Sodium fluoride

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Sodium fluoride
Names
IUPAC name
Sodium fluoride
Other names
Florocid
Properties
NaF
Molar mass 41.988173 g/mol
Appearance White solid
Odor Odorless
Density 2.558 g/cm3
Melting point 993 °C (1,819 °F; 1,266 K)
Boiling point 1,704 °C (3,099 °F; 1,977 K)
3.64 g/100 ml (0 °C)
4.04 g/100 ml (20 °C)
5.05 g/100 ml (100 °C)
Solubility Reacts with sulfuric acid
Slightly soluble in ammonia, hydrofluoric acid
Negligible in acetone, dimethylformamide, ethanol, methanol, liq. SO2
Insoluble in halocarbons, hydrocarbons
Vapor pressure ~0 mmHg
Acidity (pKa) 7.4
Thermochemistry
51.3 J·mol−1·K−1
-573.6 kJ/mol
Hazards
Safety data sheet Sigma-Aldrich
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
52–200 mg/kg (oral in rats, mice, rabbits)
Related compounds
Related compounds
Sodium chloride
Sodium bromide
Sodium iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium fluoride is an inorganic compound with the formula NaF, a salt of hydrofluoric acid.

Properties

Chemical

Addition of a strong acid, like sulfuric acid will release hydrofluoric acid.

2 NaF + H2SO4 → 2 HF + Na2SO4

Physical

Sodium fluoride is a white solid, poorly soluble in water and most solvents.

Availability

Sodium fluoride is sold by chemical suppliers, though it's sometimes pricey.

It occurs in nature as the rare mineral villiaumite.

Preparation

Can be prepared by neutralizing hydrofluoric acid with a base, like sodium hydroxide, sodium carbonate or sodium bicarbonate.

HF + NaOH → NaF + H2O
2 HF + Na2CO3 → 2 NaF + H2O + CO2
HF + NaHCO3 → NaF + H2O + CO2

Due to its poor solubility, sodium fluoride will precipitate out of the solution.

Projects

  • Make hydrofluoric acid
  • Make fluorocarbons
  • Mineral collecting (villiaumite)

Handling

Safety

Avoid contact with strong acids, as it will release hydrofluoric acid.

Storage

Sodium fluoride is best kept in closed plastic (PE or PP) bottles. Avoid storing it in glass containers. Keep the bottle in a dry place.

Disposal

Should be converted to the less soluble calcium fluoride and dumped in trash. Recycling is also an option.

References

Relevant Sciencemadness threads