Molar heat capacity of binary liquid mixtures: 1,2-dichloroethane + cyclohexane and 1,2-dichloroethane + methylcyclohexane

The molar heat capacity at constant pressure, C_P, of the two binary liquid mixtures 1,2-dichloroethane + cyclohexane and 1,2-dichloroethane + methylcyclohexane were determined at 298.15 K from measurements of the volumetric heat capacity, C_P/V, in a Picker flow microcalorimeter (V is the molar volume). For the molar excess heat capacity, C_P^E, the imprecision of the adopted stepwise procedure is characterized by a standard deviation of about ± 0.05 J K^?1 mole^?1, which amounts to ca. 3% of C_P^E. Literature data on ultrasonic velocities, on molar volumes, and on coefficients of thermal expansion were used to calculate the molar heat capacity at constant volume, C_v, and the isothermal compressibility, β_T, of the pure substances, as well as the corresponding excess quantities C_V^E and (Vβ_T)^E of the binary mixture 1,2-dichloroethane + cyclohexane. A preliminary discussion of our results in terms of external and internal rotational behavior (trans-gauche equilibrium of 1,2-dichloroethane) is presented.     

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.     

Densities,refractive indices,and derived excess properties of the binary systems tert-butyl alcohol+toluene, +methylcyclohexane,and +isooctane and toluene+methylcyclohexane,and the ternary system tert-butyl alcohol+toluene+methylcyclohexane at 298.15 K

This paper reports experimental densities and refractive indices of the binary systems tert-butyl alcohol (TBA)+toluene, +isooctane, and +methylcyclohexane, and toluene+methylcyclohexane, and the ternary system TBA+toluene+methylcyclohexane, over the entire range of composition at 298.15 K. Excess molar volumes and changes of refractive indices were evaluated from the experimental data obtained. These derived properties were fitted to variable-degree polynomials. The experimental values of physical properties were compared with the values estimated by different methods of prediction.     

Enthalpies of mixing of isopropyl ether with cyclohexane,benzene, toluene,ethylbenzene, p-xylene and mesitylene at 27°C

Enthalpies of mixing of isopropyl ether with cyclohexane, benzene, mesitylene, ethylbenzene, toluene and p-xylene were determined at 27°C and were found to decrease in the same order as the second components listed. The results are compared with Flory's state theory.     

Excess volumes and excess enthalpies of cyclohexanone with alkanes,benzene, toluene and tetrachloromethane at 298.15 K

Excess volumes and excess enthalpies have been measured for binary liquid mixtures of cyclohexanone with n-hexane, n-heptane, 2,2,4-trimethylpentane, benzene toluene and tetrachloromethane at 298.15 K. The results have been discussed in terms of the difference in molecular shape and specific interactions between unlike molecules. The Prigogine—Patterson—Flory equation of state theory has been used to evaluate the free volume and interactional contributions of the excess properties, and to predict excess volumes and excess enthalpies. The calculated values of V^E and H^E are in qualitative agreement with the experimental data in all the systems.     

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.     

The excess volumes of bicyclohexyl+cyclohexane, + cycloheptane,and + cyclooctane at three different temperatures

The excess volumes of bicyclohexyl + cyclohexane, + cycloheptane, and + cyclooctane have been measured over the whole composition range at 288.15, 298.15, and 308.15 K.     

The excess volumes of decahydronaphthalene + cyclopentane, + cyclohexane, + cycloheptane and + cyclooctane at two temperatures

The excess volumes of decahydronaphthalene (decalin) + cyclopentane, + cyclohexane, + cycloheptane and + cyclooctane have been measured over the whole composition range at two temperatures. These measurements show many similarities to the V_m^E results of bicyclohexyl + a cycloalkane and 1,2,3,4-tetrahydronaphthalene (tetralin) + a cycloalkane.     

Excess volumes for binary liquid mixtures of methylethylketone with methylene chloride, 1,2-dichloroethane, trichloroethylene, tetrachloroethylene and cyclohexane at various temperatures

Dilatometric measurements of excess volumes V^E have been made for binary liquid mixtures of methylethylketone with methylene chloride (CH₂Cl₂), 1,2-dichloroethane (CH₂ClCH₂Cl) and tetrachloroethylene (CCl₂CCl₂) at 293.15 and 303.15 K, for mixtures of methylethylketone with trichloroethylene (CHClCCl₂) at 298.15 and 308.15 K, and for mixtures of methylethylketone with cyclohexane (c-C₆H₁₂) at 303.15 K. The values of V^E have been found to be highly positive for methylethylketone + c-C₆H₁₂, slightly positive for methylethylketone + CH₂Cl₂ and methylethylketone + CCl₂CCl₂, and slightly negative for methylethylketone + CHClCCl₂ and methylethylketone + CH₂ClCH₂Cl. The results indicate the existence of specific interactions of methylethylketone with CH₂Cl₂, CH₂ClCH₂Cl, CHClCCl₂ and CCl₂CCl₂.     

Thermodynamics of binary mixtures: excess volumes of mixing of some binary 1,2-dichloroethane mixtures

The excess volumes, V^E, of some binary 1,2-dichloroethane mixtures have been determined at 30°C. The data have been examined for Cell model theory of Prigogine and Flory's theory. Both theories have been found to fail to fit the results with useful accuracy.     

Vapor-liquid equilibria for binary mixtures of carbon dioxide with benzene,toluene and p-xylene

Vapor-liquid equilibrium data for carbon dioxide - benzene, carbon dioxide - toluene, and carbon dioxide - p-xylene were measured for pressures up to 6.5 MPa, and at temperatures of 353 K, 373 K, and 393 K. The solubility of benzene in the dense carbon dioxide vapor phase is higher than that of either toluene or p-xylene. In the liquid phase, carbon dioxide is more soluble in p-xylene than in toluene or benzene. The experimental data obtained were compared with calculations from three correlations: the Peng-Robinson equation, the UNIFAC activity coefficient correlation, and the Perturbed-Anisotropic- Chain Theory (PACT). All three correlations predict phase compositions in good agreement with the experimental data.     

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.     

Adsorption of benzene,toluene, ethylbenzene and p-xylene by NaOCl-oxidized carbon nanotubes

Multiwalled carbon nanotubes (CNTs) were oxidized by sodium hypochlorite (NaOCl) solution and were employed as adsorbents to study their characterizations and adsorption performance of benzene, toluene, ethylbenzene and p-xylene (abbreviated as BTEX) in an aqueous solution. The physicochemical properties of CNTs such as purity, structure and surface nature were greatly improved after oxidation, which significantly enhanced BTEX adsorption capacity. The adsorption capacity of CNT(NaOCl) increased with contact time and initial adsorbate concentration, but changed insignificantly with solution ionic strength and pH. A comparative study on the BTEX adsorption revealed that the CNT(NaOCl) had better BTEX adsorption as compared to CNTs and granular activated carbon. This suggests that the CNT(NaOCl) are efficient BTEX adsorbents and that they possess good potential for BTEX removal in wastewater treatment.     

Density,excess molar volumes and refractive indices of β-pinene with o,m, p-xylene and toluene at 303.15, 308.15 and 313.15 K

Densities (ρ), excess molar volumes (V^E ), refractive indices (n_D ) and deviation in refractive (Δn_D ) indices on mixing for β-pinene with o-xylene, m-xylene, p-xylene and toluene have been determined at T?=?303.15, 308.15 and 313.15?K. The excess molar volume and deviation in refractive index have been fitted to Redlich–Kister polynomials. In addition, deviations in refractive indices were compared with the predictions of several mixing rules. Results obtained have been discussed in terms of intermolecular interactions.     

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.