The speed of sound u and density ρ for the binary mixture hexane + hexadecane has been measured as a function of composition and temperature along the saturation line between 293.15 K and 373.15 K. The speed of sound was measured by a pulse-phase echo ultrasonic device at a frequency of (1 to 5) MHz with an uncertainty of ±0.1%. The density was measured by an Ostwald−Sprengel-type pycnometer with an uncertainty of ±3 × 10-5 g·cm-3. The experimental results were used to calculate deviations of the speed of sound Δ u, excess molar volume V E, and isentropic compressibility k S . The values Δ u and V E were fitted by the Redlich−Kister equation.

This review deals with the investigation of the ultrasonic velocity in organic liquids on the saturation curve and with analysis of the results obtained at the Kursk State University -KGU (before that, Kursk State Pedagogical Institute -KGPI) during the period from 1969 to the present day. Much attention is given to the description of the procedure of measurement of the sound velocity by the pulse-phase method developed at the Laboratory of Molecular Acoustics of the KGU and to the estimation of measurement errors. The data on the sound velocity along the saturation curve in a wide temperature range for three classes of organic liquids (saturated hydrocarbons, aliphatic alcohols, and aromatic hydrocarbons) are given in the form of tables. Characteristic features of the behavior of the sound velocity and adiabatic compressibility of liquid in the vicinity of the critical point are investigated, and the possibility of using the acoustic data for the calculation of the thermodynamic properties of liquids is studied.

The speed of sound u, density ρ, and specific heat capacity at constant pressure C P for liquid 1-chlorohexane, 1-iodohexane, 1-iodoheptane, and 1-chlorononane were measured as a function of temperature along the saturation line between (293.15 and 373.15) K. The experimental results were used to calculate various thermophysical properties such as the isobaric thermal expansion coefficient α P , the isentropic compressibility k S , the isothermal compressibility k T , the specific heat capacity at constant volume C V , the ratio of C P to C V , the temperature coefficient of pressure at constant volume (∂P/∂T) V , and the internal pressure P i.

Experimental speeds of sound and densities are presented for the liquid phase of 1-iodohexane. The measurements were carried out along nine isotherms from (293.15 to 413.15) K at pressures from the saturation condition up to 200 MPa. The speed of sound was measured by a pulse-phase echo ultrasonic device at a frequency of (1 to 5) MHz with an uncertainty of ±0.2%. The density was measured by an acoustic piezometer with an uncertainty of ±0.3%. The experimental results have been used to calculate the isentropic compressibility, κ S .

The density and viscosity values of binary mixtures of hexane with 1-chlorohexane have been measured as a function of composition and temperatures between 293.15 K and 333.15 K. The estimated uncertainties are less than ±1 × 10-4 g·cm-3 for density and ±0.5% for viscosity. Viscosity deviations Δη were fitted by the Redlich−Kister equation.