Why does an aqueous solution of an acid conduct electricity?

The presence of hydrogen ions (H+) or hydronium ions (H3O+) in aqueous solution of an acid are responsible for conducting electricity. For example; hydrochloric acid (HCl) dissociates in aqueous solution and gives hydrogen ions [H+ (aq)] and chloride ions [Cl-(aq)] which carry electric current. So, due to the presence of these ions, an aqueous solution of hydrochloric acid conducts electricity.