a, \(PTHH:Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)
\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)
\(n_{H2}=\frac{2,24}{22,4}=0,1\left(mol\right)=n_{Fe}\)
\(\rightarrow m_{Fe}=0,1.56=5,6\left(g\right)\)
\(\rightarrow m_{Al2O3}=15,8-5,6=10,2\left(g\right)\)
b, \(n_{HCl}=2n_{Fe}+6n_{Fe2O3}=0,8\left(mol\right)\)
\(\rightarrow m_{HCl}=0,8.36,5=29,2\left(g\right)\)
\(\rightarrow C\%_{HCl}=\frac{29,2}{50}.100\%=58,4\%=x\)