Thermophysical Properties of Dilute Binary and Ternary Aqueous Solutions of CaCl₂ and NaCl

The precise measurement of thermophysical properties of dilute electrolyte solutions is essential for optimizing numerous industrial processes that require accurate fluid behaviour prediction at low concentrations. This study provides experimental data on the density and viscosity of binary and ternary aqueous solutions of CaCl₂ and NaCl within the dilute concentration range of 0.05–0.3 mol·kg⁻¹ at temperatures of 283.15, 293.15, and 303.15 K. The ternary systems were measured at three different molar ratios (3:1, 1:1, and 1:3) to examine the relative contributions of each salt to solution properties. Experimental results show that CaCl₂ solutions consistently exhibit higher density and viscosity values compared to NaCl solutions at equivalent concentrations, with this difference amplifying as concentration increases due to the divalent nature of calcium ions. Two models were applied to the experimental data: an extended Jones-Dole equation and Exponential Model, both employing an additive approach. The Exponential Model demonstrated superior accuracy with an average absolute deviation of 0.0144% compared to 0.7913% for the Jones-Dole model. In both models, parameters associated with CaCl₂ showed consistently larger values than those for NaCl, confirming the stronger influence of divalent calcium ions on solution viscosity. This work contributes reliable viscosity and density data for dilute electrolyte solutions and validates an effective method for predicting ternary solution properties from binary data.