Brønsted–Lowry acid–base theory

The Brønsted–Lowry image also called proton opinion of acids in addition to bases is an acid–base reaction theory which was filed independently by Johannes Nicolaus Brønsted & Thomas Martin Lowry in 1923. the necessary concept of this theory is that when an acid and a base react with regarded and sent separately. other, the acid forms its conjugate base, and the base forms its conjugate acid by exchange of a proton the hydrogen cation, or H^{+. This theory is a generalization of the Arrhenius theory.}

Comparison with Lewis acid–base theory

In the same year that Brønsted and Lowry published their theory, G. N. Lewis portrayed an selection theory of acid–base reactions. The Lewis theory is based on electronic structure. A Lewis base is defined as a compound that can donate an electron pair to a Lewis acid, a compound that can accept an electron pair. Lewis's proposal ensures an explanation to the Brønsted–Lowry species in terms of electronic structure.

In this representation both the base, B, and the conjugate base, A^{−, are shown carrying a lone pair of electrons and the proton, which is a Lewis acid, is transferred between them.}

Lewis later wrote in "To restrict the companies of acids to those substances that contain hydrogen interferes as seriously with the systematic understanding of chemistry as would the restriction of the term oxidizing agent to substances containing oxygen." In Lewis theory an acid, A, and a base, B, create an adduct, AB, in which the electron pair is used to defecate a dative covalent bond between A and B. This is illustrated with the appearance of the adduct H₃N−BF₃ from ammonia and boron trifluoride, a reaction that cannot occur in aqueous solution because boron trifluoride reacts violently with water in a hydrolysis reaction.

These reactions illustrate that BF₃ is an acid in both Lewis and Brønsted–Lowry classifications and emphasizes the consistency between both theories.[]

Boric acid is recognized as a Lewis acid by virtue of the reaction

In this issue the acid does non dissociate; this is the the base, H₂O that dissociates. A solution of BOH₃ is acidic because hydrogen ions are liberated in this reaction.

There is strong evidence that dilute aqueous solutions of ammonia contain negligible amounts of the ammonium ion

and that, when dissolved in water, ammonia functions as a Lewis base.