(a) Assuming zero for the binary interaction parameter (k_ij = 0) of the Peng-Robinson equation, estimate the bubble pressure and vapor composition of the pentane + acetone system at x_p = 0.728, 31.9°C.

(b) Assuming a value for the binary interaction parameter (k_ij = 0.11) of the Peng-Robinson  equation, predict whether an azeotrope should be expected in the system CO₂ + ethylene at 222 K. Estimate the bubble-point pressure for an equimolar mixture of these components.