1. Unit 14: Gas Laws Pressure 3 Gas Laws Combined Gas Law (calculations)
Print 1-3, 5, 7, 9, 11-16

2. A. Pressure What is Pressure? Which shoes create the most pressure?
Like density
Which shoes create the most pressure?

3. Atmospheric Pressure: weight of air per unit area
Gravity
Atmospheric Pressure:
weight of air per unit area

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

5. A. Pressure
Measured with a barometer. At sea level: 1 atm 760 mmHg 760 torr kPa 14.7 psi
Same pressure as a large truck in one inch

6. A. Pressure What is 475 mmHg expressed in atm?
1 atm = 760 mmHg = 760 torr = 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. A. Pressure What is 720 mmHg expressed in kPa?
1 atm = 760 mmHg = 760 torr = kpa
What is 720 mmHg expressed in kPa?
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. A. Pressure What causes Pressure?
collisions of particles with walls of container.
# of Particles
Volume
Temp

9. Increasing these causes…
A. Pressure
effect on Pressure
Increasing these causes…
# of Particles …..….
Volume ..……………
Temp .……………….

10. Quick Quiz. 1) 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’, not emm’H’gees
747 mmHg x 1 atm =
760 mmHg 10

11. Quick Quiz. 2) Gas pressure is affected by
A) temp, volume, and molar mass.
B) temp and # of particles.
C) volume and size of container.
D) temp, volume, and # of particles. 11

12. B. Boyle’s Law (Pressure & Volume)
P ↑ as V ↓
As the volume of the air trapped in the pump is reduced, its pressure goes up, and air is forced into the tire.

13. B. Boyle’s Law (P & V)

14. C. Charles’ Law (Volume & Temp)
V ↑ as T ↑
Temps must be in Kelvin!
A balloon shrinks when submerged in cold water

15. C. Charles’ Law (V & T)

16. D. Gay-Lussac’s Law (Pressure & Temp)
P ↑ as T ↑
Temps must be in Kelvin!

17. D. Gay-Lussac’s Law (P & T)
In a pressure cooker, food cooks faster than in an ordinary pot with a lid.
pressure cooker

18. E. Combined Gas Law (P, V, & T)
P, V, & T calculations

19. E. Combined Gas Law (P, V, & T)
P, V, & T calculations
Boyle’s Law

20. E. Combined Gas Law (P, V, & T)
P, V, & T calculations
Charles’ Law

21. E. Combined Gas Law (P, V, & T)
P, V, & T calculations
Gay-Lussac’s Law
We add in Avogadro’s Law (n) tomorrow

22. E. Combined Gas Law (P, V, & T)
P, V, & T calculations
A 5.00 L balloon is filled with gas at atm and 25oC.
What is the balloon’s volume at STP?
STP = Standard Temp. & Pressure
0oC (273 K) & 1 atm

23. E. Combined Gas Law (P, V, & T)
P, V, & T calculations
A 5.00 L balloon is filled with gas at atm and 25oC.
What is the balloon’s volume at STP?
(0.855 atm)(5.00 L)
(298 K)
(1 atm) V2
(273 K) =
(0.855 atm)(5.00 L)(273 K)
(298 K)(1 atm) = V2 =
3.92 L

24. Quick Quiz!
1) A balloon is slightly smaller when moved from a mountaintop to the seashore. The gas law that explains this change is…
A) Gay-Lussac’s Law.
B) Boyle’s Law.
C) Charles’ Law.
D) Brock's Law .
You’re on the clock. Get to work!
Do or do not. There is no try. 24

25. Quick Quiz.
2) If the temperature of a gas in a flexible container were doubled, the volume of the gas would be
A) halved.
B) doubled.
C) the same.
D) stupid anyway. 25

26. Quick Quiz.
3) If the pressure of a gas in a flexible container were doubled, the volume of the gas would be
A) halved.
B) doubled.
C) the same.
D) when am I gonna use this stuff anyway. 26