Contents - Index



PARAHYDROGEN provides high accuracy thermodynamic properties for parahydrogen (Molar mass =2.01594 kg/kmol) using the Fundamental Equation of State, as described by: 


Fundamental Equations of State for Parahydrogen, Normal Hydrogen, and Orthohydrogen

J. W. Leachman, R. T Jacobsen, S. G. Penoncello, and E. W. Lemmon

J. Phys. Chem. Ref. Data 38, 721 (2009)


Reference State 

    h = 4426 kJ/kg, s = 56.70 kJ/kg-K at 298.15 K, 101.325 kPa.  The reference state can be changed using the $Reference directive.


Range of applicability for equation of state:

   13.8 < T < 1000 K

 0 < P < 2000 MPa


Viscosity data are provided from:

"Measurements of the Viscosity of Parahydrogen"

Dwain E. Diller

J. Chem. Phys. 42, 2089 (1965); doi:10.1063/1.1696250

Issue Date: 15 March 1965 


Thermal conductivity is determined from: 

"Correlation of the Thermal Conductivity of Normal and Parahydrogen from the Triple Point to 1000 K and up to 100 MPa"

M.J. Assael, J.A.M. Assael, M.L. Huber, R.A. Perkins, and Y. Takata

J. Phys. Chem. Ref. Data, Vol. 40, No. 3, 2011  


Surface tension data are provided using the information in:

Mulero, A., Cachadina, I, and Parra, M.

"Recommended Correlations for the Surface Tension of Common Fluids"

J.Phys. Chem Ref. Data, Vol. 41, No.4, 2012



Fluid Property Information