Bulk properties of a liquid phase mixture {ethylene glycol plus tert-butanol} in the temperature range 278.15-348.15 K and pressures of 0.1-100 MPa. I. Experimental results, excess and partial molar volumes

The densities rho and coefficients of compressibility k = Delta V/V (0) of a binary mixture {ethylene glycol (1) + tert-butanol (2)} in the temperature range of 278.15-323.15 K and pressures of 0.1-100 MPa over the entire range of compositions of liquid phase state are measured. Found that the coefficients of compressibility k of the mixture increase both with an increase in the concentration of tert-butanol and with a rise in temperature and pressure. The excess molar volumes of the mixture, apparent, partial molar volumes, and limiting partial molar volumes of the components are calculated. It is showed that the excess molar volumes of the mixture are negative and decrease when the pressure increases. The excess molar volumes are described by the Redlich-Kister equation. The partial molar volumes of ethylene glycol sharply decrease in the range of high concentrations of tert-butanol. The dependences of partial molar volumes of ethylene glycol are characterized by the presence of a region of temperature inversion. The "negative compressibility" of the limiting partial volumes of ethylene glycol is revealed.