NITROGEN: It occurs mainly as a free element in the air making up about 78% volume of the atmosphere.
Laboratory Preparation of Nitrogen
It is prepared by the decomposition of ammonium dioxinitrate (iii). NB: We combine NaNO 2(aq) AND NH4CL(aq) for the decomposition since direct heating of NH4NO2 is very dangerous.
NaNO2(aq) + NH4CL(aq) → NH4NO2(aq) + NaCL(aq)
NH4NO2(aq) → N2(g) + 2H2O(L)
It can also be obtained from the air.
Industrially, it is obtained in the fractional distillation of air.