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

The reagents $NH_4Cl$ and aqueous $NH_3$ will precipitate which of the following ions?

$A$ colorless aqueous solution contains nitrates of two metals,$X$ and $Y$. When it was added to an aqueous solution of $NaCl$,a white precipitate was formed. This precipitate was found to be partly soluble in hot water to give a residue $P$ and a solution $Q$. The residue $P$ was soluble in aqueous $NH_3$ and also in excess sodium thiosulfate. The hot solution $Q$ gave a yellow precipitate with $KI$. The metals $X$ and $Y$,respectively,are

Given below are certain cations. Using inorganic qualitative analysis,arrange them in increasing group number from $0$ to $VI$.
$A$. $Al^{3+}$ $B$. $Cu^{2+}$ $C$. $Ba^{2+}$ $D$. $Co^{2+}$ $E$. $Mg^{2+}$
Choose the correct answer from the options given below.

Which one among the following pairs of ions cannot be separated by $H_2S$ in dilute hydrochloric acid?

Identify ions $A$ and $B$,respectively,based on the following reaction scheme: