We’re all made to appreciate refrigeration when in the middle of a hot day we’re able to get some cold water or drink when we need it. Unfortunately, drinks are not always cold when we want them and we sometimes have to wait while a refrigerator does the work.
But did you know? You could use knowledge of thermodynamics to chill a drink in just a minute. Well, maybe a few minutes. The point is it’s very quick.
Here’s how it’s done. Get some blocks of ice in a bowl of water wide enough to hold your drink when the can or bottle is lying on its side. Don’t add the drink just yet. Add a few spoons of salt into the water and on the ice and start stirring it. Stir it thoroughly, then place the drink inside the bowl.
Here’s the catch: salt lowers the freezing and melting points of water, so a salt solution can get much colder than ordinary water. It will also require a much lower temperature to get it freezing.
With a lower freezing point, a salt solution interacting with ice and seeking to establish equilibrium would facilitate a quicker melting of the solid ice which has no salt, until the ice block and the water – with its relatively higher temperature – both degenerate into a uniform mixture with a uniform temperature.
We know that pure water at room temperature melts ice gradually and loses its warmth to cold water constantly forming out of the melting ice. In the case of salty water however, this process is quicker because salty water by its nature, inhibits the formation of strong molecular bonds in water – the process of freezing.
Next time you need that drink quicker than a refrigerator works, don’t whine too much.