Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid−Vapor Pressure Isotope Effects

2008 ◽  
Vol 53 (7) ◽  
pp. 1545-1556 ◽  
Author(s):  
Hui Zhao ◽  
Patamaporn Unhannanant ◽  
William Hanshaw ◽  
James S. Chickos
Keyword(s):  
Vapor Pressure ◽  
Isotope Effects ◽  
Vapor Pressures ◽  
Deuterated Hydrocarbons ◽  
Liquid Vapor

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.

Volatility of Antioxidants and Antiozonants. 1. Pure Compounds in Absence of Rubber

1964 ◽  
Vol 37 (1) ◽  
pp. 210-220 ◽  
Author(s):  
R. B. Spacht ◽  
W. S. Hollingshead ◽  
H. L. Bullard ◽  
D. C. Wills
Keyword(s):  
Vapor Pressure ◽  
Aromatic Amine ◽  
Quantitative Data ◽  
Surface Effects ◽  
Vapor Pressures ◽  
Pure Compounds ◽  
Different Temperatures ◽  
Amine Compounds

Abstract Comparable volatility data are presented for three phenolic and five aromatic amine compounds. Vapor pressure curves for the materials are given along with the vapor pressure equations derived from these curves. The equations are used to calculate temperatures at which the eight compounds would have equal vapor pressure. Vapor pressures of each material are calculated at specified temperatures. Data are given for several methods of determining actual losses of antioxidants at several different temperatures and at several different airflows. Surface effects are also studied. In general, all methods give the same relative rating of the eight materials, but quantitative data vary considerably with the method used.

Preparation of matched reagents for use with the Scholander gas analyzer

1977 ◽  
Vol 43 (1) ◽  
pp. 164-166
Author(s):  
R. G. Collins ◽  
V. W. Musasche ◽  
E. T. Howley
Keyword(s):  
Water Vapor ◽  
Vapor Pressure ◽  
Volume Change ◽  
Quantitative Method ◽  
Gas Analysis ◽  
Vapor Pressures ◽  
Gas Analyzer ◽  
Atmospheric Air ◽  
Fixed Acid

Scholander's method of gas analysis requires that the solutions for CO2 absorber, O2 absorber, and acid-rinse be matched in terms of water vapor tension throughout the analysis. Any difference in vapor pressure between either or both of the absorbing solutions and the indicator drop (composed of acid-rinse) will produce a measurable volume change which cannot be attributed to the presence of absorbable gases. This paper describes a practical and quantitative method for preparing reagents whose vapor pressures are matched. A fixed acid-rinse formulation was used throughout. A CO2 absorber prepared from 1.35 N KOH and an O2 absorber prepared from 0.76 N KOH were both matched in terms of vapor pressure with Scholander's acid-rinse solution. Analysis of atmospheric air provided a check on the accuracy of the technique. The values obtained were O2 20.94%, CO2 0.03%, and N2 (balance) 79.04%.

Influence of Nano-Refrigeration-Oil on Saturated Vapor Pressure of R22

2011 ◽  
Vol 694 ◽  
pp. 309-314 ◽  
Author(s):  
Jiang Feng Lou ◽  
Rui Xiang Wang ◽  
Min Zhang
Keyword(s):  
Experimental Data ◽  
Vapor Pressure ◽  
Mass Fraction ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Experimental Results ◽  
Vapor Pressures ◽  
Temperature Range ◽  
Mass Fractions

The saturated vapor pressures of R22 uniformly mixed with refrigeration oil and nano- refrigeration-oil were measured experimentally at a temperature range from 263 to 333K and mass fractions from 1 to 5%. The experimental results showed that the saturated vapor pressure of R22/KT56 mixture was lower than that of pure R22; the pressure deviation between them increased with a raising mass fraction of refrigeration oil and temperature. After adding nano-NiFe2O4 and nano-fullerene into KT56, the pressure deviation increased at the same mass fraction and temperature. A saturated vapor pressure correlation for R22 and refrigeration oil/nano-refrigeration-oil mixture was proposed, and the calculated values agreed with the experimental data within the deviation of ± 0.77%.

Vapor pressure isotope effects in liquid methyl fluoride

1983 ◽  
Vol 87 (16) ◽  
pp. 3153-3160 ◽  
Author(s):  
Takao Oi ◽  
Jan Shulman ◽  
Anthony Popowicz ◽  
Takanobu Ishida
Keyword(s):  
Vapor Pressure ◽  
Isotope Effects ◽  
Methyl Fluoride

PRELIMINARY STUDY OF THE FRACTIONATION OF ISOTOPIC ISOMERS BY DISTILLATION

1935 ◽  
Vol 13b (2) ◽  
pp. 114-121 ◽  
Author(s):  
D. F. Stedman
Keyword(s):  
Vapor Pressure ◽  
Boiling Point ◽  
Atomic Weight ◽  
Liquid Oxygen ◽  
Vapor Pressures ◽  
Normal Concentration ◽  
Short Run ◽  
Total Separation ◽  
Preliminary Study

Slight separations of some isotopic isomers have been achieved by equilibrium rectification. In the case of chlorine the total separation amounted to 0.048 atomic weight units; 28.6% of the O18 has also been removed from normal oxygen by the fractionation of water, and in a short run with liquid oxygen the normal concentration of O18 has been raised from 0.2% to 0.25%. The last-mentioned separation can be carried considerably further with present equipment.CH3D was synthesized. Its boiling point appears to be 0.5 °C. lower than that of methane.The vapor pressures of a 56.8% solution of D2O were measured, and it is suggested that the published values of the vapor pressure of D2O at temperatures lower than 40 °C. may be slightly too high.

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