Dissociation of bases

Bases have the same net result as alkalis: They reduce the concentration of H⁺ ions in solution although they do not dissociate into OH^- ions.

The stronger the base, the more free H⁺ ions it can accept from a solution.

A common base is ammonia (NH₃). As it binds to free H⁺ ions in solution it becomes ammonium (NH₄⁺).

The formation of NH₄⁺ from NH₃ is reversible. This means that under different circumstances the H⁺ might be released from the NH₄⁺.

NH₃ is therefore a base because it accepts H⁺ ions; but NH₄⁺ is an acid because it donates H⁺ ions.

Any molecules (not just bases) that can accept and donate H⁺ ions are called buffers.