13Redox/ORP Electrode User Guide
Suitable Titrants Titration Reaction Ref
potassium permanganate
(KMnO4)
5Sb+3 + 2MnO4¯ + 16H+ –›
5Sb+3 + 2Mn+2 + 8H2O
2
sodium bromate (NaBrO3) BrO3¯ + 3As+3 + 6H+ –›
Br¯ + 3As+5 + 3H2O
3
potassium permanganate
(KMnO4)
5H2O2 + 2MnO4¯ + 6H+ –›
5O2 + 2Mn+2 + 8H2O
5
sodium iodide (NaI) in acid solution Cl2 +2I¯ –› I2 +
2Cl¯, In basic solution
2ClO¯ + 2I¯ –› I2 + 2Cl¯ + 2OH¯
1
sodium iodate ( NaIO3) 2I2 + IO3¯ + 5HCN + H+ –›
5ICN + 3H2O
4
sodium thiosulfate
(Na2S2O3)
I2 + 2S2O3 -2 –› 2I¯ + S4O6 -2 3
ceric sulfate [Ce(SO4)2]
(not recommended for
samples containing Cl¯)
Fe+2 + Ce+4 –› Ce+3 + Fe+3 2
potassium dichromate
(K2Cr3O7), recommended
for samples containing Cl¯
Cr2O7 -2 + 6Fe+2 + 14H+ –›
2Cr+3 + 6Fe+3 + 7H2O
3
ferrous sulfate (FeSO4) MnO4¯ + 5Fe+2 + 8H+ –›
Mn+2 + 5Fe+3 + 4H2O
2
potassium permanganate
(KMnO4)
3Mn+2 + 2MnO4¯ + 7H2O –›
5MnO3 + H2O + 4H+
1
ceric sulfate [Ce(SO4)2] Sn+2 + 2Ce+4 –› Sn+4 + 2Ce+3 4
iodine (I2) SO2 + I2 + 2H2O –›
SO4-2 + 2I¯ + 4H+
1
sodium bromate (NaBrO3) BrO3¯ + 3Ti+ 6H+ –›
Br¯ + Ti+3 + 3H2O
3
Iodine (I2) I2 + 2S2O3 -2 –› 2I¯ + S4O63
potassium dichromate
(K2Cr2O7)
3UO+2 + Cr2O7 -2 + 8H+ –›
3UO2 +2 + 2Cr+3 + 4H2O
3
sodium iodate (NaIO3) ZnHg(SCN)4 + 6IO3¯ + 6Cl¯ +
8H+ –› Zn+2 + Hg+2 + 6ICl +
4HCN + 4SO4 -2
2