$A$ solution contains $Cl^{-}$,$I^{-}$,and $SO_{4}^{2-}$ ions. Which of the following ions is capable of precipitating all of the above when added to this solution?

In a solution containing $Hg^{2+}, Cd^{2+}, Sr^{2+}, Fe^{2+},$ and $Cu^{2+}$ ions in $0.3 \, M \, HCl$,which ions will precipitate upon the addition of $H_2S$?

Of the following sulphides,which one is insoluble in dilute acids but soluble in alkalies?

Which ion is detected using Nessler's reagent?

Which of the following cations will give a precipitate with $Na_2C_2O_4$ solution in the presence of acetic acid?

$A$ (Orange color compound) $\xrightarrow{(B) + \text{conc. } H_2SO_4}$ $C$ (Red gas) $\xrightarrow{NaOH + AgNO_3}$ $D$ (Red ppt.) $\xrightarrow{\text{NH}_3 \text{ solution}}$ Yellow solution.
$B$ $\xrightarrow[\Delta]{NaOH}$ $F \uparrow$ (Gives white fumes with $HCl$).
Identify $B$ and $F$ respectively :-