Solubility of benzil in binary alkane + dibutyl ether solvent mixtures. Comparison of predictive expressions derived from the nearly ideal binary solvent model

Experimental solubilities are reported for benzil dissolved in six binary mixtures containing dibutyl ether with hexane, heptane, octane, cyclohexane, methylcyclohexane, and 2,2,4-trimethylpentane at 25°C. Results of these measurements are compared to the predictions of equations developed previously for solubility in systems of nonspecific interactions. The most successful equation in terms of goodness of fit involved a volume fraction average of the excess Gibbs energies relative to the Flory-Huggins model, and predicted the experimental solubilities in the six systems studied to within an overall average absolute deviation of 3.4% and with a maximum deviation of 6.0%.     

Solubility of anthracene in binary alcohol + 1-pentanol solvent mixtures at 25°C: Comparison of expressions derived from Mobile Order theory and the Kretschmer-Wiebe association model

A relatively simple expression is developed for predicting the solubility of an inert crystalline solute in binary alcohol + alcohol solvent mixtures based upon the Kretschmer-Wiebe association model. The predictive accuracy of the newlyderived expression is compared to equation(s) derived previously from Mobile Order theory using experimental anthracene solubilities in seven binary alcohol + 1-pentanol solvent mixtures at 25°C, which were measured as part of the present investigation. Computations show that both models accurately describe the solubility behavior of anthracene in the binary solvent systems studied. Average absolute deviations between observed and predicted values were 0.9% and 1.4% for the Kretschmer-Wiebe and Mobile Order predictive equations, respectively.     

Solubility of Anthracene in Binary Carbon Tetrachloride + Alkane Solvent Mixtures

Abstract

Experimental solubilities are reported for anthracene in binary solvent mixtures containing carbon tetrachloride with n-hexane, n-heptane, n-octane, cyclohexane, methylcyclohexane and isooctane at 25°C. Results of these measurements, combined with the excess Gibbs free energies of the binary solvents, are used to test predictive expressions derived from the nearly ideal binary solvent (NIBS) model. Expressions based on a volume fraction average of solute properties in the two pure solvents predict anthracene solubilities to within a maximum deviation of 4.5% and an overall average deviation of 1.8%.     

Solubility of polycyclic aromatics in binary solvent mixtures using activity coefficient models

Polycyclic aromatic hydrocarbons (PAHs) precipitation is one of the major problems in the hydrocracking units. In this investigation, pyrene and phenanthrene were selected because they were found to be in higher concentrations in the feed to hydrocracking units. Their solubilities were investigated in toluene solvent mixture of iso-octane and heptane over a temperature range from 293 to 323 K. The experimental solubility data were used to predict the interaction parameters for seven different solid–liquid equilibrium models. The following activity coefficient models were used; Wilson, NIBS/Redlich–Kister, UNIQUAC, modified UNIFAC, modified UNIFAC (Dortmund), Flory–Huggins and Sheng. The interaction parameters were expressed as a second-order polynomial function in temperature. In order to test the models, the average absolute deviation percentage (AADP) was used. The overall AADP was found to range from approximately 7 to 14%. The models can be arranged according to their accuracy in a descending order based on AADP as follows: NIBS/Redlich–Kister, Wilson, UNIQUAC, Sheng, Flory–Huggins, modified UNIFAC (Dortmund) and finally modified UNIFAC. All models used in this work gave reasonable results; however, the group contribution models can also be used as a predictive tool for the solubility measurement of pyrene and phenanthrene in other solvents containing the same groups of the solvents used in this study.     

Solubility of ethane int-butanol + water mixtures and a hydrophobic interaction study

The solubilities of ethane int-butanol (TBA) and water mixtures have been determined at 10, 15, and 20°C and pressures up to 3.1 MPa. Thermodynamic properties have also been calculated based on the measured solubility data and the hydrophobic interaction for the methane-methane pair interaction in the mixed solvent is discussed.     

Solubility prediction of paracetamol in binary and ternary solvent mixtures using Jouyban-Acree model

The Jouyban-Acree model has been used to predict the solubility of paracetamol in water-ethanol-propylene glycol binary and ternary mixtures based on model constants computed using a minimum number of solubility data of the solute in water-ethanol, water-propylene glycol and ethanol-propylene glycol binary mixtures. Three data points from each binary solvent system and solubilities in neat solvents were used to calculate the binary interaction parameters of the model. Then the solubility at other binary solvent compositions as well as in a number of ternary solvents were predicted, and the mean percentage deviation (+/-S.D.) of predicted values from experimental solubilities was 7.4(+/-6.1)%.     

Solubility of 2,5-dimethylphenol and 3,4-dimethylphenol in binary solvent mixtures containing alcohols

Solubilities are reported for 3,4-dimethylphenol and 2,5-dimethylphenol in binary mixtures of ethyl acetate with alcohols (methanol, 1-butanol, 1-hexanol), as well as for 2,5-dimethylphenol in binary mixtures of hexane with 1-butanol. The results of these measurements are compared to those obtained from the predictions by the Wilson equation for the excess Gibbs free energy of mixing (G^E). Parameters in binary solute—solvent systems were regressed from solid—liquid equilibrium data, whereas for binary mixed solvents they were taken from literature data of vapour—liquid equilibrium as well as from solid—liquid equilibrium data in ternary mixtures for equimolar compositions of binary solvents. The systems containing 3,4-dimethylphenol—ethyl acetate+alcohol mixed solvents were found to exhibit a small synergistic effect of solubility.     

Studies on silver(I) solvation in binary solvent mixtures containing dimethylsulfoxide. IV determination of solvent transference numbers for AgSCN and ionic coordination numbers of Ag+ in methanol-dimethylsulfoxide mixtures at 25°C

Solvent transport by AgSCN in the methanol (M)+dimethylsulfoxide (DMSO) system has been studied at 25°C by e.m.f. measurements. The solvent transference number of DMSO is positive as its concentration increases in the cathode compartment during electrolysis. The solubility of AgSCN has been determined in methanol, in DMSO and in methanol-DMSO mixtures. Using the known Gibbs free energy of solvation for the Ag⁺ ion, the corresponding energy for SCN, was found to be independent of the mole fraction. The experimental solvent transference numbers therefore only represent the contribution of Ag⁺, this is because it is preferentially solvated by DMSO. A coordination model has been applied to the Gibbs free energy of transfer of Ag⁺ in order to obtain coordination numbers thereby allowing calculation of solvent transference numbers. The experimental and the calculated solvent transference numbers are in good agreement at mole fractions of DMSO greater than 0.5. In highly methanolic solutions the assumption that the solvation of Ag⁺ in the solvent system studied is adequately represented by a total coordination number of four, proves to be too simple.     

A correlation of gas solubilities and kinetics of hydrolysis in binary aqueous mixtures

A treatment which predicts the solubilities of gases in solvent mixtures is examined in the context of the analysis of kinetic data for reactions in aqueous mixtures. The treatment is qualitatively successful to some extent in resolving the effects of changes in the initial state of the reacting substrate in the activation parameters.     

Prediction of vapor-liquid equilibrium from excess enthalpy data for binary ether +n-alkane or cyclohexane mixtures

Vapor liquid equilibrium (VLE) is successfully predicted from excess enthalpy H^E data for binary ether + n-alkane or cyclohexane mixtures. Parameters for the continuous linear association model (CLAM) and for the UNIQUAC Model for the excess Gibbs energy G^E were determined from H^E data measured at a low temperature (ambient temperature). These parameters are used to predict VLE data at low and high temperatures. The dependence of the accuracy of predictions on the set of H^E data chosen to evaluate the parameters and on the model for G^E are discussed.     

Solubility of trans-Stilbene in Binary Alkane + 2-Propanol Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for trans-stilbene dissolved in six binary alkane + 2-propanol solvent mixtures at 25[ddot]C. The alkane cosolvents studied were hexane, heptane, octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister and Modified Wilson equations. For the six systems studied, both equations provided an accurate mathematical representation of the experimental data, with overall average absolute deviations between measured and calculated values being approximately ± 0.5%.     

Acetonitrile + nitromethane: An example of ideal solvent mixtures

Densities, viscosities, static dielectric constants and refractive indices of acetonitrile + nitromethane mixtures in the temperature range between 5 and 45°C are reported. Density and viscosity data, analyzed in terms of molar excess volumes and molar excess fluidities, show a weak interactions field between acetonitrile and nitromethane molecules. Lorentz-Lorenz molar refractivities and Kirkwood correlation factors, obtained from refractive indices and dielectric constants data, respectively, indicate that such weak interactions can be atributed to an antiparallel alignment between neighboring dipoles of unlike solvent molecules. Such specific features do not significantly perturb the local structures of the pure components so that acetonitrile + nitromethane mixtures can be considered, in a first approximation, one of the few ideal solvent mixtures for which the physical properties can be determined by applying the additivity rules to the pure components.     

Solubility of Trans-Stilbene in Binary Alcohol + 1-Propanol Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for trans-stilbene dissolved in six binary alcohol + 1-propanol solvent mixtures at 25°C. The alcohol cosolvents studied were 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 1-pentanol and 3-methyl-1-butanol. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister and Modified Wilson equations. For the six systems studied, the Combined NIBS/Redlich-Kister equation was found to provide the better mathematical representation of the experimental data, with overall average absolute deviations between measured and calculated values being approximately ±0.4%. Slightly larger deviations were noted in the case of the Modified Wilson equation.     

Solubility of Trans-Stilbene in Binary Alkane + 1-Butanol Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for trans-stilbene dissolved in six binary alkane + 1-butanol solvent mixtures at 25°C. The alkane cosoivents studied were hexane, heptane, octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister and Modified Wilson equations. For the six systems studied, the Combined NIBS/Redlich-Kister equation was found to provide the better mathematical representation of the experimental data, with overall average absolute deviations between measured and calculated values being approximately ±0.6%. Slightly larger deviations were noted in the case of the Modified Wilson equation.     

Solubility of Trans-Stilbene in Binary Alkane + 1-Propanol Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for trans-stilbene dissolved in six binary alkane + 1-propanol solvent mixtures at 25°C. the alkane cosolvents studied were hexane, heptane, octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister and Modified Wilson equations. for the six system studied, the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister equation provided the better mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being approximately 0.4%. Slightly larger deviations were noted in the case of the Modified Wilson equation.     

Electrochemical study of 18-crown-6-Tl+ complexes in binary solvent mixtures

Summary The formation constants,K _S, of the 18-crown-6 complex with thallium(I) ion were studied by polarographic measurements in binary mixtures of acetonitrile, acetone, tetrahydrofuran, and dimethylsulfoxide with water, as a function of the solvent mole fraction. In all the cases, the variation of the stability constant can be described by the empirical relation logK _S=a[(–1)/(2+1)]+b where stands for relative permittivity of a given mixture anda andb mark the regression coefficients. The values ofa calculated for four series of binary mixtures showed correlation with the Gutmann donor numbers of the neat organic solvents which form the mixture.On leave from the Department of Chemistry, Jingzhou Teacher's College, Jingzhou, Hubei, China     

Solubility of Anthracene in Binary Alkane + 2-Ethoxyethanol Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for anthracene dissolved in six binary alkane + 2-ethoxyethanol solvent mixtures at 25°C. the alkane cosolvents studied were hexane, heptane, octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister and Modified Wilson equations. for the six systems studied, the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister equation provided the better mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being approximately 0.4%. Slightly larger deviations were noted in the case of the Modified Wilson equation.     

Solubility of Anthracene in Binary Alcohol + 1-chlorobutane Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for anthracene dissolved in six binary alcohol + 1-chlorobutane solvent mixtures at 25°C. The alcohol cosolvents studied were 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol and 3-methyl-1-butanol. Results of these measurements are used to test a mathematical representation based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister equation. For the six systems studied, the Combined NIBS/Redlich-Kister equation was found to mathematically describe the experimental data, with overall average absolute deviations between measured and calculated values being approximately\pm 0.4%.     

Thermodynamics of molecular interactions in ethyl iodide+toluene mixtures

The excess Gibb's free energy of mixing, G^E, for ethyl iodide+toluene at 25°C have been obtained from the measured vapor pressuure data. The H^E and G^E values for ethyl iodide+toluene are positive throughout the ethyl iodide concentration range and G^E>H^E. The results have been analyzed in terms of Flory and ideal associated model theory of nonelectrolyte solutions. It has been observed that the ideal associated model approach which assumes the presence of AN and A₂B molecular species describes well (within±10 J-mol^–1 in the worst case) the general dependence of H^E on X_A (mole fraction of ethyl iodide) over the whole composition range for ethyl iodide+toluene mixtures. The equilibrium constants for A+A AB and 2A+BA₂B reactions along with the enthalpies of formation of AB and A₂B molecular species have been calculated.