1. V. Combined and Ideal Gas Law

2. **Standard T and P (STP)
Recall that STP is 1 atm and 0oC
0oC = 273 K
1 mole = 22.4 STP

3. STP Problem #1
How many liters will 3.33 moles of Neon gas occupy at STP?

4. STP Problem #2
How many moles of fluorine gas will be contained in a 1.30 liter flask at STP?

5. A. The Combined Gas Law Pressure units must be the same
Volume units must be the same
Temperature must be in Kelvin

6. A. The Combined Gas Law
Boyle’s Law
(temperature remains constant )

7. A. The Combined Gas Law
Gay-Lussac’s Law
(volume remains constant )

8. A. The Combined Gas Law
Charles’ Law
(pressure remains constant )

9. Combined Gas Law Problem #1
The volume of a gas-filled balloon is 30.0 L at 40oC and 3 atm. What would the volume be if the balloon was reduced to STP?

10. Combined Gas Law Problem #2
A 5.00 L air sample has a pressure of 107 kPa at a temperature of -50.0˚C. If the temperature is raised to 102˚C and the volume expands to 7.00 L, what will the new pressure be?

11. B. Ideal Gases
Ideal gases are imaginary gases that perfectly fit all of the assumptions of the kinetic molecular theory
Gases consist of tiny particles that are far apart relative to their size
All collisions (between particles and the walls) are elastic collisions (no energy lost)

12. B. Ideal Gases Cont. Gas particles are in constant random motion
No forces of attraction between gas particles
Average kinetic energy depends on temperature

13. C. Real Gases Real gases DO experience attractions between particles
Real gases DO have volume
Real gases DO NOT have elastic collisions

14. PV = nRT D. The Ideal Gas Law = 8.314 L∙ kPa mol ∙K
P = pressure
V = volume (in liters)
n = number of moles
R = Ideal Gas constant
= L∙ kPa mol ∙K
= L∙ atm mol ∙K
T = temperature (in Kelvin)
**If there are moles or mass in your gas law problem, use the IDEAL GAS LAW**

15. R = L∙ kPa mol ∙K
R = L∙ atm mol ∙K
Ideal Gas Law Problem #1
Calculate the number of moles of gas contained in a 3.0 L vessel at 300 K and a pressure of 152 kPa.

16. R = L∙ kPa mol ∙K
R = L∙ atm mol ∙K
Ideal Gas Law Problem #2
What pressure in atmospheres (atm) will g of methane (CH4) exert when it is compressed in a L tank at a temperature of 45°C?