When does entropy decrease?
Understand the Problem
The question is asking about the circumstances under which entropy, a measure of disorder or randomness in a system, may decrease. This involves understanding thermodynamics and the second law, which generally states that the entropy of an isolated system tends to increase over time, but there are specific scenarios and conditions under which entropy can decrease locally.
Answer
When volume decreases or fewer molecules are produced in a reaction.
Entropy decreases when the volume decreases or when during a reaction the number of product molecules is lower than the number of reactant molecules.
Answer for screen readers
Entropy decreases when the volume decreases or when during a reaction the number of product molecules is lower than the number of reactant molecules.
More Information
Entropy is a measure of disorder or randomness in a system. While the second law of thermodynamics states that the total entropy of an isolated system can never decrease over time, local decreases in entropy can occur.
Tips
A common mistake is to think that entropy can never decrease. While the total entropy of the universe tends to increase, local decreases are possible and occur frequently.
Sources
- When does entropy increase and when does it decrease? - Socratic - socratic.org
- Entropy Changes in Reactions - Chemistry LibreTexts - chem.libretexts.org
