Extraction of metals — Paper 2 · IGCSE Chemistry (9-1) 0971

26 Aluminium metal is extracted from aluminium oxide using electrolysis. Which statement about the extraction process is not correct? A A large amount of electricity is required. B Molten cryolite is used to dissolve the aluminium oxide. C Oxygen gas is released which reacts to form carbon dioxide. D The negative electrodes burn away and have to be replaced.

1 marks

Answer: D

This question in 0971/21 May/June 2018

24 Heating copper(II) carbonate produces copper(II) oxide and carbon dioxide. Heating the copper(II) oxide formed with carbon produces copper. Which processes are involved in this conversion of copper(II) carbonate to copper? A sublimation followed by oxidation B sublimation followed by reduction C thermal decomposition followed by oxidation D thermal decomposition followed by reduction

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2018

27 Bauxite contains aluminium oxide. Aluminium is extracted from aluminium oxide by electrolysis. Why is cryolite added to the electrolytic cell used to extract aluminium? A Cryolite prevents the carbon anodes being burned away. B Cryolite removes impurities from the bauxite. C Cryolite increases the rate at which aluminium ions are discharged. D Molten cryolite dissolves the aluminium oxide.

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2018

10 Aluminium metal is extracted from aluminium oxide by electrolysis. Which ionic half-equation describes a reaction that occurs at the named electrode? ionic half-equation electrode A 2O2– → O2 + 2e– anode B Al 3+ + 3e– → Al anode C 2O2– → O2 + 4e– cathode D Al 3+ + 3e– → Al cathode

1 marks

Answer: D

This question in 0971/21 May/June 2019

25 Zinc is extracted from its ore, zinc blende, using two chemical reactions. 1 2ZnS + 3O2 → 2ZnO + 2SO2 2 2ZnO + C → 2Zn + CO2 Which substance is reduced in reactions 1 and 2? reaction 1 reaction 2 A O2 C B O2 ZnO C ZnS C D ZnS ZnO

1 marks

Answer: B

This question in 0971/21 May/June 2019

29 Which statement about the extraction of aluminium from aluminium oxide is correct? A Aluminium is formed at the positive electrode during electrolysis. B Pure aluminium oxide is dissolved in molten cryolite. C Pure aluminium oxide is electrolysed using aluminium as the positive electrode. D Pure aluminium oxide is heated with carbon to form carbon dioxide and aluminium.

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2019

27 Molten iron from the blast furnace contains impurities. The process of turning the impure iron into steel involves blowing oxygen into the molten iron and adding calcium oxide. What are the reasons for blowing in oxygen and adding calcium oxide? blowing in oxygen adding calcium oxide A carbon is removed by reacting with oxygen reacts with acidic impurities making slag B carbon is removed by reacting with oxygen reacts with slag and so removes it C iron reacts with the oxygen reacts with acidic impurities making slag D iron reacts with the oxygen reacts with slag and so removes it

1 marks

Answer: A

This question in 0971/21 May/June 2020

26 Many metal carbonates decompose when they are heated. Which row describes what happens when potassium carbonate, calcium carbonate and copper(II) carbonate are heated using a Bunsen burner? decomposes does not decompose at decomposes easily with difficulty Bunsen temperatures A calcium carbonate copper(II) carbonate potassium carbonate B copper(II) carbonate calcium carbonate potassium carbonate C copper(II) carbonate potassium carbonate calcium carbonate D potassium carbonate calcium carbonate copper(II) carbonate

1 marks

Answer: B

This question in 0971/22 May/June 2020

27 Molten iron from the blast furnace contains impurities. The process of turning the impure iron into steel involves blowing oxygen into the molten iron and adding calcium oxide. What are the reasons for blowing in oxygen and adding calcium oxide? blowing in oxygen adding calcium oxide A carbon is removed by reacting with oxygen reacts with acidic impurities making slag B carbon is removed by reacting with oxygen reacts with slag and so removes it C iron reacts with the oxygen reacts with acidic impurities making slag D iron reacts with the oxygen reacts with slag and so removes it

1 marks

Answer: A

This question in 0971/22 May/June 2020

31 The apparatus used for the extraction of aluminium oxide by electrolysis is shown. carbon anodes – + carbon lining solution of as cathode aluminium oxide in molten cryolite molten aluminium collects at the bottom Which equation represents a reaction taking place at the anode? A O + 2e–  O2– B 2O2–  O2 + 4e– C Al 3–  Al + 3e– D Al 3+ + 3e–  Al

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2020

26 Some metal nitrates and carbonates decompose when heated strongly. Metal Q has a nitrate that decomposes to give a salt and a colourless gas only. The carbonate of metal Q does not decompose when heated with a Bunsen burner. What is metal Q? A calcium B copper C sodium D zinc

1 marks

Answer: C

This question in 0971/21 May/June 2021

27 Which substances are used in the extraction of aluminium? A bauxite and cryolite B bauxite and hematite C cryolite and zinc blende D hematite and zinc blende

1 marks

Answer: A

This question in 0971/21 May/June 2021

26 Some metal nitrates and carbonates decompose when heated strongly. Metal Q has a nitrate that decomposes to give a salt and a colourless gas only. The carbonate of metal Q does not decompose when heated with a Bunsen burner. What is metal Q? A calcium B copper C sodium D zinc

1 marks

Answer: C

This question in 0971/22 May/June 2021

27 Aluminium is extracted from its ore by electrolysis. Which equation represents the reaction that occurs at the anode during the electrolysis? A Al 3+ + 3e–  Al B Al 3+  Al + 3e– C 2O2–  O2 + 4e– D 2O2– + 2e–  O2

1 marks

Answer: C

This question in 0971/22 May/June 2021

33 The equations represent two reactions, P and Q, of lime (calcium oxide). P CaO + SiO2  CaSiO3 Q CaO + SO2  CaSO3 In which processes do the reactions occur? P Q A extraction of iron extraction of iron B extraction of iron flue gas desulfurisation C flue gas desulfurisation extraction of iron D flue gas desulfurisation flue gas desulfurisation

1 marks

Answer: B

This question in 0971/22 May/June 2021

26 Carbon dioxide is produced during the extraction of aluminium from bauxite. Which statement describes how this carbon dioxide is made? A Carbon monoxide reduces aluminium oxide forming carbon dioxide and aluminium. B Carbon is burned in the blast furnace to release heat energy. C Oxygen made in the process reacts with the carbon electrode. D The ore of aluminium undergoes thermal decomposition.

1 marks

Answer: C

This question in 0971/22 Oct/Nov 2021

31 Which reaction involving sulfur dioxide is correct? A It is produced during the extraction of zinc from zinc blende. B It reacts with concentrated sulfuric acid to form oleum. C It reacts with sulfur to form sulfur trioxide. D It turns an acidified solution of potassium manganate(VII) purple.

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2021

23 In the extraction of aluminium by electrolysis, cryolite is added to the bauxite ore. Which row describes the role of cryolite and gives the ionic half-equation at the cathode? role of cryolite ionic half-equation at the cathode A catalyst Al 3+ + 3e–  Al B catalyst Al 3+ + 3e–  3Al C lowers melting point of electrolyte Al 3+ + 3e–  Al D lowers melting point of electrolyte Al 3+ + 3e–  3Al

1 marks

Answer: C

This question in 0971/21 May/June 2022

29 Processes involved in the extraction of zinc are listed. 1 Heat zinc oxide with carbon. 2 Condense zinc vapour. 3 Vaporise the zinc. 4 Roast zinc ore in air. In which order are the processes carried out? A 1  2  3  4 B 4  3  1  2 C 4  1  3  2 D 1  4  3  2

1 marks

Answer: C

This question in 0971/22 May/June 2022

28 During the electrolysis of aluminium oxide, the mass of the carbon anode changes. Which row describes the change and gives a reason for this change? mass change reason of the anode A decreases carbon reacts to form carbon dioxide B decreases carbon dissolves in molten cryolite C increases electrodes become coated with cryolite D increases electrodes become coated with aluminium

1 marks

Answer: A

This question in 0971/21 May/June 2023

28 Why is cryolite used in the extraction of aluminium by electrolysis? A It dissolves the aluminium oxide. B It protects the anodes from corrosion. C It changes bauxite to aluminium oxide. D It decreases the melting point of the aluminium.

1 marks

Answer: A

This question in 0971/22 May/June 2023

17 In a blast furnace, iron(III) oxide is converted to iron and carbon monoxide is converted to carbon dioxide. Fe2O3 + 3CO  2Fe + 3CO2 What happens to each of these reactants? A Both iron(III) oxide and carbon monoxide are oxidised. B Both iron(III) oxide and carbon monoxide are reduced. C Iron(III) oxide is oxidised and carbon monoxide is reduced. D Iron(III) oxide is reduced and carbon monoxide is oxidised.

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2023

29 Why is limestone added to the blast furnace? A It neutralises the molten slag produced. B It reacts with impurities to form slag. C It releases carbon dioxide which reduces the iron(III) oxide. D It removes acidic gases such as carbon dioxide.

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2023

26 Which equation represents the reduction of a compound found in hematite in the blast furnace? A 2Al 2O3 →4Al + 3O2 B CaO + SiO2 →CaSiO3 C 2FeO + CO →Fe2O3 + C D Fe2O3 + 3CO →2Fe + 3CO2

1 marks

Answer: D

This question in 0971/22 May/June 2024

26 Aluminium is extracted from its ore by electrolysis. What is the role of cryolite in this process? A to lower the operating temperature B to lower the boiling point of bauxite C to raise the melting point of bauxite D to act as a catalyst

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2024

28 Which equation represents a reaction that occurs in a blast furnace during the extraction of iron from hematite? A Ca + CO2  CaO + CO B Fe2O3 + 3Ca  2Fe + 3CaO C Ca(OH)2  CaO + H2O D Fe2O3 + 3CO  2Fe + 3CO2

1 marks

Answer: D

This question in 0971/22 May/June 2025

28 Iron is extracted from hematite in the blast furnace. Which reaction increases the temperature in the blast furnace to over 1500 °C? A calcium carbonate  calcium oxide + carbon dioxide B calcium oxide + silicon(IV) oxide  calcium silicate C carbon + oxygen  carbon dioxide D carbon dioxide + carbon  carbon monoxide

1 marks

Answer: C

This question in 0971/22 Oct/Nov 2025

29 Aluminium is extracted by the electrolysis of purified bauxite. Which row shows the half-equations at the electrodes and explains why one of the electrodes has to be replaced regularly? half-equation half-equation electrode at anode at cathode replacement A 2O2–  O2 + 4e– Al 3+ + 3e–  Al cathode replaced as it gets coated with aluminium B 2O2–  O2 + 4e– Al 3+ + 3e–  Al anode replaced as it burns away in oxygen C Al 3+ + 3e–  Al 2O2–  O2 + 4e– cathode replaced as it burns away in oxygen D Al 3+ + 3e–  Al 2O2–  O2 + 4e– anode replaced as it gets coated with aluminium

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2025