Sodium Hydroxide, flake 98%
Sodium hydroxide, also known as lye and caustic soda,[1][2] is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+and hydroxide anions OH−. Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns. It is highly soluble in water and readily absorbs moisture and carbon dioxide from the air. It forms a series of hydrates NaOH·nH2O.[10]The monohydrate NaOH·H2O crystallizes from water solutions between 12.3 and 61.8 °C.
| NaOH | |
| Molar mass | 39.9971 g mol−1 |
| Appearance | White, waxy, opaque crystals |
| Odor | odorless |
| Density | 2.13 g/cm3 |
| Melting point | 318 °C (604 °F; 591 K) |
| Boiling point | 1,388 °C (2,530 °F; 1,661 K) |
| 418 g/L (0 °C) 1110 g/L (20 °C) 3370 g/L (100 °C) |
|
| Solubility | soluble in glycerol negligible in ammonia insoluble in ether slowly soluble in propylene glycol |
| Solubility in methanol | 238 g/L |
| Solubility in ethanol | <<139 g/L |
| Vapor pressure | <2.4 kPa (at 20 °C) |
| Basicity (pKb) | -0.56 (NaOH(aq) = Na+ + OH–) [5] |
| −16.0·10−6 cm3/mol | |
|
Refractive index(nD)
|
1.3576 |