Problem 4 Use the UNIFAC equation to do the following calculations for the system methanol(1)-aceticacid(2): a) Calculate the Pxy graph for this system at 80 °C. b) Do you expect the volume of the system to expandor to contract upon mixing the pure components? c) Calculate the fugacity of methanol in solution with acetic acid at xMeOH0.8, 80 °C, 0.4 bar.|| d) Repeat the previous calculation at the bubble pressure of the solution instead of 0.4 bar. e) Calculate the chemical potential of methanol in solution with acetic acid at xMeOH = 0.8, 80 °C, 0.4 bar.The reference state is the pure liquid at 80 °C, 0.4 bar. How is your answer affected by the fact that methanolis in the vapor phase at 80 °C, 0.4 bar? f) Repeat the previous part if the reference state is the pure liquid at saturation at 80 °C.Additional data: The saturation pressures of methanol and acetic acid at 80 °C are 1.81 and 0.2763 bar,respectively.