Question

Passing $H_{2}S$ gas into a mixture of ${Mn}^{2+},{Ni}^{2+},{Cu}^{2+},{Hg}^{2+}$ ions in acidified aqueous solution precipitates:

• A. $CuS$ and $HgS$
• B. $MnS$ and $CuS$
• C. $MnS$ and $NiS$
• D. $NiS$ and $HgS$

Answer 1

The correct option is A $CuS$ and $HgS$

${Cu}^{2+}$ and ${Hg}^{2+}$ lie in IInd group of qualitative analysis $H_{2}S$ in acid medium is reagent for it.
$HCl\to H^{+}+{Cl}^{-}$
$H_{2}S\leftrightharpoons 2H^{+}+S^{2-}$