For a Polyprotic Acid Which Statement Is True?

A polyprotic acid has a single associated pK_a value. A polyprotic acid can only react with one equivalent of base. The conjugate base of a polyprotic acid can also act as an acid itself. All of these statements are true.

What is true for Polyprotic acids?

Polyprotic acids contain more than one mole ionizable hydronium ions per mole of acids. They ionize to give more than one H+ ions per molecule.

How do you identify a Polyprotic acid?

As their name suggests, polyprotic acids contain more than one acidic proton. Two common examples are carbonic acid (H₂CO₃, which has two acidic protons and is therefore a diprotic acid) and phosphoric acid (H₃PO₄, which has three acidic protons and is therefore a triprotic acid).