PHYS 1401
General Physics I
EXPERIMENT 11
BOYLE’s LAW
I. INTRODUCTION
The objective of this experiment is to study the relationship between the pressure
and volume of an air sample at constant temperature. This will be done by measur-
ing the pressure of a constant amount of air contained in a cylinder as the volume
of the air is varied. The results will be compared with the predictions of Boyle’s
law and the ideal gas law.
II. THEORY
Boyle’s law states that, for constant temperature, the product of the volume and
the pressure of an ideal gas is a constant.
PV =C(1)
The ideal gas law
PV =nRT (2)
states that this constant (nRT)is proportional to the amount of ideal gas in the sam-
ple (the number of moles, n) and the absolute temperature, T. The constant Rin
this equation is the universal gas constant which has a value of R=8.31 J/(mole.K)
in SI units. Note that if Tis held constant throughout the experiment, then the ideal
gas law reduces to Boyle’s law.
III. APPARATUS
Pressure sensor, syringe and computer.
IV. EXPERIMENTAL PROCEDURE
1. Connect the open end of the syringe to the pressure sensor. Open the valve
and pull the plunger back to set the initial volume of the air in the cylinder
at 20.0 cm3. Close the valve.
2. Connect the pressure sensor to Channel (1) of the LabPro.
3. Open the following folders and programs: Logger pro, then Experiments,
then Probes and Sensors, then Pressure Sensors and Boyle’s Law. Click ok
on sensor confirmation.
4. Before you start taking data, make sure that the volume of the air is still
20.0 cm3. If not make the necessary adjustments to restore the volume to
20.0 cm3.
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