JEE Main 2025 Jan 28 Shift 2, Chemistry Q21: d-Block Elements

Among the given oxides, the strongest oxidising agent is the one whose metal centre has the largest tendency to be reduced. The standard reduction potential $E^{\circ }(M{n}^{3+}/M{n}^{2+})\approx +1.57$ V is markedly more positive than the corresponding values for $T{i}^{2+}$ and $V^{2+}$, so $M{n}_2{O}_3$ (which contains $M{n}^{3+}$) is the strongest oxidant.

$M{n}^{3+}$ has the electronic configuration $[Ar]3d^4$, giving $n=4$ unpaired electrons.

Spin-only magnetic moment: $\mu =\sqrt{n(n+2)}B.M.=\sqrt{4\times 6}=\sqrt{24}\approx 4.9$ B.M.

Nearest integer $=5$ B.M.