Question

Write the ka expression for h2po4− in water. click in the answer box to activate the palette.

Answer 1

Balanced chemical reaction: H₂PO₄⁻(aq) + H₂O(l) ⇄ HPO₄²⁻(aq) + H₃O⁺(aq).
or H₂PO₄⁻(aq) ⇄ HPO₄²⁻(aq) + H⁺(aq).
Ka is the acid dissociation constant, which quantifies the extent of acid dissociation (in this example H₂PO₄⁻) in water.
Ka = [HPO₄²⁻]·[H₃O⁺] / [H₂PO₄⁻].
or Ka = [HPO₄²⁻]·[H⁺] / [H₂PO₄⁻].