1. Chap 11 Gas laws

2. Review of Gases New chap!!

3. The nature of gases… Gases all have common physical properties: Mass
Easily compressible
Take the shape of their container
Can move through other gases
Exert pressure
Pressure depends on temperature

4. The kinetic-molecular theory…
Explains the behavior of gas particles

5. Assumptions of K-M theory…
Gas consists of very small particles, each of which has a mass
Distances separating gas particles are relatively large
Gas particles are in constant, rapid, random motion
Collisions of gas particles with each other or container are perfectly elastic
Average kinetic energy of particles depends only on temperature of the gas
Gas particles exert no force on one another

6. Measuring Gases

7. Measuring gases… 4 variables: Amount of gas (n) Volume (V)
Temperature (T)
Pressure (P)

8. The gas laws… A useful bit of information:
Conditions for STP are 0.00 C and 1.00 atm

9. Combined Gas Law

10. The gas laws…
The combined gas law – relates pressure, volume, and temperature
formula:
(P1V1) = (P2V2)
T1 T2

11. The combined gas law Sample Problem:
The volume of a gas-filled balloon is 30.0 L at 40. C and 153 kPa. What volume will the balloon have at STP?

12. The combined gas law… Sample Problem:
(153 kPa × 30.0 L)/313 K = (101.3 kPa × V2)/273 K
((153 kPa × 30.0 L)/313 K) × (273 K/101.3 kPa) = L

13. The combined gas law… Sample Problem:
A gas occupies a volume of mL at 316 K and 4.89 atm. What volume will it occupy at STP?

14. The combined gas law… Sample Problem:
(4.89 atm × mL)/316 K = (1.00 atm × V2)/273 K
((4.89 atm × mL)/316 K) × (273 K/1.00 atm) = mL