Phosphoric acid CAS#7664-38-2Phosphoric acid CAS#7664-38-2
Phosphoric acid is also called orthophosphoric acid (molecular formula H3PO4). The pure product is a colorless, transparent, viscous liquid or orthorhombic crystal, odorless and very sour. 85% phosphoric acid is a colorless, transparent or slightly light-colored, viscous liquid. Melting point 42.35℃, specific gravity 1.70, high boiling point acid, miscible with water in any ratio, boiling point 213℃ (lose 1/2 water), then pyrophosphoric acid is generated. When heated to 300℃, it becomes metaphosphoric acid. Relative density 181.834. It is easily soluble in water and ethanol. Phosphoric acid is a common inorganic acid and a medium-strong acid. Its acidity is weaker than strong acids such as sulfuric acid, hydrochloric acid and nitric acid, but stronger than weak acids such as acetic acid, boric acid and carbonic acid. When phosphoric acid reacts with sodium carbonate at different pH, different acid salts can be generated. It can irritate the skin and cause inflammation, and damage body tissues. Concentrated phosphoric acid has an erosive effect when heated in porcelain. It is hygroscopic and should be stored in a sealed container. Commercially available phosphoric acid is a viscous concentrated solution containing 82% H3PO4. The high viscosity of phosphoric acid solution is due to the presence of hydrogen bonds in the solution.
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 | 14,7344 |
| BRN | 1921286 |
| Exposure limits | TLV-TWA 1 mg/m3 (ACGIH, MSHA, and OSHA); TLV-STEL 3 mg/m3 (ACGIH). |
| Dielectric constant | 61.0 |
| 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 | 3-10 |
| 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%. |
