ABSTRACT
The terms 'acid' and 'alkali' were first used in recognition of their properties in solution. Acids possessed a sour taste, and alkalis were able to neutralize or reverse the action of acids. The acid-base concept could be extended further, to that proposed by Lewis. He defined an acid as any substance that can accept electrons and a base as any substance able to donate electrons. An acid is therefore defined as a substance that has a tendency to donate hydrogen ions to an acceptor molecule. As the word 'tendency' suggests, some acids are much more effective at this than others—the auhtor can therefore talk of 'strong' and 'weak' acids. The Lowry—Bronsted definition of acids means that we should consider the strength of the bond H—A that breaks to yield a hydrogen ion and the conjugate base. Since Lowry—Bronsted bases donate electrons to a hydrogen ion, a Lowry—Bronsted base is also a Lewis base.
