Question

(ii) Explain the cleansing action of soap.

Hint:

Soap molecules have both hydrophilic and hydrophobic parts, which enable them to break down grease and oil, making them easy to wash away with water.

Answer 1

The cleansing action of soap is due to its amphiphilic nature, meaning it has both hydrophilic (water-attracting) and hydrophobic (water-repelling) ends. When soap is mixed with water, the hydrophilic part of the soap molecule is attracted to water, while the hydrophobic tail is repelled by water but attracted to grease or oil.
- The soap molecules surround grease particles and form structures called micelles. The hydrophobic tails of soap molecules trap the grease in the center, while the hydrophilic heads face outward, allowing the micelles to be suspended in water.
- This makes it easier for the grease to be washed away from the surface.
Thus, soap helps in removing dirt and oil from surfaces by breaking down grease and allowing it to be washed away by water.