Chemistry 0620/31 October/November 2023: question paper and mark scheme

Question

A list of substances is shown. ammonium nitrate carbon monoxide copper(II) chloride ethane ethene litmus methane methyl orange sodium chloride sodium sulfate sulfur dioxide thymolphthalein 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) turns from blue to colourless when an acid is added . …… [1] (b) is in many fertilisers . …… [1] (c) is a salt which has a negative ion with a charge of 2– . …… [1] (d) is a waste gas from digestion in animals . …… [1] (e) is a hydrocarbon with a total of five atoms in a molecule . …… [1] (f) is a compound of a transition element. . …… [1] [Total: 6]

Question

(a) Fig. 2.1 shows the distillation apparatus that can be used to separate water from aqueous copper(II) sulfate. thermometer condenser distillation flask aqueous copper(II) sulfate water heat Fig. 2.1 Explain how distillation separates water from aqueous copper(II) sulfate. . …… . …… . …… [2] (b) Fig. 2.2 shows a fractionating column for separating petroleum into different hydrocarbon fractions. fraction refinery gas gasoline naphtha A diesel oil fuel oil lubricating oil bitumen Fig. 2.2 (i) On Fig. 2.2, draw an X inside the column to show where the hydrocarbon with the highest viscosity collects. [1] (ii) Name the fraction labelled A in Fig. 2.2. . …… [1] (iii) State the name of the fraction in Fig. 2.2 which has the lowest boiling point. . …… [1] (iv) State one use of the bitumen 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 oxides of ammonia hydrocarbons particulates sulfur dioxide nitrogen 2019 10.6 12.0 15.3 30.1 20.5 2020 11.2 13.0 21.6 28.2 20.0 2021 14.3 15.2 23.5 26.5 25.0 2022 15.5 9.0 14.0 25.2 18.2 (i) Name the pollutant that has the lowest 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 sulfur dioxide in a 250 cm3 sample of polluted air in 2020. mass = …… ng [1] (b) (i) State one source of sulfur dioxide in the atmosphere. . …… [1] (ii) State one adverse effect of sulfur dioxide in the atmosphere. . …… [1] (iii) Choose the compound used to remove sulfur dioxide in flue gas desulfurisation. Tick (✓) one box. aluminium chloride calcium oxide methane sulfuric acid [1] (iv) Hydrochloric acid reacts with sodium sulfite. The products are sodium chloride, sulfur dioxide and a liquid which turns anhydrous cobalt(II) chloride pink. Complete the symbol equation for this reaction. Na2SO3 + ……HCl → 2NaCl + SO2 + …… [2] (v) Name the acidified solution used to test for sulfur dioxide gas and state the observations. acidified solution …… observations …… [2] (c) Ammonia forms an alkaline solution in water. (i) Give the formula of the ion that is present in all alkaline solutions. . …… [1] (ii) Choose from the list the pH value for an alkaline solution. Draw a circle around your chosen answer. pH 1 pH 4 pH 7 pH 13[1] [Total: 12]

Question

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

Question

This question is about metals and metal compounds. (a) Table 5.1 shows some properties of some Group I metals. Table 5.1 solubility of metal melting point boiling point observations on metal hydroxide in g / dm3 in °C in °C reaction with water at room temperature bubbles form rapidly sodium 98 883 but no flame potassium 63 760 1130 rubidium 686 explodes 1980 caesium 29 669 explodes 3860 Use the information in Table 5.1 to predict: (iii) the observations when potassium reacts with water . …… . …… [1] (iv) the physical state of caesium at 20 °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, Fe2O3, with carbon monoxide. Carbon monoxide is produced by the reaction of carbon with carbon dioxide. C + CO2 → 2CO (i) Explain how this equation shows that carbon dioxide is reduced. . …… . …… [1] (ii) Name the type of chemical reaction where oxidation and reduction take place simultaneously. . …… [1] (iii) Calcium carbonate is added to the blast furnace. The calcium carbonate undergoes thermal decomposition. State the meaning of the term thermal decomposition. . …… . …… [2] (c) Stainless steel is an alloy of iron. (i) Give one reason why alloys are more useful than pure metals. . …… [1] (ii) Brass is an alloy. Choose the diagram, A, B, C or D, in Fig. 5.1 that best shows the structure of brass. Zn Cu Cu Zn Cu Zn Fe Cu Zn Fe Fe Zn Fe Zn Cu Zn Cu Zn Zn Cu Zn Cu Fe Fe Zn Fe Fe Fe Zn Zn Cu Cu Zn Cu Zn Cu Cu Zn Zn Zn Fe Fe Fe Cu Zn Cu A B C D Fig. 5.1 diagram . …… [1] (d) Table 5.2 gives some observations about the reactivity of four metals with dilute hydrochloric acid. Table 5.2 metal observations iron bubbles form slowly magnesium bubbles form very quickly mercury no bubbles form tin bubbles form very slowly Put the four metals in order of their reactivity. Put the least reactive metal first. least reactive most reactive [2] [Total: 13]

Question

A student investigates the reaction of large pieces of magnesium carbonate with dilute hydrochloric acid at 20 °C. The magnesium carbonate is in excess. (a) Fig. 6.1 shows the volume of carbon dioxide gas released as the reaction proceeds. 60 50 40 volume of carbon dioxide gas / cm3 30 20 10 0 0 1 2 3 4 5 6 7 time / min Fig. 6.1 (i) Deduce the volume of carbon dioxide gas released after 2 minutes. volume of carbon dioxide = …… cm3 [1] (ii) The student repeats the experiment using the same volume of hydrochloric acid but with a higher concentration. The magnesium carbonate is still in excess. All other conditions stay the same. Draw a line on the grid in Fig. 6.1 to show the volume of carbon dioxide released when hydrochloric acid with a higher concentration is used. [2] (b) (i) The student repeats the experiment using smaller pieces of magnesium carbonate. All other conditions stay the same. Describe how the rate of reaction differs when smaller pieces of magnesium carbonate are used. . …… [1] (ii) The student repeats the experiment at 10 °C. All other conditions stay the same. Describe how the rate of reaction differs when the temperature is 10 °C. . …… [1] (c) Hydrochloric acid reacts with iron. Complete the word equation for this reaction. hydrochloric …… …… + iron → + acid [2] (d) Acids are used as catalysts in many chemical reactions. State the meaning of the term catalyst. . …… . …… [2] [Total: 9]

Question

(a) Fig. 7.1 shows the displayed formula of compound S. H H C O H H C H C O O H Fig. 7.1 (i) On Fig. 7.1, draw a circle around the carboxylic acid functional group. [1] (ii) Deduce the molecular formula of compound S. . …… [1] (b) Compound S can be converted to acrylic acid. The molecular formula of acrylic acid is C3H4O2. (i) Complete Table 7.1 to calculate the relative molecular mass of acrylic acid. Table 7.1 number relative atom of atoms atomic mass carbon 3 12 3 × 12 = 36 hydrogen 1 oxygen 16 relative molecular mass = …… [2] (ii) Acrylic acid is an unsaturated compound. Describe a test for an unsaturated compound. test . …… observations …… [2] (iii) When left in the air, acrylic acid forms a polymer. State the meaning of the term polymer. . …… . …… [2] (iv) Poly(ethene) is also a polymer. Choose from the list the type of polymerisation that occurs when poly(ethene) is made. Draw a circle around your chosen answer. substitution oxidation neutralisation addition[1] (c) Ethanoic acid is a carboxylic acid. Complete the word equation for the reaction of ethanoic acid with sodium hydroxide. ethanoic sodium …… …… + → + acid hydroxide [2] (d) Ethanoic acid can be converted to ethanol. Name the two products formed when ethanol undergoes complete combustion. [Total: 13]

Question

Lithium bromide is a compound with ionic bonding. (a) State the meaning of the term ionic bond. . …… . …… [2] (b) Complete Fig. 8.1 to show: ● the electronic configuration of a lithium ion ● the charge on the ion. Li Fig. 8.1 [2] (c) Deduce the number of protons and neutrons in the bromide ion shown. 35Br 79 – number of protons …… number of neutrons …… [2] (d) Molten lithium bromide is electrolysed using graphite electrodes. State the names of the product 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] (e) Fig. 8.2 shows the structure of graphite. Fig. 8.2 (i) State the type of bonding in graphite. . …… [1] (ii) Explain by referring to Fig. 8.2 why graphite is used as a lubricant. . …… [1] (iii) Graphite and diamond are both forms of carbon. State one use of diamond. . …… [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.).