Density and Partial Molar Volume of Cetyltrimethylammonium Bromide in the Presence and Absence of KCl and NaCl in Aqueous Media at Room Temperature

The density of cetyltrimethylammonium bromide in pure water and in the presence of KCl and NaCl at room temperature are reported. The concentrations of cetyltrimethylammonium bromide are varied from (0.013 to 0.0002) mol L -1 . Both the salts have a concentration of 0.01 M. The density of cetyltrimethylammonium bromide in presence of KCl is higher than NaCl. On the basis of the obtained results of density measurements, the critical micelle concentration (cmc), degree of dissociation (α) and partial molar volume of cetyltrimethylammonium bromide in pure water and in the presence of KCl and NaCl are determined. The obtained cmc values are also analyzed with those accounted on the basis of the surface tension data from the previous paper [1]. It is observed that the partial molar volume of surfactant increases with increase in concentration. The lesser value of partial molar volumes of cetyltrimethylammonium bromide is noticed in the presence of KCl than NaCl.