Sodium nitroprusside,when added to an alkaline solution of sulphide ions,produces a purple colour due to the formation of:

$A$ 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 ..... .

$A$ white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the aforementioned solution,a white precipitate is obtained which does not dissolve in dilute nitric acid. The anion is:

Which ion's salt solution produces a violet layer when chlorine water and chloroform are added?

$A$ solution of a salt in dilute sulphuric acid imparts a deep blue colour with starch-iodine solution; it confirms the presence of which of the following?

$H_2S$ gas is not evolved when $SO_3^{2-}$ ion reacts with the following reagents.