An aqueous solution of gas 'A' gave the following reactions :
(i) It decolourised an acidified `KMnO_(4)` solution.
(ii) On boiling with `H_(2)O_(2)` followed by cooling and then adding an aqueous solution of `BaCl_(2)`, a white precipitate insoluble in dilute HCl was obtained.
(iii) On passing `H_(2)S` through the solution of the gas, white turbidity was obtained. Identify the gas and give equations for steps (i), (ii) and (iii).

Explanation

The data suggests that the gas is 'A' is `SO_(2)`. The equations for the various reactions involved are given :
(i) ` underset(("Violet"))(2KMnO_(4))+underset('A')(5SO_(2))+2H_(2)O to underset(("Colourless"))(K_(2)SO_(4))+underset(("Colourless"))(2MnSO_(4))+2H_(2)SO_(4)`
(ii)` H_(2)O_(2)+underset('A')(SO_(2)) overset("Boil") to H_(2)SO_(4)`
`H_(2)SO_(4)+BaCl_(2) to underset(("white ppt"))(BaSO_(4))+2HCl`
(iii) `underset('A')(SO_(2))+2H_(2)S to underset (("turbidity"))(3S)+2H_(2)O`