`Cr^(2+)` is a strong reducing agent whereas `Mn^(3+)`with the same `d^4` configuration, is an oxidising agent.

Explanation

`Cr^(2+)` is a reducing agent because it can lose alection to form `Cr^(3+)` which has stable `3d^(3)` configuration (as it has hal filled ing level). On the other hand, the change from `Mn^(3+)" to "Mn^(2+)` results in the half-filled of `d^5` configuration which has extra stability. Thus, it behayee As an oxidising agent.