Q50 of 60 Page 36

What is saponification? Write the reaction involved in this process.

Soaps are made by the process of saponification. Soaps are sodium or potassium salts of long chain fatty acids. When triglycerides in fats react with aqueous NaOH or KOH, they are converted into soap and glycerol. This is called saponification or alkaline hydrolysis of esters.


CH2COOC2H5 + NaOH → CH3 COONa + C2H5OH


The soap molecule has two parts: a polar group (-COO-Na+) and a non-polar group (R-hydrocarbon part). The polar group is called the head and the non-polar group is called the tail. Therefore, the soap molecule has a polar head and a non-polar hydrocarbon tail. The polar head is water loving in nature (hydrophilic) and the non-polar tail is water repelling (hydrophobic) in nature.



The saponification reaction is exothermic in nature.


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