What are the limitations of Arrhenius theory of acid and bases?

Solution

(i) Limited scope: Arrhenius concept is limited to aqueous medium only. It fails to explain the behaviour of acids and bases in a non-aqueous solvent like ammonia,sulphur dioxide,alcohol, etc.
(ii) According to Arrhenius, the acidic and basic properties are due to H⁺ and OH^–ions respectively. However, these ions do not exist as such that readily get hydrated and represented as H⁺ (aq) and OH^– (aq).

(iii) It fails to explain the acidic nature of CO₂, SO₂, SO₃, N₂O₅ which do not contain any hydrogen.

(iv) It fails to explain the basic nature of CaO, NH₃,Na₂CO₃ which do not contain any hydroxyl group.