Answer
(a) -0.26 V
(b) -0.13 V
(c) -0.065 V
When number of electrons exchanged increases, magnitude of $E^{\circ}$ value decreases.
Work Step by Step
$\Delta G^{\circ}=-nFE^{\circ}_{cell}$
$\implies E^{\circ}_{cell}=-\frac{\Delta G^{\circ}}{nF}$
(a) When $n=1$, $E^{\circ}=-\frac{25000\,J}{(1)(96485\,C)}=-0.26\,V$
(b) When $n=2$, $E^{\circ}=-\frac{25000\,J}{(2)(96485\,C)}=-0.13\,V$
(c) When $n=4$, $E^{\circ}=-\frac{25000\,J}{(4)(96485\,C)}=-0.065\,V$
When number of electrons exchanged increases, magnitude of $E^{\circ}$ value decreases.
