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Chemical Engineering :: Mass Transfer

  1. Steam distillation is used for separation of high boiling

  2. A.
    substances from non-volatile impurities.
    B.
    volatile impurity from still higher boiling substances.
    C.
    both (a) and (b).
    D.
    neither (a) nor (b).

  3. The feed to fractionating column is changed from saturated vapour to saturated liquid. If the separation and reflux ratio remains unchanged, the number of ideal stages will

  4. A.
    increase
    B.
    decrease
    C.
    remains same
    D.
    depend on saturated boiling point; may increase or decrease

  5. Rose oil is extracted from rose leaves using __________ distillation.

  6. A.
    high pressure
    B.
    low pressure
    C.
    extractive
    D.
    steam

  7. Hypersorption refers to a __________ process.

  8. A.
    fixed bed absorption
    B.
    moving bed absorption
    C.
    fixed bed adsorption
    D.
    moving bed adsorption

  9. Which of the following is the correct ternery diagram for liquid-liquid extraction system comprising of two pairs partly soluble (e.g., chlorobenzene-water-methyl ethyl ketone system) ?

  10. A.
    B.
    C.
    D.
    None of these.

  11. Extraction of coffee from its seed is done by

  12. A.
    liquid-liquid extraction.
    B.
    leaching.
    C.
    extractive distillation.
    D.
    steam distillation.

  13. In azeotropic mixture, the equilibrium vapour composition is

  14. A.
    more than liquid composition.
    B.
    less than liquid composition.
    C.
    same as liquid composition.
    D.
    independent of pressure.

  15. With lapse of time, the overhead composition of light component in case of batch distillation with constant reflux

  16. A.
    increases
    B.
    decreases
    C.
    remains same
    D.
    may increase or decrease ; depends on system.

  17. Lewis number, which is important in problems involving simultaneous heat and mass transfer, is the ratio of

  18. A.
    mass diffusivity to momentum diffusivity.
    B.
    thermal diffusivity to mass diffusivity.
    C.
    momentum diffusivity to thermal diffusivity.
    D.
    none of these.

  19. According to the film theory of mass transfer, the mass transfer co-efficient is proportional to (where, D = molecular diffusivity)

  20. A.
    D
    B.
    D2
    C.
    D0.5
    D.
    1/D