Draw the structure of H₂P₄O₇. Explain why?

H₂P₄O₇ is not known it can be H₂P₄O₇ ^-2. It is actually anion of H₄P₂O₇ known as pyrophosphoric acid after the removal of 2 protons. Pyrophosphoric acid is dimer of phosphoric acid (H₃PO₄) so the structure of pyrophosphoric acid is similar to phosphoric acid .Structure of pyrophosphoric acid is shown below.Both the P is in tetrahedral geometry as in phosphoric acid.