\(\begin{array}{l}
2)\\
a)\,3Fe + 2{O_2} \to F{e_3}{O_4}\\
b)\,S{O_2} + 2NaOH \to N{a_2}S{O_3} + {H_2}O\\
\,\,\,\,\,S{O_3} + {H_2}O \to {H_2}S{O_4}\\
c)\,Cu + 2{H_2}S{O_4} \to CuS{O_4} + S{O_2} + 2{H_2}O\\
\,\,\,\,\,\,C + 2{H_2}S{O_4} \to 2S{O_2} + C{O_2} + 2{H_2}O\\
\,\,\,\,\,\,2FeS{O_4} + 2{H_2}S{O_4} \to F{e_2}{(S{O_4})_3} + S{O_2} + 2{H_2}O\\
d)\,{O_3} + 2Ag \to A{g_2}O + {O_2}\\
\,\,\,\,\,\,{O_3} + 2KI + {H_2}O \to {I_2} + 2KOH + {O_2}\\
e)NaHS{O_4} + NaOH \to N{a_2}S{O_4} + {H_2}O
\end{array}\)
