Virtual Laboratory: Kinetic Theory of Gases
Overview
In this experimental module you will be working with particles inside
a balloon that is at constant volume (unless you pop it).
This simulation has opened in a separate window from the
text you are reading now.
You can control the temperature of the gas in the balloon by
using the thermometer. Gauges read out the pressure inside the
balloon as well as the mean particle speed (MPS). A graph shows the
distribution of particle speeds. The peak of that graph
is approximately the same as the mean particle speed.
This applet is designed to demonstrate what the concept of
temperatures is, how pressure is related to temperature under
conditions of fixed volume and how the distribution of
particle speeds depends on the temperature.
The user controls only one thing in this applet  the temperature
of the gas inside the balloon.
Note that
this experiment has a failure mode: if the pressure inside the
balloon exceeds 150 units the balloon will pop (you will hear that).
To recover from the popped condition, simply
lower the thermometer temperature
The experimental procedure is fully outlined below. Please follow
the instructions closely.
Technical Details
 You should run this applet in Netscape 4.6 or higher and/or
IE4.0 or higher.
 Note that you can not print an applet. Thus when you see your graph
build up, you can't just print that. If you know how to make a screen
capture, you could capture the screen and print that if you like. This
is not a requirement for this assignment. Just be aware that you can't
print your results and therefore you will have to record them in another
way, as specified in the instructions below.
 This is a JAVA applet meaning that if you are doing this at home,
once the code has been downloaded to your browser it will run even
if you disconnect from the Internet.
Experimental Instructions
In this applet the following quantities are readout in gauges:
 The thermometer records the temperature of the gas
in units of degrees kelvin
 The mean particle speed (MPS) is given in meters per second
 The pressure guage records the pressure in units of Pascals
There are 100 particles in the balloon at an initial temperature
of 300K. Disregard the graph for the present set of exercises.
Email your results to the instructor:
Temperature vs. Pressure at Fixed
Volume
 Record the initial pressure
 Raise the temperature to 600K and record the pressure.
 Raise the temperature to 900K and record the pressure.
 Raise the temperature to 1200K and record the pressure.
 Raise the temperature to 1500K and record the pressure.
 Predict at what temperture the pressure will pop the
balloon (i.e. be 150).
Reset the temperature to 300K and hit the
clear graph button.
Temperature vs mean particle speed at Fixed Volume
 Record the initial MPS
 Raise the temperature to 600K and record the MPS and note
the behavior of the graph.
 Raise the temperature to 900K and record the MPS and note
the behavior of the graph.
 Raise the temperature to 1200K and record the MPS and note
the behavior of the graph.
 Raise the temperature to 1500K and record the MPS and note
the behavior of the graph.
 Raise the temperature to 1800K and record the MPS and note
the behavior of the graph.
 If you double the temperature does the MPS double? If not,
by what factor does it increase (i.e. 10%, 20%, etc ...).
 Determine a functional relation between MPS and temperature.
This relation will be nonlinear and of the form
T a MPS^{n}
Determine from the experimental data you that just took what the value of
n is likely to be.
 Now qualitatively describe how the graph, which is showing the
distribution of particle speeds, behaves as the temperature increases.
(ignore the red vertical line on the graph).
 Now hit the clear graph button and reset the temperature to
400K.
 Raise the temperature to 1200K
 Count the approximate number of boxes that are under the purple
curve and under the white/yellow curve. In doing this you are measuring
the amount of area under these curves (in calculus this is called an
integral).
 Compare the two counts. Note that the Yaxis is the number of
particles per cubic centimeter that are at some velocity.
What might this comparison be telling you about the distribution of
particle energies in this enclosed volume.
Yes, this is an advanced question which I don't expect anyone to
answer correctly but I expect you to try.

Lastly do this one