Comparative Studies of the Mixing Effect on the Thermal Effusivity, Compressibility, and Molar Volume for Aqueous Solutions of Alcohols

Concentration dependences of the thermal effusivity, isentropic compressibility coefficient, and molar volume were investigated experimentally for aqueous solutions of ethanol, 1-propanol, and 2-propanol. The thermal effusivity was determined using a photoacoustic method. The excess molar volume was found from measured densities, while the isentropic compressibility coefficient was calculated based on density and ultrasound velocity measurements. It has been shown that the dependence of the effusivity on concentration, expressed in mass fraction units, is nonlinear in the case of all the alcohols used. Moreover, the location of extreme deviations from linearity for the thermal effusivity, Δe, agrees well with that of characteristic points for the isentropic compressibility coefficient, κ S , and the excess molar volume, \({V_{\rm m}^{\rm E}}\), as a function of the concentration.