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1.
Density data for dilute aqueous solutions of 1,2-ethanediol (ethylene glycol), 1,2-propanediol, 1,3-propanediol, and 1,2,3-propanetriol (glycerol) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298.15 K up to T = 573.15 K and at pressure close to the saturated vapour pressure of water, at pressures close to p = 20 MPa and p = 30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

2.
Density values for dilute aqueous solutions of five cyclic ethers obtained using the Anton Paar DSA 5000 vibrating-tube densimeter and the laboratory-made flow densimeter are presented together with partial molar volumes at infinite dilution (standard partial molar volumes) calculated from the measured results. The cyclic ethers were either five-members cycles with one or two oxygen atoms (oxolane, 1,3-dioxolane) or six-members cycles with one, two, or three oxygen atoms (oxane, 1,4-dioxane, 1,3,5-trioxane). The measurements were performed at temperatures from T = 278 K up to T = 373 K and at either atmospheric pressure or at p = 0.5 MPa. The group contribution method is proposed and values of group contributions are evaluated. Standard partial molar volumes predicted for several other cyclic ethers including large cycles (crown ethers) are compared with available data from the literature.  相似文献   

3.
Density data for dilute aqueous solutions of 1-butanol, 2-butanol, 2-methyl-1-propanol (iso-butanol), and 2-methyl-2-propanol (tert-butanol) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298.15 K up to T = 573.15 K and at pressure close to the saturated vapour pressure of water, at pressures close to p = 20 MPa and p = 30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

4.
Density data for dilute aqueous solutions of two aliphatic ketones (3-pentanone, 2,4-pentanedione) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to either T = 573 K (3-pentanone) or T = 498 K (2,4-pentanedione) and at pressure close to the saturated vapour pressure of water, at pressures between 15 MPa and 20 MPa and at p = 30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

5.
Density data for dilute aqueous solutions of four cyclic ketones (cyclopentanone, cyclohexanone, cycloheptanone, and cyclohexane-1,4-dione) are presented together with standard molar volumes (partial molar volumes at infinite dilution) calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to T = 573 K. Experimental pressures were close to the saturated vapor pressure of water, and (15 and 30) MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter. Experimental standard molar volumes were correlated as a function of temperature and pressure using an empirical polynomial function. Contributions of the molecular structural segments (methylene and carbonyl groups) to the standard molar volume were also evaluated and analyzed.  相似文献   

6.
Densities of dilute aqueous solutions of three branched diols derived from propane-1,3-diol (2-methyl-2-propylpropane-1,3-diol, 2,2-diethylpropane-1,3-diol, and 2-ethyl-2-butylpropane-1,3-diol) and of 3-methylpentane-1,5-diol measured over the temperature range from (298 to 573) K and at pressures up to 30 MPa using a flow vibrating-tube densimeter are reported. Standard molar volumes were evaluated from the measured data. Present data were combined with those obtained previously for related solutes and relations to the structures of solute molecules are discussed. Predictions of standard molar volumes based on group contribution approach were tested and analysed.  相似文献   

7.
Density data for dilute aqueous solutions of four aliphatic ethers (2,5-dioxahexane, 3,5-dioxaheptane, 3,6-dioxaoctane, and 2,5,8-trioxanonane) and one ether-alcohol (3,6-dioxa-1-heptanol) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to either T = 443 K (3,5-dioxaheptane) or T = 573 K (other solutes) and at pressures close to the saturated vapour pressure of water, at pressures between 15 and 20 MPa and at p = 30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

8.
Density data for dilute aqueous solutions of three butanediols (1,3-butanediol, 2,3-butanediol, 1,4-butanediol) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from 298.15 K up to 573.15 K and at pressures close to the saturated vapour pressure of water, at pressures close to 20 MPa and 30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.  相似文献   

9.
The excess molar volumes and the partial molar volumes for (propionitrile + an alkanol) at T = 298.15 K and at atmospheric pressure are reported. The hydrogen bonding between the OH⋯NC groups are discussed in terms of the chain length of the alkanol. The alkanols studied are (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 1-pentanol).The excess molar volume data was fitted to the Redlich–Kister equation The partial molar volumes were calculated from the Redlich–Kister coefficients.  相似文献   

10.
Density values for dilute aqueous solutions of five cyclic ethers (oxolane, 1,3-dioxolane, oxane, 1,4-dioxane, and 1,3,5-trioxane) are presented together with partial molar volumes at infinite dilution calculated from the experimental results. The measurements were performed at temperatures from (298 up to 573) K. Due to thermal decomposition, the upper temperature limit was lower for 1,3-dioxolane (448 K) and 1,3,5-trioxane (498 K). Experimental pressures were close to the saturated vapour pressure of water, and (15 and 30) MPa. The results were obtained using a high-temperature high-pressure flow vibrating-tube densimeter. Experimental standard partial molar volumes were correlated as a function of temperature and pressure using an empirical polynomial function and the semi-theoretical SOCW equation of state. Contributions of the group contribution method proposed previously were also evaluated and analyzed.  相似文献   

11.
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.  相似文献   

12.
Excess molar enthalpies and excess molar volumes at T =  298.15 K andp =  0.1 MPa are reported for (methanol, or ethanol, or 1-propanol  +  1,4-dicyanobutane, or butanenitrile, or benzonitrile). For all the mixtures investigated in this work the excess molar enthalpy is large and positive. The excess molar enthalpy decreases as the carbon chain number of the alkanol species increases from methanol to propanol. The excess molar volumes are both positive and negative. The Extended Real Associated Solution and the Flory–Benson–Treszczanowicz models were used to represent the data. Both these models describe better the excess molar enthalpy than the excess molar volumes of (an alkanol  +  a nitrile compound).  相似文献   

13.
The (p, ρ, T) properties and apparent molar volumes Vϕ of CaCl2 in methanol at T = (298.15 to 398.15) K, at pressures up to 40 MPa are reported, and apparent molar volumes have been evaluated. The experimental (p, ρ, T) values were described by an equation of state. The experiments were carried out at m = (0.10819, 0.28529, 0.65879 and 2.39344) mol · kg−1 of calcium chloride.  相似文献   

14.
Vapour pressures of (tetrahydrofuran + 1,1,2,2-tetrachloroethane, or tetrachloroethene) at nine temperatures between T = 283.15 K and T = 323.15 K were measured by a static method. The reduction of the vapour pressures data to obtain activity coefficients and excess molar Gibbs energies was carried out by fitting the vapour pressure data to the Redlich–Kister polynomial according to Barker’s method. Excess molar volumes were also measured at T = 298.15 K. A comparative analysis about the thermodynamic behaviour of both systems is performed, in terms of hydrogen bonding and electron-donor–acceptor interactions, as well as the resonance effect in tetrachloroethene.  相似文献   

15.
Density data for dilute aqueous solutions of two isomeric aminobenzoic acids and of o -diaminobenzene (1,2-diaminobenzene) are presented together with partial molar volumes calculated from the experimental data. The measurements were performed at temperatures from 298.15 K up to either 498.15 K (aminobenzoic acids) or 573.15 K ( o -diaminobenzene) and at either atmospheric pressure, or at pressures close to the saturated vapour pressure of water, and also at pressure p =  30 MPa. The data were obtained using either a high-temperature and high-pressure flow vibrating-tube densimeter for measurements at elevated pressures or a commercial vibrating-tube cell DMA 602HT for measurements at atmospheric pressure.  相似文献   

16.
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.  相似文献   

17.
This work demonstrated the possibility of hydrophobic ionic liquid tricaprylmethylammonium thiocyanate ([A336][SCN]) as a solvent in the separation by extraction of polyhydric alcohols from their mixtures with water. The knowledge of (liquid + liquid) equilibrium (LLE) of these mixtures is essential for the design of the extraction process. For this reason, the LLE data of the ternary systems {[A336][SCN] + water + glycerol, or ethylene glycol, or 1,2-propanediol, or 1,3-propanediol} were determined at T = 303.2 K and atmospheric pressure. The reliability of the tie-lines data was ascertained by applying the Othmer–Tobias equation, and the non-random two liquid (NRTL) model used to fit the experimental LLE data. The effectiveness of the extraction of polyhydric alcohols from water was evaluated using the solute distribution ratio and the selectivity. The extraction capability of [A336][SCN] was compared with that of other ILs. The results indicated that the [A336][SCN] was suitable for use as a solvent in (liquid + liquid) extraction of polyhydric alcohols from water.  相似文献   

18.
Given the importance that enthalpic and entropic contributions have in the interplay between thermodynamics and self-assembly of aqueous amphiphile systems, the energetic characterisation of the system {water + 1-propoxypropan-2-ol (1-pp-2-ol)} at T = 298.15 K was made by directly measuring excess partial molar enthalpies of 1-pp-2-ol and water, over the entire composition range, at T = 298.15 K and atmospheric pressure. Derivatives of the partial molar properties with respect to the composition are used to improve the understanding of molecular interactions in the water-rich region. The present results were compared with those for the well-studied system {water + 2-butoxyethanol (nC4E1)}, the two amphiphiles being structural isomers.  相似文献   

19.
Densities and ultrasonic velocities of binary mixtures of decan-1-ol with 1,2-dichloroethane, 1,2-dibromoethane, and 1,1,2,2-tetrachloroethene have been measured over the entire range of composition at T = (293.15 and 313.15) K and at atmospheric pressure. From these results, the excess molar volumes, molar free volumes, excess molar isentropic compressibilities, limiting excess partial molar volumes, and isentropic compressibilities, intermolecular free lengths, and available volumes by three methods, thermal expansion coefficients, parameters related to space-filling ability, intermolecular free lengths, and molecular radii have been calculated. The experimental ultrasonic velocities have been analyzed in terms of the ideal mixture relations of Nomoto and Van Dael, Jacobson’s free length, Schaaff’s collision factor, Flory’s statistical, and Prigogine–Flory–Patterson theories and thermoacoustical parameters.  相似文献   

20.
New measurements are reported for the densities of choline chloride: urea (REL) deep eutectic solvent and its aqueous mixtures over the temperature range (298.15 to 323.15) K and pressures up to 50 MPa. The experimental data were used to derive other properties such as isothermal compressibility, isobaric expansivity and excess molar volume. A Tait-type equation was used to correlate accurately the high-pressure density data to temperature, T, pressure, P, and composition, x. The excess molar volumes of {REL (1) + H2O (2)} mixtures were also investigated and represented as a function of all three variables, T, P, x, using an empirical equation. Results indicate that the correlations used in this work can be satisfactorily used to predict the densities of the studied systems at different conditions of temperature, pressure and composition.  相似文献   

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