Name: _________________________ Period: ________ Date:______________________________
Kinetic Molecular Theory Webquest
(Let me know if there are any links that do not work.)
A. KMT and Phases
https://phet.colorado.edu/en/simulation/states-of-matter Click RUN simulation.
* Use Oxygen for the questions below.
1. Describe the motion of particles for the three phases of matter.
2. What phase(s) involve the atoms or molecules essentially being side by side?
3. What phase(s) involve the atoms or molecules with a LOT of space between them?
B. KMT and Solids :
*Using the Same Simulation now click on the middle tab Phase Changes
1. Describe what happens to the motion of the particles in the solid state as the temperature
increases. (You need to manipulate the temperature below the container.)
2. Why is it necessary to use the word "average" in the definition of temperature? (Temperature
- A measurement of the AVERAGE kinetic energy of a substance.)
3. Use this observation to explain why solids expand (get bigger) when heated, and contract (get
smaller) when cooled.
*Now Go Back to the Solids, Liquids, Gas Tab and choose water as your molecule.
4. If substance get smaller (more dense) as they get colder, why does water EXPAND when it
freezes (make it cooler)?
5. What unique property does this give a piece of ice (water's solid state), when it is put in liquid
water?
6. Why is this property unique (think about other solids, liquids states, what would happen if you
put a solid rock in water)?
D. KMT and Gases
https://phet.colorado.edu/en/simulation/gas-properties
1. Don't click on anything unless directed to do so! First, pump the handle ONE full pump. Note how
fast the blue gas atoms are moving around. Then, on the menu to the right, choose the "Light
Species" under "Gas in Pump", and give one more full pump. The blue spheres represent heavier
gas molecules, while the red spheres represent lighter gas molecules.
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A) What is different about the motion of the lighter molecules (red) verses the heavier molecules
(blue)?
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B) Which has more kinetic energy, a car moving slower, or a car moving faster?
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C) Temperature is a measurement of what?
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D) Since both types of gas molecules are in the same container, they have to be at the same
temperature. Which means they both have the same average kinetic energy. So, explain why the
red spheres are moving faster.
2. To determine how two variables are related, it is necessary to make sure they are the only two
things that are changing. Mess around with the animation and learn what things you can adjust.
Then determine little experiments that will study the relationships below. Explain how you
determined if the following relationships are "direct" or "inverse" (indirect).
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A) Pressure and temperature.
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B) Pressure and volume.
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C) Pressure and number of particles.
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D) Temperature and volume. (You will need to adjust the temperature and see what happens
to the volume. AND make sure the pressure is a "constant parameter".)
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E) Number of particles and volume.
3. See if you can change the temperature by adjusting the volume of the box. Describe your results.
4. Explain why a tire pump gets warm when you are filling up a bike tire or a ball.
5. Describe, using the KMT, why a balloon will shrink when it is brought outside into the cold air.
6. Why is it common for tires to need more air in the winter, and have some air let out during the
summer.
E. Kinetic Molecular Theory:
Go to http://phet.colorado.edu/en/simulation/gas-properties
1. Use the pump to put one pump of gas into the box.
What happens to the clump of particles?_____________________________________________
(To answer the following questions, keep your eye on one particle and notice how it moves.)_
How do the particles move? (straight line, circular, random, etc.)___________________________
Do the particles stay at a constant speed?______________
If not, what causes the speed to change?____________________________________________
Do they always move in the same direction?_________________
If not, what causes their direction to change?_________________________________________
2. a Using the settings on the right side of the screen, put 100 “heavy species” in the container. Give
it time for the pressure to stabilize.
b. Record the pressure_____________ ( The number will jump around- choose an average.)
c. Reset the number of “heavy species” to zero, and the “light species” to 100.
d. Record the pressure_______________
e. Does the mass of the particles significantly affect the pressure of the container? _____________
f. How can you explain this? _______________________________________________________
F. Partial Pressures
3a. Put 100 of “heavy species” and no “light species”.
b. Record the pressure. _____________
c .Put 50 of the “light species” and no “heavy species”
d. Record the pressure__________________
e. Put 50 “light species” AND 100 “heavy species” together. Record the pressure________________
c. How does this compare to the pressures from 3b. and 3d?_______________________________