Fluoroantimonic acid

Fluoroantimonic acid is a mixture of hydrogen fluoride and Antimony pentafluoride. This chemical is a superacid that can be more than 10¹⁵ times stronger than pure sulfuric acid, with pH generally dependent on the ratios of hydrogen fluoride and antimony pentafluoride. It is reported to have a pH of -31.3. Extreme care must be taken when handling and storing fluoro­antimonic acid; it is more than corrosive enough to dissolve ordinarily corrosion-resistant materials, including glass. It is generally stored in PTFE-coated (commonly known as Teflon) containers, as only the fluoride-carbon bonds in PTFE are strong enough to resist protonation from fluoroantimonic acid.