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 << P

1 Answer

Answer :

(A) p = P

Related questions

Description : At a fixed pressure, the humidity depends upon the partial pressure of vapor in the mixture. Humidity of a vapour free gas is __________ percent. (A) 100 (B) 0 (C) 50 (D) Between 0 and 100

Last Answer : (B) 0

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 : 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 : At a fixed total pressure, humidity depends only on the (A) Partial pressure of vapour in the mixture (B) Heat capacity of the vapour (C) Density of the vapour (D) None of these

Last Answer : (A) Partial pressure of vapour in the mixture

Description : When an unsaturated air-water mixture is heated at constant pressure, then (A) The partial pressure of water vapour increases (B) The specific humidity decreases (C) The relative humidity increases (D) The relative humidity decreases

Last Answer : D) The relative humidity decreases

Description : The ratio of partial pressure of water vapour in a mixture to the saturation pressure of water at the same temperature of the mixture is called as A. humidity B. partial humidity C. specific humidity D. relative humidity

Last Answer : ANSWER : D

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 : 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 : The partial molar enthalpy of a component in an ideal binary gas mixture of composition Z, at a temperature T and pressure P, is a function only of (A) T (B) T and P (C) T, P and Z (D) T and Z

Last Answer : (B) T and P

Description : The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents (a) condensation of the refrigerant vapour (b) evaporation of the refrigerant liquid (c) compression of the refrigerant vapour (d) metering of the refrigerant liquid

Last Answer : Ans: b

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 : What is the temperature at which the water vapour in the mixture of water vapour in air, starts condensing called? A. condensation temperature B. dew point temperature C. vaporization temperature D. all of the above

Last Answer : ANSWER : B

Description : Pick out the correct statement about the condensation. (A) Filmwise condensation gives a lower heat transfer rate than the dropwise condensation (B) Suitable coating or vapour additive is used to promote film ... place on it (D) Reynolds number of condensing liquid is based on its mass flow rate

Last Answer : (B) Suitable coating or vapour additive is used to promote film wise condensation

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 : Steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapour-gas mixture is called the __________ temperature. (A) Dry-bulb (B) Wet-bulb (C) Dew point (D) Adiabatic saturation

Last Answer : (B) Wet-bulb

Description : Condensation process refers to : (1) Conversion of water into water vapour (2) Conversion of water vapour into solid form (3) Conversion of water into solid form (4) Conversion of water vapour into its liquid form

Last Answer : (4) Conversion of water vapour into its liquid form Explanation: Condensation is the change of the physical state of matter from gas phase into liquid phase. It is also defined as teh change in the state of water vapour to liquid water when in contact with a liquid or solid surface.

Description : Presence of a non-condensing gas in a condensing vapour (A) Increases the rate of condensation (B) Decreases thermal resistance (C) Is desirable to increase the film co-efficient (D) None of these

Last Answer : (D) None of these

Description : Use of excess of combustion air in the combustion of fuels results in (A) Heat losses (B) Long flame (C) Condensation of water vapour from the fuel gas (D) None of these

Last Answer : (A) Heat losses

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 : Pick out the correct statement. (A) Higher hold up of the solid in the rotary dryer results in better exposure of the solids to the gas (B) The 'Hatta number' is ... reflux in case of distillation operation requires infinite number of plates for a binary system separation

Last Answer : (C) For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is linear in the case of steady state equimolal counter-diffusion

Description : Fugacity of a component in an ideal gas mixture is equal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at constant pressure and ... increases. (A) Decreases (B) Decreases exponentially (C) Increases (D) Remain constant

Last Answer : (C) Increases

Description : In an ideal gas mixture, fugacity of a species is equal to its (A) Vapor pressure (B) Partial pressure (C) Chemical potential (D) None of these

Last Answer : (B) Partial pressure

Description : Pick out the wrong statement. (A) Activity co-efficient is dimensionless. (B) In case of an ideal gas, the fugacity is equal to its pressure. (C) In a mixture of ideal gases, the fugacity of ... equal to the partial pressure of the component. (D) The fugacity co-efficient is zero for an ideal gas

Last Answer : (D) The fugacity co-efficient is zero for an ideal gas

Description : Dew point of a gas-vapour mixture (A) Increases with temperature rise (B) Decreases with temperature rise (C) Decreases with decrease in pressure (D) Increases with increase in pressure

Last Answer : (C) Decreases with decrease in pressure

Description : The relative saturation of a partially saturated mixture of vapour and gas can be increased by __________ of the mixture. (A) Reducing the total pressure (B) Increasing the total pressure (C) Reducing the temperature (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

Description : The wet and 'dry bulb temperature for a vapour-gas mixture are 25°C and 30°C respectively. If the mixture is heated to 45°C at constant pressure, the wet bulb temperature will be __________ °C. (A) 25 (B) > 25 (C) < 25 (D) - 25

Last Answer : (B) > 25

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 remains constant during sensible cooling process? (A) Specific humidity (B) Partial pressure of vapour (C) Both (A) and (B)

Last Answer : (C) Both (A) and (B)

Description : Which of the following remains constant during evaporative cooling process with recirculated water supply? (A) Relative humidity (B) Partial pressure of vapour (C) Wet bulb temperature (D) None of these

Last Answer : (C) Wet bulb temperature

Description : Which of the following decreases during evaporative cooling process with recirculated water supply? (A) Wet bulb temperature (B) Relative humidity (C) Partial pressure of vapour (D) None of these

Last Answer : (D) None of these

Description : Which of the following increases during evaporative cooling process with recirculated water supply? (A) Wet bulb temperature (B) Relative humidity (C) Partial pressure of vapour (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

Description : Moisture content of a substance when at equilibrium with a given partial pressure of the vapour is called the __________ moisture. (A) Free (B) Unbound (C) Equilibrium (D) Bound

Last Answer : (C) Equilibrium

Description : Which of the following parameters remains constant during chemical dehumidification? (A) Dry bulb temperature (B) Partial pressure of vapour (C) Wet bulb temperature (D) None of these

Last Answer : (A) Dry bulb temperature

Description : When dry bulb temperature & wet bulb temperature of moist air is the same, it means that the (A) Partial pressure of water vapour is less than the total pressure (B) Humidity is < 100% & dew ... Dew point temperature of air has not reached & air is not saturated fully (D) Air is fully saturated

Last Answer : (D) Air is fully saturated

Description : The number of degree of freedom for an Azeotropic mixture of ethanol and water in vapour-liquid equilibrium, is (A) 3 (B) 1 (C) 2 (D) 0

Last Answer : B) 1

Description : If a mixture of two gases has a total pressure of 5.7 ATM. If one gas has a partial pressure of 4.1 ATM what is the partial pressure of the other gas?

Last Answer : 1.6 ATM

Description : According to Avogadro's law  A. the product of the gas constant and the molecular mass of an ideal gas is constant  B. the sum of partial pressure of the mixture of two gases is sum of the ... all gases, at the same temperature and pressure, contain equal number of molecules  D. all of the above

Last Answer : Answer: C

Description : According to Avogadro's Hypothesis  (a) the molecular weights of all the perfect gases occupy the same volume under same conditions of pressure and temperature  (b) the sum of partial pressure of ... gases have two values of specific heat  (e) all systems can be regarded as closed systems.

Last Answer : Answer : a

Description : If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as (A) Solubility increases as temperature ... (D) Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution

Last Answer : (B) Solubility increases as temperature decreases

Description : For a solution of volatile liquids, the partial vapour pressure of each component in solution is directly proportional to its (a) Molarity (b) Mole fraction (c) Molality (d) Normality

Last Answer : Ans:(b)

Description : Pressure exerted by fully saturated air, is known (A) Partial pressure (B) Saturation pressure (C) Saturation vapour pressure (D) Both (c) and (d) of the above

Last Answer : Answer: Option D

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 : 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 : Steam trap is used to (A) Condense the steam flowing in the pipeline (B) Remove water resulting from partial condensation of steam (C) Stop the supply of steam (D) None of these

Last Answer : (B) Remove water resulting from partial condensation of steam

Description : Water hammer is caused in steam carrying pipelines, because of (A) Partial condensation of steam (B) Vibration of the pipeline (C) High degree of superheat of steam (D) Its exposure to torrential rain

Last Answer : (A) Partial condensation of steam

Description : LMTD can't be used as such without a correction factor for the (A) Multipass heat exchanger (B) Baffled heat exchanger (C) Condensation of mixed vapour in a condenser (D) All (A) (B) and (C)

Last Answer : (D) All (A) (B) and (C)

Description : Pick out the wrong statement. (A) The mole fraction of solute is directly proportional to the molality of a 'dilute' solution (B) For a non-reacting binary mixture of ideal gases, the partial ... at all temperature (D) The relative volatility of a binary mixture at the Azeotropic composition is 1

Last Answer : (C) Azeotropes obey Raoult's law at all temperature

Description : An air-water vapour mixture has a dry bulb temperature of 60°C and a dew point temperature of 40°C. The total pressure is 101.3 kPa and the vapour pressure of water at 40°C and 60°C are 7.30 kPa and 19.91 kPa respectively ... air is: (A) 0.048 (B) 0.079 (C) 0.122 (D) 0.152

Last Answer : (D) 0.152

Description : 5. In "Imperial Smelting Process" for extraction of zinc, zinc vapour thus produced is quenched in the external condenser by the use of the following: (A) Jet of water at high pressure (B) Blast of air (C) Mixture of water and air (D) Rain of molten lead

Last Answer : Option D

Description : The temperature to which a vapour gas mixture must be cooled (at varying humidity) to become saturated is called the __________ temperature. (A) Dew point (B) Wet bulb (C) Dry bulb (D) None of these

Last Answer : (D) None of these