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.

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).

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.

THE CHROMIC ACID OXIDATION OF ARYL TRIFLUOROMETHYL ALCOHOLS: ISOTOPE AND SUBSTITUENT EFFECTS

1964 ◽  
Vol 42 (2) ◽  
pp. 439-446 ◽  
Author(s):  
Ross Stewart ◽  
Donald G. Lee
Keyword(s):  
Acetic Acid ◽  
Acid Solution ◽  
Chromic Acid ◽  
Isotope Effects ◽  
Acetic Acid Solution ◽  
Substituent Effects ◽  
Acid Oxidation ◽  
Unimolecular Decomposition ◽  
Chromic Acid Oxidation ◽  
Deuterium Isotope Effects

The mechanism of the chromic acid oxidation of eight aryltrmuoromethylcarbinols has been studied in acetic acid solution. Electron-donating substituents accelerate the reaction and a good correlation of rate with σ+ values has been found. The rho value is −1.01. Deuterium isotope effects for the oxidation of five of these compounds have been determined and the magnitude of the isotope effect has been found to correlate inversely with the ease of oxidation of the alcohol.The results are interpreted in terms of a unimolecular decomposition of the chromate ester of the alcohol.

Les systèmes eau/ester. I. Etude calorimétrique des systèmes eau/acétate d'alcoyle

1976 ◽  
Vol 54 (16) ◽  
pp. 2584-2593 ◽  
Author(s):  
Dominique Richon ◽  
André Viallard
Keyword(s):  
Homologous Series ◽  
Water Systems ◽  
Calorimetric Study ◽  
Thermodynamic Quantities ◽  
Excess Enthalpies ◽  
Molar Excess ◽  
Alkyl Acetate ◽  
Mutual Solubilities ◽  
Enthalpies Of Solvation

A calorimetric study of alkyl acetate/water systems has been carried out in the complete homogeneous and heterogeneous domain of mole fractions. The sign, intensity, and trends of excess enthalpies and mutual solubilities are discussed.Values of the excess enthalpies for ester/water homogeneous mixtures are used for the determination of partial molar excess enthalpies and enthalpies of "solvation" at infinite dilution.The trends of the thermodynamic quantities in this homologous series are discussed in terms of ester/water interactions.

Deuterium Isotope Effects on the Ionization Constant of Acetic Acid in H2O and D2O by AC Conductance from 368 to 548 K at 20 MPa

2011 ◽  
Vol 115 (12) ◽  
pp. 3038-3051 ◽  
Author(s):  
K. M. Erickson ◽  
H. Arcis ◽  
D. Raffa ◽  
G. H. Zimmerman ◽  
P. R. Tremaine
Keyword(s):  
Acetic Acid ◽  
Ionization Constant ◽  
Isotope Effects ◽  
Deuterium Isotope Effects ◽  
Ac Conductance

Mechanism of hydration and isomerisation of 4-ethylidene-2,6-di-tert-butyl-2,5-cyclohexadien-1-one. Kinetics, acid-base catalysis and solvent deuterium isotope effects

1979 ◽  
Vol 44 (1) ◽  
pp. 110-122 ◽  
Author(s):  
Jiří Velek ◽  
Bohumír Koutek ◽  
Milan Souček
Keyword(s):  
Aqueous Medium ◽  
Rate Equation ◽  
Kinetic Data ◽  
Isotope Effects ◽  
Base Catalysis ◽  
Quinone Methide ◽  
Reaction Products ◽  
Acid Base ◽  
Deuterium Isotope Effects ◽  
Hydroxybenzyl Alcohol

Competitive hydration and isomerisation of the quinone methide I at 25 °C in an aqueous medium in the region of pH 2.4-13.0 was studied spectrophotometrically. The only reaction products in the studied range of pH are 4-hydroxybenzyl alcohol (II) and 4-hydroxystyrene (III). The form of the overall rate equation corresponds to a general acid-base catalysis. The mechanism of both reactions for three markedly separated pH regions is discussed on the basis of kinetic data and solvent deuterium effect.

Sign in / Sign up

Export Citation Format

Share Document