Under what condition is ECell = 0 or ΔrG = 0?
Electrolysis happens when a redox reaction occurs. Like all reactions, redox reaction to moves towards equilibrium. At equilibrium condition, the cell has discharged completely, and cell potential drops to zero.
∆rG= -nF E cell =0
Where ∆rG° is the standard Gibbs energy of the reaction
n is the number of electrons transferred
F is Faraday’s constant and
E°cell is the standard electrode potential of a cell