Silver sulfide

Silver sulfide
Ball-and-stick model of silver sulfide
Sample of silver sulfide
Names
IUPAC name
Silver(I) sulfide
Other names
Silver sulfide
Argentous sulfide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.040.384 Edit this at Wikidata
EC Number
  • 244-438-2
UNII
  • InChI=1S/2Ag.S/q2*+1;-2 ☒N
    Key: XUARKZBEFFVFRG-UHFFFAOYSA-N ☒N
  • S(Ag)Ag
Properties
Ag2S
Molar mass 247.80 g·mol−1
Appearance Grayish-blackish crystal
Odor Odorless
Density 7.234 g/cm3 (25 °C)[1][2]
7.12 g/cm3 (117 °C)[3]
Melting point 836 °C (1,537 °F; 1,109 K)[1]
6.21·10−15 g/L (25 °C)
6.31·10−50
Solubility Soluble in aq. HCN, aq. citric acid with KNO3
Insoluble in acids, alkalies, aqueous ammoniums[4]
Structure
Cubic, cI8 (α-form)
Monoclinic, mP12 (β-form)
Cubic, cF12 (γ-form)[3][5]
Im3m, No. 229 (α-form)[5]
P21/n, No. 14 (β-form)
Fm3m, No. 225 (γ-form)[3]
2/m (α-form)[5]
4/m 3 2/m (β-form, γ-form)[3]
a = 4.23 Å, b = 6.91 Å, c = 7.87 Å (α-form)[5]
α = 90°, β = 99.583°, γ = 90°
Thermochemistry
76.57 J/mol·K[6]
143.93 J/mol·K[6]
−32.59 kJ/mol[6]
−40.71 kJ/mol[6]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 May cause irritation
GHS labelling:
GHS07: Exclamation mark[2]
Warning
H315, H319, H335[2]
P261, P305+P351+P338[2]
NFPA 704 (fire diamond)
[7]
NFPA 704 four-colored diamondHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
0
0
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Silver sulfide is an inorganic compound with the formula Ag
2S. A dense black solid, it is the only sulfide of silver. It is useful as a photosensitizer in photography. It constitutes the tarnish that forms over time on silverware and other silver objects. Silver sulfide is insoluble in most solvents, but is degraded by strong acids. Silver sulfide is a network solid made up of silver (electronegativity of 1.98) and sulfur (electronegativity of 2.58) where the bonds have low ionic character (approximately 10%).

  1. ^ a b Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0.
  2. ^ a b c d Sigma-Aldrich Co., Silver sulfide. Retrieved on 2014-07-13.
  3. ^ a b c d Tonkov, E. Yu (1992). High Pressure Phase Transformations: A Handbook. Vol. 1. Gordon and Breach Science Publishers. p. 13. ISBN 978-2-88124-761-3.
  4. ^ Comey, Arthur Messinger; Hahn, Dorothy A. (February 1921). A Dictionary of Chemical Solubilities: Inorganic (2nd ed.). New York: The MacMillan Company. p. 835.
  5. ^ a b c d Cite error: The named reference spring was invoked but never defined (see the help page).
  6. ^ a b c d Pradyot, Patnaik (2003). Handbook of Inorganic Chemicals. The McGraw-Hill Companies, Inc. p. 845. ISBN 978-0-07-049439-8.
  7. ^ "MSDS of Silver Sulfide". saltlakemetals.com. Utah, USA: Salt Lake Metals. Archived from the original on 2014-08-10. Retrieved 2014-07-13.