BE/B Eng Bachelor of Engineering Bachelor of Chemical Engineering 5

Question 1

In a binary liquid-vapor system, what is an azeotrope?

Accepted Answer

A mixture whose vapor composition equals its liquid composition at a given T and P

Answer

An azeotrope is a mixture where the vapor and liquid have identical compositions, making separation by ordinary distillation impossible.

Question 2

Which dimensionless number represents the ratio of momentum diffusivity to thermal diffusivity in a fluid?

Accepted Answer

Prandtl number

Answer

The Prandtl number (Pr = μcₚ/k = ν/α) is the ratio of kinematic viscosity (momentum diffusivity) to thermal diffusivity.

Question 3

In process design, a 'pinch point' in a heat exchanger network represents:

Accepted Answer

The point where the hot and cold composite curves approach most closely (minimum ΔT)

Answer

The pinch point is where the hot and cold composite curves on a T-H diagram have the minimum temperature approach, setting the minimum utility requirements.

Question 4

What is the purpose of a 'recycle stream' in a chemical process?

Accepted Answer

To return unreacted feed material to the reactor to improve overall conversion

Answer

Recycle streams return unconverted reactants from the separator back to the reactor inlet, increasing the overall conversion per pass through the process.

Question 5

In electrochemical engineering, Faraday's law states that the mass of material deposited or dissolved is proportional to:

Accepted Answer

The total charge passed through the electrolyte

Answer

Faraday's law: m = (M·Q)/(n·F), where the deposited mass is directly proportional to the total charge Q passed through the cell.

BE/B Eng Bachelor of Engineering Practice Test

BE/B Eng Bachelor of Engineering Practice Test

BE/B Eng Bachelor of Engineering Bachelor of Chemical Engineering 5