Chapter 2: Binary Systems

Question 1

What is vapour pressure?

Answer 1

Pressure of vapour of a pure liquid at equilibrium or saturation

Question 2

What does vapor pressure depend on?

Answer 2

Temperature

Question 3

What is heat capacity?

Answer 3

The change in energy of a fluid that results from a unit change in
temperature.

Question 4

What does heat capacity usually vary with?

Answer 4

Temperature

Question 5

What happens when the fluid is heated or cooled?

Answer 5

It absorbs/releases heat.

Question 5

What happens to the heat capacity if the fluid doesn’t undergo a phase change when heated or cooled?

Answer 5

This amount of heat is proportional to
the heat capacity

Question 6

What happens to the heat capacity if the fluid undergoes a phase transition when heated or cooled?

Answer 6

Then additional energy is
absorbed/released do to the transition of the molecules from one phase to another

Question 7

What happens as the relative volatility exceeds unity?

Answer 7

The more α exceeds unity, the
greater is the separation
achieved by distillation.

Question 8

How will raising the pressure in a flash drum separating a multi-component mixture affect the drum diameter and relative volatilities?

Answer 8

Decrease the drum diameter and decrease the relative volatilities.

Question 9

What type of condition is flash distillation operated under?

Answer 9

Adiabatically

Question 10

Flash distillation is usually operated adiabatically. Where does the
energy to vaporize part of the feed come from?

Answer 10

The liquid is superheated when the pressure drops, and the energy comes from the amount of
superheat.