Following is the mathematical expression for

specific heat at constant pressure (Cp).

specific heat at constant volume (Cv).

The equation relating E, P, V and T which is true for all substances under all conditions is given by following equation .This equation is called the

thermodynamic equation of state.

Redlich-Kwong equation of state.

Consider the process A & B shown in the figure given below. In this case, it is possible that

process A is adiabatic while B is isothermal.

both the processes are adiabatic.

both the processes are isothermal.

process A is isothermal while B is adiabatic.

process A is adiabatic while B is isothermal.

The expression given by following equation, gives the free energy change

under reversible isothermal volume change.

with pressure changes at constant temperature.

under reversible isothermal volume change.

during heating of an ideal gas.

during cooling of an ideal gas.

Following is the mathematical expression for

specific heat at constant volume (CV).

specific heat at constant pressure (Cp).

co-efficient of thermal expansion.

specific heat at constant volume (CV).

In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respetively, the Carnot COP will be

Data insufficient, can't be found out

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

The expression for entropy change, ΔS = n Cp . ln (T₂/T₁), is valid for the __________ of a substance.

Simultaneous pressure & temperature change

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

Ordinary vapor compression cycle

Vapor compression with a reversible expansion engine

The expression for entropy change given by, ΔS = - nR ln (P₂/P₁), holds good for

Reversible isothermal volume change

A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system

Its internal energy (U) decreases and its entropy (S) increases

Which one is true for a throttling process?

The inversion temperature is same for all gases

A gas may have more than one inversion temperatures

The inversion temperature is different for different gases

The inversion temperature is same for all gases

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

838 + Mcqs in Chemical Engineering Thermodynamics in Chemical Engineering Page 5 McqOptions

201.	Following is the mathematical expression for
A.	specific heat at constant pressure (Cp).
B.	specific heat at constant volume (Cv).
C.	Joule-Thompson co-efficient.
D.	none of these.
Answer» D. none of these.

Discussion

202.	Which of the following is clausius-Clayperon equation for vaporisation of an ideal gas under the condition that the molar volume of liquid is negligible compared to that of the vapor ?
A.	A
B.	B
C.	C
D.	D
Answer» B. B

Discussion

203.	Gibbs free energy (G) is represented by, G = H - TS, whereas Helmholtz free energy, (A) is given by, A = E - TS. Which of the following is the Gibbs-Helmholtz equation
A.	A
B.	B
C.	C
D.	D
Answer» D. D

Discussion

204.	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
Answer» B. unity

Discussion

205.	Which of the following diagrams does not represent an Otto cycle ?
A.	A
B.	B
C.	C
D.	D
Answer» D. D

Discussion

206.	An ideal gas is taken around the cycle ABCA as shown in P-V diagram below. The work done by the gas during the cycle is equal to
A.	12 P₁V₁
B.	6 P₁V₁
C.	3 P₁V₁
D.	P₁V₁
Answer» D. P₁V₁

Discussion

207.	A thermodynamic system is taken from state A to B along ACB and is brought back to A along BDA as shown below in the P-V diagram. The net work done during the complete cycle is given by the area covered by
A.	P₁ACBP₂P₁
B.	ACBB'A'A
C.	ACBDA
D.	ADBB'A'A
Answer» D. ADBB'A'A

Discussion

208.	Efficiency of a Carnot engine working between temperatures T₁ and T₂ (T₁ < T₂) is
A.	A
B.	B
C.	C
D.	D
Answer» B. B

Discussion

209.	Maxwell's relation corresponding to the identity, dH = dS = Vdp + ∑μᵢ dnᵢ is
A.	A
B.	B
C.	C
D.	D
Answer» E.

Discussion

210.	Cᵥ is given by
A.	A
B.	B
C.	C
D.	D
Answer» B. B

Discussion

211.	The equation relating E, P, V and T which is true for all substances under all conditions is given by following equation .This equation is called the
A.	Maxwell's equation.
B.	thermodynamic equation of state.
C.	equation of state.
D.	Redlich-Kwong equation of state.
Answer» C. equation of state.

Discussion

212.	Joule-Thomson co-efficient which is defined by equation given below, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is
A.	0
B.	∞
C.	+ve
D.	-ve
Answer» B. ∞

Discussion

213.	Consider the process A & B shown in the figure given below. In this case, it is possible that
A.	both the processes are adiabatic.
B.	both the processes are isothermal.
C.	process A is isothermal while B is adiabatic.
D.	process A is adiabatic while B is isothermal.
Answer» D. process A is adiabatic while B is isothermal.

Discussion

214.	The ratio of equilibrium constants (Kp₂/Kp₁) at two different temperatures is given by
A.	A
B.	B
C.	C
D.	D
Answer» C. C

Discussion

215.	An ideal monoatomic gas is taken round the cycle ABCDA as shown below in the P-V diagram. The work done during the cycle is
A.	PV
B.	2PV
C.	PV/2
D.	0
Answer» B. 2PV

Discussion

216.	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, y = Cᵨ/Cᵥ)
A.	A
B.	B
C.	C
D.	D
Answer» D. D

Discussion

217.	Which of the following represents the Virial equation of state ?
A.	A
B.	B
C.	C
D.	D
Answer» C. C

Discussion

218.	Chemical potential of ith component of a system is given by
A.	A
B.	B
C.	C
D.	D
Answer» B. B

Discussion

219.	The following equation, applicable to a binary solution of components. A and B in equilibrium with their vapors at constant temperature and pressure is called the __________ equation.
A.	Van Laar
B.	Margules
C.	Gibbs-Duhem
D.	Gibbs-Duhem-Margules
Answer» E.

Discussion

220.	Joule-Thomson co-efficient is defined as
A.	A
B.	B
C.	C
D.	D
Answer» C. C

Discussion

221.	The equilibrium constant for a chemical reaction at two different temperatures is given by
A.	A
B.	B
C.	C
D.	D
Answer» B. B

Discussion

222.	The chemical potential of a component (μi) of a phase is the amount by which its capacity for doing all work, barring work of expansion is increased per unit amount of substance added for an infinitesimal addition at constant temperature and pressure. It is given by
A.	A
B.	B
C.	C
D.	D
Answer» E.

Discussion

223.	The expression given by following equation, 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.
Answer» B. under reversible isothermal volume change.

Discussion

224.	What is the value of maximum COP in case of absorption refrigeration, if refrigeration provided is at temperature, Tʀ(where, T₁ and T₂ are source & surrounding temperatures respectively.)?
A.	A
B.	B
C.	C
D.	D
Answer» B. B

Discussion

225.	Following is the mathematical expression for
A.	Joule-Thomson co-efficient.
B.	specific heat at constant pressure (Cp).
C.	co-efficient of thermal expansion.
D.	specific heat at constant volume (CV).
Answer» D. specific heat at constant volume (CV).

Discussion

226.	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
Answer» B. 1.9398

Discussion

227.	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
Answer» C. Equals 1 kcal/kmol °K

Discussion

228.	In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respetively, the Carnot COP will be
A.	5.2
B.	6.2
C.	0.168
D.	Data insufficient, can't be found out
Answer» B. 6.2

Discussion

229.	Which of the following has the least thermal efficiency?
A.	Steam engine
B.	Carnot engine
C.	Diesel engine
D.	Otto engine
Answer» B. Carnot engine

Discussion

230.	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
A.	Superheated vapour
B.	Partially condensed vapour with quality of 0.9
C.	Saturated vapour
D.	Partially condensed vapour with quality of 0.1
Answer» B. Partially condensed vapour with quality of 0.9

Discussion

231.	The expression for entropy change, ΔS = n Cp . ln (T₂/T₁), is valid for the __________ of a substance.
A.	Simultaneous pressure & temperature change
B.	Heating
C.	Cooling
D.	Both B and C
Answer» E.

Discussion

232.	Which of the following is an extensive property of a system?
A.	Heat capacity
B.	Molal heat capacity
C.	Pressure
D.	Concentration
Answer» B. Molal heat capacity

Discussion

233.	Which of the following behaves most closely like an ideal gas?
A.	He
B.	N₂
C.	O₂
D.	H₂
Answer» B. N₂

Discussion

234.	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
Answer» C. Ordinary vapor compression cycle

Discussion

235.	When a gas is expanded from high pressure region to low pressure region ; temper -ature change occurs. This phenomenon is related to the
A.	Gibbs-Duhem equation
B.	Gibbs-Helmholtz equation
C.	Third law of thermodynamics
D.	Joule-Thomson effect
Answer» E.

Discussion

236.	Which of the following is not a unit of the equilibrium constant Kp? (where, Δx = number of moles of products number of moles of reactants)
A.	(atm)Δx, when Δx is negative
B.	(atm)Δx, when Δx is positive
C.	Dimensionless, when Δx = 0
D.	(atm)Δx2, when Δx > 0
Answer» E.

Discussion

237.	The expression for entropy change given by, ΔS = - 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
Answer» C. Heating of an ideal gas

Discussion

238.	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
Answer» C. U decreases but S is constant

Discussion

239.	Degree of freedom of a system consisting of a gaseous mixture of H₂ and NH₃ will be
A.	0
B.	1
C.	2
D.	3
Answer» E.

Discussion

240.	Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole . °K
A.	0
B.	∞
C.	50
D.	100
Answer» C. 50

Discussion

241.	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
Answer» C. The inversion temperature is same for all gases

Discussion

242.	What happens in a reversible adiabatic compression?
A.	Heating occurs
B.	Cooling occurs
C.	Pressure is constant
D.	Temperature is constant
Answer» B. Cooling occurs

Discussion

243.	Which of the following is not correct for a reversible adiabatic process?
A.	TVγ-1 = constant
B.	P1-γ.TY = constant
C.	PVγ = constant
D.	None of these
Answer» E.

Discussion

244.	In the equation, PVn = constant, if the value of n = ± ∞, then it represents a reversible __________ process.
A.	Adiabatic
B.	Isometric
C.	Isentropic
D.	Isothermal
Answer» C. Isentropic

Discussion

245.	In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process.
A.	Isometric
B.	Polytropic
C.	Isentropic
D.	Isobaric
Answer» C. Isentropic

Discussion

246.	In the equation PVn = constant, if the value of n = y = Cp/Cv, then it represents a reversible __________ process.
A.	Isothermal
B.	Adiabatic
C.	Isentropic
D.	Polytropic
Answer» D. Polytropic

Discussion

247.	In the equation, PVn = constant, if the value of n = 1, then it represents a reversible __________ process.
A.	Isothermal
B.	Isobaric
C.	Polytropic
D.	Adiabatic
Answer» B. Isobaric

Discussion

248.	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
Answer» B. Isothermal

Discussion

249.	High pressure steam is expanded adiabati-cally and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process:
A.	Δ H = 0 and ΔS = 0
B.	Δ H ≠ 0 and ΔS = 0
C.	Δ H ≠ 0 and ΔS ≠ 0
D.	Δ H = 0 and ΔS ≠ 0
Answer» C. Δ H ≠ 0 and ΔS ≠ 0

Discussion

250.	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
Answer» B. T₁/(T₁ - T₂)

Discussion

Explore topic-wise MCQs in Chemical Engineering.

Following is the mathematical expression for

Which of the following is clausius-Clayperon equation for vaporisation of an ideal gas under the condition that the molar volume of liquid is negligible compared to that of the vapor ?

Gibbs free energy (G) is represented by, G = H - TS, whereas Helmholtz free energy, (A) is given by, A = E - TS. Which of the following is the Gibbs-Helmholtz equation

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

Which of the following diagrams does not represent an Otto cycle ?

An ideal gas is taken around the cycle ABCA as shown in P-V diagram below. The work done by the gas during the cycle is equal to

A thermodynamic system is taken from state A to B along ACB and is brought back to A along BDA as shown below in the P-V diagram. The net work done during the complete cycle is given by the area covered by

Efficiency of a Carnot engine working between temperatures T₁ and T₂ (T₁ < T₂) is

Maxwell's relation corresponding to the identity, dH = dS = Vdp + ∑μᵢ dnᵢ is

Cᵥ is given by

The equation relating E, P, V and T which is true for all substances under all conditions is given by following equation .This equation is called the

Joule-Thomson co-efficient which is defined by equation given below, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is

Consider the process A & B shown in the figure given below. In this case, it is possible that

The ratio of equilibrium constants (Kp₂/Kp₁) at two different temperatures is given by

An ideal monoatomic gas is taken round the cycle ABCDA as shown below in the P-V diagram. The work done during the cycle is

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, y = Cᵨ/Cᵥ)

Which of the following represents the Virial equation of state ?

Chemical potential of ith component of a system is given by

The following equation, applicable to a binary solution of components. A and B in equilibrium with their vapors at constant temperature and pressure is called the __________ equation.

Joule-Thomson co-efficient is defined as

The equilibrium constant for a chemical reaction at two different temperatures is given by

The chemical potential of a component (μi) of a phase is the amount by which its capacity for doing all work, barring work of expansion is increased per unit amount of substance added for an infinitesimal addition at constant temperature and pressure. It is given by

The expression given by following equation, gives the free energy change

What is the value of maximum COP in case of absorption refrigeration, if refrigeration provided is at temperature, Tʀ(where, T₁ and T₂ are source & surrounding temperatures respectively.)?

Following is the mathematical expression for

Cp of a gas at its critical temperature and pressure

In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respetively, the Carnot COP will be

Which of the following has the least thermal efficiency?

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

The expression for entropy change, ΔS = n Cp . ln (T₂/T₁), is valid for the __________ of a substance.

Which of the following is an extensive property of a system?

Which of the following behaves most closely like an ideal gas?

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

When a gas is expanded from high pressure region to low pressure region ; temper -ature change occurs. This phenomenon is related to the

Which of the following is not a unit of the equilibrium constant Kp? (where, Δx = number of moles of products number of moles of reactants)

The expression for entropy change given by, ΔS = - nR ln (P₂/P₁), holds good for

A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system

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

Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole . °K

Which one is true for a throttling process?

What happens in a reversible adiabatic compression?

Which of the following is not correct for a reversible adiabatic process?

In the equation, PVn = constant, if the value of n = ± ∞, then it represents a reversible __________ process.

In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process.

In the equation PVn = constant, if the value of n = y = Cp/Cv, then it represents a reversible __________ process.

In the equation, PVn = constant, if the value of n = 1, then it represents a reversible __________ process.

In the equation, PVn = Constant, if the value of n = 0, then it represents a reversible __________ process.

High pressure steam is expanded adiabati-cally and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process:

Co-efficient of performance for a reversed Carnot cycle working between temperatures T₁ and T₂ (T₁ > T₂) is