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 | |
| Std molar
entropy (S |
51.3 J·mol−1·K−1 |
| Std enthalpy of
formation (ΔfH |
-573.6 kJ/mol |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
| LD50 (Median dose)
|
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.
Contents
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, depending on the seller.
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
Sodium fluoride is poisonous, and it's toxic if ingested, inhaled or injected.
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.
