Acid Base & Salt - Class 10th Science
Common Salt - Sodium Chloride
The chemical name of common salt is sodium chloride. We use sodium chloride (common salt) in our food. Sodium chloride is one of the essential things of animal life. A small quantity of sodium chloride is essential for all known living creatures. Salt is responsible for regulation of water (fluid balance) in our body. In the case of dehydration, our body looses excess salt, and we fell ill. In the case of dehydration we have to rehydrate our body by taking fluid with essential salts. The sodium ion present in common salt is used for electrical signaling in the nervous system of our body. Since salt is one of the essential things for survival thus salt has been considered one of the most valuable things in human history.
Salt movement: Dandi March:
In our history to get freedom from English Salt was one of the most important symbolic weapons. Mahatma Gandhi performed Dandi March and started Salt Movement. Dandi is a place inear sea cost in Gujrat.
Obtaining of Sodium Chloride (Common salt):
In laboratory: Common salt can be obtained from reaction of sodium hydroxide and hydrochloric acid in laboratory.
From Sea water: Water from rivers flows into sea. This water carries many salts which finally remains dissolved in sea water. Common salt (sodium chloride) is separated from sea water by evaporating sea water.
From Rocks: In several parts of world solid salt are found in the form of deposit. When seas of bygone ages dried up, salt dissolved in sea water were formed in the form of beds of rock salt. From these beds salt are mined like coal.
Salts obtained from sea water or mined in the form of rock salt contain many impurities. The large crystals of salts so obtained are generally appears brown in colour because of impurities. These impurities are refined by many processes to obtain pure common salt (sodium chloride).
Some Uses of Common salt (Sodium chloride):
Manufacturing of many chemicals, such as sodium hydroxide (caustic soda), sodium bicarbonate (baking soda), sodium carbonate (washing soda), hydrochloric acid, chlorine, etc.
Common Salt (sodium chloride) is used in manufacturing of soap.
Sodium chloride is used in the flocculation (a process in which colloids come out of suspension in the form of floc or flakes by the addition of a clarifying agent).
Used as food preservative.
Common salt makes our food tasty.
Sodium chloride is used in dairy industry. Common salt is added to cheese as a color-, fermentation-, and texture-control agent.
Sodium chloride is used in textiles and dyeing industries. In these industries brine (solution of sodium chloride in water) is used to rinse separate organic contaminants.
Sodium chloride is used in wood and paper pulp industries. This is used to bleach wood pulp.
Common Salt (Sodium Chloride): A raw material for chemicals
Sodium chloride is a raw material for many chemicals which are used in our daily life. For example: Sodium hydroxide (NaOH), Sodium carbonate (Na2CO3), Baking soda, washing soda, bleaching powder, etc. are obtained from sodium chloride.