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1.
《Fluid Phase Equilibria》1999,155(2):261-276
The excess isentropic compressibilities, KsE for seven binary mixtures of methyl methacrylate+benzene, +o-xylene, +m-xylene, +p-xylene, +toluene, +ethylbenzene and +cyclohexane were estimated from the measured densities and speeds of sound at 298.15 and 308.15 K. The KsE values were large and positive for MMA+cyclohexane and +m-xylene, while they were negative for other mixtures. A qualitative analysis of KsE values was made in terms of molecular interactions. The speeds of sound of all the mixtures were also predicted from the free length theory (FLT) and collision factor theory (CFT).  相似文献   

2.
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   

3.
Abstract

Ultrasonic sound velocities and densities were measured for the binary mixtures of p-chlorotoluene with l-alcohols. The alcohols included: l-propanol, l-butanol, l-pentanol, l-hexanol and l-heptanol. Isentropic compressibilities, ks and deviation in isentropic compressibility, Ks from ideal behaviour have been calculated from the results. The deviation in isentropic compressibility has been ascribed to competition between structure-breaking and structural effects to different extents.  相似文献   

4.
    
Ultrasonic sound velocities and densities of binary mixtures of 1-bromobutane with propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol, heptan-1-ol and octan-l-ol have been experimentally determined at 303·15 K. Isentropic compressibilities (K s) and deviations in isentropic compressibilities (ΔK S) have been calculated from the results. The values of ΔKS are almost positive over the entire range of composition in all six binary liquid mixtures. The experimental results are explained in terms of depolymerisation of hydrogen-bonded alcohol aggregates, decrease in dipolar association and weak hydrogen-bonding interaction of the type Br---H-O between unlike molecules.  相似文献   

5.
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   

6.
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   

7.
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   

8.
Excess volumes (v^E), ultrasonic velocities (u), isentropic compressibility (△Ks) and viscosities (η) for the binary mixtures of dimethyl formamide (DMF) with 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,2,4-trichlorobenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-nitrotoluene and m-nitrotoluene at 303.15 K were studied. Excess volume data exhibit an inversion in sign for the mixtures of dimethyl formamide with 1,2- and 1,3-dichlorobenzenes and the property is completely positive over the entire composition range for the mixtures of dimethyl formamide with 1,2,4-trichlorobenzene, o-nitrotoluene and m-nitrotoluene. On the other hand, the quantity is negative for the mixtures of dimethyl formamide with chlorotoluenes. Isentropic compressibility (Ks) has been computed for the same systems from precise sound velocity and density data. Further, deviation of isentropic com- pressibility (△Ks) from ideal behavior was also calculated. AKs values are negative over the entire volume fraction range in all the binary mixtures. The experimental sound velocity data were analysed in terms of Free Length Theory (FLT) and Collision Factor Theory (CFT). The viscosity data were analysed on the basis of corresponding state approach. The measured data were discussed on the basis of intermolecular interactions between unlike molecules.  相似文献   

9.
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   

10.
《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   

11.
Ultrasonic velocities have been determined for binary mixtures of pyridine + n-alkanol (C1-C10) over the whole composition range at 25‡C. The excess isentropic compressibilities K S E and apparent molar isentropic compressibilities KΦ,s are estimated from these measurements. The K S E values are negative for all the systems over the complete mole fraction range except pyridine + decanol for which small positive values are obtained. The standard partial molar isentropic compressibilitiesK‡ of the alkanols are positive and increase linearly with the chain length of the alkanol molecules. It indicates that a methylene functional group makes a positive contribution to the expansion coefficient of a solute in these mixtures.  相似文献   

12.
Densities (ρ), speeds of sound (u) and refractive indices (nD ), of the ternary mixture (diethylcarbonate + p-chloroacetophenone + 1-hexanol) and the involved binary mixtures (diethylcarbonate + p-chloroacetophenone, diethylcarbonate + 1-hexanol, and p-chloroacetophenone + 1-hexanol) have been measured over the whole composition range at 303.15 K for the liquid region and at ambient pressure. The data obtained are used to calculate isentropic compressibilities ks , isentropic compressibility deviations Δks and refractive index deviations ΔnD , of the binary and ternary mixtures. The data of isentropic compressibility deviations and refractive index deviations of the binary systems were fitted to the Redlich–Kister equation while the best correlation method for the ternary system was found using the Cibulka equation. The experimental data of the constitute binaries and ternaries are analysed to discuss the nature and strength of intermolecular interactions in these mixtures.  相似文献   

13.
Excess molar volumes, excess molar enthalpies and speeds of sound of 1-methyl pyrrolidin-2-one?+?o- or m- or p-xylene binary mixtures have been measured over the entire composition range at 308.15?K. The speed of sound data were used to determine the excess isentropic compressibilities. It is observed that while the values of the excess molar enthalpies for the investigated mixtures are positive, the values of the excess molar volumes and excess isentropic compressibilities are negative over the entire composition range. The measured thermodynamic data have been analyzed in terms of Graph, Prigogine?CFlory?CPatterson, and the Sanchez and Lacombe theories. It is observed that Graph theory correctly predicts the signs and magnitudes of the excess molar volumes, excess molar enthalpies, and excess isentropic compressibilities of the studied mixtures. However, the excess molar volumes, excess molar enthalpies and excess isentropic compressibilities predicted by Prigogine?CFlory?CPatterson and Sanchez and Lacombe theories are of same sign.  相似文献   

14.
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   

15.
The ultrasonic sound velocities and densities are measured for the binary mixtures of N-methyl-2-pyrrolidone (NMP) with ketones and branched alcohols at 303.15?K. The ketones include methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isobutyl ketone and cyclohexanone. The branched alcohols include 2-propanol, 2-methyl-1-propanol, 3-methyl-1-butanol, 2-butanol and 2-methyl-2-propanol. The ultrasonic sound velocity data were used to compute isentropic compressibilities (k s). The deviations in the value of k s from ideal value were computed. Except cyclohexanone all the binary mixtures formed by NMP with ketones at 303.15?K exhibit negative deviation from ideal behaviour over the entire range of composition. Cyclohexanone with NMP exhibit positive deviation over the entire range of composition. An inversion in the sign of Δk s from positive to negative was observed for 2-propanol system and negative deviation was observed in four binary mixtures formed by NMP with other branched alcohols at 303.15?K. The ultrasonic sound velocities of these mixtures have been analysed is terms of Free Length Theory (FLT), Collision Factor Theory (CFT) and Nomoto's relation.  相似文献   

16.
    
The density of poly(2-methoxy)cyanurate of l,l−bis(3-methyl-4-hydroxy phenyl)cyclohexane [PCMBC] is determined by partial specific volume and floatation methods at 33° ± 0.l°C and compared with calculated values. Acoustical parameters such as viscosity (η), sound velocity (U), isentropic compressibilities (K s ), Rao’s molar sound function (R), specific acoustical impedance (Z), solvation numbers (Sn), van der Waals constant (b) and relaxation strength (r) of PCMBC in two different solvents like chloroform (CF) and 1,2-dichloroethane (DCE) at 31°C are evaluated at different concentrations. The linear relationships of these parameters with the concentrations have been observed except the π vs concentration plots where upward curvature is observed after l.5g/dl indicating structural changes. The linear relationships indicate solvent-solute interactions.  相似文献   

17.
Speeds of sound, uijk, of 1,3-dioxolane or 1,4-dioxane (i) + water (j) + formamide or dimethylformamide (k) ternary mixtures and of their binary subsystems, uij, of 1,3-dioxolane or 1,4-dioxane (i) + formamide or dimethylformamide (j), and water (i) + formamide or dimethylformamide (j) have been measured over the entire composition range at 308.15 K. The experimental data have been used to evaluate the excess isentropic compressibilities of binary (κsE)ij and ternary (κsE)ijk mixtures using their densities calculated from molar excess volume data. The Moelwyn-Huggins concept [M. L. Huggins, Polymer 12, 389 (1971)] of interaction between the surfaces of components of a binary mixture has been employed to evaluate the excess isentropic compressibilities (using the concept of connectivity parameter of third degree of a molecule, 3ξ, which in turn depends on its topology) of binary mixtures, and this method has been extended to predict excess compressibilities of ternary mixtures. Values of (κsE)ij and (κsE)ijk have also been calculated by the Flory theory. It was observed that (κsE)ij and (κsE)ijk predicted by the Moelwyn-Huggins approach compare well with calculated and experimental values.  相似文献   

18.
The densities ρ, speeds of sound u, and viscosities η, of pure 1-butanol, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene, and tetrachloroethylene and those of their binary mixtures have been measured at 298.15 K and atmospheric pressure over the entire range of compositions. Excess molar volumes V E, viscosity deviations Δη, deviation in compressibilities Δκs and excess Gibbs energy of activation G*E, were obtained from the experimental results and those were fitted to Redlich–Kister's type function in terms of mole fractions. Viscosities, speeds of sound and isentropic compressibilities of the binary mixtures have been correlated by means of several empirical and semi-empirical equations. The experimental data are analysed to discuss the nature and strength of intermolecular interactions in these mixtures.  相似文献   

19.
The partial molar isentropic compressibilities at infinite dilution, KS,2, have been determined for several tripeptides of the sequence glycyl-X-glycine, where X is one of the amino acids tyrosine, proline, glutamine, aspartic acid, glutamic acid and lysine in aqueous solution at 25 C. These results, along with those for triglycine, were used to estimate the contributions of the amino acid side-chains to the partial molar isentropic compressibilities of polypeptides. Values for KS,2 have also been determined for aqueous solutions of the two peptide salts K[glyaspgly] and Na[glyglugly]. The KS,2 results for the peptides and their salts have been combined with literature data for electrolytes to calculate the changes in isentropic compressibility upon ionization of the acidic side-chains. The results are compared with those for other carboxylic acid systems.  相似文献   

20.
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   

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