Vapour–liquid equilibria of butyl acetate with aromatic hydrocarbons at 298.15 K

Vapour pressures of butyl acetate?+?benzene or toluene or o- or m- or p-xylene were measured by static method at 298.15?±?0.01?K over the entire composition range. The activity coefficients and excess molar Gibb's free energies of mixing (G ^E) for these binary mixtures were calculated by fitting vapour pressure data to the Redlich–Kister equation using Barker's method of minimizing the residual pressure. The G ^E values for the binary mixtures containing benzene are positive; while these are negative for toluene, ortho, meta and para xylene system over the whole composition range. The G ^E values of an equimolar mixture for these systems vary in the order: benzene?>?m-xylene?>?o-xylene?>?p-xylene?>?toluene     

Excess properties and vapour pressure of {3-diethylaminopropylamine + cyclohexane}

The vapour pressures of liquid {3-diethylaminopropylamine (3-DEPA) + cyclohexane} were measured by a static method between T = (273.15 and 363.15) K at 10 K intervals. The excess molar volumes V^E at 298.15 K and excess molar enthalpies H^E at 303.15 K were also measured. The molar excess Gibbs free energies G^E were obtained with Barker’s method and fitted to the Redlich–Kister equation. The Wilson equation was also used. Deviations between experimental and predicted G^E and H^E, by using DISQUAC model, were evaluated     

Vapour pressure and excess Gibbs energy of binary 1,2-dichloroethane + cyclohexanone,chloroform + cyclopentanone and chloroform + cyclohexanone mixtures at temperatures from 298.15 to 318.15 K

The vapour pressures of the binary systems 1,2-dichloroethane + cyclohexanone, chloroform + cyclopentanone and chloroform + cyclohexanone mixtures were measured at temperatures between 298.15 and 318.15 K. The vapour pressures vs. liquid phase composition data for three isotherms have been used to calculate the activity coefficients of the two components and the excess molar Gibbs energies, G^E, for these mixtures, using Barker's method. Redlich–Kister, Wilson, NRTL and UNIQUAC equations, taking into account the vapour phase imperfection in terms of the 2-nd virial coefficient, have represented the G^E values. No significant difference between G^E values obtained with these equations has been observed. Our data on vapour–liquid equilibria (VLE) and excess properties of the studied systems are examined in terms of the DISQUAC and modified UNIFAC (Dortmund) predictive group contributions models.     

Thermodynamics of the xenon + methyl chloride system

The total vapour pressure of the xenon + methyl chloride system has been measured as a function of composition at 175.44 and 182.32 K. The resulting data have been used to evaluate the excess Gibbs functions G^E at the same temperatures. The excess enthalpy and excess molar volume have also been measured at 182.32 K. The system shows large positive deviations from Raoult's law but negative volumes on mixing. These results are compared with theoretical predictions of a recent molecular theory and of standard engineering methods. The calculations show the superiority of the molecular theory over more empirical procedures such as those based on the Redlich-Kwong equation of state or the regular-solution model.     

Vapor–liquid equilibria of 2-butanol + aromatic hydrocarbons at 308.15 k

Vapor–liquid equilibria (VLE) data of 2-butanol?+?benzene or toluene or o- or m- or p-xylene measured by static method at 308.15?±?0.01?K over the entire composition range are reported. The excess molar Gibbs free energies of mixing (G ^E) for these binary systems have been calculated from total vapor pressure data using Barker's method. The G ^E for these binary systems are also analyzed in terms of the Mecke–Kempter type of association model with a Flory contribution term using two interaction parameters and it has been found that this model describes well the G ^E values of binary systems benzene or toluene.     

Measurement and Correlation of Excess Molar Enthalpy of Binary Mixtures Containing Butyl Acetate + 1-Alkanols (C1–C6) at 298.15 K

Excess molar enthalpies, ?H _m ^E , for the binary mixtures of butyl acetate + 1-alkanols, 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, ?H _m,i ^E , were calculated from the experimental excess molar enthalpies using the Redlich–Kister polynomial equation. The sign of ?H _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 ?H _m ^E values increases with increasing alkyl chain length. The behavior of ?H _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).     

Vapour–liquid equilibria,enthalpy of mixing of binary mixtures containing diisopropylether ‘DIPE’ and monoaromatic hydrocarbons: Experimental results and modelling

The experimental isothermal P–x–y data between 263.15 and 343.15 K at 10 K intervals of liquid binary mixtures 2,2′-oxybis[propane] (diisopropylether or DIPE) + toluene, +m-xylene and of the three pure components are reported. Data reduction by Barker's method provides correlation for excess molar Gibbs energy (G^E).     

Densities and volumetric properties of a (xylene + dimethyl sulfoxide) at temperature from (293.15 to 353.15) K

The densities of (o-xylene, or m-xylene, or p-xylene + dimethyl sulfoxide) were measured at temperatures (293.15, 303.15, 313.15, 323.15, 333.15, 343.15, 353.15) K and atmospheric pressure by means of a vibrating-tube densimeter. The excess molar volume V_m^E calculated from the density data provide the temperature dependence of V_m^E in the temperature range of (293.15 to 353.15) K. The V_m^E results were correlated using the fourth-order Redlich–Kister equation, with the maximum likelihood principle being applied for the determination of the adjustable parameters. Also we have calculated partial molar volume and excess partial molar volumes of two components. It was found that the V_m^E in the systems studied increase with rising temperature.     

Thermodynamics of mixtures with strongly negative deviations from Raoult’s law: Part 6. Excess molar volumes at 298.15 K for 1-alkanols + dibutylamine systems. Characterization in terms of the ERAS model

Excess molar volumes, V_m^E, at 298.15 K and atmospheric pressure over the entire composition range for binary mixtures of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol with dibutylamine are reported. They are calculated from densities measured with a vibrating-tube densimeter. All the excess volumes are large and negative over the whole mole fraction range, indicating strong interactions between unlike molecules, which are more important for the systems involving methanol or ethanol, characterized by the most negative V_m^E. For the other mixtures, V_m^E at equimolar composition, is approximately constant. The V_m^E curves are nearly symmetrical. The V_m^E and excess molar enthalpies (H_m^E) of the mixtures studied are consistently described by the ERAS model. The ERAS parameters confirm that the strongest interactions between unlike molecules are encountered in the methanol+dibutylamine system.     

Thermodynamic properties of binary mixtures containing n-alkylamines: I. Isothermal vapour–liquid equilibrium and excess molar enthalpy of n-alkylamine+toluene mixtures. Measurement and analysis in terms of group contributions

Molar excess enthalpies, H^E, at 303.15 K and atmospheric pressure, of n-propyl-, n-butyl-, n-pentyl-, n-octyl- or n-decylamine+toluene, as well as the isothermal vapour–liquid equilibria, VLE, of n-butylamine+toluene and of n-butylamine+benzene at 298.15 K have been determined. These experimental results, along with the data available in the literature on molar excess Gibbs energies, G^E, activity coefficients at infinite dilution, γ_i^∞, and molar excess enthalpies, H^E, for n-alkylamine+toluene mixtures are examined on the basis of the DISQUAC group contribution model. The modified UNIFAC is also used to describe the mixtures.     

(Vapour + liquid) equilibria and excess Gibbs free energies of (cyclohexanone + 1-chlorobutane and + 1,1,1-trichloroethane) binary mixtures at temperatures from (298.15 to 318.15) K

The vapour pressures of binary (cyclohexanone + 1-chlorobutane, + 1,1,1-trichloroethane) mixtures were measured at the temperatures of (298.15, 308.15, and 318.15) K. The vapour pressures vs. liquid phase composition data have been used to calculate the excess molar Gibbs free energies G^E of the investigated systems, using Barker’s method. Redlich–Kister, Wilson, UNIQUAC, and NRTL equations, taking into account the vapour phase imperfection in terms of the 2-nd virial coefficient, have represented the G^E values. No significant difference between G^E values obtained with these equations has been observed.     

Isothermal (vapour + liquid) equilibria and excess Gibbs free energies in some binary (cyclopentanone + chloroalkane) mixtures at temperatures from 298.15 K to 318.15 K

The vapour pressures of binary (cyclopentanone + 1-chlorobutane, +1,3-dichloropropane, and +1,4-dichlorobutane) mixtures, were measured at the temperatures of (298.15, 308.15, and 318.15) K. The vapour pressures vs. liquid phase composition data have been used to calculate the excess molar Gibbs free energies G^E of the investigated systems, using Barker’s method. Redlich–Kister, Wilson and NRTL equations, taking into account the vapor phase imperfection in terms of the second virial coefficient, have represented the G^E values. No significant difference between G^E values obtained with these equations has been observed.     

Excess properties and vapour pressure of (3-diethylaminopropylamine + n-alkanes)

The vapour pressures of liquid (3-diethylaminopropylamine (3-DEPA) + n-heptane) mixtures were measured by a static method between T = (303.15 and 343.15) K at 10 K intervals. The molar excess enthalpies H^E at T = 303.15 K were measured for the systems {3-DEPA + C_nH_2n+2 (n = 6, 7, 12)}. The molar excess Gibbs free energies G^E were obtained with Barker’s method and fitted to the Redlich–Kister equation. The Wilson equation was also used. Deviations between experimental and predicted G^E and H^E, by using group contribution UNIFAC (Gmehling version) model, were evaluated.     

Volumetric and Transport Properties of Ternary Mixtures Containing 1-Butanol or 1-Pentanol,Triethylamine and Cyclohexane at 303.15 K: Experimental Data,Correlation and Prediction by the ERAS Model

The excess molar volumes, V _m^E, viscosity deviations, Δη, and excess Gibbs energies of activation, ΔG ^*E, of viscous flow have been investigated from density and viscosity measurements for two ternary mixtures, 1-butanol + triethylamine + cyclohexane and 1-pentanol + triethylamine + cyclohexane, and corresponding binaries at 303.15 K and atmospheric pressure over the entire range of composition. The empirical equations due to Redlich-Kister, Kohler, Rastogi et al., Jacob-Fitzner, Tsao-Smith, Lark et al., Heric-Brewer, and Singh et al. have been employed to correlate V _m^E, Δη and ΔG ^*E of the ternary mixtures with their corresponding binary parameters. The results are discussed in terms of the molecular interactions between the components of the mixture. Further, the Extended Real Associated Solution, ERAS, model has been applied to V _m^E for the present binary and ternary mixtures, and the results are compared with experimental data.     

Thermodynamic properties of liquid mixtures of carbon monoxide and methane

The equations of state of liquid methane at 125.00 K and of six liquid mixtures of carbon monoxide and methane at 116.30, 120.00 and 125.00 K have been measured from just above the saturation vapour pressure to the freezing pressure of methane. The results show that the excess volume V^E is large and negative at low pressures but becomes less negative as the pressure is increased, being almost zero at the highest pressures. The curve of V^E against the mole fraction x is very asymmetrical at low pressures, but becomes more symmetrical with rising pressure.The effect of pressure on the excess functions G^E, H^E and T·S^E has been calculated. H^E and T·S^E prove to be much more sensitive to pressure than G^E.Conformal solution theory, in the van der Waals one-fluid form, reproduces the experimental results very successfully.     

Analysis of {α,ω-Dichloroalkane or α,ω-Dibromoalkane] + Benzene and α,ω-Dichloroalkane + Tetrachloromethane} Mixtures in Terms of Group Contributions

Abstract

Molar excess enthalpies, H ^E _m, at 298.15K and atmospheric pressure have been determined for three binary liquid mixtures [x{1,3-dichloropropane or 1,4-dichlorobutane and 1,6-dichlorohexane} + (1 - x) tetrachloromethane]. These experimental results along with the data available in the literature on molar excess Gibbs energies, G ^E _m, activity coefficients at infinite dilution, In γ^∞ _i , and molar excess enthalpies, H ^E _m, for α,ω-dihaloalkanes + benzene or + tetrachloromethane mixtures are examined on the basis of the DISQUAC group contribution model.     

Measurements of HmE and VmE for (n-butane + sulphur hexafluoride) in the supercritical region at the pressure 6.00 MPa

A flow mixing calorimeter followed by a vibrating-tube densimeter has been used to measure excess molar enthalpies H_m^E and excess molar volumes V_m^E of {xC₄H₁₀+(1−x)SF₆}. Measurements over a range of mole fractions x have been made in the supercritical region at the pressure p=6.00 MPa and at seven temperatures in the range T=311.25 K to T=425.55 K. The H_m^E(x) measurements at T=351.35 K were found to exhibit an unusual double maximum. Measurements at all temperatures are compared with the Patel–Teja equation of state with the parameters determined by solving a cubic equation as recommended, and also with parameters determined by the method suggested by Valderamma and Cisternas who proposed equations which are a function of the critical compression factor. The overall fit to the H_m^E and V_m^E measurements obtained using Valderamma and Cisternas equations was found to be better than that obtained using the parameters according to the method suggested by Patel and Teja.     

Measurements of excess molar enthalpy and excess molar heat capacity of (1-heptanol or 1-octanol)+(diethylamine or <Emphasis Type="Italic">s</Emphasis>-butylamine) mixtures at 298.15 K and 0.1 MPa

Experimental data of excess molar enthalpy (H _m^E) and excess molar heat capacity (C _pm^E) of binary mixtures containing (1-heptanol or 1-octanol)+(diethylamine or s-butylamine) have been determined as a function of composition at 298.15 K and at 0.1 MPa using a modified 1455 Parr solution calorimeter. The excess molar enthalpy data are negative and show parabolic format over the whole composition range; however, the excess molar heat capacity values, whose curves show a S-shape, are positive in the 0.0 to 0.7 molar fraction range and negative between the molar fraction values 0.7 to 1.0. The applicability of the ERAS-model to correlate the excess molar enthalpy data was tested. The calculated data values are in good agreement with the experimental ones. The experimental behavior of H _m^E is interpreted in terms of specific interactions between 1-alkanol and amine molecules.     

Excess Gibbs energies and volumes of the ternary system chloroform + tetrahydrofuran + cyclohexane at 298.15 K

Vapour–liquid equilibria and densities for the ternary system chloroform + tetrahydrofuran + cyclohexane and for the binary mixtures containing chloroform have been determined at 298.15 K. Vapour–liquid equilibrium data have been collected by head-space gas-chromatographic analysis of the vapour phase directly withdrawn from an equilibration apparatus. Density measurements have been carried out by means of a vibrating tube densimeter. Molar excess Gibbs energies G^E and volumes V^E, as well as activity coefficients and apparent molar volumes of the components, have been obtained from the measured quantities and discussed. The binary chloroform + tetrahydrofuran displays negative deviations from ideality, while chloroform + cyclohexane positive deviations, for both volume and Gibbs energy. The G^E's and V^E's for the ternary system are positive in the region rich in cyclohexane while negative in the region rich in chloroform + tetrahydrofuran. This indicates that hydrogen bonding between chloroform and tetrahydrofuran molecules produces negative values of G^E and V^E and strongly influences the behaviour of the ternary system.