Entropy and the Second Law of Thermodynamics: Master the Fundamentals

Question 1

According to the Second Law of Thermodynamics, what happens to the entropy of an isolated system?

Accepted Answer

Increases or remains constant

Answer

Decreases steadily

Answer

Remains constant

Answer

Fluctuates randomly

Question 2

Consider a system undergoing an isothermal expansion. What is the change in entropy of the system?

Accepted Answer

Positive

Answer

Zero

Answer

Negative

Answer

Indeterminate

Question 3

Which of the following is NOT a consequence of the Second Law of Thermodynamics?

Accepted Answer

Energy can be created or destroyed

Answer

Heat engines cannot operate at 100% efficiency

Answer

Refrigerators require work to operate

Answer

The universe is constantly becoming more disordered

Question 4

The change in entropy of the surroundings during an exothermic reaction is:

Accepted Answer

Positive

Answer

Negative

Answer

Zero

Answer

Dependent on the temperature

Question 5

Which of the following processes can spontaneously occur?

Accepted Answer

A chemical reaction with a negative change in free energy

Answer

Heat transfer from a hot to a cold object

Answer

Water freezing at room temperature

Answer

A ball rolling up a hill

Question 6

Consider two identical systems at the same temperature. Which system will have higher entropy?

Accepted Answer

The system with a larger volume

Answer

The system with a smaller number of particles

Answer

The system with a higher pressure

Answer

Both systems will have the same entropy

Question 7

Which of the following is the SI unit for entropy?

Accepted Answer

Joules per Kelvin (J/K)

Answer

Kelvin per Joule (K/J)

Answer

Joules (J)

Answer

Kelvin (K)

Question 8

During an isentropic process, which property remains constant?

Accepted Answer

Entropy

Answer

Temperature

Answer

Energy

Answer

Volume

Question 9

According to the Second Law of Thermodynamics, in an isolated system, which quantity continuously increases?

Accepted Answer

Entropy

Answer

Energy

Answer

Temperature

Answer

Pressure

Question 10

Which of the following is NOT a characteristic of reversible processes?

Accepted Answer

Presence of heat transfer

Answer

No entropy generation

Answer

Complete return to the initial state

Answer

Equilibrium conditions

Question 11

Which process is typically associated with a decrease in entropy?

Accepted Answer

Crystallization

Answer

Melting

Answer

Evaporation

Answer

Combustion

Question 12

In thermodynamics, the mathematical expression for the change in entropy is given by the integral of what quantity divided by temperature?

Accepted Answer

Heat transfer (dQ)

Answer

Work done (dW)

Answer

Internal energy change (dU)

Answer

Volume change (dV)

Question 13

What is the SI unit of entropy?

Accepted Answer

Joule per Kelvin

Answer

Joule

Answer

Kelvin

Answer

Watt

Question 14

In a reversible process, what is the change in the system's entropy?

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Depends on the path taken

Question 15

Which of the following best describes the Second Law of Thermodynamics?

Accepted Answer

The entropy of the universe always increases.

Answer

The total entropy of an isolated system always decreases.

Answer

The entropy of a system can never decrease.

Answer

The Second Law does not apply to non-isolated systems.

Question 16

A heat engine operates between two reservoirs at different temperatures, T1 and T2, with T1 > T2. What is the maximum possible efficiency of the engine?

Accepted Answer

(T1 - T2)/T1

Answer

100%

Answer

(T1 - T2)/T2

Answer

(T2 - T1)/T1

Question 17

Consider a system undergoing a spontaneous process. What can be said about the entropy change and Gibbs free energy change of the system?

Accepted Answer

Entropy increases, Gibbs free energy decreases.

Answer

Entropy decreases, Gibbs free energy increases.

Answer

Entropy and Gibbs free energy change remain constant.

Answer

Entropy decreases, Gibbs free energy decreases.

Question 18

What is the physical interpretation of entropy in terms of a system's disorder?

Accepted Answer

It measures the likelihood of a particular arrangement of molecules in the system.

Answer

It indicates the system's ability to transfer heat.

Answer

It describes the direction of spontaneous processes.

Answer

It determines the system's temperature.

Question 19

Entropy measures the degree of:

Accepted Answer

Randomness in a system

Answer

Energy in a system

Answer

Heat transfer between systems

Answer

Work done on a system

Question 20

Which process is considered non-spontaneous?

Accepted Answer

Charging of a battery with an external power source

Answer

Heat transfer from a hot to a cold object

Answer

Expansion of a gas into a vacuum

Answer

Melting of ice at room temperature

Question 21

In a reversible process, the entropy change of the system is:

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Dependent on initial and final states

Question 22

The Clausius statement of the Second Law implies that:

Accepted Answer

Heat flows spontaneously from hot to cold reservoirs

Answer

Heat flows spontaneously from cold to hot reservoirs

Answer

Work can be converted into heat but not vice versa

Answer

Entropy decreases in reversible processes

Question 23

A consequence of the Second Law of Thermodynamics is that the universe:

Accepted Answer

Becomes increasingly disordered

Answer

Becomes increasingly ordered

Answer

Maintains a constant level of order and disorder

Answer

Experiences random fluctuations in order and disorder

Question 24

Which of the following is a valid interpretation of the concept of entropy?

Accepted Answer

A measure of the disorder or randomness of a system

Answer

The amount of heat energy in a system

Answer

The temperature of a system

Answer

The pressure of a system

Question 25

According to the Second Law of Thermodynamics, which of the following is true about the spontaneous direction of processes in isolated systems?

Accepted Answer

They proceed towards states of higher entropy.

Answer

They proceed towards states of lower entropy.

Answer

They proceed towards states of constant entropy.

Answer

The direction is unpredictable without further information.

Question 26

Which of the following is a consequence of the Second Law of Thermodynamics?

Accepted Answer

Heat cannot spontaneously flow from a colder reservoir to a hotter reservoir.

Answer

Machines can convert 100% of heat energy into work.

Answer

Entropy always decreases in non-isolated systems.

Answer

Energy can be created or destroyed during any process.

Question 27

What is the entropy change for a closed system undergoing an isothermal reversible process?

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Indeterminate

Question 28

Which of the following statements is equivalent to the Clausius statement of the Second Law of Thermodynamics?

Accepted Answer

Heat cannot pass spontaneously from a colder to a hotter body.

Answer

The total entropy of an isolated system always decreases.

Answer

No perpetual motion machine of the first kind is possible.

Answer

The efficiency of a heat engine can never exceed 100%.

Question 29

In a closed system, what is the condition for entropy production?

Accepted Answer

Always positive, indicating an increase in entropy

Answer

Always negative, indicating a decrease in entropy

Answer

Zero, indicating no change in entropy

Answer

Indeterminate, depending on the specific process

Question 30

What is the physical interpretation of entropy?

Accepted Answer

Quantitative measure of disorder

Answer

Measure of energy in transit

Answer

Degree of reversibility of a process

Answer

Capacity of a system to absorb heat

Question 31

The central tenet of the Second Law of Thermodynamics is that:

Accepted Answer

The total entropy of an isolated system remains constant or increases

Answer

Energy can be created or destroyed

Answer

All processes are ideally reversible

Answer

Heat engines can operate with 100% efficiency

Question 32

The entropy change of a system during an irreversible process is:

Accepted Answer

Always positive

Answer

Always zero

Answer

Always negative

Answer

Unpredictable

Question 33

Which quantity serves as a measure of the disorder of a system?

Accepted Answer

Entropy

Answer

Enthalpy

Answer

Gibbs free energy

Answer

Internal energy

Question 34

According to the Third Law of Thermodynamics:

Accepted Answer

The entropy of a perfect crystal at absolute zero is zero

Answer

Entropy of a system approaches infinity as temperature approaches infinity

Answer

The Second Law of Thermodynamics does not apply to isolated systems

Answer

All processes are ideally reversible

Question 35

Which of the following statements best defines entropy?

Accepted Answer

A measure of the randomness or disorder in a system

Answer

The amount of heat a system can absorb at a specific temperature

Answer

The capacity of a system to perform work

Answer

The total energy contained within a closed system

Question 36

For a closed system undergoing a spontaneous process, which statement is accurate?

Accepted Answer

The surroundings' entropy increases

Answer

The system's entropy decreases

Answer

The system's free energy decreases

Answer

The system's enthalpy decreases

Question 37

For an ideal gas undergoing an isentropic process, which of the following statements is true?

Accepted Answer

Entropy change is zero

Answer

Temperature change is zero

Answer

Pressure change is zero

Answer

Volume change is zero