Question

Calculate the charge number of the complex ion furnished by the complex K₂[HgI₄].

Answer 1

The formula of the complex salt is K₂[HgI₄].

This indicates the complex ion is:

[HgI₄]^x−

Let the charge on the complex ion [HgI₄] be x⁻.

Potassium ions (K⁺) are the counter ions, and there are 2 K⁺ ions in the formula, so:

2(+1) + (x) = 0

2 + x = 0

x = −2

The charge number of the complex ion [HgI₄]²⁻ is −2.

Hence charge ion is [HgI₄]²⁻.