BE/B Eng Bachelor of Engineering Bachelor of Chemical Engineering 2

Question 1

In a distillation column, what does the 'reflux ratio' represent?

Accepted Answer

Ratio of liquid returned to distillate withdrawn

Answer

The reflux ratio is the ratio of liquid returned to the top of the column to the distillate product withdrawn.

Question 2

Which dimensionless number characterizes the ratio of inertial forces to viscous forces in fluid flow?

Accepted Answer

Reynolds number

Answer

The Reynolds number (Re = ρvL/μ) is the ratio of inertial to viscous forces and determines whether flow is laminar or turbulent.

Question 3

What is the primary purpose of a heat exchanger's LMTD (Log Mean Temperature Difference)?

Accepted Answer

To determine the average driving force for heat transfer

Answer

LMTD represents the effective average temperature difference driving heat transfer between the two fluid streams.

Question 4

In chemical kinetics, what does a second-order reaction with respect to reactant A mean?

Accepted Answer

The rate is proportional to the square of A's concentration

Answer

A second-order reaction in A means the rate law is r = k[A]², so doubling [A] quadruples the reaction rate.

Question 5

Which equation describes the pressure drop for incompressible fluid flow through a pipe?

Accepted Answer

Darcy-Weisbach equation

Answer

The Darcy-Weisbach equation (ΔP = f·L/D·ρv²/2) applies to both laminar and turbulent incompressible flow in pipes.

BE/B Eng Bachelor of Engineering Practice Test