Transport Phenomena in Bioprocesses Mid - II, November - 2014

1._________ Transfer processes are known as Transport operations.
  • Diffusional
  • liquid-liquid
  • mass transfer with phase change
  • all of the above
Answer: D
2.Fick’s law of diffusion __________
  • JA = NA/A
  • JA = -DABdcA/dy
  • both
  • none
Answer: C
3.Schmidt number defined as ___________
  • v/DAB
  • /q DAB
  • both
  • all of the above
Answer: D
4.The mixing length theory satisfies the Rhenolds analogy Pr = SC =
  • 1
  • 2
  • 3
  • 4
Answer: A
5.In penetration theory mass transfer coefficient is directly propositional to _______
  • DAB 0.5
  • DAB
  • DAB 1.5
  • DAB 2
Answer: A
6.The boundary layer may be characterised by ______________
  • Laminar flow
  • turbulent flow
  • transition flow
  • All of the above
Answer: A
7.Mass transfer resistance defined as R = _________
  • 1/kl
  • kl
  • k/l
  • 1/kla
Answer: D
8.Measurement of KLA by __________
  • Static method
  • Dynamic method
  • Sulphite oxidation method
  • All of the above
Answer: D
9.When the temperature is above 400c mass transfer rate _________
  • Decreases
  • Increases
  • both
  • All of the above
Answer: A
10.___________ are the factors affecting mass transfer rate.
  • Bubble size
  • gas holds up
  • gas velocity
  • All of the above
Answer: D
11.Sherwood number defined as _________
Answer: KLD/DAB
12.In molecular diffusion mass transfer takes place purely by ___________
Answer: Concentration gradient
13.If the solute in the lower concentration region is constantly depleted by consumption by__________
Answer: Chemical reaction
14.Fick’s second law of diffusion ________________
Answer: Dca/dt = Dab d2ca/dx2
15.Renewal theory mass transfer coefficient is directly propositional to _________
Answer: Dab 0.5
16.Distribution coefficient m = _________
Answer: C1/C2
17.Mass transfer occurs between the phases _________
Answer: Liquid-solid, liquid –liquid, gas-liquid
18.________ method is simple and most reliable and can also be used when the fermenter is in operation.
Answer: Dynamic
19._________ are the classification of agitators.
Answer: Propellers, turbine, paddle
20.K l values decreases with decreasing bubble diameter below ________ mm
Answer: 2