Description : Vacuum filter is most suitable for the (A) Removal of fines from liquid (B) Liquids having high vapour pressure (C) Liquids of very high viscosity (D) None of these
Last Answer : (D) None of these
Description : A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yiis the liquid activity co- ... and liquid composition xi only (D) Temperature, pressure, liquid composition xi and vapour composition yi
Last Answer : (C) Temperature, pressure and liquid composition xi only
Description : Vacuum is generally maintained in the vapour space of an evaporator mainly to (A) Get economical temperature difference by using moderate pressure steam (B) Facilitate forward ... (C) Concentrate heat sensitive materials (D) Achieve very high concentration of the final product
Last Answer : (A) Get economical temperature difference by using moderate pressure steam
Description : An ideal liquid refrigerant should (A) Not have a sub-atmospheric vapour pressure at the temperature in the refrigerator coils (B) Not have unduly high vapour pressure at the condenser temperature (C) Both (A) and (B) (D) Have low specific heat
Last Answer : (C) Both (A) and (B)
Description : When liquid and vapour phase of multi-component system are in equilibrium (at a given temperature and pressure), then chemical potential of each component is (A) Same in both the phases (B) Zero in both the phases (C) More in vapour phase (D) More in liquid phase
Last Answer : (A) Same in both the phases
Description : When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is (A) More in vapour phase (B) More in liquid phase (C) Same in both the phases (D) Replaced by chemical potential which is more in vapour phase
Last Answer : (C) Same in both the phases
Description : Probability of cavitation occuring becomes very high, when the local __________ resulting in water bubbles formation, which on rupture cause cavitation (A) Pressure falls below the vapour pressure (B) Pressure becomes very high (C) Temperature becomes low (D) All 'a', 'b' & 'c'
Last Answer : (D) All 'a', 'b' & 'c'
Description : Which one of the following statements most accurately relates the properties of a liquid at room temperature with its vapour pressure? A A liquid with a low vapour pressure will probably have a ... with a high vapour pressure will probably have high intermolecular forces and a low boiling point.
Last Answer : A A liquid with a low vapour pressure will probably have a high surface tension and a high boiling point.
Description : Clausius-Clapeyron Equation gives accurate result, when the (A) Vapour pressure is relatively low and the temperature does not vary over wide limits (B) Vapour obeys the ideal gas law and the latent heat of ... is negligible compared with that in the vapour state (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Use of water as a manometric liquid suffers from the disadvantage of its (A) Low vapour pressure (B) Corrosive nature (C) High vapour pressure (D) High boiling point
Last Answer : (C) High vapour pressure
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 : At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole ... respectively. Activity co-efficient of methanol is (A) 1.572 (B) 1.9398 (C) 3.389
Last Answer : (A) 1.572
Description : For water at 300°C, it has a vapour pressure 8592.7 kPa and fugacity 6738.9 kPa Under these conditions, one mole of water in liquid phase has a volume of 25.28 cm3 and that in vapour phase in 391.1 cm3.Fugacity of water (in kPa) at 9000 kPa will be (A) 6738.9 (B) 6753.5 (C) 7058.3 (D) 9000
Last Answer : (B) 6753.5
Description : If the vapour pressure at two temperatures of a solid phase in equilibrium with its liquid phase are known, then the latent heat of fusion can be calculated by the (A) Maxwell's equation (B) Clausius-Clapeyron Equation (C) Van Laar equation (D) Nernst Heat Theorem
Last Answer : B) Clausius-Clapeyron Equation
Description : Activity co-efficient is a measure of the (A) Departure from ideal solution behaviour (B) Departure of gas phase from ideal gas law (C) Vapour pressure of liquid (D) None of these
Last Answer : (A) Departure from ideal solution behaviour
Description : To obtain integrated form of Clausius-Clapeyron equation, ln (P2/P1) = (∆HV/R) (1/T1- 1/T2) from the exact Clapeyron equation, it is assumed that the (A) Volume of the liquid phase is negligible compared to ... gas (C) Heat of vaporisation is independent of temperature (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : The composition of fresh feed to the high temperature, high pressure urea autoclave is (A) Excess liquid ammonia and liquefied CO2 (B) Excess liquid ammonia and compressed CO2 gas (C) Liquid ammonia and excess compressed CO2 (D) Compressed ammonia gas and excess compressed CO2
Last Answer : (B) Excess liquid ammonia and compressed CO2 gas
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 : In sub-cooled boiling, (A) Temperature of the heating surface is less than the boiling point of the liquid (B) Temperature of the heating surface is more than the boiling point of the liquid (C) ... from heating surface are absorbed by the mass of the liquid (D) Very large vapour space is necessary
Last Answer : (B) Temperature of the heating surface is more than the boiling point of the liquid
Description : To remove very small amount of tiny solid impurities from liquid, we use a (A) Pressure filter (B) Vacuum filter (C) Centrifugal filter (D) Coagulant
Last Answer : (D) Coagulant
Description : Clapeyron Equation deals with the (A) Rate of change of vapour pressure with temperature (B) Effect of an inert gas on vapour pressure (C) Calculation of ΔF for spontaneous phase change (D) Temperature dependence of heat of phase transition
Last Answer : (A) Rate of change of vapour pressure with temperature
Description : In saturated gas, the (A) Vapour is in equilibrium with the liquid at the gas temperature (B) Vapour is in equilibrium with the liquid at the room temperature (C) Partial pressure of vapour equals the vapour pressure of the liquid at room temperature (D) None of these
Last Answer : (A) Vapour is in equilibrium with the liquid at the gas temperature
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 : Moisture in a substance exerting an equilibrium vapour pressure less than that of pure liquid at the same temperature is called the __________ moisture. (A) Bound (B) Unbound (C) Critical (D) None of these
Last Answer : (A) Bound
Description : Relative humidity is the ratio of the (A) Partial pressure of the vapour to the vapour pressure of the liquid at room temperature (B) Partial pressure of the vapour to the vapour pressure of the liquid at gas temperature (C) Actual humidity to saturation humidity (D) None of these
Last Answer : (B) Partial pressure of the vapour to the vapour pressure of the liquid at gas temperatur
Description : Moisture in a solid exerting an equilibrium vapour pressure equal to that of the pure liquid at the same temperature is called the __________ moisture. (A) Unbound (B) Critical (C) Free (D) Bound
Last Answer : (A) Unbound
Description : The actual temperature drop across the heating surface in an evaporator depends on the (A) Feed (B) Depth of liquid over heating surface (C) Pressure difference between steam chest and vapour space (D) All (A), (B) and (C)
Description : Cavitation occurs in a centrifugal pump when the suction pressure is (A) Less than the vapour pressure of the liquid at that temperature (B) Greater than the vapour pressure of the liquid at that temperature (C) Equal to the vapour pressure (D) Equal to the developed head
Last Answer : (A) Less than the vapour pressure of the liquid at that temperature
Description : A liquid under pressure greater than its vapour pressure for the temperature involved is called a __________ liquid. (A) Sub-cooled (B) Saturated (C) Non-solidifiable (D) None of these
Last Answer : (A) Sub-cooled
Description : Routine maintenance of dry-type transformers should include ____________. A. cleaning the windings, if accessible, with a vacuum cleaner or very low pressure air B. measuring and recording the winding ... . making sure that the units are close to bulkheads or corners to protect them from damage
Last Answer : Answer: A
Description : Plasma is (A) A high temperature neutral gas (B) Nothing but ionised gas (C) A source of steady and highest controllable pressure (D) Formed at very low temperature
Last Answer : (B) Nothing but ionised gas
Description : In stripping section of continuous distillation column, the (A) Liquid is stripped of high boiler (B) Liquid is enriched with high boiler (C) Vapour is stripped of low boiler (D) None of these
Last Answer : (B) Liquid is enriched with high boiler
Description : In rectifying section of a continuous distillation column, the (A) Vapour is enriched with low boilers (B) Vapour is enriched with high boilers (C) Liquid is stripped of high boilers (D) None of these
Last Answer : (B) Vapour is enriched with high boilers
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 : Mercury is often used in barometer because (A) It is the best liquid (B) The height of barometer will be less (C) Its vapour pressure is so low that it may be neglected (D) Both (B) and (C)
Last Answer : Answer: Option D
Description : Pick out the wrong statement: (A) The vacuum pressure is always the negative gauge pressure (B) The pressure of the liquid measured by a piezometer tube is the gauge pressure (C) Manometric ... point at which the resultant pressure on an immersed surface acts, is known as the centre of gravity
Last Answer : (D) The point at which the resultant pressure on an immersed surface acts, is known as the centre of gravity
Description : Higher vapour pressure of gasoline indicates (A) Low flash point (B) High breathing loss (C) Both (A) and (B) (D) Neither (A) nor (B
Last Answer : (D) Neither (A) nor (B
Description : Which of the following is an undesirable property of a manometricliquid? (A) Non-sticky & non-corrosive nature (B) High vapour pressure (C) Low viscosity & surface tension (D) Low co-efficient of thermal expansion
Last Answer : (B) High vapour pressure
Description : The condition of refrigerant before entering the expansion or throttle valve, in a vapour compression system (a) dry vapour (b) wet vapour (c)liquid-vapour mixture (d) high pressure saturated liquid
Last Answer : Ans: d
Description : In vapour compression cycle, the condition of refrigerant is high pressure saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) before entering the expansion valve
Description : Vapour lock is a. complete or partial stoppage of fuel supply due to vaporization of the fuel b. locking of carburetor due to high vapor pressure c. excess fuel supply to the engine d. supply of liquid fuel to the engine
Last Answer : ANSWER a. complete or partial stoppage of fuel supply due to vaporization of the fuel
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
Description : Condensation of a vapour-gas mixture just begins, when (where, p = partial pressure of the vapour P = vapour pressure of the liquid). (A) p = P (B) p >>P (C) p < P (D) p
Last Answer : (A) p = P
Description : Back-trapping in a distillation column (A) Increases tray efficiency (B) Decreases tray efficiency (C) Reduces pressure drop (D) Is desirable, as it provides improved vapour-liquid contact
Last Answer : (B) Decreases tray efficiency
Description : In Azeotropic mixture, the equilibrium vapour composition is (A) More than liquid composition (B) Less than liquid composition (C) Same as liquid composition (D) Independent of pressure
Last Answer : (C) Same as liquid composition
Description : Henry's law states that the (A) Partial pressure of a component over a solution is proportional to its mole fraction in the liquid (B) Partial pressure of a component over a solution ... pressure (D) Partial pressure is equal to the product of the mole fraction and total pressure
Last Answer : (A) Partial pressure of a component over a solution is proportional to its mole fraction in the liquid
Description : Net positive suction head (NPSH) of a centrifugal pump must be (A) Greater than the vapour pressure of the liquid (B) Less than the vapour pressure of the liquid (C) Equal to the vapour pressure of the liquid (D) Less than barometric pressure
Last Answer : (A) Greater than the vapour pressure of the liquid
Description : The head developed by a centrifugal pump is largely determined by the (A) Power of the pump (B) Nature of the liquid being pumped (C) Angle of the vanes and the speed of the tip of the impeller (D) Vapour pressure of the liquid
Last Answer : (C) Angle of the vanes and the speed of the tip of the impeller
Description : At triple point (for one component system), vapour pressure of solid as compared to that of liquid will be (A) More (B) Less (C) Same (D) More or less; depending on the system
Last Answer : (C) Same
Description : One of the purposes of sub-cooling the liquid refrigerant is to (a) reduce compressor overheating (b) reduce compressor discharge temperature (c) increase cooling effect (d) ensure that only liquid and not the vapour enters the expansion (throttling) valve