The electrode reactions for molten iron(III) chloride are:
cathode: Fe3++3e−→Fe\mathrm{Fe^{3+} + 3e^{-} \rightarrow Fe}Fe3++3e−→Fe
anode: 2Cl−→Cl2+2e−\mathrm{2Cl^{-} \rightarrow Cl_{2} + 2e^{-}}2Cl−→Cl2+2e−
When four iron atoms are deposited at the cathode, how many chlorine molecules form at the anode?
2
4
6
12
98 exam-style questions on OCR GCSE Chemistry 3.4 Electrolysis, covering 3.4.1 Products formed at the electrodes in electrolysis and 3.4.2 The technique of electrolysis. Each one has a worked solution and a mark scheme showing where the marks go.