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Linear Formula: H3PO4
CAS Number: 7664-38-2
Molecular Weight: 98.00
Beilstein: 1921286
MDL number: MFCD00011340
Orthophosphoric acid refers to phosphoric acid.
Phosphoric Acid is a weak acid with chemical formula H3PO4.
APPLICATIONS
Food-grade Orthophosphoric acid (additive E338) is used to acidify foods and beverages such as various colas and jams, providing a tangy or sour taste.
The Orthophosphoric acid also serves as a preservative.
Soft drinks containing Orthophosphoric acid, which would include coke, are sometimes called phosphate sodas or phosphates.
Orthophosphoric acid in soft drinks has the potential to cause dental erosion.
Also, Orthophosphoric acid has the potential to contribute to the formation of kidney stones, especially in those who have had kidney stones previously.
Orthophosphoric acid is used in anti-rust treatment by phosphate conversion coating or passivation.
As a sanitizing agent in the dairy, food, and brewing industries, Orthophosphoric acid is used.
Orthophosphoric acid is used to prevent iron oxidation by means of the Parkerization process.
As a pH adjuster in cosmetics and skin-care products, Orthophosphoric acid is used.
Orthophosphoric acid is used as an external standard for phosphorus-31 nuclear magnetic resonance.
Moreover, Orthophosphoric acid is used in phosphoric acid fuel cells.
Orthophosphoric acid is used in activated carbon production.
Additionally, Orthophosphoric acid is used in compound semiconductor processing, to etch Indium gallium arsenide selectively with respect to indium phosphide.
Orthophosphoric acid is used in microfabrication to etch silicon nitride selectively with respect to silicon dioxide.
Orthophosphoric acid is used predominantly as an acidulant, almost exclusively in the production of carbonated beverages, although its use in foods bears controversy due to its effects on health.
Comparatively, Orthophosphoric acid is extremely inexpensive, possessing a characteristic flat sour taste that is reminiscent of citric acid.
Orthophosphoric acid is a relatively strong, dissociated acid, enabling it to easily acidify colas to the low desired pH (2.5) needed to establish proper carbonation, although its antimicrobial efficacy is far inferior to most organic acids, principally due to its dissociated state, which precludes ease of transport across the bacterial membrane.
Orthophosphoric acid is used in dentistry and orthodontics as an etching solution, to clean and roughen the surfaces of teeth where dental appliances or fillings will be placed.
Orthophosphoric acid is used in fertilizers, detergents, foods and beverages, water treatment, pickling and rust proofing metals, and for many other purposes.
Orthophosphoric acid (H3PO4) has many essential applications, in particular in the manufacture of fertilizers.
Many acids are derived from phosphate rocks by a wet process based on the reaction between phosphate rocks and acid solutions.
Orthophosphoric acid (H3PO4) is a medium-strong acid, but is also highly corrosive to ferrous or ferrous alloys.
Orthophosphoric acid is used as fertilizers – around 90% of phosphoric acid produced is used as fertilizers.
Moreover, Orthophosphoric acid is used in as a supplement feed for pigs, cattle, poultry.
Orthophosphoric acid is used in skincare products, cosmetics as a pH adjuster.
Orthophosphoric acid is used in brewing, food and dairy industries as a sanitizing agent.
Additionally, Orthophosphoric acid is used in beverages and food like jam and cola to acidify them.
Orthophosphoric acid is used to remove rust from the surface to metals.
Phosphoric acid, also called orthophosphoric acid, (H3PO4), the most important oxygen acid of phosphorus, used to make phosphate salts for fertilizers.
Orthophosphoric acid is also used in dental cements, in albumin derivatives preparation and in the sugar and textile industries.
Orthophosphoric acid is mainly used in the manufacture of various phosphate, such as ammonium phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, etc and condensation phosphate class.
Food-grade Orthophosphoric acid (additive E338) is used to acidify foods and beverages such as various colas.
Orthophosphoric acid provides a tangy or sour taste.
As an additive, Orthophosphoric acid is used to stabilize acidic aqueous solutions within a wanted and specified pH range.
Orthophosphoric acid may be used to remove rust by direct application to rusted iron, steel tools, or other surfaces.
As a pH adjuster, Orthophosphoric acid is used in cosmetics and skin-care products.
Orthophosphoric acid is used in dentistry and orthodontics as an etching solution, to clean and roughen the surfaces of teeth where dental appliances or fillings will be placed.
As a dispersing agent, Orthophosphoric acid is used in detergents and leather treatment.
DESCRIPTION
Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is an inorganic compound with the chemical formula H3PO4.
Moreover, Orthophosphoric acid is a colorless solid.
Orthophosphoric acid is commonly encountered as an 85% aqueous solution, which is a colourless, odourless, and non-volatile syrupy liquid.
Orthophosphoric acid 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.
Orthophosphoric acid forms esters, called organophosphates.
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.
Orthophosphoric acid is a colorless, odorless phosphorus-containing inorganic acid.
Moreover, Orthophosphoric acid is a sequestering agent which binds many divalent cations, including Fe++, Cu++, Ca++, and Mg++.
Orthophosphoric acid is used in dentistry and orthodontics as an etching solution, to clean and roughen the surfaces of teeth where dental appliances or fillings will be placed.
In addition, Orthophosphoric acid is a constituent in bone and teeth, and plays a role in many metabolic processes.
Orthophosphoric acid appears as a clear colorless liquid or transparent crystalline solid.
The pure solid of Orthophosphoric acid melts at 42.35°C and has a density of 1.834 g / cm3.
Liquid of Orthophosphoric acid is usually an 85% aqueous solution.
Orthophosphoric acid is Shipped as both a solid and liquid.
In addition to this, Orthophosphoric acid is Corrosive to metals and tissue.
Orthophosphoric acid is Used in making fertilizers and detergents and in food processing.
Orthophosphoric acid is a phosphorus oxoacid that consists of one oxo and three hydroxy groups joined covalently to a central phosphorus atom.
Additionally, Orthophosphoric acid has a role as a solvent, a human metabolite, an algal metabolite and a fertilizer.
Orthophosphoric acid is a conjugate acid of a dihydrogenphosphate and a phosphate ion.
Orthophosphoric acid is an acid-containing four atoms of oxygen, one atom of phosphorus, and three atoms of hydrogen.
Moreover, Orthophosphoric acid is also known as phosphoric(V) acid or orthophosphoric acid.
Orthophosphoric acid is present in teeth and bone and helps in metabolic processes.
In its liquid form, Orthophosphoric acid appears as a clear, colourless solution and in its solid form, Orthophosphoric acid appears as transparent, crystalline solid.
Orthophosphoric acid is an odourless, colourless, viscous liquid, possessing in a high degree the property of reddening litmus.
Orthophosphoric acid cannot be obtained free from water.
When Orthophosphoric acid is exposed to a red heat and afterward cooled it forms a transparent brittle glass.
This fusion should be effected in a platinum crucible since Orthophosphoric acid when heated to redness attacks either glass or porcelain.
The Orthophosphoric acid if examined after this exposure to heat is found although its composition remains the same to have acquired new properties.
On this account the name of para phosphoric has been given to it; while the term phosphoric is applied to designate the acid in the state first described.
Nitrate of silver yields with Orthophosphoric acid a yellow precipitate with para phosphoric acid a white one.
Albumen is coagulated by the latter but not by the former.
The orthophosphoric anhydrous acid is a white, crystalline solid which melts at 42.35 ° C.
If orthophosphoric acid is heated to temperatures of around 200 ° C, there will be a loss of constituent oxygen.
Dehydration produces a sequence of acids, ranging from pyrophosphoric acid, H4P2O7, to metaphosphoric acid.
Orthophosphoric acid is a crystalline liquid which is colourless and odourless.
And, Orthophosphoric acid gives a tangy taste to soft drinks, and prevents mold and bacteria from developing, which can easily multiply in a sugar solution.
Much of the acidity of soda also comes from the Orthophosphoric acid.
Becoming Orthophosphoric acid it is then processed again.
Phosphoric acid (also known as orthophosphoric acid or phosphoric(V) acid) is a weak acid with the chemical formula H3PO4.
Orthophosphoric acid refers to phosphoric acid, which is the IUPAC name for this compound.
The prefix ortho- is used to distinguish the acid from related phosphoric acids, called polyphosphoric acids.
Orthophosphoric acid is a non-toxic acid, which, when pure, is a solid at room temperature and pressure.
The most common source of phosphoric acid is an 85% aqueous solution; such solutions are colourless, odourless, and non-volatile.
The 85% solution is a syrupy liquid, but still pourable.
Although Orthophosphoric acid does not meet the strict definition of a strong acid, the 85% solution can still severely irritate the skin and damage the eyes.
Orthophosphoric acid is produced by the reaction of fluorapatite known as 'phosphate rock' 3Ca3 (PO4) 2.CaF2 with sulfuric acid.
Additionally, Orthophosphoric acid is a chemical that appeals to different sectors and has many uses.
Orthophosphoric acid is the main raw material input of phosphate fertilizer production.
Moreover, Orthophosphoric acid is mostly used in the production of phosphate fertilizers, the pharmaceutical industry, agriculture, metal cleaning, polishing and food for acidity regulation.
PRODUCTION
Orthophosphoric acid is produced industrially by one of two routes, wet processes and dry.
Orthophosphoric acid may be obtained by adding sulphuric acid to the phosphate of baryta suspended in water.
The sulphuric acid unites with the baryta forming an insoluble salt which precipitates while the phosphoric acid remains in solution.
When phosphorus is gradually added to nitric acid, Orthophosphoric acid is generated and remains mingled with the residual nitric acid
-Wet process
In the wet process, a phosphate-containing mineral such as calcium hydroxyapatite and fluorapatite are treated with sulfuric acid.
Ca5(PO4)3OH + 5 H2SO4 → 3 H3PO4 + 5 CaSO4 + H2O
Ca5(PO4)3F + 5 H2SO4 → 3 H3PO4 + 5 CaSO4 + HF
Calcium sulfate (gypsum, CaSO4) is a by-product, which is removed as phosphogypsum.
The hydrogen fluoride (HF) gas is streamed into a wet (water) scrubber producing hydrofluoric acid.
In both cases the Orthophosphoric acid solution usually contains 23–33% P2O5 (32–46% H3PO4).
It may be concentrated to produce commercial- or merchant-grade Orthophosphoric acid, which contains about 54–62% P2O5 (75–85% H3PO4).
Further removal of water yields superphosphoric acid with a P2O5 concentration above 70% (corresponding to nearly 100% H3PO4).
The Orthophosphoric acid from both processes may be further purified by removing compounds of arsenic and other potentially toxic impurities.
-Dry process
To produce food-grade phosphoric acid, phosphate ore is first reduced with coke in an electric arc furnace, to give elemental phosphorus.
Silica is also added, resulting in the production of calcium silicate slag.
Elemental phosphorus is distilled out of the furnace and burned with air to produce high-purity phosphorus pentoxide, which is dissolved in water to make Orthophosphoric acid.
Orthophosphoric acid can be conveniently prepared by dissolving P2O5 in water followed by boiling the solution to form a thick syrup.
P2O5 + 3H2O → 2H2PO4
Red phosphorus when heated with conc.HNO3 yields orthophosphoric acid.
P + 5HNO3 → H3PO4 + H2O + 5NO2
On a large scale, it is prepared by treating phosphorite rock with dil.H2SO4.
Ca3(PO4)2 + 3H2SO4 → 3CaSO4 + 2H3PO4
CHEMICAL PROPERTIES of ORTHOPHOSPHORIC ACID (H3PO4)
Orthophosphoric acid is a deliquescent solid, generally encountered as a viscous aqueous solution.
Orthophosphoric acid is weakly acidic, with three possible sequential deprotonation steps, forming phosphates.
Like carboxylic acids, Orthophosphoric acid can dimerize via a dehydration reaction to form phospho anhydrides.
Orthophosphoric acid is referred to as being tribasic, in that it has three possible dissociation steps.
As a result mono and disodium and potassium salts of Orthophosphoric acid are routinely used as pH buffers.
One of the most important reactions of Orthophosphoric acid and its derivatives is multimerization.
As with carboxylic acids, two Orthophosphoric acid molecules may combine with the loss of water to form a di phosphate ester also referred to as pyrophosphate.
However, as Orthophosphoric acid has further -OH functionalities triphosphates may also be formed.
Salts of Orthophosphoric acid are solid and many are relatively water-insoluble unless a strong mineral acid is present.
BASICITY OF ORTHOPHOSPHORIC ACID (H3PO4)
The basicity of acids is represented by the number of hydrogen atoms which can be replaced by electro – positive atoms.
Basicity of an acid is the number of hydrogen ions that can be produced by the ionization of one molecule of the acid in its aqueous solution.
An acid which produces three hydrogen or hydronium ions by the ionization of one molecule of the acid, is called a tribasic acid or tri protic acid.
For example, Orthophosphoric acid and H3PO3 are tribasic acids.
SAFETY
Although Orthophosphoric acid is not a strong acid, solutions can irritate the skin and damage the eyes.
A link has been shown between long-term regular cola intake and osteoporosis in later middle age in women (but not men).
At moderate concentrations Orthophosphoric acid solutions are irritating to the skin.
Contact with concentrated solutions of Orthophosphoric acid can cause severe skin burns and permanent eye damage.
PROPERTIES
Chemical formula: H3PO4
Molar mass: 97.994 g·mol−1
Appearance: Colorless solid
Odor: Odorless
Density: 1.6845 g/cm3 (25 °C, 85%), 1.834 g/cm3 (solid)
Melting point: 40–42.4 °C (104.0–108.3 °F; 313.1–315.5 K)
Boiling point: 212 °C (414 °F)
Solubility in water:
392.2 g/100 g (−16.3 °C)
369.4 g/100 mL (0.5 °C)
446 g/100 mL (15 °C)
548 g/100 mL (20 °C)
Solubility: Soluble in ethanol
log P: −2.15
Vapor pressure: 0.03 mmHg (20 °C)
Conjugate base: Dihydrogen phosphate
Magnetic susceptibility (χ): −43.8·10−6 cm3/mol
Refractive index (nD):
1.3420 (8.8% w/w aq. soln.)
1.4320 (85% aq. soln) 25 °C
Viscosity: 2.4–9.4 cP (85% aq. soln.)
147 cP (100%)
SYNONYMS
Phosphoric acid, Orthophosphoric acid,
O-phosphoric Acid
Phosphoric acid
7664-38-2
ORTHOPHOSPHORIC ACID
o-Phosphoric acid
Sonac
Wc-reiniger
Acidum phosphoricum
Phosphorsaeure
Evits
Acide phosphorique
Acido fosforico
Phosphorsaeureloesungen
Phosphoricum acidum
Polyphosphoric acids
Superphosphoric acid
Fosforzuuroplossingen
ortho-phosphoric acid
Phosphoric acid 75%
FEMA No. 2900
UNII-E4GA8884NN
poly(phosphoric acid)
Phosphoric acid 85%
Phosphoric acid [NF]
trihydroxidooxidophosphorus
H3PO4
E4GA8884NN
CHEBI:26078
MFCD00011340
NSC-80804
Phosphoric acid (NF)
NCGC00091005-01
Phosphoric acid solution
DSSTox_CID_4263
DSSTox_RID_77346
DSSTox_GSID_24263
9044-08-0
