AP Chemistry Polyatomic Ions and Oxidation States

A vocabulary set covering polyatomic ion names and formulas, common ion charges, oxidation states of metals with multiple charges, and essential element symbols/names.

Perchlorate

ClO4−1

Chlorate

ClO3−1

Chlorite

ClO2− charge −1.

Hypochlorite

ClO−1

Dihydrogen phosphate

H2PO4−; add two hydrogens to phosphate; charge becomes −1.

Hydrogen phosphate

HPO4^2−; add one hydrogen to phosphate; charge becomes −2.

Phosphate

PO4^3−; the basic phosphate ion with three oxygens; charge −3.

Hydrogen carbonate (bicarbonate)

HCO3−; hydrogen carbonate ion.

Carbonate

CO3^2−; carbonate ion.

Silicate

SiO3^2−; silicate ion.

Acetate (ethanoate)

CH3COO− or C2H3O2−; acetate ion.

Nitrate

NO3−; nitrate ion.

Nitrite

NO2−; nitrite ion.

Sulfate

SO4^2−; sulfate ion.

Sulfite

SO3^2−; sulfite ion.

Hydrogen sulfate (bisulfate)

HSO4−; hydrogen sulfate ion.

Hydrogen sulfite (bisulfite)

HSO3−; hydrogen sulfite ion.

Thiosulfate

S2O3^2−; thiosulfate ion.

Hydronium

H3O+; hydronium ion.

Ammonium

NH4+; ammonium ion.

Permanganate

MnO4−; permanganate ion.

Chromate

CrO4^2−; chromate ion.

Dichromate

Cr2O7^2−; dichromate ion.

Oxalate

C2O4^2−; oxalate ion.

Cyanide

CN−; cyanide ion.

Cyanate

OCN−; cyanate ion.

Thiocyanate

SCN−; thiocyanate ion.

Iodate

IO3−; iodate ion.

Bromate

BrO3−; bromate ion.

Arsenate

AsO4^3−; arsenate ion.

Hydrogen phosphate (alternative)

HPO4^2−; hydrogen phosphate ion (see above).

Hydroxide

OH−; hydroxide ion.

Hydrogen carbonate (bicarbonate)

HCO3−; bicarbonate ion (see above).

Mercury(I)

Hg2^2+; mercurous ion (two Hg atoms sharing a 2+ charge).

Mercury(II)

Hg2+; mercuric ion.

Copper(I)

Cu+; cuprous ion.

Copper(II)

Cu2+; cupric ion.

Gold(I)

Au+; aurous ion.

Gold(III)

Au3+; auric ion.

Nickel(II)

Ni2+; nickel(II) ion.

Nickel(III)

Ni3+; nickel(III) ion.

Zinc

Zn2+; zinc ion.

Cobalt(II)

Co2+; cobalt(II) ion.

Cobalt(III)

Co3+; cobalt(III) ion.

Cadmium

Cd2+; cadmium ion.

Silver

Ag+; silver ion.

Chromium(II)

Cr2+; chromium in +2 oxidation state.

Chromium(III)

Cr3+; chromium in +3 oxidation state.

Lead(II)

Pb2+; lead in +2 oxidation state.

Lead(IV)

Pb4+; lead in +4 oxidation state.

Iron(II)

Fe2+; iron in +2 oxidation state.

Iron(III)

Fe3+; iron in +3 oxidation state.

Tin(II)

Sn2+; tin in +2 oxidation state.

Tin(IV)

Sn4+; tin in +4 oxidation state.

Copper(I) ion

Cu+; cuprous ion.

Copper(II) ion

Cu2+; cupric ion.

Cadmium ion

Cd2+; cadmium ion.

Magnesium

Mg2+; magnesium ion.

Aluminum

Al3+; aluminum ion.

Zinc ion

Zn2+; zinc ion.

Iron ion

Fe2+ or Fe3+; iron(II) or iron(III) ion.

Nickel ion

Ni2+ or Ni3+; nickel(II) or nickel(III) ion.

Potassium

K+; potassium ion.

Sodium

Na+; sodium ion.

Calcium

Ca2+; calcium ion.

Lead ion

Pb2+ or Pb4+; lead(II) or lead(IV) ion.

Zinc ion (alternate)

Zn2+; zinc ion.

Silver ion (alternate)

Ag+; silver ion.

Hydronium (alternative)

H3O+; hydronium ion.

Hydroxide (alternative)

OH−; hydroxide ion.

Nitrate (alternate)

NO3−; nitrate ion.