Select the correct relation between the electrochemical cell and Gibbs free energy for the following reaction

$Zn(s) + Cu^{2+}(aq) → Zn^{2+}(aq) + Cu(s)$

$Δ_rG=-2FE_{cell}$

The correct answer is Option (2) → $Δ_rG=-2FE_{cell}$

For the reaction

$\text{Zn(s)} + \text{Cu}^{2+}(aq) \rightarrow \text{Zn}^{2+}(aq) + \text{Cu(s)}$

• Zinc is oxidized: $\text{Zn} \rightarrow \text{Zn}^{2+} + 2e^-$
• Copper(II) is reduced: $\text{Cu}^{2+} + 2e^- \rightarrow \text{Cu}$

So, number of electrons transferred (n) = 2.

The general relation is:

$\Delta_r G = -n F E_{\text{cell}}$

Hence,

$\Delta_r G = -2 F E_{\text{cell}}$