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 85 · Normal
Question 61
3 marks · Normal
Answer and see the solution →Describe how the appearance and composition of copper(II) sulfate solution change after it is electrolysed for a long period using inert electrodes.
Question 62
4 marks · Normal
Answer and see the solution →The following table shows the observations at the electrodes during electrolysis of copper(II) sulfate solution with inert electrodes.
(a)[0 marks]Observations during Electrolysis Electrode Observation Cathode Pink/brown coating forms Anode Gas bubbles produced (b)[1 mark]Name the substance forming the pink/brown coating at the cathode.
(c)[1 mark]Name the gas produced at the anode.
(d)[2 marks]Suggest a simple test to confirm the identity of the gas collected at the anode.
Question 63
1 mark · Normal
Answer and check →Which of the following is the correct balanced half-equation for the reaction at the anode during the electrolysis of copper(II) sulfate solution using inert electrodes?
- A.Cu^{2+}(aq) + 2e^- \rightarrow Cu(s)
- B.2Cl^-(aq) \rightarrow Cl_2(g) + 2e^-
- C.4OH^-(aq) \rightarrow 2H_2O(l) + O_2(g) + 4e^-
- D.H^+(aq) + e^- \rightarrow H_2(g)
Question 64
2 marks · Normal
Answer and see the solution →Explain why oxygen gas is produced at the anode during the electrolysis of copper(II) sulfate solution with inert electrodes.
Question 65
4 marks · Normal
Answer and see the solution →Copper(II) sulfate solution is electrolysed using inert electrodes for a long time.
(a)[2 marks]Describe what happens to the colour of the solution.
(b)[2 marks]Explain why these changes occur.
Question 66
2 marks · Normal
Answer and see the solution →State the products formed at the cathode and at the anode when dilute sodium sulfate solution is electrolysed using inert electrodes.
Question 67
4 marks · Normal
Answer and see the solution →Potassium chloride solution is electrolysed using inert electrodes.
(a)[1 mark]State whether hydrogen or potassium is formed at the cathode.
(b)[2 marks]Explain why this product is formed at the cathode, using the reactivity series.
(c)[1 mark]Name the product formed at the anode.
Question 68
3 marks · Normal
Answer and see the solution →Electrolysis of aqueous copper(II) nitrate solution was carried out using inert electrodes. No copper was deposited at the cathode.
Explain which products are formed at the cathode and anode, and why these products are formed.
Question 69
4 marks · Normal
Answer and see the solution →The table shows part of the reactivity series and the likely product at the cathode during the electrolysis of an aqueous solution of the metal compound.
Metal Relative position (above/below H) Product at cathode Potassium Above Hydrogen Copper Below ? Sodium Above Hydrogen Silver Below ? a) Complete the column for 'Product at cathode' for copper and silver.
b) Explain, using the reactivity series, why these products are formed for copper and silver.
(a)[2 marks](b)[2 marks]Question 70
1 mark · Normal
Answer and check →Which of the following anions will produce oxygen gas at the anode, rather than a halogen, during electrolysis of an aqueous solution?
- A.Chloride (Cl⁻)
- B.Bromide (Br⁻)
- C.Sulfate (SO₄²⁻)
- D.Iodide (I⁻)