On heating compound A gives a gas B which is a constituent of air. This gas when treated with 3 moles of hydrogen `(H_(2))` in the presence of a catalyst gives another gas C which is basic in nature. Gas Con further, oxidation in moist condition gives a compound D which is a part of acid rain. Identify compounds A to D and also give necessary equations of all the steps involved.

Explanation

The main constituents of air are nitrogen (78%) and oxygen (21%). Only N, reacts with three moles of `H_(2)` in the presence of a catalyst to give `NH_(3)` (ammonia) which is a gas having basic nature hence, compound C is `NH_(3)`, and B is `N_(2)` . On oxidation, `NH_(3)`, gives `NO_(2)`, which in moist conditions forms `HNO_(3)`, a part of acid rain. So, the compound D is `HNO_(3)`. Since, `N_(2)`, i.e. Bis obtained by heating compound A, therefore A must be a nitrite. Thus, A is ammonium nitrite, `NH_(4)NO_(2)`. Hence, the compounds A to D are:
`A = NH_(4)NO_(2), B = N_(2), C = NH_(3), D =HNO_(3)`
Reactions involved can be given as
(i) `underset((A))(NH_(4)NO_(2)) overset(Delta)(rarr)underset((B))(N_(2))+2H_(2)O`
(ii) `underset((B))(N_(2))+3H_(2)overset(Delta)underset("Catalyst")(rarr)underset((C))(2NH_(3))`
(iii) `underset((C))(4NH_(3))+5O_(2)overset("Oxidation")(rarr)4NO+6H_(2)O`
(iv) `2NO +O_(2) rarr 2NO_(2)`
(v) `3 NO_(2)+H_(2)O rarr underset((D))(2HNO_(3)) + NO`