Mercury sulfide
| Mercury sulfide | ||
|---|---|---|
 | ||
 | ||
| IUPAC name Mercury sulfide | ||
| Identifiers | ||
| CAS number | 1344-48-5  | |
| PubChem | 62402 | |
| Properties | ||
| Molecular formula | HgS | |
| Molar mass | 232.66 g/mol | |
| Density | 8.10 g/cm3 | |
| Melting point | 580 °C decomp. | |
| Solubility in water | insoluble | |
| Band gap | 2.1 eV (direct, α-HgS) [1] | |
| Refractive index (nD) | w=2.905, e=3.256, bire=0.3510 (α-HgS) [2] | |
| Thermochemistry | ||
| Std enthalpy of formation ΔfH |
−58 kJ·mol−1[3] | |
| Standard molar entropy S |
78 J·mol−1·K−1[3] | |
| Hazards | ||
| MSDS | ICSC 0981 | |
| EU Index | 080-002-00-6 | |
| EU classification | Very toxic (T+) Dangerous for the environment (N) | |
| R-phrases | R26/27/28, R33, R50/53 | |
| S-phrases | (S1/2), S13, S28, S45, S60, S61 | |
| Flash point | Non-flammable | |
| Related compounds | ||
| Other anions | Mercury oxide Mercury selenide Mercury telluride | |
| Other cations | Zinc sulfide Cadmium sulfide | |
(verify) (what is: / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | ||
| Infobox references | ||
Mercury sulfide, mercuric sulfide, mercury sulphide, or mercury(II) sulfide is a chemical compound composed of the chemical elements mercury and sulfur. It is represented by the chemical formula HgS. It is virtually insoluble in water.[4]
Crystal structure
HgS is dimorphic with two crystal forms:
- red cinnabar (α-HgS, hexagonal, hP6, P3221), is the form in which mercury is most commonly found in nature.
- black, metacinnabar (β-HgS), is less common in nature and adopts the zinc blende (T2d-F43m) crystal structure.
Crystals of red, α-HgS, are optically active. This is caused by the Hg-S helices in the structure.[5]
Preparation and chemistry
β-HgS is precipitated as a black powder when H2S is bubbled through solutions of Hg(II) salts.[6] β-HgS is unreactive to all but concentrated acids.[4]
Mercury metal is produced from the cinnabar ore by roasting in air and condensing the vapour.[4]
Uses
α-HgS is used as a red pigment when it is known as vermilion. Vermilion is known to darken and this has been ascribed to conversion from red α-HgS to black β-HgS. Investigations at Pompeii where red walls when originally excavated have darkened has been ascribed to the formation of Hg-Cl compounds (e.g., corderoite, calomel, and terlinguaite) and calcium sulfate, gypsum, rather than β-HgS, which was not detected.[7]
See also
References
- ↑ L. I. Berger, Semiconductor Materials (1997) CRC Press ISBN 0-8493-8912-7
- ↑ Webminerals
- ↑ 3.0 3.1 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A22. ISBN 0-618-94690-X.
- ↑ 4.0 4.1 4.2 Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. p. 1406. ISBN 0-08-022057-6.
- ↑ Glazer, A. M.; Stadnicka K. (1986). "On the origin of optical activity in crystal structures". J. Appl. Cryst. 19 (2): 108–122. doi:10.1107/S0021889886089823.
- ↑ Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999), Advanced Inorganic Chemistry (6th ed.), New York: Wiley-Interscience, ISBN 0-471-19957-5
- ↑ Cotte, M; Susini J, Metrich N, Moscato A, Gratziu C, Bertagnini A, Pagano M (2006). "Blackening of Pompeian Cinnabar Paintings: X-ray Microspectroscopy Analysis". Anal. Chem. 78 (21): 7484–7492. doi:10.1021/ac0612224. PMID 17073416.
External links
- National Pollutant Inventory - Mercury and compounds Fact Sheet - link leads to "page not found"
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