The Knudsen diffusivity is proportional to (where, T = absolute temperature) ______________________?

Related Mcqs:

1. The Knudsen diffusivity is dependent on the ______________________?

   A. Molecular velocity only
   B. Pore radius of the catalyst only
   C. Molecular mean free path only
   D. Molecular velocity and pore radius of the catalyst

2. 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

3. If the solubilities of different components (in a liquid-liquid extraction system) increase with rise in temperature, then the temperature above which they dissolve completely is known as the critical solution temperature (CST or consolute temperature). If solubilities increase with decrease in temperature, then CST is the temperature below which they dissolve completely. If a binary system has no critical solution temperature, it implies that___________________?

   A. The system comprises of partially miscible liquids
   B. The system comprises of miscible liquids
   C. The system comprises of an azeotrope
   D. On heating, a vapor phase will appear; while on cooling, a solid phase will appear

4. In case of liquids, the binary diffusivity is proportional to (where, T = temperature) _____________________?

   A. T
   B. √T
   C. T2
   D. 1/T

5. 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

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

   A. 0
   B. 1
   C. 1

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

   A. Increases
   B. Decreases
   C. Remain same
   D. Either A. or B.; depends on the gas

8. 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

9. In case of gases, the binary diffusivity is proportional to (where, P = pressure) ?

   A. P
   B. 1/P
   C. 1/√P
   D. √P

10. The diffusivity D. in a binary gas mixture is related to the temperature (T) as________________________?

    A. D ∝ T
    B. D ∝ T0.5
    C. D ∝ T1.5
    D. D ∝ T2