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Code Number: 4C30.10
Demo Title: Reduced Pressure Boiling
Condition: Good
Principle: Pressure effects on changes of state
Area of Study: Thermodynamics
Equipment:
Water, round bottom flask, ring stand with ring and wire gauze, Bunsen burner, flask stopper, masking tape, crushed ice in a baggie plastic ring.
Procedure:
Fill the flask half-way with water and bring the water to a boil on the hot plate. Remove from heat, wait for the water to stop boiling, and then put the stopper firmly into the flask. Invert and place the flask into the ring. Notice that the water is hot, but not boiling. When the baggie of crushed ice is put on top of the flask, the pressure drop causes the water to boil again. The plastic ring can be placed on top of the flask so that the ice will stay in place without sliding off.
The vacuum flask may also be used to show an interesting variation of this demo. Put ice water with large cubes of ice and not crushed ice in the flask. Connect this directly to a vacuum pump and evacuate. Observe the boiling of ice water.
References:
- Ronald D. Edge, "Hypodermic Boiling", TPT, Vol. 35, # 2, p. 110, Feb. 1997.
- Michael D. Edmiston, "Boiling, Bubbles, and Pressure", TPT, Vol. 27, # 3, Mar. 1989, p. 136.
- Thomas O, Callaway and Harry D. Downing, "Response", TPT, Vol. 27, # 3, Mar. 1989, p. 136.
- G. T. Clayton, T.O. Callaway, and H. D. Downing, "Experiments with Disposable Hypodermic Syringes", TPT, Vol. 26, # 1, p. 19, January 1988.
- Juan P. Negret, "Boiling Water and the Height of Mountains", TPT, Vol. 24, # 5, p. 290, May 1986.
- Zenon Gubanski, "Boiling Point of Water Variation with External Pressure", TPT, Vol. 7, # 4, April 1969, p. 247.
- H- 260: "Boiling at Reduced Pressure", DICK and RAE Physics Demo Notebook.
- Martin C. Sagendorf, "Boiling Water at 40 Degrees C", Physics Demonstration Apparatus, 2009. p. 107.
- George M. Hopkins, "Gases", Experimental Science, p. 97.
- David Kutliroff, "62, Boiling by Cooling", 101 Classroom Demonstrations and Experiments For Physics Teachers, p. 138.
- Vicki Cobb and Kathy Darling, "Cold Boiled", Bet You Can!, p. 66.
- Janice VanCleave, "34, Boil Water with Ice", Teaching the Fun of Physics, p. 51.
- Julien Clinton Sprott, Physics Demonstrations, "2.8, Boiling with Ice", p. 85, ISBN 0-299-21580-6.
- 13, "Boiling at Reduced Pressure", Chemical Demonstrations, Vol. 2.
- W. Bolton, "Boiling", Book I - Properties of Materials, Physics Experiments and Projects, 1968, p. 41-42.
- Borislaw Bilash II, “ Boiling Cold Water“, A Demo A Day – A Year of Physical Science Demonstrations, p. 96.