The relation between Δ_rG and E_cell is given by ∆_rG = –nFE_cell. ∆_rG is the Gibbs energy of the reaction and E_cell is the cell potential. nF is the amount of charge passed in the cell.

E_cell is an intensive property, it does not depend on the quantity of the substance, while Gibbs energy is extensive and thermodynamic property, which depends on the number of charges. Option (iii) is correct.