What is the primary distinction between a strong acid and a weak acid?

The primary distinction between a strong acid and a weak acid lies in their behavior with respect to ionization in water. A strong acid fully ionizes in aqueous solution, meaning that when dissolved in water, it completely dissociates into its constituent ions. This complete dissociation results in a high concentration of hydrogen ions (H⁺) and a corresponding decrease in pH, leading to a highly acidic solution.

In contrast, a weak acid only partially dissociates when placed in water. This means that not all of the acid molecules will release hydrogen ions; instead, a significant portion remains intact in its molecular form, resulting in a lower concentration of hydrogen ions and a relatively higher pH compared to that of a strong acid.

This fundamental difference in dissociation is pivotal in understanding acid strength and its implications for chemical reactivity, solution pH, and overall acid behavior in various chemical processes.