Densities of the NaNO3 + NaCl + H2O and NaNO3 + KCl + H2O Systems and Their Correlation with the Pitzer Model

• Published in: Journal of chemical and engineering data 2008-12, Vol.53 (12), p.2902-2906
• Main Authors: Lovera, Jorge A, Hernández-Luis, Felipe, Galleguillos, Héctor R
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Solutions
• ISSN: 0021-9568; 1520-5134
• DOI: 10.1021/je800638f

Densities for two ternary systems, NaNO3 (1) + NaCl (2) + H2O (3) and NaNO3 (1) + KCl (2) + H2O (3), have been measured at (20, 25, and 30) °C. The experimental study was carried out for four total ionic strength values, I = I 1 + I 2 ≈ (0.1, 1, 2, and 3) mol·kg−1, and for each total ionic strength, the values of the ionic strength fraction of the NaCl or KCl were y 2 ≈ 0.2, 0.4, 0.6, and 0.8. The parameters of the Pitzer model were fit to the experimental density values. Also, using this model, we determined the volume of mixing (ΔV M) at constant ionic strength and at 25 °C, for the two ternary systems studied in the present work. In general, the values for ΔV M are positive, which indicates that the mixed solutes possess an opposite structural form, resulting in an attraction with an increase in volume in every ternary system.