The balanced chemical equation for the reaction that forms CaO and CO2 is:
CaCO3(s) → CaO(s) + CO2(g)
According to the equation, 1 mole of CaCO3 produces 1 mole of CaO and 1 mole of CO2.
Therefore, if 10.0 moles of CO2 are produced, it means that 10.0 moles of CaO are also produced since the reaction stoichiometry is 1:1.
So the answer is 10.0 moles of CaO.