On heating compound (A) gives a gas (B) which is a constituent of air. This gas when treated with 3 moles of hydrogen (H2) in the presence of a catalyst 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.




The main constituents of air are nitrogen (78%) and oxygen (21%). Only N2 reacts with three moles of H2 in the presence of a catalyst to give NH3 (ammonia) which is a gas having basic nature. On oxidation, NH3 gives NO2 which Is a part of acid rain. So, the compounds A to D are as

A = NH4NO2 ;     B = N2 ;      C = NH3 ;     D = HNO3

 Reactions involved can be given, as


i NH4NO2 (A)N2(B) + 2H2O(ii) N2[B] + 3H2  2NH3[C](iii) 4NH3 + 5O2 Oxidation 4NO + 6H2O (iv) 2NO+ O2  2NO2 (v) 3NO2 + H2O  2HNO3(D) + NO