Answer the following statement(s) true (T) or false (F)

Question

A. For a pure component, a cubic equation of state has three molar volume roots. However, for a binary mixture, a cubic equation of state will have four molar volume roots, since the number of components has increased by one.
B. If one models the vapor-phase of a mixture as an ideal solution, this means that the mixture fugacity coefficient of component i will be equal to the pure component fugacity of component i at the mixture temperature and pressure.
C. The van der Waals one-fluid mixing rule requires that the mixture parameters are the same in both the liquid and vapor phases.
D. In modeling vapor-liquid equilibrium using the gamma-phi approach, you can disregard the effect of Poynting correction factor.
E. None of the above are true.

Answer 1

A. Incorrect. A cubic equation can only ever have three roots; the addition of a component does not change the degree of the equation.
B. Correct. This is Equation 12.64 and the surrounding text shows its development.
C. Incorrect. This is not specified anywhere in the model’s development or implementation. Indeed, since the parameters are functions of composition, they will normally not be the same (except at an azeotrope).
D. Incorrect. In the development of gamma-phi modeling, such as in Section 12.2, this is not a simplification that can be made in general since the vapor-phase is not being treated as an ideal gas (indicating a large pressure).
E. Incorrect. One statement is correct; try again.