Description : The expression, y(1 - x)/x(1 - y) is for (A) Absorption factor (B) Relative volatility (C) Selectivity (D) Murphree efficiency
Last Answer : (B) Relative volatility
Description : Separation of two volatile liquids by distillation makes use of their (A) Selectivity (B) Relative volatility (C) Solubility (D) Density difference
Description : _________ is defined as the geometric mean of the relative rejections and the relative recoveries of two minerals. (A) Separation efficiency (B) Selectivity index (C) Concentration ratio (D) None of these
Last Answer : (B) Selectivity index
Description : Separation of a mixture of two gases by absorption in the liquid solvent depends upon the difference in their (A) Viscosity (B) Density (C) Solubility (D) Relative volatility
Last Answer : (C) Solubility
Description : In extractive distillation, solvent is (A) Added to alter the relative volatility of the mixture (B) Of high volatility (C) Present in overhead stream (D) Of high viscosity to give high tray efficiency
Last Answer : (A) Added to alter the relative volatility of the mixture
Description : Entrainer used in Azeotropic distillation should (A) Form a low boiling azeotrope with one of the constituents of the mixture (B) Form a new azeotrope of low relative volatility with one of the ... (C) Have high latent heat of vaporisation (D) Have high viscosity to provide high tray efficiency
Last Answer : (A) Form a low boiling azeotrope with one of the constituents of the mixture
Description : The slope of 9-line is determined by the (A) Reflux ratio (B) Plate efficiency to be achieved (C) Thermal condition of the feed (D) Relative volatility
Last Answer : (C) Thermal condition of the feed
Description : Reciprocal of sphericity is termed as the (A) Specific surface ratio (B) Shape factor (C) Sauter diameter (D) Surface area per unit mass
Last Answer : (B) Shape factor
Description : 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 the point efficiency
Last Answer : (A) The ratio of number of ideal plates to actual plates
Description : When the liquid over a plate is of uniform concentration, then (A) Murphree efficiency > point efficiency (B) Murphree efficiency < point efficiency (C) Murphree efficiency = point efficiency (D) Murphree efficiency ≠ point efficiency
Last Answer : (C) Murphree efficiency = point efficiency
Description : Pick out the wrong statement. (A) In the McCabe-Thiele diagram for binary distillation, vertical feed line represents saturated liquid feed and horizontal feed line represents saturated vapour feed (B) In ... layers over a flat plate are of equal thickness, if Schmidt number is equal to unity
Last Answer : (C) For Laminar flow over a plate of length L, the local mass transfer coefficient at a distance L from the leading edge is 1.5 × 10 -2m/s. Then the average mass transfer co-efficient for the plate is 2 × 10 -2m/s
Description : If the overall efficiency and Murphree plate efficiency are equal, then both the equilibrium and operating lines are: (A) Straight (B) Parallel (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : 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
Last Answer : (B) > 100
Description : Flooding in a distillation column is detected by a sharp (A) Increase in Murphree plate efficiency (B) Decrease in pressure drop (C) Decrease in liquid hold up in the column (D) Increase in pressure drop
Last Answer : (D) Increase in pressure drop
Description : The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (A) Plug
Description : The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (B) Perfectly mixed
Description : Pick out the wrong statement. (A) In solvent extraction, the distribution co-efficient should be as large as possible for solvent economy (B) With increase in pressure, the solubility of ... in distillation column (D) The capacity of a distillation column is maximum at total reflux
Last Answer : (D) The capacity of a distillation column is maximum at total reflux
Description : The phenomenon occuring during pumping of a liquid solution containing dissolved gases, which may come out of the solution giving rise to gas pockets, is termed as (A) Evaporation (B) Cavitation (C) Sublimation (D) Stripping
Last Answer : (B) Cavitation
Description : In case of absorption & stripping, the interface of the liquid & gas phases are present in equilibrium, when the diffusional resistance of __________ is zero. (A) Interface (B) Gas phase (C) Liquid phase (D) All 'a', 'b' & 'c'
Last Answer : (A) Interface
Description : Pick out the wrong statement (A) Co-current absorbers are usually used, when the gas to be dissolved in the liquid is a pure substance (B) In case of gas absorption, HETP is ... reaction (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process
Last Answer : (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process
Description : Pick out the correct statement. (A) The slope of the stripping line is always less than unity (B) For a given separation in a binary distillation column, with increase in reflux ratio ( ... (D) Kremser-Brown-Souder's equation is used to calculate the efficiency of a plate tower
Last Answer : C) In Ponchon-Savarit method of no. of theoretical plate determination, the stripping and rectifying operating lines are vertical at total reflux
Description : In which of the following unit operations, the selectivity is an important parameter? (A) Distillation (B) Solvent extraction (C) Absorption (D) None of these
Last Answer : (B) Solvent extraction
Description : For a binary mixture with low relative volatility, continuous rectification to get pure products will require (A) Low reflux ratio (B) Less number of trays (C) Small cross-section column (D) High reflux ratio
Last Answer : (D) High reflux ratio
Description : Solvent used in extractive distillation (A) Changes the relative volatility of the original components (B) Should be of high volatility (C) Should form azeotropes with the original components (D) All (A), (B) and (C)
Last Answer : (A) Changes the relative volatility of the original components
Description : Pick out the wrong statement. (A) The mole fraction of solute is directly proportional to the molality of a 'dilute' solution (B) For a non-reacting binary mixture of ideal gases, the partial ... at all temperature (D) The relative volatility of a binary mixture at the Azeotropic composition is 1
Last Answer : (C) Azeotropes obey Raoult's law at all temperature
Description : Solvent used in extractive distillation (A) Is of low volatility (B) Forms a low boiling azeotrope (C) Forms a high boiling azeotrope (D) Does not alter the relative volatility of the original components
Last Answer : (B) Forms a low boiling azeotrope
Description : Fenske-Underwood equation used for calculating the minimum number of theoretical plates in distillation column is valid for (A) Constant molal overflow (B) Total reflux (C) Constant relative volatility (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : The-relative volatility for separation of a non-ideal binary mixture by distillation should be (A) 0 (B) 1 (C) > 1 (D) < 1
Last Answer : (C) > 1
Description : If the amount of the steam used in steam distillation is increased, the temperature of distillation (A) Increases (B) Decreases (C) Remains unchanged (D) Depends on relative volatility
Last Answer : (B) Decreases
Description : With increase in pressure, the relative volatility for a binary system (A) Increases (B) Decreases (C) Remains same
Description : In a binary system, separation is very efficient, when the relative volatility is (A) 1 (B) > 1 (C) < 1 (D) 0.5
Last Answer : (B) > 1
Description : Relative volatility does not change appreciably with the change in (A) Temperature (B) Vapour pressure of either component (C) Total pressure (D) None of these
Last Answer : (A) Temperature
Description : Fenske equation for determining the minimum number of theoretical stages in distillation column holds good, when the (A) Relative volatility is reasonably constant (B) Mixture (to be separated) ... (to be separated) shows positive deviation from ideality (D) Multi-component distillation is involved
Last Answer : (A) Relative volatility is reasonably constant
Description : When the liquid phase and vapour phase of a binary system obeys Raoult's and Dalton's law respectively, the relative volatility is the ratio of (A) Vapour pressure of component A to that of ... to the partial pressure of A (D) Partial pressure of component A to the total pressure
Last Answer : (A) Vapour pressure of component A to that of component B
Description : In case of __________ distillation, a solvent is added to alter the relative volatility of the mixture to be separated. (A) Molecular (B) Azeotropic (C) Extractive
Last Answer : (C) Extractive
Description : Pick out the wrong statement. (A) Constant pressure distillation cannot separate an Azeotropic mixture (B) Relative volatility of a binary mixture changes appreciably with the minor change in ... unity (D) Flash distillation is practised on wide spread scale in petroleum refinery
Last Answer : (B) Relative volatility of a binary mixture changes appreciably with the minor change in temperature
Description : High pressure at the bottom of a distillation tower handling heat sensitive materials results in (A) Thermal decomposition of bottoms (B) Increased relative volatility (C) Erosion of the tower (D) Very efficient operation
Last Answer : (A) Thermal decomposition of bottoms
Description : For a binary mixture with low relative volatility, (A) Use steam distillation (B) Use molecular distillation (C) Use high pressure distillation (D) An azeotrope may be formed during distillation
Last Answer : (D) An azeotrope may be formed during distillation
Description : Relative volatility varies with the concentration of component for an ideal solution. The relative volatility of a binary mixture may be defined as the ratio of vapor pressure of component 'A' to that of ... law (D) Vapor phase obeys Dalton's law and liquid phase obeys Raoult's law
Last Answer : (D) Vapor phase obeys Dalton's law and liquid phase obeys Raoult's law
Description : The relative volatility of a binary mixture at the Azeotropic composition is (A) 1 (B) > 1 (C) 0 (D) ∞
Last Answer : (D) ∞
Description : The relative volatility of a binary mixture at constant temperature __________ the total pressure. (A) Decreases with increase in (B) Increases with increase in (C) Is independent of (D) None of these
Last Answer : (A) Decreases with increase in
Description : 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 ... in the column. (A) 5 (B) 9 (C) 12 (D) 28
Last Answer : (C) 12
Description : Fugacity is a measure of the (A) Escaping tendencies of the same substance in different phases of a system (B) Relative volatility of a mixture of two miscible liquids (C) Behaviour of ideal gases (D) None of these
Last Answer : (A) Escaping tendencies of the same substance in different phases of a system
Description : The ratio of moles of a reactant converted into the desired product to that converted into unwanted product is called (A) Operational yield (B) Relative yield (C) Selectivity (D) None of these
Last Answer : (C) Selectivity
Description : Smoke volatility index is equal to smoke point plus (A) 0.42 × (% distilled at 204°C) (B) 5 mm (C) 0.84 × (% distilled at 204°C) (D) 10 mm approximately
Last Answer : (A) 0.42 × (% distilled at 204°C)
Description : A good lubricant should have high (A) Viscosity index (B) Volatility (C) Pour point (D) None of these
Last Answer : (A) Viscosity index
Description : What is the selectivity index, if the grade of tailings & concentrate is the same? (A) 0 (B) ∞ (C) 1 (D) 0.5
Last Answer : (C) 1
Description : . Which of the following physiological proc ess influence the herbicide selectivity? a). Absorption and translocation b). Deactivation c). Phytotoxicity d). All of these
Last Answer : d). All of these
Description : In gas-liquid contact operation, the number of ideal stages, N = (xa - xb )/(xb - x *b ). This is true when the stripping factor 'S' is (A) S > 1 (B) S < 1 (C) S = 1 (D) S = ∞
Last Answer : (A) S > 1
Description : 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 ... ? (A) Cost (B) Availability (C) Toxicity (D) Selectivity
Last Answer : (D) Selectivity