Describe Charge on the Complex Ion

The charge on the complex ion is equal to the sum of the charges on the metal ion and their ligands.

Example

• [Cu(NH₃)₄]²⁺ can be written as [Cu²⁺(NH₃)₄]²⁺ since NH₃ ligand is neutral.

The sum of the charges on the metal ion and the ligands = +2.

This can be determined as shown below

Charge on the metal ion (Cu²⁺) = +2

Charge on the ligand (NH₃) = 4 × 0 = 0

∴ Net charge on the complex ion = +2 + 0 = +2

• Similarly for [Fe(CN)₆]^4- (or) [Fe²⁺ (CN)₆]^4-

The sum of the charge on the metal ion and the ligand = –4.

Charge on the metal ion (Fe²⁺) = +2

Charge on the ligand (CN-) = 6 × (-1) = –6

∴ Net charge on the complex = +2 – 6 = –4