What Is the World's Strongest Acid and How Is It Gentle?

TL;DR

The world's strongest acid is chlorinated carborane acid, which, despite its potency, is gentle enough to potentially modify molecules without damage. Unlike other superacids that are highly reactive, carborane acids have stable conjugate bases, making them suitable for applications like enhancing vitamin supplements.

Transcript

What’s the first image that comes to mind when I say “the world’s strongest acid”? Is it that scene from a certain chemistry-informed show where hydrofluoric acid is used to dissolve a corpse… …and then the bathtub the corpse was inside of… …and then the bathroom floor? Sounds pretty strong! But in the grand scheme of things, hydrofluoric acid is n... Read More

Key Insights

• 💪 Hydrofluoric acid and fluoroantimonic acid are strong acids but not the strongest.
• 😥 The pH scale is not suitable for measuring the strength of superacids.
• 😑 The Hammett acidity function considers both the hydrogen ion and the conjugate base of an acid to determine its strength.
• 🫢 Carborane acids are the strongest known acids across solid, liquid, and gas phases.
• 💪 Carborane acids have non-reactive conjugate bases, which makes them gentle but strong.
• 📶 The strength of superacids can be measured by their proton affinity and reaction with other superacids.
• 🈸 Carborane acids have potential applications in modifying acidified molecules, such as those used in vitamin supplements.

Questions & Answers

Q: What is the criteria for determining the strength of an acid?

The strength of an acid is determined by its acid dissociation constant (Ka), which compares the number of acid molecules that have donated their protons to those that are still intact.

Q: Why is the pH scale not suitable for measuring the strength of superacids?

The pH scale only considers the concentration of hydronium ions, created when protons bond with water molecules, and is limited in accuracy. It also cannot measure pH for acids stronger than sulfuric acid.

Q: How is the strength of superacids measured?

Chemists use the Hammett acidity function, which considers both the hydrogen ion (proton) and the conjugate base of an acid. The weaker the conjugate base, the stronger the acid.

Q: What makes carborane acids the strongest acids known?

Carborane acids have been identified as the strongest singular acids across solid, liquid, and gas phases. They have a unique structure and leave behind non-reactive conjugate bases, making them gentle but strong.

Summary & Key Takeaways

• Hydrofluoric acid, fluoroantimonic acid, and sulfuric acid are all strong acids but not the strongest.

• The strength of an acid is determined by its acid dissociation constant (Ka).

• The pH scale is not suitable for measuring the strength of superacids, which are stronger than sulfuric acid.

• The Hammett acidity function is used to measure the strength of superacids, taking into account the acid's conjugate base.

• Carborane acids have been identified as the strongest singular acids across solid, liquid, and gas phases.