Chemical Names and Formulas

Polyatomic Ions

nitrate (NO3) -1 chromate (CrO4) -2
chlorate (ClO3) -1 dichromate (Cr2O7) -2
sulfate (SO4) -2 phosphate (PO4) -3
carbonate (CO3) -2 acetate (C2H3O2) -1
hydroxide (OH) -1 cyanide (CN) -1
ammonium (NH4) +1    

More Polyatomic Ions

To get -ite, subtract one O from an -ate. Example: sulfate = (SO4) -2, sulfite = (SO3) -2.

To add a hydrogen, increase the charge by one. Example: sulfate = (SO4) -2, hydrogen sulfate = (HSO4) -1.

nitrite (NO2) -1 hydrogen sulfate (HSO4) -1
chlorite (ClO2) -1 hydrogen sulfite (HSO3) -1
sulfite (SO3) -2 bicarbonate (HCO3) -1
phosphite (PO3) -3 hydrogen phosphate (HPO4) -2
hypochlorite (ClO) -1 dihydrogen phosphate (H2PO4) -1
perchlorate (ClO4) -1 oxalate (C2O4) -2
permanganate (MnO4) -1 silicate (SiO3) -2
thiocyanate (SCN) -1 thiosulfate (S2O3) -2