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