Experimental densities, ρ, viscosities, η, speeds of sound, υ, and relative permittivities, ε
r, for three binary
mixtures of water + 2-pyrrolidinone, + 1-methyl-2-pyrrolidinone, and + 1-vinyl-2-pyrrolidinone were
measured over the entire composition range and at different temperatures. The variations of ρ, η, and υ
with water mole fractions were typical of systems which show large nonidealities. The excess molar
volumes,
, excess isentropic compressibilities,
, and deviations in dynamic viscosities, δη, and
relative permittivities, δε
r, were calculated, and their compositional variation was mathematically
represented by a Redlich−Kister type equation. The partial molar volumes of water at infinite dilution,
, were calculated from the smoothed
values of three binary mixtures at different temperatures.
The variation of the Kirkwood correlation factor, g
K, was examined across the entire composition range.
The analysis of these functions revealed that both hydrophobic and hydrophilic hydrations are responsible
for the complex nature of the thermophysical behavior in these mixtures.