Polyatomic Ions: Names, Formulas, and Charges

Acetate

C₂H₃O₂⁻ (or CH₃CO₂⁻), charge -1

Cyanide

CN⁻, charge -1

Cyanate

OCN⁻, charge -1

Thiocyanate

SCN⁻, charge -1

Permanganate

MnO₄⁻, charge -1

Perchlorate

ClO₄⁻, charge -1

Chlorate

ClO₃⁻, charge -1

Chlorite

ClO₂⁻, charge -1

Hypochlorite

ClO⁻, charge -1

Nitrate

NO₃⁻, charge -1

Nitrite

NO₂⁻, charge -1

Sulfate

SO₄²⁻, charge -2

Hydrogen sulfate

HSO₄⁻, charge -1

Sulfite

SO₃²⁻, charge -2

Hydrogen sulfite

HSO₃⁻, charge -1

Phosphate

PO₄³⁻, charge -3

Hydrogen phosphate

HPO₄²⁻, charge -2

Dihydrogen phosphate

H₂PO₄⁻, charge -1

Oxalate

C₂O₄²⁻, charge -2

Carbonate

CO₃²⁻, charge -2

Hydrogen carbonate

HCO₃⁻, charge -1

Chromate

CrO₄²⁻, charge -2

Dichromate

Cr₂O₇²⁻, charge -2

Hydroxide

OH⁻, charge -1

Peroxide

O₂²⁻, charge -2

Ammonium

NH₄⁺, charge +1

Mercury(I)

Hg₂²⁺, charge +2