Question

Give the coordination number of the central metal ion in the following complex ions.

a. [Ni(en)2(NH3)2]2+
b. [Fe(en)(ox)Cl2]-
Please explain how you got them too? thanks

Answer 1

a). Coordination no. of
`[Ni(en)_2(NH_3)_2]^2+` = 6

b). Coordination no. of
`[Fe(en)(ox)Cl_2]^2-` = 6

Step-by-step explanation:

Coordination number is defined as number of donar atoms bonded to the central atom of the complex ion.

a). Coordination no. of
`[Ni(en)_2(NH_3)_2]^2+` = 6

en or ethylenediamine is a bidentate ligand.

In bidentate ligand, two atoms directly bonded to the central atom.

NH3 is a unidentate ligand.

So, coordination no.= No. of bidentate ligand x 2 + No. of unidentate ligand

=
`2* 2 + 2 = 6`

b). Coordination no. of
`[Fe(en)(ox)Cl_2]^2-` = 6

Ethylenediamine (en) is a bidentate ligand.

oxalate ion (ox) is also a bidentate ligand.

Cl is a unidentate ligand

So, coordination no.= No. of bidentate ligand x 2 + No. of unidentate ligand

=
`2* 2 + 2 = 6`