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

In salt analysis,$Cl^{-}$,$Br^{-}$,and $I^{-}$ are identified by adding dilute $HNO_3$ followed by $AgNO_3$ solution to the salt solution. Choose the correct statements from the following:
$A$. $Cl^{-}$ gives pale yellow precipitate.
$B$. $Br^{-}$ gives pale yellow precipitate which is partially soluble in $NH_4OH$.
$C$. $I^{-}$ gives yellow precipitate which is insoluble in $NH_4OH$.
$D$. $Cl^{-}$ gives white precipitate which is soluble in $NH_4OH$.
$E$. $I^{-}$ gives yellow precipitate which is insoluble in $NH_4OH$.
Choose the correct answer from the options given below $:-$

$A$ salt gives violet vapours when treated with conc. $H_2SO_4$. It contains

Chromyl chloride vapours are dissolved in $NaOH$ and acetic acid and lead acetate solution is added,then

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

The salt which responds to dilute and concentrated $H_2SO_4$ is