Question

Why sodium chlorine s added during the preparation of soap?

Answer 1

The addition of salt (sodium chloride) to the crude form of soap forms fatty-acid salts. The sodium ions from the sodium chloride bond with the fatty acid, forming a product that is less soluble in water. Because of this reduced solubility, the soap leaves the solution and forms a solid mass.

Answer 2

Common salt is added to precipitate out all the soap from the aqueous solution. Adding of common salt to soap solution decreases the solubility of soap due to which all the soap precipitates out from the solution in the solid form. This process is called salting out of soap