ESTERIFICATION & SAPONIFICATION

ESTERIFICATION

The reaction between a carboxylic acid and an alcohol to form an ester is called Esterification reaction.

• CH₂COOH + C₂H₅OH -> CH₃COOC₂H₅ + H₂O

The product formed when a carboxylic acid reacts with an alcohol having the formula R-COO-R’ is called an ester. 

SAPONIFICATION

The reaction between the ester and hot base to give original alcohol and carboxylic acid back is called saponification reaction because this reaction is used in preparing soaps.

• CH₃COOC₂H₅ + NaOH -> CH₂COOH + C₂H₅OH 

Properties and Uses of ESTER:

• They are sweet smelling substances. 
• They are widely spread in nature. 
• The smell of fruits and flowers is due to the presence of esters. 
• They are used as flavorings agents and in making perfumes.

Cleansing action of soap 

1. The molecules of soap are sodium or potassium salts of long chain of carboxylic acids. 
2. The hydrocarbon tail being hydrophobic reacts with oil or grease. 
3. The ionic end being hydrophilic reacts with water. 
4. As a result micelles are formed. 
5. They form an emulsion in water.
6. When the surface of clothes is beaten or agitated, micelles are thrown away and the cloth is cleaned.

Micelle 

The cluster of about 100 – 200 molecules with hydrophilic ends on the surface of cluster and hydrophobic ends towards the centre, is called a micelle. 

Soaps

SOAPS VS Detergents

• Soaps are sodium salts of long chain carboxylic acids.
• Detergents are sodium salts of long chain sulphonic acids.

• Soaps do not form leather with hard water.
• Detergents form leather with hard water.

• Soaps are biodegradable.
• Detergents are non biodegradable.

• Soaps do not have strong cleansing action.
• Detergents have strong cleansing action.

• Soaps are prepared from animal fats.
• Detergents are prepared from hydrocarbons of petroleum.

Advantage of soaps over detergents :

Soaps are biodegradable so they do not produce pollution. 
While detergents being non biodegradable produce pollution.

Advantage of detergents over soaps :

Detergents can be used in hard water. Also, they have strong cleansing action. While soaps have weak cleansing action and they cannot be used in hard water.

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