Silver acetylide
Names | |
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Preferred IUPAC name
Silver acetylide | |
Systematic IUPAC name
Silver(I) ethynediide | |
Other names
Silver percarbide
Silver carbide Silver dicarbide Argentous acetylide Argentous ethynediide Argentous percarbide Argentous carbide Argentous dicarbide | |
Identifiers | |
3D model (
JSmol ) |
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CompTox Dashboard (EPA)
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Properties | |
C2Ag2 | |
Molar mass | 239.758 g·mol−1 |
Appearance | gray or white solid |
Density | 4.47 g/cm3[1] |
Melting point | 120 °C (248 °F; 393 K) |
Boiling point | decomposes |
insoluble | |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards
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highly sensitive primary explosive |
NFPA 704 (fire diamond) | |
Flash point | 77 °C (171 °F; 350 K) |
Thermochemistry | |
Std enthalpy of (ΔfH⦵298)formation |
357.6±5.0 kJ/mol[2] |
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 acetylide is an inorganic
Synthesis
Silver acetylide can be produced by passing acetylene gas through a solution of silver nitrate:[3]
- 2 AgNO
3 (aq) + C
2H
2 (g) → Ag
2C
2 (s) + 2 HNO
3 (aq)
The reaction product is a greyish to white precipitate. This is the same synthesis from Berthelot in which he first found silver acetylide in 1866.[4]
The double salt is formed in acidic or neutral silver nitrate solutions. Performing the synthesis in basic ammonia solution does not allow the double salt to form, producing pure silver acetylide. To properly form the double salt, acetylene gas is passed through dilute silver nitrate and nitric acid solution. Instead of the conventional synthesis of passing acetylene gas through silver nitrate solution, a purer and whiter precipitate can be formed by passing acetylene gas through acetone and adding the acetylene solution drop-wise to a dilute silver nitrate and nitric acid solution. The reaction was performed at ambient room temperature.
Silver acetylide can be formed on the surface of silver or high-silver alloys, e.g. in pipes used for transport of acetylene, if silver brazing was used in their joints.
Explosive character
Pure silver acetylide is a heat- and shock-sensitive primary explosive. Silver acetylide decomposes through the reaction:
- Ag
2C
2 (s) → 2 Ag (s) + 2 C (s)
The
Solubility
Silver acetylide is not soluble in water and is not appreciably soluble in any other solvent.
References
- .
- .
- doi:10.1039/a708439k.
- .
- S2CID 199492549.