Chemistry 0620/33 May/June 2022: question paper and mark scheme

Question

(a) A list of symbols and formulae is shown. Al 2O3 C2H5OH CO2 Fe2O3 H2 He K+ Li+ N2 Na+ O2– Answer the following questions using these symbols or formulae. Each symbol or formula may be used once, more than once or not at all. State which symbol or formula represents: (i) an element that is monoatomic . …… [1] (ii) an ion that gives a red colour in a flame test . …… [1] (iii) an element that can be used as a fuel . …… [1] (iv) a gas that contributes to climate change . …… [1] (v) an ion that is formed when an atom gains electrons. . …… [1] (b) Complete the table to show the relative charges of a proton, neutron and electron. type of particle relative charge proton neutron 0 electron [2] (c) Choose the two correct statements about nitrogen and hydrogen in a mixture. Tick (✓) two boxes. The nitrogen and hydrogen mixture can be separated by physical means. The nitrogen and hydrogen mixture is liquid at room temperature. The atoms of nitrogen and hydrogen in the mixture are chemically combined. Air is mainly a mixture of nitrogen and hydrogen. The bonding in both nitrogen and hydrogen molecules is covalent. [2] [Total: 9]

Question

The table shows the masses of some ions in a 1000 cm3 sample of toothpaste. mass of ion in 1000 cm3 name of ion formula of ion of toothpaste / g NH4+ 0.2 calcium Ca2+ 0.8 CO32– 0.7 chloride Cl – 0.9 fluoride F– 2.2 magnesium Mg2+ 2.0 phosphate PO43– 24.4 sodium Na+ 34.2 sulfate SO42– 10.1 tin(II) Sn2+ 0.4 zinc Zn2+ 0.1 (a) Answer these questions using only the information in the table. (i) State which negative ion has the highest mass in 1000 cm3 of toothpaste. . …… [1] (ii) Name the compound that contains NH4+ and CO32– ions. . …… [1] (iii) Calculate the mass of fluoride ions in 250 cm3 of toothpaste. mass = …… g [1] (b) Describe the observations when aqueous ammonia is added drop by drop to a solution containing zinc ions until the ammonia is in excess. observations with a few drops of ammonia . …… observations with ammonia in excess . …… [2] (c) Toothpaste also contains compound A. The structure of compound A is shown. H H C H H C O H H C O H H Deduce the formula of compound A to show the number of atoms of carbon, hydrogen and oxygen. . …… [1] (d) Compound A is an alcohol. EthanoI, C2H5OH, is also an alcohol. (i) Complete these sentences about ethanol using words from the list. different formula group identical molecule similar Ethanol is part of the alcohol homologous series. Each member of the alcohol homologous series has the same functional …… . Members of the same homologous series have chemical properties that are …… . [2] (ii) When ethanol undergoes incomplete combustion, a small amount of carbon dioxide is produced. Name two other substances that are produced when ethanol undergoes incomplete combustion. [Total: 10]

Question

This question is about Group I and Group VII elements. (a) Deduce the number of electrons, neutrons and protons in one atom of the isotope of sodium shown. 11Na 23 number of electrons . …… number of neutrons …… number of protons …… [3] (b) Sodium reacts with chlorine to produce sodium chloride. (i) State the colour of chlorine gas. . …… [1] (ii) Chlorine is a diatomic molecule. State the meaning of the term diatomic. . …… [1] (iii) Complete the chemical equation for the reaction of sodium with chlorine. 2Na + …… → ……NaCl[2] (iv) Sodium chloride is an ionic compound. Describe two physical properties of ionic compounds. 1 . …… 2 . …… [2] (c) The table shows some properties of four Group I elements. melting point boiling point atomic radius element / °C / °C / nm lithium 181 1342 0.157 sodium 98 883 potassium 760 0.235 rubidium 39 686 0.250 (i) Complete the table by predicting: ● the melting point of potassium ● the atomic radius of sodium. [2] (ii) Predict the physical state of rubidium at 700 °C. Give a reason for your answer. . …… . …… [2] (iii) Give two physical properties of Group I metals that are different from transition elements and state how they are different. 1 . …… . …… 2 . …… . …… [2] (d) Aqueous chlorine reacts with aqueous sodium iodide. Cl 2 + 2NaI → 2NaCl + I2 Explain how this equation shows that chlorine is more reactive than iodine. . …… . …… [1] [Total: 16]

Question

This question is about acids and carbonates. (a) Describe the colour change when excess acid is added to a solution of methyl orange in alkaline solution. (b) Complete the word equation for the reaction of hydrochloric acid with calcium carbonate. hydrochloric calcium …… …… + + + water acid carbonate [2] (c) Calcium carbonate decomposes when heated. calcium carbonate → calcium oxide + carbon dioxide (i) Calcium carbonate is used in the manufacture of lime (calcium oxide). State one other use of calcium carbonate. . …… [1] (ii) The decomposition of calcium carbonate is endothermic. State the meaning of the term endothermic. . …… [1] (iii) The energy level diagram for the decomposition of calcium carbonate is shown. CaO + CO2 energy CaCO3 progress of reaction Explain how the energy level diagram shows that this reaction is endothermic. . …… . …… [1] (iv) When 0.50 g of calcium carbonate decomposes, 120 cm3 of carbon dioxide gas is produced. Calculate the volume of carbon dioxide gas produced when 0.10 g of calcium carbonate is used. volume of carbon dioxide gas = …… cm3 [1] [Total: 8]

Question

This question is about Group VI elements and their compounds. (a) Name the changes of physical state when: ● oxygen gas is converted to liquid oxygen . …… ● solid sulfur is converted directly to sulfur gas. . …… [2] (b) Use the kinetic particle model to describe the differences between solid sulfur and sulfur gas in terms of: ● the arrangement of the particles . …… . …… ● the motion of the particles. . …… . …… [4] (c) Deduce the electronic structure of sulfur. Use the Periodic Table to help you. . …… [1] (d) Sulfur is used in the manufacture of sulfuric acid. The equation shows one of the reactions. 2SO2 + O2 2SO3 (i) State the meaning of the symbol . . …… [1] (ii) Give one use of sulfur dioxide other than in making sulfuric acid. . …… [1] (e) Acid rain is formed when sulfur dioxide reacts with water vapour in the atmosphere. (i) Choose the pH value which is acidic. Draw a circle around your chosen answer. pH 4 pH 7 pH 10 pH 14[1] (ii) Describe one effect of acid rain on buildings. . …… [1] [Total: 11]

Question

(a) The structures of four organic compounds, B, C, D and E, are shown. B C H O H H H H C C H C C C H H O H H H H D E H H H H H H C C C H C C O H H H H H (i) State which compound, B, C, D or E, dissolves in water to form an acidic solution. . …… [1] (ii) State which compound, B, C, D or E, is a saturated hydrocarbon. . …… [1] (iii) State which compound, B, C, D or E, is an unreactive compound except in terms of burning. . …… [1] (iv) State which compound, B, C, D or E, decolourises aqueous bromine. . …… [1] (b) Ethanol can be manufactured from ethene and one other reactant. Describe the manufacture of ethanol from ethene to include: ● the formula of ethene . …… ● the name of the other reactant . …… ● the conditions needed. . …… . …… [4] (c) Complete the table to show the name and uses of some petroleum fractions. name of fraction use of fraction making chemicals kerosene fuel oil [3] [Total: 11]

Question

This question is about lithium and compounds of lithium. (a) Lithium reacts with nitrogen to produce lithium nitride, Li3N. Complete the chemical equation for this reaction. ……Li + N2 → ……Li3N[2] (b) Molten lithium bromide is electrolysed using carbon electrodes. The apparatus is shown. power supply + – (i) Complete the diagram by labelling: ● the anode ● the electrolyte. [2] (ii) Name the products formed at each electrode. positive electrode . …… negative electrode …… [2] (iii) The carbon electrodes conduct electricity. Give one other property that these electrodes must have. . …… [1] (c) A compound of lithium has the formula C3H5O2Li2. Complete the table to calculate the relative molecular mass of C3H5O2Li2. relative atom number of atoms atomic mass carbon 3 12 3 × 12 = 36 hydrogen 1 oxygen 16 lithium 7 relative molecular mass = …… [2] [Total: 9]

Question

A student investigates the rate of decomposition of aqueous hydrogen peroxide using 0.2 g of a catalyst. 2H2O2 → 2H2O + O2 The rate of reaction is found by measuring the volume of oxygen gas produced as time increases. The results are shown on the graph. 60 50 40 volume of oxygen gas 30 produced / cm3 20 10 0 0 10 20 30 40 50 60 70 time / s (a) Deduce the time taken to collect 35 cm3 of oxygen gas. time = …… s [1] (b) The experiment is repeated using 0.2 g of smaller pieces of the catalyst. All other conditions stay the same. Draw a line on the grid to show how the volume of oxygen gas produced changes as time increases. [2] (c) Describe the effect each of the following has on the rate of decomposition of hydrogen peroxide. All other conditions stay the same. ● The reaction is carried out at a higher temperature. . …… ● The reaction is carried out using a lower concentration of hydrogen peroxide. . …… [2] (d) Hydrogen peroxide reduces sodium chlorate(I), NaCl O, to sodium chloride. H2O2 + NaCl O → NaCl + H2O + O2 Describe how this equation shows that sodium chlorate(I) has been reduced. . …… [1] [Total: 6] 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 20 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.).