Answer :
Explanation:
According to the Bronsted-Lowry conjugate acid-base theory:
An acid is defined as a substance which looses donates protons and thus forming conjugate base.
A base is defined as a substance which accepts protons and thus forming conjugate acid.
For example:
[tex]HCl(aq)+NH_3(aq)\rightarrow Cl^-(aq)+NH_4^{+}(aq)[/tex]
Here, [tex]HCl [/tex] is loosing a proton, thus it is considered as an acid and after losing a proton, it forms [tex]Cl^-[/tex] which is a conjugate base.
And, [tex]NH_3[/tex] is gaining a proton, thus it is considered as a base and after gaining a proton, it forms [tex]NH_4^{+}[/tex] which is a conjugate acid.