1. Opening thoughts… Seen a hot air balloon?
Have you ever:
Seen a hot air balloon?
Had a soda bottle spray all over you?
Baked (or eaten) a nice, fluffy cake?
These are all examples of gases at work!

2. Properties of Gases Pressure Volume Temperature Amount (moles)
You can predict the behavior of gases based on the following conditions:
Pressure
Volume
Temperature
Amount (moles)

3. Pressure
Pressure is defined as the force exerted over a given area The SI unit for pressure is the Pascal, Pa.
Atmospheric pressure results from the mass of air being pulled toward the earth by gravity
Measured with an instrument called a barometer
Atmospheric pressure varies with altitude

4. Pressure Units Instruments often contain mercury, Hg
If you’ve ever inflated a tire, you’ve probably made a pressure measurement in pounds (force) per square inch (area). 1 atm =14.69 psi
Pressure Units
Instruments often contain mercury, Hg
Torr and mmHg are interchangeable
760 torr = 760 mmHg= 1 atm = 101.3Kpa
The pressure in a tire is measured to be 28 psi. Represent this pressure in atmospheres, torr and kPa.
On a summer day in Breckinridge, CO, the atmospheric pressure is 525 mmHg. What is this air pressure in atmospheres?

5. Boyle’s Law
This law is named for Boyle, who studied the relationship between pressure, p, and volume, V, in the mid-1600s.
Boyle determined that for the same amount of a gas at constant temperature, there is an inverse relationship between pressure and volume
pressure
volume

6. Boyle’s Law at Work…
Doubling the pressure reduces the volume by half. Conversely, when the volume doubles, the pressure decreases by half.
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7. P1V1 = P2V2 Formula for Boyle’s Law
A balloon has a volume of 456 ml at a pressure of 1.0 atm. It is taken under water in a submarine to a depth where the air pressure in the submarine is 3.3 atm. What is the volume of the balloon? Assume constant temperature.

8. Charles’ Law
This law is named for Jacques Charles, who studied the relationship volume, V, and temperature, T, around the turn of the 19th century.
This defines a direct relationship: With the same amount of gas he found that as the kelvin temperature increases the volume also increases. If the kelvin temperature decreases than the volume also decreases.
volume
temperature
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9. Charles’ Law at Work…
As the temperature increases, the volume increases. Conversely, when the temperature decreases, volume decreases.
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10. Formula for Charles’ Law
V1 = V2
T T2
A man heats a balloon in the oven. If the balloon initially has a volume of 0.4 liters and a temperature of 20.0 °C, what will the volume of the balloon be after he heats it to a temperature of °C?

11. Gay-Lussac’s Law P1 = P2 T1 T2
When increasing the temperature of molecules- the force of the molecules hitting their container increases and this increases the pressure. This relationship is called Gay- Lussac's Law
P1 = P2
T T2
At a temperature of -33°C a sample of a confined gas exerts a pressure of 53.3kPa. IF the volume remains constant, at what temperature will the pressure reach 133 kPa?

12. Gay Lussac

13. temperature of 200 K, and then I raise the pressure to 14 atm and
Combined Gas Law
This is where we consider both circumstances of pressure and temperature
P1V1 = P2V2
T T2
1) If I initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a
temperature of 200 K, and then I raise the pressure to 14 atm and
increase the temperature to 300 K, what is the new volume of the gas?