Examination of the underlying chemical physics of the Mpemba effect in water and other liquids

(1) Notre Dame College, Dhaka, Bangladesh, (2) East-West University, Dhaka, Bangladesh

https://doi.org/10.59720/22-053
Cover photo for Examination of the underlying chemical physics of the Mpemba effect in water and other liquids
Image credit: D koi

With all other conditions identical, hot liquid freezes faster than cold liquid, which might seem impossible according to Newton's law of cooling. The primary goal of this paper was to find out the reasons behind this phenomenon, known as the Mpemba effect. We hypothesized that the physical properties and hydrogen bonds of liquids could be the reason behind this phenomenon. In addition to water, four other liquids were tested in this study. Interestingly, liquids with hydrogen bonds showed the Mpemba effect. Apart from hydrogen bonds, physical properties like density, supercooling, and thermal conductivity showed their importance behind the Mpemba effect. These results demonstrated the significance of physical properties and chemical bonds behind this effect, agreeing with our hypothesis. Also, liquids like glycerol and ethanoic acid showed a strong Mpemba effect because of their initial temperature. We believe the findings we predicted in this study can help physicists create a more comprehensive model of how substances emit or absorb heat.

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