Answer:
as we know that CaO +CO2 -------------- CaCO3
and it is given that CaCO3 = 100 grams/1 mole
so first we know that this equation is already balanced ,
according to stoichiometry , CaO = 22.4 litre,
because we know that if one mole of CaCO3 contains 22.4 litre ,
then one mole of CaO will also contain 22.4 litre [volume].
This can be only founded by the help of Stoichiometry.
Step-by-step explanation: