Chemistry - Electrochemistry Question with Solution | TestHub

The ${\mathrm{E}}_{{\mathrm{M}}^{3+}/{\mathrm{M}}^{2+}}^{\mathrm{o}}$ values for $\mathrm{Cr},\mathrm{Mn},\mathrm{Fe}$ and Co are $-0.41,+1.57,+0.77$ and +1.97 V respectively. For which one of these metals the change in oxidation state from +2 to +3 is easiest?