Traceable Values for Activity and Osmotic Coefficients in Aqueous Sodium Chloride Solutions at Temperatures from 273.15 to 373.15 K up to the Saturated Solutions

Abstract

We present traceable three-parameter extended Hückel equations for the activity coefficient of sodium chloride and for the osmotic coefficient of water in aqueous NaCl solutions from 273.15 to 373.15 K. In this temperature range, our equations seem to apply within experimental error to all thermodynamic data available for these solutions up to the molality of the saturated solution. Our previous studies (J. Chem. Eng. Data 2017, 62, 2617–2632 and 2019, 64, 16–33) showed that, from 273.15 to 373.15 K, two-parameter Hückel equations can successfully explain the literature results of electrochemical, isopiestic, and cryoscopic measurements at least up to a molality of 0.2 mol·kg–1. The model recommended in this study employs the values of our previous two-parameter model for the ion-size parameter in the original Debye–Hückel equation, B, and for the coefficient of the linear term with respect to the molality, b 1. In addition, it includes a quadratic term with respect to the molality with the coefficient b 2. Both b 1 and b 2 are quadratically dependent on temperature. With the introduction of b 2, our model is able to explain the existing vapor pressure, electrochemical, and solubility data from 273.15 to 373.15 K up to the saturated solution. A comparison with the most important literature values for the activity and osmotic coefficients revealed that the agreement is always at least satisfactory, but is best for temperatures below 363 K. On the basis of these results, our activity and osmotic coefficients are the most reliable values for these thermodynamic quantities so far. We propose this is true also for the values from 363 to 373 K.

Freezing point depression of salt aqueous solutions using the Madrid-2019 model

“…89, is in good agreement with the curves at constant temperature from Ref. 98, especially with that at T = 273 K up to 3 mol kg −1 . Thus, we can conclude that the osmotic coefficient calculated at the freezing depression curves gives a reasonable estimate of the osmotic coefficient at 273 K.…”

“…The experimental data at 273 and 298 K are fairly close to each other. 98 Coherently with this observation, the osmotic coefficient along the freezing depression curve, obtained from the Lewis-Randall expression in conjunction with the experimental data for awat(ΔT) from Ref. 85 and ΔT(m) from Ref.…”

Thermodynamics of solvent-driven water extraction from hypersaline brines using dimethyl ether

“…The standard deviation of experimental uncertainties in water-NaCl mixtures is set to 0.001 for osmotic coefficient measurements (σ osm ) [81,97,98]. The LIQUAC expression for the excess Gibbs free energy of a single solvent mixture is independent of middle-range b ij interaction parameters for solvent-ion pairs.…”

“…parameters (θ 2 = [c 13 , c 14 , b 34 , c 34 ]) are calculated through the regression of osmotic coefficient data for mixtures containing water and NaCl from the Idaho Database of Solution Thermodynamics[81][82][83] and Partanen et al[97,98] …”

Estimation of activity coefficients for aqueous organic redox flow batteries: Theoretical basis and equations

“…The validation dataset for NaCl(aq) was obtained by averaging reported values from Partanen and Partanen (2020) , Gibbard et al. (1974) and Clarke and Glew (1985) .…”