Page 2
Materials:
• Empty pop can (or large metal container with a lid)
• Aluminum pie plate
• Hot plate or Bunsen burner
• Wire gauze square held by a support ring and stand
• Beaker tongs
• Water
(Tip: Add ice to your water for an even more astounding result.)
Procedure:
1. Add water to an empty pop can until the bottom is covered to a depth of~1 cm.
2. Using a hot plate, heat the can to the point that steam is visible from the opening. A Bunsen burner can be used to heat
the can but do not heat the can directly with the flame. Place the can on a wire gauze square that is held by a support ring
and stand.
3. Continue heating for a minute. Then, using beaker tongs, carefully and quickly invert the can in an aluminum pie plate
containing water (or a plastic dish tub half-filled with water).
Expected Results:
When the can is inserted into the liquid, it is crushed in a spectacular demonstration of atmospheric pressure.
Students will be amazed to see that a small amount of water boiled inside a soda can cause it to implode instantly when
submerged into cold water! The generation of steam pushes air out of the can. Upon inversion in the cold water, the steam
condenses back to liquid water, causing a decrease in pressure relative to its surroundings. The atmospheric pressure crushes the
can as a result.
Follow up:
• What's happening:
1. What is happening as you heat the water? (water boils)
2. What is coming out of the top of the can? (water vapor)
3. What happened to the can? (it was crushed)
4. Why was the can crushed?
• Predictions:
1. What will happen when I turn the can over and immerse it in cold water?
2. What would happen if the can was empty?
3. What would happen if the water was heated but not boiled?
• After students have made their predictions, repeat the experiment using the different variables mentioned in the above
questions. Have students observe and then explain the repeated experiments.
• Ask students to use the principles in this activity to explain why it's dangerous to heat or compact Aerosol cans.
What causes those pressurized cans to explode, and what happens to the propellant inside?
• Atmospheric pressure, changes of state. Help students visualize the changes in the particles both inside and outside
the can before and after heating.
Crushing Can (continued)
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