Data should be selected from Table 3.1 in order to answer some parts of this question. Table 3.1 electrode reaction E° / V Cl₂ + 2e⁻ ⇌ 2Cl⁻ +1.36 2HOCl + 2H⁺ + 2e⁻ ⇌ Cl₂ + 2H₂O +1.64 ClO⁻ + H₂O + 2e⁻ ⇌ Cl⁻ + 2OH⁻ +0.89 Sn⁴⁺ + 2e⁻ ⇌ Sn²⁺ +0.15 Sn²⁺ + 2e⁻ ⇌ Sn -0.14 V²⁺ + 2e⁻ ⇌ V -1.20 V³⁺ + e⁻ ⇌ V²⁺ -0.26 VO²⁺ + 2H⁺ + e⁻ ⇌ V³⁺ + H₂O +0.34 VO₂⁺ + 2H⁺ + e⁻ ⇌ VO²⁺ + H₂O +1.00

1. (a)(i)Standard electrode potentials are measured under standard conditions. Describe the standard conditions used in the Sn⁴⁺/Sn²⁺ half-cell.[1]
2. (a)(ii)Complete the diagram below to show how E° (Sn⁴⁺/Sn²⁺) can be measured experimentally. Your diagram should be fully labelled to identify all apparatus and substances.[3]
3. (a)(iii)Equal volumes of 1.0 mol dm⁻³ Sn²⁺(aq) and 1.0 mol dm⁻³ Cl⁻(aq) are mixed. Use relevant E° values to explain whether a reaction occurs between these two ions.[2]
4. (a)(iv)Equal volumes of 1.0 mol dm⁻³ of Sn²⁺(aq) and acidified 1.0 mol dm⁻³ VO₂⁺(aq) are mixed. Write an equation for the reaction that takes place in the resulting mixture.[2]
5. (b)A solution of SnCl₂(aq) is electrolysed for a measured time using a steady current. A mass of 2.95 g of tin metal is produced at the cathode. Al₂O₃(l) is electrolysed for the same time by the same current. Calculate the mass of aluminium metal produced at the cathode. Give your answer to three significant figures. Show your working. mass of aluminium metal = ................................... g [2][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.