Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Passing electricity through compounds: electrolysis
20 practice questions
Practice questions
1–9 of 9 · Normal
Question 1
2 marks · Normal
Answer and see the solution →State the charges of (a) a cation and (b) an anion.
(a)[1 mark]Cation
(b)[1 mark]Anion
Question 2
4 marks · Normal
Answer and see the solution →An experiment is set up to investigate the electrolysis of molten potassium iodide using inert carbon electrodes.
(a)[1 mark]State the name given to the liquid that conducts electricity during electrolysis.
(b)[2 marks]Describe how you would safely set up an experiment to carry out electrolysis on molten potassium iodide, naming the electrodes you would use.
(c)[1 mark]State one safety precaution you should take during this experiment.
Question 3
3 marks · Normal
Answer and see the solution →The diagram below represents an electrolytic cell with a solution of sodium chloride ( ) and two electrodes.
(a)[1 mark]Name the electrode where reduction occurs.
(b)[1 mark]Give the name and charge of the ions that move to the anode in this process.
(c)[1 mark]State the term used for the substance, other than electrodes, that is necessary for electrolysis to occur in this experiment.
Question 4
3 marks · Normal
Answer and see the solution →Explain why molten magnesium chloride ( ) conducts electricity, but solid magnesium chloride does not. Use your knowledge of ionic compounds and their structure.
Question 5
2 marks · Normal
Answer and see the solution →State what is meant by (a) an anion, and (b) a cation.
Question 6
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 7
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 8
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 9
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?