Question

State the principle on which the cleansing action of soap is based. [3 MARKS]

Answer 1

Each point: 1 Mark

1. The cleansing action of soap is based on its tendency to act as a bridge between water and oil drops containing dirt particles by its amphiathic nature.
2. Dirt is attracted by hydrophobic end of soap which on rinsing moves out of clothes. They form a stable emulsion also called micelle with soap outside and dirt inside.
3. This helps in removing oil drops containing dirt particles from clothes. The clothes become clean.