The emf of a galvanic cell constituted with the electrodes Zn2+|Zn(−0.76V) and Fe2+|Fe(−0.41V) is :
The standard reduction potentials, E∘, for the half-reactions are as Zn=Zn2++2e, E∘= + 0.76 V and Fe=Fe2++2e, E∘ = + 0.41 V. The e.m.f. for the cell reaction, Fe2++Zn=Zn2++Fe is