:Lead(II) hydroxide
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| IUPACName = Lead(II) hydroxide
| OtherNames = {{ubl|Lead hydroxide|Plumbous hydroxide}}
| Section1 = {{Chembox Identifiers
| CASNo = 19783-14-3
| CASNo_Ref = {{cascite|correct|CAS}}
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 8035300
| EINECS = 243-310-3
| InChI = 1/2H2O.Pb/h2*1H2;/q;;+2/p-2
| InChIKey = VNZYIVBHUDKWEO-NUQVWONBAE
| SMILES = [OH-].[OH-].[Pb+2]
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/2H2O.Pb/h2*1H2;/q;;+2/p-2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = VNZYIVBHUDKWEO-UHFFFAOYSA-L
| PubChem = 9859601
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| Section2 = {{Chembox Properties
| Formula = {{chem2|Pb(OH)2}}
| H=2|Pb=1|O=2
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| Solubility = 0.0155 g/(100 mL) (20 °C)Handbook of Chemistry and Physics, 1st edition, 2000, CRC Press {{ISBN|0-8493-0740-6}}
| SolubilityProduct = 10−19.85 to 10−14.9{{cite book |title=Internal Corrosion of Water Distribution Systems |edition=2nd |publisher=American Water Works Association | year=1996 | isbn=978-1-61300-170-7 |url=https://books.google.com/books?id=F5hKYcQSuSkC&pg=PA178 |page=178}}
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| Section7 = {{Chembox Hazards
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| GHSPictograms = {{GHS06}}{{GHS07}}{{GHS09}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|302|332|351|360|373|410}}
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| NFPA-H = 2
| NFPA-F = 0
| NFPA-R = 0
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| Section8 = {{Chembox Related
| OtherAnions =
| OtherCations = {{ubl|Germanium(II) hydroxide|Tin(II) hydroxide|Mercury(II) hydroxide}}
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Lead(II) hydroxide is an inorganic compound with the formula {{chem2|Pb(OH)2}}. The material has not been isolated but its existence has been inferred as an ill-defined component of solutions of Pb(II). "Lead does not appear to form a simple hydroxide, Pb(OH)2," however.{{Greenwood&Earnshaw2nd|page=387}} Instead it forms oxides and oxy-hydroxides.
Preparation
Addition of hydroxide to a solution of a lead(II) salt, a hydrated lead oxide {{chem2|PbO*xH2O}} (with x < 1) is obtained. Careful hydrolysis of lead(II) acetate solution yields a crystalline product with a formula {{chem2|6PbO*2H2O}} or {{chem2|Pb6O4(OH)4}}.Von Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman, "Inorganic Chemistry", Academic Press, 2001 [https://books.google.com/books?id=Mtth5g59dEIC&dq=%22lead%28II%29+hydroxide%22&pg=PA916 (Google books)]. This material is a cluster compound, consisting of an octahedron of Pb centers, each face of which is capped by an oxide or a hydroxide. The structure is reminiscent of the {{chem2|Mo6S8}} subunit of the Chevrel phases.{{cite journal|title=Structure of Tin(II) "Hydroxide" and Lead(II) "Hydroxide|author1=R. A. Howie|author2=W. Moser|journal=Nature|volume=219|pages=372–373|year=1968|issue=5152|doi=10.1038/219372a0|bibcode=1968Natur.219..372H|s2cid=45007541}}
Reactions
In aqueous solution, lead(II) hydroxide is a somewhat weak base, forming lead(II) ion, {{chem2|Pb(2+)}}, under weakly acidic conditions. This cation hydrolyzes and, under progressively increasing alkaline conditions, it becomes somewhat weak acid, and it forms {{chem2|Pb(OH)+}}, {{chem2|Pb(OH)2}}(aqueous), {{chem2|Pb(OH)3−}}, and other species, including several polynuclear species, e.g., {{chem2|Pb4(OH)4(4+)}}, {{chem2|Pb3(OH)4(2+)}}, {{chem2|Pb6O(OH)6(4+)}}.
Upon heating to decomposition temperatures, it forms lead oxide (PbO) in the yellow form, litharge.
History
The name lead hydrate has sometimes been used in the past but it is unclear whether this refers to {{chem2|Pb(OH)2}} or {{chem2|PbO*xH2O}}.{{Cite web|url=https://patents.google.com/patent/US527830|title=Process of treating lead hydrate produced by electrolysis}}{{Cite web|url=https://patents.google.com/patent/US496109|title=Process of manufacturing white lead}} In 1964 it was believed that such a simple compound did not exist, as lead basic carbonate ({{chem2|2PbCO3*Pb(OH)2}}) or lead(II) oxide (PbO) was encountered where lead hydroxide was expected.{{cite journal | author = G. Todd and E. Parry | title = Character of Lead Hydroxide and Basic Lead Carbonate | journal = Nature | volume = 202 | pages = 386–387 | year = 1964 | doi = 10.1038/202386a0 | issue=4930| bibcode = 1964Natur.202..386T | s2cid = 44941178}} This has been a subject of considerable confusion in the past. However, subsequent research has demonstrated that lead(II) hydroxide does indeed exist as one of a series of lead hydroxides.{{cite journal | author = W. Nimal Perera, Glenn Hefter, and Pal M. Sipos | title = An Investigation of the Lead(II)−Hydroxide System | journal = Inorganic Chemistry | volume = 40 | issue=16 | pages = 3974–3978 | year = 2001 | doi = 10.1021/ic001415o| pmid = 11466056}}
References
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External links
- [https://www.atsdr.cdc.gov/csem/csem.html Case Studies in Environmental Medicine - Lead Toxicity]
- [https://www.atsdr.cdc.gov/toxfaqs/tfacts13.pdf ToxFAQs: Lead]
- [https://web.archive.org/web/20080111154608/http://www.npi.gov.au/database/substance-info/profiles/50.html National Pollutant Inventory - Lead and Lead Compounds Fact Sheet]
{{Lead compounds}}
{{Hydroxides}}