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
41–50 of 198
Question 41
3 marks · Easy
Answer and see the solution →The table below shows the ions present in three molten ionic compounds:
Compound Ions present A: MgF_2 B: KCl C: CaBr_2 (a)[1 mark]For compound B, name the product formed at the anode.
(b)[1 mark]For compound C, write the half-equation for the reaction at the cathode.
(c)[1 mark]For compound A, state the formula of the ion that gains electrons at the cathode.
Question 42
1 mark · Easy
Answer and see the solution →Write the formula of the ion that is reduced at the cathode when molten barium chloride () is electrolysed.
Question 43
3 marks · Easy
Answer and see the solution →Molten tin(II) chloride () is electrolysed using inert electrodes.
(a)[1 mark]Name the element formed at the cathode.
(b)[1 mark]Write the half-equation for the reaction at the anode.
(c)[1 mark]Explain briefly what happens to the ions during electrolysis.
Question 44
2 marks · Easy
Answer and see the solution →During the electrolysis of molten sodium bromide (), write the half-equation for the reaction at the cathode. State the number of electrons gained by each sodium ion.
Question 45
2 marks · Easy
Answer and see the solution →Molten calcium iodide () is electrolysed using inert electrodes.
(a)[1 mark]Write the half-equation for the reaction that occurs at the cathode during the electrolysis of molten calcium iodide.
(b)[1 mark]Explain why iodide ions move to the anode in this process.
Question 46
2 marks · Normal
Answer and see the solution →State the products formed at the electrodes when molten sodium chloride is electrolysed. For each product, name the electrode where it forms.
Question 47
4 marks · Normal
Answer and see the solution →Aluminium oxide can be electrolysed when molten.
(a)[1 mark]State the names and formulas of the ions present in molten aluminium oxide.
(b)[1 mark]Write the half-equation for the reaction at the cathode.
(c)[1 mark]Write the half-equation for the reaction at the anode.
(d)[1 mark]Identify the product formed at each electrode.
Question 48
4 marks · Normal
Answer and see the solution →A student investigates the electrolysis of three different molten ionic compounds using carbon electrodes. The table below shows the ions present in each compound.
Compound Cation(s) Anion(s) Magnesium bromide (MgBr2) Mg^{2+} Br^- Potassium iodide (KI) K^+ I^- Calcium chloride (CaCl2) Ca^{2+} Cl^- (a)[1 mark]For magnesium bromide, state the product formed at the anode.
(b)[1 mark]For potassium iodide, state the product formed at the cathode.
(c)[2 marks]Write the half-equation for the reaction at the anode when calcium chloride is electrolysed.
Question 49
1 mark · Normal
Answer and check →Which of the following half-equations correctly represents the reaction occurring at the anode during the electrolysis of molten potassium bromide (KBr)?
- A.Br^- → Br_2 + 2e^-
- B.K^+ + e^- → K
- C.2Br^- → Br_2 + 2e^-
- D.K^+ → K + e^-
Question 50
2 marks · Normal
Answer and see the solution →Write the half-equation for the reaction at the cathode during the electrolysis of molten zinc chloride (ZnCl_2). State what is observed at the cathode.