Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Passing electricity through compounds: electrolysis
20 practice questions
Practice questions
11–20 of 20
Question 11
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 12
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 13
2 marks · Normal
Answer and see the solution →State what is meant by (a) an anion, and (b) a cation.
Question 14
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 15
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 16
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 17
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 18
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 19
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 20
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.