Isotope Effects on Internal Frequencies in the Condensed Phase Resulting from Interactions with the Hindered Translations and Rotations. The Vapor Pressures of the Isotopic Ethylenes

1963 ◽  
Vol 39 (12) ◽  
pp. 3179-3196 ◽  
Author(s):  
Marvin J. Stern ◽  
W. Alexander Van Hook ◽  
Max Wolfsberg
Keyword(s):  
Condensed Phase ◽  
Isotope Effects ◽  
Vapor Pressures

Deuterium isotope effects in condensed-phase thermochemical decomposition reactions of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine

1985 ◽  
Vol 89 (14) ◽  
pp. 3118-3126 ◽  
Author(s):  
S. A. Shackelford ◽  
M. B. Coolidge ◽  
B. B. Goshgarian ◽  
B. A. Loving ◽  
R. N. Rogers ◽  
...  
Keyword(s):  
Condensed Phase ◽  
Isotope Effects ◽  
Decomposition Reactions ◽  
Deuterium Isotope Effects ◽  
Thermochemical Decomposition

Vapor Pressure Isotope Effects in Liquidand Solid Ammonia

1989 ◽  
Vol 44 (5) ◽  
pp. 359-370 ◽  
Author(s):  
Tseng-Ven King ◽  
Takao Oi ◽  
Anthony Popowicz ◽  
Karl Heinzinger ◽  
Takanobu Ishida
Keyword(s):  
Vapor Pressure ◽  
Cell Model ◽  
Isotope Effects ◽  
Experimental Uncertainty ◽  
Vapor Pressures ◽  
Pressure Data ◽  
Vapor Pressure Data ◽  
Molecular Forces ◽  
External Forces ◽  
Solid Ammonia

The H/D and 14N/15N vapor pressure isotope effects in liquid and solid ammonia have been measured at temperatures between 163 K and 243 K. The isotopic vapor pressure data have been fitted to T ln (P′P) = A/T- B for the liquid/liquid, liquid/solid and solid/solid ranges of temperature. The triple points are; 195.41 K (45.49 torr) for 14NH3, 198.96 K (48.35 torr) for 14ND3, and 195.58 K (48.83 torr) for 15NH3. The isotopic difference in the vapor pressures of NH3 and ND3 at temperatures between 195.41 K and 198.96 K is nearly independent of temperature within the present experimental uncertainty. The phase ratios of the reduced partition function ratios, fliq/fgas and fsol/fgas, deduced from these results are well represented by Tin (fc/fg) = A/T-B. Molecular forces in the liquid and solid ammonias are discussed using a simple cell and a 4-molecular unit cell model, respectively. The librational motions in the liquid are almost as highly hindered as they are in the solid, but the directionality of the external forces on nitrogen atoms in liquid ammonia is not as well defined as in the solid.

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