Thermodynamic properties of mixtures containing 1-butyl-2,3-dimethylimidazolium tetrafluoroborate and cyclopentanone or cyclohexanone

The densities, ρ , speeds of sound, u , and molar heat capacities, C P , of 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (1) + cyclopentanone or cyclohexanone (2) mixtures at 293.15, 298.15,303.15 and 308.15 K and excess molar enthalpies, H E of same mixtures at 298.15 K have been measured as a function of composition. The observed ρ , u , and C P values are used to determine excess molar volumes, V E , excess isentropic compressibilities, κ S E and excess heat capacities, C P E . The analysis of V E data in terms of Graph theory has suggested that while 1-butyl-2,3-dimethylimidazolium tetrafluoroborate exists as monomer; cyclopentanone and cyclohexanone exist as mixture of open and cyclic dimer. The analysis of inter-nuclear distances among interacting atoms (predicted by quantum mechanical calculations) also supports the presence of proposed molecular entities in pure and mixed states. It has been observed that V E , κ S E , C P E and H E estimated by Graph theory compare well with their experimental values.