What assumptions are made in order to perform the McCabe$-$Thiele method for binary

distillation? Why do we need to make these assumptions?

b$)$ Why is the operating line above$/$below the equilibrium line curve for $1)$ Absorbers, $2)$

Strippers, and $3)$ Distillation?

c$)$ Using only material balance, how can we calculate the slope of q$-$line in the case of

subcooled liquid? Is it possible? If yes, derive an equation for the slope. If no$,$ list out all

of the necessary variables required for calculating the slope.

d$)$ Is it possible that the q$-$line is parallel to the $45\backslash$deg line? What is the physical meaning of this

incident?

e$)$ Explain the economic trade$-$off between trays and reflux in a distillation column