Making Ammonia - The Haber Process

- Produces ammonia from nitrogen and hydrogen

- Reaction uses a high temperature, high pressure and a catalyst to produce a reasonable yield of ammonia in a short time.

Used to manufacture ammonia (used to make fertilisers and other chemicals).

Nitrogen from air, Hydrogen (usually) from natural gas.

>>These sre purified and mixed in the correct proportions.

Then passed over an iron catalyst at a temperature of about 450ºC and a pressure of about 200 atmospheres.

Gases are cooled so ammonia condenses

Liquid ammonia = removed from unreacted gases and are recycled.

Yield = less than 20%, but ammonia is produced quickly and no gases are wasted.

Conditions in Haber process - vary in different places but always chosen to produce the best yield as qickly as possible.

NH₃

Hydrogen + Nitrogen = Ammonia

Balanced equation: 3 H₂ + N₂ → 2 NH₃

_{Reversible, ammonia breaks down into nitrogen and hydrogen .·. reaction does not go to completion.}