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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

Correct Answer :

D. High T, low P


Related Questions

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At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole fractions of methanol are 0.1686 and 0.5714 respectively. Activity co-efficient of methanol is

A. 1.572

B. 1.9398

C. 3.389

D. 4.238

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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

Third law of thermodynamics is helpful in

A. Prediction of the extent of a chemical reaction

B. Calculating absolute entropies of substances at different temperature

C. Evaluating entropy changes of chemical reaction

D. Both (B) and (C)

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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

Pick out the wrong statement.

A. A refrigeration cycle violates the second law of thermodynamics

B. Refrigeration cycle is normally represented by a temperature vs. entropy plot

C. In a refrigerator, work required decreases as the temperature of the refrigerator and the temperature at which heat is rejected increases

D. One ton of refrigeration is equivalent to the rate of heat absorption equal to 3.53 kW

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4

COP of a refrigerator drawing 1 kW of power per ton of refrigeration is about

A. 0.5

B. 3.5

C. 4.5

D. 8.5

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4

Two substances are in equilibrium in a reversible chemical reaction. If the concentration of each substance is doubled, then the value of the equilibrium constant will be

A. Same

B. Doubled

C. Halved

D. One fourth of its original value

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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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PVγ = Constant (where, γ = Cp/Cv) is valid for a/an __________ process.

A. Isothermal

B. Isentropic

C. Isobaric

D. Adiabatic

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4

Lenz's law results from the law of conservation of

A. Mass

B. Momentum

C. Energy

D. None of these

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4

Which is an example of closed system?

A. Air compressor

B. Liquid cooling system of an automobile

C. Boiler

D. None of these

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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

First law of thermodynamics deals with the

A. Direction of energy transfer

B. Reversible processes only

C. Irreversible processes only

D. None of these

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4

When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is

A. More in vapour phase

B. More in liquid phase

C. Same in both the phases

D. Replaced by chemical potential which is more in vapour phase

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4

Melting of ice is an example of an __________ process.

A. Adiabatic

B. Isothermal

C. Isometric

D. None of these

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4

Choose the condition that must be specified in order to liquify CO2 (triple point for CO2 is - 57°C and 5.2 atm).

A. Pressure must be kept below 5.2 atm

B. Temperature must be kept above - 57°C

C. Pressure must be kept below 5.2 atm. and temperature must be kept above 57°C

D. Pressure and temperature must be kept below 5.2 atm. and - 57°C respectively

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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

Heat of formation of an element in its standard state is

A. 0

B. < 0

C. > 0

D. A function of pressure

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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)

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4

Domestic refrigerator usually works on the __________ refrigeration cycle.

A. Carnot

B. Air

C. Absorption

D. vapour-ejection

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4

When a system in equilibrium is subjected to a change in temperature, pressure or concentration, the equilibrium is displaced in a direction which tends to undo the effect of the change. This is called the

A. Le-Chatelier principle

B. Kopp's rule

C. Law of corresponding state

D. Arrhenius hypothesis

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4

As the entropy of the universe is increasing, day by day, the work producing capacity of a heat engine is

A. Not changed

B. Decreasing

C. Increasing

D. Data sufficient, can't be predicted

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4

Melting of ice exemplifies a/an

A. Adiabatic process

B. Endothermic reaction

C. Exothermic reaction

D. Process involving a chemical reaction

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4

If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as

A. Solubility increases as temperature increases

B. Solubility increases as temperature decreases

C. Solubility is independent of temperature

D. Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution

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4

Clausius-Clapeyron equation is applicable to __________ equilibrium processes.

A. Solid-vapor

B. Solid-liquid

C. Liquid-vapor

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

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4

What happens in a reversible adiabatic compression?

A. Heating occurs

B. Cooling occurs

C. Pressure is constant

D. Temperature is constant

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4

Heat requirement for decomposition of a compound into its elements is __________ that is evolved during the formation of that compound from its elements.

A. The same

B. Less than

C. Greater than

D. Different than

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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

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4

The co-efficient of performance (COP) of a refrigerating system, which is its index of performance, is defined as the ratio of useful refrigeration to the net work. The units of __________ and COP are the same.

A. Kinematic viscosity

B. Work

C. Temperature

D. None of these

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4

The necessary and sufficient condition for equilibrium between two phases is

A. The concentration of each component should be same in the two phases

B. The temperature of each phase should be same

C. The pressure should be same in the two phases

D. The chemical potential of each component should be same in the two phases