Lead(II) hydroxide

Lead(II) hydroxide

Names
IUPAC name Lead(II) hydroxide
Other names lead hydroxide plumbous hydroxide
Identifiers
CAS Number	[1] 1319-46-6 N
3D model (JSmol)	Interactive image
ChemSpider	8035300 Y
ECHA InfoCard	100.039.358
PubChem CID	9859601
InChI InChI=1S/2H2O.Pb/h2*1H2;/q;;+2/p-2 Y Key: VNZYIVBHUDKWEO-UHFFFAOYSA-L Y InChI=1/2H2O.Pb/h2*1H2;/q;;+2/p-2 Key: VNZYIVBHUDKWEO-NUQVWONBAE
SMILES [OH-].[OH-].[Pb+2]
Properties
Chemical formula	Pb(OH)2
Molar mass	241.21 g/mol
Appearance	white amorphous powder
Density	7.41 g/cm3
Melting point	135 °C (275 °F; 408 K) (decomposes)
Solubility in water	0.0155 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EU classification (DSD) (outdated)	T
R-phrases (outdated)	R25
S-phrases (outdated)	(S1/2) S20/21 S29/56 S45
NFPA 704	0 2 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

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.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 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. 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.

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⁺.

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.