Royal Society of Chemistry Chemical Thermodynamics Volume 2: Issue 2 (Specialist Periodical Reports - Chemical Thermodynamics)

Reflecting the growing volume of published work in this field, researchers will find this book an invaluable source of information on current methods and applications. Excerpt. © Reprinted by permission. All rights reserved. Chemical Thermodynamics Volume 2 A Review of the Recent Literature By M. L. McGlashan The Royal Society of Chemistry Copyright © 1978 The Chemical Society All rights reserved. ISBN: 978-0-85186-263-7 Contents Chapter 1 The Measurement of Thermodynamic Excess Functions of Binary Liquid Mixtures By K. N. Marsh, 1, Chapter 2 Activity Coefficients at Infinite Dilution from Gas-Liquid Chromatography By T. M. Letcher, 46, Chapter 3 Experimental Methods for Studying Phase Behaviour of Mixtures at High Temperatures and Pressures By C. L. Young, 71, Chapter 4 High-pressure Phase Diagrams and Critical Properties of Fluid Mixtures By G. M. Schneider, 105, Chapter 5 Mixtures containing a Fluorocarbon By F. L. Swinton, 147, Chapter 6 Specific Interactions in Non-electrolyte Mixtures By A. G. Williamson, 174, Chapter 7 Volumetric Properties of Gaseous Mixtures By C. M. Knobler, 199, Chapter 8 Critical Exponents for Binary Fluid Mixtures By R. L. Scott, 238, Chapter 9 A Bibliography of Thermodynamic Quantities for Binary Fluid Mixtures Edited by C. P. Hicks, 275, Author Index, 539, CHAPTER 1 The Measurement of Thermodynamic Excess Functions of Binary Liquid Mixtures BY K. N. MARSH 1 Introduction This chapter deals with experimental methods for determining the thermo-dynamic excess functions of binary liquid mixtures of non-electrolytes. Most of it is concerned with techniques suitable for measurements in the temperature range 250 to 400 K and the pressure range 0 to 100 kPa. Techniques suitable for lower temperatures will be briefly reviewed. Techniques for measuring the molar excess Gibbs function GEm the molar excess enthalpy HEm and the molar excess volume VEm will be discussed. The molar excess entropy SEm can only be determined indirectly from either measurements of GEm and HEm at a specific temperature [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII], or from the temperature dependence of [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII]. The molar excess functions have been defined by McGlashan in the Introduction to Volume 1 of this series. Experimental excess functions of liquid mixtures are useful in that they provide data to test theories of liquid mixtures and provide a guide for the formulation of new theories. The data are also useful in the chemical and petroleum industries. This chapter does not contain a summary of experimental data since Chapter 9 of this volume consists of a bibliography of excess function and related measurements on binary mixtures of non-electrolytes. To date there has been no comprehensive review written on experimental techniques. Williamson's survey 2 in 1967 is now out of date as a number of new techniques have since been published. Moreover, his survey did not include a detailed analysis of the accuracy of the various techniques. The excess Gibbs function, unlike the excess enthalpy and excess volumes, cannot be measured directly. The methods from which GE can be derived include: the simultaneous measurement of the total vapour pressure p, mole fraction y in the vapour phase and mole fraction x in the liquid phase at a fixed temperature, or any two of these three, in either a recirculating still or a static vapour-pressure apparatus; gas–liquid chromatography; isopiestic measurements; light-scattering measurements; and freezing-temperature determinations combined with excess enthalpies measured over a temperature range. In 1967 Hala et al. gave a detailed review of techniques suitable for vapour–liquid equilibrium measurement but their review was confined mainly to recirculating stills. In recent years the dynamic method has been superseded by the static method for measuring isothermal vapour–liquid equilibria data. The dyn