Does hot water freeze faster than cold water?

Checking whether hot water freezes faster than cold water or doesn't sound silly. In general, the water is frozen into ice at 0 degrees Celsius. But is it hot enough to kill E. coli (about 120 degrees F or 50 degrees C) that freezes into ice faster than cold water (about 60 degrees F or 15 degrees C)? Although there are logical arguments, in fact hot water can freeze faster than cold water under certain conditions.

This remarkable natural feature known as the 'Mpemba effect' is named after the high school student Erasto Mpemba of Tanzania for being the first to observe the phenomenon in 1963. The Mpemba effect occurs when two blocks of water At different temperatures, the same temperature is exposed to the same temperature, at which time the hotter mass will freeze first. Mpemba's observations confirmed the hunch of some of the most respected thinkers in history such as Aristotle, Rene Descartes and Francis Bacon. They are also people who think that hot water froze faster than cold water.

The evaporation process is the factor that helps explain the Mpemba effect most effectively. When hot water is placed in a closed container, it begins to cool. The overall volume will decrease because of evaporation. Because there is little water left to freeze, the freezing process takes less time. But this is not always the case, especially when hot water containers have a lid. Then evaporation water will be prevented from escaping.

Hot water can freeze faster than cold water under certain conditions.(Photo: sarahmeyerwalsh.files.wordpress)

The evaporation process is not the only reason for hot water to freeze faster. In hotter water, there is less dissolved gas, which reduces the ability to conduct heat to help it cool faster. However, Polish physicists in the 1980s could not prove this connection convincingly.

The uneven distribution of heat in the country can also explain the Mpemba effect. Hot water will rise to the top of the container before evaporating, changing the cold water layer to create a hot surface. The rising activity of hot water and the sinking of cold water is called convection. A convection current is a common form of heat transfer in liquids and gases, which occurs in oceans or heaters that warm a room. When the colder layer is located at the bottom of the container, this uneven temperature distribution will create convection currents that accelerate the cooling process. So hotter water will lower the temperature faster than cooler water.

So the next time you have to pour water into the ice tray, you often use hot water. Then you will have ice to drink faster.