Ammonia (NH₃) shows basic character in aqueous solution:
NH₃ + H₂O ⇄ NH₄⁺ + OH⁻. This is basic buffer, because contains hydroxide anions.
Ammonium chloride is salt and in water dissociate:
NH₄Cl → NH₄⁺ + Cl⁻.
Ammonium ion shows acidic character in aqueous solution::
NH₄⁺ + H₂O ⇄ NH₃ + H₃O⁺.
Ka = [NH₃] · [H₃O⁺] ÷ [NH₄⁺].
