1)
$Ba + 2H_2O \to Ba(OH)_2 + H_2$
$Ba(OH)_2 + CO_2 \to BaCO_3 + H_2O$
$BaCO_3 + 2HCl \to BaCl_2 + CO_2 + H_2O$
$BaCl_2 \xrightarrow{đpnc} Ba + Cl_2$
2)
$2Na + 2H_2O \to 2NaOH + H_2$
$2NaOH + CO_2 \to Na_2CO_3 + H_2O$
$Na_2CO_3 + 2HCl \to 2NaCl + CO_2 + H_2O$
$2NaCl \xrightarrow{đpnc} 2Na + Cl_2$