The solution of a chemical compound $X$ reacts with $AgNO_3$ solution to form a white precipitate of $Y$,which dissolves in $NH_4OH$ to give a complex $Z$. When $Z$ is treated with dilute $HNO_3$,$Y$ reappears. The chemical compound $X$ can be:

Which of the statement is incorrect for the given paragraph?
Simple salt $\xrightarrow{\text{Flame test}}$ Golden yellow flame
Simple salt $\xrightarrow[MnO_2]{Conc. H_2SO_4} (X)$ Yellowish green gas
Simple salt $\xrightarrow{AgNO_3} (Z)$ White ppt. (Insoluble in dil. $HNO_3$)
Simple salt $\xrightarrow[Conc. H_2SO_4]{K_2Cr_2O_7} (Y)$ Reddish brown vapour

Which of the following will not produce a precipitate with $AgNO_3$ solution?

On addition of conc. $H_2SO_4$ to a chloride salt,colourless fumes are evolved,but in the case of an iodide salt,violet fumes are observed. This is because:

Which of the following substances releases $SO_2$ gas upon reaction with dilute $H_2SO_4$?

$A$ reagent consisting of $1$-naphthylamine and sulphanilic acid in acetic acid is used for the detection of: