Because Cr ki oxidation state +2 to +6 and mn ox.state is -3 to +7 .. it's sufficent for your question...ok

Reduction of Cr2+ and Oxidation of Mn3+

Explanation:

Electronic Configuration:
- Both Cr2+ and Mn3+ ions have a d4 electronic configuration.
- Cr2+ has the electronic configuration [Ar] 3d4 whereas Mn3+ has the electronic configuration [Ar] 3d4.

Stability of oxidation states:
- Chromium (Cr) tends to exhibit a stable +3 oxidation state due to half-filled d orbitals, which increases stability.
- Manganese (Mn) can exhibit multiple oxidation states due to the presence of partially filled d orbitals, resulting in Mn3+ being a relatively stable oxidation state.

Reduction potential:
- The reduction potential of Cr2+ to Cr3+ is higher compared to the oxidation potential of Mn3+ to Mn4+.
- This difference in reduction and oxidation potentials leads to the reduction of Cr2+ and oxidation of Mn3+ in certain chemical reactions.

Overall reaction:
- In some redox reactions, Cr2+ can act as a reducing agent, losing electrons to form Cr3+.
- Conversely, Mn3+ can act as an oxidizing agent, gaining electrons to form Mn4+.

In conclusion, although both Cr2+ and Mn3+ have a d4 electronic configuration, the stability of oxidation states, reduction potentials, and overall chemical reactions determine why Cr2+ is reducing and Mn3+ is oxidizing in certain chemical reactions.