Coordination Compounds Part 2

[Co(NH3)6]Cl2
Co2+:[Ar]3d74s04p0
For this complex Δ0< P.E., so pairing of electron does not take place.
sp3d2 hybridisation
Total 3 unpaired electrons are present.
[Co(NH3)6]Cl3
Co3+:[Ar]3d64s04p0
d2sp3 hybridisation
NH3 acts as SFL because Δ0>P.E
So here all electrons becomes paired.