Question

addition of ammonia to a solution containing Hg2+2 results in a redox process. From the information provided and the concept of oxidation numbers, show this change in mercury.

Answer 1

Redox process is

Hg₂²⁺ + 2 NH3 ...............> [HgNH2]⁺ + NH₄⁺ + Hg

Here

Oxidation number of Hg in Hg₂²⁺ = +1

Oxidation number of Hg in [HgNH2]⁺ = +2

and

Oxidation number of Hg in Hg (l) = 0

that is

Here both oxidation and reduction occurs of  Hg₂²⁺ .

this is an example of disproportionation reaction.