Electrochemistry 1 Question 8
8. Given, $E_{\mathrm{Cl}{2} / \mathrm{Cl}^{-}}^{\circ}=1.36 \mathrm{~V}, E{\mathrm{Cr}^{3+} / \mathrm{Cr}}^{\circ}=-0.74 \mathrm{~V}$
$E_{\mathrm{Cr}{2} \mathrm{O}{7}^{2-} / \mathrm{Cr}^{3+}}^{\circ}=1.33 \mathrm{~V}, E_{\mathrm{MnO}_{4}^{-} / \mathrm{Mn}^{2+}}^{\circ}=1.51 \mathrm{~V}$
Among the following, the strongest reducing agent is
(2017 Main)
(a) $\mathrm{Cr}$
(b) $\mathrm{Mn}^{2+}$
(c) $\mathrm{Cr}^{3+}$
(d) $\mathrm{Cl}^{-}$
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Answer:
Correct Answer: 8. (b)
(a)
Solution:
- The substances which have lower reduction potentials are stronger reducing agents. Therefore, $\mathrm{Cr}\left(E_{\mathrm{Cr}^{3+} / \mathrm{Cr}}^{\circ}=-0.74 \mathrm{~V}\right)$ is the strongest reducing agent among all the other given options.
