Volumetric properties of binary liquid-phase mixture of (water + glycerol) at temperatures of (278.15 to 323.15) K and pressures of (0.1 to 100) MPa

Abstract

The coefficients of compressibility, k=ΔV/Vo, of liquid binary mixture of {water (1)+glycerol (2)} were measured over the whole composition range at pressures from (0.1 to 100)MPa and temperatures from (278.15 to 323.15)K. Excess molar volumes of the mixture, VmE, partial molar volumes of the mixture components, V¯i, as well as their limiting values, molar isothermal compression KT,m, molar isobaric expansion EP,m, molar isochoric elasticity (isochoric coefficient of thermal pressure) βm were calculated. It was revealed that with glycerol molar fraction increasing the coefficients of compressibility, k, decreased to x2≈0.3÷0.4 (where x2 was glycerol molar fraction), and further changed insignificantly. It was shown that all isobars of excess molar volumes were negative and their absolute values, VmE, decreased on temperature and pressure rising. No extremes were observed on concentration dependences of partial molar volumes of glycerol in the mixture at its low concentrations. Under the state parameters studied limiting partial volumes of water and glycerol decrease with pressure rising but increase with temperature growth. Dependences of molar isothermal compression and molar isochoric elasticity on glycerol molar fraction passed extremes, and similar dependences of molar isobaric expansion had the temperature inversion regions.