Chemistry 0620/33 May/June 2019: question paper and mark scheme

Question

The diagram shows part of the structures of five substances, A, B, C, D and E. H H C H Na+ Cl – Na+ Cl – Br Br Br H C H H H H Cl – Na+ Cl – Na+ Br Br H H Br H H Na+ Cl – Na+ Cl – Br Br C H C Br Cl – Na+ Cl – Na+ Br H H H A B C Ar Ar Zn Zn Zn Zn Zn Ar Ar Zn Zn Zn Zn Zn Zn Zn Zn Zn Ar Ar D E (a) Answer the following questions about these structures. Each structure may be used once, more than once or not at all. (i) Which two of these structures, A, B, C, D or E, are compounds? …… and . …… [2] (ii) Which one of these structures, A, B, C, D or E, is monatomic? . …… [1] (iii) Which one of these structures, A, B, C, D or E, conducts electricity when solid? . …… [1] (iv) Which one of these structures, A, B, C, D or E, is the main constituent of natural gas? . …… [1] (v) Which one of these structures, A, B, C, D or E, is a solid which is soluble in water? . …… [1] (vi) Which one of these structures, A, B, C, D or E, is a hydrocarbon? . …… [1] (b) Substance E is present in air. Air is a mixture of different gases. Describe two characteristics of a mixture. 1 . …… . …… 2 . …… . …… [2] [Total: 9]

Question

This question is about iron and iron compounds. (a) Iron can be extracted from iron ore by reduction with carbon in a blast furnace. (i) Which one of these substances is an ore of iron? Draw a circle around the correct answer. bauxite graphite hematite limestone [1] (ii) The equation shows one of the reactions occurring in the blast furnace. 2Fe2O3 + 3C 4Fe + 3CO2 How does this equation show that Fe2O3 is reduced? . …… . …… [1] (iii) The carbon dioxide formed can be reduced by carbon. CO2 + C 2CO The energy level diagram for this reaction is shown. 2CO energy CO2 + C progress of reaction Explain how this diagram shows that the reaction is endothermic. . …… . …… [1] (iv) Explain why iron is extracted by reduction with carbon and not by electrolysis. Refer to the position of iron in the reactivity series in your answer. . …… . …… [1] (b) Describe three properties of iron that show that it is a transition element and not a Group I element. 1 . …… 2 . …… 3 . …… [3] (c) Iron reacts with chlorine to form iron(III) chloride, Fe2Cl 6. (i) Balance the chemical equation for this reaction. ……Fe + ……Cl 2 Fe2Cl 6 [2] (ii) At 400 °C Fe2Cl 6 molecules decompose. Fe2Cl 6 2FeCl 3 What is meant by the symbol ? . …… [1] (d) The structure of an ion is shown. CN 4– NC CN Fe NC CN CN Deduce the molecular formula of this ion to show the number of iron, carbon and nitrogen atoms. . …… [1] [Total: 11]

Question

The table shows the percentage by mass of the elements in the oceans and in the biosphere. The biosphere is all living organisms. percentage by mass percentage by mass element in the oceans in the biosphere 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 elements 0.07 total 100.00 100.00 (a) Answer these questions using only the information in the table. (i) Deduce the percentage by mass of other elements present in the biosphere. …… % [1] (ii) Which metallic element is present in the oceans in the greatest percentage by mass? . …… [1] (iii) Give two major differences in the percentage by mass of the elements in the oceans and in the biosphere. 1 . …… . …… 2 . …… . …… [2] (b) Living organisms respire. Water is produced during respiration. (i) Name the other product of respiration. . …… [1] (ii) Describe a chemical test for water. test . …… observations …… [2] [Total: 7]

Question

This question is about chlorine and compounds of chlorine. Use the kinetic particle model to describe the arrangement and type of motion of the molecules (a) in: ● solid chlorine . …… . …… ● chlorine gas. …… . …… [4] (b) The graph shows how the pressure of chlorine gas changes when temperature increases. The volume is kept constant. pressure of chlorine gas temperature Describe how the pressure of the chlorine gas changes with temperature. . …… . …… [1] (c) (i) Complete the word equation to show the halogen and halide compound which react to form the products iodine and sodium chloride. …… …… sodium + iodine + chloride [2] (ii) Explain, in terms of the reactivity of the halogens, why aqueous bromine will not react with aqueous sodium chloride. . …… . …… [1] (d) Chlorine reacts with warm turpentine, C10H16. Balance the chemical equation for this reaction. C10H16 + 8Cl 2 ……C + ……HCl [2] [Total: 10]

Question

The structure of compound S is shown. H O H H C C C C C C O H C O H H (a) (i) Draw a circle around the carboxylic acid functional group in this structure. [1] (ii) How many different types of atom are shown in this structure? . …… [1] (b) The melting point of pure S is 159 °C. The boiling point of pure S is 200 °C. (i) What is the physical state of pure S at 100 °C? Explain your answer. . …… . …… [2] (ii) Which one of these statements about an impure sample of compound S is correct? Tick one box. The melting point of impure S is 159 °C and the boiling point is above 200 °C. The melting point of impure S is below 159 °C and the boiling point is 200 °C. The melting point of impure S is 159 °C and the boiling point is 200 °C. The melting point of impure S is below 159 °C and the boiling point is above 200 °C. [1] (c) Aqueous ethanoic acid has chemical properties which are typical of acids. Describe two chemical properties of aqueous ethanoic acid. 1 . …… . …… 2 . …… . …… [2] (d) Ethanol can be converted into ethene by passing ethanol vapour over a catalyst of aluminium oxide. C2H5OH C2H4 + X (i) Identify compound X. . …… [1] (ii) Explain why a catalyst is used. . …… [1] (iii) Draw the structure of a molecule of ethanol. Show all of the atoms and all of the bonds. [1] (e) Ethene can be polymerised. (i) State the name of the polymer formed from ethene. . …… [1] (ii) Terylene is also a polymer. State one use of Terylene. . …… [1] [Total: 12]

Question

This question is about zinc and compounds of zinc. (a) Describe how you could prepare a pure sample of crystals of hydrated zinc sulfate using dilute sulfuric acid and an excess of zinc. . …… . …… . …… . …… . …… [3] (b) The equation shows the effect of heat on anhydrous zinc sulfate. heat ZnSO4 ZnO + SO3 (i) What type of chemical reaction is this? Tick one box. addition decomposition displacement oxidation [1] (ii) When 12.60 g of anhydrous zinc sulfate is heated, the mass of zinc oxide formed is 6.34 g. Calculate the mass of zinc oxide formed when 63.0 g of anhydrous zinc sulfate is heated. mass of zinc oxide = …… g [1] (c) Complete the table to calculate the relative formula mass of anhydrous zinc sulfate, ZnSO4. Use your Periodic Table to help you. type of atom number of atoms relative atomic mass zinc 1 65 1 × 65 = 65 sulfur oxygen relative formula mass = …… [2] (d) Complete the table to show the number of electrons, protons and neutrons in the sulfur atom and zinc ion shown. number of number of number of electrons neutrons protons 16S 36 30Zn 67 2+ 30 [4] (e) An alloy contains zinc, copper and aluminium. What is meant by the term alloy? . …… . …… [1] [Total: 12]

Question

A student investigates the rate of reaction of large pieces of magnesium carbonate with an excess of dilute nitric acid. MgCO3 + 2HNO3 Mg(NO3)2 + CO2 + H2O (a) Name the salt formed when magnesium carbonate reacts with dilute nitric acid. . …… [1] (b) The graph shows how the volume of carbon dioxide changes with time. 60 50 40 volume of carbon dioxide / cm3 30 20 10 0 0 20 40 60 80 100 120 140 time / s (i) After how many seconds did the reaction finish? …… s [1] (ii) From the graph, deduce the volume of carbon dioxide produced during the first 50 seconds of the experiment. ……cm3 [1] (iii) The experiment is repeated using smaller pieces of the same mass of magnesium carbonate. All other conditions are kept the same. Draw a line on the grid for the experiment using smaller pieces of magnesium carbonate. [2] (iv) How does increasing the temperature affect the rate of this reaction? All other conditions are kept the same. . …… [1] (v) How does decreasing the concentration of nitric acid affect the rate of this reaction? All other conditions are kept the same. . …… [1] (c) Nitric acid contains nitrate ions. Complete these sentences about the test for nitrate ions using words from the list. aluminium ammonia blue chloride copper green iron nitrate oxygen red Aqueous sodium hydroxide and …… foil are added to the solution being tested. The mixture is warmed gently. The …… produced turns damp …… litmus paper …… . [3] [Total: 10]

Question

This question is about Group IV elements and their compounds. (a) Lead compounds are pollutants in the air. (i) State one source of lead compounds in the air. . …… [1] (ii) State one adverse effect of lead compounds on health. . …… [1] (b) The table shows how easy it is to reduce four metal oxides with carbon. metal oxide ease of reduction with carbon bismuth(III) oxide reduced by carbon only above 250 °C chromium(III) oxide reduced by carbon only above 1200 °C lead(II) oxide reduced by carbon only above 440 °C zinc oxide reduced by carbon only above 990 °C Use the information in the table to put the four metals in order of their reactivity. Put the least reactive metal first. least reactive most reactive [2] (c) Part of the structure of graphite is shown. Use the information from the diagram to explain why graphite is used as a lubricant. . …… . …… [1] (d) When carbon burns in a limited supply of air, a poisonous gas is formed. Name this gas. . …… [1] (e) When carbon is completely burned in air, carbon dioxide is formed. Carbon dioxide forms a slightly acidic solution in water. Which one of these pH values is the pH of a slightly acidic solution? Draw a circle around the correct answer. pH 6 pH 7 pH 8 pH 10 [1] (f) Carbon dioxide is a greenhouse gas. (i) Name one other major greenhouse gas. . …… [1] (ii) State one effect that greenhouse gases have on the environment. . …… [1] [Total: 9] The Periodic Table of Elements Group I II III IV V VI VII VIII 1 2 H He hydrogen helium Key 1 4 3 4 atomic number 5 6 7 8 9 10 Li Be atomic symbol B C N O F Ne lithium beryllium name boron carbon nitrogen oxygen fluorine neon 7 9 relative atomic mass 11 12 14 16 19 20 11 12 13 14 15 16 17 18 Na Mg Al Si P S Cl Ar sodium magnesium aluminium silicon phosphorus sulfur chlorine argon 23 24 27 28 31 32 35.5 40 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton 39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 16 rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon 85 88 89 91 93 96 – 101 103 106 108 112 115 119 122 128 127 131 55 56 57–71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 lanthanoids Cs Ba Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn caesium barium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury thallium lead bismuth polonium astatine radon 133 137 178 181 184 186 190 192 195 197 201 204 207 209 – – – 87 88 89–103 104 105 106 107 108 109 110 111 112 114 116 actinoids Fr Ra Rf Db Sg Bh Hs Mt Ds Rg Cn Fl Lv francium radium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium flerovium livermorium – – – – – – – – – – – – – 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 lanthanoids La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium 139 140 141 144 – 150 152 157 159 163 165 167 169 173 175 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 actinoids Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium – 232 231 238 – – – – – – – – – – – The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).