Q24 / 180 · COMEDK 2015 · Chemistry
The standard electrode potential for Daniell cell is $1.1 \mathrm{~V}$. What is the standard Gibbs energy for the reaction?
- A$212.3 \mathrm{~kJ} \mathrm{~mol}^{-1}$
- Correct answerB$-2123 \mathrm{~kJ} \mathrm{~mol}^{-1}$
- C$106.15 \mathrm{~kJ} \mathrm{~mol}^{-1}$
- D$-106.15 \mathrm{~kJ} \mathrm{~mol}^{-1}$
Solution
Net reaction occuring in a Daniell cell is
$$
\begin{aligned}
\mathrm{Zn}(s) &+\mathrm{Cu}^{2+}(a q) \longrightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{Cu}(s) \\
\Delta G &=-n F E^{\circ}=-2 \times 96500 \times 1.1 \\
&=-212300 \mathrm{~J} \mathrm{~mol}{ }^{-1}=-212.3 \mathrm{~kJ} \mathrm{~mol}^{-1}
\end{aligned}
$$
Hence, the correct answer is option: 'B'.