The incorrect statement in respect of the chromyl chloride test is:

Aqueous solution of a salt $(A)$ forms a dense white precipitate with $BaCl_{2}$ solution. The precipitate dissolves in dilute $HCl$ to produce a gas $(B)$ which decolourises acidified $KMnO_{4}$ solution. $A$ and $B$ respectively are

The $Chromyl$ $Chloride$ test is performed to detect which of the following ions?

$M \text{ (Salt)} + \text{Dil. } HCl \xrightarrow{\text{Warm}} N \uparrow + P \downarrow$. Gas $N$ changes the colour of $FeSO_4$ solution into a yellow solution. Then,salt $M$ in the above reaction is:

$A$ salt,which on heating with conc. $H_2SO_4$ gives violet vapours,is

An unknown salt (anion) reacts with dilute $HCl$ to produce gas $X$ (rotten egg smell). Choose the incorrect option regarding gas $X$.