LAUSR

Abstract In the present study experimental data of density, ultrasonic velocity and viscosity of four ionic liquids: 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]), 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim][NTf2]) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([Emim][NTf2]) have been employed to deduce a number of important and useful thermodynamic properties on the basis of theoretical models available. Theoretically, computed properties include adiabatic compressibility, isothermal compressibility, thermal expansion coefficient, acoustic impedance, heat capacities ratio, heat capacity at constant volume, pseudo Gruneisen parameter, internal pressure, energy of vaporization, heat of vaporization, cohesive energy density, solubility parameter, molar sound velocity, molar compressibility, Debye temperature, molecular radius, intermolecular free length and non-linearity parameter for above mentioned pure ionic liquids.