H3PO4+H2O⇄ H3O⁺ +H2PO4⁻
a₁ b ₂ a₂c b₁c K= [H3O⁺][H2PO4⁻]/ [H3PO4][H2O]
Ka=[H3O⁺][H2PO4⁻]/[H3PO4]=K[H2O]
H2PO4⁻+H2O⇄ H3O⁺+HPO4²⁻
a ₁ b ₂ a₂c b₁c K=[H3O⁺][HPO4²⁻]/[H2PO4⁻][H2O]
Ka=K[H2O]
HPO4²⁻+H2O ⇄ H3O⁺+PO4³⁻
a ₁ b₂ a₂c b₁c K= [H3O⁺][PO4³⁻]/[HPO4²⁻][H2O]
Ka=K[H2O]
