A2L Item 090

Goal: Reasoning about adiabatic expansion.

Source: UMPERG

An ideal gas is allowed to expand slowly. The system is thermally

Which statement regarding the final temperature is true?

  1. T’ < T
  2. T’ = T
  3. T’ > T
  4. Not enough information



(1) For adiabatic expansion, TV(γ-1) is constant.
Since the volume increases, the temperature must decrease.

This result can be reasoned by considering the fact that work is done by
the gas. Since there is no heat transfer, the internal energy must
decrease. Since the internal energy of a perfect gas depends only upon
temperature, the temperature must decrease.