Abstract: | Experimental measurements of the liquid-air interfacial tension are reported for the systems benzene + n-hexane at 20°C and acetone + isooctane at 25°C. The excess surface tension for both systems is negative while the surface tension itself for the second system, when plotted against composition, exhibits a flat minimum. An attempt is made to interpret this behavior in terms of basic thermodynamic quantities of the mixtures such as the excess free enthalpy, the heat of mixing, the excess volume, and the isothermal compressibility. |