# How does the change in the number of gas particles change the pressure of gas in a glass beaker

by ign0r (student)

Lakichevich, Savva

IB Physics HL 2

September 27, 2012

How does the change in the number of gas particles

change the pressure of gas in a glass beaker

The point of this experiment is to see the dependence of pressure on the change of the number of particles of air. The expected result is a direct proportionality. Gas behavior can be described within the terms of pressure (P), volume (V), number of particles (n) and temperature (T):

Where R is the gas constant, and it is equal to 8.31. In order to find the dependence of pressure on the amount of air, we divide both sides by V:

needs to be controlled so as to determine the dependence only between pressure and the number of particles. Implied by the name, the gas constant is constant. Putting water into the beaker will control the temperature because of the high heat capacity of water and the low heat capacity of air. The beaker that is made of glass will keep the volume the same.

Variables:

Independent variable

The amount of air in the beaker

Dependent variable

Pressure in the beaker

Controlled variables

Materials:

275 mL beaker

75 mL of water

Pressure gage

20 mL Syringe

Thermometer

Procedure:

Measure the temperature of air

Put 75 mL of water into the beaker

Make sure it is approximately the same temperature as of the air

Set up the pressure gage and the syringe like shown in the diagram below

Pull out 20 mL of air out of the beaker 5 times, and record the pressure every time air is sucked out of the beaker

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