Volumetric properties of the water-ethylene glycol mixtures in the temperature range 278–333.15 K at atmospheric pressure

Abstract

Density of the water-ethylene glycol binary mixtures was measured in the entire range of compositions in the temperature range 278–333.15 K (6 values) at atmospheric pressure using a vibration densimeter. Mixtures with low concentrations of ethylene glycol were studied at 15 temperatures in the range of 274–333.15 K. Excess molar volumes V , the partial molar volumes of water -V 1 and ethylene glycol, -V 2, the coefficients of thermal volume expansion α of the mixture, the partial molar volume coefficients of thermal expansion of water $$ \bar V_1 $$ and ethylene $$ \bar V_2 $$ were calculated. Excess molar volumes were described using the Redlich-Kister equation. The density ρ of the mixture was found to increase with the increasing ethylene glycol concentration at all temperatures, but at low content of ethylene glycol the dependence ρ = f(T) of the mixture at ∼276.5 K passed through a maximum. The coefficient α increases sharply in the composition range 0 < x < 0.2, in the range 0.5 < x <1 remains almost unchanged, and at T > 277 K is positive for all compositions. The dependences $$ \bar \alpha _1 $$ = f (x) and $$ \bar \alpha _2 $$ = f (x) are complex in whole temperature range and are characterized by the presence of an extremum. V values are negative at all temperatures, and upon increase in the temperature the deviation from ideality decreases (x is the mole fraction of ethylene glycol).