Topic summary
Polyphosphoric acid
Extracted from the Wikipedia article Phosphoric acids and phosphates.
Oligophosphoric and polyphosphoric acids
Two or more orthophosphoric acid molecules can be joined by condensation into larger molecules by elimination of water. Condensation of a few units yields the oligophosphoric acids, while larger molecules are called polyphosphoric acids. (However, the distinction between the two terms is not well defined.)