Question

Ligand	Number of donor atoms
Cl−	1
F−	1
Br−	1
CO32−	2
CN−	1
gly−	2
EDTA4−	6
NH3	1
H2O	1
CO	1

What is the coordination number for each of the following complexes or compounds?

[Fe(CN)4(CO)2]2−

[Pb(EDTA)]2−

[Zn(NH3)4]2+

Na[Au(CN)2]

Enter the coordination numbers, in the order that the complexes are listed, as four integers separated by commas (e.g., 1,2,3,4).

Answer 1

Answer - 6,6,4,2

The total number of points of attachment to the central atom is termed as coordination number.

[Fe(CN)₄(CO)₂]^2-   has two types of ligands respectively CN^- and CO and both has one donor atom.

Number of CN^- = 4 , Number of CO = 2

Coordination number = 4 + 2= 6

[Pb(EDTA)]^2-   has one tyoe of ligand that is EDTA^4- and it has 6 donor atoms.

Number of EDTA^4-  = 1

Coordination number = 1*6 = 6

[Zn(NH₃)₄]²⁺  has one type of ligand that is NH₃ and it has one donor atom.

Number of NH₃ =4

Coordination number = 4*1 = 3

Na[Au(CN)₂] has one type of ligand that is CN^- and it has one donor atom.

Number of CN^- =2

Coordination number = 2*1 =2