Miguel Iglesias

Thermodynamics of Ethanol + Water + 2-Propanol mixture at the range of temperature 288.15-323.15 K

The packing properties of hydroxylic chemicals is very unusual, however these substances find extensive application in food and alcoholic beverage industry. When short alcohols are mixed with water, the entropy of the final system increases far less than we could expected for an ideal solution of ramdomly interacting molecules. Experimental works on thermodynamics helps to understand how hydrophobic headgroups of alcohol molecules in aqueous media cluster together. To this aim, the densities and ultrasonic velocity of the ternary mixtures ethanol + water + 2-propanol at 288.15-323.15 K and atmospheric pressure, have been measured over the whole concentration range, due to the importance of the 2-propanol among the flavor compounds contained into spirit beverages. The experimental data have been analyzed in terms of different theoretical models, an adequate agreement between the experimental and predicted values both in magnitude and sign being obtained, despite the high non-ideal trend. The obtained experimental values indicate varying extent of interstitial accommodation among unlike molecules with strong influence of steric hindrance among aliphatic ends.