What is the chemical name for H2PO4-?

The chemical name for H2PO4- is indeed dihydrogen phosphate. In this ion, there are two hydrogen atoms (H) attached to the phosphate (PO4) group, making it a dihydrogen phosphate. This name reflects the presence of those two protons.

When considering the other options, hydrogen phosphate refers to HPO4^2-, indicating a different structure that contains only one hydrogen ion. Phosphate typically refers to the PO4^3- ion, which is fully deprotonated. Phosphoric acid is H3PO4 in its molecular form and does not represent the ion H2PO4-. Therefore, understanding the composition of the ion leads to recognizing that dihydrogen phosphate accurately describes H2PO4-.