NaCl->HCl->CuCl2->Cu(OH)2->CuCl2->Cu(NO3)2->Cl2->Br2->I2

\(NaC{l_r} + {H_2}S{O_4}\xrightarrow{{{t^o}}}NaHS{O_4} + HCl\)

\(CuO + 2HCl\xrightarrow{{}}CuC{l_2} + {H_2}O\)

\(CuC{l_2} + 2NaOH\xrightarrow{{}}Cu{(OH)_2} + 2NaCl\)

\(Cu{(OH)_2} + 2HCl\xrightarrow{{}}CuC{l_2} + 2{H_2}O\)

\(CuC{l_2} + 2AgN{O_3}\xrightarrow{{}}AgCl + Cu{(N{O_3})_2}\)

\(Cu{(N{O_3})_2} + 6KCl + 4{H_2}S{O_4}\xrightarrow{{}}CuS{O_4} + 3{K_2}S{O_4} + 3C{l_2} + 2NO + 4{H_2}O\)

\(C{l_2} + 2NaBr\xrightarrow{{}}2NaCl + B{r_2}\)

\(B{r_2} + 2NaI\xrightarrow{{}}2NaBr + {I_2}\)