Kinetics Lesson Plan
Name: Sara Adamek
Class/Subject: AP Chemistry
Date: April 7-11, 2014
Student Objectives/Student Outcomes:
Objectives
Assessment
Students will be able to
Students will correctly determine the order of the reaction for each species.
determine the rate law of Students will correctly solve for k the reaction constant.
a reaction given
experimental data.
Students will be able to
Zero order graphs are straight lines of [A] vs t. m = -k
identify the graphs of
First order graphs are straight lines of ln[A] vs t. m= -k
zero, first and second
Second order graphs are straight lines of 1/[A] vs t. m = k
order reactions.
Students will be able to
Increasing the temperature will lead to an increase in the reaction constant and
predict and explain how rate because each molecule will have more energy which leads to increased
changes in reaction
collisions and increased likelihood that collisions will result in product.
conditions will affect the Increasing the concentration of one of the species that participates in the rate
reaction constant, and
law will increase the rate but not the reaction constant. This is because there
the rate.
is more chance of collisions happening.
Content Standards:
HS-PS1 Matter and its Interactions
Students who demonstrate understanding can:
HS-PS1-5.
Apply scientific principles and evidence to provide an explanation
about the effects of changing the temperature or concentration of the
reacting particles on the rate at which a reaction occurs.
Materials:
n/a
Time ( conceptual background)
Start of Class:
Take attendance. Listen to announcements.
Introduction of Lesson:
Ask students to take out their notebooks. Ask why do reactions happen? Discuss and lead in
to note taking.
Lesson Instruction:
Lecture using hand written notes.
Assessment/Checks for understanding:
Write a paragraph explaining, activation energy’s role in reactions and the three ways you
could increase the produce yield. Be sure to explain why the yield is increased with each
method. Grade for completion
Closure/Wrap-up/Review:
Have one or two students read and discuss their answers.
Materials/Resources/Technology:
ppt with data, projector
Time (Rate laws)
Start of Class:
Take attendance. Listen to announcements.
Introduction of Lesson:
Ask students to get out their notebooks. Review what was discussed yesterday.
How do reactions happen? (collision model, Ez and orientation)
How to increase reaction rate? (Increase temp. or conc. Or add a catalyst.)
Why do each of these work? (Increase K.E. Increase # of collisions, lower Ea)
Lesson Instruction:
Lecture using hand written notes.
Release students to work on problems.
Assessment/Checks for understanding:
p. 592 Zumdahl #19-28
Closure/Wrap-up/Review:
Work a problem with students/answer questions brought up by working on the problems.
Materials/Resources/Technology:
Time (Intgrated rate law, graphs and half life)
Start of Class:
Take attendance. Listen to announcements.
Introduction of Lesson:
Ask students to get out their notebooks. Review what was discussed yesterday.
How do reactions happen? (collision model, Ez and orientation)
How to increase reaction rate? (Increase temp. or conc. Or add a catalyst.)
Why do each of these work? (Increase K.E. Increase # of collisions, lower Ea)
Lesson Instruction:
Lecture using hand written notes.
Release students to work on problems
Assessment/Checks for understanding:
Zumdahl: TBD
Closure/Wrap-up/Review:
Work a problem with students/answer questions brought up by working on the problems.
Materials/Resources/Technology:
Time ( ½ life and rxn mechanisms)
Start of Class:
Take attendance. Listen to announcements.
Introduction of Lesson:
Review rate law, integrated rate law. We can use the integrated rate law to find the formula
to determine the half life of a reaction.
Lesson Instruction:
Lecture using hand written notes.
Release students to work on problems
Assessment/Checks for understanding:
p. 595 Zumdahl #45-48 (Check)
p. 597 Zumdahl #59-62 Collect HW on Monday. Check for completion.
Closure/Wrap-up/Review:
Work a problem with students/answer questions brought up by working on the problems.
Materials/Resources/Technology:
Time (AP questions)
Start of Class:
Take attendance. Listen to announcements.
Introduction of Lesson:
Pass out problems.
Lesson Instruction:
Assist students in working on the problems.
Assessment/Checks for understanding:
Problems will be checked for compleation. Feedback will be given.
Closure/Wrap-up/Review:
N/A
Integrated rate law practice
Name: _____________
1. In decomposition of hydrogen peroxide was studied, and the following data were obtained at a
particular temperature:
[H2O2]
0
120
300
600
1200
1800
2400
3000
3600
1
0.91
0.78
0.59
0.37
0.22
0.13
0.082
0.05
Decomposition of
hydrogen peroxide
25
20
1/[H2O2]
Time
15
10
5
0
0
1000
2000
3000
4000
time (s)
Decomposition of
hydrogen peroxide
Decomposition of
hydrogen peroxide
1.2
0
-0.5 0
0.8
0.6
0.4
0.2
2000
-1.5
-2
-2.5
0
-3
0
1000
2000
3000
4000
Time (s)
Assuming that Rate = -Δ[H2O2]/Δt:
a.
b.
c.
d.
1000
-1
ln[H2O2]
[H2O2]
1
Determine the rate law.
Determine the integrated rate law.
Determine the value of the rate constant.
Calculate the [H2O2] at 4000s.
-3.5
Time (s)
3000
4000
The rate of the reaction
NO2 + CO  NO + CO2
depends only on the concentration of nitrogen dioxide below 225°C. At a temperature below
225°C the following data were collected.
Time
[NO2]
0.5
0.444
0.381
0.34
0.25
0.174
0
1.20E+03
3.00E+03
4.50E+03
9.00E+03
1.80E+04
Consumption of NO2
0.6
0.5
0.4
[NO2]
2.
0.3
0.2
0.1
0
0
5000
10000 15000 20000
Time (s)
Consumption of NO2
Consumption of NO2
0
7
0
5000
10000 15000 20000
6
5
1/[NO2]
Ln(NO2)
-0.5
-1
4
3
2
1
-1.5
0
-2
a.
b.
c.
d.
0
Time (s)
5000
10000
15000
Time (s)
Determine the rate law.
Determine the integrated rate law.
Determine the value of the rate constant.
Calculate the concentration of NO2 at 2.70 x 104s after the start of the reaction.
20000
KINETICS REVIEW QUESTIONS
1. Fill out the chart below.
Zero Order
Rate Law
Name: __________________
First Order
Second Order
Integrated rate
law
____ vs ___
gives a straight
line
Slope of
straight line
Half life eqn.
Use the following information to answer questions 2-5.
A multi step reaction takes place with the following elementary steps:
Step 1. A + B  C
Step 2. C + A  D
Step 3 C + D  B + E
2. What is the overall balanced equation for this reaction?
3. What is the function of specie B in this reaction?
a. Without it, no reaction would take place
b. It is a reaction intermediate with facilitates the progress of the reaction.
c. It is a catalyst which changes the overall order of the reaction.
d. It lowers the overall activation energy of the reaction.
4. If step 2 is the slow step for the reaction, what is the overall rate law?
a. Rate = k[A]2[C]
b. Rate = k [A][C]
c. Rate = k [A][B]
d. Rate = k [A] / [D]
5. Why would increasing the temperature make the reaction rate go up?
a. It is an endothermic reaction that needs an outside energy source to function?
b. The various molecules in the reactions will move faster and collide more often.
c. The overall activation energy of the reaction will be lowered.
d. A higher fraction of molecules will have the same activation energy.
6.
A + B  C rate = k [A]
Under which condition would the order of the above reaction double?
a.
b.
c.
d.
Doubling the initial concentration of A
Doubling the initial concentration of B
Reducing the concentration of A by half
Changing the concentration has no effect on reaction order
7. A multistep reaction takes place by the following mechanism:
A+BC+D
A+CD+E
Which of the species shown above is an intermediate in the reaction?
a. A
b. B
c. C
d. D
8. H2(g) + I2(g)  2 HI(g)
Rate = k [H2][I2]
The reaction given above takes place in a sealed isothermal container. If a mole of H2 gas is added to the
reaction chamber, which of the following will be true?
a.
b.
c.
d.
The rate of reaction and the rate constant will increase.
The rate of reaction and the rate will not change.
The rate of reaction will increase and the rate constant will decrease.
The rate of reaction will increase and the rate constant will not change.
A+BC
9.
Rate = k [A]
If the temperature of the reaction chamber were to increase, which of the following would be true?
a.
b.
c.
d.
The rate of reaction and the rate constant will increase.
The rate of reaction and the rate will not change.
The rate of reaction will increase and the rate constant will decrease.
The rate of reaction will increase and the rate constant will not change.
10. After 44 minutes, a sampler of 44
19𝐾 is found to have decyated to 25 percen of the original amount
present. What is the half life of 44
19𝐾 ?
a. 11 minutes
b. 22 minutes
c. 44 minutes
d. 66 minutes
Constructed Response:
1. A + 2 B  2 C
The following results were obtained in experiments designed to study the rate of the reaction
above:
Experiment Initial Concentration (mol/L)
Initial rate of
disappearance of A
[A]
[B]
(M/sec)
1
0.05
0.05
3.0 x 10-3
2
0.05
0.10
6.0 x 10-3
3
0.10
0.10
1.2 x 10-2
4
0.20
0.10
2.4 x 10-2
(a) Determine the order of the reaction with respect to each of the reactants, and write the rate
law for the reaction.
(b) Calculate the value of the rate constant k, for the reaction. Include the units.
(c) If another experiment is attempted with [A] and [B], both 0.02 M, what with tbe th initial
rate of disappearance of A?
(d) The following reaction mechanism was proposed for the reaction above:
A+BC+D
D+BC
(i) Show that the mechanism is consistent with the balanced reaction.
(ii) Show which step is the rate determing step, and explain your choice.
2. N2O5 (g)  4 NO2 (g) + O2 (g)
Dinotrogen pentoxide gas decomposes according to the equation above. The first-order reaction was
allowed to proceed at 40°C and the data below were collected.
[N2O5] M
0.400
0.289
0.209
0.151
0.109
Time (min)
0.0
20.0
40.0
60.0
80.0
(a) Calculate the rate constant for the reaction using the values for concentration and time given in
the table. Include units in your answer.
(b) After how many minutes will [N2O5] be equal to 0.350M?
(c) What will be the concentration of N2O5 after 100 minutes have elapsed.
(d) Calculate the initial rate of the reaction. Include units with your answer.
(e) What is the half-life of the reaction?
3. Use your knowledge of kinetics to answer the following questions. Justify your answers.
(a) Which of the two graphs show the changes in concentration ofver time for the reaction
below?
A B
(b) Which of the two lines in the diagram above shows the relationship of ln[A] to time for a first
order reaction with the following rate law? Rate = k [A]
(c) The two line in the diagram above show differen reaction pathways for the same reaction.
Which of the two lines shows the reaction when a catalyst has been added?
(d) Which of the two lines in the energy distribution diagrm shows the conditions at a higher
temperature?
1
Potentia
l Energy
2
Reaction coordinate