Formation of $Na_4[Fe(CN)_5NOS]$,a purple coloured complex formed by addition of sodium nitroprusside in sodium carbonate extract of salt indicates the presence of $:$

$A$ brown ring appears in the test for

Which anion of a sodium salt gives a white precipitate upon heating with a magnesium salt?

The brown ring test is used to detect the presence of which ion?

$A$ white precipitate was formed when $BaCl_{2}$ was added to the water extract of an inorganic salt. Further,a gas $X$ with a characteristic odour was released when the formed white precipitate was dissolved in dilute $HCl$. The anion present in the inorganic salt is ..... .

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