Thermodynamics for Chemical Quiz 7

1 / 50

Sound waves propagation in air exemplifies an _______ process?

Isometric

Isothermal

None of these

Adiabatic

2 / 50

Pick out the correct statement?

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

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

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

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

3 / 50

Specific ______ does not change during phase change at constant temperature and pressure?

Internal energy

Gibbs energy

Entropy

Enthalpy

4 / 50

Solid and liquid phases of a substance are in equilibrium at the______?

Critical temperature

Melting point

Both B. and C

Freezing point

5 / 50

The absolute entropy for all crystalline substances at absolute zero temperature is ______?

Indeterminate

Zero

More than zero

Negative

6 / 50

Pick out the wrong statement?

Trouton?s ratio of non-polar liquids is calculated using Kistyakowsky equation

None of these

An equation relating pressure, volume and temperature of a gas is called ideal gas equation

Thermal efficiency of a Carnot engine is always less than 1

7 / 50

Pick out the wrong statement?

Systems, in which the mutual solubility increases with decrease in temperature, are said to possess lower consolute temperature

None of these

Nicotine-water system shows both an upper as well as a lower consolute temperature, implying that they are partially miscible between these two limiting temperatures

System (of partially miscible liquid pairs), in which the mutual solubility increases with rise in temperature, are said to possess an upper consolute temperature

8 / 50

The activity of an ideal gas is numerically _____ its pressure?

Less than

Data insufficient, can?t be predicted

Equal to

More than

9 / 50

Pick out the wrong statement pertaining to the decomposition of PCl5 represented by, PCl5 ? PCl3 + Cl2.Degree of dissociation of PCl5 will__________?

Decrease on addition of Cl2

Decrease on increasing the pressure of the system

None of these

Increase on addition of an inert gas at constant pressure

10 / 50

The adiabatic throttling process of a perfect gas is one of constant enthalpy__________?

Which is exemplified by a non-steady flow expansion

In which there is an increase in temperature

Which can be performed in a pipe with a constriction

In which there is a temperature drop

11 / 50

PVy = constant, holds good for an isentropic process, which is__________?

Adiabatic and irreversible

Isothermal and irreversible

Reversible and adiabatic

Reversible and isothermal

12 / 50

Refrigeration capacity of a household refrigerator may be round about ______ tons?

4.5

6.5

1.5

0.15

13 / 50

Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is_______?

Infinity

Positive

Zero

Negative

14 / 50

Pick out the wrong statement ?

An isometric process is a constant pressure process

The expansion of a gas in vacuum is an irreversible process

Free energy change for a spontaneous process is negative

Entropy change for a reversible adiabatic process is zero

15 / 50

Pick out the wrong statement ?

An ideal liquid or solid solution is defined as one in which each component obeys Raoult?s law

None of these

Henry?s law is rigorously correct in the limit of infinite dilution

If Raoult?s law is applied to one component of a binary mixture; Henry?s law or Raoult?s law is applied to the other component also

16 / 50

Specific heat of a gas for a reversible adiabatic process is_________?

None of these

Negative

Zero

Infinity

17 / 50

Reduced pressure of a gas is the ratio of its___________?

Pseudocritical pressure to pressure

Pressure to critical pressure

Pressure to pseudocritical pressure

Critical pressure to pressure

18 / 50

Rotary lime kiln is an example of a/an ______ system?

Isolated

Closed

Non-thermodynamic

Open

19 / 50

Pick out the wrong statement?

There is an increase in entropy, when a spontaneous change occurs in an isolated system

Cp of monatomic gases such as metallic vapor is about 5 kcal/kg.atom

The heat capacity of solid inorganic substance is exactly equal to the heat capacity of the substance in the molten state

At absolute zero temperature, the heat capacity for many pure crystalline substances is zero

20 / 50

Pick out the wrong statement ?

The chemical potential of species ?i? in the mixture (?i) is mathematically represented as,?i = ?(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

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

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

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

21 / 50

Specific volume of an ideal gas is______?

None of these

Equal to its density

The reciprocal of its density

Proportional to pressure

22 / 50

Sublimation temperature of dry ice (solid CO2) is _____ ?C?

-78

-273

23 / 50

Pick out the wrong statement?

During a reversible adiabatic process, the entropy of a substance remains constant

The values of (?P/?V)T and (?2P/?V2)T are zero for a real gas at its critical point

Thermal efficiency of a Carnot engine depends upon the properties of the working fluid besides the source & sink temperatures

Heat transferred is equal to the change in the enthalpy of the system, for a constant pressure, non-flow, mechanically reversible process

24 / 50

Pick out the correct statement?

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

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

A process is irreversible as long as ? S for the system is greater than zero

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

25 / 50

Pick out the correct statement?

The efficiency of a Carnot engine increases, if the sink temperature is decreased

All A, B. and C

The available energy in an isolated system for all irreversible (real) processes decreases

The reversible work for compression in non-flow process under isothermal condition is the change in Helmholtz free energy

26 / 50

Pick out the extensive property out of the following ?

Refractive index

Surface tension

Specific heat

Free energy

27 / 50

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

More than

Less than

Same as

Not related to

28 / 50

Pick out the wrong statement__________?

Phase rule variables are intensive properties

Heat and work are both state function

CP and CV are state function

The work done by expansion of a gas in vacuum is zero

29 / 50

Sound waves propagation in air exemplifies an _______ process?

Isothermal

Adiabatic

None of these

Isometric

30 / 50

The ammonia synthesis reaction represented by N2 + 3H2 ? 2NH3; ?H = ? 22.4 kcal, is___________?

Endothermic

Isothermal

Adiabatic

Exothermic

31 / 50

Pick out the undesirable property for a good refrigerant ?

High thermal conductivity

Low freezing point

High viscosity

Large latent heat of vaporisation

32 / 50

Pick out the correct statement?

An ideal gas on expansion in vacuum gets cooled

A real gas on expansion in vacuum cools down whereas ideal gas remains unaffected

An ideal gas on expansion in vacuum gets heated up

A real gas on expansion in vacuum gets heated up

33 / 50

Requisites of a reversible process is that the ______?

System and surroundings pressure be equal

Friction in the system should be absent

System and surroundings temperature be equal

None of these

34 / 50

Pick out the wrong statement ?

Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation

For a two phase system in equilibrium made up of four non-reacting chemical species, the number of degrees of freedom is 4

Minimum number of degree of freedom of a system is zero

Degree of freedom of a system containing a gaseous mixture of helium, carbon dioxide and hydrogen is 4

35 / 50

Pick out the wrong statement?

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

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

A refrigeration cycle violates the second law of thermodynamics

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

36 / 50

Pick out the correct statement?

Like internal energy and enthalpy, the absolute value of standard entropy for elementary substances is zero

Melting of ice involves increase in enthalpy and a decrease in randomness

The internal energy of an ideal gas depends only on its pressure

Maximum work is done under reversible conditions

37 / 50

Pick out the wrong statement ?

Enthalpies of all elements in their standard states are assumed to be zero

Combustion reactions are never endothermic in nature

Clausius-Clapeyron equation is not applicable to melting process

Heat of reaction at constant volume is equal to the change in internal energy

38 / 50

Refrigeration cycle__________?

Neither A. nor B

Both A. and B

Violates second law of thermodynamics

Involves transfer of heat from low temperature to high temperature

39 / 50

PV? = Constant (where, ? = Cp/Cv) is valid for a/an _______ process?

Isobaric

Adiabatic

Isentropic

Isothermal

40 / 50

Standard temperature and pressure (S.T.P.) is___________?

15?C and 1 kgf/cm2

0?C and 1 kgf/cm2

15?C and 750 mm Hg

0?C and 750 mm Hg

41 / 50

Solubility of a substance which dissolves with an increase in volume and liberation of heat will be favoured by the________?

High pressure and high temperature

Low pressure and low temperature

High pressure and low temperature

Low pressure and high temperature

42 / 50

Pick out the wrong statement?

The entropy of a substance does not remain constant during a reversible adiabatic change

The net change in entropy in any reversible cycle is always zero

The entropy of the system as a whole in an irreversible process increases

The entropy of the universe tends to a maximum

43 / 50

Pick out the wrong statement?

Entropy of a system decreases with the evolution of heat

Surface tension of a substance vanishes at critical point, as there is no distinction between liquid and vapour phases at its critical point

Change of internal energy is negative for exothermic reactions

The eccentric factor for all materials is always more than one

44 / 50

Pick out the wrong statement ?

At constant pressure, solubility of a gas in a liquid diminishes with rise in temperature

Normally, the gases which are easily liquefied are more soluble in common solvents

The gases which are capable of forming ions in aqueous solution are much more soluble in water than in other solvents

At constant pressure, solubility of a gas in a liquid increases with rise in temperature

45 / 50

Tea kept in a thermos flask is vigorously shaken. If the tea is considered as a system, then its temperature will__________?

Remain unchanged

First fall and then rise

Increase

Decrease

46 / 50

Second law of thermodynamics is concerned with the__________?

Irreversible processes only

Amount of energy transferred

Direction of energy transfer

Non-cyclic processes only

47 / 50

Pick out the wrong statement ?

The fugacity co-efficient is zero for an ideal gas

Activity co-efficient is dimensionless.

In a mixture of ideal gases, the fugacity of a component is equal to the partial pressure of the component.

In case of an ideal gas, the fugacity is equal to its pressure.

48 / 50

Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400?C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 kJ/kg. K) The exit condition of steam is________?

Partially condensed vapour with quality of 0.9

Partially condensed vapour with quality of 0.1

Superheated vapour

Saturated vapour

49 / 50

Refrigerants commonly used for domestic refrigerators are__________?

NH3 or CO2

Propane

Ethyl chloride or methyl chloride

Freon-12

50 / 50

Specific/molar Gibbs free energy for a pure substance does not change during_________?

Either A, B. or C.

Melting

Sublimation

Vaporisation

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