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 catalyat gives another gas (C ) which is basic in nature. Gas C on 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_(2)` 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. On oxidation , `NH_(3)` gives `NO_(2)` which is a part of acid rain . So the compounds A to D are as
A `=NH_(4)NO_(2),B=N_(2),C=NH_(3),D=HNO_(3)`
Reactions involved can given , as
"(i)`underset((A))(NH_(4))NO_(2)overset(Delta)tounderset((B))(N_(2))+2H_(2)O`
(ii)`underset((B))(N_(2))+3H_(2)hArrunderset([C])(2NH_(3)`
(iii) `4NH_(3)+5O_(2)overset("Oxidation")to4NO+6H_(2)O`
(iv) `2NO+O_(2)to2NO_(2)`
(v) `3NO_(2)+H_(2)Otounderset((D))(2HNO_(3))+NO`