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  • 1/11/2009

Common or Table Salt

salt

Common or table salt is one of the most useful substances in the world. Everyone needs tiny quantities of salt in their food to keep them healthy. This is because salt forms part of your blood, sweat, and tears. Apart from being used in cooking, it is still used to preserve food and to make many other chemicals. It is also used in making dyes, paper, pottery, leather, and many medicines. Large quantities of salt are put on roads and pavements in winter to keep them free from ice and snow.

 

Making salt

It is possible to make common salt by mixing hydrochloric acid with the alkali caustic soda. These chemicals are both very dangerous. But when they are mixed they neutralize each other to form a harmless salt, called sodium chloride. We call this common or table salt. There is no need to make table salt using this kind of chemical change, however. There is plenty of this salt in the sea and, in places, under ground.

 

Table salt from the sea

To get salt from the sea in hot countries, people let sea water into shallow ponds near the shore. Then the sun’s heat make the water evaporate, leaving the salt behind.

Mining salt

The salt which is found under the ground was left there millions of years ago when ancient seas dried up. The salt is obtained by drilling, or digging mines. In some countries, there are salt mines where people and machines dig for it underground. Most underground salt is obtained by using a physical change, however. Water or steam is pumped down pipes into the salt. The salt dissolves in the water and the salt solution is pumped to the surface. There the solution is heated so that the water evaporates, leaving the salt behind.


Other links:

Eating well, Even while Eating out

Carrots: Nutritional Heroes

Eat More Cereal

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