We present a predictive model for the saturated water concentration in n-alkanes based on a theoretical equation of state for the hydrocarbon rich phase and a water equation of state for the aqueous phase. By considering a polar or associating component at low concentration in a nonpolar solvent, we can neglect polar or hydrogen bonding interactions in the hydrocarbon rich phase, thus reducing the number of fitted parameters. The approach allows us to determine the intrinsic pure component equation of state parameters independent of polar and associating interactions. As an example, the nonpolar, non-associating equation of state parameters for water are determined by fitting water solubility data in liquid hydrocarbons (carbon numbers (CN) = 4-13, 16) at ambient conditions. Using the PC-SAFT equation of state, a predictive model for the solubility of water in n-alkanes is produced. Comparisons of the model are presented with binary mixture experimental data for methane to decane across a wide range of conditions. Excellent qualitative and good quantitative agreement is exhibited without fitting a binary interaction parameter. The model is then extrapolated to predict water solubility in n-alkanes as a function of temperature, pressure, and carbon number for conditions where experimental data is of questionable validity or unavailable. Implications on the potential model used in molecular simulations are also discussed.