Question

Calculate the maximum work that can be obtained from the cell
$ Zn\left|Zn^{2+}\left(1M\right)\right|\left|Ag^{+}\left(1M\right)\right|Ag $
where, $ E^{\circ}_{Zn}=-0.76\,V $ and $ E^{\circ}_{Ag}=0.8\,V $

• A. 301.080 kJ
• B. 201.830 kJ
• C. 112.830 kJ
• D. 213.630 kJ

Answer 1

Answer: (A)

Electrical work done
$= \Delta_r G^{\circ} = -n FE^{\circ}$
$E^{\circ} = E^{\circ}_{\text{cathode}} - E^{\circ}_{\text{anode}}$
$ = 0.80 - (-0.76)$
$ = 1.56\,V$
$\Delta G^{\circ} = -2 \times 96500 \times 1.56$
$ = -301080 \,Jmol^{-1}$
$ = -301.080 \,kJ\,mol^{-1}$