Water freezes at a temperature, equal 0 degrees Celsius. Let's assume, ice urgently was necessary for you for some purposes. How to receive it? It would seem, as easy as shelling pears: it is necessary to pomesit only a vessel with liquid in the freezer. But water, because of very big specific heat, cools down slowly, and formation of ice can take a lot of time.
Instruction
1. Speed of freezing of water depends, first, on heat exchange surface area, and secondly, on thickness of a water layer: than it is more, that all volume of water will freeze more slowly (and vice versa). Therefore pour water in such tanks that the surface of cooling was rather big, and thickness of a water layer – small. It is possible to use, for example, lednitsa - plastic substrates with small and superficial tanks which release especially for this purpose – receiving food ice in house conditions. Place such container with water in the deep freeze. Ice is formed much quicker than in case just the same amount of water is poured in a plastic cup, for example.
2. Besides, it is possible to accelerate water freezing as follows. When its temperature is already close to 0, throw into each capacity one - two grains of table salt. It would seem, a paradox, it is known that salty water freezes at lower temperature, than fresh. But this paradox only seeming: the mass of salt will be so insignificant that water actually will remain fresh, and grains will serve as peculiar initiators of crystallization.
3. If you have a long thin capacity of type of a test tube (only metal), it is possible to receive very quickly ice by means of liquid nitrogen. Lower this container with water (by means of a long clip or a wire) in a vessel of the Dewar, certainly, not completely that liquid nitrogen did not fill in it. After a while get. As soon as walls of capacity heat up, ice easily can be extracted.
4. It is possible to use property of some chemicals to be dissolved for fast freezing of water, absorbing a large amount of heat. For example, there is such substance – ammonium nitrate (ammonium nitrate). It is widely used in agriculture as nitrogen fertilizer. If ice which you want to receive is used not in the food purposes, add ammonium nitrate directly to capacity with chilled water and dissolve, mixing. Then put capacity in the deep freeze again. Ice is formed in only a few minutes.