To predict how a system will respond to a stress, use le Châtelier's principle by applying the following three steps:

1.Identify the stress. In the first case, the applied stress is an decrease in temperature.

2. Identify how the system will respond to the stress.  Remember that the system will always do the opposite of the applied stress.  In this case, the system will try to increase the temperature.  This means the energy term must increase.

Applied Stress	Le Chatelier's Principle Prediction of Response to Stress
	CoCl42-	+ 6H2O		Co(H2O)62+	+ 4Cl-	+ energy
Decrease T	?	?		?	?	Increase

At 0 ºC, the color of the solution is pink.

3. Identify how each substance will respond to the change, using the "see-saw" effect. In this case each substance on the right of the equilibrium sign will go up, and everything on the left side will go down.  The reaction will shift to the right, and become more pink.

Applied Stress	Le Chatelier's Principle Prediction of Response to Stress
	CoCl42-	+ 6H2O		Co(H2O)62+	+ 4Cl-	+ energy
Decrease T	Decrease	Decrease		Increase	Increase	Increase

At 90 ºC, the color of the solution is deep blue.

We can do the same thing when the stress is an increase in T.  In this case the system will respond by decreasing the temperature.  Then the end result will be that the reaction shifts to the right and becomes more blue.

Applied Stress	Le Chatelier's Principle Prediction of Response to Stress
	CoCl42-	+ 6H2O		Co(H2O)62+	+ 4Cl-	+ energy
Increase T	Increase	Increase		Decrease	Decrease	Decrease