Question

$\Delta G^{\circ}$ for the reaction, $Cu^{2+}+Fe \to Fe^{2+}+Cu$ is
(Given : $E^{\circ}_{Cu^{2+}/ Cu}=+0.34\,V$, $E^{\circ}_{Fe^{2+}/ Fe}=-0.44\,V$)

• A. $11.44\, kj$
• B. $180.8 \,kj$
• C. $150.5 \,kj$
• D. $28.5\, kj$

Answer 1

Answer: (C)

$E^{\circ}_{cell}=E^{\circ}_{Cu^{2+}/Cu}-E^{\circ}_{Fe^{2+}/Fe}$
$=0.34\,V-\left(-0.44\right)V=0.78\,V$
$\Delta G^{\circ}=-nFE^{\circ}_{cell}$
$=-2\times96500\times0.78$
$=150540\,J$ or $150.5\,kJ$