Chemistry - Electrochemistry Question with Solution | TestHub

The standard cell potential is given by the difference between the standard reduction potentials of the cathode and the anode.

$E_{\text{cell}}^{\circ }=E_{\text{cathode}}^{\circ }-E_{\text{anode}}^{\circ }$

From the given cell representation, zinc acts as the anode (oxidation half-cell) and the calomel electrode acts as the cathode (reduction half-cell).

$E_{\text{cell}}^{\circ }=E_{\text{calomel}}^{\circ }-E_{\text{Zn}}^{\circ }$

Substituting the given values:

$1.007=0.242-E_{\text{Zn}}^{\circ }$

$E_{\text{Zn}}^{\circ }=0.242-1.007$

$E_{\text{Zn}}^{\circ }=-0.765\text{ V}$

Answer: $-0.765\mathrm{V}$