Nomenclature: Rules for Naming Simple Acids and Oxyacids

How do you recognize that something is an acid? The acids that we will be concerned with naming are really just a special class of ionic compounds where the cation is always H+. By convention, cations are written first in ionic formulas. So if the formula has hydrogen written first, then this usually indicates that the hydrogen is an H+ cation and that the compound is an acid. When dissolved in water, acids produce H+ ions (also called protons, since removing the single electron from a neutral hydrogen atom leaves behind one proton). If the counterion (the anion) to H+ in the acid is a polyatomic ion that contains oxygen (like NO2- or PO43-), the acid is called an oxyacid and is named using the rules provided below. If the anion does not contain oxygen, as in the case of F- or the polyatomic ion CN-, then a different set of rules are used for naming the acid.

Rules for Naming Oxyacids (anion contains the element oxygen):


Rules for Naming Acids that Do Not Contain Oxygen in the Anion:




Test your knowledge of nomenclature with the Nomenclature Assignment.