section_path: Reaction types/Acid–base reactions
section_name: Acid–base reactions
paragraph_text: Acid–base reactions
  
  In the Brønsted–Lowry acid–base theory, an acid–base reaction involves a transfer of protons (H) from one species (the acid) to another (the base). When a proton is removed from an acid, the resulting species is termed that acid's conjugate base. When the proton is accepted by a base, the resulting species is termed that base's conjugate acid. In other words, acids act as proton donors and bases act as proton acceptors according to the following equation: HA acid + B base ↽ − − ⇀ A − conjugated base + HB + conjugated acid {\displaystyle {\ce {{\underset {acid}{HA}}+{\underset {base}{B}}<=>{\underset {conjugated\ base}{A^{-}}}+{\underset {conjugated\ acid}{HB+}}}}}
  
  The reverse reaction is possible, and thus the acid/base and conjugated base/acid are always in equilibrium. The equilibrium is determined by the acid and base dissociation constants (K and K) of the involved substances. A special case of the acid-base reaction is the neutralization where an acid and a base, taken at the exact same amounts, form a neutral salt.
  
  Acid-base reactions can have different definitions depending on the acid-base concept employed. Some of the most common are: