Chemical Engineering - MCQ Practice Questions

Which of the following is the correct definition of mass transfer coefficient in a binary diffusion system?

The relationship between mass transfer coefficient and diffusivity is given by the Chilton-Colburn analogy. If diffusivity doubles while other conditions remain constant, how does the mass transfer coefficient change (assuming laminar flow)?

In a distillation column operating at steady state, the mass transfer rate is governed by which of the following equations?

What is the Schmidt number (Sc) in mass transfer? Select the most accurate definition.

A packed column is being used for absorption of SO₂ from air using water. The overall mass transfer coefficient K_L is related to individual coefficients by which relation?

In the film theory of mass transfer, what is assumed about the concentration profile across the stagnant film?

The Sherwood number (Sh) correlates with Reynolds (Re) and Schmidt (Sc) numbers. For flow over a flat plate in laminar regime, which expression is approximately correct?

A textile industry needs to determine the diffusivity of dye in water at 25°C. The Stokes-Einstein equation is: D_AB = kT/(6πμr). What does 'r' represent?

In a counter-current liquid-liquid extraction process, the extraction becomes more efficient when the difference between equilibrium and operating lines increases. What does this signify?

What is the primary assumption made in the penetration theory of mass transfer?

A pharmaceutical company is designing an absorption tower for NH₃ removal from air using H₂SO₄ solution. The Henry's law constant for NH₃ at 25°C is very small. What does this indicate about the system?

For turbulent flow in a pipe, the Colburn analogy for mass transfer is: j_D = (Sh)/(Re × Sc^($\frac{1}{3}$)). Which correlation best estimates j_D for smooth pipes?

In a membrane separation process, the permeance of a membrane is defined as flux per unit driving force. What are the typical units of permeance in SI system?

The mutual diffusivity D_AB of a binary system is NOT a function of which of the following?

A cooling tower is designed for evaporative cooling where water evaporates into dry air. The mass transfer occurs due to:

For simultaneous heat and mass transfer in a wet bulb thermometer, the Lewis number (Le) is defined as Le = Sc/Pr. If Le = 1, what can be inferred?

In a cocurrent absorption tower where gas and liquid flow in the same direction, compared to counter-current operation:

The eddy diffusivity (ε_D) in turbulent flow represents contribution of _____ to overall mass transfer.

A bioprocess company needs to calculate oxygen transfer rate in an aerated bioreactor. The volumetric mass transfer coefficient k_L·a depends on which parameters?

Which statement about the relationship between diffusivity and molar mass is correct according to kinetic theory?