A solutionf 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 ions is

Options

A. `Pb^(2+)`
B. `Hg^(2+)`
C. `Cu^(2+)`
D. `Co^(2+)`

Answer

b,c

Explanation

`Hg^(2+) + 2I^(Theta) rarr HgI_(2) darr `(Scarlet red precipitate )
`HgI_(2) + 2I^(theta) rarr [HgI_(4)]^(2+)`
`Hg^(2+) + Co(SCN)_(2) rarr underset("Deep blue crystalaline")(Hg(SCN)_(2)) + Co^(2+)`