Answer: The percent yield of the reaction is 77.0 %
Explanation:




According to stoichiometry:
2 moles of
produces = 2 moles of 
2.18 moles of
is produced by=
of 
Mass of
=
percent yield =
Answer: The mass of the sample is 1264.800 kg.
Explanation:
Mass of the piece of copper = m
Volume of the copper price = 



m = 1,264,800 g = 1,264.800 kg (1 kg = 1000 g)
The mass of the sample is 1264.800 kg.
Metals is the right answer.