Density and Molar Volumes of 1-Butyl-3-methylimidazolium trifluoromethanesulfonate and Methanol Mixtures at Ambient and Saturated Pressures

Abstract

In this work, we present the density of 1-butyl-3-methylimidazolium trifluoromethanesulfonate and methanol binary mixtures {(1 − x)CH₃OH + x[BMIM][TFO]}, at ambient and saturated pressures $\rho (p_{{0{\text{ or }}s}} ,T,w)$/kg·m⁻³, temperatures of T = (278.15 to 413.15) K, and w = (0 to 100) mass percent [or x = (0 to 1) mole fr.]. Measurements were made with an estimated Δρ/ρ =  ± 0.03 % average percent deviation and were carried out using two different densimeters from the Anton Paar company. The obtained values were fit to the polynomial equation and used to calculate the excess $V_{m}^{E}$/cm³·mol⁻¹ and apparent molar volumes V_ϕ/cm³·mol⁻¹ of the investigated binary mixtures. The obtained excess molar volumes $V_{m}^{E}$ were fit to the Redlich–Kister equation. Partial molar volumes ($\overline{V}_{m,i}$) and excess partial molar volumes ($\overline{V}_{m,i}^{E}$)—used to gain insight into solute–solvent interactions—were calculated from the excess molar volumes. The apparent molar volumes of the investigated aqueous and non-aqueous salt solutions in the solvent were defined.