Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
The electrolysis of some other solutions using inert electrodes
19 practice questions
Practice questions
11–19 of 19
Question 11
3 marks · Normal
Answer and see the solution →Electrolysis of aqueous copper(II) nitrate solution was carried out using inert electrodes. No copper was deposited at the cathode.
Explain which products are formed at the cathode and anode, and why these products are formed.
Question 12
4 marks · Normal
Answer and see the solution →The table shows part of the reactivity series and the likely product at the cathode during the electrolysis of an aqueous solution of the metal compound.
Metal Relative position (above/below H) Product at cathode Potassium Above Hydrogen Copper Below ? Sodium Above Hydrogen Silver Below ? a) Complete the column for 'Product at cathode' for copper and silver.
b) Explain, using the reactivity series, why these products are formed for copper and silver.
(a)[2 marks](b)[2 marks]Question 13
1 mark · Normal
Answer and check →Which of the following anions will produce oxygen gas at the anode, rather than a halogen, during electrolysis of an aqueous solution?
- A.Chloride (Cl⁻)
- B.Bromide (Br⁻)
- C.Sulfate (SO₄²⁻)
- D.Iodide (I⁻)
Question 14
2 marks · Normal
Answer and see the solution →Name the gases formed at the anode and at the cathode when dilute sulfuric acid is electrolysed with inert electrodes.
Question 15
4 marks · Normal
Answer and see the solution →A student electrolyses aqueous magnesium sulfate using inert electrodes.
(a)[1 mark]State the gas formed at the cathode.
(b)[2 marks]Explain why this product is formed at the cathode, using the reactivity series.
(c)[1 mark]Name the ion that is discharged at the anode.
Question 16
3 marks · Normal
Answer and see the solution →A student electrolyses an aqueous solution of sodium sulfate using inert electrodes.
She collects 120 cm³ of gas at the anode over a period of time.
Only two types of negative ions are present: sulfate ions and hydroxide ions.
State which ion is discharged at the anode, write the ionic equation for the reaction, and calculate the volume of oxygen molecules produced in moles (to 2 significant figures). (1 mol of any gas occupies 24 000 cm³ at room temperature and pressure.)
(a)[1 mark]State which ion is discharged at the anode.
(b)[1 mark]Write the ionic half-equation for the reaction at the anode.
(c)[1 mark]Calculate the amount of oxygen produced, in moles, to 2 significant figures.
Question 17
2 marks · Hard
Answer and see the solution →An aqueous solution of zinc sulfate is electrolysed using inert electrodes.
State whether hydrogen or zinc is produced at the cathode. Explain your answer using the reactivity series.
Question 18
5 marks · Hard
Answer and see the solution →A student electrolyses separate aqueous solutions containing different anions using inert electrodes.
(a)[1 mark]State which ion produces oxygen gas at the anode when an aqueous solution of sodium sulfate is electrolysed.
(b)[2 marks]Explain why oxygen is produced at the anode during this electrolysis and not another gas.
(c)[2 marks]During the electrolysis of aqueous sodium chloride with inert electrodes, state the product formed at the anode. Explain your answer.
Question 19
2 marks · Hard
Answer and see the solution →Predict the products formed at the electrodes when an aqueous solution of copper(II) bromide is electrolysed using inert electrodes.
State the product formed at:
(a)[1 mark]the cathode
(b)[1 mark]the anode