For a reaction to be spontaneous, Ecell ∘ must be positive. - For, FeSO4(aq)+Zn(s)→ZnSO4(aq)+Fe(s) Ecell ∘=Ecathode ∘−Eanode ∘ =−0.44V−(−0.76V) =0.32V - For, 2CuSO4(aq)+2Ag(s)→2Cu(s)+Ag2SO4(aq) Ecell ∘=0.34V−0.80V =−0.46V - For, CuSO4(aq)+Zn(s)→ZnSO4(aq)+Cu(s) Ecell∘=0.34V−(−0.76V) =1.1V - For, CuSO4(aq)+Fe(s)→FeSO4(aq)+Cu(s) Ecell ∘=0.80V−(−0.44V) =1.24V