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
1–10 of 33 · Hard
Question 1
2 marks · Hard
Answer and see the solution →Explain why pure, solid silver chloride does not conduct electricity, but when dissolved in water, it does.
Question 2
5 marks · Hard
Answer and see the solution →A teacher tests the electrical conductivity of four substances in different states. The results are shown in the table below.
Conductivity of substances in different states Substance State Conducts electricity? Potassium nitrate Solid No Potassium nitrate Aqueous Yes Sulfur dioxide Liquid No Lead(II) bromide Molten Yes (a)[1 mark]Identify which of the substances in the table are ionic compounds.
(b)[2 marks]Explain why potassium nitrate conducts electricity when dissolved in water but not as a solid.
(c)[2 marks]Suggest why sulfur dioxide does not conduct electricity, even when liquid. Use your knowledge of bonding.
Question 3
2 marks · Hard
Answer and see the solution →Explain, with reference to structure and particles, why molten lead(II) bromide can conduct electricity.
Question 4
2 marks · Hard
Answer and see the solution →State the name given to (a) the positive electrode and (b) the liquid or solution that contains ions and undergoes electrolysis. Give both answers.
Question 5
5 marks · Hard
Answer and see the solution →(a)[2 marks]Define what is meant by each of the following terms in relation to electrolysis: (i) anion, (ii) cation.
(b)[3 marks]Describe what happens during the electrolysis of molten potassium bromide (). In your answer, refer to the movement and discharge of ions at the electrodes.
Question 6
2 marks · Hard
Answer and see the solution →A student investigates the electrolysis of molten lead(II) bromide () using inert electrodes.
State one observation the student would make at each electrode during this experiment.
Question 7
2 marks · Hard
Answer and see the solution →During the electrolysis of molten silver(I) chloride ( ), inert electrodes are used.
Write the half-equation for the reaction that occurs at the cathode. State whether reduction or oxidation is taking place at the cathode.
Question 8
5 marks · Hard
Answer and see the solution →Molten iron(III) bromide ( ) is electrolysed using inert electrodes.
(a)[1 mark]State the formulae of the ions present in molten .
(b)[1 mark]Identify the product formed at the cathode.
(c)[1 mark]Write the half-equation for the reaction at the cathode.
(d)[1 mark]Write the half-equation for the reaction at the anode.
(e)[1 mark]Explain why only the ions in are discharged during the electrolysis of its molten form.
Question 9
2 marks · Hard
Answer and see the solution →Write the half-equation for the reaction at the anode during the electrolysis of molten cadmium(II) iodide ( ).
Explain why this reaction is classified as oxidation.
Question 10
2 marks · Hard
Answer and see the solution →Define oxidation and reduction in terms of electron transfer. Give your answers using complete sentences.