Densities,Viscosities, and Refractive Indices of Mixtures of Hexane with Cyclohexane,Decane, Hexadecane,and Squalane at 298.15 K

Densities, ρ, viscosities, η, and refractive indices, n_D, have been measured as a function of composition for binary mixtures of cyclohexane, decane, hexadecane, and squalane with hexane at 298.15 K and atmospheric pressure. From these measurements the excess molar volumes, V_m^E, viscosity deviations, δη, and the change in refractive indices on mixing, Δn_D, were calculated. These results were fitted to Redlick–Kister polynomial equations to estimate the binary coefficients and standard errors. The effects of size and shape of the components on excess properties have been discussed.     

Densities,Viscosities, Sound Speeds,Refractive Indices,and Excess Properties of Binary Mixtures of Isoamyl Alcohol with Some Alkoxyethanols

Densities and viscosities were measured for binary mixtures of isoamyl alcohol with 2-methoxyethanol, 2-ethoxyethanol, and 2-butoxyethanol over the entire range of composition at 303.15 K, 313.15 K, and 323.15K and ultrasonic speeds and refractive indices at 303.15 K under atmospheric pressure. From the experimental values of density, viscosity, ultrasonic speed, and refractive index, the values of excess molar volume (V ^E), viscosity deviations (Δη), deviations in isentropic compressibility (ΔK _S ), and excess molar refraction (ΔR) have been calculated. The excess or deviation properties were found to be either negative or positive, depending on the molecular interactions and the nature of liquid mixtures.     

Densities,Excess Molar Volumes,Viscosities, and Refractive Indices of Binary Mixtures of <Emphasis Type="Italic">n</Emphasis>-Butyl Acetate with 1-Chloroalkanes (C<Subscript>4</Subscript>–C<Subscript>8</Subscript>) at 298.15 K

Densities, viscosities, and refractive indices of binary mixtures of n-butyl acetate (1)  +1-chlorobutane (2), +1-chloropentane (2), +1-chlorohexane (2), +1-chloroheptane (2), and +1-chlorooctane (2) were measured at 298.15 K for the liquid region and at ambient pressure for the whole composition range. The excess molar volumes V ^E were calculated from experimental densities. McAllister’s three-body interaction, and Hind and Grunberg–Nissan models are used for correlating the viscosity of binary mixtures. The experimental data of binaries are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures.     

Densities and Volumetric Properties of Binary Mixtures of Butyl Acrylate with Benzene, Toluene, o-Xylene, m-Xylene, p-Xylene, and Mesitylene at Temperatures from 288.15?K to 318.15?K

The densities, ρ, of binary mixtures of butyl acrylate (BA) with benzene, toluene, o-xylene, m-xylene, p-xylene, and mesitylene, including those of pure liquids, over the entire composition range were measured at the temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K and atmospheric pressure. From the experimental data, the excess molar volumes, V_m^E{V_{\rm m}^{\rm E}} were calculated. The V_m^E{V_{\rm m}^{\rm E}} values were negative over the whole composition range for all the mixtures and at each temperature studied, except for BA + mesitylene which exhibit positive V_m^E{V_{\rm m}^{\rm E}} values, indicating the presence of specific interactions between BA and aromatic hydrocarbon molecules. The deviations in V_m^E{V_{\rm m}^{\rm E}} values follow the order: benzene<toluene<p-xylene<m-xylene<o-xylene<mesitylene. It is observed that V_m^E{V_{\rm m}^{\rm E}} values depend upon the number and position of the methyl groups in these aromatic hydrocarbons.     

Densities and Viscosities of Binary Mixtures of Methanol with Dimethyl Methylphosphonate and Dimethyl Phosphite from (293.15 to 333.15) K

Densities and viscosities of methanol + dimethyl methylphosphonate and methanol + dimethyl phosphite binary mixtures were measured over a temperature range of (293.15 to 333.15) K at atmospheric pressure. The experimental data were compared with literature values. From these data, excess molar volumes (V ^E) were calculated. The density data were fitted to a second-order polynomial, and the viscosity data were fitted to the Andrade equation.     

Excess volumes and excess viscosities of binary mixtures of 1-bromo-2-methylpropane + an isomer of butanol at 298.15 and 313.15 K

Excess volumesV ^E, excess viscosities ^E, and excess free energies of activation of flow G^*E at 298.15 and 313.15 K are reported for binary mixtures of 1-bronw-2-methypropane and each of the alcoholic isomers of I-butanol. The results were obtained from density and viscosity measurements and show positive values forV ⁴ and negative for both ^E andG ^*E for all mixtures over the entire composition range.     

Temperature Dependence of Densities and Excess Molar Volumes of the Ternary Mixture (1-Butanol + Chloroform + Benzene) and its Binary Constituents (1-Butanol + Chloroform and 1-Butanol + Benzene)

Densities ρ of the 1-butanol + chloroform + benzene ternary mixture and the 1-butanol + chloroform and 1-butanol + benzene binaries have been measured at six temperatures (288.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K and atmospheric pressure, using an oscillating U-tube densimeter. From these densities, excess molar volumes (V ^E) were calculated and fitted to the Redlich–Kister equation for all binary mixtures and to the Nagata and Tamura equation for the ternary system. The Radojković et al. equation has been used to predict excess molar volumes of the ternary mixtures. Also, V ^E data of the binary systems were correlated by the van der Waals (vdW1) and Twu–Coon–Bluck–Tilton (TCBT) mixing rules coupled with the Peng–Robinson–Stryjek–Vera (PRSV) equation of state. The prediction and correlation of V ^E data for the ternary system were performed by the same models.     

Densities,Viscosities, Speeds of Sound,and Refractive Indices of Binary Mixtures of 1-Decanol with Isomeric Chlorotoluenes

Densities, ρ, viscosities, η, speeds of sound, u, and refractive indices, n _D, of binary liquid mixtures of 1-decanol with o-chlorotoluene, m-chlorotoluene, and p-chlorotoluene have been measured over the entire range of composition at 298.15 K, 303.15 K, and 308.15 K and at atmospheric pressure. From the experimental data of density, speed of sound, viscosity and refractive index, the values of the excess molar volume, V ^E, deviations in isentropic compressibility, Δκ _S , and deviations in molar refraction, ΔR, have been calculated. The calculated excess and deviation functions have been analyzed in terms of molecular interactions and structural effects.     

Densities,Viscosities, Speeds of Sound,and Refractive Indices of Binary Mixtures of 2-Octanol with Chlorobenzenes

Densities, ρ, viscosities, η, speeds of sound, u, and refractive indices, n _D, of binary liquid mixtures of 2-octanol with 1,2-dichlorobenzene, 1,3-dichlorobenzene, and 1,2,4-trichlorobenzene have been measured over the entire range of composition at 298.15 K, 303.15 K, and 308.15 K and at atmospheric pressure. From the experimental data of the density, speed of sound, viscosity, and refractive index, the values of the excess molar volume, V ^E, deviations in isentropic compressibility, Δκ _S , and deviations in molar refraction, ΔR have been calculated. The calculated excess and deviation functions have been analyzed in terms of molecular interactions and structural effects.     

Ultrasonic Velocity Studies of Drug Parvon-spas in Mixed Alcohol–Water Solvent Systems at 25°C

Ultrasonic velocities and densities of the drug Parvon-spas in binary mixtures of water with methanol (MeOH), ethanol (EtOH), and propan-1-ol (1-PrOH) have been measured over the complete solvent composition range at 10 mol% intervals at 25°C. Various acoustic parameters such as the acoustic impedance (Z), adiabatic compressibility (β), intermolecular free length (L_f), relative association (R.A.), molar volume (V_m), and molar sound velocity (R_m) have been calculated. In addition, excess functions, i.e., excess adiabatic compressibility (β^E), excess intermolecular free length (L_f^E), excess molar volume (V^E), excess ultrasonic velocity (U^E), and excess acoustic impedance (Z^E) for these three solvent mixtures in the absence and presence of the drug have been calculated. A different behavior of these parameters in these alcohol systems has been discussed in terms of the length of the alcohol molecule, the molecular volume, as well as inter/intramolecular interactions of these molecules.     

Excess volumes and excess viscosities of binary mixtures of some cyclic ethers + bromocyclohexane at 298.15 and 313.15 K

Excess Volumes,V ^E, and excess viscosities, ^E, at 293.15 and 313.15 K are reported for binary mixtures of some cyclic ethers (tetrahydrofuran, tetrahydropyran, 2-methyltetrahydrofuran and 2,5-dimethyltetrahydrofuran) + bromocyclohexane. These properties were obtained from density and viscosity measurements. ^E and ^E show negatives values for all the mixtures.     

Densities, Sound Speeds, Excess Volumes, and Excess Isentropic Compressibilities of Methyl Acrylate + 1-Propanol (or 1-Butanol) + Hydrocarbons(n-Hexane, n-Heptane, Cyclohexane, Benzene, and Toluene) at 308.15 K

Densities and sound speeds of ten ternary mixtures of methyl acrylate (1)+1-propanol (2) or 1-butanol (2)+n-hexane (3), +n-heptane (3), +cyclohexane (3), +benzene (3), and +toluene (3) have been measured at 308.15 K. The excess volumes, V ^E , and excess isentropic compressibilities, ^E _s , have been estimated. These two experimentally derived excess functions were also compared with those predicted by empirical equations of Redlich–Kister, Kohler, and Tsao–Smith. A qualitative analysis of V ^E and ^E _s data of ternary mixtures reveals that in MA (1)+1-alcohols (2)+n-hexane (3), +n-heptane (3), and +cyclohexane (3), structure disruptions are more predominant while in MA (1)+1-alcohols (2)+benzene (3) or +toluene (3) mixtures, the weak but specific structure making interactions dominate. A perusal of deviations between the experimental and calculated V ^E and ^E _s results shows that the predictive expressions give only a rough estimate of the functions for the ten studied mixtures.     

Volumetric measurements under pressure for 2,2,4-trimethylpentane at temperatures up to 353.15 K and for benzene and three of their mixtures at temperatures up to 348.15 K

(p, V, T) data have been obtained in the form of volume ratios relative to 0.1 MPa for benzene (298.15 to 348.15 K), 2,2,4-trimethylpentane (TMP) (313.15 to 353.15 K), and their mixtures near 0.25, 0.5, and 0.75 mole fraction of benzene (313.15 to 348.15 K) for pressures up to near the freezing pressures for benzene and the mixtures, and up to 400 MPa for TMP. Isothermal compressibilitiesκ _T, isobaric expansivitie α, changes in heat capacity at constant pressureΔC _p, and excess molar volumesV ^E have been determined from the data. Literature data at atmospheric pressure have been used to convert theΔC _p toC _p at several temperatures. The isobars for α over the temperature range 278.15 to 353.15 K for TMP intersect near 47 MPa and reverse their order in temperature when plotted against pressure; normalization of the α's by dividing the values at each temperature by the α at 0.1 MPa prevents both the intersection and the reversal of the order. TheV ^E are positive and have an unusual dependence on pressure: they increase with temperature and pressure so that the order of the curves for 0.1, 50, and 100 MPa changes in going from 313.15 to 348.15 K.     

Density,Viscosity, and Surface and Interfacial Tensions of Mixtures of Water + <Emphasis Type="Italic">n</Emphasis>-Butyl Acetate + 1-Propanol at 303.15 K and Atmospheric Pressure

Experimental densities, viscosities, and surface and interfacial tensions have been measured at 303.15 K for liquid mixtures of water + n-butyl acetate + 1-propanol. The excess molar volume, V ^E, viscosity, η, and surface tension, γ, were calculated and rational functions due to Myers and Scott, and Pando et al. were used to describe the composition dependence of these properties. The viscosity, η, of the mixtures was correlated using a theoretically based method developed from the Eyring theory using the above-mentioned rational functions to express the excess Gibbs energy of activation for viscous flow, G ^≠E. The UNIMOD model based on the Eyring theory was used to correlate the viscosity of the binaries and to predict the same property for ternary mixtures. To describe the above-mentioned properties of the ternary system, binary pair additivity and some empirical models were considered. The methods of Fu et al. and Li et al. were used to correlate the binary surface tension and also to predict the ternary behavior. The interfacial tension was correlated by the Li and Fu method.     

Thermal equilibration of fluids near the liquid-vapor critical point:3He and3He-4He mixtures

We study the temperature-equilibration process of fluids at constant volume in a thermal conductivity cell, where an initial temperature gradient relaxes to zero. The calculation is performed in the linear approximation for a pure fluid and a binary mixture. Near the critical point of the pure fluid, the adiabatic heating process, which takes place at constant volumeV, causes equilibration to proceed four times faster whenC _P /C _V 1 than for the process at constant pressureP. For the mixtures, the relaxation rate enhancement at constantV compared with constantP is restricted to a temperature region where the coupling between temperature and mass diffusion is small. The predictions are compared with experimental results for³He and for two³He-⁴He mixtures along their critical isochores. Finally, we discuss the thermal relaxation in the two-phase (liquid-gas) and one-phase (gas) regimes at the critical density, as measured with a conductivity and a calorimetry cell. The contrasting behavior for³He and a³He-⁴He mixture in these two regimes and under these different constraints is pointed out and discussed.     

Thermodynamic Properties of Ternary Liquid Mixtures of 2-Pyrrolidinone with Aromatic Hydrocarbons

Molar excess volumes, V^E_ijk{V^{\rm E}_{ijk}}, and speeds of sound, u _ijk , of 2-pyrrolidinone (2-Py) (i) + toluene (j) + o-xylene or p-xylene (k) ternary mixtures have been determined by using a dilatometer and interferometer as a function of composition at 308.15 K. The speeds of sound of ternary mixtures have been utilized to predict their excess isentropic compressibilities. The Redlich-Kister equation has been fitted to the molar excess volumes, V^E_ijk{V^{\rm E}_{ijk}}, and excess isentropic compressibilities, ( k_S^E)_ijk{\left( {\kappa _S^{\rm E}}\right)_{ijk}}, to predict ternary adjustable parameters and standard deviations. The observed data have been analyzed in terms of the Flory theory and the Sanchez and Lacombe theory.     

Temperature Dependence of the Volumetric Properties of Binary Mixtures Containing Polyethers and 1-Propanol

Excess molar volumes (V ^E _m ) were measured at 288.15, 298.15, and 308.15 K and atmospheric pressure as a function of composition with a continuous dilution dilatometer for the binary mixtures of 1-propanol [CH₃CH₂CH₂OH] with glymes [CH₃O(CH₂CH₂O) _m CH₃, m=1,2,3, and 4]. With these results and other thermodynamic data from the literature, the following mixing quantities have been reported over the complete range of concentration or at equimolar concentration: , volume expansivity; ^E , excess volume expansivity; (V ^E _m /T) _P , and (H ^E /P) _T at 298.15 K. The Prigogine–Flory–Patterson theory (PFP) of liquid mixtures has been applied to estimate interaction, free-volume, and internal-pressure contributions to V ^E _m and to estimate the different mixing quantities for the mixtures. The calculated values using the PFP theory were then compared at 298.15 K with the experimentally obtained results. The PFP theory predicts excess volume V ^E _m values rather well, while the calculated value of (V ^E _m /T) _P and (H ^E /P) _T by using the Flory theory show general variation with the chain length of the glyme. The (V ^E _m /T) _P and (H ^E /P) _T show deviations between theoretical and experimental values that are slightly larger in systems with lower glyme.     

Transport properties of nonelectrolyte liquid mixtures. VIII. Viscosity coefficients for toluene and for three mixtures of toluene + hexane from 25 to 100°C at pressures up to 500 MPa

Viscosity coefficients measured using a two-coil self-centering falling-body viscometer are reported for toluene and three binary mixtures of toluene + n-hexane at 25, 50, 75, and 100°C at pressures up to 500 MPa. The data for a given composition at different temperatures and pressures are correlated very satisfactorily by a plot of reduced viscosity ^* versus log V, where V=V·V ₀(T_R)/V₀(T) and V ₀ represents a characteristic volume. The binary mixture data are well represented by the Grunberg and Nissan equation with a mixing parameter which is pressure dependent but composition and temperature independent.     

Measurements of the Properties of Binary Mixtures of Dimethylsulphoxide (DMSO) with 1-Alkanols (C4, C6, C7) at 303.15 K

This paper presents experimental data for densities, ρ, ultrasonic velocities, u, and refractive indices, n, of pure dimethylsulphoxide (DMSO), 1-butanol, 1-hexanol, 1-heptanol, and their binary mixtures, with DMSO as a common component, over the whole composition range at 303.15 K. The molar refraction, R_m, molecular association, M_A, excess molar volume, V^E, and deviation in isentropic compressibility, ΔK_s, were calculated from the experimental data. The apparent molar volume, V_ϕ,2, and apparent molar isentropic compressibility, K_ϕ,2, of alkanols in DMSO were also calculated. The values of V_ϕ,2 and K_ϕ,2 were used to estimate the partial molar volume, , and partial molar isentropic compressibility, , of alkanols in DMSO at infinite dilution. The changes in these parameters with composition and the size of the alkyl chain length in the alkanol molecule are discussed with reference to the nature of interactions between component molecules. Excess molar volumes have also been estimated from measurements of refractive indices     

Densities,Viscosities, and Refractive Indices of Binary Mixtures of Benzene with Isomeric Butanols at 30°C

The densities, , viscosities, , and refractive indices, n, of binary mixtures of benzene with 1-butanol, 2-methyl-1-propanol, 2-butanol, and 2-methyl-2-propanol, including those of the pure liquids, were measured over the complete composition range at 30°C. The dependence of , , and n on composition was checked by using an empirical relation. The experimental data were used to calculate excess molar volumes, V^E, deviations in viscosity, , excess free energies of activation of viscous flow, G^*E, deviations in refractive index, n, apparent molar volumes, V_,1 and V_{, 2}, and partial molar volumes, , of benzene in alcohols and alcohols in benzene, respectively, at infinite dilution. The variations of these parameters with composition and the effect of branching in alcohols were discussed from the point of view of intermolecular interactions in these mixtures.