Following are the limitations of Arrhenius theory of acid and base:
- This theory is limited to aqueous medium only.
- According to Arrhenius theory, acids are those which furnish H+ ion in water. H+ ion is a proton which is not capable of independent existence. It may exist as hydronium ion H3O+.
- There are number of substances like CO2 , SO₂ , NO2 , SO3 which do not contain H+ ion but behaves as acids. Similarly compounds like CaO, MgO, anhydrous NH3 , Na2CO3 which do not contain OH– ion but behave as bases.
- Neutralization between HCl and do not involve H+ and OH– ions-
NH3 + HCl → NH4Cl (s)
CaO + SO₂ → CaSO3 (s)