Ammonia is one of the most important compounds needed to make syntheticA material made by a chemical process, not naturally occurring.fertiliserA nutrient added to the soil to increase the soil fertility..
Ammonia is made using the Haber processThe industrial chemical process that makes ammonia by reacting nitrogen and hydrogen together., which involves a reversible reactionA chemical reaction which can go both ways. between nitrogen and hydrogen:
nitrogen + hydrogen ⇌ ammonia
N2(g) + 3H2(g) ⇌ 2NH3(g)
Ammonium nitrate
Ammonium nitrate, NH4NO3, is a saltThe substance formed when the hydrogen ion in an acid is replaced by a metal ion. used as a fertiliser. It can be manufactured by reacting ammonia solution with nitric acid:
Ammonium nitrate is a source of solubleAble to dissolve in solvent. For example, sugar is soluble in water because it dissolves to form sugar solution. nitrogen, so it can be used as a ‘nitrogenous’ fertiliser.
Nitric acid
The nitric acid used in this process is also made from ammonia. Several stages are involved, but overall the process is:
ammonia + oxygen \(\rightarrow\) nitric acid + water
NH3(g) + 2O2(g) \(\rightarrow\) HNO3(aq) + H2O(l)
Ammonium sulfate
Ammonium sulfate (NH4)2SO4 is another salt used as a fertiliser. It can be made by reacting ammonia solution with sulfuric acid: