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4

What is the value of ln y (where y = activity co-efficient) for ideal gases?

A. Zero

B. Unity

C. Infinity

D. Negative

Correct Answer :

A. Zero


Related Questions

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4

Free energy changes for two reaction mechanism 'X' and 'Y are respectively - 15 and - 5 units. It implies that X is

A. Slower than Y

B. Faster than Y

C. Three times slower than Y

D. Three times faster than Y

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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

Law of corresponding states says that

A. Two different gases behave similarly, if their reduced properties (i.e. P, V and T) are same

B. The surface of separation (i. e. the meniscus) between liquid and vapour phase disappears at the critical temperature

C. No gas can be liquefied above the critical temperature, howsoever high the pressure may be.

D. The molar heat of energy of gas at constant volume should be nearly constant (about 3 calories)

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4

__________ explains the equilibrium constant for any chemical reaction.

A. Henry's law

B. Law of mass action

C. Hess's law

D. None of these

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4

The most important application of distribution law is in

A. Evaporation

B. Liquid extraction

C. Drying

D. Distillation

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4

Second law of thermodynamics is concerned with the

A. Amount of energy transferred

B. Direction of energy transfer

C. Irreversible processes only

D. Non-cyclic processes only

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4

The quantitative effect of temperature on chemical equilibrium is given by the

A. Vant-Hoff equation

B. Le-Chatelier's principle

C. Arrhenius equation

D. None of these

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4

Cp of a gas at its critical temperature and pressure

A. Becomes zero

B. Becomes infinity

C. Equals 1 kcal/kmol °K

D. Equals 0.24 kcal/kmol °K

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4

When dilute aqueous solutions of two salts are mixed, the process is associated with

A. Decrease in temperature

B. Increase in temperature

C. No change in temperature

D. Change in temperature which is a function of composition

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4

The unit of equilibrium constant of a chemical reaction is the same as that of

A. Molar concentration

B. Temperature

C. Internal energy

D. None of these

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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

The number of degrees of freedom for an azeotropic mixture in a two component vapour-liquid equilibria is/are

A. Zero

B. One

C. Two

D. Three

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4

Henry's law is closely obeyed by a gas, when its __________ is extremely high.

A. Pressure

B. Solubility

C. Temperature

D. None of these

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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

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4

What happens in a reversible adiabatic expansion process?

A. Heating takes place

B. Cooling takes place

C. Pressure is constant

D. Temperature is constant

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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

dW and dq are not the exact differential, because q and W are

A. State functions

B. Path functions

C. Intensive properties

D. Extensive properties

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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

Refrigerants commonly used for domestic refrigerators are

A. Ethyl chloride or methyl chloride

B. Freon-12

C. Propane

D. NH3 or CO2

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4

Throttling process is a/an __________ process.

A. Reversible and isothermal

B. Irreversible and constant enthalpy

C. Reversible and constant entropy

D. Reversible and constant enthalpy

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4

Specific heat of a gas for a reversible adiabatic process is

A. Negative

B. Zero

C. Infinity

D. None of these

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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

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

Out of the following refrigeration cycles, which one has maximum COP?

A. Air cycle

B. Carnot cycle

C. Ordinary vapor compression cycle

D. Vapor compression with a reversible expansion engine

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4

Efficiency of a heat engine working on Carnot cycle between two temperature levels depends upon the

A. Two temperatures only

B. Pressure of working fluid

C. Mass of the working fluid

D. Mass and pressure both of the working fluid

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4

The enthalpy change when ammonia gas is dissolved in water is called the heat of

A. Solution

B. Formation

C. Dilution

D. Combustion

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4

Gibbs free energy (F) is defined as

A. F = E - TS

B. F = H - TS

C. F = H + TS

D. F = E + TS

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4

Fugacity is a measure of the

A. Escaping tendencies of the same substance in different phases of a system

B. Relative volatility of a mixture of two miscible liquids

C. Behaviour of ideal gases

D. None of these

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4

As the temperature is lowered towards the absolute zero, the value of the quantity (∂ΔF/∂T) approaches

A. Zero

B. Unity

C. Infinity

D. None of these

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4

A refrigeration cycle is the same as a __________ cycle,

A. Turbine

B. Heat engine

C. Reversed heat engine

D. None of these