Flash Boiling Experiment
Idea originally suggested by Sam
Barros
Jar of soapy water flash-boiling.
Procedure:- using soap
Add a quantity of grated soap to a small amount of water in a jar.
Heat water and stir to dissolve soap.
Once soap has dissolved, water can be heated again to the point where the
soapy water boils slightly.
Quickly open the door and drop in a small object, e.g. small lid.
Soapy water will flash-boil, the boiling may be so quick that the soapy
water may hit the microwave oven's ceiling.
If flash-boiling effect isn't noticeable then the amount of soap in the
water needs to be adjusted.
Sam Barros has achieved temperatures as high as 140°C using a different
mixture and a beaker.
Be careful of the hot water, and wear necessary protective equipment.
After boiling has finished.
Variation of the experiment:- pure
water
If done properly the water can explode quite violently.
It can be difficult to achieve spectacular results. A smooth jar, glass
beaker etc. is important. Safety is very important as the hot water can
give severe burns. If dropping items in the hot liquid use long
tongs and safety glasses. For extra protection the experimenter could
wear protective clothing, e.g.. long sleeves, gloves, face shield.
Internet Links to more information
Bill Beaty's
Coffee Explosion
Dr.
Louis Bloomfield's How Things Work with superheated water videos
ABC,
Primetime Feature - Explosive Microwave Danger
ACA Story - Microwave
ovens: the hidden dangers
Exploding
Microwave-Heated Water
Superheating and microwave ovens, by Joe Wolfe
Experimental Evidence of Water Eruption Caused by Super-Heating By: C.R. Buffler* & T. Lindstrom**
© 1999 Hans
Hochwald