Explain the mechanism of the cleaning action of soaps.

AcademicChemistryNCERTClass 10

The cleansing action of Soap: When a dirty cloth having oily spot is put in water containing dissolved soap, the oil is not dissolved in water. The soap molecules are salts of sodium and potassium of long-chain carboxylic acid. The acid end of soap is hydrophilic i.e. water-loving and gets dissolved in water and the carbon chain dissolves in oil. Soap molecules form the structure of a micelle in which one end of the soap molecule is attached to the oil droplet and the other end towards the water. The formation of soap micelles thus removes oil particles from the surface and the surface is cleaned.

[Extra information: Scum is formed when soap is used in hard water because a large amount of soap reacts with the magnesium and calcium ions of hard water producing an insoluble curdy precipitate that sticks to the clothes making them difficult to be cleaned.]

Updated on 10-Oct-2022 12:47:20