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1.
Abstract

Excess molar volumes VE of binary mixtures of benzene + 1-propanol, + 1-butanol, + 1-pentanol, + 1-hexanol, + 1-heptanol, + 1-octanol, + 1-nonanol and 1-decanol were measured at 303.15 K. The VE values are positive over the entire range of composition for these mixtures. The results are discussed in terms of intermolecular interactions.  相似文献   

2.
Abstract

Molar excess volumes (VE ) and partial molar excess volumes ( VE ) are reported for non-electrolyte binary mixtures of n-pentanol + cumene, n-pentanol + 1,4-dioxane and cumene + 1,4-dioxane at four temperatures and over the whole concentration range. In these systems, the n-pentanol is a highly polar molecule with association in its pure state, while the others two show little polarity without association in their pure states. The results of VE are discussed in terms of the interactions between components. The Prigogine–Flory–Patterson model of solution thermodynamics has been used to predict VE . This work shows the importance of the three contributions δV int, δV p? and δVF to VE .  相似文献   

3.
The excess molar volumes VE for binary liquid mixtures containing dipropylene glycol monomethyl ether and methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, and 1-heptanol have been measured using a continuous dilution dilatometer over the whole mole fraction range at 25°C at atmospheric pressure. VE are negative over the whole composition range except for the systems containing 1-pentanol, 1-hexanol, or 1-heptanol which are positve at every composition. VE increases in a positive direction with increase in chain length of the n-alcohol. The results have been used to estimate the excess partial molar volumes ViE of the components. The change of VE and ViE with composition and the number of carbon atoms in the alcohol molecule are discussed as a basis to understand some of the molecular interactions present in the mixtures:  相似文献   

4.
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.  相似文献   

5.
Densities, ρ and excess molar volumes, V?E of the binary mixtures of sulfolane, +methanol, +n-propanol,?+n-butanol, and +n-pentanol were measured at temperatures 298.15, 303.15, 308.15, 313.15, and 318.15?K, respectively, covering the whole composition range except methanol at 303.15–323.15?K. The V E for the systems were found to be negative and large in magnitude. The values of V E of the sulfolane, +n-butanol and sulfolane, +n-pentanol mixtures are being positive at lower and higher mole fractions of the alkanols (x 2). The magnitudes of the V E values of the mixtures are in the order sulfolane?+?methanol?>?sulfolane?+?n-propanol?>?sulfolane?+?n-butanol?>?sulfolane?+?n-pentanol. The observed values of V E for the mixtures have been explained in terms of (i) effects due to the differences in chain length of the alcohols, (ii) dipole–dipole interactions between the polar molecules, and (iii) geometric effect due to the differences in molar volume of the component molecules. These are more noticeable in the case of lower alcohols. All these properties have been expressed satisfactorily by appropriate polynomials.  相似文献   

6.
We have measured excess molar volumes VE 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 VE 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 VE 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 VE m,i of the components. The behavior of VE m and VE m,i with composition and the number of carbon atoms in the alcohol molecule is discussed.  相似文献   

7.
Excess molar volumes, V E m, at 25°C and atmospheric pressure, over the entire composition range for binary mixtures of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol with-methylbutylamine are reported. They are calculated from densities measured with a vibrating-tube densimeter. All the excess volumes are large and negative over the entire composition range. This indicates strong interactions between unlike molecules, which are greatest for the system involving methanol, characterized by the most negative V E m. For the other solutions, V E m at equimolar composition, is approximately the same. The V E m curves vs. mole fraction are nearly symmetrical. The ERAS model is applied to 1-alkanol + N-methylbutylamine, and 1-alkanol + diethylamine systems. The ERAS parameters confirm that the strongest interactions between unlike molecules are encountered in solutions with methanol. The model consistently describes V E m and excess molar enthalpies H E m of the mixtures studied.  相似文献   

8.
Values for excess functions (HE,VE,GE, TSE) are reported for 3-pentanol+ diethylamine mixtures at 298.15 K. The results indicate formation of three hydrogen bonds per molecule 3-pentanol in excess diethylamine, and of two hydrogen bonds per molecule diethylamine in excess 3-pentanol.  相似文献   

9.
The excess molar volumes, V mE, viscosity deviations, Δη, and excess Gibbs energies of activation, ΔG *E, of viscous flow have been investigated from density and viscosity measurements for two ternary mixtures, 1-butanol + triethylamine + cyclohexane and 1-pentanol + triethylamine + cyclohexane, and corresponding binaries at 303.15 K and atmospheric pressure over the entire range of composition. The empirical equations due to Redlich-Kister, Kohler, Rastogi et al., Jacob-Fitzner, Tsao-Smith, Lark et al., Heric-Brewer, and Singh et al. have been employed to correlate V mE, Δη and ΔG *E of the ternary mixtures with their corresponding binary parameters. The results are discussed in terms of the molecular interactions between the components of the mixture. Further, the Extended Real Associated Solution, ERAS, model has been applied to V mE for the present binary and ternary mixtures, and the results are compared with experimental data.  相似文献   

10.
The excess molar volumes (VE), excess surface tensions (σE), and deviations in molar refraction (RE) and isentropic compressibility (ksE) 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 Ak 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.  相似文献   

11.
Volume changes on mixing of binary systems formed by 1,2-dichloroethane andn-alcohols, namely, ethanol,n-propanol,n-butanol,n-pentanol andn-hexanol were measured as a function of composition at 30, 35, 40 and 45 °C. At all compositions theV E values are all positive for all systems. The molar excess volumes of mixing for equimolar mixtures increase as the length of carbon chain increases.V E becomes more positive on increasing temperature. The positive value of the excess volume has been attributed to breaking of hydrogen bonds of associated species of alcohol by dilution with 1,2-dichloroethane.  相似文献   

12.
Abstract

Excess volumes (VE ) and deviations in isentropic compressibilities (Ks ) were reported over the entire mole fraction range for mixtures of 1-heptanol with 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trichloroethene and tetrachloroethene, at 303.15 K. The values of VE and Ks are positive for the systems, 1-heptanol + 1,2-dichloroethane, +1,1,1-trichloroethane, + trichloroethene and + tetrachloroethene. Inversion in sign of VE and Ks from positive to negative is observed in mixtures of 1-heptanol with 1,1,2,2-tetrachloroethane. The experimental data were used to explain the effect of successive chlorination and unsaturation of ethane molecule on VE and Ks .  相似文献   

13.
《Fluid Phase Equilibria》2002,198(2):313-329
Excess molar volumes, VmE, at 298.15 K and atmospheric pressure over the entire composition range for binary mixtures of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol with dibutylamine are reported. They are calculated from densities measured with a vibrating-tube densimeter. All the excess volumes are large and negative over the whole mole fraction range, indicating strong interactions between unlike molecules, which are more important for the systems involving methanol or ethanol, characterized by the most negative VmE. For the other mixtures, VmE at equimolar composition, is approximately constant. The VmE curves are nearly symmetrical. The VmE and excess molar enthalpies (HmE) of the mixtures studied are consistently described by the ERAS model. The ERAS parameters confirm that the strongest interactions between unlike molecules are encountered in the methanol+dibutylamine system.  相似文献   

14.
ABSTRACT

The densities and relative permittivities of binary mixtures of N,N-dimethylacetamide with 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol and 2-butoxyethanol have been measured as a function of composition, at T = 298.15 K. From the experimental data the excess molar volume (VE) from a mole fraction and the excess relative permittivity (εE) from a volume fraction average have been calculated. The results are discussed in terms of intermolecular interactions and structure of studied binary mixtures.  相似文献   

15.
Molar excess volumes, VE, molar excess enthalpies, HE, and speeds of sound data, u, of pyrrolidin-2-one (i) + ethanol or propan-1-ol or propan-2-ol or butan-1-ol (j) binary mixtures have been determined over entire composition range at 308.15 K. The observed speeds of sound data have been utilized to predict excess isentropic compressibilities, of the investigated binary mixtures. The observed excess thermodynamic properties VE, HE and have been analyzed in terms of Graph theory. The analysis of VE data by the Graph theory suggests that pyrrolidin-2-one exists mainly as a mixture of cyclic and open dimer; ethanol as a mixture of dimer and trimer; butan-1-ol and propan-2-ol as mixture of monomer and dimer and propan-1-ol as a dimer in the pure state, and their mixtures contain 1:1 molecular complex. The IR studies lend additional credence to the nature and extent of interactions for the proposed molecular entities in the mixtures. Also, it has been observed that VE, HE and values predicted by the Graph theory compare well to with their corresponding experimental values.  相似文献   

16.
Chandramouli, J., Choudary, N.V., Krishnaiah, A. and Naidu, P.R., 1982. Thermodynamic properties of binary liquid mixtures involving weak interactions. Part 1. Excess volumes of binary mixtures of 1-chlorobutane with normal alkanols at 303.15 K. Fluid Phase Equilibria, 8: 87–92Excess volumes for binary mixtures of 1-chlorobutane with 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol have been determined at 303.15 K. VE is positive over the whole range of composition for the mixtures of 1-chlorobutane with 1-propanol and 1-butanol. An inversion in the sign of VE is observed over certain ranges of concentration of the halogenated alkane in the remaining four mixtures. The results are explained in terms of depolymerisation of hydrogen-bonded alcohol aggregates, decrease in dipolar association, and weak hydrogen-bonding interaction of the type Cl- - - HO between unlike molecules.  相似文献   

17.
Abstract

This paper reports excess volumes, VE , and viscosity deviations, Δ\eta, for binary mixtures of 2-methyl-1-chloropropane with an isomer of butanol at the temperatures 298.15 K and 313.15 K. These properties were obtained from density and viscosity measurements. The results are correlated by means of a Redlich-Kister type equation, and interpreted in terms of molecular interactions. The systems show positive values of VE except in a short range of compositions for mixtures containing primary butanols (1-butanol at both temperatures and 2-methyl-1-propanol at 298.15 K), whereas Δ\eta presents negative values at both temperatures over the whole composition range.  相似文献   

18.
Summary. Density (ρ) and viscosity (η) values of the binary mixtures of DMP + 1-pentanol, 1-butanol, and 1-propanol over the entire range of mole fraction at 298.15 and 303.15 K were measured in atmospheric pressure. The excess molar volume (V E), viscosity deviations (Δη), and excess Gibbs energy of activation for viscous flow (G*E) were calculated from the experimental measurements. These results were fitted to Redlich–Kister polynomial equation to estimate the binary interaction parameters. The viscosity data were correlated with equations of McAllister. The calculated functions have been used to explain the intermolecular interaction between the mixing components.  相似文献   

19.
Abstract

Densities and viscosities of the ternary mixture (benzene + 1-propanol + ethyl acetate) and the corresponding binary mixtures (benzene + 1-propanol, benzene + ethyl acetate and 1-propanol + ethyl acetate) have been measured at the temperature 298.15 K. From these measurements excess volumes, VE , excess viscosities, ηE, and excess Gibbs energies of activation for viscous flow, G*E , have been determined. The equation of Redlich-Kister has been used for fitting the excess properties of binary mixtures. The excess properties of the ternary system were fitted to Cibulka's equation.  相似文献   

20.
Excess molar volumes, V E, are reported for binary mixtures of 1-hexanol with the homologous C6, C7, C8, and C10 1-alkenes at 25°C. In this series of mixtures, the V E values vary as a function of mole fraction from positive–negative sigmoid shaped curves exhibiting a very small positive lobe in the dilute alkanol region for the shortest chain 1-alkene to positive values over the whole concentration range for the longer chain 1-alkene. The partial molar excess volumes, V i E, were calculated for the components over the whole concentration range. The partial molar volume of 1-hexanol in the 1-hexene system shows a large and sharp minimum and in the 1-decene system is positive over the whole concentration range. The modified model [Treszczanowicz et al., J. Solution Chem. 31, 455 (2002) originally proposed by Treszczanowicz and Benson Fluid Phase Equilibr. 23, 117 (1985)] was used for the interpretation and prediction of the reported data. The model describes qualitatively the variation of V E with the length of the molecule and concentration as a result of superposition of the contributions of association, free volume, and nonspecific interactions.  相似文献   

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