Question

B(OH)3(aq) + H2O(l) ⇆ B(OH)4-(aq) + H+(aq) Select the correct description of this reaction using Lewis acid-base theory. * In the forward reaction, B(OH)3 is the ? and H2O is the ? . * In the reverse reaction, B(OH)4- is the ? and H+ is the ? . answer choices for each lewis acid or lewis base

Answer 1

The Lewis theory for acids and base states that all species with lone pairs of electrons or such donatable non-bonding electrons are bases and all species which accept electrons from Lewis bases are Lewis acids.

The given reaction is considered as the reaction involving the formation of an adduct of boric acid with hydroxide ion, in short acid-base adduct formation reaction. In the reaction, boron of boric acid is electron deficient and accepts the lone pair of eletctrons from O of water to form the adduct B(OH)₄^- making boric acid the Lewis acid and water the Lewis base in the forward reaction.

In the reverse reaction, the proton is viewed as the electron acceptor which accepts non-bonding electrons from B(OH)₄^- and forms the adduct - water. This makes proton the Lewis acid and B(OH)₄^- the Lewis base in the reverse reaction.