How to quickly turn water into ice cubes

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

Let's open the cards right away: hot or warm water freezes faster than cool or cold water. This paradox is called the Mpemba effect. Read about why it works contrary to logic and what temperature the water should be in order for it to turn into ice faster, read our article.

Mpemba effect

This story began more than half a century ago, but has not been resolved to this day. And all because, no matter how hard thousands of inquisitive minds from all over the planet tried, they could not find the only correct solution to the Mpemba riddle.

In 1963, an obscure African student named Erasto Mpemba noticed an oddity: a warm ice cream mix solidifies faster than a chilled one.

The observation seemed so unlikely that the physics teacher could only laugh at the unlucky experimenter's discovery. However, Erasto was confident that he was right and was not afraid to become a laughingstock again: a little later, he raised a slippery issue with Denis Osborne, a professor at the University of Dar es Salaam, Tanzania. The scientist did not jump to hasty conclusions and decided to study the problem. Then in 1969 the journal Physics Education published material describing the Mpemba paradox.

In scientific circles, they immediately recalled that the greatest minds of the old times had already said something similar. For example, even Aristotle mentioned the inhabitants of the ancient Greek Pontus, who, during winter fishing, heated the water and soaked the reeds in it so that it hardened faster. Many centuries later, Francis Bacon wrote: "Slightly cool water freezes much more easily than completely cold water."

In general, the question is as old as the world, but this only fuels interest in the solution. Over the past several decades, many theories have been put forward to explain the Mpemba effect. The most likely ones were announced in 2013 at a gala event hosted by the Royal Society of Chemistry of Great Britain. The professional association studied 22,000 (!) Opinions and singled out only one of them, belonging to Nikola Bregović.

A Croatian chemist pointed out the importance of convection and supercooling of a liquid when it freezes.

This is how these phenomena are described on Wikipedia:

• Cold water begins to freeze from above, thereby slowing down the processes of heat radiation and convection, and hence the loss of heat, while hot water begins to freeze from below.
• A supercooled liquid is a liquid that has a temperature below the crystallization temperature at a given pressure. A supercooled liquid is obtained from the usual way by cooling in the absence of crystallization centers.

The worldwide recognition and the £ 1,000 check were a good reward. By the way, the winner was greeted by Erasto Mpemba and Denis Osborne.

What should be the temperature of the water before freezing

There is still no definite answer to this question. Although the Royal Society of Chemistry was determined, it did not completely stop the controversy. Until now, new hypotheses have been put forward and refutations sound.

Although there is a small clue: the popular science journal New Scientist conducted research and concluded that the best conditions for repeating the Mpemba effect are two containers of water with a temperature of 35 and 5 ° C.

Thus, if there is very little time left before the party, pour water into the ice molds, the temperature of which is comparable to room temperature in hot summer. It is best not to use well or cool tap water.