Liquid-liquid equilibria of (cyclohexane + acetonitrile + methylcyclohexane + toluene) and of {(acetonitrile + methylcyclohexane) + benzene or + toluene or + cyclohexane or + chlorobenzene} at 298.15 K

Tie-line results at 298.15 K and atmospheric pressure are reported for (cyclohexane + acetonitrile + methylcyclohexane + toluene) and for {(acetonitrile + methylcyclohexane) + benzene or + toluene or + cyclohexane or + chlorobenzene). The extended UNIQUAC and UNIQUAC equations are used to correlate binary vapour-liquid equilibria and mutual solubilities for 10 mixtures constituting the ternary mixtures and to predict the ternary and quaternary liquid-liquid equilibria by use of only binary parameters.     

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 volumes of methylcyclohexane+benzene, +methylbenzene, +1,4-dioxane,and +tetrahydrofuran at 303.15 K

Excess molar volumes V_m^E as function of mole fraction x for methylcyclohexane + benzene, + methylbenzene, + 1,4-dioxane, and + tetrahydrofuran are reported at 303.15 K. The excess molar volumes are positive and indicate the presence of weak interactions.     

Frequency response study of the dynamics of the platinum catalyzed interconversion of methylcyclohexane, toluene, and hydrogen near equilibrium

The dynamics of the platinum catalyzed interconversion of methylcyclohexane, toluene, and hydrogen near equilibrium were investigated in a closed reactor system by a frequency response method at temperatures in the range of 433 to 473 K and at total pressures in the vicinity of 80 to 110 Torr. The gas phase in contact with the platinum catalyst was always hydrogen-rich, with hydrogen to hydrocarbon mole ratios maintained in the range of 3.2 to 4.6. The frequency response method utilized small perturbations (lower than 1%) of the volume of the system, with measurements of the total pressure being used to determine the response of the system. The range of perturbation frequencies investigated was approximately 0.002 to 3 Hz (0.013 to 19 rad s(-1)). The experiments revealed two characteristic relaxation frequencies that are associated with the dynamics of the interconversion. The dynamics of the system are interpreted in terms of a simple two-step interconversion sequence with the aid of a phenomenological frequency response theory formulated in terms of relaxation frequencies of the steps and equilibrium properties of the system. It is concluded that one of the steps, a toluene adsorption-desorption step, is much slower than the other, a step involving the interconversion of the gas-phase methylcyclohexane and chemisorbed toluene that releases or consumes hydrogen in the process.     

Solubilities of benzene, toluene and diphenyl in the t-butyl alcohol+water mixtures and hydrophobic interaction

The solubilitices of benzene, toluene and diphenyl in mixed solvents of t-butyl alcohol (TBA) and water at 283.15, 288.15, 293.15 and 298.15 K have been determined by spectrophotometry. The mole fraction of TBA [x (TBA)] in the mixed solvent are 0.000, 0.010, 0.020, 0.030, 0.040, 0.045, 0.050, 0.060, 0.080 and 0.100, respectively. The standard Gibbs energies of solution of benzene, toluene and diphenyl in the mixed solvent have also been calculated based on the solubility data. The hydrophobic interactions (HI) for the pairs of benzene-benzene, methane-benzene and methane-methane in the mixed solvent were calculated and discussed.     

Binary gaseous diffusion coefficients,III: Sulfur hexafluoride with cyclohexane,methylcyclohexane and toluene at 1 atm pressure and 10–70°C

The binary gaseous diffusion coefficients at 1 atm pressure of sulfur hexafluoride with cyclohexane, methylcyclohexane, benzene, and toluene were measured at 10, 25, 40, 55 and 70°C by the capillary tube method ofStefan ¹. Diffusion coefficients were calculated (a) by usingLennard-Jones (6, 12) pair potential parameters in conjunction with theHudson-McCoubrey combining rule², and (b) with a semiempirical method somewhat similar to that suggested bychen andOthmer ³. Diffusion coefficients calculated via method (b) were in much better agreement with experiment than those obtained via method (a).     

Excess properties of binary mixtures hexane,heptane, octane and nonane with benzene,toluene and ethylbenzene at T = 283.15 and 298.15 K

Densities, speeds of sound and the refractive indices of binary systems containing alkanes (hexane, heptane, octane and nonane) with aromatic compounds (benzene, toluene and ethylbenzene) at T = 283.15 and 298.15 K under atmospheric pressure were determined over the whole composition range. From the experimental results, the derived and excess properties (excess molar volumes, isentropic compressibility, excess molar isentropic compressibility and refractive index deviations) at T = 283.15 and 298.15 K were calculated and satisfactorily fitted to the Redlich–Kister equation.     

Molar excess enthalpies of cis-decalin + benzene, + toluene, +isooctane and +heptane at 298.15 K

Molar excess enthalpies H^E of cis-decalin + benzene, +toluene, +isooctane and +heptane mixtures have been measured by an LKB flow microcalorimeter at 298.15 K. The experimental results are analyzed using the Flory-Patterson-Prigogine theory. The isomer effect of decalin molecule and the effect of the molecular size and shape of the component molecules are discussed.     

Refractive Indices, Viscosities, and Densities for L-Cysteine Hydrochloride Monohydrate + D-Sorbitol + Water, and Glycerol + D-Sorbitol + Water in the Temperature Range between T=303.15 K and T=323.15 K

Viscosities, refractive indices, and densities for ternary systems of (L-cysteine hydrochloride monohydrate [LCHCMH] + D-sorbitol + water) and (glycerol + D-sorbitol + water) and binary systems of ([LCHCMH] + water) and (D-sorbitol + water) have been measured at several temperatures (between T=303.15 K and T=323.15 K) and mass fractions (0.1 to 0.8) at atmospheric pressure. For these mixtures, the experimental values of density were correlated with an experimental equation and the experimental values of viscosity were correlated with the Jones-Dole equation.     

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.     

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.     

(Liquid + liquid) phase behavior for systems containing (aromatic + TBA + methylcyclohexane)

The determination region of solubility of TBA (tert-butanol) with representative compounds of the gasoline was investigated experimentally at temperature of 298.2 K. Type 1 (liquid + liquid) phase diagrams were obtained for (methylcyclohexane + TBA + aromatic compounds). These results were correlated simultaneously by the UNIQUAC model. The values of the interaction parameters between each pair of components in the systems were obtained for the UNIQUAC model using the experimental result. The root mean square deviation (RMSD) between the observed and calculated mole percents was 1.88 for (methylcyclohexane + TBA + benzene), 2.45 for (methylcyclohexane + TBA + toluene) and 2.86 for (methylcyclohexane + TBA + ethylbenzene). The mutual solubility of methylcyclohexane and aromatic compounds (e.g., benzene toluene and ethylbenzene (BTE)) was also investigated by the addition of TBA at temperature of 298.2 K.     

Optical parameters of thin calixarene films and their response to benzene,toluene and chloroform adsorption

Ellipsometry and surface plasmon-polariton resonance were used to measure both the thickness, d, and refractive index, N, of tert-butylcalix[n]arene (n = 4, 6 and 8) films, as well as the effect of the adsorption of benzene, toluene and chloroform on these parameters. The refractive index values were found to lie in the range 1.56–1.58. Exposure to benzene (chloroform) vapour increased N by 0.01–0.02, while toluene adsorption led to calixarene film swelling (up to 10–12%). Warming the films in air at 160 °C restored the former values of both d and N. Some mechanisms of interaction between the adsorbate molecules and calixarene films are proposed.     

Vapor-liquid equilibria at atmospheric pressure for quinary systems containing n-hexane + ethanol + methylcyclopentane + benzene and either + toluene or + methanol

Values of (p, T, x, y) were determined at 101.325 kPa for each of two quinary systems containing n-hexane + ethanol + methylcyclopentane + benzene and either + toluene or + methanol. The experimental results were compared with those determined from the Wilson equation using parameters obtained from binary results.     

Excess and deviation properties for the binary mixtures of methylcyclohexane with benzene, toluene, p-xylene, mesitylene, and anisole at T = (298.15, 303.15, and 308.15) K

Experimental data on density, viscosity, and refractive index at T = (298.15, 303.15, and 308.15) K, while speed of sound values at T = 298.15 K are presented for the binary mixtures of (methylcyclohexane + benzene), methylbenzene (toluene), 1,4-dimethylbenzene (p-xylene), 1,3,5-trimethylbenzene (mesitylene), and methoxybenzene (anisole). From these data of density, viscosity, and refractive index, the excess molar volume, the deviations in viscosity, molar refraction, speed of sound, and isentropic compressibility have been calculated. The computed values have been fitted to Redlich-Kister polynomial equation to derive the coefficients and estimate the standard errors. Variations in the calculated excess quantities for these mixtures have been studied in terms of molecular interactions between the component liquids and the effects of methyl and methoxy group substitution on benzene ring.     

Excess volumes for trichloroethene + benzene, + toluene, + p-xylene, + tetrachloromethane,and + trichloromethane at 303.15 K

Excess volumes V^E for trichloroethene (CCl₂CHCl) + benzene, + toluene, + p-xylene, + tetrachloromethane, and + trichloromethane have been measured at 303.15 K, by direct dilatometry. V^E has been found to be positive for trichloroethene + benzene, and + trichloromethane, and negative for trichloroethene + toluene, and + p-xylene. For trichloroethene + tetrachloromethane V^E is positive at low mole fractions of C₂HCl₃ and negative at high mole fractions.     

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.     

Acoustical parameters of toluene + chloroform + cyclohexane mixtures at 303.15, 308.15, and 313.15 K

Ultrasonic velocity, density and viscosity of the ternary mixture of toluene + chloroform + cyclohexane, were measured at 303.15, 308.15, and 313.15 K. The thermodynamically parameters such as adiabatic compressibility (??), intermolecular free length (L _f), free volume (V _f), internal pressure (?? _i ), acoustic impedance (Z), molar sound velocity (R), and molar compressibility (W) have been obtained from the experimental data for all the mixtures, with a view to investigate the exact nature of molecular interaction. Adiabatic compressibility and intermolecular free length decrease with increase in concentration and temperature. The other parameters show almost increasing concentration of solutes. These parameters have been further used to interpret the molecular interaction part of the solute and solvent in the mixtures.     

Isobaric (vapour + liquid) equilibria for sulfolane with toluene, ethylbenzene, and isopropylbenzene at 101.33 kPa

Isobaric (vapour + liquid) equilibrium data have been measured for the (toluene + sulfolane), (ethylbenzene + sulfolane), and (isopropylbenzene + sulfolane) binary systems with a modified Rose-Williams still at 101.33 kPa. The experimental data of binary systems were well correlated by the non-random two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) activity coefficient models for the liquid phase. All the experimental results passed the thermodynamic consistency test by the Herington method. Furthermore, the model UNIFAC (Do) group contribution method was used. Sulfolane is treated as a group (TMS), the new group interaction parameters for CH₂–TMS, ACH–TMS and ACCH₂–TMS were regressed from the VLE data of (toluene + sulfolane) and (ethylbenzene + sulfolane) binary systems. Then these group interaction parameters were used to estimate phase equilibrium data of the (isopropylbenzene + sulfolane) binary system. The results showed that the estimated data were in good agreement with the experimental values. The maximum and average absolute deviations of the temperature were 4.50 K and 2.39 K, respectively. The maximum and average absolute deviations for the vapour phase compositions of isopropylbenzene were 0.0237 and 0.0137, respectively.