$4.$The McCabeThiele method is particularly useful for:

a$)$ Designing binary distillation columns

b$)$ Analyzing ternary distillation systems

c$)$ Estimating the optimum reflux ratio

d$)$ Calculating the minimum reflux ratio

Ponchon$-$Savarit method is an alternative to McCabeThiele method and is often used for:

a$)$ Multicomponent distillation

b$)$ Binary distillation only

c$)$ Batch distillation

d$)$ Continuous distillation only

The main purpose of reflux in a distillation column is to:

a$)$ Enhance heat transfer

b$)$ Increase column pressure

c$)$ Provide additional driving force for separation

d$)$ Decrease column diameter

Which of the following is not a factor affecting the choice between continuous and batch distillation?

a$)$ Feed composition

b$)$ Separation requirements

c$)$ Column diameter

d$)$ Energy availability