lanthanum hydroxide

{{chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid =

| Name = Lanthanum(III) hydroxide

| ImageFile = File:La(OH)3.png

| ImageCaption = __ La³⁺ __ OH⁻

| ImageFile2 =

| ImageName =

| IUPACName = Lanthanum(III) hydroxide

| OtherNames =

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| 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)₃

| MolarMass = 189.93 g/mol

| Appearance =

| Density =

| Solubility =K_sp= 2.00·10⁻²¹

| MeltingPtC =

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| Section3 = {{Chembox Structure

| CrystalStruct = hexagonal

| SpaceGroup = P6₃/m, No. 176

| LattConst_a = 6.547 Å

| LattConst_c = 3.854 Å

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| Section5 =

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| Section7 = {{Chembox Hazards

| ExternalSDS =

| MainHazards = Irritant

| NFPA-H = 1

| NFPA-F =

| NFPA-R =

| NFPA-S =W

| FlashPt = Non-flammable

| GHS_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}}

| 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
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 salts such as lanthanum nitrate. This produces a gel-like precipitate that can then be dried in air.{{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 }}

:{{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.{{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}}

:{{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. In temperatures above 330 °C it decomposes into lanthanum oxide hydroxide (LaOOH), which upon further heating decomposes into lanthanum oxide ({{chem2|La2O3}}):{{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}}

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

:2 LaOOH $\mathrm{\xrightarrow [-H_2O]{\Delta} \ }$ {{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 prism.{{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}}

References

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]

Category:Lanthanum compounds

Category:Inorganic compounds

Category:Hydroxides