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Code Number: 4E10.20
Demo Title: Liquid Nitrogen - Balloons
Condition: Good
Principle: Properties of Liquid Nitrogen
Area of Study: Thermodynamics, Chemistry and Physics, Gas at Low Temperature
Equipment: Liquid Nitrogen, Dewars, Balloons.
Procedure:
See also: 4E10.20 in Chemistry and Physics in Everyday Experience
Arrange ahead of time to get liquid nitrogen from Biochem stores. Typically it takes about 4 liters for each classroom demonstration.
Blow up balloons and put them into the nitrogen and they will contract to a very small volume. Let them warm up on the table and they will expand to their original size.
NOTE: when the balloon is frozen in liquid nitrogen the small amount of liquid that appears in the balloon is liquid oxygen and may have a slightly bluish appearance. It may be more visible to break the balloon and pour this liquid into a wine glass. Instead of balloons you may also use air cushion packs that come as packing insulation. These are usually clear to make the liquid oxygen visible and they are fairly easy to tear to pour the liquid oxygen out.
The temperature of liquid nitrogen should be a -196 degrees C or approximately 77 degrees K.
References:
- Clyde J. Smith, "Archimedes' Principle Meets Charles' Law", TPT, Vol. 17, # 3, Mar. 1980, p. 187.
- A. J. Moreno, H. Ferrari, V. Bekeris, "Cooling Balloons with Liquid Nitrogen", AJP, Vol. 78, # 12, p. 1312, Dec. 2010.
- Hk-3: Freier and Anderson, A Demonstration Handbook for Physics.
- H-078: "Objects in Liquid Nitrogen", DICK and RAE Physics Demo Notebook.
- Imelda S. Caleon and R. Subramaniam, "Liquid Nitrogen Turns Down the Temperature on Gas-Law Demos", Physics Education, Vol. 39, # 4, July 2004, p. 324
- Brett Carroll, "Buoyancy Demonstrations with Helium Balloons", PIRA Newsletter, Vol. 1, # 5, p. 5, Sept. 1986.
- Gordon McComb, Lasers, Ray Guns, & Light Cannons - Projects from the Wizard's Workbench, pp. 28.
- Borislaw Bilash II, “Charles' Law“, A Demo A Day – A Year of Physical Science Demonstrations, p. 90.