List of the Strong Acids

These are the strong acids. What makes them "strong" is that they completely dissociate into their ions (H⁺ and an anion) when they are mixed with water. Any other acid is a weak acid. There are only seven strong acids, so you might want to commit the list of strong acids to memory. Note some instructors may ask for the six strong acids. That typically refers to the first six acids on this list.

• HCl - hydrochloric acid
• HNO₃ - nitric acid
• H₂SO₄ - sulfuric acid
• HBr - hydrobromic acid
• HI - hydroiodic acid (also known as hydriodic acid)
• HClO₄ - perchloric acid
• HClO₃ - chloric acid

As the strong acids become more concentrated, they may be unable to fully dissociate. The rule of thumb is that a strong acid is 100 percent dissociated in solutions of 1.0 M or less.