Answer:
1 mole of any ideal gas occupies the same volume as one mole of any other ideal gas under the same conditions of temperature and pressure.So 1 L CO2 has same number of moles as 1 L O2 and 1 L N2 etc.This means that, assuming all the gases in air are ideal gases, if CO2 is 4.0 % by volume then it is also 4.0 % by moles, because a volume of each gas has the same number of moles.
Explanation:
