Elements/Metric Prefixes/Polyatomic Ion Formulas

ammonium

NH₄⁺

acetate

C₂H₃O₂^-

carbonate

CO₃^2-

hydrogen carbonate

HCO₃^-

chromate

CrO₄^2-

dichromate

CR₂O₂^2-

chlorate

ClO₃^-

perchlorate

ClO₄^-

chlorite

ClO₂^-

hypochlorite

ClO^-

cyanide

CN^-

hydroxide

OH^-

nitrate

NO₃^-

nitrite

NO₂^-

phosphate

PO₄^3-

hydrogen phosphate

HPO₄^2-

phosphite

PO₃^3-

sulfate

SO₄^2-

hydrogen sulfate

HSO₄^-

sulfite

SO₃^2-

soluble, no exceptions

NO₃^-, C₂H₃O₂^-

soluble except with Ag, Hg, and Pb

Cl^-, Br^-, I^-,

soluble except with Sr, Ba, Hg, and Pb

SO₄^2-

insoluble except with NH₄⁺, alkali metal cations, Ca, Sr, or Ba

S^2-

insoluble except with NH₄⁺ and alkali metal cations

CO₃^2-, PO₄^3-

insoluble except with alkali metal cations, Ca, Sr, or Ba

OH^-

strong acids

HNO₃, H₂SO₄, HClO₄, HCl, HBr, HI

strong bases

LiOH, NaOH, KOH etc. BaOH₂, SrOH₂, CaOH₂ (aka soluble hydroxides)