IMAT 2011 Q63 [Yield of Copper]

8.0g of copper oxide is reduced to 5.6g of copper using hydrogen gas.

[relative atomic mass: Cu=64, O=16]
{CuO + H_2 → Cu + H_2O}

What is the yield of copper as a percentage of the theoretical maximum?

A. 14.3%
B. 43.9%
C. 56.0%
D. 70.0%
E. 87.5%