1. Boyle’s Law CP Chemistry
Unit 7: Gas Laws
Boyle’s Law
CP Chemistry

2. Boyle’s Law
At constant temperature, the volume of a given amount of gas varies inversely with the pressure.
P1V1 = P2V2 (Temp. and gas particles are constant)
Pressure and Volume units must be the same on both sides of the equation!

3. Boyle’s Law Graph
Pressure vs. 1/volume
Slope = P
1/V
PV = Constant

4. Problem #1
A sample of helium gas in a balloon is compressed from 4.0L to 2.5 L at a constant temperature. If the pressure of the gas in the 4.0L volume is 2 atm, what will the pressure be at 2.5L?
P1V1 = P2V2
P1= 2atm P2= ? V1= 4.0L V2= 2.5L
(2atm)(4.0L) = (P2)(2.5L)
P2 = 3.2 atm
(2atm)(4.0L) = P2
(2.5L)

5. Sample Problem #2
A sample of carbon dioxide gas in a container is compressed at a constant temperature. If the initial volume is 560mls and the pressure of the gas changes from 830torr to 1250 torr, what will the new volume be?
P1V1 = P2V2
P1= 830 torr P2= 1250 Torr V1= 560mL V2= ? mLs
(830torr)(560mL) = (1250torr)(V2)
V2 = (830torr)(560mL)
(1250Torr)
V2 = 372 mLs

6. Boyle’s Law Video

7. Gas Properties link for take home lab