Product Description of Phosphoric Acid CAS# 7664-38-2
Phosphoric acid, also known as orthophosphoric acid (molecular formula H3PO4), is available as a colorless, transparent, viscous liquid or orthorhombic crystal, odorless and very sour. An 85% solution appears as a colorless or slightly light-colored viscous liquid. It has a melting point of 42.35°C, specific gravity of 1.70, and a high boiling point, being fully miscible with water. Upon boiling at 213°C (losing half its water), it forms pyrophosphoric acid, and at 300°C, it converts to metaphosphoric acid. The relative density is 181.834.
Phosphoric acid is easily soluble in water and ethanol and is classified as a medium-strong inorganic acid—weaker than strong acids such as sulfuric, hydrochloric, and nitric acids, but stronger than weak acids like acetic, boric, and carbonic acids. Reaction with sodium carbonate at varying pH levels produces different acid salts.
It can irritate skin, cause inflammation, and damage body tissues, and concentrated phosphoric acid may erode porcelain when heated. Being hygroscopic, it should be stored in a sealed container. Commercially, phosphoric acid is available as an 82% viscous solution, with high viscosity attributed to hydrogen bonding in the solution.
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Phosphoric acid Chemical Properties
Melting point | ~40 °C(lit.) |
Boiling point | 158 °C(lit.) |
density | 1.685 g/mL at 25 °C(lit.) |
vapor density | 3.4 (vs air) |
vapor pressure | 2.2 mm Hg ( 20 °C) |
refractive index | n20/D 1.433 |
FEMA | 2900 | PHOSPHORIC ACID |
storage temp. | no restrictions. |
solubility | H2O: soluble |
pka | 2.1-7.2-12.3(at 25℃) |
form | Solid or Viscous Liquid |
Specific Gravity | 1.7 |
color | ≤10(APHA) |
PH | 3.06(1 mM solution);2.26(10 mM solution);1.63(100 mM solution); |
Odor | Odorless |
PH Range | 1.5 |
Water Solubility | MISCIBLE |
λmax | λ: 260 nm Amax: ≤0.05 |
λ: 280 nm Amax: ≤0.04 |
Merck | 147344 |
BRN | 1921286 |
Exposure limits | TLV-TWA 1 mg/m3 (ACGIH, MSHA, and OSHA); TLV-STEL 3 mg/m3 (ACGIH). |
Dielectric constant | 61 |
InChIKey | NBIIXXVUZAFLBC-UHFFFAOYSA-N |
LogP | -2.15 |
CAS DataBase Reference | 7664-38-2(CAS DataBase Reference) |
NIST Chemistry Reference | Phosphoric acid(7664-38-2) |
EPA Substance Registry System | Phosphoric acid (7664-38-2) |
Safety Information
Hazard Codes | C,Xn,T,F |
Risk Statements | 34-35-22-39/23/24/25-36/38-23/24/25-11 |
Safety Statements | 7-16-26-36/37-45-36/37/39-1/2-24/25 |
RIDADR | UN 3453 8/PG 3 |
WGK Germany | 3 |
RTECS | TB6300000 |
F | 46091 |
TSCA | Yes |
HS Code | 2809 20 00 |
HazardClass | 8 |
PackingGroup | III |
Hazardous Substances Data | 7664-38-2(Hazardous Substances Data) |
Toxicity | ADI 0 to 70 mg / kg (total phosphate content in terms of phosphorus, FAO / WHO, 2001). |
GRAS (FDA, § 182.1073, 2000). |
LD501530mg / kg (rat, oral). |
In case of daily intake of 2 ~ 4 g, it can cause mild diarrhea. The amount of sour agent used as a cola drink is 0.02% to 0.06%. |
IDLA | 1,000 mg/m3 |
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Product Application of Phosphoric Acid CAS# 7664-38-2
Wet-process phosphoric acid is primarily used in the production of various phosphates, including ammonium phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, and condensed phosphates. Refined phosphoric acid is employed to manufacture calcium hydrogen phosphate for animal feed.
It is widely used in metal treatment, such as phosphating of metal surfaces, and in the preparation of electrolytic and chemical polishing solutions for aluminum products. In the pharmaceutical industry, it is used to produce sodium glycerophosphate, iron phosphate, and zinc phosphate as a dental filling adhesive.
Phosphoric acid also serves as a catalyst for phenolic resin condensation, a desiccant for dyes and intermediates, and is applied in the printing industry to prepare cleaning solutions for offset color printing plates. It is used in matchstick impregnation liquids and in the metallurgical industry to produce phosphoric acid refractory mud, extending the service life of steelmaking furnaces.
Additionally, it acts as a coagulant for rubber slurry, a raw material for inorganic adhesives, and a metal anti-rust agent in the coating industry.
![Phosphoric Acid（industrial grade) CAS#7664-38-2]( "Phosphoric Acid（industrial grade) CAS#7664-38-2")
