Working on a practice question for finals so I really want to understand how this works:

Question

What is the coordination number of mercury in K2[HgI4]?

I say that mercury's coordination number is 4 because I^- is a monodentate ligand.

Does the potassium affect the coordination number at all? Thanks for any insight.

Answer 1

You are right. K has no effect on the coordination number; it simply is the other half of the "ionic" bond between K^+ and HgI4^2-

Answer 2

Thanks so much :)