The @E02177@ \(K_{\text{H}n}\) for the addition of the \(n\)th @P04906@ to a charged or uncharged ligand. The cumulative protonation constant, \(\beta_{\text{H}n}\), is the @E02177@ for the formation of H_nL from \(n\) H⁺ and L. The same @E02177@ may be described in several ways, depending on how the ligand, L, or the acid, has been defined.