Answer:
1 mol of electron is exchanged. The mol of electrons that is released by the iron, is gained by the silver.
Explanation:
We need to determine the half reactions:
Ag⁺ → Ag
These is the reduction reaction, where Silver decreases the oxidation state. It gained 1 mol of e⁻
Fe²⁺ → Fe³⁺
In this case, iron increases the oxidation state, from +2 to +3. It has released 1 mol of electrons. This is the oxidation reaction.
The complete redox is:
Ag⁺ + 1e⁻ → Ag
Fe²⁺ → Fe³⁺ + 1e⁻
Ag⁺(aq) + 1e⁻ + Fe²⁺(aq) ⇌ Ag(s) + Fe³⁺(aq) + 1e⁻
The electrons will be cancelled.