$A$ salt on treatment with dil. $HCl$ gives a pungent smelling gas and a yellow precipitate. The salt gives a green flame when tested. The salt solution gives a yellow precipitate with potassium chromate. The salt is:

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Fe(OH)_3 \downarrow + NaOH(\text{excess}) \longrightarrow \text{No reaction}$

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

List-$I$ (Ion)	List-$II$ (Group Number in Cation Analysis)
$A. Co^{2+}$	$I. Group-I$
$B. Mg^{2+}$	$II. Group-III$
$C. Pb^{2+}$	$III. Group-IV$
$D. Al^{3+}$	$IV. Group-VI$

Choose the correct answer from the options given below:

Consider the following sequence of reactions:
$M^{2+}(aq.)$ $\xrightarrow{NH_4Cl(s) + (NH_4)_2CO_3 \, sol.} Q \downarrow$ $\xrightarrow[\text{Followed by addition of } (NH_4)_2C_2O_4]{CH_3COOH} R \downarrow$
Which of the following cations can form precipitate $Q$ but does not form precipitate $R$?

Which reagent is used to distinguish between silver and lead salts?

What precipitate is formed when $SnCl_2$ is added to $HgCl_2$?