Chemistry 0620/32 May/June 2022: question paper and mark scheme

Question

(a) A list of symbols and formulae is shown. Br – CH4 CO2 Cu2+ H2 K+ Na+ N2 O2 U 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) a compound that is a product of respiration . …… [1] (ii) an ion that gives a lilac colour in a flame test . …… [1] (iii) a gas which is 21% of clean, dry air . …… [1] (iv) an element that has a radioactive isotope used as a source of energy . …… [1] (v) an ion formed when an atom gains an electron. . …… [1] (b) Complete the table to show the relative masses of a proton, a neutron and an electron. type of particle relative mass proton 1 neutron electron [2] (c) Choose the two correct statements about carbon dioxide. Tick (✓) two boxes. Carbon dioxide is a mixture of two elements. Carbon dioxide is an acidic oxide. Carbon dioxide has ionic bonding. Carbon dioxide has a giant covalent structure. There are three atoms in a molecule of carbon dioxide. [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 ammonium NH4+ 0.5 calcium Ca2+ 3.6 carbonate CO32– 2.5 chloride Cl – 0.9 fluoride F– 1.2 Mg2+ 0.2 phosphate PO43– 28.0 sodium Na+ 32.0 SO42– 10.4 tin(II) Sn2+ 0.3 (a) Answer these questions using only the information in the table. (i) State which positive ion has the lowest mass in 1000 cm3 of toothpaste. . …… [1] (ii) Name the compound that contains Mg2+ and SO42– ions. . …… [1] (iii) Calculate the mass of sodium ions in 200 cm3 of toothpaste. mass = …… g [1] (b) Describe a test for chloride ions. test . …… observations …… [2] (c) Toothpaste also contains glycerol. The structure of glycerol is shown. H H C O H H C O H H C O H H Deduce the formula of glycerol to show the number of atoms of carbon, hydrogen and oxygen. . …… [1] (d) Glycerol is an alcohol. Ethanol is also an alcohol. (i) Draw the structure of ethanol to show all of the atoms and all of the bonds. [1] (ii) Name the two products formed when ethanol undergoes complete combustion. (iii) Give one use of ethanol. . …… [1] [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 potassium shown. 19K 40 number of electrons . …… number of neutrons …… number of protons …… [3] (b) Complete the chemical equation for the reaction of potassium with water to form potassium hydroxide and a gas which pops with a lighted splint. 2K + ……H2O → 2KOH + …… [2] (c) The table shows some properties of four Group I elements. melting point boiling point element relative hardness / °C / °C lithium 181 1342 5.0 sodium 883 …… 0.7 potassium 63 760 rubidium 39 686 0.2 (i) Complete the table by predicting: ● the melting point of sodium ● the relative hardness of potassium. [2] (ii) Predict the physical state of potassium at 100 °C. Give a reason for your answer. . …… . …… [2] (d) Aqueous bromine reacts with aqueous potassium iodide. Br2 + 2KI → 2KBr + I2 (i) Explain how this equation shows that bromine is more reactive than iodine. . …… . …… [1] (ii) State the colour of aqueous iodine. . …… [1] (e) Bromine is a diatomic molecule. State the meaning of the term diatomic. . …… [1] (f) Bromine liquid turns into a gas very easily at room temperature. Choose the word which best describes a substance that evaporates easily. Draw a circle around your chosen answer. conductor flammable malleable volatile[1] [Total: 13]

Question

This question is about acids and bases. (a) Name the type of chemical reaction which occurs when an acid reacts with a base. . …… [1] (b) Describe the colour of litmus in acidic and alkaline solutions. in acidic solution …… in alkaline solution …… [2] (c) Complete the word equation for the reaction of nitric acid with calcium hydroxide. nitric calcium …… …… + + acid hydroxide [2] (d) When nitric acid reacts with calcium hydroxide, the temperature of the reaction mixture increases. (i) Choose the word which best describes this reaction. Draw a circle around your chosen answer. decomposition endothermic exothermic oxidation[1] (ii) Complete the energy level diagram for the reaction of nitric acid with calcium hydroxide by writing the words: ● reactants ● products. energy progress of reaction [1] (e) Calcium hydroxide is slaked lime. Give one use of slaked lime. . …… [1] [Total: 8]

Question

This question is about aluminium. (a) The changes of state of aluminium are shown. A solid liquid aluminium aluminium aluminium gas B Name the changes of state represented by A and B. A …… B …… [2] (b) Use the kinetic particle model to describe the differences between solid aluminium and liquid aluminium in terms of: ● the arrangement of the particles . …… . …… . …… ● the separation of the particles. …… . …… . …… [4] (c) Aluminium ore contains aluminium oxide. (i) Name the main ore of aluminium. . …… [1] (ii) Aluminium is extracted from aluminium oxide by electrolysis. Explain why aluminium is extracted by electrolysis and not by reduction with carbon. . …… . …… [1] (d) Aluminium can be used to reduce iron(III) oxide to iron. Fe2O3 + 2Al → 2Fe + Al 2O3 Describe how this equation shows that iron(III) oxide is reduced. . …… [1] (e) Aluminium is used for electric cables. State one other use of aluminium. Give a reason for this use in terms of the properties of aluminium. use of aluminium …… reason for this use …… . …… [2] (f) Deduce the electronic structure of aluminium. Use the Periodic Table to help you. . …… [1] [Total: 12]

Question

(a) The structures of four organic compounds, C, D, E and F, are shown. C D H H O H H H H H H C C C H C C C C C H H H O H H H H H H E F H H H H H H C C C H C C H H H H H (i) State which two of the compounds, C, D, E and F, are in the same homologous series. (ii) State which compound, C, D, E or F, is the monomer used to make poly(ethene). . …… [1] (iii) State which compound, C, D, E or F, is a carboxylic acid. . …… [1] (b) Petroleum is a mixture of hydrocarbons, which can be separated into fractions. Describe how petroleum is separated into fractions to include: ● the name of the process used to separate the fractions . …… ● how this process separates the different fractions. . …… . …… . …… . …… . …… [4] (c) Complete the table to show the name and uses of some petroleum fractions. name of fraction use of fraction naphtha diesel oil (gas oil) making roads [3] [Total: 10]

Question

This question is about sodium and compounds of sodium. (a) Sodium is a metal in Group I of the Periodic Table. (i) Give two physical properties of all metals. 1 . …… 2 . …… [2] (ii) Give one physical property of Group I metals that is different from most other metals and state how it is different. . …… . …… [1] (b) Sodium reacts with oxygen to form sodium oxide, Na2O. Complete the chemical equation for this reaction. ……Na + O2 → ……Na2O[2] (c) The diagram shows the apparatus used to electrolyse molten sodium iodide. power supply – + (i) Complete the diagram by labelling: ● the electrolyte ● the cathode. [2] (ii) Name the products formed at each electrode. positive electrode . …… negative electrode …… [2] (d) A compound of sodium has the formula Na2S2O3. Complete the table to calculate the relative molecular mass of Na2S2O3. relative atom number of atoms atomic mass sodium 2 23 2 × 23 = 46 sulfur 32 oxygen 16 relative molecular mass = …… [2] [Total: 11]

Question

A student investigates the reaction of small pieces of calcium carbonate with dilute hydrochloric acid. The hydrochloric acid is in excess. CaCO3 + 2HCl → CaCl 2 + CO2 + H2O The rate of reaction is found by measuring the volume of carbon dioxide gas produced as time increases. The results are shown on the graph. 60 50 40 volume of carbon dioxide / cm3 30 20 10 0 0 10 20 30 40 50 60 70 time / s (a) Deduce the volume of carbon dioxide gas at 35 s. volume = …… cm3 [1] (b) The experiment is repeated at a higher temperature. All other conditions stay the same. Draw a line on the grid to show how the volume of carbon dioxide gas produced changes as time increases. [2] (c) Describe the effect each of the following has on the rate of reaction of calcium carbonate with dilute hydrochloric acid. All other conditions stay the same. ● The reaction is carried out using a higher concentration of hydrochloric acid. . …… ● The reaction is carried out using powdered calcium carbonate. . …… [2] (d) When 0.11 g of calcium carbonate is used, 25 cm3 of carbon dioxide gas is produced. Calculate the mass of calcium carbonate needed to produce 100 cm3 of carbon dioxide gas. mass of calcium carbonate = …… g [1] (e) State one use of calcium carbonate. . …… [1] [Total: 7] 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.).