Mass Transfer Operations I & II_Crash Course for Campus Placement Interviews for Chemical Engineering

A: Option A front-loads the checks that can’t be inferred later. Internals orientation and distributor level directly govern wetting and maldistribution, and a dry dP test catches obstructions without risking solvent contamination. Option B sounds disciplined but hydrotesting and filling tell you nothing about distributor skew or rotated packing. Option C assumes thermal profiles will reveal maldistribution, but that only shows up once mass transfer is already compromised. Option D treats instrumentation as the gate, yet clean signals don’t compensate for misinstalled internals.

A: Option D ties the clues together: partial blockage after maintenance causes uneven liquid distribution, local flooding, and a small dP rise with large efficiency loss. Option A explains efficiency loss but usually spikes dP and solvent losses more sharply. Option B affects equilibrium but wouldn’t change column hydraulics. Option C lowers dP rather than increasing it and is tray-specific logic misapplied to packed service.

A: Option A applies the film model cleanly: diffusivity divided by film thickness in consistent units. Option B looks reasonable if you’re thinking turbulence factors, but none were specified and the arithmetic inflates kG. Option C mixes transport and thermodynamic units, a common slip when jumping to overall coefficients. Option D confuses a material property with a rate coefficient, collapsing two distinct concepts.

A: Option C sits outside the PSV’s protection envelope. Relief devices limit pressure, not phase separation quality. Option A and D are classic PSV duties tied to pressure containment. Option B is tempting to exclude, but rapid pressure excursions during foaming are still pressure events the PSV addresses.