LE CHATELIER'S PRINCIPLE

Le Chatelier's principle describes what happens to a system when something momentarily takes it away from equilibrium. This section focuses on three ways in which we can change the conditions of a chemical reaction at equilibrium:
(1) changing the concentration of one of the components
(2) changing the pressure
(3) changing the temperature at which the reaction is run

To show this, consider the steam reforming reaction used in previous experiments.
 C (s) + H₂O (g) CO (g) + H₂ (g)
In this experiment the volume of the system can be changed and the corresponding changes in equilibrium amounts of carbon, water, carbon monoxide, and hydrogen can be observed.


http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch16/graphics/16_11fig.gif