Thermodynamic Properties Of Liquid Research Articles

Thermodynamic properties of liquids, including solutions

A theoretically reasonable relation between intermolecular energy, volume and temperature, previously shown to be in quantitative agreement with accurate experimental data for liquid benzene, is now applied to liquid cyclohexane. Again, quantitative agreement is obtained. A real (simple) liquid is simulated by a hypothetical liquid in which the number of contacts made by a molecule with its close neighbours, the distance between the centers of contacting molecules, and the energy of each contact are each uniform at any given temperature. Intermolecular energies between noncontacting (more distant) pairs of molecules are neglected. The dependence of volume on pressure and temperature is given by a simple equation deduced from compressibility data.

Thermodynamic properties of liquids, including solutions. XVI. Structures and thermodynamic properties of simple liquids

Abstract It is assumed that a real liquid, composed of simple molecules, behaves thermodynamically like a hypothetical liquid in which the contacts between neighboring molecules (at a given temperature) all have the same “contact energy” and the same “contact distance.” Intramolecular energies and the energies of interaction between noncontacting molecules are neglected. The molal energy is related to the contact energy, the contact distance, and the (average) contact number by an equation in which the attraction energy is of the London type and the repulsion energy is of the exponential Born-Mayer-Huggins form. The (four constant and one temperature dependent) parameters in the assumed equation have been evaluated for benzene from experimental measurements (from the literature) of the enthalpy of vaporization and the density. Using entropy data from the literature, Gibbs energies and other properties derivable therefrom can be calculated. The calculated results are for the whole liquid range of temperatu...

Thermodynamic Properties of Liquids, Including Solutions.12.Dependence of Solution Properties in Properties of the Component Molecules - Correction

Thermodynamic Properties of Liquids, Including Solutions.12.Dependence of Solution Properties in Properties of the Component Molecules - Correction

The thermodynamic properties of liquids, including solutions. XIV. Solutions of normal alkanes: Models for oligomer solutions

AbstractFrom published HE data for 10 n‐alkane solutions in benzene at 25°C, the three parameters of the author's solution theory have been calculated. The values obtained agree quite well with εΔ = 3068 J/mole, K = 1, and rσ = 0.2 + 0.2 nc = 0.1 nH. The problems involved in the extension of these results to higher oligomers of polymethylene and to other solutions of chain molecules are briefly discussed.

Thermodynamic properties of liquids, including solutions. 13. Molecular and intermolecular properties from excess enthalpies

Thermodynamic properties of liquids, including solutions. 13. Molecular and intermolecular properties from excess enthalpies

Thermodynamic properties of liquids, including solutions. 12. Dependence of solution properties on properties of the component molecules

Thermodynamic properties of liquids, including solutions. 12. Dependence of solution properties on properties of the component molecules

Thermodynamic properties derived from the free volume model of liquids

An equation of state and expressions for the isothermal compressibility, thermal expansion coefficient, heat capacity and entropy of liquids have been derived from the Free Volume Model partition function suggested by Turnbull. The simple definition of the free volume is used and it is assumed that the specific volume is directly related to the cube of the inter-molecular separation by a proportionality factor which is found to be a function of temperature and pressure as well as specific volume. When values of the proportionality factor are calculated from experimental data for real liquids, it is found to be approximately constant over ranges of temperature and pressure which correspond to the dense liquid phase. This result provides a single-parameter method for calculating dense liquid thermodynamic properties and is consistent with the fact that the Free Volume Model is designed to describe liquids near the solidification point. Calculated values ofβ, α, Cp andS for nine liquids are compared to experimental data when possible, and agree with these data within an order of magnitude.

Thermodynamic properties of liquid cadmium-bismuth-lead-tin alloys

AbstractThe partial molar thermodynamic properties of cadmium in molten Cd-Bi-Pb-Sn alloys have been determined using electrochemical concentration cells. The isothermal integral properties were calculated using the analytical method of Pelton. The value of property estimates based on interpolation of empirical series is discussed. Resume Les proprietes thermodynamiques molaires partielles du cadmium dans l'alliage liquide Cd-Bi-Pb-Sn ont ete determinees par voie electrochimique. La methode de Pelton a ete utilisee sur une isotherme pour calculer des proprietes integrales. La validite des estimes de ces proprietes est discutee en se basant sur l'interpolation des series empiriques.

Thermodynamic properties of liquids, including solutions

A new theoretical treatment of the dependence of surface pressure on the concentration of linear polymer molecules in a monolayer is presented. The development follows closely that in the author's new theory of the thermodynamic properties of three-dimensional solutions.

Thermodynamic Properties of Liquids, Including Solutions. X. Prediction of Polymer Solution Properties

A comprehensive theory of the thermodynamic properties of solutions must deal with the dependence of the Gibbs free energy, the enthalpy, and the entropy on concentration, temperature, and the chemical compositions of the components. The author’s new theoretical approach, which appears to satisfy the requirements considerably better than previous approaches, is used as a basis of a discussion of the prediction of the thermodynamic properties of solutions from parameters previously determined for other solutions, with a minimum of new data. Procedures for making predictions expected to be relatively accurate and (using a smaller amount of new experimental data) for making approximate predictions are both dealt with.

Thermodynamic Properties of Liquids, Including Solutions. IX. Thermodynamic Properties of Polymer Solutions

The writer’s new theoretical approach to polymer solution thermodynamics is outlined and the results of its application to four types of polymer solutions (rubber–benzene, polyisobutylene–benzene, polyisobutylene–cyclohexane, poly(propylene oxide)–CCl4) are presented and briefly discussed. The parameters of the theory are precisely related to the compositions, properties and interactions of the chemical units (segments) in the component molecules. The enthalpy part of the interaction parameter, χh, depends on an equilibrium between the different types of contact between segment “surfaces.” The entropy part of χ is the sum of a correction for non-randomness of distribution of the intersegment contacts and a contribution measuring the concentration dependence of the randomness of segment orientations and motions.

Thermodynamic properties of liquids, including solutions. VIII. Comparison of properties of several polymer and solvent systems

AbstractThe writer's new theory of solutions has, so far, been applied in detail to experimental data from four types of polymer solutions: rubber plus benzene, polyisobutylene plus benzene, polyisobutylene plus cyclohexane, and poly(propylene oxide) plus carbon tetrachloride. The parameters deduced for these systems are here compared and interpreted in terms of molecular and intermolecular properties. The effects of these parameters on the magnitudes and concentration dependence of the related thermodynamic properties (especially the interaction coefficient χ and its enthalpy and entropy components) are discussed and illustrated.

Thermodynamic properties of liquids, including solutions. VII. Dependence of polymer properties on molecular properties

Abstract

The thermodynamic properties of liquids, including solutions: Part 2. Polymer solutions considered as ditonic systems

The author's new theory of the thermodynamic properties of solutions is outlined. Theoretical equations are presented for applying it to polymer solutions. These equations are tested by applying them to poly(propylene oxide) + carbon tetrachloride and rubber + benzene solutions. The results are gratifying.

Thermodynamic Properties of Liquids, Including Solutions. V. Poly(propylene oxide) in Carbon Tetrachloride

Thermodynamic Properties of Liquids, Including Solutions. V. Poly(propylene oxide) in Carbon Tetrachloride

Thermodynamic properties of liquids, including solutions. IV. Entropy of mixing

Thermodynamic properties of liquids, including solutions. IV. Entropy of mixing

Thermodynamic properties of liquids, including solutions. III. Solutions of polymers, especially poly(viny chloride)

AbstractA new theory of solution thermodynamics is outlined. The energy and enthalpy are related to the contacting areas of the chemically different kinds of molecular segments, the energy per unit contact area for each kind of contact, and an equilibrium constant. Departures of the entropy of mixing from the classical Raoult's law relationship result from differences in the volumes of solvent and solute molecules, from departures from perfect randomness of mixing, and from the concentration dependence of the orientational randomness of the bonds in the molecules. Simple equations for these relationships have been tested. Quantitative agreement is usually obtained.Examples are given of applications of the theory to polymer solutions. Application to poly(vinyl chloride) solutions has not yet been made, but the appropriate procedures and methods for determining the parameters are discussed.

The thermodynamic properties of liquids, including solutions. I. Intermolecular energies in monotonic liquids and their mixtures

The thermodynamic properties of liquids, including solutions. I. Intermolecular energies in monotonic liquids and their mixtures

Ultrasonic method for determining thermodynamic properties of liquids with results for mercury

Ultrasonic method for determining thermodynamic properties of liquids with results for mercury

``Hard-Core'' Model of Liquids

Variants of the ``hard-core'' model for liquids were studied. In the hard-core model the interaction between molecules consists of a perfectly rigid repulsive core and finite, negative outer potential. Of primary concern were values of the potential energy per molecule, call it u, for the various model systems. The model systems studied were the lattice gas, hard-core models with long-range outer potentials, and hard-core models at high temperatures. For the cases studied it was found that at high density u is dominated by a term which is a function only of the density n. Furthermore, in several cases this function of density is given either approximately or exactly by —an, where a is a constant. It was noted that certain thermodynamic properties of liquids at high density and low pressure are consistent with a potential energy with a dominant term of the form —an.