Question icon
Grade 11Inorganic Chemistry

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. Pb^2+
b. Hg^2+
c. Cu^2+
d. Co^2+

Profile image of Radhika Batra
12 Years agoGrade 11
Answers icon

1 Answer

Profile image of Navjyot Kalra
12 Years ago

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

(red ppt)

HgI2 + 2KI ? K2 [HgI4]

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

(deep blue crystalline)