In this work the study of the phase equilibrium (experimental and modeled) of three binary mixtures formed by n-hexane and a branched chlorobutane (2-chlorobutane, 1-chloro-2-methylpropane, or 2-chloro-2-methylpropane) is presented. New and consistent experimental vaporliquid equilibrium data at isothermal conditions T = (288.15, 298.15, and 308.15) K have been obtained and correlated using the Wilson equation. In addition, two group contribution models, modified-UNIFAC (universal functional activity coefficient) and VTPR (volume-translated PengRobinson), have been used to predict the vaporliquid equilibrium of the mixtures. The agreement between experimental results and predicted ones is not satisfactory.