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-
The formula for silver phosphite is Ag3PO3.
The formula for manganese(III) phosphite is MnPO3.
The chemical formula for cobalt phosphite is Co3(PO3)2.
Well, we know that the polyatomic ion phosphate has the formula PO4^3- The suffix "ite" tells us that we take one oxygen atom. So phosphite is PO3^3- Since the charge of phosphite is negative three, we need 3 gold ions to create a neutral ionic compound. So, the chemical formula for gold phosphite is Au3PO3
The compound formed between magnesium and phosphite ion is magnesium phosphite (Mg3(PO3)2).
The formula for silver phosphite is Ag3PO3.
The formula for cesium phosphite is Cs3PO3.
The formula for manganese(III) phosphite is MnPO3.
The compound formula of sodium phosphite is Na3PO3.
The chemical formula for sodium dihydrogen phosphite is NaH2PO3.
The chemical formula of trimethyl phosphite is (CH3O)3P.
The chemical formula for magnesium hydrogen phosphite is Mg(H2PO3)2.
The chemical formula for cobalt phosphite is Co3(PO3)2.
HPO3
The dihydrogen phosphite ion formula is H2PO3-. It consists of two hydrogen atoms and one phosphite atom with an overall charge of -1.
Formula: NaH2PO3
Well, we know that the polyatomic ion phosphate has the formula PO4^3- The suffix "ite" tells us that we take one oxygen atom. So phosphite is PO3^3- Since the charge of phosphite is negative three, we need 3 gold ions to create a neutral ionic compound. So, the chemical formula for gold phosphite is Au3PO3