The thermochemistry of solution of sodium decylsulfate in water in the region of true solutions

The enthalpies of solution of sodium decylsulfate (DSNa) in water in the re gion of true solutions (concentration 4.5 x 10(-4) < m < 1.0 x 10(-2) mol/k g) at 290 K were measured calorimetrically. The solubility of DSNa at 290 K was determined. The Debye-Huckel theory of solutions of strong electrolyte s was used to obtain extrapolation equations for determining the standard e quilibrium constant and the thermodynamic functions of solution of DSNa fro m experimental data. The low solubility and the negative entropy of solutio n of DSNa are evidence that the process involves a strong hydrophobic effec t. The influence of this effect on changes in the structure of the solvent is discussed.