| Identification | More | [Name]
Phosphorous acid | [CAS]
13598-36-2 | [Synonyms]
AURORA KA-1076
O-PHOSPHOROUS ACID
ORTHOPHOSPHOROUS
ORTHOPHOSPHOROUS ACID
PHOSPHONIC ACID
PHOSPHOROUS ACID
PHOSPHORUS ACID
dihydroxyphosphineoxide
orthophosphorus
Orthophosphorus acid
orthophosphorusacid
Phosphorous acid, ortho
Phosphorus trihydroxide
phosphorustrihydroxide
Trihydroxyphosphine
Phospohorous acid
Ortophosphorous acid
PHOSPHOROUS ACID 50 %
PhosphorousAcid>98%
PhosphorusAcid(Crystals)Pure | [EINECS(EC#)]
237-066-7 | [Molecular Formula]
H3O3P | [MDL Number]
MFCD00137258 | [Molecular Weight]
82 | [MOL File]
13598-36-2.mol |
| Chemical Properties | Back Directory | [Appearance]
white crystalline solid | [Melting point ]
73 °C
| [Boiling point ]
200 °C
| [density ]
1.651 g/mL at 25 °C(lit.)
| [vapor pressure ]
0.001Pa at 20℃ | [Fp ]
200°C | [storage temp. ]
0-6°C | [form ]
Crystals | [pka]
pK1 1.29; pK2 6.74(at 25℃) | [color ]
White | [Specific Gravity]
1.651 | [Stability:]
Stable. Incompatible with strong bases. Hygroscopic. | [Water Solubility ]
SOLUBLE | [Sensitive ]
Air Sensitive & Hygroscopic | [Merck ]
14,7346 | [CAS DataBase Reference]
13598-36-2(CAS DataBase Reference) | [NIST Chemistry Reference]
(HO)2HPO(13598-36-2) | [EPA Substance Registry System]
13598-36-2(EPA Substance) |
| Safety Data | Back Directory | [Hazard Codes ]
C | [Risk Statements ]
R22:Harmful if swallowed.
R35:Causes severe burns. | [Safety Statements ]
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) . | [RIDADR ]
UN 2834 8/PG 3
| [WGK Germany ]
1
| [RTECS ]
SZ6400000
| [F ]
3 | [TSCA ]
Yes | [HazardClass ]
8 | [PackingGroup ]
III | [HS Code ]
28092019 | [Safety Profile]
Moderately toxic by ingestion. When heated to decomposition at 200℃ it emits toxic fumes of POx and phosphme whch may ignite. See also PHOSPHINE. |
| Hazard Information | Back Directory | [General Description]
A white or yellow crystalline solid (melting point 70.1 deg C) or a solution of the solid. Density 1.651 g /cm3 . Contact may severely irritate skin, eyes, and mucous membranes. Toxic by ingestion, inhalation and skin absorption. | [Reactivity Profile]
PHOSPHOROUS ACID(13598-36-2) decomposes when heated to form phosphine, a gas that usually ignites spontaneously in air. Absorbs oxygen from the air to form phosphoric acid [Hawley]. Forms yellow deposits in aqueous solution that are spontaneously flammable upon drying. Reacts exothermically with chemical bases (for example: amines and inorganic hydroxides) to form salts. These reactions can generate dangerously large amounts of heat in small spaces. Dissolution in water or dilution of a concentrated solution with additional water may generate significant heat. Reacts in the presence of moisture with active metals, including such structural metals as aluminum and iron, to release hydrogen, a flammable gas. Can initiate the polymerization of certain alkenes. Reacts with cyanide compounds to release gaseous hydrogen cyanide. May generate flammable and/or toxic gases in contact with dithiocarbamates, isocyanates, mercaptans, nitrides, nitriles, sulfides, and strong reducing agents. Additional gas-generating reactions occur with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (to give SO2), and carbonates (to give CO2). | [Air & Water Reactions]
Deliquescent. Absorbs oxygen from the air very readily to form phosphoric acid [Hawley]. Soluble in water. | [Health Hazard]
TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. | [Fire Hazard]
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. | [Chemical Properties]
white crystalline solid | [Physical properties]
White crystalline mass; deliquescent; garlic-like odor; density 1.651 g/cm3 at 21°C; melts at 73.6°C; decomposes at 200°C to phosphine and phosphoric acid; soluble in water, about 310 g/100mL; K1 5.1x10-2 and K2 1.8x10-7; soluble in alcohol. | [Uses]
Phosphorus acid is used to prepare phosphite salts. It is usually sold as a 20% aqueous solution. | [Application]
Phosphorous acid (H3PO3, orthophosphorous acid) may be used as one of the reaction components for the synthesis of the following:
α-aminomethylphosphonic acids via Mannich-Type Multicomponent Reaction
1-aminoalkanephosphonic acids via amidoalkylation followed by hydrolysis
N-protected α-aminophosphonic acids (phospho-isosteres of natural amino acids) via amidoalkylation reaction | [Definition]
A colorless deliquescent solid that can be
prepared by the action of water on phosphorus(
III) oxide or phosphorus(III) chloride.
It is a dibasic acid producing the
anions H2PO3- and HPO3
2- in water. The
acid and its salts are slow reducing agents.
On warming, phosphonic acid decomposes
to phosphine and phosphoric(V) acid. | [Preparation]
Phosphorus acid can be prepared by the reaction of phosphorus trichloride with water: PCl3 + 3H2O → H3PO4 + 3HClThe reaction is violent. Addition of PCl3 should be extremely cautious and slow. The addition can be carried out safely in the presence of concentrated HCl. Alternatively, a stream of air containing PCl3 vapor is passed into icecold water and solid crystals of H3PO4 form. Alternatively, phosphorus acid can be prepared by adding phosphorus trichloride to anhydrous oxalic acid: PCl3 + 3(COOH）2 → H3PO3 + 3CO + 3CO2 + 3HCl In this reaction, all products except H3PO3 escape as gases leaving the liquid acid. Dissolution of phosphorus sesquioxide in water also forms phosphorus acid. When shaken with ice water, phosphorus acid is the only product . P4O6 + 6H2O → 4H3PO3 However, in hot water part of the phosphorus acid disproportionates to phosphoric acid and phosphorus or phosphine. | [Flammability and Explosibility]
Nonflammable | [Industrial uses]
This collector was developed recently and was used primarily as specific collector for cassiterite
from ores with complex gangue composition.On the basis of the phosphonic acid, Albright and Wilson had developed a range of collectors
mainly for flotation of oxidic minerals (i.e. cassiterite, ilmenite and pyrochlore).
Very little is known about the performance of these collectors. Limited studies conducted
with cassiterite and rutile ores showed that some of these collectors produce voluminous
froth but were very selective. |
| Questions And Answer | Back Directory | [Description]
Phosphorous acid is an intermediate in the preparation of other phosphorous compounds. It is a raw material to prepare phosphonates for water treatment such as iron and manganese control, scale inhibition and removal, corrosion control and chlorine stabilization. The alkali metal salts (phosphites) of phosphorous acid are being widely marketed either as an agricultural fungicide (e.g. Downy Mildew) or as a superior source of plant phosphorous nutrition. Phosphorous acid is used in stabilizing mixtures for plastic materials. Phosphorous acid is used for inhibiting high-temperature of corrosion-prone metal surfaces and to produce lubricants and lubricant additives. | [References]
[1] Allison E. McDonald, Bruce R. Grant and William C. Plaxton, Phosphite (Phosphorous Acid): Its Relevance in The Environment and Agriculture and Influence on Plant Phosphate Starvation Response, Journal of Plant Nutrition, 2001, vol. 24, 1505-1519
[2] Sai-Shek Young, Stabilizers for plastic materials, Patent, 1993
[3] Guido Sartori, Method for inhibiting corrosion using phosphorous acid, Patent,2004
[4] John R Morris, Lubricant containing a phosphorous acid ester-aldehyde condensation product, Patent, 1956
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