Why are `Mn^(2+)` compounds more stable than `Fe^(2+)` towards oxidation to their +3 state?

Explanation

`Mn^(2+)` is more stable than `Fe^(2+)` towards oxidation to +3 because `Mn^(2+)` has a `d^(5)` electronic configuration, i.e., extra stable half filled d orbital configuration, hence it cannot lose third electron easily whereas `Fe^(2+)` has a `d^(6)` electronic configuration, which has no such extra stability.