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Title: Liquid-vapor equilibrium in binary systems for He in n-H{sub 2}, HD, and n-D{sub 2} under ordinary pressure

Journal Article · · Journal of Physical Chemistry
; ; ; ;  [1]
  1. Japan Atomic Energy Research Inst., Ibaraki-ken (Japan)

The liquid-vapor equilibrium in binary systems for He in n-H{sub 2}, HD, and n-D{sub 2} has been measured in the range 15-25 K under ordinary pressure (40-170 kPa). Helium mole fractions in the liquid phase presented linear dependence on the He partial pressure within the precision of composition measurements for all the systems: the systems obeyed Henry`s law. The Henry`s law constant K was expressed by a empirical formula by arranging the experimental data: K=F{sub 1}(T) exp(F{sub 2}(T)/RT) where R and T are the gas constant and temperature, respectively. The functions F{sub 1} and F{sub 2} were expressed by the first-order functions of temperature: F{sub 1}(T)=f{sub 1} + f{sub 2}T and F{sub 2}(T)=f{sub 3}+f{sub 4}T. The values of functions F{sub 1} and F{sub 2} and the Henry`s law constants experimentally determined agree approximately with those estimated by regular solution theory. Agreements of the calculated result using the above equation with some previous data were also demonstrated for corresponding liquid-vapor equilibrium. Enhancement factors which define deviation from Raoult`s law were experimentally determined for hydrogen isotopes. The thermodynamic equation evaluating the enhancement factors was also derived under an assumption that equations of state for the vapor phase could be expressed by virial equations using the second virial coefficients alone. The calculated values were in approximate agreement with those experimentally determined. 25 refs., 5 figs., 5 tabs.

Sponsoring Organization:
USDOE
OSTI ID:
255267
Journal Information:
Journal of Physical Chemistry, Vol. 96, Issue 5; Other Information: PBD: 5 Mar 1992
Country of Publication:
United States
Language:
English