1. Drill
Define Gay-Lussac’s Law.

2. Objective:
SWBAT: Measure the amount of carbon dioxide gas given off when antacid tablets dissolve in water in order to observe the ideal gas law.

3. SAT/HSA Enrichment Divers And Boyle's Law
This law has particular relevance to divers, as it has bearing on both mechanical effects and physiological effects of pressure.
Mechanical effects of pressure and volume include variations in buoyancy (e.g. a diver’s use of a buoyancy compensator to descend or ascend).

4. SAT/HSA Enrichment
Physiological effects of volume and pressure include potential impact on air-filled spaces in the human body (e.g. areas of potential baratrauma injuries).
In addition, Boyle’s Law interplays with other gas laws such as Dalton's Law—which, though not covered here—combine to dictate additional stresses on the a diver’s respiratory, circulatory, and nervous system.

5. SAT/HSA Enrichment In line 10, what does the term buoyancy refer to?
The upward force that a fluid exerts on an object less dense than itself.
Ability to recover quickly from setbacks.
Lightness of spirit.
The tendency to float in a liquid.
The property of something weightless and insubstantial.

6. Quiz
Compare and Contrast Boyle’s, Charles’s, and Gay-Lussac’s Law.

7. Demonstration
Peel a hard-boiled egg and put the larger end of the egg pointing into the flask.
Ask a student volunteer to try to gently push the egg into the flask without breaking it.
Remove the egg and grab 2-3 cotton balls with tongs. Light the cotton balls on fire and place them in the Erlenmeyer flask.
Immediately put the small end of the egg on the top of the flask.

8. Demonstration
Ask the students how to get the egg out of the flask. Have students support their statements.
Turn the flask upside down and position the egg so them small end of the egg is pointing to the outside of the flask.
Blow into the flask very hard and pull the flask back—the egg should come flying out. Be careful not to get the egg in your mouth.

9. Ideal, Dalton, and Graham
Other Gas Laws
Ideal, Dalton, and Graham

10. Ideal Gases
Solid carbon dioxide, or dry ice, doesn’t melt. It sublimes. Dry ice can exist because gases don’t obey the assumptions of kinetic theory under all conditions. You will learn how real gases differ from the ideal gases on which the gas laws are based.

11. Ideal Gases
To calculate the number of moles of a contained gas requires an expression that contains the variable n.
The gas law that includes all four variables—P, V, T, and n—is called the ideal gas law.
The ideal gas constant (R) has the value 8.31 (L·kPa)/(K·mol).

12. Sample Problem

13. Sample Problem

14. Sample Problem

15. Sample Problem

16. You Try!
Click Here for Stimulation

17. Ideal Gases and Real Gases
There are attractions between the particles in an ideal gas. Because of these attractions, a gas can condense, or even solidify, when it is compressed or cooled.

18. Ideal Gases and Real Gases
Real gases differ most from an ideal gas at low temperatures and high pressures.

19. Practice
An aerosol spray can with a volume of 325 mL contains 3.00 g of propane (C3H8) as a propellant. What is the pressure in atm of the gas in the can at 28°C?
524 kPa
kPa
475 kPa
0.524 kPa

20. Practice
2. Find the volume of a gas in liters if 2.95 mol has a pressure of 77.0 kPa at a temperature of 52°C.
22.4 L
16.6 L
103 L
50.2 L

21. Practice
An ideal gas differs from a real gas in that the molecules of an ideal gas
have no attraction for one another.
have a significant volume.
have a molar mass of zero.
have no kinetic energy.

22. Quick Lab Carbon Dioxide from Antacid Tablets Purpose:
To measure the amount of carbon dioxide gas given off when antacid tablets dissolve in water.
Caution: If you are allergic to latex, do not handle the balloons.

23. Homework
Ideal Gas Law Worksheet

24. Summary Questions Did we accomplish the objective? Explain.
What is the equation used to represent the Ideal gas Law?
What is the number used for R in the ideal gas law?
Compare and contrast Real gases to Ideal gases.