7345. Phosphoric Acid, Meta

Nomenclature

CAS number: 37267-86-0
Metaphosphoric acid (HPO3); glacial phosphoric acid.
HO3P; mol wt 79.98.
H 1.26%, O 60.01%, P 38.73%.

Properties

Transparent, glass-like solid or soft silky masses; hygroscopic. Volatilizes at red heat. Very slowly sol in cold water, slowly changing to H3PO4, the change is hastened by boiling; sol in alcohol. Keep tightly closed. For greater convenience it is also marketed in form of rods made by the addition of sodium phosphate.

Use

In dentistry for making zinc oxyphosphate cement. Reagent in chemical analysis; acid digestion.