JD factor for mass transfer is a function of Reynolds number. Mass transfer by molecular diffusion from a single drop to surrounding still air is given by___________________?

Related Mcqs:

1. 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) ?

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

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

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

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 meters) corresponding to an operating line given by, y = 5x + 0.001 is ______________________?

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

4. The overall mass transfer co-efficient for the absorption of SO2 in air with dilute NaOH solution can be increased substantially by___________________?

   A. Increasing the gas film co-efficient
   B. Increasing the liquid film co-efficient
   C. Increasing the total pressure
   D. Decreasing the total pressure

5. For experimental determination of mass transfer co-efficient by wetted wall tower, the mass transfer area is___________________?

   A. Calculated
   B. Unknown
   C. Known
   D. Not required

6. The Reynolds number of the liquid was increased 100 fold for a laminar falling film used for gas-liquid contacting. Assuming penetrating theory is applicable, the fold increase in the mass transfer co-efficient (Kc) for the same system is_______________________?

   A. 100
   B. 10
   C. 5
   D. 1

7. For turbulent mass transfer in pipes, the Sherwood number depends on the Reynolds number as___________________?

   A. Re0.33
   B. Re0.53
   C. Re0.83
   D. Re

8. Ordinary diffusion process is also called ______________ diffusion?

   A. Pressure
   B. Thermal
   C. Concentration
   D. Forced

9. For the gas absorption, the height of a transfer unit, based on the gas phase is given by (G: superficial molar gas velocity, L: superficial molar liquid velocity, FG: mass transfer co-efficient, moles/m2, a: interfacial area per unit volume of tower) ?

   A. G/(FG . a)
   B. FG/(G . a)
   C. (G . a)/FG
   D. L/(FG . G)

10. In an interphase mass transfer process, the lesser the solubility of a given solute in a liquid, the higher are the chances that the transfer process will be_________________?

    A. Liquid phase resistance-controlled
    B. Gas phase resistance controlled
    C. Impossible
    D. Driven by a non-linear driving force