Cambridge IGCSE Chemistry (BES) 0439 — 2018 May/June Paper 2 · Variant 3

This document consists of 14 printed pages and 2 blank pages. IB18 06_0439_23/FP © UCLES 2018 [Turn over *0906432633* Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY (US) 0439/23 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, Center 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 © UCLES 2018 0439/23/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 solution cotton wool soaked in hydrogen chloride solution long glass tube solid ammonium chloride Which statement explains why the solid ammonium 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 Rf 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 traveled 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 © UCLES 2018 0439/23/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 20 15 10 25 20 15 10 initial temperature of the dilute sulfuric acid (°C) final temperature of the solution (°C) What was the change in temperature in °C? A – 6 B – 4 C 4 D 6 4 The ‘lead’ in a pencil is made of a mixture of graphite and clay. ‘lead’ 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 nonmetal. 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 © UCLES 2018 0439/23/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, CxHy. 10 cm3 of the gaseous hydrocarbon, CxHy, was burned in an excess of oxygen to form 20 cm3 of carbon dioxide and 30 cm3 of water vapor. What is CxHy? A CH4 B C2H4 C C2H6 D C3H8 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 electrolyzed using copper electrodes. Which statement is correct? A Oxygen gas is produced at the positive electrode. B The blue color 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 © UCLES 2018 0439/23/M/J/18 [Turn over 11 Dilute sulfuric acid is electrolyzed 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– → H2 4OH– → 2H2O + O2 + 4e– B 2H+ + 2e– → H2 4OH– + 4H+ → 4H2O C 4OH– → 2H2O + O2 + 4e– 2H+ + 2e– → H2 D 4OH– + 4H+ → 4H2O 2H+ + 2e– → H2 12 Information about two reactions is given. • The neutralization reaction between citric acid and sodium hydrogencarbonate is endothermic. • 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 neutralization 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. CH2=CH2 + H2 → C2H6 The bond energies are shown in the table. The reaction is exothermic. bond bond energy in kJ / mol C–C +350 C=C +610 C–H +410 H–H +436 What is the energy change for the reaction? A –560 kJ / mol B –124 kJ / mol C +486 kJ / mol D +5496 kJ / mol

6 © UCLES 2018 0439/23/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. 2SO2(g) + O2(g) 2SO3(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. 2Fe3+ + Zn → 2Fe2+ + Zn2+ Which statements are correct? 1 Fe3+ is reduced to form Fe2+. 2 Zn oxidizes the Fe3+ ions. 3 Fe3+ is an oxidizing agent. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

7 © UCLES 2018 0439/23/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. NH3(aq) + H2O(l) NH4 +(aq) + OH–(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 © UCLES 2018 0439/23/M/J/18 21 Which element is classified as a nonmetal 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 C D A 23 Which row describes a typical transition element? density in g / cm3 melting point in °C boiling point in °C color of oxide A 0.97 98 883 white B 2.64 769 1382 white C 3.10 –7 59 yellow D 8.96 1085 2562 red 24 Which diagram represents a solid alloy? A B C D

9 © UCLES 2018 0439/23/M/J/18 [Turn over 25 The ionic equations for four reactions are shown. Z + X2+ → Z2+ + X Z + 2W+ → Z2+ + 2W X + 2W+ → X2+ + 2W Y + Z2+ → 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 + 3O2 → 2ZnO + 2SO2 B ZnS + H2O → ZnO + H2S C ZnO + CO → Zn + CO2 D ZnO + H2SO4 → ZnSO4 + H2O 27 Which statement explains why aluminum 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 © UCLES 2018 0439/23/M/J/18 28 Dry air is passed over hot copper until all the oxygen has reacted. heat copper 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 © UCLES 2018 0439/23/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 / °C 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, ZO2. Three uses of ZO2 are listed. ● bleaching agent ● killing bacteria ● manufacturing an important acid What is Z? A carbon B lead C nitrogen D sulfur

12 © UCLES 2018 0439/23/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 neutralization B lime thermal decomposition C slaked lime neutralization 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 CnH2n B CnH2n+1 C CnH2n–1 D CnH2n+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 © UCLES 2018 0439/23/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 nonrenewable resource 39 Which esters have the molecular formula C5H10O2? 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 polymerization B polyamide condensation polymerization C polyester addition polymerization D polyester condensation polymerization

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16 © UCLES 2018 0439/23/M/J/18 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 document consists of 3 printed pages. © UCLES 2018 [Turn over Cambridge Assessment International Education Cambridge International General Certificate of Secondary Education CHEMISTRY (US) 0439/23 Paper 2 Multiple Choice (Extended) May/June 2018 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 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.

0439/23 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 2 of 3 Question Answer Marks 1 C 1 2 D 1 3 A 1 4 C 1 5 B 1 6 B 1 7 D 1 8 C 1 9 C 1 10 C 1 11 C 1 12 B 1 13 B 1 14 C 1 15 D 1 16 C 1 17 C 1 18 D 1 19 B 1 20 C 1 21 B 1 22 A 1 23 D 1 24 B 1 25 C 1 26 A 1 27 A 1 28 B 1

0439/23 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2018 © UCLES 2018 Page 3 of 3 Question Answer Marks 29 C 1 30 C 1 31 D 1 32 A 1 33 D 1 34 B 1 35 A 1 36 D 1 37 C 1 38 A 1 39 A 1 40 B 1