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1.
《Fluid Phase Equilibria》1996,118(2):227-240
Densities, ϱ, and speeds of sound, u, have been measured for the ternary mixture {benzene + cyclohexane + hexane} and the corresponding binary mixtures {benzene + cyclohexane}, {benzene + hexane} and {cyclohexane + hexane}, at the temperature 298.15 K. Using these results, the isentropic compressibilities, κs, the excess isentropic compressibilities, κsE, and the speeds of sound deviations, Δu, have been calculated for both the binary mixtures and the ternary system. Excess isentropic compressibilities, κsE, and the speeds of sound deviations, Δu, have been fitted to the Redlich-Kister equation in the case of binary mixtures, while the equation of Cibulka was used to fit the values relating to the ternary system. The empiric equations of Redlich-Kister, Tsao-Smith, Kohler and Colinet have been applied in order to predict the κsE and Δu of ternary mixtures from the binary contributions.  相似文献   

2.
The densities ρ, dynamic viscosities η, speeds of sound u, and relative permittivities εr, for (dibutyl ether + benzene, or toluene, or p-xylene) have been measured at different temperatures over the whole composition range and at atmospheric pressure. The mixture viscosities have been correlated with semi empirical equations. Calculations of the speed of sound based on Nomoto’s equation have been found to be close to experimental values for the three mixtures and at two temperatures. Excess functions such as excess molar volumes VmE, excess isentropic compressibilities κsE, deviations in relative permittivities δεr, and molar polarizations δPm were calculated and fitted to Redlich–Kister type equations.  相似文献   

3.
The densities (ρ), ultrasonic speeds (ν), and refractive indices (n) of binary mixtures of styrene (STY) with m-, o-, or p-xylene, including those of their pure liquids, were measured over the entire composition range at the temperatures 298.15, 303.15, 308.15, and 313.15 K. The excess volumes (VE), deviations in isentropic compressibilities (Δks), acoustic impedances (ΔZ), and refractive indices (Δn) were calculated from the experimental data. Partial molar volumes (V0?,2) and partial molar isentropic compressibilities (K0?,2) of xylenes in styrene have also been calculated. The derived functions, namely, VE, Δks, ΔZ, Δn, V0?,2, and K0?,2 were used to have a better understanding of the intermolecular interactions occurring between the component molecules of the present liquid mixtures. The variations of these parameters suggest that the interactions between styrene and o-, m-, or p-xylene molecules follow the sequences: p-xylene>o-xylene>m-xylene. Apart from using density data for the calculation of VE, excess molar volumes were also estimated using refractive index data. Furthermore, several refractive index mixing rules have been used to estimate the refractive indices of the studied liquid mixtures theoretically. Overall, the computed and measured data were interpreted in terms of interactions between the mixing components.  相似文献   

4.
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   

5.
Densities, viscosities and speeds of sound of binary mixtures of ethyl benzoate with cyclohexane, n-hexane, heptane and octane have been measured over the entire range of composition at (303.15, 308.15 and 313.15) K and at atmospheric pressure. From these experimental values, excess molar volume (V E), deviation in viscosity (Δη) and deviation in isentropic compressibility (ΔK s) have been calculated. The viscosities of binary mixtures were calculated theoretically from the pure component data by using various empirical and semi-empirical relations and the results compared with the experimental findings.  相似文献   

6.
The speed of sound, Uij 1,3-dioxolane (D) in binary mixtures (ij) with benzene, cyclohexane, n-hexane or n-heptane and Uijk for 1,3-dioxolane in ternary mixtures (ijk) with the same hydrocarbons have been measured as a function of composition at 298.15 K. The observed data have been utilised to evaluate excess isentropic compressibility of binary, (κsE)ij and ternary (κsE)ijk mixtures using density and speed of sound values of the binary and ternary mixtures. The Moelyn-Huggins concept of interaction between the molecular surfaces of the components of a binary mixture [Polymer 12 (1971) 389] has been extended to evaluate excess isentropic compressibility of the studied binary and ternary mixtures. It has been observed that κsE values predicted by a graph-theoretical approach using connectivities of third degree for binary mixtures compare reasonably well with their corresponding experimental values and κsE for ternary mixtures are of the same sign and order of magnitude.  相似文献   

7.
Excess molar volumes (VE) and ultrasonic sound velocities at T = 303.15 K and ambient pressure have been measured as a function of composition for the binary liquid mixtures of dimethylsulphoxide (DMSO) with ketones. The ketones studied in the present investigation include ethyl methyl ketone (EMK), diethylketone (DEK), methyl propyl ketone (MPK), methyl isobutyl ketone (MIBK), and cyclohexanone (CH). The VE values were measured using a dilatometer and were positive over the entire mole fraction range for all systems except in the binary system DMSO with EMK where the VE exhibits an inversion in sign. The experimental VE values have been correlated using Redlich–Kister and Hwang et al. equations. The ultrasonic sound velocities for the above systems have been measured with a single crystal interferometer at a frequency of 3 MHz. The sound velocity (u) data have been used to calculate isentropic compressibility (Ks) and deviation in isentropic compressibility (ΔKs) over the entire range of volume fraction. The sound velocity data have been predicted in terms of free length theory (FLT), collision factor theory (CFT), and Nomoto relation. The results reveal that all the theories gave a satisfactory estimate of the sound velocity. The deviations in values of isentropic compressibility (ΔKs) were negative over the entire range of volume fraction in all the binary liquid mixtures. The results are interpreted with respect to possible molecular interactions between components.  相似文献   

8.
Excess molar volumes (VE) and ultrasonic studies at T = 303.15 K and atmospheric pressure have been measured over the whole composition range for the binary mixtures of N-methyl-2-pyrrolidone (NMP) with ketones. The ketones studied in the present investigation include methyl ethyl ketone (MEK), diethylketone (DEK), methyl propyl ketone (MPK), methyl isobutyl ketone (MIBK), and cyclohexanone (CH). The VE values were measured using a dilatometer and were negative over the entire mole fraction range for NMP with MEK, DEK, MPK, and MIBK and were positive for NMP with CH. The ultrasonic sound velocities for the above systems were measured with a single crystal interferometer at a frequency of 3 MHz. The sound velocity (u) results have been used to calculate isentropic compressibility (Ks) and deviation in isentropic compressibility (ΔKs) over the entire range of volume fraction. The sound velocity results have been predicted in terms of free length theory (FLT), collision factor theory (CFT), and Nomoto relation. The results reveal that all the theories gave a satisfactory estimate of the sound velocity. The deviation values of the isentropic compressibilities (ΔKs) were negative over the entire range of volume fraction in all the binary liquid mixtures except in the binary system NMP with CH, where we observed positive ΔKs values. The results are interpreted on possible molecular interactions between components.  相似文献   

9.
Abstract

New experimental sound velocity and density data for binary mixtures of N-methyl-cyclohexylamine with benzene, toluene, o-xylene, m-xylene, p-xylene, chlorobenzene, bromobenzene and nitrobenzene at 303.15K have been reported. The sound velocity data were also used to compute the isentropic compressibilities (Ks ). The deviation in isentropic compressibilities (ΔKs ) from ideal behaviour suggests that the existence of weak dipole-induced dipole and dipole-dipole interactions between unlike molecules.  相似文献   

10.
Speeds of sound u at the temperature 298.15 K for six ( n -alkoxyethanol  +  toluene) were measured over the whole composition range. The n -alkoxyethanols were 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, and 2-(2-butoxyethoxy)ethanol. Excess molar volumes VmE atT =  298.15 K were also measured for the mixtures of toluene and 2-methoxyethanol, 2-ethoxyethanol, or 2-butoxyethanol over the whole composition range. The speed of sound values were combined with excess molar volumes to obtain values for the product KS, m of the molar volume and the isentropic compressibilityκS , and the corresponding excess quantities KS,mE were also calculated. The KS,mE curves are sigmoid for all mixtures. The deviations of the speeds of sounduD from their values uid in an ideal mixture were obtained for all measured mole fractions. These values are compared with the mixing function δu calculated in the paper. The behaviour ofu , uD, δu, and KS,mE as a function of composition and number of carbon atoms in the aliphatic chain of the alkoxyethanol is discussed. Also, theoretical values of the molar isentropic compressibility KS,m and speed of sound u were calculated using the Prigogine-Flory-Patterson theory with a van der Waals potential energy model and the results compared with experimental data.  相似文献   

11.
Speeds of sound have been measured in liquid mixtures of cyclopentane with 1-propanol, with 1-pentanol, and with 1-heptanol across the entire composition range at temperatures of (298.15, 308.15 and 318.15) K and atmospheric pressure. The experimental speed of sound data were used to estimate the isentropic compressibility κ S for all mixtures. The molar volumes were multiplied by the corresponding isentropic compressibilities to obtain estimates of the molar compressibilities K S,m. The corresponding KS,mEK_{S,\mathrm{m}}^{\mathrm{E}} values have also been calculated. Theoretical values of the speeds of sound were estimated using theories and empirical relations. Deviations of the speed of sound, u D, from the values calculated by different approaches for ideal mixing have been obtained for all mole fractions.  相似文献   

12.
Molar excess volumes VEijk of methylenebromide i + pyridine j + β-picoline (k, cyclohexane (i) + pyridine (j) + β-picoline(K), benzene(i)+toluene(j)+1,2-dichloroethane(k), benzene(i) + 0-xylene(j) + 1,2-dichloroethane(k) and benzene(i) + p-xylene(j) + 1,2-dichloroethane(k) mixtures have been determined dilatometrically at 298.15 K. The data have been examined in terms of Sanchez and Lacombe theory and the graph-theoretical approach, and it is found that they are described well by the latter. Self- and cross-volume interaction coefficients Vjk, Vjjk and Vjkk, etc., have also been evaluated and the values utilised to study molecular interactions between the jth and kth molecular species in the presence of the ith in these i + j + k mixtures.  相似文献   

13.
Excess volumes of mixing, VE, for binary mixtures of 1,2-dichloroethane with benzene, toluene, o?, m?, and p-xylenes have been determined at 308.15 K over the complete composition range. VE is positive for all these mixtures and varies in the order m-xylene >o-xylene >p-xylene > benzene > toluene. The experimental data have been analyzed in terms of the Prigogine's average potential cell model coupled with Balescu's theory. The calculated VE values do not agree with the corresponding experimental values.  相似文献   

14.
The densities (ρ) and viscosities (η) for the ternary liquid mixtures of water + N,N-dimethylformamide + monoalkanols, have been measured as a function of the composition at 298.15, 308.15, and 318.15 K. From the experimental measurements excess molar volumes (V E), Viscosity deviation (Δη), and synergy index (I s) have been evaluated. The speeds of sound have been also measured and excess isentropic compressibilities (K sE) are calculated al 298.15 K. The results are discussed and interpreted in terms of molecular package and specific interaction predominated by hydrogen bonding, been investigated.  相似文献   

15.
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   

16.
《Fluid Phase Equilibria》2004,215(1):61-70
Isentropic compressibilities κS, and excess isentropic compressibilities κSE have been determined from measurements of speeds of sound u and densities ρ of 14 binary mixtures of triethylamine (TEA) and tri-n-butylamine (TBA) with n-hexane, n-octane, iso-octane, n-propylamine, n-butylamine, n-hexylamine and n-octylamine. The relative magnitude and sign of κSE have been interpreted in terms of molecular interactions and interstitial accommodation. The values of κSE for TEA + alkane are positive while for TBA + alkane are negative. The values of κSE for TEA + primary amine become progressively less positive and eventually to negative with the increase in chain length of alkylamine. In case of TBA + primary amine, the values of κSE increase from n-propylamine to n-butylamine, and then decrease with chain length of primary amine. The experimental speeds of sound u have been analyzed in terms of collision factor theory, free length theory and Prigogine–Flory–Patterson statistical theory of solutions.  相似文献   

17.
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.  相似文献   

18.
Surface tensions of mixtures of 1,2-dibromoethane+cyclohexane, benzene, +toluene, +o-xylene, +m-xylene, and +p-xylene have been measured as a function of composition at 298.15, 303.15 and 308.15 K. Interchange energies and surface heats of mixing in these mixtures were computed.  相似文献   

19.
Molar excess volumes, VE, molar excess enthalpies, HE, and speeds of sound, u, of o-toluidine (i) + cyclohexane or n-hexane or n-heptane (j) binary mixtures have been determined over entire range of composition at 308.15 K. Speeds of sound data have been utilized to predict isentropic compressibility changes of mixing, of (i + j) mixtures. The observed VE, HE and data have been analyzed in terms of Graph theory. The analysis of VE data by Graph theory reveals that o-toluidine exists as an associated molecular entity and (i + j) mixtures contain 1:1 molecular complex. It has been observed that VE, HE and values calculated by Graph theory compare well with their corresponding experimental values. The observed data have also been analyzed in term of Flory theory.  相似文献   

20.
Speed of sound data, uijk, of 1,3-dioxolane or 1,4-dioxane(i) + water(j) + propan-1-ol or propan-2-ol(k) ternary mixtures and their sub-binary mixtures, uij, of 1,3-dioxolane or 1,4-dioxane(i) + water or propan-1-ol or propan-2-ol(j) and water(i) + propan-1-ol or propan-2-ol(j) mixtures have been measured over the entire composition range at 308.15 K. Isentropic compressibility changes of mixing, (κsE)ij and (κsE) ijk, for the binary and ternary mixtures have been determined by employing the observed speeds of sound data and densities (calculated from their molar excess volumes data). The (κsE) ij and (κsE) ijk values have also been predicated by the graph theoretical approach and the Flory theory. It has been observed that (κsE) ij and (κsE) ijk predicted by the graph theoretical approach compare well with their corresponding experimental values.  相似文献   

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