Top 7 Strogest Acids In The World

Acids, substances that donate protons or hydrogen ions and/or accept electrons, play a crucial role in numerous chemical reactions and processes. From the citric acid in the food we eat to the sulfuric acid used in manufacturing fertilizers, acids are ubiquitous in our daily lives.

However, superacids, a category of significantly stronger acids than conventional strong acids, have unique properties that make them invaluable in certain chemical reactions. These superacids are so strong that they can protonate molecules that ordinary acids cannot, opening up new possibilities in the field of chemistry.

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Here we would like to share with you the top 7 strongest acids in the world with various industrial applications.

7. Triflic Acid (CF3SO3H)

Triflic Acid, or its chemical name Trifluoromethanesulfonic Acid, is a superacid that was first discovered back in 1954 by a British chemist, Robert Haszeldine. Triflic Acid is a colorless, slightly viscous liquid which is soluble in polar solvents.

Triflic Acid exhibits strong acidic properties, having a pKa value of -14.7 ± 2.0. Triflic Acid is mainly used in research as a catalyst for various organic synthesis reactions such as alkylation, esterification and etc.

6. Hydrobromic Acid (HBr)

Hydrobromic Acid, also known as HBr, is a powerful acid formed by dissolving hydrogen bromide in water1. It is a diatomic molecule and is one of the strongest mineral acids known to man.

Hydrobromic acid is a colorless or faint yellow liquid with a pungent, irritating odor. Hydrobromic acid exhibits strong acidic properties, having a pKa value of -9, making it stronger than hydrochloric acid.

Hydrobromic acid exhibits strong acidic properties, having a pKa value of -95, making it stronger than hydrochloric acid. It is a useful reagent for generating organobromine compounds.

5. Fluorosulfuric Acid (HSO3F)

Fluorosulfuric acid (HSO₃F) or known by its other name, sulfurofluoridic acid is an inorganic compound. It is closely related to sulfuric acid (H₂SO₄), with a fluorine atom substituting one of the hydroxyl groups.

It can be found in yellow color in its pure form and is alarmingly corrosive and toxic. Its Hammett acidity function value is around -15.1, compared to -12 for sulfuric acid. HSO₃F is often created by combining sulfur trioxide with hydrogen fluoride.

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When combined with antimony pentafluoride, this reaction yields "Magic acid," a far more potent acid and protonating agent.

4. Perchloric acid (HClO4)

Perchloric acid (HClO₄) is a mineral acid and it is considered the strongest Brønsted–Lowry acid. Usually found as an aqueous solution, this colorless compound is a stronger acid than sulfuric acid, nitric acid, and hydrochloric acid.

Perchloric acid is estimated to be at least one million times stronger than pure sulfuric acid in terms of its Hammett acidity function values. Perchloric acid is usually formed by reacting sodium perchlorate with hydrochloric acid (HCl).

This reaction leads to the production of both perchloric acid and sodium chloride. Perchloric acid is commonly used, and in some cases even desired, in syntheses despite its explosive characteristic. It is also a crucial part of ammonium perchlorate, which is an essential element in modern rocket fuel.

3. Fluorinated Carborane Acid (H(CHB11F11))

Structure of Carborane Acid

Among the strongest classes of superacids known to mankind are carborane acids. Fluorinated Carborane Acid is among the strongest of them all and is a very moisture-sensitive solid, prepared by treatment of anhydrous HCl with [Et3Si-H-SiEt3][CHB11F11].

Fluorinated Carborane Acid is estimated to be at least one million times stronger than 100% pure sulfuric acid in terms of its Hammett acidity function values (H₀ ≤ –18). It’s the only known acid capable of protonating carbon dioxide, yielding the bridged cation [H(CO₂)₂]⁺.

2. Magic Acid (FSO3H·SbF5)

Magic acid is a concoction of two acidic heavyweights: fluorosulfuric acid (HSO₃F) and antimony pentafluoride (SbF₅). When measuring by its Hammett acidity function, magic acid is trillions of times stronger than pure sulfuric acid.

It’s a mix of HF-solvated protons (HF molecules cuddling up to protons) and SbF₅-adducts of fluoride (like Sb₄F₂₁⁻). The acid contains “naked protons,” always bonded to HF molecules.

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One of its industrial uses will be that not only does it speed up the isomerization of saturated hydrocarbons but also can protonate weak bases such as methane, xenon, and halogens.

1. Fluoroantimonic acid (H2FSbF6)

Fluoroantimonic acid is a remarkable and exceptionally potent superacid. It’s like the heavyweight champion of acids, flexing its corrosive muscles in the chemical ring. Fluoroantimonic acid is a mixture of hydrogen fluoride (HF) and antimony pentafluoride (SbF₅). These two components join forces to create a fearsome duo.

Similar to magic acid, Fluoroantimonic acid is also trillions of times stronger than pure sulfuric acid when measured by its Hammett acidity function. Fluoroantimonic acid struts its stuff in chemical engineering and organic chemistry. It protonates organic compounds, making them do the acid dance. The good news is that it cannot erode containers lined with Teflon.

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