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1.
Experimental values of density, refractive index and speed of sound of (hexane  +  cyclohexane  +  1-butanol) were measured at T =  298.15 K and atmospheric pressure. From the experimental data, the corresponding derived properties (excess molar volumes, changes of refractive index on mixing and changes of isentropic compressibility) were computed. Such derived values were correlated using several polynomial equations. Several empirical methods were used in the calculation of the properties of ternary systems from binary data. The Nitta–Chao group contribution model was applied to predict excess molar volume for this mixture.  相似文献   

2.
Density values for dilute aqueous solutions of five cyclic ethers (oxolane, 1,3-dioxolane, oxane, 1,4-dioxane, and 1,3,5-trioxane) are presented together with partial molar volumes at infinite dilution calculated from the experimental results. The measurements were performed at temperatures from (298 up to 573) K. Due to thermal decomposition, the upper temperature limit was lower for 1,3-dioxolane (448 K) and 1,3,5-trioxane (498 K). Experimental pressures were close to the saturated vapour pressure of water, and (15 and 30) MPa. The results were obtained using a high-temperature high-pressure flow vibrating-tube densimeter. Experimental standard partial molar volumes were correlated as a function of temperature and pressure using an empirical polynomial function and the semi-theoretical SOCW equation of state. Contributions of the group contribution method proposed previously were also evaluated and analyzed.  相似文献   

3.
Density data for dilute aqueous solutions of 1,2-ethanediol (ethylene glycol), 1,2-propanediol, 1,3-propanediol, and 1,2,3-propanetriol (glycerol) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298.15 K up to T = 573.15 K and at pressure close to the saturated vapour pressure of water, at pressures close to p = 20 MPa and p = 30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

4.
Density data for dilute aqueous solutions of two diols (1,6-hexanediol, 2,2-dimethyl-1,3-propanediol) and two polyhydric alcohols (2,2-bis(hydroxymethyl)-1,3-propanediol, 1,2,3,4,5-pentanepentaol) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to T = 573 K and at pressure close to the saturated vapour pressure of water, at pressures between 15 and 20 MPa and at p = 30 MPa. While temperature dependences of partial molar volumes of both diols are monotonous, maxima are observed on the curves for polyhydric alcohols. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

5.
Density data for dilute aqueous solutions of 1-butanol, 2-butanol, 2-methyl-1-propanol (iso-butanol), and 2-methyl-2-propanol (tert-butanol) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298.15 K up to T = 573.15 K and at pressure close to the saturated vapour pressure of water, at pressures close to p = 20 MPa and p = 30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

6.
Density values for dilute aqueous solutions of five cyclic ethers obtained using the Anton Paar DSA 5000 vibrating-tube densimeter and the laboratory-made flow densimeter are presented together with partial molar volumes at infinite dilution (standard partial molar volumes) calculated from the measured results. The cyclic ethers were either five-members cycles with one or two oxygen atoms (oxolane, 1,3-dioxolane) or six-members cycles with one, two, or three oxygen atoms (oxane, 1,4-dioxane, 1,3,5-trioxane). The measurements were performed at temperatures from T = 278 K up to T = 373 K and at either atmospheric pressure or at p = 0.5 MPa. The group contribution method is proposed and values of group contributions are evaluated. Standard partial molar volumes predicted for several other cyclic ethers including large cycles (crown ethers) are compared with available data from the literature.  相似文献   

7.
Density data for dilute aqueous solutions of two aliphatic ketones (3-pentanone, 2,4-pentanedione) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to either T = 573 K (3-pentanone) or T = 498 K (2,4-pentanedione) and at pressure close to the saturated vapour pressure of water, at pressures between 15 MPa and 20 MPa and at p = 30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

8.
The excess molar volumes and the partial molar volumes for (propionitrile + an alkanol) at T = 298.15 K and at atmospheric pressure are reported. The hydrogen bonding between the OH⋯NC groups are discussed in terms of the chain length of the alkanol. The alkanols studied are (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 1-pentanol).The excess molar volume data was fitted to the Redlich–Kister equation The partial molar volumes were calculated from the Redlich–Kister coefficients.  相似文献   

9.
The densities of {water (1) + tert-butanol (2)} binary mixture were measured over the temperature range (274.15 to 348.15) K at atmospheric pressure using “Anton Paar” digital vibrating-tube densimeter. Density measurements were carried out over the whole concentration range at (308.15 to 348.15) K. The following volume parameters were calculated: excess molar volumes and thermal isobaric expansivities of the mixture, partial molar volumes and partial molar thermal isobaric expansivities of the components. Concentration dependences of excess molar volumes were fitted with Redlich–Kister equation. The results of partial molar volume calculations using four equations were compared. It was established that for low alcohol concentrations at T ? 208 K the inflection points at x2  0.02 were observed at concentration dependences of specific volume. The concentration dependences of partial molar volumes of both water and tert-butanol had extremes at low alcohol content. The temperature dependence of partial molar volumes of water had some inversion at х2  0.65. The temperature dependence of partial molar volumes of tert-butanol at infinite dilution had minimum at ≈288 K. It was discovered that concentration dependences of thermal isobaric expansivities of the mixture at small alcohol content and low temperatures passed through minimum.  相似文献   

10.
Density data for dilute aqueous solutions of four aliphatic ethers (2,5-dioxahexane, 3,5-dioxaheptane, 3,6-dioxaoctane, and 2,5,8-trioxanonane) and one ether-alcohol (3,6-dioxa-1-heptanol) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to either T = 443 K (3,5-dioxaheptane) or T = 573 K (other solutes) and at pressures close to the saturated vapour pressure of water, at pressures between 15 and 20 MPa and at p = 30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

11.
New measurements are reported for the densities of choline chloride: urea (REL) deep eutectic solvent and its aqueous mixtures over the temperature range (298.15 to 323.15) K and pressures up to 50 MPa. The experimental data were used to derive other properties such as isothermal compressibility, isobaric expansivity and excess molar volume. A Tait-type equation was used to correlate accurately the high-pressure density data to temperature, T, pressure, P, and composition, x. The excess molar volumes of {REL (1) + H2O (2)} mixtures were also investigated and represented as a function of all three variables, T, P, x, using an empirical equation. Results indicate that the correlations used in this work can be satisfactorily used to predict the densities of the studied systems at different conditions of temperature, pressure and composition.  相似文献   

12.
Vapour pressures of (tetrahydrofuran + 1,1,2,2-tetrachloroethane, or tetrachloroethene) at nine temperatures between T = 283.15 K and T = 323.15 K were measured by a static method. The reduction of the vapour pressures data to obtain activity coefficients and excess molar Gibbs energies was carried out by fitting the vapour pressure data to the Redlich–Kister polynomial according to Barker’s method. Excess molar volumes were also measured at T = 298.15 K. A comparative analysis about the thermodynamic behaviour of both systems is performed, in terms of hydrogen bonding and electron-donor–acceptor interactions, as well as the resonance effect in tetrachloroethene.  相似文献   

13.
Excess molar enthalpies and excess molar volumes at T =  298.15 K andp =  0.1 MPa are reported for (methanol, or ethanol, or 1-propanol  +  1,4-dicyanobutane, or butanenitrile, or benzonitrile). For all the mixtures investigated in this work the excess molar enthalpy is large and positive. The excess molar enthalpy decreases as the carbon chain number of the alkanol species increases from methanol to propanol. The excess molar volumes are both positive and negative. The Extended Real Associated Solution and the Flory–Benson–Treszczanowicz models were used to represent the data. Both these models describe better the excess molar enthalpy than the excess molar volumes of (an alkanol  +  a nitrile compound).  相似文献   

14.
Densities, speeds of sound, and refractive indices of 12 binary systems of alkanes (hexane, heptane, octane, and nonane) with aromatics (benzene, or toluene, or ethylbenzene) at T = 313.15 K and at atmospheric pressure were determined over the whole composition range, and are presented in this paper. From the experimental results, the derived and excess properties (isentropic compressibility, excess molar volumes, and excess molar isentropic compressibility) at T = 313.15 K were calculated and satisfactorily fitted to the Redlich–Kister equation.  相似文献   

15.
The (p, ρ, T) properties and apparent molar volumes Vϕ of CaCl2 in methanol at T = (298.15 to 398.15) K, at pressures up to 40 MPa are reported, and apparent molar volumes have been evaluated. The experimental (p, ρ, T) values were described by an equation of state. The experiments were carried out at m = (0.10819, 0.28529, 0.65879 and 2.39344) mol · kg−1 of calcium chloride.  相似文献   

16.
Experimental excess molar enthalpies of the ternary systems {dibutyl ether (DBE) + 1-butanol + heptane} and the corresponding binary systems at T = 298.15 K and T = 313.15 K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary and the ternary systems show endothermic character. The experimental data for the binary and ternary systems have been fitted using the Redlich–Kister equation, the NRTL and UNIQUAC models. The values of the standard deviation indicate good agreement between the experimental results and those calculated from the equations.  相似文献   

17.
Experimental values of density, viscosity, and refractive index at T = (298.15, 303.15, and 308.15) K while the speed of sound at T = 298.15 K in the binary mixtures of methylcyclohexane with n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-dodecane, and iso-octane are presented over the entire mole fraction range of the binary mixtures. Using these data, excess molar volume, deviations in viscosity, molar refraction, speed of sound, and isentropic compressibility are calculated. All the computed quantities are fitted to Redlich and Kister equation to derive the coefficients and estimate the standard error values. Such a study on model calculations in addition to presentation of experimental data on binary mixtures are useful to understand the mixing behaviour of liquids in terms of molecular interactions and orientational order–disorder effects.  相似文献   

18.
Density ρ, viscosity η, and refractive index nD, values for (tetradecane + benzene, + toluene, + chlorobenzene, + bromobenzene, + anisole) binary mixtures over the entire range of mole fraction have been measured at temperatures (298.15, 303.15, and 308.15) K at atmospheric pressure. The speed of sound u has been measured at T = 298.15 K only. Using these data, excess molar volume VE, deviations in viscosity Δη, Lorentz–Lorenz molar refraction ΔR, speed of sound Δu, and isentropic compressibility Δks have been calculated. These results have been fitted to the Redlich and Kister polynomial equation to estimate the binary interaction parameters and standard deviations. Excess molar volumes have exhibited both positive and negative trends in many mixtures, depending upon the nature of the second component of the mixture. For the (tetradecane + chlorobenzene) binary mixture, an incipient inversion has been observed. Calculated thermodynamic quantities have been discussed in terms of intermolecular interactions between mixing components.  相似文献   

19.
Density, speed of sound and refractive index values of (diethyl carbonate  + n -decane), were measured at the temperatures (288.15, 293.15, 298.15, and 308.15) K and atmospheric pressure. In addition, dielectric permittivities have been measured for the same mixture and at the same temperatures except at T =  293.15 K. Excess molar volumes, changes of isentropic compressibility on mixing, changes of refractive index on mixing and changes of dielectric permittivity on mixing were computed from the experimental data. The excess molar volumes were compared with predictions from the Nitta–Chao model.  相似文献   

20.
Densities, speeds of sound and refractive indices have been measured for (n -hexane  +  cyclohexane  +  1-hexanol) and its corresponding binaries atT =  298.15 K. In addition, ideal isentropic compressibilities were calculated from the speeds of sound, densities, and literature heat capacities and cubic expansion coefficients. The excess molar volumes and excess isentropic compressibilities, and deviations of the speed of sound and refractive index are correlated by polynomials and discussed.The Nitta–Chao model was used to estimate binary and ternary excess molar volumes, and several empirical equations were also used to calculate the excess and deviation properties.  相似文献   

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