a) (1) 4HCl + MnO2 → Cl2 + 2H2O + MnCl2
(2) Cl2 + H2 → HCl (điều kiện: ánh sáng)
(3) HCl + NaOH → H2O + NaCl
(4) 2H2O + 2NaCl → Cl2 + H2 + 2NaOH
(5) Cl2 + Cu → CuCl2
b) (1) Fe + 2HCl → FeCl2 + H2
(2) FeCl2 + 2NaOH → NaCl + Fe(OH)2
(3) 2HCl + Fe(OH)2 → FeCl2 + 2H2O
(4) Cl2 + 2FeCl2 → 2FeCl3
(5) 3AgNO3 + FeCl3 → 3AgCl + Fe(NO3)3