Lead(II) hydroxide
| Lead(II) hydroxide | |
|---|---|
 | |
| IUPAC name Lead(II) hydroxide | |
| Other names lead hydroxide | |
| Identifiers | |
| CAS number | [1] 1319-46-6[2]  |
| ChemSpider | 8035300  |
| Jmol-3D images | {{#if:[OH-].[OH-].[Pb+2]|Image 1 |
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| Properties | |
| Molecular formula | Pb(OH)2 |
| Molar mass | 241.21 g/mol |
| Appearance | white amorphous powder |
| Density | 7.41 g/cm3 [3] |
| Melting point | 135 °C (decomp) |
| Solubility in water | 1.55 g/100 mL (20 °C) |
| Solubility product, Ksp | 1.42 x 10-20 |
| Solubility | soluble in dilute acid and alkalis; insoluble in acetone and acetic acid |
| Hazards | |
| EU classification | Toxic (T) |
| R-phrases | R25 |
| S-phrases | (S1/2) S20/21 S29/56 S45 |
| NFPA 704 |
 0
2
0
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| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| Infobox references | |
Lead(II) hydroxide, Pb(OH)2, is a hydroxide of lead, with lead in oxidation state +2. Although it appears a fundamentally simple compound, it is doubtful if lead hydroxide is stable as a solid phase.[4] Lead basic carbonate (PbCO3·2Pb(OH)2) or lead(II) oxide (PbO) is encountered in practice where lead hydroxide is expected. This has been a subject of considerable confusion in the past.
When an alkali hydroxide is added to a solution of a lead(II) salt, then a hydrated lead oxide PbO·xH2O (with x < 1) is obtained. Careful hydrolysis of lead(II) acetate solution yields a crystalline product with a formula 6PbO·2H2O = Pb6O4(OH)4.[5]
In solution, lead(II) hydroxide is a somewhat weak base, forming lead(II) ion, Pb2+, under weakly acidic conditions. This cation hydrolyzes and, under progressively increasing alkaline conditions, forms Pb(OH)+, Pb(OH)2(aqueous), Pb(OH)3−, and other species, including several polynuclear species, e.g., Pb4(OH)44+, Pb3(OH)42+, Pb6O(OH)64+.[5]
References
- ↑ http://www.commonchemistry.org/ChemicalDetail.aspx?ref=1319-46-6&terms=lead(II)+hydroxide
- ↑ http://www.commonchemistry.org/ChemicalDetail.aspx?ref=1319-46-6&terms=lead(II)+hydroxide
- ↑ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
- ↑ G. Todd and E. Parry (1964). "Character of Lead Hydroxide and Basic Lead Carbonate". Nature 202 (4930): 386–387. doi:10.1038/202386a0.
- ↑ 5.0 5.1 Von Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman, "Inorganic Chemistry", Academic Press, 2001 (Google books).
External links
- Case Studies in Environmental Medicine - Lead Toxicity
- ToxFAQs: Lead
- National Pollutant Inventory - Lead and Lead Compounds Fact Sheet
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