List of Common Polyatomic Ions

Ammonium

NH4+

Acetate

CH3CO2–

Oxalate

C2O42–

Hydrogen Oxalate

HC2O4 –

Formate

HCO2 –

Cyanide

CN–

Hydroxide

OH–

Peroxide

O2^2–

Superoxide

O2 –

Nitrate

NO3 –

Nitrite

NO2 –

Sulfate

SO4^2–

Hydrogen Sulfate

HSO4 –

Sulfite

SO3^2–

Hydrogen Sulfite

HSO3 –

Thiosulfate

S2O3^2–

Hydrogen Thiosulfate

HS2O3 –

Phosphate

PO4^3–

Hydrogen Phosphate

HPO4^2–

Dihydrogen Phosphate

H2PO4 –

Carbonate

CO3^2–

Hydrogen Carbonate

HCO3 –

Permanganate

MnO4 –

Chromate

CrO4^2–

Dichromate

Cr2O7^2–

Perchlorate

ClO4 –

Chlorate

ClO3 –

Chlorite

ClO2 –

Hypochlorite

ClO–

Perbromate

BrO4 –

Bromate

BrO3 –

Bromite

BrO2 –

Hypobromite

BrO–

Periodate

IO4 –

Iodate

IO3 –

Iodite

IO2 –

Hypoiodite

IO–