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What is the correct answer?

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

Correct Answer :

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


Related Questions

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4

During adiabatic expansion of gas

A. Pressure remains constant

B. Pressure is increased

C. Temperature remains constant

D. None of these

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4

For a spontaneous process, free energy

A. Is zero

B. Increases

C. Decreases whereas the entropy increases

D. And entropy both decrease

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4

Which of the following units is not present in both the vapor compression refrigeration system and absorption refrigeration system?

A. Expansion valve

B. Condenser

C. Refrigerator

D. Compressor

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4

__________ increases with increase in pressure.

A. The melting point of wax

B. The boiling point of a liquid

C. Both (A) and (B)

D. Neither (A) nor (B)

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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)

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4

In an ideal solution, the activity of a component equals its

A. Mole fraction

B. Fugacity at the same temperature and pressure

C. Partial pressure

D. None of these

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4

Which is not constant for an ideal gas?

A. (∂P/∂V)T

B. (∂V/∂T)P

C. (∂P/∂V)V

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

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4

In the reaction, represented by, 2SO2 + O2 2SO3; ΔH = - 42 kcal; the forward reaction will be favoured by

A. Low temperature

B. High pressure

C. Both (A) and (B)

D. Neither (A) nor (B)

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4

Pick out the wrong statement.

A. The chemical potential of a pure substance depends upon the temperature and pressure

B. The chemical potential of a component in a system is directly proportional to the escaping tendency of that component

C. The chemical potential of ith species (μi) in an ideal gas mixture approaches zero as the pressure or mole fraction (xi) tends to be zero at constant temperature

D. The chemical potential of species 'i' in the mixture (μi) is mathematically represented as,μi = ∂(nG)/∂ni]T,P,nj where, n, ni and nj respectively denote the total number of moles, moles of ith species and all mole numbers except ith species. 'G' is Gibbs molar free energy

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4

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

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4

Henry's law is closely obeyed by a gas, when its __________ is extremely high.

A. Pressure

B. Solubility

C. Temperature

D. None of these

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4

Pick out the correct statement.

A. Entropy and enthalpy are path functions

B. In a closed system, the energy can be exchanged with the surrounding, while matter cannot be exchanged

C. All the natural processes are reversible in nature

D. Work is a state function

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4

The shape of T-S diagram for Carnot Cycle is a

A. Rectangle

B. Rhombus

C. Trapezoid

D. Circle

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4

When dilute aqueous solutions of two salts are mixed, the process is associated with

A. Decrease in temperature

B. Increase in temperature

C. No change in temperature

D. Change in temperature which is a function of composition

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4

Consider the reaction, C + O2 CO2; ΔH = - 94 kcal. What will be the value of ΔH for the reaction CO2 → C + O2?

A. -94 kcal

B. +94 kcal

C. > 94 kcal

D. < -94 kcal

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4

Mollier diagram is a plot of

A. Temperature vs. enthalpy

B. Temperature vs. enthalpy

C. Entropy vs. enthalpy

D. Temperature vs. internal energy

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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

For an ideal gas, the enthalpy

A. Increases with rise in pressure

B. Decreases with rise in pressure

C. Is independent of pressure

D. Is a path function

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4

A cylinder contains 640 gm of liquid oxygen. The volume occupied (in litres) by the oxygen, when it is released and brought to standard conditions (0°C, 760 mm Hg) will be __________ litres.

A. 448

B. 224

C. 22.4

D. Data insufficient; can't be computed

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4

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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4

Heat of formation of an element in its standard state is

A. 0

B. < 0

C. > 0

D. A function of pressure

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4

(∂H/∂T)P is the mathematical expression for

A. CV

B. Entropy change

C. Gibbs free energy

D. None of these

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4

A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, Δ S1 and Δ SR are the entropy changes of the system for the irreversible and reversible processes respectively)

A. Δ S1 is always < Δ SR

B. Δ S1 is sometimes > Δ SR

C. Δ S1 is always > Δ SR

D. Δ S1 is always = Δ SR

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4

An irreversible process

A. Is the analog of linear frictionless motion in machines

B. Is an idealised visualisation of behaviour of a system

C. Yields the maximum amount of work

D. Yields an amount of work less than that of a reversible process

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4

Specific __________ does not change during phase change at constant temperature and pressure.

A. Entropy

B. Gibbs energy

C. Internal energy

D. Enthalpy

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4

The principle applied in liquefaction of gases is

A. Adiabatic expansion

B. Joule-Thomson effect

C. Both (A) and (B)

D. Neither (A) nor (B)

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4

Which is a state function?

A. Specific volume

B. Work

C. Pressure

D. Temperature

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4

A reasonably general expression for vapourliquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of

A. Temperature only

B. Temperature and pressure only

C. Temperature, pressure and liquid composition xi only

D. Temperature, pressure, liquid composition xi and vapour composition yi

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4

For a multi-component system, the term chemical potential is equivalent to the

A. Molal concentration difference

B. Molar free energy

C. Partial molar free energy

D. Molar free energy change

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4

In jet refrigerators, the refrigerating fluid is practically always

A. Water

B. Ammonia

C. Freon

D. Brine