Question

Explain saponification of oil/fats with equation.

Answer 1

Hint:We know that soaps are sodium or potassium salts of long chain fatty acids. The process of formation of soaps is known as saponification.

Complete answer:
The process of making soaps is known as saponification. Soaps contain sodium or potassium salts of long chain fatty acids.
During saponification, a fat or oil or lipid is heated with an inorganic base and soap and alcohol are produced.
A fat or oil or lipid reacts with sodium hydroxide \[\left( {{\text{NaOH}}} \right)\] or potassium hydroxide \[\left( {{\text{KOH}}} \right)\] which are inorganic bases. This reaction produces sodium or potassium salt of the acid and gives out alcohol as a by-product.
This reaction of fat or oil or lipid with sodium hydroxide \[\left( {{\text{NaOH}}} \right)\] or potassium hydroxide \[\left( {{\text{KOH}}} \right)\] is known as saponification.
The equation for saponification is as follows:
${\text{Oil/Fat/Lipid}} + {\text{Base}} \to {\text{Soap}} + {\text{Alcohol}}$
In saponification, free hydroxide ion breaks the ester bonds between fat or oil or lipid and produces free fat or oil or lipid. The fat or oil or lipid is soluble in water. During saponification hydration of fat or oil or lipid occurs.
Hard soaps are produced when the base used is sodium hydroxide and soft soaps are produced when the base used is potassium hydroxide. Hard soaps can be used in hard water.

Note:
The amount of sodium hydroxide or potassium hydroxide in milligrams that is required to saponify one gram of fat or oil or lipid under specific conditions is known as the saponification value or number. Higher the saponification value higher is the amount of fat or oil or lipid in the material.