Excess Thermodynamic Properties of H2O and D2O Solutions of Tetramethylurea, an Azeotropic System. Vapor Pressures, Excess Vapor Pressures, and Vapor Pressure Isotope Effects

2001 ◽  
Vol 46 (3) ◽  
pp. 777-781 ◽  
Author(s):  
Gyorgy Jakli ◽  
W. Alexander Van Hook
Keyword(s):  
Thermodynamic Properties ◽  
Vapor Pressure ◽  
Isotope Effects ◽  
Vapor Pressures ◽  
Excess Thermodynamic Properties

Thermodynamic Properties of Cyclopentanol + p-Dioxane Mixtures at 25 °C

1973 ◽  
Vol 51 (24) ◽  
pp. 4140-4144 ◽  
Author(s):  
S. C. Anand ◽  
J.-P. E. Grolier ◽  
Osamu Kiyohara ◽  
G. C. Benson
Keyword(s):  
Thermodynamic Properties ◽  
Vapor Pressure ◽  
Excess Volumes ◽  
Excess Enthalpies ◽  
Vapor Pressures ◽  
Free Energies ◽  
Excess Thermodynamic Properties

Excess enthalpies, excess volumes, and total vapor pressures were measured for cyclopentanol + p-dioxane mixtures at 25 °C. The method of Barker was used to calculate vapour–liquid equilibria and excess Gibbs free energies from the vapor pressure results. A comparison with results (from the literature) for the systems cyclohexane + cyclopentanol and cyclohexane + p-dioxane indicates that the excess thermodynamic properties of cyclopentanol + p-dioxane mixtures arise primarily from the disruption of the structure of the p-dioxane solvent.

Deuterium and hydrogen sulfides: vapor pressures, molar volumes, and thermodynamic properties

1970 ◽  
Vol 48 (5) ◽  
pp. 764-775 ◽  
Author(s):  
E. C. W. Clarke ◽  
D. N. Glew
Keyword(s):  
Stainless Steel ◽  
Hydrogen Sulfide ◽  
Thermodynamic Properties ◽  
Vapor Pressure ◽  
Sulfide Liquid ◽  
Standard Thermodynamic Function ◽  
Vapor Pressures ◽  
Molar Volumes ◽  
Enthalpy Changes ◽  
Hydrolysis Of

An apparatus is described in which deuterium and hydrogen sulfides have been prepared by the hydrolysis of aluminum sulfide. Liquid densities have been determined at −79 °C and give the molar volumes 34.811 ± 0.003 cm3 for deuterium sulfide and 34.711 ± 0.003 for hydrogen sulfide. Vapor pressures of deuterium and hydrogen sulfides have been determined at −78 °C in a quartz–metal apparatus, and in the range −30 to +30 °C in a stainless steel apparatus. Equations are derived for the deuterium and hydrogen sulfide vapor pressures and for their ratio. An isotopic vapor pressure cross-over point is found at −48 °C, above which deuterium sulfide is more volatile than hydrogen sulfide. Gas and liquid molar volumes and enthalpy changes are evaluated for liquid vaporization at saturation. The deuterium and hydrogen sulfide vaporization standard thermodynamic function changes and their errors, together with the isotopic differences for these functions and their errors, are tabulated between −80 and +50°C.

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.

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

Osmotic and activity coefficients of triorganophosphates in n-octane

1982 ◽  
Vol 60 (22) ◽  
pp. 2755-2759 ◽  
Author(s):  
Norman H. Sagert ◽  
Danny W. P. Lau
Keyword(s):  
Thermodynamic Properties ◽  
Vapor Pressure ◽  
Activity Coefficients ◽  
Osmotic Coefficients ◽  
Vapor Pressure Osmometry ◽  
Excess Enthalpies ◽  
Free Energies ◽  
Ideal Behavior ◽  
Excess Thermodynamic Properties ◽  
Complex Models

Vapor pressure osmometry was used to measure osmotic coefficients for tributylphosphate (TBP), tricresylphosphate (TCP), and triethylhexylphosphate (TEHP) in n-octane at 30, 40, 50, and 60 °C and at molalities up to 0.3 mol/kg. Activity coefficients and excess thermodynamic properties (unsymmetrical definition) were calculated from these osmotic coefficients. At 30 °C, the excess Gibbs free energies for 0.1 mol of solute in 1.0 kg n-octane were −42 J, −66 J, and −20 J for TBP, TCP, and TEHP, respectively. The more ideal behavior of the TEHP-octane system is attributed to the increasing importance of hydrocarbon–hydrocarbon interactions as the chain length is increased. The excess enthalpies for 0.1 mol of solute in 1.0 kg of solvent were −100 J, −300 J, and −150 J for TBP, TCP, and TEHP, respectively. Thus, association of these solutes arises primarily from entropie effects.Our data could generally be accommodated adequately by postulating association of monomers into dimers. The exception was TCP at lower temperatures, where more complex models were required.

Excess thermodynamic properties of isopropanol–n-decanol mixtures

1969 ◽  
Vol 47 (4) ◽  
pp. 543-546 ◽  
Author(s):  
Jaswant Singh ◽  
H. D. Pflug ◽  
G. C. Benson
Keyword(s):  
Thermodynamic Properties ◽  
Vapor Pressure ◽  
Pressure Measurements ◽  
Free Energies ◽  
Excess Thermodynamic Properties ◽  
Temperature Range ◽  
Molar Excess ◽  
Volumes Of Mixing ◽  
Vapor Pressure Measurements

Molar excess Gibbs free energies, obtained from static vapor pressure measurements on isopropanol–n-decanol mixtures over the temperature range 20–50 °C, are reported. Results of direct determinations of heats and volumes of mixing at 25 °C are also presented.

Thermodynamic Properties of Energetic Plasticizers: Experimental Vapor Pressures of Methyl-, Ethyl-, and Butyl-Nitroxyethyl Nitramines

2021 ◽  
Vol 66 (4) ◽  
pp. 1709-1716
Author(s):  
Greta Bikelytė ◽  
Martin A. C. Härtel ◽  
Marcel Holler ◽  
Andreas Neuer ◽  
Thomas M. Klapötke
Keyword(s):  
Thermodynamic Properties ◽  
Methyl Ethyl ◽  
Vapor Pressures ◽  
Energetic Plasticizers
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