Dictionary
phosphor'ic ac'id
Chem.
any of three acids, orthophosphoric acid, H
3PO
4, metaphosphoric acid, HPO
3, or pyrophosphoric acid, H
4P
2O
7, derived from phosphorus pentoxide, P
2O
5, and various amounts of water.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.