Solvation Studies on Sodium Dodecyl Sulphate in aqueous solutions at different temperatures

Abstract

The solution behaviour of sodium dodecyl sulphate have been investigated by measuring velocity, density and viscosity at different temperatures in the range 308°K323°K at an interval of 5°K. The interaction between ion and water molecules can be described using hydration number values for aqueous solutions of electrolyte. Adiabatic compressibility, apparent molal volume and apparent molal compressibility for the above electrolyte SDS are determined using the theoretical formulations. Using the assumption that compressibility of the solution is mainly due to the contribution of free solvent molecules, a new methodology for finding the hydration number has been developed by Kalyanasundaram et al. Based on that method, hydration number for sodium dodecyl sulphate is calculated. From the calculated values of hydration number, molar solvated volume is determined using different formulae and found to be in agreement.