Volume 23, Issue 1, January 1994
Index of content:
Simultaneous Treatment of Vapor Pressures and Related Thermal Data Between the Triple and Normal Boiling Temperatures for n‐Alkanes C5–C2023(1994); http://dx.doi.org/10.1063/1.555942View Description Hide Description
Experimental vapor pressures, calorimetric enthalpies of vaporization and differences between the heat capacities of the ideal gas and the liquid for n‐alkanes C5 to C20 between the triple and normal boiling temperatures have been treated simultaneously. Attention was focused particularly on the region of low pressures where vapor pressure data are scarce and subject to important systematic errors. The reliability and consistency of data fro different sources was evaluated and the three parameter Cox equation was used to correlate simultaneously as a function of temperature the selected values of different properties. The recommended vapor pressures and thermal data resulting from this procedure are mutually consistent over the homologous series and present a considerable refinement particularly at lower pressures.
23(1994); http://dx.doi.org/10.1063/1.555943View Description Hide Description
A critical assessment has been made of the available experimental viscosity data for liquid n‐hexane, n‐heptane, n‐octane, n‐decane, n‐dodecane, and n‐tetradecane, with the aim of establishing standard reference values along the saturation line. Recommended viscosities are given at 298.15 K with an uncertainty conservatively estimated to be ±0.3%, except for n‐hexane and n‐heptane where it is 0.4%. Selected data which cover most of the normal liquid range are satisfactorily correlated using a modified form of Arrhenius equation. The estimated uncertainty in this correlation is ±0.5% for viscosities above 0.25 mPa s and ±1% for lower viscosities.
23(1994); http://dx.doi.org/10.1063/1.555944View Description Hide Description
Heat capacities of liquid n‐heptane, that is the recommended calorimetric reference material, have been converted to the International Temperature Scale of 1990 (ITS‐90) and new reference data have been generated. Raw experimental data measured at the National Bureau of Standards, Washington and at the Bureau of Mines, Bartlesville have been critically selected from a large compilation of liquid heat capacity data. A joint correlation of the converted data has been performed. Sets of reference data are presented for both the saturation and the isobaric heat capacities in the range fro 182.6 to 480 K. Parameters of a correlating equation and tables of heat capacities are provided.
23(1994); http://dx.doi.org/10.1063/1.555956View Description Hide Description
A thermodynamic property formulation by Jůza has been tested in detail against available experimental data. The reliability of the formulation has been determined Deviations of experimental and calculated data are generally within the limits of experimental accuracy. This article includes a survey of available experimental data and equations of state, a fundamental equation for xenon explicit in dimensionless Helmholtz energy as a function of reduced density and temperature, the values of its constants and coefficients, relations for computation of derived thermodynamic quantities, detailed comparison with experimental data, tables of thermodynamic functions calculated with the present formulation for the fluid state within the range of its validity for the single‐phase region, along the saturation curve and for the critical region.