Chemistry - Electrochemistry Question with Solution | TestHub

${\mathrm{E}}_{\mathrm{C}{\mathrm{r}}^{3+}/\mathrm{C}{\mathrm{r}}^{2+}}^{\mathrm{o}}=-0.41\mathrm{V};{\mathrm{E}}_{\mathrm{M}{\mathrm{n}}^{3+}/\mathrm{M}{\mathrm{n}}^{2+}}^{\mathrm{o}}=+1.57\mathrm{V};{\mathrm{E}}_{\mathrm{F}{\mathrm{e}}^{3+}/\mathrm{F}{\mathrm{e}}^{2+}}^{\mathrm{o}}=+0.77\mathrm{V};{\mathrm{E}}_{\mathrm{C}{\mathrm{o}}^{3+}/\mathrm{C}{\mathrm{o}}^{2+}}^{\mathrm{o}}=+1.97\mathrm{V}$

Standard reduction potential (SRP) value normally increases from left to right in the period of d-block elements. Some SRP values are exceptionally higher due to stability of the product ion. For e.g.,

${\mathrm{E}}_{\mathrm{M}{\mathrm{n}}^{3+}/\mathrm{M}{\mathrm{n}}^{2+}}^{\mathrm{o}}=+1.57\mathrm{V};{\mathrm{E}}_{\mathrm{C}{\mathrm{o}}^{3+}/\mathrm{C}{\mathrm{o}}^{2+}}^{\mathrm{o}}=+1.97\mathrm{V}$.