Chemistry · Oct / Nov 2017 · Paper 12 · Question 16

Magnesium can be produced by electrolysis of molten magnesium chloride, MgCl2. What are the equations for the reactions that occur at the positive electrode and at the negative electrode?

1. Apositive electrode: 2Cl– → Cl2 + 2e–; negative electrode: 2H+ + 2e– → H2
2. Bpositive electrode: Cl2 + 2e– → 2Cl–; negative electrode: Mg2+ + 2e– → Mg
3. Cpositive electrode: 2Cl– → Cl2 + 2e–; negative electrode: Mg2+ + 2e– → Mg
4. Dpositive electrode: 2Cl– → Cl2 + 2e–; negative electrode: Mg2+ + 2e– → 2Mg

As printed in the paper