The overpotential is the difference between the applied voltage and the reduction potential for the reaction. In this case, the reduction potential for the oxidation of silver ions to silver metal at a silver electrode is +0.80 V, and the applied voltage is +1.00 V.Overpotential = Applied voltage - Reduction potentialOverpotential = +1.00 V - +0.80 V Overpotential = +0.20 VThe overpotential required for the oxidation of silver ions to silver metal at a silver electrode is +0.20 V.