Which statement best describes the relationship between entropy and disorder?

Which statement best describes the relationship between entropy and disorder?

• A. Entropy decreases as disorder increases
• B. Entropy is unrelated to disorder
• C. Entropy increases as disorder increases
• D. Entropy is maximal for perfectly ordered systems

Answer: (C)

Entropy measures how many microscopic configurations a system can have for a given macroscopic state. When there is more disorder, there are more ways to arrange the particles without changing the overall state, so the number of accessible microstates increases and entropy increases (S = k ln W). This is why increasing disorder, like heating a gas or mixing substances, raises entropy, while a perfectly ordered crystal has very few microstates and thus minimal entropy. So the statement that entropy increases as disorder increases is the best description.

Entropy measures how many microscopic configurations a system can have for a given macroscopic state. When there is more disorder, there are more ways to arrange the particles without changing the overall state, so the number of accessible microstates increases and entropy increases (S = k ln W). This is why increasing disorder, like heating a gas or mixing substances, raises entropy, while a perfectly ordered crystal has very few microstates and thus minimal entropy. So the statement that entropy increases as disorder increases is the best description.