Electrolysis and redox
2 marks · EasyDuring the electrolysis of molten sodium iodide (NaI), the following half-equations occur:
For each electrode, state whether the reaction is oxidation or reduction.
(a)[1 mark]
Reaction at the anode:
(b)[1 mark]
Reaction at the cathode:
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Oxidation
(b) Reduction
Common mistakes: Mixing up which electrode is oxidation or reduction.
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Identifies anode reaction as oxidation.
B1 (b) · 1 mark · Identifies cathode reaction as reduction.
Worked solution
a) Anode: Iodide ions lose electrons, so this is oxidation.
b) Cathode: Sodium ions gain electrons, so this is reduction.