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.