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1.
Excess molar volumes (V m E ) and viscosities (η) of the binary mixtures of 1,2-diethoxyethane with di-, tri- and tetrachloromethane have been measured at 298-15 K and atmospheric pressure over the entire mole fraction range. The deviations in viscosities (δlnη) and excess energies of activation (δG*E) for viscous flow have been calculated from the experimental data. The Prigogine-Flory-Patterson (PFP) model has been used to calculateV m E , and the results have been compared with experimental data. The Bloomfield and Dewan model has been used to calculate viscosity coefficients and these have also been compared with experimental data for the three mixtures. The results have been discussed in terms of dipole-dipole interactions between 1,2-diethoxyethane and chloroalkanes and their magnitudes decreasing with the dipole character of the molecules. A short comparative study with results for mixtures with polyethers and chloroalkanes is also described.  相似文献   

2.
Capillary viscometry was used to determine the kinematic viscosity of the binary systems composed of N-methylpyrrolidone + monoethanolamine and N-methylpyrrolidone + diethanolamine throughout the concentration range, at eight different temperatures in the range 303.15–373.15 K. Pure component values of viscosity were also determined in the temperature range 303.15–423.15 K. Using a rolling ball viscometer the absolute viscosity was obtained for the binary systems composed of tetramethylene sulfone (sulfolane) + monoethanolamine and tetramethylene sulfone + diethanolamine, throughout the concentration range, at three different temperatures in the range 303.15–373.15 K. Density results were obtained using a vibrating-tube densimeter for the four pure components and the four binary systems studied, in the same temperature range and the whole concentration range for the binary systems as the viscosity measurements.

The experimental viscosity results for the four pure solvents cover a broader temperature range than previously reported by other workers. The experimental results of viscosity for both pure and binary systems show a decrease with increasing temperature as expected. In the case of the binary systems the change of viscosity with concentration for the two sets of mixtures with N-methylpyrrolidone is very large in the range of 303.15–353.15 K, whereas it is small in the range 363.15–373.15 K. The observed behaviour of the change of viscosity with concentration for sulfolane with monoethanolamine is different from that shown by sulfolane with diethanolamine, at 303.15 and 323.15 K; the first system shows a minimum viscosity point in the sulfolane-rich region whereas at 373.15 K it shows values of viscosity greater than that of the pure components in the whole range of concentration; and the second system shows large variations of viscosity at low sulfolane concentration, at 303.15 and 323.15 K; whereas at 373.15 K the viscosity values change smoothly between those for the two pure components.

From the density results, molar excess volumes were derived, which were correlated using the Redlich–Kister equation; the final expression includes the functionality with both concentration and temperature.  相似文献   


3.
Abstract

From dilatometric method at 293.15,303,15, and 313.15K for binary mixtures of water and 1,2-alkane diols, the excess molar volumes, VE and the partial molar volumes, V i of both components at 293.15 K have been obtained as a function of mixtures composition. Excess molar volumes were calculated and correlated by a Redlich-Kister type function in terms of mole fraction. The partial molar volumes have been extrapolated to zero concentration to obtain the limiting values at infinite dilution, V 0 i . All mixtures showed negative values and decreases with the chain length of diols. The values become less negative with increasing temperature. The results are explained in terms of dissociation of the self-associated diol molecules and the formation of aggregates between unlike molecules.  相似文献   

4.
The values of density (ρ), viscosity (η) and speed of sound (u) have been measured for binary liquid mixtures of γ-butyrolactone (GBL), δ-valerolactone (DVL), and ε-caprolactone (ECL) with N-methylacetamide (NMA) over the whole composition range at T = (303.15 to 318.15) K and atmospheric pressure. From these data, excess molar volume (VE), deviation in viscosity (Δη), and deviation in isentropic compressibility (Δκs), are calculated. The results are fitted to a Redlich–Kister type polynomial equation to derive binary coefficients and standard deviations.  相似文献   

5.
Excess volumes (VE) ultrasonic sound velocities (u), isentropic compressibilities (Ks) and viscosities (η) have been measured for the binary mixtures of dimethylsulphoxide (DMSO) with 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,2,4-trichlorobenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-nitrotoluene and m-nitrotoluene at T = 303.15 K. The measured VE values were positive over the entire composition range in all the binary mixtures. Isentropic compressibilities (Ks) have been computed for the same systems from precise sound velocity and density data. Further, deviation in isentropic compressibility (ΔKs) from ideal behaviour was also calculated. The viscosity data are analysed on the basis of corresponding states approach. Deviation in viscosities are positive over the entire composition range. The measured data is explained on the basis of intermolecular interactions between unlike molecules.  相似文献   

6.
The viscosity deviation (Δη), the excess molar volume (V E) and the ultrasonic speed (u) have been investigated from viscosity (η) and density (ρ ) measurements of binary liquid mixtures of 1,2-dimethyoxyethane with methanol, ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol or octan-1-ol over the entire range of composition at 298.15 K. The excess volumes are negative over the entire range of composition for all of the mixtures with the exception of hexan-1-ol and octan-1-ol. The excess isentropic compressibilities (K S E) and viscosity deviations are negative for all of the mixtures. The magnitudes of the negative values of V E decrease with the number of carbon atoms of the alkan-1-ol. The trend of increasing K S E values with the chain length of the alkanol is similar to that observed in the case of V E. Graphs of V E, Δ η, K S E, Δ u, L f E and Z E against composition are presented as a basis for a qualitative discussion of the results.  相似文献   

7.
《Fluid Phase Equilibria》1998,145(1):89-97
Relative permittivities, ϵr, and refractive indices, nD, have been measured for binary liquid mixtures of cyclohexanone (C6H10O) with dichloromethane (CH2Cl2), trichloromethane (CHCl3), 1,2-dichloroethane (CH2ClCH2Cl), trichloroethene (CHClCCl2), and cyclohexane (c-C6H12) at T=303.15 K. The values of the deviations of ϵr and nD from values arising from mole fraction average, which are represented respectively by Δϵr and ΔnD have been calculated. Values of ϵr and ΔnD have been fitted by the method of least squares to smoothing equations. Δϵr for the various mixtures has been discussed from the viewpoint of the existence of specific interactions between the components.  相似文献   

8.
D. Sen  M.G. Kim   《Thermochimica Acta》2008,471(1-2):20-25
The excess molar volumes and excess molar enthalpies over the whole range of composition have been measured for the binary mixtures formed by 1,2-dichloropropane (1,2-DCP) with three 2-alkoxyethanol acetates at 298.15 K and atmospheric pressure using a digital vibrating-tube densimeter and an isothermal calorimeter with flow-mixing cell, respectively. The 2-alkoxyethanol acetates are ethylene glycol monomethyl ether acetate (EGMEA), ethylene glycol monoethyl ether acetate (EGEEA), and ethylene glycol monobutyl ether acetate (EGBEA). The of the mixture has been shown positive for EGMEA, ‘S-shaped’ for EGEEA, being negative at low and positive at high mole fraction of 1,2-DCP, and negative for EGBEA. All the values for the above mixtures showed an exothermic effect (negative values) which increase with increase in carbon number of the 2-alkoxyethanol acetates, showing minimum values varying from −374 J mol−1 (EGMEA) to −428 J mol−1 (EGBEA) around 0.54–0.56 mol fraction of 1,2-DCP. The experimental results of and were fitted to Redlich–Kister equation to correlate the composition dependence of both excess properties. In this work, the experimental excess enthalpy data have been also correlated using thermodynamic models (Wilson, NRTL, and UNIQUAC) and have been qualitatively discussed.  相似文献   

9.
Densities and dynamic viscosities for methanol or ethanol with water, ethyl acetate, and methyl acetate at several temperatures T = (293.15, 298.15, and 303.15) K have been measured over the whole composition range and 0.1 MPa, along with the properties of the pure components. Excess molar volumes, viscosity deviations, and excess free energy of activation for the binary systems at the above-mentioned temperatures, were calculated and fitted to the Redlich-Kister equation to determine the fitting parameters and the root-mean-square deviations. UNIQUAC equation was used to correlate the experimental viscosity data. The UNIFAC-VISCO method and ASOG-VISCO method, based on contribution groups, were used to predict the dynamic viscosities of the binary mixtures.  相似文献   

10.
Excess molar volume, changes of refractive index, and surface tension deviations of binary mixtures of 1,2-ethanediol+1-propanol or 1-butanol have been determined at 293.15, 298.15, 303.15, and 308.15 K. The experimental data of refractive indices and surface tensions were compared with those predicted by different empirical expressions.  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.
The ternary systems 1,1-dimethylethoxy-butane (BTBE) + methanol + water and BTBE + ethanol + water have large heterogeneous zones. Experimental densities, refractive indices and speeds of sound have been measured at 298.15 K for mixtures of these systems within the homogeneous zone, and also for methanol + BTBE and ethanol + BTBE binary systems over the entire range of compositions. Excess molar volumes and molar refraction and isentropic compressibility changes of mixing were calculated from the experimental physical properties and were satisfactorily correlated with the corresponding composition data using the Redlich-Kister polynomial. Fitted coefficients and mean standard deviations of correlations have been reported.  相似文献   

13.
14.
15.
Densities and viscosities for the four binary liquid mixtures of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate with hexane-1-ol at temperatures 303.15 and 313.15 K and at atmospheric pressure were measured over the entire composition range. These values were used to calculate excess molar volumes and deviation in viscosities which were fitted to Redlich–Kister polynomial equation. Recently proposed Jouyban Acree model was also used to correlate the experimental values of density and viscosity. The mixture viscosities were correlated by several semi-empirical approaches like Hind, Choudhary–Katti, Grunberg–Nissan, Tamura and Kurata, McAllister three and four body model equations. A graphical representation of excess molar volumes and deviation in isentropic compressibility shows positive nature whereas deviation in viscosity shows negative nature at both temperatures for all four binary liquid mixtures. Positive values of excess molar volumes show that volume expansion is taking place causing rupture of H-bonds in self associated alcohols. The results were discussed in terms of molecular interactions prevailing in the mixtures.  相似文献   

16.
The molar excess enthalpies of 1,2- and 1,3-propanediamine + 1- or 2-propanol and 1,2- and 1,3-propanediol + 1- or 2-propaneamine have been determined at 298.15 K using a twin-microcalorimeter for a series of runs over the whole range of mole fractions. All excess enthalpies were large exothermic, in particular, the systems of amines + propanediols were more than −5 kJ mol−1 at the minimum. Primary or secondary alcohols and amines showed systematically different enthalpic behaviors. Equilibrium constant K1 expressed in terms of mole fractions and standard enthalpy of the formation of a 1:1 complex have been evaluated by ideal mixtures of momomeric molecules and their associated complexes.  相似文献   

17.
Excess molar enthalpies HEm of dimethylcarbonate, diethylcarbonate or propylene carbonate + trans-1,2-dichloroethylene, + trichloroethylene, and + tetrachloroethylene, respectively have been determined at 298.15 K using an LKB flow-microcalorimeter. Experimental data have been correlated by means of the Redlich-Kister equation and adjustable parameters have been evaluated by least-squares analysis. The HEm values range from a minimum value of − 1000 J mol−1 for diethylcarbonate + trans-1,2-dichloroethylene up to a maximum of 920 J mol−1 for dimethylcarbonate + tetrachloroethylene. For each series of mixtures, a systematic increase in HEm with an increase in the number of Cl atoms in the chloroalkene molecule has been noted. The results are discussed in terms of the molecular interactions.  相似文献   

18.
Measurements of densities, speeds of sound, excess volumes and viscosities of binary mixture of methyl tert-butyl ether with tetralin and decalin are reported at 303.15?K over the entire range of composition. Excess volumes are measured using batch dilatometer technique. Sound speeds are obtained using ultrasonic interferometer. Densities are computed from excess volume data. Isentropic compressibilities are derived from density and sound speed data. Speeds of sound are evaluated on the basis of Jacobson's free length theory and Schaff's collision factor theory. The predicted values are in good agreement with the experimental results. The viscosity data are analysed on the basis of corresponding states approach. Excess volumes and deviation in isentropic compressibilities are negative and deviation in viscosities are positive over the entire composition range. The experimental results are discussed in terms of possible molecular interactions between unlike molecules.  相似文献   

19.
20.
Excess molar enthalpies HE have been measured for liquid binary mixtures of 2,2′-oxybis[propane] (diisopropylether ‘DIPE’), or, benzene + butan-1-ol, +2-methylpropan-1-ol (isobutanol), +2-methyl-2-ene-1-propanol (isobutenol), +n-heptane at 303.15 K and constant pressure using a C80, Setaram calorimeter. A Redlich–Kister type equation was used to correlate experimental results.  相似文献   

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