Vapor Pressure and Dissolution Enthalpy Measurements in Ternary {H₂O + NaCl + Na₂SO₄} System between 298 K and 363 K

Abstract

A nonisothermal static device was used to make measurements of vapor pressures in the ternary {NaCl (1) + Na2SO4 (2) + H2O (3)} system between 298 K and 363 K with molality ratios m 1/m 2 = 1/10 and m 1/m 2 = 1/1. Experimental data were fitted using empirical relation proposed by Appelblat. Dissolution enthalpies of both anhydrous sodium chloride and sodium sulfate in water were also measured up to saturation conditions at 297.8 K, 317.5 K, and 332.4 K (with m 1/m 2 = 1/10, m 1/m 2 = 1/1, and m 1/m 2 = 10/1, respectively) by using a Setaram C80D differential calorimeter. These calorimetric data were used to establish the analytical expressions of Pitzer and NRTL electrolyte's parameters as a function of temperature. The ability of both models to represent both the dissolution enthalpies and the activities of water were tested.

Modeling of CO2 solubility in single and mixed electrolyte solutions using statistical associating fluid theory

“…Figure 4 shows the activity of H 2 O in NaCl + Na 2 SO 4 solutions. At different NaCl/Na 2 SO 4 concentration ratios, our model accurately predicts the H 2 O activities, and suggests that H 2 O activities of this mixed salt solution are not sensitive to the temperature, which is consistent with the experimental data (Marliacy et al 2003). Osmotic coefficients of aqueous NaCl + MgCl 2 solutions are predicted and shown in Figure 5.…”

Thermodynamic representation of the NaCl+Na2SO4+H2O system with electrolyte NRTL model

“…18-20 show the model results for molal dissolution enthalpy for the ternary system at the NaCl to Na 2 SO 4 molality ratios of 0.1, 1 and 10, respectively. The model results show excellent matches between the calculated values and the exper- [12], ( ) m1/m2 = 0.1, Marliacy et al [12], (᭹) data of Na2SO4-H2O [31], ( ) data of NaCl-H2O [16]. imental data.…”

“…Applying the eNRTL model, Marliacy et al [11] obtained very good agreement between experimental and calculated values of dissolution enthalpies and osmotic coefficients for the Na 2 SO 4 + H 2 O binary. Marliacy et al [12] further examined and confirmed the abilities of both the eNRTL model and the Pitzer model to represent simultaneously the dissolution enthalpies and the activities of water for the NaCl + Na 2 SO 4 + H 2 O ternary.…”

“…Tishchenko et al [50] reported data on mean ionic activity coefficient of NaCl in the ternary system with ionic strength at [12], especially at high Na 2 SO 4 concentration. Table 12 shows the experimental solid-liquid equilibrium data for the NaCl + Na 2 SO 4 + H 2 O ternary.…”

“…Robinson et al[51] and Wu et al[52] reported osmotic coefficient data at 298.15 K with ionic strength at (1.08-9.43) molal. Marliacy et al[12] measured vapor pressure and molal dissolution enthalpies with temperature up to 363.15 K and molal ratio of NaCl to Na 2 SO 4 at 0.1, 1 and 10. They also reported water activity data at the experimental conditions.…”