Answer:
False.
Explanation:
Both copper (I) oxide (Cu2O) and copper (II) oxide (CuO) can be reduced to copper metal (Cu) upon heating in the absence of air. Therefore, it is not possible to determine which of the two oxides was initially present based solely on the mass of copper obtained upon reduction.
To determine the identity of the original oxide, additional information would be needed, such as the stoichiometry of the reduction reaction or the identity of any other products formed during the reduction.