TITLE
OF LESSON: Introduction to Ideal Gas Law Relationships
LENGTH
OF LESSON: 50 minutes
NAME
OF COURSE: Chemistry
GRADE
LEVEL: High School
SOURCE
OF THIS LESSON:
Pressure
Chamber. < http://jersey.uoregon.edu/vlab/Piston/
McBane,
George. Gas Laws. <http://www.chemistry.ohio-state.edu/betha/nealGasLaw/index.html>
TEKS
ADDRESSED:
(7) Science concepts. The student knows the
variables that influence the behavior of gases. The student is expected to:
(A) describe interrelationships among temperature, particle number, pressure, and volume of gases contained within a closed system; and
PERFORMANCE
OR LEARNER OUTCOMES:
Students
will be able to:
¤
Understand relationship
between variables (Pressure and Volume at Constant Temp)
¤
State the assumptions
made by the ideal gas law and explain why they are being made
¤
Find the answer to an
ideal gas problem
RESOURCES,
MATERIAL AND SUPPLIES NEEDED:
¤
Computers with internet
connections
SUPPLEMENTARY
MATERIALS, HANDOUTS:
¤
None (have students
answer experimental questions in their lab notebook)
LESSON PLAN
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Engagement: Give brief review of gasses using the following website: http://www.chemistry.ohio-state.edu/betha/nealGasLaw/index.html |
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Exploration: Have students explore http://jersey.uoregon.edu/vlab/Piston/ and complete each experiment. |
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Explanation: Discuss answers to each experiment. |
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Elaboration: The ideal gas law is not
perfect. It makes a lot of assumptions that are not actually true. It
assumes: ¤
Molecules take up no
space ¤
No forces
(attractive/repulsive) between molecules ¤
Elastic collisions with walls |
Is this true? Is this a good approximation? Why or why
not? Is this true? Is this a good approximation? Why or why
not? Is this true? Is this a good approximation? Why or why
not? |
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Evaluation: |
An automobile is driven by
chemical reactions which can be reasonably modeled by the combustion of
octane. It takes about one mole of octane to move a car one mile. What volume of oxygen at 300K and 1.00 atm is required to react with one
mole of octane according to the reaction given below? 2 C8H18 + 25 O2
-> 16 CO2 + 18 H2O
What volume of air is required, given that air is 21% oxygen? |
Solution step 1: From the reaction stoichiometry, 25/2 moles of
oxygen are required to burn one mole of octane. Solution step 2: Determine the volume of 25/2 moles of oxygen at
300K and 1.00 atm. Solution step 3: Determine the volume of air required. |