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4

The value of Cp & Cv respectively for monatomic gases in Kcal/kg Mole.°K are

A. 5 & 3

B. 3.987 & 1.987

C. 1.987 & 0.66

D. 0.66 & 1.987

Correct Answer :

A. 5 & 3


Related Questions

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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

A reasonably general expression for vapourliquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of

A. Temperature only

B. Temperature and pressure only

C. Temperature, pressure and liquid composition xi only

D. Temperature, pressure, liquid composition xi and vapour composition yi

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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

A cylinder contains 640 gm of liquid oxygen. The volume occupied (in litres) by the oxygen, when it is released and brought to standard conditions (0°C, 760 mm Hg) will be __________ litres.

A. 448

B. 224

C. 22.4

D. Data insufficient; can't be computed

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4

In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in

A. Enhanced COP

B. Decreased COP

C. No change in the value of COP

D. Increased or decreased COP; depending upon the type of refrigerant

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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

A change in state involving a decrease in entropy can be spontaneous, only if

A. It is exothermic

B. It is isenthalpic

C. It takes place isothermally

D. It takes place at constant volume

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4

The equation DU = Tds - PdV is applicable to infinitesimal changes occuring in

A. An open system of constant composition

B. A closed system of constant composition

C. An open system with changes in composition

D. A closed system with changes in composition

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4

Which of the following has the least thermal efficiency?

A. Steam engine

B. Carnot engine

C. Diesel engine

D. Otto engine

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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

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

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4

In case of the decomposition of hydroiodic acid (2HI H2 + I2), addition of H2 (at equilibrium condition) will

A. Increase the partial pressure of I2

B. Decrease the partial pressure of HI

C. Diminish the degree of dissociation of HI

D. None of these

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4

The expression, nRT ln(P1/P2), is for the __________of an ideal gas.

A. Compressibility

B. Work done under adiabatic condition

C. Work done under isothermal condition

D. Co-efficient of thermal expansion

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4

The activity of an ideal gas is numerically __________ its pressure.

A. More than

B. Less than

C. Equal to

D. Data insufficient, can't be predicted

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4

Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.).

A. Entropy

B. Internal energy

C. Enthalpy

D. Gibbs free energy

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4

Number of degrees of freedom for a three phase system in equilibrium comprising of three nonreacting chemical species is

A. 2

B. 0

C. 1

D. 3

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4

The expression, ΔG = nRT. ln(P2/P1), gives the free energy change

A. With pressure changes at constant temperature

B. Under reversible isothermal volume change

C. During heating of an ideal gas

D. During cooling of an ideal gas

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4

The energy of activation of exothermic reaction is

A. Zero

B. Negative

C. Very large compared to that for endothermic reaction

D. Not possible to predict

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4

While dissolving a gas into a liquid at a constant temperature, the ratio of the concentration of the gas in the solution phase and in the gaseous phase is

A. Infinity

B. Unity

C. Constant

D. Negative

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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

Consider the reaction, C + O2 CO2; ΔH = - 94 kcal. What will be the value of ΔH for the reaction CO2 → C + O2?

A. -94 kcal

B. +94 kcal

C. > 94 kcal

D. < -94 kcal

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4

Enthalpy 'H' is defined as

A. H = E - PV

B. H = F - TS

C. H - E = PV

D. None of these

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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

y = specific heat ratio of an ideal gas is equal to

A. Cp/Cv

B. Cp/(CP-R)

C. 1 + (R/CV)

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

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4

During adiabatic expansion of gas

A. Pressure remains constant

B. Pressure is increased

C. Temperature remains constant

D. None of these

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4

For a single component two phase mixture, the number of independent variable properties are

A. Two

B. One

C. Zero

D. Three

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4

A solute distributes itself between two nonmiscible solvents in contact with each other in such a way that, at a constant temperature, the ratio of its concentrations in two layers is constant, irrespective of its total amount. This is

A. The distribution law

B. Followed from Margules equation

C. A corollary of Henry's law

D. None of these

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4

Pick out the correct statement.

A. Compression ratio of an Otto engine is comparatively higher than a diesel engine

B. Efficiency of an Otto engine is higher than that of a diesel engine for the same compression ratio

C. Otto engine efficiency decreases with the rise in compression ratio, due to decrease in work produced per quantity of heat

D. Diesel engine normally operates at lower compression ratio than an Otto engine for an equal output of work

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4

Which one is true for a throttling process?

A. A gas may have more than one inversion temperatures

B. The inversion temperature is different for different gases

C. The inversion temperature is same for all gases

D. The inversion temperature is the temperature at which Joule-Thomson co-efficient is infinity

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4

In a homogeneous solution, the fugacity of a component depends upon the

A. Pressure

B. Composition

C. Temperature

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