Partial molar enthalpies of organic solutes in the ionic liquid [EMIM][EtSO4]

Abstract Partial molar excess enthalpies of mixing of the organic liquids methanol, acetonitrile, acetone and propan-1-ol in 1-ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO 4 ]) have been measured using a titration calorimeter. Data have been obtained at 298 K, in the case of methanol also at 308 K, in the mole fraction range of the organic liquid x 2 from 0.005 to 0.05. The results have been extrapolated to infinite dilution for determining enthalpies of dilution at infinite concentrations H ¯ 2 , ∞ E ( x 2  = 0). Alternatively values of H ¯ 2 , ∞ E can be obtained from measurements of activity coefficients γ 2 ∞ at different temperatures using the gas chromatographic or the dilutor technique. However, according to our error analysis calorimetric results of H ¯ 2 E , ∞ are by a factor 2–3 more reliable than the results obtained by the indirect methods.