Thermodynamics: Entropy

“Heat (Q)” is a path function and it cannot be a state function in any case.

• True

• False

Which of the following statements about the First Law of Thermodynamics is incorrect?

• Energy cannot be created or destroyed, only transferred or converted.

• The internal energy of a system always remains constant.

• Heat and work are two different ways to transfer energy.

• A system can gain energy from heat while doing work on its surroundings.

Which of the following statements about the Carnot cycle is incorrect?

• The Carnot cycle is the most efficient cycle operating between two given temperature reservoirs.

• No real engine can be more efficient than a Carnot engine operating between the two different temperatures.

• The efficiency of a Carnot engine depends only on the temperatures of the heat source and sink.

• A real engine can achieve Carnot efficiency if it minimizes friction and operates very slowly

Which of the following correctly describes the Clausius inequality?

• For a cyclic process, the total entropy change of the system must be zero.

• The cyclic integral of δQ/T is always greater than or equal to zero, with equality holding only for reversible cycles.

• The Clausius inequality applies only to Carnot cycles.

• The entropy of the universe remains constant for all thermodynamic processes.

What is entropy in thermodynamics?

• Entropy is a measure of temperature in thermodynamics.

• Entropy is a measure of pressure in thermodynamics.

• Entropy in thermodynamics is a measure of the disorder or randomness in a system.

• Entropy is a measure of energy in thermodynamics.

Which of the following statements correctly describes the relationship between entropy and the Second Law of Thermodynamics?

• The entropy of a closed system always increases over time.

• The Second Law states that the entropy of an isolated system never decreases and either increases or remains constant.

• Entropy is always conserved in any thermodynamic process.

• A reversible process causes the total entropy of the universe to increase.

What is the formula to calculate entropy change in a system?

• ΔS = Qrev / T

• ΔS = Q / V

• ΔS = Q / T

• ΔS = Q / P

Discuss the concept of reversible and irreversible processes in terms of entropy.

• Reversible processes maintain constant entropy, while irreversible processes lead to an increase in entropy.

• Irreversible processes maintain constant entropy

• Reversible processes lead to a decrease in entropy

• Entropy remains unchanged in both reversible and irreversible processes

Which of the following statements about entropy is incorrect?

• Entropy in an isolated system never decreases.

• Entropy is a measure of disorder, but it also relates to the number of microstates.

• A process with increasing entropy is always spontaneous.

• The entropy of a system can decrease as long as the total entropy of the universe increases.

Which of the following is true regarding entropy change in Carnot and irreversible cycles?

• In a Carnot cycle, the total entropy change of the system and surroundings is positive.

• In an irreversible cyclic process, the total entropy change of the system is greater than zero.

• For any cycle, the system returns to its initial state, so the entropy change of the system is zero.

• The total entropy change in a Carnot cycle is greater than that in an irreversible cycle.