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
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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : Components, having widely different boiling point in a binary mixture, can be separated using __________ distillation. (A) Molecular (B) Extractive (C) Steam (D) Simple
Last Answer : (D) Simple
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 : 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 : 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 : 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 : 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 : Pick out the correct statement. (A) Ponchan-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of ... Flash distillation is suitable for separating components which have very close boiling temperature
Last Answer : (A) Ponchan-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of nonideal binary system by distillation
Description : The relative volatility of a binary mixture at the Azeotropic composition is (A) 1 (B) > 1 (C) 0 (D) ∞
Last Answer : (D) ∞
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 : Flash distillation is suitable for separating the constituents of a binary system, which (A) Form minimum boiling azeotrope (B) Have very wide boiling points (C) Have very close boiling points (D) Form constant boiling azeotrope
Last Answer : (B) Have very wide boiling points
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 : With increase in pressure, the relative volatility for a binary system (A) Increases (B) Decreases (C) Remains same
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 : Steam distillation is not recommended to be used, if the (A) Azeotropic mixture is to be separated and the final product is miscible with water (B) Liquids decompose, if ... unstable or has the tendency to react with other components associated with it, at the boiling temperature
Last Answer : (A) Azeotropic mixture is to be separated and the final product is miscible with water
Description : Separation of two volatile liquids by distillation makes use of their (A) Selectivity (B) Relative volatility (C) Solubility (D) Density difference
Last Answer : (B) Relative volatility
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 : Distillation at reduced pressure is used for liquids which (a) Have high boiling points (b) Have low boiling points (c) Have high volatility (d) Decompose before their boiling points
Last Answer : Ans:(d)
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 : 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 : 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 : Pick out the correct statement. (A) Higher hold up of the solid in the rotary dryer results in better exposure of the solids to the gas (B) The 'Hatta number' is ... reflux in case of distillation operation requires infinite number of plates for a binary system separation
Last Answer : (C) For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is linear in the case of steady state equimolal counter-diffusion
Description : For a binary mixture distillation process, the degree of freedom is 2. However, if the pressure is fixed in this process, the number of independent variables in this process will be (A) 1 (B) 0 (C) 2 (D) 3
Last Answer : (A) 1
Description : Pick out the wrong statement. Generally for physical adsorption, a gas of (A) Higher molecular weight is adsorbed in preference to a gas of low molecular weight (B) High critical temperature ... volatility is adsorbed in preference to a gas of high volatility (D) None of these
Last Answer : (D) None of these
Description : In distillation column design, the McCabe-Thiele procedure is inadequate and a Ponchan-Savarit procedure is needed, when (A) Saturated feed is not used (B) An azeotrope forms (C) The latent ... vaporisation of the more and less volatile components are greatly different (D) A total condenser is used
Last Answer : (D) A total condenser is used
Description : Flash distillation is suitable for the separation of components (A) Having very close boiling points (B) Which form maximum boiling azeotrope (C) Having very wide boiling points (D) Which form minimum boiling azeotrope
Last Answer : (C) Having very wide boiling points
Description : Molecular distillation is (A) High temperature distillation (B) For heat-sensitive materials (C) Very low pressure distillation (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation. (A) Continuous (B) Steam (C) Azeotropic (D) None of these
Last Answer : (B) Steam
Description : If the solubilities of different components (in a liquid-liquid extraction system) increase with rise in temperature, then the temperature above which they dissolve completely is known as the critical solution ... On heating, a vapor phase will appear; while on cooling, a solid phase will appear
Last Answer : (D) On heating, a vapor phase will appear; while on cooling, a solid phase will appear
Description : Which of the following binary systems is an example of a maximum boiling azeotrope? (A) Water-hydrochloric acid (B) Acetone-carbon disulphide (C) Water-ethyl alcohol (D) n-heptane-n-octane
Last Answer : (A) Water-hydrochloric acid
Description : Pick out the wrong statement: (A) Reboiler is not used in open steam distillation (B) The separation of solutes of different molecular sizes in a liquid solution by use of a ... is used for calculating theoretical number of plates in a distillation column at normal operating reflux condition
Last Answer : (D) Fenske-Underwood equation is used for calculating theoretical number of plates in a distillation column at normal operating reflux condition
Description : Alcohol is dehydrated using __________ distillation. (A) Extractive (B) Azeotropic (C) Steam (D) Molecular
Last Answer : (B) Azeotropic
Description : Rose oil is extracted from rose leaves using __________ distillation. (A) High pressure (B) Low pressure (C) Extractive (D) Steam
Last Answer : (D) Steam
Description : A binary mixture of benzene and cyclohexane is separated by (A) Flash vaporisation (B) Extractive distillation (C) Solvent extraction (D) Ordinary distillation
Last Answer : (B) Extractive distillation
Description : Steady state equimolal counter diffusion is encountered in (A) Separation of a binary mixture by distillation (B) Absorption of NH3 from air by water (C) All liquid-liquid diffusion systems (D) All liquid-solid diffusion systems
Last Answer : (A) Separation of a binary mixture by distillation
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 : A liquid mixture contains 30% o-xylene, 60% p-xylene and 10%. mxylene (all percentages in w/w). Which of the following statements would be true in respect of this mixture? (A) The mixture exhibits ... : o-xylene 30, p-xylene 60 and m-xyoene 10 (D) The mixture contain optical isomers
Last Answer : (A) The mixture exhibits an azeotrope at 101.3 kPa
Description : While separating a mixture of ortho and para-nitro phenols by steam distillation, name the isomer which will be steam volatile. Give reasons.
Last Answer : In o-nitrophenol, there is intramolecular hydrogen bonding as follows : In p-nitrophenol, there is intramolecular hydrogen bonding as follows : Due to intermolecular H ... -nitrophenol. Hence o-nitraphenol due to its lower b. p. is steam volatile while pnitrophenol is not.
Description : Pick out the wrong statement. (A) Critical moisture content is not a property of the material itself (B) A sharp increase in pressure drop gives an indication of the flooding in a ... unity (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum
Last Answer : (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum
Description : The reciprocal of stripping factor is termed as (A) Selectivity index (B) Relative volatility (C) Absorption factor (D) Murphree efficiency
Last Answer : (C) Absorption factor
Description : The expression, y(1 - x)/x(1 - y) is for (A) Absorption factor (B) Relative volatility (C) Selectivity (D) Murphree efficiency
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 : Gibbs-Duhem equation (A) States that n1dμ1 + n2dμ2 + ....njdμj = 0, for a system of definite composition at constant temperature and pressure (B) Applies only to binary systems (C) Finds no application in gas-liquid equilibria involved in distillation (D) None of these
Last Answer : (A) States that n1dμ1 + n2dμ2 + ....njdμj = 0, for a system of definite composition at constant temperature and pressure