Reversible reaction between nitrogen and hydrogen to form ammonia
Haber process
Nitrogen + hydrogen ⇌ ammonia
Equilibrium
Ammonia breaks down again into nitrogen and hydrogen
Factors affecting rate of attainment of equilibrium
1. Higher temperature (more kinetic energy, more frequent successful collisions)
2. Higher pressure/concentration (more particles in a given volume, more frequent successful collisions)
3. Catalyst
For the Haber process, the purified gases are passed over a catalyst of iron at a high temperature (about 450 °C) and a high pressure (about 200 atmospheres)
Higher temperature
Shifts equilibrium towards the reactants (as the forwards reaction is exothermic)
Catalyst is used because of the effect of having an increased rate of reaction, however they are also expensive
High temperatures and pressures can be expensive and dangerous as well (particularly pressures) and the equipment required for them can be very expensive
Compounds of nitrogen, phosphorus and potassium are used as fertilisers to improve agricultural productivity
NPK fertilisers contain compounds of all three elements
Ammonia reacts with nitric acid
Produces ammonium nitrate (a salt used as a fertiliser)
