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L7.6

*Lesson 7.6:  What is happening to the atmosphere as heat is added?

  1. Let’s review lesson L 7.4 with a calorimetry problem. Remember q = mC∆T. How much energy, in Joules, would it take to heat 250 mL of water (specific heat water 4.184 J/g°C) from 20°C to 37°C? How much energy in calories (specific heat water 1.00 cal/g°C)

\(q_{J} = 250g * 4.184 * 17 = 17782 J\)

\(q_c = 4250 C\)

  1. Recalling our previous lesson, ‘Global Warming or None Like it Hot!’ 
    1. What does this representation do well? 
    2. Would ice help with global warming?
    3. What did we learn last class about sea level rise? Review the IMT for Lesson 5.

Investigating Gases

Gasses are important to the atmosphere and oceans.  The behavior of gasses follows predictive patterns called ‘gas laws’. Understanding the gas laws is fundamental to understanding the gas exchange between the ocean and the atmosphere. In this activity, you are going to do a series of four investigations to see the relationship between four variables that affect gasses: pressure, temperature, volume, and the number of particles.

Let’s define these variables as they relate to gasses:

Pressure, P: The rapid motion and collisions of molecules with the walls of the container cause pressure (force on a unit area). The pressure is proportional to the number of molecular collisions and the force of the collisions in a particular area. The more collisions of gas molecules with the walls, the higher the pressure.  

Temperature, T: The temperature of a gas is a measure of the average translational kinetic energy of the molecules. In a hot gas, the molecules move faster than in a cold gas; the mass remains the same, but the kinetic energy, and hence the temperature, is greater because of the increased velocity of the molecules.  

Volume, V: Gasses do not have a fixed volume where the volume depends on the container holding the gas.  For our purposes, volume refers to the space the collective gas particles occupy and not the space occupied by a single gas particle.  Since gas particles are so small, their volumes are negligible.  But the space occupied by the gas particles as a collective is considered the volume, which equates to the volume of the container holding the gas.  

Number of particles, n: The number of particles present impacts the behavior of gasses. The number of particles is the number of moles of a substance.  Remember that 1 mole = 6.02 x 1023 count.  

Materials

  • Safety Goggles

  • Scale

  • 250 mL Beaker

  • Syringe

  • Black syringe cap

  • Petri dish

  • 4-Balloons

  • Tea Light

  • Matches

  • Small balloon

  • Paper Towel

  • Tape

Investigation 1: Boyle's Law

  1. Grab your syringe and remove the plunger so the plunger and plastic barrel of the syringe are separated.

  2. Take 1 small marshmallow and place it into the barrel of the syringe.  

  3. Insert the plunger and push the plunger down to the point where the plunger is slightly touching the marshmallow. 

  4. Twist the black cap onto the hub and secure it tightly.

  5. Once the cap is secure, pull up on the plunger while holding the barrel in place.  Make the observations in the table below.

  6. Unscrew and remove the cap. This allows atmospheric gasses to come into equilibrium with the gas inside the syringe.  

  7. Move the plunger up to a point so there is a couple of centimeters above the marshmallow.

  8. Twist cap onto the hub and secure tightly again.

  9. Once the cap is secure, push down on the plunger while holding the barrel in place. Make observations in the table below.

  10. Complete the questions in the data table below.

Data Table - Investigation 1: Boyle's Law

Plunger Position Observations of what happened to the marshmallow. What variables changed? (Pressure, Volume, Temperature) Which variable stays constant? (Pressure, Volume, Temperature) What is the Relationship between the changing variables?  (Direct or Inverse)
Plunger was pulled up Expanded Volume, pressure temperature, n pressure inverse to volume
Plunger was pushed down crumpled volume, pressure temperature, n Pressure inverse to volume

PV = k

Investigation 2: Charles’ Law

  1. Blow up a balloon to about the diameter of a grapefruit.

  2. Use the string to measure the balloon's circumference.

  3. Use a tong to submerge the inflated balloon in ice water.

  4. After about 2 minutes, remove the balloon.

  5. Use the string to measure the circumference again and compare.

  6. Remove them from the containers and leave them on the desk for the next group.

Data Table - Investigation 2: Charles Law

Balloon during heating  & during cooling Observations of what happened to the balloon. What variables changed? (Pressure, Volume, Temperature) Which variable stays constant? (Pressure, Volume, Temperature) What is the Relationship between the changing variables?  (Direct or Inverse)
At room temperature regular balloon none volume, n, temp, pressure none
During Cooling balloon shrank volume, temp pressure, n temp direct to volume

V/T = k

Investigation 3: Gay-Lussac’s Law

  1. Place the tea light in the middle of the petri dish.

  2. Fill the petri dish with water so that the water level is ½ way up the side of the tea light.  The photo has blue food coloring added for easier viewing.

  3. Light the tea light and wait a moment until the tea light is burning properly.

  4. Cover the burning candle by placing the 250 mL beaker upside down on the petri dish. The 250 mL beaker should be submerged in water. 

  5. After the flame is extinguished, make and record observations in the data table below.

  6. Carefully remove the 250 mL beaker from the petri dish.

  7. Record observations and answer questions in the data table below.

Data Table - Investigation 3: Gay-Lussac’s Law

Water Level Observations of what happened to the water level. What variables changed? (Pressure, Volume, Temperature) Which variable stays constant? (Pressure, Volume, Temperature) What is the Relationship between the changing variables?  (Direct or Inverse)
After the flame is extinguished water got sucked into the beaker pressure, temperature, volume number of particles pressure inverse to volume, temp direct to pressure and volume.
After beaker is removed water fell out of beaker pressure, temperature, volume number of particles

P/T = k

PV/T = k

Investigation 4: Avogadro’s Law

  1. Obtain your empty balloon and scale. 

  2. Make observations of the empty balloon in the data table below.

  3. Mass the empty balloon and record in the data table below.

  4. Fill the balloon so that it is roughly the size of a softball, a soccer ball is too big. (about 3-4 breaths)

  5. Tie off the balloon so that air does not escape.

  6. Make observations of the filled balloon in the data table below.

  7. Mass the filled balloon and record in the data table below.

Data Table - Investigation 4: Avogadro’s Law

Blowing up balloon Observations of balloon Mass (g) of balloon What variables changed? (Mass, Pressure, Volume, Temperature) What variables stayed constant? (Mass, Pressure, Volume, Temperature) Relationship between the changing variables?  (Direct or Inverse)
Before filled with air deflated 3.00 g none none
After filled with air inflated 3.03 g mass, n temp pressure direct to n, pressure direct to mass, volume direct to n, volume direct to mass, volume inverse to pressure

Analysis Questions:

  1. Explain the relationship between pressure and volume using evidence from your investigation.

    pressure and volume are inversely related

  2. Explain the relationship between temperature and volume using evidence from your investigation.

    temp and volume are directly related

  3. Explain the relationship between pressure and temperature using evidence from your investigation.

  4. Which graph best represents the relationships of the gas variables?  *You can delete the option that is not applicable in a, b, and c below.

Graph A

Graph B

  1. Pressure and Volume: Graph A or Graph B

    B

  2. Temperature and Volume:  Graph A or Graph B

    A

  3. Pressure and Temperature:  Graph A or Graph B

    A

  4. Imagine you are blowing up a balloon to make it as big as possible without popping.

  5. Why does the mass increase when you blow up a balloon?

  6. Why does the volume increase when you blow up a balloon?

  7. Avogadro’s Law is the relationship between moles and volume. Explain the relationship between the number of particles (moles) and volume using evidence from blowing up a balloon. 

  8. Which graph above best represents this relationship?

  9. The molar mass of air is approximately 28.97 g/mole.  

  10. How many moles were in your sample in the balloon in Investigation #4? 

  11. How many gas particles were in your sample? 1 mole = 6.02 x 1023

  12. Watch the egg in bottle (1:04) demonstration or the teacher demonstration.  

  13. What variables changed? 

  14. What variables are constant?  

  15. For the variables that are changing, is this a direct or indirect relationship? 

  16. What law does this demonstration best follow?

  17. Watch the implosion of a tanker (1:38).  

  18. What variables changed? 

  19. What variables are constant?  

  20. For the variables that are changing, is this a direct or indirect relationship?  

  21. What law does this demonstration best follow?

  22. Watch the NASA | A Year in the Life of Earth's CO2 video (3:10).

  23. Can you explain how CO2 moves throughout the atmosphere?

  24. Can you explain why there is a fluctuation in carbon dioxide levels throughout the year?

  25. Why do you think the amount of carbon dioxide in the atmosphere is higher around landmasses than over the open ocean?

  26. If additional carbon dioxide is being expelled into the atmosphere, then what is happening to the pressure above the ocean? 

  27. Can you relate this pressure phenomenon from the previous question to one of the gas laws explored in this investigation?

  28. Consider the graph below of the average global sea surface temperature from 1880 - 2015.

  29. What is happening to the Global sea surface temperature?  

  30. Describe the relationship of surface temperature to the additional carbon dioxide being expelled into the atmosphere and its pressure.

  31. How can these relationships describe our changing weather patterns in the atmosphere?

NEXT STEPS:

  1. Reflect on today’s question: What is happening to the atmosphere as heat is added?

  2. Reflect on the unit question, how does today’s activity relate to the unit question? Open up the IMT for this unit, complete all boxes for lesson 6.

  3. Make sure all parts of the L7.6 student sheet are complete & complete the check for understanding on Schoology.

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Last update: June 5, 2023
Created: June 5, 2023