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Chemical Engineering :: Mass Transfer

  1. According to Poiseuille's law, the permeability for gas flow through a capillary is proportional to (where, μ = gas viscosity)

  2. A.
    μ
    B.
    1/μ
    C.
    μ
    D.
    μ2

  3. H2S is being absorbed in a gas absorber unit. The height of the transfer unit based on the overall mass transfer coefficient on the gas side is 0.4 m. The equilibrium data is given by, y = 1.5 x. The bulk concentration of H2S has to be reduced from 0.05 to 0.001 mole fraction in the gas side. The height of the tower (in metres) corresponding to an operating line given by, y = 5x + 0.001 is

  4. A.
    2.0
    B.
    1.56
    C.
    1.0
    D.
    0.56

  5. Packed column distillation is limited to the column __________ metres.

  6. A.
    height < 6
    B.
    diameter < 0.6
    C.
    both (a) & (b)
    D.
    neither (a) nor (b).

  7. For the flow of gases through a capillary, with increase in temperature, the permeability __________ as per Knudsen law.

  8. A.
    increases
    B.
    decreases
    C.
    remains same
    D.
    either (a) or (b); depends on the gas

  9. Which of the following is directly concerned with psychrometry ?

  10. A.
    Lewis reltionship
    B.
    Galileo number
    C.
    Weber number
    D.
    Dean number

  11. Plate efficiency in a distillation column is reduced due to the __________ of liquid.

  12. A.
    entrainment
    B.
    foaming
    C.
    weeping & dumping
    D.
    all (a), (b) & (c)

  13. The most efficient cooling tower out of the following is

  14. A.
    induced draft
    B.
    forced draft
    C.
    natural draft
    D.
    atmospheric

  15. Sodium bicarbonate is produced during soda ash manufacture using a __________ tower.

  16. A.
    plate
    B.
    baffle
    C.
    packed
    D.
    none of these

  17. Powdery materials can be guarded against caking tendency on storage by

  18. A.
    providing irregular grain size.
    B.
    providing minimum percentage of voids.
    C.
    having maximum possible points of contact.
    D.
    none of these.

  19. In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the __________ number.

  20. A.
    Lewis
    B.
    Grashoff
    C.
    Sherwood
    D.
    none of these