| |||
Names | |||
---|---|---|---|
IUPAC name
Phosphinic acid
| |||
Other names
Hydroxy(oxo)-λ5-phosphane
Hydroxy-λ5-phosphanone | |||
Identifiers | |||
3D model (JSmol)
|
|||
ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard | 100.026.001 | ||
KEGG | |||
PubChem CID
|
| ||
UNII | |||
UN number | UN 3264 | ||
CompTox Dashboard (EPA)
|
|||
| |||
| |||
Properties | |||
H3PO2 | |||
Molar mass | 66.00 g/mol | ||
Appearance | colorless, deliquescent crystals or oily liquid | ||
Density | 1.493 g/cm3[2]
1.22 g/cm3 (50 wt% aq. solution) | ||
Melting point | 26.5 °C (79.7 °F; 299.6 K) | ||
Boiling point | 130 °C (266 °F; 403 K) decomposes | ||
miscible | |||
Solubility | very soluble in alcohol, ether | ||
Acidity (pKa) | 1.2 | ||
Conjugate base | Phosphinate | ||
Structure | |||
pseudo-tetrahedral | |||
Hazards | |||
Flash point | Non-flammable | ||
Safety data sheet (SDS) | JT Baker | ||
Related compounds | |||
Related phosphorus oxoacids
|
Phosphorous acid Phosphoric acid | ||
Related compounds
|
Sodium hypophosphite Barium hypophosphite | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Hypophosphorous acid (HPA), or phosphinic acid, is a phosphorus oxyacid and a powerful reducing agent with molecular formula H3PO2. It is a colorless low-melting compound, which is soluble in water, dioxane and alcohols. The formula for this acid is generally written H3PO2, but a more descriptive presentation is HOP(O)H2, which highlights its monoprotic character. Salts derived from this acid are called hypophosphites.[3]
HOP(O)H2 exists in equilibrium with the minor tautomer HP(OH)2. Sometimes the minor tautomer is called hypophosphorous acid and the major tautomer is called phosphinic acid.