For the excess Gibbs energy model below. Please derive the following: as a function of x₁:

G^ex = Ax1x₂

a. Demonstrate that this excess Gibbs model results in the one-constant Margules

activity coefficient model (RT In Y₁ = Ax2 and RT ln y₂ = Ax²)

b.

For A = 3.6 RT, what is the composition of phases I and II? (note: a trivial solution

of x= x exists that is not useful)

c.

If a 1 mole of a 60:40 mixture of 1 and 2 is destabilized and phase separates, how

much of phase I and phase II forms (in moles)? Note which component is "rich" in

each phase.