$AgNO_3$ gives a red precipitate with:

$A$ mixture is heated with dilute $H_2SO_4$ and the lead acetate paper turns black due to the evolved gases. The mixture contains:

Which statement is not true with respect to the nitrate ion test?

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

When $BaCl_2$ is added to a clear solution of compound $(X)$,a heavy white precipitate is formed,which is insoluble in dilute $HCl$. What is compound $(X)$?

On treating a compound with warm dil. $H_{2}SO_{4}$,gas $X$ is evolved which turns $K_{2}Cr_{2}O_{7}$ paper acidified with dil. $H_{2}SO_{4}$ to a green compound $Y$. $X$ and $Y$ respectively are