Question

Which of the following reagents gives white precipitate with `Hg(NO_(3))_(2)` solution?
A. Cobalt (II) thiocyanate
B. Tin (II) chloride (excess)
C. ammonia solution
D. Potassium cyanide solution

Answer 1

Correct Answer - C
(A)`Hg^(2+)+Co^(2+)+4SCN^(-)toCo[Hg(SCN)_(4)darr` (deep blue),
(B)`2Hg^(2+)+Sn^(2+)+2Cl^(-)toHg_(2)Cl_(2) darr ("white")+Sn^(4+),Hg_(2)Cl_(2)+Sn^(2+) to Hg darr ("black") + Sn^(4) +2Cl^(-)`
( C)`2Hg^(2+)+NO_(3)^(-)+4NH_(3)+H_(2)OtoHgO.Hg(NH_(2))NO_(3) darr` (white)
(D)`KCN` no effect i.e. no reaction.