Lead(II) chloride

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Lead(II) chloride
PbCl2precipiate.jpg
Cotunnite structure.png
Names
IUPAC names
Lead(II) chloride
Lead dichloride
Other names
Plumbous chloride
Cotunnite
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.028.950 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 231-845-5
PubChem CID
UNII
  • InChI=1S/2ClH.Pb/h2*1H;/q;;+2/p-2 Yes check.svgY
    Key: HWSZZLVAJGOAAY-UHFFFAOYSA-L Yes check.svgY
  • Cl[Pb]Cl
Properties
PbCl2
Molar mass 278.10 g/mol
Appearancewhite odorless solid
Density 5.85 g/cm3
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) [1]
1.7×10−5 (20 °C)
Solubility slightly soluble in dilute HCl, ammonia;
insoluble in alcohol

Soluble in hot water as well as in presence of alkali hydroxide

Contents

Soluble in concerntrated HCl (>6M)

73.8·10−6 cm3/mol
2.199 [2]
Structure
Orthorhombic, oP12
Pnma, No. 62
Thermochemistry
135.98 JK−1mol−1
-359.41 kJ/mol
Hazards [3]
GHS labelling:
GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Danger
H302, H332, H351, H360, H372, H410
P201, P261, P273, P304+P340, P308+P313, P312, P391
NFPA 704 (fire diamond)
3
0
0
Lethal dose or concentration (LD, LC):
140 mg/kg (guinea pig, oral) [4]
Related compounds
Other anions
Lead(II) fluoride
Lead(II) bromide
Lead(II) iodide
Other cations
Lead(IV) chloride
Tin(II) chloride
Germanium(II) chloride
Related compounds
Thallium(I) chloride
Bismuth chloride
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).
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Infobox references

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.

Structure and properties

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. [5] PbCl2 forms white orthorhombic needles.

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. [6] 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. [7] [8]

Occurrence

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. [9]

Synthesis

Double displacement/Metathesis

Lead(II) chloride precipitates upon addition of aqueous chloride sources (HCl, NaCl, KCl) to lead(II) compounds

Direct Reduction

PbCl2 can be formed by the reduction of copper(II) chloride by lead metal:

Direct chlorination

PbCl2 also forms by the action of chlorine gas on lead metal:

Pb + Cl2 → PbCl2

Reactions

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(s) + Cl → [PbCl3](aq)
PbCl2(s) + 2 Cl → [PbCl4]2−(aq)

PbCl2 reacts with molten NaNO2 to give PbO:

PbCl2(l) + 3 NaNO2 → PbO + NaNO3 + 2 NO + 2 NaCl

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. [11]

Lead(II) chloride is the main precursor for organometallic derivatives of lead, such as plumbocenes. [12] The usual alkylating agents are employed, including Grignard reagents and organolithium compounds:

2 PbCl2 + 4 RLi → R4Pb + 4 LiCl + Pb
2 PbCl2 + 4 RMgBr → R4Pb + Pb + 4 MgBrCl
3 PbCl2 + 6 RMgBr → R3Pb-PbR3 + Pb + 6 MgBrCl [13]

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.

Uses

Toxicity

Like other soluble lead compounds, exposure to PbCl2 may cause lead poisoning.

Related Research Articles

Acid–base reaction Chemical reaction

An acid–base reaction is a chemical reaction that occurs between an acid and a base. It can be used to determine pH. Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example, Brønsted–Lowry acid–base theory.

Hydroxide Chemical compound

Hydroxide is a diatomic anion with chemical formula OH. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salts, some of which dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemical. The corresponding electrically neutral compound HO is the hydroxyl radical. The corresponding covalently bound group –OH of atoms is the hydroxy group. Hydroxide ion and hydroxy group are nucleophiles and can act as catalysts in organic chemistry.

In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions.

Solubility equilibrium is a type of dynamic equilibrium that exists when a chemical compound in the solid state is in chemical equilibrium with a solution of that compound. The solid may dissolve unchanged, with dissociation, or with chemical reaction with another constituent of the solution, such as acid or alkali. Each solubility equilibrium is characterized by a temperature-dependent solubility product which functions like an equilibrium constant. Solubility equilibria are important in pharmaceutical, environmental and many other scenarios.

Ammonium Polyatomic ion

The ammonium cation is a positively charged polyatomic ion with the chemical formula NH+
4
. It is formed by the protonation of ammonia. Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations, where one or more hydrogen atoms are replaced by organic groups.

In chemistry, an amphoteric compound is a molecule or ion that can react both as an acid and as a base. What exactly this can mean depends on which definitions of acids and bases are being used. The prefix of the word 'amphoteric' is derived from a Greek prefix amphi which means "both".

Iron(III) chloride Inorganic compound

Iron(III) chloride is the inorganic compound with the formula. Also called ferric chloride, it is a common compound of iron in the +3 oxidation state. The anhydrous compound is a crystalline solid with a melting point of 307.6 °C. The color depends on the viewing angle: by reflected light the crystals appear dark green, but by transmitted light they appear purple-red.

Zinc chloride Chemical compound

Zinc chloride is the name of chemical compounds with the formula ZnCl2 and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white, and are highly soluble in water. This white salt is hygroscopic and even deliquescent. Samples should therefore be protected from sources of moisture, including the water vapor present in ambient air. Zinc chloride finds wide application in textile processing, metallurgical fluxes, and chemical synthesis. No mineral with this chemical composition is known aside from the very rare mineral simonkolleite, Zn5(OH)8Cl2·H2O.

Barium chloride Chemical compound

Barium chloride is an inorganic compound with the formula BaCl2. It is one of the most common water-soluble salts of barium. Like most other water-soluble barium salts, it is white, highly toxic, and imparts a yellow-green coloration to a flame. It is also hygroscopic, converting first to the dihydrate BaCl2(H2O)2. It has limited use in the laboratory and industry.

Silver chloride Chemical compound with the formula AgCl

Silver chloride is a chemical compound with the chemical formula AgCl. This white crystalline solid is well known for its low solubility in water (this behavior being reminiscent of the chlorides of Tl+ and Pb2+). Upon illumination or heating, silver chloride converts to silver (and chlorine), which is signaled by grey to black or purplish coloration to some samples. AgCl occurs naturally as a mineral chlorargyrite.

Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds. It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms may need to be brought to this state before using standard methods. The solution is then treated with various reagents to test for reactions characteristic of certain ions, which may cause color change, precipitation and other visible changes.

Cobalt(II) chloride Chemical compound

Cobalt(II) chloride is an inorganic compound of cobalt and chlorine, with the formula CoCl
2
. The compound forms several hydrates CoCl
2
nH
2
O
, for n = 1, 2, 6, and 9. Claims of the formation of tri- and tetrahydrates have not been confirmed. The anhydrous form is a blue crystalline solid; the dihydrate is purple and the hexahydrate is pink. Commercial samples are usually the hexahydrate, which is one of the most commonly used cobalt compounds in the lab.

Nickel(II) chloride Chemical compound

Nickel(II) chloride (or just nickel chloride) is the chemical compound NiCl2. The anhydrous salt is yellow, but the more familiar hydrate NiCl2·6H2O is green. Nickel(II) chloride, in various forms, is the most important source of nickel for chemical synthesis. The nickel chlorides are deliquescent, absorbing moisture from the air to form a solution. Nickel salts have been shown to be carcinogenic to the lungs and nasal passages in cases of long-term inhalation exposure.

Tin(II) chloride Chemical compound

Tin(II) chloride, also known as stannous chloride, is a white crystalline solid with the formula SnCl2. It forms a stable dihydrate, but aqueous solutions tend to undergo hydrolysis, particularly if hot. SnCl2 is widely used as a reducing agent (in acid solution), and in electrolytic baths for tin-plating. Tin(II) chloride should not be confused with the other chloride of tin; tin(IV) chloride or stannic chloride (SnCl4).

Organolead compound

Organolead compounds are chemical compounds containing a chemical bond between carbon and lead. Organolead chemistry is the corresponding science. The first organolead compound was hexaethyldilead (Pb2(C2H5)6), first synthesized in 1858. Sharing the same group with carbon, lead is tetravalent.

Bismuth chloride Chemical compound

Bismuth chloride (or butter of bismuth) is an inorganic compound with the chemical formula BiCl3. It is a covalent compound and is the common source of the Bi3+ ion. In the gas phase and in the crystal, the species adopts a pyramidal structure, in accord with VSEPR theory.

Lead(II) bromide Chemical compound

Lead(II) bromide is the inorganic compound with the formula PbBr2. It is a white powder. It is produced in the burning of typical leaded gasolines.

Germanium dichloride is a chemical compound of germanium and chlorine with the formula GeCl2. It is a solid and contains germanium in the +2 oxidation state.

Compounds of lead exist with lead in two main oxidation states: +2 and +4. The former is more common. Inorganic lead(IV) compounds are typically strong oxidants or exist only in highly acidic solutions.

References

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  3. "Classifications - CL Inventory". echa.europa.eu.
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  6. Hargittai, I; Tremmel, J; Vajda, E; Ishchenko, A; Ivanov, A; Ivashkevich, L; Spiridonov, V (1977). "Two independent gas electron diffraction investigations of the structure of plumbous chloride". Journal of Molecular Structure. 42: 147–151. Bibcode:1977JMoSt..42..147H. doi:10.1016/0022-2860(77)87038-5.
  7. CRC Handbook of Chemistry and Physics, 79th Edition, David R. Lide (Ed), p. 8-108
  8. Brown, Lemay, Burnsten. Chemistry The Central Science. "Solubility-Product Constants for Compounds at 25 °C". (ed 6, 1994). p. 1017
  9. Cotunnite
  10. 1 2 Dictionary of Inorganic and Organometallic Compounds. Lead(II) Chloride. http://www.chemnetbase.com]
  11. Housecroft, C. E.; Sharpe, A. G. (2004). Inorganic Chemistry (2nd ed.). Prentice Hall. p. 365. ISBN   978-0-13-039913-7.
  12. Lowack, R (1994). "Decasubstituted decaphenylmetallocenes". J. Organomet. Chem. 476: 25–32. doi:10.1016/0022-328X(94)84136-5.
  13. Housecroft, C. E.; Sharpe, A. G. (2004). Inorganic Chemistry (2nd ed.). Prentice Hall. p. 524. ISBN   978-0-13-039913-7.
  14. Aboujalil, Almaz; Deloume, Jean-Pierre; Chassagneux, Fernand; Scharff, Jean-Pierre; Durand, Bernard (1998). "Molten salt synthesis of the lead titanate PbTiO3, investigation of the reactivity of various titanium and lead salts with molten alkali-metal nitrites". Journal of Materials Chemistry. 8 (7): 1601. doi:10.1039/a800003d.
  15. Stained Glass Terms and Definitions. aurene glass
  16. Kirk-Othmer. Encyclopedia of Chemical Technology. (ed 4). p 913
  17. Perry & Phillips. Handbook of Inorganic Compounds. (1995). p 213
  18. Kirk-Othmer. Encyclopedia of Chemical Technology. (ed 4). p. 241