Excess Enthalpies Of Binary Mixtures Research Articles

Excess volumes and excess enthalpies for binary mixtures of methyl methacrylate with cyclopentane and with cyclohexane

Excess volumes and excess enthalpies for binary mixtures of methyl methacrylate with cyclopentane and with cyclohexane

Excess enthalpies of binary mixtures of n-decane with hexane isomers

Excess enthalpies of binary mixtures of n-decane with hexane isomers

Enthalpic McMillan–Mayer coefficients from literature data on excess enthalpies. Application to solutions of alkanes in alkan-1-ols

A method is described to calculate enthalpic McMillan–Mayer pair-interaction coefficients from literature data on excess enthalpies of binary mixtures. The calculation also yields the enthalpies of solution at infinite dilution. A test of the method of mixtures, for which directly measured enthalpic interaction coefficients are known, shows that the method gives results of reasonable accuracy. However, the method is able to obtain a large number of interaction coefficients in a relatively simple manner. This makes interpretation and correlation analyses of the results possible, and this is illustrated by the application of the method to alkane + alkan-1-ol mixtures. Results for alkanes dissolved in alkan-1-ols are discussed in terms of the Savage–Wood group-additivity treatment using one parameter for each solvent. In addition we present an empirical relation which makes it possible to correlate 49 enthalpic interaction coefficients of 6 different alkanes dissolved in 10 different alkan-1-ols with only one adjustable parameter.

Excess enthalpies of binary mixtures of n-octane with each of the hexane isomers at 298.15 K

Excess molar enthalpies, measured at 298.15 K in a flow microcalorimeter, are reported for the five binary systems formed by mixing n-octane with n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane and 2,3-dimethylbutane. The results for equimolar mixtures, together with similar data for other n-alkane + hexane isomer mixtures, are correlated in terms of the acentric factors of the n-alkanes.

Excess enthalpies of binary mixtures containing unsaturated hydrocarbons

The excess molar enthalpies H m E over the whole composition range of 1- n-hexene + trans-2-hexene, + trans-3-hexene, + 1,5-hexadiene, + trans-1,3-hexadiene, + trans-2,4-hexadiene, and + cis,trans-1,3,5-hexatriene, of trans-2-hexene + trans-3-hexene, + 1,5-hexadiene, and + trans-1,3-hexadiene, of trans-3-hexene + 1,5-hexadiene and + trans-1,3-hexadiene, and of 1,5-hexadiene + trans-1,3-hexadiene and + cis,trans-1,3,5-hexatriene were measured in a McGlashan-type calorimeter at 298.15 K. The influence of the unsaturated-bond position in the alkenes and dienes examined on the apparent magnitude of π-π interactions is discussed.

Excess enthalpies of binary mixtures of n-heptane with hexane isomers

Molar excess enthalpies, measured in a flow microcalorimeter, are reported for binary mixtures of n-heptane with the five isomeric hexanes. For equimolar mixtures at 298.15 K, deviations from ideality range from 0.46 J·mol−1 for n-hexane to 23.16 J·mol−1 for 2,2-dimethylbutane.

Excess enthalpies of binary mixtures of 2-ethyl-1-butanol with hexane isomers

Molar excess enthalpies, measured at 298.15 K in a flow microcalorimeter, are reported for binary mixtures of 2-ethyl-1-butanol with the five isomeric hexanes. The results are compared with previously published excess enthalpies for mixtures of 1-hexanol and 2-methyl-1-pentanol with the same hexane isomers.

Thermodynamic properties of binary mixtures of 2,4-lutidine and iso-aliphatic alcohols

The molar excess enthalpies of binary mixtures of 2,4-lutidine with isopropanol, isobutanol and 2-butanol at 293.15 and 303.15 K, and withtert-butanol at 303.15 K, were measured over the whole composition range.

Excess enthalpies of binary mixtures of 2-methyl-1-pentanol with hexane isomers

Kimura, F. and Benson, G.C., 1982. Excess enthalpies of binary mixtures of 2-methyl-1-pentanol with hexane isomers. Fluid Phase Equilibria, 8:107-112. Molar excess enthalpies, measured in a flow microcalorimeter, are reported for binary mixtures of 2-methyl-1-pentanol with n-hexane and its four isomers. There is a roughly linear correlation between the results for equimolar mixtures and the mean number of gauche conformations of the isomer.

Topological aspect of the excess enthalpies of binary mixtures of non-electrolytes

An approach based on the graph theory has been evolved to predict molar excess enthalpies. H E of binary mixtures of non-electrolytes. The calculated H E values compare reasonably well with the corresponding experimental values. The approach has also been successful in predicting H E data for binary mixtures at other temperatures from H E data at two mole fractions at one temperature only.

Excess enthalpies of binary mixtures of 1-hexanol with hexane isomers at 298.15 K

Excess enthalpies of binary mixtures of 1-hexanol with hexane isomers at 298.15 K

Thermodynamic properties of binary and ternary mixtures containing sulfolane V. Excess enthalpies of cyclohexane + benzene, cyclohexane + toluene, benzene + sulfolane, and toluene + sulfolane

Molar excess enthalpies for binary mixtures of benzene and toluene with cyclohexane and with sulfolane were measured with a commercial LKB flow microcalorimeter at 303.15 K. A double maximum in the composition-dependence curve of H E was observed for benzene + sulfolane. The results for sulfolane systems are compared with those of the corresponding dimethyl sulfoxide mixtures.

Thermodynamic properties of binary liquid mixtures involving weak specific interactions part III. Excess enthalpies of binary mixtures of tetrachloromethane and of tetrachloroethene with some alicyclic, pseudoaromatic, and aromatic hydrocarbons at 298.15 K

Handa, Y.P. and Benson, G.C., 1980. Thermodynamic properties of binary liquid mixtures involving weak specific interactions. Part III. Excess enthalpies of binary mixtures of tetrachloromethane and of tetrachloroethene with some alicyclic, pseudo-aromatic, and aromatic hydrocarbons at 298.15 K. Fluid Phase Equilibria, 4: 277–285. An LKB flow microcalorimeter has been used to measure excess enthalpies at 298.15 K for mixtures of tetrachloromethane and of tetrachloroethene with cyclo-hexene, 1,4-cyclohexadiene, cycloheptane, and cycloheptene. The mixtures tetrachloroethene + cyclohexane, and + benzene have also been studied. The results are discussed in terms of the electron accepting properties of tetrachloromethane and tetrachloroethene.

Thermodynamic properties of binary liquid mixtures involving weak specific interactions: Part II. Excess enthalpies of binary mixtures of tetrachloroethene with some aromatic hydrocarbons at 298.15 K

An LKB flow microcalorimeter has been used to measure excess enthalpies at 298.15 K for mixtures of tetrachloroethene with methylbenzene, isomeric dimethylbenzenes, 1,3,5-trimethylbenzene, ethylbenzene, isopropylbenzene, tert.-butylbenzene, and hexylbenzene. The results are compared with the excess enthalpies (Part I) at 298.15 K for mixtures of tetrachloromethane with the same set of second components. It is suggested that tetrachloroethene, like tetrachloromethane, acts as an electron acceptor towards aromatic hydrocarbons.

Thermodynamic properties of binary liquid mixtures involving weak specific interactions: Part I. Excess enthalpies of binary mixtures of tetrachloromethane with some aromatic hydrocarbons at 298.15 K

An LKB flow microcalorimeter has been used to measure excess enthalpies at 298.15 K for tetrachloromethane + methylbenzene, + isomeric dimethylbenzenes, + 1,3,5-trimethylbenzene, + ethylbenzene, + isopropylbenzene, + tert.-butylbenzene, and + hexylbenzene. The results are compared with previous literature values.

Excess enthalpies of binary mixtures of a cyclic acetal + a solvent at 298.15 K

The excess enthalpies of 1,3-dioxolane + n-heptane, + benzene, and + tetrachloromethane, 2-methyl-1,3-dioxolane + n-heptane, + benzene, and + tetrachloromethane, 2,2-dimethyl-1,3-dioxolane + n-heptane, and 2,2-diethyl-1,3-dioxolane + n-hexane, + n-heptane, + n-octane, + n-nonane, + n-decane, + benzene, and + tetrachloromethane have been measured at 298.15 K as a function of composition.

Excess enthalpies of binary mixtures containing unsaturated hydrocarbons 3. n-Alkane + n-alkyne and tetrachloromethane + n-alkyne

Molar excess enthalpies were measured in a continuous titration calorimeter of the Becker-Kiefer type over the whole composition range for n-hexane or tetrachloromethane + 1- n-hexyne, + 3- n-hexyne and for n-heptane or tetrachloromethane + 1- n-heptyne at 298.15 K. The influence of the position of the unsaturated bond on the π-π and π-n interactions is discussed in terms of the results described previously.

Excess enthalpies at 298.15 K of binary mixtures of cyclohexane with n-alkanes

Molar excess enthalpies for binary mixtures of cyclohexane + n-hexane, + n-octane, + n-decane, + n-undecane, + n-hexadecane, and n-heptadecane, were measured at 298.15 K. All these mixings were endothermic. The Redlich-Kister equation was used to correlate these mixtures H E with composition.

Calculation of excess enthalpies for binary mixtures of liquid metal halides

A semi-empirical equation, based on simple regular solution theory and involving only dispersion and charge–dipole interactions, is deduced for the excess enthalpy, HE, of a family of molten salt mixtures. The hard-core separation, λ, calculated from scaled particle theory, is adopted for the anion-cation separation in the melt. When the excess enthalpies at the equimolar composition, calculated from the derived equation, are compared with the experimental HE values available for 37 of the possible 40 binary alkali halide mixtures with a common anion, almost perfect agreement is obtained.

Evaluation of excess enthalpies from flow-calorimetric measurements of enthalpies of dilution using local approximation by polynomials

A method is described for the evaluation of excess enthalpies of binary mixtures from results of flow-calorimetric measurements of enthalpies of dilution and mixing of mixtures of the components. The power Q ̇ generated when two mixtures of mole fractions x A and and x B are mixed can be expressed as: Q ̇ = ( n ̇ A + n ̇ B )H E (x C ) − n ̇ A H E (x A ) − n ̇ B H E (x B ) where n ̇ denotes molar flow rate of the respective solution and H E the molar excess enthalpy at the indicated mole fraction. From a series of measurements covering the whole composition range, sets of equations containing H E( x) as unknowns are obtained. One assumes that values of H E( x) can be interpolated from values of H E( z) at a fixed set of mole fractions “z’ using a linear interpolation formula H E( x) = Σc 1 H E( z 1). In each interpolation a fixed number of z-nodes closest to x are used. The coefficients c 1 are calculated as the coefficients in the Lagrangian interpolation formula and depend only on x and z 1. The resulting overdetermined linear equation system which contains the values of H E( z) as unknowns is solved by a standard least-squares procedure. Intermediate values of H E are interpolated from the calculated set. The advantage of the method is that no analytical expression for H E as a function of composition is needed. The method has been tested on water + ethanol at 298.15 K. Values of H E derived in the present study agree well with directly determined values of H E reported in the literature. The approximation method presented is considered applicable generally for the evaluation of integral quantities from results of measurements of differential quantities.