Final answer:
In a Brønsted-Lowry acid-base reaction, the original acid becomes a 'conjugate base' in the reverse reaction.
Step-by-step explanation:
A conjugate acid is the species produced when a base accepts a proton. In a Bronsted-Lowry acid-base reaction, the original acid becomes a conjugate acid in the reverse reaction. In a Brønsted-Lowry acid-base reaction, the original acid becomes a conjugate base in the reverse reaction. After an acid donates a proton, the species that remains is the conjugate base of that acid because it can accept a proton and act as a base in the reverse reaction. This is a key aspect of acid-base chemistry where acids and bases are defined by their ability to donate and accept protons, respectively. For example, when hydrogen sulfate ion (HSO₄⁻) donates a proton, it becomes a sulfate ion (SO₄²⁻), which is its conjugate base.