The compound formed by the reaction between an acid and a base is known as a salt. Salts like magnesium chloride, potassium nitrate, zinc carbonate and copper sulphate are useful to us in many ways.
Salts are ionic compounds which contain positively charged cations and negatively charged anions.
Salts formed from any hydroxide and:
Hydrochloric acid are called chlorides.
Sulphuric acid are called sulphates.
Nitric acid are known as nitrates.
Carbonic acid are known as carbonates.
Salts formed from:
b acids and b bases are called neutral salts.
b acids and weak bases are called acidic salts.
Weak acids and b bases are called basic salts.
Sodium chloride is obtained from the sea water by the process of evaporation. It is referred to as table salt.
Sodium chloride is used:
To preserve pickles, fish and meat.
To manufacture soap.
To melt ice formed on roads in cold countries and
As a raw material for the manufacture of other compounds.
Sodium hydrogen carbonate is used in the baking industryas an antacid, In soda acid fire extinguishers. Sodium carbonate is used to manufacture of glass, cleansing agents, soap, glass and paper, sodium compounds like borax.
Bleaching powder chemically known as calcium oxy chloride is used to bleach cotton, linen textiles and wood pulp, to disinfect drinking water,
Sodium hydroxide is produced by the electrolysis of aqueous solution of sodium chloride, called brine. The electrolysis of brine is called the ‘chlor-alkali’ process. In the process of electrolysis of brine hydrogen is collected at the cathode and chlorine at the anode.
The hydrogen formed in this process is used to manufacture fuels, margarine, and ammonia for fertilizers.
Chlorine is used for water treatment, in swimming pools, to manufacture chloro-flouro carbons, PVC, chemical compounds like chloroform, carbon tetra chloride, disinfectants, and pesticides.
Sodium hydroxide is used to manufacture soaps, detergents, paper, artificial fibres like rayon and dyes.
Some salts have a fixed number of water molecules as an essential part of their crystal. These water molecules which form the part of the crystal are called water of crystallisation and such salts are called hydrated salts.
Sodium carbonate decahydrateNa2CO3.10 H2O
Ferrous sulphate heptahydrate FeSO4.7H2O
Zinc Sulphate heptahydrate ZnSO4.7H2O
Magnesium sulphate heptahydrate or Epsom salt MgSO4.7H2O
Potash alum K2SO4 Al2 (SO4)3 .24H2O.
Plaster of paris which is chemically called calcium sulphate hemihydrate is used as a bandage, proofing material, sealing agent, for making statues, toys and decorative articles and for smoothening wall surfaces.