Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemical Engineering Reviewer > Process and Solution Thermodynamics (Archived) > Flashcards

Process and Solution Thermodynamics (Archived) Flashcards

(This deck is archived.) Concepts and calculation techniques necessary for thermodynamic analyses of processes and mixtures; physical chemistry concepts are also included.

1
Q

Sublimation temperature of dry ice (solid CO2) is
___°C.

A

-78

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The equation relating E, P, V, and T which is true for all substances under all conditions is given by (𝜕E/𝜕V)T = T(𝜕P/𝜕T)H - P. This equation is called the ____.
a. Maxwell Equation
b. Thermodynamic Equation of State
c. Equation of State
d. Redlich-Kwong Equation of State

A

Thermodynamic Equation of State

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Henry’s law is closely obeyed by a gas, when its ____ is extremely high.
a. Pressure
b. Solubility
c. Temperature
d. None of these

A

d. None of these

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

If an ideal solution is formed by mixing two pure liquids in any proportion, then the ____ of mixing is zero.
a. Enthalpy
b. Volume
c. Both A and B
d. Neither A nor B

A

Both A and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The ammonia synthesis reaction represented by N2 + 3 H2 ↔ 2 NH3; ∆H = −22.4 kcal is
a. Endothermic
b. Exothermic
c. Isothermal
d. Adiabatic

A

Exothermic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

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

A

Faster than Y

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which of the following has the minimum value of COP for a given refrigeration effect?
a. Reverse Carnot Cycle
b. Ordinary Vapour-Compression Cycle
c. Vapor-compression process with a reversible
expansion engine
d. Air refrigeration cycle

A

Air refrigeration cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

No work is done by the system, when a reaction occurs at constant
a. Volume
b. Temperature
c. Pressure
d. None of these

A

Volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In the reaction, H2 + I2 ↔ 2HI, addition of an inert gas will

A

Not affect the equilibrium conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The work done in isothermal compression compared to that in adiabatic compression will be

A

More

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens in a reversible adiabatic expansion process?

A

Cooling takes place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which of the following is affected by the temperature?
a. Fugacity
b. Activity coefficient
c. Free energy
d. All of the above

A

All of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which is an example of closed system?
a. Air compressor
b. Liquid cooling system of an automobile
c. Boiler
d. None of these

A

Liquid cooling system of an automobile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Entropy of an ideal gas depends upon its
a. Pressure
b. Temperature
c. Both A and B
d. Neither A nor B

A

Both A and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

At equilibrium condition, the chemical potential of a material in different phases in contact with each other is equal. The chemical potential for a real gas (µ) is given by (where, µ° = standard chemical potential at unit fugacity (f° = 1 atm) and the gas behaves ideally).
a. µ° + RT ln f
b. µ° + R ln f
c. µ° + T ln f
d. µ° + (R/T) ln f

A

µ° + RT ln f

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Partial molal quantities are important in the study of
a. Ideal gases
b. Ideal solutions
c. Non-ideal mixtures
d. A pure component

A

Non-ideal mixtures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

For organic compounds, group condition method can be used for the estimation of
a. Critical properties
b. Specific gravity
c. Specific volume
d. Thermal conductivity

A

Critical properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (where, T1>T2) is given by (T1-T2)/T1. The coefficient of performance (COP) of a Carnot heat pump operating between T1 and T2 is given by
a. T1/(T1-T2)
b. T2/(T1-T2)
c. T1/T2
d. T2/T1

A

T1/(T1-T2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Internal energy of an element at 1 atm and 25°C is ____ kcal/kg-mole.

A

0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

At the critical point of a substance
a. The surface tension vanishes
b. Liquid and vapour have the same density
c. There is no distinction between liquid and vapour phases
d. All of the above

A

All of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In a P-V diagram (for an ideal gas), an isothermal curve will coincide with an adiabatic curve (through a point), when
a. Cp < Cv
b. Cp = Cv
c. Cp > Cv
d. Cp ≥ Cv

A

Cp = Cv

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The shape of T-S diagram for Carnot Cycle is a
a. Rectangle
b. Rhombus
c. Trapezoid
d. Circle

A

Rectangle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

With increase in compression ratio, the efficiency of
the otto engine
a. Increases
b. Decreases
c. Remains constant
d. Increases linearly

A

Increases

η = 1 - 1/r^(k-1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the degree of freedom for a system comprising liquid water equilibrium with its vapour?

A

1

df = N (component) - π (phase) - r (reaction) + 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

____ functions are exemplified by heat and work.
a. Path
b. Point
c. State
d. None of these

A

Path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to the ____ mean of the P1 and P2 (where, P1 and P2 are initial and final pressures respectively.
a. Logarithmic
b. Arithmetic
c. Geometric
d. Harmonic

A

geometric

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Helmholtz free energy (A) is defined as
a. A = H − TS
b. A = E − TS
c. A = H + TS
d. None of these

A

A = E - TS

E is usually U (internal energy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Gibbs free energy (F) is defined as
a. F = E − TS
b. F = H − TS
c. F = H + TS
d. F = E + TS

A

F = H - TS

F is usually G (Gibbs energy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

A system is said to be at equilibrium if the entropy of the system has reached ____ value.

A

Maximum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

In the reaction, C + O2 → CO2; ∆H = −94 kcal. What is the heat content (enthalpy) of O2?

A

Zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The Maxwell relation derived from the differential expression for the Helmholtz free energy (dA) is
a. (∂T/∂V)S = - (∂P/∂S)V
b. (∂S/∂P)T = - (∂V/∂T)P
c. (∂V/∂S)P = (∂T/∂P)S
d. (∂S/∂V)T = (∂P/∂T)V

A

(∂S/∂V)T = (∂P/∂T)V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which of the following processes can not be made reversible even under ideal condition of operation?
a. Free expansion of a gas
b. Compression of air in a compressor
c. Expansion of steam in a turbine
d. All of the above

A

Free expansion of a gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Heat is added at constant pressure in an ideal ____ cycle.
a. Stirling
b. Brayton
c. Rankine
d. Both B and C

A

Both B and C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Heat is added at constant temperature in an ideal ____ cycle.
a. Stirling
b. Brayton
c. Rankine
d. Both B and C

A

Stirling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

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 and B
d. Neither A nor B

A

Both A and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

For a constant volume process ____ by the system is used only to increase the internal energy.
a. Heat absorbed
b. Work done
c. Both A and B
d. Neither A nor B

A

Heat absorbed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Which of the following is not a common refrigerant?
a. Freon-12
b. Ethylene
c. Ammonia
d. Carbon Dioxide

A

Ethylene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Which of the following is not a reversible process?
a. Expansion of an ideal gas against constant pressure
b. Atmospheric pressure vaporization of water at 100°C
c. Solution of NaCl in water at 50°C
d. None of these

A

Solution of NaCl in water at 50°C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

For spontaneous changes in an isolated system (S = entropy)
a. Ds = 0
b. Ds < 0
c. Ds > 0
d. Ds = constant

A

dS > 0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

A gas performs the maximum work, when it expands
a. Non-uniformly
b. Adiabatically
c. Isobarically
d. Isothermally

A

Isobarically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Degree of freedom of a system consisting of a gaseous mixture of H2 and NH3 will be

A

3

df = N - π - r + 2

42
Q

A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system
a. Its internal energy (U) decreases and its entropy (S) increases
b. U and S both decreases
c. U decreases but S is constant
d. U is constant but S decreases

A

U and S both decreases

43
Q

The expression for entropy change given by, ∆S = −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

A

Reversible isothermal volume change

44
Q

For any system, what is the minimum number of degrees of freedom?

A

0

45
Q

Which of the following is not a unit of the equilibrium constant Kp? (where, ∆x = number of moles of products - number of moles of reactants)
a. (atm)^∆x, when ∆x is negative
b. (atm)^∆x, when ∆x is positive
c. Dimensionless, when ∆x = 0
d. (atm)^∆(x²), when ∆x > 0

A

(atm)^∆(x²), when ∆x > 0

46
Q

Equilibrium constant of a reaction varies with the
a. Initial concentration of the reactant
b. Pressure
c. Temperature
d. None of these

A

Temperature

47
Q

Which of the following will increase the volume of a real gas by four times?
a. Doubling the absolute temperature as well as pressure of the gas
b. Reducing pressure to one fourth at constant temperature
c. Reducing temperature to one fourth at constant pressure
d. Reducing the temperature to half and doubling the pressure

A

Reducing pressure to one fourth at constant temperature

48
Q

The eccentric factor of a material, ‘ω’ is defined as ω = − log10(Pr^sat)Tr^-1 − 1 = 0.7, where Pr^sat = reduced vapor pressure, Tr = reduced temperature. The value of accentric factor is always

A

< 1

49
Q

The number of degrees of freedom for a mixture of ice and water (liquid) are

A

1

df = N - π - r + 2

50
Q

“A solute distributes itself between two non-miscible 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 amount.” This is

A

the distribution law

51
Q

What is the number of degrees of freedom for liquid water in equilibrium with a mixture of nitrogen and water vapor?

A

2

df = N - π - r + 2

52
Q

The first law of thermodynamics is a restatement of the law of conservation of

A

Energy

53
Q

Entropy of the system decreases, when
a. Snow melts into water
b. A gas expands spontaneously from high pressure to low pressure
c. Water is converted into ice
d. Both B and C

A

Both B and C

54
Q

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 a system and surrounding remains the same.
d. None of the above.

A

None of the above.

55
Q

If we increase the pressure on a substance (which is at its triple point), then the triple point

A

Remains unchanged

56
Q

Maximum work that could be secured by expanding the gas over a given pressure range is the ____ work.

A

Isothermal

57
Q

The fusion of a crystalline solid at its melting point to form a liquid at the same temperature is accompanied by
a. Decrease in enthalpy corresponding to evolution of heat
b. Decrease of entropy
c. Increase in enthalpy corresponding to absorption of heat
d. No change in enthalpy

A

Increase in enthalpy corresponding to absorption of heat

58
Q

The minimum number of phases that can exist in a
system is

A

1

59
Q

Extensive properties of a thermodynamic system can
depend upon the ____ of the system.

A

mass

60
Q

Van Laar equation deals with the activity coefficients in

A

binary solutions

61
Q

1m3 of an ideal gas at 500K and 1000 kPa expands reversibly to 5 times its initial volume in an insulated container. If the specific heat capacity (at constant pressure) of the gas is 21 J/mol-K, the final temperature will be

A

274 K

62
Q

When pressure is applied on the system, ice ↔ water, then
a. Equilibrium can not be established
b. More ice will be formed
c. More water will be formed
d. Evaporation of water will take place

A

More water will be formed

63
Q

If different processes are used to bring about the same chemical reaction, the enthalpy change is same for all of them. This is ____ law.

A

Hess’s

64
Q

If the atmospheric temperature and dew point are nearly equal, then the relative humidity is

A

Almost 100%

65
Q

First law of thermodynamics deals with the

A

Direction of energy transfer

66
Q

In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is

A

same

67
Q

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

A

3.5

68
Q

The number of degree of freedom for an azeotropic mixture of ethanol and water in vapour-liquid equilibrium, is

A

1

69
Q

Gibbs free energy of a pure fluid approaches ____ as the pressure tends to zero at constant temperature.

A

minus infinity

70
Q

Out of the following refrigeration cycles, which one has the minimum COP (Coefficient of Performance)?
a. Air cycle
b. Carnot cycle
c. Ordinary vapour compression cycle
d. Vapour compression with a reversible expansion engine

A

Air cycle

71
Q

At absolute zero temperature, all substances have the same
a. Heat capacity
b. Crystalline structure
c. Entropy
d. None of these

A

Heat capacity

72
Q

The expression, ∆G = 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

A

With pressure changes at constant temperature

73
Q

The thermodynamic law, PV^γ = constant, is not applicable in case of
a. Ideal compression of air
b. Free expansion of an ideal gas
c. Adiabatic expansion of steam in a turbine
d. Adiabatic compression of a perfect gas

A

Free expansion of an ideal gas

74
Q

Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of

A

vaporisation

75
Q

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

A

Gibbs free energy

76
Q

For an ideal gas, the activity coefficient is

A

unity at all pressure

77
Q

For an isothermal process, the internal energy of a gas

A

remains unchanged

78
Q

If two gases have same reduced temperature and reduced pressure, then they will have the same
a. Volume
b. Mass
c. Critical temperature
d. None of these

A

None of these

accentric factor could be different

79
Q

Gibbs phase rules finds application when heat
transfer occurs by

A

condensation

80
Q

There is a change in ____ during the phase transition.
a. Volume
b. Pressure
c. Temperature
d. All of the above

A

Volume

81
Q

At a given temperature, the volume of a gas dissolved in a solvent ____ with increase in pressure.

A

remain unchanged

82
Q

Chemical engineering thermodynamics is concerned with the ____ in/of chemical processes.

A

energy transformation from one form to the
another

83
Q

A gas can be liquified by pressure alone only when its temperature is ____ its critical temperature.

A

less than or equal to

84
Q

In case of a close thermodynamic system, there is ____ across the boundaries.

A

no mass transfer but heat transfer

85
Q

Clausius – Clayperon equation is applicable to ____ equilibrium processes.
a. Solid-vapor
b. Solid-liquid
c. Liquid-vapor
d. All of the above

A

All of the above

However, SLE is not applicable due to small volume changes.

86
Q

In any spontaneous process, the ____ free energy decreases.

A

Both Helmholtz and Gibbs

87
Q

Gases are cooled in Joule-Thomson expansion, when it is ____ inversion temperature.

A

below

88
Q

Fundamental principle of refrigeration is based on the ____ law of thermodynamics.

A

Second

89
Q

Measurement of thermodynamic property of temperature is facilitated by ____ law of thermodynamics.

A

Zeroth

90
Q

A refrigerator works on the principle of ____ law of
thermodynamics.

A

Second

91
Q

Near their critical temperature, all gases occupy volumes ____ that of the ideal gas

A

less than

92
Q

An isolated system can exchange ____ with its
surroundings.

A

neither matter nor energy

93
Q

The coefficient 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

A

None of these

94
Q

Domestic refrigerators usually work on the ____
refrigeration cycle.

A

absorption

95
Q

At absolute zero temperature, the ____ of the gas is zero.

A

volume

96
Q

The melting point of paraffin wax (which contracts on solidification) ____ with pressure rise.

A

increases

97
Q

The expression for entropy change given by ∆S = nR ln(V2/V1) + nCv ln(T2/T1) is valid for

A

Simultaneous heating and expansion of an
ideal gas

98
Q

On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (𝜕P/𝜕V)S and the slope of the reversible isothermal line (𝜕P/𝜕V)T are related as (where, γ = Cp/Cv).
a. (𝜕P/𝜕V)S = (𝜕P/𝜕V)T
b. (𝜕P/𝜕V)S = [ (𝜕P/𝜕V)T ]^γ
c. (𝜕P/𝜕V)S = γ (𝜕P/𝜕V)T
d. (𝜕P/𝜕V)S = (1/γ) (𝜕P/𝜕V)T

A

(𝜕P/𝜕V)S = γ (𝜕P/𝜕V)T

99
Q

Trouton’s ratio is given by (where λb = molal heat of vaporization of a substance at its normal boiling point, kcal/kmol Tb = normal boiling point, °K.)
a. λb/Tb
b. Tb/λb
c. √(λb/Tb)
d. √(Tb/λb)

A

λb/Tb

100
Q

Isentropic process means a constant ____ process.

A

Entropy

Chemical Engineering Reviewer (42 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions