The Group Contribution to the Function Derived from Density and Speed-of-Sound Measurements for Glymes in ,-Dimethylformamide + Water Mixtures.

The density and speed of sound of pentaglyme and hexaglyme in the ,-dimethylformamide + water mixture at four temperatures are presented. The limiting apparent molar volumes (VΦ,m0=Vm0), the isobaric molar thermal expansion (Ep,m0), the isentropic compressibility (κS), and the limiting partial molar isentropic compression (KS,Φ,m0 = KS,m0) were calculated. Changes in the values obtained from the physicochemical parameters, as functions of composition and temperature, were analyzed in terms of the molecular interactions and structural differentiation of the investigated systems.