Skip to Main Content

Share Suggestion

The ABCs of Gases (Air, Balloons, and Cool Laws)

Unit

The ABCs of Gases (Air, Balloons, and Cool Laws)

Objectives

In this unit, students will learn that gases are found all throughout the natural world and laws govern their characteristics. Students will:

  • develop an understanding of the gas laws.

  • identify common gases.

  • understand that certain laws govern the physical properties of ideal gases.

  • utilize mathematical relationships to predict changes in the temperature, pressure, and volume in a gaseous system (i.e., Boyle’s law, Charles’s law, and the combined gas law).

Essential Questions

  • How do gases behave?

  • How do changes in pressure, volume, and temperature affect a gas?

Related Unit and Lesson Plans

Related Materials & Resources

The possible inclusion of commercial websites below is not an implied endorsement of their products, which are not free, and are not required for this lesson plan.

Formative Assessment

  • View

    Multiple Choice Items:

    1. A balloon filled with helium has a volume of 4.5 L at 300 K. A teacher pours liquid nitrogen over the balloon reducing the temperature to 80 K. What should the final volume of the balloon be if the pressure remains constant?

      A

      1.2 L

      B

      2.8 L

      C

      8.3 L

      D

      17.0 L

    2. The diagram below shows the initial and final position of a piston inside a cylinder containing carbon dioxide gas.


    02a.PNG

    If the pressure is held constant, what will be the final temperature of the carbon dioxide gas?

    A

    −163°C

    B

    53°C

    C

    110°C

    D

    508°C

    1. The diagram below shows nitrogen gas being held in a glass bulb on the left.

    03a.PNG

    The pressure of the nitrogen in the left bulb is 2.00 kPa. If the valve between the two bulbs is opened and the temperature held constant, what will be the final pressure in both bulbs?

    A

    0.679 kPa

    B

    1.03 kPa

    C

    1.32 kPa

    D

    3.89 kPa

    1. Which graph best shows the relationship between the pressure and volume of a sample of hydrogen gas at constant temperature?

    04a.PNG

    1. Herbert Nitsch set a world record in 2007, diving to a depth of 214 m in seawater. The total pressure at that depth was 22 atm. If his lung volume was 7.0 L at the surface where the pressure was 1.0 atm, then what was his lung volume at the 214 m depth assuming the temperature was constant?

    A

    0.033 L

    B

    0.32 L

    C

    0.72 L

    D

    31 L

    1. An expandable hot air balloon has a volume of 800 m3 at 295 K. The air inside the balloon is heated by a burner and sunlight falling on the dark balloon material. The air pressure increases from 1.03 atm to 1.04 atm and the volume of the balloon increases to 830 m3. What is the final temperature of the air inside the balloon? Use the combined gas law to calculate your answer.

      A

      298 K

      B

      309 K

      C

      311 K

      D

      314 K

    2. A helium balloon filled with helium at a 1,000-m elevation has an internal pressure of 0.938 atm and a volume of 4.80 L. The temperature is 17°C. The balloon is then brought to a home at sea level. The temperature is 24°C and the internal pressure increases to 1.05 atm. What will be the new volume of the balloon? Use the combined gas law to calculate your answer.

      A

      2.85 L

      B

      4.19 L

      C

      4.39 L

      D

      6.05 L

    3. Which of the following is an accurate description of the relationship between the pressure and volume of a gas?

      A

      volume increases as pressure decreases

      B

      volume increases as pressure increases

      C

      volume remains constant as pressure increases

      D

      volume remains constant as pressure decreases

    4. What is 23°C in Kelvin?

    A

    296 K

    B

    306 K

    C

    286 K

    D

    299 K

    Multiple choice Key:

    1. A

    2. D

    3. A

    4. B

    5. B

    6. B

    7. C

    8. B

    9. A

    Short Answer Items:

    10. A student has a 1000-ml sample of nitrogen which can be assumed to act as an ideal gas. The pressure is held constant while the temperature is increased from 250 K to 400 K.

    Part A: Graph the volume of the nitrogen gas versus the absolute temperature using the grid below.

    10a.PNG

    Part B: Assuming the temperature can continue to be increased, find the volume of the nitrogen at 650 K. Show all work.


    11. A student has a 60.0-ml sample of argon, a real gas which acts very much like an ideal gas. The temperature is held constant at 20°C while the pressure is increased from 0.50 atm to 2.00 atm.

    Part A: Using Boyle’s law, graph points on the grid corresponding to pressures of 0.50, 1.00, 1.50, and 2.00 atm and draw a curve to fit the points.

    11a.PNG

    Part B: If the pressure was increased to 5.0 atm, what would be the final volume of the argon? Assume the temperature remains constant.

    Short-answer key and Scoring Rubrics:

    10. A student has a 1000-ml sample of nitrogen which can be assumed to act as an ideal gas. The pressure is held constant while the temperature is increased from 250 K to 400 K.

    Part A: Graph the volume of the nitrogen gas versus the absolute temperature using the grid below.

    The response shows a graph similar to the following.

    10akey.PNG

    Part B: Assuming the temperature can continue to be increased, find the volume of the nitrogen at 650 K. Show all work.

    A similar setup to the one shown below with the correct answer.

    10bkey.PNG
    The volume at 650K would be 2,600 mL.



    Scoring Rubric for Question 10:

    Points

    Description

    2

    • The student’s response shows a correct graph of the volume versus temperature of the nitrogen gas.

    • The response correctly shows how the volume of the nitrogen gas at 650 K was calculated resulting in a correct answer.

    1

    • The student’s response shows an incorrect graph of the volume versus temperature of the nitrogen gas, but correctly shows how the volume of the nitrogen gas at 650 K was calculated resulting in a correct answer.

    –OR–

    • The student’s response shows a correct graph of the volume versus temperature of the nitrogen gas, but incorrectly shows how the volume of the nitrogen gas at 650 K was calculated resulting in an incorrect answer.

    –OR–

    • The student’s response shows a partially correct graph of the volume versus temperature of the nitrogen gas and correctly shows how the volume of the nitrogen gas at 650 K was calculated, but obtains an incorrect answer.

    0

    • The student’s response shows an incorrect graph of the volume versus temperature of the nitrogen gas.

    • The response incorrectly shows how the volume of the nitrogen gas at 650 K was calculated resulting in an incorrect answer.

    11. A student has a 60.0-ml sample of argon, a real gas which acts very much like an ideal gas. The temperature is held constant at 20°C while the pressure is increased from 0.50 atm to 2.00 atm.

    Part A: Using Boyle’s law, graph points on the grid corresponding to pressures of 0.50, 1.00, 1.50, and 2.00 atm and draw a curve to fit the points.

    The response shows the following four points and curve similar to the following.

    11akey.PNG

    Part B: If the pressure was increased to 5.0 atm, what would be the final volume of the argon? Assume the temperature remains constant.

    A similar setup to the one shown below with the correct answer.

    11bkey.PNG

    The volume at 5.0 atm would be 6.0 mL.

    Scoring Rubric for Question 11:

    Points

    Description

    2

    • The student’s response shows all four points correctly graphed on the grid with a curve connecting each point for the volume versus pressure of the argon gas.

    • The response correctly shows how the volume of the nitrogen gas at 5.0 atm was calculated resulting in a correct answer.

    1

    • The student’s response does not show all four points correctly graphed on the grid with a curve connecting each point for the volume versus pressure of the argon gas, but correctly shows how the volume of the nitrogen gas at 5.0 atm was calculated resulting in a correct answer.

    –OR–

    • The student’s response shows all four points correctly graphed on the grid with a curve connecting each point for the volume versus pressure of the argon gas, but incorrectly shows how the volume of the argon gas at 5.0 atm was calculated resulting in an incorrect answer.

    –OR–

    • The student’s response shows all four points correctly graphed on the grid but fits a straight line to the graph instead of a curve for the volume versus pressure of the argon gas. The response correctly shows how the volume of the argon gas at 5.0 atm was calculated but gives an incorrect answer.

    0

    • The student’s response shows an incorrect graph of the four points for the volume versus pressure of the argon gas.

    • The response incorrectly shows how the volume of the argon gas at 5.00 atm was calculated resulting in an incorrect answer.

    Performance Assessment:

    The following diagram shows carbon dioxide (CO2) gas being held in a heat-resistant glass container on the left at a temperature of 20°C.

    pa01.PNG

    Part I

    The initial pressure of the CO2 is 0.500 atm. The apparatus is tilted 90° and the glass container on the left is dipped in ice water cooling the CO2 to 0°C. The volume decreases slightly from 1.000 L to 0.999 L.

    1. Set up an equation that uses the combined gas law to find the final pressure of the CO2 gas.

    2. Use the equation to calculate the final pressure of the CO2.

    Part II

    The upper left stopcock (valve) and the lower stopcock (valve) are opened and additional CO2 gas is pumped into both glass containers until the pressure reaches 1.20 atm. The initial temperature is 20°C. A Bunsen burner then heats the CO2 in both containers. The final pressure is 1.53 atm and the volume increases slightly from 2.000 L to 2.003 L.

    1. Set up an equation that uses the combined gas law to find the final temperature of the CO2 gas.

    2. Calculate the final temperature of the CO2.

    Performance Assessment Key:

    Part I

    The initial pressure of the CO2 is 0.500 atm. The apparatus is tilted 90° and the glass container on the left is dipped in ice water cooling the CO2 to 0°C. The volume decreases slightly from 1.000 L to 0.999 L.

    1. Set up an equation using the combined gas law to find the resulting pressure of the CO2 gas.

    2. Calculate the final pressure of the CO2.

    A setup similar to the following and the correct answer:

    pa01keyequations.PNG
    The pressure at 0°C will be 0.466 atmospheres.

    Part II

    The upper left stopcock and the lower stopcock are opened and additional CO2 gas is pumped into both glass containers until the pressure reaches 1.20 atm. The initial temperature is 20°C. A Bunsen burner then heats the CO2 in both containers. The final pressure is 1.53 atm and the volume increases slightly from 2.000 L to 2.003 L.

    1. Set up an equation using the combined gas law to find the resulting temperature of the CO2 gas.

    2. Calculate the final temperature of the CO2.

    A setup similar to the following and the correct answer:

    pa02key.PNG
    The temperature will be 374 K or 101°C.

    Performance Assessment Scoring Rubric:

    Points

    Description

    4
    • The student’s response shows correct setups of the equations for both parts of the question, the correct final pressure for the first part of the question, and the correct final temperature for the second part of the question.

    3

    • The student’s response shows a correct setup of one of the equations for one part of the question, the correct final pressure for the first part of the question, and the correct final temperature for the second part of the question.

    –OR–

    • The student’s response shows correct setups of the equations for both parts of the question. The response, however, shows only the correct final pressure for the first part of the question or the correct final temperature for the second part of the question.

    2

    • The student’s response shows correct setups of the equations for both parts of the question. However, the response does not show the correct final pressure for the first part of the question or the correct final temperature for the second part of the question.

    –OR–

    • The student’s response shows incorrect setups of the equations for both parts of the question. However, the response shows the correct final pressure for the first part of the question and shows the correct final temperature for the second part of the question.

    –OR–

    • The student’s response shows a correct setup of one of the equations for one part of the question and shows only the correct final pressure for the first part of the question or the correct final temperature for the second part of the question.

    1

    • The student’s response only shows a correct setup of one of the equations for one part of the question.

    –OR–

    • The response only shows the correct final pressure for the first part of the question or the correct final pressure for the second part of the question.

    0
    • The student’s response shows incorrect setups or omits setups of the equations for both parts of the question, shows the incorrect final pressure for the first part of the question, and shows the incorrect final temperature for the second part of the question.

DRAFT 11/19/2010
Loading
Please wait...

Insert Template

Information