New experimental data for the ternary systems of 1-butyl 3- methylimidazolium nitrate ([Bmim][NO3]) or 1-methyl 3-octylimidazolium nitrate ([Omim][NO3]) + alkane (hexane or heptane or octane) + aromatic (ethyl benzene or p-xylene) at 298.15 K and atmospheric pressure are reported. The aromatic selectivity and distribution coefficient are calculated from experimental data. The effect of alkyl chain length of ionic liquids as well as alkane on the aromatic selectivity is studied. The selectivity values for the studied systems with [Bmim][NO3] is more than [Omim][NO3]. The reliability of the experimental data is tested with the Othmer-Tobias and Hand equations. The NRTL thermodynamic model was successfully used to correlate the experimental data. (c) 2015 Elsevier B.V. All rights reserved.