| IUPAC name
| Other names
|Molar mass|| 78.0452 g/mol (anhydrous)|
240.18 g/mol (nonahydrate)
|Appearance||Colorless hygroscopic solid|
|Density|| 1.856 g/cm3 (anhydrous)|
1.58 g/cm3 (pentahydrate)
1.43 g/cm3 (nonohydrate)
|Melting point|| 1,176 °C (2,149 °F; 1,449 K) (anhydrous)|
100 °C (212 °F; 373 K) (pentahydrate)
50 °C (122 °F; 323 K) (nonahydrate)
| 12.4 g/100 ml (0 °C)|
18.6 g/100 ml (20 °C)
39 g/100 ml (50 °C)
|Solubility|| Slightly soluble in alcohol|
Insoluble in diethyl ether
|Safety data sheet|| Sigma-Aldrich|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Sodium sulfide is the chemical compound with the chemical formula Na2S, or more commonly its nonahydrate form Na2S·9H2O.
Sodium sulfide reacts with acids to release hydrogen sulfide.
Sodium sulfide is a white solid, though impure samples can be yellow or reddish. It has an unpleasant odor of rotten eggs, from the hydrogen sulfide released by the hydrolysis in moist air.
Sodium sulfide is sold by chemical suppliers, though it's not easy get hold of in most places.
Industrially Na2S is produced by carbothermic reduction of sodium sulfate often using coal:
- Na2SO4 + 2 C → Na2S + 2 CO2
- 2 Na + S → Na2S
- Make hydrogen sulfide (DANGEROUS)
- Make thioethers
Like sodium hydroxide, sodium sulfide is strongly alkaline and can cause skin burns. Acids react with it to rapidly produce hydrogen sulfide, which is highly toxic.
In closed and air-tight bottles, away from moisture and acids.
Sodium sulfide can be neutralized with bleach or hydrogen peroxide.