D. Bennett, W. J. Canady
Feb 22, 1984
Citations
0
Influential Citations
30
Citations
Journal
Journal of the American Chemical Society
Abstract
The temperature dependences of the solubilities of naphthalene in water and in various water-ethanol mixtures up to 0.07 mol fraction of ethanol have been determined. In the concentration range studied, a plot of the free energy of solution of naphthalene vs. mole fraction of ethanol present in the solvent is linear. The heat of solution of naphthalene in water is positive and becomes more positive as the ethanol concentration is increased. This heat term is more than overcome by a concomitant large increase in the entropy of solution, the net effect being to solubilize the hydrocarbon by the addition of ethanol. The addition of ethanol to the aqueous phase is much more effective in solubilizing naphthalene at high rather than low temperatures. The results may be interpreted in terms of the McMillian-Mayer second virial coefficient. It is suggested that ethanol may exert its influence upon hydrocarbon solubility by loss of water structure as hydrophobic interactions take place between the hydrocarbon and alcohol. Dispersal of an iceberg or clathrate structure probably makes a significant contribution.