How To Identify Bronsted- Lowry Acid Base Pairs In A Reaction

Bronsted Lowry acid is a proton (H+) donor, while the base is proton (H+) acceptor.

In other words, Bronsted Lowry acid loses a hydrogen while Bronsted Lowry base gains a hydrogen.

In order to correctly identify each one we must look first look on the left side of the equation(reactants side) and determine if a molecule lost or gained a hydrogen as it went from the reactant to the product side. If it lost a hydrogen, it was a Bronsted Lowry acids. If the molecule gained a hydrogen, it must have been a Bronsted Lowry base. On the product side, there will be the conjugates of the reactant molecules. Thus, if A on the reactant side was a Bronsted Lowry base, HA on the product side will be its conjugate acid.