Excess thermodynamics properties of propyl propanoate+hexane+cyclohexane at 298.15 K

Summary In this paper we present excess molar volumes and excess molar enthalpies of binary and ternary mixtures containing propyl propanoate, hexane and cyclohexane as components at 298.15 K. Excess molar volumes were calculated from the density of the pure liquids and mixtures. The density was measured using an Anton Paar DMA 60/602 vibrating-tube densimeter. Excess molar enthalpies were obtained using a Calvet microcalorimeter     

Volumetric Properties of Ternary-Pseudobinary Mixtures Containing Benzene and Cyclohexane

Densities have been measured as a function of composition for ternary-pseudobinary mixtures of [(benzene + toluene or methylcyclohexane) + (cyclohexane + toluene or methylcyclohexane)] by means of a vibrating-tube densimeter at atmospheric pressure and the temperature 298.15 K. The excess molar volumes, V_m^E, were calculated from the densities and correlated using the Redlich–Kister equation to estimate the coefficients and standard errors. The experimental and calculated quantities are used to discuss the mixing behavior of the components. The results show the third component, toluene and methylcyclohexane, influences the interaction between benzene and cyclohexane.     

Vapour pressures and excess functions of N, N, N′, N′-tetramethylalkanediamine + cyclohexane. A group contribution study of the N---N proximity effect

The vapour pressuresof liquid cyclohexane + N, N, N′, N′-tetramethylalkanediamine, (CH₃)₂ N(CH₂)_uN(CH₃)₂ (u = 1,2) + cyclohexane mixtures were measured by a static method between 303.15 and 343.15 K at 10 K intervals. The excess molar enthalpies at 303.15 K were also measured.

The molar excess Gibbs energies, calculated from the vapour-liquid equilibrium data, and the molar excess enthalpies compare satisfactorily with group contribution (DISQUAC) predictions.

The proximity effect of N atoms produces a regular decrease of the interactional parameters.     

Excess molar enthalpies of the ternary mixtures: (diisopropyl ether or 2-methyltetrahydrofuran) + cyclohexane + n-heptane at 298.15 K

Microcalorimetric measurements of excess molar enthalpies, at 298.15 K, are reported for the two ternary systems formed by mixing either diisopropyl ether or 2-methyltetrahydrofuran with binary mixtures of cyclohexane and n-heptane. Smooth representations of the results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. It is shown that useful estimates of the ternary enthalpies can be obtained from the Liebermann and Fried model, using only the physical properties of the components and their binary mixtures.     

Excess Enthalpies of 2-Methyltetrahydrofuran + (2,2,4-Trimethylpentane or n-Heptane) + Methylcyclohexane at 25°C

Measurements of excess molar enthalpies at 25°C in a flow microcalorimeter, are reported for the two ternary mixtures 2-methyltetrahydrofuran + 2, 2, 4-trimethylpentane + methylcyclohexane and 2-methyltetrahydrofuran + n-heptane + methylcyclohexane. Smooth representations of the results are described and used to construct constant-enthalpy contours on Roozeboom diagrams. It is shown that useful estimates of the ternary enthalpies can be obtained from the Liebermann–Fried model using only the physical properties of the components and their binary mixtures.     

Excess molar enthalpies of binary mixtures of 1-hexene with some cyclic and aromatic hydrocarbons at 298.15 K

Microcalorimetric measurements of excess molar enthalpies, at 298.15 K, are reported for the four binary systems formed by mixing 1-hexene with the cycloalkanes: cyclohexane and methylcyclohexane, and with the aromatic hydrocarcons: benzene and toluene. Smooth Redlich-Kister representations of the results are presented. It was found that the Liebermann-Fried model also provided good representations of the results.     

Viscosities of the ternary mixture (cyclohexane+tetrahydrofuran+chlorocyclohexane) at 298.15 and 313.15 K

Viscosities of the ternary mixture (cyclohexane+tetrahydrofuran+chlorocyclohexane) and the binary mixtures (cyclohexane+tetrahydrofuran and cyclohexane+chlorocyclohexane) have been measured at normal pressure at the temperatures of 298.15 and 313.15 K. The viscosity data for the binary and ternary mixtures were fitted to a McAllister-type equation [R.A. McAllister, AIChE J. 6 (1960) 427–431]. Viscosity deviations for the binary and ternary mixtures were fitted to Redlich–Kister's and Cibulka's equations [I. Cibulka, Coll. Czech. Chem. Commun. 47 (1982) 1414–1419]. The group contribution method proposed by Wu [D.T. Wu, Fluid Phase Equilib. 30 (1986) 149–156] has been used to predict the viscosity of the binary and ternary systems.     

Excess molar enthalpies and excess molar heat capacities of (2-butanone + cyclohexane,or methylcyclohexane,or benzene,or toluene,or chlorobenzene,or cyclohexanone) atT = 298.15 K

Excess molar enthalpies of (2- butanone  +  cyclohexane, or methylcyclohexane, or toluene, or chlorobenzene, or cyclohexanone) and excess molar heat capacities of (2- butanone  +  benzene, or toluene, or chlorobenzene, or cyclohexanone) were measured atT =  298.15 K. Aliphatic systems were endothermic and the chlorobenzene system was exothermic. On the other hand, the toluene system changed sign to be S-shaped similar to the benzene system reported by Kiyohara et al. The values of excess molar enthalpies of the present mixtures were slightly larger than the corresponding mixtures of cyclohexanone already reported. Excess molar heat capacities of aromatic systems were characteristically S-shaped for the mixture containing aromatics. The values of the present mixtures were less than the corresponding mixtures of cyclohexanone. The mixture (2-butanone  +  cyclohexanone) was endothermic forH_m^E and negative for C_p,m^E.     

Excess molar enthalpies for binary mixtures of different amines with water

The isothermal excess molar enthalpies for binary mixtures of different amines with water were measured with a C-80 Setaram calorimeter. The experimental results indicate that the excess molar enthalpy is related to the molecular structure. The experimental excess molar enthalpies were satisfactorily fitted with the Redlich–Kister equation. They were also used to test the suitability of the NRTL model, and the deviations are a little larger than the R–K equation.     

Determination of excess volumes in 1,2-dichloroethane + benzene, + toluene, + p-xylene, + cyclohexane,and + methylcyclohexane with a vibrating-tube densimeter

Densities of mixtures of 1,2-dichloroethane + benzene, + toluene, + p-xylene, + cyclohexane, and + methylcyclohexane were measured at 298.15 K over the whole concentration range by means of a vibrating-tube densimeter. Molar excess volumes were calculated from the results and compared to values obtained by interpolation or extrapolation of literature data.     

Excess molar enthalpies of (methylcyclohexane+an alkanol) at 323.15 K I. Results for n-butanol,n-pentanol,and n-hexanol

Calorimetric measurements of excess molar enthalpies are reported for (methylcyclohexane + n-butanol or n-pentanol or n-hexanol) at 323.15 K. To each set of results variable-degree polynomials were fitted by the least-squares method.     

Thermodynamic functions for the systems 1-butanol, 2-butanol,andt-butanol + cyclohexane

The following properties of mixtures of the butanols with cyclohexane were measured over the whole range of composition: 1-butanol+cyclohexane and 2-butanol+cyclohexane; excess enthalpies at 15, 25, 35 and 45°C, excess volumes at 25 and 45°C, activity coefficients and excess Gibbs free energies at 45°C. 2-Methylpropan-2-ol (tertiary butanol)+cyclohexane; excess enthalpies at 26, 35, and 45°C, excess volumes at 26 and 45°C, activity coefficients and excess Gibbs free energies at 45°C. From these data, activity coefficients at the temperatures of the excess enthalpy measurements below 45°C have been computed, as a source of test data for models of alcohol association through hydrogen bonding.     

Thermodynamics of mixtures containing a very strongly polar compound: IV – application of the DISQUAC,UNIFAC and ERAS models to DMSO+ organic solvent systems

Binary mixtures of dimethylsulfoxide (DMSO) with alkane, benzene, toluene 1-alkanol, or 1-alkyne have been investigated in terms of DISQUAC. The corresponding interaction parameters are reported. ERAS parameters for 1-alkanol + DMSO mixtures are also given. ERAS calculations were developed considering DMSO as a not self-associated compound.

DISQUAC represents fairly well a complete set of thermodynamic properties: molar excess enthalpies, molar excess Gibbs energies, vapor–liquid equilibria, natural logarithms of activity coefficients at infinite dilution, or partial molar excess enthalpies at infinite dilution. DISQUAC improves UNIFAC calculations for H ^E . Both models yield similar results for VLE. In addition, DISQUAC also improves, ERAS results for 1-alkanol + DMSO mixtures. This may be due to ERAS cannot represent the strong dipole–dipole interactions present in such solutions.     

Excess enthalpies of 2-propanol + cyclohexane and 2-propanol + benzene + cyclohexane at 298.15 K

With an isothermal dilution calorimeter excess enthalpies have been determined at 298.15 K for 2-propanol + cyclohexane and 2-propanol + benzene + cyclohexane mixtures. The results are fitted with an associated-solution model. Predicted excess enthalpies for the ternary mixture agree well with the experimental results.     

Excess Molar Volumes, Excess Molar Enthalpies, and Excess Isentropic Compressibilities of Binary Mixtures Containing N-Methyl-2-Pyrrolidone and Isomeric Xylenes at 308.15?K

Excess molar volumes, excess molar enthalpies and speeds of sound of 1-methyl pyrrolidin-2-one?+?o- or m- or p-xylene binary mixtures have been measured over the entire composition range at 308.15?K. The speed of sound data were used to determine the excess isentropic compressibilities. It is observed that while the values of the excess molar enthalpies for the investigated mixtures are positive, the values of the excess molar volumes and excess isentropic compressibilities are negative over the entire composition range. The measured thermodynamic data have been analyzed in terms of Graph, Prigogine?CFlory?CPatterson, and the Sanchez and Lacombe theories. It is observed that Graph theory correctly predicts the signs and magnitudes of the excess molar volumes, excess molar enthalpies, and excess isentropic compressibilities of the studied mixtures. However, the excess molar volumes, excess molar enthalpies and excess isentropic compressibilities predicted by Prigogine?CFlory?CPatterson and Sanchez and Lacombe theories are of same sign.     

Effects of the Presence of Cyclohexane or Methylcyclohexane on the Densities and Volumetric Properties of the Mixture (Benzene + Propionitrile)

Excess molar volumes, V_m^E, have been obtained as a function of composition for ternary-pseudobinary mixtures of [(benzene + cyclohexane or methylcyclohexane) + (propionitrile + cyclohexane or methylcyclohexane)] from the densities measured by means of a vibrating-tube densimeter at atmospheric pressure and a temperature of 298.15 K. The values of V_m^E have been correlated using the Redlich–Kister equation to estimate the coefficients and standard errors. The experimental and calculated quantities are used to discuss the mixing behavior of the components. The results show that the third component, cyclohexane or methylcyclohexane, has a significant effect on the interaction between benzene and propionitrile.     

Excess Enthalpies of 2,2-Dimethylbutane + Cyclohexane + (Octane or Dodecane) at 25°C

Measurements of excess molar enthalpies at 25°C in a flow microcalorimeter,are reported for the two ternary mixtures 2,2-dimethylbutane + cyclohexane +n-octane and 2,2-dimethylbutane + cyclohexane + n-dodecane. Smoothrepresentations of the results are described and used to construct constant enthalpy contourson Roozeboom diagrams. It is shown that useful estimates of the ternary enthalpiescan be obtained from the Flory theory using only the physical properties of thecomponents and their binary mixtures.     

Excess enthalpies of binary solvent mixtures of 1-butanol and 2-methyl-2-propanol with aniline,N-methylaniline,and N,N-dimethylaniline

The excess molar enthalpies of binary solvent mixtures of 1-butanol and 2-methyl-2-propanol with aniline, N-methylaniline, and N,N-dimethylaniline were measured with a flow microcalorimeter at 40°C. The excess enthalpies are positive for all the systems, and smaller for the mixtures of 1-butanol than the corresponding mixtures of 2-methyl-2-propanol. With respect to the anilines, the values increase in the order aniline < N-methylaniline < N,N-dimethylaniline.