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?
Mechanical Engineering
Thermodynamics
Difficulty: Easy
Choose an option
-
AZero
-
BMinimum (negative)
-
CMaximum (positive)
-
DPositive but finite
Answer
Correct Answer: Zero
Explanation
Given
- Free expansion: external pressure = 0.
Concept/Approach
- Boundary work: W = ∫ pext dV. In free expansion, pext = 0 ⇒ W = 0.
Final AnswerZero