Common Polyatomic Ions

NH₄⁺

NH₄⁺

ammonium

H₃O⁺

hydronium

CH₃COO⁻ , CH₃COOH

acetate

acetic acid

CN⁻ , HCN

cyanide

hydrocyanic acid

ClO⁻, HCIO

hypochlorite

hypochlorous acid

ClO₂⁻ , HCIO₂

chlorite

Chlorous acid

ClO₃⁻ , HClO₃

chlorate

chloric acid

NO₂⁻ , HNO₂

nitrite

nitrous acid

NO₃⁻ , HNO₃

nitrate

nitric acid

MnO₄⁻

HMnO₄

permanganate

permanganic acid

CO₃²⁻

H₂CO₃

carbonate

carbonic acid

HCO₃⁻

bicarbonate

CrO₄²⁻

H₂CrO₄

chromate

chromic acid

Cr₂O₇²⁻

H₂Cr₂O₇

dichromate

dichromic acid

O₂²⁻

peroxide

PO₄³⁻

H₃PO₄

phosphate

phosphoric acid

HPO₄²⁻

hydrogen phosphate

H₂PO₄⁻

dihydrogen phosphate

SO₃²⁻

H₂SO₃

sulfite

sulfurous acid

SO₄²⁻

H₂SO₄

sulfate

sulfuric acid

OH⁻

hydroxide

N₃⁻

HN₃

azide

hydrazoic acid

HSO₄⁻

hydrogen sulfate

HSO₃⁻

hydrogen sulfite

ClO₄⁻

HClO₄

perchlorate

perchloric acid