Statistical Mechanics of Deuterium Exchange Reactions: Recalculation of Thermodynamic Properties of Water-Methanol Reactions

1979 ◽  
Vol 32 (3) ◽  
pp. 465 ◽  
Author(s):  
JR Khurma ◽  
DV Fenby
Keyword(s):  
Liquid Phase ◽  
Thermodynamic Properties ◽  
Force Field ◽  
Gas Phase ◽  
Vapour Pressure ◽  
The Other ◽  
Exchange Reactions ◽  
Statistical Mechanical ◽  
Experimental Values ◽  
Methanol Reactions

Thermodynamic properties of the reactions CH3OH+HDO → CH3D+H2O CH3OH+D2O → CH3OD+HDO in the gas phase are calculated from statistical mechanical equations. Two sets of calculated harmonic frequencies are used: one obtained from an experimental force field and the other from an ab initio force field. Thermodynamic properties of the corresponding liquid-phase reactions are obtained by combining the gas-phase values with vapour-pressure isotope effect results. The calculated properties are compared with published experimental values.

Thermodynamics of Deuterium Exchange Reactions in Water-Thiol and Alcohol-Thiol Systems

1979 ◽  
Vol 32 (4) ◽  
pp. 755 ◽  
Author(s):  
JR Khurma ◽  
DV Fenby
Keyword(s):  
Thermodynamic Properties ◽  
Gas Phase ◽  
Equilibrium Constants ◽  
Deuterium Exchange ◽  
Excess Enthalpies ◽  
Exchange Reactions ◽  
Gas Phase Reactions ◽  
Molar Excess ◽  
Harmonic Frequencies ◽  
Statistical Mechanical

Thermodynamic properties at 298 K are obtained for the deuterium exchange reactions RSH + SHD → O + RSD + H2O RSH + DO2 → O + RSD + HDO RSH + R?OD → O + RSD + R?OH Equilibrium constants and enthalpies of the gas phase reactions with R = R' = CH3 are calculated from statistical mechanical equations using recently published harmonic frequencies. Experimental properties, including the molar excess enthalpies of C2H5SH + CH3OH, C2H5SH + CH3OD, C2H5SH + C2H5OH and C2H5SH + C2H5OD reported in this paper, are used to obtain the equilibrium constants and enthalpies of the liquid and gas phase reactions with R = C2H5, R' = CH3 and C2H5.

Deuterium exchange in water-methanol systems: Calculation of equilibrium constants

1977 ◽  
Vol 30 (11) ◽  
pp. 2371 ◽  
Author(s):  
DV Fenby
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Isotope Effects ◽  
Equilibrium Constants ◽  
Deuterium Exchange ◽  
Exchange Reactions ◽  
Infrared Studies ◽  
Experimental Values ◽  
Calculated Equilibrium ◽  
Water Alcohol

Equilibrium constants for a number of water-alcohol deuterium exchange reactions in the gas phase are calculated from harmonic frequencies of CH3OH, CH3OD, CD3OH and CD3OD obtained from recent infrared studies. These are combined with vapour-pressure isotope effects to give equilibrium constants for the same reactions in the liquid phase. Calculated equilibrium constants agree well with most published experimental values.

Perfluormethyl-Element-Liganden, XI Die Schwingungsspektren von (CF3)2EMn(CO)5 (E=P, As) / Perfluoromethyl Element Ligands, XI. Vibrational Spectra of (CF3)2EMn(CO)5 (E = P, As)

1975 ◽  
Vol 30 (7-8) ◽  
pp. 539-543 ◽  
Author(s):  
Reinhard Demuth ◽  
Joseph Grobe ◽  
Robert Rau
Keyword(s):  
Liquid Phase ◽  
Force Field ◽  
Gas Phase ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
Ir And Raman Spectra ◽  
Normal Coordinate ◽  
Ir And Raman

The gas phase IR and liquid phase IR and Raman spectra of (CF3)2PMn(CO)5 and (CF3)2AsMn(CO)6 have been recorded. The spectra are assigned on the basis of a normal coordinate analysis using a transferred force field.

Thermodynamics of deuterium exchange reactions in water-amine and alcohol-amine systems

1981 ◽  
Vol 34 (9) ◽  
pp. 1801
Author(s):  
ZS Kooner ◽  
DV Fenby
Keyword(s):  
Thermodynamic Properties ◽  
Equilibrium Constant ◽  
Deuterium Exchange ◽  
Excess Enthalpies ◽  
Exchange Reactions ◽  
Molar Excess ◽  
Harmonic Frequencies ◽  
Statistical Mechanical

Vapour pressures and molar excess enthalpies at 298.15 K are reported for the systems H2O+(C2H5)2NH and D2O+(C2H5)2NH. They are analysed to give the equilibrium constant and enthalpy of the reaction ����������������� 2(C2H5)2NH(1)+D2O(1)→2(C2H5)2ND(1)+H2O(1) Molar excess enthalpies at 298.15 K of the systems CH3OH+(C2H5)2NH, CH3OD+(C2H5)2NH, C2H5OH+(C2H5)2NH and C2H5OD+(C2H5)2NH are used to obtain enthalpies of the reactions ���������� (C2H5)2NH(1)+ROD(1)→(C2H5)2ND(1)+ROH(1)� (R = CH3, C2H5)Thermodynamic properties of various NH/OD exchange reactions are calculated from statistical mechanical equations by use of harmonic frequencies.

Borierungsreaktionen an den N-Oxiden und -Iminen ungesättigter Stickstoffbasen / Boration Reactions with the N-Oxides and m-Imines of Unsaturated Nitrogen Bases

1980 ◽  
Vol 35 (5) ◽  
pp. 568-577 ◽  
Author(s):  
Peter Paetzold ◽  
Günther Schimmel
Keyword(s):  
Nitrous Oxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
The Other ◽  
Double Bonds ◽  
Similar Reduction ◽  
Nitrogen Bases ◽  
Other Hand

1,3-Dipolar reagents with an unsaturated CNO- or CNN-skeleton undergo 1,3-organoboration by triorganoboranes. On the other hand, the unsaturated NNO-skeletons in azoxybenzene or nitrous-oxide are reduced to the corresponding NN-fragment by trialkylboranes. The 1,3-addition of aminoborane Cl2BNMe2 to the aldimineoxide PhHC = NMe-0 represents one of the rare examples of analogous reactivity of BN- and CC-double bonds. O-Borylhydroxylamines PhHCR-NMe-OBR2 are reduced by BR′3 to PhHCR-NMe-BR′2 and R′0-BR2. Similar reduction products are isolated from liquid-phase thermolysis of PhHCEt-NMe-OBEt2 (16), whereas gas-phase thermolysis of 16 gives PhCH = NMe, (EtBO)3, and C4H10.

Mass-spectrometric studies of ionization in flames I. The spectrometer and its application to ionization in hydrogen flames

1960 ◽  
Vol 255 (1283) ◽  
pp. 520-537 ◽  
Keyword(s):  
Nitric Oxide ◽  
Gas Phase ◽  
Reaction Zone ◽  
Heat Of Formation ◽  
The Other ◽  
Exchange Reactions ◽  
Thermal Phenomenon ◽  
Secondary Phenomenon ◽  
Kinetics Of ◽  
Positive Ion

An apparatus is described for the extraction of ions from flames burning at atmospheric pres­sure, and for the subsequent mass analysis of the ions. It consists essentially of a fine leak in a platinum or quartz diaphragm on which the flame is played, and on the other side of which a low pressure is maintained by pumping. The ions are separated by suitable disposition of electrodes in a series of expansion chambers before passing into the analyzer. It is concluded that secondary ionization is not important in the mass spectrometer, and that charge exchange reactions and other related types of reaction, in so far as they occur inside the spectrometer, largely reflect similar reactions occurring in the external flame. Ionic concentrations as low as 10 5 per cm 3 can be measured for ions ranging in mass from 10 to 400 atomic units. A brief account is given of the ionization observed from premixed flames of hydrogen, oxygen and nitrogen. The most evident positive ion was hydroxonium (H 3 O + ), the other important ones being NH + 4 and NO + . The first two of these also occurred in hydrated forms, associated with up to 4 molecules of water. These hydrates occur to a large extent in the cooler parts of the flame system (just before the reaction zone), and are considered to be a secondary phenomenon, possibly formed by association just inside the entry leak into the spectrometer. Experimental evidence is adduced for the formation of H 3 O + in the homogeneous gas phase in and near the reaction zone, rather than by catalytic interaction with the walls of the leak. The most likely reaction is considered to be H + H + OH = H 3 O + + e - and the kinetics of this are considered. Doubts about the heat of formation of this ion, and about that of the NH + 4 ion preclude quantitative decisions on many points. The ionization of nitric oxide is shown to be essentially a thermal phenomenon, by observations of ionization with known amounts of nitric oxide added to the flame gases. The relatively slow rate of recombination observed beyond the reaction zone is discussed, and found to be in line with previous results.

scholarly journals On the vapour-pressure and osmotic pressure of a volatile solute

1908 ◽  
Vol 81 (548) ◽  
pp. 336-336 ◽  
Keyword(s):  
Liquid Phase ◽  
Hydrostatic Pressure ◽  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Specific Volume ◽  
Vapour Phase ◽  
The Other ◽  
Other Hand ◽  
Specific Volumes

It follows by a method given in a recent paper by the author that if the osmotic membrane be assumed to be impermeable to the solute, the formula for the change of vapour-pressure of a volatile solute with hydrostatic pressure, and also the formula for the osmotic pressure which is deduced from it, must be the same as the formula for a non-volatile solute, and should not contain any terms depending on the vapour-pressure of the solute, except in so far as it may affect the hydrostatic pressure of the solution. If, on the other hand, an osmotic membrane is regarded as a vapour-sieve permeable to the vapour of the solution but not to the liquid phase, the equation takes a different form, depending on the concentration of the constituents in the vapour-phase. If c 1 , c 2 , etc., be the concentrations of the constituents in grammes per gramme of the vapour, and if U 1 , U 2 , etc., be the specific volumes of the constituents in the solution, the change of total vapour-pressure dp of the solution for a change of hydrostatic pressure d P is given by the relation, ∑ c U d P = v dp , where v is the specific volume of the whole vapour-phase. If only on constituent is volatile, this relation reduces to the form U d P = v dp for that constituent.

scholarly journals Vapour-liquid phase equilibria and thermodynamic properties of solutions of the ethylbenzene and n-alkylbenzenes binary systems

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Yuri K. Suntsov ◽  
Nina S. Suntsova
Keyword(s):  
Liquid Phase ◽  
Thermodynamic Properties ◽  
Vapour Pressure ◽  
Homologous Series ◽  
Binary Systems ◽  
Molar Mass ◽  
Helmholtz Energy ◽  
Binary Solutions ◽  
Saturated Vapour Pressure ◽  
Saturated Vapour

The methods of theoretical description of the patterns of changes in thermodynamic properties depending on the composition and structure of solution components are a priority direction in the development of the theory of solutions. This article is devoted to the establishment of relationships between the thermodynamic properties, composition of solutions, and the structure of their components. The study of the thermodynamic properties of binary solutions formed by a common solvent (ethylbenzene) and substances of the homologous series of n-alkylbenzenes contributes to the establishment of the aforementioned relationships. In the production of ethylbenzene and its homologues, solutions based on n-alkylbenzenes are quite common. Alkylbenzenes are widely used in various fields of science and chemical technology as solvents, extractants, and plasticisers. Using the ebuliometric method, we measured the boiling points of solutions of four binary systems formed by ethylbenzene and n-alkylbenzenes under various pressure values. Compositions of equilibrium vapour phases of the binary systems were calculated using the obtained isotherms of saturated vapour pressure of the solutions. Using the Runge-Kutta method, the composition of the vapour phases of the solutions of the systems was calculated by the numerical integration of the Duhem–Margules equation on a computer. The obtained data on the vapour-liquid equilibrium became the basis for calculating the thermodynamic functions of the systems’ solutions. The Gibbs and Helmholtz energy values, the enthalpies of vaporisation and mixing, the internal energy, and entropy of solutions were calculated. The thermodynamic properties of the solutions were calculated using a comparison of the values baed on two standards: an ideal solution and an ideal gas. It was found that the values of the Helmholtz energy linearly depend on the molar mass of the substance (the number of –CH2– groups in a molecule) in the homologous series of n-alkylbenzenes. An increase in the Helmholtz energy values for n-alkylbenzenes in the homologous series is associated with a linear increase in the molar volume of liquid substances and an exponential decrease in the saturated vapour pressure of substances. For binary solutions of constant molar concentrations formed by ethylbenzene and n-alkylbenzenes, the Helmholtz energy linearly depends on the molar mass (number of –CH2– groups in the molecule) of n-alkylbenzene in the homologous series. We obtained an equation that makes it possible to predict the thermodynamic properties of solutions of binary systems with high accuracy. The equation accelerates the process of studying vapour-liquid phase equilibria and thermodynamic properties of solutions of binary systems by 300 times. The determined patterns confirm the hypothesis of the additive contribution of functional groups to the thermodynamic properties of solutions. This hypothesis underlies the statistical theory of group models of solutions. The thermodynamic patterns determined by this study can also be used to solve a wide range of technological issues in the chemical industry.

Vapour Pressure Study of Deuterium Exchange Reactions in Water-Ethanol Systems: Equilibrium Constant Determination

1979 ◽  
Vol 32 (11) ◽  
pp. 2353 ◽  
Author(s):  
RC Phutela ◽  
ZS Kooner ◽  
DV Fenby
Keyword(s):  
Liquid Phase ◽  
Equilibrium Constant ◽  
Vapour Pressure ◽  
Equilibrium Constants ◽  
Deuterium Exchange ◽  
Pressure Measurements ◽  
Exchange Reactions ◽  
Molar Excess ◽  
Constant Determination

A method is proposed for the determination of the equilibrium constants of liquid-phase deuterium exchange reactions from vapour pressure measurements. It is applied to water-ethanol systems to give the equilibrium constant of the reaction 2C2H5OH(l) + D2(l) → 2C2H5OD(l) + H2O(l) The value obtained, 1.05+0.02 at 298 K, is significantly greater than the 'random' value and is more precise and reasonable than a recent calorimetric estimate. Vapour pressures at 298.14 K are reported for the systems H2O+C2H5OH, H2O+C2H5OD, D2O + C2H5OH and D2O + C2H5OD. Molar excess Gibbs functions are obtained from these vapour pressure measurements.

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