Question

A solution of a metal ion when treated with KI gives a red precipitate which dissolves in excess KI to give a colourless solution. Moreover, the solution of metal ion on treatment with a solution of cobalt (II) thiocyanate gives rise to a deep blue crystalline precipitate. The metal ion is (a) Pb²⁺(b) Hg²⁺(c) Cu²⁺(d)Co²⁺

Answer 1

12. (b) Hg2+ + 2KI ? HgI2 ?+2K+

(red ppt)

HgI2 + 2KI ? K2 [HgI4]

Hg2+ + Co2+ + 4SCN- ? Co[Hg(SCN)4]?

(deep blue crystalline)

Answer 2

Hey friend, I have tried to explain it in the shortest way so that you can get it easily without any confusion.

I hope it helps