1. Pressure and Temperature

2. The Effects of Increasing the Temperature of a Sample of Gas at Constant Volume

4. Temperature and Pressure
What would happen to the pressure in a sealed container (i.e. volume remains constant) if heat is added?
Graph the following data:
Temperature (K)
Pressure (kPa)
129
111
301
242
403
323
501
429
601
517
704
613

5. Pressure is directly proportional to temperature (in Kelvins) P  T
Pressure increases proportionally as temperature increases, provided volume and amount remain constant.
Pressure is directly proportional to temperature (in Kelvins)
P  T
A direct relationship
P = kT
P = k T
P1 = P2
T1 T2

6. A gas cylinder with a pressure of 1000kPa at 25°C is placed in a boiling water bath. What will the new pressure reading be?
P1 = 1000kPa T1 = = 298K
P2 = ? T2 = = 373K
P2 = 1000kPa x 373 K
298 K
P2 = 1252 kPa
P1 = P2
T1 T2

7. Combined Gas Law

8. Boyle’s Law:
PV = K P1V1=P2V2
Charles’ Law:
V =K V1/T1=V2/T2 T
Pressure-Temperature Law:
P = K P1/T1=P2/T2 T

11. Combined Gas Law
P1V1 = P2V2
T T2
An aerosol can with a volume of 325 mL at 12°C and a pressure of 250 kPa is released into a room at 25°C and 101 kPa. Determine the new volume?
P1= 250 kPa P2 = 101 kPa
V1 = 325 mL = 0.325L V2 =
T1 = = 285K T2 = = 298 K
V2 = 0.325L x (250 kPa)(298 K)
(101 kPa) (285K)
V2 = .841L

12. Example
An inflated baloon has a volume of 6.0 L at sea level (1.0 atm) and is allowed to scend in altitude until the pressure is 0.45 atm. During ascent the temperature of the gas falls from 22 to -210C. Calculate the volume of the baloon at its final altitude.

13. Example
A 0.50 mol sample of oxygen gas is confined at 0oC in a cylinder with a movable piston. The gas has an initial pressure of 1.0 atm. The gas is then compressed by the piston so that its final volume is half the initial volume. The final pressure of the gas is 2.2 atm What is the final temperature of the gas?