The total number of different kinds of buffers that can be theoretically obtained during the complet — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

$H_3PO_4$ is a triprotic acid and undergoes titration in three distinct equivalence steps. The intermediate buffer regions correspond to the conjugate pairs of successive ionizations: Region 1 is $H_3PO_4 / H_2PO_4^-$. Region 2 is $H_2PO_4^- / HPO_4^{2-}$. Region 3 is $HPO_4^{2-} / PO_4^{3-}$. A pair like $H_3PO_4 / HPO_4^{2-}$ differs by two protons and does not form a standard simple buffer.