In a binary mixture, the density of ethanol is 0.7880 g cm^-3 at 20.0⁰C. Its equilibrium vapor pressure at 20.0⁰C is 40.0 torr. Calculate the change in its chemical potential at this temperature and composition, if its pressure is changed from 40.0 torr to 1 atm. (Hint: recall u_j = G_j,m).