Description : When water is heated it turns into water vapor ' What kind of change is it ?
Last Answer : When water is heated it turns into water vapor ' This is a physical change.
Description : Pick out the wrong statement. (A) The condensing film co-efficient is about 3 times lower for vertical condenser as compared to the equivalent horizontal condenser for identical situation ( ... in a heat exchanger is controlled by the value of the film co-efficient, which is higher
Last Answer : (D) Overall heat transfer co-efficient in a heat exchanger is controlled by the value of the film co-efficient, which is higher
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 : Leidenfrost point is a term concerned with the (A) Condensation of the saturated vapor on a cold surface (B) Concentration of a corrosive solution by evaporation (C) Heat transfer between two highly viscous liquids (D) Boiling of a liquid on a hot surface
Last Answer : (D) Boiling of a liquid on a hot surface
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 : Which is NOT a correct statement? A. A superheated vapor will not condense when small amount of heat re removed B. An ideal gas is a gas that is not a superheated vapor C. A saturated ... absorb as much heat as it can without vaporizing D. Water at 1 atm and room temperature is subcooled
Last Answer : An ideal gas is a gas that is not a superheated vapor
Description : liquid alcohol will change to vapor when its temperature reaches the -General Knowledge
Last Answer : Liquid alcohol will change to vapor when its temperature reaches the boiling point.
Description : What is the answer for the process by water on earths surface changes from liquid to water vapor?
Last Answer : transpiration,i think
Description : When water vapor forms liquid water droplets on a window in the early morning and example?
Last Answer : Need answer
Description : What is a physical process by which vapor becomes liquid or solid the opposite of evaporation?
Last Answer : condensation
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 : Absolute vapor pressure of petrofuels is found by Reid bomb which is heated in water bath to 100°F. In Reid apparatus, the ratio of the volume of air chamber to that of the liquid fuel chamber is (A) 4 (B) 3 (C) 2 (D) 1
Last Answer : (A) 4
Description : __________ is the temperature at which a gas-vapor mixture becomes saturated, when cooled at constant total pressure out of contact with a liquid. (A) Dew point (B) Bubble point (C) Dry bulb temperature (D) Wet bulb temperature
Last Answer : (A) Dew point
Description : The assumption made in Elis method in distillation is that enthalpy concentration lines of vapor and liquid are (A) Parallel (B) Straight (C) Both parallel and straight (D) Neither parallel nor straight
Last Answer : (C) Both parallel and straight
Description : If a two phase system is in physical equilibrium; then it means that, the (A) Escaping tendency of each component from the liquid phase to the vapor phase is exactly equal to that from vapor phase to liquid phase ... liquid phase is equal to that throughout the vapor phase (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : As the reflux ratio in a distillation column is increased from the minimum, the (A) Slope of the operating line in stripping section decreases (B) Number of plates decreases very slowly first ... decreases and then increases (D) Liquid flow increases while the vapor flow decreases for a system
Last Answer : (C) Total cost first decreases and then increases
Description : Which of the following liquid-vapor contacting devices provides maximum contact surface area for a particular duty? (A) Sieve plate column (B) Bubble cap column (C) Randomly packed column (D) Wetted wall column
Last Answer : (D) Wetted wall column
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 : In an operating distillation column, the (A) Vapors and liquids are at their dew point and bubble point respectively (B) Driving force for the liquid flow is its specific weight (C) Driving force for ... bottom to the top of the column (D) Highest temperature is encountered at the top of the column
Last Answer : (C) Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column
Description : On moving the feed line (q-line) from saturated liquid feed (vertical position) to saturated vapor feed (horizontal feed), if the slope of both the operating lines are to be increased, then it will result in (A) Greater degree of separation with a fixed number of trays (B) Increased reboiler load
Last Answer : (C) Increased reflux ratio
Description : Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is __________ the liquid head available in the downcomer. (A) Less than (B) More than (C) Same as (D) Very much less
Last Answer : (B) More than
Description : The equilibrium liquid composition compared to the vapor composition in case of Azeotropic mixture is (A) More (B) Less (C) Same (D) Either more or less; depends on the system
Last Answer : (C) Same
Description : Bound moisture is that liquid which exerts an equilibrium vapor pressure __________ that of the pure liquid at the given temperature. (A) Less than (B) More than (C) Equal to (D) Either (A) or (B); depends on the solid
Last Answer : (A) Less than
Description : In a vapor-liquid contacting equipment, the overall gas phase mass transfer co-efficient (M.T.C), KG is related to individual co-efficients (KG and KL ) as (A) KG = 1/KG + m/KL (B) 1/KG = 1/KG + m/KL (C) 1/KG = 1/KL + m/KG (D) KG = 1/KL + m/KG
Last Answer : (B) 1/KG = 1/KG + m/KL
Description : Relative volatility varies with the concentration of component for an ideal solution. The relative volatility of a binary mixture may be defined as the ratio of vapor pressure of component 'A' to that of ... law (D) Vapor phase obeys Dalton's law and liquid phase obeys Raoult's law
Last Answer : (D) Vapor phase obeys Dalton's law and liquid phase obeys Raoult's law
Description : The separation of liquid droplets from the vapor is done by a/an __________, in the evaporators. (A) Steam ejector (B) Entrainment separator (C) Compressor (D) Vacuum pump
Last Answer : (B) Entrainment separator
Description : Which of the following accessories is provided in the vapor line of an evaporator for removing the entrained liquid? (A) Bleed point (B) Vent (C) Catchall (D) Baffle
Last Answer : (C) Catchall
Description : The purpose of providing a 'catchall' in the vapor line of an evaporator is to (A) Create vacuum (B) Regulate the vapor flow (C) Vent the non-condensable gases (D) Arrest the entrained liquid
Last Answer : (D) Arrest the entrained liquid
Description : The increasing vapor pressure caused by heating a liquid is due to------? A. increase inter-molecular interactions B. increasing potential energy of molecules C. increasing kinetic energy of molecules (Answer) D. decreasing surface tension
Last Answer : C. increasing kinetic energy of molecules (Answer)
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)
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 : In centrifugal pump operation, the cavitation can be eliminated by maintaining suction pressure __________ the vapor pressure of the liquid at the suction temperature. (A) Lower than (B) Higher than (C) Equal to (D) None of these
Last Answer : (B) Higher than
Description : The net positive suction head (NPSH) of a centrifugal pump is defined as the sum of the velocity head and the pressure head at the (A) Discharge (B) Suction (C) Suction minus vapor ... of the liquid at suction temperature (D) Discharge minus vapor pressure of the liquid at the discharge temperature
Last Answer : (C) Suction minus vapor pressure of the liquid at suction temperature
Description : In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes (A) Less than atmospheric pressure (B) More than liquid vapor pressure (C) Less than liquid vapor pressure (D) More than atmospheric pressure
Last Answer : (C) Less than liquid vapor pressure
Description : Smog is (A) Nothing but black smoke (B) A combination of smoke and fog (C) A liquid particle resulting from vapor condensation (D) A solid particle e.g. fly-ash
Last Answer : (B) A combination of smoke and fog
Description : What is the number of degrees of freedom for liquid water in equilibrium with a mixture of nitrogen and water vapor? (A) 2 (B) 0 (C) 3 (D) 1
Last Answer : (A) 2
Description : Boiling of liquid is accompanied with increase in the (A) Vapor pressure (B) Specific Gibbs free energy (C) Specific entropy (D) All (A), (B) and (C)
Last Answer : (A) Vapor pressure
Description : What is the number of degree of freedom for a system of two miscible non-reacting species in vapor-liquid equilibrium forming an azeotrope? (A) 0 (B) 2 (C) 1 (D) 3
Last Answer : (C) 1
Description : Clausius-Clapeyron equation is applicable to __________ equilibrium processes. (A) Solid-vapor (B) Solid-liquid (C) Liquid-vapor (D) All (A), (B) and (C)
Description : A/an __________ system is exemplified by a vessel containing a volatile liquid in contact with its vapor. (A) Isolated (B) Closed (C) Open (D) None of these
Last Answer : (C) Open
Description : What is the degree of freedom for two miscible (non-reacting) substances in vapor-liquid equilibrium forming an azeotrope? (A) 0 (B) 1 (C) 2 (D) 3
Last Answer : (C) 2
Description : The reaction A (l) → R(g) is allowed to reach equilibrium conditions in an autoclave. At equilibrium, there are two phases, one a pure liquid phase of A and the other a vapor phase of A, R and S. Initially A alone is present. The numbers of degrees of freedom are: (A) 1 (B) 2 (C) 3 (D) 0
Last Answer : (B) 2
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 : Which of the following is Clausius-Clapeyron Equation for vaporisation of an ideal gas under the condition that the molar volume of liquid is negligible compared to that of the vapor? (A) d ln p/dt = Hvap/RT2 (B) d ln p/dt = RT2/Hvap (C) dp/dt = RT2/Hvap (D) dp/dt = Hvap/RT2
Last Answer : (A) d ln p/dt = Hvap/RT2
Description : Condensate is the liquid formed when steam passes from the ________ to the ______ state. a. Vapor, solid b. Solid, liquid c. Vapor, liquid d. None
Last Answer : c. Vapor, liquid
Description : The changing of solid directly to vapor without passing through liquid state is called a. Evaporation b. Vaporization c. Sublimation d. Condensation
Last Answer : Sublimation
Description : ___________ is the percent by weight that is saturated liquid. a) Quality, x b) Percent Moisture, y c) Vapor c) Liquid
Last Answer : Percent Moisture, y
Description : ___________ is the percent by weight that is saturated vapor. a) Quality, x b) Percent Moisture, y c) Vapor d) Liquid
Last Answer : Quality, x
Description : __________________ represents the highest pressure and highest temperature at which liquid and vapor can coexist in equilibrium. a) Critical Point b) Boiling Point c) Quality Point d) None of the above
Last Answer : Critical Point