Excess molar volumes, V-m(E) excess molar enthalpies, H-m(E) and speeds of sound data, u, of 2-pyrrolidinone (i) + benzene or toluene or o- or p- or m-xylene (j) binary mixtures have been measured as a function of composition at 308.15 K. Isentropic compressibility changes of mixing, kappa(E)(S) have been determined by employing speeds of sound data. The observed data have been estimated by employing Graph theory (which involves topology of the constituents of the mixtures). It has been observed that V-m(E), H-m(E) and kappa(E)(S) values predicted by Graph theory compare well with their corresponding experimental values. IR studies lend further credence to the nature and extent of interaction of the proposed structures of molecular species in these mixtures. (c) 2009 Elsevier B.V. All rights reserved.