{{위키데이터 속성 추적}}
{{Chembox
| Watchedfields = changed
| verifiedrevid = 476995365
| ImageFileL1_Ref = {{chemboximage|correct|??}}
| Name = 붕산<br>
| ImageFile = 
| ImageFileL1 = Boric-acid-2D.png
| ImageNameL1 = Structural formula
| ImageFileR1 = Boric-acid-3D-vdW.png
| ImageNameR1 = Space-filling model
| ImageFile2 = Boric acid.jpg
| ImageName2 = Boric acid crystals
| IUPACName = boric acid<br />trihydrooxidoboron<!-- This second IUPAC name has not been validated -->
| OtherNames = orthoboric acid,<br/>boracic acid,<br/>sassolite,<br/>optibor,<br/>borofax,<br/>trihydroxyborane,<br/>boron(III) hydroxide,<br/>boron Trihydroxide
| SystematicName = 
| Section1 = {{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 7346
| PubChem = 7628
| SMILES1 = [OH+]=[B-](O)O
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 42403
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/BH3O3/c2-1(3)4/h2-4H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = KGBXLFKZBHKPEV-UHFFFAOYSA-N
| CASNo = 10043-35-3
| CASNo_Ref = {{cascite|correct|CAS}}
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 33118
| SMILES = OB(O)O
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = R57ZHV85D4
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D01089
| InChI=1/BH3O3/c2-1(3)4/h2-4H
| InChIKey = KGBXLFKZBHKPEV-UHFFFAOYAI
| EINECS = 233-139-2
  }}
| Section2 = {{Chembox Properties
| H=3 | B=1 | O=3
| Appearance = White crystalline solid
| Density = 1.435 g/cm<sup>3</sup>
| Solubility = 2.52 g/100 mL (0&nbsp;°C) <br> 4.72 g/100 mL (20&nbsp;°C) <br> 5.7 g/100 mL (25&nbsp;°C) <br> 19.10 g/100 mL (80&nbsp;°C) <br> 27.53 g/100 mL (100&nbsp;°C)
| SolubleOther = Soluble in lower [[alcohol]]s <br> moderately soluble in [[피리딘]] <br> very slightly soluble in [[아세톤]]
| Solvent = other solvents
| MeltingPtC = 170.9
| BoilingPtC = 300
| ConjugateBase = [[Borate]]
| pKa = 9.24, 12.4, 13.3
| MagSus = -34.1·10<sup>−6</sup> cm<sup>3</sup>/mol
| LogP = -0.29<ref name="chemsrc">{{웹 인용|url=https://www.chemsrc.com/en/cas/10043-35-3_670326.html|title=boric_msds}}</ref>
  }}
| Section3 = {{Chembox Structure
| MolShape = Trigonal planar
| Dipole = Zero
  }}
| Section4 = 
| Section5 = 
| Section6 = {{Chembox Pharmacology
| ATCCode_prefix = S02
| ATCCode_suffix = AA03
| ATC_Supplemental = {{ATC|D08|AD}}
}}
| Section7 = {{Chembox Hazards
| GHSPictograms = {{GHS08}}
| NFPA-H = 1
| NFPA-F = 0
| NFPA-R = 0
| FlashPt = Non-flammable
| LD50 = 2660 mg/kg, oral (rat)
  }}
| Section8 = {{Chembox Related
| OtherCompounds = [[Boron trioxide]]<br/>[[Borax]]}}
}}

'''붕산'''(硼酸, {{llang|en|boric acid}})은 [[붕소]]를 중심원자로 하는 [[산소산]]이며, 화학식은 H<sub>3</sub>BO<sub>3</sub>이다. 무색·무취에 진주 광택이 있는 인편상의 결정이다. 더운 물에 잘 녹으며, 방부제·소독제로 쓰인다. 메타붕산·사붕산염, 오붕산염이 잘 알려져 있다. 천연으로 존재하는 것은 함수염이다. 무수염은 붕산과 금속산화물의 융해에 의해, 함수염은 수용액에서 얻을 수 있다.

== 생성 ==
:[[붕사]]에 [[염산]]을 작용시켜 얻는다.
:Na<sub>2</sub>B<sub>4</sub>O<sub>7</sub> · 10H<sub>2</sub>O + 2 HCl → 4H<sub>3</sub>BO<sub>3</sub> + 2NaCl + 5H<sub>2</sub>O

== 특성 ==
* H<sub>3</sub>BO<sub>3</sub> → HBO<sub>2</sub> + H<sub>2</sub>O
* 4HBO<sub>2</sub> → H<sub>2</sub>B<sub>4</sub>O<sub>7</sub> + H<sub>2</sub>O
* H<sub>2</sub>B<sub>4</sub>O<sub>7</sub> → 2B<sub>2</sub>O<sub>3</sub> + H<sub>2</sub>O
* H<sub>3</sub>BO<sub>3</sub> + H<sub>2</sub>O [[파일:Equilibrium.svg|10px]] H<sub>4</sub>BO<sub>4</sub><sup>-</sup> + H<sup>+</sup> (''K''<sub>a</sub> = 5.8x10<sup>−10</sup> mol/l; p''K''<sub>a</sub> = 9.24)
* 4H<sub>4</sub>BO<sub>4</sub><sup>-</sup> + 2 H<sup>+</sup> [[파일:Equilibrium.svg|10px]] B<sub>4</sub>O<span style="display:inline-block; margin-bottom:-0.3em; vertical-align:{{#if:7|-0.4em|0.8em}}; line-height:1.2em; {{#ifeq:|f|font-family:monospace,'Courier New';}} font-size:85%; text-align:{{#switch:|r=right|c=center|left}};">2−<br />7</span> + 9 H<sub>2</sub>O

== 결정 구조 ==
{|align="center" class="wikitable" style="margin: auto; text-align:center;"
|[[파일:Boric-acid-unit-cell-3D-balls.png|200px]]||[[파일:Boric-acid-layer-3D-balls.png|250px]]
|-
|붕산의 [[결정 구조|단위 격자]]||[[수소 결합]] (점선)은<br />붕산 분자가 고체 상태의 평행층을 형성한 것을 나타낸다
|}

== 각주 ==
{{각주}}

* {{글로벌세계대백과사전}}

== 외부 링크 ==
* {{위키공용분류-줄}}
* {{두피디아|101013000710309}}

{{붕소 화합물}}

{{전거 통제}}
{{토막글|화학}}

[[분류:무기산]]
[[분류:붕소 화합물]]
[[분류:살충제]]
[[분류:항진균제]]
[[분류:식품 보존료]]
[[분류:유변학]]