Cambridge IGCSE Chemistry (BES) 0439 — 2018 May/June Paper 4 · Variant 3

READ THESE INSTRUCTIONS FIRST Write your Center 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 (US) 0439/43 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 over IB18 06_0439_43/FP © UCLES 2018 *7050183076*

2 0439/43/M/J/18 © UCLES 2018 1 The following are the symbols and formulae of some elements and compounds. Ar Ca(OH)2 Cl 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 neutralize excess acidity in soil … [1] (f) as a catalyst in the Contact process. … [1] [Total: 6]

3 0439/43/M/J/18 © UCLES 2018 [Turn over 2 (a) 29Al is a radioactive isotope of aluminum. The only non‑radioactive isotope of aluminum 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 13Al 27 3+ ion. number in 13Al 27 3+ nucleons neutrons electrons [3] (b) Aluminum is extracted from its ore by electrolysis. (i) Name the main ore of aluminium. … [1] (ii) Why is aluminum not extracted from its ore by reduction with carbon? … [1] (iii) The main ore of aluminum contains aluminum oxide. Aluminum oxide is dissolved in molten cryolite before it is electrolyzed. Give two reasons, other than cost, why cryolite is used. 1 … 2 …  [2]

4 0439/43/M/J/18 © UCLES 2018 (iv) The reaction at the anode during the extraction of aluminum by electrolysis is shown. 2O2– O2 + 4e– Is this process oxidation or reduction? Give a reason for your answer. … [1] (v) During the extraction of aluminum 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 aluminum 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 aluminum metal and copper(II) sulfate is very slow. … [1] [Total: 15]

5 0439/43/M/J/18 © 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) When a small piece of potassium is added to cold water, the potassium floats and disappears 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 0439/43/M/J/18 © UCLES 2018 (e) When cobalt(II) chloride is added to water an equilibrium is established. [CoCl 4]2– + 6H2O [Co(H2O)6]2+ + 4Cl – blue pink (i) A student adds water to a blue solution containing [CoCl 4]2– 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 [CoCl 4]2–. 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 0439/43/M/J/18 © 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. C H H O C H H H H Complete the dot‑and‑cross diagram to show the electron arrangement in a molecule of ethanol. Show outer shell electrons only. C H H O C H H H H [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, C6H12O6. … [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 0439/43/M/J/18 © UCLES 2018 (d) Ethanol can be oxidized to ethanoic acid. State the chemical reagent needed to oxidize 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, CH3COOH, 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 0439/43/M/J/18 © 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 electrolyzed using the apparatus shown. copper wires power supply platinum electrodes molten nickel(II) iodide 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-equation for the formation of one of these products. products… ionic half-equation …  [3]

10 0439/43/M/J/18 © UCLES 2018 (c) A student electrolyzed copper(II) sulfate solution using the two sets of apparatus shown. apparatus A carbon electrodes copper(II) sulfate solution apparatus B copper electrodes copper(II) sulfate solution power 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 0439/43/M/J/18 © UCLES 2018 [Turn over (iv) Suggest what happens to the color of the solution in apparatus A and apparatus B as the electrolysis progresses. Explain your answer. color of the solution in apparatus A … color of the solution in apparatus B … explanation … … …  [3] [Total: 13]

12 0439/43/M/J/18 © 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 colorless 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 0439/43/M/J/18 © UCLES 2018 [Turn over (c) Chloric(V) acid, HCl O3, is a strong acid. It can be made from calcium chlorate(V). (i) What color is methyl orange indicator in chloric(V) acid? … [1] (ii) Define the term acid 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]

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15 0439/43/M/J/18 © UCLES 2018 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. BLANK PAGE

16 0439/43/M/J/18 © UCLES 2018 Group The Periodic Table of Elements 1 H hydrogen 1 2 He helium 4 I II III IV V VI VII VIII 3 Li lithium 7 4 Be beryllium 9 atomic number atomic symbol Key name relative atomic mass 11 Na sodium 23 12 Mg magnesium 24 19 K potassium 39 20 Ca calcium 40 37 Rb rubidium 85 38 Sr strontium 88 55 Cs cesium 133 56 Ba barium 137 87 Fr francium – 88 Ra radium – 5 B boron 11 13 Al aluminum 27 31 Ga gallium 70 49 In indium 115 81 Tl thallium 204 6 C carbon 12 14 Si silicon 28 32 Ge germanium 73 50 Sn tin 119 82 Pb lead 207 22 Ti titanium 48 40 Zr zirconium 91 72 Hf hafnium 178 104 Rf rutherfordium – 23 V vanadium 51 41 Nb niobium 93 73 Ta tantalum 181 105 Db dubnium – 24 Cr chromium 52 42 Mo molybdenum 96 74 W tungsten 184 106 Sg seaborgium – 25 Mn manganese 55 43 Tc technetium – 75 Re rhenium 186 107 Bh bohrium – 26 Fe iron 56 44 Ru ruthenium 101 76 Os osmium 190 108 Hs hassium – 27 Co cobalt 59 45 Rh rhodium 103 77 Ir iridium 192 109 Mt meitnerium – 28 Ni nickel 59 46 Pd palladium 106 78 Pt platinum 195 110 Ds darmstadtium – 29 Cu copper 64 47 Ag silver 108 79 Au gold 197 111 Rg roentgenium – 30 Zn zinc 65 48 Cd cadmium 112 80 Hg mercury 201 112 Cn copernicium – 114 Fl flerovium – 116 Lv livermorium – 7 N nitrogen 14 15 P phosphorus 31 33 As arsenic 75 51 Sb antimony 122 83 Bi bismuth 209 8 O oxygen 16 16 S sulfur 32 34 Se selenium 79 52 Te tellurium 128 84 Po polonium – 9 F fluorine 19 17 Cl chlorine 35.5 35 Br bromine 80 53 I iodine 127 85 At astatine – 10 Ne neon 20 18 Ar argon 40 36 Kr krypton 84 54 Xe xenon 131 86 Rn radon – 21 Sc scandium 45 39 Y yttrium 89 57–71 lanthanoids 89–103 actinoids 57 La lanthanum 139 89 Ac lanthanoids actinoids The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). actinium – 58 Ce cerium 140 90 Th thorium 232 59 Pr praseodymium 141 91 Pa protactinium 231 60 Nd neodymium 144 92 U uranium 238 61 Pm promethium – 93 Np neptunium – 62 Sm samarium 150 94 Pu plutonium – 63 Eu europium 152 95 Am americium – 64 Gd gadolinium 157 96 Cm curium – 65 Tb terbium 159 97 Bk berkelium – 66 Dy dysprosium 163 98 Cf californium – 67 Ho holmium 165 99 Es einsteinium – 68 Er erbium 167 100 Fm fermium – 69 Tm thulium 169 101 Md mendelevium – 70 Yb ytterbium 173 102 No nobelium – 71 Lu lutetium 175 103 Lr lawrencium –

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 10 printed pages. © UCLES 2018 [Turn over Cambridge Assessment International Education Cambridge International General Certificate of Secondary Education CHEMISTRY (US) 0439/43 Paper 4 Theory (Extended) May/June 2018 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 International will not enter into discussions about these mark schemes. Cambridge International is publishing the mark schemes for the May/June 2018 series for most Cambridge IGCSE™, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components.

0439/43 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 2 of 10 Generic Marking Principles These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these marking principles. GENERIC MARKING PRINCIPLE 1: Marks must be awarded in line with: • the specific content of the mark scheme or the generic level descriptors for the question • the specific skills defined in the mark scheme or in the generic level descriptors for the question • the standard of response required by a candidate as exemplified by the standardisation scripts. GENERIC MARKING PRINCIPLE 2: Marks awarded are always whole marks (not half marks, or other fractions). GENERIC MARKING PRINCIPLE 3: Marks must be awarded positively: • marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate • marks are awarded when candidates clearly demonstrate what they know and can do • marks are not deducted for errors • marks are not deducted for omissions • answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the question as indicated by the mark scheme. The meaning, however, should be unambiguous. GENERIC MARKING PRINCIPLE 4: Rules must be applied consistently e.g. in situations where candidates have not followed instructions or in the application of generic level descriptors.

0439/43 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 3 of 10 GENERIC MARKING PRINCIPLE 5: Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may be limited according to the quality of the candidate responses seen). GENERIC MARKING PRINCIPLE 6: Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or grade descriptors in mind.

0439/43 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 4 of 10 Question Answer Marks 1(a) Cl2 / chlorine 1 1(b) SO2 / sulfur dioxide 1 1(c) Cu / copper 1 1(d) Ar / argon 1 1(e) Ca(OH)2 / calcium hydroxide 1 1(f) V2O5 / vanadium(V) oxide 1 Question Answer Marks 2(a)(i) similarities: number of protons and electrons 1 differences: number of neutrons 1 2(a)(ii) nucleons: 27 1 neutrons: 14 1 electrons: 10 1 2(b)(i) bauxite 1 2(b)(ii) aluminium is more reactive than carbon 1 2(b)(iii) to lower the operating temperature / the mixture has a lower melting point than aluminium oxide 1 to increase the conductivity 1

0439/43 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 5 of 10 Question Answer Marks 2(b)(iv) oxidation (because) (the O2-ion OR ‘oxide ions’) electrons are lost OR (the O2-ion OR ‘oxide ions’) oxidation number increases 1 2(b)(v) electrodes/anodes are made from carbon/graphite 1 oxygen (made) reacts with carbon/anode 1 2(c)(i) zinc is more reactive than copper 1 2(c)(ii) displacement / redox 1 2(c)(iii) (aluminium) has (inert) coating of aluminium oxide 1 Question Answer Marks 3(a) any one from: conduct electricity conduct heat malleable ductile shiny 1 3(b)(i) any one from: melting point hardness strength density 1 3(b)(ii) (cobalt) high(er) / (cobalt) strong(er) 1

0439/43 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 6 of 10 Question Answer Marks 3(c) any two from: potassium melts / potassium forms a ball fizzes / bubbles potassium moves (lilac) flame 2 3(d)(i) test: lighted splint / flame result: (squeaky) pop 2 3(d)(ii) any one from: increase surface area (of cobalt) powder the metal add a catalyst 1 3(d)(iii) (particles) have more energy / (particles) move faster 1 more collisions per second / greater collision rate 1 more of the colliding molecules have sufficient energy (activation energy) to react 1 3(e)(i) becomes pink / becomes purple 1 equilibrium moves right 1 3(e)(ii) (forward reaction is) exothermic 1 3(f) 3+ 1

0439/43 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 7 of 10 Question Answer Marks 4(a) any two from: trend in physical properties same/similar chemical properties (same) general formula successive members differ by CH2 same functional group 2 4(b) all bonding pairs correct and no extra incorrect non-bonding electrons 1 4 non-bonding electrons on O completing oxygen octet 1 4(c)(i) C2H4 + H2O Æ C2H5OH 1 4(c)(ii) C6H12O6 Æ 2CO2 + 2C2H5OH 1 4(c)(iii) any one from: pure(r) product fast(er) reaction continuous process 1 4(c)(iv) any one from: renewable feedstock lower temperature lower pressure 1 4(d) (acidified) potassium manganate(VII) 1

0439/43 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 8 of 10 Question Answer Marks 4(e)(i) ester linkage correct 1 fully correct molecule 1 4(e)(ii) ethyl ethanoate 1 4(e)(iii) ester 1 4(f)(i) partially dissociated / partially ionised 1 4(f)(ii) add excess copper(II) carbonate to ethanoic acid 1 filter 1 heat to point of crystallisation AND leave (to cool) 1 4(f)(iii) ethanoic acid + copper carbonate → copper ethanoate + carbon dioxide + water 1

0439/43 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 9 of 10 Question Answer Marks 5(a) 14.01/59 : 60.33/127 : 2.85/1 : 22.81/16 OR 0.237 : 0.475 : 2.85 : 1.43 1 NiI2H12O6 1 5(b)(i) electrons 1 5(b)(ii) (positive and negative) ions 1 5(b)(iii) nickel 1 iodine 1 Ni2+ + 2e− → Ni OR 2 I− → I2 + 2 e − 1 5(c)(i) copper formed/copper deposited 1 5(c)(ii) oxygen 1 5(c)(iii) copper removed or copper lost or copper forms ions 1 5(c)(iv) any three from: (apparatus A): solution becomes paler/fades in A (apparatus B): solution stays the same colour in B (explanation): copper ions removed (but not added) copper ions not replaced in A OR copper ions both removed and added (at the same rate) copper ions are being replaced (continually) 3

0439/43 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 10 of 10 Question Answer Marks 6(a)(i) 74 1 0.12 1 6(a)(ii) 0.3 1 6(a)(iii) 0.02 1 6(a)(iv) 207 1 4.14 1 6(a)(v) 75% 1 6(b)(i) heat it 1 6(b)(ii) Ca(Cl O3)2 → CaCl 2 + 3O2 1 mark for O2 as product 1 mark for the rest correct and balanced 2 6(c)(i) red 1 6(c)(ii) proton donor 1 6(c)(iii) → Cl O3 − + H3O+ 1