Question
Action of soap is due to emulsification and micelle formation. Comment.
Solution
Answer:
The cleansing action of soap is due to emulsification and micelle formation. Soaps are sodium salts of higher fatty acids such as sodium stearate, C17H35COO–Na+, which ionises as
The anionic head of stearate ion (—COO–) is hydrophobic in nature and has great affinity for water, while the hydrocarbon part (C17H35) is hydrophobic in nature and great affinity for oil grease etc.
When soap is added to water containing dirt, the soap molecules surround to dirt particles in such a manner that their hydrophobic parts attached to the dirt molecules and the hydrophillic parts point away from the dirt molecule.
This is known as micelle formation thus we can say that the polar group dissolves in water while the non-polar group dissolves in the dirt particles.
Now these micelles are negtively charged they do not coalesce and a stable emulsion is formed.
The cleansing action of soap is due to emulsification and micelle formation. Soaps are sodium salts of higher fatty acids such as sodium stearate, C17H35COO–Na+, which ionises as
The anionic head of stearate ion (—COO–) is hydrophobic in nature and has great affinity for water, while the hydrocarbon part (C17H35) is hydrophobic in nature and great affinity for oil grease etc.
When soap is added to water containing dirt, the soap molecules surround to dirt particles in such a manner that their hydrophobic parts attached to the dirt molecules and the hydrophillic parts point away from the dirt molecule.
This is known as micelle formation thus we can say that the polar group dissolves in water while the non-polar group dissolves in the dirt particles.
Now these micelles are negtively charged they do not coalesce and a stable emulsion is formed.
