Beryllium phosphite can have the formulas of either
Be(OH)HPO3 or Be(OH)(H2PO3)2. It is the former that
appears when phosphorous acid is reacted with the
oxide, hydroxide or carbonate:
BeO (s) +H3PO3 (aq) ? [Be(OH)]2HPO3
The product is the hydrogen phosphite. If the sodium
salt is employed, then the product is likely to be the
phosphite:
BeO (s) + Na3PO3 ? [Be(OH)]3PO3
On heating, it decomposes around 400°C to form the
pyrophosphite:
3[Be(OH)]3PO3 + heat ? Be3(PO3)2 = {Be3P2O6}
+ 3H2 + PH3
