3.溴的制备 CL+2Br-== Br+2cI- 3Br +3NaCO,== 5NaBr+HBrO3+3CO,1 5Br-+BrO,+6H+=- 3Br2+3H2O 4.碘的制备 Ch+2Nal == nAcl+l 2Nal+3h,So+MnO, =-2NaHSO4++2H2O+MnSO4 I+5CL+6HO 此二反应要避免 2IO2-+10Cl1-+12H 使用过量氧化剂3. 溴的制备 Cl2+2Br – == Br2+2Cl– 3Br2+3NaCO3 == 5NaBr+HBrO3+3CO2 ↑ 5Br – + BrO3 – + 6H+ == 3Br2+3H2O 4. 碘的制备 Cl2+2NaI == 2NaCl+I2 I 2+5Cl2+6H2O == 2IO3 – +10Cl – +12H+ 2NaI+3H2SO4+MnO2 ==2NaHSO4+I2+2H2O+MnSO4 此二反应要避免 使用过量氧化剂