Silver(I) fluoride

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Silver(I) fluoride
Names
IUPAC name
Silver(I) fluoride
Properties
AgF
Molar mass 126.8666 g/mol
Appearance Yellow-brown solid (anhydrous)
Colorless solid (hydrated)
Odor Odorless
Density 5.852 g/cm3 (15 °C)
Melting point 435 °C (815 °F; 708 K)
Boiling point 1,159 °C (2,118 °F; 1,432 K)
85.78 g/100 ml (0 °C)
119.8 g/100 ml (10 °C)
179.1 g/100 ml (25 °C)
213.4 g/100 ml (50 °C)
Solubility Soluble in acetonitrile
Poorly soluble in ethanol, methanol
Insoluble in hydrocarbons
Solubility in bromine fluoride 3.33 g/100 g (25 °C)
4.25 g/100 g (70 °C)
Solubility in hydrogen fluoride 83 g/100 g (12 °C)
Solubility in methanol 1.5 g/100 ml (25 °C)
Vapor pressure ~0 mmHg
Thermochemistry
83.7 J·K-1·mol-1
-206 kJ/mol
Hazards
Safety data sheet Sigma-Aldrich
Flash point Non-flammable
Related compounds
Related compounds
Silver chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Silver(I) fluoride (or just silver fluoride) is the inorganic compound with the formula AgF.

It is one of the three main fluorides of silver, the others being silver subfluoride and silver(II) fluoride. However, since silver(I) fluoride is more commonly encountered as it's easier to synthesize, the term "silver fluoride" most often refers to the Ag(I) compound.

Properties

Chemical

In contrast with the other silver halides, anhydrous silver(I) fluoride is not appreciably photosensitive, although the dihydrate is.

Physical

Silver(I) oxide is a chemical compound, which can be colorless (hydrated) or yellow (anhydrous). Unlike the other silver halides, it is very soluble in water. It is also soluble in many other solvents, like acetonitrile.

It is also unique among silver(I) compounds and the silver halides in that it forms the hydrates AgF.(H2O)2 and AgF.(H2O)4 on precipitation from aqueous solution.

Availability

Silver(I) fluoride is sold by lab suppliers, though it's not cheap.

Preparation

Silver(I) fluoride can be produced by adding hydrofluoric acid to silver carbonate or silver(I) oxide, in a PE or PTFE beaker or flask.

Ag2CO3 + 2 HF → 2 AgF + H2O + CO2
Ag2O + 2 HF → 2 AgF + H2O

The silver fluoride is precipitated out of the resulting solution by adding acetone.

High-purity silver(I) fluoride can be produced by the heating of silver carbonate to 310 °C under a hydrogen fluoride environment, in a platinum tube.

Laboratory routes to the compound typically avoid the use of hydrogen fluoride/hydrofluoric acid, due to its hazards. One method is the thermal decomposition of silver tetrafluoroborate:

AgBF4 → AgF + BF3

Projects

  • Fluorinating agent
  • Make fluorocarbons
  • Synthesis of silver diamine fluoride

Handling

Safety

Silver fluoride will release HF in contact with a strong acid, which is hazardous.

Storage

In closed plastic or amber glass.

Disposal

Since silver is expensive, it's best to recycle it.

References

Relevant Sciencemadness threads