P7.24 A feed mixture F of 5 compounds (A, B, C, D, and E)

is fed to an equilibrium stage. The separation requires

addition of a material separating agent S. The output

from the equilibrium stage is two phases. Phase I con-

tains A, B, C, and most of the added S. Phase II con-

tains B, C, D, E, and some S. Write down all material

balance equations using mole fractions and total

molar flows as variables, all phase equilibrium rela-

tionships (in the form x₁ =f(x), and equations

showing that mole fractions must sum to 1. List all