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
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 : Pick out the wrong statement. (A) Packed towers are preferred for vacuum operation, because the pressure drop through the packing is less and they (packings) also lessen the ... of liquid, problem of channelling, loading & flooding is generally encountered in packed towers
Last Answer : (C) Diameter of randomly packed tower is normally more than 1.2 metres
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 : Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the ... C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these
Last Answer : (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments
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 : 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 : Which of the following equipments is not used for gas dispersion? (A) Agitated vessels (B) Bubble cap tray towers (C) Perforated sieve tray towers (D) Spray towers
Last Answer : (D) Spray towers
Description : The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives (A) Low pressure drop and high hold up (B) High pressure drop and low hold ... C) Low pressure drop and low hold up (D) High pressure drop and high hold up
Last Answer : (C) Low pressure drop and low hold up
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 : 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 : . The most widely used crude topping column in refineries is the__________ column. (A) Bubble-cap (B) Packed bed (C) Fluidised bed (D) Perforated plate
Last Answer : (A) Bubble-cap
Description : Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the (A) High evaporation losses of water (B) High pressure drop of the gas (C) Difficulty in its fabrication (D) None of these
Last Answer : (B) High pressure drop of the gas
Description : Out of the following gas-liquid contacting devices, for a given set of operating conditions, gas pressure drop is the least in __________ tower. (A) Wetted wall (B) Bubble cap (C) Perforated tray (D) Packed
Last Answer : (A) Wetted wall
Description : Which of the following gas-liquid contacting devices incurs the least pressure drop for a particular duty? (A) Grid tray tower (B) Perforated tray tower (C) Wetted wall tower (D) Bubble cap tower
Last Answer : (D) Bubble cap tower
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 : 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)
Last Answer : (D) All (A), (B) & (C)
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 : 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 : 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 : Lamina dura is actually: A. Cortical bone B. Spongy bone C. Immature bone D. Cribriform plate perforated by nutrition canals
Last Answer : D. Cribriform plate perforated by nutrition canals
Description : Which of the following equipments is not used in liquid-liquid extraction? (A) Pachuka tank (B) Agitated vessels (C) Centrifugal extractors (D) Packed towers
Last Answer : (A) Pachuka tank
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 : 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 : 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 : __________ 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 : 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 : 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 : Fractional solvent extraction (A) Employs only one solvent (B) Employs two solvents (C) Results in low interfacial tension (D) None of these
Last Answer : (B) Employs two solvents
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 : 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 : 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 : 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 : Stacked packing compared to dumped packing (A) Provides poorer contact between the fluids (B) Gives lower pressure drop (C) Both (A) and (B) (D) Gives higher pressure drop
Last Answer : (C) Both (A) and (B)
Description : Very tall packed towers are divided into series of beds to (A) Reduce the overall pressure drop (B) Avoid channelling (C) Reduce liquid hold-up (D) Avoid flooding
Last Answer : (B) Avoid channelling
Description : The main reason for dividing a tall packed tower into series of small towers is to (A) Minimise the overall pressure drop (B) Avoid flooding (C) Reduce liquid hold up (D) Avoid channelling
Last Answer : (D) Avoid channelling
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)
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 : 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 : Electrometallurgical methods of metal extraction is normally used for those metals (A) Whose oxide/ore is not reduced by carbon (B) Which fall in the category of alkali & alkaline earth metals (C) Which stands higher in the electrochemical series of the metal (D) All (A), (B) & (C)
Description : Sieve tubes are suited for translocation of food because they possess (a) bordered pits (b) no end walls (c) broader lumen and perforated cross walls (d) no protoplasm
Last Answer : (c) broader lumen and perforated cross walls