If water and vegetable oil are added to a bowl, they do not mix. If gasoline and vegetable oil are added in another bowl, they _do_ mix. this has something to do with the polarity of the molecules, i.e. water is polar and gasoline and vegetable oil are unpolar. But is it possible to explain this in terms of thermodynamics? When mixing two solutions, water and veg. oil, the entropy ought to increase, and so it should be spontaneous. Our daily life experience tells us that it is not. Why?