- Điều chế bằng cách Cl2+ H2:
2KCl+ 2H2O $\buildrel{{đpmn}}\over\longrightarrow$ 2KOH+ H2+ Cl2
CaCl2+ 2H2O $\buildrel{{đpmn}}\over\longrightarrow$ Ca(OH)2+ H2+ Cl2
2KCl $\buildrel{{đpnc}}\over\longrightarrow$ 2K+ Cl2
CaCl2 $\buildrel{{đpnc}}\over\longrightarrow$ Ca+ Cl2
2KOH+ H2SO4 -> K2SO4+ 2H2O
Ca(OH)2+ H2SO4 -> CaSO4+ 2H2O
2H2O $\buildrel{{đpdd}}\over\longrightarrow$ 2H2+ O2
MnO2+ 4HCl -> MnCl2+ Cl2+ 2H2O
H2+ Cl2 $\buildrel{{askt}}\over\longrightarrow$ 2HCl
- Điều chế bằng cách muối clorua+ H2SO4:
KCl+ H2SO4 -> KHSO4+ HCl
CaCl2+ H2SO4 -> CaSO4+ 2HCl
