A list of strong acids includes hydrochloric acid, nitric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, chloric acid and perchloric acid. When added to a solution, a strong acid ionizes completely and loses one proton. Ionization is the process by which a compound separates into its component ions.
The strength of an acid is related to its electronegativity, atomic radius, charge and equilibrium. A higher electronegativity, a larger radius and greater positive charge all correlate with a higher-strength acid. Strong acids are determined by their strength relative to the strength of a hydronium ion. A strong acid has a pKa of less than -1.74, where pKa relates to the acid dissociation constant. When the pKa is less than -1.74, the concentration of hydronium ions is the same as the concentration of the acid in an aqueous solution.
An acid that is not on the list of strong acids, which means it has a pKa that is equal to or greater than -1.74, does not fully dissociate into ions when introduced to a solution. The strength of an acid is related to its acidity, known as the pH, by way of the logarithm function. The dissociation of a strong acid can be shown through an equation.