Soaps are prepared by treating the esters of fatty acid with alkali. Sometimes common salt is also added to it. Why is common salt added during this process?
In the reaction of esters with alkali to prepare soap (saponification reaction), the product (soap) is obtained in a suspension form. To precipitate the soap out of the suspension form, common salt (NaCl) is added to it. This process is often referred to as “salting out” of soap.