G. Douheret et al., ULTRASONIC SPEEDS AND VOLUMETRIC PROPERTIES OF BINARY-MIXTURES OF WATER WITH POLY(ETHYLENE GLYCOL)S AT 298.15 K, Journal of the Chemical Society. Faraday transactions, 93(10), 1997, pp. 1943-1949
Citations number
37
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Ultrasonic speed measurements have been made by a sonic solution monit
or using a 'pulse-echo-overlap' technique, for aqueous mixtures of the
poly(ethylene glycol)s di-, tri- and tetra(ethylene glycol) at 298.15
K, across the entire composition range. Density values were taken fro
m the literature and readily converted to molar volumes, V, and excess
molar volumes, V-E. They were combined with the measured values of th
e ultrasonic speeds to furnish estimates of the isentropic molar quant
ity, K-S, equal to -(partial derivative V/partial derivative p)(S), an
d of its excess counterpart, K-S(E). The magnitude of K-S(E) decreases
with the number of oxyethylene groups, except in the water-rich regio
n. Data reduction procedures were used to calculate several related qu
antities leading to graphs with enhanced visual impact. Results were c
ompared with those reported earlier for ethane-1,2-diol-water and for
2-[2-methoxy(ethoxy)(n)]ethanol-water. Graphs of the data sets are pre
sented to furnish a basis for the discussion of evidence for the preva
iling patterns of molecular aggregation. Segmented-composition models
were employed to analyse the various excess molar quantities.