An acid that has a proton-donating ability equal to or greater than that of anhydrous sulphuric acid. A superacid is a particular type of Brønsted acid. Those that are much stronger than sulphuric acids can be made by adding certain pentafluorides and their derivatives to such acids as fluorosulphuric acid (HSO₃F) or hydrogen fluoride (HF). The pentafluorides, such as antimony pentafluoride (SbF₅), are very strong Lewis acids. The mixtures HF-SbF₅ and HSO₃F-SbF₅ are among the strongest acids known; their applications include the protonation of very weak bases in organic chemistry and the abstraction of hydrogen from saturated hydrocarbons to produce carbonium ions. An equimolar mixture of HSO₃F and S₆F₅ is known by the Tradename Magic acid. Very strong bases, such as lithium diisopropylamide, are sometimes known as superbases.