Lead(II) chloride (PbCl2) is an inorganic compound which is a white solid under ambient conditions. It is poorly soluble in water. Lead(II) chloride is one of the most important lead-based reagents. It also occurs naturally in the form of the mineral cotunnite.
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||278.10 g/mol|
|Appearance||white odorless solid|
|Melting point||501 °C (934 °F; 774 K)|
|Boiling point||950 °C (1,740 °F; 1,220 K)|
|0.99 g/100 mL (20 °C)|
Solubility product (Ksp)
|1.7×10−5 (20 °C)|
|Solubility||slightly soluble in dilute HCl, ammonia; |
insoluble in alcohol
Soluble in concerntrated HCl (>6M)
Refractive index (nD)
|Pnma, No. 62|
|135.98 J K−1 mol−1|
Std enthalpy of
|H302, H332, H351, H360, H372, H410|
|P201, P261, P273, P304+P340, P308+P313, P312, P391|
|NFPA 704 (fire diamond)|
|Lethal dose or concentration (LD, LC):|
LDLo (lowest published)
|140 mg/kg (guinea pig, oral)|
|Supplementary data page|
|Lead(II) chloride (data page)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
(what is ?)
In solid PbCl2, each lead ion is coordinated by nine chloride ions in a tricapped triangular prism formation — six lie at the vertices of a triangular prism and three lie beyond the centers of each rectangular prism face. The 9 chloride ions are not equidistant from the central lead atom, 7 lie at 280–309 pm and 2 at 370 pm. PbCl2 forms white orthorhombic needles.
Coordination geometry of Pb2+
Coordination geometry of Cl−
Coordination polyhedron of Pb2+
In the gas phase, PbCl2 molecules have a bent structure with the Cl–Pb–Cl angle being 98° and each Pb–-Cl bond distance being 2.44 Å. Such PbCl2 is emitted from internal combustion engines that use ethylene chloride-tetraethyllead additives for antiknock purposes.
PbCl2 is sparingly soluble in water, solubility product Ksp = 1.7×10−5 at 20 °C. It is one of only 5 commonly water-insoluble chlorides, the other 4 being thallium(I) chloride, silver chloride (AgCl) with Ksp = 1.8×10−10, copper(I) chloride (CuCl) with Ksp = 1.72×10−7 and mercury(I) chloride (Hg2Cl2) with Ksp = 1.3×10−18.
PbCl2 occurs naturally in the form of the mineral cotunnite. It is colorless, white, yellow, or green with a density of 5.3–5.8 g/cm3. The hardness on the Mohs scale is 1.5–2. The crystal structure is orthorhombic dipyramidal and the point group is 2/m 2/m 2/m. Each Pb has a coordination number of 9. Cotunnite occurs near volcanoes: Vesuvius, Italy; Tarapacá, Chile; and Tolbachik, Russia.
PbCl2 can be formed by the reduction of copper(II) chloride by lead metal:
PbCl2 also forms by the action of chlorine gas on lead metal:
Addition of chloride ions to a suspension of PbCl2 gives rise to soluble complex ions. In these reactions the additional chloride (or other ligands) break up the chloride bridges that comprise the polymeric framework of solid PbCl2(s).
PbCl2 is used in synthesis of lead(IV) chloride (PbCl4): Cl2 is bubbled through a saturated solution of PbCl2 in aqueous NH4Cl forming [NH4]2[PbCl6]. The latter is reacted with cold concentrated sulfuric acid (H2SO4) forming PbCl4 as an oil.
Lead(II) chloride is the main precursor for organometallic derivatives of lead, such as plumbocenes. The usual alkylating agents are employed, including Grignard reagents and organolithium compounds:
These reactions produce derivatives that are more similar to organosilicon compounds, i.e. that Pb(II) tends to disproportionate upon alkylation.
PbCl2 can be used to produce PbO2 by treating it with sodium hypochlorite (NaClO), forming a reddish-brown precipitate of PbO2.
Like other soluble lead compounds, exposure to PbCl2 may cause lead poisoning.
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