Fractional solvent extraction
(A) Employs only one solvent
(B) Employs two solvents
(C) Results in low interfacial tension
(D) None of these
Description : In a liquid-liquid extraction, 10 kg of a solution containing 2 kg of solute C and 8 kg of solvent A is brought into contact with 10 kg of solvent B. Solvent A and B are completely immiscible in each other whereas ... (C) Less than 1 kg of C is transferred to B (D) No amount of C is transferred to B
Last Answer : (A) The entire amount of C is transferred to solvent B
Description : The interfacial area per unit volume of dispersion, in a gas-liquid contactor, for fractional hold up of gas = 0.1 and gas bubble diameter = 0.5 mm is given by (in m2 /m3 ) (A) 500 (B) 1200 (C) 900 (D) 800
Last Answer : (A) 500
Description : Pick out the wrong statement. (A) Mechanical agitation is required, if the system has low interfacial tension (B) Sieve tray towers are generally used for systems having low ... Prandtl analogy for heat and mass transfer considers the transfer through both laminar and turbulent layers
Last Answer : (A) Mechanical agitation is required, if the system has low interfacial tension
Description : Pick out the wrong statement regarding the solubility characteristics of high polymers. (A) Greater the degree of cross-linking in the polymer, lesser is its solubility (B) Polymers having more ... of the solvent (D) High molecular weight polymers on dissolving gives solution of very low viscosity
Last Answer : (D) High molecular weight polymers on dissolving gives solution of very low viscosity
Description : The individual mass transfer co-efficients (moles/m2s) for absorption of a solute from a gas mixture into a liquid solvent are, KL = 4.5 and KG = 1.5. The slope of the equilibrium line is 3. Which of ... A) Liquid side (B) Gas side (C) Interfacial (D) Both liquid and gas side
Last Answer : (B) Gas side
Description : Weeping in a distillation column (A) Increases tray efficiency (B) Provides large interfacial surface for mass transfer (C) Results due to very high gas velocity (D) Results due to very low gas velocity
Last Answer : (D) Results due to very low gas velocity
Description : Which of the following is the most controlling factor for the rate of bubble detachment from the hot solid surface? (A) Liquid density (B) Liquid viscosity (C) Hot surface temperature (D) Interfacial tension
Last Answer : (D) Interfacial tension
Description : Solvent deoiling process is used for separating oil and soft wax from hard wax. Methyl iso-butyl ketone and methyl ethyl ketone (MEK) are two commonly used deoiling solvents. Use of former as the deoiling solvent ... nitration temperature (C) Lower solvent dilution ratio (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : Pick out the wrong statement. (A) 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate' (B) In heat exchanger ... vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area
Last Answer : (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted
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 : 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 : In liquid extraction, if the selectivity is unity, then (A) Separation of the constituents is the most effective (B) No separation will occur (C) Amount of solvent required will be minimum (D) Solvent flow rate should be very low
Last Answer : (B) No separation will occur
Description : Oil produced by solvent extraction (A) Has low free fatty acid content (B) Is odourless (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (D) Neither (A) nor (B)
Description : Extraction of penicillin employs a __________ extraction column. (A) Centrifugal (B) Packed (C) Plate (D) None of these
Last Answer : (A) Centrifugal
Description : Tea percolation employs (A) Liquid-liquid extraction (B) Leaching (C) Absorption (D) None of these
Last Answer : (B) Leaching
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 : To get high tray efficiency (A) Interfacial surface between liquid and gas phase should be large (B) Time of contact between the two phases should be less (C) Gas velocity should be very low (D) Liquid entrainment should be severe
Last Answer : (A) Interfacial surface between liquid and gas phase should be large
Description : Extraction of __________ employs an electrolytic process. (A) Aluminium (B) Silver (C) Copper (D) All (A), (B) and (C)
Last Answer : (A) Aluminium
Description : Solvent used in the Udex (glycol) extraction process for removal of light aromatics from cracked naphtha is (A) Propane (B) Diethylene glycol (C) Aqueous solution (10% water) of diethylene glycol (D) Methyl ethyl ketone (MEK)
Last Answer : (C) Aqueous solution (10% water) of diethylene glycol
Description : Solvent used in duo-sol extraction for lube oil upgradation is a mixture of (A) Propane & phenol-cresol mixture (B) Methyl ethyl ketone & glycol (C) Phenol & furfural (D) Propane & liquid sulphur dioxide
Last Answer : (A) Propane & phenol-cresol mixture
Description : Furfural solvent extraction is used for upgrading (by dissolving aromatics) (A) Naphtha (B) Lubricating oils (C) Wax (D) Cracking feedstock
Last Answer : (B) Lubricating oils
Description : Deoiling is the process of removal of oil from wax. It is done by the __________ process. (A) Solvent extraction (B) Sweating (C) Resettling (D) All (A), (B) & (C)
Description : __________ treatment is done for appreciable improvement in viscosity index of lubricating oil. (A) Acid (B) Solvent extraction (C) Alkali (D) Clay
Last Answer : (B) Solvent extraction
Description : Deoiling of wax is done by its (A) Heating (B) Cooling (C) Solvent extraction (D) Both (B) & (C
Last Answer : (D) Both (B) & (C
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 : Solvent extraction is the terminology applied to the liquid-liquid extraction, which is preferred for the separation of the components of liquids, when (A) Extracting solvent is cheaply & abundantly available ... very high (D) One of the liquid components has very high affinity towards the solvent
Last Answer : (D) One of the liquid components has very high affinity towards the solvent
Description : Pick out the wrong statement. (A) The operating line always lies above the equilibrium solubility curve in case of a single component absorber (B) The operating line always lies below the equilibrium ... (D) The solubility of a particular gas in ideal solution in any solvent is always the same
Last Answer : (C) The operating pressure in solvent extraction system should be below vapor pressures of all components
Description : Pick out the correct statement. (A) In case of liquid-liquid extraction, no separation is possible, if the selectivity of the solvent used is unity (B) With increase in temperature, the selectivity of the solvent used ... in solvent extraction is unity at the plait point (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Selectivity of the solvent used in solvent extraction should be (A) 1 (B) > 1 (C) < 1 (D) 0
Last Answer : (B) > 1
Description : The solvent used in liquid-liquid extraction should have __________ less than one. (A) Selectivity (B) Distribution co-efficient (C) Both (A) and (B) (D) Neither (A) nor (B)
Description : Degree of freedom for leaching and solvent extraction process is (A) 0 (B) 1 (C) 2 (D) 3
Last Answer : (D) 3
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
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 : Compound A is extracted from a solution of A + B into a pure solvent S. A Co-current unit is used for the liquid-liquid extraction. The inlet rate of the solution containing A is 200 moles of B/hr.m2 and the ... extraction achieved in the unit is (A) 25% (B) 50% (C) 70% (D) 90%
Last Answer : (B) 50%
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 : 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 : 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) 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 : Perforated plate towers are unique for solvent extraction because, they provide (A) Higher contact area (B) Better contact of the phase (C) Repeated coalescence & redispersion of the drop phase (D) None of these
Last Answer : (C) Repeated coalescence & redispersion of the drop phase
Description : The commonly used solvent in supercritical extraction is (A) Methyl ethyl ketone (B) Water (C) Carbon tetrachloride (D) Carbon dioxide
Last Answer : (D) Carbon dioxide
Description : In a single stage extraction process, 10 kg of pure solvent S (containing no solute A) is mixed with 30 kg of feed F containing A at a mass fraction xf = 0.2. The mixture splits into an extract phase E and a raffinate ... phase is (in Kg) (A) 6.89 (B) 8.89 (C) 10 (D) 8.25
Last Answer : (B) 8.89
Description : Pick out the wrong statement pertaining to solvent extraction of oil. Rate of extraction (A) Decreases with decrease of thickness of the flakes (B) Increases with the increasing flake size ... considerably with the rise of temperature (D) Decreases as the moisture content of flakes increases
Last Answer : (D) Decreases as the moisture content of flakes increases
Description : Essential oils are usually obtained using (A) Steam distillation (B) Extractive distillation (C) Solvent extraction (D) Leaching
Last Answer : (D) Leaching
Description : Solvent used for extraction of oil is (A) Hexane (B) Methyl ethyl ketone (C) Furfural (D) None of these
Last Answer : (A) Hexane
Description : For gas absorption, low viscosity solvents are preferred, because of their (A) Better flow characteristics (B) Low pumping pressure drop (C) Rapid absorption rates (D) All (A), (B) and (C)
Description : Why is sodium carbonate added during solvent extraction?
Last Answer : It is usually added during an extraction in order to make thesolution alkaline. Often times, this aids in the efficiency of theextraction.
Description : Write advantages of water as solvent for extraction
Last Answer : • It is cheap & easily available. • Non –toxic • Non inflammable. • It has wide solvent action
Description : Mass transfer rate between two fluid phases does not necessarily depend on the __________ of the two phases. (A) Chemical properties (B) Physical properties (C) Degree of turbulence (D) Interfacial area
Last Answer : (A) Chemical properties
Description : The rate of mass transfer is not dependent upon the (A) Degree of dispersion of one fluid in the other (B) Interfacial surface exposed between the phases (C) Both (A) & (B) (D) None of these
Last Answer : (D) None of these
Description : Measurement of the interfacial area of mass transfer is achieved easily & accurately in case of a __________ column. (A) Spray (B) Packed (C) Bubble cap plate (D) Wetted wall
Last Answer : (D) Wetted wall