Question 1 What is a salt?Give example?
Question 2 Give the name and formula of any two salts.Also name the acids from which they are formed?
Question 3 What is meant by family of salts?
Question 4 Write the chemical name and formula of common salt?
Question 5 How is common salt obtained from sea water?
Question 6 What name is given to the common salt which is mined from underground deposits?
Question 7 Give few uses of common salt?
A salt is a compound formed from an acid by the replacement of the hydrogen in the acid by a metal.
For Ex :In HCl,When H is replaced by Na then we get NaCl.
In HCl,when H is replaced by NH4+, then we get NH4Cl
Salts are formed when an acid react a base.
The salt of hydrochloric acid are called chlorides.
The salt of sulphuric acid are called sulphates.
The salt of nitric acid are called nitrates.
The salt of carbonic acid are called carbonates.
The salt of acetic acid are called acetates.
Salts are mostly solids,have high melting and boiling point,solution of salt in water conduct electricity.
The salts having the same positive ions are said to belong to a family of salts.
For Ex:Sodium chloride,Sodium sulphate,Potassium salts,aluminium salts etc.
Common Salt(sodium chloride)
The chemical name of common salt is sodium chloride.
NaOH + HCl—–> NaCl + water
The sodium chloride formed here can be evaporated to obtain solid sodium chloride salt.
On a large scale sodium chloride can be obtained as:
1)Common salt from sea water:Sea water is trapped in large shallow pools and allowed to stand here.The sun’s heat evaporates the water slowly and common salt is left behind.The common salt obtained is impure and is purified.
2)Common salt from underground deposits:The large crystals of common salt found in underground deposits are called rock salt.It is mined from the underground deposit just like coal.
Uses of common salt
1)It is used as a raw material for making a large number of useful chemicals in industry such as sodium hydroxide,sodium carbonate,baking soda etc.
2)It is used in cooking food.
3)It is used as a preservative in pickles.
4)It is used in the manufacture of soaps.
5)It is used to melt ice.