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Thermodynamics: work in a free expansion process A gas expands freely against vacuum (no external resistance) from one volume to a larger volume. What is the work done by the gas in free expansion?

Q: Thermodynamics: work in a free expansion process A gas expands freely against vacuum (no external resistance) from one volume to a larger volume. What is the work done by the gas in free expansion?

Given Free expansion: external pressure = 0. Concept/Approach Boundary work: W = ∫ pext dV. In free expansion, pext = 0 ⇒ W = 0. Final Answer Zero

Difficulty: Easy

Zero
Minimum (negative)
Maximum (positive)
Positive but finite

Correct Answer: Zero

Explanation:

Given

Free expansion: external pressure = 0.

Concept/Approach

Boundary work: W = ∫ p_ext dV. In free expansion, p_ext = 0 ⇒ W = 0.

Final Answer
Zero

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