Le Chatelier’s principle—restated and illustrated with phase diagrams

Abstract

Le Chatelier’s principle is derived mathematically and presented in a form that confirms the original proposal by Le Chatelier with some important qualifications. Le Chatelier’s principle applies to the changes in a potential, which is conjugate to the extensive variable used to define the disturbance of the system. It applies to the net effect of several internal processes but not to the second one of two consecutive processes unless the first one is rapid enough to occur during the disturbance. Phase diagrams are used to illustrate various applications of Le Chatelier’s principle.