14. Long answer question V

 

A soap molecule is made up of two physically distinct partsphysically same partschemically same partschemically distinct parts that interact with water in different ways. It has one polar end with a short head carboxylate group (\(-COONa\)) and one non-polar end with a long tail made of the hydrocarbonhydrocarboxylicaminoacidmonomeric chain.

 

The polar end is hydrophiliclipophilicdehydrophilichydrophobic (water-loving) in nature, and it is drawn to water.

 

The non-polar end is lipophilicdehydrophilichydrophobichydrophilic (hates water) in nature, and it is attracted to dirt or oil on the cloth but not to water.

 

As a result, the hydrophobic part of the soap molecule traps the dirt while the hydrophilic part makes the entire molecule non-degradablewater-solublebiodegradablewater-insoluble.

 

When soap or detergent is dissolved in water, the molecules form clusters known as 'molasses''biomass''wash''micelles'.

 

Their long aliphatic chainslong carboxylic chainslong hydrocarbon chainslong polymeric chains bind to the oil and dirt. As a result, the dirt is surrounded by the non-polar end of the soap molecules.

 

The micelles are water-soluble because of the charged carbonateacetateesteratecarboxylate end of the soap molecules. As a result, the soap washes away the dirt.