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
161–170 of 198
Question 161
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 162
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 163
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 164
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 165
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 166
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 167
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 168
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
Question 169
1 mark · Easy
Answer and see the solution →State what you would observe if you tested solid sucrose (sugar) for electrical conductivity using an electric circuit with a bulb.
Question 170
3 marks · Easy
Answer and see the solution →A student investigates the conductivity of three white solids: sodium chloride, glucose, and wax. She sets up the following experiment:
Simple circuit for testing conductivity of solids (a)[1 mark]Sodium chloride does not conduct electricity as a solid, but the bulb lights up when it is dissolved in water. What does this indicate about sodium chloride?
(b)[1 mark]Glucose does not conduct electricity, whether solid or dissolved in water. What type of substance is glucose?
(c)[1 mark]Wax does not conduct electricity as a solid or when melted. What does this suggest about wax?