a)
\(Fe + 2HCl\xrightarrow{{}}FeC{l_2} + {H_2}\)
\(FeC{l_2} + Pb{(N{O_3})_2}\xrightarrow{{}}Fe{(N{O_3})_2} + PbC{l_2}\)
\(Fe{(N{O_3})_2} + 2NaOH\xrightarrow{{}}Fe{(OH)_2} + 2NaN{O_3}\)
\(Fe{(OH)_2}\xrightarrow{{{t^o}}}FeO + {H_2}O\)
\(FeO + {H_2}\xrightarrow{{{t^o}}}Fe + {H_2}O\)
b)
\(Fe + 2HCl\xrightarrow{{}}FeC{l_2} + {H_2}\)
\(FeC{l_2} + 2NaOH\xrightarrow{{}}Fe{(OH)_2} + 2NaCl\)
\(2Fe{(OH)_2} + {H_2}O + \frac{1}{2}{O_2}\xrightarrow{{}}2Fe{(OH)_3}\)
\(2Fe{(OH)_3} + 3{H_2}S{O_4}\xrightarrow{{}}F{e_2}{(S{O_4})_3} + 6{H_2}O\)
\(3Mg + F{e_2}{(S{O_4})_3}\xrightarrow{{}}2Fe + 3MgS{O_4}\)
c)
\(FeC{l_2} + 2NaOH\xrightarrow{{}}Fe{(OH)_2} + 2NaCl\)
\(Fe{(OH)_2}\xrightarrow{{{t^o}}}FeO + {H_2}O\)
\(FeO + {H_2}S{O_4}\xrightarrow{{}}FeS{O_4} + {H_2}O\)
\(FeS{O_4} + Ba{(N{O_3})_2}\xrightarrow{{}}Fe{(N{O_3})_2} + BaS{O_4}\)
\(Fe{(N{O_3})_2} + Mg\xrightarrow{{}}Mg{(N{O_3})_2} + Fe\)
d)
\(CuC{l_2} + 2NaOH\xrightarrow{{}}Cu{(OH)_2} + 2NaCl\)
\(Cu{(OH)_2}\xrightarrow{{{t^o}}}CuO + {H_2}O\)
\(CuO + {H_2}S{O_4}\xrightarrow{{}}CuS{O_4} + {H_2}O\)
\(Cu{(N{O_3})_2} + Fe\xrightarrow{{}}Fe{(N{O_3})_2} + Cu\)
e)
\(AlC{l_3} + 3NaOH\xrightarrow{{}}Al{(OH)_3} + 3NaCl\)
\(2Al{(OH)_3}\xrightarrow{{{t^o}}}A{l_2}{O_3} + 3{H_2}O\)
\(2A{l_2}{O_3}\xrightarrow{{đpnc}}4Al + 3{O_2}\)
\(Al + 4HN{O_3}\xrightarrow{{}}Al{(N{O_3})_3} + NO + 2{H_2}O\)
\(Al{(N{O_3})_3} + 3NaOH\xrightarrow{{}}Al{(OH)_3} + 3NaN{O_3}\)
