\(\begin{array}{l}
Fe + {H_2}S{O_4} \to FeS{O_4} + {H_2}\\
FeS{O_4} + BaC{l_2} \to FeC{l_2} + BaS{O_4}\\
FeC{l_2} + 2AgN{O_3} \to Fe{(N{O_3})_2} + 2AgCl\\
Fe{(N{O_3})_2} \to Fe + 2N{O_2} + {O_2}\\
3Fe + 2{O_2} \to F{e_3}{O_4}\\
F{e_3}{O_4} + 8HCl \to 2FeC{l_3} + FeC{l_2} + 4{H_2}O\\
FeC{l_2} + Mg \to MgC{l_2} + Fe
\end{array}\)