The equation representing the standard electrode potential, E°, for the reduction of MnO₄⁻(aq) to Mn²⁺(aq) in acid solution is given. MnO₄⁻(aq) + 8H⁺(aq) + 5e⁻ ⇋ Mn²⁺(aq) + 4H₂O(l) E° = +1.52V

1. (a)Identify the substances liberated at the anode and at the cathode during the electrolysis of aqueous sodium sulfate, Na₂SO₄(aq). anode cathode[1]
2. (b)When molten sodium chloride is electrolysed, chlorine is liberated at the anode and sodium is liberated at the cathode. A sample of molten sodium chloride is electrolysed for 1.50 hours using a current of 4.50 A. Calculate the volume of chlorine and the mass of sodium that are liberated under room conditions. volume of chlorine = dm³ mass of sodium = g[4]
3. (c)(i)Draw a diagram of the apparatus that would be used to measure the E° value of this half-cell. Your diagram should be fully labelled to identify all apparatus, substances and conditions.[4]
4. (c)(ii)Use the Data Booklet to identify a substance that could be used to oxidise Mn²⁺ ions to MnO₄⁻ ions under standard conditions. Write an equation for the reaction.[2]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.