1. Le Chatelier’s Principle

2. Evaluation/Assessment:
Objective:
Today I will be able to:
Apply Le Chatelier’s Principle to explaining how equilibrium systems adjust to stresses of concentration, temperature, pressure and volume
Evaluation/Assessment:
Informal assessment: Monitoring student interactions and questions as they complete the Le Chatelier’s Principle practice.
Formal assessment: Analyzing student responses to practice and the exit ticket
Common Core Connection
Build Strong Content Knowledge
Reason abstractly and quantitatively
Make sense of problems and persevere in solving them

3. Lesson Sequence Evaluate: Warm – Up
Explain: Le Chatelier’s Principle Notes
Elaborate: Le Chatelier’s Principle Practice
Evaluate: Exit Ticket

4. Warm - Up
At equilibrium, the rate of the forward reaction ____________ the rate of the reverse reaction.
Under the same conditions, at equilibrium the concentrations of both reactants and products remain _____________.
Equilibrium may be approached from different starting points, but at equilibrium the ratio of products to reactants will be ______________.

5. Objective Today I will be able to:
Apply Le Chatelier’s Principle to explaining how equilibrium systems adjust to stresses of concentration, temperature, pressure and volume

6. Homework
Finish Le Chatelier’s Principle Practice

7. Agenda Warm – Up Le Chatelier’s Principle Notes
Le Chatelier’s Principle Practice
Exit Ticket

8. Equilibrium Expressions Guided Inquiry
Lets look at the Inquiry together and draw some conclusions!

9. Le Chatelier’s Principle Notes

10. Le Chatelier’s Principle
When an equilibrium system is subjected to a change, the system will “shift” to counteract the change
Example reaction
A (g) + B (g)  C (g) + X kJ

11. A (g) + B (g)  C (g) + X kJ
Add a reactant – moves to product side to consume it
Add a product – moves to reactant side to consume it
Remove a reactant – moves to reactant side to produce more
Remove a product – moves to product side to produce more

12. A (g) + B (g)  C (g) + X kJ
Increase temperature – because it is an exothermic reaction, shift to the reactants side
Decrease temperature – shift to the products
The opposite would be true for an endothermic reaction

13. A (g) + B (g)  C (g) + X kJ
Increase pressure – move to side with less moles of gas
Decrease pressure – move to side with more moles of gas
Increase volume – move to side with more moles of gas
Decrease volume – move to side with less moles of gas

14. Le Chatelier’s Principle Practice

15. Exit Ticket Given the following reaction:
Use Le Chatelier’s principle to determine what would happen if the following changes were made
Increase the concentration of N2
Increase the concentration of NH3
Remove NH3 from the reaction after it is made