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4

There is a change in __________ during the phase transition.

A. Volume

B. Pressure

C. Temperature

D. All a, b & c

Correct Answer :

A. Volume


Related Questions

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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

Entropy is a measure of the __________ of a system.

A. Disorder

B. Orderly behaviour

C. Temperature changes only

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

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

When a system is in equilibrium for all possible processes, the differential or finite change of entropy is

A. < 0

B. > 0

C. = 0

D. None of these

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4

Which of the following has the minimum value of COP for a given refrigeration effect?

A. Reverse Carnot cycle

B. Ordinary vapour-compression cycle

C. Vapour-compression process with a reversible expansion engine

D. Air refrigeration cycle

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4

Trouton's ratio of __________ liquids is calculated using Kistyakowsky equation.

A. Polar

B. Non-polar

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

High __________ is an undesirable property for a good refrigerant.

A. Specific heat

B. Latent heat of vaporisation

C. Viscosity

D. Specific vapor volume

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4

Entropy of a substance remains constant during a/an __________ change.

A. Reversible isothermal

B. Irreversible isothermal

C. Reversible adiabatic

D. None of these

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4

Co-efficient of performance for a reversed Carnot cycle working between temperatures T1 and T2 (T1 > T2) is

A. T2/(T1 - T2)

B. T1/(T1 - T2)

C. (T1 - T2)/T1

D. (T1 - T2)/T2

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4

Forward reaction will be favoured for the exothermic reaction, represented by CO + H2O CO2 + H2, by

A. Low temperature and high pressure

B. Low temperature and low pressure

C. High temperature and high pressure

D. High temperature and low pressure

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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 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

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 an extensive property of a system?

A. Heat capacity

B. Molal heat capacity

C. Pressure

D. Concentration

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4

For an ideal solution, the value of activity co-efficient is

A. 0

B. 1

C. < 1

D. > 1

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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

Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. °K

A. 0

B.

C. 50

D. 100

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4

A solid is transformed into vapour without going to the liquid phase at

A. Triple point

B. Boiling point

C. Below triple point

D. Always

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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

Clapeyron Equation deals with the

A. Rate of change of vapour pressure with temperature

B. Effect of an inert gas on vapour pressure

C. Calculation of ΔF for spontaneous phase change

D. Temperature dependence of heat of phase transition

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4

Joule-Thomson effect i.e., a throttling process is a constant __________ process.

A. Entropy

B. Temperature

C. Internal energy

D. Enthalpy

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4

Joule-Thomson co-efficient for a perfect gas is

A. Zero

B. Positive

C. Negative

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

(∂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

At the critical point of a substance

A. The surface tension vanishes

B. Liquid and vapour have the same density

C. There is no distinction between liquid and vapour phases

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

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4

In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process.

A. Isometric

B. Polytropic

C. Isentropic

D. Isobaric

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4

In an ideal gas mixture, fugacity of a species is equal to its

A. Vapor pressure

B. Partial pressure

C. Chemical potential

D. None of these

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4

The main feature of Carnot refrigeration cycle is that, it

A. Does not need the addition of external work for its functioning

B. Transfers heat from high temperature to low temperature

C. Accomplishes the reverse effect of the heat engine

D. None of these

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4

Compressibility factor of a gas is

A. Not a function of its pressure

B. Not a function of its nature

C. Not a function of its temperature

D. Unity, if it follows PV = nRT