Which of these is/are characteristic(s) of a soap?
I. It acts at surfaces.
II. It contains a polar ionic head.
III. Micelles of a soap are neutral and therefore react with grease effectively.

Question

Quizplus · Accepted Answer

I is correct because soap acts as a surfactant, which means it interacts with surfaces to lower the surface tension of water and allow it to spread and penetrate better. II is correct because soap contains a polar ionic head, which is hydrophilic (attracted to water) and a nonpolar tail, which is hydrophobic (repelled by water). III is incorrect because micelles of a soap are not neutral, they have a polar head which is negatively charged and a nonpolar tail which is neutral or slightly positively charged. However, micelles of soap react with grease effectively because the nonpolar tails of the soap molecules surround the grease molecules, forming a micelle, which is easier for water to wash away.

Which of These Is/are Characteristic(s) of a Soap