(1) Cl2+ H2 $\buildrel{{as}}\over\longrightarrow$ 2HCl
(2) MnO2+ 4HCl -> MnCl2+ Cl2+ 2H2O
(3) Cl2+ 2Na -> 2NaCl
(4) 2NaCl $\buildrel{{đpnc}}\over\longrightarrow$ 2Na+ Cl2
(5) NaOH+ HCl -> NaCl+ H2O
(6) NaCl+ H2SO4 $\buildrel{{t^o}}\over\longrightarrow$ NaHSO4+ HCl