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What is the correct answer?

4

Entropy change in case of reversible adiabatic process is

A. Minimum

B. Zero

C. Maximum

D. Indeterminate

Correct Answer :

B. Zero


Related Questions

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4

Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is

A. Positive

B. Negative

C. Zero

D. Infinity

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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

An ideal monatomic gas is taken round the cycle ABCDA as shown below in the P-V diagram. The work done during the cycle is

A. PV

B. 2PV

C. PV/2

D. 0

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4

Throttling process is a/an __________ process.

A. Reversible and isothermal

B. Irreversible and constant enthalpy

C. Reversible and constant entropy

D. Reversible and constant enthalpy

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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

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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

What is the number of degrees of freedom for liquid water in equilibrium with a mixture of nitrogen and water vapor?

A. 2

B. 0

C. 3

D. 1

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4

Equation which relates pressure, volume and temperature of a gas is called the

A. Equation of state

B. Gibbs Duhem equation

C. Ideal gas equation

D. None of these

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4

Consider the process A & B shown in the figure given below: In this case, it is possible that

A. Both the processes are adiabatic

B. Both the processes are isothermal

C. Process A is isothermal while B is adiabatic

D. Process A is adiabatic while B is isothermal

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4

Clausius-Clapeyron equation is applicable to __________ equilibrium processes.

A. Solid-vapor

B. Solid-liquid

C. Liquid-vapor

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

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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)

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4

The total change in the enthalpy of a system is independent of the

A. Number of intermediate chemical reactions involved

B. Pressure and temperature

C. State of combination and aggregation in the beginning and at the end of the reaction

D. None of these

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4

The temperature at which both liquid and gas phases are identical, is called the __________ point.

A. Critical

B. Triple

C. Freezing

D. Boiling

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4

The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible __________ process.

A. Isobaric

B. Isothermal

C. Adiabatic

D. None of these

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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)

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4

In an irreversible process

A. Tds = dE - dW = 0

B. dE - dW - Tds = 0

C. Tds - dE + dW < 0

D. Tds - dT + dW < 0

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4

If different processes are used to bring about the same chemical reaction, the enthalpy change is same for all of them. This is __________ law.

A. Hess's

B. Kirchoff's

C. Lavoisier and Laplace

D. None of these

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4

For an ideal gas, the activity co-efficient is

A. Directly proportional to pressure

B. Inversely proportional to pressure

C. Unity at all pressures

D. None of these

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4

Isotherm on an enthalpy-concentration diagram, for an ideal solution will be a

A. Straight line

B. Sine curve

C. Parabola

D. Hyperbola

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4

If an ideal solution is formed by mixing two pure liquids in any proportion, then the __________ of mixing is zero

A. Enthalpy

B. Volume

C. Both 'a' & 'b'

D. Neither 'a' nor 'b'

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4

Normal temperature and pressure (N.T.P.) corresponds to

A. 0°C and 760 mm Hg

B. 15°C and 760 mm Hg

C. 20°C and 760 mm Hg

D. 0°C and 1 kgf/cm2

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4

Which of the following is an undesirable characteristic of a refrigerant?

A. It should be non-explosive

B. It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils

C. Its vapor pressure at the condenser temperature should be very high

D. None of these

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4

Claude gas liquefaction process employs cooling

A. At constant pressure

B. By throttling

C. By expansion in an engine

D. None of these

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4

What is the degree of freedom for a system comprising liquid water equilibrium with its vapour?

A. 0

B. 1

C. 2

D. 3

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4

Joule-Thomson experiment is

A. Isobaric

B. Adiabatic

C. Isenthalpic

D. Both (B) & (C)

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4

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

A. Isothermal

B. Adiabatic

C. Isobaric

D. Isochoric

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4

Van Laar equation deals with the activity coefficients in

A. Binary solutions

B. Ternary solutions

C. Azeotropic mixture only

D. None of these

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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

If the molar heat capacities (Cp or Cv) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will

A. Increase

B. Decrease

C. Remain unaltered

D. Increase or decrease; depends on the particular reaction

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4

Entropy change for an irreversible isolated system is

A.

B. 0

C. < 0

D. > 0