Common Polyatomic Ions

Diammine silver (I) Ag(NH3)2+

Mercury (I) Hg22+

Ammonium NH4+

Arsenite AsO33-

Arsenate AsO43-

Borate BO33-

Acetate C2H3O2-

CH3COO-

Cyanide CN-

Carbonate CO32-

Hydrogen carbonate HCO3-

Oxalate C2O42-

Hypochlorite ClO-

Chlorite ClO2-

Chlorate ClO3-

Perchlorate ClO4-

Chromate CrO42-

Dichromate Cr2O72-

Hexacyanoferrate (III) Fe(CN)63-

Hexacyanoferrate (II) Fe(CN)64-

Permanganate MnO4-

Manganate MnO42-

Molybdate MoO42-

Amide NH2-

Nitrite NO2-

Nitrate NO3-

Peroxide O22-

Hydroxide OH-

Phosphate PO43-

Hydrogen phosphate HPO42-

Dihydrogen phosphate H2PO4-

Thiocyanate SCN-

Sulfite SO32-

Hydrogen sulfite HSO3-

Sulfate SO42-

Hydrogen sulfate HSO4-

Thiosulfate S2O32-