CDS 2026 (I) General Knowledge, question 28

Topic: Chemistry

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Q28

Which one among the following statements regarding micelles is not correct ?

  1. (a) Soap molecules are sodium or potassium salts of long-chain carboxylic acids.
  2. (b) Micelles precipitate out of solution because of ion-ion repulsion.Correct answer
  3. (c) Grease gets collected in the centre of the micelle.
  4. (d) Soap micelles scatter light.

Solution.

Answer: (b) Micelles precipitate out of solution because of ion-ion repulsion.

  1. Ion-ion repulsion between similarly charged micelles helps keep them dispersed; it does not cause precipitation.
  2. Their hydrophobic interiors trap grease, their ionic heads face water, and the colloidal dispersion scatters light.