Densities of {poly(ethylene glycol) + water} over the temperature range (283.15 to 363.15) K

Densities of {poly(ethylene glycol) [PEG] + water} prepared with PEG average molar mass (200, 400, 600, and 1500) g · mol^?1 have been measured over the entire composition range over the temperature range (283.15 to 363.15) K at 10 K intervals using a density meter based on electromagnetically-induced oscillations of a U-shaped glass tube and an inbuilt Peltier thermostat. The density versus temperature data of (PEG + water) at each composition for all PEGs were fit to a simple quadratic equation: ρ/(g · cm^?3) = ρ₀/(g · cm^?3) + a(T/K) + b(T/K)². Fits were observed to be satisfactory at each composition for all four (PEG + water). The excess molar volumes of (PEG + water) are observed to be negative and significant over the entire composition range for all four (PEG + water). Irrespective of the temperature, the maximum absolute excess molar volumes are observed in the water-rich region of the mixture and are found to decrease with increasing temperature. This is attributed to the presence of strong interactions within the (PEG + water). Specifically, it is proposed to be due to the H-bonding interactions between the PEG and the water molecules within the mixtures.     

Ultrasound speeds and molar isentropic compressions of (3-ethoxypropane-1-amine + water) mixtures from T = (283.15 to 303.15) K

Alkoxyamines containing two hydrophilic groups with great affinity to water are multipurpose compounds with important applications, either on theoretical or practical grounds. The thermodynamic characterization of aqueous mixtures of these compounds is scant. Ultrasound speed measurements have been made in 53 mixtures of the aqueous ethoxypropane-1-amine binary system, across the entire composition range and temperatures between T = (283.15 and 303.15) K, at atmospheric pressure. By combining ultrasound speed and density data, values of the isentropic compressibility were derived. Excess molar isentropic compressions were estimated and analytically fitted to Redlich–Kister polynomial equations. Excess partial molar quantities were then calculated including their limiting values, which were obtained from the Redlich–Kister fitting coefficients. The temperature dependences of limiting partial molar isentropic compressions and isobaric expansions were also scrutinized. Compressibility changes associated with different patterns of aggregation and hydration over the whole composition range are identified.     

Thermodynamic investigation of methyl salicylate/1-pentanol binary system in the temperature range from 278.15 K to 303.15 K

Densities (ρ), speeds of sound (u), isentropic compressibilities (k_s), refractive indices (n_D), and surface tensions (σ) of binary mixtures of methyl salicylate (MSL) with 1-pentanol (PEN) have been measured over the entire composition range at the temperatures of 278.15 K, 288.15 K, and 303.15 K. The excess molar volumes (V^E), excess surface tensions (σ^E), deviations in speed of sound (Δu), deviations in isentropic compressibility (Δk_s), and deviations in molar refraction (ΔR) have been calculated. The excess thermodynamic properties V^E, σ^E, Δu, Δk_s, and ΔR were fitted to the Redlich–Kister polynomial equation and the A_k coefficients as well as the standard deviations (d) between the calculated and experimental values have been derived. The surface tension (σ) values have been further used for the calculation of the surface entropy (S^S) and the surface enthalpy (H^S) per unit surface area. The lyophobicity (β) and the surface mole fraction $(x_2^{\text{S}})$ of the surfactant component PEN have been also derived using the extended Langmuir model. The results provide information on the molecular interactions between the unlike molecules that take place at the surface and the bulk.     

Quaternary (liquid + liquid) equilibria for (water + 2-propanol + 1,1-dimethylethyl methyl ether + diisopropyl ether) at the temperature 298.15 K

(Liquid + liquid) equilibrium tie-lines were measured for one ternary system {x₁H₂O + x₂(CH₃)₂CHOH + (1 − x₁ − x₂)CH₃C(CH₃)₂OCH₃} and one quaternary system {x₁H₂O + x₂(CH₃)₂CHOH + x₃CH₃C(CH₃)₂OCH₃ + (1 − x₁ − x₂ − x₃)(CH₃)₂CHOCH(CH₃)₂} at T = 298.15 K and P^∘ = 101.3 kPa. The experimental (liquid + liquid) equilibrium results were satisfactorily correlated by modified and extended UNIQUAC models both with ternary and quaternary parameters in addition to binary ones.     

Volumetric and isentropic compressibility behaviour of aqueous solutions of (polyvinylpyrrolidone + sodium citrate) at T = (283.15 to 308.15) K

The apparent specific volumes and isentropic compressibilities have been determined for polyvinylpyrrolidone in aqueous solutions of sodium citrate by density and sound velocity measurements at T = (283.15 to 308.15) K at atmospheric pressure. The results show a positive transfer volume of PVP from an aqueous solution to an aqueous sodium citrate solution. For low concentrations of PVP, the apparent specific volumes of PVP in water increased along with an increase in the polymer mass fraction, while in aqueous sodium citrate solutions decreased along with an increase in the polymer mass fraction. For high concentrations of PVP, the apparent specific volumes of PVP in water and in aqueous sodium citrate solutions were independent of the polymer mass fraction. The apparent specific isentropic compressibility of PVP is negative at T = (283.15 and 288.15) K, which imply that the water molecules around the PVP molecules are less compressible than the water molecules in the bulk solutions. The positive values of apparent specific isentropic compressibility at T = (298.15, 303.15, and 308.15) K imply that the water molecules around the PVP molecules are more compressible than the water molecules in the bulk solutions. Finally, it was found that the apparent specific isentropic compressibility of PVP increases as the concentration of sodium citrate increases.     

Thermodynamic properties of (tetradecane + benzene, + toluene, + chlorobenzene, + bromobenzene, + anisole) binary mixtures at T = (298.15, 303.15, and 308.15) K

Density ρ, viscosity η, and refractive index n_D, values for (tetradecane + benzene, + toluene, + chlorobenzene, + bromobenzene, + anisole) binary mixtures over the entire range of mole fraction have been measured at temperatures (298.15, 303.15, and 308.15) K at atmospheric pressure. The speed of sound u has been measured at T = 298.15 K only. Using these data, excess molar volume V^E, deviations in viscosity Δη, Lorentz–Lorenz molar refraction ΔR, speed of sound Δu, and isentropic compressibility Δk_s have been calculated. These results have been fitted to the Redlich and Kister polynomial equation to estimate the binary interaction parameters and standard deviations. Excess molar volumes have exhibited both positive and negative trends in many mixtures, depending upon the nature of the second component of the mixture. For the (tetradecane + chlorobenzene) binary mixture, an incipient inversion has been observed. Calculated thermodynamic quantities have been discussed in terms of intermolecular interactions between mixing components.     

Densities and volume properties of (water + tert-butanol) over the temperature range of (274.15 to 348.15) K at pressure of 0.1 MPa

The densities of {water (1) + tert-butanol (2)} binary mixture were measured over the temperature range (274.15 to 348.15) K at atmospheric pressure using “Anton Paar” digital vibrating-tube densimeter. Density measurements were carried out over the whole concentration range at (308.15 to 348.15) K. The following volume parameters were calculated: excess molar volumes and thermal isobaric expansivities of the mixture, partial molar volumes and partial molar thermal isobaric expansivities of the components. Concentration dependences of excess molar volumes were fitted with Redlich–Kister equation. The results of partial molar volume calculations using four equations were compared. It was established that for low alcohol concentrations at T ? 208 K the inflection points at x₂ ≈ 0.02 were observed at concentration dependences of specific volume. The concentration dependences of partial molar volumes of both water and tert-butanol had extremes at low alcohol content. The temperature dependence of partial molar volumes of water had some inversion at х₂ ≈ 0.65. The temperature dependence of partial molar volumes of tert-butanol at infinite dilution had minimum at ≈288 K. It was discovered that concentration dependences of thermal isobaric expansivities of the mixture at small alcohol content and low temperatures passed through minimum.     

Equilibrium solubility of carbon dioxide in (2-amino-2-methyl-1-propanol + piperazine + water)

In this work, a new set of values for the solubility of carbon dioxide in aqueous mixture containing different concentrations of 2-amino-2-methyl-1-propanol (AMP), a sterically-hindered amine, and piperazine (PZ), an activator, are presented. The results were carefully determined using a 1.0 dm³ stainless steel vapour-recirculation equilibrium cell at T = (313.2, 333.2, and 353.2) K, and pressures up to 152 kPa. The AMP concentrations in the ternary (solvent) mixture were (2 and 3) kmol · m^?3; those of PZ’s were (0.5, 1.0, and 1.5) kmol · m^?3. The measured equilibrium loading (solubility)/partial pressure pairs at different temperatures and concentration levels were generally consistent with the corresponding values correlated from the Kent–Eisenberg model that has been adapted for the system in the study, where the parameters of the models were determined using the results from this study and relevant data from literature.     

Mean activity coefficients of NaCl in (sodium chloride + sodium bicarbonate + water) fromT = (293.15 to 308.15) K

The mean activity coefficients of NaCl in (sodium chloride  +  sodium bicarbonate  +  water) were determined experimentally in the temperature range 293.15 K to 308.15 K at four NaHCO₃molality fractions (0.1, 0.3, 0.5, and 0.7). The measurements were made with an electrochemical cell, using a Na ⁺ glass ion-selective electrode and a Cl ⁻ solid-state ion-selective electrode. The experimental values reported by Butler and Huston are found to be higher than those calculated from the Pitzer equation using the existing parameters while the experimental results of this work are close to the calculated values, up to an NaHCO₃molality fraction of 0.5. At the NaHCO₃molality fraction of 0.7, the experimental data are much lower than the calculated values, implying that the interference of HCO₃ ⁻ on the Na ⁺ glass ion-selective electrode can only be neglected up to a molality fraction of NaHCO₃of 0.5, an observation which is consistent with that of Butler and Huston.     

Thermodynamic properties of mixing for (1-alkanol + an-alkane + a cyclic alkane) atT = 298.15 K. I. (n-Hexane + cyclohexane + 1-butanol)

Experimental values of density, refractive index and speed of sound of (hexane  +  cyclohexane  +  1-butanol) were measured at T =  298.15 K and atmospheric pressure. From the experimental data, the corresponding derived properties (excess molar volumes, changes of refractive index on mixing and changes of isentropic compressibility) were computed. Such derived values were correlated using several polynomial equations. Several empirical methods were used in the calculation of the properties of ternary systems from binary data. The Nitta–Chao group contribution model was applied to predict excess molar volume for this mixture.     

Equilibrium solubility of sodium 2-naphthalenesulfonate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures at temperatures from (278.15 to 323.15) K

The equilibrium solubility of sodium 2-naphthalenesulfonate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures was measured at elevated temperatures from (278.15 to 323.15) K using a steady-state method. With increasing temperatures, the solubility increases in aqueous solvent mixtures. The results of these results were regressed by a modified Apelblat equation. The dissolution entropy and enthalpy determined using the method of the least-squares and the change of Gibbs free energy calculated with the values of Δ_diffS^o and Δ_diffH^o at T = 278.15 K.     

Equilibrium solubility of sodium 3-sulfobenzoate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures at temperatures from (278.15 to 323.15) K

The solubility of sodium 3-sulfobenzoate in binary (sodium chloride + water), (sodium sulfate + water), and (ethanol + water) solvent mixtures was measured at elevated temperatures from (278.15 to 323.15) K by a steady-state method. The results of these experiments were correlated by a modified Apelblat equation. The dissolution enthalpy and entropy of sodium 3-sulfobenzoate in aqueous solutions of different mole fraction were obtained.     

(Vapour + liquid) equilibrium in (N,N-dimethylacetamide + ethanol + water) at the temperature 313.15 K

Total vapour pressures, measured at the temperature 313.15 K, are reported for the ternary mixture (N,N-dimethylacetamide + ethanol + water), and for binary constituent (N,N-dimethylacetamide + ethanol). The present results are also compared with previously obtained data for (amide + ethanol) binary mixtures, where amide = N-methylformamide, N,N-dimethylformamide, N-methylacetamide, 2-pyrrolidinone, and N-methylpyrrolidinone. We found that excess Gibbs free energy of mixing for binary (amide + ethanol) mixtures varies roughly linearly with the molar volume of amide.     

Isothermal and isobaric (vapour + liquid) equilibria of (N,N- dimethylformamide + 2-propanol + 1-butanol)

The isothermal and isobaric (vapour  +  liquid) equilibria (v.l.e.) for (N, N - dimethylformamide  +  2-propanol  +  1-butanol) and the binary constituent mixtures were measured with an inclined ebulliometer. The experimental results are analyzed using the UNIQUAC equation with temperature-dependent binary parameters. The comparison between the experimental and literature results for binary systems is given. The ternary v.l.e. values are predicted from the binary results.     

(Vapour + liquid) equilibria for the binary mixtures (1-propanol + dibromomethane,or + bromochloromethane,or + 1,2-dichloroethane or + 1-bromo-2-chloroethane) at T = 313.15 K

Isothermal (vapour + liquid) equilibria (VLE) at 313.15 K have been measured for liquid 1-propanol + dibromomethane, or + bromochloromethane or + 1,2-dichloroethane or + 1-bromo-2-chloroethane mixtures.The VLE data were reduced using the Redlich–Kister equation taking into consideration the vapour phase imperfection in terms of the 2nd molar virial coefficients. The excess molar Gibbs free energies of all the studied mixtures are positive and ranging from 794 J · mol⁻¹ for (1-propanol + bromochloromethane) and 1052 J · mol⁻¹ for (1-propanol + 1-bromo-2-chloroethane), at x = 0.5. The experimental results are compared with modified UNIFAC predictions.     

(Liquid + liquid) equilibria for (water + 1-propanol + diisopropyl ether + octane,or methylbenzene,or heptane) systems at T = 298.15 K

(Liquid + liquid) equilibria (LLE) data were presented for one ternary system of {water + octane + diisopropyl ether (DIPE)} and three quaternary systems of (water + 1-propanol + DIPE + octane, or methylbenzene, or heptane) at T = 298.15 K and p = 100 kPa. The experimental LLE data were correlated with the modified and extended UNIQUAC models. Distribution coefficients were derived from the experimental LLE data to evaluate the solubility behavior of components in organic and aqueous phases.     

(Liquid + liquid) equilibrium of (water + 2-propanol + 1-butanol + salt) systems at T = 313.15 K and T = 353.15 K: Experimental data and correlation

(Liquid + liquid) equilibrium data for the quaternary systems (water + 2-propanol + 1-butanol + potassium bromide) and (water + 2-propanol + 1-butanol + magnesium chloride) were measured at T = 313.15 K and T = 353.15 K. The overall salt concentrations were 5 and 10 mass percent. Ternary (liquid + liquid) equilibrium data for the salt-free system (water + 2-propanol + 1-butanol) were also determined and found to be in good agreement with data from the literature. The NRTL model for the activity coefficient was used to correlate the data. New interaction parameters were estimated, using the Simplex minimization method and a concentration-based objective function. The results are very satisfactory, with root mean square deviations between experimental and calculated compositions of both phases being less than 0.5%.     

Thermodynamic and transport properties of (1-Butanol + 1,4-Butanediol) at temperatures from (298.15 to 318.15) K

Densities and kinematic viscosities have been measured for (1-butanol + 1,4-butanediol) over the temperature range from (298.15 to 318.15) K. The speeds of sound within the temperature range from (293.15 to 318.15) K have been measured as well. Using these results and literature values of isobaric heat capacities, the molar volumes, isentropic and isothermal compressibility coefficients, molar isentropic and isothermal compressibilities, isochoric heat capacities as well as internal pressures were calculated. Also the corresponding excess and deviation values (excess molar volumes, excess isentropic and isothermal compressibility coefficients, excess molar isentropic and isothermal compressibilities, different defined deviation speed of sound and dynamic viscosity deviations) were calculated. The excess values are negative over the whole concentration and temperature range. The excess and deviation values are expressed by Redlich–Kister polynomials and discussed in terms of the variations of the structure of the system caused by the participation of the two different alcohol molecules in the dynamic intermolecular association process through hydrogen bonding at various temperatures. The predictive abilities of Grunberg–Nissan and McAllister equations for viscosities of mixtures have also been examined.     

Thermodynamic and transport properties of (1,2-ethanediol + 1-nonanol) at temperatures from (298.15 to 313.15) K

Densities and kinematic viscosities have been measured for (1,2-ethanediol + 1-nonanol) over the temperature range from (298.15 to 313.15) K. The speeds of sound in those mixtures within the temperature range from (293.15 to 313.15) K have been measured as well. Using the measurement results, the molar volumes, isentropic compressibility coefficients, molar isentropic compressibilities, and the corresponding excess and deviation values (excess molar volumes, excess isentropic compressibility coefficients, excess molar isentropic compressibilities, differently defined deviations of the speed of sound, and dynamic viscosity deviations) were calculated. The excess Gibbs free energies estimated by the use of the UNIQUAC model are also reported. The excess molar volumes and Gibbs free energies are positive, whereas the compressibility excesses are s-shaped. The excess and deviation values are expressed by Redlich–Kister polynomials and discussed in terms of variations of the structure of the system caused by the participation of two different alcohol molecules in the dynamic intermolecular association process through hydrogen bonding. The effect of temperature is discussed. The predictive abilities of the McAllister equation for viscosities of the mixtures under test have also been examined.     

Excess volumes of mixing in (N,N-dimethylacetamide + methanol + water) and (N,N-dimethylacetamide + ethanol + water) at the temperature 313.15 K

Precise excess volumes of mixing measurements at T = 313.15 K are reported over the whole composition range for binary mixtures: (N,N-dimethylacetamide + water), (N,N-dimethylacetamide + methanol), (N,N-dimethylacetamide + ethanol) and for the ternary mixtures (N,N-dimethylacetamide + methanol + water) and (N,N-dimethylacetamide + ethanol + water). For all the systems, large negative deviations from ideality are observed. The binary results have been fitted using the Redlich–Kister type polynomial. The possibility of predicting the ternary results from the binary ones was examined.