On heating compound (A) gives a gas (B) which is a constituent of air. This gas when treated with 3 mol of hydrogen (H_(2)) 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.

On heating compound (A) gives a gas (B) which is a constituent of air.

1.	On heating compound (A) gives a gas (B) which is a constituent of air. This gas when treated with 3 mol of hydrogen (H_(2)) 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.
Answer» Solution :(i) Since gas 'B' on heating with 3 moles of HYDROGEN in presence of a catalyst, gives a gas 'C' which is basic in nature, therefore, 'C' must be ammonia `(NH_(3))` and gas (B) must be `N_(2)` `underset((B))(N_(2))+3H_(2) overset(Delta, "Catalyst")rarr underset("Ammonia (C)")(2 NH_(3))` (ii) Since gas 'B' (i.e., `N_(2)`) is obtained by heating compound (A), therefore, compound (A) must be EITHER ammonium NITRITE or ammonium dichromate `underset((A))(NH_(4))NO_(2) overset(Delta)rarr underset((B))(N_(2))+2H_(2)O or underset((A))((NH_(4))_(2))Cr_(2)O_(7) overset(Delta)rarr underset((B))(N_(2))+Cr_(2)O_(3) + 4 H_(2) O` (iii) Since gas 'C', (i.e., `NH_(3)`) on further oxidation in moist conditions gives compound (D) which is a part of acid rain, therefore, compound (D) must be nitric acid `(HNO_(3))`. `{:(underset((C))(4NH_(3))+5O_(2) overset("Oxidation")rarr 4 NO + 6 H_(2)O),(2 NO + O_(2) rarr 2 NO_(2)"," " "3 NO_(2) + H_(2)O rarr underset((D))(2HNO_(3))+NO):}` Thus, `A = NH_(4)NO_(2) or (NH_(4))_(2) Cr_(2) O_(7), B = N_(2), C = NH_(3) and D = HNO_(3)`.