Answer: Oxidation state: +3
No of d electrons: 6
Unpaired electrons : 4
Explanation:
Oxidation state: X+6(0)=+3
X=+3
And Co has Atomic number 27
And here it is Co+3 hence [Ar]3d6
Since H2O is weak field ligand no pairing of Electrons involved. Hence there are 4 unpaired electrons. 2 in t2g and 2 in eg orbitals.