Haber Process & NPK fertilisers (Haber Process (How (purified gases…
Haber Process & NPK fertilisers
produce nitrogen based fertilisers
purified gases passed over catalyst of iron at
high temp about 450C
high pressure 200 atmospheres
Some H and N reacts to form ammonia
The reaction is reversible, some of the ammonia
produced breaks down into N and H:
On cooling, the ammonia liquefies and is removed.
The remaining H & N are recycled.
interpret graphs of reaction conditions versus rate
Recognise and use
expressions in decimal form.
Use ratios, fractions and
•• apply the principles of dynamic equilibrium in
Reversible reactions and dynamic equilibrium to the Haber process
•• explain the trade-off between rate of production and position of
•• explain how the commercially used conditions for the Haber
process are related to the availability and cost of raw materials and
energy supplies, control of equilibrium position and rate.
achieved using a variety of raw materials
in several integrated processes.
Ammonia can be used to manufacture
cannot be used directly as a fertiliser
treated with nitric acid or sulfuric acid to produce
soluble salts that can be used as fertilisers.
Compounds of N, phosphorus and potassium improve agricultural productivity.
NPK fertilisers are formulations of various salts containing appropriate percentages of the elements.
Students should be able to:
•• recall the names of the salts produced when phosphate rock is
treated with nitric acid, sulfuric acid and phosphoric acid
•• compare the industrial production of fertilisers with laboratory
preparations of the same compounds, given appropriate