Copper(I) sulfide

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Copper(I) sulfide
Kristallstruktur Chalkosin.png
Names
IUPAC name
Copper(I) sulfide
Other names
Cuprous sulfide
Chalcocite
Copper glance
Identifiers
  • 22205-45-4 checkY
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.040.751 Edit this at Wikidata
RTECS number
  • GL8910000
UNII
  • InChI=1S/2Cu.S/q2*+1;-2 checkY
    Key: AQMRBJNRFUQADD-UHFFFAOYSA-N checkY
  • InChI=1/2Cu.S/q2*+1;-2
    Key: AQMRBJNRFUQADD-UHFFFAOYAN
  • [Cu+].[Cu+].[S-2]
Properties
Cu2S
Molar mass 159.16 g/mol
Density 5.6 g/cm3 [1]
Melting point 1,130 °C (2,070 °F; 1,400 K)[2]
Insoluble
Solubility slightly soluble in HCl; soluble in NH4OH; dissolves in KCN; decomposes in HNO3, H2SO4
Hazards
Flash point Non-flammable
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 1 mg/m3 (as Cu)[3]
REL (Recommended)
 TWA 1 mg/m3 (as Cu)[3]
IDLH (Immediate danger)
 TWA 100 mg/m3 (as Cu)[3]
Related compounds
Other anions
 Copper(I) oxide
Other cations
 Nickel(II) sulfide
Copper(II) sulfide
Zinc sulfide
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

Copper(I) sulfide is a copper sulfide, a chemical compound of copper and sulfur. It has the chemical compound Cu2S. It is found in nature as the mineral chalcocite. It has a narrow range of stoichiometry ranging from Cu1.997S to Cu2.000S.[4]

Preparation and reactions[]

Cu2S can be prepared by heating copper strongly in sulfur vapour or H2S.[2] The reaction of copper powder in molten sulfur rapidly produces Cu2S, whereas pellets of copper require much higher temperature.[5] Cu2S reacts with oxygen to form SO2:[6]

2 Cu2S + 3 O2 → 2 Cu2O + 2 SO2

In the production of copper two thirds of the molten copper sulfide is oxidised as above, and the Cu2O reacts with unoxidised Cu2S to give Cu metal:[6]

Cu2S + 2 Cu2O → 6 Cu + SO2

Structure[]

There are two forms of Cu2S: a low temperature monoclinic form ("low-chalcocite") which has a complex structure with 96 copper atoms in the unit cell[7] and a hexagonal form stable above 104 °C.[8] In this structure there are 24 crystallographically distinct Cu atoms and the structure has been described as approximating to a hexagonal close packed array of sulfur atoms with Cu atoms in planar 3 coordination. This structure was initially assigned an orthorhombic cell due to the twinning of the sample crystal.

There is also a crystallographically-distinct phase (the mineral djurleite) with stoichiometry Cu1.96S which is non-stoichiometric (range Cu1.934S-Cu1.965S) and has a monoclinic structure with 248 copper and 128 sulfur atoms in the unit cell.[7] Cu2S and Cu1.96S are similar in appearance and hard to distinguish one from another.[9]

See also[]

References[]

  1. ^ Patnaik, Pradyot (2002). Handbook of Inorganic Chemicals. McGraw-Hill, ISBN 0-07-049439-8
  2. ^ a b Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. p. 1373. ISBN 978-0-08-022057-4.
  3. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).
  4. ^ Potter, R. W. (1977). "An electrochemical investigation of the system copper-sulfur". Economic Geology. 72 (8): 1524–1542. doi:10.2113/gsecongeo.72.8.1524.
  5. ^ Blachnik R., Müller A. (2000). "The formation of Cu2S from the elements I. Copper used in form of powders". Thermochimica Acta. 361: 31. doi:10.1016/S0040-6031(00)00545-1.
  6. ^ a b Wiberg, Egon and Holleman, Arnold Frederick (2001) Inorganic Chemistry, Elsevier ISBN 0-12-352651-5
  7. ^ a b Evans, H. T. (1979). "Djurleite (Cu1.94S) and Low Chalcocite (Cu2S): New Crystal Structure Studies". Science. 203 (4378): 356–8. doi:10.1126/science.203.4378.356. PMID 17772445.
  8. ^ Wells A.F. (1984) Structural Inorganic Chemistry, 5th ed., Oxford Science Publications, ISBN 0-19-855370-6
  9. ^ Evans H.T. (1981). "Copper coordination in low chalcocite and djurleite and other copper-rich sulfides" (PDF). American Mineralogist. 66 (7–8): 807–818.
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