HOT WATER FREEZES FASTER….BUT WHY??

Many people, when they want to cool water quickly, put it under the sun for a while and then freeze it"... But why?? Why hot water freezes faster??......

First let me tell you some interesting facts about Water.

Water may be one of the most abundant compounds on Earth, but it is also one of most mysterious one. For instance, like most liquids become denser as it cools, but unlike them, water being a unique reaches a state of maximum density at 4°C and then becomes less dense before it freezes.

Now that we know about uniqueness of water let’s get to know about this strange phenomenon.

There is the strange Mpemba effect, named after a Tanzanian student who discovered that a hot ice cream mix freezes faster than a cold mix in cookery classes in the early 1960s. Strange huh? Read on and find out the mysterious story behind it...

A single water molecule is made from a large oxygen atom connected with two hydrogen atoms.

But when a hydrogen atom in one molecule of water drifts close to an oxygen atom in another water molecule, it bonds with it, creating what is called a hydrogen bond. It is this hydrogen bond that behave in a weird way and that is the reason of this UNIQUE behavior of Water.

This effect is pretty simple: when we bring water molecules into close contact, and a natural repulsion between the molecules causes the covalent bonds to stretch and store energy. As we heat the liquid and it warms up, the hydrogen bonds stretch as the water gets less dense and the molecules move further apart.

That extra stretch in hydrogen bonds allows the covalent bonds to relax and shrink a little just like one part of the body stretches and the other automatically relaxes, giving up their energy. As the covalent bonds gives up energy, it causes cooling effect, so warm water cools faster than cold. 

This is the Mpemba effect!!! This effect explains it all why hot ice-cream mix freezes faster that the cold one.

Bhawna Mulani