1. Gas Laws Review

2. Volume Decreases, Pressure Increases
Boyle’s Law
The volume of a sample of gas is inversely proportional to its pressure, if temperature remains constant
Volume Decreases, Pressure Increases
Volume Increases,
Pressure Decreases

3. Boyle’s Law Formula-Reference Table
P1 V1 = P2 V2

4. Example
A sample of gas collected in a 350 cm3 container exerts a pressure of 103 kPa. What would be the volume of this gas at 150 kPa of pressure? (Assume that the temperature remains constant.)
P1 V1 = P2 V2
P1 = 103 kPa
V1 = 350 cm3
P2 = 150 kPa
V2 = x
(103)(350) = (150)(x)
V2 = cm3

5. Charles Law
The volume of a sample of gas is directly proportional to its Kelvin temperature, if pressure remains constant.
Volume Increases, Temperature Increases
Volume Decreases, Temperature Decreases

6. Charles Law Formula-Reference Table
V1 / T1 = V2 / T2
V = Volume of gas (L)
T = Temperature of gas (K)

7. Example
4.40 L of a gas is collected at 50.0°C. What will be its volume upon cooling to 25.0°C?
V1 / T1 = V2 / T2
V1 = 4.40 L
T1 = 323 K
V2 = x
T2 = 298 K
K = °C+ 273
(Reference Table)
(4.40)/(323) = (x)/(298)
V2 = 4.09 L

8. Combined Gas Laws-Reference Table
P1V1 / T1 = P2V2 / T2
V = Volume of gas (L)
T = Temperature of gas (K)

9. Example P1 = 12 atm V1 = 23 L T1 = 200 K P2 = 14 atm V2 = ? T2 = 300 K
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?
P1 = 12 atm
V1 = 23 L
T1 = 200 K
P2 = 14 atm
V2 = ?
T2 = 300 K
(12)(23) = (14)(V2)
V2 = L

10. Equation is on the Reference Table
Ideal Gas Law Equation
Equation is on the Reference Table

11. Gas Constant Value See Reference Table
L atm
mole K
0.0821
L mmHg
mole K
62.4
8.314
L kPa
mole K
What is the difference between each constant?

12. Example #1
How many moles of N2 are in a 750 mL vessel at 26 degrees Celsius and 625 mm Hg?
P = 625 mmHg
V = 750mL  L
n = ?
R = 62.4 L mmHg
mol K
T = 26°C  299 K
(625)(0.75) = (n)(62.4)(299)
= ( )(n)
N = mol

13. Dalton’s Law Formula
See Reference Table

14. Dalton’s Law