Addition of $SnCl_2$ to $HgCl_2$ gives a precipitate of which color?

Identify the inorganic sulphides that are yellow in colour $ : $
$(A)$ $(NH_4)_2S$
$(B)$ $PbS$
$(C)$ $CuS$
$(D)$ $As_2S_3$
$(E)$ $As_2S_5$
Choose the correct answer from the options given below $ : $

$A$ white crystalline substance dissolves in water. On passing $H_2S$ in this solution,a black precipitate is obtained. The black precipitate dissolves completely in hot $HNO_3$. On adding a few drops of conc. $H_2SO_4$ a white precipitate is obtained. This precipitate is that of:

What is formed when calomel $(Hg_2Cl_2)$ reacts with $NH_4OH$?

Which of the following pair of cations can be separated by excess $NaOH$ solution?

The pair$(s)$ of ions where $BOTH$ the ions are precipitated upon passing $H_2S$ gas in the presence of dilute $HCl$,is(are):
$(A) Ba^{2+}, Zn^{2+}$
$(B) Bi^{3+}, Fe^{3+}$
$(C) Cu^{2+}, Pb^{2+}$
$(D) Hg^{2+}, Bi^{3+}$