LeChatelier’s Principle states that if a stress (change in temperature, pressure, or volume) is applied to an equilibrium system, the system will react to reduce the stress by shifting to the direction that will minimize the stress.
Example: Say you have 6 Boys(B) and 6 Girls(G) in a room. They can form 6 Families(F).
6B + 6G --> 6F
You then borrow 2 families from another room. Expressed as follows:
6B + 6G --> 8F The equilibrium is now broken (stress on system)
The chemical equation must readjust to be placed back in to a state of equilibrium.
6B + 6G --> 7F
+1 B +1 G
This can now be expressed as:
7B + 7G --> 7F
An equilibrium is once again created. As a rule of thumb, almost all chemical equations have an equilibrium. The use of boys, girls, and families was used for simplicity in explaining the concept.