Question: Back-trapping in a distillation column [A]. increases tray efficiency. [B]. decreases tray efficiency. [C]. reduces pressure drop. [D]. is desirable, as it provides improved vapour-liquid contact. Answer: Option B Explanation: No answer description available for this question.

Question: If the path of liquid across the plate is very long as in case of large diameter tower, Murphree efficiency can be __________ percent. [A]. 100 [B]. > 100 [C]. < 100 [D]. none of these Answer: Option B…

Question: Overall efficiency of the distillation column is [A]. the ratio of number of ideal plates to actual plates. [B]. the ratio of number of actual plates to ideal plates. [C]. same as the Murphree efficiency. [D]. always more than…

Question: Absorption factor method is used to calculate the number of ideal stages, when [A]. operating line lies above the equilibrium line. [B]. operating line lies below the equilibrium line. [C]. both operating and equilibrium lines are parallel. [D]. pressure…

Question: At equilibrium the concentration of water in vapour phase (C*)in kg/m3 of air space and the amount of water (m) adsorbed per kg of dry silica gel are related by, C* = 0.0667m. To maintain dry conditions in a…

Question: As the reflux ratio decreases, the [A]. separation becomes more efficient. [B]. number of plates increases. [C]. column diameter increases. [D]. none of these. Answer: Option B Explanation: No answer description available for this question.

Question: A 25 cm x 25 cm x 1 cm flat sheet weighing 1.2 kg initially was dried from both sides under constant drying rate conditions. It took 1500 seconds for the weight of the sheet to reduce to 1.05…

Question: An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler…

Question: For water-ethanol system, the minimum reflux ratio [A]. is computed from the slope of the upper operating line that is tangent to the equilibrium curve. [B]. is computed from the intercept of the operating line. [C]. cannot be computed.…

Question: 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 At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is…