\(n_{H_2}=\dfrac{11,2}{22,4}=0,5mol\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
0,5 0,5
\(m_{Fe}=0,5\cdot56=28\left(g\right)\Rightarrow\%m_{Fe}=\dfrac{28}{40}\cdot100\%=70\%\)
\(\Rightarrow\%m_{Cu}=100\%-70\%=30\%\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\\ n_{H_2}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\\ n_{Fe}=n_{H_2}=0,5\left(mol\right)\\ \%m_{Fe}=\dfrac{0,5.56}{40}.100=70\%\\ \%m_{Cu}=100-70=30\%\)