<p>Thermal properties and phase equilibria (vapor–liquid, solid–liquid, and liquid–liquid equilibria) of strong aqueous electrolyte systems are computed by applying the excess Gibbs free energy combined with the non-electrolyte UNIQUAC–NRF model [Mazloumi, S.H. Fluid Phase Equilibria, 2016, 417: 70–76] as the short-range term and the Pitzer–Debye–Hückel equation as the long-range forces at different molalities and temperatures. The two binary interaction temperature-dependent adjustable parameters are computed by correlating the experimental data of thermal properties, solubility of salt, liquid–solid, vapor–liquid, and liquid–liquid equilibrium of binary aqueous electrolyte solutions at different molality and temperatures. Applying this model to the methanol–water solution containing the (NO₃, Cl, HCO₃, K, Na, SO₄, (CO₂)₃, NH ₄) ions and hydrocarbons reveals that the non-electrolyte UNIQUAC–NRF model can be an accurate representation of the vapor–liquid, liquid–liquid, solid–liquid equilibrium, and thermal properties in multi-component mixtures by applying the binary interaction parameters.</p>