Strong Acids

A strong acid is one which reacts completely with water to produce hydronium ions. In other words, a strong acid is fully deprotonated in water.
HX(aq) + H₂O(l) ---> H₃O⁺(aq) + X^-(aq)

If each molecule of strong acid in the animation represents one mole of HX, then in aqueous solution, we have six moles of hydronium ions and six moles of X^- ions, and no moles of HX molecules.

The common strong acids are HCl, HBr, HI, HNO₃, HClO₄, HClO₃, and H₂SO₄ (to HSO₄^-).