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4

Pick out the wrong statement

A. Phase rule variables are intensive properties

B. Heat and work are both state function

C. The work done by expansion of a gas in vacuum is zero

D. CP and CV are state function

Correct Answer :

B. Heat and work are both state function


Related Questions

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Which of the following is affected by the temperature?

A. Fugacity

B. Activity co-efficient

C. Free energy

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

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4

Trouton's ratio is given by (where λb, = molal heat of vaporisation of a substance at its normal boiling point, kcal/kmol Tb = normal boiling point, °K)

A. λb/Tb

B. Tb/λb

C. √(λb/Tb)

D. √(Tb/λb)

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4

Which is not a refrigerant?

A. SO2

B. NH3

C. CCl2F2

D. C2H4Cl2

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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

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

Domestic refrigerator usually works on the __________ refrigeration cycle.

A. Carnot

B. Air

C. Absorption

D. vapour-ejection

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4

It is desired to bring about a certain change in the state of a system by performing work on the system under adiabatic conditions.

A. The amount of work needed is path dependent

B. Work alone cannot bring out such a change of state

C. The amount of work needed is independent of path

D. More information is needed to conclude anything about the path dependence or otherwise of the work needed

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4

The adiabatic throttling process of a perfect gas is one of constant enthalpy

A. In which there is a temperature drop

B. Which is exemplified by a non-steady flow expansion

C. Which can be performed in a pipe with a constriction

D. In which there is an increase in temperature

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4

Requisites of a reversible process is that the

A. System and surroundings pressure be equal

B. Friction in the system should be absent

C. System and surroundings temperature be equal

D. None of these

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4

Number of degrees of freedom for a three phase system in equilibrium comprising of three nonreacting chemical species is

A. 2

B. 0

C. 1

D. 3

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4

Which of the following behaves most closely like an ideal gas?

A. He

B. N2

C. O2

D. H2

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4

A change in state involving a decrease in entropy can be spontaneous, only if

A. It is exothermic

B. It is isenthalpic

C. It takes place isothermally

D. It takes place at constant volume

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4

Fugacity of a component in an ideal gas mixture is equal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at constant pressure and temperature __________ as its mole fraction increases.

A. Decreases

B. Decreases exponentially

C. Increases

D. Remain constant

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4

Clausius-Clapeyron Equation gives accurate result, when the

A. Vapour pressure is relatively low and the temperature does not vary over wide limits

B. Vapour obeys the ideal gas law and the latent heat of vaporisation is constant

C. Volume in the liquid state is negligible compared with that in the vapour state

D. All (A), (B) and (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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A/an __________ system is exemplified by a vessel containing a volatile liquid in contact with its vapor.

A. Isolated

B. Closed

C. Open

D. None of these

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4

Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of

A. Sublimation

B. Fusion

C. Transition

D. Vaporisation

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4

The activity of an ideal gas is numerically __________ its pressure.

A. More than

B. Less than

C. Equal to

D. Data insufficient, can't be predicted

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4

The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances. This is the

A. Lewis-Randall rule

B. Statement of Van't Hoff Equation

C. Le-Chatelier's principle

D. None of these

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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

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

Which of the following is not a common refrigerant?

A. Freon-12

B. Ethylene

C. Ammonia

D. Carbon dioxide

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4

Equilibrium constant decreases as the temperature

A. Increases, for an exothermic reaction

B. Decreases, for an exothermic reaction

C. Increases, for an endothermic reaction

D. None of these

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4

The number of degree of freedom for an Azeotropic mixture of ethanol and water in vapourliquid equilibrium, is

A. 3

B. 1

C. 2

D. 0

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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

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

A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg-1. K-1. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg-1, K-1 is

A. -1.87

B. 0

C. 1.26

D. 3.91

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4

The enthalpy change when ammonia gas is dissolved in water is called the heat of

A. Solution

B. Formation

C. Dilution

D. Combustion

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__________ 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

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4

A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to the __________ mean of P1 and P2. (where, P1 and P2 are initial and final pressures respectively)

A. Logarithmic

B. Arithmetic

C. Geometric

D. Harmonic