What is the relationship between entropy and disorder?

What is 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 is a measure of how many microscopic configurations are possible for the particles in a system while the overall macroscopic state remains the same. When a system becomes more disordered, there are more ways to arrange its particles without changing what we observe, so the number of microstates increases and entropy increases. A familiar illustration is melting a solid into a liquid or letting a gas mix with another gas—the disorder increases and so does entropy. A perfectly ordered crystal at absolute zero has very few possible microstates, giving it minimal entropy. So, entropy increases as disorder increases. Statements that entropy decreases with more disorder or that it’s maximal for perfect order don’t fit what entropy measures.

Entropy is a measure of how many microscopic configurations are possible for the particles in a system while the overall macroscopic state remains the same. When a system becomes more disordered, there are more ways to arrange its particles without changing what we observe, so the number of microstates increases and entropy increases. A familiar illustration is melting a solid into a liquid or letting a gas mix with another gas—the disorder increases and so does entropy. A perfectly ordered crystal at absolute zero has very few possible microstates, giving it minimal entropy. So, entropy increases as disorder increases. Statements that entropy decreases with more disorder or that it’s maximal for perfect order don’t fit what entropy measures.