Densities, speeds of sound, viscosities, refractive indices, excess and partial molar properties of binary mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate with formamide at temperatures from 293.15 to 318.15 K

Abstract

Abstract The densities, ρ, speeds of sound, u, viscosities, η and refractive indices, nD of the binary solutions of 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4] with Formamide (FA), including those of pure liquids, have been measured over the whole range of composition at different temperatures (T/K = 293.15 to 318.15) and at atmospheric pressure, p = 101 kPa. The experimental data were used to calculate the excess properties such as excess molar volume, V m E , excess isentropic compressibility, K S E , excess speed of sound, uE, excess molar isentropic compressibility, K s , m E , deviations in viscosity, Δη, deviations in refractive index, ΔϕnD and deviations in molar refraction, ΔRM. These excess parameters were fitted to a Redlich-Kister type polynomial equation. The partial molar volumes and partial molar compressibilities and excess partial molar volumes and excess partial molar compressibilities over the whole composition range; and at infinite dilution were also calculated. The obtained results were interpreted in terms of intermolecular interactions occurring in these mixtures.