Fe + H2SO4 → FeSO4 + H2 (1)
2Al + 3H2SO4 → Al2(SO4)3 + 3H2 (2)
Cu + H2SO4 → X
Chất rắn không tan là Cu
\(\Rightarrow m_{Al+Fe}=m_{hh}-m_{Cu}=50-22,4=27,6\left(g\right)\)
\(n_{H_2}=\dfrac{1,8}{2}=0,9\left(mol\right)\)
Gọi \(x,y\) lần lượt là số mol của Fe và Al
Theo PT1: \(n_{H_2}=n_{Fe}=x\left(mol\right)\)
Theo PT2: \(n_{H_2}=\dfrac{3}{2}n_{Al}=1,5y\left(mol\right)\)
Ta có: \(\left\{{}\begin{matrix}56x+27y=27,6\\x+1,5y=0,9\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,3\\y=0,4\end{matrix}\right.\)
Vậy \(n_{Fe}=0,3\left(mol\right);n_{Al}=0,4\left(mol\right)\)
a) Theo PT1: \(n_{FeSO_4}=n_{Fe}=0,3\left(mol\right)\)
\(\Rightarrow m_{FeSO_4}=0,3\times152=45,6\left(g\right)\)
Theo PT2:\(n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{2}n_{Al}=\dfrac{1}{2}\times0,4=0,2\left(mol\right)\)
\(\Rightarrow m_{Al_2\left(SO_4\right)_3}=0,2\times317=63,4\left(g\right)\)
\(\Rightarrow m_{m'}=m_{FeSO_4}+m_{Al_2\left(SO_4\right)_3}=45,6+63,4=109\left(g\right)\)
b) Theo PT1: \(n_{H_2SO_4}=n_{Fe}=0,3\left(mol\right)\)
Theo PT2: \(n_{H_2SO_4}=\dfrac{3}{2}n_{Al}=\dfrac{3}{2}\times0,4=0,6\left(mol\right)\)
\(\Rightarrow\Sigma n_{H_2SO_4}=0,3+0,6=0,9\left(mol\right)\)
\(\Rightarrow m_{H_2SO_4}=0,9\times98=88,2\left(g\right)\)
\(\Rightarrow m_{ddH_2SO_4}=\dfrac{88,2}{10\%}=882\left(g\right)\)
