Laboratory Preparation of Pyrophosphoric Acid - QS Study
QS Study

Preparation: Pyrophosphoric acid (H4 P2 O7) is prepared by heating orthophosphoric acid to 523 K – 533 K.

2H3PO4 → H4P2O7 + H2O


Physical Properties

It is a colourless crystalline solid.

Chemical Properties

  • It is reconverted to orthophosphoric acid on boiling with water

H4P2O7 + H2O →2H3PO4

  • When heated strongly, it yields metaphosphoric acid

H4P2O7 → 2ΗPO3 + H2O

Structure: The Structure of pyrophosphoric acid is represented as: