Name ____________________________________________________ Date ___________ Period ___________
Gas Laws:
Boyle’s and Charle’s Law
(Notes)
Boyle’s Law: Pressure and Volume
Boyle’s law states that the pressure and volume of a gas at constant temperature are inversely
proportional (inverse relationship). PV = k, where k is a constant value.
Inverse Relationship:
• As pressure increases, volume decreases
• As pressure decreases, volume increases
We can use Boyle’s Law to compare:
• Volume (at 2 pressures)
• Pressure (at 2 volumes)
In mathematical terms, this law is expressed as follows (temperature and mass are held
constant):
P1V1 = P2V2
Sample problems:
1. A sample of compressed methane has a volume of 648 mL at a pressure of 503 kPa. To
what pressure (in kPa) would the methane have to be compressed in order to have a
volume of 216 mL?
2. Submarines need to be extremely strong to withstand the extremely high pressure of water
pushing down on them. An experimental research submarine with a volume of 15,000 L
has an internal pressure of 1.2 atm. If the pressure of the ocean breaks the submarine
forming a bubble with a pressure of 250 atm pushing on it, how big will that bubble be?
Charle’s Law: Temperature and Volume
Charle’s law states for a given amount of gas at constant pressure, the volume is directly
V
proportional to the temperature (in Kelvin).
= k , where k is a constant.
T
Direct Relationship
• Temperature increases, volume increases
• Temperature decreases, volume decreases
We can use Charle’s Law to compare:
• Temperature (at 2 volumes)
• Volume (at 2 temperatures)
In mathematical terms, this law is expressed as follows (pressure and mass are held constant):
V1 V2
=
T1 T2
K = oC + 273
Sample problems:
1. A weather balloon contains 5.30 kL of helium gas when the temperature is 12°C. At what
temperature (in °C) will the balloon’s volume have increased to 6.00 kL?
2. How hot will a 2.3 L balloon have to get to expand to a volume of 400 L? Assume that the
initial temperature of the balloon is 25°C.
2