Consider the following P-V diagram, which shows an isotherm generated using the Van der Waals equation. This isotherm is for a compound with the following Van der Waals parameters: Pam' a = 2.5 mol b = 1.7x10 mal m The temperature of this isotherm is 150 °C. 20 15 10 Pressure (bar) un 1 2 5 6 Vol (L/mol) 7 a. (8 points) Based on the shape of this curve, is the critical temperature of this fluid greater than 150 °C or less than 150 "C? Why? Consider the following P-V diagram, which shows an isotherm generated using the Van der Waals equation. This isotherm is for a compound with the following Van der Waals parameters: Pam a = 2.5 mol b = 1.7x10 - mol The temperature of this isotherm is 150 °C. 20 15 Pressure (bar) 0 -5 1 2. 5 Vol (L/moi ) 6 7 a. 8 points) Based on the shape of this curve, is the critical temperature of this fluid greater than 150 °C or less than 150 °C? Why? b. (12 points) Suppose that you guess that the vapor pressure of this fluid at this temperature is 11 bar. Using the equations for fugacity of a pure fluid obeying Van der Waals' equation, calculate the fugacity of a saturated liquid and saturated vapor at that pressure and the given temperature. Based on your result, is the vapor pressure at this temperature equal to 11 bar? Why or why not? For parts c& d, assume that the vapor pressure of the fluid at 150 °C is 11 bar (regardless of your answer to part b). c. (8 points) What is the compressibility factor (Z) of the fluid at P = 8 bar? d. (12 points) If we assume that liquids are not accurately described by Van der Waals Equation, what is the fugacity of the fluid at 17 bar and 150 °C?
