a,
$2Al+3Cl_2\to 2AlCl_3$
$Cu+Cl_2\to CuCl_2$
$2Fe+3Cl_2\to 2FeCl_3$
- Dung dịch $Na_2SO_3$:
$Cl_2+H_2O\rightleftharpoons HCl+HClO$
$Na_2SO_3+2HCl\to 2NaCl+SO_2+H_2O$
- Dung dịch KOH:
$Cl_2+2KOH\to KCl+KClO+H_2O$
b,
$2HCl+CaCO_3\to CaCl_2+CO_2+H_2O$
$KOH+HCl\to KCl+H_2O$
$NaClO+2HCl\to NaCl+Cl_2+H_2O$
$MnO_2+4HCl\to MnCl_2+Cl_2+2H_2O$
$AgNO_3+HCl\to AgCl+HNO_3$
$CuO+2HCl\to CuCl_2+H_2O$
$Mg+2HCl\to MgCl_2+H_2$
$Fe+2HCl\to FeCl_2+H_2$