Does dilute acid contain any hydroxyl ions. Explain with diagram.

This definition is based on a generalization of the earlier Arrhenius definition to all autodissociating solvents. In all such solvents there is a certain concentration of a positive species, solvonium cations and negative species, solvate anions, in equilibrium with the neutral solvent molecules. For example:

2H₂O ⇌ H₃O⁺ (hydronium) + OH^- (hydroxide)

2NH₃ ⇌ NH₄⁺ (ammonium) + NH₂⁻ (amide)

or even some aprotic systems.