What do you understand by the terms : (i) CMC, (ii) Kraft's temperat

1.	What do you understand by the terms : (i) CMC, (ii) Kraft's temperature, (iii) McBain micelle.
Answer» (i) CMC is Critical Micelle Concentration and is defined as minimum concentration above which micelle formation takes place. Below the CMC, the substance forming micelle behave as electrolyte. For example, CMC for soaps is 10^-3 - 10^-4 mol L^-1 (ii) Kraft's temperature: It is a temperature (T_k) above which micelle formation takes place. (iii) McBain micelle : The micelle generally contain at least 100 surfactant molecules. At CMC, the micelles are almost spherical, but at concentration slightly greater than CMC, micelles form flattened spheres. At still higher concentrations, they form extended parallel sheets (the thickness of sheet is about twice the diameter of one molecule). They are called Laminar micelle or McBain micelle because existence of plate like micelles of soaps was first studied by McBain (1913).

What do you understand by the terms : (i) CMC, (ii) Kraft's temperature, (iii) McBain micelle.

Answer»

(i) CMC is Critical Micelle Concentration and is defined as minimum concentration above which micelle formation takes place. Below the CMC, the substance forming micelle behave as electrolyte.

For example, CMC for soaps is 10^-3 - 10^-4 mol L^-1

(ii) Kraft's temperature: It is a temperature (T_k) above which micelle formation takes place.

(iii) McBain micelle : The micelle generally contain at least 100 surfactant molecules. At CMC, the micelles are almost spherical, but at concentration slightly greater than CMC, micelles form flattened spheres. At still higher concentrations, they form extended parallel sheets (the thickness of sheet is about twice the diameter of one molecule). They are called Laminar micelle or McBain micelle because existence of plate like micelles of soaps was first studied by McBain (1913).

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