Science, Tech, Math › Science List of the Strong Acids Share Flipboard Email Print Laguna Designs / Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated July 03, 2019 In chemistry, there are seven "strong" acids. What makes them "strong" is the fact that they completely dissociate into their ions (H+ and an anion) when they are mixed with water. Every other acid is a weak acid. Because there are only seven strong acids, it is easy to commit the list to memory. Note that some chemistry instructors may refer only to six strong acids. That typically means the first six acids on this list: HCl: Hydrochloric acidHNO3: Nitric acidH2SO4: Sulfuric acidHBr: Hydrobromic acidHI: Hydroiodic acid (also known as hydriodic acid)HClO4: Perchloric acidHClO3: 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.