The Unburnable Paper Cup

Kari Joedeman

Materials:
Bunsen Burner
Paper Cups (bottom can't have edges pointing down)
Saucepan
Water
Forceps
Thermometer

Procedures
Hold a paper cup with the forceps over the flame of the bunsen burner.
Show how readily the cup will burn. Do this near a sink or a pan of water
so that you can extinguish the fire.

Fill the cup with water. Measure the temperature of the water. Using the
forceps, hold the cup of water over the flame. You can do this until the
water begins to boil. You can then recheck the temperature. Point out to
the students that the tip of the flame is hotter than 3000 F or 1650 C.

If you fill the cup only half full, you can place it for enough into the
flame so that the top 1/2 of the cup will start to burn while the bottom 1/2
with the water in it remains intact.

Source: Kardos, Thomas, 75 Easy Chemistry Demonstrations,J. Weston Walch
Publisher, Portland, Me, 1996.
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