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4

As the temperature is lowered towards the absolute zero, the value of ∂(ΔF)/∂T, then approaches

A. Unity

B. Zero

C. That of the heat of reaction

D. Infinity

Correct Answer :

B. Zero


Related Questions

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4

All gases except __________ shows a cooling effect during throttling process at atmospheric temperature and pressure.

A. Oxygen

B. Nitrogen

C. Air

D. Hydrogen

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4

Which of the following equations is obtained on combining 1st and 2nd law of thermodynamics, for a system of constant mass?

A. dE = Tds - PdV

B. dQ = CvdT + PdV

C. dQ = CpdT + Vdp

D. Tds = dE - PdV

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4

Heat is added at constant temperature in an ideal __________ cycle.

A. Stirling

B. Brayton

C. Rankine

D. None of these

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4

Entropy change for an irreversible isolated system is

A.

B. 0

C. < 0

D. > 0

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4

An ideal gas is taken around the cycle ABCA as shown in P-V diagram below: The work done by the gas during the cycle is equal to

A. 12 P1V1

B. 6 P1 V1

C. 3 P1V1

D. P1 V1

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4

The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise.

A. Increases

B. Decreases

C. Remains unchanged

D. Decreases linearly

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4

Which of the following is not a common refrigerant?

A. Freon-12

B. Ethylene

C. Ammonia

D. Carbon dioxide

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4

The equation relating E, P, V and T which is true for all substances under all conditions is given by (∂E/∂V)T = T(∂P/∂T)H - P. This equation is called the

A. Maxwell's equation

B. Thermodynamic equation of state

C. Equation of state

D. Redlich-Kwong equation of state

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4

Entropy is a/an

A. State function

B. Macroscopic property

C. Extensive property

D. None of these

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4

Pick out the wrong statement.

A. An ideal liquid or solid solution is defined as one in which each component obeys Raoult's law

B. If Raoult's law is applied to one component of a binary mixture; Henry's law or Raoult's law is applied to the other component also

C. Henry's law is rigorously correct in the limit of infinite dilution

D. None of these

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4

Number of components (C), phase (P) and degrees of freedom (F) are related by Gibbs phase rule as

A. P + F - C = 2

B. C = P - F + 2

C. F = C - P - 2

D. P = F - C - 2

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4

Pick out the wrong statement.

A. The values of (∂P/∂V)T and (∂2P/∂V2)T are zero for a real gas at its critical point

B. Heat transferred is equal to the change in the enthalpy of the system, for a constant pressure, non-flow, mechanically reversible process

C. Thermal efficiency of a Carnot engine depends upon the properties of the working fluid besides the source & sink temperatures

D. During a reversible adiabatic process, the entropy of a substance remains constant

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4

The work done in an adiabatic change in a particular gas depends upon changes in the __________ only.

A. Temperature

B. Specific heat

C. Volume

D. Pressure

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4

Fugacity co-efficient of a substance is the ratio of its fugacity to

A. Mole fraction

B. Activity

C. Pressure

D. Activity co-efficient

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4

The compressibility factor of a gas is given by (where, V1 = actual volume of the gas V2 = gas volume predicted by ideal gas law)

A. V1/V2

B. V2/V1

C. V1 - V2

D. V1.V2

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4

The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances. This is the

A. Lewis-Randall rule

B. Statement of Van't Hoff Equation

C. Le-Chatelier's principle

D. None of these

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4

Dryness fraction of wet steam is defined as the ratio of mass of vapour in the mixture to the mass of mixture __________ calorimeter is not used for measuring the dryness fraction of steam.

A. Bomb

B. Separating

C. Bucket

D. Throttling

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4

Entropy is a measure of the __________ of a system.

A. Disorder

B. Orderly behaviour

C. Temperature changes only

D. None of these

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4

The thermodynamic law, PVy = constant, is not applicable in case of

A. Ideal compression of air

B. Free expansion of an ideal gas

C. Adiabatic expansion of steam in a turbine

D. Adiabatic compression of a perfect gas

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4

On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line (∂P/ ∂V)T are related as (where, y = Cp/Cv)

A. (∂P/∂V)S = (∂P/∂V)T

B. (∂P/∂V)S = [(∂P/∂V)T]Y

C. (∂P/∂V)S = y(∂P/∂V)T

D. (∂P/∂V)S = 1/y(∂P/∂V)T

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4

Which of the following behaves most closely like an ideal gas?

A. He

B. N2

C. O2

D. H2

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4

Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature.

A. Infinity

B. Minus infinity

C. Zero

D. None of these

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4

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

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4

For a constant volume process

A. dE = CpdT

B. dE = CvdT

C. dQ = dE + pdV

D. dW = pdV

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4

Tea kept in a thermos flask is vigorously shaken. If the tea is considered as a system, then its temperature will

A. Increase

B. Decrease

C. Remain unchanged

D. First fall and then rise

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4

A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect?

A. Vapor compression cycle using expansion valve

B. Air refrigeration cycle

C. Vapor compression cycle using expansion engine

D. Carnot refrigeration cycle

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4

Reduced pressure of a gas is the ratio of its

A. Pressure to critical pressure

B. Critical pressure to pressure

C. Pressure to pseudocritical pressure

D. Pseudocritical pressure to pressure

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4

The internal energy of an incompressible fluid depends upon its

A. Pressure

B. Temperature

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

To obtain integrated form of Clausius-Clapeyron equation, ln (P2/P1) = (ΔHV/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)

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4

Free energy

A. Decreases in all spontaneous (or irreversible) processes

B. Change during a spontaneous process has a negative value

C. Remains unchanged in reversible processes carried at constant temperature and pressure

D. All (A), (B) and (C)