[SOLVED] Distinguishing Between CO2 and Ar Explain how you would distinguish between argon gas and carbon dioxide gas My first thought was to boil some water to remove any dissolved gases, and then pass the two gases through samples of the water. The CO2 would react to form a weak solution of carbonic acid, while the argon does nothing. The formation of carbonic acid could be identified with the use of a suitable indicator. On second thought, id probably pass the gases through limewater and watch for the formation of a precipitate, however, in an exam, i probably would have ended up leaving my first answer. My question is: Is my first method correct, would it work? And would it be practical? Thanks, Dan.