Excess molar volumes and excess isentropic compressibilities of ternary mixtures containing ionic liquids and cyclic alkanone

This paper reports densities, ρijk and speeds of sound, uijk data of ternary {1-butyl-2,3-dimethylimidazolium tetrafluoroborate (i) + 1-butyl-3-methylimidazolium tetrafluoroborate or 1-ethyl-3-methylimidazolium tetrafluoroborate (j) + cyclopentanone or cyclohexanone (k)} mixtures at temperatures 293.15 K to 308.15 K using a digital densimeter and speed of sound analyser. The observed ρijk and uijk data have been employed to determine excess molar volumes, VijkE and excess isentropic compressiblities, (κSE)ijk respectively of the studied mixtures. The topology of the constituent molecules (Graph theory) of the binary ionic liquid mixtures has recently been utilized (Gupta et al., 2016) to predict their VE, κSE, HE and CpE data. In the present studies, the topology of the components of the ternary mixtures (comprise of two ionic liquids and one organic solvent) has been employed (Graph theory) to obtain expressions for VijkE and (κSE)ijk data that describe well the measured VijkE and (κSE)ijk values. The observed VijkE and (κSE)ijk values have also been tested in terms of Prigogine-Flory-Patterson (PFP) theory. It has been observed that VijkE and (κSE)ijk values predicted by Graph theory are comparable with the experimental values.