Application of the Prigogine-Flory-Patterson theory part II. Mixtures of a bicyclic compound,benzene, cyclohexane,n-hexane with a 1-alkene and a 1-alkyne

The Prigogine-Flory-Patterson theory of liquid mixtures has been applied to the H _m ^E and V _m ^E for binary mixtures of an n-alkane with decalin, bicyclohexyl, tetralin, cyclohexylbenzene, benzene, cyclohexane and n-hexane with 1-hexene, 1-hexyne, 1-heptene and 1-heptyne. Furthermore the Prigogine-Flory theory has been used to predict activity coefficients at infinite dilution from the experimentally determined H _m ^E at 25°C for the mixtures 1-hexene, 1-hexyne, 1-heptene, 1-heptyne with decalin, bicyclohexyl, tetralin and cyclohexylbenzene. The predictions are compared to experimental results.     

Application of the Prigogine-Flory-Patterson theory part III. Mixtures of a bicyclic compound,benzene, cyclohexane,n-hexane with a cycloalkane,cyclohexene, a cycloalkadiene and benzene

The Prigogine-Flory-Patterson theory of liquid mixtures has been qpplied to the H _m ^E and V _m ^E for binary mixtures of a bicyclic compound, benzene, cyclohexane and n-hexane with a cycloalkane, cyclohexene, a cycloalkadiene and benzene. Furthermore the Prigogine-Flory theory has been used to predict activity coefficients at infinite dilution from the experimentally determined H _m ^E at 25°C for the mixtures cyclohexane, cyclohexene, 1,3-cyclohexadiene, 1,4-cyclohexadiene and benzene with a bicyclic compound. The predictions are compared to experimental results.     

The thermodynamics of mixing C6 and C7 compounds with a bicyclic compound at infinite dilution

The activity coefficients at infinite dilution have been measured at 25°C for cyclohexane, cyclohexene, 1,3-cyclohexadiene, 1,4-cyclohexadiene, benzene, n-hexane, 1-hexene, 1-hexyne, n-heptane, 1-heptene and 1-heptyne in decahydronaphthalene, bicyclohexyl, 1,2,3,4-tetrahydronaphthalene and cyclohexylbenzene. These results, together with previously determined H _m ^E and V _m ^E have been used to calculate the partial molar excess thermodynamic properties of mixing at infinite dilution.     

Excess volumes and enthalpies of mixing benzene with various bicyclic compounds

The V _m ^E and H _m ^E for solutions of benzene in decahydronaphthalene, in bicyclohexyl, in cyclohexylbezene and in 1,2,3,4-tetrahydronaphthalene have been measured over the complete composition range at 25°C. The results have been fitted to the Flory theory of liquid mixtures.     

Excess volumes of decahydronaphthalene inn-alkanes at 10 and 25°C

The molar excess volumes of mixing decahydronaphthalene (decalin) with n-pentane, n-hexane, n-heptane, n-octane, n-dodecane and n-hexadecane have been measured over the whole composition range at two temperatures. These results together with the calculated molar excess volume temperature coefficients at equimolar composition have been compared with the results of other two-ring compounds (bicyclohexyl and tetralin) in the same n-alkanes.     

Excess enthalpies of decahydronaphthalene in cycloalkanes and inn-Alkanes at two temperatures

The H _m ^E of decahydronaphthalene in cyclopentane, cyclohexane, cycloheptane, cyclooctane, n-hexane, n-heptane, n-octane, n-dodecane and in n-hexadecane have been measured over the whole composition range at two temperatures. These results together with previously reported V _m ^E results for the same systems have been fitted to the Flory theory of liquid mixtures.     

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 molar volumes of diethyl carbonate with hydrocarbons or tetrachloromethane at 25°C

The excess molar volumes V _m ^E at atmospheric pressure and at 25°C for binary mixtures of diethyl carbonate with n-heptane, n-decane, n-tetradecane, 2,2,4-trimethylpentane, cyclohexane, benzene, toluene, or tetrachloromethane have been obtained over the whole mole-fraction range from densities measured with a vibrating-tube densimeter. The V _m ^E are positive for all the systems investigated, except for the mixture with toluene which is negative. The results for V _m ^E together with data previously published on excess molar enthalpies H _m ^E and excess molar Gibbs energies G _m ^E , suggest interactions between carbonate and hydrocarbons which are stronger with aromatic than with aliphatic hydrocarbons.Thermodynamics of binary mixtures containing organic carbonates, Part 10.     

Salt Effects on Volumetric Properties of Some n-Alkoxyethanols (C1Em, m = 1, 2, and 3) in Aqueous Solutions at 298.15 K

Accurate density measurements over the whole composition range were made at a temperature of 298.15 K under ambient pressure for the mixtures of ethylene glycol monomethyl ether (2-methoxyethanol, C₃H₇O₂; C₁E₁), or diethylene glycol monomethyl ether (2-(2-methoxyethoxy)ethanol, C₅H₁₂O₃; C₁E₂), or triethylene glycol monomethyl ether [2-{2-(2-methoxyethoxy)ethoxy}ethanol, C₇H₁₆O₄; C₁E₃) in aqueous salt solutions having a common anion with a view to examining the cationic effect on the volumetric properties. To gain insight into the mixing behavior, results of the density measurements were used to estimate excess molar volumes, V_m^E, apparent molar volumes, V_{, i}, partial molar volumes, , excess partial molar volumes, V_m,i^E, and their limiting values at infinite dilution, V_{, i}, V_m,i, and V_m,i^E,, respectively. Aqueous solutions of the chlorides of lithium, sodium, potassium, and calcium in a concentration range to ca. 1 mol-kg^–1 were chosen for investigation as this concentration is used most frequently in applied chemistry. All mixtures except that containing lithium chloride show a decrease in the magnitude of V_m^E with the addition of a salt when compared to salt-free mixtures. Comparison of the derived volumes at infinite dilution suggested modification of the water structure as well as an electrostatic interaction between the ionic species and an alkoxyethanol molecule.     

Liquid Solution Densities of Ternary-Pseudobinary Mixtures of (Benzene + Cyclohexane) in the Presence of Tetrachloromethane or <Emphasis Type="Italic">n</Emphasis>-Hexane

Densities have been obtained as a function of composition for ternary-pseudobinary mixtures of [(benzene + tetrachloromethane or n-hexane) + (cyclohexane + tetrachloromethane or n-hexane)] at atmospheric pressure and the temperature 298.15 K, by means of a vibrating-tube densimeter. Excess molar volumes, V_m^E, partial molar volumes and excess partial molar volumes were calculated from the density data. The values of V_m^E have been correlated using the Redlich–Kister equation and the coefficients and standard errors were estimated. The experimental and calculated quantities are used to discuss the mixing behavior of the components. The results show that the third component, CCl₄ or n-C₆H₁₄, have quite different influences on the volumetric properties of binary liquid mixtures of benzene with cyclohexane.     

Excess Molar Volumes and Excess Partial Molar Volumes of Triethylene Glycol Monoethyl Ether–n-Alcohol Mixtures at 25°C

We have measured excess molar volumes V^E _m of binary mixtures of triethylene glycol monoethyl ether with methanol, ethanol, 1-propanol, 1-pentanol, and 1-hexanol over the full range of compositions at 25°C. The measurements were carried out with a continuous-dilution dilatometer. The excess molar volumes V^E _m are negative over the entire range of composition for the systems triethylene glycol monoethyl ether + methanol, + ethanol, and + 1-propanol and positive for the remaining systems, triethylene glycol monoethyl ether + 1-pentanol, and + 1-hexanol. The excess V^E _m increases in the positive direction with increasing chain length of the n-alcohol. The measured excess volumes have been compared to our previous published data with an effort to assess the effects of replacing methyl by ethyl groups and of inserting oxyethylene groups. The results have been used to estimate the excess partial molar volumes V^E _m,i of the components. The behavior of V^E _m and V^E _m,i with composition and the number of carbon atoms in the alcohol molecule is discussed.     

Thermodynamic Properties of Binary Mixtures of Cyclohexanone with n-Alkanols (C1–C5) at 293.15 K

The excess molar volumes (V^E), excess surface tensions (σ^E), and deviations in molar refraction (R^E) and isentropic compressibility (k_s^E) of binary mixtures of cyclohexanone with methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol have been determined over the entire composition range at 293.15 K. The results were fitted by the Redlich–Kister polynomial equation and the corresponding binary coefficients A_k have been derived. The standard deviations between the calculated and the experimental excess properties have been determined. The results provide information on the interactions of the molecules in the pure liquids as well as in the binary mixtures.     

A Study of Excess Molar Enthalpies and Excess Molar Volumes of Binary Mixtures of 1-Chloropentane + 1-Alkanol (from 1-Butanol to 1-Octanol) at 25°C.

Excess molar enthalpies H ^E _mand excess molar volumes V ^E _m at 25°Cand normal atmospheric pressure for the binary mixtures 1-chloropentane + 1-alkanol(from 1-butanol to 1-octanol) have been determined using a Calvet microcalorimeterand from density measurements using a vibrating tube densimeter. The H ^E _m valuesfor all the mixtures are positive and V ^E _m values are positive or negative dependingon the mole fraction of the chloroalkane. Experimental H ^E _m results are comparedwith the predictions of UNIFAC group-contribution models proposed by Dang andTassios and by Larsen et al., and are discussed in terms of molecular interactions.     

The excess volumes of tetrahydronaphthalene inn-alkanes at 10 and 25°C

The excess volume of mixing tetrahydronaphthalene with n-pentane, n-hexane, n-heptane, n-octane, n-dodecane and n-hexadecane have been measured over the whole composition range at two temperatures. The results are compared to the excess volume of mixing bicyclohexyl with the same solvents.     

Excess Molar Enthalpies and Excess Molar Volumes of Binary Mixtures of Benzene and Alkanols with Quinoline

Molar excess enthalpies H _m ^E have been determined over the whole composition range for mixtures of benzene, methanol, ethanol, 1-propanol, 2-propanol and 1-butanol with quinoline at 298.15 K using a Thermometric flow calorimeter. The results reflect a strong H-bond association between an alkanol and quinoline which decreases with increasing length of the alkanol chain. The small H _m ^E for (benzene+quinoline) reflects the similarity of the two molecules. This revised version was published online in August 2006 with corrections to the Cover Date.     

Excess Molar Volumes and Excess Partial Molar Volumes of Triethylene Glycol Monomethyl Ether–n-Alcohol Mixtures at 25°C

The excess molar volumes V ^E have been measured for binary mixtures of triethylene glycol monomethyl ether with methanol, ethanol, 1-propanol, 1-pentanol, and 1-hexanol as a function of composition using a continuous–dilution dilatometer at 25°C at atmosphere pressure. V ^E are negative over the entire range of composition for the systems triethylene glycol monomethyl ether + methanol, + ethanol, and + 1-propanol, and positive for the remaining systems, containing 1-pentanol and + 1-hexanol. V ^E increases in a positive direction with increasing carbon chain length of the n-alcohol. The excess partial molar volumes V _i ^E of the components were evaluated from the V ^E results. The behavior of V ^E and V _i ^E with composition and the number of carbon atoms in the alcohol molecule is discussed.     

Volumetric and optical study of molecular association in binary mixtures of dimethyl sulphoxide with carboxylic acid

Density and refractive index have been measured for the binary mixture of dimethyl sulphoxide (DMSO) with propanoic acid and n-butyric acid at three temperatures, 293, 303 and 313 K, over the entire composition range. Excess parameters such as excess molar volume (V ^E) and molar refraction deviation (ΔR _m) have been calculated from the measured density and refractive index to study the molecular association between the component molecules. The V ^E and ΔR _m values of these mixtures were fitted to the Redlich–Kister polynomial equation. Both excess parameters were plotted against the mole fraction of DMSO over the whole composition range. The values of V ^E and ΔR _m have been found to be negative for both mixtures over the entire composition range, which suggests the presence of strong intermolecular interaction. The experimental refractive data of these mixtures were also used to test the validity of the empirical relations for the refractive index.     

Excess thermodynamic properties of binary liquid mixtures containing cyclohexylamine at 30°C

The excess volumes of mixing of cyclohexylamine with n-hexane, n-heptene, n-octane, n-nonane, benzene, toluene, nitrobenzene, chlorobenzene and bromobenzene have been measured at 30°C. For all systems except for n-hexane, V ^E is positive over the entire mole fraction range. For the n-hexane mixtures, a sigmoid curve is obtained with negative V ^E at high mole fraction of amine.     

Thermodynamic properties of binary mixtures of 2-hexanone withn-alkanes at 35°C

Excess molar enthalpies h ^E and excess molar volumes v ^E of the binary liquid mixtures 2-hexanone+n-alkane (from n-heptane to n-decane) have been determined for various values of the mole fraction of hexanone at 35°C and atmospheric pressure. Excess molar enthalpies were determined by Calvet microcalorimetry and v ^E from densities measured by vibratingtube densimetry. The results are compared with the predictions of several group contribution models.     

The effect of pressure on order destruction and order creation in linear or branched alkane mixtures

The pressure dependence of the excess enthalpy H ^E , dH ^E /dP, has been calculated from experimental excess volumes V ^E and dV ^E /dT using dH ^E /dP=V ^E –TdV ^E /dT. dH ^E /dP at zero pressure are reported at 25°C and equimolar concentration for the mixtures: cyclohexane with the series of normal alkanes (n-C _n , where n=6,8,10,12,14 and 16) and with the series of highly branched alkanes (br-C _n , where n=6,8,12 and 16), benzene, toluene and p-xylene +n-C _n and 1-chloronaphthalene +n-C _n and br-C _n . Experimental and Flory theory dH ^E /dP values are in good agreement for the whole cyclohexane +br-C _n series. For the n-C _n series, dH ^E /dP becomes increasingly positive deviating from the Flory predictions. This discrepancy is due to the presence of short-range orientational order in the higher n-C _n pure liquids which makes dH/dP more negative and which, upon mixing, is destroyed producing a positive contribution to dH ^E /dP not accounted for by the theory. The discrepancy between theoretical and experimental dH ^E /dP is large for benzene, but progressively smaller for toluene, p-xylene and 1-chloronaphthalene. These results are consistent with creation of order between the aromatic plate-like molecule and the long n-C _n in solution. For 1-chloronaphthalene +n-C _n , this order creation process produces a negative contribution to dH ^E /dP which balances the positive order-destruction contribution originated by the rupture, upon mixing, of short-range orientational order in pure n-C _n .