Chemistry 0620/33 May/June 2023: question paper and mark scheme

Question

Fig. 1.1 shows part of the Periodic Table. I II III IV V VI VII VIII Li C N O F Al Ar Ca Cr Fe Cu Br I 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: (a) is present in diamond . …… [1] (b) forms an oxide that contributes to acid rain . …… [1] (c) has an atom with five occupied electron shells . …… [1] (d) forms an ion with a charge of 1+ . …… [1] (e) forms an ion that gives a red-brown precipitate on addition of aqueous ammonia . …… [1] (f) is used in the manufacture of aircraft because of its low density. . …… [1] [Total: 6]

Question

(a) Table 2.1 shows some properties of the halogens. Table 2.1 density at room melting point boiling point halogen temperature and in °C in °C pressure in g / cm3 fluorine –220 –188 chlorine –101 0.003 bromine –7 +59 3.12 iodine +114 +184 4.93 Use the information in Table 2.1 to predict: (iii) the physical state of iodine at +100 °C. Give a reason for your answer. physical state . …… reason . …… . …… [2] (b) Aqueous chlorine reacts with aqueous sodium bromide. (i) Complete the word equation for this reaction. sodium …… chlorine + → …… + bromide [2] (ii) State a test for sodium ions. test . …… observations …… [2] [Total: 8]

Question

(a) Polluted water can contain harmful substances such as metal compounds, nitrates and sewage. (i) Name two other substances present in polluted water which are harmful to aquatic life. 1 . …… 2 . …… [2] (ii) State why sewage can cause disease. . …… [1] (b) Table 3.1 shows the masses of ions, in mg, present in 1000 cm3 of polluted water. Table 3.1 mass of ion present formula name of ion in mg / 1000 cm3 of of ion polluted water ammonium NH4+ 1.2 calcium Ca2+ 2.2 chloride Cl – 2.5 hydrogencarbonate HCO3– 13.0 magnesium Mg2+ 1.0 nickel(II) Ni2+ 0.2 nitrate NO3– 0.4 potassium K+ 6.3 silicate SiO32– 8.0 sodium Na+ 12.2 SO42– 0.1 Answer these questions using information from Table 3.1. (i) Name the positive ion present in the lowest concentration. . …… [1] (ii) State the name of the ion SO42–. . …… [1] (iii) Calculate the mass of calcium ions present in 250 cm3 of polluted water. mass = …… mg [1] (c) Cobalt(II) chloride can be used to test for the presence of water. CoCl 2(s) + 6H2O(l) CoCl 2•6H2O(s) blue cobalt(II) pink cobalt(II) chloride chloride (i) Describe how pink cobalt(II) chloride can be changed to blue cobalt(II) chloride. . …… [1] (ii) Choose a word from the list which best describes pink cobalt(II) chloride. Draw a circle around your chosen answer. anhydrous hydrated liquid reduced[1] (d) Iron reacts with steam to form Fe3O4 and a gas which pops with a lighted splint. Complete the symbol equation for this reaction. 3Fe + ……H2O → Fe3O4 + 4…… [2] [Total: 10]

Question

This question is about bromine and compounds of bromine. (a) Deduce the number of protons, neutrons and electrons in the bromide ion shown. 35Br 81 – number of protons …… number of neutrons …… number of electrons . …… [3] (b) Hydrogen bromide decomposes to hydrogen and bromine when heated. Fig. 4.1 shows an incomplete reaction pathway diagram for this reaction. energy progress of reaction Fig. 4.1 (i) Complete Fig. 4.1 by writing these formulae on the diagram: ● 2HBr ● H2 + Br2.[1] (ii) Explain how Fig. 4.1 shows that the reaction is endothermic. . …… . …… [1] (iii) Complete this sentence about an endothermic reaction using a word from the list. products reactants bromine surroundings An endothermic reaction transfers thermal energy from the …… . [1] (c) Hydrobromic acid is formed when hydrogen bromide dissolves in water. (i) Write the formula of the ion which is present in all acids. . …… [1] (ii) Complete the word equation for the reaction of any acid with any carbonate. acid + carbonate → …… + …… + [3] (iii) A few drops of litmus indicator are added to a dilute acid. State the colour of the solution. . …… [1] (d) Fig. 4.2 shows the apparatus used for the electrolysis of molten lead(II) bromide using graphite electrodes. – power + supply Fig. 4.2 (i) Label Fig. 4.2 to show: ● the cathode ● the electrolyte. [2] (ii) Name the products and state the observations at the positive and negative electrodes. product at the positive electrode . …… observations at the positive electrode . …… product at the negative electrode . …… observations at the negative electrode . …… [4] (iii) State one property of graphite that makes it useful as an electrode. . …… [1] [Total: 18]

Question

This question is about metals. (a) Nickel is a transition element. Sodium is an element in Group I of the Periodic Table. State two differences in the physical properties of nickel compared to sodium. 1 . …… 2 . …… [2] (b) Stainless steel is an alloy that is used to make cutlery. Give one reason why stainless steel is used to make cutlery. . …… [1] (c) Table 5.1 shows some information about the reaction of four metals with oxygen. Table 5.1 metal reaction with oxygen gold no reaction lanthanum forms a layer of oxide rapidly but does not burn magnesium burns rapidly to form an oxide nickel forms a layer of oxide slowly but does not burn Put the four metals in order of their reactivity. Put the least reactive metal first. least reactive most reactive [2] (d) Complete the diagram in Fig. 5.1 to show the electronic configuration of a magnesium atom. Mg Fig. 5.1 [1] [Total: 6]

Question

(a) A student investigates the reaction of magnesium with dilute hydrochloric acid at three different temperatures. The temperatures are: ● 20 °C ● 30 °C ● 40 °C. All other conditions stay the same. Table 6.1 shows the time taken for each reaction to finish. Table 6.1 temperature time taken for the / °C reaction to finish / s 45 210 95 (i) Complete Table 6.1 by writing the temperatures in the first column. [1] (ii) Describe the effect on the time taken for the magnesium to finish reacting with dilute hydrochloric acid when the surface area of the magnesium is increased. All other conditions stay the same. . …… [1] (iii) Describe the effect on the time taken for the magnesium to finish reacting with dilute hydrochloric acid when the concentration of acid is decreased. All other conditions stay the same. . …… [1] (b) Describe how crystals of magnesium chloride can be prepared after reacting excess magnesium with dilute hydrochloric acid. . …… . …… . …… [2] (c) Magnesium chloride is soluble in water. Choose one other compound that is soluble in water. Tick (✓) one box. ammonium sulfate calcium carbonate iron(II) hydroxide silver chloride [1] [Total: 6]

Question

(a) Fig. 7.1 shows the displayed formula of compound E. H H C H C H C H C H O H H Fig. 7.1 (i) On Fig. 7.1 draw a circle around the functional group that makes compound E unsaturated. [1] (ii) Deduce the molecular formula of compound E. . …… [1] (iii) Describe a chemical test to distinguish between a saturated and an unsaturated compound. test . …… observations with saturated compound …… . …… observations with unsaturated compound …… . …… [3] (b) Alcohols have an –OH functional group. (i) Write the general formula for the alcohol homologous series. . …… [1] (ii) Ethanol is an alcohol with two carbon atoms in each molecule. Draw the displayed formula of ethanol. [1] (c) Ethanol reacts to form a compound with the formula C6H12O2. Complete Table 7.1 to calculate the relative molecular mass of C6H12O2. Table 7.1 relative atom number of atoms atomic mass carbon 6 12 6 × 12 = 72 hydrogen 1 oxygen 16 relative molecular mass = …… [2] (d) Ethanol can be manufactured by the fermentation of aqueous glucose. State two conditions for fermentation. 1 . …… 2 . …… [2] (e) Ethanol can be oxidised to ethanoic acid. Complete the word equation for the reaction of ethanoic acid with sodium. ethanoic …… + sodium → + …… acid [2] [Total: 13]

Question

This question is about non-metals. (a) Non-metals are poor thermal conductors. Describe two other physical properties which are typical of non-metals. 1 . …… 2 . …… [2] (b) Carbon dioxide contributes to increased global warming which leads to climate change. State two strategies which help to reduce climate change caused by carbon dioxide. 1 . …… 2 . …… [2] (c) Water is a simple molecular compound. (i) Complete Fig. 8.1 to show the dot-and-cross diagram for a molecule of water. Show outer shell electrons only. O H H Fig. 8.1 [2] (ii) State two properties of simple molecular compounds. 1 . …… 2 . …… [2] (iii) Water is a good solvent. State the meaning of the term solvent. . …… [1] (iv) Pure water has a neutral pH value. Choose from the list, the pH value that is neutral. Draw a circle around your chosen answer. pH 1 pH 3 pH 7 pH 14[1] (v) A crystal of blue copper(II) sulfate is placed at the bottom of a beaker of water as shown in Fig. 8.2. water crystal of copper(II) sulfate at first after one day Fig. 8.2 After one day, the blue colour has spread throughout the water in the beaker. Explain these results in terms of the kinetic particle theory. . …… . …… . …… . …… [3] [Total: 13] 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.).