Question

Out of $C{r}^{3+}$ and $M{n}^{3+}$, which is stronger oxidising agent and why?

Answer 1

The electronic configuration of Cr${}^{3+}$ and Mn ${}^{3+}$

Cr${}^{3+}$- [Ar}3d${}^{3}4s^0$.

Mn${}^{3+}$ - [Ar}3d${}^{4}4s^0$.

So, when Cr${}^{3+}$ and Mn${}^{3+}$ act as oxidising agent, they get reduced to Cr${}^{2+}$ and Mn${}^{2+}$ respectively. The electronic configuration attained are 3d${}^4$ and 3d${}^5$ respectively.

Since Mn${}^{2+}$ has half filled stable configuration so it is a stronger oxidising agent.