For three binary mixtures composed of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) with 2-propanol, N,N‑dimethylacetamide (DMA) and N,N‑dimethylformamide (DMF), the values of the experimental density and viscosity over the whole composition range for T = (293.15 to 323.15 K) are reported. Excess molar volume VEm, partial molar volume Vi¯¯¯¯¯, and the deviation in viscosity Δη are calculated and explained in order to clarify the intermolecular interactions among the species in the mixtures. For all of the binary mixtures, the negative values of VEm and Δη were fitted with the Redlich–Kister polynomial function. An increase in temperature decreases the values of VEm and increases the values of Δη. The results have been discussed regarding binary interaction forces and the formation of a complex between dissimilar molecules. For the correlation and prediction of the binary system densities, perturbed chain statistical associating fluid theory (PC-SAFT) was used. The results obtained from this theory are consistent with the experimental data.
