Question

The iron content of foods can be determined by dissolving them in acid (forming Fe3+), reducing the iron(III) to iron(II), and titrating with cerium(IV): Fe2+(aq) + Ce4+(aq) → Fe3+(aq) + Ce3+(aq). Identify the two half-reactions in the above reaction. oxidation half-reaction reduction half-reaction

Answer 1

• Oxidation half-reaction:

Fe²⁺(aq) → Fe³⁺(aq) + 1e⁻

• Reduction half-reaction:

Ce⁴⁺(aq) + 1e⁻ → Ce³⁺(aq)

Step-by-step explanation:

The reaction that takes place is:

• Fe²⁺(aq) + Ce⁴⁺(aq) → Fe³⁺(aq) + Ce³⁺(aq)

The oxidation half-reaction is:

• Fe²⁺(aq) → Fe³⁺(aq) + 1e⁻

It is an oxidation because the oxidation state of Fe increases from 2+ to 3+.

The reduction half-reaction is:

• Ce⁴⁺(aq) + 1e⁻ → Ce³⁺(aq)

It is a reduction because the oxidation state of Ce decreases from 4+ to 3+.