7. (25%) Let u=u(xy) be a function of x and y. (x), g(x), f1(y), and g1(y) are given; K and L
are positive constant. Solve the problem:
Problem 4 (10%) Attached is the phase diagram of a binary A-B system at 101.3 kPa.
(e) Draw the curves of Gibb free energy Vs. composition for both gas and liquid phases at 65℃.