Liquid-liquid equilibrium data of the solubility (binodal) curves and tie-line end compositions are presented for mixtures of [water (1) + formic acid, or acetic acid, or propanoic acid, or pentanoic acid (2) + methylcyclohexanol (3)] at T = 293.15 K and P = 101.3 +/- 0.7 kPa. A log-basis approach SERLAS (solvation energy relation for liquid associated system) has been proposed to estimate the properties and liquid-liquid equilibria (LLE) of associated systems containing proton-donating and -accepting and polar components capable of a physical interaction through hydrogen bonding or dipole-dipole interaction. The tie lines were also correlated using the UNIFAC-original model. The reliability of the models has been analyzed against the LLE data with respect to the distribution ratio and separation factor. The proposed model appears to be an improvement in data fit for the ternary systems, yielding a mean error of 22% for all of the systems considered.