Showing papers in "Journal of Chemical & Engineering Data in 1999"
TL;DR: The solubility of paracetamol (4-hydroxyacetanilide) in 26 solvents in the temperature range from −5 to +30 °C is reported in this article.
Abstract: The solubility of paracetamol (4-hydroxyacetanilide) in 26 solvents in the temperature range from −5 to +30 °C is reported. Paracetamol has a very low solubility in nonpolar and chlorinated hydrocarbons such as toluene and carbon tetrachloride whereas the solubility is very high in solvents of medium polarity such as N,N-dimethylformamide, dimethyl sulfoxide, and diethylamine. Paracetamol is soluble in alcohols, but the solubility decreases with an increase in the length of the carbon chain in the n-alcohol homologous series (methanol to 1-octanol). The solubility of paracetamol in water is much lower than in other polar solvents such as the alcohols. The ideal solubility of paracetamol is calculated, and the activity coefficient in the saturated solutions is estimated.
361 citations
TL;DR: In this paper, the formation data of CO2-rich mixtures in water and aqueous sodium chloride solutions were measured in a transparent sapphire cell by applying an isothermal pressure search method in the temperature range 264 K to 284 K and the pressure range 0.5 MPa to 5.0 MPa.
Abstract: Hydrate formation data of CO2-rich mixtures, three binaries (CO2 + CH4, CO2 + C2H6 and CO2 + N2) and one quaternary (CO2 + CH4 + C2H6 + N2), in water and aqueous sodium chloride solutions were measured. The measurements were carried out in a transparent sapphire cell by applying an isothermal pressure search method in the temperature range 264 K to 284 K and the pressure range 0.5 MPa to 5.0 MPa.
194 citations
TL;DR: In this paper, the authors measured the solubility of two disperse dyes (C. I. Disperse Red 60 and C. I Disperse Blue 60) in supercritical carbon dioxide at pressures up to 35 MPa and temperatures between 313 K and 423 K in a closedloop equilibrium apparatus equipped with a magnetic pump.
Abstract: Solubility of two disperse dyes (C. I. Disperse Red 60 and C. I. Disperse Blue 60) in supercritical carbon dioxide was measured at pressures up to 35 MPa and temperatures between 313 K and 423 K in a closed-loop equilibrium apparatus equipped with a magnetic pump. The solubility increased with pressure at the same temperature. Solubility isotherms were straight and parallel to each other when the logarithm of solubility was plotted versus density of the fluid, whereas the slope of each isotherm decreased with increasing temperature when it was plotted versus the logarithm of density. The experimental data were successfully correlated using two semiempirical equations.
146 citations
TL;DR: In this article, pressure and temperature data of three-phase lines, quadruple points, and critical end points of the binary system carbon dioxide−water were taken in a high-pressure view cell at temperatures between 270 and 305 K and pressures up to 7.4 MPa.
Abstract: Pressure−temperature data of three-phase lines, quadruple points, and critical end points of the binary system carbon dioxide−water were taken in a high-pressure view cell at temperatures between 270 and 305 K and pressures up to 7.4 MPa. The phase equilibria involve both fluid (liquid and vapor) phases and solid phases (hydrate and ice). The present results are in good agreement with most data from the literature. Correlations of the experimental data with Clausius−Clapeyron type equations are given. The literature data are reviewed critically in comparison to the correlations. The global phase behavior of the system carbon dioxide−water is discussed and compared to the phase behavior of similar binary systems.
142 citations
TL;DR: In this article, the enthalpies of sublimation were calculated from the Clausius−Clapeyron equation and the vapor pressure of α-d-glucose, dextrose, d-xylose, dcellobiose, and levoglucosan were measured using the Knudsen effusion technique, in the range of temperatures from 344 to 488 K.
Abstract: The vapor pressures of α-d-glucose (or dextrose), d-xylose, d-cellobiose (or 4-β-d-glucopyranosyl-d-glucopyranose), and levoglucosan (or 1,6-anhydro-β-d-glucopyranose) have been measured using the Knudsen effusion technique, in the range of temperatures from 344 to 488 K. The measurements were all made in the solid sublimation regime, and enthalpies of sublimation were calculated from the Clausius−Clapeyron equation. The vapor pressures may be correlated by ln(P/Pa) = A − B/ (T/K), where A = 53.16, B = 23 382 (±600) for d-glucose (395−406 K), A = 46.29 and B = 19 006 (±375) for d-xylose (370−395 K), and A = 70.30 and B = 36 264 (±5220) for cellobiose (474−488 K). Levoglucosan displayed a solid phase transition at approximately 386 K, and its vapor pressure was affected accordingly. For this material, A = 38.96 and B = 15 049 (±123) in the temperature range 344−386 K and A = 31.19 and B = 12 066 (±709) in the temperature range 386−405 K.
122 citations
TL;DR: In this paper, the authors measured the heat capacities of the alkanolamines monoethanolamine, diethanolamine, diglycolamine, di-2-propanolamines, triethanolamines, N-methyldiethanolamines and 2-piperidineethanol using a differential scanning calorimeter (DSC).
Abstract: Measurements of the heat capacities of the alkanolamines monoethanolamine, diethanolamine, diglycolamine, di-2-propanolamine, triethanolamine, N-methyldiethanolamine, 2-amino-2-methyl-l-propanol, and 2-piperidineethanol were performed from 30 to 80 °C with a differential scanning calorimeter (DSC). The heat capacity of liquid water has been measured to verify the validity of the Cp measurements. The measured Cp of each alkanolamine has been expressed as a function of temperature. The estimated uncertainty of the measured heat capacities including the effect of impurities in a substance with a purity of 95% is ±3%. The measured heat capacities are, in general, of sufficient accuracy for most engineering-design calculations.
122 citations
TL;DR: In this paper, the solubility of chicken egg white lysozyme, crystallized in the tetragonal form was measured in sodium chloride solutions from 1.6 to 30.7 C, using a miniature column solubability apparatus.
Abstract: The solubility of chicken egg white lysozyme, crystallized in the tetragonal form was measured in sodium chloride solutions from 1.6 to 30.7 C, using a miniature column solubility apparatus. Sodium chloride solution concentrations ranged from 1 to 7% (w/v). The solutions were buffered with 0.1 M sodium acetate buffer with the solubility being measured at pH values in 0.2 pH unit increments in the range pH 4.0 to 5.4, with data also included at pH 4.5. Lysozyme solubility was found to increase with increases in temperature and decreasing salt concentration. Solution pH has a varied and unpredictable effect on solubility.
122 citations
TL;DR: Water solubilities, activity coefficients, and vapor pressures of some terpenes and terpenoids were determined from two sets of experiments as mentioned in this paper, and reliability of the results was established from predicted P° values.
Abstract: Water solubilities, activity coefficients, and vapor pressures of some terpenes and terpenoids were determined from two sets of experiments. The first involved liquid−liquid contacting until saturation of an aqueous layer, which gave solubility and activity coefficient at infinite dilution γ∞. The second set involved stripping a solute from a nonsaturated aqueous solution by an air stream. This last experiment gave the product γ∞P° from which vapor pressure P° was deduced. Reliability of the results was established from predicted P° values, and data for 12 compounds are now available. Data obtained at 25 °C showed low solubilities (0.037−0.22 mmol/L) and high activity coefficients (105−106) for terpenes, whereas oxygenated monoterpenes exhibited solubilities 20 orders of magnitude higher, in the range of 2−20 mmol/L and 103−104 for activity coefficients. Vapor pressures ranged from 100 to 550 Pa for terpenes and from 1 to 130 Pa for terpenoids. Attempts to estimate water solubility showed that recent equa...
120 citations
TL;DR: In this article, the Redlich and Kister (1948) polynomial equation was used to derive the binary coefficients and standard deviations between the calculated coefficients and the fit parameters for the binary mixtures of cyclohexanone with n-alkanes and 2,2,4-trimethylpentane.
Abstract: Experimental results of density, refractive index, and viscosity at 298.15, 303.15, and 308.15 K and the speed of sound at 298.15 K are presented for the binary mixtures of cyclohexanone with n-alkanes (C6−C12) or 2,2,4-trimethylpentane over the entire range of mixture composition scale. From these data, excess molar volume VE, deviations in molar refraction ΔR, viscosity Δη, speed of sound Δu, and isentropic compressibility ΔkS have been calculated. These results are further fit to the Redlich and Kister (1948) polynomial equation to derive the binary coefficients and standard deviations between the calculated and the fit parameters. Furthermore, these results are used to study the nature of intermolecular interactions between the mixing components. All the properties have shown a systematic dependence on the chain length of alkanes.
114 citations
TL;DR: In this paper, the authors describe methods that have been used for their measurement and give empirical equations that they have developed for the representation of such data, and give references to the original papers wherein their "similitude equation" for calculating relative diffusion coefficients was applied to experimental data.
Abstract: In this volume on vapor-gas binary diffusion coefficients, the authors describe methods that have been used for their measurement and give empirical equations that they have developed for the representation of such data. The final two-thirds of the book is the Supplement, which gives tables of binary diffusion coefficient data for 221 mixtures calculated from their generalized equation at “normal” pressure and temperatures from 213 K to the normal boiling point. A comparison is made with the somewhat limited experimental values. The main recommendation for this book for an English speaker is that it collects together the results reported in various Russian sources and includes previously unpublished measurements of the authors. It also gives references to the original papers wherein their “similitude equation” for calculating relative diffusion coefficients was applied to experimental data. However, since these references are not readily accessible, it is a matter of regret that the authors did not take the opportunity to explain more clearly the development and application of equation (2.2.7). No comparison is made with the results of other methods that have been proposed for the correlation of binary diffusion coefficients. There are several errors in the book, starting with the equation for Fick’s second diffusion law on p 1. There is no index to the Supplement, which would not be a problem if the systems had been given in a logical manner, but here, for example, “isobutyl alcohol-air” follows “octyl alcoholair” whereas “isobutyl alcohol-nitrogen” precedes “propyl alcohol-nitrogen”. There are many such inconsistencies throughout this section, together with errors such as “tetrachlorobrominemethane-air” (p 86) and “ethyl esterair” (p 84). Also, since the experimental methods employed have different experimental uncertainties, it would have been useful if a note of the actual experimental method or, preferably, an estimate of the uncertainty had been given in the Supplement. Finally, it should be noted that there are very few references post-1980. John H. Dymond University of Glasgow
107 citations
TL;DR: In this article, the Flory−Huggins interaction parameters have been calculated using measured activities, the effect of temperature, molecular weight of PEG and its concentration, and volume change upon mixing on interaction parameter have been considered.
Abstract: Activities of water are reported for aqueous solutions of poly(ethylene glycol) (PEG) with number average molecular weights of 300, 400, 4000, and 6000 are measured at 35, 45, 55, and 65 °C and at various concentrations from 0 to 40 wt % of PEG using vapor-pressure osmometery. A cubic equation in terms of PEG concentrations is sufficient for correlation of activities. Using measured activities, the Flory−Huggins interaction parameters have been calculated. The effect of temperature, molecular weight of PEG and its concentration, and volume change upon mixing on interaction parameter have been considered. Ignoring the volume change of mixing can lead to an average error of 2.5% with a maximum error of 5.3%.
TL;DR: In this article, the authors used a Redlich−Kister type polynomial equation to derive the binary coefficients and estimate the standard deviations between the experimental and calculated quantities, including excess molar volume, VE, deviations in viscosity, Δη, molar refraction, ΔR, speed of sound, Δu, and isentropic compressibility, ΔkS.
Abstract: Density, viscosity, and refractive index data at 298.15, 303.15, and 308.15 K as well as the speed of sound at 298.15 K in the binary mixtures of acrylonitrile with methanol, ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol, heptan-1-ol, and butan-2-ol are presented over the whole range of mixture compositions. From these results, excess molar volume, VE, deviations in viscosity, Δη, molar refraction, ΔR, speed of sound, Δu, and isentropic compressibility, ΔkS have been calculated. These quantities are fitted to a Redlich−Kister type polynomial equation to derive the binary coefficients and estimate the standard deviations between the experimental and calculated quantities.
TL;DR: In this article, the Redlich−Kister type polynomial equation of the third degree was used to derive the binary coefficients of 2-chloroethanol with methyl acetate, ethyl-acetate, propylacetate and butyl acetate.
Abstract: Experimental values of density, viscosity, and refractive index at 298.15, 303.15, and 308.15 K and the speed of sound at 298.15 K in the binary mixtures of 2-chloroethanol with methyl acetate, ethyl acetate, propyl acetate, and butyl acetate are presented over the whole range of mixture composition. From these data, excess molar volume, deviations in viscosity, speed of sound, isentropic compressibility, and Lorenz−Lorentz molar refraction have been calculated. These results are fit to a Redlich−Kister type polynomial equation of the third degree to derive the binary coefficients. The values of standard deviations are estimated for the calculated and experimental data.
TL;DR: In this article, the solubility of lead oxide and copper oxide in subcritical and supercritical water were measured at temperatures from 250 °C to 500 °C and pressures from 26 MPa to 34 MPa, in a flow-type apparatus.
Abstract: The solubilities of lead oxide (PbO) and copper oxide (CuO) in subcritical and supercritical water were measured at temperatures from 250 °C to 500 °C and pressures from 26 MPa to 34 MPa, in a flow-type apparatus. The solubility of lead oxide varied from 351 μmol/kg H2O at 424.9 °C and 25.9 MPa to 4406 μmol/kg H2O at 350.3 °C and 30.2 MPa. The solubility of copper oxide varied from 1.3 μmol/kg H2O at 449.8 °C and 28.0 MPa to 8.0 μmol/kg H2O at 324.9 °C and 28.1 MPa. A hydration reaction model was applied to correlate the data.
TL;DR: In this article, the authors measured the heat capacities of N-methyldiethanolamine aqueous solutions to verify the validity of Cp measurements for alkanolamines.
Abstract: Heat capacities of monoethanolamine, diglycolamine, diethanolamine, di-2-propanolamine, triethanolamine, N-methyldiethanolamine, 2-amino-2-methyl-l-propanol, and 2-piperidineethanol aqueous solutions were measured from 30 to 80 °C with a differential scanning calorimeter (DSC). The mole fractions of alkanolamines studied are 0.2, 0.4, 0.6, and 0.8. Heat capacities of N-methyldiethanolamine aqueous solutions have been measured to verify the validity of Cp measurements for alkanolamine aqueous solutions. The estimated uncertainty of the measured heat capacities is ±3%, including the effect of up to 5% impurities in a substance. An excess molar heat capacity expression using the Redlich−Kister equation for the composition dependence is used to represent the measured Cp of alkanolamine aqueous solutions. For a total of 374 data points, the calculation results for eight alkanolamine solutions give the overall average absolute deviations of 11.9% and 0.29% for the excess molar heat capacity and the heat capacit...
TL;DR: The experimental data were fitted to an Antoine type of equation, ln[P(kPa)] = A − B/[T(K) + C], where A, B, and C are constants and are concentration dependent as discussed by the authors.
Abstract: The vapor pressures of the aqueous desiccants lithium chloride, lithium bromide, calcium chloride, ethylene glycol, propylene glycol, and their mixtures were measured at their typical operating concentrations and at temperatures from 298 K to 313 K. The experimental data were fitted to an Antoine type of equation, ln[P(kPa)] = A − B/[T(K) + C], where A, B, and C are constants and are concentration dependent. Vapor pressure data were further used to predict the effectiveness of dehumidification in liquid desiccant dehumidifiers.
TL;DR: In this paper, the density, refractive index, and speed of sound of the binary mixtures methanol or ethanol plus hexane, heptane, and octane at the temperatures 303.15, 308.15 K and at atmospheric pressure, as a function of mole fraction, have been fitted as a funtion of composition.
Abstract: In this work we present experimental values of the density, refractive index, and speed of sound of the binary mixtures methanol or ethanol plus hexane, heptane, and octane at the temperatures 303.15, 308.15, 313.15, and 318.15 K and at atmospheric pressure, as a function of mole fraction. The experimental results have been fitted as a funtion of composition. A comparison with other experimental data in the literature has been made.
TL;DR: In this paper, the vapor pressures of the supercooled liquid PL for 17 polychlorinated naphthalene congeners were determined as a function of temperature with a gas chromatographic retention time technique.
Abstract: The vapor pressures of the supercooled liquid PL for 17 polychlorinated naphthalene congeners were determined as a function of temperature with a gas chromatographic retention time technique. The method was calibrated with vapor pressure data for polychlorinated biphenyls (PCBs) which had been measured by other techniques. These data were employed to predict temperature-dependent vapor pressures for all polychlorinated naphthalenes (PCNs) from a regression with published retention time indices. Enthalpies of vaporization ΔVAPH and activity coefficients in 1-octanol were calculated for the PCNs and compared with those for polychlorinated biphenyls. Data analysis suggests that the dependence of PL and ΔVAPH on molecular size, as well as the partitioning behavior into 1-octanol of the PCNs, is very similar to that of coplanar PCBs, i.e., those congeners with no or only one chlorine substitution in the ortho positions. The affinity of these chemicals to 1-octanol increases with the degree of chlorination.
TL;DR: In this paper, the characterization of binary systems containing mixtures of n-C16 with branched saturated hydrocarbons of similar, higher, and lower number of carbon atoms is presented.
Abstract: This work aims at extending the characterization of binary systems containing mixtures of n-C16 with branched saturated hydrocarbons of similar, higher, and lower number of carbon atoms. The systems considered are n-C16 with isooctane (2,2,4-trimethylpentane), cyprane (2,2,4,4,6,8,8-heptamethylnonane), pristane (2,6,10,14-tetramethylpentadecane), and squalane (2,6,10,15,19,23-tetracosane). Density, viscosity, refractive index, molar refractivity, excess volume, viscosity deviation function, and refractivity deviation function at 298.15 K are reported. Measured data are correlated with semiempirical models and parameters are reported.
TL;DR: In this paper, the viscosities and densities of nine binary n-alkan-1-ol systems, 1-propanol + 1-butanol, 1 -propanols + 1.5 octanol, 2-decanol, 3-pentanol + 1 octanol and 4-hexanol, were experimentally determined over the entire composition range at temperatures of 293.15 and 298.15 K and at atmospheric pressure.
Abstract: The viscosities and densities of nine binary n-alkan-1-ol systems, 1-propanol + 1-butanol, 1-propanol + 1-pentanol, 1-butanol + 1-pentanol, 1-butanol + 1-nonanol, 1-butanol + 1-decanol, 1-pentanol + 1-octanol, 1-heptanol + 1-octanol, 1-nonanol + 1-decanol, and 1-decanol + 1-undecanol, were experimentally determined over the entire composition range at temperatures of 293.15 K and 298.15 K and at atmospheric pressure. The experimental viscosity data were correlated by the McAllister three-body and four-body models and were used to test the predictive capability of the generalized corresponding state principle (GCSP) method.
TL;DR: In this paper, the Tait equation is used to estimate the liquid density of 28 aromatic hydrocarbons over a temperature and pressure range and a comparison of isothermal compressibilities with available data at P = 0.1 MPa from the literature is also presented.
Abstract: The published experimental data for 28 aromatic hydrocarbons are summarized and reviewed, and the parameters of the Tait equation are given. This equation allows the calculation of smoothed values of either the volume ratio, V(P)/V(Pref), and related properties (relative density, ρ(P)/ρ(Pref), compression, {1 − V(P)/V(Pref)}), or, using density data at atmospheric pressure (Pref = 0.1 MPa) or at saturation (Pref = Psat), the liquid density of the substances over a temperature and pressure range. A comparison of isothermal compressibilities calculated from the Tait equation with available data at P = 0.1 MPa from the literature is also presented.
TL;DR: The results were used to estimate the interaction parameters between each of the three compounds of the systems studied for the NRTL and UNIQUAC models; the estimated interaction parameters were successfully used to predict the equilibrium compositions by the two models as discussed by the authors.
Abstract: Liquid-liquid equilibria for the ternary systems water + acetic acid + ethyl acetate and water + acetic acid + isophorone (3,5,5-trimethyl-2-cyclohexen-1-one) were measured over the temperature range (283 to 313) K. The results were used to estimate the interaction parameters between each of the three compounds of the systems studied for the NRTL and UNIQUAC models. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the two models; experimental data were successfully reproduced. The UNIQUAC model was the most accurate in correlating the overall equilibrium composition of the studied systems. Also the NRTL model satisfactorily predicted the equilibrium composition. Isophorone experimentally resulted in a better extraction capacity for acetic acid and in a lower miscibility with water.
TL;DR: Experimental results of density, refractive index, and viscosity at 298.15, 303.15 and 308.15 K were presented for the binary mixtures of cyclohexanone with benzene,...
Abstract: Experimental results of density, refractive index, and viscosity at 298.15, 303.15, and 308.15 K and speed of sound at 298.15 K are presented for the binary mixtures of cyclohexanone with benzene, ...
TL;DR: In this article, the ternary system and its constituent binary systems were measured at 240, 270, and 330 K and 5 MPa, respectively, and the Peng−Robinson equation of state was used to model the system.
Abstract: Vapor−liquid equilibria were measured for the nitrogen, carbon dioxide, and propane ternary system and its constituent binaries over the temperature range 240 K to 330 K. The binary systems were measured at 240, 270, and 330 K, and the ternary system was studied at 240 K for 2.0 and 13.0 MPa, 270 K for 2.0, 6.0, and 13.0 MPa, and 330 K and 5 MPa. The Peng−Robinson equation of state was used to model the system.
TL;DR: In this paper, the solubilities of hydrogen, nitrogen, and carbon monoxide in dodecane were measured using a static equilibrium cell over the temperature range from 344.3 to 410.9 K at pressures to 13.24 MPa.
Abstract: The solubilities of hydrogen, nitrogen, and carbon monoxide in dodecane were measured using a static equilibrium cell over the temperature range from 344.3 to 410.9 K at pressures to 13.24 MPa. The uncertainty in these measurements is estimated to be less than 0.001 in mole fraction. The data are represented with root-mean-square errors of less than 0.003 mole fraction by the Soave-Redlich-Kwong and Peng-Robinson equations of state when a single empirical interaction parameter, C{sub ij}, is used for each binary system.
TL;DR: In this article, the experimental quantities for the binary mixtures at the temperature 298.15 K were discussed in terms of the nature and type of intermolecular interactions in binary mixture and compared with literature values.
Abstract: Excess molar volumes for {1,4-dioxane or 1,3-dioxolane + cyclohexane} and excess molar enthalpies and isobaric excess molar heat capacities for the binary mixtures {tetrahydrofuran, tetrahydropyran, 1,4-dioxane, or 1,3-dioxolane + cyclohexane or toluene} at the temperature 298.15 K have been determined as a function of mole fraction. The magnitude of these experimental quantities is discussed in terms of the nature and type of intermolecular interactions in binary mixtures. When available, the results have been compared with literature values.
TL;DR: In this article, the authors measured the Isobaric vapor−liquid equilibria for all of the binary and ternary mixtures of 1-propanol, water, and calcium nitrate using a recirculating still.
Abstract: Isobaric vapor−liquid equilibria for all of the binary and ternary mixtures of 1-propanol, water, and calcium nitrate have been measured at 100.00 kPa using a recirculating still. The addition of calcium nitrate to the solvent mixture produced an important salt effect; the azeotrope was removed at salt mole fractions higher than 0.08. The three experimental binary data sets were independently fitted with the electrolyte NRTL model (Mock, B.; Evans, L. B.; Chen, C. C. AIChE J. 1986, 32, 1655−1664), and the parameters of Mock's model were estimated for each binary system. No ternary parameter was required. These parameters were used to predict the ternary vapor−liquid equilibrium using the same model, and the values so obtained agreed well with the experimental ones.
TL;DR: The solubility of disperse dyes, CI disperse red 60 and CI disperse orange 3 in supercritical carbon dioxide have been measured at temperatures from 323.7 K to 413.7K and pressures from 100 bar to 300 bar, using a flow-type equilibrium cell.
Abstract: The solubility of disperse dyes, CI disperse red 60 and CI disperse orange 3 in supercritical carbon dioxide have been measured at temperatures from 323.7 K to 413.7 K and pressures from 100 bar to 300 bar, using a flow-type equilibrium cell. The solubility data are correlated with an expanded liquid model which needs no critical properties of dyes, as well as an empirical equation.
TL;DR: In this article, the ternary system water + 2-aminoethanol + dimethyl sulfoxide and its three constituent binary mixtures were measured at 363.15 K. The experimental binary data were correlated by the NRTL equation with good accuracy.
Abstract: Isothermal vapor−liquid equilibria were measured for the ternary system water + 2-aminoethanol + dimethyl sulfoxide and its three constituent binary mixtures at 363.15 K. The apparatus used was a modified Rogalski−Malanoski equilibrium still. The experimental binary data were correlated by the NRTL equation. The ternary system was predicted using the binary NRTL parameters with good accuracy.
TL;DR: In this paper, a potentiometric study of the protonation of carboxylic acids in different background salts (NaCl, KCl, Me 4 NCl) at different temperatures and ionic strengths was performed.
Abstract: Here we report a potentiometric study (H + -glass electrode) relative to the protonation of carboxylic acids in different background salts (NaCl, KCl, Me 4 NCl), at different temperatures (5 ≤ t ≤ 45 °C) and ionic strengths (NaCl, 0.1 ≤ I ≤ 5; KCl, 0.1 ≤ I ≤ 4.5; Me 4 NCl, 0.1 ≤ I ≤ 3 mol kg -1 ). Dependence on ionic strength was considered using both a Debye-Huckel type equation and the Pitzer equations. Parameters for the dependence on ionic strength of protonation constants (and of activity coefficients) are reported. From the dependence on temperature of protonation constants, the enthalpy formations ΔH o were obtained. Some general relationships for the dependence on medium and on temperature of protonation constants are reported.