7664-38-2

Basic information

• Product Name: Orthophosphoric acid
• Synonyms: Phosphorsaeureloesungen;K-etchant;C 134 (acid);TG 434;FEMA No. 2900;trihydroxidooxidophosphorus;Phosphorsaeure;Phosphoric Acid Tech Grade;Phosphoric Acid (PAC-F);Phosphoric acid,;phosophoric Acid;ortho-phosphoric acid;Phosporic acid;3M Etching Liquid;Fosforzuuroplossingen;Fosforzuuroplossingen [Dutch];Wc-reiniger;tetraoxophosphoric acid;Acide phosphorique;Acido fosforico [Italian];orthophosphoric acid;o-Phosphoric acid;EPA Pesticide Chemical Code 076001;Acide phosphorique [French];Phosphorsaeureloesungen [German];Phosphoric acid [UN1805] [Corrosive];White phosphoric acid;Phosphoric Acid 85%
• CAS NO: 7664-38-2
• Molecular Formula: H₃O₄P
• Molecular Weight: 97.995181
• EINECS: 231-633-2
• Mol File: 7664-38-2.mol
• Article Data: 81

Chemical Properties

• Melting Point: 21℃
• Boiling Point: 157.999 °C at 760 mmHg
• Appearance: Clear liquid
• Density: 2.168 g/cm³
• PKA: 1.97±0.10(Predicted)
• Water Solubility: MISCIBLE
• CAS DataBase Reference: Orthophosphoric acid(CAS DataBase Reference)
• NIST Chemistry Reference: Orthophosphoric acid(7664-38-2)
• EPA Substance Registry System: Orthophosphoric acid(7664-38-2)

Safety Data

• Hazard Codes: C:Corrosive
• Statements: R34:
• Safety Statements: S26:; S45:
• RIDADR: 3453
• HazardClass: 8
• PackingGroup: III
• Hazardous Substances Data: 7664-38-2(Hazardous Substances Data)

Usage

General Description

Orthophosphoric acid, also known as phosphoric acid, is a clear, colorless liquid with a sharp, sour taste. It is a mineral acid commonly used in the production of fertilizers, detergents, and food products. In the food industry, it is used as a flavor enhancer and acidulant, as well as a pH regulator and preservative. In addition, orthophosphoric acid is used in the production of phosphate salts, which are essential in many industrial processes and products. It is also used in dental applications as an etchant for cleaning and roughening tooth surfaces before bonding procedures. Orthophosphoric acid is a strong acid, and it can cause burns and irritation upon contact with the skin and eyes, so proper handling and safety precautions are necessary when working with this chemical.

InChI:InChI=1/H3O4P/c1-5(2,3)4/h(H3,1,2,3,4)

Synthetic route

orthophosphoric acid (7664-38-2) + calcium carbonate → hydroxyapatite

Conditions	Yield
In water acid soln. neutralization with Ca-compd. soln. (phenolphthalein) at roomtemp. or at 80-90°C, suspn. stirring for 0.5 h; ppt. washing (water), drying at 80°C overnight or. ppt. ageing for 1 h, 5, 10, 15 or 30 d, sample part calcination at 900°C;

orthophosphoric acid (7664-38-2) + calcium hydroxide → hydroxyapatite

Conditions	Yield
In water acid soln. neutralization with Ca-compd. soln. (phenolphthalein) at roomtemp. or at 80-90°C, suspn. stirring for 0.5 h; ppt. washing (water), drying at 80°C overnight or. ppt. ageing for 1 h, 5, 10, 15 or 30 d, sample part calcination at 900°C;

Upstream product

• 66-72-8 pyridoxal 
• 7705-08-0 iron(III) chloride 
• 7758-99-8 copper(II) sulfate 
• 7647-01-0 hydrogenchloride 
• 5337-17-7 4-aminophenylphosphonic acid 
• 7732-18-5 water 
• 878-17-1 4-methylphenyl phosphorodichloridate 
• 762-04-9 phosphonic acid diethyl ester 
• 2465-65-8 O,O'-diethyl thiophosphoric acid 
• 2632-88-4 ethyl N,N'-tetraethyldiamidophosphite 
• 4428-95-9 foscarnet 
• 701-64-4 phosphoric acid monophenyl ester 
• 108-95-2 phenol 
• 1571-33-1 phenylphosphonate 

Downstream Products

• 59-67-6 nicotinic acid 
• 55-22-1 pyridine-4-carboxylic acid 
• 274-45-3 7-azaindolizine 
• 271-29-4 6-azaindole 
• 26138-64-7 3-acetyl-2,4-dihydroxyquinoline 
• 1128-05-8 3-acetylbenzothiophene 
• 2555-31-9 7-methoxy-4-phenyl-2H-chromen-2-one 
• 74803-15-9 2,3-diphenyl-1H-pyrrolo[2,3-b]pyridine 
• 101723-12-0 3-benzoyl-2-phenyl-cyclopentanone 
• 5061-91-6 9H-indeno(2,1-c)pyridin-9-one 
• 76-24-4 Alloxantin 
• 62-53-3 aniline 
• 64608-59-9 4-methylpyrrolo<1,2-a>pyrazine 
• 107-39-1 2,4,4-trimethyl-1-pentene 

Relevant articles and documents

Oxidative hydroxylation of phosphine in aqueous alcohol solutions of p-benzoquinone

The oxidation of phosphine in aqueous alcohol solution of benzoquinone in the presence of iodide ions is studied. Kinetic measurements, redox potentiometry, and gas chromatography are used to determine the kinetic regularities of the oxidative hydroxylati

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Thermal transformations of Co(H2PO4)2·2H2O

Thermal transformations of Co(H2PO4)2·2H2O in air, vacuum, water-vapor atmosphere were studied by the methods of DTA, XRD, paper chromatographic analyses and gravimetry. It was established that the removal of th

H3PO3 electrochemical behaviour on a bulk Pt electrode: adsorption and oxidation kinetics

Polybenzimidazole-type polymer doped with H3PO4 is commonly used as the proton-conductive phase in high-temperature proton-exchange membrane fuel cells. However, H3PO4 is not stable during fuel cell operation and undergoes reduction by hydrogen on a Pt surface to phosphorus compounds in a lower oxidation state, such as H3PO3. In this work the kinetics of H3PO3 oxidation on Pt electrode was studied, including an investigation of H4P2O6 as a possible oxidation intermediate. H3PO3 adsorption in hydrogen underpotential deposition region was described by a triple Langmuir isotherm corresponding to adsorption on specific Pt crystalline planes. Co-adsorption of hydrogen as well as SO42?, HSO4? ions decreased the total amount of adsorbed H3PO3. The determined apparent charge transfer coefficients of H3PO3 anodic oxidation on a metallic Pt surface were found to be concentration and temperature-dependent, indicating that the nature of the anodic process is complex. From chronopotentiometric measurements of H3PO3 and H4P2O6 oxidation on a preoxidised Pt surface it was concluded that, while H3PO3 is oxidised by means of a chemical reaction with PtOx, H4P2O6 undegoes anodic oxidation on the PtOx surface. According to voltammetry and bulk electrolysis experiments H4P2O6 is not formed as an intermediate product during electrochemical oxidation of H3PO3 on a metallic Pt surface.

PhnY and PhnZ comprise a new oxidative pathway for enzymatic cleavage of a carbon-phosphorus bond

The sequential activities of PhnY, an α-ketoglutarate/Fe(II)- dependent dioxygenase, and PhnZ, a Fe(II)-dependent enzyme of the histidine-aspartate motif hydrolase family, cleave the carbon-phosphorus bond of the organophosphonate natural product 2-aminoethylphosphonic acid. PhnY adds a hydroxyl group to the α-carbon, yielding 2-amino-1-hydroxyethylphosphonic acid, which is oxidatively converted by PhnZ to inorganic phosphate and glycine. The PhnZ reaction represents a new enzyme mechanism for metabolic cleavage of a carbon-phosphorus bond.

Efficient hydrolytic cleavage of phosphodiester with a lanthanide-based metal-organic framework

Hydrolysis of phosphate diesters has attracted substantial research efforts, not only in bio-organic chemistry, but also in inorganic chemistry. Herein, a lanthanide-based metal-organic framework was synthesized by incorporating a tetraphenylethylene moiety as the four-point connected node, Ce-TCPE (noted as 1). The structural analyses indicate that 1 exhibits 3D framework connected by the sharing carboxylate groups with two kinds of 1D rhombic channels when viewed along the c direction. Hydrolytic cleavage catalysis have been performed and showed that 1 could act as efficient heterogeneous catalyst for the hydrolytic cleavage of the phosphodiester BNPP (bis(p-nitrophenyl)phosphate) with the high activity and hydrolytic stability in a pseudo-first-order rate. DFT studies has also gain an insight analysis to elucidate the cleavage process.

Synthesis, crystal structure, IR, Raman spectroscopy, and DFT computation of metacarboxyphenyl ammonium dihydrogenomonophosphate (C7H4NH3OOH) H2PO4(m-C AMP)

The metacarboxyphenyl ammonium dihydrogenomonophosphate (C7H4NH3OOH) H2PO4 was synthesized and studied by a combination of single-crystal X-ray diffraction analysis, infrared, Raman vibrational spectroscopy, and density functional computation (DFT) calculation. This compound crystallizes in the monoclinic system, with the central space group P21/c. Its unit-cell dimensions are a = 12.9361 (7) (?), b = 11.7735 (6) (?), c = 6.5764 (4) (?), β = 102.668° (2), and V = 977.22 (9) ?3.The structure determined gives a clear description of the hydrogen bonds connecting the hydrogen phosphate H2PO4– with the organic matrix. The atomic arrangement of this compound is built up by symmetric (H4P2O8)2– dimers anions formed by two (H2PO4)– via hydrogen bonding O1—H…O3. Each (H2PO4)– aggregates with cation through hydrogen bond interactions of O–H…O(P) and N–H…O(P) types. The bands observed in the infrared and Raman spectra of (C7H4NH3OOH) H2PO4 are assigned based on the results obtained in the literature and based on the computational group analyses performed in the factor group C2h. Besides, the optimal molecular geometry, harmonic vibration frequencies, infrared intensities, and Raman scattering activities were calculated using the DFT approach performed with the Gaussian 09 program using the hybrid function B3LYP combining the three Becke parameters and the Lee-Yang-Parr exchange-correlation function using the 6-311 + G(d,p) base set. The highest occupied molecular orbital–lowest unoccupied molecular orbital properties and geometries of this compound were determined and discussed. The results of the calculated structural parameters are generally in agreement with the experimental investigations. The computational infrared and Raman spectra of the reference compound have been constructed.