Related Mcqs:

1. An alkaline solution is used to reduce the concentration of carbon dioxide in a stream from 10% to 0.1% by absorption with irreversible chemical reaction. The overall number of transfer units based on gas phase is ?

   A. 9.21
   B. 4.605
   C. 100
   D. 0.001

2. In the absorption of ammonia in water, the main resistance to absorption is by the _________________ phase?

   A. Liquid
   B. Gas
   C. Both A. & B.
   D. Neither A. nor B.

3. The individual mass transfer co-efficients (moles/m2s) for absorption of a solute from a gas mixture into a liquid solvent are, KL = 4.5 and KG = 1.5. The slope of the equilibrium line is 3. Which of the following resistance (s) is (are) controlling ?

   A. Liquid side
   B. Gas side
   C. Interfacial
   D. Both liquid and gas side

4. The individual mass transfer co-efficients (moles/m2s) for absorption of a solute from a gas mixture into a liquid solvent are, KL = 4.5 and KG = 1.5. The slope of the equilibrium line is 3. Which of the following resistance (s) is (are) controlling ?

   A. Liquid side
   B. Gas side
   C. Interfacial
   D. Both liquid and gas side

5. 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)

6. 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

7. 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

8. 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

9. 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)

10. 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)