A. Vapour is enriched with low boilers
B. Vapour is enriched with high boilers
C. Liquid is stripped of high boilers
D. None of these
Related Mcqs:
- In McCabe-Thiele method of theoretical plate calculation for a distillation column, the operating lines of stripping and rectifying sections coincide with the diagonal at ________________ reflux ?
A. Total
B. Minimum
C. Operating
D. Maximum permissible - In stripping section of continuous distillation column, the_______________________?
A. Liquid is stripped of high boiler
B. Liquid is enriched with high boiler
C. Vapour is stripped of low boiler
D. None of these - If xD = overhead product molal composition and RD = reflux ratio, then slope and intercept of the operating line for rectifying section are respectively ?
A. [xD/(RD + 1)], [RD/(RD + 1)]
B. [RD/(RD + 1)], [xD/(xD + 1)]
C. [xD/(RD + 1)], [(RD + 1)/RD]
D. None of these - 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 At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped).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 - Use of packed towers for distillation is generally limited to the____________________?
A. Small sizes
B. Multi-component distillation
C. High pressure operation
D. Vacuum distillation - In continuous distillation, the internal reflux ratio (Ri) and the external reflux ratio (Re) are related as_____________________?
A. Ri = Re/(1 – Re)
B. Ri = (1 – Re)/Re
C. Ri = Re
D. Ri = Re/(1 + Re) - 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 - As the reflux ratio in a distillation column is increased from the minimum, the______________________?
A. Slope of the operating line in stripping section decreases
B. Number of plates decreases very slowly first and then more and more rapidly
C. Total cost first decreases and then increases
D. Liquid flow increases while the vapor flow decreases for a system