Isentropic Compressibility Changes Research Articles

Mixing properties of isopropyl acetate+aromatic hydrocarbons at 298.15 K: Density, refractive index and isentropic compressibility

We present new experimental data of density, refractive index and speed of sound for the binaries of isopropyl acetate+(toluene, ethylbenzene, p-xylene, mesitylene, isopropylbenzene, butylbenzene, isobutylbenzene, or t-butylbenzene) at T=298.15 K. and standard conditions, and the corresponding computed derived magnitudes (change of isentropic compressibility, change of refractive index on mixing, and excess molar volume). The mixtures show a clear expansive tendency for the highest molar weight compounds and the steric hindrance role of the aromatic chemicals being analyzed to the light of the non-ideality on mixing. A good agreement among experimental data and the values estimated by theoretical procedures was obtained.

Ultrasonic velocity measurements for the ternary mixtures chlorobenzene + n-hexane + linear aliphatic alkane (C7–C8) at 298.15 K

The ultrasonic velocity of the ternary mixtures chlorobenzene + n-hexane + (n-heptane or n-octane) at 298.15 K and atmospheric pressure, has been measured over the whole concentration range. The corresponding change of isentropic compressibility was computed from the experimental data. The results were fitted by means of the Nagata equation, such parameters being gathered. The experimental ultrasonic velocities have been analyzed by theoretical procedures, an adequate agreement between the experimental and theoretical values both in magnitude and sign being obtained, despite the high nonideal trend of mixtures.

Densities, speed of sound and isentropic compressibilities of the ternary mixture 2-propanol+acetone+cyclohexane and the constituent binary mixtures at 298.15 and 313.15 K

The isentropic compressibilities, speed of sound deviations and changes of isentropic compressibilities of the ternary system 2-propanol+acetone+cyclohexane and the corresponding binary mixtures 2-propanol+acetone, 2-propanol+cyclohexane and acetone+cyclohexane have been evaluated from experimental densities and speed of sound in the complete composition range at 298.15 and 313.15 K. These properties are used to discuss the nature and the extent of intermolecular interaction in the ternary and the constituent binary mixture. Speed of sound deviations, Δ u, changes of isentropic compressibilities, δκ s, have been calculated and fitted by the Redlich–Kister equation for the binary mixtures, while the equation of Cibulka was used to fit the values related to the ternary system. Speed of sound and isentropic compressibilities have been compared with calculated values from free length theory (FLT), collision factor theory (CFT), Nomoto’s relation (NR), Van Deal’s ideal mixing relation (IMR) and Junjie’s relation (JR).

A thermodynamic study on binary and ternary mixtures of acetonitrile, water and butyl acetate

New thermophysical properties are presented for the acetonitrile+water+butyl acetate ternary system and its binary constituents. Molar volume, molar refraction and isentropic compressibility changes of mixing were determined at 298.15 K and correlated with the Redlich–Kister polynomial. Isobaric vapour–liquid equilibria at 101.32 kPa were determined using a dynamic equilibrium apparatus. All systems verify the thermodynamic consistency and data were adequately correlated using Wilson, NRTL and UNIQUAC equations. Finally, the reliability of some group contribution methods, such as ASOG and UNIFAC, was tested by comparison with experimental results.

Analysis of temperature dependence of some physical properties of (n-nonane + tetraethylene glycol dimethyl ether)

In this work, experimental values of densities, refractive indices and speeds of sound for (n -nonane + tetraethylene glycol dimethyl ether (tetraglyme)) at temperatures from 288.15 K to 308.15 K and atmospheric pressure are presented as a function of mole fraction. The corresponding derived properties excess molar volumes, changes of refractive index, changes of speed of sound and changes of isentropic compressibilities on mixing were computed and variable-degree polynomials in mole fraction have been fitted to these results. Different mixing rules were applied in order to predict the refractive indices. The predictions are better when the volume change on mixing is considered. The binodal tie lines for the mixture at different temperatures were determined by the measurement of density and application of the corresponding fitting polynomials. The UNIQUAC method was applied to predict this (liquid + liquid) equilibrium.

Temperature dependence of thermophysical properties of octane+1-butanol system

The aim of this work is to complete our studies on physical properties of binary mixtures of alkane+1-alkanols. This work reports densities, refractive indices, speeds of sound and isentropic compressibilities of the mixture octane + 1-butanol at different temperatures, from 288.15 to 308.15 K. From the experimental values, the corresponding excess and deviation values were computed (excess molar volumes, changes of refractive index on mixing, changes of speed of sound on mixing and changes of isentropic compressibilities on mixing). The results were fitted to variable-degree polynomials. Excess molar volumes were compared with the predictions of Nitta-Chao Group Contribution Model.

Excess Molar Volumes, Viscosity Deviations, and Isentropic Compressibility Changes in Binary Mixtures of N-Methylacetamide + 2-Methoxyethanol and N-Methylacetamide + Water at (308.15, 313.15, and 318.15) K

Densities, viscosities, and ultrasonic velocities of the binary mixtures of N-methylacetamide + 2-methoxyethanol and + water have been measured at (308.15, 313.15, and 318.15) K. The excess molar volumes, viscosity deviations, and isentropic compressibility changes of the mixture from the ideal mole fraction rule have been calculated from these data. The computed results have been fitted to the Redlich−Kister polynomial.

Excess molar volumes, and changes of isentropic compressibilities of ternary { acetone + methanol + ( 2-methyl-1-propanol, or 3-methyl-1-butanol)} at T = 298.15 K

The speed of sound, and density of the ternary {acetone + methanol + (2-methyl-1-propanol, or 3-methyl-1-butanol)} were measured at T= 298.15 K, and atmospheric pressure. The experimental measurements allowed the calculation of the corresponding derived properties, as well as the analysis of the dependence of the compressibility solvation numbers as a function of concentration. The values of the physical properties were compared with the results obtained by different estimative methods. The role of the branched alcohols in separation distillation sequences for (acetone + methanol) is discussed in the light of the thermodynamic measurements obtained.

Thermophysical properties for 1-butanol+ethanol+2-methoxy-2-methylbutane ternary system

In this work some thermophysical properties: molar volume, molar refraction and isentropic compressibility changes of mixing at 298.15 K and isobaric vapour–liquid equilibrium at 101.32 kPa, were determined for the 1-butanol+ethanol+2-methoxy-2-methylbutane system. Several equations were applied to correlate and to predict the experimental values. With data obtained from previous works and these we have drawn several general conclusions about the prediction of these properties for alkanol+alkanol+ether ternary systems.

Temperature Dependence of Thermophysical Properties of Hexane + 1-Hexanol

The aim of this work is to complete our studies on physical properties of binary mixtures of alkane + 1-alkanols. This work reports densities, refractive indices, speeds of sound, and isentropic compressibilities of the mixture of hexane with 1-hexanol at different temperatures, from 288.15 K to 308.15 K. From the experimental values, the corresponding excess and deviation values were computed (excess molar volumes, changes of refractive index upon mixing, changes of speed of sound upon mixing, and changes of isentropic compressibilities upon mixing). Variable-degree polynomials were fitted to the results. A comparative study of these results with other available physical properties of the same mixture was performed. Excess molar volumes were compared with the predictions of the Nitta−Chao Group contribution model.

Densities, Speeds of Sound, Refractive Indices, and the Corresponding Changes of Mixing at 25 °C and Atmospheric Pressure for Systems Composed by Ethyl Acetate, Hexane, and Acetone

Densities, speeds of sound, and refractive indices of the ternary system composed of ethyl acetate, hexane, and acetone and the binary combinations of these constituents have been measured. The excess molar volumes and isentropic compressibility and molar refraction changes of mixing were calculated and correlated using the Redlich−Kister expression.

Density, speed of sound, refractive index and dielectric permittivity of (diethyl carbonate + n -decane) at several temperatures

Density, speed of sound and refractive index values of (diethyl carbonate +n -decane), were measured at the temperatures (288.15, 293.15, 298.15, and 308.15) K and atmospheric pressure. In addition, dielectric permittivities have been measured for the same mixture and at the same temperatures except at T= 293.15 K. Excess molar volumes, changes of isentropic compressibility on mixing, changes of refractive index on mixing and changes of dielectric permittivity on mixing were computed from the experimental data. The excess molar volumes were compared with predictions from the Nitta–Chao model.

Property Changes of Mixing for the 1-Butanol + Methanol + 2-Methoxy-2-methylbutane System at 298.15 K and Atmospheric Pressure

Densities, refractive indices, and speeds of sound at 298.15 K and atmospheric pressure for the 1-butanol + methanol + 2-methoxy-2-methylbutane ternary system have been measured. Excess molar volumes, molar refraction, and isentropic compressibility changes of mixing were determined from experimental measurements. The results were fitted to the Redlich−Kister equation to obtain the coefficients. These property changes were also predicted using several empirical equations from the values of their constituent binary subsystems, and the best results were obtained with the Kohler equation.

Thermodynamic properties of mixing for (1-alkanol + an-alkane + a cyclic alkane) atT = 298.15 K. I. (n-Hexane + cyclohexane + 1-butanol)

Experimental values of density, refractive index and speed of sound of (hexane + cyclohexane + 1-butanol) were measured at T= 298.15 K and atmospheric pressure. From the experimental data, the corresponding derived properties (excess molar volumes, changes of refractive index on mixing and changes of isentropic compressibility) were computed. Such derived values were correlated using several polynomial equations. Several empirical methods were used in the calculation of the properties of ternary systems from binary data. The Nitta–Chao group contribution model was applied to predict excess molar volume for this mixture.

Derived Properties of Binary Mixtures Containing (Acetone or Methanol) + Hydroxil Compounds

This work reports values of the density, refractive index and speed of sound of the binary mixtures acetone or methanol with (2-methyl, 1-propanol, 3-methyl, 1-butanol, 1,2-ethanediol, 1,2-propanediol and 1,3-propanediol) at 298.15 K and atmosphere, as a function of the mole fraction. From the experimental values, the corresponding excess and derived magnitudes were computed (excess molar volumes, changes of refractive index on mixing and changes of isentropic compressibility on mixing), variable-degree polynomials being fitted to the results. Only expansive trend was observed for those mixtures enclosing branched alcohols. The influence of the hydroxil group in the nonideal behaviour of these mixtures were analyzed in terms of the partial molar excess volumes.

Thermodynamic Properties of the Mixture Acetone + Methanol + n-Octane at 25°C

Mixing properties of the ternary mixture acetone + methanol + n-octane have been determined experimentally under standard conditions. Sound velocity, densities, and refractive indexes were measured as functions of composition. Excess molar volumes, changes of refractive indexes, and changes of isentropic compressibilities on mixing were computed from the experimental data. The Peng–Robinson and Soave–Redlich–Kwong equations of state were applied with three different mixing rules to correlate binary excess volumes and then to predict the excess magnitudes in ternary mixtures. Reliable representations of the experimental data were obtained.

Thermodynamic properties of the system (acetone + methanol + n -heptane) atT = 298.15 K

Excess molar volumes, changes of refractive indices, and changes of isentropic compressibilities of the ternary mixture (acetone + methanol +n -heptane) have been computed from density, refractive index, and speed of sound measurements at T= 298.15 K and atmospheric pressure. These derived properties were fitted to the Nagata equation and the correlation parameters determined. Despite the high non-ideality observed, the excess molar volumes were predicted by means of cubic equations of state with simple mixing rules.

Mixing properties of benzene+2-methyl-2-butanol+1-pentanol at 298.15 K. Experimental results and comparison between ERAS model and cubic EOS estimations for excess molar volumes

Excess molar volumes, changes of refractive indices, and changes of isentropic compressibilities of the ternary mixture benzene+2-methyl-2-butanol+1-pentanol, and the binary subsystem 2-methyl-2-butanol+1-pentanol have been calculated from density, refractive index, and speed of sound measurements at 298.15 K and atmospheric pressure. The Redlich–Kister and the Cibulka equation were used for correlating binary and ternary properties, respectively. ERAS model interaction parameters of the binary systems concerned were computed. A good representation of the behaviour of the property is obtained. The Soave–Redlich–Kwong and the Peng–Robinson equations of state were applied, in combination with simple mixing rules. Binary parameters were calculated from experimental excess molar volumes, and used to predict the ternary property, yielding lower deviations.

Physical and equilibrium properties of diisopropyl ether+isopropyl alcohol+water system

Molar volume, isentropic compressibility, and molar refraction changes of mixing of the system diisopropyl ether (DIPE)+isopropyl alcohol (IPA)+water were determined at 298.15 K. These deviational properties were satisfactorily correlated with the composition data by means of Redlich–Kister polynomials. Tie line data have been determined at 298.15, 308.15, and 318.15 K for the ternary liquid–liquid equilibria, and were adequately correlated by means of the NRTL and UNIQUAC equation, and compared with results predicted by the UNIFAC method.

Temperature dependence of the thermophysical properties of binary mixtures of n-hexane + 1-butanol

This work reports densities, refractive indices, speeds of sound, and isentropic compressibilities of the mixture of n-hexane with 1-butanol at different temperatures, from 288.15 K to 308.15 K. From the experimental values, the corresponding excess and deviation values were computed (excess molar volumes, changes of refractive index on mixing, changes of speed of sound on mixing, and changes of isentropic compressibilities on mixing). Variable-degree polynomials were fitted to the results. A comparative study of these results with other available physical properties of the same mixture has been performed. Excess molar volumes were compared with the predictions of the Nitta-Chao group contribution model, based on the Carnahan-Starling hard-sphere equation of state.