Fluid Phase Equilibria

Data Table and Sample Description Suggestions

Chemical Sample Description Suggestions

Data Table Suggestions


Data Table Examples

The examples are for:

  1. Thermodynamic and Transport Properties (e.g. Density, Viscosity, Speed of Sound, Heat Capacity, etc.)
    1. property = f(temperature T, pressure p, composition x)
  2. Vapor-Liquid Equilibrium (VLE)
    1. (p,T,x) data
    2. (p,T,x,y) data
  3. Liquid-Liquid Equilibrium (LLE)
    1. Tie-Line
    2. Binodal Curve
  4. Solid-Liquid Equilibrium (SLE) Data
    1. Solubility
    2. Eutectic formation
    3. Compound formation
  5. SLE-LLE overlap
  6. Multiple Phase Equilibria (isoplethic data)

NOTE 1: These are representative examples, and are not meant to cover every data type.


NOTE 2: In accord with the IUPAC Green Book (ref 1) and the GUM (Ref 2-4), the symbol for standard uncertainty is u. The symbol for the combined expanded uncertainty is Uc, where the subscript c indicates combined.

·         The relative standard uncertainty ur is also defined in the Green Book.

o   ur(x) = u(x)/|x| for x 0.

·         The symbol commonly used for speed of sound is u. The Green Book also recommends c or v for this quantity, and these should be used.


[1] IUPAC Physical and Biophysical Chemistry Division. Quantities, Units, and Symbols in Physical Chemistry, 3rd ed. (The Green Book). Prepared for publication by Cohen, E.R.; Cvitaš, T.; Frey, J.G.; Holmström, B.; Kuchitsu, K.; Marquardt, R.; Mills, I.; Pavese, F.; Quack, M.; Stohner, J.; Strauss, H.L.; Takami, M.; Thor, A.J. The Royal Society of Chemistry: Cambridge, U.K., 2007.

[2] Guide to the Expression of Uncertainty in Measurement (International Organization for Standardization, Geneva, Switzerland, 1993). This Guide was prepared by ISO Technical Advisory Group 4 (TAG 4), Working Group 3 (WG 3). ISO/TAG 4 has as its sponsors the BIPM, IEC, IFCC (International Federation of Clinical Chemistry), ISO, IUPAC (International Union of Pure and Applied Chemistry), IUPAP (International Union of Pure and Applied Physics), and OIML. Although the individual members of WG 3 were nominated by the BIPM, IEC, ISO, or OIML, the Guide is published by ISO in the name of all seven organizations.

[3] U. S. Guide to the Expression of Uncertainty in Measurement, ANSI/NCSL Z540-2-1997, ISBN 1-58464-005-7. NCSL International: Boulder, Colorado. 1997.

[4] The recommendations of the GUM have been succinctly presented in Chirico et al., J. Chem. Eng. Data 2003, 48, 1344-1359.

Last modified: 02 December 2010