Question

Critical micelle concentration (CMC) of soap solution lies in the range of :

• A. ${10}^{-6}-{10}^{-5}M$
• B. ${10}^{-5}-{10}^{-4}M$
• C. ${10}^{-3}-{10}^{-2}M$
• D. ${10}^{-4}-{10}^{-3}M$

Answer 1

The correct option is D ${10}^{-4}-{10}^{-3}M$

Micelles are associated colloids. These are substances which behave as a strong electrolyte at low concentration but behave as colloids at higher concentration. These particles get associated with each other and get into colloidal range called 'micelle'.
The micelle formation takes place only above a particular temperature called Kraft temperature and above a particular concentration called critical micelle concentration (CMC).
For e.g. CMC for soaps is ${10}^{-4}-{10}^{-3}M$.