Chemistry - Complete d-block Question with Solution | TestHub

The stability of oxidation states in aqueous solution is determined by electrode potentials. For Cr, the $E^{\circ }$ for ${\mathrm{Cr}}^{3+}/{\mathrm{Cr}}^{2+}$ is $-0.41\mathrm{V}$, indicating ${\mathrm{Cr}}^{3+}$ is more stable than ${\mathrm{Cr}}^{2+}$. This is due to the $t_{2g}^3$ configuration of ${\mathrm{Cr}}^{3+}$ which provides extra stability.

The final answer is $\boxed{C}$