Excess properties of mixtures of some n -alkoxyethanols with organic solvents. V. Excess enthalpies of 2-butoxyethanol with normal alkanes at 298.15 K (original) (raw)
Journal of Solution Chemistry, 2014
Excess molar enthalpies, DH m E , for the binary mixtures of butyl acetate ? 1alkanols, namely (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol), were measured over the whole range of composition at 298.15 K using a Parr 1455 solution calorimeter. The excess partial molar enthalpies, DH m,i E , were calculated from the experimental excess molar enthalpies using the Redlich-Kister polynomial equation. The sign of DH m E for all systems are positive because of the disruption of hydrogen bonding and dipole-dipole interactions in the alkanols and esters, respectively. The magnitude of the DH m E values increases with increasing alkyl chain length. The behavior of DH m E was analyzed in terms of the length of the alkanol chain, the nature and type of intermolecular interactions and the balance between positive and negative effects on deviations from ideality. The experimental excess molar enthalpy data have also been correlated using the Redlich-Kister and SSF equations and two local composition models (UNIQUAC and NRTL).
Journal of Chemical & Engineering Data, 2000
Experimental data are reported at 298.15 K of excess molar volumes V E and of excess molar enthalpies H E for binary and ternary mixtures of an alkanol (1-propanol or 1-butanol), an ether (diisopropyl ether or dibutyl ether), and an alkane (heptane). A vibrating-tube densitometer was used to determine V E. H E was measured using a quasi-isothermal flow calorimeter. The experimental results are used to test the applicability of the modified UNIFAC model for correlating H E and of the ERAS model for describing both V E and H E of binary mixtures as well as for predicting the excess properties of ternary mixtures containing an alkanol, an ether, and an alkane. For all investigated binary systems, a better description of the experimental data was achieved with the ERAS model in comparison with the modified UNIFAC model.
Fluid Phase Equilibria, 1999
Excess molar enthalpies and excess molar heat capacities of the binary mixtures x 2-ethoxyethanol, or Ž. 4 2-propoxyethanol, or 2-isopropoxyethanol, or 2-butoxyethanol, or 2-isobutoxyethanolq 1 y x n-octane have been measured at 298.15 K. Results have been compared with UNIFAC and DISQUAC calculations. Excess enthalpies are positive and do not differ very much in magnitude for all systems. Both excess enthalpies and excess heat capacities are positive and rather large. UNIFAC and DISQUAC models reproduce the experimental data fairly well. However, excess heat capacities are better correlated by DISQUAC.
Thermodynamic properties of n-alkoxyethanols+organic solvents mixtures
Fluid Phase Equilibria, 1998
Liquid-liquid equilibria LLE data are reported for 2-methoxyethanolq n-pentane, qn-hexane, qn-octane, qn-decane, or qcyclohexane mixtures at atmospheric pressure, between 281 K and the upper critical solutions Ž . temperatures UCST . The coexistence curves were determined visually. These curves are rather symmetrical, with the asymmetry increasing with the size of the n-alkane. The UCSTs increase almost linearly with the Ž . number of the carbon atoms of the n-alkane. The system with cyclohexane shows the lower UCST. The x,T < < m Ä Ž .4 Ä Ž data were fitted to the equation T s T q k yy y where y s g x r 1 q x g y 1 and y s g .4 y 1 . T and x are the coordinates of the critical points fitted together with k, m and g using a Marquardt c 1 c algorithm. The critical exponents of the order parameter for the mixtures studied are calculated. Its mean value is 0.363. q 1998 Elsevier Science B.V.
Excess Molar Enthalpies of Binary Mixtures of Trichloroethylene with Six 2-Alkanols at 25°C
Journal of Solution Chemistry, 2001
Excess molar enthalpies HE have been measured for the binary mixtures trichloroethylene + 2-propanol, + 2-butanol, + 2-pentanol, + 2-hexanol, + 2-heptanol, and + 2-octanol using an isothermal microcalorimeter at 25°C. All the mixtures present exothermic events and showed minimum negative HE values around 0.50–0.60 mole fraction of trichloroethylene. Minimum values of HE vary from 450 J-mol-1 up to 530