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What is the correct answer?

4

Gibbs free energy of mixing at constant pressure and temperature is always

A. 0

B.

C. + ve

D. - ve

Correct Answer :

D. - ve


Related Questions

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4

The partial pressure of each constituent present in an alloy is __________ the total vapor pressure exerted by the alloy.

A. Less than

B. Equal to

C. More than

D. Either (B) or (C); depends on the type of alloy

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4

Which of the following liquid metals has the highest thermal conductivity?

A. Molten sodium

B. Molten lead

C. Mercury

D. Molten potassium

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4

Gibbs-Duhem equation

A. States that n11 + n22 + ....njj = 0, for a system of definite composition at constant temperature and pressure

B. Applies only to binary systems

C. Finds no application in gas-liquid equilibria involved in distillation

D. None of these

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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

Refrigeration cycle

A. Violates second law of thermodynamics

B. Involves transfer of heat from low temperature to high temperature

C. Both (A) and (B)

D. Neither (A) nor (B)

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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

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4

Pick out the wrong statement.

A. At constant pressure, solubility of a gas in a liquid diminishes with rise in temperature

B. Normally, the gases which are easily liquefied are more soluble in common solvents

C. The gases which are capable of forming ions in aqueous solution are much more soluble in water than in other solvents

D. At constant pressure, solubility of a gas in a liquid increases with rise in temperature

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4

In the equation, PVn = constant, if the value of n = 1, then it represents a reversible __________ process.

A. Isothermal

B. Isobaric

C. Polytropic

D. Adiabatic

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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

Pick out the undesirable property for a good refrigerant.

A. High thermal conductivity

B. Low freezing point

C. Large latent heat of vaporisation

D. High viscosity

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4

Partial molar free energy of an element A in solution is same as its

A. Chemical potential

B. Activity

C. Fugacity

D. Activity co-efficient

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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

Dryness fraction of wet steam is defined as the ratio of mass of vapour in the mixture to the mass of mixture __________ calorimeter is not used for measuring the dryness fraction of steam.

A. Bomb

B. Separating

C. Bucket

D. Throttling

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4

(∂E/∂T)V is the mathematical expression for

A. CV

B. Enthalpy change

C. Free energy change

D. None of these

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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

Gibbs free energy per mole for a pure substance is equal to the

A. Latent heat of vaporisation

B. Chemical potential

C. Molal boiling point

D. Heat capacity

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4

Pick out the wrong statement.

A. Enthalpies of all elements in their standard states are assumed to be zero

B. Combustion reactions are never endothermic in nature

C. Heat of reaction at constant volume is equal to the change in internal energy

D. Clausius-Clapeyron equation is not applicable to melting process

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4

Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of

A. Solution

B. Vaporisation

C. Formation

D. Sublimation

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4

In the reaction, H2 +I2 2HI, addition of an inert gas will

A. Increase the partial pressure of H2

B. Increase the partial pressure of I2

C. Increase the total pressure and hence shift the equilibrium towards the right

D. Not affect the equilibrium conditions

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4

Joule-Thomson Co-efficient at any point on the inversion curve is

A.

B. +ve

C. 0

D. -ve

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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

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

Melting of ice is an example of an __________ process.

A. Adiabatic

B. Isothermal

C. Isometric

D. None of these

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4

In case of a reversible process (following pvn = constant), work obtained for trebling the volume (v1 = 1 m3 and v23 m3) is maximum, when the value of 'n' is

A. 0

B. 1

C. y = 1.44

D. 1.66

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4

Which of the following is a thermodynamic property of a system?

A. Concentration

B. Mass

C. Temperature

D. Entropy

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4

Pick out the wrong statement.

A. Surface tension of a substance vanishes at critical point, as there is no distinction between liquid and vapour phases at its critical point

B. Entropy of a system decreases with the evolution of heat

C. Change of internal energy is negative for exothermic reactions

D. The eccentric factor for all materials is always more than one

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4

Entropy change for an irreversible process taking system and surrounding together is

A. 0

B. > 0

C. < 0

D. None of these

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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

Which one is true for a throttling process?

A. A gas may have more than one inversion temperatures

B. The inversion temperature is different for different gases

C. The inversion temperature is same for all gases

D. The inversion temperature is the temperature at which Joule-Thomson co-efficient is infinity

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4

Which of the following diagrams does not represent an Otto cycle?

A.

B.

C.

D. None of these