Emf of the cell Zn /Zn+2//Cu+2/Cu will be highest when
Ecell = Ecello−0.0591nlog[Products]Reactants
Anode−Zn → Zn+2+2e−
Cathode Cu+2 +2e-→Cu
Zn + Cu+2 → Zn+2 +Cu
E0cell is a constant
Ecell∝ −logZn+2Cu+2
Lesser theZn+2Cu+2,higher will be the Ecell
∴ (2) is correct