PV ' constant when temperature is held fixed
P1V1 ' P2V2 ' constant
P1V1 ' (400 torr)(12.3L) ' (600torr)V2 ' P2V2
V2 ' 8.20L
cylinder
piston
Ideal
Gas
V1 at
temp1
P1
Ideal
Gas
V2 at
temp2
P1
Temp2 >Temp1
at constant
pressure
CHE 115 Gaseous State
2
Note: At any point on the curve the pressure times the volume equals the constant 24.5.
This equation is the mathematical expression of Boyle’s law - at constant temperature the
volume occupied by a fixed weight of a gas is inversely proportional to the pressure exerted on
it.
Boyle’s law describes the behavior of an ideal gas and approximates the behavior of a real gas.
The approximation is very poor at high pressures and low temperatures.