a) \(Fe\left(OH\right)^3+H_2SO_4\rightarrow Fe_x\left(SO\right)_y+H_2O\)
\(Fe\left(OH\right)_3\Rightarrow y=3\)
\(H_2SO_4\Rightarrow x=2\)
Vậy : \(Fe\left(OH\right)^3+H_2SO_4\rightarrow Fe_2\left(SO\right)_3+H_2O\)
b) \(Al+HCl\rightarrow Al_xCl_y+H_2\)
\(\left\{{}\begin{matrix}Al:HoátrịIII\Rightarrow y=3\\Cl:HoátrịI\Rightarrow x=1\end{matrix}\right.\)
Vậy : \(Al+HCl\rightarrow AlCl_3+H_2\)