What is the formula for phosphite?

Answer 1

Traditionally the phosphite ion is HPO32-, and it is found in salts of the acid HP(OH)2 traditionally called phosphorous acid, which contains 2 ionizable and 1 non ionizable H (it is bonded to P). As it has two ionizable hydrogens it can form salts which contain HPO(OH)- ions, traditionally named hydrogenphosphite ion.

However IUPAC naming has now decreed that the phosphite ion is PO32-, which is fine except that the ion is not yet known to exist! Anything you see labeled "phosphite" will contain HPO22-., which IUPAC name hydrogenphosphite.

IUPAC have named the HPO(OH)- ion as dihydrogenphosphite. I am afraid that all of these names are in use, it is really confusing.
PO3 3-

Answer 2

Formula: PO33-

Answer 3

Formula: P3-

Answer 4

Formula: PH3

Answer 5

Formula: (NH4)3PO3

Answer 6

Formula: P3-