Frost-Kalkwarf equation

Frost-Kalkwarf equation calculated from molecular structures, normal bp and... 

Methods Based on the Frost-Kalkwarf Equation The Frost-Kalkwarf equation relies on four compound-specific coefficients to correlate vapor pressure-temperature data ... 

R. C. Reid and T. K. Sherwood, The Properties of Gases and Liquids, 2nd ed. (New York McGraw-Hill, 1966), Chap. 4. References and a discussion of the Frost-Kalkwarf equation may be found here. Also, a rather complete comparison of various reduced equal ions is presented. These arc most useful at high pressures. 

Vapour pressure constants have also been evaluated for a modified expression of the reduced Frost-Kalkwarf equation [1395], but this type of expression is useful only where limited experimental data are available. Unfortunately, a full statistical analysis of all these alternative expansions of p(T) has not been performed. 

In deriving these equations, we have assumed that 6 is close to one and therefore In 0=0 1 and have defined AB = Bj-Bq and AC neglected the D term in the Frost-Kalkwarf equation... 

The superscript a indicates the isochore which intersects the reference fluid saturation boundary at pl = pho, ho = ZafiPcfilZcjpcj and j = (dpldT)p. The jc for the target fluid may be obtained from the Frost-Kalkwarf equation as... 

Marrucho and Ely developed a saturation boundary based method to evaluate the shape factors that is easily transferable between reference fluids. The method is based on the Frost-Kalkwarf vapour-pressure equation and the Rackett equation " for saturated-liquid densities. Using these relations and eqs 6.30 one finds for the 6 shape factor... 

Many other vapor pressure equations have been used the interested reader may refer to Partington s treatise for some of these.3 One of the most successful equations for the faithful reproduction of vapor pressures from low pressures to the critical pressure was devised by Frost and Kalkwarf.4... 

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