What is Mpemba effect
Mpemba effect is the observation that warm water freezes more quickly than cold water. The effect has been measured on many occasions with many explanations put forward. One idea is that warm containers make better thermal contact with a refrigerator and so conduct heat more efficiently. Hence the faster freezing. So the Mpemba effect is a process in which hot water can freeze faster than cold water.
Where does the Mpemba effect comes from
The Mpemba effect is named after Tanzanian schoolboy Erasto Bartholomeo Mpemba (born 1950) who discovered it in 1963. There were preceding ancient accounts of similar phenomena, but these lacked sufficient detail to attempt verification. The effect is named after Tanzanian Erasto Mpemba. He described it in 1963 in Form 3 of Magamba Secondary School, Tanganyika, when freezing ice cream mix that was hot in cookery classes and noticing that it froze before the cold mix.
Hot water freezes faster than cold, known as the Mpemba effect.
Evaporation is the strongest candidate to explain the Mpemba effect. As hot water placed in an open container begins to cool, the overall mass decreases as some of the water evaporates. With less water to freeze, the process can take less time.
This graph shows how the Mpemba effect
How hot water freezes faster than cold.
It shows how rapidly boiling water cools compared to the water that starts off
at a lower temperature. Scientists
think they have finally solved the mystery and believe the secret lies in the
unique properties of the bonds that hold water together.
