1. A salt (sodium chloride) crystal dissolves in fresh water but not in air. What does that say about the relative value of the chemical potential of a sodium or chloride ion in air, in a salt crystal, and in water?
2. A certain sugar has a chemical potential of - 1 .I eV in water and -0.8 eV in oil. Suppose that some of this sugar is dissolved in oil and you wish to remove it. Can you suggest a way to do it, taking advantage of the difference in the two chemical potentials?