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4

Specific/molar Gibbs free energy for a pure substance does not change during

A. Sublimation

B. Vaporisation

C. Melting

D. Either (A), (B) or (C)

Correct Answer :

D. Either (A), (B) or (C)


Related Questions

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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

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

A. Concentration

B. Mass

C. Temperature

D. Entropy

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4

First law of thermodynamics is mathematically stated as

A. dQ = dE + dW

B. dQ = dE - dW

C. dE = dQ + dW

D. dW = dQ + dE

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4

In an ideal solution, the activity of a component equals its

A. Mole fraction

B. Fugacity at the same temperature and pressure

C. Partial pressure

D. None of these

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4

Kopp's rule is used to calculate the heat capacity of

A. Solids

B. Liquids

C. Gases

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

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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

(∂T/∂P)H is the mathematical expression for

A. Specific heat at constant pressure (Cp)

B. Specific heat at constant volume (Cv)

C. Joule-Thompson co-efficient

D. None of these

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4

The expression, ΔG = nRT. ln(P2/P1), gives the free energy change

A. With pressure changes at constant temperature

B. Under reversible isothermal volume change

C. During heating of an ideal gas

D. During cooling of an ideal gas

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4

Joule-Thomson co-efficient depends on the

A. Pressure

B. Temperature

C. Both (A) & (B)

D. Neither (A) nor (B)

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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

Efficiency of a Carnot engine working between temperatures T1 and T2 (T1 < T) is

A. (T2 - T1)/T2

B. (T2 - T1)/T1

C. (T1 - T2)/T2

D. (T1 - T2)/T1

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4

Measurement of thermodynamic property of temperature is facilitated by __________ law of thermodynamics.

A. 1st

B. Zeroth

C. 3rd

D. None of these

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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

The absolute entropy for all crystalline substances at absolute zero temperature is

A. Zero

B. Negative

C. More than zero

D. Indeterminate

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4

Gibbs phase rule finds application, when heat transfer occurs by

A. Conduction

B. Convection

C. Radiation

D. Condensation

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4

The equation, Cp - Cv = R, is true for __________ gas.

A. No

B. Any real

C. Only ideal

D. Both (B) and (C)

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4

Critical solution temperature (or the consolute temperature) for partially miscible liquids (e.g., phenol-water) is the minimum temperature at which

A. A homogeneous solution (say of phenol water) is formed

B. Mutual solubility of the two liquids shows a decreasing trend

C. Two liquids are completely separated into two layers

D. None of these

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4

Grams of butane (C4H10) formed by the liquefaction of 448 litres of the gas (measured at (STP) would be

A. 580

B. 640

C. 1160

D. Data insufficient; can't be computed

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4

A refrigerator works on the principle of __________ law of thermodynamics.

A. Zeroth

B. First

C. Second

D. Third

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4

Pick out the correct statement.

A. Compression ratio of an Otto engine is comparatively higher than a diesel engine

B. Efficiency of an Otto engine is higher than that of a diesel engine for the same compression ratio

C. Otto engine efficiency decreases with the rise in compression ratio, due to decrease in work produced per quantity of heat

D. Diesel engine normally operates at lower compression ratio than an Otto engine for an equal output of work

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4

The heat capacities for the ideal gas state depend upon the

A. Pressure

B. Temperature

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

Entropy is a/an

A. State function

B. Macroscopic property

C. Extensive property

D. None of these

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4

Heat is added at constant temperature in an ideal __________ cycle.

A. Stirling

B. Brayton

C. Rankine

D. None of these

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4

For any system, what is the minimum number of degrees of freedom?

A. 0

B. 1

C. 2

D. 3

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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 case of steady flow compression polytropic process (PVn = constant), the work done on air is the lowest, when

A. n = y = 1.4

B. n = 0

C. n = 1

D. n = 1.66

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4

When pressure is applied on the system, ice ↔ water, then

A. Equilibrium cannot be established

B. More ice will be formed

C. More water will be formed

D. Evaporation of water will take place

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4

The ratio of equilibrium constants (Kp2/Kp1) at two different temperatures is given by

A. (R/ΔH) (1/T1 - 1/T2)

B. (ΔH/R) (1/T1 - 1/T2)

C. (ΔH/R) (1/T2 - 1/T1)

D. (1/R) (1/T1 - 1/T2)

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4

Which of the following is Virial equation of state?

A. (p + a/V2)(V - b) = nRT

B. PV = nRT

C. PV = A + B/V + C/V2 + D/V3 + ...

D. None of these

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4

An ideal gas is taken around the cycle ABCA as shown in P-V diagram below: The work done by the gas during the cycle is equal to

A. 12 P1V1

B. 6 P1 V1

C. 3 P1V1

D. P1 V1