Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5413249 | Journal of Molecular Liquids | 2008 | 9 Pages |
Abstract
The ultrasonic speeds, u and viscosities, η of binary mixtures of formamide (FA) with ethanol, 1-propanol, 1,2-ethanediol, and 1,2-propanediol, including those of pure liquids, over the entire composition range were measured at 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15 K. From the experimental values of u and η, the deviations in isentropic compressibility, Îks, in ultrasonic speed, Îu, and in viscosity, Îη were calculated. The variation of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interaction in these mixtures. The observed trends in Îks values indicate the presence of specific interactions between FA and alkanol molecules. The Îks values follow the order: ethanol < 1-propanol < 1,2-propanediol < 1,2-ethanediol. It is observed that the Îks values depend upon the number of hydroxyl groups and alkyl chain length in these alkanol molecules. Furthermore, the free energies, ÎGâ, enthalpies, ÎHâ and entropies, ÎSâ of activation of viscous flow have also been obtained by using Eyring viscosity equation and their dependence on composition of the mixtures have been discussed.
Keywords
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Anil Kumar Nain,