Speeds of sound and isentropic compressibilities for binary mixtures of 1,2-ethanediol with 1-butanol, 1-hexanol, or 1-octanol in the temperature range from 293.15 to 313.15 K

Abstract

Speeds of sound for binary mixtures of 1,2-ethanediol with 1-butanol, 1-hexanol, or 1-octanol were measured by means of pulse-echo-overlap method over the entire composition range and at temperatures ranging from 293.15 to 313.15K. From the measurement values and literature data on density, the excess molar isentropic compressibility was calculated and approximated by the Redlich–Kister polynomials. In two cases (mixtures with 1-butanol or 1-hexanol) the negative values of the excess molar compressibilities over the whole composition and temperature range are observed. In the third case (mixtures with 1-octanol) the s-shaped dependence is observed. The rigidity in mixtures under test increases from 1-octanol to 1-butanol. The excesses were discussed in terms of molecular interactions. The experimental data were used also for the calculation of the speeds of sound deviations. The ratios between excess and ideal values were calculated and discussed as well.