Cambridge International Examinations Cambridge International General Certificate of Secondary Education. Published

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1 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/11 Paper 1 Multiple Choice (Core) MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 3 printed pages. UCLES 2017 [Turn over

2 0620/11 Cambridge IGCSE Mark Scheme 1 B 1 2 B 1 3 C 1 4 B 1 5 B 1 6 C 1 7 B 1 8 C 1 9 A 1 10 A 1 11 B 1 12 C 1 13 C 1 14 D 1 15 A 1 16 B 1 17 A 1 18 C 1 19 C 1 20 D 1 21 D 1 22 A 1 23 D 1 24 D 1 25 B 1 26 B 1 27 B 1 28 C 1 UCLES 2017 Page 2 of 3

3 0620/11 Cambridge IGCSE Mark Scheme 29 A 1 30 A 1 31 C 1 32 C 1 33 D 1 34 D 1 35 C 1 36 B 1 37 D 1 38 A 1 39 D 1 40 C 1 UCLES 2017 Page 3 of 3

4 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/12 Paper 1 Multiple Choice (Core) MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 3 printed pages. UCLES 2017 [Turn over

5 0620/12 Cambridge IGCSE Mark Scheme 1 B 1 2 B 1 3 C 1 4 B 1 5 D 1 6 C 1 7 A 1 8 B 1 9 C 1 10 B 1 11 B 1 12 C 1 13 A 1 14 B 1 15 A 1 16 B 1 17 C 1 18 A 1 19 C 1 20 A 1 21 C 1 22 A 1 23 D 1 24 D 1 25 B 1 26 D 1 27 B 1 28 C 1 UCLES 2017 Page 2 of 3

6 0620/12 Cambridge IGCSE Mark Scheme 29 A 1 30 D 1 31 B 1 32 C 1 33 C 1 34 D 1 35 D 1 36 A 1 37 C 1 38 B 1 39 C 1 40 C 1 UCLES 2017 Page 3 of 3

7 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/13 Paper 1 Multiple Choice (Core) MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 3 printed pages. UCLES 2017 [Turn over

8 0620/13 Cambridge IGCSE Mark Scheme 1 B 1 2 D 1 3 D 1 4 B 1 5 D 1 6 D 1 7 C 1 8 C 1 9 C 1 10 A 1 11 D 1 12 C 1 13 B 1 14 C 1 15 A 1 16 B 1 17 B 1 18 D 1 19 C 1 20 C 1 21 C 1 22 A 1 23 D 1 24 D 1 25 B 1 26 C 1 27 B 1 28 C 1 29 A 1 UCLES 2017 Page 2 of 3

9 0620/13 Cambridge IGCSE Mark Scheme 30 B 1 31 B 1 32 C 1 33 C 1 34 D 1 35 B 1 36 B 1 37 A 1 38 C 1 39 D 1 40 C 1 UCLES 2017 Page 3 of 3

10 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/21 Paper 2 Multiple Choice (Extended) MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 3 printed pages. UCLES 2017 [Turn over

11 0620/21 Cambridge IGCSE Mark Scheme 1 D 1 2 C 1 3 D 1 4 B 1 5 C 1 6 D 1 7 B 1 8 A 1 9 B 1 10 B 1 11 B 1 12 C 1 13 B 1 14 C 1 15 A 1 16 C 1 17 D 1 18 A 1 19 C 1 20 D 1 21 D 1 22 A 1 23 C 1 24 D 1 25 A 1 26 B 1 27 C 1 28 C 1 UCLES 2017 Page 2 of 3

12 0620/21 Cambridge IGCSE Mark Scheme 29 A 1 30 D 1 31 D 1 32 C 1 33 C 1 34 D 1 35 C 1 36 C 1 37 C 1 38 C 1 39 B 1 40 C 1 UCLES 2017 Page 3 of 3

13 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/22 Paper 2 Multiple Choice (Extended) MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 3 printed pages. UCLES 2017 [Turn over

14 0620/22 Cambridge IGCSE Mark Scheme 1 D 1 2 C 1 3 A 1 4 A 1 5 B 1 6 B 1 7 B 1 8 A 1 9 B 1 10 B 1 11 B 1 12 C 1 13 B 1 14 A 1 15 A 1 16 A 1 17 D 1 18 B 1 19 B 1 20 A 1 21 A 1 22 A 1 23 B 1 24 D 1 25 D 1 26 B 1 27 C 1 28 C 1 UCLES 2017 Page 2 of 3

15 0620/22 Cambridge IGCSE Mark Scheme 29 A 1 30 C 1 31 A 1 32 D 1 33 C 1 34 C 1 35 D 1 36 A 1 37 C 1 38 D 1 39 B 1 40 D 1 UCLES 2017 Page 3 of 3

16 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/23 Paper 2 Multiple Choice (Extended) MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 3 printed pages. UCLES 2017 [Turn over

17 0620/23 Cambridge IGCSE Mark Scheme 1 D 1 2 D 1 3 B 1 4 C 1 5 C 1 6 C 1 7 C 1 8 A 1 9 B 1 10 B 1 11 D 1 12 C 1 13 D 1 14 B 1 15 A 1 16 C 1 17 D 1 18 A 1 19 D 1 20 D 1 21 C 1 22 A 1 23 D 1 24 D 1 25 A 1 26 B 1 27 D 1 28 C 1 UCLES 2017 Page 2 of 3

18 0620/23 Cambridge IGCSE Mark Scheme 29 A 1 30 C 1 31 B 1 32 B 1 33 C 1 34 C 1 35 B 1 36 B 1 37 C 1 38 D 1 39 B 1 40 B 1 UCLES 2017 Page 3 of 3

19 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/31 Paper 3 Theory (Core) MARK SCHEME Maximum Mark: 80 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 7 printed pages. UCLES 2017 [Turn over

20 0620/31 Cambridge IGCSE Mark Scheme 1(a)(i) A 1 1(a)(ii) E 1 1(a)(iii) C 1 1(a)(iv) B 1 1(a)(v) C 1 1(b) number of electrons in Br = 36 1 number of neutrons in Cl = 18 1 number of protons in Cl = 17 AND number of protons in Br = (a)(i) Na + / sodium 1 2(a)(ii) sulfite / sulfate(iv) 1 2(a)(iii) 3 (mg) 1 2(a)(iv) 36.3 (mg) 1 2(a)(v) calcium hydrogencarbonate 1 2(b) flame test 1 yellow 1 2(c) MgCl 2 1 UCLES 2017 Page 2 of 7

21 0620/31 Cambridge IGCSE Mark Scheme 2(d) negative electrode: calcium / Ca 1 positive electrode: chlorine / Cl 2 1 3(a) any 5 of: X has covalent bonding X particles are randomly arranged / irregularly arranged X particles are moving rapidly / freely / randomly / irregularly Y has ionic bonding / ionic Y particles are regularly arranged / lattice / in rows / uniformly arranged Y particles (only) vibrate / do not move from place to place Z has covalent bonding Z particles are regularly arranged / lattice / in a tetrahedral shape Z particles (only) vibrate / do not move from place to place 5 3(b) volume gets smaller 1 particles get closer together 1 3(c) drill tips / drills / cutting (tools) 1 3(d) A / substance Y dissolves easily in water 1 C / substance Y melts (at 8015 C) 1 the change can be reversed by altering the conditions 1 UCLES 2017 Page 3 of 7

22 0620/31 Cambridge IGCSE Mark Scheme 4(a) has two atoms in a molecule / two atoms combined 1 4(b)(i) the chlorine has displaced / replaced the bromine (in KBr) 1 4(b)(ii) (from green / colourless) to orange 1 4(b)(iii) I 2 1 KBr 1 4(c) add (nitric acid then aqueous) silver nitrate 1 yellow precipitate 1 4(d)(i) water purification / water treatment / killing bacteria / in (swimming) pools / disinfectant 1 4(d)(ii) breaking down of a compound / breaking down of a substance 1 (using) heat 1 4(d)(iii) any 2 distinct pollution problems: litter OR eyesore sticks in gullets OR throats of birds / animals blocking of drains OR watercourses animals gets trapped OR tangled (in plastic) poisonous vapours when burned fills landfill sites 2 UCLES 2017 Page 4 of 7

23 0620/31 Cambridge IGCSE Mark Scheme 5(a) circle drawn around the OH group 1 5(b) (c) C=C double bond 1 5(d)(i) increases with an increasing number of carbon atoms ORA 1 5(d)(ii) any value between 88 and 0 ( C) (exclusive of these values) 1 5(d)(iii) there is no (clear) trend / the numbers go down and up 1 5(d)(iv) liquid 1 30 C is between melting and boiling point / 30 C is above the melting point and below the boiling point 1 5(d)(v) substance containing carbon and hydrogen 1 only / and no other element 1 5(d)(vi) H H 1 H C C H H H 5(d)(vii) 3 (CO 2 ) 1 5 (O 2 ) 1 UCLES 2017 Page 5 of 7

24 0620/31 Cambridge IGCSE Mark Scheme 6(a)(i) aluminium low density 1 good electrical conductivity 1 6(a)(ii) iron is cheap(er) / tungsten is (too) expensive OR iron is strong(er) / tungsten is weaker 1 6(a)(iii) tungsten because it has a (very) high melting point 1 6(b) any 2 properties: high melting point / high boiling point high density hard / strong sonorous / rings (when hit) ions are coloured / compounds are coloured 2 6(c) 2 (W) 1 3 (O 2 ) 1 6(d) tungsten < cobalt < iron < magnesium IF full credit is not awarded, allow 1 mark for either a correct sequence apart from a consecutive pair reversed OR for the whole sequence reversed 2 6(e)(i) the more concentrated the acid, the greater the rate ORA 1 6(e)(ii) nitric (acid) 1 6(e)(iii) any value between 19 and 39 hours (exclusive of these values) 1 6(e)(iv) ph 4 1 UCLES 2017 Page 6 of 7

25 0620/31 Cambridge IGCSE Mark Scheme 7(a) 7(b) 7(c)(i) the energy of the reactants is greater than the energy of the products / the product has less energy than the reactants / the arrow is going down (from reactants to product) any 2 sources: carbon monoxide from incomplete combustion of fossil fuels / named fossil fuel / named carbon-containing fuel carbon dioxide from combustion of fossil fuels / respiration methane from animal flatulence / rice paddy fields / bacteria / decomposition of vegetation / decomposition of animals any 3 effects: carbon dioxide: global warming / greenhouse effect / acidification of oceans methane: global warming / greenhouse effect carbon monoxide: poisonous / toxic making mortar / whitewash / neutralising (acidic) soils / neutralising acidic lakes / flue gas desulfurisation / steelmaking / glassmaking / making plaster (c)(ii) 100 IF full credit is not awarded, allow 1 mark for (Ca =) 40, (C =) 12 and (O =) (d) add hydrochloric acid to the mixture 1 filter off the carbon 1 wash carbon (with water or other solvent) AND dry in an oven / air dry / leave in air / leave to dry 1 UCLES 2017 Page 7 of 7

26 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/32 Paper Theory (Core) MARK SCHEME Maximum Mark: 80 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 8 printed pages. UCLES 2017 [Turn over

27 0620/32 Cambridge IGCSE Mark Scheme 1(a)(i) A 1 1(a)(ii) B 1 1(a)(iii) B 1 1(a)(iv) E 1 1(a)(v) C 1 1(b) number of electrons in O 2 ion = 10 1 number of neutrons in S = 18 1 number of protons in S = 16 AND in O 2 ion = 8 1 UCLES 2017 Page 2 of 8

28 0620/32 Cambridge IGCSE Mark Scheme 2(a)(i) chloride 1 2(a)(ii) sodium / Na + 1 2(a)(iii) 0.4 (mg) 1 2(a)(iv) 34 (mg) 1 2(a)(v) sodium hydrogencarbonate 1 2(b) flame test 1 lilac colour 1 2(c) KNO 3 1 2(d) negative electrode: potassium / K 1 positive electrode: bromine / Br 1 UCLES 2017 Page 3 of 8

29 0620/32 Cambridge IGCSE Mark Scheme 3(a) any 5 of: X has ionic bonding / ionic X particles are regularly arranged / lattice / in rows / uniformly arranged X particles (only) vibrate / do not move from place to place Y has covalent bonding Y has irregular arrangement of particles / random arrangement Y particles are sliding over each other / moving slowly Z has covalent bonding Z particles are randomly arranged / irregularly arranged Z particles moving randomly / moving rapidly / moving freely / moving quickly / moving fast 5 3(b) volume increases / volume gets larger 1 particles get further apart 1 3(c) white 1 to blue 1 3(d) it has (two different types of) atoms bonded / joined 1 UCLES 2017 Page 4 of 8

30 0620/32 Cambridge IGCSE Mark Scheme 4(a)(i) bauxite 1 4(a)(ii) it is (very) reactive / too reactive / above carbon in the reactivity series / more reactive than carbon 1 4(b)(i) hydrogen/ H 2 1 4(b)(ii) gas syringe connected to a flask OR this described in words 1 closed apparatus / workable apparatus OR this described in words 1 timer or stopwatch OR this described in words 1 4(c) for aircraft / car bodies 1 low density 1 4(d) any 2 advantages: saves energy saves mining of ore saves other finite resources saves transport costs of bringing ore to factory reduces pollution(due to dust or exhaust fumes etc.) 2 4(e)(i) (zinc oxide) loses oxygen 1 4(e)(ii) reactant level below product level / reactants have less energy than products / products have more energy than reactants 1 UCLES 2017 Page 5 of 8

31 0620/32 Cambridge IGCSE Mark Scheme 5(a)(i) circle around carboxylic acid group 1 5(a)(ii) alcohol 1 5(b) C 3 H 6 O 3 1 5(c) alcohol group shown as O H 1 rest of the structure correct 1 5(d)(i) how easily it evaporates / boils 1 5(d)(ii) butanol 1 5(d)(iii) any value between 65 and 98 ( C) (exclusive of these values) 1 5(d)(iv) gas / vapour C is above the boiling point 1 5(e)(i) 2 (H 2 O) 1 O 2 1 5(e)(ii) 32 IF full credit is not awarded, allow 1 mark for (C =) 12, (O =) 16 and (H =) 1 2 UCLES 2017 Page 6 of 8

32 0620/32 Cambridge IGCSE Mark Scheme 6(a) M (good) resistance to corrosion 1 high(est) relative strength 1 6(b) Q 1 6(c) any 3 from: high melting point / high boiling point high density forms coloured compounds / compounds are coloured / ions are coloured has more than one oxidation state / forms ions with different charges forms complex ions catalyst hard / strong sonorous / rings (when hit) 3 6(d) 2 (HCl ) 1 H 2 1 6(e) 6(f)(i) gold < copper < iron < potassium IF full credit is not awarded, allow 1 mark for either a correct sequence apart from a consecutive pair reversed OR for the whole sequence reversed the higher the concentration the faster the rate / the lower the concentration the slower the rate / as the concentration increases the rate of reaction increases 2 1 6(f)(ii) phosphoric 1 6(f)(iii) any value between 45 and 102 hours (exclusive of these values) 1 6(f)(iv) ph 2 1 UCLES 2017 Page 7 of 8

33 0620/32 Cambridge IGCSE Mark Scheme 7(a) (substance containing) only one type of atom 1 7(b) underground / volcanoes / crude oil / petroleum 1 suitable use, e.g. (making) sulfuric acid / making SO 2 / dusting plants / vulcanising rubber 1 7(c) sublimation / subliming / sublime 1 7(d) any 2 sources: sulfur dioxide: from volcanoes / burning fossil fuels oxides of nitrogen: from car exhausts / high temperature furnaces / lightning any 3 effects: sulfur dioxide: acid rain / named effects of acid rain sulfur dioxide: irritates eyes or skin oxides of nitrogen: acid rain / named effect of acid rain oxides of nitrogen: breathing difficulties / breathing problems / irritates eyes / skin / photochemical smog 5 7(e) add hydrochloric acid to the mixture 1 filter off the sulfur / sulfur on filter paper 1 wash sulfur (with water or other solvent) AND dry in an oven / air dry / leave to dry (in air) 1 UCLES 2017 Page 8 of 8

34 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/33 Paper 3 Theory (Core) MARK SCHEME Maximum Mark: 80 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 8 printed pages. UCLES 2017 [Turn over

35 0620/33 Cambridge IGCSE Mark Scheme 1(a)(i) E 1 1(a)(ii) C 1 1(a)(iii) C 1 1(a)(iv) D 1 1(a)(v) A 1 1(b) number of electrons in Ca 2+ = 18 1 number of neutrons in Mg = 14 1 number of protons in Mg = 12 AND number of protons in Ca 2+ = 20 1 UCLES 2017 Page 2 of 8

36 0620/33 Cambridge IGCSE Mark Scheme 2(a)(i) 8 (mg) 1 2(a)(ii) hydrogencarbonate / HCO 3 1 2(a)(iii) nitrate 1 2(a)(iv) 12.5 (mg) 1 2(b) (damp) red litmus paper 1 turns blue 1 2(c) CaBr 2 1 2(d)(i) negative electrode: calcium / Ca 1 positive electrode: bromine / Br 2 1 2(d)(ii) platinum / Pt 1 UCLES 2017 Page 3 of 8

37 0620/33 Cambridge IGCSE Mark Scheme 3(a) any 5 of: P has ionic bonding / ionic P particles are regularly arranged / lattice / in rows / uniformly arranged P particles (only) vibrating / not moving from place to place Q has covalent bonding Q has irregular arrangement of particles / random arrangement Q particles moving slowly / moving randomly / sliding over each other R no bonding (between atoms) / weak bonding between atoms / weak attractive forces between atoms R has irregular arrangement of particles / random arrangement R particles moving randomly / moving rapidly / freely moving / randomly (moving) / irregular (movement) 5 3(b) volume increases 1 particles get further apart 1 3(c) C / boils (at 1330 C) 1 D / dissolves (readily in water) 1 the change can be reversed by altering the conditions 1 3(d) pencil (leads) / lubricant 1 layers move OR slide over each other 1 UCLES 2017 Page 4 of 8

38 0620/33 Cambridge IGCSE Mark Scheme 4(a)(i) hematite / any other ore of iron 1 4(a)(ii) from the reaction of carbon dioxide 1 with carbon / coke 1 OR reaction of carbon / coke 1 with insufficient oxygen for compete combustion / idea of oxygen not in excess or not limiting 1 4(a)(iii) 2 (Fe) 1 3 (CO 2 ) 1 4(a)(iv) iron(iii) oxide loses oxygen / iron(iii) oxide loses oxygen 1 4(a)(v) 160 IF full credit is not awarded, allow 1 mark for (Fe =) 56 and (O =16) 2 4(b)(i) hydrogen / H 2 1 4(b)(ii) gas syringe connected to flask OR this described in words 1 closed apparatus / workable apparatus OR this described in words 1 timer / stop-watch OR this described in words 1 4(c) (aqueous) sodium hydroxide / aqueous ammonia 1 green precipitate 1 4(d) any 2 advantages from: saves energy / saves mining of ore / saves other finite resources / saves transport costs of bringing ore to factory / reduces dust pollution / exhaust gas pollution 2 UCLES 2017 Page 5 of 8

39 0620/33 Cambridge IGCSE Mark Scheme 5(a) circle drawn around the COOH group 1 5(b) C 2 H 4 O 3 1 5(c) grind up the (sugar) cane / crush the plant 1 with a solvent 1 filter (off the solution) 1 5(d) addition of oxygen / loss of electrons / increase in oxidation number 1 5(e)(i) decreases with an increasing number of carbon atoms ORA 1 5(e)(ii) any value between 118 and 164 ( C) (exclusive of these values) 1 5(e)(iii) solid 1 10 ( C) is below the melting point / melting point is higher than 10 ( C) 1 UCLES 2017 Page 6 of 8

40 0620/33 Cambridge IGCSE Mark Scheme 6(a)(i) J it is (very) strong / it is the strongest 1 it is cheap 1 6(a)(ii) M because it is the hardest 1 6(a)(iii) K because its density is the lowest 1 6(b)(i) line at a steeper gradient than W 1 ends up at same mass loss 1 6(b)(ii) Y 1 6(b)(iii) 1.05 days 1 6(b)(iv) increasing temperature increases rate 1 increasing concentration increases rate 1 6(c) ph 12 1 UCLES 2017 Page 7 of 8

41 0620/33 Cambridge IGCSE Mark Scheme 7(a) pair of electrons in overlap area between O atom and both H atoms 1 7(b) electrical conductivity 1 melting point / boiling point 1 7(c) iron < magnesium < cerium < lithium IF full credit is not awarded, allow 1 mark for either a correct sequence apart from a consecutive pair reversed OR for the whole sequence reversed 2 7(d)(i) water 1 air / oxygen 1 7(d)(ii) any 2 methods from: greasing / covering with plastic / galvanising / painting / (electro)plating 2 7(e) evaporate to crystallisation point / leave in a warm place until crystals form 1 filter off crystals / pick out crystals AND dry on filter paper / heat in drying oven 1 7(f) 4 (CO 2 ) 1 4(H 2 O) 1 UCLES 2017 Page 8 of 8

42 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/41 Paper 4 Theory Extended MARK SCHEME Maximum Mark: 80 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 7 printed pages. UCLES 2017 [Turn over

43 0620/41 Cambridge IGCSE Mark Scheme 1(a) proton number: the number of protons 1 nucleon number: the total number of protons and neutrons 1 nucleon number: in the nucleus / nuclei (of an atom) 1 1(b) (hydrogen is the only atom to have) no neutrons 1 1(c) number of protons number of neutrons number of electrons 19 F Mg P Sr fluorine protons AND neutrons correct 1 magnesium neutrons AND electrons correct 1 phosphorus protons AND neutrons correct 1 phosphorus electrons correct 1 strontium protons AND neutrons correct 1 strontium electrons correct 1 1(d)(i) MgF 2 1 1(d)(ii) Sr 3 P 2 1 UCLES 2017 Page 2 of 7

44 0620/41 Cambridge IGCSE Mark Scheme 2(a)(i) SO 2 1 2(a)(ii) Na 2 O 1 2(a)(iii) Cr 2 O 3 1 2(a)(iv) SiO 2 1 2(a)(v) Al 2 O 3 / Cr 2 O 3 1 2(a)(vi) CO 1 2(b)(i) an amphoteric oxide will react with acids AND with bases 1 2(b)(ii) a neutral oxide will not react with acids or with bases 1 3(a)(i) no (more) effervescence 1 3(a)(ii) magnesium carbonate 1 3(a)(iii) (a solution in which) no more solute will dissolve 1 at that temperature 1 3(a)(iv) the solubility deceases as the temperature decreases 1 3(b)(i) moles of water = 2.52 / 18 = 0.14 (mol) 1 3(b)(ii) moles of anhydrous magnesium sulfate = 0.02 (mol) 1 3(b)(iii) ratio = 0.02 / 0.02 : 0.14 / 0.02 = 1 : 7 1 UCLES 2017 Page 3 of 7

45 0620/41 Cambridge IGCSE Mark Scheme 3(b)(iv) MgSO 4.7H 2 O 2 M1 MgSO 4 M2 rest of the formula correct 3(c) mix and stir the two solutions 1 filter (to obtain residue) 1 wash (the residue) using water 1 dry the residue between filter papers / in a warm place 1 3(d) Pb 2+ (aq) + SO 4 2 (aq) PbSO 4 (s) M1 correct species M2 correct state symbols 2 4(a)(i) roast in air 1 4(a)(ii) 2ZnS + 3O 2 2ZnO + 2SO 2 2 M1 correct species M2 correct balancing 4(b)(i) coke 1 4(b)(ii) zinc is vaporised / boiled 1 and is condensed 1 UCLES 2017 Page 4 of 7

46 0620/41 Cambridge IGCSE Mark Scheme 4(c)(i) Zn Zn e 2 M1 correct species M2 correct balancing 4(c)(ii) 2H + + 2e H 2 2 M1 correct species M2 correct balancing 4(c)(iii) change: (the intensity would) decrease 1 reason: the difference in reactivity between zinc and iron is less than the difference in reactivity between zinc and copper 1 5(a) (stop-) watch AND syringe 1 5(b) graph starts at X and is a curve with a decreasing gradient 1 graph hits zero rate at 114 ± 6 seconds 1 5(c) M1 moles of carbon dioxide = 180 / = M2 molar mass of barium carbonate = M3 mass of barium carbonate = M1 M2 = 1.48 (g) 1 5(d) curve starts from (0,0) and has a lower gradient than the original curve 1 because lumps have a lower surface area 1 UCLES 2017 Page 5 of 7

47 0620/41 Cambridge IGCSE Mark Scheme 5(e) curve starts from (0,0) and has a steeper gradient than the original curve 1 finishes at the same volume of gas 1 because there are more particles per unit volume / dm 3 / cm 3 1 because there are more collisions per second / unit time OR a greater collision rate 1 5(f) 360 (cm 3 ) 1 6(a) (compound that) contains carbon and hydrogen 1 and no other elements / only 1 6(b) any 3 from: same / similar chemical properties (same) general formula (consecutive members) differ by CH 2 same functional group common (allow similar) methods of preparation physical properties vary in predictable manner / show trends / gradually change / example of a physical property variation 3 6(c) propene 1 structure correctly shown 1 6(d) steam 1 catalyst 1 UCLES 2017 Page 6 of 7

48 0620/41 Cambridge IGCSE Mark Scheme 6(e)(i) butanoic acid 1 1 6(e)(ii) acidified 1 (potassium) manganate(vii) 1 6(e)(iii) oxidation 1 6(f) methanol 1 ethanoic acid 1 catalyst 1 heat 1 CH 3 COOH + CH 3 OH CH 3 COOCH 3 + H 2 O 1 UCLES 2017 Page 7 of 7

49 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/42 Paper 4 Theory (Extended) MARK SCHEME Maximum Mark: 80 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 9 printed pages. UCLES 2017 [Turn over

50 0620/42 Cambridge IGCSE Mark Scheme 1(a)(i) fractional distillation 1 1(a)(ii) chromatography 1 1(a)(iii) fermentation / ferment 1 1(a)(iv) (simple) distillation / distil 1 1(a)(v) filtration / decantation / centrifugation 1 1(b)(i) (substance that) cannot be split up / broken down into (two or more) simpler substances by chemical means OR (substance) made of atoms with the same atomic number / number of protons / proton number 1 1(b)(ii) (two or more) elements joined or combined or bonded (together) 1 1(b)(iii) (particle) containing different numbers of protons and electrons OR atom or group of atoms that has gained or lost an electron / electrons 1 UCLES 2017 Page 2 of 9

51 0620/42 Cambridge IGCSE Mark Scheme 2(a) atoms of the same element / atoms with the same proton number / atoms with the same atomic number 1 different neutron number / different nucleon number / different mass number 1 2(b) carbon silicon proton number 6 14 M1 electronic structure 2,4 2,8,4 M2 nucleon number number of neutrons in one atom 6 14 M3 3 2(c)(i) covalent 1 2(c)(ii) award 1 mark for each correct property and one mark for each correct matching reason. 4 property: high melting point / high boiling point reason: bonds between atoms are strong OR covalent bonds are strong / bonds need large amount of energy to break property: non-conductor / poor conductor(of electricity) / insulator reason: no moving charged particles / no moving ions / no moving electrons / all (outer shell) electrons used in bonding property: hard reason: bonds between atoms are strong OR covalent bonds are strong property: brittle reason: bonds between atoms are strong OR covalent bonds are strong / bonds are directional property: insoluble reason: does not form hydrogen bonds with water / no ions that can be hydrated 2(d)(i) incomplete combustion / incomplete burning / combustion in insufficient air / oxygen 1 of fossil fuels / named fossil fuel / named petroleum fraction / name or formula of a type of substance containing carbon 1 2(d)(ii) toxic / poisonous / combines with or binds to haemoglobin 1 UCLES 2017 Page 3 of 9

52 0620/42 Cambridge IGCSE Mark Scheme 2(e)(i) carbon dioxide: (simple) molecular / simple covalent 1 silicon(iv) dioxide: macromolecular / giant molecular / giant covalent / giant atomic 1 2(e)(ii) 2(f) carbon dioxide: weak (force of) attraction between molecules / weak intermolecular forces / weak van der Waals forces / weak dispersion forces / weak London forces silicon(iv) dioxide: covalent bonds are strong / force of attraction between atoms is strong / no weak bonds (are present) / all bonds are strong (weak) forces of attraction in carbon dioxide need small amounts of energy or heat to break / less energy or heat needed to break forces of attraction in carbon dioxide OR (strong) bonds in silicon(iv) dioxide need large amounts of energy or heat to break / more energy or heat needed to break bonds in silicon(iv) dioxide 2NaOH + SiO 2 Na 2 SiO 3 + H 2 O IF full credit is not awarded, allow 1 mark for Na 2 SiO 3 OR 2OH + SiO 2 SiO H 2 O M1 species correct M2 balancing UCLES 2017 Page 4 of 9

53 0620/42 Cambridge IGCSE Mark Scheme 3(a)(i) 450 C atmospheres 1 3(a)(ii) iron 1 3(b)(i) 4(NO) 1 5(O 2 ) AND 6(H 2 O) 1 3(b)(ii) lower yield of NO / lower yield of nitric acid / lower yield of product / equilibrium shifts to left (at higher temperatures) / backward reaction favoured(at higher temperatures) ORA 1 3(b)(iii) too slow / rate decreases ORA 1 3(c) 4NO + 3O 2 + 2H 2 O 4HNO 3 M1 all formulae correct M2 balancing 2 3(d) add copper(ii) carbonate (to acid) until it stops dissolving or no more effervescence / bubbling / fizzing 1 filter (to remove copper(ii) carbonate) 1 evaporate / heat / warm / boil / leave in sun AND until most of the water has gone / some water is left / evaporate some of the water / until it is concentrated / saturation (point) / crystallisation point / crystals form on glass rod or microscope slide / crystals start to form (for any solution) leave / allow to cool / allow to crystallise OR (for any crystals) filter / wash / dry with filter paper / dry in warm place / dry in a (low) oven / leave to dry 1 1 formula of Cu(NO 3 ) 2 1 equation: CuCO 3 + 2HNO 3 Cu(NO 3 ) 2 + CO 2 + H 2 O 1 UCLES 2017 Page 5 of 9

54 0620/42 Cambridge IGCSE Mark Scheme 4(a) any 3 from: catalyst more than one / variable oxidation state / oxidation number / valency form coloured compounds / coloured ions forms complex ions / complexes 3 4(b) add sodium hydroxide (solution) / NaOH / potassium hydroxide (solution) / KOH 1 zinc oxide dissolves / reacts OR copper(ii) oxide does not dissolve / react 1 filter / decant / centrifuge (copper(ii) oxide) 1 4(c)(i) Zn Zn e / 2e M1 formula of Zn 2+ on the right-hand side M2 equation fully correct 2 4(c)(ii) zinc / Zn nickel / Ni copper / Cu 1 4(c)(iii) copper (+) and nickel ( ) V 1 UCLES 2017 Page 6 of 9

55 0620/42 Cambridge IGCSE Mark Scheme 5(a)(i) aqueous potassium chloride aqueous potassium bromide aqueous potassium iodide chlorine bromine iodine 3 5 cells completed correctly = [3] 3 or 4 cells completed correctly = [2] 2 cells completed correctly = [1] 5(a)(ii) Cl 2 + 2KBr 2KCl + Br 2 OR Cl 2 + 2Br 2Cl + Br 2 1 5(b)(i) white 1 5(b)(ii) 0.02 (mol) 1 5(b)(iii) 0.02 (mol) 1 5(b)(iv) 1:2 1 VCl 2 1 UCLES 2017 Page 7 of 9

56 0620/42 Cambridge IGCSE Mark Scheme 5(c)(i) solid 1 5(c)(ii) 2Na + At 2 2NaAt M1 formula of NaAt M2 equation fully correct 2 5(d)(i) 393 (kj) 1 5(d)(ii) 416 (kj) 1 5(d)(iii) 23 (kj / mol) 1 6(a)(i) alkene 1 carboxylic acid 1 6(a)(ii) any 2 from: same / similar chemical properties (same) general formula (consecutive members) differ by CH 2 same functional group common (allow similar) methods of preparation physical properties vary in predictable manner / show trends / gradually change / example of a physical property variation 2 6(b) carboxylic acid / aldehyde 1 ester 1 6(c)(i) colourless / decolourised 1 bubbles / fizzing / effervescence 1 UCLES 2017 Page 8 of 9

57 0620/42 Cambridge IGCSE Mark Scheme 6(c)(ii) addition 1 1 repeat unit continuation bonds at both ends 1 UCLES 2017 Page 9 of 9

58 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/43 Paper 4 Theory (Extended) MARK SCHEME Maximum Mark: 80 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 8 printed pages. UCLES 2017 [Turn over

59 0620/43 Cambridge IGCSE Mark Scheme 1(a)(i) J 1 1(a)(ii) E 1 1(a)(iii) D 1 1(a)(iv) J 1 1(a)(v) L 1 1(a)(vi) D 1 1(b)(i) (atoms with) same number of protons / atomic number / of same element 1 different number of neutrons / different mass number / different nucleon number 1 1(b)(ii) E AND G 1 1(b)(iii) they have the same number of electrons in their outer shell 1 UCLES 2017 Page 2 of 8

60 0620/43 Cambridge IGCSE Mark Scheme 2(a)(i) CH 2 1 2(a)(ii) initial colour: orange 1 final colour: colourless / none 1 2(b)(i) approximately horizontal line draw to right of and below the reagent line 1 energy change shown starting level with the reactant energy AND finishing level with the product energy AND having only one (correct) arrow head AND labelled H / energy change 1 2(b)(ii) (energy required to break bonds =) (energy given out when bonds made =) (kj / mol) 1 2(c) (attractive) forces between molecules 1 (forces of attraction) are stronger in iodine 1 UCLES 2017 Page 3 of 8

61 0620/43 Cambridge IGCSE Mark Scheme 3(a) regular arrangement / lattice of positive ions / magnesium ions / Mg 2+ ions 1 sea of electrons OR delocalised electrons 1 attraction between (positive) ions and (delocalised / sea of) electrons 1 3(b) electrons 1 move / flow (throughout / through the structure) 1 3(c) layers (of atoms or ions) 1 layers / atoms / ions can slide / slip / glide (over each other) (without breaking the metallic bonds) 1 3(d)(i) magnesium shown as (2, 8) using crosses 1 sulfide shown as (2, 8, 8), with the two gained electrons in the outer shell of sulfur shown as crosses and all other electrons on sulfur shown as dots 1 magnesium ion charge as 2 + AND sulfide charge as 2 1 3(d)(ii) melt / fused 1 ions can move OR are mobile 1 UCLES 2017 Page 4 of 8

62 0620/43 Cambridge IGCSE Mark Scheme 4(a) petroleum 1 4(b)(i) saturated: only single bonds OR no double / multiple bonds (between carbon atoms) 1 hydrocarbon: (compound that) contains carbon and hydrogen 1 hydrocarbon: and no other elements / only 1 4(b)(ii) alkane(s) 1 4(b)(iii) any 2 from: same / similar chemical properties (same) general formula (consecutive members) differ by CH 2 same functional group common (allow similar) methods of preparation physical properties vary in predictable manner / show trends / gradually change / example of a physical property variation 2 4(b)(iv) CO 2 and H 2 O on right-hand side and no other products / reagents 1 11 (O 2 ), 7 (CO 2 ), 8 (H 2 O) 1 4(c)(i) acid rain 1 UCLES 2017 Page 5 of 8

63 0620/43 Cambridge IGCSE Mark Scheme 4(c)(ii) carbon monoxide: from incomplete combustion (of fuel) 1 oxides of nitrogen: nitrogen (from the air) reacts with oxygen (from the air) 1 oxides of nitrogen: at high temperatures (in engine) OR (electrical) spark (in the engine) 1 4(c)(iii) poisonous / toxic / death 1 4(c)(iv) any 3 from: oxides of nitrogen are reduced / lose oxygen (to form nitrogen) oxides of nitrogen form nitrogen (oxides of nitrogen) react with carbon monoxide gases (adsorb / stick) on the catalyst s surface 3 4(d)(i) butane 1 4(d)(ii) (molecules with) the same molecular formula 1 different structural formula / different displayed formula 1 4(d)(iii) UV light / sunlight 1 H Cl 1 any mono to deca chloro-substituted derivative of methyl propane 1 UCLES 2017 Page 6 of 8

64 0620/43 Cambridge IGCSE Mark Scheme 5(a)(i) loss (of electrons) 1 5(a)(ii) Ni Ni e 1 5(a)(iii) goes down / gets less / decreases / lower / smaller 1 5(b)(i) beryllium 1 most negative voltage with any (named) metal OR biggest voltage with cobalt / nickel 1 5(b)(ii) cobalt AND nickel 1 5(b)(iii) sign (c) (set up cell) using magnesium and beryllium (electrodes) 1 voltage positive if magnesium is metal 2 1 OR (set up cells) using both magnesium and beryllium with the same metal as the other electrode 1 larger (magnitude) voltages with magnesium 1 OR use magnesium with a different metal and compare to a reference value in a table 1 value is more negative than with beryllium, if magnesium is metal 1 1 UCLES 2017 Page 7 of 8

65 0620/43 Cambridge IGCSE Mark Scheme 6(a)(i) BaCO 3 BaO + CO 2 1 6(a)(ii) anything ph in the range ph 10 to ph (a)(iii) nitrogen dioxide 1 oxygen 1 6(b)(i) Na 2 CO 3 + Ba(NO 3 ) 2 BaCO 3 + 2NaNO 3 M1 formula of NaNO 3 M2 equation fully correct 2 6(b)(ii) filter 1 wash (the residue) using water 1 dry the residue between filter papers / in a warm place 1 6(c)(i) M r = (9.85 / 197 =) 0.05 (mol) 1 6(c)(ii) 0.05 (mol) 1 6(c)(iii) ( ) = 1.2 (dm 3 ) 1 6(c)(iv) moles of HCl at the start = (250 / ) = moles HCl in excess = 0.25 (2 0.05) = 0.15 (mol) 1 UCLES 2017 Page 8 of 8

66 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/51 Paper 5 Practical Test MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 4 printed pages. UCLES 2017 [Turn over

67 0620/51 Cambridge IGCSE Mark Scheme 1(b) initial and final readings completed correctly 1 differences completed correctly 1 all readings to 1 d.p. 1 results comparable to the Supervisor s results 1 1(c) red / brown / amber / orange 1 1(d) (becomes) yellow / orange / paler 1 1(e) yellow to blue / black 1 1(f)(i) solution C is more concentrated 1 a greater volume of thiosulfate was needed 1 1(f)(ii) ratio of the candidate s differences from the table in (b) 1 1(g) 1.5 value from table in (b) for Experiment 2 1 unit: cm 3 1 1(h)(i) 1(h)(ii) 2 sources of error, e.g.: using a measuring cylinder to measure solution C / solution D only carrying out the experiments once going past the end-point 2 meaningful improvements related to (h)(i): use a pipette / burette repeat the experiment improvement linked to going past the end-point 2 2 UCLES 2017 Page 2 of 4

68 0620/51 Cambridge IGCSE Mark Scheme 2(a) green 1 2(b) 2(c)(i) any 2 from: turns black condensation / drops of liquid formed moves / jumps around any 3 from: blue (solution) bubbles / fizz limewater milky 2 3 2(c)(ii) blue 1 precipitate 1 (with excess) deep / royal blue solution / clear / precipitate dissolves 1 2(d) blue-green 1 UCLES 2017 Page 3 of 4

69 0620/51 Cambridge IGCSE Mark Scheme 2(e) copper / Cu 2+ 1 carbonate / CO (f) white 1 2(g)(i) no reaction / no change 1 2(g)(ii) yellow precipitate 1 2(h) lilac 1 2(i) potassium / K + 1 iodide / I 1 3(a) (red) litmus turns blue 1 3(b)(i) heat / boil the mixture 1 condense the vapour 1 3(b)(ii) filter / decant 1 wash residue (with water) 1 dry 1 UCLES 2017 Page 4 of 4

70 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/52 Paper 5 Practical Test MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 5 printed pages. UCLES 2017 [Turn over

71 0620/52 Cambridge IGCSE Mark Scheme 1(a) initial volume, final volume and difference completed correctly 1 difference comparable to the Supervisor s result 1 1(b) initial volume, final volume and difference completed correctly 1 all readings in both tables in (a) and (b) to 1 d.p. 1 1(c)(i) pink / purple / violet to colourless / pale green 1 1(c)(ii) there is a colour change at the end-point already 1 1(d)(i) solution C 1 a greater volume of potassium manganate(vii) / solution A was needed 1 1(d)(ii) ratio of the candidate s differences from the tables in (a) and (b) 1 1(e)(i) 2 value from the table in (b) 1 double the volume of solution C was used / double the volume of solution A was needed 1 1(e)(ii) problem: volume of potassium manganate(vii) solution added would be greater than 50 cm 3 1 solution: use more than one burette / refill burette 1 1(f) advantage: easy (to use) / quick 1 disadvantage: not accurate 1 UCLES 2017 Page 2 of 5

72 0620/52 Cambridge IGCSE Mark Scheme 2(a) yellow 1 2(b) initial and final temperatures recorded 1 temperature difference correctly calculated 1 2(c) any 3 from: (pale) yellow precipitate potassium manganate(vii) turns colourless 3 2(d) no reaction / no change 1 2(e)(i) any 2 from: brown turns blue-black white precipitate 2 2(e)(ii) blue-black colour disappears / turns colourless 1 white 1 2(f) sodium / Na + 1 sulfite / SO (g) red 1 2(h) white 1 precipitate 1 2(i) no reaction / no change 1 UCLES 2017 Page 3 of 5

73 0620/52 Cambridge IGCSE Mark Scheme 2(j) lithium / Li + 1 chloride / Cl 1 UCLES 2017 Page 4 of 5

74 0620/52 Cambridge IGCSE Mark Scheme 3 6 the filtration method any 6 from: weigh mixture (of calcium carbonate and kaolinite) add (dilute) hydrochloric acid in excess / continue adding until there is no more fizzing / add until no more gas is evolved filter wash residue / kaolinite dry weigh residue / kaolinite (change in mass / initial mass) 100 (%) the gas collection / loss of mass method any 6 from: weigh mixture (of calcium carbonate and kaolinite) add (dilute) hydrochloric acid in excess / continue adding until there is no more fizzing / add until no more gas is evolved collect gas in a syringe / measure final total mass measure volume of gas / mass loss calculate moles of CaCO 3 / CO 2 calculate mass of CaCO 3 (mass of CaCO 3 / initial mass) 100 (%) the calcium chloride method any 4 from: weigh mixture (of calcium carbonate and kaolinite) add (dilute) hydrochloric acid in excess / continue adding until there is no more fizzing / add until no more gas is evolved filter UCLES 2017 Page 5 of 5

75 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 0620/53 Paper 5 Practical Test MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components. IGCSE is a registered trademark. This syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate. This document consists of 4 printed pages. UCLES 2017 [Turn over