A. Driving force for the vapour flow is the pressure drop
B. Liquids are not always at their bubble points
C. Pressure increases gradually from bottom to the top of the column
D. None of these
Related Mcqs:
- Minimum possible diameter of a packed column is decided mainly by the________________________?
A. Flooding
B. Gas viscosity
C. Liquid density
D. Liquid hold up - According to the Fenske equation, what will be the minimum number of plates required in a distillation column to separate an equimolar binary mixture of components A and B into an overhead fraction containing 99 mol% A and a bottom fraction containing 98 mol% B ? Assume that relative volatility (αAB = 2) does not change appreciably in the column ?
A. 5
B. 9
C. 12
D. 28 - Packed column distillation is limited to the column _____________ metres?
A. Height < 6
B. Diameter < 0.6
C. Both A. & B.
D. Neither A. nor B. - A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped). At the new steady state ?
A. Composition of vapors and that of liquid do not vary throughout the column
B. Reboiler load and condenser load are minimum
C. The top and bottom compositions are unchanged with and without total reflux
D. The top and bottom compositions correspond to the maximum enrichment available - In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the________________________?
A. Range is 15°F
B. Approach is 10°F
C. Both A. & B.
D. Neither A. nor B. - Inside the distillation columns, the ________________________?
A. Highest temperatures is near the feed plate
B. Driving force for the liquid flow is its weight
C. Vapors are not always at their dew points
D. All A., B. and C. - Polar organic compounds are normally used as separating agents for the azeotropic and extractive distillation. Which of the following is the most important factor to be considered for the choice of the separating agent for extractive distillation ?
A. Cost
B. Availability
C. Toxicity
D. Selectivity - The reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. The reflux ratio is____________________?
A. 2
B. 0.5
C. 50
D. 150 - For the same feed, feed quality and separation (in a distillation column), with the increase of total pressure, the number of ideal plates will_____________________?
A. Increase
B. Decrease
C. Remain same
D. Data insufficient, can’t be predicted - Small dia distillation column can be a _________________________?
A. Packed column
B. Sieve tray
C. Bubble cap
D. Any of these
