The species formed when a Brønsted-Lowry base gains a proton is the conjugate acid of the base. The compound that accepts the proton is called a Brønsted-Lowry base.

Thus, an acid-base reaction occurs when a proton is transferred from an acid to a base, with formation of the conjugate base of the reactant acid and formation of the conjugate acid of the reactant base. Amphiprotic species can act as both proton donors and proton acceptors.

autoionization — reaction between identical species yielding ionic products; for water, this reaction involves transfer of protons to yield hydronium and hydroxide ions. amphiprotic — species that may either donate or accept a proton in a Brønsted-Lowry acid-base reaction. pH — logarithmic measure of the concentration of hydronium ions in a solution. conjugate base — substance formed when an acid loses a proton.