Question

A colorless solution is known to contain one of these ions. Which ion is present if adding dilute HCl produces a white precipitate that dissolves when the solution is warmed?
(A) Ag+
(B) Cu2+
(C) Hg22+(D) Pb2+

Answer 1

Answer:

The correct answer is option D.

Explanation:

All the cations given belong to the group-1 cation and will give precipitate of their respective chlorides when HCl is added to their aqueous solution.

$Ag^+(aq)+HCl(aq)\rightarrow AgCl(s)+H^+(aq)$

$Cu^{2+}+(aq)+2HCl(aq)\rightarrow CuCl_2(s)+2H^+(aq)$

$Hg_{2}^{2+}+(aq)+2HCl(aq)\rightarrow Hg_2Cl_2(s)+2H^+(aq)$

$Pb^{2+}+(aq)+2HCl(aq)\rightarrow PbCl_2(s)+2H^+(aq)$

All the precipitates are insoluble in cold water but out of all these only lead(II) chloride is soluble in warm water.