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Chemical Engineering :: Mass Transfer

  1. In case of constant underflow extraction operation, the __________ at all solute concentration.

  2. A.
    solids are drained to the same extent
    B.
    ratio of the insoluble to solution is constant
    C.
    both(a) & (b)
    D.
    neither (a) nor (b)

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  3. In an absorption coloumn, the flooding velocity for random packing is __________ that for stacked/regular packing.

  4. A.
    greater than
    B.
    smaller than
    C.
    equal to
    D.
    either (a), or (b) ; depends on the type of packing

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  5. The relation among various mass transfer co-efficients (M.T.C) for ideal gases is given by (where, Kc & Km are M.T.C. for equimolar counter diffusion with concentration & mole fraction respectively as the driving force. and, Kp = M.T.C. for diffusion of a gas through a stagnant inert gas with pressure as driving force.)

  6. A.
    Kc = Kp = Km
    B.
    Kc = Kp/RT = Km . RT/P
    C.
    Kc = Kp . RT = Km . RT/p
    D.
    none of these

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  7. With increase in temperature, the leaching rate increases because of the

  8. A.
    increased diffusivity.
    B.
    decreased viscosity of liquid.
    C.
    both (a) and (b).
    D.
    neither (a) nor (b).

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  9. Leaching of uranium ore and gold ore is done in

  10. A.
    centrifugal extractor
    B.
    Pachuka tanks
    C.
    Bollman extractor
    D.
    none of these

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  11. Blowdown in a cooling tower

  12. A.
    means discarding a small fraction of circulating water to prevent and limit the concentration of salt and impurities.
    B.
    increases the scale forming tendencies of water.
    C.
    is undesirable.
    D.
    all (a), (b) & (c).

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  13. During constant rate period, the rate of drying decreases with the

  14. A.
    decrease in air temperature
    B.
    increase in air humidity
    C.
    both (a) and (b)
    D.
    neither (a) nor (b)

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  15. Antibiotics are best handled in a

  16. A.
    Podbielniak extractor.
    B.
    sieve tray contractor.
    C.
    rotating disc contactor.
    D.
    pulsed column extractor.

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  17. The fixed cost of a distillation column at minimum reflux ratio is

  18. A.
    minimum
    B.
    infinite
    C.
    optimum
    D.
    none of these

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  19. __________ extractor uses centrifugal force for separating the two phases.

  20. A.
    Treybal
    B.
    Schiebel
    C.
    Podbielniak
    D.
    None of these

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