The most common bases are those included by the Classical Theory of Acids and Bases; that is, they are hydroxyl ion (OH -1) donors. Thus most of the bases are composed of the hydroxyl radical combined with a metallic cation.
The names for these bases are made by writing the name of the cation followed by "hydroxide." It is not normally necessary to use number prefixes because the valence of the cation tells us the number of hydroxyl radicals in each molecule. You can see that this method of naming bases is very similar to the mehod used for naming salts, except that the anion is always hydroxide. For example, NaOH is called sodium hydroxide and Ca(OH)2 is called calcium hydroxide.
- KOH is potassium hydroxide
- Mg(OH)2 is magnesium hydroxide
- Fe(OH)2 is ferrous hydroxide
- Al(OH)3 is aluminum hydroxide
- Fe(OH)3 is ferric hydroxide