5 Iron pyrite, FeS2, is an ore of iron. When heated in air, FeS2 produces both iron(III) oxide and sulfur dioxide. (a) Balance the equation shown. ………. FeS2 + ………. O2 ………. Fe2O3 + ……… SO2 [1] (b) Describe one environmental problem caused by sulfur dioxide in the air. … [1] (c) Describe how sulfur dioxide is converted into sulfuric acid in the contact process. … … … … … [3] (d) State one other use of sulfur dioxide. … [1] (e) Iron(III) oxide, coke, limestone and hot air are heated together in a blast furnace to make molten iron. Describe the function in the blast furnace of: (i) coke … … [1] (ii) limestone … … [1] (iii) hot air. … … [1] [Total: 9] Section B Answer three questions from this section in the spaces provided. The total mark for this section is 30.

5(a) 4FeS2 + 11O2 → 2Fe2O3 + 8SO2 1 5(b) acid rain / erodes buildings / corrodes buildings 1 5(c) sulfur dioxide reacted with oxygen to make sulfur trioxide (1) this reaction uses a V2O5 catalyst / temperatures between 450 and 600 °C / 1 to 10 atmosphere pressure (1) sulfur trioxide reacted with H2SO4(l) to make oleum which is then reacted with water (to make sulfuric acid) (1) 3 5(d) bleaching (wood pulp) / preservative 1 5(e)(i) reacts with oxygen to provide energy for the reaction / makes carbon monoxide / reduces carbon dioxide 1 5(e)(ii) (decomposes) to make calcium oxide (which removes impurities) 1 5(e)(iii) provides oxygen for the coke to burn / makes carbon dioxide from (coke) 1 To earn marks, you must correctly balance the chemical equation, describe an environmental problem caused by sulfur dioxide, detail the three key steps of the Contact Process (reaction of SO2 with O2, catalyst/conditions, and reaction of SO3 with H2SO4 then water), state another use for sulfur dioxide, and explain the role of coke, limestone, and hot air in the blast furnace.

5 Magnesium undergoes oxidation when it reacts with aqueous silver nitrate. Mg + 2Ag+ Mg2+ + 2Ag (a) Explain how this equation shows that magnesium is oxidised. … … [1] (b) The reaction of magnesium with silver nitrate is exothermic. Complete the energy profile diagram for this reaction. Label reactants, products and ∆H. progress of reaction energy [2] (c) Acidified aqueous silver nitrate is added to a solution containing halide ions. A yellow precipitate is observed. State the name of the halide ion present in the solution. … [1] (d) Silver is a metal. Use your knowledge of the structure of metals to explain why silver is malleable. … … … [2] (e) The table gives information about the thermal decomposition of some metal carbonates. metal carbonate ease of thermal decomposition calcium carbonate decomposes at 900 °C magnesium carbonate decomposes at 540 °C sodium carbonate does not decompose below 1000 °C Describe how the ease of thermal decomposition depends on the position of these metals in the reactivity series. … … [1] [Total: 7]

5(a) (magnesium) loses electrons (1) 1 5(b) reactants on the left and products on the right and reactant line above product line (1) arrow downwards between reactants and products with ∆H label (1) 2 5(c) iodide 1 5(d) layers made of ions (1) layers slide (1) 2 5(e) more reactive the metal (in the carbonate) the harder it is to break down (the carbonate) 1 (a) To earn the mark, you must explain that magnesium loses electrons. (b) To earn the first mark, you must draw reactants on the left and products on the right, with the reactant line above the product line. To earn the second mark, you must draw a downward arrow between reactants and products and label it ∆H. (c) To earn the mark, you must state 'iodide' as the halide ion. (d) To earn the first mark, you must state that metals have layers of ions. To earn the second mark, you must explain that these layers can slide. (e) To earn the mark, you must state that the more reactive the metal in the carbonate, the harder it is to break down the carbonate.

8 Lead is a metal with proton number 82. (a) (i) Use the Periodic Table to state the number of occupied electron shells in an atom of lead. … [1] (ii) Use the Periodic Table to state the number of electrons in the outer shell of an atom of lead. … [1] (b) Describe, with the aid of a labelled diagram, the metallic bonding in lead. … … … … [3] (c) Give two physical properties of lead that are characteristic of all metals. 1. … 2. … [1] (d) Lead(II) ethanoate is a white crystalline soluble salt. Name a suitable combination of an acid and an insoluble base which is used to prepare lead(II) ethanoate. acid … base … [1] (e) Aqueous lead(II) ethanoate reacts with aqueous sodium iodide. A yellow precipitate of lead(II) iodide, PbI2, is formed. Construct the ionic equation, with state symbols, for this reaction. … [2] (f) Explain why solid lead(II) iodide cannot be electrolysed. … … … [1] [Total: 10]

8(a)(i) six 1 8(a)(ii) four 1 8(b) closely packed positive ions in regular arrangement (1) delocalised electrons / sea of electrons (1) strong attraction between the (positive) ions and the electrons (1) 3 8(c) Any two for one mark: (1) good electrical conductor good thermal conductor shiny / lustrous malleable ductile/ can be made into wires 1 8(d) ethanoic acid and lead(II) oxide or lead(II) hydroxide 1 delocalised electron positive ion 8(e) Pb2+(aq) + 2I−(aq) → PbI2(s) correct formulae for reactants and products and balanced (1) state symbols dependent on correct formulae (1) 2 8(f) ions cannot move / no mobile ions 1

2 A student investigates the reaction between zinc and dilute sulfuric acid. The equation for the reaction is shown. Zn(s) + H2SO4(aq) ZnSO4(aq) + H2(g) (a) The student observes bubbles of a gas being produced when zinc is added to dilute sulfuric acid. The student does a test to show that the gas is hydrogen. (i) Give a test and observation to identify hydrogen gas. test … observation … [1] (ii) State one other observation the student makes when zinc is added to dilute sulfuric acid. … [1] A student does an experiment to find out how the rate of this reaction changes as the temperature of the dilute sulfuric acid changes. Method The student: • measures 100 cm3 of 1.0 mol / dm3 dilute sulfuric acid (an excess) and pours this into a beaker • places a thermometer in the acid • heats the acid to the required temperature • removes the heat • adds a known mass of zinc to the acid • immediately starts a clock • stops the clock when all the zinc has reacted • records this reaction time. The student repeats the experiment several times at different temperatures. All other variables likely to affect the rate of reaction are kept constant in each experiment. The results are shown in the table. experiment temperature / °C reaction time / s 1 30 150 2 40 80 3 50 45 4 60 90 5 70 2 (b) (i) State which experiment has an anomalous reaction time. … [1] (ii) Suggest what the student should do to check if the reaction time in (b)(i) is anomalous. … [1] (iii) State which experiment has the greatest rate of reaction. … [1] (iv) Describe how the rate of this reaction changes as the temperature of the dilute sulfuric acid increases. … [1] (c) Another student does the reaction at 90 °C. State why it is difficult to measure an accurate reaction time at 90 °C. … [1] (d) Suggest two variables, other than the temperature of the dilute sulfuric acid or the mass of zinc, that affect the rate of this reaction. 1 … 2 … [2] [Total: 9]

2(a)(i) burning splint pops 1 2(a)(ii) Any one from: heat given out (1) solid dissolves or disappears (1) 1 2(b)(i) 4 1 2(b)(ii) repeat experiment at 60 °C / repeat experiment 4 / plot a graph and see if the point lies on the line or curve 1 2(b)(iii) 5 1 2(b)(iv) rate increases 1 2(c) time would be too small to measure 1 2(d) Any two from: particle size of zinc / surface area of zinc (1) concentration of sulfuric acid (1) catalyst (1) 2 (a)(i) To earn the mark, you must state 'burning splint' as the test and 'pops' as the observation. (a)(ii) To earn the mark, you must state either 'heat given out' or 'solid dissolves/disappears' as an observation. (b)(i) To earn the mark, you must state '4' as the experiment number. (b)(ii) To earn the mark, you must suggest repeating experiment 4 or repeating the experiment at 60°C, or plotting a graph to check if the point lies on the line/curve. (b)(iii) To earn the mark, you must state '5' as the experiment number. (b)(iv) To earn the mark, you must state that the 'rate increases'. (c) To earn the mark, you must state that the 'time would be too small to measure'. (d) To earn the marks, you must state any two from 'particle size of zinc/surface area of zinc', 'concentration of sulfuric acid', or 'catalyst'.

Cambridge O Level Chemistry · 5070

O-Level Chemistry (5070) Metals past paper questions

Revise O-Level Chemistry (5070) — Metals with real Cambridge past-paper questions grouped by topic, each shown with its marking scheme. Working one topic at a time targets exactly the skill each question tests.

148 free questions from 2016–2021, each with its marking scheme. Open the full topical bank to filter by subtopic, paper, and year.

Metals in O-Level Chemistry 5070 exams, 2020–2025

Across 2020–2025, Metals accounted for 136 questions worth 549 marks in Cambridge O Level Chemistry (5070) papers.

By year
Year	Questions	Marks
2020	24	86
2021	23	68
2022	18	119
2023	25	75
2024	23	121
2025	23	80

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Paper 1 · 87 qs
Paper 2 · 34 qs
Paper 3 · 4 qs
Paper 4 · 11 qs

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2021 May/Jun · Paper 2 · Q5 · 9 marks
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2021 Oct/Nov · Paper 2 · Q5 · 7 marks
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2021 May/Jun · Paper 2 · Q8 · 10 marks
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2021 Oct/Nov · Paper 4 · Q2 · 9 marks
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2021 May/Jun · Paper 1 · Q29 · 1 mark
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Mark scheme — 2021 Paper 1 Q29
Answer: B
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