2. #1. Boyle’s Law
Gas pressure is inversely proportional to the volume, when temperature is held constant.
Pressure x Volume = a constant
Equation: P1V1 = P2V2 (T = constant)

3. Graph of Boyle’s Law – page 418
Boyle’s Law says the pressure is inverse to the volume.
Note that when the volume goes up, the pressure goes down

4. - Page 419

5. Jacques Charles ( )
French Physicist
Part of a scientific balloon flight on Dec. 1, 1783 – was one of three passengers in the second balloon ascension that carried humans
This is how his interest in gases started
It was a hydrogen filled balloon – good thing they were careful!

6. #2. Charles’s Law
The volume of a fixed mass of gas is directly proportional to the Kelvin temperature, when pressure is held constant.
This extrapolates to zero volume at a temperature of zero Kelvin.

7. Converting Celsius to Kelvin
Gas law problems involving temperature will always require that the temperature be in Kelvin. (Remember that no degree sign is shown with the kelvin scale.)
Reason? There will never be a zero volume, since we have never reached absolute zero.
Kelvin = C + 273
°C = Kelvin - 273
and

8. - Page 421

9. Joseph Louis Gay-Lussac (1778 – 1850)
French chemist and physicist
Known for his studies on the physical properties of gases.
In 1804 he made balloon ascensions to study magnetic forces and to observe the composition and temperature of the air at different altitudes.

10. #3. Gay-Lussac’s Law
The pressure and Kelvin temperature of a gas are directly proportional, provided that the volume remains constant.
How does a pressure cooker affect the time needed to cook food? (Note page 422)
Sample Problem 14.3, page 423

11. #4. The Combined Gas Law
The combined gas law expresses the relationship between pressure, volume and temperature of a fixed amount of gas.
Sample Problem 14.4, page 424

12. The combined gas law contains all the other gas laws!
If the temperature remains constant... P1 x V1 P2 x V2 = T1 T2
Boyle’s Law

13. P1 x V1 P2 x V2 = T1 T26 Charles’s Law
The combined gas law contains all the other gas laws!
If the pressure remains constant... P1 x V1 P2 x V2 = T1
T26
Charles’s Law

14. P1 x V1 P2 x V2 = T1 T2 Gay-Lussac’s Law
The combined gas law contains all the other gas laws!
If the volume remains constant... P1 x V1 P2 x V2 = T1 T2
Gay-Lussac’s Law