Fabio Comelli

Excess molar enthalpies of binary mixtures containing dimethyl carbonate or diethyl carbonate and one of six methyl n-alkyl ketones Application of an extended cell model

Abstract Excess molar enthalpies H E m of binary mixtures containing dimethyl carbonate or diethyl carbonate and six methyl n -alkyl ketones have been determined at 298.15 K and atmospheric pressure using a flow microcalorimeter. The systematic behaviour of H E m , increasing with the increase in the number of the carbon atoms in the ketone, is confirmed for all mixtures with the exception of mixtures of diethyl carbonate and 2-propanone. The experimental data have been correlated by means of the Redlich-Kister equation and results are interpreted in terms of molecular interactions, and are examined by an extended cell model.

Excess enthalpies for binary mixtures of toluene, p-xylene or pseudocumene + methyl-n-alkyl ketones. Application of an extended cell model

Abstract Excess molar enthalpies HE of the fifteen binary mixtures containing toluene, p-xylene or pseudocumene + five methyl-n-alkyl ketones at 298.15 K and atmospheric pressure are reported. The results confirm for p-xylene or pseudocumene + ketones the systematic behavior of HE with respect to the chain length of the ketone, whereas for the toluene + 2-undecanone mixture, an inversion in the tendency of HE has been noted (Patterson effect). The experimental data are examined by an extended cell model.

Excess molar enthalpies of binary mixtures containing dialkylcarbonates + cyclic ketones at 298.15 or 313.15 K

Abstract Excess molar enthalpies H E m for the binary mixtures containing dimethylcarbonate or diethylcarbonate + cyclohexanone, 2-methylcyclohexanone and 2,6-dimethylcyclohexanone have been determined at 298.15 and 313.15 K and at atmospheric pressure, utilizing an isothermal flow microcalorimeter. The experimental values have been correlated by the Redlich-Kister equation and the parameters have been evaluated by least-squares analysis. For all the mixtures, the H E m values are positive with a maximum ranging from + 190 up to 700 J mol −1 . All curves present a regular trend decreasing with an increase in temperature. The experimental data have been examined by an extended cell model.

A calorimetric study of propylene carbonate + acetic or propionic acid at (288.15, 298.15 and 313.15) K

Abstract Determinations of heat capacities, Cp, and excess molar enthalpies, HEm, of the binary mixtures propylene carbonate + acetic or propionic acid were carried out at (285.15, 298.15 and 313.15) K using a Perkin-Elmer DSC differential scanning calorimeter and an LKB flow microcalorimeter. All experimental values are positive and increase with the increase of temperature. The data have been fitted to a simple cubic polynomial (for Cp) and the Redlich-Kister equation (for HEm) to estimate the adjustable parameters and standard deviations of these systems. Results have been discussed in terms of molecular interactions and have been interpretated by an extended cell model.

Excess molar enthalpies and excess molar volumes of binary mixtures containing p-xylene + cyclic ethers

Abstract Excess molar enthalpies H E , and excess molar volumes V E , of mixturesof p -xyleae with the cyclic ethers oxolane, oxane, 1,3-dioxolane, and 1,4-dioxane have been determined by means of a flow microcalorimeter and a digital density meter at 298. 15″ K and afinospheric pressure. The experimental values are correlated by polynomiah equations. V E is positive over the entire range of mole fractions for p -xylene-1,4-dioxane, but is negative for the other mixtures. H E is positive for the mixtures involving the diethers-1,3-dioxolane and 1,4-dioxane, and negative for the monoethers. The heat effects are qualitatively discussed in terms of molecular interactions.

Excess molar enthalpies of diethyl carbonate + fourteen n-alkyl alkanoates at 298.15 K

Abstract Excess molar enthalpies of binary mixtures containing diethyl carbonate + fourteen n -alkyl alkanoates (six acetates, four propanoates and four butyrates) have been determined at 298.15 K and at atmospheric pressure using an LKB flow microcalorimeter. The experimental data have been fitted to the Redlich-Kister equation to estimate the binary parameters. The results have been qualitatively discussed.

Anti-inflammatory drugs. IX.

In the solid-state structure of the title compound, C(4)H(12)N(+).C(14)H(10)Cl(2)NO(2)(-).H(2)O, the asymmetric unit contains one cation, one anion and a water molecule. A complex network of hydrogen bonds is present. A comparison is made with the structure of the anhydrous salt.

Excess molar enthalpies, densities and excess molar volumes for binary mixtures containing dimethyl carbonate or diethyl carbonate + 2,2,4-trimethylpentane at 288.15, 298.15, and 313.5 K, and at atmospheric pressure. Application of an extended cell model

Abstract Excess molar enthalpies, H E m , densities, ϱ, and excess molar volumes, V E m , of dimethyl carbonate or diethyl carbonate + 2,2,4-trimethylpentane have been determined at 288.15, 298.15 and 313.15 K and at atmospheric pressure, using an LKB flow microcalorimeter and an Anton Paar digital density meter. For all mixtures, the H E m and V E m values are positive and increase slowly as the temperature is increased. The experimental values have been correlated by the Redlich-Kister equation and the adjustable parameters have been evaluated by least-squares analysis. The results are discussed qualitatively in terms of molecular interactions and have been interpreted by an extended cell model.

Calorimetric study of binary mixtures containing chlorobenzene + linear and cyclic ethers

Abstract Excess molar enthalpies H E of binary mixtures containing chlorobenzene + five ethers (oxolane, oxane, 1,4-dioxane, dimethoxymethane and 1,2-dimethoxyethane) were determined at atmospheric pressure and at 298.15 K by means of a flow microcalorimeter. Experimental H E values were correlated by the Redlich-Kister equation and the results are interpreted in terms of molecular interactions. The influence of the structural parameters on H E is assessed.

Prediction and experimental determination of thermodynamic properties of binary mixtures containing propylene carbonate +1,2-epoxybutane at (288.15, 298.15, and 313.15 K)

Abstract This paper reports experimentally determined excess molar enthalpies, HEm, excess heat capacities, CEp, densities, ρ, and excess molar volumes, VEm, of propylene carbonate +1,2-epoxybutane at (288.15, 298.15 and 313.15 K) and atmospheric pressure. The results of HEm and VEm are compared with those predicted by an extended cell model elaborated by [I. Prigogine, The Molecular Theory of Solutions, North- Holland, Amsterdam (1957)]. Experimental HEm values are positive and show only small changes with the increase of temperature, while VEm data are always negative and decrease with the increase of temperature. Also CEp values are negative for all mixtures. Results have been qualitatively interpreted in terms of molecular interactions.