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4

Which of the following is not a common refrigerant?

A. Freon-12

B. Ethylene

C. Ammonia

D. Carbon dioxide

Correct Answer :

B. Ethylene


Related Questions

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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

A domestic refrigerator has a/an __________ cooled condenser.

A. Water

B. Air

C. Evaporative

D. Gas

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4

A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, Δ S1 and Δ SR are the entropy changes of the system for the irreversible and reversible processes respectively)

A. Δ S1 is always < Δ SR

B. Δ S1 is sometimes > Δ SR

C. Δ S1 is always > Δ SR

D. Δ S1 is always = Δ SR

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4

An isentropic process is carried out at constant

A. Volume

B. Pressure

C. Temperature

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

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4

Air enters an adiabatic compressor at 300K. The exit temperature for a compression ratio of 3, assuming air to be an ideal gas (Y = Cp/Cv = 7/5) and the process to be reversible, is

A. 300 × (32/7)

B. 300 × (33/5)

C. 300 × (333/7)

D. 300 × (35/7)

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4

At a given temperature, the volume of a gas dissolved in a solvent __________ with increase in pressure.

A. Increases

B. Decreases

C. Remains unchanged

D. May increase or decrease; depends on the gas

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4

Pick out the wrong statement.

A. The chemical potential of a pure substance depends upon the temperature and pressure

B. The chemical potential of a component in a system is directly proportional to the escaping tendency of that component

C. The chemical potential of ith species (μi) in an ideal gas mixture approaches zero as the pressure or mole fraction (xi) tends to be zero at constant temperature

D. The chemical potential of species 'i' in the mixture (μi) is mathematically represented as,μi = ∂(nG)/∂ni]T,P,nj where, n, ni and nj respectively denote the total number of moles, moles of ith species and all mole numbers except ith species. 'G' is Gibbs molar free energy

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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

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

For a constant pressure reversible process, the enthalpy change (ΔH) of the system is

A. Cv.dT

B. Cp.dT

C. ∫ Cp.dT

D. ∫ Cv.dT

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4

Heating of water under atmospheric pressure is an __________ process.

A. Isochoric

B. Isobaric

C. Adiabatic

D. Isothermal

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4

High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process:

A. Δ H = 0 and ΔS = 0

B. Δ H ≠ 0 and ΔS = 0

C. Δ H ≠ 0 and ΔS ≠ 0

D. Δ H = 0 and ΔS ≠ 0

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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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Third law of thermodynamics is concerned with the

A. Value of absolute entropy

B. Energy transfer

C. Direction of energy transfer

D. None of these

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4

The Maxwell relation derived from the differential expression for the Helmholtz free energy (dA) is

A. (∂T/∂V)S = - (∂P/∂S)V

B. (∂S/∂P)T = - (∂V/∂T)P

C. (∂V/∂S)P = (∂T/∂P)S

D. (∂S/∂V)T = (∂P/∂T)V

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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)

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4

Which of the following is not an intensive property?

A. Molar heat capacity

B. Internal energy

C. Viscosity

D. None of these

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4

Entropy change of mixing two liquid substances depends upon the

A. Molar concentration

B. Quantity (i.e. number of moles)

C. Both (A) and (B)

D. Neither (A) nor (B)

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4

For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases.

A. Chemical potential

B. Fugacity

C. Both (A) and (B)

D. Neither (A) nor (B)

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4

For a spontaneous process, free energy

A. Is zero

B. Increases

C. Decreases whereas the entropy increases

D. And entropy both decrease

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4

The equation Tds = dE - PdV applies to

A. Single phase fluid of varying composition

B. Single phase fluid of constant composition

C. Open as well as closed systems

D. Both (B) and (C)

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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

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4

In any spontaneous process, the __________ free energy decreases.

A. Helmholtz

B. Gibbs

C. Both a & b

D. Neither 'a' nor 'b'

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4

Work done in an adiabatic process between two states depends on the

A. Rate of heat transmission

B. Initial state only

C. End states only

D. None of these

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4

The intensive properties are

A. Molar volume, density, viscosity and boiling point

B. Refractive index and surface tension

C. Both (A) and (B)

D. None of these

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4

Standard temperature and pressure (S.T.P.) is

A. 0°C and 750 mm Hg

B. 15°C and 750 mm Hg

C. 0°C and 1 kgf/cm2

D. 15°C and 1 kgf/cm2

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4

Gibbs-Duhem equation relates composition in liquid phase and the __________ at constant temperature & pressure.

A. Fugacity

B. Partial pressure

C. Activity co-efficient

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

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4

Entropy, which is a measure of the disorder of a system, is:

A. Independent of pressure

B. Independent of temperature

C. Zero at absolute zero temperature for a perfect crystalline substance

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

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4

At constant temperature and pressure, for one mole of a pure substance, the ratio of the free energy to the chemical potential is

A. Zero

B. One

C. Infinity

D. Negative

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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