A white substance (A) on heating with excess of dil HCl gave an offensive smelling gas (B) and a solution (C ). Solution (C ) on treatment with aqueous NH_(3) did not give any precipitate but on treatment with NaOH solution gave a precipitate (D) which dissolves in excess of NaOH solution. (A) on strong heating in air gave a strong smelling gas (E) and a solide (F). Solid (F) dissolved completely in HCl and the solution gave a precipitate with BaCl_(2), in acid solution. Identify A to F and write the chemical equation for various reactions involved.

A white substance (A) on heating with excess of dil HCl gave an offens

1.	A white substance (A) on heating with excess of dil HCl gave an offensive smelling gas (B) and a solution (C ). Solution (C ) on treatment with aqueous NH_(3) did not give any precipitate but on treatment with NaOH solution gave a precipitate (D) which dissolves in excess of NaOH solution. (A) on strong heating in air gave a strong smelling gas (E) and a solide (F). Solid (F) dissolved completely in HCl and the solution gave a precipitate with BaCl_(2), in acid solution. Identify A to F and write the chemical equation for various reactions involved.
Answer» Solution :Solution C gives ppt. with NaOH solution which is soluble in excess of NaOH solution hence the cation should be of the amphoteric metal like Zn or Al. Again solid F is soluble in HCL and gives white precipitate with `BaCl_(2)`. Therefore ANION must be `SO_(4)^(2-)` ion. Nowthe A gives offensive SMELLING gas hence A may be ZnS or `Al_(2)S`. But `Al_(20S_(3)` on hetaing in air does not form `Al_(2)(SO_(4))_(3)` . Chemical reactions are as follows `:` `underset((A))(ZnS)+2HClrarr underset((C ))(ZnCl_(2))+underset((B))(H_(2)S uarr)` `underset((C ))(ZnCl_(2))+2NaOH rarr underset((D))(Zn(OH)_(2)darr)+2NaCl` `Zn(OH)_(2)+2NaOH rarr NA_(2)ZnO_(2)+2H_(2)O` `underset((A))(2ZnS)+3O_(2)rarr underset((F))(2ZnO)+underset((E))(2SO_(2))` `underset((A))(ZnS)+2O_(2)rarrZnSO_(4)(F)` `ZnSO_(4)+BaCl_(2)rarrBaSO_(4)darr +ZnCl_(2)`