Polyatomic Ions to Memorize!

PREFIXES AND SUFFIXES (What they mean): -ate “most common variety” -ide only one kind of atom in the anion -ite one less oxygen atom than “ate” variety (same charge) thio- one oxygen atom replaced by S Per- one more oxygen atom than in “ate” variety (same charge) bi- one H+ added to divalent anion Hypo- one less oxygen atom than in “ite” variety (same charge) di- two

Ammonium Ion

NH₄⁺

Acetate Ion

C₂H₃O₂⁻

Carbonate Ion

CO₃²⁻

Cyanide Ion

CN⁻

Cyanate

OCN^-

Hydroxide Ion

OH⁻

Nitrate Ion

NO₃⁻

Nitrite Ion

NO₂⁻

Sulfate Ion

SO₄²⁻

Sulfite Ion

SO₃²⁻

Phosphite Ion

PO₃³⁻

Phosphate Ion

PO₄³⁻

Perchlorate Ion

ClO₄⁻

Chlorate Ion

ClO₃⁻

Permanganate

MnO₄⁻

Hydrogen Carbonate Ion (Bicarbonate)

HCO₃⁻

Dichromate Ion

Cr₂O₇²⁻

Chromate

CrO₄²⁻

(Mono)Hydrogen Phosphate

HPO₄²⁻

Dihydrogen Phosphate

H₂PO₄⁻

Hypochlorite

ClO⁻

Chlorite

ClO₂⁻

Hydrogen Sulfate (Bisulfate)

HSO₄⁻

Hydrogen Sulfite (Bisulfite)

HSO₃⁻

Peroxide

O₂²⁻

Thiocyanate

SCN^-

Bisulfide

HS^-

Hypobromite

BrO^-

Bromite

BrO₂^-

Bromate

BrO₃^-

Perbromate

BrO₄^-

Hypoiodite

IO^-

Iodite

IO₂^-

Iodate

IO₃^-

Periodate

IO₄^-

Thiosulfate

S₂O₃^2-

Oxalate

C₂O₄^2-

Arsenate

AsO₄^3-

Borate

BO_3^3-