Mercury(I) iodide

Mercury(I) iodide
Names
	IUPAC name Dimercury diiodide
	Other names Mercury(I) iodide; Mercurous iodide; Red mercury
Identifiers
CAS Number	15385-57-6 ;
3D model (JSmol)	Interactive image;
ChemSpider	21160367 ;
ECHA InfoCard	100.035.811
EC Number	239-409-6;
PubChem CID	27243;
UNII	HT0935F2JR ;
UN number	1638
CompTox Dashboard (EPA)	DTXSID701314265 ;
	InChI InChI=1S/2Hg.2HI/h;;21H/q2+1;;/p-2 Key: NDKKKEPYKOOXLG-UHFFFAOYSA-L;
	SMILES I[Hg][Hg]I;
Properties
Chemical formula	Hg; 2I; 2
Molar mass	654.99 g mol−1
Appearance	Dark yellow, opaque crystals
Odor	Odourless
Density	7.7 g mL−1
Solubility product (Ksp)	5.2×10−29
Magnetic susceptibility (χ)	−41.5·10−6 cm3/mol
Thermochemistry
Std molar; entropy (S⦵298)	241.47 J K−1 mol−1
Std enthalpy of; formation (ΔfH⦵298)	−119.09 kJ mol−1
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H310, H330, H373, H410
Precautionary statements	P260, P273, P280, P284, P301+P310
Related compounds
Other anions	Mercury(I) bromide; Mercury(I) chloride; Mercury(I) fluoride
Related compounds	Mercury(II) iodide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Mercury(I) iodide is a chemical compound of mercury and iodine. The chemical formula is Hg₂I₂. It is photosensitive and decomposes easily to mercury and HgI₂.