This is a list of the strong acids and strong bases. There aren’t very many, so it’s a good idea to memorize them, if you can.
Table of Strong Acids
The strong acids ionize completely in water to yield or or more protons per acid molecule.
| Name | Formula | Ionization |
| hydrogen iodide or hydroiodic acid | HI | H+(aq) + I–(aq) |
| hydrogen bromide or hydrobromic acid | HBr | H+(aq) + Br–(aq) |
| perchloric acid | HClO4 | H+(aq) + ClO4–(aq) |
| hydrochloric acid | HCl | H+(aq) + Cl–(aq) |
| chloric acid | HClO3 | H+(aq) + ClO3–(aq) |
| sulfuric acid | H2SO4 | H+(aq) + HSO4–(aq)* |
| nitric acid | HNO3 | H+(aq) + NO3–(aq) |
* HSO4– is a weak acid that contributes additional protons.
Table of Strong Bases
The strong bases ionize completely in water to yield or or more hydroxides per base molecule.
| Name | Formula | Ionization |
| sodium hydroxide | NaOH | Na+(aq) + OH–(aq) |
| potassium hydroxide | KOH | K+(aq) + OH–(aq) |
| lithium hydroxide | LiOH | Li+(aq) + OH–(aq) |
| rubidium hydroxide | RbOH | Rb+(aq) + OH–(aq) |
| cesium hydroxide | CsOH | Cs+(aq) + OH–(aq) |
| calcium hydroxide | Ca(OH)2 | Ca2+(aq) + 2OH–(aq) |
| barium hydroxide | Ba(OH)2 | Ba2+(aq) + 2OH–(aq) |
| strontium hydroxide | Sr(OH)2 | Sr2+(aq) + 2OH–(aq) |
Calcium hydroxide, barium hydroxide, and strontium hydroxide are not very soluble in water.