Some Common Polyatomic Ions




NH4+ Ammonium

Hg22+ Mercury (I) or Mercurous






C2H3O2- Acetate

CO32- Carbonate

AsO43- Arsenate

Fe(CN)64- Hexacyanoferrate (II) or Ferrocyanide

AlO2- Aluminate

CrO42- Chromate

AsO33- Arsenite

HCO3- Bicarbonate, Hydrogen Carbonate

Cr2O72- Dichromate

Fe(CN)63- Hexacyanoferrate (III) or Ferricyanide

BrO3- Bromate

C2O42- Oxalate

PO43- Phosphate

ClO4- Perchlorate

O22- Peroxide

PO33- Phosphite

ClO3- Chlorate


ClO2- Chlorite

SO42- Sulfate

ClO- Hypochlorite

SO32- Sulfite

CrO2- Chromite

C4H4O62- Tartrate

CN- Cyanide

S2O32- Thiosulfate

OH- Hydroxide


IO3- Iodate.

NO3- Nitrate

NO2- Nitrite

MnO4- Permanganate

Consult your periodic table for a more complete list of oxidation states of other monoatomic ions