1. Explaining behavior of specific fluids.
Gas laws

2. Gas Laws What is Charles’ Law?
The volume of a gas is directly affected by the temperature.
V/T = K
V/T (start) = V/T (finish)
A 3.0 L balloon is lifted from room temperature (22 C) to the top of Pikes Peak (2.0 C). What will the new volume be?
Always use Kelvin for temperature.
2.8 L

3. Gas Laws What is Boyle’s Law?
Boyle’s Law shows the inverse relationship between pressure and volume
PV = k
PV (start) = PV (end)
If you take a 2.5 L ball from the surface of the ocean at 1.0 atm a depth with a pressure of 18.0 atm, how much will the volume change?
Always use the same units.
The new volume is .14 L so it decreased 2.4 L.

4. Gas Laws What is Gay Lussac’s Law?
This law shows the direct relationship between pressure and temperature.
P/T = k
P/T (start) = P/T (end)
A bike tire is inflated from 1.0 atm to 4.0 atm. The original temperature was 20.0 C. What is the final temperature?
Always use Kelvin.
1200 K

5. Gas Laws What is the combined gas law?
The combined gas law takes all three laws and puts them into one equation.
PV/T (start) = PV/T (end)
If a diver takes a bag of chips with an initial pressure of 3.0 atm, a volume of 2.0 L, and a temperature of 23 C to the bottom of the sea with a pressure of 19.0 atm and a temperature of 1 C, what would the new volume be?
.3 L

6. Gas Laws What is Avogadro’s Law?
This law states that the molecules of a gas at STP is directly proportional to the volume of gas.
V/n = k
V/n (start) = V/n (end)
What happens to the volume of a gas when you double the number of particles at the same pressure and temperature?
Volume should double.

7. Gas Laws What is the ideal gas law?
The ideal gas law combines Avogadro’s Law with the combined gas law.
PV = nRT
R is a constant that depends on the units used in the question.
R = L atm/mol K
R = L kPa/mol K
R = 62.4 L mmHg/mol K

8. Gas Laws
A gas occupies 3.45 L at 1.12 atm and 34 C. What is the number of moles of this gas if it is behaving ideally?
What units are we using?
What is the value of R?
What should temperature be in?
The answer is. . .
.15 mol

9. Gas Laws How can you tell what gas law you need to use?
The gas law is determined by the givens and the unknown.
Use the law that best fits the information given.