Table 2.5: Common Polyatomic Ions

Ion Name Ion Name
Hg22+ Mercury(I) NCS- Thiocyanate
NH4+ Ammonium CO32- Carbonate
NO2- Nitrite HCO3- Hydrogen carbonate (bicarbonate)
NO3- Nitrate ClO- Hypochlorite
SO32- Sulfite ClO2- Chlorite
SO42- Sulfate ClO3- Chlorate
HSO4- Hydrogen sulfate (bisulfate) ClO4- Perchlorate
OH- Hydroxide C2H3O2- Acetate
CN- Cyanide MnO4- Permanganate
PO43- Phosphate Cr2O72- Dichromate
HPO42- Hydrogen phosphate CrO42- Chromate
H2PO4- Dihydrogen phosphate O22- Peroxide
C2O42- Oxalate