Electrochemistry

For a \(\mathrm{Ag}-\mathrm{Zn}\) button cell, net reaction is

$$\begin{gathered} \mathrm{Zn}(s)+\mathrm{Ag}_2 \mathrm{O}(s) \longrightarrow \mathrm{ZnO}(s)+2 \mathrm{Ag}(s) \\ \Delta G_f^{\circ}\left(\mathrm{Ag}_2 \mathrm{O}\right)=-11.21 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ \Delta G_f^{\circ}(\mathrm{ZnO})=-318.3 \mathrm{~kJ} \mathrm{~mol}^{-1} \end{gathered}$$

Then, \(E^{\circ}\) cell of the button cell is