Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Electrolysis
198 practice questions
Topics covered
- Why things conduct electricity17 practice questions
- Passing electricity through compounds: electrolysis20 practice questions
- The electrolysis of molten compounds19 practice questions
- Electrolysis and redox19 practice questions
- The electrolysis of other molten substances19 practice questions
- The electrolysis of aqueous solutions18 practice questions
- The electrolysis of sodium chloride solution19 practice questions
- The electrolysis of copper(ii) sulfate solution using inert electrodes18 practice questions
- The electrolysis of some other solutions using inert electrodes19 practice questions
- What would happen with non-electrolytes?19 practice questions
Practice questions
61–70 of 198
Question 61
3 marks · Easy
Answer and see the solution →Table 1 shows the electron profiles for three different reactions.
Table 1: Electron Transfer in Different Reactions Process Type of Particle Electron Change W Iron(III) ion gains 3 electrons X Chloride ion loses 1 electron Y Copper(II) ion gains 2 electrons (a)[1 mark]Identify the process (W, X or Y) that involves oxidation.
(b)[1 mark]State what reduction means in terms of electron transfer.
(c)[1 mark]Identify all processes (W, X or Y) that involve reduction.
Question 62
1 mark · Easy
Answer and see the solution →When an ion is 'discharged' during electrolysis, what happens to its electric charge?
Question 63
3 marks · Easy
Answer and see the solution →During the electrolysis of molten copper(II) bromide (CuBr), the following reactions occur:
(a)[1 mark]Write the half-equation for the reaction at the anode.
(b)[1 mark]State whether the anode reaction is oxidation or reduction.
(c)[1 mark]Explain your answer to (b) using electron transfer.
Question 64
2 marks · Easy
Answer and see the solution →An aluminium ion (Al) gains 3 electrons during electrolysis.
(a)[1 mark]State whether this process is oxidation or reduction.
(b)[1 mark]Explain your answer using the OILRIG mnemonic.
Question 65
2 marks · Normal
Answer and see the solution →State what is meant by:
(a)[1 mark]oxidation, in terms of electron transfer.
(b)[1 mark]reduction, in terms of electron transfer.
Question 66
4 marks · Normal
Answer and see the solution →The diagram shows an apparatus used in the electrolysis of molten lead(II) iodide. The electrodes and power supply are labelled.
(a)[2 marks]Explain what is meant by 'discharging an ion' during electrolysis.
(b)[1 mark]State what happens to the lead(II) ions at the cathode, referring to electron transfer.
(c)[1 mark]Write the ionic half-equation for the reaction at the anode.
Question 67
3 marks · Normal
Answer and see the solution →The electrolysis of molten potassium chloride (KCl) produces potassium metal and chlorine gas.
(a)[1 mark]Write the half-equation for the reaction at the cathode.
(b)[1 mark]State whether the reaction at the cathode is oxidation or reduction.
(c)[1 mark]Explain your answer to part (b) in terms of electron transfer.
Question 68
3 marks · Normal
Answer and see the solution →A student wants to remember whether oxidation or reduction involves losing or gaining electrons.
(a)[1 mark]State the mnemonic used to remember this.
(b)[1 mark]What does each letter in the mnemonic stand for?
(c)[1 mark]Explain, using the mnemonic, what happens to an ion that gains electrons.
Question 69
4 marks · Normal
Answer and see the solution →Table 1: Electrode Reactions Ion Half-equation Cl^- 2Cl^- \rightarrow Cl_2 + 2e^- Ag^+ Ag^+ + e^- \rightarrow Ag Fe^{3+} Fe^{3+} + 3e^- \rightarrow Fe O^{2-} 2O^{2-} \rightarrow O_2 + 4e^- Study Table 1. For each reaction below, state whether the ion is oxidised or reduced and explain why using electron transfer.
(a)[1 mark]Cl^- \rightarrow Cl_2 + 2e^-
(b)[1 mark]Ag^+ + e^- \rightarrow Ag
(c)[1 mark]Fe^{3+} + 3e^- \rightarrow Fe
(d)[1 mark]O^{2-} \rightarrow O_2 + 4e^-
Question 70
1 mark · Normal
Answer and check →In the electrolysis of molten zinc bromide, what does it mean to 'discharge' a zinc ion (Zn^{2+}) at the cathode?
- A.Zinc ions lose electrons to form zinc atoms.
- B.Zinc ions gain electrons to form zinc atoms.
- C.Zinc atoms lose electrons to form zinc ions.
- D.Zinc ions are removed from the solution by evaporation.