Answer: Option (2) is the correct answer.
Explanation:
Arrhenius acid are the species that donate a [tex]H^{+}[/tex] ion or proton.
For example, [tex]HBr \rightarrow H^{+} + Br^{-}[/tex]
Whereas LiF, [tex]Mg(OH)_{2}[/tex], and [tex]CH_{3}CHO[/tex] are the substances which do not give a proton upon dissociation. Hence, they are not Arrhenius acids.
Therefore, we can conclude that [tex]HBr(aq)[/tex] substance is an Arrhenius acid.
