Chemistry 0620/33 October/November 2023: question paper and mark scheme

Question

A list of substances is shown. ammonia calcium oxide carbon monoxide cobalt(II) chloride ethane ethanol ethene oxygen potassium oxide sodium sulfate sulfuric acid water Answer the following questions using only the substances from the list. Each substance may be used once, more than once or not at all. Give the name of the substance that: (a) is a product of photosynthesis . …… [1] (b) is a member of the alkene homologous series . …… [1] (c) has an ion with a charge of 1– . …… [1] (d) is used to remove sulfur dioxide in flue gas desulfurisation . …… [1] (e) is the product formed in a hydrogen–oxygen fuel cell . …… [1] (f) is used to test for water. . …… [1] [Total: 6]

Question

Hydrocarbons are compounds of carbon and hydrogen. (a) State the meaning of the term compound. . …… . …… [2] (b) Fig. 2.1 shows a fractionating column for separating petroleum into different hydrocarbon fractions. fraction refinery gas gasoline naphtha kerosene B fuel oil lubricating oil bitumen Fig. 2.1 (i) On Fig. 2.1, draw an X inside the column to show where the hydrocarbon with the highest boiling point collects. [1] (ii) Name the fraction labelled B in Fig. 2.1. . …… [1] (iii) State the name of the fraction which has hydrocarbons with the shortest chain length. . …… [1] (iv) State one use of the naphtha fraction. . …… [1] [Total: 6]

Question

(a) Table 3.1 shows the average concentrations, in ng / 1000 cm3, of air pollutants in four different years. Table 3.1 concentration of air pollutant in ng / 1000 cm3 year carbon oxides of hydrocarbons particulates sulfur dioxide monoxide nitrogen 2019 5.3 22.0 15.6 19.0 20.0 2020 4.1 13.5 14.8 20.1 18.2 2021 5.8 14.8 22.7 23.5 16.2 2022 2.6 18.0 10.9 26.2 14.0 (i) Name the pollutant which has the highest concentration in 2019. . …… [1] (ii) Name the pollutant that shows a continuous decrease in concentration from 2019 to 2022. . …… [1] (iii) Calculate the average mass, in ng, of hydrocarbons in a 200 cm3 sample of polluted air in 2019. mass = …… ng [1] (b) (i) State one source of oxides of nitrogen in the air. . …… [1] (ii) Oxides of nitrogen contribute to acid rain. Give one other effect of oxides of nitrogen in the air. . …… [1] (iii) Unpolluted water has a neutral pH. Choose from the list the pH value of a neutral substance. Draw a circle around your chosen answer. pH 1 pH 6 pH 7 pH 14[1] (c) Nitrogen dioxide is an acidic oxide. Choose an oxide from the list which is also an acidic oxide. Tick (✓) one box. copper(II) oxide magnesium oxide phosphorus(V) oxide sodium oxide [1] (d) Sulfur dioxide reacts with oxygen to produce sulfur trioxide. (i) Complete the symbol equation for this reaction. ……SO2 + …… 2SO3[2] (ii) State the meaning of the symbol . . …… [1] (iii) Sulfur trioxide reacts with calcium oxide to produce calcium sulfate. Describe a test for sulfate ions. test . …… observations …… [2] [Total: 12]

Question

Nitrogen is a gas at room temperature. (a) State two general properties of a gas. 1 . …… . …… 2 . …… . …… [2] (b) Fig. 4.1 shows the physical states of nitrogen. A solid liquid nitrogen nitrogen nitrogen gas B Fig. 4.1 Name the changes of physical states A and B. A …… B …… [2] (c) Describe solid nitrogen and nitrogen gas in terms of the arrangement and separation of the particles. solid nitrogen arrangement …… . …… separation . …… . …… nitrogen gas arrangement …… . …… separation . …… . …… [4] (d) A sealed gas syringe contains 80 cm3 of nitrogen gas. State how increasing the pressure affects the volume of nitrogen gas in the gas syringe when the temperature remains constant. . …… [1] [Total: 9]

Question

This question is about metals. (a) Table 5.1 shows some properties of the Group I metals. Table 5.1 melting point boiling point atomic volume observations on metal in °C in °C in cm3 / mol reaction with water bubbles form slowly lithium 181 1342 12.9 but no flame sodium 98 883 23.7 bubbles form very potassium 63 760 rapidly and flame seen rubidium 686 55.8 explodes Use the information in Table 5.1 to predict: (iii) the observations when sodium reacts with water …… . …… [1] (iv) the physical state of sodium at 1300 °C. Give a reason for your answer. physical state . …… reason . …… . …… [2] (b) Iron is extracted in a blast furnace by reduction of iron(III) oxide. (i) In the first step, carbon burns in air to form carbon dioxide. State the percentage of oxygen in clean, dry air. . …… [1] (ii) In the second step, carbon monoxide is produced by the reaction of carbon dioxide with carbon. CO2 + C → 2CO Choose the correct statement about this reaction. Tick (✓) one box. the carbon dioxide is oxidised and the carbon is reduced both carbon dioxide and carbon are oxidised the carbon dioxide is reduced and the carbon is oxidised both carbon dioxide and carbon are reduced [1] (iii) In the third step, iron(III) oxide is reduced by carbon monoxide. The reaction is exothermic. State the meaning of the term exothermic. . …… . …… [2] (c) Calcium carbonate is added to the blast furnace. The calcium carbonate breaks down as shown. high temperature calcium carbonate calcium oxide + carbon dioxide (i) Name the type of chemical reaction that takes place. . …… [1] (ii) Complete this sentence about the calcium oxide that is produced in the blast furnace. Calcium oxide reacts with impurities in the iron ore to form …… . [1] (d) Table 5.2 gives the observations when four different metals react with air. Table 5.2 metal observations cerium forms an oxide layer slowly without heating copper forms an oxide layer only when heated gold does not form an oxide layer even when heated rubidium forms an oxide layer quickly without heating Put the four metals in order of their reactivity. Put the least reactive metal first. least reactive most reactive [2] [Total: 13]

Question

Hydrogen peroxide, H2O2, breaks down slowly at 40 °C to produce oxygen gas and water. 2H2O2 → 2H2O + O2 A student investigates the breakdown of hydrogen peroxide at 40 °C in the presence of a catalyst. (a) Fig. 6.1 shows the volume of oxygen gas released as the reaction proceeds. 50 40 30 volume of oxygen gas / cm3 20 10 0 0 10 20 30 40 50 60 time / s Fig. 6.1 (i) Deduce the volume of oxygen gas released after 15 seconds. volume of oxygen = …… cm3 [1] (ii) The student repeats the experiment at 20 °C. All other conditions stay the same. Draw a line on the grid in Fig. 6.1 to show how the volume of oxygen changes when a temperature of 20 °C is used. [2] (b) (i) The student repeats the experiment without a catalyst. All other conditions stay the same. Describe how the rate of reaction differs when no catalyst is used. . …… [1] (ii) The student repeats the experiment using a lower concentration of hydrogen peroxide. All other conditions stay the same. Describe how the rate of reaction differs when a lower concentration of hydrogen peroxide is used. . …… [1] (c) Hydrogen peroxide can act as a reducing agent in the presence of an alkali. (i) State the meaning of the term alkali. . …… [1] (ii) Give the formula of the ion that is present in all alkaline solutions. . …… [1] (iii) State the colour of methyl orange in an alkaline solution. . …… [1] (iv) Aqueous ammonia is an alkali. Complete the word equation for the reaction of aqueous ammonia with hydrochloric acid. hydrochloric …… ammonia + → acid [1] [Total: 9]

Question

Ethanoic acid and methacrylic acid are both carboxylic acids. (a) Complete the word equation for the reaction of ethanoic acid with calcium. ethanoic …… …… + calcium → + acid [2] (b) Ethanoic acid can be reduced to ethanol. (i) Name the homologous series that includes ethanol. . …… [1] (ii) Ethanol can be manufactured by fermentation. Describe two conditions needed for fermentation. 1 . …… 2 . …… [2] (c) Fig. 7.1 shows the displayed formula of methacrylic acid. H H C H H O C C C H O H Fig. 7.1 (i) On Fig. 7.1, draw a circle around the functional group which reacts with aqueous bromine. [1] (ii) State the colour of aqueous bromine. . …… [1] (iii) Deduce the molecular formula of methacrylic acid. . …… [1] (d) Methacrylic acid can be converted to methyl methacrylate. The molecular formula of methyl methacrylate is C5H8O2. Complete Table 7.1 to calculate the relative molecular mass of methyl methacrylate. Table 7.1 number relative atom of atoms atomic mass carbon 5 12 5 × 12 = 60 hydrogen 1 oxygen 16 relative molecular mass = …… [2] (e) Methyl methacrylate can be polymerised to produce a plastic. Describe two environmental problems caused by plastics. 1 . …… 2 . …… [2] (f) Poly(ethene) is a polymer. Draw the displayed formula of the monomer used to make poly(ethene). [1] [Total: 13]

Question

Potassium chloride is an ionic compound. (a) Complete Fig. 8.1 to show: ● the electronic configuration of a potassium ion ● the charge on the ion. K Fig. 8.1 [2] (b) Deduce the number of protons and neutrons in the chloride ion shown. 17Cl 37 – number of protons …… number of neutrons …… [2] (c) Molten potassium chloride is electrolysed using graphite electrodes. (i) Define the term electrolysis. . …… . …… [2] (ii) State the names of the products at each electrode and give the observations at the positive electrode. product at the negative electrode …… product at the positive electrode . …… observations at the positive electrode . …… [3] (d) Graphite electrodes are inert. Name one other inert electrode. . …… [1] (e) Graphite and diamond are two forms of carbon. Fig. 8.2 shows the structure of diamond. Fig. 8.2 (i) Name the type of bonding in diamond. . …… [1] (ii) Use Fig. 8.2 to explain why diamond is used in cutting tools. . …… [1] [Total: 12] 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.).