Lead(II) hydroxide

Lead(II) hydroxide, Pb(OH)2, is a hydroxide of lead, with lead in oxidation state +2. In 1964 it was believed that such a simple compound did not exist, as lead basic carbonate (2PbCO3·Pb(OH)2) or lead(II) oxide (PbO) was encountered where lead hydroxide was expected.[3] 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. [4]

Lead(II) hydroxide
Names
IUPAC name
Lead(II) hydroxide
Other names
lead hydroxide
plumbous hydroxide
Plumbous acid
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.039.358
EC Number
  • 243-310-3
  • InChI=1S/2H2O.Pb/h2*1H2;/q;;+2/p-2 checkY
    Key: VNZYIVBHUDKWEO-UHFFFAOYSA-L checkY
  • InChI=1/2H2O.Pb/h2*1H2;/q;;+2/p-2
    Key: VNZYIVBHUDKWEO-NUQVWONBAE
  • [OH-].[OH-].[Pb+2]
Properties
Pb(OH)2
Molar mass 241.21 g/mol
Appearance white amorphous powder
Density 7.41 g/cm3 [1]
Melting point 135 °C (275 °F; 408 K) (decomposes)
0.0155 g/100 mL (20 °C)[2]
1.42 x 10−20
Solubility soluble in dilute acid and alkalis;
readily soluble in acetone , nitric acid and acetic acid
Hazards
GHS labelling:
GHS06: ToxicGHS07: Exclamation markGHS09: Environmental hazard
Danger
H302, H332, H351, H360, H373, H410
NFPA 704 (fire diamond)
2
0
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
Infobox references

Preparation

When a hydroxide is added to a solution of a lead(II) salt, 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] 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 Mo6S8 subunit of the Chevrel phases.[6]

Reactions

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]

Lead hydrate

The name Lead hydrate has sometimes been used in the past but it is unclear whether this refers to Pb(OH)2 or PbO·xH2O.[7][8]

References
  1. Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  2. Handbook of Chemistry and Physics, 1st edition, 2000, CRC Press ISBN 0-8493-0740-6
  3. G. Todd and E. Parry (1964). "Character of Lead Hydroxide and Basic Lead Carbonate". Nature. 202 (4930): 386–387. Bibcode:1964Natur.202..386T. doi:10.1038/202386a0. S2CID 44941178.
  4. W. Nimal Perera, Glenn Hefter, and Pal M. Sipos (2001). "An Investigation of the Lead(II)−Hydroxide System". Inorganic Chemistry. 40 (16): 3974–3978. doi:10.1021/ic001415o. PMID 11466056.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. Von Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman, "Inorganic Chemistry", Academic Press, 2001 (Google books).
  6. R. A. Howie; W. Moser (1968). "Structure of Tin(II) "Hydroxide" and Lead(II) "Hydroxide". Nature. 219 (5152): 372–373. Bibcode:1968Natur.219..372H. doi:10.1038/219372a0. S2CID 45007541.
  7. "Process of treating lead hydrate produced by electrolysis".
  8. "Process of manufacturing white lead".
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