Phosphorous acid is the compound described by the formula H3PO3. This acid is diprotic (readily ionizes two protons), not triprotic as might be suggested by this formula. Phosphorous acid is an intermediate in the preparation of other phosphorus compounds.

H3PO3 is more clearly described with the structural formula HPO(OH)2. In the solid state, HP(O)(OH)2 is tetrahedral with one shorter P=O bond of 148 pm and two longer P–O(H) bonds of 154 pm. This species exists in equilibrium with an extremely minor tautomer P(OH)3. IUPAC recommends that the latter be called phosphorous acid, whereas the dihydroxy form is called phosphonic acid. Only the reduced phosphorus compounds are spelled with an "ous" ending.

Other important oxyacids of phosphorus are phosphoric acid (H3PO4) and hypophosphorous acid (H3PO2). The reduced phosphorus acids are subject to similar tautomerism involving shifts of H between O and P.

Specification of Phosphorous Acid/PA

Payment Term

In Jinama, we have three terms used popularly that are

1. 100% T/T in advance

2. 30% T/T in advance, 70% T/T before shipment(or against Bill of Lading)

3. Irrevocable L/C at sight

Other terms are also available in Jinama, please kindly advise our sales.

Delivery Time

1. stock products: about 10 days

2. Production order: about 40 days to 60 days according to the order list.

3. Other requirements are negotiable.