Chemical Engineering - MCQ Practice Questions

For a multicomponent gas mixture undergoing absorption with selective removal, the flux of component i is affected by:

In equimolar counter-diffusion between two gases A and B, what is the relationship between their molar fluxes?

The Schmidt number (Sc) in mass transfer is defined as the ratio of:

In a binary gas mixture, if component A is highly soluble in the liquid phase compared to component B, which statement is true regarding absorption?

The Sherwood number (Sh) in mass transfer correlations represents the dimensionless:

For absorption of sparingly soluble gas in a liquid film, the operating line and equilibrium curve relationship determines:

In distillation, the Murphree plate efficiency is always:

A liquid film of thickness δ has a component A diffusing through it with first-order reaction. The Thiele modulus is defined as:

In the penetration theory of mass transfer, the mass transfer coefficient varies with contact time (t) as:

The flux N_A for component A diffusing through stagnant B can be expressed using:

In a packed column used for gas absorption, the NTU (Number of Transfer Units) approach is preferred over HTU when:

For drying of a wet solid in the constant rate period, the controlling mechanism for mass transfer is:

The effective diffusivity in porous solids is given by the Knudsen diffusion model when:

In a wetted wall column for gas absorption, if the gas film resistance is negligible (R_g ≈ 0), the overall mass transfer coefficient K_g is primarily controlled by:

For the absorption of multiple components from a gas stream into an organic solvent, the selectivity depends on:

In evaporative cooling, the heat and mass transfer are coupled. The Lewis number (Le) relationship between them is:

In reverse osmosis (RO), the membrane flux equation (Darcy's law for membranes) predicts that flux is:

For a gas diffusing into a liquid droplet, the internal circulation (if present) causes:

In industrial scale-up of absorption columns, the L/G ratio (liquid to gas ratio) is adjusted to:

For membrane distillation with a hydrophobic membrane, the mass transfer resistance in the gas phase across the membrane pores is overcome by: