共查询到20条相似文献,搜索用时 31 毫秒
1.
The excess molar volume (V E), viscosity deviations (Δη) and Gibbs excess energy of activation for viscous flow (G∗E) have been investigated from density (ρ) and viscosity (η) measurements of eight binary mixtures of 1,3-dioxolane with methanol,
ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, and i-amyl alcohol over the entire range of mole fractions at 303.15 K. The viscosity data have been correlated with the Grunberg
and Nissan equation. Furthermore, excess isentropic compressibilities (KSE) have been calculated from ultrasonic speed measurements of these binary mixtures at 303.15 K. The deviations have been fitted
by a Redlich–Kister equation and the results are discussed in terms of molecular interactions and structural effects. The
excess properties are found to be either negative or positive depending on the molecular interactions and the nature of the
liquid mixtures. The systems studied exhibit very strong cross association through hydrogen bonding. 相似文献
2.
K. P. Singh Harshit Agarwal Vivek Kumar Shukla Isht Vibhu Manisha Gupta J. P. Shuka 《Journal of solution chemistry》2010,39(11):1749-1762
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
3.
The formation of hydrogen bonds between different types of molecules in binary alcohol mixtures (methyl alcohol, ethyl alcohol,
ethylene glycol, propylene glycol and glycerol) have been investigated (each system at 21 mixture concentrations) by an analysis
of their dielectric parameters. The static dielectric constant ε
o, limiting high-frequency dielectric constant ε
∞, excess dielectric parameters ε
oE and ε
∞E, effective Kirkwood correlation factor g
eff, and corrective Kirkwood correlation factor g
f of the binary alcohol mixtures were determined at 25 °C in order to explore hydrogen-bond interactions and the strength of
molecular connectivities between unlike alcohol molecules and their dipole alignment. These results confirm that the different
alcohol mixtures form hydrogen-bonded structures, which are strongly influenced by the numbers of hydroxyl groups and carbon
atoms of the alcohol molecules and vary with the concentrations of the mixtures. 相似文献
4.
Ufuk Sancar Vural Fatih Durmaz Ozcan Kocyigit Hasan Kocyigit V. Muradoglu Beril Akin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2008,82(13):2260-2268
Excess molar volumes (V
E), viscosities, refractive index, and Gibbs energies were evaluated for binary biodiesel + benzene and toluene mixtures at
298.15 and 303.15 K. The excess molar volumes V
E were determined from density, while the excess Gibbs free energy of activation G*E was calculated from viscosity deviation Δη. The excess molar volume (V
E), viscosity deviation (Δη), and excess Gibbs energy of activation (G*E) were fitted to the Redlich-Kister polynomial equation to derive binary coefficients and estimate the standard deviations
between the experimental data and calculation results. All mixtures showed positive V
E values obviously caused by increased physical interactions between biodiesel and the organic solvents. 相似文献
5.
K. Saravanakumar T. G. Lavanya R. Baskaran T. R. Kubendran 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(4):568-576
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
6.
Manapragada V. Rathnam Sharad Mankumare Kirti Jain M. S. S. Kumar 《Journal of solution chemistry》2012,41(3):475-490
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
7.
Excess molar volumes (V
m
E
) and viscosities (η) of the binary mixtures of 1,2-diethoxyethane with di-, tri- and tetrachloromethane have been measured
at 298-15 K and atmospheric pressure over the entire mole fraction range. The deviations in viscosities (δlnη) and excess
energies of activation (δG*E) for viscous flow have been calculated from the experimental data. The Prigogine-Flory-Patterson (PFP) model has been used
to calculateV
m
E
, and the results have been compared with experimental data. The Bloomfield and Dewan model has been used to calculate viscosity
coefficients and these have also been compared with experimental data for the three mixtures. The results have been discussed
in terms of dipole-dipole interactions between 1,2-diethoxyethane and chloroalkanes and their magnitudes decreasing with the
dipole character of the molecules. A short comparative study with results for mixtures with polyethers and chloroalkanes is
also described. 相似文献
8.
The heterogeneous associating behavior of the aqueous binary mixtures of ethyl alcohol, ethylene glycol, glycerol and mono alkyl ethers of ethylene glycol, and aqueous ternary mixtures of equi-molar binary systems (i.e., mono alkyl ethers of ethylene glycol with ethyl alcohol, ethylene glycol and glycerol) have been investigated over the entire concentration range using accurately measured dielectric constants at 25 ∘C. The concentration dependent values of the excess dielectric parameter εE and effective Kirkwood correlation factor g
eff were determined using the measured values of the static dielectric constant, εo, at 1 MHz and the high frequency limiting dielectric constant ε∞ = n
D
2. The observed εE values in aqueous binary and ternary mixtures are negative over the entire concentration range, which implies the formation of heterogeneous complexes between these molecules that reduces the effective number of dipoles. The stoichiometric ratio corresponding to the maximum interaction in alcohol + water mixtures increases with an increase in the number of hydroxyl groups of the alcohol molecules, but for mono alkyl ethers of ethylene glycol + water mixtures it decreases with the increase in the molecular size of the mono alkyl ethers. In aqueous ternary mixtures the stoichiometric ratio for the maximum extent of heterogeneous interaction is governed by the molecular size of the mono alkyl ethers. It was also found that the strength of the heterogeneous H–bond connectivities in the water + alcohol systems decrease with an increase in the number of hydroxyl groups of the alcohol molecules. However in the case of water + mono alkyl ether binary mixtures and in ternary mixtures, the strength of H–bond connectivities increases with the increase in the molecular size of the mono alkyl ether. An analysis of the g
eff values confirms that the heterogeneous interaction involves the orientation of molecular dipoles in the studied systems. 相似文献
9.
《Physics and Chemistry of Liquids》2012,50(4):428-436
Density and refractive index have been measured for the binary mixture of dimethyl sulphoxide (DMSO) with propanoic acid and n-butyric acid at three temperatures, 293, 303 and 313 K, over the entire composition range. Excess parameters such as excess molar volume (V E) and molar refraction deviation (ΔR m) have been calculated from the measured density and refractive index to study the molecular association between the component molecules. The V E and ΔR m values of these mixtures were fitted to the Redlich–Kister polynomial equation. Both excess parameters were plotted against the mole fraction of DMSO over the whole composition range. The values of V E and ΔR m have been found to be negative for both mixtures over the entire composition range, which suggests the presence of strong intermolecular interaction. The experimental refractive data of these mixtures were also used to test the validity of the empirical relations for the refractive index. 相似文献
10.
The refractive index, n
D
, and density, ρ, of binary mixtures of monoalcohols + water, have been measured at a temperature of 298.15,K and atmospheric pressure. The variation of the refractive indices of these solutions has also been determined with temperature in the range T = (278.15 to 338.15) K and atmospheric pressure. A comparative study has been made of the refractive indices obtained experimentally and those calculated by means of the Lorentz-Lorenz [Theory of Electrons, Dover Phoenix (1952)] and Gladstone-Dale relations [Trans. R. Soc. London 148:887–902 (1858)]; in all cases, the Gladstone–Dale equation was seen to afford values similar to those obtained experimentally. Calculations have been made of the excess molar volumes, V
E, and the molar refraction deviations, ΔR, of these mixtures and the differences between the experimental values for refractive index and those obtained by means of the Gladstone–Dale equation. Values of V
E were compared with others in the literature. In all cases the V
E values were negative, and in all cases, except in the methanol + water, ΔR showed a maximum for x = 0.8. 相似文献
11.
Abstract
Experimental densities ρ, viscosities η, and refractive indices n D of the ternary mixtures consisting of 2-methyltetrahydrofuran + chlorobenzene + cyclopentanone and constituted binary mixtures were measured at T = 298.15 K for the liquid region and at ambient pressure for the whole composition range. Excess molar volumes V\textm\textEV_{\text{m}}^{\text{E}}, deviations in the viscosity Δη, and deviations in the refractive index Δn D from the mole fraction average for the mixtures were derived from the experimental data. The excess partial molar volumes V\textm,i\textEV_{{\text{m}},i}^{\text{E}} were also calculated. The binary and ternary data of V\textm\textEV_{\text{m}}^{\text{E}}, Δη, and Δn D were correlated as a function of the mole fraction by using the Redlich–Kister and the Cibulka equations, respectively. McAllister’s three-body interaction model is used for correlating the kinematic viscosity of binary mixtures with the mole fraction. 相似文献12.
《Physics and Chemistry of Liquids》2012,50(4):367-374
Refractive indexes (n D ) of numerous binary mixtures of 2-methoxyethanol + diethylamine, 2-methoxyethanol + triethylamine, and 2-methoxyethanol + propylamine, between 288.15 and 308.15?K, are reported. Furthermore, the excess molar refraction (R E ) and deviation from ideality refractive index (Δn D ) have been examined, in order to identify the presence of intermolecular complexes in these binary liquid mixtures. 相似文献
13.
S. D. Deosarkar A. L. Puyad 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2014,88(6):946-950
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
14.
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
15.
M. N. Roy R. Chanda B. K. Sarkar 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(10):1737-1746
The densities and viscosities of several sulfates, viz., ammonium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate,
zinc sulfate and cadmium sulfate in aqueous binary mixtures of formamide (FA) have been determined at 298.15, 308.15, and
318.15 K and at atmospheric pressure. The ultrasonic speeds of the electrolytic solutions have also been measured at 298.15
K. Apparent molar volumes (ϕ
V
), viscosity B-coefficients and adiabatic compressibilities (K
S) of these electrolytic solutions were calculated from the experimental densitiy, viscosity and acoustic data. The density
and viscosity data were evaluated by using Masson’s and Jones-Dole equation respectively; the derived parameters have been
analyzed in terms of ion-ion and ion-solvent interactions. The structure making/breaking capacities of the electrolytes have
been inferred from the sign of (∂2ϕ
V
0/∂T
2)
P
. The results showed that all the electrolytes act as structure-makers in these media. Also the compressibility data indicated
electrostriction of the solvent molecules around the cations. The activation parameters of viscous flow were also determined
and discussed by the application of transition state theory. 相似文献
16.
Abbas Ali Rostami Mohammad Javad Chaichi Mostafa Sharifi 《Monatshefte für Chemie / Chemical Monthly》2007,138(10):967-971
Summary. Density (ρ) and viscosity (η) values of the binary mixtures of DMP + 1-pentanol, 1-butanol, and 1-propanol over the entire range of mole fraction at 298.15 and 303.15 K were measured in atmospheric
pressure. The excess molar volume (V
E), viscosity deviations (Δη), and excess Gibbs energy of activation for viscous flow (G*E) were calculated from the experimental measurements. These results were fitted to Redlich–Kister polynomial equation to estimate the binary interaction parameters.
The viscosity data were correlated with equations of McAllister. The calculated functions have been used to explain the intermolecular interaction between the mixing components. 相似文献
17.
Densities (ρ), viscosities (η) and speeds of sound (u) of the ternary mixture (1-heptanol + tetrachloroethylene + methylcyclohexane) and the corresponding binary mixtures (1-heptanol + tetrachloroethylene),
(1-heptanol + methylcyclohexane) and (tetrachloroethylene + methylcyclohexane) at 298.15 K were measured over the whole composition
range. The data obtained are used to calculate the excess molar volumes (V
E), excess isobaric thermal expansivities (α
E), viscosity deviations (Δη), excess Gibbs energies of activation of viscous flow (ΔG
*E) and excess isentropic compressibilities (κ
S
E) of the binary and ternary mixtures. The data from the binary systems were fitted by the Redlich–Kister equation whereas
the best correlation method for the ternary system was found using the Nagata equation. Viscosities, speeds of sound and isentropic
compressibilities of the binary and ternary mixtures have been correlated by means of several empirical and semi-empirical
equations. The best correlation method for viscosities of binary systems is found using the Iulan et al. equation and for
the ternary system using the Heric and McAllister equations. The best correlation method for the speeds of sound and isentropic
compressibilities of the binary system (1-heptanol + methylcyclohexane) is found using IMR (Van Deal ideal mixing relation)
and for the binary system (tetrachloroethylene + methylcyclohexane) it is found using the NR (Nomoto relation) and for the
binary system (1-heptanol + tetrachloroethylene) and the ternary system (1-heptanol + trichloroethylene + methylcyclohexane)
it is obtained from the FLT (Jacobson free length theory). 相似文献
18.
The excess molar volumes, V
mE, viscosity deviations, Δη, and excess Gibbs energies of activation, ΔG
*E, of viscous flow have been investigated from density and viscosity measurements for two ternary mixtures, 1-butanol + triethylamine
+ cyclohexane and 1-pentanol + triethylamine + cyclohexane, and corresponding binaries at 303.15 K and atmospheric pressure
over the entire range of composition. The empirical equations due to Redlich-Kister, Kohler, Rastogi et al., Jacob-Fitzner,
Tsao-Smith, Lark et al., Heric-Brewer, and Singh et al. have been employed to correlate V
mE, Δη and ΔG
*E of the ternary mixtures with their corresponding binary parameters. The results are discussed in terms of the molecular interactions
between the components of the mixture. Further, the Extended Real Associated Solution, ERAS, model has been applied to V
mE for the present binary and ternary mixtures, and the results are compared with experimental data. 相似文献
19.
The viscosities, η, and refractive indices, n, of pure dimethylsulphoxide (DMSO), benzene, toluene, o‐xylene, m‐xylene, p‐xylene and mesitylene, and those of their 54 binary mixtures, with DMSO as common component, covering the whole composition range have been measured at 298.15, 303.15, 308.15, 313.15, and 318.15 K. From the experimental data, the deviations in viscosity, Δη and deviations in molar refraction, ΔRm have been calculated. The variation of these parameters with composition and temperature of the mixtures have been discussed in terms of molecular interaction in these mixtures. The effect of the number and position of the methyl groups in these aromatic hydrocarbons on molecular interactions in these mixtures has also been discussed. The free energies, ΔG*, enthalpies, ΔH* and entropies, ΔS* of activation of viscous flow have also been obtained by using Eyring viscosity equation. The ΔH* values were found independent of temperature. The dependence of these thermodynamic parameters on composition of the mixtures has been discussed. Further, the viscosities and refractive indices of these binary mixtures were calculated theoretically from pure component data by using various empirical and semi‐empirical relations and the results were compared with the experimental findings. 相似文献
20.
Malyanah M. Taib Abobakr K. Ziyada Cecilia Devi Wilfred Thanapalan Murugesan 《Journal of solution chemistry》2012,41(1):100-111
Densities and refractive indices have been measured for binary mixtures of 1-propyronitrile-3-hexylimidazolium bromide + ethanol
in the temperature range 293.15–323.15 K. From the experimental data the excess molar volume V
E, refractive index deviation Δn
D, and the coefficient of thermal expansion α were calculated and fitted to fifth- and third-order Redlich–Kister type equations, respectively. Using the measured densities,
the apparent molar volumes (V
ϕ
), limiting apparent molar volumes (Vf0V_{\phi}^{0}) and limiting apparent molar expansivities (Ef 0E_{\phi} ^{0}) were also determined and the details are discussed. 相似文献