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4

Linde gas liquefaction process employs cooling

A. By throttling

B. By expansion in an engine

C. At constant pressure

D. None of these

Correct Answer :

A. By throttling


Related Questions

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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

With increase in temperature, the internal energy of a substance

A. Increases

B. Decreases

C. Remains unchanged

D. May increase or decrease; depends on the substance

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4

In jet refrigerators, the refrigerating fluid is practically always

A. Water

B. Ammonia

C. Freon

D. Brine

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4

One ton of refrigeration is defined as the heat rate corresponding to melting of one ton of ice in one

A. Hour

B. Day

C. Minute

D. Second

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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

When a gas in a vessel expands, its internal energy decreases. The process involved is

A. Reversible

B. Irreversible

C. Isothermal

D. Adiabatic

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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

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

Which is a state function?

A. Specific volume

B. Work

C. Pressure

D. Temperature

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4

In the equation, PVn = Constant, if the value of n = 0, then it represents a reversible __________ process.

A. Isobaric

B. Isothermal

C. Isentropic

D. Isometric

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4

__________ 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

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

The amount of heat required to decompose a compound into its elements is __________ the heat of formation of that compound from its elements.

A. Less than

B. More than

C. Same as

D. Not related to

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4

Air-refrigeration cycle

A. Is the most efficient of all refrigeration cycles

B. Has very low efficiency

C. Requires relatively large quantities of air to achieve a significant amount of refrigeration

D. Both (B) and (C)

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4

In a reversible chemical reaction (where, Δx = number of moles of products-number of moles of reactants)

A. Addition of inert gas favours the forward reaction, when Δx is positive

B. Pressure has no effect on equilibrium, when Δn = 0

C. Addition of inert gas has no effect on the equilibrium constant at constant volume for any value of Δx (+ ve, - ve) or zero)

D. All 'a', 'b' & 'c'

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4

For a given substance at a specified temperature, activity is __________ to fugacity.

A. Directly proportional

B. Inversely proportional

C. Equal

D. None of these

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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 effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is

A. Less pronounced

B. More pronounced

C. Equal

D. Data insufficient, can't be predicted

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4

Entropy change for an irreversible isolated system is

A.

B. 0

C. < 0

D. > 0

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4

For spontaneous changes in an isolated system (S = entropy)

A. ds = 0

B. ds <0

C. ds > 0

D. ds = Constant

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4

The second law of thermodynamics states that

A. The energy change of a system undergoing any reversible process is zero

B. It is not possible to transfer heat from a lower temperature to a higher temperature

C. The total energy of system and surrounding remains the same

D. None of the above

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4

During the phase transition, __________ changes.

A. Pressure

B. Volume

C. Temperature

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

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4

The standard state of a gas (at a given temperature) is the state in which fugacity is equal to

A. Unity

B. Activity

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

The expression for entropy change given by, ΔS = - nR ln (P2/P1), holds good for

A. Expansion of a real gas

B. Reversible isothermal volume change

C. Heating of an ideal gas

D. Cooling of a real gas

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4

4 kg moles of an ideal gas expands in vacuum spontaneously. The work done is

A. 4 J

B.

C. 0

D. 8 J

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4

Pick out the correct statement.

A. If an insoluble gas is passed through a volatile liquid placed in a perfectly insulated container, the temperature of the liquid will increase

B. A process is irreversible as long as Δ S for the system is greater than zero

C. The mechanical work done by a system is always equal to∫P.dV

D. The heat of formation of a compound is defined as the heat of reaction leading to the formation of the compound from its reactants

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4

An ideal liquid refrigerant should

A. Not have a sub-atmospheric vapour pressure at the temperature in the refrigerator coils

B. Not have unduly high vapour pressure at the condenser temperature

C. Both (A) and (B)

D. Have low specific heat

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4

Fugacity and pressure are numerically equal, when the gas is

A. In standard state

B. At high pressure

C. At low temperature

D. In ideal state

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4

The freezing point of a liquid decreases when the pressure is increased, if the liquid __________ while freezing.

A. Contracts

B. Expands

C. Does not change in volume

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

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4

If the molar heat capacities (Cp or Cv) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will

A. Increase

B. Decrease

C. Remain unaltered

D. Increase or decrease; depends on the particular reaction