Bouncing Off the Wall Lab
Hypothesis: How do molecules respond to different physical
changes?
1. Go to the Phet website and download “Gas Properties”
simulation. It can also be found at
https://phet.colorado.edu/en/simulation/gas-properties
2. Using the air pump, add “some” molecules.
3. Describe 3 methods that cause the chamber to break.
4. Make pressure constant. What happens to the numerical value of temperature in the chamber
when you compress the gas (decrease volume)? Describe the mathematical relationship between
these two variables. Why does temperature change? Think about the molecules.
5. Make temperature constant. What happens to the numerical value of pressure when you
compress the gas? Describe the mathematical relationship between these two variables. Why
does pressure change? Think about the molecules.
6. Make temperature constant. What happens to the numerical value of pressure when you add
more molecules to the chamber? Describe the mathematical relationship between pressure and
number of molecules. Why does pressure change? Think about the molecules.
7. Make pressure constant. What happens to the numerical value of temperature when you add
more molecules to the chamber? Describe the mathematical relationship between temperature
and number of molecules. Why does temperature change? Think about the molecules.
8. Make Temperature constant. What happens to the numerical value of pressure when you heat
the gas? Describe the mathematical relationship between these two variables. Why does pressure
change? Think about the molecules.
9. Make Pressure constant. What happens to the numerical value of temperature when you heat
the gas? Describe the mathematical relationship between these two variables. Why does
temperature change? Think about the molecules.
10. The simulation doesn’t always keep the other variables constant. What other variable changed
when you added heat to the chamber? Explain how that variable is changed and why that variable
is changed.
11. Try steps #4-9 with different molecules. What molecule is most affected by changing pressure,
temperature, volume, and number of molecules? Hypothesize why.