Q60 / 180 · AIIMS 2017 · Chemistry
On the basis of standard electrode potential of redox couples given below, find out which of the following is the strongest oxidising agent. $\left(E^{\circ}\right.$ values $: \mathrm{Fe}^{3+}\left|\mathrm{Fe}^{2+}=+0.77 \mathrm{~V} ; \mathrm{I}_{2(s)}\right| \mathrm{I}^{-}=$ $\left.+0.54 \mathrm{~V} ; \mathrm{Cu}^{2+}\left|\mathrm{Cu}=+0.34 \mathrm{~V} ; \mathrm{Ag}^{+}\right| \mathrm{Ag}=+0.80 \mathrm{~V}\right)$
- A$\mathrm{Fe}^{3+}$
- B$\mathrm{I}_{2(s)}$
- C$\mathrm{Cu}^{2+}$
- Correct answerD$\mathrm{Ag}^{+}$
Solution
Higher the electrode potential, better is the oxidising agent. Since, the electrode
potential decreases in the order :
$\mathrm{Ag}^{+}\left|\mathrm{Ag}(+0.80 \mathrm{~V})>\mathrm{Fe}^{3+}\right| \mathrm{Fe}^{2+}(+0.77 \mathrm{~V})>$
$\mathrm{I}_{2(s)}\left|\mathrm{I}^{-}(+0.54 \mathrm{~V})>\mathrm{Cu}^{2+}\right| \mathrm{Cu}(+0.34 \mathrm{~V})$
Hence, $\mathrm{Ag}^{+}$is the strongest oxidising agent.
Hence, the correct answer is option: 'D'.