What characterizes a strong acid in solution?

A strong acid is characterized by its ability to completely dissociate in water. This means that when a strong acid is dissolved in water, it breaks apart entirely into its constituent ions. For example, hydrochloric acid (HCl) dissociates into hydrogen ions (H⁺) and chloride ions (Cl⁻). This complete ionization in solution is what gives strong acids their high conductivity and ability to produce a significant concentration of hydrogen ions, thus making the solution highly acidic.

The complete dissociation results in a very low pH value, as the concentration of hydrogen ions determines the acidity of the solution. This fundamental distinction from weak acids, which only partially dissociate in water, underpins the behavior and characteristics of strong acids in chemical reactions and solutions.