1. Le Châtelier and His Principle

2. Warm-Up
(1) A mixture of H2 and I2 is allowed to react at 448oC. When equilibrium is established, the concentrations of the participants are found to be [H2] = 0.46 M, [I2] = 0.39 M, and [HI] = 3.0 M. Calculate the value of the Keq at 448oC. H2(g) + I2(g) <=====> 2 HI(g) (2) Calculate the equilibrium constant, Keq, for the following reaction at 25 °C, if [NO] = M, [O2] = M and [NO2]eq = M. 2 NO (g) + O2 (g)  2 NO2 (g)

3. Warm-Up Answers
(1) (2) Keq = 12.1

4. Homework Answers EQUILIBRIUM: [SO3]2
Keq = (2) n/a = all liquids
[SO2]3 [O2]
1 [CH4] [H2O]
Keq = (4) Keq =
[H2]2 [O2] [H2]3 [CO]
(5) Keq = [CO2]

5. Homework Answers
(6) (7) Keq < 1 thus reactants favored (8) 4.01 (9) 0.50 (10) 1.41 M (11) (12) 9.81 X ( )

6. Solutions/Acid & Bases RETEST
Grades posted in Power School !
NO Retest Tutoring – BUT mandatory test review after school on Today. You MUST come in and look over your previous test before taking the retest.
You MUST plan to RETEST on Wednesday

7. ATTENDANCE RECOVERY
Last day for attendance recovery is THURSDAY, January 7, 2016! All forms must be submitted by Friday, January 8, 2106! If you have any questions about your attendance…please see me ASAP!!

8. ALL make-up work must be submitted by this Friday, January 8, 2016

9. The Week Ahead…. Day What We’ll Be Doing Mon / Tues Wed Thurs Fri Mon
Unit 11 – Equilibrium
Wed
Unit 11 QUIZ (Grade)
Reference Table Scavenger Hunt (Grade)
Exam Review Day 1
Thurs
Exam Review Packet – Grade Sheet #1
Take/Discuss Released Test (Short Version)
Exam Review Day 2
Fri
Exam Review Packet – Grade Sheet #2
Cumulative Review Demo – Post-Test (Grade)
Exam Review Day 3
Mon
Exam Review Packet – Grade Sheet #3
Take/Discuss Released Test (Long Version)
Exam Review Day 4
Tues
Exam Review Packet – Grade Sheet #4
Cumulative Review Activity
Final Exam Reminders

10. Le Châtelier’s Principle
If a stress is applied to a system at equilibrium, the system shifts to reduce the stress.

11. The 3 stresses of Chemistry
Concentration
Temperature
Pressure
PRODUCTS
REACTANTS

12. Concentration
Increasing the concentration of one of the reactants or products causes a shift toward the other side.
Decreasing the concentration of one of the reactants or products causes a shift toward the same side.

13. Temperature Treat heat as a product for exothermic
Treat heat as a reactant for endothermic
Refer back to rules for concentration

14. Pressure
Note-only applies if there is an unequal amount of gases on each side
Increasing the pressure will cause a shift toward the side with the lower number of moles of gas.
Decreasing the pressure will cause a shift toward the side with the higher number of moles of gas.

15. Learning Team Challenge
N2 (g) H2 (g) ⇆ NH3 (g)
Would the equilibrium shift toward the reactants OR products if……
Hydrogen was removed?
Ammonia was added?
Hydrogen was added?
Pressure was increased?

16. 12.6 J + H2 (g) + I2 (g)  2HI (g)
How would the equilibrium shift when the following stresses are applied to the system?
Add hydrogen iodide
Increase the temperature
Decrease the pressure
Remove Iodine

17. UNIVERSITY OF EQUILIBRIUM
hemistry_lechateliers/index.html
CAN YOU GRADUATE
WITH HONORS?
Hawkins’ Wiki Page – January 5 – Click on the Link for University of Equilibrium
- Start with Admissions Requirements
- Complete Years 1 – 4
- Take Final Exam – show Hawkins’ Score

18. You try! C2H2 (g) + H2O (g) ⇆ CH3CHO (g)
The above reaction is endothermic, predict the shift in the equilibrium
(1) You increase CH3CHO
(2) You decrease C2H2
(3) You increase H2O
(4) You decrease the temperature

19. Goals You should now be able to…
Predict what side of the reaction will be favored given a stressor

20. Exit Ticket
For the equilibrium system (1) Write the equation for the calculating the equilibrium constant How will the above reaction shift if: (2) More chlorine is added? (3) Pressure is increased (note: all reactants and products are gases) BONUS: Keq = 35. If the concentrations of PCl5 and PCl3 are 0.025M and 0.68M respectively, what is the concentration of the Cl2?

21. HOMEWORK
Worksheet
Equilibrium: #13
Le Chatelier’s Principle: ALL (1 – 5) – omit 2 D
UNIT 11 QUIZ TOMORROW !!
BRING YOUR ORGANIZED NOTEBOOK TOMORROW TO BEGIN EXAM REVIEW!!