Le Chatelier's principle

Le Chatelier's principle (pronounced UK: /lə ʃæˈtɛljeɪ/ or US: /ˈʃɑːtəljeɪ/), also called Chatelier's principle (or the Equilibrium Law), is a principle of chemistry used to predict the effect of a change in conditions on chemical equilibrium. The principle is named after French chemist Henry Louis Le Chatelier, and sometimes also credited to Karl Ferdinand Braun, who discovered it independently. It can be defined as:

If the equilibrium of a system is disturbed by a change in one or more of the determining factors (as temperature, pressure, or concentration) the system tends to adjust itself to a new equilibrium by counteracting as far as possible the effect of the change

— Le Chatelier's principle, Merriam-Webster Dictionary

In scenarios outside thermodynamic equilibrium, there can arise phenomena in contradiction to an over-general statement of Le Chatelier's principle.

Le Chatelier's principle is sometimes alluded to in discussions of topics other than thermodynamics.