Which is more stable? `Fe^(3+)` or `Fe^(2+)` - explain.

Explanation

Fe (Z -26) `Fe to Fe^(2+) + 2e^(-)`
`Fe to Fe^(3+) + 3e^(-)`
`Fe^(2+)` [Number of electrons 24)
Electronic configuration = [Ar]`3d^(6)`
`Fe^(3+)` [Number of electrons 23)
Electronic configuration = [Ar]`3d^(5)`
Among `Fe^(3+)` and `Fe^(2+), Fe^(3+)` is more stable due to half filled d-orbital. This can be explained by Aufbau principle. Half filled and completely filled d-orbitals are more stable than partially filled d-orbitals. So `Fe^(3+)` is more stable than `Fe^(2+)`.