Partial molar volumes of organic solutes in water. XIV. Polyhydric alcohols derived from ethane and propane at temperatures T = 298 K to T = 573 K and at pressures up to 30 MPa

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.     

Partial molar volumes of organic solutes in water. XIII. Butanols (aq) at temperatures T = 298 K to 573 K and at pressures up to 30 MPa

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.     

Partial molar volumes of organic solutes in water. XVII: 3-Pentanone(aq) and 2,4-pentanedione(aq) at T = (298 to 573) K and at pressures up to 30 MPa

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.     

Partial molar volumes of organic solutes in water. XVIII: Selected polyethers(aq) and 3,6-dioxa-1-heptanol(aq) at T = (298 to 573) K and at pressures up to 30 MPa

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.     

Partial molar volumes of organic solutes in water. XXIII. Cyclic ketones at T = (298 to 573) K and pressures up to 30 MPa

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.     

Partial molar volumes of organic solutes in water. XV. Butanediols(aq) at temperatures from (298 K to 573 K) and at pressures up to 30 MPa

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.     

Partial molar volumes of organic solutes in water. XXI: Cyclic ethers at temperatures T = (278 to 373) K and at low pressure

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.     

Partial molar volumes of organic solutes in water. XVI. Selected aliphatic hydroxyderivatives(aq) at T =(298 to 573) K and at pressures up to 30 MPa

Density data for dilute aqueous solutions of two diols (1,6-hexanediol, 2,2-dimethyl-1,3-propanediol) and two polyhydric alcohols (2,2-bis(hydroxymethyl)-1,3-propanediol, 1,2,3,4,5-pentanepentaol) 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 T = 573 K and at pressure close to the saturated vapour pressure of water, at pressures between 15 and 20 MPa and at p = 30 MPa. While temperature dependences of partial molar volumes of both diols are monotonous, maxima are observed on the curves for polyhydric alcohols. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter.     

Densities,excess molar volume,isothermal compressibility,and isobaric expansivity of (dimethyl carbonate + n-hexane) systems at temperatures (293.15 to 313.15) K and pressures from 0.1 MPa up to 40 MPa

The densities of dimethyl carbonate, n-hexane and their mixtures were measured for 12 compositions at five different temperatures varying from (293.15 to 313.15) K and over the pressure range of (0.1 to 40) MPa. The densities of pure substances and their mixtures at atmospheric pressure were measured by a vibrating-tube densimeter. The densities at high pressures were measured by a variable-volume autoclave and precise analytical balance. The excess molar volume, isothermal compressibility, and isobaric expansivity were derived from the experimental densities.     

Partial molar volumes of organic solutes in water. VIII. Nitrobenzene and nitrophenols at T=298 K to T=573 K and pressures up to 30 MPa

Density data for dilute aqueous solutions of nitrobenzene and three isomeric nitrophenols (2-, 3-, or 4-nitro-1-hydroxybenzene) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at T=298.15 K up to either T=573.15 K (nitrobenzene, m-nitrophenol) or T=548.15 K (p-nitrophenol) or T=523.15 K (o-nitrophenol) and at either atmospheric pressure, or at pressures close to the saturated vapor pressure of water, and also at p=30 MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter for measurements at elevated pressures and a commercial vibrating-tube cell DMA 602HT for measurements at atmospheric pressure.     

Partial molar volumes of organic solutes in water. XXII. Cyclic ethers at temperatures (298 to 573) K and pressures up to 30 MPa

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.     

Measurements of vapour pressures and saturated-liquid densities for n-butane at T = (280 to 424) K

Fifteen measurements of the vapour pressure and seven measurements of the saturated-liquid density for n-butane were obtained by means of a metal-bellows variable volumometer at T = (280 to 424) K. The mole fraction purity of the n-butane used in the measurements was 0.9997. The expanded uncertainties (k = 2) in temperature, pressure, and density measurements have been estimated to be less than 3 mK, less than 0.8 kPa, and 0.08%, respectively. Throughout the present measurements for n-butane, the vapour-pressure value and saturated-liquid density value at each temperature were determined as average value of the pressures on various volume of the bellows at the same temperature, and as the point of intersection between the isotherm and our vapour-pressure value, respectively. The expanded uncertainties (k = 2) in the present vapour-pressure data and saturated-liquid density data have also been estimated to be less than 1.1 kPa and 0.08%, respectively, except the uncertainty of the saturated-liquid density data at T = 424 K being 0.29% (0.83 kg · m⁻³). Based on the present measurements as input data, the Wagner-type vapour-pressure correlation and the saturated-liquid density correlation were also provided for the systematic comparisons between the present measurements and the literature data.     

Thermodynamics of dibenzo-p-dioxin and 1,2,3,4-tetrachlorodibenzo-p-dioxin fromT = 5 K toT = 490 K

In adiabatic low-pressure and dynamic calorimeters the temperature dependence of the standard molar heat capacity C_{p, m}^oof dibenzo- p -dioxin and 1,2,3,4-tetrachlorodibenzo- p -dioxin have been determined at temperatures in the range T =  5 K to T =  490 K: from T =  5 K to T =  340 K with an accuracy of about 0.2 per cent and with an accuracy of 0.5 per cent to 1.5 per cent between T =  340 K and T =  490 K. The temperatures, enthalpies, and entropies of melting of the above compounds have been determined. The experimental data were used to calculate the thermodynamic functions C_{p, m}^o / R, Δ₀^TH_m^o / (R·K), Δ₀^TS_m^o / R, and Φ_m^o = Δ₀^TS_m^o − Δ₀^TH_m^o / T(where R is the universal gas constant) in the range T →  0 to T =  490 K. The isochoric heat capacity C_{V, m}of both dioxins has been estimated over the range T →  0 to T_fus. The effect of substitution of four hydrogen atoms by chlorine atoms on the lattice and atomic components of the isochoric heat capacity was considered.     

Phase transitions on (liquid + liquid) equilibria for (water + 1-methylnaphthalene + light aromatic hydrocarbon) ternary systems at T = (563, 573, and 583) K

Phase transitions for (water + 1-methylnaphthalene + light aromatic hydrocarbon) ternary systems are observed at their (liquid + liquid) equilibria at T = (563, 573, and 583) K and (8.6 to 25.0) MPa. The phase transition pressures at T = (563, 573, and 583) K were measured for the five species of light aromatic hydrocarbons, o-, m-, p-xylenes, ethylbenzene, and mesitylene. The measurements of the phase transition pressures were carried out by changing the feed mole fraction of water and 1-methylnaphthalene in water free, respectively. Effects of the feed mole fraction of water on the phase transition pressures are very small. Increasing the feed mole fraction of 1-methylnaphthalene results in decreasing the phase transition pressures at constant temperature. The slopes depending on the feed mole fraction for 1-methylnaphthalene at the phase transition pressures are decreased with increasing temperature for (water + 1-methylnaphthalene + p-xylene), (water + 1-methylnaphthalene + o-xylene), and (water + 1-methylnaphthalene + mesitylene) systems. For xylene isomers, the highest and lowest of the phase transition pressures are obtained in the case of p- and o-xylenes, respectively. The phase transition pressures for ethylbenzene are lower than those in the case of p-xylene. The similar phase transition pressures are given for p-xylene and mesitylene.     

Partial molar volumes of organic solutes in water. XXVI. 15-Crown-5 and 18-crown-6 ethers at temperatures (298 to 573) K and pressures up to 30 MPa

Densities of dilute aqueous solutions of two cyclic ethers, viz. 15-crown-5 and 18-crown-6, measured over the temperature range from (298 to 573) K and at pressures up to 30 MPa using an automated flow vibrating-tube densimeter are reported. Standard molar volumes were evaluated from the measured data. Present data were combined with those obtained previously for several cyclic ethers and predictions of standard molar volumes based on group contribution approach were tested and analysed.     

Thermodynamic properties of mixtures of N-methyl-2-pyrrolidinone and methanol at temperatures between 298.15 K and 343.15 K and pressures up to 60 MPa

We report measurements of the speed of sound in mixtures of N-methyl-2-pyrrolidinone and methanol at temperatures between 298.15 K and 343.15 K and at pressures up to 60 MPa. The measurements were made using a dual path pulse-echo apparatus operating at a frequency of 5 MHz. We have also measured the isobaric specific heat capacity of each mixture as a function of temperature at ambient pressure, by means of a Setaram DSC III microcalorimeter. The experimental results have been combined with literature data for the density of the same mixtures as a functions of temperature at ambient pressure to obtain the density, isobaric specific heat capacity, and other thermodynamic properties at temperatures between 298.15 K and 343.15 K and at pressures up to 60 MPa. Detailed comparisons with the literature data are presented.     

Volumetric properties of (an organic compound + di-n-butyl ether) atT = 298.15 K

Excess molar volumes V_m^Eof {di- n -butyl ether (DBE)  +  a monofunctional organic compound} have been determined atT =  298.15 K over the whole composition range by means of a vibrating-tube densimeter. TheV_m^E values were either positive (propylamine, or butylamine, or acetone, or tetrahydrofuran  +  DBE) or negative (methanol, or butanol, or diethyl ether, or cyclopentanone, or acetonitrile  +  DBE). Markedly asymmetric V_m^Ecurves were displayed by (DBE  +  methanol) and (DBE  +  acetonitrile). Partial molar volumes __ V_m^oat infinite dilution in DBE, both from this work and the literature, were analysed in terms of an additivity scheme, and the group contributions thus obtained were discussed and compared with analogous results in water. DBE revealed a greater capability of distinguishing between polar and non-polar solutes, as well as in discriminating differently shaped molecules (unbranched, branched, cyclic). The limiting slopes of apparent excess molar volumes are evaluated and briefly discussed in terms of solute–solute and solute–solvent interactions.     

Excess enthalpies of binary and ternary mixtures containing dibutyl ether (DBE), 1-butanol,and heptane at T = 298.15 K and 313.15 K

Experimental excess molar enthalpies of the ternary systems {dibutyl ether (DBE) + 1-butanol + heptane} and the corresponding binary systems at T = 298.15 K and T = 313.15 K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary and the ternary systems show endothermic character. The experimental data for the binary and ternary systems have been fitted using the Redlich–Kister equation, the NRTL and UNIQUAC models. The values of the standard deviation indicate good agreement between the experimental results and those calculated from the equations.     

(Liquid + liquid) equilibria in {water + acrylic acid + (1-butanol,or 2-butanol,or 1-pentanol)} systems at T = 293.2 K,T = 303.2 K,and T = 313.2 K and atmospheric pressure

(Liquid + liquid) equilibrium (LLE) data for {water + acrylic acid + (1-butanol, or 2-butanol, or 1-pentanol)} at T = 293.2 K, T = 303.2 K, and T = 313.2 K and atmospheric pressure (≈95 kPa) were determined by Karl Fischer titration and densimetry. All systems present type I binodal curves. The size of immiscibility region changes little with an increase in temperature, but increases according to the solvent, following the order: 2-butanol < 1-butanol < 1-pentanol. Values of solute distribution and solvent selectivities show that 1-pentanol is a better solvent than 1-butanol or 2-butanol for acrylic acid removal from water solutions. Quality of data was ascertain by Hand and Othmer-Tobias equations, giving R² > 0.916, mass balance and accordance between tie lines and cloud points. The NRTL model was used to correlate experimental data, by estimating new energy parameters, with root mean square deviations below 0.0053 for all systems.     

Enthalpy of solution of CO2 in aqueous solutions of methyldiethanolamine at T = 372.9 K and pressures up to 5 MPa

Experimental enthalpies of solution of CO₂ in aqueous solution of methyldiethanolamine (MDEA) of 15 wt% and 30 wt% are reported. The measurements were performed using a flow calorimetric technique at temperature of 372.9 K and pressures range from 0.5 MPa to 5 MPa. Gas solubilities data at same temperature and pressures were derived from the enthalpy data. Experimental enthalpies of solution are combined with available literature data in order to examine pressure and composition influences.