Soap is sodium or potassium salts of fatty acids (long chain). Represented as RCOO^–Na⁺. When dissolved in Water it dissociates in the RCOO^– and Na⁺. In first ion there are two parts R and COO^–. R is hydrophobic tail. and COO^– Hydrophilic head. RCOO^– ions present at the surface with COO^– group inside and R group outside. Increasing concentration to critical micelle concentration anions are pulled inside the bulk and Form a spherical shape of hydrocarbon chain pointing towards the centre and COO^– pointing outside this are called as micelle.

Cleansing action of soap- Soap molecules form micelle around oil droplets. Soaps emulsifies the oil or grease droplets. and form emulsion after washing the cloth this emulsion easily gets removed. Hence Action of soap is due to emulsification and micelle formation.