with other iso-electronic triply bonded systems such as -C ≡ C-, C ≡ O, X-C ≡ N, X-N ≡ C, -C ≡ C-, and -C ≡ N. These groups can act as donor where as dinitrogen cannot. However, it can form complexes with metal (M← N ≡ N) like CO to a less extent The only reaction of nitrogen at room temperature is with lithium forming Li N. With other elements, nitrogen combines only at elevated temperatures.
Group metals and Th forms ionic nitrides. 6Li + N 2Li N Ca N Ca N red hot → B N 2BN bright red hot → Direct reaction with hydrogen gives ammonia. This reaction is favoured by high pressures and at optimum temperature in presence of iron catalyst. This reaction is the basis of Haber’s process for the synthesis of ammonia.
N H NH H kJ mol ∆ = − ⇀ ↽ f With oxygen, nitrogen produces nitrous oxide at high temperatures. Even at K nitrous oxide yield is only . %. 2N 2N O Uses of nitrogen .
Nitrogen is used for the manufacture of ammonia, nitric acid and calcium cyanamide etc. . Liquid nitrogen is used for producing low temperature required in cryosurgery, and so in biological preservation . .
. Ammonia (NH ) Preparation: Ammonia is formed by the hydrolysis of urea. NH CONH +H O 2NH +CO Ammonia is prepared in the laboratory by heating an ammonium salt with a base. NH OH NH H O 2NH Cl CaO CaCl + 2NH + H O XII XII - - - - It can also be prepared by heating a metal nitrides such as magnesium nitride with water.
Mg N 6H O 3Mg(OH) + 2NH It is industrially manufactured by passing nitrogen and hydrogen over iron catalyst (a small amount of K O and Al O is also used to increase the rate of attainment of equilibrium) at K at atm pressure. In the actual process the hydrogen required