Mass Transfer Principles in Industrial Processes

Posted on Feb 24, 2026 in Chemistry

Interphase Mass Transfer Concepts and Statements

The following is the corrected and proofread version of the original multiple-choice statements. All original content and option letters have been preserved while spelling, grammar, and capitalization have been corrected for clarity and SEO.

  1. 1. Mass transfer in specific industrial conditions may be: b. with no exchange of several different components.
  2. 2. In strictly theoretical absorption equilibrium conditions between the contacted liquid and gas environments: d. a molar stream of molecules to the gaseous phase prevails.
  3. 3. A system in nonequilibrium conditions naturally strives for: d. gaining the component present in shortage with respect to equilibrium.
  4. 4. A pure theoretical diffusion process: d. cannot be met in a forced turbulent flow mode in the bulk.
  5. 5. The convection process in mass transfer: d. is purposefully amplified in industrial conditions.
  6. 6. Unsteady-state diffusion is a specific mass transfer phenomenon characterized by: c. changes in concentration in space over time.
  7. 7. The kinematic diffusivity parameter value used in design calculations: d. provides direct information about diffusion for all other unitary parameters.
  8. 8. Mass transfer in a gas phase is considered to be: b. a process of stage-by-stage transport of the component from the bulk of the gas phase to the interface by means of convection with continuation according to diffusion rules.
  9. 9. The theoretical mass transfer model assuming that turbulent eddies formed within the fluid are so intensive as to prevent the formation of a stagnant boundary film layer at the interface is: c. surface renewal theory (Danckwerts approach).
  10. 10. Gas bubbling through a liquid layer in chemical technology processes is an example of: b. interphase mass transfer coupling unsteady-state diffusion and natural convection.
  11. 11. The mass transfer resistance in one phase during chemical technology process design may be neglected when: c. in the whole fluid layer there is exclusively one concentration corresponding to the 100%.
  12. 12. The hydraulic phenomenon called ‘flooding’ of a packed tower is a consequence of: c. design selection of too intensive operating conditions.
  13. 13. In the case of a multicomponent gas mixture in a given volume of 1 dm3 with homogeneous spatial components, no convection, and isothermal and isobaric conditions, mass transfer intensity will be: b. dependent on concentration gradients — individually for each chemical species.
  14. 14. When the concentration of some component A in the gas phase is higher than the equilibrium concentration (with respect to the liquid phase concentration), one can expect: a. a tendency to obtain an adequate equilibrium concentration distribution.
  15. 15. Packing of various structures introduced into the mass exchanger is responsible for: b. increasing turbulence in both phases and providing support for the liquid phase.
  16. 16. In absorption processes, equilibrium is defined as the composition of both contacting phases which is self-established when the system is: b. in a dynamic state of mass exchange where both mass streams are equal.
  17. 17. The models which assume that turbulent eddies formed inside the fluid are so intensive that they prevent the formation of a stagnant film at the interface can be represented by: b. penetration models.
  18. 18. The driving forces of the interphase mass transfer which occur between both phases can be estimated using: d. the operating line together with equilibrium relations of different shapes.