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 CO3(2-) 2 NO3(-) 3 HCO3(-) 4 CrO4(2-) 5 NO2(-) 6 PO4(3-) 7 CH3COO(-) 8 NH4(+) 9 ClO2(-) 10 CN(-) 11 ClO4(-) 12 ClO(-) 13 MnO4(-) 14 O2(2-) 15 HSO4(-) 16 SO4(2-) 17 H2PO4(-) 18 HPO4(2-) 19 Hg2(2+) 20 ClO3(-) 21 OH(-) 22 SO3(2-) 23 H3O(+) 24 Cr2O7(2-) Carbonate Dihydrogen Phosphate Chromate Hydroxide Peroxide Nitrite Hydrogen sulfate/bisulfate Dichromate Sulfite Mercury(I) Perchlorate Phosphate Sulfate Ammonium Hydrogen Phosphate Acetate Permanganate Hydronium Bicarbonate/Hydrogen Carbonate Cyanide Hypochlorite Nitrate Chlorite Chlorate