30 Examples of Polyatomic Ions

The polyatomic ions are molecules or sets of atoms covalently bonded that have an electric charge. They are also called molecular ions and act as a single unit. For example: the carbonate ion (CO₃^2-) and the ammonium ion (NH₄⁺).

An ion is an atom or molecule that has lost or gained electrons, and that constitutes a chemical species with a positive or negative electrical charge.

• See also: monatomic ions

Examples of polyatomic ions

1. Carbonate ion (CO₃^2-)
2. Sulfate ion (SO₄^2-)
3. Ammonium ion (NH₄⁺)
4. Hydronium ion (H₃EITHER⁺)
5. Cyanide ion (CN^–)
6. Nitrate ion (NO₃^–)
7. Nitrite ion (NO₂^–)
8. Sulfite ion (SO₃^2-)
9. Phosphate ion (PO₄^3-)
10. Hydrogen sulfate ion (HSO₄^–)
11. Dihydrogenphosphate ion (H₂P.O.₄^–)
12. Hydroxide ion (OH^–)
13. Permanganate ion (MnO₄^–)
14. Perchlorate ion (ClO₄^–)
15. Chlorate ion (ClO₃^–)
16. Chlorite ion (ClO₂^–)
17. Hypochlorite ion (ClO^–)
18. Phosphite ion (PO₃^3-)
19. Hydrogen phosphate ion (HPO₄^2-)
20. Hydrogen carbonate ion (HCO₃^–)
21. Perbromate ion (BrO₄^–)
22. Periodate ion (IO₄^–)
23. Chromate ion (CrO₄^2-)
24. Selenate ion (SeO₄^2-)
25. Hypobromite ion (BrO^–)
26. Phosphonium ion (PH₄⁺)
27. Chloronium ion (H₂CL⁺)
28. Sulfonium ion (H₃Yes⁺)
29. Stbonium ion (SbH₄⁺)
30. Bismuthonium ion (BiH₄⁺)

Anions and polyatomic cations

Polyatomic anions are polyatomic ions that have a negative charge, that is, they are sets of atoms or molecules that have gained electrons. For example: the sulfate ion (SO₄^2-) and the phosphate ion (PO₄^3-).

Polyatomic cations are polyatomic ions that have a positive charge, that is, they are sets of atoms or molecules that have lost electrons. For example: the ammonium ion (MnO₄^–) and the hydronium ion (H₃EITHER⁺).

Nomenclature of polyatomic ions

Nomenclature of polyatomic anions

According to traditional nomenclature rules, polyatomic anions are named as follows:

• Polyatomic anions that do not contain oxygen are named by placing the name of the chemical element with the ending -uro. For example: the cyanide anion (CN^–).
• Polyatomic anions that contain oxygen are defined as “oxoanions.” They are named by placing the name of the chemical element (other than oxygen) that makes them up, with the ending -ate. On the other hand, when the same oxoanion has one less oxygen atom, the -ate ending is changed to -ite. For example: the nitrate oxoanion (NO₃^–) and the nitrite oxoanion (NO₂^–).
• Oxoanions that have added hydrogens are named by placing the word hydrogen before the name of the oxoanion, with prefixes which indicate the amount of added hydrogens. For example: the hydrogen phosphate oxoanion (HPO₄^2-) and the dihydrogenphosphate oxoanion (H₂P.O.₄^–).
• Oxoanions that contain halogens and form a four-membered series are named using prefixes indicating the amount of oxygen. For example: the perchlorate oxoanion (ClO₄^–), chlorate (ClO₃^–), chlorite (ClO₂^–) and hypochlorite (ClO^–).
• The hydroxide oxoanion (OH^–) has the specific ending -ido.

Nomenclature of polyatomic cations

According to Traditional Nomenclature rules, polyatomic cations formed from non-metal atoms are named using the ending -io. For example: the hydronium cation (H₃EITHER⁺) and the ammonium cation (NH₄⁺).

Chemical compounds formed by polyatomic ions

Many chemical compounds Ionics contain polyatomic ions. An ionic chemical compound is a compound formed by a cation and an anion each belonging to different chemical elements that have a high difference in electronegativity between them.

Some examples of ionic chemical compounds that contain polyatomic ions are:

• Sodium carbonate (Na₂CO₃)
• Ammonium sulfate ((NH₄)₂SW₄)
• Calcium sulfate (CaSO₄)
• Sodium hydroxide (NaOH)
• Calcium phosphate (Ca₃(P.O.₄))
• Ammonium chloride ((NH₄)Cl)
• Iron(III) phosphate (FePO₄)

References

• Fandiño, O. H. (2011). Strategy to learn the nomenclature of inorganic acids, salts and monatomic and polyatomic ions. Science and technology, 3(49), 226-228.
• Hill, J. W. (1999). Chemistry for the new millennium. Pearson Education.

Follow with:

• Ionic bonds
• Covalent bonds
• Supersaturated solutions