Comparative table of acid-base theories

Arrhenius

A species that increases the concentration of hydrogen ions, H⁺, in an aqueous solution.
H⁺ ions react immediately with
H₂O to form oxidanium ions (H₃O⁺).

HCl_(ac)→H⁺_(ac)+ Cl^–_(ac)

Species that increases the concentration of hydroxide ions, OH^–, in an aqueous solution.

NaOH_(ac)→ Na⁺_(ac)→OH^–_(ac)

Brønsted-Lowry

Kind that donates a proton, H⁺.
* Water is defined as an amphoteric substance as it can act as an acid or a base. *
* Conjugated acid is the species that is formed when a Brønsted-Lowry base accepts a proton. *

NH₃(g)+HCl (g) → NH₄Cl (s)
* Also expressed as

* Conjugated acid

A species that accepts a proton, which requires a lone pair of electrons to bond to H⁺.
* Conjugate base is the species that forms after a Brønsted-Lowry acid gives up a proton. *

NH₃(ac)+H₂OR(l⇌NH₄⁺(ac) + OH^–(ac)
* Conjugate base
OH^–(ac)

Kind that accepts and shares
a pair of electrons given up by a base.

Acid + Base → adduct
H⁺+ : NH₃

A species that gives up a pair of electrons and shares them with an acid.

Acid + Base → adduct

HCl + NaOH → NaCl + H₂O

Acid + Base → Salt + Water

HCl + NaOH → NaCl + H₂O

Acid + Base → Conj base + Conj acid.

HCl + NaOH → NaCl + H₂O

Acid + Base → adduct

HCl + NaOH → NaCl + H₂O

H₂PO₄^– + HCl → H₃PO₄ + Cl^–

Does not apply

Acid + Base → Conj acid. + Conj base

H₂PO₄^– + HCl → H₃PO₄ + Cl^–

Acid + Base → adduct

H₂PO₄^– + HCl → H₃PO₄ + Cl^–

* Arrhenius theory does not apply because an OH ion is necessary for definition.

AlCl₃ + NH₃ → [Al (NH₃) Cl₃]

Does not apply

Does not apply

Acid + Base → adduct

AlCl₃ + NH₃ → [Al (NH₃) Cl₃]

* Everyone
Brønsted-Lowry acids and bases
they are Lewis acids and bases, but not all Lewis acids and bases are Brønsted-Lowry.