A2L Item 115

Goal: Reasoning about temperature.

Source: UMPERG-ctqpe186

Two moles of an ideal gas fill a volume of 10 liters with a pressure of
2.4 atm. The gas is thermally insulated from the surroundings. A
membrane is broken which allows the gas to expand into the new volume
which is 3 times as large as the old volume. The new temperature is …

  1. The same as before.
  2. Lower than before.
  3. Higher than before.
  4. Cannot be determined.

Commentary:

Answer

(1) Students may erroneously apply prior knowledge that gas cools as it
expands. Some will likely think that the answer cannot be determined
without more information.