Densities of Ionic Liquids, 1-Butyl-3-methylimidazolium Hexafluorophosphate and 1-Butyl-3-methylimidazolium Tetrafluoroborate, with Benzene, Acetonitrile, and 1-Propanol at <i>T</i> = (293.15 to 343.15) K

Abstract

Densities of mixtures of 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) with acetonitrile over the entire composition range at T = (293.15 to 343.15) K and with benzene and 1-propanol over the miscible composition range at T = (293.15 to 343.15) K were measured by a vibrating tube densimeter. Density measurements were used to compute the excess molar volumes, VE. The VE values have been fitted to the Redlich−Kister equation. VE values are negative for all the mixtures over the miscible range and become more negative with increasing temperature. The VE values for benzene mixtures are the most negative in the investigation.