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 : 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 : The value of NA/(NA + NB), for steady state equimolal counter diffusion of two gases 'A' and 'B' is (A) 1 (B) ∞ (C) 0.5
Last Answer : (B) ∞
Description : Binary distillation involves the mass transfer by __________ at the gasliquid interface. (A) Unidirectional diffusion from liquid to gas phase (B) Unidirectional diffusion from gas to liquid phase (C) Either 'a' or 'b' (D) A counter diffusion at an almost equal molar rate
Last Answer : (D) A counter diffusion at an almost equal molar rate
Description : Extraction of coffee from its seed is done by (A) Liquid-liquid extraction (B) Leaching (C) Extractive distillation (D) Steam distillation
Last Answer : (B) Leaching
Description : Pick out the wrong statement. (A) With decrease in feed temperature, the number of plates required for binary distillation decreases for a given L/V' ratio (B) The extraction per unit ... and its crosssection is wider at the bottom (D) Vander wall adsorption is also called chemisorption
Last Answer : (D) Vander wall adsorption is also called chemisorption
Description : Tea percolation employs (A) Liquid-liquid extraction (B) Leaching (C) Absorption (D) None of these
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 : Essential oils are usually obtained using (A) Steam distillation (B) Extractive distillation (C) Solvent extraction (D) Leaching
Last Answer : (D) Leaching
Description : Which of the following unit operations makes use of Thiele-Geddes equation? (A) Liquid-liquid extraction (B) Solid-liquid extraction (C) Multi-component absorption with chemical reaction (D) Multi-component distillation
Last Answer : (D) Multi-component distillation
Description : Heat sensitive materials with very high latent heat of vaporisation may be economically separated using (A) Liquid extraction (B) Distillation (C) Evaporation (D) Absorption
Last Answer : (A) Liquid extraction
Description : The recovery of penicillin from the acidified fermentation broth is done by (A) Distillation (B) Evaporation (C) Absorption (D) Liquid extraction
Last Answer : (D) Liquid extraction
Description : Separation of the isotopes of helium for scientific investigations is done by (A) Reverse osmosis (B) Thermal diffusion (C) Leaching (D) Solvent extraction
Last Answer : (B) Thermal diffusion
Description : Bollman extractor (A) Is a static bed leaching equipment (B) Is used for extraction of oil from oilseed (C) Is a centrifugal extractor (D) Employs only counter-current extraction
Last Answer : (B) Is used for extraction of oil from oilseed
Description : Langmuir equation is associated with (A) Leaching (B) Adsorption (C) Steam distillation (D) Multi-component absorption
Last Answer : (B) Adsorption
Description : For a ternary mixture, in which equilateral triangular co-ordinate is used in leaching and extraction, a __________ of the equilateral triangular co-ordinates. (A) Binary mixture is ... Ternary mixture is represented by the sides (D) Pure component is represented by the apex
Last Answer : (D) Pure component is represented by the apex
Description : Ion exchange process is similar to (A) Absorption (B) Adsorption (C) Extraction (D) Leaching
Description : The equation, NA = (DAB . Pt /RTZ . PBM) (PA1 - PA2 ) is for (A) Fick's second law of diffusion (B) Steady state diffusion for stagnant case (C) Liquid M.T.C. by Higbie penetration theory (D) None of these
Last Answer : (B) Steady state diffusion for stagnant case
Description : Pick out the wrong statement. (A) The controlling resistance in case of heating of air by condensing steam is in the air film (B) The log mean temperature difference (LMTD) for ... a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature
Last Answer : (C) In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs
Description : The rate of solid-liquid extraction is limited by the (A) Phase change of the solute as it dissolves in the solvent (B) Diffusion of the solute through the solvent in the pores to the outside of the particle (C) ... contact with the particle to the main bulk of the solution (D) All 'a', 'b' & 'c'
Last Answer : (D) All 'a', 'b' & 'c'
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 : 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 : Stage efficiency in a leaching process depends on the (A) Time of contact between the solid and the solution (B) Rate of diffusion of the solute through the solid and into the liquid (C) Both (A) and (B) (D) Vapour pressure of the solution
Last Answer : (C) Both (A) and (B)
Description : In case of liquid-liquid binary diffusion, diffusivity of one constituent into another is not dependent on the (A) Temperature and pressure (B) Concentration (C) Nature of the constituents (D) None of these
Last Answer : (D) None of these
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 : Acetic acid will be most economically separated from a dilute solution of acetic acid in water by (A) Solvent extraction (B) Continuous distillation (C) Evaporation (D) Absorption
Last Answer : (A) Solvent extraction
Description : Pick out the wrong statement. (A) The Reynolds analogy for mass transfer is given by Lewis relation and is applicable, when Schmidt number is one (B) Sherwood number for flow in pipes can be expressed ... flux of a component A in binary mixture of A and B is given by - Dab'.dCA/dz
Last Answer : (C) According to film theory for equimolar counter diffusion, the mass transfer coefficient is given by DAB(B)P - 3, Q - 2
Description : Pick out the wrong statement. (A) When the concentration difference for the mass transfer becomes zero at the bottom of the gas absorption tower, then the upper end of the operating line touches the ... fixed gas flow rate, the slope of the operating line decreases, in case of gas absorption process
Last Answer : (C) The operating line lies above the equilibrium curve in case of a gas desorber
Description : For which of the following unit operations, Lewis number is ofsignificance? (A) Adsorption (B) Binary distillation (C) Gas absorption (D) Humidification
Last Answer : (D) Humidification
Description : The Hatta number is important in (A) Multi-component distillation (B) Binary distillation (C) Gas absorption without chemical reaction (D) Gas absorption with chemical reaction
Last Answer : (D) Gas absorption with chemical reaction
Description : 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 ... and without total reflux (D) The top and bottom compositions correspond to the maximum enrichment available
Last Answer : (D) The top and bottom compositions correspond to the maximum enrichment available
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 solvent used in liquid extraction should not have high latent heat of vaporisation, because (A) The pressure drop and hence the pumping cost will be very high (B) It cannot ... by distillation may be prohibitively high (D) It will decompose while recovering by distillation
Last Answer : (C) Its recovery cost by distillation may be prohibitively high
Description : Black liquor is converted into white liquor by (A) Evaporation and burning the concentrate followed by causticisation of products (B) Multi-effect evaporation only (C) Selective liquid extraction (D) Extractive distillation
Last Answer : (A) Evaporation and burning the concentrate followed by causticisation of products
Description : Glycerine is recovered from lye by (A) Evaporation followed by vacuum distillation (B) Liquid extraction technique (C) Extractive distillation technique (D) None of these
Last Answer : (A) Evaporation followed by vacuum distillation
Description : The most important application of distribution law is in (A) Evaporation (B) Liquid extraction (C) Drying (D) Distillation
Last Answer : (B) Liquid extraction
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 : 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
Description : When acetone is added in a two layer mixture of methyl isobutyl ketone and water at 30°C, the acetone distributes between the two layers and the composition of the layer follows two solubility curves. For this system ... at the concentration of the plait point (D) All (A), (B) and (C
Last Answer : (D) All (A), (B) and (C
Description : In case of binary distillation, increasing the reflux ratio above optimum does not result in the increase of (A) Area between operating line and 45° diagonal x-y diagram (B) Condenser and reboiler surfaces (C) Tower cross-section (D) None of these
Last Answer : (A) Area between operating line and 45° diagonal x-y diagram
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 : ADDUCTS' and 'CLATHRATES' are used in case of (A) Extractive distillation (B) Crystallisation (C) Absorption (D) None of these
Last Answer : (B) Crystallisation
Description : Degree of freedom for leaching and solvent extraction process is (A) 0 (B) 1 (C) 2 (D) 3
Last Answer : (D) 3
Description : With increase in temperature, the rate of extraction in leaching (solidliquid extraction system). (A) Increases (B) Decreases (C) Remain unaffected (D) Increases Linearly
Last Answer : (A) Increases
Description : Which of the following solvents is used for the extraction of H3PO4 from CaCl2 solution during manufacture of ortho-phosphoric acid by wet process employing hydrochloric acid leaching? (A) Isopropyl alcohol (B) Butyl alcohol (C) Toluene (D) Hexane
Last Answer : (B) Butyl alcohol
Description : Separation of two or more components of a liquid solution cannot beachieved by (A) Fractional crystallisation (B) Liquid extraction (C) Absorption (D) Evaporation
Last Answer : (C) Absorption
Description : Which one of the following devices is not used for both the absorption as well as the liquid-liquid extraction processes? (A) Packed towers (B) Plate towers (C) Spray towers (D) Wetted wall columns
Last Answer : (D) Wetted wall columns
Description : The 'shanks system' of leaching (i.e., counter-current multiple contact leaching) is used for (A) Recovery of tannis from the tree barks and woods (B) Leaching sodium nitrate from Chilean nitrate bearing rock (C) Both (A) and (B) (D) Neither (A) nor (B)
Description : With increase in the liquid flow rate at a fixed gas velocity in a randomly packed counter current gas-liquid absorption column, the gas pressure drop (A) Decreases (B) Remains unchanged (C) Increases (D) Decreases exponentially
Last Answer : (C) Increases
Description : Intestinal absorption of calcium occurs by (A) Active takeup (B) Simple diffusion (C) Facilitated diffusion (D) Endocytosis
Last Answer : Answer : A