Calorimetric study of deuterium isotope effects in water-acetone systems

1981 ◽  
Vol 34 (3) ◽  
pp. 635 ◽  
Author(s):  
JR Khurma ◽  
DV Fenby
Keyword(s):  
Isotope Effects ◽  
Exothermic Reaction ◽  
Deuterium Exchange ◽  
Calorimetric Study ◽  
Excess Enthalpies ◽  
Exchange Reactions ◽  
Molar Excess ◽  
Deuterium Isotope Effects

Molar excess enthalpies of H20 + (CH3),CO, H20 + (CD3),C0, D20 + (CH3)2C0 and D20+ (CD3)2CO at 298.15 K are reported and, in the case of the first system, compared with earlier studies. The results are comparable to those reported for deuterium isotope effects in the molar excess enthalpies of other systems containing (CH3)2CO and (CD3)2CO; they do not suggest the occurrence of any deuterium exchange reactions. A calorimetric study of the mixing of (CD3)2CO with H2O containing a small quantity of NaOH indicates the occurrence of slow, exothermic reaction(s).

Calorimetric study of deuterium isotope effects in water-acetic acid systems

1980 ◽  
Vol 33 (11) ◽  
pp. 2349 ◽  
Author(s):  
JR Khurma ◽  
DV Fenby
Keyword(s):  
Acetic Acid ◽  
Isotope Effects ◽  
Calorimetric Study ◽  
Excess Enthalpies ◽  
Molar Excess ◽  
Deuterium Isotope Effects

The molar excess enthalpies of water+acetic acid systems are analysed to give the enthalpy of the reaction ������������� 2HA(1)+D2O(1) → 2DA(1)+H2O(1) (A=CH3COO or CD3COO) the value obtained at 298 K is -0.15�0.04 kJ mol-1. Molar excess enthalpies at 298.15 K are reported for the systems H2O+CH3COOH, H2O+CD3COOD, D2O+CH3COOH and D2O+CD3COOD.

Deuterium isotope effects in liquid-liquid phase diagrams: Water + phenol and water + 2-methylpropanoic acid systems

1983 ◽  
Vol 36 (2) ◽  
pp. 215 ◽  
Author(s):  
DV Fenby ◽  
JR Khurma ◽  
ZS Kooner ◽  
RF Smith
Keyword(s):  
Liquid Phase ◽  
Phase Diagrams ◽  
Isotope Effects ◽  
Dispersion Interactions ◽  
Exchange Reactions ◽  
Molar Excess ◽  
Deuterium Isotope Effects ◽  
London Dispersion ◽  
Molar Excess Volumes ◽  
System Water

Phase-separation temperatures Tp have been measured for the systems H2O+C6H5OH, H2O+ C6H5OD, H20+ CsD5OD, D20+ C6H50H, D2O+ C6H5OD, D2O+ C6DsOD, H2O+ (CH3)2CHCO2H and D2O+ (CH3)2CHCO2H. For water+ 2-methylpropanoic acid, the differences in the Tp-x curves for the exchange and no-exchange systems are striking. For water + phenol, on the other hand, the effect of deuterium-exchange reactions on the Tp-x curves is very small. The results for all systems are in accord with the qualitative predictions of the Rabinovich theory, which accounts for deuterium isotope effects in liquid-liquid phase diagrams in terms of hydrogen bond and London dispersion interactions. Molar excess enthalpies and molar excess volumes at 300.15 K are reported for the system water + 2-methylpropanoic acid. The results are compared with those for water + acetic acid.

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.

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.

Determination of the equilibrium constants of water-methanol deuterium exchange reactions from vapour pressure measurements

1980 ◽  
Vol 33 (1) ◽  
pp. 9 ◽  
Author(s):  
ZS Koner ◽  
RC Phutela ◽  
DV Fenby
Keyword(s):  
Equilibrium Constant ◽  
Satisfactory Agreement ◽  
Vapour Pressure ◽  
Equilibrium Constants ◽  
Deuterium Exchange ◽  
Pressure Measurements ◽  
Exchange Reactions ◽  
Molar Excess

The equilibrium constant of the reaction2CH3OH(l) + D2O(l) → 2CH3OD(l) + H2O(l) is obtained from vapour pressure measurements. The value, 1.09k0.02 at 298 K, is in satisfactory agreement with calculated values and with calorimetric estimates. Vapour pressures at 298.14 K are reported for the systems H2O + CH3OH, H2O+CH3OD, D2O + CH3OH and D2O+ CH3OD. Molar excess Gibbs functions are obtained from these vapour pressures.

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.

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