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

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
by

1 Answer

Answer :

(C) Transition
by

Related questions

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

Description : 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

Last Answer : C) Transition

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

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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

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

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

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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

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0.257g of organic substance was heated with conc. sulphuric acid and then distilled with excess of strong alkali .the ammonia gas evolved was absorbed in 50ml of .1M HCl which required 23.2ml of c for neutralization at the end of the process. Determine the % of nitrogen in the compound ?

Description : 0.257g of organic substance was heated with conc. sulphuric acid and then distilled with excess of strong alkali .the ammonia gas evolved was absorbed in 50ml of .1M HCl which required 23.2ml of c for neutralization at the end of the process. Determine the % of nitrogen in the compound ?

Last Answer : A. Vol of 0 .1M HCl taken = 50ml Vol of .1MNaOH used for neutralization of unused acid=23.2ml Now, 23.2 ml of .1MNaOH =23.2ml of .1MHCl Vol of .1MHCl unused=23.2ml Vol of .1MHCl required ... NH3 solution contain nitrogen = 14*26.8/10*1000 Percentage of Nitrogen=14*26.8*100/10*1000*.257 =14.6%

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

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Under what condition, the heat evolved or absorbed in a reaction is equal to its free energy change?

Description : Under what condition, the heat evolved or absorbed in a reaction is equal to its free energy change?

Last Answer : Ans. As ΔG = ΔH – TΔS. Thus, ΔG = ΔH only when either the reaction is carried out at 0^0 K or the reaction is not accompanied by any entropy change, i.e., ΔS = 0

Under what condition, the heat evolved/absorbed in a reaction is equal to its free energy change?

Description : Under what condition, the heat evolved/absorbed in a reaction is equal to its free energy change?

Last Answer : Ans. In ∆G = ∆H – T. ∆S, when reaction is carried out at 0 K or ∆S = 0, then ∆G = ∆H.

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)

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

The change in enthalpy, when a unit quantity of gas is absorbed by relatively large quantity of adsorbent (on which a definite concentration of the adsorbed gas already exists) is termed as the (A) Differential heat of adsorption (B) Heat of wetting (C) Integral heat of adsorption (D) None of these

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Last Answer : (A) Differential heat of adsorption

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

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

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)

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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.

For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia acid absorbed in 60 mL of `M/10`

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One gram of `Na_(3)AsO_(4)` is boiled with excess of solid `KI` in presence of strong `HCl`. The iodine evolved is absorbed in `KI` solution and titra

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Last Answer : One gram of `Na_(3)AsO_(4)` is boiled with excess of solid `KI` in presence of strong `HCl`. The iodine evolved ... B. 38.4 mL C. 24.7 mL D. 30.3 mL

Respiratory quotient (RQ) is equal to a. Volume of CO2 evolved/Volume of O2 absorbed b. Volume of CO2 absorbed/Volume of O2 evolved c. Volume of CO2 evolved/Volume of O2 evolved d. Volume of CO2 absorbed/Volume of O2 absorbed

Description : Respiratory quotient (RQ) is equal to a. Volume of CO2 evolved/Volume of O2 absorbed b. Volume of CO2 absorbed/Volume of O2 evolved c. Volume of CO2 evolved/Volume of O2 evolved d. Volume of CO2 absorbed/Volume of O2 absorbed

Last Answer : a. Volume of CO2 evolved/Volume of O2 absorbed

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)

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

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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

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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

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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

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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

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

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Last Answer : (A) Liquid extraction

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

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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

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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)

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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

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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

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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

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Last Answer : (A) Loosing sensible heat

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 vaporisation is constant (C) Volume in the liquid state is negligible compared with that in the vapour state (D) All (A), (B) and (C)

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)

High __________ is an undesirable property for a good refrigerant. (A) Specific heat (B) Latent heat of vaporisation (C) Viscosity (D) Specific vapor volume

Description : High __________ is an undesirable property for a good refrigerant. (A) Specific heat (B) Latent heat of vaporisation (C) Viscosity (D) Specific vapor volume

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ick out the undesirable property for a good refrigerant. (A) High thermal conductivity (B) Low freezing point (C) Large latent heat of vaporisation (D) High viscosity

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The critical pressure at which the latent heat of vaporisation of steam becomes zero is __________ Kg/cm2. (A) 273.15 (B) 225.65 (C) 100.03 (D) 373.15

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Last Answer : (B) 225.65

The phase transition of a liquid to a solid  a. Solidification  b. Freezing  c. Fusion  d. All of these

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Pick out the wrong statement. (A) Yellow phosphorous which is the most reactive allotropic form of phosphorous is transported under water (B) Apatite is the principal material present in phosphate rock which is chemically Ca10 (PO4 )6 (F, Cl, OH) (C) Urea is more hygroscopic than ammonium nitrate (D) Nitrogen fixation means the process of bringing atmospheric nitrogen into combination i.e. into nitrogen compound fo

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The most stable allotropic form of phosphorous is the __________ phosphorous. (A) White (B) Black (C) Yellow (D) Red

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Last Answer : (B) Black

The most reactive allotropic form of phosphorus is __________ phosphorus. (A) Red (B) Yellow (C) Violet (D) Black

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Heat requirement for decomposition of a compound into its elements is __________ that is evolved during the formation of that compound from its elements. (A) The same (B) Less than (C) Greater than (D) Different than

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Pick out the wrong statement. (A) Tin can be readily and very easily drawn into very fine wire (B) Tin can be severely cold worked without the necessity of annealing due to its low recrystallisation temperature (C) Tin exists in two allotropic forms

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Titanium metal (A) Exists in three allotropic forms (B) Cannot be welded (C) Is used in oceanographic and space exploration applications (D) None of these

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