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Chemical Engineering :: Mass Transfer

  1. Small dia distillation column can be a

  2. A.
    packed column
    B.
    sieve tray
    C.
    bubble cap
    D.
    any of these

  3. An air-water vapour mixture has a dry bulb temperature of 60°C and a dew point temperature of 40°C. The total pressure is 101.3 kPa and the vapour pressure of water at 40°C and 60°C are 7.30 kPa and 19.91 kPa respectively.The humidity of air sample expressed as kg of water vapour/kg of dry air is

  4. A.
    0.048
    B.
    0.079
    C.
    0.122
    D.
    0.152

  5. __________ column is used in gas absorption process.

  6. A.
    Wetted wall
    B.
    Seive/perforated tray
    C.
    Bubble cap
    D.
    Packed

  7. Nitrobenzene (boiling point = 210.6°C) is steam distilled at 1 atm pressure.Nitrobenzene will distill off __________ °C.

  8. A.
    at < 100
    B.
    at > 210.6
    C.
    between 100 and 210
    D.
    none of these

  9. Pick out the wrong statement.

  10. A.
    With decrease in feed temperature, the number of plates required for binary distillation decreases for a given L/V ratio.
    B.
    The extraction per unit of total height for a short packed column is more effective than for a tall column, in case of liquid-liquid extraction.
    C.
    Natural draft cooling towers are made of ferro-concrete and its cross-section is wider at the bottom.
    D.
    Vanderwall adsorption is also called chemisorption.

  11. Batch tray dryers suffers from the disadvantage of

  12. A.
    high maintenance cost.
    B.
    non-uniform & low production rate.
    C.
    high labour cost & low heat economy.
    D.
    all 'a', 'b' & 'c'.

  13. In a moderately sized packed absorption tower, channeling (which is most severe with stacked packings) can be minimised by taking the ratio of tower diameter to packing diameter

  14. A.
    > 4 :1
    B.
    < 8 : 1
    C.
    > 8:1
    D.
    < 6:1

  15. __________ column is preferred to be used, when a high liquid hold up is required in a reactor for gas-liquid reaction.

  16. A.
    Packed
    B.
    Bubble
    C.
    Spray
    D.
    Tray

  17. The 'shanks system' of leaching (i.e., counter-current multiple contact leaching) is used for

  18. A.
    recovery of tannis from the tree barks and woods.
    B.
    leaching sodium nitrate from Chilean nitrate bearing rock.
    C.
    both (a) and (b).
    D.
    neither (a) nor (b).

  19. Penetration model (theory) for mass transfer was enunciated by

  20. A.
    Danckwerts
    B.
    Toor and Marchello
    C.
    Higbie
    D.
    Kissinevskii