The group reagent for the precipitation of group $II$ basic radicals in qualitative analysis is:

$A$ 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.......

When calomel reacts with a solution of $NH_4OH$,which compound is formed?

On treating a solid salt $A$ with dil. $H_2SO_4$ and warming,reddish-brown fumes of gas $B$ are evolved. Addition of $C$ to the salt solution of $A$ followed by freshly prepared starch solution and acidification with acetic acid produces a blue colour. $C$ may contain:

Which radicals are precipitated by $(NH_4)_2CO_3$ in the presence of $NH_4OH$ (alkali)?

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