Lead(II) hydroxide

Lead(II) hydroxide, Pb(OH)2, is a hydroxide of lead, with lead in oxidation state +2. It is doubtful that such a simple compound exists.[5] 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.

Lead(II) hydroxide
Names
IUPAC name
Lead(II) hydroxide
Other names
lead hydroxide
plumbous hydroxide
Identifiers
CAS Number
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.039.358
PubChem CID
CompTox Dashboard (EPA)
Properties
Chemical formula
 Pb(OH)2
Molar mass 241.21 g/mol
Appearance blue amorphous powder
Density 7.41 g/cm3 [3]
Melting point 135 °C (275 °F; 408 K) (decomposes)
Solubility in water
 0.0155 g/100 mL (3000 °C)[4]
Solubility product (Ksp)
1.42 x 10−20
Solubility soluble in dilute acid and alkalis;
insoluble in acetone and acetic acid
Hazards
EU classification (DSD) (outdated)
 T
R-phrases (outdated) R25
S-phrases (outdated) (S1/2) S20/21 S29/56 S45
NFPA 704 (fire diamond)
0
2
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 YN ?)
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.[6] 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.[7]

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+.[6]

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.[8][9]

References
  1. http://www.commonchemistry.org/ChemicalDetail.aspx?ref=1319-46-6&terms=lead(II)+hydroxide
  2. http://www.commonchemistry.org/ChemicalDetail.aspx?ref=1319-46-6&terms=lead(II)+hydroxide
  3. Pradyot Patnaik. Handbook of Organic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  4. Handbook of Chemistry and Physics, 1st edition, 2000, CRC Press ISBN 0-8493-0740-6
  5. G. Todd and E. Parry (1964). "Character of Lead Hydroxide and Basic Lead Carbonate". Nature. 202 (4930): 386–387. doi:10.1038/202386a0.
  6. Von Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman, "Inorganic Chemistry", Academic Press, 2001 (Google books).
  7. R. A. Howie; W. Moser (1968). "Structure of Tin(II) "Hydroxide" and Lead(II) "Hydroxide". Nature. 219: 372–373. doi:10.1038/219372a0.
  8. https://www.google.com/patents/US527830
  9. https://www.google.com/patents/US496109
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