Question

Which of the following plot correctly represents the variation of concentration of a surfactant (e.g. sodium doedecyl sulphate) versus molar conductivity with regard to behavior at CMC?

• A. a
• B. b
• C. c
• D. d

Answer 1

The correct option is A a

The molar conductivity varies as shown in plot a). With increase in concentration below CMC, molar conductivity keeps on decreasing. After CMC, the decrease becomes steeper and a discontinuity is observed at CMC.