 metals w, x, y and z are reacted with dilute hydrochloric acid.    the oxides of metals w, x, y and z are heated with carbon.    the results are shown.    reaction w x y z  metal + dilute hydrochloric acid fizzing   fizzing   violent  fizzing no  reaction  metal oxide + carbon + heat no  reaction metal  produced no  reaction metal  produced    what is the order of reactivity of the metals?     most  reactive  least  reactive  a y w x z  b y x w z  c z w x y  d z x w y   ",
            "9": "9  \u00a9 ucles 2018 0620/12/f/m/18 [turn over  25 iron is extracted from fe 2o3 by reduction with carbon.    aluminium is difficult to extract from a l 2o3. the process requires electrolysis.    starting with the most reactive, which order of reactivity is correct?  a al \u2192 c \u2192 fe  b al \u2192 fe \u2192 c  c fe \u2192 al \u2192 c  d fe \u2192 c \u2192 al     26 which two properties are physical properties of all pure metals?     property 1 property 2  a brittle poor conductor of heat  b good conductor of electricity malleable  c good conductor of heat low melting point  d malleable low density      27 which statement about the uses of aluminium, copper and iron is correct?  a aluminium is used for aircraft manufacture because it has a high density.  b aluminium is used for food containers because it is a good conductor of electricity.  c copper is used for cooking utensils because it is a good conductor of heat.  d stainless steel is used for car bodies because it corrodes easily.     28 the list gives four experiments done with calcium carbonate.    1 acid added  2 alkali added  3 heated strongly  4 water added    which experiments produced carbon dioxide?  a 1 and 2 b 1 and 3 c 2 and 3 d 2 and 4    ",
            "10": "10  \u00a9 ucles 2018 0620/12/f/m/18  29 water must be purified before it is suitable for use in the home.    which processes are used to remove solid impurities and to kill bacteria?     to remove  solid impurities to kill  bacteria  a chlorination chlorination  b chlorination filtration  c filtration chlorination  d filtration filtration      30 which gas is not present in clean air?  a argon  b carbon dioxide  c carbon monoxide  d water vapour     31 which pair of compounds would make an npk fertiliser?  a ammonium sulfate and potassium phosphate  b calcium hydroxide and ammonium nitrate  c calcium phosphate and potassium chloride  d potassium nitrate and ammonium sulfate     32 which pollutant gas is produced by the decomposition of vegetation?  a carbon monoxide  b methane  c nitrogen dioxide  d sulfur dioxide    ",
            "11": "11  \u00a9 ucles 2018 0620/12/f/m/18 [turn over  33 sulfur burns to make sulfur dioxide.    which row describes a source of sulfur and a use of sulfur dioxide?     source of sulfur use of sulfur dioxide  a the air food preservative  b the air water treatment  c underground deposits food preservative  d underground deposits water treatment     34 the diagram shows the ph values of the soil in two parts of a garden, x and y.    x ph 7.0y ph 5.5     lime is used to neutralise the soil in one part of the garden.    to which part of the garden should the lime be added and why?     part of the garden because lime is  a x acidic  b x basic  c y acidic  d y basic     35 which substance is not used as a fuel?  a ethanol  b hydrogen  c methane  d oxygen    36 which formula represents an alkene?  a ch 4 b c 2h4 c c 2h6 d c 2h5oh     ",
            "12": "12  \u00a9 ucles 2018 0620/12/f/m/18  37 three chemical reactions are shown.    1 catalytic addition of steam to ethene  2 combustion of ethanol  3 fermentation of glucose    in which of the reactions does the relative molecular mass of the carbon-containing compound  decrease?  a 1 and 2 b 1 only c 2 and 3 d 3 only    38 how is ethanol produced by fermentation?  a using anaerobic conditions at 30  \u00b0c  b using anaerobic conditions at 450  \u00b0c  c using steam at 30  \u00b0c  d using steam at 450  \u00b0c    39 a compound has the formula ch 3cooh.    what is not a property of this compound?  a it has a smell like vinegar.  b it reacts with acids to form salts.  c it reacts with magnesium to produce hydrogen.  d it turns blue litmus red.    40 which statement about polymers is correct?  a polymers are formed by breaking down monomers.  b polymers can be natural or synthetic.  c polymers contain atoms of only one element.  d polymers have a giant ionic structure.    ",
            "13": "13  \u00a9 ucles 2018 0620/12/f/m/18    blank page",
            "14": "14  \u00a9 ucles 2018 0620/12/f/m/18  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/12/f/m/18  blank page",
            "16": "16  \u00a9 ucles 2018 0620/12/f/m/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m18_qp_22.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib18 03_0620_22/3rp  \u00a9 ucles 2018 [turn over     *3036484056 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2 multiple choice (extended)  february/march 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.    ",
            "2": "2  \u00a9 ucles 2018 0620/22/f/m/18  1 hydrogen chloride gas, hc l, reacts with ammonia gas, nh 3, to form solid ammonium chloride.    the apparatus is set up as shown.    after a few minutes, solid ammonium chloride forms where the two gases meet.    solid ammonium chloride source of hydrogen chloride gassource ofammonia gas     the experiment is repeated using hydrogen bromide, hbr, in place of hydrogen chloride.    how far along the tube does the solid ammonium bromide form?    ab cd source ofhydrogen bromide gassource ofammonia gas       2 substance l melts at \u20137  \u00b0c and is a brown liquid at room temperature.    which temperature is the boiling point of pure l?  a \u201377  \u00b0c  b \u20137  \u00b0c to +7  \u00b0c  c 59  \u00b0c  d 107  \u00b0c to 117  \u00b0c     ",
            "3": "3  \u00a9 ucles 2018 0620/22/f/m/18 [turn over  3 chromatography is done on a mixture containing a drug. the drug has an rf value of 0.66.    the diagram is not drawn to scale.    which spot on the chromatogram represents the drug?    15 cm 0.66  cm9.9 cm12 cma b c dsolvent front baseline      4 caesium, cs, is an element in group i of the periodic table.    when caesium reacts it forms a positive ion, cs+.    how is a caesium ion formed?  a a caesium atom gains a proton.  b a caesium atom gains an electron.  c a caesium atom loses an electron.  d a caesium atom shares an electron.     5 the structure of copper is described as a lattice of positive ions in a \u2018sea of electrons\u2019.    which statements are correct?    1 copper has a high melting point because of the strong electrostatic attraction  between the positive ions and the \u2018sea of electrons\u2019.  2 copper is malleable because the layers of atoms in the lattice can slide over each  other.  3 copper atoms can be oxidised to form copper ions by losing electrons.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "4": "4  \u00a9 ucles 2018 0620/22/f/m/18  6 three statements about diamond, graphite and silicon( iv) oxide are listed.    1 diamond and graphite both have giant covalent structures.  2 in silicon( iv) oxide, silicon and oxygen atoms are joined together by covalent bonds  throughout the whole structure.  3 diamond and silicon( iv) oxide have similar structures.    which statements are correct?  a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     7 the concentration of a hydrochloric acid solution is 0.5  mol  / dm3.    how many moles of hydrochloric acid are present in 25  cm3 of this solution?  a 0.0125 b 0.0200 c 12.5 d 20.0      8 a sample of an iron oxide contains 50.4  g of iron and 21.6  g of oxygen.    what is the empirical formula of the iron oxide?  a feo b feo 3 c fe 2o3 d fe 3o2      9 a solution of copper( ii) sulfate can be electrolysed using copper electrodes or carbon electrodes.    which statements are correct?    1 using copper electrodes, oxygen gas forms at the anode.  2 using copper electrodes, copper atoms lose electrons at the anode.  3 using carbon electrodes, copper metal forms at the cathode.  4 using carbon electrodes, copper ions gain electrons at the cathode.    a 1 and 2 b 1 and 3 c 2, 3 and 4 d 4 only     ",
            "5": "5  \u00a9 ucles 2018 0620/22/f/m/18 [turn over  10 pairs of metals are connected together to make a simple cell, as shown.    v metal 2voltmeter electrolytemetal 1     the table shows the reading on the voltmeter when different metals are used.     metal 2  beryllium cerium cobalt manganese metal 1 beryllium 0.00  v +0.64  v \u20131.57  v \u20130.67  v  cerium  0.00  v \u20132.21  v \u20131.30  v  cobalt   0.00  v +0.90  v  manganese    0.00  v    if metal 2 is more reactive than metal 1, the voltage measured is positive.    the greater the difference in reactivity of the metals, the larger the reading on the voltmeter.    what is the order of reactivity?     most  reactive  least  reactive  a cerium beryllium cobalt manganese  b cerium beryllium manganese cobalt  c cobalt manganese beryllium cerium  d cobalt manganese cerium beryllium     ",
            "6": "6  \u00a9 ucles 2018 0620/22/f/m/18  11 the energy level diagram for the reaction between x 2 and y 2 to form xy gas is shown.    energy progress of reactionx2(g)  +  y2(g) 2xy(g)     which statement is correct?  a energy is released when x 2 and y 2 bonds are broken.  b energy is needed to form xy bonds.  c the energy change, \u2206h, for the reaction is negative.  d the reaction is endothermic.     12 methane burns in oxygen to form carbon dioxide and water.    ch 4  +  2o 2  \u2192  co 2  +  2h 2o    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013h +410  c=o +805  o\u2013h +460  o=o +496    what is the energy change for the reaction?  a \u2013818  kj / mol  b \u2013323  kj / mol  c +323  kj / mol  d +818  kj / mol    ",
            "7": "7  \u00a9 ucles 2018 0620/22/f/m/18 [turn over  13 methanol is made by reacting carbon monoxide with hydrogen. the reaction is reversible.    co(g)  +  2h 2(g)    ch 3oh(g)    the forward reaction is exothermic.    which combination of temperature and pressure gives the highest equilibrium yield of methanol?     temperature  / \u00b0c pressure  / atmospheres  a 200 10  b 200 200  c 600 10  d 600 200     14 the ionic equation for the reaction between zinc and aqueous copper ions is shown.    zn(s)  +  cu 2+(aq)  \u2192  zn2+(aq)  +  cu(s)    which statement about this reaction is correct?  a copper ions are oxidised and their oxidation state changes.  b copper ions are reduced because they lose electrons.  c zinc atoms are oxidised and their oxidation state changes.  d zinc atoms are reduced because they gain electrons.      15 in which reaction is the rate of reaction not affected by light?  a the conversion of carbon dioxide and water to glucose and oxygen in green plants  b the reaction of bromine with ethene  c the reaction of chlorine with methane  d the reduction of silver ions to silver     ",
            "8": "8  \u00a9 ucles 2018 0620/22/f/m/18  16 calcium carbonate reacts with dilute hydrochloric acid to form bubbles of carbon dioxide.    at a higher temperature, the same reaction is faster.    which row explains this observation?     collision rate number of molecules with  sufficient energy to react  a increases more  b increases the same  c stays the same more  d stays the same the same      17 ethanoic acid reacts with water to produce an acidic solution.    which row describes the roles of ethanoic acid and water in this reaction?     ethanoic acid water  a accepts a proton donates a proton  b accepts an electron donates an electron  c donates a proton accepts a proton  d donates an electron accepts an electron     18 a solution of compound z gives a light blue precipitate with aqueous ammonia. the precipitate  dissolves in an excess of ammonia.    a flame test is done on compound z.    what is the colour of the flame?  a blue-green  b lilac  c red  d yellow      19 carbon, copper, magnesium, sodium and sulfur can all form oxides.    how many of these elements form acidic oxides?  a 1 b 2 c 3 d 4    ",
            "9": "9  \u00a9 ucles 2018 0620/22/f/m/18 [turn over  20 which method is used to make the salt copper( ii) sulfate?  a dilute acid  +  alkali  b dilute acid  +  carbonate  c dilute acid  +  metal  d dilute acid  +  non-metal oxide     21 the periodic table lists all the known elements.    elements are arranged in order of ...  1 ... number.    the melting points of group i elements ...  2 ... down the group.    the melting points of group vii elements ...  3 ... down the group.    which words correctly complete gaps 1, 2 and 3?     1 2 3  a nucleon decrease increase  b nucleon increase decrease  c proton decrease increase  d proton increase decrease     22 metal x reacts with non-metal y to form an ionic compound with the formula x 2y.    which statements are correct?    1 x is in group i of the periodic table.  2 x is in group ii of the periodic table. 3 y is in group vi of the periodic table. 4 y is in group vii of the periodic table.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    ",
            "10": "10  \u00a9 ucles 2018 0620/22/f/m/18  23 which statements about group i and group vii elements are correct?    1 in group i, lithium is more reactive than potassium.  2 in group vii, chlorine is more reactive than fluorine.     statement 1 statement 2  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     24 which two properties are physical properties of all pure metals?     property 1 property 2  a brittle poor conductor of heat  b good conductor of electricity malleable  c good conductor of heat low melting point  d malleable low density     25 aluminium is extracted from aluminium oxide using electrolysis.    carbon dioxide is formed in this process.    which equation shows the formation of carbon dioxide during the extraction of aluminium from  aluminium oxide by electrolysis?  a a l  2(co 3)3  \u2192  a l 2o3  +  3co 2  b a l 2o3  +  3co  \u2192  2a l  +  3co 2  c c  +  o 2  \u2192  co 2  d c4+  +  2o2\u2013  \u2192  co 2    26 a sample of solid x was added to three different solutions to predict the position of x in the  reactivity series.     x(s)  +  feso 4(aq) \u2192  no reaction   x(s)  +  2hc l(aq) \u2192  xc l 2(aq)  +  h 2(g)   x(s)  +  zn(no 3)2(aq) \u2192  no reaction    which other solution would react with solid x?  a caso 4(aq) b cuso 4(aq) c mgso 4(aq) d na 2so 4(aq)   ",
            "11": "11  \u00a9 ucles 2018 0620/22/f/m/18 [turn over  27 which statement about the uses of aluminium, copper and iron is correct?  a aluminium is used for aircraft manufacture because it has a high density.  b aluminium is used for food containers because it is a good conductor of electricity.  c copper is used for cooking utensils because it is a good conductor of heat.  d stainless steel is used for car bodies because it corrodes easily.      28 air is a mixture of gases.    the melting and boiling points of some gases present in clean, dry air are shown.    in the fractional distillation of liquid air, which gas boils first?     gas melting point  / \u00b0c boiling point  / \u00b0c  a argon \u2013189 \u2013186  b krypton \u2013157 \u2013153  c nitrogen \u2013210 \u2013196  d oxygen \u2013219 \u2013183     29 water must be purified before it is suitable for use in the home.    which processes are used to remove solid impurities and to kill bacteria?     to remove  solid impurities to kill  bacteria  a chlorination chlorination  b chlorination filtration  c filtration chlorination  d filtration filtration     30 which processes do not produce carbon dioxide?    1 heating limestone  2 burning gasoline in car engines  3 photosynthesis  4 production of nylon    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     ",
            "12": "12  \u00a9 ucles 2018 0620/22/f/m/18  31 which pair of compounds would make an npk fertiliser?  a ammonium sulfate and potassium phosphate  b calcium hydroxide and ammonium nitrate  c calcium phosphate and potassium chloride  d potassium nitrate and ammonium sulfate      32 which pollutant gas is produced by the decomposition of vegetation?  a carbon monoxide  b methane  c nitrogen dioxide  d sulfur dioxide      33 the equation for the formation of sulfur trioxide from sulfur dioxide is shown.    2so 2(g)  +  o 2(g)    2so 3(g)    the forward reaction is exothermic.    which combination of pressure and temperature gives the highest equilibrium yield of sulfur trioxide?     pressure temperature  a high high  b high low  c low high  d low low     ",
            "13": "13  \u00a9 ucles 2018 0620/22/f/m/18 [turn over  34 the diagram shows the ph values of the soil in two parts of a garden, x and y.    x ph 7.0y ph 5.5     lime is used to neutralise the soil in one part of the garden.    to which part of the garden should the lime be added and why?     part of the garden because lime is  a x acidic  b x basic  c y acidic  d y basic     35 statement 1 hydrogen is used as a fuel.    statement 2 when hydrogen burns in the air to form water, heat energy is produced.    which is correct?  a both statements are correct and statement 2 explains statement 1.  b both statements are correct but statem ent 2 does not explain statement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     36 which row identifies compounds in the same homologous series?     chemical  properties functional  group  a different different  b different same  c similar different  d similar same     ",
            "14": "14  \u00a9 ucles 2018 0620/22/f/m/18  37 three chemical reactions are shown.    1 catalytic addition of steam to ethene  2 combustion of ethanol  3 fermentation of glucose    in which of the reactions does the relative molecular mass of the carbon-containing compound  decrease?  a 1 and 2 b 1 only c 2 and 3 d 3 only    38 how is ethanol produced by fermentation?  a using anaerobic conditions at 30  \u00b0c  b using anaerobic conditions at 450  \u00b0c  c using steam at 30  \u00b0c  d using steam at 450  \u00b0c     39 which substances react together to form ethyl propanoate?  a ethanoic acid and propanol  b ethanol and propene  c ethene and propanol  d propanoic acid and ethanol    40 the structure of a chlorofluorocarbon polymer is shown.    c hch3 c fcl c hch3 c fcl     which monomer is used to make this polymer?    c fch3 ch3ca hcl ch cb fcl c clch3 cc hf c clch3 cd fh      ",
            "15": "15    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/22/f/m/18  ",
            "16": "16  \u00a9 ucles 2018 0620/22/f/m/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m18_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32 paper 3  theory (core) february/march 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib18 03_0620_32/2rp\u00a9 ucles 2018 *6572782506* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/f/m/18 \u00a9 ucles 2018 1 (a)\t\tthe\tstructures\tof\tfive\tsubstances,\ta,\tb,\tc,\td\tand\te,\tare\tshown. na+br \u2013na+ na+br \u2013 na+na+br \u2013h br \u2013 na+br \u2013br \u2013 abc ch h cdo c clcl cli o eo o brh br \t\tanswer\tthe\tfollowing\tquestions\tusing\tonly\tthe\tsubstances\tin\tthe\tdiagram. \t\teach\tsubstance\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\tstate\twhich\tsubstance,\ta,\tb,\tc,\td or e:  (i)\t\tis\ta\tdiatomic\tmolecule\t \t ..   [1]  (ii)\t\tcontains\tbromide\tions\t \t ...   [1]  (iii)\t\tis\tan\telement\t\t     [1]  (iv)\t\tis\ta\tgas\twhich\tis\ta\tproduct\tof\trespiration \t\t..   [1]  (v)\t\tgives\ta\tyellow\tcolour\tin\ta\tflame\ttest.\t\t    [1]  (b)\t\tan\tisotope\tof\toxygen\tis\trepresented\tby\tthe\tsymbol\t shown. 17o8 \t\tdeduce\tthe\tnumber\tof\tprotons,\tneutrons\tand\telectrons\tin\tthis\tisotope\tof\toxygen. \t number\tof\tprotons\t \t. \t number\tof\tneutrons\t \t... \t number\tof\telectrons\t \t...  [3]  (c)\t\tdescribe\ta\ttest\tfor\toxygen.  test \t. \t result\t\t ..  [2] \t [total:\t10]",
            "3": "3 0620/32/f/m/18 \u00a9 ucles 2018 [turn over 2 (a)\t\tthe\ttable\tshows\tthe\tmass\tof\teach\ttype\tof\tion\tpresent\tin\ta\t100\t cm3\tsample\tof\tmilk. name\tof\tion formula\tof\tionmass\tof\tion\tpresent in\t100\tcm3\tmilk\t/\tmg calcium ca2+125 chloride cl \u2013120 mg2+12 phosphate po43\u201395 potassium k+140 sodium na+58 so42\u201330 negative\tions\tof\torganic\tacids 160  (i)\t\tcalculate\tthe\tmass\tof\tcalcium\tions\tpresent\tin\ta\t20\t cm3\tsample\tof\tthis\tmilk. \t mass\tof\tcalcium\tions\t=\t..\tmg\t\t[1]  (ii)\t\twhich\tpositive\tion\tis\tpresent\tin\tthe\thighest\tconcentration\tin\tthis\tsample\tof\tmilk?  \t ...   [1]  (iii)\t\tname\tthe\tcompound\tformed\tfrom\tmg2+\tand\tso42\u2013\tions.  \t ...   [1]  (iv)\t\tdescribe\ta\t test\tfor\tchloride\tions.  test \t ..  \t . \t result\t\t ...  [3]",
            "4": "4 0620/32/f/m/18 \u00a9 ucles 2018  (b)\t\tone\tof\tthe\torganic\tacids\tpresent\tin\tmilk\tis\tlactic\tacid. \t\tthe\tstructure\tof\tlactic\tacid\tis\tshown. cco oho hchh hh  (i)\t\ton\tthe\tstructure\tshown\tdraw\ta\tcircle\taround\tthe\tcarboxylic\tacid\tfunctional\tgroup.\t [1]  (ii)\t\tdeduce\tthe\tmolecular\t formula\tof\tlactic\tacid\tshowing\tthe\tnumber\tof\tcarbon,\thydrogen\t and\t oxygen\tatoms.  \t ...   [1]  (c)\t\tethanoic\tacid\tis\tanother\torganic\tacid.  (i)\t\tthe\treduction\tof\tethanoic\tacid\tproduces \tethanol. \t \twhat\tis\tmeant\tby\tthe\tterm\treduction ?  \t ...   [1]  (ii)\t\tthe\tmolecular\tformula\tof\tethanol\tis\tc2h6o. \t \tcomplete\tthe\ttable\tto\tcalculate\tthe\trelative\tmolecular\tmass\tof\tethanol. number\tof\tatoms relative\tatomic\tmass carbon 2 12 2 \u00d7\t12\t=\t24 hydrogen oxygen \t relative\tmolecular\tmass\t=\t..\t\t[2] \t [total:\t11]",
            "5": "5 0620/32/f/m/18 \u00a9 ucles 2018 [turn over 3\t\tthis\tquestion\tis\tabout\thalogens.  (a)\t\ta\tcrystal\tof\tiodine\twas\tplaced\tat\tthe\tbottom\tof\ta\tbeaker\tcontaining\tthe\tsolvent\tcyclohexane. \t\tafter\t2\tdays,\ta\tpurple\tcolour\thad\tspread\tthroughout\tthe\tcyclohexane. at the start after 2 hours after 2 dayscyclohexane crystal of iodine \t\texplain\tthese\tobservations\tusing\tthe\tkinetic\tparticle\tmodel.  \t  \t  \t  \t  \t..   [3] question 3 continues on the next page.",
            "6": "6 0620/32/f/m/18 \u00a9 ucles 2018  (b)\t\tthe\ttable\tshows\tthe\tproperties\tof\tsome\thalogens. halogenmelting\tpoint in\t\u00b0cboiling\tpoint in\t\u00b0cdensity\twhen liquid\tin\tg\t/\tcm3colour fluorine \u2013220 \u2013188 chlorine \u201329 1.56 light\tgreen bromine \u20137 59 3.12 red-brown iodine 114 184 3.96 grey-black  (i)\t\tcomplete\tthe\ttable\tto\testimate: \t \u25cf\t\tthe\tdensity\tof\tliquid\tfluorine \t \u25cf\t\tthe\tmelting\tpoint\tof\tchlorine.  [2]  (ii)\t\tis\tfluorine\tlighter\tor\tdarker\tin\tcolour\tthan \tchlorine? \t \texplain\tyour\tanswer.  \t .  \t ...   [1]  (iii)\t\twhat\tis\tthe\tphysical\tstate\tof\tbromine\tat\t 40\t\u00b0c? \t \tgive\ta\treason\tfor\tyour\tanswer.  \t .  \t ...   [2]  (c)\t\tcomplete\t the\tchemical\t equation\t for\tthe\treaction\tof\taqueous\t bromine\twith\taqueous\t potassium\tiodide. \t ..\t\t+\t\t2k i    i2\t\t+\t\t.kbr\t [2] \t [total:\t10]",
            "7": "7 0620/32/f/m/18 \u00a9 ucles 2018 [turn over 4\t\tthis\tquestion\tis\tabout\torganic\tcompounds.  (a)\t\twhich\ttwo\tstatements\tabout\tmembers\tof\ta\thomologous\tseries\tare\tcorrect? \t\ttick\ttwo\tboxes. \t they\thave\tsimilar\tchemical\tproperties. \t they\thave\tsimilar\tphysical\tproperties. \t they\thave\tthe\tsame\tfunctional\tgroup. \t they\thave\tthe\tsame\trelative\tmolecular\tmass. \t they\thave\tthe\tsame\tnumber\tof\tcarbon\tatoms.  [2]  (b)\t\tto\twhich\thomologous\tseries\tdo\tmethane\tand\tethane\tbelong?  \t..   [1]  (c)\t\tmethane\tand\tethane\tare\tboth\thydrocarbons. \t\twhat\tis\tmeant\tby\tthe\tterm\thydrocarbon ?  \t  \t..   [2]  (d)\t\tdraw\tthe\tstructure\tof\tethane\tshowing\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [1]",
            "8": "8 0620/32/f/m/18 \u00a9 ucles 2018  (e)\t\tthe\thydrocarbon\t tetradecane,\t c14h30,\tcan\tbe\tcracked\tto\tform\ta\tmixture\tof\talkanes\tand\talkenes.  (i)\t\tstate\ttwo\tconditions\tneeded\tfor\tcracking.  1 \t ..  2 \t ..  [2]  (ii)\t\tcomplete\t the\tchemical\t equation\tfor\tthe\tcracking\tof\ttetradecane\t to\tform\t two\tdifferent\t hydrocarbons.  c14h30    c3h6\t\t+\t\t\t [1]  (f)\t\tethanol\tcan\tbe\tmanufactured\tfrom\tethene. \t\tcomplete\tthe\tword\tequation\tfor\tthis\treaction. \t ethene\t\t+\t\t..\t\t \t\tethanol\t [1]  (g)\t\tethene\tcan\tbe\tpolymerised\tto\tform\tpoly(ethene). \t\tcomplete\tthe\tsentence\tabout\tthis\treaction\tusing\twords\tfrom\tthe\tlist. addition      condensation      ions      monomers      oxidation      polymers   ethene\t..\t combine\tto\tform\tpoly(ethene)\t by\t..\t polymerisation .  [2] \t [total:\t12]",
            "9": "9 0620/32/f/m/18 \u00a9 ucles 2018 [turn over 5\t\tthis\tquestion\tis\tabout\tmetals.  (a)\t\tmagnesium\tis\tmanufactured\tby\tthe\telectrolysis\tof\tmolten\tmagnesium\tchloride. unreactive gas inunreactive gas outanode (+) cathode (\u2013 ) molten magnesium molten magnesium chloride  (i)\t\twhat\tinformation\t in\tthe\tdiagram\tshows\tthat\tmolten\tmagnesium\t is\tless\tdense\tthan\tmolten\t magnesium\tchloride?  \t ...   [1]  (ii)\t\tone\tof\tthe\tproducts\tof\tthis\telectrolysis\tis \tmagnesium. \t \tstate\tthe\tname\tof\tthe\tother\tproduct.  \t ...   [1] \t\tan\tunreactive\tgas\tis\tblown\tover\tthe\tsurface\tof\tthe\tmolten\tmagnesium.  (iii)\t\tsuggest\twhy\tan\tunreactive\t gas\tand\t not\tair\tis\tblown\tover\tthe\tsurface\tof\tthe\tmolten\t magnesium.  \t ...   [1]  (iv)\t\tsuggest\tthe\tname\tof\tan\tunreactive\tgas\t which\tcould\tbe\tused.  \t ...   [1]",
            "10": "10 0620/32/f/m/18 \u00a9 ucles 2018  (b)\t\tthe\ttable\tshows\tsome\tproperties\tof\tfour\tmetals. metaldensity\tin g\t/\tcm3melting\tpoint in\t\u00b0crelative strengthrelative\telectrical\t conductivity aluminium 2.7 660 7 9 cobalt 8.9 1495 21 4 gallium 5.9 30 1 1 nickel 8.9 1455 20 3 \t\tanswer\tthese\tquestions\tusing\t only\tthe\tinformation\tshown\tin\tthe\ttable.  (i)\t\twhich\tmetal\tis\tmost\tsuitable\tto\tmake\tthe\tbody\tof\tan\taircraft? \t \tgive\ta\treason\tfor\tyour\tanswer.  \t .  \t ...   [2]  (ii)\t\twhich\tmetal\tis\tmost\tsuitable\tto\tuse\tfor\toverhead\tpower\tcables? \t \tgive\ta\treason\tfor\tyour\tanswer.  \t .  \t ...   [2]  (iii)\t\twhich\ttwo\tmetals\tin\tthe\ttable\tare\ttransition\telements? \t ... \tand\t\t   [1]  (c)\t\tgive\ttwo\tproperties\tof\ttransition\telements\twhich\tare\t not\tshown\tby\tgroup\ti\telements.  1 \t.  2 \t.  [2]  (d)\t\tcobalt\tis\tadded\tto\tiron\tto\tmake\tsteel\talloys.  (i)\t\twhat\tis\tmeant\tby\tthe\tterm\talloy ?  \t .  \t ...   [1]  (ii)\t\tgive\tone\treason\twhy\talloys\tare\tused\tinstead\tof\tpure\tmetals.  \t ...   [1] \t [total:\t13]",
            "11": "11 0620/32/f/m/18 \u00a9 ucles 2018 [turn over 6\t\tthis\tquestion\tis\tabout\tsulfur\tand\tits\tcompounds.  (a)\t natural\tgas\tcontains\thydrocarbons\tand\thydrogen\tsulfide.  (i)\t\tgive\tthe\tname\tof\tthe\thydrocarbon\t which\tis\tpresent\tin\tthe\tgreatest\tconcentration\t in\tnatural\t gas.  \t ...   [1]  (ii)\t\thydrogen\t sulfide\tis\tremoved\tfrom\tnatural\tgas\tby\treaction\twith\toxygen\tin\tthe\tpresence\t of\t a\tcatalyst. \t \twhat\tis\tthe\tpurpose\tof\ta\tcatalyst?  \t ...   [1]  (b) (i)\t\tname\tthe\tacid\tmanufactured\tfrom\tsulfur.  \t ...   [1]  (ii)\t\twhen\tfossil\tfuels\tcontaining\tsulfur\tare\tburned,\tsulfur\tdioxide\tis\tformed. \t \tsulfur\tdioxide\tcontributes\tto\tacid\train. \t \tgive\tone\tharmful\teffect\tof\tacid\train\ton\tbuildings.  \t ...   [1]  (iii)\t\tsulfur\tdioxide\tis\toxidised\tby\tnitrogen\tdioxide\tin\tthe\tatmosphere\tto\tform\tsulfur\ttrioxide. so2  +  no2    so3  +  no \t \thow\tdoes\tthis\tequation\tshow\tthat\tsulfur \tdioxide\tis\toxidised?  \t .  \t ...   [1] \t [total:\t5]",
            "12": "12 0620/32/f/m/18 \u00a9 ucles 2018 7\t\tacids\thave\tcharacteristic\tchemical\tproperties.  (a)\t\tdescribe\tthe\treactions\tof\thydrochloric\tacid\twith:  \u25cfcalcium\toxide  \u25cfmagnesium  \u25cfa\tnamed\tindicator\tof\tyour\tchoice.  \t  \t  \t  \t  \t  \t  \t..   [5]  (b)\t\tacids\treact\twith\talkalis\tsuch\tas\tsodium\thydroxide.  (i)\t\twhat\ttype\tof\tchemical\treaction\tis\tthis?  \t ...   [1]  (ii)\t\twhich\t one\tof\tthe\tfollowing\tph\tvalues\tis\tthe\tph\tof\tan\taqueous\tsolution\tof\tsodium\thydroxide? \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. ph\t2\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t5\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t7\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t13  [1]  (iii)\t\ta\tmixture\tof\tsodium\thydroxide\tand\tammonium\tsulfate\tis\twarmed\tgently. \t \tstate\tthe\tname\tof\tthe\tgas\tproduced.  \t ...   [1]",
            "13": "13 0620/32/f/m/18 \u00a9 ucles 2018 [turn over  (iv)\t\tthe\tmelting \tpoint\tof\tsodium\thydroxide\tis \t319\t\u00b0c. \t \tthe\tboiling\tpoint\tof\tsodium\thydroxide\tis \t1390\t\u00b0c. \t \twhich\tone\tof\tthe\tfollowing\tstatements\tabout\tsodium\thydroxide\t is\tcorrect? \t \ttick\tone\tbox. \t \tpure\tsodium\thydroxide\tmelts\tover\ta\trange\tof\ttemperatures. \t \timpure\tsodium\thydroxide\thas\ta\tsharp\tmelting\tpoint. \t \tpure\tsodium\thydroxide\tboils\tbetween\t319\t \u00b0c\tand\t1390\t \u00b0c. \t \tpure\tsodium\thydroxide\thas\ta\tsharp\tboiling\tpoint.  [1]  (v)\t\tsodium\thydroxide\tis\tused\tin\tthe\tmanufacture\tof\tsome\tmedicines. \t \twhy\tis\tit\timportant\tthat\tthe\tingredients\tused\tin\tmedicines\tare\tpure?  \t ...   [1] \t [total:\t10]",
            "14": "14 0620/32/f/m/18 \u00a9 ucles 2018 8\t\tthis\tquestion\tis\tabout\tiron\tand\tits\tcompounds.  (a)\t\ta\tstudent\tinvestigates\t the\trate\tof\treaction\tof\t1\tg\tof\tiron\tpowder\twith\t25\tcm3\tof\thydrochloric\t acid\t of\tconcentration\t2.0\t mol\t/\tdm3.\tthe\ttemperature\tis\t20\t \u00b0c. \t\twhat\teffect\tdo\tthe\tfollowing\thave\ton\tthe\tinitial\trate\tof\tthis\treaction?  (i)\t\tusing\thydrochloric\tacid\tof\tconcentration \t1.2\tmol\t/\tdm3. \t \tall\tother\tconditions\tare\tkept\tthe\tsame.  \t ...   [1]  (ii)\t\tusing\ta\tpiece\tof\tiron\tof\tmass\t1\t g. \t \tall\tother\tconditions\tare\tkept\tthe\tsame.  \t ...   [1]  (iii)\t\tcarrying\tout\tthe\texperiment\tat\t25\t \u00b0c. \t \tall\tother\tconditions\tare\tkept\tthe\tsame.  \t ...   [1]  (b)\t\tsiderite\tis\tan\tore\tof\tiron.  (i)\t\tstate\tthe\tname\tof\tone\tother\tore\tof\tiron.  \t ...   [1]  (ii)\t\tsiderite\tcontains\tmainly\tiron( ii)\tcarbonate. \t \tdescribe\thow\tto\tshow\tthat\tsiderite\tcontains\ta\tcarbonate.  \t .  \t .  \t ...   [3]",
            "15": "15 0620/32/f/m/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (c)\t\tiron\tcan\tbe\textracted\tfrom\tits\toxide\tby\treduction\twith\tcarbon. \t\tthe\ttable\tshows\thow\teasy\tit\tis\tto\treduce\tfour\tmetal\toxides\tby\theating\twith\tcarbon. metal\toxide ease\tof\treduction\twith\tcarbon bismuth( iii)\toxide only\treduced\tabove\t250\t \u00b0c iron(iii)\toxide only\treduced\tabove\t650\t \u00b0c tin(ii)\toxide only\treduced\tabove\t500\t \u00b0c titanium( iv)\toxide not\treduced\tat\t700\t \u00b0c \t\tuse\tthis\tinformation\t to\tput\tthe\tmetals\tin\torder\tof\ttheir\treactivity.\t put\tthe\tleast\treactive\tmetal\t first. least reactive most reactive  [2] \t [total:\t9]",
            "16": "16 0620/32/f/m/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_m18_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/42 paper 4  theory (extended) february/march 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib18 03_0620_42/3rp\u00a9 ucles 2018 *2199140551* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/f/m/18 \u00a9 ucles 2018 1  this question is about gases.  (a)  the following substances are gases at room temperature. letter a b c d e f g h substance so2 ar co cl 2 nh3 co2 ch4 c3h8   identify, by letter:  (i)  a gas which combines with water to form acid rain  ..   [1]  (ii)  two gases which exist as diatomic molecules  ..   [2]  (iii)  a gas which bleaches damp litmus paper  .   [1]  (iv)  a gas which is used as an inert atmosphere in lamps  ..   [1]  (v)  two gases which are found in clean dry air  ..   [2]  (vi)  two gases which are found in refinery gas.  ..   [2]  (b)  nf3 has covalent bonds.  (i)  what is a covalent bond?   .   ...   [2]  (ii)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  nf3.   show outer shell electrons only. n ff f  [3]",
            "3": "3 0620/42/f/m/18 \u00a9 ucles 2018 [turn over  (c)  air is a mixture. nitrogen and oxygen are the two most common gases in air.  (i)  what is meant by the term mixture?   .   ...   [1]  (ii)  state the percentage of oxygen, to the nearest whole number, in clean dry air.   ...   [1]  (iii)  describe the steps in the industrial process which enables nitrogen and oxygen to be  separated from clean dry air.   use scientific terms in your answer.   .   .   .   .   .   .   ...   [3]  (iv)  which physical property of nitrogen and oxygen allows them to be separated?   ...   [1]  [total: 20]",
            "4": "4 0620/42/f/m/18 \u00a9 ucles 2018 2  sodium chloride is a typical ionic compound.  (a)  the diagram shows part of a lattice of sodium chloride.  (i)  complete the diagram to show the ions present. use \u2018+\u2019 for na+ ions and \u2018\u2013\u2019 for cl \u2013 ions.  one ion has been completed for you. +  [2]  (ii)  how many electrons does a chloride ion have?   ...   [1]  (iii)  identify an element which has atoms with the same number of electrons as a sodium ion.   ...   [1]  (b)  electrolysis of concentrated aqueous sodium chloride is an important industrial process.  (i)  what is meant by the term electrolysis ?   .   ...   [2]  (ii)  name the products of the electrolysis of concentrated aqueous sodium chloride.  1  ..  2  ..  3  ..  [3] (iii)  write an ionic half-equation for the reaction at the cathode.   include state symbols.   ...   [2]",
            "5": "5 0620/42/f/m/18 \u00a9 ucles 2018 [turn over  (c)  silver chloride can be made by reacting aqueous sodium chloride with aqueous silver nitrate.  the other product of the reaction is sodium nitrate. the chemical equation for the reaction is  shown. nacl (aq)  +  agno3(aq)    agcl (s)  +  nano3(aq)   a student attempted to make the maximum amount of sodium nitrate crystals. the process  involved three steps.  step 1  the student added aqueous sodium chloride to aqueous silver nitrate and stirred.  neither reagent was in excess.  step 2  the student filtered the mixture. the student then washed the residue and added the washings to the filtrate.  step 3  the student obtained sodium nitrate crystals from the filtrate.  (i)  describe what the student observed in step 1.   ...   [1]  (ii)  why was the residue washed in step 2?   .   ...   [1]  (iii)  give the names of the two processes which occurred in step 3.  1  ..  2  ..  [2]  (iv)  the student started with 20 cm 3 of 0.20 mol / dm3 nacl (aq).  \u25cf determine the amount of nac l (aq) used.  amount of nac l (aq) used = .. mol   the yield of nano3 crystals was 90%.  \u25cf calculate the mass of nano3 crystals made.  mass of nano3 crystals = .. g  [4]  (v)  write a chemical equation for the action of heat on sodium nitrate crystals.   ...   [2]  [total: 21]",
            "6": "6 0620/42/f/m/18 \u00a9 ucles 2018 3  limestone rock is mainly calcium carbonate, caco3.  (a)  the \u2018limestone cycle\u2019 is shown. each step is numbered. limestone calcium carbonate caco3(s) limewater calcium hydroxide ca(oh)2(aq)slaked lime calcium hydroxide ca(oh)2(s)lime ... ... step 2 add limited waterstep 4 add co2 step 3 add an excess of waterstep 1 heat  (i)  complete the box to give the chemical name and formula of lime. [2]  (ii)  which step involves a physical change?   ...   [1]  (iii)  what type of reaction is step 1?   ...   [1]  (iv)  suggest how step 2 could be reversed.   ...   [1]  (v)  write a chemical equation for step 4.   ...   [1]  (vi)  explain why step 4 is a neutralisation reaction. refer to the substances reacting in your  answer.   .   ...   [2]  (b)  dolomite is a similar rock to limestone. dolomite contains magnesium carbonate, mgco3.   write a chemical equation for the reaction between magnesium carbonate and dilute nitric acid.   ..   [2]",
            "7": "7 0620/42/f/m/18 \u00a9 ucles 2018 [turn over  (c)  forsterite is another rock which contains a magnesium compound.   a sample of forsterite has the following composition by mass: mg, 2.73 g; si, 1.58 g; o, 3.60 g.   calculate the empirical formula of forsterite.  empirical formula = ..  [2]  [total: 12]",
            "8": "8 0620/42/f/m/18 \u00a9 ucles 2018 4  ammonia is an important chemical.  (a)  ammonia is a base.  (i)  in chemistry, what is meant by the term base?   .   ...   [1]  (ii)  write a word equation to show ammonia behaving as a base.   .   ...   [2]  (b)  ammonia reacts with chlorine. the chemical equation is shown. 2nh3(g)  +  3cl 2(g)    n2(g)  +  6hcl (g)  (i)  calculate the volume of chlorine, measured at room temperature and pressure, needed to  react completely with 0.68 g of ammonia.  volume of chlorine = .. cm3  [3]",
            "9": "9 0620/42/f/m/18 \u00a9 ucles 2018 [turn over  (ii)  the chemical equation can be represented as shown. 2h hh++36cl cl nn n cl h   use the bond energies in the table to determine the energy change, \u03b4h, for the reaction  between ammonia and chlorine. bondbond energy in kj / mol n\u2013h 390 cl \u2013cl 240 n\u2261n 945 h\u2013cl 430  \u25cf energy needed to break bonds  .. kj  \u25cf energy released when bonds are formed  .. kj  \u25cf energy change, \u03b4h, for the reaction between ammonia and chlorine  .. kj  [3]  (iii)  is the reaction endothermic or exothermic? explain your answer.   .   ...   [1]",
            "10": "10 0620/42/f/m/18 \u00a9 ucles 2018  (c)  ammonia reacts with oxygen at high temperatures in the presence of a suitable catalyst to  form nitric oxide, no. 4nh3(g)  +  5o2(g)    4no(g)  +  6h2o(g)  (i)  explain how this chemical equation shows ammonia acting as a reducing agent.   .   ...   [1]  (ii)  suggest a suitable catalyst for the reaction from the list of metals. give a reason for your  answer. aluminium        calcium        platinum        potassium        sodium  suitable catalyst  ..  reason  .  [2]  [total: 13]",
            "11": "11 0620/42/f/m/18 \u00a9 ucles 2018 [turn over 5  alcohols are a \u2018family\u2019 of organic molecules which have the same general formula.  (a)  what is the name given to any \u2018family\u2019 of organic molecules which have the same general  formula and similar chemical properties?   ..   [1]  (b)  give the general formula of alcohols.   ..   [1]  (c)  propan-1-ol can be made from propene.  (i)  name the reagent and give the conditions needed to convert propene into propan-1-ol.  reagent  ...  conditions  ...  [2]  (ii)  write a chemical equation for the complete combustion of propan-1-ol.   ...   [2]  (d)  a simple sugar can be represented as shown. o o h h   simple sugars can be polymerised to make more complex carbohydrates.  (i)  complete the diagram to show part of a carbohydrate polymer made from the simple  sugar shown.  [2] (ii)  name the chemical process which occurs when a carbohydrate polymer is broken down  into simple sugars.   ...   [1]  (iii)  what conditions are needed for this process to occur?   ...   [1]",
            "12": "12 0620/42/f/m/18 \u00a9 ucles 2018  (e)  chromatography can be used to identify simple sugars in a mixture.   a student analysed a mixture of simple sugars by chromatography. all the simple sugars in the  mixture were colourless.  (i)  what is the name given to the type of substance used to identify the positions of the simple  sugars on the chromatogram?   ...   [1]  (ii)  the student calculated the rf value of a spot on the chromatogram.   complete the expression for the rf value of the spot.  rf =  [1]  (iii)  how could a student identify a simple sugar from its rf value?   .   ...   [1]  (iv)  sometimes not all the substances in a mixture can be identified from the chromatogram  produced.   explain why this may happen.   ...   [1]  [total: 14]",
            "13": "13 0620/42/f/m/18 \u00a9 ucles 2018blank page",
            "14": "14 0620/42/f/m/18 \u00a9 ucles 2018blank page",
            "15": "15 0620/42/f/m/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "16": "16 0620/42/f/m/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_m18_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52 paper 5  practical test february/march 2018  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib18 03_0620_52/3rp\u00a9 ucles 2018 *7059295991* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/52/f/m/18 \u00a9 ucles 2018 1  you are going to investigate the reaction between dilute hydrochloric acid and an aqueous solution  of sodium carbonate labelled solution l.   read all the instructions carefully before starting the experiments.   instructions   you are going to do three experiments.  (a) experiment 1 \t \u25cf\t \tuse\tthe\tmeasuring\tcylinder\tto\tpour\t25\t cm3 of solution l into the conical flask. \t \u25cf\t \tadd\tten\tdrops\tof\tthymolphthalein\tindicator\tto\tthe\tconical\tflask. \t \u25cf\t \tfill\tthe\tburette\tup\tto\tthe\t0.0\t cm3 mark with the dilute hydrochloric acid. \t \u25cf\t \tadd\tdilute\thydrochloric\t acid\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\t1.0\tcm3\tat\ta\ttime,\twhile\t swirling\tthe\tconical\tflask,\tuntil\tthe\tsolution\tjust\tchanges\tto\tcolourless. \t \u25cf\t \trecord\tthe\tburette\treadings\tin\tthe\ttable \tand\tcomplete\tthe\ttable.   keep your solution from experiment 1 to use in experiment 2. experiment\t1 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 \t [2]  (b) experiment 2 \t \u25cf\t \tnow\tadd\tten\tdrops\tof\tmethyl\torange\tindicator\tto\tthe\tsolution\tin\tthe\tconical\tflask\tfrom\t experiment\t1. \t \u25cf\t \trecord\tthe\tinitial\tburette\treading\tin\tthe\ttable. \t \u25cf\t \tadd\tdilute\thydrochloric\t acid\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\t1.0\tcm3\tat\ta\ttime,\twhile\t swirling\tthe\tconical\tflask,\tuntil\tthe\tsolution\tjust\tchanges\tcolour. \t \u25cf\t \trecord\tthe\tfinal\tburette\treading\tin\tthe\ttable\tand\tcomplete\tthe\ttable. experiment\t2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 [2]",
            "3": "3 0620/52/f/m/18 \u00a9 ucles 2018 [turn over  (c) experiment 3 \t \u25cf\t \tempty\tthe\tconical\tflask\tand\trinse\tit\twith\t distilled\twater. \t \u25cf\t \trepeat\texperiment\t 1,\tusing\tmethyl\torange\tindicator\tinstead\tof\tthymolphthalein\t indicator\t and adding dilute hydrochloric acid from the burette to the conical flask until the solution  just\tchanges\tcolour. \t \u25cf\t \trecord\tthe\tburette\treadings\tin\tthe\ttable \tand\tcomplete\tthe\ttable. experiment 3 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 [1]  (d) (i)\t\twhat\tcolour\tchange\twas\tobserved\tin\tthe\tconical\tflask\tin\texperiment\t3?  from . to  .. \t [1]  (ii)\t\tapart\tfrom\tthe\tcolour\tchange,\twhat\twas \tobserved\tin\tthe\tconical\tflask\tin\texperiment\t3?   ... \t\t[1]  (e)  complete the sentence.   experiment .. needed the largest volume of dilute hydrochloric acid to change the colour  of\tthe\tindicator.\t [1]  (f)  give the name of a more accurate piece of apparatus for measuring the volume of solution l.   .. \t\t[1]  (g)  what would be the effect on the results if solution  l were warmed before adding the dilute  hydrochloric\tacid?\tgive\ta\treason\tfor\tyour\tanswer.  effect on the results  ...  reason   [2]",
            "4": "4 0620/52/f/m/18 \u00a9 ucles 2018  (h) (i)  determine the simplest whole number ratio of volumes of dilute hydrochloric acid used in  experiments\t1\tand\t3.   ... \t\t[1]  (ii)\t\tsuggest\twhy\tthe\tvolumes\tof\tdilute\thydrochloric\t acid\tused\tin\texperiments\t 1\tand\t3\tare\t different.   ... \t\t[1]  (i)\t\tsuggest\twhy\tuniversal\tindicator\t cannot be used in these experiments.      .. \t\t[1]  (j)  suggest how the reliability of the results could be checked.      .. \t\t[2] [total:16]",
            "5": "5 0620/52/f/m/18 \u00a9 ucles 2018 [turn over 2\t\tyou\tare\tprovided\twith\ttwo\tsubstances,\tsolution\t m and solid n. \t\tdo\tthe\tfollowing\ttests\ton\tthe\tsubstances,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.   tests on solution m   divide solution m\tinto\tfive\tapproximately\tequal\tportions\tin\tfive\ttest-tubes.  (a) (i)  describe the appearance of solution m.   ... \t\t[1]  (ii)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tm. \t ph\t=\t..\t\t[1]  (b)\t\tadd\ta\tfew\tdrops\tof\tdilute\tnitric\tacid\tand\tabout\t1\tcm3 of aqueous silver nitrate to the second  portion of solution m. \t\trecord\tyour\tobservations.   .. \t\t[1]  (c)\t\tadd\ta\tfew\tdrops\tof\tdilute\tnitric\tacid\tand\tabout\t1\tcm3 of aqueous barium nitrate to the third  portion of solution m. \t\trecord\tyour\tobservations.   .. \t\t[1]  (d)  add\tan\texcess\tof\taqueous\tsodium\thydroxide\tto\tthe\tfourth\tportion\tof\tsolution\t m. \t\trecord\tyour\tobservations.   .. \t\t[2]   keep the fifth portion of solution m for the test on solid n in (i).  (e)\t\tidentify\tsolution\t m.   .. \t\t[3]",
            "6": "6 0620/52/f/m/18 \u00a9 ucles 2018   tests on solid n   divide solid n\tinto\tthree\tapproximately\t equal\tportions\tin\tone\thard\tglass\ttest-tube\tand\ttwo\ttest-tubes.  (f)  describe the appearance of solid n.   .. \t\t[1]  (g)\t\theat\tthe\tfirst\tportion\tof\tsolid\t n\tin\tthe\thard\tglass\ttest-tube.\t heat\tgently\tand\tthen\tmore\tstrongly.   test the gas produced. \t\trecord\tyour\tobservations.            .. \t\t[4]  (h)\t\tadd\tabout\t1\t cm3 of dilute hydrochloric acid to the second portion of solid n\tin\ta\ttest-tube. \t\tcarry\tout\ta\tflame\ttest\ton\tthe\tmixture. \t\trecord\tthe\tcolour\tof\tthe\tflame.   .. \t\t[1]  (i)\t\tadd\tthe\tfifth\tportion\tof\tsolution\t m to the third portion of solid n\tin\ta\ttest-tube.\t leave\tthe\tsolution\t to\tstand\tfor\tabout\t5\tminutes. \t\trecord\tyour\tobservations.   .. \t\t[1]  (j)  what conclusions can you draw about solid n?      .. \t\t[2] [total:18]",
            "7": "7 0620/52/f/m/18 \u00a9 ucles 2018 [turn over 3  magnesium reacts with dilute sulfuric acid at room temperature to form hydrogen gas. \t\tplan\tan\texperiment\t to\tfind\tthe\trate\tof\treaction\tbetween\tmagnesium\t ribbon\tand\tdilute\tsulfuric\tacid. \t\tin\tyour\tanswer: \t \u25cf\t\tinclude\ta\tdiagram \t \u25cf\t\tindicate\thow\tyou\tcould\tuse\tthe\tresults\tobtained\tto\tfind\tthe\trate\tof\treaction. \t\tyou\tare\tprovided\twith\tcommon\tlaboratory\tapparatus,\tmagnesium\tribbon\tand\tdilute\tsulfuric\tacid.   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6] [total:\t6]",
            "8": "8 0620/52/f/m/18 \u00a9 ucles 2018blank page",
            "9": "9 0620/52/f/m/18 \u00a9 ucles 2018blank page",
            "10": "10 0620/52/f/m/18 \u00a9 ucles 2018blank page",
            "11": "11 0620/52/f/m/18 \u00a9 ucles 2018notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium  manganate( vii) from purple to  colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/52/f/m/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_m18_qp_62.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib18 03_0620_62/3rp \u00a9 ucles 2018 *5434778494* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62 paper 6  alternative to practical february/march 2018  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/f/m/18 \u00a9 ucles 2018 1  a student used paper chromatography to separate a mixture of coloured dyes. the diagram shows  the apparatus used. baselin emixture of coloured dyespaperrodclips  (a) (i)  draw a line on the diagram to show the level of the solvent. [1]  (ii) suggest a suitable solvent that could be used.   ...   [1]  (b)  what could be used to put the mixture of coloured dyes onto the paper?   ..   [1]  (c)  the clips hold the paper in position.   why is this important for the chromatography experiment?   ..   [1]",
            "3": "3 0620/62/f/m/18 \u00a9 ucles 2018 [turn over   the diagram shows the chromatogram obtained from four dyes, a, b, c and d. baselinesolvent fron t dcba  (d)  give one conclusion that can be drawn about dye b.   ..   [1]  (e)  suggest why dye c remained on the baseline.      ..   [1]  (f)  rf values are used to identify compounds. rf =distance travelled by the compound distance travelled by the solvent   calculate the rf value of dye a.  rf = ..  [2]  [total: 8]",
            "4": "4 0620/62/f/m/18 \u00a9 ucles 2018 2  a student investigated the reaction between dilute hydrochloric acid and an aqueous solution of  sodium carbonate labelled solution l.   three experiments were done.   experiment 1 \t \u25cf\t \ta\tmeasuring\tcylinder\twas\tused\tto\tpour\t25\t cm3 of solution l\tinto\ta\tconical\tflask. \t \u25cf\t \tten\tdrops\tof\tthymolphthalein\tindicator\twere\tadded\tto\tthe\tconical\tflask. \t \u25cf\t \ta\tburette\twas\tfilled\tup\tto\tthe\t0.0\t cm3\tmark\twith\tdilute\thydrochloric\tacid. \t \u25cf\t \tdilute\thydrochloric\t acid\twas\tadded\tfrom\tthe\tburette\tto\tthe\tconical\tflask\tuntil\tthe\tsolution\t just\t changed to colourless at the end-point of the titration.  (a)\t\tuse\tthe\tburette\tdiagram\t to\trecord\tthe\tfinal\tburette\treading\tin\tthe\ttable\tand\tcomplete\t the\ttable. 11 1213 final burette readin g experiment 1 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm30.0 difference\t /\tcm3  [1]",
            "5": "5 0620/62/f/m/18 \u00a9 ucles 2018 [turn over   experiment 2 \t \u25cf\t \tten\tdrops\tof\tmethyl\torange\tindicator\t were\tadded\tto\tthe\tsolution\t in\tthe\tconical\tflask\tfrom\t experiment 1. \t \u25cf\t \tdilute\thydrochloric\t acid\twas\tadded\tfrom\tthe\tburette\tto\tthe\tconical\tflask\tuntil\tthe\tsolution\t just\t changed colour.  (b)\t\tuse\tthe\tburette\tdiagram\t to\trecord\tthe\tfinal\tburette\treading\tin\tthe\ttable\tand\tcomplete\t the\ttable. 22 23 24 final burette readin g experiment 2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm312.0 difference\t /\tcm3 [1]   experiment 3 \t \u25cf\t the\tconical\tflask\twas\temptied\tand\trinsed\twith\tdistilled\twater. \t \u25cf\t \texperiment\t 1\twas\trepeated\t using\tmethyl\torange\tindicator\t instead\tof\tthymolphthalein\t indicator\t and\tadding\tdilute\thydrochloric\t acid\tfrom\tthe\tburette\tto\tthe\tconical\tflask\tuntil\tthe\tsolution\t just\t changed colour.  (c)  use the burette diagrams to record the burette readings in the table and complete the table. 23 2425 final burette readin g120 initial burette readin g experiment 3 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 difference\t /\tcm3 [3]",
            "6": "6 0620/62/f/m/18 \u00a9 ucles 2018  (d)\t\twhat\tcolour\tchange\twas\tobserved\tin\tthe\tconical\tflask\tin\texperiment\t3?  from ... to  ...  [1]  (e)\t\twhy\twas\tthe\tconical\tflask\temptied\t and\trinsed\twith\tdistilled\twater\tat\tthe\tstart\tof\texperiment\t 3?   ..   [1]  (f)  complete the sentence.   experiment .. needed the largest volume of dilute hydrochloric acid to change the colour  of the indicator. [1]  (g)  give the name of a more accurate piece of apparatus for measuring the volume of solution l.   ..   [1]  (h)  what would be the effect on the results if solution l were warmed before adding the   dilute hydrochloric acid? give a reason for your answer.  effect on the results  ...  reason   [2]  (i) (i)  determine the simplest whole number ratio of volumes of dilute hydrochloric acid used in  experiments 1 and 3.   ...   [1]  (ii)  suggest why the volumes of dilute hydrochloric acid used in experiments 1 and 3 are different.   ...   [1]  (j)  suggest why universal indicator cannot be used in these experiments.      ..   [1]  (k)\t\tsuggest\thow\tthe\treliability\tof\tthe\tresults\tcould\tbe\tchecked.      ..   [2] [total: 16]",
            "7": "7 0620/62/f/m/18 \u00a9 ucles 2018 [turn over 3  two substances, solution m and solid n, were analysed. solution m was aqueous iron( iii) chloride.   tests were done on the substances.   complete the expected observations.  tests on solution m  (a)  describe the appearance of solution m.   ..   [1]   solution m was divided into three equal portions in three test-tubes.  (b)\t\tdilute\tnitric\tacid\tand\taqueous\tsilver\tnitrate\twere\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t m.  observations     [2]  (c)  dilute nitric acid and aqueous barium nitrate were added to the second portion of solution m.  observations     [1]  (d) (i)  drops of aqueous sodium hydroxide were added to the third portion of solution m until a  change was seen.  observations  .   [2]  (ii)  an excess of aqueous sodium hydroxide was then added to the mixture.  observations  .   [1]",
            "8": "8 0620/62/f/m/18 \u00a9 ucles 2018   tests on solid n   some of the tests and observations are shown. tests on solid n observations the appearance of solid n was studied. green powder test 1 solid n was heated. the gas produced was tested.solid\tturned\tblack limewater\tturned\tmilky test 2 a\tflame\ttest\twas\tdone\ton\tsolid\t n. blue-green colour  (e)  name the gas produced in test 1.   ..   [1]  (f)  identify solid n.   ..   [2] [total:\t10]",
            "9": "9 0620/62/f/m/18 \u00a9 ucles 2018 [turn over 4  magnesium reacts with dilute sulfuric acid at room temperature to form hydrogen gas. \t\tplan\tan\texperiment\t to\tfind\tthe\trate\tof\treaction\t between\t magnesium\t ribbon\tand\tdilute\tsulfuric\tacid.   in your answer: \t \u25cf\t \tinclude\ta\tdiagram \t \u25cf\t \tindicate\thow\tyou\tcould\tuse\tthe\tresults\tobtained\tto\tfind\tthe\trate\tof\treaction.   you are provided with common laboratory apparatus, magnesium ribbon and dilute sulfuric acid.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "10": "10 0620/62/f/m/18 \u00a9 ucles 2018blank page",
            "11": "11 0620/62/f/m/18 \u00a9 ucles 2018blank page",
            "12": "12 0620/62/f/m/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        },
        "0620_s18_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 14 printed pages and 2 blank pages.  ib18 06_0620_11/3rp  \u00a9 ucles 2018 [turn over     *9563332168* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1 multiple choice (core)  may/june 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/11/m/j/18  1 the diagrams show particles in a container.    1 2 3     which two diagrams show the process of evaporation?  a 1 \u2192 2 b 1 \u2192 3 c 2 \u2192 3 d 3 \u2192 1     2 which piece of apparatus is used to measure exactly 26.3  cm3 of a liquid?    abcd      3 the melting points and boiling points of pure substances w, x and y are shown.     w x y  melting point  / \u00b0c \u2013114 115 \u2013101  boiling point  / \u00b0c 78 445 \u201334    the substances are chlorine, ethanol and sulfur.    which row identifies w, x and y?     w x y  a chlorine ethanol sulfur  b ethanol sulfur chlorine  c sulfur chlorine ethanol  d sulfur ethanol chlorine     ",
            "3": "3  \u00a9 ucles 2018 0620/11/m/j/18 [turn over  4 in which atom is the number of protons equal to the number of neutrons?  a 40ar b 19f c 23na d 16o    5 which row identifies an alloy, a pure metal and a non-metal?     alloy pure metal non-metal  a brass carbon copper  b brass copper carbon  c copper brass carbon  d copper carbon brass     6 a covalent molecule q contains exactly six shared electrons.    what is q?  a ammonia, nh 3  b chlorine, c l 2  c methane, ch 4  d water, h 2o    7 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     when the percentage of graphite is increased, the pencil slides across the paper more easily.    which statement explains this observation?  a graphite has a high melting point.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.    ",
            "4": "4  \u00a9 ucles 2018 0620/11/m/j/18  8 the equation for the reaction between magnesium and dilute sulfuric acid is shown.    the mr of mgso 4 is 120.    mg  +  h 2so 4  \u2192  mgso 4  +  h 2    which mass of magnesium sulfate is formed when 12  g of magnesium completely reacts with  dilute sulfuric acid?  a 5  g b 10  g c 60  g d 120  g      9 what is observed at each electrode when molten lead( ii) bromide is electrolysed using platinum  electrodes?     negative electrode positive electrode  a bubbles of a colourless gas bubbles of a brown gas  b bubbles of a colourless gas bubbles of a colourless gas  c shiny grey liquid bubbles of a brown gas  d shiny grey liquid bubbles of a colourless gas     10 which gas is used as a fuel?  a argon  b hydrogen  c nitrogen  d oxygen     11 burning fuels is an exothermic reaction.    what is meant by the term exothermic ?  a a gas is produced.  b energy is released.  c heat is absorbed.  d the mass of the fuel decreases.     ",
            "5": "5  \u00a9 ucles 2018 0620/11/m/j/18 [turn over  12 the diagram shows a rate of reaction experiment.    excess dilute hydrochloric acid at 25  \u00b0chydrogen magnesium     increasing the concentration of the acid and increasing the temperature both affect the rate of reaction.    which row is correct?     increase the concentration  of acid increase the temperature  a decrease rate of reaction decrease rate of reaction  b decrease rate of reaction increase rate of reaction  c increase rate of reaction decrease rate of reaction  d increase rate of reaction increase rate of reaction      13 water is added to anhydrous copper( ii) sulfate.    what happens during the reaction?  a the copper( ii) sulfate turns blue and the solution formed gets colder.  b the copper( ii) sulfate turns blue and the solution formed gets hotter.  c the copper( ii) sulfate turns white and the solution formed gets colder.  d the copper( ii) sulfate turns white and the solution formed gets hotter.      14 which equation shows an oxidation reaction?  a c  +  o 2  \u2192  co 2  b caco 3  \u2192  cao  +  co 2  c cao  +  2hc l  \u2192  cac l 2  +  h 2o  d n2o4  \u2192  2no 2     ",
            "6": "6  \u00a9 ucles 2018 0620/11/m/j/18  15 dilute nitric acid is added to a solid, f.    a gas, g, is produced which is denser than air and extinguishes a burning splint.    what are f and g?     solid f gas g  a calcium hydrogen  b calcium carbonate carbon dioxide  c calcium hydroxide hydrogen  d calcium oxide carbon dioxide      16 which statement about oxides is correct?  a a solution of magnesium oxide has a ph less than ph 7.  b a solution of sulfur dioxide has a ph greater than ph 7.  c magnesium oxide reacts with nitric acid to make a salt.  d sulfur dioxide reacts with hydrochloric acid to make a salt.      17 which methods are suitable for preparing both  zinc sulfate and copper( ii) sulfate?    1 reacting the metal oxide with warm dilute aqueous sulfuric acid  2 reacting the metal with dilute aqueous sulfuric acid 3 reacting the metal carbonate with dilute aqueous sulfuric acid    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    ",
            "7": "7  \u00a9 ucles 2018 0620/11/m/j/18 [turn over  18 two salt solutions, x and y, are tested.    the table shows the results.    test x y  a few drops of aqueous  sodium hydroxide are added green precipitate  formed red-brown  precipitate formed  a few drops of dilute nitric acid and  a few drops of barium nitrate are added no change seen   white precipitate  formed  a few drops of dilute nitric acid and  a few drops of silver nitrate are added white precipitate  formed no change seen      what are x and y?     x y  a iron(ii) chloride iron( iii) sulfate  b iron(iii) chloride iron( iii) sulfate  c iron(ii) sulfate iron( iii) chloride  d iron(iii) sulfate iron( iii) chloride      19 which element is in the same period of the periodic table as silicon?  a germanium  b scandium  c sodium  d strontium      20 which statement about the halogens is correct?  a a sample of bromine reacts with potassium chloride solution.  b a sample of bromine reacts with potassium iodide solution.  c a sample of chlorine has a higher density than a sample of bromine.  d a sample of chlorine is a darker colour than a sample of bromine.     ",
            "8": "8  \u00a9 ucles 2018 0620/11/m/j/18  21 which row shows the catalytic activity of transition elements and their compounds?    catalytic activity of   transition elements catalytic activity of compounds of  transition elements  a good good  b good poor  c poor good  d poor poor      22 which statement about the noble gases is not correct?  a noble gases are diatomic molecules.  b noble gases are unreactive gases.  c noble gases have full outer electron shells.  d the noble gas argon is used in lamps.      23 the following statements are made about the metals copper, iron, magnesium and zinc.    1 their oxides are acidic.  2 they all conduct electricity in the solid state.  3 they all have high melting points.  4 they all react with dilute acids to form hydrogen.    which statements are correct?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    ",
            "9": "9  \u00a9 ucles 2018 0620/11/m/j/18 [turn over  24 three metals, x, y and z, were reacted with water.    the oxides of the same three metals were also heated strongly with carbon.    the results are shown.    metal reaction of the metal with water reaction of the metal oxide  with carbon  x   vigorous reaction  with cold water no reaction    y   no reaction   metal and  carbon dioxide produced  z   no reaction observed with cold water  but reaction observed with steam no reaction      what is a correct conclusion about x, y and z?  a x is sodium and y is magnesium.  b x is the least reactive and y is the most reactive.  c z is less reactive than y.  d z is magnesium and y is copper.    25 in a blast furnace, iron ore is mixed with coke and limestone, and heated in hot air.    compound r is formed. compound r then reduces the iron ore to iron.    which equation shows the formation of compound r?  a c  +  o 2  \u2192  co 2  b co 2  +  c  \u2192  2co  c caco 3  \u2192  cao  +  co 2  d cao  +  sio 2  \u2192  casio 3    26 which statement explains why aluminium is used in the manufacture of aircraft?  a it conducts heat well.  b it has a low density.  c it is a good conductor of electricity.  d it is easy to recycle.    ",
            "10": "10  \u00a9 ucles 2018 0620/11/m/j/18  27 dry air is passed over hot copper until all the oxygen has reacted.    heatcopper dry air     the volume of gas at the end of the reaction is 120  cm3.    what is the starting volume of dry air?  a 132  cm3 b 152  cm3 c 180  cm3 d 570  cm3      28 a steel bicycle which had been left outdoors for several months was starting to rust.    what would not reduce the rate of corrosion?  a remove the rust and paint the bicycle.  b remove the rust and store the bicycle in a dry shed.  c remove the rust and wipe the bicycle with a clean, damp cloth.  d remove the rust and wipe the bicycle with an oily cloth.    29 which statements about water are correct?    1 household water contains dissolved salts.  2 water for household use is filtered to remove soluble impurities. 3 water is treated with chlorine to kill bacteria. 4 water is used in industry for cooling.    a 1, 2, 3 and 4  b 1, 2 and 3 only  c 1, 3 and 4 only  d 2, 3 and 4 only     30 farmers use fertilisers to replace minerals in th e soil that have been removed by the crops they  grow.    which elements in the soil are replaced by adding fertilisers?  a ca, p, o b k, o, s c n, k, p d n, o, s    ",
            "11": "11  \u00a9 ucles 2018 0620/11/m/j/18 [turn over  31 which statement is correct?  a atmospheric carbon dioxide is not a cause of climate change.  b atmospheric methane is produced by respiration.  c burning natural gas decreases the level of carbon dioxide in the atmosphere.  d decomposition of vegetation causes an increase in atmospheric methane.      32 which statement about sulfur and its compounds is not correct?  a sulfur dioxide is used as a food preservative.  b sulfur dioxide turns acidified aqueous potassium manganate( vii) from purple to colourless.  c sulfur forms a basic oxide.  d sulfur is used in the manufacture of sulfuric acid.    33 which process is used to convert limestone (calcium carbonate) into lime?  a electrolysis  b fractional distillation  c incomplete combustion  d thermal decomposition     34 lime is used to treat an industrial waste.    limeuntreated wastetreated waste     which change occurs in the treatment?     untreated waste  treated waste  a acidic \u2192 neutral  b alkaline \u2192 acidic  c alkaline \u2192 neutral  d neutral \u2192 acidic     ",
            "12": "12  \u00a9 ucles 2018 0620/11/m/j/18  35 what is not the correct use of the fraction named?   name of fraction use  a fuel oil making waxes  b gas oil fuel in diesel engines  c kerosene jet fuel  d naphtha making chemicals     36 four organic compounds are listed.    ethane  ethanoic acid  ethanol  ethene    which bond do all four compounds contain?  a c\u2013c b c\u2013h c c\u2013o d o\u2013h     37 the first three members of a homologous series are shown.    ffcf fffcf fcf fffcf fcf fcf f    why do these molecules represent a homologous series?  a because they contain fluorine and carbon atoms  b because they have saturated bonds  c because they have the same functional group  d because they react differently from each other      38 which substances can be obtained by cracking hydrocarbons?  a ethanol and ethene  b ethanol and hydrogen  c ethene and hydrogen  d ethene and poly(ethene)     ",
            "13": "13  \u00a9 ucles 2018 0620/11/m/j/18 [turn over  39 which reaction is used to make ethanol?  a adding steam to ethene  b addition polymerisation  c fractional distillation of petroleum  d reacting ethene with aqueous bromine      40 polymers are long-chain molecules made from small molecules linked together.    four polymers or types of polymer are listed.    1 carbohydrates  2 nylon 3 proteins 4 terylene     which of these polymers or types of polymer are synthetic?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "14": "14  \u00a9 ucles 2018 0620/11/m/j/18  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/11/m/j/18  blank page",
            "16": "16  \u00a9 ucles 2018 0620/11/m/j/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s18_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 15 printed pages and 1 blank page.  ib18 06_0620_12/3rp  \u00a9 ucles 2018 [turn over     *8053932751* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1 multiple choice (core)  may/june 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/12/m/j/18  1 when iodine is heated it turns from a solid to a gas.    when liquid ammonia is cooled it turns into a solid.    when ice is heated it turns into water.    which terms describe these changes of state?     when iodine  is heated when liquid  ammonia  is cooled when ice  is heated  a boiling freezing melting  b freezing sublimation boiling  c sublimation condensation freezing  d sublimation freezing melting     2 which piece of apparatus cannot  be used to collect and measure the volume of gas produced in  an experiment?  a burette  b gas syringe  c measuring cylinder  d pipette      3 pure ethanol has a melting point of \u2013114  \u00b0c and a boiling point of 78  \u00b0c.    what are the melting and boiling points of a sample of ethanol with glucose dissolved in it?     melting  point  / \u00b0c boiling  point  / \u00b0c  a \u2013116 77  b \u2013116 79  c \u2013112 77  d \u2013112 79      4 which atom has an equal number of protons, neutrons and electrons?  a 40ar b 1h c 23na d 14n     ",
            "3": "3  \u00a9 ucles 2018 0620/12/m/j/18 [turn over  5 which description of brass is correct?  a alloy  b compound  c element  d non-metal      6 the bonding between elements x and y in compound xy 2 is shown.    y y x    which row shows the type of bond in xy 2 and the type of element x?     type of bond type of element x  a covalent metal  b covalent non-metal  c ionic metal  d ionic non-metal    7 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     when the percentage of graphite is increased, the pencil slides across the paper more easily.    which statement explains this observation?  a graphite has a high melting point.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.     ",
            "4": "4  \u00a9 ucles 2018 0620/12/m/j/18  8 the equation for the reaction between magnesium and dilute sulfuric acid is shown.    the mr of mgso 4 is 120.    mg  +  h 2so 4  \u2192  mgso 4  +  h 2    which mass of magnesium sulfate is formed when 12  g of magnesium completely reacts with  dilute sulfuric acid?  a 5  g b 10  g c 60  g d 120  g      9 the electrolysis of molten lead( ii) bromide is shown.    power supply +\u2013 molten lead( ii) bromide    which statement describes what happens at the negative electrode?  a  bromide ions gain electrons to form bromine molecules.  b bromine molecules gain electrons to form bromide ions.  c lead atoms lose electrons to form lead ions.  d lead ions gain electrons to form lead atoms.      10 which statement about the combustion of fuels is correct?  a it always produces carbon dioxide.  b it always produces carbon monoxide.  c it is always endothermic.  d it is always exothermic.     ",
            "5": "5  \u00a9 ucles 2018 0620/12/m/j/18 [turn over  11 which statement about chemical reactions is correct?  a endothermic reactions show a temperature decrease because energy is absorbed from the  surroundings.  b endothermic reactions show a temperature increase because energy is released into the  surroundings.  c exothermic reactions show a temperature increase because energy is absorbed from the  surroundings.  d exothermic reactions show a temperature decrease because energy is released into the  surroundings.     12 the diagram shows a rate of reaction experiment.    excess dilute hydrochloric acid at 25  \u00b0chydrogen magnesium     increasing the concentration of the acid and increasing the temperature both affect the rate of  reaction.    which row is correct?     increase the concentration  of acid increase the temperature  a decrease rate of reaction decrease rate of reaction  b decrease rate of reaction increase rate of reaction  c increase rate of reaction decrease rate of reaction  d increase rate of reaction increase rate of reaction     ",
            "6": "6  \u00a9 ucles 2018 0620/12/m/j/18  13 reaction x shows a test for water. reaction y occurs in the blast furnace for extracting iron.    reaction x coc l 2  +  6h 2o    coc l 2.6h 2o    reaction y c  +  co 2  \u2192  2co    reaction x is ..1.. . in reaction y, the oxide co 2 is ..2.. .    which words correctly complete gaps 1 and 2?     1 2  a irreversible oxidised  b irreversible reduced  c reversible oxidised  d reversible reduced      14 which equation shows an oxidation reaction?  a c  +  o 2  \u2192  co 2  b caco 3  \u2192  cao  +  co 2  c cao  +  2hc l  \u2192  cac l 2  +  h 2o  d n2o4  \u2192  2no 2      15 which two gases each give the same result for the test shown?     test gas 1 gas 2  a damp blue litmus paper ammonia  chlorine  b damp blue litmus paper ammonia oxygen  c lighted splint hydrogen chlorine  d lighted splint hydrogen oxygen     16 which statement about oxides is correct?  a a solution of magnesium oxide has a ph less than ph 7.  b a solution of sulfur dioxide has a ph greater than ph 7.  c magnesium oxide reacts with nitric acid to make a salt.  d sulfur dioxide reacts with hydrochloric acid to make a salt.    ",
            "7": "7  \u00a9 ucles 2018 0620/12/m/j/18 [turn over  17 which methods are suitable for preparing both  zinc sulfate and copper( ii) sulfate?    1 reacting the metal oxide with warm dilute aqueous sulfuric acid  2 reacting the metal with dilute aqueous sulfuric acid 3 reacting the metal carbonate with dilute aqueous sulfuric acid    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    18 two separate tests are done on separate solutions of compound x.    1 addition of aqueous sodium hydroxide forms a green precipitate that dissolves in an  excess of aqueous sodium hydroxide.  2 addition of dilute nitric acid and aqueous silver nitrate forms a white precipitate.    what is compound x?  a chromium( iii) carbonate  b chromium( iii) chloride  c iron( ii) carbonate  d iron( ii) chloride      19 which statement about the periodic table is correct?  a elements in the same group have the same number of electron shells.  b it contains elements arranged in order of increasing proton number.  c metals are on the right and non-metals are on the left.  d the most reactive elements are at the bottom of every group.      20 chlorine, bromine and iodine are elements in group vii of the periodic table.    which statement about these elements is not correct?  a the colour gets darker down the group.  b the density increases down the group.  c they are all gases at room temperature and pressure.  d they are all non-metals.     ",
            "8": "8  \u00a9 ucles 2018 0620/12/m/j/18  21 which row describes the properties of a transition element?     property 1 property 2  a forms colourless compounds acts as a catalyst  b forms colourless compounds low electrical conductivity  c high density acts as a catalyst  d high density low electrical conductivity      22 which statement about the elements in group viii is correct?  a they all form diatomic molecules.  b they all have eight electrons in their outer shells.  c they all react with oxygen to form oxides.  d they are all gases at room temperature.      23 stainless steel is an alloy of iron, carbon and other metals.    which row is correct?     stainless steel is  harder than pure iron stainless steel resists  corrosion better than  pure iron  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     ",
            "9": "9  \u00a9 ucles 2018 0620/12/m/j/18 [turn over  24 a student is given metal z and its oxide.    the student does some experiments to find out the position of metal z in the reactivity series.    the results are shown.    \u25cf metal z reacted slowly with dilute hydrochloric acid.  \u25cf metal z reacted slowly with steam but not with water.  \u25cf the oxide of metal z reacted when heated with carbon.    which statement about the position of metal z in the reactivity series is correct?  a it is between calcium and sodium.  b it is between copper and hydrogen.  c it is between hydrogen and iron.  d it is between magnesium and calcium.     25 iron is produced from iron ore in a blast furnace.    waste gases slaghot air molten ironraw materials zone 3 zone 2 zone 1     which equation represents the main reaction that happens in zone 1?  a c(s)  +  co 2(g)  \u2192  2co(g)  b c(s)  +  o 2(g)  \u2192  co 2(g)  c fe2o3(s)  +  3co(g)  \u2192  2fe(l)  +  3co 2(g)  d fe3o4(s)  +  co(g)  \u2192  3feo(s)  +  co 2(g)   ",
            "10": "10  \u00a9 ucles 2018 0620/12/m/j/18  26 which row describes the use of an alloy and the property upon which the use depends?     alloy use property  a mild steel cutlery resistant to corrosion  b mild steel machinery strong  c stainless steel cutlery low density  d stainless steel machinery good conductor of electricity       27 dry air is passed over hot copper until all the oxygen has reacted.    heatcopper dry air     the volume of gas at the end of the reaction is 120  cm3.    what is the starting volume of dry air?  a 132  cm3 b 152  cm3 c 180  cm3 d 570  cm3      28 a steel bicycle which had been left outdoors for several months was starting to rust.    what would not reduce the rate of corrosion?  a remove the rust and paint the bicycle.  b remove the rust and store the bicycle in a dry shed.  c remove the rust and wipe the bicycle with a clean, damp cloth.  d remove the rust and wipe the bicycle with an oily cloth.    ",
            "11": "11  \u00a9 ucles 2018 0620/12/m/j/18 [turn over  29 which statements about water are correct?    1 household water contains dissolved salts.  2 water for household use is filtered to remove soluble impurities.  3 water is treated with chlorine to kill bacteria.  4 water is used in industry for cooling.    a 1, 2, 3 and 4  b 1, 2 and 3 only  c 1, 3 and 4 only  d 2, 3 and 4 only    30 ammonium nitrate is a common fertiliser used by farmers to increase the yield of their crops.    which compound reacts with ammonium nitrate to form ammonia?  a calcium hydroxide  b potassium nitrate  c sodium chloride  d sodium phosphate    31 which process does not release a greenhouse gas?  a digestion of food in cows  b reaction between zinc and hydrochloric acid  c respiration by animals  d thermal decomposition of calcium carbonate     32 which row describes the uses of sulfur and sulfur dioxide?     sulfur sulfur dioxide  a extraction of aluminium food preservative  b extraction of aluminium water treatment  c manufacture of sulfuric acid food preservative  d manufacture of sulfuric acid water treatment     ",
            "12": "12  \u00a9 ucles 2018 0620/12/m/j/18  33 limestone is used in many industrial processes.    in which process is it not used?  a manufacture of alkenes  b manufacture of cement  c manufacture of iron  d manufacture of lime    34 lime is used to treat an industrial waste.    limeuntreated wastetreated waste     which change occurs in the treatment?     untreated waste  treated waste  a acidic \u2192 neutral  b alkaline \u2192 acidic  c alkaline \u2192 neutral  d neutral \u2192 acidic      35 what is not the correct use of the fraction named?   name of fraction use  a fuel oil making waxes  b gas oil fuel in diesel engines  c kerosene jet fuel  d naphtha making chemicals     ",
            "13": "13  \u00a9 ucles 2018 0620/12/m/j/18 [turn over  36 four organic compounds are listed.    ethane  ethanoic acid  ethanol  ethene    which bond do all four compounds contain?  a c\u2013c b c\u2013h c c\u2013o d o\u2013h    37 which compounds belong to the same homologous series?  a ethane and propane  b ethanoic acid and ethanol  c methane and ethene  d propene and ethanoic acid     38 which substances can be obtained by cracking hydrocarbons?  a ethanol and ethene  b ethanol and hydrogen  c ethene and hydrogen  d ethene and poly(ethene)    39 the equations for two important processes used to manufacture ethanol are shown.    process 1 c 6h12o6  \u2192  2c 2h5oh  +  2co 2  process 2 c 2h4  +  h 2o  \u2192  c2h5oh    which statement is not correct?  a both processes require a catalyst.  b both processes use a starting material obtained from petroleum.  c process 1 shows the production of a renewable fuel.  d process 2 is an addition reaction.     ",
            "14": "14  \u00a9 ucles 2018 0620/12/m/j/18  40 part of the label on the packet of a potato product is shown.    this potato product contains:    starch  ethanoic acid sodium chloride sugar    which constituent is a natural polymer?  a ethanoic acid  b sodium chloride  c starch  d sugar    ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/12/m/j/18  blank page",
            "16": "16  \u00a9 ucles 2018 0620/12/m/j/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s18_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 15 printed pages and 1 blank page.  ib18 06_0620_13/3rp  \u00a9 ucles 2018 [turn over     *4491578785 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1 multiple choice (core)  may/june 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/13/m/j/18  1 mineral wool soaked in aqueous ammonia is placed in the apparatus shown.    mineral wool soaked in aqueous ammoniadamp red litmus paper    after five minutes, the damp red litmus paper turned blue.    which process led to this change?  a crystallisation  b diffusion  c distillation  d sublimation      2 solid r reacted with dilute sulfuric acid.    the initial temperature of the dilute sulfuric acid and the final temperature of the solution are  shown.    25 20151025201510 initial temperature of the dilute sulfuric acid ( \u00b0c)final temperature of the solution ( \u00b0c)     what was the change in temperature in \u00b0c?  a \u2013  6 b \u2013  4 c 4 d 6     ",
            "3": "3  \u00a9 ucles 2018 0620/13/m/j/18 [turn over  3 the melting points of four impure samples of lead( ii) bromide were measured. the results are  shown.    which sample is the most pure?     temperature when  the sample started  to melt  / \u00b0c temperature when  the sample finished  melting  / \u00b0c  a 342 355  b 353 360  c 365 371  d 372 373      4 symbols representing four particles are shown.    w40 20          +2 41 20x          y37 18          z3717    the letters are not the chemical symbols.    which particles have the same number of neutrons?  a w and x2+ b w and z c x2+ and y d y and z      5 which name is given to a pure substance made from more than one type of atom?  a alloy  b compound  c element  d mixture     ",
            "4": "4  \u00a9 ucles 2018 0620/13/m/j/18  6 the diagram shows solid element q reacting with an acid to produce gas r.    solid element qgas r acid     which row describes q and r?     q r  a metal element with covalent bonds  b metal element with ionic bonds  c non-metal compound with covalent bonds  d non-metal compound with ionic bonds      7 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     when the percentage of graphite is increased, the pencil slides across the paper more easily.    which statement explains this observation?  a graphite has a high melting point.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.    8 the equation for the reaction between magnesium and dilute sulfuric acid is shown.    the m r of mgso 4 is 120.    mg  +  h 2so 4  \u2192  mgso 4  +  h 2    which mass of magnesium sulfate is formed when 12  g of magnesium completely reacts with  dilute sulfuric acid?  a 5  g b 10  g c 60  g d 120  g   ",
            "5": "5  \u00a9 ucles 2018 0620/13/m/j/18 [turn over  9 what is produced at each electrode when molten rubidium chloride is electrolysed using platinum  electrodes?     positive electrode negative electrode  a chlorine hydrogen  b chlorine rubidium  c hydrogen chlorine  d rubidium chlorine      10 what is released when any fuel is burned?  a carbon dioxide  b heat energy  c smoke  d water     11 group i metals react vigorously with water and release heat.    which statement about this reaction is correct?  a the reaction is endothermic and the energy change is negative.  b the reaction is endothermic and the energy change is positive.  c the reaction is exothermic and the energy change is negative.  d the reaction is exothermic and the energy change is positive.    ",
            "6": "6  \u00a9 ucles 2018 0620/13/m/j/18  12 the diagram shows a rate of reaction experiment.    excess dilute hydrochloric acid at 25  \u00b0chydrogen magnesium     increasing the concentration of the acid and increasing the temperature both affect the rate of reaction.    which row is correct?     increase the concentration  of acid increase the temperature  a decrease rate of reaction decrease rate of reaction  b decrease rate of reaction increase rate of reaction  c increase rate of reaction decrease rate of reaction  d increase rate of reaction increase rate of reaction     13 in a chemical reaction, blue compound x changed into white compound y.    x     \u2192     y   blue white    which statement describes this reaction?  a hydrated cobalt( ii) chloride is heated.  b hydrated copper( ii) sulfate is heated.  c water is added to anhydrous cobalt( ii) chloride.  d water is added to anhydrous copper( ii) sulfate.      14 which equation shows an oxidation reaction?  a c  +  o 2  \u2192  co 2  b caco 3  \u2192  cao  +  co 2  c cao  +  2hc l  \u2192  cac l 2  +  h 2o  d n2o4  \u2192  2no 2     ",
            "7": "7  \u00a9 ucles 2018 0620/13/m/j/18 [turn over  15 pieces of damp red litmus paper and damp blue litmus paper are placed in three different gas  jars.    gas jar 1red litmus paperblue litmuspaper ammonia gas jar 2chlorine gas jar 3oxygenred litmus paperblue litmuspaperred litmus paperblue litmuspaper     in which gas jars does at least one piece of litmus paper change colour?  a 1, 2 and 3 b 1 and 2 c 1 and 3 d 2 and 3     16 which statement about oxides is correct?  a a solution of magnesium oxide has a ph less than ph 7.  b a solution of sulfur dioxide has a ph greater than ph 7.  c magnesium oxide reacts with nitric acid to make a salt.  d sulfur dioxide reacts with hydrochloric acid to make a salt.     17 which methods are suitable for preparing both  zinc sulfate and copper( ii) sulfate?    1 reacting the metal oxide with warm dilute aqueous sulfuric acid  2 reacting the metal with dilute aqueous sulfuric acid  3 reacting the metal carbonate with dilute aqueous sulfuric acid    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      18 a white crystalline solid is dissolved in distilled water.    a small amount of dilute nitric acid is added followed by aqueous silver nitrate.    no visible change occurs.    what can be deduced about the white crystalline solid?  a it contains chloride ions.  b it does not contain ammonium ions.  c it does not contain carbonate ions.  d it must contain either sulfate or nitrate ions.     ",
            "8": "8  \u00a9 ucles 2018 0620/13/m/j/18  19 which element is classified as a non-metal in the periodic table?  a calcium  b chlorine  c chromium  d copper      20 part of the periodic table is shown.    element q has a low boiling point, low density and does not conduct electricity.    which element is q?    b cda      21 which row describes a typical transition element?     density  in g  / cm3 melting point  in \u00b0c boiling point  in \u00b0c colour of  oxide  a 0.97 98 883 white  b 2.64 769 1382 white  c 3.10 \u20137 59 yellow  d 8.96 1085 2562 red      22 helium is a noble gas.    which statement is correct?  a a helium atom has eight electrons in its outer shell.  b helium exists as diatomic molecules.  c helium is used as an inert atmosphere in lamps.  d there are no naturally occurring chemical compounds of helium.     ",
            "9": "9  \u00a9 ucles 2018 0620/13/m/j/18 [turn over  23 which diagram represents a solid alloy?    a b cd       24 some reactions of three metals and their oxides are shown.    metal metal reacts  with steam metal oxide  reacts with carbon  x no yes  y yes no  z yes yes    what is the order of reactivity of the metals?     most  reactive  least  reactive  a x z y  b y x z  c y z x  d z y x     25 which statement about the extraction of metals is correct?  a aluminium is extracted from bauxite by electrolysis.  b aluminium is extracted from hematite by heating with carbon.  c iron is extracted from bauxite by heating with carbon.  d iron is extracted from hematite by electrolysis.     26 which statement explains why aluminium is used to manufacture aircraft?  a it has a low density.  b it is a good conductor of electricity.  c it is a good conductor of heat.  d it is ductile.    ",
            "10": "10  \u00a9 ucles 2018 0620/13/m/j/18  27 dry air is passed over hot copper until all the oxygen has reacted.    heatcopper dry air     the volume of gas at the end of the reaction is 120  cm3.    what is the starting volume of dry air?  a 132  cm3 b 152  cm3 c 180  cm3 d 570  cm3      28 a steel bicycle which had been left outdoors for several months was starting to rust.    what would not reduce the rate of corrosion?  a remove the rust and paint the bicycle.  b remove the rust and store the bicycle in a dry shed.  c remove the rust and wipe the bicycle with a clean, damp cloth.  d remove the rust and wipe the bicycle with an oily cloth.    29 which statements about water are correct?    1 household water contains dissolved salts.  2 water for household use is filtered to remove soluble impurities. 3 water is treated with chlorine to kill bacteria. 4 water is used in industry for cooling.    a 1, 2, 3 and 4  b 1, 2 and 3 only  c 1, 3 and 4 only  d 2, 3 and 4 only    ",
            "11": "11  \u00a9 ucles 2018 0620/13/m/j/18 [turn over  30 fertilisers are often mixtures of solid compounds.    which compounds can be mixed to provide the three elements needed for healthy plant growth?  a ammonium nitrate and calcium phosphate  b ammonium nitrate and potassium chloride  c ammonium phosphate and potassium chloride  d potassium chloride and calcium phosphate    31 carbon dioxide and methane are both greenhouse gases which contribute to climate change.    which statement explains how greenhouse gases contribute to climate change?  a they absorb heat radiation from the earth.  b they absorb heat radiation from the sun.  c they absorb light radiation from the sun.  d they cause acid rain.    32 element z forms an oxide, zo 2. three uses of zo 2 are listed.    \u25cf bleaching agent  \u25cf killing bacteria  \u25cf manufacturing an important acid    what is z?  a carbon  b lead  c nitrogen  d sulfur     ",
            "12": "12  \u00a9 ucles 2018 0620/13/m/j/18  33 limestone is an important material with many uses.    limestone is heated to produce ..1.. and carbon dioxide.    this reaction is called ..2.. .    which words correctly complete gaps 1 and 2?     1 2  a lime neutralisation  b lime thermal decomposition  c slaked lime neutralisation  d slaked lime thermal decomposition      34 lime is used to treat an industrial waste.    limeuntreated wastetreated waste     which change occurs in the treatment?     untreated waste  treated waste  a acidic \u2192 neutral  b alkaline \u2192 acidic  c alkaline \u2192 neutral  d neutral \u2192 acidic     35 what is not the correct use of the fraction named?   name of fraction use  a fuel oil making waxes  b gas oil fuel in diesel engines  c kerosene jet fuel  d naphtha making chemicals     ",
            "13": "13  \u00a9 ucles 2018 0620/13/m/j/18 [turn over  36 four organic compounds are listed.    ethane  ethanoic acid  ethanol  ethene    which bond do all four compounds contain?  a c\u2013c b c\u2013h c c\u2013o d o\u2013h     37 the structures of some organic compounds are shown.    1 hch hch ho h2 hch hch hhh c h hch hch hhh c o h3 4 o ohch hch hc h    which compounds belong to the same homologous series?  a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4     38 which substances can be obtained by cracking hydrocarbons?  a ethanol and ethene  b ethanol and hydrogen  c ethene and hydrogen  d ethene and poly(ethene)    ",
            "14": "14  \u00a9 ucles 2018 0620/13/m/j/18  39 sugars and ethene can both be made into ethanol using different reactions.    which type of reaction is used in each case?     sugars to ethanol ethene to ethanol  a fermentation addition  b fermentation cracking  c incomplete combustion addition  d incomplete combustion cracking     40 which substances are natural polymers?     ethanol protein starch vinegar  a \u0016 \u0016 \u0016 \u0016  b \u0016 \u001a \u0016 \u001a  c \u001a \u0016 \u0016 \u001a  d \u001a \u001a \u001a \u0016     ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/13/m/j/18  blank page",
            "16": "16  \u00a9 ucles 2018 0620/13/m/j/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s18_qp_21.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 13 printed pages and 3 blank pages.  ib18 06_0620_21/3rp  \u00a9 ucles 2018 [turn over     *1264661612 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/21     paper 2 multiple choice (extended)  may/june 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/21/m/j/18  1 a student investigated the diffusion of ammonia gas, nh 3, and hydrogen chloride gas, hc l.    two sets of apparatus were set up as shown at room temperature and pressure.    apparatus 1source of ammonia gasdamp red litmus paper apparatus 2source of hydrogen chloride gasdamp bluelitmus paper     the damp red litmus paper in apparatus 1 changed colour after 30 seconds.    how long does it take for the damp blue litmus paper to change colour in apparatus 2?  a 64 seconds  b 30 seconds  c 21 seconds  d the blue litmus paper would not change colour.     2 chromatography is a technique used to separate coloured dyes.    which dye has an r f value of 0.7?    solvent front baseline ab dyescd      ",
            "3": "3  \u00a9 ucles 2018 0620/21/m/j/18 [turn over  3 which piece of apparatus is used to measure exactly 26.3  cm3 of a liquid?    abcd      4 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     when the percentage of graphite is increased, the pencil slides across the paper more easily.    which statement explains this observation?  a graphite has a high melting point.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.     ",
            "4": "4  \u00a9 ucles 2018 0620/21/m/j/18  5 chlorine exists as two common isotopes, 35cl and 37cl.    information about these two isotopes is shown.     number of  protons number of  neutrons number of  electron shells  35cl 17 18 3  37cl 17 20 3    which statement explains why the two isotopes are of the same element?  a both have the same number of electron shells.  b both have the same number of protons.  c both have 7 outer shell electrons.  d 37cl has 2 more neutrons than 35cl.      6 which substance is not a macromolecule?  a diamond  b graphite  c silicon( iv) oxide  d sulfur    7 copper is a metallic element.    which statements about copper are correct?    1 copper is malleable because layers of ions are in fixed positions and cannot move.  2 the structure of copper consists of negative ions in a lattice. 3 copper conducts electricity because electrons can move through the metal. 4 electrons hold copper ions together in a lattice by electrostatic attraction.    a 1 and 2 b 2, 3 and 4 c 2 and 3 only d 3 and 4 only    8 the equation for the combustion of ethane is shown.    2c 2h6  +  7o 2  \u2192  4co 2  +  6h 2o    which volume of carbon dioxide, at room temperature and pressure, is formed when 0.5  moles of  ethane burn?  a 48  dm3 b 24  dm3 c 12  dm3 d 6  dm3     ",
            "5": "5  \u00a9 ucles 2018 0620/21/m/j/18 [turn over  9 a solution of ethanoic acid, ch 3cooh, has a concentration of 2  mol  / dm3.    which statement about this solution is correct?  a 20  g of ethanoic acid is dissolved in 10  cm3 of water.  b 30  g of ethanoic acid is dissolved in 250  cm3 of water.  c 60  g of ethanoic acid is dissolved in 1  dm3 of water.  d 120  g of ethanoic acid is dissolved in 2  dm3 of water.     10 aqueous copper( ii) sulfate is electrolysed using copper electrodes.    which statement is correct?  a a reduction reaction occurs at the positive electrode.  b the blue colour of the solution becomes darker.  c the concentration of copper ions in the solution decreases.  d the mass of the negative electrode increases.    11 dilute sulfuric acid is electrolysed using inert electrodes.    what are the ionic half-equations for the reactions that take place at each electrode?     positive electrode negative electrode  a 2h+  +  2e\u2013  \u2192  h2 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013  b 2h+  +  2e\u2013  \u2192  h2 4oh\u2013  +  4h+  \u2192  4h 2o  c 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013 2h+  +  2e\u2013  \u2192  h2  d 4oh\u2013  +  4h+  \u2192  4h 2o 2h+  +  2e\u2013  \u2192  h2      12 plant cells use energy from sunlight for photosynthesis.    which row describes and explains the energy change that occurs?     type of  energy change explanation  a endothermic less energy is released making bonds than is absorbed to break bonds  b endothermic more energy is released making bonds than is absorbed to break bonds  c exothermic less energy is released making bonds than is absorbed to break bonds  d exothermic more energy is released making bonds than is absorbed to break bonds     ",
            "6": "6  \u00a9 ucles 2018 0620/21/m/j/18  13 hydrogen bromide decomposes to form hydrog en and bromine. the equation is shown.    2hbr(g)  \u2192  h2(g)  +  br 2(g)    the bond energies are shown in the table. the reaction is endothermic.    bond bond energy  in kj  / mol  br\u2013br +193  h\u2013br +366  h\u2013h +436    what is the energy change for the reaction?  a +263  kj / mol b +103  kj / mol c \u2013103  kj / mol d \u2013263  kj / mol    14 which row describes the effects of increasing both concentration and temperature on the  collisions between reacting particles?     increasing concentration increasing temperature  a more collisions per second only more collisions per second only  b   more collisions per second and more  collisions with sufficient energy to react more collisions per second only    c   more collisions per second only   more collisions per second and more  collisions with sufficient energy to react  d   more collisions per second and more  collisions with sufficient energy to react more collisions per second and more  collisions with sufficient energy to react     15 the formation of sulfur trioxide is a reversible reaction.    the equation is shown.    2so 2(g)  +  o 2(g)    2so 3(g)    the forward reaction is exothermic.    which conditions produce the highest equilibrium yield of sulfur trioxide?     pressure temperature  a high high  b high low  c low high  d low low     ",
            "7": "7  \u00a9 ucles 2018 0620/21/m/j/18 [turn over  16 chlorine displaces iodide ions from potassium iodide.    cl 2  +  2 i\u2013  \u2192  i2  +  2c l \u2013    what is the oxidising agent?  a chloride ions  b chlorine  c iodide ions  d iodine    17 which statement about oxides is correct?  a a solution of magnesium oxide has a ph less than ph 7.  b a solution of sulfur dioxide has a ph greater than ph 7.  c magnesium oxide reacts with nitric acid to make a salt.  d sulfur dioxide reacts with hydrochloric acid to make a salt.     18 which solution has the lowest ph?  a 0.1  mol  / dm3 ammonia solution  b 0.1  mol  / dm3 ethanoic acid  c 0.1  mol  / dm3 lithium hydroxide  d 0.1  mol  / dm3 nitric acid    19 a student mixes silver nitrate and barium chloride to form a white precipitate of silver chloride.    the equation is shown.    2agno 3  +  bac l 2  \u2192  2agc l  +  ba(no 3)2    which row describes the solubility of the salts?     soluble insoluble  a   silver nitrate   barium chloride, barium nitrate  and silver chloride  b silver nitrate and barium chloride barium nitrate and silver chloride  c   silver nitrate, barium chloride  and barium nitrate silver chloride    d   silver nitrate, barium chloride  and silver chloride barium nitrate      ",
            "8": "8  \u00a9 ucles 2018 0620/21/m/j/18  20 which methods are suitable for preparing both  zinc sulfate and copper( ii) sulfate?    1 reacting the metal oxide with warm dilute aqueous sulfuric acid  2 reacting the metal with dilute aqueous sulfuric acid 3 reacting the metal carbonate with dilute aqueous sulfuric acid    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     21 which element is in the same period of the periodic table as silicon?  a germanium  b scandium  c sodium  d strontium     22 which statement about the halogens is correct?  a a sample of bromine reacts with potassium chloride solution.  b a sample of bromine reacts with potassium iodide solution.  c a sample of chlorine has a higher density than a sample of bromine.  d a sample of chlorine is a darker colour than a sample of bromine.    23 which row shows the catalytic activity of transition elements and their compounds?    catalytic activity of   transition elements catalytic activity of compounds of  transition elements  a good good  b good poor  c poor good  d poor poor     24 the following statements are made about the metals copper, iron, magnesium and zinc.    1 their oxides are acidic.  2 they all conduct electricity in the solid state. 3 they all have high melting points. 4 they all react with dilute acids to form hydrogen.    which statements are correct?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4 ",
            "9": "9  \u00a9 ucles 2018 0620/21/m/j/18 [turn over  25 silver is a less reactive metal than cadmium.    cadmium is a less reactive metal than barium.    which statement is correct?  a barium does not react when heated with silver oxide.  b cadmium displaces barium from a solution of barium chloride.  c cadmium displaces silver from a solution of silver nitrate.  d cadmium reacts when heated with barium oxide.     26 aluminium metal is extracted from aluminium oxide using electrolysis.    which statement about the extraction process is not correct?  a a large amount of electricity is required.  b molten cryolite is used to dissolve the aluminium oxide.  c oxygen gas is released which reacts to form carbon dioxide.  d the negative electrodes burn away and have to be replaced.      27 which statement explains why aluminium is used in the manufacture of aircraft?  a it conducts heat well.  b it has a low density.  c it is a good conductor of electricity.  d it is easy to recycle.      28 dry air is passed over hot copper until all the oxygen has reacted.    heatcopper dry air     the volume of gas at the end of the reaction is 120  cm3.    what is the starting volume of dry air?  a 132  cm3 b 152  cm3 c 180  cm3 d 570  cm3     ",
            "10": "10  \u00a9 ucles 2018 0620/21/m/j/18  29 a steel bicycle which had been left outdoors for several months was starting to rust.    what would not reduce the rate of corrosion?  a remove the rust and paint the bicycle.  b remove the rust and store the bicycle in a dry shed.  c remove the rust and wipe the bicycle with a clean, damp cloth.  d remove the rust and wipe the bicycle with an oily cloth.    30 which statements about water are correct?    1 household water contains dissolved salts.  2 water for household use is filtered to remove soluble impurities. 3 water is treated with chlorine to kill bacteria. 4 water is used in industry for cooling.    a 1, 2, 3 and 4  b 1, 2 and 3 only  c 1, 3 and 4 only  d 2, 3 and 4 only     31 ammonia is manufactured by reacting hydrogen with nitrogen in the haber process.    which row describes the sources of hydrogen and nitrogen and the conditions used in the  manufacture of ammonia in the haber process?     source of  hydrogen source of  nitrogen temperature of  reaction  / \u00b0c pressure of  reaction  / atm  a air natural gas 250 2  b air natural gas 250 200  c natural gas air 450 2  d natural gas air 450 200      32 which statements about the carbon cycle are correct?    1 carbon dioxide is added to the atmosphere by respiration.  2 carbon dioxide is added to the atmosphere by combustion of coal. 3 carbon dioxide is removed from the atmosphere by photosynthesis.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    ",
            "11": "11  \u00a9 ucles 2018 0620/21/m/j/18 [turn over  33 which statement about sulfur and its compounds is not correct?  a sulfur dioxide is used as a food preservative.  b sulfur dioxide turns acidified aqueous potassium manganate( vii) from purple to colourless.  c sulfur forms a basic oxide.  d sulfur is used in the manufacture of sulfuric acid.    34 which process is used to convert lim estone (calcium carbonate) into lime?  a electrolysis  b fractional distillation  c incomplete combustion  d thermal decomposition    35 what is not the correct use of the fraction named?   name of fraction use  a fuel oil making waxes  b gas oil fuel in diesel engines  c kerosene jet fuel  d naphtha making chemicals      36 which reaction is not a reaction which alkenes undergo?  a bromination  b hydration  c hydrogenation  d hydrolysis      37 which substances can be obtained by cracking hydrocarbons?  a ethanol and ethene  b ethanol and hydrogen  c ethene and hydrogen  d ethene and poly(ethene)     ",
            "12": "12  \u00a9 ucles 2018 0620/21/m/j/18  38 ethanol is produced by fermentation or from ethene.    what is a disadvantage of producing ethanol by fermentation?  a distillation is needed to purify the ethanol produced.  b fermentation uses glucose from plants.  c fermentation is catalysed by enzymes in yeast.  d fermentation occurs at a low temperature and pressure.     39 which structural formula represents methyl propanoate?  a ch 3ch 2cooch 3  b ch 3cooch 2ch 2ch 3  c ch 3ch 2ch 2cooch 3  d hcooch 2ch 2ch 3    40 which row describes addition polymerisation and condensation polymerisation?     addition polymerisation condensation polymerisation  a   monomers have a c=c double bond  and the polymer is the only product monomers have a c=c double bond  and the polymer is the only product  b   monomers have a c=c double bond  and the polymer is the only product the monomers react to form the  polymer and a small molecule  c   the monomers react to form the  polymer and a small molecule monomers have a c=c double bond  and the polymer is the only product  d   the monomers react to form the  polymer and a small molecule the monomers react to form the  polymer and a small molecule     ",
            "13": "13  \u00a9 ucles 2018 0620/21/m/j/18  blank page",
            "14": "14  \u00a9 ucles 2018 0620/21/m/j/18  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/21/m/j/18  blank page",
            "16": "16  \u00a9 ucles 2018 0620/21/m/j/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s18_qp_22.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 13 printed pages and 3 blank pages.  ib18 06_0620_22/3rp  \u00a9 ucles 2018 [turn over     *2609976664 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2 multiple choice (extended)  may/june 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/22/m/j/18  1 a gas is released at point x in the apparatus shown.    x damp universal indicator paper    which gas turns the damp universal indicator paper red most quickly?  a ammonia, nh 3  b chlorine, c l 2  c hydrogen chloride, hc l  d sulfur dioxide, so 2     2 a chromatography experiment was done to separate a mixture of four substances.    the r f values measured for these substances were 0.3, 0.5, 0.8 and 0.8.    which diagram shows the chromatogram obtained?    a solvent front baselineb c d     3 which piece of apparatus cannot  be used to collect and measure the volume of gas produced in  an experiment?  a burette  b gas syringe  c measuring cylinder  d pipette     ",
            "3": "3  \u00a9 ucles 2018 0620/22/m/j/18 [turn over  4 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     when the percentage of graphite is increased, the pencil slides across the paper more easily.    which statement explains this observation?  a graphite has a high melting point.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.     5 which pair shows particles with the same chemical properties?  a  m23 11 and +m23 11   b m23 11 and m24 11  c m23 11 and m23 12  d +m24 11  and +m24 12      6 which substances have similar structures?  a diamond and graphite  b diamond and silicon( iv) oxide  c graphite and poly(ethene)  d graphite and silicon( iv) oxide     7 which substance is not a macromolecule?  a diamond  b graphite  c silicon( iv) oxide  d sulfur    ",
            "4": "4  \u00a9 ucles 2018 0620/22/m/j/18  8 the equation for the reaction between potassium carbonate and nitric acid is shown.    k2co 3  +  2hno 3  \u2192  2kno 3  +  h 2o  +  co 2    which volume of carbon dioxide is produced from 69  g of potassium carbonate?  a 6 dm3 b 12  dm3 c 24  dm3 d 48  dm3    9 a solution of sodium carbonate, na 2co 3, has a concentration of 0.03  mol  / dm3.    which mass of sodium carbonate is dissolved in 1  dm3 of this solution?  a 1.06  g b 3.18  g c 10.60  g d 31.80  g      10 aqueous copper( ii) sulfate is electrolysed using copper electrodes.    which statement about the electrolysis is not correct?  a an oxidation reaction occurs at the positive electrode.  b the current is carried through the electrolyte by ions.  c the negative electrode gains mass.  d the number of copper( ii) ions in the electrolyte decreases.     11 dilute sulfuric acid is electrolysed using inert electrodes.    what are the ionic half-equations for the reactions that take place at each electrode?     positive electrode negative electrode  a 2h+  +  2e\u2013  \u2192  h2 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013  b 2h+  +  2e\u2013  \u2192  h2 4oh\u2013  +  4h+  \u2192  4h 2o  c 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013 2h+  +  2e\u2013  \u2192  h2  d 4oh\u2013  +  4h+  \u2192  4h 2o 2h+  +  2e\u2013  \u2192  h2     ",
            "5": "5  \u00a9 ucles 2018 0620/22/m/j/18 [turn over  12 which diagram is a correctly labelled energy level diagram for an endothermic reaction?    a activation energyoverall energy change reactantsproductsb activation energyoverall energy change reactantsproducts c activation energyoverall energy changereactants productsactivation energy overall energy changereactants productsdenergy energy energy energyprogress of reaction progress of reaction progress of reaction progress of reaction     13 the equation for the complete combustion of methane is shown.    ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(g)    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013h +410  c=o +805  o\u2013h +460  o=o +496    what is the energy change for the reaction?  a \u2013818 kj  / mol b \u2013359 kj  / mol c \u2013323 kj  / mol d +102 kj  / mol    ",
            "6": "6  \u00a9 ucles 2018 0620/22/m/j/18  14 which row describes the effects of increasing both concentration and temperature on the  collisions between reacting particles?     increasing concentration increasing temperature  a more collisions per second only more collisions per second only  b   more collisions per second and more  collisions with sufficient energy to react more collisions per second only    c   more collisions per second only   more collisions per second and more  collisions with sufficient energy to react  d   more collisions per second and more  collisions with sufficient energy to react more collisions per second and more  collisions with sufficient energy to react    15 sulfur dioxide reacts with oxygen at 2 atmosphe res pressure. the forward reaction is exothermic.     the equation for the reaction is shown.    2so 2(g)  +  o 2(g)    2so 3(g)    the reaction reaches equilibrium. the pressure is then doubled.    how and why does the amount of sulfur trioxide formed change?     amount of sulfur trioxide reason  a decreases the forward reaction is exothermic  b decreases there are fewer molecules on the right  c increases the forward reaction is exothermic  d increases there are fewer molecules on the right      16 iron( ii) chloride solution reacts with chlorine gas.    the equation is shown.    2fec l 2(aq)  +  c l 2(g)  \u2192  2fec l 3(aq)    which statements about this reaction are correct?    1 fe2+ ions are reduced to fe3+ ions.  2 chlorine acts as a reducing agent. 3 fe 2+ ions each lose an electron.  4 c l 2 molecules are reduced to c l \u2013 ions.    a 1 and 2 b 2 and 3 c 2 and 4 d 3 and 4     ",
            "7": "7  \u00a9 ucles 2018 0620/22/m/j/18 [turn over  17 which statement about oxides is correct?  a a solution of magnesium oxide has a ph less than ph 7.  b a solution of sulfur dioxide has a ph greater than ph 7.  c magnesium oxide reacts with nitric acid to make a salt.  d sulfur dioxide reacts with hydrochloric acid to make a salt.      18 which statement about acids and bases is correct?  a a base is a donor of hydrogen ions.  b an acid is an acceptor of protons.  c a strong acid is fully ionised in aqueous solution.  d a weak acid cannot be used to neutralise a strong base.      19 the solubility of some salts is shown.     chloride nitrate sulfate carbonate  barium soluble soluble insoluble insoluble  lead( ii) insoluble soluble insoluble insoluble  potassium soluble soluble soluble soluble  zinc soluble soluble soluble insoluble    which two aqueous solutions produce an insoluble salt when mixed together?  a barium chloride and zinc nitrate  b barium nitrate and lead( ii) nitrate  c lead( ii) nitrate and potassium carbonate  d potassium nitrate and zinc sulfate     20 which methods are suitable for preparing both  zinc sulfate and copper( ii) sulfate?    1 reacting the metal oxide with warm dilute aqueous sulfuric acid  2 reacting the metal with dilute aqueous sulfuric acid  3 reacting the metal carbonate with dilute aqueous sulfuric acid    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    ",
            "8": "8  \u00a9 ucles 2018 0620/22/m/j/18  21 which statement about the periodic table is correct?  a elements in the same group have the same number of electron shells.  b it contains elements arranged in order of increasing proton number.  c metals are on the right and non-metals are on the left.  d the most reactive elements are at the bottom of every group.      22 chlorine, bromine and iodine are elements in group vii of the periodic table.    which statement about these elements is not correct?  a the colour gets darker down the group.  b the density increases down the group.  c they are all gases at room temperature and pressure.  d they are all non-metals.    23 which row describes the properties of a transition element?     property 1 property 2  a forms colourless compounds acts as a catalyst  b forms colourless compounds low electrical conductivity  c high density acts as a catalyst  d high density low electrical conductivity     24 stainless steel is an alloy of iron, carbon and other metals.    which row is correct?     stainless steel is  harder than pure iron stainless steel resists  corrosion better than  pure iron  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     ",
            "9": "9  \u00a9 ucles 2018 0620/22/m/j/18 [turn over  25 metal x is more reactive than metal y. metal y is more reactive than metal z.    which statement is correct?  a when metal x is placed in a solution of y sulfate, there is no reaction.  b when metal x is placed in a solution of z sulfate, a reaction occurs.  c when metal y is placed in a solution of z sulfate, there is no reaction.  d when metal z is placed in a solution of x sulfate, a reaction occurs.     26 which statement about the industrial extraction of zinc is correct?  a cryolite is added to lower the melting point.  b molten zinc oxide is electrolysed.  c zinc oxide is heated with coke.  d zinc sulfide is heated with coke.    27 which row describes the use of an alloy and the property upon which the use depends?     alloy use property  a mild steel cutlery resistant to corrosion  b mild steel machinery strong  c stainless steel cutlery low density  d stainless steel machinery good conductor of electricity      28 dry air is passed over hot copper until all the oxygen has reacted.    heatcopper dry air     the volume of gas at the end of the reaction is 120  cm3.    what is the starting volume of dry air?  a 132  cm3 b 152  cm3 c 180  cm3 d 570  cm3     ",
            "10": "10  \u00a9 ucles 2018 0620/22/m/j/18  29 a steel bicycle which had been left outdoors for several months was starting to rust.    what would not reduce the rate of corrosion?  a remove the rust and paint the bicycle.  b remove the rust and store the bicycle in a dry shed.  c remove the rust and wipe the bicycle with a clean, damp cloth.  d remove the rust and wipe the bicycle with an oily cloth.    30 which statements about water are correct?    1 household water contains dissolved salts.  2 water for household use is filtered to remove soluble impurities. 3 water is treated with chlorine to kill bacteria. 4 water is used in industry for cooling.    a 1, 2, 3 and 4  b 1, 2 and 3 only  c 1, 3 and 4 only  d 2, 3 and 4 only     31 ammonia is manufactured by reacting hydrogen with nitrogen in the haber process.    which row describes the sources of hydrogen and nitrogen and the conditions used in the  manufacture of ammonia in the haber process?     source of  hydrogen source of  nitrogen temperature of  reaction  / \u00b0c pressure of  reaction  / atm  a air natural gas 250 2  b air natural gas 250 200  c natural gas air 450 2  d natural gas air 450 200      32 which statements about the carbon cycle are correct?    1 carbon dioxide is added to the atmosphere by respiration.  2 carbon dioxide is added to the atmosphere by combustion of coal. 3 carbon dioxide is removed from the atmosphere by photosynthesis.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    ",
            "11": "11  \u00a9 ucles 2018 0620/22/m/j/18 [turn over  33 which row describes the uses of sulfur and sulfur dioxide?     sulfur sulfur dioxide  a extraction of aluminium food preservative  b extraction of aluminium water treatment  c manufacture of sulfuric acid food preservative  d manufacture of sulfuric acid water treatment      34 limestone is used in many industrial processes.    in which process is it not used?  a manufacture of alkenes  b manufacture of cement  c manufacture of iron  d manufacture of lime     35 what is not the correct use of the fraction named?   name of fraction use  a fuel oil making waxes  b gas oil fuel in diesel engines  c kerosene jet fuel  d naphtha making chemicals      36 which statement about alkenes is not correct?  a they decolourise aqueous bromine.  b they only contain the elements carbon and hydrogen.  c they react with hydrogen to form alkanes.  d they react with steam to produce carboxylic acids.     37 which substances can be obtained by cracking hydrocarbons?  a ethanol and ethene  b ethanol and hydrogen  c ethene and hydrogen  d ethene and poly(ethene)    ",
            "12": "12  \u00a9 ucles 2018 0620/22/m/j/18  38 two processes used for the large-scale production of ethanol are shown.    process 1 a compound containing carbon, hydrogen and oxygen is used to produce  ethanol.  process 2 a compound containing carbon and hydrogen only is used to produce  ethanol.    which statement is correct?  a process 1 uses a renewable starting material.  b process 1 is done at a very high temperature.  c process 2 involves fermentation.  d process 2 is done at room temperature.    39 what is the name of the organic product of the reaction shown?    ch 3cooh  +  ch 3ch 2oh  \u2192    a ethyl ethanoate  b ethyl methanoate  c methyl ethanoate  d methyl propanoate     40 which two compounds react together to form a condensation polymer?  a hoch 2ch 2oh and ch 3cooh  b hoch 2ch 2oh and ch 3nh 2  c hoch 2ch 2oh and h 2nch 2ch 2nh 2  d hoch 2ch 2oh and hoocch 2ch 2cooh    ",
            "13": "13  \u00a9 ucles 2018 0620/22/m/j/18  blank page",
            "14": "14  \u00a9 ucles 2018 0620/22/m/j/18  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/22/m/j/18  blank page",
            "16": "16  \u00a9 ucles 2018 0620/22/m/j/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s18_qp_23.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 14 printed pages and 2 blank pages.  ib18 06_0620_23/3rp  \u00a9 ucles 2018 [turn over     *8762427084 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/23     paper 2 multiple choice (extended)  may/june 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/23/m/j/18  1 ammonia gas is reacted with hydrogen chloride gas using the apparatus shown.    solid ammonium chloride is produced.      cotton wool soaked in ammonia solutioncotton wool soaked in hydrogen chloride solutionlong glass tube solid ammonium chloride     which statement explains why the solid amm onium chloride is formed nearer to the  hydrogen chloride?  a ammonia solution is a base and hydrogen chloride solution is an acid.  b ammonia molecules diffuse more slowly than hydrogen chloride molecules.  c hydrogen chloride has a greater molecular mass than ammonia.  d hydrogen chloride moves by brownian motion.     2 paper chromatography is done in the same way with three different mixtures of dyes. each  mixture contains at least one of the dyes w, x, y and z.    the r f values of the dyes in the three mixtures are shown.    dye rf values from  mixture 1 rf values from  mixture 2 rf values from  mixture 3  w 0.15 0.15 0.15  x 0.00 0.00 0.00  y 0.50 0.50 0.50  z 0.00 0.91 0.91    which conclusion is correct?  a dye w is nearest the solvent front and is present only in mixture 1 and mixture 3.  b dye x has travelled furthest up the chromatography paper.  c dye y is the only dye present in all three mixtures.  d dye z is nearest the solvent front and is found in only two of the mixtures.     ",
            "3": "3  \u00a9 ucles 2018 0620/23/m/j/18 [turn over  3 solid r reacted with dilute sulfuric acid.    the initial temperature of the dilute sulfuric acid and the final temperature of the solution are  shown.    25 20151025201510 initial temperature of the dilute sulfuric acid ( \u00b0c)final temperature of the solution ( \u00b0c)     what was the change in temperature in \u00b0c?  a \u2013  6 b \u2013  4 c 4 d 6     4 the \u2018lead\u2019 in a pencil is made of a mixture of graphite and clay.    \u2018lead\u2019     when the percentage of graphite is increased, the pencil slides across the paper more easily.    which statement explains this observation?  a graphite has a high melting point.  b graphite is a form of carbon.  c graphite is a lubricant.  d graphite is a non-metal.      5 iron has an atomic number of 26. it occurs as the isotopes 54fe, 56fe, 57fe and 58fe.    which statement explains why these isotopes have the same chemical properties?  a they have similar mass numbers.  b they have the same number of electrons in their outer shells.  c they have the same number of neutrons in their nuclei.  d they have the same number of protons in their nuclei.   ",
            "4": "4  \u00a9 ucles 2018 0620/23/m/j/18  6 how many silicon atoms are bonded to each oxygen atom in a crystal of silicon( iv) oxide?  a 1 b 2 c 3 d 4      7 which substance is not a macromolecule?  a diamond  b graphite  c silicon( iv) oxide  d sulfur      8 an experiment was done to determine the formula of a hydrocarbon, c xhy.    10  cm3 of the gaseous hydrocarbon, c xhy, was burned in an excess of oxygen to form 20  cm3 of  carbon dioxide and 30  cm3 of water vapour.    what is c xhy?  a ch 4 b c 2h4 c c 2h6 d c 3h8    9 4.00  g of solid sodium hydroxide is added to water to make a solution with a concentration of  0.200  mol  / dm3.    what is the volume of water used?  a 0.5  cm3 b 20  cm3 c 500  cm3 d 2000  cm3      10 aqueous copper( ii) sulfate is electrolysed using copper electrodes.    which statement is correct?  a oxygen gas is produced at the positive electrode.  b the blue colour of the solution gradually fades.  c the concentration of copper ions in the solution stays the same.  d the mass of the negative electrode decreases.     ",
            "5": "5  \u00a9 ucles 2018 0620/23/m/j/18 [turn over  11 dilute sulfuric acid is electrolysed using inert electrodes.    what are the ionic half-equations for the reactions that take place at each electrode?     positive electrode negative electrode  a 2h+  +  2e\u2013  \u2192  h2 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013  b 2h+  +  2e\u2013  \u2192  h2 4oh\u2013  +  4h+  \u2192  4h 2o  c 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013 2h+  +  2e\u2013  \u2192  h2  d 4oh\u2013  +  4h+  \u2192  4h 2o 2h+  +  2e\u2013  \u2192  h2     12 information about two reactions is given.    \u2022 the neutralisation reaction between citric acid and sodium hydrogencarbonate is endothermic.    \u2022 the displacement reaction between magnesium and carbon dioxide is exothermic.    which statements about the two reactions are correct?    1 the energy of the products formed in the neutralisation reaction is greater than the  energy of the reactants.  2 the energy of magnesium and carbon dioxide is greater than the energy of  magnesium oxide and carbon.  3 in an exothermic reaction, the energy required to break the bonds is greater than the  energy released when the new bonds are formed.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     13 ethene reacts with hydrogen. the equation is shown.    ch 2=ch 2  +  h 2  \u2192  c2h6    the bond energies are shown in the table. the reaction is exothermic.    bond bond energy  in kj  / mol  c\u2013c +350  c=c +610  c\u2013h +410  h\u2013h +436    what is the energy change for the reaction?  a \u2013560 kj  / mol b \u2013124 kj  / mol c +486 kj  / mol d +5496 kj  / mol    ",
            "6": "6  \u00a9 ucles 2018 0620/23/m/j/18  14 which row describes the effects of increasing both concentration and temperature on the  collisions between reacting particles?     increasing concentration increasing temperature  a more collisions per second only more collisions per second only  b   more collisions per second and more  collisions with sufficient energy to react more collisions per second only    c   more collisions per second only   more collisions per second and more  collisions with sufficient energy to react  d   more collisions per second and more  collisions with sufficient energy to react more collisions per second and more  collisions with sufficient energy to react    15 in the contact process, sulfur dioxide is converted into sulfur trioxide in a reversible reaction.    2so 2(g)  +  o 2(g)    2so 3(g)    the forward reaction is exothermic.    which conditions give the highest yield of sulfur trioxide at equilibrium?     pressure  / atmospheres temperature  a 0.5 high  b 0.5 low  c 1.5 high  d 1.5 low     16 the equation for a redox reaction is shown.    2fe 3+  +  zn  \u2192  2fe2+  +  zn2+    which statements are correct?    1 fe3+ is reduced to form fe2+.  2 zn oxidises the fe3+ ions.  3 fe3+ is an oxidising agent.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "7": "7  \u00a9 ucles 2018 0620/23/m/j/18 [turn over  17 which statement about oxides is correct?  a a solution of magnesium oxide has a ph less than ph 7.  b a solution of sulfur dioxide has a ph greater than ph 7.  c magnesium oxide reacts with nitric acid to make a salt.  d sulfur dioxide reacts with hydrochloric acid to make a salt.      18 the equation represents an equilibrium in aqueous ammonia.    nh 3(aq)  +  h 2o(l)    nh 4+(aq)  +  oh\u2013(aq)    how does aqueous ammonia behave in this reaction?  a as a strong acid  b as a strong base  c as a weak acid  d as a weak base    19 an excess of aqueous sodium sulfate was added to aqueous barium chloride and the mixture  was filtered.    which row shows the identity of the residue and the substances present in the filtrate?     residue substances in filtrate  a barium sulfate barium chloride and sodium chloride  b barium sulfate sodium chloride and sodium sulfate  c sodium chloride barium chloride and sodium sulfate  d sodium chloride barium sulfate and sodium sulfate      20 which methods are suitable for preparing both  zinc sulfate and copper( ii) sulfate?    1 reacting the metal oxide with warm dilute aqueous sulfuric acid  2 reacting the metal with dilute aqueous sulfuric acid  3 reacting the metal carbonate with dilute aqueous sulfuric acid    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "8": "8  \u00a9 ucles 2018 0620/23/m/j/18  21 which element is classified as a non-metal in the periodic table?  a calcium  b chlorine  c chromium  d copper      22 part of the periodic table is shown.    element q has a low boiling point, low density and does not conduct electricity.    which element is q?    b cda      23 which row describes a typical transition element?     density  in g  / cm3 melting point  in \u00b0c boiling point  in \u00b0c colour of  oxide  a 0.97 98 883 white  b 2.64 769 1382 white  c 3.10 \u20137 59 yellow  d 8.96 1085 2562 red      24 which diagram represents a solid alloy?    a b cd      ",
            "9": "9  \u00a9 ucles 2018 0620/23/m/j/18 [turn over  25 the ionic equations for four reactions are shown.    z  +  x2+  \u2192  z2+  +  x  z  +  2w+  \u2192  z2+  +  2w  x  +  2w+  \u2192  x2+  +  2w  y  +  z2+  \u2192  y2+  +  z    what is the order of reactivity of the four metals, w, x, y and z?     most  reactive  least  reactive  a w x z y  b x w y z  c y z x w  d z w x y      26 which equation represents the first stage in the extraction of zinc from zinc blende?  a 2zns  +  3o 2  \u2192  2zno  +  2so 2  b zns  +  h 2o  \u2192  zno  +  h 2s  c zno  +  co  \u2192  zn  +  co 2  d zno  +  h 2so 4  \u2192  znso 4  +  h 2o      27 which statement explains why aluminium is used to manufacture aircraft?  a it has a low density.  b it is a good conductor of electricity.  c it is a good conductor of heat.  d it is ductile.     ",
            "10": "10  \u00a9 ucles 2018 0620/23/m/j/18  28 dry air is passed over hot copper until all the oxygen has reacted.    heatcopper dry air     the volume of gas at the end of the reaction is 120  cm3.    what is the starting volume of dry air?  a 132  cm3 b 152  cm3 c 180  cm3 d 570  cm3      29 a steel bicycle which had been left outdoors for several months was starting to rust.    what would not reduce the rate of corrosion?  a remove the rust and paint the bicycle.  b remove the rust and store the bicycle in a dry shed.  c remove the rust and wipe the bicycle with a clean, damp cloth.  d remove the rust and wipe the bicycle with an oily cloth.    30 which statements about water are correct?    1 household water contains dissolved salts.  2 water for household use is filtered to remove soluble impurities. 3 water is treated with chlorine to kill bacteria. 4 water is used in industry for cooling.    a 1, 2, 3 and 4  b 1, 2 and 3 only  c 1, 3 and 4 only  d 2, 3 and 4 only    ",
            "11": "11  \u00a9 ucles 2018 0620/23/m/j/18 [turn over  31 ammonia is manufactured by reacting hydrogen with nitrogen in the haber process.    which row describes the sources of hydrogen and nitrogen and the conditions used in the  manufacture of ammonia in the haber process?     source of  hydrogen source of  nitrogen temperature of  reaction  / \u00b0c pressure of  reaction  / atm  a air natural gas 250 2  b air natural gas 250 200  c natural gas air 450 2  d natural gas air 450 200      32 which statements about the carbon cycle are correct?    1 carbon dioxide is added to the atmosphere by respiration.  2 carbon dioxide is added to the atmosphere by combustion of coal.  3 carbon dioxide is removed from the atmosphere by photosynthesis.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    33 element z forms an oxide, zo 2. three uses of zo 2 are listed.    \u25cf bleaching agent  \u25cf killing bacteria  \u25cf manufacturing an important acid    what is z?  a carbon  b lead  c nitrogen  d sulfur     ",
            "12": "12  \u00a9 ucles 2018 0620/23/m/j/18  34 limestone is an important material with many uses.    limestone is heated to produce ..1.. and carbon dioxide.    this reaction is called ..2.. .    which words correctly complete gaps 1 and 2?     1 2  a lime neutralisation  b lime thermal decomposition  c slaked lime neutralisation  d slaked lime thermal decomposition      35 what is not the correct use of the fraction named?   name of fraction use  a fuel oil making waxes  b gas oil fuel in diesel engines  c kerosene jet fuel  d naphtha making chemicals     36 methane, ethane and propane belong to a family of hydrocarbons called alkanes.    what is the general formula of an alkane?  a c nh2n b c nh2n+1 c c nh2n\u20131 d c nh2n+2      37 which substances can be obtained by cracking hydrocarbons?  a ethanol and ethene  b ethanol and hydrogen  c ethene and hydrogen  d ethene and poly(ethene)     ",
            "13": "13  \u00a9 ucles 2018 0620/23/m/j/18  38 which row describes an advantage and a disadvantage of making ethanol by fermentation?     advantage disadvantage  a uses a renewable resource occurs at a slow rate  b needs a high temperature produces impure ethanol as a product  c produces pure ethanol as a product needs a high temperature  d occurs at a slow rate uses a non-renewable resource      39 which esters have the molecular formula c 5h10o2?    1 ethyl propanoate  2 propyl ethanoate  3 butyl methanoate 4 methyl butanoate    a 1, 2, 3 and 4  b 1, 2 and 3 only  c 1 and 2 only  d 3 and 4 only    40 a polymer linkage contains carbon, hydrogen, nitrogen and oxygen atoms.    which row about the polymer is correct?     type of  polymer formed by  a polyamide addition polymerisation  b polyamide condensation polymerisation  c polyester addition polymerisation  d polyester condensation polymerisation     ",
            "14": "14  \u00a9 ucles 2018 0620/23/m/j/18  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/23/m/j/18  blank page",
            "16": "16  \u00a9 ucles 2018 0620/23/m/j/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s18_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31 paper 3  theory (core) may/june 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib18 06_0620_31/2rp\u00a9 ucles 2018 *9841440026* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/31/m/j/18 \u00a9 ucles 2018 1  the names of eight gases are given. ammonia argon carbon dioxide helium hydrogen methane neon sulfur dioxide  (a)  answer the following questions about these gases.   each gas may be used once, more than once or not at all.   state which gas:  (i)  turns damp red litmus paper blue   ...   [1]  (ii)  contributes to the formation of acid rain   ...   [1]  (iii)  is a hydrocarbon which contributes to climate change   ...   [1]  (iv)  is a product of the reaction of copper( ii) carbonate with hydrochloric acid   ...   [1]  (v)  is a monatomic gas which has atoms with the electronic structure 2,8,8.   ...   [1]  (b) (i)  explain why helium and not hydrogen is used to fill party balloons.   ...   [1]  (ii)  give one use of argon.   ...   [1]  (c)  carbon dioxide is a compound.   what is meant by the term compound ?      ..   [1]",
            "3": "3 0620/31/m/j/18 \u00a9 ucles 2018 [turn over  (d)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  ammonia. show outer shell electrons only. h h hn  [2]  [total: 10]",
            "4": "4 0620/31/m/j/18 \u00a9 ucles 2018 2  the table shows the percentage by volume of each of the gases present in the exhaust gases from  a petrol engine. name percentage by volume carbon monoxide 1.0 carbon dioxide hydrogen 0.2 nitrogen 77.0 nitrogen dioxide 0.3 oxygen 0.7 hydrocarbons 0.3 water vapour 5.0 total 100.0  (a) (i)  calculate the percentage by volume of carbon dioxide in the exhaust gases.  ..%  [1]  (ii)  which gas shown in the table is present in the lowest percentage by volume?   ...   [1]  (iii)  which two elements in the table combine to form nitrogen dioxide?  ... and     [1]  (iv)  give the formula for nitrogen dioxide.   ...   [1]  (v)  where does the nitrogen in the exhaust gases come from?   ...   [1]  (b)  the carbon monoxide in the exhaust gases comes from the incomplete combustion of hydrocarbons.  (i)  what is meant by the term hydrocarbon ?   .   ...   [2]  (ii)  give one adverse effect of carbon monoxide on health.   ...   [1]",
            "5": "5 0620/31/m/j/18 \u00a9 ucles 2018 [turn over  (iii)  balance the chemical equation for the complete combustion of pentane.  c5h12  +  8o2    .co2  +  .h2o [2]  [total: 10]",
            "6": "6 0620/31/m/j/18 \u00a9 ucles 2018 3  limonene is a volatile liquid which smells of oranges.  (a)  a teacher placed a beaker of limonene at the front of a classroom.   at first, the students at the back of the classroom could not smell the limonene.   after two minutes, the smell of limonene had spread throughout the classroom.   the air in the classroom was still and calm.  (i)  explain these observations using the kinetic particle model.   .   .   .   .   ...   [3]  (ii)  the melting point of limonene is \u201374 \u00b0c.   the boiling point of limonene is 176 \u00b0c.   what is the physical state of limonene at \u2013 80 \u00b0c?   explain your answer.   .   ...   [2]  (b)  an enzyme present in peppermint plants is a catalyst for the oxidation of limonene.   state what is meant by the terms:  (i) catalyst   .   ...   [1]  (ii) oxidation   .   ...   [1]",
            "7": "7 0620/31/m/j/18 \u00a9 ucles 2018 [turn over  (c)  limonene can be made from a colourless compound called \u03b1-terpineol.   the structure of \u03b1-terpineol is shown. chh cch3ccc cc hhh hhch3 hch3 oh  (i)  what feature of the structure of the \u03b1-terpineol molecule shows that it is an unsaturated  compound?   ...   [1]  (ii)  describe how the colour of aqueous bromine changes when an excess of \u03b1-terpineol is added to it.  from  .. to    [2]  [total: 10]",
            "8": "8 0620/31/m/j/18 \u00a9 ucles 2018 4  this question is about iron and its compounds.  (a)  the table shows how easy it is to reduce four metal oxides by heating with carbon. metal oxide ease of reduction with carbon chromium( iii) oxide only reduced above 1700 \u00b0c iron( iii) oxide only reduced above 650 \u00b0c magnesium oxide not reduced at 1750 \u00b0c nickel( ii) oxide only reduced above 300 \u00b0c   use this information to put the metals in order of their reactivity. put the least reactive metal  first. least reactive most reactive  [2]  (b)  iron is a transition element. potassium is an element in group i of the periodic table.   describe three ways in which the properties of iron differ from those of potassium.  1  .  2  .  3  .  [3] (c)  iron wire burns in oxygen.   balance the chemical equation for this reaction.  .fe  +  .o 2    fe3o4 [2]  (d)  pure iron can be made by reducing iron( iii) oxide, fe2o3, with hydrogen. fe2o3  +  3h2    2fe  +  3h2o   how does this equation show that iron( iii) oxide is reduced?      ..   [1]",
            "9": "9 0620/31/m/j/18 \u00a9 ucles 2018 [turn over  (e)  when iron reacts with dilute hydrochloric acid, iron( ii) chloride is formed.  (i)  describe a test for iron( ii) ions.  test  ..  result  ...  [2]  (ii)  another chloride of iron has the structure shown. fecl clfecl clcl cl   deduce the molecular formula of this compound showing the number of iron and chlorine  atoms.   ...   [1]  (f)  some iron nails were placed in bottles under different conditions. d c b a moist airboiled water water iron nails anhydrou s calcium chlorid e to dry the air   in which bottles will the iron nails not rust?   give reasons for your answer.          ..   [2]  [total: 13]",
            "10": "10 0620/31/m/j/18 \u00a9 ucles 2018 5 (a)  complete the sentence about electrolysis using words from the list. breakdown        compound        electricity        electroplating  element gaseous heat molten   electrolysis is the .. of an ionic .. when   .. or in aqueous solution by the passage of .. .  [4]  (b)  molten zinc iodide can be electrolysed using the apparatus shown. +\u2013   on the diagram, label:  \u25cfthe anode  \u25cfthe cathode  \u25cfthe electrolyte [2]  (c)  why are the electrodes made of graphite?   ..   [1]  (d)  predict the products of the electrolysis of molten zinc iodide at:  the negative electrode  ...  the positive electrode.    [2] (e)  when chlorine is bubbled through a colourless aqueous solution of zinc iodide, the solution  turns brown.   name the brown substance. suggest, using ideas about reactivity of the halogens, why this  reaction occurs.      ..   [2]  [total: 11]",
            "11": "11 0620/31/m/j/18 \u00a9 ucles 2018 [turn over 6  this question is about isotopes.  (a)  an atom of an isotope of fluorine is represented by the symbol shown. 19f9   describe the structure of an atom of this isotope of fluorine.   in your answer, include:  \u25cf the position of the protons, neutrons and electrons in the atom  \u25cf the number of protons, neutrons and electrons present in the atom.                     ..   [5]  (b)  complete the sentence about isotopes using words from the list. atomic        compound        element        ions        molecular        nucleons   isotopes are atoms of the same .. which have the same  .. number but different numbers of .. .  [3]  (c) give one medical use of radioactive isotopes.   ..   [1]  (d)  which one of the following isotopes is used as a source of energy?   draw a circle around the correct answer. 131xe54127i53235u9266zn30  [1]  [total: 10]",
            "12": "12 0620/31/m/j/18 \u00a9 ucles 2018 7 this question is about group i elements and their compounds.  (a)  the properties of some group i elements are shown in the table. elementboiling point / \u00b0catomic radius / pmrelative thermal  conductivityobservations when it reacts with cold water sodium 883 186 3.9rapid bubbling but does not burst into flame potassium 759 227very rapid bubbling and bursts into flame rubidium 688 1.6 caesium 671 265 1.0 explodes  (i)  complete the table to estimate:  \u25cfthe relative thermal conductivity of potassium  \u25cfthe atomic radius of rubidium.  [2]  (ii)  describe the trend in the boiling points of the group i elements.   ...   [1]  (iii)  use the information in the table to predict what you would observe when rubidium reacts  with cold water.   ...   [1]  (b)  which one of the statements about the formation of a sodium ion from a sodium atom is  correct?   tick one box.  a sodium atom gains an electron.  a sodium atom loses an electron.  a sodium atom loses a proton.  a sodium atom gains a proton.  [1]",
            "13": "13 0620/31/m/j/18 \u00a9 ucles 2018 [turn over  (c)  is sodium oxide an acidic oxide or a basic oxide?   give a reason for your answer.      ..   [1]  (d)  a compound of sodium has the formula c4h5na.   calculate the relative formula mass of c4h5na.   show all your working.   use your periodic table to help you.  relative formula mass = ..  [2]   (e)  complete the word equation for the reaction of sodium hydroxide with sulfuric acid. sodium hydroxide+sulfuric acid.. ..+..  [2] [total: 10]",
            "14": "14 0620/31/m/j/18 \u00a9 ucles 2018 8  when zinc reacts with hydrochloric acid, hydrogen gas is produced.   the graph shows how the volume of hydrogen gas produced changes with time when an excess of  zinc is reacted with 0.2 mol / dm3 hydrochloric acid. 80 60 40 20 0volume of hydrogen gas  / cm3 time  / min02468 10 12  (a)  explain why the volume of hydrogen gas remains constant after six minutes.   ..   [1]  (b)  what volume of hydrogen gas was released in the first two minutes of the reaction?   ..   [1]  (c)  the experiment is repeated using the same volume of 0.1 mol / dm3 hydrochloric acid.   all other conditions are kept the same.   on the grid , draw the graph for the experiment using 0.1 mol / dm3 hydrochloric acid. [2]  (d)  give the name of the salt formed when zinc reacts with hydrochloric acid.   ..   [1]  (e)  which one of the following ph values could be the ph of dilute hydrochloric acid?   draw a circle around the correct answer.  ph 1            ph 7            ph 9            ph 13 [1]  [total: 6]",
            "15": "15 0620/31/m/j/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.",
            "16": "16 0620/31/m/j/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s18_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32 paper 3  theory (core) may/june 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib18 06_0620_32/2rp\u00a9 ucles 2018 *3868593465* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/m/j/18 \u00a9 ucles 2018 1  the names of nine gases are given. ammonia carbon monoxide chlorine ethane ethene helium hydrogen neon oxygen  (a)  answer the following questions about these gases.   each gas may be used once, more than once or not at all.   state which gas:  (i)  bleaches damp litmus paper   ...   [1]  (ii)  dissolves in water to form an alkali   ...   [1]  (iii)  is a monatomic gas with ten protons in its nucleus   ...   [1]  (iv)  is formed when hydrocarbons undergo incomplete combustion   ...   [1]  (v)  is an unsaturated hydrocarbon.   ...   [1]  (b)  diatomic hydrogen molecules contain covalent bonds.   state what is meant by the terms:  (i) diatomic   ..   ...   [1]  (ii) covalent bonds   ...   ...   [1]",
            "3": "3 0620/32/m/j/18 \u00a9 ucles 2018 [turn over  (c)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  chlorine. show outer shell electrons only. cl cl  [2]  [total: 9]",
            "4": "4 0620/32/m/j/18 \u00a9 ucles 2018 2  the table shows the percentage by volume of each of the gases present in the exhaust gases from  a petrol engine with a catalytic converter. name percentage by volume carbon monoxide 0.20 carbon dioxide 15.00 hydrocarbons 0.02 hydrogen 0.01 nitrogen oxides of nitrogen 0.02 water vapour 12.75 total 100.00  (a) (i)  calculate the percentage by volume of nitrogen in the exhaust gases.  ..%  [1]  (ii)  which gas shown in the table is present in the lowest percentage by volume?   ...   [1]  (b) (i)  give one adverse effect of oxides of nitrogen on health.   ...   [1]  (ii)  balance the chemical equation for the reaction of nitrogen dioxide with sodium hydroxide.  .no2  +  .naoh    nano3  +  nano2  +  h2o [2]  (iii)  state the name of the salt with the formula nano3.   ...   [1]  (c)  petrol contains saturated hydrocarbons.   state what is meant by the terms:  (i) saturated  .   ...   [1]  (ii) hydrocarbon      ...   [2]",
            "5": "5 0620/32/m/j/18 \u00a9 ucles 2018 [turn over  (d)  the table shows the composition of a sample of dry natural gas. name of gas percentage by volume methane 95.0 ethane 3.2 propane 0.2 butane 0.1 carbon dioxide 0.5 nitrogen 1.0 total 100.0   calculate the percentage by volume of hydrocarbons in the sample of dry natural gas.  ..%  [1]  [total: 10]",
            "6": "6 0620/32/m/j/18 \u00a9 ucles 2018 3 (a)  the structures of two compounds, a and b, are shown. c c h hn hh h ch s compound ahoo hc c n hh h ch o compound bhooh  (i)  how many different types of atoms are present in compound a?   ...   [1]  (ii)  on structure b draw a circle around the alcohol functional group. [1]  (iii)  compounds a and b are formed in the body by enzyme-catalysed reactions.   what is the purpose of a catalyst?   ...   [1]  (iv)  enzymes are polymers of compounds called amino acids.   what is meant by the term polymer ?   .   ...   [1]  (b)  ethanoic acid is a carboxylic acid.  (i)  give one property of ethanoic acid.   ...   [1]  (ii)  complete the structure of ethanoic acid showing all of the atoms and all of the bonds. ch hh  [1]",
            "7": "7 0620/32/m/j/18 \u00a9 ucles 2018 [turn over  (c)  ethanoic acid can be made by the oxidation of ethanol.  (i)  the melting point of ethanol is \u2013114 \u00b0c.   the boiling point of ethanol is 78 \u00b0c.   what is the physical state of ethanol at \u2013120 \u00b0c?   explain your answer.   .   ...   [2]  (ii)  complete the sentences about the manufacture of ethanol using words from the list.  a catalyst       addition       an enzyme       cracking  ethane ethene high low   ethanol can be manufactured by the .. of steam to .. .   the reaction takes place at a .. temperature in the presence of     .. . [4]  [total: 12]",
            "8": "8 0620/32/m/j/18 \u00a9 ucles 2018 4  this question is about manganese and its compounds.  (a)  potassium manganate( vii) is soluble in water.   a purple crystal of potassium manganate( vii) was placed in the middle of a piece of damp  filter paper.   after 1 hour, the purple colour had spread over most of the filter paper. crystal of potassium manganate( vii) at the start after 1 hour   explain these observations using the kinetic particle model.               ..   [3]  (b)  potassium manganate( vii) is produced from manganese( iv) oxide by an oxidation reaction.   what is meant by the term oxidation ?      ..   [1]  (c)  potassium manganate( vii) decomposes when heated. the products are oxygen and  manganese( iv) oxide.  (i)  describe a test for oxygen.  test  ..  result  ...  [2]  (ii)  manganese( iv) oxide reacts with concentrated hydrochloric acid.   balance the chemical equation for this reaction. mno2  +  hc l    mncl 2  +  c l 2  +  h2o  [2]",
            "9": "9 0620/32/m/j/18 \u00a9 ucles 2018 [turn over  (d)  the table compares the reactivity of four metals with hydrochloric acid of the same concentration. metal reactivity with hydrochloric acid lead no bubbles seen. metal does not disappear. magnesium rapid formation of bubbles. metal disappears rapidly. manganese steady formation of bubbles. metal disappears slowly. tin bubbles formed slowly. metal disappears very slowly.   use this information to put the metals in order of their reactivity. put the least reactive metal  first. least reactive most reactive  [2]  (e)  manganese is a transition element. sodium is an element in group i of the periodic table.   describe three ways in which the properties of manganese differ from those of sodium.  1  .  2  .  3  .  [3]  [total: 13]",
            "10": "10 0620/32/m/j/18 \u00a9 ucles 2018 5 (a)  electrolysis of concentrated aqueous sodium  chloride can be done using the apparatus shown. power supplyelectrolyte electrodes +\u2013  (i)  during electrolysis, a gas is produced at each electrode.   complete the diagram to show how the gases can be collected. [1]  (ii)  the positive electrode is called the anode.   state the name of the negative electrode.   ...   [1]  (iii)  predict the main products of the electrolysis of concentrated aqueous sodium chloride at:  the negative electrode    the positive electrode.  .  [2]  (iv)  give the name of a suitable element to use as the electrodes in this electrolysis.   ...   [1]",
            "11": "11 0620/32/m/j/18 \u00a9 ucles 2018 [turn over  (b)  sodium hydroxide is manufactured by the electrolysis of sodium chloride.  (i)  after electrolysis, 1000 cm3 of solution contains 750 g of sodium hydroxide.   what mass of sodium hydroxide is present in 200 cm3 of this solution?   ...   [1]  (ii)  what effect would impurities have on the melting point of sodium hydroxide?   ...   [1]  (c)  describe how you could prepare a sample of solid sodium chloride from a solution of  sodium chloride.   ..   [1]  [total: 8]",
            "12": "12 0620/32/m/j/18 \u00a9 ucles 2018 6  this question is about isotopes.  (a)  an atom of an isotope of nitrogen is represented by the symbol shown. 15n7   describe the structure of an atom of this isotope of nitrogen.   in your answer, include:  \u25cf the position of the protons, neutrons and electrons in the atom  \u25cf the number of protons, neutrons and electrons present in the atom.                     ..   [5]  (b)  what is meant by the term isotopes ?         ..   [2]  (c)  give one industrial use of radioactive isotopes.   ..   [1]  [total: 8]",
            "13": "13 0620/32/m/j/18 \u00a9 ucles 2018 [turn over 7 (a)  the properties of some group vii elements are shown in the table. elementmelting point in \u00b0cboiling point in \u00b0cdensity at room temperature in g / cm3 colour chlorine \u2013101 \u201335 0.0032 green bromine \u20137 59 3.1 red-brown iodine 114 184 grey-black astatine 337 6.4  (i)  complete the table to suggest:  \u25cfthe density of iodine  \u25cfthe melting point of astatine  \u25cfthe colour of astatine.  [3]  (ii)  suggest why the density of chlorine at room temperature is much lower than the density  of bromine and astatine at room temperature.   .   ...   [1]  (iii)  describe the trend in the boiling points of the halogens.   ...   [1]  (b)  aqueous bromine reacts with aqueous potassium iodide.   complete the word equation for this reaction. bromine +potassium iodide..+.. ..  [2]  (c)  a compound has the formula c2f4cl 2.   calculate the relative molecular mass of c2f4cl 2.   show all your working.   use your periodic table to help you.  relative molecular mass = ..  [2]  [total: 9]",
            "14": "14 0620/32/m/j/18 \u00a9 ucles 2018 8  the energy released by burning four different fuels is compared using the apparatus shown.   a known mass of each fuel is burned and the temperature rise of the water is measured. thermometer steel can flame fuelclam p water  (a)  suggest two factors that should be kept constant in this experiment.  1  .  2  .  [2]  (b)  the table shows the temperature changes when four different fuels, a, b, c and d, are burned. fuelmass of fuel burned / ginitial temperature of the water / \u00b0cfinal temperature of the water / \u00b0c a 2 20 30 b 1 18 24 c 4 21 37 d 2 20 28   which fuel gave the greatest temperature rise per gram?   ..   [1]  (c)  ethanol is a fuel.   give one other use of ethanol.   ..   [1]",
            "15": "15 0620/32/m/j/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (d)  the energy level diagram for the complete combustion of ethanol is shown. energyethanol  +  .. carbon dioxide  +  . . progress of reaction  (i)  complete the diagram by filling in the missing reactant and the missing product. [2]  (ii)  is the complete combustion of ethanol exothermic or endothermic?   use the information in the diagram to explain your answer.   .   ...   [1]  (e)  a steel can is used in the experiment.  (i)  stainless steel is an alloy of iron.   what is meant by the term alloy ?   .   ...   [1]  (ii)  describe the arrangement and type of motion of the particles in solid iron.  arrangement  ...  type of motion  .  [2]  (iii)  suggest why stainless steel is used instead of pure iron for making cutlery.   .   ...   [1]  [total: 11]",
            "16": "16 0620/32/m/j/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s18_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 20.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33 paper 3  theory (core) may/june 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 17 printed pages and 3 blank pages. [turn overib18 06_0620_33/2rp\u00a9 ucles 2018 *3497163988* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/33/m/j/18 \u00a9 ucles 2018 1  the names of seven gases are given. ammonia ethene helium hydrogen hydrogen chloride methane nitrogen  (a)  answer the following questions about these gases.   each gas may be used once, more than once or not at all.   state which gas:  (i)  forms an acidic solution in water   ...   [1]  (ii)  is monatomic   ...   [1]  (iii)  forms 78% of clean dry air   ...   [1]  (iv)  is the main constituent of natural gas   ...   [1]  (v)  has molecules which each contain 14 protons.   ...   [1]  (b) (i)  give the names of two elements in the list.  . and    [1]  (ii)  what is meant by the term element  ?   ...   [1]",
            "3": "3 0620/33/m/j/18 \u00a9 ucles 2018 [turn over  (c)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  hydrogen chloride. show outer electrons only. hc l  [2]  [total: 9]",
            "4": "4 0620/33/m/j/18 \u00a9 ucles 2018 2 (a)  the table shows the percentage by volume of each of the gases present in the exhaust gases  from a petrol engine and a diesel engine. namepercentage by volume from a petrol enginepercentage by volume from a diesel engine nitrogen 72.00 67.00 carbon dioxide 14.00 water vapour 12.00 11.00 carbon monoxide 1.50 0.05 oxides of nitrogen 0.25 0.70 hydrocarbons 0.24 0.22 sulfur dioxide 0.01 0.03 oxygen 0.00 9.00 total 100.00 total 100.00  (i)  in the diesel engine, nitrogen, carbon dioxide and water vapour account for 90.00% of the exhaust gases by volume.   calculate the percentage by volume of carbon dioxide in the exhaust gases from the  diesel engine.  ..%  [1]  (ii)  describe three ways in which the composition of the exhaust gases from the petrol engine  differ from the composition of the exhaust gases from the diesel engine.  1  ..  2  ..  3  ..  [3]  (iii)  give one adverse effect of sulfur dioxide on health.   ...   [1]",
            "5": "5 0620/33/m/j/18 \u00a9 ucles 2018 [turn over  (b)  complete the sentences about the separation of petroleum into fractions using words from the  list. boiling      crystallisation      density      distillation      kerosene      poly(ethene)   fractional .. of petroleum produces fractions such as gasoline, diesel oil  and ... . within each fraction, the molecules have a particular range of     .. points.  [3]  (c)  balance the chemical equation for the complete combustion of propane. c 3h8  +  5o2    .co2  +  .h2o  [2]  [total: 10]",
            "6": "6 0620/33/m/j/18 \u00a9 ucles 2018 3  this question is about cobalt and its compounds.  (a)  a coloured crystal of cobalt( ii) chloride was placed at the bottom of a beaker containing water.   after 2 days, the colour had spread throughout the water. at the start after 2 hours after 2 dayscrystal of cobalt( ii) chloridewater   explain these observations using the kinetic particle model.               ..   [3]  (b)  cobalt( ii) chloride can be used to test for the presence of water. cocl 2    +    6h2o        cocl 2.6h2o  anhydrous hydrated  cobalt(ii) chloride cobalt(ii) chloride  (i)  what is meant by the symbol ?   ...   [1]  (ii)  describe how the colour of anhydrous cobalt( ii) chloride changes when water is added to it.  from . to  ..  [2]  (c)  a compound of cobalt can be represented by the structure shown. = cobalt, co = carbon, c= oxygen, okey   deduce the molecular formula of this compound showing the number of cobalt, carbon and  oxygen atoms.   ..   [1]",
            "7": "7 0620/33/m/j/18 \u00a9 ucles 2018 [turn over  (d)  the table compares the reactivity of cobalt with that of three other metals. metal reactivity with cold water reactivity with steam barium reacts rapidly cobalt no reaction reacts slowly when heated magnesium reacts very slowly reacts rapidly zinc no reaction reacts easily when heated   use this information to put the metals in order of their reactivity. put the least reactive metal  first. least reactive most reactive  [2]  (e)  cobalt is a transition element. lithium is an element in group i of the periodic table.   describe three ways in which the properties of cobalt differ from those of lithium.  1  .  2  .  3  .  [2] (f)  when cobalt( ii) oxide, coo, is heated in air, an oxide with the formula co3o4 is formed.   balance the chemical equation for this reaction. .coo  +  o2    2co3o4  [1]  (g)  when co3o4 is heated with hydrogen, cobalt metal can be formed. co3o4  +  4h2    3co  +  4h2o   how does this equation show that co3o4 is reduced?      ..   [1]  [total: 13]",
            "8": "8 0620/33/m/j/18 \u00a9 ucles 2018 4  this question is about alcohols.  (a)  the structure of compound p is shown. coh hcch h h h  (i)  what feature of the structure of compound p shows that it is unsaturated?   ...   [1]  (ii)  describe how the colour of aqueous bromine changes when an excess of compound p is  added to it.  from . to  ..  [2]  (iii)  the melting point of compound p is \u2013129 \u00b0c.   the boiling point of compound p is 97 \u00b0c.   what is the physical state of compound p at \u2013120 \u00b0c?   explain your answer.   .   ...   [2]  (b)  ethanol is an alcohol with two carbon atoms.  (i)  draw the structure of ethanol showing all of the atoms and all of the bonds.  [1]",
            "9": "9 0620/33/m/j/18 \u00a9 ucles 2018 [turn over  (ii)  ethanol can be manufactured by fermentation.   complete the sentences about fermentation using words from the list.  30 \u00b0c 300 \u00b0c distillation electrolysis  elements enzymes salt sugar \t \ta\tflask\tcontaining\t ..\t solution\tand\tyeast\tis\theated\tto\t..\t .   the yeast contains .. which catalyse the reaction. the ethanol is     separated by .. . [4]  (iii)  ethanol can be used as a fuel.   give one other use of ethanol in industry.   ...   [1]  (iv)  the energy level diagram for the complete combustion of ethanol is shown. energyethanol  +  oxygen carbon dioxide  +  wate r progress of reaction   explain how this diagram shows that the reaction is exothermic.   .   ...   [1]  (v)  carbon dioxide and water can be formed when ethanol burns in a limited supply of air.   state the name of two other products which can be formed when ethanol burns in a limited  supply of air.  . and    [2]  [total: 14]",
            "10": "10 0620/33/m/j/18 \u00a9 ucles 2018 5 (a)  molten lead( ii) bromide can be electrolysed using the apparatus shown. molten lead( ii) bromid einert electrodes+\u2013   the negative electrode is called the cathode.   state the name of the positive electrode.   ..   [1]  (b)  predict the products of the electrolysis of molten lead( ii) bromide at:  the negative electrode  ...  the positive electrode.    [2]  (c)  lead( ii) bromide is insoluble in cold water.   sodium bromide is soluble in cold water.   describe how you could obtain crystals of sodium bromide from a mixture of solid lead( ii) bromide  and solid sodium bromide.            ..   [3]  (d)  when chlorine is bubbled through a colourless aqueous solution of sodium bromide, the  solution turns orange-brown.   name the orange-brown substance. suggest, using ideas about reactivity of the halogens,  why the reaction occurs.  orange-brown substance  ...  why the reaction occurs  .     [2]",
            "11": "11 0620/33/m/j/18 \u00a9 ucles 2018 [turn over  (e)  what is the colour of the precipitate formed when aqueous silver nitrate is added to aqueous  sodium bromide?   ..   [1]  (f)  complete the sentence about the formation of a chloride ion from a chlorine atom.   a chloride ion is formed when a chlorine atom gains one .. . [1]  [total: 10]",
            "12": "12 0620/33/m/j/18 \u00a9 ucles 2018 6  this question is about isotopes.  (a)  an atom of an isotope of oxygen is represented by the symbol shown. 17o8   describe the structure of an atom of this isotope of oxygen.   in your answer, include:  \u25cf the position of the protons, neutrons and electrons in the atom  \u25cf the number of protons, neutrons and electrons present in the atom.                     ..   [5]  (b)  which two statements about isotopes are correct?   tick two boxes.  isotopes of the same element have different numbers of protons.  isotopes of the same element have different numbers of neutrons.  isotopes are always radioactive.  the isotope 235u92 is a source of energy.  14c6 and 14n7 are isotopes of each other.  [2]  (c)  what is meant by the term nucleon number ?      ..   [1]  [total: 8]",
            "13": "13 0620/33/m/j/18 \u00a9 ucles 2018 [turn over 7  this question is about group i elements and their compounds.  (a)  the properties of some group i elements are shown in the table. elementmelting point / \u00b0crelative  hardnessobservations when it reacts with cold water lithium 181 23 sodium 98 3 rapid bubbling but does not\tburst\tinto\tflame potassium 63 very\trapid\tbubbling\tand\tbursts\tinto\tflame rubidium 1 bursts\tinto\tflame\tand\texplodes  (i)  complete the table to estimate:  \u25cf the relative hardness of potassium  \u25cf the melting point of rubidium.  [2]  (ii)  use the information in the table to predict what you would observe when lithium reacts with  cold water.   ...   [1]  (b)  write the electronic structure of a sodium atom.   ..   [1]  (c)  when sodium reacts with water, an alkaline solution is formed. 2na  +  2h2o    2naoh  +  h2  (i)  use the information in the equation to explain why the solution formed is alkaline.   ...   [1]  (ii)  describe how you could use a named indicator solution to show that the solution is alkaline.   .   ...   [2]",
            "14": "14 0620/33/m/j/18 \u00a9 ucles 2018  (d)  sodium tetrahydridoborate, nabh4, is an ionic compound.   calculate the relative formula mass of nabh4.   show all your working.   use your periodic table to help you.  relative formula mass = .  [2]  [total: 9]",
            "15": "15 0620/33/m/j/18 \u00a9 ucles 2018 [turn over 8  the apparatus shown is used to investigate the rate of reaction between calcium carbonate and  hydrochloric acid at 30 \u00b0c. water hydrochloric acida calcium carbonate  (a)  name the piece of apparatus labelled a in the diagram.   ..   [1]  (b)\t\tdescribe\thow\tthis\tapparatus\tcan\tbe\tused\tto\tfind\tthe \trate\tof\treaction.         ..   [2]  (c)  the experiment is repeated at 20 \u00b0c. all other conditions are kept the same.   how does the decrease in temperature affect the rate of reaction?   ..   [1]  (d)  the experiment is repeated using the same mass of different size pieces of calcium carbonate.  all other conditions are kept the same.   the sizes of the pieces of calcium carbonate are:  \u25cflarge pieces  \u25cfsmall pieces  \u25cfpowder \t \tcomplete\tthe\ttable\tby\twriting\tthe\tsizes\tof\tthe\tpieces\tin\tthe\tfirst\tcolumn. size of the pieces of calcium carbonateinitial rate of reaction in cm3 gas / s 5 2 12  [1]",
            "16": "16 0620/33/m/j/18 \u00a9 ucles 2018  (e)  give the names of the three products formed when calcium carbonate reacts with  hydrochloric acid.  1  .  2  .  3  .  [2]  [total: 7]",
            "17": "17 0620/33/m/j/18 \u00a9 ucles 2018blank page",
            "18": "18 0620/33/m/j/18 \u00a9 ucles 2018blank page",
            "19": "19 0620/33/m/j/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.",
            "20": "20 0620/33/m/j/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s18_qp_41.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/41 paper 4  theory (extended) may/june 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 12 printed pages. [turn overib18 06_0620_41/5rp\u00a9 ucles 2018 *2711517754* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/41/m/j/18 \u00a9 ucles 2018 1\t\tsubstances\tcan\tbe\tclassified\tas\telements,\tcompounds\tor\tmixtures.  (a)\t\twhat\tis\tmeant\tby\tthe\tterm\tcompound  ?  \t  \t  \t..   [2]  (b)\t\tmixtures\tcan\tbe\tseparated\tby\tphysical\tprocesses. \t\ta\tsequence\t of\tphysical\tprocesses\t can\tbe\tused\tto\tseparate\tcommon\tsalt\t(sodium\tchloride)\t from\ta\tmixture\tcontaining\tsand\tand\tcommon\tsalt\tonly. \t\tgive\tthe\torder\tand\tthe\tcorrect\tscientific\tterm\tfor\tthe\tphysical\tprocesses\t used\tto\tseparate\tthe\t common\tsalt\tfrom\tthe\tmixture.  1 \t.  2 \t.  3 \t.  [4] \t\tthe\tboiling\tpoints\tof\tfour\tdifferent\talcohols,\t a,\tb,\tc\tand\td,\tare\tshown. alcohol a b c d boiling\tpoint\t /\t\u00b0c 56 78 122 160  (c)\t\ta\tstudent\tsuggested\t that\tthe\tapparatus\t shown\tcould\tbe\tused\tto\tseparate\tthe\tmixture\tof\t alcohols. mixture of alcoholsa, b, c and dxfractionating colum n hot water electric heater",
            "3": "3 0620/41/m/j/18 \u00a9 ucles 2018 [turn over  (i)\t\tapparatus\tx\tneeds\tto\thave\tcold\twater\tflowing\tthrough\tit. \t \u25cf\t\tdraw\tan\tarrow\ton\tthe\tdiagram\tto\tshow\twhere\tthe\tcold\twater\tenters\tapparatus\t x. \t \u25cf\t\tname\tapparatus\tx.  \t .  [2]  (ii)\t\tpart\tof\tthe\tfractionating\tcolumn\tis\tmissing.\t this\tmeans\tthat\tthe\texperiment\twill\tnot\twork. \t \u25cf\t\tdraw\ton\tthe\tdiagram\tthe\tpart\tof\tthe\tfractionating\tcolumn\twhich\tis\tmissing. \t \u25cf\t\texplain\twhy\tthe\texperiment\t will\tnot\twork\twith\tthis\tpart\tof\tthe\tfractionating\t column\t missing.  \t .  \t .  [2]  (iii)\t\tsuggest\twhy\ta\tbunsen\tburner\tis\t not\tused\tto\theat\tthe\tflask.  \t ...   [1]  (iv)\t\ta\thot\twater\tbath\tcannot\tbe\tused\tto\tseparate\talcohols\t c\tand\td. \t \texplain\twhy.  \t .  \t .  \t ...   [2] \t [total:\t13]",
            "4": "4 0620/41/m/j/18 \u00a9 ucles 2018 2\t\tflerovium,\tfl,\tatomic\tnumber\t114,\twas\tfirst\tmade\tin\tresearch\tlaboratories\tin\t1998.  (a)\t\tflerovium\t was\tmade\tby\tbombarding\t atoms\tof\tplutonium,\t pu,\tatomic\tnumber\t94,\twith\tatoms\tof\t element\tz.  \u25cf\tthe\tnucleus\tof\tone\tatom\tof\tplutonium\t combined\t with\tthe\tnucleus\tof\tone\tatom\tof\telement\t z.\t  \u25cf\tthis\tformed\tthe\tnucleus\tof\tone\tatom\tof\tflerovium. \t\tsuggest\tthe\tidentity\tof\telement\t z.  \t..   [1]  (b)\t\tin\twhich\tperiod\tof\tthe\tperiodic\t table\tis\tflerovium?  \t..   [1]  (c)\t\tpredict\tthe\tnumber\tof\touter\tshell\telectrons\tin\tan\tatom\tof\tflerovium.  \t..   [1]  (d)\t\ttwo\tisotopes\tof\tflerovium\tare\t286fl\tand\t289fl.\tthe\tnuclei\tof\tboth\tof\tthese\tisotopes\tare\tunstable\t and\temit\tenergy\twhen\tthey\tsplit\tup.  (i)\t\tstate\tthe\tterm\tused\tto\tdescribe\tisotopes \twith\tunstable\tnuclei.  \t ...   [1]  (ii)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\tprotons,\tneutrons\tand\telectrons\tin\tthe\tatoms\tof\t the\tisotopes\tshown. isotope number\tof\tprotons number\tof\tneutrons number\tof\telectrons 286fl 289fl  [2]  (e)\t\tonly\ta\trelatively\tsmall\tnumber\tof\tatoms\tof\tflerovium\thave\tbeen\tmade\tin\tthe\tlaboratory\t and\tthe\t properties\tof\tflerovium\thave\tnot\tyet\tbeen\tinvestigated. \t\tit\thas\tbeen\tsuggested\tthat\tflerovium\tis\ta\ttypical\tmetal.  (i)\t\tsuggest\ttwo\tphysical\tproperties\tof\tflerovium.  1 \t ..  2 \t ..  [2]  (ii)\t\tsuggest\tone\tchemical\tproperty\tof\tflerovium\toxide.  \t ...   [1] \t [total:\t9]",
            "5": "5 0620/41/m/j/18 \u00a9 ucles 2018 [turn over 3\t\tthis\tquestion\tis\tabout\tiron.  (a)\t\tthree\tof\tthe\traw\tmaterials\t added\tto\ta\tblast\tfurnace\tused\tto\textract\tiron\tfrom\thematite\tare\t coke,\thematite\tand\tlimestone. \t\tname\tone\tother\traw\tmaterial\tadded\tto\tthe\tblast\tfurnace.  \t..   [1]  (b)\t\ta\tseries\tof\treactions\toccurs\tin\ta\tblast\tfurnace\tduring\tthe\textraction\tof\tiron\tfrom\thematite. \t\tdescribe\tthese\treactions. \t\tinclude:  \u25cfone\tchemical\tequation\tfor\tthe\treduction\tof\thematite  \u25cfone\tchemical\tequation\tfor\tthe\tformation\tof\tslag.  \t  \t  \t  \t  \t  \t  \t  \t..   [5]  (c)\t\tthe\tiron\textracted\tfrom\thematite\tusing\ta\tblast\tfurnace\tis\timpure. \t\tidentify\tthe\tmain\timpurity\tin\tthis\tiron\tand\texplain\thow\tit\tis\tremoved\tin\tthe\tsteel\u2011making\t process. \t main\timpurity\t \t. \t how\tit\tis\tremoved\t \t...  \t  \t  [3] \t [total:\t9]",
            "6": "6 0620/41/m/j/18 \u00a9 ucles 2018 4\t\tthis\tquestion\tis\tabout\tmasses,\tvolumes\tand\tmoles.  (a)\t\twhich\tterm\tis\tdefined\tby\tthe\tfollowing\tstatement? the average mass of naturally occurring atoms of an element on a scale where the 12c atom has a mass of exactly 12 units.  \t..   [1]  (b)\t\tbutane,\tc4h10,\thas\ta\trelative\tmolecular\tmass\tof\t58. \t\tpotassium\tfluoride,\tkf,\thas\ta\trelative\tformula\tmass\tof\t58. \t\texplain\twhy\tthe\tterm\trelative\tmolecular\t mass\tcan\tbe\tused\tfor\tbutane\tbut\tcannot\tbe\tused\tfor\t potassium\tfluoride.  \t  \t..   [2]  (c)\t\ta\t0.095\tg\tsample\tof\tgaseous\telement\t y\toccupies\t60.0\tcm3\tat\troom\ttemperature\t and\tpressure.  \u25cf\tdetermine\tthe\tnumber\tof\tmoles\tof\telement\t y\tin\t60.0\tcm3. \t moles\tof\telement\t y\t=\t.\tmol  \u25cf\tcalculate\t the\trelative\tmolecular\t mass\tof\telement\t y\tand\thence\tsuggest\tthe\tidentity\tof\t element\ty. \t relative\tmolecular\tmass\t=\t. \t identity\tof\telement\ty\t=\t.  [3]",
            "7": "7 0620/41/m/j/18 \u00a9 ucles 2018 [turn over  (d)\t\ta\t1.68\tg\tsample\tof\tphosphorus\twas\tburned\tand\tformed\t3.87\t g\tof\tan\toxide\tof\tphosphorus. \t\tcalculate\tthe\tempirical\tformula\tof\tthis\toxide\tof\tphosphorus. \t empirical\tformula\t=\t.\t\t[4]  (e)\t\tanother\toxide\tof\tphosphorus\thas\tthe\tempirical\tformula\tp2o3. \t\tone\tmolecule\tof\tthis\toxide\tof\tphosphorus\tcontains\tfour\tatoms\tof\tphosphorus. \t\tcalculate\tthe\tmass\tof\t one\tmole\tof\tthis\toxide\tof\tphosphorus. \t mass\t=\t.\tg\t\t[2] \t [total:\t12]",
            "8": "8 0620/41/m/j/18 \u00a9 ucles 2018 5 (a)\t\tthe\ttable\tgives\tsome\tchemical\tproperties\t of\ttransition\telements\tand\ttheir\tcompounds,\t and\tof\t group\ti\telements\tand\ttheir\tcompounds. chemical\tproperty transition\telements group\ti\telements ability\tto\tact\tas\tcatalysts yes no exist\tas\tcoloured\tcompounds yes no  (i)\t\twhat\tis\tmeant\tby\tthe\tterm\tcatalyst?  \t .  \t .  \t ...   [2]  (ii)  give one\tother\tchemical\tproperty\tshown\tby\ttransition\t elements\t which\tis\tnot\tshown\tby\t group\ti\telements.  \t ...   [1]  (b)  give two\tphysical\tproperties\t shown\tby\ttransition\t elements\t which\tare\tnot\tshown\tby\tgroup\ti\t elements.  1 \t.  2 \t.  [2]  (c)\t\tthe\tenergy\tlevel\tdiagram\tshows\tthe\tenergy\tprofile\tfor\tthe\treaction\tbetween\tzinc\tand\tdilute\t sulfuric\tacid. energy progress of reactionzn(s)  +  h2so4(aq)  (i)\t\tcomplete\tthe\tdiagram\tby\tadding\tthe\tformulae\tof\tthe\tproducts.\tinclude\tstate\tsymbols.\t [3]  (ii)\t\tdraw\tan\tarrow\ton\tthe\tdiagram\tto\trepresent\tthe\tactivation\tenergy.\t [1]  (iii)\t\tis\tthe\treaction\tendothermic\tor\texothermic?\texplain\tyour\tanswer.  \t .  \t ...   [1]",
            "9": "9 0620/41/m/j/18 \u00a9 ucles 2018 [turn over  (d)\t\tthe\treaction\tbetween\tzinc\tand\tdilute\tsulfuric\tacid\tcan\tbe\tcatalysed\t by\tthe\taddition\tof\taqueous\t copper( ii)\tsulfate. \t\ton\tthe\tdiagram,\tadd\tthe\tenergy\tprofile\tfor\tthe\tcatalysed\treaction. energy progress of reactionzn(s)  +  h2so4(aq)  [1]  (e)\t\ta\tstudent\telectrolyses\taqueous\tcopper( ii)\tsulfate\tusing\tthe\tapparatus\tshown. + \u2013 carbon electrode s aqueou s copper (ii) sulfatepower supply \t\toxygen\tgas\tforms\tat\tthe\tpositive\telectrode\t(anode).  (i)\t\twrite\tan\tionic\thalf\u2011equation\t for\tthe\treaction\tat\tthe\tnegative\telectrode\t (cathode).\t include\t state\tsymbols.  \t ...   [3]  (ii)\t\tdescribe\twhat\tthe\tstudent\tobserves\tat\tthe\tnegative\telectrode.  \t ...   [1]  (iii)  give two other\tobservations\twhich\tthe\t student\tmakes\tduring\tthe\telectrolysis.  1 \t ..  2 \t ..  [2]  (iv)\t\twhat\tdifference\t would\tthe\tstudent\tobserve\tat\tthe\tpositive\telectrode\t if\tthe\taqueous\t copper( ii)\tsulfate\twere\treplaced\tby\tconcentrated\taqueous\tcopper( ii)\tchloride?  \t ...   [1] \t [total:\t18]",
            "10": "10 0620/41/m/j/18 \u00a9 ucles 2018 6\t\tthe\ttable\tshows\tthe\tstructures\tof\tfour\thydrocarbons. p q r s ch3\u2013ch3 ch2=ch2 ch2=ch\u2013ch3 ch2=ch\u2013ch2\u2013ch3  (a)\t\twhy\tare\tcompounds\t p,\tq,\tr\tand\ts\tknown\tas\thydrocarbons?  \t  \t..   [2]  (b)\t\tcompound\t p\tis\tsaturated. \t\twhat\tis\tmeant\tby\tthe\tterm\tsaturated ?  \t  \t..   [1]  (c)\t\tcompound\t p\tundergoes\ta\tsubstitution\treaction\twith\tchlorine.  (i)\t\twhat\tis\tmeant\tby\tthe\tterm\tsubstitution reaction ?  \t .  \t ...   [1]  (ii)\t\tstate\ta\tcondition\trequired\tfor\tthis\treaction\tto\toccur.  \t ...   [1]  (iii)\t\twrite\ta\tchemical\tequation\tfor\tthis\treaction.  \t ...   [2]  (d)\t\tcompound\t r\tundergoes\tan\taddition\treaction\twith\tbromine.  (i)\t\twhy\tis\tthis\treaction\tan\taddition\treaction?  \t ...   [1]  (ii)\t\ta\tcompound\tcontaining\tbromine\tis\tformed\tin\tthis\treaction. \t \tdraw\tthe\tstructure\tof\tthis\tcompound.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [1]",
            "11": "11 0620/41/m/j/18 \u00a9 ucles 2018to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series.  (e)\t\tdraw\tthe\tstructure\tof\tan\tunbranched\t isomer\tof\tcompound\t s.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\t the\tbonds.\tname\tthis\tunbranched\tisomer\tof\tcompound\t s. \t structure \t name\t\t ..  [2]  (f)\t\tcompound\t q\tundergoes\tpolymerisation.  (i)\t\tname\tthe\tpolymer\tformed.  \t ...   [1]  (ii)\t\tcomplete\tthe\tchemical\tequation\tto\tshow \tthe\tpolymerisation\tof\tcompound\t q.  n ch2=ch2                [2]  (g)\t\tamino\tacids\tundergo\tpolymerisation\t to\tform\tproteins.\tpart\tof\ta\tprotein\tmolecule\t with\tthe\t linkages\tmissing\tis\tshown. \t\tdraw\tthe\tlinkages\ton\tthe\tdiagram.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds. nh co  [2]  (h)\t\tthe\tstructure\tshows\tan\tester. ch2co och2 ch3 ch2ch3 \t\twrite\tthe\tword\tequation\tfor\ta\treaction\twhich\tcould\tbe\tused\tto\tmake\tthis\tester.  \t..   [3] \t [total:\t19]",
            "12": "12 0620/41/m/j/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s18_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used. a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/42   paper 4  theory (extended) may/june 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 11  printed pages and 1 blank page. [turn overib18 06_0620_42/3rp\u00a9 ucles 2018 *0107966450* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/m/j/18 \u00a9 ucles 2018 1  give the name of the process that is used:  (a)  to obtain water from aqueous sodium chloride   ..   [1]  (b)  to produce lead from molten lead( ii) bromide   ..   [1]  (c)  to separate an insoluble solid from a liquid   ..   [1]  (d)  to separate the components of petroleum   ..   [1]  (e)  to separate a mixture of coloured dyes.   ..   [1] [total: 5]",
            "3": "3 0620/42/m/j/18 \u00a9 ucles 2018 [turn over 2  this question is about the elements in period 3 of the periodic table. na mg al si p s cl ar   for each of the following, identify a period 3 element which matches the description. each element  may be used once, more than once or not at all.   state which period 3 element:  (a)  forms an oxide with a macromolecular structure   ..   [1]  (b)  is extracted from the ore bauxite   ..   [1]  (c)  is soft, metallic and stored in oil   ..   [1]  (d)  is a green gas at room temperature and pressure   ..   [1]  (e)  provides an inert atmosphere in lamps   ..   [1]  (f)  forms two different oxides during the contact process   ..   [1]  (g)  is non\u2011metallic and an important component of fertilisers.   ..   [1] [total: 7] 3  complete the following table. particlenumber of protonsnumber of electronsnumber of neutronsnumber of nucleons 11na2311 1123 17cl \u2013 37  20 2656 .26 24 30 56 [6] [total: 6]",
            "4": "4 0620/42/m/j/18 \u00a9 ucles 2018 4  potassium reacts with bromine at room temperature to form potassium bromide.  (a)  write a chemical equation for this reaction. include state symbols.   ..   [3]  (b)  potassium bromide exists as an ionic lattice.   potassium bromide does not conduct electricity when solid but does conduct electricity when  molten.  (i)  what is meant by the term ionic lattice ?   .   ...   [2]  (ii)  explain why potassium bromide does not conduct electricity when solid but does conduct  electricity when molten.   .   .   ...   [2]  (c)  concentrated aqueous potassium bromide is an electrolyte.  (i)  what is meant by the term electrolyte ?   .   ...   [2]  (ii)  describe the electrolysis of concentrated aqueous potassium bromide.   include:  \u25cfan ionic half\u2011equation for the reaction at the cathode  \u25cfthe name of the product at the anode  \u25cfthe name of the potassium compound formed.   .   .   .   ...   [4]  (iii)  when molten potassium bromide is electrolysed, the product at the cathode is different.   name the product at the cathode when molten potassium bromide is electrolysed.   ...   [1]",
            "5": "5 0620/42/m/j/18 \u00a9 ucles 2018 [turn over  (d)  iodine reacts with chlorine to form iodine monochloride, icl, as the only product.  (i)  write a chemical equation for this reaction.   ...   [2]  (ii)  draw a dot\u2011and\u2011cross diagram to show the electron arrangement in a molecule of  iodine monochloride. show outer shell electrons only. [2]  (e)  potassium bromide has a melting point of 734 \u00b0c.   iodine monochloride has a melting point of 27 \u00b0c.   in terms of attractive forces, explain why there is a large difference between these melting points.               ..   [3]  (f)  when chlorine gas is passed through aqueous potassium bromide, a redox reaction occurs. the ionic equation is shown. cl  2  +  2br \u2013    2cl \u2013  +  br2  (i)  write an ionic half\u2011equation showing what happens to the chlorine molecules, cl 2, in this  reaction.   ...   [1]  (ii)  explain why the bromide ions, br \u2013, act as reducing agents in this reaction.   ...   [1] [total: 23]",
            "6": "6 0620/42/m/j/18 \u00a9 ucles 2018 5  hydrogen and iodine react together in a reversible reaction. hydrogen iodide is formed. h2(g)  +  i2(g)    2hi(g)  colourless purple colourless  gas gas gas   the forward reaction is exothermic.   a gas syringe containing an equilibrium mixture of hydrogen, iodine and hydrogen iodide gases  was sealed and heated to 250 \u00b0c. the equilibrium mixture was a pale purple colour. end blockedequilibrium mixture of hydrogen , iodine and hydrogen iodide  (a)  what is meant by the term equilibrium ?         ..   [2]  (b)  the plunger of the gas syringe was pressed in while the end of the gas syringe was blocked. this increased the pressure. the position of the equilibrium did not change. the colour of the  gaseous mixture turned darker purple.  (i)  give a reason why the position of the equilibrium did not change.   ...   [1]  (ii)  suggest why the gaseous mixture turned darker purple, even though the position of the equilibrium did not change.   ...   [1]  (c)  the temperature of the gas syringe was increased to 300 \u00b0c.  (i)  what happened to the position  of the equilibrium when the temperature of the gas syringe  was increased from 250 \u00b0c to 300 \u00b0c?   ...   [1]  (ii)  what happened to the rate of the forward reaction and the rate of the backward reaction  when the temperature of the gas syringe was increased from 250 \u00b0c to 300 \u00b0c?  rate of the forward reaction  .  rate of the backward reaction  . [2] [total: 7]",
            "7": "7 0620/42/m/j/18 \u00a9 ucles 2018 [turn over 6 (a)  all sodium salts are soluble in water. all nitrates are soluble in water. barium carbonate is  insoluble in water.   describe how you would make a pure, dry sample of barium carbonate by precipitation.   include:  \u25cf the names of the starting materials  \u25cf full practical details  \u25cf a chemical equation.                  ..   [5]  (b)  nitrates decompose when heated.  (i)  write a chemical equation for the decomposition of sodium nitrate when it is heated.   ...   [2]  (ii)  the unbalanced chemical equation for the decomposition of hydrated copper( ii) nitrate  crystals is shown.   balance the chemical equation for this reaction. 2cu(no3)2.3h2o(s)    .cuo(s)  +  ..no2(g)  +  o2(g)  +  ..h2o(g) [2]  (iii)  when the hydrated copper( ii) nitrate crystals are heated, steam is produced. when the  steam condenses on a cool surface, it turns into a colourless liquid.   anhydrous cobalt( ii) chloride is used to show that the colourless liquid contains water.   how does the colour of the anhydrous cobalt( ii) chloride change?  from ...  to  ...  [2]  (iv)  how would the student test to determine if the water produced in (b)(iii)  is pure?   ...   [1] [total: 12]",
            "8": "8 0620/42/m/j/18 \u00a9 ucles 2018 7  many organic compounds, such as alcohols, carboxylic acids and esters, contain the elements   carbon, hydrogen and oxygen only.  (a)  compound r has the following composition by mass: c, 60.00%; h, 13.33%; o, 26.67%.   calculate the empirical formula of compound r.  empirical formula = ..  [2]  (b)  compound s has the empirical formula c2h4o and a relative molecular mass of 88.   calculate the molecular formula of compound s. molecular formula = ..  [2]",
            "9": "9 0620/42/m/j/18 \u00a9 ucles 2018 [turn over  (c)  compounds t and v both have the molecular formula c3h6o2.  \u25cf compound t produces bubbles of carbon dioxide gas when it is added to aqueous  sodium carbonate.  \u25cf compound v is an ester.  (i)  what is the name given to compounds with the same molecular formula but different  structures?   ...   [1]  (ii)  draw the structures of compounds t and v. show all of the atoms and all of the bonds.  compound t  compound v [2]  (iii)  all compounds with the molecular formula c3h6o2 can undergo complete combustion in  an excess of oxygen.   complete the chemical equation for this reaction. c3h6o2  +        +   [2]  (d)  compound w has the molecular formula c2h6o. compound w reacts when heated with  ethanoic acid and a catalyst to produce a sweet\u2011smelling liquid.  (i)  give the name of the homologous series to which compound w belongs.   ...   [1]  (ii)  draw the structure of compound w. show all of the atoms and all of the bonds.  [1]",
            "10": "10 0620/42/m/j/18 \u00a9 ucles 2018  (e)  alkanes and alkenes are hydrocarbons.  (i)  what is meant by the term hydrocarbon ?   .   ...   [2]  (ii)  state the general formula of:  alkanes  ...  alkenes  ... [2]  (f)  ethanol can be produced from long\u2011chain alkanes as shown.  step 1 step 2 long\u2011chain alkane    ethene    ethanol   describe the two\u2011stage manufacture of ethanol from the long\u2011chain alkane octane, c8h18.   include:  \u25cf the names of the types of chemical reactions that occur  \u25cf reaction equations  \u25cf reaction conditions.  step 1             step 2           ..   [5] [total: 20]",
            "11": "11 0620/42/m/j/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "12": "12 0620/42/m/j/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s18_qp_43.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/43   paper 4  theory (extended) may/june 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib18 06_0620_43/4rp\u00a9 ucles 2018 *6229193737* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/43/m/j/18 \u00a9 ucles 2018 1  the following are the symbols and formulae of some elements and compounds. ar      ca(oh)2      c l 2      co2      cu      fe      so2      v2o5   answer the following questions using only the elements or compounds in the list.   each element or compound may be used once, more than once or not at all.   state which element or compound is used:  (a)  to kill bacteria in drinking water  ...   [1]  (b)  as a food preservative  .   [1]  (c)  as an electrical conductor in cables  .   [1]  (d)  as an inert atmosphere in lamps  .   [1]  (e)  to neutralise excess acidity in soil  ...   [1]  (f)  as a catalyst in the contact process.  ...   [1] [total: 6]",
            "3": "3 0620/43/m/j/18 \u00a9 ucles 2018 [turn over 2 (a)  29al is a radioactive isotope of aluminium. the only non\u2011radioactive isotope of aluminium is  27al.  (i)  describe, in terms of protons, neutrons and electrons, how the isotopes 29al and 27al are  similar and how they are different.  how they are similar    how they are different  . [2]  (ii)  complete the table to show the number of nucleons, neutrons and electrons in an 13al27 3+  ion. number in 13al27 3+ nucleons neutrons electrons [3]  (b)  aluminium is extracted from its ore by electrolysis.  (i)  name the main ore of aluminium.   ...   [1]  (ii)  why is aluminium not extracted from its ore by reduction with carbon?   ...   [1]  (iii)  the main ore of aluminium contains aluminium oxide. aluminium oxide is dissolved in  molten cryolite before it is electrolysed.   give two reasons, other than cost, why cryolite is used.  1  ..  2  ..  [2]",
            "4": "4 0620/43/m/j/18 \u00a9 ucles 2018  (iv)  the reaction at the anode during the extraction of aluminium by electrolysis is shown. 2o2\u2013    o2  +  4e\u2013   is this process oxidation or reduction?   give a reason for your answer.   ...   [1]  (v)  during the extraction of aluminium by electrolysis, carbon dioxide is formed at the anode.   explain how carbon dioxide is formed at the anode.   .   ...   [2]  (c)  when a piece of zinc metal is added to copper( ii) sulfate solution there is an immediate  reaction. zn  +  cuso4    znso4  +  cu   when a piece of aluminium metal is added to copper( ii) sulfate solution the initial reaction is  very slow.  (i)  explain why zinc metal reacts with copper( ii) sulfate.   ...   [1]  (ii)  what type of reaction is this?   ...   [1]  (iii)  explain why the initial reaction between aluminium metal and copper( ii) sulfate is very  slow.   ...   [1] [total: 15]",
            "5": "5 0620/43/m/j/18 \u00a9 ucles 2018 [turn over 3  cobalt is a transition element. potassium is in group i of the periodic table.  (a)  state one physical property that is similar for cobalt and potassium.   ..   [1]  (b) (i)  state one physical property that is different for cobalt and potassium.   ...   [1]  (ii)  describe how the physical property given in (b)(i) is different for cobalt compared to  potassium.   ...   [1]  (c)\t\twhen\ta\tsmall\tpiece\tof\tpotassium\t is\tadded\tto\tcold\twater,\tthe\tpotassium\t floats\tand\tdisappears\t as it reacts.   give two other observations that would be made when a small piece of potassium is added to  cold water.  1  .  2  . [2]  (d)  cobalt reacts with dilute hydrochloric acid to make the salt cobalt( ii) chloride. bubbles of  hydrogen gas are produced.  (i)  describe a test for hydrogen.  test  ..  result  ...  [2]  (ii)  the rate of reaction of cobalt with dilute hydrochloric acid can be made faster by heating  the acid or by increasing its concentration.   state one other way to make the rate of reaction faster.   ...   [1]  (iii)  use collision theory to explain how heating the dilute hydrochloric acid makes the rate of  reaction faster.   .   .   .   .   ...   [3]",
            "6": "6 0620/43/m/j/18 \u00a9 ucles 2018  (e)  when cobalt( ii) chloride is added to water an equilibrium is established. [cocl 4]2\u2013  +  6h2o    [co(h2o)6]2+  +  4cl \u2013  blue pink  (i)  a student adds water to a blue solution containing [coc l 4]2\u2013 ions.   describe what the student observes. give a reason for your answer in terms of the position  of the equilibrium.   .   .   ...   [2]  (ii)  another student cools a blue solution containing [coc l 4]2\u2013. the blue solution turns pink.   what does this information indicate about the forward reaction?   .   ...   [1]  (f)  another compound of cobalt is co(oh)3.   deduce the charge on the cobalt ion in co(oh)3.   ..   [1] [total: 15]",
            "7": "7 0620/43/m/j/18 \u00a9 ucles 2018 [turn over 4  ethanol is a member of the homologous series of alcohols.  (a)  give two characteristics of members of a homologous series.  1  .  2  .  [2]  (b)  the structure of ethanol is shown. chh ochh hh   complete the dot\u2011and\u2011cross diagram to show the electron arrangement in a molecule of  ethanol. show outer shell electrons only. c hh o chh hh [2]  (c)  ethanol can be produced by the catalytic addition of steam to ethene or by the fermentation of  glucose.  (i)  write a chemical equation for the production of ethanol by the catalytic addition of steam to ethene.   ...   [1]  (ii)  write a chemical equation for the production of ethanol by the fermentation of glucose,  c 6h12o6.   ...   [1]  (iii)  state one advantage of producing ethanol by the catalytic addition of steam to ethene.   your answer must not refer to cost.   ...   [1]  (iv)   state one advantage of producing ethanol by the fermentation of glucose.   your answer must not refer to cost.   ...   [1]",
            "8": "8 0620/43/m/j/18 \u00a9 ucles 2018  (d)  ethanol can be oxidised to ethanoic acid.   state the chemical reagent needed to oxidise ethanol to ethanoic acid.   ..   [1]  (e)  ethanoic acid reacts with ethanol in the presence of an acid catalyst. the products are an  organic compound and water.  (i)  draw the structure of the organic compound formed. show all of the atoms and all of the bonds. [2]  (ii)  state the name of the organic compound formed.   ...   [1]  (iii)  which homologous series does the organic compound formed belong to?   ...   [1]  (f)  ethanoic acid, ch 3cooh, is a weak acid. it reacts with copper( ii) carbonate to form the salt  copper( ii) ethanoate, cu(ch3coo)2.   (i)  what is meant by the term weak when applied to acids?   ...   [1]  (ii)  describe how a crystalline sample of copper( ii) ethanoate can be prepared starting with  ethanoic acid and copper( ii) carbonate.   .   .   .   .   .   ...   [3]  (iii)  write the word equation for the reaction between ethanoic acid and copper( ii) carbonate.   ...   [1] [total: 18]",
            "9": "9 0620/43/m/j/18 \u00a9 ucles 2018 [turn over 5 (a)  nickel( ii) iodide crystals are hydrated. a sample of hydrated nickel( ii) iodide crystals has the  following composition by mass: ni, 14.01%;  i, 60.33%;  h, 2.85%;  o, 22.81%.   calculate the empirical formula of the hydrated nickel( ii) iodide crystals.  empirical formula = ..  [2]  (b)  molten nickel( ii) iodide can be electrolysed using the apparatus shown. copper wirespower supply platinum electrodes molten nickel( ii) iodid e   during electrolysis, charge is transferred through the copper wires and through the molten  nickel( ii) iodide.  (i)  name the type of particles which transfer charge through the copper wires.   ...   [1]  (ii)  name the type of particles which transfer charge through the molten nickel( ii) iodide.   ...   [1]  (iii)  predict the products of the electrolysis of molten nickel( ii) iodide. write an ionic   half\u2011equation for the formation of one of these products.  products ...  ionic half\u2011equation  ..  [3]",
            "10": "10 0620/43/m/j/18 \u00a9 ucles 2018  (c)  a student electrolysed copper( ii) sulfate solution using the two sets of apparatus shown. apparatus acarbon electrodes copper( ii) sulfate solutio n apparatus  bcoppe r electrodescopper( ii) sulfat e solutio npower supply power supply   in apparatus a the student used carbon electrodes.   in apparatus b the student used copper electrodes.   the student made the following observations. apparatus a apparatus b the mass of the negative electrode increased. the mass of the negative electrode increased. the mass of the positive electrode stayed the same. the mass of the positive electrode decreased. bubbles were seen at the positive electrode. no bubbles were seen at the positive electrode.  (i)  explain why the mass of the negative electrode increased in both  sets of apparatus.   .   ...   [1]  (ii)  name the gas that formed the bubbles seen in apparatus a.   ...   [1]  (iii)  explain why the mass of the positive electrode decreased in apparatus b.   .   ...   [1]",
            "11": "11 0620/43/m/j/18 \u00a9 ucles 2018 [turn over  (iv)  suggest what happens to the colour of the solution in apparatus a and apparatus b as the  electrolysis progresses.   explain your answer.  colour of the solution in apparatus a  ..  colour of the solution in apparatus b  ..  explanation  .   .   .  [3] [total: 13]",
            "12": "12 0620/43/m/j/18 \u00a9 ucles 2018 6  calcium chlorate( v), ca(cl o3)2, is made by reacting calcium hydroxide with chlorine  gas. 6ca(oh)2  +  6cl 2    ca(cl o3)2  +  5cacl 2  +  6h2o  (a)  8.88 g of calcium hydroxide and 7200 cm3 of chlorine gas are mixed together.  (i)  how many moles is 8.88 g of calcium hydroxide? .. mol  [2]  (ii) how many moles of chlorine gas is 7200  cm3? .. mol  [1]  (iii)  what is the maximum number of moles of calcium chlorate( v) that can be made from  8.88 g of calcium hydroxide and 7200 cm3 of chlorine gas? .. mol  [1]  (iv)  what is the maximum mass  of calcium chlorate( v) that can be made from 8.88 g of  calcium hydroxide and 7200 cm3 of chlorine gas? .. g  [2]   the experiment is repeated using different amounts of calcium hydroxide and chlorine gas.  the maximum mass of calcium chlorate( v) that can be made in the experiment is 4.84 g.  (v)  the actual mass of calcium chlorate( v) made in the experiment is 3.63 g.   calculate the percentage yield. percentage yield = .. %  [1]  (b)  calcium chlorate( v) undergoes thermal decomposition.   the only products are calcium chloride and a colourless gas.  (i)  what must be done to calcium chlorate( v) to make it thermally decompose?   ...   [1]  (ii)  write a chemical equation for the thermal decomposition of calcium chlorate( v).   ...   [2]",
            "13": "13 0620/43/m/j/18 \u00a9 ucles 2018 [turn over  (c)  chloric( v) acid, hcl o3, is a strong acid. it can be made from calcium chlorate( v).  (i)  what colour is methyl orange indicator in chloric( v) acid?   ...   [1]  (ii)\t\tdefine\tthe\tterm\tacid in terms of proton transfer.   ...   [1]  (iii)  complete the chemical equation to show hcl o3 behaving as an acid in water. hcl o3  +  h2o    ...  +  ... [1] [total: 13]",
            "14": "14 0620/43/m/j/18 \u00a9 ucles 2018blank page",
            "15": "15 0620/43/m/j/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "16": "16 0620/43/m/j/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s18_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5  practical test may/june 2018  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 11  printed pages, 1 blank page and 1 insert. [turn overib18 06_0620_51/3rp\u00a9 ucles 2018 *8393780945* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/51/m/j/18 \u00a9 ucles 2018blank page",
            "3": "3 0620/51/m/j/18 \u00a9 ucles 2018 [turn over 1  you are going to investigate the rate of reaction between dilute hydrochloric acid and aqueous  sodium thiosulfate. when these chemicals react they form a precipitate which makes the solution  go cloudy. the formation of this precipitate can be used to show how fast the reaction proceeds.   read all the instructions carefully before starting the experiments.   instructions \t\tyou\tare\tgoing\tto\tdo\tfive\texperiments\tusing\tthe\tapparatus\tshown. aqueous sodium thiosulfat eeye 10 cm3 of dilute hydrochloric acid 250  cm3 conical flas k printed inser t printed words   experiment 1 \t \u25cf\t\tuse\tthe\tlarge\tmeasuring\t cylinder\tto\tpour\t50\tcm3 of aqueous sodium thiosulfate into the conical  flask.\tplace\tthe\tconical\tflask\ton\tthe\tprinted\tinsert. \t \u25cf\t\tfill\tthe\tsmall\tmeasuring\tcylinder\twith\t10\t cm3 of dilute hydrochloric acid. \t \u25cf\t\tadd\tthe\tdilute\thydrochloric\t acid\tto\tthe\tsolution\tin\tthe\tconical\tflask.\tstart\tthe\ttimer\timmediately\t and\tswirl\tthe\tmixture. \t \u25cf\t\tview\tthe\tconical\tflask\tfrom\tabove\tand\tmeasure\tthe\ttime\ttaken\tfor\tthe\tprinted\twords\tto\tdisappear\t from view. record the time taken in the table on page 4. \t \u25cf\t\timmediately\t pour\tthe\tcontents\tof\tthe\tconical\tflask\tinto\tthe\tquenching\t bath\tand\trinse\tthe\tconical\t flask\twith\tdistilled\twater.   experiment 2 \t \u25cf\t\tuse\tthe\tlarge\tmeasuring\t cylinder\tto\tpour\t40\tcm3 of aqueous sodium thiosulfate into the conical  flask,\tfollowed\tby\t10\t cm3\tof\tdistilled\twater.\tplace\tthe\tconical\tflask\ton\tthe\tprinted\tinsert. \t \u25cf\t\tfill\tthe\tsmall\tmeasuring\tcylinder\twith\t10\t cm3 of dilute hydrochloric acid. \t \u25cf\t\tadd\tthe\tdilute\thydrochloric\t acid\tto\tthe\tsolution\tin\tthe\tconical\tflask.\tstart\tthe\ttimer\timmediately\t and\tswirl\tthe\tmixture. \t \u25cf\t\tview\tthe\tconical\tflask\tfrom\tabove\tand\tmeasure\tthe\ttime\ttaken\tfor\tthe\tprinted\twords\tto\tdisappear\t from view. record the time taken in the table on page 4. \t \u25cf\t\timmediately\t pour\tthe\tcontents\tof\tthe\tconical\tflask\tinto\tthe\tquenching\t bath\tand\trinse\tthe\tconical\t flask\twith\tdistilled\twater.",
            "4": "4 0620/51/m/j/18 \u00a9 ucles 2018  experiment 3 \t \u25cf\t\trepeat\texperiment\t 2\tbut\tuse\t35\tcm3\tof\taqueous\tsodium\tthiosulfate,\t 15\tcm3 of distilled water  and\t10\tcm3 of dilute hydrochloric acid.   experiment 4 \t \u25cf\t\trepeat\texperiment\t 2\tbut\tuse\t30\tcm3\tof\taqueous\tsodium\tthiosulfate,\t 20\tcm3 of distilled water  and\t10\tcm3 of dilute hydrochloric acid.   experiment 5 \t \u25cf\t\trepeat\texperiment\t 2\tbut\tuse\t10\tcm3\tof\taqueous\tsodium\tthiosulfate,\t 40\tcm3 of distilled water  and\t10\tcm3 of dilute hydrochloric acid.  (a)  complete the table. experimentvolume of aqueous sodium thiosulfate / cm3volume of distilled water / cm3time taken for the printed words to disappear from view / s 1 2345 [3]",
            "5": "5 0620/51/m/j/18 \u00a9 ucles 2018 [turn over  (b)\t\tplot\tyour\tresults\tfrom\texperiments\t1\u20135\ton\tthe\tgrid.\t draw\ta\tsmooth\tline\tgraph. 350 300 250 200150100 50 0 0 10 20 30 volume of aqueous sodium thiosulfate  / cm3time taken for the printed words to disappear from view  / s 40 50 [3]  (c)\t\tdescribe\tthe\tappearance\tof\tthe\tmixture\tin\tthe\tconical\tflask\tat\tthe\tend\tof\teach\texperiment.   .. \t\t[1]  (d) (i)  from your graph,\t deduce\tthe\ttime\ttaken\tfor\tthe\tprinted\twords\tto\tdisappear\t from\tview\t if\texperiment\t 2\twere\trepeated\tusing\t20\tcm3\tof\taqueous\tsodium\tthiosulfate\t and\t30\tcm3 of  distilled water. \t \tshow\tclearly\t on the grid  how you worked out your answer. \t ..\ts\t\t[2]",
            "6": "6 0620/51/m/j/18 \u00a9 ucles 2018  (ii)  the rate of reaction can be calculated using the equation shown. rate of reaction = 1 time taken   calculate the rate of reaction using your answer from (d)(i).   ... \t\t[1]  (e) (i)\t\tin\twhich\texperiment,\t1,\t2,\t3,\t4\tor\t5,\twas\tthe\trate\tof\treaction\tgreatest?   ... \t\t[1]  (ii)\t\texplain,\tin\t terms\tof\tparticles,\twhy\tthe\trate\tof\treaction\twas\tgreatest\tin\tthis\texperiment.   .   .   ... \t\t[2]  (f)  give the name of a more accurate piece of apparatus for measuring volumes than a measuring  cylinder.   .. \t\t[1]  (g)\t\tsuggest\tthe\teffect\ton\tthe\tresults\tof\tusing\ta\t100\tcm3\tconical\tflask\tinstead\tof\ta\t250\tcm3  conical\tflask.\texplain\tyour\tanswer.      .. \t\t[2]  (h)\t\tsketch\t on the grid\t the\tgraph\tyou\twould\texpect\tif\tall\tof\tthe\texperiments\t were\trepeated\tat\ta\t lower\ttemperature.\tclearly\tlabel\tyour\tgraph.\t [1] [total:\t17]",
            "7": "7 0620/51/m/j/18 \u00a9 ucles 2018 [turn over 2\t\tyou\tare\tprovided\twith\ttwo\tsubstances,\tsolution\t a and solid b. \t\tdo\tthe\tfollowing\ttests\ton\tthe\tsubstances,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.   tests on solution a \t\tdivide\tsolution\t a\tinto\tfour\tapproximately\tequal\tportions\tin\tthree\ttest-tubes\tand\tone\tboiling\ttube.  (a)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\ta. \t ph\t=\t..\t\t[1]  (b)\t\tadd\ta\tstrip\tof\tmagnesium\t ribbon\tto\tthe\tsecond\tportion\tof\tsolution\t a\tin\ta\ttest-tube.\t shake\tthe\t mixture.   record your observations.      .. \t\t[1]  (c)\t\tadd\ta\tspatula\tmeasure\tof\tcopper( ii)\toxide\tto\tthe\tthird\tportion\tof\tsolution\t a in a boiling tube.  warm\tthe\tmixture\tgently.   record your observations.   .. \t\t[1]   keep the fourth portion of solution a for the test in (e).",
            "8": "8 0620/51/m/j/18 \u00a9 ucles 2018  tests on solid b  (d)\t\tuse\ta\tspatula\tto\tplace\tapproximately\t half\tof\tsolid\t b\tinto\ta\thard\tglass\ttest-tube.\t heat\tsolid\t b  gently\tthen\tstrongly.\tleave\tthe\thard\tglass\ttest-tube\tto\tstand\tfor\tapproximately\t1\tminute.   record your observations.   .. \t\t[2]  (e)\t\tadd\tthe\trest\tof\tsolid\t b to the fourth portion of solution a\tin\ta\ttest-tube.\t test\tthe\tgas\tproduced.   record your observations.  test  .  result  .. [2]   keep the solution from the test in (e) for the test in (f). \t\tadd\tan\tapproximately\t equal\tvolume\tof\tdistilled\twater\tto\tthe\tsolution\tfrom\tthe\ttest\tin\t(e).\tshake\tthe\t solution\tand\tdivide\tit\tinto\tthree\tapproximately\t equal\tportions\tin\ttwo\ttest-tubes\t and\tone\tboiling\ttube.  (f) (i)\t\tadd\ta\tfew\tdrops\tof\taqueous\tsodium\thydroxide\t to\tthe\tfirst\tportion\tof\tthe\tsolution\tin\ta\t test-tube.   record your observations.   ... \t\t[1]  (ii)\t\tnow\tadd\tan \texcess\tof\taqueous\tsodium\t hydroxide\tto\tthe\tmixture.   record your observations.   ... \t\t[1]  (g) (i)\t\tadd\ta\tfew\tdrops\tof\taqueous\tammonia\tto\tthe\tsecond\tportion\tof\t the\tsolution\tin\ta\ttest-tube.   record your observations.   ... \t\t[1]  (ii)  now\tadd\tan\texcess\tof\taqueous\tammonia\tto\tthe\tmixture.   record your observations.   ... \t\t[1]  (h)\t\tadd\ta\tsmall\tpiece\tof\taluminium\t foil\tand\tabout\t2\tcm3\tof\taqueous\tsodium\thydroxide\t to\tthe\tthird\t portion\tof\tthe\tsolution\tin\ta\tboiling\ttube.\tgently\twarm\tthe\tmixture.\ttest\tthe\tgas\tproduced\t with\t indicator paper.   record your observations.   .. \t\t[2]",
            "9": "9 0620/51/m/j/18 \u00a9 ucles 2018 [turn over  (i)\t\tidentify\tsolution\t a.   .. \t\t[2]  (j)\t\tidentify\tsolid\tb.   .. \t\t[2] [total:\t17]",
            "10": "10 0620/51/m/j/18 \u00a9 ucles 2018 3\t\tpotassium\tchloride\tis\ta\tsalt\tthat\tdissolves\tin\twater. \t\tthe\tsolubility\tof\ta\tsalt\tis\tthe\tmass\tin\tgrams\tof\tthe\tsalt\tthat\tdissolves\t in\t100\tcm3 of water at a  particular temperature. \t\tplan\tan\tinvestigation\tto\tdetermine\tthe\tsolubility\tof\tpotassium\tchloride\tin\twater\tat\t40\t \u00b0c.   you are provided with potassium chloride and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "11": "11 0620/51/m/j/18 \u00a9 ucles 2018notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueousbarium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/51/m/j/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_s18_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52 paper 5  practical test may/june 2018  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib18 06_0620_52/4rp\u00a9 ucles 2018 *7645677451* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/52/m/j/18 \u00a9 ucles 2018 1  you are going to investigate the temperature changes when two different solids, solid c and solid d,  dissolve in water.   read all the instructions carefully before starting the experiments.   instructions   you are going to do two experiments.  (a) experiment 1 \t \u25cf\t \tput\tthe\tpolystyrene\tcup\tinto\tthe\t250\t cm3 beaker for support. \t \u25cf\t \tuse\tthe\tmeasuring\tcylinder\tto\tpour\t40\t cm3\tof\tdistilled\twater\tinto\tthe\tpolystyrene\tcup. \t \u25cf\t \tmeasure\tthe\tinitial\ttemperature\t of\tthe\tdistilled\twater\tand\trecord\tit\tin\tthe\tfirst\trow\tof\tthe\t table. \t \u25cf\t \tadd\tthe\t3\tg\tsample\tof\tsolid\t c\tto\tthe\tpolystyrene\t cup\tand\tstir\tthe\tsolution\twith\tthe\t thermometer. \t \u25cf\t \tmeasure\tand\trecord\tthe\ttemperature\tof\t the\tsolution\tafter\t1\tminute. \t \u25cf\t \tcalculate\tand\trecord\tthe\ttemperature\t change,\tincluding\twhether\tthe\ttemperature\t increased\t (+) or decreased (\u2013). \t \u25cf\t \tpour\tthe\tsolution\taway\tand\trinse\tout\tthe \tpolystyrene\tcup\twith\tdistilled\twater. \t \u25cf\t \trepeat\tthe\tprocedure\t using\tthe\t4\tg\tsample\tof\tsolid\t c.\trecord\tyour\tresults\tand\tthe\t temperature change, including whether the temperature increased (+) or decreased (\u2013), in  the appropriate row of the table. \t \u25cf\t \trepeat\tthe\tprocedure\t using\tthe\t6\tg\tsample\tof\tsolid\t c.\trecord\tyour\tresults\tand\tthe\t temperature change, including whether the temperature increased (+) or decreased (\u2013), in  the appropriate row of the table. mass of solid c / ginitial temperature of the distilled water / \u00b0ctemperature of the  solution\tafter\t1\t min\t/\t\u00b0ctemperature change / \u00b0c 3 4 6 [2]",
            "3": "3 0620/52/m/j/18 \u00a9 ucles 2018 [turn over  (b)  experiment 2 \t \u25cf\t \trepeat\texperiment\t1\tbut\tusing\tthe\t3\t g,\t4\tg,\t6\tg\tand\t8\tg\tsamples\tof\tsolid\t d. \t \u25cf\t \trecord\tyour\tresults\tin\tthe\ttable. \t \u25cf\t \tcalculate\t and\trecord\tthe\ttemperature\t changes\tin\teach\tcase,\tincluding\t whether\tthe\t temperature increased (+) or decreased (\u2013). mass of solid d / ginitial temperature of the distilled water / \u00b0ctemperature of the  solution\tafter\t1\t min\t/\t\u00b0ctemperature change / \u00b0c 3 4 6 8 [2]  (c)\t\tplot\tyour\tresults\tfor\texperiments\t 1\tand\t2\ton\tthe\tgrid.\tthe\t(0,0)\tpoint\thas\tbeen\tplotted\tfor\tyou.\t draw two\tstraight\tlines\tof\tbest\tfit. \t\tclearly\tlabel\tyour\tgraphs. 01234 mass of solid added  / g567815 10 5 0 \u20135 \u201310 \u201315temperature change  / \u00b0c [4]",
            "4": "4 0620/52/m/j/18 \u00a9 ucles 2018  (d)  use your graph\t to\testimate\tthe\ttemperature\t change\tafter\t1\tminute\tif\t8\tg\tof\tsolid\t c were added  to\t40\tcm3 of distilled water. \t\tshow\tclearly\t on the grid \thow\tyou\tworked\tout\tyour\tanswer.  .. \u00b0c\t\t[2]  (e)\t\twhat\ttype\tof\tenergy\tchange\toccurs\twhen\tsolid\t d dissolves in water?   .. \t\t[1]  (f)\t\tsuggest\tthe\ttemperature\t of\tthe\tsolution\tcontaining \t8\tg\tof\tsolid\t d, if the solution were left for  2\thours. \t\texplain\tyour\tanswer.      .. \t\t[2]  (g)\t\thow\twould\tthe\ttemperature\t changes\tmeasured\t after\t1\tminute\tdiffer\tif\tthe\texperiments\t were\t repeated\tusing\t80\t cm3\tinstead\tof\t40\t cm3 of distilled water in each case?      .. \t\t[2]  (h)  suggest one\tchange\tyou\tcould\tmake\tto\tthe\texperiments\t to\tobtain\tmore\taccurate\tresults.\t explain\thow\tthis\tchange\twould\tmake\tthe\tresults\tmore\taccurate.  change  ...  explanation      [2]  (i)\t\tsuggest\thow\tthe\treliability\tof\tthe\tresults\tcould\tbe\tchecked.      .. \t\t[2] [total:\t19]",
            "5": "5 0620/52/m/j/18 \u00a9 ucles 2018 [turn over 2  you are provided with two solid salts, solid e and solid f.   do the following tests on solid e and solid f,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.   tests on solid e  (a)  describe the appearance of solid e.   .. \t\t[1]  (b)\t\tplace\tabout\thalf\tof\tsolid\t e\tin\ta\thard\tglass\ttest-tube.\theat\tthe\tsolid\tgently\tthen\tstrongly. \t\trecord\tyour\tobservations.      .. \t\t[2] \t\tadd\tthe\trest\tof\tsolid\t e\tto\tabout\t10\tcm3 of distilled  water in a boiling tube. stopper the boiling tube  and shake it to dissolve solid e and form solution e.   divide solution e\tinto\tthree\tapproximately\tequal\t portions\tin\tthree\ttest-tubes.  (c)  add\ta\tfew\tdrops\tof\tdilute\tnitric\tacid\tand\tabout\t1\tcm3\tof\taqueous\tsilver\tnitrate\tto\tthe\tfirst\tportion\t of solution e. \t\trecord\tyour\tobservations.   .. \t\t[1]  (d)  add\ta\tfew\tdrops\tof\tdilute\tnitric\tacid\tand\tabout\t1\tcm3\tof\taqueous\tbarium\tnitrate\tto\tthe\tsecond\t portion of solution e. \t\trecord\tyour\tobservations.   .. \t\t[1]  (e)  add\tan\texcess\tof\taqueous\tsodium\thydroxide\tto\tthe\tthird\tportion\tof\tsolution\t e. \t\trecord\tyour\tobservations.   .. \t\t[2]  (f)\t\tidentify\tsolid\te.   .. \t\t[2]",
            "6": "6 0620/52/m/j/18 \u00a9 ucles 2018   tests on solid f \t\tadd\tsolid\t f\tto\tabout\t10\tcm3 of distilled water in a boiling tube. stopper the boiling tube and shake  it to dissolve solid f and form solution f.   divide solution f\tinto\tthree\tapproximately\tequal\t portions\tin\tthree\ttest-tubes.  (g)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tf. ph\t=\t..\t\t[1]  (h) (i)\t\tadd\ta\tfew\tdrops\tof\taqueous\tsodium\thydroxide\t to\tthe\tsecond\tportion\tof\tsolution\t f and  shake the mixture. \t \trecord\tyour\tobservations.   ... \t\t[2]  (ii)\t\tnow\tadd\tan \texcess\tof\taqueous\tsodium\t hydroxide\tto\tthe\tmixture. \t \trecord\tyour\tobservations.   ... \t\t[1]  (i)\t\tadd\tan\texcess\tof\taqueous\tammonia\tto\tthe\tthird\tportion\tof\tsolution\t f. \t\trecord\tyour\tobservations.   .. \t\t[1]  (j)\t\twhat\tconclusion\tcan\tyou\tdraw\tabout\tthe\tcation\tpresent\tin\tsolid\t f?      .. \t\t[1] [total:\t15]",
            "7": "7 0620/52/m/j/18 \u00a9 ucles 2018 [turn over 3\t\taqueous\tsolutions\tof\tbarium\thydroxide\tare\talkaline. \t plan\tan\tinvestigation\tto\tfind\tthe\tconcentration\tof\t an\taqueous\tsolution\tof\tbarium\thydroxide. \t\tyou\tare\tprovided\twith\tan\taqueous\tsolution\tof\tbarium\thydroxide,\t dilute\thydrochloric\t acid\tof\tknown\t concentration\tand\tcommon\tlaboratory\tapparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6] [total:\t6]",
            "8": "8 0620/52/m/j/18 \u00a9 ucles 2018blank page",
            "9": "9 0620/52/m/j/18 \u00a9 ucles 2018blank page",
            "10": "10 0620/52/m/j/18 \u00a9 ucles 2018blank page",
            "11": "11 0620/52/m/j/18 \u00a9 ucles 2018notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueousbarium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/52/m/j/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_s18_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53 paper 5  practical test may/june 2018  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 11  printed pages and 1 blank page. [turn overib18 06_0620_53/3rp\u00a9 ucles 2018 *6726715019* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use total",
            "2": "2 0620/53/m/j/18 \u00a9 ucles 2018 1  you are going to investigate how the temperature changes when aqueous sodium hydroxide reacts  with solutions of two different acids, acid r and acid s.   read all the instructions carefully before starting the experiments.   instructions   you are going to do two experiments.  (a)  experiment 1 \t \u25cf\t \tput\tthe\tpolystyrene\tcup\tinto\tthe\t250\t cm3 beaker for support. \t \u25cf\t \tuse\tthe\tmeasuring\t cylinder\tto\tpour\t50\tcm3 of aqueous sodium hydroxide into the  polystyrene cup. \t \u25cf\t \tmeasure\tthe\ttemperature\tof\tthe\tsolution \tand\trecord\tit\tin\tthe\ttable. \t \u25cf\t\t \tfill\tthe\tburette\tup\tto\tthe\t0.0\t cm3 mark with acid r. \t \u25cf\t\t \tadd\t5.0\tcm3 of acid r to the aqueous sodium hydroxide in the polystyrene cup and stir the  solution with the thermometer. \t \u25cf\t\t \tmeasure\tand\trecord\tthe\thighest\ttemperature\tof\tthe\tsolution\tin\tthe\ttable. \t \u25cf\t \tadd\ta\tfurther\t5.0\tcm3 of acid r to the polystyrene cup and stir the solution with the  thermometer. \t \u25cf\t \tmeasure\tand\trecord\tthe\thighest\ttemperature\tof\tthe\tsolution\tin\tthe\ttable. \t \u25cf\t \tcontinue\tto\tadd\t5.0\tcm3 portions of acid r to the polystyrene cup until a total volume of  40.0\tcm3 of acid r has been added. stir after each addition and measure and record the  highest temperature of the solution in the table in each case. \t \u25cf\t\t \tpour\tthe\tsolution\taway\tand\trinse\tthe\tpolystyrene\tcup. volume of acid r added / cm3 highest temperature of the solution / \u00b0c 0.0 5.0 10.0 15.020.025.030.035.040.0 [2]",
            "3": "3 0620/53/m/j/18 \u00a9 ucles 2018 [turn over  (b)\t\tplot\tyour\tresults\tfor\texperiment\t1\ton\tthe\tgrid\tand\tdraw\ttwo intersecting straight line graphs. 50 45 40 353025 20 15 10 0.0 5.0 10.0 15.0 volume of acid r added  / cm3highest temperature of the solution  / \u00b0c 20.0 25.0 30.0 35.0 40.0 [2]",
            "4": "4 0620/53/m/j/18 \u00a9 ucles 2018  (c)  experiment 2 \t \u25cf\t \tempty\tthe\tburette\tand\trinse\tit\twith\tdistilled\twater.\tdiscard\tthis\tliquid. \t \u25cf\t \trinse\tthe\tburette\twith\tsome\tof\tacid\t s.\tdiscard\tthis\tacid. \t \u25cf\t \trepeat\texperiment\t1\tbut\tusing\tacid\t s instead of acid r. \t \u25cf\t record\tyour\tresults\tin\tthe\ttable. volume of acid s added / cm3 highest temperature of the solution / \u00b0c 0.0 5.0 10.015.020.025.030.035.040.0 [2]",
            "5": "5 0620/53/m/j/18 \u00a9 ucles 2018 [turn over  (d)\t\tplot\tyour\tresults\tfor\texperiment\t2\ton\tthe\tgrid\tand\tdraw\ttwo intersecting straight line graphs. 50 45 40 35 30 25 20 15 10 0.0 5.0 10.0 15.0 volume of acid s added  / cm3highest temperature of the solution  / \u00b0c 20.0 25.0 30.0 35.0 40.0 [2]  (e) (i)  use your graph to estimate the volume of acid s which must be added to neutralise  50\tcm3 of aqueous sodium hydroxide.   show clearly on the grid  how you worked out your answer.  .. cm3\t\t[2]",
            "6": "6 0620/53/m/j/18 \u00a9 ucles 2018  (ii)  suggest how the volume in (e)(i)\t would\tdiffer\tif\tthe\texperiment\t were\trepeated\tusing\t25\tcm3  instead\tof\t50\t cm3 of aqueous sodium hydroxide. \t \texplain\tyour\tanswer.   .   ... \t\t[2]  (f)  what type of energy change occurs when acid s reacts with aqueous sodium hydroxide?   .. \t\t[1]  (g) (i)\t\tin\texperiment\t2,\twhy\twas\tthe\tburette\trinsed\twith\tdistilled\twater?   ... \t\t[1]  (ii) why was the burette then rinsed with acid s?   ... \t\t[1]  (h)\t\tdescribe\tone\t source\tof\terror\tin\texperiment\t2.\t suggest\tan\t improvement\tto\t reduce\tthis\t source\t of error.  source of error  ...  improvement  .. [2] [total:\t17]",
            "7": "7 0620/53/m/j/18 \u00a9 ucles 2018 [turn over 2  you are provided with two substances, solution t and liquid u. \t\tdo\tthe\tfollowing\ttests\ton\tthe\tsubstances,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.  tests on solution t \t\tdivide\tsolution\t t into four approximately equal portions in three test-tubes and one boiling tube.  (a) (i)\t\tdo\ta\tflame\ttest\ton\tthe\tfirst\tportion\tof\tsolution\tt. \t \trecord\tyour\tobservations.   ... \t\t[1]  (ii)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tt. \t ph\t=\t..\t\t[1]  (b) \u25cf\t\tadd\ta\tfew\tdrops\tof\taqueous\tzinc\tsulfate\tto\tthe\tsecond\tportion\tof\tsolution\t t in a test-tube.  shake the test-tube to mix the solutions. \t \trecord\tyour\tobservations.   . \t \u25cf\t \tadd\tan\texcess\tof\taqueous\tzinc\tsulfate\tto\tthe\tmixture. \t \trecord\tyour\tobservations.   . \t [3]  (c)\t\tadd\ta\tsmall\tspatula\tmeasure\tof\tammonium\t chloride\tto\tthe\tthird\tportion\tof\tsolution\t t in a  boiling tube. warm the mixture carefully. test the gas produced. \t\trecord\tyour\tobservations.      .. \t\t[2]  (d) \u25cf\t\tadd\ta\tfew\tdrops\tof\taqueous\tchromium( iii) chloride to the fourth portion of solution t in a  test-tube. \t \trecord\tyour\tobservations.   . \t \u25cf\t \tadd\tan\texcess\tof\taqueous\tchromium( iii) chloride to the mixture. \t \trecord\tyour\tobservations.   . \t [3]  (e)  identify solution t.   .. \t\t[2]",
            "8": "8 0620/53/m/j/18 \u00a9 ucles 2018  tests on liquid u  (f)\t\tdescribe\tthe\tappearance\tof\tliquid\t u.   .. \t\t[1]  (g)\t\tadd\tabout\t10\tcm3 of aqueous iodine to about 1 cm3 of liquid u\t in\ta\tboiling\ttube.\tadd\tdrops\tof\t aqueous sodium hydroxide until the brown colour of the aqueous iodine is removed. \t\trecord\tyour\tobservations.      .. \t\t[2]  (h)\t\tuse\ta\tteat\tpipette\tto\tplace\ta\tfew\tdrops\tof\tliquid\t u\ton\tto\ta\twatch\tglass.\tuse\ta\tlighted\tsplint\tto\t touch the surface of the liquid carefully.   .. \t\t[1]  (i)  what conclusion can you draw about liquid u?   .. \t\t[1] [total:\t17]",
            "9": "9 0620/53/m/j/18 \u00a9 ucles 2018 [turn over 3  some trees have purple leaves. the purple colour is a mixture of coloured pigments. \t\tplan\tan\texperiment\tto\textract\tand\tseparate\tthe\tcoloured\tpigments\tpresent\tin\tthe\tpurple\tleaves.   you are provided with some purple leaves, sand, ethanol and common laboratory apparatus.   you may draw a diagram to help you answer the question.   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6] [total:\t6]",
            "10": "10 0620/53/m/j/18 \u00a9 ucles 2018blank page",
            "11": "11 0620/53/m/j/18 \u00a9 ucles 2018notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueousbarium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/53/m/j/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test results metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_s18_qp_61.pdf": {
            "1": "this document consists of 11  printed pages and 1 blank page. [turn overib18 06_0620_61/3rp \u00a9 ucles 2018 *3983955427* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61 paper 6  alternative to practical may/june 2018  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/61/m/j/18 \u00a9 ucles 2018 1  the volume of dilute nitric acid that reacts with 25.0 cm3 of aqueous potassium hydroxide can be  found by titration using the apparatus shown. 25.0  cm3 of aqueou s potassium hydroxide with indicatordilute nitric acid.. .  (a)  complete the box to name the apparatus.   [1]  (b)  name a suitable indicator that could be used.   ..   [1]   a student did the titration four times and recorded the following results. titration number volume of dilute nitric acid / cm3 1 18.1 2 18.9 3 18.3 4 18.2  (c) (i) which one of the results is anomalous?   ...   [1]  (ii)  suggest what might have caused this result to be anomalous.   ...   [1]  (iii)  use the other results to calculate the average volume of dilute nitric acid that reacted with  the aqueous potassium hydroxide.   ...   [2]",
            "3": "3 0620/61/m/j/18 \u00a9 ucles 2018 [turn over  (d)  the equation for the reaction taking place in the titration is shown. hno3  +  koh    kno3  +  h2o   the student concluded that the aqueous potassium hydroxide was more concentrated than the  dilute nitric acid.   explain whether or not the student\u2019s conclusion was correct.         ..   [2] [total: 8]",
            "4": "4 0620/61/m/j/18 \u00a9 ucles 2018 2  a student investigated the rate of reaction between dilute hydrochloric acid and aqueous  sodium thiosulfate. when these chemicals react they form a precipitate which makes the solution  go cloudy. the formation of this precipitate can be used to show how fast the reaction proceeds.   five experiments were done using the apparatus shown. aqueous sodium thiosulfat eeye 10 cm3 of dilute hydrochloric acid 250  cm3 conical flas k printed sheet of pap er printed words",
            "5": "5 0620/61/m/j/18 \u00a9 ucles 2018 [turn over  experiment 1 \t \u25cf\t \ta\tlarge\tmeasuring\t cylinder\t was\tused\tto\tpour\t50\tcm3 of aqueous sodium thiosulfate into a  250 cm3\tconical\tflask.\t the\tconical\tflask\twas\tplaced\ton\ta\tprinted\tsheet\tof\tpaper. \t \u25cf\t \t10\tcm3\tof\tdilute\thydrochloric\t acid\twas\tadded\tto\tthe\tsolution\t in\tthe\tconical\tflask.\ta\ttimer\twas\t started immediately and the mixture was swirled. \t \u25cf\t \tthe\ttime\ttaken\tfor\tthe\tprinted\twords\tto\tdisappear\tfrom\tview\twas\tmeasured.   experiment 2 \t \u25cf\t \tthe\tlarge\tmeasuring\t cylinder\t was\tused\tto\tpour\t40\tcm3 of aqueous sodium thiosulfate into a  conical\tflask,\tfollowed\t by\t10\tcm3\tof\tdistilled\t water.\tthe\tconical\t flask\twas\tplaced\t on\tthe\tprinted\t sheet of paper. \t \u25cf\t \t10\tcm3\tof\tdilute\thydrochloric\t acid\twas\tadded\tto\tthe\tsolution\tin\tthe\tconical\tflask.\tthe\ttimer\twas\t started immediately and the mixture was swirled. \t \u25cf\t \tthe\ttime\ttaken\tfor\tthe\tprinted\twords\tto\tdisappear\tfrom\tview\twas\tmeasured.   experiment 3 \t \u25cf\t \texperiment\t 2\twas\trepeated\t but\tusing\t35\tcm3 of aqueous sodium thiosulfate and 15 cm3 of  distilled water.   experiment 4 \t \u25cf\t \texperiment\t 2\twas\trepeated\t but\tusing\t30\tcm3 of aqueous sodium thiosulfate and 20 cm3 of  distilled water.   experiment 5 \t \u25cf\t \texperiment\t 2\twas\trepeated\t but\tusing\t10\tcm3 of aqueous sodium thiosulfate and 40 cm3 of  distilled water.",
            "6": "6 0620/61/m/j/18 \u00a9 ucles 2018  (a)  record the volumes of distilled water used in the table. use the stop-clock diagrams to record  the results in the table. experimentvolume of aqueous sodium thiosulfate / cm3volume of distilled water / cm3stop-clock diagramtime taken for the printed words to disappear from view / s 1 500 0 10 3015 1545 5seconds minutes 2 400 0 10 3015 1545 5 3 350 0 10 3015 1545 5 4 300 0 10 3015 1545 5 5 100 0 10 3015 1545 5 [3]",
            "7": "7 0620/61/m/j/18 \u00a9 ucles 2018 [turn over  (b)  plot the results from experiments 1\u20135 on the grid. draw a smooth line graph. 240 210 180 150120 90 60 30 0 0 10 20 30 volume of aqueous sodium thiosulfate  / cm3time taken for the printed words to disappear from view  / s 40 50 [3]  (c) (i)  from your graph,\t deduce\tthe\ttime\ttaken\tfor\tthe\tprinted\twords\tto\tdisappear\t from\tview\t if experiment 2 were repeated using 20 cm3 of aqueous sodium thiosulfate and 30 cm3 of  distilled water.   show clearly on the grid  how you worked out your answer.  .. s  [2] ",
            "8": "8 0620/61/m/j/18 \u00a9 ucles 2018  (ii)  the rate of reaction can be calculated using the equation shown. rate of reaction = 1 time taken   calculate the rate of reaction using your answer from (c)(i).   ...   [1]  (d) (i)\t \tin\twhich\texperiment,\t1,\t2,\t3,\t4\tor\t5,\twas\tthe\trate\tof\treaction\tgreatest?   ...   [1]  (ii)\t\texplain,\tin\t terms\tof\tparticles,\twhy\tthe\trate\tof\treaction\twas\tgreatest\tin\tthis\texperiment.   .   .   ...   [2]  (e)  give the name of a more accurate piece of apparatus for measuring volumes than a measuring  cylinder.   ..   [1]  (f)  suggest the effect on the results of using a 100 cm3\tconical\tflask\tinstead\tof\ta\t250\tcm3 conical  flask.\texplain\tyour\tanswer.      ..   [2]  (g)  sketch on the grid the graph you would expect if all of the experiments were repeated at a  lower temperature. clearly label your graph. [1] [total: 16]",
            "9": "9 0620/61/m/j/18 \u00a9 ucles 2018 [turn over 3\t\ttwo\tsubstances,\tsolution\t a and solid b,\twere\tanalysed.   tests on solution a   some of the tests and observations are shown. tests on solution a observations solution a was divided into three equal portions  in three test-tubes. test 1 the\tph\tof\tthe\tfirst\tportion\tof\tsolution\t a was  tested.ph = 1 test 2 magnesium ribbon was added to the second  portion of solution a. the gas produced was tested.effervescence gas \u2018popped\u2019 with a lighted splint test 3 dilute nitric acid and aqueous barium nitrate  were added to the third portion of solution a.white precipitate formed  (a)  identify the gas produced in test 2.   ..   [1]  (b)  identify solution a.   ..   [2]",
            "10": "10 0620/61/m/j/18 \u00a9 ucles 2018  tests on solid b   solid b was zinc carbonate.   complete the expected observations.  (c)  dilute nitric acid was added to solid b. the gas produced was tested.  observations  ..   ..   [2]   the zinc nitrate solution formed in the test in (c) was divided into two portions in two test-tubes.  (d) (i)\t \tdrops\tof\taqueous\t sodium\thydroxide\t were\tadded\tto\tthe\tfirst\tportion\tof\tthe\tzinc\tnitrate\t solution.  observations  .   [2]  (ii)  an excess of aqueous sodium hydroxide was then added to the mixture.  observations  .   [1]  (e) (i)  drops of aqueous ammonia were added to the second portion of the zinc nitrate solution.  observations  .   [1]  (ii)  an excess of aqueous ammonia was then added to the mixture.  observations  .   [1] [total: 10]",
            "11": "11 0620/61/m/j/18 \u00a9 ucles 2018 [turn over 4  potassium chloride is a salt that dissolves in water.   the solubility of a salt is the mass in grams of the salt that dissolves in 100 cm3 of water at a  particular temperature.   plan an investigation to determine the solubility of potassium chloride in water at 40 \u00b0c.   you are provided with potassium chloride and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "12": "12 0620/61/m/j/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        },
        "0620_s18_qp_62.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib18 06_0620_62/3rp \u00a9 ucles 2018 *2312854938* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6  alternative to practical may/june 2018  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/m/j/18 \u00a9 ucles 2018 1  the rate of reaction between an excess of dilute nitric acid and powdered calcium carbonate was  investigated. the carbon dioxide produced was collected. the apparatus used is shown. dilute nitric acid powdered calcium carbonate .  (a)  complete the box to name the apparatus. [1]   a sketch graph of the results obtained is shown. timex  (b) (i)  label the y-axis. [1]  (ii)  explain why the sketch graph is horizontal at point x.   .   ...   [2]  (c)  draw on the axes the graph expected if the experiment were repeated using an equal mass  of lumps of calcium carbonate. all other conditions were kept the same. [2]  (d)  describe a test for carbon dioxide.  test  .  result  .. [2] [total: 8]",
            "3": "3 0620/62/m/j/18 \u00a9 ucles 2018 [turn over 2  a student investigated the temperature changes when two different solids, solid c and solid d,  dissolved in water.   two experiments were done.  experiment 1 \t \u25cf\t \tusing\ta\tmeasuring\t cylinder,\t 40\tcm3 of distilled water was poured into a polystyrene cup. the  initial temperature of the distilled water was measured. \t \u25cf\t \t3\tg\tof\tsolid\t c was added to the polystyrene cup and the mixture was stirred with a thermometer.  the temperature of the solution was measured after 1 minute. \t \u25cf\t \tthe\tprocedure\twas\trepeated\tusing\t4\t g\tof\tsolid\tc. \t \u25cf\t \tthe\tprocedure\twas\trepeated\tusing\t6\t g\tof\tsolid\tc.  (a)\t\tuse\tthe\tthermometer\tdiagrams\tto\trecord\tthe\tresults \tin\tthe\ttable.   calculate and record the temperature change in each case, including whether the temperature  increased (+) or decreased (\u2013). mass of  solid c / gthermometer diagraminitial  temperature of the distilled  water / \u00b0cthermometer diagramtemperature of the solution after 1 min / \u00b0ctemperature change / \u00b0c 330 25 2020 15 10 430 25 2020 15 10 630 25 2020 15 10 [2]",
            "4": "4 0620/62/m/j/18 \u00a9 ucles 2018  experiment 2 \t \u25cf\t \texperiment\t1\twas\trepeated\tbut\tusing\t3\t g,\t4\tg,\t6\tg\tand\t8\tg\tof\tsolid\td .  (b)\t\tuse\tthe\tthermometer\tdiagrams\tto\trecord\tthe\tresults \tin\tthe\ttable.   calculate and record the temperature change in each case, including whether the temperature  increased (+) or decreased (\u2013). mass of  solid d / gthermometer diagraminitial  temperature of the distilled  water / \u00b0cthermometer diagramtemperature of the solution after 1 min / \u00b0ctemperature change / \u00b0c 330 25 2030 25 20 430 25 2030 25 20 630 25 2030 25 20 830 25 2040 35 30 [2]",
            "5": "5 0620/62/m/j/18 \u00a9 ucles 2018 [turn over  (c)\t\tplot\tthe\tresults\tfor\texperiments\t 1\tand\t2\ton\tthe\tgrid.\tthe\t(0,0)\tpoint\thas\tbeen\tplotted\tfor\tyou.\t draw two\tstraight\tlines\tof\tbest\tfit.   clearly label your graphs. 01234 mass of solid added  / g5 67815 10 5 0 \u20135 \u201310temperature change  / \u00b0c [4]  (d)  use your graph to estimate the temperature change after 1 minute if 8 g of solid c were added  to\t40\tcm3 of distilled water.   show clearly on the grid  how you worked out your answer.  .. \u00b0c  [2]  (e)  what type of energy change occurs when solid d dissolves in water?   ..   [1]  (f)  suggest the temperature of the solution containing 8 g of solid d, if the solution were left for  2 hours.   explain your answer.      ..   [2]",
            "6": "6 0620/62/m/j/18 \u00a9 ucles 2018  (g)  how would the temperature changes measured after 1 minute differ if the experiments were  repeated\tusing\t80\t cm3\tinstead\tof\t40\t cm3 of distilled water in each case?      ..   [2]  (h)  suggest one change you could make to the experiments to obtain more accurate results.   explain how this change would make the results more accurate.  change  ...  explanation      [2]  (i)  suggest how the reliability of the results could be checked.      ..   [2] [total: 19]",
            "7": "7 0620/62/m/j/18 \u00a9 ucles 2018 [turn over 3  two substances, solid  e and solution f, were analysed. solid e was iron( ii) sulfate. tests were  done on solid e and solution f.  tests on solid e   complete the expected observations.  (a)  describe the appearance of solid e.   ..   [1]   solid e was added to distilled water in a test-tube. the test-tube was shaken to dissolve solid e and  form solution e. solution e was divided into four equal portions in four test-tubes.  (b)\t\tdilute\tnitric\tacid\tand\taqueous\tsilver\tnitrate\twere\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t e.  observations     [1]  (c)  dilute nitric acid and aqueous barium nitrate were added to the second portion of solution e.  observations     [1]  (d)  an excess of aqueous sodium hydroxide was added to the third portion of solution e.  observations     [2]  (e)  an excess of aqueous ammonia was added to the fourth portion of solution e.  observations     [1]",
            "8": "8 0620/62/m/j/18 \u00a9 ucles 2018  tests on solution f   solution f was an aqueous salt solution.   some of the tests and observations are shown. tests on solution f observations solution f was divided into two equal portions in  two test-tubes. test 1 drops of aqueous sodium hydroxide were added  to\tthe\tfirst\tportion\tof\tsolution\tf. an excess of aqueous sodium hydroxide was  then added to the mixture.white precipitate formed white precipitate was insoluble test 2 an excess of aqueous ammonia was added to  the second portion of solution f.no precipitate formed  (f)  what conclusion can you draw about the cation present in solution f?      ..   [1] [total: 7]",
            "9": "9 0620/62/m/j/18 \u00a9 ucles 2018 [turn over 4  aqueous solutions of barium hydroxide are alkaline. \t\tplan\tan\tinvestigation\tto\tfind\tthe\tconcentration\tof\t an\taqueous\tsolution\tof\tbarium\thydroxide.   you are provided with an aqueous solution of barium hydroxide, dilute hydrochloric acid of known  concentration and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6] [total:\t6]",
            "10": "10 0620/62/m/j/18 \u00a9 ucles 2018blank page",
            "11": "11 0620/62/m/j/18 \u00a9 ucles 2018blank page",
            "12": "12 0620/62/m/j/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        },
        "0620_s18_qp_63.pdf": {
            "1": "this document consists of 11  printed pages and 1 blank page. [turn overib18 06_0620_63/3rp \u00a9 ucles 2018 *7230714520* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6  alternative to practical may/june 2018  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/63/m/j/18 \u00a9 ucles 2018 1  zinc sulfate crystals are hydrated. they contain water of crystallisation. a student did an experiment  to find the mass of water in hydrated zinc sulfate crystals.   the hydrated zinc sulfate crystals were weighed and then heated with a bunsen burner to remove  the water as shown. abhydrated zinc sulfate crystals. heathydrated zinc sulfate crystalswatch glass  (a) (i)  name the apparatus used to weigh the crystals in a.   ...   [1]  (ii)  complete the box to name the apparatus. [1]  (b)  what position should the air hole of the bunsen burner be in when heating the hydrated  zinc sulfate crystals in b?   ..   [1]  (c)  describe how the student could find out if all of the water of crystallisation had been removed from the hydrated zinc sulfate crystals.         ..   [2]  (d)  describe a chemical test for water.  test  .  result  .. [2] [total: 7]",
            "3": "3 0620/63/m/j/18 \u00a9 ucles 2018 [turn over 2  a student investigated how the temperature changed when aqueous sodium hydroxide reacted  with solutions of two different acids, acid r and acid s.   two experiments were done.  experiment 1  \u25cf  a measuring cylinder was used to pour 50 cm3 of aqueous sodium hydroxide into a polystyrene  cup. the temperature of the solution was measured.  \u25cf  a burette was filled up to the 0.0 cm3 mark with acid r.  \u25cf  5.0 cm3 of acid r was added to the aqueous sodium hydroxide in the polystyrene cup and the  solution stirred.  \u25cf  the highest temperature of the solution was measured.  \u25cf  a further 5.0 cm3 of acid r was added to the polystyrene cup and the solution was stirred.  \u25cf  the highest temperature of the solution was measured.  \u25cf  further 5.0 cm3 portions of acid r were added to the polystyrene cup until a total volume of  40.0 cm3 of acid r had been added. the highest temperature of the solution was measured  after each addition.",
            "4": "4 0620/63/m/j/18 \u00a9 ucles 2018  (a) use the thermometer diagrams to record the results in the table. 30 25 20thermometer diagramvolume of acid r added  / cm3 0.0highest temperature of the solution  / \u00b0c 30 25 205.0 30 25 2010.0 30 25 2015.0 30 25 2020.0 40 35 3025.0 30 25 2030.0 30 25 2035.0 30 25 2040.0 [2]",
            "5": "5 0620/63/m/j/18 \u00a9 ucles 2018 [turn over  (b)  plot the results for experiment 1 on the grid and draw two intersecting straight line graphs. 40 35 30 2520 15 0.0 5.0 10.0 15.0 volume of acid r added  / cm3highest temperature of the solution  / \u00b0c 20.0 25.0 30.0 35.0 40.0 [2]",
            "6": "6 0620/63/m/j/18 \u00a9 ucles 2018  experiment 2  \u25cf  the burette was rinsed with distilled water and then with acid s.  \u25cf  experiment 1 was repeated but using acid s instead of acid r.  (c)  use the thermometer diagrams to record the results in the table. 30 25 20thermometer diagramvolume of acid s added  / cm3 0.0 30 25 205.0 40 35 3010.0 40 35 3015.0 40 35 3020.0 30 25 2025.0 30 25 2030.0 30 25 2035.0 30 25 2040.0highest temperature of the solution  / \u00b0c [2]",
            "7": "7 0620/63/m/j/18 \u00a9 ucles 2018 [turn over  (d)  plot the results for experiment 2 on the grid and draw two intersecting straight line graphs. 40 35 30 25 20 15 0.0 5.0 10.0 15.0 volume of acid s added  / cm3highest temperature of the solution  / \u00b0c 20.0 25.0 30.0 35.0 40.0 [2]  (e) (i)  use your graph to estimate the volume of acid s which must be added to neutralise  50 cm3 of aqueous sodium hydroxide.   show clearly on the grid  how you worked out your answer.  .. cm3  [2]  (ii)  suggest how the volume in (e)(i) would differ if the experiment were repeated using 25 cm3  instead of 50 cm3 of aqueous sodium hydroxide.   explain your answer.   .   ...   [2]  (f)  what type of energy change occurs when acid s reacts with aqueous sodium hydroxide?   ..   [1]",
            "8": "8 0620/63/m/j/18 \u00a9 ucles 2018  (g) (i)  in experiment 2, why was the burette rinsed with distilled water?   ...   [1]  (ii) why was the burette then rinsed with acid s?   ...   [1]  (h)  describe one source of error in experiment 2. suggest an improvement to reduce this source  of error.  source of error  ...  improvement  .. [2] [total: 17]",
            "9": "9 0620/63/m/j/18 \u00a9 ucles 2018 [turn over 3  solution t and liquid u were analysed. solution t was aqueous sodium hydroxide.   tests were done on solution t and liquid u.  tests on solution t   complete the expected observations.   solution t was divided into four portions in three test-tubes and one boiling tube.  (a) (i)  a flame test was done on the first portion of solution t.  observations  .   [1]  (ii)  the ph of the first portion of solution t was tested.  ph = ..  [1]  (b) \u25cf  a few drops of aqueous zinc sulfate were added to the second portion of solution t in a  test-tube. the test-tube was shaken to mix the solutions.  observations  ...  \u25cf  an excess of aqueous zinc sulfate was then added to the mixture.  observations  ...  [3]  (c)  ammonium chloride was added to the third portion of solution t in a boiling tube. the mixture  was heated and the gas produced was tested.  test  .  observations  ..  [2] (d)  an excess of aqueous chromium( iii) chloride was added to the fourth portion of solution t in  a test-tube.  observations     [2]",
            "10": "10 0620/63/m/j/18 \u00a9 ucles 2018  tests on liquid u   some of the tests and observations are shown. tests on liquid u observations the appearance of liquid u was studied. colourless, pleasant smelling a few drops of liquid u were placed on to a watch  glass. the surface of the liquid was touched with a  lighted splint.burned with a blue flame  (e)  what conclusion can you draw about liquid u?   ..   [1] [total: 10]",
            "11": "11 0620/63/m/j/18 \u00a9 ucles 2018 [turn over 4  some trees have purple leaves. the purple colour is a mixture of coloured pigments.   plan an experiment to extract and separate the coloured pigments present in the purple leaves.   you are provided with some purple leaves, sand, ethanol and common laboratory apparatus.   you may draw a diagram to help you answer the question.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6] [total: 6]",
            "12": "12 0620/63/m/j/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        },
        "0620_w18_qp_11.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 16 printed pages.  ib18 11_0620_11/3rp  \u00a9 ucles 2018 [turn over     *9115702337 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1  multiple choice (core)  october/november 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/11/o/n/18  1 a beaker containing solid carbon dioxide is placed in a fume cupboard at room temperature. the  carbon dioxide becomes gaseous.    which process describes this change of state?  a boiling  b condensation  c evaporation  d sublimation     2 the pressure of a sample of gas is decreased. the temperature is kept constant.    which row describes the effects on the particles?     movement of particles collisions between  particles  a slower occur less often  b slower occur with more force  c no change in speed occur less often  d no change in speed occur with more force      3 which statement about paper chromatography is correct?  a a solvent is needed to dissolve the paper.  b paper chromatography separates mixtures of solvents.  c the solvent should cover the baseline.  d the baseline should be drawn in pencil.     ",
            "3": "3  \u00a9 ucles 2018 0620/11/o/n/18 [turn over  4 the diagrams show four pieces of laboratory equipment.    thermomete r stop-clock pipette balance     which equipment is essential to find out if dissolving a salt in water is an exothermic process?     balance pipette stop-clock thermometer  a \u001a \u001a \u001a \u0016  b \u0016 \u001a \u001a \u0016  c \u001a \u0016 \u001a \u0016  d \u0016 \u001a \u0016 \u001a      5 iodine, i, has a lower relative atomic mass than tellurium, te, but is placed after it in the  periodic table.    te i     which statement explains why iodine is placed after tellurium in the periodic table?  a iodine has fewer neutrons than tellurium.  b iodine has fewer protons than tellurium.  c iodine has more neutrons than tellurium.  d iodine has more protons than tellurium.     ",
            "4": "4  \u00a9 ucles 2018 0620/11/o/n/18  6 substance q has a high melting point and conducts electricity both when molten and when  dissolved in water.    what is q?  a calcium chloride  b diamond  c iron  d silver chloride    7 elements x and y form an ionic compound, xy.    in which group of the periodic table is x found and how is the bond between x and y formed?     group in which  x is found how the bond between  x and y is formed  a i by x gaining one electron from y  b i by x transferring one electron to y  c vii by x sharing electrons with y  d vii by x transferring one electron to y      8 the structure of glycine is shown.    nco h h oh hc h    which row is correct?     formula of glycine number of different  elements in glycine  a ch 5o2n 10  b c2h5o2n 4  c c2h5o2n 10  d h2nchcooh 4     ",
            "5": "5  \u00a9 ucles 2018 0620/11/o/n/18 [turn over  9 calcium phosphate forms when calcium chloride and sodium phosphate solutions react together.    x cac l 2  +  y na3po 4  \u2192  2ca 3(po 4)2  +  12nac l    which values of x and y balance the equation?     x y  a 2 2  b 3 4  c 6 3  d 6 4     10 during the electrolysis of concentrated aqueous sodium chloride, chlorine gas is produced at the  positive electrode.    what happens at the negative electrode and to the solution?     product at  the negative  electrode the solution  becomes  a hydrogen acidic  b hydrogen alkaline  c sodium acidic  d sodium alkaline     ",
            "6": "6  \u00a9 ucles 2018 0620/11/o/n/18  11 the diagram shows an experiment to electroplate a nickel spoon with silver.    electrolytenickel spoonpower supply     which row correctly describes the positive electrode, the negative electrode and the electrolyte?     positive  electrode negative  electrode electrolyte  a nickel spoon pure nickel silver nitrate solution  b nickel spoon pure silver nickel nitrate solution  c pure nickel nickel spoon silver nitrate solution  d pure silver nickel spoon silver nitrate solution      12 which substance does not use oxygen to produce heat energy?  a coal  b hydrogen  c natural gas  d uranium     ",
            "7": "7  \u00a9 ucles 2018 0620/11/o/n/18 [turn over  13 an energy level diagram for a reaction is shown.    energy progress of reactionreactantsproducts     which statement about the reaction is correct?  a heat is released.  b it is a combustion reaction.  c it is an endothermic reaction.  d the temperature increases.     14 two reactions are done.    1 hydrated cobalt( ii) chloride is heated. it changes colour.  2 water is added to the product of reaction 1. it becomes hotter. the original colour is  produced.    which types of reaction have occurred in reactions 1 and 2?     endothermic exothermic neutralisation reversible  a \u0016 \u0016 \u0016 \u0016  b \u0016 \u0016 \u0016 \u001a  c \u0016 \u0016 \u001a \u0016  d \u0016 \u001a \u001a \u0016      15 which equation shows reduction of an iron compound?  a 4fe  +  3o 2  \u2192  2fe 2o3  b fe  +  2hc l  \u2192  fec l 2  +  h 2  c 4feo  +  o 2  \u2192  2fe 2o3  d fe2o3  +  3co  \u2192  2fe  +  3co 2    ",
            "8": "8  \u00a9 ucles 2018 0620/11/o/n/18  16 calcium carbonate reacts with dilute hydrochloric acid to make carbon dioxide gas. graph x  shows the results of this experiment.    the particle size of the calcium carbonate is increased and the experiment is repeated. all other  conditions are kept the same. graph y shows the results of this experiment.    which diagram is correct for the two experiments?    volume of carbon dioxideproduced  / cm3 time  / sa xy volume of carbon dioxideproduced  / cm3 time  / sb xy yx volume of carbon dioxideproduced  / cm3 time  / sc yx volume of carbon dioxideproduced  / cm3 time  / sd00 00 00 00      17 part of the periodic table is shown.    which element forms an oxide that reacts with dilute acid to form a salt and water?    i ii iii iv v vi vii viii cdab      ",
            "9": "9  \u00a9 ucles 2018 0620/11/o/n/18 [turn over  18 an excess of substance z is added to some spilt acid.    the solution produced as a result is neutral.    what is z?  a aqueous ammonia  b aqueous sodium hydroxide  c calcium carbonate  d water     19 aqueous sodium hydroxide is added to solid q in a test-tube.    a gas is produced which turns damp red litmus blue.    what is q?  a aluminium  b ammonia  c ammonium chloride  d sodium nitrate    20 potassium hydroxide is a base.    which statement describes a reaction of potassium hydroxide?  a chlorine is formed when it is heated with ammonium chloride.  b it turns universal indicator green.  c it reacts with an acid to produce a salt and water.  d it turns methyl orange red.    21 which statement about the periodic table is not correct?  a it can be used to find the atomic number of an element.  b it can be used to find the physical state of an element.  c it can be used to find the symbol of an element.  d it can be used to predict the properties of an element.    ",
            "10": "10  \u00a9 ucles 2018 0620/11/o/n/18  22 elements in group i of the periodic table react with water.    which row describes the products made in the reaction and the trend in reactivity of the elements?     products trend in reactivity  a metal hydroxide and hydrogen less reactive down the group  b metal hydroxide and hydrogen more reactive down the group  c metal oxide and hydrogen less reactive down the group  d metal oxide and hydrogen more reactive down the group     23 the equation shows the reaction between a halogen and aqueous bromide ions.    x 2 + 2br\u2013 \u2192 2x\u2013 + br 2   ..1.. ..2.. ..3..    which words complete gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     24 an inert gas r is used to fill weather balloons.    which descriptions of r are correct?     number of outer shell  electrons in atoms of r structure of gas r  a 2 diatomic molecules  b 2 single atoms  c 8 diatomic molecules  d 8 single atoms     ",
            "11": "11  \u00a9 ucles 2018 0620/11/o/n/18 [turn over  25 metal x reacts with steam but not with cold water.    what is x?  a calcium  b copper  c sodium  d zinc     26 which process is used to extract aluminium from bauxite?  a heating bauxite in air  b heating bauxite with carbon  c heating bauxite with hydrogen  d passing electricity through purified bauxite    27 which row shows uses of the metals listed?     aluminium copper mild steel  a aircraft manufacture food containers cutlery  b cutlery electrical wiring chemical plant  c electrical wiring aircraft manufacture cooking utensils  d food containers cooking utensils car bodies     28 argon is a noble gas used to fill light bulbs.    what is the approximate percentage of argon in air?  a 1% b 20% c 79% d 99%     ",
            "12": "12  \u00a9 ucles 2018 0620/11/o/n/18  29 the diagrams show experiments involving the rusting of iron.    water boiled to remove the airwater anhydrouscalcium chlorideto dry the airoil iron nailstube q tube r tube p     a student predicted the following results.    1 in tube p, the iron nails rust.  2 in tube q, the iron nails do not rust. 3 in tube r, the iron nails do not rust.    which predictions are correct?  a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     30 which statement about air pollutants is not correct?  a carbon monoxide is formed from the complete combustion of petroleum.  b lead compounds are formed from some types of petrol.  c oxides of nitrogen are formed from the combustion reactions inside car engines.  d sulfur dioxide is formed from the combustion of coal.    ",
            "13": "13  \u00a9 ucles 2018 0620/11/o/n/18 [turn over  31 the table describes three types of water.    water  type source of  water appearance before  treatment treatment appearance after  treatment  p river muddy none muddy  q river muddy filtration and chlorination clear  r well clear chlorination only clear    which statement is correct?  a only q and r are suitable for drinking, while p could be used for irrigation.  b only q and r are suitable for drinking, while p is unsuitable for any purpose.  c only q is suitable for drinking. r could be used for washing cars and p for irrigation.  d p, q and r are suitable for irrigation and washing cars, but are not suitable for drinking.    32 which compound would not be used as an important part of a garden fertiliser?  a ca 3(po 4)2 b kno 3 c mg(oh) 2 d (nh 4)2so 4     33 carbon dioxide and methane both contribute to climate change.   which process produces both gases?  a complete combustion of natural gas  b farming cattle  c heating calcium carbonate  d respiration      34 which reaction is endothermic?  a caco 3  \u2192  cao  +  co 2  b cao  +  2hc l  \u2192  cac l 2  +  h 2o  c 2ca  +  o 2  \u2192  2cao  d ca  +  2hc l  \u2192  cac l 2  +  h 2     ",
            "14": "14  \u00a9 ucles 2018 0620/11/o/n/18  35 petroleum is a mixture of different hydrocarbons.    which process is used to separate the petroleum into groups of similar hydrocarbons?  a combustion  b cracking  c fractional distillation  d reduction     36 which two compounds are molecules which both contain a double bond?  a ethane and ethanoic acid  b ethane and ethanol  c ethene and ethanoic acid  d ethene and ethanol    37 which pair of diagrams shows compounds belonging to the same homologous series?    o ohc hh hch hco oh ch hha c h hh hc c hch hch hh hb hch ho ho hoc c hh ch hch hhh ch hc ho ch hch hhh ch hh c d      ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/11/o/n/18  38 ethanol can be formed by:    1 fermentation  2 reaction between steam and ethene.    which of these processes use a catalyst?     1 2  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     39 which statement about ethanoic acid is correct?  a it fizzes with magnesium ribbon.  b it forms a salt with hydrochloric acid.  c it is a hydrocarbon.  d it forms a solution in water with a ph greater than ph  7.    40 which statement about terylene  is correct?  a it is a form of protein.  b it is a natural polymer.  c it is also called poly(ethene).  d it is used to make clothes.    ",
            "16": "16  \u00a9 ucles 2018 0620/11/o/n/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w18_qp_12.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 15 printed pages and 1 blank page.  ib18 11_0620_12/3rp  \u00a9 ucles 2018 [turn over     *1771435356* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1  multiple choice (core)  october/november 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/12/o/n/18  1 a gas is heated. the pressure is kept constant.    which statement describes the behaviour of the particles in the gas?  a the particles move faster and become closer together.  b the particles move faster and become further apart.  c the particles move slower and become closer together.  d the particles move slower and become further apart.      2 in which state does 1  dm3 of methane contain the most particles?  a gas at 100  \u00b0c  b gas at room temperature  c liquid  d solid     3 the chromatogram obtained from four mixtures of dyes, p, q, r and s, is shown.    baselinesolvent front p q r s    what is the total number of different dyes identified in the four mixtures?  a 3 b 4 c 5 d 8    ",
            "3": "3  \u00a9 ucles 2018 0620/12/o/n/18 [turn over  4 the diagrams show four pieces of laboratory equipment.    thermomete r stop-clock pipette balance     which equipment is essential to find out if dissolving a salt in water is an exothermic process?     balance pipette stop-clock thermometer  a \u001a \u001a \u001a \u0016  b \u0016 \u001a \u001a \u0016  c \u001a \u0016 \u001a \u0016  d \u0016 \u001a \u0016 \u001a      5 how many neutrons are present in the atom x45 21?  a 21 b 24 c 45 d 66    6 strontium nitrate is an ionic compound.    cyclohexane is a covalent compound.    which row describes a property of each compound?     strontium nitrate cyclohexane  a conducts electricity in aqueous solution low boiling point  b low melting point insoluble in water  c soluble in water conducts electricity when solid  d conducts electricity when solid high melting point     ",
            "4": "4  \u00a9 ucles 2018 0620/12/o/n/18  7 ionic bonds are formed when elements from group i and group vii react together.    which statement about ions or ionic compounds is not correct?  a electrons from one atom are transferred to another atom to form ions.  b group vii atoms gain electrons to form ions.  c negative ions are formed when atoms lose electrons.  d molten ionic compounds conduct electricity.     8 what is the relative formula mass of mg(oh) 2?  a 21 b 30 c 42 d 58     9 calcium carbonate, caco 3, reacts with dilute hydrochloric acid to produce carbon dioxide.    the equation for the reaction is shown. the relative formula mass of calcium carbonate is 100.    caco 3  +  2hc l  \u2192  cac l 2  +  h 2o  +  co 2    10  g of calcium carbonate is reacted with an excess of dilute hydrochloric acid.    which mass of carbon dioxide is produced?  a 2.2  g b 2.8  g c 4.4  g d 44  g    10 concentrated hydrochloric acid and dilute sulfur ic acid were electrolysed in separate experiments  using carbon electrodes.    which statement is correct for both electrolysis experiments?  a chlorine gas is produced at the positive electrode.  b hydrogen gas is produced at the positive electrode.  c hydrogen gas is produced at the negative electrode.  d oxygen gas is produced at the negative electrode.     ",
            "5": "5  \u00a9 ucles 2018 0620/12/o/n/18 [turn over  11 aqueous nickel( ii) sulfate is used as the electrolyte to electroplate a piece of steel with nickel.    which materials are used as the negative electrode and positive electrode?     negative  electrode positive  electrode  a carbon steel  b nickel steel  c platinum nickel  d steel nickel      12 which substance does not use oxygen to produce heat energy?  a coal  b hydrogen  c natural gas  d uranium    13 equal volumes and concentrations of dilute hydr ochloric acid and aqueous sodium hydroxide are  mixed. the temperatures of the solutions are shown.    solution temperature  / \u00b0c  dilute hydrochloric acid 26  aqueous sodium hydroxide 26  mixture of dilute hydrochloric acid and  aqueous sodium hydroxide 33      which statement describes the reaction?  a energy is released and the products have less energy than the reactants.  b energy is released and the products have more energy than the reactants.  c energy is absorbed and the products have less energy than the reactants.  d energy is absorbed and the products have more energy than the reactants.    ",
            "6": "6  \u00a9 ucles 2018 0620/12/o/n/18  14 a student heats hydrated copper( ii) sulfate. the blue crystals change to a white powder.    how can the student reverse this reaction?  a add anhydrous copper( ii) sulfate to the white powder.  b add water to the white powder.  c cool the white powder.  d reheat the white powder.      15 which compound is written with the oxidation state ( vii)?  a cuso 4 b feso 4 c fe 2(so 4)3 d kmno 4    16 magnesium powder reacts with an excess of dilute  hydrochloric acid to produce hydrogen gas.    which statements about this reaction are correct?    1 the smaller the particles of magnesium powder, the slower hydrogen is produced.  2 the higher the temperature, the faster the magnesium powder disappears. 3 the lower the concentration of dilute hydrochloric acid, the faster the rate of  reaction.  4 the faster the magnesium powder disappears, the faster the rate of reaction.    a 1 and 2 b 2 and 3 c 2 and 4 d 3 and 4    17 in which row are the oxides correctly identified?     acidic basic  a magnesium oxide, calcium oxide su lfur dioxide, carbon dioxide  b magnesium oxide, sulfur dioxide carbon dioxide, calcium oxide  c sulfur dioxide, carbon dioxide calcium oxide, magnesium oxide  d sulfur dioxide, magnesium oxide calcium oxide, carbon dioxide     ",
            "7": "7  \u00a9 ucles 2018 0620/12/o/n/18 [turn over  18 the following steps are done to prepare solid magnesium sulfate.    1 filtration  2 measurement of 20  cm3 of dilute sulfuric acid using a measuring cylinder  3 evaporation  4 addition of an excess of solid magnesium carbonate to dilute sulfuric acid    what is the correct order for these steps?  a 2 \u2192 4 \u2192 3 \u2192 1  b 2 \u2192 4 \u2192 1 \u2192 3  c 4 \u2192 2 \u2192 1 \u2192 3  d 4 \u2192 2 \u2192 3 \u2192 1     19 when dilute sulfuric acid is added to solid x, a colourless solution is formed and a gas is  produced.    what is x?  a copper( ii) oxide  b sodium oxide  c copper( ii) carbonate  d sodium carbonate      20 a few drops of methyl orange are added to a reaction mixture.    during the reaction, a gas is produced and the methyl orange turns from red to orange.    what are the reactants?  a aqueous sodium hydroxide and ammonium chloride  b aqueous sodium hydroxide and calcium carbonate  c dilute hydrochloric acid and magnesium  d dilute hydrochloric acid and aqueous sodium hydroxide    ",
            "8": "8  \u00a9 ucles 2018 0620/12/o/n/18  21 the positions of two elements, p and q, in the periodic table are shown.    p q     p and q react together to form a compound.    what is the formula of the compound?  a qp b q 2p c q 7p d qp 7    22 elements in group i of the periodic table react with water.    which row describes the products made in the reaction and the trend in reactivity of the  elements?     products trend in reactivity  a metal hydroxide and hydrogen less reactive down the group  b metal hydroxide and hydrogen more reactive down the group  c metal oxide and hydrogen less reactive down the group  d metal oxide and hydrogen more reactive down the group      23 the equation shows the reaction between a halogen and aqueous bromide ions.    x2 + 2br\u2013 \u2192 2x\u2013 + br 2   ..1.. ..2.. ..3..    which words complete gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     ",
            "9": "9  \u00a9 ucles 2018 0620/12/o/n/18 [turn over  24 an inert gas r is used to fill weather balloons.    which descriptions of r are correct?     number of outer shell  electrons in atoms of r structure of gas r  a 2 diatomic molecules  b 2 single atoms  c 8 diatomic molecules  d 8 single atoms     25 four metals, w, x, y and z, are separately reacted with water and dilute hydrochloric acid.    the results are shown.     metal  w x y z  reaction with water fizzes no reaction fizzes  vigorously no reaction    reaction with dilute  hydrochloric acid fizzes no reaction fizzes  violently fizzes      what is the order of reactivity of the four  metals starting with the least reactive?     least reactive  most reactive  a x w z y  b x z w y  c y w z x  d y z w x     ",
            "10": "10  \u00a9 ucles 2018 0620/12/o/n/18  26 part of the reactivity series is shown.    potassium most reactive  carbon  zinc  iron  copper least reactive    which metal must be extracted from its ore by electrolysis?  a copper  b iron  c potassium  d zinc    27 which statement about the uses of metals is not correct?  a aluminium is used in aircraft because of it s strength and good electrical conductivity.  b copper is used in electrical wiring because of its good electrical conductivity.  c stainless steel resists corrosion and is used to make cutlery.  d transition elements are often used as catalysts.    28 argon is a noble gas used to fill light bulbs.    what is the approximate percentage of argon in air?  a 1% b 20% c 79% d 99%    ",
            "11": "11  \u00a9 ucles 2018 0620/12/o/n/18 [turn over  29 the diagrams show experiments involving the rusting of iron.    water boiled to remove the airwater anhydrouscalcium chlorideto dry the airoil iron nailstube q tube r tube p     a student predicted the following results.    1 in tube p, the iron nails rust.  2 in tube q, the iron nails do not rust. 3 in tube r, the iron nails do not rust.    which predictions are correct?  a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    30 which statements about sulfur dioxide pollution are correct?    1 it increases the ph of rivers.  2 it damages limestone buildings.  3 it causes respiratory problems.    a 1 only b 2 only c 1 and 3 d 2 and 3    ",
            "12": "12  \u00a9 ucles 2018 0620/12/o/n/18  31 the table describes three types of water.    water  type source of  water appearance before  treatment treatment appearance after  treatment  p river muddy none muddy  q river muddy filtration and chlorination clear  r well clear chlorination only clear    which statement is correct?  a only q and r are suitable for drinking, while p could be used for irrigation.  b only q and r are suitable for drinking, while p is unsuitable for any purpose.  c only q is suitable for drinking. r could be used for washing cars and p for irrigation.  d p, q and r are suitable for irrigation and washing cars, but are not suitable for drinking.    32 which compound would not be used as an important part of a garden fertiliser?  a ca 3(po 4)2 b kno 3 c mg(oh) 2 d (nh 4)2so 4     33 carbon dioxide and methane both contribute to climate change.   which process produces both gases?  a complete combustion of natural gas  b farming cattle  c heating calcium carbonate  d respiration      34 what is not a use of lime?  a it is used as a bleach in the manufacture of wood pulp.  b it is used to desulfurise flue gases.  c it is used to neutralise acidic industrial waste.  d it is used to treat acidic soil.     ",
            "13": "13  \u00a9 ucles 2018 0620/12/o/n/18 [turn over  35 petroleum is a mixture of different hydrocarbons.    which process is used to separate the petroleum into groups of similar hydrocarbons?  a combustion  b cracking  c fractional distillation  d reduction     36 which two compounds are molecules which both contain a double bond?  a ethane and ethanoic acid  b ethane and ethanol  c ethene and ethanoic acid  d ethene and ethanol    37 which molecule does not belong to the alcohol homologous series?    hch hcha ho h hch hch ob hc o h hh ch hch hc och hhch h hch hd hc o h      ",
            "14": "14  \u00a9 ucles 2018 0620/12/o/n/18  38 ethanol can be formed by:    1 fermentation  2 reaction between steam and ethene.    which of these processes use a catalyst?     1 2  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a      39 ethanoic acid is a weak acid.    which statements about ethanoic acid are correct?    1 it turns universal indicator purple.  2 it reacts with magnesium to form hydrogen gas.  3 it reacts with calcium carbonate to form carbon dioxide gas. 4 it decolourises aqueous bromine.    a 1, 2 and 3 b 1 and 2 only c 2, 3 and 4 d 2 and 3 only      40 which substance is a natural polymer?  a ethene  b glucose  c nylon  d protein     ",
            "15": "15    permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/12/o/n/18  ",
            "16": "16  \u00a9 ucles 2018 0620/12/o/n/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w18_qp_13.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level1/level 2 certificate .  this document consists of 16 printed pages.  ib18 11_0620_13/4rp  \u00a9 ucles 2018 [turn over     *1803649773 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1  multiple choice (core)  october/november 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.    ",
            "2": "2  \u00a9 ucles 2018 0620/13/o/n/18  1 the statements describe two changes of state.    1 the molecules of substance x are arranged randomly.  during the change of state, they lose energy and become more ordered. the  molecules can still move freely.  2 the molecules of substance y are arranged in a regular lattice.  during the change of state, they gain energy and become less ordered. the  molecules are still close together.    which changes of state are described by the statements?     1 2  a condensation evaporation  b condensation melting  c freezing evaporation  d freezing melting     2 which statement about gases is correct?  a gases are difficult to compress when pressure is applied.  b the particles in gases are close together.  c the particles in gases have a random arrangement.  d the particles in gases move slowly past each other.     3 salt is added to pure water to form an aqueous solution.    which statement is correct?  a the melting point and the boiling point of the water both decrease.  b the melting point and the boiling point of the water both increase.  c the melting point of the water decreases but its boiling point increases.  d the melting point of the water increases but its boiling point decreases.     ",
            "3": "3  \u00a9 ucles 2018 0620/13/o/n/18 [turn over  4 the diagrams show four pieces of laboratory equipment.    thermomete r stop-clock pipette balance     which equipment is essential to find out if dissolving a salt in water is an exothermic process?     balance pipette stop-clock thermometer  a \u001a \u001a \u001a \u0016  b \u0016 \u001a \u001a \u0016  c \u001a \u0016 \u001a \u0016  d \u0016 \u001a \u0016 \u001a      5 which statement describes isotopes?  a isotopes of the same element have different electron arrangements.  b isotopes of the same element have different nuclear charges.  c isotopes of the same element have nuclei with masses that are the same.  d isotopes of the same element have the same number of protons.     6 substance x conducts electricity.    what is x?  a a typical covalent compound in the liquid state  b a typical covalent compound in the solid state  c a typical ionic compound in the liquid state  d a typical ionic compound in the solid state    ",
            "4": "4  \u00a9 ucles 2018 0620/13/o/n/18  7 which statement describes the elements in group i?  a they all form ions by gaining electrons.  b they all form ions with the same charge.  c they have different numbers of electrons in their outer shells.  d they all have the same number of electron shells.      8 calcium phosphate has the formula ca 3(po 4)2.    what is the relative formula mass of calcium phosphate?  a 135 b 215 c 230 d 310     9 limestone fizzes and dissolves in dilute hydrochloric acid.    what is the word equation for the reaction which occurs?  a calcium carbonate + hydrochloric acid \u2192 calcium chloride + water + carbon dioxide  b calcium carbonate + hydrochloric acid \u2192 calcium chloride + hydrogen  c calcium hydroxide + hydrochloric acid \u2192 calcium chloride + water  d calcium oxide + hydrochloric acid \u2192 calcium chloride + water      10 when solution q is electrolysed using carbon electrodes, colourless gases are produced at both  electrodes.    what is q?  a concentrated hydrochloric acid  b concentrated sodium chloride solution  c dilute sulfuric acid  d pure water    11 which electrodes and electrolyte can be used to electroplate a copper medal with gold?     positive electrode negative electrode electrolyte  a copper gold an aqueous copper compound  b copper gold an aqueous gold compound  c gold copper an aqueous copper compound  d gold copper an aqueous gold compound     ",
            "5": "5  \u00a9 ucles 2018 0620/13/o/n/18 [turn over  12 which substance does not use oxygen to produce heat energy?  a coal  b hydrogen  c natural gas  d uranium     ",
            "6": "6  \u00a9 ucles 2018 0620/13/o/n/18  13 which row describes an endothermic reaction?     energy level diagram energy transfer  a energy progress of reaction energy is transferred  from the surroundings  to the reaction  b energy progress of reaction energy is transferred  from the surroundings  to the reaction  c energy progress of reaction energy is transferred  from the reaction  to the surroundings  d energy progress of reaction energy is transferred  from the reaction  to the surroundings    ",
            "7": "7  \u00a9 ucles 2018 0620/13/o/n/18 [turn over  14 when solid hydrated cobalt( ii) chloride crystals are heated they turn blue and steam is produced.    adding water to the blue crystals turns them pink.    which type of reaction has occurred?  a neutralisation  b oxidation  c reduction  d reversible     15 iron( iii) oxide reacts with carbon monoxide.    the equation is shown.    fe2o3  +  3co  \u2192  2fe  +  3co 2    which substance is reduced?  a co b co 2 c fe d fe2o3     16 in experiment 1, 1  g of calcium carbonate is reacted with an excess of dilute hydrochloric acid.  the volume of gas produced every minute is recorded.    in experiment 2, experiment 1 is repeated using smaller pieces of calcium carbonate. all other  conditions are kept the same.    the results from both experiments are shown.    time  / s 0 60 120 180 240  volume of gas from  experiment 1  / cm3 0 98 172 212 220  volume of gas from  experiment 2  / cm3 0 157 209 220 220    which statement about experiment 2 is correct?  a the rate of reaction is faster than in experiment 1 and there is the same amount of product.  b the rate of reaction is faster than in experiment 1 and there is more product.  c the rate of reaction is the same as in experiment 1 and there is the same amount of product.  d the rate of reaction is the same as in experiment 1 and there is more product.     ",
            "8": "8  \u00a9 ucles 2018 0620/13/o/n/18  17 the results of some experiments with sulfur dioxide are shown.    experiment description result  1 mix with dilute hydrochloric acid does not react  2 mix with concentrated sodium hydroxide a salt forms  3   add universal indicator   universal indicator  turns purple  4   add acidified aqueous  potassium manganate( vii) purple solution  turns colourless    which results are correct?  a 1, 2 and 4 b 2, 3 and 4 c 1 and 2 only d 3 and 4 only     18 a student prepares solid hydrated copper( ii) sulfate from dilute sulfuric acid and the insoluble  base copper( ii) oxide.    which process is not used in the procedure?  a crystallisation  b distillation  c evaporation  d filtration    19 a white precipitate is produced when small amounts of two colourless solutions are mixed  together.    which pairs of solutions produce a white precipitate?    1 sodium hydroxide and zinc nitrate  2 sodium hydroxide and aluminium chloride  3 barium chloride and sulfuric acid  4 acidified barium nitrate and potassium sulfate    a 1, 2, 3 and 4  b 1, 2 and 4 only  c 1 and 2 only  d 2 only    ",
            "9": "9  \u00a9 ucles 2018 0620/13/o/n/18 [turn over  20 solution q is warmed with ammonium chloride.    in a separate experiment, solution q is added to methyl orange.    which observations show that solution q is basic?     warmed with  ammonium chloride added to   methyl orange  a gas is produced turns red  b gas is produced turns yellow  c no reaction turns red  d no reaction turns yellow     21 which statement about elements in the periodic table is correct?  a elements are arranged in order of increasing nucleon number.  b elements change from non-metallic to metallic across a period.  c elements in the same period have similar properties.  d elements on the left of the periodic table form basic oxides.     22 elements in group i of the periodic table react with water.    which row describes the products made in the reaction and the trend in reactivity of the elements?     products trend in reactivity  a metal hydroxide and hydrogen less reactive down the group  b metal hydroxide and hydrogen more reactive down the group  c metal oxide and hydrogen less reactive down the group  d metal oxide and hydrogen more reactive down the group     ",
            "10": "10  \u00a9 ucles 2018 0620/13/o/n/18  23 the equation shows the reaction between a halogen and aqueous bromide ions.    x2 + 2br\u2013 \u2192 2x\u2013 + br 2   ..1.. ..2.. ..3..    which words complete gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     24 an inert gas r is used to fill weather balloons.    which descriptions of r are correct?     number of outer shell  electrons in atoms of r structure of gas r  a 2 diatomic molecules  b 2 single atoms  c 8 diatomic molecules  d 8 single atoms     25 calcium reacts with cold water to produce hydrogen.    lead reacts slowly when heated in air to form an  oxide but has almost no reaction with steam.    silver does not react with either air or water.    zinc reacts when heated with steam to produce hydrogen.    what is the order of reactivity starting with the least reactive?     least reactive   most reactive  a calcium lead zinc silver  b calcium zinc lead silver  c silver lead zinc calcium  d silver zinc lead calcium     ",
            "11": "11  \u00a9 ucles 2018 0620/13/o/n/18 [turn over  26 iron and potassium are both metals.    which row shows the reactivity of the metal and how it is extracted from its ore?     metal reactivity extracted by  a iron high electrolysis  b iron medium heating with carbon  c potassium medium electrolysis  d potassium high heating with carbon     27 which row describes the use of a metal and the property upon which the use depends?     metal use property  a aluminium aircraft bodies aluminium is a heat conductor  b aluminium cooking utensils aluminium has a low density  c copper cooking utensils copper has a high density  d copper electrical wiring copper is a good conductor of electricity     28 argon is a noble gas used to fill light bulbs.    what is the approximate percentage of argon in air?  a 1% b 20% c 79% d 99%     ",
            "12": "12  \u00a9 ucles 2018 0620/13/o/n/18  29 the diagrams show experiments involving the rusting of iron.    water boiled to remove the airwater anhydrouscalcium chlorideto dry the airoil iron nailstube q tube r tube p     a student predicted the following results.    1 in tube p, the iron nails rust.  2 in tube q, the iron nails do not rust. 3 in tube r, the iron nails do not rust.    which predictions are correct?  a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     30 which equation represents the incomplete combustion of propane, c 3h8?  a 2c 3h8  +  7o 2  \u2192  6co  +  8h 2o  b c 3h8  +  5o 2  \u2192  3co 2  +  4h 2o  c 2c 3h8  +  11o 2  \u2192  6co  +  16h 2o  d c 3h8  +  7o 2  \u2192  3co 2  +  8h 2o     ",
            "13": "13  \u00a9 ucles 2018 0620/13/o/n/18 [turn over  31 the table describes three types of water.    water  type source of  water appearance before  treatment treatment appearance after  treatment  p river muddy none muddy  q river muddy filtration and chlorination clear  r well clear chlorination only clear    which statement is correct?  a only q and r are suitable for drinking, while p could be used for irrigation.  b only q and r are suitable for drinking, while p is unsuitable for any purpose.  c only q is suitable for drinking. r could be used for washing cars and p for irrigation.  d p, q and r are suitable for irrigation and washing cars, but are not suitable for drinking.    32 which compound would not be used as an important part of a garden fertiliser?  a ca 3(po 4)2 b kno 3 c mg(oh) 2 d (nh 4)2so 4     33 carbon dioxide and methane both contribute to climate change.   which process produces both gases?  a complete combustion of natural gas  b farming cattle  c heating calcium carbonate  d respiration      34 which equation represents the formation of lime?  a caco 3  \u2192  cao  +  co 2  b cao  +  h 2o  \u2192  ca(oh) 2  c ca  +  2h 2o  \u2192  ca(oh) 2  +  h 2  d ca(oh) 2  +  co 2  \u2192  caco 3  +  h 2o     ",
            "14": "14  \u00a9 ucles 2018 0620/13/o/n/18  35 petroleum is a mixture of different hydrocarbons.    which process is used to separate the petroleum into groups of similar hydrocarbons?  a combustion  b cracking  c fractional distillation  d reduction     36 which two compounds are molecules which both contain a double bond?  a ethane and ethanoic acid  b ethane and ethanol  c ethene and ethanoic acid  d ethene and ethanol     37 which statement about any homologous series is correct?  a the first member contains one carbon atom only.  b the members all contain carbon and hydrogen only.  c the members all contain the same functional group.  d the members all contain the same number of carbon atoms.    38 ethanol can be formed by:    1 fermentation  2 reaction between steam and ethene.    which of these processes use a catalyst?     1 2  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/13/o/n/18 39 which statement about ethanoic acid is not correct?  a it is insoluble in water.  b it reacts with sodium hydroxide to form a salt.  c it reacts with some metals to form hydrogen gas.  d it is a carboxylic acid.      40 some information about poly(ethene) is given.    \u25cf poly(ethene) is used to make plastic bags.  \u25cf poly(ethene) plastic bags in landfill sites do not readily decompose.  \u25cf poly(ethene) molecules contain carbon and hydrogen atoms.    which statement about poly(ethene) is correct?  a it is biodegradable.  b it is combustible.  c it is unsaturated.  d it reacts with water.    ",
            "16": "16  \u00a9 ucles 2018 0620/13/o/n/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w18_qp_21.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib18 11_0620_21/3rp  \u00a9 ucles 2018 [turn over     *4207030076 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/21     paper 2  multiple choice (extended)  october/november 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2018 0620/21/o/n/18  1 when smoke particles are observed with a microscope they are seen to move around randomly.  this is called brownian motion.    what causes brownian motion?  a diffusion of the smoke particles  b molecules in the air hitting the smoke particles  c sublimation of the smoke particles  d the smoke particles hitting the walls of the container    2 the diagrams show four pieces of laboratory equipment.    thermomete r stop-clock pipette balance     which equipment is essential to find out if dissolving a salt in water is an exothermic process?     balance pipette stop-clock thermometer  a \u001a \u001a \u001a \u0016  b \u0016 \u001a \u001a \u0016  c \u001a \u0016 \u001a \u0016  d \u0016 \u001a \u0016 \u001a     ",
            "3": "3  \u00a9 ucles 2018 0620/21/o/n/18 [turn over  3 iodine, i, has a lower relative atomic mass than tellurium, te, but is placed after it in the  periodic table.    te i     which statement explains why iodine is placed after tellurium in the periodic table?  a iodine has fewer neutrons than tellurium.  b iodine has fewer protons than tellurium.  c iodine has more neutrons than tellurium.  d iodine has more protons than tellurium.      4 which statement about the isotopes of an element is correct?  a their physical properties are different because they have different proton numbers.  b their atomic masses are different because they have different numbers of electron shells.  c they have the same chemical properties because they have the same number of electrons in  their outer shells.  d they have the same physical properties becaus e they have the same number of neutrons in  their nuclei.     5 which two molecules contain the same number of electrons?  a c l  2 and so 2  b ch 4 and h 2o  c co and nh 3  d co 2 and hc l      6 which statement describes the lattice structure of a metal?  a the lattice consists of alternating positive ions and negative ions.  b the lattice consists of neutral atoms arranged in layers.  c the lattice consists of positive ions in a \u2018sea of electrons\u2019.  d the lattice consists of neutral atoms in a \u2018sea of electrons\u2019.    ",
            "4": "4  \u00a9 ucles 2018 0620/21/o/n/18  7 which gas sample contains the most molecules?  a 24  dm3 of carbon dioxide, co 2  b 4  g of hydrogen, h 2  c 36  dm3 of hydrogen chloride, hc l  d 14  g of nitrogen, n 2    8 a student mixed together 25.0  cm3 of 1.00  mol  / dm3 hydrochloric acid and 25.0  g of  calcium carbonate.    2hc l (aq)  +  caco 3(s)  \u2192  cac l 2(aq)  +  h 2o(l)  +  co 2(g)    what is the maximum volume of carbon dioxide gas that could be collected at room temperature  and pressure?  a 300  dm3 b 6.00  dm3 c 0.600  dm3 d 0.300  dm3      9 iron can react with sulfur to form two ionic compounds.    the iron is present as fe2+ in one compound and as fe3+ in the other compound.    the sulfur ion is present as s2\u2013 in both compounds.    what are the formulae of the two compounds?  a fes and  fe2s3  b fes and fe 3s2  c fes 2 and fe 3s2  d fes 2 and fe 2s3      10 aqueous copper( ii) sulfate is electrolysed using carbon electrodes.    what is the product at each electrode?     product at the  positive electrode product at the  negative electrode  a copper oxygen  b hydrogen oxygen  c oxygen copper  d oxygen hydrogen     ",
            "5": "5  \u00a9 ucles 2018 0620/21/o/n/18 [turn over  11 the diagram shows a circuit used to electrolyse aqueous copper( ii) sulfate.    +\u2013   2134 copper electrodes aqueous copper( ii) sulfatepower supply +\u2013     which arrows indicate the movement of the copper ions in the electrolyte and of the electrons in  the external circuit?     copper ions electrons  a 1 3  b 1 4  c 2 3  d 2 4      12 methane burns in an excess of oxygen. the equation is shown.    ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(g)    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013h +410  c=o +805  o\u2013h +460  o=o +496    what is the energy change for the reaction?  a +818  kj / mol  b +102  kj / mol  c \u2013359  kj / mol  d \u2013818  kj / mol   ",
            "6": "6  \u00a9 ucles 2018 0620/21/o/n/18  13 the equation for the formation of ammonia is shown.    n2  +  3h 2  \u2192  2nh 3    the energy level diagram for the reaction is shown.    energy progress of reactionenergy changen2  +  3h2 2nh3total energy released = \u2013342  kj / molactivation energy = +250  kj / mol     what is the energy change for the reaction?  a \u2013592  kj / mol  b \u201392  kj / mol  c +92  kj / mol  d +592  kj / mol     14 the effects of a change in conditions on a chemical reaction are listed.    1 the total number of collisions per minute increased.  2 the number of effective collisions per minute increased.  3 the average energy of the particles increased.    which change in conditions caused all of these effects?  a addition of a catalyst  b increasing the concentration of a solution of a reactant  c increasing the surface area of a solid reactant  d increasing the temperature     ",
            "7": "7  \u00a9 ucles 2018 0620/21/o/n/18 [turn over  15 when bic l 3 reacts with water, a white precipitate of bioc l is formed. the equation for the  reaction is shown.    bic l 3(aq)  +  h 2o(l)    bioc l (s)  +  2hc l (aq)    which statements are correct?    1 the reaction is reversible.  2 when dilute hydrochloric acid is added to the reaction mixture, more of the white  precipitate forms.  3 when aqueous sodium hydroxide is added to the reaction mixture, more of the white  precipitate forms.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      16 an excess of iron( ii) chloride is added to acidified potassium manganate( vii).    which statements are correct?    1 the purple colour disappears.  2 iron( ii) is reduced to iron( iii).  3 manganate( vii) ions are oxidised to manganese( ii) ions.  4 potassium manganate( vii) is an oxidising agent.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     17 part of the periodic table is shown.    which element forms an oxide that reacts with dilute acid to form a salt and water?    i ii iii iv v vi vii viii cdab      ",
            "8": "8  \u00a9 ucles 2018 0620/21/o/n/18  18 aqueous sodium hydroxide is added to solid q in a test-tube.    a gas is produced which turns damp red litmus blue.    what is q?  a aluminium  b ammonia  c ammonium chloride  d sodium nitrate     19 potassium hydroxide is a base.    which statement describes a reaction of potassium hydroxide?  a chlorine is formed when it is heated with ammonium chloride.  b it turns universal indicator green.  c it reacts with an acid to produce a salt and water.  d it turns methyl orange red.      20 some general rules for the solubility of salts in water are listed.    \u25cf carbonates are insoluble (except ammonium carbonate, potassium carbonate and  sodium carbonate).  \u25cf chlorides are soluble (except lead( ii) chloride and silver chloride).  \u25cf nitrates are soluble.  \u25cf sulfates are soluble (except barium sulfate, calcium sulfate and lead( ii) sulfate).    which substances produce an insoluble salt when aqueous solutions of them are mixed?  a barium chloride and magnesium nitrate  b calcium chloride and ammonium nitrate  c silver nitrate and zinc chloride  d sodium carbonate and potassium sulfate     ",
            "9": "9  \u00a9 ucles 2018 0620/21/o/n/18 [turn over  21 elements in group i of the periodic table react with water.    which row describes the products made in the reaction and the trend in reactivity of the elements?     products trend in reactivity  a metal hydroxide and hydrogen less reactive down the group  b metal hydroxide and hydrogen more reactive down the group  c metal oxide and hydrogen less reactive down the group  d metal oxide and hydrogen more reactive down the group     22 the equation shows the reaction between a halogen and aqueous bromide ions.    x 2 + 2br\u2013 \u2192 2x\u2013 + br 2   ..1.. ..2.. ..3..    which words complete gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     23 an inert gas r is used to fill weather balloons.    which descriptions of r are correct?     number of outer shell  electrons in atoms of r structure of gas r  a 2 diatomic molecules  b 2 single atoms  c 8 diatomic molecules  d 8 single atoms     ",
            "10": "10  \u00a9 ucles 2018 0620/21/o/n/18  24 a student heated copper( ii) carbonate and copper( ii) nitrate in separate test-tubes.    both compounds decomposed.    which row shows the gases produced from each reaction?     copper( ii) carbonate copper( ii) nitrate  a carbon dioxide nitrogen dioxide only  b carbon dioxide oxygen only  c carbon dioxide oxygen and nitrogen dioxide  d oxygen oxygen and nitrogen dioxide     25 metal x reacts with steam but not with cold water.    what is x?  a calcium  b copper  c sodium  d zinc     26 which row shows uses of the metals listed?     aluminium copper mild steel  a aircraft manufacture food containers cutlery  b cutlery electrical wiring chemical plant  c electrical wiring aircraft manufacture cooking utensils  d food containers cooking utensils car bodies      27 aluminium objects do not need protection from corrosion.    iron objects must be protected from corrosion.    why does aluminium resist corrosion?  a aluminium does not form ions easily.  b aluminium does not react with water or air.  c aluminium has a protective oxide layer.  d aluminium is below iron in the reactivity series.    ",
            "11": "11  \u00a9 ucles 2018 0620/21/o/n/18 [turn over  28 which statement describes the role of iron in the haber process?  a it is used as a catalyst.  b it is used as a reducing agent.  c it is used to condense the ammonia gas into a liquid.  d it is used to increase the yield of ammonia.      29 which statement about air pollutants is not correct?  a carbon monoxide is formed from the complete combustion of petroleum.  b lead compounds are formed from some types of petrol.  c oxides of nitrogen are formed from the combustion reactions inside car engines.  d sulfur dioxide is formed from the combustion of coal.      30 argon is a noble gas used to fill light bulbs.    what is the approximate percentage of argon in air?  a 1% b 20% c 79% d 99%     31 the diagrams show experiments involving the rusting of iron.    water boiled to remove the airwater anhydrouscalcium chlorideto dry the airoil iron nailstube q tube r tube p     a student predicted the following results.    1 in tube p, the iron nails rust.  2 in tube q, the iron nails do not rust. 3 in tube r, the iron nails do not rust.    which predictions are correct?  a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "12": "12  \u00a9 ucles 2018 0620/21/o/n/18  32 a diagram of the carbon cycle is shown.    dead organismsanimals plantscarbon dioxide fossil fuelswx x y     which processes are represented by the letters w, x and y?     w x y  a photosynthesis combustion respiration  b photosynthesis respiration combustion  c respiration combustion photosynthesis  d respiration photosynthesis combustion      33 which statement about sulfur or one of its compounds is correct?  a sulfur occurs naturally as the element sulfur.  b sulfur dioxide is used to kill bacteria in drinking water.  c sulfuric acid is a weak acid.  d dilute sulfuric acid is a dehydrating agent.      34 which reaction is endothermic?  a caco 3  \u2192  cao  +  co 2  b cao  +  2hc l  \u2192  cac l 2  +  h 2o  c 2ca  +  o 2  \u2192  2cao  d ca  +  2hc l  \u2192  cac l 2  +  h 2     ",
            "13": "13  \u00a9 ucles 2018 0620/21/o/n/18 [turn over  35 which equation representing a reaction of methane is correct?  a ch 4  +  c l 2  \u2192  ch 3cl  +  hc l  b ch 4  +  c l 2  \u2192  ch 4cl 2  c ch 4  +  c l 2  \u2192  ch 2cl 2  +  h 2  d 2ch 4  +  2c l 2  \u2192  2ch 3cl  +  c l 2  +  h 2      36 which two compounds are molecules which both contain a double bond?  a ethane and ethanoic acid  b ethane and ethanol  c ethene and ethanoic acid  d ethene and ethanol     37 ethanol can be formed by:    1 fermentation  2 reaction between steam and ethene.    which of these processes use a catalyst?     1 2  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     38 when the alcohol ch 3ch 2ch 2oh reacts with the carboxylic acid ch 3ch 2ch 2cooh an ester is  formed.    what is the name and structural formula of this ester?     name structural formula  a butyl propanoate ch 3ch 2cooch 2ch 2ch 2ch 3  b butyl propanoate ch 3ch 2ch 2cooch 2ch 2ch 3  c propyl butanoate ch 3ch 2cooch 2ch 2ch 2ch 3  d propyl butanoate ch 3ch 2ch 2cooch 2ch 2ch 3     ",
            "14": "14  \u00a9 ucles 2018 0620/21/o/n/18  39 a solution of ethanol and water is left to stand in an open beaker in a warm room for three weeks.    which statement explains what happens to the ethanol in the solution?  a the ethanol is dehydrated to ethene.  b the ethanol is hydrolysed to ethene.  c the ethanol is oxidised to ethanoic acid.  d the ethanol is reduced to ethanoic acid.    40 the structure of a polymer is shown.    ch hcch3 ch3ch hcch3 ch3ch hcch3 ch3    which monomer is used to make this polymer?    cch3ch3 ca h hcch3 ch3cb h hcch3 ch3cc hh c ch3ch3 cd hh      ",
            "15": "15    blank page     permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/21/o/n/18  ",
            "16": "16  \u00a9 ucles 2018 0620/21/o/n/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w18_qp_22.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 16 printed pages.  ib18 11_0620_22/4rp  \u00a9 ucles 2018 [turn over     *90428231 84* cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2  multiple choice (extended)  october/november 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.    ",
            "2": "2  \u00a9 ucles 2018 0620/22/o/n/18  1 oxygen and fluorine are gaseous elements next to each other in the periodic table.    under the same conditions of temperature and pressure, oxygen diffuses ..1.. than fluorine  because its ..2.. is less than that of fluorine.    which words correctly complete gaps 1 and 2?     1 2  a faster molecular mass  b faster reactivity  c slower molecular mass  d slower reactivity      2 the diagrams show four pieces of laboratory equipment.    thermomete r stop-clock pipette balance     which equipment is essential to find out if dissolving a salt in water is an exothermic process?     balance pipette stop-clock thermometer  a \u001a \u001a \u001a \u0016  b \u0016 \u001a \u001a \u0016  c \u001a \u0016 \u001a \u0016  d \u0016 \u001a \u0016 \u001a      3 how many neutrons are present in the atom x45 21?  a 21 b 24 c 45 d 66     ",
            "3": "3  \u00a9 ucles 2018 0620/22/o/n/18 [turn over  4 two naturally occurring isotopes of oxygen are 16o and 17o.    which statement is correct?  a both isotopes react with iron to form rust.  b neither isotope reacts with iron to form rust.  c only 16o reacts with iron to form rust.  d only 17o reacts with iron to form rust.     5 how many electrons are used to form covalent bonds in a molecule of methanol, ch 3oh?  a 5 b 6 c 8 d 10     6 potassium bromide and methanol are both compounds.    their melting points are different.    which row is correct?     substance with the  higher melting point reason why the melting points are different  a   methanol   the attractive forces between oppositely charged ions  is greater than the attractive forces between molecules  b   methanol   the attractive forces between molecules is greater  than the attractive forces between oppositely charged ions  c   potassium bromide   the attractive forces between oppositely charged ions  is greater than the attractive forces between molecules  d   potassium bromide   the attractive forces between molecules is greater  than the attractive forces between oppositely charged ions      7 which gas sample contains the smallest number of molecules?  a 4  g of helium  b 16  g of oxygen  c 28  g of carbon monoxide  d 28  g of nitrogen    ",
            "4": "4  \u00a9 ucles 2018 0620/22/o/n/18  8 the equation for the reaction between calcium carbonate and dilute nitric acid is shown.    caco 3(s)  +  2hno 3(aq)  \u2192  ca(no 3)2(aq)  +  co 2(g)  +  h 2o(l)    25  g of calcium carbonate is reacted with an excess of dilute nitric acid.    which mass of calcium nitrate and which volume of carbon dioxide is produced at room temperature and pressure?     mass of  calcium nitrate  / g volume of  carbon dioxide  / dm3  a 29   6  b 29 12  c 41   6  d 41 12     9 the formulae of some ions are shown.    positive ion negative ion  ti4+ po 43\u2013  al 3+ so 42\u2013  mg2+ no 3\u2013  k+ c l \u2013    which formula is not correct?  a a l 3(so 4)2 b k 3po 4 c mg(no 3)2 d tic l 4     ",
            "5": "5  \u00a9 ucles 2018 0620/22/o/n/18 [turn over  10 concentrated aqueous copper( ii) chloride is electrolysed using copper electrodes as shown.    +\u2013copper electrodes aqueous copper( ii) chloridepower supply     what happens to the mass of each electrode during this process?     positive electrode negative electrode  a decreases decreases  b decreases increases  c increases decreases  d increases increases     ",
            "6": "6  \u00a9 ucles 2018 0620/22/o/n/18  11 the diagram shows a circuit used to electrolyse aqueous copper( ii) sulfate.    +\u2013   2134 copper electrodes aqueous copper( ii) sulfatepower supply +\u2013     which arrows indicate the movement of the copper ions in the electrolyte and of the electrons in  the external circuit?     copper ions electrons  a 1 3  b 1 4  c 2 3  d 2 4      12 hydrogen peroxide, h\u2013o\u2013o\u2013h, decomposes to form water and oxygen.    2h2o2(g)  \u2192  2h 2o(g)  +  o 2(g)    the bond energies are shown in the table. the reaction is exothermic.    bond bond energy  in kj  / mol  o\u2013h +460  o\u2013o +150  o=o +496    what is the energy change for the reaction?  a \u2013346  kj / mol b \u2013196  kj / mol c +196  kj / mol d +346  kj / mol     ",
            "7": "7  \u00a9 ucles 2018 0620/22/o/n/18 [turn over  13 the equation for the formation of ammonia is shown.    n2  +  3h 2  \u2192  2nh 3    the energy level diagram for the reaction is shown.    energy progress of reactionenergy changen2  +  3h2 2nh3total energy released = \u2013342  kj / molactivation energy = +250  kj / mol     what is the energy change for the reaction?  a \u2013592  kj / mol  b \u201392  kj / mol  c +92  kj / mol  d +592  kj / mol      14 the rate of reaction between magnesium ribbon and 2  mol  / dm3 hydrochloric acid at 25  \u00b0c to  produce hydrogen gas is measured.    in another experiment, either the concentration of  the hydrochloric acid or the temperature is  changed. all other conditions are kept the same.    which conditions increase the rate of reaction?  a 1  mol  / dm3 hydrochloric acid at 25  \u00b0c  b 2  mol  / dm3 hydrochloric acid at 10  \u00b0c  c 2  mol  / dm3 hydrochloric acid at 20  \u00b0c  d 3  mol  / dm3 hydrochloric acid at 25  \u00b0c     ",
            "8": "8  \u00a9 ucles 2018 0620/22/o/n/18  15 methanol is prepared by the reversible reaction shown.    co(g)  +  2h 2(g)    ch 3oh(g)    the forward reaction is exothermic.    which conditions produce the highest equilibrium yield of methanol?     temperature pressure  a high high  b high low  c low high  d low low      16 the thermite reaction can be used to produce iron from iron( iii) oxide.    the equation for the reaction is shown.    2a l  +  fe 2o3  \u2192  2fe  +  a l 2o3    which statements about this reaction are correct?    1 aluminium is the oxidising agent.  2 aluminium is less reactive than iron. 3 electrons are transferred from aluminium to iron.  4 the iron in the iron( iii) oxide is reduced.    a 1 and 3 b 1 and 4 c 2 and 3 d 3 and 4    17 in which row are the oxides correctly identified?     acidic basic  a magnesium oxide, calcium oxide su lfur dioxide, carbon dioxide  b magnesium oxide, sulfur dioxide carbon dioxide, calcium oxide  c sulfur dioxide, carbon dioxide calcium oxide, magnesium oxide  d sulfur dioxide, magnesium oxide calcium oxide, carbon dioxide     ",
            "9": "9  \u00a9 ucles 2018 0620/22/o/n/18 [turn over  18 when dilute sulfuric acid is added to solid x, a colourless solution is formed and a gas is  produced.    what is x?  a copper( ii) oxide  b sodium oxide  c copper( ii) carbonate  d sodium carbonate      19 a few drops of methyl orange are added to a reaction mixture.    during the reaction, a gas is produced and the methyl orange turns from red to orange.    what are the reactants?  a aqueous sodium hydroxide and ammonium chloride  b aqueous sodium hydroxide and calcium carbonate  c dilute hydrochloric acid and magnesium  d dilute hydrochloric acid and aqueous sodium hydroxide    20 some general rules for the solubility of salts in water are listed.    \u25cf carbonates are insoluble (except ammonium carbonate, potassium carbonate and  sodium carbonate).  \u25cf chlorides are soluble (except lead( ii) chloride and silver chloride).  \u25cf nitrates are soluble.  \u25cf sulfates are soluble (except barium sulfate, calcium sulfate and lead( ii) sulfate).    which substances produce an insoluble salt when aqueous solutions of them are mixed?  a barium chloride and magnesium nitrate  b calcium chloride and ammonium nitrate  c silver nitrate and zinc chloride  d sodium carbonate and potassium sulfate    ",
            "10": "10  \u00a9 ucles 2018 0620/22/o/n/18  21 elements in group i of the periodic table react with water.    which row describes the products made in the reaction and the trend in reactivity of the elements?     products trend in reactivity  a metal hydroxide and hydrogen less reactive down the group  b metal hydroxide and hydrogen more reactive down the group  c metal oxide and hydrogen less reactive down the group  d metal oxide and hydrogen more reactive down the group     22 the equation shows the reaction between a halogen and aqueous bromide ions.    x 2 + 2br\u2013 \u2192 2x\u2013 + br 2   ..1.. ..2.. ..3..    which words complete gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     23 an inert gas r is used to fill weather balloons.    which descriptions of r are correct?     number of outer shell  electrons in atoms of r structure of gas r  a 2 diatomic molecules  b 2 single atoms  c 8 diatomic molecules  d 8 single atoms     ",
            "11": "11  \u00a9 ucles 2018 0620/22/o/n/18 [turn over  24 heating copper( ii) carbonate produces copper( ii) oxide and carbon dioxide.    heating the copper( ii) oxide formed with carbon produces copper.    which processes are involved in this conversion of copper( ii) carbonate to copper?  a sublimation followed by oxidation  b sublimation followed by reduction  c thermal decomposition followed by oxidation  d thermal decomposition followed by reduction     25 four metals, w, x, y and z, are separately reacted with water and dilute hydrochloric acid.    the results are shown.     metal  w x y z  reaction with water   fizzes   no reaction   fizzes  vigorously no reaction    reaction with dilute  hydrochloric acid fizzes   no reaction   fizzes  violently fizzes      what is the order of reactivity of the four  metals starting with the least reactive?     least reactive  most reactive  a x w z y  b x z w y  c y w z x  d y z w x      26 which statement about the uses of metals is not correct?  a aluminium is used in aircraft because of it s strength and good electrical conductivity.  b copper is used in electrical wiring because of its good electrical conductivity.  c stainless steel resists corrosion and is used to make cutlery.  d transition elements are often used as catalysts.    ",
            "12": "12  \u00a9 ucles 2018 0620/22/o/n/18  27 bauxite contains aluminium oxide.    aluminium is extracted from aluminium oxide by electrolysis.    why is cryolite added to the electrolytic cell used to extract aluminium?  a cryolite prevents the carbon anodes being burned away.  b cryolite removes impurities from the bauxite.  c cryolite increases the rate at which aluminium ions are discharged.  d molten cryolite dissolves the aluminium oxide.    28 which statement about the haber process is correct?  a the hydrogen used is obtained from the air.  b the nitrogen used is obtained from nitrates in the soil.  c nitrogen reacts with hydrogen to make ammonia.  d the reaction takes place at room temperature and pressure.    29 which statements about sulfur dioxide pollution are correct?    1 it increases the ph of rivers.  2 it damages limestone buildings.  3 it causes respiratory problems.    a 1 only b 2 only c 1 and 3 d 2 and 3    30 argon is a noble gas used to fill light bulbs.    what is the approximate percentage of argon in air?  a 1% b 20% c 79% d 99%    ",
            "13": "13  \u00a9 ucles 2018 0620/22/o/n/18 [turn over  31 the diagrams show experiments involving the rusting of iron.    water boiled to remove the airwater anhydrouscalcium chlorideto dry the airoil iron nailstube q tube r tube p     a student predicted the following results.    1 in tube p, the iron nails rust.  2 in tube q, the iron nails do not rust. 3 in tube r, the iron nails do not rust.    which predictions are correct?  a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     32 in the carbon cycle, which two processes add carbon dioxide to the atmosphere?  a combustion and carbonate formation  b combustion and photosynthesis  c combustion and respiration  d respiration and photosynthesis     33 which statement about sulfur or one of its compounds is correct?  a sulfur occurs naturally as the element sulfur.  b sulfur dioxide is used to kill bacteria in drinking water.  c sulfuric acid is a weak acid.  d dilute sulfuric acid is a dehydrating agent.    ",
            "14": "14  \u00a9 ucles 2018 0620/22/o/n/18  34 what is not a use of lime?  a it is used as a bleach in the manufacture of wood pulp.  b it is used to desulfurise flue gases.  c it is used to neutralise acidic industrial waste.  d it is used to treat acidic soil.      35 which equation representing a reaction of methane is correct?  a ch 4  +  c l 2  \u2192  ch 3cl  +  hc l  b ch 4  +  c l 2  \u2192  ch 4cl 2  c ch 4  +  c l 2  \u2192  ch 2cl 2  +  h 2  d 2ch 4  +  2c l 2  \u2192  2ch 3cl  +  c l 2  +  h 2     36 which two compounds are molecules which both contain a double bond?  a ethane and ethanoic acid  b ethane and ethanol  c ethene and ethanoic acid  d ethene and ethanol     37 ethanol can be formed by:    1 fermentation  2 reaction between steam and ethene.    which of these processes use a catalyst?     1 2  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/22/o/n/18 38 ethanol is manufactured from ethene.    what is an advantage of this process?  a it is a continuous process.  b it has high labour costs.  c it needs high temperature and pressure.  d it uses non-renewable materials.     39 which reaction can be used to make ethanoic acid?  a oxidation of ethanol  b oxidation of ethene  c reduction of ethanol  d reduction of ethene    40 the structure of an addition polymer is shown.    c hoh c hh c hoh c hh c hoh c hh     which monomer is used to make this polymer?    c hh hoha c hc hoh h hohbc cc ohhh hcc hooh h hd      ",
            "16": "16  \u00a9 ucles 2018 0620/22/o/n/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w18_qp_23.pdf": {
            "1": "  the syllabus is approved for use in england, wales and northern ir eland as a cambridge international level 1/level 2 certificat e.  this document consists of 15 printed pages and 1 blank page.  ib18 11_0620_23/5rp  \u00a9 ucles 2018 [turn over     *9404328925 * cambridge international examinations  cambridge international general certificate of secondary education       chemistry 0620/23     paper 2  multiple choice (extended)  october/november 2018       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.    ",
            "2": "2  \u00a9 ucles 2018 0620/23/o/n/18  1 gases are separated from liquid air by fractional distillation. the boiling points of four gases are  shown.    which gas is both monatomic and a liquid at \u2013200  \u00b0c?     gas boiling  point  / \u00b0c  a argon \u2013186  b helium \u2013269  c neon \u2013246  d nitrogen \u2013196      2 the diagrams show four pieces of laboratory equipment.    thermomete r stop-clock pipette balance     which equipment is essential to find out if dissolving a salt in water is an exothermic process?     balance pipette stop-clock thermometer  a \u001a \u001a \u001a \u0016  b \u0016 \u001a \u001a \u0016  c \u001a \u0016 \u001a \u0016  d \u0016 \u001a \u0016 \u001a      3 which statement describes isotopes?  a isotopes of the same element have different electron arrangements.  b isotopes of the same element have different nuclear charges.  c isotopes of the same element have nuclei with masses that are the same.  d isotopes of the same element have the same number of protons.     ",
            "3": "3  \u00a9 ucles 2018 0620/23/o/n/18 [turn over  4 x and y are both atoms.    x and y have the same chemical properties as each other.    which row describes the atomic structures of x and y?     x y  protons neutrons electrons protons neutrons electrons  a 6 6 6 6 6 7  b 6 6 6 6 8 6  c 6 6 6 16 16 16  d 7 6 7 6 6 7      5 which covalent molecule contains two atoms bonded together by exactly four shared electrons?  a n 2 b c 3h8 c ch 3oh d ch 3cooh      6 the formula of ammonia is nh 3.    which statement about a molecule of ammonia is correct?  a the bonding in a molecule of ammonia is ionic.  b the nitrogen atom has a noble gas configuration, the hydrogen atoms do not.  c the nitrogen atom shares all of its electrons with hydrogen atoms.  d there are six shared electrons in a molecule of ammonia.      7 which gas sample has the greatest mass?  a 5.0  moles of c l 2  b 10.0  moles of o 2  c 15.0  moles of n 2  d 20.0  moles of h 2     8 which sample of magnesium chloride, mgc l  2, contains the same number of moles as   69.6  g of potassium sulfate, k 2so 4?  a 19.0  g b 28.5  g c 38.0  g d 47.5  g      9 iron( iii) chromate is a yellow solid. it contains the ions fe3+ and cro 42\u2013.    what is the formula of iron( iii) chromate?  a fecro 4 b fe 3(cro 4)2 c fe 2cro 4 d fe 2(cro 4)3 ",
            "4": "4  \u00a9 ucles 2018 0620/23/o/n/18  10 electrolysis of copper( ii) sulfate can be done using either carbon electrodes or copper  electrodes.    which statement describes what happens at the positive electrode?  a copper is deposited if the electrode is made from carbon.  b copper is deposited if the electrode is made from copper.  c oxygen gas is produced if the electrode is made from carbon.  d oxygen gas is produced if the electrode is made from copper.     11 the diagram shows a circuit used to electrolyse aqueous copper( ii) sulfate.    +\u2013   2134 copper electrodes aqueous copper( ii) sulfatepower supply +\u2013     which arrows indicate the movement of the copper ions in the electrolyte and of the electrons in the external circuit?     copper ions electrons  a 1 3  b 1 4  c 2 3  d 2 4     ",
            "5": "5  \u00a9 ucles 2018 0620/23/o/n/18 [turn over  12 ethene burns in oxygen to form carbon dioxide and water vapour.    cchh hh  +  3 o=o  \u2192  2 o=c=o  +  2 h\u2013o\u2013h    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c=c +610  c\u2013h +410  o=o +497  c=o +805  o\u2013h +460    what is the energy change for the reaction?  a \u20132959  kj / mol  b \u20132313  kj / mol  c \u20131319  kj / mol  d \u2013399  kj / mol    ",
            "6": "6  \u00a9 ucles 2018 0620/23/o/n/18  13 the equation for the formation of ammonia is shown.    n2  +  3h 2  \u2192  2nh 3    the energy level diagram for the reaction is shown.    energy progress of reactionenergy changen2  +  3h2 2nh3total energy released = \u2013342  kj / molactivation energy = +250  kj / mol     what is the energy change for the reaction?  a \u2013592  kj / mol  b \u201392  kj / mol  c +92  kj / mol  d +592  kj / mol     14 dilute hydrochloric acid reacts with 1  g of limestone.    which conditions produce the fastest rate of reaction?  a 2 mol  / dm3 hydrochloric acid and a single lump of limestone  b 4 mol  / dm3 hydrochloric acid and a single lump of limestone  c 4 mol  / dm3 hydrochloric acid and small pieces of limestone  d 4 mol  / dm3 hydrochloric acid and powdered limestone    ",
            "7": "7  \u00a9 ucles 2018 0620/23/o/n/18 [turn over  15 the reversible reaction between methane and steam is shown.    ch 4(g)  +  h 2o(g)    co(g)  +  3h 2(g)    the forward reaction is endothermic.    which changes in pressure and temperature move the equilibrium to the right?     pressure temperature  a decrease decrease  b decrease increase  c increase decrease  d increase increase      16 the equation for the reaction between zinc and copper( ii) oxide is shown.    zn  +  cuo  \u2192  zno  +  cu    which row shows the oxidising agent and the reducing agent?     oxidising agent reducing agent  a cuo cu  b cuo zn  c zn cuo  d zn zno      17 the results of some experiments with sulfur dioxide are shown.    experiment description result  1 mix with dilute hydrochloric acid does not react  2 mix with concentrated sodium hydroxide a salt forms  3   add universal indicator   universal indicator  turns purple  4   add acidified aqueous  potassium manganate( vii) purple solution  turns colourless    which results are correct?  a 1, 2 and 4 b 2, 3 and 4 c 1 and 2 only d 3 and 4 only     ",
            "8": "8  \u00a9 ucles 2018 0620/23/o/n/18  18 a white precipitate is produced when small amounts of two colourless solutions are mixed  together.    which pairs of solutions produce a white precipitate?    1 sodium hydroxide and zinc nitrate  2 sodium hydroxide and aluminium chloride 3 barium chloride and sulfuric acid 4 acidified barium nitrate and potassium sulfate    a 1, 2, 3 and 4  b 1, 2 and 4 only  c 1 and 2 only  d 2 only      19 solution q is warmed with ammonium chloride.    in a separate experiment, solution q is added to methyl orange.    which observations show that solution q is basic?     warmed with  ammonium chloride added to   methyl orange  a gas is produced turns red  b gas is produced turns yellow  c no reaction turns red  d no reaction turns yellow      20 some general rules for the solubility of salts in water are listed.    \u25cf carbonates are insoluble (except ammonium carbonate, potassium carbonate and  sodium carbonate).  \u25cf chlorides are soluble (except lead( ii) chloride and silver chloride).  \u25cf nitrates are soluble.  \u25cf sulfates are soluble (except barium sulfate, calcium sulfate and lead( ii) sulfate).    which substances produce an insoluble salt when aqueous solutions of them are mixed?  a barium chloride and magnesium nitrate  b calcium chloride and ammonium nitrate  c silver nitrate and zinc chloride  d sodium carbonate and potassium sulfate ",
            "9": "9  \u00a9 ucles 2018 0620/23/o/n/18 [turn over  21 elements in group i of the periodic table react with water.    which row describes the products made in the reaction and the trend in reactivity of the elements?     products trend in reactivity  a metal hydroxide and hydrogen less reactive down the group  b metal hydroxide and hydrogen more reactive down the group  c metal oxide and hydrogen less reactive down the group  d metal oxide and hydrogen more reactive down the group     22 the equation shows the reaction between a halogen and aqueous bromide ions.    x 2 + 2br\u2013 \u2192 2x\u2013 + br 2   ..1.. ..2.. ..3..    which words complete gaps 1, 2 and 3?     1 2 3  a chlorine brown colourless  b chlorine colourless brown  c iodine brown colourless  d iodine colourless brown     23 an inert gas r is used to fill weather balloons.    which descriptions of r are correct?     number of outer shell  electrons in atoms of r structure of gas r  a 2 diatomic molecules  b 2 single atoms  c 8 diatomic molecules  d 8 single atoms     ",
            "10": "10  \u00a9 ucles 2018 0620/23/o/n/18  24 heating copper( ii) carbonate produces copper( ii) oxide and carbon dioxide.    heating the copper( ii) oxide formed with carbon produces copper.    which colour changes are observed during these reactions?  a green \u2192 black \u2192 brown  b green \u2192 white \u2192 brown  c blue \u2192 black \u2192 silver  d blue \u2192 white \u2192 brown     25 calcium reacts with cold water to produce hydrogen.    lead reacts slowly when heated in air to form an  oxide but has almost no reaction with steam.    silver does not react with either air or water.    zinc reacts when heated with steam to produce hydrogen.    what is the order of reactivity starting with the least reactive?     least reactive   most reactive  a calcium lead zinc silver  b calcium zinc lead silver  c silver lead zinc calcium  d silver zinc lead calcium     26 which row describes the use of a metal and the property upon which the use depends?     metal use property  a aluminium aircraft bodies aluminium is a heat conductor  b aluminium cooking utensils aluminium has a low density  c copper cooking utensils copper has a high density  d copper electrical wiring copper is a good conductor of electricity     27 which statement about the manufacture of aluminium by electrolysis is correct?  a aluminium ions are oxidised to aluminium by gaining electrons.  b aluminium is extracted from its ore hematite.  c molten cryolite is used to dissolve the aluminium oxide.  d oxygen is formed at the negative electrode.   ",
            "11": "11  \u00a9 ucles 2018 0620/23/o/n/18 [turn over  28 ammonia is manufactured by the haber process from nitrogen and hydrogen.    which row gives the main sources of these two gases?     hydrogen nitrogen  a air air  b air natural gas  c natural gas air  d natural gas natural gas      29 which equation represents the incomplete combustion of propane, c 3h8?  a 2c 3h8  +  7o 2  \u2192  6co  +  8h 2o  b c 3h8  +  5o 2  \u2192  3co 2  +  4h 2o  c 2c 3h8  +  11o 2  \u2192  6co  +  16h 2o  d c 3h8  +  7o 2  \u2192  3co 2  +  8h 2o     30 argon is a noble gas used to fill light bulbs.    what is the approximate percentage of argon in air?  a 1% b 20% c 79% d 99%     ",
            "12": "12  \u00a9 ucles 2018 0620/23/o/n/18  31 the diagrams show experiments involving the rusting of iron.    water boiled to remove the airwater anhydrouscalcium chlorideto dry the airoil iron nailstube q tube r tube p     a student predicted the following results.    1 in tube p, the iron nails rust.  2 in tube q, the iron nails do not rust. 3 in tube r, the iron nails do not rust.    which predictions are correct?  a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     32 which statement about the carbon cycle is correct?  a animals and plants need carbon dioxide for respiration.  b combustion of plants and natural gas produces carbon dioxide.  c plants produce glucose from carbon dioxide and oxygen.  d oxygen is produced by both animals and plants.     33 which statement about sulfur or one of its compounds is correct?  a sulfur occurs naturally as the element sulfur.  b sulfur dioxide is used to kill bacteria in drinking water.  c sulfuric acid is a weak acid.  d dilute sulfuric acid is a dehydrating agent.    ",
            "13": "13  \u00a9 ucles 2018 0620/23/o/n/18 [turn over  34 which equation represents the formation of lime?  a caco 3  \u2192  cao  +  co 2  b cao  +  h 2o  \u2192  ca(oh) 2  c ca  +  2h 2o  \u2192  ca(oh) 2  +  h 2  d ca(oh) 2  +  co 2  \u2192  caco 3  +  h 2o    35 which equation representing a reaction of methane is correct?  a ch 4  +  c l 2  \u2192  ch 3cl  +  hc l  b ch 4  +  c l 2  \u2192  ch 4cl 2  c ch 4  +  c l 2  \u2192  ch 2cl 2  +  h 2  d 2ch 4  +  2c l 2  \u2192  2ch 3cl  +  c l 2  +  h 2     36 which two compounds are molecules which both contain a double bond?  a ethane and ethanoic acid  b ethane and ethanol  c ethene and ethanoic acid  d ethene and ethanol    37 ethanol can be formed by:    1 fermentation  2 reaction between steam and ethene.    which of these processes use a catalyst?     1 2  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     ",
            "14": "14  \u00a9 ucles 2018 0620/23/o/n/18  38 sugar can be fermented to produce ethanol.    some of the stages in the process to produce and purify ethanol are listed.    1 leave in a warm place.  2 add yeast. 3 fractionally distil the solution. 4 dissolve the sugar in water. 5 filter to remove the yeast. 6 crush some sugar cane.    what is the correct order of these stages?  a 4 \u2192 6 \u2192 2 \u2192 1 \u2192 5 \u2192 3  b 6 \u2192 4 \u2192 1 \u2192 2 \u2192 5 \u2192 3  c 6 \u2192 4 \u2192 2 \u2192 1 \u2192 3 \u2192 5  d 6 \u2192 4 \u2192 2 \u2192 1 \u2192 5 \u2192 3    39 which statement about ethanoic acid is correct?  a it contains a \u2013c 2h5 group.  b it is a strong acid.  c it is formed by the reduction of ethanol.  d it reacts with alcohols to form esters.     40 the structure of a polymer is shown.    ch hccl clch hccl clch hccl cl    which monomer is used to make this polymer?    cclcl c h hc ccl cl clcl ch ha ccl clc hhd b c ccl cl clcl chh hc hc      ",
            "15": "15    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  international examinations copyright acknow ledgements booklet. this is produced for each  series of examinations and is freely a vailable to download at  www.cie.org.uk after the live examination series.    cambridge international examinations is part of the cambridge as sessment group. cambridge assessment is the brand name of unive rsity of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.    \u00a9 ucles 2018 0620/23/o/n/18  ",
            "16": "16  \u00a9 ucles 2018 0620/23/o/n/18   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w18_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31 paper 3  theory (core) october/november 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib18 11_0620_31/3rp\u00a9 ucles 2018 *2119876214* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/31/o/n/18 \u00a9 ucles 2018 1 (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td\tand\te,\tare\tshown. a bcd e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\tstructures. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\tstate\twhich\tstructure,\ta,\tb,\tc,\td or e,\trepresents:  (i)\t\tan\tatom\tof\ta\tmetallic\telement\t \t ...  [1]  (ii)\t\tan\tatom\twith\ta\tproton\tnumber\tof\t13\t\t .   [1]  (iii)\t\tan\tatom\tof\tphosphorus\t \t .   [1]  (iv)\t\tan\tatom\twith\tonly\ttwo shells of electrons \t .   [1]  (v)\t\tan\tatom\twhich\tforms\ta\tstable\tion\twith\ta \tsingle\tnegative\tcharge.\t \t.   [1]  (b)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\tthe\tcarbon\tatom\t and\tpotassium\tion\tshown. number\tof electronsnumber\tof neutronsnumber\tof protons 14c6 6 40k+ 19 21 \t [3] \t [total:\t8]",
            "3": "3 0620/31/o/n/18 \u00a9 ucles 2018 [turn over 2 (a)\t\tthe\ttable\tshows\tthe\tions\tpresent\tin\ta\t1000\t cm3\tsample\tof\tblood\tplasma. ion\tpresent formula\tof\tionmass\tpresent\tin\tthe 1000\tcm3\tsample\t/\tg sodium na+3.25 potassium k+0.16 calcium ca2+0.10 magnesium mg2+0.04 chloride cl \u20133.65 hydrogencarbonate hco3\u20131.50 phosphate po43\u20130.64 sulfate so42\u20130.10 \t\tanswer\tthese\tquestions\tusing\tonly\tinformation\tfrom\tthe\ttable.  (i)\t\twhich\tpositive\tion\tis\tpresent\tin\tthe\tlowest\tconcentration?  \t ...   [1]  (ii)\t\tgive\tthe\tname\tof\tthe\tcompound\tformed \tfrom\tk+\tand\tcl \u2013\tions.  \t ...   [1]  (iii)\t\tcalculate\tthe\tmass\tof\tpotassium\tions\tpresent\tin\t200\t cm3\tof\tthis\tblood\tplasma. \t mass\tof\tpotassium\tions\t=\t..\tg\t\t[1]  (iv)\t\twhen\tthe\t1000\tcm3\tsample\tof\tblood\tplasma\tis\tcrystallised,\t several\tcompounds\t are\tformed. \t \tsuggest\tthe\tname\tof\tthe\tcompound\twhich\tforms\tthe\tgreatest\tmass\tof\tcrystals.  \t ...   [1]  (b)\t\tdescribe\ta\ttest\tfor\tpotassium\tions.  test \t.  result \t..  [2]",
            "4": "4 0620/31/o/n/18 \u00a9 ucles 2018  (c)\t\tblood\tplasma\talso\tcontains\tproteins. \t\tproteins\tare\tpresent\tin\tfood.   which one\tof\tthe\tfollowing\tsubstances\tis\talso\tpresent\tin\tfood? \t\tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. carbohydrate        hematite        poly(ethene)        terylene  [1]  (d)\t\tcompound\t s\tis\tone\tof\tthe\tmonomer\tunits\tused\tto\tmake\tproteins.\tits\tstructure\tis\tshown. h2nc hcompound s ch2cooh oh  (i)\t\ton\tthe\tstructure,\tdraw\ta\tcircle\taround\tthe\talcohol\tfunctional\tgroup.\t [1]  (ii)\t\tdeduce\tthe\tmolecular\t formula\tof\tcompound\t s\tshowing\tthe\tnumber\tof\tcarbon,\thydrogen,\t oxygen\tand\tnitrogen\tatoms.  \t ...   [1] \t [total:\t9]",
            "5": "5 0620/31/o/n/18 \u00a9 ucles 2018 [turn over 3 (a)\t\tthe\tapparatus\tused\tfor\tdistillation\tis\tshown. . . aqueous copper( ii) sulfatethermometer flask  (i)\t\tcomplete\tthe\tbox\tto\tname\tthe\tapparatus.\t [1]  (ii)\t\tdescribe\tand\texplain\thow\tthe\twater\tis\tseparated\t from\tthe\taqueous\tcopper( ii)\tsulfate\tby\t distillation.  \t .  \t .  \t .  \t .  \t ... \t\t[3]  (b)\t\ta\tsample\tof\tsolid\thydrated\tcopper( ii)\tsulfate\tis\theated\tgently\tin\ta\ttest-tube. cuso4.5h2o    cuso4\t\t+\t\t5h2o  hydrated \t copper( ii)\tsulfate \t\tsolid\thydrated\tcopper( ii)\tsulfate\tis\tblue. \t\tdescribe\t two\tobservations\t when\tthe\tsample\tof\tsolid\thydrated\tcopper( ii)\tsulfate\tis\theated\t gently\tin\ta\ttest-tube.  1 \t.  2 \t.  [2]",
            "6": "6 0620/31/o/n/18 \u00a9 ucles 2018  (c)\t\tcopper( ii)\tsulfate\tcan\tbe\tprepared\t by\theating\tan\texcess\tof\tcopper( ii)\toxide\twith\tdilute\t sulfuric\tacid.  (i)\t\tcomplete\tthe\tchemical\tequation\tfor\tthis \treaction. cuo  +  h2so4    cuso4\t\t+\t\t.  [1]  (ii)\t\twhat\tmethod\tis\tused\tto\tseparate\tthe\texcess\tcopper( ii)\toxide\tfrom\tthe\tsolution?  \t ...   [1]  (d)\t\tcopper( ii)\toxide\tcan\tbe\treduced\tby\thydrogen. cuo  +  h2    cu  +  h2o \t\thow\tdoes\tthis\tequation\tshow\tthat\tcopper( ii)\toxide\tis\treduced?  \t  \t..   [1]  (e)\t\tthe\tchemical\tequation\tfor\tthe\treaction\tof\tcopper\twith\tconcentrated\tnitric\tacid\tis\tshown. cu\t\t+\t\t4hno3  \t\tcu(no3)2  +  2no2  +  2h2o \t\tcomplete\tthe\tword\tequation\tfor\tthis\treaction. copper +nitric acid... ...+..+...  [2] \t [total:\t11]",
            "7": "7 0620/31/o/n/18 \u00a9 ucles 2018 [turn over 4 (a)\t\tthe\tstructure\tof\tcitraconic\tacid\tis\tshown. c c h coohcooh h3c \t\tcitraconic\tacid\tis\tan\tunsaturated\tcompound.  (i)\t\twhat\tfeature\tof\tthe\tstructure\tof\tcitraconic\tacid\tshows\tthat\tit\tis\tunsaturated?  \t ...   [1]  (ii)\t\tdescribe\ta\t test\tfor\tan\tunsaturated\tcompound.  test \t ..  result \t ...  [2]  (b)\t\tethanoic\tacid\thas\ta\tcarboxylic\tacid\tfunctional\tgroup. \t\tdraw\tthe\tstructure\tof\tthe\tcarboxylic\t acid\tfunctional\t group.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\t bonds.  [1]  (c)\t\tcomplete\tthe\tdefinition\tof\ta\thomologous\tseries\tusing\twords\tfrom\tthe\tlist. chemical       compounds       elements       functional       hydrocarbons       physical \t\ta\thomologous\t series\tis\ta\tfamily\tof\tsimilar\t..\t with\tsimilar\t..\t     properties\tdue\tto\tthe\tpresence\tof\tthe\tsame\t..\tgroup.\t [3]",
            "8": "8 0620/31/o/n/18 \u00a9 ucles 2018  (d)\t\tthe\tgraph\tshows\thow\tthe\tph\tof\ta\tdilute\tacid\tin\ta\tconical\tflask\tchanges\tas\taqueous\t sodium\thydroxide\tis\tadded\tto\tit. 14 12 10 8 6 4 2 0 05 10 15 20 volume of aqueous sodium hydroxide added  / cm325 30 35ph  (i)\t\tdescribe\thow\tthe\tph\tchanges\tas\tthe\taqueous\tsodium\thydroxide\tis\tadded.  \t .  \t .  \t ...   [2]  (ii)\t\twhat\tis\tthe\tph\tof\tthe\tdilute\tacid\tbefore\t the\taqueous\tsodium\thydroxide\tis\tadded?  \t ...   [1]  (iii)\t\twhat\tvolume\tof\taqueous\tsodium\thydroxide\thas\tbeen\tadded\twhen\tthe\tph\treaches\tph\t 7?  \t ...   [1] \t [total:\t11]",
            "9": "9 0620/31/o/n/18 \u00a9 ucles 2018 [turn over 5 (a)\t\tsome\tof\tthe\tchanges\tof\tstate\tof\twater\tare\tshown. ice waterwater vapourp freezing qevaporation  (i)\t\tgive\tthe\tnames\tof\tthe\tchanges\tof\tstate\trepresented\tby\t p\tand\tq.  p \t .  q \t .  [2]  (ii)\t\tuse\tthe\tkinetic\tparticle\tmodel\tto\tdescribe\tthe\tseparation\t and\tmotion\tof\tthe\tparticles\tin\t water\twhen\tit\tis:  \u25cfa\tliquid  \t .  \t .  \u25cfa\tvapour  \t .  \t . \t [4]  (b)\t\twhen\tlithium\treacts\twith\twater,\thydrogen\tis\tproduced\tand\tthe\tsolution\tformed\tis\talkaline.  (i)\t\tbalance\tthe \tchemical\tequation\tfor\tthis\treaction. .li\t\t+\t\t.h2o  \t\t2lioh\t\t+\t\th2  [2]  (ii)\t\tgive\tthe\tname\tof\tthe\tproduct\twhich\tcauses\tthe\tsolution\tto\tbe\talkaline.  \t ...   [1]",
            "10": "10 0620/31/o/n/18 \u00a9 ucles 2018  (c)\t\tdilute\tsulfuric\tacid\tcan\tbe\telectrolysed\tusing\tthe\tapparatus\tshown. power supplydilute sulfuric acid graphite electrodes +\u2013  (i)\t\tstate\tthe\tproducts\tof\tthis\telectrolysis\tat: \t the\tpositive\telectrode\t(anode)\t \t  \t the\tnegative\telectrode\t(cathode).\t \t ...  [2]  (ii)\t\twhat\tobservation\tis\tmade\tat\tthe\telectrodes?  \t ...   [1]  (iii)\t\tsuggest\tone\treason\twhy\tgraphite\tis\tused\tfor\tthe\telectrodes\trather\tthan\tmagnesium.  \t ...   [1] \t [total:\t13]",
            "11": "11 0620/31/o/n/18 \u00a9 ucles 2018 [turn over 6 (a)\t\tthe\tdiagrams\tshow\tthe\tstructures\tof\tfour\tsubstances,\tr,\ts,\tt\tand\tu. cc cccc ccccccc ccc cc cccc cc c ccc cc ccccc ccczn zn zn zn zn znzn zn zn zn znna+br \u2013na+ na+br \u2013na+br \u2013br \u2013na+p pp prs tu  (i)  which two\tof\tthese\tsubstances,\tr,\ts,\tt or u,\tare\tcovalently\tbonded? \t \tand\t\t ...   [2]  (ii)  which two\tof\tthese\tsubstances,\tr,\ts,\tt or u,\tconduct\telectricity\twhen\tsolid? \t \tand\t\t ...   [2]  (iii)\t\twhich\tsubstance,\tr,\ts,\tt or u,\thas\tthe\tlowest\tmelting\tpoint?\t \t.   [1]  (iv)  which one\tof\tthese\tsubstances,\tr,\ts,\tt or u,\tis\tsoluble\tin\twater?\t \t..   [1]  (b)\t\tphosphorus\tburns\tin\toxygen\tto\tform\tphosphorus( v)\toxide.  (i)\t\tbalance\tthe \tchemical\tequation\tfor\tthis\treaction.  p4\t\t+\t\t5o2  \t\t.p2o5 [1]  (ii)\t\tis\tphosphorus( v)\toxide\tan\tacidic\toxide\t or\ta\tbasic\toxide? \t \tgive\ta\treason\tfor\tyour\tanswer.  \t .  \t ...   [1]  (c)\t\tphosphate\tions\tare\tpresent\tin\tmany\tfertilisers.  (i)  which one\tof\tthe\tfollowing\tions\tis\talso\tpresent\tin\tmany\tfertilisers? \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. \t ba2+            cu2+            f\u2013            no3\u2013 [1]  (ii)\t\twhy\tdo\tfarmers\tput\tfertilisers\ton\ttheir\tfields?  \t .  \t ...   [1] \t [total:\t10]",
            "12": "12 0620/31/o/n/18 \u00a9 ucles 2018 7 (a)\t\ta\tstudent\tinvestigates\tthe\treaction\tof\tcalcium\tcarbonate\twith\tdilute\thydrochloric\tacid. caco3  +  2hcl  \t\tcacl 2  +  co2  +  h2o \t\tthe\tstudent\tmeasures\t the\tmass\tof\tthe\treaction\tmixture\tat\t10\tsecond\tintervals\tusing\tthe\t apparatus\tshown. 250.00  gcalcium carbonatecotton wool dilute hydrochloric acid \t\tthe\tgraph\tshows\tthe\tresults\twhen\t5.0\tg\tof\tcalcium\tcarbonate\t is\tadded\tto\tan\texcess\tof\tdilute\t hydrochloric\tacid. 250 249 248 247 246 01 02 03 04 0 time  / smass  / g 50 60 70 80  (i)\t\tsuggest\twhy\tthe\treaction\tmixture\tdecreases\tin\tmass\tas\tthe\treaction\tproceeds.  \t ...   [1]  (ii)\t\tcalculate\tthe\tloss\tof\tmass\tin\tgrams\twhen\tthe\treaction\tis\tcomplete. \t loss\tin\tmass\t=\t..\tg\t\t[1]",
            "13": "13 0620/31/o/n/18 \u00a9 ucles 2018 [turn over  (iii)\t\tthe\texperiment\t is\trepeated\tusing\tdilute\thydrochloric\t acid\tof\ttwice\tthe\tconcentration.\t all\t other\tconditions\tare\tkept\tthe\tsame.   on the grid,\t draw\ta\tgraph\tto\tshow\thow\tthe\tmass\tchanges\twith\ttime\tusing\tdilute\t hydrochloric\tacid\tof\t twice\tthe\tconcentration.\t [2]  (iv)\t\tthe\toriginal\texperiment\tis\trepeated\tat\tthree\tdifferent\ttemperatures. \t \tall\tother\tconditions\tare\tkept\tthe\tsame. \t \tthe\tthree\ttemperatures\tare\t20\t \u00b0c,\t30\t\u00b0c\tand\t40\t \u00b0c. \t \tcomplete\tthe\ttable\tby\twriting\tthe\ttemperatures\tin\tthe\tfirst\tcolumn. temperature in \u00b0cinitial\trate\tof\treaction in\tg\t/\ts 0.16 0.64 0.32  [1]  (b)\t\tcomplete\t the\tsentences\t about\tthe\tuse\tof\tcalcium\tcarbonate\t in\tthe\textraction\t of\tiron\tusing\t words\tfrom\tthe\tlist. bauxite        dioxide        hematite        monoxide        silicon        slag \t\tthe\tmain\tore\tof\tiron\tis\tcalled\t..\t .\tthe\tmain\timpurity\tin\tthe\tiron\tore\tis\t    silicon( iv)\toxide. \t\tcalcium\tcarbonate\t added\tto\tthe\tblast\tfurnace\tdecomposes\t to\tform\tcalcium\toxide     and\tcarbon\t..\t .\tthe\tcalcium\toxide\treacts\twith\tthe\tsilicon( iv)\toxide\tto   form\t..\t. \t [3] \t [total:\t8]",
            "14": "14 0620/31/o/n/18 \u00a9 ucles 2018 8\t\tglass\tcan\tbe\tmade\tby\theating\ta\tmixture\tof\tsand,\tsodium\tcarbonate\t and\tlimestone   (calcium\tcarbonate).  (a)  (i)\t\tcalculate\tthe\trelative\tformula\tmass\tof\tsodium\tcarbonate,\tna2co3. \t \tshow\tall\tyour\tworking. \t \tuse\tyour\tperiodic\t table\tto\thelp\tyou. \t relative\tformula\tmass\t=\t..\t\t[2]  (ii)\t\tsodium\tcarbonate\t can\tbe\tmanufactured\t by\tthe\treaction\tbetween\t limestone\t and\t sodium\tchloride.\t the\treaction\tis\tendothermic. \t \twhat\tis\tmeant\tby\tthe\tterm\tendothermic ?  \t ...   [1]  (iii)\t\tduring\tthis\t glass-making\tprocess,\tlimestone\tdecomposes\tinto\tlime\t(calcium\toxide). \t \tlime\tis\tused\tto\ttreat\tacidic\tsoils. \t \twhat\ttype\tof\tchemical\treaction\toccurs\twhen\tlime\treacts\twith\tacidic\tsoils? \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. addition        neutralisation        oxidation        reduction  [1]",
            "15": "15 0620/31/o/n/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.  (b)\t\tcharcoal\t(carbon)\tcan\tbe\tburned\tin\tan\texcess\tof\tclean,\tdry\tair\tto\tprovide\tthe\theat\tneeded\tto\t make\tglass.  (i)\t\twhich\tgas\tis\t21%\tof\tclean,\tdry\tair?  \t ...   [1]  (ii)\t\twrite\ta\tword\tequation\tfor\tcarbon\tburning\tin\tan\texcess\tof\tair.  \t ...   [1]  (iii)\t\tcomplete\tthe\tenergy\tlevel\tdiagram\tfor\tthis\treaction\tby\tadding\tthese\t two\twords: \t \u25cf\t reactants \t \u25cf\t product energy progress of reaction  [1]  (c)\t\targon\tis\talso\tpresent\tin\tclean,\tdry\tair.  (i)\t\tgive\tone\tuse\tof\targon.  \t ...   [1]  (ii)  which two\tof\tthe\tfollowing\tstatements\tabout\targon\tare\tcorrect? \t \ttick\ttwo\tboxes. \t argon\tis\tunreactive. \t argon\tis\tdiatomic. \t argon\tis\tmonatomic. \t argon\tforms\tionic\tcompounds. \t argon\tis\ta\tgreenhouse\tgas.  [2] \t [total:\t10]",
            "16": "16 0620/31/o/n/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w18_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32 paper 3  theory (core) october/november 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib18 11_0620_32/3rp\u00a9 ucles 2018 *2139417189* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/o/n/18 \u00a9 ucles 2018 1 (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td\tand\te,\tare\tshown. a bcd e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\tstructures. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\tstate\twhich\tstructure,\ta,\tb,\tc,\td or e,\trepresents:  (i)\t\tan\tatom\tin\tgroup\tviii\tof\tthe\tperiodic\t table\t\t..   [1]  (ii)\t\tan\tatom\tof\ta\treactive\tnon-metal\t \t...   [1]  (iii)\t\tan\tatom\twith\ta\tproton\tnumber\tof\t11\t\t .   [1]  (iv)\t\tan\tatom\twith\tonly\tthree shells of electrons \t ..   [1]  (v)\t\tan\tatom\twhich\tforms\ta\tstable\tion\twith\ta \tsingle\tpositive\tcharge.\t \t..   [1]  (b)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\tthe\tnitrogen\tatom\t and\tchromium\tion\tshown. number\tof electronsnumber\tof neutronsnumber\tof protons 15n7 7 52cr 2+ 24 28  [3] \t [total:\t8]",
            "3": "3 0620/32/o/n/18 \u00a9 ucles 2018 [turn over 2 (a)\t\tthe\ttable\tshows\tthe\tconcentrations\tof\t the\tions\tpresent\tin\ta\tsolution\tobtained\tfrom\t cells\tin\tthe\t body. ion\tpresent formula\tof\tionconcentration in\tmg\t/\t1000\tcm3 sodium na+273 potassium k+540 calcium ca2+3 magnesium mg2+20 chloride cl \u2013140 hydrogencarbonate hco3\u2013730 phosphate po43\u20131 \t\tanswer\tthese\tquestions\tusing\tonly\tinformation\tfrom\tthe\ttable.  (i)\t\twhich\tnegative\tion\tis\tpresent\tin\tthe\thighest\tconcentration?  \t ...   [1]  (ii)\t\t\tcalculate\tthe\tmass\tof\tpotassium\tions\tpresent\tin\t250\t cm3\tof\tthis\tsolution. \t mass\tof\tpotassium\tions\t=\t..\tmg\t\t[1]  (iii)\t\tcalculate\tthe\ttotal\tmass\tof\tpositive\tions \tpresent\tin\t1000\t cm3\tof\tthis\tsolution. \t total\tmass\tof\tpositive\tions\t=\t..\tmg\t\t[1]  (iv)\t\tgive\tthe\tname\tof\tthe\tcompound\tformed \tfrom\tna+\tand\thco3\u2013\tions.  \t ...   [1]  (b)\t\tdescribe\twhat\tis\tobserved\tin\tthese\t two\treactions.  \u25cf\tan\texcess\tof\taqueous\tsodium\thydroxide\tis\tadded\tto\ta\tsolution\tcontaining\tca2+\tions.  \t  \u25cf\tan\texcess\tof\taqueous\tammonia\tis\tadded\tto\ta\tsolution\tcontaining\tca2+\tions.  \t  [2]",
            "4": "4 0620/32/o/n/18 \u00a9 ucles 2018  (c)\t\tlactic\tacid\tcan\tbuild\tup\tin\tmuscle\tcells\tduring\texercise. \t\tthe\tstructure\tof\tlactic\tacid\tis\tshown. ccooh oh h ch3  (i)\t\ton\tthe\tstructure,\tdraw\ta\tcircle\taround\tthe\tcarboxylic\tacid\tfunctional\tgroup.\t [1]  (ii)\t\tdeduce\tthe\tmolecular\t formula\tof\tlactic\tacid\tshowing\tthe\tnumber\tof\tcarbon,\thydrogen\t and\t oxygen\tatoms.  \t ...   [1]  (d)\t\tlactic\tacid\tcan\tform\ta\tpolymer. \t\tcomplete\tthe\tsentence\tabout\tpolymers\tusing\twords\tfrom\tthe\tlist. atomic        large        molecular        monomers        polymers        small \t\tduring\tpolymerisation\t ..\t molecules\t called\t..\t join\ttogether\tto    form\tlong-chain\tmolecules\twith\ta\tvery\thigh\trelative\t..\tmass.  [3] \t [total:\t11]",
            "5": "5 0620/32/o/n/18 \u00a9 ucles 2018 [turn over 3 (a)\t\tthe\ttable\tgives\tinformation\t about\tthe\tsolubility\tof\tcopper\tand\tselenium\tin\tan\torganic\tsolvent\t and\tin\twater.\t the\torganic\tsolvent\tboils\tat\t30\t \u00b0c. elementsolubility\tin organic\tsolventsolubility\tin water copper insoluble insoluble selenium soluble insoluble  (i)\t\tuse\tthe\tinformation\t in\tthe\ttable\tto\tsuggest\thow\tyou\tcould\tobtain\tpure,\tdry\tsamples\tof\t copper\tand\tselenium\tfrom\ta\tmixture\tof\tcopper\tpowder\tand\tselenium\tpowder.  \t .  \t .  \t .  \t .  \t .  \t ...   [4]  (ii)\t\tethanol\tis\tan\torganic\tsolvent. \t \tdraw\tthe\tstructure\tof\tethanol.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [2]  (iii)\t\tselenium\treacts\twith\tfluorine\tto\tform\tselenium( vi)\tfluoride. \t \tbalance\tthe\tchemical\tequation\tfor\tthis\treaction. se\t\t+\t\t.f2  \t\tsef6  [1]",
            "6": "6 0620/32/o/n/18 \u00a9 ucles 2018  (b)\t\tthe\tchemical\tequation\tfor\t the\treaction\tof\tcopper\twith\thot\tconcentrated\tsulfuric\t acid\tis\tshown. cu  +  2h2so4    cuso4  +  so2  +  2h2o  (i)\t\tcomplete\tthe\tword\tequation\tfor\tthis\treaction. copper +sulfuric acid... ...+..+...  [2] (ii)\t\tone\tof\tthe\tcompounds\tin\tthis\tequation\tis\ta\tpollutant\tgas\twhich\tcontributes\tto\tacid\train. \t \tidentify\tthe\tpollutant\tgas\tand\tstate\ta\tcommon\tsource\tof\tit. \t pollutant\tgas\t \t ...  source \t .  [2]  (c)\t\tsolid\thydrated\t copper( ii)\tsulfate\tdecomposes\t to\tanhydrous\t copper( ii)\tsulfate\twhen\tit\tis\t continuously\theated. \t\tis\tthis\tan\tendothermic\tor\tan\texothermic\treaction? \t\texplain\tyour\tanswer.  \t  \t..   [1] \t [total:\t12]",
            "7": "7 0620/32/o/n/18 \u00a9 ucles 2018 [turn over 4\t\tthis\tquestion\tis\tabout\tacids.  (a)\t\tthe\tstructure\tof\tfumaric\tacid\tis\tshown. ccooh c h hooch \t\tfumaric\tacid\tis\tan\tunsaturated\tcompound.  (i)\t\twhat\tfeature\tof\tthe\tstructure\tof\tfumaric\tacid\tshows\tthat\tit\tis\tunsaturated?  \t ...   [1]  (ii)\t\tdescribe\ta\t test\tfor\tan\tunsaturated\tcompound.  test \t ..  result \t ...  [2]  (b)\t\thydroiodic\tacid\tcan\tbe\tused\tfor\tthe\treduction\tof\tsome\tcarboxylic\tacids.  (i)\t\twhat\tis\tmeant\tby\tthe\tterm\treduction ?  \t ...   [1]  (ii)\t\thydroiodic\t acid\tis\toxidised\tby\toxygen. \t \tbalance\tthe\tchemical\tequation\tfor\tthis\treaction. .h i  +  o2    2h2o\t\t+\t\t. i2  [2]  (iii)\t\twhat\tpercentage\tof\tclean,\tdry\tair\tis\toxygen?  \t ...   [1]",
            "8": "8 0620/32/o/n/18 \u00a9 ucles 2018  (c)\t\tthe\tconcentration \tof\ta\tdilute\tacid\tcan\tbe\tfound\tby\treacting\tit\twith\taqueous\tsodium\thydroxide\t using\tthe\tapparatus\tshown. aqueous sodium hydroxide dilute acidconical flask  (i)\t\twhat\tpiece\tof\tapparatus\t should\tbe\tused\tto\tadd\texactly\t25.0\tcm3\tof\tdilute\tacid\tto\tthe\t conical\tflask?  \t ...   [1]  (ii)\t\ta\tfew\tdrops\tof\tlitmus\tsolution\tare\tadded \tto\tthe\tconical\tflask. \t \texplain\twhy\tlitmus\tsolution\tis\tadded\tto\tthe\tconical\tflask.  \t .  \t ...   [1]  (iii)\t\taqueous\tsodium\thydroxide\tis\tthen\tadded\tto\tthe\tdilute\tacid\tuntil\tit\tis\tin\texcess.\t \t \tdescribe\tthe\tchange\tin\tthe\tcolour\tof\tthe \tlitmus\tsolution\tin\tthe\tconical\tflask. \t \tfrom\t.\tto\t \t..  [2] \t [total:\t11]",
            "9": "9 0620/32/o/n/18 \u00a9 ucles 2018 [turn over 5\t\tbromine\tis\ta\tvolatile\tliquid.\tpotassium\tbromide\tis \ta\tcompound\tmade\tfrom\tbromine.  (a)\t\tuse\tthe\tkinetic\tparticle\tmodel\tto\tdescribe\tthe\tarrangement\t and\tmotion\tof\tthe\tparticles\tin\t bromine\twhen\tit\tis:  \u25cfa\tliquid  \t  \t  \u25cfa\tgas  \t  \t  [4]  (b)\t\tmolten\tpotassium\tbromide\tcan\tbe\telectrolysed\tusing\tthe\tapparatus\tshown. +\u2013power supply  (i)\t\ton\tthe\tdiagram,\tlabel: \t \u25cf\t the\tanode \t \u25cf\t\tthe\telectrolyte  [2]  (ii)\t\tpredict\tthe\tproducts\tof\tthis\telectrolysis\tat: \t the\tpositive\telectrode\t \t .. \t the\tnegative\telectrode.\t \t ...  [2]  (iii)\t\tgive\tone\tobservation\tthat\tis\tmade\tat\tthe\tpositive\telectrode.  \t ...   [1]  (iv)\t\tsuggest\twhy\tthe\telectrodes\tare\tmade\tof\tgraphite\tand\tnot\tof\tmagnesium.  \t .  \t ...   [1]",
            "10": "10 0620/32/o/n/18 \u00a9 ucles 2018  (c)\t\taqueous\tpotassium\tbromide\treacts\twith\taqueous\tchlorine.  (i)\t\tcomplete\tthe\tword\tequation\tfor\tthis\treaction. potassium bromide+ chlorine.. ..+..  [2]  (ii)\t\tusing\tideas\tabout\tthe\treactivity\tof\tthe\thalogens,\t explain\twhy\taqueous\tpotassium\t bromide\t does\tnot\treact\twith\taqueous\tiodine.  \t .  \t ...   [1]  (iii)\t\tdescribe\t what\tyou\twould\tobserve\twhen\taqueous\tsilver\tnitrate\tis\tadded\tto\taqueous\t potassium\tbromide.\t  \t ...   [2] \t [total:\t15]",
            "11": "11 0620/32/o/n/18 \u00a9 ucles 2018 [turn over 6 (a)\t\tthe\tdiagrams\tshow\tthe\tstructures\tof\tfour\tsubstances,\tr,\ts,\tt\tand\tu. r tus c c chh hh hhc chh hhc chh hhc chh hhc chh hhoco ocoo c oo c o ti ti ti ti ti titi ti ti ti tinh4+nh4+cl \u2013 nh4+nh4+cl \u2013nh4+cl \u2013cl \u2013 \t\tstate\twhich\tone\tof\tthese\tsubstances,\tr,\ts,\tt or u:  (i)\t\tis\tan\telement\t\t     [1]  (ii)\t\tcontains\tionic\tbonds  \t .   [1]  (iii)\t\tis\ta\tgas\tat\troom\ttemperature\t \t   [1]  (iv)\t\tis\ta\tpolymer.\t\t ... ..   [1]  (b)\t\tammonium\tchloride\tis\tpresent\tin\tsome\tfertilisers.   which two\tof\tthe\tfollowing\tcompounds\tare\talso\tpresent\tin\tmany\tfertilisers? \t\ttick\ttwo\tboxes. \t hydrogen\tsulfide \t calcium\tphosphate \t copper( ii)\tfluoride \t nickel( ii)\toxide \t potassium\tnitrate  [2]",
            "12": "12 0620/32/o/n/18 \u00a9 ucles 2018  (c)\t\ta\tmixture\tof\tammonium\tchloride\tand\taqueous\tsodium\thydroxide\tis\theated\tas\tshown. heatmixturefilter paper soaked in methyl orang e and acid \t\tthe\tfilter\tpaper\tchanges\tcolour\tfrom\tred\tto\tyellow. \t\texplain\twhy.  \t  \t..   [2] \t [total:\t8]",
            "13": "13 0620/32/o/n/18 \u00a9 ucles 2018 [turn over 7 (a)\t\tthe\tgraph\tshows\tthe\teffect\tof\ttemperature\t on\tthe\trate\tof\treaction\tof\tdilute\thydrochloric\t acid\t with\tzinc\tpowder. 25 20 15 10 5 0 01 02 03 04 0 temperature  / \u00b0crate of reaction in cm3 gas  / minute 50  (i)\t\tdetermine\t the\trate\tof\treaction\tat\t40\t \u00b0c. \t rate\tof\treaction\t=\t..\tcm3\tgas\t/\tminute\t\t[1]  (ii)\t\tthe\texperiments\twere\trepeated\tusing\tsmall\tlumps\tof\tzinc\tinstead\tof\tzinc\tpowder. \t \tall\tother\tconditions\twere\tkept\tthe\tsame.   on the grid,\t draw\ta\tgraph\tto\tshow\thow\tthe\trate\tof\treaction\tchanges\twith\ttemperature\t when\tsmall\tlumps\tof\tzinc\tare\tused\tinstead\tof\tzinc\tpowder.\t [2]  (b)\t\twhat\teffects\tdo\tthese\tfactors\thave\ton\tthe\trate\tof\ta\tchemical\treaction?  (i)\t decreasing \tthe\tconcentration\tof\ta\treactant  \t ...   [1]  (ii)\t adding\ta\tcatalyst  \t ...   [1]",
            "14": "14 0620/32/o/n/18 \u00a9 ucles 2018  (c)\t\tzinc\tand\tiron\tare\tboth\tmetals. \t\tgive\ttwo\tphysical\tproperties\twhich\tare\tcharacteristic\tof\tmetals.  1 \t.  2 \t.  [2]  (d)\t\tstainless\tsteel\tis\tan\talloy\tof\tiron.  (i)\t\twhat\tis\tmeant\tby\tthe\tterm\talloy ?  \t ...   [1]  (ii)\t\tgive\tone\tcommon\tuse\tof\tstainless\tsteel.  \t ...   [1] \t [total:\t9]",
            "15": "15 0620/32/o/n/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. 8\t\tthe\ttable\tshows\tthe\tproperties\tof\tsome\tgroup\ti\t elements. elementdensity in\tg\t/\tcm3melting\tpoint in \u00b0crelative hardness sodium 0.97 98 4.9 potassium 0.86 63 2.6 rubidium 1.53 1.6 caesium 29 1.0  (a) (i)\t\tdescribe\tthe\ttrend\tin\tthe\trelative\thardness\tof\tthe\tgroup\ti\telements.  \t ...   [1]  (ii)\t\tpredict\tthe\tmelting\tpoint\tof\trubidium.  \t ...   [1]  (iii)\t\texplain\twhy\tit\tis\tdifficult\tto\tpredict\tthe\tdensity\tof\tcaesium.  \t .  \t ...   [1]  (b)\t\twhen\tpotassium\treacts\twith\twater,\tit\tfloats\tand\tmelts\tinto\ta\tball.\t a\tflame\tis\tobserved.  (i)\t\twhat\tcolour\tdoes\tpotassium\tgive\tto\tthe \tflame?  \t ...   [1]  (ii)\t\tuse\tthe\tinformation\tin\tthe\ttable\tto\tsuggest\twhy\tpotassium\tfloats\ton\twater.  \t ...   [1]  (iii)\t\thydrogen\tis\tproduced\twhen\tpotassium\t reacts\twith\twater. \t \tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\ta\tmolecule\tof\t hydrogen.  h h  [1] \t [total:\t6]",
            "16": "16 0620/32/o/n/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w18_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 20.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33 paper 3  theory (core) october/november 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 18 printed pages and 2 blank pages. [turn overib18 11_0620_33/3rp\u00a9 ucles 2018 *5703974316* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/33/o/n/18 \u00a9 ucles 2018 1 (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td\tand\te,\tare\tshown. a bcd e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\tstructures. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\tstate\twhich\tstructure,\ta,\tb,\tc,\td or e,\trepresents:  (i)\t\tan\tatom\twith\ta\ttotal\tof\teight\telectrons\t\t ..   [1]  (ii)\t\tan\tatom\tin\tgroup\tv\tof\tthe\tperiodic\t table\t\t.   [1]  (iii)\t\tan\tatom\twith\ta\tcomplete\touter\tshell\tof\telectrons\t\t .   [1]  (iv)\t\tan\tatom\tof\ta\tmetallic\telement\t \t ...  [1]  (v)\t\tan\tatom\twhich\tforms\ta\tstable\tion\twith\ta \tsingle\tpositive\tcharge.\t \t..   [1]  (b)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\tthe\tneon\tatom\t and\tcopper\tion\tshown. number\tof electronsnumber\tof neutronsnumber\tof protons 22ne10 10 65cu+ 29 36  [3] \t [total:\t8]",
            "3": "3 0620/33/o/n/18 \u00a9 ucles 2018 [turn over 2 (a)\t\tthe\ttable\tshows\tthe\tconcentrations\t of\tthe\tions\tpresent\tin\tthe\tsolution\tobtained\tfrom\tsquid\t nerve\tcells\tand\tin\thuman\tblood\tplasma. ion\tpresentsolution\tobtained\tfrom squid\tnerve\tcellshuman\tblood\t plasma concentration in\tg\t/\t1000\tcm3concentration in\tg\t/\t1000\tcm3 sodium 1.15 3.25 potassium 15.60 0.16 magnesium 0.03 0.04 chloride 3.55 3.65 hydrogencarbonate trace 1.50 \t\tanswer\tthese\tquestions\tusing\tonly\tinformation\tfrom\tthe\ttable.  (i)\t\tgive\t two\tmajor\tdifferences\t between\tthe\tconcentrations\t of\tthe\tions\tpresent\tin\tthe\tsolution\t obtained\tfrom\tsquid\tnerve\tcells\tand\tin\thuman\tblood\tplasma.  1 \t .. \t 2\t\t .. \t [2]  (ii)\t\t\tcalculate\t the\tmass\tof\tpotassium\t ions\tpresent\tin\t250\tcm3\tof\tthe\tsolution\tobtained\tfrom\t squid\tnerve\tcells. \t mass\tof\tpotassium\tions\t=\t..\tg\t\t[1]  (b)\t\tdescribe\ta\ttest\tfor\tsodium\tions.  test \t.  result \t.. \t [2]",
            "4": "4 0620/33/o/n/18 \u00a9 ucles 2018  (c)\t\tsquid\tproduce\tan\tink\twhich\tcontains\ta\tcompound\tcalled\ttaurine. \t\tthe\tstructure\tof\ttaurine\tis\tshown. so och hcnh hh hoh \t\tdeduce\tthe\tmolecular\t formula\tof\ttaurine\tshowing\tthe\tnumber\tof\tcarbon,\thydrogen,\t oxygen,\t nitrogen\tand\tsulfur\tatoms.  \t..   [1]  (d)\t\tthe\tink\tused\tfor\twriting\tis\ta\tmixture\tof\tdyes. \t\tthese\tdyes\tcan\tbe\tseparated\tby\tpaper\tchromatography. \t\tdescribe\thow\tto\tseparate\ta\tmixture\tof\tdyes\tusing\tpaper\tchromatography. \t\tinclude\ta\tlabelled\tdiagram\tin\tyour\tanswer.  \t  \t  \t  \t  \t \t [4] \t [total:\t10]",
            "5": "5 0620/33/o/n/18 \u00a9 ucles 2018 [turn over 3 (a)\t\tbrass\tis\tan\talloy\tof\tcopper\tand\tzinc.  (i)  which one\tof\tthe\tfollowing\tdiagrams\tbest\trepresents\tan\talloy? j kl m  \t ...   [1]  (ii)\t\tbrass\tis\tused\tto\tmake\tthe\tpropellers\tof\t ships\trather\tthan\tpure\tcopper\tor\tpure\tzinc. \t \tsuggest\ta\tproperty\tof\tbrass\twhich\texplains\tthis.  \t .  \t ...   [1]  (b)\t\tthe\tchemical\tequation\tfor\tthe\treaction\tof\tzinc\twith\tconcentrated\tnitric\tacid\tis\tshown. zn\t\t+\t\t4hno3  \t\tzn(no3)2\t\t+\t\t2no2\t\t+\t\t2h2o  (i)\t\tcomplete\tthe\tword\tequation\tfor\tthis\treaction. zinc +nitric acid... ...+..+... \t [2]  (ii)\t one\tof\tthe\tcompounds\tin\tthis\tequation\tis\ta\tpollutant\tgas\twhich\tcontributes\tto\tacid\train. \t \tidentify\tthe\tpollutant\tgas\tand\tstate\ta\tcommon\tsource\tof\tit. \t pollutant\tgas\t \t ...  source \t . \t [2]  (c)\t\tzinc\toxide\tis\treduced\tby\theating\tit\twith\tcarbon. zno\t\t+\t\tc\t\t \t\tzn\t\t+\t\tco \t\thow\tdoes\tthis\tequation\tshow\tthat\tzinc\toxide\tis\treduced?  \t  \t..   [1]",
            "6": "6 0620/33/o/n/18 \u00a9 ucles 2018  (d)\t\twhen\tgreen\tiron( ii)\tsulfate\tis\theated\tit\tloses\tits\twater\tof\tcrystallisation. \t\tthe\treaction\tis\treversible.  (i)\t\tcomplete\tthe\tfollowing\tequation\tby\twriting\tthe\tsign\tfor\ta\treversible\treaction\tin\tthe\tbox. feso4.7h2o\t\t\t\t \t\t\t\tfeso4\t\t+\t\t7h2o \t green\t white  [1]  (ii)\t\tuse\tthe\tinformation\t in\tthe\tequation\tto\tsuggest\thow\tto\tchange\twhite\tiron(ii)\tsulfate\tinto\t green\tiron( ii)\tsulfate.  \t ...   [1] \t [total:\t9]",
            "7": "7 0620/33/o/n/18 \u00a9 ucles 2018 [turn over 4 (a)\t\tthe\tstructure\tof\tcompound\tp\tis\tshown. c c hh hh c coohh hc hcompound p  (i)\t\twhat\tfeature\tof\tthe\tstructure\tof\tcompound\tp\tshows\tthat\tit\tis\tunsaturated?  \t ...   [1]  (ii)\t\tdescribe\tthe\tcolour\tchange\twhen\tan\texcess\tof\tcompound\t p\tis\tadded\tto\taqueous\tbromine. \t from\t.\tto\t \t.. \t [2]  (iii)\t\tcompound \tp\thas\ta\t\u2013cooh\tfunctional\tgroup. \t \tdraw\tthe\tstructure\tof\tthe\t\u2013cooh\tfunctional\t group.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\t bonds.  [1]  (iv)\t\twhat\teffect\twould\tcompound\t p\thave\ton\tlitmus\tsolution?  \t ...   [1]",
            "8": "8 0620/33/o/n/18 \u00a9 ucles 2018  (b)\t\tthe\tconcentration\t of\taqueous\tsodium\thydroxide\t can\tbe\tfound\tby\treacting\tit\twith\tan\tacid\tof\t known\tconcentration. \t\tthe\tgraph\tshows\thow\tthe\tph\tof\taqueous\tsodium\thydroxide\t in\ta\tconical\tflask\tchanges\tas\tacid\t is\tadded\tto\tit. 05 10 15 volume of acid added  / cm320 25 3014 12 10 8 64 2 0ph  (i)\t\tdescribe\thow\tthe\tph\tchanges\tas\tthe\tacid\tis\tadded.  \t .  \t .  \t ... \t\t[2]  (ii)\t\twhat\tis\tthe\tph\tof\tthe\taqueous\tsodium\thydroxide\tbefore\tthe\tacid\tis\tadded?  \t ...   [1]  (iii)\t\twhat\tvolume\tof\tacid\thas\tbeen\tadded\twhen\tthe\tsolution\treaches\tneutral\tph?  \t ...   [1] \t [total:\t9]",
            "9": "9 0620/33/o/n/18 \u00a9 ucles 2018 [turn over 5 (a)\t\twhen\tsulfur\tvapour\tfalls\ton\tto\ta\tcold\tsurface,\tsmall \tcrystals\tof\tsolid\tsulfur\tform. \t\tuse\tthe\tkinetic\tparticle\tmodel\tto\tdescribe\tthe\tarrangement\t and\tmotion\tof\tthe\tparticles\tin\tsulfur\t when\tit\tis:  \u25cfa\tgas  \t  \t  \u25cfa\tsolid  \t  \t \t [4]  (b)\t\tsulfur\tdioxide\tis\tformed\twhen\tcopper\treacts\twith\thot\tconcentrated\tsulfuric\tacid. \t\tbalance\tthe\tchemical\tequation\tfor\tthis\treaction. cu\t\t+\t\t.h2so4  \t\tcuso4\t\t+\t\tso2\t\t+\t\t.h2o \t [2]  (c)\t\thot\tcopper\treacts\twith\tchlorine\tto\tform\tcopper( ii)\tchloride. \t\tdescribe\ta\ttest\tfor\tchloride\tions.  test \t.  result \t.. \t [2]",
            "10": "10 0620/33/o/n/18 \u00a9 ucles 2018  (d)\t\tmolten\tcopper( ii)\tchloride\tcan\tbe\telectrolysed\tusing\tthe\tapparatus\tshown. +\u2013power supply  (i)\t\ton\tthe\tdiagram\tlabel: \t \u25cf\t the\tcathode \t \u25cf\t the\telectrolyte \t [2]  (ii)\t\tpredict\tthe\tproducts\tof\tthis\telectrolysis\tat: \t the\tpositive\telectrode\t \t .. \t the\tnegative\telectrode.\t \t ... \t [2]  (iii)\t\tgive\tone\tobservation\tthat\tis\tmade\tat\tthe\tpositive\telectrode.  \t ...   [1] \t [total:\t13]",
            "11": "11 0620/33/o/n/18 \u00a9 ucles 2018 [turn over 6 (a)\t\tthe\tdiagrams\tshow\tthe\tstructures\tof\tfour\tsubstances,\tr,\ts,\tt\tand\tu. rs tu k+i\u2013k+i\u2013 i\u2013k+k+i\u2013 k+i\u2013k+i\u2013 i\u2013k+k+i\u2013mnmnmnmn mnmnmnmn mnmnmnmnn n n n n nn n n nc cc c c c c c c cc cc ccccc cc c c cc cccc c c \t\tstate\twhich\tone\tof\tthese\tsubstances,\tr,\ts,\tt or u:  (i)\t\tis\ta\tcompound  \t ...   [1]  (ii)\t\tconducts\telectricity\twhen\tsolid  \t ...   [1]  (iii)\t\thas\tthe\tlowest\tmelting\tpoint  \t ...   [1]  (iv)\t\tis\ta\tmacromolecule  \t ...   [1]  (v)\t\tcan\tact\tas\ta\tcatalyst.  \t ...   [1]  (b)\t\tsubstance\ts\tis\tpotassium\tiodide. \t\twhen\taqueous\tpotassium\tiodide\treacts\twith\taqueous\tchlorine,\tthe\tsolution\tturns\tbrown. \t\tname\tthe\tbrown\tsubstance\t that\tforms.\tusing\tideas\tabout\tthe\treactivity\t of\tthe\thalogens,\t suggest\twhy\tthe\tbrown\tsubstance\tforms.  \t  \t.. \t\t[2]",
            "12": "12 0620/33/o/n/18 \u00a9 ucles 2018  (c)\t\tpotassium\tsalts\tare\tpresent\tin\tmany\tfertilisers.   which one\tof\tthe\tfollowing\tcompounds\tis\talso\tpresent\tin\tmany\tfertilisers? \t\ttick\tone\tbox. \t lead( ii)\tbromide \t calcium\tphosphate \t copper( ii)\tsulfide  tin( iv)\toxide  [1]  (d)\t\tmany\tfertilisers\tcontain\tammonium\tsalts. \t\texplain\twhy\tfarmers\tdo\tnot\tadd\tcalcium\thydroxide\t (slaked\tlime)\tto\tthe\tsoil\tat\tthe\tsame\ttime\t as\tfertilisers\tcontaining\tammonium\tsalts.  \t  \t  \t.. \t\t[2] \t [total:\t10]",
            "13": "13 0620/33/o/n/18 \u00a9 ucles 2018 [turn over 7\t\ta\tstudent\tinvestigates\tthe\trate\tof\treaction\tof\tiron \tpowder\twith\tdilute\thydrochloric\tacid. dilute hydrochloric acid iron powde r  (a)\t\tcomplete\t the\tdiagram\tto\tshow\tthe\tapparatus \tthe\tstudent\tcould\tuse\tto\tcollect\tand\tmeasure\tthe\t gas\tproduced. \t\tlabel\tyour\tdiagram.\t [3]",
            "14": "14 0620/33/o/n/18 \u00a9 ucles 2018  (b)\t\tthe\tgraph\tshows\tthe\tresults\tthe\tstudent\tobtained\tusing\tdilute\thydrochloric\t acid\tof\tconcentration\t 0.2\tmol\t/\tdm3\tand\tan\texcess \tof\tiron\tpowder. 120 100 80 60 40 20 0 0123 4 time  / minutevolume of gas  / cm3 567 \t\tuse\tthe\tgraph\tto\tdeduce:  (i)\t\tthe\ttime\tthat\tthe\treaction\twas\tcomplete  \t ...   [1]  (ii)\t\tthe\tvolume \tof\tgas\tproduced\twhen\tthe\treaction\twas\tcomplete.  \t ...   [1]  (c)\t\tthe\tstudent\trepeated\tthe\texperiment\tusing\ta\tlower \tconcentration\tof\tdilute\thydrochloric\tacid. \t\tall\tother\tconditions\twere\tkept\tthe\tsame.   on the grid,\t draw\ta\tgraph\tto\tshow\thow\tthe\tvolume\tof\tgas\tchanges\twith\ttime\twhen\ta\tlower\t concentration\tof\tdilute\thydrochloric\tacid\tis\tused.\t [2]",
            "15": "15 0620/33/o/n/18 \u00a9 ucles 2018 [turn over  (d)\t\tiron\tis\textracted\tfrom\tiron\tore\tusing\ta\tblast\tfurnace. \t\tthe\tsolid\tsubstances\t added\tto\tthe\tblast\tfurnace\tare\tiron\tore,\tcoke\tand\tlimestone\t (calcium\tcarbonate).  (i)\t\tstate\tthe\tname\tof\tan\tore\tof\tiron.  \t ...   [1]  (ii)\t\tcomplete\t the\tsentences \tabout\tthe\treactions\t which\toccur\tin\ta\tblast\tfurnace\tusing\twords\t from\tthe\tlist.  air decomposes dioxide monoxide  nitrogen oxidises slag tetrachloride \t \tthe\tcoke\tburns\tin\ta\tblast\tof\thot\t..\t to\tform\tcarbon\tdioxide.\tthis\treacts\twith    further\thot\tcoke\tto\tform\tcarbon\t..\t .\tthis\tgas\treduces\tthe\tiron(iii)\toxide\tin   the\tiron\tore\tto\tiron. \t \tthe\tlimestone\t ..\t to\tform\tlime\t(calcium\toxide)\twhich\treacts\twith\timpurities\t     in\tthe\tiron\tto\tform\t..\t. \t [4] \t [total:\t12]",
            "16": "16 0620/33/o/n/18 \u00a9 ucles 2018 8\t\tthe\ttable\tshows\tthe\tproperties\tof\tsome\tgroup\tvii\telements. elementboiling\tpoint in \u00b0cdensity\tat room\ttemperature in\tg\t/\tcm3physical\tstate\tat room\ttemperature fluorine \u2013188 0.0017 chlorine 0.0032 gas bromine 59 3.1 liquid iodine 184 4.9 solid  (a) (i)\t\tuse\tthis\tinformation\tto: \t \u25cf\t\tidentify\tthe\tphysical\tstate\tof\tfluorine\tat\troom\ttemperature  \t . \t \u25cf\t\testimate\tthe\tboiling\tpoint\tof\tchlorine.  \t . \t [2]  (ii)\t\tsuggest\twhy\tthe\tdensity\tof\tchlorine\tis\tmuch\tlower\tthan\tthe\tdensities\tof\tbromine\tand\t iodine.  \t .  \t ...   [1]  (b)\t\tchlorine\tis\tused\tin\twater\ttreatment.  (i)\t\twhy\tis\tchlorine\tadded\tto\twater?  \t ...   [1]  (ii)\t\tstate\tone\tmajor\tuse\tof\twater\tin\tindustry.  \t ...   [1]  (c)\t\tchlorine\treacts\twith\tphosphorus\tto\tform\tphosphorus( iii)\tchloride. \t\tbalance\tthe\tchemical\tequation\tfor\tthis\treaction. .p\t\t+\t\t.c l 2  \t\t2pcl 3 \t [2]",
            "17": "17 0620/33/o/n/18 \u00a9 ucles 2018 [turn over  (d)\t\tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\ta\tmolecule\t of\t chlorine.\tshow\touter\tshell\telectrons\tonly. cl cl \t [2] \t [total:\t9]",
            "18": "18 0620/33/o/n/18 \u00a9 ucles 2018blank page",
            "19": "19 0620/33/o/n/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.",
            "20": "20 0620/33/o/n/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w18_qp_41.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/41   paper 4  theory (extended) october/november 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib18 11_0620_41/3rp\u00a9 ucles 2018 *4984158881* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/41/o/n/18 \u00a9 ucles 2018 1  the following formulae represent different substances. al        ag        caco3        ch4        c l 2        cu        so2   answer the following questions using only these substances.   each substance may be used once, more than once or not at all.   state which substance is:  (a)  used to make food containers  .   [1]  (b)  added to a blast furnace to remove impurities during the production of iron  ...   [1]  (c)  the main constituent of natural gas  ..   [1]  (d)  a cause of acid rain  .   [1]  (e)  a gas which bleaches damp litmus paper     [1]  (f)  a gas which contributes to climate change.  .   [1] [total: 6]",
            "3": "3 0620/41/o/n/18 \u00a9 ucles 2018 [turn over 2  the table gives some information about four different particles, a, b, c and d. particlenumber of electronsnumber of neutronsnumber of protonselectronic structurecharge on particle a 11 12 11 2,8,1 0 b 14 11 2,8,1 0 c 18 20 2,8,8 0 d 18 20 17  (a)\t\tcomplete\tthe\ttable.\t the\tfirst\trow\thas\tbeen\tdone\tfor \tyou.\t [4]  (b)  give two particles from the table which are isotopes of each other.   ..   [1]  (c)  element z is in the same group of the periodic table as a and is less reactive than a.   state the identity of element z.   ..   [1]  (d)  c is unreactive.   use information from the table to explain why.   ..   [1]  [total: 7]",
            "4": "4 0620/41/o/n/18 \u00a9 ucles 2018 3 (a)  copper( ii) nitrate decomposes when heated. two gases, oxygen and nitrogen dioxide, and a  solid are made in the reaction.   a sample of copper( ii) nitrate was decomposed using the apparatus shown. x aqueous sodium hydroxidecopper( ii) nitrate heatwate r  (i)  complete the chemical equation for the reaction.  2cu(no3)2    o2  +  ..no2  +  .. [2]  (ii)  only oxygen gas is collected at x.   explain why.   .   ...   [1]  (b)  nitrogen dioxide and other oxides of nitrogen are formed in car engines.   explain how nitrogen dioxide is formed in car engines.            ..   [2]",
            "5": "5 0620/41/o/n/18 \u00a9 ucles 2018 [turn over  (c)  a teacher heated 18.8 g of copper( ii) nitrate.  (i)  calculate the number of moles of copper( ii) nitrate present in the 18.8 g. .. mol  [2]  (ii)  calculate the maximum number of moles of oxygen that can be made by heating 18.8 g of  copper( ii) nitrate. .. mol  [1]  (iii)  calculate the maximum volume of oxygen at room temperature and pressure, in cm3, that  can be made by heating 18.8 g of copper( ii) nitrate. .. cm3  [1]  (d)  a sample of copper( ii) nitrate was dissolved in water to form an aqueous solution.   the aqueous solution was split into three portions. a separate test was done on each portion  as shown. test reagent added result 1aqueous sodium hydroxidelight blue precipitate forms 2 zinc powdersolution changes from blue to colourless and a brown solid forms 3 ammonia gas is produced  (i)  give the formula of the light blue precipitate formed in test 1.   ...   [1]  (ii)  explain the changes seen in test 2.   .   .   .   ...   [3]  (iii)  identify the two reagents that must be added to the aqueous copper( ii) nitrate in test 3.  1  ..  2  ..  [2]",
            "6": "6 0620/41/o/n/18 \u00a9 ucles 2018  (e)  copper( ii) nitrate can be made by reacting copper( ii) carbonate with nitric acid. one of the  products is carbon dioxide.  (i)  write a chemical equation for the reaction of copper( ii) carbonate with nitric acid.   ...   [2]  (ii)  carbon dioxide is added to the air by living things.   name the chemical process by which living things add carbon dioxide to the air.   ...   [1]  (iii)  carbon dioxide is removed from the air by plants.   name the chemical process by which plants remove carbon dioxide from the air.   ...   [1]  [total: 19]",
            "7": "7 0620/41/o/n/18 \u00a9 ucles 2018 [turn over 4 (a)  sulfuric acid is made industrially by a four-step process.  step 1  sulfur is burned in air to produce sulfur dioxide.  step 2  sulfur dioxide is converted into sulfur trioxide.  step 3  sulfur trioxide is reacted with concentrated sulfuric acid to produce oleum.  step 4  oleum is reacted with water to produce concentrated sulfuric acid.  (i)  some sulfur is obtained by mining.   name one other major source of sulfur.   ...   [1]  (ii)  what is the name of the process by which sulfuric acid is made industrially?   ...   [1]  (iii)  describe the conversion of sulfur dioxide into sulfur trioxide in step 2.   in your answer, include: \t \u25cf\t\ta\tchemical\tequation\tfor\tthe\treaction \t \u25cf\t\tthe\tessential\treaction\tconditions.   .   .   .   .   .   .   ...   [5]  (b)  when concentrated sulfuric acid is added to glucose, c6h12o6, a black solid is produced. the  concentrated sulfuric acid acts as a dehydrating agent.  (i)  what is removed from the glucose in this reaction?   ...   [1]  (ii)  name the black solid produced in this reaction.   ...   [1]",
            "8": "8 0620/41/o/n/18 \u00a9 ucles 2018  (c)\t\tthe\tgas\thydrogen\t sulfide,\th2s, is produced when concentrated sulfuric acid is added to solid  potassium iodide.   the reaction involves oxidation.  (i)\t\tdefine\tthe\tterm\toxidation  in terms of electron transfer.   ...   [1]  (ii)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  hydrogen\tsulfide.\tshow\touter\tshell\telectrons\tonly. h h s [2]  (iii)\t\thydrogen\tsulfide\thas\ta\tsimple\tmolecular\tstructure. \t \texplain\twhy\thydrogen\tsulfide\thas\ta\tlow\t boiling\tpoint.   .   .   ...   [2]",
            "9": "9 0620/41/o/n/18 \u00a9 ucles 2018 [turn over  (d)  dilute sulfuric acid reacts with aqueous sodium hydrogencarbonate in a neutralisation reaction. h2so4(aq)  +  2nahco3(aq)    na2so4(aq)  +  2h2o(l)  +  2co2(g)   in a titration, 0.200 mol / dm3 aqueous sodium hydrogencarbonate was used to neutralise  20.0 cm3 of dilute sulfuric acid of concentration 0.150 mol / dm3.  (i)  calculate the number of moles of dilute sulfuric acid used in the titration. .. mol  [1]  (ii)  calculate the number of moles of sodium  hydrogencarbonate needed to neutralise the  dilute sulfuric acid. .. mol  [1]  (iii)  calculate the volume, in cm3, of 0.200 mol / dm3 aqueous sodium hydrogencarbonate  needed to neutralise the dilute sulfuric acid. .. cm3  [1] [total: 17]",
            "10": "10 0620/41/o/n/18 \u00a9 ucles 2018 5  hydrogen gas reacts with iodine gas. the equation is shown. h2(g)  +  i2(g)    2hi(g)   the reaction is reversible and can reach equilibrium.  (a)  what is meant by the term equilibrium ?         ..   [2]  (b)  the graphs show how pressure affects the yield of hydrogen iodide, hi, at two different  temperatures. yield of hydrogen iodide pressure500  \u00b0c 700  \u00b0c  (i)  explain why the yield at 500 \u00b0c does not change as the pressure is increased.   .   ...   [1]  (ii)  what can you conclude from the difference in the yield of hydrogen iodide at the two  temperatures shown? explain your answer.   .   .   ...   [2]",
            "11": "11 0620/41/o/n/18 \u00a9 ucles 2018 [turn over  (c)  the graph shows how the concentration of hydrogen iodide, hi, changes after hydrogen gas  and iodine gas are mixed together in a sealed container. concentration of hydrogen iodide time  (i)  when is the rate of reaction fastest?   ...   [1]  (ii)  the reaction was repeated at the same temperature and pressure but in the presence of  a catalyst.   draw a graph on the same axes to show how the concentration of hydrogen iodide changes  with time in the presence of a catalyst. [2]  (d)  a mixture of hydrogen gas and iodine gas is allowed to reach equilibrium.  (i)  increasing the pressure of a gas increases its concentration.   state and explain the effect of increasing the pressure on the rate of the forward reaction.   .   .   ...   [2]  (ii)  state and explain the effect of increasing the temperature on the rate of the reverse  reaction.   .   .   .   .   ...   [3] [total: 13]",
            "12": "12 0620/41/o/n/18 \u00a9 ucles 2018 6 (a)  ethane, c2h6, is a member of the homologous series called alkanes.   ethanol, c2h5oh, is a member of the homologous series called alcohols.  (i)  alkanes are hydrocarbons.   what is meant by the term hydrocarbon ?   .   ...   [2]  (ii)  all members of a homologous series can be represented by a general formula.   state the general formula of: \t \u25cf\t\talkanes\t   \t \u25cf\t\talcohols\t  [2]  (iii)  state two characteristics, other than having the same general formula, of members of a  homologous series.  1  ..   .  2  ..   . [2]  (b)  ethane can react with chlorine in a substitution reaction.  (i)  state one essential reaction condition.   ...   [1]  (ii)  draw the structure of the organic product formed by substitution of one of the hydrogen  atoms in ethane with chlorine. show all of the atoms and all of the bonds.  [1]  (iii)  name the product of the substitution reaction between ethane and chlorine that does not  contain carbon.   ...   [1]",
            "13": "13 0620/41/o/n/18 \u00a9 ucles 2018 [turn over  (c)  propan-1-ol is an alcohol.   the structure of propan-1-ol is shown. ch h hch hch hoh   propan-1-ol reacts with ethanoic acid to form an ester.   give the name of the ester formed in this reaction.   ..   [1]  (d)  ester y has the structure shown. ch h hchhh hcc h ester yh o co h  (i)  give the molecular formula of ester y.   ...   [1]  (ii)  draw the structures of the carboxylic acid and the alcohol used to make ester y. show all  of the atoms and all of the bonds. give the name of the carboxylic acid and the alcohol.  structure of the carboxylic acid  name of the carboxylic acid     structure of the alcohol  name of the alcohol   [4]",
            "14": "14 0620/41/o/n/18 \u00a9 ucles 2018  (e)  nylon is a polyamide.   complete the diagram to show the structure of nylon. show all of the atoms and all of the  bonds present in the linkages. [3] [total: 18]",
            "15": "15 0620/41/o/n/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "16": "16 0620/41/o/n/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w18_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/42 paper 4  theory (extended) october/november 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib18 11_0620_42/3rp\u00a9 ucles 2018 *4401701629* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/o/n/18 \u00a9 ucles 2018 1  element x can undergo the following physical changes. gaseous xboiling or evaporation liquid x solid x2 4 3 1  (a) (i)\t\tgive\tthe\tscientific\tname\tfor\teach\tof\tthe\t numbered\tphysical\tchanges.  1  ..  2  ..  3  ..  4  ..  [4]  (ii)  explain why the changes shown are physical changes.   .   ...   [1]  (iii)\t\tone\tdifference\tbetween\tboiling\tand\tevaporation\tis\tthe\trate\tat\twhich\tthe\tprocesses\toccur.   state one\tother\tdifference\tbetween\tboiling\tand\tevaporation.   .   ...   [1]  (b)\t\tdescribe\tthe\tseparation,\tarrangement\tand\tmotion\tof\tparticles\tof\telement\tx in the solid state.  separation  ..  arrangement  ..  motion    [3]  (c)  element x\tis\ta\tgroup\ti\tmetal.\tit\tburns\tin\tair\tto\tform\tan\toxide\tx2o.  write a chemical equation for this reaction.   ..   [2]  [total: 11]",
            "3": "3 0620/42/o/n/18 \u00a9 ucles 2018 [turn over 2\t\tmagnesium,\tcalcium\tand\tstrontium\tare\tgroup\tii\t elements.  (a)\t\tcomplete\tthe\ttable\tto\tshow\tthe\tarrangement\tof\telectrons\tin\ta\tcalcium\tatom. shell\tnumber 1 2 3 4 number\tof\telectrons  [1]  (b)\t\tdescribe\thow\tthe\tarrangement\tof\telectrons\tin\ta\tstrontium\tatom\tis:  (i)  similar to the arrangement of electrons in a calcium atom   .   .  (ii)  different from the arrangement of electrons in a calcium atom.   .   .  [2]  (c)  calcium reacts with cold water to form two products:  \u25cf\ta\tcolourless\tgas,\t p,\twhich\t\u2018pops\u2019 \twith\ta\tlighted\tsplint  \u25cf\ta\tweakly\talkaline\tsolution,\t q,\twhich\tturns\tmilky\twhen\tcarbon\tdioxide\tis\tbubbled\tthrough\tit.  (i)  name gas p.   ...   [1]  (ii)\t\tidentify\tthe\tion\tresponsible\tfor\tmaking\tsolution\t q alkaline.   ...   [1]  (iii)  suggest the ph of solution q.   ...   [1]  (iv)  write a chemical equation for the reaction of calcium with cold water.   ...   [2]",
            "4": "4 0620/42/o/n/18 \u00a9 ucles 2018  (d)\t\tmagnesium\t reacts\twith\tchlorine\tto\tform\tmagnesium \tchloride,\tmgcl 2. magnesium chloride is  an ionic compound.  (i)  complete the diagrams to show the electronic structures of the ions in magnesium chloride.  show the charges on the ions. cl.. mg.. cl..  [3]  (ii)  give three physical properties that are typical of ionic compounds such as mgcl 2.  1  ..  2  ..  3  ..  [3]  (e)  aqueous magnesium chloride is added to aqueous silver nitrate. a white precipitate forms.   write an ionic\tequation\tfor\tthis\treaction.\tinclude\tstate\tsymbols.   ..   [2]  [total: 16]",
            "5": "5 0620/42/o/n/18 \u00a9 ucles 2018 [turn over 3  sulfur is an important element.  (a)\t\texplain\thow\tburning\tfossil\tfuels\tcontaining\tsulfur\tleads\tto\tthe\tformation\tof\tacid\train.         ..   [2]  (b)\t\tsulfuric\tacid\tis\tmanufactured\t by\tthe\tcontact\tprocess.\tone\tstep\tin\tthe\tcontact\tprocess\tinvolves\t a\treversible\treaction\tin\twhich\tsulfur\ttrioxide,\tso3,\tis\tformed.  (i)\t\twrite\ta\tchemical\tequation\tfor\tthis\treversible\t reaction.\tinclude\tthe\tcorrect\tsymbol\tto\tshow\t that\tthe\treaction\tis\treversible.   ...   [2]  (ii)\t\tstate\tthe\tconditions\tand\tname\tthe\tcatalyst\tused\tin\tthis\treversible\treaction.  temperature    pressure  ..  catalyst  ...  [3]  (iii)\t\tdescribe\thow\tthe\tsulfur\ttrioxide\tformed\tis\tconverted\t into\tsulfuric\tacid\tin\tthe\tnext\tsteps\tof\t the contact process.   .   .   ...   [2]",
            "6": "6 0620/42/o/n/18 \u00a9 ucles 2018  (c)  dilute sulfuric acid is used to make salts known as sulfates. \t\ta\tmethod\tconsisting\tof\tthree\tsteps\tis\tused\tto\tmake\tzinc\tsulfate\tfrom\tzinc\tcarbonate.  step 1\t\tadd\tan\texcess\tof\tzinc\tcarbonate\t to\t20\tcm3\tof\t0.4\tmol\t/\tdm3 dilute sulfuric acid until  the reaction is complete.  step 2  filter the mixture.  step 3\t\theat\tthe\tfiltrate\tuntil\ta\tsaturated\tsolution\tforms\tand \tthen\tallow\tit\tto\tcrystallise.  (i)\t\tname\ta\tsuitable\tpiece\tof\tapparatus\tfor\tmeasuring\t20\t cm3 of dilute sulfuric acid in step 1.   ...   [1]  (ii)  state two\tobservations\twhich\twould\tshow\tthat\tthe\treaction\tis\tcomplete\tin\t step 1.  1  ..  2  ..  [2]  (iii)\t\twhy\tis\tit\timportant\tto\tadd\tan\texcess\tof\tzinc\tcarbonate\tin\t step 1?   ...   [1]  (iv)\t\twhat\tis\tmeant\tby\tthe\tterm\tsaturated solution in step 3?   .   ...   [2]  (v)  the equation for the reaction is shown. znco3(s)  +  h2so4(aq)    znso4(..)  +  h2o(l)  +  co2(g) \t \tcomplete\tthe\tequation\tby\tinserting\tthe\tstate\tsymbol\tfor\tzinc\tsulfate.\t [1]  (vi)\t\tname\tanother\tzinc\tcompound\t which\tcould\tbe\tused\tto\tmake\tzinc\tsulfate\tfrom\tdilute\t sulfuric acid using this method.   ...   [1]  (vii)  suggest why this method would not\t work\tto\tmake\tbarium\tsulfate\tfrom\tbarium\tcarbonate \t and dilute sulfuric acid.   ...   [1]",
            "7": "7 0620/42/o/n/18 \u00a9 ucles 2018 [turn over  (d)\t\tin\ta\ttitration,\ta\tstudent\tadded\t25.0\tcm3\tof\t0.200\tmol\t/\tdm3 aqueous sodium hydroxide to a  conical\tflask.\tthe\tstudent\tthen\tadded\ta\tfew\tdrops\tof\tmethyl\torange\tto\tthe\tsolution\tin\tthe\t conical\tflask. \t\tdilute\tsulfuric\tacid\twas\tthen\tadded\tfrom\ta\tburette\tto\tthe\tconical\tflask.\tthe\tvolume\tof\tdilute\t sulfuric\tacid\tneeded\tto\tneutralise\tthe\taqueous\tsodium\thydroxide\twas\t20.0\t cm3. 2naoh  +  h2so4    na2so4  +  2h2o  (i)  what was the colour of the methyl orange in the aqueous sodium hydroxide?   ...   [1]  (ii)\t\tdetermine\t the\tconcentration\tof\tthe\tdilute \tsulfuric\tacid\tin\tg\t /\tdm3. \t \u25cf\t\tcalculate\tthe\tnumber\tof\tmoles\tof\taqueous\tsodium\thydroxide\t added\tto\tthe\tconical\t flask.  .. mol \t \u25cf\t\tcalculate\tthe\tnumber\tof\tmoles\tof\tdilute\tsulfuric\tacid\tadded\tfrom\tthe\tburette.  .. mol \t \u25cf\t\tcalculate\tthe\tconcentration\tof\tthe\tdilute\tsulfuric\tacid\tin\tmol\t /\tdm3. \t ..\tmol\t /\tdm3 \t \u25cf\t\tcalculate\tthe\tconcentration\tof\tthe\tdilute\tsulfuric\tacid\tin\tg\t /\tdm3. \t ..\tg\t /\tdm3  [4]",
            "8": "8 0620/42/o/n/18 \u00a9 ucles 2018  (e)  iron( ii) sulfate decomposes when heated strongly. 2feso4(s)    fe2o3(s)  +  so2(g)  +  so3(g) \t\t15.20\tg\tof\tfeso4(s)\twas\theated\tand\tformed\t4.80\t g\tof\tfe2o3(s).  [mr,\tfeso4\t=\t152;\tmr,\tfe2o3\t=\t160]   calculate the percentage yield for this reaction.  .. %  [3]  [total: 26]",
            "9": "9 0620/42/o/n/18 \u00a9 ucles 2018 [turn over 4\t\ta\tstudent\tinvestigated\t the\tprogress\tof\tthe\treaction\tbetween\tdilute\thydrochloric\t acid,\thcl,\tand\tan\t excess\tof\tlarge\tpieces\tof\tmarble,\tcaco3,\tusing\tthe\tapparatus\tshown. gas syringe dilute hydrochloric acid an excess of large pieces of marble  (a)  a graph of the volume of gas produced against time is shown. 150 100 50 0volume of gas produced  / cm3 03 06 09 0120 time  / s150 180 210 240  (i)  how does the shape of the graph show that the rate of reaction decreased as the reaction  progressed?   .   ...   [1]  (ii)  why did the rate of reaction decrease as the reaction progressed?   ...   [1]  (iii)\t\tafter\thow\tmany\tseconds\tdid\tthe\treaction\tfinish?  .. s  [1]  (b)\t\tthe\texperiment\t was\trepeated\tusing\tthe\tsame\tmass\tof\tsmaller\tpieces\tof\tmarble.\tall\tother\t conditions were kept the same.   draw a graph on the grid to show the progress of the reaction using the smaller pieces of  marble.\t [2]",
            "10": "10 0620/42/o/n/18 \u00a9 ucles 2018  (c)  the original experiment was repeated at a higher temperature. all other conditions were kept  the same. \t\tdescribe\tand\texplain,\tin\tterms\tof\tcollisions\t between\tparticles,\t the\teffect\tof\tusing\ta\thigher\t temperature\ton\tthe\ttime\ttaken\tfor\tthe\treaction\tto\tfinish.                           .. \t\t[5] \t [total:\t10]",
            "11": "11 0620/42/o/n/18 \u00a9 ucles 2018 [turn over 5\t\talkynes\tare\ta\thomologous\tseries\tof\tunsaturated \thydrocarbons. \t\tall\tmembers\tcontain\ta\tc\u2261c\ttriple\tbond.  (a)\t\tcomplete\tthe\ttable\tshowing\tinformation\tabout\tthe\tfirst\tthree alkynes. formula c2h2 c3h4 structure h\u2013c\u2261c\u2013h h\u2013c\u2261c\u2013ch3h\u2013c\u2261c\u2013ch2\u2013ch3 name ethyne butyne  [2]  (b)\t\tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\ta\tmolecule\tof\tethyne,  h\u2013c\u2261c\u2013h.\tshow\touter\tshell\telectrons\tonly. h h c c  [2]  (c)  compounds in the same homologous series have the same general formula.  (i)  give two\tother\tcharacteristics\tof\tmembers\tof\ta\thomologous\tseries.  1  ..  2  ..  [2]  (ii)\t\tuse\tthe\tinformation\tin\tthe\ttable\tin\t (a) to deduce the general formula of alkynes.   ...   [1]  (d)  alkynes are unsaturated. \t\tdescribe\ta\ttest\tfor\tunsaturation.  test  .  result  ..  [2]",
            "12": "12 0620/42/o/n/18 \u00a9 ucles 2018  (e) (i)\t\tname\tan\toxidising\tagent\twhich\tcan\tbe\tused\tto\toxidise\tethanol\tto\tethanoic\tacid.   ...   [2]  (ii)\t\tdraw\tthe\tstructure\tof\tethanoic\tacid.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [1]  (f)\t\tcarboxylic\tacids\tcan\tbe\tconverted\tinto\testers.  (i)\t\tthe\tester\tformed\tby\treacting\tpropanoic\t acid\tand\tmethanol\t has\tthe\tmolecular\t formula\t c4h8o2. \t \tname\tthis\tester\tand\tdraw\tits\tstructure.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  name of the ester    structure of the ester  [2]  (ii)  name another ester with the molecular formula c4h8o2.   ...   [1]  (g)  polyesters are polymers.  (i)  what type of polymerisation is used in the manufacture of polyesters?   ...   [1]  (ii)  name a polyester.   ...   [1]  [total: 17]",
            "13": "13 0620/42/o/n/18 \u00a9 ucles 2018blank page",
            "14": "14 0620/42/o/n/18 \u00a9 ucles 2018blank page",
            "15": "15 0620/42/o/n/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "16": "16 0620/42/o/n/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w18_qp_43.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used. a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/43   paper 4  theory (extended) october/november 2018  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education this document consists of 11  printed pages and 1 blank page. [turn overib18 11_0620_43/3rp\u00a9 ucles 2018 *4284305988* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/43/o/n/18 \u00a9 ucles 2018 1  answer the following questions using only the substances in the list.   each substance may be used once, more than once or not at all.  ammonia bauxite carbon dioxide carbon monoxide  hematite oxygen sodium chloride sulfur dioxide   state which substance is:  (a)  an element  ...   [1]  (b)  an ore of iron  ...   [1]  (c)  used to bleach wood pulp     [1]  (d)  used to manufacture fertilisers     [1]  (e)  a toxic gas produced during the incomplete combustion of hydrocarbons    ..   [1]  (f)  an ionic compound  ..   [1]  (g)  a reactant in photosynthesis     [1]  (h)  a product of photosynthesis.     [1] [total: 8]",
            "3": "3 0620/43/o/n/18 \u00a9 ucles 2018 [turn over 2  this question is about electrolysis.  (a) (i)  what is meant by the term electrolysis ?   .   ...   [2]  (ii)  name the type of particle responsible for the conduction of electricity during electrolysis in:  the metal wires  ...  the electrolyte  . [2]  (b)  the table gives information about the products of the electrolysis of two electrolytes. platinum  electrodes are used in each case.  (i)  give two reasons why platinum is suitable to use as an electrode.  1  ..  2  ..  [2]  (ii)  complete the table. electrolyteobservation at the anode (+)name of product at the anode (+)observation at the cathode (\u2013)name of product at the cathode (\u2013) concentrated aqueous  potassium chloridebubbles of colourless gas aqueous copper( ii) sulfatebubbles of  colourless gas [6] [total: 12]",
            "4": "4 0620/43/o/n/18 \u00a9 ucles 2018 3  tin is a metallic element in group iv. its main ore is cassiterite which is an impure form of  tin(iv) oxide, sno2.   tin also occurs in stannite, cu2fesns4.  (a)  calculate the relative formula mass, mr, of cu2fesns4. mr of cu2fesns4 = ..  [1]  (b)  the mr of sno2 is 151.   calculate the percentage of tin by mass in sno2. percentage of tin by mass in sno2 = ..  [1]  (c)  the percentage of tin by mass in cu2fesns4 is 27.6%.   use this information and your answer to (b) to suggest whether it would be better to extract tin  from sno2 or cu2fesns4.   explain your answer.      ..   [1]  (d)  t in can be extracted by heating tin( iv) oxide with carbon. carbon monoxide is the other product.   write a chemical equation for this reaction.   ..   [2]  (e)  the position of tin in the reactivity series is shown.  iron most reactive  tin   copper least reactive   a student added iron to a solution containing sn2+ ions.   the student then separately added tin to a solution containing cu2+ ions.   complete the ionic equations. if there is no reaction write \u2018no reaction\u2019.  fe  +  sn2+     ...  sn  +  cu2+     ... [2]",
            "5": "5 0620/43/o/n/18 \u00a9 ucles 2018 [turn over  (f)  copper( ii) nitrate, cu(no3)2, decomposes when it is heated. the only solid product is  copper( ii) oxide, cuo. there are two gaseous products. one of the gaseous products is  oxygen.  (i)  describe a test for oxygen.  test  ..  result  ...  [2]  (ii)  name the other gaseous product. describe its appearance.  name  ...  appearance  .  [2]  (iii)  write a chemical equation for the thermal decomposition of copper( ii) nitrate.   ...   [1]  (g)  iron does not rust when it is completely coated with zinc. when the zinc is scratched, the iron  still does not rust.  (i)  explain why the iron does not rust when it is completely coated with zinc.   ...   [1]  (ii)  explain why the iron still does not rust when the zinc is scratched.   .   .   .   .   .   ...   [3] [total: 16]",
            "6": "6 0620/43/o/n/18 \u00a9 ucles 2018 4 (a)  dilute sulfuric acid and aqueous potassium hydroxide can be used to make potassium sulfate  crystals using a method that includes titration. conical flaskdilute sulfuric acid 25.0  cm3 of aqueous potassium hydroxide   a student titrated 25.0 cm3 of 0.0500 mol / dm3 aqueous potassium hydroxide with dilute  sulfuric acid in the presence of an indicator. the volume of dilute sulfuric acid needed to  neutralise the aqueous potassium hydroxide was 20.0 cm3.   the equation for the reaction is shown. h2so4  +  2koh    k2so4  +  2h2o   determine the concentration of the dilute sulfuric acid. \t \u25cf\t \tcalculate\tthe\tnumber\tof\tmoles\tof\taqueous\tpotassium\thydroxide\tused.  .. mol \t \u25cf\t \tcalculate\t the\tnumber\t of\tmoles\tof\tdilute\tsulfuric\tacid\tneeded  to neutralise the aqueous  potassium hydroxide.  .. mol \t \u25cf\t \tcalculate\tthe\tconcentration\tof\tthe\tdilute \tsulfuric\tacid.  .. mol / dm3 [3]",
            "7": "7 0620/43/o/n/18 \u00a9 ucles 2018 [turn over  (b)\t\tafter\tthe\ttitration\t has\tbeen\tcompleted,\t the\tconical\tflask\tcontains\t an\taqueous\t solution\t of\t potassium sulfate and some of the dissolved indicator.   describe how to prepare a pure, dry sample of potassium sulfate crystals from new solutions  of dilute sulfuric acid and aqueous potassium hydroxide of the same concentrations as used in  the titration. include a series of key steps in your answer.                     ..   [5]  (c)  potassium hydrogensulfate, khso4, is an acid salt. it dissolves in water to produce an aqueous  solution, x, containing k+, h+ and so42\u2013 ions.   describe what you would see when the following experiments are done.  (i)  magnesium ribbon is added to an excess of solution x.   .   ...   [2]  (ii)\t\ta\tflame\ttest\tis\tdone\ton\tsolution\t x.   ...   [1]  (iii)  an aqueous solution containing barium ions is added to solution x.   ...   [1]  (d)  dilute sulfuric acid reacts with bases, metals and carbonates.   write chemical equations for the reaction of dilute sulfuric acid with each of the following:  (i)  magnesium hydroxide   ...   [2]  (ii)  zinc   ...   [2]  (iii)  sodium carbonate   ...   [2] [total: 18]",
            "8": "8 0620/43/o/n/18 \u00a9 ucles 2018 5  a student investigates the rate of reaction between lumps of calcium carbonate and dilute  hydrochloric acid using the apparatus shown. caco3(s)  +  2hcl (aq)    cacl 2(aq)  +  co2(g)  +  h2o(l)   the calcium carbonate was in excess. dilute hydrochloric acidgas syringe lumps of calcium carbonate  (a)  which measurements should the student make during the reaction to determine the rate of  reaction?      ..   [2]  (b)  what happens to the rate of reaction as the reaction proceeds? explain your answer.            ..   [3]  (c)  the student repeated the experiment at a higher temperature. all other conditions were kept the same. the student found that the rate of reaction increased.   explain, in terms of collisions, why the rate of reaction increased.               ..   [4]  (d)  apart from using a higher temperature, suggest two other methods of increasing the rate of this reaction.  1  .  2  . [2] [total: 11]",
            "9": "9 0620/43/o/n/18 \u00a9 ucles 2018 [turn over 6 (a)  ethanol can be manufactured by fermentation and by hydration.  (i)  describe these two processes of ethanol manufacture.   in each case you should: \t \u25cf\t\tidentify\tthe\treactants \t \u25cf\t\tgive\tthe\treaction\tconditions \t \u25cf\t\twrite\ta\tchemical\tequation\tfor\tthe\treaction\twhich\tproduces\tethanol.   fermentation     .   .   .   .   hydration  .   .   .   .   . [6]  (ii)  give two advantages of ethanol manufacture by fermentation compared to by hydration.  1  ..  2  ..  [2]  (iii)  state two major uses of ethanol.  1  ..  2  .. [2]",
            "10": "10 0620/43/o/n/18 \u00a9 ucles 2018  (b)  the structures of some polymers are shown.  o o o o a co o co o co o b oo c co oo c co o o c nh co o n hch n oc d ch3ch ch2 ch3ch ch2 ch3ch ch2 e   answer the following questions about these polymers.   each polymer may be used once, more than once or not at all.   state which polymer, a, b, c, d or e, represents:  (i)  an addition polymer  ..   [1]  (ii)  a protein     [1]  (iii)  a polyester made from only one monomer  ...   [1]  (iv)  terylene  .   [1]  (v)  a complex carbohydrate.  ..   [1] [total: 15]",
            "11": "11 0620/43/o/n/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge. blank page",
            "12": "12 0620/43/o/n/18 \u00a9 ucles 2018 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w18_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51   paper 5  practical test october/november 2018  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib18 11_0620_51/fp\u00a9 ucles 2018 *9556806722* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/51/o/n/18 \u00a9 ucles 2018 1  you are going to investigate the rate of reaction between solution s and solution t at different  temperatures. when these chemicals react they form iodine. sodium thiosulfate solution and starch solution can be used to show how fast the reaction proceeds.   read all the instructions carefully before starting the experiments.  instructions   you are going to do four experiments.  experiment 1  \u25cf place the conical flask on the white tile. use measuring cylinder a to add 10 cm 3 of solution s  to the conical flask.  \u25cf use measuring cylinder b to add 20 cm3 of sodium thiosulfate solution to the conical flask.  \u25cf use the teat pipette to add about 1 cm3 of starch solution to the mixture.  \u25cf measure and record the initial temperature of the mixture in the table.  \u25cf use measuring cylinder c to start the reaction by adding 10 cm3 of solution t to the conical flask.  start the timer immediately and swirl the mixture.  \u25cf measure the time taken for the mixture to turn blue-black and record the time taken in the table.  \u25cf measure and record the final temperature of the mixture in the table.  \u25cf empty the conical flask and rinse it with distilled water.  experiment 2  \u25cf repeat experiment 1 but first heat the mixture of solution s, sodium thiosulfate solution and  starch solution in the conical flask to about 30 \u00b0c.  \u25cf measure and record the initial temperature of the mixture in the table.  \u25cf use measuring cylinder c to add 10 cm3 of solution  t to the conical flask. start the timer  immediately and swirl the mixture.  \u25cf measure the time taken for the mixture to turn blue-black and record the time taken in the table.  \u25cf measure and record the final temperature of the mixture in the table.  \u25cf empty the conical flask and rinse it with distilled water.  experiment 3  \u25cf repeat experiment 2 but first heat the mixture of solution s, sodium thiosulfate solution and  starch solution in the conical flask to about 40 \u00b0c before adding solution t.  experiment 4  \u25cf repeat experiment 2 but first heat the mixture of solution s, sodium thiosulfate solution and  starch solution in the conical flask to about 50 \u00b0c before adding solution t.  (a)  record your results from experiments 1\u20134 in the table. calculate the average temperatures to complete the table. experiment numberinitial temperature / \u00b0cfinal temperature / \u00b0caverage  temperature / \u00b0ctime taken for the mixture to turn blue-black / s 1 2 3 4  [4]",
            "3": "3 0620/51/o/n/18 \u00a9 ucles 2018 [turn over  (b)  plot your results for experiments 1\u20134 on the grid. draw a smooth line graph. 160 140 120 100 80 604020 0 01 02 03 0 average temperature  / \u00b0ctime taken for the mixture to turn blue-black  / s 40 50 60  [4]   (c)  from your graph, deduce the average temperature needed for the mixture to turn blue-black  in 60 s.   show clearly on the grid  how you worked out your answer.   ..   [3]",
            "4": "4 0620/51/o/n/18 \u00a9 ucles 2018  (d) (i)  in which experiment, 1, 2, 3 or 4, was the rate of reaction greatest?   ...   [1]  (ii)  explain, in terms of particles, why the rate of reaction was greatest in this experiment.   .   .   ...   [2]  (e)  pipettes or burettes could be used to measure the volumes of solution s and the  sodium thiosulfate solution more accurately.   state and explain one other way to improve the accuracy of the results of these experiments.  way to improve the accuracy  .  explanation       [2]  (f)  a student predicted that using a burette to add solution t would improve the accuracy of the  results of these experiments.   suggest why the student\u2019s prediction would not improve the accuracy of the results of these  experiments .      ..   [2]  [total: 18]",
            "5": "5 0620/51/o/n/18 \u00a9 ucles 2018 [turn over 2  you are provided with two solids, solid p and solid q.   do the following tests on solid p and solid q, recording all of your observations at each stage.  (a)  describe the appearance of:  solid p    solid q  ...  [1]  tests on solid p   divide solid p into three portions.  (b) (i)\t \tplace\tthe\tfirst\tportion\tof\tsolid\t p in a boiling tube. add a small piece of aluminium foil and  about 2 cm3 of aqueous sodium hydroxide to the boiling tube. heat the mixture and test the  gas produced with indicator paper.  record your observations.   .   .   ...   [2]  (ii)  use your results from (b)(i) to identify the gas produced.   ...   [1]  (c) (i)  place the second portion of solid p in a test-tube. add about 2 cm3 of distilled water to the  test-tube. stopper and shake the test-tube to dissolve solid p. add a few drops of dilute  nitric acid and about 1 cm3 of aqueous barium nitrate.   record your observations.   ...   [1]  (ii)  what conclusion can you draw about solid p from your observations in (c)(i)?   ...   [1]  (d)\t\tdo\ta\tflame\ttest\ton\tthe\tthird\tportion\tof\tsolid\t p.  record your observations.   ..   [1]  (e)  identify solid p.   ..   [2]",
            "6": "6 0620/51/o/n/18 \u00a9 ucles 2018  tests on solid q  (f)  heat about half of solid q in a hard glass test-tube.   record your observations.      ..   [2]   add about 4 cm3 of distilled water to the rest of solid q in a test-tube. stopper and shake the  test-tube to dissolve solid q.   divide the solution into two equal portions in two test-tubes.  (g) (i)\t \tadd\tan\texcess\tof\taqueous\t sodium\thydroxide\t to\tthe\tfirst\tportion\tof\tthe\tsolution.\t leave\tthe\t mixture to stand for approximately 5 minutes.   record your observations.   ...   [2]  (ii)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous silver nitrate to the second  portion of the solution.  record your observations.   ...   [1]  (h)  what conclusions can you draw about the identity of solid q?      ..   [2]  [total: 16]",
            "7": "7 0620/51/o/n/18 \u00a9 ucles 2018 [turn over 3  some cleaning products are mixtures. the three substances present in a cleaning product are  listed in the table. substancestate at room temperaturephysical property sodium carbonate solid melts at 858 \u00b0c ethanol liquid boils at 78 \u00b0c limonene liquid boils at 176 \u00b0c   use the information in the table to plan an experiment to obtain a sample of each substance from a mixture of the three substances.   you are provided with a mixture of the three substances and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   .   [6]  [total:6]",
            "8": "8 0620/51/o/n/18 \u00a9 ucles 2018blank page",
            "9": "9 0620/51/o/n/18 \u00a9 ucles 2018blank page",
            "10": "10 0620/51/o/n/18 \u00a9 ucles 2018blank page 2  you are provided with two metal salt solutions, e and f.   carry out the following tests on e and f, recording all of your observations at each stage.",
            "11": "11 0620/51/o/n/18 \u00a9 ucles 2018notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueousbarium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/51/o/n/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_w18_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52   paper 5  practical test october/november 2018  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib18 11_0620_52/3rp\u00a9 ucles 2018 *5553398427* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/52/o/n/18 \u00a9 ucles 2018blank page",
            "3": "3 0620/52/o/n/18 \u00a9 ucles 2018 [turn over 1  you are going to investigate the rate of reaction between solution l, solution m and hydrochloric acid.   when these chemicals react they form iodine. sodium thiosulfate solution and starch solution can  be used to show how fast the reaction proceeds.   read all the instructions carefully before starting the experiments.   instructions \t\tyou\tare\tgoing\tto\tdo\tfive\texperiments.  experiment 1  \u25cf place the conical flask on the white tile. use measuring cylinder a to add 10 cm3 of solution l  to the conical flask.  \u25cf now use measuring cylinder a to add 10 cm3 of dilute hydrochloric acid and 10 cm3 of  sodium thiosulfate solution to the conical flask.  \u25cf use the teat pipette to add about 1 cm3\tof\tstarch\tsolution\tto\tthe\tmixture.  \u25cf use measuring cylinder b to start the reaction by adding 10 cm3 of solution m to the conical  flask.\tstart\tthe\ttimer\timmediately\tand\tswirl\tthe\tmixture.  \u25cf\tmeasure\t the\ttime\ttaken\tfor\tthe\tmixture\tto\tturn\tblue-black\t and\trecord\tthe\ttime\ttaken\tin\tthe\ttable\t on page 4.  \u25cf empty the conical flask and rinse it with distilled water.  experiment 2  \u25cf place the conical flask on the white tile. use measuring cylinder a to add 8 cm3 of solution l  and 2 cm3 of distilled water to the conical flask.  \u25cf now use measuring cylinder a to add 10 cm3 of dilute hydrochloric acid and 10 cm3 of  sodium thiosulfate solution to the conical flask.  \u25cf use the teat pipette to add about 1 cm3\tof\tstarch\tsolution\tto\tthe\tmixture.  \u25cf use measuring cylinder b to add 10 cm3 of solution  m to the conical flask. start the timer  immediately\tand\tswirl\tthe\tmixture.  \u25cf\tmeasure\t the\ttime\ttaken\tfor\tthe\tmixture\tto\tturn\tblue-black\t and\trecord\tthe\ttime\ttaken\tin\tthe\ttable\t on page 4.  \u25cf empty the conical flask and rinse it with distilled water.  experiment 3  \u25cf\trepeat\texperiment\t 2\tbut\tadd\t6\tcm3 of solution l and 4 cm3 of distilled water to the conical flask  before adding the other reagents.  experiment 4  \u25cf\trepeat\texperiment\t 2\tbut\tadd\t5\tcm3 of solution l\tand\t5\tcm3 of distilled water to the conical flask  before adding the other reagents.  experiment 5  \u25cf\trepeat\texperiment\t 2\tbut\tadd\t3\tcm3 of solution l and 7 cm3 of distilled water to the conical flask  before adding the other reagents.",
            "4": "4 0620/52/o/n/18 \u00a9 ucles 2018  (a)\t\trecord\tyour\tresults\tfrom\texperiments\t1\u20135\tin\tthe\ttable. experiment numbervolume of solution l / cm3volume of distilled water / cm3time\ttaken\tfor\tthe\tmixture to\tturn\tblue-black\t /\ts 1 10 0 2 8 2 3 6 4 4 5 5 5 3 7  [4]",
            "5": "5 0620/52/o/n/18 \u00a9 ucles 2018 [turn over  (b)\t\tplot\tyour\tresults\tfor\texperiments\t1\u20135\ton\tthe\tgrid.\tdraw\ta\tsmooth\tline\tgraph. 180 160 140 120100 80 60 40 20 0 0246 volume of solution  l / cm3time taken for the mixture toturn blue-black  / s 81 0  [4]  (c)  from your graph,\t deduce\tthe\ttime\ttaken\tfor\tthe\tmixture\tto\tturn\tblue-black\t if\texperiment\t 2\t were repeated using 4 cm3 of solution l\tand\t6\t cm3 of distilled water.   show clearly on the grid  how you worked out your answer.   ..   [3]",
            "6": "6 0620/52/o/n/18 \u00a9 ucles 2018  (d) (i)\t \tin\twhich\texperiment,\t1,\t2,\t3,\t4\tor\t5,\twas\tthe\trate\tof\treaction\tgreatest?   ...   [1]  (ii)\t\texplain,\tin\t terms\tof\tparticles,\twhy\tthe\trate\tof\treaction\twas\tgreatest\tin\tthis\texperiment.   .   .   ...   [2]  (e) (i) suggest an advantage of using a graduated pipette instead of measuring cylinder a.    ...   [1]  (ii)\t\tsuggest\t and\texplain\ta\tdisadvantage\t of\tusing\ta\tgraduated\t pipette\tinstead\tof\tmeasuring\t cylinder b.   .   ...   [2]  (f)  suggest one\tway\tto\timprove\tthe\treliability\tof\tthe\tresults\tof\tthese\texperiments.   ..   [1]  [total: 18]",
            "7": "7 0620/52/o/n/18 \u00a9 ucles 2018 [turn over 2  you are provided with two solids, solid n and solid o.\t do\tthe\tfollowing\t tests\ton\tsolid\t n and solid o,  recording all of your observations at each stage.  (a)\t\tdescribe\tthe\tappearance\tof:  solid n    solid o   [1]   tests on solid n \t\tdivide\tsolid\t n into three portions.  (b)\t\tplace\tthe\tfirst\tportion\tof\tsolid\t n\tin\ta\thard\tglass\ttest-tube.\t heat\tsolid\t n gently and then strongly.  test the gas produced with indicator paper.   record your observations.            ..   [3]  (c)  place the second portion of solid n\t in\ta\ttest-tube.\t add\tabout\t2\tcm3 of distilled water to the  test-tube.\t stopper\t and\tshake\tthe\ttest-tube\t to\tdissolve\t solid\t n.\tadd\ta\tfew\tdrops\tof\tdilute\t nitric acid and about 1 cm3 of aqueous barium nitrate.   record your observations.   ..   [2]  (d)  place the third portion of solid n\tin\ta\tboiling\ttube.\tadd\tan\texcess\tof\taqueous\t sodium\thydroxide\t to\tthe\tboiling\ttube.\theat\tthe\tmixture\tand\ttest\tthe\tgas\tproduced.   record your observations.      ..   [2]  (e)  name the gas produced in (d).   ..   [1]  (f)  identify solid n.   ..   [2]",
            "8": "8 0620/52/o/n/18 \u00a9 ucles 2018  tests on solid o \t\tdivide\tsolid\t o into two portions. \t\tplace\tthe\tfirst\tportion\tof\tsolid\t o\tin\ta\ttest-tube.\t add\tabout\t4\tcm3\tof\tdistilled\twater\tto\tthe\ttest-tube.\t stopper\tand\tshake\tthe\ttest-tube\tto\tdissolve\tsolid\t o. \t\tdivide\tthe\tsolution\tinto\ttwo\tequal\tportions\tin\ttwo \ttest-tubes.  (g)\t\tadd\tan\texcess\tof\taqueous\tsodium\thydroxide\tto\tthe \tfirst\tportion\tof\tthe\tsolution.   record your observations.   ..   [1]  (h)\t\tadd\ta\tfew\tdrops\tof\tdilute\tnitric\tacid\tand\tabout\t1\tcm3 of aqueous silver nitrate to the second  portion of the solution.   record your observations.   ..   [1]  (i)\t\tdo\ta\tflame\ttest\ton\tthe\trest\tof\tsolid\to.   record your observations.   ..   [1]  (j)  identify solid o.   ..   [2] \t [total:\t16]",
            "9": "9 0620/52/o/n/18 \u00a9 ucles 2018 [turn over 3  when solid c and solid  d\tseparately\t react\twith\tdilute\thydrochloric\t acid,\tone\treaction\t is\texothermic\t and one reaction is endothermic.   plan an investigation to determine:  \u25cf\twhich\treaction\t \tis\texothermic\tand\twhich\treaction\tis\tendothermic  \u25cf which energy change is greater.   you are provided with solid c and solid d, dilute hydrochloric acid and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6] \t [total:\t6]",
            "10": "10 0620/52/o/n/18 \u00a9 ucles 2018blank page",
            "11": "11 0620/52/o/n/18 \u00a9 ucles 2018notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh 4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/52/o/n/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_w18_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53   paper 5  practical test october/november 2018  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge international examinations cambridge international general certificate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib18 11_0620_53/3rp\u00a9 ucles 2018 *7959987048* the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/53/o/n/18 \u00a9 ucles 2018 1  you are going to investigate the rate of reaction between solution s and solution t at different  temperatures. when these chemicals react they form iodine. sodium thiosulfate solution and starch solution can be used to show how fast the reaction proceeds.   read all the instructions carefully before starting the experiments.  instructions   you are going to do four experiments.  experiment 1  \u25cf place the conical flask on the white tile. use measuring cylinder a to add 10 cm 3 of solution s  to the conical flask.  \u25cf use measuring cylinder b to add 20 cm3 of sodium thiosulfate solution to the conical flask.  \u25cf use the teat pipette to add about 1 cm3 of starch solution to the mixture.  \u25cf measure and record the initial temperature of the mixture in the table.  \u25cf use measuring cylinder c to start the reaction by adding 10 cm3 of solution t to the conical flask.  start the timer immediately and swirl the mixture.  \u25cf measure the time taken for the mixture to turn blue-black and record the time taken in the table.  \u25cf measure and record the final temperature of the mixture in the table.  \u25cf empty the conical flask and rinse it with distilled water.  experiment 2  \u25cf repeat experiment 1 but first heat the mixture of solution s, sodium thiosulfate solution and  starch solution in the conical flask to about 30 \u00b0c.  \u25cf measure and record the initial temperature of the mixture in the table.  \u25cf use measuring cylinder c to add 10 cm3 of solution  t to the conical flask. start the timer  immediately and swirl the mixture.  \u25cf measure the time taken for the mixture to turn blue-black and record the time taken in the table.  \u25cf measure and record the final temperature of the mixture in the table.  \u25cf empty the conical flask and rinse it with distilled water.  experiment 3  \u25cf repeat experiment 2 but first heat the mixture of solution s, sodium thiosulfate solution and  starch solution in the conical flask to about 40 \u00b0c before adding solution t.  experiment 4  \u25cf repeat experiment 2 but first heat the mixture of solution s, sodium thiosulfate solution and  starch solution in the conical flask to about 50 \u00b0c before adding solution t.  (a)  record your results from experiments 1\u20134 in the table. calculate the average temperatures to complete the table. experiment numberinitial temperature / \u00b0cfinal temperature / \u00b0caverage  temperature / \u00b0ctime taken for the mixture to turn blue-black / s 1 2 3 4  [4]",
            "3": "3 0620/53/o/n/18 \u00a9 ucles 2018 [turn over  (b)  plot your results for experiments 1\u20134 on the grid. draw a smooth line graph. 160 140 120 100 80 604020 0 01 02 03 0 average temperature  / \u00b0ctime taken for the mixture to turn blue-black  / s 40 50 60  [4]   (c)  from your graph, deduce the average temperature needed for the mixture to turn blue-black  in 60 s.   show clearly on the grid  how you worked out your answer.   ..   [3]",
            "4": "4 0620/53/o/n/18 \u00a9 ucles 2018  (d) (i)  in which experiment, 1, 2, 3 or 4, was the rate of reaction greatest?   ...   [1]  (ii)  explain, in terms of particles, why the rate of reaction was greatest in this experiment.   .   .   ...   [2]  (e)  pipettes or burettes could be used to measure the volumes of solution s and the  sodium thiosulfate solution more accurately.   state and explain one other way to improve the accuracy of the results of these experiments.  way to improve the accuracy  .  explanation       [2]  (f)  a student predicted that using a burette to add solution t would improve the accuracy of the  results of these experiments.   suggest why the student\u2019s prediction would not improve the accuracy of the results of these  experiments .      ..   [2]  [total: 18]",
            "5": "5 0620/53/o/n/18 \u00a9 ucles 2018 [turn over 2  you are provided with two solids, solid p and solid q.   do the following tests on solid p and solid q, recording all of your observations at each stage.  (a)  describe the appearance of:  solid p    solid q  ...  [1]  tests on solid p   divide solid p into three portions.  (b) (i)\t \tplace\tthe\tfirst\tportion\tof\tsolid\t p in a boiling tube. add a small piece of aluminium foil and  about 2 cm3 of aqueous sodium hydroxide to the boiling tube. heat the mixture and test the  gas produced with indicator paper.  record your observations.   .   .   ...   [2]  (ii)  use your results from (b)(i) to identify the gas produced.   ...   [1]  (c) (i)  place the second portion of solid p in a test-tube. add about 2 cm3 of distilled water to the  test-tube. stopper and shake the test-tube to dissolve solid p. add a few drops of dilute  nitric acid and about 1 cm3 of aqueous barium nitrate.   record your observations.   ...   [1]  (ii)  what conclusion can you draw about solid p from your observations in (c)(i)?   ...   [1]  (d)\t\tdo\ta\tflame\ttest\ton\tthe\tthird\tportion\tof\tsolid\t p.  record your observations.   ..   [1]  (e)  identify solid p.   ..   [2]",
            "6": "6 0620/53/o/n/18 \u00a9 ucles 2018  tests on solid q  (f)  heat about half of solid q in a hard glass test-tube.   record your observations.      ..   [2]   add about 4 cm3 of distilled water to the rest of solid q in a test-tube. stopper and shake the  test-tube to dissolve solid q.   divide the solution into two equal portions in two test-tubes.  (g) (i)\t \tadd\tan\texcess\tof\taqueous\t sodium\thydroxide\t to\tthe\tfirst\tportion\tof\tthe\tsolution.\t leave\tthe\t mixture to stand for approximately 5 minutes.   record your observations.   ...   [2]  (ii)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous silver nitrate to the second  portion of the solution.  record your observations.   ...   [1]  (h)  what conclusions can you draw about the identity of solid q?      ..   [2]  [total: 16]",
            "7": "7 0620/53/o/n/18 \u00a9 ucles 2018 [turn over 3  some cleaning products are mixtures. the three substances present in a cleaning product are  listed in the table. substancestate at room temperaturephysical property sodium carbonate solid melts at 858 \u00b0c ethanol liquid boils at 78 \u00b0c limonene liquid boils at 176 \u00b0c   use the information in the table to plan an experiment to obtain a sample of each substance from a mixture of the three substances.   you are provided with a mixture of the three substances and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   .   [6]  [total:6]",
            "8": "8 0620/53/o/n/18 \u00a9 ucles 2018blank page",
            "9": "9 0620/53/o/n/18 \u00a9 ucles 2018blank page",
            "10": "10 0620/53/o/n/18 \u00a9 ucles 2018blank page 2  you are provided with two metal salt solutions, e and f.   carry out the following tests on e and f, recording all of your observations at each stage.",
            "11": "11 0620/53/o/n/18 \u00a9 ucles 2018notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueousbarium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/53/o/n/18 \u00a9 ucles 2018permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge.tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless"
        },
        "0620_w18_qp_61.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib18 11_0620_61/3rp \u00a9 ucles 2018 *5730558021* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61   paper 6  alternative to practical october/november 2018  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/61/o/n/18 \u00a9 ucles 2018 1  a student obtains pure, dry samples of sand and sodium chloride from a mixture of sand and  sodium chloride.   the student uses the apparatus shown. the method consists of six steps, a, b, c, d, e and f,  which are shown in the wrong order. mixture of sand and sodium chloriderinse the sand with waterab add water and stirc heat to evaporateleave the sand to dry on filter paperde f heat.  (a)  order the steps in the method. a    .    .    .    .    .  [2]  (b)  complete the box to name the apparatus in d. [1]  (c)  why is the sand rinsed with water in b?      ..   [1]  (d)  name the process in f.   ..   [1]  (e)  how could the purity of the sodium chloride obtained be checked?   ..   [1]  [total: 6]",
            "3": "3 0620/61/o/n/18 \u00a9 ucles 2018 [turn over 2  a student investigated the rate of reaction between dilute nitric acid and lumps of   magnesium carbonate. the apparatus shown was used. balanc ecotton wool dilute nitric acid lumps of magnesium carbonat e \t\tlumps\tof\tmagnesium\t carbonate\t were\tadded\tto\ta\tconical\tflask.\t40\tcm3 of dilute nitric acid was  then\tpoured\tinto\tthe\tconical\tflask\tusing\ta\tmeasuring \tcylinder.\t the\tmagnesium\t carbonate\t was\tin\t excess . \t\tthe\tconical\tflask\twas\tplaced\ton\ta\tbalance.\tcotton\twool\twas\tplaced\tin\tthe\ttop\tof\tthe\tconical\tflask. \t\tthe\tmass\tof\tthe\tconical\tflask\tand\tits\tcontents\t was\tmeasured\t and\ta\ttimer\twas\tstarted.\tthe\tmass\tof\t the\tconical\tflask\tand\tits\tcontents\twas\tmeasured\tevery\tminute\tfor\t7\tminutes.",
            "4": "4 0620/61/o/n/18 \u00a9 ucles 2018  (a)\t\tuse\tthe\tbalance\t diagrams\t to\trecord\tthe\tmass\tof\tthe\tconical\tflask\tand\tits\tcontents\t in\tthe\ttable. \t \tcomplete\t the\ttable\tto\twork\tout\tthe\ttotal\tloss\tof\tmass\tof\tthe\tconical\tflask\tand\tits\tcontents\t since\t the start of the experiment. 86858687 gtime  / minutes 0balance diagrammass of conical flask and its contents  / gtotal loss of mass  / g 848586 838485g1 838485 g2 838485 g3 g4 838485 g 838485 g 838485 g5 6 7  [3]",
            "5": "5 0620/61/o/n/18 \u00a9 ucles 2018 [turn over  (b)  plot the results on the grid. draw a smooth line graph. 2.5 2.0 1.5 1.0 0.5 0 0123 time  / minutestotal loss of mass  / g 456 7  [3]  (c)  the average rate of reaction can be calculated using the equation shown. average rate of reaction =total loss of mass / g time taken / s \t \tcalculate\tthe\taverage\trate\tof\treaction\tfor\tthe\tfirst\t30\t seconds of the reaction.   deduce the unit. rate = .. unit = ..  [3]  (d)  the experiment is repeated using an excess of powdered magnesium carbonate. all other  conditions are kept the same.   sketch on the grid the graph you would expect. [2]",
            "6": "6 0620/61/o/n/18 \u00a9 ucles 2018  (e) (i)\t \twhy\tdoes\tthe\tmass\tof\tthe\tconical\tflask\t and\tits\tcontents\tdecrease?   .   ...   [1]  (ii)  suggest the purpose of the cotton wool.   .   .   ...   [2]  (iii)  why does the graph level off? explain your answer.   .   ...   [2]  (f)  give one advantage and one disadvantage of using a burette instead of a measuring cylinder  to\tadd\tthe\tdilute\tnitric\tacid\tto\tthe\tconical\tflask.  advantage  ..  disadvantage  .  [2]  [total: 18]",
            "7": "7 0620/61/o/n/18 \u00a9 ucles 2018 [turn over 3  two solid salts, solid g and solid h, were analysed. tests were done on each solid.   tests on solid g   some of the tests and observations are shown. tests on solid g observations test 1 a\tflame\ttest\twas\tdone\ton\tsolid\t g. lilac colour solid g was dissolved in distilled water.test 2dilute hydrochloric acid was added to the  solution. the solution was warmed gently.  the\tgas\tproduced\t was\ttested\twith\tfilter\tpaper\t which\thad\tbeen\tdipped\tin\tacidified\t aqueous\t potassium manganate( vii).filter\tpaper\tturned\tfrom\tpurple\tto\tcolourless  (a)  name the gas produced in test 2.   ..   [1]  (b)  identify solid g.      ..   [2]",
            "8": "8 0620/61/o/n/18 \u00a9 ucles 2018  tests on solid h   solid h was calcium nitrate.   complete the expected observations.   solid h was added to distilled water in a test-tube. the test-tube was shaken to dissolve solid h.  the solution was divided into four portions in four test-tubes.  (c) (i)\t \tdrops\tof\taqueous\tsodium\thydroxide\twere\tadded\tto\tthe\tfirst\tportion\tof\tthe\tsolution.  observations  .   [2]  (ii)  an excess of aqueous sodium hydroxide was then added to the mixture from (c)(i).  observations  ..   [1]  (d)  an excess of aqueous ammonia was added to the second portion of the solution.  observations  .   [1]  (e)  dilute nitric acid and aqueous silver nitrate were added to the third portion of the solution.  observations  .   [1]  (f)  aluminium foil and aqueous sodium hydroxide were added to the fourth portion of the solution.  the mixture was warmed and the gas produced was tested.  observations  ...   ..   [2] \t [total:\t10]",
            "9": "9 0620/61/o/n/18 \u00a9 ucles 2018 [turn over 4  propanone and ethyl ethanoate are both solvents which can be used to remove paint.   plan an investigation to determine which of these two solvents is better to use to remove paint.   you are provided with glass slides, paint, the two solvents and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]  [total: 6]",
            "10": "10 0620/61/o/n/18 \u00a9 ucles 2018blank page",
            "11": "11 0620/61/o/n/18 \u00a9 ucles 2018blank page",
            "12": "12 0620/61/o/n/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        },
        "0620_w18_qp_62.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib18 11_0620_62/3rp \u00a9 ucles 2018 *7208760726* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62   paper 6  alternative to practical october/november 2018  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/o/n/18 \u00a9 ucles 2018 1  magnesium ribbon was burned in air. magnesium burning .  (a)  complete the box to name the apparatus. [1]  (b)  suggest the appearance of the product formed when the magnesium ribbon was burned in air.   ..   [1]  (c)  name the product formed when the magnesium ribbon was burned in air.   ..   [1]   the product from burning the magnesium ribbon in air was added to water and heated. the solution  formed was tested with universal indicator solution.  (d)  suggest why the product was heated after it had been added to water. explain your answer.      ..   [2]  (e)  suggest the ph value shown when universal indicator was added to the mixture.   ..   [1]  (f)  state one safety precaution that should be taken when magnesium is burned in air.   ..   [1]  [total: 7]",
            "3": "3 0620/62/o/n/18 \u00a9 ucles 2018 [turn over 2  a student investigated the rate of reaction between solution l, solution m and hydrochloric acid.   when these chemicals react they form iodine. sodium thiosulfate solution and starch solution were  used to show how fast the reaction proceeded.   five experiments were done.  experiment 1  \u25cf a measuring cylinder was used to add 10 cm3 of solution l to a conical flask.  \u25cf 10 cm3 of dilute hydrochloric acid, 10 cm3 of sodium thiosulfate solution and 1 cm3 of  starch solution were then added to the conical flask.  \u25cf the reaction was started by using a measuring cylinder to add 10 cm3 of solution m to the  conical flask. a timer was started immediately and the mixture was swirled.  \u25cf the time taken for the mixture to turn blue-black was measured.  \u25cf the conical flask was emptied and rinsed with distilled water.  experiment 2  \u25cf a measuring cylinder was used to add 8 cm3 of solution l and 2 cm3 of distilled water to the  conical flask.  \u25cf 10 cm3 of dilute hydrochloric acid, 10 cm3 of sodium thiosulfate solution and 1 cm3 of  starch solution were then added to the conical flask.  \u25cf the reaction was started by using a measuring cylinder to add 10 cm3 of solution m to the  conical flask. the timer was started immediately and the mixture was swirled.  \u25cf the time taken for the mixture to turn blue-black was measured.  \u25cf the conical flask was emptied and rinsed with distilled water.  experiment 3  \u25cf experiment 2 was repeated but 6 cm3 of solution l and 4 cm3 of distilled water were added to  the conical flask before adding the other reagents.  experiment 4  \u25cf experiment 2 was repeated but 5 cm3 of solution l and 5 cm3 of distilled water were added to  the conical flask before adding the other reagents.  experiment 5  \u25cf experiment 2 was repeated but 3 cm3 of solution l and 7 cm3 of distilled water were added to  the conical flask before adding the other reagents.",
            "4": "4 0620/62/o/n/18 \u00a9 ucles 2018  (a)  use the stop-clock diagrams to record the time taken for each experiment in the table. experiment  numbervolume of solution l / cm3volume of distilled water / cm3stop-clock diagramtime taken for the mixture to turn blue-black / s 1 10 00 0 10 3015 1545 5second s minutes 2 8 20 0 10 3015 1545 5 3 6 40 0 10 3015 1545 5 4 5 50 0 10 3015 1545 5 5 3 70 0 10 3015 1545 5  [4]",
            "5": "5 0620/62/o/n/18 \u00a9 ucles 2018 [turn over  (b)  plot the results for experiments 1\u20135 on the grid. draw a smooth line graph. 140 120 100 80 604020 0 0246 volume of solution l / cm3time taken for the mixture to turn blue-black  / s 81 0  [4]  (c)  from your graph, deduce the time taken for the mixture to turn blue-black if experiment 2  were repeated using 4 cm3 of solution l and 6 cm3 of distilled water.   show clearly on the grid  how you worked out your answer.   ..   [3]",
            "6": "6 0620/62/o/n/18 \u00a9 ucles 2018  (d) (i)  in which experiment, 1, 2, 3, 4 or 5, was the rate of reaction greatest?   ...   [1]  (ii)  explain, in terms of particles, why the rate of reaction was greatest in this experiment.   .   .   ...   [2]  (e) (i)  suggest an advantage of using a graduated pipette instead of a measuring cylinder to  measure solution l.   ...   [1]  (ii)  suggest and explain a disadvantage of using a graduated pipette instead of a measuring  cylinder to measure solution m.   .   ...   [2]  (f)  suggest one way to improve the reliability of the results of these experiments.   ..   [1]  [total: 18]",
            "7": "7 0620/62/o/n/18 \u00a9 ucles 2018 [turn over 3  solid n and solid o were analysed. solid n was ammonium sulfate. tests were done on each solid.   tests on solid n   complete the expected observations.  (a)  describe the appearance of solid n.   ..   [1]   solid n was dissolved in distilled water to form solution n. solution n was divided into two portions  in two test-tubes.  (b)\t\tdilute\tnitric\tacid\tand\taqueous\tbarium\tnitrate\twere\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t n.  observations     [2]  (c)  aqueous sodium hydroxide was added to the second portion of solution n. the mixture was  heated and the gas produced was tested.  observations  ..   ..   [2]  (d)  name the gas produced in (c).   ..   [1]",
            "8": "8 0620/62/o/n/18 \u00a9 ucles 2018  tests on solid o   some of the tests and observations are shown. tests on solid o observations the appearance of solid o was studied. white crystals distilled water was added to some of solid o to  form solution o. solution o was divided into two equal portions in  two test-tubes. test 1 an excess of aqueous sodium hydroxide was  added\tto\tthe\tfirst\tportion\tof\tsolution\t o.no reaction test 2dilute nitric acid and aqueous silver nitrate were  added to the second portion of solution o.white precipitate test 3 a\tflame\ttest\twas\tdone\ton\tthe\trest\tof\tsolid\to. lilac colour  (e)  what conclusion can you draw about the identity of solid o from test 1?   ..   [1]  (f)  identify solid o.   ..   [2]  [total: 9]",
            "9": "9 0620/62/o/n/18 \u00a9 ucles 2018 [turn over 4  when solid c and solid  d separately react with dilute hydrochloric acid, one reaction is exothermic  and one reaction is endothermic.   plan an investigation to determine:  \u25cf which reaction is exothermic and which reaction is endothermic  \u25cf which energy change is greater.   you are provided with solid c and solid d, dilute hydrochloric acid and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]  [total: 6]",
            "10": "10 0620/62/o/n/18 \u00a9 ucles 2018blank page",
            "11": "11 0620/62/o/n/18 \u00a9 ucles 2018blank page",
            "12": "12 0620/62/o/n/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        },
        "0620_w18_qp_63.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib18 11_0620_63/3rp \u00a9 ucles 2018 *2544440030* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63   paper 6  alternative to practical october/november 2018  1 hour candidates answer on the question paper. no additional materials are required.cambridge international examinations cambridge international general certificate of secondary education the syllabus is approved for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/63/o/n/18 \u00a9 ucles 2018 1  a sample of copper was prepared from lumps of copper( ii)\u00a0carbonate.\u00a0 the\u00a0first\u00a0step\u00a0was\u00a0to\u00a0make\u00a0 a solution of copper( ii) nitrate as shown. carbon dioxide was produced. . .dilute nitric acid lumps of copper( ii) carbonate  (a)  complete the boxes to name the apparatus. [2]  (b)  describe a test for carbon dioxide.  test  .  result  ..  [2]  (c)  explain why the lumps of copper( ii) carbonate were crushed before adding the dilute nitric acid.      ..   [2]  (d)  suggest how a sample of copper could be obtained from the solution of copper( ii) nitrate.  explain your suggestion.         ..   [2]  [total: 8]",
            "3": "3 0620/63/o/n/18 \u00a9 ucles 2018 [turn over 2  a student investigated the rate of reaction between solution s and solution t at different temperatures.   when these chemicals react they form iodine. sodium thiosulfate solution and starch solution were  used to show how fast the reaction proceeded.   four experiments were done.  experiment 1  \u25cf a measuring cylinder was used to add 10 cm3 of solution s and 10 cm3 of sodium thiosulfate  solution\u00a0to\u00a0a\u00a0conical\u00a0flask.  \u25cf a teat pipette was then used to add 1 cm3 of starch solution to the mixture.  \u25cf the temperature of the mixture was measured and recorded in the table.  \u25cf the reaction was started by using a measuring cylinder to add 10 cm3 of solution t to the  conical\u00a0flask.\u00a0 a\u00a0timer\u00a0was\u00a0started\u00a0immediately\u00a0and\u00a0the\u00a0mixture\u00a0was\u00a0swirled.  \u25cf\u00a0the\u00a0time\u00a0taken\u00a0for\u00a0the\u00a0mixture\u00a0to\u00a0turn\u00a0blue-black\u00a0was\u00a0measured.  \u25cf the final temperature of the mixture was measured and recorded.  \u25cf\u00a0the\u00a0conical\u00a0flask\u00a0was\u00a0emptied\u00a0and\u00a0rinsed\u00a0with\u00a0distilled\u00a0water.  experiment 2  \u25cf a measuring cylinder was used to add 10 cm3 of solution s and 10 cm3 of sodium thiosulfate  solution\u00a0to\u00a0the\u00a0conical\u00a0flask.  \u25cf a teat pipette was then used to add 1 cm3 of starch solution to the mixture.  \u25cf the mixture was then heated to about 30 \u00b0c.  \u25cf the temperature of the mixture was measured and recorded in the table.  \u25cf the reaction was started by using a measuring cylinder to add 10 cm3 of solution t to the  conical\u00a0flask.\u00a0 the\u00a0timer\u00a0was\u00a0started\u00a0immediately\u00a0and\u00a0the\u00a0mixture\u00a0was\u00a0swirled.  \u25cf\u00a0the\u00a0time\u00a0taken\u00a0for\u00a0the\u00a0mixture\u00a0to\u00a0turn\u00a0blue-black\u00a0was\u00a0measured.  \u25cf the final temperature of the mixture was measured and recorded.  \u25cfthe\u00a0conical\u00a0flask\u00a0was\u00a0emptied\u00a0and\u00a0rinsed\u00a0with\u00a0distilled\u00a0water.  experiment 3  \u25cf experiment 2 was repeated but the mixture of solution s, sodium thiosulfate solution and  starch\u00a0solution\u00a0in\u00a0the\u00a0conical\u00a0flask\u00a0was\u00a0heated\u00a0to\u00a0about\u00a040\u00a0 \u00b0c before adding solution t.  experiment 4  \u25cf experiment 2 was repeated but the mixture of solution s, sodium thiosulfate solution and  starch\u00a0solution\u00a0in\u00a0the\u00a0conical\u00a0flask\u00a0was\u00a0heated\u00a0to\u00a0about\u00a050\u00a0 \u00b0c before adding solution t.",
            "4": "4 0620/63/o/n/18 \u00a9 ucles 2018  (a)  calculate the average temperatures in the table. \u00a0 \u00a0 use\u00a0the\u00a0stop-clock\u00a0diagrams\u00a0to\u00a0record\u00a0the\u00a0time\u00a0taken\u00a0for\u00a0each\u00a0experiment\u00a0in\u00a0the\u00a0table. experiment numberinitial temperature / \u00b0cfinal temperature / \u00b0caverage temperature / \u00b0cstop-clock\u00a0diagramtime\u00a0taken\u00a0for the mixture to turn\u00a0blue-black\u00a0 /\u00a0s 1 22 220 0 10 3015 1545 5seconds minutes 2 31 290 0 10 3015 1545 5 3 41 370 0 10 3015 1545 5 4 51 450 0 10 3015 1545 5 \u00a0 [4]",
            "5": "5 0620/63/o/n/18 \u00a9 ucles 2018 [turn over  (b)\u00a0 \u00a0plot\u00a0the\u00a0results\u00a0for\u00a0experiments\u00a01\u2013\u00a0 4\u00a0on\u00a0the\u00a0grid.\u00a0draw\u00a0a\u00a0smooth\u00a0line\u00a0graph. 120 100 80 60 4020 0 01 02 03 0 average temperature  / \u00b0ctime taken for the mixture toturn blue-black  / s 40 50 60 \u00a0 [4]  (c)  from your graph,\u00a0 deduce\u00a0the\u00a0average\u00a0 temperature\u00a0 needed\u00a0for\u00a0the\u00a0mixture\u00a0to\u00a0turn\u00a0blue-black\u00a0 in 60 s.   show clearly on the grid \u00a0how\u00a0you\u00a0worked\u00a0out\u00a0your\u00a0answer.   ..   [3]  (d) (i)\u00a0 \u00a0 in\u00a0which\u00a0experiment,\u00a01,\u00a02,\u00a03\u00a0or\u00a04,\u00a0was\u00a0the\u00a0rate\u00a0of\u00a0reaction\u00a0greatest?   ...   [1]  (ii)  explain, in terms of particles, why the rate of reaction was greatest in this experiment.   .   .   ...   [2]",
            "6": "6 0620/63/o/n/18 \u00a9 ucles 2018  (e)  pipettes or burettes could be used to measure the volumes of solution s and the  sodium thiosulfate solution more accurately.   state and explain one other way to improve the accuracy of the results of these experiments.  way to improve the accuracy  .  explanation       [2]  (f)  a student predicted that using a burette to add solution t would improve the accuracy of the  results of these experiments.   suggest why the student\u2019s prediction would not improve the accuracy of the results of these  experiments .      ..   [2]  [total: 18]",
            "7": "7 0620/63/o/n/18 \u00a9 ucles 2018 [turn over 3  solid p and solid q were analysed. solid p was lithium nitrate. tests were done on each solid.   tests on solid p   complete the expected observations.  (a)  describe the appearance of solid p.   ..   [1]   solid p was divided into three portions.  (b)\u00a0 \u00a0aqueous\u00a0 sodium\u00a0hydroxide\u00a0 and\u00a0a\u00a0small\u00a0piece\u00a0of\u00a0aluminium\u00a0 foil\u00a0were\u00a0added\u00a0to\u00a0the\u00a0first\u00a0portion\u00a0 of solid p. the mixture was heated and the gas produced was tested.  observations  ..      ..   [3]  (c)  the second portion of solid p was dissolved in distilled water. dilute nitric acid and aqueous  barium nitrate were then added to the solution.  observations     [1]  (d)\u00a0 \u00a0a\u00a0flame\u00a0test\u00a0was\u00a0done\u00a0on\u00a0the\u00a0third\u00a0portion\u00a0of\u00a0solid\u00a0 p.  observations     [1]",
            "8": "8 0620/63/o/n/18 \u00a9 ucles 2018  tests on solid q   some of the tests and observations are shown. tests on solid q observations the appearance of solid q was studied. pink\u00a0crystals solid q\u00a0was\u00a0heated\u00a0in\u00a0a\u00a0hard\u00a0glass\u00a0test-tube. condensation formed at the top\u00a0of\u00a0the\u00a0test-tube dilute nitric acid and aqueous silver nitrate were  added to an aqueous solution of solid q.white precipitate  (e)  what conclusions can you draw about the identity of solid q?      ..   [2]  [total: 8]",
            "9": "9 0620/63/o/n/18 \u00a9 ucles 2018 [turn over 4  some cleaning products are mixtures. the three substances present in a cleaning product are  listed in the table. substancestate at room temperaturephysical property sodium carbonate solid melts\u00a0at\u00a0858\u00a0 \u00b0c ethanol liquid boils at 78 \u00b0c limonene liquid boils at 176 \u00b0c   use the information in the table to plan an experiment to obtain a sample of each substance from a mixture of the three substances.   you are provided with a mixture of the three substances and common laboratory apparatus.     ...   ...   ...   ...   ...   ...   ...   .   [6]  [total: 6]",
            "10": "10 0620/63/o/n/18 \u00a9 ucles 2018blank page",
            "11": "11 0620/63/o/n/18 \u00a9 ucles 2018blank page",
            "12": "12 0620/63/o/n/18 \u00a9 ucles 2018blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every reasonable  effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge international  examinations copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. cambridge international examinations is part of the cambridge assessment group. cambridge assessment is the brand name of university of cambridge local  examinations syndicate (ucles), which is itself a department of the university of cambridge."
        }
    },
    "2019": {
        "0620_m19_qp_12.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level1/level 2 certifica te.  this document consists of 15 printed pages and 1 blank page.  ib19 03_0620_12/4rp  \u00a9 ucles 2019   [turn over     *3869787358 * cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1  multiple choice (core)  february/march 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.    ",
            "2": "2  \u00a9 ucles 2019 0620/12/f/m/19  1 four processes are listed.    1 brownian motion  2 condensation  3 diffusion  4 evaporation    which processes involve a change of state?  a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      2 a student measures the time taken for 2.0  g of magnesium to dissolve in 50  cm3 of dilute  sulfuric acid.    which apparatus is essential to complete the experiment?    1 stop-clock  2 measuring cylinder  3 thermometer 4 balance    a 1, 2 and 4 b 1 and 2 only c 1 and 4 only d 2, 3 and 4      3 which method should be used to separate a mixture of two liquids?  a crystallisation  b electrolysis  c filtration  d fractional distillation     ",
            "3": "3  \u00a9 ucles 2019 0620/12/f/m/19 [turn over  4 lead( ii) iodide is insoluble in water.    lead( ii) iodide is made by adding aqueous lead( ii) nitrate to aqueous potassium iodide.    which pieces of apparatus are needed to obtain solid lead( ii) iodide from 20  cm3 of aqueous  lead( ii) nitrate?    12345    a 1, 2 and 4 b 1, 3 and 5 c 1, 4 and 5 d 2, 4 and 5     5 which row describes isotopes of the same element?     number of protons number of neutrons  a different different  b different same  c same different  d same same    6 which row describes the structure of the positive ion in sodium chloride?     protons electrons neutrons  a 11 11 12  b 11 10 12  c 17 17 18  d 17 18 18    ",
            "4": "4  \u00a9 ucles 2019 0620/12/f/m/19  7 which pair of statements about diamond and graphite is correct?    diamond graphite    a diamond and graphite are both pure carbon. they are both macromolecules.  b diamond and graphite can both be used as electrodes. graphite is also used as a lubricant.  c diamond has covalent bonds. graphite has ionic bonds.  d diamond is hard with a high melting point. graphite is soft with a low melting point.      8 what is the nucleon number of an atom?  a the number of neutrons  b the number of protons  c the total number of protons and neutrons  d the total number of protons and electrons      9 the relative formula mass, mr, of calcium carbonate, caco 3, is 100.    what is the mass of carbon present in 100  g of calcium carbonate?  a 12  g b 36  g c 40  g d 60  g    ",
            "5": "5  \u00a9 ucles 2019 0620/12/f/m/19 [turn over  10 two electrolysis experiments were carried out as shown.    the graphite electrodes are labelled 1\u2013  4.    power supply molten  sodium chloride12 34 concentrated aqueous sodium chloride++ \u2013\u2013power supply     which row describes the products at the electrodes in these experiments?     electrode 1 electrode 2 electrode 3 electrode 4  a chlorine hydrogen chlorine hydrogen  b chlorine sodium chlorine hydrogen  c chlorine sodium hydrogen chlorine  d sodium chlorine sodium chlorine      11 10  g of ammonium nitrate is added to water at 25  \u00b0c and the mixture stirred.    the ammonium nitrate dissolves and, after one minute, the temperature of the solution is 10  \u00b0c.    which word describes this change?  a endothermic  b exothermic  c neutralisation  d reduction      12 which process involves a chemical change?  a dissolving copper( ii) sulfate  b distilling ethanol  c freezing water  d neutralising copper( ii) oxide     ",
            "6": "6  \u00a9 ucles 2019 0620/12/f/m/19  13 lumps of limestone react with dilute hydrochloric acid according to the equation shown.    caco 3  +  2hc l  \u2192  cac l 2  +  h 2o  +  co 2    which change in conditions decreases the rate of the reaction?  a increase the concentration of the acid  b increase the volume of the acid  c increase the size of the lumps of limestone  d increase the temperature    14 which reaction is reversible?  a cu  +  znso 4  \u2192  cuso 4  +  zn  b cuo  +  h 2so 4  \u2192  cuso 4  +  h 2o  c cuo  +  h 2  \u2192  cu  +  h 2o  d cuso 4\u20225h 2o  \u2192  cuso 4  +  5h 2o    15 the reaction between magnesium and carbon dioxide is shown in the equation.    2mg  +  co 2  \u2192  2mgo  +  c    which statement describes what happens in this reaction?  a carbon is oxidised.  b magnesium is reduced.  c neither oxidation nor reduction happens.  d the carbon in carbon dioxide is reduced.    16 barium hydroxide is an alkali. it reacts with hydrochloric acid.    how does the ph of the hydrochloric acid change as an excess of aqueous barium hydroxide is  added?  a the ph decreases from ph  14 and becomes constant at ph  7.  b the ph decreases from ph  14 to about ph  1.  c the ph increases from ph  1 and becomes constant at ph  7.  d the ph increases from ph  1 to about ph  14.     ",
            "7": "7  \u00a9 ucles 2019 0620/12/f/m/19 [turn over  17 copper( ii) sulfate crystals are blue. they are made by adding an excess of copper( ii) oxide to  sulfuric acid.    the mixture is heated and stirred.    it is then filtered and the filtrate is allowed to evaporate, leaving blue crystals.    why is filtration necessary?  a to remove soluble properties  b to remove sulfuric acid  c to remove the blue crystals  d to remove unreacted copper( ii) oxide      18 the results of two tests on an aqueous solution of x are shown.    test observation  aqueous sodium hydroxide added green precipitate formed  acidified aqueous silver nitrate added yellow precipitate formed    what is x?  a copper( ii) chloride  b copper( ii) iodide  c iron(ii) chloride  d iron(ii) iodide      19 information about the solubility in water of four oxides is shown.    which oxide, when added to water, gives a solution with a ph less than ph  7?     name of oxide solubility in water  a nitrogen dioxide soluble  b copper( ii) oxide insoluble  c silicon( iv) oxide insoluble  d barium oxide soluble     ",
            "8": "8  \u00a9 ucles 2019 0620/12/f/m/19  20 the elements sodium to argon form period 3 of the periodic table.    which row describes the trend across period 3 from left to right?     number of outer  shell electrons metallic  character group number  a decreases decreases decreases  b decreases increases decreases  c increases decreases increases  d increases increases increases     21 astatine is below iodine in group vii in the periodic table.    which row describes the properties of astatine?     state at room  temperature  reactivity   a gas displaces chlorine, bromine and iodine   b gas displaces iodine but does not displace chlorine or bromine   c solid displaces iodine but does not displace chlorine or bromine   d solid does not displace chlorine, bromine or iodine       22 which row describes a transition element?     density  in g  / cm3 colour of  chloride  a 0.98 green  b 0.98 white  c 8.90 green  d 8.90 white      23 which statement explains why elements in group viii of the periodic table are unreactive?  a they are monatomic gases.  b they form stable diatomic molecules.  c they have a full outer shell of electrons.  d they share electrons with each other.     ",
            "9": "9  \u00a9 ucles 2019 0620/12/f/m/19 [turn over  24 the electrical conductivity of magnesium was tested.    magnesium was then added to dilute sulfuric acid and a gas, q, was produced.    which row is correct?     electrical conductivity  of magnesium gas q  a good hydrogen  b good oxygen  c poor hydrogen  d poor oxygen      25 four reactions that take place in the blast furnace to produce iron are shown.    which reaction is used to keep the furnace hot?  a c  +  o 2  \u2192  co 2  b co 2  +  c  \u2192  2co  c fe 2o3  +  3c  \u2192  2fe  +  3co  d fe 2o3  +  3co  \u2192  2fe  +  3co 2      26 the list gives the order of some metals and hydrogen in the reactivity series.    metal x is also included.    most reactive k   mg  zn  h  x least reactive cu    which row correctly shows the properties of metal x?     reacts with  dilute acids oxide reduced  by carbon  a no no  b no yes  c yes no  d yes yes   ",
            "10": "10  \u00a9 ucles 2019 0620/12/f/m/19  27 the properties of four elements are shown.    which element is used to make aircraft bodies?     density brittle or  malleable  a high brittle  b high malleable  c low brittle  d low malleable      28 the diagram shows how water is treated to make it suitable for drinking.    reservoir of waterstage 1 stage 2 chlorinationstage 3 drinking waterstage 4     what happens in stage 2?  a condensation  b sublimation  c evaporation  d filtration    29 a farmer treats a field with calcium hydroxide to make it less acidic.    when the farmer adds ammonium nitrate fertiliser to the field immediately after the  calcium hydroxide, they react.    why does this reaction make the fertiliser less effective?  a it makes ammonia gas, so less nitrogen is absorbed by the soil.  b it makes an acid, making the soil acidic again.  c it makes nitrogen gas, so less nitrogen is absorbed by the soil.  d it makes the fertiliser too strong, stopping the plants growing so well.     ",
            "11": "11  \u00a9 ucles 2019 0620/12/f/m/19 [turn over  30 which row showing an air pollutant and its major source is not correct?     pollutant major source of pollutant  a carbon monoxide complete combustion of carbon fuels  b lead compounds leaded petrol  c oxides of nitrogen car engines  d sulfur dioxide fossil fuels containing sulfur      31 which substances are needed for iron to rust?  a carbon dioxide and oxygen  b oxygen only  c water and carbon dioxide  d water and oxygen      32 methane and carbon dioxide are both greenhouse gases.    which row identifies a source of methane and a source of carbon dioxide?     source of methane source of carbon dioxide  a decomposition of vegetation hydrogen car exhausts  b digestion in animals diesel car exhausts  c petrol car exhausts decomposition of vegetation  d respiration petrol car exhausts      33 which element has an oxide that is used as a food preservative?  a helium  b hydrogen  c iron  d sulfur     ",
            "12": "12  \u00a9 ucles 2019 0620/12/f/m/19  34 lime is made by heating limestone.    which equation represents this reaction?  a caco 3  \u2192  ca  +  o 2  +  co  b caco 3  \u2192  cao  +  co 2  c caco 3  +  h 2o  \u2192  cao  +  h 2co 3  d caco 3  +  h 2o  \u2192  ca(oh) 2  +  co 2     35 most objects made from synthetic polymers last for many years.    why do these polymers last for so long?     chemically  unreactive biodegradable  a no no  b no yes  c yes no  d yes yes     36 the structure of a compound, g, is shown.    g is in the same homologous series as ethanoic acid.    hch hch hco o h     which row describes some of the properties of an aqueous solution of g?     produces a gas  with magnesium turns methyl orange  yellow  a no yes  b no no  c yes no  d yes yes     ",
            "13": "13  \u00a9 ucles 2019 0620/12/f/m/19 [turn over  37 the fractional distillation of petroleum is shown.    paraffin fractiongasoline fractionrefinery gas diesel oil lubricating fractionpetroleum bitumen    which fraction is the least volatile?  a bitumen  b diesel oil  c gasoline fraction  d refinery gas     38 which row shows the properties of methane?     soluble  in water state at room  temperature gives a positive test  with aqueous bromine  a no gas no  b no gas yes  c yes liquid no  d yes liquid yes     ",
            "14": "14  \u00a9 ucles 2019 0620/12/f/m/19  39 the formulae of five compounds are listed.    1 c 4h10  2 c 2h5oh  3 c 4h9oh  4 c 4h9cooh  5 c 5h11oh    which compounds are in the same homologous series?  a 1, 3 and 4 only  b 2, 3 and 5 only  c 3 and 4 only  d 3 and 5 only     40 which process is used to make an alkene from a long-chain alkane?  a combustion  b condensation  c cracking  d polymerisation    ",
            "15": "15    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/12/f/m/19 ",
            "16": "16  \u00a9 ucles 2019 0620/12/f/m/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m19_qp_22.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certific ate.  this document consists of 15 printed pages and 1 blank page.  ib19 03_0620_22/4rp  \u00a9 ucles 2019   [turn over     *8959971806* cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2  multiple choice (extended)  february/march 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number  on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.    ",
            "2": "2  \u00a9 ucles 2019 0620/22/f/m/19  1 pure water boils at 100  \u00b0c.    what happens to the water particles when water boils?  a they gain energy and move further apart.  b they gain energy and stay close together.  c they lose energy and move further apart.  d they lose energy and stay close together.      2 which method should be used to separate a mixture of two liquids?  a crystallisation  b electrolysis  c filtration  d fractional distillation      3 lead( ii) iodide is insoluble in water.    lead( ii) iodide is made by adding aqueous lead( ii) nitrate to aqueous potassium iodide.    which pieces of apparatus are needed to obtain solid lead( ii) iodide from 20  cm3 of aqueous  lead( ii) nitrate?    12345    a 1, 2 and 4 b 1, 3 and 5 c 1, 4 and 5 d 2, 4 and 5     ",
            "3": "3  \u00a9 ucles 2019 0620/22/f/m/19 [turn over  4 the chromatogram of substance s is shown.    some distances, w, x, y and z, are labelled on the diagram.    solvent levelbaselinesubstance ssolvent front w x y z     how is the rf value of substance s calculated?  a yx b zw c xy d wy      5 which row describes isotopes of the same element?     number of protons number of neutrons  a different different  b different same  c same different  d same same      6 which row describes the structure of the positive ion in sodium chloride?     protons electrons neutrons  a 11 11 12  b 11 10 12  c 17 17 18  d 17 18 18     ",
            "4": "4  \u00a9 ucles 2019 0620/22/f/m/19  7 which statement about copper, diamond and silicon( iv) oxide is correct?  a copper and silicon( iv) oxide have similar electrical conductivity.  b in diamond the carbon atoms are covalently bonded as flat sheets.  c in silicon( iv) oxide the silicon and oxygen atoms are covalently bonded as flat sheets.  d the structure of copper includes a lattice of positive ions.    8 an oxide of nitrogen has the following composition by mass: n, 30.4%; o, 69.6%.    it has a relative molecular mass of 92.    what is the molecular formula of the oxide of nitrogen?  a no b no 2 c no 4 d n2o4    9 calcium carbonate reacts with dilute hydrochloric acid according to the equation shown.    caco 3  +  2hc l  \u2192  cac l 2  +  co 2  +  h 2o    10  g of calcium carbonate is reacted with 100  cm3 of 1  mol  / dm3 hydrochloric acid.    the following statements are made.    1 1.2  dm3 of carbon dioxide is formed.  2 5.6  g of calcium chloride is formed.  3 4.8  g of carbon dioxide is formed.  4 no calcium carbonate is left when the reaction is completed.    which statements about the reaction are correct?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    10 which substance is not produced during the electrolysis of concentrated aqueous  sodium chloride?  a chlorine  b hydrogen  c sodium  d sodium hydroxide    ",
            "5": "5  \u00a9 ucles 2019 0620/22/f/m/19 [turn over  11 aqueous copper( ii) sulfate is electrolysed using copper electrodes.    what are the ionic half-equations for the reactions that occur at each electrode?     anode cathode  a cu  \u2192  cu2+  +  2e\u2013 cu2+  +  2e\u2013  \u2192  cu  b cu2+  +  2e\u2013  \u2192  cu cu  \u2192  cu2+  +  2e\u2013  c 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013 cu2+  +  2e\u2013  \u2192  cu  d 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013 2h+  +  2e\u2013  \u2192  h2      12 10  g of ammonium nitrate is added to water at 25  \u00b0c and the mixture stirred.    the ammonium nitrate dissolves and, after one minute, the temperature of the solution is 10  \u00b0c.    which word describes this change?  a endothermic  b exothermic  c neutralisation  d reduction    13 hydrogen reacts with chlorine according to the following equation.    h 2(g)  +  c l 2(g)  \u2192  2hc l (g)    the reaction is exothermic.    which statement about this reaction is correct?  a energy absorbed for bond breaking is greater than the energy released in bond making.  b energy absorbed for bond breaking is less than the energy released in bond making.  c energy released in bond breaking is greater than the energy absorbed in bond making.  d energy released in bond breaking is less than the energy absorbed in bond making.    ",
            "6": "6  \u00a9 ucles 2019 0620/22/f/m/19  14 hydrogen-oxygen fuel cells can be used to power cars. platinum is used as a catalyst.    the amount of energy produced per gram is shown for three fuels.    fuel energy produced  per g of fuel  / kj  hydrogen 143  methane 55  petrol 44    which statement is correct and is an advantage of a hydrogen-oxygen fuel cell?  a hydrogen is difficult to store.  b hydrogen produces less energy per gram than methane or petrol.  c platinum is rare and expensive.  d the only product is water.     15 a student adds dilute hydrochloric acid at two different temperatures to two different lumps of  limestone. the lumps of limestone have the same mass.    the carbon dioxide gas produced is collected in a gas syringe.    the volume of carbon dioxide collected in 1 minute at each temperature is shown.    temperature  / \u00b0c volume of carbon dioxide  produced in 1 minute  / cm3  25 10  50 40    which row describes and explains the results obtained at 50  \u00b0c compared with 25  \u00b0c?     reaction rate energy of collisions  a higher lower  b higher higher  c lower lower  d lower higher     ",
            "7": "7  \u00a9 ucles 2019 0620/22/f/m/19 [turn over  16 which reaction is reversible?  a cu  +  znso 4  \u2192  cuso 4  +  zn  b cuo  +  h 2so 4  \u2192  cuso 4  +  h 2o  c cuo  +  h 2  \u2192  cu  +  h 2o  d cuso 4\u20225h 2o  \u2192  cuso 4  +  5h 2o     17 some nitrogen dioxide gas was put in a gas syringe. the end of the gas syringe is sealed.    a reversible reaction occurs. the reaction reaches equilibrium.    2no 2(g)          n 2o4(g)   dark brown light yellow    the forward reaction is exothermic.    which statement about the reaction is correct?  a if the gas syringe is placed in a cold water bath, the colour becomes darker.  b if the gas syringe is placed in a hot water bath, the colour becomes lighter.  c if the volume in the gas syringe is increased, the colour becomes lighter.  d if the volume in the gas syringe is decreased, the colour becomes lighter.    18 the reaction between magnesium and carbon dioxide is shown in the equation.    2mg  +  co 2  \u2192  2mgo  +  c    which statement describes what happens in this reaction?  a carbon is oxidised.  b magnesium is reduced.  c neither oxidation nor reduction happens.  d the carbon in carbon dioxide is reduced.    19 which changes involve reduction?    1 2 i \u2013  \u2192  i2  +  2e\u2013  2 cuo  +  h 2  \u2192  cu  +  h 2o  3 a l 3+  +  3e\u2013  \u2192  a l  4 pb2+  +  so 42\u2013  \u2192  pbso 4    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    ",
            "8": "8  \u00a9 ucles 2019 0620/22/f/m/19  20 barium hydroxide is an alkali. it reacts with hydrochloric acid.    how does the ph of the hydrochloric acid change as an excess of aqueous barium hydroxide is  added?  a the ph decreases from ph  14 and becomes constant at ph  7.  b the ph decreases from ph  14 to about ph  1.  c the ph increases from ph  1 and becomes constant at ph  7.  d the ph increases from ph  1 to about ph  14.     21 which statement describes a chemical property of aluminium oxide, a l  2o3?  a it reacts with acids but not with bases.  b it reacts with acids and bases.  c it reacts with bases but not with acids.  d it reacts with water.     22 the results of two tests on an aqueous solution of x are shown.    test observation  aqueous sodium hydroxide added green precipitate formed  acidified aqueous silver nitrate added yellow precipitate formed    what is x?  a copper( ii) chloride  b copper( ii) iodide  c iron(ii) chloride  d iron(ii) iodide     ",
            "9": "9  \u00a9 ucles 2019 0620/22/f/m/19 [turn over  23 four stages used to prepare an insoluble salt are listed.    1 drying  2 filtration  3 precipitation  4 washing    in which order are the stages done?  a 2 \u2192 1 \u2192 3 \u2192 4  b 3 \u2192 2 \u2192 4 \u2192 1  c 3 \u2192 4 \u2192 1 \u2192 2  d 4 \u2192 3 \u2192 2 \u2192 1     24 the elements sodium to argon form period 3 of the periodic table.    which row describes the trend across period 3 from left to right?     number of outer  shell electrons metallic  character group number  a decreases decreases decreases  b decreases increases decreases  c increases decreases increases  d increases increases increases     25 astatine is below iodine in group vii in the periodic table.    which row describes the properties of astatine?     state at room  temperature  reactivity   a gas displaces chlorine, bromine and iodine   b gas displaces iodine but does not displace chlorine or bromine   c solid displaces iodine but does not displace chlorine or bromine   d solid does not displace chlorine, bromine or iodine      ",
            "10": "10  \u00a9 ucles 2019 0620/22/f/m/19  26 which statement explains why elements in group viii of the periodic table are unreactive?  a they are monatomic gases.  b they form stable diatomic molecules.  c they have a full outer shell of electrons.  d they share electrons with each other.      27 in which reaction does fe(s) form ions when the mixture is heated?  a fe(s)  +  cao(s)  b fe(s)  +  mgo(s)  c fe(s)  +  zno(s)  d fe(s)  +  cuo(s)      28 the list gives the order of some metals and hydrogen in the reactivity series.    metal x is also included.    most reactive k   mg   zn  h  x least reactive cu    which row correctly shows the properties of metal x?     reacts with  dilute acids oxide reduced  by carbon  a no no  b no yes  c yes no  d yes yes     ",
            "11": "11  \u00a9 ucles 2019 0620/22/f/m/19 [turn over  29 which metal carbonate does not produce carbon dioxide when it is heated?  a copper( ii) carbonate  b iron( ii) carbonate  c potassium carbonate  d zinc carbonate     30 which statement about the extraction of metals is correct?  a aluminium is extracted by the electrolysis of hematite.  b cryolite acts as a reducing agent in the extraction of aluminium.  c zinc is extracted by the electrolysis of zinc blende.  d zinc is obtained by heating zinc oxide with coke.    31 the diagram shows how water is treated to make it suitable for drinking.    reservoir of waterstage 1 stage 2 chlorinationstage 3 drinking waterstage 4     what happens in stage 2?  a condensation  b sublimation  c evaporation  d filtration      32 what are the main substances produced by the fractional distillation of liquid air?  a oxygen and carbon dioxide  b oxygen and nitrogen  c helium and nitrogen  d hydrogen and oxygen     ",
            "12": "12  \u00a9 ucles 2019 0620/22/f/m/19  33 the raw materials for the haber process are hydrogen and nitrogen.    what are the sources of the hydrogen and nitrogen?  a hydrogen from ethanol and nitrogen from npk fertilisers  b hydrogen from methane and nitrogen from air  c hydrogen from sulfuric acid and nitrogen from air  d hydrogen from water and nitrogen from ammonium nitrate     34 which process removes carbon dioxide from the earth\u2019s atmosphere?  a combustion  b heating limestone  c photosynthesis  d respiration    35 the contact process is used to make sulfuric acid.    the steps in the process are listed.    1 dissolve sulfur trioxide in 98% concentrated sulfuric acid.  2 heat sulfur strongly in air. 3 add oleum to water.  4 pass sulfur dioxide over a vanadium( v) oxide catalyst.    which sequence of steps is correct?  a 4 \u2192 1 \u2192 2 \u2192 3  b 4 \u2192 2 \u2192 3 \u2192 1  c 2 \u2192 1 \u2192 4 \u2192 3  d 2 \u2192 4 \u2192 1 \u2192 3    ",
            "13": "13  \u00a9 ucles 2019 0620/22/f/m/19 [turn over  36 the fractional distillation of petroleum is shown.    paraffin fractiongasoline fractionrefinery gas diesel oil lubricating fractionpetroleum bitumen    which fraction is the least volatile?  a bitumen  b diesel oil  c gasoline fraction  d refinery gas      37 which statement about members of a homologous series is correct?  a successive members differ by ch 3.  b successive members have a molecular mass that differs by 14.  c they have the same molecular formula.  d they have identical physical properties.     38 ethanol is manufactured on a large scale by fermentation.    which statement about fermentation is correct?  a it is a continuous process.  b a renewable raw material is used.  c it is a very fast reaction.  d the ethanol produced is pure.    ",
            "14": "14  \u00a9 ucles 2019 0620/22/f/m/19  39 the structure of a compound, g, is shown.    g is in the same homologous series as ethanoic acid.    hch hch hco o h     which row describes some of the properties of an aqueous solution of g?     produces a gas  with magnesium turns methyl orange  yellow  a no yes  b no no  c yes no  d yes yes      40 which statement about polymers is correct?  a nylon contains the                        linkage.  b nylon is a polyester.  c propane can be polymerised by addition polymerisation.  d the linkage in terylene  contains a carbon-carbon double bond.     co n h",
            "15": "15    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/22/f/m/19  ",
            "16": "16  \u00a9 ucles 2019 0620/22/f/m/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m19_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32 paper 3  theory (core) february/march 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib19 03_0620_32/4rp\u00a9 ucles 2019 *9386818547* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/f/m/19 \u00a9 ucles 2019 1  this question is about electronic structures.  (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td and e,\tare\tshown. a bc d e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\telectronic\tstructures. \t\teach\telectronic\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\tstate\twhich\telectronic\tstructure,\t a,\tb,\tc,\td or e,\trepresents\tan\tatom:  (i)\t\tof\tan\telement\tin\tgroup\tiii\tof\tthe\tperiodic\t table\t    [1]  (ii)\t\tof\ta\tmonatomic\tgas\t ..   [1]  (iii)  of carbon  ...   [1]  (iv)\t\twhich\thas\t18\tprotons\t    [1]  (v)\t\twhich\tforms\ta\tstable\tion\twith\ta\tsingle\tnegative\tcharge.\t ...   [1]  (b)\t draw\tthe\telectronic\tstructure\tof\ta\tsilicon\tatom.  [2] \t [total:\t7]",
            "3": "3 0620/32/f/m/19 \u00a9 ucles 2019 [turn over 2\t\tthis\tquestion\tis\tabout\turanium\tand\tits\tcompounds.  (a) (i)\t\tan\tisotope\tof\turanium\tis\trepresented\tby \tthe\tsymbol\tshown. 235u92 \t \tdeduce\tthe\tnumber\tof\telectrons\tand\tneutrons\tin\tone\tatom\tof\tthis\tisotope\tof\turanium. \t \tnumber\tof\telectrons\t   \t \tnumber\tof\tneutrons\t    [2]  (ii)\t\tstate\tthe\tmain\tuse\tof\tthis\tisotope\tof\turanium.   ...   [1]  (b)\t\tcomplete\tthe\tsentence\tabout\tisotopes\tusing\twords \tfrom\tthe\tlist. atoms          compound          electrons          element          ions mixture          molecules          neutrons          substance \t\tisotopes\tare\t.\t of\tthe\tsame\t.\t which\thave\tthe\tsame    proton\tnumber\tbut\ta\tdifferent\tnumber\tof\t.\t.  [3]  (c)\t\turanium\tis\ta\tmetal. \t\tgive\ttwo\tphysical\tproperties\twhich\tare\tcharacteristic\tof\t all\tmetals.  1  .  2  .  [2]  (d)\t\turanium\treacts\twith\thydrogen\tto\tform\turanium\thydride,\tuh3. \t\tthe\treaction\tis\treversible. \t\tcomplete\tthe\tchemical\tequation\tfor\tthis\treaction\tby:  \u25cf\tbalancing\tthe\tequation  \u25cf\tdrawing\tthe\tsymbol\tfor\ta\treversible\treaction\tin\tthe\tbox. 2u\t\t+\t\t.\th2  \t\t\u2026.\tuh3  [3]",
            "4": "4 0620/32/f/m/19 \u00a9 ucles 2019  (e)\t\ta\tcompound\tof\turanium\thas\tthe\tformula\tuo2f2. \t\tcomplete\tthe\ttable\tto\tcalculate\tthe\trelative\tformula\tmass\tof\tuo2f2. \t\tuse\tyour\tperiodic\t table\tto\thelp\tyou. number\tof\tatoms relative\tatomic\tmass uranium 1 238 1 \u00d7\t238\t=\t238 oxygen fluorine \t relative\tformula\tmass\t=\t..  [2] \t [total:\t13]",
            "5": "5 0620/32/f/m/19 \u00a9 ucles 2019 [turn over 3\t\tthis\tquestion\tis\tabout\tsulfur,\tsulfur\tcompounds\t and\tthe\twater\tfrom\ta\tsulfur\tspring.\ta\tsulfur\tspring\t is\ta\tnatural\tsource\tof\twater\tcontaining\tsulfur.  (a)\t\tthe\ttable\tshows\tthe\tmass\tof\tions\tpresent\tin\ta\t1000 \tcm3\tsample\tof\twater\tfrom\ta\tsulfur\tspring. ion\tpresent formula\tof\tionmass\tpresent\tin\tthe 1000\tcm3\tsample\t/\tmg br \u20134 calcium ca2+44 chloride cl \u201314 fluoride f \u20136 iron(iii) fe3+2 magnesium mg2+10 k+8 sodium na+88 sulfate so42\u201392 \t\tanswer\tthese\tquestions\tusing\tonly\tinformation\tfrom\tthe\ttable.  (i)\t\twhich\tnegative\tion\tis\tpresent\tin\tthe\tlowest\tconcentration?   ...   [1]  (ii)\t\tgive\tthe\tname\tof\tthe\tcompound\tformed \tfrom\tonly\tk+ and br \u2013 ions.   ...   [1]  (iii)\t\tcalculate\tthe\tmass\tof\tcalcium\tions\tpresent\tin\ta\t250\t cm3\tsample\tof\tthis\twater. \t mass\tof\tcalcium\tions\t=\t..\tmg\t\t[1]  (iv)\t\tcomplete\tthe\tequation\tto\tshow\tthe\tformation\tof\ta\tfluoride\tion\tfrom\ta\tfluorine\tatom. f  +  ...    f \u2013  [1]  (b)  describe a test for sulfate ions.  test  . \t observations\t  ..  [2]",
            "6": "6 0620/32/f/m/19 \u00a9 ucles 2019  (c)\t\tsolid\tsulfur\tis\tfound\taround\tthe\tedge\tof\tsulfur\tsprings.  (i)\t\twhen\theated,\tsulfur\tundergoes\tsublimation. \t \twhat\tis\tmeant\tby\tthe\tterm\tsublimation ?   .   ...   [1]  (ii)\t\tsulfur\treacts\twith\thot\tconcentrated\tsulfuric\tacid. \t \tcomplete\tthe\tchemical\tequation\tfor\tthis \treaction. \t s\t\t+\t\t.\th2so4  \t\t2h2o\t\t+\t\t.\tso2 [2]  (iii)\t\tthe\ttable\tshows\tthe\tsolubility\tof\tsulfur\tand\tzinc\tin\tan\torganic\tsolvent\tand\tin\twater.\tthe\t organic\tsolvent\tboils\tat\t46\t \u00b0c. elementsolubility\tin organic\tsolventsolubility\tin\twater sulfur soluble insoluble zinc insoluble insoluble \t \tuse\tthe\tinformation\t in\tthe\ttable\tto\tsuggest\thow\tto\tobtain\tpure,\tdry\tsamples\tof\tboth\tsulfur\t and\tzinc\tfrom\ta\tmixture\tof\tsulfur\tpowder\tand\tzinc\tpowder.   .   .   .   .   .   ...   [4]  (d)\t\tthe\tstructure\tof\ta\tsulfur\tcompound\tis\tshown. sf ff fo ff \t\tdeduce\tthe\tmolecular\t formula\tof\tthis\tcompound\t showing\tthe\tnumber\tof\tsulfur,\tfluorine\tand\t oxygen\tatoms.   ..   [1]  [to tal:\t14]",
            "7": "7 0620/32/f/m/19 \u00a9 ucles 2019 [turn over 4\t\ta\tstudent\tinvestigated \tthe\treaction\tbetween\tzinc\tand\tdilute\thydrochloric\t acid\tby\tmeasuring\t the\t volume\tof\thydrogen\tgas\tproduced\tat\tone\tminute\tintervals. zn\t\t+\t\t2hcl    zncl 2\t\t+\t\th2  (a)\t\tgive\tthe\tname\tof\tthe\tsalt\tformed\tin\tthis\treaction.   ..   [1]  (b)\t\tthe\tgraph\tshows\tthe\tresults\tusing\tsmall\tpieces\tof\tzinc\tand\tdilute\thydrochloric\tacid. 100 80 60 40 20 0 012345volume of hydrogen gas / cm3 time  / minutes  (i)\t\tdeduce\tthe \tvolume\tof\thydrogen\tgas\tproduced\tin\tthe\tfirst\ttwo\tminutes\tof\tthe\treaction. \t ..\tcm3  [1]  (ii)\t\tdraw\ta\tletter\t s on the graph\t to\tshow\twhere\tthe\treaction\tis\tslowing\tdown\tbut\thas\tnot  stopped\tcompletely.\t [1]  (iii)\t\tdraw\ta\tline\ton the grid\t to\tshow\thow\tthe\tvolume\tof\thydrogen\t gas\tchanges\twith\ttime\twhen\t the\treaction\tis\trepeated\twith\ta\tcatalyst. \t \tall\tother\tconditions\tare\tkept\tthe\tsame.\t [2]",
            "8": "8 0620/32/f/m/19 \u00a9 ucles 2019  (iv)\t\twhat\teffect\tdo\tthe\tfollowing\thave\ton\tthe \trate\tof\tthis\treaction? \t \u25cf\t\tdecreasing\tthe\ttemperature\tat\twhich\tthe\treaction\tis\tdone. \t \tall\tother\tconditions\tare\tkept\tthe\tsame.   . \t \u25cf\t\tusing\tzinc\tpowder\tinstead\tof\tsmall\tpieces\tof\tzinc. \t \tall\tother\tconditions\tare\tkept\tthe\tsame.   .  [2]  (c)\t\tdescribe\ta\ttest\tfor\thydrogen.  test  .  result  ..  [2]  (d)\t\tthe\ttable\tgives\tsome\tinformation\t about\tthe\trate\tof\treaction\tof\tzinc\tand\tsome\tother\tmetals\twith\t cold\twater\tand\twith\tsteam. metalrate of reaction with\tcold\twater with\tsteam iron no reaction hot\tiron\treacts\tvery\tslowly magnesium reacts\tvery\tslowly hot\tmagnesium\treacts\trapidly mercury no reaction no reaction strontium reacts\trapidly reacts\trapidly zinc no reaction hot\tzinc\treacts\tslowly \t\tput\tthe\tfive\tmetals\tin\torder\tof\ttheir\treactivity. \t\tput\tthe\tmost\treactive\tmetal\tat\tthe\ttop. most\treactive least\treactive  [2] ",
            "9": "9 0620/32/f/m/19 \u00a9 ucles 2019 [turn over  (e)\t\twhen\t13.0\t g\tof\tzinc\treacts\tcompletely\twith\tsulfur,\t19.4\t g\tof\tzinc\tsulfide\tis\tformed. \t\tcalculate\t the\tmaximum\t mass\tof\tzinc\tsulfide\tformed\twhen\t3.25\tg\tof\tzinc\treacts\tcompletely\t with\t sulfur. \t mass\tof\tzinc\tsulfide\tformed\t=\t..\tg\t\t[1] \t [total:\t12]",
            "10": "10 0620/32/f/m/19 \u00a9 ucles 2019 5\t\taqueous\tsodium\thydroxide\tis\ta\tbase.  (a)\t\tdescribe\tthe\treaction\tof\taqueous\tsodium\thydroxide \twith:  \u25cf\ta\tnamed\tacid           \u25cf\tammonium\tsalts           \u25cf\ta\tnamed\tindicator.          \t [5]  (b)\t\tammonia\tis\ta\tsoluble\tbase.   which one\tof\tthe\tfollowing\tph\tvalues\tcould\tbe\tthe\tph\tof\taqueous\tammonia? \t\tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. \t ph\t1\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t5\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t7\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tph\t10\t [1]  (c)\t\tammonia\tis\tused\tin\tthe\tmanufacture\tof\tsome\tfertilisers.   which two\tof\tthese\tcompounds\tare\tpresent\tin\tfertilisers?   tick two\tboxes. \t copper( ii)\toxide \t \tpotassium\tchloride \t sodium\tphosphate \t strontium\tfluoride \t sulfur\tdioxide  [2]",
            "11": "11 0620/32/f/m/19 \u00a9 ucles 2019 [turn over  (d)\t\tbacteria\tin\tthe\tsoil\tare\table\tto\tconvert\tammonium\tcompounds\tinto\toxides\tof\tnitrogen. \t\tthe\toxides\tof\tnitrogen\tcan\tescape\tinto\tthe\tatmosphere.  (i)  state one\tother\tsource\tof\toxides\tof\tnitrogen\tin\tthe\tatmosphere.   ...   [1]  (ii)  state one\teffect\tof\toxides\tof\tnitrogen\ton \thealth.   ...   [1]  (iii)\t\toxides\tof\tnitrogen\tare\tgreenhouse\tgases\twhich\tcontribute\tto\tclimate\tchange. \t \tgive\tthe\tname\tof\tone\tother\tgreenhouse \tgas\twhich\tmakes\ta\tmajor\tcontribution\t to\tclimate\t change.   ...   [1] \t [total:\t11]",
            "12": "12 0620/32/f/m/19 \u00a9 ucles 2019 6\t\tthis\tquestion\tis\tabout\tchromium\tand\tchromium\tcompounds.  (a) (i)\t\tsuggest\twhy\tchromium \tis\tmanufactured\t by\telectrolysis\t and\t not\tby\tthe\treduction\t of\t chromium( vi)\toxide,\tcro3,\twith\tcarbon.   ...   [1]  (ii)\t\tsuggest\tthe\tproducts\tof\telectrolysis\tof\tmolten\tchromium( vi)\toxide\tat: \t \u25cf\t\tthe\tpositive\telectrode\t  ... \t \u25cf\t\tthe\tnegative\telectrode.\t    [2]  (b)\t\tchromium\t can\talso\tbe\tmanufactured\t by\tthe\treduction\t of\tchromium( iii)\toxide,\tcr2o3,\twith\t aluminium. cr2o3  +  2a l    al 2o3  +  2cr  (i)\t\thow\tdoes\tthis\tequation\tshow\tthat\tchromium( iii)\toxide\tis\treduced?   .   ...   [1]  (ii)\t\tthe\tenergy \tlevel\tdiagram\tfor\tthis\treaction\tis\tshown. energy progress of reactioncr2o3  +  2a l al 2o3  +  2cr \t \texplain\thow\tthis\tdiagram\tshows\tthat\tthe \treaction\tis\texothermic.   .   ...   [1]",
            "13": "13 0620/32/f/m/19 \u00a9 ucles 2019 [turn over  (c)\t\tchromium\tis\ta\ttransition\telement.\tsodium\tis\tan\telement\tin\tgroup\ti\tof\tthe\tperiodic\t table.   describe two\tways\tin\twhich\tthe\tproperties\tof\tchromium\tare\tdifferent\tfrom\tthose\tof\tsodium.  1  .  2  .  [2]  (d)\t\tchromium\tis\ta\tsilver-coloured\tmetal. \t\tthe\tdiagram\tshows\thow\ta\tcopper\tspoon\tcan\tbe\telectroplated\twith\tchromium. powe r suppl y  (i)\t\ton\tthe\tdiagram,\tlabel: \t \u25cf\t the\tcathode \t \u25cf\t the\telectrolyte.  [2]  (ii)\t\tgive\tone\tobservation\tthat\tis\tmade\tduring\tthe\telectroplating\tprocess.   ...   [1]  (iii)\t\tsuggest\tone\treason\twhy\tmetal\tobjects\t are\telectroplated.   ...   [1]  (e)\t\tnichrome\tis\tan\talloy\tof\tnickel,\tiron\tand\tchromium.   which one\tof\tthese\tdiagrams,\tj,\tk,\tl or m,\tbest\trepresents\tnichrome? j k l m   ..   [1] \t [total:\t12]",
            "14": "14 0620/32/f/m/19 \u00a9 ucles 2019 7\t\tthis\tquestion\tis\tabout\talkanes\tand\tpetroleum\tfractions.  (a)\t\tthe\ttable\tgives\tsome\tinformation\tabout\talkanes. alkanenumber\tof\tcarbon atoms\tin\teach\tmoleculemelting\tpoint in \u00b0cboiling\tpoint in \u00b0c methane 1 \u2013182 \u2013164 ethane 2 \u2013183 \u201388 propane 3 \u2013190 \u201342 butane 4 \u2013135 0   answer\tthese\tquestions\tusing\tonly\tinformation\tfrom\tthe\ttable.  (i)\t\tdescribe\thow\tthe\tboiling\tpoints\tof\tthe\talkanes\tvary\twith\tthe\tnumber\tof\tcarbon\tatoms\tin\t each\tmolecule.   .   ...   [1]  (ii)\t\twhich\talkane\thas\tthe\tlowest\tmelting\tpoint?   ...   [1]  (iii)\t\tdeduce\tthe \tphysical\tstate\tof\tbutane\tat\t\u201350\t \u00b0c. \t \texplain\tyour\tanswer.   .   ...   [1]  (b) (i)\t\tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\ta\tmolecule\tof\t methane.\tshow\touter\tshell\telectrons\tonly. c hh h h  [1]",
            "15": "15 0620/32/f/m/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group.  cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (ii)\t\tcomplete\tthe\tword\tequation\tfor\tthe\tcomplete\tcombustion\tof\tmethane. methane\t\t+\t\toxygen\t\t +  [2]  (c)\t\tcomplete\tthe\tsentences\tabout\thomologous\tseries\tusing\twords\tfrom\tthe\tlist.  acidic alkenes alcohol carbohydrates  chemical functional hydrocarbons physical \t\tmethane\tand\tethane\tare\t.\twhich\tbelong\tto\tthe\tsame\t\thomologous\tseries. \t\tmembers\t of\tthe\talkane\thomologous\t series\thave\tsimilar\t.\t properties\t due    to\tthe\tpresence\tof\tthe\tsame\t.\tgroup.  [3]  (d)\t\tpetroleum\tis\tseparated\tinto\tuseful\tfractions\tby\tfractional\tdistillation. \t\tmatch\tthe\tfractions\ton\tthe\tleft\twith\tthe\tuses\ton\tthe\tright. \t\tthe\tfirst\tone\thas\tbeen\tdone\tfor\tyou. fraction use refinery\tgas fuel for aircraft bitumen bottled\tgas\tfor\theating kerosene fraction making\tchemicals naphtha\tfraction making\troads  [2] \t [total:\t11]",
            "16": "16 0620/32/f/m/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_m19_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/42 paper 4  theory (extended) february/march 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib19 03_0620_42/4rp\u00a9 ucles 2019 *4970364461* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/f/m/19 \u00a9 ucles 2019 1  period 3 of the periodic table is shown. sodium magnesium aluminium silicon phosphorus sulfur chlorine argon   answer the following questions using only these elements.   each element may be used once, more than once or not at all.   state which element:  (a)  is a gas at room temperature and pressure   ..   [1]  (b)  forms a basic oxide with a formula of the form x2o   ..   [1]  (c)  is made of atoms which have a full outer shell of electrons   ..   [1]  (d)  forms an oxide which causes acid rain   ..   [1]  (e)  is extracted from bauxite   ..   [1]  (f)  forms an oxide which has a macromolecular structure   ..   [1]  (g)  consists of diatomic molecules.   ..   [1]  [total: 7]",
            "3": "3 0620/42/f/m/19 \u00a9 ucles 2019 [turn over 2 (a)  the table gives information about some atoms or ions, a, b and c.   complete the table. number of protonsnumber of electronselectronic structurecharge a 11 10 2,8 b 18 0 c 10 2,8 \u20131  [4]  (b) (i)  carbon is an element. \t \tdefine\tthe\tterm\telement .   .   ...   [1]  (ii)  12c6, 13c6 and 14c6 are isotopes of carbon.   complete the table. number of protons number of neutrons 12c6 13c6 14c6  [2]  [total: 7]",
            "4": "4 0620/42/f/m/19 \u00a9 ucles 2019 3  fluorine is a group vii element. fluorine forms compounds with metals and non-metals.  (a)\t\tpredict\tthe\tphysical\tstate\tof\tfluorine\tat\troom\ttemperature\tand\tpressure.   ..   [1]  (b)  fluorine exists as diatomic molecules.   complete the dot-and-cross diagram to show the electron arrangement in a molecule of  fluorine.\tshow\touter\tshell\telectrons\tonly. ff  [2]  (c)\t\twrite\ta\tchemical\tequation\tfor\tthe\treaction\tbetween\t sodium\tand\tfluorine.   ..   [2]  (d)  explain why chlorine does not\treact\twith\taqueous\tsodium\tfluoride.      ..   [1]",
            "5": "5 0620/42/f/m/19 \u00a9 ucles 2019 [turn over  (e)\t\ttetrafluoromethane\t and\tlead( ii)\tfluoride\tare\tfluorides\t of\tgroup\tiv\telements.\t some\tproperties\t of\ttetrafluoromethane\tand\tlead( ii)\tfluoride\tare\tshown\tin\tthe\ttable. property tetrafluoromethane lead( ii)\tfluoride formula cf4 melting point / \u00b0c \u2013184 855 boiling point / \u00b0c \u2013127 1290 conduction of electricity when solid non-conductor non-conductor conduction of electricity when molten non-conductor good conductor  (i)\t\twhat\tis\tthe\tformula\tof\tlead( ii)\tfluoride?   ...   [1]  (ii)\t\twhat\ttype\tof\tbonding\tis\tpresent\tbetween\tthe\tatoms\tin\ttetrafluoromethane?   ...   [1]  (iii)\t\twhat\ttype\tof\tstructure\tdoes\tsolid\tlead( ii)\tfluoride\thave?   ...   [1]  (iv)\t\texplain,\t in\tterms\tof\tattractive\t forces\tbetween\t particles,\t why\tlead( ii)\tfluoride\thas\ta\tmuch\t higher\tmelting\tpoint\tthan\ttetrafluoromethane.   in your answer refer to the types of attractive forces between particles and their relative  strengths.   .   .   .   ...   [3]",
            "6": "6 0620/42/f/m/19 \u00a9 ucles 2019  (f)\t\ttetrafluoroethene\tis\tan\tunsaturated\tcompound\twith \tthe\tformula\tc2f4. \t \ttetrafluoroethene\tis\tthe\tmonomer\tused\tto\tmake\tthe\tpolymer\tpoly(tetrafluoroethene).  (i)  what is meant by the term unsaturated ?   .   ...   [1]  (ii)\t\tdescribe\ta\t test\tto\tshow\tthat\ttetrafluoroethene\tis\tunsaturated.  test ...  observations    [2]  (iii)\t\tdraw\tthe\tstructure\t of\ta\tmolecule\t of\ttetrafluoroethene.\t show\tall\tof\tthe\tatoms\tand\tall\tof\tthe\t bonds.  [1]  (iv)\t\ttetrafluoroethene\tcan\tbe\tpolymerised\tto \tform\tpoly(tetrafluoroethene).   draw one\trepeat\tunit\tof\tpoly(tetrafluoroethene).\t show\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [2]  (v)  deduce the empirical formula of: \t tetrafluoroethene\t   \t poly(tetrafluoroethene).\t  ..  [2]  [total: 20]",
            "7": "7 0620/42/f/m/19 \u00a9 ucles 2019 [turn over 4  this question is about ethanoic acid, ch3cooh.  (a)  ethanoic acid is manufactured from methanol and carbon monoxide. ch3oh(g)\t\t+\t\tco(g)\t\t   ch3cooh(g)   the process is done at 200 \u00b0c and 30 atmospheres pressure.   the forward reaction is exothermic.   complete the table using only the words increases , decreases  or no change . effect on the rate of the forward reactioneffect on the equilibrium yield of ch3cooh(g) adding a catalyst no change increasing the temperature decreasing the pressure decreases  [4]  (b)  how would you show that an aqueous solution of ethanoic acid is an acid without  using an  indicator\tor\tmeasuring\tthe\tph?   state the reagent you would use and give the expected observations. write a chemical equation  for the reaction that you describe.  \u25cf reagent     \u25cf expected observations        \u25cf chemical equation     [3]",
            "8": "8 0620/42/f/m/19 \u00a9 ucles 2019  (c)\t\tethanoic\tacid\tis\ta\tweak\tacid.  (i)  what is meant by the term acid\t?   .   ...   [1]  (ii)  why is ethanoic acid described as weak ?   .   ...   [1]  (d)  ethanoic acid reacts with methanol to form an ester.  (i)  state two conditions required for this reaction.  1  ..  2  ..  [2]  (ii)  draw the structure of the ester formed when ethanoic acid reacts with methanol. show all  of the atoms and all of the bonds. name the ester.  structure  name  ...  [3]  (iii)  name an ester which is a structural isomer of the ester in (d)(ii).   ...   [1]  [total: 15]",
            "9": "9 0620/42/f/m/19 \u00a9 ucles 2019 [turn over 5\t\ttitanium\tis\textracted\tfrom\tan\tore\tcalled\trutile.\trutile\tis\tan\timpure\tform\tof\ttitanium( iv) oxide, tio2.  (a)\t\trutile\tis\tmixed\twith\tcoke\tand\theated\tin\ta\tfurnace\tthrough\twhich\tchlorine\t gas\tis\tpassed.\t the\t product\tis\tgaseous\ttitanium( iv) chloride, ticl 4. tio2(s)\t\t+\t\t2c(s)\t\t+\t\t2c l 2(g)\t\t   tic l 4(g)\t\t+\t\t2co(g) \t \tthe\tgaseous\t titanium( iv) chloride produced is condensed into the liquid state. the  titanium( iv) chloride is then separated from liquid impurities.  (i)\t\tsuggest\t the\tname\tof\tthe\tprocess\t by\twhich\tliquid\ttitanium( iv) chloride could be separated  from the liquid impurities.   ...   [1]  (ii)\t\tcarbon\tmonoxide,\tco(g),\tis\talso\tproduced\tin\tthe\treaction.   why should carbon monoxide not\tbe\treleased\tinto\tthe\tatmosphere?   ...   [1]  (b)  calculate the volume of chlorine gas, cl 2(g),\tat\troom\ttemperature\t and\tpressure,\t that\treacts\t completely with 400 g of tio2(s)\tusing\tthe\tfollowing\tsteps. tio2(s)\t\t+\t\t2cl 2(g)\t\t+\t\t2c(s)\t\t   tic l 4(g)\t\t+\t\t2co(g)  \u25cf calculate the relative formula mass, mr, of tio2.  mr of tio2 = ..  \u25cf calculate the number of moles in 400 g of tio2.  .. mol  \u25cf determine the number of moles of c l 2 that react with 400 g of tio2.  moles of cl 2 = .. mol  \u25cf calculate the volume of c l 2 that reacts with 400 g of tio2.  volume of cl 2 = .. dm3  [4]",
            "10": "10 0620/42/f/m/19 \u00a9 ucles 2019  (c)\t\ttitanium( iv) chloride, ticl 4, is heated with an excess of magnesium, in an atmosphere of  argon.  (i)  balance the chemical equation for the reaction. tic l 4\t\t+\t\t.\tmg\t\t \t\tti\t\t+\t\t.\tmgc l 2  [1]  (ii)\t\ttitanium( iv) chloride can be reacted with sodium instead of magnesium. \t \tthe\treaction\t between\t titanium( iv) chloride and sodium is similar to the reaction between  titanium( iv) chloride and magnesium. \t \twrite\ta\tchemical\tequation\tfor\tthe\treaction\tbetween\ttitanium( iv) chloride and sodium.   ...   [1]  (iii)\t\tsuggest\t why\tthe\treaction\t between\t titanium( iv) chloride and magnesium is done in an  atmosphere of argon and not in air.   .   ...   [1]  (d)\t\tafter\ttitanium( iv) chloride is heated with magnesium, the unreacted magnesium is removed  by adding an excess of dilute hydrochloric acid to the mixture.   the dilute hydrochloric acid also dissolves the magnesium chloride.   the dilute hydrochloric acid does not react with the titanium or dissolve it.  (i)  give two observations and write a chemical equation for the reaction that occurs when  dilute hydrochloric acid reacts with magnesium.  1  ..  2  ..  chemical equation  ...  [3]  (ii)  name the process that is used to separate the titanium from the mixture after all the  magnesium has been removed.   ...   [1]  (iii)  titanium does not react with the dilute hydrochloric acid or dissolve in it.   suggest why titanium does not react with dilute hydrochloric acid.   ...   [1]",
            "11": "11 0620/42/f/m/19 \u00a9 ucles 2019 [turn over  (e) \tmagnesium\t cannot\tbe\tproduced\t by\telectrolysis\t of\taqueous\t magnesium\t chloride\t using\tinert\t electrodes.  (i)\t\tname\tthe\tproduct\tformed\tat\tthe\tnegative\t electrode\t (cathode)\t during\tthe\telectrolysis\t of\t aqueous magnesium chloride.   ...   [1]  (ii)  suggest how magnesium can be produced from magnesium chloride by electrolysis.   ...   [1]  [total: 16]",
            "12": "12 0620/42/f/m/19 \u00a9 ucles 2019 6  this question is about transition elements.  (a)  transition elements are harder and stronger than group i elements.   describe two other differences in physical properties between transition elements and group i  elements.  1  .  2  .  [2]  (b)  state one physical property of transition elements that is similar to group i elements.   ..   [1]  (c)  state two chemical properties of transition elements.  1  .  2  .  [2]  (d)\t\tcobalt\tis\ta\ttransition\telement.\t anhydrous\tcobalt( ii) chloride is used to test for water. \t \tstate\tthe\tcolour\tchange\tthat\toccurs\twhen\twater\tis\tadded\tto\tanhydrous\tcobalt( ii) chloride.  from ...  to  ..  [2]  (e)  iron is a transition element.  (i)  which two\tsubstances\treact\twith\tiron\tto \tform\trust?  1  ..  2  ..  [2]  (ii)\t\twhich\tmetal\tis\tused\tto\tgalvanise\tiron?   ...   [1]",
            "13": "13 0620/42/f/m/19 \u00a9 ucles 2019 [turn over  (f)\t\tthe\thull\tof\ta\tship\tis\tmade\tfrom\tsteel\t(mainly\tiron).\tmetal\tblocks\tare\tplaced\ton\tthe\tship\u2019s\thull\tto\t prevent rusting. water water metal blockship\u2019s hull \t \tuse\tyour\tknowledge\tof\tthe\treactivity\tseries\tto\texplain\twhy:  \u25cf\tmagnesium\tis\tsuitable\tto\tuse\tas\tthe\tmetal\tblocks  \u25cf copper is not\tsuitable\tto\tuse\tas\tthe\tmetal\tblocks.         ..   [2]  (g)\t\trust\tcontains\tiron( iii) oxide.   phosphoric acid, h3po4, can be used to remove rust from an iron object and prevent further  rusting.  (i)\t\twrite\ta\tchemical\t equation\t for\tthe\treaction\t between\t iron(iii) oxide and phosphoric acid to  form\tiron( iii) phosphate and water.   ...   [2]  (ii)\t iron( iii) phosphate is an insoluble salt. \t \tsuggest\thow\tthe\tformation\tof\tiron( iii) phosphate prevents further rusting.   .   ...   [1]  [total: 15]",
            "14": "14 0620/42/f/m/19 \u00a9 ucles 2019blank page",
            "15": "15 0620/42/f/m/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group.  cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/42/f/m/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_m19_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 7 and 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52 paper 5  practical test february/march 2019  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge assessment international education cambridge international general certificate of secondary education this document consists of 8 printed pages. [turn overib19 03_0620_52/4rp\u00a9 ucles 2019 *4722898336* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/52/f/m/19 \u00a9 ucles 2019 1  you are going to investigate the reaction between two different solutions, a and b, of  aqueous potassium manganate( vii) and solution c.   read all the instructions carefully before starting the experiments.   instructions   you are going to do three experiments.  (a) experiment 1  \u25cf fill the burette up to the 0.0 cm3 mark with solution a.  \u25cf use the 25 cm3 measuring cylinder to pour 25 cm3 of solution c into the conical flask.  \u25cf add about 1 cm3 of solution a to the conical flask and swirl the conical flask.  \u25cf continue to add solution a to the conical flask until the mixture just turns permanently pink.   \u25cf record the burette readings in the table and complete the table.  \u25cf pour about 2  cm3 of the contents of the conical flask into a test-tube.  \u25cf pour away the rest of the contents of the conical flask and rinse the conical flask with  distilled water.   keep the test-tube from experiment 1 to use in experiment 3. experiment 1 final burette reading / cm3 initial burette reading / cm3 volume used / cm3  [2]  (b) experiment 2  \u25cf pour away the contents of the burette and rinse the burette with distilled water.  \u25cf rinse the burette with solution b.  \u25cf fill the burette up to the 0.0 cm3 mark with solution b.  \u25cf use the 25 cm3 measuring cylinder to pour 25 cm3 of solution c into the conical flask.  \u25cf add about 1 cm3 of solution b to the conical flask and swirl the conical flask.  \u25cf continue to add solution b to the conical flask until the mixture just turns permanently pink.  \u25cf record the burette readings in the table and complete the table. experiment 2 final burette reading / cm3 initial burette reading / cm3 volume used / cm3  [2]",
            "3": "3 0620/52/f/m/19 \u00a9 ucles 2019 [turn over  (c)  experiment 3  (i)  add aqueous sodium hydroxide to about 2 cm3 of solution c in a test-tube.   record your observations.   ...   [1]  (ii)  add aqueous sodium hydroxide to the reaction mixture in the test-tube saved from  experiment 1.   record your observations.   ...   [1]  (d) (i)  which solution of potassium manganate( vii), solution a or solution b, is the more  concentrated?   explain your answer.   .   ...   [2]  (ii)  how many times more concentrated is this solution of potassium manganate( vii)?   ...   [1]  (e) (i)  predict the volume of solution b that would be used if experiment 2 were repeated using  50 cm3 of solution c.   explain your answer.   .   ...   [2]  (ii)  suggest a practical problem that using 50 cm3 of solution c could cause. how could this  problem be solved?   .   ...   [2]  (f)  give one advantage and one disadvantage of using a measuring cylinder rather than a pipette  for solution c.  advantage of using a measuring cylinder  ..     disadvantage of using a measuring cylinder  .     [2]  (g)  what conclusions can be drawn about solution c from experiment 3?      ..   [2]  [total: 17]",
            "4": "4 0620/52/f/m/19 \u00a9 ucles 2019 2  you are provided with two substances, solution d and solid e.   do the following tests on the substances, recording all of your observations at each stage.   tests on solution d   divide solution d into five approximately equal portions in five test-tubes.  (a)  test the ph of the first portion of solution d.  ph = ..  [1]  (b)  add a strip of magnesium ribbon to the second portion of solution d. shake the mixture. test  the gas produced.   record your observations.         ..   [3]  (c)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous silver nitrate to the third portion  of solution d.   record your observations.   ..   [1]  (d)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous barium nitrate to the fourth  portion of solution d.   record your observations.   ..   [1]   keep the fifth portion of solution d for the test in (g).   tests on solid e  (e) describe the appearance of solid e.   ..   [1]  (f) (i)  use a spatula to place half of solid e into a hard-glass test-tube. heat the solid gently and then more strongly. leave the hard-glass test-tube to stand for five minutes to cool.   record your observations.   ...   [1]  (ii)  now add about 2 cm 3 of distilled water to the residue in the hard-glass test-tube. test the  ph of the mixture.  ph = ... ...  [1]",
            "5": "5 0620/52/f/m/19 \u00a9 ucles 2019 [turn over  (g)  add the rest of solid e to the fifth portion of solution d. test the gas produced.   record your observations.         ..   [3]   keep the solution from the test in (g) for the test in (h).  (h)  add an approximately equal volume of distilled water to the solution from the test in (g) and  shake the mixture.   add an excess of aqueous sodium hydroxide to the mixture.   record your observations.   ..   [1]  (i)  identify solution d.   ..   [2]  (j)  what conclusions can you draw about solid e?   ..   [2]  [total: 17]",
            "6": "6 0620/52/f/m/19 \u00a9 ucles 2019 3  the rate of reaction between magnesium and dilute hydrochloric acid can be followed by measuring  the volume of hydrogen produced.   plan an experiment to investigate the effect of decreasing the temperature on the rate of this reaction by measuring the volume of hydrogen produced.   you are provided with magnesium ribbon, dilute hydrochloric acid and common laboratory apparatus.   you are advised to draw a labelled diagram of the apparatus you would use in the space provided.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "7": "7 0620/52/f/m/19 \u00a9 ucles 2019notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh 4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "8": "8 0620/52/f/m/19 \u00a9 ucles 2019tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group.  cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_m19_qp_62.pdf": {
            "1": "this document consists of 9 printed pages and 3 blank pages. [turn overib19 03_0620_62/4rp \u00a9 ucles 2019 *3799843157* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62 paper 6  alternative to practical february/march 2019  1 hour candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/f/m/19 \u00a9 ucles 2019 1  a chemist heated solid zinc chloride until it became molten. the apparatus shown was then used  to pass electricity through the molten zinc chloride using inert electrodes. +\u2013power supply molten zinc chloride   a silver-coloured solid was formed at the negative electrode (cathode).  (a)  name the process of breaking down a substance using electricity.   ..   [1]  (b)  a bunsen burner was used to heat the zinc chloride. \t \tdescribe\thow\ta\tbunsen\tburner\tis\tadjusted\tto\tgive\ta\tvery\thot\tflame.      ..   [1]  (c)  suggest and explain the expected observation at the positive electrode (anode).      ..   [2]  (d)  suggest why iron electrodes cannot be used in this experiment.   ..   [1]",
            "3": "3 0620/62/f/m/19 \u00a9 ucles 2019 [turn over  (e) (i)  what difference would the chemist observe at the negative electrode if aqueous  zinc chloride were used, rather than molten zinc chloride?   explain you answer.  difference    explanation  .   .  [2]  (ii)  when electricity is used to break down concentrated aqueous zinc chloride, chlorine is  produced at the positive electrode.   describe a test for chlorine.  test  ..  observations  ...  [2]  (f)  the bottle of zinc chloride is labelled corrosive .   state one safety precaution that should be taken when using zinc chloride.   ..   [1]  [total: 10]",
            "4": "4 0620/62/f/m/19 \u00a9 ucles 2019 2  a student investigated the reaction between two different solutions, a and b, of aqueous  potassium manganate( vii) and solution c.   three experiments were done.  experiment 1  \u25cf a burette was filled with solution a. the initial burette reading was recorded.  \u25cf a measuring cylinder was used to pour 25 cm3 of solution c into a conical flask.  \u25cf solution a was added to the conical flask until the mixture just turned pink. the final burette  reading was recorded.  \u25cf about 2 cm3 of the contents of the conical flask was poured into a test-tube to use in experiment 3.  \u25cf the rest of the contents of the conical flask was poured away. the conical flask was rinsed  with distilled water.  (a)  use the burette diagrams to record the burette readings in the table and complete the table. 1 23 initial burette reading151617 final burette reading experiment 1 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tused\t /\tcm3  [2]",
            "5": "5 0620/62/f/m/19 \u00a9 ucles 2019 [turn over  experiment 2  \u25cf the contents of the burette used in experiment 1 were poured away and the burette was  rinsed with distilled water.  \u25cf the burette was then rinsed with solution b.  \u25cf experiment 1 was repeated using solution b instead of solution a.  (b)  use the burette diagrams to record the burette readings in the table and complete the table. 1 2 3 initial burette reading31 32 33 final burette reading experiment 2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tused\t /\tcm3  [2]  (c) (i)  which solution of potassium manganate( vii), solution a or solution b, is the more  concentrated?   explain your answer.   .   ...   [2]  (ii)  how many times more concentrated is this solution of potassium manganate( vii)?   ...   [1]",
            "6": "6 0620/62/f/m/19 \u00a9 ucles 2019  (d) (i)  predict the volume of solution b that would be used if experiment 2 were repeated using  50 cm3 of solution c.   explain your answer.   .   ...   [2]  (ii)  suggest a practical problem that using 50 cm3 of solution c could cause. how could this  problem be solved?   .   ...   [2]  (e)  give one advantage and one disadvantage of using a measuring cylinder rather than a pipette  for solution c.  advantage of using a measuring cylinder  ..     disadvantage of using a measuring cylinder  .     [2]   experiment 3   the results from experiment 3 are shown in the table. tests observations aqueous sodium hydroxide was added to  about 2 cm3 of solution c.green precipitate formed aqueous sodium hydroxide was added to the  reaction mixture saved from experiment 1.red-brown precipitate formed  (f)  what conclusions can be drawn about solution c from experiment 3?      ..   [2]  [total: 15] ",
            "7": "7 0620/62/f/m/19 \u00a9 ucles 2019 [turn over 3  two substances, solution d and solid e, were analysed. solution d was dilute sulfuric acid.   tests were done on the substances.  tests on solution d   complete the expected observations.   solution d was divided into four equal portions in four test-tubes.  (a)\t\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\td was tested.  ph = ..  [1]  (b)  a strip of magnesium ribbon was added to the second portion of solution d. the gas produced  was tested.  observations  ..      ..   [3]  (c)  dilute nitric acid and aqueous silver nitrate were added to the third portion of solution d.  observations     [1]  (d)  dilute nitric acid and aqueous barium nitrate were added to the fourth portion of solution d.  observations     [1]",
            "8": "8 0620/62/f/m/19 \u00a9 ucles 2019  tests on solid e   some of the tests and observations are shown. tests on solid e observations the appearance of solid e was studied. white solid test 1 solid e was heated gently and then more  strongly. distilled water was added to the residue and  the ph of the mixture was tested.white solid residue ph = 10 test 2 dilute hydrochloric acid was added to solid e. the gas produced was tested. distilled water was added to the solution and  the mixture was shaken. an excess of aqueous sodium hydroxide was  added to the mixture.rapid effervescence limewater turned milky white precipitate formed which was insoluble in excess  (e)  identify the gas produced in test 2.   ..   [1]  (f)  what conclusions can you draw about solid e?   ..   [2]  [total: 9]",
            "9": "9 0620/62/f/m/19 \u00a9 ucles 2019 [turn over 4  the rate of reaction between magnesium and dilute hydrochloric acid can be followed by measuring  the volume of hydrogen produced.   plan an experiment to investigate the effect of decreasing the temperature on the rate of this reaction by measuring the volume of hydrogen produced.   you are provided with magnesium ribbon, dilute hydrochloric acid and common laboratory  apparatus.   you are advised to draw a labelled diagram of the apparatus you would use in the space provided.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "10": "10 0620/62/f/m/19 \u00a9 ucles 2019blank page",
            "11": "11 0620/62/f/m/19 \u00a9 ucles 2019blank page",
            "12": "12 0620/62/f/m/19 \u00a9 ucles 2019blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group.  cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s19_qp_11.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level1/level 2 certifica te.  this document consists of 15 printed pages and 1 blank page.  ib19 06_0620_11/3rp  \u00a9 ucles 2019   [turn over     *7680430453 * cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1  multiple choice (core)  may/june 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.    ",
            "2": "2  \u00a9 ucles 2019 0620/11/m/j/19  1 sodium chloride is a liquid at 900  \u00b0c.    how are the particles arranged and how do the particles move in sodium chloride at 900  \u00b0c?     arrangement of particles motion of particles  a regular vibrate about a fixed point  b regular move randomly  c random vibrate about a fixed point  d random move randomly      2 2.00  g of powdered calcium carbonate is added to 50.0  cm3 of hydrochloric acid.    which apparatus is used to measure the calcium carbonate and the hydrochloric acid?     calcium carbonate hydrochloric acid  a balance burette  b balance thermometer  c pipette burette  d pipette thermometer     3 rock salt is a mixture of sand and sodium chloride.    sodium chloride is soluble in water but not in hexane.    sand is insoluble in both water and hexane.    what is required to separate the sand from the sodium chloride?    1 filter paper  2 fractionating column  3 hexane  4 water    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "3": "3  \u00a9 ucles 2019 0620/11/m/j/19 [turn over  4 the colours in four dyes are separated using chromatography.    which chromatogram shows an insoluble colour?    a baselineb c d       5 which statement about an atom of fluorine, f19 9, is correct?  a it contains more protons than neutrons.  b it contains a total of 28 protons, neutrons and electrons.  c its isotopes contain different numbers of protons.  d its nucleus contains 9 neutrons.      6 calcium reacts with chlorine to produce calcium chloride.    what happens when a calcium ion forms during this reaction?  a the calcium atom gains one electron.  b the calcium atom gains two electrons.  c the calcium atom loses one electron.  d the calcium atom loses two electrons.      7 which row describes the formation of single covalent bonds in methane?    a   atoms share a pair of electrons   both atoms gain a  noble gas electronic structure  b   atoms share a pair of electrons   both atoms have the same number  of electrons in their outer shell  c   electrons are transferred from one  atom to another both atoms gain a  noble gas electronic structure  d   electrons are transferred from one  atom to another both atoms have the same number  of electrons in their outer shell     ",
            "4": "4  \u00a9 ucles 2019 0620/11/m/j/19  8 diamond and graphite have giant covalent structures of carbon atoms.    which statement describes graphite?  a it has a strong, rigid three-dimensional structure.  b it has four strong covalent bonds between each carbon atom.  c it has layers, which can slide over each other.  d it has no free electrons, so does not conduct electricity.     9 the compound magnesium nitrate has the formula mg(no 3)2.    what is the relative formula mass of magnesium nitrate?    a 86 b 134 c 148 d 172    10 four substances are electrolysed using inert electrodes.    which row describes the electrode products?     substance anode product cathode product  a concentrated aqueous sodium chloride hydrogen chlorine  b concentrated hydrochloric acid chlorine oxygen  c dilute sulfuric acid oxygen hydrogen  d molten lead bromide lead bromine      11 dissolving ammonium chloride in water is an endothermic change.    which row shows the energy change and temperature change of the mixture during the dissolving of ammonium chloride?     energy change temperature change  a energy is absorbed decrease  b energy is absorbed increase  c energy is released decrease  d energy is released increase     12 which process is a physical change?  a burning wood  b cooking an egg  c melting an ice cube  d rusting iron ",
            "5": "5  \u00a9 ucles 2019 0620/11/m/j/19 [turn over  13 hydrogen peroxide solution decomposes very slowly at room temperature to produce oxygen  gas. this gas forms a rising foam when liquid detergent is added.    five test-tubes are half filled with hydrogen peroxide solution. a drop of liquid detergent is added  to each one.    different metal oxides are added to four of the test-tubes and the height of the foam formed after  1 minute is measured. the results are shown.    metal oxide height of  foam  / cm  no metal oxide added 0.1  aluminium oxide 0.1  calcium oxide 0.2  copper( ii) oxide 2.3  manganese( iv) oxide 5.4    which conclusion can be drawn from these results?  a metal oxides do not affect the rate of this reaction.  b all metal oxides increase the rate of this reaction and act as catalysts.  c manganese( iv) oxide is the best catalyst of the four metal oxides tested.  d only transition element oxides increase the rate of this reaction.      14 when blue-green crystals of nickel( ii) sulfate are heated, water is produced and a yellow solid  remains. when water is added to the yellow solid, the blue-green colour returns.     which process describes these changes?   a combustion  b corrosion  c neutralisation   d reversible reaction     ",
            "6": "6  \u00a9 ucles 2019 0620/11/m/j/19  15 in a blast furnace, iron is extracted when iron( iii) oxide reacts with carbon monoxide.    the equation is shown.    fe2o3  +  3co  \u2192  2fe  +  3co 2    which substance is oxidised and which is reduced?     oxidised reduced  a co fe 2o3  b co 2 fe  c fe co 2  d fe2o3 co     16 four different solutions are separately tested with blue litmus and with methyl orange. each  solution is known to be either acidic or alkaline. the results are shown.    solution result with  blue litmus result with  methyl orange  1 red red  2 red yellow  3 blue yellow  4 blue yellow    which statement is correct?  a solutions 1 and 4 are acidic.  b solutions 1 and 2 are alkaline.  c solutions 3 and 4 are alkaline.  d solutions 3 and 4 are acidic.     17 the positions of elements w, x, y and z in the periodic table are shown.    w xy z    which elements form basic oxides?  a w, x and y b w and x only c y only d z only   ",
            "7": "7  \u00a9 ucles 2019 0620/11/m/j/19 [turn over  18 how could crystals of a pure salt be prepared from dilute sulfuric acid?  a add an excess of aqueous sodium hydroxide, filter, evaporate the filtrate to crystallisation  point  b add an excess of copper( ii) carbonate, filter, evaporate the filtrate to dryness  c add an excess of copper metal, filter, evaporate the filtrate to crystallisation point  d add an excess of zinc oxide, filter, evaporate the filtrate to crystallisation point      19 the results of two tests on a solution of compound q are shown.    test observation  add ammonia solution green precipitate formed  add dilute nitric acid followed  by aqueous barium nitrate white precipitate formed      what is q?  a iron( ii) chloride  b iron( ii) sulfate  c iron( iii) chloride  d iron( iii) sulfate     20 the properties of an element are shown.    electrical conductivity density reaction with water  high low reacts violently with cold water    which element has these properties?    a c db       21 which statement about elements in group i and group vii of the periodic table is correct?  a bromine reacts with potassium chloride to produce chlorine.  b iodine is a monoatomic non-metal.  c lithium has a higher melting point than potassium.  d sodium is more reactive with water than potassium. ",
            "8": "8  \u00a9 ucles 2019 0620/11/m/j/19  22 which row describes the properties of a transition element?     melting  point density forms coloured  compounds  a high low no  b high high yes  c low low no  d low low yes      23 which statement about elements in group viii of the periodic table is correct?  a they all have a full outer shell of electrons.  b they all react with group i elements to form ionic compounds.  c they are all diatomic molecules.  d they are all liquids at room temperature.      24 the diagrams show the structure of two substances used to make electrical conductors.    xy     which statement correctly describes x and y?  a x is a pure metal and y is a compound.  b x is a pure metal and y is an alloy.  c x is a solid and y is a liquid.  d x is harder and stronger than y.     ",
            "9": "9  \u00a9 ucles 2019 0620/11/m/j/19 [turn over  25 the reactions of three metals, p, q and r, are shown.     metal reacts with  dilute hydrochloric acid metal reacts  with water  p yes no  q no no  r yes yes    what is the order of reactivity of the metals?     most  reactive  least  reactive  a p q r  b q r p  c r q p  d r p q      26 iron is extracted from its ore in a blast furnace.    hematite, coke, limestone and hot air are added to the furnace.    which explanation is not correct?  a coke burns and produces a high temperature.  b hematite is the ore containing the iron as iron( iii) oxide.  c hot air provides the oxygen for the burning.  d limestone reduces the iron( iii) oxide to iron.      27 why is aluminium used to make containers for storing food?  a it conducts electricity.  b it has a high melting point.  c it is resistant to corrosion.  d it is strong.    ",
            "10": "10  \u00a9 ucles 2019 0620/11/m/j/19  28 water can be treated by filtration then chlorination.    which uses do not need water of this quality?    1 water for cooling in industry  2 water for washing clothes 3 water for drinking    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      29 four sources of air pollution are listed.    1 burning fossil fuels containing sulfur  2 nitrogen reacting with oxygen in car engines  3 incomplete combustion of carbon fuels  4 adding lead compounds to petrol    which sources produce acid rain?  a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4     30 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change     ",
            "11": "11  \u00a9 ucles 2019 0620/11/m/j/19 [turn over  31 a mixture of two substances, r and s, is heated.    the damp red litmus paper turns blue.    damp red litmus pape r r and s gentle heat    what are r and s?     r s  a a basic oxide ammonium chloride  b a basic oxide sodium nitrate  c an acidic oxide ammonium chloride  d an acidic oxide sodium nitrate      32 which statement describes a disadvantage of sulfur dioxide?  a it can be used as a bleach when making wood pulp.  b it can be used to kill bacteria in food.  c it can be used to manufacture sulfuric acid.  d it dissolves in water to form acid rain.    ",
            "12": "12  \u00a9 ucles 2019 0620/11/m/j/19  33 the diagram represents a lime kiln used to heat limestone to a very high temperature.    air infuel in fuel in air in xwaste gases limestonelime kiln     what leaves the kiln at x?  a calcium carbonate  b calcium hydroxide  c calcium oxide  d calcium sulfate     34 what is the structure of ethanol?    ch hh ho ohcab co hh hch hh ch hch hh hc ch hc hd      ",
            "13": "13  \u00a9 ucles 2019 0620/11/m/j/19 [turn over  35 which fuel could be gasoline?    is it obtained from petroleum? is it used as fuel for cars?is it used as fuel for cars?no yes no yes ab cdno yes      36 a hydrocarbon w burns to form carbon dioxide and water.    w decolourises bromine water.    what is the name of w and what is its structure?     name of w structure of w  a ethane ch hhh c h h  b ethane c c hh hh   c ethene ch hhh c h h  d ethene c c hh hh      ",
            "14": "14  \u00a9 ucles 2019 0620/11/m/j/19  37 why is ethanol a member of the homologous series of alcohols but propane is not?  a ethanol has two carbon atoms per molecule but propane has three.  b ethanol can be made from ethene but propane is obtained from petroleum.  c ethanol is a liquid but propane is a gas.  d ethanol contains the same functional group as other alcohols but propane does not.      38 which statements about ethanol are correct?    1 it can be made by fermentation.  2 it is an unsaturated compound.  3 it burns in air and can be used as a fuel.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    39 which statements about aqueous ethanoic acid are correct?    1 ethanoic acid contains the functional group \u2013cooh.  2 ethanoic acid reacts with carbonates to produce hydrogen. 3 ethanoic acid turns universal indicator paper blue. 4 ethanoic acid has a ph lower than ph 7.    a 1 and 2 b 1 and 3 c 1 and 4 d 2 and 4    40 which naturally occurring polymers are found in foods?    1 complex carbohydrates  2 nylon 3 salts 4 proteins    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    ",
            "15": "15    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/11/m/j/19  ",
            "16": "16  \u00a9 ucles 2019 0620/11/m/j/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s19_qp_12.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level1/level 2 certifica te.  this document consists of 16 printed pages.  ib19 06_0620_12/3rp  \u00a9 ucles 2019   [turn over     *2696414869* cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1  multiple choice (core)  may/june 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number  on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/12/m/j/19  1 which row describes the arrangement and motion of particles in a solid?     arrangement motion  a random move in all directions  b random stay in one place  c regular move freely  d regular vibrate about a fixed point      2 a student measures 25.00  cm3 of dilute hydrochloric acid accurately.    which apparatus is most suitable?  a beaker  b measuring cylinder  c burette  d dropping pipette    3 which sequence is used to separate a soluble salt from a mixture of a soluble and an insoluble  salt?  a add solvent, heat the mixture, crystallise the mixture  b add solvent, heat the mixture, filter, crystallise the filtrate  c heat the mixture, filter, crystallise the filtrate  d heat the mixture, filter, add solvent, crystallise the filtrate     ",
            "3": "3  \u00a9 ucles 2019 0620/12/m/j/19 [turn over  4 which diagram shows the correct level of the solvent at the start of a chromatography  experiment?    b spot of sample level of solventa spot of sample level of solvent d spot of samplelevel of solventc spot of sample level of solvent      5 what is an isotope of e31 15?  a e31 14 b e33 15 c e31 16 d e3316      6 which statement about the formation of ions in chemical reactions is correct?  a a bromine atom loses an electron and forms a \u20131 ion.  b a chlorine atom gains an electron and forms a \u20131 ion.  c a potassium atom gains an electron and forms a +1 ion.  d a sodium atom loses an electron and forms a \u20131 ion.     ",
            "4": "4  \u00a9 ucles 2019 0620/12/m/j/19  7 which row describes the formation of single covalent bonds in methane?    a   atoms share a pair of electrons   both atoms gain a  noble gas electronic structure  b   atoms share a pair of electrons   both atoms have the same number  of electrons in their outer shell  c   electrons are transferred from one  atom to another both atoms gain a  noble gas electronic structure  d   electrons are transferred from one  atom to another both atoms have the same number  of electrons in their outer shell     8 which statement explains why graphite is used as a lubricant?  a each carbon atom in graphite forms three bonds.  b the bonding in graphite is covalent.  c the carbon atoms are arranged in hexagons.  d there are weak forces between the layers of carbon atoms.     9 the compound magnesium nitrate has the formula mg(no 3)2.    what is the relative formula mass of magnesium nitrate?    a 86 b 134 c 148 d 172     10 samples of dilute sulfuric acid and concentrated hydrochloric acid are separately electrolysed.    which row describes the product at each electrode during the electrolysis of both substances?     product at  each anode product at  each cathode  a different different  b different same  c same different  d same same    ",
            "5": "5  \u00a9 ucles 2019 0620/12/m/j/19 [turn over  11 which row describes the energy level diagram and energy change in an exothermic reaction?     energy level diagram energy is  a reactants higher than products absorbed  b reactants higher than products released  c reactants lower than products absorbed  d reactants lower than products released      12 which process is a physical change?  a a firework exploding  b burning wood  c chocolate melting  d iron rusting      13 an experiment is set up as shown.    the mass of the conical flask and its contents is measured at 30 second intervals.    50 cm3 dilute hydrochloric acid balance1 g calcium carbonate     which statement about the reaction and about changes to the reaction conditions is correct?  a adding 10  cm3 of water to the 50  cm3 of acid increases the rate of the reaction.  b increasing the size of the pieces of calcium carbonate increases the rate of the reaction.  c increasing the temperature increases the rate of the reaction.  d the mass of the conical flask increases as carbon dioxide is formed.     ",
            "6": "6  \u00a9 ucles 2019 0620/12/m/j/19  14 when blue-green crystals of nickel( ii) sulfate are heated, water is produced and a yellow solid  remains. when water is added to the yellow solid, the blue-green colour returns.     which process describes these changes?   a combustion  b corrosion  c neutralisation   d reversible reaction    15 different types of reaction are listed.    1 oxidation  2 decomposition 3 combustion 4 reduction    the equation shows the reaction of magnesium with oxygen.    2mg  +  o 2  \u2192  2mgo    which types of reaction does magnesium undergo in this reaction?  a 1 and 3 b 1 only c 2 and 4 d 4 only      16 which colours are seen when litmus and methyl orange are added to separate samples of  aqueous sodium hydroxide?     litmus methyl orange  a blue orange  b blue yellow  c purple orange  d purple yellow     ",
            "7": "7  \u00a9 ucles 2019 0620/12/m/j/19 [turn over  17 the positions of elements w, x, y and z in the periodic table are shown.    w xy z    which elements form basic oxides?  a w, x and y b w and x only c y only d z only    18 an acid is neutralised by adding an excess of an insoluble solid base.    a soluble salt is formed.    how is the pure salt obtained from the reaction mixture?  a crystallisation \u2192 evaporation \u2192 filtration  b evaporation \u2192 crystallisation \u2192 filtration  c filtration \u2192 crystallisation \u2192 evaporation  d filtration \u2192 evaporation \u2192 crystallisation     19 a substance is tested with three different reagents.    which row shows the results obtained with aqueous iron( ii) nitrate?     aqueous  sodium hydroxide acidified aqueous  silver nitrate acidified aqueous  barium nitrate  a   green precipitate,  insoluble in excess no reaction   no reaction    b   green precipitate,  insoluble in excess white precipitate   white precipitate    c   white precipitate,  insoluble in excess cream precipitate   no reaction    d   white precipitate that  dissolves in excess no reaction   white precipitate      ",
            "8": "8  \u00a9 ucles 2019 0620/12/m/j/19  20 part of the periodic table is shown.    yzx     which row describes the properties of x, y and z?     good conductor  of electricity high melting  point  a x z  b y z and x  c y and z z  d z and x x     21 the melting points and boiling points of the elements of group i of the periodic table are shown.    element melting point  /  \u00b0c boiling point  / \u00b0c  lithium 181 1330  sodium 98 883  potassium 63 759  rubidium 39 688  caesium 28 671    which pair of elements are liquid at 800  \u00b0c?  a caesium and rubidium  b potassium and sodium  c lithium and sodium  d potassium and caesium    ",
            "9": "9  \u00a9 ucles 2019 0620/12/m/j/19 [turn over  22 the table gives some information about four metals, q, r, s and t.     melting point  in \u00b0c density  in g  / dm3 colour of  metal sulfate catalytic  activity  q 650 1.74 white no  r 1455  green   s 842 1.55 white no  t 1085 8.96  yes    which statements are correct?    1 t forms a coloured sulfate.  2 q and s are transition elements. 3 the density of r is 0.53  g / cm3.  4 r shows catalytic activity.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      23 the electronic structures of helium, neon and argon are shown.    he ne ar     which row describes these gases?     reactivity form of the gas electronic structure  a reactive monoatomic incomplete outer shell of electrons  b unreactive diatomic complete outer shell of electrons  c unreactive diatomic incomplete outer shell of electrons  d unreactive monoatomic complete outer shell of electrons     ",
            "10": "10  \u00a9 ucles 2019 0620/12/m/j/19  24 the diagrams show the structure of two substances used to make electrical conductors.    xy     which statement correctly describes x and y?  a x is a pure metal and y is a compound.  b x is a pure metal and y is an alloy.  c x is a solid and y is a liquid.  d x is harder and stronger than y.     25 three different metals are reacted separately with dilute hydrochloric acid and with water. the  results are shown.    metal reaction with  dilute hydrochloric acid reaction with water  r reacts no reaction  s no reaction no reaction  t reacts reacts    what is the order of reactivity of the metals starting with the most reactive?  a r \u2192 s \u2192 t  b s \u2192 r \u2192 t  c t \u2192 r \u2192 s  d t \u2192 s \u2192 r     26 iron is extracted from its ore in a blast furnace.    hematite, coke, limestone and hot air are added to the furnace.    which explanation is not correct?  a coke burns and produces a high temperature.  b hematite is the ore containing the iron as iron( iii) oxide.  c hot air provides the oxygen for the burning.  d limestone reduces the iron( iii) oxide to iron.     ",
            "11": "11  \u00a9 ucles 2019 0620/12/m/j/19 [turn over  27 which property of aluminium makes it useful in the manufacture of aircraft?  a conducts electricity  b high boiling point  c low density  d silver colour      28 water can be treated by filtration then chlorination.    which uses do not need water of this quality?    1 water for cooling in industry  2 water for washing clothes 3 water for drinking    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      29 the following gases pollute the atmosphere.    1 sulfur dioxide  2 oxides of nitrogen  3 carbon monoxide    which gases contribute to acid rain?  a 1 only b 1 and 2 c 1 and 3 d 2 and 3    ",
            "12": "12  \u00a9 ucles 2019 0620/12/m/j/19  30 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change      31 ammonia gas is produced when compound x is warmed with an ammonium salt.    what is x?  a calcium carbonate  b calcium hydroxide  c sodium chloride  d potassium nitrate      32 which statement describes a disadvantage of sulfur dioxide?  a it can be used as a bleach when making wood pulp.  b it can be used to kill bacteria in food.  c it can be used to manufacture sulfuric acid.  d it dissolves in water to form acid rain.     ",
            "13": "13  \u00a9 ucles 2019 0620/12/m/j/19 [turn over  33 the diagram represents a lime kiln used to heat limestone to a very high temperature.    air infuel in fuel in air in xwaste gases limestonelime kiln     what leaves the kiln at x?  a calcium carbonate  b calcium hydroxide  c calcium oxide  d calcium sulfate     34 what is the structure of ethanoic acid?    ch hh ho ohcbc co hh hch hh ch hch hh hd ch hc ha      ",
            "14": "14  \u00a9 ucles 2019 0620/12/m/j/19  35 which fuel could be gasoline?    is it obtained from petroleum? is it used as fuel for cars?is it used as fuel for cars?no yes no yes ab cdno yes      36 a hydrocarbon w burns to form carbon dioxide and water.    w decolourises bromine water.    what is the name of w and what is its structure?     name of w structure of w  a ethane ch hhh c h h  b ethane c c hh hh   c ethene ch hhh c h h  d ethene c c hh hh      ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/12/m/j/19 37 which statement about homologous series is not correct?  a all homologous series are hydrocarbons.  b members of a homologous series have the same functional group.  c members of a homologous series have similar chemical properties.  d the alkanes are an example of a homologous series.      38 which statements about ethanol are correct?    1 it can be made by fermentation.  2 it is an unsaturated compound.  3 it burns in air and can be used as a fuel.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    39 what are the properties of aqueous ethanoic acid?     decolourises  bromine water reacts with  calcium carbonate to  make carbon dioxide turns damp red   litmus blue  a \u0016 \u0016 \u001a  b \u0016 \u001a \u0016  c \u001a \u0016 \u001a  d \u001a \u001a \u0016     40 which polymers are found in foods?    1 carbohydrates  2 poly(ethene) 3 protein 4 terylene     a 1 only b 1 and 3 c 2 and 4 d 3 and 4     ",
            "16": "16  \u00a9 ucles 2019 0620/12/m/j/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s19_qp_13.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level1/level 2 certifica te.  this document consists of 16 printed pages.  ib19 06_0620_13/3rp  \u00a9 ucles 2019   [turn over     *3401923072 * cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1  multiple choice (core)  may/june 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/13/m/j/19  1 which row describes the arrangement and motion of the particles in a liquid?     arrangement motion  a irregular and most particles touching moving slowly  b irregular spaces between all particles moving slowly  c regular and most particles touching moving slowly  d regular spaces between all particles moving quickly      2 which piece of apparatus is used to measure 24.8  cm3 of gas produced during a reaction?  a beaker  b conical flask  c measuring cylinder  d pipette      3 calcium carbonate is insoluble in water. sodium chloride is soluble in water.    which sequence of steps is used to obtain a pure, dry sample of calcium carbonate from a  mixture of calcium carbonate and aqueous sodium chloride?  a filter \u2192 dry the residue with filter paper \u2192 wash the residue with water  b filter \u2192 heat the filtrate to crystallising point \u2192 leave the filtrate to cool and crystallise  c filter \u2192 wash the filtrate with water \u2192 dry the filtrate  d filter \u2192 wash the residue with water \u2192 dry the residue     ",
            "3": "3  \u00a9 ucles 2019 0620/13/m/j/19 [turn over  4 a student uses paper chromatography to identify the food dyes in a coloured sweet, s.    the student uses four known food dyes, w, x, y, and z, and ethanol as the solvent.    the chromatogram obtained is shown.    wxyzs    which statements are correct?    1 s contains only two dyes.  2 x is insoluble in ethanol.  3 s contains y and z.  4 s contains w.    a 1, 2 and 4 only  b 2 and 3 only  c 2 and 4 only  d 4 only    ",
            "4": "4  \u00a9 ucles 2019 0620/13/m/j/19  5 the structure of an atom is shown.    7p 8nkey = electron = neutronn = protonp     which element is the atom an isotope of?  a nitrogen  b oxygen  c phosphorus  d titanium     6 what happens when sodium atoms combine with chlorine atoms to form sodium chloride?  a sodium atoms gain one electron and chlorine atoms lose one electron.  b sodium atoms lose one electron and chlorine atoms gain one electron.  c sodium atoms and chlorine atoms share one electron with each other.  d sodium atoms and chlorine atoms share two electrons with each other.    7 which row describes the formation of single covalent bonds in methane?    a   atoms share a pair of electrons   both atoms gain a  noble gas electronic structure  b   atoms share a pair of electrons   both atoms have the same number  of electrons in their outer shell  c   electrons are transferred from one  atom to another both atoms gain a  noble gas electronic structure  d   electrons are transferred from one  atom to another both atoms have the same number  of electrons in their outer shell     8 which statement about diamond is correct?  a it is a giant covalent structure consisting of carbon atoms and each atom is bonded to four  other atoms.  b it is a giant covalent structure consisting of flat sheets of carbon atoms.  c it is a structure held together by ionic bonds and each ion is bonded to four other ions.  d it is a structure held together by ionic bonds and each ion is bonded to three other ions.   ",
            "5": "5  \u00a9 ucles 2019 0620/13/m/j/19 [turn over  9 the compound magnesium nitrate has the formula mg(no 3)2.    what is the relative formula mass of magnesium nitrate?    a 86 b 134 c 148 d 172     10 which substance does not produce a gas at both electrodes during electrolysis?  a concentrated aqueous sodium chloride  b concentrated hydrochloric acid  c dilute sulfuric acid  d molten lead( ii) bromide     11 which row describes the changes that occur when metals burn in oxygen?     temperature metal is  a decreases oxidised  b decreases reduced  c increases oxidised  d increases reduced      12 which process is a physical change?  a burning magnesium in air  b dissolving sodium chloride in water  c adding magnesium to hydrochloric acid  d heating green copper( ii) carbonate until it turns black     ",
            "6": "6  \u00a9 ucles 2019 0620/13/m/j/19  13 a student reacts strips of zinc with dilute sulfuric acid and measures the time taken to produce  100  cm3 of hydrogen.    the experiment is repeated using different conditions.    the results are shown in the table.    experiment time to produce 100  cm3  of hydrogen  / s  1 250  2 100    which changes in conditions produce the results shown in experiment 2?    1 add a catalyst.  2 dilute the acid. 3 use zinc powder.  4 heat the acid.    a 1, 3 and 4 only  b 1 and 4 only  c 2 and 3 only  d 2 and 4 only      14 when blue-green crystals of nickel( ii) sulfate are heated, water is produced and a yellow solid  remains. when water is added to the yellow solid, the blue-green colour returns.     which process describes these changes?   a combustion  b corrosion  c neutralisation   d reversible reaction    15 zinc is formed when zinc oxide is heated with carbon.    zinc oxide  +  carbon  \u2192  zinc  +  carbon monoxide    which substance is oxidised in this reaction?  a carbon  b carbon monoxide  c zinc  d zinc oxide ",
            "7": "7  \u00a9 ucles 2019 0620/13/m/j/19 [turn over  16 which row shows the colours of litmus and methyl orange with solutions of acids and bases?     solution litmus methyl orange  a acid red red  b acid blue yellow  c base blue red  d base red yellow      17 the positions of elements w, x, y and z in the periodic table are shown.    w xy z    which elements form basic oxides?  a w, x and y b w and x only c y only d z only     18 copper( ii) sulfate is made when copper( ii) carbonate reacts with dilute sulfuric acid.    cuco 3  +  h 2so 4  \u2192  cuso 4  +  h 2o  +  co 2    pure copper( ii) sulfate crystals are obtained.    which reagent is in excess and how are the crystals obtained?     reagent in excess how the crystals are obtained  a copper( ii) carbonate filter and evaporate the solution to dryness  b copper( ii) carbonate filter, evaporate to crystallising point and then cool  c dilute sulfuric acid evaporate the solution to dryness  d dilute sulfuric acid evaporate to crystallising point and then cool     ",
            "8": "8  \u00a9 ucles 2019 0620/13/m/j/19  19 two separate tests are done on a solution of a compound, x.    the results are shown.    1 adding aqueous ammonia forms a blue precipitate that dissolves in an excess of  aqueous ammonia.  2 adding dilute nitric acid and aqueous barium nitrate forms a white precipitate.    what is x?  a chromium( iii) chloride  b chromium( iii) sulfate  c copper( ii) chloride  d copper( ii) sulfate      20 part of the periodic table is shown.    xy zw     which row describes w, x, y and z?     metal non-metal  a x w, y and z  b x and y w and z  c w and z x and y  d w, y and z x      21 which statement about the properties of elements in group i and in group vii is correct?  a bromine displaces iodine from an aqueous solution of potassium iodide.  b chlorine, bromine and iodine are diatomic gases at room temperature.  c lithium, sodium and potassium are soft non-metals.  d lithium, sodium and potassium have an increasing number of electrons in their outer shells.     ",
            "9": "9  \u00a9 ucles 2019 0620/13/m/j/19 [turn over  22 some information about four elements, p, q, r and s, is shown.     melting point  in \u00b0c density  in g  / cm3 colour of  chloride  p 1247 7.43 pink  q 1410 2.33 white  r 1910 6.11 purple  s 115 2.07 red    which elements are transition elements?  a p and r b p and s c q and r d r and s    23 gas g has 10 electrons. gas h has eight more electrons than gas g. both gases are  monoatomic.    which statement about g and h is correct?  a both gases are in the same group of the periodic table.  b both gases are in the same period of the periodic table.  c both gases are very reactive.  d gas g has a higher atomic mass than gas h.     24 the diagrams show the structure of two substances used to make electrical conductors.    xy     which statement correctly describes x and y?  a x is a pure metal and y is a compound.  b x is a pure metal and y is an alloy.  c x is a solid and y is a liquid.  d x is harder and stronger than y.    ",
            "10": "10  \u00a9 ucles 2019 0620/13/m/j/19  25 three metals, l, m and n, are added separately to dilute hydrochloric acid and cold water.    the results are shown.    metal reaction with  hydrochloric acid reaction with  cold water  l hydrogen forms no reaction  m hydrogen forms hydrogen forms  n no reaction no reaction    what is the order of reactivity of the metals?     least  reactive  most  reactive  a l n m  b m l n  c n l m  d n m l     26 iron is extracted from its ore in a blast furnace.    hematite, coke, limestone and hot air are added to the furnace.    which explanation is not correct?  a coke burns and produces a high temperature.  b hematite is the ore containing the iron as iron( iii) oxide.  c hot air provides the oxygen for the burning.  d limestone reduces the iron( iii) oxide to iron.      27 aluminium is used to make containers for storing food.    which property makes it suitable for this use?  a conducts heat  b low density  c resists corrosion  d shiny surface     ",
            "11": "11  \u00a9 ucles 2019 0620/13/m/j/19 [turn over  28 water can be treated by filtration then chlorination.    which uses do not need water of this quality?    1 water for cooling in industry  2 water for washing clothes 3 water for drinking    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      29 which statement about acid rain is not correct?  a it causes limestone buildings and statues to erode.  b it is formed from the burning of compounds which contain sulfur.  c it is formed from the combustion of hydrogen as a fuel.  d it is formed from the oxides of nitrogen formed in car engines.      30 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change     ",
            "12": "12  \u00a9 ucles 2019 0620/13/m/j/19  31 which gas is produced when ammonium chloride is warmed with aqueous sodium hydroxide?  a ammonia  b chlorine  c hydrogen  d nitrogen      32 which statement describes a disadvantage of sulfur dioxide?  a it can be used as a bleach when making wood pulp.  b it can be used to kill bacteria in food.  c it can be used to manufacture sulfuric acid.  d it dissolves in water to form acid rain.      33 the diagram represents a lime kiln used to heat limestone to a very high temperature.    air infuel in fuel in air in xwaste gases limestonelime kiln     what leaves the kiln at x?  a calcium carbonate  b calcium hydroxide  c calcium oxide  d calcium sulfate    ",
            "13": "13  \u00a9 ucles 2019 0620/13/m/j/19 [turn over  34 the structures of four compounds are shown.    cc23 1 h hhh hc c hh h hhhhh4 hc c hh hhoh cco oh    which row gives the names of the compounds?     1 2 3 4  a ethene ethane ethanol ethanoic acid  b ethane ethene ethanoic acid ethanol  c ethene ethane ethanoic acid ethanol  d ethane ethene ethanol ethanoic acid     35 which fuel could be gasoline?    is it obtained from petroleum? is it used as fuel for cars?is it used as fuel for cars?no yes no yes ab cdno yes      ",
            "14": "14  \u00a9 ucles 2019 0620/13/m/j/19  36 a hydrocarbon w burns to form carbon dioxide and water.    w decolourises bromine water.    what is the name of w and what is its structure?     name of w structure of w  a ethane ch hhh c h h  b ethane c c hh hh   c ethene ch hhh c h h  d ethene c c hh hh       37 which statements about homologous series are correct?    1 all members have similar chemical properties.  2 all members have the same molecular mass.  3 ethane and ethene are members of the same homologous series.  4 ethane and propane are members of the same homologous series.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     38 which statements about ethanol are correct?    1 it can be made by fermentation.  2 it is an unsaturated compound. 3 it burns in air and can be used as a fuel.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/13/m/j/19 39 which statement about aqueous ethanoic acid is correct?  a it reacts with metal carbonates to form salts, hydrogen and water.  b it reacts with metal oxides to form salts and oxygen.  c it reacts with reactive metals to form salts and hydrogen.  d it turns damp red litmus paper blue.      40 which substances are synthetic polymers?    1 terylene   2 nylon  3 protein  4 poly(ethene)    a 1, 2 and 4 b 1 only c 2 and 3 d 3 and 4    ",
            "16": "16  \u00a9 ucles 2019 0620/13/m/j/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s19_qp_21.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certific ate.  this document consists of 16 printed pages.  ib19 06_0620_21/3rp  \u00a9 ucles 2019 [turn over     *7311411163* cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/21     paper 2  multiple choice (extended)  may/june 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number  on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/21/m/j/19  1 which statement explains why ammonia gas, nh 3, diffuses at a faster rate than  hydrogen chloride gas, hc l ?  a ammonia expands to occupy all of the space available.  b ammonia has a smaller relative molecular mass than hydrogen chloride.  c ammonia is an alkali and hydrogen chloride is an acid.  d ammonia molecules diffuse in all directions at the same time.      2 2.00  g of powdered calcium carbonate is added to 50.0  cm3 of hydrochloric acid.    which apparatus is used to measure the calcium carbonate and the hydrochloric acid?     calcium carbonate hydrochloric acid  a balance burette  b balance thermometer  c pipette burette  d pipette thermometer     3 the measurements from a chromatography ex periment using substance f are shown. the  diagram is not drawn to scale.    100  mm 55 mm90 mm 15 mmsolvent front baselinedistance moved by f     what is the rf value of f?  a 0.55 b 0.61 c 0.90 d 1.64     ",
            "3": "3  \u00a9 ucles 2019 0620/21/m/j/19 [turn over  4 which statement about an atom of fluorine, f19 9, is correct?  a it contains more protons than neutrons.  b it contains a total of 28 protons, neutrons and electrons.  c its isotopes contain different numbers of protons.  d its nucleus contains 9 neutrons.     5 which row describes the formation of single covalent bonds in methane?    a   atoms share a pair of electrons   both atoms gain a  noble gas electronic structure  b   atoms share a pair of electrons   both atoms have the same number  of electrons in their outer shell  c   electrons are transferred from one  atom to another both atoms gain a  noble gas electronic structure  d   electrons are transferred from one  atom to another both atoms have the same number  of electrons in their outer shell      6 which statement describes the structure of an ionic compound?  a it is a giant lattice of oppositely charged ions.  b it is a giant lattice of positive ions in a \u2018sea\u2019 of electrons.  c it is a giant molecule of oppositely charged ions.  d it is a simple molecule of oppositely charged ions.     7 propane burns in oxygen.    c3h8  +  xo2  \u2192  3co 2  +  yh2o    which values of x and y balance the equation?     x y  a 5 4  b 7 4  c 10 8  d 13 8     ",
            "4": "4  \u00a9 ucles 2019 0620/21/m/j/19  8 a tablet contains 0.080  g of ascorbic acid ( mr = 176).    what is the concentration of ascorbic acid when one tablet is dissolved in 200  cm3 of water?  a 9.1 \u00d7 10\u20135  mol  / dm3  b 4.5 \u00d7 10\u20134  mol  / dm3  c 9.1 \u00d7 10\u20132  mol  / dm3  d 2.3 \u00d7 10\u20133  mol  / dm3      9 which statement about the electrolysis of copper( ii) sulfate solution using carbon electrodes is  correct?  a a colourless gas is produced at the anode.  b a colourless gas is produced at the cathode.  c the colour of the electrolyte remains the same.  d the mass of both electrodes remains constant.     10 aluminium metal is extracted from aluminium oxide by electrolysis.    which ionic half-equation describes a reaction that occurs at the named electrode?     ionic half-equation electrode  a 2o2\u2013  \u2192  o 2  +  2e\u2013 anode  b al 3+  +  3e\u2013  \u2192  a l anode  c 2o2\u2013  \u2192  o 2  +  4e\u2013 cathode  d al 3+  +  3e\u2013  \u2192  a l cathode      11 which statement about the hydrogen fuel cell is not correct?  a chemical energy is converte d into electrical energy.  b hydrogen is oxidised.  c the reaction that takes place is endothermic.  d water  is the only product.    ",
            "5": "5  \u00a9 ucles 2019 0620/21/m/j/19 [turn over  12 nitrogen reacts with hydrogen to produce ammonia.    n2  +  3h 2  \u2192  2nh 3    the reaction is exothermic. the bond energies are shown in the table.    bond bond energy  in kj  / mol  n\u2261n 945  h\u2013h 436  n\u2013h 390    what is the energy change for this reaction?  a \u20131473  kj / mol  b \u201387  kj / mol  c 87  kj / mol  d 1473  kj / mol     13 which change in reaction conditions increases both the collision rate and the proportion of  molecules with sufficient energy to react?  a addition of a catalyst  b increasing the concentration of a reactant  c increasing the surface area of a reactant  d increasing the temperature of the reaction      14 when blue-green crystals of nickel( ii) sulfate are heated, water is produced and a yellow solid  remains. when water is added to the yellow solid, the blue-green colour returns.     which process describes these changes?   a combustion  b corrosion  c neutralisation   d reversible reaction    ",
            "6": "6  \u00a9 ucles 2019 0620/21/m/j/19  15 the graph shows how the yield of product in a reversible reaction changes as the temperature  and pressure are changed.    all reactants and products are gases.    reactants    products    yield of product pressure100  \u00b0c300  \u00b0c     which row is correct for this reversible reaction?     side of reaction  with fewer moles forward  reaction  a reactant exothermic  b reactant  endothermic  c product endothermic  d product exothermic     16 which changes represent oxidation?    1 2 i \u2013  \u2192  i2  +  2e\u2013  2 cr( vi)  \u2192  cr(iii)  3 fe( ii)  \u2192  fe( iii)    a 1 and 2 b 1 and 3 c 1 only d 2 only     17 nitrogen( i) oxide, n 2o, nitrogen( ii) oxide, no, and carbon monoxide, co, are all non-metal  oxides.    they do not react with acids or bases.    which statement is correct?  a they are acidic oxides.  b they are amphoteric oxides.  c they are basic oxides.  d they are neutral oxides. ",
            "7": "7  \u00a9 ucles 2019 0620/21/m/j/19 [turn over  18 the positions of elements w, x, y and z in the periodic table are shown.    w xy z    which elements form basic oxides?  a w, x and y b w and x only c y only d z only    19 ethanoic acid is a weak acid.    hydrochloric acid is a strong acid.    which statements are correct?    1 ethanoic acid molecules are partially dissociated into ions.  2 1.0  mol  / dm3 ethanoic acid has a higher ph than 1.0  mol  / dm3 hydrochloric acid.  3 ethanoic acid is always more dilute than hydrochloric acid. 4 ethanoic acid is a proton acceptor.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     20 the properties of an element are shown.    electrical conductivity density reaction with water  high low reacts violently with cold water    which element has these properties?    a c db      ",
            "8": "8  \u00a9 ucles 2019 0620/21/m/j/19  21 which statement about elements in group i and group vii of the periodic table is correct?  a bromine reacts with potassium chloride to produce chlorine.  b iodine is a monatomic non-metal.  c lithium has a higher melting point than potassium.  d sodium is more reactive with water than potassium.      22 which statement about elements in group viii of the periodic table is correct?  a they all have a full outer shell of electrons.  b they all react with group i elements to form ionic compounds.  c they are all diatomic molecules.  d they are all liquids at room temperature.      23 the diagrams show the structure of two substances used to make electrical conductors.    xy     which statement correctly describes x and y?  a x is a pure metal and y is a compound.  b x is a pure metal and y is an alloy.  c x is a solid and y is a liquid.  d x is harder and stronger than y.    ",
            "9": "9  \u00a9 ucles 2019 0620/21/m/j/19 [turn over  24 three metal compounds, p, q and r, are heated using a bunsen burner.    the results are shown.    p colourless gas produced, which relights a glowing splint  q colourless gas produced, which turns limewater milky r no reaction    which row shows the identity of p, q and r?     p q r  a magnesium carbonate potassium carbonate potassium nitrate  b magnesium carbonate potassium nitrate potassium carbonate  c potassium nitrate magnesium carbonate potassium carbonate  d potassium nitrate potassium carbonate magnesium carbonate      25 zinc is extracted from its ore, zinc blende, using two chemical reactions.    1 2zns  +  3o 2  \u2192  2zno  +  2so 2  2 2zno  +  c  \u2192  2zn  +  co 2    which substance is reduced in reactions 1 and 2?     reaction 1 reaction 2  a o2 c  b o2 zno  c zns c  d zns zno     ",
            "10": "10  \u00a9 ucles 2019 0620/21/m/j/19  26 four metals, zinc, m, copper and magnesium, are reacted with aqueous solutions of their  nitrates.    the results are shown.    metal magnesium  nitrate m  nitrate copper  nitrate zinc  nitrate   magnesium  \u0016 \u0016 \u0016 key  zinc \u001a \u0016 \u0016  \u0016= reacts  m \u001a  \u0016 \u001a \u001a= no reaction  copper \u001a \u001a  \u001a     what is the order of reactivity of these four metals starting with the most reactive?  a copper  \u2192  zinc  \u2192  m  \u2192  magnesium  b copper  \u2192  m  \u2192  zinc  \u2192  magnesium  c magnesium  \u2192  m  \u2192  zinc  \u2192  copper  d magnesium  \u2192  zinc  \u2192  m  \u2192  copper      27 why is aluminium used to make containers for storing food?  a it conducts electricity.  b it has a high melting point.  c it is resistant to corrosion.  d it is strong.     28 water can be treated by filtration then chlorination.    which uses do not need water of this quality?    1 water for cooling in industry  2 water for washing clothes 3 water for drinking    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    ",
            "11": "11  \u00a9 ucles 2019 0620/21/m/j/19 [turn over  29 oxides of nitrogen are formed in car engines and are a source of air pollution.    to decrease this pollution, catalytic converters are fitted to car exhausts.    what happens to the oxides of nitrogen in the catalytic converter?  a combustion  b cracking  c oxidation  d reduction     30 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change     31 ammonia is manufactured by the haber process.    n 2(g)  +  3h 2(g)    2nh 3(g)    the forward reaction is exothermic.    which conditions maximise the yield of ammonia?     pressure temperature  a high high  b high low  c low high  d low low ",
            "12": "12  \u00a9 ucles 2019 0620/21/m/j/19  32 the carbon cycle is shown.    atmospheric carbon dioxide dead organic mattergreen plants animalsy death and excretionx zdecompositionrespiration     which row describes processes x, y and z?     x y z  a respiration combustion photosynthesis  b respiration photosynthesis combustion  c photosynthesis combustion respiration  d photosynthesis respiration combustion      33 which row shows the conditions used in the contact process?     temperature  / \u00b0c pressure  / atm catalyst  a 25 2 iron  b 25 200 iron  c 450 2 vanadium( v) oxide  d 450 200 vanadium( v) oxide       ",
            "13": "13  \u00a9 ucles 2019 0620/21/m/j/19 [turn over  34 the diagram represents a lime kiln used to heat limestone to a very high temperature.    air infuel in fuel in air in xwaste gases limestonelime kiln     what leaves the kiln at x?  a calcium carbonate  b calcium hydroxide  c calcium oxide  d calcium sulfate     35 which fuel could be gasoline?    is it obtained from petroleum? is it used as fuel for cars?is it used as fuel for cars?no yes no yes ab cdno yes      ",
            "14": "14  \u00a9 ucles 2019 0620/21/m/j/19  36 why is ethanol a member of the homologous series of alcohols but propane is not?  a ethanol has two carbon atoms per molecule but propane has three.  b ethanol can be made from ethene but propane is obtained from petroleum.  c ethanol is a liquid but propane is a gas.  d ethanol contains the same functional group as other alcohols but propane does not.      37 chlorine reacts with methane.    which statements are correct?    1 the reaction takes place in the dark.  2 the reaction of chlorine with methane forms chloromethane. 3 chloromethane reacts with chlorine to produce dichloromethane. 4 the reaction of chlorine with methane is an addition reaction.    a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4     38 which statements about aqueous ethanoic acid are correct?    1 ethanoic acid contains the functional group \u2013cooh.  2 ethanoic acid reacts with carbonates to produce hydrogen.  3 ethanoic acid turns universal indicator paper blue. 4 ethanoic acid has a ph lower than ph 7.    a 1 and 2 b 1 and 3 c 1 and 4 d 2 and 4      39 the structure of an ester is shown.    c och2ch2ch3o ch3     what is the name of the ester?  a ethyl propanoate  b methyl propanoate  c propyl ethanoate  d propyl methanoate     ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the camb ridge assessment group.  cambridge assessment is the brand name  of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/21/m/j/19  40 the structure of a polymer is shown.    o o o o    which type of polymer is shown and by which process is it formed?     type of polymer formed by  a carbohydrate addition polymerisation  b carbohydrate condensation polymerisation  c polyester addition polymerisation  d polyester condensation polymerisation     ",
            "16": "16  \u00a9 ucles 2019 0620/21/m/j/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s19_qp_22.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certific ate.  this document consists of 17 printed pages and 3 blank pages.  ib19 06_0620_22/3rp  \u00a9 ucles 2019   [turn over     *6592304997 * cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2  multiple choice (extended)  may/june 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 20.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/22/m/j/19  1 the apparatus shown is set up. after 20 minutes a white ring of ammonium chloride is seen at  position y.    cotton wool soaked in concentrated ammonia solutioncotton wool soaked in concentrated hydrochloric acid y white ring of ammonium chloride    which statement about the molecules of ammonia and hydrogen chloride is correct?  a molecules in ammonia have a larger mr than molecules of hydrogen chloride and so they  move more slowly.  b molecules in ammonia have a larger mr than molecules of hydrogen chloride and so they  move more quickly.  c molecules in ammonia have a smaller mr than molecules of hydrogen chloride and so they  move more slowly.  d molecules in ammonia have a smaller mr than molecules of hydrogen chloride and so they  move more quickly.      2 a student measures 25.00  cm3 of dilute hydrochloric acid accurately.    which apparatus is most suitable?  a beaker  b measuring cylinder  c burette  d dropping pipette     ",
            "3": "3  \u00a9 ucles 2019 0620/22/m/j/19 [turn over  3 the chromatogram of solutions of two metal ions, p and q, is shown.    p q baselinesolvent front     p is coloured. a locating agent is used to find the position of q.    the rf value of each solution is calculated.    p is a ..1.. element and has an rf value ..2.. than that  of q.    which words complete gaps 1 and 2?     1 2  a non-transition greater  b non-transition smaller  c transition greater  d transition smaller      4 what is an isotope of e31 15?  a e31 14 b e33 15 c e31 16 d e3316      5 which row describes the formation of single covalent bonds in methane?    a   atoms share a pair of electrons   both atoms gain a  noble gas electronic structure  b   atoms share a pair of electrons   both atoms have the same number  of electrons in their outer shell  c   electrons are transferred from one  atom to another both atoms gain a  noble gas electronic structure  d   electrons are transferred from one  atom to another both atoms have the same number  of electrons in their outer shell     ",
            "4": "4  \u00a9 ucles 2019 0620/22/m/j/19  6 which statement describes the structure of an ionic compound?  a it is a giant lattice of oppositely charged ions.  b it is a giant lattice of positive ions in a \u2018sea\u2019 of electrons.  c it is a giant molecule of oppositely charged ions.  d it is a simple molecule of oppositely charged ions.      7 calcium metal reacts with water to form a solution of calcium hydroxide and hydrogen gas.    which equation is correct?  a ca(s)  +  h 2o(aq)  \u2192  caoh(aq)  +  h(g)  b ca(s)  +  2h 2o(aq)  \u2192  ca(oh) 2(s)  +  2h 2(g)  c ca(s)  +  2h 2o(l)  \u2192  ca(oh) 2(aq)  +  h 2(g)  d ca(s)  +  h 2o(l)  \u2192  caoh(l)  +  h(g)     8 25.0  cm3 of 0.100  mol  / dm3 aqueous sodium hydroxide is neutralised by 24.6  cm3 of dilute  sulfuric acid.    what is the concentration of the dilute sulfuric acid?  a 0.0508  mol  / dm3  b 0.0984  mol  / dm3  c 0.102  mol  / dm3  d 0.203  mol  / dm3    ",
            "5": "5  \u00a9 ucles 2019 0620/22/m/j/19 [turn over  9 the diagram shows the electrolysis of an aqueous solution of x using inert electrodes.    aqueous solution of x+ \u2013power supply     hydrogen is produced at the cathode and chlorine is produced at the anode.    what is x?  a concentrated copper( ii) chloride solution  b concentrated hydrochloric acid  c dilute hydrochloric acid  d dilute sodium chloride solution     10 aluminium is extracted by electrolysis as shown.    \u2013 \u2013 + +graphite anode graphite cathodesteel case aluminium oxide dissolved in molten cryolite molten aluminium    which row shows the ionic half-equations at the cathode and the anode?     cathode anode  a al 3+  \u2192  a l  +  3e\u2013 2o2\u2013  \u2192  o 2  +  4e\u2013  b al 3+  \u2192  a l  +  3e\u2013 2o2\u2013  +  4e\u2013  \u2192  o 2  c al 3+  +  3e\u2013  \u2192  a l 2o2\u2013  \u2192  o 2  +  4e\u2013  d al 3+  +  3e\u2013  \u2192  a l 2o2\u2013  +  4e\u2013  \u2192  o 2     ",
            "6": "6  \u00a9 ucles 2019 0620/22/m/j/19  11 fuel cells are used as energy sources in cars.    which row gives a fuel used in a fuel cell and the products formed?     fuel in a fuel cell products formed  a hydrogen carbon dioxide and water  b hydrogen water only  c petrol carbon dioxide and water  d petrol water only     12 two elements, x and y, react together to form a covalent molecule as shown.    the reaction is exothermic.    x 2(g)  +  y 2(g)  \u2192  2xy(g)    the bond energies are shown in the table.    bond bond energy in  kj / mol  x\u2013x 436  y\u2013y 242  x\u2013y 431    what is the energy change for the reaction?  a +184  kj / mol b \u2013184  kj / mol c +247  kj / mol d \u2013247  kj / mol      13 which change in reaction conditions increases both the collision rate and the proportion of  molecules with sufficient energy to react?  a addition of a catalyst  b increasing the concentration of a reactant  c increasing the surface area of a reactant  d increasing the temperature of the reaction     ",
            "7": "7  \u00a9 ucles 2019 0620/22/m/j/19 [turn over  14 when blue-green crystals of nickel( ii) sulfate are heated, water is produced and a yellow solid  remains. when water is added to the yellow solid, the blue-green colour returns.     which process describes these changes?   a combustion  b corrosion  c neutralisation   d reversible reaction    15 the equation for the manufacture of ethanol is shown.    c 2h4(g)  +  h 2o(g)    c2h5oh(g)   ethene steam ethanol    what is the effect of doubling the pressure on this reaction?  a decreases the rate of formation of ethanol  b increases the yield of ethene  c decreases the rate of formation of ethene  d increases the yield of ethanol    16 the ionic equation for the reaction of aqueous potassium bromide with chlorine gas is shown.    2br  \u2013  +  c l 2  \u2192  br 2  +  2c l \u2013    which statement is correct?  a bromide ions are oxidised by gaining electrons.  b bromide ions are oxidised by losing electrons.  c chlorine is oxidised by gaining electrons.  d chlorine is oxidised by losing electrons.    17 which type of oxide are carbon monoxide and aluminium oxide?     carbon monoxide aluminium oxide  a acidic amphoteric  b acidic basic  c neutral amphoteric  d neutral basic     ",
            "8": "8  \u00a9 ucles 2019 0620/22/m/j/19  18 the positions of elements w, x, y and z in the periodic table are shown.    w xy z    which elements form basic oxides?  a w, x and y b w and x only c y only d z only    19 which row shows the difference between a weak acid and a strong acid?     weak acid strong acid  a fully ionised partially ionised  b concentrated dilute  c dilute concentrated  d partially ionised fully ionised     20 part of the periodic table is shown.    yzx     which row describes the properties of x, y and z?     good conductor  of electricity high melting  point  a x z  b y z and x  c y and z z  d z and x x     ",
            "9": "9  \u00a9 ucles 2019 0620/22/m/j/19 [turn over  21 the melting points and boiling points of the elements of group i of the periodic table are shown.    element melting point  / \u00b0c boiling point  / \u00b0c  lithium 181 1330  sodium 98 883  potassium 63 759  rubidium 39 688  caesium 28 671    which pair of elements are liquid at 800  \u00b0c?  a caesium and rubidium  b potassium and sodium  c lithium and sodium  d potassium and caesium     22 the electronic structures of helium, neon and argon are shown.    he ne ar     which row describes these gases?     reactivity form of the gas electronic structure  a reactive monoatomic incomplete outer shell of electrons  b unreactive diatomic complete outer shell of electrons  c unreactive diatomic incomplete outer shell of electrons  d unreactive monoatomic complete outer shell of electrons     ",
            "10": "10  \u00a9 ucles 2019 0620/22/m/j/19  23 the diagrams show the structure of two substances used to make electrical conductors.    xy     which statement correctly describes x and y?  a x is a pure metal and y is a compound.  b x is a pure metal and y is an alloy.  c x is a solid and y is a liquid.  d x is harder and stronger than y.     24 a student heated the carbonates and nitrates of sodium and copper.    the results are shown.     compound heated gases released solid formed  1 sodium carbonate carbon monoxide sodium oxide  2 copper( ii) carbonate carbon dioxide copper  3 sodium nitrate oxygen only sodium nitrite  4 copper( ii) nitrate nitrogen dioxide and oxygen copper( ii) oxide    which rows describe the correct results?  a 1 and 3 b 2 and 3 c 3 and 4 d 4 only    25 zinc is extracted from its ore, zinc blende, using two chemical reactions.    1 2zns  +  3o 2  \u2192  2zno  +  2so 2  2 2zno  +  c  \u2192  2zn  +  co 2    which substance is reduced in reactions 1 and 2?     reaction 1 reaction 2  a o2 c  b o2 zno  c zns c  d zns zno     ",
            "11": "11  \u00a9 ucles 2019 0620/22/m/j/19 [turn over  26 four metals, zinc, m, copper and magnesium, are reacted with aqueous solutions of their  nitrates.    the results are shown.    metal magnesium  nitrate m  nitrate copper  nitrate zinc  nitrate   magnesium  \u0016 \u0016 \u0016 key  zinc \u001a \u0016 \u0016  \u0016= reacts  m \u001a  \u0016 \u001a \u001a= no reaction  copper \u001a \u001a  \u001a     what is the order of reactivity of these four metals starting with the most reactive?  a copper  \u2192  zinc  \u2192  m  \u2192  magnesium  b copper  \u2192  m  \u2192  zinc  \u2192  magnesium  c magnesium  \u2192  m  \u2192  zinc  \u2192  copper  d magnesium  \u2192  zinc  \u2192  m  \u2192  copper      27 which property of aluminium makes it useful in the manufacture of aircraft?  a conducts electricity  b high boiling point  c low density  d silver colour     28 the exhaust gases from cars contain oxides of nitrogen.    how are these oxides of nitrogen formed?  a nitrogen and oxygen from the air react together at the high temperatures in the engine.  b nitrogen and oxygen from the petrol react together in the car exhaust.  c nitrogen from the petrol reacts with oxygen at the high temperatures in the engine.  d nitrogen reacts with oxygen from the air in the catalytic converter.    ",
            "12": "12  \u00a9 ucles 2019 0620/22/m/j/19  29 water can be treated by filtration then chlorination.    which uses do not need water of this quality?    1 water for cooling in industry  2 water for washing clothes 3 water for drinking    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      30 some of the processes involved in the carbon cycle are shown.    1 glucose  +  oxygen  \u2192  carbon dioxide  +  water  2 carbon dioxide  +  water  \u2192  glucose  +  oxygen  3 methane  +  oxygen  \u2192  carbon dioxide  +  water    what are the names of these processes?     1 2 3  a combustion respiration photosynthesis  b photosynthesis combustion respiration  c respiration combustion photosynthesis  d respiration photosynthesis combustion      31 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change ",
            "13": "13  \u00a9 ucles 2019 0620/22/m/j/19 [turn over  32 ammonia is produced in the haber process.    the equation for the reaction is shown.    3h2(g)  +  n 2(g)    2nh 3(g)    the forward reaction is exothermic.    which conditions of temperature and pressure produce the highest yield of ammonia?     temperature pressure  a high high  b high low  c low high  d low low     33 which row shows the conditions used in the contact process?     temperature  /  \u00b0c pressure  / atm catalyst  a 25 2 iron  b 25 200 iron  c 450 2 vanadium( v) oxide  d 450 200 vanadium( v) oxide     ",
            "14": "14  \u00a9 ucles 2019 0620/22/m/j/19  34 the diagram represents a lime kiln used to heat limestone to a very high temperature.    air infuel in fuel in air in xwaste gases limestonelime kiln     what leaves the kiln at x?  a calcium carbonate  b calcium hydroxide  c calcium oxide  d calcium sulfate     35 which fuel could be gasoline?    is it obtained from petroleum? is it used as fuel for cars?is it used as fuel for cars?no yes no yes ab cdno yes      ",
            "15": "15  \u00a9 ucles 2019 0620/22/m/j/19 [turn over  36 which statement about homologous series is not correct?  a all homologous series are hydrocarbons.  b members of a homologous series have the same functional group.  c members of a homologous series have similar chemical properties.  d the alkanes are an example of a homologous series.      37 in bright sunlight, ethane and chlorine combine in substitution reactions.    which compound is not formed in these reactions?  a c 2h3cl b c 2h5cl c c 2h4cl 2 d hc l     38 what are the properties of aqueous ethanoic acid?     decolourises  bromine water reacts with  calcium carbonate to make carbon dioxide turns damp red   litmus blue  a \u0016 \u0016 \u001a  b \u0016 \u001a \u0016  c \u001a \u0016 \u001a  d \u001a \u001a \u0016     39 the structures of four molecules are shown.    co ohoohh1 c ohh hh2 c ohh hch hch hh3 ch hch hc h4     which molecules react together to form the ester propyl methanoate?  a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4    ",
            "16": "16  \u00a9 ucles 2019 0620/22/m/j/19  40 but-1-ene has the structure ch 3ch 2ch=ch 2.    what is the structure of poly(but-1-ene)?    ch hch hcha hch hncch3 hcch3 hc n nc hchd ch hcch2ch3 ch2ch3ch2ch3 hb n      ",
            "17": "17    blank page   \u00a9 ucles 2019 0620/22/m/j/19 ",
            "18": "18    blank page   \u00a9 ucles 2019 0620/22/m/j/19  ",
            "19": "19    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/22/m/j/19  ",
            "20": "20    \u00a9 ucles 2019 0620/22/m/j/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s19_qp_23.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certific ate.  this document consists of 15 printed pages and 1 blank page.  ib19 06_0620_23/4rp  \u00a9 ucles 2019 [turn over     *2518966734* cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/23     paper 2  multiple choice (extended)  may/june 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number  on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/23/m/j/19  1 hydrogen chloride gas ( mr = 36.5) is released at p in the apparatus shown.    the universal indicator paper turns red after 38  s.    p universal indicator paper    the experiment is repeated using sulfur dioxide ( mr = 64).    what is the result for sulfur dioxide?     universal indicator  turns time for universal indicator  to change colour  / s  a blue 26  b blue 51  c red 26  d red 51      2 which piece of apparatus is used to measure 24.8  cm3 of gas produced during a reaction?  a beaker  b conical flask  c measuring cylinder  d pipette     3 r f values are used to identify unknown substances using paper chromatography.    which statements about rf values are correct?    1 rf values are always less than 1.0.  2 rf value = distance travelled by solvent \u00f7 distance travelled by unknown substance.  3 the higher the rf value, the further the unknown substance travels.  4 rf values are not affected by the solubility of the unknown substance.    a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4    ",
            "3": "3  \u00a9 ucles 2019 0620/23/m/j/19 [turn over  4 the structure of an atom is shown.    7p 8nkey = electron = neutronn = protonp     which element is the atom an isotope of?  a nitrogen  b oxygen  c phosphorus  d titanium    5 which row describes the formation of single covalent bonds in methane?    a   atoms share a pair of electrons   both atoms gain a  noble gas electronic structure  b   atoms share a pair of electrons   both atoms have the same number  of electrons in their outer shell  c   electrons are transferred from one  atom to another both atoms gain a  noble gas electronic structure  d   electrons are transferred from one  atom to another both atoms have the same number  of electrons in their outer shell     6 which statement describes the structure of an ionic compound?  a it is a giant lattice of oppositely charged ions.  b it is a giant lattice of positive ions in a \u2018sea\u2019 of electrons.  c it is a giant molecule of oppositely charged ions.  d it is a simple molecule of oppositely charged ions.     7 when propane burns in air, carbon dioxide and water are formed.    what is the chemical equation for this reaction?  a c 3h8  +  2o 2  \u2192  co 2  +  2h 2o  b c 3h8  +  3o 2  \u2192  3co 2  +  h 2o  c c 3h8  +  4o 2  \u2192  3co 2  +  4h 2o  d c 3h8  +  5o 2  \u2192  3co 2  +  4h 2o ",
            "4": "4  \u00a9 ucles 2019 0620/23/m/j/19  8 what is the concentration of a solution that contains 25.0  g naoh in 500  cm3 of water?  a 0.125  mol  / dm3  b 0.800  mol  / dm3  c 1.25  mol  / dm3  d 3.20  mol  / dm3      9 an aqueous solution of copper( ii) sulfate was electrolysed using copper electrodes.    copper anodecopper cathode aqueous copper( ii) sulfatepower supply + \u2013     which equation for the reaction at the anode is correct?  a cu  \u2192  cu2+  +  2e\u2013  b cu  +  2e\u2013  \u2192  cu2+  c cu2+  \u2192  cu  +  2e\u2013  d cu2+  +  2e\u2013  \u2192  cu     10 in the manufacture of aluminium by electrolysis , aluminium oxide is dissolved in molten cryolite.    why is cryolite used?  a it lowers the melting point of the aluminium.  b it makes the aluminium a better conductor.  c it removes impurities from the aluminium.  d the mixture has a lower melting point than pure aluminium oxide.      11 which statement about a fuel cell in a car is correct?  a the fuel cell produces heat, which powers the car.  b the fuel cell is supplied with hydrogen directly from the air.  c the only emission from a fuel cell is nitrogen gas, which is non-polluting.  d the fuel cell produces electricity,  which powers an electric motor. ",
            "5": "5  \u00a9 ucles 2019 0620/23/m/j/19 [turn over  12 methane burns in oxygen to form carbon dioxide and water.    ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(l)    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013h 410  c\u2013o 360  c=o 805  o\u2013h 460  o\u2013o 146  o=o 496    what is the energy change for this reaction?  a \u2013818  kj / mol b \u2013102  kj / mol c +102  kj / mol d +818  kj / mol    13 which change in reaction conditions increases both the collision rate and the proportion of  molecules with sufficient energy to react?  a addition of a catalyst  b increasing the concentration of a reactant  c increasing the surface area of a reactant  d increasing the temperature of the reaction     14 when blue-green crystals of nickel( ii) sulfate are heated, water is produced and a yellow solid  remains. when water is added to the yellow solid, the blue-green colour returns.     which process describes these changes?   a combustion  b corrosion  c neutralisation   d reversible reaction    ",
            "6": "6  \u00a9 ucles 2019 0620/23/m/j/19  15 a reaction between nitrogen and oxygen is shown. the forward reaction is endothermic.    n2(g)  +  o 2(g)    2no(g)    which change increases the equilibrium yield of nitrogen monoxide, no?  a decreasing the pressure  b decreasing the temperature  c increasing the pressure  d increasing the temperature     16 which changes represent reduction?    1 c l  2  +  2e\u2013  \u2192  2c l \u2013  2 mn( vii)  \u2192  mn( ii)  3 sulfate( iv)  \u2192  sulfate( vi)    a 1 and 2 b 1 and 3 c 1 only d 2 only      17 which statement about carbon monoxide and aluminium oxide is correct?  a carbon monoxide and aluminium oxide are both amphoteric.  b carbon monoxide and aluminium oxide are both neutral.  c carbon monoxide is amphoteric but aluminium oxide is neutral.  d carbon monoxide is neutral but aluminium oxide is amphoteric.      18 the positions of elements w, x, y and z in the periodic table are shown.    w xy z    which elements form basic oxides?  a w, x and y b w and x only c y only d z only    ",
            "7": "7  \u00a9 ucles 2019 0620/23/m/j/19 [turn over  19 solutions of acid r and acid s have the same concentration.    the same volume of each acid at the same temperature is reacted with the same mass of magnesium ribbon.    the volume of hydrogen produced is measured.    the results are shown.    00volume of hydrogen timer s     which statement about the reactions is correct?  a acid s reacts faster than acid r.  b the final volume of hydrogen produced in each reaction is different.  c acid r is a stronger acid than acid s.  d acid s is a stronger acid than acid r.     20 part of the periodic table is shown.    xy zw     which row describes w, x, y and z?     metal non-metal  a x w, y and z  b x and y w and z  c w and z x and y  d w, y and z x     ",
            "8": "8  \u00a9 ucles 2019 0620/23/m/j/19  21 which statement about the properties of elements in group i and in group vii is correct?  a bromine displaces iodine from an aqueous solution of potassium iodide.  b chlorine, bromine and iodine are diatomic gases at room temperature.  c lithium, sodium and potassium are soft non-metals.  d lithium, sodium and potassium have an increasin g number of electrons in their outer shells.      22 gas g has 10 electrons. gas h has eight more electrons than gas g. both gases are  monoatomic.    which statement about g and h is correct?  a both gases are in the same group of the periodic table.  b both gases are in the same period of the periodic table.  c both gases are very reactive.  d gas g has a higher atomic mass than gas h.    23 the diagrams show the structure of two substances used to make electrical conductors.    xy     which statement correctly describes x and y?  a x is a pure metal and y is a compound.  b x is a pure metal and y is an alloy.  c x is a solid and y is a liquid.  d x is harder and stronger than y.    24 magnesium nitrate, magnesium hydroxide and magnesium carbonate all decompose when  heated.    which statement about these decomposition reactions is correct?  a magnesium carbonate decomposes to release carbon dioxide and oxygen.  b magnesium hydroxide decomposes to release hydrogen and oxygen.  c magnesium hydroxide decomposes to release water vapour.  d magnesium nitrate decomposes to release oxygen only.    ",
            "9": "9  \u00a9 ucles 2019 0620/23/m/j/19 [turn over  25 zinc is extracted from its ore, zinc blende, using two chemical reactions.    1 2zns  +  3o 2  \u2192  2zno  +  2so 2  2 2zno  +  c  \u2192  2zn  +  co 2    which substance is reduced in reactions 1 and 2?     reaction 1 reaction 2  a o2 c  b o2 zno  c zns c  d zns zno     26 four metals, zinc, m, copper and magnesium, are reacted with aqueous solutions of their  nitrates.    the results are shown.    metal magnesium  nitrate m  nitrate copper  nitrate zinc  nitrate   magnesium  \u0016 \u0016 \u0016 key  zinc \u001a \u0016 \u0016  \u0016= reacts  m \u001a  \u0016 \u001a \u001a= no reaction  copper \u001a \u001a  \u001a     what is the order of reactivity of these four metals starting with the most reactive?  a copper  \u2192  zinc  \u2192  m  \u2192  magnesium  b copper  \u2192  m  \u2192  zinc  \u2192  magnesium  c magnesium  \u2192  m  \u2192  zinc  \u2192  copper  d magnesium  \u2192  zinc  \u2192  m  \u2192  copper    27 aluminium is used to make containers for storing food.    which property makes it suitable for this use?  a conducts heat  b low density  c resists corrosion  d shiny surface    ",
            "10": "10  \u00a9 ucles 2019 0620/23/m/j/19  28 water can be treated by filtration then chlorination.    which uses do not need water of this quality?    1 water for cooling in industry  2 water for washing clothes 3 water for drinking    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      29 catalytic converters in car exhausts change polluting gases into non-polluting gases.    which statements about oxides of nitrogen and car engines are correct?    1 the nitrogen in oxides of nitrogen comes from compounds in petrol.  2 the oxygen in oxides of nitrogen comes from the air in the car engine. 3 catalytic converters convert oxides of nitrogen into nitrogen and other gases.    a 1 and 2 b 2 and 3 c 2 only d 3 only     30 the diagram shows an experiment to investigate how paint affects the rusting of iron.    airpq wate riron painted iron     what happens to the water level in tubes p and q?     tube p tube q  a falls rises  b no change rises  c rises falls  d rises no change     ",
            "11": "11  \u00a9 ucles 2019 0620/23/m/j/19 [turn over  31 which row about the carbon cycle is correct?     process for removing  carbon dioxide from  the atmosphere process for returning  carbon dioxide to  the atmosphere  a photosynthesis combustion of hydrocarbons  b photosynthesis cracking of hydrocarbons  c respiration combustion of hydrocarbons  d respiration cracking of hydrocarbons     32 ammonia is manufactured in an exothermic reaction.    n 2(g)  +  3h 2(g)    2nh 3(g)    what is the effect of lowering the temperature on the rate of formation and equilibrium yield of ammonia?     rate of formation equilibrium yield  a decreases decreases  b decreases increases  c increases decreases  d increases increases     33 which row shows the conditions used in the contact process?     temperature  /  \u00b0c pressure  / atm catalyst  a 25 2 iron  b 25 200 iron  c 450 2 vanadium( v) oxide  d 450 200 vanadium( v) oxide     ",
            "12": "12  \u00a9 ucles 2019 0620/23/m/j/19  34 the diagram represents a lime kiln used to heat limestone to a very high temperature.    air infuel in fuel in air in xwaste gases limestonelime kiln     what leaves the kiln at x?  a calcium carbonate  b calcium hydroxide  c calcium oxide  d calcium sulfate     35 which fuel could be gasoline?    is it obtained from petroleum? is it used as fuel for cars?is it used as fuel for cars?no yes no yes ab cdno yes      ",
            "13": "13  \u00a9 ucles 2019 0620/23/m/j/19 [turn over  36 which statements about homologous series are correct?    1 all members have similar chemical properties.  2 all members have the same molecular mass.  3 ethane and ethene are members of the same homologous series.  4 ethane and propane are members of the same homologous series.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     37 which type of reaction takes place when methane reacts with chlorine in the presence of  ultraviolet light?  a addition  b cracking  c polymerisation  d substitution      38 which statement about aqueous ethanoic acid is correct?  a it reacts with metal carbonates to form salts, hydrogen and water.  b it reacts with metal oxides to form salts and oxygen.  c it reacts with reactive metals to form salts and hydrogen.  d it turns damp red litmus paper blue.      39 the structure of ester w is shown.    c hh hco o ch hh     which row gives the names of ester w and the carboxylic acid and alcohol from which it is made?     name of ester w carboxylic acid alcohol  a ethyl methanoate ethanoic acid methanol  b ethyl methanoate methanoic acid ethanol  c methyl ethanoate ethanoic acid methanol  d methyl ethanoate methanoic acid ethanol     ",
            "14": "14  \u00a9 ucles 2019 0620/23/m/j/19  40 a section of a polymer is shown.    ch ho co o ch hch hco ch hch ho co o ch hch hco ch h    how many different types of monomer units formed this section of polymer?  a 1 b 2 c 3 d 4     ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the camb ridge assessment group.  cambridge assessment is the brand name  of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/23/m/j/19  blank page  ",
            "16": "16  \u00a9 ucles 2019 0620/23/m/j/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s19_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 20.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31 paper 3  theory (core) may/june 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 18 printed pages and 2 blank pages. [turn overib19 06_0620_31/2rp\u00a9 ucles 2019 *7118832773* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/31/m/j/19 \u00a9 ucles 2019 1\t\tthe\tdiagrams\tshow\tpart\tof\tthe\tstructures\tof\tfive\tsubstances,\ta,\tb,\tc,\td\tand\te. li+cl \u2013li+cl \u2013 cl \u2013li+li+cl \u2013 li+cl \u2013li+cl \u2013 cl \u2013li+li+cl \u2013 cucucucu cucucucu cucucucu cucucucuhe hehehe he he ab dec n nn n n nn nn n  (a)\t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\tstructures. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall.  (i)  which two\tof\tthese\tstructures,\t a,\tb,\tc,\td or e,\tare\tcovalently\tbonded? \t ..\tand\t ...  [2]  (ii)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tis\ta\tdiatomic\tmolecule?   ...   [1]  (iii)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tis\ta\tcompound?   ...   [1]  (iv)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tis\tvery\tsoluble\tin\twater?     ...   [1]  (v)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tis\tused\tin\tcutting\ttools?   ...   [1]  (vi)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tis\tused\tin\telectrical\twiring?   ...   [1]",
            "3": "3 0620/31/m/j/19 \u00a9 ucles 2019 [turn over  (b)\t\tsubstance\tb\tis\tan\telement. \t\twhat\tis\tmeant\tby\tthe\tterm\telement \t?      ..   [1] \t [total:\t8]",
            "4": "4 0620/31/m/j/19 \u00a9 ucles 2019 2\t\tthis\tquestion\tis\tabout\tiron\tand\tiron\tcompounds.  (a)\t\tname\tthe\tmain\tore\tof\tiron.   ..   [1]  (b)\t\tin\ta\tblast\tfurnace\tused\tfor\tthe\textraction\t of\tiron,\tcarbon\treacts\twith\toxygen\tfrom\tthe\tair\tto\tform\t carbon\tmonoxide. \t\tcomplete\tthe\tchemical\tequation\tfor\tthis\treaction. c  +  .    2co  [2]  (c)\t\tin\tthe\thotter\tparts\tof\tthe\tfurnace,\tcarbon\treacts\twith\tthe\tiron( iii)\toxide\tpresent\tin\tthe\tiron\tore. 3c  +  fe2o3    3co  +  2fe \t\thow\tdoes\tthis\tequation\tshow\tthat\tcarbon\tis\toxidised?      ..   [1]  (d)\t\tlimestone\t is\tadded\tto\tthe\tblast\tfurnace.\tthe\tlimestone\t is\tconverted\t into\tcalcium\toxide\tand\t carbon\tdioxide.\t the\treaction\tis\tendothermic.  heat caco3    cao  +  co2  (i)\t\twhat\ttype\tof\tchemical\treaction\tis\tthis?   ...   [1]  (ii)\t\twhat\ttype\tof\toxide\tis\tcalcium\toxide? \t \tgive\ta\treason\tfor\tyour\tanswer.   .   ...   [2]  (e)\t\tiron\tis\ta\tmetal. \t\tgive\tthree\tphysical\tproperties\tthat\tare\tcharacteristic\tof\tmetals.  1  .  2  .  3  .  [3]",
            "5": "5 0620/31/m/j/19 \u00a9 ucles 2019 [turn over  (f)\t\tthe\tstructure\tof\ta\tcompound\tof\tiron\tis\tshown. c o c oo c co oc co occo oc fe fe \t\tdeduce\tthe\tmolecular\t formula\tof\tthis\tcompound\t to\tshow\tthe\tnumber\tof\tiron,\tcarbon\tand\t oxygen\tatoms.   ..   [1] \t [total:\t11]",
            "6": "6 0620/31/m/j/19 \u00a9 ucles 2019 3 (a)\t\tthe\ttable\tshows\tthe\tpercentage\tby\tmass\tof\tthe\telements\ton\tearth\tand\tin\tthe\tuniverse. elementpercentage\tby mass\ton\tearthpercentage\tby\tmass in\tthe\tuniverse helium 0.0 21.0 hydrogen 0.1 76.0 iron 35.0 1.0 magnesium 14.0 0.1 oxygen 29.0 0.8 silicon 14.0 0.1 sulfur 2.9 0.1 other\telements 0.9 total 100.0 100.0 \t\tanswer\tthese\tquestions\tusing\tonly\tthe\tinformation\tin\tthe\ttable.\t  (i)\t\tdeduce\tthe \tpercentage\tby\tmass\tof\tother\telements\tpresent\ton\tearth.  .. %  [1]  (ii)\t\twhich\tnon-metallic\telement\tis\tpresent\ton\tearth\tin\tthe\tgreatest\tpercentage\tby\tmass?   ...   [1]  (iii)\t\tgive\t two\tmajor\tdifferences\t in\tthe\tpercentage\t by\tmass\tof\tthe\telements\ton\tearth\tand\tin\tthe\t universe.  1  ..   .  2  ..   .  [2]  (b)\t\tcomplete\tthe\tdiagram\tto\tshow\tthe\telectron\tarrangement\tin\tan\toxygen\tatom.  [1]",
            "7": "7 0620/31/m/j/19 \u00a9 ucles 2019 [turn over  (c)\t\thelium,\tneon\tand\targon\tare\tnoble\tgases.  (i)\t\texplain,\tin\t terms\tof\tthe\telectronic\tstructure,\twhy\tneon\tis\tunreactive.   .   ...   [1]  (ii)  state one\tuse\tof\targon.   ...   [1] \t [total:\t7]",
            "8": "8 0620/31/m/j/19 \u00a9 ucles 2019 4\t\tthis\tquestion\tis\tabout\tiodine\tand\tcompounds\tof\t iodine.  (a)\t\tuse\tthe\tkinetic\tparticle\tmodel\tto\tdescribe\tthe\tseparation\t between\tthe\tmolecules\t and\tthe\ttype\t of\tmotion\tof\tthe\tmolecules\tin:  \u25cfsolid\tiodine\t  ..     \u25cfiodine\tgas.\t  ..     [4]  (b)\t\tthe\tgraph\tshows\thow\tthe\tvolume\tof\tiodine\tgas\tchanges\twith\tpressure.\t the\ttemperature\t is\t kept\tconstant. volume of iodine gas pressure00 \t\tdescribe\thow\tthe\tvolume\tof\tiodine\tgas\tchanges\twith\tpressure.      ..   [1]  (c) (i)\t\tcomplete\t the\tword\tequation\tto\tshow\tthe\thalogen\tand\thalide\tcompound\t which\treact\tto\t form\tthe\tproducts\tiodine\tand\tpotassium\tbromide. + iodine +potassium bromide  [2] (ii)\t\texplain,\tin\tterms\tof\tthe\treactivity\tof\tthe\thalogens,\t why\taqueous\tiodine\tdoes\t not react with  aqueous\tpotassium\tchloride.   .   ...   [1]",
            "9": "9 0620/31/m/j/19 \u00a9 ucles 2019 [turn over  (d)\t\tiodine\treacts\twith\taqueous\tsodium\tthiosulfate,\tna2s2o3.  (i)\t\tbalance\tthe \tchemical\tequation\tfor\tthis\treaction. .na2s2o3  +  i2    na2s4o6  +  .na i  [2]  (ii)\t\tthe\tenergy \tlevel\tdiagram\tfor\tthis\treaction\tis\tshown. energyreactants products progress of reaction \t \texplain\thow\tthis\tdiagram\tshows\tthat\tthe \treaction\tis\texothermic.   .   ...   [1]  (e)\t\tdescribe\ta\ttest\tfor\tiodide\tions.  test  . \t observations\t  ..  [2]  (f)\t\tmolten\tsodium\tiodide\tis\telectrolysed. \t\tpredict\tthe\tproduct\tat\tthe\tpositive\telectrode.   ..   [1] \t [total:\t14]",
            "10": "10 0620/31/m/j/19 \u00a9 ucles 2019 5\t\tcoal\tgas\tis\tmade\tby\theating\tcoal\tin\tthe\tabsence \tof\tair. \t\tthe\tlist\tshows\tthe\tmain\tgases\tpresent\tin\tcoal\tgas. carbon dioxide carbon monoxide ethene hydrogen methane nitrogen  (a) (i)  which one\tof\tthese\tgases\tis\tan\talkane?   ...   [1]  (ii)\t\tdraw\tthe\tstructure\tof\ta\tmolecule\tof\tethene.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [1]  (iii)\t\tdescribe\thow\taqueous\tbromine\tcan\tbe\tused\tto\ttell\tthe\tdifference\t between\tmethane\tand\t ethene.   .   .   ...   [2]",
            "11": "11 0620/31/m/j/19 \u00a9 ucles 2019 [turn over  (b)\t\tethene\tmolecules\treact\twith\teach\tother\tto\tform\tpoly(ethene).  (i)\t\twhat\tis\tthe\tname\tgiven\tto\tthis\ttype\tof\tchemical\treaction?   ...   [1]  (ii)  which one\tof\tthe\tfollowing\twords\tdescribes\tthe\tethene\tmolecules\tin\tthis\treaction? \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. elements            mixtures            monomers            polymers  [1]  (iii)\t\tpoly(ethene)\tis\ta\tnon-biodegradable\tplastic. \t \twhat\tis\tmeant\tby\tthe\tterm\tnon-biodegradable ?   .   ...   [1]  (iv)\t\tdescribe\t one\tpollution\tproblem\tcaused\t by\tnon-biodegradable\tplastics.   .   ...   [1]  (c)\t\tethanol\tcan\tbe\tmade\tfrom\tethene\tand\tone\tother\treactant.  \u25cfname\tthe\tother\treactant.     \u25cfstate\tthe\tconditions\tneeded\tto\tmake\tethanol\tfrom\tethene.        [3] \t [total:\t11]",
            "12": "12 0620/31/m/j/19 \u00a9 ucles 2019 6\t\tthis\tquestion\tis\tabout\tcopper\tand\tcopper\tcompounds.  (a)\t\tdescribe\thow\tyou\tcould\tprepare\ta\tpure\tsample\tof\tcrystals\tof\thydrated\tcopper( ii)\tsulfate\tusing\t dilute\tsulfuric\tacid\tand\tan\texcess\tof\tcopper( ii)\toxide.               ..   [3]  (b)\t\tanhydrous\tcopper( ii)\tsulfate\tis\tused\tto\ttest\tfor\twater. cuso4    +    5h2o        cuso4.5h2o  anhydrous\t hydrated \t copper( ii)\tsulfate\t copper( ii)\tsulfate  (i)\t\twhat\tis\tmeant\tby\tthe\tsymbol\t \t?   ...   [1]  (ii)\t\thow\tcan\thydrated\tcopper( ii)\tsulfate\tbe\tchanged\tinto\tanhydrous\tcopper( ii)\tsulfate?   ...   [1]  (c)\t\tcomplete\t the\ttable\tto\tcalculate\tthe\trelative\tformula\tmass\tof\tanhydrous\t copper( ii)\tsulfate,\t cuso4. \t\tuse\tyour\tperiodic\t table\tto\thelp\tyou. type of atomnumber of atomsrelative atomic mass copper 1 64 1 \u00d7 64 = 64 sulfur oxygen \t relative\tformula\tmass\t=\t...  [2]",
            "13": "13 0620/31/m/j/19 \u00a9 ucles 2019 [turn over  (d)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t protons\tand\tneutrons\tin\tthe\tsulfur\tatom\t and\tcopper\tion\tshown. number\tof electronsnumber\tof neutronsnumber\tof protons 34s16 63cu2+ 29 29  [4]  (e)\t\talloys\tof\tcopper\tare\tused\tto\tmake\tcoins.  (i)\t\twhat\tis\tmeant\tby\tthe\tterm\talloy ?   .   ...   [1]  (ii)\t\tsuggest\twhy\tan\talloy\tof\tcopper\tis\tused\t to\tmake\tcoins\tinstead\tof\tusing\tpure\tcopper.   ...   [1] \t [total:\t13]",
            "14": "14 0620/31/m/j/19 \u00a9 ucles 2019 7\t\ta\tstudent\tinvestigates \tthe\trate\tof\treaction\tof\tsmall\tpieces\tof\tcalcium\tcarbonate\t with\tan\texcess\tof\t hydrochloric\tacid\tof\tconcentration\t1\t mol\t/\tdm3. caco3(s)\t\t+\t\t2hcl\t (aq)\t\t   cacl 2(aq)\t\t+\t\tco2(g)\t\t+\t\th2o(l)  (a)\t\tname\tthe\tsalt\tformed\twhen\tcalcium\tcarbonate\treacts\twith\thydrochloric\tacid.   ..   [1]  (b)\t\tthe\tgraph\tshows\thow\tthe\tmass\tof\tthe\treaction\tmixture\tchanges\twith\ttime. 200.0 199.8 199.6 199.4199.2199.0198.8 0 20 40 60 time  / s80 100 120 140mass of reaction mixture / g  (i)\t\tstate\twhy\tthe\treaction\tmixture\tdecreases\tin\tmass.   ...   [1]  (ii)\t\tcalculate\tthe\tloss\tin\tmass\tduring\tthe\tfirst\t40\tseconds\tof\tthe\texperiment.  .. g  [1]",
            "15": "15 0620/31/m/j/19 \u00a9 ucles 2019 [turn over  (iii)\t\tthe\texperiment\tis\trepeated\tusing\thydrochloric\tacid\tof\tconcentration\t2\t mol\t/\tdm3. \t \tall\tother\tconditions\tare\tkept\tthe\tsame. \t \tdraw\ta\tline\ton the grid\t for\tthe\texperiment\t using\thydrochloric\t acid\tof\tconcentration\t 2\tmol\t/\tdm3. [2]  (iv)\t\tin\tthe\texperiment,\t when\t2.00\tg\tof\tcalcium\tcarbonate\t is\tused,\tthe\tloss\tin\tmass\tof\tthe\t reaction\tmixture\tis\t0.88\t g. \t \tall\tother\tconditions\tare\tkept\tthe\tsame. \t \tcalculate\tthe\tloss\tin\tmass\twhen\t0.50\t g\tof\tcalcium\tcarbonate\tis\tused. \t loss\tin\tmass\t=\t..\tg\t\t[1]  (v)\t\tthe\texperiment\t is\trepeated\t using\tthe\tsame\tmass\tof\tdifferent\tsized\tpieces\tof\t calcium\tcarbonate. \t \tall\tother\tconditions\tare\tkept\tthe\tsame. \t \tthe\tsizes\tof\tthe\tpieces\tof\tcalcium\tcarbonate\tare: \t \u25cf\t powder \t \u25cf\t small\tpieces \t \u25cf\t large\tpieces. \t \tcomplete\t the\ttable\tby\twriting\tthe\tsizes\tof\tthe\tpieces\tof\tcalcium\tcarbonate\t in\tthe\tfirst\t column. size\tof\tpieces\tof calcium\tcarbonateinitial\trate\tof\tloss in\tmass\tin\tg\t /\ts 0.005 0.030 0.100  [1] \t [total:\t7]",
            "16": "16 0620/31/m/j/19 \u00a9 ucles 2019 8 (a)\t\tsulfur\tdioxide\tis\ta\tpollutant\tin\tthe\tair.  (i)  state one\tsource\tof\tsulfur\tdioxide\tin\tthe \tair.   ...   [1]  (ii)\t\tsulfur\tdioxide\tis\toxidised\tto\tsulfur\ttrioxide\tin\tthe\tair. \t \toxides\tof\tnitrogen\tact\tas\tcatalysts\tfor\tthis\treaction.\t \t \twhat\tis\tmeant\tby\tthe\tterm\tcatalyst\t?   .   ...   [1]  (iii)\t\tsulfur\ttrioxide\tdissolves\tin\trainwater\tto\tform\tacid\train.   which one\tof\tthe\tfollowing\tph\tvalues\tcould\tbe\tthe\tph\tof\tacid\train? \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. ph 4            ph 7            ph 9            ph 13  [1]  (iv)  state one\tadverse\teffect\tof\tacid\train\ton\tbuildings.   ...   [1]  (b)\t\tsulfur\tdioxide\tmelts\tat\t\u201373\t \u00b0c\tand\tboils\tat\t\u201310\t \u00b0c. \t\twhat\tis\tthe\tphysical\tstate\tof\tsulfur\tdioxide\tat\t\t\u201320\t \u00b0c? \t\texplain\tyour\tanswer.      ..   [2]",
            "17": "17 0620/31/m/j/19 \u00a9 ucles 2019 [turn over  (c)\t\texcess\tsulfuric\tacid\treacts\twith\tammonia\tto\tmake\ta \tsalt\twhich\tcan\tbe\tused\tas\ta\tfertiliser. \t\tstate\tthe\tname\tof\tthe\tsalt\tformed\twhen\texcess\tsulfuric\tacid\treacts\twith\tammonia.   ..   [1]  (d)\t\tthe\ttable\tshows\tsome\tobservations\t about\tthe\treactivity\tof\tfour\tmetals\twith\tdilute\tsulfuric\tacid. metal reaction\twith\tsulfuric\tacid iron a\tslow\tstream\tof\tbubbles\tis\tseen magnesium a\trapid\tstream\tof\tbubbles\tis\tseen nickel a\tfew\tbubbles\tslowly\tform tungsten no\tbubbles\tare\tseen \t\tuse\tthe\tinformation\tin\tthe\ttable\tto\tput\tthe\tfour\tmetals\tin\torder\tof\ttheir\treactivity. \t\tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2] \t [total:\t9]",
            "18": "18 0620/31/m/j/19 \u00a9 ucles 2019blank page",
            "19": "19 0620/31/m/j/19 \u00a9 ucles 2019blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/31/m/j/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s19_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 20.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32 paper 3  theory (core) may/june 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 18 printed pages and 2 blank pages. [turn overib19 06_0620_32/2rp\u00a9 ucles 2019 *9200369506* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/m/j/19 \u00a9 ucles 2019 1\t\tthe\tdiagrams\tshow\tpart\tof\tthe\tstructures\tof\tfive\tsubstances,\ta,\tb,\tc,\td\tand\te. ca2+o2\u2013 o2\u2013ca2+o2\u2013 o2\u2013ca2+ o2\u2013 ca2+fefefefe fefefefe fefefefe fefefefe ab dechch hos o o so os oo h cch hhh  (a)\t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\tstructures. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall.   state which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e:  (i)\t\tis\tan\talcohol   ...   [1]  (ii)\t\tis\tan\tionic\tcompound   ...   [1]  (iii)\t\tconducts\telectricity\twhen\tsolid   ...   [1]  (iv)\t\tcontributes \tto\tacid\train   ...   [1]  (v)\t\treacts\twith\tan\tacid\tto\tform\ta\tsalt\tand\twater.   ...   [1]  (b)\t\tsubstance\te\tis\ta\tcompound. \t\twhat\tis\tmeant\tby\tthe\tterm\tcompound  ?      ..   [1] \t [total:\t6]",
            "3": "3 0620/32/m/j/19 \u00a9 ucles 2019 [turn over 2\t\tthis\tquestion\tis\tabout\tiron\tand\tcompounds\tof\tiron.  (a)\t\tiron\tcan\tbe\tconverted\tinto\tsteel\tin\ta\tbasic\toxygen\tconverter. \t\toxygen\tis\tblown\tinto\tthe\timpure\tmolten\tiron\tto\tremove\tsome\tof\tthe\timpurities.  (i)\t\toxygen\treacts\twith\tthe\tcarbon\tin\tthe\timpure\tiron\tto\tform\tcarbon\tdioxide. \t \twrite\ta\tchemical\tequation\tfor\tthis\treaction.   ...   [2]  (ii)\t\tbasic\toxides\tin\tthe\tlining\tof\tthe\tconverter\t react\twith\timpurities\t such\tas\tsulfur\tdioxide\tto\t form\tslag. \t \twhat\ttype\tof\toxide\tis\tsulfur\tdioxide? \t \tgive\ta\treason\tfor\tyour\tanswer.   .   ...   [2]  (b)\t\tiron( iii)\tchloride,\tfe2cl 6,\tis\tproduced\twhen\tiron\tis\theated\twith\tchlorine.   the diagram shows the apparatus used.  (i)\t\tdraw\tan\tarrow\ton\tthe\tdiagram\tto\tshow\twhere\tthe\tapparatus\tis\theated. dry chlorineiron wire in a ceramic boat flask iron( iii) chloride collects here drying agent  [1]  (ii)\t\tiron( iii)\tchloride\tundergoes\tsublimation. \t \twhat\tis\tmeant\tby\tthe\tterm\tsublimation  ?   .   ...   [1]  (iii)\t\tsuggest\twhy\tthe\tiron( iii)\tchloride\tis\tcollected\tin\tthe\tflask\tand\tnot\tin\tthe\tceramic\tboat.   .   ...   [2]",
            "4": "4 0620/32/m/j/19 \u00a9 ucles 2019  (iv)\t\tat\thigher\ttemperatures,\tiron( iii)\tchloride\tdecomposes.  heatfe2cl 6  \t\t2fecl 2  +  c l 2 \t \texplain\twhy\tthis\tis\ta\tdecomposition\treaction.   .   ...   [1]  (c)\t\tiron\treacts\twith\tchlorine\tand\tother\thalogens.   name two\tother\tsubstances\twhich\treact\twith\tiron.  1  .  2  .  [2]  (d)\t\tdescribe\ta\ttest\tfor\tiron( ii)\tions.  test  . \t observations\t  ..  [2] \t [total:\t13]",
            "5": "5 0620/32/m/j/19 \u00a9 ucles 2019 [turn over 3 (a)\t\tthe\ttable\tshows\tthe\tpercentage\t by\tmass\tof\tthe\telements\tin\tthe\tearth\u2019s\tcrust\tand\tin\tthe\toceans. elementpercentage\tby\tmass in\tthe\tearth\u2019s\tcrustpercentage\tby\tmass in\tthe\toceans aluminium 8.20 0.00 calcium 3.60 0.05 chlorine 0.05 1.80 hydrogen 0.22 11.00 iron 5.00 0.00 oxygen 46.60 85.80 silicon 29.50 0.00 sodium 2.80 1.15 other\telements 4.03 total 100.00 100.00 \t\tanswer\tthese\tquestions\tusing\tonly\tthe\tinformation\tin\tthe\ttable.  (i)\t\tdeduce\tthe \tpercentage\tby\tmass\tof\tother\telements\tpresent\tin\tthe\toceans.  .. %  [1]  (ii)\t\twhich\telement\tis\tpresent\tin\tthe\tearth\u2019s\tcrust\tin\tthe\tgreatest\tpercentage\tby\tmass?   ...   [1]  (iii)\t\tgive\t two\tmajor\tdifferences\t in\tthe\tpercentage\t by\tmass\tof\tthe\telements\tin\tthe\tearth\u2019s\tcrust\t and\tin\tthe\toceans.  1  ..   .  2  ..   .  [2]",
            "6": "6 0620/32/m/j/19 \u00a9 ucles 2019  (b)\t\taluminium\toxide\tis\ta\tcompound\tpresent\tin\taluminium\tore.  (i)\t\tname\tan\tore\twhich\tcontains\taluminium\t oxide.   ...   [1]  (ii)\t\tpredict\tthe\tproducts\tof\tthe\telectrolysis\tof\tmolten\taluminium\toxide\tat: \t the\tpositive\telectrode\t  .. \t the\tnegative\telectrode.\t  ...  [2]  (iii)\t\tsuggest\twhy\taluminium\tis\textracted\tby\t electrolysis\tand\t not\tby\treduction\twith\tcarbon.   ...   [1] \t [total:\t8]",
            "7": "7 0620/32/m/j/19 \u00a9 ucles 2019 [turn over 4\t\tthis\tquestion\tis\tabout\tbromine\tand\tcompounds\tof\tbromine.  (a)\t\tuse\tthe\tkinetic\tparticle\tmodel\tto\tdescribe\tthe\tarrangement\t and\ttype\tof\tmotion\tof\tthe  molecules\tin: \t \u25cf\t liquid\tbromine\t  .   . \t \u25cf\t bromine\tgas.\t ...   .  [4]  (b)\t\tthe\tgraph\tshows\thow\tthe\tvolume\tof\tbromine\tgas\tchanges\twith\ttemperature.\t the\tpressure\tis\t kept\tconstant. volume of bromine gas temperature \t\tdescribe\thow\tthe\tvolume\tof\tthe\tbromine\tgas\tchanges\twith\ttemperature.      ..   [1]  (c) (i)\t\tcomplete\t the\tword\tequation\tto\tshow\tthe\thalogen\tand\thalide\tcompound\t which\treact\tto\t form\tthe\tproducts\tbromine\tand\tpotassium\tchloride. + bromine +potassium chloride  [2] (ii)\t\texplain,\tin\tterms\tof\tthe\treactivity\tof\tthe\thalogens,\t why\taqueous\tbromine\twill\tnot react with  aqueous\tpotassium\tchloride.   .   ...   [1]",
            "8": "8 0620/32/m/j/19 \u00a9 ucles 2019  (d)\t\tbromine\treacts\twith\thydrogen\tsulfide,\th2s.  (i)\t\tcomplete\tthe\tchemical\tequation\tfor\tthis \treaction. ...\t\t+\t\th2s  \t\t..hbr\t\t+ \t\ts  [2]  (ii)\t\tthe\tenergy \tlevel\tdiagram\tfor\tthis\treaction\tis\tshown. energy progress of reactionreactants products \t \texplain\thow\tthis\tdiagram\tshows\tthat\tthe \treaction\tis\texothermic.   .   ...   [1]  (e)\t\tdescribe\ta\ttest\tfor\tbromide\tions.  test  . \t observations\t  ..  [2] \t [total:\t13]",
            "9": "9 0620/32/m/j/19 \u00a9 ucles 2019 [turn over 5\t\tmethane,\tethane\tand\tethene\tare\thydrocarbons.  (a)  draw\tthe\tstructure\tof\ta\tmolecule\tof\tethane.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [1]  (b)  which one\tof\tthese\tcompounds\tbelongs\tto\tthe\tsame\thomologous\tseries\tas\tmethane? \t\tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. butane            methanoic acid            methanol            propene  [1]  (c)\t\tethene\tcan\tbe\tmanufactured\tby\tcracking.  (i)\t\tcomplete\tthe\tsentence\tabout\tcracking\tusing\twords\tfrom\tthe\tlist. atoms        ions        larger        molecules        reactive        smaller \t \tcracking\t is\tthe\tprocess\tof\tbreaking\t down\t\u2026\u2026\u2026\u2026\u2026.\t alkane\t\u2026\u2026\u2026\u2026\u2026\u2026..\t into    \u2026\u2026\u2026\u2026..\talkanes\tand\talkenes.  [2]  (ii)  state two\tconditions\tneeded\tfor\tcracking.  1  ..  2  ..  [2]  (d)\t\tpoly(ethene)\tis\tmade\tby\tthe\tpolymerisation\tof\tethene.   which one\tof\tthe\tstructures\trepresents\tpart\tof\ta\tpoly(ethene)\tmolecule? \t\ttick\tone\tbox.\t cch3 hch hc ch3chh hcc hcch h hc hchh hcchh hhcch3 hch oh ohcch3 ch h  [1]",
            "10": "10 0620/32/m/j/19 \u00a9 ucles 2019  (e)\t\tnylon\tis\talso\ta\tpolymer.  (i)\t\tgive\tone\tcommon\tuse\tof\tnylon.   ...   [1]  (ii)\t\tpart\tof\tthe\tstructure\tof\tnylon\tis\tshown. c( ch2)4 (ch2)6 oc onh nh nh \t \thow\tmany\tdifferent\ttypes\tof\tatom\tare\tshown\tin\tthis\tstructure?   ...   [1]  (f)\t\tthe\tstructure\tof\ta\tmonomer\tused\tto\tmake\ta\tpolymer\tis\tshown. ccoo c ch3 h hh  (i)\t\twhat\tstructural\tfeature\tof\tthis\tmolecule\t shows\tthat\tit\tis\tunsaturated?   ...   [1]  (ii)\t\tdescribe\ta\t test\tto\tshow\tthat\tthis\tcompound\tis\tunsaturated.  test  .. \t observations\t  ...  [2] \t [total:\t12]",
            "11": "11 0620/32/m/j/19 \u00a9 ucles 2019 [turn over 6\t\tthis\tquestion\tis\tabout\tcobalt\tand\tcompounds\tof\t cobalt.  (a)\t\tdescribe\thow\tyou\tcould\tprepare\ta\tpure\tsample\tof\tcrystals\tof\thydrated\tcobalt( ii)\tsulfate\tusing\t dilute\tsulfuric\tacid\tand\tan\texcess\tof\tcobalt( ii)\tcarbonate.               .. \t\t[3]  (b)\t\tcomplete\t the\ttable\tto\tcalculate\t the\trelative\tformula\tmass\tof\tanhydrous\t cobalt( ii)\tsulfate,\t coso4. \t\tuse\tyour\tperiodic\t table\tto\thelp\tyou. type of atom number\tof\tatoms relative\tatomic\tmass cobalt sulfur 1 32 1 \u00d7\t32\t=\t32 oxygen \t relative\tformula\tmass\t=\t..  [2]  (c)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t protons\tand\tneutrons\tin\tthe\toxygen\tatom\t and\tcobalt\tion\tshown.\t number\tof electronsnumber\tof neutronsnumber\tof protons 17o8 59co2+ 27 27  [4]  (d)\t\tanhydrous\tcobalt( ii)\tchloride\tis\tused\tto\ttest\tfor\twater. \t\tstate\tthe\tcolour\tchange\twhen\twater\tis\tadded\tto\tanhydrous\tcobalt( ii)\tchloride.  from ..  to  ...  [2]",
            "12": "12 0620/32/m/j/19 \u00a9 ucles 2019  (e)\t\tan\talloy\tof\tcobalt,\tchromium\tand\tmolybdenum\tis\tused\tto\tmake\tcutlery.  (i)  which one\tof\tthe\tfollowing\tdiagrams\tbest\trepresents\tthe\tstructure\tof\tthe\talloy? \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. a b c d  [1]  (ii)  which one\tof\tthese\tsubstances\tis\talso\tused\tto\tmake\tcutlery? \t \ttick\tone\tbox.  mercury  sodium \t stainless\tsteel  graphite  [1] \t [total:\t13]",
            "13": "13 0620/32/m/j/19 \u00a9 ucles 2019 [turn over question 7 starts on the next page.",
            "14": "14 0620/32/m/j/19 \u00a9 ucles 2019 7\t\ta\tstudent\tinvestigates\t the\trate\tof\treaction\tof\tmagnesium\t ribbon\twith\tan\texcess\tof\tdilute\t hydrochloric\tacid. mg\t\t+\t\t2hcl    mgcl 2\t\t+\t\th2  (a)\t\tname\tthe\tsalt\tformed\twhen\tmagnesium\treacts\twith \tdilute\thydrochloric\tacid.   ..   [1]  (b)\t\tthe\tgraph\tshows\thow\tthe\tvolume\tof\thydrogen\tproduced\tchanges\twith\ttime. 0 20 40 60 80 time  / svolum e of hydrogen / cm3 100 120 14060 50 40 30 2010 0  (i)\t\tdescribe\thow\tthe\trate\tof\treaction\tchanges\twith\ttime. \t \tuse\tthe\tgraph\tto\texplain\tyour\tanswer.   .   .   ...   [2]  (ii)\t\thow\tmany\tseconds\tdid\tit\ttake\tto\tcollect \tthe\tfirst\t25\t cm3\tof\thydrogen?  .. s  [1]",
            "15": "15 0620/32/m/j/19 \u00a9 ucles 2019 [turn over  (iii)\t\tthe\texperiment\tis\trepeated\tat\ta\thigher\ttemperature. \t \tall\tother\tconditions\tare\tkept\tthe\tsame. \t \tdraw\ta\tline\t on the grid \tfor\tthe\texperiment\tusing\ta\thigher\ttemperature.\t [2]  (iv)\t\tif\t2.4\tg\tof\tmagnesium\tis\tused,\t0.2\t g\tof\thydrogen\tis\tproduced. \t \tcalculate\t the\tmass\tof\tmagnesium\t needed\tto\tproduce\t0.8\tg\tof\thydrogen\t using\tan\texcess\t of\tdilute\thydrochloric\tacid. \t mass\tof\tmagnesium\t=\t..\tg\t\t[1] \t [total:\t7]",
            "16": "16 0620/32/m/j/19 \u00a9 ucles 2019 8 (a)\t\toxides\tof\tnitrogen\tare\tpollutants\tin\tthe\tair.  (i)\t\tone\tsource\tof\toxides\tof\tnitrogen\tin\tthe\tair\tis\tfrom\tthe\tmanufacture\tof\tnitric\tacid.   state one\tother\tsource\tof\toxides\tof\tnitrogen\tin\tthe\tair.   ...   [1]  (ii)  state one\tadverse\teffect\tof\toxides\tof\tnitrogen\ton\thealth.   ...   [1]  (iii)\t\toxides\tof\tnitrogen\tact\tas\tcatalysts. \t \twhat\tis\tmeant\tby\tthe\tterm\tcatalyst ?   .   ...   [1]  (iv)\t\toxides\tof\tnitrogen\tare\tformed\tduring\tthe \tmanufacture\tof\tnitric\tacid.   which one\tof\tthe\tph\tvalues\tcould\tbe\tthe\tph\tof\tnitric\tacid? \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. ph\t1\t\t\t\t\t\t\t\t\t\t\t\tph\t7\t\t\t\t\t\t\t\t\t\t\t\tph\t10\t\t\t\t\t\t\t\t\t\t\t\tph\t14  [1]  (b)\t\tnitrogen\tis\tpresent\tin\tfertilisers. \t\twhy\tare\tfertilisers\tadded\tto\tthe\tsoil\twhere\tcrops\tare\tgrown?      ..   [1]",
            "17": "17 0620/32/m/j/19 \u00a9 ucles 2019 [turn over  (c)\t\tthe\ttable\tshows\tsome\tobservations\t about\tthe\treactivity\t of\tfour\tmetals\twith\tdilute\t hydrochloric\tacid. metal reaction\twith\thydrochloric\tacid calcium a\trapid\tstream\tof\tbubbles\tis\tseen lead no\tbubbles\tare\tseen manganese a\tslow\tstream\tof\tbubbles\tis\tseen tin a\tfew\tbubbles\tslowly\tform \t\tuse\tthe\tinformation\tin\tthe\ttable\tto\tput\tthe\t four\tmetals\tin\torder\tof\ttheir\treactivity. \t put\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]  (d)\t\tcalcium\tmelts\tat\t839\t \u00b0c\tand\tboils\tat\t1484\t \u00b0c. \t\twhat\tis\tthe\tphysical\tstate\tof\tcalcium\tat\t1600\t \u00b0c?   ..   [1] \t [total:\t8]",
            "18": "18 0620/32/m/j/19 \u00a9 ucles 2019blank page",
            "19": "19 0620/32/m/j/19 \u00a9 ucles 2019blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/32/m/j/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s19_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33 paper 3  theory (core) may/june 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib19 06_0620_33/2rp\u00a9 ucles 2019 *2741549944* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/33/m/j/19 \u00a9 ucles 2019 1\t\tthe\tdiagram\tshows\tpart\tof\tthe\tstructures\tof\tfive\tsubstances,\ta,\tb,\tc,\td\tand\te. na+cl \u2013na+cl \u2013 na+cl \u2013na+cl \u2013 na+cl \u2013na+cl \u2013 na+cl \u2013na+cl \u2013 ar arznznznzn znznznznzn znznznznznarar ar arab decbr br br brbr br brbrbrbr chc hhhh ch hhh ch hhhh h h  (a)\t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\tstructures. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall.  (i)  which two\tof\tthese\tstructures,\t a,\tb,\tc,\td or e,\tare\tcompounds? \t ..\t\tand\t\t  .  [2]  (ii)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tis\tmonatomic?   ...   [1]  (iii)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tconducts\telectricity\twhen\tsolid?   ...   [1]  (iv)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tis\tthe\tmain\tconstituent\tof\tnatural\tgas?   ...   [1]  (v)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tis\ta\tsolid\twhich\tis\tsoluble\tin\twater?   ...   [1]  (vi)  which one\tof\tthese\tstructures,\ta,\tb,\tc,\td or e,\tis\ta\thydrocarbon?   ...   [1]",
            "3": "3 0620/33/m/j/19 \u00a9 ucles 2019 [turn over  (b)\t\tsubstance\te\tis\tpresent\tin\tair. \t\tair\tis\ta\tmixture\tof\tdifferent\tgases. \t\tdescribe\t two characteristics of a mixture.  1  .     2  .     [2] \t [total:\t9]",
            "4": "4 0620/33/m/j/19 \u00a9 ucles 2019 2\t\tthis\tquestion\tis\tabout\tiron\tand\tiron\tcompounds.  (a)\t\tiron\tcan\tbe\textracted\tfrom\tiron\tore\tby\treduction\twith\tcarbon\tin\ta\tblast\tfurnace.  (i)  which one\tof\tthese\tsubstances\tis\tan\tore\tof\tiron? \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. bauxite          graphite          hematite          limestone  [1]  (ii)\t\tthe\tequation\tshows\tone\tof\tthe\treactions\toccurring\tin\tthe\tblast\tfurnace. 2fe2o3  +  3c    4fe  +  3co2 \t \thow\tdoes\tthis\tequation\tshow\tthat\tfe2o3\tis\treduced?   .   ...   [1]  (iii)\t\tthe\tcarbon \tdioxide\tformed\tcan\tbe\treduced\tby\tcarbon. co2  +  c    2co \t \tthe\tenergy\tlevel\tdiagram\tfor\tthis\treaction\tis\tshown. energy progress of reactionco2 + c2co \t \texplain\thow\tthis\tdiagram\tshows\tthat\tthe \treaction\tis\tendothermic.   .   ...   [1]  (iv)\t\texplain\twhy\tiron\tis\textracted\tby\treduction\twith\tcarbon\tand\t not\tby\telectrolysis. \t \trefer\tto\tthe\tposition\tof\tiron\tin\tthe\treactivity\tseries\tin\tyour\tanswer.   .   ...   [1]",
            "5": "5 0620/33/m/j/19 \u00a9 ucles 2019 [turn over  (b)\t\tdescribe\t three\tproperties\t of\tiron\tthat\tshow\tthat\tit\tis\ta\ttransition\t element\tand\tnot a group i  element.   1  .   2  .   3  .  [3]  (c)\t\tiron\treacts\twith\tchlorine\tto\tform\tiron( iii)\tchloride,\tfe2cl 6.  (i)\t\tbalance\tthe \tchemical\tequation\tfor\tthis\treaction. .fe  +  .c l 2    fe2cl 6  [2]  (ii)  at 400 \u00b0c fe2cl 6\tmolecules\tdecompose. fe2cl 6    2fecl 3 \t \twhat\tis\tmeant\tby\tthe\tsymbol\t \t?   ...   [1]  (d)\t\tthe\tstructure\tof\tan\tion\tis\tshown. fecn cncn cnncnc4\u2013 \t\tdeduce\tthe\tmolecular\t formula\tof\tthis\tion\tto\tshow\tthe\tnumber\tof\tiron,\tcarbon\tand\tnitrogen\t atoms.   ..   [1] \t [total:\t11]",
            "6": "6 0620/33/m/j/19 \u00a9 ucles 2019 3  the\ttable\tshows\tthe\t percentage\tby\t mass\tof\tthe\telements\tin\tthe\toceans\tand\tin\t the\tbiosphere.\t the\t biosphere\tis\tall\tliving\torganisms. elementpercentage\tby\tmass in\tthe\toceanspercentage\tby\tmass in\tthe\tbiosphere calcium 0.05 0.40 carbon 0.01 39.00 chlorine 1.80 0.05 hydrogen 11.00 6.60 magnesium 0.12 0.10 oxygen 85.80 53.00 silicon 0.00 0.10 sodium 1.15 0.05 other\telements 0.07 total 100.00 100.00  (a)\t\tanswer\tthese\tquestions\tusing\tonly\tthe\tinformation\t in\tthe\ttable.  (i)\t\tdeduce\tthe \tpercentage\tby\tmass\tof\tother\telements\tpresent\tin\tthe\tbiosphere.  .. %  [1]  (ii)\t\twhich\tmetallic\telement\tis\tpresent\tin\tthe \toceans\tin\tthe\tgreatest\tpercentage\tby\tmass?   ...   [1]  (iii)\t\tgive\t two\tmajor\tdifferences\t in\tthe\tpercentage\t by\tmass\tof\tthe\telements\tin\tthe\toceans\tand\t in\tthe\tbiosphere.  1  ..   .  2  ..   .  [2]  (b)\t\tliving\torganisms\trespire.\twater\tis\tproduced\tduring\t respiration.  (i)\t\tname\tthe\tother\tproduct\tof\trespiration.   ...   [1]  (ii)\t\tdescribe\ta\t chemical\ttest\tfor\twater.  test  .. \t observations\t  ...  [2]  [total:\t7]",
            "7": "7 0620/33/m/j/19 \u00a9 ucles 2019 [turn over 4\t\tthis\tquestion\tis\tabout\tchlorine\tand\tcompounds\tof\tchlorine.  (a)  use\tthe\tkinetic\tparticle\tmodel\tto\tdescribe\tthe\tarrangement\t and\ttype\tof\tmotion\tof\tthe\tmolecules\t in: \t \u25cf\t solid\tchlorine\t  ...    \t \u25cf\t chlorine\tgas.\t  ...     [4]  (b)\t\tthe\tgraph\tshows\thow\tthe\tpressure\tof\tchlorine\tgas\tchanges\twhen\ttemperature\t increases.\t the\t volume\tis\tkept\tconstant. pressure of chlorine gas temperature \t\tdescribe\thow\tthe\tpressure\tof\tthe\tchlorine\tgas\tchanges\twith\ttemperature.      ..   [1]  (c) (i)\t\tcomplete\t the\tword\tequation\tto\tshow\tthe\thalogen\tand\thalide\tcompound\t which\treact\tto\t form\tthe\tproducts\tiodine\tand\tsodium\tchloride. + iodine +sodium chloride  [2]  (ii)\t\texplain,\tin\tterms\tof\tthe\treactivity\tof\tthe\thalogens,\t why\taqueous\tbromine\twill\tnot react with  aqueous\tsodium\tchloride.   .   ...   [1]  (d)\t\tchlorine\treacts\twith\twarm\tturpentine,\tc10h16. \t\tbalance\tthe\tchemical\tequation\tfor\tthis\treaction. c10h16  +  8cl 2    .c  +  .hc l  [2] \t [total:\t10]",
            "8": "8 0620/33/m/j/19 \u00a9 ucles 2019 5\t\tthe\tstructure\tof\tcompound\ts\tis\tshown. c ccch oo h hh hh occ c  (a) (i)\t\tdraw\ta\tcircle\taround\tthe\tcarboxylic\tacid \tfunctional\tgroup\tin\tthis\tstructure.\t [1]  (ii)\t\thow\tmany\tdifferent\ttypes\tof\tatom\tare\tshown\tin\tthis\tstructure?   ...   [1]  (b)\t\tthe\tmelting\tpoint\tof\tpure\t s\tis\t159\t\u00b0c. \t\tthe\tboiling\tpoint\tof\tpure\t s is 200 \u00b0c.  (i)\t\twhat\tis\tthe\tphysical\tstate\tof\tpure\ts at 100 \u00b0c? \t \texplain\tyour\tanswer.   .   ...   [2]  (ii)  which one\tof\tthese\tstatements\tabout\tan\timpure\tsample\tof\tcompound\t s\tis\tcorrect?   tick one\tbox. \t the\tmelting\tpoint\tof\timpure\t s\tis\t159\t\u00b0c\tand \t the\tboiling\tpoint\tis\tabove\t200\t \u00b0c. \t the\tmelting\tpoint\tof\timpure\t s\tis\tbelow\t159\t \u00b0c \t and\tthe\tboiling\tpoint\tis\t200\t \u00b0c. \t the\tmelting\tpoint\tof\timpure\t s\tis\t159\t\u00b0c\tand \t the\tboiling\tpoint\tis\t200\t \u00b0c. \t the\tmelting\tpoint\tof\timpure\t s\tis\tbelow\t159\t \u00b0c \t and\tthe\tboiling\tpoint\tis\tabove\t200\t \u00b0c.  [1]",
            "9": "9 0620/33/m/j/19 \u00a9 ucles 2019 [turn over  (c)\t\taqueous\tethanoic\tacid\thas\tchemical\tproperties\twhich\tare\ttypical\tof\tacids. \t\tdescribe\t two\tchemical\tproperties\tof\taqueous\tethanoic\tacid.  1  .     2  .     [2]  (d)\t\tethanol\tcan\tbe\tconverted\t into\tethene\tby\tpassing\tethanol\tvapour\tover\ta\tcatalyst\tof\t aluminium\toxide. c2h5oh    c2h4  +  x  (i)\t\tidentify\tcompound\t x.   ...   [1]  (ii)\t\texplain\twhy\ta\tcatalyst\tis\tused.   ...   [1]  (iii)\t\tdraw\tthe\tstructure\tof\ta\tmolecule\tof\tethanol.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [1]  (e)\t\tethene\tcan\tbe\tpolymerised.  (i)\t\tstate\tthe\tname\tof\tthe\tpolymer\tformed\tfrom\tethene.   ...   [1]  (ii)  terylene\tis\talso\ta\tpolymer.   state one use of terylene .   ...   [1] \t [total:\t12]",
            "10": "10 0620/33/m/j/19 \u00a9 ucles 2019 6\t\tthis\tquestion\tis\tabout\tzinc\tand\tcompounds\tof\tzinc.  (a)\t\tdescribe\thow\tyou\tcould\tprepare\ta\tpure\tsample\tof\tcrystals\tof\thydrated\tzinc\tsulfate\tusing\tdilute\t sulfuric\tacid\tand\tan\texcess\tof\tzinc.               ..   [3]  (b)\t\tthe\tequation\tshows\tthe\teffect\tof\theat\ton\tanhydrous \tzinc\tsulfate.  heat znso4  \t\tzno\t\t+\t\tso3  (i)\t\twhat\ttype\tof\tchemical\treaction\tis\tthis?   tick one\tbox. \t addition \t decomposition \t displacement \t oxidation  [1]  (ii)\t\twhen\t12.60\tg\tof\tanhydrous\t zinc\tsulfate\tis\theated,\tthe\tmass\tof\tzinc\toxide\tformed\tis\t6.34\tg. \t \tcalculate\tthe\tmass\tof\tzinc\toxide\tformed \twhen\t63.0\t g\tof\tanhydrous\tzinc\tsulfate\tis\theated. \t mass\tof\tzinc\toxide\t=\t...\tg\t\t[1]",
            "11": "11 0620/33/m/j/19 \u00a9 ucles 2019 [turn over  (c)\t\tcomplete\tthe\ttable\tto\tcalculate\tthe\trelative\tformula\t mass\tof\tanhydrous\tzinc\tsulfate,\tznso4. \t\tuse\tyour\tperiodic\t table\tto\thelp\tyou. type of atom number\tof\tatoms relative\tatomic\tmass zinc 1 65 1 \u00d7\t65\t=\t65 sulfur oxygen \t relative\tformula\tmass\t=\t..  [2]  (d)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t protons\tand\tneutrons\tin\tthe\tsulfur\tatom\t and\tzinc\tion\tshown. number\tof electronsnumber\tof neutronsnumber\tof protons 36s16 67zn2+ 30 30  [4]  (e)\t\tan\talloy\tcontains\tzinc,\tcopper\tand\taluminium. \t\twhat\tis\tmeant\tby\tthe\tterm\talloy ?      ..   [1] \t [total:\t12]",
            "12": "12 0620/33/m/j/19 \u00a9 ucles 2019 7\t\ta\tstudent\tinvestigates\t the\trate\tof\treaction\tof\tlarge\tpieces\tof\tmagnesium\t carbonate\t with\tan\texcess\t of\tdilute\tnitric\tacid. mgco3  +  2hno3  \t\tmg(no3)2  +  co2  +  h2o  (a)\t\tname\tthe\tsalt\tformed\twhen\tmagnesium\tcarbonate\t reacts\twith\tdilute\tnitric\tacid.   ..   [1]  (b)\t\tthe\tgraph\tshows\thow\tthe\tvolume\tof\tcarbon\tdioxide \tchanges\twith\ttime. 0 20 40 60 80 time  / svolume of carbon dioxide / cm3 100 120 14060 50 40 30 2010 0  (i)\t\tafter\thow\tmany\tseconds\tdid\tthe\treaction\tfinish?\t  .. s  [1]  (ii)\t\tfrom\tthe\tgraph,\tdeduce\tthe\tvolume\tof\tcarbon\tdioxide\tproduced\t during\tthe\tfirst\t50\tseconds\t of\tthe\texperiment.  ..cm3  [1]",
            "13": "13 0620/33/m/j/19 \u00a9 ucles 2019 [turn over  (iii)\t\tthe\texperiment\t is\trepeated\t using\tsmaller\tpieces\tof\tthe\tsame\tmass\tof\t  magnesium\tcarbonate. \t \tall\tother\tconditions\tare\tkept\tthe\tsame. \t \tdraw\ta\tline\ton the grid\t for\tthe\texperiment\t using\tsmaller\tpieces\tof\tmagnesium\t carbonate.  [2]  (iv)\t\thow\tdoes\tincreasing\tthe\ttemperature\taffect\tthe\trate\tof\tthis\treaction? \t \tall\tother\tconditions\tare\tkept\tthe\tsame.   ...   [1]  (v)\t\thow\tdoes\tdecreasing\tthe\tconcentration \tof\tnitric\tacid\taffect\tthe\trate\tof\tthis\treaction? \t \tall\tother\tconditions\tare\tkept\tthe\tsame.   ...   [1]  (c)\t\tnitric\tacid\tcontains\tnitrate\tions. \t\tcomplete\tthese\tsentences\tabout\tthe\ttest\tfor\tnitrate\tions\tusing\twords\tfrom\tthe\t\tlist.  aluminium ammonia blue chloride copper  green iron nitrate oxygen red \t\taqueous\tsodium\thydroxide\tand\t..\tfoil\tare\tadded\tto\tthe\tsolution \t\tbeing\ttested.\t the\tmixture\tis\twarmed\tgently.\t the\t..\tproduced\tturns \t\tdamp\t..\tlitmus\tpaper\t..\t.  [3] \t [total:\t10]",
            "14": "14 0620/33/m/j/19 \u00a9 ucles 2019 8\t\tthis\tquestion\tis\tabout\tgroup\tiv\telements\tand\ttheir\tcompounds.  (a)\t\tlead\tcompounds\tare\tpollutants\tin\tthe\tair.  (i)  state one\tsource\tof\tlead\tcompounds\tin\t the\tair.   ...   [1]  (ii)  state one\tadverse\teffect\tof\tlead\tcompounds\ton\thealth.   ...   [1]  (b)\t\tthe\ttable\tshows\thow\teasy\tit\tis\tto\treduce\tfour\tmetal \toxides\twith\tcarbon. metal\toxide ease\tof\treduction\twith\tcarbon bismuth( iii) oxide reduced\tby\tcarbon\tonly\tabove\t250\t \u00b0c chromium( iii) oxide reduced\tby\tcarbon\tonly\tabove\t1200\t \u00b0c lead( ii) oxide reduced\tby\tcarbon\tonly\tabove\t440\t \u00b0c zinc\toxide reduced\tby\tcarbon\tonly\tabove\t990\t \u00b0c \t \tuse\tthe\tinformation\tin\tthe\ttable\tto\tput\tthe\tfour\tmetals\tin\torder\tof\ttheir\treactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]  (c)\t\tpart\tof\tthe\tstructure\tof\tgraphite\tis\tshown. \t\tuse\tthe\tinformation\tfrom\tthe\tdiagram\tto\texplain\twhy\tgraphite\tis\tused\tas\ta\tlubricant.      ..   [1]",
            "15": "15 0620/33/m/j/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (d)\t\twhen\tcarbon\tburns\tin\ta\tlimited\tsupply\tof\tair,\ta\tpoisonous\tgas\tis\tformed.   name this gas.   ..   [1]  (e)\t\twhen\tcarbon\tis\tcompletely\tburned\tin\tair,\tcarbon\tdioxide\tis\tformed. \t\tcarbon\tdioxide\tforms\ta\tslightly\tacidic\tsolution\tin\twater.   which one\tof\tthese\tph\tvalues\tis\tthe\tph\tof\ta\tslightly\tacidic\tsolution? \t\tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer. ph 6               ph 7               ph 8               ph 10  [1]  (f)\t\tcarbon\tdioxide\tis\ta\tgreenhouse\tgas.  (i)  name one\tother\tmajor\tgreenhouse\tgas.   ...   [1]  (ii)  state one\teffect\tthat\tgreenhouse\tgases \thave\ton\tthe\tenvironment.   ...   [1] \t [total:\t9]",
            "16": "16 0620/33/m/j/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s19_qp_41.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/41 paper 4  theory (extended) may/june 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib19 06_0620_41/3rp\u00a9 ucles 2019 *1251990751* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/41/m/j/19 \u00a9 ucles 2019blank page",
            "3": "3 0620/41/m/j/19 \u00a9 ucles 2019 [turn over 1 this question is about the structures of atoms and ions.  (a)\t\tdefine\tthe\tterm\tproton number .      ..   [2]  (b) (i)  complete the table to show the number of protons, neutrons and electrons present in  atoms of 24mg12  and 26mg12 . number of protonsnumber of neutronsnumber of electrons 24mg12 26mg12  [2]  (ii)  what term is used to describe atoms of the same element, such as 24mg12  and 26mg12 ?   ...   [1]  (iii)  explain why the chemical properties of 24mg12  and 26mg12  are the same.   .   ...   [2]  (c)  complete the table to identify the atoms and ions which have the following numbers of protons,  neutrons and electrons. number of protonsnumber of neutronsnumber of electrons 23na+ 11 11 12 10 4 5 4 17 20 18  [4]  (d)  state the electronic structure of the following atom and ion.  al  ...  s2\u2013  ..  [2]  [total: 13]",
            "4": "4 0620/41/m/j/19 \u00a9 ucles 2019 2  z is a covalent substance. in an experiment, a sample of pure solid z was continually heated for  11 minutes.   the graph shows how the temperature of the sample of pure z\t changed\t during\tthe\tfirst\t9\tminutes. 240 220 200 180 160 140 120 100 80 60 40 20 0 0 123456 time  / minutestemperature / \u00b0c 7891 01 11 2  (a)  what is the melting point of pure z?  .. \u00b0c  [1]  (b)  the sample of pure z\tbegan\tto\tboil\tat\t9\tminutes.\tit\twas\tboiled\tfor\t2\tminutes.   use this information to sketch on the grid how the temperature of the sample of pure z changed  between\t9\tminutes\tand\t11\tminutes.\t [1]  (c)  the sample of pure z was continually heated between 2 minutes and 5 minutes.   explain, in terms of attractive forces, why there was no increase in the temperature of the  sample of pure z between 2 minutes and 5 minutes.         ..   [2]",
            "5": "5 0620/41/m/j/19 \u00a9 ucles 2019 [turn over  (d)  describe how the motion of particles of pure z changed from 0 minutes to 2 minutes.      ..   [2]  (e)  the experiment was repeated using a solid sample of impure z.   suggest the differences, if any, in the melting point and boiling point of the sample of impure z  compared to the sample of pure z.  melting point  ..  boiling point  ...  [2]  (f)  a sample of pure z was allowed to cool from 120 \u00b0c to 20 \u00b0c. the total time taken was 8 minutes.     starting from point \u00d7, sketch on the grid how the temperature of the sample of pure z changed  between 0 minutes and 8 minutes. 200 180 160 140 120 100 806040 20 0 0 123456 time  / minutestemperature / \u00b0c 7891 01 11 2  [2]  [total: 10]",
            "6": "6 0620/41/m/j/19 \u00a9 ucles 2019 3  zinc and copper are elements next to each other in the periodic table.  (a)  zinc is obtained from zinc blende in a two-step process.  \u25cf in step 1, zinc blende is converted into zinc oxide.  \u25cf in step 2, zinc oxide is converted into zinc in a blast furnace.   outline how each of these steps are done.   in your answer:  \u25cf give one chemical equation for each step  \u25cf describe how zinc is removed from the blast furnace in step 2.  step 1       chemical equation  ..  step 2       chemical equation  ..  removal of zinc in step 2  ...     [5]  (b)  name the alloy formed when zinc is mixed with copper.   ..   [1]  (c)  copper is a transition element. it can have variable oxidation states.   state two other chemical properties of transition elements which make them different from  group i elements.  1  .  2  .  [2]",
            "7": "7 0620/41/m/j/19 \u00a9 ucles 2019 [turn over  (d)  a compound of copper can be used to test for water.  (i)  state the full name of this compound of copper.   ...   [1]  (ii)  state the colour change that occurs when water is added to this compound of copper.  from ..  to    [2]  (e)  aqueous potassium iodide reacts with aqueous copper( ii) sulfate to produce iodine.  (i)  balance the chemical equation for this reaction. ki      +      cuso4            cui      +      i2      +      k2so4  [2]  (ii)  deduce the charge on the copper ion in cui.   ...   [1]  (iii)  in terms of electron transfer, explain why copper is reduced in this reaction.   ...   [1]  (iv)  identify the reducing agent.   ...   [1]  [total: 16]",
            "8": "8 0620/41/m/j/19 \u00a9 ucles 2019 4  ethanoic acid is a weak acid and hydrochloric acid is a strong acid.   both ethanoic acid and hydrochloric acid dissociate in aqueous solution.  (a) (i)\t \tdefine\tthe\tterm\tacid.   ...   [1]  (ii)  the chemical equation shows the changes which occur when the strong acid,  hydrochloric acid, is added to water. hcl (aq)    h+(aq)  +  cl \u2013(aq)   complete the chemical equation to show the changes which occur when the weak acid,  ethanoic acid, is added to water.  ch3cooh(aq)  ..   [2]  (b)  a student does experiments to show that hydrochloric acid is a strong acid and ethanoic acid is  a weak acid. the student adds an excess of hydrochloric acid and an excess of ethanoic acid  to separate samples of lumps of calcium carbonate.   only the identity of the acid is changed between the experiments. all other conditions are kept  the same.  (i)  state two observations which would show that hydrochloric acid is a stronger acid than  ethanoic acid.  1  ..  2  ..  [2]  (ii)  the student uses the same size container and checks that the pressure is the same for  each experiment.   state three other conditions which must be kept the same to ensure fair testing.  1  ..  2  ..  3  ..  [3]",
            "9": "9 0620/41/m/j/19 \u00a9 ucles 2019 [turn over  (c)  hydrochloric acid produces salts called chlorides.   magnesium carbonate reacts with hydrochloric acid to produce magnesium chloride. mgco3  +  2hcl    mgcl 2  +  h2o  +  co2   a student used 50.00 cm3 of 2.00 mol / dm3 hydrochloric acid in an experiment to produce  magnesium chloride.   calculate the mass, in g, of magnesium carbonate needed to react exactly with 50.00 cm3 of  2.00 mol / dm3 hydrochloric acid using the following steps.  \u25cf calculate the number of moles of hc l present in 50.00 cm3 of 2.00 mol / dm3 hcl.  ..  mol  \u25cf determine the number of moles of mgco3 which would react with 50.00 cm3 of  2.00 mol / dm3 hcl.  ..  mol  \u25cf calculate the relative formula mass, mr, of mgco3.  mr of mgco3 = ..  \u25cf calculate the mass of mgco3 needed to react exactly with 50.00 cm3 of 2.00 mol / dm3 hcl.  mass = ..  g  [4]",
            "10": "10 0620/41/m/j/19 \u00a9 ucles 2019  (d)  a student prepares crystals of magnesium chloride by adding an excess of   magnesium carbonate to 50.00 cm3 of 2.00 mol / dm3 hydrochloric acid. \t \tthe\tstudent\tfilters\tthe\tmixture\tand\trinses\tthe\tresidue.  (i)  why does the student add an excess  of magnesium carbonate?   ...   [1]  (ii)  why does the student rinse the residue?   ...   [1]  (iii)  describe how the student would obtain pure crystals of magnesium chloride from the  filtrate.   .   .   ...   [3]  (e)  silver chloride, agcl, is insoluble. it can be made by a precipitation reaction between aqueous  barium chloride and a suitable aqueous silver salt.  (i)  what is meant by the term precipitate ?   .   ...   [2]  (ii)  name a suitable silver salt to use to prepare silver chloride.   complete the chemical equation to show the formation of insoluble silver chloride from  aqueous barium chloride and the silver salt you have named.  name of a suitable silver salt  .. bacl 2  +  .    .  +  .  [3]  [total: 22]",
            "11": "11 0620/41/m/j/19 \u00a9 ucles 2019 [turn over 5 \tthe\tstructures\tof\tfive\talkenes,\ta, b, c, d and e, are shown. cca h hhh ccb ch3 hhh ccc ch2ch3 hhh ccd ch2ch2ch3 hh hcce ch2ch2ch2ch3 hh h  (a)  what is the general formula of alkenes?   ..   [1]  (b)  what is the molecular formula of alkene d?   ..   [1]  (c)  predict which alkene, a, b, c, d or e, has the highest boiling point.   explain your answer.  alkene .  explanation       [2]  (d)  which alkene, a, b, c, d or e, diffuses most quickly?   explain your answer.  alkene .  explanation       [2]",
            "12": "12 0620/41/m/j/19 \u00a9 ucles 2019  (e)  a student added aqueous bromine to alkene c. ccc ch2ch3 hh h   describe the colour change seen and draw the structure of the product. show all of the atoms  and all of the bonds.  colour change from    to  .  structure  [2]  (f)  two different alcohols can be produced from alkene  b by an addition reaction. ccb ch3 hh h  (i)  draw the structures of the two alcohols. show all of the atoms and all of the bonds.  [2]  (ii)  state the reagent and conditions needed to produce an alcohol from alkene b.  reagent  ...  conditions  ...   .  [3]",
            "13": "13 0620/41/m/j/19 \u00a9 ucles 2019 [turn over  (g)  alkene c can be converted into a polymer. ccc ch2ch3 hh h  (i)  what type of polymerisation occurs?   ...   [1]  (ii)  suggest the name of the polymer formed.   ...   [1]  (iii)  complete the chemical equation to show this polymerisation. ccch2ch3 hh hn  [3]  (iv)  state the empirical formula of the polymer formed.   ...   [1] \t [total:\t19]",
            "14": "14 0620/41/m/j/19 \u00a9 ucles 2019blank page",
            "15": "15 0620/41/m/j/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group.  cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/41/m/j/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s19_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/42 paper 4  theory (extended) may/june 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 13 printed pages and 3 blank pages. [turn overib19 06_0620_42/3rp\u00a9 ucles 2019 *8057635515* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/m/j/19 \u00a9 ucles 2019 1  the names of eight substances are given.  aluminium oxide calcium oxide ethanol nitrogen  iron( iii) oxide methane oxygen silicon( iv) oxide   answer the following questions about these substances.   each substance may be used once, more than once or not at all.   state which substance is:  (a)  the main constituent of natural gas   ..   [1]  (b)  a reactant in respiration   ..   [1]  (c)  the main constituent of bauxite   ..   [1]  (d)  a product of photosynthesis   ..   [1]  (e)  a greenhouse gas   ..   [1]  (f)  a macromolecular solid.   ..   [1]  [total: 6]",
            "3": "3 0620/42/m/j/19 \u00a9 ucles 2019 [turn over 2 (a)  22na11, 23na11 and 24na11 are isotopes of sodium.  (i)  describe how these sodium isotopes are the same and how they are different in terms of  the total number of protons, neutrons and electrons in each.  same  ...   .  different  ...   .  [3]  (ii)  why do all three isotopes have an overall charge of zero?   .   ...   [1]  (iii)  why do all three isotopes have the same chemical properties?   .   ...   [2]  (iv)  why do sodium ions have a charge of +1?   .   ...   [1]  (b)  carbon is an element which exists in different forms.  (i)  name two forms of the element carbon that have giant covalent structures.  ...  and   ..   [1]  (ii)  name the oxide of carbon that is a toxic gas.   ...   [1]  [total: 9]",
            "4": "4 0620/42/m/j/19 \u00a9 ucles 2019 3  this question is about phosphorus and compounds of phosphorus.  (a)  phosphorus has the formula p4. some properties of p4 are shown. melting point / \u00b0c 45 boiling point / \u00b0c 280 electrical conductivity non-conductor solubility in water insoluble  (i)  name the type of bonding that exists between the atoms in a p4 molecule.   ...   [1]  (ii)  explain, in terms of attractive forces between particles, why p4 has a low melting point.   .   ...   [1]  (iii)  explain why phosphorus is a non-conductor of electricity.   .   ...   [1]  (b)  phosphorus, p4, reacts with air to produce phosphorus( v) oxide, p4o10.  (i)  write a chemical equation for this reaction.   ...   [2]  (ii)  what type of chemical reaction is this?   ...   [1]  (c)  phosphorus( v) oxide, p4o10, is an acidic oxide.   phosphorus( v) oxide, p4o10, reacts with aqueous sodium hydroxide to form a salt containing  the phosphate ion, po43\u2013. water is the only other product.   write a chemical equation for the reaction between phosphorus( v) oxide and aqueous  sodium hydroxide.   ..   [2]",
            "5": "5 0620/42/m/j/19 \u00a9 ucles 2019 [turn over  (d)  phosphine has the formula ph3.   complete the dot-and-cross diagram to show the electron arrangement in a molecule of  phosphine. show outer shell electrons only. ph h h  [2]  (e)  phosphine, ph3, has a similar chemical structure to ammonia, nh3.   ammonia acts as a base when it reacts with sulfuric acid.  (i)  what is meant by the term base?   ...   [1]  (ii)  write a chemical equation for the reaction between ammonia and sulfuric acid.   ...   [2]  [total: 13]",
            "6": "6 0620/42/m/j/19 \u00a9 ucles 2019 4  methanol is made industrially by reacting carbon monoxide with hydrogen. the gases react at a  temperature of 250 \u00b0c and a pressure of 75 atmospheres. co(g)  +  2h2(g)    ch3oh(g)   the forward reaction is exothermic.  (a)  suggest a source of hydrogen for this industrial process.   ..   [1]  (b)  complete the table using only the words increases , decreases  or no change . effect on the rate of the reverse reactioneffect on the equilibrium yield of ch3oh(g) adding a catalyst no change increasing the temperature increases decreasing the pressure  [4]  (c)  methanol is a member of the homologous series of alcohols.  (i)  state two general characteristics of a homologous series.  1  ..  2  ..  [2]  (ii)  draw the structures of two different alcohols, each containing three carbon atoms. show  all of the atoms and all of the bonds.   name these two alcohols. name .. name ..  [4]",
            "7": "7 0620/42/m/j/19 \u00a9 ucles 2019 [turn over  (iii)  what term is used to describe compounds with the same molecular formula but different  structural formulae?   ...   [1]  (d)  alcohols react with carboxylic acids to produce esters.  (i)  the structure of ester x is shown. c oo h ch hch hh   name ester x.   ...   [1]  (ii)  give the name of the carboxylic acid and the alcohol that react together to produce ester x.  carboxylic acid    alcohol    [2]  (iii)  ester y is different from ester x but also has the formula c3h6o2.   draw the structure of ester y. show all of the atoms and all of the bonds.   .  [2]  [total: 17]",
            "8": "8 0620/42/m/j/19 \u00a9 ucles 2019 5  copper( ii) sulfate crystals, cuso4.5h2o, are hydrated.   copper( ii) sulfate crystals are made by reacting copper( ii) carbonate with dilute sulfuric acid.   the equation for the overall process is shown. cuco3  +  h2so4  +  4h2o    cuso4.5h2o  +  co2  step 1  powdered solid copper( ii) carbonate is added to 50.0 cm3 of 0.05 mol / dm3 sulfuric acid  until the copper( ii) carbonate is in excess.  step 2 the excess of copper( ii) carbonate is separated from the aqueous copper( ii) sulfate.  step 3  the aqueous copper( ii) sulfate is heated until the solution is saturated.  step 4  the solution is allowed to cool and crystallise.  step 5  the crystals are removed and dried.  (a)  calculate the maximum mass of the copper( ii) sulfate crystals, cuso4.5h2o, that can form  using the following steps.  \u25cf calculate the number of moles of h2so4 in 50.0 cm3 of 0.05 mol / dm3 h2so4.  .. mol  \u25cf determine the number of moles of cuso4.5h2o that can form.  .. mol  \u25cf the mr of cuso4.5h2o is 250.   calculate the maximum mass of cuso4.5h2o that can form.  .. g  [3]",
            "9": "9 0620/42/m/j/19 \u00a9 ucles 2019 [turn over  (b)  steps 1\u20135 were done correctly but the mass of crystals obtained was less than the maximum  mass.   explain why.   ..   [1]  (c)  state two observations that would indicate that the copper( ii) carbonate is in excess in step 1.  1  .  2  .  [2] (d)  when the reaction in step 1 is done using lumps of copper( ii) carbonate instead of powder,  the rate of reaction decreases. all other conditions are kept the same.   give a reason for this. explain your answer in terms of particles.         ..   [2]  (e)  name a different substance, other than copper( ii) carbonate, that could be added to dilute  sulfuric acid to produce copper( ii) sulfate in step 1.   ..   [1]  (f)  name the process used to separate the aqueous copper( ii) sulfate from the excess of  copper( ii) carbonate in step 2.   ..   [1]  (g)  the solution of aqueous copper( ii) sulfate was heated until it was saturated in step 3.  (i)  suggest what is meant by the term saturated solution .   .   .   ...   [2]  (ii)  what evidence would show that the solution was saturated in step 3?   ...   [1]  (iii)  why should the aqueous copper( ii) sulfate not be heated to dryness in step 3?   ...   [1]  [total: 14]",
            "10": "10 0620/42/m/j/19 \u00a9 ucles 2019 6  the halogens are the elements in group vii of the periodic table.  (a)  predict the physical state and colour of astatine at room temperature and pressure.  physical state  .  colour  .  [2]  (b)  when chlorine reacts with aqueous potassium bromide a displacement reaction occurs.  (i)  describe the colour change of the solution.  from ..  to    [2]  (ii)  write a chemical equation for this reaction.   ...   [2]  (c)  reactions occur when some aqueous solutions of halogens are added to aqueous solutions of  halides.   use the key to complete the table to show the results of adding halogens to halides.  key \t\uf033 = reaction \t\uf037 = no reaction halides kcl (aq) kbr(aq) ki(aq)halogenscl 2(aq) \uf033 br2(aq) i2(aq)  [2]  [total: 8]",
            "11": "11 0620/42/m/j/19 \u00a9 ucles 2019 [turn over 7 (a)  displacement reactions occur between metals and metal ions.   displacement reactions can be used to determine the order of reactivity of metals such as   lead (pb), nickel (ni), and silver (ag).   the ionic equation for a displacement reaction is shown. ni(s)  +  pb2+(aq)    pb(s)  +  ni2+(aq)   the ionic half-equations for this reaction are shown. ni(s)    ni2+(aq)  +  2e\u2013 pb2+(aq)  +  2e\u2013    pb(s)   the ionic half-equations show that electrons are donated by nickel atoms and accepted by  lead ions.  (i)  identify the reducing agent in the displacement reaction. give a reason for your answer.  reducing agent  .  reason  ..  [2]  (ii)  what is the general term given to the type of reaction in which electrons are transferred  from one species to another?   ...   [1]  (b)  the ionic equation for another displacement reaction is shown. pb(s)  +  2ag+(aq)    2ag(s)  +  pb2+(aq)   write the two ionic half-equations for this reaction.  1  .  2  .  [2]  (c)  use the information in (a) and (b) to put the three metals lead, nickel and silver in order of  reactivity. most reactive least reactive  [1]",
            "12": "12 0620/42/m/j/19 \u00a9 ucles 2019  (d)  nickel is a transition element. nickel is stronger than sodium.   describe two other differences in the physical properties of nickel and sodium.  1  .  2  .  [2]  (e)  predict one difference in the appearance of aqueous solutions of nickel compounds compared  to aqueous solutions of sodium compounds.      ..   [1]  (f)\t\tcopper\tis\trefined\t(purified)\tby\telectrolysis.\tnickel\tcan\tbe\trefined\tusing\ta\tsimilar\tmethod.  (i)\t\tthe\tdiagram \tshows\tthe\trefining\tof\tnickel\tby\telectrolysis.   complete the labels in the boxes. power supply +\u2013 cathode made of .. electrolyte of ..anode made of ..  [3]  (ii)  indicate, by writing n on the diagram, where nickel is produced. [1]  [total: 13]",
            "13": "13 0620/42/m/j/19 \u00a9 ucles 2019blank page",
            "14": "14 0620/42/m/j/19 \u00a9 ucles 2019blank page",
            "15": "15 0620/42/m/j/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/42/m/j/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s19_qp_43.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/43 paper 4  theory (extended) may/june 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib19 06_0620_43/4rp\u00a9 ucles 2019 *5201718844* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/43/m/j/19 \u00a9 ucles 2019 1  atoms contain particles called electrons, neutrons and protons.  (a)  complete the table. particlewhere the particle is found in an atomrelative mass relative charge orbiting the nucleus1 1840 +1 in the nucleus  [3]  (b)  how many electrons, neutrons and protons are there in the ion shown? 44ca202+  number of electrons    number of neutrons    number of protons  ..  [3]  [total: 6]",
            "3": "3 0620/43/m/j/19 \u00a9 ucles 2019 [turn over 2  magnesium exists as three isotopes, 24mg12 , 25mg12  and 26mg12 .  (a)  state, in terms of the total numbers of electrons, neutrons and protons, one difference and  two similarities between these magnesium isotopes.  difference  ...  similarity 1  ..  similarity 2  ..  [3]  (b)  all isotopes of magnesium react with dilute hydrochloric acid to make hydrogen and a salt.  (i)  why do all isotopes of magnesium react in the same way?   .   .   ...   [2]  (ii)  write a chemical equation for the reaction between magnesium and dilute hydrochloric acid.   ...   [2]  (iii)  describe a test for hydrogen.  test  ..  result  ...  [2] (c) magnesium is a metal.   describe the structure and bonding of metals. include a labelled diagram in your answer.              [3]",
            "4": "4 0620/43/m/j/19 \u00a9 ucles 2019  (d)  magnesium reacts with oxygen to form the ionic compound magnesium oxide.  (i)  complete the dot-and-cross diagrams to show the electronic structures of the ions in  magnesium oxide. show the charges on the ions. mg o   [3]  (ii)  magnesium oxide melts at 2853 \u00b0c.   why does magnesium oxide have a high melting point?   .   ...   [1]  (iii)  explain why molten magnesium oxide can conduct electricity.    .   .   ...   [1]  [total: 17]",
            "5": "5 0620/43/m/j/19 \u00a9 ucles 2019 [turn over 3 (a) (i)  sodium is in group i of the periodic table.   describe two physical properties of sodium which are different from the physical properties  of transition elements such as copper.  1  ..   .  2  ..   .  [2]  (ii) sodium reacts rapidly with water.   give one observation made when sodium is added to water.   ...   [1]  (b)  some car airbags contain sodium azide.   when a car airbag is used the sodium azide, nan3, decomposes.   the products are nitrogen and sodium.   the equation for the decomposition of sodium azide is shown. 2nan3(s)    2na(l)  +  3n2(g)   calculate the mass, in g, of sodium azide needed to produce 144 dm3 of nitrogen using the  following steps.  \u25cf calculate the number of moles in 144 dm3 of n2 measured at room temperature and  pressure.  moles of n2 = .. mol  \u25cf determine the number of moles of nan3 needed to produce this number of moles of n2.  moles of nan3 = .. mol  \u25cf calculate the relative formula mass, mr, of nan3.  mr = ..  \u25cf calculate the mass of nan3 needed to produce 144 dm3 of n2.  .. g  [4]",
            "6": "6 0620/43/m/j/19 \u00a9 ucles 2019  (c)  some airbags contain silicon( iv) oxide.   when the airbag is used sodium oxide is formed. \t \toxides\tcan\tbe\tclassified\tas\tacidic,\tamphoteric,\tbasic\tor\tneutral.   classify each of these oxides:  sodium oxide  .  silicon( iv) oxide.  ...  [2]  (d)  lead( ii) azide is insoluble in water. solid lead( ii) azide can be made in a precipitation reaction  between aqueous lead( ii) nitrate and aqueous sodium azide.   lead( ii) azide has the formula pb(n3)2.  (i)  deduce the formula of the azide ion.   ...   [1]  (ii)  complete the chemical equation for the reaction between aqueous lead( ii) nitrate and  aqueous sodium azide to form solid lead( ii) azide and aqueous sodium nitrate. include  state symbols. pb(no3)2(aq)  +  ... nan3(aq)    pb(n3)2(.)  +  ...   (.)  [2]  (iii)  describe how you could obtain a sample of lead( ii) azide that is not contaminated with  any soluble salts from the reaction mixture.   .   .   .   ...   [2]  (e)  an organic compound made from sodium azide has the composition by mass: 49.5% carbon,  7.2% hydrogen and 43.3% nitrogen.   calculate the empirical formula of the organic compound.  [3]  [total: 17]",
            "7": "7 0620/43/m/j/19 \u00a9 ucles 2019 [turn over question 4 starts on the next page.",
            "8": "8 0620/43/m/j/19 \u00a9 ucles 2019 4  solutions of ionic compounds can be broken down by electrolysis.  (a)  concentrated aqueous copper( ii) chloride was electrolysed using the apparatus shown. power supply + \u2013 anode made of platinu m concentrated aqueous copper( ii) chloridecathode madeof platinu m   the ionic half-equations for the reactions at the electrodes are shown.  negative electrode: cu2+(aq)  +  2e\u2013    cu(s)  positive electrode: 2cl \u2013(aq)    cl 2(g)  +  2e\u2013  (i)  platinum is a solid which is a good conductor of electricity.   state one other property of platinum which makes it suitable for use as electrodes.   .   ...   [1]  (ii)  state what would be seen at the positive electrode during this electrolysis.   .   ...   [1]  (iii)  state and explain what would happen to the mass of the negative electrode during this  electrolysis.   .   .   ...   [2]",
            "9": "9 0620/43/m/j/19 \u00a9 ucles 2019 [turn over  (iv)  the concentrated aqueous copper( ii) chloride electrolyte is green.   suggest what would happen to the colour of the electrolyte during this electrolysis.   explain your answer.   .   .   ...   [2]  (v)  identify the species that is oxidised during this electrolysis.   explain your answer.  species that is oxidised  ...  explanation  .   .  [2]  (b)  metal objects can be electroplated with silver.  (i)  describe how a metal spoon can be electroplated with silver.   include: \t \u25cf\t\twhat\tto\tuse\tas\tthe\tpositive\telectrode\tand\tas\tthe\tnegative\telectrode \t \u25cf\t\twhat\tto\tuse\tas\tthe\telectrolyte \t \u25cf\t\tan\tionic\thalf-equation\tto\tshow\tthe\tformation\tof\tsilver.   you may include a diagram in your answer.   .   .   .  ionic half-equation  ..  [4]  (ii)  give one reason why metal spoons are electroplated with silver.   .   ...   [1]  [total: 13]",
            "10": "10 0620/43/m/j/19 \u00a9 ucles 2019 5  carboxylic acids react with alcohols to form esters. the reaction is reversible.   the equation for the reaction between ethanoic acid and ethanol is shown. ch3cooh  +  ch3ch2oh    ch3cooch2ch3  +  h2o  (a) (i)  what is the name of the ester formed in this reaction?   ...   [1]  (ii)  draw the structure of the ester formed. show all of the atoms and all of the bonds.  [1]  (b)  the reaction between ethanoic acid and ethanol is exothermic.   draw an energy level diagram for this reaction.   on your diagram label:  \u25cf the reactants and products  \u25cf\tthe\tenergy\tchange\tof\tthe\treaction,\t\u2206 h. energy progress of reaction  [3]  (c)  concentrated sulfuric acid is a catalyst for this reaction.   what is meant by the term catalyst ?      ..   [2]",
            "11": "11 0620/43/m/j/19 \u00a9 ucles 2019 [turn over  (d)  the rate of reaction can be increased by increasing the temperature.   explain why increasing the temperature increases the rate of reaction.                  ..   [4]  (e)  the reaction between ethanoic acid and ethanol reaches equilibrium.  (i)  the reaction between ethanoic acid and ethanol is exothermic.   state and explain the effect, if any, of increasing the temperature on the amount of ester  at equilibrium.   .   .   ...   [2]  (ii)  state and explain the effect, if any, of removing water from the mixture on the amount of  ester at equilibrium.   .   .   ...   [2]  [total: 15]",
            "12": "12 0620/43/m/j/19 \u00a9 ucles 2019 6 (a)  two hydrocarbons have the structures shown. ch hhh ch hc hhydrocarbon a hydrocarbon b ch ch hchh h h h h h h h hc c cc  (i)  why are these two compounds hydrocarbons?   .   ...   [2]  (ii)  hydrocarbon b reacts in the same way as a typical alkane.   describe a chemical test to tell the difference between hydrocarbon a and hydrocarbon b.   state the name of the reagent you would use and the result you would obtain with  hydrocarbon a and hydrocarbon b.  reagent  ...  result with hydrocarbon a  ...  result with hydrocarbon b  ...  [3]  (b)  alkenes react with steam to form alcohols.   compound c is an alcohol. ch hhh ch hch hch hocompound c   draw the structure of the alkene which could be reacted with steam to make compound c.  show all of the atoms and all of the bonds.  [1]",
            "13": "13 0620/43/m/j/19 \u00a9 ucles 2019 [turn over  (c)  alkenes can form polymers.  (i)  what type of polymerisation occurs when alkenes form polymers?   ...   [1]  (ii)  part of the structure of a polymer is shown. cch3 ch3 ch3 ch3 hch cch3 ch3 hch c hch   draw the structure of the alkene from which this polymer can be made. show all of the  atoms and all of the bonds.  [1]  (iii)  polymers can undergo incomplete combustion to form carbon monoxide.   complete the chemical equation for the incomplete combustion of poly(ethene). the only  carbon-containing product is carbon monoxide. nc hh c+ ..o2   +  2n h2o hh  [2]  (d) part of the structure of a polyamide is shown.  oc och n och nh n   this polyamide is formed from identical monomers. complete the diagram to show the structure  of one monomer. show all of the atoms and all of the bonds.  [2]  [total: 12]",
            "14": "14 0620/43/m/j/19 \u00a9 ucles 2019blank page",
            "15": "15 0620/43/m/j/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/43/m/j/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_s19_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51 paper 5  practical test may/june 2019  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge assessment international education cambridge international general certificate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib19 06_0620_51/2rp\u00a9 ucles 2019 *6790855622* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/51/m/j/19 \u00a9 ucles 2019 1  you are going to investigate the reaction between aqueous sodium carbonate and aqueous  barium nitrate.   read all the instructions carefully before starting the experiment.  instructions   you are going to do one experiment.  \u25cf fill the burette up to the 0.0 cm3 mark with the aqueous sodium carbonate.  \u25cf label the test-tubes 1, 2, 3, 4, 5 and 6 and place them in order in the test-tube rack.  \u25cf use the measuring cylinder to pour 6 cm3 of the aqueous barium nitrate into each of the six  test-tubes.  \u25cf add 1.0 cm3 of aqueous sodium carbonate from the burette to test-tube 1.  \u25cf add 2.0 cm3 of aqueous sodium carbonate from the burette to test-tube 2.  \u25cf add 4.0 cm3 of aqueous sodium carbonate from the burette to test-tube 3.  \u25cf add 5.0 cm3 of aqueous sodium carbonate from the burette to test-tube 4.  \u25cf add 6.0 cm3 of aqueous sodium carbonate from the burette to test-tube 5.  \u25cf add 7.0 cm3 of aqueous sodium carbonate from the burette to test-tube 6.   using the glass rod, carefully stir the contents of each of the test-tubes. leave the contents of the  test-tubes to stand for at least 10 minutes.   you should start question 2 while you are waiting for the solid formed in the test\u2011tubes to  settle.  (a)  after 10 minutes, use a ruler to measure the height of the solid formed in each test-tube.  record your results in the table. test-tube numbervolume of aqueous sodium carbonate / cm3height of solid / mm 1 2 3456  [4]",
            "3": "3 0620/51/m/j/19 \u00a9 ucles 2019 [turn over  (b)\t\tplot\tyour\tresults\ton\tthe\tgrid.\tdraw\ta\tline\tof\tbest\tfit. 01234 volume of aqueous sodium carbonate  / cm35678height of solid  / mm  [3]",
            "4": "4 0620/51/m/j/19 \u00a9 ucles 2019  (c)  from your graph, deduce the height of the solid formed when 3.0 cm3 of aqueous  sodium carbonate is added to 6 cm3 of aqueous barium nitrate.   show clearly on the grid  how you worked out your answer.   ..   [3]  (d)  describe the trend in the heights of the solids formed in test-tubes 1\u20136.      ..   [1]  (e)  explain one improvement you could make to the experiment to obtain more accurate results  for the heights of the solid formed.  improvement  ..  explanation       [2]  (f)  suggest a different method to measure the amount of solid formed during the experiment.            ..   [3]  (g)  suggest how the reliability of the results could be checked.      ..   [1]  (h)  what type of chemical reaction occurs when aqueous sodium carbonate reacts with aqueous  barium nitrate?   ..   [1]  [total: 18]",
            "5": "5 0620/51/m/j/19 \u00a9 ucles 2019 [turn over question 2 starts on the next page.",
            "6": "6 0620/51/m/j/19 \u00a9 ucles 2019 2  you are provided with two substances, solution f and solid g.   do the following tests on the substances, recording all of your observations at each stage.   tests on solution f   divide solution f\tinto\tfive\tapproximately\tequal\tportions\tin\tfive\ttest-tubes.  (a)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tf.  ph = ..  [1]  (b)  add a strip of magnesium ribbon to the second portion of solution f. shake the mixture. test  the gas produced.   record your observations.      ..   [2]  (c)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous silver nitrate to the third portion  of solution f.   record your observations.   ..   [1]  (d)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous barium nitrate to the fourth  portion of solution f.   record your observations.   ..   [1]   keep the fifth portion of the solution f for the test in (f).",
            "7": "7 0620/51/m/j/19 \u00a9 ucles 2019 [turn over   tests on solid g  (e)  describe the appearance of solid g.   ..   [1]  (f)\t\tadd\tthe\tfifth\tportion\tof\tsolution\t f to solid g. test the gas produced.   record your observations.         ..   [3]   add about 2 cm3 of distilled water to the solution formed in the test in (f) and shake the mixture.  divide the solution formed into two approximately equal portions in two test-tubes for the tests in  (g) and (h).  (g)\t\tadd\taqueous\t sodium\thydroxide\t to\tthe\tfirst\tportion\tof\tthe\tsolution\tuntil\tno\tfurther\tchange\toccurs.   record your observations.   ..   [2]  (h)  add an excess of aqueous ammonia to the second portion of the solution.   record your observations.   ..   [1]  (i)  identify solution f.   ..   [2]  (j)  identify solid g.   ..   [2]  [total: 16]",
            "8": "8 0620/51/m/j/19 \u00a9 ucles 2019 3  steel nails rust in the presence of air and water. plan an investigation to:  \u25cf show that coating steel nails with paint helps to protect the nails from rusting  \u25cf show that coating steel nails with zinc helps to protect the nails from rusting  \u25cf determine which coating is more effective at protecting steel nails from rusting.   you are provided with:  \u25cf uncoated steel nails  \u25cf steel nails coated with paint  \u25cf steel nails coated with zinc  \u25cf common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "9": "9 0620/51/m/j/19 \u00a9 ucles 2019blank page",
            "10": "10 0620/51/m/j/19 \u00a9 ucles 2019blank page",
            "11": "11 0620/51/m/j/19 \u00a9 ucles 2019notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh 4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/51/m/j/19 \u00a9 ucles 2019tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group.  cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s19_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52 paper 5  practical test may/june 2019  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge assessment international education cambridge international general certificate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib19 06_0620_52/2rp\u00a9 ucles 2019 *9397863487* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/52/m/j/19 \u00a9 ucles 2019 1  you are going to investigate the rate of reaction between magnesium ribbon and solutions of  dilute hydrochloric acid of different concentrations, solutions h, i, j and k. the dilute hydrochloric acid  is in excess in all experiments.   read all the instructions carefully before starting the experiments.  instructions \t\tyou\tare\tgoing\tto\tdo\tfive\texperiments.  experiment 1  \u25cf use the 50 cm3 measuring cylinder to pour 30 cm3 of solution h into the beaker.  \u25cf add a 5.0 cm length of magnesium ribbon to solution h in the beaker and start the timer  immediately. stir the mixture constantly.  \u25cf measure the time taken for all of the magnesium ribbon to react and to disappear completely.  \u25cf record the time taken in the table.  \u25cf rinse out the beaker with distilled water.  experiment 2  \u25cf repeat experiment 1 but use solution i instead of solution h. record the time taken in the  table.  experiment 3  \u25cf repeat experiment 1 but use solution j instead of solution h. record the time taken in the  table.  experiment 4  \u25cf repeat experiment 1 but use solution k instead of solution h. record the time taken in the  table.  (a)  record your results from experiments 1\u20134 in the table. experiment solutionconcentration of  hydrochloric acid in mol / dm3time taken for the magnesium ribbon to disappear completely / s 1 h 2.0 2 i 1.5 3 j 1.0 4 k 0.8  [3]  (b)  experiment 5   add about 3 cm3 of solution j to a 5.0 cm length of magnesium ribbon in a test-tube.   test the gas produced with a lighted splint. record your observations.         ..   [3]",
            "3": "3 0620/52/m/j/19 \u00a9 ucles 2019 [turn over  (c)  plot your results for experiments 1\u20134 on the grid. draw a smooth line graph. 0.0 0.5 1.0 1.5 2.0 concentration of hydrochloric acid in mo l / dm32.5 3.0time taken for the magnesium ribbon to disappear completely  / s  [3]",
            "4": "4 0620/52/m/j/19 \u00a9 ucles 2019  (d)  from your graph, deduce the time taken for the magnesium ribbon to disappear completely  if a solution of hydrochloric acid of concentration 2.5 mol / dm3 were used.   show clearly on the grid  how you worked out your answer.   ..   [3]  (e) (i)  why was the same length of magnesium ribbon used in experiments 1\u20134?   ...   [1]  (ii)  suggest the effect on the results if experiments 1\u20134 were repeated using 2.5 cm lengths of  magnesium ribbon instead of 5.0 cm lengths of magnesium ribbon. explain your answer.   .   ...   [1]  (f)  suggest a different method which could be used to investigate the rate of reaction between  magnesium ribbon and dilute hydrochloric acid. state the apparatus you would use and the  measurements you would take.  apparatus  ...     measurements  ...        [3]  (g)  use your observations from experiment 5 to answer these questions.  (i)  what type of chemical reaction occurs when magnesium ribbon reacts with dilute  hydrochloric acid?   ...   [1]  (ii)  identify the gas produced.   ...   [1]  [total: 19]",
            "5": "5 0620/52/m/j/19 \u00a9 ucles 2019 [turn over question 2 starts on the next page.",
            "6": "6 0620/52/m/j/19 \u00a9 ucles 2019 2  you are provided with solid l, which contains two cations and one anion.   do the following tests on solid l, recording all of your observations at each stage.   tests on solid l  (a)  describe the appearance of solid l.   ..   [1]   use a spatula to divide solid l into two approximately equal portions.  (b)\t\theat\tthe\tfirst\tportion\tof\tsolid\t l in a hard-glass test-tube. test any gas produced with blue  cobalt( ii) chloride paper.   record your observations.      ..   [3]   add the second portion of solid l to about 10 cm3 of distilled water in a boiling tube. stopper the  boiling tube and shake the mixture to dissolve solid l and form solution l. divide solution l\tinto\tfive\t approximately\tequal\tportions\tin\tfive\ttest-tubes.  (c)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tl.  ph = ...  [1]  (d) (i)  transfer the second portion of solution l into a boiling tube. add about 3 cm3 of aqueous  sodium hydroxide.   record your observations.   ...   [1]  (ii)  gently warm the mixture from (d)(i) and test the gas produced.   record your observations.   .   ...   [2]  (e)  add an excess of aqueous ammonia to the third portion of solution l.   record your observations.   ..   [1]",
            "7": "7 0620/52/m/j/19 \u00a9 ucles 2019 [turn over  (f)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous silver nitrate to the fourth  portion of solution l.   record your observations.   ..   [1]  (g)  add a few drops of dilute nitric acid and about 1 cm3\tof\taqueous\t barium\tnitrate\tto\tthe\tfifth\t portion of solution l.   record your observations.   ..   [1]  (h)  what does the test in (b) tell you about solid l?   ..   [1]  (i)  identify the three ions in solid l.   ..   [3]  [total: 15]",
            "8": "8 0620/52/m/j/19 \u00a9 ucles 2019 3  azurite is an ore of copper which contains copper( ii) carbonate. azurite contains no other metal  ions.   plan an experiment to show how a sample of copper could be obtained from large lumps of azurite.   your answer should include:  \u25cf descriptions of the reactions involved  \u25cf the expected observations.   you are provided with a large lump of azurite and common laboratory chemicals and apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "9": "9 0620/52/m/j/19 \u00a9 ucles 2019blank page",
            "10": "10 0620/52/m/j/19 \u00a9 ucles 2019blank page",
            "11": "11 0620/52/m/j/19 \u00a9 ucles 2019notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh 4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/52/m/j/19 \u00a9 ucles 2019tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group.  cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s19_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53 paper 5  practical test may/june 2019  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge assessment international education cambridge international general certificate of secondary education this document consists of 10 printed pages and 2 blank pages. [turn overib19 06_0620_53/4rp\u00a9 ucles 2019 *4580138827* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/53/m/j/19 \u00a9 ucles 2019 1  you are going to investigate the temperature changes when two different metals, zinc and  magnesium, react with aqueous copper( ii) sulfate.   read all the instructions carefully before starting the experiments.   instructions   you are going to do three experiments.  (a) experiment 1  \u25cf put the cup provided into the 250 cm3 beaker for support.  \u25cf use the measuring cylinder to pour 25 cm3 of aqueous copper( ii) sulfate into the cup.  \u25cf measure the initial temperature of the solution and start the timer.  \u25cf measure the temperature of the solution at 30 seconds and at 60 seconds.  \u25cf record the temperatures in the table.  \u25cf at 60 seconds, add all of the zinc powder to the aqueous copper( ii) sulfate. stir the  mixture continuously with the thermometer.  \u25cf continue to stir the mixture and measure the temperature of the mixture every 30 seconds  for a total of 180 seconds.  \u25cf record your results in the table.  \u25cf empty the cup and rinse it with distilled water. time / s 0 30 60 90 120 150 180 temperature of mixture / \u00b0c  [2]  (b) experiment 2  \u25cf repeat experiment 1 but using magnesium powder instead of zinc powder.  \u25cf record your results in the table. time / s 0 30 60 90 120 150 180 temperature of mixture / \u00b0c  [2]  (c)  experiment 3  \u25cf repeat experiment 1 but using zinc granules instead of zinc powder.  \u25cf record your results in the table. time / s 0 30 60 90 120 150 180 temperature of mixture / \u00b0c  [1]",
            "3": "3 0620/53/m/j/19 \u00a9 ucles 2019 [turn over  (d)  plot your results for experiments 1\u20133 on the grid. draw three smooth line graphs.   clearly label your lines. 03 06 09 0 120 time  / s150 180temperature of mixture  / \u00b0c90 80 70 605040 30 20 10 0  [3]  (e)  from your graph , deduce the temperature of the mixture in experiment 2 after 75 seconds.   show clearly on the grid  how you worked out your answer.  .. \u00b0c  [2]",
            "4": "4 0620/53/m/j/19 \u00a9 ucles 2019  (f) (i)  from your results, which experiment was the most exothermic? explain your answer.   .   ...   [2]  (ii)  compare the rates of reaction in experiments 1 and 3. explain why the rates of reaction  are different.   .   .   ...   [2]  (g)  predict the temperature of the mixture in experiment 2 after 2 hours. explain your answer.      ..   [2]  (h)  when doing the experiments, what would be an advantage of taking the temperature readings every 15 seconds?      ..   [2]  (i)  explain why a copper can should not be used in place of the cup in these experiments.      ..   [1]  [total: 19]",
            "5": "5 0620/53/m/j/19 \u00a9 ucles 2019 [turn over question 2 starts on the next page.",
            "6": "6 0620/53/m/j/19 \u00a9 ucles 2019 2  you are provided with solid m, which is a salt.   do the following tests on solid m, recording all of your observations at each stage.  tests on solid m  (a)  describe the appearance of solid m.   ..   [1]   use a spatula to divide solid m into two approximately equal portions.  (b)\t\theat\tthe\tfirst\tportion\tof\tsolid\t m in a hard\u2011glass test\u2011tube. test any gas produced with  cobalt( ii) chloride paper.   record your observations.         ..   [4]   add the second portion of solid m to about 10 cm3 of distilled water in a boiling tube. stopper the  boiling tube and shake the mixture to dissolve solid m and form solution m. divide solution m into  three approximately equal portions in three test\u2011tubes.  (c) (i)\t \tadd\tdrops\tof\taqueous\tsodium\thydroxide \tto\tthe\tfirst\tportion\tof\tsolution\tm.   record your observations.   ...   [2]  (ii)  now add an excess of aqueous sodium hydroxide to the mixture from (c)(i).   record your observations.   ...   [1]  (d) (i)  add drops of aqueous ammonia to the second portion of solution m.   record your observations.   ...   [1]  (ii)  now add an excess of aqueous ammonia to the mixture from (d)(i).   record your observations.   ...   [1]  (e)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous barium nitrate to the third  portion of solution m.   record your observations.   ..   [2]",
            "7": "7 0620/53/m/j/19 \u00a9 ucles 2019 [turn over  (f)  what does the test in (b) tell you about solid m?   ..   [1]  (g)  identify solid m.      ..   [2]  [total: 15]",
            "8": "8 0620/53/m/j/19 \u00a9 ucles 2019 3  calcium carbonate, calcium hydroxide and calcium oxide can be used to neutralise the acid in soil. \t\tplan\tan\tinvestigation\t to\tfind\tout\twhich\tof\tthese\tcalcium\tcompounds\t neutralises\t acid\tmost\teffectively.   you are provided with the three calcium compounds, dilute hydrochloric acid and common laboratory  apparatus and chemicals.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "9": "9 0620/53/m/j/19 \u00a9 ucles 2019blank page",
            "10": "10 0620/53/m/j/19 \u00a9 ucles 2019blank page",
            "11": "11 0620/53/m/j/19 \u00a9 ucles 2019notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh 4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/53/m/j/19 \u00a9 ucles 2019tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s19_qp_61.pdf": {
            "1": "this document consists of 8 printed pages and 4 blank pages. [turn overib19 06_0620_61/3rp \u00a9 ucles 2019 *3940113605* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61 paper 6  alternative to practical may/june 2019  1 hour candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/61/m/j/19 \u00a9 ucles 2019blank page",
            "3": "3 0620/61/m/j/19 \u00a9 ucles 2019 [turn over 1  the diagram shows the apparatus a student used to prepare a dry sample of chlorine gas. chlorine  is more dense than air. concentrated hydrochloric acid manganese( iv) oxide concentrated sulfuric acidflask 1.. ..  (a)  complete the boxes to name the apparatus. [2]  (b)  use the diagram to identify two mistakes the student made.  1  .     2  .     [2]  (c)  suggest one reason why the gas produced in flask 1 is passed through concentrated  sulfuric acid.   ..   [1]  (d)  describe a test for chlorine.  test  .  observations  ..  [2] (e)  suggest why this experiment is done in a fume cupboard.   ..   [1]  [total: 8]",
            "4": "4 0620/61/m/j/19 \u00a9 ucles 2019 2  a student investigated the reaction between aqueous sodium carbonate and aqueous barium nitrate.  \u25cf a burette was filled with aqueous sodium carbonate.  \u25cf seven test-tubes were labelled 1, 2, 3, 4, 5, 6 and 7.  \u25cf a measuring cylinder was used to pour 6 cm3 of aqueous barium nitrate into each of the seven  test-tubes in a test-tube rack.  \u25cf 1.0 cm3 of aqueous sodium carbonate was added from the burette to test-tube 1.  \u25cf 2.0 cm3 of aqueous sodium carbonate was added from the burette to test-tube 2.  \u25cf 4.0 cm3 of aqueous sodium carbonate was added from the burette to test-tube 3.  \u25cf 5.0 cm3 of aqueous sodium carbonate was added from the burette to test-tube 4.  \u25cf 6.0 cm3 of aqueous sodium carbonate was added from the burette to test-tube 5.  \u25cf 7.0 cm3 of aqueous sodium carbonate was added from the burette to test-tube 6.  \u25cf 8.0 cm3 of aqueous sodium carbonate was added from the burette to test-tube 7.   a glass rod was used to stir the contents of each of the test-tubes. the contents of the test-tubes  were left to stand until the solid formed had settled. a ruler was used to measure the height of the  solid formed in each test-tube.  (a)  use a ruler to measure the heights of the solid formed in each test-tube shown in the diagram. record the heights of the solid formed in the table and complete the table. 1 test-tube number volume of aqueous sodium carbonate  / cm323456 solid7 height of solid  / mm  [3]",
            "5": "5 0620/61/m/j/19 \u00a9 ucles 2019 [turn over  (b)  plot the results on the grid. draw two intersecting lines of best fit. label the x-axis. 01234height of solid  / mm 5678100 80 60 40 20 0  [4]  (c)  from your graph, deduce the height of the solid formed when 3.0 cm3 of aqueous  sodium carbonate is added to 6 cm3 of aqueous barium nitrate.   show clearly on the grid  how you worked out your answer.  .. mm  [2]  (d)  describe the trend in the heights of the solids formed in test-tubes 1\u20137.         ..   [2]",
            "6": "6 0620/61/m/j/19 \u00a9 ucles 2019  (e)  predict what would happen if the experiment were continued using three further test-tubes  each containing 6 cm3 of aqueous barium nitrate and separately adding 9.0 cm3, 10.0 cm3 and  11.0 cm3 of aqueous sodium carbonate to each one.   explain your answer.         ..   [2]  (f)  suggest one change to the apparatus used which could be made to obtain more accurate  results.   ..   [1]  (g)  suggest a different method to measure the amount of solid formed during the experiment.            ..   [3]  (h)  suggest how the reliability of the results could be checked.      ..   [1]  [total: 18]",
            "7": "7 0620/61/m/j/19 \u00a9 ucles 2019 [turn over 3  two substances, solution f and solid g, were analysed. solution f was dilute hydrochloric acid.   tests were done on solution f and solid g.  tests on solution f   complete the expected observations.   solution f was divided into four equal portions in four test-tubes.  (a)  the ph of the first portion of solution f was tested.  ph = ..  [1]  (b)  magnesium ribbon was added to the second portion of solution f. the gas produced was  tested.  observations  ..      ..   [3]  (c)  dilute nitric acid and aqueous silver nitrate were added to the third portion of solution f.  observations     [1]  (d)  dilute nitric acid and aqueous barium nitrate were added to the fourth portion of solution f.  observations     [1]",
            "8": "8 0620/61/m/j/19 \u00a9 ucles 2019  tests on solid g   some of the tests and observations are shown. tests on solid g observations the appearance of solid g was studied. white solid test 1 dilute hydrochloric acid was added to solid g. the gas produced was tested. the solution formed was divided into two portions  for test 2.rapid effervescence limewater turned milky test 2 an excess of aqueous sodium hydroxide was  added to the first portion of the solution from test 1. an excess of aqueous ammonia was added to the  second portion of the solution from test 1.white precipitate formed which was insoluble in excess no precipitate formed  (e)  identify solid g.   ..   [2]  [total: 8]",
            "9": "9 0620/61/m/j/19 \u00a9 ucles 2019 [turn over 4  steel nails rust in the presence of air and water. plan an investigation to:  \u25cf show that coating steel nails with paint helps to protect the nails from rusting  \u25cf show that coating steel nails with zinc helps to protect the nails from rusting  \u25cf determine which coating is more effective at protecting steel nails from rusting.   you are provided with:  \u25cf uncoated steel nails  \u25cf steel nails coated with paint  \u25cf steel nails coated with zinc  \u25cf common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "10": "10 0620/61/m/j/19 \u00a9 ucles 2019blank page",
            "11": "11 0620/61/m/j/19 \u00a9 ucles 2019blank page",
            "12": "12 0620/61/m/j/19 \u00a9 ucles 2019blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s19_qp_62.pdf": {
            "1": "this document consists of 8 printed pages and 4 blank pages. [turn overib19 06_0620_62/3rp \u00a9 ucles 2019 *0271487183* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62 paper 6  alternative to practical may/june 2019  1 hour candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/m/j/19 \u00a9 ucles 2019blank page",
            "3": "3 0620/62/m/j/19 \u00a9 ucles 2019 [turn over 1  a student did the following steps to make zinc chloride crystals from solid zinc oxide.  step 1  pour 40 cm3 of dilute hydrochloric acid into a beaker. add a small amount of zinc oxide.  warm the mixture and stir it.  step 2  continue to add zinc oxide to the beaker until all of the dilute hydrochloric acid has  reacted.  step 3  remove the excess zinc oxide.  step 4  obtain crystals of zinc chloride from the solution.  (a)  name the apparatus used in step 1 to:  (i)  add the zinc oxide   ...   [1]  (ii)  warm the mixture.   ...   [1]  (b)  how did the student know that all of the dilute hydrochloric acid had reacted in step 2?      ..   [1]  (c) (i)  what is meant by the term excess in step 3?   ...   [1]  (ii)  how is the excess zinc oxide removed in step 3?   ...   [1]  (d)  describe how the crystals are obtained in step 4.         ..   [3]  (e)  suggest how the method would differ if zinc carbonate were used instead of zinc oxide.   ..   [1]  [total: 9]",
            "4": "4 0620/62/m/j/19 \u00a9 ucles 2019 2  a student investigated the rate of reaction between magnesium ribbon and solutions of dilute  hydrochloric acid of different concentrations, solutions h, i, j and k. the dilute hydrochloric acid  was in excess in all experiments.   five experiments were done.   experiment 1  \u25cf a measuring cylinder was used to pour 30 cm3 of solution h into a beaker.  \u25cf a 5.0 cm length of magnesium ribbon was then added to the beaker.  \u25cf a timer was started immediately.  \u25cf the time taken for all of the magnesium ribbon to react and to disappear completely was  measured.   experiment 2  \u25cf experiment 1 was repeated but using solution i instead of solution h.   experiment 3  \u25cf experiment 1 was repeated but using solution j instead of solution h.  experiment 4  \u25cf experiment 1 was repeated but using solution k instead of solution h.  (a)  use the stop-clock diagrams to record the time taken for each experiment in the table. experiment solutionconcentration of hydrochloric acid in mol / dm3stop-clock diagramtime taken for the magnesium ribbon to  disappear completely / s 1 h 2.00 1015 1545 5 minutes 2 i 1.50 1015 1545 5 3 j 1.00 1015 1545 5 4 k 0.80 1015 1545 5  [3]",
            "5": "5 0620/62/m/j/19 \u00a9 ucles 2019 [turn over  experiment 5   solution  j was added to some magnesium ribbon in a test-tube. the gas produced was tested. the  observations were recorded in the table. observationsrapid effervescence and the test-tube felt hot lighted splint \u2018popped\u2019  (b)  plot the results for experiments 1\u20134 on the grid. draw a smooth line graph. 0 0.5 1.0 1.5 concentration of hydrochloric acid in mo l / dm32.0 2.5 3.0time taken for the magnesium ribbon to disappear completely  / s  [3]  (c)  from your graph, deduce the time taken for the magnesium ribbon to disappear completely  if a solution of hydrochloric acid of concentration 2.5 mol / dm3 were used.   show clearly on the grid  how you worked out your answer.   ..   [3]",
            "6": "6 0620/62/m/j/19 \u00a9 ucles 2019  (d) (i)  why was the same length of magnesium used in experiments 1\u20134?   ...   [1]  (ii)  suggest the effect on the results if experiments 1\u20134 were repeated using 2.5 cm lengths of  magnesium ribbon instead of 5.0 cm lengths of magnesium ribbon. explain your answer.   .   ...   [1]  (e)  suggest a different method which a student could use to investigate the rate of reaction  between magnesium ribbon and dilute hydrochloric  acid. state the apparatus the student  would use and the measurements the student would take.  apparatus  ...     measurements  ...        [3]  (f)  use the observations from experiment 5 to answer these questions.  (i)  what type of chemical reaction occurs when magnesium ribbon reacts with dilute  hydrochloric acid?   ...   [1]  (ii)  identify the gas produced.   ...   [1]  [total: 16]",
            "7": "7 0620/62/m/j/19 \u00a9 ucles 2019 [turn over 3  two substances, solid l and solid m, were analysed. solid l was hydrated ammonium sulfate.   tests were done on solid l and solid m.  tests on solid l   complete the expected observations.  (a)  describe the appearance of solid l.   ..   [1]   solid l was divided into two portions.  (b)\t\tthe\tfirst\tportion\tof\tsolid\t l was heated in a hard-glass test-tube. any gas produced was tested  with cobalt( ii) chloride paper.  observations  ..   ..   [3]   the second portion of solid l was added to distilled water. the mixture was shaken to dissolve  solid l and form solution l. the solution of l was divided into two equal portions in two test-tubes.  (c)\t\tan\texcess\tof\taqueous\t sodium\thydroxide\t was\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t l. the  mixture was heated and the gas produced was tested.  observations  ..   ..   [2]  (d)  dilute nitric acid and aqueous barium nitrate were added to the second portion of solution l.   observation  ..   [1]",
            "8": "8 0620/62/m/j/19 \u00a9 ucles 2019   tests on solid m   some of the tests and observations are shown. tests on solid m observations solid m was dissolved in water. the solution was  divided into three portions. test 1 an excess of aqueous sodium hydroxide was  added\tto\tthe\tfirst\tportion\tof\tthe\tsolution.red-brown precipitate formed test 2 an excess of aqueous ammonia was added to the  second portion of the solution.red-brown precipitate formed test 3 dilute nitric acid and aqueous silver nitrate were  added to the third portion of the solution.white precipitate formed  (e)  identify solid m.   ..   [2]  [total: 9]",
            "9": "9 0620/62/m/j/19 \u00a9 ucles 2019 [turn over 4  azurite is an ore of copper which contains copper( ii) carbonate. azurite contains no other metal  ions.   plan an experiment to show how a sample of copper could be obtained from large lumps of azurite.   your answer should include:  \u25cf descriptions of the reactions involved  \u25cf the expected observations.   you are provided with a large lump of azurite and common laboratory chemicals and apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "10": "10 0620/62/m/j/19 \u00a9 ucles 2019blank page",
            "11": "11 0620/62/m/j/19 \u00a9 ucles 2019blank page",
            "12": "12 0620/62/m/j/19 \u00a9 ucles 2019blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s19_qp_63.pdf": {
            "1": "this document consists of 10 printed pages and 2 blank pages. [turn overib19 06_0620_63/2rp \u00a9 ucles 2019 *8930451544* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63 paper 6  alternative to practical may/june 2019  1 hour candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/63/m/j/19 \u00a9 ucles 2019blank page",
            "3": "3 0620/63/m/j/19 \u00a9 ucles 2019 [turn over 1  a student investigated the colours present in three hair dyes, p, q and r, using chromatography.   p, q and r are insoluble in water. the student suggested setting up the apparatus for the experiment  as shown. glass cover beaker solventchromatography paperrodclips  (a)  why is a lid necessary on top of the beaker?   ..   [1]  (b) (i)  identify one mistake in the student\u2019s diagram.   ...   [1]  (ii)  suggest why this mistake would stop the experiment working.   .   ...   [1]  (c)  name a suitable solvent that could be used in this experiment.   ..   [1]",
            "4": "4 0620/63/m/j/19 \u00a9 ucles 2019  (d)  a separate chromatography experiment was done using the hair dyes p, q and r. the  chromatogram obtained is shown. pq r   state three conclusions about the hair dyes p, q and r which can be deduced from the  chromatogram.  1  .  2  .  3  .  [3]  [total: 7]",
            "5": "5 0620/63/m/j/19 \u00a9 ucles 2019 [turn over 2  a student investigated the temperature changes when two different metals, zinc and magnesium,  reacted with aqueous copper( ii) sulfate.   three experiments were done.  experiment 1  \u25cf a measuring cylinder was used to pour 25 cm3 aqueous copper( ii) sulfate into a polystyrene  cup.  \u25cf the initial temperature of the solution was measured and the timer was started.  \u25cf the temperature of the solution was measured at 30 seconds and at 60 seconds.  \u25cf at 60 seconds, 5 g of zinc powder was added to the aqueous copper( ii) sulfate. the mixture  was stirred with a thermometer.  \u25cf the temperature of the mixture was measured every 30 seconds for 210 seconds. the mixture  was stirred continuously.",
            "6": "6 0620/63/m/j/19 \u00a9 ucles 2019  (a)  use the thermometer diagrams to record the temperatures in the table. 30 25 2030 25 2030 25 2050 45 4050 45 40thermometer diagramtime  / s0 30 60 90 120 150 180 210 temperature of mixture  / \u00b0c50 45 4050 45 4050 45 40  [2]  experiment 2  \u25cf experiment 1 was repeated using 5 g of magnesium powder instead of zinc powder.  (b)  use the thermometer diagrams to record the temperatures in the table. 30 25 2030 25 2030 25 2060 55 5080 75 70thermometer diagramtime  / s0 30 60 90 120 150 180 210 temperature of mixture  / \u00b0c80 75 7080 75 7080 75 70  [1]  experiment 3  \u25cf experiment 1 was repeated using 5 g of zinc granules instead of zinc powder.  (c)  use the thermometer diagrams to record the temperatures in the table. 30 25 2030 25 2030 25 2030 25 2030 25 20thermometer diagramtime  / s0 30 60 90 120 150 180 210 temperature of mixture  / \u00b0c30 25 2030 25 2030 25 20  [1]",
            "7": "7 0620/63/m/j/19 \u00a9 ucles 2019 [turn over  (d)  plot the results for experiments 1\u20133 on the grid and draw three smooth line graphs.   clearly label your lines. 03 06 09 0 120 time  / s150 180 210temperature of mixture  / \u00b0c80 70 60 50 40302010 0  [3]  (e)  from your graph , deduce the temperature of the mixture in experiment 2 after 75 seconds.   show clearly on the grid  how you worked out your answer.  .. \u00b0c  [2]",
            "8": "8 0620/63/m/j/19 \u00a9 ucles 2019  (f) (i)  from the results, which experiment was the most exothermic? explain your answer.   .   ...   [2]  (ii)  compare the rates of reaction in experiments 1 and 3. explain why the rates of reaction  are different.   .   .   ...   [2]  (g)  predict the temperature of the mixture in experiment 2 after 2 hours. explain your answer.      ..   [2]  (h)  when doing the experiments, what would be the advantage of taking the temperature readings every 15 seconds?      ..   [2]  (i)  explain why a copper can should not be used in place of the polystyrene cup in these  experiments.         ..   [2]  [total: 19]",
            "9": "9 0620/63/m/j/19 \u00a9 ucles 2019 [turn over 3  two substances, solid n and solid o were analysed. solid n was hydrated aluminium sulfate.   tests were done on solid n and solid o.   tests on solid n   complete the expected observations.  (a)  describe the appearance of solid n.  observation  ..   [1]   solid n was divided into two portions.  (b)\t\tthe\tfirst\tportion\tof\tsolid\t n was heated in a hard-glass test-tube. any gas produced was tested  with cobalt( ii) chloride paper.  observations  ..   ..   [2]   the second portion of solid n was added to distilled water. the mixture was shaken to dissolve  solid n and form solution n. solution n was divided into two equal portions in two test-tubes.  (c) (i)\t \tdrops\tof\taqueous\t sodium\thydroxide\t were\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t n until a  change was seen.  observations  .   [1]  (ii)  an excess of aqueous sodium hydroxide was then added to the mixture from (c)(i).  observations  .   [1]  (d)  dilute nitric acid and aqueous barium nitrate were added to the second portion of solution n.  observations     [1]",
            "10": "10 0620/63/m/j/19 \u00a9 ucles 2019  tests on solid o   some of the tests and observations are shown. tests on solid o observations test 1 a\tflame\ttest\twas\tdone\ton\tsolid\t o. lilac\tflame solid o was dissolved in water. the solution was  divided into two portions.test 2an excess of aqueous sodium hydroxide was  added\tto\tthe\tfirst\tportion\tof\tthe\tsolution.no change test 3 dilute nitric acid and aqueous silver nitrate were  added to the second portion of the solution.white precipitate formed  (e)  identify solid o.   ..   [2]  [total: 8]",
            "11": "11 0620/63/m/j/19 \u00a9 ucles 2019 [turn over 4  calcium carbonate, calcium hydroxide and calcium oxide can be used to neutralise the acid in soil. \t\tplan\tan\tinvestigation\t to\tfind\tout\twhich\tof\tthese\tcalcium\tcompounds\t neutralises\t acid\tmost\teffectively.   you are provided with the three calcium compounds, dilute hydrochloric acid and common laboratory  apparatus and chemicals.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "12": "12 0620/63/m/j/19 \u00a9 ucles 2019blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group.  cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w19_qp_11.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level1/level 2 certifica te.  this document consists of 14 printed pages and 2 blank pages.  ib19 11_0620_11/3rp  \u00a9 ucles 2019 [turn over     *5634656915 * cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/11     paper 1  multiple choice (core)  october/november 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/11/o/n/19  1 the diagram shows a cup of hot tea.        which row describes the water particles in the air above the cup compared with the water particles in the cup?     moving faster closer together  a \u0016 \u001a  b \u0016 \u0016  c \u001a \u001a  d \u001a \u0016      2 a student is asked to measure the time taken for 0.4  g of magnesium carbonate to react  completely with 25.0  cm3 of dilute hydrochloric acid.    which pieces of apparatus does the student need?  a balance, stop-clock, pipette  b balance, stop-clock, thermometer  c balance, pipette, thermometer  d stop-clock, pipette, thermometer    3 a fractionating column is used to separate the hydrocarbon fractions in petroleum by fractional  distillation.    which row describes the properties of the fractions that condense at the top of the fractionating column?     size of molecule boiling point  a large high  b large low  c small high  d small low     ",
            "3": "3  \u00a9 ucles 2019 0620/11/o/n/19 [turn over  4 some information about solid silver chloride and solid sodium chloride is shown.    \u25cf silver chloride and sodium chlo ride do not dissolve in kerosene.  \u25cf silver chloride is insoluble in water but sodium chloride is soluble in water.  \u25cf the boiling point of silver chloride is 1547  \u00b0c and the boiling point of sodium chloride  is 1413  \u00b0c.    which processes are used to separate a mixture of solid silver chloride and solid sodium  chloride?  a add kerosene, stir and then filter.  b add water, stir and then filter.  c add water, stir and then leave to crystallise.  d add water, stir and then perform fractional distillation.      5 a covalent molecule m contains four shared pairs of electrons.    what is m?  a ammonia, nh 3  b hydrogen chloride, hc l  c methane, ch 4  d water, h 2o     6 an isotope of chromium is represented by  cr52 24 .    which statement about an atom of this isotope of chromium is correct?  a it contains 24 electrons.  b it contains 24 neutrons.  c it contains 28 protons.  d it contains 52 neutrons.     ",
            "4": "4  \u00a9 ucles 2019 0620/11/o/n/19  7 substances p and q both conduct electricity.    p is a mixture of two different types of atom.    q is made of only one type of atom.    which row describes p and q?     p q  a alloy element  b alloy compound  c compound alloy  d compound element      8 graphite is a form of carbon.    why can graphite be used as a lubricant?  a graphite contains unbonded electrons which move through the structure.  b graphite contains weak covalent bonds so the atoms move easily.  c graphite has a low melting point so it easily turns into a liquid.  d graphite has weak attractive forces between layers so they can move.    9 the structure of a molecule is shown.    ch hh ch ho ch hch hh     what is the formula of the molecule?  a cho b c 2h5o c c 4h8o d c 4h10o    10 during the electrolysis of concentrated hydrochloric acid, gases are produced at both electrodes.    which statement describes the test result for the gas collected at the negative electrode?  a it bleaches damp litmus paper.  b it burns with a \u2018pop\u2019.  c it relights a glowing splint.  d it turns limewater milky.     ",
            "5": "5  \u00a9 ucles 2019 0620/11/o/n/19 [turn over  11 which statements about endothermic reactions are correct?    1 the energy of the products is greater than the energy of the reactants.  2 the energy of the reactants is greater than the energy of the products.  3 the temperature of the surroundings increases during the reaction.  4 the temperature of the surroundings decreases during the reaction.    a 1 and 3 only b 1 and 4 only c 2 and 3 only d 2 and 4 only     12 equations for the formation of anhydrous cobalt( ii) chloride and anhydrous copper( ii) sulfate are  shown.    coc l 2\u20226h 2o  \u2192  coc l 2  +  6h 2o    cuso 4\u20225h 2o  \u2192  cuso 4  +  5h 2o    which statement about the reactions is not correct?  a both reactions are exothermic.  b both reactions are reversible.  c hydrated cobalt( ii) chloride changes colour from pink to blue.  d hydrated copper( ii) sulfate changes colour from blue to white.      13 a method used to investigate the rate of reaction of calcium carbonate with dilute hydrochloric  acid under different conditions is shown.    \u25cf place 50  cm3 of dilute hydrochloric acid in a conical flask.  \u25cf add a known volume of water to the conical flask.  \u25cf heat the conical flask to the required temperature.  \u25cf add 1.0  g of calcium carbonate to the conical flask.  \u25cf measure the time taken for the reaction to finish.    which volume of water and which temperature gives the shortest time taken for the reaction to finish?     volume of water  added  / cm3 temperature  / \u00b0c  a 10 30  b 10 50  c 40 30  d 40 50     ",
            "6": "6  \u00a9 ucles 2019 0620/11/o/n/19  14 which is a chemical change?  a boiling water  b cooking an egg  c dissolving sugar  d melting ice cubes      15 mercury (ii) oxide, hgo, decomposes when heated.    the equation is shown.    2hgo  \u2192  2hg  +  o 2    why is this a reduction reaction?  a the products weigh less than the reactants.  b there are fewer reactants than products.  c there is a gain of oxygen.  d there is a loss of oxygen.     16 carbonic acid is a weak acid formed when carbon dioxide dissolves in water.    what is the ph of the solution?  a 1 b 5 c 7 d 9     17 solid x is tested as shown.    reaction with dilute  aqueous sodium  hydroxide flame test reaction with dilute  hydrochloric acid  no reaction red flame gas produced which  turned limewater milky    what is x?  a copper (ii) carbonate  b lithium carbonate  c potassium carbonate  d sodium sulfate     ",
            "7": "7  \u00a9 ucles 2019 0620/11/o/n/19 [turn over  18 which oxide is basic?  a carbon dioxide  b sodium oxide  c sulfur dioxide  d water      19 a method used to make copper( ii) sulfate crystals is shown.    1 place dilute sulfuric acid in a beaker.  2 warm the acid.  3 add copper( ii) oxide until it is in excess.  4 filter the mixture.  5 evaporate the filtrate until crystals start to form.  6 leave the filtrate to cool.    what are the purposes of step 3 and step 4?     step 3 step 4  a to ensure all of the acid has reacted to obtain solid copper( ii) sulfate  b to ensure all of the acid has reacted to remove the excess of copper( ii) oxide c to speed up the reaction to obtain solid copper( ii) sulfate  d to speed up the reaction to remove the excess of copper( ii) oxide    20 which set of elements shows the change from metallic to non-metallic character across a period  of the periodic table?  a beryllium \u2192 magnesium \u2192 calcium  b fluorine \u2192 bromine \u2192 iodine  c oxygen \u2192 boron \u2192 lithium  d sodium \u2192 silicon \u2192 chlorine      21 which pair of elements reacts together most violently?  a chlorine and lithium  b chlorine and potassium  c iodine and lithium  d iodine and potassium     ",
            "8": "8  \u00a9 ucles 2019 0620/11/o/n/19  22 what is not a typical property of a transition element?  a acts as a catalyst  b forms coloured compounds  c has a high melting point  d has a low density      23 part of the periodic table is shown.    which element is used to provide an inert atmosphere?    a b c d      24 some properties of substance x are listed.    \u25cf it conducts electricity when molten.  \u25cf it has a high melting point.  \u25cf it burns in oxygen and the oxide dissolves in water to give a solution with ph 11.    what is x?  a a covalent compound  b a macromolecule  c a metal  d an ionic compound     ",
            "9": "9  \u00a9 ucles 2019 0620/11/o/n/19 [turn over  25 four different metals are reacted with an equal volume of dilute hydrochloric acid. the results of  the reactions are shown.    metal rate of  effervescence  calcium very high  copper  none  iron low  magnesium high    what is the order of reactivity of the four metals starting with the most reactive?  a iron \u2192 magnesium \u2192 calcium \u2192 copper  b magnesium \u2192 calcium \u2192 copper \u2192 iron  c copper \u2192 iron \u2192 magnesium \u2192 calcium  d calcium \u2192 magnesium \u2192 iron \u2192 copper     26 iron is extracted from its ore in a blast furnace.    the equations for four different reactions are shown.    1 4fe  +  3co 2  \u2192  2fe 2o3  +  3c  2 co 2  \u2192  c  +  o 2  3 co 2  +  c  \u2192  2co  4 fe 2o3  +  3co  \u2192  2fe  +  3co 2    which equations represent reactions that occur in the blast furnace?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 3 and 4 only      27 which statement is correct?  a aluminium is used in the manufacture of aircraft because it has a high density.  b copper is used for cooking utensils because it is a good conductor of heat.  c mild steel is used for car bodies because it is resistant to corrosion.  d stainless steel is used for cutlery because it is a conductor of electricity.     ",
            "10": "10  \u00a9 ucles 2019 0620/11/o/n/19  28 river water contains soluble impurities, insoluble impurities and bacteria.    river water is made safe to drink by filtration and chlorination.    which statement is correct?  a filtration removes bacteria and insoluble impurities, and chlorination removes soluble  impurities.  b filtration removes insoluble impurities, and chlorination kills the bacteria.  c filtration removes soluble and insoluble impurities, and chlorination kills the bacteria.  d filtration removes soluble impurities and bacteria, and chlorination removes insoluble  impurities.     29 clean, dry air contains nitrogen, oxygen and small amounts of other gases. the noble gases  have been left out of the table.    which row shows the composition of clean, dry air?     nitrogen  / % oxygen  / % other gases  a 21 78 small amount of carbon dioxide  b 21 78 small amount of carbon monoxide  c 78 21 small amount of carbon dioxide  d 78 21 small amount of carbon monoxide     ",
            "11": "11  \u00a9 ucles 2019 0620/11/o/n/19 [turn over  30 the apparatus shown is set up and left for a week.    damp iron wool air water     which diagram shows the level of the water at the end of the week?    a b c d       31 farmers add calcium oxide (lime) and ammonium salts to their fields.    the compounds are not added at the same time because they react with each other.    which gas is produced in this reaction?  a ammonia  b carbon dioxide  c hydrogen  d nitrogen    32 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0016 \u001a key  b greenhouse gas \u0016 \u0016 \u0016= true  c present in unpolluted air \u001a \u001a \u001a= false  d produced during respiration \u001a \u0016      ",
            "12": "12  \u00a9 ucles 2019 0620/11/o/n/19  33 what is not a use of sulfur dioxide?  a as a bleach  b as a food preservative  c in the manufacture of wood pulp for paper  d treating acidic soils      34 which process is used to obtain lime from limestone?  a cracking  b fractional distillation  c neutralisation  d thermal decomposition      35 petroleum is separated by fractional distillation.    which statement about the fractions produced is correct?  a bottled gas for heating and cooking is obtained from the naphtha fraction.  b diesel oil is used as a fuel for jet aircraft.  c substances used to make polishes are obtained from the lubricating fraction.  d the kerosene fraction contains many useful waxes.     36 which compounds have similar chemical properties?  a butanol and butanoic acid  b ethane and ethene  c methane and butane  d propene and propanol      37 which statement about a molecule of ethane is correct?  a an ethane molecule has at least one double covalent bond.  b it has c\u2013h and c\u2013o bonds.  c an ethane molecule has seven covalent bonds.  d its bonds are formed by the transfer of electrons.     ",
            "13": "13  \u00a9 ucles 2019 0620/11/o/n/19  38 which products are obtained by the cracking of an alkane?     alkene hydrogen water  a \u0016 \u0016 \u0016  b \u0016 \u0016 \u001a  c \u0016 \u001a \u0016  d \u001a \u0016 \u0016      39 which statements about aqueous ethanoic acid are correct?    1 it has a ph value of 10.  2 it reacts with metal carbonates to produce carbon dioxide gas. 3 it reacts with magnesium metal to produce hydrogen gas.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    40 the diagram shows the structure of a monomer and of the polymer made from it.    nnh hch hch hch hc     what are the monomer and polymer?     monomer polymer  a ethane poly(ethane)  b ethane poly(ethene)  c ethene poly(ethane)  d ethene poly(ethene)       ",
            "14": "14  \u00a9 ucles 2019 0620/11/o/n/19  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/11/o/n/19  blank page",
            "16": "16  \u00a9 ucles 2019 0620/11/o/n/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w19_qp_12.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level1/level 2 certifica te.  this document consists of 15 printed pages and 1 blank page.  ib19 11_0620_12/4rp  \u00a9 ucles 2019 [turn over     *4346624822* cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/12     paper 1  multiple choice (core)  october/november 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number  on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/12/o/n/19  1 the diagram shows a cup of hot tea.        which row describes the water particles in the air above the cup compared with the water particles in the cup?     moving faster closer together  a \u0016 \u001a  b \u0016 \u0016  c \u001a \u001a  d \u001a \u0016      2 a student is asked to measure the time taken for 0.4  g of magnesium carbonate to react  completely with 25.0  cm3 of dilute hydrochloric acid.    which pieces of apparatus does the student need?  a balance, stop-clock, pipette  b balance, stop-clock, thermometer  c balance, pipette, thermometer  d stop-clock, pipette, thermometer    3 petroleum is a mixture.    which method is used to separate petroleum?  a chromatography  b cracking  c filtration  d fractional distillation    ",
            "3": "3  \u00a9 ucles 2019 0620/12/o/n/19 [turn over  4 magnesium hydroxide can be obtained from sea water as shown.    calcium hydroxide solutionreaction vessel separation stage solid magnesium hydroxidesea water containing magnesium ions aqueous calcium chloride     which process is used in the separation stage to separate solid magnesium hydroxide from the mixture?  a crystallisation  b filtration  c distillation  d chromatography    5 what is the total number of electrons in one molecule of ammonia, nh 3?  a 6 b 8 c 10 d 11      6 an isotope of lithium has the symbol li7 3.    what is the arrangement of electrons in one atom of this isotope of lithium?    a b c d      7 which statement about an alloy is correct?  a it is a compound made of two or more elements, one of which is a metal.  b it is a layer of a metal plated onto another metal.  c it is a mixture of a metal with other elements.  d it is a single element. ",
            "4": "4  \u00a9 ucles 2019 0620/12/o/n/19  8 graphite is a form of carbon.    why can graphite be used as a lubricant?  a graphite contains unbonded electrons which move through the structure.  b graphite contains weak covalent bonds so the atoms move easily.  c graphite has a low melting point so it easily turns into a liquid.  d graphite has weak attractive forces between layers so they can move.    9 magnesium burns in oxygen to form magnesium oxide.    the equation for the reaction is shown.    2mg  +  o 2  \u2192  2mgo    which mass of magnesium oxide is formed when 48  g of magnesium is burned?  a 20  g b 40  g c 80  g d 160  g     10 the apparatus used for electrolysis is shown.    electrodes electrolytepower supply     which statement is correct?  a copper forms at the anode in some electrolysis reactions.  b hydrogen forms at the cathode in some electrolysis reactions.  c oxygen forms at the cathode in some electrolysis reactions.  d the negative electrode is called the anode.    ",
            "5": "5  \u00a9 ucles 2019 0620/12/o/n/19 [turn over  11 the temperature of the water in two beakers, x and y, is measured as 21.5  \u00b0c.    5 g of sodium chloride is dissolved in the water in beaker x. the temperature changes to 18.0  \u00b0c.    5 g of calcium oxide is dissolved in the water in beaker y. the temperature changes to 29.4  \u00b0c.    which types of process are occurring in beakers x and y?     x y  a endothermic endothermic  b endothermic exothermic  c exothermic endothermic  d exothermic exothermic      12 which reaction produces a white-coloured substance?  a adding water to anhydrous cobalt( ii) chloride  b adding water to anhydrous copper( ii) sulfate  c heating hydrated cobalt( ii) chloride  d heating hydrated copper( ii) sulfate      13 four students collect the gas produced from the reaction of calcium carbonate with dilute  hydrochloric acid. each student records the time taken to collect a volume of gas.    which results show the highest average rate of reaction?  a 15  cm3 of gas collected in 20 seconds  b 50  cm3 of gas collected in 40 seconds  c 75  cm3 of gas collected in 80 seconds  d 90  cm3 of gas collected in 100 seconds    14 which row identifies a chemical and a physical change?      chemical change physical change  a boiling ethanol burning ethanol  b burning ethanol evaporating ethanol  c dissolving ethanol in water burning ethanol  d evaporating ethanol dissolving ethanol in water     ",
            "6": "6  \u00a9 ucles 2019 0620/12/o/n/19  15 when magnesium is heated with zinc oxide a reaction occurs.    the equation is shown.    mg  +  zno  \u2192  mgo  +  zn    which substance is oxidised?  a magnesium  b magnesium oxide  c zinc  d zinc oxide     16 which statement describes the properties of hydrochloric acid?  a carbon dioxide is produced when limestone reacts with hydrochloric acid.  b hydrogen is produced when sodium hydrox ide reacts with hydrochloric acid.  c methyl orange turns yellow in strong hydrochloric acid.  d red litmus paper turns blue when dipped into hydrochloric acid.    17 a sample of x is heated with aqueous sodium  hydroxide and small pieces of aluminium.    a gas is produced which turns red litmus paper blue.    aqueous sodium hydroxide solution is added to a second sample of x. a pale green precipitate is observed.    what is x?  a ammonium nitrate  b chromium( ii) chloride  c iron( ii) nitrate  d iron( ii) sulfate      18 which element forms an acidic oxide?  a calcium  b lithium  c magnesium  d sulfur     ",
            "7": "7  \u00a9 ucles 2019 0620/12/o/n/19 [turn over  19 a method used to make copper( ii) sulfate crystals is shown.    1 place dilute sulfuric acid in a beaker.  2 warm the acid.  3 add copper( ii) oxide until it is in excess.  4 filter the mixture.  5 evaporate the filtrate until crystals start to form.  6 leave the filtrate to cool.    what are the purposes of step 3 and step 4?     step 3 step 4  a to ensure all of the acid has reacted to obtain solid copper( ii) sulfate  b to ensure all of the acid has reacted to remove the excess of copper( ii) oxide c to speed up the reaction to obtain solid copper( ii) sulfate  d to speed up the reaction to remove the excess of copper( ii) oxide    20 which statements describe changes that occur from left to right across a period of the periodic  table?    1 the atomic number of the elements increases.  2 the metallic character of the elements decreases. 3 the physical state of the elements changes from gas to solid.    a 2 only b 1 and 2 only c 1 and 3 only d 2 and 3 only      21 which pair of elements reacts together most violently?  a chlorine and lithium  b chlorine and potassium  c iodine and lithium  d iodine and potassium      22 which is a typical property of transition elements?  a can act as catalysts  b poor electrical conductivity  c low melting point  d low density     ",
            "8": "8  \u00a9 ucles 2019 0620/12/o/n/19  23 helium is a noble gas.    which statement about helium is correct?  a it has eight electrons in its outer shell.  b it is a diatomic gas.  c it is reactive.  d it is used for filling balloons.    24 some properties of substance x are listed.    \u25cf it conducts electricity when molten.  \u25cf it has a high melting point.  \u25cf it burns in oxygen and the oxide dissolves in water to give a solution with ph 11.    what is x?  a a covalent compound  b a macromolecule  c a metal  d an ionic compound    ",
            "9": "9  \u00a9 ucles 2019 0620/12/o/n/19 [turn over  25 four unknown metals, q, r, s and t, are reacted with water, steam and dilute hydrochloric acid.    the results are shown in the table.     reaction with  water reaction with  steam reaction with dilute  hydrochloric acid  q slow reaction fast reaction fast reaction  r no reaction no reaction no reaction  s no reaction very slow reaction slow reaction  t fast reaction explodes explodes    which statements are correct?    1 r is the least reactive metal.  2 t could be potassium.  3 s is more reactive than q and r. 4 metals react faster with steam than they do with water.  a 1, 2 and 4 only  b 1 and 2 only  c 2 and 3 only  d 3 and 4 only     26 what is added to molten iron to make steel?  a small amounts of carbon  b limestone and coke  c calcium oxide and oxygen  d hematite and air    27 which row describes the uses of aluminium, copper and mild steel?     aluminium copper mild steel  a aircraft bodies electrical wiring car bodies  b car bodies cooking utensils electrical wiring  c electrical wiring aircraft bodies food containers  d food containers aircraft bodies cooking utensils     ",
            "10": "10  \u00a9 ucles 2019 0620/12/o/n/19  28 river water contains soluble impurities, insoluble impurities and bacteria.    river water is made safe to drink by filtration and chlorination.    which statement is correct?  a filtration removes bacteria and insoluble impurities, and chlorination removes soluble  impurities.  b filtration removes insoluble impurities, and chlorination kills the bacteria.  c filtration removes soluble and insoluble impurities, and chlorination kills the bacteria.  d filtration removes soluble impurities and bacteria, and chlorination removes insoluble  impurities.     29 clean, dry air contains nitrogen, oxygen and small amounts of other gases. the noble gases  have been left out of the table.    which row shows the composition of clean, dry air?     nitrogen  / % oxygen  / % other gases  a 21 78 small amount of carbon dioxide  b 21 78 small amount of carbon monoxide  c 78 21 small amount of carbon dioxide  d 78 21 small amount of carbon monoxide     ",
            "11": "11  \u00a9 ucles 2019 0620/12/o/n/19 [turn over  30 the apparatus shown is set up and left for a week.    damp iron wool air water     which diagram shows the level of the water at the end of the week?    a b c d       31 farmers add calcium oxide (lime) and ammonium salts to their fields.    the compounds are not added at the same time because they react with each other.    which gas is produced in this reaction?  a ammonia  b carbon dioxide  c hydrogen  d nitrogen    32 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0016 \u001a key  b greenhouse gas \u0016 \u0016 \u0016= true  c present in unpolluted air \u001a \u001a \u001a= false  d produced during respiration \u001a \u0016      ",
            "12": "12  \u00a9 ucles 2019 0620/12/o/n/19  33 which statement about the uses of sulfur dioxide is not correct?  a it is used as a bleach in the manufacture of paper.  b it is used as a food preservative.  c it is used in the manufacture of cement.  d it is used in the manufacture of sulfuric acid.      34 which statement about limestone and lime is correct?  a limestone combines with water to produce slaked lime.  b lime is obtained from limestone by oxidation.  c lime is used in the desulfurisation of flue gases.  d lime is used in the treatment of alkaline soil.      35 some fractions obtained from petroleum are listed.     fraction use position collected  in the  fractionating column  1 gasoline waxes and polishes below refinery gas  2 bitumen making roads above kerosene  3 kerosene jet fuel below gasoline  4 refinery gas heating and cooking above gasoline    which rows are correct?  a 1, 3 and 4  b 2, 3 and 4  c 3 and 4 only  d 4 only     ",
            "13": "13  \u00a9 ucles 2019 0620/12/o/n/19 [turn over  36 the structures of three compounds are shown.    hch hch hbr hh ch hc hch hbr b r ch hh     which statement explains why these three compounds have similar chemical properties?  a they all contain bromine, carbon and hydrogen.  b they all contain the same functional group.  c they are all carbon-based molecules.  d they are all saturated molecules.    37 which statement about ethane is correct?    a it rapidly decolourises aqueous bromine.  b it does not burn.  c it forms long-chain compounds called polymers.  d it only contains single bonds between its atoms.      38 which products are obtained by the cracking of an alkane?     alkene hydrogen water  a \u0016 \u0016 \u0016  b \u0016 \u0016 \u001a  c \u0016 \u001a \u0016  d \u001a \u0016 \u0016      39 which statement about an aqueous solution of ethanoic acid is correct?  a it reacts with magnesium to form water as one of the products.  b it reacts with sodium carbonate to form carbon dioxide.  c it reacts with sodium hydroxide to form hydrogen.  d it turns red litmus paper blue.    ",
            "14": "14  \u00a9 ucles 2019 0620/12/o/n/19  40 the diagram shows the structure of a monomer and of the polymer made from it.    nnh hch hch hch hc     what are the monomer and polymer?     monomer polymer  a ethane poly(ethane)  b ethane poly(ethene)  c ethene poly(ethane)  d ethene poly(ethene)       ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.   cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/12/o/n/19  blank page",
            "16": "16  \u00a9 ucles 2019 0620/12/o/n/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w19_qp_13.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level1/level 2 certifica te.  this document consists of 14 printed pages and 2 blank pages.  ib19 11_0620_13/3rp  \u00a9 ucles 2019 [turn over     *3282949697 * cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/13     paper 1  multiple choice (core)  october/november 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/13/o/n/19  1 the diagram shows a cup of hot tea.        which row describes the water particles in the air above the cup compared with the water particles in the cup?     moving faster closer together  a \u0016 \u001a  b \u0016 \u0016  c \u001a \u001a  d \u001a \u0016      2 a student is asked to measure the time taken for 0.4  g of magnesium carbonate to react  completely with 25.0  cm3 of dilute hydrochloric acid.    which pieces of apparatus does the student need?  a balance, stop-clock, pipette  b balance, stop-clock, thermometer  c balance, pipette, thermometer  d stop-clock, pipette, thermometer    3 which method is used to separate a mixture of the following liquids?    liquid boiling point  / \u00b0c  methanol 64.5  ethanol 78.5  propan-1-ol 97.2  butan-1-ol 117.0    a crystallisation  b evaporation  c filtration  d fractional distillation    ",
            "3": "3  \u00a9 ucles 2019 0620/13/o/n/19 [turn over  4 a sample of wax is heated. it begins to melt at 45  \u00b0c and finishes melting at 49  \u00b0c.    a sample of liquid is heated. it begins to boil at 141  \u00b0c and remains at 141  \u00b0c while it boils.    which conclusion can be made from these results?  a both substances are impure.  b both substances are pure.  c the wax is not a pure substance and the liquid is a pure substance.  d the wax is a pure substance and the liquid is not a pure substance.      5 in which molecule are all the outer shell electrons involved in covalent bonding?  a cl 2 b ch 4 c hcl d nh 3     6 the numbers of protons, neutrons and electrons present in the atoms p, q, r and s are shown.    atom number  of protons number  of neutrons number  of electrons  p 4 5 4  q 5 6 5  r 6 6 6  s 6 7 6    which atoms are isotopes of the same element?  a p and q only b q and r only c r and s only d p and s only     7 what is an alloy?  a a compound of two metallic elements  b a compound of metallic and non-metallic elements  c a mixture of a metal and at least one other element  d a pure metal element    8 graphite is a form of carbon.    why can graphite be used as a lubricant?  a graphite contains unbonded electrons which move through the structure.  b graphite contains weak covalent bonds so the atoms move easily.  c graphite has a low melting point so it easily turns into a liquid.  d graphite has weak attractive forces between layers so they can move. ",
            "4": "4  \u00a9 ucles 2019 0620/13/o/n/19  9 the thermal decomposition of 12.5  g of limestone (impure calcium carbonate) produces 5  g of  calcium oxide.    which mass of calcium oxide is produced by the thermal decomposition of 30  g of limestone?  a 6  g b 12  g c 15  g d 24  g      10 dilute sulfuric acid and lead (ii) bromide are separately electrolysed.    which statements are correct?    1 colourless gases are evolved when dilute sulfuric acid is electrolysed.  2 lead (ii) bromide can be electrolysed when molten.  3 lead is formed at the positive electrode when lead (ii) bromide is electrolysed.  4 sulfate ions are produced at the negative electrode when dilute sulfuric acid is  electrolysed.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 3 and 4 only      11 an energy level diagram for a reaction is shown.    energy progress of reaction    which statement and explanation about this reaction are correct?     statement explanation  a the reaction is endothermic the products have more energy than the reactants  b the reaction is endothermic the products have less energy than the reactants  c the reaction is exothermic the products have more energy than the reactants  d the reaction is exothermic the products  have less energy than the reactants     ",
            "5": "5  \u00a9 ucles 2019 0620/13/o/n/19 [turn over  12 hydrated cobalt( ii) chloride decomposes when heated.    cocl 2\u20226h 2o    coc l 2  +  6h 2o    which statements about this reaction are correct?    1 coc l 2 is anhydrous cobalt( ii) chloride.  2 heat is released when water is added to coc l 2.  3 coc l 2\u20226h 2o is blue.  4 the reaction is not reversible.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      13 in experiment 1, small lumps of limestone ar e added to dilute hydrochloric acid at 40  \u00b0c.    the volume of carbon dioxide released is measured at regular time intervals.    the results are shown.    volume of carbon dioxidereleased timeexperiment 1 experiment 2     which changes give the results shown in experiment 2?     limestone temperature  / \u00b0c  a large lumps 40  b powder 40  c powder 60  d small lumps 60     ",
            "6": "6  \u00a9 ucles 2019 0620/13/o/n/19  14 a sequence of changes involving sulfur is shown.    s(s)change 1s(l) so2(g)change 2     which row describes the changes?     change 1 change 2  a chemical chemical  b chemical physical  c physical chemical  d physical physical     15 in which equation is the iron oxidised?  a c  +  feo  \u2192  co  +  fe  b 3co  +  fe 2o3  \u2192  3co 2  +  2fe  c fe 2o3  +  h 2  \u2192  2feo  +  h 2o  d pbo  +  fe  \u2192  pb  +  feo    16 which statements about dilute sulfuric acid are correct?    1 it turns red litmus paper blue.  2 it reacts with magnesium( ii) oxide to form magnesium( ii) sulfate and water.  3 it reacts with magnesium to form magnesium( ii) sulfate and carbon dioxide.  4 its ph is below ph 7.    a 1 and 2 only b 1 and 3 only c 2 and 4 only d 3 and 4 only     ",
            "7": "7  \u00a9 ucles 2019 0620/13/o/n/19 [turn over  17 x is a white powder. the following tests are done on x.    \u25cf no precipitate is seen when a few drops of aqueous sodium hydroxide are added to  a solution of x.  \u25cf no gas is formed when x is heated with aqueous sodium hydroxide.  \u25cf x gives a lilac colour when put into a flame.  \u25cf when acidified aqueous silver nitrate is added to a solution of x a yellow precipitate  is seen.    what is x?  a ammonium bromide  b ammonium iodide  c potassium bromide  d potassium iodide     18 which three oxides are all acidic?  a cao, no 2, so 2  b cao, co 2, na 2o  c co 2, no 2, so 2  d co 2, na 2o, so 2     19 a method used to make copper( ii) sulfate crystals is shown.    1 place dilute sulfuric acid in a beaker.  2 warm the acid.  3 add copper( ii) oxide until it is in excess.  4 filter the mixture.  5 evaporate the filtrate until crystals start to form. 6 leave the filtrate to cool.    what are the purposes of step 3 and step 4?     step 3 step 4  a to ensure all of the acid has reacted to obtain solid copper( ii) sulfate  b to ensure all of the acid has reacted to remove the excess of copper( ii) oxide c to speed up the reaction to obtain solid copper( ii) sulfate  d to speed up the reaction to remove the excess of copper( ii) oxide    ",
            "8": "8  \u00a9 ucles 2019 0620/13/o/n/19  20 which element from period 3 of the periodic table has the most metallic character?  a aluminium  b magnesium  c silicon  d sodium      21 which pair of elements reacts together most violently?  a chlorine and lithium  b chlorine and potassium  c iodine and lithium  d iodine and potassium      22 which statement does not describe a transition element?  a it is used as a catalyst in industrial reactions.  b it has white compounds and gives a yellow flame test.  c it produces a black oxide and a blue sulfate.  d it forms green, violet and orange compounds.      23 which statement describes a gas which is in group viii of the periodic table?  a a colourless gas that helps substances burn.  b a pollutant gas present in car exhausts.  c a gas that is less dense than air and makes a \u2018pop\u2019 sound with a lighted splint.  d a gas that is used in lamps.     24 some properties of substance x are listed.    \u25cf it conducts electricity when molten.  \u25cf it has a high melting point.  \u25cf it burns in oxygen and the oxide dissolves in water to give a solution with ph 11.    what is x?  a a covalent compound  b a macromolecule  c a metal  d an ionic compound   ",
            "9": "9  \u00a9 ucles 2019 0620/13/o/n/19 [turn over  25 a metal reacts vigorously with water.    which statement about the metal is correct?  a it is above hydrogen in the reactivity series.  b it is below magnesium in the reactivity series.  c its oxide can be reduced with carbon.  d it does not react with dilute acids.    26 iron is extracted from its ore in the blast furnace.    which raw material is not used in this process?  a bauxite  b coke  c hematite  d limestone     27 which statement about metals and their uses is correct?  a aluminium is used in the manufacture of aircraft because it has a high density.  b copper is used to make cooking utensils because it is a poor conductor of heat.  c mild steel is used to make car bodies because it is brittle and breaks easily.  d stainless steel is used to make cutlery because it is resistant to corrosion.    28 river water contains soluble impurities, insoluble impurities and bacteria.    river water is made safe to drink by filtration and chlorination.    which statement is correct?  a filtration removes bacteria and insoluble impurities, and chlorination removes soluble  impurities.  b filtration removes insoluble impurities, and chlorination kills the bacteria.  c filtration removes soluble and insoluble impurities, and chlorination kills the bacteria.  d filtration removes soluble impurities and bacteria, and chlorination removes insoluble  impurities.    ",
            "10": "10  \u00a9 ucles 2019 0620/13/o/n/19  29 clean, dry air contains nitrogen, oxygen and small amounts of other gases. the noble gases  have been left out of the table.    which row shows the composition of clean, dry air?     nitrogen  / % oxygen  / % other gases  a 21 78 small amount of carbon dioxide  b 21 78 small amount of carbon monoxide  c 78 21 small amount of carbon dioxide  d 78 21 small amount of carbon monoxide     30 the apparatus shown is set up and left for a week.    damp iron wool air water     which diagram shows the level of the water at the end of the week?    a b c d      ",
            "11": "11  \u00a9 ucles 2019 0620/13/o/n/19 [turn over  31 farmers add calcium oxide (lime) and ammonium salts to their fields.    the compounds are not added at the same time because they react with each other.    which gas is produced in this reaction?  a ammonia  b carbon dioxide  c hydrogen  d nitrogen     32 which information about carbon dioxide and methane is correct?      carbon dioxide methane   a formed when vegetation decomposes \u0016 \u001a key  b greenhouse gas \u0016 \u0016 \u0016= true  c present in unpolluted air \u001a \u001a \u001a= false  d produced during respiration \u001a \u0016      33 what are uses of sulfur dioxide?    1 as a bleach in the manufacture of wood pulp  2 as a food preservative 3 in the conversion of iron to steel 4 in water treatment    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 2 and 4 only     34 which type of reaction occurs when lime is manufactured from limestone?  a combustion  b neutralisation  c redox  d thermal decomposition     35 which statement is correct?  a bitumen is used as a fuel for ships.  b coal, natural gas and oxygen are all fuels.  c hydrogen is the main constituent of natural gas.  d petroleum is separated into useful substances by fractional distillation. ",
            "12": "12  \u00a9 ucles 2019 0620/13/o/n/19  36 the structures of four organic compounds, w, x, y and z, are shown.    hch hcz h hh hch hcy h ho hx hch hcw h hchh h hch hc hch h    which compounds are members of the same homologous series?  a w and x b w and z c x and y d y and z    37 how many different types of bonds are present in ethanoic acid, ch 3cooh?     type of bond  c\u2013h c\u2013c c=o  a 3 1 1  b 3 0 2  c 4 0 2  d 4 1 2      38 which products are obtained by the cracking of an alkane?     alkene hydrogen water  a \u0016 \u0016 \u0016  b \u0016 \u0016 \u001a  c \u0016 \u001a \u0016  d \u001a \u0016 \u0016      39 which statement about aqueous ethanoic acid is correct?  a it reacts with magnesium to form oxygen gas.  b it reacts with sodium carbonate to form carbon dioxide gas.  c it turns red litmus paper blue.  d it turns methyl orange yellow.     ",
            "13": "13  \u00a9 ucles 2019 0620/13/o/n/19  40 the diagram shows the structure of a monomer and of the polymer made from it.    nnh hch hch hch hc     what are the monomer and polymer?     monomer polymer  a ethane poly(ethane)  b ethane poly(ethene)  c ethene poly(ethane)  d ethene poly(ethene)       ",
            "14": "14  \u00a9 ucles 2019 0620/13/o/n/19  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/13/o/n/19  blank page",
            "16": "16  \u00a9 ucles 2019 0620/13/o/n/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w19_qp_21.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certific ate.  this document consists of 13 printed pages and 3 blank pages.  ib19 11_0620_21/3rp  \u00a9 ucles 2019 [turn over     *8533346900 * cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/21     paper 2  multiple choice (extended)  october/november 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/21/o/n/19  1 samples of four gases are released in a room at the same time.    the gases are carbon dioxide, co 2, hydrogen chloride, hc l, hydrogen sulfide, h 2s, and nitrogen  dioxide, no 2.    which gas diffuses fastest?  a carbon dioxide  b hydrogen chloride  c hydrogen sulfide  d nitrogen dioxide     2 a student is asked to measure the time taken for 0.4  g of magnesium carbonate to react  completely with 25.0  cm3 of dilute hydrochloric acid.    which pieces of apparatus does the student need?  a balance, stop-clock, pipette  b balance, stop-clock, thermometer  c balance, pipette, thermometer  d stop-clock, pipette, thermometer      3 four different food colourings are analysed using chromatography.    the results are shown on the chromatogram. the diagram is not drawn to scale.    which food colouring contains a component with an rf value of 0.3?    10 cm 8 cm 6 cm 4 cm 2 cmsolvent front baseline abcd    ",
            "3": "3  \u00a9 ucles 2019 0620/21/o/n/19 [turn over  4 which statement about an ionic compound is not correct?  a it conducts electricity when dissolved in water.  b it has a high melting point due to strong attractive forces between ions.  c it has a regular lattice of oppositely charged ions in a \u2018sea of electrons\u2019.  d the ionic bonds are formed between metallic and non-metallic elements.      5 an isotope of chromium is represented by cr52 24 .    which statement about an atom of this isotope of chromium is correct?  a it contains 24 electrons.  b it contains 24 neutrons.  c it contains 28 protons.  d it contains 52 neutrons.      6 element x has two isotopes, x12 6 and x14 6.    which statement about these isotopes is correct?  a they have different chemical properties because they have different numbers of neutrons.  b they have the same chemical properties because they have the same number of outer shell  electrons.  c they have the same nucleon number because the sum of the number of protons and  electrons is the same.  d they have different positions in the periodic  table because they have different numbers of  neutrons.      7 how are the structures of diamond and silicon (iv) oxide similar?  a molecules of both diamond and silicon (iv) oxide are held together by weak attractive forces.  b they both contain atoms arranged in planes held together by weak bonds.  c they both contain ions that are free to move.  d the carbon in diamond and the silicon in silicon (iv) oxide each have four covalent bonds.      8 which statement describes the structure of copper?  a it has a lattice of negative ions in a \u2018sea of electrons\u2019.  b it has a lattice of negative ions in a \u2018sea of protons\u2019.  c it has a lattice of positive ions in a \u2018sea of electrons\u2019.  d it has a lattice of positive ions in a \u2018sea of protons\u2019. ",
            "4": "4  \u00a9 ucles 2019 0620/21/o/n/19  9 four fertilisers are each supplied in 100  kg bags.    which fertiliser supplies the greatest mass of nitrogen per 100  kg bag?  a ammonium nitrate, nh 4no 3  b ammonium phosphate, (nh 4)3po 4  c ammonium sulfate, (nh 4)2so 4  d urea, co(nh 2)2    10 calcium carbonate reacts with dilute hydrochloric acid.    the equation for the reaction is shown.    caco 3  +  2hc l   \u2192  cac l 2  +  h 2o  +  co 2    1.00  g of calcium carbonate is added to 50.0  cm3 of 0.0500  mol  / dm3 hydrochloric acid.    which volume of carbon dioxide is made in this reaction?  a 30  cm3 b 60  cm3 c 120  cm3 d 240  cm3     11 which rows correctly show cathode and anode products from the electrolysis of the named  electrolyte?     electrolyte cathode product anode product  1   copper (ii) sulfate solution  using copper electrodes copper   oxygen    2 molten lead (ii) bromide lead bromine  3 dilute sodium bromide solution hydrogen oxygen  4   copper (ii) sulfate solution  using carbon electrodes hydrogen   oxygen      a 1 and 2 only b 1 and 4 only c 2 and 3 only d 3 and 4 only      12 what are the ionic half-equations for the electrode reactions during the electrolysis of  concentrated aqueous sodium chloride?     anode cathode   a cl 2  +  2e\u2013  \u2192  2c l \u2013 h 2  \u2192  2h+  +  2e\u2013  b 2c l \u2013  \u2192  c l 2  +  2e\u2013 2h+  +  2e\u2013  \u2192  h2  c h2  \u2192  2h+  +  2e\u2013 c l 2  +  2e\u2013  \u2192  2c l \u2013  d 2h+  +  2e\u2013  \u2192  h2 2c l \u2013  \u2192  c l 2  +  2e\u2013   ",
            "5": "5  \u00a9 ucles 2019 0620/21/o/n/19 [turn over  13 which statements about endothermic reactions are correct?    1 the energy of the products is greater than the energy of the reactants.  2 the energy of the reactants is greater than the energy of the products.  3 the temperature of the surroundings increases during the reaction.  4 the temperature of the surroundings decreases during the reaction.    a 1 and 3 only b 1 and 4 only c 2 and 3 only d 2 and 4 only    14 which gases are used to generate electricity in a fuel cell?  a carbon dioxide and oxygen  b hydrogen and methane  c hydrogen and oxygen  d methane and carbon dioxide    15 which is a chemical change?  a boiling water  b cooking an egg  c dissolving sugar  d melting ice cubes     16 the rate of reaction between magnesium and dilute hydrochloric acid is increased by increasing  the concentration of the acid.    how does this affect the reacting particles?     collision rate of particles proportion of particles with  sufficient energy to react  a increases increases  b increases stays the same  c stays the same increases  d stays the same stays the same     ",
            "6": "6  \u00a9 ucles 2019 0620/21/o/n/19  17 dinitrogen tetroxide, n 2o4, is converted into nitrogen dioxide, no 2, in a reversible reaction.    n2o4(g)    2no 2(g)    the forward reaction is endothermic.    which conditions give the highest equilibrium yield of nitrogen dioxide?     pressure  / atmospheres temperature  a 2 high  b 2 low  c 50 high  d 50 low      18 the equation for the reaction between iron( ii) sulfate and bromine is shown.    6feso 4  +  3br 2  \u2192  2fe 2(so 4)3  +  2febr 3    which row identifies the oxidising agent and the reducing agent?     oxidising agent reducing agent  a br2 feso 4  b feso 4 br 2  c febr 3 fe 2(so 4)3  d fe2(so 4)3 febr 3      19 which statement about amphoteric oxides is correct?  a they are made by combining an ac idic oxide with a basic oxide.  b they react with water to give a solution of ph 7.  c they react with both acids and bases.  d they do not react with acids or bases.     20 carbonic acid is a weak acid formed when carbon dioxide dissolves in water.    what is the ph of the solution?  a 1 b 5 c 7 d 9    ",
            "7": "7  \u00a9 ucles 2019 0620/21/o/n/19 [turn over  21 a method used to make copper( ii) sulfate crystals is shown.    1 place dilute sulfuric acid in a beaker.  2 warm the acid.  3 add copper( ii) oxide until it is in excess.  4 filter the mixture.  5 evaporate the filtrate until crystals start to form.  6 leave the filtrate to cool.    what are the purposes of step 3 and step 4?     step 3 step 4  a to ensure all of the acid has reacted to obtain solid copper( ii) sulfate  b to ensure all of the acid has reacted to remove the excess of copper( ii) oxide c to speed up the reaction to obtain solid copper( ii) sulfate  d to speed up the reaction to remove the excess of copper( ii) oxide     22 lead (ii) sulfate is an insoluble salt.    which process is not used to prepare a pure sample of this salt?  a crystallisation  b drying  c filtration  d precipitation    23 part of the periodic table is shown.    which element is used to provide an inert atmosphere?    a b c d      ",
            "8": "8  \u00a9 ucles 2019 0620/21/o/n/19  24 which pair of elements reacts together most violently?  a chlorine and lithium  b chlorine and potassium  c iodine and lithium  d iodine and potassium      25 which pair of compounds shows that transition elements have variable oxidation states?  a cr2o3 and crbr 3  b cuso 4 and cuc l 2  c fe2o3 and fec l 2  d nio and nic l 2      26 some properties of substance x are listed.    \u25cf it conducts electricity when molten.  \u25cf it has a high melting point.  \u25cf it burns in oxygen and the oxide dissolves in water to give a solution with ph 11.    what is x?  a a covalent compound  b a macromolecule  c a metal  d an ionic compound    27 which statement is correct?  a aluminium is used in the manufacture of aircraft because it has a high density.  b copper is used for cooking utensils because it is a good conductor of heat.  c mild steel is used for car bodies because it is resistant to corrosion.  d stainless steel is used for cutlery because it is a conductor of electricity.    ",
            "9": "9  \u00a9 ucles 2019 0620/21/o/n/19 [turn over  28 iron rusts but aluminium does not easily corrode.    which statement explains why aluminium does not easily corrode?  a it is an alloy.  b it is below iron in the reactivity series.  c it is not a transition element.  d its surface is protected by an oxide layer.     29 which statement about the extraction of aluminium is correct?  a aluminium is formed at the cathode during the electrolysis of aluminium oxide.  b hematite is mainly aluminium oxide.  c molten cryolite is used to raise the melting point of the aluminium oxide.  d oxygen gains electrons at the anode duri ng the electrolysis of aluminium oxide.    30 river water contains soluble impurities, insoluble impurities and bacteria.    river water is made safe to drink by filtration and chlorination.    which statement is correct?  a filtration removes bacteria and insoluble impurities, and chlorination removes soluble  impurities.  b filtration removes insoluble impurities, and chlorination kills the bacteria.  c filtration removes soluble and insoluble impurities, and chlorination kills the bacteria.  d filtration removes soluble impurities and bacteria, and chlorination removes insoluble  impurities.    31 which physical property is used to separate the nitrogen and oxygen from air?    a boiling point  b density  c electrical conductivity  d molecular mass    ",
            "10": "10  \u00a9 ucles 2019 0620/21/o/n/19  32 the apparatus shown is set up and left for a week.    damp iron wool air water     which diagram shows the level of the water at the end of the week?    a b c d       33 which statement about the carbon cycle is correct?  a carbon is absorbed from the atmosphere by combustion and released into it by respiration.  b carbon is absorbed from the atmosphere by photosynthesis and released into it by  combustion.  c carbon is absorbed from the atmosphere by both respiration and combustion.  d carbon is released into the atmosphere by both photosynthesis and respiration.     ",
            "11": "11  \u00a9 ucles 2019 0620/21/o/n/19 [turn over  34 ammonium sulfate is used as a fertiliser.    it is made from ammonia and sulfuric acid.    which words complete gaps 1, 2 and 3?    the ..1.. is made by the ..2.. process in which ..3.. is used as a catalyst.     1 2 3  a ammonia contact iron  b ammonia haber vanadium( v) oxide  c sulfuric acid contact vanadium( v) oxide  d sulfuric acid haber iron      35 which process is used to obtain lime from limestone?  a cracking  b fractional distillation  c neutralisation  d thermal decomposition      36 petroleum is separated by fractional distillation.    which statement about the fractions produced is correct?  a bottled gas for heating and cooking is obtained from the naphtha fraction.  b diesel oil is used as a fuel for jet aircraft.  c substances used to make polishes are obtained from the lubricating fraction.  d the kerosene fraction contains many useful waxes.    37 which products are obtained by the cracking of an alkane?     alkene hydrogen water  a \u0016 \u0016 \u0016  b \u0016 \u0016 \u001a  c \u0016 \u001a \u0016  d \u001a \u0016 \u0016     ",
            "12": "12  \u00a9 ucles 2019 0620/21/o/n/19  38 ethanol is manufactured by the catalytic addition of steam to ethene and by fermentation.    which statement describes an advantage of fermentation compared to the catalytic addition of  steam to ethene?  a fermentation is a more rapid reaction.  b fermentation produces a purer product.  c fermentation uses a higher temperature.  d fermentation uses renewable resources.    39 the diagram shows the structure of a monomer and of the polymer made from it.    nnh hch hch hch hc     what are the monomer and polymer?     monomer polymer  a ethane poly(ethane)  b ethane poly(ethene)  c ethene poly(ethane)  d ethene poly(ethene)      40 which polymers possess the same linkage?  a nylon and protein  b protein and starch  c starch and nylon  d nylon and terylene       ",
            "13": "13  \u00a9 ucles 2019 0620/21/o/n/19 blank page",
            "14": "14  \u00a9 ucles 2019 0620/21/o/n/19  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/21/o/n/19  blank page",
            "16": "16  \u00a9 ucles 2019 0620/21/o/n/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w19_qp_22.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certific ate.  this document consists of 15 printed pages and 1 blank page.  ib19 11_0620_22/4rp  \u00a9 ucles 2019 [turn over     *8743391895* cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/22     paper 2  multiple choice (extended)  october/november 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number  on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/22/o/n/19  1 the rate of diffusion of a gas depends on its molecular mass and the temperature.    which combination of molecular mass and temperature gives the slowest rate of diffusion?     molecular mass temperature  a high high  b high low  c low high  d low low     2 a student is asked to measure the time taken for 0.4  g of magnesium carbonate to react  completely with 25.0  cm3 of dilute hydrochloric acid.    which pieces of apparatus does the student need?  a balance, stop-clock, pipette  b balance, stop-clock, thermometer  c balance, pipette, thermometer  d stop-clock, pipette, thermometer     3 substance q was investigated using chromatography.    the chromatogram is shown. the diagram is not drawn to scale.    q 13 mm83 mm114  mm129  mm baselinesolvent front q     what is the rf value of q?  a 0.60 b 0.64 c 0.69 d 0.72     ",
            "3": "3  \u00a9 ucles 2019 0620/22/o/n/19 [turn over  4 which statement about an ionic compound is not correct?  a it conducts electricity when dissolved in water.  b it has a high melting point due to strong attractive forces between ions.  c it has a regular lattice of oppositely charged ions in a \u2018sea of electrons\u2019.  d the ionic bonds are formed between metallic and non-metallic elements.      5 what is the total number of electrons in one molecule of ammonia, nh 3?  a 6 b 8 c 10 d 11     6 rubidium has two isotopes, rb85 37  and rb8737.    which statement explains why both isotopes have the same chemical properties?  a they  have the same number of protons.  b they  have the same number of outer shell electrons.  c they  have different numbers of neutrons.  d they  have different mass numbers.     7 which statement about the structure and properties of silicon( iv) oxide is not correct?  a it has a giant structure similar to that of diamond.  b it has a high melting point due to the strong attractive force between molecules.  c there are strong covalent bonds between silicon and oxygen.  d there are no free electrons, so silicon (iv) oxide does not conduct electricity.      8 which statement describes the structure of copper?  a it has a lattice of negative ions in a \u2018sea of electrons\u2019.  b it has a lattice of negative ions in a \u2018sea of protons\u2019.  c it has a lattice of positive ions in a \u2018sea of electrons\u2019.  d it has a lattice of positive ions in a \u2018sea of protons\u2019.     9 phosphorus reacts with oxygen to form phosphorus( iii) oxide as shown.    4p(s)  +  3o 2(g)  \u2192  2p 2o3(s)    which mass of phosphorus( iii) oxide is produced from 6.2  g of phosphorus?  a 1.1  g b 5.5  g c 11.0  g d 22.0  g    ",
            "4": "4  \u00a9 ucles 2019 0620/22/o/n/19  10 calcium carbonate is heated. calcium oxide and carbon dioxide gas are formed.    the equation for the reaction is shown.    caco 3  \u2192  cao  +  co 2    225  kg of calcium carbonate is heated until there is no further change in mass.    the yield of calcium oxide is 85  kg.    what is the percentage yield?  a 37.8 % b 47.2 % c 67.5 % d 85.0 %     11 the diagram shows a simple cell.    dilute sulfuric acidmetal q metal pwirevoltmeter     which pair of metals produces the largest voltage?     metal p metal q  a magnesium iron  b magnesium copper  c zinc iron  d zinc copper      12 what are the ionic half-equations for the electrode reactions during the electrolysis of  concentrated aqueous sodium chloride?     anode cathode   a cl 2  +  2e\u2013  \u2192  2c l \u2013 h 2  \u2192  2h+  +  2e\u2013  b 2c l \u2013  \u2192  c l 2  +  2e\u2013 2h+  +  2e\u2013  \u2192  h2  c h2  \u2192  2h+  +  2e\u2013 c l 2  +  2e\u2013  \u2192  2c l \u2013  d 2h+  +  2e\u2013  \u2192  h2 2c l \u2013  \u2192  c l 2  +  2e\u2013     ",
            "5": "5  \u00a9 ucles 2019 0620/22/o/n/19 [turn over  13 the temperature of the water in two beakers, x and y, is measured as 21.5  \u00b0c.    5 g of sodium chloride is dissolved in the water in beaker x. the temperature changes to 18.0  \u00b0c.    5 g of calcium oxide is dissolved in the water in beaker y. the temperature changes to 29.4  \u00b0c.    which types of process are occurring in beakers x and y?     x y  a endothermic endothermic  b endothermic exothermic  c exothermic endothermic  d exothermic exothermic      14 which gases are used to generate electricity in a fuel cell?  a carbon dioxide and oxygen  b hydrogen and methane  c hydrogen and oxygen  d methane and carbon dioxide    15 which row identifies a chemical and a physical change?      chemical change physical change  a boiling ethanol burning ethanol  b burning ethanol evaporating ethanol  c dissolving ethanol in water burning ethanol  d evaporating ethanol dissolving ethanol in water     ",
            "6": "6  \u00a9 ucles 2019 0620/22/o/n/19  16 a sample of dilute nitric acid is added to lumps of limestone in a conical flask. the conical flask is  placed on a balance and the loss in mass is measured.    a second sample of nitric acid of a different concentration is separately tested. all other  conditions are kept the same.    the loss in mass in 1 minute at each concentration of nitric acid is shown.    concentration  in mol  / dm3 loss in mass in  1 minute  / g  0.5 0.15  1.0 0.25    which row describes and explains the results obtained using 1.0  mol  / dm3 nitric acid compared  with 0.5  mol  / dm3 nitric acid?     description explanation  a decrease in reaction rate decrease in particle collision energy  b decrease in reaction rate increase in particle collision rate  c increase in reaction rate increase in particle collision rate  d increase in reaction rate increase in particle collision rate and collision energy     17 when carbon monoxide reacts with hydrogen, methanol is formed.    co(g)  +  2h 2(g)    ch 3oh(g)    the forward reaction is exothermic.    which statements are correct?    1 there are more moles of gas on the left-hand side of the reaction.  2 increasing the temperature increases the amount of methanol at equilibrium.  3 increasing the pressure increases the amount of methanol at equilibrium. 4 increasing the initial amount of hydrogen decreases the amount of methanol at  equilibrium.    a 1 and 2 only b 1 and 3 only c 2 and 4 only d 3 and 4 only     ",
            "7": "7  \u00a9 ucles 2019 0620/22/o/n/19 [turn over  18 in the blast furnace, iron is formed when iron (iii) oxide reacts with carbon monoxide in a redox  reaction.    fe2o3  +  3co  \u2192  2fe  +  3co 2    which substance is the oxidising agent and which substance is the reducing agent?     oxidising agent reducing agent  a co fe 2o3  b co 2 fe  c fe co 2  d fe2o3 co      19 which oxide is classified as an amphoteric oxide?  a aluminium oxide  b calcium oxide  c copper( ii) oxide  d nitrogen oxide    20 which statement describes the properties of hydrochloric acid?  a carbon dioxide is produced when limestone reacts with hydrochloric acid.  b hydrogen is produced when sodium hydrox ide reacts with hydrochloric acid.  c methyl orange turns yellow in strong hydrochloric acid.  d red litmus paper turns blue when dipped into hydrochloric acid.    ",
            "8": "8  \u00a9 ucles 2019 0620/22/o/n/19  21 a method used to make copper( ii) sulfate crystals is shown.    1 place dilute sulfuric acid in a beaker.  2 warm the acid.  3 add copper( ii) oxide until it is in excess.  4 filter the mixture.  5 evaporate the filtrate until crystals start to form.  6 leave the filtrate to cool.    what are the purposes of step 3 and step 4?     step 3 step 4  a to ensure all of the acid has reacted to obtain solid copper( ii) sulfate  b to ensure all of the acid has reacted to remove the excess of copper( ii) oxide c to speed up the reaction to obtain solid copper( ii) sulfate  d to speed up the reaction to remove the excess of copper( ii) oxide     22 lead( ii) sulfate is an insoluble salt.     which reaction produces a mixture from which lead( ii) sulfate is obtained by filtration?  a adding solid lead( ii) carbonate to dilute sulfuric acid   b adding solid lead( ii) hydroxide to dilute sulfuric acid  c adding metallic lead to dilute sulfuric acid  d adding aqueous lead( ii) nitrate to dilute sulfuric acid      23 helium is a noble gas.    which statement about helium is correct?  a it has eight electrons in its outer shell.  b it is a diatomic gas.  c it is reactive.  d it is used for filling balloons.     ",
            "9": "9  \u00a9 ucles 2019 0620/22/o/n/19 [turn over  24 which pair of elements reacts together most violently?  a chlorine and lithium  b chlorine and potassium  c iodine and lithium  d iodine and potassium      25 iron( ii) ions can be oxidised to iron( iii) ions by hydrogen peroxide.    which statement explains why iron is a transition element?  a iron is a transition element because it can be oxidised.  b iron is a transition element because it has variable oxidation states.  c iron is a transition element because it takes part in redox reactions.  d iron is a transition element because it reacts with chlorine.     26 some properties of substance x are listed.    \u25cf it conducts electricity when molten.  \u25cf it has a high melting point.  \u25cf it burns in oxygen and the oxide dissolves in water to give a solution with ph 11.    what is x?  a a covalent compound  b a macromolecule  c a metal  d an ionic compound     27 which row describes the uses of aluminium, copper and mild steel?     aluminium copper mild steel  a aircraft bodies electrical wiring car bodies  b car bodies cooking utensils electrical wiring  c electrical wiring aircraft bodies food containers  d food containers aircraft bodies cooking utensils     ",
            "10": "10  \u00a9 ucles 2019 0620/22/o/n/19  28 the properties of four metals are listed.    \u25cf metal w does not react with dilute hydrochloric acid.  \u25cf metal x reacts with dilute hydrochloric acid.  \u25cf metal y displaces metal x from an aqueous solution of its ions.  \u25cf metal z reacts with water and dilute hydrochloric acid.    what is the order of reactivity of the metals?     most  reactive  least  reactive a w x y z  b w y x z  c z x y w  d z y x w      29 which statement about the extraction of aluminium from aluminium oxide is correct?  a aluminium is formed at the positive electrode during electrolysis.  b pure aluminium oxide is dissolved in molten cryolite.  c pure aluminium oxide is electrolysed us ing aluminium as the positive electrode.  d pure aluminium oxide is heated with carbon to form carbon dioxide and aluminium.    30 river water contains soluble impurities, insoluble impurities and bacteria.    river water is made safe to drink by filtration and chlorination.    which statement is correct?  a filtration removes bacteria and insoluble impurities, and chlorination removes soluble  impurities.  b filtration removes insoluble impurities, and chlorination kills the bacteria.  c filtration removes soluble and insoluble impurities, and chlorination kills the bacteria.  d filtration removes soluble impurities and bacteria, and chlorination removes insoluble  impurities.    ",
            "11": "11  \u00a9 ucles 2019 0620/22/o/n/19 [turn over  31 which process is used to separate  nitrogen and oxygen from air?    a chromatography  b evaporation  c filtration  d fractional distillation    32 the apparatus shown is set up and left for a week.    damp iron wool air water     which diagram shows the level of the water at the end of the week?    a b c d      ",
            "12": "12  \u00a9 ucles 2019 0620/22/o/n/19  33 the diagram represents an outline of the carbon cycle.    carbon dioxide in the atmosphere animals organic wastepower stationsplants fossil fuelsx death and excretiony respirationphotosynthesis     which processes are x and y?      x y  a combustion respiration  b decomposition respiration  c photosynthesis combustion  d respiration combustion      34 ammonium sulfate is used as a fertiliser.    it is made from ammonia and sulfuric acid.    which words complete gaps 1, 2 and 3?    the ..1.. is made by the ..2.. process in which ..3.. is used as a catalyst.     1 2 3  a ammonia contact iron  b ammonia haber vanadium( v) oxide  c sulfuric acid contact vanadium( v) oxide  d sulfuric acid haber iron     ",
            "13": "13  \u00a9 ucles 2019 0620/22/o/n/19 [turn over  35 which statement about limestone and lime is correct?  a limestone combines with water to produce slaked lime.  b lime is obtained from limestone by oxidation.  c lime is used in the desulfurisation of flue gases.  d lime is used in the treatment of alkaline soil.      36 some fractions obtained from petroleum are listed.     fraction use position collected  in the  fractionating column  1 gasoline waxes and polishes below refinery gas  2 bitumen making roads above kerosene  3 kerosene jet fuel below gasoline  4 refinery gas heating and cooking above gasoline    which rows are correct?  a 1, 3 and 4  b 2, 3 and 4  c 3 and 4 only  d 4 only     37 which products are obtained by the cracking of an alkane?     alkene hydrogen water  a \u0016 \u0016 \u0016  b \u0016 \u0016 \u001a  c \u0016 \u001a \u0016  d \u001a \u0016 \u0016     ",
            "14": "14  \u00a9 ucles 2019 0620/22/o/n/19  38 ethanol is produced by fermentation or by the reaction of ethene with steam.    which row is correct?     by fermentation from ethene  a uses a temperature of 100  \u00b0c uses a temperature of 350  \u00b0c  b needs yeast as a catalyst does not need a catalyst  c very slow reaction very fast reaction  d high yield of ethanol low yield of ethanol     39 the diagram shows the structure of a monomer and of the polymer made from it.    nnh hch hch hch hc     what are the monomer and polymer?     monomer polymer  a ethane poly(ethane)  b ethane poly(ethene)  c ethene poly(ethane)  d ethene poly(ethene)     40 the structure of a naturally occurring polymer, x, is shown.    nh nh co co n hc o    what is x?  a an amino acid  b a carbohydrate  c a protein  d a sugar      ",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/22/o/n/19  blank page",
            "16": "16  \u00a9 ucles 2019 0620/22/o/n/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w19_qp_23.pdf": {
            "1": "  this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certific ate.  this document consists of 14 printed pages and 2 blank pages.  ib19 11_0620_23/4rp  \u00a9 ucles 2019 [turn over     *0520730636* cambridge assessment international education  cambridge international general certificate of secondary education       chemistry 0620/23     paper 2  multiple choice (extended)  october/november 2019       45 minutes  additional materials: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       read these instructions first   write in soft pencil.  do not use staples, paper clips, glue or correction fluid.  write your name, centre number and candidate number  on the answer sheet in the spaces provided unless  this has been done for you.  do not  write in any barcodes.   there are forty  questions on this paper. answer all questions. for each question there are four possible  answers a, b, c and d.   choose the one you consider correct and record your choice in soft pencil  on the separate answer sheet.   read the instructions on the answer sheet very carefully.   each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  any rough working should be done in this booklet.  a copy of the periodic table is printed on page 16.  electronic calculators may be used.  ",
            "2": "2  \u00a9 ucles 2019 0620/23/o/n/19  1 which two gases will diffuse at the same rate, at the same temperature?  a carbon monoxide and carbon dioxide  b carbon monoxide and nitrogen  c chlorine and fluorine  d nitrogen and oxygen      2 a student is asked to measure the time taken for 0.4  g of magnesium carbonate to react  completely with 25.0  cm3 of dilute hydrochloric acid.    which pieces of apparatus does the student need?  a balance, stop-clock, pipette  b balance, stop-clock, thermometer  c balance, pipette, thermometer  d stop-clock, pipette, thermometer    3 a substance is separated using chromatography.    the chromatogram is shown.    p q rsolvent front baseline     which statement is not correct?  a p has a higher rf value than q.  b p, q and r are all soluble in the solvent.  c r is the most soluble substance.  d the rf value of p is less than 1.     4 which statement about an ionic compound is not correct?  a it conducts electricity when dissolved in water.  b it has a high melting point due to strong attractive forces between ions.  c it has a regular lattice of oppositely charged ions in a \u2018sea of electrons\u2019.  d the ionic bonds are formed between metallic and non-metallic elements. ",
            "3": "3  \u00a9 ucles 2019 0620/23/o/n/19 [turn over  5 the numbers of protons, neutrons and electrons present in the atoms p, q, r and s are shown.    atom number  of protons number  of neutrons number  of electrons  p 4 5 4  q 5 6 5  r 6 6 6  s 6 7 6    which atoms are isotopes of the same element?  a p and q only b q and r only c r and s only d p and s only     6 carbon has three isotopes,  12c, 13c and 14c.    why do all three isotopes have the same chemical properties?  a they all have the same atomic mass.  b they all have the same number of electrons in their outer shell.  c they all have the same number of electron shells.  d they all have the same number of nucleons.      7 silicon( iv) oxide is a covalently bonded compound.    which statements are correct?    1 silicon atoms form four single bonds in silicon( iv) oxide.  2 oxygen atoms form two double bonds in silicon( iv) oxide.  3 silicon( iv) oxide has a high melting point.  4 silicon( iv) oxide contains one silicon atom and four oxygen atoms.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 3 and 4 only      8 which statement describes the structure of copper?  a it has a lattice of negative ions in a \u2018sea of electrons\u2019.  b it has a lattice of negative ions in a \u2018sea of protons\u2019.  c it has a lattice of positive ions in a \u2018sea of electrons\u2019.  d it has a lattice of positive ions in a \u2018sea of protons\u2019.     ",
            "4": "4  \u00a9 ucles 2019 0620/23/o/n/19  9 magnesium carbonate decomposes on heating to form magnesium oxide and carbon dioxide as  shown.    mgco 3  \u2192  mgo  +  co 2    how much magnesium carbonate is needed to make 5.0  g of magnesium oxide?  a 3.5  g b 4.0  g c 6.5  g d 10.5  g    10 90  g of glucose is dissolved in water.    the glucose solution is fermented.    c6h12o6  \u2192   2co 2  +  2c 2h5oh   glucose, mr = 180 ethanol, mr = 46    after the fermentation finishes, 6.8  g of ethanol is obtained from the solution.    what is the percentage yield of ethanol?  a 7.4 b 7.6 c 14.8 d 29.6    11 the diagram shows a simple cell.    dilute sulfuric acidcopper metal pwirevoltmeter     which metal p produces the smallest voltage?  a calcium  b iron  c magnesium  d zinc    ",
            "5": "5  \u00a9 ucles 2019 0620/23/o/n/19 [turn over  12 what are the ionic half-equations for the electrode reactions during the electrolysis of  concentrated aqueous sodium chloride?     anode cathode   a cl 2  +  2e\u2013  \u2192  2c l \u2013 h 2  \u2192  2h+  +  2e\u2013  b 2c l \u2013  \u2192  c l 2  +  2e\u2013 2h+  +  2e\u2013  \u2192  h2  c h2  \u2192  2h+  +  2e\u2013 c l 2  +  2e\u2013  \u2192  2c l \u2013  d 2h+  +  2e\u2013  \u2192  h2 2c l \u2013  \u2192  c l 2  +  2e\u2013     13 an energy level diagram for a reaction is shown.    energy progress of reaction    which statement and explanation about this reaction are correct?     statement explanation  a the reaction is endothermic the products have more energy than the reactants  b the reaction is endothermic the products have less energy than the reactants  c the reaction is exothermic the products have more energy than the reactants  d the reaction is exothermic the products  have less energy than the reactants      14 which gases are used to generate electricity in a fuel cell?  a carbon dioxide and oxygen  b hydrogen and methane  c hydrogen and oxygen  d methane and carbon dioxide    ",
            "6": "6  \u00a9 ucles 2019 0620/23/o/n/19  15 a sequence of changes involving sulfur is shown.    s(s)change 1s(l) so2(g)change 2     which row describes the changes?     change 1 change 2  a chemical chemical  b chemical physical  c physical chemical  d physical physical      16 magnesium reacts with dilute hydrochloric acid.    which statement about the particles in the reaction is correct?  a increasing the concentration of dilute hydrochloric  acid increases the collision rate but has no  effect on the activation energy.  b increasing the concentration of dilute hydrochloric acid increases the collision rate and the  activation energy.  c increasing the temperature of the reaction increases the activation energy.  d increasing the temperature of the reaction causes all collisions to lead to a reaction.    17 two molecules of nitrogen dioxide combine in a reversible reaction to form dinitrogen tetroxide.    the forward reaction is exothermic.    2no 2(g)    n2o4(g)    which changes in reaction conditions would both  increase the amount of dinitrogen tetroxide at  equilibrium?  a decreasing the temperature and decreasing the pressure  b decreasing the temperature and increasing the pressure  c increasing the temperature and decreasing the pressure  d increasing the temperature and increasing the pressure    ",
            "7": "7  \u00a9 ucles 2019 0620/23/o/n/19 [turn over  18 chlorine displaces bromine from aqueous potassium bromide.    the ionic equation for the reaction is shown.    cl 2  +  2br\u2013  \u2192  2c l \u2013  +  br 2    which statement about this reaction is correct?  a bromide ions act as an oxidising agent.  b bromide ions are oxidised when electrons are lost.  c chlorine acts as a reducing agent.  d chlorine is reduced when electrons are lost.      19 which substance is a neutral oxide?  a aluminium oxide  b carbon monoxide  c sulfur dioxide  d zinc oxide      20 which statements about dilute sulfuric acid are correct?    1 it turns red litmus paper blue.  2 it reacts with magnesium( ii) oxide to form magnesium( ii) sulfate and water.  3 it reacts with magnesium to form magnesium( ii) sulfate and carbon dioxide.  4 its ph is below ph 7.    a 1 and 2 only b 1 and 3 only c 2 and 4 only d 3 and 4 only    ",
            "8": "8  \u00a9 ucles 2019 0620/23/o/n/19  21 a method used to make copper( ii) sulfate crystals is shown.    1 place dilute sulfuric acid in a beaker.  2 warm the acid.  3 add copper( ii) oxide until it is in excess.  4 filter the mixture.  5 evaporate the filtrate until crystals start to form.  6 leave the filtrate to cool.    what are the purposes of step 3 and step 4?     step 3 step 4  a to ensure all of the acid has reacted to obtain solid copper( ii) sulfate  b to ensure all of the acid has reacted to remove the excess of copper( ii) oxide c to speed up the reaction to obtain solid copper( ii) sulfate  d to speed up the reaction to remove the excess of copper( ii) oxide     22 lead (ii) iodide is formed as a precipitate in the reaction shown.    pb(no 3)2(aq)  +  2na i(aq)  \u2192  pb i2(s)  +  2nano 3(aq)    which method is used to separate the lead (ii) iodide from the mixture?  a crystallisation  b distillation  c evaporation  d filtration    23 which statement describes a gas which is in group viii of the periodic table?  a a colourless gas that helps substances burn.  b a pollutant gas present in car exhausts.  c a gas that is less dense than air and makes a \u2018pop\u2019 sound with a lighted splint.  d a gas that is used in lamps.    ",
            "9": "9  \u00a9 ucles 2019 0620/23/o/n/19 [turn over  24 which pair of elements reacts together most violently?  a chlorine and lithium  b chlorine and potassium  c iodine and lithium  d iodine and potassium      25 iron reacts with dilute hydrochloric acid to form iron( ii) chloride, fec l 2. iron reacts with chlorine  to form iron( iii) chloride, fec l 3.    which property of transition elements is shown by this information?  a transition elements have high melting points.  b transition elements can act as catalysts.  c transition elements have variable oxidation states.  d transition elements have coloured compounds.     26 some properties of substance x are listed.    \u25cf it conducts electricity when molten.  \u25cf it has a high melting point.  \u25cf it burns in oxygen and the oxide dissolves in water to give a solution with ph 11.    what is x?  a a covalent compound  b a macromolecule  c a metal  d an ionic compound      27 which statement about metals and their uses is correct?  a aluminium is used in the manufacture of aircraft because it has a high density.  b copper is used to make cooking utensils because it is a poor conductor of heat.  c mild steel is used to make car bodies because it is brittle and breaks easily.  d stainless steel is used to make cutlery because it is resistant to corrosion.     ",
            "10": "10  \u00a9 ucles 2019 0620/23/o/n/19  28 which word equation represents a reaction which occurs?  a sodium oxide  +  carbon  \u2192  sodium  +  carbon dioxide  b sodium oxide  +  iron  \u2192  sodium  +  iron (ii) oxide  c iron (ii) oxide  +  copper  \u2192  iron  +  copper (ii) oxide  d iron (iii) oxide  +  carbon  \u2192  iron  +  carbon dioxide      29 why is cryolite used in the extraction of aluminium by electrolysis?  a it changes bauxite to aluminium oxide.  b it decreases the melting point of the aluminium.  c it dissolves the aluminium oxide.  d it protects the anodes from corrosion.    30 river water contains soluble impurities, insoluble impurities and bacteria.    river water is made safe to drink by filtration and chlorination.    which statement is correct?  a filtration removes bacteria and insoluble impurities, and chlorination removes soluble  impurities.  b filtration removes insoluble impurities, and chlorination kills the bacteria.  c filtration removes soluble and insoluble impurities, and chlorination kills the bacteria.  d filtration removes soluble impurities and bacteria, and chlorination removes insoluble  impurities.     31 how are oxygen and nitrogen separated from air?  a chromatography  b condensation and filtration  c crystallisation  d fractional distillation    ",
            "11": "11  \u00a9 ucles 2019 0620/23/o/n/19 [turn over  32 the apparatus shown is set up and left for a week.    damp iron wool air water     which diagram shows the level of the water at the end of the week?    a b c d       33 the following processes are part of the carbon cycle.    1 photosynthesis  2 combustion  3 respiration    which processes decrease the amount of carbon dioxide in the atmosphere?  a 1 only b 1 and 2 only c 1 and 3 only d 2 and 3 only    ",
            "12": "12  \u00a9 ucles 2019 0620/23/o/n/19  34 ammonium sulfate is used as a fertiliser.    it is made from ammonia and sulfuric acid.    which words complete gaps 1, 2 and 3?    the ..1.. is made by the ..2.. process in which ..3.. is used as a catalyst.     1 2 3  a ammonia contact iron  b ammonia haber vanadium( v) oxide  c sulfuric acid contact vanadium( v) oxide  d sulfuric acid haber iron      35 which type of reaction occurs when lime is manufactured from limestone?  a combustion  b neutralisation  c redox  d thermal decomposition      36 which statement is correct?  a bitumen is used as a fuel for ships.  b coal, natural gas and oxygen are all fuels.  c hydrogen is the main constituent of natural gas.  d petroleum is separated into useful substances by fractional distillation.      37 which products are obtained by the cracking of an alkane?     alkene hydrogen water  a \u0016 \u0016 \u0016  b \u0016 \u0016 \u001a  c \u0016 \u001a \u0016  d \u001a \u0016 \u0016     ",
            "13": "13  \u00a9 ucles 2019 0620/23/o/n/19  38 ethanol is made by fermentation of sugars and by the catalytic addition of steam to ethene.    what are two advantages of making ethanol by the catalytic addition of steam to ethene rather  than by fermentation of sugars?  a faster reaction and renewable raw materials  b purer product and faster reaction  c renewable raw materials and continuous process  d uses more energy and forms a purer product    39 the diagram shows the structure of a monomer and of the polymer made from it.    nnh hch hch hch hc     what are the monomer and polymer?     monomer polymer  a ethane poly(ethane)  b ethane poly(ethene)  c ethene poly(ethane)  d ethene poly(ethene)     40 proteins and starch are both natural polymers.    both proteins and starch are hydrolysed by dilute acids.    what are the products of hydrolysis of proteins and of starch?     products of  hydrolysis of proteins products of  hydrolysis of starch  a amines and carboxylic acids simple sugars  b amines and carboxylic acids alcohols and carboxylic acids  c amino acids simple sugars  d amino acids alcohols and carboxylic acids       ",
            "14": "14  \u00a9 ucles 2019 0620/23/o/n/19  blank page",
            "15": "15    permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2019 0620/23/o/n/19  blank page",
            "16": "16  \u00a9 ucles 2019 0620/23/o/n/19   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w19_qp_31.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/31 paper 3  theory (core) october/november 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 15 printed pages and 1 blank page. [turn overib19 11_0620_31/3rp\u00a9 ucles 2019 *6072633725* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/31/o/n/19 \u00a9 ucles 2019 1  this question is about solids, liquids and gases.  (a)  the list gives the names of nine substances which are solids at room temperature. a ceramic aluminium anhydrous cobalt( ii) chloride anhydrous copper( ii) sulfate calcium oxide graphite iodine iron sodium   answer the following questions about these substances.   each substance may be used once, more than once or not at all.   state which substance:  (i)  turns pink when water is added to it   ...   [1]  (ii)  is a non-metal which is used as a lubricant   ...   [1]  (iii)  is used to neutralise acidic industrial waste   ...   [1]  (iv)  is extracted from bauxite   ...   [1]  (v)  is used as an electrical insulator.   ...   [1]",
            "3": "3 0620/31/o/n/19 \u00a9 ucles 2019 [turn over  (b)  some changes of state of sodium are shown. solid sodiumliquid sodiumsodium gasa freezing bevaporation  (i)  state the names of the changes of state represented by a and b.  a  .  b  .  [2]  (ii)  use the kinetic particle model to describe the arrangement and separation of the particles  in:  solid sodium     .   .  liquid sodium.  ..   .   .  [4] [total: 11]",
            "4": "4 0620/31/o/n/19 \u00a9 ucles 2019 2  biogas is made by fermenting animal and vegetable waste.  (a)  the table shows the percentage composition of the gases present in a sample of biogas. substance presentpercentage present in biogas carbon dioxide 28.5 hydrogen 1.0 methane 62.0 nitrogen water vapour 2.4 other substances 0.1 total 100.0   deduce the percentage of nitrogen present in this sample of biogas.   ..   [1]  (b) (i)  balance the chemical equation for the complete combustion of methane.  ch4  +  .o2    co2  +  .h2o [2]  (ii)  which one of these compounds belongs to the same homologous series as methane?   draw a circle around the correct answer.  methanoic acid       methanol       propane       propanol       propene  [1]  (iii)\t\tmethane\t is\tpresent\tin\tthe\trefinery\tgas\tfraction\tproduced\t by\tthe\tfractional\t distillation\t of\t petroleum.   match the fractions on the left with their uses on the right. \t \tthe\tfirst\tone\thas\tbeen\tdone\tfor\tyou. fraction use refinery\tgas making roads fuel oil fraction making chemicals bitumen fuel for heating and cooking naphtha fraction fuel for ships  [2]",
            "5": "5 0620/31/o/n/19 \u00a9 ucles 2019 [turn over  (c) (i)  draw a dot-and-cross diagram to show the electron arrangement in a molecule of hydrogen.  [1]  (ii)  state one use of hydrogen.   ...   [1]  (d)  the biogas contains a small amount of compound c.   the structure of compound c is shown. hh hcch s hhoo hn c  (i)  on the structure shown, draw a circle around the carboxylic acid functional group. [1]  (ii)  how many different types of atoms are present in compound c?   ...   [1]  (e)  describe the manufacture of ethanol by fermentation.   in your answer include:  \u25cf the names of the substances needed for fermentation  \u25cf the conditions needed for fermentation.                        ..   [4]  [total: 14]",
            "6": "6 0620/31/o/n/19 \u00a9 ucles 2019 3  a student investigated the reaction between zinc carbonate and an excess of dilute hydrochloric acid. znco3  +  2hcl    zncl 2  +  co2  +  h2o   the rate of reaction can be found by measuring the decrease in the mass of the reaction mixture  over time.  (a)  describe one other practical method for measuring the rate of this reaction.               ..   [3]  (b)  when 6.25 g of zinc carbonate is used, 2.20 g of carbon dioxide is formed.   calculate the mass of zinc carbonate that forms 11.00 g of carbon dioxide.  mass of zinc carbonate = .. g  [1]  (c)  what effect do the following have on the rate of this reaction?  \u25cf decreasing the temperature of the reaction mixture.   all other conditions are kept the same.     \u25cf increasing the concentration of hydrochloric acid.   all other conditions are kept the same.     [2]  (d)  carbon dioxide is formed:  \u25cf when an acid reacts with a carbonate  \u25cf as a product of the complete combustion of carbon-containing substances.   state two other sources of carbon dioxide.  1  .  2  .  [2]  [total: 8]",
            "7": "7 0620/31/o/n/19 \u00a9 ucles 2019 [turn over 4  an isotope of sodium is written as shown. 23na11  (a) (i)  deduce the number of protons, electrons and neutrons in this isotope of sodium.  number of protons  ..  number of electrons    number of neutrons    [3]  (ii)  state one medical use of radioactive isotopes.   ...   [1]  (b) (i)  draw the electronic structure of a sodium atom.  [2]  (ii)  state the name of the particle which is lost when a sodium atom forms a sodium ion.   ...   [1]",
            "8": "8 0620/31/o/n/19 \u00a9 ucles 2019  (c)  sodium reacts with water to form:  \u25cf an alkaline solution  \u25cf a gas which \u2018pops\u2019 with a lighted splint.  (i)  complete the word equation for the reaction of sodium with water. sodium + water.. ..+..  [2] (ii)  the reaction of sodium with water is exothermic.   what is meant by the term exothermic ?   .   ...   [1]  (iii)  sodium reacts with oxygen to form sodium oxide.   is sodium oxide an acidic oxide or a basic oxide?   give a reason for your answer.   .   ...   [1]  (d)  the table shows some observations for the reaction of four metals with cold water and with hot  water. metal reaction with cold water reaction with hot water calcium bubbles form rapidly bubbles form very rapidly lanthanum bubbles form slowly bubbles form very rapidly manganese no bubbles form bubbles form very slowly uranium bubbles form slowly bubbles form rapidly   use this information to put the four metals in order of their reactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]  [total: 13]",
            "9": "9 0620/31/o/n/19 \u00a9 ucles 2019 [turn over 5  this question is about the halogens and compounds of the halogens.  (a)  the properties of some halogens are shown in the table. elementmelting point in \u00b0cboiling point in \u00b0cdensity of liquid at its  boiling point in g / cm3atomic radius in nm chlorine \u2013101 \u2013350.099 bromine \u20137 59 3.12 0.114 iodine 1144.93 0.133 astatine 302 337 6.35  (i)  complete the table to estimate:  \u25cf the density of liquid chlorine  \u25cf the boiling point of iodine.  [2]  (ii)  describe the trend in the atomic radius of the halogens down the group.   ...   [1]  (iii)  predict the physical state of bromine at 50 \u00b0c.  give a reason for your answer.   .   .   ...   [2]  (b)  bromine reacts with an aqueous potassium salt to form iodine and a different potassium salt.   complete the word equation for this reaction. bromine +.. ..iodine +  [2]",
            "10": "10 0620/31/o/n/19 \u00a9 ucles 2019  (c)  fluorine is above chlorine in group vii of the periodic table.  (i)  explain, using ideas about the reactivity of the halogens, why chlorine does not react with  aqueous\tsodium\tfluoride.   .   ...   [1]  (ii)\t\tbalance\tthe \tchemical\tequation\tfor\tthe\treaction\tof\tfluorine\twith\tammonia.  .nh3  +  .f2    n2  +  6hf [2]  (iii)\t\ta\tcompound\tof\tfluorine\thas\tthe\tformula\t xeo3f2. \t \tcomplete\tthe\ttable\tto\tcalculate\tthe\trelative\tmolecular\tmass\tof\txeo3f2.   use your periodic table to help you. type of atomnumber of atomsrelative atomic mass xenon oxygen 3 16 3 \u00d7 16 = 48 fluorine  relative molecular mass = ..  [2]  (iv)\t\tthe\tcompound\txeo3f2 readily undergoes reduction.  what is meant by the term reduction ?   ...   [1]  [total: 13]",
            "11": "11 0620/31/o/n/19 \u00a9 ucles 2019 [turn over 6  this question is about ammonia.  (a)  when ammonia gas reacts with hydrogen chloride gas, white fumes of ammonium chloride are  formed. nh3  +  hcl    nh4cl  (i)  what type of chemical reaction is this?   draw a circle around the correct answer.  decomposition       neutralisation       oxidation       reduction  [1]  (ii)  watch-glasses of aqueous ammonia and concentrated hydrochloric acid were placed near  each other on a table. \t \tat\tfirst\tno\twhite\tfumes\twere\tseen.   after a short time, white fumes were seen between the watch-glasses. watch-glass of ammoniawatch-glass of hydrochloric acid at the start a short time laterdense white fumes   explain these observations using the kinetic particle model.   .   .   .   .   .   ...   [3]  (b)  ammonia is used in the manufacture of fertilisers.   name the three elements present in most fertilisers which improve plant growth.  1  .  2  .  3  .  [3]",
            "12": "12 0620/31/o/n/19 \u00a9 ucles 2019  (c)  aqueous ammonia can be used to test for aluminium ions and zinc ions.   complete the table to show the expected observations. ionobservation on adding a small volume of aqueous ammoniaobservation on adding an excess of aqueous ammonia aluminium (a l 3+) zinc (zn2+)  [3]  [total: 10]",
            "13": "13 0620/31/o/n/19 \u00a9 ucles 2019 [turn over 7 (a)  magnesium is manufactured by the electrolysis of molten magnesium chloride.  (i)  the negative electrode is made of iron.   suggest a non-metal which could be used for the positive electrode.   give a reason for your answer.   .   ...   [2]  (ii)  predict the products of the electrolysis of molten magnesium chloride at:  the positive electrode  ..  the negative electrode.  ...  [2]  (b)  the following statements are about the procedure for making crystals of hydrated  magnesium chloride from magnesium and dilute hydrochloric acid.  a leave the mixture until no more bubbles are seen.  b leave the mixture at room temperature to form more crystals.  c add an excess of magnesium to dilute hydrochloric acid.  d\t warm\tthe\tfiltrate\tto\tthe\tpoint\tof\tcrystallisation.  e\t filter\toff\tthe\tcrystals\tand\tdry\tbetween\tfilter\tpapers.  f filter off the excess magnesium.   put the statements a, b, c, d, e and f in the correct order. \t \tthe\tfirst\tone\thas\tbeen\tdone\tfor\tyou. c  [2]  (c)  magnesium is a metal in group ii of the periodic table.   copper is a transition element.   copper has a higher melting point and a higher boiling point than magnesium.   describe two other properties of copper which are different from those of magnesium.  1  .  2  .  [2]",
            "14": "14 0620/31/o/n/19 \u00a9 ucles 2019  (d)  chromatography can be used to separate a mixture of ions from different transition element  compounds.   four samples, r, s, t and u, each containing transition element ions, were placed on a piece  of chromatography paper.   two solutions, y and z, each containing only one type of transition element ion were also  placed on the same piece of chromatography paper.   the results of the chromatography are shown. rstuyz  (i)  which sample, r, s, t or u, contains the same ions as both solution y and solution z?   ...   [1]  (ii)  which sample, r, s, t or u, does not contain the same ions as either solution y or  solution z?   ...   [1]  (iii)  in which sample, r, s, t or u, has the greatest number of transition element ions been  separated?   ...   [1]  [total: 11]",
            "15": "15 0620/31/o/n/19 \u00a9 ucles 2019blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "16": "16 0620/31/o/n/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w19_qp_32.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/32 paper 3  theory (core) october/november 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib19 11_0620_32/4rp\u00a9 ucles 2019 *0980516384* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/32/o/n/19 \u00a9 ucles 2019 1  this question is about solids, liquids and gases.  (a)  the list gives the names of nine substances. aqueous copper( ii) sulfate aqueous potassium manganate( vii) aqueous sodium chloride dilute hydrochloric acid ethanol hexene mercury octane water   answer the following questions about these substances.   each substance may be used once, more than once or not at all.   state which substance:  (i)  is an alkane   ...   [1]  (ii)\t\tis\tused,\twhen\tacidified,\tto\ttest\tfor\tsulfur\tdioxide   ...   [1]  (iii)  turns blue litmus red   ...   [1]  (iv)\t\treacts\twith\tsodium\tto\tproduce\tonly\taqueous\tsodium\thydroxide\tand\thydrogen   ...   [1]  (v)  is produced by the addition of steam to ethene.   ...   [1]",
            "3": "3 0620/32/o/n/19 \u00a9 ucles 2019 [turn over  (b)  some changes of state of mercury are shown. solid mercuryliquid mercurymercury gasmelting a bevaporation  (i)  state the names of the changes of state represented by a and b.  a  .  b  .  [2]  (ii)  use the kinetic particle model to describe the motion and separation of the particles in:  liquid mercury  .   .   .  mercury gas.  ...   .   .  [4]  [total: 11]",
            "4": "4 0620/32/o/n/19 \u00a9 ucles 2019 2  biogas is made by fermenting animal and vegetable waste.  (a)  the table shows the percentage composition of the gases present in a sample of biogas. substance presentpercentage present in biogas carbon\tdioxide hydrogen 1.0 methane 61.5 nitrogen 8.5 water vapour 2.2 other substances 0.1 total 100.0 \t \tdeduce\tthe\tpercentage\tof\tcarbon\tdioxide\tpresent\tin\tthis\tsample\tof\tbiogas.   ..   [1]  (b) (i)\t \tduring\tthe\tfermentation,\t carbon\tdioxide\treacts\twith\thydrogen\t to\tproduce\t methane\t and\t water.   complete the chemical equation for this reaction.  co2  +  .h2    ch4  +  .h2o [2]  (ii)  methane and ethane are in the same homologous series.   what is meant by the term homologous series?   .   .   ...   [2]  (iii)  draw a dot-and-cross diagram to show the electron arrangement in a molecule of methane,  ch4. show outer shell electrons only.  [2]",
            "5": "5 0620/32/o/n/19 \u00a9 ucles 2019 [turn over  (c)\t\thelium\tand\thydrogen\tcan\tboth\tbe\tused\tto\tfill\tballoons.   suggest one\tadvantage\tof\tusing\thelium\trather\tthan\thydrogen\tto\tfill\tballoons.   ..   [1]  (d)\t\tthe\tbiogas\tfermentation\tmixture\tcontains\ta\tsmall\tamount\tof\tcompound\t c.   the structure of compound c is shown. c hc hhh hhh hh o h c cc ss c  (i)  on the structure shown, draw a circle around a functional group which reacts with  aqueous bromine. [1]  (ii)  how many different types of atoms are present in compound c?   ...   [1]  (e)\t\tethanol\tis\tproduced\tby\tfermentation\tof\ta\tmixture\tof \tplant\tsugars. \t \tdescribe\t how\tethanol\tcan\tbe\tseparated\t from\tthe\trest\tof\tthe\tfermentation\t mixture\tby\tfractional\t distillation.   in your answer:  \u25cf describe how to do the fractional distillation  \u25cf\texplain\thow\tethanol\tis\tseparated\t from\tthe\trest\tof\tthe\tfermentation\t mixture\tusing\tfractional\t distillation.                        ..   [4]  [total: 14]",
            "6": "6 0620/32/o/n/19 \u00a9 ucles 2019 3 (a)\t \ta\tstudent\tinvestigated\t the\treaction\tof\tcalcium\tcarbonate\t with\tan\texcess\tof\tdilute\thydrochloric\t acid\t by\tmeasuring\tthe\tvolume\tof\tcarbon\tdioxide\tproduced\tat\t10\tsecond\tintervals. caco3  +  2hcl    cacl 2  +  co2  +  h2o   the results are shown on the graph. 60 50 40 30 20 10 0 01 02 03 04 05 0 time  / svolume of carbon dioxide gas  / cm3 60 70 80 90pqrs  (i)\t\thow\tlong\tdid\tit\ttake\tfrom\tthe\tstart\tof\tthe \texperiment\tto\tcollect\t30\t cm3\tof\tcarbon\tdioxide?  .. s  [1]  (ii)  at which point on the graph, p, q, r or s, was the rate of reaction fastest? \t \tuse\tthe\tgraph\tto\texplain\tyour\tanswer.   .   ...   [2]  (iii)  when 0.225 g of calcium carbonate is used, 54.0 cm3\tof\tcarbon\tdioxide\tis\tformed.   determine the mass of calcium carbonate needed to form 216 cm3\tof\tcarbon\tdioxide.  mass of calcium carbonate = .. g  [1]",
            "7": "7 0620/32/o/n/19 \u00a9 ucles 2019 [turn over  (iv)  what effect do the following have on the rate of this reaction? \t \u25cf\t\tincreasing\tthe\ttemperature\tof\tthe\treaction\tmixture.   all other conditions are kept the same.   . \t \u25cf\t\tusing\tlarger\tpieces\tof\tcalcium\tcarbonate.   all other conditions are kept the same.   .  [2]  (b)\t\tin\tindustry,\tcalcium\toxide\tis\tmade\tfrom\tcalcium\tcarbonate\tby\tthermal\tdecomposition.  heatcaco3    cao  +  co2  (i)  why is this described as thermal decomposition ?   .   ...   [2]  (ii)  state one other use of calcium carbonate in industry.   ...   [1]  (iii)\t\tcalcium\toxide\tis\tused\tto\ttreat\tacidic\tindustrial\twaste.   state the type of chemical reaction that occurs.   ...   [1]  [total: 10]",
            "8": "8 0620/32/o/n/19 \u00a9 ucles 2019 4  an isotope of calcium is written as shown.  (a) (i)  deduce the number of protons, electrons and neutrons in this isotope of calcium.  number of protons  ..  number of electrons    number of neutrons    [3]  (ii)  state one industrial use of radioactive isotopes.   ...   [1]  (b)  draw the electronic structure of a calcium atom.  [2]  (c)  the table shows some information about the reaction of four metals with dry air at room  temperature and on heating. metalreaction with dry air at room temperaturereaction with dry air on heating iron no reactiononly burns when in the form of\ta\tfine\twire\tor\tpowder copper no reactiondoes not burn but the surface\toxidises\tslowly samarium surface\toxidises\tslowly burns easily sodium surface\toxidises\trapidly burns easily   use this information to put the four metals in order of their reactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]  [total: 8]",
            "9": "9 0620/32/o/n/19 \u00a9 ucles 2019 [turn over 5  this question is about the halogens and compounds of the halogens.  (a)  the properties of some halogens are shown in the table. elementmelting point in \u00b0cboiling point in \u00b0cdensity of liquid at boiling point in g / cm3 colour fluorine \u2013220 \u2013188 1.51 chlorine \u20131011.56 light green bromine \u20137 59 3.12 red-brown iodine 114 184grey-black  (i)  complete the table to estimate:  \u25cf the boiling point of chlorine  \u25cf the density of iodine.  [2]  (ii)  describe the trend in the melting points of the halogens down the group.   ...   [1]  (iii)  predict the physical state of bromine at \u201320 \u00b0c.   ...   [1]  (iv)  which one\tof\tthe\tfollowing\tis\tmost\tlikely \tto\tbe\tthe\tcolour\tof\tfluorine?   tick one\tbox.  dark green  light grey-black  light yellow  purple  [1]",
            "10": "10 0620/32/o/n/19 \u00a9 ucles 2019  (b)  chlorine reacts with an aqueous potassium salt to form iodine and a different potassium salt.  (i)  complete the word equation for this reaction. chlorine +.. ..iodine +  [2] (ii)\t\twhen\taqueous\tsodium\tfluoride\tis\tadded \tto\tchlorine,\tno\treaction\toccurs. \t \texplain,\tusing\tideas\tabout\tthe\treactivity \tof\tthe\thalogens,\twhy\tno reaction occurs.   .   ...   [1]  (iii)  state one use of chlorine.   ...   [1]  (c)  aqueous silver nitrate is used to test for chloride ions and iodide ions.  (i)\t\tthe\tsolutions\tare\tfirst\tacidified\twith\tdilute\tnitric\tacid. \t \texplain\twhy\tdilute\thydrochloric\tacid\tis\t not used to acidify the solutions.   ...   [1]  (ii)\t\tcomplete\tthe\ttable\tto\tshow\tthe\texpected\tobservations. ionobservations on adding aqueous silver nitrate chloride (c l \u2013) iodide ( i\u2013)  [3]",
            "11": "11 0620/32/o/n/19 \u00a9 ucles 2019 [turn over  (d)  a compound of chlorine has the formula c6h4cl 2.   complete the table to calculate the relative molecular mass of c6h4cl 2.   use your periodic table to help you. type of atomnumber of atomsrelative atomic mass carbon 6 12 6 \u00d7 12 = 72 hydrogen chlorine  relative molecular mass = ..  [2]  [total: 15]",
            "12": "12 0620/32/o/n/19 \u00a9 ucles 2019 6  this question is about compounds of nitrogen.  (a)  aqueous ammonia is alkaline.  (i)  which one of the following ph values could be the ph of aqueous ammonia?   draw a circle around the correct answer.  ph 1          ph 5          ph 7          ph 9  [1]  (ii)  ammonia has a strong smell.   a beaker of aqueous ammonia was placed in front of a class of students. \t \tat\tfirst,\tthe\tstudents\tat\tthe\tback\tof\tthe\tclass\tcould\tnot\tsmell\tthe\tammonia.   after a few minutes they could smell the ammonia. \t \texplain\tthese\tobservations\tusing\tthe\tkinetic\tparticle\tmodel.   .   .   .   .   ...   [3]  (b)  ammonia is used in the manufacture of nitric acid.  (i)\t\tbalance\tthe \tchemical\tequation\tfor\tthe\tfirst\tstep\tin\tthe\tprocess.  4nh3  +  5o2    .no  +  6h2o [1]  (ii)\t\tthe\treaction\tis\texothermic.   what is meant by the term exothermic ?   .   ...   [1]  (iii)\t\tthe\tno\tproduced\t in\tthe\tfirst\tstep\tthen\treacts\twith\toxygen\tto\tproduce\t nitrogen\t dioxide,\t no2. 2no  +  o2    2no2 \t \thow\tdoes\tthis\tequation\tshow\tthat\tno\tis \toxidised?   .   ...   [1]  (iv)\t\tis\tnitrogen\tdioxide\tan\tacidic\toxide\tor\ta\tbasic\toxide?   give a reason for your answer.   .   ...   [1]",
            "13": "13 0620/32/o/n/19 \u00a9 ucles 2019 [turn over  (c)\t\toxides\tof\tnitrogen\tare\tatmospheric\tpollutants.   state one\tadverse\teffect\tof\toxides\tof\tnitrogen\ton\thealth.   ..   [1]  (d)  ammonia reacts with nitric acid to form a salt which is present in many fertilisers.   name the salt formed when ammonia reacts with nitric acid.   ..   [1]  [total: 10]",
            "14": "14 0620/32/o/n/19 \u00a9 ucles 2019 7 (a)  concentrated hydrochloric acid is electrolysed using graphite electrodes.  (i)  name the products of this electrolysis at:  the positive electrode  ..  the negative electrode.  ...  [2]  (ii)  suggest one observation that is made at the negative electrode.   ...   [1]  (b)  dilute hydrochloric acid reacts with zinc.   complete the word equation for this reaction. zinc +hydrochloric acid+..  [2]  (c)  the following statements are about the procedure for making crystals of hydrated zinc sulfate  from zinc and dilute sulfuric acid.  a\t\twarm\tthe\tmixture\tuntil\tno\tmore\tbubbles \tare\tseen.  b\t\tadd\texcess\tzinc\tto\tdilute\tsulfuric\tacid.  c\t\twarm\tthe\tfiltrate\tto\tthe\tpoint\tof\tcrystallisation.  d\t\tleave\tthe\tmixture\tat\troom\ttemperature\t to\tform\tmore\tcrystals.  e\t\tfilter\toff\tthe\texcess\tzinc.  f\t\tfilter\toff\tthe\tcrystals\tand\tdry\tbetween\tfilter\tpapers.   put the statements a, b, c, d, e and f in the correct order. \t \tthe\tfirst\tone\thas\tbeen\tdone\tfor\tyou. b  [2]",
            "15": "15 0620/32/o/n/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (d) zinc is a metal.  (i)  describe three physical properties which are characteristic of metals.  1  ..  2  ..  3  ..  [3]  (ii)  an alloy of zinc, copper and nickel is used to make coins.   suggest two reasons why an alloy is used to make coins and not pure copper alone.  1  ..  2  ..  [2]  [total: 12]",
            "16": "16 0620/32/o/n/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w19_qp_33.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 20.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/33 paper 3  theory (core) october/november 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 17 printed pages and 3 blank pages. [turn overib19 11_0620_33/3rp\u00a9 ucles 2019 *4655089752* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/33/o/n/19 \u00a9 ucles 2019 1  this question is about solids and gases.  (a)  the list gives the names of eight substances which are gases at room temperature. ammonia butane carbon dioxide carbon monoxide chlorine methane propene sulfur dioxide   answer the following questions about these gases.   each gas may be used once, more than once or not at all.   state which gas:  (i)  is a poisonous product formed by the incomplete combustion of carbon   ...   [1]  (ii)  is an alkene   ...   [1]  (iii)  is formed when limestone is thermally decomposed   ...   [1]  (iv)  is an element   ...   [1]  (v)  causes acid rain.   ...   [1]",
            "3": "3 0620/33/o/n/19 \u00a9 ucles 2019 [turn over  (b)  when a piece of solid carbon dioxide is placed in a warm room, it undergoes sublimation.  (i)  what is meant by the term sublimation ?   .   ...   [2]  (ii)  use the kinetic particle model to describe the motion and separation of the particles in:  solid carbon dioxide     .   .  carbon dioxide gas.     .   .  [4]  [total: 11]",
            "4": "4 0620/33/o/n/19 \u00a9 ucles 2019 2  biogas is made by fermenting animal and vegetable waste.  (a)  the table shows the percentage composition of the gases present in a sample of biogas. substance presentpercentage present in biogas carbon dioxide 36.8 hydrogen 0.6 methane 54.5 nitrogen 6.5 water vapour other substances 0.1 total 100.0  (i)  deduce the percentage of water vapour present in this sample of biogas.   ...   [1]  (ii)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  water. show outer shell electrons only. o hh  [2]  (iii)  describe a chemical test for water.  test  ..  observation  .   [2]",
            "5": "5 0620/33/o/n/19 \u00a9 ucles 2019 [turn over  (b) (i)  balance the chemical equation for the oxidation of methane to form hydrogen.  .ch4  +  o2    2co  +  .h2 [2]  (ii)  which one of these compounds belongs to the same homologous series as methane?   draw a circle around the correct answer.  butane          butene          methanoic acid          methanol  [1]  (c)\t\tmethane\t is\tpresent\t in\tthe\trefinery\t gas\tfraction\t produced\t by\tthe\tfractional\t distillation\t of\t petroleum.  (i)  match the fractions on the left with their uses on the right. \t \tthe\tfirst\tone\thas\tbeen\tdone\tfor\tyou. fraction use refinery\tgas making polishes gasoline fraction making roads lubricating fraction fuel for heating and cooking bitumen fuel for cars  [2]  (ii)  describe the fractional distillation of petroleum.   in your answer:  \u25cf state the physical property on which the separation of the fractions depends  \u25cf describe how the distillation is done to separate the fractions.   .   .   .   .   .   ...   [3]",
            "6": "6 0620/33/o/n/19 \u00a9 ucles 2019  (d)  the biogas fermentation mixture contains a small amount of compound m.   the structure of compound m is shown. nc ch cc h ch h sh h h hhh oo h  (i)  on the structure shown, draw a circle around the carboxylic acid functional group. [1]  (ii)  how many different types of atoms are present in compound m?   ...   [1]  [total: 15]",
            "7": "7 0620/33/o/n/19 \u00a9 ucles 2019 [turn over 3  a student investigated the reaction of magnesium carbonate with an excess of dilute   hydrochloric acid. mgco3  +  2hcl    mgcl 2  +  co2  +  h2o   the rate of reaction can be found by measuring the decrease in the mass of the reaction mixture  over time.   the results are shown on the graph. 180.0 179.8 179.6 179.4179.2179.0 02 04 06 0 time  / smass of reactionmixture  / g 80 100 120 140a b c d    (a)  determine the mass of the reaction mixture after 58  seconds.   ..   [1]  (b)  at which point on the graph, a, b, c or d, was the rate of reaction the fastest?   use the graph to explain your answer.      ..   [2]",
            "8": "8 0620/33/o/n/19 \u00a9 ucles 2019  (c)  when 0.42 g of magnesium carbonate is used, 120 cm3 of carbon dioxide is formed.   determine the volume of carbon dioxide produced when 1.26 g of magnesium carbonate reacts  completely.  volume of carbon dioxide = .. cm3  [1]  (d)  what effect do the following have on the rate of this reaction?  \u25cf decreasing the concentration of the acid.   all other conditions are kept the same.     \u25cf using smaller pieces of magnesium carbonate.   all other conditions are kept the same.     [2]  [total: 6]",
            "9": "9 0620/33/o/n/19 \u00a9 ucles 2019 [turn over 4  this question is about sulfur and compounds of sulfur.   an isotope of sulfur is written as shown. 33s16  (a)  deduce the number of protons, electrons and neutrons in this isotope of sulfur.  number of protons  .  number of electrons  ...  number of neutrons  ...  [3]  (b)  draw the electronic structure of a sulfur atom.  [2]  (c)  the table shows some observations made when four metals are heated with liquid sulfur. metal observations copper turns black very slowly gold no reaction sodium reacts explosively tin turns black slowly   use this information to put the four metals in order of their reactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]",
            "10": "10 0620/33/o/n/19 \u00a9 ucles 2019  (d)  name one source of sulfur.   ..   [1]  (e)  sulfur is used in the manufacture of sulfur dioxide and sulfuric acid.  (i)  give one different use of sulfur dioxide.   ...   [1]  (ii)  complete the word equation for the reaction of dilute sulfuric acid with magnesium. sulfuric acid + magnesium.. ..+..  [2]  [total: 11]",
            "11": "11 0620/33/o/n/19 \u00a9 ucles 2019 [turn over 5  this question is about group i elements.  (a)  the properties of some group i elements are shown in the table. elementmelting point in \u00b0cboiling point in \u00b0crelative thermal  conductivityatomic radius / pm lithium1342 84 152 sodium 97 883 142 186 potassium 63 760 102 rubidium 39 686 58 248  (i)  complete the table to estimate:  \u25cf the melting point of lithium  \u25cf the atomic radius of potassium.  [2]  (ii)  describe the trend in the boiling points of the group i elements down the group.   ...   [1]  (iii)  caesium is below rubidium in group i. \t \tuse\tthe\tinformation\t in\tthe\ttable\tto\tsuggest\twhy\tit\tis\tdifficult\tto\tpredict\tthe\tthermal\tconductivity\t of caesium.   .   ...   [1]  (iv)  predict the physical state of rubidium at 45 \u00b0c.   give a reason for your answer.   .   ...   [2]",
            "12": "12 0620/33/o/n/19 \u00a9 ucles 2019  (b)  lithium reacts with oxygen to form lithium oxide.  (i)  balance the chemical equation for this reaction.  .li  +  o2    .li2o [2]  (ii)  is lithium oxide an acidic oxide or a basic oxide?   give a reason for your answer.   .   .   ...   [1]  (iii)  state the name of the particle which is lost from a lithium atom when it forms a lithium ion.   ...   [1]  (iv)  a compound of lithium has the formula c2h5li.   complete the table to calculate the relative molecular mass of c2h5li.   use your periodic table to help you. type of atomnumber of atomsrelative atomic mass carbon hydrogen 5 1 5 \u00d7 1 = 5 lithium  relative molecular mass = ..  [2]  [total: 12]",
            "13": "13 0620/33/o/n/19 \u00a9 ucles 2019 [turn over 6  sodium hydroxide and ammonia are both bases. they both turn red litmus blue.  (a)  the chemical equation shows a reaction that produces sodium hydroxide. na2co3  +  ca(oh)2    2naoh  +  caco3   complete the word equation for this reaction. .. ..+ sodium hydroxide+.. ..  [2] (b)  aqueous sodium hydroxide can be used to test for chromium( iii) ions and iron( ii) ions.    complete the table to show the expected observations. ionobservation on adding a small  volume of aqueous sodium hydroxideobservation on adding an excess  of aqueous sodium hydroxide chromium( iii) (cr3+) iron( ii) (fe2+)  [3]  (c)  a student set up a long glass tube as shown. cotton wool soaked in aqueous ammoniadamp red litmus paper \t \tat\tfirst,\tthe\tlitmus\tpaper\tremained\tred.   after a short time the litmus paper was completely blue.   explain these observations using the kinetic particle model.                  ..   [3]",
            "14": "14 0620/33/o/n/19 \u00a9 ucles 2019  (d)  oxides of nitrogen are formed when ammonia is heated with oxygen in the presence of a  catalyst.  (i)  suggest why a catalyst is used.   ...   [1]  (ii)  state one other process which puts oxides of nitrogen into the atmosphere.   ...   [1]  (iii)  state one adverse effect of oxides of nitrogen on health.   ...   [1]  (e)  ammonium nitrate is present in many fertilisers.   which one of these compounds is also present in many fertilisers?   tick one box.  barium hydroxide  potassium phosphate  sodium chloride  tin( ii) sulfate  [1]  (f)  when ammonium chloride dissolves in water, the temperature of the solution decreases.   what is the name for a reaction where the temperature of the solution decreases?   ..   [1]  [total: 13]",
            "15": "15 0620/33/o/n/19 \u00a9 ucles 2019 [turn over 7  aluminium is manufactured by the electrolysis of molten aluminium oxide.  (a)  predict the products of the electrolysis of molten aluminium oxide at:  the positive electrode  .  the negative electrode.  ..  [2]  (b)  complete these sentences about the uses of aluminium using words from the list.  conductivity corrosion density heavy  malleability reduction strong weak   aluminium is used in the manufacture of aircraft because it is relatively .. and     has a low .. . aluminium is used for food containers because of its   resistance to .. .  [3]  (c)  the following statements are about the procedure for making crystals of hydrated  aluminium sulfate from aluminium hydroxide and sulfuric acid.  a  filter off the excess aluminium hydroxide.  b\t\tfilter\toff\tthe\tcrystals\tand\tdry\tbetween\tfilter\tpapers.  c\t\twarm\tthe\tfiltrate\tto\tthe\tpoint\tof\tcrystallisation.  d  add aluminium hydroxide to warm dilute sulfuric acid and stir.  e  leave the mixture at room temperature to form more crystals.  f  add more aluminium hydroxide to the sulfuric acid until the aluminium hydroxide is in  excess.   put the statements a, b, c, d, e and f in the correct order. \t \tthe\tfirst\tone\thas\tbeen\tdone\tfor\tyou. d  [2]  [total: 7]",
            "16": "16 0620/33/o/n/19 \u00a9 ucles 2019 8  this question is about dyes.  (a)  chromatography can be used to separate a mixture of dyes.   s, t, u and w are four different mixtures of dyes.   s, t, u and w were placed on a piece of chromatography paper.   two pure dyes, x and y, were also placed on the same piece of chromatography paper.   the results of the chromatography are shown. stu wx y  (i)  which mixture, s, t, u or w, contains dye x but not dye y?   ...   [1]  (ii)  which mixture, s, t, u or w, contains the smallest number of dyes?   ...   [1]  (iii)  which mixture, s, t, u or w, contains neither dye x nor dye y?   ...   [1]  (b)  indigo is a blue dye.   when an alkaline solution of indigo undergoes reduction, it turns colourless.  (i)  what is meant by the term reduction ?   ...   [1]  (ii)  a piece of white cloth is soaked in the colourless solution.   when the cloth is left in the air it turns blue.   what type of chemical reaction occurs?   draw a circle around the correct answer.  decomposition          fermentation          oxidation          polymerisation  [1]  [total: 5]",
            "17": "17 0620/33/o/n/19 \u00a9 ucles 2019blank page",
            "18": "18 0620/33/o/n/19 \u00a9 ucles 2019blank page",
            "19": "19 0620/33/o/n/19 \u00a9 ucles 2019blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/33/o/n/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w19_qp_41.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/41 paper 4  theory (extended) october/november 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 16 printed pages. [turn overib19 11_0620_41/3rp\u00a9 ucles 2019 *2338402729* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/41/o/n/19 \u00a9 ucles 2019 1  this question is about ions and ionic compounds.  (a)  choose from the following list of ions to answer the questions.  br \u2013 ca2+ cl \u2013 cr3+ cu2+  k+ li+ na+ so32\u2013 so42\u2013   each ion may be used once, more than once or not at all.   state which ion:  (i)\t\tgives\ta\tlilac \tcolour\tin\ta\tflame\ttest\t .   [1]  (ii)  forms a grey-green precipitate with aqueous ammonia     [1]  (iii)  forms a white precipitate with aqueous sodium hydroxide  ...   [1]  (iv)\t\tforms\ta\tcream\tprecipitate\twith\tacidified\t aqueous\tsilver\tnitrate\t     [1]  (v)\t\tforms\ta\twhite\tprecipitate\twith\tacidified\taqueous\tbarium\tnitrate.\t  ..   [1]  (b)\t\tdescribe\thow\tto\tdo\ta\tflame\ttest\ton\ta\tsample\tof\ta\tsalt.            ..   [2]  (c)  magnesium phosphate contains magnesium ions, mg2+, and phosphate ions, po43\u2013.   deduce the formula of magnesium phosphate.   ..   [1]  [total: 8]",
            "3": "3 0620/41/o/n/19 \u00a9 ucles 2019 [turn over 2 (a)  sulfur exists as a number of different isotopes.   what is meant by the term isotopes ?         ..   [2]  (b)\t\ta\tsulfide\tion\thas\tthe\tsymbol\tshown. 34s2\u2013 16  (i)\t\thow\tmany\tneutrons\tare\tcontained\tin\tthis\tsulfide\tion?   ...   [1]  (ii)\t\thow\tis\ta\tsulfide\tion,\ts2\u2013, formed from a sulfur atom?   ...   [1]  (iii)  which element forms an ion with a 2+ charge that has the same number of electrons as   a s2\u2013 ion?   ...   [1]",
            "4": "4 0620/41/o/n/19 \u00a9 ucles 2019  (c)  the manufacture of sulfuric acid by the contact process occurs in four stages.  stage 1  molten sulfur is burned in air to produce sulfur dioxide gas.  stage 2  sulfur dioxide is reacted with oxygen to form sulfur trioxide.  stage 3  sulfur trioxide is combined with concentrated sulfuric acid to form oleum, h2s2o7.  stage 4  oleum is added to water to form sulfuric acid.  (i)  complete the chemical equation for stage 1 by adding the appropriate state symbols.  s(.)  +  o2(.)    so2(.) [1]  (ii)  name the catalyst used in stage 2 and state the temperature used.  catalyst    temperature  .  \u00b0c  [2]  (iii)  write chemical equations for the reactions in stage 3 and stage 4.  stage 3  ...  stage 4  ...  [2]  (d)  sulfur dioxide is a toxic gas.  (i)  state one environmental reason why sulfur dioxide should not be released into the  atmosphere.   ...   [1]  (ii)  describe the test for sulfur dioxide.  test  ..   .  observations  ...   .  [2]",
            "5": "5 0620/41/o/n/19 \u00a9 ucles 2019 [turn over  (e)\t\tsulfur\tdioxide\treacts\twith\taqueous\t sodium\tsulfite\tto\tproduce\t a\tcompound\t with\tthe\tfollowing\t composition by mass: 29.1% na, 40.5% s and 30.4% o.   calculate the empirical formula of this compound.  empirical formula = ..  [3]  [total: 16]",
            "6": "6 0620/41/o/n/19 \u00a9 ucles 2019 3  this question is about metals and metal oxides.  (a)  most metals have a high melting point.   state one other physical property that all metals have.   ..   [1]  (b)  iron often rusts.   name the two substances, other than iron, that must be present for iron to rust.  1  .  2  .  [1]  (c)  iron can be obtained by heating iron( iii) oxide with zinc powder. fe2o3  +  3zn    2fe  +  3zno  (i)  what can be deduced about the reactivity of zinc from this reaction?   ...   [1]  (ii)  the ionic equation for this reaction is shown. 2fe3+  +  3zn    2fe  +  3zn2+   identify the oxidising agent in this reaction. explain your answer in terms of electron  transfer.  oxidising agent    explanation  .   .  [2]",
            "7": "7 0620/41/o/n/19 \u00a9 ucles 2019 [turn over  (d)  zinc oxide is amphoteric.   describe two simple experiments to show that zinc oxide is amphoteric.    name the reagents you would use and describe the observations you would make.  reagent 1  ...  observation    reagent 2  ...  observation    [3]  [total: 8]",
            "8": "8 0620/41/o/n/19 \u00a9 ucles 2019 4  insoluble salts can be made by precipitation reactions.   a student mixed solutions of some soluble salts.   the results the student obtained are shown in the table. second salt solution co(no3)2(aq) agno3(aq) pb(no3)2(aq) first\tsalt solutionnai(aq) no change yellow precipitate yellow precipitate na2co3(aq) purple precipitate yellow precipitate white precipitate na2so4(aq) no change white precipitate white precipitate   all sodium salts are soluble in water.   use only results from the table to answer the following questions.   (a) name:  (i) an insoluble cobalt salt  .   [1]  (ii) an insoluble yellow lead salt.     [1]  (b)  write the chemical equation for the reaction in which silver carbonate is formed.   ..   [2]  (c)  write the ionic equation for the reaction in which lead( ii) iodide is formed.   ..   [2]  (d)  aqueous silver nitrate produces a yellow precipitate with both iodide ions and carbonate ions.  when\ttesting\tan\tunknown\tsolution\tfor\tiodide\tions,\tthe\taqueous\tsilver\tnitrate\tis\tacidified. \t \texplain\twhy\tthe\taqueous\tsilver\tnitrate\tis\tacidified.      ..   [1]  [total: 7]",
            "9": "9 0620/41/o/n/19 \u00a9 ucles 2019 [turn over 5 (a)  part of the structure of synthetic polymer a is shown. cch3ch3 ch3ch3cch3 ch3cch3 ch3cch3 ch3cch3 ch3c  (i)  what type of synthetic polymer is a?   ...   [1]  (ii)  deduce the empirical formula of polymer a.   ...   [1]  (iii)  draw the structure of the monomer from which polymer a is made.  [2]  (b)  the formula c4h10 represents two different structural isomers.  (i)  what is meant by the term structural isomers?   .   .   ...   [2]  (ii)  draw the structures of two structural isomers with the formula c4h10.   show all of the atoms and all of the bonds.  [2]  (iii)  all structural isomers of c4h10\tare\tflammable.   write a chemical equation for the incomplete combustion of c4h10.   ...   [2]  [total: 10]",
            "10": "10 0620/41/o/n/19 \u00a9 ucles 2019 6  dilute hydrochloric acid, hc l (aq), reacts with aqueous sodium carbonate, na2co3(aq).   the chemical equation for the reaction is shown. 2hcl  +  na2co3    2nacl  +  co2  +  h2o  (a)  a 25.0 cm3 portion of na2co3(aq)\twas\tplaced\tin\ta\tconical\tflask\twith\ta\tfew\tdrops\tof\ta\tsuitable\t indicator. it was titrated against hcl (aq) of concentration 0.180 mol /  dm3.   20.0 cm3 of hcl (aq) was required to reach the end-point.   calculate the concentration of the na2co3(aq), in mol / dm3, using the following steps.  \u25cf calculate the number of moles of hc l used in the titration.  .. mol  \u25cf calculate the number of moles of na2co3 contained in the 25.0 cm3 portion of na2co3(aq).  .. mol  \u25cf calculate the concentration of the na2co3(aq) in mol / dm3.  .. mol / dm3  [3]  (b)  in another experiment, the volume of carbon  dioxide, co2, produced was 48.0 cm3, measured  at room temperature and pressure.   how many moles of co2 is this?  moles of co2 = .. mol  [1]",
            "11": "11 0620/41/o/n/19 \u00a9 ucles 2019 [turn over  (c)  a sample of concentrated hydrobromic acid, hbr(aq), was electrolysed using platinum  electrodes.   the concentration of the hydrobromic acid was 8.89 mol / dm3.  (i)  calculate the concentration of the hbr(aq) in g / dm3.  concentration of hbr(aq) = .. g / dm3  [1]  (ii)  explain why concentrated hbr(aq) can conduct electricity.   .   .   ...   [2]  (iii)  magnesium is not a suitable material from which to make the electrodes.   explain why.   .   ...   [1]  (iv)  predict the product formed at the anode when concentrated hbr(aq) is electrolysed.   ...   [1]  (v)  write the ionic half-equation for the reaction occurring at the cathode.   ...   [2]  [total: 11]",
            "12": "12 0620/41/o/n/19 \u00a9 ucles 2019 7  this question is about ethanol.  (a)  ethanol that is suitable for use as a fuel can be manufactured from sugars such as glucose,  c6h12o6, by a two-step process.   describe how this can be done. in your answer, include:  \u25cf an equation for the reaction in which ethanol is formed  \u25cf the essential conditions for the reaction in which ethanol is formed  \u25cf the name of the process used to obtain ethanol that is pure enough to use as a fuel from  the reaction mixture.                              ..   [5]",
            "13": "13 0620/41/o/n/19 \u00a9 ucles 2019 [turn over  (b) the equation for the complete combustion of ethanol is shown. hch hch hoho o +3 hoh +3 oc 2 o   use the bond energies in the table to calculate the energy change, in kj / mol, for the complete  combustion of ethanol. bondbond energy in kj / mol c\u2013c 347 c\u2013h 413 c\u2013o 358 c=o 805 o\u2013h 464 o=o 498  \u25cf energy needed to break bonds.  .. kj  \u25cf energy released when bonds are formed.  .. kj  \u25cf energy change for the complete combustion of ethanol.  energy change = .. kj / mol  [3]",
            "14": "14 0620/41/o/n/19 \u00a9 ucles 2019  (c)  ethanol can be oxidised by hydrogen peroxide to form ethanal, ch3cho. a catalyst for this  reaction is fe3+.  (i)  what is meant by the term catalyst ?   .   .   ...   [2]  (ii)  the structure of ethanal is shown. hch hc ho   complete the dot-and-cross diagram to show the electron arrangement in a molecule of  ethanal. show outer shell electrons only. hhh hc c o  [3]  (iii)  the table gives the boiling points of ethanal and ethanol. substance boiling point / \u00b0c ethanal 20 ethanol 78   in terms of attractive forces between particles, suggest why ethanal has a lower boiling  point than ethanol.   .   ...   [1]",
            "15": "15 0620/41/o/n/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (d)  ethene gas reacts with steam to form gaseous ethanol. c2h4(g)  +  h2o(g)    ch3ch2oh(g)   the reaction can reach a position of equilibrium. the forward reaction is exothermic.  (i)  state and explain the effect of increasing the pressure on the position of equilibrium .   all other conditions are unchanged.   .   .   ...   [2]  (ii)  increasing the pressure of a gas increases its concentration.   state and explain the effect of increasing the pressure on the rate of the reaction.   all other conditions are unchanged.   .   .   ...   [2]  (iii)  state and explain the effect of increasing the temperature on the position of equilibrium .   all other conditions are unchanged.   .   .   ...   [2]  [total: 20]",
            "16": "16 0620/41/o/n/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w19_qp_42.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 12.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/42 paper 4  theory (extended) october/november 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 12 printed pages. [turn overib19 11_0620_42/2rp\u00a9 ucles 2019 *6351983657* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/42/o/n/19 \u00a9 ucles 2019 1  the periodic table is very useful to chemists.   refer only to elements with atomic numbers 1 to 36 in the periodic table provided when answering  question 1 .  (a)  use information from the periodic table provided to identify one element which:  (i)  has atoms with exactly 9 protons  .   [1]  (ii)  has atoms with 0 neutrons     [1]  (iii)  has atoms with exactly 23 electrons  .   [1]  (iv)  has atoms with an electronic structure of 2,8,6     [1]  (v)  forms ions with a charge of 3\u2013 containing 18 electrons     [1]  (vi)  forms ions with a charge of 2+ containing 10 electrons    [1]  (vii)  has a relative atomic mass that shows it has at least two isotopes.  .   [1]  (b)\t\tstate\twhich\tmetal\tin\tthe\tfirst\t36\telements:  (i)  is the group i element which reacts most vigorously with water  ..   [1]  (ii)  reacts with air to form lime.  ...   [1]  (c)\t\tone\telement\tin\tthe\tfirst\t36\telements\tis\tused\tas\tthe\t fuel\tin\ta\tfuel\tcell.  (i)  name this element.   ...   [1]  (ii)  write the overall chemical equation for the reaction which occurs when the element in   (c)(i) reacts in a fuel cell.   ...   [2]  [total: 12]",
            "3": "3 0620/42/o/n/19 \u00a9 ucles 2019 [turn over 2  the gases ar, co2, n2 and o2 are in clean, dry air.   co, no, no2 and so2 are gases commonly found in polluted air.  (a)  what percentage of clean, dry air is n2?   give your answer to the nearest whole number.  .. %  [1]  (b)  name the process used to separate o2 from clean, dry air.   ..   [2]  (c)  state one major adverse effect of the pollutant so2.   ..   [1]  (d)  no and no2 are produced in car engines.   describe how oxides of nitrogen form in a car engine.         ..   [2]  (e)  many cars have catalytic converters in their exhaust systems. in a catalytic converter, most of  the co and no formed in a car engine is changed into less harmful products.   identify these products and state the metal catalyst used.  products  .  catalyst  ..  [3]  (f)  co is formed from the incomplete combustion of fossil fuels such as methane.   write a chemical equation to show the incomplete combustion of methane.   ..   [2]",
            "4": "4 0620/42/o/n/19 \u00a9 ucles 2019  (g)  the co2 in air is part of the carbon cycle.   the scheme shows a simple representation of part of the carbon cycle. carbon dioxide in the air animalsglucose found in green plant sfeedingab  (i)\t\tstate\tthe\tscientific\tterms\tfor\teach\tof\tprocess\ta and process b.  a  .  b  .  [2]  (ii)  plants convert glucose into complex carbohydrates.   a unit of glucose can be represented as ho oh.   complete the diagram to show the complex carbohydrate formed from three units of  glucose. show all of the atoms and all of the bonds in the linkages.  [2]  (iii)  complex carbohydrates break down to form simple sugars.   state two ways that complex carbohydrates can be broken down into simple sugars.  1  ..  2  ..  [2] (iv)  name a suitable technique for separating and identifying the individual sugars formed  when complex carbohydrates are broken down.   ...   [1]  [total: 18]",
            "5": "5 0620/42/o/n/19 \u00a9 ucles 2019 [turn over 3  ammonia is an important chemical.  (a)  ammonia is manufactured by the haber process. the reaction is reversible.  (i)  what is the sign for a reversible reaction?   ...   [1]  (ii)  state the essential conditions for the manufacture of ammonia by the haber process  starting from hydrogen and nitrogen. include a chemical equation to show the reaction  which occurs.   .   .   .   .   .   ...   [5]  (iii)  name one raw material which is a source of the hydrogen used in the haber process.   ...   [1]  (b)  ammonia is a base and reacts with sulfuric acid to form the salt, ammonium sulfate.  (i)  what is meant by the term base?   ...   [1]  (ii)  name the industrial process used to manufacture sulfuric acid.   ...   [1]  (iii)  write a chemical equation for the reaction between ammonia and sulfuric acid.   ...   [2]",
            "6": "6 0620/42/o/n/19 \u00a9 ucles 2019  (c)  when aqueous ammonia is added to aqueous iron( ii) sulfate a green precipitate is seen. this  green precipitate turns red-brown at the surface.  (i)  name the green precipitate.   ...   [1]  (ii)  suggest why the green precipitate turns red-brown at the surface.   .   ...   [2]  (iii)  state what happens when an excess of aqueous ammonia is added to the green precipitate.   ...   [1]",
            "7": "7 0620/42/o/n/19 \u00a9 ucles 2019 [turn over  (d)  ammonia reacts with oxygen as shown. 4nh3(g)  +  5o2(g)    4no(g)  +  6h2o(g)  (i)  calculate the volume of oxygen at room temperature and pressure, in dm3, that reacts with  4.80 dm3 of ammonia.  volume = .. dm3  [3]  (ii)  the chemical equation for the reaction can be represented as shown. h4 n hh+o o 5 hoh +6 n4 o   use the bond energies in the table to calculate the energy change, in kj / mol, which  occurs when one mole of nh3 reacts. bond n\u2013h o=o n=o o\u2013h bond energy in kj / mol 391 498 587 464  \u25cf energy needed to break bonds.  .. kj  \u25cf energy released when bonds are formed.  .. kj  \u25cf energy change when one mole of nh3 reacts.  energy change = .. kj / mol  [4]  [total: 22]",
            "8": "8 0620/42/o/n/19 \u00a9 ucles 2019 4  many substances conduct electricity.  (a)  identify all the particles responsible for the passage of electricity in: \t \u25cf\t graphite\t ... \t \u25cf\t magnesium\tribbon\t  .. \t \u25cf\t molten\tcopper( ii) bromide.  .  [4]  (b)  a student used the following apparatus to electrolyse concentrated aqueous sodium chloride  using inert electrodes. + \u2013inert electrodesconcentrated aqueou s sodium chloride  (i)  suggest the name of a metal which could be used as the inert electrodes.   ...   [1]  (ii)   name the gas formed at the positive electrode.   ...   [1]  (iii)  write an ionic half-equation for the reaction occurring at the negative electrode. include  state symbols.   ...   [3]  (iv)  how, if at all, does the ph of the solution change during the electrolysis? explain your answer.   .   .   ...   [3]",
            "9": "9 0620/42/o/n/19 \u00a9 ucles 2019 [turn over  (c)  a student used the following electrochemical cell.   the reading on the voltmeter was +1.10 v. copper electrode dilute sulfuric acidzinc electrodevvoltmeter  (i)\t\tdraw\tan\tarrow\ton\tthe\tdiagram\tto\tshow\tthe\tdirection\tof\telectron\tflow.\t [1]  (ii)  suggest the change, if any, in the voltmeter reading if the zinc electrode was replaced with  an iron electrode. explain your answer.   .   ...   [2]  (iii)  the zinc electrode was replaced with a silver electrode. the reading on the voltmeter was  \u20130.46 v.   suggest why the sign of the voltmeter reading became negative.   .   ...   [1]  [total: 16]",
            "10": "10 0620/42/o/n/19 \u00a9 ucles 2019 5  methanol, ch3oh, is a member of the homologous series of alcohols.  (a)  methanol can be made from methane in a two-step process.  step 1  methane is reacted with chlorine gas to produce chloromethane, ch3cl.  step 2  ch3cl is reacted with sodium hydroxide to produce ch3oh and one other product.  (i)  what conditions are needed in step 1?   ...   [1]  (ii)  write the chemical equation for the reaction which occurs in step 1.   ...   [1]  (iii)  state the type of organic reaction occurring in step 1.   ...   [1]  (iv)  complete the chemical equation for step 2.  ch3cl  +  naoh    ch3oh  +  .. [1]  (b)  draw a dot-and-cross diagram to show the electron arrangement in a molecule of methanol.  show outer shell electrons only. c hh o hh  [2]",
            "11": "11 0620/42/o/n/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (c)  methanol reacts with propanoic acid to form an ester with a molecular formula c4h8o2.  (i)  name the ester formed when methanol reacts with propanoic acid.   ...   [1]  (ii)  name one other substance formed when methanol reacts with propanoic acid.   ...   [1]  (iii)  draw the structure of an ester which is a structural isomer of the ester named in (c)(i).  show all of the atoms and all of the bonds.  [3]  (iv)  state the conditions needed to form an ester from a carboxylic acid and an alcohol.   ...   [1]  [total: 12]",
            "12": "12 0620/42/o/n/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w19_qp_43.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.a copy of the periodic table is printed on page 16.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/43 paper 4  theory (extended) october/november 2019  1 hour 15 minutes candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this document consists of 14 printed pages and 2 blank pages. [turn overib19 11_0620_43/2rp\u00a9 ucles 2019 *4049433183* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/43/o/n/19 \u00a9 ucles 2019 1 (a)  atoms are made of smaller particles called electrons, neutrons and protons.   complete the table. particle relative charge relative mass electron1 1840 neutron proton +1  [2]  (b)  the table gives information about atoms and ions a, b and c.   complete the table. number of electronsnumber of neutronsnumber of protonssymbol a 14 1327al13 b 1225mg2+ 12 c 10 10 9  [6]  [total: 8]",
            "3": "3 0620/43/o/n/19 \u00a9 ucles 2019 [turn over 2  the table shows the melting points, boiling points and electrical conductivities of six substances   d, e, f, g, h and i. substancemelting point / \u00b0cboiling point / \u00b0celectrical conductivity  when solidelectrical conductivity  when liquid d 1610 2230 non-conductor non-conductor e 801 1413 non-conductor good conductor f \u2013119 43 non-conductor non-conductor g 1535 2750 good conductor good conductor h 114 184 non-conductor non-conductor i \u2013210 \u2013196 non-conductor non-conductor   choose substances from the table which match the following descriptions. each substance may be  used once, more than once or not at all.  (a)  which substance is a liquid at 25 \u00b0c?  ..   [1]  (b)  which substance is a gas at 25 \u00b0c?     [1]  (c)  which three substances contain simple molecules?   ..   [3]  (d)  which substance could be a metal? give a reason for your answer.  substance  ..  reason       [2]  (e)  which substance has a macromolecular structure? give two reasons for your answer.  substance  ..  reason 1  .  reason 2  .  [3] (f)  which substance is an ionic solid? give one reason for your answer.  substance  ..  reason       [2]  [total: 12]",
            "4": "4 0620/43/o/n/19 \u00a9 ucles 2019 3 (a)  name the ore of aluminium which mainly consists of aluminium oxide.   ..   [1]  (b)  aluminium is produced by the electrolysis of aluminium oxide dissolved in molten cryolite. negative electrodepositive electrode molten mixture of aluminium oxide and cryolite aluminiumwaste gases  (i)  give two reasons why the electrolysis is done using a molten mixture of aluminium oxide  and cryolite instead of molten aluminium oxide only.  1  ..  2  ..  [2]  (ii)  write ionic half-equations for the reactions occurring at the electrodes.  positive electrode    negative electrode  ..  [2] (iii)  the anodes are made of carbon and have to be replaced regularly.   explain why the carbon anodes have to be replaced regularly.   .   ...   [2]",
            "5": "5 0620/43/o/n/19 \u00a9 ucles 2019 [turn over  (c)  the positions of some common metals in the reactivity series are shown. most reactive magnesium aluminium least reactive copper  (i)  when magnesium is placed in aqueous copper( ii) sulfate a displacement reaction occurs  immediately.   write an ionic equation for the reaction. include state symbols.   ...   [2]  (ii)  state two observations you would make when magnesium is placed in aqueous  copper( ii) sulfate.  1  ..  2  ..  [2]  (iii)  when aluminium foil is added to aqueous copper( ii) sulfate no immediate reaction takes  place.    explain why.   ...   [1]  (d)  aluminium powder reacts with iron( iii) oxide to produce aluminium oxide and iron.   write a chemical equation for this reaction.   ..   [2]  [total: 14]",
            "6": "6 0620/43/o/n/19 \u00a9 ucles 2019 4  this question is about phosphorus and compounds of phosphorus.  (a)  a phosphorus molecule contains four phosphorus atoms only.   what is the formula of a phosphorus molecule?   ..   [1]  (b)  phosphorus reacts with chlorine gas to produce phosphorus( iii) chloride, pc l 3.  (i)  write a chemical equation for the reaction between phosphorus and chlorine to produce  phosphorus( iii) chloride, pc l 3.   ...   [2]  (ii)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  phosphorus( iii) chloride, pc l 3. show outer shell electrons only. pcl cl cl  [2]",
            "7": "7 0620/43/o/n/19 \u00a9 ucles 2019 [turn over  (c)  gaseous phosphorus( iii) chloride, pcl 3, reacts with gaseous chlorine to form gaseous  phosphorus( v) chloride, pc l 5. pcl 3(g)  +  cl 2(g)    pcl 5(g)   the chemical equation for this reaction can be represented as shown. cl clcl p+ clcl cl cl clp cl cl  (i)  use the bond energies in the table to calculate the energy change, in kj / mol, of the  reaction. bond bond energy in kj / mol p\u2013 cl 326 cl \u2013 cl 243  \u25cf energy needed to break bonds.  .. kj  \u25cf energy released when bonds are formed.  .. kj  \u25cf energy change of reaction.  energy change = .. kj / mol  [3]  (ii)  deduce whether the energy change for this reaction is exothermic or endothermic. explain  your answer.   .   ...   [1]",
            "8": "8 0620/43/o/n/19 \u00a9 ucles 2019  (d)  under certain conditions the reaction reaches equilibrium. pcl 3(g)  +  cl 2(g)    pcl 5(g)   state and explain the effect, if any, on the position of equilibrium  if the pressure is increased.   all other conditions are unchanged.         ..   [2]  (e)  phosphine, ph3, is produced by the reaction between water and calcium phosphide, ca3p2.   balance the chemical equation for this reaction.  ca3p2  +  ..h2o    ...ca(oh)2  +  ..ph3 [2]  (f)  the phosphonium ion, ph4+, is similar to the ammonium ion.  (i)  state the formula of the ammonium ion.  ...   [1]  (ii)  suggest the formula of phosphonium iodide.  ...   [1]  (g)  calcium phosphate contains the phosphate ion, po43\u2013.   what is the formula of calcium phosphate?   ..   [1]  (h)  phosphorus forms another compound with hydrogen with the following composition by mass:  p, 93.94%; h, 6.06%.  (i)  calculate the empirical formula of the compound.  empirical formula = ..  [2]  (ii)  the compound has a relative molecular mass of 66.   deduce the molecular formula of the compound.  molecular formula = ..  [1]  [total: 19]",
            "9": "9 0620/43/o/n/19 \u00a9 ucles 2019 [turn over 5  nitrates such as ammonium nitrate are used as fertilisers. \t\tthe\tfinal\tstage\tin\tthe\tproduction\tof\tammonium\tnitrate\tis\tshown\tin\tthe\tequation. ca(no3)2  +  2nh3  +  co2  +  h2o    2nh4no3  +  caco3   calculate the maximum mass of ammonium nitrate that can be produced from 820 g of   calcium nitrate, ca(no3)2, using the following steps.   the relative formula mass, mr, of calcium nitrate, ca(no3)2, = 164.  \u25cf calculate the number of moles of ca(no3)2 in 820 g.  .. mol  \u25cf deduce the number of moles of nh4no3 produced.  .. mol  \u25cf calculate the mr of nh4no3.  mr of nh4no3 = ..  \u25cf calculate the maximum mass of ammonium nitrate produced.  . . g  [4]",
            "10": "10 0620/43/o/n/19 \u00a9 ucles 2019 6  this question is about sulfuric acid and substances that can be made from sulfuric acid.  (a)  sulfuric acid is a strong acid.   what is meant by the term strong acid ?  strong  .  acid    [2]  (b)  dilute sulfuric acid and aqueous sodium hydroxide are used to make aqueous sodium sulfate,  na2so4(aq), or aqueous sodium hydrogen sulfate, nahso4(aq). the method includes use of  the following apparatus. conical flas kdilute sulfuric acid 25.0  cm3 of aqueou s sodium hydroxid e   25.0 cm3 of aqueous sodium hydroxide of concentration 0.100 mol / dm3 was neutralised by  25.0 cm3 of dilute sulfuric acid of concentration 0.0500 mol / dm3. the equation for the reaction  is shown. this is reaction 1.  2naoh(aq)  +  h2so4(aq)    na2so4(aq)  +  2h2o(l) reaction 1   the same technique and the same solutions can be used to make aqueous sodium hydrogen sulfate. the equation for the reaction is shown. this is reaction 2.  naoh(aq)  +  h 2so4(aq)    nahso4(aq)  +  h2o(l) reaction 2   complete the table to calculate the volume of dilute sulfuric acid that reacts with 25.0 cm3 of  aqueous sodium hydroxide in reaction 2. volume of 0.0500 mol / dm3 dilute sulfuric acid in cm3volume of 0.100 mol / dm3 aqueous sodium hydroxide in cm3 reaction 1 25.0 25.0 reaction 2 25.0  [1]",
            "11": "11 0620/43/o/n/19 \u00a9 ucles 2019 [turn over  (c)  aqueous sodium  hydrogen sulfate, nahso4(aq), contains the ions na+(aq), h+(aq)   and so42\u2013(aq).   describe what you would see if the following experiments were done.  (i)\t\ta\tflame\ttest\twas\tdone\ton\taqueous\tsodium\thydrogen\tsulfate.   ...   [1]  (ii)  solid copper( ii) oxide was added to aqueous sodium hydrogen sulfate and the mixture  was warmed.   .   ...   [2]  (d)  a test can be done to show the presence of so42\u2013(aq)\tby\tadding\tacidified\t aqueous\t barium\tchloride\t or\tacidified\taqueous\tbarium\tnitrate.  (i)  state the observation that would show that so42\u2013 is present.   ...   [1]  (ii)  write an ionic equation for the reaction that occurs if so42\u2013 is present. include state  symbols.   ...   [2]  [total: 9]",
            "12": "12 0620/43/o/n/19 \u00a9 ucles 2019 7  addition polymerisation and condensation polymerisation are two types of polymerisation.  (a)  which functional group is present in all the monomers which are used to make addition  polymers?   ..   [1]  (b)  part of an addition polymer is shown. cch3 hcch3 hcch3 hcch3 hcch3 hcch3 h  (i)  how many monomer units are needed to make the part of the addition polymer shown?   ...   [1]  (ii)  draw the structure of the monomer that is used to make this addition polymer. show all of  the atoms and all of the bonds.   name the monomer.  name  ...  [2]  (iii)  state the empirical formula of:  the monomer  ..  the polymer.    [2]",
            "13": "13 0620/43/o/n/19 \u00a9 ucles 2019 [turn over  (c)  complex carbohydrates are natural condensation polymers. they can be broken down into  colourless\tmonomers\twhich\tcan\tthen\tbe\tseparated\tand\tidentified.   x is a complex carbohydrate.   starting with a sample of x, describe how to produce, separate, detect and identify the monomers which make it up.   your answer should include:  \u25cf the name of the process used to break down x into its monomers  \u25cf two types of substance that can be used to break down x  \u25cf the name of the process used to separate  the monomers  \u25cf the method used to detect the monomers after they have been separated  \u25cf the method used to identify the monomers after they have been separated and detected.                                    ..   [6]  (d)  synthetic polyamides are condensation polymers.  (i)  name a synthetic polyamide.   ...   [1]  (ii)  synthetic polyamides can be made by reacting carboxylic acids with amines.   name the other substance that is produced in this reaction.   ...   [1]  [total: 14]",
            "14": "14 0620/43/o/n/19 \u00a9 ucles 2019blank page",
            "15": "15 0620/43/o/n/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/43/o/n/19 \u00a9 ucles 2019 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr franciu m \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 4840 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 6447 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 4539 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169101 md mendelevium \u201370 yb ytterbium 173102 no nobelium \u201371 lu lutetium 175103 lr lawrenciu m \u2013"
        },
        "0620_w19_qp_51.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 7 and 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/51 paper 5  practical test october/november 2019  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge assessment international education cambridge international general certificate of secondary education this document consists of 8 printed pages. [turn overib19 11_0620_51/fp\u00a9 ucles 2019 *9022804374* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/51/o/n/19 \u00a9 ucles 2019 1  you are going to investigate the reaction between dilute hydrochloric acid and three different  concentrations of aqueous sodium hydroxide, labelled r, s and t.   read all the instructions carefully before starting the experiments.   instructions  you are going to do three experiments.   experiment 1  \u25cf fill the burette up to the 0.0 cm3 mark with dilute hydrochloric acid.  \u25cf use the measuring cylinder to pour 20 cm3 of solution r into the conical flask.  \u25cf add six drops of methyl orange indicator to the conical flask.  \u25cf add dilute hydrochloric acid from the burette to the conical flask, 1.0 cm3 at a time, while  swirling the conical flask, until the solution just changes colour.  \u25cf record the burette readings in the table.  \u25cf empty the conical flask and rinse it with distilled water.  experiment 2  \u25cf repeat experiment 1 using solution s instead of solution r.  \u25cf record the burette readings in the table.   experiment 3  \u25cf repeat experiment 1 using solution t instead of solution r.  \u25cf record the burette readings in the table.  (a)  complete the table. burette reading / cm3 experiment 1 using solution rexperiment 2 using solution sexperiment 3 using solution t final burette reading initial burette reading volume used  [4]  (b)  what colour change is observed in the conical flask at the end-point?  from  to     [2]  (c)  suggest why universal indicator is not a suitable indicator to use in these experiments.      ..   [1]",
            "3": "3 0620/51/o/n/19 \u00a9 ucles 2019 [turn over  (d) (i) complete the sentences.   experiment  needed the smallest volume of dilute hydrochloric acid to change the  colour of the methyl orange indicator.   experiment  needed the largest volume of dilute hydrochloric acid to change the  colour of the methyl orange indicator.  [1]  (ii)  determine the simplest whole number ratio of volumes of dilute hydrochloric acid used in  experiments 1 and 2.   experiment 1  :  experiment 2  [1]  (iii)  deduce the order of concentrations of the solutions of aqueous sodium hydroxide,   r, s and t.  most concentrated        least concentrated     [1]  (e)  what would be the effect on the results, if any, if the solutions of aqueous sodium hydroxide  were warmed before adding the dilute hydrochloric acid? give a reason for your answer.  effect on the results  ...  reason    [2]  (f)  suggest how the reliability of the results could be checked.      ..   [2]  (g)  suggest a different method, not involving an indicator, of finding the order of concentrations of  the solutions of aqueous sodium hydroxide, r, s and t.         ..   [3]  [total: 17]",
            "4": "4 0620/51/o/n/19 \u00a9 ucles 2019 2  you are provid ed with solid u and liquid v.   do the following tests on solid u and liquid v, recording all of your observations at each stage.   tests on solid u  (a)  do a flame test on a small sample of solid u.   record your observations.   ..   [1]   add the rest of solid u to about 10 cm3 of distilled  water in a boiling tube. stopper the boiling tube  and shake the mixture to dissolve solid u and form solution u.  (b)  describe the colour of solution u.   ..   [1]   divide solution u into three approximately equal portions in three test- tubes.  (c) (i)  add a few drops of aqueous sodium hydroxide to the first portion of solution u.   record your observations.   ...   [1]  (ii)  now add an excess of aqueous sodium hydroxide to this mixture.   record your observations.   ...   [1]  (d) (i)  add a few drops of aqueous ammonia to the second portion of solution u.   record your observations.   ...   [2]  (ii)  now add an excess of aqueous ammonia to this mixture.   record your observations.   ...   [1]  (e)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous barium nitrate to the third  portion of solution u. leave to stand for 5 minutes.   record your observations.   ..   [2]  (f)  solid u contains three different ions.   what conclusions can you draw about the ions present in solid u?      ..   [3]",
            "5": "5 0620/51/o/n/19 \u00a9 ucles 2019 [turn over   tests on liquid v  (g)  describe the appearance of liquid v.   record your observations.   ..   [1]  (h)  use a teat pipette to place a few drops of liquid v onto a watch-glass. put the stopper back into  the test-tube of liquid v. use a lighted splint to touch the surface of liquid v carefully.   record your observations.   ..   [1]   (i)  use a spatula to transfer a small crystal of iodine carefully into the rest of liquid v in the  stoppered test-tube. put the stopper back into the test-tube and shake the test-tube.   record your observations.      ..   [2]  (j)  draw one conclusion about liquid v.   ..   [1]  [total: 17]",
            "6": "6 0620/51/o/n/19 \u00a9 ucles 2019 3  potassium nitrate and ammonium chloride are two salts. the energy change when they each  dissolve in water is endothermic.   plan an experiment to show which of these two salts produces the larger endothermic energy  change per gram.   your answer should include:  \u25cf any measurements you would take and record  \u25cf how the results could be used to draw a conclusion.   you are provided with potassium nitrate and ammonium chloride, distilled water and common  laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "7": "7 0620/51/o/n/19 \u00a9 ucles 2019notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh 4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "8": "8 0620/51/o/n/19 \u00a9 ucles 2019tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment  international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w19_qp_52.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 11 and 12. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/52 paper 5  practical test october/november 2019  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge assessment international education cambridge international general certificate of secondary education this document consists of 9 printed pages and 3 blank pages. [turn overib19 11_0620_52/2rp\u00a9 ucles 2019 *0920456226* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/52/o/n/19 \u00a9 ucles 2019 1  you are going to investigate the temperature changes when two different solids, n and o, dissolve  in water.   read all the instructions carefully before starting the experiments.   instructions   you are going to do two experiments.  (a) experiment 1  \u25cf put a polystyrene cup in the 250 cm3 beaker for support.  \u25cf use the measuring cylinder to pour 30 cm3 of distilled water into the polystyrene cup.  \u25cf measure the initial temperature of the distilled water and record it in the table.  \u25cf add all of solid n to the distilled water, start the timer and stir the mixture with the stirring  thermometer.  \u25cf continue to stir the mixture and measure the temperature of the mixture every 30 seconds  for three minutes (180 seconds).  \u25cf record your results in the table. time / s 0 30 60 90 120 150 180 temperature of mixture / \u00b0c  [2]  (b) experiment 2  \u25cf place the other polystyrene cup in the 250 cm3 beaker for support.  \u25cf use the measuring cylinder to pour 30 cm3 of distilled water into the polystyrene cup.  \u25cf measure the initial temperature of the distilled water and record it in the table.  \u25cf add all of solid o to the distilled water, start the timer and stir the mixture with the stirring  thermometer.  \u25cf continue to stir the mixture and measure the temperature of the mixture every 30 seconds  for three minutes (180 seconds).  \u25cf record your results in the table. time / s 0 30 60 90 120 150 180 temperature of mixture / \u00b0c  [2]",
            "3": "3 0620/52/o/n/19 \u00a9 ucles 2019 [turn over  (c)  plot your results for experiments 1 and 2 on the grid. draw two smooth line graphs.   clearly label your graphs. 03 06 09 0 120 time  / s150 180 210 240temperature of mixture  / \u00b0c  [4]  (d) (i)  from your graph, deduce the time taken for the initial temperature of the solution in  experiment 2 to change by 3 \u00b0c.   show clearly on the grid  how you worked out your answer.  .. s  [3]  (ii)  extend your graph for experiment 1 to suggest the expected temperature of the mixture  after 240 seconds.  .. \u00b0c  [1]  (e)  is the energy change in experiment 2 exothermic or endothermic? explain your answer.      ..   [1]",
            "4": "4 0620/52/o/n/19 \u00a9 ucles 2019  (f)  state two possible sources of error in these experiments. suggest two improvements to  reduce each of these sources of error.  source of error 1    improvement 1  ...  source of error 2    improvement 2  ...  [4]  (g)  suggest and explain the effect on the results if experiment 1 were repeated using 15 cm3 of  distilled water.      ..   [2]  [total: 19]",
            "5": "5 0620/52/o/n/19 \u00a9 ucles 2019 [turn over 2  you are provided with two solids, p and q, which are both salts.   do the following tests on solid p and solid q, recording all of your observations at each stage.  tests on solid p  (a)\t\tdo\ta\tflame\ttest\ton\ta\tsmall\tsample\tof\tsolid\t p.   record your observations.   ..   [1]   add the rest of solid p to about 10 cm3 of distilled water in a boiling tube. stopper the boiling  tube and shake the mixture to dissolve solid p and form solution p. divide solution p into three  approximately equal portions in two test-tubes and one boiling tube.  (b) (i)\t \tadd\ta\tfew\tdrops\tof\taqueous\t sodium\thydroxide\t to\tthe\tfirst\tportion\tof\tsolution\t p in a test-tube.   record your observations.   ...   [1]  (ii)  now add an excess of aqueous sodium hydroxide to the mixture.   record your observations.   ...   [1]  (c) (i)  add a few drops of aqueous ammonia to the second portion of solution p in a test-tube.   record your observations.   ...   [1]  (ii)  now add an excess of aqueous ammonia to this mixture.   record your observations.   ...   [2]  (d)  add a small piece of aluminium foil and about 2 cm3 of aqueous sodium hydroxide to the third  portion of solution p in a boiling tube. gently warm the mixture. test the gas produced with  litmus paper.   record your observations.      ..   [3]  (e)  identify solid p.   ..   [2]",
            "6": "6 0620/52/o/n/19 \u00a9 ucles 2019  tests on solid q  (f)\t\tdo\ta\tflame\ttest\ton\ta\tsmall\tsample\tof\tsolid\t q.   record your observations.   ..   [1]  (g)  add the rest of solid q to about 5 cm3 of distilled water in a test-tube. stopper the test-tube and  shake the mixture to dissolve solid q.   add a few drops of dilute nitric acid and about 1 cm3 of aqueous silver nitrate to this solution.   record your observations.   ..   [1]  (h)  identify solid q.   ..   [2]  [total: 15]",
            "7": "7 0620/52/o/n/19 \u00a9 ucles 2019 [turn over 3  the table gives some information about the properties of three substances found in a hand cream. substancereaction with dilute nitric acid polystyrene beads no reaction calcium carbonate reacts and dissolves sodium\tfluoride dissolves   use the information in the table to plan an experiment to obtain a pure, dry sample of   polystyrene beads from this mixture of substances.   you are provided with a mixture of the three substances and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/52/o/n/19 \u00a9 ucles 2019blank page",
            "9": "9 0620/52/o/n/19 \u00a9 ucles 2019blank page",
            "10": "10 0620/52/o/n/19 \u00a9 ucles 2019blank page 2  you are provided with two metal salt solutions, e and f.   carry out the following tests on e and f, recording all of your observations at each stage.",
            "11": "11 0620/52/o/n/19 \u00a9 ucles 2019notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh 4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "12": "12 0620/52/o/n/19 \u00a9 ucles 2019tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w19_qp_53.pdf": {
            "1": "read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units.notes for use in qualitative analysis are provided on pages 7 and 8. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/53 paper 5  practical test october/november 2019  1 hour 15 minutes candidates answer on the question paper. additional materials: as listed in the confidential instructionscambridge assessment international education cambridge international general certificate of secondary education this document consists of 8 printed pages. [turn overib19 11_0620_53/2rp\u00a9 ucles 2019 *6075832942* this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.for examiner\u2019s use 1 23 total",
            "2": "2 0620/53/o/n/19 \u00a9 ucles 2019 1  you are going to investigate the reaction between dilute hydrochloric acid and three different  concentrations of aqueous sodium hydroxide, labelled r, s and t.   read all the instructions carefully before starting the experiments.   instructions  you are going to do three experiments.   experiment 1  \u25cf fill the burette up to the 0.0 cm3 mark with dilute hydrochloric acid.  \u25cf use the measuring cylinder to pour 20 cm3 of solution r into the conical flask.  \u25cf add six drops of methyl orange indicator to the conical flask.  \u25cf add dilute hydrochloric acid from the burette to the conical flask, 1.0 cm3 at a time, while  swirling the conical flask, until the solution just changes colour.  \u25cf record the burette readings in the table.  \u25cf empty the conical flask and rinse it with distilled water.  experiment 2  \u25cf repeat experiment 1 using solution s instead of solution r.  \u25cf record the burette readings in the table.   experiment 3  \u25cf repeat experiment 1 using solution t instead of solution r.  \u25cf record the burette readings in the table.  (a)  complete the table. burette reading / cm3 experiment 1 using solution rexperiment 2 using solution sexperiment 3 using solution t final burette reading initial burette reading volume used  [4]  (b)  what colour change is observed in the conical flask at the end-point?  from  to     [2]  (c)  suggest why universal indicator is not a suitable indicator to use in these experiments.      ..   [1]",
            "3": "3 0620/53/o/n/19 \u00a9 ucles 2019 [turn over  (d) (i) complete the sentences.   experiment  needed the smallest volume of dilute hydrochloric acid to change the  colour of the methyl orange indicator.   experiment  needed the largest volume of dilute hydrochloric acid to change the  colour of the methyl orange indicator.  [1]  (ii)  determine the simplest whole number ratio of volumes of dilute hydrochloric acid used in  experiments 1 and 2.   experiment 1  :  experiment 2  [1]  (iii)  deduce the order of concentrations of the solutions of aqueous sodium hydroxide,   r, s and t.  most concentrated        least concentrated     [1]  (e)  what would be the effect on the results, if any, if the solutions of aqueous sodium hydroxide  were warmed before adding the dilute hydrochloric acid? give a reason for your answer.  effect on the results  ...  reason    [2]  (f)  suggest how the reliability of the results could be checked.      ..   [2]  (g)  suggest a different method, not involving an indicator, of finding the order of concentrations of  the solutions of aqueous sodium hydroxide, r, s and t.         ..   [3]  [total: 17]",
            "4": "4 0620/53/o/n/19 \u00a9 ucles 2019 2  you are provid ed with solid u and liquid v.   do the following tests on solid u and liquid v, recording all of your observations at each stage.   tests on solid u  (a)  do a flame test on a small sample of solid u.   record your observations.   ..   [1]   add the rest of solid u to about 10 cm3 of distilled  water in a boiling tube. stopper the boiling tube  and shake the mixture to dissolve solid u and form solution u.  (b)  describe the colour of solution u.   ..   [1]   divide solution u into three approximately equal portions in three test- tubes.  (c) (i)  add a few drops of aqueous sodium hydroxide to the first portion of solution u.   record your observations.   ...   [1]  (ii)  now add an excess of aqueous sodium hydroxide to this mixture.   record your observations.   ...   [1]  (d) (i)  add a few drops of aqueous ammonia to the second portion of solution u.   record your observations.   ...   [2]  (ii)  now add an excess of aqueous ammonia to this mixture.   record your observations.   ...   [1]  (e)  add a few drops of dilute nitric acid and about 1 cm3 of aqueous barium nitrate to the third  portion of solution u. leave to stand for 5 minutes.   record your observations.   ..   [2]  (f)  solid u contains three different ions.   what conclusions can you draw about the ions present in solid u?      ..   [3]",
            "5": "5 0620/53/o/n/19 \u00a9 ucles 2019 [turn over   tests on liquid v  (g)  describe the appearance of liquid v.   record your observations.   ..   [1]  (h)  use a teat pipette to place a few drops of liquid v onto a watch-glass. put the stopper back into  the test-tube of liquid v. use a lighted splint to touch the surface of liquid v carefully.   record your observations.   ..   [1]   (i)  use a spatula to transfer a small crystal of iodine carefully into the rest of liquid v in the  stoppered test-tube. put the stopper back into the test-tube and shake the test-tube.   record your observations.      ..   [2]  (j)  draw one conclusion about liquid v.   ..   [1]  [total: 17]",
            "6": "6 0620/53/o/n/19 \u00a9 ucles 2019 3  potassium nitrate and ammonium chloride are two salts. the energy change when they each  dissolve in water is endothermic.   plan an experiment to show which of these two salts produces the larger endothermic energy  change per gram.   your answer should include:  \u25cf any measurements you would take and record  \u25cf how the results could be used to draw a conclusion.   you are provided with potassium nitrate and ammonium chloride, distilled water and common  laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "7": "7 0620/53/o/n/19 \u00a9 ucles 2019notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide produced chloride (c l  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratewhite ppt. bromide (br  \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitratecream ppt. iodide ( i \u2013) [in solution]acidify with dilute nitric acid, then add aqueous silver nitrateyellow ppt. nitrate (no 3\u2013) [in solution]add aqueous sodium hydroxide, then aluminium foil; warm carefullyammonia produced sulfate (so 42\u2013) [in solution]acidify, then add aqueous barium nitratewhite ppt. sulfite (so 32\u2013) add dilute hydrochloric acid, warm gently and test for the presence ofsulfur dioxidesulfur dioxide produced will turn acidified aqueous potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., insoluble in excess ammonium (nh 4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron( ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a colourless solutionwhite ppt., soluble in excess, giving a colourless solution",
            "8": "8 0620/53/o/n/19 \u00a9 ucles 2019tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment  international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w19_qp_61.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib19 11_0620_61/2rp \u00a9 ucles 2019 *2909684625* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/61 paper 6  alternative to practical october/november 2019  1 hour candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/61/o/n/19 \u00a9 ucles 2019 1  the apparatus shown was used to investigate the products formed when ethanol, c2h5oh, burns  in air. limewaterto suction pump iceethanol u-tube water  (a)  complete the box to name the apparatus. [1]  (b)  explain why water collects in the u-tube.      ..   [2]  (c)  state a chemical test for water.  test  .  observations  ..  [2]  (d)  what is the purpose of the suction pump?      ..   [1]  (e)  predict the change seen in the test-tube containing the limewater. explain your prediction.         ..   [2]  [total: 8]",
            "3": "3 0620/61/o/n/19 \u00a9 ucles 2019 [turn over 2  a student investigated the rate of reaction between dilute nitric acid and an excess of  solid magnesium carbonate at room temperature.   the apparatus was set up as shown in the diagram. \t\ta\tsmall\ttest\u2011tube\tcontaining\tmagnesium\tcarbonate\twas\tsuspended\tin\tthe\tconical\tflask. watersolid magnesiumcarbonateinverted 250  cm3 measuring cylinder dilute nitric acid   50 cm3\tof\tdilute\tnitric\tacid\twas\tadded\tto\tthe\tconical\tflask.\tthe\tcontents\t of\tthe\ttest\u2011tube\t were\t released,\t allowing\t the\tsolid\tmagnesium\t carbonate\t to\tmix\twith\tthe\tdilute\tnitric\tacid.\ta\tstop\u2011clock\t was\t started and the volume of gas collected in the inverted measuring cylinder was measured every  10 seconds for 80 seconds.",
            "4": "4 0620/61/o/n/19 \u00a9 ucles 2019  (a)  use the inverted measuring cylinder diagrams to record the volume of gas collected in the  table. 0time  / sinverted measuring cylinder diagramtotal volume of gas collected  / cm3 1030 25 20 10 5 0 2050 45 40 3065 60 55 4070 6560 50807570 608075 70 7080 7570 808075 70  [2]",
            "5": "5 0620/61/o/n/19 \u00a9 ucles 2019 [turn over  (b)  plot the results on the grid. draw a smooth line graph. 80 70 60 5040 30 2010 0 01 02 0 time  / stotal volum e of gas collected / cm3 30 40 50 60 70 80  [3]  (c) (i)  one of the points is anomalous.   circle this point on your graph. [1]  (ii)  from your graph ,\tdeduce\tthe\ttime\ttaken\tto\tcollect\t40\t cm3 of gas.   show clearly on the grid \thow\tyou\tworked\tout\tyour\tanswer.  .. s  [2]",
            "6": "6 0620/61/o/n/19 \u00a9 ucles 2019  (d)  state one possible source of error in this experiment. suggest one improvement to reduce this  source of error.  source of error  ...  improvement  ..  [2]  (e)  the average rate of the reaction can be calculated using the equation shown. average rate of reaction =volume of gas collected / cm3 time\ttaken\t /\ts  (i)  calculate the volume of gas collected between 10 seconds and 30 seconds.   ...   [1]  (ii)  calculate the average rate of reaction between 10 seconds and 30 seconds. include the  unit in your answer.  average rate of reaction = ..  unit = ..  [2]  (f)  the student calculated that the total volume of gas collected in this reaction would be 85 cm3.   suggest and explain why the actual volume of gas collected was different from 85 cm3.         ..   [2]  (g)\t\tsketch\t on the grid the graph you would expect if the experiment were repeated at a lower  temperature. label this graph as l. [2]  [total: 17]",
            "7": "7 0620/61/o/n/19 \u00a9 ucles 2019 [turn over 3  two substances, solid a and solid b, were analysed. solid a was zinc nitrate.   tests were done on the substances.   tests on solid a   complete the expected observations.   solid a\twas\tadded\tto\tdistilled\t water\tand\tthe\tmixture\tshaken\tto\tdissolve\t solid\t a and produce  solution a. solution a was divided into three equal portions in three test-tubes.  (a) (i)\t\ta\tfew\tdrops\tof\taqueous\tsodium\thydroxide\twere\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t a.  observations  ..   [2]  (ii)  an excess of aqueous sodium hydroxide was then added to this mixture.   observations  .   [1]  (b) (i)  a few drops of aqueous ammonia were added to the second portion of solution a.  observations  .   [1]  (ii)  an excess of aqueous ammonia was then added to this mixture.  observations  .   [1]  (c)  aluminium foil and aqueous sodium hydroxide were added to the third portion of solution a.  the mixture was heated and the gas produced was tested with litmus paper.  observations  ..   ..   [2]   tests on solid b   some of the tests and observations are shown. tests on solid b observations test 1 a\tflame\ttest\twas\tdone\ton\tsolid\t b. red\tflame test 2solid b was dissolved in water. dilute nitric acid and aqueous silver nitrate were  added to the solution.yellow precipitate formed  (d)  identify solid b.   ..   [2]  [total: 9]",
            "8": "8 0620/61/o/n/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. 4  iodine dissolves in two different solvents: ethanol and hexane. \t\tplan\tan\texperiment\tto\tfind\tout\tin\twhich\tsolvent\tiodine\tis\tthe\tmost\tsoluble\tat\troom\ttemperature.   you are provided with iodine, the two solvents and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]"
        },
        "0620_w19_qp_62.pdf": {
            "1": "this document consists of 8 printed pages and 4 blank pages. [turn overib19 11_0620_62/2rp \u00a9 ucles 2019 *9615262731* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/62 paper 6  alternative to practical october/november 2019  1 hour candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/62/o/n/19 \u00a9 ucles 2019blank page",
            "3": "3 0620/62/o/n/19 \u00a9 ucles 2019 [turn over 1\t\ta\tstudent\tdid\ta\tsingle\ttitration\tto\tfind\tthe\tconcentration\tof\ta\tsolution\tof\tdilute\tsulfuric\tacid. \t\tthe\tstudent\tadded\t25.0\tcm3\tof\taqueous\t sodium\thydroxide\t to\ta\tconical\tflask,\tfollowed\t by\ta\tfew\t drops\tof\tindicator.\t dilute\tsulfuric\tacid\twas\tthen\tadded\tto\tthe\taqueous\t sodium\thydroxide\t until\tthe\t solution\twas\tneutral. \t\tthe\tapparatus\tused\tis\tshown\tin\tthe\tdiagram. aqueous sodium hydroxidedilute sulfuric acid  (a)  complete\tthe\tboxes\tto\tname\tthe\tapparatus.\t [2]  (b)\t\tname\ta\tsuitable\tindicator\tto\tuse\tin\tthe\ttitration\tand\t give\tthe\tcolour\tchange. \t indicator\t \t. \t colour\tchange\tfrom\t\tto\t \t... \t [2]  (c)  what\treadings\tshould\tthe\tstudent\ttake\twhen\tdoing\tthis\tsingle\ttitration?  \t.. \t\t[2]  (d)\t\tafter\tthe\ttitration,\t the\tstudent\t discarded\t the\tcontents\t of\tthe\tconical\tflask\tand\trinsed\tthe\t conical\tflask\twith\tdistilled\twater. \t \tsuggest\t and\texplain\twhat\twould\tbe\tthe\teffect,\tif\tany,\ton\tthe\ttitration\tvalues\tif\tthe\tconical\tflask\t was\tnot\tdried\tbefore\trepeating\tthe\ttitration.  \t  \t  \t.. \t\t[2] \t [total:\t8]",
            "4": "4 0620/62/o/n/19 \u00a9 ucles 2019 2\t\ta\tstudent\tinvestigated\t the\ttemperature\t changes\t when\ttwo\tdifferent\t solids,\t n and o,\t dissolve\t in\t water. \t\ttwo\texperiments\twere\tdone.   experiment 1  \u25cf\tusing\ta\tmeasuring\tcylinder,\t30\t cm3\tof\tdistilled\twater\twas\tpoured\tinto\ta\tpolystyrene\tcup.  \u25cf\tthe\tinitial\ttemperature\tof\tthe\tdistilled\twater\twas\tmeasured.  \u25cf solid n\twas\tadded\tto\tthe\tdistilled\twater,\ta\ttimer\tstarted\tand\tthe\tmixture\twas\tstirred\twith\ta\t stirring\tthermometer.  \u25cf\tthe\ttemperature\t of\tthe\tmixture\twas\tmeasured\t every\t30\tseconds\t for\tthree\tminutes\t(180\tseconds).  (a)\t\tuse\tthe\tthermometer\tdiagrams\tto\trecord\tthe\ttemperatures\tin\tthe\ttable. thermometer diagramtime  / s0 30 60 90 120 150 180 temperature of mixture  / \u00b0c25 20 1525 20 1525 20 1530 25 2030 25 2030 25 2030 25 20 \t [2]  experiment 2 \t\texperiment\t1\twas\trepeated\tusing\ta\tnew\tpolystyrene\tcup\tand\tsolid\t o\tinstead\tof\tsolid\t n.  (b)\t\tuse\tthe\tthermometer\tdiagrams\tto\trecord\tthe\ttemperatures\tin\tthe\ttable. thermometer diagramtime  / s0 30 60 90 120 150 180 temperature of mixture  / \u00b0c30 25 2020 15 1020 15 1020 15 1010 5 010 5 020 15 10 \t [2]",
            "5": "5 0620/62/o/n/19 \u00a9 ucles 2019 [turn over  (c)\t\tplot\tthe\tresults\tfor\texperiments\t1\tand\t2\ton\tthe\tgrid. \tdraw\ttwo\tsmooth\tline\tgraphs. \t \tclearly\tlabel\tyour\tgraphs. 30 20 10 0 03 06 0 time  / stemperature of mixture / \u00b0c 90 120 150 180 210 240 \t [3]  (d) (i)  from your graph,\t deduce\tthe\ttime\ttaken\tfor\tthe\tinitial\ttemperature\t of\tthe\tsolution\t in\t experiment\t2\tto\tchange\tby\t3\t \u00b0c. \t \tshow\tclearly\t on the grid \thow\tyou\tworked\tout\tyour\tanswer. \t ..\ts\t\t[3]  (ii)\t\textend\tyour\tgraph\tfor\texperiment\t1\tto\tgive\tthe\texpected\ttemperature\tof\tthe\tmixture\tafter\t 240\tseconds. \t ..\t \u00b0c\t\t[2]  (e)\t\tis\tthe\tenergy\tchange\tin\texperiment\t2\texothermic\tor\tendothermic?\texplain\tyour\tanswer.  \t  \t.. \t\t[1]",
            "6": "6 0620/62/o/n/19 \u00a9 ucles 2019  (f)  state two\tpossible\t sources\t of\terror\tin\tthese\texperiments.\t suggest\t two\timprovements\t to\t reduce\teach\tof\tthese\tsources\tof\terror. \t source\tof\terror\t1\t\t  \t improvement\t1\t \t... \t source\tof\terror\t2\t\t  \t improvement\t2\t \t... \t [4] \t [total:\t17]",
            "7": "7 0620/62/o/n/19 \u00a9 ucles 2019 [turn over 3\t\ttwo\tsubstances,\tsolid\t p and solid q,\twere\tanalysed.\tsolid\tp\twas\tcopper( ii)\tnitrate. \t\ttests\twere\tdone\ton\tsolid\t p and solid q.   tests on solid p \t\tcomplete\tthe\texpected\tobservations.  (a)\t\ta\tflame\ttest\twas\tdone\ton\tsolid\t p. \t observations\t \t \t\t[1]   solid p\twas\tadded\tto\tdistilled\twater\tand\tthe\tmixture\tshaken\tto\tdissolve\t solid\t p\tand\tform\tsolution\t p.\t solution p\twas\tdivided\tinto\tthree\tequal\tportions\tin\ttwo\ttest\u2011tubes\tand\tone\tboiling\ttube.  (b)  an\texcess\tof\taqueous\t sodium\thydroxide\t was\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t p in a  test\u2011tube. \t observations\t \t \t\t[1]  (c) (i)\t \ta\tfew\tdrops\tof\taqueous\t ammonia\t were\tadded\tto\tthe\tsecond\tportion\tof\tsolution\t p in a  test\u2011tube. \t observations\t \t. \t\t[1]  (ii)\t\tan\texcess\tof\taqueous\tammonia\twas\tthen\tadded\tto\tthis\tmixture. \t observations\t \t. \t\t[2]  (d)\t\taluminium\t foil\tand\taqueous\t sodium\thydroxide\t were\tadded\tto\tthe\tthird\tportion\tof\tsolution\t p in  a\tboiling\ttube.\t the\tmixture\twas\theated\tand\tthe\tgas\tproduced\ttested. \t observations\t \t..  \t.. \t\t[2]",
            "8": "8 0620/62/o/n/19 \u00a9 ucles 2019  tests on solid q \t\tsome\tof\tthe\ttests\tand\tobservations\tare\tshown. tests on solid q observations test 1 a\tflame\ttest\twas\tdone\ton\tsolid\t q. lilac\tcolour test 2solid q\twas\tdissolved\tin\twater.dilute\tnitric\tacid\tand\taqueous\t silver\tnitrate\twere\t added\tto\tthe\tsolution.cream\tprecipitate\tformed  (e)  identify\tsolid\tq.  \t.. \t\t[2] \t [total:\t9]",
            "9": "9 0620/62/o/n/19 \u00a9 ucles 2019 [turn over 4\t\tthe\ttable\tgives\tsome\tinformation\t about\tthe\tproperties\t of\tthree\tsubstances\t found\tin\ta\thand\tcream. substance reaction\twith\tdilute\tnitric\tacid polystyrene\tbeads no\treaction calcium\tcarbonate reacts\tand\tdissolves sodium\tfluoride dissolves \t\tuse\tthe\tinformation\t in\tthe\ttable\tto\tplan\tan\texperiment\t to\tobtain\ta\tpure,\tdry\tsample\t of\t  polystyrene\tbeads\tfrom\tthis\tmixture\tof\tsubstances. \t\tyou\tare\tprovided\twith\ta\tmixture\tof\tthe\tthree\tsubstances\tand\tcommon\tlaboratory\tapparatus.  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t . \t\t[6]",
            "10": "10 0620/62/o/n/19 \u00a9 ucles 2019blank page",
            "11": "11 0620/62/o/n/19 \u00a9 ucles 2019blank page",
            "12": "12 0620/62/o/n/19 \u00a9 ucles 2019blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w19_qp_63.pdf": {
            "1": "this document consists of 8 printed pages. [turn overib19 11_0620_63/2rp \u00a9 ucles 2019 *1868827148* read these instructions first write your centre number, candidate number and name on all the work you hand in. write in dark blue or black pen.you may use an hb pencil for any diagrams or graphs.do not use staples, paper clips, glue or correction fluid.do not write in any barcodes. answer all questions. electronic calculators may be used.you may lose marks if you do not show your working or if you do not use appropriate units. at the end of the examination, fasten all your work securely together. the number of marks is given in brackets [  ] at the end of each question or part question.chemistry  0620/63 paper 6  alternative to practical october/november 2019  1 hour candidates answer on the question paper. no additional materials are required.cambridge assessment international education cambridge international general certificate of secondary education this syllabus is regulated for use in england, wales and northern ireland as a cambridge international level 1/level 2 certificate.",
            "2": "2 0620/63/o/n/19 \u00a9 ucles 2019 1  hydrogen peroxide, h2o2(aq), decomposes slowly to form water and oxygen. 2h2o2(aq)    2h2o(l)  +  o2(g)   the addition of 0.5 g of manganese( iv) oxide speeds up this decomposition. manganese( iv) oxide  is an insoluble solid.   the apparatus shown was used to follow the rate of decomposition of hydrogen peroxide. the  hydrogen\u00a0peroxide\u00a0was\u00a0added\u00a0to\u00a0the\u00a0conical\u00a0flask\u00a0and\u00a0a\u00a0stop\u2011watch\u00a0was\u00a0started. waterhydrogen peroxide 0.5 g manganese( iv) oxide  (a)  complete the box to name the apparatus. [1]  (b)\u00a0 \u00a0what\u00a0measurements\u00a0should\u00a0be\u00a0taken\u00a0to\u00a0follow\u00a0the\u00a0rate\u00a0of\u00a0the\u00a0reaction?      ..   [2]  (c)  the rate of the reaction decreases over time. after 5 minutes the rate of reaction is zero.  (i)\u00a0 \u00a0why\u00a0does\u00a0the\u00a0rate\u00a0of\u00a0reaction\u00a0decrease?   ...   [1]  (ii)  explain why the rate of reaction is zero after 5 minutes.   ...   [1]",
            "3": "3 0620/63/o/n/19 \u00a9 ucles 2019 [turn over  (d) (i)  the manganese( iv) oxide acts as a catalyst.   how could a student separate the catalyst from the reaction mixture at the end of the  reaction?   ...   [1]  (ii)  suggest how the student could show that the catalyst separated in (d)(i) is unchanged at  the end of the reaction.   .   .   .   ...   [3]  [total: 9]",
            "4": "4 0620/63/o/n/19 \u00a9 ucles 2019 2  a student investigated the reaction between dilute hydrochloric acid and three different concentrations  of aqueous sodium hydroxide, labelled r, s and t.   three experiments were done.  experiment 1  \u25cf a burette was filled with dilute hydrochloric acid. the initial burette reading was measured.  \u25cf using a measuring cylinder, 20 cm3 of solution r\u00a0was\u00a0poured\u00a0into\u00a0a\u00a0conical\u00a0flask.  \u25cf\u00a0six\u00a0drops\u00a0of\u00a0methyl\u00a0orange\u00a0indicator\u00a0were\u00a0added\u00a0to\u00a0the\u00a0conical\u00a0flask.  \u25cf dilute hydrochloric acid was added from the burette, until the solution just changed colour.  \u25cf the final burette reading was measured. 0 1 2 initial10 11 12 final  experiment 2  \u25cf experiment 1 was repeated but using 20 cm3 of solution s instead of solution r. 2 3 4 initial23 24 25 final  experiment 3  \u25cf experiment 1 was repeated but using 20 cm3 of solution t instead of solution r. 1 2 3 initial5 6 7 final",
            "5": "5 0620/63/o/n/19 \u00a9 ucles 2019 [turn over  (a)  use the burette diagrams to record all the burette readings in the table. burette reading / cm3 experiment 1 using solution rexperiment 2 using solution sexperiment 3 using solution t final\u00a0burette\u00a0reading initial burette reading volume used  [4]  (b)\u00a0 \u00a0what\u00a0colour\u00a0change\u00a0is\u00a0observed\u00a0in\u00a0the\u00a0conical\u00a0flask \u00a0at\u00a0the\u00a0end\u2011point?  from ... to  ...  [2] (c)  suggest why universal indicator is not a suitable indicator in these experiments.      ..   [1]  (d) (i)  complete the sentences below.   experiment  needed the smallest volume of dilute hydrochloric acid to change the  colour of the indicator.   experiment  needed the largest volume of dilute hydrochloric acid to change the  colour of the indicator.  [1]  (ii)  determine the simplest whole number ratio of volumes of dilute hydrochloric acid used in  experiments 1 and 2.  experiment 1  :  experiment 2 [1]  (iii)  deduce the order of concentrations of the solutions of aqueous sodium hydroxide,   r, s and t.  most concentrated ..   ..  least concentrated ..  [1] (e)  what would be the effect on the results, if any, if the solutions of aqueous sodium hydroxide  were\u00a0warmed\u00a0before\u00a0adding\u00a0the\u00a0dilute\u00a0hydrochloric\u00a0acid?\u00a0give\u00a0a\u00a0reason\u00a0for\u00a0your\u00a0answer.  effect on the results  ...  reason    [2]",
            "6": "6 0620/63/o/n/19 \u00a9 ucles 2019  (f)\u00a0 \u00a0suggest\u00a0how\u00a0the\u00a0reliability\u00a0of\u00a0the\u00a0results\u00a0could\u00a0be\u00a0checked.            ..   [2]  (g)  suggest a different method, not\u00a0 involving\u00a0 an\u00a0indicator,\u00a0 of\u00a0finding\u00a0the\u00a0order\u00a0of\u00a0concentrations\u00a0 of\u00a0 the solutions of aqueous sodium hydroxide, r, s and t.         ..   [3]  [total: 17]",
            "7": "7 0620/63/o/n/19 \u00a9 ucles 2019 [turn over 3  two substances, solid u and liquid v, were analysed. solid u was chromium( iii) nitrate.   tests were done on solid u and liquid v.   tests on solid u   complete the expected observations.   solid u\u00a0was\u00a0added\u00a0to\u00a0distilled\u00a0water\u00a0and\u00a0shaken\u00a0 to\u00a0dissolve\u00a0solid\u00a0u and form solution u.  (a)  describe the colour of solution u.   ..   [1]   solution u\u00a0was\u00a0divided\u00a0into\u00a0three\u00a0equal\u00a0portions\u00a0 in\u00a0three\u00a0test\u2011tubes.  (b) (i)\u00a0 \u00a0 a\u00a0few\u00a0drops\u00a0of\u00a0aqueous\u00a0 sodium\u00a0hydroxide\u00a0 were\u00a0added\u00a0to\u00a0the\u00a0first\u00a0portion\u00a0of\u00a0solution\u00a0 u until  a change was seen.  observations  .   [2]  (ii)  an excess of aqueous sodium hydroxide was then added to the mixture.  observations  .   [1]  (c)  an excess of aqueous ammonia was added to the second portion of solution u.  observations  .   [1]  (d)  aluminium foil and aqueous sodium hydroxide were added to the third portion of solution u.  the mixture was heated and the gas produced was tested.  observations  ...   ..   [2]  tests on liquid v   one of the tests done on liquid v and the observations made are shown. tests on liquid v observations a lighted splint was used to touch about 1 cm3  of liquid v.liquid v\u00a0set\u00a0on\u00a0fire\u00a0and burned\u00a0with\u00a0a\u00a0smoky\u00a0blue\u00a0flame  (e)  draw one conclusion about liquid v.   ..   [1]  [total: 8]",
            "8": "8 0620/63/o/n/19 \u00a9 ucles 2019permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series.cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. 4  potassium nitrate and ammonium chloride are two salts. the energy change when they each  dissolve in water is endothermic.   plan an experiment to show which of these two salts produces the larger endothermic energy  change per gram.   your answer should include:  \u25cf\u00a0any\u00a0measurements\u00a0you\u00a0would\u00a0take\u00a0and\u00a0record  \u25cf how the results could be used to draw a conclusion.   you are provided with potassium nitrate and ammonium chloride, distilled water and common  laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]"
        }
    },
    "2020": {
        "0620_m20_qp_12.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 03_0620_12/4rp   \u00a9 ucles 2020   [turn ove r   *3454751695 *cambridge igcse\u2122       chemistry 0620/12     paper 1 multiple choice (core)  february/march 2020     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate num ber on the multiple choice answer sheet in the  spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.     ",
            "2": "2  \u00a9 ucles 2020 0620/12/f/m/20  1 which row represents the particles of a gas colliding most frequently?     pressure temperature  a high high  b high low  c low high  d low low      2 which test is used to show that a sample of water is pure?  a evaporate the water to see if any solids remain.  b heat the water to check its boiling point.  c test with anhydrous cobalt( ii) chloride.  d use universal indicator paper to check its ph.      3 which piece of apparatus is used to measure 1.5  cm3 of a solution accurately?  a 25  cm3 measuring cylinder  b 25  cm3 pipette  c 50  cm3 measuring cylinder  d 50  cm3 burette      4 a representation of an atom is shown.    + ++ + ++\u2013 \u2013\u2013\u2013 \u2013\u2013     what is the nucleon number of this atom?  a 6 b 7 c 12 d 13     ",
            "3": "3     \u00a9 ucles 2020 0620/12/f/m/20 [turn over  5 lithium reacts with fluorine to form the compound lithium fluoride.    which statement about this reaction is correct?  a each fluorine atom gains one electron.  b each fluorine atom gains two or more electrons.  c each fluorine atom loses one electron.  d each fluorine atom loses two or more electrons.     6 ammonia, nh 3, is a covalent molecule.    which diagram shows the outer shell electron arrangement in a molecule of ammonia?    na h hh nb h hh nc h hh nd h hh       7 which row describes the structure and a use of diamond?     structure use  a ionic in cutting tools  b ionic lubricant  c macromolecular in cutting tools  d macromolecular lubricant     ",
            "4": "4  \u00a9 ucles 2020 0620/12/f/m/20  8 methane, ch 4, burns in air to form carbon dioxide and water.    what is the balanced equation for this reaction?  a ch 4(g)  +  o 2(g)  \u2192  co 2(g)  +  2h 2o(g)  b ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(g)  c ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  h 2o(g)  d ch 4(g)  +  3o 2(g)  \u2192  co 2(g)  +  2h 2o(g)      9 which statement about electrolysis is correct?  a chemical energy is conver ted to electrical energy.  b electrons flow through the electrolyte.  c ionic compounds are broken down.  d metals are formed at the positive electrode.     10 which energy level diagram shows the reaction that will give out the most energy?    energy progress of reactionc reactantsproducts energy progress of reactiond reactants productsenergy progress of reactiona reactants productsenergy progress of reactionb reactantsproducts      ",
            "5": "5     \u00a9 ucles 2020 0620/12/f/m/20 [turn over  11 which change is a physical change?  a copper( ii) carbonate changes colour from green to black when it is heated, and stays black  when it cools.  b ethanol reacts with oxygen to form carbon dioxide and water.  c hydrogen peroxide decomposes into water and oxygen when it is boiled.  d ice forms liquid water when it is heated.      12 marble chips (calcium carbonate) react with hydrochloric acid in an exothermic reaction.    calcium carbonate  +  hydrochloric acid  \u2192  calcium chloride  +  water  +  carbon dioxide    when excess marble chips are added to dilute hydrochloric acid the rate of the reaction starts off fast, then gets slower until the reaction stops.    why does the reaction rate get slower?  a the concentration of the hydrochloric acid is decreasing.  b the concentration of calcium chloride is increasing.  c the calcium carbonate is completely used up.  d the temperature of the mixture decreases.    13 the diagram shows the change from an anhydrous salt to its hydrated form.    hydrated salt anhydrous saltforward reverse    which statement is correct?  a the forward reaction requires heat and water.  b the forward reaction requires water only.  c the reverse reaction requires heat and water.  d the reverse reaction requires water only.    ",
            "6": "6  \u00a9 ucles 2020 0620/12/f/m/20  14 a violent reaction occurs when a mixture of chromium( iii) oxide and aluminium is ignited with a  magnesium fuse as shown.    cruciblemagnesium fuse mixture of chromium( iii) oxide and aluminium sand    the equation for the reaction is shown.    cr2o3  +  2a l  \u2192  2cr  +  a l 2o3    which substance is oxidised in the reaction?  a aluminium  b aluminium oxide  c chromium  d chromium( iii) oxide     15 a farmer\u2019s soil is acidic.    which substance should the farmer add to neutralise the soil?  a ammonium sulfate  b calcium oxide  c hydrochloric acid  d npk fertiliser    ",
            "7": "7     \u00a9 ucles 2020 0620/12/f/m/20 [turn over  16 three elements, x, y and z, are burned in oxygen.    the oxides formed are dissolved in water and the ph of the solutions measured.    the results are shown.     ph of oxide solution  x 2.0  y 14.0  z 8.0    which statements are correct?    1 element x could be sulfur.  2 element y could be sodium. 3 element z is a non-metal. 4 no metal elements were used.    a 1 only b 1 and 2 c 2 and 3 d 3 and 4    17 the following substances can be reacted together to prepare salts.    1 copper( ii) oxide and excess hydrochloric acid  2 hydrochloric acid and excess sodium hydroxide  3 hydrochloric acid and excess zinc carbonate    in which reactions can the excess reactant be separated from the solution by filtration?  a 1 and 2 b 1 and 3 c 2 and 3 d 3 only    ",
            "8": "8  \u00a9 ucles 2020 0620/12/f/m/20  18 salt s is dissolved in water and three tests are carried out on the solution.     test result  1     aqueous sodium  hydroxide is added   green precipitate formed,  insoluble in excess sodium  hydroxide  2 dilute nitric acid is added no reaction  3   aqueous barium nitrate is added  to the acidified solution from test 2 white precipitate formed      what is the identity of s?  a copper( ii) chloride  b copper( ii) sulfate  c iron( ii) chloride  d iron( ii) sulfate      19 which statement about the periodic table is correct?  a most metallic elements are on the left.  b elements in the same period have the same number of outer electrons.  c elements on the left are usually gases.  d the relative atomic mass of the elements increases from right to left.     20 the diagram shows elements w, x, y and z in a section of the periodic table.    x yzw     which statement about the reactivity of the elements is correct?  a x is more reactive than y, and w is more reactive than z.  b x is more reactive than y, and z is more reactive than w.  c y is more reactive than x, and w is more reactive than z.  d y is more reactive than x, and z is more reactive than w.    ",
            "9": "9     \u00a9 ucles 2020 0620/12/f/m/20 [turn over  21 some properties of substances are listed.    1 they conduct electricity.  2 they have low densities.  3 they have high melting points.  4 they are malleable.    which properties are shown by transition metals?  a 1 and 3 only b 1 and 4 only c 1, 2 and 3 d 1, 3 and 4    22 which statement about the noble gas argon is correct?  a it burns with a hot flame.  b it is used in airships because of its low density.  c it exists as diatomic molecules.  d it has eight electrons in its outermost shell.    23 sodium is a group i metal.    which property, that is typical of most metals, is not shown by sodium?  a conductor of heat  b high melting point  c malleable  d shiny     ",
            "10": "10  \u00a9 ucles 2020 0620/12/f/m/20  24 manganese, nickel and silver are all metals.    samples of powdered manganese, nickel and silver were placed in separate test-tubes containing dilute hydrochloric acid.    the results are shown.    hydrogen hydrogen manganese nickel silver    what is the order of reactivity of the metals, most reactive to least reactive?  a manganese \u2192 nickel \u2192 silver  b manganese \u2192 silver \u2192 nickel  c silver \u2192 manganese \u2192 nickel  d silver \u2192 nickel \u2192 manganese      25 which statement about aluminium is correct?  a aluminium is easy to extract from its ore becaus e it is near the bottom of the reactivity series.  b aluminium is formed when aluminium oxide is heated with carbon.  c bauxite is an important ore of aluminium.  d hematite is an important ore of aluminium.    26 some properties of aluminium are listed.    1 it conducts heat.  2 it has a low density.  3 it is strong. 4 it is resistant to corrosion.    which of these properties make aluminium suitable for making food containers for chilled food products?  a 1, 2 and 4 b 1, 3 and 4 c 1 only d 4 only     ",
            "11": "11     \u00a9 ucles 2020 0620/12/f/m/20 [turn over  27 water is treated at a waterworks to make it fit to drink.    what is present in the water when it leaves the waterworks?  a bacteria only  b bacteria and insoluble substances  c chlorine compounds only  d chlorine compounds and soluble substances    28 sulfur dioxide, carbon monoxide and oxides of nitrogen are common gaseous pollutants found in  the air.    which pollutants contribute to acid rain?  a carbon monoxide and sulfur dioxide  b oxides of nitrogen and sulfur dioxide  c oxides of nitrogen only  d sulfur dioxide only     29 which methods prevent iron from rusting?     coating  with zinc painting washing with  salt water   a \u0016 \u0016 \u0016 key  b \u001a \u0016 \u0016 \u0016= prevents rusting  c \u0016 \u0016 \u001a \u001a= does not prevent rusting  d \u0016 \u001a \u001a       30 fertilisers are mixtures of different compounds used to increase the growth of crops.    which pair of substances contain the three essential elements for plant growth?  a ammonium nitrate and calcium phosphate  b ammonium nitrate and potassium chloride  c ammonium phosphate and potassium chloride  d potassium nitrate and calcium carbonate    ",
            "12": "12  \u00a9 ucles 2020 0620/12/f/m/20  31 which process does not add a greenhouse gas to the atmosphere?  a burning methane  b decomposition of vegetation  c polymerisation  d respiration      32 why is sulfur dioxide used as a food preservative?  a it is a gas at room temperature.  b it is used to make sulfuric acid.  c it kills bacteria.  d it reacts with alkalis.      33 which statements about lime (calcium oxide) and limestone (calcium carbonate) are correct?    1 limestone is used in the manufacture of iron.  2 lime is made by heating limestone. 3 powdered limestone is heated with clay in the production of cement.  4 limestone causes soil to be acidic.    a 1 and 2 only b 2 and 3 only c 1, 2 and 3 d 1, 3 and 4     34 the formulae of two organic compounds, p and q, are shown.    p q   ch 3ch 2ch 2oh ch 3chchch 3    which type of organic compounds are p and q?     p q  a alcohol alkane  b alcohol alkene  c carboxylic acid alkane  d carboxylic acid alkene     ",
            "13": "13     \u00a9 ucles 2020 0620/12/f/m/20 [turn over  35 petroleum is an important raw material that is separated into useful products.    which terms describe petroleum and the method used to separate it?     description separation method  a compound cracking  b compound fractional distillation  c mixture cracking  d mixture fractional distillation      36 which type of compound is a member of a homologous series?  a carbonate  b carboxylic acid  c halogen  d hydroxide    37 which statements about propene are correct?    1 propene contains only single bonds.  2 propene decolourises bromine water.  3 propene is obtained by cracking. 4 propene is a hydrocarbon.    a 1 and 4 b 2, 3 and 4 c 2 and 4 only d 4 only     38 which row describes the production of ethanol and its properties?     can be made  from glucose can be made  from ethene is used as a  fuel is used as a  solvent   a \u0016 \u0016 \u0016 \u0016 key  b \u0016 \u001a \u0016 \u0016 \u0016= yes  c \u001a \u0016 \u0016 \u001a \u001a= no  d \u001a \u0016 \u001a \u0016      ",
            "14": "14  \u00a9 ucles 2020 0620/12/f/m/20  39 which statements about ethanoic acid are correct?    1 it contains a carbon\u2013oxygen double bond.  2 it contains two carbon atoms.  3 it decolourises bromine water.  4 it contains an \u2013oh group.    a 1 and 2 only b 1 and 3 c 1, 2 and 4 d 2, 3 and 4     40 which polymers are natural polymers?    1 carbohydrates  2 poly(ethene) 3 protein    a 1, 2 and 3 b 1 and 3 only c 1 only d 3 only    ",
            "15": "15    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.   cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2020 0620/12/f/m/20  ",
            "16": "16  \u00a9 ucles 2020 0620/12/f/m/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m20_qp_22.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 03_0620_22/5rp   \u00a9 ucles 2020   [turn ove r   *0772987719*cambridge igcse\u2122       chemistry 0620/22     paper 2 multiple choice (extended)  february/march 2020     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate num ber on the multiple choice answer sheet in the  spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.     ",
            "2": "2  \u00a9 ucles 2020 0620/22/f/m/20  1 the formula of methane is ch 4 and the formula of ethane is c 2h6.    which row describes diffusion and the relative rates of diffusion of methane and ethane?     description of diffusion relative rate of diffusion  a     particles move from  a high concentration  to a low concentration ethane diffuses more  quickly than methane    b     particles move from  a high concentration  to a low concentration methane diffuses more  quickly than ethane    c     particles move from  a low concentration  to a high concentration ethane diffuses more  quickly than methane    d    particles move from  a low concentration  to a high concentration methane diffuses more  quickly than ethane        2 which test is used to show that a sample of water is pure?  a evaporate the water to see if any solids remain.  b heat the water to check its boiling point.  c test with anhydrous cobalt( ii) chloride.  d use universal indicator paper to check its ph.      3 chromatography is used to separate and identify the components in both coloured and colourless  mixtures.    for colourless mixtures the chromatogram has to be treated with another chemical.    what is the name of this type of chemical?  a colouring agent  b display agent  c finding agent  d locating agent     ",
            "3": "3     \u00a9 ucles 2020 0620/22/f/m/20 [turn over  4 lithium reacts with fluorine to form the compound lithium fluoride.    which statement about this reaction is correct?  a each fluorine atom gains one electron.  b each fluorine atom gains two or more electrons.  c each fluorine atom loses one electron.  d each fluorine atom loses two or more electrons.      5 c14 6 and c12 6 are isotopes of carbon.    which statement about these isotopes is correct?  a c12 6 is more reactive than c14 6 because the atoms have less mass.  b c12 6 is more reactive than c14 6 because the atoms have different numbers of neutrons.  c the reactions of c12 6 are similar to c14 6 because they have the same number of outer shell  electrons.  d the reactions of c12 6 are similar to c14 6 because they have the same number of protons in  the nucleus.     6 the molecular structure of hydrazine, n 2h4, is shown.    n hh hh n    which description of the bonding in hydrazine is not correct?  a each nitrogen atom has a non-bonding pair of electrons.  b each nitrogen atom has four bonding pairs of electrons.  c each nitrogen atom shares one of its electrons with a nitrogen atom.  d each nitrogen atom shares two of its electrons with hydrogen atoms.     ",
            "4": "4  \u00a9 ucles 2020 0620/22/f/m/20  7 solid x has a high boiling point.    its structure has positive ions surrounded by a sea of electrons.    which other properties does solid x have?  a brittle and an electrical conductor  b brittle and an insulator  c malleable and an electrical conductor  d malleable and an insulator     8 the formulae of some ions are shown.    positive ions negative ions  al 3+ cl \u2013  fe2+ n3\u2013  mg2+ no 3\u2013  na+ o2\u2013  zn2+ so 42\u2013    in which row is the formula not correct?     compound formula  a aluminium oxide a l 2o3  b iron(ii) nitride fe 2n3  c sodium sulfate na 2so 4  d zinc nitrate zn(no 3)2     9 the equation for the decomposition of magnesium nitrate is shown.    2mg(no 3)2(s)  \u2192  2mgo(s)  +  4no 2(g)  +  o 2(g)    which volume of gas is produced when 0.1 moles of magnesium nitrate is decomposed  completely?  a 1.2  dm3 b 4.8  dm3 c 6.0  dm3 d 8.4  dm3     ",
            "5": "5     \u00a9 ucles 2020 0620/22/f/m/20 [turn over  10 which statements about the electrolysis of molten lead( ii) bromide are correct?    1 lead ions move to the anode and are oxidised.  2 lead ions move to the cathode and are reduced. 3 bromide ions move to the anode and are oxidised.  4 bromide ions move to the cathode and are reduced.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     11 aqueous copper( ii) sulfate is electrolysed using carbon electrodes.    which statement is correct?  a bubbles of hydrogen are formed at the anode.  b bubbles of oxygen gas are formed at the cathode.  c copper is deposited at the anode.  d the blue colour of the solution fades.     12 nitrogen trifluoride, nf 3, is used in the manufacture of certain types of solar panels. the equation  for the formation of nitrogen trifluoride is shown.    n2  +  3f 2  \u2192  2nf 3    type of bond bond energy (kj  mol\u20131)  n\u2261n +950  f\u2013f +150  n\u2013f +280    using the table of bond energies, what is the energy change for this reaction?  a \u2013560  kj mol\u20131  b \u2013280  kj mol\u20131  c +280  kj mol\u20131  d +3080  kj mol\u20131    ",
            "6": "6  \u00a9 ucles 2020 0620/22/f/m/20  13 which statements about hydrogen fuel cells are correct?    1 the reaction between hydrogen and oxygen is endothermic.  2 the waste product in a hydrogen fuel cell is water.  3 a chemical reaction in the cell produces hydrogen which is used as the fuel.  4 a hydrogen fuel cell is used to generate electricity.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4    14 which change is a physical change?  a copper( ii) carbonate changes colour from green to black when it is heated, and stays black  when it cools.  b ethanol reacts with oxygen to form carbon dioxide and water.  c hydrogen peroxide decomposes into water and oxygen when it is boiled.  d ice forms liquid water when it is heated.     15 a student adds excess magnesium ribbon to 10  cm3 of 0.5  mol  / dm3 sulfuric acid.    the hydrogen gas is collected and its volume measured every 10 seconds.    the experiment is repeated using the same mass of magnesium ribbon with 5  cm3 of 0.5  mol  / dm3  sulfuric acid added to 5  cm3 of water.    which graph shows the results of the second experiment?    250 200150100 50 0 0 50 100 150 200 250 time  / secondsvolume of hydrogen  / cm3a b c doriginal experiment      ",
            "7": "7     \u00a9 ucles 2020 0620/22/f/m/20 [turn over  16 an equilibrium reaction is shown.    n2o4(g)    2no 2(g)    the forward reaction is endothermic.    what is the effect of changing the temperature and pressure on the equilibrium position?     increasing temperature increasing pressure  a moves to the left moves to the left  b moves to the left moves to the right  c moves to the right moves to the left  d moves to the right moves to the right      17 in which reaction is the underlined compound acting as a reducing agent?  a co 2  +  c  \u2192  2co  b 2cuo  +  c  \u2192  2cu  +  co 2  c fe 2o3  +  3co  \u2192  2fe  +  3co 2  d caco 3  +  2hc l  \u2192  cac l 2   +   h 2o   +   co 2     18 x, y and z are oxides of elements in the same row of the periodic table.    some information about each oxide is shown.    oxide solubility  in water ability to  neutralise  an acid ability to  neutralise  an alkali   x soluble \u001a \u0016 key  y insoluble \u0016 \u0016 \u0016= able  z slightly soluble \u0016 \u001a \u001a= not able    which types of oxides are x, y and z?      x y z  a acidic amphoteric basic  b amphoteric basic basic  c basic amphoteric acidic  d basic acidic amphoteric     ",
            "8": "8  \u00a9 ucles 2020 0620/22/f/m/20  19 four different acids are dissolved in water.    which beaker contains the most concentrated strong acid solution?    hx hx hxhx hx hx hx hxx\u2013 h+ h+h+ x\u2013z\u2013z\u2013 z\u2013z\u2013 z\u2013 z\u2013y\u2013 y\u2013 x\u2013c h+h+ h+ h+w\u2013 w\u2013w\u2013 w\u2013dhy hy hyhy hyhy h+ h+a h+ h+h+h+ h+h+b      20 the following substances can be reacted together to prepare salts.    1 copper( ii) oxide and excess hydrochloric acid  2 hydrochloric acid and excess sodium hydroxide  3 hydrochloric acid and excess zinc carbonate    in which reactions can the excess reactant be separated from the solution by filtration?  a 1 and 2 b 1 and 3 c 2 and 3 d 3 only    ",
            "9": "9     \u00a9 ucles 2020 0620/22/f/m/20 [turn over  21 salt s is dissolved in water and three tests are carried out on the solution.     test result  1     aqueous sodium  hydroxide is added   green precipitate formed,  insoluble in excess sodium  hydroxide  2 dilute nitric acid is added no reaction  3   aqueous barium nitrate is added  to the acidified solution from test 2 white precipitate formed      what is the identity of s?  a copper( ii) chloride  b copper( ii) sulfate  c iron( ii) chloride  d iron( ii) sulfate      22 which statement about the periodic table is correct?  a most metallic elements are on the left.  b elements in the same period have the same number of outer electrons.  c elements on the left are usually gases.  d the relative atomic mass of the elements increases from right to left.     23 the diagram shows elements w, x, y and z in a section of the periodic table.    x yzw     which statement about the reactivity of the elements is correct?  a x is more reactive than y, and w is more reactive than z.  b x is more reactive than y, and z is more reactive than w.  c y is more reactive than x, and w is more reactive than z.  d y is more reactive than x, and z is more reactive than w.    ",
            "10": "10  \u00a9 ucles 2020 0620/22/f/m/20  24 some properties of substances are listed.    1 they conduct electricity.  2 they have low densities.  3 they have high melting points.  4 they are malleable.    which properties are shown by transition metals?  a 1 and 3 only b 1 and 4 only c 1, 2 and 3 d 1, 3 and 4     25 sodium is a group i metal.    which property, that is typical of most metals, is not shown by sodium?  a conductor of heat  b high melting point  c malleable  d shiny      26 four metals, iron, copper, magnesium and y, are heated separately with their oxides.    the results are shown.    metal magnesium  oxide y  oxide copper  oxide iron  oxide   y \u001a \u001a \u0016 \u0016 key  magnesium \u001a \u0016 \u0016 \u0016 \u0016= reacts  copper \u001a \u001a \u001a \u001a \u001a= no reaction  iron \u001a \u001a \u001a \u001a     what is the order of reactivity of the metals, least reactive first?     least reactive  most reactive  a copper iron y magnesium  b copper y iron magnesium  c magnesium iron y copper  d magnesium y iron copper     ",
            "11": "11     \u00a9 ucles 2020 0620/22/f/m/20 [turn over  27 aluminium is extracted from bauxite by electrolysis.    which statement is correct?  a aluminium ions are oxidised to form aluminium.  b the cathode has to be replaced regularly becaus e it reacts with the oxygen which is formed.  c cryolite is added to remove impurities.  d carbon dioxide is produced at the anode.    28 some properties of aluminium are listed.    1 it conducts heat.  2 it has a low density. 3 it is strong. 4 it is resistant to corrosion.    which of these properties make aluminium suitable for making food containers for chilled food products?  a 1, 2 and 4 b 1, 3 and 4 c 1 only d 4 only     29 water is treated at a waterworks to make it fit to drink.    what is present in the water when it leaves the waterworks?  a bacteria only  b bacteria and insoluble substances  c chlorine compounds only  d chlorine compounds and soluble substances    30 sulfur dioxide, carbon monoxide and oxides of nitrogen are common gaseous pollutants found in  the air.    which pollutants contribute to acid rain?  a carbon monoxide and sulfur dioxide  b oxides of nitrogen and sulfur dioxide  c oxides of nitrogen only  d sulfur dioxide only     ",
            "12": "12  \u00a9 ucles 2020 0620/22/f/m/20  31 oxides of nitrogen, such as no and no 2, are formed in the petrol engines of cars.    they are removed from the exhaust gases by reactions in the car\u2019s catalytic converter.    which row describes how oxides of nitrogen are formed in a petrol engine, and a reaction that  happens in the catalytic converter?     how oxides of nitrogen are formed a reaction that happens  in the catalytic convertor  a   by the reaction between  nitrogen and oxygen from the air 2no  +  2co  \u2192  n2  +  2co 2    b   by the reaction between  nitrogen and oxygen from the air 2no  +  2h 2  \u2192  n2  +  2h 2o    c   by the reaction between nitrogen  compounds in petrol and oxygen from the air 2no  +  2co  \u2192  n2  +  2co 2    d   by the reaction between nitrogen  compounds in petrol and oxygen from the air 2no  +  2h 2  \u2192  n2  +  2h 2o       32 zinc is used to cover iron to prevent it from rusting.    why is zinc a suitable metal to use?  a iron is more reactive than zinc.  b iron atoms are bigger than zinc atoms.  c zinc is more reactive than iron.  d zinc atoms are bigger than iron atoms.    33 fertilisers are mixtures of different compounds used to increase the growth of crops.    which pair of substances contain the three essential elements for plant growth?  a ammonium nitrate and calcium phosphate  b ammonium nitrate and potassium chloride  c ammonium phosphate and potassium chloride  d potassium nitrate and calcium carbonate     ",
            "13": "13     \u00a9 ucles 2020 0620/22/f/m/20 [turn over  34 which row describes the conditions used in the manufacture of sulfuric acid by the contact  process?     catalyst pressure temperature  a iron high high  b iron low low  c vanadium( v) oxide high low  d vanadium( v) oxide low high     35 petroleum is an important raw material that is separated into useful products.    which terms describe petroleum and the method used to separate it?     description separation method  a compound cracking  b compound fractional distillation  c mixture cracking  d mixture fractional distillation     36 which statements about propene are correct?    1 propene contains only single bonds.  2 propene decolourises bromine water. 3 propene is obtained by cracking. 4 propene is a hydrocarbon.    a 1 and 4 b 2, 3 and 4 c 2 and 4 only d 4 only     37 which row describes the production of ethanol and its properties?     can be made  from glucose can be made  from ethene is used as a  fuel is used as a  solvent   a \u0016 \u0016 \u0016 \u0016 key  b \u0016 \u001a \u0016 \u0016 \u0016= yes  c \u001a \u0016 \u0016 \u001a \u001a= no  d \u001a \u0016 \u001a \u0016      ",
            "14": "14  \u00a9 ucles 2020 0620/22/f/m/20  38 ethanoic acid is a typical carboxylic acid.    which statement about ethanoic acid is correct?  a it can be oxidised to produce ethanol.  b it is a proton acceptor.  c it is fully dissociated in water.  d it reacts with ethanol to produce ethyl ethanoate and water.    39 which structure represents the ester made from ethanoic acid and propanol?    ho c h hh hch c hhc hh c oa ho c h hh c hhc hhc hhch hc ob ho c h hh c hhc hh coch c h hh c hhc ho chc hh o d      40 the structure of a polymer is shown.    co oc n hh n co h n     which statements about the polymer are correct?    1 the polymer is nylon.  2 the polymer is formed by condensation polymerisation. 3 there are ester linkages between the monomers.    a 1 and 2 b 2 and 3 c 2 only d 3 only    ",
            "15": "15    blank page     permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.   cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2020 0620/22/f/m/20  ",
            "16": "16  \u00a9 ucles 2020 0620/22/f/m/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m20_qp_32.pdf": {
            "1": "*4750882735* chemistry  0620/32 paper 3 theory (core) february/march 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 03_0620_32/3rp \u00a9 ucles 2020 [turn overthis document has 20 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/32/f/m/20 \u00a9 ucles 2020 1 (a)  a list of compounds is shown. aluminium oxide calcium bromide calcium oxide ethane ethene hydrogen chloride methane nitrogen dioxide potassium iodide potassium manganate( vii) sodium chloride   answer the following questions using only the compounds in the list.   each compound may be used once, more than once or not at all.   which compound:  (i)\t\twhen\tin\tacidified\tsolution,\tis\tused\tto\ttest\tfor\tsulfur\tdioxide   ...   [1]  (ii)  is the main constituent of natural gas   ...   [1]  (iii)\t\twhen\tdissolved\t in\twater,\tgives\ta\tyellow\tprecipitate\t on\taddition\t of\tacidified\t aqueous\t silver nitrate   ...   [1]  (iv)\t\tis\tused\tin\tflue\tgas\tdesulfurisation\tto\tneutralise\tacidic\tgases   ...   [1]  (v)  is a reactant used in the manufacture of ethanol?   ...   [1]  (b)  what is the meaning of the term compound  ?      ..   [2]",
            "3": "3 0620/32/f/m/20 \u00a9 ucles 2020 [turn over  (c)  complete the electronic structure of a molecule of hydrogen chloride.   show only the outer shell electrons. cl h  [2]  [total: 9]",
            "4": "4 0620/32/f/m/20 \u00a9 ucles 2020 2\t\tiron\tis\textracted\t by\theating\ta\tmixture\tof\tcoke\t(carbon),\t limestone\t and\tiron\tore\tin\tair\tin\ta\tblast\t furnace.   a diagram of the blast furnace is shown. coke (carbon) + limestone + iron ore air in molten ironslagfirebrick lining  (a)  name the ore of iron added to the blast furnace.   ..   [1]  (b)  the impurities in the iron ore are removed as slag.  (i)  what information in the diagram shows that slag is less dense than molten iron?   ...   [1]  (ii)  which one of the substances added to the blast furnace helps to remove the impurities? \t \texplain\thow\tit\tdoes\tthis.  substance  ... \t explanation\t  .   .   .  [3]  (c)  hot air is blown into the blast furnace. \t \texplain\twhy.      ..   [1]",
            "5": "5 0620/32/f/m/20 \u00a9 ucles 2020 [turn over  (d)  the chemical equation for one of the reactions in the blast furnace is shown. fe2o3  +  3co  \u2192  2fe  +  3co2  (i)  how does this equation show that fe2o3 has been reduced?   ...   [1]  (ii)  when 16.0 g of fe2o3\treact\twith\texcess\tcarbon\tmonoxide,\t11.2\t g\tof\tiron\tare\tproduced.   calculate the mass of iron produced when 4.0 g of fe2o3\treact\twith\texcess\tcarbon\tmonoxide.  mass of iron = .. g  [1]  (e)  an isotope of iron is shown. 58fe26   deduce the number of electrons, protons and neutrons in an atom of this isotope of iron.  number of electrons  ...  number of protons  .  number of neutrons  ...  [3]  (f)  iron is a transition element.   which two of these statements about iron are correct? \t \ttick\ttwo\tboxes.  iron forms coloured compounds.  iron can act as a catalyst.  iron is brown when freshly cut.  iron has a low density.  iron has a low melting point.  [2]  [total: 13]",
            "6": "6 0620/32/f/m/20 \u00a9 ucles 2020 3  water is essential for many industrial processes.  (a)  state one use of water in industry.    ..   [1]  (b)  what is the ph of pure water?   draw a circle around the correct answer.  ph 0               ph 6               ph 7               ph 14  [1]  (c)  filtration and chlorination are two of the steps used in water treatment.   describe the purpose of each of these steps. \t filtration\t ..     chlorination       [2]  (d)  the changes of state of water are shown. water ice steama freezing bboiling   give the names of the changes of state represented by a and b.  a    b    [2]",
            "7": "7 0620/32/f/m/20 \u00a9 ucles 2020 [turn over  (e)  the table compares the reactions of four metals with both steam and dilute hydrochloric acid. metalreaction with steam at 200 \u00b0cobservation with dilute hydrochloric acid copper no reaction no bubbles formed magnesium rapid reaction bubbles form rapidly nickel no reaction bubbles form slowly zinc rapid reaction bubbles form slowly   put the four metals in order of their reactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]  [total: 8]",
            "8": "8 0620/32/f/m/20 \u00a9 ucles 2020 4\t\tangelic\tacid\tand\tethanoic\tacid\tare\tboth\tcarboxylic\tacids.   the structure of angelic acid is shown. cc c co c hh oh hhhhh  (a) (i)  on the structure of angelic acid, draw a circle around the functional group that shows that  it\tis\ta\tcarboxylic\tacid.\t [1]  (ii)\t\tdeduce\tthe\tformula\tof\tangelic\tacid\tto\tshow\tthe\tnumber\tof\tcarbon,\thydrogen\t and\toxygen\t atoms.   ...   [1]  (iii)  angelic acid is an unsaturated compound.   describe a chemical test to distinguish between an unsaturated and a saturated compound.  test  ..  result with unsaturated compound  ..  result with saturated compound  ..  [3]  (b)  the formula of ethanoic acid is c2h4o2.   complete the table to calculate the relative molecular mass of ethanoic acid.   use the periodic table to help you. type of atomnumber of atomsrelative atomic mass carbon 2 12 2 \u00d7 12 = 24 hydrogen oxygen 16  relative molecular mass = ..  [2]",
            "9": "9 0620/32/f/m/20 \u00a9 ucles 2020 [turn over  (c)  ethanoic acid can be reduced to ethanol.   complete the structure of ethanol to show all of the atoms and all of the bonds. hch hc  [1]  (d)  ethanol can be manufactured by fermentation.   describe the process of fermentation to include:  \u25cf the names of the reactants and catalyst        \u25cf the conditions required           \u25cf\tthe\tname\tof\tthe\tprocess\tused\tto\tseparate\t the\tethanol\tfrom\tthe\trest\tof\tthe\treaction\t mixture.     [4]  [total: 12]",
            "10": "10 0620/32/f/m/20 \u00a9 ucles 2020 5  the table shows some properties of four metals in group i of the periodic table. metalmelting point / \u00b0cboiling point / \u00b0crelative electrical conductivity sodium 98 883 potassium 63 760 14 rubidium686 8 caesium 29 669 5  (a)  complete the table to estimate:  \u25cf the melting point of rubidium  \u25cf the relative electrical conductivity of sodium.  [2]  (b) what is the physical state of caesium at 20 \u00b0c?   give a reason for your answer.         ..   [2]  (c)  describe the trend in the boiling points of the group  i metals.   ..   [1]  (d)\t\twhen\tpotassium\t reacts\twith\twater,\ta\tcoloured\t flame\tis\tseen\tand\ta\tgas\tis\tproduced\t that\tpops\t with a lighted splint.  (i)  complete the chemical equation for this reaction.  ..k  +  2h2o  \u2192  2koh  +  . [2]  (ii)\t\tstate\tthe\tcolour\tof\tthe\tflame\twhen\tpotassium\treacts\twith\twater.   ...   [1]  (iii)\t\tthe\tsolution\tformed\tis\talkaline.   describe how you can use universal indicator solution to determine the ph of the solution.   .   ...   [2]  [to tal: 10]",
            "11": "11 0620/32/f/m/20 \u00a9 ucles 2020 [turn over 6 this question is about the reactions of magnesium with nitric acid.  (a)  the equation for the reaction of magnesium with concentrated nitric acid is shown. mg  +  4hno3  \u2192\t\tmg(no3)2  +  2no2  +  2h2o  (i)\t\tthe\treaction\tis\texothermic.   what is the meaning of the term exothermic?   ...   [1]  (ii)\t\twhich\tword \tbest\tdescribes\tthe\tcompound\tmg(no3)2?   draw a circle around the correct answer.  acid          base          oxide          salt  [1]  (iii)\t\toxides\tof\tnitrogen\tare\tformed\twhen\tfossil\tfuels\tare\tburned.   what type of chemical reaction occurs when fossil fuels are burned?   draw a circle around the correct answer.  combustion          cracking          fermentation          neutralisation  [1]  (iv)\t\toxides\tof\tnitrogen\tdissolve\tin\train\twater \tto\tform\tacid\train.   state one adverse effect of acid rain on buildings.   ...   [1]  (b)  when very dilute nitric acid reacts with magnesium powder, hydrogen is produced.  (i)  describe a practical method for investigating the rate of this reaction.   .   .   .   ...   [3]",
            "12": "12 0620/32/f/m/20 \u00a9 ucles 2020  (ii)  what effect would each of the following have on the rate of this reaction?  \u25cf larger pieces of magnesium are used instead of magnesium powder.   all other conditions stay the same.   .  \u25cf\tthe\ttemperature\tof\tthe\treaction\tmixture\tis\tincreased.   all other conditions stay the same.   .  [2]  [total: 9]",
            "13": "13 0620/32/f/m/20 \u00a9 ucles 2020 [turn over 7 (a)  the electrolysis of dilute sulfuric acid produces gases at both electrodes.  (i)  the incomplete apparatus is shown. electrolyt e power supply+ \u2013   complete the diagram by:  \u25cf labelling the anode and cathode  \u25cf adding connecting wires  \u25cf showing how the gases are collected.  [3]  (ii)  name the products formed at each electrode.  positive electrode    negative electrode  ..  [2]  (b)\t\tcarbon\tdioxide\tis\tproduced\twhen\tsulfuric\tacid\treacts\twith\tsodium\tcarbonate.   name the two other products which are formed.  .. and  ..  [2]  (c)\t\tdescribe\tthe\ttest\tfor\tcarbon\tdioxide.  test  .  observations  ..  [2]",
            "14": "14 0620/32/f/m/20 \u00a9 ucles 2020  (d)\t\tcarbon\tdioxide\tis\ta\tgreenhouse\tgas.   state one effect of greenhouse gases on the environment.   ..   [1]  [t otal: 10]",
            "15": "15 0620/32/f/m/20 \u00a9 ucles 2020 [turn over 8 (a)  the structures of four substances c, d, e and f, are shown. cl \u2013na+cl \u2013na+ cl \u2013na+cl \u2013na+na+cl \u2013na+cl \u2013na+cl \u2013na+cl \u2013cd ef ch h hhch h hhc chh hh hh hhc hh hh  (i)  which one of these substances, c, d, e or f, is a gas at room temperature?   ...   [1]  (ii)  what type of bonding is present in substance e?   ...   [1]  (iii)  which one of these substances, c, d, e or f, is soluble in water?   ...   [1]  (iv)  which one of these substances, c, d, e or f, conducts electricity when solid?   ...   [1]  (b)  the halogens have molecules containing two atoms.   what is the name for molecules containing only two atoms?   ..   [1]",
            "16": "16 0620/32/f/m/20 \u00a9 ucles 2020  (c)  the reaction of iodine with hydrogen is shown. i2  +  h2    2hi   what is the meaning of the symbol ?   ..   [1]  (d)  iodine is formed when chlorine reacts with aqueous potassium iodide.  (i)  complete the chemical equation for this reaction.  ..  +  2k i  \u2192  i2  +  ...kc l [2]  (ii)\t\twhen\taqueous\tiodine\tis\tmixed\twith\taqueous\tpotassium\tchloride,\tthere\tis\tno\treaction.   suggest, in terms of chemical reactivity, why there is no reaction.   ...   [1]  [total: 9]",
            "17": "17 0620/32/f/m/20 \u00a9 ucles 2020blank page",
            "18": "18 0620/32/f/m/20 \u00a9 ucles 2020blank page",
            "19": "19 0620/32/f/m/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/32/f/m/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_m20_qp_42.pdf": {
            "1": "*1792185691* chemistry  0620/42 paper 4 theory (extended) february/march 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 03_0620_42/2rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/42/f/m/20 \u00a9 ucles 2020 1  petroleum is a useful natural resource.   the diagram shows how petroleum can be separated into useful substances. kerosene fractionagasoline fractionrefinery gas diesel oil fuel oil fraction petroleumlubricating oil fraction b  (a)  what is the name of the separation process shown in the diagram?   ..   [2]  (b)  name the fraction leaving at:  a    b    [2]  (c)\t\trefinery\tgas\tis\ta\tmixture\tof\thydrocarbons. \t \tone\trefinery\tgas\tis\tbutane,\tc4h10.  (i)  suggest the names of two\tother\trefinery\tgases.  ...  and   ..   [2]  (ii)  write the chemical equation for the complete combustion of butane.   ...   [2]  (iii)\t\tname\tthe\ttoxic\tgas\tproduced\tby\tthe\tincomplete\tcombustion\tof\tbutane.   ...   [1]",
            "3": "3 0620/42/f/m/20 \u00a9 ucles 2020 [turn over  (d)\t\tgasoline\tand\tkerosene\tare\tboth\tfuels.\t they\thave\tdifferent\tproperties.  (i)  describe the differences in the properties given. \t viscosity\tof\tthe\tfuel\t .   . \t flammability\tof\tthe\tfuel\t     .  [2]  (ii)  what difference in the molecules of gasoline and kerosene causes these differences in  properties?   ...   [1]  (e)\t\thydrogen\tfuel\tcells\tcan\tbe\tused\tto\tpower\tvehicles. \t \twrite\tthe\tword\tequation\tfor\tthe\toverall\treaction\tthat\ttakes\tplace\tin\ta\thydrogen\tfuel\tcell.   ..   [1]  [total: 13]",
            "4": "4 0620/42/f/m/20 \u00a9 ucles 2020 2\t\taluminium\t is\textracted\t from\tits\tore.\tthe\tore\tis\tconverted\t into\tpure\taluminium\t oxide,\twhich\tthen\t undergoes\telectrolysis\tas\tshown. +++\u2013 anode spowe r suppl y electrolyte molten aluminiumwires cathode  (a) (i)  name an ore of aluminium.   ...   [1]  (ii)\t\twhat\tis\tmeant\tby\tthe\tterm\telectrolysis ?   .   ...   [2]  (b)\t\taluminium\t oxide\thas\ta\tmelting\tpoint\tof\tabout\t2000\t\u00b0c,\tbut\tthe\telectrolysis\t process\t operates\t at\t about 900 \u00b0c.  (i)\t\tname\tthe\tcompound\tadded\tto\taluminium \toxide\tto\treduce\tthe\toperating\ttemperature.   ...   [1]  (ii)  suggest one\tbenefit\tto\tthe\tenvironment \tof\treducing\tthe\toperating\t temperature.   .   ...   [1]  (iii)  write the ionic half-equation for the reaction taking place at:   the negative electrode (cathode)     the positive electrode (anode)    [4]  (iv)\t\texplain\twhy\tthe\tanodes\tneed\tfrequent\treplacement.   .     [2]",
            "5": "5 0620/42/f/m/20 \u00a9 ucles 2020 [turn over  (c)\t\taluminium\toxide\treacts\twith\tacids\tand\twith\talkalis.  (i)\t\twhat\tterm\tis\tused\tto\tdescribe\tan\toxide\t that\treacts\twith\tacids\tand\twith\talkalis?   ...   [1]  (ii)\t\taluminium\t oxide\treacts\twith\tdilute\tsulfuric\tacid\tto\tform\ta\tsalt.   state the name and write the formula of the salt formed.  name  ...  formula    [2]  (iii)\t\taluminium\t oxide\treacts\twith\tdilute\tsodium\thydroxide\t to\tform\ta\tsalt\tand\tone\tother\tproduct.   name the other product.   ...   [1]  (iv)\t\taluminium\t hydroxide,\t al (oh)3,\tdecomposes\t when\theated\tto\tform\taluminium\t oxide\tand\t water.   write the chemical equation for this reaction.   ...   [2]  (v)  suggest the names of two other aluminium compounds that decompose when heated to  form\taluminium\toxide.   .   ...   [2]  [total: 19]",
            "6": "6 0620/42/f/m/20 \u00a9 ucles 2020 3\t\tthe\tperiodic\t table\tis\ta\tmethod\tof\tclassifying\telements.  (a)\t\tidentify\tthe\telement\twhich\tis\tin\tgroup\tvi\tand\tperiod \t4.   ..   [1]  (b)\t\tcalcium\tis\tin\tgroup\tii\tand\tchlorine\tis\tin\tgroup\tvii\tof\tthe\tperiodic\t table. \t \texplain,\t in\tterms\tof\tnumber\tof\touter\tshell\telectrons\t and\telectron\t transfer,\t how\tcalcium\tatoms\t and chlorine atoms form ions. give the formulae of the ions formed.                     ..   [5]  (c)\t\tgroup\tv\tchlorides\t are\tcovalent\t molecules.\t the\tboiling\tpoints\tof\tsome\tgroup\tv\tchlorides\t are\t shown. chloride boiling point / \u00b0c ncl 3 71 pcl 3 ascl 3 130 sbcl 3 283  (i)\t\tsuggest\tthe\tapproximate\tboiling\tpoint\tof\tpcl 3.   ...   [1]  (ii)\t\texplain\tthe \ttrend\tin\tboiling\tpoints\tin\tterms\tof\tattractive\tforces\tbetween\tparticles.   .   ...   [2]",
            "7": "7 0620/42/f/m/20 \u00a9 ucles 2020 [turn over  (iii)\t\tcomplete\t the\tdot-and-cross\t diagram\t to\tshow\tthe\telectron\t arrangement\t in\ta\tmolecule\t of\t pcl 3. \t \tshow\touter\telectrons\tonly. p clcl cl  [3]  (d)\t\tp c l 3\treacts\twith\tchlorine,\t cl 2,\tto\tform\tpcl 5.\tthis\treaction\t is\texothermic\t and\treaches\t an\t equilibrium. pcl 3(g)\t\t+\t\tcl 2(g)  \t\tpcl 5(g)  (i)  describe two features of an equilibrium.   .   .   ...   [2]  (ii)\t\tstate\tthe\teffect,\tif\tany,\ton\tthe\tposition\tof\tthis\tequilibrium\t when\tthe\tfollowing\t changes\t are\t made. \t \texplain\tyour\tanswers.  temperature is increased     .  pressure is increased  .   .  [4]  (iii)\t\texplain,\t in\tterms\tof\tparticles,\t what\thappens\t to\tthe\trate\tof\tthe\tforward\treaction\t when\tthe\t reaction\tmixture\tis\theated.   .   .   .   .   ...   [3]",
            "8": "8 0620/42/f/m/20 \u00a9 ucles 2020  (e)\t\tp c l 5\treacts\twith\tlithium\tfluoride,\tlif,\tto\tform\tlipf6. pcl 5\t\t+\t\t6lif\t\t \u2192\t\tlipf6\t\t+\t\t5licl \t \tcalculate\tthe\tmass\tof\tlif\tneeded\tto\tform\t3.04\t g\tof\tlipf6 using the following steps.  \u25cf\tcalculate\tthe\tnumber\tof\tmoles\tof\tlipf6 formed.   [mr:\t\tlipf6,\t152]  number of moles = ..  \u25cf\tdeduce\tthe\tnumber\tof\tmoles\tof\tlif\tneeded.  number of moles = ..  \u25cf\tcalculate\tthe\tmass\tof\tlif\tneeded.  mass = .. g  [3]  (f)\t\tlithium\tfluoride\thas\tionic\tbonding.  (i)  what is an ionic bond?   .   ...   [2]  (ii)  give two\tphysical\tproperties\tof\tionic\tcompounds.   .   ...   [2]  [total: 28]",
            "9": "9 0620/42/f/m/20 \u00a9 ucles 2020 [turn over 4\t\tiron\tis\ta\ttypical\ttransition\telement.   iron:  \u25cf\tacts\tas\ta\tcatalyst  \u25cf forms coloured compounds   \u25cf\thas\tmore\tthan\tone\toxidation\tstate.  (a)  name one\tmajor\tindustrial\t process\t that\tuses\tiron\tas\ta\tcatalyst\tand\tname\tthe\tproduct\tmade\tin\t this process.  process  ..  product made  .  [2]  (b)\t\twhen\taqueous\tsodium\thydroxide\tis\tadded\tto\taqueous\tiron( ii)\tsulfate,\ta\tprecipitate\tforms.  (i)  what colour is this precipitate?   ...   [1]  (ii)\t\twrite\tthe\tionic\tequation\tfor\tthis\treaction.\tinclude\tstate\tsymbols.   ...   [3]  (c)  iron( ii) sulfate can be converted to iron( iii)\tsulfate\tby\tpotassium\t manganate( vii) at room  temperature.  (i)  what is the role of potassium manganate( vii) in this reaction?   ...   [1]  (ii)  what condition must be used for this reaction to occur?   ...   [1]  (iii)\t\tin\tterms\tof\t electron\ttransfer,\twhat\thappens\tto\tthe\tiron( ii) ions in this reaction?   ...   [1]  (iv)  state the colour change seen during this reaction.  from purple to  ...   [1]  (d)  deduce the charge on the iron ion in each of these compounds. \t \tfef3  ... \t \tfe(no3)3    [2]  [total: 12]",
            "10": "10 0620/42/f/m/20 \u00a9 ucles 2020 5\t\tthere\tare\ttwo\ttypes\tof\tpolymers.  (a)\t\taddition\tpolymers\tare\tmade\tfrom\tmany\tidentical\tsmall\tunits.  (i)  what is the term used to describe these small units?   ...   [1]  (ii)\t\ta\tsection\tof\tan\taddition\tpolymer\tis\tshown. ch hcch3 ch3ch hcch3 ch3ch hcch3 ch3 \t \tdraw\tthe\tstructure\tof\tthe\tsmall\tunit\tused \tto\tmake\tthis\taddition\tpolymer.   show all of the atoms and all of the bonds.  [2]  (b)\t\tpolyamides\tare\tcondensation\tpolymers.   what does the term condensation \tmean\twhen\tused\tto\tdescribe\tthis\ttype\tof\tpolymer?   ..   [1]",
            "11": "11 0620/42/f/m/20 \u00a9 ucles 2020permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (c)\t\ta\tpolyamide\tcan\tbe\tmade\tfrom\ttwo\tdifferent\tmolecules. \t \ta\tsimplified\tstructure\tof\toctanedioic\tacid\tis\tshown. c co o o oh h \t \ta\tsimplified\tstructure\tof\t1,6-diaminohexane\tis\tshown. n nh h h h  (i)\t\tcomplete\t the\tdiagram\t to\tshow\ta\tsection\tof\tpolyamide\t manufactured\t from\toctanedioic\t acid\t and\t1,6-diaminohexane.\tinclude\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds\tin\tthe\tlinkages.  [3]  (ii)\t\tstate\tthe\tname\tof\ta\tsynthetic\tpolyamide.   ...   [1]  [total: 8]",
            "12": "12 0620/42/f/m/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_m20_qp_52.pdf": {
            "1": "*8608814193* chemistry  0620/52 paper 5 practical test february/march 2020  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib20 03_0620_52/3rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/52/f/m/20 \u00a9 ucles 2020blank page",
            "3": "3 0620/52/f/m/20 \u00a9 ucles 2020 [turn over 1  you are going to investigate the time taken to collect 40 cm3 of hydrogen gas when magnesium  reacts with dilute sulfuric acid.   read all of the instructions carefully before starting the experiments.   instructions \t\tyou\tare\tgoing\tto\tdo\tfive\texperiments\tusing\tthe\tapparatus\tshown. waterinverted 50  cm3 measuring cylinder dilute sulfuric acid and distilled water  experiment 1  \u25cf use the 10 cm3\tmeasuring\tcylinder\tto\tpour\t8\t cm3 of dilute sulfuric acid into the boiling tube.  \u25cfuse the 25 cm3\tmeasuring\tcylinder\tto\tpour\t12\t cm3 of distilled water into the boiling tube.  \u25cf\tset\tup\tthe\tapparatus\t as\tshown\tin\tthe\tdiagram,\tensuring\tthe\tinverted\tmeasuring\t cylinder\tis\tfull\t of water.   \u25cf remove the bung from the boiling tube.  \u25cf\tadd\ta\tcoiled\tlength\tof\tmagnesium\t ribbon\tto\tthe\tboiling\ttube,\timmediately\t replace\tthe\tbung\tand\t start the timer.  \u25cf measure the time taken for 40 cm3 of gas to be collected. record the time to the nearest  second in the table in (b).  \u25cf feel the outside of the boiling tube.  (a) (i)\t\twhat\thappens\tto\tthe\ttemperature\tof\tthe\tcontents\tof\tthe\tboiling\ttube\tduring\tthe\treaction?   ...   [1]  (ii)  what does your answer to (a)(i)\ttell\tyou\tabout\tthe\ttype\tof\treaction?   ...   [1]  (iii)  describe one\tchange\tthat\tcould\tbe\tmade\tto\tthe\tapparatus\t to\thelp\tkeep\tthe\ttemperature\t of the contents of the boiling tube constant during the reaction.   ...   [1]",
            "4": "4 0620/52/f/m/20 \u00a9 ucles 2020  experiment 2  \u25cf rinse out the boiling tube with distilled water.  \u25cf\tuse\ta\tmeasuring\t cylinder\tto\tpour\t10\tcm3 of dilute sulfuric acid and 10 cm3 of distilled water into  the boiling tube.  \u25cf\tset\tup\tthe\tapparatus\t as\tshown\tin\tthe\tdiagram,\tensuring\tthe\tinverted\tmeasuring\t cylinder\tis\tfull\t of water.   \u25cf remove the bung from the boiling tube.  \u25cf\tadd\ta\tcoiled\tlength\tof\tmagnesium\t ribbon\tto\tthe\tboiling\ttube,\timmediately\t replace\tthe\tbung\tand\t start the timer.  \u25cf measure the time taken for 40 cm3 of gas to be collected. record the time to the nearest  second in the table in (b).   experiment 3  \u25cf\trepeat\texperiment\t 2\tusing\tthe\t25\tcm3\tmeasuring\t cylinder\tto\tpour\t12\tcm3 of dilute sulfuric acid  into the boiling tube. use the 10 cm3\tmeasuring\t cylinder\tto\tpour\t8\tcm3 of distilled water into the  boiling tube.   experiment 4  \u25cf\trepeat\texperiment\t3\tusing\t16\t cm3 of dilute sulfuric acid and 4 cm3 of distilled water.   experiment 5  \u25cf\trepeat\texperiment\t3\tusing\t20\t cm3 of dilute sulfuric acid and no distilled water.  (b)\t\tcomplete\tthe\ttable. experimentvolume of dilute sulfuric acid / cm3volume of distilled water / cm3time to collect 40 cm3 of gas / s 1 8 2 10 3 12 4 16 5 20  [4]",
            "5": "5 0620/52/f/m/20 \u00a9 ucles 2020 [turn over  (c)  add a suitable scale to the y-axis\t and\tplot\tyour\tresults\tfrom\texperiments\t 1\tto\t5\ton\tthe\tgrid.\t draw\ta\tsmooth\tline\tgraph. 68 10 12 14 volume of dilute sulfuric acid  / cm3time to collect 40 cm3 of gas  / s 16 18 20  [4]  (d) (i)  from your graph,\t deduce\tthe\ttime\ttaken\tto\tcollect\t40\tcm3\tof\tgas\tif\tthe\texperiment\t was\t repeated\tusing\t9\t cm3 of dilute sulfuric acid.   show clearly on the grid  how you worked out your answer.  ..  s  [2]  (ii)\t\twhat\tvolume\tof\tdistilled\twater\twould\tbe\tneeded\tif\tthe\texperiment\t was\trepeated\t   using\t9\tcm3\tof\tdilute\tsulfuric\tacid?  .. cm3  [1]",
            "6": "6 0620/52/f/m/20 \u00a9 ucles 2020  (e)  the rate of reaction can be calculated using the equation shown. rate of reaction =volume of gas collected time taken to collect the gas  (i)\t\tuse\tthis\tequation\tto\tcalculate\tthe\trate\tof\treaction\tin\texperiment\t 1.\tgive\tthe\tunits\tfor\tthe\t rate of reaction you have calculated.  rate of reaction = .. units = ..  [2]  (ii)\t\tin\twhich\texperiment,\t1,\t2,\t3,\t4\tor\t5,\twas\tthe\trate\tof\treaction\tgreatest?   ...   [1]  (f)  why would measuring the volume of dilute sulfuric acid with a burette rather than a measuring  cylinder\tbe\tan\timprovement?      ..   [1]  (g)  the magnesium starts to react with the dilute sulfuric acid as soon as it is added.  (i)\t\twhy\tdoes\tthis\tdecrease\tthe\taccuracy\tof \tthe\tinvestigation?   .   ...   [1]  (ii)  describe one\timprovement\tthat\tcould\tbe\tmade\tto\tovercome\tthis\tproblem.   .   .   ...   [1]  (h)  sketch on the grid in (c)\t the\tgraph\tyou\twould\texpect\tif\tall\tof\tthe\texperiments \twere\trepeated\t at a higher\ttemperature.\tclearly\tlabel\tyour\tgraph.\t [1]  [total: 21]",
            "7": "7 0620/52/f/m/20 \u00a9 ucles 2020 [turn over 2\t\tyou\tare\tprovided\twith\ttwo\tsubstances,\tsolution\t j and solid k.   do the following tests on solution j and solid k,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.   tests on solution j   divide solution j\tinto\tfour\tapproximately\t equal\tportions\tin\tfour\ttest-tubes.\t you\twill\tneed\tto\tkeep\tone\t portion\tfor\tthe\ttests\ton\tsolid\tk.  (a)\t\tdescribe\tthe\tappearance\tof\tsolution\t j.   ..   [1]  (b)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tj. \t ph\t=\t..\t\t[1]  (c)\t\tadd\ta\tspatula\tmeasure\tof\tsodium\tcarbonate\tto\tthe\t second\tportion\tof\tsolution\t j. \t\ttest\tthe\tgas\tproduced.   record your observations.         ..   [3]  (d)  add about 1 cm3\tof\tdilute\tnitric\tacid\tand\ta\tfew\tdrops\tof\taqueous\tsilver\tnitrate\tto\tthe\tthird\tportion\t of solution j.   record your observations.      ..   [1]  (e)  identify solution j.      ..   [2]",
            "8": "8 0620/52/f/m/20 \u00a9 ucles 2020  tests on solid k  (f)\t\tusing\ta\tspatula,\tplace\tapproximately\t half\tof\tsolid\t k\tin\ta\ttest-tube.\t add\tthe\tfourth\tportion\tof\t solution j\tto\tthis\tportion\tof\tsolid\t k.\tstopper\tthe\ttest-tube\tand\tshake\tthe\tcontents.\t carefully\t smell\tthe\tproduct.   record your observations.   ..   [1]  (g)  add the remaining solid k to about 10 cm3\tof\tdistilled\twater\tin\ta\tboiling\ttube.\tstopper\tthe\tboiling\t tube and shake it to dissolve solid k and form solution k.  (i)  add 2 cm3\tof\taqueous\tsodium\thydroxide \tto\tsolution\tk.   record your observations.   ...   [1]  (ii)\t\twarm\tthe\tmixture\tformed\tin\t(g)(i)\tgently.\t test\tany\tgas\tproduced.   record your observations.   .   ...   [2]  (h) identify one ion in solid k.   ..   [1]  [total: 13]",
            "9": "9 0620/52/f/m/20 \u00a9 ucles 2020 [turn over 3\t\ta\tblack\tdye\tcan\tbe\tobtained\tfrom\tsome\tplant\troots.   plan an investigation to determine how many different coloured substances are contained in a  black\tdye\tobtained\tfrom\tplant\troots.   you must include how the results you obtain will tell you how many different coloured substances  are contained in the black dye. \t\tyou\thave\taccess\tto\tplant\troots\tand\tall\tnormal\tlaboratory\tapparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6]",
            "10": "10 0620/52/f/m/20 \u00a9 ucles 2020blank page",
            "11": "11 0620/52/f/m/20 \u00a9 ucles 2020notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/52/f/m/20 \u00a9 ucles 2020tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_m20_qp_62.pdf": {
            "1": "*6193842897* chemistry  0620/62 paper 6 alternative to practical february/march 2020  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib20 03_0620_62/2rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/62/f/m/20 \u00a9 ucles 2020 1  the table gives the boiling points of four alcohols. alcohol boiling point / \u00b0c methanol 65 ethanol 79 propan-1-ol 97 butan-1-ol 117   the apparatus shown can be used to separate a mixture of the four alcohols shown in the table. heatba condenser mixture of alcoholsalcohol collecte d  (a)  name the apparatus labelled a and b.  a    b    [2]  (b)  add to the diagram one arrow to show where water enters the condenser. [1]  (c) (i)  why is it not safe to heat the mixture of alcohols with a bunsen burner?   ...   [1]  (ii)  suggest how the mixture of alcohols can be heated safely?   ...   [1]",
            "3": "3 0620/62/f/m/20 \u00a9 ucles 2020 [turn over  (d)  describe how the condenser allows the alcohol to be collected as a liquid.      ..   [1]  (e)\t\twhich\talcohol\twould\tbe\tcollected\tfirst?   explain your answer. \t alcohol\tcollected\tfirst\t  .  explanation       [2]  [total: 8]",
            "4": "4 0620/62/f/m/20 \u00a9 ucles 2020blank page",
            "5": "5 0620/62/f/m/20 \u00a9 ucles 2020 [turn over 2  a student investigated the time taken to collect 40 cm3 of hydrogen gas when magnesium reacts  with dilute sulfuric acid.   five experiments were done using the apparatus shown. waterinverted 50  cm3 measuring cylinder dilute sulfuric acid and distilled water   experiment 1  \u25cf using a measuring cylinder, 8 cm3 of dilute sulfuric acid was poured into the boiling tube.  \u25cf using a second measuring cylinder, 12 cm3 of distilled water was added to the acid in the  boiling tube.  \u25cf the apparatus was set up as shown in the diagram, ensuring the inverted measuring cylinder  was full of water.  \u25cf the bung was removed from the boiling tube.  \u25cf a coiled length of magnesium ribbon was added to the boiling tube, the bung was immediately  replaced and a timer started.  \u25cf the time taken for 40 cm3 of gas to be collected was measured.  \u25cf the student felt the outside of the boiling tube.  (a) (i)  the student noticed that the boiling tube was warm.   what does this tell you about the type of reaction?   ...   [1]  (ii)  describe one change that could be made to the apparatus to help keep the temperature  of the contents of the boiling tube constant during the reaction.   ...   [1]  experiment 2  \u25cf the boiling tube was rinsed out with distilled water.  \u25cf experiment 1 was repeated using 10 cm3 of dilute sulfuric acid and 10 cm3 of distilled water.   experiment 3  \u25cf experiment 2 was repeated using 12 cm3 of dilute sulfuric acid and 8 cm3 of distilled water.   experiment 4  \u25cf experiment 2 was repeated using 16 cm3 of dilute sulfuric acid and 4 cm3 of distilled water.   experiment 5  \u25cf experiment 2 was repeated using 20 cm3 of dilute sulfuric acid and no distilled water.",
            "6": "6 0620/62/f/m/20 \u00a9 ucles 2020  (b)  use the information in the description of the experiments and the timer diagrams to complete  the table. record the time in seconds. experimentvolume of dilute sulfuric acid / cm3volume of distilled water / cm3timer diagramtime to collect 40 cm3 of gas / s 1 80 0 10 3015 1545 5second s minutes 2 100 0 10 3015 1545 5 3 120 0 10 3015 1545 5 4 160 0 10 3015 1545 5 5 200 0 10 3015 1545 5  [4]",
            "7": "7 0620/62/f/m/20 \u00a9 ucles 2020 [turn over  (c)  add a suitable scale to the y-axis and plot the results from experiments 1 to 5 on the grid.   draw a smooth line graph. 68 10 12 14 volume of dilute sulfuric acid  / cm3time to collect 40 cm3 of gas  / s 16 18 20  [4]  (d) (i)  from your graph, deduce the time taken to collect 40 cm3 of gas if the experiment was  repeated using 9 cm3 of dilute sulfuric acid.   show clearly on the grid  how you worked out your answer.  .. s  [2]  (ii)  what volume of distilled water would be needed if the experiment was repeated   using 9 cm3 of dilute sulfuric acid?  .. cm3  [1]",
            "8": "8 0620/62/f/m/20 \u00a9 ucles 2020  (e)  the rate of reaction can be calculated using the equation shown. rate of reaction =volume of gas collected time taken to collect the gas  (i)  use this equation to calculate the rate of reaction in experiment 1. give the units for the  rate of reaction you have calculated.  rate of reaction = .. units = ..  [2]  (ii)  in which experiment, 1, 2, 3, 4 or 5, was the rate of reaction greatest?   ...   [1]  (f)  why would measuring the volume of dilute sulfuric acid with a burette rather than a measuring  cylinder be an improvement?      ..   [1]  (g)  the magnesium starts to react with the dilute sulfuric acid as soon as it is added.  (i)  why does this decrease the accuracy of the investigation?   ...   [1]  (ii)  describe one improvement that you could make to overcome this problem.   .   .   ...   [1]  [total: 19]",
            "9": "9 0620/62/f/m/20 \u00a9 ucles 2020 [turn over 3  solution j and solid k were analysed.   tests on solution j tests observations solution j was colourless. solution j was  divided into three portions in three test-tubes. test 1 universal indicator paper was dipped into the  first\tportion\tof\tsolution\tj.the universal indicator paper turned red test 2 a spatula measure of sodium carbonate was  added to the second portion of solution j. the  gas given off was tested.effervescence was seen, the gas produced  turned limewater milky test 3 1 cm3 of dilute nitric acid and a few drops of  aqueous silver nitrate were added to the third  portion of solution j.a white precipitate formed  (a)  use the observation from test 1 to suggest the ph of solution j.  ph = ..  [1]  (b)  name the gas given off in test 2.   ..   [1]  (c)  identify solution j.      ..   [2]",
            "10": "10 0620/62/f/m/20 \u00a9 ucles 2020  tests on solid k   solid k was ammonium nitrate.   complete the expected observations.   solid k was dissolved in water to produce solution k. solution k was divided into two equal portions.  (d)  about 1 cm3 of dilute nitric acid and a few drops of aqueous barium nitrate were added to the  first\tportion\tof\tsolution\tk.  observations     [1]  (e)  2 cm3 of aqueous sodium hydroxide was added to the second portion of solution k. the mixture  was warmed and the gas given off was tested.   observations  ..      ..   [2]  [total: 7]",
            "11": "11 0620/62/f/m/20 \u00a9 ucles 2020 [turn over 4  a black dye can be obtained from some plant roots.   plan an investigation to determine how many different coloured substances are contained in a  black dye obtained from plant roots.   you must include how the results you obtain will tell you how many different coloured substances  are contained in the black dye.   you have access to plant roots and all normal laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "12": "12 0620/62/f/m/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s20_qp_11.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 06_0620_11/4rp   \u00a9 ucles 2020   [turn ove r   *5245914244*cambridge igcse\u2122       chemistry  0620/11     paper 1 multiple choice (core)  may/june 2020     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate num ber on the multiple choice answer sheet in the  spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/11/m/j/20  1 nitrogen is heated in a balloon, which expands slightly.    which statements about the molecules of nitrogen are correct?    1 they move further apart.  2 they move more quickly. 3 they remain the same distance apart. 4 their speed remains unchanged.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4      2 which piece of apparatus should be used to measure exactly 21.4  cm3 of water?  a 25  cm3 beaker  b 25  cm3 pipette  c 50  cm3 burette  d 50  cm3 measuring cylinder      3 which method of separation is used to separate a soluble solid from its solution?  a chromatography  b condensation  c crystallisation  d filtration     4 the atomic number and nucleon number of a potassium atom are shown.     potassium atom  atomic number 19  nucleon number 39    how many protons, neutrons and electrons are in a potassium ion, k+?     protons neutrons electrons  a 19 20 18  b 19 20 20  c 20 19 18  d 20 19 19    ",
            "3": "3     \u00a9 ucles 2020 0620/11/m/j/20 [turn over  5 sodium is in group i of the periodic table.    chlorine is in group vii of the periodic table.    sodium and chlorine combine to form a compound.    which statement about the combination of sodium and chlorine atoms is correct?  a both sodium and chlorine lose electrons.  b both sodium and chlorine gain electrons.  c sodium loses electrons and chlorine gains electrons.  d sodium gains electrons and chlorine loses electrons.     6 the electronic structures of two atoms, p and q, are shown.    p q     p and q combine together to form a compound.    what is the type of bonding in the compound and what is the formula of the compound?     type of bonding formula  a ionic pq  b ionic pq 2  c covalent pq 2  d covalent pq     ",
            "4": "4  \u00a9 ucles 2020 0620/11/m/j/20  7 the structures of diamond and graphite are shown.        which statement about diamond and graphite is correct?  a diamond and graphite have low melting points.  b diamond and graphite have mobile electrons.  c diamond and graphite have layered structures.  d diamond and graphite contain strong covalent bonds between carbon atoms.      8 aluminium oxide has the formula a l 2o3.     which statement about aluminium oxide is correct?  a 2 g of aluminium atoms are combined with 3  g of oxygen atoms.  b 2 g of aluminium atoms are combined with 3  g of oxygen molecules.  c aluminium oxide has a relative formula mass of 102.  d pure aluminium oxide contains a higher mass of oxygen than of aluminium.     9 which products are formed when dilute sulfuric acid undergoes electrolysis?     at the anode at the cathode  a oxygen hydrogen  b hydrogen oxygen  c sulfur dioxide hydrogen  d oxygen sulfur dioxide     10 which element is not used as a fuel?  a carbon  b helium  c hydrogen  d uranium     ",
            "5": "5     \u00a9 ucles 2020 0620/11/m/j/20 [turn over  11 the energy level diagram shows the energy of the reactants and products in a chemical reaction.    reactants progress of reactionproductsenergy     which row correctly describes the energy change and the type of reaction shown?     description of  energy change type of reaction  a   energy is given out  to the surroundings endothermic    b   energy is given out  to the surroundings exothermic    c   energy is taken in from  the surroundings endothermic    d   energy is taken in from  the surroundings exothermic       12 which diagram represents a chemical change?    a b c d     ",
            "6": "6  \u00a9 ucles 2020 0620/11/m/j/20  13 the rate of reaction between magnesium and hydrochloric acid is investigated.    the volume of hydrogen given off at different times is measured.    the results are shown.    25 201510 5 0 0 1 02 03 04 05 06 07 08 09 0 1 0 0volume of hydrogen/  cm3 time  / s    which conclusions are correct?    1 the rate is fastest between 0 and 20 seconds.  2 the maximum volume of hydrogen given off is 22  cm3.  3 at 40 seconds, 20  cm3 of hydrogen is given off.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3      14 which reaction can be easily reversed?  a dissolving zinc in hydrochloric acid  b fermenting glucose with yeast  c heating hydrated cobalt( ii) chloride  d the rusting of an iron nail     15 carbon reacts with silver oxide to form carbon dioxide and silver.    which substance is reduced?  a carbon  b carbon dioxide  c silver  d silver oxide     ",
            "7": "7     \u00a9 ucles 2020 0620/11/m/j/20 [turn over  16 the graph shows how the ph of a solution changes as an acid is added to an alkali.    acid  +  alkali  \u2192  salt  +  water    which letter represents the area of the graph where both acid and salt are present?    pha b c d14 7 0 volume of acid added      17 phosphorus is an element in group v of the periodic table.    it burns in air to form an oxide, which dissolves in water to form a solution with a ph of 1.    which row describes this oxide of phosphorus?     metal  oxide non-metal  oxide acidic  oxide basic  oxide  a \u0016 \u001a \u0016 \u001a  b \u0016 \u001a \u001a \u0016  c \u001a \u0016 \u0016 \u001a  d \u001a \u0016 \u001a \u0016     ",
            "8": "8  \u00a9 ucles 2020 0620/11/m/j/20  18 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ysolid x aqueous copper( ii) sulfateexcess of solid xfilter paper heatstirrer     what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride dilute sulfuric acid  c copper( ii) oxide dilute sulfuric acid  d sulfur aqueous copper( ii) chloride      19 two tests are carried out on substance z.    test 1 a flame test produces a red flame.    test 2 z is dissolved in water and dilute nitric acid is added, followed by  aqueous silver nitrate. a yellow precipitate is produced.    what is substance z?  a lithium bromide  b lithium iodide  c sodium bromide  d sodium iodide     ",
            "9": "9     \u00a9 ucles 2020 0620/11/m/j/20 [turn over  20 the elements in period 3 of the periodic table are shown.    na mg al si p s cl ar    which statements about the elements in period 3 are correct?    1 na, mg and a l are metals.  2 s, c l and ar are non-metals.  3 si, p and s are metals.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    21 a group i metal (lithium, sodium or potassium) is reacted with a group vii element (chlorine,  bromine or iodine).    which compound is formed when the group i metal of highest density reacts with the group vii  element of lowest density?  a lithium chloride  b potassium chloride  c potassium iodide  d lithium iodide      22 the properties of the element titanium, ti, can be predicted from its position in the periodic table.    which row identifies the properties of titanium?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0016 \u0016 \u0016 \u001a  b \u0016 \u0016 \u001a \u0016  c \u0016 \u001a \u0016 \u0016  d \u001a \u0016 \u0016 \u0016     ",
            "10": "10  \u00a9 ucles 2020 0620/11/m/j/20  23 a balloon is filled with helium. helium is a noble gas and makes the balloon rise up in the air.    the density of air is 1.23  g / dm3.    which gas is helium?     density in g  / dm3 reaction with oxygen  a 0.0899 burns rapidly  b 0.179 does not react with oxygen  c 1.78 does not react with oxygen  d 3.75 does not react with oxygen      24 which property is shown by all metals?  a they are extracted from their ores by heating with carbon.  b they conduct electricity.  c they form acidic oxides.  d they react with hydrochloric acid to form hydrogen.    25 the properties of four metals, w, x, y and z, are shown.    w it does not react with cold water but reacts with steam.  x it does not react with water or dilute acid but the oxide of x is reduced by carbon. y the oxide of y is not reduced by carbon but y reacts vigorously with cold water. z it does not react with water or steam but reacts with dilute acid.    what is the order of reactivity of the elements starting with the most reactive?     most  reactive   least  reactive  a x w z y  b x z w y  c y w z x  d y z w x     ",
            "11": "11     \u00a9 ucles 2020 0620/11/m/j/20 [turn over  26 molten iron from the blast furnace contains impurities.    the process of turning the impure iron into steel involves blowing oxygen into the molten iron and  adding calcium oxide.    what are the reasons for blowing in oxygen and adding calcium oxide?     blowing in oxygen adding calcium oxide  a carbon is removed by reacting with oxygen reacts with acidic impurities making slag  b carbon is removed by reacting with oxyg en reacts with slag and so removes it  c iron reacts with the oxygen reacts with acidic impurities making slag  d iron reacts with the oxygen reacts with slag and so removes it      27 which row describes two uses of the named steel?     type of steel uses  a mild steel cutlery and car bodies  b mild steel car bodies and chemical plant  c stainless steel cutlery and chemical plant  d stainless steel car bodies and cutlery     28 which statement shows that a liquid is pure water?  a it boils at 100  \u00b0c.  b it has a ph value of 7.  c it turns blue cobalt( ii) chloride pink.  d it turns white copper( ii) sulfate blue.     29 some gases are present in clean air while other gases are only present in polluted air.    which row is correct?     a gas present  in clean air a gas only present  in polluted air  a argon carbon dioxide  b argon nitrogen dioxide  c sulfur dioxide carbon dioxide  d sulfur dioxide nitrogen dioxide     ",
            "12": "12  \u00a9 ucles 2020 0620/11/m/j/20  30 the diagrams show experiments to investigate rusting of iron nails.    3 boiled water2 salt water1 tap waterlayer of oil     in which test-tubes do the nails rust?  a 1 only b 1 and 2 only c 1 and 3 only d 1, 2 and 3      31 which mixture contains all of the elements in a typical fertiliser?  a ammonium nitrate and calcium phosphate  b ammonium phosphate and potassium chloride  c potassium nitrate and ammonium chloride  d potassium carbonate and ammonium nitrate      32 which processes produce methane?    1 complete combustion of carbon-containing compounds  2 decomposition of vegetation 3 digestion in animals  4 respiration in animals    a 1 and 4 b 1 and 3 c 2 and 3 d 2 and 4    ",
            "13": "13     \u00a9 ucles 2020 0620/11/m/j/20 [turn over  33 the list shows four methods that were suggested for the formation of carbon dioxide.    1 cracking methane using steam  2 action of heat on a carbonate  3 complete combustion of methane  4 reaction of a carbonate with oxygen    which methods would result in the production of carbon dioxide?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     34 a student suggests three uses of calcium carbonate (limestone).    1 manufacture of cement  2 manufacture of iron 3 treating alkaline soils    which suggestions are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     35 which list shows the fractions obtained from distilling petroleum, in order of increasing boiling  point?  a bitumen \u2192 diesel oil \u2192 fuel oil \u2192 lubricating oil  b diesel oil \u2192 gasoline \u2192 naphtha \u2192 kerosene  c gasoline \u2192 naphtha \u2192 kerosene \u2192 diesel oil  d kerosene \u2192 lubricating oil \u2192 naphtha \u2192 refinery gas      36 which statement about members of a homologous series is correct?  a they are elements with the same chemical properties.  b they are compounds with the same functional group.  c they are atoms with the same number of outer electrons.  d they are molecules with the same boiling point.     ",
            "14": "14  \u00a9 ucles 2020 0620/11/m/j/20  37 increasing the number of atoms in one molecule of a hydrocarbon increases the amount of  energy released when it burns.    what is the correct order?     less energy  released  more energy  released  a ethene ethane methane  b ethene methane ethane  c methane ethane ethene  d methane ethene ethane      38 which statements about ethanol are correct?    1 ethanol is made by reacting steam with ethene at 300  \u00b0c.  2 ethanol is made by fermentation at 55  \u00b0c.  3 ethanol burns to produce carbon dioxide and water.  4 ethanol contains a carbon-carbon double bond.    a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4     39 some properties of an organic compound j are listed.    \u25cf it is a liquid at room temperature.  \u25cf it is soluble in water.  \u25cf a solution of j reacts with calcium carbonate to form carbon dioxide.  \u25cf a solution of j has a ph of 3.    in which homologous series does j belong?  a alkane  b alkene  c alcohol  d carboxylic acid    ",
            "15": "15       permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2020 0620/11/m/j/20  40 which polymers or types of polymer are synthetic?    1 carbohydrates  2 nylon  3 proteins  4 terylene     a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    ",
            "16": "16  \u00a9 ucles 2020 0620/11/m/j/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s20_qp_12.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 06_0620_12/3rp   \u00a9 ucles 2020   [turn ove r   *1498871495*cambridge igcse\u2122       chemistry  0620/12     paper 1 multiple choice (core)  may/june 2020     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate num ber on the multiple choice answer sheet in the  spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/12/m/j/20  1 each rectangle shows the arrangement of particles in each of the three states of matter.    x, y and z represent the processes needed to change from one state to another.    zxy     what are the processes x, y and z?     x y z  a evaporating subliming condensing  b evaporating subliming freezing  c subliming evaporating condensing  d subliming evaporating freezing      2 which piece of apparatus is used to measure 25.0  cm3 of aqueous sodium hydroxide?    abcd       3 which process is used to produce drinking water from sea water?  a crystallisation  b distillation  c filtration  d chlorination     ",
            "3": "3     \u00a9 ucles 2020 0620/12/m/j/20 [turn over  4 the diagram shows the electronic structure of a particle with a nucleon number (mass number) of  40.    ee ee eeee e e ee ee ee ee 40     the table shows the suggestions that three students, 1, 2 and 3, made to identify the particle.   student   1 2 3  particle ar c l ca2+    which students are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3      5 the group i element sodium forms an ionic bond with the group vii element fluorine.    which two ions are produced?  a na+ and f+ b na+ and f\u2013 c na\u2013 and f\u2013 d na\u2013 and f+      6 the electronic structures of two atoms, p and q, are shown.    p q     p and q combine together to form a compound.    what is the type of bonding in the compound and what is the formula of the compound?     type of bonding formula  a ionic pq  b ionic pq 2  c covalent pq 2  d covalent pq   ",
            "4": "4  \u00a9 ucles 2020 0620/12/m/j/20  7 graphite is a macromolecule.    which statements about graphite are correct?    1 carbon atoms form four covalent bonds with neighbouring atoms.  2 there are free electrons between layers of carbon atoms. 3 graphite is a useful lubricant. 4 graphite is a good conductor of electricity.    a 1 and 2 b 1, 3 and 4 c 2, 3 and 4 d 3 and 4 only      8 aluminium oxide has the formula a l  2o3.     which statement about aluminium oxide is correct?  a 2 g of aluminium atoms are combined with 3  g of oxygen atoms.  b 2 g of aluminium atoms are combined with 3  g of oxygen molecules.  c aluminium oxide has a relative formula mass of 102.  d pure aluminium oxide contains a higher mass of oxygen than of aluminium.     9 dilute sulfuric acid is electrolysed using carbon electrodes.    which row shows the products formed at each electrode?     anode cathode  a hydrogen oxygen  b hydrogen sulfur  c oxygen hydrogen  d oxygen sulfur     10 which fuel does not rely on combustion to release energy?  a gasoline  b hydrogen  c methane  d uranium     ",
            "5": "5     \u00a9 ucles 2020 0620/12/m/j/20 [turn over  11 the energy level diagram shows the energy of the reactants and products in a chemical reaction.    reactants progress of reactionproductsenergy     which row correctly describes the energy change and the type of reaction shown?     description of  energy change type of reaction  a   energy is given out  to the surroundings endothermic    b   energy is given out  to the surroundings exothermic    c   energy is taken in from  the surroundings endothermic    d   energy is taken in from  the surroundings exothermic        12 which list contains only chemical changes?  a melting, evaporating, dissolving  b rusting, freezing, subliming  c neutralisation, polymerisation, combustion  d boiling, condensing, distillation     13 which row shows the changes that all increase the rate of a chemical reaction?     concentration  of reactants temperature particle size  a decrease decrease decrease  b decrease increase increase  c increase decrease increase  d increase increase decrease    ",
            "6": "6  \u00a9 ucles 2020 0620/12/m/j/20  14 which reaction is reversible?  a an iron nail rusting when left in moist air  b limestone reacting with an acid to form carbon dioxide gas  c magnesium burning in air to produce a white ash  d white anhydrous copper( ii) sulfate turning blue when water is added      15 when heated strongly, silicon( iv) oxide reacts with carbon.    sio 2  +  2c  \u2192  si  +  2co    which term describes what happens to silicon( iv) oxide?  a thermal decomposition  b neutralisation  c oxidation  d reduction    16 the graph shows how the ph of a solution changes as an acid is added to an alkali.    acid  +  alkali  \u2192  salt  +  water    which letter represents the area of the graph where both acid and salt are present?    pha b c d14 7 0 volume of acid added     17 element g is a metal in group i of the periodic table and element h is a non-metal in group vii.  both of these elements form oxides.    which statement about their oxides is correct?  a both oxides are acidic.  b both oxides are basic.  c the oxide of g is acidic and the oxide of h is basic.  d the oxide of h is acidic and the oxide of g is basic.   ",
            "7": "7     \u00a9 ucles 2020 0620/12/m/j/20 [turn over  18 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ysolid x aqueous copper( ii) sulfateexcess of solid xfilter paper heatstirrer     what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride dilute sulfuric acid  c copper( ii) oxide dilute sulfuric acid  d sulfur aqueous copper( ii) chloride      19 an aqueous solution of a compound m is tested.    the results are shown.    \u25cf it gave a lilac colour in a flame test.  \u25cf it produced a white precipitate when tested with acidified barium nitrate.    what is m?  a copper( ii) chloride  b copper( ii) sulfate  c potassium carbonate  d potassium sulfate    ",
            "8": "8  \u00a9 ucles 2020 0620/12/m/j/20  20 the character of the elements and charges on the ions of the elements change across the  periodic table.    which row describes the elements on the left of the table and the elements on the right?     elements on the left elements on the right  character charge on ion character charge on ion  a metallic positive non-metallic negative  b metallic negative non-metallic positive  c non-metallic positive metallic negative  d non-metallic negative metallic positive      21 which statement about group i and group vii elements is correct?  a group vii elements are monoatomic non-metals.  b lithium is more reactive with water than caesium.  c the melting points of group i metals increase down the group.  d potassium bromide reacts with chlorine to produce an orange solution.    22 the properties of the element titanium, ti, can be predicted from its position in the periodic table.    which row identifies the properties of titanium?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0016 \u0016 \u0016 \u001a  b \u0016 \u0016 \u001a \u0016  c \u0016 \u001a \u0016 \u0016  d \u001a \u0016 \u0016 \u0016      23 which diagram shows a mixture of noble gases?    a b c d      ",
            "9": "9     \u00a9 ucles 2020 0620/12/m/j/20 [turn over  24 which property is shown by all metals?  a they are extracted from their ores by heating with carbon.  b they conduct electricity.  c they form acidic oxides.  d they react with hydrochloric acid to form hydrogen.      25 the reactions of four metals, w, x, y and z, are shown.    metal observations  w reacts with steam and hydrochloric acid but not cold water  x reacts with hydrochloric acid but not with steam or cold water  y reacts with hydrochloric acid and cold water  z does not react with hydrochloric acid    what is the order of reactivity for metals w, x, y and z?     most  reactive  least  reactive  a y w x z  b y x w z  c z w x y  d z x w y      26 molten iron from the blast furnace contains impurities.    the process of turning the impure iron into steel involves blowing oxygen into the molten iron and  adding calcium oxide.    what are the reasons for blowing in oxygen and adding calcium oxide?     blowing in oxygen adding calcium oxide  a carbon is removed by reacting with oxygen reacts with acidic impurities making slag  b carbon is removed by reacting with oxyg en reacts with slag and so removes it  c iron reacts with the oxygen reacts with acidic impurities making slag  d iron reacts with the oxygen reacts with slag and so removes it     ",
            "10": "10  \u00a9 ucles 2020 0620/12/m/j/20  27 which statement about mild steel explains why it is a good choice for car bodies?  a it is cheap and strong.  b it is a good conductor.  c it is low density.  d it resists rusting.      28 which statement about pure water is not correct?  a it condenses at 100  \u00b0c.  b it freezes at 0  \u00b0c.  c it turns cobalt( ii) chloride paper blue.  d it turns anhydrous copper( ii) sulfate blue.      29 which compounds both  contribute to \u2018acid rain\u2019?  a carbon monoxide and lead compounds  b carbon monoxide and oxides of nitrogen  c oxides of nitrogen and sulfur dioxide  d sulfur dioxide and lead compounds      30 the diagrams show experiments to investigate rusting of iron nails.    3 boiled water2 salt water1 tap waterlayer of oil     in which test-tubes do the nails rust?  a 1 only b 1 and 2 only c 1 and 3 only d 1, 2 and 3     ",
            "11": "11     \u00a9 ucles 2020 0620/12/m/j/20 [turn over  31 which bag is not suitable for use as a fertiliser?    a ammonium nitrate nh4no3b potassium sulfate k2so4c sodium chloride nac ld sodium phosphate na3po4      32 x is a colourless greenhouse gas.    it is a waste product from digestion in animals.    it is generally unreactive, but it can be burnt.    what is x?  a carbon dioxide  b methane  c nitrogen  d sulfur dioxide    33 the list shows four methods that were suggested for the formation of carbon dioxide.    1 cracking methane using steam  2 action of heat on a carbonate 3 complete combustion of methane 4 reaction of a carbonate with oxygen    which methods would result in the production of carbon dioxide?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    34 a student suggests three uses of calcium carbonate (limestone).    1 manufacture of cement  2 manufacture of iron 3 treating alkaline soils    which suggestions are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3   ",
            "12": "12  \u00a9 ucles 2020 0620/12/m/j/20  35 which list shows the fractions obtained from distilling petroleum, in order of increasing boiling  point?  a bitumen \u2192 diesel oil \u2192 fuel oil \u2192 lubricating oil  b diesel oil \u2192 gasoline \u2192 naphtha \u2192 kerosene  c gasoline \u2192 naphtha \u2192 kerosene \u2192 diesel oil  d kerosene \u2192 lubricating oil \u2192 naphtha \u2192 refinery gas      36 the structures of four compounds are shown.    cch hhh hch hch12 hh hch hch3 ho h hch hc ch hhh4 h    which compounds are members of the same homologous series?  a 1 and 2 only b 1 and 4 c 1, 2 and 3 d 2 and 4      37 increasing the number of atoms in one molecule of a hydrocarbon increases the amount of  energy released when it burns.    what is the correct order?     less energy  released  more energy  released  a ethene ethane methane  b ethene methane ethane  c methane ethane ethene  d methane ethene ethane      38 which statement about alcohols is correct?  a alcohols and carboxylic acids have the same functional group.  b ethanoic acid is produced from the reduction of ethanol.  c ethanol is produced in an addition reaction between ethene and hydrogen.  d water is produced from the combustion of alcohols.    ",
            "13": "13     \u00a9 ucles 2020 0620/12/m/j/20  39 an organic compound, p, reacts with zinc to produce a gas, q.    what are p and q?     p q  a ethanoic acid carbon dioxide  b ethanoic acid hydrogen  c ethanol carbon dioxide  d ethanol hydrogen     40 which substances are natural polymers?    1 proteins  2 carbohydrates 3 nylon 4 poly(ethene)    a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4    ",
            "14": "14  \u00a9 ucles 2020 0620/12/m/j/20  blank page",
            "15": "15       permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2020 0620/12/m/j/20  blank page",
            "16": "16  \u00a9 ucles 2020 0620/12/m/j/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s20_qp_13.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 06_0620_13/3rp   \u00a9 ucles 2020   [turn ove r   *3429027885*cambridge igcse\u2122       chemistry  0620/13     paper 1 multiple choice (core)  may/june 2020     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate num ber on the multiple choice answer sheet in the  spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/13/m/j/20  1 descriptions of the three states of matter are shown.     particle  separation particle  arrangement type of motion  1 small random move past each other at low speed  2 large random rapid motion in straight lines  3 small regular vibration    which row is correct?     1 2 3  a gas liquid solid  b liquid solid gas  c liquid gas solid  d solid gas liquid     2 which piece of apparatus is used to measure 13.7  cm3 of dilute hydrochloric acid?  a balance  b burette  c conical flask  d pipette     3 ethanol can be made by fermentation of sugar, using yeast.    this produces a mixture of ethanol and water.    how is ethanol separated from this mixture?  a filter the mixture.  b heat to evaporate the water.  c heat to evaporate most of the water, and allow the ethanol to crystallise.  d distil the mixture using a fractionating column.     ",
            "3": "3     \u00a9 ucles 2020 0620/13/m/j/20 [turn over  4 the structure of an atom of element x is shown.    5p 6nkey = electron = neutron = protonnp     what is element x?  a boron  b carbon  c sodium  d sulfur     5 which statement about the bonding in sodium chloride is correct?  a pairs of electrons are shared between the sodium and chlorine atoms.  b chlorine atoms give electrons to sodium atoms to form positive and negative ions.  c there is covalent bonding between sodium and chlorine.  d the positive and negative ions have noble gas electronic structures.     6 the electronic structures of two atoms, p and q, are shown.    p q     p and q combine together to form a compound.    what is the type of bonding in the compound and what is the formula of the compound?     type of bonding formula  a ionic pq  b ionic pq 2  c covalent pq 2  d covalent pq     ",
            "4": "4  \u00a9 ucles 2020 0620/13/m/j/20  7 diamond and graphite are macromolecules.    which statement is correct for both diamond and graphite?  a they act as lubricants.  b they conduct electricity.  c they have high melting points.  d they are very hard.      8 aluminium oxide has the formula a l 2o3.     which statement about aluminium oxide is correct?  a 2 g of aluminium atoms are combined with 3  g of oxygen atoms.  b 2 g of aluminium atoms are combined with 3  g of oxygen molecules.  c aluminium oxide has a relative formula mass of 102.  d pure aluminium oxide contains a higher mass of oxygen than of aluminium.      9 which statement about electrolysis is not correct?  a bromine is produced at the cathode in the electrolysis of molten lead bromide.  b electrolysis is the breakdown of a substance by electricity.  c hydrogen is one of the products in the electrolysis of concentrated aqueous sodium chloride.  d platinum is used as an inert electrode.     10 which statements about  235u are correct?    1 it is a radioactive isotope.  2 it burns in air to produce greenhouse gases. 3 it is used as an energy source.    a 1 only b 1 and 3 only c 1, 2 and 3 d 2 and 3 only     ",
            "5": "5     \u00a9 ucles 2020 0620/13/m/j/20 [turn over  11 the energy level diagram shows the energy of the reactants and products in a chemical reaction.    reactants progress of reactionproductsenergy     which row correctly describes the energy change and the type of reaction shown?     description of  energy change type of reaction  a   energy is given out  to the surroundings endothermic    b   energy is given out  to the surroundings exothermic    c   energy is taken in from  the surroundings endothermic    d   energy is taken in from  the surroundings exothermic       12 in which tube is a physical change taking place?    a water iron nailb water sodium chloridec dilute hydrochloric aciddilute hydrochloric acidd calcium carbonatemagnesium     ",
            "6": "6  \u00a9 ucles 2020 0620/13/m/j/20  13 magnesium is reacted with dilute hydrochloric acid of the same concentration in four experiments  using different conditions.    which reaction finished in the shortest time?  a 2  g of magnesium powder in 50  cm3 of dilute hc l at 45  \u00b0c  b 2  g of magnesium powder in 50  cm3 of dilute hc l at 50  \u00b0c  c 2  g of magnesium ribbon in 50  cm3 of dilute hc l at 45  \u00b0c  d 2  g of magnesium ribbon in 50  cm3 of dilute hc l at 50  \u00b0c      14 blue copper( ii) sulfate crystals are heated in air until they turn into a white powder.    the powder is allowed to cool and after a few days it starts to turn blue.    why does the white powder start to turn blue?  a carbon dioxide in the air reacts with the powder to form copper( ii) carbonate.  b the powder reacts with water in the air to form copper( ii) hydroxide.  c the white copper compound is slowly oxidised.  d water is absorbed from the air and causes the reaction to reverse.    15 steam reacts with carbon to produce carbon monoxide and hydrogen.    c(s)  +  h 2o(g)  \u2192  co(g)  +  h 2(g)    which substance is reduced in the reaction?  a carbon  b carbon monoxide  c hydrogen  d water    ",
            "7": "7     \u00a9 ucles 2020 0620/13/m/j/20 [turn over  16 the graph shows how the ph of a solution changes as an acid is added to an alkali.    acid  +  alkali  \u2192  salt  +  water    which letter represents the area of the graph where both acid and salt are present?    pha b c d14 7 0 volume of acid added      17 element e is in group ii of the periodic table.    which row describes element e and its oxide?     element e oxide of e  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic     ",
            "8": "8  \u00a9 ucles 2020 0620/13/m/j/20  18 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ysolid x aqueous copper( ii) sulfateexcess of solid xfilter paper heatstirrer     what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride dilute sulfuric acid  c copper( ii) oxide dilute sulfuric acid  d sulfur aqueous copper( ii) chloride      19 four different colourless solutions are each tested separately with aqueous sodium hydroxide  and with acidified silver nitrate.    which solution is sodium chloride?     aqueous  sodium hydroxide acidified  silver nitrate  a no visible reaction white precipitate  b no visible reaction no visible reaction  c white precipitate no visible reaction  d white precipitate white precipitate      20 which statement about elements in period 3 of the periodic table is correct?  a aluminium is a non-metal in group iii.  b argon is in group viii and has eight electrons in its outer shell.  c magnesium is in group ii and has three electrons in its outer shell.  d sulfur is a metal in group vi.    ",
            "9": "9     \u00a9 ucles 2020 0620/13/m/j/20 [turn over  21 the elements in group i include lithium, sodium and potassium.    which statements about these elements are correct?    1 sodium is denser than lithium.  2 lithium has a lower melting point than potassium. 3 potassium is a relatively soft metal. 4 sodium is less reactive than lithium but more reactive than potassium.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     22 the properties of the element titanium, ti, can be predicted from its position in the periodic table.    which row identifies the properties of titanium?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0016 \u0016 \u0016 \u001a  b \u0016 \u0016 \u001a \u0016  c \u0016 \u001a \u0016 \u0016  d \u001a \u0016 \u0016 \u0016      23 which statement about the noble gases is correct?  a argon is used in light bulbs and balloons.  b helium reacts with oxygen in the air.  c they all have full outer electron shells.  d they are all diatomic molecules.     24 which property is shown by all metals?  a they are extracted from their ores by heating with carbon.  b they conduct electricity.  c they form acidic oxides.  d they react with hydrochloric acid to form hydrogen.    ",
            "10": "10  \u00a9 ucles 2020 0620/13/m/j/20  25 p, q, r and s are metals.    p reacts with dilute hydrochloric acid forming hydrogen.    q reacts violently with water.    r reacts with water to give hydrogen.    s is formed by heating its oxide with carbon    which row identifies the metals?     p q r s  a copper sodium potassium iron  b zinc magnesium calcium iron  c zinc sodium calcium magnesium  d iron potassium sodium zinc      26 molten iron from the blast furnace contains impurities.    the process of turning the impure iron into steel involves blowing oxygen into the molten iron and  adding calcium oxide.    what are the reasons for blowing in oxygen and adding calcium oxide?     blowing in oxygen adding calcium oxide  a carbon is removed by reacting with oxygen reacts with acidic impurities making slag  b carbon is removed by reacting with oxyg en reacts with slag and so removes it  c iron reacts with the oxygen reacts with acidic impurities making slag  d iron reacts with the oxygen reacts with slag and so removes it      27 why is stainless steel used to make cutlery?  a it does not corrode.  b it has a low density.  c it is a good conductor of electricity.  d it is a good conductor of heat.    ",
            "11": "11     \u00a9 ucles 2020 0620/13/m/j/20 [turn over  28 which substances can be used to detect the presence of water?    1 cobalt( ii) chloride  2 copper( ii) sulfate  3 litmus  4 methyl orange    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     29 which two compounds are formed by the burning of fossil fuels and are atmospheric pollutants?  a carbon dioxide and hydrogen chloride  b carbon monoxide and sulfur dioxide  c oxides of nitrogen and water  d oxides of nitrogen and ammonia    30 the diagrams show experiments to investigate rusting of iron nails.    3 boiled water2 salt water1 tap waterlayer of oil     in which test-tubes do the nails rust?  a 1 only b 1 and 2 only c 1 and 3 only d 1, 2 and 3    ",
            "12": "12  \u00a9 ucles 2020 0620/13/m/j/20  31 a farmer knows his soil needs phosphorus and potassium.    he has a choice of four fertilisers.    1 nh 4no 3  2 (nh 4)3po 4  3 kno 3  4 (nh 2)2co    which fertilisers should he use?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4      32 which process is a source of methane?  a respiration  b combustion of ethanol  c decomposition of calcium carbonate  d decomposition of vegetation      33 the list shows four methods that were suggested for the formation of carbon dioxide.    1 cracking methane using steam  2 action of heat on a carbonate  3 complete combustion of methane  4 reaction of a carbonate with oxygen    which methods would result in the production of carbon dioxide?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     34 a student suggests three uses of calcium carbonate (limestone).    1 manufacture of cement  2 manufacture of iron 3 treating alkaline soils    which suggestions are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    ",
            "13": "13     \u00a9 ucles 2020 0620/13/m/j/20 [turn over  35 which list shows the fractions obtained from distilling petroleum, in order of increasing boiling  point?  a bitumen \u2192 diesel oil \u2192 fuel oil \u2192 lubricating oil  b diesel oil \u2192 gasoline \u2192 naphtha \u2192 kerosene  c gasoline \u2192 naphtha \u2192 kerosene \u2192 diesel oil  d kerosene \u2192 lubricating oil \u2192 naphtha \u2192 refinery gas      36 which structure represents a compound in the alcohol homologous series?    o oa ch hh ch hhb ch hc hch hhd c c hh c hh h hc ch oc hh hh ch hh      37 increasing the number of atoms in one molecule of a hydrocarbon increases the amount of  energy released when it burns.    what is the correct order?     less energy  released  more energy  released  a ethene ethane methane  b ethene methane ethane  c methane ethane ethene  d methane ethene ethane      38 compound x has the molecular formula c 2h6o.    which statement about compound x is correct?  a x is unsaturated.  b x is a carboxylic acid.  c x is formed by the reaction of ethane with steam.  d x is used as a fuel.    ",
            "14": "14  \u00a9 ucles 2020 0620/13/m/j/20  39 a small quantity of a solid chemical is added to a large excess of aqueous ethanoic acid.    no bubbles of gas are seen and the solid dissolves to give a colourless solution.    what was the solid chemical?  a calcium hydroxide  b copper( ii) oxide  c magnesium  d sodium carbonate     40 which statement about carbohydrates and proteins is correct?  a carbohydrates and proteins are constituents of food.  b carbohydrates and proteins are natural polymers used to make larger molecules called  monomers.  c carbohydrates and proteins are synthetic polymers.  d carbohydrates and proteins cause pollution as they are non-biodegradable.    ",
            "15": "15       permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2020 0620/13/m/j/20  blank page",
            "16": "16  \u00a9 ucles 2020 0620/13/m/j/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s20_qp_21.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 06_0620_21/2rp   \u00a9 ucles 2020   [turn ove r   *4599385782 *cambridge igcse\u2122       chemistry  0620/21     paper 2 multiple choice (extended)  may/june 2020     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate num ber on the multiple choice answer sheet in the  spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/21/m/j/20  1 a mixture of ice and water is left to stand and the ice melts.    which row describes what happens as the ice is melting?     temperature of mixture energy changes  a increases average kinetic energy of particles increases  b increases energy is used to overcome attractive forces   c stays the same average kinetic energy of particles increases  d stays the same energy is used to overcome attractive forces       2 which piece of apparatus should be used to measure exactly 21.4  cm3 of water?  a 25  cm3 beaker  b 25  cm3 pipette  c 50  cm3 burette  d 50  cm3 measuring cylinder     3 the chromatogram for an unknown dye is shown.    12 cm15 cm 2 cm9 cmsolvent front     what is the rf value of the dye?  a 0.60 b 0.64 c 0.75 d 0.82    ",
            "3": "3     \u00a9 ucles 2020 0620/21/m/j/20 [turn over  4 the atomic number and nucleon number of a potassium atom are shown.     potassium atom  atomic number 19  nucleon number 39    how many protons, neutrons and electrons are in a potassium ion, k+?     protons neutrons electrons  a 19 20 18  b 19 20 20  c 20 19 18  d 20 19 19      5 the electronic structures of two atoms, p and q, are shown.    p q     p and q combine together to form a compound.    what is the type of bonding in the compound and what is the formula of the compound?     type of bonding formula  a ionic pq  b ionic pq 2  c covalent pq 2  d covalent pq    ",
            "4": "4  \u00a9 ucles 2020 0620/21/m/j/20  6 which row contains a description of metallic bonding and a property that is explained by  reference to metallic bonding?     description of  metallic bonding property explained by  metallic bonding  a   a lattice of negative ions  in a sea of electrons a metal will react with an  acid, producing hydrogen  b   a lattice of negative ions  in a sea of electrons a piece of a metal can be  moulded into different shapes  c   a lattice of positive ions  in a sea of electrons a metal will react with an  acid, producing hydrogen  d   a lattice of positive ions  in a sea of electrons a piece of a metal can be  moulded into different shapes     7 which statement explains why methane has a lower boiling point than water?  a methane has weaker covalent bonds than water.  b methane has weaker attractive forces than water.  c methane molecules are heavier than water molecules.  d methane molecules have more bonds than water molecules.     8 a solution of iron( iii) sulfate reacts with aqueous sodium hydroxide to form a red\u2013brown  precipitate.    what is the balanced equation, including state symbols, for the reaction?  a feso 4(aq)  +  2naoh(aq)  \u2192  fe(oh) 2(s)  +  na 2so 4(aq)  b feso 4(l)  +  2naoh(l)  \u2192  fe(oh) 2(s)  +  na 2so 4(l)  c fe 2(so 4)3(aq)  +  6naoh(aq)  \u2192  2fe(oh) 3(s)  +  3na 2so 4(aq)  d fe 2(so 4)3(l)  +  6naoh(aq)  \u2192  2fe(oh) 3(s)  +  3na 2so 4(l)     9 the haber process is a reversible reaction.    n 2(g)  +  3h 2(g)    2nh 3(g)    the reaction has a 30% yield of ammonia.    which volume of ammonia gas, nh 3, measured at room temperature and pressure, is obtained  by reacting 0.75 moles of hydrogen with excess nitrogen?  a 3600  cm3 b 5400  cm3 c 12  000  cm3 d 18  000  cm3    ",
            "5": "5     \u00a9 ucles 2020 0620/21/m/j/20 [turn over  10 dilute aqueous sodium chloride is electrolysed using platinum electrodes.    what is the half-equation for the reaction at the cathode?  a 2h+  +  2e\u2013  \u2192  h2  b na+  +  e\u2013  \u2192  na  c 2c l \u2013  \u2192  c l 2  +  2e\u2013  d 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013      11 the electrolysis of aqueous copper( ii) sulfate, using inert electrodes, is shown.    aqueous copper( ii) sulfate+\u2013     which statement about a reaction at an electrode is correct?  a copper ions gain electrons at the negative electrode.  b copper ions gain electrons at the positive electrode.  c hydrogen ions gain electrons at the negative electrode.  d hydrogen ions gain electrons at the positive electrode.    ",
            "6": "6  \u00a9 ucles 2020 0620/21/m/j/20  12 the equation for the complete combustion of methane gas is shown.    ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(g)    bond energies are shown.    bond bond energy  in kj  / mol  c\u2013h 412  h\u2013o 463  c=o 743  o=o 498    what is the overall energy change, in kj  / mol, for the above reaction?  a \u20131192 b \u2013694 c +694 d +1192    13 which statements about hydrogen fuel cells are correct?    1 water is formed as the only waste product.  2 both water and carbon dioxide are formed as waste products.  3 the overall reaction is  2h 2  +  o 2  \u2192  2h 2o.  4 the overall reaction is endothermic.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    14 which diagram represents a chemical change?    a b c d      ",
            "7": "7     \u00a9 ucles 2020 0620/21/m/j/20 [turn over  15 the rate of reaction between calcium carbonate chips and hydrochloric acid is studied by  collecting the volume of gas released in one minute at different temperatures.    a graph of rate of reaction against temperature is shown.    80 70605040302010 0rate of reaction cm 3 / min temperature  / \u00b0c0 1 02 03 04 05 06 0     which statement fully explains why increasing the temperature has this effect on the rate?  a the kinetic energy of the particles increases so the collisions are harder.  b the number of collisions between particles increases.  c the activation energy needed for the particles to react is reduced.  d there are more frequent collisions between particles with enough energy to react.     16 the equation shows the equilibrium between dinitrogen tetroxide, n 2o4, and nitrogen dioxide,  no 2.    the colours of the reactant and product are also shown.    n2o4(g)    2no 2(g)   colourless brown    the forward reaction is endothermic.    which statement is not correct?  a at equilibrium the concentrations of the reactant and the product are constant.  b at equilibrium the rate of the forward reaction is equal to the rate of the reverse reaction.  c when the pressure is increased a darker brown colour is seen.  d when the temperature is increased a darker brown colour is seen.    ",
            "8": "8  \u00a9 ucles 2020 0620/21/m/j/20  17 the equations for two reactions of iodide ions are shown.    reaction 1 2 i\u2013(aq)  +  h 2o2(aq)  \u2192  i2(aq)  +  2oh\u2013(aq)  reaction 2  i\u2013(aq)  +  ag+(aq)  \u2192  agi(s)    which statement is correct?  a both reactions are redox reactions.  b neither reaction is a redox reaction.  c only reaction 1 is a redox reaction.  d only reaction 2 is a redox reaction.    18 the graph shows how the ph of a solution changes as an acid is added to an alkali.    acid  +  alkali  \u2192  salt  +  water    which letter represents the area of the graph where both acid and salt are present?    pha b c d14 7 0 volume of acid added      19 which statement describes a weak acid?  a it is a proton acceptor and is fully ionised in aqueous solution.  b it is a proton acceptor and is partially ionised in aqueous solution.  c it is a proton donor and is fully ionised in aqueous solution.  d it is a proton donor and is partially ionised in aqueous solution.    ",
            "9": "9     \u00a9 ucles 2020 0620/21/m/j/20 [turn over  20 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ysolid x aqueous copper( ii) sulfateexcess of solid xfilter paper heatstirrer     what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride dilute sulfuric acid  c copper( ii) oxide dilute sulfuric acid  d sulfur aqueous copper( ii) chloride      21 lead( ii) sulfate is an insoluble salt.    which method is suitable for obtaining solid lead( ii) sulfate?  a mix aqueous lead( ii) nitrate and aqueous potassium sulfate, heat to evaporate all of the  water, collect the solid and then wash and dry it.  b mix aqueous lead( ii) nitrate and aqueous potassium sulfate, filter, collect the filtrate,  crystallise, then wash and dry the crystals.  c mix aqueous lead( ii) nitrate and dilute sulfuric acid, filter, then wash and dry the residue.  d titrate aqueous lead( ii) hydroxide with dilute sulfuric acid, crystallise, then wash and dry the  crystals.     22 a group i metal (lithium, sodium or potassium) is reacted with a group vii element (chlorine,  bromine or iodine).    which compound is formed when the group i metal of highest density reacts with the group vii  element of lowest density?  a lithium chloride  b potassium chloride  c potassium iodide  d lithium iodide   ",
            "10": "10  \u00a9 ucles 2020 0620/21/m/j/20  23 the properties of the element titanium, ti, can be predicted from its position in the periodic table.    which row identifies the properties of titanium?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0016 \u0016 \u0016 \u001a  b \u0016 \u0016 \u001a \u0016  c \u0016 \u001a \u0016 \u0016  d \u001a \u0016 \u0016 \u0016     24 a balloon is filled with helium. helium is a noble gas and makes the balloon rise up in the air.    the density of air is 1.23  g / dm3.    which gas is helium?     density in g  / dm3 reaction with oxygen  a 0.0899 burns rapidly  b 0.179 does not react with oxygen  c 1.78 does not react with oxygen  d 3.75 does not react with oxygen      25 which property is shown by all metals?  a they are extracted from their ores by heating with carbon.  b they conduct electricity.  c they form acidic oxides.  d they react with hydrochloric acid to form hydrogen.     ",
            "11": "11     \u00a9 ucles 2020 0620/21/m/j/20 [turn over  26 sodium nitrate is a white crystalline solid that decomposes on heating.    heatsodium nitrate     which row describes the decomposition products fo rmed when sodium nitrate is heated strongly?     solid products gaseous products  a sodium nitrite no 2 and o 2  b sodium nitrite o 2 only  c sodium oxide no 2 and o 2  d sodium oxide o 2 only     27 molten iron from the blast furnace contains impurities.    the process of turning the impure iron into steel involves blowing oxygen into the molten iron and  adding calcium oxide.    what are the reasons for blowing in oxygen and adding calcium oxide?     blowing in oxygen adding calcium oxide  a carbon is removed by reacting with oxygen reacts with acidic impurities making slag  b carbon is removed by reacting with oxyg en reacts with slag and so removes it  c iron reacts with the oxygen reacts with acidic impurities making slag  d iron reacts with the oxygen reacts with slag and so removes it      28 element y reacts with copper( ii) oxide to form copper.    element y will not react with zinc oxide. copper has no reaction with zinc oxide.    what is the order of reactivity of these three elements, most reactive first?  a cu \u2192 y \u2192 zn  b cu \u2192 zn \u2192 y  c zn \u2192 cu \u2192 y  d zn \u2192 y \u2192 cu     ",
            "12": "12  \u00a9 ucles 2020 0620/21/m/j/20  29 which statement shows that a liquid is pure water?  a it boils at 100  \u00b0c.  b it has a ph value of 7.  c it turns blue cobalt( ii) chloride pink.  d it turns white copper( ii) sulfate blue.     30 which process removes carbon dioxide from the atmosphere?  a combustion  b decomposition  c photosynthesis  d respiration     31 ammonia is manufactured by the haber process.     n 2(g)  +  3h 2(g)    2nh 3(g)    what are the conditions used in the haber process?     temperature  / \u00b0c pressure  / atm  a 400 100  b 400 300  c 20 300  d 20 100     32 coating iron helps to prevent rusting.    which coating will continue to protect the iron even when the coating is damaged?  a copper  b paint  c plastic  d zinc     ",
            "13": "13     \u00a9 ucles 2020 0620/21/m/j/20 [turn over  33 a student suggests three uses of calcium carbonate (limestone).    1 manufacture of cement  2 manufacture of iron  3 treating alkaline soils    which suggestions are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    34 the contact process is used to manufacture concentrated sulfuric acid and consists of four steps.    which step involves a catalyst?  a production of sulfur dioxide gas  b production of sulfur trioxide gas  c production of oleum  d production of concentrated sulfuric acid     35 which row about the production of ethanol by fermentation is correct?     raw materials energy requirement rate of reaction  a non-renewable high slow  b renewable low slow  c non-renewable low fast  d renewable high fast     36 which statement about homologous series is correct?  a members of a homologous series have the same structural formula.  b members of a homologous series all have similar chemical properties.  c members of a homologous series all have similar physical properties.  d members of all homologous series are hydrocarbons.    ",
            "14": "14  \u00a9 ucles 2020 0620/21/m/j/20  37 increasing the number of atoms in one molecule of a hydrocarbon increases the amount of  energy released when it burns.    what is the correct order?     less energy  released  more energy  released  a ethene ethane methane  b ethene methane ethane  c methane ethane ethene  d methane ethene ethane     38 some properties of an organic compound j are listed.    \u25cf it is a liquid at room temperature.  \u25cf it is soluble in water.  \u25cf a solution of j reacts with calcium carbonate to form carbon dioxide.  \u25cf a solution of j has a ph of 3.    in which homologous series does j belong?  a alkane  b alkene  c alcohol  d carboxylic acid      39 ethane, c 2h6, reacts with chlorine in a substitution reaction.    what are the products of this reaction?  a chloroethane and hydrogen  b chloroethane and hydrogen chloride  c chloroethene and hydrogen  d chloroethene and hydrogen chloride    ",
            "15": "15       permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2020 0620/21/m/j/20  40 which polymers or types of polymer are synthetic?    1 carbohydrates  2 nylon  3 proteins  4 terylene     a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    ",
            "16": "16  \u00a9 ucles 2020 0620/21/m/j/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s20_qp_22.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 06_0620_22/2rp   \u00a9 ucles 2020   [turn ove r   *8601179553 *cambridge igcse\u2122       chemistry 0620/22     paper 2 multiple choice (extended)  may/june 2020     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate num ber on the multiple choice answer sheet in the  spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/22/m/j/20  1 a mixture of ice and water is left to stand and the ice melts.    which row describes what happens as the ice is melting?     temperature of mixture energy changes  a increases average kinetic energy of particles increases  b increases energy is used to overcome attractive forces   c stays the same average kinetic energy of particles increases  d stays the same energy is used to overcome attractive forces      2 which piece of apparatus is used to measure 25.0  cm3 of aqueous sodium hydroxide?    abcd     3 paper chromatography is used to determine the r f values for four different food colourings.    which food colouring has an rf value of 0.6?    25 201510 50solvent front baseline abcddistance / cm      ",
            "3": "3     \u00a9 ucles 2020 0620/22/m/j/20 [turn over  4 the diagram shows the electronic structure of a particle with a nucleon number (mass number) of  40.    ee ee eeee e e ee ee ee ee 40     the table shows the suggestions that three students, 1, 2 and 3, made to identify the particle.   student   1 2 3  particle ar c l ca2+    which students are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3      5 the electronic structures of two atoms, p and q, are shown.    p q     p and q combine together to form a compound.    what is the type of bonding in the compound and what is the formula of the compound?     type of bonding formula  a ionic pq  b ionic pq 2  c covalent pq 2  d covalent pq    ",
            "4": "4  \u00a9 ucles 2020 0620/22/m/j/20  6 which statement about the structure of a metal explains why metals are malleable?  a the electrons can move freely throughout the lattice.  b the layers of metal ions can slide over each other.  c the metal ions are positively charged.  d there is a strong force of attraction between the metal ions and the electrons.      7 the bonding, structure and melting point of sodium chloride and sulfur dichloride are shown.    compound bonding structure melting point  / \u00b0c  sodium chloride ionic giant lattice 801  sulfur dichloride covalent simple molecular \u2013121    why does sulfur dichloride have a lower melting point than sodium chloride?  a the covalent bonds in sulfur dichloride are weaker than the attractive forces between  molecules in sodium chloride.  b the covalent bonds in sulfur dichloride are weaker than the ionic bonds in sodium chloride.  c the attractive forces between molecules in sulfur dichloride are weaker than the attractive  forces between molecules in sodium chloride.  d the attractive forces between molecules in sulfur dichloride are weaker than the ionic bonds  in sodium chloride.      8 lead( ii) nitrate, pb(no 3)2, reacts with potassium iodide, k i, to form a yellow precipitate, pb i2,  and a soluble salt, kno 3.    what is the equation for the reaction?  a pb(no 3)2  +  k i  \u2192  pb i2  +  kno 3  b pb(no 3)2  +  2k i  \u2192  pb i2  +  kno 3  c 2pb(no 3)2  +  2k i  \u2192  pb i2  +  2kno 3  d pb(no 3)2  +  2k i  \u2192  pb i2  +  2kno 3     9 the haber process is a reversible reaction.    n 2(g)  +  3h 2(g)    2nh 3(g)    the reaction has a 30% yield of ammonia.    which volume of ammonia gas, nh 3, measured at room temperature and pressure, is obtained  by reacting 0.75 moles of hydrogen with excess nitrogen?  a 3600  cm3 b 5400  cm3 c 12  000  cm3 d 18  000  cm3     ",
            "5": "5     \u00a9 ucles 2020 0620/22/m/j/20 [turn over  10 electrolytes can be broken down by electrolysis.    which rows are correct for each electrolyte?     electrolyte reaction  at cathode product  at anode  1 dilute aqueous sodium chloride 2h+  +  2e\u2013  \u2192  h2 oxygen  2 concentrated hydrochloric acid 2h+  +  2e\u2013  \u2192  h2 chlorine  3 molten aluminium oxide 2o2\u2013  \u2192  o 2  +  4e\u2013 aluminium  4 concentrated aqueous sodium bromide na+  +  e\u2013  \u2192  na bromine    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     11 the electrolysis of aqueous copper( ii) sulfate, using inert electrodes, is shown.    aqueous copper( ii) sulfate+\u2013     which statement about a reaction at an electrode is correct?  a copper ions gain electrons at the negative electrode.  b copper ions gain electrons at the positive electrode.  c hydrogen ions gain electrons at the negative electrode.  d hydrogen ions gain electrons at the positive electrode.     ",
            "6": "6  \u00a9 ucles 2020 0620/22/m/j/20  12 methane burns in excess oxygen.    the equation is shown.    ch 4(g)  +  2o 2(g)  \u2192  co 2(g)  +  2h 2o(g)    bond energies are shown.    bond bond energy  / kj mol\u20131  c=o 805  c\u2013h 410  o=o 496  o\u2013h 460    what is the energy change for the reaction?  a  (4 \u00d7 410 + 2 \u00d7 496) \u2013 (2 \u00d7 805 + 4 \u00d7 460)   b (2 \u00d7 805 + 2 \u00d7 460) \u2013 (410 + 2 \u00d7 496)   c (410 + 2 \u00d7 496) \u2013 (805 + 2 \u00d7 460)   d (410 + 496) \u2013 (805 + 460)      13 which statements about hydrogen fuel cells are correct?    1 water is formed as the only waste product.  2 both water and carbon dioxide are formed as waste products.  3 the overall reaction is  2h 2  +  o 2  \u2192  2h 2o.  4 the overall reaction is endothermic.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      14 which list contains only chemical changes?  a melting, evaporating, dissolving  b rusting, freezing, subliming  c neutralisation, polymerisation, combustion  d boiling, condensing, distillation    ",
            "7": "7     \u00a9 ucles 2020 0620/22/m/j/20 [turn over  15 the results of adding excess marble chips (calcium carbonate) to hydrochloric acid at 50  \u00b0c and  at 30  \u00b0c are shown. only the temperature is changed.    volume of carbon dioxidegiven off  / cm3 time  / s 0050 \u00b0c 30 \u00b0c     which row describes the reacting particles at 30  \u00b0c compared to those at 50  \u00b0c?     collision rate collision energy  a higher higher  b higher lower  c lower higher  d lower lower     16 methane reacts with steam and an equilibrium is reached.    ch 4(g)  +  h 2o(g)    co(g)  +  3h 2(g)    the forward reaction is endothermic.    which row shows how the amount of hydrogen at equilibrium changes when the pressure or  temperature is changed as indicated?     change in  temperature change in  pressure amount of  hydrogen  a decrease no change increase  b increase no change decrease  c no change increase decrease  d no change decrease decrease     ",
            "8": "8  \u00a9 ucles 2020 0620/22/m/j/20  17 when aqueous iron( iii) chloride is added to aqueous potassium iodide a chemical reaction  occurs and iodine is formed.    which statement is correct?  a iodide ions are oxidised, they gain electrons in this reaction.  b iodide ions are oxidised, they lose electrons in this reaction.  c iron( iii) chloride is oxidised in this reaction.  d neither iodide ions nor iron( iii) chloride is oxidised in this reaction.      18 the graph shows how the ph of a solution changes as an acid is added to an alkali.    acid  +  alkali  \u2192  salt  +  water    which letter represents the area of the graph where both acid and salt are present?    pha b c d14 7 0 volume of acid added      19 which statement describes a weak acid?  a it is a proton acceptor and is fully ionised in aqueous solution.  b it is a proton acceptor and is partially ionised in aqueous solution.  c it is a proton donor and is fully ionised in aqueous solution.  d it is a proton donor and is partially ionised in aqueous solution.     ",
            "9": "9     \u00a9 ucles 2020 0620/22/m/j/20 [turn over  20 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ysolid x aqueous copper( ii) sulfateexcess of solid xfilter paper heatstirrer     what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride dilute sulfuric acid  c copper( ii) oxide dilute sulfuric acid  d sulfur aqueous copper( ii) chloride      21 which process is not used in the preparation of an insoluble salt?  a filtration  b washing  c crystallisation  d drying      22 which statement about group i and group vii elements is correct?  a group vii elements are monoatomic non-metals.  b lithium is more reactive with water than caesium.  c the melting points of group i metals increase down the group.  d potassium bromide reacts with chlorine to produce an orange solution.     ",
            "10": "10  \u00a9 ucles 2020 0620/22/m/j/20  23 the properties of the element titanium, ti, can be predicted from its position in the periodic table.    which row identifies the properties of titanium?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0016 \u0016 \u0016 \u001a  b \u0016 \u0016 \u001a \u0016  c \u0016 \u001a \u0016 \u0016  d \u001a \u0016 \u0016 \u0016     24 which diagram shows a mixture of noble gases?    a b c d       25 which property is shown by all metals?  a they are extracted from their ores by heating with carbon.  b they conduct electricity.  c they form acidic oxides.  d they react with hydrochloric acid to form hydrogen.    26 many metal carbonates decompose when they are heated.    which row describes what happens when potassium carbonate, calcium carbonate and  copper( ii) carbonate are heated using a bunsen burner?     decomposes easily decomposes  with difficulty does not decompose at  bunsen temperatures  a calcium carbonate copper( ii) carbonate potassium carbonate  b copper( ii) carbonate calcium carbonate potassium carbonate  c copper( ii) carbonate potassium carbonate calcium carbonate  d potassium carbonate calcium carbonate copper( ii) carbonate     ",
            "11": "11     \u00a9 ucles 2020 0620/22/m/j/20 [turn over  27 molten iron from the blast furnace contains impurities.    the process of turning the impure iron into steel involves blowing oxygen into the molten iron and  adding calcium oxide.    what are the reasons for blowing in oxygen and adding calcium oxide?     blowing in oxygen adding calcium oxide  a carbon is removed by reacting with oxygen reacts with acidic impurities making slag  b carbon is removed by reacting with oxyg en reacts with slag and so removes it  c iron reacts with the oxygen reacts with acidic impurities making slag  d iron reacts with the oxygen reacts with slag and so removes it      28 four iron nails are added to four different metal sulfate solutions.    in which solution does a displacement reaction occur?  a copper( ii) sulfate  b magnesium sulfate  c sodium sulfate  d zinc sulfate      29 which statement about pure water is not correct?  a it condenses at 100  \u00b0c.  b it freezes at 0  \u00b0c.  c it turns cobalt( ii) chloride paper blue.  d it turns anhydrous copper( ii) sulfate blue.     ",
            "12": "12  \u00a9 ucles 2020 0620/22/m/j/20  30 three processes in the carbon cycle are shown.    1 methane reacts with oxygen producing carbon dioxide and water.  2 carbon dioxide and water are absorbed and used by plants to make oxygen.  3 oxygen is used by living things to release energy.    which processes have taken place?     1 2 3  a combustion photosynthesis respiration  b combustion respiration photosynthesis  c photosynthesis combustion respiration  d respiration photosynthesis combustion     31 in the haber process, nitrogen and hydrogen are reacted to make ammonia.    n 2(g)  +  3h 2(g)    2nh 3(g)    the forward reaction is exothermic.    which conditions produce the maximum yield of ammonia?     pressure temperature  a high high  b high low  c low high  d low low      32 which process, used to prevent iron from rusting, involves sacrificial protection?  a alloying  b electroplating  c galvanising  d painting     ",
            "13": "13     \u00a9 ucles 2020 0620/22/m/j/20 [turn over  33 a student suggests three uses of calcium carbonate (limestone).    1 manufacture of cement  2 manufacture of iron  3 treating alkaline soils    which suggestions are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    34 one of the reactions used in the manufacture of sulfuric acid is shown.    2so 2  +  o 2    2so 3    which catalyst is used to increase the rate of this reaction?  a iron  b manganese( iv) oxide  c vanadium( v) oxide  d nickel      35 ethanol is made on an industrial scale by the fermentation of sugars or by the reaction of ethene  with steam in the presence of a suitable catalyst.    what is a disadvantage  of making ethanol from ethene rather than by fermentation?  a a continuous production process is used.  b a non-renewable raw material is used.  c the product is very pure.  d the rate of reaction is very high.     36 which statement about compounds in the same homologous series is correct?  a they have the same chemical properties be cause they have the same number of carbon  atoms.  b they have the same physical properties because they have the same number of carbon  atoms.  c they have different chemical properties because they have different numbers of carbon  atoms.  d they have different physical properties because they have different numbers of carbon  atoms.     ",
            "14": "14  \u00a9 ucles 2020 0620/22/m/j/20  37 increasing the number of atoms in one molecule of a hydrocarbon increases the amount of  energy released when it burns.    what is the correct order?     less energy  released  more energy  released  a ethene ethane methane  b ethene methane ethane  c methane ethane ethene  d methane ethene ethane     38 an organic compound, p, reacts with zinc to produce a gas, q.    what are p and q?     p q  a ethanoic acid carbon dioxide  b ethanoic acid hydrogen  c ethanol carbon dioxide  d ethanol hydrogen     39 alkanes undergo substitution reactions in the presence of uv light.    which equation represents a substitution reaction of ethane?  a c 2h6  +  c l 2  \u2192  c2h4  +  2hc l  b c 2h6  +  c l 2  \u2192  c2h5cl  +  hc l  c c 2h6  +  c l 2  \u2192  c2h4cl 2  +  h 2  d c 2h6  +  hc l  \u2192  c2h5cl  +  h 2     40 which substances are natural polymers?    1 proteins  2 carbohydrates  3 nylon 4 poly(ethene)    a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4     ",
            "15": "15       permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2020 0620/22/m/j/20  blank page",
            "16": "16  \u00a9 ucles 2020 0620/22/m/j/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s20_qp_23.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 06_0620_23/3rp   \u00a9 ucles 2020   [turn ove r   *1657199694*cambridge igcse\u2122       chemistry  0620/23     paper 2 multiple choice (extended)  may/june 2020     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate num ber on the multiple choice answer sheet in the  spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark. a ma rk will not be deducted for a wrong answer.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/23/m/j/20  1 a mixture of ice and water is left to stand and the ice melts.    which row describes what happens as the ice is melting?     temperature of mixture energy changes  a increases average kinetic energy of particles increases  b increases energy is used to overcome attractive forces   c stays the same average kinetic energy of particles increases  d stays the same energy is used to overcome attractive forces       2 which piece of apparatus is used to measure 13.7  cm3 of dilute hydrochloric acid?  a balance  b burette  c conical flask  d pipette     3 chromatography is carried out on a mixture of th ree substances. the chromatogram is sprayed  with a locating agent. the result is shown.    solvent front baseline     what are possible reasons why the chromatogram shows only two spots?    1 one of the substances in the mixture is insoluble in the solvent.  2 the locating agent did not react with one of the substances in the mixture. 3 two of the substances in the mixture have the same r f values.  4 the rf value of one of the substances is too small.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     ",
            "3": "3     \u00a9 ucles 2020 0620/23/m/j/20 [turn over  4 the structure of an atom of element x is shown.    5p 6nkey = electron = neutron = protonnp     what is element x?  a boron  b carbon  c sodium  d sulfur      5 the electronic structures of two atoms, p and q, are shown.    p q     p and q combine together to form a compound.    what is the type of bonding in the compound and what is the formula of the compound?     type of bonding formula  a ionic pq  b ionic pq 2  c covalent pq 2  d covalent pq      6 caesium is a metal in group i of the periodic table.    which description of the bonding in caesium is correct?  a electrostatic attraction between oppositely charged ions  b electrostatic attraction between positive metal ions and mobile electrons  c neighbouring metal atoms sharing pairs of electrons  d strong attractive forces between atoms   ",
            "4": "4  \u00a9 ucles 2020 0620/23/m/j/20  7 why does magnesium oxide, mgo, have a very high melting point?  a there is a very strong double bond between magnesium and oxygen.  b there is a very strong attractive force between the magnesium oxide molecules.  c the oxide ions are strongly attracted to positive ions.  d the magnesium ions are strongly attracted to a sea of electrons.      8 aluminium metal reacts with iron( iii) oxide to form aluminium oxide and iron.    which chemical equation for the reaction between aluminium and iron( iii) oxide is correct?  a feo  +  a l  \u2192  a l o  +  fe  b fe 2o  +  2a l  \u2192  a l 2o  +  2fe  c fe 2o3  +  a l  \u2192  a l 2o3  +  fe  d fe 2o3  +  2a l  \u2192  a l 2o3  +  2fe      9 the haber process is a reversible reaction.    n2(g)  +  3h 2(g)    2nh 3(g)    the reaction has a 30% yield of ammonia.    which volume of ammonia gas, nh 3, measured at room temperature and pressure, is obtained  by reacting 0.75 moles of hydrogen with excess nitrogen?  a 3600  cm3 b 5400  cm3 c 12  000  cm3 d 18  000  cm3    10 which row describes the reactions during the electrolysis of dilute aqueous sodium chloride?     anode (+) reaction cathode (\u2013) reaction  a h2  \u2192  2h+  +  2e\u2013 2h2o  +  o 2  +  4e\u2013  \u2192  4oh\u2013  b 2h+  +  2e\u2013  \u2192  h2 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013  c 2h2o  +  o 2  +  4e\u2013  \u2192  4oh\u2013 h 2  \u2192  2h+  +  2e\u2013  d 4oh\u2013  \u2192  2h 2o  +  o 2  +  4e\u2013 2h+  +  2e\u2013  \u2192  h2     ",
            "5": "5     \u00a9 ucles 2020 0620/23/m/j/20 [turn over  11 the electrolysis of aqueous copper( ii) sulfate, using inert electrodes, is shown.    aqueous copper( ii) sulfate+\u2013     which statement about a reaction at an electrode is correct?  a copper ions gain electrons at the negative electrode.  b copper ions gain electrons at the positive electrode.  c hydrogen ions gain electrons at the negative electrode.  d hydrogen ions gain electrons at the positive electrode.    12 ethene gas, c 2h4, is completely burned in excess oxygen to form carbon dioxide and water.    the equation for this exothermic reaction is shown.    c2h4  +  3o 2  \u2192  2co 2  +  2h 2o    the table shows the bond energies involved in the reaction.    bond bond energy  (kj  / mol)  c=c 614  c\u2013h 413  o=o 495  c=o 799  o\u2013h 467    what is the total energy change in this reaction?  a \u2013954  kj / mol  b \u20131010  kj / mol  c \u20131313  kj / mol  d \u20131369  kj / mol    ",
            "6": "6  \u00a9 ucles 2020 0620/23/m/j/20  13 which statements about hydrogen fuel cells are correct?    1 water is formed as the only waste product.  2 both water and carbon dioxide are formed as waste products.  3 the overall reaction is  2h 2  +  o 2  \u2192  2h 2o.  4 the overall reaction is endothermic.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     14 in which tube is a physical change taking place?    a water iron nailb water sodium chloridec dilute hydrochloric aciddilute hydrochloric acidd calcium carbonatemagnesium       15 a chemical reaction occurs when the reacting particles collide.    which reaction conditions would produce the greatest rate of particle collisions?     concentration  of acid reaction  temperature  a decrease decrease  b no change increase  c increase increase  d increase no change     ",
            "7": "7     \u00a9 ucles 2020 0620/23/m/j/20 [turn over  16 at room temperature, the conversion of nitrogen dioxide, no 2, into dinitrogen tetroxide, n 2o4, is  reversible.    2no 2(g)    n2o4(g)   brown colourless   gas gas   the forward reaction is exothermic.    which changes cause the equilibrium to shift to the left?     pressure temperature  a decrease decrease  b decrease increase  c increase decrease  d increase increase      17 the equation for the reaction between zinc and aqueous copper( ii) sulfate is shown.    zn  +  cuso 4  \u2192  znso 4  +  cu    which statement is correct?  a the oxidation state of the oxidising agent has changed from 0 to +2.  b the oxidation state of the reducing agent has changed from 0 to +2.  c the oxidation state of the reducing agent has changed from +2 to 0.  d this is not a redox reaction. the solu tion changes from colourless to blue.    18 the graph shows how the ph of a solution changes as an acid is added to an alkali.    acid  +  alkali  \u2192  salt  +  water    which letter represents the area of the graph where both acid and salt are present?    pha b c d14 7 0 volume of acid added     ",
            "8": "8  \u00a9 ucles 2020 0620/23/m/j/20  19 which statement describes a weak acid?  a it is a proton acceptor and is fully ionised in aqueous solution.  b it is a proton acceptor and is partially ionised in aqueous solution.  c it is a proton donor and is fully ionised in aqueous solution.  d it is a proton donor and is partially ionised in aqueous solution.      20 the apparatus shown is used to prepare aqueous copper( ii) sulfate.    ysolid x aqueous copper( ii) sulfateexcess of solid xfilter paper heatstirrer     what are x and y?     x y  a copper aqueous iron( ii) sulfate  b copper( ii) chloride dilute sulfuric acid  c copper( ii) oxide dilute sulfuric acid  d sulfur aqueous copper( ii) chloride      21 which two compounds would react together to form the insoluble salt lead( ii) chloride?     compound solubility in water  1 lead( ii) nitrate yes  2 lead( ii) sulfate no  3 silver chloride no  4 sodium chloride yes    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "9": "9     \u00a9 ucles 2020 0620/23/m/j/20 [turn over  22 the elements in group i include lithium, sodium and potassium.    which statements about these elements are correct?    1 sodium is denser than lithium.  2 lithium has a lower melting point than potassium. 3 potassium is a relatively soft metal. 4 sodium is less reactive than lithium but more reactive than potassium.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     23 the properties of the element titanium, ti, can be predicted from its position in the periodic table.    which row identifies the properties of titanium?     can be used  as a catalyst conducts electricity  when solid has low density forms coloured  compounds  a \u0016 \u0016 \u0016 \u001a  b \u0016 \u0016 \u001a \u0016  c \u0016 \u001a \u0016 \u0016  d \u001a \u0016 \u0016 \u0016      24 which statement about the noble gases is correct?  a argon is used in light bulbs and balloons.  b helium reacts with oxygen in the air.  c they all have full outer electron shells.  d they are all diatomic molecules.     25 which property is shown by all metals?  a they are extracted from their ores by heating with carbon.  b they conduct electricity.  c they form acidic oxides.  d they react with hydrochloric acid to form hydrogen.    ",
            "10": "10  \u00a9 ucles 2020 0620/23/m/j/20  26 a salt is heated strongly. the only products are a white solid and a colourless gas.    what is the salt?  a copper( ii) carbonate  b potassium carbonate  c calcium nitrate  d sodium nitrate     27 molten iron from the blast furnace contains impurities.    the process of turning the impure iron into steel involves blowing oxygen into the molten iron and  adding calcium oxide.    what are the reasons for blowing in oxygen and adding calcium oxide?     blowing in oxygen adding calcium oxide  a carbon is removed by reacting with oxygen reacts with acidic impurities making slag  b carbon is removed by reacting with oxyg en reacts with slag and so removes it  c iron reacts with the oxygen reacts with acidic impurities making slag  d iron reacts with the oxygen reacts with slag and so removes it      28 p, q, r and s are four metals.    p displaces q from a solution of its sulfate.    q reacts with hydrochloric acid and can be extracted from its ore using carbon.    r does not react with hydrochloric acid.    the carbonate of s does not decompose when heated strongly.    what is the order of reactivity of the metals, starting with the most reactive?     most  reactive  least  reactive  a r p q s  b r q p s  c s p q r  d s q p r     ",
            "11": "11     \u00a9 ucles 2020 0620/23/m/j/20 [turn over  29 which substances can be used to detect the presence of water?    1 cobalt( ii) chloride  2 copper( ii) sulfate  3 litmus  4 methyl orange    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4    30 which processes increase the amount of carbon dioxide in the atmosphere?    1 burning ethanol  2 farming cattle 3 growing trees    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    31 hydrogen and nitrogen react to form ammonia in the haber process.    n 2  +  3h 2    2nh 3    the forward reaction is exothermic.    which statements about the process are correct?    1 nitrogen is obtained from the air.  2 increasing the temperature of the reaction increases the yield of ammonia. 3 increasing the reaction pressure increases the yield of ammonia.  4 vanadium( v) oxide is used as a catalyst.    a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4    ",
            "12": "12  \u00a9 ucles 2020 0620/23/m/j/20  32 the diagram shows the positions of sacrificial anodes on the steel hull of a yacht.    anodes     which metal is used to make the anodes?  a calcium  b copper  c sodium  d zinc     33 a student suggests three uses of calcium carbonate (limestone).    1 manufacture of cement  2 manufacture of iron  3 treating alkaline soils    which suggestions are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     34 which reaction in the contact pr ocess is catalysed by vanadium( v) oxide?  a s(s)  +  o 2(g)  \u2192  so 2(g)  b 2so 2(g)  +  o 2(g)  \u2192  2so 3(g)  c so 3(g)  +  h 2so 4(l)  \u2192  h2s2o7(l)  d h 2s2o7(l)  +  h 2o(l)  \u2192  2h 2so 4(l)     35 ethanol is produced by:    1 the catalytic addition of steam to ethene  2 fermentation.    which statement is correct?  a both processes require similar amounts of energy.  b both processes use a catalyst.  c process 1 uses a renewable resource.  d process 2 produces the purest ethanol.   ",
            "13": "13     \u00a9 ucles 2020 0620/23/m/j/20 [turn over  36 which statement about a homologous series is correct?  a all members have the same general formula.  b all members have the same molecular formula.  c all members have similar physical properties.  d members show a trend in their chemical properties.      37 increasing the number of atoms in one molecule of a hydrocarbon increases the amount of  energy released when it burns.    what is the correct order?     less energy  released  more energy  released  a ethene ethane methane  b ethene methane ethane  c methane ethane ethene  d methane ethene ethane     38 a small quantity of a solid chemical is added to a large excess of aqueous ethanoic acid.    no bubbles of gas are seen and the solid dissolves to give a colourless solution.    what was the solid chemical?  a calcium hydroxide  b copper( ii) oxide  c magnesium  d sodium carbonate     39 alkanes undergo substitution reactions with chlorine in the presence of ultraviolet light.    which equation shows a reaction of this type?  a c 3h6  +  c l 2  \u2192  c3h6cl 2  b c 3h8  +  c l 2  \u2192  c3h6cl 2  +  h 2  c c 3h8  +  2c l 2  \u2192  c3h6cl 2  +  2hc l  d c 3h6  +  c l 2  \u2192  c3h5cl  +  hc l     ",
            "14": "14  \u00a9 ucles 2020 0620/23/m/j/20  40 which statement about carbohydrates and proteins is correct?  a carbohydrates and proteins are constituents of food.  b carbohydrates and proteins are natural polymers used to make larger molecules called  monomers.  c carbohydrates and proteins are synthetic polymers.  d carbohydrates and proteins cause pollution as they are non-biodegradable.     ",
            "15": "15       permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.   to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.    cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2020 0620/23/m/j/20  blank page",
            "16": "16  \u00a9 ucles 2020 0620/23/m/j/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s20_qp_31.pdf": {
            "1": "*5000877390* chemistry  0620/31 paper 3 theory (core) may/june 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 06_0620_31/2rp \u00a9 ucles 2020 [turn overthis document has 20 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/31/m/j/20 \u00a9 ucles 2020 1 (a)  a list of symbols and formulae is shown. al 3+ ch4 co2 fe3+ n2 no2 o2 o2\u2013 zn2+   answer the following questions about these symbols and formulae.   each symbol or formula may be used once, more than once or not at all.   which symbol or formula represents:  (i)  a compound which contributes to acid rain   ...   [1]  (ii) a compound which is a product of respiration   ...   [1]  (iii)  a gas which forms 21% of clean dry air   ...   [1]  (iv)  an ion which forms a red-brown precipitate when added to aqueous sodium hydroxide   ...   [1]  (v)  an ion formed when an atom gains electrons?   ...   [1]",
            "3": "3 0620/31/m/j/20 \u00a9 ucles 2020 [turn over  (b)  complete the table to show the relative charge and approximate relative mass of a proton, a  neutron and an electron. type of particlerelative chargeapproximate relative mass proton +1 neutron electron1 2000  [3]  (c)  deduce the number of electrons and neutrons in an atom of the isotope of iron shown. 58fe26  number of electrons  ...  number of neutrons  ...  [2]  [total: 10]",
            "4": "4 0620/31/m/j/20 \u00a9 ucles 2020 2\t\ta\tsolution\tis\tobtained\t by\tfiltering\ta\tmixture of soil and water. the table shows the mass of some of  the ions in 1000 cm3 of this solution. name of ion formula of ionmass of ion in 1000 cm3 of soil solution / mg aluminium al 3+0.1 nh4+35.0 calcium ca2+1.3 iron( ii) fe2+47.0 magnesium mg2+0.2 no3\u201323.0 phosphate po43\u20134.2 potassium k+99.0 sulfate so42\u20137.5  (a)  answer these questions using the information in the table.  (i)  which negative ion has the lowest concentration?   ...   [1]  (ii)  state the name of the no3\u2013 ion.   ...   [1]  (iii)  calculate the mass of phosphate ions in 250 cm3 of this solution.  mass = .. mg  [1]  (iv)  name the compound that contains nh4+ ions and po43\u2013 ions.   ...   [1]  (b)  describe a test for potassium ions.  test  .  observations  ..  [2]",
            "5": "5 0620/31/m/j/20 \u00a9 ucles 2020 [turn over  (c)  the names and formulae for some compounds are shown. aluminium phosphate, al po4 calcium phosphate, ca3(po4)2 potassium phosphate, k3po4   deduce the formula for magnesium phosphate.   ..   [1]  [total: 7]",
            "6": "6 0620/31/m/j/20 \u00a9 ucles 2020 3  many compounds and elements have important uses.  (a)  complete the table to show the name, formula and use of each compound and element. name of compound or elementnumber of atoms in the formulaformula use chlorine chlorine = 2 cl 2 carbon = 1 hydrogen = 4ch4 calcium carbonatecalcium = 1 carbon = 1 oxygen = 3  [5]  (b)  the table shows the minimum temperature for the reduction of four metal oxides by carbon. metal oxideminimum temperature for reduction by carbon calcium oxide not reduced at 1530 \u00b0c iron( ii) oxide reduced at 650 \u00b0c titanium oxide reduced at 1530 \u00b0c zinc oxide reduced at 720 \u00b0c   put the four metals in order of their reactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]",
            "7": "7 0620/31/m/j/20 \u00a9 ucles 2020 [turn over  (c)  anhydrous copper( ii) sulfate, cuso4, is used to test for water.  (i)  describe the change in colour when water is added to anhydrous copper( ii) sulfate.  from  to  ...  [2]  (ii)  this reaction is reversible.   describe how this reaction can be reversed.   ...   [1]  (iii)  state one use of water in industry.   ...   [1]  [total: 11]",
            "8": "8 0620/31/m/j/20 \u00a9 ucles 2020 4\t\tthe\tproperties\tof\tfive\talkenes\tat\troom\ttemperature\tare\tshown\tin\tthe\ttable. alkenenumber of carbon atoms in a moleculestate at room temperaturedensity in g / cm3boiling point / \u00b0c ethene 2 gas 0.0012 \u2013104 propene 3 gas 0.0018 \u201347 butene 4 gas 0.0024 pentene 5 liquid 0.64 30 hexene 6 liquid 0.67 63  (a)  answer these questions using only the information in the table.  (i)  predict the boiling point of butene.  .. \u00b0c  [1]  (ii)\t\tdescribe\tthe\tgeneral\ttrend\tin\tthe\tdensity \tof\tthe\talkenes.   ...   [1]  (iii)\t\tsuggest\t why\tthe\tdensities\t of\tthe\tfirst\tthree\talkenes\t are\tmuch\tlower\tthan\tthe\tdensity\tof\t pentene and hexene.   ...   [1]  (b) (i)  complete the chemical equation for the complete combustion of propene.  2c3h6  +  ..o2  \u2192  6co2  +  6h2o [1]  (ii)  describe a test for carbon dioxide.  test  ..  observations  ...  [2]  (iii)  universal indicator is added to an aqueous solution of carbon dioxide.  \u25cf what colour change is observed?  from green to  ..  \u25cf give a reason for your answer.   .   .  [2]",
            "9": "9 0620/31/m/j/20 \u00a9 ucles 2020 [turn over  (c)  when propene undergoes incomplete combustion, carbon monoxide is formed.  (i)  what condition is needed for incomplete combustion?   .   ...   [1]  (ii)  give one adverse effect of carbon monoxide on health.   ...   [1]  [total: 10]",
            "10": "10 0620/31/m/j/20 \u00a9 ucles 2020 5  when concentrated hydrochloric acid is electrolysed, gases are produced at the electrodes.   the incomplete apparatus is shown. concentrate d hydrochloric acid power supply+ \u2013  (a) (i)  complete the diagram by:  \u25cf labelling the anode and cathode  \u25cf showing how the gases are collected.  [2]  (ii)  predict the products of this electrolysis at the:   positive electrode     negative electrode.  .  [2]  (iii)  graphite (carbon) electrodes are used in this electrolysis.   suggest one other element that can be used as an electrode and give a reason, other  than that it can conduct electricity.  element  ...  reason  .  [2]  (b)  hydrogen chloride is produced when chlorine reacts with hydrogen.   complete the chemical equation for this reaction.  cl 2  +  ..  \u2192  .hc l [2]",
            "11": "11 0620/31/m/j/20 \u00a9 ucles 2020 [turn over  (c) aqueous chlorine reacts with aqueous sodium iodide. cl 2  +  2nai  \u2192  i2  +  2nacl  (i)  how does this reaction show that chlorine is more reactive than iodine?   ...   [1]  (ii)  what colour is iodine in aqueous solution?   ...   [1]  [total: 10]",
            "12": "12 0620/31/m/j/20 \u00a9 ucles 2020 6  acids have characteristic properties.  (a)  hydrochloric acid reacts with magnesium.   name the products of this reaction and give the observations.                  ..   [4]  (b)  the rate of reaction of iron( ii) carbonate with hydrochloric acid can be determined by measuring  the\ttime\ttaken\tto\tproduce\t20\t cm3 of carbon dioxide. \t \ta\tstudent\tmeasured\t the\ttime\ttaken\tto\tproduce\t 20\tcm3 of carbon dioxide at three different  temperatures.   in each experiment the student used:  \u25cf 1 g of large pieces of iron( ii) carbonate  \u25cf dilute hydrochloric acid of the same concentration and volume.   the results are shown in the table. temperature / \u00b0ctime / s 20 38 25 30 30 19  (i)  use the information in the table to describe how the rate of reaction changes with  temperature.   ...   [1]",
            "13": "13 0620/31/m/j/20 \u00a9 ucles 2020 [turn over  (ii)  describe the effect of each of the following on the rate of this reaction at constant  temperature.  \u25cf smaller pieces of iron( ii) carbonate are used.   all other conditions stay the same.   .  \u25cf the concentration of hydrochloric acid is decreased.   all other conditions stay the same.   .  [2]  (c)  the reaction of iron( ii) carbonate with hydrochloric acid is exothermic.   what is meant by the term exothermic ?   ..   [1]  (d)  rust contains compounds of iron.   state two conditions needed for iron to rust.      ..   [2]  (e)  iron and magnesium are both used in alloys.   which one of these diagrams, a, b, c or d, best represents an alloy? a b c d   ..   [1]  [total: 11]",
            "14": "14 0620/31/m/j/20 \u00a9 ucles 2020 7  the structure of myrcene is shown. cchh hhh cc hhh h hc cc cch h c h hh h  (a)  deduce the formula of myrcene to show the number of atoms of carbon and hydrogen.   ..   [1]  (b)  myrcene is found in some plants.   the coloured compounds in plant leaves can be separated by chromatography.   complete the diagram by putting the correct labels in the boxes. beakerlid  . .  .  [2]  (c)  myrcene is an unsaturated hydrocarbon.   describe a chemical test to distinguish between a saturated and an unsaturated hydrocarbon.  test  .  observations with saturated hydrocarbon  ..     observations with unsaturated hydrocarbon  ..     [3]",
            "15": "15 0620/31/m/j/20 \u00a9 ucles 2020 [turn over  (d)  butane is a saturated hydrocarbon.   to which homologous series does butane belong?   draw a circle around the correct answer.  alcohol          alkane          alkene          carboxylic acid  [1]  (e)\t\tlarge\thydrocarbons\tcan\tbe\tcracked\tto\tform\tsmaller \thydrocarbons. \t \tcomplete\t the\tchemical\t equation\t for\tcracking\t tridecane,\t c13h28,\tto\tform\tan\talkene\tand\tone\t other hydrocarbon.  c13h28  \u2192  c3h6  +  .. [1]  (f)\t\tethene\tis\tan\talkene.   draw the structure of ethene showing all of the atoms and all of the bonds.  [1]  (g)  complete the sentences about the separation of hydrocarbons from petroleum using words  from the list.  bitumen combustion condense crystallisation distillation  evaporate gasoline kerosene melt   hydrocarbons are separated in a fractionating column by fractional ... .       hydrocarbons with lower boiling points move further up the column. when the temperature     in the column falls below the boiling points of the hydrocarbons they ... . the     fraction\tat\tthe\tbottom\tof\tthe\tcolumn\twhich\tis\tused\tfor\tmaking\troads\tis\tcalled\t...\t .  [3]  [total: 12]",
            "16": "16 0620/31/m/j/20 \u00a9 ucles 2020 8  the diagram shows part of the structures of sodium bromide and sulfur. na+br \u2013na+br \u2013 br \u2013na+br \u2013na+ na+br \u2013na+br \u2013 br \u2013na+br \u2013na+sodium bromide sulfur  (a)  describe both sodium bromide and sulfur in terms of:  \u25cf bonding              \u25cf electrical conductivity        \u25cf solubility in water.        [5]  (b)  sulfur is an element.   what is meant by the term element  ?      ..   [1]",
            "17": "17 0620/31/m/j/20 \u00a9 ucles 2020 [turn over  (c)  sodium can be extracted from sodium bromide by electrolysis.   sodium is a metal in group i of the periodic table.  (i)  describe one chemical property of sodium.   ...   [1]  (ii)  which two of these statements about the physical properties of sodium are correct? \t \ttick\ttwo boxes.   sodium is very hard.   sodium has a high density.   sodium conducts electricity.   sodium is malleable.   sodium does not conduct heat.  [2]  [total: 9]",
            "18": "18 0620/31/m/j/20 \u00a9 ucles 2020blank page",
            "19": "19 0620/31/m/j/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/31/m/j/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s20_qp_32.pdf": {
            "1": "*4918803397* chemistry  0620/32 paper 3 theory (core) may/june 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 06_0620_32/3rp \u00a9 ucles 2020 [turn overthis document has 20 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/32/m/j/20 \u00a9 ucles 2020 1 (a)  a list of symbols and formulae is shown. ch4 cl \u2013 co2 cr3+ cu2+ fe2+ h2 k+ n2 o2 so2   answer the following questions about these symbols and formulae.   each symbol or formula may be used once, more than once or not at all.   which symbol or formula represents:  (i)  a compound produced by the thermal decomposition of calcium carbonate    ...   [1]  (ii)  an element which is used as a fuel   ...   [1]  (iii)  a gas which forms 78% of clean dry air   ...   [1]  (iv)  an ion which forms a blue precipitate when added to aqueous sodium hydroxide   ...   [1]  (v)  an ion formed when an atom gains an electron?   ...   [1]",
            "3": "3 0620/32/m/j/20 \u00a9 ucles 2020 [turn over  (b)  complete the table to show the relative charge and approximate relative mass of a proton, a  neutron and an electron. type of particlerelative chargeapproximate relative mass proton 1 neutron electron \u20131  [3]  (c) deduce the number of electrons and neutrons in an atom of the isotope of potassium shown. 41k19   number of electrons  ...  number of neutrons  ...  [2]  [total: 10]",
            "4": "4 0620/32/m/j/20 \u00a9 ucles 2020 2\t\ta\tsolution\tis\tobtained\t by\tfiltering\ta\tmixture\tof\tsoil\tand\twater.\tthe\ttable\tshows\tthe\tmass\tof\tsome\tof\t the ions in 1000 cm3 of this solution. name of ion formula of ionmass of ion in 1000 cm3 of soil solution / mg aluminium al 3+0.2 nh4+22.0 calcium ca2+0.2 iron( ii) fe2+79.0 magnesium mg2+0.1 nitrate no3\u201328.0 phosphate po43\u201314.0 potassium k+39.0 so42\u20135.1  (a)  answer these questions using the information in the table.  (i)  which negative ion has the lowest concentration?   ...   [1]  (ii)  state the name of the so42\u2013 ion.   ...   [1]  (iii)  calculate the mass of nitrate ions in 200  cm3 of this solution.  mass = .. mg  [1]  (iv)  name the compound that contains nh4+ ions and no3\u2013 ions.   ...   [1]  (b)  describe a chemical test for calcium ions.  test  .  observations  ..  [2]",
            "5": "5 0620/32/m/j/20 \u00a9 ucles 2020 [turn over  (c)  the names and formulae for some compounds are shown. aluminium nitrate, al (no3)3 magnesium nitrate, mg(no3)2 sodium nitrate, nano3   deduce the formula for calcium nitrate.   ..   [1]  [total: 7]",
            "6": "6 0620/32/m/j/20 \u00a9 ucles 2020 3  many compounds have important uses.  (a)  complete the table to show the name, number of atoms in the formula and use. name of compoundnumber of atoms in the formulaformula use waterhydrogen = 2 oxygen = 1h2o sulfur = 1 oxygen = 2so2 calcium hydroxide (slaked lime)calcium =  oxygen =  hydrogen = ca(oh)2  [5]  (b)  the table compares the reactions of four metals with steam. metal reaction with steam copper does not react magnesium reacts rapidly sodium reacts explosively zinc reacts slowly when warmed   put the four metals in order of their reactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]  (c)  sodium reacts with molten sodium hydroxide.   complete the chemical equation for this reaction.  2na  +  ..naoh  \u2192  ..na2o  +  h2 [2]  [total: 9]",
            "7": "7 0620/32/m/j/20 \u00a9 ucles 2020 [turn over 4\t\tthe\tproperties\tof\tthe\tfirst\tfour\tgroup\ti\telements\tare\tshown\tin\tthe\ttable. elementdensity in g / cm3melting point / \u00b0cboiling point / \u00b0c lithium 0.53 181 1342 sodium 0.97 98 883 potassium 0.86 63 760 rubidium 39 686  (a)  answer these questions using only the information in the table.  (i)\t\tdescribe\tthe\tgeneral\ttrend\tin\tthe\tboiling \tpoints\tof\tthe\tgroup\ti\telements.   ...   [1]  (ii)\t\texplain\twhy\tit\tis\tdifficult\tto\tpredict\tthe\tdensity\tof\trubidium.   .   ...   [1]  (iii)  deduce the state of rubidium at 45 \u00b0c. explain your answer.   .   .  [2]  (b)  when sodium reacts with carboxylic acids, hydrogen is produced.  (i)  describe a test for hydrogen.  test  ..  observations  ...  [2]  (ii)  the structure of a carboxylic acid is shown. c ohch hch hch hch hho   deduce the formula of this carboxylic acid to show the number of atoms of carbon,  hydrogen and oxygen.   ...   [1]",
            "8": "8 0620/32/m/j/20 \u00a9 ucles 2020  (c)  universal indicator is added to an aqueous solution of sodium oxide.  \u25cf what colour change is observed?  from green to  .  \u25cf\tgive\ta\treason\tfor\tyour\tanswer.        [2]  [total: 9]",
            "9": "9 0620/32/m/j/20 \u00a9 ucles 2020 [turn over 5  molten magnesium bromide is electrolysed.   the incomplete apparatus is shown. + \u2013  (a) (i)  complete the diagram by:  \u25cf labelling the anode and cathode  \u25cf adding the power supply and connecting wires.  [2]  (ii)  predict the products of this electrolysis at the:  positive electrode    negative electrode.  .  [2]  (b)  the electrodes must be able to conduct electricity.  (i)\t\tgive\tone other property that the electrodes must have.   ...   [1]  (ii)  name a suitable element that can be used as an electrode.   ...   [1]",
            "10": "10 0620/32/m/j/20 \u00a9 ucles 2020  (c)  aqueous chlorine reacts with aqueous magnesium bromide. cl 2  +  mgbr2  \u2192  br2  +  mgcl 2  (i)  how does this reaction show that chlorine is more reactive than bromine?   ...   [1]  (ii)  what colour is bromine in aqueous solution?   ...   [1]  (d)  complete the chemical equation for the reaction of chlorine with phosphorus.  ..c l 2  +  2p  \u2192  ..pc l 5 [2]  [total: 10]",
            "11": "11 0620/32/m/j/20 \u00a9 ucles 2020 [turn over 6  acids have characteristic properties.  (a)  hydrochloric acid reacts with magnesium carbonate.   name the products of this reaction and give the observations.               ..   [4]  (b)  the rate of reaction of iron with sulfuric acid can be determined by measuring the time taken  to produce 20 cm3 of hydrogen.   a student measured the time taken to produce 20 cm3 of hydrogen using three different  concentrations of sulfuric acid. \t \tin\teach\texperiment\tthe\tstudent\tused:  \u25cf 1 g of iron powder  \u25cf the same temperature  \u25cf the same volume of sulfuric acid.   the results are shown in the table. concentration of acid in mol / dm3time / s 0.1 33 0.2 17 0.5 8  (i)  use the information in the table to describe how the rate of reaction changes with the  concentration of sulfuric acid.   ...   [1]",
            "12": "12 0620/32/m/j/20 \u00a9 ucles 2020  (ii)  describe the effect of each of the following on the rate of this reaction with 0.5 mol / dm3 of  sulfuric acid.  \u25cf larger pieces of iron are used.   all other conditions stay the same.   .  \u25cf the temperature is increased.   all other conditions stay the same.   .  [2]  (c)  heat is given out when iron reacts with sulfuric acid.   what term describes a reaction which gives out heat?   ..   [1]  (d)  the reaction of iron with steam is shown. 3fe  +  4h2o  \u2192  fe3o4  +  4h2   how does this equation show that iron gets oxidised?      ..   [1]  (e)  rust contains hydrated iron( iii) oxide.   describe and explain one method of preventing iron from rusting.      ..   [2]  [total: 11]",
            "13": "13 0620/32/m/j/20 \u00a9 ucles 2020 [turn over 7  the structure of nerol is shown. cchhh cc hhh hc chh h h hc cchh ohchhh  (a)  draw a circle around the alcohol functional group on the structure of nerol. [1]  (b)  what feature of the nerol molecule shows that it is an unsaturated compound?   ..   [1]  (c)  nerol can be extracted from some plants.   crushed plant leaves containing nerol are mixed with an organic solvent called octane.   nerol dissolves in octane.  (i)  describe how you would separate the crushed plant leaves from the solution of nerol in  octane.    ...   [1]  (ii)  the boiling point of nerol is 224 \u00b0c.   the boiling point of octane is 126 \u00b0c.   explain how distillation separates nerol from the octane.   .   .   .   ...   [2]",
            "14": "14 0620/32/m/j/20 \u00a9 ucles 2020  (d)  the mixture of coloured compounds in plant leaves can be separated by chromatography.   the apparatus is shown. chromatography paperlid   on the diagram:  \u25cf draw an \u2018x\u2019 to show where the mixture of coloured compounds is placed at the start of the  experiment   \u25cf draw a line to show the level of the solvent at the start of the experiment.  [2]  (e)  ethanol is a solvent.  (i)  draw the structure of ethanol to show all of the atoms and all of the bonds.  [2]  (ii)  complete the sentences about the manufacture of ethanol using words from the list.  catalyst hydrocarbon hydrogen  oxygen plastic steam   ethanol is manufactured by the reaction of ethene with .. . the rate of    this reaction is increased by the use of a .. .   [2]",
            "15": "15 0620/32/m/j/20 \u00a9 ucles 2020 [turn over  (f)  ethene and propene are in the same homologous series of organic compounds.   which two statements about ethene and propene are correct.   tick two boxes.   they have the same physical properties.   they have the same number of carbon atoms.   they have similar chemical properties.   they have the same number of hydrogen atoms.   they have the same functional group.  [2]  [total: 13]",
            "16": "16 0620/32/m/j/20 \u00a9 ucles 2020 8  the diagram shows part of the structures of caesium chloride and carbon dioxide. caesium chloride carbon dioxide cl \u2013 cs+ cl \u2013 cs+cl \u2013 cs+cl \u2013 cs+cl \u2013 cs+ cl \u2013 cs+ocoo c ooco o c o  (a)  describe both caesium chloride and carbon dioxide in terms of:  \u25cf bonding              \u25cf solubility in water        \u25cf arrangement of particles.        [5]  (b)  caesium oxide is a compound.   what is meant by the term compound  ?      ..   [1]  (c)  explain why caesium is not extracted from caesium oxide by heating with carbon.   ..   [1]",
            "17": "17 0620/32/m/j/20 \u00a9 ucles 2020 [turn over  (d)  caesium is a metal.   describe two properties that are characteristic of most metals.  1  .  2  .  [2]  (e)  carbon dioxide is a gas.  (i)  which one of these processes does not produce carbon dioxide?   tick one box.   the reaction of hydrochloric acid with calcium carbonate   respiration in animals and plants   the reaction of hydrochloric acid with magnesium   the thermal decomposition of calcium carbonate  [1]  (ii)  carbon dioxide is a greenhouse gas. \t \tgive\t one effect of an increase in the concentration of greenhouse gases in the atmosphere.   ...   [1]  [total: 11]",
            "18": "18 0620/32/m/j/20 \u00a9 ucles 2020blank page",
            "19": "19 0620/32/m/j/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/32/m/j/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s20_qp_41.pdf": {
            "1": "*2337870270* chemistry  0620/41 paper 4 theory (extended) may/june 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 06_0620_41/5rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/41/m/j/20 \u00a9 ucles 2020 1  this question is about elements x, y and z.  (a)  an atom of element x is represented as 34x16.  (i)  name the different types of particles found in the nucleus of this atom of x.   .   ...   [2]  (ii)  what is the term for the total number of particles in the nucleus of an atom?   ...   [1]  (iii)  what is the total number of particles in the nucleus of an atom of 34x16?   ...   [1]  (iv)  what is the electronic structure of the ion x2\u2013?   ...   [1]  (v)  suggest the formula of the compound formed between aluminium and x.   ...   [1]  (b) (i)  what term is used to describe atoms of the same element with different numbers of  particles in the nucleus?   ...   [1]  (ii)  identify the atom against which the relative masses of all other atoms are compared.   ...   [1]  (iii)  what is the name of the amount of any substance that contains 6.02 \u00d7 1023 particles?   ...   [1]  (iv)  the constant 6.02 \u00d7 1023 has a name.   what is the name of this constant?   ...   [1]",
            "3": "3 0620/41/m/j/20 \u00a9 ucles 2020 [turn over  (c)\t\tpart\tof\tthe\tdefinition\t of\trelative\tatomic\tmass\tis\t\u2018the\taverage\t mass\tof\tnaturally\t occurring\t atoms\t of an element\u2019.   some relative atomic masses are not whole numbers.   element y has only two different types of atom, 69y and 71y.   the ratio of atoms present in element y is shown. 69y : 71y = 3 : 2  \u25cf calculate the relative atomic mass of element y to one decimal place.  relative atomic mass = ..  \u25cf identify element y.   .  [3]  (d)  element z is in period 3 and group v.  (i)  identify element z.   ...   [1]  (ii)  explain in terms of electron transfer why z behaves chemically as a non-metal.   .   ...   [2]  [total: 16]",
            "4": "4 0620/41/m/j/20 \u00a9 ucles 2020 2  magnesium is a metal.  (a)  name and describe the bonding in magnesium.  name  ..  description of bonding  ...        [4]  (b)  magnesium oxide, mgo, is formed when magnesium burns in oxygen.  (i)  complete the dot-and-cross diagram to show the electron arrangement of the ions in  magnesium oxide.   the inner shells have been drawn.   give the charges on the ions. mg. o.  [3]  (ii)  write the chemical equation for the reaction that occurs when magnesium burns in oxygen.   ...   [2]  (c)  magnesium oxide also forms when magnesium nitrate, mg(no3)2, is heated strongly. this is an  endothermic reaction.  (i)  write the chemical equation for this reaction.   ...   [2]  (ii)  what type of reaction is this?   ...   [1]  (iii)  name two other compounds of magnesium that form magnesium oxide when heated.   .   ...   [2]  [total: 14]",
            "5": "5 0620/41/m/j/20 \u00a9 ucles 2020 [turn over 3  sulfur dioxide, so2, is used in the manufacture of sulfuric acid.  (a)\t\tin\tthe\tfirst\tstage\tof\tthe\tprocess,\tsulfur\tdioxide\tis\tobtained\tfrom\tsulfur-containing\tores.   name one of these ores.   ..   [1]  (b)  the next stage of the process is a reaction which can reach equilibrium.   the equation for this stage is shown. 2so2(g)  +  o2(g)    2so3(g)  (i)  describe two features of an equilibrium.   .   ...   [2]  (ii)  name the catalyst used in this stage.   ...   [1]  (iii)  why is a catalyst used?   ...   [1]  (iv)  explain, in terms of particles, why a high temperature increases the rate of this reaction.   .   .   .   .   ...   [3]  (v)  in this stage, only a moderate temperature of 450 \u00b0c is used.   what does this suggest about the forward reaction?   ...   [1]  (vi)  calculate the percentage by mass of sulfur in sulfur trioxide, so3.  percentage = ..  [2] ",
            "6": "6 0620/41/m/j/20 \u00a9 ucles 2020  (c)  concentrated sulfuric acid is a dehydrating agent which can chemically remove water from  substances.   both hydrated copper( ii) sulfate crystals and sucrose (a sugar), c12h22o11, can be completely  dehydrated by concentrated sulfuric acid.   name the solid product formed in each case.   hydrated copper( ii) sulfate crystals  ...  sucrose  ..  [2]  (d)  when propan-1-ol is heated with concentrated sulfuric acid as a catalyst an unsaturated  hydrocarbon of relative molecular mass 42 is formed and one other product.  (i)  what is meant by the term unsaturated  ?   ...   [1]  (ii)  write the chemical equation for this reaction.   ...   [2]  (iii)  name the unsaturated hydrocarbon formed.   ...   [1]  [total: 17]",
            "7": "7 0620/41/m/j/20 \u00a9 ucles 2020 [turn over 4  this question is about reactions of bases and acids.  (a)  ammonia is a gas at room temperature.   what is the test for ammonia gas? describe the positive result of this test.   test  .   result  ..  [2]  (b)  ammonia reacts with water to form ions. nh3  +  h2o    nh4+  +  oh\u2013  (i)  how does this equation show that ammonia, nh3, behaves as a base?   ...   [1]  (ii)  aqueous ammonia is described as a weak base.  suggest the ph of aqueous ammonia.  ph = ..  [1]  (iii)  describe what is seen when aqueous ammonia is added to aqueous copper( ii) sulfate,  until no further change is seen.   .   .   ...   [3]",
            "8": "8 0620/41/m/j/20 \u00a9 ucles 2020  (c)  aqueous sodium hydroxide, naoh(aq), is a strong alkali that reacts with dilute sulfuric acid  exothermically.  (i)  what type of reaction is this?   ...   [1]  (ii)  complete the equation for the reaction between aqueous sodium hydroxide and dilute  sulfuric acid. 2naoh  +  h2so4  \u2192  .  +  .  [2]  (d)\t\ta\tstudent\twanted\tto\tfind\tthe\tconcentration\t of\tsome\tdilute\tsulfuric\tacid\tby\ttitration.\t the\tstudent\t found that 25.0 cm3 of 0.0400 mol / dm3 naoh(aq) reacted exactly with 20.0 cm3 of h2so4(aq).  (i)  name a suitable indicator to use in this titration.   ...   [1]  (ii)  calculate the concentration of the h2so4(aq) in mol / dm3 using the following steps.  \u25cf calculate the number of moles of naoh in 25.0 cm3.  moles = ..  \u25cf deduce the number of moles of h2so4 that reacted with the 25.0 cm3 of naoh(aq).  moles = ..  \u25cf calculate the concentration of h2so4(aq) in mol / dm3.  concentration = .. mol / dm3  [3]  (iii)  calculate the concentration of the 0.0400 mol / dm3 naoh(aq) in g / dm3.  concentration = .. g / dm3  [2]  [total: 16]",
            "9": "9 0620/41/m/j/20 \u00a9 ucles 2020 [turn over 5  ethanol is manufactured by two different processes.  (a)  for each process, name the organic reactant and state the type of reaction.   organic reactant ...  type of reaction  ..   organic reactant ...  type of reaction  ..  [4]  (b)  alcohols can be oxidised to form carboxylic acids.   name a suitable oxidising agent for this reaction.   ..   [1]  (c)  alcohols can be partially oxidised to form aldehydes.   aldehydes are a homologous series of organic compounds.   partial oxidation is achieved by reacting an alcohol with the oxidising agent in distillation  apparatus as shown. heatthermometer distillatea round-bottomed flask  (i)  name apparatus a.   ...   [1]  (ii)  on the diagram, use one arrow to show where water enters apparatus a. [1]",
            "10": "10 0620/41/m/j/20 \u00a9 ucles 2020  (d)  the table shows some information about aldehydes.  (i)  complete the table. nameethanal propanal butanal molecular formula ch2o c2h4o c3h6o  [2]  (ii)  deduce the general formula of aldehydes.   ...   [1]  (e)  the structural formula of ethanal is shown. chco hh h   the c=o group in aldehydes is at the end of the carbon chain.   this is a reactive part of the molecule.  (i)  what is the name given to the reactive part of any organic molecule?   ...   [1]  (ii)  complete the dot-and-cross diagram to show the electron arrangement of a molecule of  ethanal. inner shells have been drawn. ccoh hhh  [3]",
            "11": "11 0620/41/m/j/20 \u00a9 ucles 2020permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (f)  propanone belongs to a homologous series called ketones. ketones have the same c=o  group as aldehydes but the c=o group is not at the end of the carbon chain. propanone has  the same molecular formula as propanal, c3h6o.  (i)  what term is used to describe molecules with different structures but with the same  molecular formula?   ...   [1]  (ii)  suggest the structure of propanone, c3h6o. show all of the atoms and all of the bonds.  [2]  [total: 17]",
            "12": "12 0620/41/m/j/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s20_qp_42.pdf": {
            "1": "*7336615318* chemistry  0620/42 paper 4 theory (extended) may/june 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 06_0620_42/4rp \u00a9 ucles 2020 [turn overthis document has 16 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/42/m/j/20 \u00a9 ucles 2020 1 (a)  give the name of the process that:  (i)  occurs when a gas turns into a liquid   ...   [1]  (ii)\t\toccurs\twhen\ta\tsolid\tturns\tinto\ta\tgas\twithout\tfirst\tforming\ta\tliquid   ...   [1]  (iii)  is used to separate a mixture of liquids with different boiling points   ...   [1]  (iv)  is used to extract aluminium from aluminium oxide   ...   [1]  (v)  is used to separate a mixture of amino acids.   ...   [1]  (b)  the symbols of the elements in period 2 of the periodic table are shown. li    be    b    c    n    o    f    ne   for each of the following, give the symbol of an element from period 2 which matches the  description.   each element may be used once, more than once or not at all.   which element:  (i)  combines with hydrogen to produce ammonia   ...   [1]  (ii)  makes up approximately 21% of clean, dry air   ...   [1]  (iii)  has atoms with only two electrons in the outer shell   ...   [1]  (iv)  has atoms with only seven protons   ...   [1]  (v)  is a monoatomic gas   ...   [1]  (vi)  is a soft metal stored in oil?   ...   [1]  [total: 11]",
            "3": "3 0620/42/m/j/20 \u00a9 ucles 2020 [turn over 2  fluorine forms both ionic and covalent compounds.  (a)\t\tmagnesium\treacts\twith\tfluorine\tto\tform\tthe\tionic\tcompound\tmagnesium\tfluoride. \t \tthe\telectronic\tstructures\tof\tan\tatom\tof\tmagnesium\tand\tan\tatom\tof\tfluorine\tare\tshown. mg f  (i)  complete the dot-and-cross diagrams to show the electronic structures of one magnesium  ion\tand\tone\tfluoride\tion.\tshow\tthe\tcharges\ton\tthe\tions. mg f .  .  [3]  (ii)\t\twhat\tis\tthe\tformula\tof\tmagnesium\tfluoride?   ...   [1]  (iii)\t\tmagnesium \tfluoride\tdoes\t not conduct electricity when it is solid. \t \twhat\tcan\tbe\tdone\tto\tsolid\tmagnesium\tfluoride\tto\tmake\tit\tconduct\telectricity? \t \tin\tyour\tanswer\texplain\twhy\tmagnesium \tfluoride\tconducts\t electricity\t when\tthis\tchange\tis\t made.   .   .   .   ...   [2]",
            "4": "4 0620/42/m/j/20 \u00a9 ucles 2020  (b)\t\tcarbonyl\t fluoride,\t cof2,\tis\ta\tcovalent\t compound.\t the\tstructure\t of\ta\tmolecule\t of\tcof2 is  shown. c of f   complete the dot-and-cross diagram to show the electron arrangement in a molecule of  carbonyl\tfluoride.\tshow\touter\tshell\telectrons\tonly. c of f  [3]  (c)\t\tthe\tmelting\tpoints\tof\tmagnesium\tfluoride\tand\tcarbonyl\tfluoride\tare\tshown. melting point / \u00b0c magnesium\tfluoride 1263 carbonyl\tfluoride \u2013111  (i)\t\texplain,\t using\tyour\tknowledge\t of\tstructure\t and\tbonding,\t why\tmagnesium\t fluoride\thas\ta\t high melting point.   .   .   .   ...   [2]  (ii)\t\texplain,\t using\tyour\tknowledge\t of\tstructure\t and\tbonding,\t why\tcarbonyl\t fluoride\thas\ta\tlow\t melting point.   .   .   .   ...   [2]  [total: 13]",
            "5": "5 0620/42/m/j/20 \u00a9 ucles 2020 [turn over 3 (a)\t \tsulfuric\tacid\tis\tmade\tfrom\tsulfur\tin\ta\tfour-stage\tprocess.  stage 1\t \tsulfur\tis\tconverted\tinto\tsulfur\tdioxide.  stage 2\t \tsulfur\tdioxide\tis\tconverted\tinto\tsulfur\ttrioxide.  stage 3\t \tsulfur\ttrioxide\tis\tconverted\tinto\toleum.  stage 4\t \toleum\tis\tconverted\tinto\tsulfuric\tacid.  (i)  how is sulfur converted into sulfur dioxide in stage 1?   ...   [1]  (ii)  describe how sulfur dioxide is converted into sulfur trioxide in stage 2.   your answer should include:  \u25cf an equation for the reaction  \u25cf the temperature used  \u25cf the name of the catalyst used.   .   .   .   ...   [3]  (iii)  the reaction in stage 2 can reach equilibrium.   what is meant by the term equilibrium ?   .   .   ...   [2]  (b)\t\tsulfur\ttrioxide\tis\tconverted\tinto\toleum,\th2s2o7, in stage 3.   what is sulfur trioxide reacted with to convert it into oleum?   ..   [1]  (c)\t\toleum\tis\tconverted\tinto\tsulfuric\tacid\tin\t stage 4.   write a chemical equation for the conversion of oleum, h2s2o7, into sulfuric acid.   ..   [2]",
            "6": "6 0620/42/m/j/20 \u00a9 ucles 2020  (d)  when copper is reacted with hot concentrated sulfuric acid, sulfur dioxide gas is formed.   balance the chemical equation for this reaction.  cu  +  ...h2so4  \u2192\t\tcuso4\t\t+\t\tso2  +  ...h2o\t [1]  (e)\t\tsulfur\tdioxide\tis\ta\treducing\tagent. \t \tgive\tthe\tcolour\tchange\tthat\toccurs\twhen\texcess\tsulfur\tdioxide\tis\tbubbled\tinto\tacidified\t aqueous\t potassium manganate( vii).   starting colour of the solution  . \t \tfinal\tcolour\tof\tthe\tsolution\t  ..  [1]  (f)  when sulfuric acid reacts with ammonia the salt produced is ammonium sulfate.   write the chemical equation for this reaction.   ..   [2]  (g)  barium sulfate is an insoluble salt.   barium sulfate can be made from aqueous ammonium sulfate using a precipitation reaction.  (i)  name a solution that can be added to aqueous ammonium sulfate to produce a precipitate  of barium sulfate.   ...   [1]  (ii)  write an ionic equation for this precipitation reaction. include state symbols.   ...   [2]  [total: 16]",
            "7": "7 0620/42/m/j/20 \u00a9 ucles 2020 [turn over 4\t\toxygen\t is\tproduced\t by\tthe\tdecomposition\t of\thydrogen\t peroxide.\t manganese( iv) oxide is the  catalyst for this reaction.  (a)  what is meant by the term catalyst ?         ..   [2]  (b)  a student measures the volume of oxygen produced at regular time intervals using the  apparatus shown. large lumps of manganese( iv) oxide are used. aqueous hydrogen peroxidegas syringe manganese( iv) oxide catalyst   a graph of the results is shown. volum e of oxygen produced / cm3 time  / s00   what happens to the rate of this reaction as time increases?   in your answer, explain why the rate changes in this way.               ..   [4]  (c)  the experiment is repeated using the same mass of manganese( iv) oxide. powdered  manganese( iv) oxide is used instead of large lumps. all other conditions stay the same. \t \tsketch\ta\tgraph\ton\tthe\taxes\tin\t (b) to show how the volume of oxygen changes with time. [2]",
            "8": "8 0620/42/m/j/20 \u00a9 ucles 2020  (d)  in terms of particles, explain what happens to the rate of this reaction when the temperature is  increased.               ..   [3]  (e)  the equation for the decomposition of hydrogen peroxide is shown. 2h2o2(aq)  \u2192  2h2o(l)\t\t+\t\to2(g)   25.0 cm3 of aqueous hydrogen peroxide forms 48.0 cm3 of oxygen at room temperature and  pressure (r.t.p.).   calculate the concentration of aqueous hydrogen peroxide at the start of the experiment using  the following steps.  \u25cf calculate the number of moles of oxygen formed.  .. mol  \u25cf deduce the number of moles of hydrogen peroxide that decomposed.  .. mol  \u25cf calculate the concentration of hydrogen peroxide in mol / dm3.  .. mol / dm3  [3]  (f)\t\toxygen\tcan\talso\tbe\tproduced\tby\tthe\tdecomposition\tof\tpotassium\tchlorate( v), kcl\to3.   the only products of this decomposition are potassium chloride and oxygen.   write a chemical equation for this decomposition.   ..   [2]  [total: 16]",
            "9": "9 0620/42/m/j/20 \u00a9 ucles 2020 [turn over 5  electrolysis of concentrated aqueous sodium chloride using inert electrodes forms chlorine,  hydrogen and sodium hydroxide.  (a)  what is meant by the term electrolysis ?         ..   [2]  (b)  name a substance that can be used as the inert electrodes.   ..   [1]  (c)  write an ionic half-equation for the formation of hydrogen during this electrolysis.   ..   [1]  (d)  give the formulae of the four ions present in concentrated aqueous sodium chloride.   ..   [2]  (e)  explain how sodium hydroxide is formed during this electrolysis.         ..   [2]  [total: 8]",
            "10": "10 0620/42/m/j/20 \u00a9 ucles 2020 6 (a)  propane reacts with chlorine in a photochemical reaction as shown. c3h8  +  c l 2  \u2192  c3h7cl  +  hcl  (i)  what type of reaction is this?   ...   [1]  (ii)  what condition is needed for this photochemical reaction to occur?   ...   [1]  (iii)  draw two structural isomers of compounds with the formula c3h7cl. \t \tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [2]  (b)  propene reacts with chlorine in an addition reaction as shown. c3h6  +  c l 2  \u2192  c3h6cl 2  (i)\t\tstate\twhy\tthis\tis\tan\taddition\treaction.   ...   [1]",
            "11": "11 0620/42/m/j/20 \u00a9 ucles 2020 [turn over  (ii)  the structures of the reactants and products of this reaction are shown. hch hc hh cc lclh + \u2192 hhch hclclch ch \t \tsome\tbond\tenergies\tare\tshown\tin\tthe\ttable. bondbond energy in kj / mol c\u2013c 347 c=c 612 c\u2013h 413 c\u2013cl 339 cl \u2013cl 242   calculate the energy change for the reaction between propene and chlorine using the  following steps.  \u25cf calculate the energy needed to break the bonds.  .. kj   \u25cf calculate the energy released when bonds are formed.  .. kj  \u25cf calculate the energy change for the reaction between propene and chlorine.  .. kj / mol  [3]",
            "12": "12 0620/42/m/j/20 \u00a9 ucles 2020  (c)  there are three functional groups in compound a. ccooh hccompound  a ch2oh h  (i)  name the homologous series of compounds that contains the following structures.  c=c   \t \u2013oh\t  \t \u2013cooh\t ...  [3]  (ii)  what would you observe when compound a is added to:   aqueous bromine     aqueous sodium carbonate?  ..  [2]  (d)  compound a can be used as a single monomer to produce two different polymers.  (i)  draw one repeat unit of the addition polymer formed from compound a.  [2]  (ii)  what type of condensation polymer is formed from compound a?   ...   [1]  [total: 16]",
            "13": "13 0620/42/m/j/20 \u00a9 ucles 2020blank page",
            "14": "14 0620/42/m/j/20 \u00a9 ucles 2020blank page",
            "15": "15 0620/42/m/j/20 \u00a9 ucles 2020permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/42/m/j/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s20_qp_43.pdf": {
            "1": "*6591584314* chemistry  0620/43 paper 4 theory (extended) may/june 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 06_0620_43/5rp \u00a9 ucles 2020 [turn overthis document has 16 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/43/m/j/20 \u00a9 ucles 2020 1 (a)\t\tthe\tstructures\tof\tfive\torganic\tcompounds,\t a,\tb,\tc,\td\tand\te,\tare\tshown. \t\tanswer\tthe\tquestions\tthat\tfollow. \t\teach\tletter\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. hch hca h hcco oh hc ccc hhh h hh hch hcb h hchh h h hch hcco oh hhch hcde h hcoh hh h  (i)\t\tgive\tthe\tletter\tof\tthe\tcompound\tthat\tis\tpropan-1-ol.  \t ... \t\t[1]  (ii)\t\tgive\tthe\tletter\tof\tthe\tcompound\tthat\thas\tthe\tempirical\tformula\tch2.  \t ... \t\t[1]  (iii)\t\tgive\tthe\tletter\tof\tone\tcompound\tthat\treacts\twith\tbromine\tin\tan\taddition\treaction.  \t ... \t\t[1]  (iv)\t\tgive\tthe\tletter\tof\tone\tcompound\tthat\treacts\twith\tchlorine\tto\tform\tthe\tcompound\tshown. hch hccl hchh h  \t ... \t\t[1]  (v)\t\tgive\tthe\tletters\tof\ttwo\tcompounds\tthat\tcan\treact\twith\teach\tother\tto\tform\tan \tester. \t ... \t\tand\t\t\t.. \t\t[1]  (vi)\t\tgive\tthe\tletter\tof\tthe\tcompound\tthat\tis\tin\tthe\tsame\thomologous\tseries\tas\thex-1-ene.  \t ... \t\t[1]  (vii)\t\tgive\tthe\tletter\tof\tone\tcompound\tthat\tis\tan\tacid.  \t ... \t\t[1]",
            "3": "3 0620/43/m/j/20 \u00a9 ucles 2020 [turn over  (viii)\t\tdraw\ta\tstructural\tisomer\tof\tcompound\t d. \t \tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds. \t [1]  (b)\t\tsome\tacids\tare\tdescribed\tas\tweak\tacids. \t\tstate\tthe\tmeaning\tof\tthe\tterm\tweak acid . \t weak\t\t .. \t acid\t\t  \t [2] \t [total:\t10]",
            "4": "4 0620/43/m/j/20 \u00a9 ucles 2020 2\t\tammonia\tis\tmanufactured\tby\tthe\thaber\tprocess.  (a)\t\tthe\tequation\tfor\tthe\treaction\tis\tshown. n2(g)\t\t+\t\t3h2(g)\t\t\t\t2nh3(g)  (i)\t\tstate\twhat\tis\tmeant\tby\tthe\tsymbol\t .  \t ... \t\t[1]  (ii)\t\tstate\tone\tsource\tof\thydrogen\tused\tin\tthe\tmanufacture\tof\tammonia.  \t ... \t\t[1]  (b)\t\tthe\ttable\tshows\tsome\tdata\tfor\tthe\tproduction\tof\tammonia. pressure /\tatmtemperature / \u00b0cpercentage\tyield of\tammonia 250 350 58 100 450 28 400 450 42 250 550 20 \t\tdeduce\tthe\teffect\ton\tthe\tpercentage\tyield\tof\tammonia\tof:  \u25cf\tincreasing\tthe\tpressure\tof\tthe\treaction  \t  \u25cf\tincreasing\tthe\ttemperature\tof\tthe\treaction.  \t \t [2]  (c)\t\texplain,\tin\tterms\tof\tparticles,\twhat\thappens\tto\tthe\trate\tof\tthis\treaction\twhen\tthe\ttemperature\t is\tincreased.  \t  \t  \t  \t  \t  \t.. \t\t[3]",
            "5": "5 0620/43/m/j/20 \u00a9 ucles 2020 [turn over  (d)\t\tammonia,\tnh3,\tis\tused\tto\tproduce\tnitric\tacid,\thno3.\tthis\thappens\tin\ta\tthree-stage\tprocess.   stage 1\tis\ta\tredox\treaction. 4nh3\t\t+\t\t5o2  \u2192\t\t4no\t\t+\t\t6h2o  (i)\t\tidentify\twhat\tis\toxidised\tin\t stage 1. \t \tgive\ta\treason\tfor\tyour\tanswer. \t \tsubstance\toxidised\t \t . \t \treason\t\t .  \t . \t [2]  (ii)\t\tin\tthis\treaction\tthe\tpredicted\tyield\tof\tno \tis\t512\tg.\tthe\tactual\tyield\tis\t384\t g. \t \tcalculate\tthe\tpercentage\tyield\tof\tno\tin\t this\treaction. \t percentage\tyield\tof\tno\t=\t..\t\t[1]  (iii)\t\tthe\tequation\tfor\tthe\treaction\tin\tstage 2\tis\tshown. 2no\t\t+\t\to2  \u2192\t\t2no2 \t \twhich\tmajor\tenvironmental\t problem\tdoes\tno2\tcause\tif\tit\tis\treleased\tinto\tthe\tatmosphere?  \t .  \t ... \t\t[1]",
            "6": "6 0620/43/m/j/20 \u00a9 ucles 2020  (iv)\t\tthe\tequation\tfor\tthe\treaction\tin\tstage 3\tis\tshown. 4no2\t\t+\t\t2h2o\t\t+\t\to2  \u2192\t\t4hno3 \t \tcalculate\t the\tvolume\tof\to2\tgas,\tat\troom\ttemperature\t and\tpressure\t(r.t.p.),\tneeded\tto\t produce\t1260\t g\tof\thno3. \t \tuse\tthe\tfollowing\tsteps.  \u25cf\tcalculate\tthe\tnumber\tof\tmoles\tof\thno3. \t moles\tof\thno3\t=\t..  \u25cf\tdeduce\tthe\tnumber\tof\tmoles\tof\to2\tthat\treacted. \t moles\tof\to2\t=\t..  \u25cf\tcalculate\tthe\tvolume\tof\to2\tgas\tthat\treacts\tat\troom\ttemperature\tand\tpressure\t(r.t.p.). \t volume\tof\to2\tgas\t=\t..\t\tdm3  \t [4]  (e)\t\tthe\treaction\tin\t stage 3\tis\texothermic. 4no2\t\t+\t\t2h2o\t\t+\t\to2  \u2192\t\t4hno3 \t\tcomplete\t the\tenergy\tlevel\tdiagram\tfor\tthis\treaction.\tinclude\tan\tarrow\tthat\tclearly\tshows\tthe\t energy\tchange\tduring\tthe\treaction. energy progress of reaction4no2 + 2h2o + o2 \t [3] \t [total:\t18]",
            "7": "7 0620/43/m/j/20 \u00a9 ucles 2020 [turn over 3\t\tchlorine\tis\tin\tgroup\tvii\tof\tthe\tperiodic\t table.  (a)\t\ttwo\tisotopes\tof\tchlorine\tare\tchlorine-35\tand\tchlorine-37.  (i)\t\tstate\twhy\tthese\ttwo\tisotopes\tof\tchlorine \thave\tthe\tsame\tchemical\tproperties.  \t .  \t .  \t ... \t\t[2]  (ii)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\teach\tatom\t and\tion. number\tof electronsnumber\tof neutronsnumber\tof protons 35cl17 37cl \u2013 17 \t [3]  (b) (i)\t\tchlorine\treacts\twith\taqueous\tsodium\tbromide.\t \t \tthe\tequation\tfor\tthe\treaction\tis\tshown. cl 2\t\t+\t\t2nabr\t\t \u2192\t\t2nacl\t\t+\t\tbr2 \t \tstate\tthe\ttype\tof\treaction\tshown.  \t ... \t\t[1]  (ii)\t\twhy\tis\tthere\tno\treaction\tbetween\tiodine \tand\taqueous\tsodium\tbromide?  \t ... \t\t[1]  (c)\t\tmagnesium\treacts\twith\tchlorine\tto\tform\tmagnesium \tchloride. \t\tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t of\tthe\tions\tin\t magnesium\tchloride.\tgive\tthe\tcharges\ton\tthe\tions. \t\tthe\tinner\tshells\thave\tbeen\tcompleted. cl. . mg \t [3]",
            "8": "8 0620/43/m/j/20 \u00a9 ucles 2020  (d)\t\thydrogen\tand\tchlorine\treact\tto\tform\thydrogen\tchloride\tgas,\tas\tshown\tin\tthe\tequation. \th2\t +\t cl 2 \u2192\t 2hcl \t\tthis\tequation\tcan\tbe\trepresented\tas\tshown. h\u2013h\t\t+\t\tcl\t\u2013c l  \u2192\t\t2h\u2013cl \t\tsome\tbond\tenergies\tare\tshown\tin\tthe\ttable. bondbond\tenergy in\tkj\t/\tmol h\u2013h 436 cl\t\u2013c l243 h\u2013cl 432 \t\tcalculate\t the\tenergy\tchange\tfor\tthe\treaction\tbetween\thydrogen\t and\tchlorine,\tusing\tthe\t following\tsteps.  \u25cf\tcalculate\tthe\tenergy\tneeded\tto\tbreak\tthe\tbonds. \t ..\t\tkj  \u25cf\tcalculate\tthe\tenergy\treleased\twhen\tbonds\tare\tformed. \t ..\t\tkj  \u25cf\tcalculate\tthe\tenergy\tchange\tfor\tthe\treaction. \t ..\tkj\t /\tmol \t [3] \t [total:\t13]",
            "9": "9 0620/43/m/j/20 \u00a9 ucles 2020 [turn over 4 (a)\t\tfiltration\tand\tchlorination\tare\ttwo\tstages\tin\twater\ttreatment. \t\tstate\tthe\tpurpose\tof\teach\tstage. \t filtration\t\t ..  \t \t chlorination\t \t  \t \t [2]  (b)\t\ta\tstudent\tuses\tanhydrous\tcopper( ii)\tsulfate\tto\ttest\tfor\tthe\tpresence\tof\twater.  (i)\t\twhat\tcolour\tchange\tis\tseen\tif\twater\tis\tpresent? \t from\t\t\tto\t\t \t... \t\t[2]  (ii)\t\tthe\tpurity\tof\ta\tsample\tof\twater\tcan\tbe\tassessed\tby\tmeasuring\tits\tboiling\tpoint. \t \thow\tis\tthe\tboiling\tpoint\tof\twater\taffected\tby\timpurities?  \t ... \t\t[1]  (c)\t chromatography\tcan\tbe\tused\tto\ttest\tthe\tpurity\tof\tsubstances. \t\tthe\tdiagram\tshows\tthe\tchromatogram\tof\ta\tcoloured\tsubstance. xsolvent front start line  (i)\t\thow\tdoes\tthis\tchromatogram\tshow\tthat \tthis\tsubstance\tis\tnot\tpure?  \t ... \t\t[1]  (ii)\t\tdraw\ta\tcircle\tround\tthe\tcorrect\trf\tvalue\tfor\tthe\tspot\tlabelled\t x. \t 0.2\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t0.4\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t0.8\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t1.2\t [1]  (iii)  state\thow\ta\tcolourless\tsubstance\tcan\tbe\tmade\tvisible\ton\ta\tchromatogram.  \t ... \t\t[1] \t [total:\t8]",
            "10": "10 0620/43/m/j/20 \u00a9 ucles 2020 5 (a)\t\tcomplete\tthe\ttable\tabout\tsolids,\tliquids\tand\tgases. particle separationparticle arrangementtype\tof motion solid regular vibrate\tonly liquid touching random gas apart random \t [3]  (b)\t\tthe\tgraph\tshows\tthe\tchange\tin\ttemperature\tas\ta\tsample\tof\ta\tgas\tis\tcooled. temperature timeab \t\tname\tthe\tchange\tof\tstate\ttaking\tplace\tbetween\t a\tand\tb.  \t.. \t\t[1]  (c)\t\ta\tbottle\tof\tliquid\tperfume\tis\tleft\topen\tat\tthe\tfront\tof\ta\troom. \t\tafter\tsome\ttime,\tthe\tperfume\tis\tsmelt\tat\tthe\tback\tof\tthe\troom. \t\tname\tthe\ttwo\tphysical\tprocesses\ttaking\tplace. \t 1\t\t .  2 \t. \t [2] \t [total:\t6]",
            "11": "11 0620/43/m/j/20 \u00a9 ucles 2020 [turn over 6 (a)\t\tan\tendothermic\treaction\toccurs\twhen\tcalcium\tnitrate\tis\theated.  (i)\t\tbalance\tthe \tequation\tfor\tthis\treaction. \t .ca(no3)2  \u2192\t\t.cao\t\t+\t\t.no2\t\t+\t\t.o2\t [1]  (ii)\t\tstate\tthe\ttype\tof\treaction\tshown\tby\tthe\t equation.  \t ... \t\t[1]  (b)\t describe\tthe\ttest\tfor\ta\tnitrate\tion.  test \t.  \t \t result\t\t ..  \t \t [3] \t [total:\t5]",
            "12": "12 0620/43/m/j/20 \u00a9 ucles 2020 7\t\taluminium\tis\textracted\tby\telectrolysis.\tiron\tis\textracted\tfrom\tits\tore\tby\treduction\twith\tcarbon.  (a)\t\twhat\tis\tmeant\tby\tthe\tterm\telectrolysis ?  \t  \t.. \t\t[2]  (b)\t\tname\tthe\tmain\tore\tof\taluminium.  \t.. \t\t[1]  (c) (i)\t\texplain\twhy\taluminium\t cannot\tbe\textracted\tby\treduction\twith\tcarbon.  \t ... \t\t[1]  (ii)\t\tdescribe\tthe\trole\tof\tcryolite\tin\tthe\textraction\tof\taluminium\tby\telectrolysis.  \t ... \t\t[1]  (iii)\t\tname\tthe\tproduct\tformed\tat\tthe\tpositive \telectrode.  \t ... \t\t[1]  (iv)\t\twrite\tthe\tionic\thalf-equation\tfor\tthe\treaction\tat\tthe\tnegative\telectrode.  \t ... \t\t[2]  (d)\t\taluminium\tis\tused\tin\toverhead\telectricity\tcables. \t\tgive\ttwo\tproperties\tof\taluminium\tthat\tmake\tit\tsuitable\tfor\tuse\tin\toverhead\telectricity\tcables. \t 1\t\t .  2 \t. \t [2]",
            "13": "13 0620/43/m/j/20 \u00a9 ucles 2020 [turn over  (e)\t\tiron\tis\ta\ttransition\telement.  (i)\t\tiron\tforms\thydrated\tiron( iii)\toxide\twhen \tit\trusts. \t \twrite\ta\tword\tequation\tto\trepresent\tthe\tformation\tof\trust.  \t ... \t\t[2]  (ii)\t\tgive\t two\tways\tin\twhich\tthe\tproperties\t of\ttransition\telements\tdiffer\tfrom\tthe\tproperties\t of\t group\ti\tmetals. \t 1\t\t ..  2 \t .. \t [2] \t [total:\t14]",
            "14": "14 0620/43/m/j/20 \u00a9 ucles 2020 8 (a)\t\tpart\tof\tthe\tsynthetic\tpolymer,\tnylon,\tis\tshown\tin\tthe \tdiagram. co co c co o n hn hn hn hco  (i)\t\tcircle\tone\tamide\tlinkage\t on the diagram.\t [1]  (ii)\t\tcomplete\tthe\tstructures\tof\tthe\ttwo\tmonomers\tthat\treact\tto\tform\tnylon. \t [2]  (iii)\t\tname\tthe\tother\tproduct\tformed\twhen\tnylon\tis\tproduced.  \t ... \t\t[1]  (b)\t\titems\tmade\tfrom\tnylon\tare\toften\tdisposed\t of\tby\tburying\tthem\tin\tthe\tground.\tthis\tis\tcalled\t landfill. \t\twhy\tis\tthe\tdisposal\tof\tnylon\tusing\tlandfill\ta\tproblem?  \t  \t.. \t\t[1]  (c)\t\tgive\tthe\tname\tof\ta\tnatural\tpolymer.  \t.. \t\t[1] \t [total:\t6]",
            "15": "15 0620/43/m/j/20 \u00a9 ucles 2020permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/43/m/j/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s20_qp_51.pdf": {
            "1": "*8002682082* chemistry  0620/51 paper 5 practical test may/june 2020  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib20 06_0620_51/2rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/51/m/j/20 \u00a9 ucles 2020 1  you are going to investigate the reaction between dilute hydrochloric acid and two different aqueous  solutions of sodium carbonate labelled solution e and solution f.   read all of the instructions carefully before starting the experiments.   instructions   you are going to do three experiments.  (a) experiment 1  \u25cf fill the burette up to the 0.0 cm3 mark with dilute hydrochloric acid.  \u25cf use the measuring cylinder to pour 25 cm3 of solution e into the conical flask.  \u25cf add five drops of thymolphthalein indicator to the conical flask.  \u25cf slowly add dilute hydrochloric acid from the burette to the conical flask, while swirling the  flask, until the solution just changes colour.  \u25cf record the burette readings in the table and complete the table. experiment 1 final burette reading / cm3 initial burette reading / cm3 volume of dilute hydrochloric acid added / cm3   experiment 2  \u25cf empty the conical flask and rinse it with distilled water.  \u25cf refill the burette with dilute hydrochloric acid.  \u25cf repeat experiment 1 using five drops of methyl orange indicator instead of  thymolphthalein indicator.  \u25cf record the burette readings in the table and complete the table. experiment 2 final burette reading / cm3 initial burette reading / cm3 volume of dilute hydrochloric acid added / cm3",
            "3": "3 0620/51/m/j/20 \u00a9 ucles 2020 [turn over  experiment 3  \u25cf empty the conical flask and rinse it with distilled water.  \u25cf refill the burette with dilute hydrochloric acid.  \u25cf use the measuring cylinder to pour 25 cm3 of solution f into the conical flask.  \u25cf add five drops of methyl orange indicator to the conical flask.  \u25cf slowly add dilute hydrochloric acid from the burette to the conical flask, while swirling the  flask, until the solution just changes colour.  \u25cf record the burette readings in the table and complete the table. experiment 3 final burette reading / cm3 initial burette reading / cm3 volume of dilute hydrochloric acid added / cm3  [5]  (b) (i)  what colour change was observed in the conical flask in experiment 1?  from  to  ...  [1]  (ii)  what colour change was observed in the conical flask in experiment 2?  from  to  ...  [1]  (c)  compare the volumes of dilute hydrochloric acid added in experiment 2 and experiment 3.   explain any difference.      ..   [2]  (d)  determine the simplest whole number ratio of volumes of dilute hydrochloric acid used in  experiments 1 and 2.  ratio experiment 1 : experiment 2 = ..  [1]  (e)  what volume of dilute hydrochloric acid would be required if experiment 3 was repeated using  thymolphthalein indicator instead of methyl orange indicator?  volume = ..  [2]",
            "4": "4 0620/51/m/j/20 \u00a9 ucles 2020  (f)  the conical flask was rinsed with distilled water between each experiment.  (i)  why was the conical flask rinsed?   .   ...   [1]  (ii)  why does it not matter if a little distilled water is left in the flask after it has been rinsed?   .   ...   [1]  (g)  state two sources of error in the experiments. for each error suggest an improvement that  would reduce the error.  source of error 1    improvement 1  ...     source of error 2    improvement 2  ...     [4]  [total: 18]",
            "5": "5 0620/51/m/j/20 \u00a9 ucles 2020 [turn over 2  you are pro vided with two solids, solid g and solid h.   do the following tests on solid g and solid h, recording all of your observations at each stage.   tests on solid g  (a)  place about half of solid g in a hard\u2011glass test\u2011tube. heat the solid gently and then strongly.   record your observations.            ..   [2]  (b) (i)  place the remaining half of solid g in a boiling tube.   add about 10 cm3 of dilute sulfuric acid to the boiling tube. test any gas produced.   keep the solution formed for use in (c).   record your observations.   .   .   .   ...   [4]  (ii)  identify the gas produced in (b)(i).   ...   [1]  (c)  leave the solution from (b) to settle for three minutes. carefully pour about half of the solution  into another boiling tube.   to this portion add aqueous ammonia slowly until in excess.   record your observations.            ..   [3]  (d)  what conclusions can you make about solid g?      ..   [2]",
            "6": "6 0620/51/m/j/20 \u00a9 ucles 2020  tests on solid h  (e)  carry out a flame test on solid h.   record your observations.   ..   [1]   add solid  h to about 10 cm3 of distilled water in a boiling tube. stopper the boiling tube and shake  it to dissolve solid h and form solution h.  (f)  add about 1 cm depth of dilute nitric acid and a few drops of aqueous barium nitrate to  solution h.   record your observations.   ..   [1]  (g)  identify solid h.   ..   [2]  [total: 16]",
            "7": "7 0620/51/m/j/20 \u00a9 ucles 2020 [turn over 3  cobalt, manganese and nickel are metals. they react with dilute hydrochloric acid to form hydrogen  gas.   plan an investigation to find the order of reactivity of these three metals.   you are provided with:  \u25cf samples of each metal  \u25cf dilute hydrochloric acid  \u25cf common laboratory apparatus.   your plan must make it clear how your investigation will be a fair test and how you will use your  results to place these metals in order of reactivity.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/51/m/j/20 \u00a9 ucles 2020blank page",
            "9": "9 0620/51/m/j/20 \u00a9 ucles 2020blank page",
            "10": "10 0620/51/m/j/20 \u00a9 ucles 2020blank page",
            "11": "11 0620/51/m/j/20 \u00a9 ucles 2020notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/51/m/j/20 \u00a9 ucles 2020tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s20_qp_52.pdf": {
            "1": "*3649515752* chemistry  0620/52 paper 5 practical test may/june 2020  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib20 06_0620_52/3rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/52/m/j/20 \u00a9 ucles 2020 1  you are going to investigate the temperature change when magnesium ribbon reacts with  dilute sulfuric acid.   read all of the instructions carefully before starting the experiments.   instructions \t\tyou\tare\tgoing\tto\tdo\tfive\texperiments.  experiment 1  \u25cf use a measuring cylinder to pour 20 cm3 of dilute sulfuric acid into a boiling tube.  \u25cf use a thermometer to measure the initial temperature of the acid. record the initial temperature  in the table in (a).  \u25cf place a 1 cm length of magnesium ribbon into the boiling tube.  \u25cf continually stir the acid and magnesium ribbon in the boiling tube using a thermometer. make  sure the magnesium ribbon remains in the acid.  \u25cf measure the highest\t temperature\t reached\tby\t the\tmixture.\t record\tthe\t highest\ttemperature\t of\t the\tmixture\tin\tthe\ttable\tin\t (a).  \u25cf rinse out the boiling tube with distilled water.  experiment 2  \u25cf\trepeat\texperiment\t1\tusing\ta\t2\t cm\tlength\tof\tmagnesium\tribbon\tinstead\tof\tthe\t1\t cm\tlength.  experiment 3  \u25cf\trepeat\texperiment\t1\tusing\ta\t3\t cm\tlength\tof\tmagnesium\tribbon\tinstead\tof\tthe\t1\t cm\tlength.  experiment 4  \u25cf\trepeat\texperiment\t1\tusing\ta\t5\t cm\tlength\tof\tmagnesium\tribbon\tinstead\tof\tthe\t1\t cm\tlength.  experiment 5  \u25cf\trepeat\texperiment\t1\tusing\ta\t6\t cm\tlength\tof\tmagnesium\tribbon\tinstead\tof\tthe\t1\t cm\tlength.  (a)  complete the table. experimentlength of magnesium ribbon / cminitial temperature / \u00b0chighest temperature / \u00b0ctemperature increase / \u00b0c 1 2 3 4 5  [4]  (b)\t\tin\twhich\texperiment,\t1,\t2,\t3,\t4\tor\t5,\twas\tthe\ttemperature\tincrease\tthe\tlargest?   ..   [1]",
            "3": "3 0620/52/m/j/20 \u00a9 ucles 2020 [turn over  (c)  add a suitable scale to the y-axis\t and\tplot\tyour\tresults\tfrom\texperiments\t 1\tto\t5\ton\tthe\tgrid.\t draw\ta\tline\tof\tbest\tfit,\tmaking\tsure\tthat\tyour\tline\tpasses\tthrough\t(0,0). 00 1234 length of magnesium ribbon  / cmtemperature increase  / \u00b0c 56 \t [5]  (d)\t\texplain\twhy\tthe\tgraph\tline\tmust\tpass\tthrough\t(0,0).      ..   [1]  (e)  from your graph,\t deduce\tthe\ttemperature\t increase\t if\texperiment\t 1\tis\trepeated\t using\ta\t4\tcm\t length of magnesium ribbon.   show clearly on the grid  how you worked out your answer.  .. \u00b0c  [2]",
            "4": "4 0620/52/m/j/20 \u00a9 ucles 2020  (f) (i)\t \twhy\twould\tcarrying\t out\tthe\texperiment\t in\ta\tpolystyrene\t cup\trather\tthan\ta\tboiling\ttube\t improve\tthe\taccuracy\tof\tthe\tresults?   .   ...   [1]  (ii)  sketch on the grid\t the\tgraph\tyou\twould\texpect\tif\tthe\texperiment\t was\trepeated\t using\ta\t polystyrene cup instead of a boiling tube. [1]  (g)  the volume of dilute sulfuric acid could be measured with a 20 cm3 pipette.  (i)  state one advantage of using a pipette rather than a measuring cylinder.   .   ...   [1]  (ii)  state one disadvantage of using a pipette rather than a measuring cylinder.   .   ...   [1]  [total: 17]",
            "5": "5 0620/52/m/j/20 \u00a9 ucles 2020 [turn over 2\t\tyou\tare\tprovided\twith\ttwo\tsubstances,\tsolid\t l and solid m.   do the following tests on solid l and solid m,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.  tests on solid l  (a)  describe the appearance of solid l.   ..   [1]   place solid l in a boiling tube. add about 20 cm3 of distilled water to the boiling tube. place a  stopper in the boiling tube and shake the tube to dissolve solid l and form solution l.   divide solution l\tinto\tfive\tapproximately\tequal\tportions\tin\tfive\ttest-tubes.  (b)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tl.  ph = ..  [1]  (c)  to the second portion of solution l add about 1 cm depth of dilute nitric acid followed by about  1\tcm\tdepth\tof\taqueous\t silver\tnitrate.\tleave\tthe\ttest-tube\t to\tstand\tfor\tat\tleast\tfive\tminutes.\t continue\twith\tthe\trest\tof\tthe\texperiment\twhile\tthe\ttest-tube\tis\tleft\tto\tstand.   record your observations after the test-tube has been left to stand.      ..   [1]  (d)  to the third portion of solution l\tadd\tapproximately\t5\t cm3\tof\taqueous\tsodium\tcarbonate.   record your observations.         ..   [2]  (e)  to the fourth portion of solution l\tadd\taqueous\t sodium\thydroxide\t slowly\tuntil\tit\tis\tin\texcess\tand\t no further changes are seen.   record your observations.         ..   [2]",
            "6": "6 0620/52/m/j/20 \u00a9 ucles 2020  (f)\t\tto\tthe\tfifth\tportion\tof\tsolution\t l\tadd\taqueous \tammonia\t slowly\tuntil\tit\tis\tin\texcess\tand\tno\tfurther\t changes are seen.   record your observations.      ..   [2]  (g)  identify solid l.      ..   [2]   tests on solid m  (h)\t\tcarry\tout\ta\tflame\ttest\ton\tsolid\tm.   record your observations.   ..   [1]  (i)  place the remaining solid m into a boiling tube.   add about 10 cm3 of dilute nitric acid to solid m in the boiling tube.   test any gas produced.   record your observations.   keep the solution formed for (j).         ..   [2]  (j)  to the solution formed in (i)\tadd\tabout\t1\t cm\tdepth\tof\taqueous\tbarium\tnitrate.   record your observations.   ..   [1]  (k)  identify solid m.   ..   [2]  [total: 17]",
            "7": "7 0620/52/m/j/20 \u00a9 ucles 2020 [turn over 3\t\tmany\twindow-cleaning\t products\t contain\taqueous\t ammonia.\t aqueous\t ammonia\t is\tan\talkali\tthat\t reacts with dilute acids. \t\tplan\tan\tinvestigation\t to\tfind\twhich\tof\ttwo\twindow-cleaning\t products\t contains\t the\tmore\tconcentrated\t aqueous\tammonia.\tinclude\tin\tyour\tplan:  \u25cf the method you will use  \u25cf how your results will be used to determine which window-cleaning product contains the most  concentrated\taqueous\tammonia. \t\tyou\tare\tprovided\t with\tan\taqueous\t solution\t of\tthe\ttwo\twindow-cleaning\t products,\t   dilute hydrochloric acid of known concentration and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6]",
            "8": "8 0620/52/m/j/20 \u00a9 ucles 2020blank page",
            "9": "9 0620/52/m/j/20 \u00a9 ucles 2020blank page",
            "10": "10 0620/52/m/j/20 \u00a9 ucles 2020blank page",
            "11": "11 0620/52/m/j/20 \u00a9 ucles 2020notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/52/m/j/20 \u00a9 ucles 2020tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s20_qp_53.pdf": {
            "1": "*7162925480* chemistry  0620/53 paper 5 practical test may/june 2020  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib20 06_0620_53/2rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/53/m/j/20 \u00a9 ucles 2020 1  you are going to investigate the temperature change when aqueous sodium hydroxide neutralises  dilute hydrochloric acid. the equation for the reaction is shown. naoh  +  hcl  \u2192  nacl  +  h2o   read all of the instructions carefully before starting the experiments.   instructions   you are going to do eight experiments.   experiment 1  \u25cf place the polystyrene cup into the 250 cm3 beaker for support.  \u25cf use a measuring cylinder to pour 5 cm3 of aqueous sodium hydroxide into the polystyrene cup.  \u25cf use a measuring cylinder to pour 45 cm3 of dilute hydrochloric acid into the polystyrene cup.  \u25cf stir the mixture in the polystyrene cup with the thermometer. record the highest temperature  reached in the table in (a).  \u25cf rinse out the polystyrene cup with distilled water.   experiment 2  \u25cf repeat experiment 1 using 10 cm3 of aqueous sodium hydroxide and 40 cm3 of  dilute hydrochloric acid.  experiment 3  \u25cf repeat experiment 1 using 15 cm3 of aqueous sodium hydroxide and 35 cm3 of  dilute hydrochloric acid.  experiment 4  \u25cf repeat experiment 1 using 20 cm3 of aqueous sodium hydroxide and 30 cm3 of  dilute hydrochloric acid.  experiment 5  \u25cf repeat experiment 1 using 30 cm3 of aqueous sodium hydroxide and 20 cm3 of  dilute hydrochloric acid.  experiment 6  \u25cf repeat experiment 1 using 35 cm3 of aqueous sodium hydroxide and 15 cm3 of  dilute hydrochloric acid.  experiment 7  \u25cf repeat experiment 1 using 40 cm3 of aqueous sodium hydroxide and 10 cm3 of  dilute hydrochloric acid.  experiment 8  \u25cf repeat experiment 1 using 45 cm3 of aqueous sodium hydroxide and 5 cm3 of  dilute hydrochloric aci d.",
            "3": "3 0620/53/m/j/20 \u00a9 ucles 2020 [turn over  (a)  complete the table. experiment 1 2 3 4 5 6 7 8 volume of aqueous sodium hydroxide / cm3 5 10 15 20 30 35 40 45 volume of dilute hydrochloric acid / cm3 highest temperature reached / \u00b0c  [4]  (b)  add a suitable scale to the y-axis. your scale should extend by at least 2 \u00b0c above your highest  temperature. plot your results from experiments 1 to 8 on the grid. draw two straight lines  through your points. extend your straight lines so that they cross. 05 10 15 20 volume of aqueous sodium hydroxide  / cm3highest temperature reached  / \u00b0c 25 30 35 40 50 45  [5]",
            "4": "4 0620/53/m/j/20 \u00a9 ucles 2020  (c)  the point on the graph where the two straight lines cross is where all of the  aqueous sodium hydroxide reacts with all of the dilute hydrochloric acid to form a neutral  solution.  (i)  use your graph to deduce the volume of aqueous sodium hydroxide and the volume of  dilute hydrochloric acid that react together to produce a neutral solution.   show your working on the grid .  volume of aqueous sodium hydroxide = .. cm3  volume of dilute hydrochloric acid = .. cm3  [3]  (ii)  use your graph to determine the highest temperature reached if the volumes in (c)(i)  were mixed together.  highest temperature reached = .. \u00b0c  [1]  (iii)  which solution, aqueous sodium hydroxide or dilute hydrochloric acid, was the most  concentrated?   use your answer to (c)(i) to explain why.   most concentrated solution  .   explanation  .   .  [1]  (d)  on the graph, sketch the lines you would expect to obtain if a copper can was used instead of  a polystyrene cup. [2]  (e)  give one advantage and one disadvantage of using a burette, instead of a measuring cylinder,  to add the dilute hydrochloric acid directly into the polystyrene cup.  advantage  ..     disadvantage  .     [2]  (f)  how could the reliability of the results of this investigation be checked?      ..   [1]  [total: 19]",
            "5": "5 0620/53/m/j/20 \u00a9 ucles 2020 [turn over 2  you are provided with two solids, solid n and solid p.   do the following tests on solid n and solid p, recording all of your observations at each stage.  tests on solid n  (a)  describe the appearance of solid n.   ..   [1]  (b)  add about 10 cm3 of distilled water to the boiling tube containing solid n. place a stopper in the  boiling tube and shake the tube to dissolve solid n and form solution n.   divide solution n into two approximately equal portions in two boiling tubes.  (i)\t\tto\tthe\tfirst\tportion\tof\tsolution\t n add aqueous ammonia slowly until it is in excess and no  further changes are seen.   record your observations.   .   .   ...   [2]  (ii)  to the second portion of solution n add aqueous sodium hydroxide slowly until it is in  excess and no further changes are seen.   keep the product for (b)(iii).   record your observations.   .   .   ...   [2]  (iii)  pour about 3 cm depth of the product from (b)(ii)  into a boiling tube. add a piece of  aluminium foil and warm the mixture gently. test any gas produced.   record your observations.   .   .   ...   [2]  (c)  identify solid n.      ..   [2]",
            "6": "6 0620/53/m/j/20 \u00a9 ucles 2020  tests on solid p  (d)\t\tcarry\tout\ta\tflame\ttest\ton\tsolid\tp.   record your observations.   ..   [1]  (e)  place solid p in a boiling tube. add about 10 cm3 of distilled water to the boiling tube. place a  stopper in the boiling tube and shake the tube to dissolve solid p and form solution p.   divide solution p into three approximately equal portions in three test-tubes.  (i)\t\tto\tthe\tfirst\tportion\tof\tsolution\t p add about 1 cm depth of dilute nitric acid and a few drops  of aqueous silver nitrate.   record your observations.   ...   [1]  (ii)  to the second portion of solution p add about 1 cm depth of dilute nitric acid and a few  drops of aqueous barium nitrate.   record your observations.   .   ...   [1]  (iii)  add the third portion of solution p to the test-tube containing aqueous bromine.   record your observations.   .   ...   [1]  (f)  identify solid p.      ..   [2]  [total: 15]",
            "7": "7 0620/53/m/j/20 \u00a9 ucles 2020 [turn over 3  stayclean and brightwhite are two brands of washing powder. both contain sodium carbonate.   sodium carbonate is soluble in water and reacts with dilute sulfuric acid to produce carbon dioxide gas.   plan an investigation to determine which of the two washing powders, stayclean or brightwhite,    contains the greatest percentage of sodium carbonate.   you are provided with samples of the two washing powders and common laboratory apparatus and  chemicals.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/53/m/j/20 \u00a9 ucles 2020blank page",
            "9": "9 0620/53/m/j/20 \u00a9 ucles 2020blank page",
            "10": "10 0620/53/m/j/20 \u00a9 ucles 2020blank page",
            "11": "11 0620/53/m/j/20 \u00a9 ucles 2020notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/53/m/j/20 \u00a9 ucles 2020tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s20_qp_61.pdf": {
            "1": "*9101215028* chemistry  0620/61 paper 6 alternative to practical may/june 2020  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib20 06_0620_61/2rp \u00a9 ucles 2020 [turn overthis document has 8 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/61/m/j/20 \u00a9 ucles 2020 1  a student investigated the dyes contained in different coloured inks using chromatography. water  was the solvent. the diagram shows how the student set up the apparatus. chromatography pape r waterbaseline drawn in ink red orange yellow green blue purple black  (a)  identify two errors in the way the student set up the apparatus.  1  .  2  .  [2]  (b)  the student then carried out the chromatography correctly.   the diagram shows the results. red orange yellow green blue purple black  (i)  which ink contains the greatest number of soluble dyes?   ...   [1]  (ii)  which two inks are made of a single soluble dye?  ... and  ..  [1]  (iii)  from the chromatogram it is not possible to tell if the red ink contains different dyes. \t \tsuggest\t how\tthe\texperiment\t could\tbe\tchanged\t to\tfind\tout\tif\tthe\tred\tink\tcontains\t different\t dyes.   ...   [1]  [total: 5]",
            "3": "3 0620/61/m/j/20 \u00a9 ucles 2020 [turn over 2  a student investigated the reaction between dilute hydrochloric acid and two different aqueous  solutions of sodium carbonate, solution e and solution f.  three experiments were done.  (a) experiment 1  \u25cf a burette was filled up to the 0.0 cm3 mark with dilute hydrochloric acid.  \u25cf using a measuring cylinder, 25 cm3 of solution e was poured into a conical flask.  \u25cf five drops of thymolphthalein indicator were added to the conical flask.  \u25cf dilute hydrochloric acid was slowly added from the burette to the conical flask, while the  flask was swirled, until the solution just changed colour.   use the burette diagrams to complete the table for experiment 1. 0 1 2 initial reading9 10 11 final reading final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tdilute\thydrochloric\tacid\tadded\t /\tcm3   experiment 2  \u25cf the conical flask was emptied and rinsed with distilled water.  \u25cf the burette was refilled with dilute hydrochloric acid.  \u25cf experiment 1 was repeated using five drops of methyl orange indicator instead of  thymolphthalein indicator.   use the burette diagrams to complete the table for experiment 2. 5 6 7 initial reading24 25 26 final reading final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tdilute\thydrochloric\tacid\tadded\t /\tcm3",
            "4": "4 0620/61/m/j/20 \u00a9 ucles 2020   experiment 3  \u25cf the conical flask was emptied and rinsed with distilled water.  \u25cf the burette was refilled with dilute hydrochloric acid.  \u25cf using a measuring cylinder, 25 cm3 of solution f was poured into the conical flask.  \u25cf five drops of methyl orange indicator were added to the conical flask.  \u25cf dilute hydrochloric acid was slowly added from the burette to the conical flask, while the  flask was swirled, until the solution just changed colour.   use the burette diagrams to complete the table for experiment 3. 1 2 3 initial reading33 34 35 final reading final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tdilute\thydrochloric\tacid\tadded\t /\tcm3  [5]  (b)\t what\tcolour\tchange\twas\tobserved\tin\tthe\tconical\tflask\tin\texperiment\t2?  from  to  ..  [2]  (c)  compare the volumes of dilute hydrochloric acid added in experiment 2 and experiment 3.  explain any difference.      ..   [2]  (d)  determine the simplest whole number ratio of volumes of dilute hydrochloric acid used in  experiments 1 and 2.  ratio experiment 1 : experiment 2 = ..  [1]  (e)  what volume of dilute hydrochloric acid would be required if experiment 3 was repeated using  thymolphthalein indicator instead of methyl orange indicator?  volume = ..  [2]",
            "5": "5 0620/61/m/j/20 \u00a9 ucles 2020 [turn over  (f)\t the\tconical\tflask\twas\trinsed\twith\tdistilled\twater\tbetween\teach\texperiment.  (i)\t\twhy\twas\tthe\tconical\tflask\trinsed?   .   ...   [1]  (ii)  why does it not\tmatter\tif\ta\tlittle\tdistilled\twater\tis\tleft\tin\tthe\tflask\tafter\tit\thas\tbeen\trinsed?   .   ...   [1]  (g)  state two sources of error in the experiments. for each error suggest an improvement that  would reduce the error.   source of error 1     improvement 1  ...      source of error 2     improvement 2  ...     [4]  [total: 18]",
            "6": "6 0620/61/m/j/20 \u00a9 ucles 2020 3  two solids, solid g and solid h, were analysed. solid g was copper( ii) carbonate.   tests were done on each solid.   tests on solid g   complete the expected observations.  (a)  solid g was placed in a boiling tube. an excess of dilute sulfuric acid was added to the  boiling tube. any gas produced was tested.   observations  ..      ..   [3]  (b)  identify the gas produced in (a).   ..   [1]  (c)  aqueous ammonia was added slowly until in excess to the solution produced in (a).   observations  ..         ..   [3]",
            "7": "7 0620/61/m/j/20 \u00a9 ucles 2020 [turn over  tests on solid h   tests were done and the following observations were made. tests on solid h observations test 1 flame test yellow\tflame test 2 some of solid h was placed in a boiling tube.  the boiling tube was heated strongly.condensation appeared near the mouth of the boiling tube solid h was dissolved in distilled water. the  solution was divided into two equal portions. test 3 about 1 cm3 of dilute nitric acid followed by a  few drops of aqueous silver nitrate were added  to\tthe\tfirst\tportion\tof\tthe\tsolution.the solution remained colourless test 4 about 1 cm3 of dilute nitric acid followed by  a few drops of aqueous barium nitrate were  added to the second portion of the solution.white precipitate  (d)  what conclusion can be made from the result of test 3?      ..   [1]  (e)  what conclusions can be made about solid h from the results of test 1, test 2 and test 4?         ..   [3]  [total: 11]",
            "8": "8 0620/61/m/j/20 \u00a9 ucles 2020permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. 4  cobalt, manganese and nickel are metals. they react with dilute hydrochloric acid to form  hydrogen gas. \t\tplan\tan\tinvestigation\tto\tfind\tthe\torder\tof\treactivity\tof\tthese\tthree\tmetals.   you are provided with:  \u25cf samples of each metal  \u25cf dilute hydrochloric acid  \u25cf common laboratory apparatus.   your plan must make it clear how your investigation will be a fair test and how you will use your  results to place the metals in order of reactivity.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]"
        },
        "0620_s20_qp_62.pdf": {
            "1": "*7932494915* chemistry  0620/62 paper 6 alternative to practical may/june 2020  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib20 06_0620_62/3rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/62/m/j/20 \u00a9 ucles 2020blank page",
            "3": "3 0620/62/m/j/20 \u00a9 ucles 2020 [turn over 1  hot copper( ii) oxide reacts with hydrogen. the products are copper and steam.   the apparatus used to react copper( ii) oxide with hydrogen is shown. hydrogenunreacted hydrogen colourless liquid collected iceu-tubecopper( ii) oxide  (a)  draw an arrow on the diagram  to show where the apparatus should be heated. [1]  (b)  during the reaction the colour of the copper( ii) oxide changes.   state the colour change.  from ... to  ...  [1]  (c)  identify the colourless liquid collected.   ..   [1]  (d)  explain why the u-tube is in ice.      ..   [2]",
            "4": "4 0620/62/m/j/20 \u00a9 ucles 2020  (e) (i)  large amounts of unreacted hydrogen should not be allowed to escape into the laboratory.   state why.   ...   [1]  (ii)  complete the diagram to show how the unreacted hydrogen could be collected and its  volume measured.   label any apparatus that you draw. unreacted hydrogen colourless liquid collectediceu-tube  [2]  [total: 8]",
            "5": "5 0620/62/m/j/20 \u00a9 ucles 2020 [turn over 2  a student investigated the temperature change when magnesium ribbon reacts with  dilute sulfuric acid.   five experiments were done.   experiment 1  \u25cf using a measuring cylinder, 20 cm3 of dilute sulfuric acid were poured into a boiling tube.  \u25cf a thermometer was used to measure the initial temperature of the acid.  \u25cf a 1 cm length of magnesium ribbon was added to the acid in the boiling tube.  \u25cf the acid and magnesium ribbon in the boiling tube were stirred continuously using a  thermometer.   \u25cf the highest temperature reached by the mixture was measured.  \u25cf the boiling tube was rinsed out with distilled water.  experiment 2  \u25cf experiment 1 was repeated using a 2 cm length of magnesium ribbon instead of the 1 cm length.  experiment 3  \u25cf experiment 1 was repeated using a 3 cm length of magnesium ribbon instead of the 1 cm length.  experiment 4  \u25cf experiment 1 was repeated using a 5 cm length of magnesium ribbon instead of the 1 cm length.  experiment 5  \u25cf experiment 1 was repeated using a 6 cm length of magnesium ribbon instead of the 1 cm length.",
            "6": "6 0620/62/m/j/20 \u00a9 ucles 2020  (a)  use the information in the description of the experiments and the thermometer diagrams to  complete the table. experimentlength of magnesium ribbon / cminitial temperature highest temperature temperature increase / \u00b0cthermometer diagraminitial temperature of acid / \u00b0cthermometer diagramhighest temperature of acid / \u00b0c 130 25 2030 25 20 230 25 2030 25 20 330 25 2030 25 20 430 25 2040 35 30 530 25 2040 35 30  [4]  (b)  in which experiment, 1, 2, 3, 4 or 5, was the temperature increase the largest?   ..   [1]",
            "7": "7 0620/62/m/j/20 \u00a9 ucles 2020 [turn over  (c)  add a suitable scale to the y-axis and plot the results from experiments 1 to 5 on the grid.   draw a smooth line graph, making sure that your line passes through (0,0). 00 1 2 3 length of magnesium ribbon  / cmtemperature increase  / \u00b0c 4 5 6  [5]  (d)  explain why the graph line must pass through (0,0).      ..   [1]  (e)  from your graph, deduce the temperature increase if experiment 1 is repeated using a 4 cm  length of magnesium ribbon.   show clearly on the grid  how you worked out your answer.  ..  [3]  (f) (i)  why would carrying out the experiment in a polystyrene cup rather than a boiling tube  improve the accuracy of the results?   .   ...   [1]  (ii)  sketch on the grid the graph you would expect if the experiment was repeated using a  polystyrene cup instead of a boiling tube. [1]",
            "8": "8 0620/62/m/j/20 \u00a9 ucles 2020  (g)  the volume of dilute sulfuric acid could be measured with a 20 cm3 pipette.  (i)  state one advantage of using a pipette rather than a measuring cylinder.   .   ...   [1]  (ii)  state one disadvantage of using a pipette rather than a measuring cylinder.   .   ...   [1]  [total: 18]",
            "9": "9 0620/62/m/j/20 \u00a9 ucles 2020 [turn over 3  two solids, solid l and solid m, were analysed. solid l was chromium( iii) chloride.   tests were done on each solid.   tests on solid l   complete the expected observations.   solid l was dissolved in distilled water to produce solution  l. solution l was divided into four  portions in three test-tubes and a boiling tube.  (a)\t\tto\tthe\tfirst\tportion\tof\tsolution\t l in the boiling tube, about 1 cm depth of dilute hydrochloric acid  was added. the boiling tube was warmed gently. \t \ta\tstrip\tof\tfilter\tpaper\twas\tdipped\tin\tacidified\tpotassium\t manganate( vii) solution and held at  the mouth of the boiling tube.   observations     [1]  (b)  to the second portion of solution l aqueous sodium hydroxide was added slowly until it was in  excess and no further changes were seen.   observations  ..      ..   [2]  (c)  to the third portion of solution l aqueous ammonia was added slowly until it was in excess and  no further changes were seen.   observations  ..      ..   [2]  (d)  to the fourth portion of solution l about 1 cm depth of dilute nitric acid was added followed by  about 1 cm depth of aqueous silver nitrate.   observations  ..   ..   [1]",
            "10": "10 0620/62/m/j/20 \u00a9 ucles 2020  tests on solid m   tests were done and the following observations made. tests on solid m observations test 1 flame test yellow\tflame\tseen test 2 about 10 cm3 of dilute nitric acid was added to  solid m. any gas produced was tested.effervescence limewater turned milky test 3 about 1 cm depth of aqueous barium nitrate  was added to the solution formed by adding  dilute nitric acid to solid m in test 2.no change  (e)  identify solid m.   ..   [2]  [total: 8]",
            "11": "11 0620/62/m/j/20 \u00a9 ucles 2020 [turn over 4  many window-cleaning products contain aqueous ammonia. aqueous ammonia is an alkali that  reacts with dilute acids. \t\tplan\tan\tinvestigation\t to\tfind\twhich\tof\ttwo\twindow-cleaning\t products\t contains\t the\tmost\tconcentrated\t aqueous ammonia. include in your plan:  \u25cf the method you will use  \u25cf how your results will be used to determine which window-cleaning product contains the most  concentrated aqueous ammonia.   you are provided with an aqueous solution of the two window-cleaning products,   dilute hydrochloric acid of known concentration and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "12": "12 0620/62/m/j/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s20_qp_63.pdf": {
            "1": "*8571205354* chemistry  0620/63 paper 6 alternative to practical may/june 2020  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib20 06_0620_63/3rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/63/m/j/20 \u00a9 ucles 2020 1  a sample of rock salt contains sodium chloride and sand.   sodium chloride is soluble in water. sand is insoluble in water.   a student obtained dry crystals of pure sodium chloride from a lump of rock salt.   these are some of the steps the student used. step 1 step 2 step 3 grind the rock salt into smaller piecesadd the rock salt to water and heat while stirring with a glass rodfilter the mixturerock salt a bsand  (a)  name the apparatus labelled a in step 1.   ..   [1]  (b)  explain why the mixture is heated and stirred in step 2.   ..   [1]  (c) (i)  name the apparatus labelled b in step 3.   ...   [1]  (ii)\t\tstate\tthe\tscientific\tterm\tfor\tthe\tsand\tleft\ton\tthe\tfilter\tpaper\tin\tstep 3.   ...   [1]  (d)  describe what the student must do after step 3 to obtain dry crystals of pure sodium chloride.            ..   [3]  [total: 7]",
            "3": "3 0620/63/m/j/20 \u00a9 ucles 2020 [turn over 2  a student investigated the temperature change when aqueous sodium hydroxide neutralises dilute  hydrochloric acid. the equation for the reaction is shown. naoh  +  hcl  \u2192  nacl  +  h2o   eight experiments were done.   experiment 1  \u25cf a polystyrene cup was placed into a 250 cm3 beaker for support.  \u25cf using a measuring cylinder, 5 cm3 of aqueous sodium hydroxide was poured into the polystyrene  cup.  \u25cf using a measuring cylinder, 45 cm3 of dilute hydrochloric acid was poured into the polystyrene  cup.  \u25cf the mixture was stirred and the maximum temperature reached was measured using a  thermometer.  \u25cf the polystyrene cup was rinsed with distilled water.  experiment 2  \u25cf experiment 1 was repeated using 10 cm3 of aqueous sodium hydroxide and 40 cm3 of  dilute hydrochloric acid.   experiment 3  \u25cf experiment 1 was repeated using 15 cm3 of aqueous sodium hydroxide and 35 cm3 of  dilute hydrochloric acid.   experiment 4  \u25cf experiment 1 was repeated using 20 cm3 of aqueous sodium hydroxide and 30 cm3 of  dilute hydrochloric acid.   experiment 5  \u25cf experiment 1 was repeated using 30 cm3 of aqueous sodium hydroxide and 20 cm3 of  dilute hydrochloric acid.   experiment 6  \u25cf experiment 1 was repeated using 35 cm3 of aqueous sodium hydroxide and 15 cm3 of  dilute hydrochloric acid.   experiment 7  \u25cf experiment 1 was repeated using 40 cm3 of aqueous sodium hydroxide and 10 cm3 of  dilute hydrochloric acid.   experiment 8  \u25cf experiment 1 was repeated using 45 cm3 of aqueous sodium hydroxide and 5 cm3 of  dilute hydrochloric acid.",
            "4": "4 0620/63/m/j/20 \u00a9 ucles 2020  (a)  use the information in the description of the experiments and the thermometer diagrams to  complete the table. experimentvolume of aqueous sodium hydroxide / cm3volume of dilute hydrochloric acid / cm3thermometer diagramhighest temperature reached / \u00b0c 1 530 25 20 2 1030 25 20 3 1530 25 20 4 2030 25 20 5 3030 25 20 6 3530 25 20 7 4030 25 20 8 4530 25 20  [4]",
            "5": "5 0620/63/m/j/20 \u00a9 ucles 2020 [turn over  (b)  plot the results from experiments 1 to 8 on the grid. draw two straight lines through the points.  extend your straight lines so that they cross. 034 32 30 28 26 24 22 5 10 15 volume of aqueous sodium hydroxide  / cm3highest temperature reached  / \u00b0c 20 25 30 35 40 45 50  [4]  (c)  the point on the graph where the two straight lines cross is where all of the  aqueous sodium hydroxide reacts with all of the dilute hydrochloric acid to form a neutral  solution.  (i)  use your graph to deduce the volume of aqueous sodium hydroxide and the volume of  dilute hydrochloric acid that react together to produce a neutral solution.   show your working on the grid .  volume of aqueous sodium hydroxide = .. cm3  volume of dilute hydrochloric acid = .. cm3  [3]  (ii)  use your graph to determine the highest temperature reached if the volumes in (c)(i)  were mixed together.  highest temperature reached = ..  [2]",
            "6": "6 0620/63/m/j/20 \u00a9 ucles 2020  (iii)  which solution, aqueous sodium hydroxide or dilute hydrochloric acid, was the most  concentrated?   use your answer to (c)(i) to explain why.  most concentrated solution  .  explanation  .   .  [1]  (d)  on the graph, sketch the lines you would expect to obtain if a copper can was used instead of  a polystyrene cup. [2]  (e)  give one advantage and one disadvantage of using a burette, instead of a measuring cylinder,  to add the dilute hydrochloric acid directly into the polystyrene cup.   advantage  ..     disadvantage  .     [2]  (f)  how could the reliability of the results of this investigation be checked?      ..   [1]  [total: 19]",
            "7": "7 0620/63/m/j/20 \u00a9 ucles 2020 [turn over 3  two solids, solid n and solid p, were analysed.   tests were done on each solid.  tests on solid n   tests were done and the following observations made. tests on solid n observations solid n was dissolved in distilled water to  produce solution n. the solution was divided  into three equal portions in three boiling tubes. test 1 aqueous sodium hydroxide was added slowly  until\tin\texcess\tto\tthe\tfirst\tportion\tof\tsolution\t n.white precipitate formed, the precipitate dissolved in excess aqueous  sodium hydroxide forming a colourless solution test 2 aqueous ammonia was added slowly until in  excess to the second portion of solution n.white precipitate formed, the precipitate dissolved in excess aqueous  ammonia forming a colourless solution test 3 aluminium foil and aqueous sodium hydroxide  were added to the third portion of solution n.  the mixture was heated using a bunsen burner. any gas produced was tested with damp red  litmus paper.effervescence was seen, the damp red litmus paper turned blue  (a)  name the gas given off in test 3.   ..   [1]  (b)  identify solid n.      ..   [2]",
            "8": "8 0620/63/m/j/20 \u00a9 ucles 2020  tests on solid p   solid p was potassium iodide.   complete the expected observations.  (c)  describe the appearance of solid p.   ..   [1]  (d)\t\ta\tflame\ttest\twas\tdone\ton\tsolid\t p.  observations     [1]  (e)  solid p was dissolved in distilled water to produce solution p. solution p was divided into three  equal portions in three test-tubes.  (i)  about 1 cm depth of dilute nitric acid and a few drops of aqueous silver nitrate were added  to\tthe\tfirst\tportion\tof\tsolution\tp.  observations  ...   ...   [1]  (ii)  about 1 cm depth of dilute nitric acid and a few drops of aqueous barium nitrate were  added to the second portion of solution p.  observations  ...   ...   [1]  (iii)  a few drops of aqueous bromine were added to the third portion of solution p.  observations  ...   ...   [1]  [total: 8]",
            "9": "9 0620/63/m/j/20 \u00a9 ucles 2020 [turn over 4  stayclean and brightwhite are two brands of washing powder. both contain sodium carbonate.   sodium carbonate is soluble in water and reacts with dilute sulfuric acid to produce   carbon dioxide gas.   plan an investigation to determine which of the two washing powders, stayclean or brightwhite,    contains the greatest percentage of sodium carbonate.   you are provided with samples of the two washing powders and common laboratory apparatus and  chemicals.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "10": "10 0620/63/m/j/20 \u00a9 ucles 2020blank page",
            "11": "11 0620/63/m/j/20 \u00a9 ucles 2020blank page",
            "12": "12 0620/63/m/j/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w20_qp_11.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 11_0620_11/4rp   \u00a9 ucles 2020   [turn ove r   *3380125813*cambridge igcse\u2122       chemistry  0620/11     paper 1 multiple choice (core)  october/november 2020     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark. a mark will not be ded ucted for a wrong answer.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/11/o/n/20  1 \u2018the movement of a substance very slowly  from an area of high concentration to an area of low  concentration.\u2019    which process is being described?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air    2 what happens to the average speed of gas particles when pressur e and temperature are  increased?     average speed of particles  pressure increases temperature increases  a faster faster  b unchanged slower  c slower faster  d unchanged faster      3 which piece of apparatus can only measure a single fixed volume ?  a 250  cm3 beaker  b 5 0  cm3 burette  c 100  cm3 measuring cylinder  d 2 5  cm3 pipette    4 in the chromatography experiment shown, which label represents  the solvent front?    cdba      ",
            "3": "3     \u00a9 ucles 2020 0620/11/o/n/20 [turn over  5 which substances can be separated by filtration?  a insoluble liquid and water  b insoluble solid and water  c solution of soluble liquid in water  d solution of soluble solid in water      6 an atom of element r contains 15 protons, 16 neutrons and 15 el ectrons.    what is r?  a gallium  b phosphorus  c s u l f u r   d z i n c      7 which row describes the properties of potassium iodide, k i?     type of  bonding boiling  point solid conducts  electricity aqueous solution  conducts electricity  a covalent low no no  b covalent high no yes  c ionic high yes yes  d ionic high no yes      8 which diagram represents a mixture of compounds?    a b c d      ",
            "4": "4  \u00a9 ucles 2020 0620/11/o/n/20  9 rubidium is in group i of the periodic table and bromine is in  group vii.    rubidium reacts with bromine to form an ionic compound.    which row shows the electron change taking place for rubidium a nd the correct formula of the  rubidium ion?     electron change formula of ion formed a electron gained rb+  b electron gained rb\u2013  c electron lost rb+  d electron lost rb\u2013      10 which statement explains why graphite is used as a lubricant?  a all bonds between the atoms are weak.  b it conducts electricity.  c it has a low melting point.  d layers in the structure can slide over each other.     11 the equation for burning propane in air is shown.    c 3h8(g)  +  xo 2(g)  \uf0ae  3co 2(g)  +  yh 2o(g)     which values of x and y balance the equation?     x  y   a 3 4  b 4 8  c 5 4  d 10 8      12 the relative atomic mass of chlorine is 35.5.    when calculating relative atomic mass, which particle is the ma ss of a chlorine atom compared  to?  a a neutron  b a proton  c an atom of carbon-12  d an atom of hydrogen-1   ",
            "5": "5     \u00a9 ucles 2020 0620/11/o/n/20 [turn over  13 concentrated aqueous sodium chloride is electrolysed using plat inum electrodes.    what is the major product formed at each electrode?     anode cathode  a chlorine hydrogen  b chlorine sodium  c oxygen hydrogen  d oxygen sodium     14 three substances are listed.    1 copper  2 dilute sulfuric acid  3 solid lead( ii) bromide    which substances conduct electricity?  a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    15 sodium nitrate is added to water in a beaker and stirred until  it dissolves.    at the end of the experiment, the beaker feels cold.    which row describes the reaction?     temperature  of solution type of  reaction  a decreases endothermic  b decreases exothermic  c increases endothermic  d increases exothermic     16 which substance does not require oxygen in order to produce energy?  a coal  b hydrogen  c natural gas  d  235u    ",
            "6": "6  \u00a9 ucles 2020 0620/11/o/n/20  17 which process involves a physical change?  a heating calcium carbonate  b burning wood  c melting an ice cube  d mixing an acid and a base      18 a sign displayed in a flour mill is shown.    explosion hazard no smoking no openflamesdanger     which statement explains why there is a danger of explosion in a flour mill?  a flour burns very quickly because it is a fine powder.  b flour is a catalyst for combustion.  c flour mills get hot and speed up the rate of combustion.  d the combustion of flour is exothermic.    ",
            "7": "7     \u00a9 ucles 2020 0620/11/o/n/20 [turn over  19 the graph shows the results of two experiments investigating t he rate of reaction between   excess calcium carbonate and dilute hydrochloric acid.    in each experiment the volume of carbon dioxide produced is mea sured at fixed time intervals.    experiment 1 00volume of co2 timeexperiment 2     which statement describes the difference in conditions between experiments 1 and 2?  a in experiment 2 a higher concentration of dilute hydrochloric acid is used.  b in experiment 2 a higher temperature is used.  c in experiment 2 the mass of calcium carbonate is greater.  d in experiment 2 the particle size of calcium carbonate is grea ter.     20 when pink crystals of cobalt( ii) chloride are heated, steam is given off and the colour of the  solid  changes to blue.    coc l 2\u20226h 2o    coc l 2  +  6h 2o    what happens when water is added to the blue solid?     colour temperature  a changes to pink decreases  b changes to pink increases   c remains blue decreases   d remains blue increases     ",
            "8": "8  \u00a9 ucles 2020 0620/11/o/n/20  21 in which change is the sulfur, s, in sulfur( i) oxide, s 2o, reduced?    so3 so2 ss2o soa cb d       22 what is a characteristic of acids?  a acids turn methyl orange indicator yellow.  b acids have a high ph value.  c acids react with ammonium salts to give ammonia gas.  d acids react with carbonates to produce salts.      23 four different groups of oxides are shown.    1 mgo   feo   cuo  2 cao   so 2   tio 2  3 pbo   cao   c l 2o  4 no 2   br 2o   p 2o5    which statement about these oxides is correct?  a 1, 2 and 3 contain basic oxides only.  b 2, 3 and 4 contain basic oxides only.  c 1 contains basic oxides only and 4 contains acidic oxides only .  d 1 contains acidic oxides only and 4 contains basic oxides only .    ",
            "9": "9     \u00a9 ucles 2020 0620/11/o/n/20 [turn over  24 a student carries out an experiment to prepare pure magnesium s ulfate crystals.    the diagram shows the first stage of the preparation.    dilute sulfuric acidstirrer magnesium carbonate     he adds magnesium carbonate until no more reacts.    which process should he use for the next stage?  a crystallisation  b evaporation  c filtration  d neutralisation     25 which ion produces a green precipitate when aqueous sodium hyd roxide is added?  a cu 2+ b fe2+ c fe3+ d zn2+      26 the positions of four elements in the periodic table are shown.     which element is a gas that displaces iodine from sodium iodide ?    ab cd      ",
            "10": "10  \u00a9 ucles 2020 0620/11/o/n/20  27 a flammable gas needs to be removed from a tank at an industria l plant.    for safety reasons, an inert gas is used.    which gas is suitable?  a a r g o n   b hydrogen  c methane  d oxygen     28 a substance, x, has the following properties.    1 it has a high melting point.  2 it conducts electricity in the solid and liquid states. 3 it is malleable. 4 it has a high density.    what is x?  a a ceramic  b copper  c graphite  d sodium chloride     ",
            "11": "11     \u00a9 ucles 2020 0620/11/o/n/20 [turn over  29 a reactivity series is shown.    sodium  calcium  magnesium  carbon  zinc  iron  hydrogen  copper    which statement is correct?  a all the metals above carbon are extracted by electrolysis.  b iron can only be extracted by electrolysis.  c calcium can be extracted by heating calcium oxide with carbon.   d copper can only be extracted by passing hydrogen over heated c opper( ii) oxide.      30 what is the symbol of the metal used in the manufacture of airc raft because of its strength and  low density?  a a l b c u  c f e  d z n       31 oxides of nitrogen are given out from car exhausts.    which row best shows why oxides of nitrogen are unwanted in the  atmosphere?     acidic toxic  a no no  b no yes  c yes no  d yes yes     ",
            "12": "12  \u00a9 ucles 2020 0620/11/o/n/20  32 two reactions, m and n, both form carbon dioxide.    m  n   caco 3    co 2    ch 4    which types of reaction are m and n?     m  n   a thermal decomposition thermal decomposition  b thermal decomposition combustion  c combustion thermal decomposition  d combustion combustion      33 which row describes two uses of sulfur dioxide?     use 1 use 2  a bleaching paper pulp neutralising acidic industrial waste  b bleaching paper pulp preserving food and drink  c extracting iron from hematite neutralising acidic industrial wa ste  d extracting iron from hematite preserving food and drink     34 which statement about lime and limestone is correct?  a calcium oxide is formed from limestone in a displacement react ion.  b lime is used to treat alkaline soils.  c limestone is a waste material in the manufacture of iron.  d slaked lime is used in the process of flue gas desulfurisation .    35 which compound has a chemical name ending in \u2013ol  ?  a c 2h5oh b c 2h6 c c h 3cooh d c 2h4     ",
            "13": "13     \u00a9 ucles 2020 0620/11/o/n/20 [turn over  36 petroleum is separated into fractions by fractional distillati on.    separation occurs in a fractionating column.    some properties of three of these fractions are shown.    fraction boiling point  range  / \uf0b0c number of  carbon atoms in  the molecules  1  5  \u201310  2 320\u2013350 16\u201324  3 120\u2013210     which statement is correct?  a fraction 1 has a higher boiling point range than fraction 2.  b fraction 2 is removed from a higher point in the fractionating column than fraction 1.  c molecules in fraction 3 have shorter chains than those in fract ion 2.  d none of the fractions are liquid at room temperature.      37 which statement about alkenes is correct?  a alkenes are saturated hydrocarbons.  b alkenes can be made by cracking other hydrocarbon compounds.  c alkenes change bromine water from colourless to brown.  d alkene molecules contain double bonds between carbon atoms and  hydrogen atoms.      38 the flow chart shows the preparation of ethanol and some impor tant chemistry of ethanol.    ethanol carbon dioxide  +  substance z substance xprocess y fermentation     what are x, y and z?     x y z  a yeast combustion oxygen  b glucose combustion steam  c glucose polymerisation water  d yeast fermentation glucose     ",
            "14": "14  \u00a9 ucles 2020 0620/11/o/n/20  39 which statements about aqueous ethanoic acid are correct?    1 it is an alkane.  2 it reacts with sodium carbonate to form carbon dioxide.  3 it changes the colour of litmus solution from blue to red.  4 it is a hydrocarbon.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    40 which substance is a polymer?  a diamond  b g r a p h i t e   c nylon  d sodium chloride    ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.    cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2020 0620/11/o/n/20  blank page",
            "16": "16  \u00a9 ucles 2020 0620/11/o/n/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w20_qp_12.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 11_0620_12/4rp   \u00a9 ucles 2020   [turn ove r   *0995871257*cambridge igcse\u2122       chemistry  0620/12     paper 1 multiple choice (core)  october/november 2020     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark. a mark will not be ded ucted for a wrong answer.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/12/o/n/20  1 \u2018the movement of a substance very slowly  from an area of high concentration to an area of low  concentration.\u2019    which process is being described?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air     2 oxygen melts at \u2013219  \uf0b0c and boils at \u2013183  \uf0b0c.    at which temperature is oxygen a liquid?  a \u2013225  \uf0b0c b \u2013189  \uf0b0c c \u2013175  \uf0b0c d 25  \uf0b0c     3 which diagram shows a burette?    abcd      4 in the chromatography experiment shown, which label represents  the solvent front?    cdba      ",
            "3": "3     \u00a9 ucles 2020 0620/12/o/n/20 [turn over  5 different methods of separation rely on substances having diffe rent properties.    which property does distillation make use of?  a boiling point  b colour  c particle size  d solubility in different solvents     6 which statement about atomic structure is correct?  a isotopes have a different nucleon number but the same proton n umber.  b metal atoms gain electrons to achieve a noble gas electronic s tructure.  c the nucleon number is the total number of electrons and neutro ns in the nucleus of the  atom.  d protons and neutrons are oppositely charged particles.     7 which element is a non-metal?  a scandium  b s o d i u m   c strontium  d s u l f u r     8 the structure of propane, c 3h8, is shown.    h ch hhhhh c c h     how many electrons are involved in the bonding of propane?  a 8  b 1 0  c 1 6  d 20     ",
            "4": "4  \u00a9 ucles 2020 0620/12/o/n/20  9 rubidium is in group i of the periodic table and bromine is in  group vii.    rubidium reacts with bromine to form an ionic compound.    which row shows the electron change taking place for rubidium a nd the correct formula of the  rubidium ion?     electron change formula of ion formed a electron gained rb+  b electron gained rb\u2013  c electron lost rb+  d electron lost rb\u2013      10 which statement explains why graphite is used as a lubricant?  a all bonds between the atoms are weak.  b it conducts electricity.  c it has a low melting point.  d layers in the structure can slide over each other.      11 the formula of which compound contains the largest number of gr oup vii atoms?  a c 13h13io8 b c l 2o6 c a l (bro 3)3 d nafc 2h2o2     12 the relative atomic mass of chlorine is 35.5.    when calculating relative atomic  mass, which particle is the ma ss of a chlorine atom compared  to?  a a neutron  b a proton  c an atom of carbon-12  d an atom of hydrogen-1     ",
            "5": "5     \u00a9 ucles 2020 0620/12/o/n/20 [turn over  13 universal indicator solution is added to a neutral solution of concentrated aqueous sodium  chloride.    the solution, which contains h+ (hydrogen), na+ ( s o d i u m ) ,  c l \u2013 (chloride) and oh\u2013 (hydroxide)  ions, is electrolysed.    the product at the cathode is hydrogen gas and the product at t he anode is chlorine gas.    what happens to the colour of the indicator in the solution  during electrolysis?  a the colour changes from blue to green.  b the colour changes from blue to red.  c the colour changes from green to blue.  d the colour changes from green to red.     14 which energy level diagram represents an endothermic reaction?    energy progress of reactiona reactants productsenergy progress of reactionb reactantsproducts energy progress of reactionc reactants productsenergy progress of reactiond reactants products       15 which process is a physical change?  a burning a piece of magnesium  b dissolving calcium carbonate in hydrochloric acid  c melting an ice cube  d the rusting of an iron nail ",
            "6": "6  \u00a9 ucles 2020 0620/12/o/n/20  16 which substance does not require oxygen in order to produce energy?  a coal  b hydrogen  c natural gas  d 235u      17 nitrogen, n 2, and hydrogen, h 2, can be converted into ammonia, nh 3, using a catalyst.    what is the purpose of the catalyst?  a to increase the amount of ammonia produced  b to increase the rate of reaction  c to reduce the amount of reactants needed  d to reduce the rate of reaction    18 a reaction is carried out at four different temperatures.    the time taken for the reaction to complete at each temperature  is measured.    the results are shown.    70 605040302010 0time  / s temperature  / \u00b0c0 1 02 03 04 05 06 0     what is the relationship between temperature and rate of reacti on?  a the rate decreases as the temperature increases.  b the rate increases as the temperature increases.  c the rate is proportional to the temperature.  d the rate is inversely proportional to the temperature.    ",
            "7": "7     \u00a9 ucles 2020 0620/12/o/n/20 [turn over  19 during the manufacture of sulfuric acid, sulfur dioxide is conv erted to sulfur trioxide.    2so 2  +  o 2  \uf0ae  2so 3    which type of reaction is this?  a displacement  b neutralisation  c oxidation  d thermal decomposition      20 when pink crystals of cobalt( ii) chloride are heated, steam is given off and the colour of the  solid  changes to blue.    coc l 2\u20226h 2o    coc l 2  +  6h 2o    what happens when water is added to the blue solid?     colour temperature  a changes to pink decreases  b changes to pink increases   c remains blue decreases   d remains blue increases      21 which statement describes a base?  a it reacts with ammonium chloride to produce ammonia gas.  b it reacts with calcium carbonate to produce carbon dioxide gas .  c it reacts with copper to produce hydrogen gas.  d it turns blue litmus red.      22 which compound is an acidic oxide?  a aluminium oxide  b carbon dioxide  c copper( ii) oxide  d magnesium oxide     ",
            "8": "8  \u00a9 ucles 2020 0620/12/o/n/20  23 which statement describes how a flame test is done?  a the tip of a clean wire is dipped into the substance and the w ire is placed in a blue bunsen  burner flame.  b the tip of a clean wire is dipped into the substance and the w ire is placed in a yellow bunsen  burner flame.  c a wooden splint is lit and is placed above a test-tube contain ing the gas being tested.  d a wooden splint is lit, blown out and the glowing splint put i nto a test-tube of the gas being  tested.    24 a student carries out an experiment to prepare pure magnesium s ulfate crystals.    the diagram shows the first stage of the preparation.    dilute sulfuric acidstirrer magnesium carbonate     he adds magnesium carbonate until no more reacts.    which process should he use for the next stage?  a crystallisation  b evaporation  c filtration  d neutralisation     25 which row about elements in the periodic table is correct?     statement 1 statement 2  a   two elements in the same group  have similar chemical properties metals are on the  left of the table  b   two elements in the same group  have similar chemical properties metals are on the  right of the table  c   two elements in the same period  have similar chemical properties metals are on the  left of the table  d   two elements in the same period  have similar chemical properties metals are on the  right of the table    ",
            "9": "9     \u00a9 ucles 2020 0620/12/o/n/20 [turn over  26 tennessine, ts, is a newly discovered element.    the atomic number of tennessine is 117 and it is placed directl y underneath astatine in group vii  of the periodic table.    the trends in properties of group vii elements are shown.    element boiling point  / \uf0b0c colour density  in g  / cm3 reactivity  fluorine \u2013188 pale yellow 0.002 extremely high  chlorine \u201335 green 0.003 very high  bromine 60 red-brown 3.103 high  iodine 184 dark grey 4.933 low    which statement about the properties of tennessine is likely to  be correct?  a tennessine has a higher reactivity than astatine.  b tennessine has a lower boiling point than astatine.  c tennessine is a lighter colour than astatine.  d tennessine is more dense than astatine.     27 a flammable gas needs to be removed from a tank at an industria l plant.    for safety reasons, an inert gas is used.    which gas is suitable?  a a r g o n   b hydrogen  c methane  d oxygen    ",
            "10": "10  \u00a9 ucles 2020 0620/12/o/n/20  28 a substance, x, has the following properties.    1 it has a high melting point.  2 it conducts electricity in the solid and liquid states.  3 it is malleable.  4 it has a high density.    what is x?  a a ceramic  b copper  c graphite  d sodium chloride    29 which diagram best represents the structure of a substance tha t is a good conductor of electricity  at 25  \uf0b0c?    ab c d +\u2013+\u2013 \u2013+ +\u2013\u2013+ +\u2013      30 some properties of element y are listed.    \u25cf it reacts with hydrochloric acid to make hydrogen gas.  \u25cf it reacts with steam but not with cold water.  \u25cf the oxide of y cannot be reduced by carbon.    what is element y?  a copper  b iron  c magnesium  d sodium     ",
            "11": "11     \u00a9 ucles 2020 0620/12/o/n/20 [turn over  31 oxides of nitrogen are given out from car exhausts.    which row best shows why oxides of nitrogen are unwanted in the  atmosphere?     acidic toxic  a no no  b no yes  c yes no  d yes yes     32 water is purified using several processes.    four of the processes are listed.    1 chlorine is added to water to kill any bacteria.  2 water is passed through coarse gravel to remove large pieces of dirt.  3 water is passed through wire screens to remove large twigs.  4 water is passed through fine sand to remove small particles.    in which order are the processes carried out?  a 1  \uf0ae 2 \uf0ae 3 \uf0ae 4  b 2  \uf0ae 1 \uf0ae 4 \uf0ae 3  c 3  \uf0ae 2 \uf0ae 4 \uf0ae 1  d 4  \uf0ae 3 \uf0ae 2 \uf0ae 1     33 when solid s is heated strongly, it forms gas g.    g turns limewater cloudy.    what are s and g and which type of reaction does s undergo?     s g type of reaction  a calcium carbonate carbon dioxide combustion  b calcium carbonate carbon dioxide thermal decomposition  c sodium carbonate oxygen combustion  d sodium carbonate oxygen thermal decomposition     ",
            "12": "12  \u00a9 ucles 2020 0620/12/o/n/20  34 the element sulfur is found in a number of different minerals.    which mineral contains the greatest percentage by mass of sulfu r?  a barite, baso 4  b galena, pbs  c gypsum, caso 4  d pyrite, fes 2    35 which structure represents a molecule of ethanol?    hca h hch hhcb ch h oo h hhcc h hch ho h hcd h hc h      36 petroleum is separated into fractions by fractional distillati on.    separation occurs in a fractionating column.    some properties of three of these fractions are shown.    fraction boiling point  range  / \uf0b0c number of  carbon atoms in  the molecules  1  5  \u201310  2 320\u2013350 16\u201324  3 120\u2013210     which statement is correct?  a fraction 1 has a higher boiling point range than fraction 2.  b fraction 2 is removed from a higher point in the fractionating column than fraction 1.  c molecules in fraction 3 have shorter chains than those in fract ion 2.  d none of the fractions are liquid at room temperature.    ",
            "13": "13     \u00a9 ucles 2020 0620/12/o/n/20 [turn over  37 which statement describes methane?  a it is an alcohol.  b it is an unsaturated molecule.  c it contains carbon, hydrogen and oxygen atoms only.  d each molecule contains four single covalent bonds.      38 the flow chart shows the preparation of ethanol and some impor tant chemistry of ethanol.    ethanol carbon dioxide  +  substance z substance xprocess y fermentation     what are x, y and z?     x y z  a yeast combustion oxygen  b glucose combustion steam  c glucose polymerisation water  d yeast fermentation glucose      39 the structure of propane is shown.    hch hch hch hh     which statement about the atoms and the bonding in propane is c orrect?  a all the bonds are single bonds.  b each carbon atom only bonds with two hydrogen atoms.  c propane is an unsaturated molecule.  d there are three carbon-carbon bonds.    ",
            "14": "14  \u00a9 ucles 2020 0620/12/o/n/20  40 the structure of a compound x is shown.    hco o h    x is in the same homologous series as ethanoic acid.    which row describes some of the properties of an aqueous soluti on of x?     reacts with caco 3  to produce a gas neutralises  cuo turns methyl  orange red  a no no no  b no yes no  c yes yes yes  d yes no yes     ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.    cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2020 0620/12/o/n/20  blank page",
            "16": "16  \u00a9 ucles 2020 0620/12/o/n/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w20_qp_13.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 11_0620_13/4rp   \u00a9 ucles 2020   [turn ove r   *4297468909*cambridge igcse\u2122       chemistry  0620/13     paper 1 multiple choice (core)  october/november 2020     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark. a mark will not be ded ucted for a wrong answer.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/13/o/n/20  1 \u2018the movement of a substance very slowly  from an area of high concentration to an area of low  concentration.\u2019    which process is being described?  a a liquid being frozen  b a solid melting  c a substance diffusing through a liquid  d a substance diffusing through the air    2 when a dark grey solid element is heated, it changes directly i nto a purple gas.    which word describes this change?  a boiling  b evaporation  c melting  d sublimation     3 nickel( ii) sulfate is a green solid that is soluble in water.    which method is used to obtain a pure sample of nickel( ii) sulfate crystals from a mixture of  nickel( ii) sulfate and sand?  a heat the mixture with water and distil it to give nickel( ii) sulfate.  b heat the mixture with water and leave it to crystallise.  c heat the mixture with water and filter off the nickel( ii) sulfate.  d heat the mixture with water, filter and allow the solution to crystallise.    4 in the chromatography experiment shown, which label represents  the solvent front?    cdba      ",
            "3": "3     \u00a9 ucles 2020 0620/13/o/n/20 [turn over  5 what is the meaning of the term nucleon number ?  a the number of neutrons in the nucleus of an atom  b the number of protons in the nucleus of an atom  c the total number of protons and electrons in the nucleus of an  atom  d the total number of protons and neutrons in the nucleus of an atom      6 the diagram represents the structure of a solid.        what could the solid be?     brass graphite sodium chloride  a \u0016 \u0016 \u001a  b \u0016 \u001a \u001a  c \u001a \u0016 \u0016  d \u001a \u001a \u0016     7 magnesium reacts with sulfuric acid.    what are the formulae of the products formed in this reaction?  a m g s o 4 and h 2  b m g s o 4 and h 2o  c m g ( s o 4)2 and h 2  d m g ( s o 4)2 and h 2o    ",
            "4": "4  \u00a9 ucles 2020 0620/13/o/n/20  8 which diagram shows the arrangement of the outer shell electron s in a molecule of water?    oa h h ob h h oc h h od h h      9 rubidium is in group i of the periodic table and bromine is in  group vii.    rubidium reacts with bromine to form an ionic compound.    which row shows the electron change taking place for rubidium a nd the correct formula of the  rubidium ion?     electron change formula of ion formed a electron gained rb+  b electron gained rb\u2013  c electron lost rb+  d electron lost rb\u2013      10 which statement explains why graphite is used as a lubricant?  a all bonds between the atoms are weak.  b it conducts electricity.  c it has a low melting point.  d layers in the structure can slide over each other.     ",
            "5": "5     \u00a9 ucles 2020 0620/13/o/n/20 [turn over  11 the relative atomic mass of chlorine is 35.5.    when calculating relative atomic mass, which particle is the ma ss of a chlorine atom compared  to?  a a neutron  b a proton  c an atom of carbon-12  d an atom of hydrogen-1    12 molten sodium chloride is electrolysed using inert electrodes.    which row shows the products formed at the cathode and anode?     cathode anode  a chlorine hydrogen  b chlorine sodium  c hydrogen chlorine  d sodium chlorine      13 ethanol is used as a fuel.    ethanol  +  oxygen  \uf0ae  carbon dioxide  +  water    which statements are correct?    1 the reaction is endothermic.  2 the products have more energy than the reactants. 3 the oxygen for this reaction comes from the air.  4 the temperature of the reaction mixture rises during this rea ction.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     14 hydrogen and the isotope uranium-235 are both used to generate electricity.    which term describes the change that occurs for both  substances in this context?  a combustion  b endothermic  c exothermic  d decomposition     ",
            "6": "6  \u00a9 ucles 2020 0620/13/o/n/20  15 which substance does not require oxygen in order to produce energy?  a coal  b hydrogen  c natural gas  d 235u      16 when calcium carbonate reacts with dilute hydrochloric acid, ca rbon dioxide gas is given off.    this causes the reaction mixture to lose mass.    four separate experiments are performed.    the starting mass, and the mass after five minutes, are measure d for each reaction mixture.    in which experiment is carbon dioxide produced at the greatest rate?     starting  mass  / g mass after  five minutes  / g  a 14.37 11.89  b 16.52 15.29  c 16.76 14.12  d 16.99 15.21     17 silver oxide reacts with magnesium to make silver and magnesium  oxide.    ag 2o  +  mg  \uf0ae  2ag  +  mgo    which substance is oxidised in this reaction?  a magnesium  b magnesium oxide  c silver  d silver oxide    ",
            "7": "7     \u00a9 ucles 2020 0620/13/o/n/20 [turn over  18 when pink crystals of cobalt( ii) chloride are heated, steam is given off and the colour of the  solid  changes to blue.    coc l 2\u20226h 2o    coc l 2  +  6h 2o    what happens when water is added to the blue solid?     colour temperature  a changes to pink decreases  b changes to pink increases   c remains blue decreases   d remains blue increases      19 which oxide is used to neutralise acidic gases in a power stati on?  a calcium oxide  b carbon dioxide  c nitrogen oxide  d sulfur dioxide    20 period 3 of the periodic table contains the elements sodium to  argon.    element q is a non-metal from this period.    which statement about q is correct?  a it conducts electricity.  b it has a lower proton number than sodium.  c it has electrons in only three shells.  d it is malleable.     ",
            "8": "8  \u00a9 ucles 2020 0620/13/o/n/20  21 equal masses of a solid, x, are added in turn to an aqueous so lution, y.    the ph of the solution is measured after each addition until th e ph becomes 7. the readings are  plotted as shown.    12 7 2 0123456ph additions of x    what are x and y?     x  y   a cu(s) hc l (aq)  b mg(s) hc l (aq)  c nh 4cl (s) naoh(aq)  d zn(oh) 2(s) naoh(aq)      22 an aqueous cation reacts with aqueous sodium hydroxide to form a white precipitate.    the precipitate is insoluble in excess sodium hydroxide.    what is the aqueous cation?  a aluminium ion  b calcium ion  c chromium ion  d zinc ion      23 vinegar has a ph of 3.    which statement about vinegar is correct?  a it forms a salt with sulfuric acid.  b it reacts with some metals to form hydrogen gas.  c it reacts with ammonium compounds to give ammonia gas.  d it turns red litmus blue.   ",
            "9": "9     \u00a9 ucles 2020 0620/13/o/n/20 [turn over  24 a student carries out an experiment to prepare pure magnesium s ulfate crystals.    the diagram shows the first stage of the preparation.    dilute sulfuric acidstirrer magnesium carbonate     he adds magnesium carbonate until no more reacts.    which process should he use for the next stage?  a crystallisation  b evaporation  c filtration  d neutralisation     25 which statement about the halogens and their compounds is corre ct?  a the colour of the element gets lighter going down group vii.  b the elements get less dense going down group vii.  c when chlorine is added to sodium iodide solution, iodine is fo rmed.  d when iodine is added to sodium bromide solution, bromine is fo rmed.     26 which compound contains a transition metal ion and a halide io n?  a aluminium iodide  b calcium fluoride  c iron( iii) oxide  d nickel( ii) chloride     ",
            "10": "10  \u00a9 ucles 2020 0620/13/o/n/20  27 a flammable gas needs to be removed from a tank at an industria l plant.    for safety reasons, an inert gas is used.    which gas is suitable?  a a r g o n   b hydrogen  c methane  d oxygen     28 a substance, x, has the following properties.    1 it has a high melting point.  2 it conducts electricity in the solid and liquid states. 3 it is malleable. 4 it has a high density.    what is x?  a a ceramic  b copper  c graphite  d sodium chloride      29 a metal m is between sodium and magnesium in the reactivity ser ies.    which reactions occur with m and its oxide?     m reacts  with steam m can be extracted  by heating its oxide  with carbon  a no no  b no yes  c yes no  d yes yes     ",
            "11": "11     \u00a9 ucles 2020 0620/13/o/n/20 [turn over  30 mild steel and stainless steel are two alloys containing the el ement iron.    which row identifies a use of each alloy?     a use of mild steel a use of stainless steel  a car bodies cutlery  b car bodies electrical wiring  c food containers cutlery  d food containers electrical wiring     31 coke (carbon) and limestone are two raw materials used in the e xtraction of iron from hematite.    which type of reaction occurs when each substance is heated dur ing the process?     coke limestone  a redox redox  b redox thermal decomposition  c thermal decomposition redox  d thermal decomposition thermal decomposition     32 oxides of nitrogen are given out from car exhausts.    which row best shows why oxides of nitrogen are unwanted in the  atmosphere?     acidic toxic  a no no  b no yes  c yes no  d yes yes     ",
            "12": "12  \u00a9 ucles 2020 0620/13/o/n/20  33 two reactions, p and q, produce carbon dioxide.    c6h12o6 glucosena2co3 sodium carbonateco2pq     which types of reaction are p and q?     p  q   a neutralisation neutralisation  b neutralisation respiration  c respiration neutralisation  d respiration respiration     34 which gas is used as a food preservative?  a methane  b fluorine  c oxygen  d sulfur dioxide    35 which calcium compound does not neutralise an acid soil?  a calcium oxide  b calcium sulfate  c calcium hydroxide  d calcium carbonate    ",
            "13": "13     \u00a9 ucles 2020 0620/13/o/n/20 [turn over  36 petroleum is separated into fractions by fractional distillati on.    separation occurs in a fractionating column.    some properties of three of these fractions are shown.    fraction boiling point  range  / \uf0b0c number of  carbon atoms in  the molecules  1  5  \u201310  2 320\u2013350 16\u201324  3 120\u2013210     which statement is correct?  a fraction 1 has a higher boiling point range than fraction 2.  b fraction 2 is removed from a higher point in the fractionating column than fraction 1.  c molecules in fraction 3 have shorter chains than those in fract ion 2.  d none of the fractions are liquid at room temperature.      37 how many atoms are there in one molecule of ethanoic acid?  a 5  b 6  c 8  d 11    38 the flow chart shows the preparation of ethanol and some impor tant chemistry of ethanol.    ethanol carbon dioxide  +  substance z substance xprocess y fermentation     what are x, y and z?     x y z  a yeast combustion oxygen  b glucose combustion steam  c glucose polymerisation water  d yeast fermentation glucose      39 which substance is not a fraction obtained from the fractional distillation of petrol eum?  a ethene  b fuel oil  c naphtha  d refinery gas ",
            "14": "14  \u00a9 ucles 2020 0620/13/o/n/20  40 some plastics are non-biodegradable.    what is the meaning of the term non-biodegradable ?  a cannot be recycled for further use  b gives off greenhouse gases when burnt  c harmful to animals and plants  d not broken down by natural processes    ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.    cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2020 0620/13/o/n/20  blank page",
            "16": "16  \u00a9 ucles 2020 0620/13/o/n/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w20_qp_21.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 11_0620_21/5rp   \u00a9 ucles 2020   [turn ove r   *3070598259*cambridge igcse\u2122       chemistry 0620/21     paper 2 multiple choice (extended)  october/november 2020     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark. a mark will not be ded ucted for a wrong answer.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/21/o/n/20  1 which gas has the slowest rate of diffusion?  a h 2 b n h 3 c c h 4 d c o 2    2 a mixture of colourless amino acids is separated using chromato graphy.    the solvent used is propanol.    the chromatogram is sprayed with a locating agent.    which row describes the purpose of the propanol and the locatin g agent?     purpose of propanol purpose of locating agent  a   to make the individual  amino acids visible to prevent the amino acids  moving any further  b   to move the amino acids up  the chromatography paper to make the individual  amino acids visible  c   to move the amino acids up  the chromatography paper to prevent the amino acids  moving any further  d   to prevent the amino acids  moving too far up the paper to make the individual  amino acids visible    3 which piece of apparatus can only measure a single fixed volume ?  a 250  cm3 beaker  b 5 0  cm3 burette  c 100  cm3 measuring cylinder  d 2 5  cm3 pipette     4 in the chromatography experiment shown, which label represents  the solvent front?    cdba      ",
            "3": "3     \u00a9 ucles 2020 0620/21/o/n/20 [turn over  5 the atomic structure of four particles are shown.     electrons protons neutrons  p 18 17 18  q 18 17 20  r 17 17 18  s 17 17 20    which particles have the same chemical properties?  a p and r only b p and s c p, q and r d r and s     6 the arrangements of the electrons in two ions formed from elem ents x and y are shown.    n = 20 p = 19x n = 20 p = 17y     which equation represents the reaction between elements x and y ?  a x 2  +  2y  \uf0ae  2x+  +  2y\u2013  b x 2  +  2y  \uf0ae  2x\u2013  +  2y+  c 2x  +  y 2  \uf0ae  2x+  +  2y\u2013  d 2x  +  y 2  \uf0ae  2x\u2013  +  2y+    ",
            "4": "4  \u00a9 ucles 2020 0620/21/o/n/20  7 which diagram shows the outer shell electron arrangement in a molecule of methanol, ch 3oh?    c hh oa h hc hh ob h h c hh oc h hc hh od h h      8 which statement about silicon dioxide, sio 2, is correct?  a it conducts electricity because it contains free electrons.  b it is a macromolecule with four oxygen atoms bonded to each sil icon atom.  c it is a simple covalent molecule.  d its structure is similar to graphite.     9 rubidium is in group i of the periodic table and bromine is in  group vii.    rubidium reacts with bromine to form an ionic compound.    which row shows the electron change taking place for rubidium a nd the correct formula of the  rubidium ion?     electron change formula of ion formed a electron gained rb+  b electron gained rb\u2013  c electron lost rb+  d electron lost rb\u2013     ",
            "5": "5     \u00a9 ucles 2020 0620/21/o/n/20 [turn over  10 which statement explains why graphite is used as a lubricant?  a all bonds between the atoms are weak.  b it conducts electricity.  c it has a low melting point.  d layers in the structure can slide over each other.      11 sodium carbonate reacts with sulfuric acid to form carbon diox ide, water and a sodium salt.    an incomplete equation for the reaction is shown.    na2co 3  +  h 2so 4  \uf0ae  co 2  +  h 2o  +  ..    what is the formula of the sodium salt?  a na2(so 4)2 b na(so 4)2 c na2so 4 d naso 4     12 the relative atomic mass of chlorine is 35.5.    when calculating relative atomic mass, which particle is the ma ss of a chlorine atom compared  to?  a a neutron  b a proton  c an atom of carbon-12  d an atom of hydrogen-1     13 what is the empirical formula of an oxide of iron, formed by r eacting 2.24  g of iron with 0.96  g of  oxygen?  a feo b fe2o c fe2o3 d fe3o4     14 which reaction takes place at the cathode during the electroly sis of molten nickel( ii) chloride?  a cl 2  +  2e\u2013  \uf0ae  2c l \u2013  b 2c l \u2013  \uf0ae  c l 2  +  2e\u2013  c ni  \uf0ae  ni2+  +  2e\u2013  d ni2+  +  2e\u2013  \uf0ae  ni     ",
            "6": "6  \u00a9 ucles 2020 0620/21/o/n/20  15 sodium nitrate is added to water in a beaker and stirred until  it dissolves.    at the end of the experiment, the beaker feels cold.    which row describes the reaction?     temperature  of solution type of  reaction  a decreases endothermic  b decreases exothermic  c increases endothermic  d increases exothermic      16 which substance does not require oxygen in order to produce energy?  a coal  b hydrogen  c natural gas  d 235u     17 ethene reacts with hydrogen to form ethane.    cc + \u2192h hhh hh hc hh c hh h     the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013c +350  c\u2013h +410  h\u2013h +436  c=c +614    what is the energy change for the reaction?  a \u2013290  kj / mol  b \u2013120  kj / mol  c +120  kj / mol  d +290  kj / mol ",
            "7": "7     \u00a9 ucles 2020 0620/21/o/n/20 [turn over  18 a sign displayed in a flour mill is shown.    explosion hazard no smoking no openflamesdanger     which statement explains why there is a danger of explosion in a flour mill?  a flour burns very quickly because it is a fine powder.  b flour is a catalyst for combustion.  c flour mills get hot and speed up the rate of combustion.  d the combustion of flour is exothermic.    19 a student investigates the effect of concentration on the rate of reaction between  calcium carbonate and hydrochloric acid. he follows the method shown.    \u25cf place 1  g of calcium carbonate in a conical flask.  \u25cf add excess hydrochloric acid. \u25cf let the reaction continue until no more gas is made. \u25cf repeat the experiment with different concentrations of hydroc hloric acid.    which essential step has been left out of the method if he is t o work out the rate of the reaction?  a heating the reaction mixture  b placing a bung in the flask  c timing the reaction  d using a catalyst     ",
            "8": "8  \u00a9 ucles 2020 0620/21/o/n/20  20 the reaction between sulfur dioxide and oxygen is shown.    2so 2(g)  +  o 2(g)    2so 3(g)    the reaction is exothermic.    which of the changes shifts the position of equilibrium to the right?    1 increase the concentration of oxygen.  2 increase the pressure.  3 increase the temperature.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 only     21 the reaction between chlorine and bromide ions is a redox react ion.    cl  2  +  2br  \u2013  \uf0ae  2c l \u2013  +  br 2    what is the change in oxidation state of the reducing agent in this reaction?  a \u20132 to 0 b \u20131 to 0 c 0 to \u20131 d 0 to +1      22 what is a characteristic of acids?  a acids turn methyl orange indicator yellow.  b acids have a high ph value.  c acids react with ammonium salts to give ammonia gas.  d acids react with carbonates to produce salts.     23 zinc oxide is an amphoteric oxide.    which row describes the reactions of zinc oxide?     reaction  with alkalis reaction  with acids  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     ",
            "9": "9     \u00a9 ucles 2020 0620/21/o/n/20 [turn over  24 a student carries out an experiment to prepare pure magnesium s ulfate crystals.    the diagram shows the first stage of the preparation.    dilute sulfuric acidstirrer magnesium carbonate     he adds magnesium carbonate until no more reacts.    which process should he use for the next stage?  a crystallisation  b evaporation  c filtration  d neutralisation    25 elements p and q have the same number of electron shells.    q has more electrons in its outer shell than p.    which statements are correct?    1 p and q are in the same group of the periodic table.  2 p and q are in the same period of the periodic table. 3 p has a greater tendency to form positive ions than q. 4 the oxides of q are more basic than those of p.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     26 the positions of four elements in the periodic table are shown.     which element is a gas that displaces iodine from sodium iodide ?    ab cd    ",
            "10": "10  \u00a9 ucles 2020 0620/21/o/n/20  27 a flammable gas needs to be removed from a tank at an industria l plant.    for safety reasons, an inert gas is used.    which gas is suitable?  a a r g o n   b hydrogen  c methane  d oxygen     28 a strip of aluminium is placed into a test-tube containing aque ous lead( ii) nitrate and left for  several minutes.    aluminium is higher than lead in the reactivity series.    pb(no3)2 solutionstrip of aluminium no change     which statement explains why lead is not displaced by this strip of aluminium?  a a thin insoluble layer of aluminium nitrate forms on the alumi nium.  b nitrate ions are reduced in aqueous solution.  c the ionic bonds between lead and nitrate ions are too strong.  d there is an unreactive oxide layer on the aluminium.    29 which statements about the metal zinc are correct?    1 it is extracted from the ore bauxite.  2 it is used to galvanise steel. 3 it is used to make the alloy brass. 4 it reacts with dilute hydrochloric acid to produce hydrogen g as.    a 2 and 3 only b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4    30 what is the symbol of the metal used in the manufacture of airc raft because of its strength and  low density?  a a l b c u  c f e  d z n    ",
            "11": "11     \u00a9 ucles 2020 0620/21/o/n/20 [turn over  31 ammonia is manufactured using the haber process.    which statement about this process is correct?  a the catalyst used for this reaction is vanadium pentoxide.  b the hydrogen used is extracted from air.  c using a high pressure increases the yield of ammonia.  d using a high temperature increases the yield of ammonia.    32 iron can be protected from rusting by attaching a piece of a mo re reactive metal, e.g. magnesium,  to the iron.    which equation represents the reaction that takes place?  a f e ( s )   \uf0ae  fe 2+(aq)  +  2e\u2013  b f e2+(aq)  +  2e\u2013  \uf0ae  fe(s)  c m g ( s )   \uf0ae  mg2+(aq)  +  2e\u2013  d m g2+(aq)  +  2e\u2013  \uf0ae  mg(s)     33 which row describes two uses of sulfur dioxide?     use 1 use 2  a bleaching paper pulp neutralising acidic industrial waste  b bleaching paper pulp preserving food and drink  c extracting iron from hematite neutralising acidic industrial wa ste  d extracting iron from hematite preserving food and drink     ",
            "12": "12  \u00a9 ucles 2020 0620/21/o/n/20  34 part of the carbon cycle is shown.    glucosecombustion pq co2r plant ch4     what are processes p, q and r?     p  q  r   a decomposition respiration photosynthesis  b respiration photosynthesis decomposition  c respiration decomposition photosynthesis  d photosynthesis respiration decomposition     ",
            "13": "13     \u00a9 ucles 2020 0620/21/o/n/20 [turn over  35 the structures of four organic molecules are shown.    c h hc h hh c hch c h hhh h h hc c hcch h hc hh hh hh hh hh hhh cc h c ch hc hhc hh hc hh hch c hh hch h1 32 4     which molecules are structural isomers of structure 1?  a 2 and 4 b 2  o n l y  c 3 and 4 d 3  o n l y      36 which chemical equation for the substitution of an alkane with chlorine is correct?  a c 3h8  +  c l 2  \uf0ae  c3h7cl  +  hc l  b c 3h6  +  c l 2  \uf0ae  c3h6cl 2  c c 3h8  +  c l 2  \uf0ae  c3h6cl 2  +  h 2  d c 3h6  +  c l 2  \uf0ae  c3h5cl  +  hc l     ",
            "14": "14  \u00a9 ucles 2020 0620/21/o/n/20  37 propene is an alkene that reacts with bromine, steam and hydro gen as shown.    c c chh h h h h brominesteamhydrogen jk l    what are the products of these reactions?     j  k  l   a bromopropane propanol butane  b dibromopropane propanoic acid propane  c dibromopropane propanol propane  d bromopropane propanoic acid butane      38 the flow chart shows the preparation of ethanol and some impor tant chemistry of ethanol.    ethanol carbon dioxide  +  substance z substance xprocess y fermentation     what are x, y and z?     x y z  a yeast combustion oxygen  b glucose combustion steam  c glucose polymerisation water  d yeast fermentation glucose     39 which statements about aqueous ethanoic acid are correct?    1 it is an alkane.  2 it reacts with sodium carbonate to form carbon dioxide. 3 it changes the colour of litmus solution from blue to red. 4 it is a hydrocarbon.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for each series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.    cambridge assessment international education is part of the cam bridge assessment group. cambridge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2020 0620/21/o/n/20  40 the structure of a polymer is shown.    nc hc ch3hh     which monomer forms this polymer?  a ethane  b ethene  c propane  d propene    ",
            "16": "16  \u00a9 ucles 2020 0620/21/o/n/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w20_qp_22.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 11_0620_22/4rp   \u00a9 ucles 2020   [turn ove r   *4506129529*cambridge igcse\u2122       chemistry  0620/22     paper 2 multiple choice (extended)  october/november 2020     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark. a mark will not be ded ucted for a wrong answer.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/22/o/n/20  1 which gas has the slowest rate of diffusion?  a h 2 b n h 3 c c h 4 d c o 2    2 a chromatography experiment is carried out to analyse the pigm ents present in four different  types of leaf. the student carrying out the experiment forgot t o complete his table of results,  which is shown.    plant  leaf number of  pigments  identified colour of  identified  pigments distance  travelled by  the solvent  front (cm) distance travelled  from the origin by  each pigment (cm) rf value  maple f green  / yellow 3.7 green: 3.0  yellow: 3.1 green: 0.81  yellow: 0.83  laurel 2 green  / yellow g green: 2.5  yellow: 2.5 green: 0.78  yellow: 0.78  lime 3 green  / yellow  / orange 3.5 green: 2.9  yellow: 3.0  orange: 2.7 green: 0.83  yellow: 0.86  yellow: 0.77  ash 3 green  / yellow  / orange 3.5 green: 2.8  yellow: 3.0  orange: 2.7 green: 0.80  yellow: h  orange: 0.77    which row identifies the values of f, g and h?     f g h  a 2 3.2 0.80  b 3 3.5 0.83  c 2 3.2 0.86  d 3 3.5 0.78      3 which statement about isotopes is correct?  a they have different proton numbers.  b they have different chemical properties.  c they have the same nucleon number.  d they have the same number of electrons in their outer shell.     ",
            "3": "3     \u00a9 ucles 2020 0620/22/o/n/20 [turn over  4 in the chromatography experiment shown, which label represents  the solvent front?    cdba       5 different methods of separation rely on substances having diffe rent properties.    which property does distillation make use of?  a boiling point  b colour  c particle size  d solubility in different solvents     6 the arrangements of the electrons in two ions formed from elem ents x and y are shown.    n = 20 p = 19x n = 20 p = 17y     which equation represents the reaction between elements x and y ?  a x 2  +  2y  \uf0ae  2x+  +  2y\u2013  b x 2  +  2y  \uf0ae  2x\u2013  +  2y+  c 2x  +  y 2  \uf0ae  2x+  +  2y\u2013  d 2x  +  y 2  \uf0ae  2x\u2013  +  2y+    ",
            "4": "4  \u00a9 ucles 2020 0620/22/o/n/20  7 which row identifies compounds that contain single covalent bo nds only, double covalent bonds  only or both single and double covalent bonds?     single covalent bonds  only double covalent bonds  only both single and  double covalent bonds  a c2h4 c h 3oh co 2  b ch 3oh c 2h4 c o 2  c ch 3oh co 2 c 2h4  d co 2 c 2h4 c h 3oh     8 ethyl methanoate, hcooc 2h5, burns in excess oxygen to produce carbon dioxide and water.     the equation is shown.    2hcooc 2h5  +  xo 2  \uf0ae  6co 2  +  6h 2o    what is the value of x?  a 2  b 7  c 9  d 18      9 rubidium is in group i of the periodic table and bromine is in  group vii.    rubidium reacts with bromine to form an ionic compound.    which row shows the electron change taking place for rubidium a nd the correct formula of the  rubidium ion?     electron change formula of ion formed a electron gained rb+  b electron gained rb\u2013  c electron lost rb+  d electron lost rb\u2013      10 which statement explains why graphite is used as a lubricant?  a all bonds between the atoms are weak.  b it conducts electricity.  c it has a low melting point.  d layers in the structure can slide over each other.     ",
            "5": "5     \u00a9 ucles 2020 0620/22/o/n/20 [turn over  11 the relative atomic mass of chlorine is 35.5.    when calculating relative atomic mass, which particle is the ma ss of a chlorine atom compared  to?  a a neutron  b a proton  c an atom of carbon-12  d an atom of hydrogen-1    12 universal indicator solution is added to a neutral solution of concentrated aqueous sodium  chloride.    the solution, which contains h + (hydrogen), na+ ( s o d i u m ) ,  c l \u2013 (chloride) and oh\u2013 (hydroxide)  ions, is electrolysed.    the product at the cathode is hydrogen gas and the product at t he anode is chlorine gas.    what happens to the colour of the indicator in the solution  during electrolysis?  a the colour changes from blue to green.  b the colour changes from blue to red.  c the colour changes from green to blue.  d the colour changes from green to red.    13 what is the empirical formula of an oxide of iron, formed by r eacting 2.24  g of iron with 0.96  g of  oxygen?  a feo b fe2o c fe2o3 d fe3o4     14 the combustion of methane is exothermic.    ch 4  +  2o 2  \uf0ae  co 2  +  2h 2o    which statement about this reaction is correct?  a the energy needed to break the bonds in methane and oxygen is greater than the energy  released in making new bonds in carbon dioxide and water.  b the energy needed to break the bonds in methane and oxygen is less than the energy  released in making new bonds in carbon dioxide and water.  c the energy released in breaking bonds in methane and oxygen is  greater than the energy  needed to make new bonds in carbon dioxide and water.  d the energy released in breaking bonds in methane and oxygen is  less than the energy  needed to make new bonds in carbon dioxide and water.    ",
            "6": "6  \u00a9 ucles 2020 0620/22/o/n/20  15 hydrogen reacts with oxygen in a fuel cell.    2h2  +  o 2  \uf0ae  2h 2o    the reaction is exothermic.    286  kj of energy is released for every mole of water formed.    which volume of hydrogen gas, measured at room temperature and pressure, would react with  oxygen with the release of 7000  j of energy?  a 587  cm3 b 1 1 7 5  cm3 c 5 8 7  dm3 d 1175  dm3     16 which substance does not require oxygen in order to produce energy?  a coal  b hydrogen  c natural gas  d  235u    17 nitrogen, n 2, and hydrogen, h 2, can be converted into ammonia, nh 3, using a catalyst.    what is the purpose of the catalyst?  a to increase the amount of ammonia produced  b to increase the rate of reaction  c to reduce the amount of reactants needed  d to reduce the rate of reaction    18 ammonia is produced by the haber process. the equation is show n.    n 2(g)  +  3h 2(g)    2nh 3(g)    the forward reaction is exothermic.    which statement is correct?  a increasing pressure decreases the yield of ammonia, but speeds up the reaction.  b increasing temperature decreases the yield of ammonia, but spee ds up the reaction.  c increasing the concentration of hydrogen and nitrogen results i n a lower yield of ammonia.  d increasing the temperature increases the yield of ammonia and s peeds up the reaction.    ",
            "7": "7     \u00a9 ucles 2020 0620/22/o/n/20 [turn over  19 during the manufacture of sulfuric acid, sulfur dioxide is conv erted to sulfur trioxide.    2so 2  +  o 2  \uf0ae  2so 3    which type of reaction is this?  a displacement  b neutralisation  c oxidation  d thermal decomposition      20 the equation for a redox reaction is shown.    2feso 4  +  c l 2  +  h 2so 4  \uf0ae  fe 2(so 4)3  +  2hc l    which element is reduced?  a chlorine  b iron  c oxygen  d s u l f u r     21 the equation shows a reaction between aqueous hydrogen bromide and aqueous ammonia.    hbr(aq)  +  nh 3(aq)  \uf0ae  nh 4+(aq)  +  br\u2013(aq)    which statement describes the role of aqueous hydrogen bromide?   a it is a catalyst.  b it is a reducing agent.  c it is a proton acceptor.  d it is a proton donor.    22 the equations for three reactions are shown.    1 pb(no 3)2(aq)  +  2k i(aq)  \uf0ae  pb i2(s)  +  2kno 3(aq)  2 2agno 3(aq)  +  cu i2(aq)  \uf0ae  cu(no 3)2(aq)  +  2ag i(s)  3 cuo(s)  +  h 2so 4(aq)  \uf0ae  cuso 4(aq)  +  h 2o(l)    which reactions are suitable for making a salt by precipitation ?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    ",
            "8": "8  \u00a9 ucles 2020 0620/22/o/n/20  23 zinc oxide is an amphoteric oxide.    which row describes the reactions of zinc oxide?     reaction  with alkalis reaction  with acids  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a      24 a student carries out an experiment to prepare pure magnesium s ulfate crystals.    the diagram shows the first stage of the preparation.    dilute sulfuric acidstirrer magnesium carbonate     he adds magnesium carbonate until no more reacts.    which process should he use for the next stage?  a crystallisation  b evaporation  c filtration  d neutralisation    25 which row about elements in the periodic table is correct?     statement 1 statement 2  a   two elements in the same group  have similar chemical properties metals are on the  left of the table  b   two elements in the same group  have similar chemical properties metals are on the  right of the table  c   two elements in the same period  have similar chemical properties metals are on the  left of the table  d   two elements in the same period  have similar chemical properties metals are on the  right of the table   ",
            "9": "9     \u00a9 ucles 2020 0620/22/o/n/20 [turn over  26 a new element oxfordium, ox, was discovered with the following properties.    solubility electrical  conduction formula  of element bonding in a  molecule of ox 2  insoluble in water doesn\u2019t conduct ox 2 o x ox    in which group of the periodic table should the new element be placed?  a group iii  b group v  c group vii  d group viii     27 a flammable gas needs to be removed from a tank at an industria l plant.    for safety reasons, an inert gas is used.    which gas is suitable?  a a r g o n   b hydrogen  c methane  d oxygen    28 transition elements can have variable oxidation states.    which pair of compounds shows a  transition element in two diffe rent oxidation states?  a c r 2o3 and cr 2(so 4)3  b c u 2o and cuco 3  c zns and znso 4  d nio and ni(no 3)2     ",
            "10": "10  \u00a9 ucles 2020 0620/22/o/n/20  29 which diagram best represents the structure of a substance tha t is a good conductor of electricity  at 25  \uf0b0c?    ab c d +\u2013+\u2013 \u2013+ +\u2013\u2013+ +\u2013      30 why is aluminium metal unreactive with air?  a it is covered with a layer of oxide.  b it is low in the reactivity series.  c it is produced by electrolysis of its oxide.  d it melts at a high temperature.     31 the apparatus used for the extraction of aluminium oxide by el ectrolysis is shown.    carbon lining as cathodecarbon anodes + \u2013 molten aluminium collects at the bottomsolution of aluminium oxidein molten cryolite     which equation represents a reaction taking place at the anode?   a o  +  2e\u2013  \uf0ae  o2\u2013  b 2 o2\u2013  \uf0ae  o 2  +  4e\u2013  c a l 3\u2013  \uf0ae  a l  +  3e\u2013  d a l 3+  +  3e\u2013  \uf0ae  a l     ",
            "11": "11     \u00a9 ucles 2020 0620/22/o/n/20 [turn over  32 the results of tests on solid s and its aqueous solution are s hown.    tests on solid s tests on aqueous solution of s  effect of heat effect of aqueous  sodium hydroxide effect of  aqueous ammonia  brown gas given off,  together with a gas which  relights a glowing splint white ppt., soluble in  excess, giving a  colourless solution white ppt., soluble in  excess, giving a  colourless solution    what is s?  a aluminium nitrate  b aluminium sulfate  c zinc sulfate  d zinc nitrate    33 part of the carbon cycle is shown.    glucosecombustion pq co2r plant ch4     what are processes p, q and r?     p  q  r   a decomposition respiration photosynthesis  b respiration photosynthesis decomposition  c respiration decomposition photosynthesis  d photosynthesis respiration decomposition     34 the element sulfur is found in a number of different minerals.    which mineral contains the greatest percentage by mass of sulfu r?  a barite, baso 4  b galena, pbs  c gypsum, caso 4  d pyrite, fes 2 ",
            "12": "12  \u00a9 ucles 2020 0620/22/o/n/20  35 which structure represents a molecule of ethanol?    hca h hch hhcb ch h oo h hhcc h hch ho h hcd h hc h     36 which structures are structural isomers of each other?    1 hch hch hch hch hh2 hch hch h hch ch hh 34 hch h hch hch ch hh h hch hch hch ch hh     a 1, 2, 3 and 4  b 1, 2 and 4 only  c 1 and 3 only  d 2 and 4 only    37 which molecule is not produced by an addition reaction of ethene?  a c h 3ch 3 b c h 2brch 2br c c h 3ch 2oh d c h 3ch 2ch 3     ",
            "13": "13     \u00a9 ucles 2020 0620/22/o/n/20  38 the flow chart shows the preparation of ethanol and some impor tant chemistry of ethanol.    ethanol carbon dioxide  +  substance z substance xprocess y fermentation     what are x, y and z?     x y z  a yeast combustion oxygen  b glucose combustion steam  c glucose polymerisation water  d yeast fermentation glucose     39 which statement about nylon and terylene  is correct?  a nylon and terylene  are made from monomers with c=c bonds.  b nylon and terylene  contain the same linkage.  c nylon is a polyester.  d terylene  is made from two different monomers.     40 which diagram represents the structure of a protein?    a b o h n d c o hn co h n co co c hn hno co c o co c ooo co c o c o o      ",
            "14": "14  \u00a9 ucles 2020 0620/22/o/n/20  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.    cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2020 0620/22/o/n/20  blank page",
            "16": "16  \u00a9 ucles 2020 0620/22/o/n/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w20_qp_23.pdf": {
            "1": "    this document has 16 pages. blank pages are indicated.  ib20 11_0620_23/4rp   \u00a9 ucles 2020   [turn ove r   *7788486228*cambridge igcse\u2122       chemistry  0620/23     paper 2 multiple choice (extended)  october/november 2020     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark. a mark will not be ded ucted for a wrong answer.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2020 0620/23/o/n/20  1 which gas has the slowest rate of diffusion?  a h 2 b n h 3 c c h 4 d c o 2    2 when a dark grey solid element is heated, it changes directly i nto a purple gas.    which word describes this change?  a boiling  b evaporation  c melting  d sublimation     3 nickel( ii) sulfate is a green solid that is soluble in water.    which method is used to obtain a pure sample of nickel( ii) sulfate crystals from a mixture of  nickel( ii) sulfate and sand?  a heat the mixture with water and distil it to give nickel( ii) sulfate.  b heat the mixture with water and leave it to crystallise.  c heat the mixture with water and filter off the nickel( ii) sulfate.  d heat the mixture with water, filter and allow the solution to crystallise.    4 in the chromatography experiment shown, which label represents  the solvent front?    cdba      ",
            "3": "3     \u00a9 ucles 2020 0620/23/o/n/20 [turn over  5 molecules containing only non-metal atoms are covalently bonde d.    the formulae of four covalently bonded molecules are given belo w:    1 nitrogen, n 2  2 carbon dioxide, co 2  3 ethene, c 2h4  4 methanol, ch 3oh    which of the molecules contain double bonds?  a 1 and 4 b 2 and 3 c 2 and 4 d 4 only     6 the arrangements of the electrons in two ions formed from elem ents x and y are shown.    n = 20 p = 19x n = 20 p = 17y     which equation represents the reaction between elements x and y ?  a x 2  +  2y  \uf0ae  2x+  +  2y\u2013  b x 2  +  2y  \uf0ae  2x\u2013  +  2y+  c 2x  +  y 2  \uf0ae  2x+  +  2y\u2013  d 2x  +  y 2  \uf0ae  2x\u2013  +  2y+     7 magnesium reacts with sulfuric acid.    what are the formulae of the products formed in this reaction?  a m g s o 4 and h 2  b m g s o 4 and h 2o  c m g ( s o 4)2 and h 2  d m g ( s o 4)2 and h 2o     ",
            "4": "4  \u00a9 ucles 2020 0620/23/o/n/20  8 sodium reacts with chlorine  to form sodium chloride.    which row describes the bonding in the three substances?     sodium chlorine sodium chloride  a covalent covalent covalent  b covalent metallic ionic  c metallic covalent ionic  d metallic metallic covalent     9 rubidium is in group i of the periodic table and bromine is in  group vii.    rubidium reacts with bromine to form an ionic compound.    which row shows the electron change taking place for rubidium a nd the correct formula of the  rubidium ion?     electron change formula of ion formed a electron gained rb+  b electron gained rb\u2013  c electron lost rb+  d electron lost rb\u2013      10 which statement explains why graphite is used as a lubricant?  a all bonds between the atoms are weak.  b it conducts electricity.  c it has a low melting point.  d layers in the structure can slide over each other.    11 the relative atomic mass of chlorine is 35.5.    when calculating relative atomic mass, which particle is the ma ss of a chlorine atom compared  to?  a a neutron  b a proton  c an atom of carbon-12  d an atom of hydrogen-1     ",
            "5": "5     \u00a9 ucles 2020 0620/23/o/n/20 [turn over  12 what is the empirical formula of an oxide of iron, formed by r eacting 2.24  g of iron with 0.96  g of  oxygen?  a feo b fe2o c fe2o3 d fe3o4    13 electrolysis is carried out on dilute aqueous potassium bromid e.    which products are formed at the anode and the cathode?     anode cathode  a bromine hydrogen  b bromine potassium  c hydrogen bromine  d hydrogen potassium      14 which substance does not require oxygen in order to produce energy?  a coal  b hydrogen  c natural gas  d 235u     15 ethanol is used as a fuel.    ethanol  +  oxygen  \uf0ae  carbon dioxide  +  water    which statements are correct?    1 the reaction is endothermic.  2 the products have more energy than the reactants.  3 the oxygen for this reaction comes from the air.  4 the temperature of the reaction mixture rises during this rea ction.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     ",
            "6": "6  \u00a9 ucles 2020 0620/23/o/n/20  16 the reaction between hydrogen and oxygen releases 486  kj / mol of energy.    2h2(g)  +  o 2(g)  \uf0ae  2h 2o(g)    the bond energy of h\u2013h is 436  kj / mol and that of h\u2013o is 464  kj / mol.    what is the bond energy of o=o?  a 430  kj / mol  b 458  kj / mol  c 498  kj / mol  d 984  kj / mol     17 which reaction of hydrochloric acid is a redox reaction?  a 2na  +  2hc l  \uf0ae  2nac l  +  h 2  b n a 2o  +  2hc l  \uf0ae  2nac l  +  h 2o  c naoh  +  hc l  \uf0ae  nac l  +  h 2o  d n a 2co 3  +  2hc l  \uf0ae  2nac l  +  h 2o  +  co 2      18 which reaction is an example o f a photochemical reaction?  a glucose forming carbon dioxide and water  b magnesium reacting with oxygen  c potassium reacting with water  d silver chloride forming silver metal     ",
            "7": "7     \u00a9 ucles 2020 0620/23/o/n/20 [turn over  19 an excess of calcium carbonate is added to dilute hydrochloric acid, x.    the carbon dioxide gas given off is collected and its volume re corded at regular time intervals.    line x on the graph shows the results obtained.    the experiment is repeated using dilute hydrochloric acid, y.    line y on the graph shows the results obtained.    80 604020 0 0 50 100 time  / svolume of gas  / cm3 150 200xy     which statement about the two hydrochloric acid samples, x and y, is correct?  a they had the same volume but y had higher concentration.  b they had the same concentration but y had a larger volume.  c x had a higher concentration but y had a larger volume.  d y had a higher concentration but x had a larger volume.    20 period 3 of the periodic table contains the elements sodium to  argon.    element q is a non-metal from this period.    which statement about q is correct?  a it conducts electricity.  b it has a lower proton number than sodium.  c it has electrons in only three shells.  d it is malleable.     ",
            "8": "8  \u00a9 ucles 2020 0620/23/o/n/20  21 which metal has variable oxidation states?  a aluminium  b calcium  c copper  d s o d i u m       22 an aqueous cation reacts with aqueous sodium hydroxide to form a white precipitate.    the precipitate is insoluble in excess sodium hydroxide.    what is the aqueous cation?  a aluminium ion  b calcium ion  c chromium ion  d zinc ion     23 zinc oxide is an amphoteric oxide.    which row describes the reactions of zinc oxide?     reaction  with alkalis reaction  with acids  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a     ",
            "9": "9     \u00a9 ucles 2020 0620/23/o/n/20 [turn over  24 a student carries out an experiment to prepare pure magnesium s ulfate crystals.    the diagram shows the first stage of the preparation.    dilute sulfuric acidstirrer magnesium carbonate     he adds magnesium carbonate until no more reacts.    which process should he use for the next stage?  a crystallisation  b evaporation  c filtration  d neutralisation     25 which statement about the halogens and their compounds is corre ct?  a the colour of the element gets lighter going down group vii.  b the elements get less dense going down group vii.  c when chlorine is added to sodium iodide solution, iodine is fo rmed.  d when iodine is added to sodium bromide solution, bromine is fo rmed.    26 elements in group ii of the periodic table show the same trends  in their reaction with water and  their density as group i.    which row shows how the properties of barium compare with calci um?     reaction  with water density  a faster higher  b faster lower  c slower higher  d slower lower     ",
            "10": "10  \u00a9 ucles 2020 0620/23/o/n/20  27 a flammable gas needs to be removed from a tank at an industria l plant.    for safety reasons, an inert gas is used.    which gas is suitable?  a a r g o n   b hydrogen  c methane  d oxygen     28 an experiment is performed to determine the order of reactivity  of metals x and y compared to  lead.    strips of each metal were added to separate test-tubes containi ng aqueous lead( ii) nitrate,  pb(no 3)2.    the results are shown.    metal xpb(no3)2(aq) metal ydark laye r no change     what is the order of reactivity, least reactive first?  a p b  \uf0ae x \uf0ae y  b x  \uf0ae y \uf0ae pb  c x  \uf0ae pb \uf0ae y  d y  \uf0ae pb \uf0ae x     ",
            "11": "11     \u00a9 ucles 2020 0620/23/o/n/20 [turn over  29 the equation for the reaction between iron( iii) oxide and carbon monoxide is shown.    fe2o3  +  xco  \uf0ae  yfe  +  zco 2    which values of x, y and z balance the equation?     x  y  z   a 2 2 2  b 2 3 3  c 3 1 3  d 3 2 3     30 which process is used to separate oxygen from liquid air?  a chromatography  b distillation  c filtration  d fractional distillation     31 what is the catalyst in the haber process?  a f e  b n i  c p t  d v 2o5     32 ammonia is manufactured in an exothermic reaction.    n 2(g)  +  3h 2(g)    2nh 3(g)    what is the effect of lowering the pressure on the rate of form ation of ammonia and percentage  yield of ammonia at equilibrium?     rate of formation percentage yield  a decreases decreases  b decreases increases  c increases decreases  d increases increases     ",
            "12": "12  \u00a9 ucles 2020 0620/23/o/n/20  33 part of the carbon cycle is shown.    glucosecombustion pq co2r plant ch4     what are processes p, q and r?     p  q  r   a decomposition respiration photosynthesis  b respiration photosynthesis decomposition  c respiration decomposition photosynthesis  d photosynthesis respiration decomposition      34 which row shows the conditions used for the manufacture of sulf uric acid in the contact process?     pressure  / atm temperature  / \uf0b0c catalyst  a 250 200 vanadium( v) oxide  b 2 450 vanadium( v) oxide  c 250 200 iron  d 2 450 iron     35 which calcium compound does not neutralise an acid soil?  a calcium oxide  b calcium sulfate  c calcium hydroxide  d calcium carbonate     36 which product is obtained when bromine reacts with propene, ch 3ch=ch 2?  a c h 3ch=chbr  b c h 3cbr=chbr  c c h 3ch 2chbr 2  d c h 3chbrch 2br   ",
            "13": "13     \u00a9 ucles 2020 0620/23/o/n/20 [turn over  37 propanol is oxidised by acidified potassium manganate( vii) in a similar way to ethanol.    which compound is produced by the oxidation of propanol with ac idified potassium  manganate( vii)?  a c h 3ch 2oh  b c h 3ch 2ch 2oh  c c h 3cooh  d c h 3ch 2cooh     38 the flow chart shows the preparation of ethanol and some impor tant chemistry of ethanol.    ethanol carbon dioxide  +  substance z substance xprocess y fermentation     what are x, y and z?     x y z  a yeast combustion oxygen  b glucose combustion steam  c glucose polymerisation water  d yeast fermentation glucose      39 which equation represents the formation of poly(propene) from p ropene?    nc hc hh na c hch3 ch3 c hh nc hh c hhnb c hh c hh nc hc hh nc c hch3 ch3 c hhc hc hh hc hh n nd c hch3 c hh      ",
            "14": "14  \u00a9 ucles 2020 0620/23/o/n/20  40 which type of linkage joins the amino acids in a protein?    a co nc c hbc c oo od      ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.    cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2020 0620/23/o/n/20  blank page",
            "16": "16  \u00a9 ucles 2020 0620/23/o/n/20   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w20_qp_31.pdf": {
            "1": "*7501565664* chemistry  0620/31 paper 3 theory (core) october/november 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 11_0620_31/3rp \u00a9 ucles 2020 [turn overthis document has 16 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/31/o/n/20 \u00a9 ucles 2020 1 (a)  the diagram shows part of the periodic table. iii iiiivvviviiviii mg ca cr fe cuznal cl br ino fneh k   answer the following questions using only the symbols of the elements in the diagram.   each symbol may be used once, more than once or not at all.   state the symbol of the element that:  (i)  is a monoatomic gas at room temperature   ...   [1]  (ii)  is a liquid at room temperature   ...   [1]  (iii)  forms a stable ion of type x2\u2013   ...   [1]  (iv)  is extracted from hematite   ...   [1]  (v)  forms an ion whose aqueous solution gives a grey\u2011green precipitate on addition of aqueous  ammonia.   ...   [1]",
            "3": "3 0620/31/o/n/20 \u00a9 ucles 2020 [turn over  (b)  magnesium has several naturally occurring isotopes.  (i)  state the meaning of the term isotopes .   .   ...   [2]  (ii)  an isotope of magnesium is shown. 26mg12   deduce the number of protons and neutrons in this isotope.   number of protons  ..   number of neutrons    [2]  (c)  complete the electronic structure of a magnesium atom. mg  [1]  [total: 10]",
            "4": "4 0620/31/o/n/20 \u00a9 ucles 2020 2  the table shows the mass of air pollutants, in nanograms, in 1000 cm3 samples of air taken over a  four month period. mass of pollutant in 1000 cm3 of air / nanograms monthoxides of nitrogensulfur dioxidecarbon monoxideozone particulates april 108.2 0.6 1.3 24.6 17.8 may 121.6 1.8 1.6 23.2 19.2 june 126.7 1.6 1.9 22.8 20.0 july 163.9 4.5 2.2 20.1 22.0  (a)  answer these questions using only the information in the table.  (i)  name the pollutant that shows a decrease in concentration between april and july.   ...   [1]  (ii)  name the pollutant present in the lowest concentration in may.   ...   [1]  (iii)  calculate the mass of sulfur dioxide in 250 cm3 of the sample of air taken in april.  .. nanograms  [1]  (b)  oxides of nitrogen are produced when oxygen combines with nitrogen during thunderstorms.  (i)  state one other source of oxides of nitrogen in the air.   ...   [1]  (ii)  give one adverse effect of oxides of nitrogen on health.   ...   [1]  (iii)  complete the chemical equation for the reaction of nitrogen with oxygen to form  nitrogen dioxide.    +  2o2  \u2192  ..no2 [2]",
            "5": "5 0620/31/o/n/20 \u00a9 ucles 2020 [turn over  (c)  particulates are tiny solid particles in the air.   the movement of these particles is shown by the arrows in the diagram.   state the name given to this random motion of particles.   ..   [1]  [total: 8]",
            "6": "6 0620/31/o/n/20 \u00a9 ucles 2020 3  some properties of four substances, a, b, c and d, are shown in the table. substance strengthductility (how easy it is to pull into a wire)hardnessconductivity of heat a weak poor hard poor b strong not ductile very hard good c very strong very good hard good d weak poor soft good   answer these questions using only the information in the table.  (a)  state which substance, a, b, c or d, is best used in the core of an overhead electricity cable.   explain your answer.   substance  ..  explanation       [3]  (b)  state which substance, a, b, c or d, is best used for the tip of a drill.   explain your answer.   substance  ..   explanation       [3]  [total: 6]",
            "7": "7 0620/31/o/n/20 \u00a9 ucles 2020 [turn over 4  the structure of tartaric acid is shown. cc ho o h oh hoc ch o o h  (a) (i)  on the structure, draw a circle around one alcohol functional group. [1]  (ii)  deduce the formula of tartaric acid to show the number of carbon, hydrogen and oxygen  atoms.   ...   [1]  (iii)  complete the table to calculate the relative molecular mass of tartaric acid.   use your periodic table to help you. type of atomnumber of atomsrelative atomic mass carbon 12 hydrogen 6 1 6 \u00d7 1 = 6 oxygen 16  relative molecular mass = ..  [2]  (b)  acids react with bases such as calcium hydroxide.  (i)  complete the word equation for the reaction of nitric acid with calcium hydroxide. nitric acid +calcium hydroxide +  [2]  (ii)  an aqueous solution of calcium hydroxide is alkaline.   identify which one of these ph values represents the ph of an alkaline solution.   draw a circle around the correct answer.  ph 1            ph 4            ph 7            ph 10  [1]",
            "8": "8 0620/31/o/n/20 \u00a9 ucles 2020  (iii)  one way of determining ph is to use a ph meter.   describe one other way of determining ph.   .   ...   [2]  (iv)\t\tfarmers\tspread\tcalcium\thydroxide\t(slaked\tlime)\ton\tfields\twhere\tcrops\tare\tgrown.   explain why.   .   ...   [1]  (c)  calcium carbonate undergoes thermal decomposition. caco3  \u2192  cao  +  co2  (i)  state the meaning of the term thermal decomposition .   .   ...   [2]  (ii)  complete the energy level diagram for the thermal decomposition of calcium carbonate by  writing these words on the diagram:  \u25cfreactant  \u25cfproducts. energy progress of reaction  [1]  (iii)  explain, using information on the energy level diagram, how you know that this reaction is  endothermic.   ...   [1]  [total: 14]",
            "9": "9 0620/31/o/n/20 \u00a9 ucles 2020 [turn over 5  ethene is an alkene.  (a)  draw the structure of ethene to show all of the atoms and all of the bonds.  [1]  (b)  ethene reacts with aqueous bromine.   state the colour change observed when ethene reacts with aqueous bromine.  from . to  ...   [2]  (c)  ethene reacts with steam.  (i)  name and give the formula of the product of this reaction.   name  ...   formula    [2]  (ii)  identify the type of chemical reaction that occurs when ethene reacts with steam.   draw a circle around the correct answer.  addition            fermentation            polymerisation            neutralisation  [1]  (d)  alkenes are produced by cracking hydrocarbons.   complete the chemical equation for the cracking of the hydrocarbon, c16h34, to produce an  alkene and one other product.  c16h34  \u2192  c6h12  +  . [1]",
            "10": "10 0620/31/o/n/20 \u00a9 ucles 2020  (e)  poly(ethene) is produced by combining many ethene molecules.  (i)  name the general term used to describe the small molecules which combine to form a  polymer.    ...   [1]  (ii)  nylon is a polymer.   state one use for nylon.   ...   [1]  (iii)  describe one pollution problem caused by non\u2011biodegradable plastics.   ...   [1]  [total: 10]",
            "11": "11 0620/31/o/n/20 \u00a9 ucles 2020 [turn over 6  electrolysis is used to extract metals from metal compounds.  (a)  describe the electrolysis of molten lead( ii) bromide.   in your answer include:  \u25cf a labelled diagram of the apparatus used  \u25cf the names of the products formed at the positive and the negative electrodes.   positive electrode  ...   negative electrode  .  [5]  (b)  use the kinetic particle model to describe the arrangement and motion of the particles in  molten (liquid) lead.   arrangement  ..   motion    [2]  (c)  lead is a metal which is soft and has a relatively low melting point.   state two other physical properties of metals such as lead.  1  .  2  .  [2]  (d)  lead is formed when red lead oxide, pb3o4, is heated with carbon. pb3o4  +  4c  \u2192  3pb  +  4co   explain how this equation shows that pb3o4 has been reduced.   ..   [1]  [total: 10]",
            "12": "12 0620/31/o/n/20 \u00a9 ucles 2020 7  catalysts increase the rate of chemical reactions.  (a)  name the type of metals often used as catalysts.   ..   [1]  (b)  a student investigated the reaction of zinc powder with excess dilute hydrochloric acid in the  absence of a catalyst. zn  +  2hcl  \u2192  zncl 2  +  h2   the student measured the volume of hydrogen gas produced at 10 second intervals.   the graph shows the results. 120 100 80 60 40 20 0 01 02 03 0 time  / svolume of hydrogen / cm3 40 50 70 60   answer these questions using information from the graph.  (i)\t\tdeduce\tthe \tvolume\tof\thydrogen\tproduced\tin\tthe\tfirst\t25\tseconds\tof\tthe\texperiment.  volume = .. cm3  [1]  (ii)  explain why no more hydrogen is produced after 50 seconds.   ...   [1]",
            "13": "13 0620/31/o/n/20 \u00a9 ucles 2020 [turn over  (iii)  the experiment is repeated using a catalyst.   draw a line on the grid to show how the volume of hydrogen changes with time when a  catalyst is used.   all other conditions stay the same. [2]  (iv)  describe what effect the following changes have on the rate of the reaction.  \u25cf the concentration of hydrochloric acid is decreased.   all other conditions stay the same.   ..  \u25cf large pieces of zinc are used.   all other conditions stay the same.   ..  [2]  (c) (i)  describe a test for hydrogen.  test  ..   result  ...  [2]  (ii)  state one use of hydrogen.   ...   [1]  [total: 10]",
            "14": "14 0620/31/o/n/20 \u00a9 ucles 2020 8  this question is about metals and compounds of metals.  (a)  identify two correct statements about transition elements.   tick two boxes.   all transition elements are metals which are brown in colour.   transition elements have high densities.   compounds of transition elements are white in colour.   transition elements have high melting points.   transition elements are found between groups iv and v of   the periodic table.  [2]  (b)  the table compares the ease of reduction of some metal oxides with carbon. metal oxide ease of reduction with carbon cobalt( ii) oxide reduced at 450 \u00b0c copper( ii) oxide reduced below 450 \u00b0c magnesium oxide reduced above 1400 \u00b0c manganese( ii) oxide reduced at 1400 \u00b0c   put the four metals in order of their reactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]",
            "15": "15 0620/31/o/n/20 \u00a9 ucles 2020permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (c)  crystals of copper( ii) sulfate, cuso4\u20225h2o, can be prepared by heating excess copper( ii) oxide  powder with dilute sulfuric acid.  (i)  describe how to prepare a sample of pure dry copper( ii) sulfate crystals after the reaction  is complete.   in your answer describe how to:  \u25cf remove the excess copper( ii) oxide from the reaction mixture  \u25cf crystallise the copper( ii) sulfate  \u25cf dry the crystals.   .   .   .   .   .   .   .   ...   [4]  (ii)  identify the word that best describes copper( ii) sulfate.   draw a circle around the correct answer.  acid            halogen             polymer            salt [1]  (d)  a few drops of water are added to a sample of solid anhydrous copper( ii) sulfate, cuso4.  (i)  the reaction is reversible. cuso4  +  5h2o    cuso4\u20225h2o   draw in the box, the sign for a reversible reaction. [1]  (ii)  state the colour change observed when water is added to anhydrous copper( ii) sulfate.  from . to     [2]  [total: 12]",
            "16": "16 0620/31/o/n/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w20_qp_32.pdf": {
            "1": "*8830014055* chemistry  0620/32 paper 3 theory (core) october/november 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 11_0620_32/2rp \u00a9 ucles 2020 [turn overthis document has 20 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/32/o/n/20 \u00a9 ucles 2020 1 (a)  the diagram shows part of the periodic table. iii iiiivvv iviiviii ca fe ptznal cl brar ico f k   answer the following questions using only the symbols of the elements in the diagram.   each symbol may be used once, more than once or not at all.   state the symbol of the element that:  (i)  provides an inert atmosphere in lamps   ...   [1]  (ii)  forms an oxide which is used to neutralise acidic industrial waste   ...   [1]  (iii)  has an atom which forms a stable ion by the loss of one electron   ...   [1]  (iv)  is a metal used as an inert electrode   ...   [1]  (v)  forms an ion whose aqueous solution gives a green precipitate on addition of aqueous  sodium hydroxide.   ...   [1]",
            "3": "3 0620/32/o/n/20 \u00a9 ucles 2020 [turn over  (b)  chlorine is an element.  (i)  state the meaning of the term element .   .   ...   [1]  (ii)  an isotope of chlorine is shown. 35cl17   deduce the number of protons and neutrons in this isotope.   number of protons  ..   number of neutrons    [2]  (c)  complete the electronic structure of a chlorine atom. cl  [1]  [total: 9]",
            "4": "4 0620/32/o/n/20 \u00a9 ucles 2020 2  the table shows the mass of air pollutants, in nanograms, in 1000 cm3 samples of air taken over a  four month period.  mass of pollutant in 1000 cm3 of air / nanograms monthoxides of nitrogensulfur dioxidecarbon monoxideozone particulates april 144.3 5.9 2.5 33.9 21.9 may 114.2 2.0 2.1 39.6 21.7 june 110.2 6.1 1.8 31.5 21.3 july 115.4 2.5 2.6 24.2 19.0  (a)  answer these questions using only the information in the table.  (i)  name the pollutant that shows a continual decrease in concentration between april and  july.   ...   [1]  (ii)  name the pollutant present in the lowest concentration in may.    ...   [1]  (iii)  calculate the mass of carbon monoxide in 200 cm3 of the sample of air taken in april.  .. nanograms  [1]  (b)  sulfur dioxide contributes to acid rain.  (i)  state one source of the sulfur dioxide in the air.   ...   [1]  (ii)  give one adverse effect of acid rain on buildings.   ...   [1]  (iii)  state one use of sulfur dioxide.   ...   [1]",
            "5": "5 0620/32/o/n/20 \u00a9 ucles 2020 [turn over  (c)  sulfur dioxide is oxidised to sulfur trioxide, so3.  (i)  complete the chemical equation for this reaction.  ..so2  +  o2  \u2192  ..so3 [2]  (ii)  complete the energy level diagram for the oxidation of sulfur dioxide to sulfur trioxide by  writing these words on the diagram:  \u25cf reactants  \u25cf products. energy progress of reaction  [1]  (iii)  explain, using information on the energy level diagram, how you know that this reaction is  exothermic.   ...   [1]  (d)  nitrogen monoxide is a catalyst in the oxidation of sulfur dioxide to sulfur trioxide.   state the meaning of the term catalyst.   ..   [1]  (e)  sulfur trioxide reacts with water to form dilute sulfuric acid.   identify which one of these ph values represents the ph of dilute sulfuric acid.   draw a circle around the correct answer.  ph 2            ph 7            ph 9            ph 13 [1]",
            "6": "6 0620/32/o/n/20 \u00a9 ucles 2020  (f)  particulates are tiny solid particles in the air.   they show brownian motion.   identify one statement that best describes brownian motion.   tick one box.   the particles move from a higher concentration  to a lower concentration.   the particles are smaller than oxygen molecules.   brownian motion is an example of diffusion.   the particles move in a random zig-zag motion.  [1]  [total: 13]",
            "7": "7 0620/32/o/n/20 \u00a9 ucles 2020 [turn over 3  some properties of four substances, e, f, g and h, are shown in the table. substance strengthductility (how easy it is to pull into a wire)electrical conductivity when solidresistance to corrosion e very strong good good very good f weak good good poor g strong not ductile good poor h strong very good very good good   answer these questions using only the information in the table.  (a)  state which substance, e, f, g or h, is best used to make electricity cables.   explain your answer.   substance  ..   explanation       [3]  (b)  state which substance, e, f, g or h, is best used for making cutlery.   explain your answer.   substance  ..   explanation       [3]  [total: 6]",
            "8": "8 0620/32/o/n/20 \u00a9 ucles 2020 4  the structure of compound j is shown. c c ooc hc hh h h hh cco hh h  (a) (i)  on the structure, draw a circle around the carboxylic acid functional group. [1]  (ii)  deduce the formula of compound j to show the number of carbon, hydrogen and oxygen  atoms.   ...   [1]  (iii)  complete the table to calculate the relative molecular mass of compound j.   use your periodic table to help you. type of atomnumber of atomsrelative atomic mass carbon 12 hydrogen 10 1 10 \u00d7 1 = 10 oxygen 16  relative molecular mass = ..  [2]  (b)  acids react with bases such as calcium oxide.   complete the word equation for the reaction of hydrochloric acid with calcium oxide. hydrochloric acid+calcium oxide +  [2]",
            "9": "9 0620/32/o/n/20 \u00a9 ucles 2020 [turn over  (c)  the chemical equation for the reaction of lime (calcium oxide) with ammonium sulfate is shown. cao  +  (nh4)2so4  \u2192  caso4  +  2nh3  +  h2o  (i)  name the compound with the formula caso4.   ..    [1]  (ii)  complete these phrases about ammonia, nh3, using words from the list. acid            blue            gaseous            green            liquid pink            solid             solution             white   the state of ammonia at room temperature is .. .   aqueous ammonia turns damp red litmus paper .. .  [2]  [total: 9]",
            "10": "10 0620/32/o/n/20 \u00a9 ucles 2020 5  ethane is an alkane.  (a)  draw the structure of ethane to show all of the atoms and all of the bonds.  [1]  (b)  complete the chemical equation for the complete combustion of propane.  c3h8  +  5o2  \u2192  ..co2  +  ..h2o [2]  (c)  methane is an alkane which is produced by the fractional distillation of petroleum.  (i)  state one other process which puts methane into the atmosphere.   ...   [1]  (ii)  give one major use of methane.   ...   [1]  (d)  alkanes and alkenes are hydrocarbons.   state the meaning of the term hydrocarbon .      ..   [2]  (e)  alkanes and alkenes can be distinguished by a chemical test.   name the reagent that can be used to distinguish between alkanes and alkenes.   ..   [1]  (f)  alkenes are manufactured by cracking alkanes.  (i)  name an element that is also produced by cracking alkanes.   ...   [1]  (ii)  state one condition required for cracking alkanes.   ...   [1]  [t otal: 10]",
            "11": "11 0620/32/o/n/20 \u00a9 ucles 2020 [turn over 6  electrolysis is used to extract reactive metals from metal compounds.  (a)  describe the electrolysis of molten sodium chloride.   in your answer include:  \u25cf a labelled diagram of the apparatus used  \u25cf the observations made at the positive and the negative electrode.   observation at positive electrode      observation at negative electrode     [5]  (b)  use the kinetic particle model to describe the arrangement and separation of the particles in  solid sodium.  arrangement  ..  separation  ..  [2]",
            "12": "12 0620/32/o/n/20 \u00a9 ucles 2020  (c)  sodium is a metal in group i of the periodic table.   iron is a transition element.   give two ways in which the physical properties of iron differ from the physical properties of  sodium.   1  .  2  .  [2]  (d)  the chemical equation for the reaction between iron( iii) oxide and carbon monoxide is shown. fe2o3  +  3co  \u2192  2fe  +  3co2   explain how this equation shows that carbon monoxide has been oxidised.   ..   [1]  [total: 10]",
            "13": "13 0620/32/o/n/20 \u00a9 ucles 2020 [turn over 7  a student investigated the rate of decomposition of hydrogen peroxide, h2o2, in the presence of a  catalyst by measuring the volume of oxygen released at 10 second intervals. 2h2o2  \u2192  2h2o  +  o2  (a)  complete the diagram to show a suitable method for collecting and measuring the volume of  the oxygen.   label your diagram. hydrogen peroxide + catalyst  [3]",
            "14": "14 0620/32/o/n/20 \u00a9 ucles 2020  (b)  the graph shows how the volume of oxygen changes as the reaction proceeds. 120 100 80 60 40 20 0 01 02 03 0 time  / svolume of oxygen / cm3 40 50 70 60   answer these questions using information from the graph.  (i)  describe how the rate of this reaction changes with time.   ...   [1]  (ii)  deduce the time taken to collect 60 cm3 of oxygen.  time = .. s  [1]  (iii)  the experiment is repeated without using a catalyst.   draw a line on the grid to show how the volume of oxygen changes with time when no  catalyst is used.   all other conditions stay the same. [1]  (iv)  describe what effect an increase in temperature has on the rate of this reaction.   all other conditions stay the same.   ...   [1]",
            "15": "15 0620/32/o/n/20 \u00a9 ucles 2020 [turn over  (c)  identify which one of these elements is likely to act as a catalyst in chemical reactions.   draw a circle around the correct answer.  c            mg            na            ni            s [1]  (d)  describe a test for oxygen.  test  .  result  ..  [2]  [total: 10]",
            "16": "16 0620/32/o/n/20 \u00a9 ucles 2020 8  this question is about metals and compounds of metals.  (a)  iron reacts with dilute hydrochloric acid to form an iron( ii) salt and a gas which pops with a  lighted splint.   complete the word equation for this reaction. iron +hydrochloric acid +  [2]  (b)  identify two correct statements about iron.   tick two boxes.   iron forms an alloy called steel.   the commonest ore of iron is called bauxite.   iron is usually extracted from its ore by electrolysis.   iron is oxidised by carbon in the blast furnace.   both oxygen and water are needed for iron to rust.  [2]  (c)  the table compares the reactions of four metals with warm water and with steam. metalreaction with warm waterreaction with steam chromium no reaction slow reaction copper no reaction no reaction iron very slow reaction slow reaction magnesium very slow reaction rapid reaction   put the four metals in order of their reactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]",
            "17": "17 0620/32/o/n/20 \u00a9 ucles 2020 [turn over  (d)  crystals of cobalt( ii) chloride, cocl 2\u20226h2o, can be prepared by reacting excess  cobalt( ii) carbonate powder with dilute hydrochloric acid.   describe how to prepare a sample of pure dry cobalt( ii) chloride crystals after the reaction is  complete.   in your answer describe how to:  \u25cf remove the excess cobalt( ii) carbonate from the reaction mixture  \u25cf crystallise the cobalt( ii) chloride  \u25cf dry the crystals.                        ..   [4]  (e)  a few drops of water were added to a sample of solid anhydrous cobalt( ii) chloride, cocl 2.   the equation for the reaction is shown. cocl 2  +  6h2o    cocl 2\u20226h2o  (i)  state the meaning of the symbol .   ...   [1]  (ii)  state the colour change observed when water is added to anhydrous cobalt( ii) chloride.  from . to     [2]  [total: 13]",
            "18": "18 0620/32/o/n/20 \u00a9 ucles 2020blank page",
            "19": "19 0620/32/o/n/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/32/o/n/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w20_qp_33.pdf": {
            "1": "*5149603912* chemistry  0620/33 paper 3 theory (core) october/november 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 11_0620_33/2rp \u00a9 ucles 2020 [turn overthis document has 20 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/33/o/n/20 \u00a9 ucles 2020 1 (a)  the diagram shows part of the periodic table. iii iiiivvviviiviii cah ptal cl brar ino f k   answer the following questions using only the symbol of the elements in the diagram.   each symbol may be used once, more than once or not at all.   state the symbol of the element that:  (i)  is a fuel which is a gas at room temperature   ...   [1]  (ii)  is used to kill bacteria in water   ...   [1]  (iii)  forms a stable ion of type x3+   ...   [1]  (iv)  is a grey\u2011black non\u2011metallic solid at room temperature   ...   [1]  (v)  forms an ion which, on addition of aqueous sodium hydroxide, gives a white precipitate  which is soluble in excess aqueous sodium hydroxide.   ...   [1]",
            "3": "3 0620/33/o/n/20 \u00a9 ucles 2020 [turn over  (b)  sulfur has several isotopes.  (i)  identify one correct statement about isotopes.   tick one box.   they are molecules with the same number of neutrons   but different numbers of protons.   they are atoms with the same number of protons but   different numbers of neutrons.   they are molecules with the same number of protons   but different numbers of electrons.   they are atoms with the same number of neutrons but   different numbers of protons.  [1]  (ii)  an isotope of sulfur is shown. 33s16   deduce the number of protons and neutrons in this isotope.   number of protons  ..   number of neutrons    [2]  (c)  complete the electronic structure of a sulfur atom. s  [1]  [total: 9]",
            "4": "4 0620/33/o/n/20 \u00a9 ucles 2020 2  the table shows the mass of air pollutants, in nanograms, in 1000 cm3 samples of air taken over a  four month period. mass of pollutant in 1000 cm3 of air / nanograms monthoxides of nitrogensulfur dioxidecarbon monoxideozone particulates august 106.0 3.0 2.1 29.5 18.5 september 147.5 5.5 2.4 21.1 35.5 october 179.3 3.5 2.0 20.3 22.5 november 214.0 3.6 2.6 12.8 29.4  (a)  answer these questions using only the information in the table.  (i)  name the pollutant that shows a decrease in concentration between august and november.   ...   [1]  (ii)  calculate the mass of oxides of nitrogen in 250 cm3 of the sample of air taken in august.  .. nanograms  [1]  (b)  carbon monoxide is produced by the incomplete combustion of fossil fuels.  (i)  state the meaning of the term incomplete combustion .   .   ...   [1]  (ii)  give one adverse effect of carbon monoxide on health.   ...   [1]  (c)  carbon monoxide is also produced when methane reacts with steam in the presence of a  catalyst.  (i)  explain why a catalyst is used in this reaction.   ...   [1]  (ii)  methane is an air pollutant.   state one source of methane in the air.   ...   [1]",
            "5": "5 0620/33/o/n/20 \u00a9 ucles 2020 [turn over  (d) (i)  complete the chemical equation for the reaction of carbon monoxide with oxygen.  ..co  +  o2  \u2192  ..co2 [2]  (ii)  complete the energy level diagram for the reaction of carbon monoxide with oxygen by  writing these words on the diagram:  \u25cf reactants  \u25cf products. energy progress of reaction  [1]  (iii)  explain, using information on the energy level diagram, how you know that this reaction is  exothermic.   ...   [1]  (e) (i)  describe a test for carbon dioxide.   test  ..   result  ...  [2]  (ii)  identify which one of these ph values represents the ph of a solution of carbon dioxide in  water.   draw a circle around the correct answer.  ph 6            ph 7            ph 8            ph 14 [1]  [total: 13]",
            "6": "6 0620/33/o/n/20 \u00a9 ucles 2020 3  some properties of four substances, a, b, c and d, are shown in the table. substanceelectrical conductivity when solidelectrical conductivity when moltenmelting pointsolubility in water a does not conduct does not conduct low insoluble b conducts conducts high insoluble c does not conduct does not conduct very high soluble d does not conduct conducts high soluble   answer these questions using only the information in the table.  (a)  state which substance, a, b, c or d, is sulfur.   explain your answer.   substance  ..   explanation       [3]  (b)  state which substance, a, b, c or d, is sodium chloride.   explain your answer.   substance  ..  explanation       [3]  [total: 6]",
            "7": "7 0620/33/o/n/20 \u00a9 ucles 2020 [turn over 4  the structure of crotonic acid is shown. c hcch hooh h ch  (a) (i)  on the structure, draw a circle around the functional group which shows that this is an  unsaturated compound. [1]  (ii)  deduce the formula of crotonic acid to show the number of carbon, hydrogen and oxygen  atoms.   ...   [1]  (iii)  complete the table to calculate the relative molecular mass of crotonic acid.   use your periodic table to help you. type of atomnumber of atomsrelative atomic mass carbon 4 12 4 \u00d7 12 = 48 hydrogen 1 oxygen 16  relative molecular mass = ..  [2]  (b)  acids react with bases such as calcium oxide.   complete the word equation for the reaction of nitric acid with calcium oxide. nitric acid+calcium oxide +  [2]",
            "8": "8 0620/33/o/n/20 \u00a9 ucles 2020  (c)  calcium oxide is manufactured from limestone by thermal decomposition.  (i)  give the name of the main chemical compound in limestone.   ...   [1]  (ii)  state the meaning of the term thermal decomposition .   .   ...   [2]  (d)  calcium oxide reacts with water to produce slaked lime.   state one use of slaked lime.      ..   [1]  [total: 10]",
            "9": "9 0620/33/o/n/20 \u00a9 ucles 2020 [turn over 5  the formula of ethanol is c2h6o.  (a)  draw the structure of ethanol to show all of the atoms and all of the bonds.  [2]  (b)  ethanol is a liquid at room temperature.   describe the motion and separation of the particles in ethanol.   motion     separation  ..  [2]  (c)  name the two products formed when ethanol undergoes complete combustion.  1  .  2  .  [2]  (d)  ethanol can be manufactured by the fermentation of glucose.   one condition is using enzymes in yeast.  (i)  state two other conditions for fermentation.  1  ..  2  ..  [2]  (ii)  name the method used to separate the ethanol from the reaction mixture after fermentation  is complete.   ...   [2]",
            "10": "10 0620/33/o/n/20 \u00a9 ucles 2020  (e)  alcohols can also be manufactured from alkenes.   complete the word equation for the manufacture of ethanol by this method. +ethanol  [2]  [total: 12]",
            "11": "11 0620/33/o/n/20 \u00a9 ucles 2020 [turn over 6  the electrolysis of concentrated hydrochloric acid produces gases at each electrode.  (a)  describe the electrolysis of concentrated hydrochloric acid.   in your answer include:  \u25cf a labelled diagram of the apparatus used for the electrolysis and collection of gases  \u25cf the names of the products formed at the positive and the negative electrode.   positive electrode  ...   negative electrode  .  [5]  (b)  carbon dioxide is produced when hydrochloric acid reacts with sodium carbonate.   complete the chemical equation for this reaction.  na2co3  +  2hcl  \u2192  ..nac l  +  .  +  co2 [2]  (c)  carbon dioxide reacts with carbon to produce carbon monoxide. co2  +  c  \u2192  2co   explain how this equation shows that carbon dioxide has been reduced.   ..   [1]  [total: 8]",
            "12": "12 0620/33/o/n/20 \u00a9 ucles 2020 7  a student investigated the rate of reaction of excess calcium carbonate with dilute hydrochloric acid  in a conical flask by two different methods.  method 1:   measure the volume of carbon dioxide produced at 10 second intervals.  method 2:   measure the loss in mass of the reaction mixture by weighing at 10 second intervals.  (a) (i)  suggest one advantage of method 1 compared with method 2.   .   ...   [1]  (ii)  explain why there is a decrease in mass of the reaction mixture in method 2.   .   ...   [1]  (b)  the graph shows how the volume of carbon  dioxide changes as the reaction proceeds, using  method 1. 60 50 40 30 20 10 0 02 04 06 0 time  / svolum e of carbon dioxide / cm3 80 100 140 120",
            "13": "13 0620/33/o/n/20 \u00a9 ucles 2020 [turn over   the student used large pieces of calcium carbonate.   answer these questions using information from the graph.  (i)  describe how the rate of this reaction changes with time.   ...   [1]  (ii)  deduce the time taken to collect 36 cm3 of carbon dioxide.  time = .. s  [1]  (iii)  the experiment is repeated using smaller pieces of calcium carbonate.   draw a line on the grid to show how the volume of carbon dioxide changes with time  when smaller pieces of calcium carbonate are used.   all other conditions stay the same. [2]  (iv)  describe what effect the following changes have on the rate of this reaction.  \u25cf the temperature is increased.   all other conditions stay the same.   ..  \u25cf the concentration of the hydrochloric acid is decreased.   all other conditions stay the same.   ..  [2]  [total: 8]",
            "14": "14 0620/33/o/n/20 \u00a9 ucles 2020 8  this question is about metals and compounds of metals.  (a) (i)  sodium is a metal in group i of the periodic table.   identify two correct statements about sodium.   tick two boxes.   it is a relatively soft metal.   it has a high melting point.   it forms coloured chlorides.   it has a lower density than most metals.   it is a good insulator.  [2]  (ii)  some changes of state of sodium are shown. solid sodiummelting rliquid sodiumsodium gass condensing   give the names of the changes of state represented by r and s.  r  .  s  .  [2]",
            "15": "15 0620/33/o/n/20 \u00a9 ucles 2020 [turn over  (b)  the table compares the reactions of four metals with dilute and with concentrated  hydrochloric acid. metalobservation with dilute hydrochloric acidobservation with concentrated hydrochloric acid beryllium bubbles form rapidly bubbles form very rapidly copper no bubbles seen no bubbles seen iron bubbles form very slowly bubbles form  slowly nickel no bubbles seen bubbles form slowly   put the four metals in order of their reactivity.   put the least reactive metal first. least reactive most reactive  [2]  (c)  crystals of magnesium chloride, mgcl 2\u20226h2o, can be prepared by adding excess magnesium  powder to dilute hydrochloric acid.   describe how to prepare a sample of pure dry magnesium chloride crystals after the reaction  is complete.   in your answer describe how to:  \u25cf remove the excess magnesium from the reaction mixture  \u25cf crystallise the magnesium chloride  \u25cf dry the crystals.                        ..   [4]",
            "16": "16 0620/33/o/n/20 \u00a9 ucles 2020  (d)  when magnesium reacts with concentrated sulfuric  acid, sulfur dioxide is produced.   complete this description of the test for sulfur dioxide using words from the list.  blue chloride colourless  green manganate( vii) sulfate( vi)   the test for sulfur dioxide uses acidified aqueous potassium . .   the colour change is from purple to . .  [2]  (e)  green nickel( ii) sulfate crystals turn yellow when heated. niso4\u20227h2o                    niso4  +  7h2o  green yellow  nickel( ii) sulfate nickel( ii) sulfate  (i)  suggest how you would change yellow nickel( ii) sulfate to green nickel( ii) sulfate.   ...   [1]  (ii)  identify which word best describes green nickel( ii) sulfate with the formula niso4\u20227h2o.   draw a circle around the correct answer.  anhydrous          decomposed         hydrated          oxidised          reduced [1]  [total: 14]",
            "17": "17 0620/33/o/n/20 \u00a9 ucles 2020blank page",
            "18": "18 0620/33/o/n/20 \u00a9 ucles 2020blank page",
            "19": "19 0620/33/o/n/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/33/o/n/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w20_qp_41.pdf": {
            "1": "*1787085567* chemistry  0620/41 paper 4 theory (extended) october/november 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 11_0620_41/2rp \u00a9 ucles 2020 [turn overthis document has 20 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/41/o/n/20 \u00a9 ucles 2020 1 (a)  this question is about elements. aluminium carbon  iron hydrogen oxygen silicon  sodium sulfur   answer the following questions about these elements.   each element may be used once, more than once or not at all.  (i)  name the element that can be used as a fuel.   ...   [1]  (ii)  name the element that forms an oxide with a similar structure to diamond.   ...   [1]  (iii)  name the element that forms an amphoteric oxide.   ...   [1]  (iv)  name the element that has oxidation states of +2 and +3.   ...   [1]  (v)  name the element extracted from bauxite.   ...   [1]  (vi)  name the element that has atoms with the electronic structure 2,6.   ...   [1]",
            "3": "3 0620/41/o/n/20 \u00a9 ucles 2020 [turn over  (b)  iron rusts when it is in contact with oxygen and water.  (i)\t\texplain\thow \tsacrificial\tprotection\tprevents\trusting.   .   .   .   ...   [2]  (ii)  state one other\tmethod\tof\trust\tprevention.   ...   [1]  [total: 9]",
            "4": "4 0620/41/o/n/20 \u00a9 ucles 2020 2\t\tzinc\tis\textracted\tfrom\tan\tore\tcontaining\tzinc\tsulfide.  (a)  state the name of this zinc ore.   ..   [1]  (b)\t\tthis\tore\tis\tconverted\tto\tzinc\toxide,\tzno.   zinc oxide is then reacted with carbon.  (i)  write a chemical equation for the reaction of zinc oxide with carbon.   ...   [1]  (ii)  state what type of chemical change happens to the zinc in zinc oxide in this reaction.   explain your answer.  chemical change  .  explanation  .   .   .  [2]  (iii)  explain why aluminium is not extracted from aluminium oxide by heating with carbon.   .   ...   [1]  (iv)\t\tsuggest\tan \talternative\tmethod\tfor\tthe\textraction\tof\tzinc\tfrom\tzinc\toxide.   ...   [1]  (c)  brass is an alloy of zinc.   explain, in terms of particles, why brass is harder than pure zinc.               ..   [3]  [total: 9]",
            "5": "5 0620/41/o/n/20 \u00a9 ucles 2020 [turn over 3 (a)  aqueous ammonium sulfate, (nh4)2so4, is warmed with aqueous sodium hydroxide.   the pungent-smelling gas ammonia, nh3, is produced.   balance the equation for this reaction.  (nh4)2so4\t\t+\t\t..naoh\t\t \u2192  ..nh3  +  ..h2o\t\t+\t\tna2so4 [1]  (b)  a 2.8 g sample of impure ammonium sulfate is found to contain 0.7 g of impurities.   calculate the percentage of ammonium sulfate in this sample.  percentage of ammonium sulfate = .. %  [1]  (c)  describe a test for ammonia gas.  test  .  result  ..  [2]  (d)  ammonia gas is prepared at the front of a laboratory.   the pungent smell of ammonia spreads throughout the laboratory slowly.    (i)  name the process that occurs when ammonia gas spreads throughout the laboratory.   ...   [1]  (ii)  explain, using ideas about particles, why ammonia gas spreads throughout the laboratory.   .   .   .   ...   [2]  (iii)\t\texplain\twhy\tcarbon\tdioxide\tgas,\tco2, will spread throughout the laboratory at a slower  rate than ammonia gas, nh3.   .   ...   [1]",
            "6": "6 0620/41/o/n/20 \u00a9 ucles 2020  (e)  ammonia is produced in the haber process.   the equation for the reaction is shown. n2(g)  +  3h2(g)  \u2192  2nh3(g)  (i)  in the haber process, a temperature of 450 \u00b0c and a pressure of 200 atmospheres are  used\tin\tthe\tpresence\tof\tfinely\u2011divided\tiron.   a larger equilibrium yield of ammonia would be produced if a lower temperature and a  higher pressure are used.   explain why a lower temperature and a higher pressure are not used.  lower temperature  ...   .  higher pressure  ...   .  [2]  (ii)  state the role of iron in the haber process.   ...   [1]  (f) ammonia is a weak base.  (i)  explain the meaning of the term base.   .   ...   [1]  (ii)  suggest the ph of aqueous ammonia.   ...   [1]  [total: 13]",
            "7": "7 0620/41/o/n/20 \u00a9 ucles 2020 [turn over 4  air is a mixture of gases.  (a)\t\tstate\tthe\tpercentage\t of\tclean\tdry\tair\twhich\tis\toxygen.\t give\tyour\tanswer\tto\tthe\tnearest\twhole\t number.  .. %  [1]  (b)\t\toxygen\tand\tnitrogen\tare\tuseful\tgases\tthat\tcan\tbe\tobtained\tfrom\tair.  (i)  name the process used to separate oxygen and nitrogen from liquid air.   ...   [2]  (ii)  state the property of oxygen and nitrogen that allows these gases to be separated using  this process.   ...   [1]  (c)\t\tcarbon\tdioxide,\tco2,\tis\ta\tcovalent\tmolecule. \t \tcomplete\tthe\tdiagram\tto\tshow\tthe\telectron\tarrangement\tin\tone\tmolecule\tof\tco2.   show only the outer electrons. co o  [2]",
            "8": "8 0620/41/o/n/20 \u00a9 ucles 2020  (d)\t\tthe\tgraph\tshows\tthe\tconcentration\t of\tcarbon\tdioxide\tin\tthe\tatmosphere\t over\ta\t60\u2011year\tperiod,\t measured in parts per million (ppm). 420 400 380 360 340 320concentration of carbon dioxide / ppm year1960 1970 1980 1990 2000 2010 2020   the data shown in the graph is of global concern.   explain why.                  ..   [3]  (e)\t\tname\tthe\tprocess\t in\tthe\tcarbon\tcycle\tby\twhich\tplants\tremove\t carbon\tdioxide\tfrom\tthe\t atmosphere.   ..   [1]  [total: 10]",
            "9": "9 0620/41/o/n/20 \u00a9 ucles 2020 [turn over 5 (a)  dilute sulfuric acid is electrolysed using the apparatus shown in the diagram. power supply inert electrode s dilute sulfuric acid+\u2013  (i)  state what is meant by the term electrolysis.   .   .   ...   [2]  (ii)  explain why inert electrodes are used.   .   ...   [1]  (iii)  name the products formed at each electrode. \t negative\telectrode\t  .. \t positive\telectrode\t    [2]  (iv)\t\twrite\tan\tionic\thalf\u2011equation\tfor\tthe\treaction\tat\tthe\tnegative\telectrode.   ...   [2]",
            "10": "10 0620/41/o/n/20 \u00a9 ucles 2020  (b)\t\tsulfuric\t acid\tis\tmanufactured\t using\tthe\tcontact\t process.\t this\tmanufacture\t involves\t four\t stages.  (i)  stage 1\tinvolves\tthe\tcombustion\tof\tsulfur\tto\tform\tsulfur\tdioxide.   write the chemical equation for stage 1.   ...   [1]  (ii)  the equation for stage 2 is shown. 2so2(g)\t\t+\t\to2(g)  \t\t2so3(g)   the reaction can reach equilibrium.   explain what is meant by the term equilibrium.   .   .   .   ...   [2]  (iii)\t\tthe\tenergy \tlevel\tdiagram\tfor\tthe\tforward \treaction\tin\tstage 2 is shown. energy progress of reaction2so2(g)  +  o2(g) 2so3(g)   explain what the diagram shows about the energy changes in the forward reaction.   .   .   .   ...   [2]",
            "11": "11 0620/41/o/n/20 \u00a9 ucles 2020 [turn over  (c)  in stage 3\tsulfur\ttrioxide,\tso3,\tis\tconverted\tto\toleum,\th2s2o7.   in stage 4 oleum reacts to form sulfuric acid, h2so4.   state what oleum reacts with in stage 4.   ..   [1]  (d)  a sample of sulfuric acid, h2so4, has a concentration of 0.75 mol / dm3.   calculate the concentration of sulfuric acid in g / dm3.  .. g / dm3  [2]  [total: 15]",
            "12": "12 0620/41/o/n/20 \u00a9 ucles 2020 6 (a)  ethane, propane and butane are members of the same homologous series.  (i)  name this homologous series.   ...   [1]  (ii)  state two ways members of the same homologous series are similar.  1  ..  2  ..  [2]  (b)\t\tone\tmole\tof\tethane,\tc2h6, contains 6.02 \u00d7 1023 molecules.   calculate how many molecules are in 15 g of ethane.  number of ethane molecules = ..  [1]  (c)  propane reacts with chlorine.  (i) write the formula of the product which does not contain carbon.   ...   [1]  (ii)  draw the structure of an organic product formed. show all of the atoms and all of the  bonds.  [1]  (iii)  state the name of this type of reaction.   ...   [1]",
            "13": "13 0620/41/o/n/20 \u00a9 ucles 2020 [turn over  (d) (i)  aqueous bromine was added to a sample of ethene. \t \tgive\tthe\tcolour\tchange\tseen.  from . to     [2]  (ii)  explain, in terms of bonding, why there is no colour change when aqueous bromine is  added to ethane.   .   ...   [1]  (e)  there are two structural isomers with the formula c4h10.  (i)  draw the structures of both of these isomers, showing all of the atoms and all of the bonds.  [2]  (ii)  butane is formed when longer chain hydrocarbons are cracked.   complete the chemical equation to show the other product when butane is formed by  cracking.  c6h14  \u2192  c4h10  +   [1]",
            "14": "14 0620/41/o/n/20 \u00a9 ucles 2020  (f)  a compound contains 85.7% carbon and 14.3% hydrogen by mass.  (i)  calculate the empirical formula of this compound.   show your working.  ..  [2]  (ii)  the molecular mass of the compound is 112.   calculate the molecular formula of this compound.  ..  [1]  [total: 16]",
            "15": "15 0620/41/o/n/20 \u00a9 ucles 2020 [turn over 7 (a)  ethanol can be manufactured by two different methods.  method 1:   fermentation of a sugar, c6h12o6 c6h12o6  \u2192  2c2h5oh\t\t+\t\t2co2  method 2:   reaction of ethene with steam c2h4  +  h2o\t\t\u2192  c2h5oh  (i)\t\tgive\tone\tadvantage\tof\tusing\tfermentation\tcompared\twith\tmethod\t2.   .   ...   [1]  (ii)\t\tgive\tone\tdisadvantage\tof\tusing\tfermentation\tcompared\twith\tmethod\t2.   .   ...   [1]  (b)\t\tethanol\treacts\twith\tacidified\t potassium\t manganate( vii) to form water and a product that turns  litmus red.  (i)  state the name of the product that turns the litmus red.   ...   [1]  (ii)\t\tstate\tthe\ttype\tof\treaction\t that\tethanol\t undergoes\t when\tit\treacts\twith\tacidified\t potassium manganate( vii).   ...   [1]  (c)  ethanol reacts with methanoic acid to form an ester.  (i)  name the ester formed in this reaction.   ...   [1]  (ii)  draw the structure of the ester formed.   show all of the atoms and all of the bonds.  [1]",
            "16": "16 0620/41/o/n/20 \u00a9 ucles 2020  (d)  the table shows the melting points of ethanol and sodium chloride. substance melting point / \u00b0c ethanol \u2013114 sodium chloride 801 \t \tthe\tdifference\t in\tmelting\tpoints\tis\tdue\tto\tdifferences\t in\tattractive\t forces\tbetween\t particles\t in\t these substances. \t \tname\tthe\ttype\tof\tattractive\t force\tin\teach\tsubstance,\t which\tis\tresponsible\t for\tthe\tdifference\t in\t melting points.  ethanol  ...  sodium chloride  .  [2]  [total: 8]",
            "17": "17 0620/41/o/n/20 \u00a9 ucles 2020blank page",
            "18": "18 0620/41/o/n/20 \u00a9 ucles 2020blank page",
            "19": "19 0620/41/o/n/20 \u00a9 ucles 2020permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "20": "20 0620/41/o/n/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w20_qp_42.pdf": {
            "1": "*7179838283* chemistry  0620/42 paper 4 theory (extended) october/november 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 11_0620_42/4rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/42/o/n/20 \u00a9 ucles 2020 1  the electronic structures of some atoms and ions are shown. a b c d fg+2+ 3\u2013 \u2013 \u2013h e  (a)  write the letters, a, b, c, d, e, f, g or h, of the electronic structures which show:  (i)  atoms of two different noble gases ... and  ..  [2]  (ii)  an ion of a group i element  ..   [1]  (iii)  an ion of a group v element  .   [1]  (iv)  a pair of ions that could form a compound with the formula xy2.  and  .   [1]  (b)  state which electronic structure, a, b, c, d, e, f, g or h, is incorrect.   explain why.  incorrect electronic structure  .  explanation       [2]  (c)  state how many protons are found in the nucleus of ion c.     [1]  (d)  use the periodic table to deduce:  (i)  the chemical symbol for ion g  ..   [1]  (ii)  the element which forms an ion with a 3+ charge and the same electronic structure as h.   ...   [1]  [total: 10]",
            "3": "3 0620/42/o/n/20 \u00a9 ucles 2020 [turn over 2  soluble salts can be made by adding a metal carbonate to a dilute acid.  (a)  give the formula of the dilute acid which reacts with a metal carbonate to form a nitrate salt.   ..   [1]  (b)  a student wanted to make hydrated iron( ii) sulfate crystals, feso4\u2022xh2o, by adding excess  iron(ii) carbonate to dilute sulfuric acid. the student followed the procedure shown.  step 1  add dilute sulfuric acid to a beaker.  step 2  add small amounts of iron( ii) carbonate to the dilute sulfuric acid in the beaker until  the iron( ii) carbonate is in excess.  step 3  filter the mixture formed in step 2.  step 4\t \theat\tthe\tfiltrate\tuntil\tit\tis\ta\tsaturated\tsolution.\t allow\tto\tcool.  step 5\t \tonce\tcold,\tpour\taway\tthe\tremaining\tsolution.\tdry\tthe\tcrystals\tbetween\tfilter\tpapers.  (i)  why must the iron( ii) carbonate be added in excess in step 2?   ...   [1]  (ii)  state two observations in step 2 that would show that iron( ii) carbonate was in excess.  1  ..  2  ..  [2]  (iii)  describe what should be done during step 3 to ensure there is a maximum yield of crystals.   ...   [1]  (iv)  a saturated solution is formed in step 4.   describe what a saturated solution is.   .   ...   [2]  (v)  name a different compound that could be used instead of iron( ii) carbonate to produce  hydrated iron( ii) sulfate crystals from dilute sulfuric acid.   ...   [1]",
            "4": "4 0620/42/o/n/20 \u00a9 ucles 2020  (c)  on analysing the crystals, the student found that one mole of the hydrated iron( ii) sulfate  crystals, feso4\u2022xh2o, had a mass of 278 g.   determine the value of x using the following steps:  \u25cf calculate the mass of one mole of feso4  mass = .. g  \u25cf calculate the mass of h2o present in one mole of feso4\u2022xh2o  mass of h2o = .. g  \u25cf determine the value of x.  x = ..  [3]  (d)  insoluble salts can be made by mixing solutions of two soluble salts.   a student followed the procedure shown to make silver bromide, an insoluble salt.  step 1  add aqueous silver nitrate to a beaker. then add aqueous potassium bromide and  stir.  step 2  filter the mixture formed in step 1.  step 3  dry the residue.  (i)  state the term used to describe this method of making salts.   ...   [1]  (ii)  give the observation the student would make during step 1.   ...   [1]  (iii)  write the ionic equation for the reaction between aqueous silver nitrate and aqueous  potassium bromide.   include state symbols.   ...   [3]",
            "5": "5 0620/42/o/n/20 \u00a9 ucles 2020 [turn over  (e)  sodium chloride is an ionic salt. it can be made by reacting sodium with chlorine gas.   the equation for this reaction is shown. 2na(s)  +  cl 2(g)  \u2192  2nacl (s)   calculate the volume of chlorine gas, in cm3, that reacts to form 2.34 g of nacl .   the reaction takes place at room temperature and pressure.  volume of chlorine gas = .. cm3  [3]  (f)  sodium chloride does not conduct electricity when solid, but does conduct electricity when  molten.  (i)  explain why, in terms of structure and bonding.   .   .   .   ...   [3]  (ii)  name the product formed at the positive electrode when electricity is passed through  molten sodium chloride.   ...   [1]  (iii)  state the type of change that occurs at the positive electrode in (ii).   explain your answer in terms of electron transfer.  type of change    explanation  .  [2]  (iv)  describe what else can be done to sodium chloride to allow it to conduct electricity.   ...   [1]  [total: 26]",
            "6": "6 0620/42/o/n/20 \u00a9 ucles 2020 3  group i metals are very reactive. transition elements are also metals but are less reactive than  group i metals.  (a)  state two physical properties of group i metals which are similar to those of transition metals.  1  .  2  .  [2]  (b)  describe two ways in which the physical properties of group i metals are different from those  of transition metals.  1  .     2  .     [2]  (c)\t\twhen\tgroup\ti\tmetals\tare\tadded\tto\twater\tthey\tfizz\tand\tan\talkaline\tsolution\tforms.  (i)  name the gas given off.   ...   [1]  (ii)  identify the ion present in the solution which makes the solution alkaline.   ...   [1]  (iii)  write the chemical equation for the reaction between sodium and water.   ...   [2]  (d)  when the transition element iron is added to water the iron rusts. \t \twhen\tan\tiron\tobject\tis\tcoated\twith\ta\tlayer\tof\tzinc,\trusting\tis\tprevented.  (i)\t\tname\tthis\tprocess\tof\tcoating\tiron\tobjects\twith\ta\tlayer\tof\tzinc.   ...   [1]  (ii)\t\texplain\thow \tcompletely\tcoating\tan\tiron\t object\twith\ta\tlayer\tof\tzinc\tprevents\trusting.   ...   [1]  (iii)\t\trusting\tof\tiron\tships\tcan\tbe\tprevented\tby\tattaching\tzinc\tblocks\tto\tthe\thull\tof\tthe\tship.   explain how this prevents rusting.   .   ...   [2]  [total: 12]",
            "7": "7 0620/42/o/n/20 \u00a9 ucles 2020 [turn over 4  alkenes and alkanes are homologous series of compounds containing carbon and hydrogen atoms.  (a)  state the name of the type of compound made from carbon and hydrogen atoms only.   ..   [1]  (b)  alkenes take part in addition reactions.  (i)  describe what is meant by the term addition reaction .   ...   [1]  (ii)  draw the structure of the product made in the addition reaction between propene and  bromine. show all of the atoms and all of the bonds.  [2]  (iii)  describe the colour change seen when propene is added to aqueous bromine.  from   to     [2]  (iv)  draw the structures of molecules of two different alkenes which both undergo an addition  reaction with steam to form butan-2-ol. show all of the atoms and all of the bonds.  [2]  (c)  propane undergoes a substitution reaction with chlorine.   write the chemical equation for the reaction between one molecule of propane and one  molecule of chlorine.   ..   [2]  [total: 10]",
            "8": "8 0620/42/o/n/20 \u00a9 ucles 2020 5  this question is about alcohols, carboxylic acids and esters.  (a)  ethanol will react with hot aqueous potassium manganate( vii) to form ethanoic acid.  (i)  state the other condition needed for this reaction to take place.   ...   [1]  (ii)  state the type of chemical change that happens to the ethanol during this reaction.   ...   [1]  (iii)  the structure of ethanoic acid is shown. o ohch hc h   complete the dot-and-cross diagram to show the electron arrangement in a molecule of  ethanoic acid. ccoh hhh o  [3]",
            "9": "9 0620/42/o/n/20 \u00a9 ucles 2020 [turn over  (b)  ethanoic acid is a weak acid and hydrochloric acid is a strong acid.   complete the table to show the similarities and differences in the properties of samples of  these two acids of equal concentration. dilute ethanoic acid dilute hydrochloric acid extent of dissociation colour after adding  universal indicator solution observation when  magnesium ribbon is added  [6]  (c)  ethanoic acid will react with an alcohol to form the ester shown. hch hc cco ochh h h hh h  (i)  name the other product formed when ethanoic acid reacts with an alcohol to make this  ester.   ...   [1]  (ii)  give one condition needed when ethanoic acid reacts with the alcohol to make this ester.   ...   [1]  (iii)  draw the structure of the alcohol which was added to ethanoic acid to make this ester.  show all of the atoms and all of the bonds.  [2]",
            "10": "10 0620/42/o/n/20 \u00a9 ucles 2020  (d)  polyesters can be manufactured from carboxylic acids and alcohols.   hexanedioic acid has the structure: hooc\u2013ch2\u2013ch2\u2013ch2\u2013ch2\u2013cooh. \t \tthis\tstructure\tcan\tbe\tsimplified\tas\tshown. co co o ho h   ethanediol has the structure: ho\u2013ch2\u2013ch2\u2013oh. \t \tthis\tstructure\tcan\tbe\tsimplified\tas\tshown. o ho h   the functional groups are found at the end of each molecule.  (i)  state what is meant by the term functional group .   ...   [1]  (ii)  determine the empirical formula of hexanedioic acid.   ...   [1]  (iii)  calculate the percentage by mass of oxygen present in ethanediol.   give your answer to the nearest whole number.  .. %  [2]  (iv)  complete the diagram to show a section of polyester manufactured from hexanedioic acid  and ethanediol. include all of the atoms and all of the bonds in the linkages.  [2]  (v)  state the name of a polyester.   ...   [1]  [total: 22]",
            "11": "11 0620/42/o/n/20 \u00a9 ucles 2020permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "12": "12 0620/42/o/n/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w20_qp_43.pdf": {
            "1": "*0774897954* chemistry  0620/43 paper 4 theory (extended) october/november 2020  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib20 11_0620_43/4rp r \u00a9 ucles 2020 [turn overthis document has 16 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/43/o/n/20 \u00a9 ucles 2020 1  the names of nine substances are shown. aluminium oxide ammonia carbon monoxide anhydrous cobalt( ii) chloride hydrated copper( ii) sulfate iron( iii) oxide nitrogen dioxide silver steel   answer the following questions using these substances. each substance may be used once, more  than once or not at all.   name the substance that is:  (a)  the main constituent of hematite  ..   [1]  (b)  a gas produced in car engines which causes acid rain  ...   [1]  (c)  an alkaline gas  .   [1]  (d)  an element  ...   [1]  (e)  a gas formed by the incomplete combustion of fossil fuels  .   [1]  (f)  used to test for the presence of water.     [1]  [total: 6]",
            "3": "3 0620/43/o/n/20 \u00a9 ucles 2020 [turn over 2  the table gives information about five particles, a, b, c, d and e. particlenumber of electronsnumber of neutronsnumber of protons a 10 13 11 b 18 20 18 c 18 18 18 d 10 12 8 e 10 10 10  (a)  state the atomic number of a.   ..   [1]  (b)  state the nucleon number of b.   ..   [1]  (c)  write the electronic structure of c.   ..   [1]  (d)  give the letters of all the particles which are:  (i)  atoms     [1]  (ii)  positive ions  ..   [1]  (iii)  negative ions     [1]  (iv)  isotopes of each other.  .   [1]  [total: 7]",
            "4": "4 0620/43/o/n/20 \u00a9 ucles 2020 3  this question is about nitrogen and some of its compounds.  (a)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  nitrogen, n2.   show the outer shell electrons only. n n  [2]  (b)  nitrogen can be converted into ammonia by the haber process.  (i)  describe how nitrogen is obtained for the haber process.   .   ...   [2]  (ii)  give the essential reaction conditions and write a chemical equation for the reaction  occurring in the haber process.  chemical equation:  ..   .  reaction conditions:  .   .   .   .   .  [5]",
            "5": "5 0620/43/o/n/20 \u00a9 ucles 2020 [turn over  (c)  some of the ammonia made by the haber process is converted into nitric acid.   the first stage of this process is the oxidation of ammonia to make nitrogen monoxide. 4nh3(g)  +  5o2(g)    4no(g)  +  6h2o(g)   the process is carried out at 900 \u00b0c and a pressure of 5 atmospheres using an alloy of platinum  and rhodium as a catalyst.   the forward reaction is exothermic.  (i)  state the meaning of the term catalyst.   .   ...   [2]  (ii)  state the meaning of the term oxidation .   ...   [1]  (iii)  complete the table using the words increase , decrease  or no change . effect on the rate of the forward reactioneffect on the equilibrium yield of no(g) increasing the temperature increasing the pressure  [4]  (d)  nitrogen monoxide, no, is converted into nitrogen dioxide, no2. 2no(g)  +  o2(g)  \u2192  2no2(g)   the nitrogen dioxide reacts with oxygen and water to produce nitric acid as the only product.   write a chemical equation for this reaction.   ..   [2]",
            "6": "6 0620/43/o/n/20 \u00a9 ucles 2020  (e)  ammonium nitrate, nh4no3, is a fertiliser.   calculate the percentage by mass of nitrogen in ammonium nitrate.  .. %  [2]  [total: 20]",
            "7": "7 0620/43/o/n/20 \u00a9 ucles 2020 [turn over 4  zinc is manufactured from zinc blende. zinc blende is an ore which consists mainly of zinc sulfide,  zns.  (a)  zinc blende is roasted in air. one of the products is zinc oxide.   name the other product formed in this reaction.   ..   [1]  (b)  zinc oxide is then converted into zinc.   zinc oxide and coke, a source of carbon, are heated in a furnace. hot air is blown into the  furnace.  (i)  give two reasons why coke is needed.  1  ..  2  ..  [2]  (ii)  write a chemical equation for the formation of zinc in the furnace.   ...   [1]  (iii)  zinc has a melting point of 420 \u00b0c and a boiling point of 907 \u00b0c. the temperature inside the  furnace is 1200 \u00b0c.   explain how this information shows that the zinc produced inside the furnace is a gas.   ...   [1]  (iv)  the gaseous zinc is converted to molten zinc.   name this change of state.   ...   [1]",
            "8": "8 0620/43/o/n/20 \u00a9 ucles 2020  (c)  zinc reacts with dilute sulfuric acid to produce aqueous zinc sulfate. zn(s)  +  h2so4(aq)  \u2192  znso4(aq)  +  h2(g)   hydrated zinc sulfate crystals are made from aqueous zinc sulfate.  step 1  solid zinc is added to dilute sulfuric acid until zinc is in excess.  step 2  excess zinc is separated from aqueous zinc sulfate by filtration.  step 3  aqueous zinc sulfate is heated until the solution is saturated.  step 4  the saturated solution is allowed to cool and crystallise.  step 5  the crystals are removed and dried.  (i)  name the residue in step 2.   ...   [1]  (ii)  in step 3, a saturated solution is produced.   describe what a saturated solution is.   .   .   ...   [2]  (iii)  name two compounds each of which react with dilute sulfuric acid to produce aqueous  zinc sulfate.  1  ..  2  ..  [2]",
            "9": "9 0620/43/o/n/20 \u00a9 ucles 2020 [turn over  (d)  when hydrated magnesium sulfate crystals, mgso4\u2022xh2o, are heated they give off water. mgso4\u2022xh2o(s)  \u2192  mgso4(s)  +  xh2o(g)   a student carries out an experiment to determine the value of x in mgso4\u2022xh2o.  step 1  hydrated magnesium sulfate crystals were weighed.  step 2  hydrated magnesium sulfate crystals were heated.  step 3  the remaining solid was weighed.  (i)  describe how the student can ensure that all the water is given off.   .   .   ...   [2]  (ii)  in an experiment, all the water was removed from 1.23 g of mgso4\u2022xh2o. the mass of  mgso4 remaining was 0.60 g.  mr: mgso4 = 120; mr: h2o = 18   determine the value of x using the following steps.  \u25cf calculate the number of moles of mgso4 remaining.  moles of mgso4 = ..  \u25cf calculate the mass of h2o given off.  mass of h2o = .. g  \u25cf calculate the moles of h2o given off.  moles of h2o = ..  \u25cf determine the value of x.  x = ..  [4]  [total: 17]",
            "10": "10 0620/43/o/n/20 \u00a9 ucles 2020 5  group i elements, group vii elements and transition elements are found in different parts of the  periodic table.  (a)  describe the trend in the reactivity of group i elements.      ..   [1]  (b)  when potassium is added to water a chemical reaction occurs.  (i)  state two observations that can be made when potassium is added to water.   .   ...   [2]  (ii)  write a chemical equation for the reaction of potassium with water.   ...   [2]  (c)  excess aqueous potassium iodide is added to chlorine.  (i)  write a chemical equation for the reaction that occurs when aqueous potassium iodide is  added to chlorine.   ...   [2]  (ii)  state the final colour of the reaction mixture.   ...   [1]  (d)  sodium is extracted from sodium chloride by electrolysis.  (i)  state the meaning of the term electrolysis.   .   ...   [2]  (ii)  state what must be done to sodium chloride before it can be electrolysed to produce  sodium.   ...   [1]  (iii)  write an ionic half-equation for the change that occurs at the cathode during this electrolysis.   ...   [1]",
            "11": "11 0620/43/o/n/20 \u00a9 ucles 2020 [turn over  (e)  chromium is a transition element.  \u25cf chromium has a high melting point.  \u25cf chromium is a good conductor of electricity.  \u25cf many chromium compounds are soluble in water.  \u25cf hydrated chromium( iii) sulfate is green.  \u25cf chromium forms the chlorides crc l 2 and crcl 3.  \u25cf oxides of chromium act as catalysts in the manufacture of poly(ethene).  (i)  use this information to give two properties of chromium which are different from properties  of group i elements such as sodium.  1  ..  2  ..  [2]  (ii)  use this information to give two properties of chromium which are similar to properties of  group i elements such as sodium.  1  ..  2  ..  [2]  [total: 16]",
            "12": "12 0620/43/o/n/20 \u00a9 ucles 2020 6 (a)  a carboxylic acid and an ester are structural isomers.  (i)  state the meaning of the term structural isomers.   .   .   ...   [2]  (ii)  draw the structures of the carboxylic acid and the ester which both contain two carbon  atoms.   show all of the atoms and all of the bonds.   name the carboxylic acid and the ester. carboxylic acid name ester name   [4]",
            "13": "13 0620/43/o/n/20 \u00a9 ucles 2020 [turn over  (b)  part of a polyester chain is shown. this polyester is made from one monomer. co o o co o co o co  (i)  on the diagram  draw a ring around one unit of the polymer that is repeated. [1]  (ii)  name the type of polymerisation that produces polyesters.   ...   [1]  (iii)  complete the diagram to show the structure of the monomer used to produce this polyester.   show all of the atoms and all of the bonds in the functional groups.  [2]  (c)  a polyamide is made from the two monomers shown. h2n nh2 hooc cooh   complete the diagram to show a section of the polyamide made from the two monomers.   show all of the atoms and all of the bonds in the linkages.  [2]  (d)  naturally occurring polyamides are constituents of food.  (i)  state the name given to naturally occurring polyamides.   ...   [1]  (ii)  name the monomers which form naturally occurring polyamides.   ...   [1]  [total: 14]",
            "14": "14 0620/43/o/n/20 \u00a9 ucles 2020blank page",
            "15": "15 0620/43/o/n/20 \u00a9 ucles 2020permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/43/o/n/20 \u00a9 ucles 2020 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w20_qp_51.pdf": {
            "1": "*2079716460* chemistry  0620/51 paper 5 practical test october/november 2020  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib20 11_0620_51/fp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/51/o/n/20 \u00a9 ucles 2020 1  you are going to investigate the reaction between dilute ethanoic acid and two different solutions of  sodium hydroxide labelled solution a and solution b.   read all of the instructions carefully before starting the experiments.  instructions   you are going to do two experiments.  (a) experiment 1  \u25cf rinse the burette with solution a.  \u25cf fill the burette with solution  a. run some of solution a out of the burette so that the level  of solution a is on the burette scale.  \u25cf use the measuring cylinder to pour 25 cm3 of dilute ethanoic acid into the conical flask.  \u25cf add five drops of thymolphthalein indicator to the conical flask.  \u25cf record the initial burette reading in the table.  \u25cf slowly add solution a from the burette to the conical flask, while swirling the flask, until the  solution just changes colour.  \u25cf record the final burette reading in the table and complete the table. experiment 1 final burette reading / cm3 initial burette reading / cm3 volume of solution a added / cm3  experiment 2  \u25cf empty the conical flask and rinse it with distilled water.  \u25cf empty the burette and rinse it with distilled water.  \u25cf rinse the burette with solution b.  \u25cf fill the burette with solution  b. run some of solution b out of the burette so that the level  of solution b is on the burette scale.  \u25cf use the measuring cylinder to pour 25 cm3 of dilute ethanoic acid into the conical flask.  \u25cf add five drops of thymolphthalein indicator to the conical flask.  \u25cf record the initial burette reading in the table.  \u25cf slowly add solution b from the burette to the conical flask, while swirling the flask, until the  solution just changes colour.  \u25cf record the final burette reading in the table and complete the table. experiment 2 final burette reading / cm3 initial burette reading / cm3 volume of solution b added / cm3  [4]",
            "3": "3 0620/51/o/n/20 \u00a9 ucles 2020 [turn over  (b)  state the colour change observed in the conical flask in experiment 2.  from . to  ...   [1]  (c)  explain why universal indicator is not a suitable indicator to use in this titration.      ..   [1]  (d) (i)  state which solution of sodium hydroxide, solution a or solution b, is the more concentrated.   explain your answer.   .   ...   [1]  (ii)  state how many times more concentrated this solution of sodium hydroxide is compared  to the other solution of sodium hydroxide.   .   ...   [1]  (e)  determine the volume of solution b that would be required if experiment 2 was repeated with  10 cm3 of dilute ethanoic acid.      ..   [2]  (f)  describe how the reliability of the results could be checked.      ..   [1]  (g)  a 25 cm3 pipette can be used to measure the volume of a solution.  (i)  describe an advantage of using a 25 cm3 pipette to measure the volume of the  dilute ethanoic acid.   .   ...   [1]  (ii)  explain why a 25 cm3 pipette could not be used to measure the volume of solution a.   .   ...   [1]",
            "4": "4 0620/51/o/n/20 \u00a9 ucles 2020  (h) (i)  explain why the burette was rinsed with distilled water in experiment 2.   .   ...   [1]  (ii)  explain why the burette was then rinsed with solution b.   .   ...   [1]  (iii)  state the effect that not rinsing the burette with solution b would have on the final burette  reading.   explain your answer.  effect  ...  explanation  .   .  [2]  [total: 17]",
            "5": "5 0620/51/o/n/20 \u00a9 ucles 2020 [turn over 2  you are provided with two solids, solid c and solid d.   do the following tests on solid c and solid d, recording all of your observations at each stage.   tests on solid c  (a)  describe the appearance of solid c.   ..   [1]  (b)  place about half of solid c in a hard\u2011glass test\u2011tube. heat the solid gently and then strongly.   record your observations.            ..   [3]  (c)  place the remaining half of solid c in a boiling tube. add about 10 cm3 of distilled water to the   boiling tube. stopper the boiling tube and shake it to dissolve solid c to form solution c.   divide solution c into two approximately equal portions in two test\u2011tubes.  (i)  add a few drops of universal indicator solution to the first portion of solution c.   record your observations.   .   ...   [1]  (ii)  add a spatula measure of solid sodium hydrogencarbonate to the second portion of  solution c.    test any gas formed.   record your observations.   .   .   .   ...   [3]  (d)  what conclusions can you make about solid c?      ..   [2]",
            "6": "6 0620/51/o/n/20 \u00a9 ucles 2020  tests on solid d   add solid  d to about 10 cm3 of distilled water in a boiling tube. stopper the boiling tube and shake  it to dissolve solid d to form solution d.   divide solution d into four approximately equal portions in four test\u2011tubes.  (e) (i)  add a few drops of aqueous sodium hydroxide to the first portion of solution d.   record your observations.   ...   [1]  (ii)  now add an excess of aqueous sodium hydroxide to the mixture.   record your observations.   ...   [1]  (f)  add excess aqueous ammonia to the second portion of solution d.   record your observations.   ..   [1]  (g)  add about 1 cm depth of dilute nitric acid and a few drops of aqueous silver nitrate to the third  portion of solution d.   record your observations.   ..   [1]  (h)  add about 1 cm depth of dilute nitric acid and a few drops of aqueous barium nitrate to the  fourth portion of solution d.   record your observations.   ..   [1]  (i)  identify solid d.   ..   [2]  [total: 17]",
            "7": "7 0620/51/o/n/20 \u00a9 ucles 2020 [turn over 3  a toothpaste contains:  \u25cf sodium fluoride  \u25cf calcium carbonate  \u25cf silica  \u25cf mint flavouring.   sodium fluoride and the mint flavouring are soluble in water.   calcium carbonate and silica are insoluble in water.   calcium carbonate reacts with dilute hydrochloric  acid to form the soluble salt calcium chloride.   plan an investigation to find the percentage by mass of silica in the toothpaste.   in your answer you should include how you will calculate the percentage by mass of silica in the  toothpaste.   you have access to normal laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/51/o/n/20 \u00a9 ucles 2020blank page",
            "9": "9 0620/51/o/n/20 \u00a9 ucles 2020blank page",
            "10": "10 0620/51/o/n/20 \u00a9 ucles 2020blank page 2  you are provided with two metal salt solutions, e and f.   carry out the following tests on e and f, recording all of your observations at each stage.",
            "11": "11 0620/51/o/n/20 \u00a9 ucles 2020notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/51/o/n/20 \u00a9 ucles 2020tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w20_qp_52.pdf": {
            "1": "*0436997365* chemistry  0620/52 paper 5 practical test october/november 2020  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib20 11_0620_52/3rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/52/o/n/20 \u00a9 ucles 2020 1\t\tyou\tare\tgoing\tto\tinvestigate\t the\trate\tof\tthe\treaction\tbetween\t sodium\tmetabisulfite\t and\t potassium iodate.   read all of the instructions carefully before starting the experiments.   instructions \t\tyou\tare\tgoing\tto\tdo\tfive\texperiments.\tin\teach\texperiment\tthe\ttotal\tvolume\tof\tliquid\tis\t45\t cm3.   experiment 1  \u25cf use a 10 cm3\tmeasuring\t cylinder\tto\tpour\t5\tcm3\tof\taqueous\tsodium\tmetabisulfite\t into\tthe\tbeaker.  \u25cf use another 10 cm3\tmeasuring\tcylinder\tto\tpour\t5\t cm3\tof\tstarch\tsolution\tinto\tthe\tbeaker.  \u25cf\tuse\ta\t25\tcm3\tmeasuring\tcylinder\tto\tpour\t15\t cm3\tof\tdistilled\twater\tinto\tthe\tbeaker.  \u25cf\tuse\tanother\t25\tcm3 measuring cylinder to pour 20 cm3\tof\taqueous\tpotassium\t iodate\tinto\tthe\t beaker.\tat\tthe\tsame\ttime\tstart\tthe\tstop\u2011clock.  \u25cf\tstir\tthe\tmixture\tin\tthe\tbeaker\tand\tcontinue\tto\tstir\tuntil\ta\tsudden\tcolour\tchange\tis\tseen.  \u25cf\tstop\tthe\tstop\u2011clock\tand\trecord\tthe\ttime\tin\tseconds\tto\tthe\tnearest\twhole\tnumber\tin\tthe\ttable.  \u25cf\trinse\tthe\tbeaker\twith\twater.   experiment 2  \u25cf\trepeat\texperiment\t1\tusing\t17\t cm3 of distilled water and 18 cm3\tof\taqueous\tpotassium\tiodate.   experiment 3  \u25cf\trepeat\texperiment\t1\tusing\t21\t cm3\tof\tdistilled\twater\tand\t14\t cm3\tof\taqueous\tpotassium\tiodate.   experiment 4  \u25cf\trepeat\texperiment\t1\tusing\t23\t cm3 of distilled water and 12 cm3\tof\taqueous\tpotassium\tiodate.   experiment 5  \u25cf\trepeat\texperiment\t1\tusing\t25\t cm3 of distilled water and 10 cm3\tof\taqueous\tpotassium\tiodate.  (a)  complete the table. experiment 1 2 345 volume\tof\taqueous\tsodium\tmetabisulfite\t /\tcm3 volume\tof\tdistilled\twater\t /\tcm3 volume\tof\taqueous\tpotassium\tiodate\t /\tcm320 1814 12 10 time\ttaken\tto\tchange\tcolour\t /\ts \t [4]  (b)  state the sudden colour change seen.  start colour  .  end colour  .. \t [1]",
            "3": "3 0620/52/o/n/20 \u00a9 ucles 2020 [turn over  (c)\t\tadd\ta\tsuitable\tscale\tfor\tthe\t y\u2011axis\tand\tplot\tyour\tresults\tfrom\texperiments\t1\tto\t5\ton\tthe\tgrid. \t\tdraw\ta\tsmooth\tcurve\tof\tbest\tfit.\t 10 12 14 16 18 volume of aqueous potassium iodate  / cm3time to change colour  / s 20 22 \t [4]  (d) (i)  from your graph, predict the time to change colour if 16 cm3\tof\taqueous\tpotassium\t iodate\t was used.   show clearly on the grid \thow\tyou\tworked\tout\tyour\tanswer. \t time\tto\tchange\tcolour\t=\t..\ts\t\t[2]  (ii)\t\tcalculate\t the\tvolume\tof\tdistilled\twater\trequired\tif\t16\tcm3\tof\taqueous\tpotassium\t iodate\twas\t used.  volume of distilled water = .. cm3\t\t[1]  (e)\t\tsketch\t on the grid\t the\tgraph\tyou\twould\texpect\tif\texperiments\t 1\tto\t5\twere\trepeated\tat\ta\thigher\t temperature.\t [1]",
            "4": "4 0620/52/o/n/20 \u00a9 ucles 2020  (f)\t\tthe\tconcentration \tof\tpotassium\t iodate\tin\tthe\treaction\tmixture\tin\teach\texperiment\t can\tbe\t calculated\tusing\tthe\tequation\tshown. concentration =0.05\t\u00d7\tvolume\tof\taqueous\tpotassium\tiodate 45  (i)\t\tcalculate\tthe\tconcentration\tof\tpotassium \tiodate\tin\tthe\treaction\tmixture\tin\texperiment\t2. \t concentration\t=\t..\tmol\t /\tdm3\t\t[1]  (ii)\t\tstate\twhich\texperiment,\t1,\t2,\t3,\t4\tor\t5,\thad\tthe\tfastest\trate\tof\treaction.   ... \t\t[1]  (g)\t\tsuggest\twhy\tthe\tvolume\tof\tdistilled\twater\tadded\tto\teach\texperiment\t was\tincreased\t as\tthe\t volume\tof\taqueous\tpotassium\tiodate\twas\tdecreased.      .. \t\t[1]  (h)  give one\tchange\tyou\tcould\tmake\tto\tthe\tapparatus\tused\twhich\twould\timprove\tthe\tresults. \t\texplain\tyour\tanswer.  change to apparatus  ..    \t explanation\t      \t [2]  (i)\t\tdescribe\thow\tthe\treliability\tof\tthe\tresults\tof\tthis\tinvestigation\tcould\tbe\tchecked.      .. \t\t[1] \t [total:\t19]",
            "5": "5 0620/52/o/n/20 \u00a9 ucles 2020 [turn over 2  you are provided with two solids, solid q and solid r.   do the following tests on solid q and solid r, recording all of your observations at each stage.   tests on solid q  (a)\t\tusing\ta\tspatula,\tplace\tapproximately\tthree\tquarters \tof\tsolid\tq in a boiling tube. \t\tadd\tabout\t10\t cm3 of dilute sulfuric acid to the boiling tube. test any gas produced.   record your observations.   keep the contents of the boiling tube for (c).         .. \t\t[3]  (b)\t\tidentify\tthe\tgas\tgiven\toff\tin\t(a).   .. \t\t[1]  (c)\t\tfilter\tthe\treaction\tmixture\tfrom\t(a). \t\tthe\tfiltrate\tis\tsolution\t s. pour 1 cm depth of solution s into a boiling tube.  (i)  to solution  s\tin\tthe\tboiling\ttube\tadd\taqueous\tsodium\thydroxide\t dropwise\t and\tthen\tin\t excess.   record your observations.   .   .   ... \t\t[2]  (ii)\t\texplain\twhy\tit\tis\tnot\tpossible\tto\tidentify\tthe\tcation\tcontained\t in\tsolution\t s from your  observations in (c)(i).   .   ... \t\t[1]  (iii)  suggest an additional test that can be done on solution s that would allow you to identify  the cation contained in solution s.   do not carry out this test.   .   ... \t\t[1]",
            "6": "6 0620/52/o/n/20 \u00a9 ucles 2020  (d)  place the remaining solid q\tin\ta\thard\u2011glass\t test\u2011tube.\t heat\tthe\tsolid\tstrongly\tuntil\tno\tfurther\t change is seen. stop heating and leave the solid to cool.   record your observations.         .. \t\t[2]  tests on solid r  (e)\t\tcarry\tout\ta\tflame\ttest\ton\tsolid\tr.   record your observations.   .. \t\t[1]  (f)  place solid r\tin\ta\tboiling\ttube.\tadd\tabout\t10\tcm3 of distilled water to the boiling tube. place a  stopper\tin\tthe\tboiling\ttube\tand\tshake\tthe\ttube\tto\tdissolve\tsolid\t r and form solution r.   divide solution r\tinto\ttwo\tapproximately\tequal\tportions\tin\ttwo\ttest\u2011tubes.  (i)\t\tadd\tthe\tfirst\tportion\tof\tsolution\tr\tto\tthe\taqueous\tbromine\tprovided\tin\ta\ttest\u2011tube.   record your observations.   ... \t\t[1]  (ii)  to the second portion of solution r add about 1 cm depth of dilute nitric acid followed by a  few\tdrops\tof\taqueous\tsilver\tnitrate.   record your observations.   .   ... \t\t[1]  (g)\t\tidentify\tsolid\tr.      .. \t\t[2] \t [total:\t15]",
            "7": "7 0620/52/o/n/20 \u00a9 ucles 2020 [turn over 3\t\tbrass\tis\ta\tmixture\tof\ttwo\tmetals,\tcopper\tand\tzinc.   copper does not react with dilute sulfuric acid. zinc reacts with hot dilute sulfuric acid to form the  soluble\tsalt\tzinc\tsulfate. \t\tplan\tan\tinvestigation\tto\tfind\tthe\tpercentage\tby\tmass\tof\tzinc\tin\ta\tsample\tof\tbrass. \t\tin\tyour\tanswer\tyou\tshould\tinclude\thow\tto\tcalculate\tthe\tpercentage\tby\tmass\tof\tzinc.   you have access to normal laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6]",
            "8": "8 0620/52/o/n/20 \u00a9 ucles 2020blank page",
            "9": "9 0620/52/o/n/20 \u00a9 ucles 2020blank page",
            "10": "10 0620/52/o/n/20 \u00a9 ucles 2020blank page 2  you are provided with two metal salt solutions, e and f.   carry out the following tests on e and f, recording all of your observations at each stage.",
            "11": "11 0620/52/o/n/20 \u00a9 ucles 2020notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/52/o/n/20 \u00a9 ucles 2020tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w20_qp_53.pdf": {
            "1": "*7124984175* chemistry  0620/53 paper 5 practical test october/november 2020  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib20 11_0620_53/2rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/53/o/n/20 \u00a9 ucles 2020 1  you are going to investigate the reaction between dilute ethanoic acid and two different solutions of  sodium hydroxide labelled solution a and solution b.   read all of the instructions carefully before starting the experiments.  instructions   you are going to do two experiments.  (a) experiment 1  \u25cf rinse the burette with solution a.  \u25cf fill the burette with solution  a. run some of solution a out of the burette so that the level  of solution a is on the burette scale.  \u25cf use the measuring cylinder to pour 25 cm3 of dilute ethanoic acid into the conical flask.  \u25cf add five drops of thymolphthalein indicator to the conical flask.  \u25cf record the initial burette reading in the table.  \u25cf slowly add solution a from the burette to the conical flask, while swirling the flask, until the  solution just changes colour.  \u25cf record the final burette reading in the table and complete the table. experiment 1 final burette reading / cm3 initial burette reading / cm3 volume of solution a added / cm3  experiment 2  \u25cf empty the conical flask and rinse it with distilled water.  \u25cf empty the burette and rinse it with distilled water.  \u25cf rinse the burette with solution b.  \u25cf fill the burette with solution  b. run some of solution b out of the burette so that the level  of solution b is on the burette scale.  \u25cf use the measuring cylinder to pour 25 cm3 of dilute ethanoic acid into the conical flask.  \u25cf add five drops of thymolphthalein indicator to the conical flask.  \u25cf record the initial burette reading in the table.  \u25cf slowly add solution b from the burette to the conical flask, while swirling the flask, until the  solution just changes colour.  \u25cf record the final burette reading in the table and complete the table. experiment 2 final burette reading / cm3 initial burette reading / cm3 volume of solution b added / cm3  [4]",
            "3": "3 0620/53/o/n/20 \u00a9 ucles 2020 [turn over  (b)  state the colour change observed in the conical flask in experiment 2.  from . to  ...   [1]  (c)  explain why universal indicator is not a suitable indicator to use in this titration.      ..   [1]  (d) (i)  state which solution of sodium hydroxide, solution a or solution b, is the more concentrated.   explain your answer.   .   ...   [1]  (ii)  state how many times more concentrated this solution of sodium hydroxide is compared  to the other solution of sodium hydroxide.   .   ...   [1]  (e)  determine the volume of solution b that would be required if experiment 2 was repeated with  10 cm3 of dilute ethanoic acid.      ..   [2]  (f)  describe how the reliability of the results could be checked.      ..   [1]  (g)  a 25 cm3 pipette can be used to measure the volume of a solution.  (i)  describe an advantage of using a 25 cm3 pipette to measure the volume of the  dilute ethanoic acid.   .   ...   [1]  (ii)  explain why a 25 cm3 pipette could not be used to measure the volume of solution a.   .   ...   [1]",
            "4": "4 0620/53/o/n/20 \u00a9 ucles 2020  (h) (i)  explain why the burette was rinsed with distilled water in experiment 2.   .   ...   [1]  (ii)  explain why the burette was then rinsed with solution b.   .   ...   [1]  (iii)  state the effect that not rinsing the burette with solution b would have on the final burette  reading.   explain your answer.  effect  ...  explanation  .   .  [2]  [total: 17]",
            "5": "5 0620/53/o/n/20 \u00a9 ucles 2020 [turn over 2  you are provided with two solids, solid c and solid d.   do the following tests on solid c and solid d, recording all of your observations at each stage.   tests on solid c  (a)  describe the appearance of solid c.   ..   [1]  (b)  place about half of solid c in a hard\u2011glass test\u2011tube. heat the solid gently and then strongly.   record your observations.            ..   [3]  (c)  place the remaining half of solid c in a boiling tube. add about 10 cm3 of distilled water to the   boiling tube. stopper the boiling tube and shake it to dissolve solid c to form solution c.   divide solution c into two approximately equal portions in two test\u2011tubes.  (i)  add a few drops of universal indicator solution to the first portion of solution c.   record your observations.   .   ...   [1]  (ii)  add a spatula measure of solid sodium hydrogencarbonate to the second portion of  solution c.    test any gas formed.   record your observations.   .   .   .   ...   [3]  (d)  what conclusions can you make about solid c?      ..   [2]",
            "6": "6 0620/53/o/n/20 \u00a9 ucles 2020  tests on solid d   add solid  d to about 10 cm3 of distilled water in a boiling tube. stopper the boiling tube and shake  it to dissolve solid d to form solution d.   divide solution d into four approximately equal portions in four test\u2011tubes.  (e) (i)  add a few drops of aqueous sodium hydroxide to the first portion of solution d.   record your observations.   ...   [1]  (ii)  now add an excess of aqueous sodium hydroxide to the mixture.   record your observations.   ...   [1]  (f)  add excess aqueous ammonia to the second portion of solution d.   record your observations.   ..   [1]  (g)  add about 1 cm depth of dilute nitric acid and a few drops of aqueous silver nitrate to the third  portion of solution d.   record your observations.   ..   [1]  (h)  add about 1 cm depth of dilute nitric acid and a few drops of aqueous barium nitrate to the  fourth portion of solution d.   record your observations.   ..   [1]  (i)  identify solid d.   ..   [2]  [total: 17]",
            "7": "7 0620/53/o/n/20 \u00a9 ucles 2020 [turn over 3  a toothpaste contains:  \u25cf sodium fluoride  \u25cf calcium carbonate  \u25cf silica  \u25cf mint flavouring.   sodium fluoride and the mint flavouring are soluble in water.   calcium carbonate and silica are insoluble in water.   calcium carbonate reacts with dilute hydrochloric  acid to form the soluble salt calcium chloride.   plan an investigation to find the percentage by mass of silica in the toothpaste.   in your answer you should include how you will calculate the percentage by mass of silica in the  toothpaste.   you have access to normal laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/53/o/n/20 \u00a9 ucles 2020blank page",
            "9": "9 0620/53/o/n/20 \u00a9 ucles 2020blank page",
            "10": "10 0620/53/o/n/20 \u00a9 ucles 2020blank page 2  you are provided with two metal salt solutions, e and f.   carry out the following tests on e and f, recording all of your observations at each stage.",
            "11": "11 0620/53/o/n/20 \u00a9 ucles 2020notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/53/o/n/20 \u00a9 ucles 2020tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w20_qp_61.pdf": {
            "1": "*9389523754* chemistry  0620/61 paper 6 alternative to practical october/november 2020  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib20 11_0620_61/3rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/61/o/n/20 \u00a9 ucles 2020blank page",
            "3": "3 0620/61/o/n/20 \u00a9 ucles 2020 [turn over 1  the table gives the boiling points of four alcohols. alcohol boiling point / \u00b0c butanol 117 ethanol 79 pentanol 138 propanol 97   the apparatus shown can be used to obtain propanol from a mixture containing butanol, ethanol,  pentanol and propanol. a b mixture of alcohols electric heateralcohol collecte d water  (a)  name the items of apparatus labelled a and b.  a    b    [2]  (b)  name this method of separation.   ..   [2]  (c)  explain why it is safer to heat the mixture of alcohols in the way shown rather than with a  bunsen burner.   ..   [1]",
            "4": "4 0620/61/o/n/20 \u00a9 ucles 2020  (d)  describe how propanol can be obtained from the mixture. use data from the table.         ..   [2]  (e)  explain why the apparatus in the diagram cannot be used to obtain butanol from the mixture.      ..   [1]  [total: 8]",
            "5": "5 0620/61/o/n/20 \u00a9 ucles 2020 [turn over 2  a student investigated the mass of lead( ii) iodide precipitate formed when aqueous potassium iodide  reacts with aqueous lead( ii) nitrate.   the equation for the reaction is shown. 2ki(aq)  +  pb(no3)2(aq)  \u2192  pbi2(s)  +  2kno3(aq)   the student did seven experiments.   experiment 1  \u25cf using a 50 cm3 measuring cylinder, 25 cm3 of aqueous potassium iodide was poured into a  beaker.  \u25cf using a clean 50 cm3 measuring cylinder, 10 cm3 of aqueous lead( ii) nitrate was added to the  aqueous potassium iodide in the beaker. the solutions were mixed together.  \u25cf the mass of the precipitate of lead( ii) iodide formed was found.   experiment 2  \u25cf experiment 1 was repeated using a larger volume of aqueous lead( ii) nitrate than in  experiment 1.   experiment 3  \u25cf experiment 1 was repeated using a larger volume of aqueous lead( ii) nitrate than in  experiment 2.   experiment 4  \u25cf experiment 1 was repeated using a larger volume of aqueous lead( ii) nitrate than in  experiment 3.   experiment 5  \u25cf experiment 1 was repeated using a larger volume of aqueous lead( ii) nitrate than in  experiment 4.   experiment 6  \u25cf experiment 1 was repeated using a larger volume of aqueous lead( ii) nitrate than in  experiment 5.   experiment 7  \u25cf experiment 1 was repeated using a larger volume of aqueous lead( ii) nitrate than in  experiment 6.",
            "6": "6 0620/61/o/n/20 \u00a9 ucles 2020  (a)  use the measuring cylinder diagrams to complete the table. experimentvolume of aqueous  potassium iodide / cm3measuring cylinder  diagram for aqueous  lead( ii) nitratevolume of  aqueous lead( ii)  nitrate / cm3mass of lead( ii)  iodide precipitate / g 1 25 10 1.4 2 2520 102.3 3 2530 203.3 4 2530 204.1 5 2540 305.1 6 2550 405.1 7 2550 405.1  [2]",
            "7": "7 0620/61/o/n/20 \u00a9 ucles 2020 [turn over  (b)  plot the results from experiments 1 to 7 on the grid. draw two straight lines through the points.  extend your straight lines so that they meet. 01 02 03 04 0 volume of aqueous lead (ii) nitrate  / cm3mass of lead( ii) iodide precipitate  / g 506.0 5.0 4.0 3.0 2.0 1.0 0.0  [5]  (c)  from your graph, deduce the mass of lead( ii) iodide precipitate that would be formed if  experiment 1 was repeated using 20 cm3 of aqueous lead( ii) nitrate.   show clearly on the grid  how you worked out your answer.  mass = .. g  [2]  (d)  explain why the same mass of precipitate is formed in experiment 5, experiment 6 and  experiment 7.      ..   [1]  (e)  sketch on the grid the graph you would expect if all of the experiments were repeated using  aqueous potassium iodide with half the concentration. [2]",
            "8": "8 0620/61/o/n/20 \u00a9 ucles 2020  (f) (i)  state why using a 25.0 cm3 pipette to measure the volume of aqueous potassium iodide  would be an improvement.   .   ...   [1]  (ii)  state why a 25.0 cm3 pipette could not be used to measure the volume of  aqueous lead( ii) nitrate in each experiment.   .   ...   [1]  (g)  describe how the solid lead( ii) iodide can be separated from the reaction mixture and its mass  found.                  ..   [3]  [total: 17]",
            "9": "9 0620/61/o/n/20 \u00a9 ucles 2020 [turn over 3  solid y and solid z were analysed.   tests were done on each solid. tests on solid y observations solid y was dissolved in distilled water to form  solution y. solution y was divided into four  portions in four boiling tubes. test 1 aqueous ammonia was added dropwise and  then in excess to the first portion of solution y.a white precipitate formed which was insoluble in excess test 2 aqueous sodium hydroxide was added  dropwise and then in excess to the second  portion of solution y.a white precipitate formed which dissolved in excess to form a colourless solution test 3 a piece of aluminium foil was added to the  solution formed in test 2. the mixture was  warmed and any gas given off was tested.the gas turned damp red litmus paper blue test 4 about 1 cm3 of dilute nitric acid and a few drops  of aqueous silver nitrate were added to the third  portion of solution y.the solution remained colourless, no precipitate formed  (a)  name the gas given off in test 3.   ..   [1]  (b)  identify solid y.      ..   [2]  (c)  a strip of universal indicator paper was dipped into the fourth portion of solution y.   the universal indicator paper turned orange.   what additional information does this give about solution y?   ..   [1]",
            "10": "10 0620/61/o/n/20 \u00a9 ucles 2020  tests on solid z   solid z was iron( ii) sulfate.   complete the expected observations.   solid z was dissolved in water to produce solution z. solution z was split into three equal portions  in three boiling tubes.  (d)  aqueous ammonia was added dropwise and then in excess to the first portion of solution z.  observations  ..      ..   [2]  (e)  about 2 cm3 of dilute hydrochloric acid was added to the second portion of solution z.  observations     [1]  (f)  the solution from (e) was warmed and a piece of filter paper soaked in acidified aqueous  potassium manganate( vii) was held at the mouth of the boiling tube.  observations     [1]  (g)  about 1 cm3 of dilute nitric acid followed by a few drops of aqueous barium nitrate were added  to the third portion of solution z.  observations     [1]  [total: 9]",
            "11": "11 0620/61/o/n/20 \u00a9 ucles 2020 [turn over 4  a mixture contains three solid compounds:  \u25cf copper( ii) sulfate  \u25cf cetyl alcohol  \u25cf silicon dioxide.   the table gives some information on the solubility of these three solids. name of compoundsolubility in watersolubility in propanone copper( ii) sulfate soluble insoluble cetyl alcohol insoluble soluble silicon dioxide insoluble insoluble   plan a method to obtain a pure sample of each of the three solids, copper( ii) sulfate, cetyl alcohol  and silicon dioxide, from the mixture.   you have access to normal laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "12": "12 0620/61/o/n/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w20_qp_62.pdf": {
            "1": "*8955238231* chemistry  0620/62 paper 6 alternative to practical october/november 2020  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib20 11_0620_62/rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/62/o/n/20 \u00a9 ucles 2020 1  the diagram shows the apparatus used to pass an electric current through  concentrated hydrochloric acid. hydrogen and chlorine were formed at the electrodes. power supply+\u2013 aswitch  (a)  name the item of apparatus labelled a.   ..   [1]  (b)  the electrodes were made of platinum.  (i)  give two reasons why platinum is a suitable material for the electrodes.  1  ..  2  ..  [2]  (ii)  suggest another material suitable to use as electrodes in this experiment.   ...   [1]  (c)  the teacher doing this experiment wore safety glasses, gloves, had their hair tied back and  stood up throughout the experiment.   state one other safety precaution that should be taken when doing this experiment.   explain your answer.  safety precaution  ...  explanation    [2]  [total: 6]",
            "3": "3 0620/62/o/n/20 \u00a9 ucles 2020 [turn over 2\t\ta\tstudent\tinvestigated \tthe\trate\tof\ta\treaction\t between\t sodium\tmetabisulfite\t and\tpotassium\t iodate.\t in\tthe\treaction,\t starch\twas\tused\tas\tan\tindicator.\t at\tfirst\tthe\treacting\t mixture\tremained\t colourless\t but then suddenly changed to a blue-black colour.   five experiments were done. in each experiment the total volume of liquid was 45 cm3.   experiment 1  \u25cf using a 10 cm3 measuring cylinder, 5 cm3 of aqueous sodium metabisulfite was poured into a  beaker.  \u25cf using another 10 cm3 measuring cylinder, 5 cm3 of aqueous starch was poured into the beaker.  \u25cf using a 25 cm3 measuring cylinder, 15 cm3 of distilled water was poured into the beaker.  \u25cf using another 25 cm3 measuring cylinder, 20 cm3 of aqueous potassium iodate was poured into  the beaker. at the same time a stop-clock was started.  \u25cf the mixture in the beaker was stirred until a sudden colour change was seen.  \u25cf the stop-clock was immediately stopped and the time recorded.  \u25cf the beaker was rinsed with water.   experiment 2  \u25cf experiment 1 was repeated using 17 cm3 of distilled water and 18 cm3 of   aqueous potassium iodate.   experiment 3  \u25cf experiment 1 was repeated using 21 cm3 of distilled water and 14 cm3 of   aqueous potassium iodate.   experiment 4  \u25cf experiment 1 was repeated using 23 cm3 of distilled water and 12 cm3 of   aqueous potassium iodate.   experiment 5  \u25cf experiment 1 was repeated using 25 cm3 of distilled water and 10 cm3 of   aqueous potassium iodate.",
            "4": "4 0620/62/o/n/20 \u00a9 ucles 2020  (a)  use the information in the description of the experiments and the stop-clock diagrams to  complete the table. record the times in seconds. experimentvolume of  aqueous sodium  metabisulfite / cm3volume of distilled water / cm3volume of  aqueous  potassium  iodate / cm3stop-clock diagramtime to change colour / s 1 200 0 10 3015 1545 5second s minutes 2 180 0 10 3015 1545 5 3 140 0 10 3015 1545 5 4 120 0 10 3015 1545 5 5 100 0 10 3015 1545 5  [5]",
            "5": "5 0620/62/o/n/20 \u00a9 ucles 2020 [turn over  (b)  plot the results from experiments 1 to 5 on the grid. \t \tdraw\ta\tsmooth\tcurve\tof\tbest\tfit.\t 10 12 14 16 18 volume of aqueous potassium iodate  / cm3time to change colour  / s 20 2280 70 60 50 40 30  [3]  (c) (i)  from your graph, predict the time to change colour if 16 cm3 of aqueous potassium iodate  was used.   show clearly on the grid  how you worked out your answer.  time to change colour = .. s  [2]   (ii)  calculate the volume of distilled water required if 16 cm3 of aqueous potassium iodate was  used.  volume of distilled water = .. cm3  [1]  (d)  sketch on the grid the graph you would expect if experiments 1 to 5 were repeated at a higher  temperature. [1]",
            "6": "6 0620/62/o/n/20 \u00a9 ucles 2020  (e)  the concentration of potassium iodate in the reaction mixture in each experiment can be  calculated using the equation shown. concentration =0.05 \u00d7 volume of aqueous potassium iodate 45  (i)  calculate the concentration of potassium  iodate in the reaction mixture in experiment 2.  concentration = .. mol / dm3  [1]  (ii)  state which experiment, 1, 2, 3, 4 or 5, had the fastest rate of reaction.   ...   [1]  (f)  suggest why the volume of distilled water added to each experiment was increased as the  volume of aqueous potassium iodate was decreased.      ..   [1]  (g)  give one change you could make to the apparatus used which would improve the results.   explain your answer.  change to apparatus  ..     explanation       [2]  (h)  how could the reliability of the results of this investigation be checked?      ..   [1]  [total: 18]",
            "7": "7 0620/62/o/n/20 \u00a9 ucles 2020 [turn over 3  solid q and solid r were analysed. solid q was zinc carbonate.   tests were done on each solid.   tests on solid q   complete the expected observations.  (a)  solid q was placed in a boiling tube. about 10 cm3 of dilute sulfuric acid was added to the  boiling tube. any gas produced was tested.   the contents of the boiling tube were kept for (c).  observations  ..      ..   [3]  (b)  identify the gas given off in (a).   ..   [1]  (c)  the reaction mixture from (a)\twas\tfiltered. \t \tthe\tfiltrate\twas\tsolution\t s. 1 cm depth of solution s was poured into a boiling tube.  (i)  aqueous sodium hydroxide was added dropwise and then in excess to solution s in the  boiling tube.  observations  ...   .   ...   [2]  (ii)  explain why it is not possible to identify the cation contained in solution s from your  observations in (c)(i).   .   ..    [1]  (iii)  suggest an additional test that can be done on solution s\tto\tconfirm\tthe\tcation\twas\tzn2+.   .   ...   [1]",
            "8": "8 0620/62/o/n/20 \u00a9 ucles 2020  tests on solid r   tests were done and the following observations were made. tests on solid r observations test 1 a\tflame\ttest\twas\tdone\ton\tsolid\t r. yellow\tflame solid r was dissolved in distilled water to  produce solution r. the solution was divided  into two equal portions in two test-tubes. test 2 about 1 cm3 of dilute nitric acid followed by a  few drops of aqueous silver nitrate were added  to\tthe\tfirst\tportion\tof\tsolution\tr.yellow precipitate formed test 3 the second portion of solution r was added to  1 cm3 of aqueous bromine in a test-tube.the solution changed colour from orange to brown  (d) identify solid r.      ..   [2]  [total: 10]",
            "9": "9 0620/62/o/n/20 \u00a9 ucles 2020 [turn over 4  brass is a mixture of two metals, copper and zinc. \t\tcopper\tdoes\tnot\treact\twith\tdilute\tsulfuric\tacid.\tzinc\treacts\twith\thot\tdilute\tsulfuric\tacid\tto\tform\tthe\t soluble salt zinc sulfate. \t\tplan\tan\tinvestigation\tto\tfind\tthe\tpercentage\tby\tmass\tof\tzinc\tin\ta\tsample\tof\tbrass.   in your answer you should include how to calculate the percentage by mass of zinc.   you have access to normal laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "10": "10 0620/62/o/n/20 \u00a9 ucles 2020blank page",
            "11": "11 0620/62/o/n/20 \u00a9 ucles 2020blank page",
            "12": "12 0620/62/o/n/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w20_qp_63.pdf": {
            "1": "*3930589971* chemistry  0620/63 paper 6 alternative to practical october/november 2020  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib20 11_0620_63/2rp \u00a9 ucles 2020 [turn overthis document has 12 pages. blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/63/o/n/20 \u00a9 ucles 2020 1  hot zinc reacts with steam to make zinc oxide and hydrogen gas.   a student wanted to use the apparatus shown to react zinc with steam and to collect the hydrogen. water and mineral wool zinc boiling tube b watera  (a)  name the items of apparatus labelled a and b.  a    b    [2]  (b)  state the purpose of the mineral wool.      ..   [1]  (c)  the apparatus shown is dangerous to use because of an error in the way it has been set up.   identify this error.   explain why this error makes it dangerous to use the apparatus.  error  ...     explanation       [2]",
            "3": "3 0620/63/o/n/20 \u00a9 ucles 2020 [turn over  (d)  add two arrows to the diagram to show the two places where the apparatus should be heated  once the error in (c) has been corrected. [1]  (e)  describe the test for hydrogen gas.  test  .  result  ..  [2]  [total: 8]",
            "4": "4 0620/63/o/n/20 \u00a9 ucles 2020 2  a student investigated the reaction between dilute ethanoic acid and two different solutions of  sodium hydroxide labelled solution a and solution b.   two experiments were done.  (a) experiment 1  \u25cf a burette was rinsed with solution a.  \u25cf the burette was filled with solution a. some of solution a was run out of the burette so that  the level of solution a was on the burette scale.  \u25cf using a measuring cylinder, 25 cm3 of dilute ethanoic acid was poured into a conical flask.  \u25cf five drops of thymolphthalein indicator were added to the conical flask.  \u25cf solution a was added slowly from the burette to the conical flask, while the flask was  swirled, until the solution just changed colour.   use the burette diagrams to complete the table for experiment 1. 0 1 2 initial reading36 37 38 final reading experiment 1 final burette reading / cm3 initial burette reading / cm3 volume of solution a added / cm3",
            "5": "5 0620/63/o/n/20 \u00a9 ucles 2020 [turn over   experiment 2  \u25cf the conical flask was emptied and rinsed with distilled water.  \u25cf the burette was emptied and rinsed with distilled water.  \u25cf the burette was rinsed with solution b.  \u25cf the burette was filled with solution b. some of solution b was run out of the burette so that  the level of solution b was on the burette scale.  \u25cf using a measuring cylinder, 25 cm3 of dilute ethanoic acid was poured into a conical flask.  \u25cf five drops of thymolphthalein indicator were added to the conical flask.  \u25cf solution b was added slowly from the burette to the conical flask, while the flask was  swirled, until the solution just changed colour.   use the burette diagrams to complete the table for experiment 2. initial reading16 17 185 6 7 final reading experiment 2 final burette reading / cm3 initial burette reading / cm3 volume of solution b added / cm3  [4]  (b)  explain why universal indicator is not a suitable indicator to use in this titration.      ..   [1]  (c) (i)  state which solution of sodium hydroxide, solution a or solution b, was the more  concentrated.   explain your answer.   .   ...   [1]  (ii)  state how many times more concentrated this solution of sodium hydroxide was than the  other solution of sodium hydroxide.   .   ...   [1]",
            "6": "6 0620/63/o/n/20 \u00a9 ucles 2020  (d)  determine the volume of solution b that would be required if experiment 2 was repeated with  10 cm3 of dilute ethanoic acid.      ..   [2]  (e)  describe how the reliability of the results could be checked.      ..   [1]  (f)  a 25 cm3 pipette can be used to measure the volume of a solution.  (i)  describe an advantage of using a 25 cm3 pipette to measure the volume of the  dilute ethanoic acid.   .   ...   [1]  (ii)  explain why a 25 cm3 pipette could not be used to measure the volume of solution a.   .   ...   [1]  (g) (i)  explain why the burette was rinsed with distilled water in experiment 2.   .   ...   [1]  (ii)  explain why the burette was then rinsed with solution b.   .   ...   [1]  (iii)  state the effect that not rinsing the burette with solution b would have on the final burette  reading.   explain your answer.  effect  ...  explanation  .   .  [2]  [total: 16]",
            "7": "7 0620/63/o/n/20 \u00a9 ucles 2020 [turn over 3  two solids, solid c and solid d, were analysed.   tests were done on each solid.   tests on solid c   tests were done and the following observations were made. tests on solid c observations test 1 half of solid c was placed in a test\u2011tube. the  solid was heated gently and then strongly.steam was given off and condensation appeared at the mouth of the test\u2011tube, the remaining solid became black the remaining solid c was dissolved in  distilled water to produce solution c. the  solution was divided into two equal portions in  two test\u2011tubes. test 2 a few drops of universal indicator solution were  added to the first portion of solution c.the solution became orange test 3 a spatula measure of solid sodium carbonate  was added to the second portion of solution c.  any gas produced was tested.effervescence was seen, the gas turned limewater milky  (a)  suggest the ph of solution c.  ph = ..  [1]  (b)  identify the gas produced in test 3.   ..   [1]  (c)  what conclusions can you make about solid c?      ..   [2]",
            "8": "8 0620/63/o/n/20 \u00a9 ucles 2020  tests on solid d   solid d was calcium chloride.   complete the expected observations.   solid d was dissolved in water to form solution d. solution d was divided into four approximately  equal portions in four test\u2011tubes.  (d) (i)  a few drops of aqueous sodium hydroxide were added to the first portion of solution d.  observations  .   [1]  (ii)  an excess of aqueous sodium hydroxide was added to the mixture from (d)(i).  observations  .   [1]  (e)  aqueous ammonia was added dropwise and then in excess to the second portion of solution d.  observations  ..   ..   [2]  (f)  about 1 cm3 of dilute nitric acid and a few drops of aqueous silver nitrate were added to the  third portion of solution d.  observations     [1]  (g)  about 1 cm3 of dilute nitric acid and a few drops of aqueous barium nitrate were added to the  fourth portion of solution d.  observations     [1]  [total: 10]",
            "9": "9 0620/63/o/n/20 \u00a9 ucles 2020 [turn over 4  a toothpaste contains:  \u25cf sodium fluoride  \u25cf calcium carbonate  \u25cf silica  \u25cf mint flavouring.   sodium fluoride and the mint flavouring are soluble in water.   calcium carbonate and silica are insoluble in water.   calcium carbonate reacts with dilute hydrochloric  acid to form the soluble salt calcium chloride.   plan an investigation to find the percentage by mass of silica in the toothpaste.   in your answer you should include how you will calculate the percentage by mass of silica in the  toothpaste.   you have access to normal laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "10": "10 0620/63/o/n/20 \u00a9 ucles 2020blank page",
            "11": "11 0620/63/o/n/20 \u00a9 ucles 2020blank page",
            "12": "12 0620/63/o/n/20 \u00a9 ucles 2020blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        }
    },
    "2021": {
        "0620_m21_qp_12.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 03_0620_12/4rp   \u00a9 ucles 2021   [turn ove r   *8684920146*cambridge igcse\u2122       chemistry 0620/12     paper 1 multiple choice (core)  february/march 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/12/f/m/21  1 in which changes do the particles move further apart?    w  x   gas       liquid      solid   y  z     a w and x b w and z c x and y d y and z    2 gases are separated from liquid air by fractional distillation .    the boiling points of four gases are shown.    which gas is both monoatomic and a liquid at \u2013200  \uf0b0c?     g a s  boiling  point  / \uf0b0c  a argon \u2013186  b helium \u2013269  c neon \u2013246  d nitrogen \u2013196      3 impurities change the melting and boiling points of substances .    sodium chloride is added to a sample of pure water.    how does the addition of sodium chloride affect the melting poi nt and the boiling point of the  water?     melting point boiling point  a increases increases  b decreases decreases  c increases decreases  d decreases increases     ",
            "3": "3     \u00a9 ucles 2021 0620/12/f/m/21 [turn over  4 the apparatus used to separate a mixture of sand, methanol and ethanol is shown.    p qrs     which row identifies the labels on the diagrams?     p  q  r  s   a filtrate residue condenser fractionating column  b filtrate residue fractionating column condenser  c residue filtrate condenser fractionating column  d residue filtrate fractionating column condenser      5 a neutral atom, j, contains 45 neutrons and 35 electrons.    which row is correct for atom j?     proton number nucleon number  a 35 45  b 35 80  c 45 45  d 45 80     6 lithium and fluorine react to form lithium fluoride.    a student writes three statements about the reaction.    1 lithium atoms lose an electron when they react.  2 each fluoride ion has one more electron than a fluorine atom.   3 lithium fluoride is a mixture of elements.    which statements are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     ",
            "4": "4  \u00a9 ucles 2021 0620/12/f/m/21  7 which definition of isotopes is correct?  a atoms of the same element that have the same number of electron s and nucleons  b atoms of the same element that have the same number of neutrons  and protons  c atoms of the same element that have the same number of protons but a different number of  electrons  d atoms of the same element that have the same number of protons but a different number of  nucleons     8 in which molecule are all the out er shell electrons from each a tom used to form covalent bonds?  a c h 4 b c l 2 c h 2o d n h 3      9 what is the balanced chemical equation for the reaction betwee n calcium and water?  a ca  +  h 2o  \uf0ae  caoh  +  h 2  b ca  +  h 2o  \uf0ae  ca(oh) 2  +  h 2  c ca  +  2h 2o  \uf0ae  caoh  +  h 2  d ca  +  2h 2o  \uf0ae  ca(oh) 2  +  h 2     10 a compound has the formula xf 2 and has a relative mass of 70.    what is element x?  a gallium  b germanium  c s u l f u r   d ytterbium    ",
            "5": "5     \u00a9 ucles 2021 0620/12/f/m/21 [turn over  11 the diagram shows a section of an overhead power cable.    aluminiumsteel ceramic     which statement explains why a particular substance is used?  a aluminium has a low density and is a good conductor of electri city.  b ceramic is a good conductor of electricity.  c steel can rust in damp air.  d steel is more dense than aluminium.     12 three substances are electrolysed using inert electrodes.    which substances produce hydrogen at the negative electrode?    1 concentrated hydrochloric acid  2 concentrated aqueous sodium chloride  3 dilute sulfuric acid    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "6": "6  \u00a9 ucles 2021 0620/12/f/m/21  13 which row describes an endothermic reaction?     energy level diagram energy transfer  a energy progress of reaction energy is transferred  from the surroundings  to the reaction  b energy progress of reaction energy is transferred  from the surroundings  to the reaction  c energy progress of reaction energy is transferred  from the reaction  to the surroundings  d energy progress of reaction energy is transferred  from the reaction  to the surroundings    ",
            "7": "7     \u00a9 ucles 2021 0620/12/f/m/21 [turn over  14 fuels release heat energy when they burn.    which substances are used as fuels?    1 argon  2 butane 3 hydrogen 4 methane    a 1 and 3 only b 1, 3 and 4 c 2, 3 and 4 d 2 and 4 only     15 when zinc carbonate is mixed with dilute hydrochloric acid a c hange, m, takes place.    when carbon is heated with copper( ii) oxide a change, n, takes place.    which row describes changes m and n?     m  n   a chemical chemical  b chemical physical  c physical chemical  d physical physical      16 the apparatus shown is used to measure the rate of a reaction.     gas syringe reactants     which equation represents a reaction where the rate can be meas ured using this apparatus?  a mg(s)  +  2hc l (aq)  \uf0ae  mgc l 2(aq)  +  h 2(g)  b h c l (aq)  +  naoh(aq)  \uf0ae  nac l (aq)  +  h 2o(l)  c fe(s)  +  cuso 4(aq)  \uf0ae  cu(s)  +  feso 4(aq)  d 2na(s)  +  br 2(l)  \uf0ae  2nabr(s)    ",
            "8": "8  \u00a9 ucles 2021 0620/12/f/m/21  17 p is a hydrated metal salt with a blue colour. when p is heated , water is given off, leaving   solid q.    r is a hydrated metal salt with a pink colour. when r is heated , water is given off, leaving solid s.    which row gives the name of p and the colour of s?     name of p colour of s  a hydrated cobalt( ii) chloride blue  b hydrated cobalt( ii) chloride white  c hydrated copper( ii) sulfate blue  d hydrated copper( ii) sulfate white     18 which property is shown by the alkali sodium hydroxide?  a it has a ph less than ph 7.  b it produces a gas when it is warmed with ammonium chloride.  c it turns blue litmus red.  d it turns universal indicator green.     19 part of the periodic table is shown.    which element forms an acidic oxide?    ab cd      20 when aqueous sodium hydroxide is added to a solution of a metal  ion, a grey-green precipitate  forms, which dissolves in excess  to form a dark green solution.     what is the identity of the metal ion?  a chromium( iii)  b iron( ii)  c iron( iii)  d copper( ii)     ",
            "9": "9     \u00a9 ucles 2021 0620/12/f/m/21 [turn over  21 which statements describe the periodic table?    1 the elements are arranged in order of their nucleon number.  2 the elements are arranged in order of their proton number.  3 it is used to predict the properties of elements.    a 1 and 3 b 1  o n l y  c 2 and 3 d 2  o n l y     22 which row shows how the properties of the group i elements cha nge on descending the group?     density melting point reactivity  a decreases increases increases  b decreases increases decreases  c increases decreases increases  d increases decreases decreases     23 copper is a transition element.    two compounds of copper are copper( ii) oxide and copper( ii) carbonate.    which row describes the two compounds?     copper( ii) oxide colour of  copper( ii) carbonate  a acidic green  b acidic white  c basic green  d basic white     24 the metal beryllium does not react with cold water.    it reacts with hydrochloric acid but cannot be extracted from i ts ore by using carbon.    where is beryllium placed in the reactivity series?  magnesium  a  zinc  b  iron  c  copper  d ",
            "10": "10  \u00a9 ucles 2021 0620/12/f/m/21  25 pure iron is a soft metal.    when mixed with small amounts of tungsten it produces a hard al loy called tungsten steel.    which statements are correct?    1 pure iron is a transition element.  2 the particles in pure iron are arranged in ordered layers. 3 tungsten steel is a compound.    a 1, 2 and 3 b 1 and 2 only c 1  o n l y  d 2 and 3 only    26 which row describes magnesium?     electrical  conductivity reacts with  dilute acid  a low no  b low yes  c high no  d high yes     27 four equations are shown.    1 c  +  o 2  \uf0ae  co 2  2 caco 3  \uf0ae  cao  +  co 2  3 sio 2  +  2co  \uf0ae  si  +  2co 2  4 fe 2o3  +  3co  \uf0ae  2fe  +  3co 2    which equations represent reactions that take place during the extraction of iron from hematite?  a 1, 2 and 3 b 1, 2 and 4 c 2, 3 and 4 d 3 and 4 only      28 copper is used to make saucepans.    which properties of copper make it suitable for this use?    1 copper has a relatively high melting point.  2 copper has a low density. 3 copper is a good conductor of electricity. 4 copper is a good conductor of heat.    a 1 and 2 b 1 and 4 c 2 and 4 d 3 and 4    ",
            "11": "11     \u00a9 ucles 2021 0620/12/f/m/21 [turn over  29 which pollutants are responsible for the erosion of buildings a nd statues?    1 carbon monoxide  2 oxides of nitrogen  3 sulfur dioxide    a 1, 2 and 3 b 1 and 2 only c 2 and 3 only d 3  o n l y     30 which combination of chemical compounds can be used to produce  the fertiliser shown?    supergrown     p     k 21 16 8::     a ( n h 4)3po 4, kc l  b n h 4no 3, ca 3(po 4)2  c n h 4no 3, co(nh 2)2  d n h 4no 3, k2so 4, (nh 4)2so 4      31 x is produced when petrol burns completely in air.    what is x?  a argon  b carbon dioxide  c carbon monoxide  d hydrogen     32 which substance is used as a bleach in the manufacture of paper ?  a carbon dioxide  b nitrogen dioxide  c silicon dioxide  d sulfur dioxide    ",
            "12": "12  \u00a9 ucles 2021 0620/12/f/m/21  33 what is an industrial use of calcium carbonate?  a cracking of hydrocarbons  b manufacture of aluminium  c manufacture of cement  d purification of water      34 which product is formed when calcium carbonate undergoes therma l decomposition?  a calcium  b calcium hydroxide  c calcium oxide  d calcium silicate      35 the pie chart represents the composition of natural gas.    which sector represents methane?    abcd      36 which fraction, obtained from p etroleum, is used for jet fuel?  a b i t u m e n   b gasoline  c kerosene  d naphtha    ",
            "13": "13     \u00a9 ucles 2021 0620/12/f/m/21 [turn over  37 the formula of a hydrocarbon is c xhy.    the equation for its complete combustion is shown.    cxhy  +  8o 2  \uf0ae  5co 2  +  6h 2o    what are the values of x and y?     x  y   a 5 6  b 5 12  c 6 5  d 12 5     38 pentane is an alkane and pentene is an alkene.    what is observed when bromine water is added to a sample of eac h compound?     pentane pentene  a becomes colourless becomes colourless  b becomes colourless remains unchanged  c remains unchanged becomes colourless  d remains unchanged remains unchanged     39 molecule 1 undergoes a process to make molecule 2.     process  molecule 1     molecule 2    which row describes the molecules and the process?     molecule 1 process molecule 2  a monomer cracking polymer  b monomer polymerisation polymer  c small molecule polymerisation monomer  d small molecule cracking monomer     ",
            "14": "14  \u00a9 ucles 2021 0620/12/f/m/21  40 which substance has long-chain molecules and is a constituent of food?  a carbohydrate  b nylon  c poly(ethene)  d terylene     ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/12/f/m/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/12/f/m/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m21_qp_22.pdf": {
            "1": "    this document has 20 pages. any blank pages are indicated.  ib21 03_0620_22/3rp   \u00a9 ucles 2021   [turn ove r   *6167454403*cambridge igcse\u2122       chemistry 0620/22     paper 2 multiple choice (extended)  february/march 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/22/f/m/21  1 which row about a change of state is correct?     change of state energy change process  a solid \uf0ae liquid heat given out melting  b gas \uf0ae liquid heat taken in evaporation  c solid \uf0ae gas heat taken in sublimation  d liquid \uf0ae solid heat given out condensing      2 gases are separated from liquid air by fractional distillation .    the boiling points of four gases are shown.    which gas is both monoatomic and a liquid at \u2013200  \uf0b0c?     g a s  boiling  point  / \uf0b0c  a argon \u2013186  b helium \u2013269  c neon \u2013246  d nitrogen \u2013196     ",
            "3": "3     \u00a9 ucles 2021 0620/22/f/m/21 [turn over  3 two different food colourings, x and y, are tested using chrom atography.    three pure dyes, 1, 2 and 3, are also tested.    the chromatogram is shown.    10 9876543210solvent front baseline x y dye 1dye 2dye 3    which statements are correct?    1 x and y both contain two or more dyes.  2 dyes 2 and 3 are present in both x and y.  3 the rf of dye 1 is 0.625.    a 1 and 2 only b 1 and 3 only c 1, 2 and 3 d 2 and 3 only      4 which statement about the atoms of all the isotopes of carbon i s correct?  a they are all radioactive.  b they have the same mass.  c they have the same number of neutrons.  d they have the same number of electrons in the outer shell.     ",
            "4": "4  \u00a9 ucles 2021 0620/22/f/m/21  5 which diagram represents the structure of silicon( iv) oxide?    ab cd       6 lithium and fluorine react to form lithium fluoride.    a student writes three statements about the reaction.    1 lithium atoms lose an electron when they react.  2 each fluoride ion has one more electron than a fluorine atom.   3 lithium fluoride is a mixture of elements.    which statements are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    7 how many electrons are used to form covalent bonds in a molecu le of methanol, ch 3oh?  a 5  b 6  c 8  d 10     ",
            "5": "5     \u00a9 ucles 2021 0620/22/f/m/21 [turn over  8 magnesium oxide has a high melting point.    carbon dioxide has a low melting point.    which row identifies the attractive forces that are broken when  these compounds are melted?     magnesium oxide carbon dioxide  a strong attractions between molecules weak attractions between a toms  b strong attractions between molecules weak attractions between m olecules  c strong attractions between ions weak attractions between atoms  d strong attractions between ions weak attractions between molecu les     9 the ionic half-equation for the formation of oxygen during the electrolysis of aluminium oxide is  shown.    x  o2\u2013  \uf0ae  o 2  +  y e\u2013    what are the values of x and y?     x y  a 1 2  b 1 4  c 2 2  d 2 4       10 a compound has the formula xf 2 and has a relative mass of 70.    what is element x?  a gallium  b germanium  c s u l f u r   d ytterbium     ",
            "6": "6  \u00a9 ucles 2021 0620/22/f/m/21  11 the diagram shows a section of an overhead power cable.    aluminiumsteel ceramic     which statement explains why a particular substance is used?  a aluminium has a low density and is a good conductor of electri city.  b ceramic is a good conductor of electricity.  c steel can rust in damp air.  d steel is more dense than aluminium.     12 during the electrolysis of dilute sulfuric acid, hydrogen is co llected at the cathode.    what is the ionic half-equation for this reaction?  a h +  +  e\u2013  \uf0ae  h  b h+  \uf0ae  h  +  e\u2013  c 2 h+  +  2e\u2013  \uf0ae  h2  d 2 h+  \uf0ae  h2  +  2e\u2013     ",
            "7": "7     \u00a9 ucles 2021 0620/22/f/m/21 [turn over  13 which row describes an endothermic reaction?     energy level diagram energy transfer  a energy progress of reaction energy is transferred  from the surroundings  to the reaction  b energy progress of reaction energy is transferred  from the surroundings  to the reaction  c energy progress of reaction energy is transferred  from the reaction  to the surroundings  d energy progress of reaction energy is transferred  from the reaction  to the surroundings    ",
            "8": "8  \u00a9 ucles 2021 0620/22/f/m/21  14 the equation for the complete combustion of methane is shown.    ch 4(g)  +  2o 2(g)  \uf0ae  co 2(g)  +  2h 2o(g)    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013h +410  c=o +805  o\u2013h +460  o=o +496    what is the energy change for the reaction?  a \u2013818  kj / mol b \u2013 3 5 9  kj / mol c \u2013323  kj / mol d + 1 0 2  kj / mol    15 hydrogen fuel cells can be used to power cars.    which statements about a fuel cell are correct?    1 the balanced equation for the reaction is h 2  +  o 2  \uf0ae  h2o.  2 the fuel cell generates electricity. 3 in the fuel cell hydrogen is reduced.  4 the reactants are gases at room temperature.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4    ",
            "9": "9     \u00a9 ucles 2021 0620/22/f/m/21 [turn over  16 the apparatus shown is used to measure the rate of a reaction.     gas syringe reactants     which equation represents a reaction where the rate can be meas ured using this apparatus?  a mg(s)  +  2hc l (aq)  \uf0ae  mgc l 2(aq)  +  h 2(g)  b h c l (aq)  +  naoh(aq)  \uf0ae  nac l (aq)  +  h 2o(l)  c fe(s)  +  cuso 4(aq)  \uf0ae  cu(s)  +  feso 4(aq)  d 2na(s)  +  br 2(l)  \uf0ae  2nabr(s)      17 p is a hydrated metal salt with a blue colour. when p is heated , water is given off, leaving   solid q.    r is a hydrated metal salt with a pink colour. when r is heated , water is given off, leaving solid s.    which row gives the name of p and the colour of s?     name of p colour of s  a hydrated cobalt( ii) chloride blue  b hydrated cobalt( ii) chloride white  c hydrated copper( ii) sulfate blue  d hydrated copper( ii) sulfate white      18 magnesium reacts with copper( ii) oxide to give magnesium oxide and copper.    which substance is the oxidising agent in this reaction?  a copper  b copper( ii) oxide  c magnesium  d magnesium oxide    ",
            "10": "10  \u00a9 ucles 2021 0620/22/f/m/21  19 part of the periodic table is shown.    which element forms an acidic oxide?    ab cd       20 when aqueous sodium hydroxide is added to a solution of a metal  ion, a grey-green precipitate  forms, which dissolves in excess  to form a dark green solution.     what is the identity of the metal ion?  a chromium( iii)  b iron( ii)  c iron( iii)  d copper( ii)     21 which statements about strong acids are correct?    1 they have a high concentration of oh \u2013 ions.  2 they have a ph value of 1. 3 they completely ionise in water. 4 they turn red litmus blue.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    22 metal x reacts with non-metal y to form an ionic compound with the formula x 2y.    which statements are correct?    1 x is in group i of the periodic table.  2 x is in group ii of the periodic table. 3 y is in group vi of the periodic table.  4 y is in group vii of the periodic table.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    ",
            "11": "11     \u00a9 ucles 2021 0620/22/f/m/21 [turn over  23 the table gives some properties of group iv elements.    element    3density g/c m boiling point  / \uf0b0c  carbon 2.2 4827  silicon    germanium 5.3 2830  tin 5.8 2270  lead 11.3 1755    which row describes the properties of silicon?        3density g/c m boiling point  / \uf0b0c  a 2.3 3  265  b 3.1 1  997  c 6.2 2  920  d 24.6 11  682      24 the metal beryllium does not react with cold water.    it reacts with hydrochloric acid but cannot be extracted from i ts ore by using carbon.    where is beryllium placed in the reactivity series?  magnesium  a  zinc  b  iron  c  copper  d     25 why is cryolite used in the extraction of aluminium from bauxit e?  a as a catalyst for the process  b as a solvent for aluminium oxide  c it stops the carbon anodes burning away  d it reduces aluminium ions in aluminium oxide    ",
            "12": "12  \u00a9 ucles 2021 0620/22/f/m/21  26 which statements about the uses of metals are correct?    1 iron is used to make aircraft because iron has a low density.   2 copper is used to make electric cables because copper is a go od conductor of  electricity.  3 aluminium is used to make brass because aluminium is strong a nd hard.  4 iron is mixed with additives to  make an alloy used in chemica l plant.    a 1 and 2 b 3 and 4 c 1 and 3 d 2 and 4      27 which row describes the reactions of magnesium hydroxide and ma gnesium oxide?     effect of heat on hydroxide effe ct of heating oxide with carbo n  a forms magnesium oxide magnesium and carbon dioxide formed  b forms magnesium oxide no reaction  c no reaction magnesium and carbon dioxide formed  d no reaction no reaction      28 the properties of an element are listed.    its melting point is 3414  \uf0b0c.  some of its compounds are catalysts.  it has variable oxidation states.    where is the element found in the periodic table?  a alkali metals  b halogens  c noble gases  d transition elements     29 petrol burns in a car engine to produce waste gases which leave  through the car exhaust.    one of these waste gases is an oxide of nitrogen.    which statement describes how this oxide of nitrogen is formed?   a carbon dioxide reacts with nitrogen in the catalytic converter .  b nitrogen reacts with oxygen in the car engine.  c nitrogen reacts with oxygen in the catalytic converter.  d petrol combines with nitrogen in the car engine.   ",
            "13": "13     \u00a9 ucles 2021 0620/22/f/m/21 [turn over  30 which combination of chemical compounds can be used to produce  the fertiliser shown?    supergrown     p     k 21 16 8::     a ( n h 4)3po 4, kc l  b n h 4no 3, ca 3(po 4)2  c n h 4no 3, co(nh 2)2  d n h 4no 3, k2so 4, (nh 4)2so 4     31 which process does not produce carbon dioxide?  a combustion of a hydrocarbon  b photosynthesis  c reaction between an acid and a metal carbonate  d respiration     32 which substance is used as a bleach in the manufacture of paper ?  a carbon dioxide  b nitrogen dioxide  c silicon dioxide  d sulfur dioxide      33 what is an industrial use of calcium carbonate?  a cracking of hydrocarbons  b manufacture of aluminium  c manufacture of cement  d purification of water     ",
            "14": "14  \u00a9 ucles 2021 0620/22/f/m/21  34 propane reacts with chlorine.    which row shows a condition required for this reaction and iden tifies the type of reaction?     condition type of reaction  a phosphoric acid catalyst addition  b phosphoric acid catalyst substitution  c ultraviolet light addition  d ultraviolet light substitution     35 the pie chart represents the composition of natural gas.    which sector represents methane?    abcd       36 which statement describes the reaction between ethene and steam ?  a a cracking reaction which produces ethane and hydrogen gas as p roducts  b an addition reaction which produces ethanol as the only product   c an oxidation reaction which produces ethanoic acid as the only product  d a slow reaction producing ethanol and carbon dioxide     ",
            "15": "15     \u00a9 ucles 2021 0620/22/f/m/21 [turn over  37 the formula of a hydrocarbon is c xhy.    the equation for its complete combustion is shown.    cxhy  +  8o 2  \uf0ae  5co 2  +  6h 2o    what are the values of x and y?     x  y   a 5 6  b 5 12  c 6 5  d 12 5     38 the formula of an ester is ch 3ch 2ch 2cooch 2ch 2ch 3.    which acid and alcohol react together to make the ester?     acid alcohol  a butanoic acid butanol  b butanoic acid propanol  c propanoic acid butanol  d propanoic acid propanol     39 molecule 1 undergoes a process to make molecule 2.     process  molecule 1     molecule 2    which row describes the molecules and the process?     molecule 1 process molecule 2  a monomer cracking polymer  b monomer polymerisation polymer  c small molecule polymerisation monomer  d small molecule cracking monomer     ",
            "16": "16  \u00a9 ucles 2021 0620/22/f/m/21  40 which structure represents a protein?    co c co on hn ah nh co co co co n hn hco o co o b o c o d      ",
            "17": "17     \u00a9 ucles 2021 0620/22/f/m/21  blank page",
            "18": "18  \u00a9 ucles 2021 0620/22/f/m/21  blank page",
            "19": "19       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/22/f/m/21  blank page  ",
            "20": "20  \u00a9 ucles 2021 0620/22/f/m/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m21_qp_32.pdf": {
            "1": "*5071615272* chemistry  0620/32 paper 3 theory (core) february/march 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 03_0620_32/2rp \u00a9 ucles 2021 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/32/f/m/21 \u00a9 ucles 2021 1  the diagram shows part of the periodic table. iii iiiivvv iviiviii mg al arcl br icn of ca cr fe cuzn ptk   answer the following questions using only the symbols of the elements in the diagram.   each symbol may be used once, more than once or not at all.   give the symbol of the element that:  (a)  is extracted from bauxite   ..   [1]  (b)  forms 21% of clean, dry air   ..   [1]  (c)  forms an oxide which contributes to acid rain   ..   [1]  (d)  forms an aqueous ion that gives a red-brown precipitate on addition of aqueous   sodium hydroxide   ..   [1]  (e)  has an atom with a complete outer electron shell.   ..   [1]  [total: 5]",
            "3": "3 0620/32/f/m/21 \u00a9 ucles 2021 [turn over 2  the table shows the mass of some of the ions in a 1000 cm3 sample of sea water. name of ion formula of ionmass of ion in 1000 cm3 of sea water / mg bromide br \u201365 calcium ca2+400 chloride cl \u201318 980 hydrogencarbonate hco3\u2013140 magnesium mg2+1262 metaborate b3o63\u201326 k+380 sodium na+10 556 strontium sr2+13 so42\u20132649  (a)  answer these questions using only the information in the table.  (i)  state which negative ion has the lowest mass in 1000 cm3 of sea water.   ...   [1]  (ii)  give the formulae of the ions in potassium sulfate.   and  ...   [1]  (iii)  calculate the mass of calcium ions in 200 cm3 of this sample of sea water.  mass = .. mg  [1]  (iv)  a sample of this sea water is evaporated.   state the name of the compound which is present in the greatest quantity when this sample  is evaporated.   ...   [1]  (v)  give the name of the ion which reacts with aqueous silver nitrate to give a cream precipitate.   ...   [1]",
            "4": "4 0620/32/f/m/21 \u00a9 ucles 2021  (b)  the b3o63\u2013 ion can be converted to boric acid, h3bo3.   boric acid is also produced when boron trichloride, bc l 3, reacts with water.   complete the equation for this reaction.  bcl 3  +  .h2o  \u2192  h3bo3  +  .hc l [2]  (c)   the symbol of a strontium ion is shown. 87sr2+ 38   deduce the number of electrons, protons and neutrons in one atom of this strontium ion.   number of electrons  ...   number of protons  .   number of neutrons  ...  [3]  (d)  some isotopes of strontium are radioactive.  (i)  give one medical use of radioactive isotopes.   ...   [1]  (ii)  the isotope 235u is also radioactive.   state the major use of this isotope of uranium.   ...   [1]  [total: 12]",
            "5": "5 0620/32/f/m/21 \u00a9 ucles 2021 [turn over 3  the table shows some properties of four halogens. elementmelting point in \u00b0cboiling point in \u00b0cdensity of liquid at melting point in g / cm3 fluorine \u2013220 \u2013188 chlorine \u2013101 1.56 bromine \u20137 59 3.12 iodine 114 184 4.93  (a) (i) complete the table by predicting:  \u25cf the boiling point of chlorine  \u25cf the density of fluorine at its melting point.  [2]  (ii)  describe the trend in the melting points of the halogens down the group.   ...   [1]  (iii)  deduce the physical state of iodine at 130 \u00b0c.   explain your answer.   .   .   ...   [2]  (b) (i)\t \tgive\tthe\telectronic\tstructure\tof\ta\tfluorine \tatom.   ...   [1]  (ii)\t\texplain\twhy\ta\tfluoride\tion\thas\ta\tsingle\tnegative\tcharge.   .   ...   [1]  (c)\t\tmagnesium\treacts\twith\texcess\tfluorine\tto\tproduce\tmagnesium\tfluoride. \t \twhen\t2.40\t g\tof\tmagnesium\tis\treacted,\t6.20\t g\tof\tmagnesium\tfluoride\tis\tproduced. \t calculate\tthe\tmass\tof\tmagnesium\tneeded\tto\tproduce\t1.24\t g\tof\tmagnesium\tfluoride.  mass of magnesium = .. g  [1]  [to tal: 8]",
            "6": "6 0620/32/f/m/21 \u00a9 ucles 2021 4  a student investigates the reaction of magnesium powder with dilute hydrochloric acid. the  magnesium is in excess. mg  +  2hcl  \u2192  mgcl 2  +  h2   the rate of reaction can be found by measuring the increase in volume of hydrogen with time.   the results are shown on the graph. 40 30 20 10 0 02 04 06 0 time  / svolume of hydrogen / cm3 80 100 120 140  (a)\t\tdeduce\tthe\ttime\ttaken\tfor\tthe\treaction\tto\tfinish.  time taken = .. s  [1]  (b)  the experiment is repeated using dilute hydrochloric acid of a lower concentration.   draw a line on the grid to show how the volume of hydrogen changes with time using dilute  hydrochloric acid of a lower concentration.   all other conditions stay the same. [2]",
            "7": "7 0620/32/f/m/21 \u00a9 ucles 2021 [turn over  (c)\t\tdescribe\t the\teffect\teach\tof\tthe\tfollowing\t has\ton\tthe\trate\tof\treaction\t of\tmagnesium\t with\t hydrochloric acid.  \u25cf the temperature is increased.   all other conditions stay the same.   .  \u25cf magnesium ribbon is used instead of magnesium powder.   all other conditions stay the same.   .  [2]  (d)  hydrochloric acid reacts with calcium carbonate.   name the products of this reaction and give the observations.   products  .      observations  ..     [4]  [total: 9]",
            "8": "8 0620/32/f/m/21 \u00a9 ucles 2021 5  this question is about sulfur and compounds of sulfur.  (a)  sulfur is a non-metal.   describe three physical properties which are typical of non-metals.  1  .  2  .  3  .  [3]  (b)  name one source of sulfur.   ..   [1]  (c)\t\twhen\tcarbon\tis\theated\twith\tsulfur,\tcarbon\tdisulfide,\tcs2, is produced. c  +  2s  \u2192  cs2  (i)\t\tcomplete\t the\tenergy\tlevel\tdiagram\t for\tthe\tproduction\t of\tcarbon\tdisulfide\t by\twriting\tthese\t formulae on the diagram:  \u25cf c  +  2s  \u25cf cs2. energy progress of reaction  [1]  (ii)  explain, using information on the energy level diagram, how you know that this reaction is  endothermic.   ...   [1]",
            "9": "9 0620/32/f/m/21 \u00a9 ucles 2021 [turn over  (d)\t\tcarbon\tdisulfide\tis\ta\tliquid\tat\troom\ttemperature. \t \tdescribe\tthe\tseparation\tand\tmotion\tof\tthe\tparticles\tin\tcarbon\tdisulfide\tliquid.  separation  ..  motion    [2]  (e)\t\thydrogen\t sulfide\tis\ta\tgas\twhich\tturns\tfilter\tpaper\tsoaked\tin\taqueous\t lead( ii) ethanoate from  white to black. \t \thydrogen\tsulfide\tis\tslightly\tsoluble\tin\twater.   a long glass tube is set up as shown. long glass tube cotton wool soaked in aqueous hydrogen sulfidefilter paper soaked in aqueous lead( ii) ethanoate \t \tat\tfirst,\tthe\tfilter\tpaper\tsoaked\tin\taqueous\tlead( ii) ethanoate does not turn black. \t \tafter\ta\tshort\ttime,\tthe\tfilter\tpaper\tsoaked\tin\taqueous\tlead( ii) ethanoate turns black.   explain these observations using the kinetic particle model.               ..   [3]  (f)  sulfur dioxide is a pollutant in the air.  (i)  give one\tadverse\teffect\tof\tsulfur\tdioxide \ton\tbuildings.   ...   [1]  (ii)  sulfur dioxide is used to bleach paper.   give one other use of sulfur dioxide.   ...   [1]  [total: 13]",
            "10": "10 0620/32/f/m/21 \u00a9 ucles 2021 6  the structure of compound a is shown. o occh hc hcoh hhh c h  (a) (i)  on the structure of compound a, draw a circle around the carboxylic acid functional group.  [1]  (ii)  state the name of the carboxylic acid that has only two carbon atoms.   ...   [1]  (iii)  deduce the molecular formula of compound a to show the number of carbon, hydrogen  and oxygen atoms.   ...   [1]  (iv)  explain, by referring to its structure, why compound a is described as unsaturated.   ...   [1]  (b)  ethene is an unsaturated hydrocarbon.   draw the structure of ethene to show all of the atoms and all of the bonds.  [2]  (c)  ethene can be produced by cracking hydrocarbons.  (i)  state the meaning of the term cracking .   .   ...   [1]  (ii)  give the conditions required for cracking.  1  ..  2  ..  [2]",
            "11": "11 0620/32/f/m/21 \u00a9 ucles 2021 [turn over  (d)  ethene can be polymerised.   complete these sentences about the polymerisation of ethene using words from the list. addition       decomposition       neutralisation       poly(ethene) poly(ethane)       reduction       terylene   when ethene polymerises, it produces a molecule called ... .   the type of reaction which occurs is ... .  [2]  (e)  describe one pollution problem caused by non-biodegradable plastics.   ..   [1]  [total: 12]",
            "12": "12 0620/32/f/m/21 \u00a9 ucles 2021 7  sodium is manufactured by electrolysis.  (a)  explain why sodium is manufactured by electrolysis and not by reduction with carbon.   ..   [1]  (b)  the diagram shows the equipment for the production of sodium. +\u2013 power supplysodium molten sodium chlorid e  (i)  the anode is inert.   suggest a suitable substance that can be used for the anode.   ...   [1]  (ii)  label the anode on the diagram . [1]  (iii)  describe, by reference to the diagram, how you know that sodium is less dense than  molten sodium chloride.   ...   [1]  (c)  when concentrated aqueous sodium chloride is electrolysed, gases are produced at each  electrode.   state the names of the products and give the observations at each electrode.   product at the negative electrode  ..   observations at the negative electrode  ..      product at the positive electrode     observations at the positive electrode  ...     [4]",
            "13": "13 0620/32/f/m/21 \u00a9 ucles 2021 [turn over  (d)  give two\tways\tin\twhich\tthe\tphysical\t properties\t of\tsodium\tare\tdifferent\t from\tthe\tphysical\t properties of transition elements.  1  .  2  .  [2]  (e)  the symbol equation for the production of sodium hydride is shown. 2na  +  h2  \u2192  2nah  (i)  write a word equation for this reaction.   ...   [1]  (ii)  suggest why the hydrogen must be dry.   ...   [1]  (iii)\t\tsodium\thydride\treduces\tiron( iii) oxide to iron. fe2o3  +  3nah  \u2192  2fe  +  3naoh \t \texplain\thow\tthis\tequation\tshows\tthat\tiron( iii) oxide is reduced.   ...   [1]  (f)\t\tstate\tthe\tcolour\tobserved\tin\tthe\tflame\ttest\tfor\tsodium.   ..   [1]  [total: 14]",
            "14": "14 0620/32/f/m/21 \u00a9 ucles 2021 8  aqueous ammonia is an alkali.  (a)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  ammonia. h n hh  [2]  (b)  complete the word equation for the reaction of aqueous ammonia with dilute hydrochloric acid. ammonia +hydrochloric acid   [1]  (c)\t\tdescribe\t the\tcolour\tchange\twhen\texcess\taqueous\t ammonia\t is\tadded\tto\tan\tacidified\t solution\t of methyl orange.  from  to     [1]",
            "15": "15 0620/32/f/m/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (d)\t\taqueous\tammonia\treacts\twith\taqueous\tcopper( ii) ions to produce compound b.   the formula of compound b is cun4h16o2.   complete the table to calculate the relative molecular mass of compound b. type of atomnumber of atomsrelative atomic mass copper 1 64 1 \u00d7 64 = 64 nitrogen 4 14 4 \u00d7 14 = 56 hydrogen 1 oxygen 16  relative molecular mass = ..  [2]  (e)  ammonia is used in the production of fertilisers.   state why farmers put fertilisers on the soil where crops are to be grown.   ..   [1]  [total: 7]",
            "16": "16 0620/32/f/m/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_m21_qp_42.pdf": {
            "1": "*1443180407* chemistry  0620/42 paper 4 theory (extended) february/march 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 03_0620_42/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/42/f/m/21 \u00a9 ucles 2021 1  the table shows the numbers of protons, neutrons and electrons in particles a to i. particle protons neutrons electrons a 1 0 0 b 6 6 6 c 6 8 6 d 10 10 10 e 16 16 18 f 17 18 17 g 18 22 18 h 19 20 19 i 20 20 18   answer the following questions about particles a to i. each letter may be used once, more than  once or not at all.  (a)  state which of the particles a to i:  (i)  is an anion    [1]  (ii)  are cations   and   [2]  (iii)  are noble gas atoms  and   [2]  (iv)  is a halogen atom   [1]  (v)  is a group i atom   [1]  (vi)  have the same nucleon number  and   [1]  (vii)  causes acidity in aqueous solutions   [1]  (viii)\t\tis\tused\tto\tdefine\tthe\trelative\tatomic\tmass\tof\telements.\t \t\t[1]  (b)  explain why b and c are isotopes of the same element.      ..   [2]  [total: 12]",
            "3": "3 0620/42/f/m/21 \u00a9 ucles 2021 [turn over 2  the elements shown are gases at room temperature and pressure. hydrogen nitrogen oxygen chlorine  (a)  state which one of these gases is green.   ..   [1]  (b)  the gases shown exist as diatomic molecules.   state the name of another element which has diatomic molecules and is a gas at room  temperature and pressure.   ..   [1]  (c)\t\twhen\tseparate\tsamples\tof\teach\tof\tthese\tgases\tare \tplaced\tin\ta\tcontainer\tthey\twill\tdiffuse.  (i)\t\tdescribe\twhy\tthese\tgases\tdiffuse.   ...   [1]  (ii)\t\tstate\twhich\tof\tthese\tfour\tgases\thas\tthe\thighest\trate\tof\tdiffusion.   explain your answer.  gas  ..  explanation  .   .  [2]  (d)  nitrogen, oxygen and other substances are found in clean, dry air.  (i)  state the percentage of nitrogen in clean, dry air.    ...   [1]  (ii)  other than nitrogen and oxygen, identify another element found in clean, dry air.   ...   [1]  (iii)  identify a compound found in clean, dry air.   ...   [1]  (iv)  nitrogen and oxygen can be separated from liquid air.   state the name of this process.   ...   [2]  [total: 10]",
            "4": "4 0620/42/f/m/21 \u00a9 ucles 2021 3  this question is about ammonia.  (a)  nitrogen reacts with hydrogen to form ammonia in an industrial process. n2(g)  +  3h2(g)    2nh3(g)  (i)  name this industrial process.   ...   [1]  (ii)  state the meaning of the symbol .   ...   [1]  (iii)  state the conditions used in this industrial process. include units.  temperature  .  pressure  ...  [2]  (iv)  name the catalyst used in this industrial process.   ...   [1]  (v)  if the pressure is increased, the yield of ammonia increases.   explain why, in terms of equilibrium.   .   .   ...   [2]  (vi)  if the temperature is increased, the rate of reaction increases.   explain why, in terms of particles.   .   .   .   .   ...   [3]  (b)  ammonia reacts with sulfuric acid to make a compound which is used as a fertiliser.   write the chemical equation for the reaction between ammonia and sulfuric acid.   ..   [2]  [total: 12]",
            "5": "5 0620/42/f/m/21 \u00a9 ucles 2021 [turn over 4  a student wanted to make some zinc chloride crystals.   the student followed the procedure shown.  step 1  add excess zinc powder to dilute hydrochloric acid to form aqueous zinc chloride.  step 2  remove unreacted zinc powder from the aqueous zinc chloride.  step 3  heat the solution until it is saturated.  step 4  allow the saturated solution to cool and remove the crystals that form.  (a)  write the equation for the reaction in step 1. include state symbols.   ..   [3]  (b)  explain why excess  zinc powder is added in step 1.   ..   [1]  (c)  suggest how unreacted zinc powder is removed in step 2.   ..   [1]  (d)  a saturated solution is formed in step 3.   suggest what is meant by the term saturated solution .      ..   [2]  (e)  explain why crystals form as the solution cools in step 4.   ..   [1]  (f)  name two zinc compounds which react with dilute hydrochloric acid to form zinc chloride.      ..   [2]  (g)  if excess calcium metal is used instead of excess zinc powder in step 1, pure calcium chloride  crystals do not form.   explain why.      ..   [1]",
            "6": "6 0620/42/f/m/21 \u00a9 ucles 2021  (h)  some salts can be made by titration.   in a titration experiment, 20.0 cm3 of aqueous sodium hydroxide reacts exactly with 25.0 cm3 of  0.100 mol / dm3 dilute sulfuric acid to make sodium sulfate. 2naoh(aq)  +  h2so4(aq)  \u2192  na2so4(aq)  +  2h2o(l)  (i)  circle the name of the type of reaction that takes place. decomposition          neutralisation         precipitation         reduction  [1]  (ii)  calculate the concentration of the aqueous sodium hydroxide in g / dm3 using the following  steps.  \u25cf calculate the number of moles of dilute sulfuric acid used.  .. mol  \u25cf determine the number of moles of sodium hydroxide which react with the dilute  sulfuric acid.  .. mol  \u25cf calculate the concentration of the aqueous sodium hydroxide in mol / dm3.  .. mol / dm3  \u25cf calculate the concentration of the aqueous sodium hydroxide in g / dm3.  .. g / dm3  [5]  [total: 17]",
            "7": "7 0620/42/f/m/21 \u00a9 ucles 2021 [turn over question 5 starts on the next page.",
            "8": "8 0620/42/f/m/21 \u00a9 ucles 2021 5  the table shows the names or structures of organic compounds p to u. p q r hch hch hch hh propanoic acid but-1-ene s t u propan-1-ol methyl butanoate cch ch hhh h  (a)  give the letters of the organic compounds, p to u, that are unsaturated hydrocarbons.   ..   [2]  (b)  describe the test for an unsaturated hydrocarbon.  test  .  observations  ..  [2]  (c)  but-1-ene is an unbranched molecule.  (i)  name the unbranched isomer of but-1-ene.   ...   [1]  (ii)  draw the structure of a branched isomer of but-1-ene. show all of the atoms and all of the  bonds.  [1]  (d)  dodecane is an alkane with 12 carbon atoms. dodecane can be cracked.  (i)  write the formula of dodecane.   ...   [1]  (ii)  give the letters of all the organic compounds, p to u, that can be formed when dodecane  is cracked.   ...   [2]",
            "9": "9 0620/42/f/m/21 \u00a9 ucles 2021 [turn over  (e)  name the reagent and suggest the conditions needed to convert organic compound u into  organic compound s.  reagent  ..  conditions  ..  [3]  (f)  organic compound s can be converted to organic compound q\t by\treaction\t with\tan\tacidified\t reagent.  (i)  name the type of chemical change that happens to organic compound s.   ...   [1]  (ii)\t\tname\tthe\tacidified\treagent\tadded\tto\torganic\tcompound\t s.   ...   [1]  (g)  organic compound t is made by reacting two compounds together.  (i)  name the homologous series that organic compound t belongs to.   ...   [1]  (ii)  name the two compounds which react together to make organic compound t.   draw the structures of each compound you have named. show all of the atoms and all of  the bonds.  name  ...  structure  name  ...  structure  [4]  (iii)  deduce the molecular formula of organic compound t.   ...   [1]  [total: 20]",
            "10": "10 0620/42/f/m/21 \u00a9 ucles 2021 6  polymers are large molecules built up from small molecules.  (a)  state the name given to the small molecules from which polymers are made.   ..   [1]  (b)  the formula of a polymer is shown. nc ch3c ch3h h  (i)  draw the structure of the small molecule from which this polymer is made. show all of the  atoms and all of the bonds.  [2]  (ii)  state the type of polymerisation used to make this polymer.   ...   [1]  (c)  three amino acids are shown. they combine to form part of a natural polymer. h2n cooh h2n cooh h2n cooh  (i)  name the type of natural polymer formed when amino acids combine.   ...   [1]  (ii)  complete the diagram to show part of the structure of the natural polymer that forms when  these three amino acids combine. show all of the bonds in the linkages.  [3]  (iii)  name the type of chemical reaction that takes place when this natural polymer is converted  back to amino acids.   ...   [1]  [total: 9]",
            "11": "11 0620/42/f/m/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "12": "12 0620/42/f/m/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_m21_qp_52.pdf": {
            "1": "*3599589322* chemistry  0620/52 paper 5 practical test february/march 2021  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib21 03_0620_52/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/52/f/m/21 \u00a9 ucles 2021 1\t\tyou\tare\tgoing\tto\tinvestigate\t the\treaction\t between \taqueous\t potassium\t hydroxide\t and\ttwo\tdifferent\t aqueous solutions of hydrochloric acid labelled solution a and solution b.   read all of the instructions carefully before starting the experiments.   instructions   you are going to do two experiments.  (a)  experiment 1  \u25cf fill the burette with solution  a. run some of solution a out of the burette so that the level  of solution a is on the burette scale.  \u25cf record the initial burette reading in the table.  \u25cf use the measuring cylinder to pour 25 cm3 of aqueous potassium hydroxide into the  conical flask.  \u25cf add five drops of thymolphthalein indicator to the conical flask.  \u25cf slowly add solution a from the burette to the conical flask, while swirling the flask, until the  solution just changes colour.  \u25cf record the final burette reading in the table and complete the table. experiment 1 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of solution a\tadded\t /\tcm3   experiment 2  \u25cf empty the conical flask and rinse it with distilled water.  \u25cf empty the burette and rinse it with distilled water.  \u25cf rinse the burette with solution b.  \u25cf fill the burette with solution  b. run some of solution b out of the burette so that the level  of solution b is on the burette scale.  \u25cf record the initial burette reading in the table.  \u25cf use the measuring cylinder to pour 25 cm3 of aqueous potassium hydroxide into the  conical flask.  \u25cf add five drops of thymolphthalein indicator to the conical flask.  \u25cf slowly add solution b from the burette to the conical flask, while swirling the flask, until the  solution just changes colour.  \u25cf record the final burette reading in the table and complete the table. experiment 2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of solution b\tadded\t /\tcm3  [4]",
            "3": "3 0620/52/f/m/21 \u00a9 ucles 2021 [turn over  (b)\t\tstate\tthe\tcolour\tchange\tobserved\tin\tthe\tconical\tflask\tat\tthe\tend-point\tin\texperiment\t2.   from  to     [1]  (c)\t \tstate\tthe\tcolour\tchange\tobserved\tat\tthe\tend-point\tif\tmethyl\torange\tis\tused\tas\tthe\tindicator.   from  to     [1]  (d)\t\tbefore\tstarting\tthe\ttitration\tin\texperiment\t2\tthe\tconical\tflask\twas\trinsed\twith\twater.  (i)\t\texplain\twhy\tthe\tconical\tflask\twas\trinsed \twith\twater.   ...   [1]  (ii)\t\tthe\tconical\tflask\twas\tnot then rinsed with aqueous potassium hydroxide. \t \tstate\thow\trinsing\tthe\tconical\tflask\twith\taqueous\t potassium\t hydroxide\t would\tchange\tthe\t volume of solution b needed. explain your answer.   .   ...   [2]  (e) (i)  deduce which aqueous solution of hydrochloric acid, a or b, is more concentrated.   explain your answer.   .   ...   [1]  (ii)  deduce how many times more concentrated this solution of hydrochloric acid is than the  other solution of hydrochloric acid.   ...   [1]  (f)  explain why experiment 1 and experiment 2 should be repeated.      ..   [1]  (g)  deduce the volume of solution b required if experiment 2 is carried out with 50 cm3 of aqueous  potassium hydroxide.      ..   [2]",
            "4": "4 0620/52/f/m/21 \u00a9 ucles 2021  (h)  describe one change that could be made to the apparatus to improve the accuracy of the  results.      ..   [1]  (i)\t\tdescribe\twhat\teffect\tusing\ta\tlarger\tconical\tflask\twould\thave\ton\tthe\tresults\tobtained.   ..   [1]  [total: 16]",
            "5": "5 0620/52/f/m/21 \u00a9 ucles 2021 [turn over 2  you are provided with two solids, solid c and solid d.   do the following tests on the substances, recording all of your observations at each stage.   tests on solid c  (a)  describe the appearance of solid c.   ..   [1]  (b)\t\tconduct\ta\tflame\ttest\ton\tsolid\t c.   record your observations.   ..   [1]   transfer the remaining solid c to a boiling tube. add about 1 cm depth of distilled water to the  boiling tube containing solid c. place a stopper in the boiling tube and shake the tube to dissolve  solid c and form solution c.  (c)  add 5 cm3 of aqueous sodium hydroxide slowly to solution c.   keep the product for use in (d).   record your observations.   ..   [1]  (d)  pour about 2 cm depth of the product from (c) into a boiling tube. add a piece of aluminium foil  and warm the mixture gently. test and identify any gas produced.   record your observations.        identity of gas    [3]  (e)  identify solid c.      ..   [2]",
            "6": "6 0620/52/f/m/21 \u00a9 ucles 2021   tests on solid d  (f)  place solid d in a boiling tube. add about 10 cm3 of distilled water to the boiling tube. place a  stopper in the boiling tube and shake the tube to dissolve solid d and form solution d.   divide solution d\tinto\tfive\tapproximately\tequal\tportions\tin\tfive\ttest-tubes.  (i)\t\tto\tthe\tfirst\tportion\tof\tsolution\t d add aqueous sodium hydroxide dropwise and then in  excess.   record your observations.   .   ...   [2]  (ii)  to the second portion of solution d add aqueous ammonia dropwise and then in excess.   record your observations.   .   ...   [2]  (iii)  to the third portion of solution d add about 2 cm depth of aqueous sodium carbonate.   record your observations.   .   ...   [2]  (iv)  to the fourth portion of solution d add about 1 cm depth of dilute nitric acid followed by a  few drops of aqueous silver nitrate.   record your observations.   ...   [1]  (v)\t\tto\tthe\tfifth\tportion\tof\tsolution\t d add about 1 cm depth of dilute nitric acid followed by a few  drops of aqueous barium nitrate.   record your observations.   ...   [1]  (g)  identify solid d.      ..   [2]  [total: 18]",
            "7": "7 0620/52/f/m/21 \u00a9 ucles 2021 [turn over 3  old concrete contains calcium carbonate. calcium carbonate reacts with dilute hydrochloric acid. caco3(s)  +  2hcl (aq)  \u2192  cacl 2(aq)  +  h2o(l)  +  co2(g) \t\tplan\tan\tinvestigation\t to\tfind\twhich\tof\ttwo\tlumps\tof\tconcrete\t contains\t the\tlarger\tpercentage\t of\t calcium carbonate. your plan should include how you will use your results to determine which one  of the two lumps has the larger percentage of calcium carbonate.   you have access to all common laboratory materials and a supply of dilute hydrochloric acid.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/52/f/m/21 \u00a9 ucles 2021blank page",
            "9": "9 0620/52/f/m/21 \u00a9 ucles 2021blank page",
            "10": "10 0620/52/f/m/21 \u00a9 ucles 2021blank page",
            "11": "11 0620/52/f/m/21 \u00a9 ucles 2021notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/52/f/m/21 \u00a9 ucles 2021tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_m21_qp_62.pdf": {
            "1": "*1587780154* chemistry  0620/62 paper 6 alternative to practical february/march 2021  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib21 03_0620_62/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/62/f/m/21 \u00a9 ucles 2021 1  silver chloride is an ionic compound and is insoluble in water. molten silver chloride breaks down  during electrolysis. the products are chlorine and silver.   chlorine gas is soluble in water and toxic.   a student suggests using the apparatus shown to break down silver chloride. power supply silver chloride  (a)  draw an arrow on the diagram to show where heat must be applied so that the silver chloride  can break down. [1]  (b)  complete the diagram to show how chlorine gas can be collected and the volume of the  chlorine measured. label any apparatus you have drawn. [2]  (c)  give two observations that are made as the silver chloride breaks down.  1  .  2  .  [2]",
            "3": "3 0620/62/f/m/21 \u00a9 ucles 2021 [turn over  (d)  the person doing the experiment followed all normal laboratory safety rules.   state one additional safety precaution that should be taken when doing this experiment. give  a reason for your answer.  safety precaution  ...  reason    [2]  (e)  suggest one reason why zinc is not a suitable material to use as the electrodes.      ..   [1]  (f)  the chlorine gas was bubbled into an aqueous solution of a sodium salt. the colour of the  solution changed from colourless to orange.   identify the sodium salt and explain what has happened to cause the colour change.  sodium salt    explanation  .     [2]  [total: 10]",
            "4": "4 0620/62/f/m/21 \u00a9 ucles 2021 2\t\ta\tstudent\t investigated \tthe\treaction\t between\t aqueous\t potassium\t hydroxide\t and\ttwo\tdifferent\t aqueous solutions of hydrochloric acid labelled solution a and solution b.   two experiments were done.  (a)  experiment 1  \u25cf a burette was filled with solution a. some of solution  a was run out of the burette so that  the level of solution a was on the burette scale.  \u25cf a measuring cylinder was used to measure 25 cm3 of the aqueous potassium hydroxide.  \u25cf the aqueous potassium hydroxide was poured into a conical flask.  \u25cf five drops of methyl orange indicator were added to the conical flask.  \u25cf solution a was added slowly from the burette to the conical flask, while the flask was  swirled, until the solution just changed colour.   use the burette diagrams to complete the table for experiment 1. 7 8 9 initial reading16 17 18 final reading experiment 1 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of solution a\tadded\t /\tcm3   experiment 2  \u25cf the conical flask was emptied and rinsed with distilled water.  \u25cf the burette was emptied and rinsed with distilled water.  \u25cf the burette was rinsed with solution b.  \u25cf the burette was filled with solution b. some of solution b was run out of the burette so that  the level of solution b was on the burette scale.  \u25cf a measuring cylinder was used to measure 25 cm3 of the aqueous potassium hydroxide.  \u25cf the aqueous potassium hydroxide was poured into the conical flask.  \u25cf five drops of methyl orange indicator were added to the conical flask.  \u25cf solution b was added slowly from the burette to the conical flask, while the flask was  swirled, until the solution just changed colour.",
            "5": "5 0620/62/f/m/21 \u00a9 ucles 2021 [turn over   use the burette diagrams to complete the table for experiment 2. 7 8 9 initial reading26 27 28 final reading experiment 2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of solution b\tadded\t /\tcm3  [4]  (b)\t\tstate\tthe\tcolour\tchange\tobserved\tin\tthe\tconical\tflask\tat\tthe\tend-point\tin\texperiment\t2.   from  to     [1]  (c)\t\tbefore\tstarting\tthe\ttitration\tin\texperiment\t2\tthe\tconical\tflask\twas\trinsed\twith\twater.  (i)\t\texplain\twhy\tthe\tconical\tflask\twas\trinsed \twith\twater.   ...   [1]  (ii)\t\tthe\tconical\tflask\twas\tnot then rinsed with aqueous potassium hydroxide. \t \tstate\thow\trinsing\tthe\tconical\tflask\twith\taqueous\t potassium\t hydroxide\t would\tchange\tthe\t volume of solution b needed. explain your answer.   .   ...   [2]  (d) (i)  deduce which aqueous solution of hydrochloric acid, a or b, was more concentrated.  explain your answer.   .   ...   [1]  (ii)  deduce how many times more concentrated this solution of hydrochloric acid was than the  other solution of hydrochloric acid.   ...   [1]",
            "6": "6 0620/62/f/m/21 \u00a9 ucles 2021  (e)  explain why experiment 1 and experiment 2 should be repeated.      ..   [1]  (f)  deduce the volume of solution b required if experiment 2 is carried out with 50 cm3 of aqueous  potassium hydroxide.      ..   [2]  (g)  describe one change that could be made to the apparatus to improve the accuracy of the  results.      ..   [1]  (h)\t\tdescribe\twhat\teffect\tusing\ta\tlarger\tconical\tflask\twould\thave\ton\tthe\tresults\tobtained.   ..   [1]  [total: 15]",
            "7": "7 0620/62/f/m/21 \u00a9 ucles 2021 [turn over 3  two solids, solid c and solid d, were analysed.   tests were done on each solid.   tests on solid c   tests were carried out and the following observations were made. tests observations test 1 a\tflame\ttest\twas\tcarried\tout\ton\tsolid\t c. a\tred\tflame\twas\tseen solid c was dissolved in distilled water to  produce solution c. test 2 about 5 cm3 of aqueous sodium hydroxide was  added to solution c.no change test 3 a piece of aluminium foil was added to the  mixture formed in test 2.the mixture was  warmed gently and any gas produced was  tested.effervescence\twas\tseen; damp red litmus paper turned blue  (a)  name the gas that turned the damp red litmus paper blue in test 3.   ..   [1]  (b)  identify solid c.      ..   [2]",
            "8": "8 0620/62/f/m/21 \u00a9 ucles 2021  tests on solid d   solid d was aluminium sulfate.   complete the expected observations.   solid d was dissolved in water to form solution d. solution d was divided into four approximately  equal\tportions\tin\tfour\ttest-tubes.  (c)\t\taqueous\t sodium\thydroxide\t was\tadded\tdropwise\t and\tthen\tin\texcess\tto\tthe\tfirst\tportion\tof\t solution d.  observations  ..   ..   [2]  (d)  aqueous ammonia was added dropwise and then in excess to the second portion of solution d.  observations  ..   ..   [2]  (e)  about 1 cm3 of dilute nitric acid and a few drops of aqueous silver nitrate were added to the  third portion of solution d.  observations     [1]  (f)  about 1 cm3 of dilute nitric acid and a few drops of aqueous barium nitrate were added to the  fourth portion of solution d.  observations     [1]  [total: 9]",
            "9": "9 0620/62/f/m/21 \u00a9 ucles 2021 [turn over 4  old concrete contains calcium carbonate. calcium carbonate reacts with dilute hydrochloric acid. caco3(s)  +  2hcl (aq)  \u2192  cacl 2(aq)  +  h2o(l)  +  co2(g) \t\tplan\tan\tinvestigation\t to\tfind\twhich\tof\ttwo\tlumps\tof\tconcrete\t contains\t the\tlarger\tpercentage\t of\t calcium carbonate. your plan should include how you will use your results to determine which one  of the two lumps has the larger percentage of calcium carbonate.   you have access to all common laboratory materials and a supply of dilute hydrochloric acid.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "10": "10 0620/62/f/m/21 \u00a9 ucles 2021blank page",
            "11": "11 0620/62/f/m/21 \u00a9 ucles 2021blank page",
            "12": "12 0620/62/f/m/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s21_qp_11.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 06_0620_11/2rp   \u00a9 ucles 2021   [turn ove r   *8872248645 *cambridge igcse\u2122       chemistry 0620/11     paper 1 multiple choice (core)  may/june 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/11/m/j/21  1 which row describes the arrangement and movement of particles i n a liquid?     arrangement of particles movement of particles  a touching and regular vibrating  b touching and random moving around each other  c touching and regular moving around each other  d touching and random moving very fast      2 a mixture is separated using the apparatus shown.    mixture funnel filter pape r     what is the mixture?  a aqueous copper( ii) sulfate and aqueous sodium chloride  b aqueous copper( ii) sulfate and copper  c copper and sulfur  d ethanol and ethanoic acid    3 which statement about paper chromatography is correct?  a a solvent is needed to dissolve the paper.  b paper chromatography separates mixtures of solvents.  c the solvent should cover the baseline.  d the baseline should be drawn in pencil.    ",
            "3": "3     \u00a9 ucles 2021 0620/11/m/j/21 [turn over  4 element x has 7 protons.    element y has 8 more protons than x.    which statement about element y is correct?  a y has more electron shells than x.  b y has more electrons in its outer shell than x.  c y is in a different group of the periodic table from x.  d y is in the same period of the periodic table as x.     5 a covalent molecule q contains only six shared electrons.    what is q?  a ammonia, nh 3  b chlorine, c l 2  c methane, ch 4  d water, h 2o    6 which row describes how an ionic bond forms between a sodium at om and a chlorine atom?     sodium atom chlorine atom  a two electrons are lost two electrons are gained  b one electron is gained one electron is lost  c two electrons are gained two electrons are lost  d one electron is lost one electron is gained     7 which diagram shows the structure of an alloy?    abcd      ",
            "4": "4  \u00a9 ucles 2021 0620/11/m/j/21  8 methane burns in oxygen to produce carbon dioxide and water.    what is the balanced equation for this reaction?  a c h 4  +  2o 2  \uf0ae  2co 2  +  2h 2o  b c h 4  +  2o 2  \uf0ae  co 2  +  2h 2o  c c h 4  +  2o 2  \uf0ae  co 2  +  h 2o  d c h 4  +  o 2  \uf0ae  co 2  +  2h 2o      9 what is the relative formula mass of magnesium nitrate, mg(no 3)2?  a 74 b 86 c 134 d 148    10 in separate experiments, electricity was passed through concen trated aqueous sodium chloride  and molten lead( ii) bromide.    what would happen in both  experiments?  a a halogen would be formed at the anode.  b a metal would be formed at the cathode.  c hydrogen would be formed at the anode.  d hydrogen would be formed at the cathode.      11 steel core aluminium cables are used for overhead electricity c ables.    which statement explains why these cables are used?  a aluminium conducts electricity only when it surrounds a steel core.  b aluminium conducts electricity and the steel core makes the ca ble stronger.  c steel conducts electricity and is surrounded by aluminium beca use aluminium is an insulator.  d steel conducts electricity and is surrounded by aluminium to s top the steel from corroding.    ",
            "5": "5     \u00a9 ucles 2021 0620/11/m/j/21 [turn over  12 the complete combustion of propane is exothermic.    the equation for this reaction is shown.    c3h8  +  5o 2  \uf0ae  3co 2  +  4h 2o    which energy level diagram represents the complete combustion o f propane?    energy progress of reactiona 3co2 + 4h2oc3h8 + 5o2 energy progress of reactionb c3h8 + 5o23co2 + 4h2o energy progress of reactionc 3co2 + 4h2o c3h8 + 5o2energy progress of reactiond c3h8 + 5o2 3co2 + 4h2o      13 which changes occur when hydrogen is burned in oxygen?     energy change product  a endothermic h 2o only  b endothermic h 2o and co 2  c exothermic h 2o only  d exothermic h 2o and co 2     ",
            "6": "6  \u00a9 ucles 2021 0620/11/m/j/21  14 when sulfur is heated it undergoes a ..1.. change as it  melts.    further heating causes the sulfur to undergo a ..2.. ch ange and form sulfur dioxide.    which words complete gaps 1 and 2?     1  2   a chemical chemical  b chemical physical  c physical chemical  d physical physical     15 zinc reacts with an acid to form a gas. the volume of gas produ ced is measured at intervals. the  results are shown as curve z.    the reaction is repeated in the presence of a catalyst.    which curve shows the results  for the catalysed reaction?    volume of gas formed timea cz db       16 which statement is correct?  a when anhydrous copper( ii) sulfate is heated its colour changes to a deeper blue.  b when hydrated copper( ii) sulfate is heated its colour changes to a deeper blue.  c when water is added to blue cobalt( ii) chloride paper it turns pink.  d when water is added to pink cobalt( ii) chloride paper it turns blue.     ",
            "7": "7     \u00a9 ucles 2021 0620/11/m/j/21 [turn over  17 three separate experiments are carried out on an aqueous soluti on of s.    the results are shown.    1 magnesium does not react with the solution.  2 a gas is given off when ammonium sulfate is heated with the s olution.  3 methyl orange turns yellow when added to the solution.    what is s?  a hydrochloric acid  b sodium hydroxide  c sodium chloride  d sulfur dioxide    18 element x forms an oxide, xo, that neutralises sulfuric acid.    which row describes x and xo?     element x nature of oxide, xo  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic      19 copper( ii) sulfate is prepared by adding excess copper( ii) oxide to warm dilute sulfuric acid.    which purification methods are used to obtain pure solid copper (ii) sulfate from the reaction  mixture?    1 crystallisation  2 filtration  3 chromatography  4 distillation    a 1 and 4 b 1 and 2 c 2 and 3 d 3 and 4    ",
            "8": "8  \u00a9 ucles 2021 0620/11/m/j/21  20 some reactions of element m are shown.    element m oxide of m solution add blue litmusadd to purple acidified potassium manganate( vii) goes redburn add water goes colourless     what is element m?  a carbon  b iron  c magnesium  d sulfur     21 element x is in group ii of the periodic table.    which statements about x are correct?    1 x is a metal.  2 x has two electrons in its outer shell. 3 x is a liquid at room temperature.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3      22 why is helium used to fill balloons?  a helium is monoatomic.  b helium is in group viii of the periodic table.  c helium has a full outer electron shell.  d helium is less dense than air.     ",
            "9": "9     \u00a9 ucles 2021 0620/11/m/j/21 [turn over  23 which row describes the trend in properties of the elements in group i as the group is  descended?     melting  point reactivity  with water  a decreases decreases  b decreases increases  c increases decreases  d increases increases      24 an element melts at 1455  \uf0b0c, has a density of 8.90  g / cm3 and forms a green chloride.    where in the periodic tabl e is this element found?    cb da      25 some properties of metal j are listed.    \u25cf j does not react with cold water.  \u25cf j reacts with dilute hydrochloric acid. \u25cf no reaction occurs when the oxide of j is heated with carbon.     what is j?  a copper  b iron  c magnesium  d s o d i u m     ",
            "10": "10  \u00a9 ucles 2021 0620/11/m/j/21  26 iron from a blast furnace is treated with oxygen and with calc ium oxide to make steel.    which substances in the iron are removed?     oxygen  removes calcium oxide  removes  a carbon acidic oxides  b carbon basic oxides  c iron acidic oxides  d iron basic oxides     27 which row describes a use of the metal and explains why it is u sed?     metal use reason  a aluminium food containers good conductor of electricity  b aluminium aircraft wings high density  c copper cooking utensils good conductor of heat  d copper electricity cables good electrical insulator     28 ammonium chloride is heated with aqueous sodium hydroxide.    ammonium chloride and aqueous sodium hydroxidedamp universal indicator paper gentle heat    a gas is produced which turns damp universal indicator paper bl ue.    which gas has been produced?  a ammonia  b hydrogen  c oxygen  d sulfur dioxide    ",
            "11": "11     \u00a9 ucles 2021 0620/11/m/j/21 [turn over  29 which two gases make up approximately 99% of clean, dry air?  a carbon dioxide and nitrogen  b carbon dioxide and oxygen  c nitrogen and oxygen  d argon and  nitrogen      30 a student writes three statements about potassium nitrate, kno 3.    1 the relative formula mass of kno 3 is 101.  2 potassium nitrate contains the three essential elements for p lant growth.  3 potassium nitrate could be used as a fertiliser.    which statements are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    31 which row describes the uses of sulfur and sulfur dioxide?     sulfur sulfur dioxide  a extraction of aluminium food preservative  b extraction of aluminium manufacture of cement  c manufacture of sulfuric acid food preservative  d manufacture of sulfuric acid manufacture of cement     32 a white solid z reacts with dilute hydrochloric acid to produce  a gas.    the same gas is produced when compound z is heated strongly.    what is z?  a calcium  b calcium carbonate  c calcium hydroxide  d calcium oxide     ",
            "12": "12  \u00a9 ucles 2021 0620/11/m/j/21  33 some information about compound l is listed.    1 l is an organic compound which contains four hydrogen atoms.  2 l is soluble in water.  3 an aqueous solution of l reacts with copper( ii) carbonate to produce a gas.    what is l?  a methane  b ethene  c ethanoic acid  d ethanol      34 the structure of an organic molecule is shown.    ch ho o hh ch ch ch hco     which functional groups does this molecule contain?     alcohol alkene carboxylic  acid  a no no no  b no yes yes  c yes no yes  d yes yes yes      35 which compounds belong to the same homologous series?  a ethane and propane  b ethanoic acid and ethanol  c methane and ethene  d propene and ethanoic acid    ",
            "13": "13     \u00a9 ucles 2021 0620/11/m/j/21  36 which statement about alkanes is correct?  a they burn in oxygen.  b they contain carbon, hydrogen and oxygen atoms.  c they contain double bonds.  d they contain ionic bonds.      37 which structure represents poly(ethene)?    c hh c hhac hh c hhb nnc hh c hhc nc hh c hhd      38 p, q, r and s are four organic compounds.    p is an unsaturated hydrocarbon.    q burns but otherwise is unreactive.    r contains a c\u2013c single bond and a c=c double bond.    s undergoes addition polymerisation.    which compounds are alkenes?  a p and r only b p, r and s c p, q and s d q, r and s     39 which statement about petroleum fractions is correct?  a all petroleum fractions are used as fuels.  b gas oil is used to make bottled gas for heating.  c hydrocarbons in diesel have higher boiling points than hydrocar bons in gasoline.  d molecules in kerosene are larger than molecules in fuel oil.     40 which substance is a natural polymer?  a ethene  b terylene   c nylon  d protein   ",
            "14": "14  \u00a9 ucles 2021 0620/11/m/j/21  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/11/m/j/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/11/m/j/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s21_qp_13.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 06_0620_13/2rp   \u00a9 ucles 2021   [turn ove r   *4106947783*cambridge igcse\u2122       chemistry 0620/13     paper 1 multiple choice (core)  may/june 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/13/m/j/21  1 a  1  cm3 sample of substance x is taken. this is sample 1.    x is then converted to a different physical state and a 1  cm3 sample is taken. this is sample 2.    sample 2 contains more particles in the 1  cm3 than sample 1.    which process caused this increase in the number of particles i n 1  cm3?  a boiling of liquid x  b condensation of gaseous x  c evaporation of liquid x  d sublimation of solid x     2 solid carbon dioxide changes directly into a gas under suitable  conditions of temperature and  pressure.    carbon dioxide gas moves from a high concentration to a low con centration.    which row names these two processes?     changing from  solid to gas moving from a  high concentration to  a low concentration  a evaporation brownian motion  b evaporation diffusion  c sublimation brownian motion  d sublimation diffusion      3 which statement about paper chromatography is correct?  a a solvent is needed to dissolve the paper.  b paper chromatography separates mixtures of solvents.  c the solvent should cover the baseline.  d the baseline should be drawn in pencil.    ",
            "3": "3     \u00a9 ucles 2021 0620/13/m/j/21 [turn over  4 element x has 7 protons.    element y has 8 more protons than x.    which statement about element y is correct?  a y has more electron shells than x.  b y has more electrons in its outer shell than x.  c y is in a different group of the periodic table from x.  d y is in the same period of the periodic table as x.     5 a covalent molecule q contains only six shared electrons.    what is q?  a ammonia, nh 3  b chlorine, c l 2  c methane, ch 4  d water, h 2o     6 which piece of apparatus is used to measure exactly 25.00  cm3 of hydrochloric acid?  a beaker  b measuring cylinder  c pipette  d balance     7 which statement about isotopes of the same element is correct?  a they have different numbers of electrons.  b they have different numbers of neutrons.  c they have different numbers of protons.  d they have the same mass number.    ",
            "4": "4  \u00a9 ucles 2021 0620/13/m/j/21  8 potassium reacts with iodine to form an ionic compound.    2k  +  i2  \uf0ae  2k i    which statements describe what happens when potassium reacts wi th iodine?    1 each potassium atom loses two electrons.  2 each potassium atom loses one electron.  3 each iodine atom gains one electron.  4 each iodine atom gains two electrons.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    9 what is the relative formula mass of magnesium nitrate, mg(no 3)2?  a 74 b 86 c 134 d 148     10 in separate experiments, electricity was passed through concen trated aqueous sodium chloride  and molten lead( ii) bromide.    what would happen in both  experiments?  a a halogen would be formed at the anode.  b a metal would be formed at the cathode.  c hydrogen would be formed at the anode.  d hydrogen would be formed at the cathode.    11 the equation for the decomposition of calcium carbonate is show n.    caco 3  \uf0ae  cao  +  co 2    what mass of calcium oxide is produced when 10  g of calcium carbonate is heated?  a 4 . 4  g b 5 . 0  g c 5 . 6  g d 10.0  g     ",
            "5": "5     \u00a9 ucles 2021 0620/13/m/j/21 [turn over  12 heat energy transfer during chem ical reactions can be described  using energy level diagrams.    in which row is the description correct?     energy level diagram description  1  progress of reactionenergy  exothermic  2  progress of reactionenergy  heat energy absorbed  from environment  3  progress of reactionenergy  heat energy released  to environment  4  progress of reactionenergy  endothermic    a 1 and 2 b 1 and 3 only c 1, 3 and 4 d 2 and 4    ",
            "6": "6  \u00a9 ucles 2021 0620/13/m/j/21  13 the equations for two reactions are shown.    1 ch 4  +  2o 2  \uf0ae  co 2  +  2h 2o  2 2h 2  +  o 2  \uf0ae  2h 2o    which statement about the reactions is correct?  a heat energy is released during both these reactions.  b heat energy is absorbed during both these reactions.  c heat energy is released during reaction 1 but absorbed during reaction 2.  d heat energy is released during reaction 2 but absorbed during reaction 1.    14 when sulfur is heated it undergoes a ..1.. change as it  melts.    further heating causes the sulfur to undergo a ..2.. ch ange and form sulfur dioxide.    which words complete gaps 1 and 2?     1  2   a chemical chemical  b chemical physical  c physical chemical  d physical physical      15 copper( ii) carbonate reacts with dilute sulfuric acid.    which conditions produce the fastest rate of reaction?     form of  copper( ii) carbonate temperature of dilute  sulfuric acid  / \uf0b0c  a large lumps 37  b large lumps 70  c powder 37  d powder 70     ",
            "7": "7     \u00a9 ucles 2021 0620/13/m/j/21 [turn over  16 hydrated copper( ii) sulfate is blue. when it is heated it forms white anhydrous c opper( ii) sulfate.    how is a sample of anhydrous copper( ii) sulfate changed into hydrated copper( ii) sulfate?  a water is added.  b it is cooled down.  c it is heated up.  d water is removed.      17 copper( ii) oxide reacts with iron. the equation for the reaction is show n.    3cuo  +  2fe  \uf0ae  3cu  +  fe 2o3    why can this reaction be described as the reduction of copper( ii) oxide?  a iron gains oxygen.  b the copper( ii) oxide loses oxygen.  c the copper( ii) oxide weighs less after the reaction than before.  d there are fewer substances on the right of the equation.    18 element x forms an oxide, xo, that neutralises sulfuric acid.    which row describes x and xo?     element x nature of oxide, xo  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic      19 which methods of salt preparation are suitable for copper( ii) chloride?    1 add copper( ii) carbonate to dilute hydrochloric acid.  2 add copper to dilute hydrochloric acid.  3 warm copper( ii) oxide with dilute hydrochloric acid.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only    ",
            "8": "8  \u00a9 ucles 2021 0620/13/m/j/21  20 a white solid, j, is tested and the observations are shown.    test observations  flame test red flame  acidify with nitric acid then  add aqueous silver nitrate white precipitate      what is j?  a lithium bromide  b lithium chloride  c sodium bromide  d sodium chloride      21 which statement about the periodic table is not correct?  a elements in the same period have similar properties.  b it can be used to predict the properties of elements.  c non-metals are found on the right side of the table.  d there are more metals than non-metals.      22 bromine and iodine are elements in group vii of the periodic ta ble.    which statement about these elements is correct?  a iodine displaces bromide ions from solution.  b bromine is a lighter colour than iodine.  c bromine is more dense than iodine.  d bromine is less reactive than iodine.    23 helium and neon exist as monoatomic gases at room temperature and pressure.    statement 1 helium and neon have eight electrons in their outer  shell.  statement 2 helium and neon are unreactive.    which option is correct?  a statement 1 and statement 2 are incorrect.  b statement 1 is correct and explains statement 2.  c statement 1 is correct, but does not explain statement 2.  d statement 1 is incorrect, but statement 2 is correct.   ",
            "9": "9     \u00a9 ucles 2021 0620/13/m/j/21 [turn over  24 an element melts at 1455  \uf0b0c, has a density of 8.90  g / cm3 and forms a green chloride.    where in the periodic tabl e is this element found?    cb da       25 which statement about the reactivity of metals is correct?  a iron is more reactive than magnesium.  b copper reacts with dilute hydrochloric acid.  c potassium reacts with cold water.  d calcium oxide is reduced more easily than iron oxide.    26 iron from a blast furnace is treated with oxygen and with calc ium oxide to make steel.    which substances in the iron are removed?     oxygen  removes calcium oxide  removes  a carbon acidic oxides  b carbon basic oxides  c iron acidic oxides  d iron basic oxides      27 water is removed from reservoirs and undergoes several stages o f treatment to make it suitable  for drinking.    which statements about the stages are correct?    1 chlorine is added to the water to kill harmful bacteria.  2 water is heated to remove dissolved oxygen gas.  3 water is filtered to remove solids.    a 1 only b 1 and 2 c 1 and 3 d 2 and 3     ",
            "10": "10  \u00a9 ucles 2021 0620/13/m/j/21  28 which gas is an air pollutant that causes acid rain?  a argon  b carbon monoxide  c methane  d nitrogen dioxide      29 an npk fertiliser is made by mixing two compounds.    the first compound has the formula (nh 4)2hpo 4.    what is the formula of the second compound?  a c a c o 3 b k n o 3 c n a c l d ( n h 4)2so 4     30 which reaction does not occur during the extraction of iron from hematite in a blast f urnace?  a c  +  o 2  \uf0ae  co 2  b cao  +  sio 2  \uf0ae  casio 3  c c o 2  +  c  \uf0ae  2co  d 4fe  +  3o 2  \uf0ae  2fe 2o3    31 which row describes the uses of sulfur and sulfur dioxide?     sulfur sulfur dioxide  a extraction of aluminium food preservative  b extraction of aluminium manufacture of cement  c manufacture of sulfuric acid food preservative  d manufacture of sulfuric acid manufacture of cement     ",
            "11": "11     \u00a9 ucles 2021 0620/13/m/j/21 [turn over  32 metal x is a good conductor of electricity and is used for elec trical wiring.    metal y is used to make an alloy which is resistant to corrosio n and is used to make cutlery.    metal z is light and strong and is used in the manufacture of a ircraft.    what are x, y and z?     x  y  z   a aluminium iron copper  b copper iron aluminium  c aluminium copper iron  d copper aluminium iron      33 which statement about calcium carbonate is correct?  a it is made by the thermal decomposition of limestone.  b it is used to neutralise alkaline soils.  c it is a reactant in the test for carbon dioxide.  d it is used to remove impurities in iron extraction.      34 what is the main constituent of natural gas?  a hydrogen  b methane  c nitrogen  d oxygen      35 which compounds belong to the same homologous series?  a ethane and propane  b ethanoic acid and ethanol  c methane and ethene  d propene and ethanoic acid      36 which statement about alkanes is correct?  a they burn in oxygen.  b they contain carbon, hydrogen and oxygen atoms.  c they contain double bonds.  d they contain ionic bonds. ",
            "12": "12  \u00a9 ucles 2021 0620/13/m/j/21  37 p, q, r and s are organic compounds.    p is formed by reacting ethene with steam.    q decolourises bromine water.    r is a hydrocarbon; all of its bonds are single covalent bonds.     s is a waste product from digestion in animals.    which compounds are alkanes?  a p and q b p and s c q and r d r and s    38 which row describes how ethanol is used?     fuel solvent  a no no  b no yes  c yes no  d yes yes     39 which diagram shows the conversion of ethene into ethanol?    a cch h hh cc h hhh hhb cch h hh cc o h hhh hh c cch h hh cc h hhh hhd cc h hh h hh cc o h hhh hh       40 which substance is a natural polymer?  a ethene  b terylene   c nylon  d protein ",
            "13": "13     \u00a9 ucles 2021 0620/13/m/j/21  blank page",
            "14": "14  \u00a9 ucles 2021 0620/13/m/j/21  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/13/m/j/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/13/m/j/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s21_qp_21.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 06_0620_21/2rp   \u00a9 ucles 2021   [turn ove r   *6593451513 *cambridge igcse\u2122       chemistry 0620/21     paper 2 multiple choice (extended)  may/june 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/21/m/j/21  1 a gas is released at point p in the apparatus shown.    p damp universal indicator pape r    which gas turns the damp universal indicator paper red most qui ckly?  a ammonia, nh 3  b chlorine, c l 2  c hydrogen chloride, hc l  d sulfur dioxide, so 2    2 a mixture is separated using the apparatus shown.    mixture funnel filter pape r     what is the mixture?  a aqueous copper( ii) sulfate and aqueous sodium chloride  b aqueous copper( ii) sulfate and copper  c copper and sulfur  d ethanol and ethanoic acid      3 which statement about paper chromatography is correct?  a a solvent is needed to dissolve the paper.  b paper chromatography separates mixtures of solvents.  c the solvent should cover the baseline.  d the baseline should be drawn in pencil.     ",
            "3": "3     \u00a9 ucles 2021 0620/21/m/j/21 [turn over  4 element x has 7 protons.    element y has 8 more protons than x.    which statement about element y is correct?  a y has more electron shells than x.  b y has more electrons in its outer shell than x.  c y is in a different group of the periodic table from x.  d y is in the same period of the periodic table as x.     5 a covalent molecule q contains only six shared electrons.    what is q?  a ammonia, nh 3  b chlorine, c l 2  c methane, ch 4  d water, h 2o    6 the arrangement of particles in each of two solids, s and t, a re shown.    st    what are s and t?     s  t   a diamond silicon( iv) oxide  b diamond sodium chloride  c graphite silicon( iv) oxide  d graphite sodium chloride     ",
            "4": "4  \u00a9 ucles 2021 0620/21/m/j/21  7 which statement about metals is correct?  a metals conduct electricity when molten because negative ions a re free to move.  b metals conduct electricity when solid because positive ions ar e free to move.  c metals are malleable because the bonds between the atoms are w eak.  d metals are malleable because the layers of ions can slide over  each other.      8 two elements, p and q, are in the same period of the periodic t able.    p and q react together to form an ionic compound. part of the l attice of this compound is shown.    q\u2013 p+p+ q\u2013p+ q\u2013q\u2013 p+     which statement is correct?  a an ion of p has more electrons than an ion of q.  b element p is non-metallic.  c p is to the left of q in the periodic table.  d the formula of the compound is p 4q4.    9 2.56  g of a metal oxide, mo 2, is reduced to 1.92  g of the metal, m.    what is the relative atomic mass of m?  a 48 b 9 6  c 128 d 192    10 in separate experiments, electricity was passed through concen trated aqueous sodium chloride  and molten lead( ii) bromide.    what would happen in both  experiments?  a a halogen would be formed at the anode.  b a metal would be formed at the cathode.  c hydrogen would be formed at the anode.  d hydrogen would be formed at the cathode.    ",
            "5": "5     \u00a9 ucles 2021 0620/21/m/j/21 [turn over  11 what is the ionic half-equation for the reaction that occurs at  the cathode when molten  lead( ii) bromide is electrolysed?  a p b2+  +  2e\u2013  \uf0ae  pb  b 2 b r  \u2013  \uf0ae  br 2  +  2e\u2013  c b r 2  +  2e\u2013  \uf0ae  2br  \u2013  d p b   \uf0ae  pb2+  +  2e\u2013     12 the complete combustion of propane is exothermic.    the equation for this reaction is shown.    c 3h8  +  5o 2  \uf0ae  3co 2  +  4h 2o    which energy level diagram represents the complete combustion o f propane?    energy progress of reactiona 3co2 + 4h2oc3h8 + 5o2 energy progress of reactionb c3h8 + 5o23co2 + 4h2o energy progress of reactionc 3co2 + 4h2o c3h8 + 5o2energy progress of reactiond c3h8 + 5o2 3co2 + 4h2o      ",
            "6": "6  \u00a9 ucles 2021 0620/21/m/j/21  13 which equation represents a reaction that takes place in a fuel  cell?  a c  +  o 2  \uf0ae  co 2  b 2h2  +  o 2  \uf0ae  2h 2o  c ch 4  +  2o 2  \uf0ae  co 2  +  2h 2o  d c3h8  +  5o 2  \uf0ae  3co 2  +  4h 2o     14 when sulfur is heated it undergoes a ..1.. change as it  melts.    further heating causes the sulfur to undergo a ..2.. ch ange and form sulfur dioxide.    which words complete gaps 1 and 2?     1  2   a chemical chemical  b chemical physical  c physical chemical  d physical physical     15 four statements about the effect of increasing temperature on a reaction are shown.    1 the activation energy becomes lower.  2 the particles move faster. 3 there are more collisions betw een reacting particles per seco nd.  4 there are more collisions which have energy greater than the activation energy.    which statements are correct?  a 1, 2 and 3 b 1, 3 and 4 c 2, 3 and 4 d 2 and 3 only     ",
            "7": "7     \u00a9 ucles 2021 0620/21/m/j/21 [turn over  16 an example of a redox reaction is shown.    zn  +  cu2+  \uf0ae  zn2+  +  cu    which statement about the reaction is correct?  a zn is the oxidising agent and it oxidises cu2+.  b zn is the oxidising agent and it reduces cu2+.  c zn is the reducing agent and it oxidises cu2+.  d zn is the reducing agent and it reduces cu2+.      17 which statement about a reaction in equilibrium is correct?  a both the forward and the backward reactions are proceeding at the same rate.  b neither the forward nor the backward reaction is proceeding.  c the amount of product present is no longer affected by changes  in temperature or pressure.  d the amount of product present is only affected by a change in pressure.      18 element x forms an oxide, xo, that neutralises sulfuric acid.    which row describes x and xo?     element x nature of oxide, xo  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic      19 copper( ii) sulfate is prepared by adding excess copper( ii) oxide to warm dilute sulfuric acid.    which purification methods are used to obtain pure solid copper (ii) sulfate from the reaction  mixture?    1 crystallisation  2 filtration 3 chromatography 4 distillation    a 1 and 4 b 1 and 2 c 2 and 3 d 3 and 4     ",
            "8": "8  \u00a9 ucles 2021 0620/21/m/j/21  20 some reactions of element m are shown.    element m oxide of m solution add blue litmusadd to purple acidified potassium manganate( vii) goes redburn add water goes colourless     what is element m?  a carbon  b iron  c magnesium  d sulfur      21 in which equation is the underlined reactant acting as a base?  a c h 3coo\u2013  +  h 3o+  \uf0ae  ch 3cooh  +  h 2o  b n h 4+  +  oh\u2013  \uf0ae  nh 3  +  h 2o  c c o 2  +  2h 2o  \uf0ae  h3o+  +  hco 3\u2013  d h+  +  oh\u2013  \uf0ae  h2o      22 why is helium used to fill balloons?  a helium is monoatomic.  b helium is in group viii of the periodic table.  c helium has a full outer electron shell.  d helium is less dense than air.      23 which elements in the table are transition elements?    element property  e forms e3+ ions only  f forms f+ and f2+ ions  g forms only white salts  h used in catalytic converters    a e and g b e and h c f and g d f and h ",
            "9": "9     \u00a9 ucles 2021 0620/21/m/j/21 [turn over  24 element r forms a covalent compound r 2si with silicon.    which row describes r?     metallic or  non-metallic character group number in  the periodic table  a metallic ii  b metallic vi  c non-metallic ii  d non-metallic vi     25 some properties of metal j are listed.    \u25cf j does not react with cold water.  \u25cf j reacts with dilute hydrochloric acid. \u25cf no reaction occurs when the oxide of j is heated with carbon.     what is j?  a copper  b iron  c magnesium  d s o d i u m     26 some metal nitrates and carbonates decompose when heated strong ly.    metal q has a nitrate that decomposes to give a salt and a colo urless gas only.    the carbonate of metal q does not decompose when heated with a bunsen burner.    what is metal q?  a calcium  b copper  c s o d i u m   d z i n c     ",
            "10": "10  \u00a9 ucles 2021 0620/21/m/j/21  27 which substances are used in the extraction of aluminium?  a bauxite and cryolite  b bauxite and hematite  c cryolite and zinc blende  d hematite and zinc blende      28 different types of steel alloys are manufactured by changing th e percentage of carbon in the  alloy.    the properties of four steel alloys are shown.    alloy  mixture percentage of  carbon in the alloy strength of  the alloy hardness of  the alloy  1 0.00 to 0.20 high low  2 0.21 to 0.30 high medium  3 0.31 to 0.40 medium high  4 0.41 to 1.50 low high    what are the properties of the steel alloy containing 0.23% of carbon?     strength hardness  a high low  b low high  c high medium  d medium high     29 ammonia is made by reacting nitrogen with hydrogen in the habe r process.    the equation for the process is shown.    n 2  +  3h 2    2nh 3    which changes in reaction conditions would produce a greater yi eld of ammonia?    1 adding more iron catalyst  2 increasing the reaction pressure 3 increasing the particle size of the iron catalyst    a 1 only b 2  o n l y  c 1 and 2 d 2 and 3     ",
            "11": "11     \u00a9 ucles 2021 0620/21/m/j/21 [turn over  30 which process removes carbon dioxide from the atmosphere?  a combustion of fossil fuels  b fermentation  c photosynthesis  d respiration      31 which catalyst is used in the contact process?  a calcium oxide  b iron  c manganese( ii) oxide  d vanadium( v) oxide     32 a white solid z reacts with dilute hydrochloric acid to produce  a gas.    the same gas is produced when compound z is heated strongly.    what is z?  a calcium  b calcium carbonate  c calcium hydroxide  d calcium oxide     33 what is the structure of butanoic acid?  a c h 3ch 2co 2h  b c h 3ch 2ch 2co 2h  c c h 3ch 2ch 2ch 2co 2h  d c h 3ch 2ch 2co 2ch 3    ",
            "12": "12  \u00a9 ucles 2021 0620/21/m/j/21  34 compound z contains carbon, hydrogen and oxygen.    molecules of compound z have four hydrogen atoms and two carbon  atoms.    compound z can be made by oxidation of an alcohol.    what is compound z?  a ethene  b ethanol  c ethanoic acid  d methyl methanoate      35 which statement about homologous series and isomerism is corre ct?  a butane and butene are structural isomers.  b compounds in the same homologous series have the same general formula.  c compounds in the same homologous series have the same molecula r formula.  d structural isomers have different molecular formulae.      36 which statement about alkanes is correct?  a they burn in oxygen.  b they contain carbon, hydrogen and oxygen atoms.  c they contain double bonds.  d they contain ionic bonds.      37 what is an advantage of manufacturing ethanol by fermentation?  a the process is very fast.  b the ethanol requires no separation.  c the raw materials used are renewable.  d there are no other products formed.     ",
            "13": "13     \u00a9 ucles 2021 0620/21/m/j/21  38 p, q, r and s are four organic compounds.    p is an unsaturated hydrocarbon.    q burns but otherwise is unreactive.    r contains a c\u2013c single bond and a c=c double bond.    s undergoes addition polymerisation.    which compounds are alkenes?  a p and r only b p, r and s c p, q and s d q, r and s    39 the structure of a synthetic polymer is shown.    co co c co o n hn hn hn hco     the structure shows that it is a ..1.. . it is formed b y ..2.. polymerisation.    which words complete gaps 1 and 2?     1  2   a polyamide addition  b polyamide condensation  c polyester addition  d polyester condensation     40 which substance is a natural polymer?  a ethene  b terylene   c nylon  d protein    ",
            "14": "14  \u00a9 ucles 2021 0620/21/m/j/21  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/21/m/j/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/21/m/j/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s21_qp_22.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 06_0620_22/2rp   \u00a9 ucles 2021   [turn ove r   *4675923471 *cambridge igcse\u2122       chemistry 0620/22     paper 2 multiple choice (extended)  may/june 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/22/m/j/21  1 a gas is released at point p in the apparatus shown.    p damp universal indicator pape r    which gas turns the damp universal indicator paper red most qui ckly?  a ammonia, nh 3  b chlorine, c l 2  c hydrogen chloride, hc l  d sulfur dioxide, so 2    2 a mixture of colourless compoun ds is separated using chromatog raphy.    which type of reagent is used to detect these compounds after s eparation?  a a dehydrating agent  b a locating agent  c an oxidising agent  d a reducing agent    3 which statement about paper chromatography is correct?  a a solvent is needed to dissolve the paper.  b paper chromatography separates mixtures of solvents.  c the solvent should cover the baseline.  d the baseline should be drawn in pencil.    4 element x has 7 protons.    element y has 8 more protons than x.    which statement about element y is correct?  a y has more electron shells than x.  b y has more electrons in its outer shell than x.  c y is in a different group of the periodic table from x.  d y is in the same period of the periodic table as x.    ",
            "3": "3     \u00a9 ucles 2021 0620/22/m/j/21 [turn over  5 a covalent molecule q contains only six shared electrons.    what is q?  a ammonia, nh 3  b chlorine, c l 2  c methane, ch 4  d water, h 2o      6 information about four substances e, f, g and h is shown.     melting point  / \uf0b0c electrical conductivity  e 1710 does not conduct when solid  f 3500 conducts when solid  g 120 does not conduct  h 801 conducts when molten    e, f, g and h are graphite, poly(ethene), sodium chloride and s ilicon( iv) oxide but not in that  order.    what are e, f, g and h?     e  f  g  h   a graphite poly(ethene) silicon( iv) oxide sodium chloride  b sodium chloride graphite poly(ethene) silicon( iv) oxide  c poly(ethene) sodium chloride graphite silicon( iv) oxide  d silicon( iv) oxide graphite poly(ethene) sodium chloride      7 chemical compounds formed from a group i element and a group vi i element contain ionic  bonds.    how are the ionic bonds formed?  a electrons are transferred from group vii atoms to group i atoms .  b electrons are shared between group i atoms and group vii atoms.   c electrons are lost by group i atoms and group vii atoms.  d electrons are transferred from group i atoms to group vii atoms .    ",
            "4": "4  \u00a9 ucles 2021 0620/22/m/j/21  8 some information about particles p, q, r and s is shown.     nucleon  number number of  neutrons number of  electrons  p 12 6 6  q 24 12 10  r 16 8 10  s 14 8 6    which two particles are isotopes of the same element?  a p and q b p and s c q and r d r and s    9 chlorine gas will react with iron metal.    exactly 21.3  g of chlorine reacts with 11.2  g of iron.    how many iron atoms react with 30 molecules of chlorine?  a 10 b 15 c 20 d 30    10 in separate experiments, electricity was passed through concen trated aqueous sodium chloride  and molten lead( ii) bromide.    what would happen in both  experiments?  a a halogen would be formed at the anode.  b a metal would be formed at the cathode.  c hydrogen would be formed at the anode.  d hydrogen would be formed at the cathode.     11 a reaction involving aluminium is shown.    xa l  +  yo 2  +  6h 2o  \uf0ae  xa l (oh) 3    which values of x and y balance the equation?     x  y   a 2 3  b 3 2  c 3 4  d 4 3     ",
            "5": "5     \u00a9 ucles 2021 0620/22/m/j/21 [turn over  12 four different fuels are used to heat a beaker of water, for th e same amount of time, using the  apparatus shown.    stirrer spirit burner fuelscreen to  reduce draughtsthermometer 200  g of water     the initial temperature of the water and the temperature after heating by the fuel are recorded.    which fuel releases the most heat energy?     initial temperature  / \uf0b0c temperature after  heating  / \uf0b0c  a 17 46  b 24 52  c 26 61  d 30 62     ",
            "6": "6  \u00a9 ucles 2021 0620/22/m/j/21  13 an excess of calcium carbonate reacts with dilute hydrochloric acid. the volume of  carbon dioxide produced is measured at regular time intervals. the results are shown as  experiment 1.    the experiment is repeated with only one change to the reaction conditions.    the results are shown as experiment 2.    volume of co2 timeexperiment 2 experiment 1     which change is made in experiment 2?  a the concentration of the acid is increased.  b the volume of acid is increased.  c the mass of calcium carbonate is increased.  d the calcium carbonate is powdered.      14 when sulfur is heated it undergoes a ..1.. change as it  melts.    further heating causes the sulfur to undergo a ..2.. ch ange and form sulfur dioxide.    which words complete gaps 1 and 2?     1  2   a chemical chemical  b chemical physical  c physical chemical  d physical physical     ",
            "7": "7     \u00a9 ucles 2021 0620/22/m/j/21 [turn over  15 four statements about the effect of increasing temperature on a reaction are shown.    1 the activation energy becomes lower.  2 the particles move faster.  3 there are more collisions betw een reacting particles per seco nd.  4 there are more collisions which have energy greater than the activation energy.    which statements are correct?  a 1, 2 and 3 b 1, 3 and 4 c 2, 3 and 4 d 2 and 3 only     16 an example of a redox reaction is shown.    zn  +  cu 2+  \uf0ae  zn2+  +  cu    which statement about the reaction is correct?  a zn is the oxidising agent and it oxidises cu2+.  b zn is the oxidising agent and it reduces cu2+.  c zn is the reducing agent and it oxidises cu2+.  d zn is the reducing agent and it reduces cu2+.     17 when bismuth( iii) chloride, bic l 3, reacts with water, a white precipitate of bismuth( iii)  oxychloride, bioc l, is formed. the equation for the reaction is shown.    bic l 3(aq)  +  h 2o(l)    bioc l (s)  +  2h+(aq)  +  2c l \u2013(aq)    the reaction is in equilibrium.    which changes cause the white precipitate to dissolve?    1 adding acid  2 adding water 3 adding sodium chloride solution    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    ",
            "8": "8  \u00a9 ucles 2021 0620/22/m/j/21  18 element x forms an oxide, xo, that neutralises sulfuric acid.    which row describes x and xo?     element x nature of oxide, xo  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic     19 information about the solubility of salts is shown.    salt solubility  chlorides soluble (except for lead( ii) chloride and silver chloride)  nitrates soluble  sulfates soluble (except for barium sulfate and lead( ii) sulfate)    aqueous solutions of which two compounds would produce a precip itate when added together?  a b a ( n o 3)2 and cac l 2  b c u s o 4 and zn(no 3)2  c k c l and na 2so 4  d p b ( n o 3)2 and mgso 4     ",
            "9": "9     \u00a9 ucles 2021 0620/22/m/j/21 [turn over  20 the equation shows the reaction between hydrogen and oxygen.    2 h\u2013h  +  o=o  \uf0ae  2 h\u2013o\u2013h    the bond energies are shown.     bond energy  in kj  / mol  h\u2013h 436  o=o 495  o\u2013h 463    which row shows the energy change and the type of reaction?     energy change  in kj  / mol type of reaction  a 441 exothermic  b 441 endothermic  c 485 exothermic  d 485 endothermic      21 burning fossil fuels releases sulfur dioxide which leads to ac id rain.    which ion in the rain water causes it to be acidic?  a h+ b o h\u2013 c o2\u2013 d s o 42\u2013     22 which statement about the trends shown by the elements of perio d 3 in the periodic table is not  correct?  a the elements become less metallic across the period.  b the group number increases across the period.  c the number of electron shells increases across the period.  d the number of outer electrons increases across the period.    ",
            "10": "10  \u00a9 ucles 2021 0620/22/m/j/21  23 the diagram shows the positions of elements e, f, g and h in th e periodic table.    e fg h     which statements about elements e, f, g and h are correct?    1 e has a higher density than f.  2 e has a higher melting point than f.  3 g has a darker colour than h. 4 g has a lower melting point than h.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     24 when aqueous iodine is added to a solution of vanadium ions, v 2+, the v2+ ions each lose one  electron.    which property of transition elem ents is shown by this reaction ?  a transition elements have variable oxidation states.  b transition elements form a stable 1+ ion.  c transition elements are oxidising agents.  d transition elements can act as catalysts.    25 a piece of aluminium is dropped into dilute hydrochloric acid.    no immediate reaction is observed.    which statement explains this observation?  a aluminium does not neutralise acids.  b aluminium is a non-metal so does not react with acids.  c aluminium is below hydrogen in the reactivity series.  d aluminium is covered in an unreactive oxide layer.    ",
            "11": "11     \u00a9 ucles 2021 0620/22/m/j/21 [turn over  26 some metal nitrates and carbonates decompose when heated strong ly.    metal q has a nitrate that decomposes to give a salt and a colo urless gas only.    the carbonate of metal q does not decompose when heated with a bunsen burner.    what is metal q?  a calcium  b copper  c s o d i u m   d z i n c      27 aluminium is extracted from its ore by electrolysis.    which equation represents the reaction that occurs at the anode  during the electrolysis?  a a l  3+  +  3e\u2013  \uf0ae  a l  b a l 3+  \uf0ae  a l  +  3e\u2013  c 2 o2\u2013  \uf0ae  o 2  +  4e\u2013  d 2 o2\u2013  +  2e\u2013  \uf0ae  o 2     28 mild steel consists mostly of iron. mild steel can be prevented  from rusting by a process called  galvanising.    copper is not a very st rong metal, however if it is mixed with a suitable metal a strong alloy called  brass is produced.    which statement is correct?  a copper corrodes very quickly when wet and brass does not.  b copper is mixed with zinc to produce brass.  c galvanising mild steel changes it from a pure metal into an al loy.  d when a steel object is galvanised this means it is coated with  a thin layer of tin.     29 water is used for the irrigation of crops and for drinking wate r.    for which uses must water be chlorinated?     irrigation drinking  a \u0016 \u0016  b \u0016 \u001a  c \u001a \u0016  d \u001a \u001a ",
            "12": "12  \u00a9 ucles 2021 0620/22/m/j/21  30 which natural resource cannot  provide a raw material for the manufacture of ammonia?  a air  b limestone  c petroleum  d water      31 ammonia is made in the haber process.    which conditions are used in the haber process?     temperature  / \uf0b0c pressure  / atmospheres catalyst used  a 450 200 iron  b 450 5 vanadium( v) oxide  c 200 450 iron  d 200 5 vanadium( v) oxide     32 which process in the carbon cycle is responsible for removing c arbon dioxide from the  atmosphere?  a combustion  b decomposition  c photosynthesis  d respiration    33 the equations represent two reactions, p and q, of lime (calciu m oxide).    p cao  +  sio 2  \uf0ae  casio 3  q cao  +  so 2  \uf0ae  caso 3    in which processes do the reactions occur?     p  q   a extraction of iron extraction of iron  b extraction of iron flue gas desulfurisation  c flue gas desulfurisation extraction of iron  d flue gas desulfurisation flue gas desulfurisation     ",
            "13": "13     \u00a9 ucles 2021 0620/22/m/j/21 [turn over  34 which statement about ethanol is not correct?  a ethanol can be made by fermentation.  b ethanol is oxidised to make ethanoic acid.  c ethanol reacts with oxygen exothermically, making it a good fue l.  d ethanol reacts with propanoic acid to make propyl ethanoate.      35 which pair of formulae represents two alkanes?  a c h 4 and c 8h18  b c 2h6 and c 5h8  c c 3h6 and c 5h12  d c 10h8 and c 4h8      36 which statement about alkanes is correct?  a they burn in oxygen.  b they contain carbon, hydrogen and oxygen atoms.  c they contain double bonds.  d they contain ionic bonds.      37 which statements about ethanoic acid are correct?    1 it is a strong acid.  2 it reacts with ethanol to form an ester. 3 it has the formula ch 3cooh.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    ",
            "14": "14  \u00a9 ucles 2021 0620/22/m/j/21  38 the flow chart shows how petroleum may be turned into a plastic .    petroleum plasticsaturated hydrocarbonunsaturated hydrocarbonprocess 1process 2process 3     what are processes 1, 2 and 3?     process 1 process 2 process 3  a cracking fractional distillation polymerisation  b cracking polymerisation fractional distillation  c fractional distillation cracking polymerisation  d fractional distillation polymerisation cracking     39 the structure of a synthetic polymer is shown.    co co c co o n hn hn hn hco     the structure shows that it is a ..1.. . it is formed b y ..2.. polymerisation.    which words complete gaps 1 and 2?     1  2   a polyamide addition  b polyamide condensation  c polyester addition  d polyester condensation     40 which substance is a natural polymer?  a ethene  b terylene   c nylon  d protein    ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/22/m/j/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/22/m/j/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s21_qp_23.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 06_0620_23/2rp   \u00a9 ucles 2021   [turn ove r   *5240957555 *cambridge igcse\u2122       chemistry 0620/23     paper 2 multiple choice (extended)  may/june 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/23/m/j/21  1 a gas is released at point p in the apparatus shown.    p damp universal indicator pape r    which gas turns the damp universal indicator paper red most qui ckly?  a ammonia, nh 3  b chlorine, c l 2  c hydrogen chloride, hc l  d sulfur dioxide, so 2    2 a  1  cm3 sample of substance x is taken. this is sample 1.    x is then converted to a different physical state and a 1  cm3 sample is taken. this is sample 2.    sample 2 contains more particles in the 1  cm3 than sample 1.    which process caused this increase in the number of particles i n 1  cm3?  a boiling of liquid x  b condensation of gaseous x  c evaporation of liquid x  d sublimation of solid x     3 which statement about paper chromatography is correct?  a a solvent is needed to dissolve the paper.  b paper chromatography separates mixtures of solvents.  c the solvent should cover the baseline.  d the baseline should be drawn in pencil.    4 element x has 7 protons.    element y has 8 more protons than x.    which statement about element y is correct?  a y has more electron shells than x.  b y has more electrons in its outer shell than x.  c y is in a different group of the periodic table from x.  d y is in the same period of the periodic table as x.   ",
            "3": "3     \u00a9 ucles 2021 0620/23/m/j/21 [turn over  5 a covalent molecule q contains only six shared electrons.    what is q?  a ammonia, nh 3  b chlorine, c l 2  c methane, ch 4  d water, h 2o      6 which statement explains why metals are malleable?  a the atoms release electrons to become cations.  b the electrons are free to move.  c the electrons and the cations are attracted to each other.  d the layers of ions can slide over each other.      7 which statement about isotopes of the same element is correct?  a they have different numbers of electrons.  b they have different numbers of neutrons.  c they have different numbers of protons.  d they have the same mass number.     8 the element silicon has the same structure as diamond.    which statement about silicon is correct?  a every silicon atom is bonded to three other atoms only.  b silicon has a high melting point.  c silicon is a good conductor of electricity.  d silicon is used as a lubricant.      9 three ionic compounds of vanadium have the formulae v 2o, vc l 2 and v 2o3.    what is the charge on the vanadium ion in each compound?     v 2o vc l 2 v2o3  a +1 \u20132 +2  b +1 +2 +3  c +2 \u20132 +2  d +2 +2 +3 ",
            "4": "4  \u00a9 ucles 2021 0620/23/m/j/21  10 in separate experiments, electricity was passed through concen trated aqueous sodium chloride  and molten lead( ii) bromide.    what would happen in both  experiments?  a a halogen would be formed at the anode.  b a metal would be formed at the cathode.  c hydrogen would be formed at the anode.  d hydrogen would be formed at the cathode.    11 the equation for the decomposition of calcium carbonate is show n.    caco 3  \uf0ae  cao  +  co 2    what mass of calcium oxide is produced when 10  g of calcium carbonate is heated?  a 4 . 4  g b 5 . 0  g c 5 . 6  g d 10.0  g     12 gas syringe x contains 100  cm3 of hydrogen bromide gas, hbr.    gas syringe y contains 100  cm3 of carbon dioxide gas. the volume of each gas is measured at  room temperature and pressure.    which statement is correct?  a the mass of hbr is less than the mass of co 2.  b the number of molecules of hbr equals the number of molecules o f co 2.  c the gas in syringe x contains more atoms than the gas in syring e y.  d the number of moles of hbr is more than the number of moles of co 2.    ",
            "5": "5     \u00a9 ucles 2021 0620/23/m/j/21 [turn over  13 which simple cell produces the most electrical energy?    va magnesium zincv vb iron zinc vc magnesium coppervd iron copperkey = voltmete r      14 when sulfur is heated it undergoes a ..1.. change as it  melts.    further heating causes the sulfur to undergo a ..2.. ch ange and form sulfur dioxide.    which words complete gaps 1 and 2?     1  2   a chemical chemical  b chemical physical  c physical chemical  d physical physical     ",
            "6": "6  \u00a9 ucles 2021 0620/23/m/j/21  15 four statements about the effect of increasing temperature on a reaction are shown.    1 the activation energy becomes lower.  2 the particles move faster.  3 there are more collisions betw een reacting particles per seco nd.  4 there are more collisions which have energy greater than the activation energy.    which statements are correct?  a 1, 2 and 3 b 1, 3 and 4 c 2, 3 and 4 d 2 and 3 only     16 an example of a redox reaction is shown.    zn  +  cu 2+  \uf0ae  zn2+  +  cu    which statement about the reaction is correct?  a zn is the oxidising agent and it oxidises cu2+.  b zn is the oxidising agent and it reduces cu2+.  c zn is the reducing agent and it oxidises cu2+.  d zn is the reducing agent and it reduces cu2+.    ",
            "7": "7     \u00a9 ucles 2021 0620/23/m/j/21 [turn over  17 the equation for the decomposition of hydrogen iodide is shown.     2hi  \uf0ae  h2  +  i2    some bond energies are shown.    bond bond energy  in kj  / mol  h\u2013h 440  i\u2013i 1 5 0   h\u2013i 3 0 0     what is the energy change for the reaction?  a \u2013290  kj / mol b \u2013 1 0  kj / mol c + 1 0  kj / mol d + 2 9 0  kj / mol    18 element x forms an oxide, xo, that neutralises sulfuric acid.    which row describes x and xo?     element x nature of oxide, xo  a metal acidic  b metal basic  c non-metal acidic  d non-metal basic     19 aqueous solutions of sodium sulfate and barium chloride are mi xed.    na 2so 4(aq)  +  bac l 2(aq)  \uf0ae  baso 4(s)  +  2nac l (aq)    which process is used to separate a sample of barium sulfate fr om the reaction mixture?  a precipitation  b filtration  c evaporation  d distillation     ",
            "8": "8  \u00a9 ucles 2021 0620/23/m/j/21  20 information about element j is shown.    \u25cf its atoms have four electrons in their outer shell.  \u25cf it is a non-metal.  \u25cf its oxide has a macromolecular structure.  \u25cf it has a high melting point.    what is j?  a beryllium  b carbon  c silicon  d s u l f u r      21 which property is shown by transition elements?  a low density  b low melting point  c variable oxidation state  d white compounds     22 helium and neon exist as monoatomic gases at room temperature and pressure.    statement 1 helium and neon have eight electrons in their outer  shell.  statement 2 helium and neon are unreactive.    which option is correct?  a statement 1 and statement 2 are incorrect.  b statement 1 is correct and explains statement 2.  c statement 1 is correct, but does not explain statement 2.  d statement 1 is incorrect, but statement 2 is correct.     ",
            "9": "9     \u00a9 ucles 2021 0620/23/m/j/21 [turn over  23 what are possible effects of an inadequate water supply during a drought?    1 crop failure  2 wastage of water  3 human disease  4 death of farm animals    a 1, 2 and 3 b 1 and 2 only c 1, 3 and 4 d 3 and 4 only    24 which statement explains why galvanising prevents iron from rus ting?  a zinc is more reactive than iron and corrodes in preference to i ron.  b zinc is more reactive than iron and loses electrons less easily  than iron.  c zinc is less reactive than iron and corrodes in preference to i ron.  d zinc is less reactive than iron and loses electrons more easily  than iron.     25 some metal nitrates and carbonates decompose when heated strong ly.    metal q has a nitrate that decomposes to give a salt and a colo urless gas only.    the carbonate of metal q does not decompose when heated with a bunsen burner.    what is metal q?  a calcium  b copper  c s o d i u m   d z i n c       26 which compounds are released by the extraction of zinc from zin c blende and by respiration?     extraction of zinc respiration  a co 2 and so 2 c o 2 only  b co 2 and so 2 c o 2 and h 2o  c co 2 only co 2 only  d co 2 only co 2 and h 2o     ",
            "10": "10  \u00a9 ucles 2021 0620/23/m/j/21  27 which gas is an air pollutant that causes acid rain?  a argon  b carbon monoxide  c methane  d nitrogen dioxide      28 ammonia is made from nitrogen and hydrogen. the equation for th e reaction is shown.    n2(g)  +  3h 2(g)    2nh 3(g)    the forward reaction is exothermic.    which conditions give the greatest equilibrium yield of ammonia ?     temperature  / \uf0b0c pressure  / atm  a 200 15  b 200 150  c 500 15  d 500 150      29 which reaction does not occur during the extraction of iron from hematite in a blast f urnace?  a c  +  o 2  \uf0ae  co 2  b cao  +  sio 2  \uf0ae  casio 3  c c o 2  +  c  \uf0ae  2co  d 4fe  +  3o 2  \uf0ae  2fe 2o3      30 which substance is used as a catalyst in the manufacture of sul furic acid by the contact  process?  a iron  b nickel  c phosphoric acid  d vanadium( v) oxide     ",
            "11": "11     \u00a9 ucles 2021 0620/23/m/j/21 [turn over  31 metal x is a good conductor of electricity and is used for elec trical wiring.    metal y is used to make an alloy which is resistant to corrosio n and is used to make cutlery.    metal z is light and strong and is used in the manufacture of a ircraft.    what are x, y and z?     x  y  z   a aluminium iron copper  b copper iron aluminium  c aluminium copper iron  d copper aluminium iron      32 the formulae of two compounds of manganese are mno 2 and kmno 4.    in these two compounds the oxidation state of potassium is +1 a nd the oxidation state of oxygen  is \u20132.    what are the oxidation states of manganese in each of these two  compounds?     m n o 2 k m n o 4  a +2 +3  b +2 +7  c +4 +3  d +4 +7     33 which statement about calcium carbonate is correct?  a it is made by the thermal decomposition of limestone.  b it is used to neutralise alkaline soils.  c it is a reactant in the test for carbon dioxide.  d it is used to remove impurities in iron extraction.    ",
            "12": "12  \u00a9 ucles 2021 0620/23/m/j/21  34 ethanol is reacted with acidified potassium manganate( vii).    which row describes the type of reaction and the type of organi c compound formed?     type of reaction organic compound  a oxidation carboxylic acid  b oxidation alkene  c dehydration carboxylic acid  d dehydration alkene     35 the diagrams show the structural formulae of four compounds.    c hh hch hc1 h hch hch hh c hh hc hc2 hch ch hh c h hh c hh hch c3 h hch hh c hh hc hc4 hch ch h h hh c h hh c h hh     which two compounds are structural isomers?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     36 which statement about alkanes is correct?  a they burn in oxygen.  b they contain carbon, hydrogen and oxygen atoms.  c they contain double bonds.  d they contain ionic bonds.    ",
            "13": "13     \u00a9 ucles 2021 0620/23/m/j/21  37 how much hydrogen is needed to react completely with 0.02 moles  of butene to make butane?  a 0 . 2 4  dm3 b 0 . 4 8  dm3 c 0 . 9 6  dm3 d 1 . 2 0  dm3    38 what is an advantage of the fermentation process for producing ethanol compared with the  catalytic addition of steam to ethene?  a fermentation requires less heat energy.  b ethanol from fermentation needs to be distilled.  c raw materials for fermentation are non-renewable.  d the fermentation process is carried out in batches rather than continuously.    39 the structure of a synthetic polymer is shown.    co co c co o n hn hn hn hco     the structure shows that it is a ..1.. . it is formed b y ..2.. polymerisation.    which words complete gaps 1 and 2?     1  2   a polyamide addition  b polyamide condensation  c polyester addition  d polyester condensation      40 which substance is a natural polymer?  a ethene  b terylene   c nylon  d protein     ",
            "14": "14  \u00a9 ucles 2021 0620/23/m/j/21  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/23/m/j/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/23/m/j/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s21_qp_31.pdf": {
            "1": "*1847909074* chemistry  0620/31 paper 3 theory (core) may/june 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 06_0620_31/3rp \u00a9 ucles 2021 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/31/m/j/21 \u00a9 ucles 2021 1 (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td\tand\te,\tare\tshown. a b c d e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\telectronic\tstructures. \t\teach\telectronic\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\tstate\twhich\telectronic\tstructure,\t a,\tb,\tc,\td or e,\trepresents:  (i)\t\tan\tatom\tin\tgroup\tii\tof\tthe\tperiodic\t table  \t ...   [1]  (ii)\t\tan\tatom\twith\ta\tproton\tnumber\tof\t13  \t ...   [1]  (iii)\t\tan\tatom\tthat\tforms\ta\tstable\tion\twith\ta\tsingle\tnegative\tcharge  \t ...   [1]  (iv)\t\tan\tatom\tof\ta\tnon-metal\tthat\tforms\ta\tgiant\tcovalent\tstructure  \t ...   [1]  (v)\t\tan\tatom\tof\ta\tmetal\tused\tin\tfood\tcontainers.  \t ...   [1]  (b)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\tthe\tvanadium\t atom\tand\tcalcium\tion\tshown. number\tof electronsnumber\tof neutronsnumber\tof protons 51v23 23 48ca2+ 20 28 \t [3] \t [total:\t8]",
            "3": "3 0620/31/m/j/21 \u00a9 ucles 2021 [turn over 2\t\tthe\ttable\tshows\tthe\tmasses\tof\tsome\tof\tthe\tions \tin\t1000\tcm3\tof\tfruit\tjuice. name\tof\tion formula\tof\tionmass\tof\tion\tin\t1000\t cm3 of\tfruit\tjuice\t /\tmg nh4+43 calcium ca2+79 chloride cl \u2013135 lithium li+1 magnesium mg2+80 nitrate no3\u201335 phosphate po43\u2013120 potassium k+575 sodium na+120 so42\u2013105  (a)\t\tanswer\tthese\tquestions\tusing\tonly\tthe\tinformation\t in\tthe\ttable.  (i)\t\tstate\twhich\tnegative\tion\thas\tthe\thighest\tmass\tin\t1000\t cm3\tof\tfruit\tjuice.  \t ...   [1]  (ii)\t\tgive\tthe\tformulae\tof\tthe\tions\tin\tammonium\tsulfate. \t \tand\t\t ...   [1]  (iii)\t\tcalculate\tthe\tmass\tof\tsodium\tions\tin\t200\t cm3\tof\tfruit\tjuice. \t mass\t=\t..\tmg\t\t[1]  (b)\t\tdescribe\ta\ttest\tfor\tlithium\tions.  test \t. \t observations\t \t..  [2]  (c)\t\tions\tof\tthe\telement\tpotassium,\tk,\tare\tpresent\tin\tmost\tfertilisers. \t\tstate\tthe\tnames\tof\ttwo\tother\telements\tthat\tare\tin\tmost\tfertilisers.  1 \t.  2 \t.  [2]",
            "4": "4 0620/31/m/j/21 \u00a9 ucles 2021  (d)\t\torange\tjuice\tis\tacidic. \t\tdraw\ta\tcircle\taround\tthe\tph\tof\torange\tjuice.  ph 4              ph 7              ph 10              ph 13 [1]  (e)\t\tsome\tsoils\tare\tacidic. \t\tgive\tthe\tnames\tof\ttwo\tcompounds\tthat\tare\tused\tto\tmake\tsoils\tless\tacidic.  1 \t.  2 \t.  [2]  (f)\t\thydrogen\t chloride\tis\tan\tacidic\tgas\tproduced\twhen\tconcentrated\t hydrochloric\t acid\tevaporates.\t  (i)\t\tdescribe\tthe\tarrangement\tand\tseparation\tof\tthe\tmolecules\tin\thydrogen\tchloride\tgas. \t arrangement\t \t ...  \t . \t separation\t \t ...  \t .  [2]  (ii)\t\ta\tlong\tglass\ttube\tis\tset\tup\tas\tshown. long glass tube cotton wool soaked in concentrated hydrochloric aciddamp blue litmus paper \t \tat\tfirst,\tthe\tblue\tlitmus\tpaper\tdoes\tnot\tturn\tred.\t \t \tafter\ta\tshort\ttime,\tthe\tlitmus\tpaper\tturns\tred. \t explain\tthese\tobservations\tusing\tthe\tkinetic\tparticle\tmodel.  \t .  \t .  \t .  \t .  \t ... \t\t[3] \t [total:\t15]",
            "5": "5 0620/31/m/j/21 \u00a9 ucles 2021 [turn over 3\t\tthe\ttable\tshows\tsome\tproperties\tof\tfour\tgroup\ti \telements. elementmelting\tpoint / \u00b0cboiling\tpoint / \u00b0catomic\tradius /\tnm sodium 98 883 0.191 potassium 63 760 rubidium 39 0.250 caesium 29 671 0.272  (a) (i)\t\tcomplete\tthe\ttable\tby\tpredicting:  \u25cf\tthe\tboiling\tpoint\tof\trubidium  \u25cf\tthe\tatomic\tradius\tof\tpotassium.  [2]  (ii)\t\tdescribe\tthe\ttrend\tin\tthe\tmelting\tpoint\tof\tthe\tgroup\ti\telements\tdown\tthe\tgroup.  \t ...   [1]  (iii)\t\tdeduce\tthe \tphysical\tstate\tof\tpotassium\tat\t60\t \u00b0c. \t \texplain\tyour\tanswer.  \t .  \t .  \t ...   [2]  (b)\t\tcaesium\tis\ta\tradioactive\telement\twith\ta\tproton\tnumber\tof\t55.  (i)\t\tdefine\tproton\tnumber.  \t ...   [1]  (ii)\t\tstate\tone\tindustrial\tuse\tof\tradioactive\tisotopes.  \t ...   [1]  (c)\t\tsodium\thydride,\tnah,\treacts\twith\tiron( iii)\toxide.  (i)\t\tbalance\tthe \tequation\tfor\tthis\treaction.  fe2o3\t\t+\t\t3nah\t\t\u2192\t\t.fe\t\t+\t\t.naoh\t [2]  (ii)\t\texplain\thow \tthis\tequation\tshows\tthat\tiron( iii)\toxide\tis\treduced.  \t ...   [1] \t [total:\t10]",
            "6": "6 0620/31/m/j/21 \u00a9 ucles 2021 4\t\tthe\tstructure\tof\tmalic\tacid\tis\tshown. c chooh ho ch ch ooh  (a) (i)\t\ton\tthe\tstructure\tdraw\ta\tcircle\taround\tthe\talcohol\tfunctional\tgroup.\t [1]  (ii)\t\tdeduce\tthe\tformula\tof\tmalic\tacid\tto\tshow\tthe\tnumber\tof\tcarbon,\thydrogen\t and\toxygen\t atoms.  \t ...   [1]  (b)\t\twhen\tmalic\tacid\tis\theated\tit\tforms\tcompound\t f. \t\tthe\tstructure\tof\tcompound\tf\tis\tshown. c chooh c ch ooh \t\texplain\twhy\tcompound\t f\tis\tdescribed\tas\tunsaturated.  \t..   [1]  (c)\t\tcompound\t f\tcan\tform\tpolymers.  (i)\t\tstate\tthe\tmeaning\tof\tthe\tterm\tpolymer .  \t .  \t ...   [2]  (ii)\t\tstate\tthe\tname\tof\tthe\tpolymer\tformed\twhen\tethene\tis\tpolymerised.  \t ...   [1]",
            "7": "7 0620/31/m/j/21 \u00a9 ucles 2021 [turn over  (d)\t\tethanoic\tacid\tis\ta\tcarboxylic\tacid. \t\tdescribe\tthe\tobservations\tmade\twhen\tdilute\tethanoic\tacid\treacts\twith: \t magnesium\t \t \t litmus\tsolution.\t \t...  [2]  (e)\t\tthe\tgraph\tshows\thow\tthe\tph\tchanges\twhen\tdilute\tethanoic\tacid\tis\tadded\tslowly\tto\taqueous\t sodium\thydroxide. 14 12 10 8 6 4 2 0 10 20 volume of dilute ethanoic acid added  / cm330 40ph  (i)\t\tdeduce\tthe\tph\tof\tthe\taqueous\tsodium\thydroxide\t before\tthe\taddition\tof\tdilute\tethanoic\tacid. \t ph\t=\t..\t\t[1]  (ii)\t\tdeduce\tthe \tvolume\tof\tdilute\tethanoic\tacid\tadded\twhen\tthe\tph\tis\tneutral. \t ..\tcm3  [1] \t [total:\t10]",
            "8": "8 0620/31/m/j/21 \u00a9 ucles 2021 5 (a)\t\tcalcium\toxide\tis\tmade\tby\tthe\tthermal\tdecomposition\tof\tcalcium\tcarbonate.  (i)\t\tstate\tthe\tmeaning\tof\tthe\tterm\tthermal decomposition .  \t .  \t ...   [2]  (ii)\t\tdescribe\ta\t test\tfor\tcalcium\tions.  test \t .. \t observations\t \t ...  [2]  (b)\t\tcarbon\tdioxide\tis\tproduced\twhen\tdilute\thydrochloric\tacid\treacts\twith\tcalcium\tcarbonate. caco3  +  2hcl  \u2192\t\tcacl 2  +  co2  +  h2o  (i)\t\tcomplete\t the\tdiagram\tto\tshow\thow\tto\tmeasure\tthe\tvolume\tof\tcarbon\tdioxide\tproduced\t during\tthis\treaction. dilute hydrochloric acid calcium carbonat e  [2]",
            "9": "9 0620/31/m/j/21 \u00a9 ucles 2021 [turn over  (ii)\t\tdescribe\tthe\teffect\tof\teach\tof\tthe\tfollowing\ton\tthe\trate\tof\treaction\tof\tdilute\thydrochloric\t acid\t with\tcalcium\tcarbonate.  \u25cf\tthe\tconcentration\tof\thydrochloric\tacid\tis\tdecreased. \t \tall\tother\tconditions\tstay\tthe\tsame.  \t .  \u25cf\tthe\ttemperature\tis\tincreased. \t \tall\tother\tconditions\tstay\tthe\tsame.  \t .  [2]  (c)\t\tcarbon\tdioxide\tis\talso\tformed\twhen\tthe\thydrocarbon\tc3h8\tis\tcompletely\tcombusted.  (i)\t\tstate\tthe\tmeaning\tof\tthe\tterm\thydrocarbon.  \t .  \t ...   [2]  (ii)\t\tthe\thydrocarbon\tc3h8\tis\tcalled\tpropane. \t \tname\tthe\thomologous\tseries\tthat\tpropane\tbelongs\tto.  \t ...   [1]  (iii)\t\tname\ttwo\tsubstances\tformed\tby\tthe\tincomplete\tcombustion\tof\tpropane. \t \tand\t\t ...   [2] \t [total:\t13]",
            "10": "10 0620/31/m/j/21 \u00a9 ucles 2021 6\t\tthis\tquestion\tis\tabout\twater.  (a)\t\tthe\twater\tin\trivers\toften\tcontains\tpollutants\tsuch\tas \tacids. \t\tdescribe\thow\tuniversal\tindicator\tpaper\tcan\tbe\tused\tto\tdetermine\tthe\tph\tvalue\tof\tthe\twater.  \t  \t  \t..   [2]  (b)\t\tthe\tdiagram\tshows\tsome\tof\tthe\tstages\tin\twater\ttreatment. impure wateraeration tankmixing tank chlorine airpurified waterfilter  (i)\t\tair\tis\tblown \tthrough\tthe\taeration\ttank. \t \tname\tthe\ttwo\tgases\tthat\tmake\tup\tmost\tof\tthe\tair. \t \tand\t\t ...   [2]  (ii)\t\tafter\taeration,\tthe\twater\tstill\tcontains\tlarge\tinsoluble\tparticles. \t \tthe\tfilter\tis\tmade\tup\tof\tfine\tsand\tand\tstones. \t \texplain\thow\tthe\tfilter\thelps\tpurify\tthe\twater.  \t .  \t .  \t ...   [2]  (iii)\t\texplain\twhy\tchlorine\tis\tused\tin\twater\ttreatment.  \t ...   [1]  (c)\t\tanhydrous\tcobalt( ii)\tchloride\tis\tused\tto\ttest\tfor\twater. \t\tstate\tthe\tcolour\tchange\tin\tthis\ttest. \t from\t\tto\t \t   [2] \t [total:\t9]",
            "11": "11 0620/31/m/j/21 \u00a9 ucles 2021 [turn over 7 (a)\t\tmolten\tlead( ii)\tbromide\tis\telectrolysed\tusing\tcarbon\telectrodes.  (i)\t\tstate\tthe\tproducts\tof\tthis\telectrolysis\tat: \t the\tnegative\telectrode\t \t  \t the\tpositive\telectrode.\t \t .  [2]  (ii)\t\tstate\tthe\tname\tof\tanother\tsubstance\twhich\tcan\tbe\tused\tas\tan\tinert\telectrode.  \t ...   [1]  (b)\t\twhen\taqueous\tmagnesium\t chloride\tis\telectrolysed \tusing\tcarbon\telectrodes,\t hydrogen\t gas\tis\t produced\tat\tthe\tnegative\telectrode. \t\tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\tone\tmolecule\t of\t hydrogen.  [1] \t [total:\t4]",
            "12": "12 0620/31/m/j/21 \u00a9 ucles 2021 8\t\tthis\tquestion\tis\tabout\telements\tin\tthe\tperiodic\t table.  (a)\t\tthe\ttable\tshows\tsome\tproperties\tof\tfive\telements,\t p,\tq,\tr,\ts\tand\tt. elementmelting\tpoint / \u00b0cdensity in\tg\t/\tcm3electrical\tconductivity of\tthe\tsolidatomic\tradius /\tnm p 1535 7.86 very\tgood 0.125 q \u20137 3.12 does\tnot\tconduct 0.114 r 1495 8.90 very\tgood 0.126 s \u2013157 0.0035 does\tnot\tconduct 0.110 t 839 1.54 very\tgood 0.174 \t\tuse\tonly\tthe\telements\tshown\tin\tthe\ttable\tto\tanswer\tthis\tquestion. \t\tstate\twhich\ttwo\tof\tthe\telements,\tp,\tq,\tr,\ts\tand\tt,\tare\tcovalent\tmolecules. \t\tgive\ttwo\treasons\tfor\tyour\tanswer. \t elements\t..\tand\t \t.. \t reason\t1\t\t . \t reason\t2\t\t . \t [3]  (b)\t\telement\tt\tis\ton\tthe\tleft-hand\tside\tof\tthe\tperiodic\t table. \t\tsuggest\twhether\tits\toxide\tis\tacidic\tor\tbasic. \t\tgive\ta\treason\tfor\tyour\tanswer.  \t  \t..   [1]  (c)\t\tkrypton\tis\tan\telement\tin\tgroup\tviii\tof\tthe\tperiodic\t table. \t\texplain,\tusing\tideas\tabout\telectronic\tstructure,\twhy\tkrypton\tis\tunreactive.  \t  \t..   [1]",
            "13": "13 0620/31/m/j/21 \u00a9 ucles 2021 [turn over  (d)\t\tsodium\tis\tan\telement\tin\tgroup\ti\tof\tthe\tperiodic\t table.\tiron\tis\ta\ttransition\telement. \t\tiron\thas\ta\thigher\tmelting\tpoint\tand\thigher\tboiling\tpoint\tthan\tsodium. \t\tgive\t two\tother\tways\tin\twhich\tthe\tproperties\t of\ttransition\telements\tdiffer\tfrom\tthe\tproperties\t of\t group\ti\telements.  1 \t.  2 \t.  [2]  (e)\t\tthe\ttable\tcompares\tthe\treactivity\tof\tfour\tmetals\twith\tdilute\thydrochloric\tacid. metalreaction\twith dilute\thydrochloric\tacid calcium reacts\tvery\trapidly copper no\treaction iron reacts\trapidly nickel reacts\tslowly \t\tput\tthe\tfour\tmetals\tin\torder\tof\ttheir\treactivity. \t\tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]  (f)\t\thot\tiron\treacts\twith\tsteam.\t the\treaction\tis\treversible. \t\tcomplete\tthe\tequation\tby\twriting\tthe\tsymbol\tfor\ta\treversible\treaction\tin\tthe\tbox. 3fe\t\t+\t\t4h2o    fe3o4  +  4h2  [1]  (g)\t\tsteel\tis\tan\talloy\tof\tiron. \t\tstate\tthe\tmeaning\tof\tthe\tterm\talloy .  \t..   [1] \t [total:\t11]",
            "14": "14 0620/31/m/j/21 \u00a9 ucles 2021blank page",
            "15": "15 0620/31/m/j/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "16": "16 0620/31/m/j/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s21_qp_32.pdf": {
            "1": "*8693358623* chemistry  0620/32 paper 3 theory (core) may/june 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 06_0620_32/3rp \u00a9 ucles 2021 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/32/m/j/21 \u00a9 ucles 2021 1 (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td\tand\te,\tare\tshown. a b c d e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\telectronic\tstructures. \t\teach\telectronic\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\tstate\twhich\telectronic\tstructure,\t a,\tb,\tc,\td or e,\trepresents:  (i)\t\tan\tatom\tin\tgroup\tiii\tof\tthe\tperiodic\t table  \t ...   [1]  (ii)\t\tan\tatom\tof\ta\tnoble\tgas  \t ...   [1]  (iii)\t\tan\tatom\tthat\tforms\ta\tstable\tion\twith\ta\tsingle\tpositive\tcharge  \t ...   [1]  (iv)\t\tan\tatom\tthat\tcontains\tonly\ttwo\tshells\tof\t electrons  \t ...   [1]  (v)\t\tan\tatom\twith\ta\tproton\tnumber\tof\t16.  \t ...   [1]  (b)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\tthe\tsilicon\tatom\t and\tsodium\tion\tshown. number\tof electronsnumber\tof neutronsnumber\tof protons 30si14 14 23na+ 11 12  [3] \t [total:\t8]",
            "3": "3 0620/32/m/j/21 \u00a9 ucles 2021 [turn over 2\t\tthe\ttable\tshows\tthe\tmasses\tof\tsome\tof\tthe\tions \tin\t1000\tcm3\tof\tfruit\tjuice. name\tof\tion formula\tof\tionmass\tof\tion\tin\t1000\t cm3 of\tfruit\tjuice\t /\tmg ammonium nh4+15 ca2+71 chloride cl \u2013135 magnesium mg2+160 nitrate no3\u20132 phosphate po43\u201363 potassium k+184 sodium na+3 so42\u201385  (a)\t\tanswer\tthese\tquestions\tusing\tonly\tthe\tinformation\t in\tthe\ttable.  (i)\t\tstate\twhich\tpositive\tion\thas\tthe\tlowest\tmass\tin\t1000\t cm3\tof\tfruit\tjuice.  \t ...   [1]  (ii)\t\tgive\tthe\tformulae\tof\tthe\tions\tin\tcalcium \tsulfate. \t \tand\t\t ...   [1]  (iii)\t\tcalculate\tthe\tmass\tof\tmagnesium\tions\tin\t250\t cm3\tof\tfruit\tjuice. \t mass\t=\t..\tmg\t\t[1]  (b)\t\tdescribe\ta\ttest\tfor\tcalcium\tions.  test \t. \t observations\t \t..  [2]  (c)\t\tammonium\tions,\tnh4+,\tare\tpresent\tin\tmost\tfertilisers.\t ammonium\tions\tcontain\tnitrogen. \t\tname\ttwo\tother\telements\tpresent\tin\tmost\tfertilisers.  1 \t.  2 \t.  [2]",
            "4": "4 0620/32/m/j/21 \u00a9 ucles 2021  (d)\t\ta\tstudent\theated\ta\tmixture\tof\tammonium\tchloride\tand\tsodium\thydroxide\tin\ta\ttest\u2011tube. nh4cl\t\t+\t\tnaoh\t\t \u2192  nh3\t\t+\t\tnacl  +  h2o mixture of ammonium chloride and sodium hydroxid e heat \t\tpungent\u2011smelling\tammonia\tgas\tis\tgiven\toff.\t \t\tdescribe\tone\t other\tobservation\tthat\tcan\tbe\tmade.  \t..   [1]  (e)\t\tammonia\treacts\twith\tchlorine. \t\tcomplete\tthe\tequation\tfor\tthis\treaction. \t .nh3\t\t+\t\t.c l 2  \u2192  n2\t\t+\t\t6hcl [2]  (f)\t\ta\tsmall\tbeaker\tof\taqueous\tammonia\tis\tplaced\tat\tthe\tfront\tof\ta\tclassroom. \t\tat\tfirst,\tthe\tstudents\tat\tthe\tback\tof\tthe\tclass\tdo\tnot\tsmell\tthe\tammonia\tgas. \t\tafter\ta\tshort\ttime,\tthe\tstudents\tat\tthe\tback\tof\tthe\tclass\tsmell\tthe\tammonia. \t explain\tthese\tobservations\tusing\tthe\tkinetic\tparticle\tmodel.  \t  \t  \t  \t  \t..   [3] \t [total:\t13]",
            "5": "5 0620/32/m/j/21 \u00a9 ucles 2021 [turn over 3\t\tthe\ttable\tshows\tsome\tproperties\tof\tfour\thalogens. elementmelting\tpoint / \u00b0cboiling\tpoint / \u00b0cdensity\tof\tliquid\tat\t boiling\tpoint\tin\tg\t /\tcm3 colour chlorine \u2013101 \u201335 1.56 light\tgreen bromine \u20137 3.12 red\u2011brown iodine 114 184 dark\tgrey astatine 302 337 6.35 black  (a) (i)\t\tcomplete\tthe\ttable\tby\tpredicting:  \u25cf\tthe\tboiling\tpoint\tof\tbromine  \u25cf\tthe\tdensity\tof\tliquid\tiodine\tat\tits\tboiling\tpoint.  [2]  (ii)\t\tdescribe\tthe\ttrend\tin\tthe\tdepth\tof\tcolour \tof\tthe\thalogens\tdown\tthe\tgroup.  \t ...   [1]  (iii)\t\tdeduce\tthe \tstate\tof\tchlorine\tat\t\u201350\t \u00b0c. \t explain\tyour\tanswer.  \t .  \t .  \t ...   [2]  (b)\t\tthe\thalogens\thave\tmolecules\tthat\tare\tdiatomic. \t\texplain\tthe\tmeaning\tof\tthe\tterm\t diatomic.  \t..   [1]  (c)\t\tastatine\tis\ta\tradioactive\telement.\tone\tisotope\tof\tastatine\thas\ta\tnucleon\tnumber\tof\t209.  (i)\t\tdefine\tnucleon number .  \t ...   [1]  (ii)\t\tstate\tone\tmedical\tuse\tof\tradioactive\tisotopes.  \t ...   [1]  (iii)\t\tthe\tisotope \t235u\tis\talso\tradioactive. \t \tstate\tthe\tmajor\tuse\tof\tthis\tisotope\tof\turanium.  \t ...   [1] \t [total:\t9]",
            "6": "6 0620/32/m/j/21 \u00a9 ucles 2021 4\t\tthe\tstructure\tof\tsuccinic\tacid\tis\tshown. co cc co hhh h oh h o  (a) (i)\t\ton\tthe\tstructure\tdraw\ta\tcircle\taround\tone\tcarboxylic\tacid\tfunctional\tgroup.\t [1]  (ii)\t\tdeduce\tthe\tformula\tof\tsuccinic\tacid\tto\tshow\tthe\tnumber\tof\tcarbon,\thydrogen\t and\toxygen\t atoms.  \t ...   [1]  (b)\t\twhen\tsuccinic\tacid\tis\theated\tit\tundergoes\tsublimation. \t\tstate\tthe\tmeaning\tof\tthe\tterm\tsublimation .  \t  \t..   [1]  (c)\t\tsuccinic\tacid\tis\theated\twith\tcompound\t f. \t\tcompound\t f\thas\tthe\tformula\thoch2ch2oh.  (i)\t\tstate\tthe\tname\tof\tthe\t\u2013oh\tfunctional\tgroup\tin\tcompound\t f.  \t ...   [1]  (ii)\t\ta\tpolymer\tis\tformed\twhen\tsuccinic\tacid\t is\theated\twith\tcompound\t f.   choose one\tword\tfrom\tthe\tlist\tthat\tbest\tdescribes\t the\tsmall\tmolecules\t that\treact\ttogether\t to\tform\ta\tpolymer. \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer.  bases          ceramics          monomers          plastics  [1]  (d)\t\tethanoic\tacid\tis\talso\ta\tcarboxylic\tacid. \t\tdescribe\tthe\tobservations\tmade\twhen\tethanoic\tacid\treacts\twith: \t blue\tlitmus\tpaper\t \t... \t calcium\tcarbonate.\t \t  [2]",
            "7": "7 0620/32/m/j/21 \u00a9 ucles 2021 [turn over  (e)\t\ta\tstudent\u2019s\tgraph\tof\thow\tthe\tph\tchanges\twhen\taqueous\tsodium\thydroxide\t is\tadded\tslowly\tto\t dilute\tethanoic\tacid\tis\tshown. 14 12 10 8 6 4 2 0 0 10 20 volume of aqueous sodium hydroxide  / cm330 40ph  (i)\t\tdeduce\tthe\tph\tof\tthe\tdilute\tethanoic\tacid\tbefore\tthe\taddition\tof\taqueous\tsodium\thydroxide. \t ph\t=\t..\t\t[1]  (ii)\t\tdeduce\tthe \tvolume\tof\taqueous\tsodium\t hydroxide\tadded\twhen\tthe\tph\tis\tneutral. \t ..\tcm3  [1] \t [total:\t9]",
            "8": "8 0620/32/m/j/21 \u00a9 ucles 2021 5 (a)\t\tcalcium\tcarbonate\tis\theated\tin\ta\tclosed\tcontainer. caco3  \t\tcao\t\t+\t\tco2  (i)\t\tstate\tthe\tname\tof\ta\trock\twhich\tis\tmainly \tcalcium\tcarbonate.  \t ...   [1]  (ii)\t\tstate\tthe\tmeaning\tof\tthe\tsymbol\t .  \t ...   [1]  (iii)\t\tcao\tis\tlime.\tlime\tis\tused\tfor\tneutralising\tacidic\tindustrial\twaste. \t \tgive\tone\tother\tuse\tof\tlime.  \t ...   [1]  (iv)\t\tdescribe\ta\t test\tfor\tcarbon\tdioxide.  test \t .. \t observations\t \t ...  [2]  (b)\t\tcarbon\tdioxide\tis\tproduced\twhen\tdilute\thydrochloric\tacid\treacts\twith\tcalcium\tcarbonate. caco3  +  2hcl  \u2192\t\tcacl 2  +  co2  +  h2o  (i)\t\tcomplete\t the\tdiagram\tto\tshow\tthe\tapparatus\t used\tto\tinvestigate\t the\tvolume\tof\t carbon\tdioxide\tproduced\tduring\tthis\treaction. gas syringe  [2]",
            "9": "9 0620/32/m/j/21 \u00a9 ucles 2021 [turn over  (ii)\t\tdescribe\tthe\teffect\tof\teach\tof\tthe\tfollowing\ton\tthe\trate\tof\treaction\tof\tdilute\thydrochloric\t acid\t with\tcalcium\tcarbonate.  \u25cf\tthe\ttemperature\tis\tdecreased. \t all\tother\tconditions\tstay\tthe\tsame.  \t .  \u25cf\tcalcium\tcarbonate\tpowder\tis\tused\tinstead\tof\tlarge\tpieces\tof\tcalcium\tcarbonate. \t all\tother\tconditions\tstay\tthe\tsame.  \t .  [2]  (c)\t\tcarbon\tdioxide\tis\talso\tformed\twhen\tthe\thydrocarbon\tc4h8\tis\tcompletely\tcombusted.  (i)\t\tthe\thydrocarbon\tc4h8\tis\tan\talkene. \t \tcomplete\tthe\tstructure\tof\tthis\talkene\tby \tadding\tthe\tmissing\tbonds\tand\tatom. hch hch ch hhc  [2]  (ii)\t\tthe\tincomplete\tcombustion\tof\tc4h8\tproduces\tcarbon\tmonoxide. \t \tstate\tthe\tmeaning\tof\tthe\tterm\tincomplete combustion .  \t .  \t ...   [1] \t [total:\t12]",
            "10": "10 0620/32/m/j/21 \u00a9 ucles 2021 6\t\tthis\tquestion\tis\tabout\tair\tand\tgases.  (a) (i)\t\tstate\tthe\tpercentage\tof\toxygen\tin\tclean,\tdry\tair. \t ..\t%\t\t[1]  (ii)\t\tname\ttwo other\telements\tin\tclean,\tdry\t air. \t \tand\t\t ...   [2]  (b)\t\tlead\tand\tsulfur\tdioxide\tare\tpollutants\tof\tair. \t\tfor\teach\tof\tthese\tpollutants\t state\tthe\tsource\tof\tthe\tpollutant\tand\tan\tadverse\teffect\tof\tthe\t pollutant. \t source\tof\tlead\t \t \t adverse\teffect\t \t \t source\tof\tsulfur\tdioxide\t \t.. \t adverse\teffect\t \t  [4]  (c)\t\twater\tis\tpresent\tin\tthe\tatmosphere.  (i)\t\tcomplete\t the\tdot\u2011and\u2011cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\ta\tmolecule\tof\t water.  [2]  (ii)\t\tanhydrous\t copper( ii)\tsulfate\tis\tused\tto\ttest\tfor\twater. \t \tstate\tthe\tcolour\tchange\tin\tthis\ttest. \t from\t.\tto\t \t   [2] \t [total:\t11]",
            "11": "11 0620/32/m/j/21 \u00a9 ucles 2021 [turn over 7 (a)\t\tdilute\tsulfuric\tacid\tis\telectrolysed\tusing\tcarbon\telectrodes. \t\tstate\tthe\tproducts\tof\tthis\telectrolysis\tat: \t the\tnegative\telectrode\t \t... \t the\tpositive\telectrode.\t \t  [2]  (b)\t\tgraphite\tis\ta\tform\tof\tcarbon.\tgraphite\thas\ta\tgiant\tstructure\twith\tcovalent\tbonds.  (i)\t\tstate\tthe\tmeaning\tof\tthe\tterm\tcovalent bond.  \t .  \t ...   [2]  (ii)\t\tgraphite\tis\ta\tsolid. \t \tdescribe\tthe\tarrangement\tand\tmotion\tof\tthe\tparticles\tin\ta\tsolid. \t arrangement\t \t ...  \t . \t motion\t\t .  \t .  [2]  (c)\t\tgraphite\tis\tone\tform\tof\tsolid\tcarbon. \t\tname\tone\t other\tform\tof\tsolid\tcarbon.  \t..   [1] \t [total:\t7]",
            "12": "12 0620/32/m/j/21 \u00a9 ucles 2021 8\t\tthis\tquestion\tis\tabout\telements\tin\tthe\tperiodic\t table.  (a)\t\tthe\ttable\tshows\tsome\tproperties\tof\tfive\telements,\t p,\tq,\tr,\ts\tand\tt. elementmelting\tpoint / \u00b0cdensity in\tg\t/\tcm3electrical\tconductivity of\tthe\tsolidatomic\tradius /\tnm p 63 0.86 very\tgood 0.235 q \u20137 3.12 does\tnot\tconduct 0.114 r 839 1.54 very\tgood 0.174 s 1495 8.9 very\tgood 0.126 t \u2013157 0.0035 does\tnot\tconduct 0.110 \t\tuse\tonly\tthe\telements\tshown\tin\tthe\ttable\tto\tanswer\tthis\tquestion. \t\tstate\twhich\ttwo\tof\tthe\telements,\tp,\tq,\tr,\ts\tand\tt,\tare\tcovalent\tmolecules. \t\tgive\ttwo\treasons\tfor\tyour\tanswer. \t elements\t...\tand\t \t. \t reason\t1\t\t . \t reason\t2\t\t .  [3]  (b)\t\tdescribe\thow\tthe\tmetallic\tcharacter\t of\tthe\telements\tdepends\ton\ttheir\tposition\tin\tthe\tperiodic\t table.  \t  \t..   [1]  (c)\t\tpotassium\tis\tan\telement\tin\tgroup\ti\tof\tthe\tperiodic\t table.\tcobalt\tis\ta\ttransition\telement. \t\tcobalt\thas\ta\thigher\tdensity\tthan\tpotassium. \t\tgive\t two\tother\tways\tin\twhich\tthe\tproperties\t of\ttransition\telements\tdiffer\tfrom\tthe\tproperties\t of\t group\ti\telements.  1 \t.  2 \t.  [2]  (d)\t\tstate\twhether\tpotassium\toxide\tis\ta\tbasic\toxide\tor\tan\tacidic\toxide. \t\tgive\ta\treason\tfor\tyour\tanswer.  \t..   [1]",
            "13": "13 0620/32/m/j/21 \u00a9 ucles 2021 [turn over  (e)\t\tthe\ttable\tcompares\tthe\tease\tof\treduction\tof\tfour\tmetal\toxides\twhen\theated\twith\tcarbon. metal\toxide details\tof\treduction chromium( iii)\toxide reduced\tat\t1200\t \u00b0c manganese( iv)\toxide reduced\tat\t1400\t \u00b0c potassium\toxide not\treduced\tat\t1400\t \u00b0c zinc\toxide reduced\tat\t850\t \u00b0c \t\tput\tthe\tfour\tmetals\tin\torder\tof\ttheir\treactivity. \t\tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]  (f)\t\tdescribe\thow\taqueous\tsodium\thydroxide\tis\tused\tto \ttest\tfor\tchromium( iii)\tions,\tcr3+.  \t  \t  \t..   [2] \t [total:\t11]",
            "14": "14 0620/32/m/j/21 \u00a9 ucles 2021blank page",
            "15": "15 0620/32/m/j/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "16": "16 0620/32/m/j/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s21_qp_33.pdf": {
            "1": "*3314512485* chemistry  0620/33 paper 3 theory (core) may/june 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 06_0620_33/3rp \u00a9 ucles 2021 [turn overthis document has 16 pages.cambridge igcse\u2122",
            "2": "2 0620/33/m/j/21 \u00a9 ucles 2021 1 (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td\tand\te,\tare\tshown. a b c d e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\telectronic\tstructures. \t\teach\telectronic\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\tstate\twhich\telectronic\tstructure,\t a,\tb,\tc,\td or e,\trepresents:  (i)\t\tan\tatom\tof\tan\telement\tin\tgroup\tvi\tof\tthe\tperiodic\t table  \t ...   [1]  (ii)\t\tan\tatom\tof\ta\treactive\tmetal  \t ...   [1]  (iii)\t\tan\tatom\twith\ta\tproton\tnumber\tof\t17  \t ...   [1]  (iv)\t\tan\tatom\tthat\tforms\ta\tstable\tion\twith\ta\tcharge\tof\t2\u2013  \t ...   [1]  (v)\t\tan\tatom\tof\toxygen.  \t ...   [1]  (b)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\tthe\tbromine\tatom\t and\tfluoride\tion\tshown. number\tof electronsnumber\tof neutronsnumber\tof protons 81br35 35 19f\u2013 9 10  [3] \t [total:\t8]",
            "3": "3 0620/33/m/j/21 \u00a9 ucles 2021 [turn over 2\t\tthe\ttable\tshows\tthe\tmasses\tof\tsome\tof\tthe\tions \tin\t1000\tcm3\tof\tfruit\tjuice. name\tof\tion formula\tof\tionmass\tof\tion\tin\t1000\t cm3 of\tfruit\tjuice\t /\tmg ammonium nh4+6 calcium ca2+73 chloride cl \u2013238 magnesium mg2+77 no3\u201310 phosphate po43\u201320 potassium k+419 na+3 sulfate so42\u201310  (a)\t\tanswer\tthese\tquestions\tusing\tonly\tthe\tinformation\t in\tthe\ttable.  (i)\t\tstate\twhich\tnegative\tion\thas\tthe\thighest\tmass\tin\t1000\t cm3\tof\tfruit\tjuice.  \t ...   [1]  (ii)\t\tgive\tthe\tformulae\tof\tthe\tions\tin\tsodium\t nitrate. \t \tand\t\t ...   [1]  (iii)\t\tcalculate\tthe\tmass\tof\tammonium\tions\tin \t250\tcm3\tof\tfruit\tjuice. \t mass\t=\t..\tmg\t\t[1]  (b)\t\tdescribe\ta\ttest\tfor\tchloride\tions.  test \t. \t observations\t \t.. \t [2]  (c)\t\tphosphate\tions,\tpo43\u2013,\tare\tpresent\tin\tmost\tfertilisers.\tphosphate\tions\tcontain\tphosphorus.  (i)\t\tstate\tthe\tnames\tof\ttwo\tother\telements\tthat\tare\tin\tmost\tfertilisers.  1 \t .. \t 2\t\t .. \t [2]",
            "4": "4 0620/33/m/j/21 \u00a9 ucles 2021  (ii)\t\texplain\twhy\tfarmers\tput\tfertilisers\ton\tfields\twhere\tcrops\tare\tto\tbe\tgrown.  \t .  \t ...   [1]  (d)\t\ta\tstudent\theated\tammonium\tsulfate\twith\tsodium\thydroxide\tin\ta\ttest-tube.  (i)\t\tcomplete\tthe\tequation\tfor\tthis\treaction.  (nh4)2so4\t\t+\t\t.naoh\t\t \u2192\t\t.nh3\t\t+\t\tna2so4\t\t+\t\t2h2o\t [2]  (ii)\t\tconcentrated\taqueous\tammonia\treleases\tfumes\tof\tammonia\tgas. \t \ta\tlong\tglass\ttube\tis\tset\tup\tas\tshown. long glass tube cotton wool soaked in concentrated aqueous ammoniadamp red litmus paper \t \tat\tfirst,\tthe\tred\tlitmus\tpaper\tdoes\tnot\tturn\tblue. \t \tafter\ta\tshort\ttime,\tthe\tlitmus\tpaper\tturns\tblue. \t \texplain\tthese\tobservations\tusing\tthe\tkinetic\tparticle\tmodel.  \t .  \t .  \t .  \t .  \t ...   [3] \t [total:\t13]",
            "5": "5 0620/33/m/j/21 \u00a9 ucles 2021 [turn over 3\t\tthe\ttable\tshows\tsome\tproperties\tof\tfive\thalogens. elementmelting\tpoint / \u00b0cboiling\tpoint / \u00b0cdensity\tof\tliquid\tat\t boiling\tpoint\tin\tg\t /\tcm3 colour fluorine \u2013220 \u2013188 yellow chlorine \u201335 1.56 light\tgreen bromine \u20137 59 3.12 red-brown iodine 114 184 4.93 dark\tgrey astatine 302 337 6.35  (a) (i)\t\tcomplete\tthe\ttable\tby\tpredicting:  \u25cf\tthe\tmelting\tpoint\tof\tchlorine  \u25cf\tthe\tdensity\tof\tliquid\tfluorine\tat\tits\tboiling\tpoint  \u25cfthe\tcolour\tof\tastatine.  [3]  (ii)\t\tdeduce\tthe \tstate\tof\tbromine\tat\t0\t \u00b0c. \t \texplain\tyour\tanswer.  \t .  \t .  \t ... \t\t[2]  (b)\t\tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\ta\tmolecule\t of\t chlorine. \t\tshow\tthe\touter\tshell\telectrons\tonly. \t [2]",
            "6": "6 0620/33/m/j/21 \u00a9 ucles 2021  (c) (i)\t\tastatine\tis\ta\tradioactive\telement. \t \tan\tisotope\tof\tastatine,\t217at85,\tdecays\tto\tform\tan\tisotope\tof\tbismuth,\t213bi83. \t \tdescribe\twhat\thappens\tto\tthe\tnumber\tof\tnucleons\tduring\tthis\tdecay.  \t ...   [1]  (ii)\t\tone\tof\tthese\tstatements\tabout\tisotopes \tis\tincorrect. \t \ttick\tthe\tbox\twith\tthe\tincorrect\tstatement. \t \tthe\tisotope\t235u\tis\ta\tsource\tof\tenergy. \t \tsome\tradioactive\tisotopes\tcan\tbe\tused\tto\ttreat\tcancer. \t \tall\tisotopes\tare\tradioactive. \t \tisotopes\tof\tthe\tsame\telement\thave\tthe\tsame\tnumber\tof\tprotons.  [1] \t [total:\t9]",
            "7": "7 0620/33/m/j/21 \u00a9 ucles 2021 [turn over 4 (a)\t\tthe\tstructure\tof\ttwo\torganic\tcompounds,\t f\tand\tg,\tare\tshown. c cc c cccch h hh hh h hf h h h h hh h h hh h hhh hhc cc c ccccg  (i)\t\tcompound \tf\tis\tan\tunsaturated\tcompound. \t \tdescribe\ta\tchemical\ttest\tfor\tan\tunsaturated\tcompound.  test \t .. \t observations\t \t ... \t [2]  (ii)\t\tcompound \tf\tis\treduced\tto\tcompound\t g\tusing\thydrogen\tand\ta\tcatalyst. \t \tstate\twhat\tis\tmeant\tby\tthe\tterm\tcatalyst.  \t .  \t ...   [1]  (iii)\t\tcompound \tg\tis\ta\tsaturated\thydrocarbon. \t \tname\tthe\tsaturated\thydrocarbon\twhich\t contains\ttwo\tcarbon\tatoms.  \t ...   [1]  (b)\t\tcompound\t g\tis\toxidised\tby\tnitric\tacid\tto\tcompound\t h. \t\tthe\tstructure\tof\tcompound\th\tis\tshown. ch hch hch hch hh ch hcc ch ho oho oh  (i)\t\tdeduce\tthe\tformula\tof\tcompound\t h\tto\tshow\tthe\tnumber\tof\tcarbon,\thydrogen\t and\toxygen\t atoms.  \t ...   [1]",
            "8": "8 0620/33/m/j/21 \u00a9 ucles 2021  (ii)\t\tcompound \th\tcontains\ttwo\tcarboxylic\tacid\tfunctional\tgroups. \t \tethanoic\tacid\talso\tcontains\ta\tcarboxylic \tacid\tfunctional\tgroup. \t \tdraw\tthe\tstructure\tof\tethanoic\tacid.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds.  [1]  (iii)\t\tdescribe\tthe\tobservations\tmade\twhen\tethanoic\tacid\treacts\twith: \t universal\tindicator\tsolution\t \t . \t sodium.\t\t ... \t [2]  (c)\t\ta\tstudent\u2019s\tgraph\tof\thow\tthe\tph\tchanges\twhen\taqueous\tammonia\t is\tadded\tslowly\tto\tdilute\t ethanoic\tacid\tis\tshown. 12 10 8 6 4 2 0 0 10 20 volume of aqueous ammonia added  / cm330 40ph",
            "9": "9 0620/33/m/j/21 \u00a9 ucles 2021 [turn over  (i)\t\tdeduce\tthe \tph\tof\tthe\tdilute\tethanoic\tacid\tbefore\tthe\taddition\tof\taqueous\tammonia. \t ph\t=\t..\t\t[1]  (ii)\t\tdeduce\tthe \tvolume\tof\taqueous\tammonia\tadded\twhen\tthe\tph\tis\tneutral. \t ..\tcm3  [1]  (d)\t\tcompound\t h\treacts\twith\tcompound\t j\tto\tform\ta\tpolymer. \t\tcompound\t j\thas\tthe\tformula\thoch2ch2oh.  (i)\t\tstate\tthe\tname\tof\tthe\t\u2013oh\tfunctional\tgroup\tin\tcompound\t j.  \t ...   [1]  (ii)\t\tethene\tpolymerises\tto\tform\tpoly(ethene).   choose one\tword\tfrom\tthe\tlist\tthat\tbest\tdescribes\tthe\ttype\tof\treaction\tthat\toccurs. \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer.  addition          combustion          cracking          reduction  [1] \t [total:\t12]",
            "10": "10 0620/33/m/j/21 \u00a9 ucles 2021 5 (a)\t\tcement\tis\tmade\tby\theating\ta\tmixture\tof\tcalcium\tcarbonate\tand\tpowdered\tclay.  (i)\t\tchoose\tfrom\tthe\tlist\tthe\tname\tof\tthe\tsubstance\twhich\tcontains\tcalcium\tcarbonate. \t \tdraw\ta\tcircle\taround\tthe\tcorrect\tanswer.  bauxite          hematite          limestone          slaked lime  [1]  (ii)\t\tthe\theat\tfor\tthis\tprocess\tis\tprovided\tby\t burning\tnatural\tgas. \t \tname\tthe\tmain\tconstituent\tof\tnatural\tgas.  \t ...   [1]  (b)\t\tcomplete\tthe\tword\tequation\tfor\tthe\tthermal\tdecomposition\tof\tcalcium\tcarbonate. calcium carbonate +  \t [2]  (c)\t\tcarbon\tdioxide\tis\tproduced\t when\tdilute\thydrochloric\t acid\treacts\twith\tpowdered\t calcium\tcarbonate. caco3\t\t+\t\t2hcl  \u2192\t\tcacl 2  +  co2  +  h2o  (i)\t\tcomplete\t the\tdiagram\tto\tshow\tthe\tapparatus\t used\tto\tinvestigate\t the\tvolume\tof\t carbon\tdioxide\tproduced\tduring\tthis\treaction. waterm \t [2]  (ii)\t\tname\tthe\tpiece\tof\tapparatus\tlabelled\t m\tin\tthe\tdiagram.  \t ...   [1]  (iii)\t\tsuggest\tthe\tname\tof\tanother\tpiece\tof\tapparatus\t that\tcan\tbe\tused\tto\tmeasure\tthe\tvolume\t of\tcarbon\tdioxide\tproduced.  \t ...   [1]",
            "11": "11 0620/33/m/j/21 \u00a9 ucles 2021 [turn over  (iv)\t\tdescribe\tthe\teffect\tof\teach\tof\tthe\tfollowing\ton\tthe\trate\tof\treaction\tof\tdilute\thydrochloric\t acid\t with\tcalcium\tcarbonate.  \u25cf\tlarge\tpieces\tof\tcalcium\tcarbonate\tare\tused\tinstead\tof\tpowdered\tcalcium\tcarbonate. \t all\tother\tconditions\tstay\tthe\tsame.  \t .  \u25cf\tthe\ttemperature\tis\tdecreased. \t \tall\tother\tconditions\tstay\tthe\tsame.  \t . \t [2]  (d)\t\texplain\thow\tcarbon\tdioxide\tcontributes\tto\tclimate\tchange.  \t  \t  \t.. \t\t[2] \t [total:\t12]",
            "12": "12 0620/33/m/j/21 \u00a9 ucles 2021 6\t\tthis\tquestion\tis\tabout\tair.  (a)\t\tstate\tthe\tpercentage\tof\tnitrogen\tin\tclean,\tdry\tair. \t ..\t%\t\t[1]  (b)\t\tclean,\tdry\tair\talso\tcontains\targon.\t argon\tis\tunreactive.  (i)\t\texplain,\tusing\tideas\tabout\telectronic\tstructure,\twhy\targon\tis\tunreactive.  \t .  \t ...   [1]  (ii)\t\tgive\tone\tuse\tof\targon.  \t ...   [1]  (c)\t\tcarbon\tmonoxide\tand\toxides\tof\tnitrogen\tare\tpollutants\tof\tair. \t\tfor\teach\tof\tthese\tpollutants\t state\tthe\tsource\tof\tthe\tpollutant\tand\tan\tadverse\teffect\tof\tthe\t pollutant. \t source\tof\tcarbon\tmonoxide\t \t... \t adverse\teffect\t \t \t source\tof\toxides\tof\tnitrogen\t \t.. \t adverse\teffect\t \t  [4] \t [total:\t7]",
            "13": "13 0620/33/m/j/21 \u00a9 ucles 2021 [turn over 7 \tconcentrated\thydrochloric\tacid\tis\telectrolysed\tusing\tcarbon\telectrodes.  (a)\t\tstate\tthe\tproducts\tof\tthis\telectrolysis\tat: \t the\tnegative\telectrode\t \t... \t the\tpositive\telectrode.\t \t \t [2]  (b)\t\tname\ta\tmetal\tthat\tcan\tbe\tused\tas\tan\tinert\telectrode\tinstead\tof\tcarbon.  \t..   [1]  (c)\t\twhen\tdilute\tsulfuric\tacid\tis\telectrolysed,\toxygen\tis\tproduced\tat\tthe\tpositive\telectrode.  (i)\t\tdescribe\tthe\tseparation\tand\tmotion\tof\tthe\tmolecules\tin\toxygen\tgas. \t separation\t \t ...  \t . \t motion\t\t .  \t . \t [2]  (ii)\t\tdescribe\ta\t test\tfor\toxygen.  test \t .. \t observations\t \t ... \t [2] \t [total:\t7]",
            "14": "14 0620/33/m/j/21 \u00a9 ucles 2021 8\t\tthis\tquestion\tis\tabout\telements\tin\tthe\tperiodic\t table.  (a)\t\tthe\ttable\tshows\tsome\tproperties\tof\tfive\telements,\t p,\tq,\tr,\ts\tand\tt. elementmelting\tpoint / \u00b0cdensity in\tg\t/\tcm3electrical\tconductivity of\tthe\tsolidatomic\tradius /\tnm p 114 4.93 does\tnot\tconduct 0.133 q 1083 8.92 very\tgood 0.117 r 3550 3.51 very\tgood 0.077 s 1495 8.9 very\tgood 0.121 t 248 1.2 does\tnot\tconduct 0.065 \t\tuse\tonly\tthe\telements\tshown\tin\tthe\ttable\tto\tanswer\tthese\tquestions. \t\tstate\twhich\ttwo\tof\tthe\telements,\tp,\tq,\tr,\ts\tand\tt,\thave\tcovalent\tmolecules. \t\tgive\ttwo\treasons\tfor\tyour\tanswer. \t elements\t..\tand\t \t.. \t reason\t1\t\t . \t reason\t2\t\t .  [3]  (b)\t\tdiamond\tis\ta\tform\tof\tsolid\tcarbon.  (i)\t\tdescribe\tthe\tstructure\tand\tbonding\tin\tdiamond.  \t .  \t ... \t\t[2]  (ii)\t\tstate\twhy\tdiamond\tis\tused\tfor\tcutting\ttools.  \t ...   [1]  (iii)\t\tname\tone\t other\tform\tof\tsolid\tcarbon.  \t ...   [1]",
            "15": "15 0620/33/m/j/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (c)\t\tlithium\tis\tan\telement\tin\tgroup\ti\tof\tthe\tperiodic\t table.\tcopper\tis\ta\ttransition\telement. \t\tcopper\thas\ta\thigher\tmelting\tpoint\tand\thigher\tboiling\tpoint\tthan\tlithium. \t\tgive\t two\tother\tways\tin\twhich\tthe\tproperties\t of\ttransition\telements\tdiffer\tfrom\tthe\tproperties\t of\t group\ti\telements.  \t  \t.. \t\t[2]  (d)\t\tstate\twhether\tlithium\toxide\tis\ta\tbasic\toxide\tor\tan\tacidic\toxide. \t\tgive\ta\treason\tfor\tyour\tanswer.  \t..   [1]  (e)\t\tthe\ttable\tcompares\tthe\treactions\tof\tfour\tmetals\twith\tsteam. metal reaction\twith\tsteam copper does\tnot\treact iron reacts\trapidly\tat\t120\t \u00b0c lithium reacts\tvery\trapidly\tat\t120\t \u00b0c nickel only\treacts\tabove\t800\t \u00b0c \t\tput\tthe\tfour\tmetals\tin\torder\tof\ttheir\treactivity. \t\tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive \t [2] \t [total:\t12]",
            "16": "16 0620/33/m/j/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s21_qp_41.pdf": {
            "1": "*0998164444* chemistry  0620/41 paper 4 theory (extended) may/june 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 06_0620_41/3rp \u00a9 ucles 2021 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/41/m/j/21 \u00a9 ucles 2021 1  give the name of the process that is used:  (a)  to produce ammonia from nitrogen   ..   [1]  (b)  to separate nitrogen from liquid air   ..   [1]  (c)  to produce bromine from molten lead( ii) bromide   ..   [1]  (d)  to separate an undissolved solid from an aqueous solution   ..   [1]  (e)  to produce amino acids from proteins   ..   [1]  (f)  to separate a mixture of amino acids.   ..   [1]  [total: 6]",
            "3": "3 0620/41/m/j/21 \u00a9 ucles 2021 [turn over 2  complete the table to:  \u25cf deduce the number of protons, electrons and neutrons in the magnesium atom and copper ion  shown  \u25cf identify the atom or ion represented by the final row. number of protonsnumber of electronsnumber of neutrons 25mg12 12 65cu2+ 29 36 17 18 20  [total: 5]",
            "4": "4 0620/41/m/j/21 \u00a9 ucles 2021 3  potassium reacts with chlorine to form potassium  chloride, kc l.  (a)  write a chemical equation for this reaction.   ..   [2]  (b)  potassium chloride is an ionic compound.   complete the diagram to show the electron arrangement in the outer shells of the ions present  in potassium chloride.   give the charges on both ions. k cl  [3]  (c)  molten potassium chloride undergoes electrolysis.  (i)  state what is meant by the term electrolysis.   .   ...   [2]  (ii)  name the products formed at the positive electrode (anode) and negative electrode  (cathode) when molten potassium chloride undergoes electrolysis.  anode  ..  cathode  ...  [2]  (d)  concentrated aqueous potassium chloride undergoes electrolysis.  (i)  write an ionic half-equation for the reaction at the negative electrode (cathode).   ...   [2]  (ii)  name the product formed at the positive electrode (anode).   ...   [1]  (iii)  name the potassium compound that remains in the solution after electrolysis.   ...   [1]",
            "5": "5 0620/41/m/j/21 \u00a9 ucles 2021 [turn over  (e)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  chlorine, c l 2.   show the outer electrons only. cl cl  [1]  (f)  the melting points and boiling points of chlorine and potassium chloride are shown. melting point / \u00b0cboiling point / \u00b0c chlorine \u2013101 \u201335 potassium chloride 770 1500  (i)  deduce the physical state of chlorine at \u201375 \u00b0c. use the data in the table to explain your  answer.  physical state  ..  explanation  .   .  [2]  (ii)  explain, in terms of structure and bonding, why potassium chloride has a much higher  melting point than chlorine.   your answer should refer to the:  \u25cf types of particle held together by the forces of attraction  \u25cf types of forces of attraction between particles  \u25cf relative strength of the forces of attraction.   .   .   .   .   ...   [3]  [total: 19]",
            "6": "6 0620/41/m/j/21 \u00a9 ucles 2021 4  dinitrogen tetroxide, n2o4, decomposes into nitrogen dioxide, no2. the reaction is reversible. n2o4(g)    2no2(g)  colourless gas brown gas   a gas syringe containing a mixture of dinitrogen tetroxide and nitrogen dioxide gases was sealed  and heated. after reaching equilibrium the mixture was a pale brown colour. end sealed plungermixture of dinitrogen tetroxide and nitrogen dioxide  (a)  state what is meant by the term equilibrium .         ..   [2]  (b)  the plunger of the gas syringe is pushed in. the temperature does not change. the mixture  initially turns darker brown. after a few seconds the mixture turns lighter brown because the  equilibrium shifts to the left. n2o4(g)    2no2(g)  colourless gas brown gas  (i)  explain why the mixture initially turns darker brown.   ...   [1]  (ii)  explain why the position of equilibrium shifts to the left.   ...   [1]  (c)  the forward reaction is endothermic.  (i)  state what happens to the position of equilibrium when the temperature of the mixture is  increased.   ...   [1]  (ii)  state what happens to the rate of the forward reaction and the rate of the backward  reaction when the temperature of the mixture is increased.  rate of the forward reaction  .  rate of the backward reaction  .  [2]  [total: 7]",
            "7": "7 0620/41/m/j/21 \u00a9 ucles 2021 [turn over 5  this question is about salts.  (a)  salts that are insoluble in water are made by precipitation.  \u25cf lead( ii) iodide, pb i2, is insoluble in water.  \u25cf all nitrates are soluble in water.  \u25cf all sodium salts are soluble in water.   you are provided with solid lead( ii) nitrate, pb(no3)2, and solid sodium iodide, na i.   describe how you would make a pure sample of lead( ii) iodide by precipitation.   your answer should include:  \u25cf practical details  \u25cf a chemical equation for the precipitation reaction.                              ..   [5]  (b)  nitrates decompose when heated.  (i)\t\twhen\thydrated\tzinc\tnitrate\tis\theated,\toxygen\tgas\tis\tgiven\toff.   describe a test for oxygen.  test  ..  observations  ...  [2]  (ii)  complete the equation for the decomposition of hydrated zinc nitrate.  2zn(no3)2\u20226h2o  \u2192  .zno  +  .no2  +  o2  +  .h2o [2]",
            "8": "8 0620/41/m/j/21 \u00a9 ucles 2021  (c)  some sulfates are hydrated.   when hydrated sodium sulfate crystals, na2so4\u2022xh2o,\tare\theated,\tthey\tgive\toff\twater. na2so4\u2022xh2o(s)  \u2192  na2so4(s)  +  xh2o(g)   a student carries out an experiment to determine the value of x in na2so4\u2022xh2o.  step 1  hydrated sodium sulfate crystals are weighed.  step 2  the hydrated sodium sulfate crystals are then heated.  step 3  the remaining solid is weighed.  (i)\t\tdescribe\thow\tthe\tstudent\tcan\tcheck\tthat\tall\tthe\twater\thas\tbeen\tgiven\toff.   .   .   ...   [2]",
            "9": "9 0620/41/m/j/21 \u00a9 ucles 2021 [turn over  (ii)  in an experiment, 1.61 g of na2so4\u2022xh2o\tis\theated\tuntil\tall\tthe\twater\tis\tgiven\toff.\tthe\t mass of na2so4 remaining is 0.71 g.  [mr:  na2so4,142;  h2o,18]   determine the value of x using the following steps.  \u25cf calculate the number of moles of na2so4 remaining.  .. mol  \u25cf calculate the mass of h2o given off.  .. g  \u25cf calculate the number of moles of h2o given off.  .. mol  \u25cf determine the value of x.  x = ..  [4]  [total: 15]",
            "10": "10 0620/41/m/j/21 \u00a9 ucles 2021 6  this question is about iron.  (a)  iron is extracted from its main ore in a blast furnace. waste gases raw materials : coke, iron ore, limeston e molten irona b  (i)  name the main ore of iron used in the blast furnace.   ...   [1]  (ii)  name the substance that enters the blast furnace at a.   ...   [1]  (iii)  name the substance that leaves the blast furnace at b.   ...   [1]  (iv)  give two reasons for using coke in the blast furnace.  1  ..  2  ..  [2]  (b)  another ore of iron is iron pyrites, fes2. iron pyrites contains the positive ion, fe2+.   deduce the formula of the negative ion in fes2.   ..   [1]",
            "11": "11 0620/41/m/j/21 \u00a9 ucles 2021 [turn over  (c)  iron is a transition element.   a list of properties of iron is shown.  \u25cf iron is a good conductor of electricity.  \u25cf iron forms soluble salts.  \u25cf iron forms coloured compounds.  \u25cf iron has variable oxidation states.  \u25cf iron acts as a catalyst.  \u25cf iron forms a basic oxide.  (i)  give two\tproperties\tfrom\tthe\tlist\tin\twhich\tiron\tdiffers\tfrom\tgroup\ti\telements.  1  ..  2  ..  [2]  (ii)  give two properties from the list in which iron is similar to group i elements.  1  ..  2  ..  [2]  (d)  steel consists mainly of iron.   iron forms rust when it reacts with water and oxygen.   magnesium blocks can be attached to the bottom of steel boats. the magnesium does not  completely cover the steel. water containing dissolved oxygenmagnesium blockssteel boat  (i)  explain how the magnesium blocks prevent iron from rusting.   .   .   .   ...   [2]",
            "12": "12 0620/41/m/j/21 \u00a9 ucles 2021  (ii)  explain why replacing the magnesium blocks with copper blocks will not prevent the  bottom of the boat from rusting.   .   ...   [1]  [total: 13]",
            "13": "13 0620/41/m/j/21 \u00a9 ucles 2021 [turn over 7  many organic compounds contain carbon, hydrogen and oxygen only.  (a)  an organic compound v has the following composition by mass. c, 48.65%;  h, 8.11%;  o, 43.24%   calculate the empirical formula of compound v.  empirical formula = ..  [3]  (b)  compound w has the empirical formula ch4o and a relative molecular mass of 32.   calculate the molecular formula of compound w.  molecular formula = ..  [1]  (c)  compounds x and y have the same general formula.   x and y are both carboxylic acids.   compound x has the molecular formula c2h4o2.   compound y has the molecular formula c4h8o2.  (i)  deduce the general formula of compounds x and y.   ...   [1]",
            "14": "14 0620/41/m/j/21 \u00a9 ucles 2021  (ii)  draw the structure of compound y. show all of the atoms and all of the bonds.   name compound y.  name  ...  [3]  (iii)  give the name used to describe a \u2018family\u2019 of similar compounds with the same general  formula, similar chemical properties and the same functional group.   ...   [1]  (d)  propene is an unsaturated hydrocarbon. the formula of propene is shown. ch3ch=ch2  (i)  state the colour change observed when propene is added to aqueous bromine.  from . to     [1]  (ii)  propene can be produced by cracking long chain alkanes.   pentadecane, c15h32, is cracked to produce an alkane and propene in a 1  : 2 molar ratio.   complete the chemical equation for this reaction.  c15h32  \u2192  ...  +  ... [2]  (iii)  propene can be converted into poly(propene).   name the type of polymerisation that occurs when propene is converted into poly(propene).   ...   [1]  (iv)  complete the diagram to show a section of poly(propene). c c c c  [2]  [total: 15]",
            "15": "15 0620/41/m/j/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.blank page",
            "16": "16 0620/41/m/j/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s21_qp_42.pdf": {
            "1": "*9904169354* chemistry  0620/42 paper 4 theory (extended) may/june 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 06_0620_42/2rp \u00a9 ucles 2021 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/42/m/j/21 \u00a9 ucles 2021 1  the symbols of the elements of period 3 of the periodic table are shown. na mg al si p s cl ar   answer the following questions about these elements.   each element may be used once, more than once or not at all.   write the symbol of an element which:  (a)  is malleable   ..   [1]  (b)  has only two electrons in its outermost shell   ..   [1]  (c)  forms an oxide which leads to acid rain   ..   [1]  (d)  forms an ion with a 2\u2013 charge   ..   [1]  (e)  is extracted from an ore called bauxite   ..   [1]  (f)  does not form an oxide   ..   [1]  (g)  forms an oxide with a macromolecular structure   ..   [1]  (h)  forms an amphoteric oxide   ..   [1]  (i)  exists as diatomic molecules   ..   [1]  (j)  forms a binary compound with hydrogen that is a strong acid.   ..   [1]  [total: 10]",
            "3": "3 0620/42/m/j/21 \u00a9 ucles 2021 [turn over 2  silver has an atomic number of 47.  (a)  naturally occurring atoms of silver are 107ag and 109ag.  (i)\t\tstate\tthe\tname\tgiven\tto\tatoms\tof\tthe\tsame\telement\twith\tdifferent\tnucleon\tnumbers.   ...   [1]  (ii)  complete the table to show the number of protons, neutrons and electrons in each atom  and ion of silver shown. 107ag47109ag+ 47 protons neutrons electrons  [3]  (iii)\t\tcomplete\tthis\tdefinition\tof\trelative\tatomic\tmass.   relative atomic mass is the ... mass of naturally occurring atoms     of an element on a scale where the ... atom has a mass of exactly     ... units.  [3]  (iv)  a sample of silver has a relative atomic mass of 108.0.   deduce the percentage of 107ag present in this sample of silver.   ...   [1]  (b)  silver nitrate is a salt of silver made by reacting silver oxide with an acid.   write the formula of the acid which reacts with silver oxide to form silver nitrate.   ..   [1]",
            "4": "4 0620/42/m/j/21 \u00a9 ucles 2021  (c)  aqueous silver nitrate is a colourless solution containing ag+(aq) ions.  (i)  describe what is seen when aqueous silver nitrate is added to aqueous sodium iodide,  nai(aq).   ...   [1]  (ii)  write the ionic equation for the reaction between aqueous silver nitrate and aqueous  sodium iodide.   include state symbols.   ...   [3]  (d)  in the positive test for aqueous nitrate ions, aqueous sodium hydroxide and one other substance  are warmed with the nitrate ions.   name this other substance and the gas formed.  name of substance    name of gas  ...  [2]  (e)  when silver nitrate is exposed to sunlight, silver is formed.   name the type of reaction which needs light to make it happen.   ..   [1]  (f)  members of one homologous series only react with chlorine in the presence of sunlight.  (i)  name a member of this homologous series.   ...   [1]  (ii)  name two products that form when the compound in (i) reacts with chlorine.  1  ..  2  ..  [2]  [total: 19]",
            "5": "5 0620/42/m/j/21 \u00a9 ucles 2021 [turn over 3  sodium hydrogencarbonate is found in baking powder.   when sodium hydrogencarbonate is heated it forms three products. 2nahco3  \u2192  na2co3  +  h2o  +  co2  (a)  name the type of reaction that takes place when sodium hydrogencarbonate reacts in this way.   ..   [1]  (b)  calculate the volume of carbon dioxide formed at room temperature and pressure when 12.6 g  of nahco3 is heated using the following steps:  \u25cf determine the mass of one mole of nahco3  .. g  \u25cf calculate the number of moles of nahco3 used  .. moles  \u25cf determine the number of moles of carbon dioxide formed  .. moles  \u25cf calculate the volume of carbon dioxide formed at room temperature and pressure.  .. dm3  [4]  (c)  limewater is aqueous calcium hydroxide. carbon dioxide turns limewater milky because a  white precipitate forms.   write the formula of:  \u25cf calcium hydroxide  ...  \u25cf the white precipitate that forms when limewater turns milky.  ..  [2]  [total: 7]",
            "6": "6 0620/42/m/j/21 \u00a9 ucles 2021 4  a student carries out an electrolysis experiment using the apparatus shown. +\u2013 carbon electrode swire dilute aqueous sodium chloride   the student uses dilute aqueous sodium chloride.  (a)  state the name given to any solution which undergoes electrolysis.   ..   [1]  (b)  hydroxide ions are discharged at the anode.  (i)  complete the ionic half-equation for this reaction.  ..oh\u2013(aq)  \u2192  ...  +  o2(g)  +  4e\u2013 [2]  (ii)  explain how the ionic half-equation shows the hydroxide ions are being oxidised.   ...   [1]  (c)  describe what the student observes at the cathode.   ..   [1]  (d)  write the ionic half-equation for the reaction at the cathode.   ..   [2]",
            "7": "7 0620/42/m/j/21 \u00a9 ucles 2021 [turn over  (e)  the student repeats the experiment using concentrated aqueous sodium chloride.  (i)  describe what the student observes at:  \u25cf the cathode  ..  \u25cf the anode.    [2]  (ii)  the student added litmus to the solution after the electrolysis of concentrated aqueous  sodium chloride.   state the colour seen in the solution. give a reason for your answer.  colour of solution    reason  .  [2]  (f)  carbon electrodes are used because they are inert.   state another element that can be used instead of carbon.   ..   [1]  [total: 12]",
            "8": "8 0620/42/m/j/21 \u00a9 ucles 2021 5  this question is about compounds of nitrogen.  (a)  nitrogen reacts with lithium to form lithium nitride, li3n.  (i)  write the chemical equation for the reaction between lithium and nitrogen.   ...   [2]  (ii)  lithium nitride is ionically bonded.   complete the diagram to show the electronic structure of the nitride ion.   show the charge on the nitride ion. n  [2]",
            "9": "9 0620/42/m/j/21 \u00a9 ucles 2021 [turn over  (b)\t\tnitrogen\treacts\twith\tfluorine\tto\tform\tnitrogen\ttrifluoride,\tnf3.  (i)  the chemical equation can be represented as shown. n\u2261n  +  3 f\u2013f  /g111  2 f\u2013n\u2013f f   some bond energies are shown in the table. bond bond energy in kj / mol n\u2261n 945 f\u2013f 160 n\u2013f 300 \t \tcalculate\t the\tenergy\tchange\tfor\tthe\treaction\t between\t nitrogen\t and\tfluorine,\t using\tthe\t following steps:  \u25cf energy taken in to break bonds  .. kj  \u25cf energy released when bonds are formed  .. kj  \u25cf energy change during the reaction.  .. kj / mol  [3]  (ii)  use your answer to (i) to deduce whether this reaction is endothermic or exothermic.  explain your answer.   .   ...   [1]",
            "10": "10 0620/42/m/j/21 \u00a9 ucles 2021  (iii)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  nf3.  \t \tuse\tdots\tfor\tnitrogen\telectrons\tand\tcrosses\tfor\tfluorine\telectrons.   show outer electrons only. ff f n  [3]  (c)  lithium nitride melts at 813 \u00b0c.\tnitrogen\ttrifluoride\tmelts\tat\t\u2013206\t \u00b0c.   explain in terms of attractive forces why lithium nitride has a much higher melting point than  nitrogen\ttrifluoride.   in your answer refer to the types of attractive forces between particles and their relative  strengths.            ..   [3]  (d)  ammonium nitrate, nh4no3, is a compound of nitrogen.  (i)  calculate the percentage by mass of nitrogen in ammonium nitrate.  percentage by mass of nitrogen = ..  [2]  (ii)  state a use of ammonium nitrate in agriculture.   ...   [1]  (iii)  state the name of a compound that will displace ammonia from ammonium nitrate.   ...   [1]",
            "11": "11 0620/42/m/j/21 \u00a9 ucles 2021 [turn over  (e)  ammonia is a base which forms a weakly alkaline solution when dissolved in water.  (i)\t\tdefine\tthe\tterm\tbase.   ...   [1]  (ii)  suggest the ph of aqueous ammonia.   ...   [1]  [total: 20]",
            "12": "12 0620/42/m/j/21 \u00a9 ucles 2021 6  molecules a and b can form condensation polymers. a ho ohb hooc cooh  (a)  each molecule has two identical functional groups.  (i)  name the functional group in b.   ...   [1]  (ii)  draw the part of the structure of the synthetic polymer that would form when two molecules  of a and two molecules of b combine. show all of the bonds in the linkages.  [3]  (iii)  name the other product formed when molecules of a and b undergo polymerisation.   ...   [1]  (b)  molecule a is a simple sugar unit which can be made by hydrolysis of complex carbohydrates.  (i)  draw part of the complex carbohydrate that could be hydrolysed to make molecules of a.   include one linkage and show all of the bonds in the linkage.  [1]  (ii)  state two sets of conditions which could be used to hydrolyse the complex carbohydrate  to form a.  1  ..  2  ..  [2]  (iii)  name the technique used to identify the individual sugar units made by the hydrolysis of a  complex carbohydrate.   ...   [1]",
            "13": "13 0620/42/m/j/21 \u00a9 ucles 2021 [turn over  (c)  ethanol can be made from the simple sugar glucose, c6h12o6.  (i)  state the name of this process.   ...   [1]  (ii)  complete the chemical equation for this reaction.  c6h12o6  \u2192 [2]  [total: 12]",
            "14": "14 0620/42/m/j/21 \u00a9 ucles 2021blank page",
            "15": "15 0620/42/m/j/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/42/m/j/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s21_qp_43.pdf": {
            "1": "*8479859252* chemistry  0620/43 paper 4 theory (extended) may/june 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 06_0620_43/3rp \u00a9 ucles 2021 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/43/m/j/21 \u00a9 ucles 2021 1  give the name of the process that is used:  (a)  to produce large molecules from monomers   ..   [1]  (b)  to separate oxygen from liquid air   ..   [1]  (c)  to make ethanol from glucose   ..   [1]  (d)  to separate water from aqueous sodium chloride   ..   [1]  (e)  to produce aluminium from aluminium oxide in molten cryolite   ..   [1]  (f)  to separate the products of hydrolysis of long chain carbohydrates   ..   [1]  (g)  to separate an aqueous solution from an undissolved solid.   ..   [1]  [total: 7]",
            "3": "3 0620/43/m/j/21 \u00a9 ucles 2021 [turn over 2  complete the table to:  \u25cf deduce the number of protons, electrons and neutrons in the boron atom and chloride ion  shown  \u25cf identify the atom or ion represented by the final row. formulanumber of protonsnumber of electronsnumber of neutrons 11b5 5 35cl \u2013 17 17 24 21 30  [total: 5]",
            "4": "4 0620/43/m/j/21 \u00a9 ucles 2021 3\t\tsodium\treacts\twith\tfluorine\tto\tform\tsodium\tfluoride,\tnaf.  (a)  write a chemical equation for this reaction.   ..   [2]  (b)\t\tsodium\tfluoride\tis\tan\tionic\tcompound.   complete the diagram to show the electron arrangement in the outer shells of the ions present  in\tsodium\tfluoride.   give the charges on both ions. na f  [3]  (c)\t\taqueous\tsodium\tfluoride\tundergoes\telectrolysis.  (i)  state what is meant by the term electrolysis.   .   ...   [2]  (ii)\t\tname\tthe\tproducts\t formed\tat\tthe\tpositive\telectrode\t (anode)\t and\tthe\tnegative\t electrode\t (cathode)\twhen\tdilute\taqueous\tsodium\tfluoride\tundergoes\telectrolysis.  anode  ..  cathode  ...  [2]  (d)\t\tmolten\tsodium\tfluoride\tundergoes\telectrolysis.  (i)\t\tname\tthe\tproducts\t formed\tat\tthe\tpositive\telectrode\t (anode)\t and\tthe\tnegative\t electrode\t (cathode)\twhen\tmolten\tsodium\tfluoride\tundergoes\telectrolysis.  anode  ..  cathode  ...  [2]  (ii)\t\twrite\tthe\tionic\thalf-equation\tfor\tthe\treaction\tat\tthe\tnegative\telectrode\t(cathode).   ...   [1]",
            "5": "5 0620/43/m/j/21 \u00a9 ucles 2021 [turn over  (e)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  fluorine,\tf2.   show the outer electrons only. ff  [1]  (f)\t\tthe\tmelting\tpoints\tand\tboiling\tpoints\tof\tfluorine\tand \tsodium\tfluoride\tare\tshown. melting point / \u00b0cboiling point / \u00b0c fluorine \u2013220 \u2013188 sodium\tfluoride 993 1695  (i)\t\tdeduce\tthe\tphysical\t state\tof\tfluorine\tat\t\u2013195\t\u00b0c. use the data in the table to explain your  answer.  physical state  ..  explanation  .   .  [2]  (ii)\t\texplain,\t in\tterms\tof\tstructure\t and\tbonding,\t why\tsodium\tfluoride\thas\ta\tmuch\thigher\tmelting\t point\tthan\tfluorine.   your answer should refer to the:  \u25cf types of particle held together by the forces of attraction  \u25cf types of forces of attraction between particles  \u25cf relative strength of the forces of attraction.   .   .   .   ...   [3]  [total: 18]",
            "6": "6 0620/43/m/j/21 \u00a9 ucles 2021 4  hydrogen iodide, h i, decomposes into iodine and hydrogen. the reaction is reversible. 2hi(g)\t\t\t\t\t\t       i2(g)\t\t\t\t\t\t+\t\t\t\t\t\th2(g)  colourless gas purple gas colourless gas   a gas syringe containing a mixture of hydrogen iodide, iodine and hydrogen gases was sealed.  after reaching equilibrium the mixture was a pale purple colour. end sealed plungerequilibrium mixture of hydrogen iodide, iodine and hydroge n  (a)  state what is meant by the term equilibrium .         ..   [2]  (b)  the plunger of the gas syringe is pushed in. the position of equilibrium does not change. the  colour of the gaseous mixture turns darker purple.   the temperature remains constant. 2hi(g)\t\t\t\t\t\t       i2(g)\t\t\t\t\t\t+\t\t\t\t\t\th2(g)  colourless gas purple gas colourless gas  (i)  explain why the position of equilibrium does not change.   ...   [1]  (ii)  suggest why the colour of the gaseous mixture turns darker purple even though the  position of equilibrium does not change.   ...   [1]  (c)  the forward reaction is endothermic.  (i)  state what happens to the position of equilibrium when the temperature is decreased.   .   ...   [1]",
            "7": "7 0620/43/m/j/21 \u00a9 ucles 2021 [turn over  (ii)  state what happens to the rate of the forward reaction and the rate of the backward  reaction when the temperature of the mixture is decreased.  rate of the forward reaction  .  rate of the backward reaction  .  [2]  [total: 7]",
            "8": "8 0620/43/m/j/21 \u00a9 ucles 2021 5  this question is about salts.  (a)  salts that are soluble in water can be made by the reaction between insoluble carbonates and  dilute acids. zinc sulfate is soluble in water.   you are provided with solid zinc carbonate, znco3, and dilute sulfuric acid, h2so4.   describe how you would make a pure sample of zinc sulfate crystals.   your answer should include:  \u25cf practical details  \u25cf how you would make sure that all the dilute sulfuric acid has reacted  \u25cf a chemical equation for the reaction.                                 ..   [5]  (b)  some sulfates decompose when heated. \t \twhen\thydrated\tiron( ii)\tsulfate\tis\theated\tstrongly,\tsulfur\tdioxide\tgas\tis\tgiven\toff.  (i)  describe a test for sulfur dioxide.  test  ..  observations  ...  [2]  (ii)\t\tcomplete\tthe\tequation\tfor\tthe\tdecomposition\tof\thydrated\tiron( ii)\tsulfate. \t .feso4\u20227h2o  \u2192\t\tfe2o3\t\t+\t\tso2\t\t+\t\tso3\t\t+\t\t.h2o [2]",
            "9": "9 0620/43/m/j/21 \u00a9 ucles 2021 [turn over  (c)  some chlorides are hydrated.   when hydrated barium chloride crystals, bac l 2\u2022xh2o,\tare\theated\tthey\tgive\toff\twater. bacl 2\u2022xh2o(s)\t\t\u2192  bacl 2(s)\t\t+\t\t xh2o(g)   a student carries out an experiment to determine the value of x in bacl 2\u2022xh2o.  step 1  hydrated barium chloride crystals are weighed.  step 2  the hydrated barium chloride crystals are then heated.  step 3  the remaining solid is weighed.  (i)\t\tdescribe\thow\tthe\tstudent\tcan\tbe\tsure\tthat\tall\tthe\twater\tis\tgiven\toff.   .   .   ...   [2]  (ii)  in an experiment, 4.88 g of bacl 2\u2022xh2o\tis\theated\tuntil\tall\tthe\twater\tis\tgiven\toff.\tthe\tmass\t of bacl 2 remaining is 4.16 g.  [mr:  bacl 2, 208;  h2o, 18]   determine the value of x using the following steps.  \u25cf calculate the number of moles of bac l 2 remaining.  .. mol  \u25cf calculate the mass of h2o given off.  .. g  \u25cf calculate the number of moles of h2o given off.  .. mol  \u25cf determine the value of x.  x = ..  [4]  [total: 15]",
            "10": "10 0620/43/m/j/21 \u00a9 ucles 2021 6  this question is about metals.  (a)  iron is extracted from its main ore in a blast furnace. waste gases slagair air a  (i)  coke and iron ore are added at the top of the blast furnace. \t \tname\tone\t other substance that is added at the top of the blast furnace.   ...   [1]  (ii)\t\tname\tthe\tsubstance\tthat\tleaves\tthe\tblast\tfurnace\tat\ta.   ...   [1]  (iii)\t\tiron\tore\tis\tmainly\tiron( iii)\toxide,\tfe2o3. \t \tname\ta\tsubstance\tthat\treduces\tiron( iii)\toxide\tto\tiron\tin\tthe\tblast\tfurnace.   ...   [1]  (iv)  temperatures inside a blast furnace can reach 2000 \u00b0c. \t \tname\t two substances that react together, in the blast furnace, to produce this high  temperature.   ...   [1]  (v)\t\tname\ttwo waste gases that leave the blast furnace.  1  ..  2  ..  [2]",
            "11": "11 0620/43/m/j/21 \u00a9 ucles 2021 [turn over  (b)  zinc is extracted from zinc blende.  (i)\t\tname\tthe\tmain\tzinc\tcompound\tthat\tis\tpresent\tin\tzinc\tblende.   ...   [1]  (ii)  when zinc is extracted, it is formed as a gas.   the gaseous zinc is then converted into molten zinc.   state the name of this physical change.   ...   [1]  (c)\t\tname\tthe\talloy\tthat\tcontains\tzinc\tand\tcopper\tonly.   ..   [1]  (d)  copper has the following properties.  \u25cf it has a high melting point.  \u25cf it has a high density.  \u25cf it is a good conductor of electricity.  \u25cf it has variable oxidation states.  \u25cf it forms a basic oxide.  \u25cf it forms soluble salts.  (i)  give two\tproperties\tfrom\tthe\tlist\tin\twhich\tcopper\tdiffers\tfrom\tgroup\ti\telements.  1  ..  2  ..  [2]  (ii)  give two properties from the list in which copper is similar to group i elements.  1  ..  2  ..  [2]  [total: 13]",
            "12": "12 0620/43/m/j/21 \u00a9 ucles 2021 7  many organic compounds contain carbon, hydrogen and oxygen only.  (a)  an organic compound r has the following composition by mass. c, 69.77%;  h, 11.63%;  o, 18.60%   calculate the empirical formula of compound r.  empirical formula = ..  [2]  (b)  compound s has the empirical formula ch2o and a relative molecular mass of 60.   calculate the molecular formula of compound s.  molecular formula = ..  [2]  (c)  compounds t and v have the same molecular formula, c3h6o2.  \u25cf compound t is an ester.  \u25cf compound v contains a \u2013cooh functional group.  (i)\t\tstate\tthe\tname\tgiven\tto\tcompounds\t with\tthe\tsame\tmolecular\t formula\t but\tdifferent\t structures.   ...   [1]  (ii)\t\tname\tthe\thomologous\tseries\tthat\t v is a member of.   ...   [1]",
            "13": "13 0620/43/m/j/21 \u00a9 ucles 2021 [turn over  (iii)  draw a structure of compound t. show all of the atoms and all of the bonds. \t \tname\tcompound\t t.  name  ...  [3]  (iv)  draw the structure of compound v. show all of the atoms and all of the bonds. \t \tname\tcompound\t v.  name  ...  [2]  (d)  ethanol can be produced from long chain alkanes such as decane, c10h22, in a two-step  process.  step 1 step 2 decane    ethene    ethanol \t \tfor\teach\tof\tthe\ttwo\tsteps:  \u25cf name the type of chemical reaction that occurs  \u25cf write a chemical equation.  step 1: decane to ethene  type of reaction  ..  chemical equation  ..  step 2: ethene to ethanol  type of reaction  ..  chemical equation  ..  [4]  [total: 15]",
            "14": "14 0620/43/m/j/21 \u00a9 ucles 2021blank page",
            "15": "15 0620/43/m/j/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/43/m/j/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s21_qp_51.pdf": {
            "1": "*2816117620* chemistry  0620/51 paper 5 practical test may/june 2021  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib21 06_0620_51/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/51/m/j/21 \u00a9 ucles 2021 1  you are going to investigate the temperature decrease when sodium hydrogencarbonate reacts  with dilute hydrochloric acid.   read all of the instructions carefully before starting the experiments.   instructions   you are going to do six experiments.  (a)  experiment 1  \u25cf use a measuring cylinder to pour 25 cm3 of dilute hydrochloric acid into a conical flask.  \u25cf use a thermometer to measure the initial temperature of the acid. record the initial  temperature in the table.  \u25cf add the 1 g sample of sodium hydrogencarbonate to the conical flask. at the same time  start the stop-clock.  \u25cf continually stir the acid and sodium hydrogencarbonate mixture in the conical flask using  the thermometer.  \u25cf measure the temperature reached by the mixture after 1 minute. record the temperature  of the mixture in the table.  \u25cf calculate and record the temperature decrease in the table.  \u25cf rinse the conical flask with distilled water.  experiment 2  \u25cf repeat experiment 1 using 2 g of sodium hydrogencarbonate instead of 1 g.   experiment 3  \u25cf repeat experiment 1 using 3 g of sodium hydrogencarbonate instead of 1 g.  experiment 4  \u25cf repeat experiment 1 using 5 g of sodium hydrogencarbonate instead of 1 g.  experiment 5  \u25cf repeat experiment 1 using 6 g of sodium hydrogencarbonate instead of 1 g.   experiment 6  \u25cf repeat experiment 1 using 7 g of sodium hydrogencarbonate instead of 1 g. experimentmass of sodium hydrogencarbonate / ginitial temperature / \u00b0ctemperature after 1 minute / \u00b0ctemperature decrease / \u00b0c 1 1 2 2 3 3 4 5 5 6 6 7  [4]",
            "3": "3 0620/51/m/j/21 \u00a9 ucles 2021 [turn over  (b)  complete a suitable scale on the y-axis and plot your results from experiments 1 to 6 on the  grid.   draw two best-fit straight lines through your points. the first straight line should be for the first  three points and must pass through (0,0). the second straight line should be for the last three  points and must be horizontal. extend your straight lines so that they meet each other. temperature decrease  / \u00b0c 00 123 mass of sodium hydrogencarbonate  / g4567  [5]  (c) (i)  from your graph, determine the temperature decrease and mass of sodium  hydrogencarbonate where your two straight lines meet. include appropriate units in your  answer.   show clearly on the grid  how you worked out your answer.   temperature decrease = ..   mass of sodium hydrogencarbonate = ..  [3]  (ii)  explain why the temperature decrease becomes constant for high masses of sodium  hydrogencarbonate.   .   ...   [1]",
            "4": "4 0620/51/m/j/21 \u00a9 ucles 2021  (d)  the investigation could be repeated with dilute hydrochloric acid of half the concentration, but  the same volume.   sketch on the grid  the graph you would expect to obtain.   label your line d. [2]  (e)  suggest two changes that could be made to the apparatus that would improve the accuracy of  the results. for each change explain why it would improve the accuracy of the results.   change 1     explanation 1  .      change 2     explanation 2  .     [4]  [total: 19]",
            "5": "5 0620/51/m/j/21 \u00a9 ucles 2021 [turn over 2  you are provided with one solid, solid e, and one solution, solution f.   do the following tests on the substances, recording all of your observations at each stage.   tests on solid e  (a)  place about half of solid e in a hard-glass test-tube. heat the solid gently for about 30 seconds.    record your observations.         ..   [2]   transfer the remaining solid e to a boiling tube. add about 10 cm3 of distilled water to the boiling  tube.   place a stopper in the boiling tube and shake the tube to dissolve solid e and form solution e.   divide solution e into three approximately equal portions in two test-tubes and one boiling tube.  (b)  to the first portion of solution e in a test-tube, add about 1 cm depth of dilute nitric acid followed  by a few drops of aqueous barium nitrate.   record your observations.   ..   [1]  (c)  to the second portion of solution e in a test-tube, add excess aqueous ammonia.   record your observations.   ..   [1]  (d)  to the third portion of solution e in the boiling tube, add aqueous sodium hydroxide dropwise  and then in excess.   keep the product for use in (e).   record your observations.         ..   [2]  (e)  gently warm the product from (d). test any gas produced.   record your observations.      ..   [1]",
            "6": "6 0620/51/m/j/21 \u00a9 ucles 2021  (f)  identify the three ions contained in solid e.      ..   [3]   tests on solution f  (g)  carry out a flame test on solution f.   record your observations.   ..   [1]  (h)  divide the remaining solution f into two approximately equal portions in two test-tubes.  (i)  to the first portion of solution f add a few drops of universal indicator solution.   record your observations.   .   ...   [1]  (ii)  to the second portion of solution f add approximately 2 cm depth of aqueous  copper( ii) sulfate.   record your observations.   .   ...   [1]  (i)  identify solution f.      ..   [2]  [total: 15]",
            "7": "7 0620/51/m/j/21 \u00a9 ucles 2021 [turn over 3  dilute hydrochloric acid reacts with calcium carbonate to make carbon dioxide gas. the apparatus  shown in the diagram can be used to follow the progress of the reaction. the carbon dioxide gas  leaves the flask causing the mass shown on the balance to decrease. 260.00cotton wool dilute hydrochloric acid balancecalcium carbonate   plan an investigation, using the apparatus shown in the diagram, to find out how the temperature  of the dilute hydrochloric acid affects the rate of the reaction. your plan should include how your  results will show how the temperature of the dilute hydrochloric acid affects the rate of the reaction.   you are provided with dilute hydrochloric acid, calcium carbonate and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/51/m/j/21 \u00a9 ucles 2021blank page",
            "9": "9 0620/51/m/j/21 \u00a9 ucles 2021blank page",
            "10": "10 0620/51/m/j/21 \u00a9 ucles 2021blank page",
            "11": "11 0620/51/m/j/21 \u00a9 ucles 2021notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/51/m/j/21 \u00a9 ucles 2021tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s21_qp_52.pdf": {
            "1": "*9217316557* chemistry  0620/52 paper 5 practical test may/june 2021  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib21 06_0620_52/rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/52/m/j/21 \u00a9 ucles 2021 1  you are going to investigate the volume of gas made when sodium carbonate reacts with  dilute hydrochloric acid.   read all of the instructions carefully before starting the experiments.   instructions \t\tyou\tare\tgoing\tto\tdo\tfive\texperiments\tusing\tthe\tapparatus\tshown. trough waterclamp inverted 100  cm3 measuring cylinder boiling tubebungrubber delivery tube   experiment 1  \u25cf use a 25 cm3\tmeasuring\tcylinder\tto\tpour\t16\t cm3 of dilute hydrochloric acid into a boiling tube.  \u25cf\tset\tup\tthe\tapparatus\t as\tshown\tin\tthe\tdiagram.\t ensure\tthe\tinverted\t measuring\t cylinder\tis\tfull\t of water.  \u25cf remove the bung from the boiling tube.  \u25cf\tadd\ta\t2.5\tg\tsample\tof\tsodium\tcarbonate\t to\tthe\tboiling\ttube\tand\timmediately\t replace\tthe\tbung.  \u25cf\twhen\tthe\tvolume\tof\tgas\tin\tthe\tmeasuring\t cylinder\tstops\tchanging,\t measure\t the\tvolume\tof\tgas\t in the measuring cylinder. record the volume in the table in (a).   experiment 2  \u25cf\trepeat\texperiment\t1\tusing\t14\t cm3\tof\tdilute\thydrochloric\tacid\tinstead\tof\t16\t cm3.   experiment 3  \u25cf\trepeat\texperiment\t2\tusing\t12\t cm3\tof\tdilute\thydrochloric\tacid\tinstead\tof\t14\t cm3.   experiment 4  \u25cf\trepeat\texperiment\t3\tusing\t10\t cm3\tof\tdilute\thydrochloric\tacid\tinstead\tof\t12\tcm3.  \u25cf\tuse\ta\t10\t cm3 measuring cylinder to measure the volume of the acid.   experiment 5  \u25cf\trepeat\texperiment\t4\tusing\t6\t cm3\tof\tdilute\thydrochloric\tacid\tinstead\tof\t10\t cm3.",
            "3": "3 0620/52/m/j/21 \u00a9 ucles 2021 [turn over  (a)\t\tcomplete\tthe\ttable. experimentvolume of dilute hydrochloric acid / cm3volume of gas collected / cm3 1 2 3 4 5 \t [4]  (b)  write a suitable scale on the y-axis\t and\tplot\tyour\tresults\tfrom\texperiments\t 1\tto\t5\ton\tthe\tgrid.\t draw\ta\tstraight\tline\tof\tbest\tfit. 4681 01 2 volume of dilute hydrochloric aci d / cm3volume of gas collecte d / cm3 14 16 \t [4]",
            "4": "4 0620/52/m/j/21 \u00a9 ucles 2021  (c) (i)  from your graph,\t deduce\tthe\tvolume\tof\tgas\tthat\twould\tbe\tcollected\t if\t7\tcm3 of dilute  hydrochloric acid was used.   show clearly on the grid  how you worked out your answer.  .. cm3 \t [2]  (ii)\t\tthe\tvolume\tof\tgas\tmade\tper\tcm3 of dilute hydrochloric acid can be calculated using the  equation shown. volume\tof\tgas\tper\tcm3 of acid =volume of gas collected in cm3 volume of acid in cm3   use this equation and your answer to (c)(i)\t to\tcalculate\t the\tvolume\tof\tgas\tmade\tper\tcm3  of dilute hydrochloric acid. \t ..\t\t[1]  (d)\t\tthe\tbung\tis\tremoved\t and\tthen\treplaced\t immediately\t after\tthe\tsodium\tcarbonate\t is\tadded\tto\t the boiling tube.  (i)\t\texplain\twhy\tthe\tbung\tmust\tbe\treplaced\t immediately\t after\tthe\tsodium\tcarbonate\tis\tadded\t to the boiling tube.   .   ... \t\t[1]  (ii)\t\texplain\thow\tthe\tapparatus\t could\tbe\taltered\tso\tthat\tthe\tbung\tdoes\t not have to be removed.  you\tmay\tdraw\ta\tdiagram\tto\texplain\tyour\tanswer.   .   ... \t\t[2]  (e)  state one advantage of using a burette rather than a measuring cylinder to measure the  volume of the dilute hydrochloric acid.   .. \t\t[1]",
            "5": "5 0620/52/m/j/21 \u00a9 ucles 2021 [turn over  (f)\t\tin\texperiments\t1\tto\t5,\tthe\tsodium\tcarbonate\twas\tin \texcess.   sketch on the grid\t the\tgraph\tyou\twould\texpect\tif\tall\tof\tthe\texperiments\t were\trepeated\t using\t dilute hydrochloric acid of half the concentration.   label your line f.\t [2] \t [total:\t17]",
            "6": "6 0620/52/m/j/21 \u00a9 ucles 2021 2\t\tyou\tare\tprovided\twith\tone\tsolution,\tsolution\t g,\tand\tone\tsolid,\tsolid\t h. \t\tdo\tthe\tfollowing\ttests\ton\tthe\tsubstances,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.  tests on solution g   divide solution g\tinto\tfour\tapproximately\tequal\tportions\tin\tthree\ttest-tubes\tand\tone\tboiling\ttube. \t\tkeep\tone\tportion\tin\ta\ttest-tube\tfor\tuse\tin\tthe\ttests\ton\tsolid\th.  (a)\t\tto\tthe\tfirst\tportion\tof\tsolution\t g\tin\ta\ttest-tube,\t add\taqueous\t sodium\thydroxide\t dropwise\t and\t then\tin\texcess.   record your observations.      .. \t\t[2]  (b)\t\tto\tthe\tsecond\tportion\tof\tsolution\t g\tin\ta\ttest-tube,\t add\tabout\t1\tcm\tdepth\tof\tdilute\tnitric\tacid\t followed\tby\ta\tfew\tdrops\tof\taqueous\tsilver\tnitrate.   record your observations.   .. \t\t[1]   keep the third portion of solution g for use in (i).  (c)\t\tto\tthe\tportion\tof\tsolution\t g\tin\ta\tboiling\ttube,\tadd\tapproximately\t 15\tcm3 of aqueous  hydrogen\tperoxide.\t test\tany\tgas\tproduced.   record your observations.         .. \t\t[3]  (d)  identify the gas formed in (c).   .. \t\t[1]  (e)  use the results of (a) and (b) to identify solution g.         .. \t\t[2]",
            "7": "7 0620/52/m/j/21 \u00a9 ucles 2021 [turn over  tests on solid h  (f)\t\tcarry\tout\ta\tflame\ttest\ton\tsolid\th.   record your observations.   .. \t\t[1]   place solid h\tin\ta\tboiling\ttube.\tadd\tabout\t10\tcm3 of distilled water to the boiling tube. place a  stopper\tin\tthe\tboiling\ttube\tand\tshake\tthe\ttube\tto\tdissolve\tsolid\t h and form solution h.   divide solution h\tinto\tthree\tapproximately\tequal\t portions\tin\tthree\ttest-tubes.  (g)\t\tto\tthe\tfirst\tportion\tof\tsolution\th\tadd\taqueous\tammonia\tdropwise\tand\tthen\tin\texcess.   record your observations.         .. \t\t[3]  (h)\t\tto\tthe\tsecond\tportion\tof\tsolution\t h\tadd\tapproximately\t 1\tcm\tdepth\tof\tdilute\tnitric\tacid\tfollowed\t by\ta\tfew\tdrops\tof\taqueous\tbarium\tnitrate.   record your observations.      .. \t\t[1]  (i)\t\tto\tthe\tthird\tportion\tof\tsolution\t h\tadd\tyour\tremaining\tportion\tof\tsolution\t g.   record your observations.      .. \t\t[1]  (j)  identify solution h.      .. \t\t[2] \t [total:\t17]",
            "8": "8 0620/52/m/j/21 \u00a9 ucles 2021 3\t\tthe\tmineral\tepsomite\t contains\t hydrated\t magnesium\t sulfate.\twhen\tepsomite\t is\theated\tstrongly,\t it\t loses water and eventually becomes anhydrous magnesium sulfate. \t\tplan\tan\tinvestigation\t to\tfind\tthe\tpercentage\t by\tmass\tof\twater\tin\ta\tsample\tof\tepsomite.\t your\tplan\t should\tinclude\thow\tyou\twould\tcalculate\tthe\tpercentage\tby\tmass\tof\twater\tin\tepsomite. \t\tyou\thave\taccess\tto\tcommon\tlaboratory\tapparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6]",
            "9": "9 0620/52/m/j/21 \u00a9 ucles 2021blank page",
            "10": "10 0620/52/m/j/21 \u00a9 ucles 2021blank page",
            "11": "11 0620/52/m/j/21 \u00a9 ucles 2021notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/52/m/j/21 \u00a9 ucles 2021tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s21_qp_53.pdf": {
            "1": "*1059413392* chemistry  0620/53 paper 5 practical test may/june 2021  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib21 06_0620_53/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/53/m/j/21 \u00a9 ucles 2021 1  you are going to investigate the rate at which hydrogen gas is made when magnesium reacts with  dilute sulfuric acid.   read all of the instructions carefully before starting the experiments.   instructions \t\tyou\tare\tgoing\tto\tdo\tfive\texperiments\tusing\tthe\tapparatus\tshown. trough waterclamp inverted 100  cm3 measuring cylinder conical flaskbungrubber delivery tube  experiment 1  \u25cf use a 25 cm3\tmeasuring\tcylinder\tto\tpour\t25\t cm3 of dilute sulfuric acid into the conical flask.  \u25cf use a 50 cm3\tmeasuring\tcylinder\tto\tpour\t30\t cm3 of distilled water into the conical flask.  \u25cf\tset\tup\tthe\tapparatus\t as\tshown\tin\tthe\tdiagram.\t ensure\tthe\tinverted\t measuring\t cylinder\tis\tfull\t of water.  \u25cf remove the bung from the conical flask.  \u25cf\tadd\ta\tcoiled\tlength\tof\tmagnesium\t ribbon\tto\tthe\tconical\tflask,\timmediately\t replace\tthe\tbung\t and start the timer.  \u25cf measure the volume of gas collected in the inverted measuring cylinder after 30 seconds.   record the volume of gas collected in the table in (a).   experiment 2  \u25cf\tempty\tthe\tconical\tflask\tand\trinse\tit\twith\tdistilled\twater.  \u25cf\trepeat\texperiment\t1\tusing\t20\t cm3 of distilled water instead of 30 cm3.   measure the water using the second 25 cm3 measuring cylinder.   experiment 3  \u25cf\trepeat\texperiment\t2\tusing\t10\t cm3 of distilled water instead of 20 cm3.  experiment 4  \u25cf\trepeat\texperiment\t3\tusing\t5\t cm3\tof\tdistilled\twater\tinstead\tof\t10\t cm3.   experiment 5  \u25cf\trepeat\texperiment\t4\tbut\tdo\tnot\tadd\tany\tdistilled\twater\tto\tthe\tdilute\tsulfuric\tacid.",
            "3": "3 0620/53/m/j/21 \u00a9 ucles 2021 [turn over  (a)\t\tcomplete\tthe\ttable. experimentvolume of dilute sulfuric acid / cm3volume of distilled water / cm3volume of gas collected in 30 seconds / cm3 1 2 3 4 5 \t [4]  (b)  write a suitable scale on the y-axis\t and\tplot\tyour\tresults\tfrom\texperiments\t 1\tto\t5\ton\tthe\tgrid.\t draw\ta\tsmooth\tcurve\tof\tbest\tfit. 00 51 01 52 0 volume of distilled water  / cm3volume of ga s collected in 30 seconds  / cm3 25 30 35 40 \t [4]",
            "4": "4 0620/53/m/j/21 \u00a9 ucles 2021  (c) \textrapolate\t (extend)\t the\tline\ton\tyour\tgraph\tand\tdeduce\tthe\tvolume\tof\tgas\tthat\twould\tbe\t collected in 30 seconds if 35 cm3 of distilled water was added to the dilute sulfuric acid.  .. cm3 \t [2]  (d)  the rate of reaction can be calculated using the equation shown. rate of reaction =volume of gas collected time taken to collect the gas  (i)\t\tuse\tthis\tequation\t to\tcalculate\t the\trate\tof\treaction\t in\texperiment\t 3.\tgive\tthe\tunits\tfor\tthe\t rate you have calculated.  rate = ..  units = .. \t [2]  (ii)\t\tstate\twhich\texperiment,\t1,\t2,\t3,\t4\tor\t5,\t had\tthe\thighest\trate\tof\treaction.   ... \t\t[1]  (e)  the volume of the dilute sulfuric acid was measured using a measuring cylinder. a 25 cm3   pipette\tcan\tbe\tused\tinstead\tof\ta\tmeasuring\tcylinder.  (i)  state one advantage of using a 25 cm3\tpipette\tinstead\tof\ta\tmeasuring\tcylinder.   ... \t\t[1]  (ii)  state one disadvantage of using a 25 cm3\tpipette\tinstead\tof\ta\tmeasuring\tcylinder.   ... \t\t[1]  (f)\t\tname\tanother\titem\tof\tapparatus,\t which\tcan\tbe\tused\tinstead\tof\tan\tinverted\t measuring\t cylinder,\t to collect and measure the volume of gas made in the reaction.   .. \t\t[1]",
            "5": "5 0620/53/m/j/21 \u00a9 ucles 2021 [turn over  (g)\t\tthe\tdiagram\tshows\ta\tmodified\tconical\tflask\tthat\tcan\tbe\tused\tin\tthis\tinvestigation. dilute sulfuric acidglass divider magnesium \t \texplain\tthe\tadvantage\t of\tusing\tthis\ttype\tof\tconical\tflask\tinstead\tof\tthe\ttype\tyou\tused\tin\tthe\t investigation.      .. \t\t[2]  [total:\t18]",
            "6": "6 0620/53/m/j/21 \u00a9 ucles 2021 2\t\tyou\tare\tprovided\twith\ttwo\tsolids,\tsolid\t i and solid j.   do the following tests on the substances, recording all of your observations at each stage.   tests on solid i   place solid i\tin\ta\tboiling\ttube.\tadd\tabout\t10\tcm3 of distilled water to the boiling tube. place a  stopper\tin\tthe\tboiling\ttube\tand\tshake\tthe\ttube\tto\tdissolve\tsolid\t i and form solution i.   divide solution i\tinto\tfour\tapproximately\tequal\tportions\tin\tfour\ttest-tubes.  (a)\t\tto\tthe\tfirst\t portion\tof\tsolution\ti,\t add\taqueous\tsodium\thydroxide\tdropwise\tand\tthen\tin\texcess.   record your observations.         .. \t\t[2]  (b)\t\tto\tthe\tsecond\tportion\tof\tsolution\t i, add aqueous ammonia gradually until there is no further  change.   record your observations.      .. \t\t[2]  (c)\t\tto\tthe\tthird\tportion\tof\tsolution\t i,\tadd\tabout\t1\tcm\tdepth\tof\tdilute\tnitric\tacid\tfollowed\t by\ta\tfew\t drops\tof\taqueous\tsilver\tnitrate.\tleave\tthe\tmixture\tto\tstand\tfor\tabout\t5\tminutes.   record your observations.   .. \t\t[1]  (d)\t\tto\tthe\tfourth\tportion\tof\tsolution\t i,\tadd\tabout\t2\t cm\tdepth\tof\taqueous\tsodium\tcarbonate.   record your observations.   .. \t\t[1]  (e)  use your observations from (a), (b) and (c) to identify solid i.      .. \t\t[2]",
            "7": "7 0620/53/m/j/21 \u00a9 ucles 2021 [turn over   tests on solid j  (f)\t\tcarry\tout\ta\tflame\ttest\ton\tsolid\tj.   record your observations.   .. \t\t[1]  (g) (i)\t \tplace\tapproximately\t half\tof\tsolid\t j\tin\ta\tboiling\ttube.\tadd\tabout\t10\tcm3 of dilute sulfuric acid  to solid j\tin\tthe\tboiling\ttube.\t test\tany\tgas\tproduced.   record your observations.   .   ... \t\t[2]  (ii)\t\tidentify\tthe\tgas\tproduced\tin\t (g)(i).   ... \t\t[1]  (h)  place the remaining solid j\t in\ta\tboiling\ttube.\tadd\tabout\t10\tcm3 of distilled water to the  boiling\ttube.\tplace\ta\tstopper\tin\tthe\tboiling\ttube\tand\tshake\tthe\ttube\tto\tdissolve\t solid\t j and form  solution j.   divide solution j\tinto\ttwo\tapproximately\tequal\tportions\tin\ttwo\ttest-tubes.  (i)\t\tto\tthe\tfirst\tportion\tof\tsolution\t j,\tadd\tabout\t1\t cm\tdepth\tof\taqueous\tsodium\thydroxide.   record your observations.   .   ... \t\t[1]  (ii)\t\tto\tthe\tsecond\tportion\tof\tsolution\t j,\tadd\tabout\t2\t cm\tdepth\tof\taqueous\tcopper( ii) sulfate.   record your observations.   .   ... \t\t[1]  (i)  use your observations from (f) and (g) to identify solid j.      .. \t\t[2] \t [total:\t16]",
            "8": "8 0620/53/m/j/21 \u00a9 ucles 2021 3\t\tthe\tenergy\tgiven\tout\twhen\tdifferent\t liquid\talcohols\t are\tburned\tcan\tbe\tcompared\t using\tthe\tapparatus \t shown. thermometer test-tube water spirit burner liquid alcoho l \t\tdescribe\t how\tthe\tapparatus\t shown\tcan\tbe\tused\tto\tcompare\t the\tamount\tof\tenergy\tgiven\tout\tby\t three\tdifferent\t liquid\talcohols,\t ethanol,\t propanol\t and\tbutanol.\t your\tanswer\tshould\tinclude\thow\tthe\t results can be used to determine which fuel gives out the most energy.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6]",
            "9": "9 0620/53/m/j/21 \u00a9 ucles 2021blank page",
            "10": "10 0620/53/m/j/21 \u00a9 ucles 2021blank page",
            "11": "11 0620/53/m/j/21 \u00a9 ucles 2021notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/53/m/j/21 \u00a9 ucles 2021tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s21_qp_61.pdf": {
            "1": "*3435140504* chemistry  0620/61 paper 6 alternative to practical may/june 2021  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib21 06_0620_61/3rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/61/m/j/21 \u00a9 ucles 2021 1  many indicators are coloured substances obtained from plants.   a student extracted the coloured substances from some berries using the method shown. the berries were crushedthe crushed berries were heated in water to form a coloured solutio nthe solid was removed from the coloured solutio nacb coloure d solutio n  (a)  name the items of apparatus labelled a, b and c.  a    b    c    [3]  (b)  the student analysed the coloured solution using chromatography.  (i)  complete the diagram to show:  \u25cf where the spot of coloured solution should be placed on the paper  \u25cf the level of the solvent in the beaker. beaker chromatography pape rbaseline draw n in pencillid  [2]  (ii)  explain why pencil is used to draw the baseline on the chromatography paper.   .   ...   [1]",
            "3": "3 0620/61/m/j/21 \u00a9 ucles 2021 [turn over  (c)  the student made two chromatograms. after chromatography, one chromatogram was dipped  in dilute hydrochloric acid and one was dipped in aqueous sodium hydroxide.   the results are shown. chromatogram dipped in aqueous sodium hydroxideblue green chromatogram dipped in dilute hydrochloric acidred blue  (i)  determine the number of coloured substances in the solution obtained from the berries.   ...   [1]  (ii)  the table gives the colours of some indicators in acid and alkali. name of indicator colour in acid colour in alkali anthocyanin red blue bromothymol blue yellow blue congo red blue red methyl purple purple green   use the data in the table and the results to give a possible identity for one indicator in the  berries.   ...   [1]  [total: 8]",
            "4": "4 0620/61/m/j/21 \u00a9 ucles 2021blank page",
            "5": "5 0620/61/m/j/21 \u00a9 ucles 2021 [turn over 2  a student investigated the temperature decrease when sodium hydrogencarbonate reacts with  dilute hydrochloric acid.   the student did six experiments.  experiment 1  \u25cf using a measuring cylinder, 25 cm3 of dilute hydrochloric acid was poured into a conical flask.  \u25cf the initial temperature of the acid was measured using a thermometer.  \u25cf 1 g of sodium hydrogencarbonate was added to the conical flask. at the same time a stop\u2011clock  was started.  \u25cf the acid and sodium hydrogencarbonate mixture in the conical flask was stirred continuously  using the thermometer.  \u25cf the temperature of the mixture after 1 minute was measured.  \u25cf the conical flask was rinsed with distilled water.  experiment 2  \u25cf experiment 1 was repeated using 2 g of sodium hydrogencarbonate instead of 1 g.  experiment 3  \u25cf experiment 1 was repeated using 3 g of sodium hydrogencarbonate instead of 1 g.  experiment 4  \u25cf experiment 1 was repeated using 5 g of sodium hydrogencarbonate instead of 1 g.  experiment 5  \u25cf experiment 1 was repeated using 6 g of sodium hydrogencarbonate instead of 1 g.  experiment 6  \u25cf experiment 1 was repeated using 7 g of sodium hydrogencarbonate instead of 1 g.",
            "6": "6 0620/61/m/j/21 \u00a9 ucles 2021  (a)  use the thermometer diagrams to complete the table and calculate the temperature decreases. experimentmass of sodium hydrogencarbonate  / gthermometer diagraminitial temperature of acid / \u00b0cthermometer diagramtemperature after 1 minute / \u00b0ctemperature decrease / \u00b0c 1 130 25 2025 20 15 2 230 25 2025 20 15 3 330 25 2020 15 10 4 530 25 2020 15 10 5 630 25 2020 15 10 6 730 25 2020 15 10  [4]",
            "7": "7 0620/61/m/j/21 \u00a9 ucles 2021 [turn over  (b)  plot the results from experiments 1 to 6 on the grid.   draw two best-fit straight lines through your points. the first straight line should be for the first  three points and must pass through (0,0). the second straight line should be for the last three  points and must be horizontal. extend your straight lines so that they meet each other. temperature decrease  / \u00b0c 0123 mass of sodium hydrogencarbonate  / g4 56712 10 8 6 4 2 0  [4]  (c) (i)  from your graph, determine the temperature decrease and mass of sodium  hydrogencarbonate where your two straight lines meet. include appropriate units in your  answer.   show clearly on the grid  how you worked out your answer.   temperature decrease = ..   mass of sodium hydrogencarbonate = ..  [3]  (ii)  explain why the temperature decrease becomes constant for high masses of sodium  hydrogencarbonate.   .   ...   [1]",
            "8": "8 0620/61/m/j/21 \u00a9 ucles 2021  (d)  the investigation was repeated with dilute hydrochloric acid of half the concentration, but the  same volume.   sketch on the grid  the graph you would expect to obtain.   label your line d. [2]  (e)  suggest two changes that could be made to the apparatus that would improve the accuracy of  the results. for each change explain why it would improve the accuracy of the results.   change 1     explanation 1  .      change 2     explanation 2  .     [4]  [total: 18]",
            "9": "9 0620/61/m/j/21 \u00a9 ucles 2021 [turn over 3  solid e and solution f were analysed.   tests were done on each substance.   tests on solid e tests observations test 1 about half of solid e was placed in a test\u2011tube and  heated gently.steam was given off; condensation appeared near the mouth of the test\u2011tube the remaining solid e was dissolved in distilled water  to produce solution e. the solution was divided  into four equal portions in three test\u2011tubes and a  boiling tube. test 2 about 1 cm3 of dilute nitric acid followed by a few  drops of aqueous silver nitrate were added to the first  portion of solution e.no visible change test 3 about 1 cm3 of dilute nitric acid followed by a few  drops of aqueous barium nitrate were added to the  second portion of solution e.white precipitate test 4 excess aqueous ammonia was added to the third  portion of solution e.white precipitate test 5 aqueous sodium hydroxide was added dropwise and  then in excess to the fourth portion of solution e in  the boiling tube.white precipitate which dissolved in excess to form a colourless solution test 6 the product from test 5 was warmed gently and any  gas given off was tested with damp red litmus paper.the red litmus paper turned blue  (a)  state the conclusion that can be made from the observations in test 1.      ..   [1]  (b)  state the conclusion that can be made from the observation in test 2.      ..   [1]",
            "10": "10 0620/61/m/j/21 \u00a9 ucles 2021  (c)  identify the three ions in solid e.      ..   [3]  tests on solution f   solution f was aqueous sodium hydroxide.   complete the expected observations.  (d)  a flame test was carried out on solution f.   observations     [1]  (e)  the remaining solution f was divided into two approximately equal portions in two test\u2011tubes.  (i)  to the first portion of solution f a few drops of universal indicator solution were added.  observations  .   [1]  (ii)  to the second portion of solution f approximately 2 cm3 of aqueous copper( ii) sulfate was  added.  observations  .   [1]  [total: 8]",
            "11": "11 0620/61/m/j/21 \u00a9 ucles 2021 [turn over 4  dilute hydrochloric acid reacts with calcium carbonate to make carbon dioxide gas. the apparatus  shown in the diagram can be used to follow the progress of the reaction. the carbon dioxide gas  leaves the flask causing the mass shown on the balance to decrease. 260.00cotton wool dilute hydrochloric acid balancecalcium carbonate   plan an investigation, using the apparatus shown in the diagram, to find out how the temperature  of the dilute hydrochloric acid affects the rate of the reaction. your plan should include how your  results will show how the temperature of the dilute hydrochloric acid affects the rate of the reaction.   you are provided with dilute hydrochloric acid, calcium carbonate and common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "12": "12 0620/61/m/j/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s21_qp_62.pdf": {
            "1": "*2018500414* chemistry  0620/62 paper 6 alternative to practical may/june 2021  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib21 06_0620_62/rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/62/m/j/21 \u00a9 ucles 2021 1  barium sulfate is an insoluble salt. barium sulfate can be made by reacting excess aqueous  sodium sulfate with aqueous barium chloride. sodium sulfate  +  barium chloride  \u2192  sodium chloride  +  barium sulfate   a student made a sample of barium sulfate using the following steps. excess aqueous sodium sulfate was added to aqueous barium chloridethe mixture was stirredthe solid barium sulfate was removed from the mixturestep 1 step 2s tep 3 bresidue of solid barium sulfate astiraqueous sodium sulfate aqueous barium chloride  (a)  name the items of apparatus labelled a and b.  a    b    [2]  (b)  name the process shown in step 3.   ..   [1]  (c)  the general name for the solid in step 3 is residue.   state the general name for the solution obtained from the process in step 3.   ..   [1]",
            "3": "3 0620/62/m/j/21 \u00a9 ucles 2021 [turn over  (d)  two more steps, step 4 and step 5, are needed to obtain a pure sample of barium sulfate. in  each of these steps something is removed from the residue.   state what is done in each of step 4 and step 5 and identify the substance removed from the  barium sulfate.  step 4       substance removed  ...  step 5       substance removed  ...  [4]  [total: 8]",
            "4": "4 0620/62/m/j/21 \u00a9 ucles 2021blank page",
            "5": "5 0620/62/m/j/21 \u00a9 ucles 2021 [turn over 2  a student investigated the volume of gas made when sodium carbonate reacts with dilute  hydrochloric acid.   five experiments were carried out using the apparatus shown. trough waterclamp inverted 100  cm3 measuring cylinder boiling tubebungrubber delivery tube   experiment 1  \u25cf using a measuring cylinder, 16 cm3 of dilute hydrochloric acid was poured into a boiling tube.  \u25cf the apparatus was set up as shown in the diagram.  \u25cf the bung was removed from the boiling tube.  \u25cf 2.5 g of sodium carbonate was added to the boiling tube and the bung was immediately  replaced.  \u25cf when no more gas was being collected, the volume of gas in the measuring cylinder was  measured.   experiment 2  \u25cf experiment 1 was repeated using 14 cm3 of dilute hydrochloric acid instead of 16 cm3.   experiment 3  \u25cf experiment 2 was repeated using 12 cm3 of dilute hydrochloric acid instead of 14 cm3.   experiment 4  \u25cf experiment 3 was repeated using 10 cm3 of dilute hydrochloric acid instead of 12 cm3.   experiment 5  \u25cf experiment 4 was repeated using 6 cm3 of dilute hydrochloric acid instead of 10 cm3.",
            "6": "6 0620/62/m/j/21 \u00a9 ucles 2021  (a)  use the information in the description of the experiments and the inverted measuring cylinder  diagrams to complete the table. experimentvolume of dilute hydrochloric acid / cm3inverted measuring cylinder diagramvolume of gas collected / cm3 160 50 40 260 50 40 360 50 40 450 40 30 540 30 20  [3]",
            "7": "7 0620/62/m/j/21 \u00a9 ucles 2021 [turn over  (b)  write a suitable scale on the y-axis and plot the results from experiments 1 to 5 on the grid.  draw a straight line of best fit. 4681 01 2 volume of dilute hydrochloric aci d / cm3volume of gas collecte d / cm3 14 16  [4]  (c) (i)  from your graph, deduce the volume of gas that would be collected if 7 cm3 of dilute  hydrochloric acid was used.   show clearly on the grid  how you worked out your answer.  .. cm3  [2]  (ii)  the volume of gas made per cm3 of dilute hydrochloric acid can be calculated using the  equation shown. volume of gas per cm3 of acid =volume of gas collected in cm3 volume of acid in cm3   use this equation and your answer to (c)(i) to calculate the volume of gas made per cm3  of dilute hydrochloric acid.  ..  [1]",
            "8": "8 0620/62/m/j/21 \u00a9 ucles 2021  (d)  the bung was removed and then replaced immediately after the sodium carbonate was added  to the boiling tube.  (i)  explain why the bung must be replaced immediately after the sodium carbonate is added  to the boiling tube.   .   ...   [1]  (ii)  explain how the apparatus could be altered so that the bung does not have to be removed.  you may draw a diagram to explain your answer.   .   ...   [2]  (e)  state one advantage of using a burette rather than a measuring cylinder to measure the  volume of the dilute hydrochloric acid.   ..   [1]  (f)  in experiments 1 to 5, the sodium carbonate was in excess.   sketch on the grid the graph you would expect if all of the experiments were repeated using  dilute hydrochloric acid of half the concentration.   label your line f. [2]  [total: 16]",
            "9": "9 0620/62/m/j/21 \u00a9 ucles 2021 [turn over 3  solution g and solid h were analysed.  tests on solution g tests observations solution g was divided into three equal portions  in three test-tubes. test 1 sodium hydroxide was added dropwise and  then in excess to the first portion of solution g.white precipitate which did not dissolve in excess test 2 about 1 cm3 of dilute nitric acid followed by a  few drops of aqueous silver nitrate were added  to the second portion of solution g.yellow precipitate test 3 about 10 cm3 of aqueous hydrogen peroxide  was added to the third portion of solution g.  the gas produced was tested.the mixture became brown and bubbled; the gas relit a glowing splint  (a)  identify the gas produced in test 3.   ..   [1]  (b)  use the results of test 1 and test 2 to identify solution g.         ..   [2]",
            "10": "10 0620/62/m/j/21 \u00a9 ucles 2021  tests on solid h   solid h was hydrated copper( ii) sulfate.   complete the expected observations.  (c)  about half of solid h was placed in a boiling tube and heated using a bunsen burner.  observations  ..   ..   [2]  (d)  a flame test was carried out on solid h.  observations     [1]   the remaining solid h was placed in a boiling tube. about 10 cm3 of distilled water was added to the  boiling tube. the tube was shaken to dissolve solid h and form solution h.   solution h was divided into two approximately equal portions in two test-tubes.  (e)  aqueous ammonia was added dropwise and then in excess to the first portion of solution h.  observations  ..      ..   [3]  (f)  approximately 1 cm3 of dilute nitric acid followed by a few drops of aqueous barium nitrate were  added to the second portion of solution h.  observations     [1]  [total: 10]",
            "11": "11 0620/62/m/j/21 \u00a9 ucles 2021 [turn over 4  the mineral epsomite contains hydrated magnesium sulfate. when epsomite is heated strongly, it  loses water and eventually becomes anhydrous magnesium sulfate.   plan an investigation to find the percentage by mass of water in a sample of epsomite. your plan  should include how you would calculate the percentage by mass of water in epsomite.   you have access to common laboratory apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "12": "12 0620/62/m/j/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_s21_qp_63.pdf": {
            "1": "*2770353343* chemistry  0620/63 paper 6 alternative to practical may/june 2021  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib21 06_0620_63/3rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/63/m/j/21 \u00a9 ucles 2021 1  cobalt( ii) sulfate is a soluble salt. it can be made by reacting insoluble cobalt( ii) oxide with  dilute sulfuric acid.   a student made a sample of hydrated cobalt( ii) sulfate using the following steps. cobalt( ii) oxide was added to dilute sulfuric acidthe mixture was stirred and heatedthe mixture was allowed to coolstep 1 step 2 step 3 unreacted solidstir cobalt( ii) oxide dilute sulfuric acid heatbaqueou s cobalt( ii) sulfat ea  (a)  name the items of apparatus labelled a and b.  a    b    [2]  (b) (i)  suggest why the mixture was heated in step 2.   .   ...   [1]  (ii)  name an item of apparatus that can be used to heat the mixture in step 2.   ...   [1]  (c)  name the reactant which was in excess.   explain your answer.      ..   [1]",
            "3": "3 0620/63/m/j/21 \u00a9 ucles 2021 [turn over  (d)  additional steps are required to obtain pure cobalt( ii) sulfate.  (i)  the unreacted solid is removed from the aqueous cobalt( ii) sulfate.   name the process used to remove the unreacted solid.   ...   [1]  (ii)  describe how crystals of hydrated cobalt( ii) sulfate could be made from the solution  obtained in (i).   .   .   .   ...   [2]  [total: 8]",
            "4": "4 0620/63/m/j/21 \u00a9 ucles 2021blank page",
            "5": "5 0620/63/m/j/21 \u00a9 ucles 2021 [turn over 2  a student investigated the rate at which hydrogen gas was made when magnesium reacted with  dilute sulfuric acid.   five experiments were carried out using the apparatus shown. trough waterclamp inverted 100  cm3 measuring cylinder conical flaskbungrubber delivery tube   experiment 1  \u25cf using a measuring cylinder, 25 cm3 of dilute sulfuric acid was poured into a conical flask.  \u25cf using a different measuring cylinder, 30 cm3 of distilled  water was poured into the conical flask.  \u25cf the apparatus was set up as shown in the diagram.  \u25cf the bung was removed from the conical flask.  \u25cf a coiled length of magnesium ribbon was added to the conical flask, the bung was replaced  immediately and a timer started.  \u25cf the volume of gas collected in the inverted measuring cylinder after 30 seconds was measured.   experiment 2  \u25cf experiment 1 was repeated using 20 cm3 of distilled water instead of 30 cm3.   experiment 3  \u25cf experiment 1 was repeated using 10 cm3 of distilled water instead of 30 cm3.   experiment 4  \u25cf experiment 1 was repeated using 5 cm3 of distilled water instead of 30 cm3.   experiment 5  \u25cf experiment 1 was repeated without adding any distilled water to the dilute sulfuric acid.",
            "6": "6 0620/63/m/j/21 \u00a9 ucles 2021  (a)  use the information in the description of the experiments and the inverted measuring cylinder  diagrams to complete the table. experimentvolume of dilute sulfuric acid / cm3volume of distilled water / cm3inverted measuring  cylinder diagramvolume of gas collected in 30 seconds / cm3 130 20 10 230 20 10 350 40 30 470 60 50 5100 90 80  [4]",
            "7": "7 0620/63/m/j/21 \u00a9 ucles 2021 [turn over  (b)\t\tplot\tthe\tresults\tfrom\texperiments\t1\tto\t5\ton\tthe\tgrid. \tdraw\ta\tsmooth\tcurve\tof\tbest\tfit. 05 10 15 20 volume of distilled water  / cm3volume of ga s collected in 30 seconds  / cm3 25 30 35 40100 80 60 40 20 0  [3]  (c)  extrapolate (extend) the line on your graph and deduce the volume of gas that would be  collected in 30 seconds if 35 cm3 of distilled water was added to the dilute sulfuric acid.  .. cm3  [2]",
            "8": "8 0620/63/m/j/21 \u00a9 ucles 2021  (d) the rate of reaction can be calculated using the equation shown. rate of reaction =volume of gas collected time taken to collect the gas  (i)  use this equation to calculate the rate of reaction in experiment 3. give the units for the  rate you have calculated.  rate = ..  units = ..  [2]  (ii)  state which experiment, 1, 2, 3, 4 or 5, had the highest rate of reaction.   ...   [1]  (e)  the volume of the dilute sulfuric acid was measured using a measuring cylinder. a 25 cm3   pipette could have been used instead of a measuring cylinder.  (i)  state one advantage of using a 25 cm3 pipette instead of a measuring cylinder.   ...   [1]  (ii)  state one disadvantage of using a 25 cm3 pipette instead of a measuring cylinder.   ...   [1]  (f)  name another item of apparatus, which can be used instead of an inverted measuring cylinder,  to collect and measure the volume of gas made in the reaction.   ..   [1]",
            "9": "9 0620/63/m/j/21 \u00a9 ucles 2021 [turn over  (g)\t\tthe\tdiagram\tshows\ta\tmodified\tconical\tflask\tthat\tcould\tbe\tused\tin\tthis\tinvestigation. dilute sulfuric acidglass divider magnesium \t \texplain\t the\tadvantage\t of\tusing\tthis\ttype\tof\tconical\tflask\tinstead\tof\tthe\ttype\tused\tin\tthe\t investigation.         ..   [2]  [total: 17]",
            "10": "10 0620/63/m/j/21 \u00a9 ucles 2021 3  solid i and solid j were analysed. solid i was chromium( iii) chloride.   tests on solid i   complete the expected observations.   solid i was placed in a boiling tube and about 10 cm3 of distilled water was added to the boiling  tube. the mixture was shaken to dissolve solid i and form solution i. solution i was divided into  four portions in four test-tubes.  (a)\t\taqueous\t sodium\thydroxide\t was\tadded\tdropwise\t and\tthen\tin\texcess\tto\tthe\tfirst\tportion\tof\t solution i.   observations  ..      ..   [2]  (b)  aqueous ammonia was added dropwise and then in excess to the second portion of solution i.  observations  ..      ..   [2]  (c)  about 1 cm3 of dilute nitric acid followed by a few drops of aqueous silver nitrate were added to  the third portion of solution i.  observations     [1]  (d)  about 1 cm3 of dilute nitric acid followed by a few drops of aqueous barium nitrate were added  to the fourth portion of solution i.  observations     [1]",
            "11": "11 0620/63/m/j/21 \u00a9 ucles 2021 [turn over  tests on solid j tests observations test 1 a\tflame\ttest\twas\tcarried\tout\ton\tsolid\t j. lilac\tflame the remaining solid j was placed in a  boiling tube and about 10 cm3 of distilled water  was added to the boiling tube. the mixture was  shaken to dissolve solid j and form solution j. test 2 about 5 cm3 of dilute nitric acid was added to  solution j. any gas produced was tested.effervescence the gas turned limewater milky test 3 a few drops of aqueous silver nitrate were  added to the mixture formed in test 2.no visible change  (e)  identify the gas formed in test 2.   ..   [1]  (f)  identify solid j.      ..   [2]  [total: 9]",
            "12": "12 0620/63/m/j/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. 4\t\tthe\tenergy\tgiven\tout\twhen\tdifferent\t liquid\talcohols\t are\tburned\tcan\tbe\tcompared\t using\tthe\tapparatus \t shown. thermometer test-tube water spirit burner liquid alcoho l   describe how the apparatus shown can be used to compare the amount of energy given out by  three\tdifferent\t liquid\talcohols,\t ethanol,\t propanol\t and\tbutanol.\t your\tanswer\tshould\tinclude\thow\tthe\t results can be used to determine which fuel gives out the most energy.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]"
        },
        "0620_w21_qp_11.pdf": {
            "1": "    this document has 12 pages.  ib21 11_0620_11/2rp   \u00a9 ucles 2021   [turn ove r   *2632736094*cambridge igcse\u2122       chemistry 0620/11     paper 1 multiple choice (core)  october/november 2021     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate number on the multiple choice answer sheet in the spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/11/o/n/21  1 decane has a freezing point of \u201330  \u00b0c and a boiling point of 174  \u00b0c.    a small sample of decane is placed in an open beaker in an oven at a temperature of 120  \u00b0c and  at atmospheric pressure for 24 hours.    what happens to the sample of decane?  a it boils.  b it evaporates.  c it melts.  d it sublimes.     2 a student put exactly 25.00  cm3 of dilute hydrochloric acid into a conical flask.    the student added 2.5  g of solid sodium carbonate and measured the change in temperature of  the mixture.    which apparatus does the student need to use?  a balance, measuring cylinder, thermometer  b balance, pipette, stopwatch  c balance, pipette, thermometer  d burette, pipette, thermometer     3 a student separates sugar from pieces of broken glass by dissolving the sugar in water and  filtering off the broken glass.    filtrate     what is the filtrate?  a broken glass only  b broken glass and sugar solution  c pure water  d sugar solution     ",
            "3": "3     \u00a9 ucles 2021 0620/11/o/n/21 [turn over  4 two isotopes of carbon are 12c and 14c.    which statement about these two isotopes is correct?  a their electronic structure is different.  b they have different numbers of nucleons.  c they have different numbers of protons.  d they have the same number of neutrons.      5 which description of brass is correct?  a alloy  b compound  c element  d non-metal     6 the element livermorium, lv, was discovered in the year 2000.    which statement predicts what will happen to an lv atom when it forms an lv 2\u2013 ion?  a the atom will gain two electrons.  b the atom will lose two electrons.  c the atom will lose two protons.  d the atom will gain two protons.     7 which substance is a diatomic covalent compound?  a c l  2 b hc l c h 2o d mgo      8 which statement about carbon is correct?  a diamond and graphite both have simple molecular structures.  b diamond and graphite are both used to make cutting tools.  c each carbon atom in diamond is bonded to three other carbon atoms.  d graphite conducts electricity and has a giant covalent structure.      9 the formula of sodium chlorate( v) is nac l o3.    what is the relative formula mass of sodium chlorate( v), nac l o3?  a 52.0 b 74.5 c 106.5 d 223.5     ",
            "4": "4  \u00a9 ucles 2021 0620/11/o/n/21  10 which statements about the products of electrolysis, using inert electrodes, are correct?    1 when molten lead( ii) bromide is electrolysed, bromine is formed at the cathode.  2 when dilute sulfuric acid is electrolysed, oxygen is formed at the anode.  3 when concentrated aqueous sodium chloride is electrolysed, sodium is formed at  the cathode.  4 when concentrated hydrochloric acid is electrolysed, chlorine is formed at the  anode.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     11 the temperature decreases when aqueous ethanoic acid reacts with solid sodium carbonate to form a salt.    which type of reaction and energy change occur?     type of reaction energy change  a neutralisation endothermic  b neutralisation exothermic  c redox endothermic  d redox exothermic     12 which gas is used as a fuel?  a helium  b hydrogen  c nitrogen  d oxygen      13 solid copper( ii) carbonate reacts with dilute sulfuric acid.    cuco 3  +  h 2so 4  \u2192  cuso 4  +  co 2  +  h 2o    the rate of the reaction can be changed by varying the conditions.    which changes always increase the rate of this chemical reaction?    1 increasing the concentration of sulfuric acid  2 increasing the size of the pieces of copper( ii) carbonate  3 increasing the temperature  4 increasing the volume of sulfuric acid    a 1, 3 and 4 b 1 and 3 only c 2 and 3 d 3 and 4 only ",
            "5": "5     \u00a9 ucles 2021 0620/11/o/n/21 [turn over  14 some changes are shown in the table.    in which rows are the changes described correctly?     chemical change physical change  1 rusting iron melting ice  2 burning ethanol evaporating ethanol  3 melting iron evaporating ethanol  4 cracking hydrocarbons burning methane    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     15 x is a pink solid.    y is a blue solid.    when x is heated, water is produced and the solid turns blue.    when water is added to y, the solid turns pink.    what are x and y?     x y  a anhydrous cobalt( ii) chloride hydrated cobalt( ii) chloride  b hydrated cobalt( ii) chloride anhydrous cobalt( ii) chloride  c anhydrous copper( ii) sulfate hydrated copper( ii) sulfate  d hydrated copper( ii) sulfate anhydrous copper( ii) sulfate      16 carbon reacts with carbon dioxide as shown.    co 2  +  c  \u2192  2co    which statement about this reaction is correct?  a carbon dioxide and carbon are both oxidised.  b carbon dioxide and carbon are both reduced.  c carbon dioxide is reduced and carbon is oxidised.  d carbon dioxide is oxidised and carbon is reduced.     ",
            "6": "6  \u00a9 ucles 2021 0620/11/o/n/21  17 which substances do not produce water as a product when they are reacted together?  a calcium hydroxide and ammonium chloride  b calcium carbonate and dilute hydrochloric acid  c copper( ii) oxide and dilute nitric acid  d zinc and dilute sulfuric acid      18 the surface of magnesium ribbon reacts with the air to form magnesium oxide.    which statement explains why the layer of magnes ium oxide is removed by dilute hydrochloric  acid?  a magnesium is a base.  b magnesium ribbon reacts with hydrochloric acid.  c magnesium oxide is a base.  d magnesium oxide is an acid.      19 copper( ii) chloride crystals are made by adding solid copper( ii) carbonate to dilute  hydrochloric acid until no more dissolves.    which process is used to obtain pure copper( ii) chloride crystals from the mixture?  a distillation of the mixture  b evaporation of the mixture  c filtration followed by drying of the residue  d filtration followed by evaporation of the filtrate      20 which statement about aqueous sodium hydroxide is correct?  a when it is added to a solution containing sulfate ions, a white precipitate is formed.  b when it is added to a solution of copper( ii) ions, a blue precipitate is formed which dissolves  in excess to give deep blue solution.  c when it is added to a solution of iron( ii) ions, a green precipitate is formed which does not  dissolve in excess.  d when it is added to ammonium chloride, a gas is produced which turns blue litmus red.     ",
            "7": "7     \u00a9 ucles 2021 0620/11/o/n/21 [turn over  21 a period of the periodic table is shown.    group i ii iii iv v vi vii viii  element r s t v w x y z    the letters are not their chemical symbols.    which statement is correct?  a element r does not conduct electricity.  b elements r and y react together to form an ionic compound.  c element z exists as a diatomic molecule.  d element z reacts with element t.      22 what are the products of the reaction between sodium and water?  a hydrogen and sodium hydroxide  b hydrogen and sodium oxide  c oxygen and sodium hydroxide  d oxygen and sodium oxide      23 element x has a high density, a high melting point and a high electrical conductivity.    it forms many coloured compounds.    element x and many of its compounds act as catalysts.    what could be the atomic number of x?  a 19 b 26 c 33 d 35     24 the noble gases are in group viii of the periodic table.    which statement explains why noble gases are unreactive?  a they all have eight electrons in their outer shells.  b they all have full outer shells.  c they are all gases.  d they are all monoatomic.     ",
            "8": "8  \u00a9 ucles 2021 0620/11/o/n/21  25 which statement is correct for all metals?  a they conduct electricity when molten.  b they gain electrons when they form ions.  c they have a low density.  d they have a low melting point.      26 which statement about the extraction of metals is correct?  a aluminium is extracted from the ore bauxite by electrolysis.  b aluminium is extracted from the ore hematite by electrolysis.  c iron is extracted from the ore bauxite by electrolysis.  d iron is extracted from the ore hematite by electrolysis.      27 which row identifies a use of mild steel and a use of stainless steel?     mild steel stainless steel  a chemical plant and cutlery car bodies and machinery  b car bodies and chemical plant machinery and cutlery  c machinery and chemical plant car bodies and cutlery  d car bodies and machinery chemical plant and cutlery     28 the diagrams show some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treated?  a 1 only b 2 only c 3 only d 1, 2 and 3     ",
            "9": "9     \u00a9 ucles 2021 0620/11/o/n/21 [turn over  29 which air pollutants can cause damage to buildings made of limestone?    1 carbon monoxide  2 lead compounds  3 oxides of nitrogen  4 sulfur dioxide    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     30 which statement about fertilisers is correct?  a ammonium sulfate, (nh 4)2so 4, is a better fertiliser than ammonium nitrate, nh 4no 3, because  it contains more oxygen.  b ammonium phosphate, (nh 4)3po 4, is a good fertiliser because it contains hydrogen.  c potassium nitrate, kno 3, is a good fertiliser because it provides potassium and nitrogen.  d urea, (nh 2)2co, is a good fertiliser because it contains carbon.      31 sulfur burns to make sulfur dioxide.    which row describes a source of sulfur and a use of sulfur dioxide?     source of sulfur use of sulfur dioxide  a the air food preservative  b the air treating acidic soils  c underground deposits food preservative  d underground deposits treating acidic soils    32 lime (calcium oxide) is used to treat waste water from a factory.    which substance is removed by the lime?  a ammonia  b sodium chloride  c sodium hydroxide  d sulfuric acid     ",
            "10": "10  \u00a9 ucles 2021 0620/11/o/n/21  33 which compound is correctly named?    hch hh hhhc ca ethane o ohc hch hh hchh ch hhb ethanoic acidc methened ethene      34 fuel x produces carbon dioxide and water when it is burned in air. so does fuel y.    what could x and y be?     x y  a c h 2  b c c 8h18  c ch 4 h 2  d ch 4 c 8h18     35 which hydrocarbon is the main constituent of natural gas?  a butane  b ethane  c methane  d propane     36 which statements about ethene are correct?    1 it contains a c=c bond.  2 it does not decolourise bromine water. 3 its molecules can join together to form long chain compounds.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     ",
            "11": "11       permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.    to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.  cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2021 0620/11/o/n/21  37 part of the structure of a very large molecule is shown.    ch hch hch coh ohch hch oh hch hcoh h    which term describes the small unit used to make this molecule?  a hydrocarbon  b monomer  c polymer  d saturated      38 what is the total number of single covalent bonds in a molecule of ethanol?  a 5 b 6 c 7 d 8      39 which statement about aqueous ethanoic acid is correct?  a it reacts with magnesium to produce a salt and hydrogen.  b it reacts with sodium hydroxide to produce a salt and hydrogen.  c it reacts with ammonium salts to produce ammonia.  d it turns red litmus blue.      40 three statements about synthetic polymers are listed.    1 man-made fibres are used for making clothing.  2 plastics can cause pollution problems both on land and at sea. 3 plastics which do not rot away are described as non-biodegradable.    which statements are correct?  a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3      ",
            "12": "12  \u00a9 ucles 2021 0620/11/o/n/21   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w21_qp_12.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 11_0620_12/2rp   \u00a9 ucles 2021   [turn ove r   *3466473635 *cambridge igcse\u2122       chemistry 0620/12     paper 1 multiple choice (core)  october/november 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/12/o/n/21  1 which row describes what happens to the particles in solid iodi ne when it is heated and turned  into a gas?     separation  of particles speed  of particles  a closer together faster  b closer together slower  c further apart faster  d further apart slower     2 a student put exactly 25.00  cm3 of dilute hydrochloric acid into a conical flask.    the student added 2.5  g of solid sodium carbonate and measured the change in temperat ure of  the mixture.    which apparatus does the student need to use?  a balance, measuring cylinder, thermometer  b balance, pipette, stopwatch  c balance, pipette, thermometer  d burette, pipette, thermometer     3 a student separates sugar from pieces of broken glass by disso lving the sugar in water and  filtering off the broken glass.    filtrate     what is the filtrate?  a broken glass only  b broken glass and sugar solution  c pure water  d sugar solution    ",
            "3": "3     \u00a9 ucles 2021 0620/12/o/n/21 [turn over  4 how many protons, neutrons and electrons are there in one atom of the isotope 27 13al?     protons neutrons electrons  a 13 13 13  b 13 14 13  c 14 13 13  d 14 14 13     5 which description of brass is correct?  a alloy  b compound  c element  d non-metal     6 rubidium is in group i and iodine is in group vii of the period ic table.    which row describes what happens when rubidium and iodine react  together to form rubidium  iodide?     rubidium iodine  a each atom gains one electron each atom loses one electron  b each atom loses one electron each atom gains one electron  c each atom loses more than one electron each atom gains more tha n one electron  d   each atom neither gains  nor loses an electron each atom neither gains  nor loses an electron      7 which row shows the properties for an ionic compound?     volatility electrical conductivity  when solid  a high good  b high poor  c low good  d low poor     ",
            "4": "4  \u00a9 ucles 2021 0620/12/o/n/21  8 which substance is described as a macromolecule?  a ammonia  b g r a p h i t e   c iron  d sodium chloride      9 the formula of sodium chlorate( v) is nac l o3.    what is the relative formula mass of sodium chlorate( v), nac l o3?  a 52.0 b 74.5 c 106.5 d 223.5    10 iron can be electroplated with zinc to make it resistant to cor rosion.    which row about electroplating iron with zinc is correct?     positive electrode  (anode) negative electrode  (cathode) electrolyte  a iron zinc iron nitrate  b iron zinc zinc nitrate  c zinc iron iron nitrate  d zinc iron zinc nitrate      11 an energy level diagram for the reaction between substance x an d substance y to form  substance z is shown.    x + yz energy progress of reaction    which statement is correct?  a energy is released as substance z is formed.  b substance z has more energy than substance x and substance y.  c the reaction is exothermic.  d when substance x and substance y react, the temperature increas es.     ",
            "5": "5     \u00a9 ucles 2021 0620/12/o/n/21 [turn over  12 which reactions are exothermic?    1 c  +  o 2  \uf0ae  co 2  2 ch 4  +  2o 2  \uf0ae  co 2  +  2h 2o  3 2h 2  +  o 2  \uf0ae  2h 2o    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     13 solid copper( ii) carbonate reacts with dilute sulfuric acid.    cuco 3  +  h 2so 4  \uf0ae  cuso 4  +  co 2  +  h 2o    the rate of the reaction can be changed by varying the conditio ns.    which changes always increase the rate of this chemical reactio n?    1 increasing the concentration of sulfuric acid  2 increasing the size of the pieces of copper( ii) carbonate  3 increasing the temperature  4 increasing the volume of sulfuric acid    a 1, 3 and 4 b 1 and 3 only c 2 and 3 d 3 and 4 only     14 when a piece of marble is added to hydrochloric acid, bubbles o f carbon dioxide gas are given  off.    which method is used to find the rate of the reaction?  a counting the number of gas bubbles formed  b measuring the diameter of the gas bubbles  c measuring the speed at which the gas bubbles rise upwards thro ugh the acid  d measuring the time taken for 10  cm3 of gas to be collected    15 solid x is heated strongly.    the colour of the solid changes from blue to white.    what is solid x?  a anhydrous cobalt( ii) chloride  b calcium carbonate  c hydrated copper( ii) sulfate  d lead( ii) bromide     ",
            "6": "6  \u00a9 ucles 2021 0620/12/o/n/21  16 what happens to a chemical substance when it is reduced?  a it burns.  b it decomposes.  c it loses oxygen.  d it gains mass.      17 which statements about acids and bases are correct?    1 an acid reacts with a metal to give off hydrogen.  2 a base reacts with an ammonium salt to give off ammonia.  3 an acid reacts with a carbonate to give off carbon dioxide.  4 alkaline solutions are orange in methyl orange.    a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4     18 oxide 1 is a solid that reacts with dilute hydrochloric acid.    oxide 2 is a gas that reacts with sodium hydroxide solution.    what are the formulae of the oxides?     oxide 1 oxide 2  a cao mgo  b mgo no 2  c no 2 s o 2  d so 2 c a o      19 in the preparation of zinc sulfate crystals, excess zinc oxide is added to dilute sulfuric acid.    why is an excess of zinc oxide added?  a to make sure crystals are formed and not powder  b to avoid filtering the mixture  c to use up all of the sulfuric acid  d to use up all of the zinc oxide     ",
            "7": "7     \u00a9 ucles 2021 0620/12/o/n/21 [turn over  20 which statement about aqueous sodium hydroxide is correct?  a when it is added to a solution containing sulfate ions, a white  precipitate is formed.  b when it is added to a solution of copper( ii) ions, a blue precipitate is formed which dissolves  in excess to give deep blue solution.  c when it is added to a solution of iron( ii) ions, a green precipitate is formed which does not  dissolve in excess.  d when it is added to ammonium chloride, a gas is produced which turns blue litmus red.      21 a period of the periodic table is shown.    group i ii iii iv v vi vii viii  element r s t v w x y z    the letters are not their chemical symbols.    which statement is correct?  a element r does not conduct electricity.  b elements r and y react together to form an ionic compound.  c element z exists as a diatomic molecule.  d element z reacts with element t.      22 which statement about the elements in group vii of the periodic  table is correct?  a chlorine can displace bromine from bromides.  b group vii elements are all solids at room temperature.  c group vii elements occur as monoatomic covalent molecules.  d reactivity increases down group vii.     23 part of the periodic table is shown.    which element is a transition element?    a b dc      ",
            "8": "8  \u00a9 ucles 2021 0620/12/o/n/21  24 the noble gases are in group viii of the periodic table.    which statement explains why noble gases are unreactive?  a they all have eight electrons in their outer shells.  b they all have full outer shells.  c they are all gases.  d they are all monoatomic.     25 which statement is correct for all metals?  a they conduct electricity when molten.  b they gain electrons when they form ions.  c they have a low density.  d they have a low melting point.    26 which row describes the method of extraction of aluminium and i ron from their ores?     aluminium iron  a electrolysis electrolysis  b electrolysis reduction with carbon  c reduction with carbon electrolysis  d reduction with carbon reduction with carbon      27 which statement about metals and their uses is correct?  a aluminium is used to make food containers because it is resist ant to corrosion.  b aluminium is used to make aircraft wings because it is strong and has a high density.  c iron is used to make electrical wires because it is a good ins ulator of electricity.  d iron is used to make cooking utensils because it is easily rec ycled.     ",
            "9": "9     \u00a9 ucles 2021 0620/12/o/n/21 [turn over  28 the diagrams show some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treat ed?  a 1 only b 2 only c 3 only d 1, 2 and 3    29 four different test-tubes containing water and an iron nail ar e left for two weeks.    which nail showed the least amount of rusting?    a tap waterb boiled tap waterc boiled tap waterd tap water      30 which process does not produce a greenhouse gas?  a acid rain on limestone buildings  b combustion of wood  c digestion in cows  d zinc reacting with sulfuric acid    ",
            "10": "10  \u00a9 ucles 2021 0620/12/o/n/21  31 sulfur burns to make sulfur dioxide.    which row describes a source of sulfur and a use of sulfur diox ide?     source of sulfur use of sulfur dioxide  a the air food preservative  b the air treating acidic soils  c underground deposits food preservative  d underground deposits treating acidic soils     32 lime (calcium oxide) is used to treat waste water from a facto ry.    which substance is removed by the lime?  a ammonia  b sodium chloride  c sodium hydroxide  d s u l f u r i c  a c i d     33 a chemical equation for the complete combustion of methane is s hown.    2ch 4  +  zo2  \uf0ae  2co 2  +  4h 2o    what is the value of z?  a 2  b 3  c 4  d 6       34 fuel x produces carbon dioxide and water when it is burned in air. so does fuel y.    what could x and y be?     x  y   a c h 2  b c c 8h18  c ch 4 h 2  d ch 4 c 8h18     ",
            "11": "11     \u00a9 ucles 2021 0620/12/o/n/21 [turn over  35 which substance is not a fossil fuel?  a ethanol  b gasoline  c kerosene  d methane      36 which compound belongs to a different homologous series to the others?    hch hoha hch hch hb oh hch hcoc oh hch hcoh hd ch hh       37 what is a property of aqueous ethanoic acid?  a it changes red litmus blue.  b it has a deep purple colour.  c it has a ph of less than 7.  d it reacts with a metal oxide to form carbon dioxide.      38 which statements about unsaturated hydrocarbons are correct?    1 they contain both single and double bonds.  2 they turn aqueous bromine from colourless to brown.  3 they can be manufactured by cracking.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     39 which substance is used to produce alcohol by fermentation?  a phosphoric acid  b platinum  c iron  d y e a s t     ",
            "12": "12  \u00a9 ucles 2021 0620/12/o/n/21  40 which statements are correct?    1 polymers are large molecules built up from monomers.  2 proteins are natural polymers.  3 proteins and carbohydrates are constituents of food.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    ",
            "13": "13     \u00a9 ucles 2021 0620/12/o/n/21  blank page",
            "14": "14  \u00a9 ucles 2021 0620/12/o/n/21  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/12/o/n/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/12/o/n/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w21_qp_13.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 11_0620_13/2rp   \u00a9 ucles 2021   [turn ove r   *4993624638 *cambridge igcse\u2122       chemistry 0620/13     paper 1 multiple choice (core)  october/november 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/13/o/n/21  1 the particles in a substance are far apart, randomly arranged a nd moving.    the substance changes state and the particles are now close tog ether. the particles are still  randomly arranged and able to move.    what is the change of state of the substance?  a gas to liquid  b liquid to gas  c liquid to solid  d solid to gas      2 a student put exactly 25.00  cm3 of dilute hydrochloric acid into a conical flask.    the student added 2.5  g of solid sodium carbonate and measured the change in temperat ure of  the mixture.    which apparatus does the student need to use?  a balance, measuring cylinder, thermometer  b balance, pipette, stopwatch  c balance, pipette, thermometer  d burette, pipette, thermometer     3 a student separates sugar from pieces of broken glass by disso lving the sugar in water and  filtering off the broken glass.    filtrate     what is the filtrate?  a broken glass only  b broken glass and sugar solution  c pure water  d sugar solution    ",
            "3": "3     \u00a9 ucles 2021 0620/13/o/n/21 [turn over  4 the nucleus of a particular atom consists of nineteen particles .    nine of them are positively charged and ten of them are uncharg ed.    which statement about this nucleus is correct?  a the nucleus has a nucleon number of nine.  b the nucleus has a nucleon number of ten.  c the nucleus has a proton number of nine.  d the nucleus has a proton number of ten.    5 which description of brass is correct?  a alloy  b compound  c element  d non-metal    6 a group i element combines with a group vii element and forms a n ionic bond.    which row shows how the electronic structures change?     group i element group vii element  before  bonding after  bonding before  bonding after  bonding  a 2,8,1 2,8,2 2,7 2,6  b 2,8 2,7 2,8 2,8,1  c 2,8,1 2,8 2,7 2,8  d 2,8 2,8,1 2,8 2,7     ",
            "4": "4  \u00a9 ucles 2021 0620/13/o/n/21  7 four covalent compounds are listed.    chlorine  methane  ammonia  water    which row identifies the total number of covalent bonds in each  compound?     chlorine methane ammonia water  a 2 4 3 2  b 1 3 2 2  c 2 3 2 3  d 1 4 3 2     8 magnesium reacts with dilute hydrochloric acid to produce a sal t and hydrogen gas.    what is the equation for this reaction?  a mg  +  hc l  \uf0ae  mgc l  +  h  b mg  +  h 2cl 2  \uf0ae  mgc l 2  +  h 2  c mg  +  2hc l  \uf0ae  mgc l 2  +  h 2  d mg  +  2hc l  \uf0ae  mgc l 2  +  2h      9 the formula of sodium chlorate( v) is nac l o3.    what is the relative formula mass of sodium chlorate( v), nac l o3?  a 52.0 b 74.5 c 106.5 d 223.5     10 effervescence is observed at the negative electrode (cathode) d uring the electrolysis of  concentrated aqueous sodium chloride.    which element is produced at the negative electrode (cathode)?  a chlorine  b hydrogen  c oxygen  d s o d i u m     ",
            "5": "5     \u00a9 ucles 2021 0620/13/o/n/21 [turn over  11 the energy level diagram for a chemical reaction is shown.    energy progress of reactionreactantsproducts     which statement about this reaction is correct?  a the reaction is endothermic and energy is given out to the sur roundings.  b the reaction is endothermic and energy is taken in from the su rroundings.  c the reaction is exothermic and energy is given out to the surr oundings.  d the reaction is exothermic and energy is taken in from the sur roundings.    12 which property explains why methane is used as a fuel?  a it is an alkane.  b it forms carbon dioxide when it burns.  c it is a gas at room temperature.  d it releases heat energy when it burns.     13 solid copper( ii) carbonate reacts with dilute sulfuric acid.    cuco 3  +  h 2so 4  \uf0ae  cuso 4  +  co 2  +  h 2o    the rate of the reaction can be changed by varying the conditio ns.    which changes always increase the rate of this chemical reactio n?    1 increasing the concentration of sulfuric acid  2 increasing the size of the pieces of copper( ii) carbonate  3 increasing the temperature  4 increasing the volume of sulfuric acid    a 1, 3 and 4 b 1 and 3 only c 2 and 3 d 3 and 4 only    ",
            "6": "6  \u00a9 ucles 2021 0620/13/o/n/21  14 magnesium carbonate and hydrochloric acid react to form a gas.     the volume of gas is measured at fixed time intervals.    in experiment 1, an excess of magnesium carbonate granules reac ts with 100  cm3 o f   hydrochloric acid.    the experiment is repeated but with one change. this is experim ent 2.    the results are shown on the graph.    volume of gas 0 0 timeexperiment 2experiment 1     which change is made?  a a catalyst is added.  b magnesium carbonate powder is used.  c the hydrochloric acid is more concentrated.  d the temperature is lower.      15 which colour change is observed when water is added to anhydro us cobalt( ii) chloride?  a blue to pink  b pink to blue  c blue to white  d white to blue      16 the equation for the extraction of iron from its ore is shown.    fe2o3  +  3co  \uf0ae  2fe  +  3co 2    which statement is correct?  a iron is oxidised.  b iron( iii) oxide is oxidised.  c carbon monoxide is oxidised.  d carbon monoxide is reduced.   ",
            "7": "7     \u00a9 ucles 2021 0620/13/o/n/21 [turn over  17 solution x is tested separately with sodium carbonate and litm us.    which row shows that x is acidic?     sodium carbonate litmus  a effervescence blue  b effervescence red  c no change blue  d no change red     18 basic oxides are neutralised by acidic oxides.    which element forms an oxide that neutralises calcium oxide?  a hydrogen  b magnesium  c sodium  d sulfur     19 which method produces a pure sample of copper( ii) sulfate crystals?  a add an excess of copper( ii) carbonate to dilute sulfuric acid, filter and evaporate the f iltrate  until crystals start to appear.  b add an excess of copper( ii) carbonate to dilute sulfuric acid, filter off the remaining s olid and  dry it in an oven at 100  \uf0b0c.  c warm an excess of copper( ii)  o x i d e  w i t h  d i l u t e  s u l f u r i c  a c i d  a n d  e v a p o r a t e  t h e  m i x t u r e  t o  dryness.  d warm an excess of copper( ii) oxide with dilute sulfuric acid and filter off the crystals f ormed.      20 which statement about aqueous sodium hydroxide is correct?  a when it is added to a solution containing sulfate ions, a white  precipitate is formed.  b when it is added to a solution of copper( ii) ions, a blue precipitate is formed which dissolves  in excess to give deep blue solution.  c when it is added to a solution of iron( ii) ions, a green precipitate is formed which does not  dissolve in excess.  d when it is added to ammonium chloride, a gas is produced which turns blue litmus red.    ",
            "8": "8  \u00a9 ucles 2021 0620/13/o/n/21  21 a period of the periodic table is shown.    group i ii iii iv v vi vii viii  element r s t v w x y z    the letters are not their chemical symbols.    which statement is correct?  a element r does not conduct electricity.  b elements r and y react together to form an ionic compound.  c element z exists as a diatomic molecule.  d element z reacts with element t.      22 lithium, sodium and potassium are elements in group i of the pe riodic table.    which statement about sodium is correct?  a sodium is more dense than potassium.  b sodium reacts with water more  vigorously than lithium.  c sodium has a lower melting point than potassium.  d solid sodium does not conduct electricity.      23 which property of transition elements is different from the pro perties of group i metals?  a they conduct electricity.  b they are malleable.  c they form coloured compounds.  d they form basic oxides.     24 the noble gases are in group viii of the periodic table.    which statement explains why noble gases are unreactive?  a they all have eight electrons in their outer shells.  b they all have full outer shells.  c they are all gases.  d they are all monoatomic.    ",
            "9": "9     \u00a9 ucles 2021 0620/13/o/n/21 [turn over  25 which statement is correct for all metals?  a they conduct electricity when molten.  b they gain electrons when they form ions.  c they have a low density.  d they have a low melting point.      26 chromium is a more reactive metal than iron but less reactive t han zinc.    which statements are correct?    1 chromium does not react with dilute hydrochloric acid.  2 chromium oxide is reduced when it is heated with carbon. 3 chromium reacts with zinc oxide to form zinc. 4 chromium reacts with steam to form hydrogen gas.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     27 some properties of copper are listed.    1 it conducts electricity.  2 it conducts heat.  3 it is ductile. 4 it has a high melting point.    which properties of copper make it useful as a cooking pan?  a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4      28 the diagrams show some uses of water in the home.    1 2 3    for which uses is it important for the water to have been treat ed?  a 1 only b 2 only c 3 only d 1, 2 and 3    ",
            "10": "10  \u00a9 ucles 2021 0620/13/o/n/21  29 which gas is released when slaked lime, ca(oh) 2, is added to a field that has previously been  treated with ammonium sulfate fertiliser?  a ammonia  b carbon dioxide  c nitrogen  d sulfur dioxide     30 which reactions produce carbon dioxide?    1 heating a carbonate  2 reacting a carbonate with dilute acid  3 burning methane 4 cracking a hydrocarbon    a 1, 2 and 3 b 1, 2 and 4 c 2, 3 and 4 d 3 and 4 only      31 sulfur burns to make sulfur dioxide.    which row describes a source of sulfur and a use of sulfur diox ide?     source of sulfur use of sulfur dioxide  a the air food preservative  b the air treating acidic soils  c underground deposits food preservative  d underground deposits treating acidic soils     32 lime (calcium oxide) is used to treat waste water from a facto ry.    which substance is removed by the lime?  a ammonia  b sodium chloride  c sodium hydroxide  d s u l f u r i c  a c i d     ",
            "11": "11     \u00a9 ucles 2021 0620/13/o/n/21 [turn over  33 the structures of three chemical compounds are shown.    hch hch h hc1 hch hoh2 hch hch hh3     to which homologous series do 1, 2 and 3 belong?     1  2  3   a alkane alcohol alkene  b alkene alkane alcohol  c alkane alkene alcohol  d alkene alcohol alkane     34 fuel x produces carbon dioxide and water when it is burned in air. so does fuel y.    what could x and y be?     x  y   a c h 2  b c c 8h18  c ch 4 h 2  d ch 4 c 8h18     35 what is the main constituent of natural gas?  a hydrogen  b carbon monoxide  c methane  d nitrogen    36 which statement describes the members of a homologous series?  a compounds with the same physical properties  b compounds containing the same functional group  c compounds containing the same number and type of bonds  d compounds obtained from the same raw material    ",
            "12": "12  \u00a9 ucles 2021 0620/13/o/n/21  37 which monomer molecules are used to make poly(ethene)?  a c 2h4 b c 2h6 c c 3h6 d c 4h8    38 ethanol is manufactured by the catalytic addition of steam to c ompound p.    what is p?  a ethane  b ethene  c methane  d y e a s t     39 which property is shown by aqueous ethanoic acid?  a it reacts with magnesium to form water.  b it turns red litmus blue.  c it reacts with copper to form hydrogen gas.  d it reacts with copper( ii) carbonate to form carbon dioxide gas.      40 which statement about polymers is correct?  a all synthetic polymers rapidly break down in landfill sites.  b nylon is a natural polymer.  c proteins are non-biodegradable natural polymers.  d synthetic polymers are harmful to marine life.    ",
            "13": "13     \u00a9 ucles 2021 0620/13/o/n/21  blank page",
            "14": "14  \u00a9 ucles 2021 0620/13/o/n/21  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/13/o/n/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/13/o/n/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w21_qp_21.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 11_0620_21/2rp   \u00a9 ucles 2021   [turn ove r   *3450275905*cambridge igcse\u2122       chemistry 0620/21     paper 2 multiple choice (extended)  october/november 2021     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \u2022 there are forty  questions on this paper. answer all questions.   \u2022 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice answer sheet.   \u2022 follow the instructions on the mu ltiple choice answer sheet.  \u2022 write in soft pencil.  \u2022 write your name, centre number and candidate number on the multiple choice answer sheet in the spaces provided unless this has been done for you.  \u2022 do not use correction fluid.  \u2022 do not write on any bar codes.  \u2022 you may use a calculator.      information  \u2022 the total mark for this paper is 40.  \u2022 each correct answer will score one mark.  \u2022 any rough working should be done on this question paper.  \u2022 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/21/o/n/21  1 decane has a freezing point of \u201330  \u00b0c and a boiling point of 174  \u00b0c.    a small sample of decane is placed in an open beaker in an oven at a temperature of 120  \u00b0c and  at atmospheric pressure for 24 hours.    what happens to the sample of decane?  a it boils.  b it evaporates.  c it melts.  d it sublimes.     2 a student put exactly 25.00  cm3 of dilute hydrochloric acid into a conical flask.    the student added 2.5  g of solid sodium carbonate and measured the change in temperature of  the mixture.    which apparatus does the student need to use?  a balance, measuring cylinder, thermometer  b balance, pipette, stopwatch  c balance, pipette, thermometer  d burette, pipette, thermometer     3 a student separates sugar from pieces of broken glass by dissolving the sugar in water and  filtering off the broken glass.    filtrate     what is the filtrate?  a broken glass only  b broken glass and sugar solution  c pure water  d sugar solution     ",
            "3": "3     \u00a9 ucles 2021 0620/21/o/n/21 [turn over  4 which statement explains why metals conduct electricity when solid?  a they have atoms which are free to move.  b they have electrons which are free to move.  c they have molecules which are free to move.  d they have positive ions which are free to move.      5 which description of brass is correct?  a alloy  b compound  c element  d non-metal      6 the equation for the reaction of iron( iii) oxide with carbon monoxide is shown.    fe2o3(s)  +  3co(g)  \u2192  2fe(s)  +  3co 2(g)    what is the maximum mass of iron that can be made from 480  g of iron( iii) oxide?  a 56  g b 112  g c 168  g d 336  g      7 which statement describes the attractive forces between molecules?  a they are strong covalent bonds which hold molecules together.  b they are strong ionic bonds which hold molecules together.  c they are weak forces formed between covalently-bonded molecules.  d they are weak forces which hold ions together in a lattice.      8 which statement about carbon is correct?  a diamond and graphite both have simple molecular structures.  b diamond and graphite are both used to make cutting tools.  c each carbon atom in diamond is bonded to three other carbon atoms.  d graphite conducts electricity and has a giant covalent structure.      9 the formula of an aluminium ion is a l 3+.    what is the formula of aluminium sulfate?  a a l 2so 4 b al (so 4)2 c a l 2(so 4)3 d al 3(so 4)2     ",
            "4": "4  \u00a9 ucles 2021 0620/21/o/n/21  10 which statements about the products of electrolysis, using inert electrodes, are correct?    1 when molten lead( ii) bromide is electrolysed, bromine is formed at the cathode.  2 when dilute sulfuric acid is electrolysed, oxygen is formed at the anode.  3 when concentrated aqueous sodium chloride is electrolysed, sodium is formed at  the cathode.  4 when concentrated hydrochloric acid is electrolysed, chlorine is formed at the  anode.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     11 chlorine reacts with ethane to produce chloroethane and hydrogen chloride.    ch hhh c hc lcl cl cl ++ h ch hhh c hh     the reaction is exothermic.    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013c l +340  c\u2013c +350  c\u2013h +410  cl \u2013c l +240  h\u2013c l +430    what is the energy change for the reaction?  a \u20131420  kj / mol  b \u2013120  kj / mol  c +120  kj / mol  d +1420  kj / mol     ",
            "5": "5     \u00a9 ucles 2021 0620/21/o/n/21 [turn over  12 hydrogen is used as a fuel in rockets and is also used in hydrogen fuel cells.    which statements are correct?    1 both uses produce water vapour.  2 burning hydrogen produces polluting gases. 3 a fuel cell produces electricity.    a 1, 2 and 3 b 1 and 3 only c 1 only d 2 and 3 only      13 which statements about the effect of increasing the temperature on the rate of a reaction are correct?    1 it increases the rate of a reaction.  2 it increases the activation energy.  3 it increases the frequency of collisions.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only      14 ammonia is made by reacting nitrogen with hydrogen.    the equation for the reaction is shown.    n 2(g)  +  3h 2(g)    2nh 3(g)    the forward reaction is exothermic.    which changes in temperature and pressure decrease the yield of ammonia?     temperature pressure  a decrease decrease  b decrease increase  c increase decrease  d increase increase    ",
            "6": "6  \u00a9 ucles 2021 0620/21/o/n/21  15 x is a pink solid.    y is a blue solid.    when x is heated, water is produced and the solid turns blue.    when water is added to y, the solid turns pink.    what are x and y?     x y  a anhydrous cobalt( ii) chloride hydrated cobalt( ii) chloride  b hydrated cobalt( ii) chloride anhydrous cobalt( ii) chloride  c anhydrous copper( ii) sulfate hydrated copper( ii) sulfate  d hydrated copper( ii) sulfate anhydrous copper( ii) sulfate      16 iron( ii) chloride solution reacts with chlorine gas.    the equation is shown.    2fec l 2(aq)  +  c l 2(g)  \u2192  2fec l 3(aq)    which statements about this reaction are correct?    1 fe2+ ions are reduced to fe3+ ions.  2 chlorine acts as a reducing agent.  3 fe2+ ions each lose an electron.  4 c l 2 molecules are reduced to c l \u2013 ions.    a 1 and 2 b 2 and 3 c 2 and 4 d 3 and 4      17 which row describes the properties of an acid?     property 1 property 2  a proton acceptor ph less than 7  b proton acceptor ph more than 7  c proton donor ph less than 7  d proton donor ph more than 7     ",
            "7": "7     \u00a9 ucles 2021 0620/21/o/n/21 [turn over  18 which element forms an amphoteric oxide?  a aluminium  b carbon  c magnesium  d silicon      19 copper( ii) chloride crystals are made by adding solid copper( ii) carbonate to dilute  hydrochloric acid until no more dissolves.    which process is used to obtain pure copper( ii) chloride crystals from the mixture?  a distillation of the mixture  b evaporation of the mixture  c filtration followed by drying of the residue  d filtration followed by evaporation of the filtrate     20 moving from right to left across the periodic table the elements show increasing metallic character.    why does metallic character increase from right to left across a period?  a the atoms have more electrons in their outer shells.  b the atoms more readily gain electrons to form negative ions.  c the atoms more readily lose electrons to form positive ions.  d the charge on the nucleus of each atom gets larger.     21 a period of the periodic table is shown.    group i ii iii iv v vi vii viii  element r s t v w x y z    the letters are not their chemical symbols.    which statement is correct?  a element r does not conduct electricity.  b elements r and y react together to form an ionic compound.  c element z exists as a diatomic molecule.  d element z reacts with element t.     ",
            "8": "8  \u00a9 ucles 2021 0620/21/o/n/21  22 group vii elements show trends in their physical properties going down the group.    element x y z  chlorine \u2013101 \u201334 0.003  bromine \u20137 59 3.1  iodine 114 184 4.9    which row shows the missing headings for the properties in the table?     x y z  a density in g  / cm3 boiling point in \u00b0c melting point in \u00b0c  b melting point in \u00b0c boiling point in \u00b0c density in g  / cm3  c boiling point in \u00b0c density in g  / cm3 melting point in \u00b0c  d boiling point in \u00b0c melting point in \u00b0c density in g  / cm3     23 some properties of two metals, g and h, are shown.    metal g metal h  the formula of the chloride is gc l high melting point  reacts with cold water has more than one oxidation state    which row about metals g and h is correct?     metal g metal h  a in group i of the periodic table in group ii of the periodic table  b in group i of the periodic table transition metal  c in group ii of the periodic table in group i of the periodic table  d in group ii of the periodic table transition metal    24 the noble gases are in group viii of the periodic table.    which statement explains why noble gases are unreactive?  a they all have eight electrons in their outer shells.  b they all have full outer shells.  c they are all gases.  d they are all monoatomic.     ",
            "9": "9     \u00a9 ucles 2021 0620/21/o/n/21 [turn over  25 which statement is correct for all metals?  a they conduct electricity when molten.  b they gain electrons when they form ions.  c they have a low density.  d they have a low melting point.      26 which statement about the extraction of metals is correct?  a aluminium is extracted from the ore bauxite by electrolysis.  b aluminium is extracted from the ore hematite by electrolysis.  c iron is extracted from the ore bauxite by electrolysis.  d iron is extracted from the ore hematite by electrolysis.      27 aluminium objects do not need protection from corrosion.    iron objects must be protected from corrosion.    which statement explains why aluminium resists corrosion?  a aluminium does not form ions easily.  b aluminium does not react with water or air.  c aluminium has a protective oxide layer.  d aluminium is below iron in the reactivity series.      28 which statements about the thermal decomposition of copper( ii) nitrate are correct?    1 a brown gas is given off.  2 a gas which relights a glowing splint is given off. 3 the solid residue is an acidic oxide.    a 1 only b 1 and 2 c 1 and 3 d 2 and 3     ",
            "10": "10  \u00a9 ucles 2021 0620/21/o/n/21  29 covering iron with zinc prevents the iron from rusting even when the zinc is scratched.    covering iron with tin prevents the iron from rusting, but when the tin is scratched the iron  underneath starts to rust.    which statement is correct?  a both tin and zinc prevent iron from rusting by sacrificial protection.  b both tin and zinc prevent iron from rusting by stopping water and carbon dioxide reaching the  iron.  c tin is more reactive than iron and prevents iron from rusting until it is scratched.  d zinc loses electrons more easily than iron a nd prevents iron from rusting by corroding first.     30 which statements about the haber process are correct?    1 one of the raw materials is extracted fr om liquid air by fractional distillation.  2 one of the raw materials is produced by the reaction of steam and methane.  3 the catalyst for the haber process is vanadium( v) oxide.    a 1 only b 1 and 2 only c 2 and 3 only d 1, 2 and 3      31 which raw material is used in the contact process?  a air  b ammonia  c carbon  d nitrogen     32 lime (calcium oxide) is used to treat waste water from a factory.    which substance is removed by the lime?  a ammonia  b sodium chloride  c sodium hydroxide  d sulfuric acid     ",
            "11": "11     \u00a9 ucles 2021 0620/21/o/n/21 [turn over  33 an alkane molecule of molecular formula c 8h18 undergoes cracking. the equation for the  reaction is shown.    c8h18  \u2192  q  +  2r    substance r has two carbon atoms per molecule and decolourises aqueous bromine.    what is substance q?  a butane  b butene  c ethane  d ethene     34 fuel x produces carbon dioxide and water when it is burned in air. so does fuel y.    what could x and y be?     x y  a c h 2  b c c 8h18  c ch 4 h 2  d ch 4 c 8h18    35 which molecule contains only single covalent bonds?  a propane  b propanoic acid  c propene  d propyl propanoate      36 alkanes react with chlorine to form chloroalkanes.    which statement about the reactions of alkanes with chlorine is correct?  a alkanes react with chlorine by addition.  b the gaseous product turns red litmus blue.  c the chlorine atom in chloroethane is covalently bonded.  d the general formula of the chloroalkanes is c nh2ncl.     ",
            "12": "12  \u00a9 ucles 2021 0620/21/o/n/21  37 part of the structure of a very large molecule is shown.    ch hch hch coh ohch hch oh hch hcoh h    which term describes the small unit used to make this molecule?  a hydrocarbon  b monomer  c polymer  d saturated     38 propene reacts with steam to form propanol.    c 3h6(g)  +  h 2o(g)  \u2192  c3h7oh(g)    which type of reaction takes place?  a addition  b condensation  c oxidation  d substitution      39 which statement about aqueous ethanoic acid is correct?  a it reacts with magnesium to produce a salt and hydrogen.  b it reacts with sodium hydroxide to produce a salt and hydrogen.  c it reacts with ammonium salts to produce ammonia.  d it turns red litmus blue.     ",
            "13": "13     \u00a9 ucles 2021 0620/21/o/n/21  40 the diagram shows the partial structure of terylene .    co c co o o oo    from which pair of compounds is it made?    co co ho oh ho oh+ co co ho oh co co ho oh co co ho ohho oh a co ho oh + co ho oh b + c + d     ",
            "14": "14  \u00a9 ucles 2021 0620/21/o/n/21  blank page",
            "15": "15       permission to reproduce items where third-party owned material pr otected by copyright is included has been sought and cleared w here possible. every  reasonable effort has been made by the publisher (ucles) to trac e copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends  at the earliest possible opportunity.    to avoid the issue of disclosure of ans wer-related information to candidates, all copyright acknowledgements are reproduced onl ine in the cambridge  assessment international education copyright  acknowledgements booklet. this is produced  for each series of examinations and is freely available to download  at www.cambridgeinternational.org after the live examination series.  cambridge assessment international education is part of the ca mbridge assessment group. cambri dge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which it self is a department of the university of cambridge.    \u00a9 ucles 2021 0620/21/o/n/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/21/o/n/21   groupthe periodic t able of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w21_qp_22.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib21 11_0620_22/3rp   \u00a9 ucles 2021   [turn ove r   *8181221372*cambridge igcse\u2122       chemistry 0620/22     paper 2 multiple choice (extended)  october/november 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/22/o/n/21  1 an experiment is set up as shown.    cotton wool soaked in ammoniacotton wool soaked in hydrochloric acid     after several minutes, a white ring of ammonium chloride appear s as shown.    ammonium chloride     which statement explains the observation after several minutes?   a ammonia gas diffuses faster than hydrogen chloride gas because its molecules have a lower  molecular mass.  b ammonia gas diffuses faster than hydrogen chloride gas because its molecules have a  higher molecular mass.  c ammonia gas diffuses slower than hydrogen chloride gas because its molecules have a  lower molecular mass.  d ammonia gas diffuses slower than hydrogen chloride gas because its molecules have a  higher molecular mass.     2 a student put exactly 25.00  cm3 of dilute hydrochloric acid into a conical flask.    the student added 2.5  g of solid sodium carbonate and measured the change in temperat ure of  the mixture.    which apparatus does the student need to use?  a balance, measuring cylinder, thermometer  b balance, pipette, stopwatch  c balance, pipette, thermometer  d burette, pipette, thermometer    ",
            "3": "3     \u00a9 ucles 2021 0620/22/o/n/21 [turn over  3 a student separates sugar from pieces of broken glass by disso lving the sugar in water and  filtering off the broken glass.    filtrate     what is the filtrate?  a broken glass only  b broken glass and sugar solution  c pure water  d sugar solution     4 how many protons, neutrons and electrons are there in one atom of the isotope  27 13al?     protons neutrons electrons  a 13 13 13  b 13 14 13  c 14 13 13  d 14 14 13      5 which description of brass is correct?  a alloy  b compound  c element  d non-metal    ",
            "4": "4  \u00a9 ucles 2021 0620/22/o/n/21  6 some properties of diamond are shown.    1 it is very hard.  2 every atom forms four bonds.  3 it does not conduct electricity.    which properties are also shown by silicon( iv) oxide?  a 1 only b 1 and 2 c 1 and 3 d 2 and 3     7 which statement describes the attractive forces between molecu les?  a they are strong covalent bonds which hold molecules together.  b they are strong ionic bonds which hold molecules together.  c they are weak forces formed between covalently-bonded molecules .  d they are weak forces which hold ions together in a lattice.     8 which substance is described as a macromolecule?  a ammonia  b g r a p h i t e   c iron  d sodium chloride    9 the equation for the reaction of sodium with water is shown.    2na  +  2h 2o  \uf0ae  2naoh  +  h 2    what is the volume of hydrogen gas, measured at r.t.p., produce d when 18.4  g of sodium reacts  with excess water?  a 9 . 6  dm3 b 1 5 . 0  dm3 c 1 9 . 2  dm3 d 30.0  dm3     10 iron can be electroplated with zinc to make it resistant to cor rosion.    which row about electroplating iron with zinc is correct?     positive electrode  (anode) negative electrode  (cathode) electrolyte  a iron zinc iron nitrate  b iron zinc zinc nitrate  c zinc iron iron nitrate  d zinc iron zinc nitrate ",
            "5": "5     \u00a9 ucles 2021 0620/22/o/n/21 [turn over  11 chlorine reacts with ethane to produce chloroethane and hydrog en chloride.    ch hhh c hc lcl cl cl ++ h ch hhh c hh     the reaction is exothermic.    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013c l +340  c\u2013c +350  c\u2013h +410  cl \u2013c l +240  h\u2013c l +430    what is the energy change for the reaction?  a \u20131420  kj / mol  b \u2013120  kj / mol  c +120  kj / mol  d +1420  kj / mol     12 chlorine gas is bubbled into aqueous potassium iodide.    what is the ionic equation for the reaction that takes place?  a cl  +  i \u2013  \uf0ae  c l \u2013  +  i  b cl 2  +  2 i\u2013  \uf0ae  c l 2\u2013  +  i2  c cl 2  +  2 i\u2013  \uf0ae  2c l \u2013  +  i2  d cl 2  +  2 i\u2013  \uf0ae  2c l \u2013  +  2 i      13 concentrated aqueous sodium chloride is electrolysed.    which equation represents the reaction at the cathode?  a n a+  +  e\u2013  \uf0ae  na  b 2 o2\u2013  \uf0ae  o 2  +  4e\u2013  c 2 h+  +  2e\u2013  \uf0ae  h2  d 2 c l \u2013  \uf0ae  c l 2  +  2e\u2013 ",
            "6": "6  \u00a9 ucles 2021 0620/22/o/n/21  14 which statements about hydrogen are correct?    1 when hydrogen is burned, heat energy is released.  2 when hydrogen is used in a fuel cell, electrical energy is ge nerated.  3 when hydrogen is used as a fuel, water is the only product.    a 1, 2 and 3 b 1 and 2 only c 1  o n l y  d 3  o n l y     15 solid x is heated strongly.    the colour of the solid changes from blue to white.    what is solid x?  a anhydrous cobalt( ii) chloride  b calcium carbonate  c hydrated copper( ii) sulfate  d lead( ii) bromide      16 iron( ii) chloride solution reacts with chlorine gas.    the equation is shown.    2fec l 2(aq)  +  c l 2(g)  \uf0ae  2fec l 3(aq)    which statements about this reaction are correct?    1 fe2+ ions are reduced to fe3+ ions.  2 chlorine acts as a reducing agent. 3 fe 2+ ions each lose an electron.  4 c l 2 molecules are reduced to c l \u2013 ions.    a 1 and 2 b 2 and 3 c 2 and 4 d 3 and 4    17 which statements about acids and bases are correct?    1 an acid reacts with a metal to give off hydrogen.  2 a base reacts with an ammonium salt to give off ammonia.  3 an acid reacts with a carbonate to give off carbon dioxide. 4 alkaline solutions are orange in methyl orange.    a 1, 2 and 3 b 1, 2 and 4 c 1, 3 and 4 d 2, 3 and 4     ",
            "7": "7     \u00a9 ucles 2021 0620/22/o/n/21 [turn over  18 oxide 1 is a solid that reacts with dilute hydrochloric acid.    oxide 2 is a gas that reacts with sodium hydroxide solution.    what are the formulae of the oxides?     oxide 1 oxide 2  a cao mgo  b mgo no 2  c no 2 s o 2  d so 2 c a o       19 which reaction is a photochemical reaction?  a addition of bromine to propene  b esterification of ethanol and ethanoic acid  c oxidation of ethanol  d substitution of methane with chlorine    20 the equation shown represents a reaction at equilibrium.    m and n represent the balancing numbers for the reactant and pr oduct respectively.    mp(g)     nq(g)    a high temperature increases the concentration of q.    a high pressure increases the concentration of q.    which statement about the reaction is correct?  a the forward reaction is exothermic and m is greater than n.  b the forward reaction is exothermic and m is less than n.  c the forward reaction is endothermic and m is greater than n.  d the forward reaction is endothermic and m is less than n.    ",
            "8": "8  \u00a9 ucles 2021 0620/22/o/n/21  21 a period of the periodic table is shown.    group i ii iii iv v vi vii viii  element r s t v w x y z    the letters are not their chemical symbols.    which statement is correct?  a element r does not conduct electricity.  b elements r and y react together to form an ionic compound.  c element z exists as a diatomic molecule.  d element z reacts with element t.      22 all metal nitrates are soluble in water.    all metal chlorides are soluble except silver and lead.    all metal carbonates are insoluble except sodium and potassium.     which aqueous solutions produce a precipitate when mixed togeth er?    1 silver nitrate + sodium carbonate  2 silver nitrate + sodium chloride  3 barium nitrate + potassium chloride    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3    23 which row describes properties of transition elements?     property 1 property 2 property 3  a coloured compounds high density variable oxidation states  b high density high melting point one oxidation state  c high melting point coloured compounds one oxidation state  d low melting point high density variable oxidation states     ",
            "9": "9     \u00a9 ucles 2021 0620/22/o/n/21 [turn over  24 the noble gases are in group viii of the periodic table.    which statement explains why noble gases are unreactive?  a they all have eight electrons in their outer shells.  b they all have full outer shells.  c they are all gases.  d they are all monoatomic.     25 which statement is correct for all metals?  a they conduct electricity when molten.  b they gain electrons when they form ions.  c they have a low density.  d they have a low melting point.    26 carbon dioxide is produced during the extraction of aluminium f rom bauxite.    which statement describes how this carbon dioxide is made?  a carbon monoxide reduces aluminium oxide forming carbon dioxide and aluminium.  b carbon is burned in the blast furnace to release heat energy.  c oxygen made in the process reacts with the carbon electrode.  d the ore of aluminium undergoes thermal decomposition.    27 aluminium objects do not need protection from corrosion.    iron objects must be protected from corrosion.    which statement explains why aluminium resists corrosion?  a aluminium does not form ions easily.  b aluminium does not react with water or air.  c aluminium has a protective oxide layer.  d aluminium is below iron in the reactivity series.    ",
            "10": "10  \u00a9 ucles 2021 0620/22/o/n/21  28 which statements explain why zinc is used to protect iron from rusting?    1 zinc is more reactive than iron.  2 zinc is less reactive than iron.  3 zinc can form alloys with iron.  4 zinc acts as a sacrificial metal.    a 1 and 3  b  1 and 4  c  2 and 3  d  2 and 4     29 which conditions are used in the haber process?     temperature  /  \uf0b0c pressure  / atmospheres  a 100 10  b 450 10  c 450 200  d 1000 500      30 which process does not produce a greenhouse gas?  a acid rain on limestone buildings  b combustion of wood  c digestion in cows  d zinc reacting with sulfuric acid      31 which reaction involving sulfur dioxide is correct?  a it is produced during the extraction of zinc from zinc blende.  b it reacts with concentrated sulfuric acid to form oleum.  c it reacts with sulfur to form sulfur trioxide.  d it turns an acidified solution of potassium manganate( vii) purple.      32 lime (calcium oxide) is used to treat waste water from a facto ry.    which substance is removed by the lime?  a ammonia  b sodium chloride  c sodium hydroxide  d s u l f u r i c  a c i d    ",
            "11": "11     \u00a9 ucles 2021 0620/22/o/n/21 [turn over  33 what is the structure of the ester formed from ethanoic acid an d propanol?    a o oc ch hc hh h h ch hch hb o c ch hc hh h c o c ch hh ch h ch h h hc o hh h ch h o h d o oc ch hh h ch hch hch hc      34 fuel x produces carbon dioxide and water when it is burned in air. so does fuel y.    what could x and y be?     x  y   a c h 2  b c c 8h18  c ch 4 h 2  d ch 4 c 8h18     ",
            "12": "12  \u00a9 ucles 2021 0620/22/o/n/21  35 the structures of four organic molecules are shown.    hch hcl hch hch ho h hcoh hhhco h o     how many different homologous series are represented by these m olecules?  a 1  b 2  c 3  d 4      36 which statement about ethene is correct?  a it has the chemical formula c 2h6.  b it burns in excess oxygen producing carbon dioxide and water.  c it reacts with br 2 to produce an orange solution.  d it reacts with oxygen to form ethanol.    37 ethanol is manufactured by fermentation of sugars or by catalyt ic hydration of ethene.    which row states an advantage of each method?     fermentation hydration  a produces purer ethanol is a batch process  b produces purer ethanol is a continuous process  c uses a renewable resource is a batch process  d uses a renewable resource is a continuous process     38 which statements about unsaturated hydrocarbons are correct?    1 they contain both single and double bonds.  2 they turn aqueous bromine from colourless to brown. 3 they can be manufactured by cracking.    a 1 and 2 only b 1 and 3 only c 2 and 3 only d 1, 2 and 3     ",
            "13": "13     \u00a9 ucles 2021 0620/22/o/n/21  39 which polymers have the same linkage between monomer units?  a carbohydrate and polyamide  b carbohydrate and polyester  c protein and polyamide  d protein and polyester      40 the diagram shows the partial structure of terylene .    co c co o o oo    from which pair of compounds is it made?    co co ho oh ho oh+ co co ho oh co co ho oh co co ho ohho oh a co ho oh + co ho oh b + c + d     ",
            "14": "14  \u00a9 ucles 2021 0620/22/o/n/21  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/22/o/n/21  blank page  ",
            "16": "16  \u00a9 ucles 2021 0620/22/o/n/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w21_qp_23.pdf": {
            "1": "    this document has 16 pages.  ib21 11_0620_23/3rp   \u00a9 ucles 2021   [turn ove r   *1626974827*cambridge igcse\u2122       chemistry 0620/23     paper 2 multiple choice (extended)  october/november 2021     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 0620/23/o/n/21  1 brownian motion and the diffusion of gases provide evidence for  the particulate nature of matter.    which row identifies an example of brownian motion and how mole cular mass determines the  rate of diffusion of gas molecules?     brownian motion diffusion  a   pollen grains in water are  seen to move randomly heavier gas molecules  diffuse more quickly  b   pollen grains in water are  seen to move randomly lighter gas molecules  diffuse more quickly  c   salt dissolves faster in  hot water than in cold water heavier gas molecules  diffuse more quickly  d   salt dissolves faster in  hot water than in cold water lighter gas molecules  diffuse more quickly     2 a student put exactly 25.00  cm3 of dilute hydrochloric acid into a conical flask.    the student added 2.5  g of solid sodium carbonate and measured the change in temperat ure of  the mixture.    which apparatus does the student need to use?  a balance, measuring cylinder, thermometer  b balance, pipette, stopwatch  c balance, pipette, thermometer  d burette, pipette, thermometer    ",
            "3": "3     \u00a9 ucles 2021 0620/23/o/n/21 [turn over  3 a student separates sugar from pieces of broken glass by disso lving the sugar in water and  filtering off the broken glass.    filtrate     what is the filtrate?  a broken glass only  b broken glass and sugar solution  c pure water  d sugar solution     4 the nucleus of a particular atom consists of nineteen particles .    nine of them are positively charged and ten of them are uncharg ed.    which statement about this nucleus is correct?  a the nucleus has a nucleon number of nine.  b the nucleus has a nucleon number of ten.  c the nucleus has a proton number of nine.  d the nucleus has a proton number of ten.     5 which description of brass is correct?  a alloy  b compound  c element  d non-metal    ",
            "4": "4  \u00a9 ucles 2021 0620/23/o/n/21  6 a group i element combines with a group vii element and forms a n ionic bond.    which row shows how the electronic structures change?     group i element group vii element  before  bonding after  bonding before  bonding after  bonding  a 2,8,1 2,8,2 2,7 2,6  b 2,8 2,7 2,8 2,8,1  c 2,8,1 2,8 2,7 2,8  d 2,8 2,8,1 2,8 2,7      7 which statement describes the attractive forces between molecu les?  a they are strong covalent bonds which hold molecules together.  b they are strong ionic bonds which hold molecules together.  c they are weak forces formed between covalently-bonded molecules .  d they are weak forces which hold ions together in a lattice.    8 which diagram shows the outer electron arrangement in a molecu le of carbon dioxide?    oca o ocb o occ o ocd o       9 aluminium oxide is an ionic compound containing a l 3+ ions and o2\u2013 ions.    aluminium hydroxide is an ionic compound containing a l 3+ ions and oh\u2013 ions.    in which row are the formulae for aluminium oxide and aluminium  hydroxide correct?     aluminium  oxide aluminium  hydroxide  a al 2o3 a l (oh) 3  b al 3o2 a l oh 3  c al 2o3 a l oh 3  d al 3o2 a l (oh) 3     ",
            "5": "5     \u00a9 ucles 2021 0620/23/o/n/21 [turn over  10 effervescence is observed at the negative electrode (cathode) d uring the electrolysis of  concentrated aqueous sodium chloride.    which element is produced at the negative electrode (cathode)?  a chlorine  b hydrogen  c oxygen  d s o d i u m     11 the energy level diagram for a chemical reaction is shown.    energy progress of reactionreactantsproducts     which statement about this reaction is correct?  a the reaction is endothermic and energy is given out to the sur roundings.  b the reaction is endothermic and energy is taken in from the su rroundings.  c the reaction is exothermic and energy is given out to the surr oundings.  d the reaction is exothermic and energy is taken in from the sur roundings.    ",
            "6": "6  \u00a9 ucles 2021 0620/23/o/n/21  12 chlorine reacts with ethane to produce chloroethane and hydrog en chloride.    ch hhh c hc lcl cl cl ++ h ch hhh c hh     the reaction is exothermic.    the bond energies are shown in the table.    bond bond energy  in kj  / mol  c\u2013c l +340  c\u2013c +350  c\u2013h +410  cl \u2013c l +240  h\u2013c l +430    what is the energy change for the reaction?  a \u20131420  kj / mol  b \u2013120  kj / mol  c +120  kj / mol  d +1420  kj / mol     13 what is the concentration of the solution when 31.8  g of sodium carbonate, na 2co 3, is dissolved  in water to make a solution of 250  cm3?  a 0.075  mol  / dm3  b 0 . 3 0  mol  / dm3  c 1 . 2  mol  / dm3  d 1 . 5  mol  / dm3      14 a fuel cell is used to generate electricity.    which chemicals are used in a fuel cell?  a hydrogen and methane  b hydrogen and oxygen  c nitrogen and methane  d nitrogen and oxygen   ",
            "7": "7     \u00a9 ucles 2021 0620/23/o/n/21 [turn over  15 sulfuric acid is manufactured using the contact process. one o f the reactions is shown.    2so 2(g)  +  o 2(g)    2so 3(g)    the forward reaction is exothermic.    statement 1 the equation has more molecules on the left-hand si de than on the   right-hand side.  statement 2 using a higher pressure shifts the equilibrium to t he left.  statement 3 higher temperatures increase the rate of reaction.  statement 4 increasing the temperature shifts the equilibrium t o the right.    which alternative is correct?  a statement 1 is correct and explains statement 2.  b statement 1 and statement 3 are correct.  c statement 2 and statement 4 are correct.  d statement 3 is correct and explains statement 4.      16 iron( ii) chloride solution reacts with chlorine gas.    the equation is shown.    2fec l 2(aq)  +  c l 2(g)  \uf0ae  2fec l 3(aq)    which statements about this reaction are correct?    1 fe2+ ions are reduced to fe3+ ions.  2 chlorine acts as a reducing agent.  3 fe2+ ions each lose an electron.  4 c l 2 molecules are reduced to c l \u2013 ions.    a 1 and 2 b 2 and 3 c 2 and 4 d 3 and 4    ",
            "8": "8  \u00a9 ucles 2021 0620/23/o/n/21  17 excess dilute hydrochloric acid is added to equal masses of pow dered calcium carbonate in two  separate experiments.    two different concentrations of hydrochloric acid are used. the  temperature in both experiments  is the same.    the results show the change in mass of the reaction flask measu red over time.    mass of reactionflask time 001.0 mol  / dm3 hc l 2.0 mol  / dm3 hc l     why is the rate of reaction for the 1.0  mol  / dm3 hydrochloric acid slower?     collision energy collision rate  a lower higher  b lower lower  c same as for 2.0  mol  / dm3 h i g h e r   d same as for 2.0  mol  / dm3 l o w e r       18 basic oxides are neutralised by acidic oxides.    which element forms an oxide that neutralises calcium oxide?  a hydrogen  b magnesium  c sodium  d sulfur    ",
            "9": "9     \u00a9 ucles 2021 0620/23/o/n/21 [turn over  19 four solid oxides are added to dilute hydrochloric acid and aqu eous sodium hydroxide.    which row describes an amphoteric oxide?     hydrochloric acid sodium hydroxide   a \u0016 \u0016 key  b \u001a \u0016 \u0016 = reacts  c \u0016 \u001a \u001a = does not react  d \u001a \u001a      20 which row describes an acid and an oxidising agent?     acid oxidising agent  a proton acceptor electron acceptor  b proton acceptor electron donor  c proton donor electron acceptor  d proton donor electron donor     21 a period of the periodic table is shown.    group i ii iii iv v vi vii viii  element r s t v w x y z    the letters are not their chemical symbols.    which statement is correct?  a element r does not conduct electricity.  b elements r and y react together to form an ionic compound.  c element z exists as a diatomic molecule.  d element z reacts with element t.     ",
            "10": "10  \u00a9 ucles 2021 0620/23/o/n/21  22 part of the periodic table is shown.    jk lmn     which pairs of the elements j, k, l, m and n react together to form a product with a 1  : 1 ratio?  a j and l k and m  b j and m k and n  c j and n k and l  d j and n k and m      23 which property is shown by transition metals but not shown by group i metals?  a good electrical conductivity  b good thermal conductivity  c loss of electrons to form positive ions  d variable oxidation states     24 the noble gases are in group viii of the periodic table.    which statement explains why noble gases are unreactive?  a they all have eight electrons in their outer shells.  b they all have full outer shells.  c they are all gases.  d they are all monoatomic.     25 which statement is correct for all metals?  a they conduct electricity when molten.  b they gain electrons when they form ions.  c they have a low density.  d they have a low melting point.    ",
            "11": "11     \u00a9 ucles 2021 0620/23/o/n/21 [turn over  26 chromium is a more reactive metal than iron but less reactive t han zinc.    which statements are correct?    1 chromium does not react with dilute hydrochloric acid.  2 chromium oxide is reduced when it is heated with carbon. 3 chromium reacts with zinc oxide to form zinc. 4 chromium reacts with steam to form hydrogen gas.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     27 aluminium objects do not need protection from corrosion.    iron objects must be protected from corrosion.    which statement explains why aluminium resists corrosion?  a aluminium does not form ions easily.  b aluminium does not react with water or air.  c aluminium has a protective oxide layer.  d aluminium is below iron in the reactivity series.      28 which statement describes how oxides of nitrogen are formed in a car engine?  a nitrogen from the air reacts with oxygen from petrol.  b nitrogen from the air reacts with oxygen from the air.  c nitrogen from petrol reacts with oxygen from petrol.  d nitrogen from petrol reacts with oxygen from the air.      29 ships are made of steel, an alloy of iron.    blocks of magnesium are attached to the underside of ships to p revent rusting.    which statement explains how the magnesium prevents rusting?  a magnesium oxidises instead of iron.  b magnesium stops air and water getting to the iron.  c the magnesium forms an alloy with iron which does not corrode.  d the magnesium reacts with rust as soon as it is formed.    ",
            "12": "12  \u00a9 ucles 2021 0620/23/o/n/21  30 which process is used to produce hydrogen for the haber process ?  a electrolysis of water  b reacting aluminium with sodium hydroxide  c reacting iron with sulfuric acid  d reacting methane with steam      31 one of the steps in manufacturing sulfuric acid in the contact process is shown.    2so 2(g)  +  o 2(g)    2so 3(g)    which catalyst is used to increase the rate of this reaction?  a aluminium oxide  b iron  c phosphoric acid  d vanadium( v) oxide     32 lime (calcium oxide) is used to treat waste water from a facto ry.    which substance is removed by the lime?  a ammonia  b sodium chloride  c sodium hydroxide  d s u l f u r i c  a c i d      33 what is the structure of propanol?    c o h h ch hh o hca c o h hh o hc c o h hh hhh cb c o h h ch hhhhh ccd      ",
            "13": "13     \u00a9 ucles 2021 0620/23/o/n/21 [turn over  34 fuel x produces carbon dioxide and water when it is burned in air. so does fuel y.    what could x and y be?     x  y   a c h 2  b c c 8h18  c ch 4 h 2  d ch 4 c 8h18      35 what is the main constituent of natural gas?  a hydrogen  b carbon monoxide  c methane  d nitrogen     36 which statement describes the members of a homologous series?  a compounds with the same physical properties  b compounds containing the same functional group  c compounds containing the same number and type of bonds  d compounds obtained from the same raw material     37 the structures of two compounds are shown.    o hch hhch ho co ohch hhch hc     which statements about these compounds are correct?    1 they have the same molecular formula.  2 they have similar chemical properties. 3 they are structural isomers.    a 1 only b 1 and 2 c 2 and 3 d 1 and 3    ",
            "14": "14  \u00a9 ucles 2021 0620/23/o/n/21  38 some reactions of substance q are shown.    q padd bromine add hydrogen and a catalystadd steam under pressure and a catalyst 1,2-dibromoethane is madeethanol is made     what is p?  a ethane  b ethanoic acid  c ethene  d poly(ethene)    39 proteins and starch are natural polymers.    which row identifies the method of polymerisation of proteins a nd starch?     proteins starch  a addition addition  b condensation condensation  c addition condensation  d condensation addition     ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambri dge assessment is the brand name  of the university of  cambridge local examinations sy ndicate (ucles), which itself is  a department of the univ ersity of cambridge.    \u00a9 ucles 2021 0620/23/o/n/21  40 the diagram shows the partial structure of terylene .    co c co o o oo    from which pair of compounds is it made?    co co ho oh ho oh+ co co ho oh co co ho oh co co ho ohho oh a co ho oh + co ho oh b + c + d       ",
            "16": "16  \u00a9 ucles 2021 0620/23/o/n/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_w21_qp_31.pdf": {
            "1": "*3901701282* chemistry  0620/31 paper 3 theory (core) october/november 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 11_0620_31/4rp \u00a9 ucles 2021 [turn overthis document has 20 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/31/o/n/21 \u00a9 ucles 2021 1 (a)  a list of formulae is shown. al cl 3 caco3 co co2 cocl 2 cuso4 mgcl 2 n2 nacl nh3 o2 so2   answer the following questions using these formulae.   each formula may be used once, more than once or not at all.   state which formula represents:  (i)  a compound that changes colour from white to blue when water is added   ...   [1]  (ii)  a compound that is used to make cement   ...   [1]  (iii)  an element that forms 78% of clean, dry air   ...   [1]  (iv)  a compound that contains an ion with a single positive charge   ...   [1]  (v)  a compound that dissolves in water to form an alkaline solution.   ...   [1]",
            "3": "3 0620/31/o/n/21 \u00a9 ucles 2021 [turn over  (b)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  ammonia. n h hh  [2]  (c)  state whether magnesium oxide is a basic oxide or an acidic oxide.   give a reason for your answer.      ..   [1]  [total: 8]",
            "4": "4 0620/31/o/n/21 \u00a9 ucles 2021 2  the table shows the masses of some of the ions in 1000 cm3 of rainwater. name of ion formula of ionmass of ion in 1000 cm3 of rainwater / mg nh4+0.08 calcium ca2+0.13 chloride cl \u20131.30 magnesium mg2+0.08 nitrate no3\u20130.70 potassium k+0.08 sodium na+0.80 so42\u20131.60  (a)  answer these questions using only the information in the table.  (i)  state which of the positive ions has the highest concentration.   ...   [1]  (ii)  name the compound containing nh4+ and so42\u2013 ions.   ...   [1]  (iii)  calculate the mass of magnesium ions in 400 cm3 of rainwater.  mass = .. mg  [1]  (b)  describe a test for chloride ions.  test  .  observations  ..  [2]",
            "5": "5 0620/31/o/n/21 \u00a9 ucles 2021 [turn over  (c)  small amounts of carboxylic acids are also present in rainwater.   the structure of tartaric acid is shown. c hh o c c oo oh c h ho oh  (i)  on the structure draw a circle around one alcohol functional group. [1]  (ii)  deduce the formula of tartaric acid to show the number of carbon, hydrogen and oxygen  atoms.   ...   [1]  (d)  tartaric acid can be converted into compound a.   the formula of compound a is c3h4o3.   complete the table to calculate the relative molecular mass of compound a. type of atomnumber of atomsrelative atomic mass carbon 3 12 3 \u00d7 12 = 36 hydrogen 1 oxygen 16  relative molecular mass = ..  [2]  [total: 9]",
            "6": "6 0620/31/o/n/21 \u00a9 ucles 2021 3  the diagram shows a blast furnace used in the extraction of iron. mixture of iron ore, coke and limeston e molten slag molten ironebc d  (a)  air is blown into the furnace.   state which letter on the diagram, b, c, d or e, shows where air is blown into the furnace.   ..   [1]  (b) (i)  complete the chemical equation for the reduction of iron( iii) oxide in the blast furnace.  fe2o3  +  3c  \u2192  ..fe  +  ..co [2]  (ii)  explain how this equation shows that iron( iii) oxide is reduced.   ...   [1]  (c)  calcium carbonate (limestone) is added to the blast furnace.   the calcium carbonate undergoes thermal decomposition.  (i)  complete the word equation for this reaction. calcium carbonate\u2192 +   [2]  (ii)  one of the products of this reaction reacts with impurities in the iron to form slag.   use the information in the diagram to suggest how you know that molten slag is less  dense than molten iron.   ...   [1]",
            "7": "7 0620/31/o/n/21 \u00a9 ucles 2021 [turn over  (d) (i)  use words from the list to complete these sentences about how steel is made from iron. acidic      basic      chlorides      methane      neutral nitrogen      oxides      oxygen      sulfates   a gas is blown through the molten iron. the name of this gas is  .   acidic gases are formed. these acidic gases react with    .  [3]  (ii)  state one use of mild steel.   ...   [1]  (iii)  metals such as chromium are added to iron to make stainless steel.   the symbol for an isotope of chromium is shown. 53cr24   deduce the number of electrons, neutrons and protons in one atom of this isotope of  chromium.   number of electrons     number of neutrons     number of protons  ..  [3]  (e)  chromium conducts electricity and is shiny.   give two other physical properties of chromium that are characteristic of all metals.  1  .  2  .  [2]  [total: 16]",
            "8": "8 0620/31/o/n/21 \u00a9 ucles 2021 4  the table shows some properties of the group i elements. elementmelting point / \u00b0cdensity in g / cm3observations during reaction with water lithium 181slow bubbling no flame sodium 98rapid bubbling no flame potassium 63 0.86rapid bubbling lilac flame rubidium 1.53 caesium 29 1.88 explodes  (a) (i)  complete the table by predicting:  \u25cf the melting point of rubidium  \u25cf the density of lithium. [2]  (ii)  predict the observations when rubidium reacts with water.   .   ...   [1]  (b)  deduce the electronic structure of potassium.   use the periodic table to help you.   ..   [1]  (c)  lithium reacts with water to produce aqueous lithium  hydroxide and a gas which \u2018pops\u2019 with a  lighted splint.  (i)  name the gas which \u2018pops\u2019 with a lighted splint.   ...   [1]  (ii)  choose one ph value from the list that best describes the ph of aqueous lithium hydroxide.   draw a circle around the correct answer.  ph 2                ph 5                ph 7                ph 13  [1]  (iii)  lithium reacts with nitrogen.   complete the chemical equation for this reaction.  ..li  +  n2  \u2192  ..li3n [2]  [total: 8]",
            "9": "9 0620/31/o/n/21 \u00a9 ucles 2021 [turn over question 5 starts on the next page.",
            "10": "10 0620/31/o/n/21 \u00a9 ucles 2021 5  the table shows the structures of some organic compounds. compound structure of compound homologous series g hch hch hco oh carboxylic acid h hch hc hhch j hchh hch h  (a)  complete the table by naming the homologous series.   the first one has been done for you. [2]  (b)  draw the structure of a compound containing two carbon atoms which belongs to the same  homologous series as compound h.   show all of the atoms and all of the bonds.  [1]  (c)  state which compound in the table is an unsaturated hydrocarbon.   explain your answer.      ..   [1]",
            "11": "11 0620/31/o/n/21 \u00a9 ucles 2021 [turn over  (d)  state which compound in the table reacts with aqueous sodium hydroxide.   explain your answer.      ..   [1]  (e)  state the names of the two compounds formed during the complete combustion of compound j.  ... and  ...   [2]  (f)  compound h can be polymerised.  (i)  state the general name given to the small units which join together to form a polymer.   ...   [1]  (ii)  terylene  is also a polymer.   give one use of terylene .   ...   [1]  [total: 9]",
            "12": "12 0620/31/o/n/21 \u00a9 ucles 2021 6  the diagram shows part of the structures of sodium bromide and graphite at room temperature and  pressure. na+br \u2013na+br \u2013 na+br \u2013na+br \u2013br \u2013na+na+br \u2013  (a)  describe the physical properties of these substances in terms of:  \u25cf volatility  sodium bromide  .  graphite  ..  \u25cf solubility in water  sodium bromide  .  graphite  ..  \u25cf electrical conductivity when solid.  sodium bromide  .  graphite  ..  [5]  (b)  when dilute sulfuric acid is electrolysed using inert electrodes, oxygen gas is produced at the  positive electrode.   name the gas produced at the negative electrode.   ..   [1]",
            "13": "13 0620/31/o/n/21 \u00a9 ucles 2021 [turn over  (c)  aqueous sodium bromide reacts with aqueous chlorine.  (i)  complete the word equation for this reaction. sodium bromide+ chlorine \u2192 +  [2]  (ii)  explain in terms of the reactivity of the halogens why aqueous sodium chloride does not  react with aqueous bromine.   .   ...   [1]  [total: 9]",
            "14": "14 0620/31/o/n/21 \u00a9 ucles 2021 7  this question is about nitrogen and compounds of nitrogen.  (a)  when nitrogen is cooled to below \u2013196 \u00b0c it changes state from gas to liquid.  (i)  name the change of state from gas to liquid.   ...   [1]  (ii)  use the kinetic particle theory to describe the differences between nitrogen gas and liquid  nitrogen in terms of:  \u25cf the separation of the particles   .   .   .  \u25cf the motion of the particles.   .   .   .  [4]  (b)  oxides of nitrogen are pollutants in the air.  (i)  state one source of oxides of nitrogen in the air.   ...   [1]  (ii)  oxides of nitrogen contribute to acid rain.   give one adverse effect of acid rain on buildings.   ...   [1]  (c)  nitric acid contains the nitrate ion.  (i)  use words from the list to complete the sentences to describe the test for nitrate ions.  aluminium ammonia chloride copper  hydroxide iron oxygen sulfate   put the sample in a test-tube then add aqueous sodium . .   then add . .    warm gently. a gas is produced. the name of this gas is . .  [3]",
            "15": "15 0620/31/o/n/21 \u00a9 ucles 2021 [turn over  (ii)  nitric acid reacts with calcium carbonate.   complete the word equation for this reaction. nitric acid+calcium carbonate\u2192 + +  [3]  [total: 13]",
            "16": "16 0620/31/o/n/21 \u00a9 ucles 2021 8  the rate of decomposition of aqueous hydrogen peroxide, h2o2, is increased by an enzyme. 2h2o2  \u2192  2h2o  +  o2   the rate of reaction is found by measuring the volume of oxygen gas given off as the reaction  proceeds.   the results are shown on the graph. 60 50 40 30 20 10 0 02 04 06 08 0 time  / svolume of oxygen gas / cm3 100 120 140  (a) (i)  deduce the volume of oxygen gas released when the reaction is complete.  volume = . cm3  [1]  (ii)  deduce the volume of oxygen gas produced 50 seconds from the start of the reaction.  volume = . cm3  [1]  (b)  the experiment was repeated using hydrogen peroxide of a higher concentration.   all other conditions stayed the same.   draw a line on the grid to show how the volume of oxygen changes with time when  hydrogen peroxide of a higher concentration is used. [2]",
            "17": "17 0620/31/o/n/21 \u00a9 ucles 2021 [turn over  (c)  describe the effect each of the following has on the rate of decomposition of hydrogen peroxide.  \u25cf the reaction is carried out at a lower temperature.   all other conditions stay the same.     \u25cf the reaction is carried out without an enzyme.   all other conditions stay the same.     [2]  (d)  some metal oxides catalyse the decomposition of hydrogen peroxide.   the table shows the time taken to produce 20 cm3 of oxygen gas using three different metal  oxide powders as catalysts.   all other conditions stay the same. metal oxidetime taken to produce 20 cm3 of oxygen gas / s iron(iii) oxide 26 lead( iv) oxide 12 manganese( iv) oxide 15  (i)  put the three oxides in order of their ability to catalyse the reaction.   put the best catalyst first. best catalyst worst catalyst  [1]  (ii)  the experiments with the metal oxide catalysts used powdered oxide.   describe the effect on the rate of decomposition of hydrogen peroxide when large pieces  of catalyst are used instead of powdered catalyst.   all other conditions stay the same.   ...   [1]  [total: 8]",
            "18": "18 0620/31/o/n/21 \u00a9 ucles 2021blank page",
            "19": "19 0620/31/o/n/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/31/o/n/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w21_qp_32.pdf": {
            "1": "*8718554281* chemistry  0620/32 paper 3 theory (core) october/november 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 11_0620_32/3rp \u00a9 ucles 2021 [turn overthis document has 20 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/32/o/n/21 \u00a9 ucles 2021 1 (a)  a list of formulae is shown. caco3 cao cl 2 ch4 c2h5oh c2h6 cuso4 h2 h2o mgo nacl so2   answer the following questions using these formulae.   each formula may be used once, more than once or not at all.   state which formula represents:  (i)  a compound that is the main constituent of natural gas   ...   [1]  (ii)  an element that is used in water treatment   ...   [1]  (iii)  an element that bleaches damp litmus paper   ...   [1]  (iv)  a compound that contains an ion with a single negative charge   ...   [1]  (v)  a hydrocarbon that is formed by the decomposition of vegetation.   ...   [1]",
            "3": "3 0620/32/o/n/21 \u00a9 ucles 2021 [turn over  (b)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of water. hh o  [2]  (c)  state whether calcium oxide is a basic oxide or an acidic oxide.   give a reason for your answer.      ..   [1]  [total: 8]",
            "4": "4 0620/32/o/n/21 \u00a9 ucles 2021 2  the table shows the masses of some of the ions in 1000 cm3 of water taken from a lake. name of ion formula of ionmass of ion in 1000 cm3 of lake water / mg calcium ca2+0.41 chloride cl \u20134.40 magnesium mg2+0.39 no3\u20130.03 potassium k+0.30 silicate sio32\u20130.02 na+2.90 sulfate so42\u20132.80  (a)  answer these questions using only the information in the table.  (i)  state which of the negative ions has the lowest concentration.   ...   [1]  (ii)  name the compound containing na+ and no3\u2013 ions.   ...   [1]  (iii)  calculate the mass of chloride ions in 250 cm3 of lake water.  mass = .. mg  [1]  (b)  describe a test for sulfate ions.  test  ..  observations  ...  [2]",
            "5": "5 0620/32/o/n/21 \u00a9 ucles 2021 [turn over  (c)  citric acid is also present in the lake water.   the structure of citric acid is shown. ooh occcccc h hooo o hhhh h  (i)  deduce the number of carboxylic acid groups in one molecule of citric acid.   ...   [1]  (ii)  the formula of citric acid is c6h8o7.   complete the table to calculate the relative molecular mass of citric acid. type of atomnumber of atomsrelative atomic mass carbon 6 12 6 \u00d7 12 = 72 hydrogen 1 oxygen 16  relative molecular mass = ..  [2]  [total: 8]",
            "6": "6 0620/32/o/n/21 \u00a9 ucles 2021 3  iron is extracted from iron ore in a blast furnace.  (a)  name an ore of iron.   ..   [1]  (b) (i)  complete the chemical equation for the reduction of iron( iii) oxide in the blast furnace.  fe2o3  +  .co  \u2192  .fe  +  3co2 [2]  (ii)  state the meaning of the term reduction .   ...   [1]  (c)  calcium carbonate (limestone) is added to the blast furnace.   the calcium carbonate undergoes thermal decomposition.   state the meaning of the term thermal decomposition .      ..   [2]  (d)  iron can be made into stainless steel.  (i)  give one use of stainless steel.   ...   [1]  (ii)  describe one advantage of stainless steel compared with pure iron.   .   ...   [1]  (e)  the symbol for an isotope of iron is shown. 57fe26   deduce the number of electrons, neutrons and protons in one atom of this isotope of iron.  number of electrons  ...  number of neutrons  ...  number of protons  .  [3]",
            "7": "7 0620/32/o/n/21 \u00a9 ucles 2021 [turn over  (f)  iron is a good conductor of heat and electricity.   give two other physical properties of iron that are characteristic of all metals.  1  .  2  .  [2]  (g)  iron rusts.   name the two substances needed for iron to rust.  1  .  2  .  [2]  [total: 15]",
            "8": "8 0620/32/o/n/21 \u00a9 ucles 2021 4  the table shows some properties of the group i elements. elementmelting point / \u00b0cdensity in g / cm3observations during reaction with water lithium 181 0.53 sodium 98rapid bubbling no flame potassium 0.86rapid bubbling lilac flame rubidium 39 1.53very rapid bubbling red flame caesium 29 1.88 explodes francium 27  (a) (i)  complete the table by predicting:  \u25cf the melting point of potassium  \u25cf the density of francium. [2]  (ii)  describe the observations when lithium reacts with water.   .   ...   [1]  (b) (i)  deduce the electronic structure of sodium.   use the periodic table to help you.   ...   [1]  (ii)  explain why a potassium ion has a single positive charge.   .   ...   [1]",
            "9": "9 0620/32/o/n/21 \u00a9 ucles 2021 [turn over  (c)  sodium reacts with water to produce aqueous sodium hydroxide and a gas which \u2018pops\u2019 with  a lighted splint.  (i)  complete the chemical equation for this reaction.  2na  +  2h2o  \u2192  .naoh  +  .. [2]  (ii)  choose one value from the list that best describes the ph of aqueous sodium hydroxide.   draw a circle around the correct answer.  ph 1                ph 4                ph 7                ph 14  [1]  [total: 8]",
            "10": "10 0620/32/o/n/21 \u00a9 ucles 2021 5  the table shows the structures of some organic compounds. compound structure of compound homologous series g hchh hcc hh h halkane h hch hch hch hoh j hch hc hhch  (a)  complete the table by naming the homologous series.   the first one has been done for you. [2]  (b)  draw the structure of a compound containing two carbon atoms which belongs to the same  homologous series as compound h.   show all of the atoms and all of the bonds.  [1]  (c)  describe the colour change when an excess of compound j is added to aqueous bromine.  from  to     [2]",
            "11": "11 0620/32/o/n/21 \u00a9 ucles 2021 [turn over  (d) (i)  compound  j can be obtained by cracking petroleum fractions.   state the conditions needed for cracking.   .   ...   [2]  (ii)  complete this sentence about cracking using a word from the list. bitumen          hydrogen          oxygen          petroleum   the chemicals manufactured by cracking include alkanes, alkenes and .. .  [1]  (e)  compound g is propane.   complete the word equation for the complete combustion of propane. propane + oxygen \u2192 +  [2]  (f)  compound j can form polymers.  (i)  state the meaning of the term polymer .   .   ...   [2]  (ii)  nylon is also a polymer.   give one use of nylon.   ...   [1]  (iii)  describe one pollution problem caused by non-biodegradable plastics.   .   ...   [1]  [total: 14]",
            "12": "12 0620/32/o/n/21 \u00a9 ucles 2021 6  the diagrams show part of the structures of potassium iodide and bromine at room temperature  and pressure. k+i\u2013k+i\u2013 k+i\u2013k+i\u2013i\u2013k+k+i\u2013 brbrbr brbrbrbrbrbrbr brbrbrbr brbr  (a)  describe the physical properties of these substances in terms of:  \u25cf volatility  potassium iodide    bromine  ..  \u25cf solubility in water  potassium iodide    bromine  ..  \u25cf electrical conductivity when molten (liquid).  potassium iodide    bromine  ..  [5]  (b)  molten potassium iodide is electrolysed using carbon (graphite) electrodes.  (i)  name the substance produced at the positive electrode.   ...   [1]  (ii)  aqueous potassium iodide reacts with aqueous bromine.   complete the word equation for this reaction. potassium iodide+ bromine \u2192 +  [2]",
            "13": "13 0620/32/o/n/21 \u00a9 ucles 2021 [turn over  (iii)  explain in terms of the reactivity of the halogens why aqueous potassium chloride does  not react with aqueous bromine.   .   ...   [1]  (c)  name the change of state when liquid bromine changes to solid bromine.   ..   [1]  [total: 10]",
            "14": "14 0620/32/o/n/21 \u00a9 ucles 2021 7  this question is about sulfur and compounds of sulfur.  (a)  use the kinetic particle theory to describe the differences between sulfur gas and solid sulfur  in terms of:  \u25cf the arrangement of the particles           \u25cf the separation of the particles.           [4]  (b)  give the major use of sulfur in industry.   ..   [1]  (c)  sulfur dioxide is a pollutant in the air that contributes to acid rain.  (i)  state one adverse effect of sulfur dioxide on health.   ...   [1]  (ii)  name one other oxide that contributes to acid rain.   ...   [1]  (iii)  sulfur dioxide reacts with water to produce sulfurous acid.   the reaction is reversible.   draw the symbol for a reversible reaction in the box.  so2  +  h2o    h2so3 [1]  (d)  the equation for the reaction of sodium sulfite with zinc is shown. na2so3  +  3zn  \u2192  na2s  +  3zno   explain how this equation shows that zinc is oxidised.      ..   [1]  [total: 9]",
            "15": "15 0620/32/o/n/21 \u00a9 ucles 2021 [turn over 8  a student investigated the reaction of small pieces of calcium carbonate with dilute hydrochloric acid.  the hydrochloric acid was in excess. caco3  +  2hcl  \u2192  cacl 2  +  co2  +  h2o   the rate of reaction is found by measuring the decrease in the mass of the reaction mixture with  time.   the results are shown on the graph. 200 199 198 02 04 06 08 0 time  / smass of reaction mixture  / g 100 120 140  (a)  deduce the time taken from the beginning of the experiment for the mass of the reaction  mixture to decrease by 1.0 g.  time = .. s  [1]  (b)  the experiment was repeated using dilute hydrochloric acid of a higher concentration.   all other conditions stayed the same.   draw a line on the grid to show how the mass of the reaction mixture changes with time using  acid of a higher concentration. [2]",
            "16": "16 0620/32/o/n/21 \u00a9 ucles 2021  (c)  describe the effect each of the following has on the rate of reaction of calcium carbonate with  hydrochloric acid.   all other conditions stay the same.  \u25cf the reaction is carried out at a higher temperature.     \u25cf the reaction is carried out using large pieces of calcium carbonate instead of small pieces  of calcium carbonate.     [2]  (d)  when 0.44 g of calcium carbonate is used, 100 cm3 of carbon dioxide gas is formed.   calculate the mass of calcium carbonate needed to produce 25 cm3 of carbon dioxide gas.  mass of calcium carbonate = .. g  [1]  (e)  the table compares the reaction of four metals with dilute hydrochloric acid. metal observations iron bubbles produced slowly magnesium bubbles produced very rapidly nickel bubbles produced very slowly silver no bubbles produced   put the four metals in order of their reactivity.   put the least reactive metal first. least reactive most reactive  [2]  [total: 8]",
            "17": "17 0620/32/o/n/21 \u00a9 ucles 2021blank page",
            "18": "18 0620/32/o/n/21 \u00a9 ucles 2021blank page",
            "19": "19 0620/32/o/n/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/32/o/n/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w21_qp_33.pdf": {
            "1": "*0344015682* chemistry  0620/33 paper 3 theory (core) october/november 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 11_0620_33/3rp \u00a9 ucles 2021 [turn overthis document has 20 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/33/o/n/21 \u00a9 ucles 2021 1 (a)  a list of formulae is shown. br2 co co2 ch4 c2h6 hcl kbr licl mgcl 2 o2 so2   answer the following questions using these formulae.   each formula may be used once, more than once or not at all.   state which formula represents:  (i)\t\ta\tcompound\tthat\tgives\ta\tred\tcolour\tin\ta \tflame\ttest   ...   [1]  (ii)  a compound containing an ion with a 2+ charge   ...   [1]  (iii)  a compound that is a product of respiration   ...   [1]  (iv)  a compound used as a food preservative   ...   [1]  (v)  an element that is used in the production of steel.   ...   [1]",
            "3": "3 0620/33/o/n/21 \u00a9 ucles 2021 [turn over  (b)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  hydrogen chloride. show outer shell electrons only. cl h  [2]  (c)  state whether carbon dioxide is a basic oxide or an acidic oxide.   give a reason for your answer.      ..   [1]  [total: 8]",
            "4": "4 0620/33/o/n/21 \u00a9 ucles 2021 2  the table shows the masses of some of the ions in 1000 cm3 of water from a river. name of ion formula of ionmass of ion in 1000 cm3 of river water / mg ammonium nh4+1.0 ca2+16.5 chloride cl \u20137.0 iron(iii) fe3+0.5 magnesium mg2+4.0 no3\u20130.5 potassium k+3.5 silicate sio32\u20137.5 sodium na+6.0 sulfate so42\u201311.0  (a)  answer these questions using only the information in the table.  (i)  state which positive ion has the lowest concentration.   ...   [1]  (ii)  name the compound containing ca2+ and no3\u2013 ions.   ...   [1]  (iii)  calculate the mass of sulfate ions in 500  cm3 of river water.  mass = .. mg  [1]  (b)  describe a test for iron( iii) ions.  test  .  observations  ..  [2]",
            "5": "5 0620/33/o/n/21 \u00a9 ucles 2021 [turn over  (c)  compound a is found in river water.   the structure of compound a is shown. h oo o hhh c hch hnc  (i)  on the structure draw a circle around the alcohol functional group. [1]  (ii)  deduce the formula of compound a to show the number of carbon, hydrogen, oxygen and  nitrogen atoms.   ...   [1]  (iii)  another compound found in river water has the formula c4h8o2.   complete the table to calculate the relative molecular mass of this compound. type of atomnumber of atomsrelative atomic mass carbon 4 12 4 \u00d7 12 = 48 hydrogen 1 oxygen 16  relative molecular mass = ..  [2]  [total: 9]",
            "6": "6 0620/33/o/n/21 \u00a9 ucles 2021 3  iron is extracted in a blast furnace using a mixture of iron ore, coke (carbon), air and calcium carbonate  (limestone).  (a)  give two reasons why air is blown into the blast furnace.  1  .  2  .  [2]  (b)  magnetite is an ore of iron which contains a compound of iron with the formula fe3o4.  (i)  give the name of another ore of iron.   ...   [1]  (ii)  in the blast furnace fe3o4 is reduced to fe.   complete the chemical equation for the reduction of fe3o4.  fe3o4  +  4co  \u2192  .fe  +  .co2 [2]  (iii)  explain how this equation shows that fe3o4 is reduced.   ...   [1]  (c)  calcium carbonate (limestone) is added to the blast furnace.   the calcium carbonate undergoes thermal decomposition.   give the meaning of the term thermal decomposition .   ..   [2]  (d)  iron can form alloys such as vanadium steel.  (i)  state the meaning of the term alloy .   .   ...   [1]",
            "7": "7 0620/33/o/n/21 \u00a9 ucles 2021 [turn over  (ii)  choose from the diagrams, b, c, d or e, the structure which best represents an alloy. b c d e  structure ..  [1]  (iii)  the symbol for an isotope of vanadium is shown. 51v23   deduce the number of electrons, neutrons and protons in one atom of this isotope of  vanadium.  number of electrons    number of neutrons    number of protons  ..  [3]  (iv)  vanadium is malleable and conducts electricity.   give two other physical properties of vanadium that are characteristic of all metals.  1  ..  2  ..  [2]  [total: 15]",
            "8": "8 0620/33/o/n/21 \u00a9 ucles 2021 4  the table shows some properties of four halogens in group vii. halogenmelting point / \u00b0cboiling point / \u00b0cdensity of liquid at boiling point in g / cm3 chlorine \u2013101 \u201335 1.56 bromine \u20137 59 iodine 114 4.93 astatine 302 337 6.35  (a) (i)  complete the table by predicting:  \u25cf the boiling point of iodine  \u25cf the density of bromine. [2]  (ii)  describe the trend in the melting points of the halogens down group vii.   ...   [1]  (b) (i)  deduce the electronic structure of chlorine.   use the periodic table to help you.   ...   [1]  (ii)  explain why a bromide ion has a single negative charge.   .   ...   [1]  (c)  scientists have predicted that sodium astatide reacts with chlorine.   complete the word equation for this reaction. sodium astatide+ chlorine \u2192 +  [2]",
            "9": "9 0620/33/o/n/21 \u00a9 ucles 2021 [turn over  (d)  hydrogen chloride is produced when chlorine reacts with ammonia.   an aqueous solution of hydrogen chloride is acidic.   describe how you could determine the ph of an acidic solution without using a ph meter.         ..   [2]  [total: 9]",
            "10": "10 0620/33/o/n/21 \u00a9 ucles 2021 5  the table shows the structures of some organic compounds. compound structure of compound homologous series f hch hch hco oh carboxylic acid gh cc hh h h hchh hcc hh h h  (a)  complete the table by naming the homologous series. \t \tthe\tfirst\tone\thas\tbeen\tdone\tfor\tyou.\t [2]  (b)  draw the structure of a compound containing two carbon atoms which belongs to the same  homologous series as compound f.   show all of the atoms and all of the bonds.  [1]",
            "11": "11 0620/33/o/n/21 \u00a9 ucles 2021 [turn over  (c)  compound g reacts with bromine.   choose from the structures, p, q, r or s, the structure of the product formed. hch hcp br hbr c hcq brbr hch hcr br brhhc hcs brbr h   ..   [1]  (d) (i)  compound  g can be obtained by cracking petroleum fractions.   describe what is meant by the term cracking.   .   ...   [2]  (ii)  name the product of the reaction when compound g reacts with steam.   ...   [1]  (iii)  many molecules of compound g can join together to form a compound with a very long  chain.   choose from the list the general name given to a compound that is formed by the addition  of many small units.   draw a circle around the correct answer.  isomer          monomer          naphtha          polymer  [1]  (e)  state the names of the two compounds formed during the complete combustion of compound h.   and  ..   [2]  [total: 10]",
            "12": "12 0620/33/o/n/21 \u00a9 ucles 2021 6  the diagram shows part of the structures of sodium chloride and pentane at room temperature and  pressure. represents pentane , ch3ch2ch2ch2ch3na+cl \u2013na+cl \u2013 na+cl \u2013na+cl \u2013cl \u2013na+na+cl \u2013  (a)\t\tdescribe\tthe\tdifferences\tin\tthe\tphysical\tproperties\tof\tthese\tsubstances\tin\tterms\tof:  \u25cf volatility  sodium chloride  .  pentane  ..  \u25cf solubility in water  sodium chloride  .  pentane  ..  \u25cf electrical conductivity when molten (liquid).  sodium chloride  .  pentane  ..  [5]  (b)  concentrated aqueous sodium chloride is electrolysed using carbon (graphite) electrodes.   name the gas produced at the positive electrode.   ..   [1]  (c)  pentane is a fuel. under some conditions pentane forms carbon monoxide.  (i)  state the condition under which pentane forms carbon monoxide.   ...   [1]  (ii)  state one\tadverse\teffect\tof\tcarbon\tmonoxide\ton\thealth.   ...   [1]  [total: 8]",
            "13": "13 0620/33/o/n/21 \u00a9 ucles 2021 [turn over 7  this question is about aluminium and the extraction of metals.  (a)  when aluminium is heated above 660 \u00b0c it changes from solid to liquid.  (i)  name the change of state from solid to liquid.   ...   [1]  (ii)\t\tuse\tthe\tkinetic\tparticle\ttheory\tto\tdescribe\t the\tdifferences\t between\t solid\taluminium\t and\t liquid aluminium in terms of:  \u25cf the separation of the particles   .   .   .  \u25cf the motion of the particles.   .   .   .  [4]  (b)  aluminium is extracted from aluminium ore by electrolysis.   explain why aluminium is extracted by electrolysis and not by reduction with carbon.   ..   [1]  (c)  give two reasons why aluminium is used in the manufacture of aircraft.  1  .  2  .  [2]  (d)  give one advantage of recycling aluminium.      ..   [1]",
            "14": "14 0620/33/o/n/21 \u00a9 ucles 2021  (e)  the table compares the ease of reduction of four metal oxides when heated with carbon. metal oxide ease of reduction aluminium oxide not reduced at 2080 \u00b0c nickel( ii) oxide reduced at 540 \u00b0c titanium( iv) oxide reduced at 1600 \u00b0c zinc oxide reduced at 850 \u00b0c   put the four metals in order of their reactivity. \t \tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive  [2]  (f)  methane is used as a fuel in the extraction of some metals.  (i)  state the main source of methane.   ...   [1]  (ii)  state one\tadverse\teffect\tof\tmethane\ton \tthe\tenvironment.   ...   [1]  [total: 13]",
            "15": "15 0620/33/o/n/21 \u00a9 ucles 2021 [turn over 8  a student investigated the reaction of small pieces of zinc with dilute hydrochloric acid. the  hydrochloric acid was in excess. zn  +  2hcl  \u2192  zncl 2  +  h2   the rate of reaction is found by measuring the increase in volume of hydrogen gas with time.   the results are shown on the graph. 02 04 06 08 0 time  / svolume of hydrogen gas / cm3 100 120 14060 50 40 30 20 10 0  (a)  deduce the time taken from the beginning of the experiment to collect 30 cm3 of hydrogen gas.  time = .. s  [1]  (b)  the experiment was repeated using dilute hydrochloric acid of a higher concentration.   all other conditions stayed the same.   draw a line on the grid  to show how the volume of hydrogen gas changes with time. [2]",
            "16": "16 0620/33/o/n/21 \u00a9 ucles 2021  (c)\t\tdescribe\t the\teffect\teach\tof\tthe\tfollowing\t has\ton\tthe\trate\tof\treaction\t of\tzinc\twith\tdilute\t hydrochloric acid.    all other conditions stay the same.  \u25cf the reaction is carried out at a lower temperature.     \u25cf the reaction is carried out using zinc powder instead of small pieces of zinc.     [2]  (d)  when 0.065 g of zinc is used, 24 cm3 of hydrogen gas is formed.   calculate the mass of zinc needed to produce 96 cm3 of hydrogen gas.  mass of zinc = .. g  [1]  (e)  aqueous ammonia is added to aqueous zinc chloride.   describe the observations when a few drops of aqueous ammonia are added and when excess  aqueous ammonia is added.   a few drops of aqueous ammonia  .   excess aqueous ammonia  .  [2]  [total: 8]",
            "17": "17 0620/33/o/n/21 \u00a9 ucles 2021blank page",
            "18": "18 0620/33/o/n/21 \u00a9 ucles 2021blank page",
            "19": "19 0620/33/o/n/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.",
            "20": "20 0620/33/o/n/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w21_qp_41.pdf": {
            "1": "*4684088012* chemistry  0620/41 paper 4 theory (extended) october/november 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 11_0620_41/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages.cambridge igcse\u2122",
            "2": "2 0620/41/o/n/21 \u00a9 ucles 2021 1  some elements are shown in the order they appear in the reactivity series. the most reactive  element is at the top. sodium calcium magnesium aluminium zinc iron hydrogen copper  (a)  answer the questions using the list of elements. each element may be used once, more than  once or not at all.   identify:  (i)  a non-metal   ...   [1]  (ii)  a metal which is stored under oil   ...   [1]  (iii)  the main component of steel   ...   [1]  (iv)  a metal with three electrons in the outer shell of its atoms   ...   [1]  (v)  a metal found in brass   ...   [1]  (vi)  a metal that forms chlorides of the type xcl 2 and xcl 3.   ...   [1]  (b)  name the main ores of:  (i)  zinc  ...   [1]  (ii)  aluminium.     [1]  (c)  in an experiment, a sample of aluminium appeared less reactive than expected.   explain why.      ..   [1]",
            "3": "3 0620/41/o/n/21 \u00a9 ucles 2021 [turn over  (d)  name two metals from the list which are extracted by reduction of their ores using carbon.  1  .  2  .  [2]  (e)  when zinc granules are added to aqueous copper( ii) sulfate, a reaction occurs. during the  reaction, a red-pink solid is formed and the solution becomes colourless.  (i)  name the red-pink solid.   ...   [1]  (ii)  name the colourless solution.   ...   [1]  (iii)  explain, in terms of particles, why the rate of this reaction increases when the temperature  is increased.   .   .   .   .   .   ...   [3]  (iv)  suggest two other ways of increasing the rate of this reaction.  1  ..  2  ..  [2]  [total: 18]",
            "4": "4 0620/41/o/n/21 \u00a9 ucles 2021 2  this question is about copper and its compounds.  (a)\t\tcopper\thas\ttwo\tdifferent\tnaturally\toccurring\tatoms, \t63cu and 65cu.  (i)\t\tstate\tthe\tterm\tused\tfor\tatoms\tof\tthe\tsame\telement\twith\tdifferent\tnucleon\tnumbers.   ...   [1]  (ii)  the atomic number of copper is 29.   complete the table to show the number of protons, neutrons and electrons in the particles  of copper shown. 63cu65cu2+ protons neutrons electrons  [3]  (iii)  relative atomic mass is the average mass of naturally occurring atoms of an element.   the percentage of the naturally occurring atoms in a sample of copper is shown. 63cu65cu 70% 30%   deduce the relative atomic mass of copper in this sample.   give your answer to one decimal place.  relative atomic mass = ..  [2]",
            "5": "5 0620/41/o/n/21 \u00a9 ucles 2021 [turn over  (b)  anhydrous copper( ii) sulfate is used to test for the presence of water. when this test is positive,  hydrated copper( ii) sulfate is formed.  (i)  state the colour change seen during this test.  from . to     [2]  (ii)  complete the chemical equation to show the reaction that takes place.  cuso4  +      cuso4\u20225h2o [1]  (iii)  state how hydrated copper( ii) sulfate can be turned back into anhydrous copper( ii) sulfate.   ...   [1]  (iv)  describe a test for pure water.   .   ...   [2]  (c)  aqueous copper( ii) sulfate contains cu2+(aq) ions.  (i)  describe what is seen when aqueous copper( ii) sulfate is added to aqueous  sodium hydroxide, naoh(aq).   ...   [1]  (ii)  write the ionic equation for the reaction between aqueous copper( ii) sulfate and aqueous  sodium hydroxide.   include state symbols.   ...   [3]",
            "6": "6 0620/41/o/n/21 \u00a9 ucles 2021  (d)  when solid copper( ii) nitrate is heated copper( ii) oxide, nitrogen dioxide and oxygen are  formed. 2cu(no3)2  \u2192  2cuo  +  4no2  +  o2   calculate the volume of nitrogen dioxide formed at room temperature and pressure when 4.7 g  of cu(no3)2 is heated.   use the following steps:  \u25cf calculate the mass of one mole of cu(no3)2  .. g  \u25cf calculate the number of moles of cu(no3)2 used  .. moles  \u25cf determine the number of moles of nitrogen dioxide formed  .. moles  \u25cf calculate the volume of nitrogen dioxide formed at room temperature and pressure.  .. dm3  [4]  (e)  write the chemical equation to show the action of heat on sodium nitrate, nano3.   ..   [2]  [total: 22]",
            "7": "7 0620/41/o/n/21 \u00a9 ucles 2021 [turn over 3  this question is about electrolysis.   concentrated hydrochloric acid is electrolysed using the apparatus shown. concentrate d hydrochloric acidcarbon electrode swire + \u2013  (a)  chloride ions are discharged at the anode.  (i)  complete the ionic half-equation for this reaction.  ..c l \u2013(aq)  \u2192  ..(g)  +  ..e\u2013 [2]  (ii)  state whether oxidation or reduction takes place. explain your answer.   .   ...   [1]  (b)  describe what is seen at the cathode.   ..   [1]  (c)  write the ionic half-equation for the reaction at the cathode.   ..   [2]  (d)  the ph of the electrolyte is measured throughout the experiment.  (i)  suggest the ph of the electrolyte at the beginning of the experiment.   ...   [1]  (ii)  state how the ph changes, if at all, during the experiment.   explain your answer.   .   ...   [2]",
            "8": "8 0620/41/o/n/21 \u00a9 ucles 2021  (e)  the electrolysis is repeated using molten lead( ii) bromide.   describe what is seen at the: \t \u25cf\t \tcathode\t ... \t \u25cf\t \tanode.\t .  [2]  (f)  state two properties of graphite (carbon) which make it suitable for use as an electrode.  1  .  2  .  [2]  [total: 13]",
            "9": "9 0620/41/o/n/21 \u00a9 ucles 2021 [turn over 4  chalcopyrite, fecus2, is used in the manufacture of sulfuric acid in the contact process.  (a)\t\tin\tthe\tfirst\tstage\tof\tthe\tprocess,\t chalcopyrite\t reacts\twith\toxygen\t in\tthe\tair\tto\tproduce\t sulfur dioxide, so2, iron( iii) oxide and copper( ii) oxide.   complete the chemical equation for the reaction of fecus2 with oxygen.  4fecus2  +  13o2  \u2192  .  +  .  +  . [2]  (b)  sulfur dioxide is then converted to sulfur trioxide. 2so2  +  o2    2so3   the reaction is exothermic. it is also an equilibrium.  (i)  state two features of an equilibrium.  1  ..  2  ..  [2]  (ii)  state the temperature and pressure used in this reaction.   include units. \t \u25cf\t\ttemperature\t . \t \u25cf\t\tpressure\t ...  [2]  (iii)  name the catalyst used.   ...   [1]  (iv)  explain why a catalyst is used.   ...   [1]  (v)  describe and explain, in terms of equilibrium, what happens when the temperature is  increased.   .   ...   [2]  (c)  concentrated sulfuric acid is a dehydrating agent.   when glucose is dehydrated, carbon and one other product are formed.   complete the equation to show the dehydration of glucose, c6h12o6.  c6h12o6  \u2192  ...c  +  . [2]  [total: 12]",
            "10": "10 0620/41/o/n/21 \u00a9 ucles 2021 5  alkenes and carboxylic acids are both families of similar compounds with similar chemical properties.   alkenes\tand\tcarboxylic\tacids\thave\tdifferent\treactions.  (a)  state the term used for a \u2018family\u2019 of similar compounds.   ..   [1]  (b)  state the general formula of alkenes.   ..   [1]  (c)  the structure of but-2-ene is shown. hch hc hc ch hhh  (i)  but-2-ene reacts with aqueous bromine in an addition reaction.   describe the colour change seen when but-2-ene is added to aqueous bromine.  from . to     [1]  (ii)  state what is meant by the term addition reaction.   ...   [1]  (iii)  write the chemical equation for the reaction between but-2-ene and bromine.   ...   [2]  (iv)  but-2-ene forms a polymer.   suggest the name of the polymer formed from but-2-ene.   ...   [1]  (v)  name and draw a structural isomer of but-2-ene.   show all of the atoms and all of the bonds.   name  ...   structure   [2]",
            "11": "11 0620/41/o/n/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge.  (d)  butanoic acid, ch3ch2ch2cooh, is a carboxylic acid.  (i)  deduce the empirical formula of butanoic acid.   ...   [1]  (ii)  complete the chemical equation for the reaction of butanoic acid and sodium carbonate,  na2co3.  2ch3ch2ch2cooh  +  na2co3  \u2192    +  ...  + ... [2]  (iii)  butanoic acid reacts with methanol to form an organic compound and water.  \u25cf name the organic compound formed.   ...   [1]  \u25cf draw the structure of the organic compound formed.   show all of the atoms and all of the bonds.  [2]  [total: 15]",
            "12": "12 0620/41/o/n/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w21_qp_42.pdf": {
            "1": "*8417627571* chemistry  0620/42 paper 4 theory (extended) october/november 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 11_0620_42/3rp \u00a9 ucles 2021 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/42/o/n/21 \u00a9 ucles 2021 1  this question is about states of matter.  (a)  complete the table, using ticks (\uf033  ) and crosses (\uf037   ), to describe the properties of gases, liquids  and solids. state of matterparticles are touchingparticles have random movementparticles are regularly arranged gas liquid solid  [3]  (b)  substances can change state.  (i)  boiling and evaporation are two ways in which a liquid changes into a gas.   describe two differences between boiling and evaporation.  1  ..  2  ..   [2]  (ii)  name the change of state when:  \u25cf a gas becomes a liquid    \u25cf a solid becomes a gas.    [2]",
            "3": "3 0620/42/o/n/21 \u00a9 ucles 2021 [turn over  (c)  a substance boils at temperature x and melts at temperature y.   complete the graph to show the change in temperature over time as the substance cools from  temperature a to temperature b. a by timex temperature  [2]  (d)  a solution is a mixture of a solute and a solvent.  (i)  name the process when a solid substance mixes with a solvent to form a solution.   ...   [1]  (ii)  name the type of reaction when two solutions react to form an insoluble substance.   ...   [1]  [total: 11]",
            "4": "4 0620/42/o/n/21 \u00a9 ucles 2021 2  acids are important laboratory chemicals.  (a)  some acids completely dissociate in water to form ions.  (i)  state the term applied to acids that completely dissociate in water.   ...   [1]  (ii)  complete the equation to show the complete dissociation of sulfuric acid in water.  h2so4  \u2192  . [2]  (iii)  state the colour of methyl orange in sulfuric acid.   ...   [1]  (b)  the equation for the reaction between powdered zinc carbonate and dilute nitric acid is shown. znco3...  +  2hno3...  \u2192  zn(no3)2...  +  h2o...  +  co2...  (i)  complete the equation by adding state symbols. [2]  (ii)  a student found that 2.5 g of zinc carbonate required 20 cm3 of dilute nitric acid to react  completely.   calculate the concentration of dilute nitric acid using the following steps:  \u25cf calculate the mass of 1 mole of znco3  .. g  \u25cf calculate the number of moles of znco3 reacting  .. moles  \u25cf determine the number of moles of hno3 reacting  .. moles  \u25cf calculate the concentration of hno3.  .. mol / dm3  [4]  [total: 10]",
            "5": "5 0620/42/o/n/21 \u00a9 ucles 2021 [turn over 3  atoms contain protons, neutrons and electrons.  (a)  complete the table to show the relative mass and the relative charge of a proton, a neutron  and an electron. relative mass relative charge proton neutron electron1 1840  [3]  (b)  the table shows the number of protons, neutrons and electrons in some atoms and ions.   complete the table. atom or ionnumber of protonsnumber of neutronsnumber of electrons 32s16 39k+ 19 35 44 36  [5]  [total: 8]",
            "6": "6 0620/42/o/n/21 \u00a9 ucles 2021 4  chlorine reacts with carbon monoxide to produce phosgene gas, coc l 2(g). a catalyst is used. cl 2(g)  +  co(g)    cocl 2(g)   the reaction is exothermic.  (a)  explain why the reaction is exothermic in terms of the energy changes of bond breaking and  bond making.         ..   [3]  (b) (i)  complete the energy level diagram for this reaction.   on your diagram show:  \u25cf the product of the reaction  \u25cf an arrow representing the energy change, labelled \u2206h  \u25cf an arrow representing the activation energy, labelled a. energy progress of reactioncl 2(g)  +  co(g)  [3]  (ii)  state why a catalyst is used.   ...   [1]",
            "7": "7 0620/42/o/n/21 \u00a9 ucles 2021 [turn over  (c)  describe and explain the effect, if any, on the position of equilibrium when:  (i)  the pressure is increased   .   ...   [2]  (ii)  the temperature is increased.   .   ...   [2]  (d)  the reaction between chlorine and carbon monoxide can be represented as shown. cl cl cl+    coco cl   when one mole of chlorine reacts with one mole of carbon monoxide, 230 kj of energy is  released.   some bond energies are shown in the table. bond bond energy in kj / mol cl \u2013cl 240 c=o 745 c\u2013cl 400   use the information to calculate the energy of the bond between the c and the o in  carbon monoxide, co.  bond energy in carbon monoxide, co = .. kj / mol  [3]",
            "8": "8 0620/42/o/n/21 \u00a9 ucles 2021  (e)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of cocl 2. cl clco   show outer electrons only. c cl clo  [3]  [total: 17]",
            "9": "9 0620/42/o/n/21 \u00a9 ucles 2021 [turn over 5  iron is a transition element. potassium is a group  i element.  (a)  iron and potassium have the same type of bonding.   name and describe the type of bonding in these two elements.  name  ..  description  .           [4]  (b)  transition elements and group i elements have some similar physical properties.   they can both:  \u25cf be hammered into a shape  \u25cf conduct electricity  \u25cf be stretched into wires.  (i)  name the term used to describe the ability of elements to be hammered into a shape.   ...   [1]  (ii)  describe what happens to the particles in iron when it is hammered into a shape.   .   ...   [1]  (iii)  suggest why copper, rather than other transition elements, is used for wires which conduct  electricity.   ...   [1]  (c)  transition elements are harder and stronger than group i elements.   describe how two other physical properties of transition elements are different from those of  group i elements.  1  .  2  .  [2]",
            "10": "10 0620/42/o/n/21 \u00a9 ucles 2021  (d)  chemical properties of some group i elements are shown in the table. element reaction with cold water reaction with oxygenflame test colour lithium \u25cf steadily effervesces  \u25cf forms a colourless solutionvery slowly forms an oxide layer red sodium \u25cf strongly effervesces  \u25cf forms a colourless solutionslowly forms an oxide layer potassium \u25cf very strongly effervesces  \u25cf forms a colourless solutionquickly forms an oxide layer rubidium ruby red  (i)  add to the table:  \u25cf the flame test colours for sodium and potassium  \u25cf the predicted reactions of rubidium with water and with oxygen.  [4]  (ii)  name the gas produced when group i elements react with water.   ...   [1]  (iii)  name the solution formed when potassium reacts with water.   ...   [1]  (iv)  predict the ph of the colourless solution formed when potassium reacts with water.   ...   [1]  (v)  write the chemical equation for the reaction of sodium with oxygen.   ...   [2]  (e)  iron is a typical transition element. it is the catalyst used in the haber process.  (i)  write the equation for the reaction that occurs in the haber process.   ...   [2]  (ii)  state the temperature and pressure used in the haber process. include units.  temperature    pressure  ..  [2]  [total: 22]",
            "11": "11 0620/42/o/n/21 \u00a9 ucles 2021 [turn over 6  ethanol, c2h5oh, belongs to the homologous series called alcohols.  (a)  write the general formula of alcohols.   ..   [1]  (b)  explain why ethanol cannot be described as a hydrocarbon.   ..   [1]  (c)  ethanol can be manufactured from different substances by reaction with steam or by  fermentation.  (i)  give the formula of the substance which reacts with steam to form ethanol.   ...   [1]  (ii)  name a substance which will undergo fermentation to form ethanol.   ...   [1]  (d)  ethanol is a fuel.   write the chemical equation for the complete combustion of ethanol.   ..   [2]",
            "12": "12 0620/42/o/n/21 \u00a9 ucles 2021  (e)  ethane-1,2-diol has two alcohol functional groups. och hh c hh ho   one molecule of ethane-1,2-diol will react with two molecules of ethanoic acid to form  molecule x.   x has two ester functional groups and a molecular formula of c6h10o4.  (i)  state the empirical formula of x.   ...   [1]  (ii)  draw the structure of x.   show all of the atoms and all of the bonds.  [2]  (iii)  name the other substance formed in this reaction.   ...   [1]  (f)  each alcohol functional group in ethane-1,2-diol reacts with acidified potassium manganate( vii)  to form a different organic compound, y.  (i)  name the functional groups formed in y.   ...   [1]  (ii)  draw the structure of y.   show all of the atoms and all of the bonds.  [1]  [total: 12]",
            "13": "13 0620/42/o/n/21 \u00a9 ucles 2021blank page",
            "14": "14 0620/42/o/n/21 \u00a9 ucles 2021blank page",
            "15": "15 0620/42/o/n/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/42/o/n/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w21_qp_43.pdf": {
            "1": "*6388004630* chemistry  0620/43 paper 4 theory (extended) october/november 2021  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib21 11_0620_43/3rp \u00a9 ucles 2021 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/43/o/n/21 \u00a9 ucles 2021 1  a list of substances is shown. ammonia bauxite carbon dioxide carbon monoxide ethanol hematite oxygen sodium chloride sulfur dioxide   answer the questions using the list of substances.   each substance may be used once, more than once or not at all.   state which substance is:  (a)  an element  ...   [1]  (b)  an ore of aluminium  .   [1]  (c)  a gas that causes acid rain  ..   [1]  (d)  used as a fuel  ..   [1]  (e)  an ionic compound  ..   [1]  (f)  produced in the haber process  ...   [1]  (g)  a product of respiration     [1]  (h)  a toxic product of the incomplete combustion of hydrocarbons   ..   [1]  (i)  a gas produced in the test for nitrate ions.  ..   [1]  [total: 9]",
            "3": "3 0620/43/o/n/21 \u00a9 ucles 2021 [turn over 2  this question is about electrolysis.  (a)  state the meaning of the term electrolyte .      ..   [2]  (b)  the table gives information about the electrolysis of two electrolytes. carbon (graphite)  electrodes are used in each experiment.  (i)  complete the table to show the observations and products of electrolysis. positive electrode (anode) negative electrode (cathode) electrolyte observations name of product observations name of product aqueous copper( ii) sulfatecolourless bubbles concentrated aqueous  sodium bromidecolourless bubbleshydrogen  [5]  (ii)  hydrogen is produced at the negative electrode (cathode) during the electrolysis of  concentrated aqueous sodium bromide.   write the ionic half-equation for this reaction.   ...   [2]  (iii)  state two reasons why carbon (graphite) is suitable to use as an electrode.  1  ..  2  ..  [2]  (iv)  name the particle responsible for the conduction of electricity in the metal wires used in a  circuit.   ...   [1]  [total: 12]",
            "4": "4 0620/43/o/n/21 \u00a9 ucles 2021 3  lead is a metallic element in group iv. one of the ores of lead is galena, which is an impure form  of lead( ii)\u00a0sulfide,\u00a0pbs.   lead also occurs in the ore cerussite, which contains lead( ii)\u00a0carbonate,\u00a0pbco3.  (a)  calculate the relative formula mass, mr,\u00a0of\u00a0pbco3.  mr\u00a0of\u00a0pbco3 = ..  [1]  (b)  the mr\u00a0of\u00a0pbs\u00a0is\u00a0239. \u00a0 \u00a0calculate\u00a0the\u00a0percentage\u00a0of\u00a0lead\u00a0by\u00a0mass\u00a0in\u00a0pbs. \u00a0 percentage\u00a0of\u00a0lead\u00a0by\u00a0mass\u00a0in\u00a0pbs\u00a0=\u00a0..\u00a0\u00a0[1]  (c)\u00a0 \u00a0the\u00a0percentage\u00a0of\u00a0lead\u00a0by\u00a0mass\u00a0in\u00a0pbco3 is 77.5%.   use this information  and your answer to (b) to suggest whether it would be better to extract  lead\u00a0from\u00a0pbco3\u00a0or\u00a0pbs.   give a reason for your answer.      ..   [1]  (d)  when lead( ii) carbonate is heated it decomposes into lead( ii)\u00a0oxide,\u00a0pbo,\u00a0and\u00a0carbon\u00a0dioxide.   write a chemical equation for this reaction.   ..   [1]  (e)  lead( ii) carbonate reacts with dilute nitric acid. one of the products is aqueous lead( ii) nitrate,  pb(no3)2.   write a chemical equation for this reaction.   ..   [2]",
            "5": "5 0620/43/o/n/21 \u00a9 ucles 2021 [turn over  (f)  lead( ii) oxide and carbon dioxide are oxides of group iv elements.  (i)  complete the diagram to show the electron arrangement in one molecule of co2.   show only the outer electrons. o o c  [2]  (ii)  the melting points of lead( ii) oxide and carbon dioxide are shown. melting point / \u00b0c lead( ii) oxide 886 carbon dioxide \u201356   use your knowledge of structure and bonding to explain why lead( ii) oxide has a much  higher melting point than carbon dioxide.   your answer should refer to:  \u25cf the types of particles involved  \u25cf the relative strength of the forces of attraction between the particles.   .   .   .   ...   [3]",
            "6": "6 0620/43/o/n/21 \u00a9 ucles 2021  (g)\u00a0 \u00a0part\u00a0of\u00a0the\u00a0reactivity\u00a0series\u00a0is\u00a0shown. magnesium most reactive lead copper least reactive   aqueous lead( ii)\u00a0nitrate\u00a0contains\u00a0pb2+ ions.   two experiments are carried out.   in experiment 1, magnesium is added to aqueous lead( ii) nitrate.   in experiment 2, copper is added to aqueous lead( ii) nitrate.   write an ionic equation for any reaction that occurs in each experiment. if no reaction occurs  write \u2018no reaction\u2019.   experiment 1  .   experiment 2  .  [2]  (h)  when lead( ii) nitrate is heated it decomposes to produce the same gaseous products as when  copper( ii) nitrate is heated.  (i)  one of the gaseous products is oxygen.   describe a test for oxygen.  test  ..  observations  ...  [2]  (ii)  name the other gaseous product.   ...   [1]  [total: 16]",
            "7": "7 0620/43/o/n/21 \u00a9 ucles 2021 [turn over 4  carbon is an important element.  (a)  carbon exists as the isotopes 12c6 and 13c6.   complete the table. isotopenumber of protons in one atomnumber of electrons in one atomnumber of neutrons in one atom 12c6 13c6  [2]  (b)  name two forms of the element carbon which have giant covalent structures.  ... and  ...   [1]  (c)  the avogadro constant is the number of particles in 1 mole.   the numerical value of the avogadro constant is 6.02 \u00d7 1023.  (i)  calculate the number of molecules in 22.0 g of carbon dioxide, co2.  ... molecules  [2]  (ii)  calculate the number of molecules in 6.00 dm3 of carbon dioxide gas at room temperature  and pressure.  ... molecules  [1]  [total: 6]",
            "8": "8 0620/43/o/n/21 \u00a9 ucles 2021 5 (a)  dilute sulfuric acid and aqueous sodium hydroxide can be used to prepare sodium sulfate  crystals using a method that involves titration. 25.0  cm3 aqueou s sodium hydroxid econical flas kdilute sulfuric acid  (i)  suggest why universal indicator is not suitable for this titration.   ...   [1]  (ii)  name an indicator that can be used in this titration.   ...   [1]   20.0 cm3 of dilute sulfuric acid neutralises 25.0 cm3 of 1.00 mol / dm3 aqueous sodium hydroxide.  at\u00a0the\u00a0end\u00a0of\u00a0the\u00a0titration\u00a0the\u00a0conical\u00a0flask\u00a0contains\u00a0aqueous\u00a0sodium\u00a0sulfate\u00a0 with\u00a0the\u00a0dissolved\u00a0 indicator as an impurity.  (b)  describe how to prepare a pure sample of sodium sulfate crystals from the original solutions  of dilute sulfuric acid and aqueous sodium hydroxide of the same concentrations.   you are not required to give details of how to carry out the titration.                           ..   [5]",
            "9": "9 0620/43/o/n/21 \u00a9 ucles 2021 [turn over  (c)  sodium hydrogensulfate, nahso4, dissolves in water to produce an aqueous solution, x,  containing na+, h+ and so42\u2013 ions.   state the observations when the following tests are done.  (i)\u00a0 \u00a0a\u00a0flame\u00a0test\u00a0is\u00a0carried\u00a0out\u00a0on\u00a0x.   ...   [1]  (ii)  copper( ii) oxide is warmed with an excess of x.   .   ...   [2]  (iii)\u00a0 \u00a0acidified\u00a0aqueous\u00a0barium\u00a0nitrate\u00a0is\u00a0added\u00a0to\u00a0x.   ...   [1]  [total: 11]",
            "10": "10 0620/43/o/n/21 \u00a9 ucles 2021 6  a student investigates the decomposition of hydrogen peroxide in the presence of a catalyst of  manganese( iv) oxide. 2h2o2(aq)  \u2192  2h2o(l)  +  o2(g)  (a)  state the meaning of the term catalyst.      ..   [2]  (b)  the diagram shows the equipment the student uses. aqueou s hydrogen peroxid ecotton wool balanc ecatalyst of manganese( iv) oxide   the student uses this method:  \u25cf the catalyst is added to the aqueous hydrogen peroxide  \u25cf the stop-clock is started  \u25cf the mass of the flask and contents is recorded at regular time intervals.",
            "11": "11 0620/43/o/n/21 \u00a9 ucles 2021 [turn over \u00a0 \u00a0a\u00a0graph\u00a0of\u00a0the\u00a0mass\u00a0of\u00a0the\u00a0flask\u00a0and\u00a0contents\u00a0against\u00a0time\u00a0is\u00a0shown. mass of the flask and contents  / g time  / s  (i)\u00a0 \u00a0suggest\u00a0why\u00a0the\u00a0mass\u00a0of\u00a0the\u00a0flask\u00a0and\u00a0contents\u00a0decreases\u00a0as\u00a0time\u00a0increases.   ...   [1]  (ii)  describe what happens to the rate of the reaction as time increases.   .   ...   [2]  (c)  the student repeats the experiment at a higher temperature. all other conditions stay the  same. the rate of reaction increases.  (i)  explain, in terms of collisions between particles, why the rate of reaction increases at a  higher temperature.   .   .   .   ...   [3]  (ii)  draw a line on the graph in (b) for the experiment at a higher temperature. [2]  [total: 10]",
            "12": "12 0620/43/o/n/21 \u00a9 ucles 2021 7 (a)  ethanol is a member of the homologous series of alcohols.   give two characteristics of members of a homologous series.  1  .  2  .  [2]  (b)  ethanol can be manufactured from ethene.   ethene can be made from long chain hydrocarbons such as decane, c10h22.   ethene is then converted into ethanol.  (i)  name the process used to obtain ethene from long chain hydrocarbons such as decane,  c10h22.   ...   [1]  (ii)  complete the chemical equation to show the formation of ethene from decane, c10h22.  c10h22  \u2192  c4h8  +  ...  +  ... [2]  (iii)  write the chemical equation for the conversion of ethene into ethanol.   ...   [1]  (iv)  name the type of reaction occurring when ethene is converted into ethanol.   ...   [1]  (v)  give one condition for the reaction in which ethene is converted into ethanol.   ...   [1]  (c)  ethanol can also be produced by fermentation of carbohydrates such as glucose.   give two advantages of manufacturing ethanol by fermentation compared to manufacturing  ethanol from ethene.  1  .  2  .  [2]",
            "13": "13 0620/43/o/n/21 \u00a9 ucles 2021 [turn over  (d) (i)  under certain conditions ethene can react with chlorine to produce chloroethene.   the structure of chloroethene is shown. ch hch cl   the equation for the chemical reaction is shown. c2h4  +  c l 2  \u2192  c2h3cl  +  hcl   state the type of chemical reaction between ethene and chlorine that this equation shows.   ...   [1]  (ii)  chloroethene monomers can be converted into a polymer called poly(chloroethene).   state the type of polymerisation that produces poly(chloroethene) from chloroethene.   ...   [1]  (iii)  draw a section of the poly(chloroethene) molecule made from two monomer molecules.  [2]",
            "14": "14 0620/43/o/n/21 \u00a9 ucles 2021  (e)  the structure of part of a polymer is shown. n co n h hco co n h   this polymer is made from one type of monomer only.   complete the diagram to show the structure of the monomer used to produce this polymer.   show all of the atoms and all of the bonds in the functional groups.  [2]  [total: 16]",
            "15": "15 0620/43/o/n/21 \u00a9 ucles 2021permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge. blank page",
            "16": "16 0620/43/o/n/21 \u00a9 ucles 2021 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_w21_qp_51.pdf": {
            "1": "*4998819063* chemistry  0620/51 paper 5 practical test october/november 2021  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib21 11_0620_51/fp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/51/o/n/21 \u00a9 ucles 2021 1\t\tyou\tare\tgoing\tto\tinvestigate\t the\ttemperature\t change\twhen\tzinc\treacts\twith\ttwo\tdifferent\t aqueous\t solutions of copper( ii) sulfate, solution q and solution r.   read all of the instructions carefully before starting the experiments.   instructions   you are going to do two experiments.  (a)  experiment 1  \u25cf place a polystyrene cup into a 250 cm3 beaker for support.  \u25cf use a measuring cylinder to pour 25 cm3 of solution q into the polystyrene cup.  \u25cf use a thermometer to measure the initial temperature of solution q. record this in the  space above the table.  \u25cf add 3 g of zinc powder to the polystyrene cup. at the same time start a stop\u2011watch.  \u25cf using the thermometer, continually stir the mixture in the polystyrene cup. record the  temperature every 30 seconds for 240 seconds. record the temperatures in the table.  initial temperature = .. \u00b0c time / s 30 60 90 120 150 180 210 240 temperature / \u00b0c temperature change / \u00b0c  \u25cf complete the table by calculating the temperature changes from the initial temperature  using\tthe\tequation: temperature change = temperature \u2013 initial temperature  [3]  (b)  experiment 2  \u25cf empty the polystyrene cup and rinse with distilled water.  \u25cf repeat experiment 1 using solution r in place of solution q.  \u25cf complete the table by calculating the temperature changes from the initial temperature.  initial temperature = .. \u00b0c time / s 30 60 90 120 150 180 210 240 temperature / \u00b0c temperature change / \u00b0c  [3]",
            "3": "3 0620/51/o/n/21 \u00a9 ucles 2021 [turn over  (c)  complete a suitable scale on the y\u2011axis and plot your results from experiment 1 and experiment 2  on\tthe\tgrid.\tdraw\ttwo\tcurves\tof\tbest\tfit.\tboth\tcurves\tmust\tstart\tat\t(0,0).\tlabel\tyour\tcurves. 00 50 100 150 200 250 time  / stemperature change  / /g113c  [5]  (d)  from your graph , deduce the temperature change at 110 seconds in experiment 1.   show clearly on the grid  how you worked out your answer.   .. \u00b0c [2]  (e)  predict the temperature of the solution in experiment 2 after 5 hours. explain your answer.      ..   [2]",
            "4": "4 0620/51/o/n/21 \u00a9 ucles 2021  (f) (i)  suggest why the experiments were done in a polystyrene cup rather than a glass beaker.   ...   [1]  (ii)\t\tdescribe\t how\tthe\tresults\twould\tbe\tdifferent\t if\ta\tglass\tbeaker\tis\tused\tin\tplace\tof\tthe\t polystyrene cup.   ...   [1]  (g)  suggest one change that could be made to the apparatus that would improve the accuracy of  the results. explain why this change would improve the accuracy of the results.  change  ...  explanation       [2] \t [total:\t19]",
            "5": "5 0620/51/o/n/21 \u00a9 ucles 2021 [turn over 2  you are provided with solid s and solid t.   do the following tests on the substances, recording all of your observations at each stage.   tests on solid s  (a)  to solid s in the boiling tube, add about 10 cm3 of dilute hydrochloric acid.   test any gas produced.   keep the product for (b).   record your observations.      ..   [2]  (b) the solution formed in (a) is solution u. decant about 1 cm depth of solution u into a test\u2011tube.   to solution u\tadd\taqueous\tsodium\thydroxide\tdropwise\tand\tthen\tin\texcess.   record your observations.      ..   [2]  (c)  identify solid s.      ..   [2]",
            "6": "6 0620/51/o/n/21 \u00a9 ucles 2021  tests on solid t  (d)  to solid t in the boiling tube, add about 10 cm3 of distilled water. place a stopper in the boiling  tube and shake the tube to dissolve solid t and form solution t.   divide solution t\tinto\tfour\tapproximately\tequal\tportions\tin\tfour\ttest-tubes.  (i)\t\tto\tthe\tfirst\tportion\tof\tsolution\t t,\tadd\taqueous\t sodium\thydroxide\t dropwise\t and\tthen\tin\t excess.   record your observations.   .   ...   [2]  (ii)  pour the second portion of solution t into the test\u2011tube containing sodium carbonate.   record your observations.   .   ...   [2]  (iii)  to the third portion of solution t, add a 2 cm length of magnesium ribbon.   record your observations.   ...   [2]  (iv)  to the fourth portion of solution t, add 1 cm depth of dilute nitric acid followed by a few  drops\tof\taqueous\tsilver\tnitrate.\tleave\tthe\tmixture\tto\tstand\tfor\t5\tminutes.   record your observations.   ...   [1]  (e)  identify solid t.      ..   [2] \t [total:\t15]",
            "7": "7 0620/51/o/n/21 \u00a9 ucles 2021 [turn over 3  catalysts are substances which increase the rate of a reaction but are unchanged at the end of the  reaction. \t\taqueous\thydrogen\tperoxide\tdecomposes\tslowly \tto\tform\twater\tand\toxygen. 2h2o2(aq)\t\t\u2192  2h2o(l)  +  o2(g)   copper( ii) oxide is an insoluble solid. \t\tplan\tan\tinvestigation\t to\tfind\tout\tif\tcopper( ii) oxide is a catalyst for the decomposition of  hydrogen peroxide. you must include how your results will tell you if copper( ii) oxide is a catalyst.  you have access to copper( ii)\toxide,\taqueous\t hydrogen\t peroxide\t and\tall\tnormal\tlaboratory\t apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/51/o/n/21 \u00a9 ucles 2021blank page",
            "9": "9 0620/51/o/n/21 \u00a9 ucles 2021blank page",
            "10": "10 0620/51/o/n/21 \u00a9 ucles 2021blank page",
            "11": "11 0620/51/o/n/21 \u00a9 ucles 2021notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/51/o/n/21 \u00a9 ucles 2021tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w21_qp_52.pdf": {
            "1": "*4983814551* chemistry  0620/52 paper 5 practical test october/november 2021  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib21 11_0620_52/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/52/o/n/21 \u00a9 ucles 2021 1\t\tyou\tare\tgoing\tto\tinvestigate\t the\treaction\t between \ttwo\tdifferent\t solutions\t of\taqueous\t   sodium\t carbonate,\t labelled\t solution\t k\tand\tsolution\t l,\tand\ttwo\tdifferent\t solutions\t of\tdilute\t hydrochloric\tacid,\tlabelled\tacid\t m and acid n.   read all of the instructions carefully before starting the experiments.   instructions   you are going to do three experiments.  (a)  experiment 1  \u25cf\tfill\tthe\tburette\twith\tsolution\tk.\trun\tsome\tof\tsolution\t k\tout\tof\tthe\tburette\tso\tthat\tthe\tlevel\t of\tsolution\tk\tis\ton\tthe\tburette\tscale.  \u25cf\tuse\tthe\tmeasuring\tcylinder\tto\tpour\t25\t cm3\tof\tacid\tm\tinto\tthe\tconical\tflask.  \u25cf\tadd\tfive\tdrops\tof\tmethyl\torange\tindicator\tto\tthe\tconical\tflask.  \u25cf\tstand\tthe\tconical\tflask\ton\ta\twhite\ttile.  \u25cf\tslowly\tadd\tsolution\t k\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tswirling\tthe\tflask,\tuntil\tthe\t solution\tjust\tchanges\tcolour.  \u25cf\trecord\tthe\tburette\treadings\tin\tthe\ttable\tand\tcomplete\tthe\ttable. experiment 1 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tsolution\t k\tadded\t /\tcm3   experiment 2  \u25cf\tempty\tthe\tconical\tflask\tand\trinse\tit\twith\tdistilled\twater.  \u25cf\trefill\tthe\tburette\twith\tsolution\t k.\trun\tsome\tof\tsolution\tk\tout\tof\tthe\tburette\tso\tthat\tthe\tlevel\t of\tsolution\tk\tis\ton\tthe\tburette\tscale.  \u25cf\tuse\tthe\tmeasuring\tcylinder\tto\tpour\t25\t cm3\tof\tacid\tn\tinto\tthe\tconical\tflask.  \u25cf\tadd\tfive\tdrops\tof\tmethyl\torange\tindicator\tto\tthe\tconical\tflask.  \u25cf\tstand\tthe\tconical\tflask\ton\ta\twhite\ttile.  \u25cf\tslowly\tadd\tsolution\t k\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tswirling\tthe\tflask,\tuntil\tthe\t solution\tjust\tchanges\tcolour.  \u25cf\trecord\tthe\tburette\treadings\tin\tthe\ttable\tand\tcomplete\tthe\ttable. experiment\t2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tsolution\t k\tadded\t /\tcm3",
            "3": "3 0620/52/o/n/21 \u00a9 ucles 2021 [turn over   experiment 3  \u25cf\tempty\tthe\tburette\tand\trinse\tit\twith\tdistilled\twater.  \u25cf\tempty\tthe\tconical\tflask\tand\trinse\tit\twith\tdistilled\twater.  \u25cf\tfill\tthe\tburette\twith\tsolution\tl.\trun\tsome\tof\tsolution\t l\tout\tof\tthe\tburette\tso\tthat\tthe\tlevel\t of\tsolution\tl\tis\ton\tthe\tburette\tscale.  \u25cf\tuse\tthe\tmeasuring\tcylinder\tto\tpour\t25\t cm3\tof\tacid\tn\tinto\tthe\tconical\tflask.  \u25cf\tadd\tfive\tdrops\tof\tmethyl\torange\tindicator\tto\tthe\tconical\tflask.  \u25cf\tstand\tthe\tconical\tflask\ton\ta\twhite\ttile.  \u25cf\tslowly\tadd\tsolution\t l\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tswirling\tthe\tflask,\tuntil\tthe\t solution\tjust\tchanges\tcolour.  \u25cf\trecord\tthe\tburette\treadings\tin\tthe\ttable\tand\tcomplete\tthe\ttable. experiment 3 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tsolution\t l\tadded\t /\tcm3 \t [5]  (b)\t\tstate\tthe\tcolour\tchange\tobserved\tat\tthe\tend-point\tin\tthe\tconical\tflask\tin\texperiment\t1. \t \tfrom\t...\tto\t  ... \t [1]  (c)  describe one other\tobservation\tmade\twhen\tsolution\t k is added to acid m in experiment 1.   .. \t\t[1]  (d) (i)\t \tcompare\tthe\tvolumes\tof\tsolution\t k\tused\tin\texperiment\t1\tand\texperiment\t2.   .   ... \t\t[2]  (ii)\t\tsuggest\t why\tdifferent\tvolumes\t of\tsolution\t k\twere\tneeded\tin\texperiment\t 1\tand\texperiment\t 2.   ... \t\t[1]  (e)\t\tdeduce\t the\tvolume\tof\tsolution\t l\trequired\t to\treach\tthe\tend-point\t if\texperiment\t 3\tis\trepeated\t using acid m\tin\tplace\tof\tacid\t n. \t volume\tof\tsolution\t l = .. cm3\t\t[1]",
            "4": "4 0620/52/o/n/21 \u00a9 ucles 2021  (f)\t\texplain\twhy\tthe\tconical\tflask\twas\trinsed\twith\twater\tat\tthe\tstart\tof\texperiment\t 2\tand\texperiment\t 3.   .. \t\t[1]  (g)\t\tat\tthe\tstart\tof\texperiment\t3\tthe\tburette\twas\trinsed\twith\twater. \t \tdescribe\t an\tadditional\t step\tthat\tshould\thave\tbeen\tdone\tafter\trinsing\tthe\tburette\twith\twater\tbut\t before\tfilling\tthe\tburette\twith\tsolution\t l.\texplain\tyour\tanswer.      .. \t\t[2]  (h)\t\texplain\twhy\tthe\tconical\tflask\tis\tplaced\ton\ta\twhite\ttile.   .. \t\t[1]  (i)\t\tdescribe\thow\tthe\treliability\tof\tthe\tresults\tof\tthe\texperiments\tcan\tbe\tconfirmed.      .. \t\t[1]  (j)  state one\tsource\tof\terror\tin\texperiment\t1.\tsuggest\tan\timprovement\tto\treduce\tthis\terror. \t source\tof\terror\t ...  improvement  .. \t [2] \t [total:\t18]",
            "5": "5 0620/52/o/n/21 \u00a9 ucles 2021 [turn over 2\t\tyou\tare\tprovided\twith\tsolid\t o\tand\tliquid\t p. \t\tdo\tthe\tfollowing\ttests\ton\tthe\ttwo\tsubstances,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.   tests on solid o  (a)\t\tuse\ta\tspatula\tto\ttransfer\tapproximately\tone\tthird\tof \tsolid\to\tto\ta\tboiling\ttube. \t \theat\tthe\tboiling\ttube\tgently\tand\tthen\tstrongly.   record your observations.      .. \t\t[2] \t\tplace\tthe\tremaining\t solid\t o\tin\ta\tboiling\ttube.\tadd\tabout\t10\tcm3\tof\tdistilled\twater\tto\tthe\tboiling\ttube.\t place\ta\tstopper\tin\tthe\tboiling\ttube\tand\tshake\tthe\ttube\tto\tdissolve\tsolid\t o\tand\tform\tsolution\t o. \t\tdivide\tsolution\t o\tinto\tthree\tapproximately\tequal\t portions\tin\tone\tboiling \ttube\tand\ttwo\ttest-tubes.  (b)\t\tto\tthe\tfirst\tportion\tof\tsolution\t o,\tin\tthe\tboiling\ttube,\tadd\tapproximately\t 2\tcm3\tof\taqueous\t sodium hydroxide.   keep the product for part (c).   record your observations.   .. \t\t[1]  (c)\t\twarm\tthe\tproduct\tfrom\t(b). test any gas produced.   record your observations. \t \tidentify\tthe\tgas\tproduced.  observations  .. \t identity\tof\tgas\t  \t [2]  (d)\t\tto\tthe\tsecond\tportion\tof\tsolution\t o\tadd\tabout\t1\tcm\tdepth\tof\tdilute\tnitric\tacid\tfollowed\t by\ta\tfew\t drops\tof\taqueous\tsilver\tnitrate.   record your observations.   .. \t\t[1]  (e)\t\tto\tthe\tthird\tportion\tof\tsolution\t o,\tadd\tthe\taqueous\tchlorine.   record your observations.   .. \t\t[1]  (f)\t\tidentify\tsolid\to.      .. \t\t[2]",
            "6": "6 0620/52/o/n/21 \u00a9 ucles 2021   tests on liquid p  (g)\t\tadd\ta\tfew\tdrops\tof\tliquid\t p\tto\tthe\ttest-tube\t containing\t aqueous\t bromine.\t replace\t the\tstopper\t in\tthe\ttest-tube\tand\tshake\tthe\ttest-tube.   record your observations.      .. \t\t[2]  (h)\t\tadd\ta\tfew\tdrops\tof\tliquid\t p\tto\ta\tcrucible.\t apply\ta\tlighted\tsplint\tto\tthe\tsurface\tof\tliquid\t p in the  crucible.   record your observations.      .. \t\t[1]  (i)\t\tto\tthe\tremaining\t liquid\t p\tadd\ta\tfew\tdrops\tof\taqueous\t alkaline\t potassium\t manganate( vii).  replace\t the\tstopper\tin\tthe\ttest-tube\t and\tshake\tthe\ttest-tube.\t leave\tthe\ttest-tube\t to\tstand\tfor\t a\tfew\tminutes.   record your observations.   .. \t\t[2]  (j)\t\tstate\twhat\tconclusions\tcan\tbe\tmade\tabout\tliquid\t p.      .. \t\t[2] \t [total:\t16]",
            "7": "7 0620/52/o/n/21 \u00a9 ucles 2021 [turn over 3\t\tcobalt\tis\ta\tmetal.\tcobalt\tis\tbetween\t copper\tand\tiron\tin\tthe\treactivity\t series.\tthe\tmineral\t   spherocobaltite\t contains\t the\tcompound\t cobalt( ii)\tcarbonate\t and\tno\tother\tmetal\tions.\t cobalt( ii)\tcarbonate\t is\tinsoluble\t in\twater\tand\treacts\twith\tdilute\tacids\tto\tform\tan\taqueous\t solution\t of\ta\tsalt. \t\tdescribe\t how\tyou\twould\tobtain\ta\tsample\tof\tcobalt\tmetal\tstarting\twith\ta\tlarge\tlump\tof\tspherocobaltite. \t you\thave\taccess\tto\tall\tnormal\tlaboratory\tapparatus\tand\tchemicals.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   . \t\t[6]",
            "8": "8 0620/52/o/n/21 \u00a9 ucles 2021blank page",
            "9": "9 0620/52/o/n/21 \u00a9 ucles 2021blank page",
            "10": "10 0620/52/o/n/21 \u00a9 ucles 2021blank page",
            "11": "11 0620/52/o/n/21 \u00a9 ucles 2021notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/52/o/n/21 \u00a9 ucles 2021tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w21_qp_53.pdf": {
            "1": "*5052730359* chemistry  0620/53 paper 5 practical test october/november 2021  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib21 11_0620_53/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/53/o/n/21 \u00a9 ucles 2021 1\t\tyou\tare\tgoing\tto\tinvestigate\t the\ttemperature\t change\twhen\tzinc\treacts\twith\ttwo\tdifferent\t aqueous\t solutions of copper( ii) sulfate, solution q and solution r.   read all of the instructions carefully before starting the experiments.   instructions   you are going to do two experiments.  (a)  experiment 1  \u25cf place a polystyrene cup into a 250 cm3 beaker for support.  \u25cf use a measuring cylinder to pour 25 cm3 of solution q into the polystyrene cup.  \u25cf use a thermometer to measure the initial temperature of solution q. record this in the  space above the table.  \u25cf add 3 g of zinc powder to the polystyrene cup. at the same time start a stop\u2011watch.  \u25cf using the thermometer, continually stir the mixture in the polystyrene cup. record the  temperature every 30 seconds for 240 seconds. record the temperatures in the table.  initial temperature = .. \u00b0c time / s 30 60 90 120 150 180 210 240 temperature / \u00b0c temperature change / \u00b0c  \u25cf complete the table by calculating the temperature changes from the initial temperature  using\tthe\tequation: temperature change = temperature \u2013 initial temperature  [3]  (b)  experiment 2  \u25cf empty the polystyrene cup and rinse with distilled water.  \u25cf repeat experiment 1 using solution r in place of solution q.  \u25cf complete the table by calculating the temperature changes from the initial temperature.  initial temperature = .. \u00b0c time / s 30 60 90 120 150 180 210 240 temperature / \u00b0c temperature change / \u00b0c  [3]",
            "3": "3 0620/53/o/n/21 \u00a9 ucles 2021 [turn over  (c)  complete a suitable scale on the y\u2011axis and plot your results from experiment 1 and experiment 2  on\tthe\tgrid.\tdraw\ttwo\tcurves\tof\tbest\tfit.\tboth\tcurves\tmust\tstart\tat\t(0,0).\tlabel\tyour\tcurves. 00 50 100 150 200 250 time  / stemperature change  / /g113c  [5]  (d)  from your graph , deduce the temperature change at 110 seconds in experiment 1.   show clearly on the grid  how you worked out your answer.   .. \u00b0c [2]  (e)  predict the temperature of the solution in experiment 2 after 5 hours. explain your answer.      ..   [2]",
            "4": "4 0620/53/o/n/21 \u00a9 ucles 2021  (f) (i)  suggest why the experiments were done in a polystyrene cup rather than a glass beaker.   ...   [1]  (ii)\t\tdescribe\t how\tthe\tresults\twould\tbe\tdifferent\t if\ta\tglass\tbeaker\tis\tused\tin\tplace\tof\tthe\t polystyrene cup.   ...   [1]  (g)  suggest one change that could be made to the apparatus that would improve the accuracy of  the results. explain why this change would improve the accuracy of the results.  change  ...  explanation       [2] \t [total:\t19]",
            "5": "5 0620/53/o/n/21 \u00a9 ucles 2021 [turn over 2  you are provided with solid s and solid t.   do the following tests on the substances, recording all of your observations at each stage.   tests on solid s  (a)  to solid s in the boiling tube, add about 10 cm3 of dilute hydrochloric acid.   test any gas produced.   keep the product for (b).   record your observations.      ..   [2]  (b) the solution formed in (a) is solution u. decant about 1 cm depth of solution u into a test\u2011tube.   to solution u\tadd\taqueous\tsodium\thydroxide\tdropwise\tand\tthen\tin\texcess.   record your observations.      ..   [2]  (c)  identify solid s.      ..   [2]",
            "6": "6 0620/53/o/n/21 \u00a9 ucles 2021  tests on solid t  (d)  to solid t in the boiling tube, add about 10 cm3 of distilled water. place a stopper in the boiling  tube and shake the tube to dissolve solid t and form solution t.   divide solution t\tinto\tfour\tapproximately\tequal\tportions\tin\tfour\ttest-tubes.  (i)\t\tto\tthe\tfirst\tportion\tof\tsolution\t t,\tadd\taqueous\t sodium\thydroxide\t dropwise\t and\tthen\tin\t excess.   record your observations.   .   ...   [2]  (ii)  pour the second portion of solution t into the test\u2011tube containing sodium carbonate.   record your observations.   .   ...   [2]  (iii)  to the third portion of solution t, add a 2 cm length of magnesium ribbon.   record your observations.   ...   [2]  (iv)  to the fourth portion of solution t, add 1 cm depth of dilute nitric acid followed by a few  drops\tof\taqueous\tsilver\tnitrate.\tleave\tthe\tmixture\tto\tstand\tfor\t5\tminutes.   record your observations.   ...   [1]  (e)  identify solid t.      ..   [2] \t [total:\t15]",
            "7": "7 0620/53/o/n/21 \u00a9 ucles 2021 [turn over 3  catalysts are substances which increase the rate of a reaction but are unchanged at the end of the  reaction. \t\taqueous\thydrogen\tperoxide\tdecomposes\tslowly \tto\tform\twater\tand\toxygen. 2h2o2(aq)\t\t\u2192  2h2o(l)  +  o2(g)   copper( ii) oxide is an insoluble solid. \t\tplan\tan\tinvestigation\t to\tfind\tout\tif\tcopper( ii) oxide is a catalyst for the decomposition of  hydrogen peroxide. you must include how your results will tell you if copper( ii) oxide is a catalyst.  you have access to copper( ii)\toxide,\taqueous\t hydrogen\t peroxide\t and\tall\tnormal\tlaboratory\t apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/53/o/n/21 \u00a9 ucles 2021blank page",
            "9": "9 0620/53/o/n/21 \u00a9 ucles 2021blank page",
            "10": "10 0620/53/o/n/21 \u00a9 ucles 2021blank page",
            "11": "11 0620/53/o/n/21 \u00a9 ucles 2021notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/53/o/n/21 \u00a9 ucles 2021tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w21_qp_61.pdf": {
            "1": "*6975746068* chemistry  0620/61 paper 6 alternative to practical october/november 2021  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib21 11_0620_61/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/61/o/n/21 \u00a9 ucles 2021 1  a student investigated the volume of dilute sulfuric acid that would react with 25.0 cm3 of aqueous  sodium carbonate.  \u25cf a burette was rinsed with water and then with dilute sulfuric acid.  \u25cf the burette was filled with dilute sulfuric acid. some of the dilute sulfuric acid was run out of  the burette so that the level of the dilute sulfuric acid was on the burette scale.  \u25cf 25.0 cm3 of aqueous sodium carbonate was poured into the apparatus labelled a in the diagram.  \u25cf five drops of methyl orange indicator were added to the aqueous sodium carbonate in a.  \u25cf the apparatus labelled a was placed on a white tile.  \u25cf the dilute sulfuric acid was added slowly to the 25.0 cm3 of aqueous sodium carbonate until  the colour of the methyl orange changed from yellow to orange.   the apparatus was arranged as shown in the diagram. aqueou s sodium carbonateaburette white tiledilute sulfuric aci d  (a)  name the apparatus labelled a.   ..   [1]  (b)  state one safety precaution that should be taken when using dilute sulfuric acid.   ..   [1]  (c)  give a reason why the white tile is used.   ..   [1]  (d)  describe what should be done to the apparatus labelled a as the dilute sulfuric acid is added  to the aqueous sodium carbonate.   ..   [1]",
            "3": "3 0620/61/o/n/21 \u00a9 ucles 2021 [turn over  (e)  state why the burette was rinsed with water and then with dilute sulfuric acid at the start of the  experiment.  water  ..     dilute sulfuric acid  ..     [2]  [total: 6]",
            "4": "4 0620/61/o/n/21 \u00a9 ucles 2021 2  a student investigated the rate of reaction between small lumps of calcium carbonate and dilute  hydrochloric acid. \t\tthe\texperiment\t was\tdone\tat\ttwo\tdifferent\t temperatures\t using\tthe\tapparatus\t shown\tin\tthe\tdiagram.\t all other conditions were kept the same. dilute hydrochloric acid calcium carbonategas syringe   experiment 1  \u25cf using a 50 cm3 measuring cylinder, 25 cm3 of dilute hydrochloric acid was poured into a boiling  tube.  \u25cf the temperature of the dilute hydrochloric acid was measured using a thermometer.  \u25cf 10 g of lumps of calcium carbonate were added to the boiling tube, the bung replaced and the  stop\u2011watch started.  \u25cf the volume of gas collected in the gas syringe was measured every 50 seconds for 250 seconds.   experiment 2  \u25cf using a 50 cm3 measuring cylinder, 25 cm3 of dilute hydrochloric acid was poured into a boiling  tube.  \u25cf the dilute hydrochloric acid in the boiling tube was warmed using a bunsen burner.  \u25cf the temperature of the dilute hydrochloric acid was measured using a thermometer.  \u25cf 10 g of lumps of calcium carbonate were added to the boiling tube, the bung replaced and the  stop\u2011watch started.  \u25cf the volume of gas collected in the gas syringe was measured every 50 seconds for 250 seconds.",
            "5": "5 0620/61/o/n/21 \u00a9 ucles 2021 [turn over  (a)  use the diagrams to complete the tables for experiment 1. thermometer diagramtemperature of dilute hydrochloric acid / \u00b0c 30 25 20 time / s gas syringe diagramvolume of gas collected / cm3 0 10 20 30 40 50 50 10 20 30 40 50 100 10 20 30 40 50 150 10 20 30 40 50 200 10 20 30 40 50 250 10 20 30 40 50  [2]",
            "6": "6 0620/61/o/n/21 \u00a9 ucles 2021  (b)  use the diagrams to complete the tables for experiment 2. thermometer diagramtemperature of dilute hydrochloric acid / \u00b0c 45 40 35 time / s gas syringe diagramvolume of gas collected / cm3 0 10 20 30 40 50 50 10 20 30 40 50 100 10 20 30 40 50 150 10 20 30 40 50 200 10 20 30 40 50 250 10 20 30 40 50  [2]",
            "7": "7 0620/61/o/n/21 \u00a9 ucles 2021 [turn over  (c)  plot the results from experiment 1 and experiment 2 on the grid. \t \tdraw\ta\tcurve\tof\tbest\tfit\tfor\teach\texperiment.\tlabel\tyour\tcurves. 0 50volume of gas collected  / cm3 100 150 time  / s200 250 30050 40 30 20 10 0  [5]  (d)  from your graph , deduce the volume of gas collected in experiment 2 after 120 seconds.   show clearly on the grid  how you worked out your answer.  .. cm3  [2]  (e)  explain how the results show that the reaction in experiment 2 has stopped.      ..   [1]  (f)  predict the volume of gas that would be collected in experiment 1 after 800 seconds.   explain your answer.  volume of gas collected after 800 seconds    cm3  explanation       [2]",
            "8": "8 0620/61/o/n/21 \u00a9 ucles 2021  (g)  a student stated it would be an improvement to measure the volume of gas collected every  25 seconds.   explain why this is an improvement.         ..   [2]  (h)  state two changes to the apparatus to improve the accuracy of the results obtained if the  experiment is repeated using the same thermometer.  change 1       change 2       [2]  (i)  describe how the method used in experiment 2 could be changed so that results can be  obtained using dilute hydrochloric acid at 1 \u00b0c.      ..   [1]  [total: 19]",
            "9": "9 0620/61/o/n/21 \u00a9 ucles 2021 [turn over 3  solution y and solution z were analysed.   the following tests were done on the solutions.  tests on solution y tests observations solution y was divided into four portions in four  test\u2011tubes. test 1 a strip of universal indicator paper was dipped  into\tthe\tfirst\tportion\tof\tsolution\t y.the universal indicator paper turned blue test 2 aqueous copper( ii) sulfate was added to the  second portion of solution y.a blue precipitate formed test 3 a\tflame\ttest\twas\tdone\tusing\tthe\tthird\tportion\tof\t solution y.a\tred\tflame\twas\tseen test 4 2 cm3 of dilute sulfuric acid was added to the  fourth portion of solution y.no visible change; the test\u2011tube became slightly warmer  (a)  suggest the ph of solution y.   ..   [1]  (b)  identify solution y.      ..   [2]",
            "10": "10 0620/61/o/n/21 \u00a9 ucles 2021  tests on solution z   solution z\twas\taqueous\tammonium\tsulfite.   complete all of the expected observations.   solution z was divided into three portions in two boiling tubes and a test\u2011tube.  (c)  5 cm3\tof\tdilute\thydrochloric\t acid\twas\tadded\tto\tthe\tfirst\tportion\tof\tsolution\t z in a boiling  tube.\tthe\tmixture\t was\twarmed\t and\ta\tpiece\tof\tfilter\tpaper\tsoaked\tin\tacidified\t aqueous\t potassium manganate( vii) held at the mouth of the boiling tube. \t \tstate\tthe\tcolour\tchange\tof\tthe\tacidified\taqueous\tpotassium\tmanganate( vii).  from  to     [2]  (d)  name the gas being tested for in (c).   ..   [1]  (e)  5 cm3 of aqueous sodium hydroxide was added to the second portion of solution z in a boiling  tube.\tthe\tmixture\twas\twarmed\tand\tthe\tgas\tgiven\toff\twas\ttested.  result of gas test     ..   [1]  (f)\t\tidentify\tthe\tgas\tgiven\toff\tin\t (e).   ..   [1]  (g)  about 1 cm3 of dilute hydrochloric acid followed by a few drops of aqueous barium nitrate were  added to the third portion of solution z.  observations     [1]  [total: 9]",
            "11": "11 0620/61/o/n/21 \u00a9 ucles 2021 [turn over 4  tartrazine is used as a yellow food colouring. \t\tplan\tan\tinvestigation\t to\tfind\tout\tif\ta\tyellow\tsweet\tcontains\t tartrazine.\t explain\thow\tyour\tresults\twill\t tell you if the sweet contains tartrazine.   you have access to all normal laboratory materials, a yellow sweet and a sample of tartrazine.   you may draw a labelled diagram as part of your answer.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "12": "12 0620/61/o/n/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w21_qp_62.pdf": {
            "1": "*8853844180* chemistry  0620/62 paper 6 alternative to practical october/november 2021  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib21 11_0620_62/2rp \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/62/o/n/21 \u00a9 ucles 2021 1  carbon dioxide is a colourless gas that is denser than air.   carbon dioxide can be made by reacting marble chips with dilute hydrochloric acid.   a student tried to make and collect carbon dioxide gas using the apparatus shown. a c bgas ja r  (a) (i)  name the substances labelled a and b.  a  .  b  .  [1]  (ii)  name the item of apparatus labelled c.   ...   [1]  (b)  explain why very little carbon dioxide gas would be collected using the apparatus shown.      ..   [2]",
            "3": "3 0620/62/o/n/21 \u00a9 ucles 2021 [turn over  (c)  complete the diagram to show how carbon  dioxide gas could be collected and the volume  measured.  [2]  (d)  at the end of the experiment there were unreacted marble chips and aqueous calcium chloride  in the item of apparatus labelled c. \t \tdescribe\thow\tyou\twould\tfind\tthe\tmass\tof\tunreacted\tmarble\tchips\tin\tapparatus\t c.            ..   [3]  [total: 9]",
            "4": "4 0620/62/o/n/21 \u00a9 ucles 2021 2\t\ta\tstudent\tinvestigated \tthe\treaction\t between\t two\tdifferent\t solutions\t of\taqueous\t sodium\tcarbonate,\t solution k and solution l,\t and\ttwo\tdifferent\t solutions \tof\tdilute\thydrochloric\t acid,\tacid\t m and acid n.   three experiments were done.  (a) experiment 1  \u25cf a burette was filled with solution k. some of solution  k was run out of the burette so that  the level of solution k was on the burette scale.  \u25cf using a measuring cylinder 25 cm3 of acid m was poured into a conical flask.  \u25cf five drops of methyl orange indicator were added to the conical flask.  \u25cf the conical flask was placed on a white tile.  \u25cf solution k\twas\tadded\tslowly\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tthe\tflask\twas\t swirled,\tuntil\tthe\tsolution\tjust\tchanged\tcolour.   use the burette diagrams to complete the table for experiment 1. 7 8 9 initial reading31 32 33 final reading experiment 1 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of solution k\tadded\t /\tcm3   experiment 2  \u25cf the conical flask was emptied and rinsed with distilled water.  \u25cf the burette was refilled with solution k. some of solution k was run out of the burette so  that the level of solution k was on the burette scale.  \u25cf using a measuring cylinder 25 cm3 of acid n was poured into the conical flask.  \u25cf five drops of methyl orange indicator were added to the conical flask.  \u25cf the conical flask was placed on a white tile.  \u25cf solution k\twas\tadded\tslowly\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tthe\tflask\twas\t swirled,\tuntil\tthe\tsolution\tjust\tchanged\tcolour.",
            "5": "5 0620/62/o/n/21 \u00a9 ucles 2021 [turn over   use the burette diagrams to complete the table for experiment 2. 3 4 5 initial reading15 16 17 final reading experiment 2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of solution k\tadded\t /\tcm3   experiment 3  \u25cf the burette was emptied and rinsed with distilled water.  \u25cf the conical flask was emptied and rinsed with distilled water.  \u25cf the burette was filled with solution l. some of solution l was run out of the burette so that  the level of solution l was on the burette scale.  \u25cf using a measuring cylinder 25 cm3 of acid n was poured into the conical flask.  \u25cf five drops of methyl orange indicator were added to the conical flask.  \u25cf the conical flask was placed on a white tile.  \u25cf solution l\twas\tadded\tslowly\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tthe\tflask\twas\t swirled,\tuntil\tthe\tsolution\tjust\tchanged\tcolour.   use the burette diagrams to complete the table for experiment 3. 2 3 4 initial reading26 27 28 final reading experiment 3 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of solution l\tadded\t /\tcm3  [5]",
            "6": "6 0620/62/o/n/21 \u00a9 ucles 2021  (b)\t\tstate\tthe\tcolour\tchange\tobserved\tat\tthe\tend-point\tin\tthe\tconical\tflask\tin\texperiment\t1.  from  to     [1]  (c)  describe one other observation made when solution k was added to acid m in experiment 1.   ..   [1]  (d) (i)  compare the volumes of solution k used in experiment 1 and experiment 2.   .   ...   [2]  (ii)\t\tsuggest\t why\tdifferent\tvolumes\t of\tsolution\t k were needed in experiment 1 and experiment 2.   ...   [1]  (e)  deduce the volume of solution l required to reach the end-point if experiment 3 is repeated  using acid m in place of acid n.  volume of solution l = .. cm3  [1]  (f)\t\texplain\twhy\tthe\tconical\tflask\twas\trinsed\twith\twater\tat\tthe\tstart\tof\texperiment\t 2\tand\texperiment\t 3.   ..   [1]  (g)  at the start of experiment 3 the burette was rinsed with water.   describe an additional step that should have been done after rinsing the burette with water but  before\tfilling\tthe\tburette\twith\tsolution\t l. explain your answer.      ..   [2]  (h)\t\texplain\twhy\tthe\tconical\tflask\tis\tplaced\ton\ta\twhite\ttile.   ..   [1]  (i)\t\tdescribe\thow\tthe\treliability\tof\tthe\tresults\tcan\tbe\tconfirmed.      ..   [1]",
            "7": "7 0620/62/o/n/21 \u00a9 ucles 2021 [turn over  (j)  state one source of error in experiment 1. suggest an improvement to reduce this error.  source of error  ...  improvement  ..  [2]  [total: 18]",
            "8": "8 0620/62/o/n/21 \u00a9 ucles 2021 3  solid o and liquid p were analysed. solid o was ammonium bromide.   tests were done on each substance.  tests on solid o   complete the expected observations.   solid o was dissolved in water to form solution o. solution o was divided into four approximately  equal portions in four test-tubes.  (a)\t\tto\tthe\tfirst\tportion\tof\tsolution\to,\tapproximately\t2\t cm3 of aqueous ammonia was added.  observations     [1]  (b)  to the second portion of solution o,\t approximately\t 2\tcm3 of aqueous sodium hydroxide was  added.\tthe\tmixture\tformed\twas\twarmed.\t a\tgas\twas\tgiven\toff.  (i)\t\tthe\tgas\tgiven\toff\twas\ttested\twith\tdamp \tred\tlitmus\tpaper.  observations  .   [1]  (ii)\t\tidentify\tthe\tgas\tgiven\toff.   ...   [1]  (c)  to the third portion of solution o,\tapproximately\t 1\tcm3 of dilute nitric acid followed by a few  drops of aqueous silver nitrate were added.  observations     [1]  (d)  to the fourth portion of solution o,\tapproximately\t1\t cm3 of aqueous chlorine was added.  observations     [1]",
            "9": "9 0620/62/o/n/21 \u00a9 ucles 2021 [turn over  tests on liquid p tests observations test 1 a few drops of liquid p were placed in a  crucible. a lighted splint was applied to the  surface of liquid p in the crucible.burned\twith\tan\torange\tflame\tand\tlots\tof\tsmoke;\t soot was left around the top of the crucible test 2 a few drops of liquid p were added to a  test-tube containing 1 cm3 of aqueous  bromine.colour changed from orange to colourless  (e)  state what conclusions can be made about liquid p.      ..   [2]  [total: 7]",
            "10": "10 0620/62/o/n/21 \u00a9 ucles 2021 4  cobalt is a metal. cobalt is between copper and iron in the reactivity series. the mineral   spherocobaltite contains the compound cobalt( ii) carbonate and no other metal ions.  cobalt( ii) carbonate is insoluble in water and reacts with dilute acids to form an aqueous solution  of a salt.   describe how you would obtain a sample of cobalt metal starting with a large lump of spherocobaltite.  you have access to all normal laboratory apparatus and chemicals.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "11": "11 0620/62/o/n/21 \u00a9 ucles 2021blank page",
            "12": "12 0620/62/o/n/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "0620_w21_qp_63.pdf": {
            "1": "*4026350879* chemistry  0620/63 paper 6 alternative to practical october/november 2021  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib21 11_0620_63/3rp r \u00a9 ucles 2021 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/63/o/n/21 \u00a9 ucles 2021blank page",
            "3": "3 0620/63/o/n/21 \u00a9 ucles 2021 [turn over 1  hot concentrated hydrochloric acid reacts with solid manganese( iv) oxide to make chlorine gas.   chlorine gas can be dried by bubbling it through a liquid drying agent.   the diagram shows the apparatus used to make and collect a sample of dry chlorine gas. there is  one error in the diagram. zxy liquid drying agent  (a)  name the items of apparatus labelled x and y.  x    y    [2]  (b)  name the substance labelled z.   ..   [1]  (c)  on the diagram draw one arrow to show where heat should be applied so that chlorine gas is  made. [1]  (d)  there is one error in the way the apparatus has been set up.  (i)  on the diagram  draw a circle around the error in the apparatus. [1]  (ii)  describe what would happen if the apparatus is used before the error is corrected.   .   ...   [1]  [total: 6]",
            "4": "4 0620/63/o/n/21 \u00a9 ucles 2021 2\t\ta\tstudent\tinvestigated \tthe\ttemperature\t change\twhen\tzinc\treacted\t with\ttwo\tdifferent\t aqueous\t solutions of copper( ii) sulfate, solution q and solution r.   two experiments were done.  (a)  experiment 1  \u25cf a polystyrene cup was placed in a 250 cm3 beaker for support.  \u25cf using a measuring cylinder, 25 cm3 of solution q was poured into the polystyrene cup.  \u25cf using a thermometer, the initial temperature of solution q was measured.  \u25cf 3 g of zinc powder was added to the polystyrene cup. at the same time a stop\u2011clock was  started.  \u25cf using the thermometer, the mixture in the polystyrene cup was continually stirred and the  temperature measured every 30 seconds. initial temperature in experiment 1 23 \u00b0c   use the thermometer diagrams and the initial temperature to complete the table.   calculate the temperature changes using the equation: temperature change = temperature \u2013 initial temperature 45 40 3555 50 4555 50 4555 50 4555 50 4555 50 4555 50 45time  / s3 0 thermometer diagram temperature  / /g113c temperature change  / /g113c50 45 4060 90 120 150 180 210 240  [3]",
            "5": "5 0620/63/o/n/21 \u00a9 ucles 2021 [turn over  (b) experiment 2  \u25cf the polystyrene cup was washed out with distilled water.  \u25cf experiment 1 was repeated using solution r instead of solution q. initial temperature in experiment 2 24 \u00b0c   use the thermometer diagrams and the initial temperature to complete the table. 35 30 2545 40 3545 40 3545 40 3545 40 35time  / s3 0 thermometer diagram temperature  / /g113c temperature change  / /g113c40 35 3040 35 3040 35 3060 90 120 150 180 210 240  [3]  (c)  complete a suitable scale on the y\u2011axis and plot the results from experiment 1 and experiment 2  on\tthe\tgrid.\tdraw\ttwo\tcurves\tof\tbest\tfit.\tboth\tcurves\tmust\tstart\tat\t(0,0).\tlabel\tyour\tcurves. 00 50temperature change  / /g113c 100 150 time  / s200 250  [5]",
            "6": "6 0620/63/o/n/21 \u00a9 ucles 2021  (d)  from your graph , deduce the temperature change at 110 seconds in experiment 1.   show clearly on the grid  how you worked out your answer.  .. \u00b0c  [2]  (e)  predict the temperature of the solution in experiment 2 after 5 hours. explain your answer.      ..   [2]  (f) (i)  suggest why the experiments were done in a polystyrene cup rather than a glass beaker.   ...   [1]  (ii)\t\tdescribe\t how\tthe\tresults\twould\tbe\tdifferent\t if\ta\tglass\tbeaker\tis\tused\tin\tplace\tof\tthe\t polystyrene cup.   ...   [1]  (g)  suggest one change that could be made to the apparatus that would improve the accuracy of  the results. explain why this change would improve the accuracy of the results.  change  ...  explanation       [2]  [total: 19]",
            "7": "7 0620/63/o/n/21 \u00a9 ucles 2021 [turn over 3  solid s and solid t were analysed.   tests were done on each substance.   tests on solid s tests observations test 1 solid s was placed in a boiling tube and 10 cm3  of dilute hydrochloric acid was added.effervescence the solution formed in test 1 was decanted  from the remaining solid s. the solution is  solution u. test 2 aqueous sodium hydroxide was added  dropwise and then in excess to solution u.white precipitate, insoluble in excess \t\tthe\tgas\tgiven\toff\tin\t test 1 was carbon dioxide.  (a)  describe how the gas produced in test 1 could be tested to show that it was carbon dioxide.  give the expected result of the test.  test  .  result  ..  [2]  (b)  identify solid s.      ..   [2]",
            "8": "8 0620/63/o/n/21 \u00a9 ucles 2021  tests on solid t   solid t was iron( iii) chloride.   solid t was dissolved in water to form solution t. solution t was divided into four equal portions in  four test\u2011tubes.  (c)\t\tto\tthe\tfirst\tportion\tof\tsolution\t t, aqueous sodium hydroxide was added dropwise and then in  excess.  observations  ..   ..   [2]  (d)  to the second portion of solution t, 2 cm3 of aqueous ammonia was added.  observations     [1]  (e)  to the third portion of solution t, 1 cm3 of dilute nitric acid followed by a few drops of aqueous  silver nitrate were added.  observations     [1]  (f)  to the fourth portion of solution t, 1 cm3 of dilute nitric acid followed by a few drops of aqueous  barium nitrate were added.  observations     [1]  [total: 9]",
            "9": "9 0620/63/o/n/21 \u00a9 ucles 2021 [turn over 4  catalysts are substances which increase the rate of a reaction but are unchanged at the end of the  reaction.   aqueous hydrogen peroxide decomposes slowly to form water and oxygen. 2h2o2(aq)  \u2192  2h2o(l)  +  o2(g)   copper( ii) oxide is an insoluble solid. \t\tplan\tan\tinvestigation\t to\tfind\tout\tif\tcopper( ii) oxide is a catalyst for the decomposition of  hydrogen peroxide. you must include how your results will tell you if copper( ii) oxide is a catalyst.  you have access to copper( ii) oxide, aqueous hydrogen peroxide and all normal laboratory  apparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "10": "10 0620/63/o/n/21 \u00a9 ucles 2021blank page",
            "11": "11 0620/63/o/n/21 \u00a9 ucles 2021blank page",
            "12": "12 0620/63/o/n/21 \u00a9 ucles 2021blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of the cambridge assessment group. cambridge assessment is the brand name of the university of  cambridge local examinations syndicate (ucles), which itself is a department of the university of cambridge."
        },
        "1523_j21_qp_12.pdf": {
            "1": "    this document has 16 pages.  ib21 06_1523_12/fp   \u00a9 ucles 2021  [turn ove r   *1301718764 *cambridge igcse\u2122       chemistry 1523/12     paper 1 multiple choice (core)  may/june 2021     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)      instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be done on this question paper.  \uf0b7 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 1523/12/m/j/21  1 which processes are involved when steam changes into ice?  a boiling and freezing  b boiling and melting  c condensing and freezing  d condensing and melting     2 a student uses the apparatus shown to measure the volume of ca rbon dioxide gas made when  different masses of marble chips are added to 25  cm3 of dilute hydrochloric acid.    marble chipsbunggas syringe 25 cm3 dilute hydrochloric acid     which other items of apparatus are needed?  a funnel and balance  b funnel and stop-watch  c measuring cylinder and balance  d measuring cylinder and stop-watch    ",
            "3": "3     \u00a9 ucles 2021 1523/12/m/j/21 [turn over  3 a solute and a solvent are separated by distillation.    which diagram is correctly labelled?    solute heata water out water in solute solvent solventheatb water in water out heatc water out water in solute heatd water in water out solutesolvent solvent       4 a magnesium atom has the symbol 24 12mg. it reacts to form a magnesium ion, mg2+.    which row identifies the number of protons, neutrons and electr ons in the ion?     protons neutrons electrons  a 10 10 10  b 10 12 12  c 12 12 10  d 12 12 12     ",
            "4": "4  \u00a9 ucles 2021 1523/12/m/j/21  5 hexadecane is an alkane.    the melting and boiling points of pure hexadecane are shown.    melting point = 18  \uf0b0c  boiling point = 287  \uf0b0c    which row shows melting and boiling points of an impure sample of hexadecane?     melting point  / \uf0b0c boiling point  / \uf0b0c  a 14\u201316 282\u2013284  b 14\u201316 290\u2013292  c 20\u201322 282\u2013284  d 20\u201322 290\u2013292     6 which substance is a compound?  a air  b methane  c nitrogen  d steel     7 which row describes the properties of diamond?     soluble  in water electrical  conductivity  a yes none  b yes good  c no none  d no good     ",
            "5": "5     \u00a9 ucles 2021 1523/12/m/j/21 [turn over  8 the electronic structure of a calcium atom is shown.    ca     what is the electronic structure of a calcium ion?  a 2,8,8 b 2,8,8,2 c 2,8,8,4 d 2,8,8,8      9 the equation for the complete combustion of ethanethiol, c 2h6s, is shown.    2c2h6s  +  9o 2  \uf0ae    +  2so 2  +  6h 2o    which formula balances the equation?  a 2 c o 2 b 4 c o 2 c 2 c o  d 4 c o      10 calcium phosphate has the formula ca 3(po 4)2.    what is the relative formula mass of calcium phosphate?  a 135 b 215 c 230 d 310     ",
            "6": "6  \u00a9 ucles 2021 1523/12/m/j/21  11 the apparatus used to electroplate an object with silver is sho wn.    power supply +\u2013electrode x object beingelectroplated electrolyte     which row identifies electrode x and a suitable electrolyte?     element from which  electrode x is made name of electrolyte  a carbon aqueous silver nitrate  b carbon dilute hydrochloric acid  c silver aqueous silver nitrate  d silver dilute hydrochloric acid     12 an energy level diagram for a reaction is shown.    energy progress of reaction    which statement and explanation about this reaction are correct ?     statement explanation  a the reaction is endothermic the products have more energy than the reactants  b the reaction is endothermic the products have less energy than the reactants  c the reaction is exothermic the products have more energy than t he reactants  d the reaction is exothermic the products have less energy than t he reactants     ",
            "7": "7     \u00a9 ucles 2021 1523/12/m/j/21 [turn over  13 molten sodium chloride is broken down by electrolysis.    which row identifies the product at each electrode?     anode cathode  a chlorine hydrogen  b chlorine sodium  c hydrogen chlorine  d sodium chlorine      14 which processes are physical changes?    1 melting ice  2 reduction of copper( ii) oxide  3 burning sulfur  4 boiling ethanol    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     15 which fuel does not produce carbon dioxide when it burns?  a coal  b hydrogen  c methane  d petrol    ",
            "8": "8  \u00a9 ucles 2021 1523/12/m/j/21  16 an excess of calcium carbonate is reacted with acid in experime nts 1 and 2.    the volume of gas produced is measured over time. the results a re plotted on the graph.    time  / svolume of gas  / cm3 0 0experiment 1 experiment 2     which statement explains the observed results?  a the concentration of acid is higher in experiment 1.  b the mass of calcium carbonate is higher in experiment 1.  c the temperature of the acid is lower in experiment 1.  d smaller pieces of calcium carbonate are used in experiment 1.     17 which row describes the effect of adding water to blue cobalt( ii) chloride and to blue  copper( ii) sulfate?     effect of adding  water to blue  cobalt( ii) chloride effect of adding  water to blue  copper( ii) sulfate   a \u001a \u001a k e y   b \u001a \u0016 \u0016 = colour change  c \u0016 \u001a \u001a = no colour change  d \u0016 \u0016      18 the reaction between magnesium and carbon dioxide is shown.    2mg  +  co 2  \uf0ae  2mgo  +  c    which statement describes what happens in this reaction?  a carbon is oxidised.  b magnesium is reduced.  c neither oxidation nor reduction happens.  d the carbon in carbon dioxide is reduced.     ",
            "9": "9     \u00a9 ucles 2021 1523/12/m/j/21 [turn over  19 which statements about alkaline solutions are correct?    1 when reacted with an acid, the ph of the alkali increases.  2 when tested with litmus, the litmus turns blue.  3 when warmed with an ammonium salt, ammonia gas is given off.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2 and 3 only     20 nickel( ii) sulfate is made by reacting insoluble nickel( ii) carbonate with dilute sulfuric acid.    the method used is shown.    step 1 add excess nickel( ii) carbonate to dilute sulfuric acid.  step 2 filter the mixture and collect the filtrate.  step 3 heat the filtrate in an e vaporating basin until crystals  start to form.  step 4 leave the solution formed to cool.    which substances are removed from the mixture in step 2 and in step 3?     step 2 step 3  a nickel( ii) carbonate sulfuric acid  b nickel( ii) carbonate water  c nickel( ii) sulfate sulfuric acid  d nickel( ii) sulfate water     21 compound x is tested and the results are shown.    test result  aqueous sodium hydroxide is  added, then heated gently gas given off which turns damp  red litmus paper blue  dilute hydrochloric acid is added effervescence, gas given off  which turns limewater milky    which ions are present in compound x?  a ammonium ions and carbonate ions  b ammonium ions and chloride ions  c calcium ions and carbonate ions  d calcium ions and chloride ions    ",
            "10": "10  \u00a9 ucles 2021 1523/12/m/j/21  22 which statement about elements in the periodic table is correc t?  a elements are arranged in order of increasing nucleon number.  b elements in group vii are diatomic non-metals.  c elements with similar properties are in the same period.  d transition elements are a collection of metals and non-metals.      23 which statement explains why the noble gas helium is unreactiv e?  a it has a complete outer shell of electrons.  b it has two protons in the nucleus.  c it has the same number of protons and neutrons.  d it has the same number of protons, electrons and neutrons.     24 which row describes a typical transition element?     density colour of oxide  a high green  b high white  c low green  d low white      25 the element rutherfordium, rf, was first detected in 1964.    rutherfordium is a metal.    what are the predicted properties of rutherfordium?    1 rutherfordium conducts electricity when molten.  2 rutherfordium does not conduct electricity when solid. 3 rutherfordium has a low melting point.  4 rutherfordium is malleable.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     ",
            "11": "11     \u00a9 ucles 2021 1523/12/m/j/21 [turn over  26 the reactions of four metals are described.    cu has no reaction with water, steam or warm dilute hydrochlori c acid.    li reacts with cold water.    mg reacts very slowly with water, and reacts with both steam an d cold dilute hydrochloric acid.    sn reacts slowly with warm dilute hydrochloric acid.    what is the order of reactivity of the metals?     most  reactive  least  reactive  a li mg sn cu  b li sn mg cu  c cu sn mg li  d cu mg sn li      27 a farmer moves his cows into a concrete shelter for protection .    there is little access to fresh air once the door is closed.    which gases would increase in amount in the shelter?  a carbon dioxide and carbon monoxide  b carbon dioxide and methane  c carbon monoxide and oxygen  d methane and oxygen     28 iron is extracted from its ore in a blast furnace.    the equations for four different reactions are shown.    1 4fe  +  3co 2  \uf0ae  2fe 2o3  +  3c  2 co 2  \uf0ae  c  +  o 2  3 co 2  +  c  \uf0ae  2co  4 fe 2o3  +  3co  \uf0ae  2fe  +  3co 2    which equations represent reactions that occur in the blast fur nace?  a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4     ",
            "12": "12  \u00a9 ucles 2021 1523/12/m/j/21  29 which row about aluminium is correct?     name of ore properties of aluminium  a bauxite resistant to corrosion and low density  b bauxite good electrical conductor and high density  c hematite resistant to corrosion and low density  d hematite good electrical conductor and high density      30 which substances are needed for iron to rust?  a carbon dioxide and oxygen  b oxygen only  c water and carbon dioxide  d water and oxygen     31 which three elements are needed in fertilisers?  a calcium, nitrogen and phosphorus  b carbon, potassium and nitrogen  c potassium, nitrogen and phosphorus  d potassium, phosphorus and carbon     32 which statements describe uses for calcium oxide?    1 flue gas desulfurisation  2 treating alkaline soil  3 reducing iron oxide in the blast furnace    a 1 only b 1 and 2 c 1 and 3 d 2 only     33 what are uses of sulfur dioxide?    1 as a bleach in the manufacture of wood pulp  2 as a food preservative 3 in the conversion of iron to steel  4 to kill bacteria in water treatment    a 1 and 2 b 1 and 3 c 2 and 3 d 2 and 4    ",
            "13": "13     \u00a9 ucles 2021 1523/12/m/j/21 [turn over  34 which type of reaction occurs when calcium oxide is formed fro m calcium carbonate?  a addition  b combustion  c neutralisation  d thermal decomposition     35 the structures of some organic compounds are shown.    1 hch hch ho h2 hch hch hhh c h hch hch hhh c o h3 4 o ohch hch hc h    which compounds belong to the same homologous series?  a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4     ",
            "14": "14  \u00a9 ucles 2021 1523/12/m/j/21  36 the industrial fractional distillation of petroleum is shown.    kerosene fractionnaphtha fractiongasoline fractionrefinery gas diesel oil fuel oil fraction petroleum lubricating fraction and bitumeny     which process happens at y?  a burning  b condensation  c c r a c k i n g   d evaporation     37 which description of the bonding in alkanes is correct?  a covalent bonding, all bonds are double bonds  b covalent bonding, all bonds are single bonds  c covalent bonding, with both single and double bonds  d ionic bonding     38 which process converts glucose into ethanol?  a catalytic addition of steam  b c r a c k i n g   c fermentation  d thermal decomposition    ",
            "15": "15         permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international education copyright acknowledgements b ooklet. this is produced for each series of examinations and is  freely available to download  at www.cambridgeinternational.org after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambridge assessment is the brand name  of the university of  cambridge local examinations syndicate (ucles), which itself is  a department of the university of cambridge.    \u00a9 ucles 2021 1523/12/m/j/21  39 which word equation represents a reaction of aqueous ethanoic a cid?  a ethanoic acid  +  copper  \uf0ae  copper ethanoate  +  hydrogen  b ethanoic acid  +  magnesium  \uf0ae  magnesium ethanoate  +  water  c ethanoic acid  +  sodium oxide  \uf0ae  sodium ethanoate  +  hydrogen  d ethanoic acid  +  calcium oxide  \uf0ae  calcium ethanoate  +  water     40 which statement describes a polymer?  a it is a covalent molecule obtained by fractional distillation.  b it is a large covalent molecule obtained by cracking.  c it is a large molecule made from joining many monomer molecules toget her.  d it is a small molecule formed by splitting up a larger molecule .    ",
            "16": "16  \u00a9 ucles 2021 1523/12/m/j/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "1523_j21_qp_22.pdf": {
            "1": "    this document has 16 pages.  ib21 06_1523_22/fp   \u00a9 ucles 2021  [turn ove r   *3108262204 *cambridge igcse\u2122       chemistry 1523/22     paper 2 multiple choice (extended)  may/june 2021     45 minutes    you must answer on the multiple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)      instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there are four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be done on this question paper.  \uf0b7 the periodic table is printed in the question paper.   ",
            "2": "2  \u00a9 ucles 2021 1523/22/m/j/21  1 gaseous ammonia and gaseous hydrogen chloride react to form amm onium chloride, a white  solid.    cotton wool soaked in concentrated aqueous ammonia is placed in  one end of a glass tube and  at the same time cotton wool soaked in concentrated hydrochlori c acid is placed at the other end  of the tube. the tube is sealed.    where in the tube does the white solid initially appear?    concentrated aqueous ammoniaconcentrated hydrochloric acida white solidconcentrated aqueous ammoniaconcentrated hydrochloric acidb white solid concentrated aqueous ammoniaconcentrated hydrochloric acidc white solidconcentrated aqueous ammoniaconcentrated hydrochloric acidd white solid     2 a student uses the apparatus shown to measure the volume of ca rbon dioxide gas made when  different masses of marble chips are added to 25  cm3 of dilute hydrochloric acid.    marble chipsbunggas syringe 25 cm3 dilute hydrochloric acid     which other items of apparatus are needed?  a funnel and balance  b funnel and stop-watch  c measuring cylinder and balance  d measuring cylinder and stop-watch ",
            "3": "3     \u00a9 ucles 2021 1523/22/m/j/21 [turn over  3 a solute and a solvent are separated by distillation.    which diagram is correctly labelled?    solute heata water out water in solute solvent solventheatb water in water out heatc water out water in solute heatd water in water out solutesolvent solvent       4 a magnesium atom has the symbol 24 12mg. it reacts to form a magnesium ion, mg2+.    which row identifies the number of protons, neutrons and electr ons in the ion?     protons neutrons electrons  a 10 10 10  b 10 12 12  c 12 12 10  d 12 12 12     ",
            "4": "4  \u00a9 ucles 2021 1523/22/m/j/21  5 which dot-and-cross diagram shows the outer-shell electron arr angement in a molecule of  carbon dioxide?    ca oo o cb oo cc ocd oo       6 the electronic structures of atoms x and y are shown.    x ykey electron     what is the formula of the molecule formed by x and y?  a xy 2 b x3y2 c x2y3 d x2y     7 which row about a property of silicon( iv) oxide and the explanation of the property is correct?     property of silicon( iv) oxide explanation  a   it conducts electricity   electrons can move freely  through the structure  b   it is used as a lubricant   there are weak forces between the  layers of silicon and oxygen atoms  c   it has a high melting point   there is a strong attraction  between silicon and oxide ions  d   it is a hard solid   it is a macromolecule  with strong bonds    ",
            "5": "5     \u00a9 ucles 2021 1523/22/m/j/21 [turn over  8 these two statements are about metals, their properties and bon ding.    statement 1 metals conduct electricity when solid.  statement 2 in metals, a lattice of positive ions exists in a \u2018 sea of electrons\u2019 which can  move throughout the metal.    which answer is correct?  a both statements are correct and statement 2 explains statement  1.  b both statements are correct but statement 2 does not explain s tatement 1.  c statement 1 is correct but statement 2 is incorrect.  d statement 2 is correct but statement 1 is incorrect.     9 the equation for the complete combustion of ethanethiol, c 2h6s, is shown.    2c2h6s  +  9o 2  \uf0ae    +  2so 2  +  6h 2o    which formula balances the equation?  a 2 c o 2 b 4 c o 2 c 2 c o  d 4 c o       10 the equation for the formation of ethanol from glucose is show n.    c6h12o6  \uf0ae  2c 2h5oh  +  2co 2    in an experiment, 36  g of glucose produces 9.2  g of ethanol.    [mr:  c 6h12o6, 180;  c 2h5oh, 46]    what is the percentage yield of ethanol in this experiment?  a 20 b 26 c 50 d 100     ",
            "6": "6  \u00a9 ucles 2021 1523/22/m/j/21  11 four electrolysis experiments are described.    electrolyte electrodes  aqueous copper( ii) sulfate copper  aqueous copper( ii) sulfate graphite  concentrated aqueous sodium chloride graphite  dilute sulfuric acid graphite    which statement is correct for all four electrolysis experiments?  a hydrogen gas is formed at the cathode.  b ions gain electrons at the cathode.  c the electrodes are inert.  d two or more products are formed.     12 an energy level diagram for a reaction is shown.    energy progress of reaction    which statement and explanation about this reaction are correct ?     statement explanation  a the reaction is endothermic the products have more energy than the reactants  b the reaction is endothermic the products have less energy than the reactants  c the reaction is exothermic the products have more energy than t he reactants  d the reaction is exothermic the products have less energy than t he reactants     13 which product is made in a fuel cell?  a carbon dioxide  b ethanol  c h y d r o g e n   d water    ",
            "7": "7     \u00a9 ucles 2021 1523/22/m/j/21 [turn over  14 which processes are physical changes?    1 melting ice  2 reduction of copper( ii) oxide  3 burning sulfur  4 boiling ethanol    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     15 a chemical reaction is carried out at a fixed temperature.    it is repeated at a higher concentration. all other conditions remain the same.    which row describes how the collision rate and the proportion o f molecules with the activation  energy changes in the second reaction?     collision rate proportion of molecules with the  activation energy  a increases increases  b increases no change  c no change increases  d no change no change      16 the equation for the reaction between aqueous potassium iodide  and aqueous bromine is shown.    2ki(aq)  +  br 2(aq)  \uf0ae  2kbr(aq)  +  i2(s)    which statement about the reaction is correct?  a bromine is reduced.  b the potassium ions act as an oxidising agent.  c the potassium ions are oxidised.  d the iodide ions gain electrons.    ",
            "8": "8  \u00a9 ucles 2021 1523/22/m/j/21  17 hydrogen and iodine gases react together to produce gaseous hy drogen iodide in a reversible  reaction.    h2(g)  +  i2(g)    2h i(g)    the forward reaction is exothermic.    hydrogen and hydrogen iodide are colourless gases. iodine gas i s purple.    which statement is correct?  a the forward and reverse reactions both stop when equilibrium i s reached.  b the position of equilibrium is not affected by pressure change s.  c the position of equilibrium is not affected by temperature cha nges.  d the reaction mixture continues to change colour after equilibr ium is reached.     18 ethanoic acid is a weak acid.    hydrochloric acid is a strong acid.    which statements are correct?    1 ethanoic acid molecules are partially dissociated in aqueous solution.  2 1.0  mol  / dm3 ethanoic acid has a higher ph than 1.0  mol  / dm3 hydrochloric acid.  3 ethanoic acid is always more dilute than hydrochloric acid.  4 ethanoic acid is a proton acceptor.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     19 which oxide neutralises aqueous sodium hydroxide?  a calcium oxide  b carbon monoxide  c sulfur dioxide  d water    ",
            "9": "9     \u00a9 ucles 2021 1523/22/m/j/21 [turn over  20 an excess of aqueous sodium sulfate was added to aqueous bariu m chloride and the mixture  was filtered.    which row shows the identity of the residue and the substances present in the filtrate?     residue substances in filtrate  a barium sulfate barium chloride and sodium chloride  b barium sulfate sodium chloride and sodium sulfate  c sodium chloride barium chloride and sodium sulfate  d sodium chloride barium sulfate and sodium sulfate      21 compound x is tested and the results are shown.    test result  aqueous sodium hydroxide is  added, then heated gently gas given off which turns damp  red litmus paper blue  dilute hydrochloric acid is added effervescence, gas given off  which turns limewater milky    which ions are present in compound x?  a ammonium ions and carbonate ions  b ammonium ions and chloride ions  c calcium ions and carbonate ions  d calcium ions and chloride ions     22 which statement about elements in the periodic table is correc t?  a elements are arranged in order of increasing nucleon number.  b elements in group vii are diatomic non-metals.  c elements with similar properties are in the same period.  d transition elements are a collection of metals and non-metals.      23 which statement explains why the noble gas helium is unreactiv e?  a it has a complete outer shell of electrons.  b it has two protons in the nucleus.  c it has the same number of protons and neutrons.  d it has the same number of protons, electrons and neutrons.     ",
            "10": "10  \u00a9 ucles 2021 1523/22/m/j/21  24 the positions of four elements in the periodic table are shown.     which element forms ionic compounds in which the element has di fferent oxidation numbers  (states)?    ab c d       25 the element rutherfordium, rf, was first detected in 1964.    rutherfordium is a metal.    what are the predicted properties of rutherfordium?    1 rutherfordium conducts electricity when molten.  2 rutherfordium does not conduct electricity when solid.  3 rutherfordium has a low melting point.  4 rutherfordium is malleable.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     26 the results of three reactions of metal m and its nitrate are g iven.    reaction 1 m reacts with dilute hydrochloric acid.  reaction 2 m displaces zinc metal from aqueous zinc salts.  reaction 3 heat decomposes the nitrate of m into a mixture of t wo gases and a solid.    what is m?  a copper  b iron  c magnesium  d potassium    ",
            "11": "11     \u00a9 ucles 2021 1523/22/m/j/21 [turn over  27 which statement about the extraction of aluminium from aluminiu m oxide is correct?  a aluminium is formed at the positive electrode during electroly sis.  b pure aluminium oxide is dissolved in molten cryolite.  c pure aluminium oxide is electrolysed using aluminium as the po sitive electrode.  d pure aluminium oxide is heated with carbon to form carbon diox ide and aluminium.     28 iron is extracted from its ore in a blast furnace.    the equations for four different reactions are shown.    1 4fe  +  3co 2  \uf0ae  2fe 2o3  +  3c  2 co 2  \uf0ae  c  +  o 2  3 co 2  +  c  \uf0ae  2co  4 fe 2o3  +  3co  \uf0ae  2fe  +  3co 2    which equations represent reactions that occur in the blast fur nace?  a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4     29 some uses of water are listed.    1 as a solvent  2 as a coolant in the chemical industry  3 to irrigate crops  4 to provide safe drinking water    during a drought, which uses are important to sustain the popul ation of a country?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     30 which substances are needed for iron to rust?  a carbon dioxide and oxygen  b oxygen only  c water and carbon dioxide  d water and oxygen     ",
            "12": "12  \u00a9 ucles 2021 1523/22/m/j/21  31 which process removes carbon dioxide from the atmosphere?  a cement manufacture  b combustion  c photosynthesis  d respiration     32 which statements about sulfur dioxide are correct?    1 it is produced when sulfuric acid is electrolysed.  2 it is produced when sodium sulfite reacts with dilute hydroch loric acid.  3 it is a neutral oxide.  4 it reacts with oxygen in the presence of a catalyst to form s ulfur trioxide.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4     33 what are uses of sulfur dioxide?    1 as a bleach in the manufacture of wood pulp  2 as a food preservative  3 in the conversion of iron to steel  4 to kill bacteria in water treatment    a 1 and 2 b 1 and 3 c 2 and 3 d 2 and 4     34 which type of reaction occurs when calcium oxide is formed fro m calcium carbonate?  a addition  b combustion  c neutralisation  d thermal decomposition     ",
            "13": "13     \u00a9 ucles 2021 1523/22/m/j/21 [turn over  35 the structures of some organic compounds are shown.    1 hch hch ho h2 hch hch hhh c h hch hch hhh c o h3 4 o ohch hch hc h    which compounds belong to the same homologous series?  a 1 and 2 b 1 and 3 c 2 and 3 d 3 and 4     36 the industrial fractional distillation of petroleum is shown.    kerosene fractionnaphtha fractiongasoline fractionrefinery gas diesel oil fuel oil fraction petroleum lubricating fraction and bitumeny     which process happens at y?  a burning  b condensation  c c r a c k i n g   d evaporation     ",
            "14": "14  \u00a9 ucles 2021 1523/22/m/j/21  37 which pair of compounds is used to prepare ch 3ch 2cooch 2ch 3?  a ethanoic acid and ethanol  b ethanoic acid and propanol  c propanoic acid and ethanol  d propanoic acid and propanol     38 ethanol is oxidised to ethanoic acid by acidified potassium ma nganate( vii).    which colour change is observed in the reaction?  a colourless to purple  b purple to colourless  c colourless to orange  d orange to colourless     39 the linkage between monomer units in a condensation polymer is shown.    n ho c     which types of polymer contain this linkage?    1 a complex carbohydrate  2 a polyamide  3 a polyester  4 a protein    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     ",
            "15": "15         permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international education copyright acknowledgements b ooklet. this is produced for each series of examinations and is  freely available to download  at www.cambridgeinternational.org after the live examination se ries.   cambridge assessment international education is part of the cam bridge assessment group. cambridge assessment is the brand name  of the university of  cambridge local examinations syndicate (ucles), which itself is  a department of the university of cambridge.    \u00a9 ucles 2021 1523/22/m/j/21  40 the structure of part of a polymer is shown.    cch3 hcch3 hcch3 hcch3 h    which monomer is used to make this polymer?    cca h hhh ccb h hch3 ch3 ch3 ch3ch3 hccc h hccd h h     ",
            "16": "16  \u00a9 ucles 2021 1523/22/m/j/21   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        }
    },
    "2022": {
        "0620_m22_qp_12.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib22 03_0620_12/rp   \u00a9 ucles 2022   [turn ove r   *5667682996*cambridge igcse\u2122       chemistry 0620/12     paper 1 multiple choice (core) february/march 2022     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2022 0620/12/f/m/22  1 which change of state is an exothermic process?  a condensation  b evaporation  c melting  d sublimation      2 in which state does 1  dm3 of methane contain the most particles?  a gas at 100  \uf0b0c  b gas at room temperature  c liquid  d solid     3 which dye on the chromatogram is a pure substance?    abcd      4 which piece of apparatus is used to measure exactly 5.00  cm3 of a liquid?  a 5  cm3 beaker  b 1 0  cm3 measuring cylinder  c 2 5  cm3 pipette  d 5 0  cm3 burette    ",
            "3": "3     \u00a9 ucles 2022 0620/12/f/m/22 [turn over  5 fermentation of sugar produces a mixture of ethanol solution a nd solid yeast.    how is the solid yeast removed from the mixture?  a crystallisation  b distillation  c filtration  d fractional distillation    6 matter exists as elements, compounds and mixtures.    which row identifies an element, a compound and a mixture?     element compound mixture  a calcium potassium carbonate sodium chloride  b brass sodium chloride air  c calcium sodium chloride brass  d sodium chloride water potassium carbonate     7 which pair of statements about diamond and graphite is correct ?    diamond graphite    a diamond and graphite are both pure carbon. they are both macrom olecules.  b diamond and graphite can both be used as electrodes. graphite i s also used as a lubricant.  c diamond has covalent bonds. graphite has ionic bonds.  d diamond is hard with a high melting point. graphite is soft wit h a low melting point.    ",
            "4": "4  \u00a9 ucles 2022 0620/12/f/m/22  8 an isotope of chromium is represented by cr.52 24     which statement about an atom of this isotope of chromium is co rrect?  a it contains 24 electrons.  b it contains 24 neutrons.  c it contains 28 protons.  d it contains 52 neutrons.     9 sodium is in group i of the periodic table and chlorine is in g roup vii.    which row describes what happens when sodium bonds ionically wi th chlorine?     sodium atoms ion formed chlorine atoms ion formed  a gain an electron na\u2013 lose an electron c l +  b gain an electron na+ lose an electron c l \u2013  c lose an electron na\u2013 gain an electron c l +  d lose an electron na+ gain an electron c l \u2013      10 caesium fluoride is an ionic compound.    which statements about caesium fluoride are correct?    1 it conducts electricity when solid.  2 it has a high melting point.  3 it is soluble in water. 4 it is highly volatile.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4      11 the structure of a molecule of a compound is shown.    key = c = h= o     what is the formula of this compound?  a c3h7o b c3h8o c c8h3o d c8ho 3    ",
            "5": "5     \u00a9 ucles 2022 0620/12/f/m/22 [turn over  12 calcium carbonate, caco 3, reacts with dilute hydrochloric acid to produce carbon dioxid e.    the equation for the reaction is shown. the relative formula ma ss of calcium carbonate is 100.    caco 3  +  2hc l  \uf0ae  cac l 2  +  h 2o  +  co 2    10  g of calcium carbonate is reacted with an excess of dilute hydr ochloric acid.    which mass of carbon dioxide is produced?  a 2.2  g b 2.8  g c 4.4  g d 44  g      13 molten sodium chloride and concentrated aqueous sodium chloride  are electrolysed using  platinum electrodes.    what are the products at the negative electrode (cathode) in ea ch electrolysis?     molten  sodium chloride concentrated aqueous  sodium chloride  a hydrogen hydrogen  b hydrogen sodium  c sodium hydrogen  d sodium sodium     14 an object is electroplated with silver using an aqueous silver  salt as the electrolyte.    which row is correct?     the object to be  electroplated is the the other electrode  is made from  a anode carbon  b anode silver  c cathode carbon  d cathode silver     ",
            "6": "6  \u00a9 ucles 2022 0620/12/f/m/22  15 which row describes the changes that occur in an endothermic r eaction?     energy change temperature  a   energy given out to  the surroundings decreases    b   energy given out to  the surroundings increases    c   energy taken in from  the surroundings decreases    d   energy taken in from  the surroundings increases       16 which statement about fuels is correct?  a heat energy is only produced by burning fuels.  b hydrogen is used as a fuel although it is difficult to store.  c methane is a good fuel because it produces only water when bur ned.  d uranium is burned in air to produce energy.     17 a sequence of changes involving sulfur is shown.    s solidchange 1s liquidso2 gaschange 2     which row describes the changes?     change 1 change 2  a chemical chemical  b chemical physical  c physical chemical  d physical physical     18 magnesium is added to dilute hydrochloric acid.    25  cm3 of gas is given off in the first 30  s of the reaction.    the experiment is repeated at a lower temperature. all other re action conditions are the same.    which volume of gas is produced in the first 30  s of this reaction?  a 1 5  cm3 b 2 5  cm3 c 3 0  cm3 d 5 0  cm3     ",
            "7": "7     \u00a9 ucles 2022 0620/12/f/m/22 [turn over  19 the equation for the reaction between magnesium and copper( ii) oxide is shown.    mg  +  cuo  \uf0ae  mgo  +  cu    which substance is oxidised?  a c u  b c u o  c m g  d m g o      20 methyl orange is added to dilute hydrochloric acid and to aque ous sodium hydroxide.    what is the colour of the methyl orange in each solution?     colour in dilute  hydrochloric acid colour in aqueous  sodium hydroxide  a orange red  b red yellow  c red orange  d yellow red     21 compound x is dissolved in water and two separate samples of t he solution are tested.    the results of the tests are shown.    test observation  add aqueous sodium hydroxide   a white precipitate forms  which is insoluble in excess  acidify with dilute nitric acid  and add aqueous silver nitrate a yellow precipitate forms      what is compound x?  a calcium chloride  b calcium iodide  c zinc chloride  d zinc iodide     22 which statement about the periodic table is correct?  a elements with the highest atomic number in each period are meta llic.  b elements with the lowest group numbers are non-metals.  c elements with similar chemical properties are placed in groups.   d elements with similar physical properties are placed in periods .    ",
            "8": "8  \u00a9 ucles 2022 0620/12/f/m/22  23 part of the periodic table is shown.    which element is a soft solid that reacts violently with cold w ater?    dca b      24 three properties of element x are listed.    \u25cf it contains atoms with a full outer shell of electrons.  \u25cf it is monoatomic.  \u25cf it is unreactive.    in which part of the periodic table is the element placed?  a group i  b group vii  c group viii  d transition elements     25 some properties of the elements in group vii of the periodic ta ble are shown.    element melting  point  / \uf0b0c boiling  point  / \uf0b0c colour  f \u2013220 \u2013188 pale yellow  cl \u2013101 \u201335 green  br \u20137 59 brown  i 114 184   at 302 380     which statement is correct?  a bromine is a brown solid at room temperature.  b fluorine is a pale yellow gas at room temperature.  c iodine is a brown liquid at room temperature.  d astatine is a black liquid at room temperature.     ",
            "9": "9     \u00a9 ucles 2022 0620/12/f/m/22 [turn over  26 which process is used to obtain  the metal calcium from its ore?   a electrolysis  b oxidation with carbon  c reduction with carbon  d thermal decomposition      27 which row links the proper ty of a metal to its use?     property use  a high density aircraft bodies  b high reactivity food containers  c good electrical conductor cooking pans  d ductile electrical wiring      28 the table gives some properties of an element.    melting point in \uf0b0c 3422  appearance of the element grey  appearance of the chloride of the element dark blue  density in g  / cm3 19.2  electrical conductivity when solid good    which other property does this element have?  a acts as a catalyst  b brittle  c forms an acidic oxide  d highly reactive with water    29 a metal reacts vigorously with cold water.    which statement about the metal is correct?  a it is above hydrogen in the reactivity series.  b it is below magnesium in the reactivity series.  c its oxide can be reduced with carbon.  d it does not react with dilute acids.    ",
            "10": "10  \u00a9 ucles 2022 0620/12/f/m/22  30 which row describes the colour changes when water is added to a nhydrous cobalt( ii) chloride  and anhydrous copper( ii) sulfate?     anhydrous  cobalt( ii) chloride anhydrous  copper( ii) sulfate  a blue to pink white to blue  b blue to white blue to pink  c pink to blue blue to white  d white to blue pink to blue     31 the gases produced by a burning fuel are passed through soluti on z using the apparatus shown.    the fuel contains compounds of sulfur.    to vacuum pump solution z burning fuel     which row identifies solution z and the result obtained when th e fuel contains compounds of  sulfur?     solution z result  a acidified potassium manganate( vii) turns colourless  b acidified potassium manganate( vii) turns purple  c litmus bleached  d litmus turns blue     ",
            "11": "11     \u00a9 ucles 2022 0620/12/f/m/22 [turn over  32 which information about carbon dioxide and methane is correct?       carbon dioxide methane   a formed when vegetation decomposes \u0016 \u001a k e y   b greenhouse gas \u0016 \u0016 \u0016 = correct  c present in unpolluted air \u001a \u001a \u001a = not correct  d produced during respiration \u001a \u0016       33 which row identifies uses of sulfur?     use 1 use 2 use 3  a making ammonia bleaching wood pulp food preservative  b making sulfuric acid bleaching wood pulp food preservative  c making sulfuric acid food preservative as an npk fertiliser  d making ammonia food preservative as an npk fertiliser      34 which statements about lime are correct?    1 lime is made by heating calcium carbonate (limestone).  2 lime is used to desulfurise flue gases. 3 lime is used to treat alkaline soil.  4 the chemical name for lime is calcium oxide.    a 1 and 3 b 1, 2 and 4 c 1 and 4 only d 2, 3 and 4    35 which structure is correctly named?    a ethanoic acidcc ch hhhh oo hb ethenehc ch h hh hc ethanolhc ch h hh o hd propanecch h hhh c h      ",
            "12": "12  \u00a9 ucles 2022 0620/12/f/m/22  36 the fractional distillation of petroleum produces a series of f ractions with different uses.    which row identifies a use for a fraction?     f r a c t i o n  u s e   a bitumen jet fuel  b gas oil cooking  c kerosene making roads  d naphtha making chemicals     37 ethene and propene are both members of the same homologous seri es.    which statements explain why ethene and propene have similar ch emical properties?    1 they are both hydrocarbons.  2 they are both made by cracking. 3 they have the same functional group.    a 1 and 2 b 1 and 3 c 2  o n l y  d 3  o n l y      38 which statement about ethane is correct?  a it decolourises bromine water.  b it burns in excess oxygen to form water and carbon dioxide.  c its molecular formula is c 2h4.  d its atoms are joined together by ionic bonding.    39 which statements about ethanol are correct?    1 ethanol is used as a solvent.  2 ethanol can be made directly from ethane.  3 ethanol is a covalent compound.    a 1 only b 1 and 2 c 1 and 3 d 2 and 3     ",
            "13": "13     \u00a9 ucles 2022 0620/12/f/m/22 40 polymers are long-chain molecules made from small molecules li nked together.    four polymers or types of polymer are listed.    1 carbohydrates  2 nylon 3 proteins 4 terylene     which polymers or types of polymer are synthetic?  a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4   ",
            "14": "14    blank page   \u00a9 ucles 2022 0620/12/f/m/22  ",
            "15": "15    blank page       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.    cambridge assessment international education is part of cambrid ge assessment. cambridge assessment is the brand name of the un iversity of cambridge  local examinations syndicate (ucles), which is a department of the university of cambridge.    \u00a9 ucles 2022 0620/12/f/m/22  ",
            "16": "16  \u00a9 ucles 2022 0620/12/f/m/22   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m22_qp_22.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib22 03_0620_22/rp   \u00a9 ucles 2022   [turn ove r   *3837715510*cambridge igcse\u2122       chemistry 0620/22     paper 2 multiple choice (extended)  february/march 2022     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2022 0620/22/f/m/22  1 which gas has the fastest rate of diffusion?  a h 2 b c h 4 c c o 2 d s o 2     2 in which state does 1  dm3 of methane contain the most particles?  a gas at 100  \uf0b0c  b gas at room temperature  c liquid  d solid     3 which statement explains why isotopes of the same element have  the same chemical properties?  a they have the same electronic structure.  b they have the same relative mass.  c they have the same nucleon number.  d they have the same proton number.    4 the electronic structures of atoms p and q are shown.    p q     p and q form an ionic compound.    what is the formula of the compound?  a p q  b p 2q c p 2q3 d p q 2     5 fermentation of sugar produces a mixture of ethanol solution a nd solid yeast.    how is the solid yeast removed from the mixture?  a crystallisation  b distillation  c filtration  d fractional distillation    ",
            "3": "3     \u00a9 ucles 2022 0620/22/f/m/22 [turn over  6 which row explains why copper is a good conductor of electrici ty at room temperature?     copper ions  move freely electrons  move freely  a no no  b no yes  c yes no  d yes yes     7 which pair of statements about diamond and graphite is correct ?    diamond graphite    a diamond and graphite are both pure carbon. they are both macrom olecules.  b diamond and graphite can both be used as electrodes. graphite i s also used as a lubricant.  c diamond has covalent bonds. graphite has ionic bonds.  d diamond is hard with a high melting point. graphite is soft wit h a low melting point.     8 sodium nitride contains the nitride ion, n 3\u2013.    sodium nitride is unstable and decomposes into its elements.    what is the equation for the decomposition of sodium nitride?  a 2 n a n 3  \uf0ae  2na  +  3n 2  b 2 n a 3n  \uf0ae  6na  +  n 2  c 2 n a n 3  \uf0ae  na 2  +  3n 2  d 2 n a 3n  \uf0ae  6na  +  2n    9 compound x contains carbon, hydrogen and oxygen only.    by mass, it contains 26.7% carbon and 2.2% hydrogen.    what is the empirical formula of x?  a cho b c 2ho c c h 2o d cho 2   ",
            "4": "4  \u00a9 ucles 2022 0620/22/f/m/22  10 caesium fluoride is an ionic compound.    which statements about caesium fluoride are correct?    1 it conducts electricity when solid.  2 it has a high melting point. 3 it is soluble in water. 4 it is highly volatile.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4     11 which diagram shows the direction of movement of ions and elect rons during the electrolysis of  molten sodium chloride?    cl \u2013e\u2013 na+e\u2013power supplya cathode anode cl \u2013e\u2013 na+ cl \u2013na+e\u2013power supplyb cathode anode cl \u2013e\u2013 na+e\u2013power supplyc anode cathode e\u2013 e\u2013power supplyd anode cathode      ",
            "5": "5     \u00a9 ucles 2022 0620/22/f/m/22 [turn over  12 calcium carbonate, caco 3, reacts with dilute hydrochloric acid to produce carbon dioxid e.    the equation for the reaction is shown. the relative formula ma ss of calcium carbonate is 100.    caco 3  +  2hc l  \uf0ae  cac l 2  +  h 2o  +  co 2    10  g of calcium carbonate is reacted with an excess of dilute hydr ochloric acid.    which mass of carbon dioxide is produced?  a 2.2  g b 2.8  g c 4.4  g d 44  g      13 molten sodium chloride and concentrated aqueous sodium chloride  are electrolysed using  platinum electrodes.    what are the products at the negative electrode (cathode) in ea ch electrolysis?     molten  sodium chloride concentrated aqueous  sodium chloride  a hydrogen hydrogen  b hydrogen sodium  c sodium hydrogen  d sodium sodium     14 an object is electroplated with silver using an aqueous silver  salt as the electrolyte.    which row is correct?     the object to be  electroplated is the the other electrode  is made from  a anode carbon  b anode silver  c cathode carbon  d cathode silver     ",
            "6": "6  \u00a9 ucles 2022 0620/22/f/m/22  15 which row describes the changes that occur in an endothermic r eaction?     energy change temperature  a   energy given out to  the surroundings decreases    b   energy given out to  the surroundings increases    c   energy taken in from  the surroundings decreases    d   energy taken in from  the surroundings increases       16 which statement about fuels is correct?  a heat energy is only produced by burning fuels.  b hydrogen is used as a fuel although it is difficult to store.  c methane is a good fuel because it produces only water when bur ned.  d uranium is burned in air to produce energy.      17 which statement about endothermic and exothermic reactions is correct?  a in an endothermic reaction, less energy is absorbed in bond bre aking than is released in  bond forming.  b in an endothermic reaction, the activation energy is always hig her than in an exothermic  reaction.  c in an exothermic reaction, more energy is absorbed in bond brea king than is released in  bond forming.  d in an exothermic reaction, the reactants are higher on an energ y level diagram than the  products.     ",
            "7": "7     \u00a9 ucles 2022 0620/22/f/m/22 [turn over  18 the reaction used to manufacture ammonia from nitrogen and hydr ogen is reversible.    an equilibrium is established between ammonia, nitrogen and hyd rogen.    which statement describes the equilibrium?  a both the forward reaction and the backward reaction have the s ame rate.  b the rate of the backward reaction is greater than the rate of the forward reaction.  c the rate of the forward reaction is greater than the rate of t he backward reaction.  d the forward and backward reactions have both stopped.     19 how does increasing the concentration affect the reacting parti cles in a chemical reaction?     increases the  collision rate increases the proportion  of particles with the  activation energy  a \u0016 \u001a  b \u0016 \u0016  c \u001a \u001a  d \u001a \u0016     20 methyl orange is added to dilute hydrochloric acid and to aque ous sodium hydroxide.    what is the colour of the methyl orange in each solution?     colour in dilute  hydrochloric acid colour in aqueous  sodium hydroxide  a orange red  b red yellow  c red orange  d yellow red     ",
            "8": "8  \u00a9 ucles 2022 0620/22/f/m/22  21 zinc oxide is an amphoteric oxide.    which types of substances will react with zinc oxide?  a acids and bases  b acids only  c bases only  d neither acids nor bases    22 information about some silver compounds is shown.    compound formula solubility in water  silver carbonate ag 2co 3 insoluble  silver chloride agc l insoluble  silver nitrate agno 3 soluble  silver oxide ag 2o insoluble    which equation shows a reaction which cannot  be used to make a silver salt?  a agno 3(aq)  +  hc l (aq)  \uf0ae  agc l (s)  +  hno 3(aq)  b ag2o(s)  +  2hno 3(aq)  \uf0ae  2agno 3(aq)  +  h 2o(l)  c ag2co 3(s)  +  2hno 3(aq)  \uf0ae  2agno 3(aq)  +  h 2o(l)  +  co 2(g)  d 2ag(s)  +  2hc l (aq)  \uf0ae  2agc l (s)  +  h 2(g)     23 aqueous ethanoic acid is a weak acid.    aqueous sodium hydroxide is a strong base.    aqueous ethanoic acid is neutralised by aqueous sodium hydroxid e.    which statements are correct?    1 aqueous ethanoic acid accepts protons from hydroxide ions.  2 the aqueous ethanoic acid used is fully dissociated into ions .  3 the aqueous sodium hydroxide used is fully dissociated into i ons.  4 the reaction produces a salt and water.    a 1 and 2 b 1 and 3 c 2 and 4 d 3 and 4    ",
            "9": "9     \u00a9 ucles 2022 0620/22/f/m/22 [turn over  24 three properties of element x are listed.    \u25cf it contains atoms with a full outer shell of electrons.  \u25cf it is monoatomic.  \u25cf it is unreactive.    in which part of the periodic table is the element placed?  a group i  b group vii  c group viii  d transition elements     25 which word equation represents a reaction that occurs?  a sodium oxide + carbon \uf0ae sodium + carbon dioxide  b sodium oxide + iron \uf0ae sodium + iron ( ii) oxide  c i r o n (ii) oxide + copper \uf0ae iron + copper (ii) oxide  d i r o n (iii) oxide + carbon \uf0ae iron + carbon dioxide      26 which statement about the extraction of aluminium is correct?  a aluminium is formed at the cathode during the electrolysis of aluminium oxide.  b hematite is mainly aluminium oxide.  c molten cryolite is used to raise the melting point of the alum inium oxide.  d oxygen gains electrons at the anode during the electrolysis of  aluminium oxide.      27 metal m is mixed with copper to produce brass.    what is m?  a chromium  b nickel  c vanadium  d z i n c     ",
            "10": "10  \u00a9 ucles 2022 0620/22/f/m/22  28 the table gives some properties of an element.    melting point in \uf0b0c 3422  appearance of the element grey  appearance of the chloride of the element dark blue  density in g  / cm3 19.2  electrical conductivity when solid good    which other property does this element have?  a acts as a catalyst  b brittle  c forms an acidic oxide  d highly reactive with water    29 ammonia is produced using the haber process.    which row shows the source of the raw materials and the reactio n conditions?     source of  nitrogen source of  hydrogen temperature  /  \uf0b0c pressure  / atm  a air hydrocarbons 200 200  b hydrocarbons air 450 2  c air hydrocarbons 450 200  d air hydrocarbons 450 2      30 how many species are acting as bases in this reversible reactio n?    hno 3  +  h 2o    h3o+  +  no 3\u2013    a 3 b  2 c  1 d  0    ",
            "11": "11     \u00a9 ucles 2022 0620/22/f/m/22 [turn over  31 the equation for a reaction occurring in the contact process i s shown.    2so 2  +  o 2  \uf0ae  2so 3    what is the catalyst used in this reaction?  a iron  b phosphoric( v) acid  c s u l f u r i c  a c i d   d vanadium( v) oxide     32 which information about carbon dioxide and methane is correct?       carbon dioxide methane   a formed when vegetation decomposes \u0016 \u001a k e y   b greenhouse gas \u0016 \u0016 \u0016 = correct  c present in unpolluted air \u001a \u001a \u001a = not correct  d produced during respiration \u001a \u0016      33 the structure of an ester is shown.    c oo cch hc hh hhh ch hh     what are the names of the carboxylic acid and the alcohol that react together to form this ester?     carboxylic acid alcohol  a ethanoic acid ethanol  b ethanoic acid propan-1-ol  c propanoic acid ethanol  d propanoic acid propan-1-ol     ",
            "12": "12  \u00a9 ucles 2022 0620/22/f/m/22  34 which statements about lime are correct?    1 lime is made by heating calcium carbonate (limestone).  2 lime is used to desulfurise flue gases.  3 lime is used to treat alkaline soil.  4 the chemical name for lime is calcium oxide.    a 1 and 3 b 1, 2 and 4 c 1 and 4 only d 2, 3 and 4     35 which structure is correctly named?    a ethanoic acidcc ch hhhh oo hb ethenehc ch h hh hc ethanolhc ch h hh o hd propanecch h hhh c h      36 the structure of part of a polymer is shown.    c hcl ch ch3c hcl ch ch3c hcl     which monomers can be used to make this polymer?    1 c ch ch3 cl hc2 ch ch3cl h3 c c hch3 cl hch3 cl c4 c cl h    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    ",
            "13": "13     \u00a9 ucles 2022 0620/22/f/m/22 [turn over  37 carboxylic acids are made by the oxidation of alcohols.    which carboxylic acid is produced from ch 3ch 2oh?  a butanoic acid  b ethanoic acid  c methanoic acid  d propanoic acid    38 propene, c 3h6, reacts with bromine, br 2, in an addition reaction.    which structure represents the product of this reaction?    hch brca h hchh h hch brbr cb hch hh hch br brcc h ch hh ch br br cd h h hch h      39 which statements about ethanol are correct?    1 ethanol is used as a solvent.  2 ethanol can be made directly from ethane. 3 ethanol is a covalent compound.    a 1 only b 1 and 2 c 1 and 3 d 2 and 3    ",
            "14": "14  \u00a9 ucles 2022 0620/22/f/m/22  40 which diagram represents the structure of nylon?    co co o o co co n h co co n hn h co co o n ha b c d      ",
            "15": "15    blank page       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.   to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.    cambridge assessment international education is part of cambrid ge assessment. cambridge assessment is the brand name of the un iversity of cambridge  local examinations syndicate (ucles), which is a department of the university of cambridge.    \u00a9 ucles 2022 0620/22/f/m/22  ",
            "16": "16  \u00a9 ucles 2022 0620/22/f/m/22   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_m22_qp_32.pdf": {
            "1": "*2554114949* chemistry  0620/32 paper 3 theory (core) february/march 2022  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib22 03_0620_32/3rp \u00a9 ucles 2022 [turn overthis document has 20 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/32/f/m/22 \u00a9 ucles 2022 1 (a)\t\tthe\telectronic\tstructures\tof\tfive\tatoms,\ta,\tb,\tc,\td\tand\te,\tare\tshown. a b c d e \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\telectronic\tstructures. \t\teach\telectronic\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall. \t\tstate\twhich\telectronic\tstructure,\t a,\tb,\tc,\td or e,\trepresents:  (i)\t\tan\tatom\tin\tgroup\tv\tof\tthe\tperiodic\t table  \t ...   [1]  (ii)\t\tan\tatom\twhich\tcontains\tonly\ttwo\tshells\t of\telectrons  \t ...   [1]  (iii)\t\tan\tatom\tthat\tforms\ta\tstable\tion\twith\ta\tcharge\tof\t2\u2013  \t ...   [1]  (iv)\t\tan\tatom\tof\tan\telement\tthat\texists\tas\ta\tmonoatomic\tgas  \t ...   [1]  (v)\t\tan\tatom\tof\tthe\tmetal\tthat\tis\textracted\tfrom\tbauxite.  \t ...   [1]  (b)\t\tcomplete\t the\ttable\tto\tshow\tthe\tnumber\tof\telectrons,\t neutrons\tand\tprotons\tin\tthe\turanium\tatom\t and\trubidium\tion\tshown. number\tof\telectrons number\tof\tneutrons number\tof\tprotons 235u92 92 87rb+ 37 50  [3] \t [total:\t8]",
            "3": "3 0620/32/f/m/22 \u00a9 ucles 2022 [turn over 2 (a)\t\tbiogas\tis\ta\tmixture\tof\tgases\tproduced\t when\tagricultural\t waste\tis\tbroken\tdown\tin\tthe\tabsence\t of\toxygen. \t\tthe\ttable\tcompares\t the\tpercentage\t by\tmass\tof\tthe\tgases\tpresent\tin\ttwo\tsamples\tof\tbiogas,\t x  and\ty. gasbiogas\t x /\t%\tby\tmassbiogas\t y /\t%\tby\tmass carbon\tdioxide 26 32 hydrogen 1 1 hydrogen\tsulfide 0.5 0.5 methane 67 56 nitrogen 4 9.5 oxygen 0.5 0.5 other\tgases 0.5 \t\tanswer\tthese\tquestions\tusing\tonly\tthe\tinformation\tin\tthe\ttable.  (i)\t\tdeduce\tthe \tpercentage\tby\tmass\tof\tthe\tother\tgases\tin\tbiogas\t x.  \t ...   [1]  (ii)\t\tdescribe\t two\tmajor\tdifferences\tin\tthe\tcompositions\tof\tbiogas\t x\tand\tbiogas\t y.  1 \t .. \t 2\t\t .. \t [2]  (b)\t\tcomplete\tthe\tdiagram\tto\tshow\tthe\telectronic\tstructure\tin\ta\tmethane\tmolecule. \t\tshow\tonly\tthe\touter\tshell\telectrons.  [1]",
            "4": "4 0620/32/f/m/22 \u00a9 ucles 2022  (c)\t\thydrogen\tsulfide\tburns\tin\tair\tto\tproduce\tsulfur\tdioxide\tand\twater.  (i)\t\tcomplete\tthe\tchemical\tequation\tfor\tthis \treaction. \t .h2s\t\t+\t\t.o2  \u2192\t\t2h2o\t\t+\t\t2so2\t [2]  (ii)\t\texplain\thow \tthis\tequation\tshows\tthat\thydrogen\tsulfide\tis\toxidised.  \t .  \t ...   [1] \t [total:\t7]",
            "5": "5 0620/32/f/m/22 \u00a9 ucles 2022 [turn over 3\t\tthis\tquestion\tis\tabout\tmetals.  (a)\t\tstate\tthree\tgeneral\tphysical\tproperties\tcommon\tto\tmost\tmetals.  1 \t. \t 2\t\t .  3 \t.  [3]  (b)\t\tmetals\tare\toften\tused\tin\tthe\tform\tof\talloys.  (i)\t\tstate\tthe\tmeaning\tof\tthe\tterm\talloy .  \t .  \t ...   [1]  (ii)\t\texplain\tin\tterms\tof\ttheir\tproperties\twhy\t alloys\tare\tused\tinstead\tof\tpure\tmetals.  \t ...   [1]  (iii)\t\tstainless\tsteel\tis\tan\talloy. \t \tgive\tone\tuse\tof\tstainless\tsteel.  \t ...   [1]  (c)\t\tplace\tthese\tmetals\tin\torder\tof\ttheir\treactivity\twith\toxygen. copper magnesium potassium zinc \t\tput\tthe\tleast\treactive\tmetal\tfirst. least reactive most reactive \t [2]",
            "6": "6 0620/32/f/m/22 \u00a9 ucles 2022  (d)\t\twhen\t4.8\t g\tof\tmagnesium\treacts\twith\texcess\toxygen,\t8.0\t g\tof\tmagnesium\toxide\tis\tformed. \t\tcalculate\tthe\tminimum\tmass\tof\tmagnesium\tneeded\tto\tproduce\t24.0\t g\tof\tmagnesium\toxide. \t minimum\tmass\t=\t..\tg\t\t[1] \t [total:\t9]",
            "7": "7 0620/32/f/m/22 \u00a9 ucles 2022 [turn over 4\t\tthis\tquestion\tis\tabout\tacids,\tbases\tand\tsalts.  (a)\t\tsodium\thydroxide\tis\ta\tbase.  (i)\t\tname\tthe\tproducts\tformed\twhen\tsodium \thydroxide\treacts\twith\tdilute\tnitric\tacid.  \t .  \t ... \t\t[2]  (ii)\t\tdescribe\tthe\teffect\tof\tsodium\thydroxide \ton\ta\tnamed\tindicator.  \t .  \t ... \t\t[2]  (iii)\t\tcomplete\t the\tword\tequation\tfor\tthe\treaction\tof\tsodium\thydroxide\t with\tammonium\t chloride. sodium hydroxide+ammonium chloride+ +water \t [2]  (b)\t\tdescribe\thow\tto\tprepare\tpure,\tdry\tcrystals\tof\tthe\tsalt\tzinc\tsulfate\tfrom\tan\taqueous\tsolution\tof\t zinc\tsulfate.  \t  \t  \t.. \t\t[2]",
            "8": "8 0620/32/f/m/22 \u00a9 ucles 2022  (c)\t\tthe\trate\tof\treaction\tof\tzinc\tpowder\twith\tdilute\tsulfuric\tacid\tis\tfound\tby\tmeasuring\t the\tincrease\t in\tvolume\tof\thydrogen\tgas\tproduced\tas\ttime\tincreases. \t\tdescribe\tthe\teffect,\tif\tany,\tof\teach\tof\tthe\tfollowing\ton\tthe\trate\tof\tthis\treaction.  \u25cf\tthe\treaction\tis\tcarried\tout\twith\tlarge\tpieces\tof\tzinc\tinstead\tof\tzinc\tpowder. \t\tall\tother\tconditions\tstay\tthe\tsame.  \t  \u25cf\tthe\treaction\tis\tcarried\tout\tusing\ta\tcatalyst. \t\tall\tother\tconditions\tstay\tthe\tsame.  \t  \u25cf\tthe\treaction\tis\tcarried\tout\twith\tdilute\tsulfuric\tacid\tof\ta\tlower\tconcentration. \t\tall\tother\tconditions\tstay\tthe\tsame.  \t  [3] \t [total:\t11]",
            "9": "9 0620/32/f/m/22 \u00a9 ucles 2022 [turn over 5\t\tthis\tquestion\tis\tabout\tair.  (a)\t\tthe\tpie\tchart\tshows\tthe\tproportions\tof\tthe\tmain\tgases\tin\tclean,\tdry\tair. gas g gas h  (i)\t\tname\tthe\tgases\tg\tand\th. \t gas\tg \t .. \t gas\th \t .. \t [2]  (ii)\t\tthe\tgraph\tshows\thow\tthe\tvolume\tof\ta\tsample\tof\tgas\tg\tchanges\tas\ttemperature\t increases. \t \tthe\tpressure\tis\tkept\tconstant. volume of gas g / cm3 temperature  / /g113c \t \tdescribe\thow\tthe\tvolume\tof\tgas\t g\tchanges\tas\ttemperature\tincreases.  \t ...   [1]  (iii)\t\tthere\tis\ta\tsmall\tpercentage\tof\tnoble\tgases\tin\tthe\tair. \t \tthe\tnoble\tgases\tare\tunreactive. \t \texplain\twhy\tthe\tnoble\tgases\tare\tunreactive\tin\tterms\tof\ttheir\telectronic\tstructure.  \t .  \t ...   [1]  (iv)\t\tdescribe\tthe\tarrangement\tand\tseparation\tof\tthe\tparticles\tin\ta\tgas. \t arrangement\t \t ... \t separation\t \t ... \t [2]",
            "10": "10 0620/32/f/m/22 \u00a9 ucles 2022  (b)\t\ttwo\tof\tthe\tpollutants\tin\tair\tare\toxides\tof\tnitrogen\tand\tlead\tcompounds.  (i)\t\tgive\tone\teffect\tof\teach\tof\tthese\tpollutants\ton\thealth. \t oxides\tof\tnitrogen\t \t ... \t lead\tcompounds\t \t . \t [2]  (ii)\t\tname\ttwo\tother\tpollutants\tpresent\tin\tair. \t \tstate\tthe\tsource\tof\teach\tof\tthese\tpollutants. \t pollutant\t1\t \t ... \t source\tof\tpollutant\t1\t \t ... \t pollutant\t2\t \t ... \t source\tof\tpollutant\t2\t \t ...  [4] \t [total:\t12]",
            "11": "11 0620/32/f/m/22 \u00a9 ucles 2022 [turn over 6\t\tthe\ttable\tshows\tsome\tproperties\tof\tfour\tgroup\ti \telements. elementmelting\tpoint / \u00b0cboiling\tpoint / \u00b0crelative\thardness lithium 181 1342 sodium 980.70 potassium 63 760 0.36 rubidium 39 686 0.22  (a) (i)\t\tcomplete\tthe\ttable\tby\testimating:  \u25cf\tthe\tboiling\tpoint\tof\tsodium  \u25cfthe\trelative\thardness\tof\tlithium.\t [2]  (ii)\t\tpredict\tthe\tphysical\tstate\tof\tlithium\tat\t200\t \u00b0c. \t \tgive\ta\treason\tfor\tyour\tanswer.  \t .  \t ... \t\t[2]  (b)\t\tpotassium\treacts\twith\twater. 2k\t\t+\t\t2h2o\t\t\u2192\t\t2koh\t\t+\t\th2 \t\tdescribe\t two\tobservations\twhen\tpotassium\treacts\twith\twater.  1 \t. \t 2\t\t . \t [2]",
            "12": "12 0620/32/f/m/22 \u00a9 ucles 2022  (c)\t\tlithium\tis\textracted\tby\tthe\telectrolysis\tof\tmolten\tlithium\tchloride.  (i)\t\tname\ta\tnon-metal\tused\tto\tmake\tthe\telectrodes.  \t ...   [1]  (ii)\t\tgive\tone\tproperty,\t other\tthan\tthe\tconduction\t of\telectricity,\t that\tmakes\tthis\tsubstance\t suitable\tfor\tuse\tas\tan\telectrode.  \t ...   [1]  (iii)\t\tstate\tthe\tproducts\tof\tthe\telectrolysis\tof\tmolten\tlithium\tchloride\tat: \t the\tnegative\telectrode\t(cathode)\t \t  \t the\tpositive\telectrode\t(anode).\t \t ... \t [2]  (d)\t\tlithium\tchloride\tconducts\telectricity\twhen\tmolten\tand\twhen\tin\taqueous\tsolution. \t\tgive\ttwo\tother\tphysical\tproperties\tof\tlithium\tchloride\tthat\tshow\tit\tis\tan\tionic\tcompound.  1 \t. \t 2\t\t . \t [2] \t [total:\t12]",
            "13": "13 0620/32/f/m/22 \u00a9 ucles 2022 [turn over 7 (a)\t\tthe\tstructures\tof\tfour\torganic\tcompounds,\t p,\tq,\tr\tand\ts,\tare\tshown. pq hch hch hohs hch hch hh hch o ohch hchch h hc hr h hhchh hcc \t\tanswer\tthe\tfollowing\tquestions\tabout\tthese\tstructures. \t\teach\tstructure\tmay\tbe\tused\tonce,\tmore\tthan\tonce\tor\tnot\tat\tall.  (i)\t\tstate\twhich\tstructure,\tp,\tq,\tr or s,\thas\ta\tcarboxylic\tacid\tfunctional\tgroup.  \t ...   [1]  (ii)\t\tstate\twhich\tstructure,\tp,\tq,\tr or s,\tis\tin\tthe\tsame\thomologous\tseries\tas\tethane.  \t ...   [1]  (iii)\t\tstate\twhich\tstructure,\tp,\tq,\tr or s,\tdecolourises\taqueous\tbromine.  \t ...   [1]  (iv)\t\tdeduce\tthe\tmolecular\t formula\tof\tstructure\t q\tto\tshow\tthe\tnumber\tof\tcarbon,\thydrogen\t and\t oxygen\tatoms.  \t ...   [1]  (b)  structure s\tis\tproduced\tby\tcracking\tpetroleum\tfractions.  (i)\t\tcomplete\tthe\tsentence\tusing\ta\tword\tfrom\tthe\tlist. acids          alkenes          alcohols          nitrogen \t \tduring\tcracking,\t long-chain\t alkanes\tare\tconverted\t to\tshorter\tchain\talkanes\tand\t  \t \t.\t [1]  (ii)\t\tcracking\tis \tan\texample\tof\tthermal\tdecomposition. \t \tstate\tthe\tmeaning\tof\tthe\tterm\tthermal decomposition .  \t .  \t ... \t\t[2]",
            "14": "14 0620/32/f/m/22 \u00a9 ucles 2022  (c)\t\tlink\teach\tpetroleum\tfraction\ton\tthe\tleft\tto\tits\tuse\ton \tthe\tright. \t\tthe\tfirst\tone\thas\tbeen\tdone\tfor\tyou. fraction refinery gas naphtha lubricating fraction keroseneuse making chemicals bottled gas jet fuel waxes and polishes \t [2] \t [total:\t9]",
            "15": "15 0620/32/f/m/22 \u00a9 ucles 2022 [turn over 8\t\tthis\tquestion\tis\tabout\tchlorine\tand\tcompounds\tof\tchlorine.  (a)\t\tchlorine\tis\tan\telement\tin\tgroup\tvii\tof\tthe\tperiodic\t table. \t\tstate\tthe\tmeaning\tof\tthe\tterm\telement .  \t  \t..   [1]  (b)\t\tstate\tone\tuse\tof\tchlorine.  \t..   [1]  (c)\t\tchlorine\treacts\twith\tphosphorus\tto\tproduce\tphosphorus( v)\tchloride.  (i)\t\tbalance\tthe \tequation\tfor\tthis\treaction. \t .p\t\t+\t\t.c l 2  \u2192\t\t2pcl 5\t [2]  (ii)\t\tthis\treaction\tis\texothermic. \t \tstate\tthe\tmeaning\tof\tthe\tterm\texothermic.  \t ...   [1]  (d)\t\tchlorine\treacts\twith\taqueous\tsodium\tbromide.  (i)\t\tcomplete\tthe\tword\tequation\tfor\tthis\treaction. chlorine +sodium bromide+  \t [2]  (ii)\t\tdescribe\ta\t test\tfor\tbromide\tions.  test \t .. \t observations\t \t ... \t [2]  (iii)\t\twhen\tbromine\tis\tmixed\twith\taqueous\tsodium\tchloride\tthere\tis\tno\treaction. \t \tsuggest\tin\tterms\tof\tchemical\treactivity\twhy\tthere\tis\tno\treaction.  \t ...   [1]",
            "16": "16 0620/32/f/m/22 \u00a9 ucles 2022  (e)\t\ta\tcompound\tof\tchlorine\thas\tthe\tformula\tc3h6cl 2. \t\tcomplete\tthe\ttable\tto\tcalculate\tthe\trelative\tmolecular\tmass\tof\tc3h6cl 2. atom number\tof\tatomsrelative atomic\tmass carbon 3 12 3 \u00d7\t12\t=\t36 hydrogen 1 chlorine 35.5 \t relative\tmolecular\tmass\t=\t..\t\t[2] \t [total:\t12]",
            "17": "17 0620/32/f/m/22 \u00a9 ucles 2022blank page",
            "18": "18 0620/32/f/m/22 \u00a9 ucles 2022blank page",
            "19": "19 0620/32/f/m/22 \u00a9 ucles 2022blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge.",
            "20": "20 0620/32/f/m/22 \u00a9 ucles 2022 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_m22_qp_42.pdf": {
            "1": "*1831070697* chemistry  0620/42 paper 4 theory (extended) february/march 2022  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib22 03_0620_42/3rp \u00a9 ucles 2022 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/42/f/m/22 \u00a9 ucles 2022 1\t\tthis\tquestion\tis\tabout\tthe\tfirst\t30\telements\tin\tthe \tperiodic\ttable. \t\tname\tthe\telement\twhich:  (a)\t\tis\t78%\tof\tclean,\tdry\tair\t\t   [1]  (b)\t\thas\tatoms\twith\tan\telectronic\tstructure\tof\t2,8,1\t \t...   [1]  (c)\t\tis\textracted\tfrom\thematite\t\t...   [1]  (d)\t\tforms\tan\toxide\twith\ta\tgiant\tcovalent\tstructure\t \t   [1]  (e)\t\tis\tthe\tgas\twith\tthe\tslowest\trate\tof\tdiffusion\tat\troom\t temperature  \t..   [1]  (f)\t\thas\tan\tanhydrous\tchloride\twhich\tturns\tpink\twhen\twater\tis\tadded  \t..   [1]  (g)\t\thas\taqueous\tions\twhich\tform\ta\twhite\tprecipitate\twhen\tadded\tto\taqueous\tsilver\tions  \t..   [1]  (h)\t\tforms\ta\tblue\thydroxide\twhich\tdissolves\tin\taqueous\t ammonia  \t [1]  (i)\t\tis\tadded\tto\tmolten\tiron\tto\tremove\timpurities\tin\tthe\t steel\tmaking\tprocess  \t..   [1]  (j)\t\tis\tused\tto\tgalvanise\tiron.\t \t.   [1] \t [total:\t10]",
            "3": "3 0620/42/f/m/22 \u00a9 ucles 2022 [turn over 2\t\ta\tstudent\tadds\texcess\tlarge\tpieces\tof\tmagnesium\t carbonate,\t mgco3,\tto\tdilute\thydrochloric\t acid,\t hcl,\tand\tmeasures\tthe\tvolume\tof\tcarbon\tdioxide\tgas,\tco2,\tgiven\toff.  (a)\t\tadd\tthe\tmissing\tstate\tsymbols\tto\tthe\tchemical\tequation\tfor\tthe\treaction. \t mgco3\t.\t\t+\t\t2hc l\t.\t\t\u2192\t\tmgcl 2(aq)\t\t+\t\th2o\t.\t\t+\t\tco2\t.\t [1]  (b)\t\tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t of\tthe\tions\tin\t magnesium\tchloride. \t\tthe\tinner\tshells\thave\tbeen\tdrawn. \t\tgive\tthe\tcharges\ton\tthe\tions. ... mg... cl ... cl \t [3]  (c)\t\tcomplete\t the\tdot-and-cross\t diagram\tto\tshow\tthe\telectron\tarrangement\t in\ta\tmolecule\t of\t carbon\tdioxide. \t\tshow\touter\tshell\telectrons\tonly. c o o \t [2]",
            "4": "4 0620/42/f/m/22 \u00a9 ucles 2022  (d)\t\tthe\tgraph\tshows\thow\tthe\tvolume\tof\tcarbon\tdioxide \tgas\tchanges\twith\ttime. 00volume of carbon dioxide gas time  (i)\t\tdescribe\thow\tthe\tgraph\tshows\tthat\tthe\trate\tof\tthis\treaction\tdecreases\tas\ttime\tincreases.  \t .  \t ...   [1]  (ii)\t\texplain,\tin\t terms\tof\tparticles,\twhy\tthe\trate\tof\tthis\treaction\tdecreases\tas\ttime\tincreases.  \t .  \t ... \t\t[2]  (iii)\t\tthe\tstudent\trepeats\tthe\texperiment\tusing\tpowdered\tmgco3\tinstead\tof\tlarge\tpieces. \t \tall\tother\tconditions\tstay\tthe\tsame.   on the grid,\t draw\tthe\tline\texpected\t when\tpowdered\t mgco3\tis\tused\tinstead\tof\tlarge\t pieces.\t [2]",
            "5": "5 0620/42/f/m/22 \u00a9 ucles 2022 [turn over  (e)\t\tdetermine\t the\tvolume\tof\tco2\tgas\tgiven\toff\twhen\texcess\tmgco3\tis\tadded\tto\t25.0\tcm3 of  0.400\tmol\t/\tdm3\thcl\tat\troom\ttemperature\tand\tpressure. mgco3\t\t+\t\t2hcl  \u2192\t\tmgcl 2\t\t+\t\th2o\t\t+\t\tco2 \t\tuse\tthe\tfollowing\tsteps.  \u25cf\tcalculate\tthe\tnumber\tof\tmoles\tof\thc l\tin\t25.0\tcm3\tof\t0.400\tmol\t/\tdm3\tof\tacid. \t ..\tmol  \u25cf\tdetermine\tthe\tnumber\tof\tmoles\tof\tco2\tgas\tgiven\toff. \t ..\tmol  \u25cf\tcalculate\tthe\tvolume\tof\tco2\tgas\tgiven\toff\tin\tcm3. \t ..\tcm3 \t [3] \t [total:\t14]",
            "6": "6 0620/42/f/m/22 \u00a9 ucles 2022 3\t\tnitrogen\tdioxide,\tno2,\tis\tan\tatmospheric\tpollutant\tand\tis\tformed\tin\tcar\tengines.  (a)\t\texplain\thow\tnitrogen\tdioxide\tis\tformed\tin\tcar\tengines.  \t  \t.. \t\t[2]  (b)\t\tnitrogen\tdioxide\tcauses\trespiratory\tproblems.   state one other\tadverse\teffect\tof\tnitrogen\tdioxide.  \t..   [1]  (c)\t\tnitrogen\tdioxide\temissions\t can\tbe\treduced\tby\tadding\tan\taqueous\tsolution\tof\turea,\t(nh2)2co,\t to\tcar\texhaust\tgases. \t\tthe\theat\tof\tthe\texhaust\tgases\tbreaks\tdown\tthe\turea\tinto\tsimpler\tsubstances.  (i)\t\tname\tthe\ttype\tof\treaction\twhich\toccurs\twhen\ta\tsubstance\t is\theated\tand\tbreaks\tdown\tinto\t simpler\tsubstances.  \t ...   [1]  (ii)\t\tone\tmolecule\t of\turea\tbreaks\tdown\tto\tform\tone\tmolecule\t of\tammonia\t and\tone\tother\t molecule. \t \tcomplete\t the\tchemical\tequation\tto\tshow\tthe\tformula\tof\tthe\tother\tmolecule\tformed\tin\tthis\t reaction.  (nh2)2co\t\t\u2192  nh3\t\t+\t\t..\t [1]  (iii)\t\tstate\tthe\ttest\tfor\tammonia.  test \t .. \t observations\t \t ... \t [2]  (d)\t\tthe\tammonia\tformed\treacts\twith\tnitrogen\tdioxide\tto \tform\tnitrogen\tand\twater.  (i)\t\tbalance\tthe \tequation\tfor\tthis\treaction. \t ..no2\t\t+\t\t..nh3  \u2192\t\t..n2\t\t+\t\t12h2o\t [2]  (ii)\t\tstate\thow\tthe\tequation\tshows\tthat\tthe\tnitrogen\tin\tnitrogen\tdioxide\tis\treduced.  \t ...   [1]",
            "7": "7 0620/42/f/m/22 \u00a9 ucles 2022 [turn over  (iii)\t\tthis\treaction\tis\ta\tredox\treaction. \t \tstate\tthe\tmeaning\tof\tthe\tterm\tredox.  \t ...   [1]  (e)\t\t135\tmoles\tof\turea,\t(nh2)2co,\tis\tstored\tin\tthe\ttank\tof\ta\tcar. \t\tcalculate\tthe\tmass,\tin\tkg,\tof\tthe\tstored\t(nh2)2co. \t mass\tof\t(nh2)2co\t=\t..\tkg \t [2]  (f)\t\tanother\toxide\tof\tnitrogen\tformed\tin\tcar\tengines\tis\tnitrogen\tmonoxide,\t no.\ta\tcatalytic\tconverter\t removes\tno\tby\treacting\tit\twith\ta\tgas\tformed\tby\tincomplete\t combustion\t of\tthe\tfuel.\ttwo\t non-toxic\tgases\tare\tformed.  (i)\t\tname\tthe\tgas\tformed\tby\tincomplete\tcombustion\tof\tthe\tfuel.  \t ...   [1]  (ii)\t\tname\tthe\ttwo\tnon-toxic\tgases\tformed. \t ... \tand\t\t   [1] \t [total:\t15]",
            "8": "8 0620/42/f/m/22 \u00a9 ucles 2022 4\t\tthis\tquestion\tis\tabout\tchemical\treactions\tand\telectricity.  (a)\t\tthe\tdiagram\tshows\tthe\tapparatus\tused\tin\tthe\tproduction\tof\telectrical\tenergy\tin\ta\tsimple\tcell. vvoltmeter iron electrod e zinc electrod e electrolyte \t\tthe\tzinc\telectrode\tdissolves\tin\tthe\telectrolyte\tforming\tzn2+(aq)\tions.  (i)\t\tdraw\tan\tarrow\ton\tthe\tdiagram\tto\tshow\tthe\tdirection\tof\telectron\tflow.\t [1]  (ii)\t\twrite\tthe\tionic\thalf-equation\t for\tthe\treaction\tthat\toccurs\twhen\tthe\tzinc\telectrode\tdissolves.  \t ... \t\t[2]  (b)\t\tthe\treading\ton\tthe\tvoltmeter\t can\tbe\tincreased\t if\teither\tzinc\tor\tiron\tis\treplaced\tby\tanother\t metal.  (i)\t\tname\ta\tmetal\tthat\tcan\treplace\tzinc\tand \tincrease\tthe\treading\ton\tthe\tvoltmeter.  \t ...   [1]  (ii)\t\tname\ta\tmetal\tthat\tcan\treplace\tiron\tand \tincrease\tthe\treading\ton\tthe\tvoltmeter.  \t ...   [1]  (c)\t\tfuel\tcells\tare\tused\tto\tgenerate\telectricity.  (i)\t\tname\tthe\treactants\tin\ta\tfuel\tcell.  \t ...   [1]  (ii)\t\tname\tthe\twaste\tproduct\tof\ta\tfuel\tcell.  \t ...   [1]",
            "9": "9 0620/42/f/m/22 \u00a9 ucles 2022 [turn over  (d)\t\telectricity\tcan\tbe\tused\tto\tbreak\tdown\taqueous\tor\tmolten\tionic\tcompounds.  (i)\t\tname\tthe\tprocess\twhich\tuses\telectricity\tto\tbreak\tdown\taqueous\tor\tmolten\tionic\tcompounds.  \t ...   [1]  (ii)\t\texplain\twhy\tthe\tionic\tcompound\tneeds\t to\tbe\taqueous\tor\tmolten.  \t ...   [1]  (e)\t\tbrine\tis\tconcentrated\taqueous\tsodium\tchloride.  (i)\t\tname\tthree\tsubstances\twhich\tare\tmanufactured\tby\tpassing\telectricity\tthrough\tbrine.  1 \t .. \t 2\t\t .. \t 3\t\t .. \t [3]  (ii)\t\tname\ta\tdifferent\tsubstance\t formed\twhen\tmolten\tsodium\tchloride\tis\tused\tinstead\tof\t concentrated\taqueous\tsodium\tchloride.  \t ...   [1] \t [total:\t13]",
            "10": "10 0620/42/f/m/22 \u00a9 ucles 2022 5\t\tthis\tquestion\tis\tabout\talkanes\tand\talkenes.  (a)\t\tshort-chain\t alkanes\tand\talkenes\tcan\tbe\tformed\tfrom\tlong-chain\t alkanes\tin\ta\tchemical\treaction.  (i)\t\tname\tthe\ttype\tof\tchemical\treaction\twhich\tforms\tshort-chain\t alkanes\tand\talkenes\tfrom\t long-chain\talkanes.  \t ...   [1]  (ii)\t\tdecane\thas\t10\tcarbon\tatoms.\tit\tforms\tethane\tand\tethene\tas\tthe\tonly\tproducts\tin\tthis\ttype\t of\tchemical\treaction. \t \twrite\tthe\tchemical\tequation\tfor\tthis\treaction.  \t ... \t\t[3]  (b)\t\tethane\treacts\twith\tchlorine\tat\troom\ttemperature\t to\tform\tchloroethane,\t c2h5cl,\tand\tone\tother\t product.  (i)\t\tname\tthe\tother\tproduct\tformed.  \t ...   [1]  (ii)\t\tstate\tthe\tcondition\tneeded\tfor\tthis\treaction\tto\ttake\tplace.  \t ...   [1]  (c)\t\tethene\treacts\twith\tchlorine\tat\troom\ttemperature\tto\t form\tdichloroethane,\tc2h4cl 2. c2h4\t\t+\t\tc l 2  \u2192\t\tc2h4cl 2  (i)\t\tstate\twhy\tthis\tis\tan\taddition\treaction.  \t ...   [1]",
            "11": "11 0620/42/f/m/22 \u00a9 ucles 2022 [turn over  (ii)\t\tthe\tchemical\tequation\tfor\tthis\treaction\tcan\tbe\trepresented\tas\tshown. cl cl ch hch hcl cl cc +h hh h \t \tthe\tenergy\tchange\tfor\tthe\treaction\tis\t\u2013180\t kj\t/\tmol. \t \tuse\tthe\tbond\tenergies\tin\tthe\ttable\tto\tcalculate\tthe\tbond\tenergy\tof\ta\tc\u2013cl\tbond,\tin\tkj\t/\tmol. bond c\u2013hc=ccl\t\u2013c lc\u2013c bond\tenergy\tin\tkj\t /\tmol410610240350 \t \tuse\tthe\tfollowing\tsteps.  step 1\t\tcalculate\tthe\tenergy\tneeded\tto\tbreak\tbonds. \t energy\tneeded\tto\tbreak\tbonds\t=\t..\tkj  step 2\t\tuse\tyour\tanswer\tin\tstep 1\tand\tthe\tenergy\tchange\tfor\tthe\treaction\tto\tdetermine \t the\tenergy\treleased\twhen\tbonds\tare\tformed. \t energy\treleased\twhen\tbonds\tform\t=\t..\tkj  step 3\t\tuse\tyour\tanswer\tin\tstep 2\tand\tbond\tenergy\tvalues\tto\tdetermine\t the\tenergy\tof\t a\tc\u2013cl\tbond. \t bond\tenergy\tof\ta\tc\u2013c l\tbond\t=\t..\tkj\t /\tmol \t [4] \t [total:\t11]",
            "12": "12 0620/42/f/m/22 \u00a9 ucles 2022 6\t\tthe\tnames\tof\tfour\testers\tare\tlisted. methyl propanoate ethyl propanoate propyl propanoate butyl propanoate  (a)\t\testers\tare\ta\tfamily\tof\torganic\tcompounds\t with\tsimilar\tchemical\t properties.\t they\tcan\tbe\t represented\tby\tthe\tformula\tcnh2no2.  (i)\t\tstate\tthe\tname\tgiven\tto\ta\tfamily\tof\torganic\tcompounds\twith\tsimilar\tchemical\tproperties.  \t ...   [1]  (ii)\t\texplain\twhy\tmembers\t of\ta\tfamily\tof\torganic\tcompounds\t have\tsimilar\tchemical\tproperties.  \t ...   [1]  (iii)\t\tstate\tthe\tname\tgiven\tto\ta\tformula\tsuch\t as\tcnh2no2.  \t ...   [1]  (iv)\t\tdetermine\t the\tvalue\tof\t\u2018n\u2019 \tin\tbutyl\tpropanoate.  \t ...   [1]  (b)\t\tall\tfour\tof\tthe\testers\tin\tthe\tlist\tare\tliquids\tat\troom\ttemperature. \t\tname\tthe\ttechnique\tused\tto\tseparate\tethyl\tpropanoate\tfrom\ta\tmixture\tof\tthe\tfour\testers.  \t.. \t\t[2]  (c)\t\tall\tfour\testers\tcan\tbe\tmade\tby\treacting\tdifferent\talcohols\twith\tthe\tsame\tsubstance.  (i)\t\tname\tthis\tsubstance\tand\tdraw\tits\tstructure.\tshow\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds. \t name\t... \t structure \t [2]  (ii)\t\tname\tthe\talcohol\tused\tto\tmake\tmethyl\t propanoate.  \t ...   [1]",
            "13": "13 0620/42/f/m/22 \u00a9 ucles 2022 [turn over  (d)\t\tother\testers,\tnot\tin\tthe\tlist,\thave\tthe\tsame\tmolecular\tformula\tas\tpropyl\tpropanoate,\t but\tdifferent\t structures.  (i)\t\tstate\tthe\tterm\tused\tto\tdescribe\tsubstances\t with\tthe\tsame\tmolecular\t formula\tbut\tdifferent\t structures.  \t ...   [1]  (ii)\t\tname\ttwo\testers\twith\tthe\tsame\tmolecular\tformula\tas\tpropyl\tpropanoate.  1 \t .. \t 2\t\t .. \t [2]  (e)\t\tpolyesters\tcan\tbe\tmade\tfrom\tthe\ttwo\tdifferent\tmolecules\tshown. co h ando ho co ohh o  (i)\t\tcomplete\t the\tdiagram\tto\tshow\ta\tsection\tof\tthe\tpolyester\tmade\tfrom\tthese\ttwo\tmolecules.\t include\tall\tof\tthe\tatoms\tand\tall\tof\tthe\tbonds\tin\tthe\tlinkages.\t \t [3]  (ii)\t\tname\tthe\ttype\tof\tpolymerisation\tthat\ttakes\tplace\twhen\tthis\tpolymer\tforms.  \t ...   [1]  (iii)\t\tname\ta\tpolyester.  \t ...   [1] \t [total:\t17]",
            "14": "14 0620/42/f/m/22 \u00a9 ucles 2022blank page",
            "15": "15 0620/42/f/m/22 \u00a9 ucles 2022permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge.blank page",
            "16": "16 0620/42/f/m/22 \u00a9 ucles 2022 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_m22_qp_52.pdf": {
            "1": "*6396159486* chemistry  0620/52 paper 5 practical test february/march 2022  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib22 03_0620_52/2rp \u00a9 ucles 2022 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/52/f/m/22 \u00a9 ucles 2022 1  you are going to investigate the temperature change when anhydrous lithium chloride dissolves in  water.   read all of the instructions carefully before starting the experiments.   instructions   you are going to do six experiments.  (a)  experiment 1  \u25cf use a measuring cylinder to pour 30 cm3 of distilled water into a 100 cm3 beaker.  \u25cf use a thermometer to measure the initial temperature of the water. record the initial  temperature in the table.  \u25cf add the 1.0 g sample of anhydrous lithium chloride to the water in the beaker. at the same  time start a timer.  \u25cf continually stir the mixture in the beaker using the thermometer.  \u25cf measure the temperature reached by the mixture after 30 seconds. record the temperature  of the mixture in the table.  \u25cf calculate and record the temperature change in the table.  \u25cf empty and rinse the beaker with distilled water.   experiment 2  \u25cf repeat experiment 1 using the 1.5 g sample of anhydrous lithium chloride instead of the  1.0 g sample of anhydrous lithium chloride.   experiment 3  \u25cf repeat experiment 1 using the 2.0 g sample of anhydrous lithium chloride instead of the  1.0 g sample of anhydrous lithium chloride.   experiment 4  \u25cf repeat experiment 1 using the 2.5 g sample of anhydrous lithium chloride instead of the  1.0 g sample of anhydrous lithium chloride.   experiment 5  \u25cf repeat experiment 1 using the 3.0 g sample of anhydrous lithium chloride instead of the  1.0 g sample of anhydrous lithium chloride.   experiment 6  \u25cf repeat experiment 1 using the 4.0 g sample of anhydrous lithium chloride instead of the  1.0 g sample of anhydrous lithium chloride.",
            "3": "3 0620/52/f/m/22 \u00a9 ucles 2022 [turn over   complete the table.  experimentmass of anhydrous lithium chloride / ginitial temperature / \u00b0ctemperature after 30 seconds / \u00b0ctemperature  change / \u00b0c 1 1.0 2 1.5 3 2.0 4 2.5 5 3.0 6 4.0  [5]  (b)  complete a suitable scale on the y-axis and plot your results from experiments 1 to 6 on the  grid. \t\tdraw\ta\tstraight\tline\tof\tbest\tfit\tthrough\tyour\tpoints.\t the\tstraight\tline\tmust\tpass\tthrough\t(0,0). 00 0.5 1.0 1.5 2.0 mass of anhydrous lithium chloride  / gtemperature change  / /g113c 2.5 3.0 3.5 4.0  [5]",
            "4": "4 0620/52/f/m/22 \u00a9 ucles 2022  (c)  from your graph,\t deduce\tthe\ttemperature\t change\twhen\t3.2\tg\tof\tanhydrous\t lithium\tchloride\t is dissolved in 30 cm3 of distilled water.   show clearly on the grid  how you worked out your answer.  temperature change = .. \u00b0c  [2]  (d)  estimate the temperature change if experiment 6 is repeated using 60 cm3 of water instead of  30 cm3 of water. give a reason for your answer.      ..   [2]  (e)  suggest two changes that could be made to the apparatus to improve the accuracy of the  results. for each change explain why it improves the accuracy of the results.  change 1    explanation 1  .     change 2    explanation 2  .     [4] \t [total:\t18]",
            "5": "5 0620/52/f/m/22 \u00a9 ucles 2022 [turn over 2  you are provided with solution a and solid b. \t\tdo\tthe\tfollowing\ttests\ton\tthe\tsubstances,\trecording\tall\tof\tyour\tobservations\tat\teach\tstage.  tests on solution a  (a)\t\tcarry\tout\ta\tflame\ttest\ton\tsolution\t a.   record your observations.   ..   [1]   divide the remaining solution a into four approximately equal portions in one boiling tube and three  test-tubes.  (b)\t\tto\tthe\tfirst\tportion\tof\tsolution\t a in a boiling tube add aqueous ammonia dropwise until it is in  excess.   record your observations.         ..   [3]  (c)\t\tto\tthe\tsecond\tportion\tof\tsolution\t a add about 1 cm depth of dilute nitric acid followed by a few  drops of aqueous silver nitrate.   record your observations.      ..   [1]  (d)  add the third portion of solution a to the test-tube containing aqueous chlorine.   record your observations.      ..   [1]  (e)\t\tto\tthe\tfourth\tportion\tof\tsolution\t a add the magnesium ribbon.   record your observations.      ..   [1]  (f)  identify the three ions contained in solution a.         ..   [3]",
            "6": "6 0620/52/f/m/22 \u00a9 ucles 2022   tests on solid b   add about 15 cm3 of distilled water to the boiling tube containing solid b. replace the stopper in the  boiling tube and shake the boiling tube to dissolve as much solid b as possible and form solution b.    filter the mixture formed and collect solution b\tas\tthe\tfiltrate.\tdivide\tsolution\t b into three  approximately equal portions in three test-tubes.  (g)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tb. \t ph\t=\t..\t\t[1]  (h)\t\tto\tthe\tsecond\tportion\tof\tsolution\t b add aqueous sodium hydroxide dropwise and then in  excess.   record your observations.      ..   [2]  (i)\t\tto\tthe\tthird\tportion\tof\tsolution\t b add aqueous ammonia dropwise and then in excess.   record your observations.      ..   [1]  (j)  identify solid b.      ..   [2] \t [total:\t16]",
            "7": "7 0620/52/f/m/22 \u00a9 ucles 2022 [turn over 3\t\tfizzy\tdrinks\tcontain\tcarbon\tdioxide\tgas\tdissolved\t in\ta\tliquid.\tthe\tcarbon\tdioxide\tgas\tcan\tbe\t removed\tfrom\tthe\tfizzy\tdrink\tby\theating. \t\tplan\tan\tinvestigation\tto\tfind\tthe\tvolume\tof\tcarbon \tdioxide\tgas\tin\t1\t dm3\tof\ta\tfizzy\tdrink.   include in your answer how you will calculate the volume of carbon dioxide gas dissolved in 1 dm3  of\ta\tfizzy\tdrink. \t\tyou\tare\tprovided\twith\ta\tsmall\tsample\t(less\tthan\t1\tdm3)\tof\tthe\tfizzy\tdrink\tand\tcommon\tlaboratory\t apparatus. \t\t(1\tdm3 = 1000 cm3)   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "8": "8 0620/52/f/m/22 \u00a9 ucles 2022blank page",
            "9": "9 0620/52/f/m/22 \u00a9 ucles 2022blank page",
            "10": "10 0620/52/f/m/22 \u00a9 ucles 2022blank page",
            "11": "11 0620/52/f/m/22 \u00a9 ucles 2022notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/52/f/m/22 \u00a9 ucles 2022tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge."
        },
        "0620_m22_qp_62.pdf": {
            "1": "*0293365347* chemistry  0620/62 paper 6 alternative to practical february/march 2022  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib22 03_0620_62/4rp \u00a9 ucles 2022 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/62/f/m/22 \u00a9 ucles 2022 1  calcium carbonate reacts with dilute hydrochloric acid. the products of the reaction are  aqueous calcium chloride, water and carbon dioxide gas.   a student investigated the rate of the reaction between calcium carbonate and dilute hydrochloric  acid using the apparatus shown. 124.25  gflask calcium carbonatecotton wool dilute hydrochloric acid balanc e \t\tthe\tmass\tof\tthe\tflask\tand\tcontents\twas\trecorded \tevery\t30\tseconds. \t\twhen\tthe\treaction\tstopped\tthere\twere\tstill\tsmall\t pieces\tof\tcalcium\tcarbonate\tin\tthe\tflask.  (a)\t\tstate\twhat\thappens\tto\tthe\treading\ton\tthe\tbalance\tas\tthe\treaction\ttakes\tplace.   explain your answer.  reading on balance    explanation       [2]  (b)\t\tthere\tis\ta\tpiece\tof\tcotton\twool\tin\tthe\tneck\tof\tthe\tflask.  (i)  suggest why a bung is not\tused\tin\tthe\tneck\tof\tthe\tflask.   .   ...   [1]  (ii)\t\tsuggest\twhy\tcotton\twool\tis\tplaced\tin\tthe\tneck\tof\tthe\tflask\trather\tthan\tleaving\tthe\tflask\t open.   .   ...   [1]  (c)  state which reactant is in excess.   ..   [1]",
            "3": "3 0620/62/f/m/22 \u00a9 ucles 2022 [turn over  (d)\t\tdescribe\thow\tcrystals\tof\tcalcium\tchloride\tcan\tbe\tobtained\tfrom\tthe\tmixture\tleft\tin\tthe\tflask\t after the reaction has stopped.            .. \t\t[3]  [total: 8]",
            "4": "4 0620/62/f/m/22 \u00a9 ucles 2022 blank page",
            "5": "5 0620/62/f/m/22 \u00a9 ucles 2022 [turn over 2  a student investigated the temperature change when anhydrous lithium chloride dissolves in water.   the student did six experiments.  (a) experiment 1  \u25cf\tusing\ta\tmeasuring\tcylinder,\t30\t cm3\tof\tdistilled\twater\twas\tpoured\tinto\ta\t100\t cm3\tbeaker.  \u25cf the initial temperature of the water was measured using a thermometer.  \u25cf\t1.0\tg\tof\tanhydrous\t lithium\tchloride\twas\tadded\tto\tthe\twater\tin\tthe\tbeaker.\tat\tthe\tsame\ttime\t a timer was started.  \u25cf the water and lithium chloride mixture was continually stirred using a thermometer.  \u25cf\tthe\ttemperature\tof\tthe\tmixture\twas\tmeasured\tafter\t30\tseconds.  \u25cf\tthe\tbeaker\twas\trinsed\twith\tdistilled\twater.   experiment 2  \u25cf\texperiment\t 1\twas\trepeated\tusing\t1.5\tg\tof\tanhydrous \tlithium\tchloride\tinstead\tof\tthe\t1.0\tg\t of anhydrous lithium chloride.  experiment 3  \u25cf\texperiment\t 1\twas\trepeated\tusing\t2.0\tg\tof\tanhydrous \tlithium\tchloride\tinstead\tof\tthe\t1.0\tg\t of anhydrous lithium chloride.  experiment 4  \u25cf\texperiment\t 1\twas\trepeated\tusing\t2.5\tg\tof\tanhydrous \tlithium\tchloride\tinstead\tof\tthe\t1.0\tg\t of anhydrous lithium chloride.  experiment 5  \u25cf\texperiment\t 1\twas\trepeated\tusing\t3.0\tg\tof\tanhydrous \tlithium\tchloride\tinstead\tof\tthe\t1.0\tg\t of anhydrous lithium chloride.   experiment 6  \u25cf\texperiment\t 1\twas\trepeated\tusing\t4.0\tg\tof\tanhydrous \tlithium\tchloride\tinstead\tof\tthe\t1.0\tg\t of anhydrous lithium chloride.",
            "6": "6 0620/62/f/m/22 \u00a9 ucles 2022   use the thermometer diagrams to complete the table and calculate the temperature changes. experiment 1 1.0mass of anhydrous lithium chloride / ginitial thermometer diagramtemperature / /g113cthermometer diagramtemperature / /g113ctemperature change / /g113cafter 30 seconds 30 25 2030 25 20 2 1.530 25 2030 25 20 3 2.030 25 2035 30 25 35 30 254 2.530 25 20 5 3.030 25 2040 35 30 6 4.030 25 2040 35 30  [5]",
            "7": "7 0620/62/f/m/22 \u00a9 ucles 2022 [turn over  (b)  complete a suitable scale on the y-axis and plot the results from experiments 1 to 6 on the  grid. \t\tdraw\ta\tstraight\tline\tof\tbest\tfit\tthrough\tyour\tpoints.\t the\tstraight\tline\tmust\tpass\tthrough\t(0,0). 00 0.5 1.0 1.5 2.0 mass of anhydrous lithium chloride  / gtemperature change  / /g113c 2.5 3.0 3.5 4.0  [5]  (c)  from your graph,\t deduce\tthe\ttemperature\t change\twhen\t3.2\tg\tof\tanhydrous\t lithium\tchloride\t is\tdissolved\tin\t30\t cm3 of distilled water.   show clearly on the grid \thow\tyou\tworked\tout\tyour\tanswer.  temperature change = .. \u00b0c  [2]  (d)\t\testimate\tthe\ttemperature\t change\tif\texperiment\t 6\tis\trepeated\tusing\t60\tcm3 of water instead of  30\tcm3 of water. give a reason for your answer.         ..   [2]",
            "8": "8 0620/62/f/m/22 \u00a9 ucles 2022  (e)  suggest two changes that could be made to the apparatus to improve the accuracy of the  results. for each change explain why it improves the accuracy of the results.  change 1    explanation 1  .     change 2    explanation 2  .     [4]  [total: 18]",
            "9": "9 0620/62/f/m/22 \u00a9 ucles 2022 [turn over 3  solution a and solid b were analysed. solution a\twas\taqueous\tcopper( ii)\tbromide.   tests were done on each substance.   complete the expected observations.   tests on solution a   solution a was divided into three approximately equal portions in three test-tubes.  (a)\t\tthe\tend\tof\ta\tpiece\tof\twire\twas\tdipped\tinto\tthe\tfirst\tportion\tof\tsolution\t a. the end of the wire  was\tthen\tplaced\tat\tthe\tedge\tof\ta\troaring\tbunsen\tburner\tflame.  observations     [1]  (b)  to the second portion of solution a aqueous ammonia was added dropwise until in excess.  observations  ..      .. \t\t[3]  (c)  to the third portion of solution a about 1 cm depth of dilute nitric acid followed by a few drops  of aqueous silver nitrate were added.  observations  ..   ..   [1]",
            "10": "10 0620/62/f/m/22 \u00a9 ucles 2022  tests on solid b tests observations solid b was added to 15 cm3 of water in  a boiling tube. a bung was placed in the  boiling\ttube\tand\tit\twas\tshaken\tto\tdissolve\t solid b and form solution b. solution b was  divided into three approximately equal portions  in three test-tubes. test 1 the\tfirst\tportion\tof\tsolution\tb was tested using  universal indicator paper.the universal indicator paper turned blue test 2 to the second portion of solution b aqueous  sodium hydroxide was added dropwise and  then in excess.a white precipitate formed which remained when excess aqueous sodium hydroxide was added test 3 to the third portion of solution b aqueous  ammonia was added dropwise and then in  excess.the solution remained colourless  (d)  deduce the ph of solution b.  ph = ..  [1]  (e)  identify solid b.      ..   [2]  [total: 8]",
            "11": "11 0620/62/f/m/22 \u00a9 ucles 2022 [turn over 4\t\tfizzy\tdrinks\tcontain\tcarbon\tdioxide\tgas\tdissolved\t in\ta\tliquid.\tthe\tcarbon\tdioxide\tgas\tcan\tbe\t removed\tfrom\tthe\tfizzy\tdrink\tby\theating. \t\tplan\tan\tinvestigation\tto\tfind\tthe\tvolume\tof\tcarbon \tdioxide\tgas\tin\t1\t dm3\tof\ta\tfizzy\tdrink.   include in your answer how you will calculate the volume of carbon dioxide gas dissolved in 1 dm3  of\ta\tfizzy\tdrink. \t\tyou\tare\tprovided\twith\ta\tsmall\tsample\t(less\tthan\t1\tdm3)\tof\tthe\tfizzy\tdrink\tand\tcommon\tlaboratory\t apparatus. \t (1\tdm3\t=\t1000\tcm3)   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "12": "12 0620/62/f/m/22 \u00a9 ucles 2022blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge."
        },
        "0620_s22_qp_11.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib22 06_0620_11/rp   \u00a9 ucles 2022   [turn ove r   *7500261882*cambridge igcse\u2122       chemistry 0620/11     paper 1 multiple choice (core)  may/june 2022     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2022 0620/11/m/j/22  1 diagrams of the three states of matter for carbon dioxide are shown.    123     which two diagrams show the states of matter before and after t he sublimation of  carbon dioxide?  a 2 to 1 b 2 to 3 c 3 to 1 d 3 to 2    2 a student measures the time taken for 2.0  g of magnesium to dissolve in 50  cm3 of dilute  sulfuric acid.    which apparatus is essential to complete the experiment?    1 stop-clock  2 measuring cylinder  3 thermometer  4 balance    a 1, 2 and 4 b 1 and 2 only c 1 and 4 only d 2, 3 and 4      3 which method is used to separate a mixture of the following liq uids?    liquid boiling point  / \uf0b0c  methanol 64.5  ethanol 78.5  propan-1-ol 97.2  butan-1-ol 117.0    a crystallisation  b evaporation  c filtration  d fractional distillation    ",
            "3": "3     \u00a9 ucles 2022 0620/11/m/j/22 [turn over  4 which substance should be pure for the intended use?  a a drug for curing disease  b limestone for iron extraction  c petroleum for fractional distillation  d water for washing a car      5 which row identifies an alloy, a pure metal and a non-metal?     alloy pure metal non-metal  a brass carbon copper  b brass copper carbon  c copper brass carbon  d copper carbon brass      6 information about the structures of three atoms, x, y and z, i s shown.    atom proton  number nucleon  number  x 1 1  y 1 2  z 1 3    which statements about atoms x, y and z are correct?    1 they are isotopes of the same element.  2 they contain the same number of electrons. 3 they contain the same number of neutrons.  4 they contain one occupied electron shell.    a 1, 2 and 4 b 1 and 2 only c 3 and 4 d 3  o n l y      7 what happens to an atom when it becomes an ion with a charge o f +1?  a it gains an electron.  b it gains a proton.  c it loses an electron.  d it loses a proton.    ",
            "4": "4  \u00a9 ucles 2022 0620/11/m/j/22  8 the relative atomic mass, ar, of an element is determined by comparing the mass of one atom  of  the element with the mass of one atom of element q.    what is q?  a carbon  b chlorine  c hydrogen  d oxygen     9 which equation for the decomposition of calcium nitrate is corr ect?  a c a ( n o 3)2  \uf0ae  cao  +  no 2  +  o 2  b c a ( n o 3)2  \uf0ae  cao  +  2no 2  +  o 2  c 2 c a ( n o 3)2  \uf0ae  2cao  +  2no 2  +  o 2  d 2 c a ( n o 3)2  \uf0ae  2cao  +  4no 2  +  o 2     10 the diagram shows the electrolysis of concentrated hydrochlori c acid and concentrated aqueous  sodium chloride using carbon electrodes.    +\u2013 +\u2013 electrode 2 electrode 1 concentrated hydrochloric acidelectrode 4 electrode 3 concentrated aqueous sodium chloride    at which electrodes is hydrogen produced?  a electrode 1 only  b electrodes 1 and 3  c electrode 2 only  d electrodes 2 and 4    ",
            "5": "5     \u00a9 ucles 2022 0620/11/m/j/22 [turn over  11 overhead power cables made from (steel-cored) aluminium are us ed to carry electricity over long  distances.    which property of (steel-cored) a luminium makes it suitable for  use in power cables?  a aluminium has a low density.  b aluminium has low strength.  c steel is a good conductor of heat.  d steel is resistant to corrosion.    12 which row identifies a chemical change and a physical change?     chemical change physical change  a boiling ethanol burning ethanol  b burning ethanol evaporating ethanol  c dissolving ethanol in water burning ethanol  d evaporating ethanol dissolving ethanol in water     13 the equation for the reaction when hydrogen is used as a fuel is shown.    2h 2  +  o 2  \uf0ae  2h 2o    which statement about this reaction is correct?  a energy is given out so the temperature of the surroundings decr eases.  b energy is taken in so the temperature of the surroundings incre ases.   c the reaction is endothermic so the temperature of the surroundi ngs decreases.  d the reaction is exothermic so th e temperature of the surroundin gs increases.    14 which fuels release carbon dioxide when burned?    1 gasoline  2 hydrogen 3 methane    a 1 and 2 b 1 and 3 c 2 and 3 d 3  o n l y      ",
            "6": "6  \u00a9 ucles 2022 0620/11/m/j/22  15 water is added to anhydrous copper( ii) sulfate.    what happens during the reaction?  a the copper( ii) sulfate turns blue and the solution formed gets colder.  b the copper( ii) sulfate turns blue and the solution formed gets hotter.  c the copper( ii) sulfate turns white and the solution formed gets colder.  d the copper( ii) sulfate turns white and the solution formed gets hotter.     16 excess magnesium ribbon is reacted with a fixed volume of hydr ochloric acid and the volume of  gas given off over time is measured.    the results of two different experiments are shown.    volume of gas given off time00reaction 1 reaction 2     which statement explains the differences between the results of  the two experiments?  a reaction 1 uses a catalyst.  b the acid used is twice as concentrated in reaction 1.  c the magnesium ribbon is in smaller pieces in reaction 2.  d the temperature is higher in reaction 2.      17 which products are formed when magnesium hydroxide reacts with  hydrochloric acid?  a magnesium chloride, carbon dioxide and water  b magnesium chloride, hydrogen and water  c magnesium chloride and hydrogen only  d magnesium chloride and water only     ",
            "7": "7     \u00a9 ucles 2022 0620/11/m/j/22 [turn over  18 the oxides of two elements, x and y, are separately dissolved in water and the ph of each  solution tested.    oxide tested ph of solution  x 1  y 13    which information about x and y is correct?     oxide is  acidic oxide is  basic metal non-metal  a x y x y  b x y y x  c y x x y  d y x y x      19 an acid is neutralised by adding an excess of an insoluble soli d base.    a soluble salt is formed.    how is the pure salt obtained from the reaction mixture?  a crystallisation \uf0ae evaporation \uf0ae filtration  b evaporation \uf0ae crystallisation \uf0ae filtration  c filtration \uf0ae crystallisation \uf0ae evaporation  d filtration \uf0ae evaporation \uf0ae crystallisation    ",
            "8": "8  \u00a9 ucles 2022 0620/11/m/j/22  20 three separate samples of an aqueous compound t are tested.    the results of the tests are shown.    test observation  acidify with dilute nitric acid,  then add aqueous barium nitrate white precipitate    add aqueous ammonia white precipitate, soluble in excess  add aqueous sodium hydroxide white precipitate, soluble in exce ss    what is t?  a aluminium chloride  b aluminium sulfate  c zinc chloride  d zinc sulfate    21 part of the periodic table is shown.    which element is a metal?    a b c d      22 the elements sodium to argon form period 3 of the periodic tabl e.    which row describes the trend across period 3 from left to righ t?     number of  outer-shell electrons metallic  character group  number  a decreases decreases decreases  b decreases increases decreases  c increases decreases increases  d increases increases increases     ",
            "9": "9     \u00a9 ucles 2022 0620/11/m/j/22 [turn over  23 lithium, sodium and potassium are elements in group i of the p eriodic table.    which statement about these elements is correct?  a lithium has the highest melting point and the lowest density.  b lithium has the highest density and the most violent reaction w ith water.  c potassium has the highest melting point and the highest density .  d potassium has the lowest melting  point and the least violent re action with water.     24 which statement describes a transition element?  a it can act as a catalyst and som e of its compounds can also ac t as catalysts.  b it forms white compounds with sulfur, oxygen, chlorine and bro mine.  c it has a low density and a piece of it will float on water.  d it is a very poor conductor of electricity.    25 which diagram represents the arrangement of the outer-shell el ectrons of a noble gas?    a b cd       26 which statements about the general properties of metals are co rrect?    1 they are good conductors of heat and electricity.  2 they have low melting points. 3 they react with dilute acids to form a salt and water. 4 they react with oxygen to form basic oxides.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    ",
            "10": "10  \u00a9 ucles 2022 0620/11/m/j/22  27 reactions of three metals and their oxides are shown.    metal add dilute  hydrochloric acid  to metal heat  metal oxide  with carbon   1 \u0016 \u0016 k e y   2 \u0016 \u001a \u0016 = reacts  3 \u001a \u0016 \u001a = does not react    what is the order of reactivity of these metals, from most reac tive to least reactive?  a 1  \uf0ae 2 \uf0ae 3 b 1  \uf0ae 3 \uf0ae 2 c 2  \uf0ae 1 \uf0ae 3 d 2  \uf0ae 3 \uf0ae 1     28 which uses of the metals shown are correct?     aluminium stainless steel  a aircraft bodies car bodies  b car bodies aircraft bodies  c chemical plant food containers  d food containers cutlery     29 which statement about the reactions in the blast furnace is cor rect?  a carbon reacts with oxygen and heats the furnace.  b carbon monoxide removes the silicon dioxide impurity forming s lag.  c iron( iii) oxide is oxidised to iron.  d limestone reduces iron( iii) oxide to iron.     30 iron rusts when exposed to air.    which two substances in air cause iron to rust?  a carbon dioxide and oxygen  b nitrogen and oxygen  c oxygen and water  d carbon dioxide and water    ",
            "11": "11     \u00a9 ucles 2022 0620/11/m/j/22 [turn over  31 fertilisers are used to provide three of the elements needed fo r plant growth.    which two compounds would give a fertiliser containing all thre e of these elements?  a ca(no 3)2 and (nh 4)2so 4  b ca(no 3)2 and (nh 4)3po 4  c kno 3 and (nh 4)2so 4  d kno 3 and (nh 4)3po 4     32 which process produces methane?  a combustion of hydrocarbons  b decomposition of vegetation  c respiration  d reaction between hydrochloric acid and calcium carbonate    33 which statements about sulfur dioxide are correct?    1 sulfur dioxide decolourises acidified potassium manganate( vii).  2 sulfur dioxide forms when acids react with carbonates.  3 sulfur dioxide is used as a bleach.  4 sulfur dioxide is used to treat acidic soil.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      34 what are the products when limestone (calcium carbonate) is he ated strongly?  a calcium hydroxide and carbon dioxide  b calcium hydroxide and carbon monoxide  c calcium oxide and carbon dioxide  d calcium oxide and carbon monoxide      35 in which lists are the compounds in the same homologous series?     1 ch 4, c2h4, c3h8  2 ch 3oh, c 2h5oh, c 3h7oh  3 ch 3co 2h, ch 3ch 2oh, ch 3ch 2ch 2oh    a 1 and 2 b 1 and 3 c 2  o n l y  d 3  o n l y     ",
            "12": "12  \u00a9 ucles 2022 0620/11/m/j/22  36 which row about aqueous ethanoic acid and dilute hydrochloric a cid is correct?     both contain  carbon both contain  hydrogen both react  with carbonates   a \u0016 \u001a \u0016 k e y   b \u0016 \u0016 \u001a \u0016 = yes  c \u001a \u0016 \u0016 \u001a = no  d \u001a \u001a \u001a      37 some properties of colourless liquid l are listed.    \u25cf it boils at 65  \uf0b0c.  \u25cf when added to water, two layers form which do not mix.  \u25cf it does not react with sodium carbonate. \u25cf it has no effect on bromine water.    what is l?  a ethanol  b hexane  c hexene  d ethanoic acid    38 a molecule of compound p contains two carbon atoms and four hy drogen atoms.    which row represents p?     name of  compound m r reacts with  aqueous bromine  a ethane 30 \u001a  b ethene 16 \u0016  c ethene 28 \u0016  d ethene 28 \u001a     ",
            "13": "13     \u00a9 ucles 2022 0620/11/m/j/22  39 the equation representing the reaction of a hydrocarbon with w ater is shown.    c a t a l y s t   c xhy  +  h 2o    cxh5oh    what are the values of x and y?     x  y   a 1 4  b 1 6  c 2 4  d 2 6      40 many molecules of j join together in reaction r to form a long  chain molecule k.    k is the only product.    which row describes molecule j, reaction r and molecule k?     molecule j reaction r molecule k  a polymer addition monomer  b monomer addition polymer  c polymer cracking monomer  d monomer cracking polymer   ",
            "14": "14  \u00a9 ucles 2022 0620/11/m/j/22  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of cambrid ge assessment. cambridge assessment is the brand name of the un iversity of cambridge  local examinations syndicate (ucles), which is a department of the university of cambridge.    \u00a9 ucles 2022 0620/11/m/j/22  blank page  ",
            "16": "16  \u00a9 ucles 2022 0620/11/m/j/22   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s22_qp_12.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib22 06_0620_12/2rp   \u00a9 ucles 2022   [turn ove r   *7035866286 *cambridge igcse\u2122       chemistry 0620/12     paper 1 multiple choice (core)  may/june 2022     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2022 0620/12/m/j/22  1 substances change state when their temperature is changed.    which changes of state take place when the temperature of a sub stance is lowered?    1 boiling  2 condensation 3 freezing 4 melting    a 1 and 4 b 2, 3 and 4 c 2 and 3 only d 3  o n l y      2 a student measures the time taken for 2.0  g of magnesium to dissolve in 50  cm3 of dilute  sulfuric acid.    which apparatus is essential to complete the experiment?    1 stop-clock  2 measuring cylinder 3 thermometer  4 balance    a 1, 2 and 4 b 1 and 2 only c 1 and 4 only d 2, 3 and 4    3 which method is used to separate a mixture of the following liq uids?    liquid boiling point  / \uf0b0c  methanol 64.5  ethanol 78.5  propan-1-ol 97.2  butan-1-ol 117.0    a crystallisation  b evaporation  c filtration  d fractional distillation    ",
            "3": "3     \u00a9 ucles 2022 0620/12/m/j/22 [turn over  4 x and y are two different elements.    x and y have the same number of nucleons.    which statement about x and y is correct?  a they have the same physical properties.  b their atoms have the same number of electrons.  c they are in different groups of the periodic table.  d they have different relative masses.     5 which row identifies an alloy, a pure metal and a non-metal?     alloy pure metal non-metal  a brass carbon copper  b brass copper carbon  c copper brass carbon  d copper carbon brass      6 which statement about ions and ionic bonding is correct?  a caesium atoms gain electrons to form negatively charged caesiu m ions.  b ionic bonding involves sharing of pairs of electrons.  c potassium ions and chloride ions have the same number of outer -shell electrons.  d sodium ions have an equal number of protons and electrons.    7 which dot-and-cross diagram shows the arrangement of outer she ll electrons in a molecule of  hydrogen chloride?    ha cl hb cl hc cl cl hd       8 which statement explains why graphite can be used as a lubrica nt?  a all of the atoms in graphite are carbon.  b each carbon atom forms three bonds.  c graphite has a macromolecular structure.  d the layers in graphite can slide over each other.   ",
            "4": "4  \u00a9 ucles 2022 0620/12/m/j/22  9 a compound of element x has the formula x 2o and a relative formula mass of 144.    what is element x?  a copper, cu  b gadolinium, gd  c sulfur, s  d tellurium, te    10 the diagram shows the electrolysis of concentrated hydrochlori c acid and concentrated aqueous  sodium chloride using carbon electrodes.    +\u2013 +\u2013 electrode 2 electrode 1 concentrated hydrochloric acidelectrode 4 electrode 3 concentrated aqueous sodium chloride    at which electrodes is hydrogen produced?  a electrode 1 only  b electrodes 1 and 3  c electrode 2 only  d electrodes 2 and 4    11 which type of reaction occurs when calcium carbonate is heated at a high temperature to  produce calcium oxide and carbon dioxide?  a combustion  b endothermic  c oxidation  d reduction    ",
            "5": "5     \u00a9 ucles 2022 0620/12/m/j/22 [turn over  12 which row identifies a chemical change and a physical change?     chemical change physical change  a boiling ethanol burning ethanol  b burning ethanol evaporating ethanol  c dissolving ethanol in water burning ethanol  d evaporating ethanol dissolving ethanol in water      13 which statement about rate of reaction is correct?  a catalysts increase the time for the reaction to be completed.  b decreasing particle size increases the rate of reaction.  c decreasing temperature increases the rate of reaction.  d rate of reaction decreases as the concentration increases.      14 some common household substances are tested with litmus and met hyl orange.    household  substance colour of  litmus colour of  methyl orange  bicarbonate of soda blue yellow  lemonade red red  milk red red  milk of magnesia blue yellow  washing powder blue yellow  vinegar red red    which statement is correct?  a lemonade, milk and bicarbonate of soda are all acidic.  b milk of magnesia can neutralise washing powder.  c milk of magnesia, washing powder and vinegar are all bases.  d vinegar can neutralise bicarbonate of soda.    ",
            "6": "6  \u00a9 ucles 2022 0620/12/m/j/22  15 water is added to anhydrous copper( ii) sulfate.    what happens during the reaction?  a the copper( ii) sulfate turns blue and the solution formed gets colder.  b the copper( ii) sulfate turns blue and the solution formed gets hotter.  c the copper( ii) sulfate turns white and the solution formed gets colder.  d the copper( ii) sulfate turns white and the solution formed gets hotter.      16 in which equation is carbon both oxidised and reduced?  a c  +  o 2  \uf0ae  co 2  b co 2  +  c  \uf0ae  2co  c 3co  +  fe 2o3  \uf0ae  3co 2  +  2fe  d 2co  +  o 2  \uf0ae  2co 2      17 aqueous solutions containing copper( ii) ions can be identified using flame tests and by adding  aqueous sodium hydroxide.    which row describes what is observed in these tests?     flame test aqueous sodium hydroxide  a blue-green flame light blue precipitate  b blue-green flame green precipitate  c lilac flame light blue precipitate  d lilac flame green precipitate     ",
            "7": "7     \u00a9 ucles 2022 0620/12/m/j/22 [turn over  18 the oxides of two elements, x and y, are separately dissolved in water and the ph of each  solution tested.    oxide tested ph of solution  x 1  y 13    which information about x and y is correct?     oxide is  acidic oxide is  basic metal non-metal  a x y x y  b x y y x  c y x x y  d y x y x      19 an acid is neutralised by adding an excess of an insoluble soli d base.    a soluble salt is formed.    how is the pure salt obtained from the reaction mixture?  a crystallisation \uf0ae evaporation \uf0ae filtration  b evaporation \uf0ae crystallisation \uf0ae filtration  c filtration \uf0ae crystallisation \uf0ae evaporation  d filtration \uf0ae evaporation \uf0ae crystallisation    20 some statements about gas g are listed.    g is monoatomic.  g is found in clean, dry air. g is used in lamps.    which element is g?  a a r g o n   b helium  c nitrogen  d oxygen    ",
            "8": "8  \u00a9 ucles 2022 0620/12/m/j/22  21 part of the periodic table is shown.    which element is a metal?    a b c d      22 the elements sodium to argon form period 3 of the periodic tabl e.    which row describes the trend across period 3 from left to righ t?     number of  outer-shell electrons metallic  character group  number  a decreases decreases decreases  b decreases increases decreases  c increases decreases increases  d increases increases increases     23 some properties of element e are listed.    it has a high density.  it has a high melting point.    what is e?  a aluminium  b b r o m i n e   c iron  d lithium    ",
            "9": "9     \u00a9 ucles 2022 0620/12/m/j/22 [turn over  24 lithium, sodium and potassium are elements in group i of the p eriodic table.    chlorine, bromine and iodine are elements in group vii of the p eriodic table.    which row identifies the least  dense of these elements in each group?     group i group vii  a lithium chlorine  b lithium iodine  c potassium chlorine  d potassium iodine     25 the reactions of metals p, q, r and s are shown.    metal reaction  with water reaction with  hydrochloric acid reduction of the  metal oxide with carbon  p no reaction no reaction reduced  q slow vigorous no reaction  r vigorous vigorous no reaction  s very slow vigorous reduced    what is the order of reactivity of the metals?     least  reactive  most  reactive  a p s q r  b p q s r  c r s q p  d r q s p      26 iron is extracted from hematite in the blast furnace at a temp erature of about 1550  \uf0b0c.    which equation shows the main reaction that increases the tempe rature in the furnace?  a c a c o 3  \uf0ae  cao  +  co 2  b c  +  o 2  \uf0ae  co 2  c c o 2  +  c  \uf0ae  2co  d f e 2o3  +  3co  \uf0ae  2fe  +  3co 2     ",
            "10": "10  \u00a9 ucles 2022 0620/12/m/j/22  27 which diagram represents the arrangement of atoms in an alloy?     abcd      28 which uses of the metals shown are correct?     aluminium stainless steel  a aircraft bodies car bodies  b car bodies aircraft bodies  c chemical plant food containers  d food containers cutlery     29 which row identifies a substance present in clean air and a sub stance that is a pollutant in air?     present in clean air pollutant in air  a oxides of nitrogen nitrogen  b carbon dioxide sulfur dioxide  c carbon monoxide lead compounds  d nitrogen argon      30 which property of sulfur dioxide explains why it is used as a food preservative?  a acidic oxide  b bleach  c kills bacteria  d pungent smell     ",
            "11": "11     \u00a9 ucles 2022 0620/12/m/j/22 [turn over  31 fertilisers are used to provide three of the elements needed fo r plant growth.    which two compounds would give a fertiliser containing all thre e of these elements?  a ca(no 3)2 and (nh 4)2so 4  b ca(no 3)2 and (nh 4)3po 4  c kno 3 and (nh 4)2so 4  d kno 3 and (nh 4)3po 4    32 compound j is an unsaturated carboxylic acid.    which bonds are present in a molecule of j?     c=c c=o o\u2013h   a \u0016 \u0016 \u0016 k e y   b \u001a \u0016 \u0016 \u0016 = yes  c \u0016 \u001a \u001a \u001a = no  d \u001a \u0016 \u001a      33 petroleum is separated into useful fractions by fractional dis tillation.    which fraction is used as a fuel for jet aeroplanes?  a fuel oil  b gasoline  c naphtha  d kerosene  / paraffin      34 what are the products when limestone (calcium carbonate) is he ated strongly?  a calcium hydroxide and carbon dioxide  b calcium hydroxide and carbon monoxide  c calcium oxide and carbon dioxide  d calcium oxide and carbon monoxide     ",
            "12": "12  \u00a9 ucles 2022 0620/12/m/j/22  35 ethene reacts with substance x to form ethanol.    what is x?  a ethanoic acid  b glucose  c hydrogen  d steam     36 what is the equation for the complete combustion of methane?  a c h 4  +  4o 2  \uf0ae  co 2  +  2h 2o  b 2 c h 4  +  3o 2  \uf0ae  2co  +  4h 2o  c c h 4  +  2o 2  \uf0ae  co 2  +  2h 2o  d c 2h6  +  3o 2  \uf0ae  2co 2  +  3h 2o     37 alkenes can be produced by cracking large hydrocarbon molecules  to form smaller hydrocarbon  molecules.    which equations represent possible reactions when tetradecane, c 14h30, is cracked?    1 c 14h30  \uf0ae  c2h6  +  c 3h6  +  c 4h8  +  c 5h10  2 c 14h30  \uf0ae  h2  +  c 2h4  +  c 3h6  +  c 4h8  +  c 5h10  3 c 14h30  \uf0ae  c2h6  +  4c 3h6  4 c 14h30  \uf0ae  c2h6  +  c 3h8  +  c 9h18    a 1 only b 1 and 4 c 1, 2 and 3 d 3 and 4    ",
            "13": "13     \u00a9 ucles 2022 0620/12/m/j/22  38 the products formed by burning substance j are passed through the apparatus shown.    iceproducts of burning j white precipitateforms in limewate r water collects    what is substance j?  a carbon monoxide  b ethanol  c hydrogen  d s u l f u r     39 which statements about ethanoic acid are correct?    1 aqueous ethanoic acid reacts with magnesium to form magnesium  ethanoate.  2 carbon dioxide is formed when aqueous ethanoic acid reacts wi th  sodium carbonate.  3 hydrogen is formed when aqueous ethanoic acid reacts with sod ium hydroxide.  4 ethanoic acid turns red litmus paper blue.    a 1 and 2 b 1 and 3 c 2 and 3 d 2 and 4     40 which statement about polymerisation is correct?  a large monomer molecules join to form small polymer molecules.  b large polymer molecules join to form small monomer molecules.  c small monomer molecules join to form large polymer molecules.  d small polymer molecules join to form large monomer molecules.   ",
            "14": "14  \u00a9 ucles 2022 0620/12/m/j/22  blank page",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of cambrid ge assessment. cambridge assessment is the brand name of the un iversity of cambridge  local examinations syndicate (ucles), which is a department of the university of cambridge.    \u00a9 ucles 2022 0620/12/m/j/22  blank page  ",
            "16": "16  \u00a9 ucles 2022 0620/12/m/j/22   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s22_qp_13.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib22 06_0620_13/2rp   \u00a9 ucles 2022   [turn ove r   *7311277858*cambridge igcse\u2122       chemistry 0620/13     paper 1 multiple choice (core)  may/june 2022     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2022 0620/13/m/j/22  1 two different physical states of iodine are described.    in state 1, iodine exists as i2 molecules that are widely spaced and in rapid random movement.     in state 2, iodine exists as i2 molecules that are closely packed and only vibrate.    iodine can be converted directly from state 2 to form state 1.    which row about state 2 and the change from state 2 to state 1 is correct?     state 2 the change from  state 2 to state 1  a liquid evaporation  b liquid sublimation  c solid evaporation  d solid sublimation      2 a student measures the time taken for 2.0  g of magnesium to dissolve in 50  cm3 of dilute  sulfuric acid.    which apparatus is essential to complete the experiment?    1 stop-clock  2 measuring cylinder 3 thermometer 4 balance    a 1, 2 and 4 b 1 and 2 only c 1 and 4 only d 2, 3 and 4    3 which method is used to separate a mixture of the following liq uids?    liquid boiling point  / \uf0b0c  methanol 64.5  ethanol 78.5  propan-1-ol 97.2  butan-1-ol 117.0    a crystallisation  b evaporation  c filtration  d fractional distillation     ",
            "3": "3     \u00a9 ucles 2022 0620/13/m/j/22 [turn over  4 paper chromatography is used to separate four different colour ed inks, w, x, y and z, and an  unknown ink t.    the chromatogram is shown.    solvent front baseline wx y z t    which inks are present in ink t?  a w and x b w and y c x and z d y and z     5 which row identifies an alloy, a pure metal and a non-metal?     alloy pure metal non-metal  a brass carbon copper  b brass copper carbon  c copper brass carbon  d copper carbon brass     6 an atom of an element contains 4  electrons, 4 protons and 6 ne utrons.    in which group of the periodic table is this element placed?  a group ii  b group iv  c group vi  d group viii    ",
            "4": "4  \u00a9 ucles 2022 0620/13/m/j/22  7 which row describes an ionic solid?     soluble in water conducts electricity  when solid conducts electricity  when molten   a \u0016 \u001a \u0016 k e y   b \u001a \u001a \u001a \u0016 = yes  c \u0016 \u001a \u001a \u001a = no  d \u001a \u0016 \u0016       8 which molecule contains more than one pair of shared electrons?   a chlorine  b hydrogen  c hydrogen chloride  d water      9 compounds that contain nitrogen can be used as fertilisers.     which compound contains the greatest proportion of nitrogen by mass?  a c h 4n2o b n h 4cl c n h 4no 3 d ( n h 4)2so 4     ",
            "5": "5     \u00a9 ucles 2022 0620/13/m/j/22 [turn over  10 the diagram shows the electrolysis of concentrated hydrochlori c acid and concentrated aqueous  sodium chloride using carbon electrodes.    +\u2013 +\u2013 electrode 2 electrode 1 concentrated hydrochloric acidelectrode 4 electrode 3 concentrated aqueous sodium chloride    at which electrodes is hydrogen produced?  a electrode 1 only  b electrodes 1 and 3  c electrode 2 only  d electrodes 2 and 4      11 the energy level diagram for a reaction is shown.    energy progress of reactionreactantsproducts     which statement is correct?  a the reaction is endothermic and heat energy is released.  b the reaction is endothermic and heat energy is taken in.  c the reaction is exothermic and heat energy is released.  d the reaction is exothermic and heat energy is taken in.    ",
            "6": "6  \u00a9 ucles 2022 0620/13/m/j/22  12 which row identifies a chemical change and a physical change?     chemical change physical change  a boiling ethanol burning ethanol  b burning ethanol evaporating ethanol  c dissolving ethanol in water burning ethanol  d evaporating ethanol dissolving ethanol in water      13 metal m reacts with steam and produces gas g.    which row identifies gas g and the type of reaction when metal m reacts with steam?     gas g type of reaction  a hydrogen redox  b hydrogen neutralisation  c oxygen redox  d oxygen neutralisation     14 the rate of the reaction between lumps of zinc and dilute sulf uric acid is determined.    the experiment is repeated four times, making only one change e ach time.    the changes are listed.    1 the lumps of zinc are replaced with powdered zinc.  2 water is added to the dilute sulfuric acid.  3 the temperature of the dilute sulfuric acid is increased. 4 a catalyst is added to the reaction mixture.    which changes produce an increase in the rate of reaction?  a 1, 3 and 4 b 1 and 2 c 2  o n l y  d 3 and 4 only      15 water is added to anhydrous copper( ii) sulfate.    what happens during the reaction?  a the copper( ii) sulfate turns blue and the solution formed gets colder.  b the copper( ii) sulfate turns blue and the solution formed gets hotter.  c the copper( ii) sulfate turns white and the solution formed gets colder.  d the copper( ii) sulfate turns white and the solution formed gets hotter.   ",
            "7": "7     \u00a9 ucles 2022 0620/13/m/j/22 [turn over  16 which statement explains why lime is added to soil?  a to decrease the ph of acidic soil  b to decrease the ph of alkaline soil  c to increase the ph of acidic soil  d to increase the ph of alkaline soil      17 sulfur dioxide is bubbled through water containing litmus.    water and litmussulfur dioxide     which row describes and explains what happens to the litmus?     observation explanation  a it turns blue sulfur dioxide is a basic oxide  b it turns blue sulfur dioxide is an acidic oxide  c it turns red sulfur dioxide is an acidic oxide  d it turns red sulfur dioxide is a basic oxide     ",
            "8": "8  \u00a9 ucles 2022 0620/13/m/j/22  18 the oxides of two elements, x and y, are separately dissolved in water and the ph of each  solution tested.    oxide tested ph of solution  x 1  y 13    which information about x and y is correct?     oxide is  acidic oxide is  basic metal non-metal  a x y x y  b x y y x  c y x x y  d y x y x      19 an acid is neutralised by adding an excess of an insoluble soli d base.    a soluble salt is formed.    how is the pure salt obtained from the reaction mixture?  a crystallisation \uf0ae evaporation \uf0ae filtration  b evaporation \uf0ae crystallisation \uf0ae filtration  c filtration \uf0ae crystallisation \uf0ae evaporation  d filtration \uf0ae evaporation \uf0ae crystallisation    20 which ion forms a precipitate that dissolves in excess with bot h aqueous ammonia and with  aqueous sodium hydroxide?  a calcium ion, ca 2+  b copper( ii) ion, cu2+  c iron( iii) ion, fe3+  d zinc ion, zn2+    ",
            "9": "9     \u00a9 ucles 2022 0620/13/m/j/22 [turn over  21 part of the periodic table is shown.    which element is a metal?    a b c d      22 the elements sodium to argon form period 3 of the periodic tabl e.    which row describes the trend across period 3 from left to righ t?     number of  outer-shell electrons metallic  character group  number  a decreases decreases decreases  b decreases increases decreases  c increases decreases increases  d increases increases increases     23 lithium and sodium are in group i of the periodic table.    which statements about the properties of lithium and sodium are  correct?    1 lithium has a lower melting point than sodium.  2 they both produce hydrogen when they react with water. 3 lithium is less dense than sodium.  4 lithium is more reactive than sodium.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    ",
            "10": "10  \u00a9 ucles 2022 0620/13/m/j/22  24 which row describes the properties of a typical transition elem ent?     melting  point density used as  catalyst  a high high yes  b high low no  c low high yes  d low low no     25 which row describes an atom of a noble gas?     number of  protons number of  neutrons number of  electrons  a 2 2 0  b 2 2 2  c 8 8 8  d 8 8 10     26 some properties of four elements, p, q, r and s, are shown.    solid p reacts with dilute hydrochloric acid to give hydrogen.  solid q does not conduct electricity.  solid r is used to make saucepans because it is a good conducto r of heat.  solid s reacts with oxygen to form a compound where atoms of s share electrons with  atoms of oxygen.    which elements are metals?  a p and r b p and s c q and r d q and s     ",
            "11": "11     \u00a9 ucles 2022 0620/13/m/j/22 [turn over  27 three metals, x, y and z, are added separately to dilute hydro chloric acid.    the oxides of each metal are heated with carbon.    the results of the reactions are shown.     dilute aqueous  hydrochloric acid metal oxide with carbon  x no reaction brown solid forms  y fast fizzing no change  z slow fizzing silver coloured solid forms    what are x, y and z?     x  y  z   a copper calcium zinc  b copper zinc magnesium  c iron calcium zinc  d iron zinc magnesium     28 which uses of the metals shown are correct?     aluminium stainless steel  a aircraft bodies car bodies  b car bodies aircraft bodies  c chemical plant food containers  d food containers cutlery     29 carbon dioxide and methane are both greenhouse gases.    which activity produces both of these gases?  a farming animals  b cracking alkanes  c the thermal decomposition of limestone  d using petrol-powered cars    ",
            "12": "12  \u00a9 ucles 2022 0620/13/m/j/22  30 which statement about carbon monoxide is correct?  a it damages stone buildings.  b it is a pollutant which causes acid rain.  c it is produced during the decomposition of vegetation.  d it is formed during the incomplete combustion of natural gas.      31 fertilisers are used to provide three of the elements needed fo r plant growth.    which two compounds would give a fertiliser containing all thre e of these elements?  a ca(no 3)2 and (nh 4)2so 4  b ca(no 3)2 and (nh 4)3po 4  c kno 3 and (nh 4)2so 4  d kno 3 and (nh 4)3po 4     32 sulfur dioxide is tested by reacting it with acidified potassi um manganate( vii).    which colour change is seen in the test?  a blue to white  b colourless to purple  c purple to colourless  d white to blue    33 which products use calcium carbonate in their manufacture?    1 aluminium  2 cement 3 iron 4 sulfuric acid    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     34 what are the products when limestone (calcium carbonate) is he ated strongly?  a calcium hydroxide and carbon dioxide  b calcium hydroxide and carbon monoxide  c calcium oxide and carbon dioxide  d calcium oxide and carbon monoxide    ",
            "13": "13     \u00a9 ucles 2022 0620/13/m/j/22 [turn over  35 which structures represent ethene and ethanol?     ethene ethanol  a hch hhh c h  hch hchh o h   b hch hhh c h  o hch hc o h  c  hh hh c c  hch hchh o h   d  hh hh c c  o hch hc o h     36 one of the fractions obtained from the fractional distillation of petroleum is naphtha.    what is a major use of the naphtha fraction?  a as a fuel for jet aircraft  b as a lubricant for moving machine parts  c as a smooth surface covering for roads  d as a starting material to make other chemicals     37 which statement describes the process of cracking?  a it is the breakdown of a compound using electricity.  b it is the breakdown of long chain hydrocarbons.  c it is the combination of many small monomers.  d it is the separation of a mixture of hydrocarbons.     38 which temperature range is used in the production of ethanol b y fermentation?  a 0\u201320  \uf0b0c b 25\u201340  \uf0b0c c 50\u201370  \uf0b0c d 80\u2013100  \uf0b0c   ",
            "14": "14  \u00a9 ucles 2022 0620/13/m/j/22  39 a hydrocarbon is tested with aqueous bromine.    the aqueous bromine turns from orange to colourless.    which row describes the hydrocarbon?     homologous  series type of  hydrocarbon  a alkane saturated  b alkane unsaturated  c alkene saturated  d alkene unsaturated      40 which polymers are constituents of food?    1 carbohydrate  2 nylon 3 terylene   4 protein    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4   ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of cambrid ge assessment. cambridge assessment is the brand name of the un iversity of cambridge  local examinations syndicate (ucles), which is a department of the university of cambridge.    \u00a9 ucles 2022 0620/13/m/j/22  blank page  ",
            "16": "16  \u00a9 ucles 2022 0620/13/m/j/22   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s22_qp_21.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib22 06_0620_21/rp   \u00a9 ucles 2022   [turn ove r   *9070200185 *cambridge igcse\u2122       chemistry 0620/21     paper 2 multiple choice (extended)  may/june 2022     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2022 0620/21/m/j/22  1 which two gases will diffuse at the same rate, at the same tem perature?  a carbon monoxide and carbon dioxide  b carbon monoxide and nitrogen  c chlorine and fluorine  d nitrogen and oxygen      2 a student measures the time taken for 2.0  g of magnesium to dissolve in 50  cm3 of dilute  sulfuric acid.    which apparatus is essential to complete the experiment?    1 stop-clock  2 measuring cylinder 3 thermometer 4 balance    a 1, 2 and 4 b 1 and 2 only c 1 and 4 only d 2, 3 and 4    3 the numbers of protons and neutrons and the electronic structu res of four particles, w, x, y and  z, are shown.     number of  protons number of  neutrons electronic  structure  w 8 8 2,8  x 8 10 2,6  y 8 8 2,6  z 10 8 2,8    which particles have the same chemical properties?  a w and y b w and z c x and y d x and z    4 which substance should be pure for the intended use?  a a drug for curing disease  b limestone for iron extraction  c petroleum for fractional distillation  d water for washing a car    ",
            "3": "3     \u00a9 ucles 2022 0620/21/m/j/22 [turn over  5 metals and ionic compounds have similarities and differences i n their structure and properties.    which row about metals and ionic compounds is correct?     similarity difference  a both contain positive ions only ionic compounds contain anions  b both contain positive ions ionic compounds conduct using a \u2018sea  of electrons\u2019  c both are malleable only ionic compounds contain anions  d both are malleable ionic compounds conduct using a \u2018sea of elec trons\u2019     6 which diagram represents the outer-shell electron arrangement i n a nitrogen molecule?    nna nnb nnc nnd       7 the equation for the reaction between barium chloride and dilut e sulfuric acid is shown.    bac l 2  +  h 2so 4  \uf0ae  baso 4  +  2hc l    which row shows the state symbols for this equation?     bac l 2 h2so 4 b a s o 4 2hc l  a (aq) (aq) (s) (aq)  b (aq) (l) (s) (aq)  c (l) (aq) (s) (l)  d ( a q )  ( l )  ( a q )  ( l )      8 the relative atomic mass, a r, of an element is determined by comparing the mass of one atom  of  the element with the mass of one atom of element q.    what is q?  a carbon  b chlorine  c hydrogen  d oxygen    ",
            "4": "4  \u00a9 ucles 2022 0620/21/m/j/22  9 the equation for the reaction between aqueous lead( ii) nitrate and aqueous sodium chloride is  shown.    pb(no 3)2(aq)  +  2nac l (aq)  \uf0ae  pbc l 2(s)  +  2nano 3(aq)    if 100  cm3 of aqueous lead( ii) nitrate of concentration 0.1  mol  / dm3 is reacted with an excess of  aqueous sodium chloride, which mass of lead( ii) chloride is obtained?  a 1 . 1 6  g b 2 . 4 2  g c 2 . 7 8  g d 3 . 3 1  g      10 the diagram shows the electrolysis of concentrated hydrochlori c acid and concentrated aqueous  sodium chloride using carbon electrodes.    +\u2013 +\u2013 electrode 2 electrode 1 concentrated hydrochloric acidelectrode 4 electrode 3 concentrated aqueous sodium chloride    at which electrodes is hydrogen produced?  a electrode 1 only  b electrodes 1 and 3  c electrode 2 only  d electrodes 2 and 4      11 aqueous copper( ii) sulfate is electrolysed using copper electrodes.    what is the ionic half-equation for the reaction at the cathode ?  a c u   \uf0ae  cu2+  +  2e\u2013  b c u2+  +  2e\u2013  \uf0ae  cu  c 2 h+  +  2e\u2013  \uf0ae  h2  d 2 o2\u2013  \uf0ae  o 2  +  4e\u2013     ",
            "5": "5     \u00a9 ucles 2022 0620/21/m/j/22 [turn over  12 which row identifies a chemical change and a physical change?     chemical change physical change  a boiling ethanol burning ethanol  b burning ethanol evaporating ethanol  c dissolving ethanol in water burning ethanol  d evaporating ethanol dissolving ethanol in water      13 the equation for the reaction between gaseous hydrogen and gas eous iodine to form gaseous  hydrogen iodide is shown.    h2(g)  +  i2(g)  \uf0ae  2h i(g)    the reaction is exothermic.    which statement explains why the reaction is exothermic?  a energy is released when h\u2013h and i\u2013i bonds are broken.  b the bond energies of the reactants are larger than the bond en ergies of the products.  c the products are at a higher energy level than the reactants.  d more energy is released when two h i bonds are formed than is used when the h\u2013h and i\u2013i  bonds are broken.     14 acidified aqueous silver nitrate is added to a test-tube conta ining aqueous chloride ions.    the test-tube is then left in direct sunlight.    which row describes the observations and explains what happens to the reaction mixture?     observation on adding  aqueous silver nitrate observation after  leaving in sunlight explanation  a yellow precipitate precipitate dissolves silver chloride forms  b yellow precipitate precipitate turns grey silver ions are reduc ed  c white precipitate precipitate dissolves silver chloride forms  d white precipitate precipitate turns grey silver ions are reduce d     ",
            "6": "6  \u00a9 ucles 2022 0620/21/m/j/22  15 water is added to anhydrous copper( ii) sulfate.    what happens during the reaction?  a the copper( ii) sulfate turns blue and the solution formed gets colder.  b the copper( ii) sulfate turns blue and the solution formed gets hotter.  c the copper( ii) sulfate turns white and the solution formed gets colder.  d the copper( ii) sulfate turns white and the solution formed gets hotter.      16 aqueous iron( iii) chloride, fec l 3, reacts with aqueous potassium iodide, k i.    vfec l 3  +  wki  \uf0ae  xfec l 2  +  ykc l  +  i2    which statements are correct?    1 in the balanced equation, v, w, x and y have the same value.  2 potassium iodide is an oxidising agent.  3 a dark brown solution is produced in the reaction.    a 1 and 2 b 1 and 3 c 2  o n l y  d 2 and 3    17 which statement about acids is correct?  a a strong acid has a higher ph than a weak acid of the same conc entration.  b a strong acid is a proton acceptor.  c a weak acid is a proton donor.  d a weak acid is fully ionised in aqueous solution.    ",
            "7": "7     \u00a9 ucles 2022 0620/21/m/j/22 [turn over  18 the oxides of two elements, x and y, are separately dissolved in water and the ph of each  solution tested.    oxide tested ph of solution  x 1  y 13    which information about x and y is correct?     oxide is  acidic oxide is  basic metal non-metal  a x y x y  b x y y x  c y x x y  d y x y x      19 an acid is neutralised by adding an excess of an insoluble soli d base.    a soluble salt is formed.    how is the pure salt obtained from the reaction mixture?  a crystallisation \uf0ae evaporation \uf0ae filtration  b evaporation \uf0ae crystallisation \uf0ae filtration  c filtration \uf0ae crystallisation \uf0ae evaporation  d filtration \uf0ae evaporation \uf0ae crystallisation    20 the electronic structure of element z is 2,8,1.    which statements about z are correct?    1 it is a metal.  2 it has two outer-shell electrons. 3 it is in period 3.    a 1, 2 and 3 b 1 and 2 only c 1 and 3 only d 2  o n l y     ",
            "8": "8  \u00a9 ucles 2022 0620/21/m/j/22  21 elements in  group iv of the periodic table are shown.    carbon  silicon  germanium  tin  lead    what does not occur in group iv as it is descended?  a the proton number of the elements increases.  b the elements become more metallic.  c the elements have more electrons in their outer shell.  d the elements have more electron shells.    22 element m forms both m + and m2+ ions.    in which part of the periodic table is m placed?  a group i  b group ii  c group iii  d transition elements     23 in the extraction of aluminium by electrolysis, cryolite is ad ded to the bauxite ore.    which row describes the role of cryolite and gives the ionic ha lf-equation at the cathode?     role of cryolite ionic half-equation at the cathode  a catalyst a l 3+  +  3e\u2013  \uf0ae  a l  b catalyst a l 3+  +  3e\u2013  \uf0ae  3a l  c lowers melting point of electrolyte a l 3+  +  3e\u2013  \uf0ae  a l  d lowers melting point of electrolyte a l 3+  +  3e\u2013  \uf0ae  3a l     ",
            "9": "9     \u00a9 ucles 2022 0620/21/m/j/22 [turn over  24 mild steel is galvanised to prevent corrosion of the iron.    which statements about galvanising are correct?    1 galvanising prevents corrosion because the zinc forms an allo y.  2 if the coating is damaged, water and oxygen do not corrode th e iron.  3 zinc is a sacrificial metal and corrodes in preference to iro n.    a 1 and 2 b 1 and 3 c 2  o n l y  d 2 and 3      25 which diagram represents the arrangement of the outer-shell el ectrons of a noble gas?    a b cd      26 which statements about the general properties of metals are co rrect?    1 they are good conductors of heat and electricity.  2 they have low melting points. 3 they react with dilute acids to form a salt and water. 4 they react with oxygen to form basic oxides.    a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    27 reactions of three metals and their oxides are shown.    metal add dilute  hydrochloric acid  to metal heat  metal oxide with carbon   1 \u0016 \u0016 k e y   2 \u0016 \u001a \u0016 = reacts  3 \u001a \u0016 \u001a = does not react    what is the order of reactivity of these metals, from most reac tive to least reactive?  a 1  \uf0ae 2 \uf0ae 3 b 1  \uf0ae 3 \uf0ae 2 c 2  \uf0ae 1 \uf0ae 3 d 2  \uf0ae 3 \uf0ae 1     ",
            "10": "10  \u00a9 ucles 2022 0620/21/m/j/22  28 three metal compounds, j, k and l, are heated using a bunsen bu rner.    the results are shown.    j colourless gas produced, which relights a glowing splint  k colourless gas produced, which turns limewater milky l no reaction    which row identifies j, k and l?     j  k  l   a magnesium carbonate potassium carbonate potassium nitrate  b magnesium carbonate potassium nitrate potassium carbonate  c potassium nitrate magnesium carbonate potassium carbonate  d potassium nitrate potassium carbonate magnesium carbonate      29 the diagram shows the uses and treatment processes of muddy ri ver water.    muddy river water clear river water disinfected water use 1 use 2process 1 process 2     which row identifies uses 1 and 2 and processes 1 and 2?     use 1 use 2 process 1 process 2  a drinking watering crops chlorination filtration  b drinking watering crops filtration chlorination  c watering crops drinking chlorination filtration  d watering crops drinking filtration chlorination     ",
            "11": "11     \u00a9 ucles 2022 0620/21/m/j/22 [turn over  30 the equation for the manufacture of ammonia in the haber proce ss is shown.    3h2(g)  +  n 2(g)    2nh 3(g)    the forward reaction is exothermic.    which row describes the effect of the stated change on the reac tion rate and the yield of  ammonia?     change effect on reaction rate effect on yield of ammonia  a decrease pressure increases decreases  b decrease temperature decreases increases  c increase pressure increases decreases  d increase temperature increases increases     31 fertilisers are used to provide three of the elements needed fo r plant growth.    which two compounds would give a fertiliser containing all thre e of these elements?  a ca(no 3)2 and (nh 4)2so 4  b ca(no 3)2 and (nh 4)3po 4  c kno 3 and (nh 4)2so 4  d kno 3 and (nh 4)3po 4    32 the flow chart shows part of the process for the manufacture of  sulfuric acid and its electrolysis.    gas 1gas 2 gas 3concentrated sulfuric aciddilute sulfuric acidelectrolysis     what are gases 1, 2 and 3?     gas 1 gas 2 gas 3  a sulfur dioxide hydrogen sulfur trioxide  b sulfur dioxide oxygen sulfur trioxide  c sulfur trioxide hydrogen sulfur dioxide  d sulfur trioxide oxygen sulfur dioxide     ",
            "12": "12  \u00a9 ucles 2022 0620/21/m/j/22  33 which statements about sulfur dioxide are correct?    1 sulfur dioxide decolourises acidified potassium manganate( vii).  2 sulfur dioxide forms when acids react with carbonates.  3 sulfur dioxide is used as a bleach.  4 sulfur dioxide is used to treat acidic soil.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4    34 what are the products when limestone (calcium carbonate) is he ated strongly?  a calcium hydroxide and carbon dioxide  b calcium hydroxide and carbon monoxide  c calcium oxide and carbon dioxide  d calcium oxide and carbon monoxide    35 the structure of ester w is shown.    c hh hco o ch hh     which row gives the names of ester w and the carboxylic acid an d alcohol from which it is made?     name of ester w carboxylic acid alcohol  a ethyl methanoate ethanoic acid methanol  b ethyl methanoate methanoic acid ethanol  c methyl ethanoate ethanoic acid methanol  d methyl ethanoate methanoic acid ethanol      36 ethanol is made industrially by the fermentation of glucose or  by the catalytic addition of steam to  ethene.    which statement describes an advantage of fermentation compared  to catalytic addition?  a ethanol is the only product of fermentation.  b fermentation uses a batch process but catalytic addition is co ntinuous.  c fermentation uses a higher temperature than catalytic addition .  d fermentation uses a renewable resource. ",
            "13": "13     \u00a9 ucles 2022 0620/21/m/j/22 [turn over  37 some properties of colourless liquid l are listed.    \u25cf it boils at 65  \uf0b0c.  \u25cf when added to water, two layers form which do not mix.  \u25cf it does not react with sodium carbonate. \u25cf it has no effect on bromine water.    what is l?  a ethanol  b hexane  c hexene  d ethanoic acid    38 a molecule of compound p contains two carbon atoms and four hy drogen atoms.    which row represents p?     name of  compound m r reacts with  aqueous bromine  a ethane 30 \u001a  b ethene 16 \u0016  c ethene 28 \u0016  d ethene 28 \u001a      39 the reaction of ethanol with acidified potassium manganate( vii) is shown.    ch3ch2oh ch3coohkmno4 h+    which type of reaction is taking place?  a addition  b condensation  c hydrolysis  d oxidation     ",
            "14": "14  \u00a9 ucles 2022 0620/21/m/j/22  40 which polymer is a synthetic polyamide?  a nylon  b poly(ethene)  c p r o t e i n   d terylene    ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of cambrid ge assessment. cambridge assessment is the brand name of the un iversity of cambridge  local examinations syndicate (ucles), which is a department of the university of cambridge.    \u00a9 ucles 2022 0620/21/m/j/22  blank page  ",
            "16": "16  \u00a9 ucles 2022 0620/21/m/j/22   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s22_qp_22.pdf": {
            "1": "    this document has 16 pages.  ib22 06_0620_22/2rp   \u00a9 ucles 2022   [turn ove r   *2772444271 *cambridge igcse\u2122       chemistry 0620/22     paper 2 multiple choice (extended)  may/june 2022     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2022 0620/22/m/j/22  1 which two gases will diffuse at the same rate, at the same tem perature?  a carbon monoxide and carbon dioxide  b carbon monoxide and nitrogen  c chlorine and fluorine  d nitrogen and oxygen      2 a student measures the time taken for 2.0  g of magnesium to dissolve in 50  cm3 of dilute  sulfuric acid.    which apparatus is essential to complete the experiment?    1 stop-clock  2 measuring cylinder 3 thermometer 4 balance    a 1, 2 and 4 b 1 and 2 only c 1 and 4 only d 2, 3 and 4    3 a chromatogram of a single substance t is shown.    solvent front baseline1 23 4     which measurements are used to find the rf value of t?  a 1 and 2 b 1 and 4 c 2 and 3 d 3 and 4    4 x and y are two different elements.    x and y have the same number of nucleons.    which statement about x and y is correct?  a they have the same physical properties.  b their atoms have the same number of electrons.  c they are in different groups of the periodic table.  d they have different relative masses. ",
            "3": "3     \u00a9 ucles 2022 0620/22/m/j/22 [turn over  5 the diagrams show the structures of three macromolecules p, q a nd r.    pq r     what are p, q and r?     p  q  r   a diamond silicon( iv) oxide graphite  b graphite diamond silicon( iv) oxide  c silicon( iv) oxide diamond graphite  d silicon( iv) oxide graphite diamond     6 which dot-and-cross diagram shows the arrangement of outer she ll electrons in a molecule of  hydrogen chloride?    ha cl hb cl hc cl cl hd      7 the equation for the reaction between barium chloride and dilut e sulfuric acid is shown.    bac l  2  +  h 2so 4  \uf0ae  baso 4  +  2hc l    which row shows the state symbols for this equation?     bac l 2 h2so 4 b a s o 4 2hc l  a (aq) (aq) (s) (aq)  b (aq) (l) (s) (aq)  c (l) (aq) (s) (l)  d ( a q )  ( l )  ( a q )  ( l )      ",
            "4": "4  \u00a9 ucles 2022 0620/22/m/j/22  8 methane and steam react in the presence of a catalyst.    ch 4(g)  +  h 2o(g)  \uf0ae  co(g)  +  3h 2(g)    0.5  mol of methane reacts completely with 0.5  mol of steam.    what is the volume of carbon monoxide and hydrogen produced, me asured at room temperature  and pressure?     volume  of co  / dm3 volume  of h 2 / dm3  a 0.5 1.5  b 1.0 3.0  c 12.0 12.0  d 12.0 36.0     9 a compound of element x has the formula x 2o and a relative formula mass of 144.    what is element x?  a copper, cu  b gadolinium, gd  c sulfur, s  d tellurium, te     ",
            "5": "5     \u00a9 ucles 2022 0620/22/m/j/22 [turn over  10 the diagram shows the electrolysis of concentrated hydrochlori c acid and concentrated aqueous  sodium chloride using carbon electrodes.    +\u2013 +\u2013 electrode 2 electrode 1 concentrated hydrochloric acidelectrode 4 electrode 3 concentrated aqueous sodium chloride    at which electrodes is hydrogen produced?  a electrode 1 only  b electrodes 1 and 3  c electrode 2 only  d electrodes 2 and 4      11 the diagram shows the electrolysis of aqueous copper( ii) sulfate using inert electrodes.    which arrow shows the movement of electrons in the circuit?    power supply anode cathodeab c d      ",
            "6": "6  \u00a9 ucles 2022 0620/22/m/j/22  12 which row identifies a chemical change and a physical change?     chemical change physical change  a boiling ethanol burning ethanol  b burning ethanol evaporating ethanol  c dissolving ethanol in water burning ethanol  d evaporating ethanol dissolving ethanol in water      13 which statements explain why increasing the concentration of a  reactant increases the rate of  reaction?    1 it increases the collision rate of particles.  2 it lowers the activation energy.  3 a greater proportion of the colliding molecules have the requ ired activation energy.  4 there are more particles per unit volume.    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      14 when the colourless gas n 2o4 is heated, it forms the brown gas no 2.    when the reaction mixture is cooled, the brown colour fades and  turns back to colourless.    which type of reaction is described by these observations?  a decomposition  b displacement  c reduction  d reversible     15 water is added to anhydrous copper( ii) sulfate.    what happens during the reaction?  a the copper( ii) sulfate turns blue and the solution formed gets colder.  b the copper( ii) sulfate turns blue and the solution formed gets hotter.  c the copper( ii) sulfate turns white and the solution formed gets colder.  d the copper( ii) sulfate turns white and the solution formed gets hotter.     ",
            "7": "7     \u00a9 ucles 2022 0620/22/m/j/22 [turn over  16 which arrow on the energy level diagram shows the overall energ y change for an endothermic  reaction?    energy progress of reactionreactantsproductsa bdc      17 when a hydrogen\u2013oxygen fuel cell is in operation, a different r eaction happens at each electrode.    at the hydrogen electrode h 2  \uf0ae  2h+  +  2e\u2013  at the oxygen electrode o 2  +  2h 2o  +  4e\u2013  \uf0ae  4oh\u2013    the electrons that are lost at the hydrogen electrode travel th rough the external circuit to the  oxygen electrode, where they are gained by the oxygen and water .    a hydrogen\u2013oxygen fuel cell is operated for a period of time an d four moles of oxygen molecules  are consumed.    which mass of hydrogen is consumed?  a 2 . 0  g b 4 . 0  g c 8 . 0  g d 16.0  g    18 the oxides of two elements, x and y, are separately dissolved in water and the ph of each  solution tested.    oxide tested ph of solution  x 1  y 13    which information about x and y is correct?     oxide is  acidic oxide is  basic metal non-metal  a x y x y  b x y y x  c y x x y  d y x y x     ",
            "8": "8  \u00a9 ucles 2022 0620/22/m/j/22  19 an acid is neutralised by adding an excess of an insoluble soli d base.    a soluble salt is formed.    how is the pure salt obtained from the reaction mixture?  a crystallisation \uf0ae evaporation \uf0ae filtration  b evaporation \uf0ae crystallisation \uf0ae filtration  c filtration \uf0ae crystallisation \uf0ae evaporation  d filtration \uf0ae evaporation \uf0ae crystallisation    20 substance j takes part in a redox reaction.    in the reaction, j gains electrons.    which statement is correct?  a j is the oxidising agent and it is oxidised in the reaction.  b j is the oxidising agent and i t is reduced in the reaction.  c j is the reducing agent and it is oxidised in the reaction.  d j is the reducing agent and it i s reduced in the reaction.    21 elements in  group iv of the periodic table are shown.    carbon  silicon  germanium  tin  lead    what does not occur in group iv as it is descended?  a the proton number of the elements increases.  b the elements become more metallic.  c the elements have more electrons in their outer shell.  d the elements have more electron shells.    ",
            "9": "9     \u00a9 ucles 2022 0620/22/m/j/22 [turn over  22 which statement about acids is correct?  a acids are proton acceptors.  b acids transfer electrons to bases in aqueous solution.  c hydrochloric acid reacts with ammonium hydroxide to produce am monia.  d ethanoic acid partially ionises in aqueous solution.      23 which elements have both a high melting point and variable oxid ation states?  a alkali metals  b transition elements  c halogens  d noble gases      24 lithium, sodium and potassium are elements in group i of the p eriodic table.    chlorine, bromine and iodine are elements in group vii of the p eriodic table.    which row identifies the least  dense of these elements in each group?     group i group vii  a lithium chlorine  b lithium iodine  c potassium chlorine  d potassium iodine     ",
            "10": "10  \u00a9 ucles 2022 0620/22/m/j/22  25 the reactions of metals p, q, r and s are shown.    metal reaction  with water reaction with  hydrochloric acid reduction of the  metal oxide with carbon  p no reaction no reaction reduced  q slow vigorous no reaction  r vigorous vigorous no reaction  s very slow vigorous reduced    what is the order of reactivity of the metals?     least  reactive  most  reactive  a p s q r  b p q s r  c r s q p  d r q s p      26 the number of protons and the number of neutrons in the atoms of elements x, y and z are  shown.     number of  protons number of  neutrons  x 6 6  y 7 6  z 8 10    which statement about the elements is correct?  a x and y are isotopes of the same element.  b z forms an ion with a +2 charge.  c x and z react together to form an ionic compound.  d x, y and z are non-metals.     ",
            "11": "11     \u00a9 ucles 2022 0620/22/m/j/22 [turn over  27 which diagram represents the arrangement of atoms in an alloy?     abcd      28 three metal compounds, j, k and l, are heated using a bunsen bu rner.    the results are shown.    j colourless gas produced, which relights a glowing splint  k colourless gas produced, which turns limewater milky l no reaction    which row identifies j, k and l?     j  k  l   a magnesium carbonate potassium carbonate potassium nitrate  b magnesium carbonate potassium nitrate potassium carbonate  c potassium nitrate magnesium carbonate potassium carbonate  d potassium nitrate potassium carbonate magnesium carbonate     29 processes involved in the extraction of zinc are listed.    1 heat zinc oxide with carbon.  2 condense zinc vapour.  3 vaporise the zinc. 4 roast zinc ore in air.    in which order are the processes carried out?  a 1  \uf0ae 2 \uf0ae 3 \uf0ae 4  b 4  \uf0ae 3 \uf0ae 1 \uf0ae 2  c 4  \uf0ae 1 \uf0ae 3 \uf0ae 2  d 1  \uf0ae 4 \uf0ae 3 \uf0ae 2     ",
            "12": "12  \u00a9 ucles 2022 0620/22/m/j/22  30 which process uses sacrificial protection to prevent steel fro m rusting?  a galvanising  b oiling  c copper plating  d painting      31 fertilisers are used to provide three of the elements needed fo r plant growth.    which two compounds would give a fertiliser containing all thre e of these elements?  a ca(no 3)2 and (nh 4)2so 4  b ca(no 3)2 and (nh 4)3po 4  c kno 3 and (nh 4)2so 4  d kno 3 and (nh 4)3po 4    32 which processes produce carbon dioxide?    1 respiration  2 photosynthesis  3 fermentation 4 combustion of hydrogen    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4      33 which reaction in the contact process requires the use of a ca talyst?  a s  +  o 2  \uf0ae  so 2  b 2 s o 2  +  o 2  \uf0ae  2so 3  c s o 3  +  h 2so 4  \uf0ae  h2s2o7  d h 2s2o7  +  h 2o  \uf0ae  2h 2so 4      34 what are the products when limestone (calcium carbonate) is he ated strongly?  a calcium hydroxide and carbon dioxide  b calcium hydroxide and carbon monoxide  c calcium oxide and carbon dioxide  d calcium oxide and carbon monoxide     ",
            "13": "13     \u00a9 ucles 2022 0620/22/m/j/22 [turn over  35 the structure of ester w is shown.    c hh hco o ch hh     which row gives the names of ester w and the carboxylic acid an d alcohol from which it is made?     name of ester w carboxylic acid alcohol  a ethyl methanoate ethanoic acid methanol  b ethyl methanoate methanoic acid ethanol  c methyl ethanoate ethanoic acid methanol  d methyl ethanoate methanoic acid ethanol     36 ethene reacts with substance x to form ethanol.    what is x?  a ethanoic acid  b glucose  c hydrogen  d steam    37 alkenes can be produced by cracking large hydrocarbon molecules  to form smaller hydrocarbon  molecules.    which equations represent possible reactions when tetradecane, c 14h30, is cracked?    1 c 14h30  \uf0ae  c2h6  +  c 3h6  +  c 4h8  +  c 5h10  2 c 14h30  \uf0ae  h2  +  c 2h4  +  c 3h6  +  c 4h8  +  c 5h10  3 c 14h30  \uf0ae  c2h6  +  4c 3h6  4 c 14h30  \uf0ae  c2h6  +  c 3h8  +  c 9h18    a 1 only b 1 and 4 c 1, 2 and 3 d 3 and 4    ",
            "14": "14  \u00a9 ucles 2022 0620/22/m/j/22  38 the structures of some hydrocarbons are shown.    hch hch1 hch hh hch hc hch hhhch hch23 hc hch h hc hhh hcch c h ch hh hh4 h hh     which statement about the hydrocarbons is correct?  a 1 and 2 have a different general formula.  b 1 and 4 are in different homologous series.  c 2 and 3 are structural isomers.  d 3 and 4 have the same empirical formula.    39 ethane reacts with chlorine in the presence of ultraviolet lig ht.    which substances are produced in the reaction?    hch hch hcl2 hch clch clh3 h h1 h cl4     a 1, 2 and 3  b  1 and 3 only  c  2, 3 and 4  d  2 and 4 only    ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of cambrid ge assessment. cambridge assessment is the brand name of the un iversity of cambridge  local examinations syndicate (ucles), which is a department of the university of cambridge.    \u00a9 ucles 2022 0620/22/m/j/22  40 which polymer structure has the same linkages as terylene ?    nc oo hcch3 ch3a c h nc hch3 hc h3c c hco n nc hch3ch3d c honc hch3ch3b c hco o      ",
            "16": "16  \u00a9 ucles 2022 0620/22/m/j/22   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s22_qp_23.pdf": {
            "1": "    this document has 16 pages. any blank pages are indicated.  ib22 06_0620_23/rp   \u00a9 ucles 2022   [turn ove r   *3981974951 *cambridge igcse\u2122       chemistry 0620/23     paper 2 multiple choice (extended)  may/june 2022     45 minutes    you must answer on the mult iple choice answer sheet.    you will need: multiple choice answer sheet   soft clean eraser   soft pencil (type b or hb is recommended)       instructions   \uf0b7 there are forty  questions on this paper. answer all questions.   \uf0b7 for each question there ar e four possible answers a, b, c and d. choose the one you consider correct  and record your choice in soft pencil on the multiple choice an swer sheet.   \uf0b7 follow the instructions on the multiple choice answer sheet.  \uf0b7 write in soft pencil.  \uf0b7 write your name, centre number and candidate number on the mult iple choice answer sheet in the  spaces provided unless this has been done for you.  \uf0b7 do not use correction fluid.  \uf0b7 do not write on any bar codes.  \uf0b7 you may use a calculator.      information  \uf0b7 the total mark for this paper is 40.  \uf0b7 each correct answer will score one mark.  \uf0b7 any rough working should be don e on this question paper.  \uf0b7 the periodic table is pri nted in the question paper.   ",
            "2": "2  \u00a9 ucles 2022 0620/23/m/j/22  1 which two gases will diffuse at the same rate, at the same tem perature?  a carbon monoxide and carbon dioxide  b carbon monoxide and nitrogen  c chlorine and fluorine  d nitrogen and oxygen      2 a student measures the time taken for 2.0  g of magnesium to dissolve in 50  cm3 of dilute  sulfuric acid.    which apparatus is essential to complete the experiment?    1 stop-clock  2 measuring cylinder 3 thermometer 4 balance    a 1, 2 and 4 b 1 and 2 only c 1 and 4 only d 2, 3 and 4     3 which statement describes the properties of both diamond and si licon( iv) oxide?  a they are brittle, with a low melting point, and are insoluble in water.  b they are hard, with a high melt ing point, and are electrical i nsulators.  c they are malleable, with a high melting point, and are electri cal conductors.  d they are soft, with a low melting point, and are electrical in sulators.     ",
            "3": "3     \u00a9 ucles 2022 0620/23/m/j/22 [turn over  4 paper chromatography is used to separate four different colour ed inks, w, x, y and z, and an  unknown ink t.    the chromatogram is shown.    solvent front baseline wx y z t    which inks are present in ink t?  a w and x b w and y c x and z d y and z     5 particle p has an atomic number of 18, a mass number of 40 and  no overall charge.    particle q has an atomic number of 19, a mass number of 40 and a single positive charge.    which statement is correct?  a they are isotopes of the same element.  b they are both ions.  c q has more neutrons than p.  d they have the same number of electrons in their outer shell.      6 which statement about the properties of metals is correct?  a metals are malleable because the layers of positive ions can s lide over each other.  b metals conduct electricity when solid because the positive ion s move freely through the  metal.  c metals conduct electricity because there is a strong force of attraction between the positive  ions and the delocalised electrons.  d metals have a high melting point because the positive ions att ract each other strongly.     ",
            "4": "4  \u00a9 ucles 2022 0620/23/m/j/22  7 the equation for the reaction between barium chloride and dilut e sulfuric acid is shown.    bac l 2  +  h 2so 4  \uf0ae  baso 4  +  2hc l    which row shows the state symbols for this equation?     bac l 2 h2so 4 b a s o 4 2hc l  a (aq) (aq) (s) (aq)  b (aq) (l) (s) (aq)  c (l) (aq) (s) (l)  d ( a q )  ( l )  ( a q )  ( l )      8 a 0.5  g sample of calcium carbonate is reacted with excess dilute hyd rochloric acid.    caco 3(s)  +  2hc l (aq)  \uf0ae  cac l 2(aq)  +  h 2o(l)  +  co 2(g)    which volume of co 2 is produced at r.t.p.?  a 0.12  dm3 b 0.18  dm3 c 0.24  dm3 d 12  dm3     9 aluminium is manufactured from aluminium oxide by electrolysis .    which row shows the ionic half-equations at each electrode and describes the role of cryolite in  the process?     reaction at anode reaction at cathode role of cryolite  a 2o2\u2013  \uf0ae  o 2  +  4e\u2013 a l 3+  +  3e\u2013  \uf0ae  3a l c a t a l y s t   b al 3+  +  3e\u2013  \uf0ae  a l 2 o2\u2013  \uf0ae  o 2  +  4e\u2013 solvent for aluminium oxide  c 2o2\u2013  \uf0ae  o 2  +  4e\u2013 a l 3+  +  3e\u2013  \uf0ae  a l solvent for aluminium oxide  d al 3+  +  3e\u2013  \uf0ae  3a l 2 o2\u2013  \uf0ae  o 2  +  4e\u2013 c a t a l y s t      ",
            "5": "5     \u00a9 ucles 2022 0620/23/m/j/22 [turn over  10 the diagram shows the electrolysis of concentrated hydrochlori c acid and concentrated aqueous  sodium chloride using carbon electrodes.    +\u2013 +\u2013 electrode 2 electrode 1 concentrated hydrochloric acidelectrode 4 electrode 3 concentrated aqueous sodium chloride    at which electrodes is hydrogen produced?  a electrode 1 only  b electrodes 1 and 3  c electrode 2 only  d electrodes 2 and 4      11 which statement about fuels is correct?  a coal and ethanol are examples of non-renewable energy sources.  b hydrogen and oxygen can be reacted to produce an electric curre nt.  c large amounts of energy are taken in by a fuel when it burns.  d radioactive isotopes are burned to produce heat.      12 which row identifies a chemical change and a physical change?     chemical change physical change  a boiling ethanol burning ethanol  b burning ethanol evaporating ethanol  c dissolving ethanol in water burning ethanol  d evaporating ethanol dissolving ethanol in water     ",
            "6": "6  \u00a9 ucles 2022 0620/23/m/j/22  13 metal m reacts with steam and produces gas g.    which row identifies gas g and the type of reaction when metal m reacts with steam?     gas g type of reaction  a hydrogen redox  b hydrogen neutralisation  c oxygen redox  d oxygen neutralisation     14 which statement explains why increasing the concentration of a  reactant increases the rate of the  reaction?  a a greater proportion of the particles have the activation energ y so there are more successful  collisions.  b particles have more energy so there are more frequent collision s.  c there are more particles in the same volume so there are more f requent collisions.  d the particles move more quickly so there are more frequent coll isions.      15 water is added to anhydrous copper( ii) sulfate.    what happens during the reaction?  a the copper( ii) sulfate turns blue and the solution formed gets colder.  b the copper( ii) sulfate turns blue and the solution formed gets hotter.  c the copper( ii) sulfate turns white and the solution formed gets colder.  d the copper( ii) sulfate turns white and the solution formed gets hotter.      16 which statement explains why lime is added to soil?  a to decrease the ph of acidic soil  b to decrease the ph of alkaline soil  c to increase the ph of acidic soil  d to increase the ph of alkaline soil    ",
            "7": "7     \u00a9 ucles 2022 0620/23/m/j/22 [turn over  17 sulfur dioxide is bubbled through water containing litmus.    water and litmussulfur dioxide     which row describes and explains what happens to the litmus?     observation explanation  a it turns blue sulfur dioxide is a basic oxide  b it turns blue sulfur dioxide is an acidic oxide  c it turns red sulfur dioxide is an acidic oxide  d it turns red sulfur dioxide is a basic oxide     18 the oxides of two elements, x and y, are separately dissolved in water and the ph of each  solution tested.    oxide tested ph of solution  x 1  y 13    which information about x and y is correct?     oxide is  acidic oxide is  basic metal non-metal  a x y x y  b x y y x  c y x x y  d y x y x     ",
            "8": "8  \u00a9 ucles 2022 0620/23/m/j/22  19 an acid is neutralised by adding an excess of an insoluble soli d base.    a soluble salt is formed.    how is the pure salt obtained from the reaction mixture?  a crystallisation \uf0ae evaporation \uf0ae filtration  b evaporation \uf0ae crystallisation \uf0ae filtration  c filtration \uf0ae crystallisation \uf0ae evaporation  d filtration \uf0ae evaporation \uf0ae crystallisation    20 which ion forms a precipitate that dissolves in excess with bot h aqueous ammonia and with  aqueous sodium hydroxide?  a calcium ion, ca 2+  b copper( ii) ion, cu2+  c iron( iii) ion, fe3+  d zinc ion, zn2+    21 elements in  group iv of the periodic table are shown.    carbon  silicon  germanium  tin  lead    what does not occur in group iv as it is descended?  a the proton number of the elements increases.  b the elements become more metallic.  c the elements have more electrons in their outer shell.  d the elements have more electron shells.    ",
            "9": "9     \u00a9 ucles 2022 0620/23/m/j/22 [turn over  22 w, x, y and z are elements in period 3 of the periodic table.    the numbers of outer-shell electrons in an atom of each element  are shown.    element number of  outer-shell electrons  w 1  x 2  y 7  z 8    which elements are non-metals?  a w, x and y b w and x only c y and z d z only    23 selenium is an element in group vi.    group vi elements follow similar trends to group vii elements.    which statement about selenium is correct?  a it has a higher density than sulfur.  b it has a lower melting point than sulfur.  c it has six electron shells.  d it is a monoatomic element.    24 which row describes the properties of a typical transition elem ent?     melting  point density used as  catalyst  a high high yes  b high low no  c low high yes  d low low no     ",
            "10": "10  \u00a9 ucles 2022 0620/23/m/j/22  25 which row describes an atom of a noble gas?     number of  protons number of  neutrons number of  electrons  a 2 2 0  b 2 2 2  c 8 8 8  d 8 8 10     26 some properties of four elements, p, q, r and s, are shown.    solid p reacts with dilute hydrochloric acid to give hydrogen.  solid q does not conduct electricity.  solid r is used to make saucepans because it is a good conducto r of heat.  solid s reacts with oxygen to form a compound where atoms of s share electrons with  atoms of oxygen.    which elements are metals?  a p and r b p and s c q and r d q and s      27 which substance is used to reduce zinc oxide in the manufactur e of zinc?  a carbon  b carbon dioxide  c hydrogen  d sulfur dioxide     ",
            "11": "11     \u00a9 ucles 2022 0620/23/m/j/22 [turn over  28 three metal compounds, j, k and l, are heated using a bunsen bu rner.    the results are shown.    j colourless gas produced, which relights a glowing splint  k colourless gas produced, which turns limewater milky l no reaction    which row identifies j, k and l?     j  k  l   a magnesium carbonate potassium carbonate potassium nitrate  b magnesium carbonate potassium nitrate potassium carbonate  c potassium nitrate magnesium carbonate potassium carbonate  d potassium nitrate potassium carbonate magnesium carbonate      29 nitrogen oxide, no, is formed in the engine of petrol-powered cars.    one constituent of petrol is octane, c 8h18.    nitrogen oxide is removed from exhaust fumes by catalytic conve rters.    which row identifies the reactants that produce nitrogen oxide and a reaction that removes it in a  catalytic converter?     reactants that produce no reaction that removes no  a octane + one gas found in air 2no  +  2co  \uf0ae  n2  +  2co 2  b octane + one gas found in air no  +  co 2  \uf0ae  no 2  +  co  c two gases found in air 2no  +  2co  \uf0ae  n2  +  2co 2  d two gases found in air no  +  co 2  \uf0ae  no 2  +  co      30 a magnesium block is attached to iron to prevent it from rusti ng.    which statement about this method of rust prevention is correct ?  a magnesium corrodes instead of iron because it is more reactive .  b magnesium prevents oxygen from reaching the iron.  c the iron does not rust because it has a greater tendency to fo rm ions than magnesium.  d this method of rust prevention is called galvanising.    ",
            "12": "12  \u00a9 ucles 2022 0620/23/m/j/22  31 fertilisers are used to provide three of the elements needed fo r plant growth.    which two compounds would give a fertiliser containing all thre e of these elements?  a ca(no 3)2 and (nh 4)2so 4  b ca(no 3)2 and (nh 4)3po 4  c kno 3 and (nh 4)2so 4  d kno 3 and (nh 4)3po 4    32 which processes increase the amount of carbon dioxide in the ai r?    1 combustion of hydrogen  2 combustion of methane 3 photosynthesis by plants 4 thermal decomposition of limestone    a 1 and 3 b 1 and 4 c 2 and 3 d 2 and 4     33 in the contact process, sulfur dioxide is converted into sulfur  trioxide.    2so 2(g)  +  o 2(g)    2so 3(g)    w h a t  i s  t h e  e f f e c t  o f  l o w e r i n g  t h e  p r e s s u r e  o n  t h e  r a t e  o f  f o r m ation and percentage yield of  sulfur trioxide at equilibrium?     rate of  formation percentage  yield  a decreases decreases  b decreases increases  c increases decreases  d increases increases      34 what are the products when limestone (calcium carbonate) is he ated strongly?  a calcium hydroxide and carbon dioxide  b calcium hydroxide and carbon monoxide  c calcium oxide and carbon dioxide  d calcium oxide and carbon monoxide     ",
            "13": "13     \u00a9 ucles 2022 0620/23/m/j/22 [turn over  35 the structure of ester w is shown.    c hh hco o ch hh     which row gives the names of ester w and the carboxylic acid an d alcohol from which it is made?     name of ester w carboxylic acid alcohol  a ethyl methanoate ethanoic acid methanol  b ethyl methanoate methanoic acid ethanol  c methyl ethanoate ethanoic acid methanol  d methyl ethanoate methanoic acid ethanol     36 the equation for the reaction between butane, c 4h10, and chlorine is shown.    c4h10  +  c l 2  \uf0ae  c4h9cl  +  hc l    which type of reaction does butane undergo when it reacts with chlorine?  a addition  b reduction  c acid\u2013base  d substitution     37 butene has three structural isomers which are alkenes.    which statements about these isomers are correct?    1 they have the same molecular formula.  2 they have different numbers of bonds in the molecule.  3 they have a c=c bond in the structure.    a 1 and 2 b 1 and 3 c 2  o n l y  d 3  o n l y     ",
            "14": "14  \u00a9 ucles 2022 0620/23/m/j/22  38 the hydrocarbon c 12h26 is cracked to give x and y, as shown.    c12h26  \uf0ae  x  +  y    which statement is correct?  a if x is c 6h12 then y will react with aqueous bromine.  b if x is c 10h22 then y can be used to make a polymer.  c if x is a hydrogen molecule then y is an alkane.  d x and y could be structural isomers.      39 an ester, c 4h8o2, is made by reacting 0.06  mol of ethanol, c 2h6o, and 0.05  mol of ethanoic acid,  c2h4o2.    c2h6o  +  c 2h4o2  \uf0ae  c4h8o2  +  h 2o    0.0375  mol of the ester was made.    what is the percentage yield and the mr of the ester?     percentage  yield  / % mr  a 62.5 48  b 75.0 48  c 62.5 88  d 75.0 88      40 which type of compound is made whe n a protein is hydrolysed?  a alkene  b amino acid  c carboxylic acid  d sugar   ",
            "15": "15       permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to tra ce copyright holders, but if any items requiring clearance have  unwittingly been included, the  publisher will be pleased to make amends at the earliest possib le opportunity.    to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced on line in the cambridge  assessment international educat ion copyright acknowledgements b ooklet. this is produced for eac h series of examinations and is  freely available to download  at www.cambridgeinternational.org  after the live examination se ries.   cambridge assessment international education is part of cambrid ge assessment. cambridge assessment is the brand name of the un iversity of cambridge  local examinations syndicate (ucles), which is a department of the university of cambridge.    \u00a9 ucles 2022 0620/23/m/j/22  blank page  ",
            "16": "16  \u00a9 ucles 2022 0620/23/m/j/22   groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv v vi vii viii 3 li lithium 74 be beryllium 9atomic number atomic symbolkey name relative atomic mass 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 2832 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordium \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganese 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitnerium \u201328 ni nickel 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtium \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl flerovium \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 3133 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 3234 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 4036 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r.t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americium \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrencium \u2013  "
        },
        "0620_s22_qp_31.pdf": {
            "1": "*6601588138* chemistry  0620/31 paper 3 theory (core) may/june 2022  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib22 06_0620_31/2rp \u00a9 ucles 2022 [turn overthis document has 20 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/31/m/j/22 \u00a9 ucles 2022 1 (a)  a list of symbols and formulae is shown. cao ch4 c2h4 c2h6 cl \u2013 cu2+ h2 he k+ n2 na+ so2   answer the following questions using these symbols or formulae.   each symbol or formula may be used once, more than once or not at all.   state which symbol or formula represents:  (i)  a compound produced by the thermal decomposition of calcium carbonate   ...   [1]  (ii)\t\ta\tpositive\tion\tthat\tgives\ta\tblue-green\tcolour\tin\ta\tflame\ttest   ...   [1]  (iii)  an element used as a fuel   ...   [1]  (iv)  the monomer used to produce poly(ethene)   ...   [1]  (v)  an ion formed when an atom gains an electron.   ...   [1]  (b)  complete the table to show the relative charges of a proton, a neutron and an electron. type of particle relative charge proton +1 neutron electron  [2]",
            "3": "3 0620/31/m/j/22 \u00a9 ucles 2022 [turn over  (c)  choose the two correct statements about nitrogen.   tick (\u2713) two boxes.  nitrogen molecules are monoatomic.  all nitrogen atoms have seven protons.  nitrogen atoms cannot be split into simpler substances by  chemical means.  all nitrogen atoms have 14 neutrons.  nitrogen is 21% of clean, dry air.  [2]  [total: 9]",
            "4": "4 0620/31/m/j/22 \u00a9 ucles 2022 2  the table shows the masses of some ions in a 1000 cm3 sample of toothpaste. name of ion formula of ionmass of ion in 1000 cm3 of toothpaste / g nh4+0.2 calcium ca2+1.2 cl \u20130.9 fluoride f\u20131.4 magnesium mg2+2.0 phosphate po43\u201324.4 sodium na+28.1 sulfate so42\u20139.2 tin( ii) sn2+0.2 zinc zn2+0.1  (a)  answer these questions using only the information in the table.  (i)  state which negative ion has the lowest mass in 1000 cm3 of toothpaste.   ...   [1]  (ii)  name the compound that contains nh4+ and cl \u2013 ions.   ...   [1]  (iii)  calculate the mass of phosphate ions in 250 cm3 of toothpaste.  mass = .. g  [1]  (b)  describe a test for sulfate ions.  test  .  observations  ..  [2]",
            "5": "5 0620/31/m/j/22 \u00a9 ucles 2022 [turn over  (c)  toothpaste also contains cinnamal.   the structure of cinnamal is shown. cc c hc ccchh h hh hc c oh   deduce the formula of cinnamal to show the number of atoms of carbon, hydrogen and oxygen.   ..   [1]  (d)  cinnamal can be oxidised to a carboxylic acid.  (i)  draw the structure of a carboxylic acid functional group to show all of the atoms and all of  the bonds.  [1]  (ii)  ethanoic acid is a carboxylic acid.   ethanoic acid reacts like a typical acid.   complete the word equation for the reaction of ethanoic acid with sodium carbonate. ethanoic acid+sodium carbonatesodium ethanoate+ +  [2]  [total: 9]",
            "6": "6 0620/31/m/j/22 \u00a9 ucles 2022 3  this question is about halogens and halogen compounds.  (a)  deduce the number of electrons, neutrons and protons in one atom of the isotope of chlorine  shown. 37cl17  number of electrons  ...  number of neutrons  ...  number of protons  .  [3]  (b)  state why chlorine is used in water treatment.   ..   [1]  (c)  aqueous chlorine reacts with aqueous potassium iodide.  (i)  complete the chemical equation for this reaction.  cl 2  +  .k i  \u2192  .kc l  +  i2 [2]  (ii)  explain in terms of the reactivity of the halogens why aqueous iodine does not react with  aqueous potassium chloride.   .   ...   [1]",
            "7": "7 0620/31/m/j/22 \u00a9 ucles 2022 [turn over  (d)  the table shows some properties of four halogens. halogenmelting point / \u00b0cboiling point / \u00b0cdensity of liquid at  boiling point in g / cm3 fluorine \u20132201.51 chlorine \u2013101 \u201335 bromine \u20137 59 3.12 iodine 114 184 4.93  (i)  complete the table by predicting:  \u25cf the boiling point of fluorine  \u25cf the density of liquid chlorine at its boiling point. [2]  (ii)  predict the physical state of chlorine at \u2013105 \u00b0c.   give a reason for your answer.   .   ...   [2]  [total: 11]",
            "8": "8 0620/31/m/j/22 \u00a9 ucles 2022 4  this question is about acids and bases.  (a)  describe the colour of methyl orange in acidic and alkaline solutions.  in acidic solution    in alkaline solution  .  [2]  (b)  complete the word equation for the reaction of hydrochloric acid with calcium oxide. hydrochloric acid+calcium oxide +  [2]  (c)  calcium oxide is lime.   give one use of lime.   ..   [1]  (d)  the reaction of hydrochloric acid with calcium oxide is exothermic.  (i)  state the meaning of the term exothermic.   ...   [1]  (ii)  the energy level diagram for the reaction of hydrochloric acid with calcium oxide is shown. energy progress of reactionreactants products   explain how the energy level diagram shows that this reaction is exothermic.   .   ...   [1]  [total: 7]",
            "9": "9 0620/31/m/j/22 \u00a9 ucles 2022 [turn over 5  this question is about group iv elements and their compounds.  (a)  the changes of state of lead are shown. solid leadmelting aliquid leadlead gasb condensing   name the changes of state represented by a and b.  a    b    [2]  (b)\t\tuse\tthe\tkinetic\tparticle\tmodel\tto\tdescribe\t the\tdifferences\t between\t liquid\tlead\tand\tlead\tgas\tin\t terms of:  \u25cf the separation of the particles          \u25cf the motion of the particles.  .        [4]  (c)  lead is extracted from lead( ii) oxide by heating with carbon. pbo  +  c  \u2192  pb  +  co   describe how this equation shows that lead( ii) oxide is reduced.      ..   [1]",
            "10": "10 0620/31/m/j/22 \u00a9 ucles 2022  (d)  lead is a pollutant of the air.  (i)  state one source of lead in the air.   ...   [1]  (ii)  state one\tadverse\teffect\tof\tlead\ton\thealth.   ...   [1]  (e)  diamond is a form of carbon.   the structure of diamond is shown.  (i)  choose the word which best describes the structure of diamond.   draw a circle around your chosen answer.  giant             ionic              metallic             simple [1]  (ii)  name the type of bonding in diamond.   ...   [1]  (iii)  give one use of diamond.   ...   [1]  (iv)  deduce the electronic structure of carbon.   use the periodic table to help you.   ...   [1]  [total: 13]",
            "11": "11 0620/31/m/j/22 \u00a9 ucles 2022 [turn over 6 (a)  the structures of four organic compounds, c, d, e and f, are shown. hch hch hch hho hhcbr hcbr hhhch hch hch hch hhch hchh hccd ef   answer the following questions about these compounds.   each compound may be used once, more than once or not at all.   state which compound, c, d, e or f:  (i)  decolourises aqueous bromine  .   [1]  (ii)  is an alcohol  ..   [1]  (iii)  is unsaturated  ...   [1]  (iv)  is in the same homologous series as ethane.  ..   [1]  (b)\t\tpetroleum\t is\ta\tmixture\tof\thydrocarbons\t which\tcan\tbe\tseparated\t into\tfractions\t with\tdifferent\t boiling points.   name the method used to separate these fractions.   ..   [1]  (c)  complete the table to show the name and uses of some petroleum fractions. name of fraction use of fraction refinery\tgas gasoline waxes and polishes  [3]",
            "12": "12 0620/31/m/j/22 \u00a9 ucles 2022  (d)  some hydrocarbons are formed by the process of cracking.  (i)  state the meaning of the term cracking .   .   .   ...   [2]  (ii)  describe the conditions needed for cracking.   .   ...   [2]  [total: 12]",
            "13": "13 0620/31/m/j/22 \u00a9 ucles 2022 [turn over 7  this question is about zinc and compounds of zinc.  (a)  zinc is a metal.   give three physical properties of metals.  1  .  2  .  3  .  [3]  (b)  zinc reacts with phosphorus to form zinc phosphide, zn3p2.   complete the equation for this reaction.  .zn  +  .p  \u2192  zn3p2 [2]  (c)  molten zinc chloride is electrolysed.   the incomplete apparatus is shown. +\u2013  (i)  complete the diagram by:  \u25cf completing the circuit to show the wires and power pack  \u25cf labelling the anode. [2]  (ii)  name the products formed at each electrode.  positive electrode    negative electrode  ..  [2]",
            "14": "14 0620/31/m/j/22 \u00a9 ucles 2022  (d)  zinc chloride reacts with water as shown. the solution formed is acidic. zncl 2  +  2h2o    zn(oh)2  +  2hcl  (i)  state the meaning of the symbol .   ...   [1]  (ii)  choose the ph value which is acidic.   draw a circle around your chosen answer.  ph 3          ph 7          ph 9          ph 14 [1]  (e)  a compound of zinc has the formula  znc4h10.   complete the table to calculate the relative molecular mass of znc4h10. atom number of atomsrelative atomic mass zinc 1 65 1 \u00d7 65 = 65 carbon 12 hydrogen 1  relative molecular mass = ..  [2]  [total: 13]",
            "15": "15 0620/31/m/j/22 \u00a9 ucles 2022 [turn over 8  a student investigates the reaction of large pieces of copper( ii) carbonate with dilute   hydrochloric acid. the hydrochloric acid is in excess. cuco3  +  2hcl  \u2192  cucl 2  +  co2  +  h2o   the rate of reaction is found by measuring the mass of the reaction mixture as time increases.   the results are shown on the graph. 181.20 181.00 180.80 180.60 180.40 180.20 180.00mass of reaction mixture  / g 02 04 06 0 time  / s80 100 120  (a)  deduce the mass of the reaction mixture at 30 s.  mass = .. g  [1]  (b)  the experiment is repeated using smaller pieces of copper( ii) carbonate.   all other conditions stay the same.   draw a line on the grid to show how the mass of the reaction mixture changes as time  increases. [2]",
            "16": "16 0620/31/m/j/22 \u00a9 ucles 2022  (c)\t\tdescribe\t the\teffect\teach\tof\tthe\tfollowing\t has\ton\tthe\trate\tof\treaction\t of\tcopper( ii) carbonate  with dilute hydrochloric acid.   all other conditions stay the same.  \u25cf the reaction is carried out in the presence of a catalyst.     \u25cf the reaction is carried out using a lower concentration of hydrochloric acid.     [2]  (d)  when 0.2 g of copper( ii) carbonate is used, 38 cm3 of carbon dioxide gas is produced.   calculate the volume of carbon dioxide gas produced when 0.50 g of copper( ii) carbonate is  used.   volume of carbon dioxide gas = .. cm3  [1]  [total: 6]",
            "17": "17 0620/31/m/j/22 \u00a9 ucles 2022blank page",
            "18": "18 0620/31/m/j/22 \u00a9 ucles 2022blank page",
            "19": "19 0620/31/m/j/22 \u00a9 ucles 2022blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge.",
            "20": "20 0620/31/m/j/22 \u00a9 ucles 2022 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s22_qp_32.pdf": {
            "1": "*6848782421* chemistry  0620/32 paper 3 theory (core) may/june 2022  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib22 06_0620_32/2rp \u00a9 ucles 2022 [turn overthis document has 20 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/32/m/j/22 \u00a9 ucles 2022 1 (a)  a list of symbols and formulae is shown. br \u2013 ch4 co2 cu2+ h2 k+ na+ n2 o2 u   answer the following questions using these symbols or formulae.   each symbol or formula may be used once, more than once or not at all.   state which symbol or formula represents:  (i)  a compound that is a product of respiration   ...   [1]  (ii)\t\tan\tion\tthat\tgives\ta\tlilac\tcolour\tin\ta\tflame \ttest   ...   [1]  (iii)  a gas which is 21% of clean, dry air   ...   [1]  (iv)  an element that has a radioactive isotope used as a source of energy   ...   [1]  (v)  an ion formed when an atom gains an electron.   ...   [1]  (b)  complete the table to show the relative masses of a proton, a neutron and an electron. type of particle relative mass proton 1 neutron electron  [2]",
            "3": "3 0620/32/m/j/22 \u00a9 ucles 2022 [turn over  (c)  choose the two correct statements about carbon dioxide.   tick (\u2713) two boxes.   carbon dioxide is a mixture of two elements.   carbon dioxide is an acidic oxide.   carbon dioxide has ionic bonding.   carbon dioxide has a giant covalent structure.   there are three atoms in a molecule of carbon dioxide.  [2]  [total: 9]",
            "4": "4 0620/32/m/j/22 \u00a9 ucles 2022 2  the table shows the masses of some ions in a 1000 cm3 sample of toothpaste. name of ion formula of ionmass of ion in 1000 cm3 of toothpaste / g ammonium nh4+0.5 calcium ca2+3.6 carbonate co32\u20132.5 chloride cl \u20130.9 fluoride f\u20131.2 mg2+0.2 phosphate po43\u201328.0 sodium na+32.0 so42\u201310.4 tin( ii) sn2+0.3  (a)  answer these questions using only the information in the table.  (i)  state which positive ion has the lowest mass in 1000 cm3 of toothpaste.   ...   [1]  (ii)  name the compound that contains mg2+ and so42\u2013 ions.   ...   [1]  (iii)  calculate the mass of sodium ions in 200 cm3 of toothpaste.  mass = .. g  [1]  (b)  describe a test for chloride ions.  test  .  observations  ..  [2]",
            "5": "5 0620/32/m/j/22 \u00a9 ucles 2022 [turn over  (c)  toothpaste also contains glycerol.   the structure of glycerol is shown. hch hoh hc oh hc oh   deduce the formula of glycerol to show the number of atoms of carbon, hydrogen and oxygen.   ..   [1]  (d)  glycerol is an alcohol.   ethanol is also an alcohol.  (i)  draw the structure of ethanol to show all of the atoms and all of the bonds.  [1]  (ii)  name the two products formed when ethanol undergoes complete combustion.    and  ...   [2]  (iii)  give one use of ethanol.   ...   [1]  [total: 10]",
            "6": "6 0620/32/m/j/22 \u00a9 ucles 2022 3  this question is about group i and group vii elements.  (a)  deduce the number of electrons, neutrons and protons in one atom of the isotope of potassium  shown. 40k19  number of electrons  ...  number of neutrons  ...  number of protons  .  [3]  (b)  complete the chemical equation for the reaction of potassium with water to form  potassium hydroxide and a gas which pops with a lighted splint.  2k  +  .h2o  \u2192  2koh  +  .. [2]  (c)  the table shows some properties of four group i elements. elementmelting point / \u00b0cboiling point / \u00b0crelative hardness lithium 181 1342 5.0 sodium8830.7 potassium 63 760 rubidium 39 686 0.2  (i)  complete the table by predicting:  \u25cf the melting point of sodium  \u25cf the relative hardness of potassium. [2]  (ii)  predict the physical state of potassium at 100 \u00b0c.   give a reason for your answer.   .   ...   [2]",
            "7": "7 0620/32/m/j/22 \u00a9 ucles 2022 [turn over  (d)  aqueous bromine reacts with aqueous potassium iodide. br2  +  2k i  \u2192  2kbr  +  i2  (i)  explain how this equation shows that bromine is more reactive than iodine.   .   ...   [1]  (ii)  state the colour of aqueous iodine.   ...   [1]  (e)  bromine is a diatomic molecule.   state the meaning of the term diatomic .   ..   [1]  (f)  bromine liquid turns into a gas very easily at room temperature.   choose the word which best describes a substance that evaporates easily.   draw a circle around your chosen answer.  conductor          flammable          malleable          volatile  [1]  [total: 13]",
            "8": "8 0620/32/m/j/22 \u00a9 ucles 2022 4  this question is about acids and bases.  (a)  name the type of chemical reaction which occurs when an acid reacts with a base.   ..   [1]  (b)  describe the colour of litmus in acidic and alkaline solutions.  in acidic solution    in alkaline solution  .  [2]  (c)  complete the word equation for the reaction of nitric acid with calcium hydroxide. nitric acid+calcium hydroxide +  [2]  (d)  when nitric acid reacts with calcium hydroxide, the temperature of the reaction mixture  increases.  (i)  choose the word which best describes this reaction.   draw a circle around your chosen answer.  decomposition          endothermic          exothermic          oxidation  [1]  (ii)  complete the energy level diagram for the reaction of nitric acid with calcium hydroxide by  writing the words:  \u25cf reactants  \u25cf products. energy progress of reaction  [1]  (e)  calcium hydroxide is slaked lime.   give one use of slaked lime.   ..   [1]  [total: 8]",
            "9": "9 0620/32/m/j/22 \u00a9 ucles 2022 [turn over 5  this question is about aluminium.  (a)  the changes of state of aluminium are shown. solid aluminiuma liquid aluminiumaluminium gas b   name the changes of state represented by a and b.  a    b    [2]  (b)\t\tuse\tthe\tkinetic\tparticle\tmodel\tto\tdescribe\t the\tdifferences\t between\t solid\taluminium\t and\tliquid\t aluminium in terms of:  \u25cf the arrangement of the particles  .        \u25cf the separation of the particles.  ...        [4]  (c)  aluminium ore contains aluminium oxide.  (i)  name the main ore of aluminium.   ...   [1]  (ii)  aluminium is extracted from aluminium oxide by electrolysis.   explain why aluminium is extracted by electrolysis and not by reduction with carbon.   .   ...   [1]",
            "10": "10 0620/32/m/j/22 \u00a9 ucles 2022  (d)  aluminium can be used to reduce iron( iii) oxide to iron. fe2o3  +  2a l  \u2192  2fe  +  al 2o3   describe how this equation shows that iron( iii) oxide is reduced.   ..   [1]  (e)  aluminium is used for electric cables.   state one other use of aluminium.   give a reason for this use in terms of the properties of aluminium.  use of aluminium  ...  reason for this use  .     [2]  (f)  deduce the electronic structure of aluminium.   use the periodic table to help you.   ..   [1]  [total: 12]",
            "11": "11 0620/32/m/j/22 \u00a9 ucles 2022 [turn over 6 (a)  the structures of four organic compounds, c, d, e and f, are shown. hhch hch hch hch hch h hhch hch hch hhch hhch co ohcd ef cch hh h  (i)  state which  two of the compounds, c, d, e and f, are in the same homologous series.   and  ...   [1]  (ii)  state which compound, c, d, e or f, is the monomer used to make poly(ethene).   ...   [1]  (iii)  state which compound, c, d, e or f, is a carboxylic acid.   ...   [1]  (b)  petroleum is a mixture of hydrocarbons, which can be separated into fractions.   describe how petroleum is separated into fractions to include:  \u25cf the name of the process used to separate the fractions     \u25cf how this process separates the different fractions.                 [4]",
            "12": "12 0620/32/m/j/22 \u00a9 ucles 2022  (c)  complete the table to show the name and uses of some petroleum fractions. name of fraction use of fraction naphtha diesel oil (gas oil) making roads  [3]  [total: 10]",
            "13": "13 0620/32/m/j/22 \u00a9 ucles 2022 [turn over 7  this question is about sodium and compounds of sodium.  (a)  sodium is a metal in group i of the periodic table.  (i)  give two physical properties of all metals.  1  ..  2  ..  [2]  (ii)  give one\tphysical\t property\t of\tgroup\ti\tmetals\tthat\tis\tdifferent\t from\tmost\tother\tmetals\tand\t state\thow\tit\tis\tdifferent.   .   ...   [1]  (b)  sodium reacts with oxygen to form sodium oxide, na2o.   complete the chemical equation for this reaction.  .na  +  o2  \u2192  .na2o [2]  (c)  the diagram shows the apparatus used to electrolyse molten sodium iodide. power supply + \u2013  (i)  complete the diagram by labelling:  \u25cf the electrolyte  \u25cf the cathode.  [2]  (ii)  name the products formed at each electrode.  positive electrode    negative electrode  ..  [2]",
            "14": "14 0620/32/m/j/22 \u00a9 ucles 2022  (d)  a compound of sodium has the formula na2s2o3.   complete the table to calculate the relative molecular mass of na2s2o3. atom number of atomsrelative atomic mass sodium 2 23 2 \u00d7 23 = 46 sulfur 32 oxygen 16  relative molecular mass = ..  [2]  [total: 11]",
            "15": "15 0620/32/m/j/22 \u00a9 ucles 2022 [turn over 8  a student investigates the reaction of small pieces of calcium carbonate with dilute hydrochloric acid.  the hydrochloric acid is in excess. caco3  +  2hcl  \u2192  cacl 2  +  co2  +  h2o   the rate of reaction is found by measuring the volume of carbon dioxide gas produced as time  increases.   the results are shown on the graph. 60 50 40 30 20 10 0volume of carbon dioxide / cm3 01 02 03 0 time  / s40 50 60 70  (a)  deduce the volume of carbon dioxide gas at 35 s.  volume = .. cm3  [1]  (b)  the experiment is repeated at a higher temperature.   all other conditions stay the same.   draw a line on the grid to show how the volume of carbon dioxide gas produced changes as  time increases. [2]",
            "16": "16 0620/32/m/j/22 \u00a9 ucles 2022  (c)\t\tdescribe\t the\teffect\teach\tof\tthe\tfollowing\t has\ton\tthe\trate\tof\treaction\t of\tcalcium\tcarbonate\t with\t dilute hydrochloric acid.   all other conditions stay the same.  \u25cf the reaction is carried out using a higher concentration of hydrochloric acid.     \u25cf the reaction is carried out using powdered calcium carbonate.     [2]  (d)  when 0.11 g of calcium carbonate is used, 25 cm3 of carbon dioxide gas is produced.   calculate the mass of calcium carbonate needed to produce 100 cm3 of carbon dioxide gas.  mass of calcium carbonate = .. g  [1]  (e)  state one use of calcium carbonate.   ..   [1]  [total: 7]",
            "17": "17 0620/32/m/j/22 \u00a9 ucles 2022blank page",
            "18": "18 0620/32/m/j/22 \u00a9 ucles 2022blank page",
            "19": "19 0620/32/m/j/22 \u00a9 ucles 2022blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge.",
            "20": "20 0620/32/m/j/22 \u00a9 ucles 2022 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s22_qp_33.pdf": {
            "1": "*8643090581* chemistry  0620/33 paper 3 theory (core) may/june 2022  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib22 06_0620_33/3rp \u00a9 ucles 2022 [turn overthis document has 20 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/33/m/j/22 \u00a9 ucles 2022 1 (a)  a list of symbols and formulae is shown. al 2o3 c2h5oh co2 fe2o3 h2 he k+ li+ n2 na+ o2\u2013   answer the following questions using these symbols or formulae.   each symbol or formula may be used once, more than once or not at all.   state which symbol or formula represents:  (i)  an element that is monoatomic   ...   [1]  (ii)\t\tan\tion\tthat\tgives\ta\tred\tcolour\tin\ta\tflame\t test   ...   [1]  (iii)  an element that can be used as a fuel   ...   [1]  (iv)  a gas that contributes to climate change   ...   [1]  (v)  an ion that is formed when an atom gains electrons.   ...   [1]  (b)  complete the table to show the relative charges of a proton, neutron and electron. type of particle relative charge proton neutron 0 electron  [2]",
            "3": "3 0620/33/m/j/22 \u00a9 ucles 2022 [turn over  (c)  choose the two correct statements about nitrogen and hydrogen in a mixture.   tick (\u2713) two boxes.   the nitrogen and hydrogen mixture can be separated by physical means.   the nitrogen and hydrogen mixture is liquid at room temperature.   the atoms of nitrogen and hydrogen in the mixture are chemically combined.   air is mainly a mixture of nitrogen and hydrogen.   the bonding in both nitrogen and hydrogen molecules is covalent.  [2]  [total: 9]",
            "4": "4 0620/33/m/j/22 \u00a9 ucles 2022 2  the table shows the masses of some ions in a 1000 cm3 sample of toothpaste. name of ion formula of ionmass of ion in 1000 cm3 of toothpaste / g nh4+0.2 calcium ca2+0.8 co32\u20130.7 chloride cl \u20130.9 fluoride f\u20132.2 magnesium mg2+2.0 phosphate po43\u201324.4 sodium na+34.2 sulfate so42\u201310.1 tin( ii) sn2+0.4 zinc zn2+0.1  (a)  answer these questions using only the information in the table.  (i)  state which negative ion has the highest mass in 1000 cm3 of toothpaste.   ...   [1]  (ii)  name the compound that contains nh4+ and co32\u2013 ions.   ...   [1]  (iii)\t\tcalculate\tthe\tmass\tof\tfluoride\tions\tin\t250\t cm3 of toothpaste.  mass = .. g  [1]  (b)  describe the observations when aqueous ammonia is added drop by drop to a solution  containing zinc ions until the ammonia is in excess.   observations with a few drops of ammonia      observations with ammonia in excess     [2]",
            "5": "5 0620/33/m/j/22 \u00a9 ucles 2022 [turn over  (c)  toothpaste also contains compound a.   the structure of compound a is shown. hch hh hc oh hc oh   deduce the formula of compound a to show the number of atoms of carbon, hydrogen and  oxygen.   ..   [1]  (d)  compound a is an alcohol.   ethanoi, c2h5oh, is also an alcohol.  (i)  complete these sentences about ethanol using words from the list. different       formula       group       identical       molecule       similar   ethanol is part of the alcohol homologous series.   each member of the alcohol homologous series has the same functional ... .   members of the same homologous series have chemical properties that are ... .  [2]  (ii)  when ethanol undergoes incomplete combustion, a small amount of carbon dioxide is  produced.   name two other substances that are produced when ethanol undergoes incomplete  combustion.   and  ...   [2]  [total: 10]",
            "6": "6 0620/33/m/j/22 \u00a9 ucles 2022 3  this question is about group i and group vii elements.  (a)  deduce the number of electrons, neutrons and protons in one atom of the isotope of sodium  shown. 23na11  number of electrons  ...  number of neutrons  ...  number of protons  .  [3]  (b)  sodium reacts with chlorine to produce sodium chloride.  (i)  state the colour of chlorine gas.   ...   [1]  (ii)  chlorine is a diatomic molecule.   state the meaning of the term diatomic .   ...   [1]  (iii)  complete the chemical equation for the reaction of sodium with chlorine.  2na  +  ..  \u2192  .nac l [2]  (iv)  sodium chloride is an ionic compound.   describe two physical properties of ionic compounds.  1  ..  2  ..  [2]",
            "7": "7 0620/33/m/j/22 \u00a9 ucles 2022 [turn over  (c)  the table shows some properties of four group i elements. elementmelting point / \u00b0cboiling point / \u00b0catomic radius / nm lithium 181 1342 0.157 sodium 98 883 potassium760 0.235 rubidium 39 686 0.250  (i)  complete the table by predicting:  \u25cf the melting point of potassium  \u25cf the atomic radius of sodium. [2]  (ii)  predict the physical state of rubidium at 700 \u00b0c.   give a reason for your answer.   .   ...   [2]  (iii)  give two\tphysical\t properties\t of\tgroup\ti\tmetals\tthat\tare\tdifferent\t from\ttransition\t elements\t and\tstate\thow\tthey\tare\tdifferent.  1  ..   .  2  ..   .  [2]  (d)  aqueous chlorine reacts with aqueous sodium iodide. cl 2  +  2nai  \u2192  2nacl  +  i2   explain how this equation shows that chlorine is more reactive than iodine.      ..   [1]  [total: 16]",
            "8": "8 0620/33/m/j/22 \u00a9 ucles 2022 4  this question is about acids and carbonates.  (a)  describe the colour change when excess acid is added to a solution of methyl orange in  alkaline solution.  from  to     [2]  (b)  complete the word equation for the reaction of hydrochloric acid with calcium carbonate. hydrochloric acid+calcium carbonate + + water  [2]  (c)  calcium carbonate decomposes when heated. calcium carbonate  \u2192  calcium oxide  +  carbon dioxide  (i)  calcium carbonate is used in the manufacture of lime (calcium oxide).   state one other use of calcium carbonate.   ...   [1]  (ii)  the decomposition of calcium carbonate is endothermic.   state the meaning of the term endothermic.   ...   [1]  (iii)  the energy level diagram for the decomposition of calcium carbonate is shown. energy progress of reactioncaco3cao  +  co2   explain how the energy level diagram shows that this reaction is endothermic.   .   ...   [1]",
            "9": "9 0620/33/m/j/22 \u00a9 ucles 2022 [turn over  (iv)\t\twhen\t0.50\tg\tof\tcalcium\tcarbonate\t decomposes,\t 120\tcm3 of carbon dioxide gas is produced.   calculate the volume of carbon dioxide gas produced when 0.10 g of calcium carbonate is  used.  volume of carbon dioxide gas = .. cm3  [1]  [total: 8]",
            "10": "10 0620/33/m/j/22 \u00a9 ucles 2022 5  this question is about group vi elements and their compounds.  (a)  name the changes of physical state when:  \u25cf oxygen gas is converted to liquid oxygen     \u25cf solid sulfur is converted directly to sulfur gas.     [2]  (b)\t\tuse\tthe\tkinetic\tparticle\tmodel\tto\tdescribe\t the\tdifferences\t between\t solid\tsulfur\tand\tsulfur\tgas\t in terms of:  \u25cf the arrangement of the particles          \u25cf the motion of the particles.          [4]  (c)  deduce the electronic structure of sulfur.   use the periodic table to help you.   ..   [1]  (d)  sulfur is used in the manufacture of sulfuric acid.   the equation shows one of the reactions. 2so2  +  o2    2so3  (i)  state the meaning of the symbol .   ...   [1]  (ii)  give one use of sulfur dioxide other than in making sulfuric acid.   ...   [1]",
            "11": "11 0620/33/m/j/22 \u00a9 ucles 2022 [turn over  (e)  acid rain is formed when sulfur dioxide reacts with water vapour in the atmosphere.  (i)  choose the ph value which is acidic.   draw a circle around your chosen answer.  ph 4          ph 7          ph 10          ph 14  [1]  (ii)  describe one\teffect\tof\tacid\train\ton\tbuildings.   ...   [1]  [total: 11]",
            "12": "12 0620/33/m/j/22 \u00a9 ucles 2022 6 (a)  the structures of four organic compounds, b, c, d and e, are shown. hhch hch hch h hhch hch hoh hch co oh cch h hh ch hbc de  (i)  state which compound, b, c, d or e, dissolves in water to form an acidic solution.   ...   [1]  (ii)  state which compound, b, c, d or e, is a saturated hydrocarbon.   ...   [1]  (iii)  state which compound, b, c, d or e, is an unreactive compound except in terms of burning.   ...   [1]  (iv)  state which compound, b, c, d or e, decolourises aqueous bromine.   ...   [1]  (b)  ethanol can be manufactured from ethene and one other reactant.   describe the manufacture of ethanol from ethene to include:  \u25cf the formula of ethene     \u25cf the name of the other reactant     \u25cf the conditions needed.        [4]",
            "13": "13 0620/33/m/j/22 \u00a9 ucles 2022 [turn over  (c)  complete the table to show the name and uses of some petroleum fractions. name of fraction use of fraction making chemicals kerosene fuel oil  [3]  [total: 11]",
            "14": "14 0620/33/m/j/22 \u00a9 ucles 2022 7  this question is about lithium and compounds of lithium.  (a)  lithium reacts with nitrogen to produce lithium nitride, li3n.   complete the chemical equation for this reaction.  .li  +  n2  \u2192  .li3n [2]  (b)  molten lithium bromide is electrolysed using carbon electrodes.   the apparatus is shown. power supply \u2013 +  (i)  complete the diagram by labelling:  \u25cf the anode  \u25cf the electrolyte. [2]  (ii)  name the products formed at each electrode.  positive electrode    negative electrode  ..  [2]  (iii)  the carbon electrodes conduct electricity.   give one other property that these electrodes must have.   ...   [1]",
            "15": "15 0620/33/m/j/22 \u00a9 ucles 2022 [turn over  (c)  a compound of lithium has the formula c3h5o2li2.   complete the table to calculate the relative molecular mass of c3h5o2li2. atom number of atomsrelative atomic mass carbon 3 12 3 \u00d7 12 = 36 hydrogen 1 oxygen 16 lithium 7  relative molecular mass = ..  [2]  [total: 9]",
            "16": "16 0620/33/m/j/22 \u00a9 ucles 2022 8  a student investigates the rate of decomposition of aqueous hydrogen peroxide using 0.2 g of a  catalyst. 2h2o2  \u2192  2h2o  +  o2   the rate of reaction is found by measuring the volume of oxygen gas produced as time increases.   the results are shown on the graph. 60 50 40 30 20 10 0volume of oxygen gas produced  / cm3 01 02 03 0 time  / s40 50 60 70  (a)\t\tdeduce\tthe\ttime\ttaken\tto\tcollect\t35\t cm3 of oxygen gas.  time = .. s  [1]  (b)  the experiment is repeated using 0.2 g of smaller pieces of the catalyst.   all other conditions stay the same.   draw a line on the grid to show how the volume of oxygen gas produced changes as time  increases.  [2]",
            "17": "17 0620/33/m/j/22 \u00a9 ucles 2022 [turn over  (c)\t\tdescribe\t the\teffect\teach\tof\tthe\tfollowing\t has\ton\tthe\trate\tof\tdecomposition\t of\thydrogen\t peroxide.   all other conditions stay the same.  \u25cf the reaction is carried out at a higher temperature.     \u25cf the reaction is carried out using a lower concentration of hydrogen peroxide.     [2]  (d)  hydrogen peroxide reduces sodium chlorate( i), nacl o, to sodium chloride. h2o2  +  nacl o  \u2192  nacl  +  h2o  +  o2   describe how this equation shows that sodium chlorate( i) has been reduced.   ..   [1]  [total: 6]",
            "18": "18 0620/33/m/j/22 \u00a9 ucles 2022blank page",
            "19": "19 0620/33/m/j/22 \u00a9 ucles 2022blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge.",
            "20": "20 0620/33/m/j/22 \u00a9 ucles 2022 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s22_qp_41.pdf": {
            "1": "*8032813939* chemistry  0620/41 paper 4 theory (extended) may/june 2022  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib22 06_0620_41/4rp \u00a9 ucles 2022 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/41/m/j/22 \u00a9 ucles 2022 1  a list of substances is shown.  aluminium oxide carbon dioxide chlorine diamond ethanol  glucose iron( iii) oxide limestone nitrogen oxygen   answer the questions using the list of substances.   each substance may be used once, more than once or not at all.   state which of the substances:  (a)  is a reactant in photosynthesis   ..   [1]  (b)  is the main constituent of bauxite   ..   [1]  (c)  are two products of fermentation   and  ..   [2]  (d)  is used as a fuel   ..   [1]  (e)  is a gas used to convert iron into steel   ..   [1]  (f)  is a greenhouse gas   ..   [1]  (g)  is a gas that is approximately 78% of clean, dry air   ..   [1]  (h)  is a form of carbon.   ..   [1]  [total: 9]",
            "3": "3 0620/41/m/j/22 \u00a9 ucles 2022 [turn over 2 (a)  atoms are made of protons, neutrons and electrons. atoms of the same element are known as  isotopes.  (i)  complete the table. particle relative charge relative mass electron1 1840 neutron proton +1  [2]  (ii)  24mg12  and 25mg12  are isotopes of magnesium.   complete the table to show the numbers of electrons, neutrons and protons in these  isotopes of magnesium. isotopenumber of electronsnumber of neutronsnumber of protons 24mg12 25mg12  [2]  (iii)  explain why magnesium ions have a charge of 2+.   .   ...   [1]  (b)  mg2+ ions have the electronic structure 2,8.   give the formula of the following particles which have the same electronic structure as mg2+  ions.  \u25cf a cation (positive ion)     \u25cf an anion (negative ion)     \u25cf an atom     [3]  [total: 8]",
            "4": "4 0620/41/m/j/22 \u00a9 ucles 2022 3  this question is about sodium and compounds of sodium.  (a) (i)  describe the bonding in a metallic element such as sodium.  you may include a diagram as part of your answer.   .   .   ...   [3]  (ii)  describe how solid sodium conducts electricity.   ...   [1]  (b)  some properties of sodium chloride are shown:  \u25cf melting point of 801 \u00b0c  \u25cf non-conductor of electricity when solid  \u25cf conductor of electricity when molten  \u25cf soluble in water.  (i)  name the type of bonding in sodium chloride.   ...   [1]  (ii)  explain why sodium chloride conducts electricity when molten.   .   ...   [1]",
            "5": "5 0620/41/m/j/22 \u00a9 ucles 2022 [turn over  (c)  a student determines the concentration of a solution of dilute sulfuric acid, h2so4, by titration  with aqueous sodium hydroxide, naoh.  step 1  25.0 cm3 of 0.200 mol / dm3 naoh is transferred into a conical flask.  step 2  three drops of methyl orange indicator are added to the conical flask.  step 3  a burette is filled with h2so4.  step 4  the acid in the burette is added to the conical flask until the indicator changes colour.   the volume of acid is recorded. this process is known as titration.  step 5  the titration is repeated several times until a suitable number of results is obtained.  (i)  name the piece of apparatus used to measure exactly 25.0 cm3 of 0.200 mol / dm3 naoh  in step 1.   ...   [1]  (ii)  state the colour change of the methyl orange indicator in step 4.  from . to     [1]  (iii)  state how the student decides that a suitable number of results have been obtained.   .   ...   [1]  (iv)  20.0 cm3 of h2so4 reacts with 25.0 cm3 of 0.200 mol / dm3 naoh.   the equation for the reaction is shown. h2so4  +  2naoh  \u2192  na2so4  +  2h2o   calculate the concentration of h2so4 using the following steps.  \u25cf calculate the number of moles in 25.0 cm3 of 0.200 mol / dm3 naoh.  .. mol  \u25cf determine the number of moles of h2so4 that react with the naoh.  .. mol  \u25cf calculate the concentration of h2so4.  .. mol / dm3  [3]  [total: 12]",
            "6": "6 0620/41/m/j/22 \u00a9 ucles 2022 4  this question is about compounds of sulfur.  (a)  sulfuric acid, h2so4, is manufactured using the contact process. this manufacture involves  four stages.  stage 1  molten sulfur burns in air to produce sulfur dioxide.  stage 2  sulfur dioxide reacts with oxygen to form sulfur trioxide.  stage 3  sulfur trioxide combines with concentrated sulfuric acid to form oleum, h2s2o7.  stage 4  oleum reacts to form concentrated sulfuric acid.  (i)  write a chemical equation for the reaction occurring in stage 1.   ...   [1]  (ii)  state the essential conditions that are necessary for stage 2. write an equation for the  chemical reaction that occurs.   .   .   .   ...   [4]  (iii)  write a chemical equation for the reaction occurring in stage 3.   ...   [1]  (iv)  name the substance that reacts with oleum in stage 4.   ...   [1]  (b)  hydrogen sulfide has the formula h2s.  (i)  complete the dot-and-cross diagram to show the electron arrangement in a molecule of  hydrogen sulfide. show outer shell electrons only. s h h  [2]  (ii)  balance the chemical equation for the reaction of hydrogen sulfide with sulfur dioxide  shown.  .h2s  +  so2  \u2192  .s  +  .h2o [1]  [total: 10]",
            "7": "7 0620/41/m/j/22 \u00a9 ucles 2022 [turn over 5  ethanoic acid is manufactured by the reaction of methanol with carbon monoxide.   an equilibrium mixture is produced. ch3oh(g)  +  co(g)    ch3cooh(g)  (a)  state two characteristics of an equilibrium.  1  .  2  .  [2]  (b)  the purpose of the industrial process is to produce a high yield of ethanoic acid at a high rate  of reaction.   the manufacture is carried out at a temperature of 300 \u00b0c.   the forward reaction is exothermic.   use this information to state why the manufacture is not carried out at temperatures:  \u25cf below  300 \u00b0c     \u25cf above 300 \u00b0c.     [2]  (c)  complete the table using only the words increases , decreases  or no change . effect on the rate of the forward reactioneffect on the equilibrium yield of ch3cooh(g) adding a catalyst no change decreasing the pressure  [3]  (d)  suggest which of the following metals is a suitable catalyst for the reaction. give a reason for  your answer. aluminium         calcium         cobalt         magnesium         potassium   suitable catalyst  .   reason    [2]",
            "8": "8 0620/41/m/j/22 \u00a9 ucles 2022  (e)  ethanoic acid is a member of the homologous series of carboxylic acids.   state the general formula of this homologous series.   ..   [1]  (f)  draw the structure of the carboxylic acid containing three carbon atoms. show all of the atoms  and all of the bonds.  [2]  (g)  when carboxylic acids react with alcohols, esters are produced.   the formula of ester x is ch3ch2ch2cooch3.  (i)  name ester x.   ...   [1]  (ii)  give the name of the carboxylic acid and the alcohol that react together to produce ester x.  carboxylic acid    alcohol    [2]  (h)  ester y has the following composition by mass:  c, 48.65%;  h, 8.11%;  o, 43.24%.   calculate the empirical formula of ester y.  empirical formula = ..  [3]",
            "9": "9 0620/41/m/j/22 \u00a9 ucles 2022 [turn over  (i)  ester z has the empirical formula c2h4o and a relative molecular mass of 88.   determine the molecular formula of ester z.  molecular formula = ..  [1]  [total: 19]",
            "10": "10 0620/41/m/j/22 \u00a9 ucles 2022 6  this question is about zinc and its compounds.  (a)  zinc is extracted from its ore which is mainly zinc sulfide, zns.   the steps for this extraction are shown.  step 1  zinc sulfide is converted into zinc oxide.  step 2  the zinc oxide is then reduced to zinc in a furnace. the zinc formed becomes a gas.  step 3  the zinc gas is cooled to form molten zinc.  (i)  name the ore of zinc, which is mainly zinc sulfide.   ...   [1]  (ii)  describe how zinc sulfide is converted into zinc oxide in step 1.   .   ...   [1]  (iii)  name the reducing agent used in step 2.   ...   [1]  (iv)  explain why the zinc forms a gas in step 2 inside the furnace.   ...   [1]  (v)  state the name of the physical change occurring when zinc gas is converted into molten  zinc.   ...   [1]  (b)  zinc sulfate crystals, znso4\u20227h2o, are hydrated.   zinc sulfate crystals are made by reacting zinc carbonate with dilute sulfuric acid.   the equation for the overall process is shown. znco3  +  h2so4  +  6h2o  \u2192  znso4\u20227h2o  +  co2  step 1  large pieces of solid zinc carbonate are added to dilute sulfuric acid until the zinc  carbonate is in excess. this forms aqueous zinc sulfate.  step 2  the excess zinc carbonate is separated from the aqueous zinc sulfate.  step 3  the aqueous zinc sulfate is heated until a saturated solution is formed.  step 4  the saturated solution is allowed to cool and crystallise.  step 5  the crystals are removed and dried.",
            "11": "11 0620/41/m/j/22 \u00a9 ucles 2022 [turn over  (i)  in step 1, zinc carbonate is in excess when no more zinc carbonate dissolves.   state one other observation that indicates the zinc carbonate is in excess in step 1.   ...   [1]  (ii)  name a different substance, other than zinc carbonate, that can be added to dilute  sulfuric acid to produce aqueous zinc sulfate in step 1.   ...   [1]  (iii)  step 1 is repeated using powdered zinc  carbonate instead of large pieces.   all other conditions are kept the same.   the rate of reaction increases.   give a reason why the rate of reaction increases. explain your answer in terms of particles.   .   .   ...   [2]  (iv)  suggest what is observed when the solution is saturated in step 3.   .   .   ...   [1]  (v)  the formula of zinc sulfate crystals is znso4\u20227h2o.   give the formula of the solid formed if the crystals are heated to dryness in step 3.   ...   [1]  [total: 11]",
            "12": "12 0620/41/m/j/22 \u00a9 ucles 2022 7  the periodic table can be used to classify elements.  (a)  group i elements react with cold water to form alkaline solutions.  (i)  place the group i elements caesium, lithium, potassium, rubidium and sodium in their  order of reactivity with water.   put the most reactive element first. most reactive least reactive  [1]  (ii)  name the alkaline solution formed when caesium reacts with cold water.   ...   [1]  (b)  group i elements have lower melting points than transition elements.   describe one other difference in the physical properties of group i elements and transition  elements.   ..   [1]  (c)  group vii elements are known as the halogens.   astatine is below iodine in group vii.   predict the physical state of astatine at room temperature and pressure.   ..   [1]  (d)  some group vii elements react with aqueous solutions containing halide ions.   when aqueous chlorine is added to aqueous potassium bromide a reaction occurs.   the ionic half-equations for the reaction are shown. cl 2(aq)  +  2e\u2013  \u2192  2cl \u2013(aq)   2br \u2013(aq)  \u2192  br2(aq)  +  2e\u2013  (i)  describe the colour change of the solution.  original colour of potassium bromide solution    final colour of reaction mixture    [2]",
            "13": "13 0620/41/m/j/22 \u00a9 ucles 2022 [turn over  (ii)  identify the species that is oxidised.   explain your decision.  species oxidised  .  explanation  .  [2]  (e)  bromine monochloride, brcl, is made by the reaction between bromine and chlorine. the  chemical equation is shown. br2(g)  +  cl 2(g)  \u2192  2brcl (g) bond bond energy in kj / mol br\u2013br 190 cl \u2013cl 242 br\u2013cl 218   calculate the overall energy change for the reaction using bond energies.   use the following steps.  \u25cf calculate the total amount of energy required to break the bonds in 1 mole of br2(g) and  1 mole of cl 2(g).  .. kj  \u25cf calculate the total amount of energy released when the bonds in 2 moles of brcl (g) are  formed.  .. kj  \u25cf calculate the overall energy change for the reaction.  .. kj / mol   [3]  [total: 11]",
            "14": "14 0620/41/m/j/22 \u00a9 ucles 2022blank page",
            "15": "15 0620/41/m/j/22 \u00a9 ucles 2022permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge.blank page",
            "16": "16 0620/41/m/j/22 \u00a9 ucles 2022 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s22_qp_42.pdf": {
            "1": "*6148594183* chemistry  0620/42 paper 4 theory (extended) may/june 2022  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib22 06_0620_42/3rp \u00a9 ucles 2022 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/42/m/j/22 \u00a9 ucles 2022 1  the symbols of the elements of period 3 of the periodic table are shown. na mg al si p s cl ar   answer the following questions about these elements.   each symbol may be used once, more than once or not at all.   write the symbol of the element which:  (a)  forms a stable ion with a 2+ charge  .   [1]  (b)  is the least reactive in the period  .   [1]  (c)  is used in water treatment  ...   [1]  (d)  forms an oxide which is the main impurity in iron ore  ..   [1]  (e)  is an important component of fertilisers  ...   [1]  (f)  is stored under oil     [1]  (g)  is used in food containers     [1]  (h)  is found in the ore zinc blende.     [1]  [total: 8]",
            "3": "3 0620/42/m/j/22 \u00a9 ucles 2022 [turn over question 2 starts on the next page.",
            "4": "4 0620/42/m/j/22 \u00a9 ucles 2022 2  calcium hydroxide, ca(oh)2, is slightly soluble in water.  (a)  calcium hydroxide can be made by the reaction of calcium with water.  (i)  write the chemical equation for this reaction.   ...   [2]  (ii)  name another substance that reacts with water to form calcium hydroxide.   ...   [1]  (b)  when calcium hydroxide dissolves in water, it dissociates into ions and forms a weakly alkaline  solution.  (i)  suggest the ph of aqueous calcium hydroxide.   ...   [1]  (ii)  give the formula of the ion responsible for making the solution alkaline.   ...   [1]  (c)  limewater is a saturated solution of calcium hydroxide, ca(oh)2(aq).  (i)  name the gas limewater is used to test for.   ...   [1]  (ii)  suggest what is meant by the term saturated solution .   .   ...   [2]  (iii)  describe how you would make a sample of limewater starting with solid calcium hydroxide.   .   .   ...   [2]  (iv)  describe how you would test for the presence of calcium ions in a sample of limewater.  test  ..  observations  ...   .  [3]",
            "5": "5 0620/42/m/j/22 \u00a9 ucles 2022 [turn over  (d)  a 25.0 cm3 sample of limewater is placed in a conical flask. the concentration of ca(oh)2 in the  limewater is determined by titration with dilute hydrochloric acid, hc l.  (i)  name the item of apparatus used to measure the volume of acid in this titration.   ...   [1]  (ii)  state the type of reaction which takes place.   ...   [1]  (iii)  as well as limewater and dilute hydrochloric acid, state what other type of substance must  be added to the conical flask.   ...   [1]  (iv)  the equation for the reaction is shown. ca(oh)2  +  2hcl  \u2192  cacl 2  +  2h2o   20.0 cm3 of 0.0500 mol / dm3 hcl reacts with the 25.0 cm3 of ca(oh)2.   determine the concentration of ca(oh)2 in g / dm3. use the following steps.  \u25cf calculate the number of moles in 20.0 cm3 of 0.0500 mol / dm3 hcl.  .. mol  \u25cf determine the number of moles of ca(oh)2 in 25.0 cm3 of the limewater.  .. mol  \u25cf calculate the concentration of ca(oh)2 in mol / dm3.  .. mol / dm3  \u25cf determine the concentration of ca(oh)2 in g / dm3.  .. g / dm3  [5]  [total: 21]",
            "6": "6 0620/42/m/j/22 \u00a9 ucles 2022 3  transition elements are found in the middle block of the periodic table.  (a)  chromium has several isotopes. manganese has only one isotope.  (i)  state what is meant by the term isotopes.   .   ...   [2]  (ii)  state the nucleon number of manganese.   ...   [1]  (iii)  complete the table to show the number of protons, neutrons and electrons in a 52cr3+ 24  ion. protons neutrons electrons  [3]  (b)  one chemical property of transition elements is that they form coloured compounds.  (i)  give the colours of the following hydrated salts.  \u25cf hydrated copper( ii) sulfate  ..  \u25cf hydrated cobalt( ii) chloride  .  [2]  (ii)  state two other chemical properties of transition elements.  1  ..  2  ..  [2]  (c)  transition elements and group i elements are metals. they share many physical properties  including the ability to:  \u25cf conduct electricity  \u25cf be hammered into shape.  (i)  explain why transition elements and group i elements conduct electricity.   ...   [1]  (ii)  state the property that describes a material which can be hammered into shape.   ...   [1]",
            "7": "7 0620/42/m/j/22 \u00a9 ucles 2022 [turn over  (d)  transition elements and group i elements differ in other physical properties. transition  elements are harder and stronger than group i elements.   describe two other ways in which the physical properties of transition elements differ from  group i elements.  1  .  2  .  [2]  [total: 14]",
            "8": "8 0620/42/m/j/22 \u00a9 ucles 2022 4  fluorine and chlorine are halogens.  (a)  suggest the appearance of fluorine.   ..   [1]  (b)  fluorine reacts with sulfur to form a compound which has 25.2% sulfur by mass and a relative  molecular mass of 254.   determine the molecular formula of this compound.  molecular formula = ..  [3]  (c)  nitrogen trichloride, nc l 3, is a covalent compound.   complete the dot-and-cross diagram to show the electron arrangement in a molecule of ncl 3.   show outer electrons only. n cl clcl  [3]",
            "9": "9 0620/42/m/j/22 \u00a9 ucles 2022 [turn over  (d)  lithium chloride, lic l, is an ionic compound.   complete the dot-and-cross diagram to show the electron arrangement and charges of the  ions in lithium chloride. . cl. li  [3]  (e)  explain, in terms of attractive forces between particles, why licl is a solid at room temperature  but ncl 3 is a liquid with a relatively low boiling point.         ..   [3]  [total: 13]",
            "10": "10 0620/42/m/j/22 \u00a9 ucles 2022 5  the reaction scheme shows five organic reactions, numbered 1 to 5. carbon dioxide + water ethanol sugar alkene a alkane b compound c2 51 3 4  (a)  name reaction 1.   ..   [1]  (b)  name reaction 2 and write the chemical equation for this reaction.  name  ..  equation  .  [3]  (c)  reaction 3 forms ethanol from alkene a.  (i)  identify alkene a.   ...   [1]  (ii)  state the type of reaction that occurs during reaction 3.   ...   [1]  (iii)  state the reagents and conditions needed for reaction 3.   .   ...   [2]  (d)  alkene a is converted into alkane b in reaction 4.  (i)  state the reagent and conditions for reaction 4.   .   ...   [3]  (ii)  state the general formula of alkanes.   ...   [1]",
            "11": "11 0620/42/m/j/22 \u00a9 ucles 2022 [turn over  (e)  ethanol is oxidised in reaction 5 by heating it with dilute sulfuric acid and one other reagent.  (i)  identify the other reagent in reaction 5.   ...   [1]  (ii)  name the homologous series compound  c belongs to.   ...   [1]  (iii)  draw the structure of compound c.   show all of the atoms and all of the bonds.  [1]  [total: 15]",
            "12": "12 0620/42/m/j/22 \u00a9 ucles 2022 6  this question is about polymers.  (a)  polymer x is a condensation polymer.   part of the structure of polymer x is shown. coo coo coo  (i)  how many molecules of water are produced when this part of polymer x is formed from its  monomers?   ...   [1]  (ii)  complete the structures of the two monomers used to make polymer x.   show all of the atoms and all of the bonds in the functional groups. and  [2]  (iii)  what type of condensation polymer is x?   ...   [1]  (b)  part of polymer y has the structure shown. co oo co coo   state the number of different types of monomer needed to make polymer y.   ..   [1]",
            "13": "13 0620/42/m/j/22 \u00a9 ucles 2022 [turn over  (c)  part of polymer z has the structure shown. cch3 ch3 hch h cch3 ch3 hccch3 ch3 hch  (i)  draw and name the structure of the monomer which forms polymer z.   show all of the atoms and all of the bonds.  name ...  [3]  (ii)  name the chemical process used to make the monomer that forms polymer z.   ...   [1]  [total: 9]",
            "14": "14 0620/42/m/j/22 \u00a9 ucles 2022blank page",
            "15": "15 0620/42/m/j/22 \u00a9 ucles 2022permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge.blank page",
            "16": "16 0620/42/m/j/22 \u00a9 ucles 2022 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s22_qp_43.pdf": {
            "1": "*3760474789* chemistry  0620/43 paper 4 theory (extended) may/june 2022  1 hour 15 minutes you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 80.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf the periodic table is printed in the question paper. ib22 06_0620_43/2rp \u00a9 ucles 2022 [turn overthis document has 16 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/43/m/j/22 \u00a9 ucles 2022 1  a list of substances is shown.  aluminium oxide carbon dioxide carbon monoxide chlorine copper  glucose iron( iii) oxide limestone nitrogen oxygen   answer the questions using the substances in the list.   each substance may be used once, more than once or not at all.   state which substance is:  (a)  a product of respiration   ..   [1]  (b)  the main constituent of hematite   ..   [1]  (c)  an element which has a sulfate that is used to test for water   ..   [1]  (d)  a colourless toxic gas   ..   [1]  (e)  a reactant in fermentation   ..   [1]  (f)  a reducing agent in the extraction of iron   ..   [1]  (g)  a conductor of electricity when solid   ..   [1]  (h)  a gas that is approximately 21% of clean, dry air.   ..   [1]  [total: 8]",
            "3": "3 0620/43/m/j/22 \u00a9 ucles 2022 [turn over 2 (a) 32s16 and 33s16 are isotopes of sulfur.   use your knowledge of protons, neutrons and electrons to answer the following questions.  (i)\t\tdescribe\thow\tthese\tisotopes\tof\tsulfur\tare\tthe\tsame\tand\thow\tthey\tare\tdifferent.  same  ...   . \t different\t  ...   .  [3]  (ii)  explain why each of these isotopes have an overall charge of zero.   .   ...   [1]  (iii)  explain why both isotopes have the same chemical properties.   .   ...   [1]  (b)\t\tsulfide\tions,\ts2\u2013, have the electronic structure 2,8,8.  (i)\t\texplain\twhy\tsulfide\tions\thave\ta\tcharge\t of\t2\u2013.   .   ...   [1]  (ii)  give the formula of:  \u25cf an anion which has the same electronic structure as s2\u2013   .  \u25cf a cation which has the same electronic structure as s2\u2013.   .  [2]  [total: 8]",
            "4": "4 0620/43/m/j/22 \u00a9 ucles 2022 3  this question is about nitrogen and compounds of nitrogen.  (a)  nitrogen molecules have the formula n2.   some properties of nitrogen are shown:  \u25cf melting point of \u2013210 \u00b0c  \u25cf boiling point of \u2013196 \u00b0c  \u25cf non-conductor of electricity when solid  \u25cf insoluble in water.  (i)  name the type of bonding between the atoms in an n2 molecule.   ...   [1]  (ii)  explain, in terms of attractive forces between particles, why nitrogen has a low melting  point.   .   ...   [1]  (iii)  explain why nitrogen does not conduct electricity.   .   ...   [1]  (b)  nitrogen reacts with hydrogen to form ammonia, nh3, in the haber process.   state the essential conditions in the haber process. write an equation for the chemical reaction.               ..   [4]  (c)  ammonia is made in the laboratory by heating ammonium chloride with calcium hydroxide.   balance the chemical equation for the reaction.  .nh4cl  +  ca(oh)2  \u2192  .nh3  +  cacl 2  +  .h2o [1]",
            "5": "5 0620/43/m/j/22 \u00a9 ucles 2022 [turn over  (d)  hydrazine, n2h4, is another compound that contains nitrogen and hydrogen.   complete the dot-and-cross diagram to show the electron arrangement in a molecule of  hydrazine. show outer electrons only. n hh n hh  [2]  (e)  ammonia and hydrazine are weak bases.   the chemical equation for the reaction between one molecule of ammonia and one molecule  of water is shown. nh3  +  h2o    nh4+  +  oh\u2013  (i)  state the meaning of the term base.   ...   [1]  (ii)  write a chemical equation for the reaction between one molecule of hydrazine, n2h4, and  one molecule of water.   ...   [1]  [total: 12]",
            "6": "6 0620/43/m/j/22 \u00a9 ucles 2022 4  ethanol is made industrially by the reaction of ethene with steam. the reaction occurs at a  temperature of 300 \u00b0c and a pressure of 60 atmospheres. c2h4(g)  +  h2o(g)    c2h5oh(g)   a catalyst is used in this reaction.   the forward reaction is exothermic.  (a)  state what is meant by the term catalyst.      ..   [2]  (b)  complete the table using only the words increases , decreases  or no change . effect\ton\tthe\trate\tof the forward reactioneffect\ton\tthe\tequilibrium yield of c2h5oh(g) increasing the temperature decreasing the pressure  [4]  (c)  ethanol is a member of the alcohol homologous series.   members of the same homologous series have the same general formula.  (i)  state the general formula of alcohols.   ...   [1]  (ii)  state two general characteristics, other than the same general formula, of all homologous  series.  1  ..  2  ..  [2]",
            "7": "7 0620/43/m/j/22 \u00a9 ucles 2022 [turn over  (iii)  one alcohol containing three carbon atoms is propan-1-ol.   draw the structure of one other alcohol containing three carbon atoms. show all of the  atoms and all of the bonds.   name the alcohol you have drawn.  name  ...  [2]  (d)  when alcohols react with carboxylic acids, esters are produced.  (i)  the structure of ester x is shown. o ohch hch hch hc h hh hh cc   name ester x.   ...   [1]  (ii)  give the name of the alcohol and the carboxylic acid that react together to produce ester x.  alcohol    carboxylic acid    [2]  (e)  ester y has the following composition by mass:  c, 58.82%;  h, 9.80%;  o, 31.37%.   calculate the empirical formula of ester y.  empirical formula = ..  [3]",
            "8": "8 0620/43/m/j/22 \u00a9 ucles 2022  (f)  ester z has the empirical formula c3h6o and a relative molecular mass of 116.   calculate the molecular formula of ester z.  molecular formula = ..  [1]  [total: 18]",
            "9": "9 0620/43/m/j/22 \u00a9 ucles 2022 [turn over 5  this question is about copper and its compounds.  (a)  describe the bonding in a metallic element such as copper.   you may include a diagram as part of your answer.         ..   [3]  (b)  a metal spoon is electroplated with copper.   state what is used as:  the positive electrode (anode)  ...  the negative electrode (cathode)  ...  the electrolyte.  ...  [3]",
            "10": "10 0620/43/m/j/22 \u00a9 ucles 2022  (c)  the formula for crystals of hydrated copper( ii) sulfate is cuso4\u20225h2o.   hydrated copper( ii) sulfate is made by reacting copper( ii) oxide with dilute sulfuric acid.   the overall equation is shown. cuo  +  h2so4  +  4h2o  \u2192  cuso4\u20225h2o   the crystals are made using the following steps:  step 1  50.0 cm3 of 0.200 mol / dm3 dilute sulfuric acid is heated in a beaker. powdered  copper( ii) oxide is added until the copper( ii) oxide is in excess. aqueous  copper( ii) sulfate is formed.  step 2  the excess copper( ii) oxide is separated from the aqueous copper( ii) sulfate.  step 3  the aqueous copper( ii) sulfate is heated until a saturated solution is formed.  step 4  the saturated solution is allowed to cool and crystallise.  step 5  the crystals are removed and dried.   calculate the maximum mass of copper( ii) sulfate crystals, cuso4\u20225h2o, that can form using  the following steps.  \u25cf calculate the number of moles of h2so4 in 50.0 cm3 of 0.200 mol / dm3 h2so4.  .. mol  \u25cf deduce the number of moles of cuso4\u20225h2o that can form.  .. mol  \u25cf the mr of cuso4\u20225h2o is 250.   calculate the maximum mass of cuso4\u20225h2o that can form.  .. g  [3]",
            "11": "11 0620/43/m/j/22 \u00a9 ucles 2022 [turn over  (d)  state one observation that indicates the copper( ii) oxide is in excess in step 1.   ..   [1]  (e)  step 1 is repeated without heating the dilute sulfuric acid.   all other conditions are kept the same.   the rate of reaction decreases.   give a reason why the rate of reaction decreases. explain your answer in terms of particles.               ..   [3]  (f)  name a substance, other than copper( ii) oxide, that can be added to dilute sulfuric acid to  produce copper( ii) sulfate in step 1.   ..   [1]  (g)  name the process used to separate excess copper( ii) oxide from aqueous copper( ii) sulfate  in step 2.   ..   [1]  (h)  suggest what is meant by the term saturated solution  in step 3.         ..   [2]  (i)\t\tthe\tphrase\t\u2018heating\tto\tdryness\u2019 \tmeans\theating\tuntil\tno\tmore\twater\tis\tgiven\toff.   explain why aqueous copper( ii) sulfate is not heated to dryness in step 3.      ..   [1]  [total: 18]",
            "12": "12 0620/43/m/j/22 \u00a9 ucles 2022 6  the periodic table can be used to classify elements.  (a)  the group i metals react with cold water. transition elements do not react with cold water.  (i)  describe two other\tdifferences\t in\tthe\tchemical properties between group i metals and  transition elements.  1  ..  2  ..  [2]  (ii)  describe the observations when potassium is added to cold water. write a balanced  equation for the reaction. include state symbols.  observations  ...   .   .   .  equation  ..  [5]  (b)  transition elements are stronger than group i metals.   describe two other\tdifferences\t in\tthe\tphysical properties of group i metals and transition  elements.  1  .  2  .  [2]  (c)  some group vii elements react with aqueous solutions containing halide ions.   when aqueous bromine is added to aqueous potassium iodide a reaction occurs.   the ionic half-equations for the reaction are shown. br2(aq)  +  2e\u2013  \u2192  2br \u2013(aq) 2i\u2013(aq)  \u2192  i2(aq)  +  2e\u2013  (i)  describe the colour change of the solution.  original colour of potassium iodide solution   \t final\tcolour\tof\treaction\tmixture\t    [2]",
            "13": "13 0620/43/m/j/22 \u00a9 ucles 2022 [turn over  (ii)  state the name of the general term given to the type of reaction in which electrons are  transferred from one species to another.   ...   [1]  (iii)  identify the oxidising agent in this reaction. give a reason for your answer.  oxidising agent    reason  .  [2]  (d)  use the key to complete the table to show the results of adding aqueous halogens to aqueous  solutions of halides. one has been completed for you. halides key \u2713 = reaction \u2717 = no reactionkcl (aq) kbr(aq) ki(aq) halogenscl 2(aq) br2(aq) \u2713 i2(aq)  [2]  [total: 16]",
            "14": "14 0620/43/m/j/22 \u00a9 ucles 2022blank page",
            "15": "15 0620/43/m/j/22 \u00a9 ucles 2022permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge.blank page",
            "16": "16 0620/43/m/j/22 \u00a9 ucles 2022 groupthe periodic table of elements 1 h hydrogen 12 he helium 4ii i iii iv vv iv ii viii 3 li lithium 74 be berylliu m 9atomic number atomic symbolkey name relative atomic mas s 11 na sodium 2312 mg magnesium 24 19 k potassium 3920 ca calcium 40 37 rb rubidium 8538 sr strontium 88 55 cs caesium 13356 ba barium 137 87 fr francium \u201388 ra radium \u20135 b boron 11 13 al aluminium 27 31 ga gallium 70 49 in indium 115 81 tl thallium 2046 c carbon 12 14 si silicon 28 32 ge germanium 73 50 sn tin 119 82 pb lead 20722 ti titanium 48 40 zr zirconium 91 72 hf hafnium 178 104 rf rutherfordiu m \u201323 v vanadium 51 41 nb niobium 93 73 ta tantalum 181 105 db dubnium \u201324 cr chromium 52 42 mo molybdenum 96 74 w tungsten 184 106 sg seaborgium \u201325 mn manganes e 55 43 tc technetium \u2013 75 re rhenium 186 107 bh bohrium \u201326 fe iron 56 44 ru ruthenium 101 76 os osmium 190 108 hs hassium \u201327 co cobalt 59 45 rh rhodium 103 77 ir iridium 192 109 mt meitneriu m \u201328 ni nicke l 59 46 pd palladium 106 78 pt platinum 195 110 ds darmstadtiu m \u201329 cu copper 64 47 ag silver 108 79 au gold 197 111 rg roentgenium \u201330 zn zinc 65 48 cd cadmium 112 80 hg mercury 201 112 cn copernicium \u2013114 fl fleroviu m \u2013116 lv livermorium \u20137 n nitrogen 14 15 p phosphorus 31 33 as arsenic 75 51 sb antimony 122 83 bi bismuth 2098 o oxygen 16 16 s sulfur 32 34 se selenium 79 52 te tellurium 128 84 po polonium \u20139 f fluorine 19 17 cl chlorine 35.5 35 br bromine 80 53 i iodine 127 85 at astatine \u201310 ne neon 20 18 ar argon 40 36 kr krypton 84 54 xe xenon 131 86 rn radon \u201321 sc scandium 45 39 y yttrium 89 57\u201371 lanthanoids 89\u2013103 actinoids 57 la lanthanum 139 89 aclanthanoids actinoids the volume of one mole of any gas is 24  dm3 at room temperature and pressure (r .t.p.).actinium \u201358 ce cerium 140 90 th thorium 23259 pr praseodymium 141 91 pa protactinium 23160 nd neodymium 144 92 u uranium 23861 pm promethium \u2013 93 np neptunium \u201362 sm samarium 150 94 pu plutonium \u201363 eu europium 152 95 am americiu m \u201364 gd gadolinium 157 96 cm curium \u201365 tb terbium 159 97 bk berkelium \u201366 dy dysprosium 163 98 cf californium \u201367 ho holmium 165 99 es einsteinium \u201368 er erbium 167 100 fm fermium \u201369 tm thulium 169 101 md mendelevium \u201370 yb ytterbium 173 102 no nobelium \u201371 lu lutetium 175 103 lr lawrenciu m \u2013"
        },
        "0620_s22_qp_51.pdf": {
            "1": "*3888579013* chemistry  0620/51 paper 5 practical test may/june 2022  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib22 06_0620_51/2rp \u00a9 ucles 2022 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/51/m/j/22 \u00a9 ucles 2022 1  you are going to investigate the rate at which hydrogen gas is made when magnesium reacts with  two different solutions of dilute hydrochloric acid, c and d, with different concentrations. the dilute  hydrochloric acid is in excess in both experiments.   read all of the instructions carefully before starting the experiments.   instructions   you are going to do two experiments using the apparatus shown. trough waterclamp inverted 100  cm3 measuring cylinde r conical flask dilute hydrochloric acidbungrubber delivery tube  (a) experiment 1  \u25cf use a measuring cylinder to pour 50 cm3 of dilute hydrochloric acid c into a conical flask.  \u25cf use a thermometer to measure the initial temperature of the dilute hydrochloric acid.  record the initial temperature in the space provided.  \u25cf set the apparatus up as shown in the diagram, ensuring the inverted measuring cylinder  is full of water.  \u25cf remove the bung from the conical flask, leaving the delivery tube in the measuring cylinder.  \u25cf add a coiled 5 cm length of magnesium ribbon to the conical flask, immediately replace  the bung and start the timer.  \u25cf measure the volume of gas collected in the inverted measuring cylinder every 20 seconds  for 160 seconds. record the volume of gas collected in the table.  \u25cf use the thermometer to measure the final temperature of the dilute hydrochloric acid in the  conical flask. record the final temperature in the space provided.  initial temperature ... \u00b0c final temperature ... \u00b0c time / s 20 40 60 80 100 120 140 160 volume of gas collected / cm3  [2]  (b)  experiment 2  \u25cf empty and rinse the conical flask with distilled water.  \u25cf repeat experiment 1 using 50 cm3 of dilute hydrochloric acid d instead of dilute  hydrochloric acid c.  initial temperature ... \u00b0c final temperature ... \u00b0c time / s 20 40 60 80 100 120 140 160 volume of gas collected / cm3  [3]",
            "3": "3 0620/51/m/j/22 \u00a9 ucles 2022 [turn over  (c)  complete a suitable scale on the y-axis and plot your results from experiments 1 and 2 on the  grid.   draw two smooth line graphs. the lines must pass through (0,0). clearly label your lines. 00 20 40 60 80 time  / svolume of ga s collected  / cm3 100 120 140 160  [5]",
            "4": "4 0620/51/m/j/22 \u00a9 ucles 2022  (d)  from your graph, deduce the volume of gas that was collected after 50 seconds in  experiment 2.   show clearly on the grid  how you worked out your answer.  volume of gas = ..  [3]  (e)  explain what can be deduced about the concentrations of dilute hydrochloric acid c and dilute  hydrochloric acid d.            ..   [2]  (f) (i)  state what happens to the temperature of the dilute hydrochloric acid during experiment 1.    ...   [1]  (ii)  state what effect this temperature change has on the total volume of gas made when the  reaction has finished.    ...   [1]  (iii)  describe a change that can be made to the apparatus or reagents to reduce the temperature  change of the acid in experiment 1.    ...   [1]  (g)  suggest why it is important to replace the bung in the conical flask immediately after adding  the magnesium ribbon.      ..   [1]  (h)  state the advantage of measuring the volume of gas collected every 10 seconds rather than  every 20 seconds.   ..   [1]  [total: 20]",
            "5": "5 0620/51/m/j/22 \u00a9 ucles 2022 [turn over 2  you are provided with two substances, solid e and solution f.   do the following tests, recording all of your observations at each stage.   tests on solid e   add about 15 cm3 of distilled water to the boiling tube containing solid e. replace the stopper in the  boiling tube and shake the boiling tube to dissolve solid e and form solution e. divide solution e  into three approximately equal portions in one boiling tube and two test-tubes.  (a)  to the first portion of solution e in the boiling tube, add aqueous sodium hydroxide dropwise  until it is in excess.   keep the mixture formed for (b).   record your observations.      ..   [2]  (b)  gently warm the mixture formed in (a). test any gas produced and identify the gas.   record your observations.        identity of gas    [2]  (c)  to the second portion of solution e add about 1 cm depth of dilute nitric acid followed by a few  drops of aqueous silver nitrate.   record your observations.   ..   [1]  (d)  to the third portion of solution e add about 1 cm depth of dilute nitric acid followed by a few  drops of aqueous barium nitrate.   record your observations.   ..   [1]  (e)  identify the three ions in solution e.         ..   [3]",
            "6": "6 0620/51/m/j/22 \u00a9 ucles 2022  tests on solution f   divide solution f into two approximately equal portions in two test-tubes.  (f)  test the ph of the first portion of solution f.  ph = ..  [1]  (g)  add the second portion of solution f to the boiling tube containing solid sodium carbonate. test  any gas produced.   record your observations.         ..   [3]  (h)  identify the positive ion in solution f.   ..   [1]  [total: 14]",
            "7": "7 0620/51/m/j/22 \u00a9 ucles 2022 [turn over 3  a sample of muddy river water contains water, dissolved solids and insoluble solid mud.   plan an investigation to find the concentration of dissolved solids, in g / dm3, in the river water.   in your answer state how you will work out the concentration of the dissolved solids in g / dm3.   you are provided with a small sample (less than 1 dm3) of muddy river water and common laboratory  apparatus.   (1 dm3 = 1000 cm3)    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    ...    .   [6]",
            "8": "8 0620/51/m/j/22 \u00a9 ucles 2022blank page",
            "9": "9 0620/51/m/j/22 \u00a9 ucles 2022blank page",
            "10": "10 0620/51/m/j/22 \u00a9 ucles 2022blank page",
            "11": "11 0620/51/m/j/22 \u00a9 ucles 2022notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/51/m/j/22 \u00a9 ucles 2022tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge."
        },
        "0620_s22_qp_52.pdf": {
            "1": "*5311402242* chemistry  0620/52 paper 5 practical test may/june 2022  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib22 06_0620_52/2rp \u00a9 ucles 2022 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/52/m/j/22 \u00a9 ucles 2022 1\t\tyou\tare\tgoing\tto\tinvestigate\t the\treaction\tbetween\ttwo\tdifferent\tsolutions\tof\taqueous\tsodium\tcarbonate,\t labelled\tsolution\t k\tand\tsolution\t l,\tand\tdilute\thydrochloric\tacid\tusing\ttwo\tdifferent\tindicators.   read all of the instructions carefully before starting the experiments.   instructions \t\tyou\tare\tgoing\tto\tdo\ttwo\texperiments.  (a) experiment 1  \u25cf rinse a burette with water and then with the dilute hydrochloric acid for question 1 .  \u25cf\tfill\tthe\tburette\twith\tthe\tdilute\thydrochloric\t acid.\trun\tsome\tof\tthe\tdilute\thydrochloric\t acid\t out\tof\tthe\tburette\tso\tthat\tthe\tlevel\tof\tthe\tdilute\thydrochloric\t acid\tis\ton\tthe\tburette\tscale.\t record\tthe\tburette\treading\tin\tthe\ttable.  \u25cf\tuse\ta\tmeasuring\tcylinder\tto\tpour\t25\t cm3 of\tsolution\tk\tinto\ta\tconical\tflask.  \u25cf\tadd\tfive\tdrops\tof\tmethyl\torange\tindicator\t and\tfive\tdrops\tof\tthymolphthalein\t indicator\tto\t the\tconical\tflask.  \u25cf\tstand\tthe\tconical\tflask\ton\ta\twhite\ttile.  \u25cf\tslowly\tadd\tdilute\thydrochloric\t acid\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tswirling\tthe\t flask,\tuntil\tthe\tsolution\tbecomes\tyellow.\tthis\tis\tthe\tfirst\tcolour\tchange.\trecord\tthe\tburette\t reading\tin\tthe\ttable.  \u25cf\tcontinue\tto\tadd\tdilute\thydrochloric\t acid\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tswirling\t the\tflask,\tuntil\tthe\tsolution\tchanges\tcolour\tagain.\t this\tis\tthe\tsecond\tcolour\tchange.  \u25cf\trecord\tthe\tburette\treading\tin\tthe\ttable\tand\tcomplete\tthe\ttable. experiment\t1 burette\treading\tat\tfirst\tcolour\tchange\t /\tcm3 final\tburette\treading\tat\tsecond\tcolour\tchange\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tdilute\thydrochloric\tacid\tadded\tfor\tfirst\t colour\tchange\t /\tcm3 total\tvolume\tof\tdilute\thydrochloric\tacid\tadded\tfor\t second\tcolour\tchange\t /\tcm3  [3]  (b) experiment 2  \u25cf\tempty\tthe\tconical\tflask\tand\trinse\tit\twith\tdistilled\twater.  \u25cf\trepeat\texperiment\t1\tusing\tsolution\t l\tinstead\tof\tsolution\t k. experiment\t2 burette\treading\tat\tfirst\tcolour\tchange\t /\tcm3 final\tburette\treading\tat\tsecond\tcolour\tchange\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tdilute\thydrochloric\tacid\tadded\tfor\tfirst\t colour\tchange\t /\tcm3 total\tvolume\tof\tdilute\thydrochloric\tacid\tadded\tfor\t second\tcolour\tchange\t /\tcm3  [3]",
            "3": "3 0620/52/m/j/22 \u00a9 ucles 2022 [turn over  (c)\t\tstate\tthe\tsecond\tcolour\tchange\tobserved\tin\tthe\tconical\tflask\tin\tboth\texperiments. \t from\t\tto\t \t \t\t[1]  (d)\t\tfor\texperiment\t 1,\tcompare\tthe\tvolume\tof\tdilute\thydrochloric\t acid\tneeded\tfor\tthe\tfirst\tcolour\t change\twith\tthe\tvolume\tof\tdilute\thydrochloric\tacid\tfor\tthe\tsecond\tcolour\tchange.  \t  \t.. \t\t[2]  (e)\t\tcompare\tthe\tconcentration\t of\tsolution\t k\tused\tin\texperiment\t 1\tto\tthe\tconcentration\t of\tsolution\t l  used\tin\texperiment\t2. \t\texplain\tyour\tanswer.  \t  \t  \t..   [3]  (f) (i)\t\tdeduce\tthe\tvolume\tof\tdilute\thydrochloric\t acid\tneeded\tfor\tthe\tsecond\tcolour\tchange\twhen\t experiment\t2\tis\trepeated\tusing\t50\t cm3\tof\tsolution\tl.  \t ... \t\t[2]  (ii)\t\tstate\twhy\tusing\t50\t cm3\tof\tsolution\tl\twould\tcause\ta\tproblem.  \t .  \t ... \t\t[1]  (g)\t\tstate\tthe\tadvantage\t of\tusing\ta\tpipette\tinstead\tof\tthe\tmeasuring\t cylinder\tin\tthese\texperiments.  \t.. \t\t[1]  (h)\t\texplain\twhy\tthe\tconical\tflask\twas\tswirled\tas\tthe\tdilute\thydrochloric\t acid\twas\tadded\tfrom\tthe\t burette.  \t  \t.. \t\t[1]",
            "4": "4 0620/52/m/j/22 \u00a9 ucles 2022  (i)\t\tat\tthe\tstart\tof\texperiment\t 1,\tthe\tburette\twas\trinsed\twith\twater\tand\tthen\twith\tdilute\t hydrochloric\tacid. \t\tat\tthe\tstart\tof\texperiment\t2,\tthe\tconical\tflask\twas\trinsed\twith\twater\tbut\t not\twith\tsolution\t l.  (i)\t\texplain\twhy\tthe\tconical\tflask\twas\trinsed \twith\twater.  \t .  \t ... \t\t[1]  (ii)\t\texplain\twhy\tthe\tconical\tflask\twas\t not\trinsed\twith\tsolution\t l\tin\texperiment\t2.  \t .  \t ... \t\t[1] \t [total:\t19]",
            "5": "5 0620/52/m/j/22 \u00a9 ucles 2022 [turn over 2\t\tyou\tare\tprovided\twith\tsolid\t m. \t\tdo\tthe\tfollowing\ttests\ton\tsolid\t m,\trecording\tall\tof \tyour\tobservations\tat\teach\tstage.  tests on solid m \t\tadd\tabout\t15\tcm3\tof\tdistilled\twater\tto\tthe\tboiling\ttube\tcontaining\t solid\t m.\tstopper\tthe\tboiling\ttube\tand\t shake\tthe\tmixture\tto\tdissolve\tsolid\t m\tand\tform\tsolution\t m.\tdivide\tsolution\t m\tinto\tfive\tapproximately\t equal\tportions\tin\tfive\ttest\u2011tubes.  (a)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tm. \t ph\t=\t..\t[1]  (b)\t\tto\tthe\tsecond\tportion\tof\tsolution\t m\tadd\taqueous\tsodium\thydroxide\t gradually\t until\tit\tis\tin\t excess\tand\tthe\ttest\u2011tube\tis\tat\tleast\thalf\tfull.   keep the product for use in (c). \t\trecord\tyour\tobservations.  \t  \t.. \t\t[2]  (c) (i)\t\ttransfer\tthe\tproduct\tfrom\t (b)\tinto\ta\tboiling\ttube.\tadd\ta\tpiece\tof\taluminium\t foil\tand\twarm\t the\tmixture\tgently.\t test\tany\tgas\tproduced. \t \trecord\tyour\tobservations.  \t .  \t ... \t\t[2]  (ii)\t\tidentify\tthe\tgas\tmade\tin\t(i).  \t ... \t\t[1]  (d)\t\tto\tthe\tthird\tportion\tof\tsolution\t m\tadd\tabout\t1\tcm\tdepth\tof\tdilute\tnitric\tacid\tfollowed\tby\ta\tfew\t drops\tof\taqueous\tbarium\tnitrate. \t\trecord\tyour\tobservations.  \t.. \t\t[1]",
            "6": "6 0620/52/m/j/22 \u00a9 ucles 2022  (e) (i)\t\tto\tthe\tfourth\tportion\tof\tsolution\t m\tadd\tthe\tzinc\tpowder.\tgently\tshake\tthe\ttest\u2011tube\tand\t then\tleave\tit\tto\tstand\tand\tsettle\tfor\tabout\t5\tminutes.   keep the product for use in (ii). \t \trecord\tyour\tobservations.  \t .  \t ... \t\t[1]  (ii)\t\tdecant\tthe\tsolution\tformed\tin\t (i)\tinto\ta\ttest\u2011tube. \t \tadd\taqueous\tammonia\tgradually\tto\tthe\t solution\tuntil\tthere\tis\tno\tfurther\tchange. \t \trecord\tyour\tobservations.  \t .  \t ... \t\t[2]  (f) (i)\t\tto\tthe\tfifth\tportion\tof\tsolution\t m\tadd\tthe\taqueous\tpotassium\tiodide.   keep the product for use in (ii). \t \trecord\tyour\tobservations.  \t ... \t\t[1]  (ii)\t\tto\tthe\tproduct\tfrom\t(i)\tadd\tthe\taqueous \tsodium\tthiosulfate.\tgently\tshake\tthe\ttest\u2011tube. \t \tas\tsoon\tas\tyou\thave\tmade\tyour\tobservations\t pour\tthe\tcontents\tof\tthe\ttest\u2011tube\tinto\tthe\t \u2018stop\u2011bath\u2019. \t \trecord\tyour\tobservations.  \t ... \t\t[1]  (g)\t\tuse\tthe\tresults\tof\tthe\ttests\tin\t(a) to (d)\tto\tidentify\tthree\tions\tin\tsolution\t m.  \t  \t..   [3] \t [total:\t15]",
            "7": "7 0620/52/m/j/22 \u00a9 ucles 2022 [turn over 3\t\tthe\tdiagram\tshows\tsome\tcoffee\tbeans. \t\tcaffeine\toccurs\tnaturally\tin\tcoffee\tbeans.\tcaffeine\tis\ta\twhite\tcrystalline\t solid.\tit\tis\tvery\tsoluble\tin\t hot\twater\tbut\tmuch\tless\tsoluble\tin\tcold\twater. \t\tplan\tan\tinvestigation\tto\tobtain\ta\tpure\tcrystalline\t sample\tof\tcaffeine\tfrom\tcoffee\tbeans. \t\tassume\tthat\tall\tother\tsoluble\tsubstances\t in\tcoffee\tbeans\tare\tvery\tsoluble\tin\tboth\thot\tand\tcold\t water. \t\tyou\tare\tprovided\twith\tcoffee\tbeans\tand\tcommon \tlaboratory\tapparatus.  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t .   [6]",
            "8": "8 0620/52/m/j/22 \u00a9 ucles 2022blank page",
            "9": "9 0620/52/m/j/22 \u00a9 ucles 2022blank page",
            "10": "10 0620/52/m/j/22 \u00a9 ucles 2022blank page",
            "11": "11 0620/52/m/j/22 \u00a9 ucles 2022notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/52/m/j/22 \u00a9 ucles 2022tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge."
        },
        "0620_s22_qp_53.pdf": {
            "1": "*0341990977* chemistry  0620/53 paper 5 practical test may/june 2022  1 hour 15 minutes you must answer on the question paper. you will need: the materials and apparatus listed in the confidential instructions instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ].  \u25cf notes for use in qualitative analysis are provided in the question paper. ib22 06_0620_53/2rp \u00a9 ucles 2022 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122 for examiner\u2019s use 1 2 3 total",
            "2": "2 0620/53/m/j/22 \u00a9 ucles 2022 1\t\tyou\tare\tgoing\tto\tinvestigate\t the\treaction\tbetween\taqueous\tsodium\thydroxide\t and\ttwo\tdifferent\t solutions\t of\tdilute\thydrochloric\t acid\twith\tdifferent\tconcentrations,\t labelled\t q and r,\tusing\ttwo\t different\tindicators.   read all of the instructions carefully before starting the experiments.   instructions \t\tyou\tare\tgoing\tto\tdo\tthree\texperiments.  (a) experiment 1  \u25cf fill the burette with dilute hydrochloric acid q.\t run\tsome\tof\tthe\tdilute\thydrochloric\t acid\t out\tof\tthe\tburette\tso\tthat\tthe\tlevel\tof\tthe\tdilute\thydrochloric\t acid\tis\ton\tthe\tburette\tscale.\t record\tthe\tburette\treading\tin\tthe\ttable.  \u25cf use a measuring cylinder to pour 25 cm3 of the aqueous sodium hydroxide for  question 1 \tinto\ta\tconical\tflask.  \u25cf\tadd\tfive\tdrops\tof\tmethyl\torange\tindicator\tto\tthe\tconical\tflask.  \u25cf\tstand\tthe\tconical\tflask\ton\ta\twhite\ttile.  \u25cf\tslowly\tadd\tdilute\thydrochloric\t acid\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tswirling\tthe\t flask,\tuntil\tthe\tsolution\tjust\tchanges\tcolour.  \u25cf\trecord\tthe\tburette\treading\tin\tthe\ttable\tand\tcomplete\tthe\ttable. experiment 1 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of dilute hydrochloric acid q\tadded\t/\tcm3  experiment 2  \u25cf\tempty\tthe\tconical\tflask\tand\trinse\tit\twith\tdistilled\twater.  \u25cf\trinse\tthe\tburette\twith\tdistilled\twater\tand\tthen\twith\tdilute\thydrochloric\tacid\t r.  \u25cf\trepeat\texperiment\t 1\tusing\tdilute\thydrochloric\t acid\tr instead of dilute hydrochloric acid q. experiment 2 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of dilute hydrochloric acid r\tadded\t/\tcm3  experiment 3  \u25cf\tempty\tthe\tconical\tflask\tand\trinse\tit\twith\tdistilled\twater.  \u25cf\trepeat\texperiment\t2\tusing\tthymolphthalein\tindicator\tinstead\tof\tmethyl\torange\tindicator. experiment 3 final\tburette\treading\t /\tcm3 initial\tburette\treading\t /\tcm3 volume of dilute hydrochloric acid r\tadded\t/\tcm3  [6]",
            "3": "3 0620/53/m/j/22 \u00a9 ucles 2022 [turn over  (b)  determine the simplest whole number ratio of the volumes of dilute hydrochloric acid r used  in\texperiment\t2\tand\texperiment\t3.  \t..   [1]  (c)  use your ratio in (b) to deduce the volume of dilute hydrochloric acid q needed when  experiment\t1\tis\trepeated\tusing\tthymolphthalein\tindicator\tinstead\tof\tmethyl\torange\tindicator.  volume of hydrochloric acid q\t=\t\t\t[2]  (d)  compare the concentration of dilute hydrochloric acid q used in experiment 1 to the  concentration of dilute hydrochloric acid r\tused\tin\texperiment\t2. \t\texplain\tyour\tanswer.  \t  \t  \t  \t..   [3]  (e)\t\tstate\thow\tthe\tresults\tchange,\tif\tat\tall,\tif\tthe\taqueous\tsodium\thydroxide\t is\twarmed\tbefore\t adding\tthe\tdilute\thydrochloric\tacid.\tgive\ta\treason\tfor\tyour\tanswer. \t effect\ton\tresults\t\t .  reason \t  [2]  (f)\t\tstate\tthe\tadvantage\t of\tusing\ta\tpipette\tinstead\tof\tthe\tmeasuring\t cylinder\tin\tthese\texperiments.  \t..   [1]  (g)\t\texplain\twhy\ta\twhite\ttile\tis\tused\tin\tthese\texperiments.  \t..   [1]",
            "4": "4 0620/53/m/j/22 \u00a9 ucles 2022  (h)  at the start of experiment 2 the burette was rinsed with distilled water and then with dilute  hydrochloric acid r.  (i)\t\tstate\twhat\twas\tremoved\tfrom\tthe\tburette\twhen\tit\twas\trinsed\twith\tdistilled\twater.  \t ...   [1]  (ii)  state what was removed from the burette when it was rinsed with dilute hydrochloric acid r.  \t ...   [1]  (iii)  explain why the burette does not\tneed\tto\tbe\trinsed\tat\tthe\tstart\tof\texperiment\t3.  \t .  \t ...   [1]  (i)\t\tafter\tthe\tburette\twas\tfilled\twith\tdilute\thydrochloric \tacid\tat\tthe\tstart\tof\texperiment\t 1,\tsome\tof\t the\tacid\twas\trun\tout\tof\tthe\tburette.   one reason for running the acid out of the burette is to make sure the level of the hydrochloric acid  is\ton\tthe\tscale. \t\tgive\tone\tother reason why it is important to run some acid out of the burette after it has been  filled\tfor\tthe\tfirst\ttime\tin\tan\texperiment.\t  \t  \t..   [1]  [total: 20]",
            "5": "5 0620/53/m/j/22 \u00a9 ucles 2022 [turn over 2  you are provided with solid s.   do the following tests on solid s,\trecording\tall\tof\t your\tobservations\tat\teach\tstage.   tests on solid s   to the boiling tube containing solid s add about 20 cm3\tof\tdistilled\twater.\tstopper\tthe\tboiling\ttube\tand\t shake the mixture to dissolve solid s and form solution t.\tdivide\tsolution\t t into six approximately  equal\tportions\tin\tsix\ttest-tubes.  (a)  state the colour change that occurred when distilled water was added to solid s to form  solution t.  from solid s\t..\tto\tsolution\t t \t..   [1]  (b)\t\ttest\tthe\tph\tof\tthe\tfirst\tportion\tof\tsolution\tt. \t ph\t=\t..\t\t[1]  (c)  to the second portion of solution t,\tadd\tthe\tstrip\tof\tmagnesium\tribbon. \t\trecord\tyour\tobservations.  \t  \t..   [2]  (d) (i)  to the third portion of solution t,\tadd\tthe\taqueous\tpotassium\tiodide.   keep the product for use in (ii). \t \trecord\tyour\tobservations.  \t ...   [1]  (ii)  to the product from (i)\tadd\tthe\taqueous \tsodium\tthiosulfate.\tgently\tshake\tthe\ttest-tube. \t \trecord\tyour\tobservations.  \t ...   [1]  (e)  to the fourth portion of solution t,\t add\tabout\t1\tcm\tdepth\tof\tdilute\tnitric\tacid\tfollowed\tby\ta\tfew\t drops\tof\taqueous\tbarium\tnitrate. \t\trecord\tyour\tobservations.  \t..   [1]  (f)\t\tto\tthe\tfifth\tportion\tof\tsolution\t t,\tadd\tabout\t1\tcm\tdepth\tof\tdilute\tnitric\tacid\tfollowed\tby\ta\tfew\t drops\tof\taqueous\tsilver\tnitrate. \t\trecord\tyour\tobservations.  \t..   [1]",
            "6": "6 0620/53/m/j/22 \u00a9 ucles 2022  (g)  to the sixth portion of solution t,\tadd\taqueous\tammonia\tdropwise\tand\tthen\tin\texcess. \t\trecord\tyour\tobservations.  \t  \t  \t..   [3]  (h)  identify solid s.  \t  \t  \t..   [3]  [total: 14]",
            "7": "7 0620/53/m/j/22 \u00a9 ucles 2022 [turn over 3  when solution a and solution b\tare\tmixed\tthey\treact\tslowly\tto\tform\tiodine. \t\tstarch\tsolution\tis\tadded\tto\tthe\tmixture\tto\tact\tas\t an\tindicator.\t \t\twhen\ta\tcertain\tamount\tof\tiodine\tis\tmade\tthere\tis \ta\tsudden\tcolour\tchange\tto\tblue-black. \t\tplan\tan\tinvestigation\t to\tfind\tthe\teffect\tof\ttemperature\t on\tthe\trate\tof\tthe\treaction\tbetween\tsolution\t a  and solution b.   you are provided with solution a,\tsolution\tb,\tstarch\tsolution\tand\tcommon\tlaboratory\tapparatus.  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t ...  \t .   [6]",
            "8": "8 0620/53/m/j/22 \u00a9 ucles 2022blank page",
            "9": "9 0620/53/m/j/22 \u00a9 ucles 2022blank page",
            "10": "10 0620/53/m/j/22 \u00a9 ucles 2022blank page",
            "11": "11 0620/53/m/j/22 \u00a9 ucles 2022notes for use in qualitative analysis tests for anions anion test test result carbonate (co32\u2013) add dilute acid effervescence, carbon dioxide  produced chloride (c l \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratewhite ppt. bromide (br \u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitratecream ppt. iodide ( i\u2013) [in solution]acidify with dilute nitric acid, then add  aqueous silver nitrateyellow ppt. nitrate (no3\u2013) [in solution]add aqueous sodium hydroxide, then  aluminium foil; warm carefullyammonia produced sulfate (so42\u2013) [in solution]acidify, then add aqueous  barium nitratewhite ppt. sulfite (so32\u2013) add dilute hydrochloric acid, warm  gently and test for the presence of sulfur dioxidesulfur dioxide produced  will turn acidified aqueous  potassium manganate( vii) from  purple to colourless tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium (a l 3+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., insoluble in excess ammonium (nh4+)ammonia produced on warming \u2013 calcium (ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. chromium( iii) (cr3+)green ppt., soluble in excess grey-green ppt., insoluble in excess copper( ii) (cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess,  giving a dark blue solution iron(ii) (fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(iii) (fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (zn2+) white ppt., soluble in excess, giving a  colourless solutionwhite ppt., soluble in excess, giving a  colourless solution",
            "12": "12 0620/53/m/j/22 \u00a9 ucles 2022tests for gases flame tests for metal ions gas test and test result metal ion flame colour ammonia (nh3) turns damp red litmus paper blue lithium (li+) red carbon dioxide (co2)turns limewater milky sodium (na+) yellow chlorine (c l 2) bleaches damp litmus paper potassium (k+) lilac hydrogen (h2) \u2018pops\u2019 with a lighted splint copper( ii) (cu2+)blue-green oxygen (o2) relights a glowing splint sulfur dioxide (so2)turns acidified aqueous  potassium manganate( vii) from  purple to colourless permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity . to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge."
        },
        "0620_s22_qp_61.pdf": {
            "1": "*4234628191* chemistry  0620/61 paper 6 alternative to practical may/june 2022  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib22 06_0620_61/3rp \u00a9 ucles 2022 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/61/m/j/22 \u00a9 ucles 2022 1  the apparatus in the diagram was used to show that when a candle is burned both water and  carbon dioxide are formed. the gases produced when the candle burns are passed through the  apparatus using a suction pump. solution zxw liquid wate r icecandleu-tube to suction pump  (a)  name the items of apparatus labelled w and x.  w  ...  x    [2]  (b)  suggest why ice is placed around the u-tube.      ..   [1]  (c)  describe how to test the liquid collected in the u-tube to show it is water.      ..   [1]  (d)  solution z is used to show that carbon dioxide is produced.   identify solution z.   ..   [1]  (e)  both water and carbon dioxide were made.   identify one element that must be in the compound that makes up the candle.   ..   [1]  (f)  describe how the apparatus could be changed to see if sulfur dioxide is made.   give the observations if sulfur dioxide is made.  change  ...  observation    [2]  [total: 8]",
            "3": "3 0620/61/m/j/22 \u00a9 ucles 2022 [turn over 2  a student investigated the rate at which hydrogen gas is made when magnesium reacts with two  different solutions of dilute hydrochloric acid, c and d, with different concentrations. the dilute  hydrochloric acid was in excess in both experiments.   two experiments were done using the apparatus shown. bung conical flask dilute hydrochloric acidclamp trough waterinverted 100  cm3 measuring cylinderrubber delivery tube  experiment 1  \u25cf a measuring cylinder was used to pour 50 cm3 of dilute hydrochloric acid c into a conical flask.  \u25cf the initial temperature of the dilute hydrochloric acid was measured using a thermometer.  \u25cf the apparatus was set up as shown in the diagram.  \u25cf the bung was removed from the conical flask and a coiled 5 cm length of magnesium ribbon  was added to the flask. the bung was replaced immediately and a timer started.  \u25cf the volume of gas collected in the inverted measuring cylinder was recorded every 20 seconds  for 160 seconds.  \u25cf the final temperature of the dilute hydrochloric acid in the flask was measured using a  thermometer.",
            "4": "4 0620/61/m/j/22 \u00a9 ucles 2022  (a)  use the thermometer diagrams and the diagrams of inverted measuring cylinders to complete  the tables. initial final thermometer diagram temperature / \u00b0c thermometer diagram temperature / \u00b0c 30 25 2040 35 3040 30 2020 time  / s volume of gas collected  / cm3diagrams of inverted measuring cylinder 60 50 404070 60 506090 80 7080100 90 80100100 90 80120100 90 80140100 90 80160  [2]  (b) experiment 2  \u25cf experiment 1 was repeated using 50 cm3 of dilute hydrochloric acid d instead of dilute  hydrochloric acid c.   use the thermometer diagrams and the diagrams of inverted measuring cylinders to complete  the tables. initial final thermometer diagram temperature / \u00b0c thermometer diagram temperature / \u00b0c 30 25 2035 30 2530 20 1020 time  / s volume of gas collected  / cm3diagrams of inverted measuring cylinder 30 20 104040 30 206060 50 408060 50 4010070 60 5012080 70 6014070 60 50160  [3]",
            "5": "5 0620/61/m/j/22 \u00a9 ucles 2022 [turn over  (c)  complete a suitable scale on the y-axis and plot your results from experiments 1 and 2 on the  grid.   draw two smooth line graphs. the lines must pass through (0,0). clearly label your lines. volume of gas collected / cm3 0 20 40 60 80 100 120 140 1600  [5]  (d)  from your graph, deduce the volume of gas that was collected after 50 seconds in  experiment 2.   show clearly on the grid  how you worked out your answer.  volume of gas = ...  [3]",
            "6": "6 0620/61/m/j/22 \u00a9 ucles 2022  (e)  explain what can be deduced about the concentrations of dilute hydrochloric acid c and dilute  hydrochloric acid d.            ..   [2]  (f) (i)  state what happens to the temperature of the dilute hydrochloric acid during experiment 1.   ...   [1]  (ii)  state what effect this temperature change has on the total volume of gas made when the  reaction has finished.   ...   [1]  (iii)  describe a change that can be made to the apparatus or reagents to reduce the   temperature change of the acid in experiment 1.   ...   [1]  (g)  suggest why it is important to replace the bung in the conical flask immediately after adding  the magnesium ribbon.      ..   [1]  (h)  state the advantage of measuring the volume of gas collected every 10 seconds rather than  every 20 seconds.   ..   [1]  [total: 20]",
            "7": "7 0620/61/m/j/22 \u00a9 ucles 2022 [turn over 3  solid e and solution f were analysed. solid e was ammonium sulfate.   tests were done on each substance.   tests on solid e   complete the expected observations.   solid e was dissolved in water to form solution e. solution e was divided into three approximately  equal portions in one boiling tube and two test-tubes.  (a)  aqueous sodium hydroxide was added to the first portion of solution e in a boiling tube. the  mixture formed was warmed. any gas produced was tested.  observations  ..     identity of gas    [2]  (b)  to the second portion of solution e, about 1 cm depth of dilute nitric acid followed by a few  drops of aqueous silver nitrate were added.  observations     [1]  (c)  to the third portion of solution e, about 1 cm depth of dilute nitric acid followed by a few drops  of aqueous barium nitrate were added.  observations     [1]",
            "8": "8 0620/61/m/j/22 \u00a9 ucles 2022  tests on solution f tests observations solution f was divided into two equal portions  in two test-tubes. test 1 a strip of universal indicator paper was placed  in the first portion of solution f.the universal indicator paper turned orange test 2 the second portion of solution f was added to  solid sodium carbonate in a boiling tube. any gas made was tested.effervescence and the solid disappeared limewater turned milky  (d)  deduce the ph of solution f.   ..   [1]  (e)  identify the positive ion in solution f.   ..   [1]  [total: 6]",
            "9": "9 0620/61/m/j/22 \u00a9 ucles 2022 [turn over 4  a sample of muddy river water contains water, dissolved solids and insoluble solid mud.   plan an investigation to find the concentration of dissolved solids, in g / dm3, in the river water.   in your answer state how you will work out the concentration of the dissolved solids in g / dm3.   you are provided with a small sample (less than 1 dm3) of muddy river water and common laboratory  apparatus.  (1 dm3 = 1000 cm3)   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "10": "10 0620/61/m/j/22 \u00a9 ucles 2022blank page",
            "11": "11 0620/61/m/j/22 \u00a9 ucles 2022blank page",
            "12": "12 0620/61/m/j/22 \u00a9 ucles 2022blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge."
        },
        "0620_s22_qp_62.pdf": {
            "1": "*9457558127* chemistry  0620/62 paper 6 alternative to practical may/june 2022  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib22 06_0620_62/3rp \u00a9 ucles 2022 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/62/m/j/22 \u00a9 ucles 2022 1  sodium hydrogencarbonate decomposes when heated. the products are solid sodium carbonate,  water and carbon dioxide.   a student decomposed a sample of sodium hydrogencarbonate using the apparatus shown. sodium hydrogencarbonatedelivery tube watera x b  (a)  name the items of apparatus labelled a and b.  a    b   ...  [2]  (b)  when the sodium hydrogencarbonate was heated, a colourless liquid collected at the point  marked x.   suggest the identity of the colourless liquid.   ..   [1]  (c)  on the diagram draw one arrow to show where the apparatus should be heated during the  experiment. [1]  (d)  state an observation that would indicate the sodium hydrogencarbonate had stopped reacting.      ..   [1]  (e)  explain why it is important to remove the delivery tube from the water as soon as heating is  stopped.         ..   [2]  [total: 7]",
            "3": "3 0620/62/m/j/22 \u00a9 ucles 2022 [turn over 2\t\ta\tstudent\tinvestigated \tthe\treaction\t between\t two\tdifferent\t solutions\t of\taqueous\t sodium\tcarbonate,\t solution k and solution l,\tand\tdilute\thydrochloric\tacid\tusing\ttwo\tdifferent\tindicators.   two experiments were done.   experiment 1  \u25cf a burette was rinsed with water and then with the dilute hydrochloric acid.  \u25cf the burette was filled with dilute hydrochloric acid. some of the dilute hydrochloric acid was  run out of the burette so that the level of the dilute hydrochloric acid was on the burette scale.   \u25cf using a measuring cylinder, 25 cm3 of solution k was poured into a conical flask.  \u25cf five drops of methyl orange indicator and five drops of thymolphthalein indicator were added  to the conical flask.  \u25cf the conical flask was placed on a white tile.  \u25cf dilute hydrochloric acid was added slowly from the burette to the conical flask, while the flask  was swirled, until the solution turned yellow. this is the first colour change.  \u25cf more dilute hydrochloric acid from the burette was added to the conical flask, while swirling the  flask, until the solution changed colour again. this is the second colour change.  (a)  use the burette diagrams to complete the table for experiment 1. 1 2 3 initial burette reading11 12 13 burette reading at first colour change22 23 24 burette reading at second colour change experiment 1 burette\treading\tat\tfirst\tcolour\tchange\t /\tcm3 final\tburette\treading\tat\tsecond\tcolour\tchange\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tdilute\thydrochloric\tacid\tadded\tfor\tfirst\t colour\tchange\t /\tcm3 total volume of dilute hydrochloric acid added for  second\tcolour\tchange\t /\tcm3  [3]",
            "4": "4 0620/62/m/j/22 \u00a9 ucles 2022  (b)  experiment 2  \u25cf the conical flask was emptied and rinsed with distilled water.  \u25cf experiment 1 was repeated using solution l instead of solution k.   use the burette diagrams to complete the table for experiment 2. 3 4 5 initial burette reading19 20 21 burette reading at first colour change35 36 37 burette reading at second colour change experiment 2 burette\treading\tat\tfirst\tcolour\tchange\t /\tcm3 final\tburette\treading\tat\tsecond\tcolour\tchange\t /\tcm3 initial\tburette\treading\t /\tcm3 volume\tof\tdilute\thydrochloric\tacid\tadded\tfor\tfirst\t colour\tchange\t /\tcm3 total volume of dilute hydrochloric acid added for  second\tcolour\tchange\t /\tcm3  [3]  (c)  state the colour change observed at the end-point when dilute hydrochloric acid is added to  methyl orange in an alkaline solution.  from  to     [1]  (d)\t\tfor\texperiment\t 1,\tcompare\t the\tvolume\tof\tdilute\thydrochloric\t acid\tneeded\tfor\tthe\tfirst\tcolour\t change with the volume of dilute hydrochloric acid for the second colour change.      ..   [2]",
            "5": "5 0620/62/m/j/22 \u00a9 ucles 2022 [turn over  (e)  compare the concentration of solution k used in experiment 1 to the concentration of solution l  used in experiment 2.   explain your answer.         ..   [3]  (f) (i)  deduce the volume of dilute hydrochloric acid needed for the second colour change when  experiment 2 is repeated using 50 cm3 of solution l.   ...   [2]  (ii)  state why using 50 cm3 of solution l would cause a problem.   .   ...   [1]  (g)  state the advantage of using a pipette instead of the measuring cylinder in these experiments.   ..   [1]  (h)\t\texplain\twhy\tthe\tconical\tflask\twas\tswirled\tas\tthe\tdilute\thydrochloric\t acid\twas\tadded\tfrom\tthe\t burette.      ..   [1]  (i)  at the start of experiment 1, the burette was rinsed with water and then with dilute  hydrochloric acid. \t \tat\tthe\tstart\tof\texperiment\t2,\tthe\tconical\tflask\twas\trinsed\twith\twater\tbut\t not with solution l.  (i)\t\texplain\twhy\tthe\tconical\tflask\twas\trinsed \twith\twater.   .   ...   [1]  (ii)\t\texplain\twhy\tthe\tconical\tflask\twas\t not rinsed with solution l in experiment 2.   .   ...   [1]  [total: 19]",
            "6": "6 0620/62/m/j/22 \u00a9 ucles 2022 3  solid m and solid n were analysed. solid m was iron( iii) nitrate.   tests were done on each substance.  tests on solid m   complete the expected observations.   solid m was dissolved in water to form solution m. solution m was divided into two approximately  equal portions in two test-tubes.  (a)\t\tto\tthe\tfirst\tportion\tof\tsolution\t m, aqueous sodium hydroxide was added gradually until in  excess. the product was kept for (b).  observations  ..   ..   [2]  (b) (i)  the product from (a) was transferred to a boiling tube. a piece of aluminium foil was added  and the mixture warmed gently. any gas produced was tested.  observations  ...   ...   [1]  (ii)  identify the gas made in (i).   ...   [1]  (c)  to the second portion of solution m, about 1 cm depth of dilute nitric acid followed by a few  drops of aqueous barium nitrate were added.  observations     [1]",
            "7": "7 0620/62/m/j/22 \u00a9 ucles 2022 [turn over  tests on solid n tests observations test 1 a\tflame\ttest\twas\tcarried\tout\ton\tsolid\t n. the\tflame\tbecame\tred solid n was dissolved in water to form  solution n. solution n was divided equally into  one test-tube and one boiling tube. test 2 about 1 cm depth of dilute nitric acid followed  by a few drops of aqueous silver nitrate were  added\tto\tthe\tfirst\tportion\tof\tsolution\t n in a  test-tube.no visible change test 3 about 2 cm depth of dilute hydrochloric acid  was added to the second portion of solution n.  the mixture was warmed and any gas  produced was tested.acidified\taqueous\tpotassium\tmanganate( vii) changed from purple to colourless  (d) identify the gas produced in test 3.   ..   [1]  (e)  identify solid n.      ..   [2]  [total: 8]",
            "8": "8 0620/62/m/j/22 \u00a9 ucles 2022 4\t\tthe\tdiagram\tshows\tsome\tcoffee\tbeans. \t\tcaffeine\t occurs\tnaturally\t in\tcoffee\tbeans.\tcaffeine\t is\ta\twhite\tcrystalline\t solid.\tit\tis\tvery\tsoluble\tin\t hot water but much less soluble in cold water. \t\tplan\tan\tinvestigation\tto\tobtain\ta\tpure\tcrystalline\t sample\tof\tcaffeine\tfrom\tcoffee\tbeans. \t\tassume\t that\tall\tother\tsoluble\tsubstances\t in\tcoffee\tbeans\tare\tvery\tsoluble\tin\tboth\thot\tand\tcold\t water. \t\tyou\tare\tprovided\twith\tcoffee\tbeans\tand\tcommon \tlaboratory\tapparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "9": "9 0620/62/m/j/22 \u00a9 ucles 2022blank page",
            "10": "10 0620/62/m/j/22 \u00a9 ucles 2022blank page",
            "11": "11 0620/62/m/j/22 \u00a9 ucles 2022blank page",
            "12": "12 0620/62/m/j/22 \u00a9 ucles 2022blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge."
        },
        "0620_s22_qp_63.pdf": {
            "1": "*3616379926* chemistry  0620/63 paper 6 alternative to practical may/june 2022  1 hour you must answer on the question paper. no additional materials are needed. instructions  \u25cf answer all questions.  \u25cf use a black or dark blue pen. you may use an hb pencil for any diagrams or graphs.  \u25cf write your name, centre number and candidate number in the boxes at the top of the page.  \u25cf write your answer to each question in the space provided.  \u25cf do not use an erasable pen or correction fluid.  \u25cf do not write on any bar codes.  \u25cf you may use a calculator.  \u25cf you should show all your working and use appropriate units. information  \u25cf the total mark for this paper is 40.  \u25cf the number of marks for each question or part question is shown in brackets [  ]. ib22 06_0620_63/3rp \u00a9 ucles 2022 [turn overthis document has 12 pages. any blank pages are indicated.cambridge igcse\u2122",
            "2": "2 0620/63/m/j/22 \u00a9 ucles 2022 1  the apparatus shown was used to determine the percentage of oxygen in a sample of air. copper pieces glass tube air axy b   the glass tube was heated strongly at x while the sample of air was passed backwards and  forwards over the copper pieces in the tube. the source of heat was gradually moved along the  tube from x to y.   during the experiment the copper pieces in the glass tube reacted with oxygen in the sample of air.  (a)  name the item of apparatus labelled b.   ..   [1]  (b)  name the item of laboratory equipment that could be used to heat the glass tube strongly.   ..   [1]  (c)  the copper pieces at y did not change colour when they were heated.   suggest why the copper pieces at y did not change colour.      ..   [1]",
            "3": "3 0620/63/m/j/22 \u00a9 ucles 2022 [turn over  (d) (i)  the table shows the volume of air in each part of the apparatus at the start of the experiment. part of apparatus volume of air at start / cm3 a 0 glass tube 8 b 94   calculate the total volume of air in the apparatus at the start of the experiment.  total volume of air at start = .. cm3  [1]  (ii)  the table shows the volume of gas in each part of the apparatus at the end of the  experiment. part of apparatus volume of gas at end / cm3 a 0 glass tube 8 b 75   calculate the percentage of oxygen in the sample of air.  percentage of oxygen = ..  [1]  [total: 5]",
            "4": "4 0620/63/m/j/22 \u00a9 ucles 2022 2\t\ta\tstudent\tinvestigated\t the\treaction\tbetween\taqueous\tsodium\thydroxide\t and\ttwo\tdifferent\tsolutions\t of\tdilute\thydrochloric\t acid\twith\tdifferent\tconcentrations,\t labelled\t q and r,\t using\ttwo\tdifferent\t indicators.   three experiments were done.  (a) experiment 1  \u25cf a burette was filled with dilute hydrochloric acid q. some of the dilute hydrochloric acid  was run out of the burette so that the level of the dilute hydrochloric acid was on the  burette scale.  \u25cf\tusing\ta\tmeasuring\t cylinder,\t25\tcm3 of aqueous sodium hydroxide was poured into a  conical flask.  \u25cf five drops of methyl orange indicator were added to the conical flask.  \u25cf the conical flask was placed on a white tile.  \u25cf\tdilute\thydrochloric\t acid\twas\tadded\tslowly\tfrom\tthe\tburette\tto\tthe\tconical\tflask,\twhile\tthe\t flask\twas\tswirled,\tuntil\tthe\tsolution\tjust\tchanged\tcolour.  use the burette diagrams to complete the table for experiment 1. 2 3 4 initial reading20 21 22 final reading experiment 1 final\tburette\treading\t /\tcm3 initial burette reading / cm3 volume of dilute hydrochloric acid q added / cm3",
            "5": "5 0620/63/m/j/22 \u00a9 ucles 2022 [turn over  experiment 2  \u25cf the conical flask was emptied and rinsed with distilled water.  \u25cf the burette was rinsed with distilled water and then with dilute hydrochloric acid r.  \u25cf experiment 1 was repeated using dilute hydrochloric acid r instead of dilute  hydrochloric acid q. \t\tuse\tthe\tburette\tdiagrams\tto\tcomplete\tthe\ttable\tfor\texperiment\t2. 8 9 10 initial reading43 44 45 final reading experiment\t2 final\tburette\treading\t /\tcm3 initial burette reading / cm3 volume of dilute hydrochloric acid r added / cm3  experiment 3  \u25cf the conical flask was emptied and rinsed with distilled water.  \u25cf\texperiment\t 2\twas\trepeated\t using\tthymolphthalein\t indicator\tinstead\tof\tmethyl\torange\t indicator.   use the burette diagrams to complete the table for experiment 3. 6 7 8 initial reading42 43 44 final reading experiment 3 final\tburette\treading\t /\tcm3 initial burette reading / cm3 volume of dilute hydrochloric acid r added / cm3  [5]",
            "6": "6 0620/63/m/j/22 \u00a9 ucles 2022  (b)  determine the simplest whole number ratio of the volumes of dilute hydrochloric acid r used  in\texperiment\t2\tand\texperiment\t3.   ..   [1]  (c)  deduce the volume of dilute hydrochloric acid q needed when experiment 1 is repeated using  thymolphthalein indicator instead of methyl orange indicator.  volume of hydrochloric acid q\t=\t..\t\t[2]\t  (d)  compare the concentration of dilute hydrochloric  acid q used in experiment 1 to the  concentration of dilute hydrochloric acid r\tused\tin\texperiment\t2.   explain your answer.            ..   [3]  (e)\t\tstate\thow\tthe\tresults\tchange,\tif\tat\tall,\tif\tthe\taqueous\tsodium\thydroxide\t is\twarmed\tbefore\t adding the dilute hydrochloric acid.   give a reason for your answer. \t effect\ton\tresults\t .  reason   \t [2]  (f)  state the advantage of using a pipette instead of the measuring cylinder in these experiments.   ..   [1]  (g)  explain why a white tile is used in these experiments.   ..   [1]",
            "7": "7 0620/63/m/j/22 \u00a9 ucles 2022 [turn over  (h)\t\tat\tthe\tstart\tof\texperiment\t 2\tthe\tburette\twas\trinsed\twith\tdistilled\twater\tand\tthen\twith\tdilute\t hydrochloric acid r.  (i)  state what was removed from the burette when it was rinsed with distilled water.   ...   [1]  (ii)  state what was removed from the burette when it was rinsed with dilute hydrochloric acid r.   .   ...   [1]  (iii)  explain why the burette does not need to be rinsed at the start of experiment 3.   ...   [1]  (i)\t\tafter\tthe\tburette\twas\tfilled\twith\tdilute\thydrochloric \tacid\tat\tthe\tstart\tof\texperiment\t 1,\tsome\tof\t the acid was run out of the burette.   one reason for running the acid out of the burette is to make sure the level of the hydrochloric acid  is on the scale.   give one other reason why it is important to run some acid out of the burette after it has been  filled\tfor\tthe\tfirst\ttime\tin\tan\texperiment.      ..   [1]  [total: 19]",
            "8": "8 0620/63/m/j/22 \u00a9 ucles 2022 3  solid s and solution y were analysed. solid s was anhydrous copper( ii) sulfate.   tests were done on each substance.   tests on solid s   complete the expected observations.  (a)\t\ta\tflame\ttest\twas\tcarried\tout\ton\tsolid\t s.  observations     [1]   the remaining solid s was dissolved in about 10 cm3 of distilled water to form solution t. solution t  was divided into two approximately equal portions in two test-tubes.  (b)  state the colour change that occurred when water was added to solid s to form solution t.  from solid s .. to solution t  ..   [1]  (c)\t\tto\tthe\tfirst\tportion\tof\tsolution\t t,\tabout\t1\tcm\tdepth\tof\tdilute\tnitric\tacid\tfollowed\tby\ta\tfew\tdrops\t of aqueous barium nitrate were added.  observations     [1]  (d)  to the second portion of solution t,\t aqueous\tammonia\twas\tadded\tdropwise\tand\tthen\tin\texcess.  observations  ..      ..   [3]",
            "9": "9 0620/63/m/j/22 \u00a9 ucles 2022 [turn over  tests on solution y tests observations test 1 a\tflame\ttest\twas\tcarried\tout\ton\tsolution\t y. the\tflame\tbecame\tlilac solution y was divided into three approximately  equal portions in one boiling tube and two  test-tubes. test 2 dilute hydrochloric acid was added to  the portion of solution y in a boiling tube.  the mixture was warmed. a strip of  filter\tpaper\tsoaked\tin\tacidified\taqueous\t potassium manganate( vii) was held at the  mouth of the boiling tube.the\tacidified\taqueous potassium manganate( vii) remained purple test 3 about 1 cm depth of dilute nitric acid followed  by a few drops of aqueous silver nitrate were  added to the second portion of solution y.yellow precipitate test 4 aqueous ammonia was added dropwise and  then in excess to the third portion of solution y.a white precipitate formed which dissolved in excess to give a colourless solution  (e)  name the gas tested for in test 2.   ..   [1]  (f)  identify the three ions in solution y.      ..   [3]  [total: 10]",
            "10": "10 0620/63/m/j/22 \u00a9 ucles 2022 4  when solution a and solution b are mixed they react slowly to form iodine.   starch solution is added to the mixture to act as an indicator.    when a certain amount of iodine is made there is a sudden colour change to blue-black. \t\tplan\tan\tinvestigation\t to\tfind\tthe\teffect\tof\ttemperature\t on\tthe\trate\tof\tthe\treaction\tbetween\tsolution\t a  and solution b.   you are provided with solution a,\tsolution\tb,\tstarch\tsolution\tand\tcommon\tlaboratory\tapparatus.   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   ...   .   [6]",
            "11": "11 0620/63/m/j/22 \u00a9 ucles 2022blank page",
            "12": "12 0620/63/m/j/22 \u00a9 ucles 2022blank page permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. every  reasonable effort has been made by the publisher (ucles) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the  publisher will be pleased to make amends at the earliest possible opportunity. to avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the cambridge   assessment international education copyright acknowledgements booklet. this is produced for each series of examinations and is freely available to download   at www.cambridgeinternational.org after the live examination series. cambridge assessment international education is part of cambridge assessment. cambridge assessment is the brand name of the university of cambridge   local examinations syndicate (ucles), which is a department of the university of cambridge."
        }
    },
    "Other Resources": {},
    "Specimen Papers": {}
}