Here is a list of common anions, their names, and their formulas. Also, there is a PDF table for printing and easy reference. An anion is a chemical species with a net negative electrical charge.
Reading Anion Names and Formulas
By convention, the anion portion of a chemical name or formula follows the cation. For example, in sodium chloride (NaCl), the cation is the sodium ion (Na+) and the anion is the chloride ion (Cl–). Note the electrical charge of a cation or anion follows its chemical formula as a superscript. In sodium hydroxide (NaOH), the cation is the sodium ion (Na+), while the anion is the hydroxide ion (OH–). Cations and anions may consist of single atoms or groups of atoms. In a neutral molecule, the charge of the cation is the same but opposite the charge of the anion.
Anion PDF
The graphic shown above is available as a PNG or as a PDF to download and print. While the list is not as extensive as the one that follows, it groups many of the ions according to their main element on the periodic table.
Table of Common Anions
This table lists common anions by their names, with the anion formula and charge. Anions are grouped according to whether they are simple (one element or monatomic ions), oxoanions (containing oxygen), derived from organic acids, or other types of anions.
| Simple Anions | Formula |
| Hydride | H– |
| Oxide | O2- |
| Fluoride | F– |
| Sulfide | S2- |
| Chloride | Cl– |
| Nitride | N3- |
| Bromide | Br– |
| Iodide | I– |
| Oxoanions | Formula |
| Arsenate | AsO43- |
| Phosphate | PO43- |
| Arsenite | AsO33- |
| Hydrogen Phosphate | HPO42- |
| Dihydrogen Phosphate | H2PO4– |
| Sulfate | SO42- |
| Nitrate | NO3– |
| Hydrogen Sulfate | HSO4– |
| Nitrite | NO2– |
| Thiosulfate | S2O32- |
| Sulfite | SO32- |
| Perchlorate | ClO4– |
| Iodate | IO3– |
| Chlorate | ClO3– |
| Bromate | BrO3– |
| Chlorite | ClO2– |
| Hypochlorite | OCl– |
| Hypobromite | OBr– |
| Carbonate | CO32- |
| Chromate | CrO42- |
| Hydrogen Carbonate or Bicarbonate | HCO3– |
| Dichromate | Cr2O72- |
| Anions from Organic Acids | Formula |
| Acetate | CH3COO– |
| Formate | HCOO– |
| Other Anions | Formula |
| Cyanide | CN– |
| Amide | NH2– |
| Cyanate | OCN– |
| Peroxide | O22- |
| Thiocyanate | SCN– |
| Oxalate | C2O42- |
| Hydroxide | OH– |
| Permanganate | MnO4– |
References
- Masterton, William; Hurley, Cecile (2008). Chemistry: Principles and Reactions. Cengage Learning. ISBN 0-495-12671-3.
- Scerri, E. R. (2007). The Periodic Table, Its Story and Its Significance. Oxford University Press. ISBN 978-0-19-530573-9.
- Sukalyan Dash, Patel, Sabita; Mishra, Bijay K. (2009). “Oxidation by permanganate: synthetic and mechanistic aspects”. Tetrahedron. 65 (4): 707–739. doi:10.1016/j.tet.2008.10.038