Derive the formulas for the spinodal curves of the Flory-Huggins model and plot the spinodals (T versus x^α, x^β) of several polystyrenes in cyclohexane using UNIFAC parameters to estimate the volume of polystyrene relative to ethylbenzene and taking the experimental values of solubility parameters and molar volumes for the species when N_d = 1. Take the degrees of polymerization of polystyrene to be 100, 200, 500, 1000. Plot the estimated reciprocal critical temperatures versus N_d =1/2. Mark the infinite molecular weight critical temperature on both plots with a big X.