University:
Loyola University Maryland
Course:
CH 101 | General Chemistry I
Academic year:

2024
Views:

419

Pages:

2
Author:

Natasya J.

Acids & Bases Bronsted Acids and Bases Arrhenius (classical) acids are proton donors. Arrhenius bases are hydroxide ion donors. Bronsted acids are defined as proton donors but in more general definition. Bronsted bases are proton acceptors. This leads to concept of acid-base conjugate pairs. The removal of a proton from any species (a bronsted acid) produces its conjugate base (a proton acceptor). The addition of a proton for any acceptor species (a bronsted base) produces its conjugate acid (a proton donor) All acid-base reaction now become the reaction of an acid-base pair to produce another acid-base pair (the conjugate base and the conjugate acid of the first pair). The dissociation of an acid in water produces a hydronium ion (the conjugate acid of water), not a bare proton. HA(aq) + H₂O(l) ↔ H₃O⁺(aq) + A⁻(aq) Hydrogen ion does not have a free existence in water and can only exist as the hydronium ion, H₃O⁺(aq). It is often still represented as just H⁺. Many substances which do not contain hydroxide ion can now be classed as bases, such as fluoride ion, cyanide ion, phosphate ion, bicarbonate ion, ammonia, etc. All are proton acceptors to some degree and all produce some hydroxide ion in aqueous solution. Ammonia is the classic example of a base that does not have hydroxide in it's molecular formula. NH₃(aq) + H₂O(l) ↔ NH₄⁺(aq) + OH⁻(aq) Exs: Identify conjugate acids of bases and conjugate bases from acid formulas.