Passing $H_2S$ gas into a mixture of $Mn^{2+}, Ni^{2+}, Cu^{2+}$ and $Hg^{2+}$ ions in an acidified aqueous solution precipitates

Which of the following sulfides is yellow in color?

During the qualitative analysis of a salt with cation $y^{2+}$,the addition of a reagent $(X)$ to an alkaline solution of the salt gives a bright red precipitate. The reagent $(X)$ and the cation $(y^{2+})$ present are respectively .... .

Conc. $HNO_3$ is added before proceeding to test for group $III$ members. This is to

What color does lead acetate give with $H_2S$?

On saturating an aqueous solution of $Cu(II)$,$Pb(II)$,and $Zn(II)$ ions with $H_2S$,which of the following will precipitate?