Fe + 2HCl → FeCl2 + H2 (1)
2Fe + 6H2SO4 (đnóng) → Fe2(SO4)3 + 3SO2↑ + 6H2O (2)
Cu + 2H2SO4 (đnóng) → CuSO4 + SO2↑ + 2H2O (3)
\(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
\(n_{SO_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\)
Theo PT1: \(n_{Fe}=n_{H_2}=0,2\left(mol\right)\)
\(\Rightarrow m_{Fe}=0,2\times56=11,2\left(g\right)\)
Theo PT2: \(n_{SO_2}=\dfrac{3}{2}n_{Fe}=\dfrac{3}{2}\times0,2=0,3\left(mol\right)\)
\(\Rightarrow n_{SO_2}\left(3\right)=0,4-0,3=0,1\left(mol\right)\)
Theo PT3: \(n_{Cu}=n_{SO_2}=0,1\left(mol\right)\)
\(\Rightarrow m_{Cu}=0,1\times64=6,4\left(g\right)\)
\(\Rightarrow a=m_{Fe}+m_{Cu}=11,2+6,4=17,6\left(g\right)\)
