Summary: due to the presence of hydrogen bonds in water molecules, the configuration of the O-H covalent bonds changes, with the accumulation of additional energy in them, released during cooling and working as an additional heating that prevents freezing. In hot water, the hydrogen bonds are stretched, the covalent bonds are not strained, the energy storage is low-cooling and freezing is faster. There is a certain characteristic time tau required for the formation of hydrogen bonds; if the cooling process proceeds slowly, then the Mpemba effect will disappear. If the cooling process proceeds relatively quickly (up to tens of minutes), then the effect is pronounced. Probably, there must also be some critical temperature, starting from which the effect appears, but this is not reflected in the article.
Tags: physics
xially 12 march 2021, 16:58