three gas laws in sch3u

Three Gas Laws in Three Gas Laws in SCH3USCH3U

Presenter: Joy McCourtPresenter: Joy McCourtMentor: Nick FoxMentor: Nick Fox

Aaaaahh, Gas Aaaaahh, Gas Laws…Laws…

Don’t they just make you Don’t they just make you feel like…feel like…

……SINGING???SINGING???

OutlineOutlineCurriculum ExpectationsCurriculum Expectations

Position of Unit in Course; Position of Concepts in UnitPosition of Unit in Course; Position of Concepts in Unit

Hands-On PossibilitiesHands-On Possibilities

Suggested Lesson SequenceSuggested Lesson Sequence

Societal ApplicationsSocietal Applications

Safety concernsSafety concerns

Misconceptions and Student DifficultiesMisconceptions and Student Difficulties

Challenging/Supporting Different Levels of ClassesChallenging/Supporting Different Levels of Classes

Supporting Different Kinds of LearnersSupporting Different Kinds of Learners

ReferencesReferences

Curriculum ExpectationsCurriculum Expectations

Overall:Overall:

F2. investigate gas laws that explain F2. investigate gas laws that explain the behaviour of gases, and solve the behaviour of gases, and solve related problems;related problems;

F3. demonstrate an understanding of F3. demonstrate an understanding of the laws that explain the behaviour of the laws that explain the behaviour of gases.gases.


SpecificSpecific::

Inquiry:Inquiry:

F2.2 determine, through F2.2 determine, through inquiryinquiry, the , the quantitative and graphical relationships quantitative and graphical relationships between the pressure, volume, and between the pressure, volume, and temperature of a gas [PR, AI]temperature of a gas [PR, AI]

F2.3 solve quantitative problems by F2.3 solve quantitative problems by performing performing calculations calculations based on Boyle’s based on Boyle’s law, Charles’s law, Gay-Lussac’s law, the law, Charles’s law, Gay-Lussac’s law, the combined gas law, Dalton’s law of partial combined gas law, Dalton’s law of partial pressures, and the ideal gas law [AI]pressures, and the ideal gas law [AI]


Knowledge and Understanding:Knowledge and Understanding:

F3.4 F3.4 describedescribe, for an ideal gas, the , for an ideal gas, the quantitative relationships quantitative relationships that exist that exist between the variables of pressure, between the variables of pressure, volume, temperature, and amount of volume, temperature, and amount of substancesubstance

F3.5 F3.5 explain explain Dalton’s law of partial Dalton’s law of partial pressures, pressures, Boyle’s law, Charles’s law, Boyle’s law, Charles’s law, Gay-Lussac’s lawGay-Lussac’s law, the combined gas law, , the combined gas law, and the ideal gas lawand the ideal gas law

Position of Unit in CoursePosition of Unit in Course

What are the pros and cons of What are the pros and cons of startingstarting the course with the gas the course with the gas laws unit?laws unit?


My rationale for trying it this way last My rationale for trying it this way last year:year:

STAO ScienceWorks workshop on STAO ScienceWorks workshop on SCH3U*—successfully used by othersSCH3U*—successfully used by others

realistic picture of the course at the realistic picture of the course at the beginning—math and logic are required! beginning—math and logic are required! (& gets a hard unit out of the way) (& gets a hard unit out of the way)

*at STAO conference in November 2006


““more gas in = bigger balloon” makes more gas in = bigger balloon” makes sense to students—very natural sense to students—very natural introduction to the moleintroduction to the mole

Avogadro’s hypothesis arose from Avogadro’s hypothesis arose from studying gas-state reactions.studying gas-state reactions.

Worked for me. Worked for me.

Your mileage may vary.Your mileage may vary.(This picture should bother you…)

Position of Concepts in Position of Concepts in UnitUnit

If you do start with this If you do start with this unit…unit…

Introductory Introductory information:information:

Math basics: Math basics: significant figures, significant figures, rearranging rearranging equationsequations

Using conversion Using conversion factors: pressure factors: pressure unit conversionsunit conversions


States of Matter (how particle speed, States of Matter (how particle speed, types of motion, & forces between types of motion, & forces between particles affect their properties)particles affect their properties)

How pressure affects volume (Boyle’s How pressure affects volume (Boyle’s Law)Law)

How temperature affects volume and How temperature affects volume and pressure (Charles’ Law, Gay-Lussac’s pressure (Charles’ Law, Gay-Lussac’s Law*)Law*)

*or, in Nelson, “the pressure-temperature law”


The combined gas law (easy)The combined gas law (easy)

Dalton’s Law (hard?); composition of Dalton’s Law (hard?); composition of the atmosphere the atmosphere (later in some texts)(later in some texts)


How the amount of gas affects volume, How the amount of gas affects volume, pressure, and temperature (the ideal pressure, and temperature (the ideal gas law…and the mole!)gas law…and the mole!)

Mass-volume connections (using “The Mass-volume connections (using “The Mole Highway” or “The Y Diagram”)—Mole Highway” or “The Y Diagram”)—including “The SCH3U Lighter Lab”! including “The SCH3U Lighter Lab”! (see posted Best Practice)(see posted Best Practice)

Overall STSE connection: air qualityOverall STSE connection: air quality

I address gas stoichiometry by coming back to these ideas as part of the unit on quantities in chemical reactions.


Play Time!Play Time!

Guided activities to come up with Guided activities to come up with explanations / relationships explanations / relationships between the variables involved...between the variables involved...

……qualitative experiences to qualitative experiences to associate with concepts and use associate with concepts and use to understand new situations.to understand new situations.


Quantitative:Quantitative:

2001 course text by McGraw-Hill Ryerson:2001 course text by McGraw-Hill Ryerson:C-clamp, ruler + sealed plastic pipette C-clamp, ruler + sealed plastic pipette Boyles’ Law Boyles’ LawWater bath, ruler, thermometer + Water bath, ruler, thermometer + sealed plastic pipette sealed plastic pipette Charles’ Law Charles’ Law (similar, but more advanced, method (similar, but more advanced, method in Rockley & Rockley (1995))in Rockley & Rockley (1995))

Vernier probeware: Boyle’s Law Vernier probeware: Boyle’s Law (tomorrow’s workshop)(tomorrow’s workshop)


Purchase various sets of apparatus Purchase various sets of apparatus available on the marketavailable on the market


For overhead use:

Suggested Lesson Suggested Lesson SequenceSequence

(refer to handout)(refer to handout)


Gas cylinder safety (helium tanks, welding Gas cylinder safety (helium tanks, welding equipment, etc.) equipment, etc.)

Compressed Gas Cylinder Training Video - Missile Compressed Gas Cylinder Training Video - Missile Hazard Hazard

((http://www.youtube.com/watch?v=pe9gYRXQTTY))

MythBustersMythBusters

((http://www.youtube.com/watch?v=ejEJGNLTo84))

Occupations and situations that use Occupations and situations that use compressed gases (anesthesia, water compressed gases (anesthesia, water treatment, etc.)treatment, etc.)

http://www.youtube.com/watch?v=pe9gYRXQTTY

http://www.youtube.com/watch?v=ejEJGNLTo84


Popcorn, and some aspects of rising Popcorn, and some aspects of rising doughdough

Hot air ballooningHot air ballooning

““The bends” (diving)The bends” (diving)

Speaking of Safety…Speaking of Safety…

The main safety concerns when studying The main safety concerns when studying this unit have to do with:this unit have to do with:

Pressurized gasesPressurized gases

High temperaturesHigh temperatures

Electrical safety when using hot plates and Electrical safety when using hot plates and probesprobes

Fire concerns when using Bunsen burners Fire concerns when using Bunsen burners (e.g., to seal plastic pipettes)(e.g., to seal plastic pipettes)

Fumes created while sealing plastic Fumes created while sealing plastic pipettespipettes

Taking care not to break thermometersTaking care not to break thermometers

Misconceptions andMisconceptions andStudent DifficultiesStudent Difficulties

Difficulty: Gay-Lussac’s LawDifficulty: Gay-Lussac’s Law

……or rather, getting past its name.or rather, getting past its name.


Solutions:Solutions:

Model not being tripped up by its name.Model not being tripped up by its name.

If discomfort arises, make sensitive use If discomfort arises, make sensitive use of this “teachable moment.”of this “teachable moment.”


Solutions:Solutions:

2002 Nelson textbook calls it “the pressure-2002 Nelson textbook calls it “the pressure-temperature law.”temperature law.”

Rationale: “history of science references say Rationale: “history of science references say that Charles, Dalton and Gay-Lussac were all that Charles, Dalton and Gay-Lussac were all involved in investigating this relationship, involved in investigating this relationship, with Charles and Dalton doing their work with Charles and Dalton doing their work before Gay-Lussac” (p. 435).before Gay-Lussac” (p. 435).

Considered for very immature classes (at the Considered for very immature classes (at the cost of some science history and an cost of some science history and an opportunity for dialogue).opportunity for dialogue).


Difficulty: Which law? / What kind of Difficulty: Which law? / What kind of change?change?

From Horton (2007): “For example, From Horton (2007): “For example, Herbert Beall (1994) lectured college Herbert Beall (1994) lectured college freshmen on the second law of freshmen on the second law of thermodynamics and the ideal gas laws. thermodynamics and the ideal gas laws. After the lecture only 11% were able to After the lecture only 11% were able to correctly predict the effect that opening correctly predict the effect that opening a cylinder of compressed gas would have a cylinder of compressed gas would have on the temperature of the gas.”on the temperature of the gas.”


Solution:Solution:

Hands-on examples -- “hooks” on which to Hands-on examples -- “hooks” on which to hang the concepts and relate to new hang the concepts and relate to new situations.situations.

Practice examining units and descriptions Practice examining units and descriptions for cluesfor clues

GRASP method (see previous presentations):GRASP method (see previous presentations):

What are you given? What are you asked to What are you given? What are you asked to find? Which equation relates those find? Which equation relates those quantities?quantities?


Difficulty: visualizing the molecular Difficulty: visualizing the molecular levellevel

Solution 1: put it in real-world terms.Solution 1: put it in real-world terms.

Example: Jumpy, energetic dancers Example: Jumpy, energetic dancers dancing to fast-paced music vs. dancers dancing to fast-paced music vs. dancers doing a slow dance.doing a slow dance.


Solution 2: simulators (demo or Solution 2: simulators (demo or worksheet-guided computer lab)worksheet-guided computer lab)

http://www.chem.ufl.edu/~itl/2045/MH_sims/gas_sim.html

http://intro.chem.okstate.edu/1314f00/laboratory/glp.htm






Difficulty rearranging equations Difficulty rearranging equations

May know how to handle + / - but not May know how to handle + / - but not × / ÷× / ÷

May not know how to handle + / - , May not know how to handle + / - , either; may only solve for x by using either; may only solve for x by using guess-and-check. guess-and-check.


Solution:Solution:

Patience, modeling, practice.Patience, modeling, practice.

““opposite” operations: “PV” means opposite” operations: “PV” means the P is the P is multiplyingmultiplying the V…must the V…must dividedivide both sides by P to get V. both sides by P to get V.

Build from easier examples: can you Build from easier examples: can you solve 3x = 12?solve 3x = 12?

See student’s math teachers for any See student’s math teachers for any insight.insight.

Challenging/SupportingChallenging/SupportingDifferent Levels of Different Levels of

ClassesClassesReady for a ChallengeReady for a Challenge

Take them through Take them through the full work-up of the full work-up of each law, including each law, including the use of the use of proportionality proportionality constantsconstants

Need More SupportNeed More Support

Help them to Help them to connect what we connect what we expect in the real expect in the real world and the form world and the form of the relevant of the relevant equation; use ratiosequation; use ratios

€

P1V1 =P2V2

P1P2

V1 =V2

If P1 > P2, then…

, so

€

V ∝ T

V =kT

k =VT

=V1

T1

=V2

T2

Challenging/SupportingChallenging/SupportingDifferent Levels of Different Levels of

ClassesClassesReady for a ChallengeReady for a Challenge

Less scaffolding / Less scaffolding / fewer supports in fewer supports in questionsquestions

Expect more detailed Expect more detailed explanations of the explanations of the microscopic levelmicroscopic level

Expect them to explain Expect them to explain why all three variables why all three variables are actually involved are actually involved in a situationin a situation

Need More SupportNeed More Support

Teach careful work Teach careful work through Predict-GRASP-through Predict-GRASP-Check or a similar Check or a similar strategystrategy

Teach them to make a Teach them to make a common-sense common-sense prediction first, then prediction first, then check their calculated check their calculated answer against their answer against their predictionprediction

Fewer questions / extra Fewer questions / extra time.time.

Supporting Different Supporting Different KindsKinds

of Learnersof LearnersVisual/Spatial learners:Visual/Spatial learners:

microscopic picture may be easier for microscopic picture may be easier for themthem

again, check the reasonableness of again, check the reasonableness of answers by considering real-world answers by considering real-world examples they’ve seen.examples they’ve seen.


of Learnersof LearnersLinguistic intelligence:Linguistic intelligence:

Reading style: assigned readings from Reading style: assigned readings from the text to consolidate in-class learningthe text to consolidate in-class learning

Writing style: should summarize (in Writing style: should summarize (in writing) readings and hands-on work; writing) readings and hands-on work; write notes/fill in blanks during lectures.write notes/fill in blanks during lectures.


of Learnersof LearnersLinguistic intelligence:Linguistic intelligence:

Auditory style: listen more and take Auditory style: listen more and take notes less during lecture (but should notes less during lecture (but should take some)take some)

Verbal: “talking through” practice Verbal: “talking through” practice problems with a partner or the teacher.problems with a partner or the teacher.


of Learnersof LearnersInterpersonal learners: also “talking Interpersonal learners: also “talking through” practice problems with a through” practice problems with a partner or the teacherpartner or the teacher

Kinesthetic learners: hands-on learningKinesthetic learners: hands-on learning


of Learnersof LearnersLogical-mathematical Logical-mathematical students:students:

will likely find the will likely find the calculations easier calculations easier than classmatesthan classmates

if not Visual, talk if not Visual, talk through the logic through the logic of the simulations of the simulations with them until with them until they can reason they can reason their way through their way through microscopic microscopic situations. situations.


of Learnersof LearnersMusical:Musical:

Challenge them to write a song to Challenge them to write a song to remember the laws (but they can only sing remember the laws (but they can only sing it in their heads during quizzes it in their heads during quizzes ))

Allow musical final products in some Allow musical final products in some assignments.assignments.

Today’s intro was fromToday’s intro was from

http://www.youtube.com/watch?v=Hbb9dGmU0r0




of Learnersof LearnersNaturalistic learners: connections to Naturalistic learners: connections to everyday occurrences, such as popcorn everyday occurrences, such as popcorn and breathingand breathing

Intrapersonal intelligence…how can Intrapersonal intelligence…how can these learners best be supported, other these learners best be supported, other than by allowing them to work than by allowing them to work independently (a strategy that doesn’t independently (a strategy that doesn’t actually connect to self-knowledge)???actually connect to self-knowledge)???

ReferencesReferencesOntario Science curriculum (2008 revision)Ontario Science curriculum (2008 revision)

STAO ScienceWorks SCH3U workshopSTAO ScienceWorks SCH3U workshop

Horton, C. (2004). Student Misconceptions and Horton, C. (2004). Student Misconceptions and Preconceptions in ChemistryPreconceptions in Chemistry. California Journal of . California Journal of Science Education, 7Science Education, 7 (2), 1531-2488. (2), 1531-2488.

Jenkins, Frank, et al. (2002). Jenkins, Frank, et al. (2002). Chemistry 11Chemistry 11. . Toronto: Nelson.Toronto: Nelson.

Mustoe, Frank, et al. (2001). Mustoe, Frank, et al. (2001). Chemistry 11Chemistry 11. . Toronto: McGraw-Hill Ryerson.Toronto: McGraw-Hill Ryerson.

Rockley, Natalie L. (1995). A Charles’ Law Rockley, Natalie L. (1995). A Charles’ Law Experiment for Beginning Students. Experiment for Beginning Students. Journal of Journal of Chemical EducationChemical Education, , 7272 (2), 179-181 (2), 179-181

three gas laws in sch3u

Documents

gas laws unit

charless law

gas lawsdont

coursemore gas

gas pr

pressure charles law

ideal gas lawposition

gaylussacs law