ентальпія

The temperature dependences of the solubility of 2-methyl-5-(2-chloro-5-trifluoromethylphenyl)-furan-3-carboxylic acid and 2-methyl-5-(2,5-dichlorophenyl)-furan-3-carboxylic acid in acetonitrile, dimethyl ketone, isopropanol and ethyl acetate have been experimentally determined. The enthalpies of fusion of the investigated substances, as well as their enthalpies and entropies of mixing at 298 K have been calculated. The dependence of the saturated solution concentration on the values of enthalpy and entropy of solubility at 298 K has been determined.

The temperature dependencies of both acids solubility in acetonitrile, dimethylketone, isopropanol, ethylacetate and benzene were investigated. The results were represented by Shredder’s equation according to which enthalpies, entropies and Gibbs energy of solubility at 298 K were determined. Fusion heats of the acids were determined using differential thermal analysis. In accordance with obtained values the enthalpies, entropies and Gibbs energy of mixing were calculated. The compensating effect of mixing was observed for al solvents with carboxy group.