plumiElectrolysis: Edexcel GCSE Combined Science questions
Every Edexcel GCSE Combined Science exam question on Electrolysis (specification points 3.22–3.31), 2018–2025, with its mark scheme and examiner’s report.
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Q5(c)
The whole paper ↗Q4(a)(i)
The whole paper ↗Q4(a)(ii)
The whole paper ↗Q4(a)(iii)
The whole paper ↗Q4(b)(i)
The whole paper ↗Q4(b)(ii)
The whole paper ↗Q4(b)(iii)
The whole paper ↗Q4(c)(i)
The whole paper ↗Q4(c)(ii)
The whole paper ↗Q4(c)(iii)
The whole paper ↗Q4(a)
The whole paper ↗Q4(b)(i)
The whole paper ↗Q4(b)(ii)
The whole paper ↗Q2(a)
The whole paper ↗Q2(b)(i)
The whole paper ↗Q2(b)(ii)
The whole paper ↗Q2(b)(iii)
The whole paper ↗Q4(b)(vi)
The whole paper ↗Q3(a)
The whole paper ↗Q3(b)
The whole paper ↗
All 60 questions on Electrolysis, as a list
- June 2025, Chemistry Paper 1 Higher, Q5(c) (6 marks): Magnesium sulfate solution can be electrolysed using the apparatus shown in Figure 3. oxygen hydrogen magnesium sulfate solution positive negative + – electrod
- June 2024, Chemistry Paper 1 Higher, Q4(a)(i) (2 marks): In this electrolysis, the acidified water is an electrolyte. Explain why acidified water is an electrolyte. (2)
- June 2024, Chemistry Paper 1 Higher, Q4(a)(ii) (1 mark): Hydrogen collects at the negative electrode and oxygen collects at the positive electrode. Which of these shows the results after 10 minutes of this electrolysi
- June 2024, Chemistry Paper 1 Higher, Q4(a)(iii) (2 marks): Complete and balance the half equation for the formation of oxygen at the positive electrode in this electrolysis. (2) 4OH– →
- June 2024, Chemistry Paper 1 Higher, Q4(b)(i) (2 marks): Describe what should be done to the copper cathode, after it has been removed from the copper sulfate solution, before its final mass is determined. (2)
- June 2024, Chemistry Paper 1 Higher, Q4(b)(ii) (2 marks): Explain, in terms of ions, the change in mass of the cathode shown in Figure 3. (2)
- June 2024, Chemistry Paper 1 Higher, Q4(b)(iii) (2 marks): Explain why the appearance of the copper sulfate solution did not change during the electrolysis. (2)
- June 2024, Chemistry Paper 1 Foundation, Q4(c)(i) (2 marks): Give two reasons why graphite is a suitable material for the electrodes. (2) 1 2
- June 2024, Chemistry Paper 1 Foundation, Q4(c)(ii) (1 mark): Sodium sulfate solution contains ions. Which ions are attracted to the positive electrode during the electrolysis? (1) A H+ ions only B OH– ions only C H+ and N
- June 2024, Chemistry Paper 1 Foundation, Q4(c)(iii) (2 marks): Draw one straight line from each electrode to the product formed at that electrode during the electrolysis of sodium sulfate solution. (2) electrode product hyd
- June 2023, Chemistry Paper 1 Higher, Q4(a) (1 mark): Where is copper formed during the electrolysis? (1) A at the anode B at the bottom of the beaker C at the cathode D on the surface of the electrolyte
- June 2023, Chemistry Paper 1 Higher, Q4(b)(i) (3 marks): State and explain the trend shown in these results. (3)
- June 2023, Chemistry Paper 1 Higher, Q4(b)(ii) (2 marks): Describe how, after the power supply has been switched off, the mass of copper formed can be measured. (2)
- June 2023, Chemistry Paper 1 Foundation, Q2(a) (1 mark): Which statement describes what happens during electrolysis? (1) A atoms are decomposed B ionic compounds are decomposed C mixtures are separated D molecules are
- June 2023, Chemistry Paper 1 Foundation, Q2(b)(i) (2 marks): Use the words from the box to complete the labelling of the diagram in Figure 3. (2) anode cathode electrolyte 6 V d.c. supply – + solid X gas Y Figure 3
- June 2023, Chemistry Paper 1 Foundation, Q2(b)(ii) (2 marks): The products of the electrolysis shown in Figure 3 are solid X and gas Y. Draw one straight line from each product to its name. (2) product name carbon solid X
- June 2023, Chemistry Paper 1 Foundation, Q2(b)(iii) (2 marks): The experiment is repeated using powdered solid copper chloride instead of copper chloride solution. Nothing happens and no products are formed. Explain why not
- June 2023, Chemistry Paper 2 Foundation, Q4(b)(vi) (1 mark): Sodium chloride solution conducts electricity. 6V d.c. circuit supply electrode electrode sodium chloride solution Figure 8 State what can be put into the circu
- June 2022, Chemistry Paper 1 Higher, Q3(a) (2 marks): Draw a labelled diagram to show the apparatus that can be used to electrolyse copper sulfate solution using copper electrodes. (2)
- June 2022, Chemistry Paper 1 Higher, Q3(b) (2 marks): Before the electrolysis is carried out, the mass of each electrode is determined. Explain what should be done to the copper electrodes before their masses are d
- June 2022, Chemistry Paper 1 Higher, Q3(c)(i) (3 marks): Explain, in terms of ions, the changes in mass of the two electrodes shown in the results in Figure 2. (3)
- June 2022, Chemistry Paper 1 Higher, Q3(c)(ii) (2 marks): The electrolysis was repeated using another pair of copper electrodes of the same masses. Explain a change that could be made to the electrolysis experiment to
- June 2022, Chemistry Paper 1 Foundation, Q4(c)(i) (1 mark): Figure 7 shows the ions in the sodium sulfate solution. Draw a circle around each of the ions in Figure 7 that are attracted to the negative graphite electrode
- June 2022, Chemistry Paper 1 Foundation, Q4(c)(ii) (1 mark): State why it is important that the electrodes are inert. (1)
- November 2021, Chemistry Paper 1 Higher, Q3(a) (1 mark): A sample of molten potassium bromide is electrolysed. What are the two products formed? (1) A hydrogen and oxygen B hydrogen and bromine C potassium and oxygen
- November 2021, Chemistry Paper 1 Higher, Q3(b) (2 marks): Zinc chloride and zinc carbonate contain ions. Zinc chloride mixed with water can be electrolysed. Zinc carbonate mixed with water cannot be electrolysed. Expla
- November 2021, Chemistry Paper 1 Higher, Q3(c)(i) (1 mark): Identify this gas. (1)
- November 2021, Chemistry Paper 1 Higher, Q3(c)(ii) (2 marks): Explain how this gas is formed at the cathode. (2)
- November 2021, Chemistry Paper 1 Higher, Q3(d)(i) (2 marks): Draw a labelled diagram to show how this experiment would be set up. The beaker has been drawn for you. (2) beaker
- November 2021, Chemistry Paper 1 Higher, Q3(d)(ii) (3 marks): During the electrolysis, the anode gets smaller, the cathode gets larger and the solution remains the same shade of blue. Give the reason for each of these obse
- November 2021, Chemistry Paper 1 Foundation, Q4(b)(i) (1 mark): Give the name of the piece of apparatus labelled X. (1)
- November 2021, Chemistry Paper 1 Foundation, Q4(b)(ii) (1 mark): The rod labelled Y in Figure 4 is made of graphite. What is the name of this piece of apparatus? (1) A electrode B electrolysis C electrolyte D electron
- November 2021, Chemistry Paper 1 Foundation, Q4(b)(iii) (1 mark): Give one reason why graphite is a suitable material to make Y. (1)
- November 2021, Chemistry Paper 1 Foundation, Q4(b)(iv) (1 mark): Complete the balanced equation for the reaction that occurs. (1) HCl → H2 + Cl2
- November 2020, Chemistry Paper 1 Higher, Q1(a)(i) (2 marks): Describe the test to show the gas is hydrogen. (2)
- November 2020, Chemistry Paper 1 Higher, Q1(a)(ii) (1 mark): What is the name of gas X that forms at the positive electrode? (1) A ammonia B oxygen C nitrogen D sulfur dioxide
- November 2020, Chemistry Paper 1 Higher, Q1(a)(iii) (2 marks): State what is meant by the term electrolysis. (2)
- November 2020, Chemistry Paper 1 Foundation, Q5(a)(i) (2 marks): Describe the test to show the gas is hydrogen. (2)
- November 2020, Chemistry Paper 1 Foundation, Q5(a)(ii) (1 mark): What is the name of gas X that forms at the positive electrode? (1) A ammonia B oxygen C nitrogen D sulfur dioxide
- November 2020, Chemistry Paper 1 Foundation, Q5(a)(iii) (2 marks): State what is meant by the term electrolysis. (2)
- November 2020, Chemistry Paper 1 Foundation, Q5(d)(i) (1 mark): In Figure 6, the gases given off at the electrodes are collected in test-tubes. However, the actual volume of gases cannot be measured using these test-tubes. S
- November 2020, Chemistry Paper 1 Foundation, Q5(d)(ii) (1 mark): State what could be added into the circuit to show a current is flowing during electrolysis. (1)
- June 2019, Chemistry Paper 1 Higher, Q2(a)(i) (1 mark): A sample of hydrogen is mixed with air and ignited. State what would happen. (1)
- June 2019, Chemistry Paper 1 Higher, Q2(a)(ii) (2 marks): Throughout the experiment the volume of hydrogen and the volume of oxygen are measured at two-minute intervals. The results are shown in Figure 2. volume of hyd
- June 2019, Chemistry Paper 1 Higher, Q2(b) (1 mark): Molten lead bromide is electrolysed. The products of this electrolysis are (1) A hydrogen and bromine B hydrogen and oxygen C lead and bromine D lead and oxygen
- June 2019, Chemistry Paper 1 Higher, Q2(c) (2 marks): Calcium nitrate and calcium carbonate are both ionic compounds. Calcium nitrate mixed with water behaves as an electrolyte. Calcium carbonate mixed with water d
- June 2019, Chemistry Paper 1 Higher, Q2(d) (2 marks): When molten zinc chloride is electrolysed, zinc ions, Zn2+, form zinc atoms. Write the half equation for this reaction. (2)
- June 2019, Chemistry Paper 1 Foundation, Q4(c)(ii) (2 marks): Complete the balanced equation for the overall reaction by putting numbers in the spaces. (2) 2Al2O3 o Al + O2
- June 2019, Chemistry Paper 1 Foundation, Q6(a)(ii) (2 marks): Throughout the experiment the volume of hydrogen and the volume of oxygen are measured at two-minute intervals. The results are shown in Figure 6. volume of hyd
- June 2019, Chemistry Paper 1 Foundation, Q6(b) (1 mark): Molten lead bromide is electrolysed. The products of this electrolysis are (1) A hydrogen and bromine B hydrogen and oxygen C lead and bromine D lead and oxygen
- June 2019, Chemistry Paper 1 Foundation, Q6(c) (2 marks): Calcium nitrate and calcium carbonate are both ionic compounds. Calcium nitrate mixed with water behaves as an electrolyte. Calcium carbonate mixed with water d
- June 2019, Chemistry Paper 1 Foundation, Q6(d) (6 marks): Impure copper can be purified using electrolysis. In this electrolysis • the anode is made of impure copper • the cathode is made from pure copper • the electro
- June 2018, Chemistry Paper 1 Higher, Q4(a)(i) (1 mark): Which row shows the products formed at the anode and at the cathode when molten zinc chloride is electrolysed? (1) product at anode product at cathode A oxygen
- June 2018, Chemistry Paper 1 Higher, Q4(a)(ii) (1 mark): Which of the following is the reason why molten zinc chloride is an electrolyte? (1) A it contains molecules that can move B it has a giant structure C it conta
- June 2018, Chemistry Paper 1 Higher, Q4(b)(i) (2 marks): Draw a labelled diagram to show the apparatus that is used to carry out this electrolysis in the laboratory. (2)
- June 2018, Chemistry Paper 1 Higher, Q4(b)(ii) (4 marks): Before the electrolysis, the masses of the electrodes were determined. After the electrolysis, the electrodes were washed and dried and their masses re-determin
- June 2018, Chemistry Paper 1 Higher, Q4(c) (2 marks): When sodium sulfate solution is electrolysed, using inert electrodes, hydrogen is formed at the cathode. +. Write the half equation for the formation of hydroge
- June 2018, Chemistry Paper 1 Foundation, Q3(e)(i) (1 mark): State why sodium chloride solution, rather than solid sodium chloride, must be used in this experiment. (1)
- June 2018, Chemistry Paper 1 Foundation, Q3(e)(ii) (1 mark): The formulae of the ions present in the sodium chloride solution are Na+ Cl– H+ OH– Circle the ions that would be attracted to the anode. (1)
- June 2018, Chemistry Paper 1 Foundation, Q3(e)(iii) (2 marks): Molten lead bromide can be electrolysed to form molten lead and bromine gas. Explain how a student could modify the apparatus shown in Figure 5 to carry out thi
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