1. Temperatures must be in Kelvin!
VIDEO
Gay-Lussac’s Law P
There is a direct relationship between the temperature and pressure of a gas (if one increases so does the other)
If volume is held constant:
P1 = P2
T1 T2
Temperatures must be in Kelvin!
KMT – increasing the temperature gets the particles moving faster causing an increase in the number and energy involved in collisions; thus an increase in pressure

2. Example
A gas exerts 1.2 atm of pressure. If the temperature is raised from 25oC to 100oC, find the new pressure.
P1 = P2
T1 T2
P1 =
T1 =
P2 =
T2 =
1.2atm
298K
1.2atm = P
298K K
P = 1.5 atm ?
373K

3. A fixed volume of gas exerts a pressure of 1
A fixed volume of gas exerts a pressure of 1.00 atm at a temperature of 25ºC. What is the pressure of the gas when it is heated to 100ºC?
Multiple Choice F
iRespond Question
A.) atm
P = P
T T
1atm = P
298K K
B.) 1.25 atm
C.) 2.50 atm
D.) 4.00 atm
E.)

4. Which will always decrease the volume of a sample of methane gas which occupies a volume of 2.4 L at 25 °C?
iRespond Question F
Multiple Choice
A.) An increase in pressure and an increase in temperature
B.) A decrease in pressure and a decrease in temperature
C.) An increase in pressure and a decrease in temperature
D.) A decrease in pressure and an increase in temperature
E.)

5. Try To Explain This!
The water vapor is removed when cooling causing a decrease in pressure inside the can. The internal pressure is no longer able to resist the atmospheric pressure, causing a collapse.