For refinery light ends processing plant, we need to separate the propane

(1), butane
(2), 1-butene
(3), and pentane
(4) in an isothermal flash unit which operates at 4 bar total pressure.

Using the Raoult’s law assumption calculate the following for a mixture composition of x1 = 0.10, x2 = 0.3, x3 = 0.35, and x4 = 0.25.

a) Calculate the bubble point temperature of the mixture at 4 bar.
b) The composition and amount of each phase produced in an isothermal flash at 4 bar and 25°C if the given composition above is the feed composition.