The activity coefficients at infinite dilution (gamma(infinity)(13)) for 33 solutes: alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, and water in the ionic liquid, 1-butyl-1-methylpiperidinium thiocyanate ([BMPIP][SCN]), were determined by gas-liquid chromatography over the temperature range (318.15 to 358.15) K. The partial molar excess enthalpies at infinite dilution values (Delta H(1)(E,infinity)) were calculated from the experimental gamma(infinity)(13) values, obtained over the temperature range. The selectivities for heptane/benzene, cyclohexane/benzene, and heptane/thiophene separation problems were calculated from the gamma(infinity)(13) and compared to the literature values for other ionic liquids with thiocyanate-based anion or with a butyl-methyl-substituted cation.