Mercury sulfide
| Mercury sulfide | |
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Mercury sulfide |
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Other names
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| Identifiers | |
| CAS number | 1344-48-5  |
| 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, 100 kPa) |
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| 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]
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[edit] 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-F-43m) crystal structure.
Crystals of red, α-HgS, are optically active. This is caused by the Hg-S helices in the structure.[5]
[edit] 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]
[edit] 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]
[edit] See also
[edit] References
- ^ L. I. Berger, Semiconductor Materials (1997) CRC Press ISBN 0849389127
- ^ Webminerals
- ^ a b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed.. Houghton Mifflin Company. p. A22. ISBN 061894690X.
- ^ a b c Greenwood, Norman N.; Earnshaw, A. (1984). Chemistry of the Elements. Oxford: Pergamon. 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.
[edit] External links
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