Action of soap is due to emulsification and micelle formation. Comment.
Soap molecules have two parts, on is polar head which is hydrophilic (water soluble) carboxylate group and other is non polar tail, which is hydrophobic (oil soluble) hydrocarbon tail. In water, several soap molecules aggregate to form micelles in which hydrocarbon tails are in the interior of cluster and polar heads are at the surface of clusters. The dirt in cloth is due to presence of dust particles in fat or grease which stick to the cloth. In the soap solution, micelles are formed around oil droplets. The hydrophobic part of soap is in the oil droplet and hydrophilic part projects outside like bristiles. The oil drops and micelle are then pulled in water due to hand rubbing or agitation and are washed away.
