Limiting partial molar volumes at 298.15 K of some open chain and cyclic organic compounds in 1—octanol

Partial molar volumes at 298.15 K in 1—octanol have been determined for some hydrocarbons, ethers, ketones, and water from density measurements carried out with a vibrating-tube density meter.In the transfer process from the pure liquid state to the infinitely dilute solution in 1—octanol, a slight shrinkage is generally observed for solutes showing density values lower than that of the solvent. On the contrary, for solutes with higher density values, a weak expansion is produced.Comparisons are made among the partial molar volumes of organic solutes in 1—octanol, in water, and in other organic solvents. The case of water as a solute in 1—octanol and in many other organic liquids is carefully considered. In non-polar solvents the value of the limiting partial molar volume of water is always larger in respect to the value of the molar volume of pure water, but in polar solvents the contrary occurs. An explanation of this phenomenon is provided and a rationale is given to the value of the limiting partial molar volume of water in 1—octanol and to the trend exhibited by the partial molar volume of water in the 1—octanol/water mixture as water concentration is increased.     

Viscous synergy and antagonism,excess molar volume,isoentropic compressibility and excess molar refraction of ternary mixtures containing tetrahydrofuran,methanol and six membered cyclic compounds at 298.15 K

The densities (ρ), viscosities (η), sound speeds (u) and refractive indices (n _D) of seven ternary mixtures of cyclic ether (tetrahydrofuran), methanoland cyclic compounds; benzene, toluene, chlorobenzene, nitrobenzene, anisole, cyclohexane and cyclohexanone are determined over the entire range of composition at 298.15?K. From the experimental observations, viscosity deviation (Δη), the viscous synergy and antagonism, synergic and antagonic index are derived by the equations developed by Kalentunc-Gencer and Peleg [G. Kalentunc-Gencer and M. Peleg, J. Texture Stud. 17, 61 (1986)] and Howell [N.K. Howell, Presented at the Proceedings of the Seventh International Conference, Wales, 1993], respectively. Excess molar volume (V ^E), excess isoentropic compressibility (ΔK _S) and excess molar refraction (ΔR) have been calculated from the experimentally measured density, sound speed and refractive index values. The excess Gibb's free energy of activation (ΔG ^E) has also been calculated. The results are discussed and interpreted in terms of molecular package and specific interaction predominated by hydrogen bonding.     

Apparent molar volumes and apparent molar heat capacities of aqueous d-lactose · H2O at temperatures from (278.15 to 393.15) K and at the pressure 0.35 MPa

Apparent molar volumes V_φ and apparent molar heat capacities C_p,φ were determined for aqueous solutions of d-lactose · H₂O at molalities (0.01 to 0.34) mol · kg⁻¹ at temperatures (278.15 to 393.15) K, and at the pressure 0.35 MPa. Our V_φ values were calculated from densities obtained using a vibrating tube densimeter, and our C_p,φ values were obtained using a twin fixed-cell, power-compensation, differential-output, temperature-scanning calorimeter. Our results for d-lactose(aq) and for d-lactcose · H₂O were fitted to functions of m and T and compared with the literature results for aqueous d-glucose and d-galactose solutions. Infinite dilution partial molar volumes V₂^∘ and heat capacities C_p,2^∘ are given over the range of temperatures.     

Apparent molar and partial molar volumes of aqueous ceric ammonium nitrate solutions at 20, 25, 30, and 35°C

Present paper reports the measured densities (ρ) and refractive indices (n _D) of aqueous solutions of ceric ammonium nitrate (CAN) at 20, 25, 30, and 35°C in different concentrations of solution. Apparent molar volumes (φ_v) have been calculated from the density data at different temperatures and fitted to Massons relation to get limiting partial molar volumes (? _v ⁰ ) of CAN. Refractive index data were fitted to linear dependence over concentration of solutions and values of constant K and n _D ⁰ for different temperatures were evaluated. Specific refractions (R _D) of solutions were calculated from the refractive index and density data. Concentration and temperature effects on experimental and derived properties have been discussed in terms of structural interactions.     

Excess molar volumes at 298.15 K of binary liquid organic mixtures containing n-alkanones and linear ethers: Application of Flory’s theory

Excess molar volumes, V_m^E, at 298.15 K and atmospheric pressure over the entire composition range for binary mixtures of 2-butanone with di-n-butyl ether and 2-pentanone and 3-pentanone with di-n-butyl ether and 2,5-dioxahexane, 2-heptanone and 4-heptanone with di-n-butyl ether, 2,5-dioxahexane and 3,6,9-trioxaundecane are reported from densities measured with a vibrating-tube densimeter. All the excess volumes present strong contractions when compared to those of n-alkanone+n-alkane systems.Molar excess enthalpies H_m^E and V_m^E of the considered mixtures vary similarly. This may be attributed to interactional effects which prevail over structural effects.Flory’s theory has been applied to the systems under study. As expected, results for H_m^E are better when the difference in polarity of the components of the mixture decreases. V_m^E is often poorly represented.     

Excess molar volumes and viscosity deviations of the ternary system of 1-butanol + 2-butanol + 1,3-butanediol at 303.15 K

Abstract  The viscosity and density of ternary mixtures of 1-butanol + 2-butanol + 1,3-butanediol and the binary systems 1-butanol + 2-butanol, 1-butanol + 1,3-butanediol, and 2-butanol + 1,3-butanediol were measured at 303.15 K and atmospheric pressure over the entire range of compositions. Excess molar volumes V ^E and viscosity deviations Δη were obtained from the experimental results for the binary and ternary systems and fitted to Redlich–Kister’s and Cibulka’s equations in terms of mole fractions. The results obtained for the viscosity of liquid mixtures were used to test the semi-empirical relations of Grunberg–Nissan, Hind, and the two-parameter McAllister, Kendall, and Frenkel equations. The experimental data for the ternary system and the constituting binaries are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures. Graphical abstract        

Partial molar volume and partial molar compressibility of four homologous α-amino acids in aqueous sodium fluoride solutions at different temperatures

Density and ultrasonic speed of four amino acids (glycine, l-alanine, l-valine, and l-leucine) in aqueous sodium fluoride solutions {(0.1 to 0.5) M} have been measured at T = (308.15, 313.15, and 318.15) K. Apparent molar volumes (V_φ), partial molar volumes $\left(V_{\phi }^0\right)$, transfer volumes $\left(\mathrm{\Delta }{V}_{\phi }^0\right)$ and hydration number (n_H) are evaluated using density data. Adiabatic compressibility (β_s), change (Δβ_s), and relative change in compressibility (Δβ_s/β₀), apparent molar compressibility (K_φ), partial molar compressibility $\left(K_{\phi }^0\right)$, transfer compressibility $\left(\mathrm{\Delta }{K}_{\phi }^0\right)$, and hydration number (n_H) have been calculated using ultrasonic speed data. The linear correlation of $V_{\phi }^0\text{,}\mathrm{\Delta }{V}_{\phi }^0\text{,}{K}_{\phi }^0$ and $\mathrm{\Delta }{K}_{\phi }^0$ for a homologous series of amino acids have been used utilised to calculate the contribution of charged end groups (${\text{NH}}_3^{+}$, COO^?), CH₂ group and other alkyl chain of the amino acids. The analysis shows that the ion–ion interactions are much stronger than ion–hydrophobic interactions over the entire concentration range of sodium fluoride. It is observed that sodium fluoride has a strong dehydration effect on amino acids.     

Isothermal vapor–liquid equilibrium at 333.15 K and excess molar volumes and refractive indices at 298.15 K for the mixtures of di-methyl carbonate,ethanol and 2,2,4-trimethylpentane

Isothermal vapor–liquid equilibrium data at 333.15 K are measured for the binary system ethanol + 2,2,4-trimethylpentane and for ternary system di-methyl carbonate (DMC) + ethanol + 2,2,4-trimethylpentane by using headspace gas chromatography. The experimental binary and ternary vapor–liquid equilibrium data were correlated with different activity coefficient models. Excess volume and deviations in molar refractivity data are also reported for the binary systems DMC + ethanol and DMC + 2,2,4-trimethylpentane and the ternary system DMC + ethanol + 2,2,4-trimethylpentane at 298.15 K. These data were correlated with the Redlich-Kister equation for the binary systems and the Cibulka equation for the ternary system, respectively. The ternary excess volume and deviations in molar refractivity data were also compared with estimated values from the binary contribution models of Tsao–Smith, Kohler, Rastogi and Radojkovi?.     

Densities and apparent molar volumes for aqueous solutions of HNO3−UO2(NO3)2 at 298.15 K

In order to obtain the exact information of atomic number density in the ternary system of HNO₃−UO₂(NO₃)₂−H₂O, the densities were measured with an Anton-Paar DMA60/602 digital density meter thermostated at 298.15±0.01 K. The apparent molal volumes for the systems were calculated from the experimental data. The present measured apparent molar volumes have been fitted to the Pitzer ion-interaction model, which provides an adequate representation of the experimental data for mixed aqueous electrolyte solutions up to 6.2 mol/kg ionic strength. This fit yields θ ^V , and ψ ^V , which are the first derivatives with respect to pressure of the mixing interaction parameters for the excess free energy. With the mixing parameters θ ^V , and ψ ^V , the densities and apparent molar volumes of the ternary system studied in this work can be calculated with good accuracy, as shown by the standard deviations.     

Density and excess molar volumes of binary mixtures of sulfolane with methanol,n -propanol,n -butanol,and n -pentanol at 298.15–323.15 K and atmospheric pressure

Densities, ρ and excess molar volumes, V?^E of the binary mixtures of sulfolane, +methanol, +n-propanol,?+n-butanol, and +n-pentanol were measured at temperatures 298.15, 303.15, 308.15, 313.15, and 318.15?K, respectively, covering the whole composition range except methanol at 303.15–323.15?K. The V ^E for the systems were found to be negative and large in magnitude. The values of V ^E of the sulfolane, +n-butanol and sulfolane, +n-pentanol mixtures are being positive at lower and higher mole fractions of the alkanols (x ₂). The magnitudes of the V ^E values of the mixtures are in the order sulfolane?+?methanol?>?sulfolane?+?n-propanol?>?sulfolane?+?n-butanol?>?sulfolane?+?n-pentanol. The observed values of V ^E for the mixtures have been explained in terms of (i) effects due to the differences in chain length of the alcohols, (ii) dipole–dipole interactions between the polar molecules, and (iii) geometric effect due to the differences in molar volume of the component molecules. These are more noticeable in the case of lower alcohols. All these properties have been expressed satisfactorily by appropriate polynomials.     

Study of the fluorescence of 9,9′-bianthryl in polyvinylalcohol and in polyvinylchloride at 300 K and 80 K

By UV-vis spectroscopy and use of the polarization of the emission, we show that the 9,9′-bianthryl (9,9′BA) symmetrical molecule exhibits an induced fluorescence in polyvinylalcohol (PVA) by hydrogen bonding of the type OH⋯π which depends on considered temperature. This anomalous behaviour does not occur when this molecule is included in a polyvinylchloride, aprotic polymer.     

Excess molar volume measurements of ternary mixtures [2-propanol+ethyl acetate+n-hexane] and their binary constituents at 298.15, 308.15 and 313.15 K

The excess molar volume of the ternary mixture [2-propanol?+?ethyl acetate?+?n-hexane], and its binary constituents; [2-propanol?+?ethyl acetate], [2-propanol?+?n-hexane] and [ethyl acetate?+?n-hexane] were evaluated by the mixtures density measurements over the whole concentration range at three temperatures 298.15, 308.15 and 313.15?K. The excess molar volumes data were fitted to the Redlich–Kister (RK) type equation and the parameters of this equation have been calculated and presented for the studied mixtures.     

Volume properties and structure of aqueous solutions of urea at 263–348 K

The apparent molar volume of urea ? in aqueous solution in the range T = 273–323 K and m = 1–10 (molality) depends linearly on m ^1/2. An equation for ?(m, T) was derived. The partial molar characteristics of urea ? ₂ and water ? ₁ (volume, dilatability, and temperature coefficients of volumes) were calculated. The ?(T) dependences have characteristic points (extrema, inflection points), shifted to the region of lower temperatures for dilute solutions. The ? ₁(T) dependences for 2m and 4m of the urea solution retain the characteristics of the Y ₁(T) of pure water. In these solutions, the proper structure of water is preserved.     

Apparent molar volumes and compressibilities of electrolytes and ions in γ-butyrolactone

The densities of tetraphenylphosphonium bromide, sodium tetraphenylborate, lithium perchlorate, sodium perchlorate and lithium bromide in γ-butyrolactone at (288.15, 293.15, 298.15, 303.15, 308.15 and 313.15) K and speed of sound at 298.15 K have been measured. From these data apparent molar volumes V_Φ at (288.15, 293.15, 298.15, 303.15, 308.15 and 313.15) K and the apparent molar isentropic compressibility K_S,Φ, at T = 298.15 K of the salts have been determined. The apparent molar volumes and the apparent molar isentropic compressibilities were fitted to the Redlich, Rosenfeld and Mayer equation as well as to the Pitzer and Masson equations yielding infinite dilution data. The obtained limiting values have been used to estimate the ionic data of the standard partial molar volume and the standard partial isentropic compressibility in γ-butyrolactone solutions.     

Vapour pressure and thermodynamic properties of hexamethyldisilane at 305–387 K

The Swietoslawski's differential ebulliometer has been minimized to be usable for ca. 13 cm³ of liquid. After a performance test with acetone, the vapour pressure of hexamethyldisilane is determined over the temperature range 304.61–386.74 K. The Antoine equation obtained is log₁₀(P/kPa) = 5.97097 − 1319.85/{(T/K) − 52.96} and the normal boiling point is 385.81 K. The present results agree with literature values of Suga and Seki at 287–310 K and Brockway and Davidson at 293–334 K.     

Viscosity Arrhenius activation energy and derived partial molar properties in of N,N-dimethylacetamide + 2-ethoxyethanol binary mixtures at temperatures from 298.15 K to 318.15 K.

Calculation of excess properties in N,N-dimethylacetamide + 2-ethoxyethanol binary mixtures at (298.15, 308.15 and 318.15) K from experimental density, viscosity and sound velocity values were presented in previous work. Applications of these experimental values to test different correlation equations as well as their corresponding relative functions were also reported. Considering the quasi-equality between the Arrhenius activation energy Ea and the enthalpy of activation of viscous flow ?H*, here we can define partial molar activation energy Ea1 and Ea2 for N,N-dimethylacetamide and 2-ethoxyethanol, respectively, along with their individual contribution separately. Correlation between the two Arrhenius parameters of viscosity in all the domains of composition shows the existence of two main distinct behaviours separated by a stabilised structure in a short range of mole fraction in N,N-dimethylacetamide from 0.14 to 0.45. We add that correlation reveals interesting Arrhenius temperature, which is closely related to the vaporisation temperature in the liquid vapour equilibrium.