INT1 Task 3
Does Hot Water Freeze Faster Than Water at Room Temperature
By Nonya Beanez
Project Design Plan
Water has a fixed freezing point. While at the same altitude water will freeze at the same degrees Fahrenheit. According to the Mpemba effect, “As the liquid warms up, the hydrogen bonds stretch as the water gets less dense and the molecules move further apart.“ Condliffe, J. (2013, October 31). “Theories for the Mpemba effect have included: faster evaporation of hot water, therefore reducing the volume left to freeze; formation of a frost layer on cold water, insulating it; and different concentrations of solutes such as carbon dioxide, which is driven off when the water is heated.” Hot water freezes faster than cold - and now we know why. (2013, November 3)
Observing freezing times based on the liquid with various starting temperatures have been made throughout history. Aristotle, Rene Descartes, and recently Xi Xhang and his team from Mayang Technological University in Singapore have all performed experiments testing this theory. The Mphemba effect was named after a Tanzanian student who observed ice cream mixed faster when it was hot than when it was cold.
To test this theory, Nikola Bregovic placed 30 ml of room temperature water with an immersed thermistor into an empty freezer. This experiment used deionized water, the same beakers, and the same thermistor. The experimenter then tested the freezing points of various starting water temperatures. The experimenter concluded the most likely explanation was water evaporation caused the water to be less dense which is less mass to freeze. Bregovic (2013)
James Brownridge conducted a similar experiment. Brownridge froze two water samples at the same temperature and placed them in the freezer. Once frozen, he warmed one sample to room temperature and the other sample was warmed to 80 degrees Celsius and he froze both samples again. He concluded that as long as...