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Gas Law Unit Plan OutlineYimin Tang

Date Lesson NSTA Standards Virginia SOLs Activities AssessmentDay 1 Property of Gas

PressureNSTA 3a CH. 5 a Heavy newspaper

Anti-gravity waterInverse test tube

Day 2 Boyle’s Law NSTA 1a, 6a CH. 5 b Holes in a bottle demonstrationSucking water through a strawCartesian diver experiment

Activity Sheet

Day 3 Absolute zero and temperatureconversion

NSTA 3a CH. 5 a Absolute zero videoSuperfluid video

Worksheet

Day 4 Charles’ Law NSTA 1a, 6a CH. 5 b Pingpong ball recoveryDemonstrationSyringe in water bath experiment

Activity sheet

Day 5 Gay-Lussac’sLaw

NSTA 1a, 6a CH. 5 b Tire explosion exampleSteam engine video

Homework

Day 6 Combined GasLaw 1

NSTA 1a, 6a CH. 5 b Avogadro’s hypothesisTED gas property video

Homework

Day 7 Combined GasLaw 2

NSTA 1a, 6a CH. 5 b Phet simulation Activity sheet

Day 8 Ideal Gas Law 1 NSTA 1a, 6a CH. 5 b Lecture & Notes Activity SheetDay 9 Ideal Gas Law2 NSTA 1a,b,c CH. 5 b Bell jar & vacuum pump

experimentActivity sheet

Day 10 Dalton’s Lawof PartialPressure 1

NSTA 1a, 6a CH. 5 b Lecture & Notes PracticeProblems

Day 11 Dalton’s Lawof PartialPressure 2

NSTA 1a, 6a CH. 5 b Butane gas experiment Activity Sheet

Day 12 Gas Law Test NSTA 1a,b,c2c, 3b, 4b

CH. 5 a, b Test Test

Unit Plan Reflection

I believe I have achieved the NSTA standards 1a-c, 2c, 3b, 4b, 6a-b, 7b, 8a through the unit plan I have created on gas laws, which includes Boyle’s law, Charles’ law, Gay-Lussac’s law, combined gas law, ideal gas law, and Dalton’s law of partial pressure

The unit plan I have made suited my students’ zone of proximal development. 5-E learning model is an efficient way to plan and teach lessons. It is so important to engage students at the beginning of a class period instead of putting the interesting phenomenon in the middle of a lecture, when students are much less likely to concentrate on what is being taught. Whenever I perform a demonstration which contradictory to their belief, or when I bring up an interesting topic they never think of, students are extra focused and excited for my explanation, so that I can introduce and lecture the new concepts very effectively.

Students need hands-on experience to explore possible answers to the contradictory engaging demonstrations. I always try to invoke students to think critically and analyze what they’ve experience. Exploration stage in 5-E model serves this purpose very well. Students also need to apply their knowledge on experiments after the explanation stage so that the knowledge would not just be a formula or definition; it would come alive as and be relevant to students’ lives. Experiments are not meant for students to just follow step and record data; they meant to aid students synthesize knowledge stored in memory and apply them. When I am designing a lab, I always make sure that the activity sheet would guide students to think critically by asking in-depth analysis questions.

During the explanation stage, I always make inclusive Power point slides to show detailed diagram so that in-depth analysis and explanation is made possible. I lecture new concepts mostly though Power point slides since they are essential to provide students visual aids: I would list important points they need to take notes of; I would make it rich in graphic including pictures, diagrams and animations which is application of concepts in an engaging way; Power point slides are also a reminder for me to ensure I have conveyed all ideas I am supposed to. Students find Power point slides helpful, neat and engaging too. I always make sure that my students can relate the knowledge to something they know of, so that the lesson would not be abstract and far from reach for them. I use real-life example, simile and experiments to make knowledge applicable and accessible to them.

I have incorporated multiple types of assessments in my unit plan. The most frequent and informal way of assessment is checking on everybody’s progress after I have explained a concept and let them work on a practice problem. I would patrol around the classroom to see if they have grasped the fundamental skill. I have utilized, collected and graded worksheet, homework, lab/activity sheet to evaluate their understanding. Homework is great way to have students practice, check their progress and solidify their newly-learned concepts, which is also a valuable resource to inform me as to how well students grasp the knowledge. Worksheets are meant to be finished in class, so that students can have immediate one-on-one assistance from the teacher if

they encounter any question, which is a great way for student-and-teacher interaction. Lab/ activity sheets guide and encourage students’ thinking on top of instructing them as to how to set up and operate equipment.

Day 1: Property of Gas Pressure Purpose of StudyStudents are going to learn about the characteristics of gas pressure and volume through teacher’s demonstration and interactive experiments, which knowledge are the foundation for the further study of gas laws.

SOLs CH.5 The student will investigate and understand that the phases of matter are explained by kinetic theory and forces of attraction between particles. Key concepts includea) pressure, temperature, and volume;

Materials and ResourcesTest tubesWaterContainersIndex cardsSmart boardNotebook

Safety IssuesSafety goggles need to be worn when experimenting.

Procedures:Engage

1. Prompt students to reason real-life scenarios regarding pressure and volume for example, balloon would burst at certain altitude. There is about 1,000kg or 2200lbs of air pressure on our body, which is approximately the same as having a small car pressing down on us. (5 minutes)

Explore (Anti-gravity water experiment)2. Each student will be asked to submerge a test tube under a water bath, and then pull the test tube

up from the surface of water with the open end down at different heights. (10 minutes)

Explain 3. Students would explain the phenomenon using graphs, diagrams, words, or etc. on a piece of

paper. Teacher would give PPT notes on the property of gas pressure. (20 minutes)

Elaborate (Inverse test tube experiment)

4. Each student will be given an index card to cover a test tube full of water, and then turn the test tube upside down to observe what would happen. Students would explain the phenomenon using graphs, diagrams, words, or etc. on a piece of paper. (15 minutes)

Evaluate5. Teacher would go around and check students’ understanding and ask them to reason the

experimental phenomena.

Day 2: Boyle’s LawPurpose of StudyStudents are going to learn about the Boyle’s Law following the 5-E learning model in a 50-minute class. Students will learn pressure and volume are inversely proportional to each other when temperature and amount of gas is fixed.

SOLs CH.5 The student will investigate and understand that the phases of matter are explained by kinetic theory and forces of attraction between particles. Key concepts includeb) partial pressure and gas laws;

Materials and ResourcesStrawsSoda bottlesFastener nutsPlastic droppersWaterSmart boardActivity sheet

Safety IssuesStudents cannot suck the water through straw using mouth.

Procedures:Engage

1. Teacher would perform holes in a bottle demonstration: water would leak through the holes however, after capping the bottle up, water would stop leaking. (5 minutes)

Explore 2. Student would transfer water using a straw: each student would insert a straw into a tub of water

and put thumb tightly onto the open end of straw, then list the straw up away from the beaker without loosening up the thumb on the straw. (10 minutes)

Explain 3. Students would explain the phenomenon using graphs, diagrams, words, or etc. on the worksheet.

Teacher would teach the concept of Boyle’s Law. (15 minutes)

Elaborate 4. Students are asked to bring empty plastic bottles if available. Build a Cartesian diver by screwing

a fastener nut onto a plastic dropper, using which to withdraw an appropriate amount of water. Put the Cartesian diver in a soda bottle with ¾ water and squeeze the Cartesian diver up and down.

5. Students would explain the phenomenon using graphs, diagrams, words, or etc. on the worksheet. (20 minutes)

EvaluatePerformance Criteria Evidence RatingThe student is able to identify and draw the change in gas volume as well as its pressure.

The student completes question No.1, 2, and 3 on the activity sheet and provides reasoning.

The student is able to correctly identify the relationship between pressure and volume under constant temperature.

The student completes question No.1 and No.3 on the activity sheet in a reasonable fashion.

The student clearly grasps the concepts of Boyle’s law and is able to utilize its formula from to analyze specific information.

The student completes the task “Cartesian diver experiment” (question No. 5)

A= completes activity and achieves standard B= completes activity and nearly attains standardC= does not complete activity and begins to attain standard

Activity SheetHoles in the bottle:

1. Draw the diagram of the soda bottle, air inside, water and other important facts. What have you observed? Why does it happen?

Sticky Straw2. How can you transfer water using a straw without using your mouth?

3. Draw a diagram and try to explain why it would work:

Cartesian diverBuild a Cartesian diver by screwing a fastener nut onto a plastic dropper, using which to withdraw an appropriate amount of water. Put the Cartesian diver in a soda bottle with water and squeeze the Cartesian diver up and down.

4. Draw the water line both inside the soda bottle and inside the Cartesian diver before and after you squeeze the soda bottle in the diagram below:

5. Explain the change in pressure and volume for both the air inside the soda bottle and inside the Cartesian diver when the bottle is squeezed. Prove your point using appropriate formula.

Day 3: Absolute zero and temperature conversionPurpose of StudyStudents are going to learn about the concepts of Kevin, Fahrenheit, and Celsius temperature scales as well as their conversion following the 5-E learning model in a 50-minute class. Students will learn a lot of interesting facts when temperature is near absolute zero and complete a worksheet on temperature conversion.

SOLs CH.5 The student will investigate and understand that the phases of matter are explained by kinetic theory and forces of attraction between particles. Key concepts includea) pressure, temperature, and volume;

Materials and ResourcesSmart boardActivity sheet

Safety IssuesStudents would be advised not to practice dry ice or liquid nitrogen without supervision.

Procedures:Engage

Students would watch a video about super liquid when helium is around absolute zero temperature. (http://youtu.be/2Z6UJbwxBZI) (5 minutes)

Explore 1. Teacher would prompt students to think about how cold is the coldest temperature and let

students watch a video about absolute zero degree. (http://youtu.be/TNUDBdv3jWI) (10 minutes)

Explain 1. Teacher would teach the concept of absolute zero and temperature conversion using PowerPoint

slides. (15 minutes)

Elaborate 2. Students will complete the temperature conversion worksheet in class. (15 minutes)

EvaluateA= score 16 points or above on the worksheet (every question worth 1point; 19 points in total)B= score 12 points or above on the worksheet (every question worth 1point; 19 points in total)C= score 8 points or above on the worksheet (every question worth 1point; 19 points in total)D= score 7 points or below on the worksheet (every question worth 1point; 19 points in total)

Temperature Conversion Worksheet

Ko= Co + 273Fo = 9/5 Co +32 Co = 5/9(Fo-32)Convert the following to Fahrenheit

1) 10o C ________

2) 30o C ________

3) 40o C ________

4) 37o C ________

5) 0o C ________

Convert the following to Celsius

6) 32o F ________

7) 45o F ________

8) 70o F ________

9) 80o F ________

10) 90o F ________

11) 212o F ________

Convert the following to Kelvin

12) 0o C ________

13) -50o C ________

14) 90o C ________

15) -20o C ________

Convert the following to Celsius

16) 100o K ________

17) 200o K ________

18) 273o K ________

19) 350o K ________

Day 4: Charles’s LawPurpose of StudyStudents are going to learn about Charles’ Law following the 5-E learning model in a 50-minute class. Students will learn Volume and temperature are inversely proportional to each other when pressure and amount of gas is fixed.


Materials and ResourcesSyringeThermometerBeakerIceHot plateWaterSmart boardActivity sheet

Safety IssuesStudents need to wear safety goggles during experiment.Students need to handle hot plate with care and cannot touch its top surface during experiment.

Procedures:Engage

1. Teacher will demonstrate how to restore a crushed ping pong ball back to round shape after putting the ping pong ball in boiling water. (5 minutes)

Explore 2. Students will observe the relationship between temperature and volume: they will intake 15ml of

air through a syringe in room temperature. Students will put the syringe into an ice bath and withdraw water to the maximum mark reading on the syringe (35ml or 60ml depending on the size of the syringe.) (10 minutes)

Explain 3. Students would explain the phenomenon on the activity sheet. Teacher would teach the concept

of Charles’s Law using PowerPoint slides. (15 minutes)

Elaborate 4. Students will perform the Charles’ law syringe experiment. (See activity sheet for procedure.)

(20 minutes)

Evaluate

Performance Criteria Evidence RatingThe student is able to reason the relationship between temperature and volume.

The student completes question No.1 on the activity sheet and provides reasoning.

The student is able to record data in appropriate units and plot them accordingly.

The student completes the data recording and graphing on the activity sheet in a reasonable fashion.

The student is able to explain the recorded data and plotted graph using Charles’ law and its principle.

The student plausibly completes the two analysis question s on the activity sheet.


Charles’ Law Activity SheetPing pond ball recovery:

1. What happened to the crushed pingpong ball? Why did this happen?

Charles’ Law Syringe Experiment

Procedure:1. Intake 15mL of air using syringe at room temperature.2. Insert the syringe into the ice water bath and withdraw water to the maximum mark reading (35mL or 60 mL depending on your syringe size.)3. Insert a thermometer into the ice water bath. Wait for 2 minutes.4. Record the volume of water inside the syringe and temperature of water bath in the activity sheet.5. Record the temperature of water bath in the activity sheet for every mL change in volume of water inside the syringe. 6. Plot a graph of volume vs. temperature, and extrapolate (extend) the best fit line to a volume of zero.

Data:

Total Volume (Volume of water + Volume of Air) = ____________________________

Vwater (mL) Vair (mL) T (o C or oF) T (oK) Vwater / T (mL/ oK)

Analysis:1. A direct relationship is one where the dependent variable increases or decreases in the same

direction as the independent variable. For example as obesity increases in a population so does the incidence of diabetes. An inverse relationship will see the change in the opposite direction to the independent variable (“as the number of days left in the year decreases, student excitement increases”). What do we have here?

2. Somewhere you may have heard that the equation for a linear relationship can be described as y=mx+b. Does your data look like it? Could it be described this way? Explain.

Day 5: Gay-Lussac’s LawPurpose of Study

Students are going to learn about the Gay-Lussac’s Law following the 5-E learning model in a 50-minute class. Students will learn pressure and temperature are directly proportional to each other when volume and amount of gas is fixed.


Materials and ResourcesWorksheet

Safety IssuesNone

Procedures:Engage

1. Teacher will invoke students thinking about the relationship between pressure and temperature by real-life example: tire would be more likely to explode during summer time on highway. (5 minutes)

Explore2. Teacher will show students a video about how steam engine works and engage students’

discussion. (10 minutes)(http://youtu.be/73txXT21aZU)

Explain 3. Teacher would teach the concept of Gay-Lussac’s Law using PowerPoint slides, as well as going

over Boyle’s Law and Charles’ Law which have been taught previously. (15 minutes)

Elaborate 4. Students will work on the mixed gas law worksheet, which encompasses Boyle’s Law, Charles’

Law and Gay-Lussac’s Law. The worksheet will be due as homework the next day. (20 minutes)

EvaluateA= score 18 points or above on the worksheet (every question worth 3point; 21 points in total)B= score 14 points or above on the worksheet (every question worth 3point; 21 points in total)C= score 10 points or above on the worksheet (every question worth 3point; 21 points in total)D= score 9 points or below on the worksheet (every question worth 3point; 21 points in total)

Mixed Gas Law Worksheet 1.0 atm = 101.3 kPa = 760 mmHg And 0C = 273 K

Change the following units: 359 kPa = _________ atm 10C = ________ K

6.2 atm = ________ kPa 10K = _______ C

1. The gas in a sealed can is at a pressure of 3.00 atm at 25C. A warning on the can tells the user not to store the can in a place where the temperature will exceed 52C. What would the gas pressure in the can be at 52C?

2. A sample of hydrogen exerts a pressure of 0.329 atm at 47C. The gas is heated 77C at constant volume. What will its new pressure be?

3. A sample of neon gas occupies a volume of 752 mL at 25C. What volume will the gas occupy at standard temperature if the pressure remains constant?

4. A sample of oxygen gas has a volume of 150 mL when its pressure is 440 mmHg. If the pressure is increased to standard pressure and the temperature remains constant, what will the new gas volume be?

5. Ralph had a helium balloon with a volume of 4.88 liters at 150 kPa of pressure. If the volume is changed to 3.15 liters, what would be the new pressure in atm?

6. 5.36 liters of nitrogen gas are at -25C and 733 mm Hg. What would be the volume at 128C and 733 mm Hg?

7. At constant temperature, 2 L of a gas at 4 atm of pressure is expanded to 6 L. What is the new pressure? (Do this one conceptually and not algebraically.)

Day 6-7: Combined Gas Law

Purpose of StudyStudents are going to learn about the combined gas law in two 50-minute class. Students will learn the combined gas law concepts from Power point slides and work on practice problems in the first 50-minute class period; students will spend the next 50-minute class period complete a PhET simulation lab.


Materials and ResourcesComputersSmart boardActivity sheets

Safety IssuesNone

Procedures:First 50-minute class

1. Teacher will teach the combined gas law concepts using Power point slides.2. Students will work on practice problems.

Second 50-minute class3. Students will complete a PhET simulation lab and its worksheet as shown below.

PhET Gas Law Simulation Worksheet(The worksheet is cited from http://phet.colorado.edu/new/simulations/sims.php?

sim=Gas_Properties)

Part 1: Play

Procedure:1. Pump the handle once. Watch the temperature and pressure gauge. See how long it takes for the values to stabilize. Record the values in Table 1 on the next page.

2. Using the little person pushing on the wall, decrease the volume of the box in about half. Describe what happens to:Temperature:

Pressure:

3. Using the little person pushing on the wall, make the volume as small as possible and watch for at least 60 seconds. Thoroughly describe what happens over the course of the full minute. Be sure to address the following in your answer:

a. What happens to the container and the little man pushing on the container? b. What happens to temperature and pressure? c. Describe the particle speeds of both the heavy and light species.

4. Hit the “Reset” button. Give the pump a push with the heavy species. Wait for the values to stabilize and record the results in table 1 on the next page.

Are these values the exact same as the first time you did it? __________ Why or why not?

5. There is a box in the lower right corner entitled “Gas in Pump”. Select the “light species”. You will notice that the pump turns red. Give the pump a press. Wait for the values to stabilize and record the results in table 1 on the next page.

6. In the box entitled “Heat Control”, grab the arrow and move it to add. What happens?

7. Using the “Heat Control”, grab the arrow and move it to “remove.” What happens?

8. Feel free to play with the simulator. Try the “Pause” and “Step” buttons at the bottom. Try sliding the top of the container. Take about 3-5 minutes to play with the different options.

Table 1: Playing with the simulation programAfter pumping the “heavy” handle once (1st time)

After pumping the “heavy” handle once

After cutting the volume in about half

Reset: Constant volume 1 pump of heavy species

Added 1 pump of light species

Temperature (K)

Pressure (atm)

Number of Heavy SpeciesNumber of Light Species

Part Two: Boyle’s LawPurpose: To see how pressure and volume are related to each other (keeping everything else constant).

Procedure: 1. Hit the reset button. 2. In the upper left corner under “Constant Parameters”, select “Temperature”. This will make sure that temperature will not change significantly. 3. We will need a way to measure the volume. Hit the button “Measurement Tools”. Select the “Ruler” box. A ruler should appear at the top of the screen. The ruler can be moved so you can measure the size of the box. This will make a good way of measuring the volume.

4. To see how the relationship between pressure and volume works, temperature and number of moles must be constant. The temperature can be held constant by selecting it in the corner.

5. Take 8 separate measurements over a large range of numbers without exploding the container.

Table 2: Volume and Pressure of a gas with temperature constant at_______ and Particles constant at _________

Volume (nm)

Pressure (atm)

Volume xPressure (nm x atm)

Questions: 1. What is the independent variable?

2. What is the dependent variable?

3. What 2 factors are being held constant?

4. What does the mathematical relationship indicate?

Part 3. Charles’ Law

Purpose: to determine the relationship between volume and temperature (with everything else constant).

Procedure: You get to design how to test the purpose. Write down the settings you put the simulator to.

Please note: if you want to hold pressure constant, the container must have something in it first. Add particles, then hold pressure constant. If you hold pressure constant before adding particles in the container (P = 0 atm), the program will attempt the impossible, by trying to hold the pressure at 0 atm.

1. What is the independent variable?

2. What is the dependent variable?

3. What 2 factors are being held constant?

Make a data table to collect at least 8 pieces of data over a large range. Be sure the data table has the proper components (title, units, gridlines, etc).

Table 3: ___________________________________________________________________

Make a graph of the Charles’ Law relationship. Be sure your graph has all of the proper components.

7. Describe the relationship of Charles’ Law. Be sure to include the variables and constants in your answer.

Day 8-9: Ideal Gas Law

Purpose of StudyStudents are going to learn about the ideal gas law following the 5-E learning model in two 50-minute classes. Students will elaborate their learning on experiments such as boil water at room temperature.


Materials and ResourcesSmart boardBell jar and vacuum pump set Activity sheets

Safety IssuesStudents do not need boiling water in this experiment. The water at room temperature will boil in bell jar.

Procedures:Engage

1. Students will watch a TED video about property of gas (5 minutes)(http://youtu.be/BY9VGS2eXas)

Explore 2. Demonstrate that one mole gas of all kinds occupies 22.4 liter of volume under standard

temperature and pressure through dividing molecular mass by density, which is based on Avogadro’s hypothesis. (10 minutes)

Explain 3. Teacher will teach the concept of ideal gas law using Power point slides. (35 minutes)

Elaborate 4. Students will perform the bell jar and vacuum pump set experiment. They will measure the mass

of air, inflate a piece of marshmallow and boil a cup of water at room temperature. (50 minutes)

EvaluatePerformance Criteria Evidence RatingThe student is able to understand that pulling air out would decrease the amount of air inside the jar and decrease it mass.

The student completes question No.1-16 in Part A on the activity sheet and provides reasoning.

The student clearly grasps the relationship between amount of gas and pressure.

The student completes question No.2-4 in Part B and No.2-7 in Part C on the activity sheet in a reasonable fashion.

The student is able to analyze all variable in ideal gas law and apply its principle.

The student completes question No. 8 in Part C on the activity sheet in a reasonable fashion.


Bell Jar Vacuum Pump Activity Sheet(This activity sheet is cited from www.juniata.edu/services/.../MS.../Bell%20Jar

%20Vacuum%20Pump.doc)

Setup: The diagram below shows how the bell jar vacuum should be setup.

Figure 1 – Bell jar vacuum pump setup.

1. The O ring, part (C), should already be installed on the bottom plate, part (B).

2. The bell jar, part (A), fits over the smaller diameter portion of the bottom plate with the rim in contact with the O ring.

3. One fitting of part (D) will connect with the top of the bell jar, part (A). Only a slight turn, approximately one-third of a gentle turn, is all that is needed to make a secure connection. DO NOT OVER TIGHTEN!!

4. One of the small arms of the T in part (E) connects to the syringe, part (F). DO NOT OVER TIGHTEN, only a slight turn is necessary. The other small arm of part (E) connects to the unconnected fitting of part (D). Only a partial turn is needed, DO NOT OVER TIGHTEN! The remaining connector of part (E) will be left unconnected. Note: part (D) and (E) may already be connected to one another.

ProcedurePart A: The Phantom MassIn this section you will attempt to find the mass of a known gas mixture, air.

1. Study the apparatus. The check valve will easily allow air to flow in the direction shown by the arrows, but not in the other direction. What is inside the bell jar now? (Hint: “Nothing” is not correct.)___________________________________________________

2. Have a partner push down on the bell jar to make certain that the bell jar is pressing against the O ring. While your partner is doing this, pull the piston of the syringe out to the 60 cc mark. DO NOT pull the piston the whole way out.

3. Where does the air come from that fills the syringe? _____________________________

4. Let go of the piston, and watch what happens. Now quickly push the piston all the way back into the syringe. Listen for the sound of moving air.

5. Where did the air go that was in the syringe? ___________________________________

6. Describe the amount of force that was required to pull out the piston. _______________________________________________________________________

7. What kind or kinds of forces resisted you as you pulled out the piston?_______________________________________________________________________

8. Repeat these steps five times:1. Pull the piston out to the 60 cc mark2. Let go of the piston and see what happens3. Push the piston all the way back in

9. As you followed the steps in #8, what happened to the amount of force required? _______________________________________________________________________

10. Explain why the amount of force changed in this manner. _______________________________________________________________________

11. Pull the piston of the syringe out to the 60 cc mark and push it all the way back in. Repeat this 24 times. You should notice that there is no air movement by the end of this process. What is in the bell jar now? _______________________________________________

12. Place the bell jar apparatus on a balance. Disconnect part (D) from (E). You should weigh the bell jar (A), bottom plate (B), O ring (C), and hose (D). Record the mass in the given data table (page 4).

13. Loosen the connection between hose (D) and the bell jar, remove the hose, and then reconnect it. Did you hear the movement of air? What was the air doing?_______________________________________________________________________

14. Again place the bell jar, with hose (D), bottom plate, and O ring on the balance. Make certain that hose (D) is not touching anything. Record the mass in the data table.

Data Table/ Calculations:

Step MASS(0.00g)

12

14

Difference in mass between steps 12 and 14

Questions:15. What does the difference in mass represent?

16. Do you think the bell jar was really empty when you weighed it in step 12?

Part B: Marshmallow under Pressure

1. Place the marshmallow inside the bell jar. Reassemble bell jar as previously did. Begin to pump the piston. What happens to the marshmallow?

________________________________________________________________________

2. Why did the marshmallow change in the way that it did?

________________________________________________________________________

3. Loosen the connection between hose D and the bell jar until you hear the movement of air. What happens to be marshmallow?

________________________________________________________________________

4. Why did this change occur?

________________________________________________________________________

Part C: Liquid in a Vacuum1. Imagine some water from the hot water tap that has just been poured into a cup. Why is

the water not boiling now?________________________________________________________________________

2. Think about the boiling process. The water becomes a gas (steam) bubbles that take up much more room that made them. Do you thing that the presence of atmospheric helps the boiling process, or makes it more difficult?________________________________________________________________________

________________________________________________________________________

3. Can you predict what would happen if we put a container of hot tap water into the bell jar and pump out the air?

________________________________________________________________________4. Fill a small beaker with hot tap water. Take its temperature using a thermometer and

record its value below:

________________________________________________________________________5. Place the beaker inside the bell jar. Reassemble bell jar as previously did. Begin to pump

the piston. What happens?

________________________________________________________________________6. What do you think has happened to the temperature of the water?

________________________________________________________________________7. Keep pumping until there is no further effect. Then slowly loosen the connection between

hose (D) and the bell jar. Now open the bell jar and record the temperature of the water. What has happened?

________________________________________________________________________

8. Explain this experiment using ideal gas law:

PV=nRTHow does P, V, n, R, T react in this experiment? What variable has changed and how has it change? What variables have stayed about the same?________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

Day 10-11: Dalton’s Law of Partial PressurePurpose of Study

Students are going to learn about Dalton’s law of partial pressure following in two 50-minute class through lecture and experiment. Students will learn that each kind of gas has partial pressure, which would add up to the total pressure.


Materials and ResourcesThermometerButane lighters with wheels taken offGraduated cylindersWaterSmart boardContainersActivity sheet

Safety IssuesSafety goggles need to be worn at all times during experiment.

Procedures:First 50-minute class

5. Teacher will teach the Dalton’s law of partial pressure using Power point slides.6. Students will work on practice problems.

Second 50-minute class7. Students will perform Dalton’s law of partial pressure lab and complete its activity sheet as

shown below.

Dalton’s Law of Partial Pressure LabPRE-LAB DISCUSSION: A mole of any pure gas at STP has a volume of 22.4 liters. The weight of that gas in grams is equal to the molecular mass of the gas in atomic mass units. If the volume, mass, temperature and pressure of a gas is known, then using the combined gas law, its volume can be mathematically converted to a volume at STP. Then, the mass of 22.4 liters can be determined. Thus its molecular mass can been determined experimentally.

When gas is collected by water displacement, Dalton's law of partial pressures can be used to factor out the water vapor.

OBJECTIVE: To experimentally determine the molecular mass of butane.

CHEMICALS/EQUIPMENT: butane lighter, balance, 100 ml graduated cylinder, tub [bucket, dishpan etc, thermometer glass plate.

PROCEDURE:1.Determine and record the exact mass of the butane lighter [estimate to the 100th of a gram].2.Fill the tub or other large container with water.3.Fill the 100 ml graduated cylinder completely with water and using your hand, invert it into the tub without permitting any air bubbles in it.4.Make sure that the lighter is turned to its highest gas flow. Hold the butane lighter under the mouth of the 100 ml graduated cylinder, press the release lever, being careful that all of the gas flows into the 100 ml graduated cylinder. Hold the 100 ml graduated cylinder so that the100 ml mark is exactly even with the water level in the tub. Fill the 100 ml graduated cylinder to the 100 ml mark that you made on the 100 ml graduated cylinder.5.Determine and record the temperature of the water in the tub and the barometric pressure of the lab.6.Thoroughly dry the butane lighter and determine and record its exact mass.

DATA

Initial mass of lighter.............................................................. ____________________ gFinal mass of lighter.............................................................. ____________________ gMass of butane collected......................................................... ____________________ gvolume of butane collected.................................................... ____________________ mlTemperature .........................................................................____________________ °Clab pressure .......................................................................... ___________________ mmHgwater vapor pressure at this temperature............................... ____________________ torrpartial pressure of butane........................................................____________________ torr

CALCULATIONS:

1. Using Dalton's law of partial pressures, enter the pressure of water vapor that corresponds to the lab temperature in the data table. Then subtract this from the lab pressure to find the partial pressure of butane gas.

2. Convert the lab temperature from Celsius to Kelvin.

3. Using the combined gas law formula, calculate the volume of butane at STP. Record your answer.

4. Determine what mass of this gas would produce 22,400 ml at STP. Record your answer.

5. Butane has the formula C4H10. Calculate its molecular mass from this formula. Record your answer.

6. Calculate your percentage of error.

THINKING SCIENTIFICALLY

1. What could you have done to have more accurate results?

2. Write a balanced equation for the reaction of butane with oxygen.

3. How much butane is contained in a new lighter? [read the label]

4. If all the butane in the lighter is reacted with air:

A. What volume of air would be needed for this reaction? [Hint-air is only 1/5 oxygen]

B. What would be the total volume of the gases produced by this reaction? [Hint-H2O and CO2 are the gases produced]

Day 12: Gas Law Test

Purpose of StudyStudents are going to be assessed regarding their understanding on all gas laws they have studied.

SOLs CH.5 The student will investigate and understand that the phases of matter are explained by kinetic theory and forces of attraction between particles. Key concepts include

a) pressure, temperature, and volume;b) partial pressure and gas laws;

Materials and ResourcesTest paper

Safety IssuesNone

Procedures:Students will complete the gas property test in a 50-minute class.

Gas Property Test1. For a gas, which two variables are inversely proportional to each other (if all other conditions

remain constant)? A. P, T B. P, V C. V, T D. n, V E. n, P

2. All of the following statements concerning a sample of oxygen gas at 1.00 atm pressure are true exceptA. The molecules are in constant rapid random motion. B. The pressure exerted by gaseous oxygen is due to the impact of the molecules with the walls of

the container. C. The average kinetic energy of the gaseous oxygen is proportional to the absolute temperature of

the gas. D. The oxygen gas pressure is greater than the pressure created by the same amount of hydrogen gas. E. The volume occupied by the oxygen molecules is negligible compared with the size of the

container.

3. A given mass of gas in a rigid container is heated from 400 K to 1200 K. Which of the following responses best describes what will happen to the pressure of the gas? A. The pressure will remain the same. B. The pressure will decrease by a factor of three. C. The pressure will increase by a factor of three. D. The pressure will increase by a factor less than three. E. The pressure will increase by a factor greater than three.

4. a. What is the volume of 1 mole of any gas at STP? __________________

b. What is STP? Provide an answer using at least two different units of pressure and complete sentences._______________________________________________________________________

5. If the temperature of a 2.40 L sample of gas is changed from 30.0 °C to 20.0 °C while the pressure is held constant, what is the final volume of the sample?

6. At a temperature of -33.3°C, a sample of gas exerts a pressure of 53.3 kPa. If the volume remains constant, at what temperature will the pressure reach 133 kPa?

7. If the volume of a sample of gas at 120 °F is changed from 3.40 L to 2.10 L and the pressure changes from 754 mm Hg to 544 mm Hg, what is the new temperature of the gas?

8. What volume is occupied by 5.03 g of O2 at 28°C and a pressure of 0.998atm?

9. At what temperature in °F would 2.10 moles of N2 gas have a pressure of 1.25 atm and in a 25.0 L tank?

10. Calculate the pressure in a 212 Liter tank containing 3.4 moles of argon gas at 25°C?

11. A container holds three different gases (N2, O2, and CO2) at a total pressure of 857 mm Hg. The partial pressure of nitrogen is 561 mm Hg. The partial pressure of oxygen is 249 mm Hg. What is the partial pressure of the carbon dioxide?

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