The substance l-butyl-3-methylimidazolium (BMIM) hexafluorophosphate (margin) is a liquid at room temperature, even though it is a

Question:

The substance l-butyl-3-methylimidazolium (BMIM) hexafluorophosphate (margin) is a liquid at room temperature, even though it is a salt composed of positive and negative ions. BMIM and other ionic liquids constitute a new class of solvents for organic reactions, because they are capable of dissolving both organic and inorganic substances. More important, they are relatively benign environmentally, or "green." because the) can be easily separated from reaction products and reused virtually indefinitely. Therefore they do not constitute a waste-disposal problem, unlike conventional solvents,
(a) How would you characterize BMIM as a solvent? Polar or nonpolar? Protic or aprotic?
(b) How would changing the solvent from ethanol to BMIM affect the rate of the nucleophilic substitution reaction between sodium cyanide and 1-chloropentane?