Question

Calculate the overpotential (in millivolts) for the reduction of Cu2+ to Cu on a copper electrode at 25°C, given that the standard reduction potential of Cu2+ to Cu is +0.34 V and the actual voltage is 0.32 V.

Answer 1

Overpotential is the difference between the actual potential  voltage  and the standard potential  voltage  for a given redox reaction. In this case, we are given the standard reduction potential of Cu2+ to Cu as +0.34 V and the actual voltage as 0.32 V.To calculate the overpotential, we can use the following formula:Overpotential = Actual potential - Standard potentialOverpotential = 0.32 V - 0.34 VOverpotential = -0.02 VTo convert the overpotential from volts to millivolts, we can multiply by 1000:Overpotential = -0.02 V  1000Overpotential = -20 mVThe overpotential for the reduction of Cu2+ to Cu on a copper electrode at 25C is -20 millivolts.