Giả sử có 100 gam quặng
\(m_{Cu}=\dfrac{66,67.100}{100}=66,67\left(g\right)\)
=> \(n_{Cu}=\dfrac{66,67}{64}\left(mol\right)\)
=> \(n_{Cu_2O}=\dfrac{6667}{12800}\left(mol\right)\Rightarrow m_{Cu_2O}=\dfrac{6667}{12800}.144=\dfrac{60003}{800}\left(g\right)\)
=> \(\%m_{Cu_2O}=\dfrac{\dfrac{60003}{800}}{100}.100\%=75,00375\%\)