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
31–40 of 198
Question 31
4 marks · Normal
Answer and see the solution →(a)[2 marks]Describe how you would set up an experiment to investigate the electrolysis of molten sodium chloride (). Include the apparatus you would use.
(b)[1 mark]State one safety precaution that should be taken when carrying out this experiment.
(c)[1 mark]What observation would show that electrolysis is taking place?
Question 32
3 marks · Normal
Answer and see the solution →(a)[1 mark]A student investigates electrolysis using an aqueous solution of potassium iodide () and two inert electrodes.
State the name given to the compound in solution that conducts electricity in this experiment.
(b)[1 mark]Name (i) the positive electrode, and (ii) the negative electrode.
(c)[1 mark]During the experiment, which direction do the cations move in the electrolyte?
Question 33
3 marks · Normal
Answer and see the solution →Explain why covalent molecular compounds such as methane () do not conduct electricity, but aqueous ammonia () can conduct electricity. Refer to the presence or absence of ions in your answer.
Question 34
4 marks · Normal
Answer and see the solution →A student recorded observations of three substances to analyse their ability to conduct electricity in different states.
(a)[2 marks]Data about electrical conduction by different substances Substance Solid Molten Aqueous Sodium chloride no yes yes Sugar no no no Potassium nitrate no yes yes Which of these substances are ionic compounds? Explain your answer using the data.
(b)[1 mark]Suggest why sugar does not conduct electricity in any state.
(c)[1 mark]Which substance is an example of a covalent compound?
Question 35
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 36
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 37
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 38
1 mark · Easy
Answer and see the solution →State the product formed at the cathode during the electrolysis of molten calcium chloride ().
Question 39
3 marks · Easy
Answer and see the solution →The diagram shows the apparatus used to electrolyse molten lithium iodide ().
Electrolysis apparatus for molten LiI Answer the following questions about this electrolysis.
(a)[1 mark]Name the ion in molten that is attracted to the cathode.
(b)[1 mark]State what is formed at the anode.
(c)[1 mark]Write the half-equation for the reaction at the cathode.
Question 40
2 marks · Easy
Answer and see the solution →Write the balanced half-equation for the reaction at the anode during the electrolysis of molten potassium bromide (), and state how many electrons are involved per bromine molecule formed.