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1.
Molar excess volumes, VijkE, of 1,3-dioxolane or 1,4-dioxane (i) + water (j) + formamide or dimethylformamide (k) ternary mixtures have been determined dilatometrically over the entire composition range at 308.15 K. The measured data have been analyzed in terms of (a) the graph theoretical approach, (b) the Lacombe and Sanchez theory, and (c) the Flory theory. It was observed that VijkE values predicted by graph theory compare well with their corresponding experimental values. However, VijkE values evaluated by the Lacombe and Sanchez as well as the Flory theory are of same sign and order.  相似文献   

2.
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   

3.
Molar excess volumes, VE, molar excess enthalpies, HE, and speeds of sound data, u, of pyrrolidin-2-one (i) + ethanol or propan-1-ol or propan-2-ol or butan-1-ol (j) binary mixtures have been determined over entire composition range at 308.15 K. The observed speeds of sound data have been utilized to predict excess isentropic compressibilities, of the investigated binary mixtures. The observed excess thermodynamic properties VE, HE and have been analyzed in terms of Graph theory. The analysis of VE data by the Graph theory suggests that pyrrolidin-2-one exists mainly as a mixture of cyclic and open dimer; ethanol as a mixture of dimer and trimer; butan-1-ol and propan-2-ol as mixture of monomer and dimer and propan-1-ol as a dimer in the pure state, and their mixtures contain 1:1 molecular complex. The IR studies lend additional credence to the nature and extent of interactions for the proposed molecular entities in the mixtures. Also, it has been observed that VE, HE and values predicted by the Graph theory compare well to with their corresponding experimental values.  相似文献   

4.
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   

5.
Densities, viscosities, and ultrasonic velocities of binary mixtures of trichloromethane with methanol, ethanol, propan-1-ol, and butan-1-ol have been measured over the entire range of composition, at (298.15 and 308.15) K and at atmospheric pressure. From the experimental values of density, viscosity, and ultrasonic velocity, the excess molar volumes (VE), deviations in viscosity (Δη), and deviations in isentropic compressibility (Δκs) have been calculated. The excess molar volumes, deviations in viscosity and deviations in isentropic compressibility have been fitted to the Redlich-Kister polynomial equation. The Jouyban-Acree model is used to correlate the experimental values of density, viscosity, and ultrasonic velocity.  相似文献   

6.
Densities, ρ, of the binary systems {difurylmethane + (ethanol or propan-1-ol or butan-1-ol or pentan-1-ol or hexan-1-ol)} have been measured with an Anton Paar DMA 4500 vibrating-tube densimeter over the entire composition range at 288.15 and 308.15 K and atmospheric pressure. The measured and literature densities of [difurylmethane + n-alkanol] binary systems have been used to check the validity of the relationship describing the dependence of density on composition. This relation is useful for obtaining interpolated ρ values corresponding to the experimental data. Excess molar volumes (V mE) of each mixture, limiting (V m,i E,∞) and excess partial (V m,i E) molar volumes and the limiting partial molar expansion (E p,i ) of both components of each binary system have been examined to provide insight into the temperature variations of the intermolecular interactions and molecular packing efficiencies. The results have been discussed in terms of specific intermolecular interactions and structural effects.  相似文献   

7.
Excess molar volumes V E, excess molar enthalpies H E, and speeds of sound u for 1-methyl pyrrolidin-2-one (1) + water or propan-1-ol or propan-2-ol (2) binary mixtures have been measured over the entire composition range (at 308.15 K) using a dilatometer, calorimeter and interferometer. Speeds of sound data, u, of (1 + 2) binary mixtures have been utilized to determine excess isentropic compressibilities, $ \kappa_{S}^{\text{E}} $ . The observed V E, H E and $ \kappa_{S}^{\text{E}} $ data have been analyzed in terms of (1) Graph theory (which involves the topology of the constituents of mixture), and (2) the Prigogine–Flory–Patterson theory. Analysis of V E data in terms of Graph theory suggests that 1-methyl pyrrolidin-2-one, water, propan-1-ol, and propan-2-ol exist as associated molecular entities. IR studies lend additional support to the proposed molecular entities in (1 + 2) mixtures. It has been observed that V E, H E and $ \kappa_{S}^{\text{E}} $ values predicted by Graph theory compare well with their corresponding experimental values.  相似文献   

8.
Densities (ρ)of the binary systems of {difurylmethane + (ethanol or propan-1-ol or butan-1-ol or pentan-1-ol or hexan-1-ol)} have been measured with an Anton Paar DMA 4500 vibrating-tube densimeter over the entire composition range at 298.15,K and atmospheric pressure. Excess molar volumes (V m E ) of each binary system were determined and correlated by the Redlich-Kister equation. Limiting (V i E,∞) and excess partial molar volumes (V i E ) of components of each binary system have been calculated to provide insight into the intermolecular interactions present and the packing efficiencies. The results have been discussed in terms of specific intermolecular interactions, dispersive forces and structural effects.  相似文献   

9.
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   

10.
Excess enthalpies (H E ) for mixtures of cyclohexanone with propan-1-ol. propan-2-ol, butan-1-ol, butan-2-ol and 2-methyl propan-1-ol at 298.15 K have been measured over the entire composition range. All mixed endothermically with the maximum values ofH E occurring at equimole fraction. Comments about the molecular interactions contributing to the excess enthalpies of a cyclic ketone + an alcohol are made on the basis of these results.  相似文献   

11.
In view of industrial importance of binary {ethyl alcohol + (propan-1-ol/propan-2-ol)} mixtures, the densities (ρ) and refractive indices (n D ) of these alkanols mixtures were measured for different compositions at 303.15 K. Molar volumes (V m) and excess molar volumes (V E) of these binary mixtures were calculated from experimental density data of pure solvents and solvents mixtures. The measured refractive index and density data was used to calculate specific refractions (R D ), molar refractions (R M) and apparent molar refractions (R φ, i ) of binary mixtures. From mole fraction dependence of apparent molar refractions, the limiting apparent molar refractions (R φ, i ) of propan-1-ol and propan-2-ol have been determined. The graphical values of R φ, i for propan-1-ol and propan-2-ol were found to be 9.5664 and 7.405 cm3 mol?1 respectively. Structural changes, geometrical fittings and molecular interactions in binary mixtures of these alkanols have been discussed.  相似文献   

12.
Excess molar volumes, VijkEV_{ijk}^{E}, are reported for ternary mixtures of tetrahydropyran (i)+benzene (j)+toluene or o- or p-xylenes (k) and tetrahydropyran (i)+toluene (j)+o- or p-xylenes (k) as a function of composition at 308.15 K. These VijkEV_{ijk}^{E} values have been fitted to the Redlich–Kister equation to predict ternary adjustable parameters and standard deviations. The measured VijkEV_{ijk}^{E} data have been analyzed in terms of Graph theory (which involves the topology of the constituents of mixtures). It has been observed that VijkEV_{ijk}^{E} values predicted by Graph theory compare well with their corresponding experimental values.  相似文献   

13.
Densities, ρ 123, and speeds of sound, u 123, of 1-methyl pyrrolidin-2-one (1) + benzene or methyl benzene or cyclohexane (2) + propan-2-ol (3) ternary mixtures have been measured over the entire composition range at 308.15 K and atmospheric pressure. The resulting ρ 123 and V123EV_{123}^{\mathrm{E}} data were utilized to predict excess isentropic compressibilities, (kSE)123(\kappa_{S}^{\mathrm{E}})_{123}, of the studied (1+2+3) mixtures. The observed V123EV_{123}^{\mathrm{E}} and (kSE)123(\kappa_{S}^{\mathrm{E}})_{123} data have been analyzed in terms of Graph theory (which involved the topology of a molecule). It has been observed that V123EV_{123}^{\mathrm{E}} and (kSE)123(\kappa_{S}^{\mathrm{E}})_{123} values determined by Graph theory compare well with their corresponding experimental values.  相似文献   

14.
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   

15.
Abstract

Molar excess volumes (VE ) and partial molar excess volumes ( VE ) are reported for non-electrolyte binary mixtures of n-pentanol + cumene, n-pentanol + 1,4-dioxane and cumene + 1,4-dioxane at four temperatures and over the whole concentration range. In these systems, the n-pentanol is a highly polar molecule with association in its pure state, while the others two show little polarity without association in their pure states. The results of VE are discussed in terms of the interactions between components. The Prigogine–Flory–Patterson model of solution thermodynamics has been used to predict VE . This work shows the importance of the three contributions δV int, δV p? and δVF to VE .  相似文献   

16.
Molar excess volumes, V ijk E, and speeds of sound, U ijk , of o-toluidine (i) + benzene (j) + cyclohexane or n-hexane or n-heptane (k) ternary mixtures have been measured as a function of composition at 308.15 K. The observed speed of sound data have been utilized to determine the excess isentropic compressibilities, (K S E) ijk , of the ternary (i+j+k) mixtures. The Moelywn-Huggins concept (Huggins in Polymer 12: 389–399, 1971) of connectivity between the surfaces of the binary mixture constituents has been extended to ternary mixtures (using the concept of a connectivity parameter of third degree of molecules, 3 ξ, which in turn depends on its topology) to obtain an expression that describes well the measured V ijk E and (K S E) ijk data. The observed data have also been analyzed in terms of Flory’s theory.  相似文献   

17.
Excess molar volumes, V123EV_{123}^{\mathrm{E}}, of 1,3-dioxolane or 1,4-dioxane (1) + aniline (2) + benzene or toluene (3) ternary mixtures have been determined over the entire mole fraction range at 308.15 K. V123EV_{123}^{\mathrm{E}} data have been fitted to the Redlich-Kister equation to evaluate ternary adjustable parameters and standard deviations. The observed V123EV_{123}^{\mathrm{E}} data have been analyzed in terms of (i) Graph theory, (ii) Prigogine-Flory-Patterson theory, and (iii) Sanchez and Lacombe theory. It has been observed that V123EV_{123}^{\mathrm{E}} values predicted by Graph theory compare well with the corresponding experimental values.  相似文献   

18.
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   

19.
Kinetics of dehydrogenation of propan-2-ol on the most active catalyst found in the mixed calcium-cobalt orthophosphate system, Ca3-xCox(PO4)2, with x=0.32, has been studied. The activation energy of the reaction was also determined.  相似文献   

20.
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   

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