Please explain cleansing  action of soap and detergents

Asked by Kanwaranita10 | 12th May, 2018, 08:00: AM

Expert Answer:

  • Soaps are cleansing agents capable of reacting with water and dislodging the unwanted particles from clothes or skin.
  • The molecules of soap are sodium or potassium salts of long chain carboxylic acids.
  • A soap molecule has a tadpole shaped structure.
  • At one end (long non-polar end) of soap molecule is a hydrocarbon chain which is insoluble in water but soluble in oil.
  • At the other end (short polar end) of soap molecule, there is a carboxylate ion which is hydrophilic i.e. water soluble but insoluble in oil.




  • Soap on mixing with water forms a concentrated solution and causes foaming.
  • The long non-polar end of soap gravitates towards and surrounds the dirt and absorbs the dust in it.
  • The short polar end with the carboxylate ion repels the water away from the dirt.
  • A spherical aggregate of soap molecules is formed in the soap solution in water, and is called a micelle.
  • Thus, the soap molecule dissolves the dirt and our clothes get clean.


Answered by Ramandeep | 14th May, 2018, 10:07: AM