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4

If the internal energy of an ideal gas decreases by the same amount as the work done by the system, then the

A. Process must be isobaric

B. Temperature must decrease

C. Process must be adiabatic

D. Both (B) and (C)

Correct Answer :

D. Both (B) and (C)


Related Questions

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4

Pick out the wrong statement.

A. Activity co-efficient is dimensionless.

B. In case of an ideal gas, the fugacity is equal to its pressure.

C. In a mixture of ideal gases, the fugacity of a component is equal to the partial pressure of the component.

D. The fugacity co-efficient is zero for an ideal gas

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4

dW and dq are not the exact differential, because q and W are

A. State functions

B. Path functions

C. Intensive properties

D. Extensive properties

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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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A system is said to be isopiestic, if there is no __________ change.

A. Temperature

B. Pressure

C. Volume

D. None of these

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4

Compound having large heat of formation is

A. More stable

B. Less stable

C. Not at all stable (like nascent O2)

D. Either more or less stable; depends on the compound

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4

Which of the following has the least thermal efficiency?

A. Steam engine

B. Carnot engine

C. Diesel engine

D. Otto engine

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4

The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/RT) = A . x1. x2, where A is a constant. The corresponding equation for ln y1, where y1 is the activity co-efficient of component 1, is

A. A . x22

B. Ax1

C. Ax2

D. Ax12

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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

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

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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

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

A. Molecular size

B. Temperature

C. Volume

D. Pressure

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__________ Equation predicts the activity coefficient from experimental data.

A. Lewis-Randall

B. Margules

C. Van Laar

D. Both (B) & (C)

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4

Chemical engineering thermodynamics is concerned with the __________ in/of chemical processes.

A. Reaction mechanism

B. Calculation of rates

C. Energy transformation from one form to another

D. None of these

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Free energy, fugacity and activity co-efficient are all affected by change in the temperature. The fugacity co-efficient of a gas at constant pressure ____with the increase of reduced temperature.

A. Decreases

B. Increases

C. Remains constant

D. Decreases logarithmically

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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

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

In jet refrigerators, the refrigerating fluid is practically always

A. Water

B. Ammonia

C. Freon

D. Brine

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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

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4

Cv for an ideal gas

A. Does not depend upon temperature

B. Is independent of pressure only

C. Is independent of volume only

D. Is independent of both pressure and volume

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4

For a constant volume process __________ by the system is used only to increase the internal energy.

A. Heat absorbed

B. Work done

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

Which of the following is Clausius-Clapeyron Equation for vaporisation of an ideal gas under the condition that the molar volume of liquid is negligible compared to that of the vapor?

A. d ln p/dt = Hvap/RT2

B. d ln p/dt = RT2/Hvap

C. dp/dt = RT2/Hvap

D. dp/dt = Hvap/RT2

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4

The relation connecting the fugacities of various components in a solution with one another and to composition at constant temperature and pressure is called the __________ equation.

A. Gibbs-Duhem

B. Van Laar

C. Gibbs-Helmholtz

D. Margules

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4

Entropy of an ideal gas depends upon its

A. Pressure

B. Temperature

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

Fugacity is most helpful in

A. Representing actual behaviour of real gases

B. Representing actual behaviour of ideal gases

C. The study of chemical equilibria involving gases at atmospheric pressure

D. None of these

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4

The kinetic energy of gas molecule is zero at

A. 0°C

B. 273°C

C. 100°C

D. -273°C

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4

A system is said to be at equilibrium, if the entropy of the system has reached __________ value.

A. Minimum

B. Zero

C. Maximum

D. None of these

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4

In the equation, PVn = constant, if the value of n = ± ∞, then it represents a reversible __________ process.

A. Adiabatic

B. Isometric

C. Isentropic

D. Isothermal

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4

Any substance above its critical temperature exists as

A. Saturated vapour

B. Solid

C. Gas

D. Liquid

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Critical temperature is defined as the temperature above which a gas will

A. Not liquify (barring exceptions)

B. Immediately liquify

C. Never liquify however high the pressure may be

D. None of these

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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