Question 1

From the measured molar heat capacities and the equipartition theorem, for a diatomic gas molecule the number of degrees of freedom from rotational motion are

Accepted Answer

A)   3.
B)   0.
C)   5.
D)   2.
E)   6.F) All of the above
G) C) and D) D

Question 2

You can vary the efficiency of a Carnot engine by varying the temperature of the cold reservoir while maintaining the hot reservoir at constant temperature. The curve that best represents the efficiency of such an engine as a function of the temperature of the cold reservoir is

Accepted Answer

A)   1.
B)   2.
C)   3.
D)   4.
E)   5.F) All of the above
G) A) and B) D

Question 3

The curve on the graph of pressure versus density that best represents an isothermal process is

Accepted Answer

A)   1.
B)   2.
C)   3.
D)   4.
E)   5.F) A) and E)
G) D) and E)

Question 4

A steam power plant with an efficiency of 65% of the maximum thermodynamic efficiency operates between 250oC and 40oC. What is the change in the entropy of the universe when this plant does 1.0 kJ of work?

Accepted Answer

A)   16 J/K
B)   1.7 J/K
C)   55 J/K
D)   1.7 mJ/K
E)   0.85 J/KF) A) and C)
G) A) and B)

Question 5

A container has 0.2 mole of O2 gas and the gas is heated from 0°C to 100°C. What is the change in entropy of the gas? R = 8.314 J/mol · K.)

Accepted Answer

A)   1.82 J/K
B)   1.30 J/K
C)   0.78 J/K
D)   26.8 J/K
E)   zeroF) A) and B)
G) A) and E)

Question 6

An electric power plant generates 100 MW of power at an efficiency of 35%. At what rate must water be circulated pass the condenser if the change in water temperature is not to exceed 10oC?

Accepted Answer

A)   2400 kg/s
B)   6800 kg/s
C)   3400 kg/s
D)   11300 kg/s
E)   4400 kg/sF) B) and E)
G) C) and E) E

Question 7

In an adiabatic reversible compression of an ideal gas, there is a decrease in

Accepted Answer

A)   pressure.
B)   temperature.
C)   internal energy.
D)   volume.
E)   rms molecular velocity.F) A) and D)
G) A) and C)

Question 8

An ideal monatomic gas has a molar heat capacity Cmp at constant pressure. What is the molar heat capacity at constant volume of an ideal diatomic gas?

Accepted Answer

A)   Cmp 
B)   Cmp + R
C)   Cmp - R
D)   Cmp + 3R/2
E)   Cmp - 3R/2F) All of the above
G) B) and D)

Question 9

An ideal gas with an initial volume of 3 L at a pressure of 2 atm is compressed adiabatically until it has a volume of 2 L; then it is cooled at constant volume until its temperature drops to its initial value. The final pressure is

Accepted Answer

A)    atm.
B)   2 atm.
C)   3 atm.
D)   4/3 atm.
E)   6 atm.F) A) and D)
G) D) and E)

Question 10

iaf = 50 cal, the work along iaf is Wiaf = 20 cal. Along ibf, if Qibf = 40 cal, the work done, Wibf, is A)  10 cal. B)  20 cal. C)  30 cal. D)  40 cal. E)  50 cal." class="answers-bank-image d-inline" rel="preload" > An ideal gas system changes from state i to state f by paths iaf and ibf. If the heat added along iaf is Qiaf = 50 cal, the work along iaf is Wiaf = 20 cal. Along ibf, if Qibf = 40 cal, the work done, Wibf, is

Accepted Answer

A)   10 cal.
B)   20 cal.
C)   30 cal.
D)   40 cal.
E)   50 cal.F) B) and C)
G) A) and E)

Question 11

In a certain thermodynamic process, 1000 cal of heat are added to a gas confined in a cylinder. At the same time, 1000 J of work are done by the gas as it expands. The increase in internal energy of the gas is

Accepted Answer

A)   zero.
B)   3186 J.
C)   -239 J.
D)   5186 J.
E)   1239 J.F) A) and C)
G) A) and B)

Question 12

An ideal gas initially at 50oC and pressure P1 = 100 kPa occupies a volume V1 = 3 L. It undergoes a quasi-static, isothermal expansion until its pressure is reduced to 50 kPa. How much heat enters the gas during this process? R = 8.314 J/mol · K = 8.206 L · atm/mol · K.

Accepted Answer

A)   116 J
B)   208 J
C)   256 J
D)   304 J
E)   416 JF) None of the above
G) C) and E)

Question 13

A liquid is irregularly stirred in a well-insulated container and thereby undergoes a rise in temperature. Regarding the liquid as a system, you can say that

Accepted Answer

A)   heat has been transferred.
B)   the rise in temperature indicates work done by the system.
C)   the internal energy has been unchanged.
D)   the work done by the system equals the work done on the system.
E)   there is a positive change in internal energy.F) C) and E)
G) C) and D)

Question 14

One mole of an ideal gas γ = 5/3)  expands adiabatically and quasi-statically from a pressure P1 = 6 atm and a temperature of 50oC to a pressure P2 = 4 atm. How much work is done by the gas during this process? R = 8.314 J/mol · K = 8.206 L · atm/mol · K.

Accepted Answer

A)   50.3 kJ
B)   56.2 kJ
C)   95.9 kJ
D)   131 kJ
E)   158 kJF) D) and E)
G) None of the above

Question 15

H = 400 K and cold reservoir at TL = 300 K, in a cycle from a→b→c→d→a. From a→b the gas undergoes an isothermal expansion, changing its volume from Va to 2.5Va. From b→c, the pressure is reduced at a constant volume. From c→d, the gas undergoes an isothermal compression, and from d→a, the pressure is increased at a constant volume until the gas is back at the original condition at a. How much heat is absorbed in going from a→b? A)  30.5 J B)  7.62 J C)  22.9 J D)  8.31 J E)  0.917 J" class="answers-bank-image d-inline" rel="preload" > An ideal heat engine uses 0.01 mole of gas and operates between a hot reservoir at TH = 400 K and cold reservoir at TL = 300 K, in a cycle from a→b→c→d→a. From a→b the gas undergoes an isothermal expansion, changing its volume from Va to 2.5Va. From b→c, the pressure is reduced at a constant volume. From c→d, the gas undergoes an isothermal compression, and from d→a, the pressure is increased at a constant volume until the gas is back at the original condition at a. How much heat is absorbed in going from a→b?

Accepted Answer

A)   30.5 J
B)   7.62 J
C)   22.9 J
D)   8.31 J
E)   0.917 JF) B) and D)
G) C) and D)

Question 16

In a system composed of gas contained in a cylinder fitted with a piston, an adiabatic expansion causes the temperature of the gas to drop because

Accepted Answer

A)   heat is given up by the system when the piston moves.
B)   the pressure of the gas remains constant.
C)   work is done on the system as the gas expands.
D)   work done by the system is entirely at the expense of its internal energy.
E)   heat is absorbed by the piston when it does work.F) C) and D)
G) B) and E)

Question 17

A Carnot heat engine absorbs heat Q from a hot reservoir at 127oC and exhausts heat to a cold reservoir at 27oC. How much heat is exhausted to the cold reservoir?

Accepted Answer

A)   Q
B)   27Q/127
C)   127Q/27
D)   3Q/4
E)   4Q/3F) A) and C)
G) D) and E)

Question 18

Three moles of a gas at T = 250 K expand quasi-statically and adiabatically from an initial volume of 30 L to a final volume of 60 L. The change in entropy of the gas during this expansion is R = 8.314 J/mol·K)

Accepted Answer

A)   17.3 J/K.
B)   18.6 J/K.
C)   -17.4 J/K.
D)   19.5 J/K.
E)   zero.F) A) and C)
G) A) and B)

Question 19

A system is said to go through an adiabatic process if, throughout the process,

Accepted Answer

A)   it maintains a constant ratio of pressure to temperature.
B)   it remains at a constant temperature.
C)   it loses no heat to its surroundings and gains none from them.
D)   its total energy increases.
E)   it does no work on its surroundings.F) D) and E)
G) C) and D)

Question 20

The diagram below is a schematic of a heat engine. The three quantities, QH, QL, and W are represented, respectively, by H, QL, and W are represented, respectively, by   A)  1, 2, 3. B)  1, 3, 2. C)  2, 3, 1. D)  3, 1, 2 E)  3, 2, 1." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   1, 2, 3.
B)   1, 3, 2.
C)   2, 3, 1.
D)   3, 1, 2
E)   3, 2, 1.F) B) and E)
G) C) and E)

Exam 15: Thermodynamics II

From the measured molar heat capacities and the equipartition theorem, for a diatomic gas molecule the number of degrees of freedom from rotational motion are

Correct Answer
verified
D

You can vary the efficiency of a Carnot engine by varying the temperature of the cold reservoir while maintaining the hot reservoir at constant temperature. The curve that best represents the efficiency of such an engine as a function of the temperature of the cold reservoir is

Correct Answer
verified
D

The curve on the graph of pressure versus density that best represents an isothermal process is

Correct Answer
verified

A steam power plant with an efficiency of 65% of the maximum thermodynamic efficiency operates between 250^oC and 40^oC. What is the change in the entropy of the universe when this plant does 1.0 kJ of work?

Correct Answer
verified

A container has 0.2 mole of O₂ gas and the gas is heated from 0°C to 100°C. What is the change in entropy of the gas? R = 8.314 J/mol · K.)

Correct Answer
verified

An electric power plant generates 100 MW of power at an efficiency of 35%. At what rate must water be circulated pass the condenser if the change in water temperature is not to exceed 10^oC?

Correct Answer
verified
E

In an adiabatic reversible compression of an ideal gas, there is a decrease in

Correct Answer
verified

An ideal monatomic gas has a molar heat capacity C_mp at constant pressure. What is the molar heat capacity at constant volume of an ideal diatomic gas?

Correct Answer
verified

An ideal gas with an initial volume of 3 L at a pressure of 2 atm is compressed adiabatically until it has a volume of 2 L; then it is cooled at constant volume until its temperature drops to its initial value. The final pressure is

Correct Answer
verified

An ideal gas system changes from state i to state f by paths iaf and ibf. If the heat added along iaf is Q_iaf = 50 cal, the work along iaf is W_iaf = 20 cal. Along ibf, if Q_ibf = 40 cal, the work done, W_ibf, is

Correct Answer
verified

In a certain thermodynamic process, 1000 cal of heat are added to a gas confined in a cylinder. At the same time, 1000 J of work are done by the gas as it expands. The increase in internal energy of the gas is

Correct Answer
verified

An ideal gas initially at 50^oC and pressure P₁ = 100 kPa occupies a volume V₁ = 3 L. It undergoes a quasi-static, isothermal expansion until its pressure is reduced to 50 kPa. How much heat enters the gas during this process? R = 8.314 J/mol · K = 8.206 L · atm/mol · K.

Correct Answer
verified

A liquid is irregularly stirred in a well-insulated container and thereby undergoes a rise in temperature. Regarding the liquid as a system, you can say that

Correct Answer
verified

One mole of an ideal gas γ = 5/3) expands adiabatically and quasi-statically from a pressure P₁ = 6 atm and a temperature of 50^oC to a pressure P₂ = 4 atm. How much work is done by the gas during this process? R = 8.314 J/mol · K = 8.206 L · atm/mol · K.

Correct Answer
verified

Correct Answer
verified

In a system composed of gas contained in a cylinder fitted with a piston, an adiabatic expansion causes the temperature of the gas to drop because

Correct Answer
verified

A Carnot heat engine absorbs heat Q from a hot reservoir at 127^oC and exhausts heat to a cold reservoir at 27^oC. How much heat is exhausted to the cold reservoir?

Correct Answer
verified

Three moles of a gas at T = 250 K expand quasi-statically and adiabatically from an initial volume of 30 L to a final volume of 60 L. The change in entropy of the gas during this expansion is R = 8.314 J/mol·K)

Correct Answer
verified

A system is said to go through an adiabatic process if, throughout the process,

Correct Answer
verified

The diagram below is a schematic of a heat engine. The three quantities, Q_H, Q_L, and W are represented, respectively, by

Correct Answer
verified

Exam 15: Thermodynamics II

From the measured molar heat capacities and the equipartition theorem, for a diatomic gas molecule the number of degrees of freedom from rotational motion are

Correct AnswerverifiedD

You can vary the efficiency of a Carnot engine by varying the temperature of the cold reservoir while maintaining the hot reservoir at constant temperature. The curve that best represents the efficiency of such an engine as a function of the temperature of the cold reservoir is

Correct AnswerverifiedD

The curve on the graph of pressure versus density that best represents an isothermal process is

Correct AnswerverifiedShow Answer

A steam power plant with an efficiency of 65% of the maximum thermodynamic efficiency operates between 250oC and 40oC. What is the change in the entropy of the universe when this plant does 1.0 kJ of work?

Correct AnswerverifiedShow Answer

A container has 0.2 mole of O2 gas and the gas is heated from 0°C to 100°C. What is the change in entropy of the gas? R = 8.314 J/mol · K.)

Correct AnswerverifiedShow Answer

An electric power plant generates 100 MW of power at an efficiency of 35%. At what rate must water be circulated pass the condenser if the change in water temperature is not to exceed 10oC?

Correct AnswerverifiedE

In an adiabatic reversible compression of an ideal gas, there is a decrease in

Correct AnswerverifiedShow Answer

An ideal monatomic gas has a molar heat capacity Cmp at constant pressure. What is the molar heat capacity at constant volume of an ideal diatomic gas?

Correct AnswerverifiedShow Answer

An ideal gas with an initial volume of 3 L at a pressure of 2 atm is compressed adiabatically until it has a volume of 2 L; then it is cooled at constant volume until its temperature drops to its initial value. The final pressure is

Correct AnswerverifiedShow Answer

An ideal gas system changes from state i to state f by paths iaf and ibf. If the heat added along iaf is Qiaf = 50 cal, the work along iaf is Wiaf = 20 cal. Along ibf, if Qibf = 40 cal, the work done, Wibf, is

Correct AnswerverifiedShow Answer

In a certain thermodynamic process, 1000 cal of heat are added to a gas confined in a cylinder. At the same time, 1000 J of work are done by the gas as it expands. The increase in internal energy of the gas is

Correct AnswerverifiedShow Answer

An ideal gas initially at 50oC and pressure P1 = 100 kPa occupies a volume V1 = 3 L. It undergoes a quasi-static, isothermal expansion until its pressure is reduced to 50 kPa. How much heat enters the gas during this process? R = 8.314 J/mol · K = 8.206 L · atm/mol · K.

Correct AnswerverifiedShow Answer

A liquid is irregularly stirred in a well-insulated container and thereby undergoes a rise in temperature. Regarding the liquid as a system, you can say that

Correct AnswerverifiedShow Answer

One mole of an ideal gas γ = 5/3) expands adiabatically and quasi-statically from a pressure P1 = 6 atm and a temperature of 50oC to a pressure P2 = 4 atm. How much work is done by the gas during this process? R = 8.314 J/mol · K = 8.206 L · atm/mol · K.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In a system composed of gas contained in a cylinder fitted with a piston, an adiabatic expansion causes the temperature of the gas to drop because

Correct AnswerverifiedShow Answer

A Carnot heat engine absorbs heat Q from a hot reservoir at 127oC and exhausts heat to a cold reservoir at 27oC. How much heat is exhausted to the cold reservoir?

Correct AnswerverifiedShow Answer

Three moles of a gas at T = 250 K expand quasi-statically and adiabatically from an initial volume of 30 L to a final volume of 60 L. The change in entropy of the gas during this expansion is R = 8.314 J/mol·K)

Correct AnswerverifiedShow Answer

A system is said to go through an adiabatic process if, throughout the process,

Correct AnswerverifiedShow Answer

The diagram below is a schematic of a heat engine. The three quantities, QH, QL, and W are represented, respectively, by

Correct AnswerverifiedShow Answer

Correct Answer
verified
D

Correct Answer
verified
D

Correct Answer
verified

A steam power plant with an efficiency of 65% of the maximum thermodynamic efficiency operates between 250^oC and 40^oC. What is the change in the entropy of the universe when this plant does 1.0 kJ of work?

Correct Answer
verified

A container has 0.2 mole of O₂ gas and the gas is heated from 0°C to 100°C. What is the change in entropy of the gas? R = 8.314 J/mol · K.)

Correct Answer
verified

An electric power plant generates 100 MW of power at an efficiency of 35%. At what rate must water be circulated pass the condenser if the change in water temperature is not to exceed 10^oC?

Correct Answer
verified
E

Correct Answer
verified

An ideal monatomic gas has a molar heat capacity C_mp at constant pressure. What is the molar heat capacity at constant volume of an ideal diatomic gas?

Correct Answer
verified

Correct Answer
verified

An ideal gas system changes from state i to state f by paths iaf and ibf. If the heat added along iaf is Q_iaf = 50 cal, the work along iaf is W_iaf = 20 cal. Along ibf, if Q_ibf = 40 cal, the work done, W_ibf, is

Correct Answer
verified

Correct Answer
verified

An ideal gas initially at 50^oC and pressure P₁ = 100 kPa occupies a volume V₁ = 3 L. It undergoes a quasi-static, isothermal expansion until its pressure is reduced to 50 kPa. How much heat enters the gas during this process? R = 8.314 J/mol · K = 8.206 L · atm/mol · K.

Correct Answer
verified

Correct Answer
verified

One mole of an ideal gas γ = 5/3) expands adiabatically and quasi-statically from a pressure P₁ = 6 atm and a temperature of 50^oC to a pressure P₂ = 4 atm. How much work is done by the gas during this process? R = 8.314 J/mol · K = 8.206 L · atm/mol · K.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A Carnot heat engine absorbs heat Q from a hot reservoir at 127^oC and exhausts heat to a cold reservoir at 27^oC. How much heat is exhausted to the cold reservoir?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The diagram below is a schematic of a heat engine. The three quantities, Q_H, Q_L, and W are represented, respectively, by

Correct Answer
verified