Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of (A) Sublimation (B) Fusion (C) Transition (D) Vaporisation

Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of
(A) Sublimation
(B) Fusion
(C) Transition
(D) Vaporisation
by

1 Answer

Answer :

C) Transition
by

Related questions

Heat evolved/absorbed during conversion of a substance from one allotropic form to another is termed as the heat of (A) Fusion (B) Vaporisation (C) Transition (D) None of these

Description : Heat evolved/absorbed during conversion of a substance from one allotropic form to another is termed as the heat of (A) Fusion (B) Vaporisation (C) Transition (D) None of these

Last Answer : (C) Transition

Conversion of a substance directly from solid to vapour state is known as (a) Vaporisation (b) Sublimation (c) Decomposition (d) Ionisation

Description : Conversion of a substance directly from solid to vapour state is known as (a) Vaporisation (b) Sublimation (c) Decomposition (d) Ionisation

Last Answer : Ans:(b)

Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of (A) Solution (B) Vaporisation (C) Formation (D) Sublimation

Description : Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of (A) Solution (B) Vaporisation (C) Formation (D) Sublimation

Last Answer : (B) Vaporisation

Specific/molar Gibbs free energy for a pure substance does not change during (A) Sublimation (B) Vaporisation (C) Melting (D) Either (A), (B) or (C)

Description : Specific/molar Gibbs free energy for a pure substance does not change during (A) Sublimation (B) Vaporisation (C) Melting (D) Either (A), (B) or (C)

Last Answer : (D) Either (A), (B) or (C)

When vaporisation takes place through a blanketting film of gas, the phenomenon is termed as __________ boiling. (A) Pool (B) Nucleate (C) Transition (D) Film

Description : When vaporisation takes place through a blanketting film of gas, the phenomenon is termed as __________ boiling. (A) Pool (B) Nucleate (C) Transition (D) Film

Last Answer : (D) Film

Pick out the wrong statement. (A) 'Green acid' is the other name of phosphoric acid produced by the reaction of phosphate rock & sulphuric acid (B) Chemically unreactive nature of red phosphorous is due to its polymeric structure (C) Red phosphorous is the most reactive allotropic form of phosphorous (D) Red phosphorous, which is used in the manufacture of safety matches, is converted into white phosphorous by vaporisation followed by condensation

Description : Pick out the wrong statement. (A) 'Green acid' is the other name of phosphoric acid produced by the reaction of phosphate rock & sulphuric acid (B) Chemically unreactive nature of ... in the manufacture of safety matches, is converted into white phosphorous by vaporisation followed by condensation

Last Answer : (C) Red phosphorous is the most reactive allotropic form of phosphorous

Pick out the wrong statement. (A) Minimum number of degree of freedom of a system is zero (B) Degree of freedom of a system containing a gaseous mixture of helium, carbon dioxide and hydrogen is 4 (C) For a two phase system in equilibrium made up of fourchemical species, the number of degrees of freedom is 4 (D) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation

Description : Pick out the wrong statement. (A) Minimum number of degree of freedom of a system is zero (B) Degree of freedom of a system containing a gaseous mixture of helium, carbon ... ) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation

Last Answer : (D) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation

Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.). (A) Entropy (B) Internal energy (C) Enthalpy (D) Gibbs free energy

Description : Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.). (A) Entropy (B) Internal energy (C) Enthalpy (D) Gibbs free energy

Last Answer : (D) Gibbs free energy

_________ does not change during phase transformation processes like sublimation, melting & vaporisation. (A) Entropy (B) Gibbs free energy (C) Internal energy (D) All (A), (B) & (C)

Description : _________ does not change during phase transformation processes like sublimation, melting & vaporisation. (A) Entropy (B) Gibbs free energy (C) Internal energy (D) All (A), (B) & (C)

Last Answer : (B) Gibbs free energy

_________ is the transition of a given substance from the solid to the gas phase with no intermediate liquid stage.  a. Convection  b. Conduction  c. Radiation  d. Sublimation

Description : _________ is the transition of a given substance from the solid to the gas phase with no intermediate liquid stage.  a. Convection  b. Conduction  c. Radiation  d. Sublimation

Last Answer : Sublimation

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

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

Heat sensitive materials with very high latent heat of vaporisation may be economically separated using (A) Liquid extraction (B) Distillation (C) Evaporation (D) Absorption

Description : Heat sensitive materials with very high latent heat of vaporisation may be economically separated using (A) Liquid extraction (B) Distillation (C) Evaporation (D) Absorption

Last Answer : (A) Liquid extraction

What is defined as the direct conversion of a substance from the solid to the vapor state or vice versa without passing the liquid state?  A. Condensation  B. Vaporization  C. Sublimation  D. Cryogenation

Description : What is defined as the direct conversion of a substance from the solid to the vapor state or vice versa without passing the liquid state?  A. Condensation  B. Vaporization  C. Sublimation  D. Cryogenation

Last Answer : Sublimation

When a bottle of scent is kept open in a corner of a room its odour is felt in all parts of the room. This is clue to the phenomenon of – (1) evaporation (2) vaporisation (3) diffusion (4) sublimation

Description : When a bottle of scent is kept open in a corner of a room its odour is felt in all parts of the room. This is clue to the phenomenon of – (1) evaporation (2) vaporisation (3) diffusion (4) sublimation

Last Answer : (3) diffusion Explanation: Diffusion is one of several transport phenomena that occur in nature. A distinguishing feature of diffusion is that it results in mixing or mass transport without requiring ... are other transport mechanisms that use bulk motion to move particles from One place to another.

When a bottle of scent is kept open in a corner of a room its odour is felt in all parts of the room. This is due to the phenomenon of : (1) evaporation (2) vaporisation (3) diffusion (4) sublimation

Description : When a bottle of scent is kept open in a corner of a room its odour is felt in all parts of the room. This is due to the phenomenon of : (1) evaporation (2) vaporisation (3) diffusion (4) sublimation

Last Answer : diffusion

The heat absorbed by a unit mass of a material at its holding point in order to convert the material into a gas at the same temperature.  a. Latent Heat of Sublimation  b. Latent Heat of Vaporization  c. Latent Heat of Fusion  d. Latent Heat Of Condensation

Description : The heat absorbed by a unit mass of a material at its holding point in order to convert the material into a gas at the same temperature.  a. Latent Heat of Sublimation  b. Latent Heat of Vaporization  c. Latent Heat of Fusion  d. Latent Heat Of Condensation

Last Answer : Latent Heat of Vaporization

Gibbs free energy per mole for a pure substance is equal to the (A) Latent heat of vaporisation (B) Chemical potential (C) Molal boiling point (D) Heat capacity

Description : Gibbs free energy per mole for a pure substance is equal to the (A) Latent heat of vaporisation (B) Chemical potential (C) Molal boiling point (D) Heat capacity

Last Answer : (B) Chemical potential

The phenomenon occuring during pumping of a liquid solution containing dissolved gases, which may come out of the solution giving rise to gas pockets, is termed as (A) Evaporation (B) Cavitation (C) Sublimation (D) Stripping

Description : The phenomenon occuring during pumping of a liquid solution containing dissolved gases, which may come out of the solution giving rise to gas pockets, is termed as (A) Evaporation (B) Cavitation (C) Sublimation (D) Stripping

Last Answer : (B) Cavitation

Which of the following assumes constant molal vaporisation and overflow?(A) McCabe-Thiele method (B) Ponchan-Savarit method (C) Enthalpy concentration method (D) Plate absorption column

Description : Which of the following assumes constant molal vaporisation and overflow? (A) McCabe-Thiele method (B) Ponchan-Savarit method (C) Enthalpy concentration method (D) Plate absorption column

Last Answer : (A) McCabe-Thiele method

An equipment which converts the latent or sensible heat of one fluid into the latent heat of vaporisation of another, is called a (A) Boiler (B) Heat exchanger (C) Recuperator (D) Regenerato

Description : An equipment which converts the latent or sensible heat of one fluid into the latent heat of vaporisation of another, is called a (A) Boiler (B) Heat exchanger (C) Recuperator (D) Regenerato

Last Answer : (B) Heat exchanger

Heat is generated in a nuclear reactor (thermal) by (A) Combustion of a nuclear fuel e.g. uranium (B) Fusion of atoms of uranium (C) Absorption of neutrons in uranium atoms (D) Fission of U-235 by neutrons

Description : Heat is generated in a nuclear reactor (thermal) by (A) Combustion of a nuclear fuel e.g. uranium (B) Fusion of atoms of uranium (C) Absorption of neutrons in uranium atoms (D) Fission of U-235 by neutrons

Last Answer : (D) Fission of U-235 by neutrons

Define the following : Sublimation , Melting Point , Fusion , Evaporations , Boiling Point , Vapourization , Condensation , Deposition.

Description : Define the following : Sublimation , Melting Point , Fusion , Evaporations , Boiling Point , Vapourization , Condensation , Deposition.

Last Answer : Ans : Sublimation : Sublimation is the process in which some solids upon heating instead of changing into liquid state are converted directly into gaseous (vapour) state. Example : Ammonium Chloride ... happens from the gaseous phase into the solid phase directly, the change is called deposition.

The process of a solid converting directly into a gas is called: w) fusion x) sublimation y) condensation z) distillation

Description : The process of a solid converting directly into a gas is called: w) fusion x) sublimation y) condensation z) distillation

Last Answer : ANSWER: X -- SUBLIMATION 

Physical absorption is (A) An irreversible phenomenon (B) A reversible phenomenon (C) Accompanied by evolution of heat (D) Both (B) and (C)

Description : Physical absorption is (A) An irreversible phenomenon (B) A reversible phenomenon (C) Accompanied by evolution of heat (D) Both (B) and (C)

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

Absorption accompanied by heat evolution results in (A) Increased capacity of the absorber (B) Increase in equilibrium solubility (C) Decrease in equilibrium solubility (D) None of these

Description : Absorption accompanied by heat evolution results in (A) Increased capacity of the absorber (B) Increase in equilibrium solubility (C) Decrease in equilibrium solubility (D) None of these

Last Answer : (C) Decrease in equilibrium solubility

Absorption (liquid-gas system) with evolution of heat as compared to isothermal absorption results in (A) Decreased solute solubility (B) Large minimum liquid to gas (L/G) ratio (C) Large number of trays(D) All (A), (B) and (C)

Description : Absorption (liquid-gas system) with evolution of heat as compared to isothermal absorption results in (A) Decreased solute solubility (B) Large minimum liquid to gas (L/G) ratio (C) Large number of trays (D) All (A), (B) and (C)

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

Pick out the correct statement. (A) A chemical reaction accompanied by absorption of heat is called an exothermic reaction (B) A chemical reaction accompanied by evolution of heat is called an endothermic reaction (C) The rate constant for a first order reaction does not change on changing the concentration units (D) Chemical equilibrium state is dynamic in nature

Description : Pick out the correct statement. (A) A chemical reaction accompanied by absorption of heat is called an exothermic reaction (B) A chemical reaction accompanied by evolution of heat is called an ... does not change on changing the concentration units (D) Chemical equilibrium state is dynamic in nature

Last Answer : (C) The rate constant for a first order reaction does not change on changing the concentration units

The change in Gibbs free energy for vaporisation of a pure substance is (A) Positive (B) Negative (C) Zero (D) May be positive or negative

Description : The change in Gibbs free energy for vaporisation of a pure substance is (A) Positive (B) Negative (C) Zero (D) May be positive or negative

Last Answer : (C) Zero

Fuel' can be defined as a substance which produces heat by (A) Combustion (B) Nuclear fission (C) Nuclear fusion (D) All (A), (B) & (C)

Description : Fuel' can be defined as a substance which produces heat by (A) Combustion (B) Nuclear fission (C) Nuclear fusion (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C

Solar energy is converted into chemical energy during – (1) Combustion (2) Transition (3) Photosynthesis (4) Fusion

Description : Solar energy is converted into chemical energy during – (1) Combustion (2) Transition (3) Photosynthesis (4) Fusion

Last Answer : (3) Photosynthesis Explanation: Photosynthesis in plants converts radiant energy from the sun into chemical energy in the form of glucose (sugar) using electrons and protons from water. Plants take in water, carbon dioxide, and sunlight and turn them into glucose and oxygen.

Pick out the wrong statement. (A) Surface tension of a substance vanishes at critical point, as there is no distinction between liquid and vapour phases at its critical point (B) Entropy of a system decreases with the evolution of heat (C) Change of internal energy is negative for exothermic reactions (D) The eccentric factor for all materials is always more than one

Description : Pick out the wrong statement. (A) Surface tension of a substance vanishes at critical point, as there is no distinction between liquid and vapour phases at its critical point (B) Entropy of ... is negative for exothermic reactions (D) The eccentric factor for all materials is always more than one

Last Answer : (D) The eccentric factor for all materials is always more than one

The evolution of heat of solution takes place in ammonia absorption plant when (a) ammonia vapour goes into solution (b) ammonia vapour is driven out of solution (c) lithium bromide mixes with ammonia (d) weak solution mixes with strong solution

Description : The evolution of heat of solution takes place in ammonia absorption plant when (a) ammonia vapour goes into solution (b) ammonia vapour is driven out of solution (c) lithium bromide mixes with ammonia (d) weak solution mixes with strong solution

Last Answer : Ans: a

Entrainer used in Azeotropic distillation should (A) Form a low boiling azeotrope with one of the constituents of the mixture (B) Form a new azeotrope of low relative volatility with one of the constituents of the mixture (C) Have high latent heat of vaporisation (D) Have high viscosity to provide high tray efficiency

Description : Entrainer used in Azeotropic distillation should (A) Form a low boiling azeotrope with one of the constituents of the mixture (B) Form a new azeotrope of low relative volatility with one of the ... (C) Have high latent heat of vaporisation (D) Have high viscosity to provide high tray efficiency

Last Answer : (A) Form a low boiling azeotrope with one of the constituents of the mixture

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 that of vapour phase (B) Vapour phase behaves as an ideal gas (C) Heat of vaporisation is independent of temperature (D) All (A), (B) & (C)

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)

Heat which causes a change in temperature of a substance.  a. Latent heat  b. Sensible heat  c. Specific heat  d. Heat of Fusion

Description : Heat which causes a change in temperature of a substance.  a. Latent heat  b. Sensible heat  c. Specific heat  d. Heat of Fusion

Last Answer : Sensible heat

The ______ of a substance is the amount of heat that must be added or removed from a unit mass of the substance to change its temperature by one degree.  A. Latent heat of fusion  B. Molar heat  C. Specific heat capacity  D. Specific heat

Description : The ______ of a substance is the amount of heat that must be added or removed from a unit mass of the substance to change its temperature by one degree.  A. Latent heat of fusion  B. Molar heat  C. Specific heat capacity  D. Specific heat

Last Answer : Specific heat capacity

What is defined as the energy required to raise the temperature of a unit mass of a substance by one degree?  A. Latent heat of fusion  B. Molar heat  C. Specific heat capacity  D. Specific heat

Description : What is defined as the energy required to raise the temperature of a unit mass of a substance by one degree?  A. Latent heat of fusion  B. Molar heat  C. Specific heat capacity  D. Specific heat

Last Answer : Specific heat

What is the amount of heat needed to turn 1kg of the substance at its boiling point from the liquid to the gaseous state?  A. Heat of fusion  B. Heat of vaporation  C. Heat of condensation  D. Heat of fission

Description : What is the amount of heat needed to turn 1kg of the substance at its boiling point from the liquid to the gaseous state?  A. Heat of fusion  B. Heat of vaporation  C. Heat of condensation  D. Heat of fission

Last Answer : Heat of vaporation

What is the amount of heat needed to turn 1 kg of the substance at its melting point from the solid to liquid state?  A. Heat of fusion  B. Heat of vaporation  C. Heat of condensation  D. Heat of fission

Description : What is the amount of heat needed to turn 1 kg of the substance at its melting point from the solid to liquid state?  A. Heat of fusion  B. Heat of vaporation  C. Heat of condensation  D. Heat of fission

Last Answer : Heat of fusion

Which of the following terms refer to the amount of heat needed to raise the temperature of a unit mass of a substance through one degree? w) Heat of fusion x) Liquification heat y) Internal heat z) Specific heat

Description : Which of the following terms refer to the amount of heat needed to raise the temperature of a unit mass of a substance through one degree? w) Heat of fusion x) Liquification heat y) Internal heat z) Specific heat

Last Answer : ANSWER: Z -- SPECIFIC HEAT

The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the 'Curie temperature'. Its value for cobalt is __________ °C. (A) 768 (B) 1127 (C) 1359 (D) 1480

Description : The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the 'Curie temperature'. Its value for cobalt is __________ °C. (A) 768 (B) 1127 (C) 1359 (D) 1480

Last Answer : (B) 1127

In distillation column design, the McCabe-Thiele procedure is inadequate and a Ponchan-Savarit procedure is needed, when (A) Saturated feed is not used (B) An azeotrope forms (C) The latent heat of vaporisation of the more and less volatile components are greatly different (D) A total condenser is used

Description : In distillation column design, the McCabe-Thiele procedure is inadequate and a Ponchan-Savarit procedure is needed, when (A) Saturated feed is not used (B) An azeotrope forms (C) The latent ... vaporisation of the more and less volatile components are greatly different (D) A total condenser is used

Last Answer : (D) A total condenser is used

When the solvent dissolves very little of solute, then (A) Solvent of low latent heat of vaporisation should be used (B) Solvent of low freezing point should be used (C) Large quantity of solvent is required to extract the solute (D) Very small quantity of solvent is required

Description : When the solvent dissolves very little of solute, then (A) Solvent of low latent heat of vaporisation should be used (B) Solvent of low freezing point should be used (C) Large quantity of solvent is required to extract the solute (D) Very small quantity of solvent is required

Last Answer : (C) Large quantity of solvent is required to extract the solute

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 be recovered by distillation (C) Its recovery cost by distillation may be prohibitively high (D) It will decompose while recovering by distillation

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

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 (B) Film co-efficient for vaporisation decreases as a result of vapor binding (C) In industrial practice, sub-cooling of condensate is required, when thecondensate is a volatile liquid and is to be transferred for storage(D) Overall heat transfer co-efficient in a heat exchanger is controlled by thevalue of the film co-efficient, which is higher

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

Rate of heat transfer by vaporisation from pools of water is affected by the (A) Nature of heating surface and distribution of bubbles (B) Surface tension of water (C) Viscosity of water (D) All (A), (B) and (C)

Description : Rate of heat transfer by vaporisation from pools of water is affected by the (A) Nature of heating surface and distribution of bubbles (B) Surface tension of water (C) Viscosity of water (D) All (A), (B) and (C)

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

Pick out the wrong statement. (A) Heat transfer by radiation cannot occur across an absolute volume (B) In case of a shell and tube heat exchanger, the pressure drop through the shell is proportional to the number of times the fluid crosses the bundle between baffles (C) Propagation velocity for travel of heat radiation through vacuum is equal to the velocity of the light (D) The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same

Description : Pick out the wrong statement. (A) Heat transfer by radiation cannot occur across an absolute volume (B) In case of a shell and tube heat exchanger, the pressure drop through the shell is ... The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same

Last Answer : (A) Heat transfer by radiation cannot occur across an absolute volume

It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/kg.K. The rate at which the heat has to be supplied in (kJ/min) to the evaporator is (A) 3.06 × 10 5 (B) 6.12 × 10 5 (C) 7.24 × 10 5 (D) 9.08 × 10

Description : It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of ... 3.06 10 5 (B) 6.12 10 5 (C) 7.24 10 5 (D) 9.08 10

Last Answer : (A) 3.06 × 10

In a cooling tower, water becomes cool by (A) Loosing sensible heat (B) Heat transfer to surroundings (C) Vaporisation due to heat loss to air (D) Loosing latent heat

Description : In a cooling tower, water becomes cool by (A) Loosing sensible heat (B) Heat transfer to surroundings (C) Vaporisation due to heat loss to air (D) Loosing latent heat

Last Answer : (A) Loosing sensible heat