plumiWhat are electrolytes and what happens during electrolysis?: OCR GCSE Combined Science B questions
Every OCR GCSE Combined Science B exam question on C3.3 What are electrolytes and what happens during electrolysis?, 2018–2025, with its mark scheme and examiner’s report.
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Q7(a)
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Q7(b)(i)
The whole paper ↗Q7(b)(ii)
The whole paper ↗Q9(a)(i)
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Q9(a)(ii)
The whole paper ↗Q9(a)(iii)
The whole paper ↗Q9(b)(i)
The whole paper ↗Q9(b)(ii)
The whole paper ↗Q9(b)(iii)
The whole paper ↗Q9(b)(iv)
The whole paper ↗Q9(a)(i)
The whole paper ↗
Q9(a)(ii)
The whole paper ↗Q9(a)(iii)
The whole paper ↗Q9(c)
The whole paper ↗Q6(a)(i)
The whole paper ↗Q6(a)(ii)
The whole paper ↗Q6(a)(iii)
The whole paper ↗Q6(b)
The whole paper ↗Q7(c)(i)
The whole paper ↗
Q7(c)(ii)
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All 38 questions on What are electrolytes and what happens during electrolysis?, as a list
- June 2024, Combined Science Paper 4 Foundation, Q7(a) (1 mark): Which ions are present in a concentrated solution of sodium chloride? Tick (✓) one box. Cl – H+ Na+ OH– Cl – H+ S2– OH– Cl – Na+ Cl – S2– [1]
- June 2024, Combined Science Paper 4 Foundation, Q7(b)(i) (1 mark): Name the gas that forms at the positive electrode. [1]
- June 2024, Combined Science Paper 4 Foundation, Q7(b)(ii) (2 marks): Describe a test to identify this gas that forms. [2]
- June 2024, Chemistry Paper 6 Higher, Q9(a)(i) (1 mark): Explain why the electrolysis must use molten aluminium oxide, and not solid aluminium oxide. [1]
- June 2024, Chemistry Paper 6 Higher, Q9(a)(ii) (3 marks): The half equations show the reactions at the electrodes. Al 3+ + 3e– Al 2O2– O2 + 4e– What is oxidised and what is reduced during the electrolysis of aluminium
- June 2024, Chemistry Paper 6 Higher, Q9(a)(iii) (4 marks): This is the balanced symbol equation for the decomposition of aluminium oxide by electrolysis: 2Al 2O3 4Al + 3O2 Calculate the mass of aluminium that will be pr
- June 2024, Chemistry Paper 6 Higher, Q9(b)(i) (3 marks): Complete the diagram to show how the gases can be collected by electrolysis of aqueous sodium sulfate. Include labels. + − [3]
- June 2024, Chemistry Paper 6 Higher, Q9(b)(ii) (1 mark): The ions present in aqueous sodium sulfate are Na+, SO4 2–, H+ and OH–. State where the H+ ions and OH– ions come from. [1]
- June 2024, Chemistry Paper 6 Higher, Q9(b)(iii) (1 mark): Explain why hydrogen is formed instead of sodium. [1]
- June 2024, Chemistry Paper 6 Higher, Q9(b)(iv) (3 marks): Complete the table to show where hydrogen gas and oxygen gas are formed and the half equations for the reactions occurring at each electrode. Electrode Product
- June 2023, Chemistry Paper 2 Foundation, Q9(a)(i) (2 marks): Complete the balanced symbol equation for the decomposition of aluminium oxide by electrolysis. 2Al 2O3 Al + O2 [2]
- June 2023, Chemistry Paper 2 Foundation, Q9(a)(ii) (2 marks): During electrolysis, reactions take place at the positive and negative electrodes. Complete the table to explain the reactions at each electrode. Use the diagra
- June 2023, Chemistry Paper 2 Foundation, Q9(a)(iii) (1 mark): Explain why carbon dioxide is also produced. [1]
- June 2023, Chemistry Paper 2 Foundation, Q9(c) (6 marks): The diagram shows how aluminium is extracted from its ore by electrolysis of molten aluminium oxide. It is carried out at high temperature with carbon electrode
- June 2022, Combined Science Paper 8 Higher, Q6(a)(i) (2 marks): Which two substances could be separated by electrolysis? Tick (✓) two boxes. Diamond Graphite Lead bromide Potassium chloride Silicon dioxide [2]
- June 2022, Combined Science Paper 8 Higher, Q6(a)(ii) (2 marks): Amir uses a sodium chloride solution and wants to collect the gases given off at the electrodes. The diagram shows the equipment he plans to use. test tube NaCl
- June 2022, Combined Science Paper 8 Higher, Q6(a)(iii) (2 marks): Name the gas formed at each electrode during the electrolysis of sodium chloride solution. Anode Cathode [2]
- June 2022, Combined Science Paper 8 Higher, Q6(b) (2 marks): During the electrolysis of a molten ionic compound the reaction taking place at each of the electrodes is either oxidation or reduction. Write the balanced half
- November 2021, Chemistry Paper 2 Foundation, Q7(c)(i) (2 marks): Explain why solid ionic compounds must be melted before electrolysis. [2]
- November 2021, Chemistry Paper 2 Foundation, Q7(c)(ii) (1 mark): Give the name of the product formed at each electrode when molten sodium chloride is electrolysed. Positive electrode Negative electrode [1]
- November 2021, Chemistry Paper 6 Higher, Q8(a)(i) (2 marks): Explain why solid aluminium oxide cannot be electrolysed. Use ideas about ions in your answer. [2]
- November 2021, Chemistry Paper 6 Higher, Q8(a)(ii) (1 mark): The melting point of pure aluminium oxide is 2072 °C. Aluminium oxide dissolved in cryolite melts at approximately 900 °C. Explain one advantage of electrolysin
- November 2021, Chemistry Paper 6 Higher, Q8(b) (4 marks): The diagram shows the tank used for the electrolysis of aluminium oxide. Positive electrodes dip into the molten solution of aluminium oxide. The casing of the
- November 2020, Chemistry Paper 2 Foundation, Q3(c)(i) (2 marks): Explain why sodium chloride conducts electricity when it is molten but does not conduct electricity when it is solid. [2]
- November 2020, Chemistry Paper 2 Foundation, Q3(c)(ii) (2 marks): When electricity passes through molten sodium chloride it decomposes. Name the two products formed when molten sodium chloride decomposes. and [2]
- November 2020, Chemistry Paper 6 Higher, Q10(a) (3 marks): Explain the reactions at each electrode when molten sodium chloride is electrolysed. Use ideas about oxidation, reduction, and electrons in your answer. [3]
- November 2020, Chemistry Paper 6 Higher, Q10(b)(i) (2 marks): Draw a fully labelled diagram in the box to show how he does this. [2]
- November 2020, Chemistry Paper 6 Higher, Q10(b)(ii) (2 marks): Sodium chloride solution contains sodium and chloride ions dissolved in water. Give the names and formulae for the ions that come from the water. Names: and For
- November 2020, Chemistry Paper 6 Higher, Q10(b)(iii) (3 marks): When Alex passes electricity through the sodium chloride solution, he sees bubbles of hydrogen gas forming at the negative electrode. Explain why, at the negati
- November 2020, Chemistry Paper 6 Higher, Q10(b)(iv) (2 marks): Suggest what Alex could do to test for the presence of chlorine gas at the positive electrode, and what the test will show if chlorine gas is present. [2]
- June 2019, Chemistry Paper 2 Foundation, Q5(b)(i) (1 mark): What state is molten aluminium oxide in? Put a ring around the correct answer. gas liquid solvent solution [1] Fig. 5.1 shows the ions in molten aluminium oxide
- June 2019, Chemistry Paper 2 Foundation, Q5(b)(ii) (2 marks): Molten aluminium oxide conducts electricity. Solid aluminium oxide does not. Explain why, using Fig. 5.1 to help you. [2]
- June 2019, Chemistry Paper 2 Foundation, Q5(b)(iii) (2 marks): A positive and negative electrode are used to pass electricity through molten aluminium oxide. A product is made at each electrode. Draw lines to join each elec
- June 2018, Chemistry Paper 6 Higher, Q7(a) (3 marks): The aluminium oxide must be molten in this process so that it conducts electricity. Explain why aluminium oxide conducts electricity when it is liquid but not w
- June 2018, Chemistry Paper 6 Higher, Q7(b)(i) (3 marks): Complete the table to show the product and half equation at the positive electrode. Name of Electrode Half equation product Al3+ + 3e- → Al Negative aluminium P
- June 2018, Chemistry Paper 6 Higher, Q7(b)(ii) (1 mark): Complete the following sentence by putting a ring around the correct words: The reaction at the negative electrode is oxidation / reduction because electrons ar
- June 2018, Chemistry Paper 6 Higher, Q7(d)(i) (1 mark): Explain why aluminium is not formed at the negative electrode. [1]
- June 2018, Chemistry Paper 6 Higher, Q7(d)(ii) (3 marks): Name the gas that forms at the negative electrode and explain why this gas is produced during the electrolysis. [3]
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