View source for Lanthanum hydroxide

{{chembox
| Verifiedfields = changed
| Watchedfields  = changed
| verifiedrevid  =
| Name           = Lanthanum(III) hydroxide
| ImageFile      = File:La(OH)3.png
| ImageCaption   = <span style="color:#C0C0C0; background-color:#C0C0C0;">__</span> La<sup>3+</sup>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="color:#FF0000;background-color:#FF0000;">__</span> OH<sup>−</sup>
| ImageFile2     =
| ImageName      =
| IUPACName      = Lanthanum(III) hydroxide
| OtherNames     =
| SystematicName =
| Section1       = {{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 14507-19-8
| ChemSpiderID = 119053
| EINECS = 238-510-2
| PubChem = 135111
| PubChem_Comment =
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 7PTY21U5YN
| StdInChI_Ref =
| StdInChI = 1S/La.3H2O/h;3*1H2
| StdInChIKey = YXEUGTSPQFTXTR-UHFFFAOYSA-K
| SMILES = [OH-].[OH-].[OH-].[La+3]
  }}
| Section2       = {{Chembox Properties
| Formula = La(OH)<sub>3</sub>
| MolarMass = 189.93 g/mol
| Appearance =
| Density =
| Solubility =K<sub>sp</sub>= 2.00·10<sup>−21</sup>
| MeltingPtC =
| MeltingPt_notes =
| BoilingPtC =
| BoilingPt_notes =
| BandGap =
}}
| Section3       = {{Chembox Structure
| CrystalStruct = hexagonal
| SpaceGroup = P6<sub>3</sub>/m, No. 176
| LattConst_a = 6.547 Å
| LattConst_c = 3.854 Å
  }}
| Section4       =
| Section5       =
| Section6       =
| Section7       = {{Chembox Hazards
| ExternalSDS =
| MainHazards = Irritant
| NFPA-H = 1
| NFPA-F =
| NFPA-R =
| NFPA-S =W
| FlashPt = Non-flammable
| GHS_ref=<ref>{{cite web |title=C&L Inventory |url=https://echa.europa.eu/information-on-chemicals/cl-inventory-database/-/discli/details/123392 |website=echa.europa.eu}}</ref>
| GHSPictograms = {{GHS05}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|314}}
| PPhrases = {{P-phrases|260|264|280|301+330+331|303+361+353|304+340|305+351+338|310|321|363|405|501}}
  }}
| Section8       = {{Chembox Related
| OtherAnions = [[Lanthanum(III) chloride]]
| OtherCations = [[Cerium(III) hydroxide]]<br>[[Actinium(III) hydroxide]]
| OtherCompounds =
  }}
}}

'''Lanthanum hydroxide''' is {{chem|La(OH)|3}}, a [[hydroxide]] of the [[rare-earth element]] [[lanthanum]].

==Synthesis==

Lanthanum hydroxide can be obtained by adding an [[alkali]] such as [[ammonia]] to aqueous solutions of [[lanthanum salt]]s such as [[lanthanum nitrate]].  This produces a gel-like [[precipitate]] that can then be dried in air.<ref name="Shkolnikov2009">{{cite journal | author = E.V. Shkolnikov | title = Thermodynamic Characterization of the Amphoterism of Hydroxides and Oxides of Scandium Subgroup Elements in Aqueous Media | journal = Russian Journal of Applied Chemistry | year = 2009 | volume = 82 | issue = 2 | pages = 2098–2104 | doi = 10.1134/S1070427209120040 | s2cid = 93220420 }}</ref>

:{{chem2|La(NO3)3 + 3 NH4OH -> La(OH)3 + 3 NH4NO3}}

Alternatively, it can be produced by [[hydration reaction]] (addition of water) to [[lanthanum oxide]].<ref>{{cite journal | doi = 10.1016/S1002-0721(06)60139-7| title = Preparation of La(OH)3 and La2O3 with Rod Morphology by Simple Hydration of La2O3| year = 2006| last1 = Ding| first1 = Jiawen| last2 = Wu| first2 = Yanli| last3 = Sun| first3 = Weili| last4 = Li| first4 = Yongxiu| journal = Journal of Rare Earths| volume = 24| issue = 4| pages = 440–442}}</ref>

:{{chem2|La2O3 + 3 H2O -> 2 La(OH)3}}

==Characteristics==
Lanthanum hydroxide does not react much with alkaline substances, however is slightly soluble in acidic solution.<ref name="Shkolnikov2009"/> In temperatures above 330&nbsp;°C it decomposes into lanthanum oxide hydroxide (LaOOH), which upon further heating decomposes into lanthanum oxide ({{chem2|La2O3}}):<ref>{{cite book | author = Michael E. Brown, Patrick Kent Gallagher | title = Handbook of Thermal Analysis and Calorimetry | date = 2008 | page = 482 | publisher = Elsevier | isbn = 978-0-44453123-0}}</ref>

:{{chem2|La(OH)3}} <math>\mathrm{ \xrightarrow [-H_2O]{330\ ^{o}C} \ }</math> LaOOH

:2 LaOOH <math>\mathrm{\xrightarrow [-H_2O]{\Delta} \ }</math> {{chem2|La2O3}}

Lanthanum hydroxide crystallizes in the [[hexagonal crystal system]]. Each lanthanum ion in the crystal structure is surrounded by nine hydroxide ions in a [[Tricapped trigonal prismatic molecular geometry|tricapped trigonal prism]].<ref>{{Cite journal|last1=Beall|first1=G.W.|last2=Milligan|first2=W.O.|last3=Wolcott|first3=Herbert A.|date=1977|title=Structural trends in the lanthanide trihydroxides|journal=Journal of Inorganic and Nuclear Chemistry|language=en|volume=39|issue=1|pages=65–70|doi=10.1016/0022-1902(77)80434-X}}</ref>

==References==
{{reflist}}

==External links==
* {{cite web|url=http://www.rsc.org/periodic-table/element/57/lanthanum|title=Lanthanum - Element information, properties and uses - Periodic Table|work=rsc.org}}
* [http://physchem.ox.ac.uk/MSDS/LA/lanthanum_oxide.html External MSDS 1]
* [https://web.archive.org/web/20120331182447/http://camel.conncoll.edu/offices/envhealth/MSDS/botany/L/Lanthanum-oxide.html External MSDS 2]
* [https://web.archive.org/web/20150924082657/http://www.prysmag.com/upfile/pdf/Prysmag_Lanthanum_Rare_Earth_Oxide_La2O3_MSDS.pdf  Lanthanum Oxide MSDS]

{{Lanthanum compounds}}
{{Hydroxides}}

{{DEFAULTSORT:Lanthanum(Iii) Hydroxxide}}
[[Category:Lanthanum compounds]]
[[Category:Inorganic compounds]]
[[Category:Hydroxides]]


{{inorganic-compound-stub}}