An ideal solution with solute density 1.05 and solvent density 1.00 is subject to a huge gravity force field, a linear function of postition, F=kr, k is a constant and r is the position along the field. Derive the concentration as a function of T and position r along the field. (Hints: express gravitational potential as function of r, Gibbs free energy should be a function of this grav. potential and solute conc. at position r.)
Force is the negative 1st derivative of potential, so the gravitational potential must be U = -k r^2.
The Gibbs energy must then be
G = mu1*+RT ln X1 ...
The answer is given a briefly explained.