|In this thesis a method for calculating the second osmotic virial coefficient is described. This approach is applied to aqueous solutions of methane and various other hydrophobic particles as well as solutions of three biologically relevant molecules (methanol, urea and trimethylamine oxide) for a wide temperature-range. The structure of the surrounding water molecules is studied in detail to investigate solvent effects. For methane the temperature and pessure behavior. The influence of the chosen water force field is shown alongside a comparison of various different water models.