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Published by mary.c.king, 2017-04-30 15:47:49

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•  Thermodynamics
 
•  Kine0cs
 
•  Equilibrium
 
•  Acids
 &
 Bases
 
 
•  Buffers
 
•  Solubility
 Product
 
•  Electrochemistry
 
•  Nuclear
 Chemistry
 
•  Organic
 Chemistry
 

 

1
 

Student Preparation Strategy

My strategy to get students to read the sections of the chapter I am planning to cover in
the class would include the following:

1) Briefly outline the main concepts to be covered in the lesson. In the example
provided on the next pages, I am planning a lesson on Le Chatelier’s Principle,
one of the Chapter goals for Chemical Equilibrium. The ‘hook’ to entice them into
reading the chapter will be a practical application of Le Chatelier’s Principle known
as the Haber Process for commercially manufacturing ammonia.

2) I include a picture of the Haber Process from the textbook to pique their interest.

3) They must read the chapter sections, watch a short youtube video and then
complete a table which requires comprehension of Le Chatelier’s Principle and
critical thinking.

4) This CPA will be worth 2% of their assignment grade.

Example of my Student Preparation Strategy

CHEM 1412 Chapter 17 - Chemical Equilibrium

Lesson: Chemical Equilibrium – Applying Le Chatelier’s Principle
What’s it About? Disturbing a system at equilibrium and exploiting Le Chatelier’s
Principle for commercial gain. We will discuss in detail the process of making ammonia,
a practical application of Le Chatelier’s Principle.

Why should you care about how NH3 is made? Because we need ammonia to make
fertilizer, explosives, and many pharmceuticals, and you need to learn about Chemical
Equilibrium.

Why should you do this Class Preparation Assignment? Because it is worth 2% of
your assignment grade and you will get more out of the class.

Class Preparation Assignment:

1) Read Chapter 17-6 and 17-7 in your Chemistry text

2) Watch the video on the ammonia making process (10 minutes):
https://www.youtube.com/watch?v=Tt6diRJli6Q

3) How would the equilibrium of the reaction be influenced by the following
changes?

N2(g) + 3H2(g) 2NH3(g) ∆H⁰rxn = -92 kJ/mol

Change Effect on Reaction
a) Increasing reaction temperature (Shift to Right or Left or no shift)

b) Decreasing the container volume

c) Increasing the concentration of H2

d) Introducing a platinum catalyst

e) Decreasing the concentration of NH3

BOPPPS LESSON PLAN

COURSE: CHEM 1412 - General Chemistry II
Lesson Title: Chemical Equilibrium - Applying Le Chatelier's Principle

Bridge: I will start by telling the students a story about Joe, the owner of a pharmaceutical company, who asked his chemist to
review the steps involved in synthesizing a promising drug to see if she could increase the low yield so he could make a profit by
commercializing the drug. She decides that the best way to improve the yield of the drug is to take advantage of Le Chatelier’s
principle. By removing water, the product of one of the key steps in the synthesis, she is able to triple the yield, and Joe is able to
make huge profits from the drug. I will then move on to explaining the Haber Process, the industrial manufacturing process to make
ammonia. I will talk about how this process has changed the world because ammonia is such an important starting material for many
reactions that are used to manufacture important commodities such as drugs, explosives, and fertilizers.
Estimated time: 10 minutes

Course Student Learning Outcome:
Apply the principles of equilibrium to aqueous systems using Le Chatelier’s Principle to predict the effects of concentration, pressure,
and temperature changes on equilibrium mixtures.
Learning Objectives: By the end of this lesson, students will be able to:

1. By the end of this lesson, the student will be able to predict the effect of disturbing a system at equilibrium that can occur by
changing the concentration of both reactants and/or products, by changing the temperature, or by changing the pressure of the
system. The effect will be a shift of the equilibrium to the right or left of the reaction equation. (comprehension, synthesis)

2. By the end of this lesson, the student will be able to predict the effect of disturbing a system at equilibrium that can occur by
changing the concentration of both reactants and/or products, by changing the temperature, or by changing the pressure of the
system. The effect will be a shift of the equilibrium to the right or left of the reaction equation. (application, evaluation)

Pre-Assessment: My pre-assessment method of choice is to administer a short multiple choice quiz using Poll Everywhere. The
questions are designed to allow me to determine their knowledge of reversible reactions and also whether they have prepared for the
lesson by doing the reading assignment.
Estimated time:
Participatory Learning:
HIGHLIGHT AND LABEL THE FOLLOWING:

 4 questions with Bloom’s level identified
 New instructional technology you are trying
 At least one classroom assessment technique (CAT)

Time Instructor Activities Learner Activities Lesson Materials

15 I will discuss the commercial limitations of the Answer question: what is Le Chatelier's principle? Slide showing

min. equilibrium reaction between N2 and H2 and (knowledge); Why does a catalyst not affect the limitations of ammonia

the Haber Process solution to ammonia equilibrium constant?(knowledge, comprehension) reaction,

production. Show students the PhET Students will predict how a change in reaction slide with Haber

reversible reaction simulator and conditions will impact the equilibrium and then solution and link to

demonstrate the reaction. condition changes observe the demonstration of the simulation so PhET reversible

they suggest using the simulator they can see how their prediction compares to the reactions simulator

simulation outcome.

10 Explain the concept of Q vs K and how it is Answer question: can you think of an easy way to slides, hand-out notes

min. used to predict a shift when concentrations of remember the direction of the shift if Q>K or Q<K (modified notes created

both products and reactants have changed (comprehension, analytical, synthesis) by Dr. K. Abayan)

10 Explain how to set up ICE tables based on Answer question: do we subtract or add 'x' in the slides, hand-out notes

min. the Q analysis and calculate new equilibrium change column? (analysis, comprehension) (modified notes created

concentrations by Dr. K. Abayan)

15 Have class split into groups of 4 and assign a One person from each group writes the Q analysis slides, hand-out notes

min. different problem to each group from hand- and ICE table on the board and another explains (modified notes created

out. their table to the class. Provide an example of a by Dr. K. Abayan)

reaction where the product yield can be improved
by implementing Le Chatelier’s principle.

(comprehension, synthesis, evaluation)

Post-assessment: My formative post-assessment will be based upon the quality of responses and level of participation from the

students that I observe while working through the interactive problem solution on the board with them at the end of the lesson in

addition to the answers I get to the question on improving product yield (see Summary).

Estimated time: 5 minutes (simultaneous with Summary time)

Summary: I will close the lesson by asking them to provide me with an example of a reaction where the product yield can be
improved by implementing Le Chatelier’s Principle, and then work through solving a complex equilibrium problem on the board,

soliciting their input through each step, and reviewing all of the concepts and techniques covered in the lesson as we progress

through the solution together.

Estimated time: 5 minutes

ATTACH ANY LESSON MATERIALS (SLIDES, HANDOUTS, ETC.)

A Practical Application of Equilibrium:
The Haber Process

N2(g) + 3 H2(g) !#Fe &#met#al ox#ides#" 2 NH3(g) $Ho = %92.22 kJ

This reaction is run at a T = 450oC and P of N2 =200 to 1000 atm.
$G<0 which is favorable.
$H<0 is also favorable.
$S<0 which is unfavorable.

However the reaction kinetics are very slow at low temperatures.
Haber's solution to this dilemma.

2

A Practical Application of Equilibrium:
The Haber Process

h"ps://www.youtube.com/watch?v=Tt6diRJli6Q
  3

Disturbing a System at Equilibrium:
Predictions

Example 17-9: Given the reaction below at equilibrium
in a closed container at 500oC. How would the
equilibrium be influenced by the following?

N 2(g) + 3 H2(g) →←2 NH3(g) ΔH o = −92 kJ/mol
rxn

Factor Effect on reaction procedure

a. Increasing the reaction temperature

b. Decreasing the reaction temperature

c. Increasing the pressure by decreasing the volume

d. Increase the concentration of H2 4
e. Decrease the concentration of NH3
f. Introducing a platinum catalyst

PhET
 Reversible
 ReacAon
 Simulator
 

h"ps://phet.colorado.edu/en/simulaAon/legacy/reversible-­‐reacAons
 

Disturbing a System at Equilibrium:
Predictions

Example 17-11: How will an increase in temperature
affect each of the following reactions?

Reaction Effect on Equilibrium

a. 2 NO2(g) →← N2O4(g) ΔH o <0
rxn

b. H2(g) + Cl2(g) →← 2 HCl(g) + 92 kJ

c. H2(g) + I2(g) → 2 HI(g) ΔH = +25 kJ

6

Disturbing a System at Equilibrium:
Calculations

Example 17-12: An equilibrium mixture from the
following reaction was found to contain 0.20 mol/L of
A, 0.30 mol/L of B, and 0.30 mol/L of C. What is the
value of Kc for this reaction?

A(g) !"B(g) + C(g)
Equil. []'s 0.20M 0.30M 0.30M

K c = [B][C] = (0.30)(0.30) = 0.45
[A] (0.20)

7

Disturbing a System at Equilibrium:
Calculations

•  If the volume of the reaction vessel were suddenly
doubled while the temperature remained constant,
what would be the new equilibrium concentrations?

1  Calculate Q, after the volume has been doubled:

A(g) !"B(g) + C(g)

Equil. []'s 0.10 M 0.15 M 0.15 M

Q= [B][C] = (0.15)(0.15) = 0.22
[A] (0.10)

8

Disturbing a System at Equilibrium:
Calculations

•  Since Q<Kc the reaction will shift to the right to re-
establish the equilibrium.

2  Use algebra to represent the new concentrations.

A(g) !! B(g) + C(g)
0.15M 0.15M
New initial []'s 0.10M +x M +x M

Change -x M

New Equil. []'s (0.10-x) M (0.15+x) M (0.15+x) M

9

Disturbing a System at Equilibrium:
Calculations

K = [B][C] = 0.45 = (0.15 + x)(0.15 + x )
[A] (0.10 ! x)
c

Solve this quadratic equation
0.045-0.45x=0.0225+0.30x+x2
x2 + 0.75x ! 0.0225 = 0

10

Disturbing a System at Equilibrium:
Calculations

x= -b± b2 − 4ac
2a

x = − 0.75 ± (0.75)2 − 4(1)(− 0.0225)
2(1)

x= − 0.75 ± 0.81 = −0.78 and 0.03 M
2

11

Disturbing a System at Equilibrium:
Calculations

Since 0 < x < 0.10, we can discard - 0.78 as an answer.
The only posible value is x = 0.03 M.

[A] = (0.10 − x) M = 0.07 M
[B]= [C]= (0.15 + x) M = 0.18 M

These are the new concentrat ions after
the equilibriu m has been disturbed.

12

1

Chapter 17 Chemical Equilibrium

Not all reactions are one way reactions as we’ve seen in the past as seen by the one way
arrow.

aA + bB → cC + dD

In fact many chemical reactions can occur in either direction, called reversible reactions. This

is denoted by the double-sided arrow, .

aA + bB cC + dD

Important: Remember represent chemical equilibrium and is not the same as ↔.

The double headed arrowed represent resonance structures. Do not use the double-

headed arrows ↔. for equilibrium problems.

17.1 Basic Concepts

Chemical equilibria is dynamic; that is individual molecules are continually reacting even though
the overall composition of the reaction mixture does not change.

2

Important: Ultimately chemical equilibrium is reached when the rate of the forward reaction is
equal to the rate of the reverse reaction:

17.2 The Equilibrium Constant

Reminder: Chemical equilibrium is reached whe the rate of the forward reaction is equal to the
rate of the reverse reaction

Consider the following one step reaction:

aA + bB cC + dD

Using concepts from rate kinetics
The rate expression for the forward reaction is:

= [][]

3

The rate expression for the reverse reaction is:

= [][]

At chemical equilibrium the rate forward = rate reverse

=

[][] = [][]

Taking the ratio of kr/kf

[][]
= [][]

The ratio of kr/kf is what’s now the equilibrium constant (K) sometimes denoted as Keq

[][]
= [][]

The equilibrium constant is a ratio of the equilibrium concentration of the products over the
equilibrium concentration of the reactants.

What are the units of K? There are no formal units of K, because they don’t make any sense.

Important features of K you should know!

1. K is dependent on temperature so, if a K is listed it’s specified for a reaction at a certain
temperature.

2. K does not depend on the “initial concentrations”. What does depend on the “initial
concentrations” is the reaction quotient, Q.

3. K measures the extent of the reaction:
a. If K > 1 that means there are more products than reactants at equilibrium
b. If K < 1 that means there are more reactants than products at equilibrium.
c. If K = 1 that means there are equal amounts of products and reactants at
equilibrium.

4. K is related to a balanced chemical equation.

4

5. Pure solids and pure liquids are never expressed in the equilibrium expression.

Example: A 5.00 L container is filled with nitrogen and hydrogen at 500.˚C. When

equilibrium is established, 3.01 mol of N2, 2.10 mol of H2 and 0.565 mole of NH3 are present.
Evaluate Kc for the following reaction at 500.˚C

N2 (g) + 3 H2 (g) 2 NH3 (g)

How to begin to approach almost every equilibrium problem:

1. Rewrite the reaction and ensure the reaction is balanced

2. Write the equilibrium expression to the right of your reaction as you will need space
below to create a RICE/ICE Diagram. Double check if you’ve included pure solids or

pure liquids in the expression. If you did you made a mistake!!

3. Ask yourself if there are any initial concentrations given and fill in the appropriate
information. Important: The RICE/ICE charge is always in units of Molarity be sure you
are entering in molarity

4. The change is represented +/- n*x (where n is the stoichiometry coefficents) the +/-
depends on the direction of the reaction!

5. Ask yourself are there any equilibrium concentrations given and fill in the appropriate
information. Important: The RICE/ICE chart is always in units of Molarity - be sure you
are entering concentrations in molarity

a. If anything is missing in the Equilibrium Concentration portion you add down!

6. Anything that is found in the Equilibrium portion of the chart is plugged into the
Equilibrium expression of your chart.

7. Solve!

Reaction
Initial Conc.
Change Conc.
Equilibrium Conc.

5

Example: A 2.00 L container is charged with 10.0 moles of N2O at a certain temperature, where
it decomposes to:

2 N2O (g) 2 N2 (g) + 3 O2 (g)

At equilibrium, 2.20 moles of N2O remain. Calculate the value of Kc for this reaction

17.3 Variation in Kc with the form of the Balanced
Equation

Consider the following balanced chemical reaction

aA (g)+ bB (g) cC (g)+ dD (g) K = 1.8E-5

Write the equilibrium expression for the above reaction.

What would happen to the value of K if we reversed the reaction?

6

What is the relationship between the original K and the new K*?
What would happen to value of K if we doubled the reaction?
What is the relationship between the original K and the new K*.

What if the overall reaction happened in mechanistic steps?

aA (g)+ bB (g) mM K1 = 1.80E-5

mM cC (g)+ dD K2 = 5.56E-10

Implications of the Equilibrium Constant K 7
Keq
Original Reaction reactants products

Reverse products reactants K* = 1/Keq

Factor n * reactants n *products K* = (Keq)n

reactants intermediates Keq1
Keq2
Sequence of Reactions intermediates products
K*rxn = Keq1* Keq2
reactants products

Example: You are given the following chemical equation and its equilibrium constant at a given
temperature.

2 HBr (g) + Cl2 (g) 2HCl (g) + Br2 (g) Kc = 4.0E4

What is the value of K for the following reactions at the same temperature?

a) 4 HBr (g) + 2 Cl2 (g) 4HCl (g) + 2 Br2 (g)

b) HCl (g) + ½ Br2 HBr (g) + ½ Cl2

16.4 The Reaction Quotient

Consider the following balanced chemical reaction

aA (g)+ bB (g) cC (g)+ dD (g)

Not all reactions start at equilibrium. In fact, if one considers what is done in the lab, you start
with many reactions at initial concentrations

8

Note: The most important feature is that it tells you the direction of the reaction. You’ve already
done some of this intuitively. For example, what is the direction of the reaction if you have
nothing but reactants?

You can determine the direction of the reaction both intuitively and mathematically. How is this
done mathematically? The reaction quotient, Q, is written in the same manner as K.

Example: At a very high temperature, Kc = 65.0 for the following reaction.

2HI (g) H2 (g) + I2 (g)

The following concentrations were detected initially in a mixture. Is the system at
equilibrium? If not in which direction must the reaction proceed for equilibrium to be
established?

[HI] = 0.500 M [H2]=2.80 M [I2]=3.40 M

How do you determine if the reaction is at equilibrium and the direction of the reaction?

1. Rewrite the reaction and ensure the reaction is balanced

2. Write the reaction quotient expression, Q, to the right of your reaction as you will need
space below to create a RICE/ICE chart. Double check if you’ve included pure
solids or pure liquids in the expression. If you did you made a mistake!!

3. Ask yourself are there any initial concentrations given and fill in the appropriate
information. Note: Often we use the initial concentrations to determine the direction of
the reaction before proceeding to change. Important: The concentrations in the
RICE/ICE chart are always in units of Molarity. Be sure you are entering concentrations
in molarity.

4. Anything that is found on the initial line gets plugged into the Q expression

5. Solve for Q

Reaction
Initial Conc.
Change Conc.
Equilibrium Conc.

9
1. Once the value of Q is determined, compare Q to K, by using the number line method,

which K places in the center of the number line.

Implications of the Reaction Quotient in relationship to Keq.
 If Q < K, there are more reactants than products therefore the reaction proceeds to
the right.
 If Q > K, there are more products than reactants therefore the reaction proceeds to
the left.
 If Q = K, there are more reactants than products therefore the reaction proceeds to
the right.

10

16.5 Uses of the Equilibrium Constant

Example: “The equation for the following reaction and the Kc at a certain temperature are
given. An equilibrium mixture in a 1.0 liter container contains 0.25 mol of PCl5 and 0.16 mol of
PCl3. What equilibrium concentration of Cl2 must be present? Kc=1.9

PCl3 (g) + Cl2 (g) PCl5 (g)

Example: For the following reaction, the equilibrium constant is 49.0 at a certain
temperature. If 0.400 mols each of A and B are placed in a 2.00 L container at that
temperature, what concentrations of all species are present at equilibrium?

A + B C + D K = 49.0

11

Example: Consider the same system as the one above. If 0.300 mol of A, 0.200 mol B, 0.800
mol C and 0.100 mol D are initially placed in a container and are allowed to reach equilibrium,
what are the equilibrium concentrations of all species?

Example: The equilibrium constant at a certain temperature for the reaction below is 100:

H2(g) + I2(g) 2HI(g) Kc = 100

If 1.00 mol each of H2(g) and I2(g) are placed in a 1.00 L flask, what will be the concentration of
each gas when the reaction is allowed to reach equilibrium at the given temperature?

12

17.6 Disturbing a System at Equilibrium: Predictions

Important Principle: once a reacting system has reached equilibrium, it remains at equilibrium
until it’s disturbed by some change in conditions.

Le Chateliers Principle: If a system at equilibrium is disturbed by a change in the conditions
(adding a stress to the system), the system will shift in the direction that relieves the stress to re-
establish equilibrium.

Consider the following balanced reaction:

A(aq) + B(s) C (aq)+ D(l)

1. Changes in Concentration (changes Q, the reaction quotient!)

Stress Q Direction Shift?

Increase concentration of A Q<K A(aq) + B(s) C (aq)+ D(l)
Increase concentration of C Q>K
Increase concentration of B or D No change Shift Right →
Decrease concentration of A Q>K Shift Left ←
Decrease concentration of C Q<K
No Change

Shift Left ←
Shift Right →

2. Changes in pressure or volume (For reactions that involve gases)

Think of a closed box containing the balanced chemical reaction

A (g) + 2B (g) 3C (g) + 4D (g)

What would happen to the pressure inside the box if you squeeze the box? The
pressure inside the box will increase.

A (g) + 2B (g) 3C (g) + 4D (g)

How does the reaction respond to the increasing pressure? To re-establish equilibrium,
you want to go to the side that has less moles of gas.

What would happen to the pressure inside the box if you increase the volume of the
box? The pressure inside the box decreases!

A (g) + 2B (g) 3C (g) + 4D (g)

13

How does the reaction respond to the decreasing pressure? To re-establish equilibrium you
want to go to the side which has more moles of gas.

3. Changes in temperature

 If the reaction is endothermic, treat the heat energy as it if were a reactant.

 If the reaction is exothermic, treat the heat energy as it if were a product.

Think about how the reaction would respond if you increased or decreased the temperature of
the system.

Example: Consider the following system at equilibrium

N2(g) + 3H2(g) 2NH3(g) ∆H° = –92.4 kJ

How does the equilibrium shift if:

[N2] is increased?

[NH3] is increased?
[NH3] is decreased?

Ptot is increased by compressing the system?
Ptot is increased by the addition of He(g)?

the temperature is increased?

the temperature is decreased?

a catalyst is added

14

Example: Consider the following system at equilibrium:

CO(g) + 2H2(g) CH3OH(g) ∆H° = -90.7 kJ

What will happen to the equilibrium concentration of methanol when:

a) PCO is increased

b) PH2 is decreased
c) the total pressure is increased by addition of helium gas

d) the reaction mixture is compressed

e) the temperature is increased

f) a catalyst is added

Example: Consider the following system at equilibrium

NiO(s) + CO(g) Ni(s) + CO2(g)

Given that this is an exothermic reaction, what will happen to the amount of Ni(s) when:

a) the temperature is increased

b) PCO2 is increased

c) PCO is increased
d) the mass of NiO is increased

e) the total pressure is increased by addition of He

f) the total pressure is increased by compressing the system

Important: A catalyst only increases the rate of a reaction but it has no effect on equilibrium of
a system. The reaction just reaches equilibrium faster.

15

17.8 Disturbing a system at Equilibrium: Calculation

Example: Some hydrogen and iodine are mixed at 299˚C in a 1.00 L container. When
equilibrium is reached, the following concentrations are present: [HI] = 0.490 M, [H2]= 0.080 M,
and [I2] = 0.060 M. If an additional 0.300 mol of HI is added, what will the concentrations of
each species be when the new equilibrium is established?

H2 (g) + I2 (g) 2 HI (g)

16
Example: At 22˚C the equilibrium constant, Kc for the following reaction is 4.66 E-3.
A) If 0.800 mol of N2O4 was injected into a closed 1.0 L container at 22˚C, how many moles of
each gas would be present at equilibrium?

B) If the volume was then halved to 0.500L at constant temperature, how many moles of each
gas would be present after the new equilibrium is established?

Test Questions - Formal Assessment

Lesson Objectives to be addressed by this Formal Assessment:

Lesson Objective 1: By the end of this lesson, the student will be able to predict
the effect of disturbing a system at equilibrium that can occur by changing the
concentration of both reactants and/or products, by changing the temperature, or
by changing the pressure of the system. The effect will be a shift of the equilibrium
to the right or left of the reaction equation.

Lesson Objective 2: By the end of this lesson the student will be able to use the
reaction quotient, Q, to compare with the equilibrium constant, K, in order to
complete an ICE (Initial/Change/Equilibrium) table after a system at equilibrium
has been disturbed by changes in either reactant and/or product concentrations.

a) Two Multiple Choice Questions:

1. Consider the following reaction at 445oC, for which Kc is 0.020:

2HI(g) ⇌ H2(g) + I2(g)

If a mixture of H2, I2, and HI in a vessel at 445oC has the following
concentrations: [HI] = 2.0 M, [H2] = 0.50 M and [I2] = 0.10 M, which one of
the following statements concerning the reaction quotient, Qc, is TRUE?

a. Qc = Kc; the system is at equilibrium
b. Qc is less than Kc; more H2 and I2 will be produced
c. Qc is less than Kc; more HI will be produced
d. Qc is greater than Kc; more H2 and I2 will be produced
e. Qc is greater than Kc; more HI will be produced

Bloomberg: knowledge, analysis, evaluation, application

2. For a specific reaction, which of the following statements is TRUE about the
equilibrium constant, K?

a. it always remains the same at different reaction conditions.
b. it increases if the concentration of one of the products is increased
c. it changes with changes in the temperature
d. it increases if the concentration of one of the reactants is increased
e. it may be changed by the addition of a catalyst

Bloomberg: knowledge, comprehension

b) Two other questions: 1. - short answer question and 2. – problem-solving
question

1. Consider the following reaction at equilibrium for which H = -1530.4 kJ:

4NH3(g) + 3O2(g) ⇌ 2N2(g) + 6H2O(l)

In the table below, state how Q will compare to Kc and predict how the
concentration of ammonia at equilibrium will be affected by the following stresses:

Stress Applied Q = Kc, Q > Kc, Predict what will happen to [NH3]
a) decreasing the temperature or Q < Kc (increase, decrease, no change)

b) adding a catalyst

c) doubling the reaction vessel
volume

d) adding more N2(g)

e) removing O2(g)

Bloomberg: knowledge, comprehension, analysis

2. At equilibrium, a 2.50-Liter container was found to contain 1.60 moles of C,
1.60 moles of D, 0.40 moles of A, and 0.40 moles of B for the following reaction:

A(g) + B(g) ⇌ C(g) + D(g)

a) Write the equilibrium expression and calculate the equilibrium constant.

b) If 0.20 moles of B and 0.20 moles of C are added to this system, what will
the new equilibrium concentration of A be? (Hint: you must use Q)

Bloomberg: knowledge, comprehension, application, evaluation

Question #2 is a high level question: The student must have mastered all of the
Equilibrium concepts outlined in both Lesson Objectives in order to analyze and
correctly solve this problem.

Question #1 is a good analysis question because students must be careful in their
assessment of the number of moles of gas on the reactant and product sides of
the reaction. It is easy to overlook the states and include the number of moles of
water in the count, but water is not a gas in this reaction.

Rubric
 for
 CHEM
 1412
 Formal
 Laboratory
 Reports
 

Section
  Outstanding
 
  Above
 Average
 
  Satisfactory
  Needs
 
Abstract
  Improvement
 
Abstract
 is
 a
 brief
  Abstract
 section
  Abstract
 is
 a
  Abstract
 is
 simply
 a
 
Objective
  summary
 of
 the
 objective,
  consists
 of
  statement
 of
 the
  summary
 of
 the
 
Experimental
  the
 methodology
 used
 to
  objective,
 summary
  objective
 and
  experimental
 
do
 the
 experiment,
 the
  of
 procedures,
 and
  summary
 of
  procedure.
 (1-­‐2
 
Data
 &
 Results
  chemical/physical
 concept
  either
 concept
  procedures
 used.
  points)
 
tested
 or
 utilized,
 and
  covered
 by
  (2-­‐3
 points)
 
calculated
 results
  experiment
 or
  Objective
 is
 missing
 
obtained,
 including
 %
  results.
 
 (3-­‐4
  Objective
 is
 vague
  or
 incorrectly
 
error
 compared
 to
  points)
  or
 unclear
 with
  stated.
 (0
 points)
 
 
 
literature
 or
 accepted
  incorrect
 or
 
values.
 (5
 points)
  Objective
 is
 clearly
  missing
  Procedures
 are
 
Objective
 is
 a
 clear
 and
  stated
 but
  information
 (1-­‐ copied
 directly
 from
 
concise
 statement
 about
  concept(s)
 involved
  points).
  the
 Lab
 Manual,
 or
 
the
 purpose
 of
 the
  in
 the
 experiment
  Procedures
 include
  do
 not
 furnish
 
experiment
 related
 to
 the
  is
 missing,
 (2
  sufficient
 detail.
 
  enough
 information
 
concept(s)
 involved.
 (3
  points)
  Missing
 are
  on
 how
 the
 
points)
  Procedures
 include
  chemical
 equations
  experiment
 was
 
Experimental
 section
  sufficient
 detail
  and
 concepts
  carried
 out.
 Missing
 
includes
 a
 brief
 outline
 of
  and
 should
 be
 easy
  involved
 in
  are
 chemical
 
steps
 followed
 with
  to
 follow.
 
  experiment.
 (3-­‐4
  equations,
 
figures
 or
 diagrams
 of
  Chemical
 equations
  points)
  explanations
 of
 
apparatus
 or
 set-­‐up
 if
  or
 concepts
 used
 in
  results
 or
 
applicable.
 
 It
 should
 not
  experiment
 are
 not
  Data
 is
 not
  theory/concepts
 
be
 copied
 directly
 from
  included
 in
 the
  presented
 in
 tables
  involved
 in
 
the
 lab
 manual.
 
 Included
  section.
 (5-­‐6
  and
 is
 difficult
 to
  experiment.
 (1-­‐3
 
are
 chemical
 equations
  points)
  find.
 
 Unknown
  points)
 
for
 any
 reactions
 and
 a
  sample
 ID
 not
  Some
 or
 all
 of
 the
 
brief
 explanation
 of
  Data
 is
 presented
  included.
 
 Plots
  data
 and/or
 plots
 
physical
 concepts
 used
 in
  correctly,
 including
  have
 no
 title
  are
 missing
 from
 
experiment.
 
 (7
 points)
  units
 and
  and/or
 axes
 are
 not
  report.
 
 Data
 is
 
significant
 figures,
  labeled.
 
 
 Sample
  incorrectly
 recorded
 
Data
 is
 clearly
 and
  plots
 (if
 required)
  calculations
 are
  (eg.,
 buret
 volumes
 
accurately
 presented
 in
  include
 a
 title,
 axes
  missing
 from
  reported
 to
 the
 
tables
 with
 correct
 units
  are
 correctly
  Results
 section.
 
 
 
  tenths
 instead
 of
 
and
 significant
 figures;
  labeled
 and
 include
  Averages
 of
 repeat
  hundredths).
 
 (0-­‐3
 
plots
 (if
 required)
 include
  units.
 Sample
  trials
 have
 not
  points)
 
a
 title,
 axes
 are
 correctly
  calculations
 used
  been
 calculated.
 (3-­‐
labeled
 and
 include
 units,
  to
 process
 data
 are
  6
 points)
 
and
 trend
 lines
 including
  included.
 (6-­‐8
 
equation
 of
 the
 line
 and
  points)
 
R2
 are
 included.
 
 Sample
 
calculations
 used
 to
 
process
 data
 are
 included,
 
averages
 and
 standard
 
deviation
 calculated
 
where
 applicable.
 Quality
 
of
 data
 is
 determined
 by
 
comparison
 to
 actual
 or
 

Discussion
  literature
 values,
  Discussion
 section
  Discussion
 includes
  No
 discussion
 of
 
including
 %
 error.
 (10
  ties
 results
 to
  results
 and
  results,
 just
 a
 re-­‐
Conclusion
  points)
  objective
 to
  potential
 sources
  statement
 of
 
Post-­‐Lab
 Questions
  A
 brief
 discussion
 relating
  evaluate
 methods
  of
 errors
 but
 does
  procedures.
 (0-­‐2
 
Overall
 Writing
 
  the
 results
 and
 how
 well
  but
 does
 not
  not
 relate
 the
  points)
 
they
 relate
 to
 the
 theory
  include
 difficulties
  results
 back
 to
 the
 

  or
 concepts
 covered
 in
  encountered
 with
  concepts
 covered
  Conclusion
 
the
 experiment;
  procedures
 that
  in
 the
 procedures
  statement
 consists
 
demonstrates
 an
  may
 have
 caused
  of
 the
 experiment.
  of
 a
 re-­‐cap
 of
 the
 
understanding
 of
 the
  errors
 in
 data
 or
 no
  (3-­‐6)
  experiment
 or
 is
 
concepts.
 Includes
  explanation
 of
  missing
 from
 the
 
possible
 sources
 of
 errors;
  potential
 sources
  Conclusion
 includes
  report.
 
 (0
 points)
 
recommendations
 for
  of
 errors.
 (6-­‐8
  results
 but
 does
 
alternate
 procedures
 to
  points)
  not
 tie
 results
 to
  Answers
 are
 
reduce
 error
 if
 applicable.
  objective
 of
  incorrect,
 
(8-­‐10
 points)
  Conclusion
  experiment.
 (2
  incomplete,
 or
 
statement
  points)
  missing
 for
 more
 
Conclusion
 statement
  summarizes
 the
  than
 50%
 of
 the
 
consists
 of
 a
 brief
  concept
 covered
 in
  Answers
 are
  questions..
 
summary
 of
 the
 results
  the
 experiment
 but
  incorrect,
  Report
 is
 poorly
 
and
 conclusions
 drawn
  does
 not
 include
  incomplete,
 or
  written
 and
 difficult
 
with
 respect
 to
 the
  results.
 
 (1
 point)
  missing
 for
 less
  to
 follow;
 includes
 
objective
 of
 the
  than
 25%
 of
 the
  insufficient
 detail,
 or
 
experiment.
 (3
 points)
  Answers
 are
  questions.
  contains
 sections
 
Correct
 answers
 that
  incorrect,
  Report
 includes
 all
  copied
 directly
 from
 
demonstrate
 an
  incomplete,
 or
  of
 the
 required
  the
 Lab
 manual.
 The
 
understanding
 of
 the
  missing
 for
 less
  sections
 but
 does
  narrative
 is
 not
 in
 
concepts
 for
 100%
 of
 the
  than
 10%
 of
 the
  not
 flow
 and
 is
  the
 3rd
 person
 and
 
questions.
 
  questions.
 
  confusing
 or
  there
 are
 several
 
difficult
 to
 follow
  grammatical
 and
 
Report
 is
 well-­‐written
  Report
 is
 easy
 to
  due
 to
 grammatical
  spelling
 errors.
 
 
using
 3rd
 person
 narrative,
  follow
 with
 few
  errors.
 Sentences
  Chemical
 formulae
 
is
 easy
 to
 follow,
 and
  grammatical
 or
  are
 not
 concise
  are
 incorrectly
 
flows
 nicely
 from
 one
  spelling
 mistakes
  and/or
 do
 not
  written.
 (0-­‐1
 points)
 
section
 to
 another.
 
 Data
  but
 chemical
  make
 sense.
 
 
is
 presented
 clearly
 in
  formulae
 are
  Narrative
 is
 not
 3rd
 
tables.
 There
 are
 few
  written
 incorrectly
  person
 or
 changes
 
grammar
 or
 spelling
  and/or
 3rd
 person
  within
 the
 report.
 
 
mistakes.
 
 Chemical
  narrative
 not
 used.
  Data
 and
 results
 
formulae
 are
 written
  (3-­‐4
 points)
 
  are
 not
 clearly
 
correctly
 with
 subscripts
  presented.
 (2-­‐3
 
and
 superscripts
 used
  points)
 
appropriately.
 (4-­‐5
 points)
 

ACP  Showcase  Por.olio


Name:
 
 Mary
 King,
 PhD
 
Discipline:
 
 Chemistry
 
Date:
 
 April
 28,
 2017
 

2
 

Table  of  Contents


•  Student
 PreparaAon
 Strategy
 
•  BOPPPS
 lesson:
 

•  CAT
 
•  QuesAons
 
•  Technology
 

•  ReflecAon
 

3
 

Describe  student  prepara;on  strategy


For
 2%
 of
 assignment
 grade,
 students
 will:
 

 
•  read
 Chapter
 17-­‐6
 &
 17-­‐7
 in
 the
 text
 book
 
•  Watch
 Haber
 process
 video
 (10
 min.):
 
 
hZps://www.youtube.com/watch?v=Tt6diRJli6Q
 

 
•  Explain
 how
 the
 Haber
 process
 uses
 Le
 Chatelier’s
 principle
 to
 affect
 

the
 equilibrium
 of
 the
 ammonia
 reacAon
 to
 obtain
 a
 greater
 yield.
 

4
 

BOPPPS  –  BRIDGE


A
 story
 about
 Joe
 and
 a
 discussion
 about
 the
 Haber
 Process
 will
 be
 used
 for
 the
 ‘Hook’
 

Joe
 owns
 a
 small
 pharmaceuAcal
  N2(g)
 
 +
 
 3H2(g)
 
 ⇌
 
 2NH3(g)
 
 
 ∆H⁰rxn
 =
 -­‐92
 kJ/mol
 

company
 in
 Georgia.
 In
 a
 Google
 patent
 

search,
 he
 noAced
 that
 the
 patent
 on
 a
 
popular
 drug
 was
 about
 to
 expire,
 and
 he
 

wanted
 to
 profit
 from
 commercializing
 it.
  •  The Haber process is used for the
But
 the
 synthesis
 yield
 of
 the
 drug
 was
  commercial production of

very
 low.
 
 Joe
 asked
 his
 lead
 chemist
 to
  ammonia (NH3).
determine
 the
 best
 way
 to
 improve
 the
 
yield
 of
 the
 drug.
 
 Ajer
 examining
 the
  •  It is an enormous industrial
steps
 involved
 in
 making
 the
 drug,
 the
  process in the US and many
other countries.
chemist
 recommended
 removing
 water,
 
which
 is
 a
 product
 in
 one
 of
 the
  •  fNeHrt3iliizsetrhperosdtaurctitniognm
  aterial for
equilibrium
 reacAon
 steps.
 
 This
 resulted
 
in
 triple
 the
 yield
 of
 the
 drug
 and
 Joe’s
 

company
 went
 on
 to
 make
 a
 large
 profit
 

on
 commercializing
 the
 drug
 by
 
implemenAng
 her
 recommendaAon.
 
 
 
5
 

BOPPPS  –  OBJECTIVES


By
 the
 end
 of
 this
 lesson,
 the
 student
 will
 be
 able
 to:
 

 
• 
 predict
 the
 effect
 of
 disturbing
 a
 system
 at
 equilibrium
 by
 changing
 

the
 concentraAon
 of
 both
 reactants/products,
 temperature,
 or
 
pressure
 of
 the
 system.
 
•  compare
 the
 reacAon
 quoAent,
 Q,
 to
 K
 in
 order
 to
 predict
 the
 
direcAon
 of
 shij
 in
 the
 reacAon
 to
 re-­‐
 establish
 equilibrium
 ajer
 a
 
system
 has
 been
 stressed
 
•  use
 the
 predicAon
 based
 on
 the
 Q
 comparison
 to
 set
 up
 ICE
 tables
 
and
 calculate
 the
 new
 equilibrium
 concentraAons
 

6
 

BOPPPS-­‐  PRE-­‐ASSESSMENT


•  Using
 the
 quiz
 I
 prepared
 in
 Poll
 Everywhere
 at
 
hZps://pollev.com/MARYKING818
 
 I
 will
 conduct
 a
 formaAve
 
assessment
 to
 determine:
 

•  If
 students
 can
 idenAfy
 the
 correct
 equilibrium
 expression
 (knowledge)
 
•  If
 students
 understand
 the
 concept
 of
 reversible
 reacAons
 

(comprehension)
 
•  How
 many
 of
 the
 students
 have
 an
 understanding
 of
 Le
 Chatelier’s
 

principle
 

7
 

BOPPPS-­‐  PARTICIPATORY  LESSON


Using
 the
 Reversible
 ReacAons
 PhET
 SimulaAon,
 students
 will:
 

 
• 
 Predict
 which
 of
 a
 set
 of
 possible
 outcomes
 is
 most
 likely
 to
 occur
 by
 

changing
 parameters
 (reacAon
 condiAons)
 in
 the
 PhET
 simulaAon.
 
 

•  Experience
 the
 simulaAon.
 Working
 in
 small
 groups,
 students
 will
 conduct
 
virtual
 experiments
 to
 determine
 whether
 their
 iniAal
 beliefs
 were
 
confirmed
 (or
 not).
 

•  Reflect
 on
 the
 outcomes.
 Students
 will
 think
 about
 their
 iniAal
 predicAons
 
and
 how
 the
 experiments
 confirmed
 or
 contradicted
 these
 predicAons.
 
 

8
 

BOPPPS-­‐  PARTICIPATORY  LESSON:  PhET  Simulator


9
 

BOPPPS-­‐  POST-­‐ASSESSMENT


If
 objecAves
 have
 been
 met,
 the
 student
 will
 be
 able
 to
 answer
 the
 following
 in
 a
 
summaAve
 assessment
 (Bloom’s
 taxonomy):
 


 

•  cWohmyp
 droehese
n  as
 cioanta) l
 yst
 not
 affect
 the
 equilibrium
 constant?
 (recall,
 knowledge,
 

•  What
 impact
 does
 temperature
 have
 on
 a
 system
 at
 equilibrium?
 (knowledge,
 
comprehension)
 

•  acFhonera
m l aynsiciysa
, il n
  s
 edynnugtsihtnreeiaseils r
 g)
 w
a   sh
 poh
 naeseed
 rse
 taoc
A  inocnr,e
 washea
 ht
e prr
a  ccoAmcpala
 onpy’Aso
 pnrso
 afirtea b
 aivliatyil?a
b  (klen
 otow
 ale
  dge,
 

•  iPmropvleidmee
 annA
 enxga
 Lmep
 Cleh
a  otfe
 ali
e  rre’asc
 pAroinnc
 wiphlee.r
 
e  (c
 tohme
p  prreohdeuncsti
 oyine,l
d sy
 cnatnh
e bsei s
 i)m
  proved
 by
 

•  (Pcroomvipdree
 phreonosfi o
 onf ,
 t
 ahnea
 ilmyspisr)o
 vement
 in
 product
 yield
 using
 equilibrium
 calculaAons
 


 
 

10
 

BOPPPS-­‐  SUMMARY


All
 concepts
 learned
 in
 this
 lesson
 lead
 to
 students’
 ability
 to
 solve
 this
 complex
 
equilibrium
 problem:
 

Ae0q.n6u
 a0ildimbdrioAiuloemns a
 hol a
 0fs.C
8  b0Oe
e mnao
n  rlede- ­
‐ oe0sf.
t2  Ca0lb2
l m iiss
h o aeldedd.eo
  df
C  tol2
 a.
C  2a.0lc0uLl
a  vtees
 sthele
 c
 noenwta
 minionlga r
 a
 cno
 enqcuenilitbrariAuomn
s m
 oixf
t  CuOre,

  C olf2
, 1
 a.2n0d
 CmOoClel2s
 ajoferC
  OCl2,

EASY
 AS:
 
 
  1
  2
  3
 
 

CO(g) + Cl2(g) !" COCl2(g) CO(g) + Cl2(g) !" COCl2(g)
0.10 M 0.60M
Equil.[]'s 0.30M 0.10M 0.60M Orig. Equil. 0.30M Q<Kc #shift right
[COCl2 ] (0.60) +0.40M
Kc = [CO][Cl2 ] = (0.30)(0.10) = 20 equation reduces to 20x2 !17x + 2.4 = 0

(Stress) Add

New Initial 0.30M 0.50M 0.60M X = 17 ± (!17)2 ! 4(20)(2.4) = 0.67 & 0.18
2(20)
Change -x M -x M +x M
limits are 0 < x < 0.30 thus we can discard 0.67
New Equil. (0.30-x)M (0.50-x)M (0.60+x)M
[CO]= (0.30 ! x)M = 0.12M
[COCl2 ] (0.60 + x)
Kc = [CO] [Cl2 ] = 20 = (0.30 $ x)(0.50 $ x) [Cl2 ]= (0.50 ! x)M = 0.32M
[COCl2 ]= (0.60 + x)M = 0.78M 11
 

Personal  Reflec;on  on  My  ACP  Experience


Some
 of
 the
 take-­‐away
 highlights
 for
 me:
 

Technology:
 
 

•  I
 am
 so
 empowered
 with
 all
 of
 the
 instrucAonal
 technology
 that
 I
 have
 been
 introduced
 to
 
in
 the
 ACP
 
 

•  I
 can’t
 wait
 to
 create
 my
 own
 exciAng
 and
 sAmulaAng
 presentaAons
 with
 visual
 chemistry
 
simulaAons!
 
 

Assessment
 strategies:
 
 
 

•  This
 has
 been
 such
 a
 struggle
 for
 me
 -­‐
 now
 I
 know
 how
 to
 create
 formaAve
 assessments
 
that
 benefit
 both
 me
 and
 the
 students
 (Plicker,
 Poll
 Everywhere,
 Kahoot,
 etc.)
 
 

Student
 ConnecAon:
 

•  The
 importance
 of
 building
 a
 class
 community
 with
 games
 and
 other
 group
 acAviAes
 and
 
to
 engage
 all
 students
 

THANK
 YOU
 CAROLINE
 
 

for
 such
 a
 great
 learning
 experience!
  12
 

Reflective Essay

As part of the application process for acceptance into the Adjunct Certification Program (ACP),
I was required to answer the question: “What are your short-term and long-term goals with
regards to improving your teaching? I answered with the following:

My short-term goal with regards to improving my teaching is to learn strategies to engage
proportionately more students during the lecture time. I want to try to present my course material
more effectively so that I can reach the masses. I don’t want to rely on offering bonus points as
a bribe to those who show up and answer questions, rather I want to be able to deliver the
material in a more exciting interactive format. My long-term goal is to quit my full-time job to
become a full-time teacher. But I feel that I first need to build an arsenal of resources and
strategies in order to have the confidence and self-assurance that I can be a more effective
educator. It is starting with this application for the Adjunct Certification Program offered by
Lonestar College!

I believe that I have exceeded my short-term goal objectives through the offerings of the ACP.
The ACP program and my fellow ACP classmates have introduced to me a plethora of resources
and strategies with which I can draw upon in order to create more stimulating and interactive
lessons. There is a vast expanse of information and instructional technologies that are available
on-line, and much of it is free! I will be experimenting with various classroom assessment
technologies such as Plickers, Kahoot, and Poll Everywhere to create fun, formative
assessments. These interactive polling apps are great tools that can be used to frequently
evaluate the effectiveness of my lesson delivery so that I can make adjustments as required. A
few of my students have told me that some of the best teachers they’ve had gave them a short
quiz at the start of every class. When students do a short quiz through one of these technologies,
they are rewarded with quick, anonymous feedback regarding their comprehension of the course
material as well as their relative standing among their fellow classmates. Another interactive
technology with instructional value that was introduced to me in the ACP classroom is interactive
virtual chemistry, which provides simulations of physical processes and chemical reactions that
can be used to demonstrate difficult concepts in chemistry. I plan to incorporate PhET Interactive
Simulations into both my classroom teaching and homework assignments.

In our ACP sessions, we discussed best practices and issues associated with summative
assessments. I was encouraged to know that many of my other ACP teacher classmates have
similar grading practices. For example, after grading an assessment, I will perform what
McKeachie refers to as an item analysis, whereby points associated with a question in which a
significant proportion of the class did not answer correctly are removed, and the grade is
adjusted accordingly. This fair grading practice is embraced by several of my ACP classmates
as well.

I also learned some great tips on writing multiple-choice questions, which I usually include as
part of my summative assessments. Now, I no longer include choices such as ‘none of the
above’ or have more than one correct choice, as recommended by McKeachie. Since that ACP
module, I have changed the way I compose my multiple-choice questions and the grades
seemed to have improved by about 25% (thus far).

Another interesting strategy I’ve learned in the ACP course was the value of changing up the
class with a game such as jeopardy, which injects a little fun into the lesson while reinforcing
concepts. I’ve learned that games can help to develop relationships between students and build
the classroom community for more productive group-work activities. Through ACP classroom
discussions and reading McKeachie’s book on teaching tips, I am much more aware of the
learning power of peer mentorship and group activities. I have started to build this into my lesson
by promoting student interactions and by inviting students to present their ideas to the class
when they express a special knowledge or interest in a particular topic. This has been well
received by my students, and has resulted in some interesting classroom discussions that might
not otherwise have happened.

Overall, the ACP program has been very beneficial for me in many ways. With my new arsenal
of resources, technologies and teaching tools, I now have the confidence to look toward my long-
term goal of becoming a full-time teacher. I am extremely grateful to Professor Caroline
Chamness for sharing her breadth of educational knowledge, and for preparing insightful and
interesting class discussions. I wish we could have had a few more classes… I also enjoyed
meeting and learning from other adjunct professors in the class. It would be most advantageous
to have professional development teaching workshops where both adjunct and full-time faculty
in attendance could have an opportunity to interact, share experiences, and network in much the
same way.


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