December 4, 2013 In your assigned seat working on the Do Now when the bell rings. IF I CANNOT HEAR THE MUSIC YOU ARE TOO LOUD. Turn in HW #4 (quiz grade). Turn in any late HW, Projects, etc. Pick up a White board, sock, and marker. DO NOW: Complete the warm up you picked up (quarter sheet). This will be collected.

The answers are … Element Atomic # Atomic Mass Protons Neutrons Electrons Mg 12 24 A B C P 15 D E 16 F K G 39 H I 19 12 12 12 31 15 15 19 19 20

Tutoring Thursday 12-5 afterschool 2:30-3:30

Homework Vocab column #1 * Post Lab Questions due Friday * *graded

Week of 12-2-2013 12-2: Solutions Test 12-3: Equilibrium (HW: #4) 12-4: Equilibrium, Lab, Gas Laws intro (HW: Vocab #1, Lab questions due Friday) 12-5: Gas Laws (HW: Vocab #2, Study) Equilibrium Quiz 12-6: Energy/Thermochem Test Gas Laws (HW: Vocab #3, Solutions Test Corrections)

Agenda 12-3 Do Now House keeping Equilibrium Wrap Up Equilibrium Practice Ice Cream Lab Intro to Gas Laws Video

Objectives Infer the shift in the equilibrium when a stress is applied to a chemical system ( Le Chatelier’s Principle)

Occurs when the rate of the forward reaction is equal Equilibrium Occurs when the rate of the forward reaction is equal to the rate of the backward reaction

Equilibrium Constant (Keq) A measure of how far a reaction goes to the right

[ ] = concentration

Keq > 1 More products than reactants Keq < 1 More reactants than products

Once a reaction reaches equilibrium can it ever change?? YES!!! All it takes is a change in either the forward or reverse rates.

(and therefore changes What changes rxn rate (and therefore changes the equilibrium): Concentration Pressure Temperature

Le Chatelier’s Principle If changes are made to a system in equilibrium, the RXN will shift in the direction that will reduce the change

Concentration If substance is added, the rxn will shift away from that side; If substance is removed, the rxn will shift towards that side

If pressure is increased, the rxn will shift to the side that will produce fewer molecules (compare moles of gas)

Increased temp will shift the rxn to the side that absorbs heat Temperature Increased temp will shift the rxn to the side that absorbs heat

Equilibrium Practice

We all Scream for Ice Cream Get into groups 5 minutes to read through intro 2 pre-lab questions Lab with partners BE SURE TO RECORD ANY DATA If you finish early start working on post-lab questions. POST LAB QUESTIONS ARE DUE FRIDAY

Intro to Ideal Gas Laws Before : 1 thing you know from kinetics and equilibrium about gases During: 3 bullet points (most important) After: 1 thing you are excited to learn more about from the video http://www.youtube.com/watch?v=BxUS1K7xu30&list=PL8dPuuaLjXtPHzzYuWy6fYEaX9mQQ8oGr

Exit Ticket 1. Ammonia is produced commercially by the Haber reaction: N2(g) + 3 H2(g) ↔ 2 NH3(g) + heat The formation of ammonia is favored by (A) an increase in pressure (B) a decrease in pressure (C)removal of N2(g) (D)removal of H2(g) 2. Given the reaction at equilibrium: 2 SO2(g) + O2(g) ↔ 2 SO3(g) + heat Which change will shift the equilibrium to the right? (A) increasing the temperature (B) increasing the pressure C)decreasing the amount of SO2(g) (D)decreasing the amount of O2(g) 3rd 4th