Lead(II) hydroxide is an inorganic compound with the formula . 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. Instead it forms oxides and oxy-hydroxides.
]
Preparation
Addition of hydroxide to a solution of a lead(II) salt, a hydrated lead oxide (with ''x'' < 1) is obtained. Careful hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...
of lead(II) acetate solution yields a crystalline product with a formula or .[Von Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman, "Inorganic Chemistry", Academic Press, 200]
(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 subunit of the Chevrel phases.
Reactions
In aqueous solution
An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, also known as sodium chloride (NaCl), in water ...
, lead(II) hydroxide is a somewhat weak base, forming lead(II) ion
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...
, , under weakly acidic
An acid is a molecule or ion capable of either donating a proton (i.e. hydrogen cation, H+), known as a Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid.
The first category of acids are the ...
conditions. This cation
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...
hydrolyzes and, under progressively increasing alkaline
In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The ...
conditions, it becomes somewhat weak acid
An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...
, and it forms , (aqueous), , and other species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
, including several polynuclear species, e.g., , , .
History
The name lead hydrate has sometimes been used in the past but it is unclear whether this refers to or . In 1964 it was believed that such a simple compound did not exist, as lead basic carbonate () or lead(II) oxide
Lead(II) oxide, also called lead monoxide, is the inorganic compound with the molecular formula Pb O. It occurs in two polymorphs: litharge having a tetragonal crystal structure, and massicot having an orthorhombic crystal structure. Modern ...
(PbO) was encountered where lead hydroxide was expected.
References
External links
Case Studies in Environmental Medicine - Lead Toxicity
ToxFAQs: Lead
{{Hydroxides
Hydroxides
Lead(II) compounds