Lead iodide

Lead(II) iodide

Names
Other names Plumbous iodide
Identifiers
CAS Number	10101-63-0 Y
3D model (Jmol)	Interactive image
ChemSpider	23305 Y
ECHA InfoCard	100.030.220
PubChem	24931
UNII	OTL90F2GLT Y
InChI InChI=1S/2HI.Pb/h2*1H;/q;;+2/p-2 Y Key: RQQRAHKHDFPBMC-UHFFFAOYSA-L Y InChI=1/2HI.Pb/h2*1H;/q;;+2/p-2 Key: RQQRAHKHDFPBMC-NUQVWONBAP
SMILES I[Pb]I
Properties
Chemical formula	PbI 2
Molar mass	461.01 g/mol
Appearance	bright yellow powder
Odor	odorless
Density	6.16 g/cm3
Melting point	402 °C (756 °F; 675 K)
Boiling point	953 °C (1,747 °F; 1,226 K)
Solubility in water	0.044 g/100 mL (0 °C) 0.0756 g/100 mL (20 °C) 0.41 g/100 mL (100 °C)
Solubility product (Ksp)	4.41 x 10−9 (20 °C)
Solubility	insoluble in ethanol, cold HCl soluble in alkalis, KI solution, methyl isopropyl ketone
Band gap	2.3 eV
Magnetic susceptibility (χ)	−126.5·10−6 cm3/mol
Structure
Crystal structure	Rhombohedral, hexagonal hP3
Space group	P-3m1, No. 164
Coordination geometry	octahedral
Hazards
EU classification (DSD)	Repr. Cat. 1/3 Harmful (Xn) Dangerous for the environment (N)
R-phrases	R61, R20/22, R33, R62, R50/53
S-phrases	S53, S45, S60, S61
NFPA 704	0 3 0
Flash point	Non-flammable
Related compounds
Other anions	Lead(II) fluoride Lead(II) chloride Lead(II) bromide
Other cations	Tin(II) iodide
Related compounds	Thallium(I) iodide Bismuth(III) iodide
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) iodide or lead iodide is a salt (chemistry) with the formula PbI
2. At room temperature, it is a bright yellow odorless crystalline solid, that becomes orange and red when heated. It was formerly called plumbous iodide.

The compound currently has a few specialized applications, such as the manufacture solar cells and X-ray and gamma-ray detectors. Its prepraration is a popular demonstration in basic chemistry education, to teach topics such as double displacement reactions and stoichometry. It is decomposed by light at moderately high temperatures and this effect has been used in a patented photographic process.

Lead iodide was formerly employed as a yellow pigment in some paints, with the name iodide yellow. However, that use has been largely discontinued due to its toxicity and poor stability.

PbI
2 is commonly synthesized via a double displacement reaction between potassium iodide KI and lead(II) nitrate Pb(NO
3)₂ in water solution:

While the potassium nitrate KNO
3 is soluble, the lead iodide PbI
2 is nearly insoluble at room temperature, and thus precipitates out.