Difficulty: Easy
Correct Answer: Second law of thermodynamics
Explanation:
Introduction / Context:Thermodynamics summarizes how energy and entropy behave. The phrase “The universe tends toward maximum disorder” is a common, informal paraphrase used in textbooks to introduce entropy and spontaneous processes. Connecting this phrase to the correct law is foundational for chemistry, biology, and physics students.
Given Data / Assumptions:
Concept / Approach:Identify which law addresses entropy and spontaneity. The first law is energy conservation (internal energy changes equal heat plus work). The third law defines absolute zero with entropy approaching a minimum constant for perfect crystals. Only the second law addresses the natural directionality toward higher total entropy.
Step-by-Step Solution:
Recall formal statement: ΔS_universe > 0 for spontaneous processes.Map “maximum disorder” → “maximum entropy.”Conclude: the phrase paraphrases the second law.Verification / Alternative check:Examples: heat flows spontaneously from hot to cold; gases mix irreversibly—both increase entropy of the universe, aligning with the second law.
Why Other Options Are Wrong:
First law: conservation of energy, not directionality.Third law: entropy behavior as T → 0 K, not general spontaneity.Zeroth law: thermal equilibrium and temperature transitivity.Common Pitfalls:Over-literal interpretation of “disorder”; in modern terms, entropy quantifies energy dispersion and accessible microstates, which is more precise.
Final Answer:Second law of thermodynamics.
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