Answer:
309 liters
Step-by-step explanation:
A wonderful constant within the gas laws states that 1 mole of any gas occupies 22.4 liters at STP. ANY gas. Make that into a conversion factor you can use at your next social gathering if you want to annoy some friends:
(22.4L/1 mole) for any gas at STP.
Use that factor to find the answer:
(13.8 moles)(22.4L/1 mole) = 309 liters