A medium having a high @A00079@, generally greater than that of 100 wt.% sulfuric acid. The common superacids are made by dissolving a powerful @L03508@ (e.g. SbF5) in a suitable @B00744@ such as HF or HSO3F. (An equimolar mixture of HSO3F and SbF5 is known by the trade name 'magic acid'.) In a biochemical context 'superacid @C00874@' is sometimes used to denote @C00874@ by metal ions analogous to @C00874@ by hydrogen ions. By analogy, a compound having a very high @B00611@, such as lithium diisopropylamide, is called a 'superbase'.