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4

The standard state of a gas (at a given temperature) is the state in which fugacity is equal to

A. Unity

B. Activity

C. Both (A) & (B)

D. Neither (A) nor (B)

Correct Answer :

C. Both (A) & (B)


Related Questions

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4

Joule-Thomson experiment is

A. Isobaric

B. Adiabatic

C. Isenthalpic

D. Both (B) & (C)

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4

The chemical potential of a component (μi) of a phase is the amount by which its capacity for doing all work, barring work of expansion is increased per unit amount of substance added for an infinitesimal addition at constant temperature and pressure. It is given by

A. (∂E/∂ni)S, v, nj

B. (∂G/∂ni)T, P, nj = (∂A/∂ni) T, v, nj

C. (∂H/∂ni)S, P, nj

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

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4

With increase in pressure (above atmospheric pressure), the Cp of a gas

A. Increases

B. Decreases

C. Remains unchanged

D. First decreases and then increases

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4

The Maxwell relation derived from the differential expression for the Helmholtz free energy (dA) is

A. (∂T/∂V)S = - (∂P/∂S)V

B. (∂S/∂P)T = - (∂V/∂T)P

C. (∂V/∂S)P = (∂T/∂P)S

D. (∂S/∂V)T = (∂P/∂T)V

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4

Pick 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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4

Pick out the wrong statement.

A. The conversion for a gas phase reaction increases with decrease in pressure, if there is an increase in volume accompanying the reaction

B. With increase in temperature, the equilibrium constant increases for an exothermic reaction

C. The equilibrium constant of a reaction depends upon temperature only

D. The conversion for a gas phase reaction increases with increase in pressure, if there is a decrease in volume accompanying the reaction

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4

Fugacity is a measure of the

A. Escaping tendencies of the same substance in different phases of a system

B. Relative volatility of a mixture of two miscible liquids

C. Behaviour of ideal gases

D. None of these

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4

For spontaneous changes in an isolated system (S = entropy)

A. ds = 0

B. ds <0

C. ds > 0

D. ds = Constant

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4

The chemical potential of any constituent of an ideal solution depends on the __________ of the solution.

A. Temperature

B. Pressure

C. Composition

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

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4

Joule-Thomson co-efficient which is defined as, η = (∂T/∂P)H = 1/Cp (∂H/∂T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is

A. 0

B.

C. +ve

D. -ve

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4

Pick out the correct equation relating 'F' and 'A'.

A. F = A + PV

B. F = E + A

C. F = A - TS

D. F = A + TS

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4

Which of the following is not an intensive property?

A. Chemical potential

B. Surface tension

C. Heat capacity

D. None of these

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4

In a turbine, the fluid expands almost

A. Isothermally

B. Isobarically

C. Adiabatically

D. None of these

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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

For an ideal liquid solution, which of the following is unity?

A. Activity

B. Fugacity

C. Activity co-efficient

D. Fugacity co-efficient

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4

Pick out the wrong statement:

A. The expansion of a gas in vacuum is an irreversible process

B. An isometric process is a constant pressure process

C. Entropy change for a reversible adiabatic process is zero

D. Free energy change for a spontaneous process is negative

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4

When a system is in equilibrium for all possible processes, the differential or finite change of entropy is

A. < 0

B. > 0

C. = 0

D. None of these

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4

Critical solution temperature (or the consolute temperature) for partially miscible liquids (e.g., phenol-water) is the minimum temperature at which

A. A homogeneous solution (say of phenol water) is formed

B. Mutual solubility of the two liquids shows a decreasing trend

C. Two liquids are completely separated into two layers

D. None of these

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4

At __________ point, all the three phases (i.e. solid, liquid and gas) co-exist.

A. Eutectic

B. Triple

C. Plait

D. Critical

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4

Fugacity and pressure are numerically equal, when the gas is

A. In standard state

B. At high pressure

C. At low temperature

D. In ideal state

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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

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

At equilibrium condition, the chemical potential of a material in different phases in contact with each other is equal. The chemical potential for a real gas (μ) is given by (where, μ = standard chemical potential at unit fugacity (f° = 1 atm.) and the gas behaves ideally.)

A. μ° + RT ln f

B. μ°+ R ln f

C. μ° + T ln f

D. μ° + R/T ln f

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4

For an ideal gas, the internal energy depends upon its __________ only.

A. Molecular size

B. Temperature

C. Volume

D. Pressure

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4

For an ideal gas, the chemical potential is given by

A. RT d ln P

B. R d ln P

C. R d ln f

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

Linde gas liquefaction process employs cooling

A. By throttling

B. By expansion in an engine

C. At constant pressure

D. None of these

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4

The change in __________ is equal to the reversible work for compression in steady state flow process under isothermal condition.

A. Internal energy

B. Enthalpy

C. Gibbs free energy

D. Helmholtz free energy

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4

Heat of reaction at constant volume is identified with __________ change.

A. Enthalpy

B. Internal energy

C. Either (A) or (B)

D. Neither (A) nor (B)

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4

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