Vapor-liquid equilibria (VLE), heat capacities, densities, and viscosities of mixtures of water and 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) and mixtures of water and diethylmethylammonium methane sulfonate ([DEMA][OMs]) were measured in the temperature range T = (293.15 to 353.15) K. VLE measurements were carried out by Fourier transform infrared (FTIR) spectroscopy in a dynamic cell, and the experimental VLE data were correlated to the nonrandom two-liquid (NRTL) model. Measurements of the heat capacity were conducted via differential scanning calorimetry (DSC). The density was measured with a pycnometer and the viscosity with a falling-sphere viscometer.