Nitric acid is the most important oxyacid  formed y nitrogen .It is one of the major industial
Channel: Doubtnut
Date: 26/04/2020

Nitric acid is the most important oxyacid  formed y nitrogen .It is one of the major industial chemicl and is widely used. Nitric acid is manufactured by the catalytic oxidation of ammonia in what is known as OSTWALD PROCESS which can be represented by the sequenve of reactions shown below:   `4NH_(3)(g) +5O_(2)(g) underset("Catalyst")overset(Pt//Rh)rarr 4NO(g)+6H_(2)O(g) "   "...(i)`   `2NO(f) + O_(2)(g) overset(1120 K) rarr 2NO_(2)(g)"   "...(ii)`   `3NO_(2)(g)+H_(2)O(l) rarr 2HNO_(3)(aq)+NO(g)"    "...(iii)`   The aqueous nitric acid obtained by this method can be concentrated by distillation to ~ 68.5 % by weight . Further concentrated to 98% acid can be achieved by dehyration with concentrated sulphuric acid. If 170 kg of `NH_(3)`  is heated in excess of oxygen then  the volume fo `H_(2)O(l)`  produced in 1st reaction at STP si , `(rho_(H_(2))O=1 gm//ml))`