PURPOSE: To show latent heat as ice is transformed to water and then to steam.
DESCRIPTION: A flask is filled to within one inch of the brim with a mixture of water and ice cubes at the freezing temperature of water. The flask is then heated for about 15 to 20 minutes with the burner on high, with the temperature measured by the dial thermometer. A plot of temperature as a function of time clearly shows that extra heat is required to produce the ice-water and water-steam phase transitions.
REFERENCES: (PIRA unavailable.) See Demonstration Reference File for paper describing this experiment.
EQUIPMENT: Hot plate, Erlenmeyer flask with cold water and ice cubes, clamp, and large dial thermometer.
SETUP TIME: 5 min.
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