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1.
Densities and ultrasonic speeds of binary mixtures of benzaldehyde with n-hexane and cyclohexane at 30 °C were measured over the entire composition range. From these experimental data, the adiabatic compressibility (K S ), intermolecular free length (L f), acoustic impedance (Z), relative association (R a) and relaxation strength (r) were calculated. Also, the excess adiabatic compressibility (K S E), intermolecular free length (L fE), acoustic impedance (Z E), and ultrasonic velocity (U E) were calculated. The observed variation of these parameters helps in understanding the nature of interactions in these mixtures. Further, theoretical values of the ultrasonic speed were evaluated using theories and empirical relations. The relative merits of these theories and relations were discussed.  相似文献   

2.
Ultrasound velocity (u), density (ρ) and viscosity (η) measurements of benzaldehyde + ethylbenzene mixtures have been carried out at 303.15, 308.15, and 313.15 K. These values have been used to calculate the excess molar volume (V E), deviation in viscosity (δη), and deviation in isentropic compressibility (δβs), deviations in ultrasound velocity (δu), excess free volume (δV f), excess intermolecular free length (δL f) and excess Gibbs free energy of activation of viscous flow (δG E). McAllister’s three body interaction model is used for correlating kinematic viscosity of binary mixtures. The excess values were correlated using the Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. The thermophysical properties under the study were fit to the Jouyban-Acree model. The observed variation of these parameters helps in understanding the nature of interactions in these mixtures. Further, theoretical values of the ultrasound speed were evaluated using theories and empirical relations.  相似文献   

3.
Densities, and ultrasonic velocities, uof binary mixtures of N,N-dimethylformamide (DMF) + methanol, + ethanol, + 1-propanol, + 1-butanol, + 1-pentanol, and + 1-hexanol have been measured at 30°C. The ultrasonic velocities have been compared with values calculated from the free-length theory ( FLT) due to Jacobson and collision-factor theory ( CFT) due to Schaaffs. The measured data are used to compute adiabatic compressibility (k s), deviation in adiabatic compressibility (k s), intermolecular free length (L f), molar volume (V m), and available volume (V a). The excess molar volume ( V m E) and excess free length (L f E) are also evaluated. For all systems, these results were satisfactorily correlated by the Redlich–Kister polynomial. These parameters are used to discuss dissociation of the self-associated 1-alkanol molecules and the formation of aggregates between unlike molecules through C=O...H–O hydrogen bonding.  相似文献   

4.
Ultrasonic velocity, density and percentage deviation in velocity were measured for mixtures of n-alkanes, namely, n-octane, n-decane, n-dodecane and n-tetradecane with octan-2-ol at 298 K. The experimental sound velocity data were compared by using three theoretical relations, namely, Nomoto relation, Vandael ideal mixing relation and Schaaffs collision factor theory to predict which one of them agrees the experimental data. It was observed that Nomoto relation was the best suited method in all the four binary systems. Hence, in the real time applications which are using the above said components can be handled without experimental expenses. The experimental data were used to calculate the interaction parameter (α), adiabatic compressibility (β), intermolecular free length (Lf), excess velocity (UE), excess impedance (ZE) and excess volume (VE) which were discussed to identify the molecular interactions in terms of non-ideality in the binary liquid mixtures. It was observed that the increase of mole fraction of octan-2-ol with different n-alkanes dipole–induced dipole interactions were supported.  相似文献   

5.
Densities (ρ), viscosities (η), and speeds of sound, (u) of the binary mixtures of 2-propanol with n-alkanes (n-hexane, n-octane, and n-decane) were measured over the entire composition range at 298.15 and 308.15 K and at atmospheric pressure. Using the experimental values of density, viscosity and speed of sound, the excess molar volumes (V E), viscosity deviations (Δη), deviations in speed of sound (Δu), isentropic compressibility (κ s), deviations in isentropic compressibility (Δκ s), and excess Gibbs energies of activation of viscous flow (ΔG* E) were calculated. These results were fitted to the Redlich–Kister type polynomial equation. The variations of these excess parameters with composition were discussed from the viewpoint of intermolecular interactions in these mixtures. The excess properties are found to be either positive or negative depending on the molecular interactions and the nature of liquid mixtures.  相似文献   

6.
Abstract

The ultrasonic velocity, u, viscosity, η, and density, ρ of dimethylsulphoxide (DMSO), 1-butanol, 1-hexanol, 1-octanol, and of their binary mixtures, where DMSO is common component, have been measured at 303.15 K. From the experimental data, excess isentropic compressibility, K E s, excess intermolecular free length, LE f, excess velocity, u E, excess acoustic impedance, Z E, excess viscosity, ηE, excess free energy of activation of viscous flow, G?E, and excess rheochore, [R E] have been calculated. The behaviours of excess functions with composition of the mixtures suggest that the structure-breaking effect dominates over the interaction effect between the component molecules. Furthermore, the experimental values of u and η were fitted by empirical equations stating their dependence on composition of the mixtures. The experimental values of u have been compared with those calculated by using Nomoto and Van Dael relations.  相似文献   

7.
Mixed solvents rather than single pure liquids are of utmost practical importance in chemical and industrial processes as they provide an ample opportunity for the continuous adjustment of desired properties of the medium. Therefore, ultrasonic velocity (u) and density (ρ) were measured for the binary mixtures formed by heptane with ethyl acetate or butyl acetate at temperatures 293, 298 and 303 K over the entire composition range. Deviation in ultrasonic velocity (Δu), deviation in isentropic compressibility (Δκs), and excess intermolecular free length (LEf) have been evaluated using the ultrasonic velocity data and the computed results were fitted to the Redlich‐Kister polynomial equation. The values of Δu, Δκs and LEf were plotted against the molar fraction of heptane. The observed positive and negative values of excess parameters were discussed in terms of molecular interaction between the components of the mixtures. Experimental values of ultrasonic velocity and density were compared with the results obtained by theoretical estimation procedures. The results were discussed in terms of average absolute deviation (AAD).  相似文献   

8.
The values of density, viscosity, and ultrasonic velocity for the binary liquid mixture of benzaldehyde with bromobenzene have been measured over the entire range of composition at 303.15, 308.15, and 313.15?K. These values have been used to calculate the excess molar volume (V E), deviation in viscosity (????), deviation in velocity (?U), deviation in isentropic compressibility (??? s), excess internal pressure (???), excess intermolecular free length (?L f), and excess acoustic impedance (?Z). McAllister??s three-body-interaction model is used for correlating kinematic viscosity of binary mixtures. The excess values were correlated using the Redlich?CKister polynomial equation to obtain their coefficients and standard deviations. The thermo-physical properties (density, viscosity, and ultrasonic velocity) under the study were fitted to the Jouyban?CAcree model.  相似文献   

9.
Acoustical and viscosity measurements have been made for binary liquid mixtures of commercially available solvent extractants, LIX reagents such as LIX 622 and LIX 860 in benzene, amyl alcohol, and tri-n-butyl phosphate (TBP) at 303.15 K. The measured values of ultrasonic velocity, density, and viscosity have been utilized to compute some acoustic as well as thermodynamic parameters such as intermolecular free length, L f, isentropic compressibility, s, molar volume, V, and Gibb's excess free energies of activation of viscous flow, G*E. These parameters along with the derived values of isentropic compressibility, s E, intermolecular free length, L f E, and molar volume, V E, have been utilized for a comparative study of molecular interactions between the components present in different liquid systems. The experimental ultrasonic velocities for aforementioned mixtures have been compared with theoretically estimated velocities using different empirical relations, and the relative merits of these theories and relations have been discussed in terms of percentage variation.  相似文献   

10.
Measurements of the ultrasonic velocity (u), density (ρ) and refractive index (n) for binary mixtures of polyethylene glycol 250 dimethyl ether with 1-propanol and 1-butanol have been made at three temperatures (T=293, 303 and 31 K) over the entire composition range in order to investigate the nature of intermolecular interactions between the components of these liquid mixtures. Various excess thermodynamic properties such as the excess ultrasonic velocity (Δu), deviation in isentropic compressibility (Δk S ), excess intermolecular free length (LfE)(L_{\mathrm{f}}^{\mathrm{E}}), excess acoustic impedance (Z E), excess pseudo-Grüneisen parameter (Γ E), and molar refraction deviation (ΔR m) were calculated using experimental values of the ultrasonic velocity, density and refractive index and were then represented with the Redlich-Kister polynomial equation. The observed excess deviation parameter values were explained on the basis of the strength of intermolecular interactions between the components of the mixtures. Estimations of the refractive index and ultrasonic velocity have also been made using various empirical relations and are discussed in terms of the average percentage deviations (APD).  相似文献   

11.
The densities, viscosities, and ultrasonic velocities of the binary mixture of toluene and mesitylene with anisaldehyde have been measured at 303.15, 308.15, 313.15, and 318.15 K for the entire range of mole fraction of anisaldehyde. From the data the excess adiabatic compressibility (β E), excess free volume (V fE), excess internal pressure (π E), excess enthalpy (H E), and excess Gibb’s free energy of activation of flow (G* E) for the binary mixture over the additive values were calculated. In light of these parameters molecular interactions involved between the component liquids have been discussed.  相似文献   

12.
Ultrasonic velocity (U), density (ρ), and viscosity (η) measurements have been carried out in three ternary mixtures of fructose with amylase in aqueous medium at 298.15 K. The experimental data have been used to calculate some derived parameters such as acoustical impedance (Z), relative association (R a ), Rao’s constant (R R), Wada’s constant (W), relaxation time (τ), relaxation amplitude (α/f 2), relaxation strength (r), and some excess thermodynamical properties like excess adiabatic compressibility (β E ), excess free length (L f E ) excess free volume (V f E ), excess internal pressure (π i E ), and excess acoustical impedance (Z E ). The above parameters have been evaluated and discussed in light of molecular interactions in the mixture.  相似文献   

13.
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   

14.

The experimental density (ρ) and the velocity (U) for ternary mixture of dimethyl acetamide diethyl ether and isobutyl methyl ketone at different frequencies (2, 4, 6 and 8 MHZ) have been measured at a constant temperature of 308 K. These data have been used to compute acoustic impedance (Z), adiabatic compressibility (K s), intermolecular free length (Lf ), molar volume (Vm ), molar sound velocity (R), molar compressibility (B), available volume (V a), Lennard-Jones potential repulsive term exponent (n), relative association (R A), interaction parameter (X) and excess values of some of the above parameters for entire range of mole fraction and are interpreted to explain molecular interaction occurring in the liquid mixture.  相似文献   

15.
The experimental density (ρ) and ultrasonic velocity (U) for ternary mixture containing dimethylacetamide (DMAC), acetone and diethyl ether at frequencies 2, 4, 6 and 8 MHz have been measured at temperature 308 K. These data are used to compute adiabatic compressibility (Ks), intermolecular free length (Lf), acoustic Impedance (Z), molar volume (Vm), molar sound velocity (R), molar compressibility (B), available volume (Va), Lennard-Jones potential repulsive term exponent (n), relative association (RA), interaction parameter (χ) and some excess thermo acoustic parameters for whole range of concentration of DMAC and are interpreted to elucidate molecular interaction occurring in the liquid mixture.  相似文献   

16.
The density (ρ), viscosity (η) and ultrasonic velocity (u) of three mixtures consisting of 2- pyrrolidone with 1,3-propanediol (PD) and water and also of PD and water have been measured as a function of mole fraction at 308.15 K. The experimentally collected data has been used to calculate the excess molar volume (VE), deviation in viscosity (Δη), deviation in ultrasonic velocity (Δu), isentropic compressibility (κs), deviation in isentropic compressibility (Δκs) and excess Gibbs free energy of activation (ΔG*E). The Redlich–Kister polynomial equation has been used to fit the derived parameters. The variation in excessive thermodynamic properties as a consequence of possible molecular interactions is discussed.  相似文献   

17.
Densities, ρ, viscosities, η, and ultrasonic sound velocities u of pure methyl isobutylketone, diethylketone, cyclopentanone, cyclohexanone, 2-methyl cyclohexanone and those of their binary mixtures with N-methyl aniline were measured at 303.15 K over the entire composition range. These experimental data have been used to calculate the excess volume (V E), deviation in ultrasonic sound velocity (?u), isentropic compressibility (κ s ), intermolecular free length (L f), excess intermolecular free length ( $ L_{\text{f}}^{\text{E}} $ L f E ), acoustic impedance (Z), excess isentropic compressibility ( $ \kappa_S^{\text{E}} $ κ S E ), deviation in viscosity (?η) and excess Gibbs energy of activation of viscous flow (G *E). The viscosity data have been correlated using three equations proposed by Grunberg and Nissan, Katti and Chaudhri, and Hind et al. The excess/deviations have been fitted by Redlich–Kister equation and the results are discussed in terms of molecular interactions present in these mixtures.  相似文献   

18.
The excess values of molar volume (V E), viscosity deviation (Δη), deviation in isentropic compressibility (ΔKS ), excess molar refraction (ΔR) and excess Gibbs energy of activation (ΔG*E ) of viscous flow have been investigated from the experimentally measured densities, viscosities, sound speeds and refractive indices for three binary mixtures of acetophenone?+?n-amyl alcohol, acetophenone?+?dichloromethane and n-amyl alcohol?+?dichloromethane and their corresponding ternary mixtures at 298.15?K over the entire composition range. The calculated quantities are further fitted to the Redlich–Kister equation to estimate the binary fitting parameters and standard deviations from the regression lines. The excess or deviation properties were found to be either negative or positive depending on the molecular interactions and the nature of liquid mixtures and have been discussed in terms of molecular interactions and structural changes.  相似文献   

19.
Densities (ρ), speeds of sound (u), and isentropic compressibilities (k S) of binary mixtures of dimethyl sulfoxide (DMSO) with water, methanol, ethanol, 1-propanol, 2-propanol, acetone and cyclohexanone have been measured over the entire composition range at 293.15 and 313.15 K. The excess molar volumes (V E), the deviations in speed of sound (u E) and the deviations in isentropic compressibility (k S E) have been determined. The V E, u E and k S E values were fitted by the Redlich-Kister polynomial equation and the A k coefficients as well as the standard deviations (d) between the calculated and experimental values have been derived. The results obtained are discussed from the viewpoint of the existence of interactions between the components of the binary mixtures.  相似文献   

20.
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   

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