Em tham khảo nha :
\(\begin{array}{l}
1)\\
4Na + {O_2} \to 2N{a_2}O\\
{N_{Na}}:{N_{N{a_2}O}} = 2:1\\
{P_2}{O_5} + 3{H_2}O \to 2{H_3}P{O_4}\\
{N_{{P_2}{O_5}}}:{N_{{H_3}P{O_4}}} = 1:2\\
2HgO \to 2Hg + {O_2}\\
{N_{Hg}}:{N_{{O_2}}} = 2:1\\
2Fe{(OH)_3} \to F{e_2}{O_3} + 3{H_2}O\\
{N_{F{e_2}{O_3}}}:{N_{{H_2}O}} = 1:3\\
2)\\
4Fe{S_2} + 11{O_2} \to 8S{O_2} + 2F{{\rm{e}}_2}{O_3}\\
2Fe{(OH)_3} \to F{e_2}{O_3} + 3{H_2}O\\
S{O_2} + 2{H_2}S \to 3S + 2{H_2}O\\
3F{e_2}{O_3} + {H_2} \to 2F{e_3}{O_4} + {H_2}O\\
FeS + 2HCl \to FeC{l_2} + {H_2}S\\
4Fe{(OH)_2} + {O_2} + 2{H_2}O \to 4Fe{(OH)_3}\\
FeC{l_2} + 2NaOH \to Fe{(OH)_2} + 2NaCl\\
2Ag + 2{H_2}S{O_4} \to A{g_2}S{O_4} + S{O_2} + 2{H_2}O\\
F{e_2}{O_3} + 6HN{O_3} \to 2Fe{(N{O_3})_2} + 3{H_2}O
\end{array}\)
\(\begin{array}{l}
4N{H_3} + 5{O_2} \to 4NO + 6{H_2}O\\
C{O_2} + 2NaOH \to N{a_2}C{O_3} + {H_2}O\\
2Na + 2{H_2}O \to 2NaOH + {H_2}\\
Cu + 2{H_2}S{O_4} \to CuS{O_4} + S{O_2} + {H_2}O\\
F{e_3}{O_4} + 4{H_2} \to 3Fe + 4{H_2}O\\
4N{O_2} + {O_2} + 2{H_2}O \to 4HN{O_3}
\end{array}\)