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

A. [Fe (gly) 2 (H2O) 2]+

B. [Cr (EDTA) ]-

C. [Pt (NH3) 4]2+

D. [Ag (NH3) 2]NO3

a. 4, b. 6, c. 4, d. 2

Explanation:

The coordination number (CN) of a complex of a compound is the number of bonds that a metallic ion does with the binders, which can be equal or not.

a. The metallic ion is the iron (Fe), and it's bonded to 2 gly and 2 H2O, thus, CN = 4.

b. EDTA is a hexadentate molecule, thus, it forms 6 bonds with the metal Cr, and CN = 6.

c. The metal is Pt, which has 4 bonds with NH3, thus CN = 4.

d. The metal is Ag, which forms 2 bonds with NH3. NO3 is bonded with the structure and not with the metal. Thus, CN = 2.