Studies of hydrogen bonding in the vapor phase by measurement of thermal conductivity and molecular orbital calculations: Methanol--water binary mixtures
The thermal conductivities of serveral methanol--water binary vapor mixtures were measured in a modified thick hot-wire cell between 352 and 375 K at pressures ranging from 100 to 1400 Torr. Analysis of the data indicates that molecular association to form a 2:1 methanol--water trimeric species is a major source of enhancement of the thermal conductivity. The enthalpy and entropy of association of this trimer are -10.48 kcal mol/sup -1/ and -38.24 cal mol/sup -1/ deg/sup -1/, respectively. Theoretical calculations, based on ab initio molecular orbital calculations, of the enthalpies and entropies of association for various open chain and cyclic methanol--water trimers indicate that the 2:1 methanol--water trimeric species is more stable than the 1:2 trimeric species which is consistent with the results of the analysis of the thermal conductivity data. The theoretical calculations indicate that it may be an entropic effect which makes the 2:1 trimeric species more stable than the 1:2 species.
- Research Organization:
- Chemical Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439
- DOE Contract Number:
- W-31-109-ENG 38
- OSTI ID:
- 6007599
- Journal Information:
- J. Chem. Phys.; (United States), Vol. 75:12
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
METHANOL
CHEMICAL BONDS
THERMAL CONDUCTIVITY
WATER
WATER VAPOR
BINARY MIXTURES
ENTHALPY
ENTROPY
HYDROGEN
LOW PRESSURE
MEDIUM PRESSURE
MEDIUM TEMPERATURE
MOLECULAR ORBITAL METHOD
VAPORS
ALCOHOLS
DISPERSIONS
ELEMENTS
FLUIDS
GASES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
MIXTURES
NONMETALS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)