D And F Block Elements

The \(\mathrm{E}^{\circ}\) 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