Common Polyatomic Ions and Their Charges
-1 anions
  -2 anions
acetate CH3COO-1      biphosphate HPO4-2
aluminate AlO2-1   carbonate CO3-2
benzoate C7H5O2-1   chromate CrO4-2
bicarbonate HCO3-1
dichromate Cr2O7-2
bismuthate BiO3-1
dioxostannate(II) SnO2-2
bisulphate HSO4-1
germanate GeO3-2
bromite BrO2-1
hexachloropalladate(IV) PdCl6-2
bromate BrO3-1
hexachloroplantinate(IV) PtCl6-2          
chlorate ClO3-1
hexafluorosilicate SiF6-2
cyanate OCN-1
hyponitrite N2O2-2
cyanide CN-1
molybdate MoO4-2
dihydrogen phosphate H2PO4-1
oxalate C2O4-2
formate CHO2-1
peroxide O2-2
hydroxide OH-1
persulphate S2O8-2
hypobromite BrO-1
selenate SeO4-2
iodate IO3-1
selenite SeO3-2
metaphosphate PO3-1
silicate SiO3-2
nitrate NO3-1   sulphate SO4-2
perbromate BrO4-1   sulphite SO3-2
permanganate                    MnO4-1
tartrate C4H4O6-2
perrhenate ReO4-1
tellurate TeO4-2
thiocyanate SCN-1
tetraborate B4O7-2
vanadate VO3-1
tetrachloroplatinate(II) PtCl4-2
  +1 cations 

tetrathionate S4O6-2
ammonium NH4+1
thiosulphate S2O3-2
vandyl(III) VO+1
tungstate WO4-2





+2 cations
   -3 anions
tetraamminecopper(II) Cu(NH3)4+2
arsenate AsO4-3
thiocyaniiron(III) FeSCN+2
arsenite AsO3-3
vanadyl(IV) VO+2
borate BO3-3
uranyl(VI) UO2+2
hexacyanoferrate(III) Fe(CN)6-3



phosphate
PO4-3
-4 anions



hexacyanoferrate(II) Fe(CN)6-4


perxenate XeO6-4


pyrophosphate P2O7-4







-5 anions



tripolyphosphate P3O10-5