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

Related Mcqs:

1. 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___________________?

   A. Nsh = 2
   B. Nst = 2
   C. Nsc = 2
   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. 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

4. 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

5. A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids)) ?

   A. M(Xo – XF)
   B. M(Xo/XF)
   C. M ln(Xo/XF)
   D. MXo ln(Xo/XF)

6. A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids))_____________?

   A. M(Xo – XF)
   B. M(Xo/XF)
   C. M ln(Xo/XF)
   D. MXo ln(Xo/XF)

7. Mass transfer co-efficient ‘K’ according to penetration theory varies with mass diffusivity as____________________?

   A. D0.5
   B. D
   C. 1/D
   D. D1.5

8. Corresponding to Nusselt number in heat transfer, the dimensionless group in mass transfer is the ________________ number?

   A. Sherwood
   B. Schmidt
   C. Peclet
   D. Stanton

9. 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

10. Corresponding to Prandtl number in heat transfer, the dimensionless group in mass transfer is the _______________ number?

    A. Schmidt
    B. Sherwood
    C. Peclet
    D. Stanton