Recently, we have reported solubility studies of several hydrofluorocarbons (HFCs) (from the methane and ethane series) in room-temperature ionic liquids. The present report is a continuation of such a study to complete the methane and ethane series of HFCs in ionic liquid. The solubilities of fluoromethane, fluoroethane, and 1,1,2,2-tetrafluoroethane in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) have been measured with a gravimetric microbalance in a temperature range of 283.15-348.15 K and pressures up to 2 MPa. Solubility data have been correlated successfully with the Non-Random Two-Liquid (NRTL) activity coefficient model. Also, Henry's law constants for the present gases have been obtained from the solubility data. In this paper, we focus on the thermodynamic properties at infinite dilution. Results are compared and discussed, together with those of other HFCs in our previous report.