Answer
Bronsted-Lowry acid: $HI$
Bronsted-Lowry base: $H_{2}O$
Conjugate acid: $H_{3}O^+$
Conjugate base: $I^{-}$
Work Step by Step
According to the Bronsted-Lowry definition,
Acid: proton ($H^{+}$ ion) donor
Base: proton ($H^{+}$ ion) acceptor
In the reaction, $HI$ is the acid because, in solution, it donates a proton to water.
$H_{2}O$ is the base because it accepts the proton.
A conjugate acid is any base to which a proton has been added. So, $H_3O^+$ is the conjugate acid.
A conjugate base is an acid from which a proton has been removed. So, $I^-$ is the conjugate base.
