Low-pressure solubility and thermodynamics of solvation of carbon dioxide, ethane, and hydrogen in 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide between temperatures of 283 K and 343 K

The solubility of carbon dioxide, ethane, and hydrogen was determined experimentally in 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amidea room-temperature ionic liquidas a function of temperature between 283 K and 343 K and close to atmospheric pressure. Carbon dioxide is the most soluble, and hydrogen is the least soluble of the gases studied with mole fraction solubilities of the order of 10(-2) and 10(-4), respectively. All the mole fraction solubilities decrease with increasing temperature, behavior typical of exothermal processes of solvation. From the variation of Henry's law constants with temperature, the partial molar thermodynamic functions of solvation, such as the standard Gibbs energy, the enthalpy, and the entropy, are calculated. The total uncertainty of the experimental data is in all cases better than +/- 3 %.