$A$ sodium salt gives a white precipitate with $MgCl_2$ only upon heating. What is the anion of the sodium salt?

In the brown ring test,the brown color for $NO_2^-$ and $NO_3^-$ is due to the formation of which complex ion?

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 $:-$

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

$[X] + H_2SO_4 \rightarrow [Y]$ (a colorless gas with a pungent smell). $[Y] + K_2Cr_2O_7 + H_2SO_4 \rightarrow$ green solution. What are $[X]$ and $[Y]$?

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