Common Polyatomic Ions

ammonium

NH4^+

acetate

CH3COO^-

carbonate

CO3^2-

hydrogen carbonate(bicarbonate)

HCO3^-

hydroxide

OH^-

nitrite

NO2^-

nitrate

NO3^-

chromate

CrO4^2-

dichromate

Cr2O7^2-

phosphate

PO4^3-

hydrogen phosphate

HPO4^2-

dihydrogen phosphate

H2PO4^-

hypochlorite

ClO^-

chlorite

ClO2^-

chlorate

ClO3^-

perchlorate

ClO4^-

permanganate

MnO4^-

sulfite

SO3^2-

sulfate

SO4^2-

hydrogen sulfite (bisulfite)

HSO3^-

hydrogen sulfate (bisulfate)

HSO4^-

cyanide

CN^-

peroxide

O2^2-

borate

BO3^3-

iodate

IO3^-