Failures of “Meso-Phase” Hypothesis Near Vapor–Liquid Critical Point

Abstract

It is shown that the "meso-phase" hypothesis of Woodcock L. V. fails to describe quantitatively and qualitatively the isochoric and isobaric heat capacities, speed of sound, long wavelength limit of the structural factor, isothermal compressibility, density fluctuations, Joule-Thompson coefficient and isothermal throttling coefficient of argon in the "meso-phase" region. It is also shown that VdW-EOS can describe qualitatively the excess Gibbs energy and rigidity of argon near critical point.Keywords Critical point · First-order phase transition · Phase equilibrium · Argon · Heat capacity Comparison of predictions of "meso-phase" hypothesis with available data for argonThe predictions of the "meso-phase" hypothesis for the isochoric and isobaric heat capacities, speed of sound, isothermal compressibility, density fluctuations, optic (long wavelength) limit of the structural factor, Helmholtz energy, Gibbs energy, entropy, internal energy, enthalpy, Joule-Thomson coefficient and isothermal throttling coefficient of argon are obtained and discussed in Chapter 2.1. The expressions to define the above physical properties of argon using TSW-EOS [17] are given in Chapter 2.2. The comparison of the predictions of the "meso-phase" hypothesis and TSW-EOS for argon is presented and discussed in Chapter 2.3. Predictions of the "meso-phase" hypothesis for argonAccording to [26] pressure ) , ( T p M  of the "meso-phase", which exists in the density interval

Supercritical Grüneisen parameter and its universality at the Frenkel line

“…In a wider temperature and pressure range, γ in Ar in the dense gas and liquid state increases on isothermal compression and is nearly constant on isochoric heating [15]. γ was also calculated from ensemble averages of fluctuations [16]. Finally, γ was evaluated using the radial distribution function of liquids with acceptable errors [17].…”