[SimoneMeyer]

HI_(aq) + H2O _(l) --> I^-_(aq) + H₃O⁺_(aq)

How does this equation explain the Bronsted-Lowry theory of acide/base?

I understand the theory:

An acid is any substance that a proton/protons during a reaction and a base is all substances that accept a proton/protons.

Is this equation for an acid or base, or both?

I just don't understand how this equation "explains" the theory.

[MrTeo]

Well, this equation represents the dissociation of HI in water, so the proton given by the acid bonds to the H₂O molecule to form the H₃O⁺ ion. In this case water (which is an amphoteric substance, in fact it can both accept, like here, and give protons, becoming OH^-) behaves as a base (Brönsted-Lowry base) accepting a proton, while HI behaves as an acid giving one and becoming I^-.
Moreover you can link both acids and bases with their conjugates (bases and acids), in this case I^- is the conjugate base of HI (can accept a proton), while H₃O⁺ is the conjugate acid of water (can give H⁺).



Hope it's all clear now... we say that it "explains" this theory as it's an equation which contains an exampe for all the possible situations described by this model.

[SimoneMeyer]

Thank you so very much!