Charles' Law

Charles' Law says that temperature and volume vary directly. This is true at constant pressure only. The temperature for all problems using this law must be in Kelvin. The conversion for this is: C + 273.15 = K. As temperature increases, the gas gains energy. This makes it contact with the side of the container more and want to expand. The formula we use for these problems is:

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Example: Gas at 15C and 1 atm has a volume of 2.58L. What volume will it have at 38C and 1 atm?

T1=15+273.15=288.15K   V1=2.58L   T2=38+273.15=311.15K   V2=?

(2.58)(311.15)/(288.15) = 2.79L

Here are a few more practice problems like the one above!

Boyle's Law

Boyle's Law says that the relationship between pressure and volume is inverse. It deals with only two of the four variables that determine the state of a gas. The only gas that actually holds to this relationship is an ideal gas at low pressure. The equation used for this law is:

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Example: Pressure on the peak of Mt. Everest is 150mmHg. If climbers carry 10.0 L tanks with a pressure of 3.04x10^4 mmHg, what will be the volume of the oxygen when it's released?

V1=10.0L   V2=?   P1=3.04x10^4mmHg   P2=150mmHg

10(3.04x10^4) = V2(150)   =   2.0x10^3 L

Here are some more practice problems for these

Combined Gas Law

The Combined Gas Law is used to deal with changes in all of the variables: moles, temperature, pressure, and volume. The formula we use to calculate this is:

Source

Example: A bubble rises from the bottom of a lake when temperature and pressure are 8C and 6.4 atm. The bubble reaches the surface where it is 25C and 1atm. What's the final volume of the bubble if the initial was 2.1mL?

P1=6.4atm   V1=2.1mL   T1=8+273.15=281.15C    P2=1.00atm   V2=?   T2=25+273.15=298.15C

6.4(2.1)298.15=1(V2)281.15   =    14mL

Here are more practice problems