Question

Which statement about entropy is incorrect?

• A. Entropy is zero at 0 K (Third Law)
• B. Entropy decreases in spontaneous adiabatic processes
• C. Entropy production is irreversible
• D. Entropy measures energy dispersal

Hint:

In spontaneous adiabatic processes, entropy always increases or stays the same — it never decreases. Be cautious of statements that suggest otherwise.

Answer 1

The Correct Option is B

To analyze which statement about entropy is incorrect, let's review each statement concerning the principles and laws of thermodynamics:

1. Entropy is zero at 0 K (Third Law): According to the Third Law of Thermodynamics, the entropy of a perfect crystal at absolute zero temperature (0 Kelvin) is zero. This is considered a correct statement as it describes the behavior of entropy at 0 K.
2. Entropy decreases in spontaneous adiabatic processes: In thermodynamics, during a spontaneous adiabatic process where no heat is exchanged with the surroundings, the entropy of an isolated system does not decrease. Instead, it generally increases or remains constant according to the Second Law of Thermodynamics. Therefore, this statement is incorrect.
3. Entropy production is irreversible: Entropy production refers to the generation of entropy in a system during irreversible processes. This aligns with the concept that in irreversible processes, entropy of the universe always increases, making this statement correct.
4. Entropy measures energy dispersal: Entropy is often described as a measure of how energy is distributed or spread out in a system. Higher entropy indicates more dispersal and disorder, making this statement correct as well.

Given this analysis, the incorrect statement is: Entropy decreases in spontaneous adiabatic processes.