Common Polyatomic Ions

NH₄+

Ammonium

H₃O+

hydronium

CH₃COO- (or C₂H₃O₂^-)

Acetate

OH-

hydroxide

ClO₃-

Chlorate

ClO₄-

perchlorate

NO₃-

Nitrate

MnO₄-

Permaganate

CO₃^2-

Carbonate

HCO₃^2-

Hydrogen carbonate (or bicarbonate)

Cr₂O₇^2-

dichromate

PO₄^3-

Phosphate

SO₄^2-

sulfate

SO₃^2-

Sulfite

CN-

Cyanide

ClO-

hypochlorite

ClO₂-

Chlorite

No₂-

nitrite

CrO₄^2-

chromate

O₂^2-

peroxide

HPO₄^2-

hydrogen phosphate

H₂PO₄-

dihydrogen phosphate

HSO₄-

hydrogen sulfate (or bisulfate)