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
Mg
12
24
P
15
K
19
G
Protons
Neutrons
Electrons
12
A
B
12
C
12
D
31
E
15
16
F
15
39
19
H
20
I
19
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
1.
2.
3.
4.
5.
6.
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)
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
aA  bB  cC  dD
c
d
[C] [D]
K eq 
a
b
[A] [B]
[ ] = 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.
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
Pressure
If pressure is increased,
the rxn will shift to the
side that will produce
fewer molecules
(compare moles of gas)
Temperature
Increased temp will
shift the rxn to the
side that absorbs heat
Equilibrium Practice
We all Scream for Ice Cream
1.
2.
3.
4.
5.
6.
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 postlab questions.
7. 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
3rd
4th
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)