BrønstedLowrydefinisjonen

The Brønsted-Lowry theory, independently proposed by Johannes Nicolaus Brønsted and Thomas Martin Lowry in 1923, provides a fundamental definition of acids and bases. According to this theory, an acid is defined as a proton (H+) donor, while a base is defined as a proton acceptor. This concept is a significant expansion of the earlier Arrhenius definition, which focused on the production of hydrogen and hydroxide ions in aqueous solutions.

The Brønsted-Lowry theory emphasizes the transfer of a proton between chemical species. When an acid donates a proton to a base, a chemical reaction occurs. For instance, in the reaction of hydrochloric acid (HCl) with ammonia (NH3), HCl acts as the acid by donating a proton to NH3, which acts as the base. This results in the formation of a chloride ion (Cl-) and an ammonium ion (NH4+).

A key concept within the Brønsted-Lowry framework is that of conjugate acid-base pairs. When an acid loses a proton, it becomes its conjugate base. Conversely, when a base gains a proton, it becomes its conjugate acid. In the HCl and NH3 example, Cl- is the conjugate base of HCl, and NH4+ is the conjugate acid of NH3. This theory is applicable to reactions in both aqueous and non-aqueous solutions, making it a more versatile and widely used definition in chemistry.