Viscosity, Density, Speed of Sound, and Refractive Index of Binary Mixtures of Organic Solvent + Ionic Liquid, 1-Butyl-3-methylimidazolium Hexafluorophosphate at 298.15 K

The viscosity and refractive index of the solutions of room-temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF 6 ] in tetrahydrofuran, dimethylsulfoxide, methanol, and acetonitrile have been measured at 298.15 K. The density and speed of sound for solutions of [BMIM][PF 6 ] + tetrahydrofuran or dimethylsulfoxide have also been measured. The changes in viscosity and molar refraction, the excess molar volume, and deviation in isentropic compressibility have been adequately fitted to the Redlich−Kister polynomial.