Ternary equilibrium data for the mixtures of {water + phosphoric acid + organic solvent (cyclohexane, methylcyclohexane, and toluene)} were determined at T = (308.2 and 318.2) K and atmospheric pressure. Solubility data were determined by the cloud-point titration method. In order to obtain the tie-line data, the concentration of each phase was determined by acidimetric titration, the Karl-Fischer technique, and refractive index measurements. The experimental tie-line data were correlated using the UNIQUAC and NRTL models. The reliability of the experimental data was determined through the Othmer-Tobias and Hand plots. Distribution coefficients and separation factors were evaluated over the immiscibility regions. The Katritzky LSER model was applied to correlate distribution coefficients and separation factors in these ternary systems. (C) 2012 Elsevier Ltd. All rights reserved.