Em tham khảo nha :
\(\begin{array}{l}
a)\\
8Al + 15{H_2}S{O_4} \to 4A{l_2}{(S{O_4})_3} + 3{H_2}S + 12{H_2}O\\
Al \to A{l^{ + 3}} + 3e\\
{S^{ + 6}} + 8e \to {H_2}S\\
b)\\
3F{e_x}{O_y} + 2(y - x)Al \to 3xFeO + (y - x)A{l_2}{O_3}\\
F{e^{ + \dfrac{{2y}}{x}}} + (\dfrac{{2y}}{x} - 2)e \to FeO\\
Al \to A{l^{ + 3}} + 3e\\
c)\\
4Mg + 10HN{O_3} \to 4Mg{(N{O_3})_2} + N{H_4}N{O_3} + 3{H_2}O\\
Mg \to M{g^{ + 2}} + 2e\\
{N^{ + 5}} + 8e \to {N^{ - 3}}
\end{array}\)