Welcome to Chem Zipper.com......: Oxy acids of Phosphorous:

Phosphorus forms two series of oxyacids namely; phosphorus acid and phosphoric acid.

SN	Element	Formula	Name of the Oxyacid	O.S.
2	Phosphorus	H₃PO₂ H₃PO₃ H₄P₂O₇	Hypo Phosphorus acid Ortho Phosphorus acid Pyro phosphorous acid	+1 +3 +3
3	Phosphoric	H₄P₂O₆ H₃PO₄ H₄P₂O₇ (HPO₄)_n	Hypo Phosphoric acid Ortho Phosphoric acid Pyro Phosphoric acid Meta phosphoric acid	+4 +5 +5 +5
4	Arsenic	H₃AsO₃ H₃AsO₄	Arsenious acid Arsenic acid	+3 +5
5	Sb & Bi	No stable acid

(A) Phosphorus acid series: (Structure)

The series consists of p atom exhibiting oxidation state of +3. They act as reducing agents.

(B) Phosphoric acid series: (Structure)

This series consist of acids having p in +5 oxidation state.

Note : Meta phosphoric does not exist in monomeric form, but it exists as cyclo meta phosphoric acid (HPO₃)₃ or polymeta phosphoric acid (HPO₃)_n. Sodiumhexametaphosphate is a famous salt known as CALGON and use water softener.

Special Note:

(1) Meta is used for acid obtained by loss of H₂O molecule.

(2) Pyro is used for the acid obtained from two molecules with a loss of H₂O.

(3) Hypo is used for the acid having lower oxygen content than the parent acid.

Related Questions:

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