Density Prediction for Aqueous Multicomponent Solutions Obeying Isopiestic Relation and Isopycnotic Mixing Rule

The density predictive method based on isopiestic relation has been revised. The accuracy of density prediction based on the isopiestic mixing rule has been compared with that based on the isopycnotic mixing rule on ten aqueous ternary electrolyte systems, one quaternary electrolyte system, and one aqueous ternary nonelectrolyte system at 25°C. Of the ten ternary electrolyte systems, five systems show better predictive accuracy by the isopycnotic method, two by isopiestic relation, and three systems show comparable results. For the aqueous quaternary electrolyte and ternary nonelectrolyte systems, the isopycnotic method gives better predictive accuracy. The overall average error of density prediction based on isopiestic mixing rule is 0.00031, while that based on isopycnotic mixing rule is 0.00017.