Izvorni kod stranice Fosforna kiselina

{{Chembox-lat
| ImageFile = Phosphoric-acid-2D-dimensions.png
| ImageSize = 160px 
| ImageName = strukturna formula
| ImageFile1 = Phosphoric-acid-3D-vdW.png
| ImageSize1 = 140px 
| ImageName1 = model
| IUPACName = trihidroksidooksidofosfor<br />fosforna kiselina
| OtherNames = ortofosforna kiselina
| Section1 = {{Chembox Identifiers-lat
| MeSHName =Phosphoric+acid
| PubChem = 1004
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = E4GA8884NN
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D05467
| InChI = 1/H3O4P/c1-5(2,3)4/h(H3,1,2,3,4)
| InChIKey = NBIIXXVUZAFLBC-UHFFFAOYAI
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 26078
| SMILES = OP(=O)(O)O
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 1187
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/H3O4P/c1-5(2,3)4/h(H3,1,2,3,4)
|  StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
|  Beilstein = 
|  Gmelin = 
|  3DMet = 
| StdInChIKey = NBIIXXVUZAFLBC-UHFFFAOYSA-N
| CASNo = 7664-38-2
| CASNo_Ref = {{cascite|correct|CAS}}
| CASOther = <br />16271-20-8 (hemihydrate)
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 979
| EINECS = 231-633-2
| UNNumber = 1805
| RTECS = TB6300000
}}
| Section2 = {{Chembox Properties-lat
| Formula = H<sub>3</sub>PO<sub>4</sub>
| MolarMass = 98.0 g/mol
| Appearance = bela čvrsta supstanca ili<br />bezbojna viskozna tečnost (>42&nbsp;°C)
| Density = 1.685 g/ml (tečnost)
| MeltingPtC = 42.35
| BoilingPtC = 158
| Boiling_notes = ''razlaže se''
| pKa = 2.12, 7.21, 12.67
| Viscosity = 85% vodeni rastvor<br /> ? cP
}}
| Section4 = {{Chembox Thermochemistry
|   DeltaHf = -1288&nbsp;kJ·mol<sup>−1</sup><ref name=b1>{{cite book| author = Zumdahl, Steven S.|title =Chemical Principles 6th Ed.| url = https://archive.org/details/chemicalprincipl0000zumd_u9g0| publisher = Houghton Mifflin Company| year = 2009| isbn = 0-618-94690-X|page=A22}}</ref>
|   Entropy = 158&nbsp;J·mol<sup>−1</sup>·K<sup>−1</sup><ref name=b1/>
}}
| Section7 = {{Chembox Hazards-lat
|   EUClass = Korozivna ('''C''')
|   RPhrases = {{R34}}
|   SPhrases = {{(S1/2)}}, {{S26}}, {{S45}}
}}
| Section8 = {{Chembox Related-lat
|   Function = fosforne kiseline
|   OtherFunctn = [[hipofosforna kiselina]]<br />[[fosforasta kiselina]]<br />[[pirofosforna kiselina]]<br />[[tripolifosforna kiselina]]<br />[[hipofosforasta kiselina]]<br />[[perfosforna kiselina]]<br />[[permonofosforna kiselina]]
}}
}}

'''Fosfatna kiselina''' ili ortofosforna kiselina je triprotonska oksikiselina [[fosfor]]a čija je [[kemijska formula|hemijska formula]] H<sub>3</sub>PO<sub>4</sub>.<ref name="CRC">{{RubberBible87th}}</ref> Njene [[sol]]i nazivaju se fosfati.

== Dobivanje ==
Fosfatna kiselina se dobija rastvaranjem [[fosfor (V) oksid]]a u vodi:
:P<sub>4</sub>O<sub>10</sub> (s) + 6 H<sub>2</sub>O → 4 H<sub>3</sub>PO<sub>4</sub>

Osim toga, može se dobiti i djelovanjem [[sumporna kiselina|sumporne kiseline]] na [[kalcijum fosfat]]:
:Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub> (s) + 3 H<sup>+</sup> + 3 HSO<sub>4</sub><sup>-</sup> → 3 CaSO<sub>4</sub> + 2H<sub>3</sub>PO<sub>4</sub>hh

== Osobine ==
Fosfatna kiselina je slaba triprotonska [[kiselina]]. Konstante ionizacije su:

:<math>\mathrm{H_3PO_{4(s)} + H_2O_{(l)} \rightleftharpoons}</math> <math>\mathrm{H_3O^+_{(aq)} + H_2PO^-_{4(aq)}, \ K_{a1} = 7,5 \cdot 10^{-3}}</math>
:<math>\mathrm{H_2PO^-_{4(aq)}+ H_2O_{(l)} \rightleftharpoons}</math> <math>\mathrm{H_3O^+_{(aq)} + HPO^{2-}_{4(aq)}, \ K_{a2} = 6,2 \cdot 10^{-8}}</math>
:<math>\mathrm{HPO^{2-}_{4(aq)}+ H_2O_{(l)}  \rightleftharpoons}</math> <math>\mathrm{H_3O^+_{(aq)} + PO^{3-}_{4(aq)}, \ K_{a3} = 2,14 \cdot 10^{-13}}</math>

== Upotreba ==
Najvažnija upotreba soli fosforne kiseline je u proizvodnji vještačkih [[đubrivo|đubriva]].

== Reference ==
{{reflist|2}}

== Vanjske veze ==
{{Portal-lat|Hemija}}
{{Commonscat|Phosphoric acid}}
* [http://www.inchem.org/documents/icsc/icsc/eics1008.htm International chemical safety card 1008]
* [http://www.npi.gov.au/substances/phosphoric-acid/index.html National pollutant inventory – Phosphoric acid fact sheet]
* [http://www.cdc.gov/niosh/npg/npgd0506.html NIOSH Pocket guide to chemical hazards]
* [http://www2.iq.usp.br/docente/gutz/Curtipot_.html Excel spreadsheet containing phosphoric acid titration curve, distribution diagram and buffer pH calculation]

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[[Kategorija:Fosforne oksokiseline]]
[[Kategorija:Neorganske kiseline]]
[[Kategorija:Prehrambeni antioksidansi]]
[[Kategorija:Jedinjenja vodonika]]
[[Kategorija:Ukusi]]