Skip to content
Try on iPad

Electrolysis: AQA GCSE Combined Science questions

Every AQA GCSE Combined Science exam question on 5.4.3 Electrolysis, 2018–2025, with its mark scheme and examiner’s report.

Find questions3,069
Calculations

3,069 questions

  1. Q01.1

    June 2025 · Chemistry Paper 1 Higher

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Higher, question 01.1: Chlorine gas is given off during the electrolysis of copper chloride solution. Chlorine gas is poisonous. Give one way of reducing the risk of harm. [1 mark] Ta

  2. Q01.2

    June 2025 · Chemistry Paper 1 Higher

    3 marks5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Higher, question 01.2: Plot the data from Table 1 on Figure 2. Draw a line of best fit. The first point has been plotted for you. [3 marks] Figure 2

  3. Q01.3

    June 2025 · Chemistry Paper 1 Higher

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Higher, question 01.3: A student made the hypothesis: ‘The negative electrode will increase by a constant mass every 60 seconds.’ How do the results in Table 1 show that the hypothesi

  4. Q01.5

    June 2025 · Chemistry Paper 1 Higher

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Higher, question 01.5: The teacher also electrolysed potassium chloride solution. Hydrogen gas was given off at the negative electrode. Why was hydrogen gas given off? [1 mark] Tick (

  5. Q04.2

    June 2025 · Chemistry Paper 1 Higher

    2 marks5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Higher, question 04.2: Explain why a mixture of aluminium oxide and cryolite is used as the electrolyte instead of only aluminium oxide. [2 marks]

  6. Q04.3

    June 2025 · Chemistry Paper 1 Higher

    2 marks5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Higher, question 04.3: Oxygen gas is produced at the positive electrode. Write a balanced half equation for the production of oxygen at the positive electrode. [2 marks] → +

  7. Q04.5

    June 2025 · Chemistry Paper 1 Higher

    1 mark5.4.1 Reactivity of metals5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Higher, question 04.5: Give one reason for the difference in the cost of extracting aluminium and iron. Use Table 3. [1 mark]

  8. Q04.6

    June 2025 · Chemistry Paper 1 Higher

    1 mark5.4.1 Reactivity of metals5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Higher, question 04.6: Give one reason for the difference in the cost of extracting aluminium and chromium. Use Table 3. [1 mark]

  9. Q04.3

    June 2025 · Chemistry Paper 1 Foundation

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Foundation, question 04.3: The mixture of aluminium oxide and cryolite has a lower melting point than aluminium oxide alone. Why is the melting point lowered? [1 mark] Tick () one box. T

  10. Q04.4

    June 2025 · Chemistry Paper 1 Foundation

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Foundation, question 04.4: After some time, the positive electrodes need to be replaced. Why must the positive electrodes be replaced? [1 mark] Tick () one box. The electrodes dissolve i

  11. Q06.1

    June 2025 · Chemistry Paper 1 Foundation

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Foundation, question 06.1: Chlorine gas is given off during the electrolysis of copper chloride solution. Chlorine gas is poisonous. Give one way of reducing the risk of harm. [1 mark] Ta

  12. Q06.2

    June 2025 · Chemistry Paper 1 Foundation

    3 marks5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Foundation, question 06.2: Plot the data from Table 5 on Figure 13. Draw a line of best fit. The first point has been plotted for you. [3 marks] Figure 13

  13. Q06.3

    June 2025 · Chemistry Paper 1 Foundation

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Foundation, question 06.3: A student made the hypothesis: ‘The negative electrode will increase by a constant mass every 60 seconds.’ How do the results in Table 5 show that the hypothesi

  14. Q06.5

    June 2025 · Chemistry Paper 1 Foundation

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2025 Chemistry Paper 1 Foundation, question 06.5: The teacher also electrolysed potassium chloride solution. Hydrogen gas was given off at the negative electrode. Why was hydrogen gas given off? [1 mark] Tick (

  15. Q06.3

    June 2024 · Chemistry Paper 1 Higher

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2024 Chemistry Paper 1 Higher, question 06.3: Name substance X shown in Figure 10. [1 mark]

  16. Q06.4

    June 2024 · Chemistry Paper 1 Higher

    3 marks5.4.3 Electrolysis
    The whole paper ↗
    June 2024 Chemistry Paper 1 Higher, question 06.4: Explain what happens to the positive carbon electrodes during the extraction of aluminium from aluminium oxide. [3 marks]

  17. Q06.5

    June 2024 · Chemistry Paper 1 Higher

    2 marks5.4.3 Electrolysis
    The whole paper ↗
    June 2024 Chemistry Paper 1 Higher, question 06.5: The formula of aluminium oxide is Al2O3 Write a half equation for the reaction at the negative electrode in Figure 10. [2 marks] + →

  18. Q05.3

    June 2024 · Chemistry Paper 1 Foundation

    2 marks5.4.3 Electrolysis
    The whole paper ↗
    June 2024 Chemistry Paper 1 Foundation, question 05.3: Magnesium chloride contains Mg2+ ions and Cl– ions. Name the product at each electrode when molten magnesium chloride is electrolysed. [2 marks] Negative electr

  19. Q05.1

    June 2023 · Chemistry Paper 1 Higher

    1 mark5.2.2 How bonding and structure are related to the properties of substances5.4.3 Electrolysis
    The whole paper ↗
    June 2023 Chemistry Paper 1 Higher, question 05.1: Why does solid sodium chloride not conduct electricity? [1 mark]

  20. Q05.2

    June 2023 · Chemistry Paper 1 Higher

    1 mark5.4.3 Electrolysis
    The whole paper ↗
    June 2023 Chemistry Paper 1 Higher, question 05.2: Sodium chloride solution conducts electricity. Complete the sentence. [1 mark] Sodium chloride also conducts electricity when .
All 71 questions on Electrolysis, as a list
  1. June 2025, Chemistry Paper 1 Higher, Q01.1 (1 mark): Chlorine gas is given off during the electrolysis of copper chloride solution. Chlorine gas is poisonous. Give one way of reducing the risk of harm. [1 mark] Ta
  2. June 2025, Chemistry Paper 1 Higher, Q01.2 (3 marks): Plot the data from Table 1 on Figure 2. Draw a line of best fit. The first point has been plotted for you. [3 marks] Figure 2
  3. June 2025, Chemistry Paper 1 Higher, Q01.3 (1 mark): A student made the hypothesis: ‘The negative electrode will increase by a constant mass every 60 seconds.’ How do the results in Table 1 show that the hypothesi
  4. June 2025, Chemistry Paper 1 Higher, Q01.5 (1 mark): The teacher also electrolysed potassium chloride solution. Hydrogen gas was given off at the negative electrode. Why was hydrogen gas given off? [1 mark] Tick (
  5. June 2025, Chemistry Paper 1 Higher, Q04.2 (2 marks): Explain why a mixture of aluminium oxide and cryolite is used as the electrolyte instead of only aluminium oxide. [2 marks]
  6. June 2025, Chemistry Paper 1 Higher, Q04.3 (2 marks): Oxygen gas is produced at the positive electrode. Write a balanced half equation for the production of oxygen at the positive electrode. [2 marks] → +
  7. June 2025, Chemistry Paper 1 Higher, Q04.5 (1 mark): Give one reason for the difference in the cost of extracting aluminium and iron. Use Table 3. [1 mark]
  8. June 2025, Chemistry Paper 1 Higher, Q04.6 (1 mark): Give one reason for the difference in the cost of extracting aluminium and chromium. Use Table 3. [1 mark]
  9. June 2025, Chemistry Paper 1 Foundation, Q04.3 (1 mark): The mixture of aluminium oxide and cryolite has a lower melting point than aluminium oxide alone. Why is the melting point lowered? [1 mark] Tick () one box. T
  10. June 2025, Chemistry Paper 1 Foundation, Q04.4 (1 mark): After some time, the positive electrodes need to be replaced. Why must the positive electrodes be replaced? [1 mark] Tick () one box. The electrodes dissolve i
  11. June 2025, Chemistry Paper 1 Foundation, Q06.1 (1 mark): Chlorine gas is given off during the electrolysis of copper chloride solution. Chlorine gas is poisonous. Give one way of reducing the risk of harm. [1 mark] Ta
  12. June 2025, Chemistry Paper 1 Foundation, Q06.2 (3 marks): Plot the data from Table 5 on Figure 13. Draw a line of best fit. The first point has been plotted for you. [3 marks] Figure 13
  13. June 2025, Chemistry Paper 1 Foundation, Q06.3 (1 mark): A student made the hypothesis: ‘The negative electrode will increase by a constant mass every 60 seconds.’ How do the results in Table 5 show that the hypothesi
  14. June 2025, Chemistry Paper 1 Foundation, Q06.5 (1 mark): The teacher also electrolysed potassium chloride solution. Hydrogen gas was given off at the negative electrode. Why was hydrogen gas given off? [1 mark] Tick (
  15. June 2024, Chemistry Paper 1 Higher, Q06.3 (1 mark): Name substance X shown in Figure 10. [1 mark]
  16. June 2024, Chemistry Paper 1 Higher, Q06.4 (3 marks): Explain what happens to the positive carbon electrodes during the extraction of aluminium from aluminium oxide. [3 marks]
  17. June 2024, Chemistry Paper 1 Higher, Q06.5 (2 marks): The formula of aluminium oxide is Al2O3 Write a half equation for the reaction at the negative electrode in Figure 10. [2 marks] + →
  18. June 2024, Chemistry Paper 1 Foundation, Q05.3 (2 marks): Magnesium chloride contains Mg2+ ions and Cl– ions. Name the product at each electrode when molten magnesium chloride is electrolysed. [2 marks] Negative electr
  19. June 2023, Chemistry Paper 1 Higher, Q05.1 (1 mark): Why does solid sodium chloride not conduct electricity? [1 mark]
  20. June 2023, Chemistry Paper 1 Higher, Q05.2 (1 mark): Sodium chloride solution conducts electricity. Complete the sentence. [1 mark] Sodium chloride also conducts electricity when .
  21. June 2023, Chemistry Paper 1 Higher, Q05.3 (1 mark): Suggest an element that could be used to make the inert electrodes. [1 mark]
  22. June 2023, Chemistry Paper 1 Higher, Q05.4 (2 marks): Complete the half equation for the production of chlorine (Cl2) at the positive electrode. [2 marks] Cl– → +
  23. June 2023, Chemistry Paper 1 Higher, Q05.5 (4 marks): Sodium chloride solution has a pH of 7 During the electrolysis of sodium chloride solution: • hydrogen gas is produced at the negative electrode • the pH of the
  24. June 2023, Chemistry Paper 1 Foundation, Q04.2 (2 marks): Two of these ions are formed when a water molecule breaks down. The symbol equation when a water molecule breaks down is: H2O → H+ + OH– Complete the word equat
  25. June 2023, Chemistry Paper 1 Foundation, Q04.4 (2 marks): Explain why copper ions (Cu2+) move to the negative electrode. [2 marks]
  26. June 2023, Chemistry Paper 1 Foundation, Q04.5 (1 mark): Complete the sentence. Choose the answer from the box. [1 mark] decomposed discharged distilled At the negative electrode copper metal is produced when the copp
  27. June 2023, Chemistry Paper 1 Foundation, Q04.6 (1 mark): What happens to the mass of the negative electrode during electrolysis? [1 mark] Tick () one box. Decreases No change Increases There are four ions in copper b
  28. June 2023, Chemistry Paper 1 Foundation, Q04.7 (1 mark): What is produced at the positive electrode when copper bromide solution is electrolysed? [1 mark] Tick () one box. Bromine Hydrogen Oxygen
  29. June 2023, Chemistry Paper 1 Foundation, Q05.1 (1 mark): Complete the sentence. [1 mark] The extraction of aluminium is expensive because the process uses large amounts of .
  30. June 2023, Chemistry Paper 1 Foundation, Q05.2 (1 mark): Oxygen is produced at the positive carbon electrodes. The oxygen reacts with the carbon electrodes. Which gas is produced when oxygen reacts with the positive c
  31. June 2022, Chemistry Paper 1 Higher, Q02.1 (1 mark): Potassium sulfate contains K+ and SO42– ions. What is the formula of potassium sulfate? [1 mark] Tick () one box. KSO4 K2SO4 K(SO4)2 K2(SO4)2
  32. June 2022, Chemistry Paper 1 Higher, Q02.2 (1 mark): What are the volumes of gases collected in the electrolysis experiment? Use Figure 2. [1 mark] Volume of hydrogen = cm3 Volume of oxygen = cm3
  33. June 2022, Chemistry Paper 1 Higher, Q02.3 (2 marks): A student made the following hypothesis: ‘The volumes of gases collected in this electrolysis experiment are in the same ratio as hydrogen atoms to oxygen atoms
  34. June 2022, Chemistry Paper 1 Higher, Q02.5 (3 marks): The potassium sulfate solution has 0.86 g of potassium sulfate dissolved in 25 cm3 of water. Calculate the mass of potassium sulfate needed to make 1.0 dm3 of s
  35. June 2022, Chemistry Paper 1 Higher, Q07.1 (2 marks): Figure 8 shows a reactivity series. Figure 8 Most reactive Potassium Magnesium Metal Y Carbon Iron Hydrogen Copper Least reactive Give the method and conditions
  36. June 2022, Chemistry Paper 1 Foundation, Q04.5 (2 marks): Figure 10 shows a reactivity series. Figure 10 Most reactive Metal D Sodium Magnesium Carbon Metal E Iron Hydrogen Copper Least reactive Draw one line from each
  37. June 2022, Chemistry Paper 1 Foundation, Q06.1 (1 mark): Potassium sulfate contains K+ and SO42– ions. What is the formula of potassium sulfate? [1 mark] Tick () one box. KSO4 K2SO4 K(SO4)2 K2(SO4)2
  38. June 2022, Chemistry Paper 1 Foundation, Q06.2 (1 mark): What are the volumes of gases collected in the electrolysis experiment? Use Figure 14. [1 mark] Volume of hydrogen = cm3 Volume of oxygen = cm3
  39. June 2022, Chemistry Paper 1 Foundation, Q06.3 (2 marks): A student made the following hypothesis: ‘The volumes of gases collected in this electrolysis experiment are in the same ratio as hydrogen atoms to oxygen atoms
  40. June 2022, Chemistry Paper 1 Foundation, Q06.5 (3 marks): The potassium sulfate solution has 0.86 g of potassium sulfate dissolved in 25 cm3 of water. Calculate the mass of potassium sulfate needed to make 1.0 dm3 of s
  41. November 2021, Chemistry Paper 1 Higher, Q05.1 (2 marks): Hydrogen ions (H+) are attracted to the negative electrode. The half equation for the reaction at the negative electrode is: 2 H+ + 2 e– → H2 What type of react
  42. November 2021, Chemistry Paper 1 Higher, Q05.2 (2 marks): Chloride ions are attracted to the positive electrode. Complete the half equation for the production of chlorine gas (Cl2). [2 marks] Cl– → +
  43. November 2021, Chemistry Paper 1 Higher, Q05.3 (4 marks): Hydrogen gas and oxygen gas are produced when sodium sulfate solution is electrolysed. Explain how oxygen gas is produced in the electrolysis of sodium sulfate
  44. November 2021, Chemistry Paper 1 Foundation, Q02.1 (1 mark): Complete the sentence. Choose the answer from the box. [1 mark] gaseous molten solid Copper chloride can conduct electricity when in solution or when .
  45. November 2021, Chemistry Paper 1 Foundation, Q02.2 (1 mark): Why do Cl– ions and OH– ions move to the positive electrode? [1 mark]
  46. November 2021, Chemistry Paper 1 Foundation, Q02.3 (1 mark): Where do the H+ and OH– ions come from in the electrolysis of copper chloride solution? [1 mark] Tick () one box. Air Copper chloride Water
  47. November 2021, Chemistry Paper 1 Foundation, Q02.4 (1 mark): Which ion produces a metal? [1 mark] Tick () one box. Cu2+ Cl– H+ OH–
  48. November 2021, Chemistry Paper 1 Foundation, Q02.5 (2 marks): Figure 2 shows the apparatus during the electrolysis of copper chloride solution. Figure 2 Describe what is seen at each electrode during the electrolysis of co
  49. November 2021, Chemistry Paper 1 Foundation, Q05.2 (1 mark): Figure 8 shows part of the measuring cylinder. Figure 8 What is the volume of copper sulfate solution in Figure 8? [1 mark] Volume = cm3
  50. November 2021, Chemistry Paper 1 Foundation, Q05.4 (4 marks): Determine the gradient of the line in Figure 10. Use the equation: gradient = increase in temperature in °C increase in mass in grams [4 marks] Gradient = °C pe
  51. November 2021, Chemistry Paper 1 Foundation, Q05.5 (2 marks): Suggest why the student should not use more than 10 g of zinc. Use Figure 10. You should extend the graph line. [2 marks]
  52. November 2020, Chemistry Paper 1 Higher, Q01.3 (3 marks): Oxygen is formed at the positive carbon electrodes. Explain why the positive carbon electrodes must be continually replaced. [3 marks]
  53. November 2020, Chemistry Paper 1 Foundation, Q06.3 (3 marks): Oxygen is formed at the positive carbon electrodes. Explain why the positive carbon electrodes must be continually replaced. [3 marks]
  54. June 2019, Chemistry Paper 1 Higher, Q05.1 (1 mark): Some metals are extracted from molten compounds using electrolysis. Why is electrolysis used to extract some metals? [1 mark]
  55. June 2019, Chemistry Paper 1 Higher, Q05.2 (2 marks): Aluminium is produced by electrolysis of a molten mixture. What two substances does the molten mixture contain? [2 marks] 1 2
  56. June 2019, Chemistry Paper 1 Higher, Q05.3 (2 marks): Copper and chlorine are produced when molten copper chloride is electrolysed. Complete the half equation for the reaction at each electrode. [2 marks] Half equa
  57. June 2019, Chemistry Paper 1 Higher, Q05.4 (2 marks): Suggest two reasons why the mass deposited was different from the expected value. [2 marks] 1 2
  58. June 2019, Chemistry Paper 1 Higher, Q05.5 (3 marks): Figure 5 shows the expected mass of copper produced each minute. Figure 5 Determine the expected mass of copper after 24 hours. Use Figure 5. [3 marks] Mass = m
  59. June 2019, Chemistry Paper 1 Higher, Q05.6 (1 mark): Determine the mass of the negative electrode at the start of the experiment. Use Figure 6. [1 mark]
  60. June 2019, Chemistry Paper 1 Higher, Q05.7 (3 marks): Calculate the gradient of the line in Figure 6. Give the unit. [3 marks] Gradient Unit
  61. June 2019, Chemistry Paper 1 Foundation, Q02.4 (2 marks): Molten copper chloride can be electrolysed. State the product at each electrode when molten copper chloride is electrolysed. [2 marks] Negative electrode Positi
  62. June 2019, Chemistry Paper 1 Foundation, Q02.5 (3 marks): A solution of copper chloride is electrolysed. Figure 3 shows a graph of the increase in mass of the negative electrode. This increase is shown over a time of 1
  63. June 2019, Chemistry Paper 1 Foundation, Q02.6 (2 marks): Aluminium is produced by electrolysis of a molten mixture. Complete the sentence. Choose the answers from the box. [2 marks] carbon chloride cryolite oxide sulf
  64. June 2018, Chemistry Paper 1 Higher, Q01.1 (1 mark): Which gas is produced at the positive electrode (anode)? [1 mark] Tick one box. carbon dioxide chlorine hydrogen oxygen
  65. June 2018, Chemistry Paper 1 Higher, Q01.2 (1 mark): Copper is produced at the negative electrode (cathode). What does this tell you about the reactivity of copper? [1 mark] Tick one box. Copper is less reactive t
  66. June 2018, Chemistry Paper 1 Higher, Q01.3 (1 mark): Determine the mean mass of copper produced after 3 minutes. [1 mark] Mass = mg
  67. June 2018, Chemistry Paper 1 Higher, Q01.4 (2 marks): Calculate the mass X of copper produced in Experiment 2 after 5 minutes. Use Table 1 on page 3 [2 marks] Mass X = mg
  68. June 2018, Chemistry Paper 1 Foundation, Q05.1 (1 mark): Which gas is produced at the positive electrode (anode)? [1 mark] Tick one box. carbon dioxide chlorine hydrogen oxygen
  69. June 2018, Chemistry Paper 1 Foundation, Q05.2 (1 mark): Copper is produced at the negative electrode (cathode). What does this tell you about the reactivity of copper? [1 mark] Tick one box. Copper is less reactive t
  70. June 2018, Chemistry Paper 1 Foundation, Q05.3 (1 mark): Determine the mean mass of copper produced after 3 minutes. [1 mark] Mass = mg
  71. June 2018, Chemistry Paper 1 Foundation, Q05.4 (2 marks): Calculate the mass X of copper produced in Experiment 2 after 5 minutes. Use Table 4 on page 19 [2 marks] Mass X = mg

Questions, mark schemes and examiner’s reports are © AQA, from their published past papers. Plumi isn’t affiliated with any exam board. Want whole papers? Full past papers.

Rather write your answers by hand on iPad? Plumi marks them against the same mark schemes.