Q76 / 200 · NEET 2006 · Chemistry
A hypothetical electrochemical cell is show below
$\stackrel{\Theta}{\mathrm{A}}\left|\mathrm{A}^{+}(x \mathrm{M}) \| \mathrm{B}^{+}(y \mathrm{M})\right| \stackrel{\oplus}{\mathrm{B}}$
The emf measured is $+0.20 \mathrm{~V}$. The cell reaction is:
- Correct answerA$\mathrm{A}+\mathrm{B}^{+} \rightarrow \mathrm{A}^{+}+\mathrm{B}$
- B$\mathrm{A}^{+}+\mathrm{B} \rightarrow \mathrm{A}+\mathrm{B}^{+}$
- C$\mathrm{A}^{+}+e^{-} \rightarrow \mathrm{A}$; $\mathrm{B}^{+}+e^{-} \rightarrow \mathrm{B}$
- Dthe cell reaction cannot be predicted
Solution
$\mathrm{A} / \mathrm{A}^{+}(x \mathrm{M}) \| \mathrm{B}^{+}(y \mathrm{M}) / \mathrm{B}$
$$
\mathrm{E}_{\text {cell }}=+0.20 \mathrm{~V} \therefore \Delta \mathrm{G}=-v e
$$
Therefore given cell reaction is spontaneous
At Anode $\quad \mathrm{A} \rightarrow \mathrm{A}^{+}+e^{-}$
\begin{array}{ll} At Cathode & \mathrm{B}^{+}+e^{-} \rightarrow \mathrm{B} \\ \hline Cell reaction & \mathrm{A}+\mathrm{B}^{+} \rightarrow \mathrm{A}^{+}+\mathrm{B} \end{array}
Hence, the correct answer is option: 'A'.