Ammonia is manufactured industrially by Haber’s process. Nitrogen from gas is combined with hydrogen derived from natural gas (methane) in the ratio 1:3 giving rise to ammonia. The reaction is reversible and exothermic.

N₂(g)+ 3H₂(g)2NH₃(g)

Fig: Haber’s Process

The optimum conditions for the manufacturing of ammonia are pressure 200×10⁵ Pa, the temperature of 4700 K and iron oxide catalyst with a small amount of Al₂O₃ and K₂O.