Calcium fluoride
| Names | |
|---|---|
| IUPAC name
Calcium fluoride
| |
| Other names
Calcium difluoride
Fluorite Fluorspar | |
| Properties | |
| CaF2 | |
| Molar mass | 78.07 g/mol |
| Appearance | White crystalline solid (single crystals are transparent, natural crystals tend to be colored due to impurities) |
| Odor | Odorless |
| Density | 3.18 g/cm3 |
| Melting point | 1,418 °C (2,584 °F; 1,691 K) |
| Boiling point | 2,533 °C (4,591 °F; 2,806 K) |
| 0.0015 g/100 ml (18 °C) 0.0016 g/100 ml (20 °C) | |
| Solubility | Reacts with sulfuric acid Insoluble in organic solvents |
| Vapor pressure | ~ 0 mmHg |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | Non-flammable |
| Related compounds | |
| Related compounds
|
Sodium fluoride |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Calcium fluoride is an inorganic salt of calcium, with the chemical formula CaF2. It occurs in nature as the mineral known as fluorite or fluorspar. It is a relative inert and insoluble compound.
Contents
Properties
Chemical
Calcium fluoride will react with a strong acid, such sulfuric acid to yield calcium sulfate and hydrogen fluoride.
- CaF2 + H2SO4 → 2 HF + CaSO4
Physical
Calcium fluoride is a white solid compound. Single crystals are transparent. It is extremely poorly soluble in water (0.0016 g/100 mL at 20 °C) and insoluble in organic solvents. It has a melting point of 1,418 °C and boils at 2,533 °C.
Availability
Calcium fluoride occurs naturally as the mineral fluorite, that can be purchased from mineral sellers. Certain homeopathy tablets also contain calcium fluoride. Purer calcium fluoride is available from chemical suppliers.
Calcium fluoride optic objects, such as lens, windows, filters, prisms are an interesting application of the substance. At least one website offers many such items.
Preparation
Calcium fluoride can be prepared by reacting a fluoride, such as sodium fluoride with a soluble calcium salt, such as calcium chloride.
- 2 NaF + CaCl2 → CaF2 + 2 NaCl
Calcium fluoride precipitates out of the solution, which is filtered and dried.
Projects
- Make hydrofluoric acid
- Store elemental fluorine
- Thermite fluxing agent
- Grow crystals
Handling
Safety
Calcium fluoride has poor solubility in water. Contact with strong acids, such as sulfuric acid should be avoided, as it will generate toxic hydrofluoric acid. This includes gastric (hydrochloric) acid: do NOT swallow calcium fluoride!
Storage
Calcium fluoride should be stored away from strong acids.
Disposal
Calcium fluoride does not require any special disposal and can be dumped in the trash.
