The $E^{\circ}$ value for the $\mathrm{Mn}^{3+} / \mathrm{Mn}^{2+}$ couple is more positive than tha

Question

The $E^{\circ}$ value for the $\mathrm{Mn}^{3+} / \mathrm{Mn}^{2+}$ couple is more positive than that of $\mathrm{Cr}^{3+} / \mathrm{Cr}^{2+}$ or $\mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}$ due to change of

Professor PC Thomas Classes · Answer

(c) : ${ }_{25} \mathrm{Mn} \Rightarrow[\mathrm{Ar}] 3 d^5 4 s^2$ \ $ \begin{aligned} & \mathrm{Mn}^{3+} \Rightarrow[\mathrm{Ar}] 3 d^4 \ & \mathrm{Mn}^{2+} \Rightarrow[\mathrm{Ar}] 3 d^5 \end{aligned} $ As $d^5$ is a half filled electronic configuration, it is highly stable configuration. Thus, $\mathrm{Mn}^{3+}$ has high tendency to get reduced to $\mathrm{Mn}^{2+}$