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

Explanation

E.C of `Mn^(2+) ` is `3d^5` which is half filled and hence stable. Third ionisation enthalpy is very high i.e. 3rd electron cannot be lost easily. In `Fe^(2+)` E.C. is `3d^6` . So it can loose one electron easily to give stable electronic configuration `(3d^5)`.