An inorganic sodium salt (A) gives two colourless gases (B) and (C ) leaving a residue (D). B turns white copper sulphate blue, while C turns lime water milky and then colourless. The residue solid (D) when heated strongly gives substance (E) and (F). E gives white precipitate with `BaCl_(2)`. F when treated with dil. HCl gives a gas (G), which when passed through a solution of `SO_(2)` gives a yellow precipitate due to (H). Identify A to H with proper reasoning.

Explanation

`A=NaHSO_(3),B=H_(2)O,C=SO_(2),D=Na_(2)SO_(3),E=Na_(2)SO_(4),F=Na_(2)S,G=H_(2)S,H=S`