Question

$\Delta_{r}G^{\circ}$ for the cell with the cell reaction :
$Zn_{\left(s\right)}+Ag_{2}O_{\left(s\right)}+H_{2}O_{\left(l\right)} \to Zn^{2+}_{\left(aq\right)}+2Ag_{\left(s\right)}+2OH^{-}_{\left(aq\right)}$
$\left[E^{\circ}_{Ag_2\,O/Ag}=0.344\,V, E^{\circ}_{Zn^{2+}/Zn}=-0.76\,V\right]$

• A. $2.13\times10^{5}\,J\,mol^{-1}$
• B. $-2.13\times10^{5}\,J\,mol^{-1}$
• C. $1.06\times10^{5}\,J\,mol^{-1}$
• D. $-1.06\times10^{5}\,J\,mol^{-1}$

Answer 1

Answer: (B)

$E^{\circ}_{cell}=E^{\circ}_{Ag_2\,O/Ag}-E^{\circ}_{Zn^{2+}/Zn}$
$=0.344-\left(-0.76\right)=1.104\,V$
$\Delta G^{\circ}=-nFE^{\circ}_{cell}=-2\times96500\times1.104$
$=-2.13\times10^{5}\,J\,mol^{-1}$