Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also?



A soap molecule consists of two different ends which have different properties . One end is hydrophilic i.e. water loving and the other end is hydrophobic i.e. water fearing . The hydrophilic end dissolves in water but the hydrophobic tail end doesn't. 

When the soap is added to water, two orientations of the molecules can be seen:

  1. In the soap molecules on the surface of wate r , since the hydrophobic ‘tail’ is insoluble in water, the soap molecules align them along the water surface in such a way that the ionic end is inside water and the hydrophobic part faces outwards .
  2. But when these molecules are completely inside water , they have a very unique orientation which keeps the hydrophobic part outside water . In this type of arrangement, a cluster is formed in which the hydrophobic tails are in the interior of the structure and the hydrophilic ones are on the cluster’s surface. This formation is known as micelle .  

Since the hydrocarbon chains (water fearing) of soap are soluble in ethanol , micelle formation will not take place in ethanol .


Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Ask a doubt
Maninder Singh's photo - Co-founder, Teachoo

Made by

Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 13 years and a teacher from the past 17 years. He teaches Science, Economics, Accounting and English at Teachoo