The activity coefficients at infinite dilution, gamma(infinity)(13) for 29 solutes, alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols and water in the ionic liquid 1-ethyl-3-methylimidazolium trifluoroacetate ([EMIM][TFA]), were determined by gas-liquid chromatography at temperatures from 298.15-368.15 K. The partial molar excess enthalpies at infinite dilution Delta H-1(E,infinity) values were calculated from the experimental gamma(infinity)(13) values obtained over the temperature range. The selectivities for the hexane/benzene and cyclohexane/benzene separation were calculated from gamma(infinity)(13) and compared to the literature values for other ionic liquids, NMP and sulfolane.