Attempt to Account Quantitatively for the Variation of Specific Conductivity of Cetyltrimethylammoniumbromide and Cetylpyridiniumbromide with Dilution On Colloidal Electrolytes.

Department of Chemistry, Calcutta University, Calcutta-9 Received 15 December 1971 It has been shown that the variation of specific conductivity, Xc, over a wide range of stoichiometric concentration, C, of the solutions of Cetylpyridinium bromide and Cetyl­trimethyl ammonium bromide can be accounted for by the following equation Xc—Xc = Xm\((C-C_o) \over K+ (C-C_o)\)[1+\(\beta\)(C-Cd)] where Co represents the c.m.c., Xo the corresponding specific conductivity, Xm, K, and \(\beta\) and constants and Cd the stoichiometric concentration at which the diffuse electrical double layers of the micelles begin to overlap. It has also been shown that the specific surface conductance, \(\chi\), of the micelles can be found if Xm and the radius, r, is known. In the case of (CPB) the value of x has been found to be 1.56 x 10-9