20 L Can Crush, 2B30.15

Topic and Concept:

Statics Of Fluids, [:StaticsOfFluids#AtmosphericPressure: 2B30. Atmospheric Pressure]

Location:

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Abstract:

Boil water in a 20L can, seal it up, and place into a cold water reservoir. As the vapor pressure is reduced by cooling, the can collapses.

Equipment	Location	ID Number

20 L can	[:FluidMCabinetBayA1: FM, Bay A1, Shelf #2]
[:RedWhiteGasCart: Red and white gas cart	Rooms 2103, 2241, (and 2223 upon request)
Burner w/attached gas hose	[:FluidMCabinetBayB1: FM, Bay B1, Shelf #2]
Matches	[:FluidMCabinetBayA5: FM, Bay A5, Shelf #2]
Ring stand	[:FluidMCabinetBayA5: FM, Bay A5, Shelf #2]
Tub
Saftey gloves and glasses	In drawer beneath microwave in lecture demo room

Important Setup Notes:

This demonstration requires a supply of methane gas usually provided by the [:RedWhiteGasCart:red and white gas carts] found in rooms 2103, 2241, (and 2223 upon request).

Setup and Procedure:

Place the ring stand near the [:RedWhiteGasCart:red and white gas cart].
Place the tub near the stand.
Set the 20 L can on top of the stand so that the hole side is on top with the hole open.
Fill the can with about x of water. *****
Fill the tub with about 4" deep of water.
With the burner securely on the tabletop, connect the burner hose to the red panel valve on the gas cart.
Put on safety glasses.
Light the burner by opening the valve and quickly igniting the gas coming out of the burner with a match.
Place the burner directly beneath the 20 L can, and adjust the flame height accordingly by adjusting the valve.
Wait for the water to reach boiling (lots of steam will come out of the hole).
Seal the 20 L can with its cap, and quickly turn of the gas by closing the gas valve.
With the safety gloves on, move the HOT 20 L can to the tub and place it so that it's now on its side (hole pointing sideways).
Wait for the can to cool. The water vapor will recondense creating a partial vacuum in the can whereupon the can will be crushed by atmospheric pressure.

Cautions, Warnings, or Safety Concerns:

Exercise caution throughout this demo. Methane gas is extremely FLAMMABLE, and the boiling water can cause SEVERE BURNS!

Discussion:

Discuss the physics behind the demonstration, explaining some of the various steps of the demonstration when appropriate.

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Videos:

References:

[:Instructional:Home]

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