Thermodynamic parameters of surface formation of some aqueous salt solutions

Surface tension of aqueous solutions of inorganic salts has been measured in a laboratory investigation. Concentration and temperature dependence of the surface tension of three different salts have been studied. These include the nitrate salts of sodium, potassium and ammonium. By fitting the experimental data into linear regression surface excess concentration and thermodynamic parameters of surface formation were evaluated. The study was conducted at five different concentrations, i.e. 0.1, 0.5, 1.0, 1.5 and 2.0 mol dm−3, and five different temperatures ranging from 10 to 30 °C with the interval of 5 °C. By analyzing the results, the concentration and temperature dependence of surface excess concentration and thermodynamic parameters of surface formation such as enthalpy, entropy and surface pressure have been estimated.