1. Boyle Charles Gay-Lussac Avogadro Dalton’s Graham’s Law
The Gas Laws
Boyle
Charles
Gay-Lussac
Avogadro
Dalton’s
Graham’s Law

2. Boyle’s Law
Pressure and Volume have an inverse relationship in gases
P1V1 = P2V2
If temperature and # particles is the same, if you increase pressure, the volume will decrease and vice versa

3. Charles’ Law
Temperature and Volume have a direct relationship
V1 = V2
T1 = T2
If P and n are constant, If you decrease the temperature, the volume will decrease.

4. Gay-Lussac’s Law P1 = P2 T1 = T2
Direct relationship between pressure and temperature
P1 = P2
T1 = T2
If the temperature increases, the pressure will increase as well and vice versa.

5. Avogadro’s Law
At the same temperature and pressure, gases occupying the same volume must have the same number of PARTICLES
The same number of collisions must be happening.
V = kn where k is a proportionality constant
I mol of any STP = 22.4 L

6. Gas Laws
Boyle’s Law, Charles Law and Gay-Lussac’s Law can be calculated independently from the COMBINED GAS LAW
P1V1 = P2V2
T1 = T2

7. Gas Laws
Boyle’s Law
P1 V1 = P2 V2
T1 = T2

8. Gas Laws
Charles’ Law
P1 V1 = P2 V2
T1 = T2

9. Gas Laws
Gay Lussac’s Law
P1 V1 = P2 V2
T1 = T2

10. Graham’s Law
Diffusion – the movement of particles from regions of higher density to regions of lower density
Effusion – the passage of a gas under pressure through a tiny opening
Graham’s Law of diffusion – the rate of diffusion of a gas is inversely proportional to the square root of the gas’s density
Heavy molecules effuse and diffuse slower than smaller molecules

11. Sample Problem – Graham’s
Air is a mixture of many gasses. Nitrogen, oxygen and carbon dioxide are the largest components of air.
If a balloon is filled today with air allowed to sit overnight, some of the gas will escape through tiny holes in the rubber. What gas would you expect to find the LEAST of inside the balloon the next day.
What gas would you expect to find the most of?

12. Dalton’s Law of Partial Pressures
Partial Pressure – the pressure of each gas in a mixture
The total pressure of a gas is a sum of the pressure of its parts
Ptotal = PA + PB + PC +…..

13. Dalton’s Practice Problem
A mixture of oxygen, carbon dioxide and nitrogen gases has a total pressure of 0.97 atm. What is the partial pressure of oxygen if the partial pressure of carbon dioxide is 0.70 atm and the partial pressure of nitrogen is 0.12 atm?

14. A given sample of gas occupies 523 mL at 1. 00 atm
A given sample of gas occupies 523 mL at atm. The pressure is increased to 1.97 atm, while the temperature remains the same. What is the new volume of the gas?

15. A sample of oxygen gas has a volume of 150. 0 mL at a pressure of 0
A sample of oxygen gas has a volume of mL at a pressure of atm. What will the volume of the gas be at a pressure of atm if the temperature remains constant?

16. A balloon is inflated to 665 mL volume at 27°C
A balloon is inflated to 665 mL volume at 27°C. It is immersed in a dry-ice bath at -78°C . What is its volume, assuming the pressure remains constant?

17. Helium gas in a balloon occupies 2. 5 L at 300. 0K
Helium gas in a balloon occupies 2.5 L at 300.0K. The balloon is dipped into liquid nitrogen that is at a temperature of 80.0K. What will the volume of the helium in the balloon at the lower temperature be?

18. An airosol can containing gas at 101 kPa and 22°C is heated to 55°C
An airosol can containing gas at 101 kPa and 22°C is heated to 55°C. Calculate the pressure in the heated can.

19. At 122°C the pressure of a sample of nitrogen is 1. 07 atm
At 122°C the pressure of a sample of nitrogen is 1.07 atm. What will the pressure be at 205°C assuming constant volume?