The correct statement(s) about `Cr^(2+) and Mn^(3+)` is(are)
[Atomic number of `Cr=24 and Mn=25`]

Options

A. `Cr^(2+)` is a reducing agent
B. `Mn^(3+0` is an oxidizing agent
C. Both `Cr^(2+)` and `Mn^(3+)` exhibit `d^(4)`electronic configuration
D. When `Cr^(2+)` is used as a reducing agent, the chromium ion attains `d^(5)` configuration

Explanation

(a) `Cr^(2+)` is a reducing agent as it gets oxidizd to `Cr^(3+) ( 3d^(3)` or `t_(2g)^(3)` which is a stable half-filled configuration)
(b) `Mn^(3+)` is an oxidizing agent as it gets reduced to `Mn^(2+)( 3d^(5)` which is more stable half-filled configuration ).
(c ) `Cr( 24) = 3d^(4) 4s^(2) :. Cr^(2+ ) = 3d^(4)`
`Mn(25) = 3d^(5) 4s^(2) :. Mn^(3+) = 3d^(4)`
Thus, both `Cr^(2+)` and `Mn^(3+)` have `d^(4)` electronic configuration .
(d) When `Cr^(2+)` is used as a reducing agent, it is oxidized to `Cr^(3+)` which has `d^(3)` and not `d^(5)` configuration.