Electrolysis — Paper 2 · IGCSE Science - Combined 0653

17 Molten sodium chloride can be electrolysed. Which row describes what happens at each electrode? anode cathode A chloride ions gain electrons sodium ions lose electrons B chloride ions lose electrons sodium ions gain electrons C sodium ions gain electrons chloride ions lose electrons D sodium ions lose electrons chloride ions gain electrons

1 marks

Answer: B

This question in 0653/22 Feb/March 2017

18 Molten sodium chloride is electrolysed. Which equations represent the reactions at the electrodes? anode cathode A 2Cl – → Cl 2 + 2e– Na+ + e– → Na B Cl 2 + 2e– → 2Cl – Na → Na+ + e– C Na → Na+ + e– Cl 2 + 2e– → 2Cl – D Na+ + e– → Na 2Cl – → Cl 2 + 2e–

1 marks

Answer: A

This question in 0653/21 May/June 2017

18 Aqueous copper chloride is electrolysed using inert electrodes. Which row describes what happens at each electrode? cathode anode A chloride ions gain copper ions lose electrons to form chlorine electrons to form copper B chloride ions lose copper ions gain electrons to form chlorine electrons to form copper C copper ions gain chloride ions lose electrons to form copper electrons to form chlorine D copper ions lose chloride ions gain electrons to form copper electrons to form chlorine

1 marks

Answer: C

This question in 0653/22 May/June 2017

18 Molten sodium chloride is electrolysed. What are the electrode products? at the anode at the cathode A chlorine hydrogen B chlorine sodium C hydrogen chlorine D sodium chlorine

1 marks

Answer: B

This question in 0653/23 May/June 2017

19 What is produced at the anode during the electrolysis of molten lead(II) bromide? A bromide ions B bromine C lead D lead(II) ions

1 marks

Answer: B

This question in 0653/21 Oct/Nov 2017

19 What is formed at the cathode during the electrolysis of aqueous copper chloride? A chlorine B copper C hydrogen D oxygen

1 marks

Answer: B

This question in 0653/22 Oct/Nov 2017

18 Which equation represents the reaction at the cathode during the electrolysis of aqueous copper(II) chloride? A 2Cl – → Cl 2 + 2e− B Cu2+ + 2e− → Cu C 2H+ + 2e− → H2 D 4OH– → O2 + 2H2O + 4e−

1 marks

Answer: B

This question in 0653/22 Feb/March 2018

18 The diagram shows apparatus for electrolysis. Only one label is correct. electrode + – cathode anode electrolyte Which label on the diagram is correct? A anode B cathode C electrode D electrolyte

1 marks

Answer: D

This question in 0653/21 May/June 2018

19 Molten sodium chloride is electrolysed. Which row shows the product and the equation for the reaction at the stated electrode? equation for reaction electrode product at the electrode A negative chlorine 2Cl – → Cl 2 + 2e– B negative sodium Na+ + e– → Na C positive chlorine 2Cl 2– → Cl 2 + 4e– D positive sodium Na+ + 2e– → Na

1 marks

Answer: B

This question in 0653/21 May/June 2018

18 The diagram shows apparatus for electrolysis. Only one label is correct. electrode + – cathode anode electrolyte Which label on the diagram is correct? A anode B cathode C electrode D electrolyte

1 marks

Answer: D

This question in 0653/22 May/June 2018

19 When aqueous copper chloride is electrolysed, ions move to the electrodes. Which ions move to the positive electrode? A chloride B copper C hydrogen D oxide

1 marks

Answer: A

This question in 0653/22 May/June 2018

18 The diagram shows apparatus for electrolysis. Only one label is correct. electrode + – cathode anode electrolyte Which label on the diagram is correct? A anode B cathode C electrode D electrolyte

1 marks

Answer: D

This question in 0653/23 May/June 2018

19 Molten calcium chloride is electrolysed. What happens at the negative electrode? A Calcium atoms lose electrons to form calcium ions. B Calcium ions gain electrons to form calcium atoms. C Chloride ions lose electrons to form chlorine molecules. D Chlorine molecules gain electrons to form chloride ions.

1 marks

Answer: B

This question in 0653/23 May/June 2018

18 Some chemical compounds are broken down by electrolysis using inert electrodes. Which row identifies the electrode products for the stated electrolyte? electrolyte product at anode product at cathode A aqueous copper chloride hydrogen copper B molten aluminium oxide aluminium oxygen C molten copper chloride chlorine copper D molten potassium bromide potassium bromine

1 marks

Answer: C

This question in 0653/21 Oct/Nov 2018

18 During the electrolysis of aqueous copper chloride, ions move. A gas is produced at one of the electrodes. Which diagram shows the movement of ions and the electrode at which the gas is produced? A B power supply power supply – + – + gas bubbles gas bubbles anions anions cations cations C D power supply power supply – + – + gas bubbles gas bubbles anions anions cations cations

1 marks

Answer: B

This question in 0653/22 Oct/Nov 2018

18 During the electrolysis of molten potassium chloride, which particles in the electrolyte move towards the cathode? A electrons B chloride ions C chlorine molecules D potassium ions

1 marks

Answer: D

This question in 0653/23 Oct/Nov 2018

17 Which statement about the electrolysis of molten lead(II) bromide is correct? A Bromide ions gain electrons to form bromine at the cathode. B Bromine loses electrons to form bromide ions at the anode. C Lead atoms lose electrons to form lead ions at the anode. D Lead ions accept electrons to form lead at the cathode.

1 marks

Answer: D

This question in 0653/22 Feb/March 2019

17 Which process occurs at the anode during the electrolysis of concentrated aqueous sodium chloride? A Chloride ions lose electrons to form chlorine. B Hydrogen ions gain electrons to form hydrogen. C Oxide ions lose electrons to form oxygen. D Sodium ions gain electrons to form sodium.

1 marks

Answer: A

This question in 0653/21 May/June 2019

18 Which statement about the electrolysis of molten magnesium chloride is correct? A Cations form atoms by losing electrons. B Chlorine atoms gain electrons to form chloride ions. C Magnesium ions gain electrons to form magnesium atoms. D Magnesium is produced at the anode and chlorine is formed at the cathode.

1 marks

Answer: C

This question in 0653/22 May/June 2019

17 Molten sodium chloride is electrolysed. What are the products at the electrodes? product at anode product at cathode A chlorine hydrogen B chlorine sodium C hydrogen chlorine D sodium chlorine

1 marks

Answer: B

This question in 0653/23 May/June 2019

18 Element X is a non-metal used in the treatment of the water supply. It is made during the electrolysis of a metal salt. What is the colour of X and at which electrode is it made? colour electrode A red anode B red cathode C yellow-green anode D yellow-green cathode

1 marks

Answer: C

This question in 0653/21 Oct/Nov 2019

17 Element X is a non-metal used in the treatment of the water supply. It is made during the electrolysis of a metal salt. What is the colour of X and at which electrode is it made? colour electrode A red anode B red cathode C yellow-green anode D yellow-green cathode

1 marks

Answer: C

This question in 0653/22 Oct/Nov 2019

17 Element X is a non-metal used in the treatment of the water supply. It is made during the electrolysis of a metal salt. What is the colour of X and at which electrode is it made? colour electrode A red anode B red cathode C yellow-green anode D yellow-green cathode

1 marks

Answer: C

This question in 0653/23 Oct/Nov 2019

18 Molten silver chloride is electrolysed using inert electrodes. anode cathode molten silver chloride The cathode attracts … 1 … in the electrolyte where they are … 2 … . Which words complete the gaps? 1 2 A chloride ions oxidised B chloride ions reduced C silver ions reduced D silver ions oxidised

1 marks

Answer: C

This question in 0653/21 May/June 2020

18 Which statement about the electrolysis of a molten metal halide is correct? A Cations move to the anode. B Electrons flow through the electrolyte. C Ions gain protons at the cathode. D Ions lose electrons at the anode.

1 marks

Answer: D

This question in 0653/21 Oct/Nov 2020

18 Which statement describes the movement of electrons during electrolysis? A They move from the anode to the cathode through the external circuit. B They move from the anode to the cathode through the electrolyte. C They move from the cathode to the anode through the external circuit. D They move from the cathode to the anode through the electrolyte.

1 marks

Answer: A

This question in 0653/22 Oct/Nov 2020

18 What happens to cations during electrolysis? A They gain electrons. B They gain oxygen. C They lose electrons. D They lose oxygen.

1 marks

Answer: A

This question in 0653/23 Oct/Nov 2020

18 Which process occurs during electrolysis? A Anions gain electrons at the anode. B Anions lose electrons at the anode. C Cations gain electrons at the anode. D Cations lose electrons at the cathode.

1 marks

Answer: B

This question in 0653/22 Feb/March 2021

18 Two substances are electrolysed separately using inert electrodes. Which two substances form the same product at one of the electrodes? A molten sodium bromide and concentrated aqueous sodium chloride B molten sodium bromide and dilute sulfuric acid C molten aluminium oxide and concentrated aqueous sodium chloride D molten aluminium oxide and dilute sulfuric acid

1 marks

Answer: D

This question in 0653/21 May/June 2021

17 Which products are formed when molten sodium chloride is electrolysed using inert electrodes? at the anode at the cathode A chlorine hydrogen B chlorine sodium C oxygen hydrogen D oxygen sodium

1 marks

Answer: B

This question in 0653/22 May/June 2021

18 What happens at the anode during the electrolysis of molten aluminium oxide? A Aluminium ions gain electrons to form aluminium atoms. B Aluminium ions lose electrons to form aluminium atoms. C Oxide ions gain electrons to form oxygen molecules. D Oxide ions lose electrons to form oxygen molecules.

1 marks

Answer: D

This question in 0653/22 Feb/March 2022

16 Which statement about the electrolysis of molten lead(II) bromide using carbon electrodes is correct? A Bromide ions gain electrons at the anode. B Bromide ions lose electrons at the anode. C Lead ions gain electrons at the anode. D Lead ions lose electrons at the anode.

1 marks

Answer: B

This question in 0653/22 May/June 2022

16 Which statement about the movement of particles during the electrolysis of dilute sulfuric acid is correct? A Anions move to the negative electrode and lose electrons. B Electrons travel through the electrolyte from the cathode to the anode. C Electrons travel through the external circuit from the anode to the cathode. D Positive ions move to the anode and gain electrons.

1 marks

Answer: C

This question in 0653/23 May/June 2022

17 Concentrated aqueous sodium chloride is electrolysed using inert electrodes. Which statement is correct? A Chloride ions lose electrons at the cathode. B Hydrogen ions gain electrons at the cathode. C Oxide ions gain electrons at the anode. D Sodium ions gain electrons at the cathode.

1 marks

Answer: B

This question in 0653/21 Oct/Nov 2022

17 Which equation represents the process that occurs at the cathode during the electrolysis of concentrated aqueous sodium chloride? A 2O2–  O2 + 4e– B 2Cl –  Cl 2 + 2e– C Na+ + e–  Na D 2H+ + 2e–  H2

1 marks

Answer: D

This question in 0653/22 Oct/Nov 2022

16 The diagram shows an experiment to electrolyse dilute sulfuric acid. negative positive electrode electrode Which statement explains why bubbles form at the positive electrode? A Oxide ions lose electrons to form oxygen. B Hydroxide ions lose electrons to form hydrogen. C Hydroxide ions lose electrons to form oxygen and water. D Hydrogen ions gain electrons to form hydrogen.

1 marks

Answer: C

This question in 0653/22 Feb/March 2023

18 Which statement about the electrolysis of molten lead(II) bromide is correct? A Lead anions move to the anode where they gain electrons. B Lead anions move to the cathode where they lose electrons. C Lead cations move to the anode where they lose electrons. D Lead cations move to the cathode where they gain electrons.

1 marks

Answer: D

This question in 0653/21 May/June 2023

18 Which statement about the electrolysis of ionic substances is correct? A Negatively charged ions move to the cathode. B At the anode, ions lose electrons. C The anions gain electrons during electrolysis. D The cations are negatively charged.

1 marks

Answer: B

This question in 0653/22 May/June 2023

18 Dilute sulfuric acid is electrolysed using inert electrodes. The concentration of two ions decreases during this process. What are these ions? A hydrogen ions and oxide ions B hydrogen ions and hydroxide ions C hydroxide ions and sulfate ions D oxide ions and sulfate ions

1 marks

Answer: B

This question in 0653/23 May/June 2023

18 During electrolysis, positive ions are changed. Which row describes what happens to the positive ions and identifies the electrode where this happens? what happens to electrode the positive ions A gain electrons anode B gain electrons cathode C lose electrons anode D lose electrons cathode

1 marks

Answer: B

This question in 0653/21 Oct/Nov 2023

18 Which statement about the electrolysis of a molten metal halide is correct? A Cations move to the anode. B Electrons flow through the electrolyte. C Ions gain protons at the cathode. D Ions lose electrons at the anode.

1 marks

Answer: D

This question in 0653/22 Feb/March 2024

18 Which rows identify the electrode products for the named electrolyte? product product electrolyte at anode at cathode 1 dilute sulfuric acid oxygen hydrogen 2 dilute sulfuric acid sulfur dioxide hydrogen 3 concentrated aqueous sodium chloride chlorine hydrogen 4 molten lead(II) bromide lead bromine A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: A

This question in 0653/21 May/June 2024

18 Dilute sulfuric acid is electrolysed using platinum electrodes. Which statements about this electrolysis are correct? 1 Water is broken down to give hydrogen and oxygen. 2 Water is covalent but the solution conducts electricity because it contains equal concentrations of H+ ions and OH– ions. 3 The equation for the reaction at the anode is 4OH–  2H2O + O2 + 4e–. 4 The equation for the reaction at the cathode is 2H+  H2 + 2e–. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: A

This question in 0653/22 May/June 2024

19 Concentrated aqueous sodium chloride is electrolysed using platinum electrodes. Which statements are correct? 1 The equation for the reaction at the cathode is Na+(aq) + e–  Na(s). 2 The equation for the reaction at the anode is 2Cl –(aq)  Cl 2(g) + 2e–. 3 At the positive electrode, hydroxide ions from water form oxygen. 4 At the negative electrode, hydrogen ions from water form hydrogen. A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: C

This question in 0653/23 May/June 2024

18 When molten sodium chloride is electrolysed using inert electrodes, sodium and chlorine are produced at the electrodes. Which row describes what happens at the anode and at the cathode? at the anode at the cathode A chloride ions gain electrons sodium ions lose electrons B chloride ions lose electrons sodium ions gain electrons C sodium ions lose electrons chloride ions gain electrons D sodium ions gain electrons chloride ions lose electrons

1 marks

Answer: B

This question in 0653/21 Oct/Nov 2024

18 Molten silver chloride is electrolysed using inert electrodes. Which statement about this electrolysis is correct? A Silver ions gain electrons at the anode. B Silver ions gain electrons at the cathode. C Silver ions lose electrons at the anode. D Silver ions lose electrons at the cathode.

1 marks

Answer: B

This question in 0653/23 Oct/Nov 2024

19 Which row shows what forms at the electrodes during electrolysis of an aqueous compound? anode cathode A metal non-metal B non-metal metal C hydrogen metal D hydrogen oxygen

1 marks

Answer: B

This question in 0653/21 May/June 2025

27 Which row shows an electrolyte and the products of electrolysis for this electrolyte? electrolyte products A concentrated aqueous sodium chloride sodium and chlorine B molten potassium bromide hydrogen and bromine C molten sodium chloride sodium and chlorine D dilute sulfuric acid hydrogen and sulfur dioxide

1 marks

Answer: C

This question in 0653/22 May/June 2025

17 Apparatus used to electrolyse molten lead(II) bromide is shown. d.c. power supply + – P Q Which row identifies P and Q? P Q A cathode electrolyte B anode electrode C anode electrolyte D cathode electrode

1 marks

Answer: A

This question in 0653/23 May/June 2025

27 An electric current is passed through molten calcium chloride using graphite electrodes. Which row shows the electrode products? anode product cathode product A calcium chlorine B chlorine calcium C chlorine hydrogen D hydrogen chlorine

1 marks

Answer: B

This question in 0653/21 Oct/Nov 2025