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This week's LabZone activity
June 9, 2004
Erupting Soap
Transform an ordinary bar of Ivory soap into an erupting volcano of foam!
You will need:
- a regular size bar of Ivory soap
- a paper plate
- a microwave oven
Note: This theatrical effect does not work with ordinary soaps. Only air-filled Ivory Soap puts on a show.
Begin your experiment into the world of slow-motion explosions by unwrapping a regular size bar of Ivory soap. Place the soap on a paper plate in a microwave oven, preferably one with a glass door so that you can watch the eruption.
Nuke the soap for two minutes on full power. Your previously firm bar of soap is now a light and fluffy mound of frothy, expanded soap foam.
Insider Information
Your soap eruption is courtesy of two industrial accidents.
The first was the discovery of the heating properties of microwaves.
The second accident created Ivory soap. A machine that mixed soap was inadvertently left on during lunch. When the machine operator returned, he found that the overly mixed batch of soap had had air beaten into it. The resulting soap floated. People liked the floating soap, and the mistake turned into a marketing success.
How do two accidents equal one volcano? Ivory soap, like all soap, contains water. Microwaves cause water molecules to vibrate. When they vibrate fast enough, the water molecules turn into steam. Unlike other soaps, Ivory soap is honeycombed with thin-walled air spaces. The pressure of the steam breaks down the walls of the air spaces and a big puffball of soap grows until all the steam has escaped.
This experiment will not harm your microwave oven although it does tend to make your kitchen smell like a laundry. Speaking of laundry, your soap volcano doesn't have to go to waste. Press the puffball and ta da—Ivory flakes that you can use for washing. You have made a significant discovery in the field of good clean fun!
Reprinted with permission from You Gotta Try This! Absolutely Irresistible Science by Vicki Cobb and Kathy Darling. Text © 1999 by Vicki Cobb (www.vickicobb.com) and Kathy Darling. Published by HarperCollins.
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