16. (6%) The equilibrium is first-order in both directions. Derive an expression for the concentration of A as a function of time when the initial molar concentrations of A and B are [A]0 and [B]0.

18. (6%) The cxcess Gibbs energy of a certain binary mixture (A + B) is equal to gRTx(1 - x) where g is a constant and x is the mole fraction of a solute A. Find an expression for the chenical potential of A in the mixture. The chemical potential of pure A is μA*.