Chemistry 0620/32 October/November 2024: question paper and mark scheme

Question

(a) Fig. 1.1 shows part of the Periodic Table. I II III IV V VI VII VIII H He N Na Al S Ar K Ca Zn Br I Ba Au Fig. 1.1 Answer the following questions using only the elements in Fig. 1.1. Each symbol of the element may be used once, more than once or not at all. Give the symbol of the element that: (i) is 78% of clean, dry air …… [1] (ii) forms an ion with a charge of 3+ …… [1] (iii) has an atom with only five occupied electron shells …… [1] (iv) forms an ion that gives a light green colour in a flame test …… [1] (v) is used in food containers because of its resistance to corrosion …… [1] (vi) is the metal with the lowest reactivity. …… [1] (b) Helium is a monatomic gas. (i) State the meaning of the term monatomic. …… [1] (ii) Explain in terms of electronic configuration why helium is unreactive. …… [1] [Total: 8]

Question

(a) Hydrogen chloride has a simple molecular structure. (i) State two physical properties of a compound with a simple molecular structure. 1 …… 2 …… [2] (ii) Hydrogen chloride is a molecule with a covalent bond. Complete this sentence about a covalent bond. A covalent bond is formed when two atoms share a pair of …… . [1] (iii) Complete Fig. 2.1 to show the dot-and-cross diagram for a molecule of hydrogen chloride. Show outer shell electrons only. H Cl Fig. 2.1 [2] (b) Zinc chloride has a giant ionic structure of positive and negative ions. State the general name given to any negative ion. …… [1] (c) Diamond is used for jewellery. (i) State one other use of diamond. …… [1] (ii) Choose the correct statement that describes the structure and bonding in diamond. Tick (✓) one box. simple covalent molecule giant covalent simple ionic giant ionic [1] [Total: 8]

Question

(a) The list shows some substances present in water from natural sources. dissolved oxygen calcium compounds plastics harmful microbes State which one of these substances provides essential minerals for aquatic life. …… [1] (b) Explain why phosphates present in polluted water are harmful to aquatic life. …… [1] (c) Table 3.1 shows the masses of ions, in mg, present in a 1000 cm3 sample of polluted water. Table 3.1 mass of ion in 1000 cm3 name of ion formula of ion of polluted water / mg bromide Br – 0.3 calcium Ca2+ 2.5 chloride Cl – 3.5 hydrogencarbonate HCO3– 10.0 magnesium Mg2+ 0.8 mercury Hg2+ 0.1 NO3– 0.4 phosphate PO43– 2.0 potassium K+ 5.9 silicate SiO32– 4.0 sodium Na+ 12.2 sulfate SO42– 0.5 Answer these questions using the information from Table 3.1. (i) Name the negative ion present in the highest concentration. …… [1] (ii) State the name of the NO3– ion. …… [1] (iii) Calculate the mass of phosphate ions present in 200 cm3 of polluted water. mass = …… mg [1] (d) Fig. 3.1 shows some of the stages in the purification of drinking water. addition of addition of sedimentation → filtration → → carbon chlorine Fig. 3.1 (i) State the purpose of sedimentation. …… [1] (ii) State why chlorine is added to drinking water. …… [1] (e) Describe how to test for the purity of water using boiling point. …… [2] (f) Complete the symbol equation for the reaction of disulfur dichloride, S2Cl 2, with water. S2Cl 2 + ……H2O → ……HCl + H2SO3 + H2S [2] [Total: 11]

Question

(a) Fig. 4.1 shows the displayed formula of compound A. O H H C C C O H H O H C O O H Fig. 4.1 (i) On Fig 4.1 draw a circle around the alcohol functional group. [1] (ii) Deduce the molecular formula of compound A. …… [1] (b) Compound A reacts with ethanol to produce a compound with the molecular formula C8H14O5. Complete Table 4.1 to calculate the relative molecular mass of C8H14O5. Table 4.1 relative type of atom number of atoms atomic mass carbon 8 12 8 × 12 = 96 hydrogen 1 oxygen 16 relative molecular mass = …… [2] (c) Complete the word equation for the complete combustion of ethanol. ethanol + oxygen → + [2] (d) Table 4.2 shows the names, formulae and boiling points of ethene, propene, butene and pentene. Table 4.2 boiling point name formula / °C ethene C2H4 –104 propene C 3H 6 – 47 butene C4 H 8 –6 pentene C5H10 +30 Use the information in Table 4.2 to answer these questions. (i) Name the homologous series that includes ethene, propene, butene and pentene. …… [1] (ii) Deduce the general formula of this homologous series. …… [1] (iii) State the trend in the boiling point of this homologous series as the number of carbon atoms increases. …… [1] (e) Ethene is manufactured by cracking. (i) Describe the manufacture of ethene by cracking. …… [3] (ii) Give a reason for cracking hydrocarbons. …… [1] [Total: 13]

Question

(a) Table 5.1 shows some properties of five halogens. Table 5.1 melting point boiling point density in liquid halogen in °C in °C state in g / cm3 fluorine –220 –188 chlorine –101 –35 1.56 bromine –7 +59 3.12 iodine +114 3.96 astatine +302 +337 6.40 Use the information in Table 5.1 to predict: (i) the boiling point of iodine …… [1] (ii) the density of liquid fluorine …… [1] (iii) the physical state of chlorine at –20 °C. Give a reason for your answer. physical state …… reason …… [2] (b) Aqueous chlorine reacts with aqueous lithium bromide. (i) Complete the word equation for this reaction. lithium …… …… chlorine + → + bromide [2] (ii) Explain why aqueous iodine does not react with aqueous lithium bromide. …… [1] (iii) Describe a test for chlorine. test …… observations …… [2] (c) Fluorine reacts with ammonia to produce hydrogen fluoride and nitrogen. Complete the symbol equation for this reaction. ……F2 + 2NH3 → ……HF + N2 [2] [Total: 11]

Question

This question is about metals. (a) Many metals have high melting points and boiling points. State three other typical physical properties of metals. 1 …… 2 …… 3 …… [3] (b) (i) Complete Table 6.1 to show the number of electrons, neutrons and protons in the sodium atom and silver ion shown. Table 6.1 number of number of number of electrons neutrons protons 23 11Na 11 109 + 47Ag 62 [3] (ii) Write the electronic configuration of the sodium atom. …… [1] (c) Silver is a transition element. Sodium is in Group I of the Periodic Table. State one difference in the physical properties of silver and sodium. …… [1] (d) Table 6.2 shows the observations when four different metals are heated in oxygen. Table 6.2 metal observations when heated in oxygen cerium burns rapidly and forms an oxide copper forms an oxide layer very slowly and does not burn lanthanum forms an oxide layer rapidly and does not burn silver does not form an oxide layer and does not burn Put the four metals in order of their reactivity. Put the least reactive metal first. least reactive most reactive [2] (e) Copper(II) oxide is reduced by carbon monoxide. CuO + CO → Cu + CO2 Explain how this equation shows that copper(II) oxide is reduced. …… [1] [Total: 11]

Question

This question is about acids, bases and salts. (a) Crystals of zinc sulfate are made by warming excess solid zinc oxide with dilute sulfuric acid. ZnO(s) + H2SO4(aq) → ZnSO4(aq) + H2O(l) (i) State the meaning of the state symbol (aq). …… [1] (ii) State the method used to separate the excess solid zinc oxide from the reaction mixture. …… [1] (b) Crystals of sodium nitrate can be made by neutralising an acid with an alkali. (i) Name the acid and the alkali used. acid …… alkali …… [2] (ii) Complete the equation for all neutralisation reactions. H+ + …… → …… [2] (iii) Neutralisation reactions are exothermic. Define the term exothermic. …… [1] (iv) Fig. 7.1 shows the reaction pathway diagram for an exothermic reaction. reactants energy products progress of reaction Fig. 7.1 Explain how Fig. 7.1 shows that the reaction is exothermic. …… [1] (c) Methyl orange is an acid–base indicator. State the colour of methyl orange at pH 2 and at pH 12. colour at pH 2 …… colour at pH 12 …… [2] [Total: 10]

Question

(a) A student investigates the reaction of small pieces of calcium carbonate with excess dilute hydrochloric acid of three different concentrations. The time taken for each reaction to finish is recorded. The three concentrations of acid are: ● 0.5 mol / dm3 ● 1.0 mol / dm3 ● 2.0 mol / dm3. All other conditions stay the same. Table 8.1 shows the time taken for each reaction to finish. Table 8.1 concentration of time taken for the dilute hydrochloric acid reaction to finish in mol / dm3 in s 32 64 16 (i) Complete Table 8.1 by writing the concentrations in the first column. [1] (ii) Describe the effect on the time taken for the reaction to finish when the reaction is carried out at a lower temperature. All other conditions stay the same. …… [1] (iii) Describe the effect on the time taken for the reaction to finish when powdered calcium carbonate is used instead of small pieces of calcium carbonate. All other conditions stay the same. …… [1] (b) Molten calcium chloride is electrolysed using inert electrodes. (i) Name the products at the positive and negative electrodes. product at the positive electrode …… product at the negative electrode …… [2] (ii) Choose from the list the substance that is used as an inert electrode. Draw a circle around your chosen answer. graphite iodine magnesium phosphorus [1] (c) Carbon dioxide is a gas at room temperature. Describe the motion and separation of the particles in carbon dioxide gas. motion …… separation …… [2] [Total: 8] 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 89–103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 actinoids Fr Ra Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og francium radium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson – – – – – – – – – – – – – – – – – 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.).