H– reaction pathways

Abstract

The reactivity of H^– with Brønsted acids in strictly anhydrous solvents is discussed. H^– reacts swiftly and completely with weak acids such as H₂O, CH₃OH, CH₃CO₂H, CH₂(CO₂H)₂ or CH₃CO₂NH₄, but reacts slowly and incompletely with strong acids such as HI, HBr, H₂SO₄ or H₃PO₄. This seemingly paradoxical behaviour is understood by observing that the acid–base reaction is kinetically limited by a high activation energy, while the electron-transfer reaction to polar molecules such as those of the H₂O family requires a much lower activation energy.