List of Common Ions: Polyatomic Cations and Anions

oxalate(anion)

C2O4 2-

acetate

CH3COO 1- or C2H3O2 1-

cyanide(anion)

CN 1-

carbonate(anion)

CO3 2-

hypochlorite

ClO -1

chlorite

ClO2 -1

chlorate

ClO3 -1

perchlorate

ClO4 -1

dichromate

Cr2O7 2-

chromate

CrO4 2-

dihydrogen phosphate

H2PO4 -1

hydronium(cation)

H3O+

hydrogen carbonate

HCO3 -1

hydrogen phosphate

HPO4 2-

hydrogen sulfite

HSO3 -1

hydrogen sulfate

HSO4 -1

permanganate

MnO4 -1

ammonium(cation)

NH4+

nitrite(anion)

NO2 1-

hydroxide(anion)

OH 1-

phosphite(anion)

PO3 3-

phosphate(anion)

PO4 3-

sulfite

SO3 2-

sulfate

SO4 2-