1. Unit 12: Gas Laws
Section 1: Gas Pressure

2. What is Pressure?
To create the most pressure,
Ms. Stark should wear which shoes?
P = F A
Gas pressure is caused by _________ with the _____ of the container.
Like density
collisions
P = F A
P = F A
walls

3. Atmospheric Pressure: weight of air per area
empty space
(a vacuum)
weight of Hg h
760 mm
Atmospheric Pressure
(weight of air)
Atmospheric Pressure:
weight of air per area

4. You can’t drink through the straw unless the atmosphere pushes the liquid.
WHY no flow?

5. Units at Sea Level: 1 atm 760 mmHg 760 torr 101.3 kPa 1 Pascal =
Same pressure as a large truck in one inch
1 Pascal =
1 Newton of force
1 m2 of area
14.7 psi

6. Pressure Conversions 1 atm = 760 mmHg = 760 torr = 101.3 kpa
What is 475 mmHg expressed in atm?
What is 103 kPa expressed in atm?
1 atm =
760 mmHg
475 mmHg x
0.625 atm
103 kPa x
1 atm =
101.3 kPa
1.02 atm

7. Pressure Conversions 1 atm = 760 mmHg = 760 torr = 101.3 kpa
What is 720 mmHg expressed in kPa?
4. What is 2.30 atm expressed in torr?
101.3 kPa =
760 mmHg
720 mmHg x
96.0 kPa
2.30 atm x
760 torr =
1 atm
1748 torr

8. # of Particles Volume Temp Particles ... Volume ..… Temp .…….
(collisions)
Pressure
Particles ...
Volume ..…
Temp .…….

9. Quick Quiz! 1) Gas pressure is affected by…
A) temp, volume, and molar mass.
B) temp and number of particles.
C) volume and size of container.
D) temp, volume, and # of particles. 9

10. Quick Quiz. 2) If 1 atm = 760 mmHg, then how many atm is 747 mmHg?
A) 567,720 atm
B) atm
C) atm
D) atm’s fo’ money yo’
747 mmHg x 1 atm =
760 mmHg 10