What is a Bronsted Base

Brønsted acid-base concept

Brønsted acid-base concept, Definition of acids and bases based on the consideration of proton transfer reactions. According to J.N. Brønsted and T.M. Lowry (1923) consider compounds that H. + -Ions (protons) can release as acids (HA) and substances that H + -Ions can take up, referred to as bases (B). In the acid-base reaction, a protolysis equilibrium is established: HA + B

A + bra + . For water as a solvent one can write: HA + H2O

A- + H3O + or B + H2O

HB + + OH- (water is an ampholyte).

According to the Brønsted definition, a distinction is made between neutral acids (e.g. HCl) and anionic acids (e.g. HSO4-) and cation acids (e.g. H3O + , NH4 + ). Acid anhydrides are substances that only turn into a Brønsted acid by reacting with water (e.g. SO3). Similarly, one can differentiate between neutral, anion and cation bases (examples: NH3, OH- or [Al (OH2)5OH]2 + ). “Base anhydrides”, on the other hand, do not exist in this concept. Acids that n Protons can give off are called n-basic acids called. Analog can n-acid bases n Pick up protons. Unlike the Arrhenius acid-base concept, this theory is not limited to either water as a solvent or the liquid phase at all. In contrast to the Lewis acid-base concept, however, it always requires a proton-containing reaction partner.