Explanation :
According to the Bronsted Lowry concept, Bronsted Lowry-acid is a substance that donates one or more hydrogen ion in a reaction and Bronsted Lowry-base is a substance that accepts one or more hydrogen ion in a reaction.
Or we can say that, conjugate acid is proton donor and conjugate base is proton acceptor
The given equilibrium reaction is,
In this reaction, and are act as Bronsted Lowry base and acid respectively and and are act as Bronsted Lowry acid and base respectively.
The formula of conjugate of is,
The formula of conjugate of is,