Home

What is the correct answer?

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

Correct Answer :

A. < 0


Related Questions

What is the correct answer?

4

Cp of a gas at its critical temperature and pressure

A. Becomes zero

B. Becomes infinity

C. Equals 1 kcal/kmol °K

D. Equals 0.24 kcal/kmol °K

What is the correct answer?

4

__________ calorimeter is normally used for measuring the dryness fraction of steam, when it is very low.

A. Bucket

B. Throttling

C. Separating

D. A combination of separating & throttling

What is the correct answer?

4

Isobaric process means a constant process.

A. Temperature

B. Pressure

C. Volume

D. Entropy

What is the correct answer?

4

The quantitative effect of temperature on chemical equilibrium is given by the

A. Vant-Hoff equation

B. Le-Chatelier's principle

C. Arrhenius equation

D. None of these

What is the correct answer?

4

In any spontaneous process, the __________ free energy decreases.

A. Helmholtz

B. Gibbs

C. Both a & b

D. Neither 'a' nor 'b'

What is the correct answer?

4

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

What is the correct answer?

4

The standard Gibbs free energy change of a reaction depends on the equilibrium

A. Pressure

B. Temperature

C. Composition

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

What is the correct answer?

4

An isentropic process is carried out at constant

A. Volume

B. Pressure

C. Temperature

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

What is the correct answer?

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

What is the correct answer?

4

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

A. ds = 0

B. ds <0

C. ds > 0

D. ds = Constant

What is the correct answer?

4

Ideal gas law is applicable at

A. Low T, low P

B. High T, high P

C. Low T, high P

D. High T, low P

What is the correct answer?

4

Heat of formation of an element in its standard state is

A. 0

B. < 0

C. > 0

D. A function of pressure

What is the correct answer?

4

Change of state namely evaporation condensation, freezing and melting is an __________ process.

A. Isothermal

B. Adiabatic

C. Isobaric

D. Isochoric

What is the correct answer?

4

The root mean square speed of molecules of a gas is equal to (where, m = mass of the molecule K = Boltzmanns constant, T = absolute temperature)

A. √(2KT/m)

B. √(3KT/m)

C. √(6KT/m)

D. 3KT/m

What is the correct answer?

4

Joule-Thomson effect i.e., a throttling process is a constant __________ process.

A. Entropy

B. Temperature

C. Internal energy

D. Enthalpy

What is the correct answer?

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)

What is the correct answer?

4

When a gas is expanded from high pressure region to low pressure region; temperature change occurs. This phenomenon is related to the

A. Gibbs-Duhem equation

B. Gibbs-Helmholtz equation

C. Third law of thermodynamics

D. Joule-Thomson effect

What is the correct answer?

4

Internal energy change of a system over one complete cycle in a cyclic process is

A. Zero

B. +ve

C. -ve

D. Dependent on the path

What is the correct answer?

4

The number of degrees of freedom for a mixture of ice and water (liquid) are

A. 3

B. 2

C. 1

D. 0

What is the correct answer?

4

The equation DU = Tds - PdV is applicable to infinitesimal changes occuring in

A. An open system of constant composition

B. A closed system of constant composition

C. An open system with changes in composition

D. A closed system with changes in composition

What is the correct answer?

4

Which is an example of closed system?

A. Air compressor

B. Liquid cooling system of an automobile

C. Boiler

D. None of these

What is the correct answer?

4

As the entropy of the universe is increasing, day by day, the work producing capacity of a heat engine is

A. Not changed

B. Decreasing

C. Increasing

D. Data sufficient, can't be predicted

What is the correct answer?

4

When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is

A. More in vapour phase

B. More in liquid phase

C. Same in both the phases

D. Replaced by chemical potential which is more in vapour phase

What is the correct answer?

4

The gas law (PV = RT) is true for an __________ change.

A. Isothermal

B. Adiabatic

C. Both (A) & (B)

D. Neither (A) nor (B)

What is the correct answer?

4

Which of the following will increase the volume of a real gas by four times?

A. Doubling the absolute temperature as well as pressure of the gas

B. Reducing pressure to one fourth at constant temperature

C. Reducing temperature to one fourth at constant pressure

D. Reducing the temperature to half and doubling the pressure

What is the correct answer?

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

What is the correct answer?

4

The value of gas constant 'R' is

A. 1.987 cal/gm mole °K

B. 1.987 BTU/lb. mole °R

C. Both (A) and (B)

D. Neither (A) nor (B)

What is the correct answer?

4

The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.

A. Freezing

B. Triple

C. Boiling

D. Boyle

What is the correct answer?

4

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

What is the correct answer?

4

The free energy change for a chemical reaction is given by (where, K = equilibrium constant)

A. RT ln K

B. -RT ln K

C. -R ln K

D. T ln K