Density Of Binary Mixtures Research Articles

Excess Molar Volumes and Surface Tensions of Xylene with Acetone or 2-Butanone at 298.15 K

Densities for binary mixtures of (acetone + o-xylene, + m-xylene, and + p-xylene and 2-butanone + o-xylene, + m-xylene, and + p-xylene) have been determined at 298.15 K, and excess molar volumes have been derived. Surface tensions of these binary mixtures have been measured at 298.15 K by the pendant drop method, and the values of the surface tension deviation for these mixtures were also calculated.

Optical and volumetric study of molecular interactions in binary mixtures of tetrahydrofuran with 1-propanol and 2-propanol

The refractive indices and densities of binary mixtures of tetrahydrofuran (THF) with 1-propanol (1-P) and 2-propanol (2-P) over the entire composition range have been measured at 293, 303 and 313 K. Refractive index and density data have been used to evaluate the molar refraction deviation ΔR m and excess molar volume . The values of ΔR m and are negative for THF + 1-P mixture and are positive for THF + 2-P mixture. This suggests that specific interactions are taking place in THF + 1-P mixture while dispersive forces are responsible for behaviour of THF + 2-P mixture.

Volumetric behaviour of binary liquid mixtures of 2-methoxyethanol with n-butylamine, sec-butylamine and tert-butylamine

Densities of binary mixtures containing 2-methoxyethanol with n -butylamine, sec -butylamine and tert -butylamine have been determined at different temperatures, between 291.15 and 313.15 K, over the complete concentration range. Excess molar volumes were calculated and the departure from ideal behaviour is explained on the basis of specific interactions between the components in these mixtures.

Volumetric behaviour of binary liquid mixtures of 2-methoxyethanol with n-butylamine, sec-butylamine and tert-butylamine

Densities of binary mixtures containing 2-methoxyethanol with n-butylamine, sec-butylamine and tert-butylamine have been determined at different temperatures, between 291.15 and 313.15 K, over the complete concentration range. Excess molar volumes were calculated and the departure from ideal behaviour is explained on the basis of specific interactions between the components in these mixtures.

Temperature studies of dielectric permittivity and mass density pretransitional anomalies in binary mixtures

Results of temperature studies of dielectric permittivity and mass density in binary mixtures are presented. The anomaly of dielectric permittivity as a function of temperature in nitrobenzene-n-alkanes binary mixtures has been studied. Molar dielectric permittivity which takes into account the anomaly of dielectric permittivity and the mass density anomaly has been introduced.

Liquid densities for binary mixtures of difluoromethane and pentafluoroethane

A new high-pressure densimeter which employs the direct weighing technique was constructed to measure compressed liquid density. The reliability of the apparatus was confirmed by comparing the measurements for pure fluids with reference data. The compressed liquid densities for binary mixtures of difluoromethane and pentafluoroethane were measured in the range 283-333K and near the saturation line up to about 20MPa. It was found that these results were in fair agreement within ±0.3% taking into account the estimation errors of temperature, pressure, and composition with the reference data in the high density region.

Nuclear Magnetic Shielding and Spin−Spin Coupling of 1,2-13C-Enriched Acetylene in Gaseous Mixtures with Xenon and Carbon Dioxide

13C and 1H NMR spectra have been measured for 1,2-13C-acetylene at low density in binary mixtures with xenon and carbon dioxide gases as the solvents. It was found that both the chemical shifts and the 1J(CC) coupling constant of 13C2H2 were linearly dependent on the solvent density. The appropriate NMR parameters for an isolated 13C2H2 molecule were determined, together with the coefficients responsible for the solute−solvent molecular interactions. The 13C NMR measurements were extended to solutions of 1,2-13C-acetylene in liquid solvents. All of the 13C gas-to-solution shifts were found to be positive (deshielding effects), and the 1J(CC) coupling constant in liquid acetone was diminished by more than 5% in comparison with the value of 174.78 Hz observed in the gas phase.

Group contributions to the infinite dilution partial molar volumes of alkanes, alcohols, and glycols in polar organic solvents

Densities of binary mixtures of polar organic solvents with alcohols were measured at 25‡C. The solvents studied were N,N-dimethylformamide, dimethylsulfoxide, and formamide while alcohols were butanol, pentanol, hexanol, and 1,4-butanediol. Density measurements of hydrocarbons (from pentane to dodecane and some heptane isomers) + N,N-dimethylformamide were also performed. From these data the apparent molar volumes of alcohols and hydrocarbons as functions of concentration were calculated. The standard partial molar volumes were obtained by extrapolation to infinite dilution and are discussed in terms of group contributions.

A simple model for size non-additive mixtures

A simple and general mixture model based on the exact third virial coefficient of a non-additive hard spheres mixture has been developed. It reproduces the correct composition dependence of all virial coefficients. The new model, together with a model proposed recently, was tested by comparing the prediction of fourth virial coefficients with the exact values. More extensive tests of these models were performed at high densities by comparing their predictions of compressibility factors, for mixtures of additive hard spheres, non-additive hard spheres and Lennard-Jones molecules, with simulation data. For real molecules, predictions of molar densities of binary mixtures of argon and krypton and of carbon dioxide and ethane were compared with experimental data. The two models are more accurate than the van der Waals one-fluid model. One is even more accurate than the Weeks–Chandler–Andersen–Lee–Levesque–Grundke–Henderson (WCA–LL–GH) perturbation theory model. Application of the new models to real mixtures shows the importance of including size non-additivity in mixture models.

Viscosities and thermodynamics of viscous flow of binary liquid mixtures of 2-(2-butoxyethoxy)ethanol with aniline and N-alkyl anilines

Viscosities and densities of binary mixtures containing 2-(2-butoxyethoxy)ethanol with aniline and N-alkyl-substituted anilines have been determined at five different temperatures over the complete concentration range. Excess volumes, viscosities, and excess molar free energy of activation of flow were calculated and the departure from ideal behavior is explained on the basis of specific interactions between the components in these mixtures. McAllister's approach correlates the viscosity data with a significantly high degree of accuracy for all these systems.

Viscometric and Density Study of Binary Mixtures of 2,2,2-Trifluoroethanol with Anilines

Abstract Viscosity coefficients and densities of binary mixtures of 2,2,2-trifluoroethanol with aniline and N-alkylanilines have been measured at five temperatures over the entire composition range. From the experimental data, excess volumes, viscosities and free energies of activation values were calculated and discussed in terms of intermolecular interactions between the components in the binary mixtures. Semiempirical equations of McAllister and Heric were employed to fit the experimental viscosity of the binary mixtures.

Ultrasonic studies on binary mixtures of associated liquids (1-bromobutane+alcohol) at 303·15K

Ultrasonic sound velocities and densities of binary mixtures of 1-bromobutane with propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol, heptan-1-ol and octan-l-ol have been experimentally determined at 303·15 K. Isentropic compressibilities (K s) and deviations in isentropic compressibilities (ΔK S) have been calculated from the results. The values of ΔKS are almost positive over the entire range of composition in all six binary liquid mixtures. The experimental results are explained in terms of depolymerisation of hydrogen-bonded alcohol aggregates, decrease in dipolar association and weak hydrogen-bonding interaction of the type Br---H-O between unlike molecules.

Viscosities and Densities of Binary-Mixtures of 2,2,2-Trichloroethanol With Substituted Anilines

Densities and viscosities of binary solvent mixtures containing 2,2,2-trichloroethanol as one component and aniline and substituted anilines as the other components have been measured over the whole composition range at 298, 303, 308, 313 and 318 K. The experimental data are fitted to a semitheoretical equation of McAllister. Excess viscosity, volume and Gibbs energy of activation of flow have been evaluated, and the departure from ideal behaviour is explained on the basis of specific interactions between the components of this mixture.

Vapor-liquid equilibrium of near-critical binary alkane mixtures

The modified Leung-Griffiths model of Rainwater and Moldover is used to correlate vapor-liquid equilibrium (VLE) surfaces in pressure, temperature, and density for binary mixtures in the near-critical region. The systems studied are butane-pentane, propane-isopentane, butane-hexane, and ethane-butane. The model, which has also successfully fit several other mixtures, is based on scaling-law equations of state expressed in terms of field variables. It incorporates a variation of the principle of corresponding states as well as the coupling of density and composition change across the phase boundary. As the width of the dew-bubble curves increases, additional parameters are required to obtain successful VLE correlations.

The adsorption of prothrombin to phosphatidylserine multilayers quantitated by ellipsometry.

We investigated by means of an automated ellipsometer the adsorption of prothrombin from a buffer solution by multilayers of 14:0/14:0- and 18:1/18:1-phosphatidylserine (PS) stacked on chromium slides. In this instrument thickness and refractive index of the adsorbed phospholipid and proteins are monitored continuously. Two equations are derived to relate the mass of stacked phospholipids and the mass of protein adsorbed to the thickness and refractive index. These equations are based upon the Lorentz-Lorenz relation among the molar refractivities, refractive indices, and the densities of binary mixtures. Experimental validation of these equations is performed by measuring stacked multilayers of known mass of phosphatidylserine and the adsorption of [125I] albumin and [3H]prothrombin on these multilayers. Using these equations we measured the dissociation constants Kd and the number of binding sites nb of prothrombin. Values of Kd = 0.15 x 10(-8) M and nb = 122 molecules of PS/molecule of prothrombin were observed for di C14:0 PS and values of Kd = 0.45 x 10(-8) M and nb = 54 molecules of PS/molecule of prothrombin for di C18:1 PS. These data compare well to data obtained by other methods available in the literature.

Rectilinear diameter for saturated densities of binary mixtures

Rectilinear diameter for saturated densities of binary mixtures

Densities and molar volumes for the molten salt systems ZnBr2 + KBr, CdI2 + NaI and CdI2 + CsI

Densities of binary mixtures of ZnBr2 + KBr, CdI2 + NaI and CdI2 + CsI, have been measured by an Archimedian method over a wide range of temperature. Results have been expressed in terms of simple linear equations in temperature. Molar volumes for the systems have excess values in the ZnBr2 + KBr and CdI2 + CsI systems but not to such an extent in the CdI2+NaI system. The excess molar volumes are related to the possible formation of complex ions in the systems concerned.