Give the oxidation state, d orbital occupation and coordination number of the central metal ion in the following complexes

(i) Overall charge balance:

X+3(-2)=-3

X=+3

Oxidation state of Co is +3.

As there are 3 oxolate ion and being bidentate , coordination no. Of complex is 6. So it is octahedral complex.

d orbital occupation: t2g6eg0( oxolate ion is weak field ligand , does not cause pairing of electron as the energy required for pairing of electron is more than CFSE).

(ii) Overall charge balance:

X+balance4(-1)=-2

X=+2

Oxidation state of Co is +2.

As there are 4 fluoride ion  , coordination no. Of complex is 4 i.e. Tetrahedral complex.

d orbital occupation: eg4t2g3( fluoride ion is weak field ligand , does not cause pairing of electron as the energy required for pairing of electron is more than CFSE).

(iii) Overall charge balance:

X+2(-1)+2(0)=+1

X=+3

Oxidation state of Cr is +3

Coordination no. Of complex is 6. (-en is a bidentate ligand) .Octahedral complex.

d orbital complex: t2g3

(iv) Ovearll charge balance:

X+6(0)=+2

X=+2

Oxidation state of Mn is +2.

Coordination no. Of complex is 6. Octahedral complex.

d orbital occupation: t2g3eg2( water is weak field ligand , does not cause pairing of the electron).