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

Options

A. `Mn^(2+)` is more stable with high `3^(nd)` ionisation energy
B. `Mn^(2+)` is bigger in size
C. `Mn^(2+)` has completely filled d-orbitals
D. `Mn^(2+)` does not exist.

Answer

A

Explanation

`Mn^(2+) (3d^(5))` is a statle since it has all half-filled orbitals.
`Fe^(2+) (3d^(6))` is yet to acquire a stable configuration since it has one filled orbital.
Therefore, `Fe^(2+)` ion has a tendency to get oxidised to `Fe^(3+)` ion whereas `Mn^(2+)` ion has no urge to participate in the oxidatioxn reaction.