Matching Pairs Common Polyatomic IonsOnline version Common Polyatomic Ions list from Chemistry - The Molecular Nature of Matter and Change - Third Canadian Edition by Maxwell Vonkeman 1 O2(2-) 2 H2PO4(-) 3 NH4(+) 4 HPO4(2-) 5 PO4(3-) 6 CH3COO(-) 7 NO3(-) 8 SO3(2-) 9 ClO4(-) 10 NO2(-) 11 CrO4(2-) 12 HCO3(-) 13 ClO3(-) 14 MnO4(-) 15 CO3(2-) 16 CN(-) 17 OH(-) 18 Hg2(2+) 19 H3O(+) 20 HSO4(-) 21 SO4(2-) 22 ClO2(-) 23 ClO(-) 24 Cr2O7(2-) Chlorite Hypochlorite Bicarbonate/Hydrogen Carbonate Phosphate Nitrite Sulfate Acetate Chromate Carbonate Nitrate Hydroxide Permanganate Mercury(I) Peroxide Sulfite Hydronium Ammonium Cyanide Hydrogen Phosphate Dichromate Perchlorate Chlorate Hydrogen sulfate/bisulfate Dihydrogen Phosphate