Bronsted-Lowry Acid Definition

Bronsted-Lowry Acid Definition In 1923, chemists Johannes Nicolaus Brà ¸nsted and Thomas Martin Lowry independently described acids and bases based on whether they donate or accept hydrogen ions (H). The groups of acids and bases defined in this manner came to be known as either Bronsted, Lowry-Bronsted, or  Bronsted-Lowry acids and bases. A Bronsted-Lowry acid is defined as a substance that gives up or donates hydrogen ions during a chemical reaction. In contrast, a Bronsted-Lowry base accepts hydrogen ions. Another way of looking at it is that a Bronsted-Lowry acid donates protons, while the base accepts protons. Species that can either donate or accept protons, depending on the situation, are considered to be amphoteric. The Bronsted-Lowry theory differs from the Arrhenius theory in allowing acids and bases that dont necessarily contain hydrogen cations and hydroxide anions. Key Takeaways: Bronsted-Lowry Acid The Bronsted-Lowry theory of acids and bases was proposed independently in 1923 by Johannes Nicolaus Brà ¸nsted and Thomas Martin Lowry.A Bronsted-Lowry acid is a chemical species that donates one or more hydrogen ions in a reaction. In contrast, a Bronsted-Lowry base accepts hydrogen ions. When it donates its proton, the acid becomes its conjugate base.A more general look at the theory is as an acid as a proton donor and a base as a proton acceptor. Conjugate Acids and Bases in Bronsted-Lowry Theory Every Bronsted-Lowry acid donates its proton to a species which is its conjugate base. Every Bronsted-Lowry base similarly accepts a proton from its conjugate acid. For example, in the reaction: HCl (aq) NH3 (aq)→ NH4 (aq) Cl- (aq) Hydrochloric acid (HCl)  donates a proton to ammonia (NH3) to form the ammonium cation (NH4) and the chloride anion (Cl-). Hydrochloric acid is a Bronsted-Lowry acid; the chloride ion is its conjugate base. Ammonia is a Bronsted-Lowry base; its conjugate acid is the ammonium ion. Sources Brà ¶nsted, J. N. (1923). Einige Bemerkungen à ¼ber den Begriff der Suren und Basen [Some observations about the concept of acids and bases]. Recueil des Travaux Chimiques des Pays-Bas. 42 (8): 718–728. doi:10.1002/recl.19230420815Lowry, T. M. (1923). The uniqueness of hydrogen. Journal of the Society of Chemical Industry. 42 (3): 43–47. doi:10.1002/jctb.5000420302