protonation constant
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 HnL 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.
Orange Book, 2nd ed., p. 13 [Terms] [Book]