Hydroiodic acid (HI) is classified as a strong electrolyte. This classification is based on its ability to completely dissociate into its ions when dissolved in water.
When hydroiodic acid is added to water, it ionizes completely to form hydrogen ions (H+) and iodide ions (I–). This complete dissociation is characteristic of strong electrolytes, which are known for their high conductivity in aqueous solutions due to the presence of a large number of free ions. In contrast, weak electrolytes only partially dissociate, while non-electrolytes do not dissociate into ions at all.