Free-energy calculations based on molecular simulations provide access to a wide range of thermodynamic properties such as the solubility and partitioning of a molecule in and between various phases. It is demonstrated how molecular dynamics free-energy simulations may be used to obtain the solubilities of primary alcohols and n-alkanes in water and binding affinities of primary alcohols to alpha-cyclodextrin. The equivalence of two distinct routes to calculate binding free energies is shown leading to the conclusion that host-guest binding affinities may be used to probe the underlying molecular force field.