steam distillation, the (A) Temperature is 100°C(B) Temperature is more than 100° C (C) Product must be immiscible with water (D) Temperature is higher than the boiling point of either component
(C) Product must be immiscible with water
Description : Steam at 100°C causes more severe burns than water at 100° C because – (1) steam has no specific heat capacity (2) steam has latent heat of vaporization (3) water has no specific heat capacity (4) water has latent heat of fusion
Last Answer : (2) steam has latent heat of vaporization Explanation: It is because steam releases its latent heat as it condenses, which is substantial. The heat of vaporization of steam is over 2000 J per gram. And when it releases that it's then 100 degree water, the same as boiling water.
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 : 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 : Steam distillation is used for separation of high boiling (A) Substances from non-volatile impurities (B) Volatile impurity from still higher boiling substances (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : Explain ,why an organic liquid vapourises at a temperature below its boiling point in steam distillation?
Last Answer : Because for boiling to occur vapour pressure of organic compound & steam should be equal to atmospheric pressure. As vapour pressure of water is higher than organic liquid. Therefore, organic liquid vaporizes at a temperature below its boiling point in steam distillation .
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 : Steam at 1000C causes more severe burns than water at 100° C because (1) steam has no specific heat capacity (2) steam has latent heat of vaporisation (3) water has no specific heat capacity (4) water has latent heat of fusion
Last Answer : steam has latent heat of vaporisation
Description : A liquid with high boiling point decomposes on simple distillation but it can be steam distilled for its purification .Explain how is it possible?
Last Answer : In steam distillation boiling occurs when vapour pressure of organic compound & steam becomes equal to atmospheric pressure. As vapour pressure of water is higher than the organic liquid. ... organic liquid vaporizes at a temperature below its boiling point in steam distillation without decomposing.
Description : Give any two applications of simple distillation.Describe method of separation of two immiscible liquids.
Last Answer : Applications of simple distillation(0.5 2) 1) Preparation of distilled water and water for injection. 2)Recovery of alcohol in preparation of dry extracts 3)Many volatile oils and ... proportion The distillate can be collected in Florentine receiver for separation of oil & water.
Description : Describe the method of distillation for immiscible solution.
Last Answer : Method of separation of two immiscible liquids. The apparatus consists of steam generator,still,condenser,and receiver. In steam distillation process, a current of steam is passed through a immiscible ... be collected in Florentine receiver for separation of oil & water. Diagram:
Description : A long iron rod initially at a temperature of 20°C has one end dipped in boiling water (100°C) at time, t = 0. The curved surface of the rod is insulated so that heat conduction is one dimensional in the axial direction. The ... = 283 s (B) t = 356 s (C) t = 400 s (D) t = 800 s
Last Answer : (D) t = 800 s
Description : Solvent naphtha' used mostly as a solvent in paints and perfumery is produced by the __________ of virgin naphtha into small boiling range cuts. (A) Steam reforming (B) Distillation (C) Desulphurisation (D) None of these
Last Answer : (B) Distillation
Description : The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and recondensed, then the liquid with the next higher boiling point is then evaporated and ... is called A. cracking B. carbonisation C. fractional distillation D. full distillation
Last Answer : Answer: C
Description : . A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of ... in a single effect is much lower than that in any effect in a multi-effect system
Last Answer : (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect
Description : Langmuir equation is associated with (A) Leaching (B) Adsorption (C) Steam distillation (D) Multi-component absorption
Last Answer : (B) Adsorption
Description : Steam distillation is used to (A) Reduce the number of plates (B) Avoid thermal decomposition of a component (C) Increase the efficiency of separation (D) Increase the total pressure of distillation
Last Answer : (B) Avoid thermal decomposition of a component
Description : The boiling temperature of the water in the radiator is raised to abouta) 100°C b) 105°C c) 110° C d) 115° C
Last Answer : c) 110° C
Description : The boiling point of ammonia is (a) -100°C (b) -50°C (c) - 33.3°C (d) 33.3°C.
Last Answer : Ans: c
Description : 31 Scalding with steam is more severe than scalding by boiling water because A. Steam can penetrate the skin B. Steam is at a higher temperature C. Steam contains more energy than boiling water D. Steam is at a higher pressure
Last Answer : ANSWER: C
Description : Scalding with steam is more severe than scalding by boiling water because (a) steam can penetrate the skin (b) steam is at a higher temperature (c) steam contains more energy than boiling water (d) steam is at a higher pressure
Last Answer : Ans:(c)
Description : Burns caused by steam are much severe than those caused by boiling water because – (1) Steam pierces through the pores of body quickly (2) Steam has latent heat (3) Steam is gas and engulfs the body quickly (4) Temperature of steam is higher
Last Answer : (2) Steam has latent heat Explanation: When water changes into steam, it absorbs latent heat, and when steam condenses to form water, it gives out an equal amount of latent heat. Bums caused ... boiling water, simply because steam contains more heat (in the form of latent heat) than boiling water.
Description : Burns caused by steam are much severe than those caused by boiling water because (1) Steam pierces through the pores of body quickly (2) Steam has latent heat (3) Steam is gas and engulfs the body quickly (4) Temperature of steam is higher
Last Answer : Steam has latent heat
Description : Water always boils when its (A) Temperature reaches 100° C (B) Vapour pressure equals 76 cm of Hg (C) Saturated vapour pressure equals the external pressure on its surface (D) Saturated vapour pressure is less than the atmospheric pressure
Last Answer : (C) Saturated vapour pressure equals the external pressure on its surface
Description : One kilogram of water at 0°C is changed to superheated steam of one atm pressure and 300° C. The major heat consumption in the process will be to (A) Heat the water from 0°C to 100°C (B) Evaporate the water (C) To superheat the steam (D) Data insufficient, can't be predicted
Last Answer : (B) Evaporate the water
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 : Pick out the wrong statement. (A) Economy of a multiple effect evaporator is not influenced by the boiling point elevation (B) Two identical cubes of iron and copper will have the same heat ... in the field of refrigeration (D) Finned tube heat exchangers are suitable for heating air by steam
Last Answer : (B) Two identical cubes of iron and copper will have the same heat content under the same conditions of temperature
Description : Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation ... (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades
Last Answer : (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades
Description : Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low ... prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these
Last Answer : (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose
Description : Oxygen is separated by distillation from air after its liquefaction. The boiling point of oxygen is about __________ °C. (A) -83 (B) -183 (C) -196 (D) -218
Last Answer : (B) -183
Description : In a distillation operation, what is the effect of the temperature of the reflux stream (given below) on the condenser and reboiler loads? Reflux conditions: (i) Reflux stream is completely liquid ... D) Both condenser and reboiler loads are higher in case (ii) as compared to case (i)
Last Answer : (D) Both condenser and reboiler loads are higher in case (ii) as compared to case (i)
Description : Helical screw agitator is used for (A) Mixing highly viscous pastes (B) Blending immiscible liquids (C) Mixing liquids at very high temperature (> 250 °C) (D) None of these
Last Answer : (A) Mixing highly viscous pastes
Description : In distillation, overhead product contains (A) Only one component (B) Two components (C) Any number of components (D) Only saturated liquid
Last Answer : (C) Any number of components
Description : The temperature of a liquid is 32° F. What is its temperature in Celsius scale? (1) 32° C (2) 0° C (3) 100° C (4) 212° C
Last Answer : (2) 0° C
Description : At what temperature a body will not radiate any heat energy? (1) 0° C (2) 273° C (3) 100° C (4) -273° C
Last Answer : (4) -273° C
Last Answer : 0° C
Description : In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapour, because (A) Temperature is less (B) Total pressure is less (C) Mixing of steam ... not so intimate as to result in equilibrium condition (D) Saturated steam is used for steam distillation
Last Answer : (C) Mixing of steam with the material being vaporised is not so intimate as to result in equilibrium condition
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 : The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by (A) Raising the temperature (B) Lowering the total pressure (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B
Description : DNA is (A) Usually present in tissues as a nucleo protein and cannot be separated from its protein component (B) A long chain polymer in which the internucleotide linkages are of the diester type between C-3 ... linkages are between C-2' and C-5' (D) Hydrolyzed by weal alkali (pH9 to 100°C)
Last Answer : Answer : B
Description : In catalytic alkylation, higher iso-butane to olefin ratio gives (A) Low final boiling point product (B) Higher yield (C) Both (A) and (B) (D) Neither (A) nor (B
Last Answer : (A) Low final boiling point product
Description : Two liquids (A)and(B)are separated by fractional distillation, the boiling point of (A) is less than (B).which liquid comes out first in distillate? Explain.
Last Answer : The liquid (a) comes out first in distillate. On boiling the vapours of lower boiling component are formed first.
Description : Light oil whose major component is Benzol, is obtained by the distillation of crude tar in the temperature range of __________ °C. (A) 80-170 (B) 200-300 (C) 250-270
Last Answer : (A) 80-170
Description : Catalytic cracking compared to thermal cracking of residue of vacuum distillation of crude oil (A) Gives higher yield of petrol (B) Lower octane number of petrol (C) Higher sulphur content in the product (D) Higher gum forming material in petro
Last Answer : (A) Gives higher yield of petrol
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 : Which of the following processes can remove both temporary as well as permanent hardness of water? (A) Filtration (B) Boiling (C) Distillation (D) None of these
Last Answer : (C) Distillation
Description : The actual temperature drop across the heating surface of an evaporator depends on the (A) Liquid depth over the heating surface (B) Solution being evaporated (C) Pressure difference between the steam chest and the vapor space above the boiling liquid (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C
Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C
Description : Nitrobenzene (boiling point = 210.6°C) is steam distilled at 1 atm pressure. Nitrobenzene will distil off __________ °C. (A) At < 100 (B) At > 210.6 (C) Between 100 and 210 (D) None of these
Last Answer : (A) At < 100
Description : Pick out the wrong statement: (A) The capacity of an evaporator is reduced by the boiling point elevation (B) Corrosive liquid is normally passed through the tubes in a ... recompression evaporator (D) Heat sensitive materials should be concentrated in high pressure evaporators
Last Answer : (D) Heat sensitive materials should be concentrated in high pressure evaporators
Description : Products drawn from the top to bottom of the crude oil distillation column has progressively increasing (A) Boiling points (B) Molecular weight (C) C/H ratio (D) All (A), (B) and (C)