Salt

The neutral substance formed by the reaction between acidic radical and basic radical is known as salt.

Types of salt:

1. Neutral salt: The salt which is obtained after the reaction between weak base and weak acid or strong base and strong acid is called neutral salt. It does not show any change in indicators. Example: NaCl
2. Acidic salt: That salts which is produced after the reaction between strong acid and weak base is known as acidic salt. They show acidic behavior. Example: Sodium bisulphate (NaHSO₄).
3. Basic salt: Those salts which are obtained after the reaction between Sodium acetate strong base and weak acid are known as basic salt. Example: Sodium Carbonate (Na₂CO₃)

Properties of salt:

• Common salt is an essential constituent of our diet. It is salty in taste. Some other salts have bitter taste and some are tasteless.
• The salts of K, Na, Al, etc. are white in color or colorless while salts of Cu, Fe, Mn, etc are colored.

  

  Fig: Salt of potassium (K)

  

  Fig: Salt of Manganese (Mn)
• Most of the salts are soluble in water and only few are insoluble. The solution of salt can conduct electricity.
• Neutral salts are generally neutral to indicators. But acidic salts show acidic behavior and basic salts show basic behavior.

Preparation of salts

1. Direct combination of elements (metals and non-metals) Fe + S → FeS (Iron sulphide)
2. By the Action of acids on metal. Zn + H₂SO₄ → ZnSO₄ + H₂
3. By the action of acid on metallic oxides. FeO + 2HCl → FeCl2 + H₂O
4. By the neutralization of acid and base NaOH + HCl → NaCl + H₂O
5. By the action of metallic carbonates on acid CaCO₃ + 2HCl → CaCl₂+ H₂O + CO₂

Uses of salts:-

1. Sodium chloride is used as a preservative and also used in our diet.
2. Silver nitrate is used as a laboratory reagent.
3. Silver bromide is used in photography.
4. Ammonium sulphate and potassium nitrate are used as chemical fertilizers.
5. Sodium bicarbonate is used in the manufacture of baking powder.
6. Sodium carbonate is used in the manufacture ofsoap,detergents and glasses.

   

   Fig: Detergent powder used for washing clothes

   

   Fig: Glass
7. Ammonium chloride is used as a good electrolyte in thedry cell.