Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
131–140 of 161 · Hard
Question 131
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 132
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 133
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 134
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 135
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 136
2 marks · Hard
Answer and see the solution →Define oxidation and reduction in terms of electron transfer. Give your answers using complete sentences.
Question 137
5 marks · Hard
Answer and see the solution →The apparatus below is used to electrolyse molten tin(II) chloride (SnCl₂). Tin(II) ions (Sn²⁺) and chloride ions (Cl⁻) move towards the electrodes and react.
Electrolysis setup for molten tin(II) chloride (a) State what is meant by 'discharging' a tin(II) ion during the electrolysis of molten tin(II) chloride.
(a)[2 marks]State what is meant by 'discharging' a tin(II) ion during the electrolysis of molten tin(II) chloride.
(b)[2 marks]Explain, in terms of electron transfer, what happens to a tin(II) ion at the cathode in this process.
(c)[1 mark]Write a half-equation for the reaction involving tin(II) ions at the cathode.
Question 138
2 marks · Hard
Answer and see the solution →The electrolysis of molten iron(III) chloride (FeCl₃) involves reactions at both electrodes.
State which electrode reaction involves oxidation, and which involves reduction. Explain your answer with reference to loss or gain of electrons.
Question 139
2 marks · Hard
Answer and see the solution →Balance the following ionic half-equation for the electrolysis of a molten ionic compound, so that both the number of atoms and the charges are equal on both sides:
where M represents a generic metal.
Question 140
5 marks · Hard
Answer and see the solution →A molten ionic compound XY is electrolysed using inert electrodes.
(a)[2 marks]State which element is produced at the cathode. Explain your answer.
(b)[2 marks]State which element is produced at the anode. Explain your answer.
(c)[1 mark]Give one reason why these predictions are valid only for molten binary ionic compounds, not aqueous ones.