Question

With the same d orbital configuration cr + 2 is reducing agent while mn + 3 is an oxidising agent explain why

Answer 1

Cr2+ after loosing an electron converted into Cr3+,d3 is just half filled t2g,more stable.

Mn3+ after gaining an electron converted into Mn2+,which has d5 just half filled d orbitals.

Mn has 2 electrons in 4s orbital thus after loosing 2 e-,it will get d5 easily as e- will added in same d orbital

Cr has configuration..4s1,3d5 ,exceptional case to get stability 1 e- from s jumps to 3d,Now after the removal of e- from d orbital,reorganisation of energy takes place.thus it is difficult to add 1 e- in d orbital.