Back Fosforsuur Afrikaans حمض الفسفوريك Arabic Ácidu fosfórico AST فوسفوریک اسید AZB Фосфорна киселина Bulgarian ফসফরিক অ্যাসিড Bengali/Bangla Fosforna kiselina BS Àcid fosfòric Catalan Kyselina fosforečná Czech Asid ffosfforig Welsh

Phosphoric acid

This article is about orthophosphoric acid. For other acids commonly called "phosphoric acid", see Phosphoric acids and phosphates.
Not to be confused with Phosphorous acid.

Phosphoric acid
Structural formula of phosphoric acid, showing dimensions
Structural formula of phosphoric acid, showing dimensions
Ball-and-stick model
Ball-and-stick model
Space-filling model
Space-filling model
Names
IUPAC name
Phosphoric acid
Other names
Orthophosphoric acid, hydrogen phosphate
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.028.758 Edit this at Wikidata
EC Number
  • 231-633-2
E number E338 (antioxidants, ...)
KEGG
RTECS number
  • TB6300000
UNII
UN number 1805
  • InChI=1S/H3O4P/c1-5(2,3)4/h(H3,1,2,3,4) checkY
    Key: NBIIXXVUZAFLBC-UHFFFAOYSA-N checkY
  • InChI=1/H3O4P/c1-5(2,3)4/h(H3,1,2,3,4)
    Key: NBIIXXVUZAFLBC-UHFFFAOYAI
  • OP(=O)(O)O
Properties
H3PO4
Molar mass 97.994 g·mol−1
Appearance Colorless solid
Odor Odorless
Density 1.6845 g/cm3 (25 °C, 85%),[1] 1.834 g/cm3 (solid)[2]
Melting point 42.35 °C (108.23 °F; 315.50 K) anhydrous[12]
29.32 °C (84.78 °F; 302.47 K) hemihydrate[13]
Boiling point
  • 212 °C (414 °F)[3](only water evaporates)[4]
  • 392.2 g/(100 g) (−16.3 °C)
  • 369.4 g/(100 mL) (0.5 °C)
  • 446 g/(100 mL) (15 °C)[5]
  • 548 g/(100 mL) (20 °C)[6]
Solubility Soluble in ethanol
log P −2.15[7]
Vapor pressure 0.03 mmHg (20 °C)[8]
Conjugate base Dihydrogen phosphate
−43.8·10−6 cm3/mol[10]
  • 1.3420 (8.8% w/w aq. soln.)[11]
  • 1.4320 (85% aq. soln) 25 °C
Viscosity 2.4–9.4 cP (85% aq. soln.)
147 cP (100%)
Structure
Monoclinic
Tetrahedral
Thermochemistry[14]
145.0 J/(mol⋅K)
150.8 J/(mol⋅K)
−1271.7 kJ/mol
−1123.6 kJ/mol
Hazards
GHS labelling:
GHS05: Corrosive[15]
Danger
H290, H314[15]
P280, P305+P351+P338, P310[15]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
0
0
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
1530 mg/kg (rat, oral)[16]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 1 mg/m3[8]
REL (Recommended)
 TWA 1 mg/m3 ST 3 mg/m3[8]
IDLH (Immediate danger)
 1000 mg/m3[8]
Safety data sheet (SDS) ICSC 1008
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula H3PO4. It is commonly encountered as an 85% aqueous solution, which is a colourless, odourless, and non-volatile syrupy liquid. It is a major industrial chemical, being a component of many fertilizers.

The compound is an acid. Removal of all three H+ ions gives the phosphate ion PO3−4. Removal of one or two protons gives dihydrogen phosphate ion H2PO−4, and the hydrogen phosphate ion HPO2−4, respectively. Phosphoric acid forms esters, called organophosphates.[17]

The name "orthophosphoric acid" can be used to distinguish this specific acid from other "phosphoric acids", such as pyrophosphoric acid. Nevertheless, the term "phosphoric acid" often means this specific compound; and that is the current IUPAC nomenclature.

  1. ^ Christensen, J. H.; Reed, R. B. (1955). "Design and Analysis Data—Density of Aqueous Solutions of Phosphoric Acid Measurements at 25 °C". Ind. Eng. Chem. 47 (6): 1277–1280. doi:10.1021/ie50546a061.
  2. ^ "CAMEO Chemicals Datasheet – Phosphoric Acid". Archived from the original on 15 August 2019. Retrieved 15 August 2019.
  3. ^ "Phosphoric acid". www.chemspider.com. Archived from the original on 12 March 2020. Retrieved 3 March 2020.
  4. ^ Brown, Earl H.; Whitt, Carlton D. (1952). "Vapor Pressure of Phosphoric Acids". Industrial & Engineering Chemistry. 44 (3): 615–618. doi:10.1021/ie50507a050.
  5. ^ Seidell, Atherton; Linke, William F. (1952). Solubilities of Inorganic and Organic Compounds. Van Nostrand. Archived from the original on 11 March 2020. Retrieved 2 June 2014.
  6. ^ Haynes, p. 4.80
  7. ^ "phosphoric acid_msds". Archived from the original on 4 July 2017. Retrieved 2 May 2018.
  8. ^ a b c d NIOSH Pocket Guide to Chemical Hazards. "#0506". National Institute for Occupational Safety and Health (NIOSH).
  9. ^ Haynes, p. 5.92
  10. ^ Haynes, p. 4.134
  11. ^ Edwards, O. W.; Dunn, R. L.; Hatfield, J. D. (1964). "Refractive Index of Phosphoric Acid Solutions at 25 C.". J. Chem. Eng. Data. 9 (4): 508–509. doi:10.1021/je60023a010.
  12. ^ Greenwood, N. N.; Thompson, A. (1959). "701. The mechanism of electrical conduction in fused phosphoric and trideuterophosphoric acids". Journal of the Chemical Society (Resumed): 3485. doi:10.1039/JR9590003485.
  13. ^ Cite error: The named reference Ross was invoked but never defined (see the help page).
  14. ^ Haynes, p. 5.13
  15. ^ a b c Sigma-Aldrich Co., Phosphoric acid.
  16. ^ "Phosphoric acid". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  17. ^ Westheimer, F.H. (6 June 1987). "Why nature chose phosphates". Science. 235 (4793): 1173–1178 (see pp. 1175–1176). Bibcode:1987Sci...235.1173W. CiteSeerX 10.1.1.462.3441. doi:10.1126/science.2434996. PMID 2434996.
From Wikipedia, the free encyclopedia · View on Wikipedia

Developed by Nelliwinne