Answer: 1.21 moles to 3 sig figs
Explanation:
All gases occupy 22.4 liters per mole of gas at STP.
(22.4 L/mole) at STP is an imoportant conversion factor. It helps to remember it and is good cocktail party conversation, for the right crowd.
(27.2L CO2 gas)/(22.4 L/mole) = 1.21 moles to 3 sig figs