ентальпія змішування

In this study, the temperature dependences of the solubility of 5-(4-methylphenyl)-2-furanpropanoic acid in various solvents were evaluated: methyl and ethyl acetate, acetonitrile, propane-1-ol, and propan-2-ol. The results of the analysis are presented in the form of linear equations according to the Schröder model, which allowed us to determine the enthalpies, entropies, and Gibbs energies of solubility at a temperature of 298.15 K.

Based on the temperature dependence of the solubility of 5-(2-nitrophenyl)-furan-2-carboxylic acid, 5-(3-nitrophenyl)-furan-2-carboxylic acid and 5-(4-nitrophenyl)-furan-2-carboxylic acid in propan-2-ol, the enthalpy and entropy of their dissolution were calculated. Taking into account the enthalpy and entropy of melting recalculated to 298 K, the enthalpies and entropies of mixing were calculated. The dependence of the solubility of carboxyl-containing substances at 298 K on their melting point was determined.

The fusion temperature of 2-cyano-3-[5-(phenyl)-2-furyl]-2-propenamide and 2-cyano-3-[5-(4-methylphenyl)-2-furyl]-2-propenamide and their temperature dependence of dissolution in acetonitrile, benzene, dimethylketone, ethyl acetate and 2-propanol have been determined. According to the temperature dependence the differential enthalpies and entropies of the solution were calculated. Taking into account the entropies of fusion the entropies and enthalpies of mixing were calculated at 298 K.

Калориметричним методом визначені ентальпії змішування бінарних систем лаурилметакрилату з гексаном, бензеном, 1,2-дихлоретаном та оцтовою кислотою за температури 293 К та атмосферного тиску. Концентраційні залежності ентальпії змішування апроксимовані степеневими поліномами. Для системи оцтова кислота - лаурилметакрилат ентальпія змішування набуває додатних значень у всьому дослідженому діапазоні концентрацій, а для решти досліджених систем ентальпія додатна для концентрацій розчинника вищих за 25 % мол.