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.     

Densimetric and ultrasonic characterization of pentaerythritol in water and in aqueous NaCl and MgCl2 solutions at different temperatures

The densities at T = (293.15, 298.15, 303.15, 308.15, 310.15, and 313.15) K and sound velocities at T = (298.15 and 310.15) K have been measured for pentaerythritol in pure water and in (1, 5, and 10) wt% aqueous solutions of sodium and magnesium chloride. From these data apparent molar volumes, V_Φ, and the apparent molar isenotropic compressibilities, K_S,Φ, of the polyol have been determined. The limiting apparent molar quantities and corresponding transfer parameters were also obtained and discussed in terms of various solute–solvent and solute–cosolute interactions.     

Density,speed of sound,and refractive index measurements for the binary systems (butanoic acid + propanoic acid,or 2-methyl-propanoic acid) at T = (293.15 to 313.15) K

Density, speed of sound, and refractive index for the binary systems (butanoic acid + propanoic acid, or 2-methyl-propanoic acid) were measured over the whole composition range and at T = (293.15, 298.15, 303.15, 308.15, and 313.15) K. The excess molar volumes, isentropic compressibilities, excess isentropic compressibilities, molar refractions, and deviation in refractive indices were also calculated by using the experimental densities, speed of sound, and refractive indices data, respectively. The Redlich–Kister smoothing polynomial equation was used to fit the excess molar volume, excess isentropic compressibility and deviation in refractive index data. The thermodynamic properties have been discussed in terms of intermolecular interactions between the components of the mixtures.     

Surface and bulk behaviour of some (n-hexane + chloroalkane) mixtures

Surface tensions at the temperatures of (283.15, 288.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K and isothermal (vapour + liquid) equilibrium at the temperatures of (288.15, 298.15, and 308.15) K of n-hexane with 1-chlorobutane or 1-chloropentane mixtures have been measured. Surface tension measurements were carried out with a drop volume tensiometer while the (vapour + liquid) equilibrium was obtained using an all-glass dynamic recirculating type still. Several bulk thermodynamic properties of the studied mixtures have been used together with the experimental measurements to analyse the results. Furthermore, a thermodynamic study of surface formation, including interesting properties such as excess surface compositions and excess properties of surface formation, is also presented.     

Effect of tri-potassium phosphate on volumetric,acoustic, and transport behaviour of aqueous solutions of 1-ethyl-3-methylimidazolium bromide at T = (298.15 to 318.15) K

Density, sound velocity, and viscosity of 1-ethyl-3-methylimidazolium bromide, [Emim][Br], in aqueous solutions of tri-potassium phosphate with salt weight fractions (w_s = 0.00, 0.10, 0.15, and 0.20) have been measured as a function of concentration of [Emim][Br] at atmospheric pressure and T = (298.15, 303.15, 308.15, 313.15, and 318.15) K. The apparent molar volume, isentropic compressibility, apparent isentropic compressibility, and relative viscosity values have been evaluated from the experimental data. The partial molar volume and isentropic compressibility at infinite dilution, and viscosity B-coefficient obtained from these data have been used to calculate the corresponding transfer parameters for the studied IL from water to the aqueous tri-potassium phosphate solutions. Also, an empirical equation was satisfactorily used to correlate the experimental viscosity data.     

Density,speed of sound,refractive index and dielectric permittivity of (diethyl carbonate + n -decane) at several temperatures

Density, speed of sound and refractive index values of (diethyl carbonate  + n -decane), were measured at the temperatures (288.15, 293.15, 298.15, and 308.15) K and atmospheric pressure. In addition, dielectric permittivities have been measured for the same mixture and at the same temperatures except at T =  293.15 K. Excess molar volumes, changes of isentropic compressibility on mixing, changes of refractive index on mixing and changes of dielectric permittivity on mixing were computed from the experimental data. The excess molar volumes were compared with predictions from the Nitta–Chao model.     

Excess molar volumes of the binary mixtures of polyethylene glycol 300 with ethoxyethanols at various temperatures

Densities at T = (293.15, 298.15, 303.15, 308.15, and 313.15) K in the binary liquid mixtures of polyethylene glycol 300 with 2-ethoxyethanol, 2-(2-ethoxyethoxy)ethanol, or 2-{2-(2-ethoxyethoxy)ethoxy}ethanol have been measured over the entire range of mixture compositions. These data have been used to compute the excess molar volumes. The excess molar volumes are negative over the entire range of composition for all studied mixtures. The results are discussed in terms of intermolecular interactions in the bulk binary mixtures.     

Effect of KCl on the volumetric and transport properties of aqueous tri-potassium citrate solutions at different temperatures

Density, speed of sound and viscosity measurements of binary aqueous solutions of tri-potassium citrate were performed from dilute up to near saturated concentration range at T = (293.15, 298.15, 303.15, 308.15, and 313.15) K. Volumetric and transport properties of ternary aqueous solutions of (tri-potassium citrate + KCl) have also been measured within the molality range of KCl (0.05, 0.15, 0.25, 0.35, 0.45, and 0.55) at different temperatures. Apparent molar volume and apparent molar isentropic compressibility have been calculated from the density and speed of sound for binary and ternary aqueous solutions of tri-potassium citrate. Apparent molar volume and apparent molar isentropic compressibility of ternary aqueous solutions of (tri-potassium citrate + KCl) have been correlated with the Redlich–Mayer equation. Viscosity values of ternary aqueous solutions of (tri-potassium citrate + KCl) have been fitted with the Jones–Dole equation. The results obtained have been interpreted in elucidating the effect of tri-potassium citrate on the interaction of KCl–H₂O. Density and viscosity values of ternary aqueous solutions of (tri-potassium citrate + KCl) have been predicted successfully using the methods proposed by Laliberte (2007), Laliberte and Cooper (2004) [9], [10] and Zafarani-Moattar and Majdan-Cegincara (2009) [11].     

Volumetric and compressibility behaviour of poly(propylene glycol) – Amino acid aqueous solutions at different temperatures

Precise density and sound velocity measurements have been carried out for aqueous solutions of PPG725 in the absence and presence of (0.2 and 0.5) mol · kg⁻¹ amino acids: alanine, glycine, serine and proline, and also for aqueous solutions of these amino acids in the absence and presence of 0.01 w/w PPG725 at T = (288.15, 293.15, 298.15, 303.15 and 308.15) K. From the experimental density and sound velocity values, the apparent molar volume and isentropic compressibility have been obtained and extrapolated to infinite dilution. The infinite dilution apparent molar properties for transfer of PPG from water to aqueous amino acids solutions and also those for transfer of amino acids from water to aqueous PPG solutions have been studied. Temperature dependency of the infinite dilution apparent molar volume was utilised to determine structure-breaker or structure-maker effects of the solutes. Hydration numbers of the amino acids in the investigated aqueous solutions have been evaluated from the volumetric and compressibility properties. All results are discussed based on the salting-out aptitude of the amino acids (hydrophilic + hydrophobic) interactions and (hydrophobic + hydrophobic) interactions occurred between PPG and the investigated amino acids.     

Partial molar volumes and partial molar adiabatic compressibilities of a short chain perfluorosurfactant: Sodium heptafluorobutyrate in aqueous solutions at different temperatures

Density and ultrasound measurements of sodium heptafluorobutyrate in aqueous solutions at T = (283.15, 288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15, and 323.15) K have been obtained. From these results partial molar volumes and isentropic partial molar adiabatic compressibilities were calculated. Deviations from the Debye-Hückel limiting law provide evidence for limited association at lower concentrations. The change of the partial molar volume and isentropic partial molar adiabatic compressibility upon aggregation was calculated. Variations of the change of partial molar volumes and isentropic partial molar adiabatic compressibility upon aggregation are discussed in terms of temperature.     

On the density and viscosity of (water + dimethylsulphoxide) binary mixtures

Density and viscosity of (water + dimethylsulphoxide) were measured precisely over the whole composition range at T = (298.15, 303.15, 308.15, 313.15, and 318.15) K. Differences between values from different authors are clarified and more reliable partial molar volumes are obtained.     

Effect of dipotassium hydrogen phosphate on thermodynamic properties of glycine and l-alanine in aqueous solutions at different temperatures

Densities, ρ, speed of sound, u for glycine, l-alanine have been measured in aqueous solutions of dipotassium hydrogen phosphate (DKHP) ranging from 0.2, 0.4, 0.6 and 0.8 mol·kg⁻¹ at temperatures T = (288.15, 298.15, 308.15 and 318.15) K. The different parameters such as apparent molar volume, limiting apparent molar volume, transfer volume, partial molar expansibility have been derived from density data. Experimental speeds of sound data were used to estimate apparent molar adiabatic compressibility, limiting apparent molar adiabatic compressibility, transfer parameter and hydration number. These parameters have been discussed in the light of ion-ion and ion-solvent interactions.     

Apparent molar volumes and compressibilities of selected electrolytes in dimethylsulfoxide

Densities at T = (293.15, 298.15, 303.15, 313.15, 323.15, and 333.15) K and sound velocities at T = 298.15 K of tetraphenylphosphonium bromide, sodium tetraphenylborate, sodium bromide, and sodium perchlorate in dimethylsulfoxide have been measured over the composition range from (0 to 0.3) mol · kg⁻¹. From these data, apparent molar volumes and apparent molar isentropic compressibilities at infinite dilution as well as the expansibilities have been evaluated. The results have been discussed in terms of employing tetraphenylphosphonium tetraphenylborate as a reference electrolyte in splitting the limiting apparent molar volumes and apparent molar isentropic compressibilities into ionic contributions.     

Effects of structural isomerism on solution behaviour of solutes: Apparent molar volumes and isentropic compression of catechol,resorcinal, and hydroquinone in aqueous solution at T = (283.15, 293.15, 298.15, 303.15, and 313.15) K

Effects of structural isomerism on solution behaviour of dihydroxybenzenes were examined through the determination of volumetric properties such as apparent molar volumes, apparent molar isentropic compressions, and isobaric expansions. The isomers were 1,2-dihydroxybenzene (catechol), 1,3-dihydroxybenzene (resorcinol), and 1,4-dihydroxybenzene (hydroquinone). The volumetric properties were determined from accurate density and speed of sound measurements at T = (283.15, 293.15, 298.15, 303.15, and 313.15) K and at various concentrations. Values at infinite dilution of these parameters were obtained by suitable extrapolation procedures. The results are discussed in terms of hydrophobic, hydrogen bonding, and dipole–dipole interactions between the three isomers and water. Catechol was found to have the strongest hydrophilic and the weakest hydrophobic interactions with water among the three isomers.     

Interactions of glycine,L-alanine and L-valine with aqueous solutions of trisodium citrate at different temperatures: A volumetric and acoustic approach

Densities, ρ, and speed of sound, u for glycine, L-alanine and L-valine in (0.2, 0.4, 0.6, and 0.8) mol · kg⁻¹ aqueous solutions of trisodium citrate at T = (288.15, 298.15, 308.15 and 318.15) K have been measured. The different parameters such as apparent molar volume, limiting apparent molar volume, transfer volume, have been derived from density data. Experimental values of the speed of sound were used to estimate apparent molar apparent molar isentropic compression, limiting apparent molar isentropic compression, and transfer parameter. The pair and triplet interaction coefficient have been calculated from transfer parameters.     

Densities,surface tensions,and derived surface thermodynamics properties of (trimethylbenzene + propyl acetate,or butyl acetate) from T = 298.15 K to 313.15 K

Densities (ρ) for binary systems of (1,2,4-trimethylbenzene, or 1,3,5-trimethylbenzene + propyl acetate, or butyl acetate) were determined at four temperatures (298.15, 303.15, 308.15, and 313.15) K over the full mole fraction range. The excess molar volumes (V^E) calculated from the density data show that the deviations from ideal behaviour in the systems (all being positive, excepting 1,2,4-trimethylbenzene + butyl acetate system) become more positive with the temperature increasing. Surface tensions (σ) of these binary systems were measured at the same temperatures (298.15, 303.15, 308.15, and 313.15) K by the pendant drop method, the surface tension deviations (δσ) for all system are negative, and decrease with the temperature increasing. The V^E and δσ are fitted to the Redlich–Kister polynomial equation. Surface tensions were also used to estimate surface entropy (S_σ) and surface enthalpy (H_σ).     

Physical properties of ionic liquids based on 1-alkyl-3-methylimidazolium cation and hexafluorophosphate as anion and temperature dependence

Densities ρ, speeds of sound u, and refractive indices n_D were measured from T = (278.15 to 343.15) K. Dynamic viscosities η were measured from T = (293.15 to 323.15) K. Surface tensions σ were determined from T = (288.15 to 313.15) K. The physical properties data were measured at atmospheric pressure. The coefficients of thermal expansion α_p of the ionic liquids were calculated from the experimental values of the density at several temperatures. The Parachor method was used to predict the densities, the refractive indices, and the surface tensions of the ionic liquids, and a comparison between experimental and predictive values was made at T = 298.15 K.     

Viscosity studies of (l-alanine-, l-proline,l-valine,l-leucine + aqueous KCl/KNO3) solutions at different temperatures

Viscosity coefficients of (l-alanine-, l-proline, l-valine, l-leucine + 2.0 M aqueous KCl/KNO₃) solutions have been determined as a function of amino acid concentration at different temperatures: (298.15, 303.15, 308.15, 313.15, 318.15, and 323.15) K. The trends of variation of viscosity values with increase in the concentration of l-alanine, l-proline, l-valine, and l-leucine in 2.0 M aqueous KCl and 2.0 M aqueous KNO₃ solutions, and temperature have been ascribed to the solute–solvent interactions operative in the solutions.     

Excess molar volume and viscosity deviation for binary mixtures of polyethylene glycol dimethyl ether 250 with 1,2-alkanediols (C3–C6) at T = (293.15 to 323.15) K

In this work, density and viscosity have been determined for (polyethylene glycol dimethyl ether 250 + 1,2-propanediol, or 1,2-butanediol, or 1,2-pentanediol, or 1,2-hexanediol) binary systems over the whole concentration range at temperatures of (293.15, 303.15, 313.15, 323.15) K and atmospheric pressure. Experimental data of mixtures were used to calculate the excess molar volumes V^E, and viscosity deviations Δη. These results were fitted by the Redlich–Kister polynomial relation to obtain the coefficients and standard deviations.     

Effect of temperature on the excess molar volumes of some alcohol + aromatic mixtures and modelling by cubic EOS mixing rules

Densities of the (methanol + benzene), (ethanol + benzene), (methanol + chlorobenzene) and (ethanol + chlorobenzene) mixtures have been measured at six temperatures (288.15, 293.15, 298.15, 303.15, 308.15 and 313.15 K) and 101.33 kPa. Excess molar volumes V^E were determined and fitted by the Redlich–Kister equation. It was observed that in all cases V^E increases with rising of temperature. The values of limiting excess partial molar volumes have been calculated, as well. The obtained results have been analysed in terms of specific molecular interactions present in these mixtures taking into considerations effect of temperature on them. The correlation of V^E binary data was performed with the Peng–Robinson–Stryjek–Vera cubic equation of state (PRSV CEOS) coupled with the van der Waals (vdW1) and CEOS/G^E mixing rule introduced by Twu, Coon, Bluck and Tilton (TCBT). The experimental values of V^E were compared with those estimated by both mixing rules at the temperature range and on each temperature, separately.