Q. Among the following, the surfactant that will form micelles in aqueous solution at the lowest molar concentration at ambient conditions, is
A) ${CH}_{3}\left( {CH}_{2} \right)_{15}N^{+}\left( {CH}_{3} \right)_{3}{Br}^{-}$
B) ${CH}_{3}\left( {CH}_{2} \right)_{11}{OSO}_{3}^{-}{Na}^{+}$
C) ${CH}_{3}\left( {CH}_{2} \right)_{6}{COO}^{-}{Na}^{+}$
D) ${CH}_{3}\left( {CH}_{2} \right)_{11}N^{+}\left( {CH}_{3} \right)_{3}{Br}^{-}$
Explanation
(a)
Sodium dodecyl sulphate (SDS)
CMC (mm)>-10
Hexadecyl trimethyl ammonium bromide (CTAB)
Note At a certain concentration surfactant molecules start to aggregate and form micelle, the concentration is called critical micellisationconcentration(CMC).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.