Liquid diffusivity is of the order of _______________ cm2 /second?

Related Mcqs:

1. The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = _________________?

   A. 1
   B. 0.5
   C. 10
   D. 0

2. Gaseous diffusivity at atmospheric pressure is of the order of _____________________ cm2/second?

   A. 1
   B. 1 to 5
   C. 5 to 10
   D. > 10

3. In case of liquid-liquid binary diffusion, diffusivity of one constituent into another is not dependent on the__________________?

   A. Temperature and pressure
   B. Concentration
   C. Nature of the constituents
   D. None of these

4. The diffusivity, DAB (for component A diffusing in B) is equal to the diffusivity DBA (for component B diffusing in A) for a binary mixture of________________?

   A. Newtonian liquids
   B. Non-Newtonian liquids
   C. Ideal gases
   D. Real gases

5. If mass diffusivity in a mixture is equal to the thermal diffusivity, then the Lewis number is____________________

   A. 0
   B. 1
   C. 1

6. Experiments were conducted to determine the flux of a species A in a stagnant medium across a gas-liquid interface. The overall mass transfer co-efficient based on the liquid side for dilute systems for the above was estimated to be 4 × 10-3 kg mole/m2.s. The equilibrium data for the system is given as y = 2x. The flux across the interface (in kg mole/m2 .s) for bulk concentrations of A in gas phase and liquid phase as y = 0.4 and x = 0.01 respectively is _________________________?

   A. 5.6 × 10-4
   B. 8.5 × 10-4
   C. 5.6 × 10-3
   D. 8.5 × 10-3

7. The mass transfer co-efficient for a solid sphere of radius ‘a’ dissolving in a large volume of quiescent liquid, in which „D’ is the diffusivity of solute, is _____________________?

   A. D/a
   B. D/2a
   C. Proportional to √D
   D. Dependent on the Reynolds number

8. The solvent used in liquid-liquid extraction should have _______________ less than one?

   A. Selectivity
   B. Distribution co-efficient
   C. Both A. and B.
   D. Neither A. nor B.

9. Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is _______________ the liquid head available in the downcomer?

   A. Less than
   B. More than
   C. Same as
   D. Very much less

10. In liquid-liquid extraction, the number of phases at plait point is __________________?

    A. 1
    B. 2
    C. 3
    D. 4