Common Anions List and Formulas


Common Anions

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 AnionsFormula
HydrideH
OxideO2-
FluorideF
SulfideS2-
ChlorideCl
NitrideN3-
BromideBr
IodideI
OxoanionsFormula
ArsenateAsO43-
PhosphatePO43-
ArseniteAsO33-
Hydrogen PhosphateHPO42-
Dihydrogen PhosphateH2PO4
SulfateSO42-
NitrateNO3
Hydrogen SulfateHSO4
NitriteNO2
ThiosulfateS2O32-
SulfiteSO32-
PerchlorateClO4
IodateIO3
ChlorateClO3
BromateBrO3
ChloriteClO2
HypochloriteOCl
HypobromiteOBr
CarbonateCO32-
ChromateCrO42-
Hydrogen Carbonate or BicarbonateHCO3
DichromateCr2O72-
Anions from Organic AcidsFormula
AcetateCH3COO
FormateHCOO
Other AnionsFormula
CyanideCN
AmideNH2
CyanateOCN
PeroxideO22-
ThiocyanateSCN
OxalateC2O42-
HydroxideOH
PermanganateMnO4

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