1. Le Châtelier’s Principle

2. Le Châtelier’s Principle
If stress is applied to a system the system shifts to relieve the stress

3. Change in Concentration
Mountains and mole-hills:
If stress is added the reaction must shift in the opposite direction to “remove” the mountain
If stress is removed the hole must shift in the same direction to “fill in” the hole

4. Change in Concentration
Which direction will the reaction shift if the concentration of CO is increased?
To even out the pile it must shift right

5. Change in Concentration
Which direction will the reaction shift if the concentration of CO is decreased?
To even out the pile it must shift left

6. Change in Concentration
Which direction will the reaction shift if the concentration of CH4is increased?
SHIFT LEFT

7. Change in Concentration
Which direction will the reaction shift if the concentration of H2 is decreased?
SHIFT LEFT

8. Change in Concentration
Which direction will the reaction shift if the concentration of H2O is decreased?
SHIFT RIGHT

9. Change in Concentration
Which direction will the reaction shift if the concentration of H2 is increased?
SHIFT RIGHT

10. Changes in Volume
Remember that decreasing volume is also increasing pressure
If pressure is increased, the reaction shifts to the side with the least amount of moles

11. Changes in Volume
What will happen if volume is decreased?

12. The reaction shifts towards the right to relieve stress
Changes in Volume
The reaction shifts towards the right to relieve stress

13. There would be no change because there are equal moles on each side!!!
Changes in Volume
Which direction will the reaction shift if the volume is decreased?
There would be no change because there are equal moles on each side!!!

14. Changes in Temperature
Temperature changes like concentration…mountains and mole-hills 

15. Changes in Temperature
Which direction will the reaction shift if heat is added?
What will happen if heat is removed?

16. Changes in Temperature

17. Just a Note…
If heat is on the right side of the reaction, it is exothermic
If heat is on the left side of the reaction, it is endothermic

18. Review

19. Review

20. Review