What is the Conjugate Base of HPO4^2-?

The conjugate base of HPO₄^2- is PO₄^3-. To understand this, let’s break it down:

HPO₄^2- is a dihydrogen phosphate ion. When it donates a proton (H⁺), it forms the conjugate base. The reaction can be represented as:

HPO₄^2- → PO₄^3- + H⁺

In this reaction, HPO₄^2- loses a proton, resulting in the formation of PO₄^3-, which is the conjugate base. This is a common concept in acid-base chemistry, where the conjugate base is what remains after an acid donates a proton.