695017

Phosphoric acid

ACS reagent, ≥85 wt. % in H₂O

• Synonym(s): Orthophosphoric acid
• Linear Formula: H₃PO₄
• CAS Number: 7664-38-2
• Molecular Weight: 98.00
• Beilstein: 1921286
• EC Number: 231-633-2
• MDL number: MFCD00011340
• UNSPSC Code: 12352106
• PubChem Substance ID: 329761708
• NACRES: NA.21

Properties

• grade: ACS reagent
• vapor density: 3.4 (vs air)
• vapor pressure: 2.2 mmHg ( 20 °C); 5 mmHg ( 25 °C)
• Assay: ≥85% H₃PO₄ basis (by NaOH, titration)
• form: liquid
• concentration: ≥85 wt. % in H₂O
• technique(s): NMR: suitable
• impurities: reducing substances, passes test; ≤0.001% volatile acids (as CH₃COOH)
• color: APHA: ≤10
• bp: 158 °C (lit.)
• mp: ~40 °C (lit.)
• density: 1.685 g/mL at 25 °C (lit.)
• anion traces: chloride (Cl^-): ≤3 ppm; nitrate (NO₃^-): ≤5 ppm; sulfate (SO₄^2-): ≤0.003%
• cation traces: As: ≤1 ppm; Ca: ≤0.002%; Fe: ≤0.003%; K: ≤0.005%; Mg: ≤0.02%; Mn: ≤0.5 ppm; Na: ≤0.025%; Sb: ≤0.002%; heavy metals: ≤0.001% (by ICP)
• SMILES string: OP(O)(O)=O
• InChI: 1S/H3O4P/c1-5(2,3)4/h(H3,1,2,3,4)
• InChI key: NBIIXXVUZAFLBC-UHFFFAOYSA-N
• Gene Information: human ... SRC(6714)

Description

General description

Phosphoric acid (H₃PO₄) is useful in industry for treating the metal surfaces to obtain better adhesion of paint and resin coatings.

Application

Phosphoric acid may be employed as standard for the determination of phosphorus-31 nuclear magnetic resonance (³¹P NMR) chemical shifts of the common phospholipids. It may be employed in the following studies:

• As external standard for the analysis of lipid composition of human white matter by ³¹P NMR spectroscopy.
• As external standard during the acid-labile phosphorylation of histone H4 by ³¹P NMR spectroscopy.
• As reference standard to investigate the surface species present on silica/alumina-supported sodium phosphates by pre- and postreaction MAS³¹P-NMR and FTIR spectroscopies.
• As catalyst in the vapor-phase Fries rearrangement of phenylacetate at 623K over a series of surface modified and unmodified ZSM-5.

Other Notes

Concentrated phosphoric acid is approx. 85% H₃PO₄ (aqueous).

Safety Information

• Pictograms: GHS05,GHS07
• Signal Word: Danger
• Hazard Statements: H290,H302,H314
• Precautionary Statements: P234 - P280 - P301 + P312 - P303 + P361 + P353 - P304 + P340 + P310 - P305 + P351 + P338
• Hazard Classifications: Acute Tox. 4 Oral - Eye Dam. 1 - Met. Corr. 1 - Skin Corr. 1B
• Storage Class Code: 8B - Non-combustible corrosive hazardous materials
• WGK: WGK 1
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable