1888 – France
‘When a system in equilibrium is subjected to a change in conditions, it adjusts itself so as to try to oppose that change’
The principle is a consequence of the law of conservation of energy.
Le Chatelier’s principal is valuable in understanding how to control the industrial production of chemicals such as ammonia.
Nitrogen and hydrogen react to form ammonia. When the pressure of this system is increased, more ammonia is produced, but when the pressure is lowered, ammonia is decomposed into hydrogen and nitrogen. Thus by controlling pressure and temperature, ammonia can be produced with the minimum of waste.
Le Chatelier was a chemist and is remembered for inventing thermocouples for measuring high temperatures (1877) and oxyacetylene welding (1895).