Question

Calculate the charge number of the complex ion:

[Pt(NH₃)₂Cl₂]

Answer 1

Complex: [Pt(NH₃)₂Cl₂]

Let the oxidation number of Pt be x.

NH₃ (neutral ligand) has a charge of 0 each.

There are 2 NH₃ ions, so total charge from ligands = 2 × (0) = 0.

Cl⁻ is a monodentate anionic ligand that has a charge of −1 each.

There are 2Cl⁻ ions = −2

Overall charge on the complex = +1

x + 2(0) + 2(−1) = 0

x − 2 = 0

x = +2

The oxidation number of Pt is +2.