$Pb(CH_3COO)_2$ gives a precipitate of which color with $H_2S$?

$A$ salt reacts with dilute $HCl$ to produce a gas with a pungent smell and yellow crystals. When tested,the salt gives a green flame. With potassium chromate,the salt gives yellow crystals. Therefore,the salt is.......

Which of these reactions is correct?

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

Yellow ammonium sulphide solution is a suitable reagent for the separation of

Match the List-$I$ with List-$II$ :

Cations	Group reaction
$P \rightarrow Pb^{2+}, Cu^{2+}$	$(i)$ $H_2S$ gas in presence of dilute $HCl$
$Q \rightarrow Al^{3+}, Fe^{3+}$	$(ii)$ $(NH_4)_2CO_3$ in presence of $NH_4OH$
$R \rightarrow Co^{2+}, Ni^{2+}$	$(iii)$ $NH_4OH$ in presence of $NH_4Cl$
$S \rightarrow Ba^{2+}, Ca^{2+}$	$(iv)$ $H_2S$ in presence of $NH_4OH$