An aqueous solution of an inorganic salt on treatment with $HCl$ gives a white precipitate. This solution contains

When a salt is treated with sodium hydroxide solution,it gives gas $X$. On passing gas $X$ through reagent $Y$,a brown-coloured precipitate is formed. $X$ and $Y$ respectively,are

Match List-$I$ with List-$II$.

$LIST$-$I$ (Precipitating reagent and conditions)	$LIST$-$II$ (Cation)
$A$. $NH_4Cl + NH_4OH$	$I$. $Mn^{2+}$
$B$. $NH_4OH + (NH_4)_2CO_3$	$II$. $Pb^{2+}$
$C$. $NH_4OH + NH_4Cl + H_2S$ gas	$III$. $Al^{3+}$
$D$. Dilute $HCl$	$IV$. $Sr^{2+}$

Choose the correct answer from the options given below:

$(T)$ imparts violet colour $\xrightarrow{compd.\,(U) + conc.\,H_2SO_4}$ $(V)$ Red gas $\xrightarrow{NaOH + AgNO_3}$ $(W)$ Red ppt. $\xrightarrow{NH_3\,soln.}$ $(X)$
$(W)$ Red ppt. $\xrightarrow{dil.\,HCl}$ $(Y)$ white ppt.
$(U)$ $\xrightarrow[\Delta]{NaOH}$ $(Z)$ gas (gives white fumes with $HCl$)?
$(T)$ sublimes on heating
Identify $(T)$ to $(Z).$

$A$ mixture of two salts is not water-soluble but dissolves completely in dilute hydrochloric acid to form a colourless solution. The mixture could be

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$(NH_4)_2SO_4 + Sr(OH)_2 \longrightarrow SrSO_4 \downarrow + 2NH_3 \uparrow + 2H_2O$