Compilation of thermal properties of hydrogen in its various isotopic and ortho-para modifications

Abstract

New developments in science and industry are aided by accurate knowledge of the behavio r of important substances.The great abundance of chemical processes and compounds in which hydrogen is involved make it of partipular interest.The experimental a nd derived data presented here for hydrogen extend over a large range of temperature.Lo,,' temperat ures are required for the liquid and solid, and moderate and high temperatures occur in chemical reac tions.The avai lable thermal data [or H 2, HD, and D ~ in solid, liquid, and gaseous states have been brought together, includ in g the di s tinctive properties of ortho and para forms of H2 and D 2• Some data not previously publi ~h ed have been added.The thermal data include thermodynamic functions for the ideal gas state, equilibrium constants, data of s tate, viscosity, and thermal conductivity with dependence on the pressure, vapo r pressure, solid-liquid equilibria, specific heats, and latent heats.Values of state derivatives useful in t hermod ynamic calculations have been given for normal hydrogcn, and the related differences between thermodynamic functions for real and ideal gas states havc been evaluated• A temperat ure entropy diagram for normal H 2 in the range of experimen tal data is al 0 given.The compiled thermal properties of hydrogen are presented in 38 tables, 33 graphs, and numerous equations.The sources of the data have been given in an exten sive bibliography.