Sodium sulfide

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Sodium sulfide
Names
IUPAC name
Sodium sulfide
Other names
Disodium sulfide
Disodium monosulfide
Properties
Na2S
Molar mass 78.0452 g/mol (anhydrous)
240.18 g/mol (nonahydrate)
Appearance Colorless hygroscopic solid
Odor Rotten eggs
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)
Boiling point Decomposes
12.4 g/100 ml (0 °C)
18.6 g/100 ml (20 °C)
39 g/100 ml (50 °C)
Hydrolysis
Solubility Slightly soluble in alcohol
Insoluble in diethyl ether
Hazards
Safety data sheet Sigma-Aldrich
Sigma-Aldrich (nonahydrate)
Related compounds
Related compounds
Hydrogen sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium sulfide is the chemical compound with the chemical formula Na2S, or more commonly its nonahydrate form Na2S·9H2O.

Properties

Chemical

Sodium sulfide reacts with acids to release hydrogen sulfide.

Physical

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.

Availability

Sodium sulfide is sold by chemical suppliers, though it's not easy get hold of in most places.

Preparation

Industrially Na2S is produced by carbothermic reduction of sodium sulfate often using coal:

Na2SO4 + 2 C → Na2S + 2 CO2

In the laboratory, this compound salt can be prepared by reacting elemental sulfur with sodium in anhydrous ammonia, in dry THF with a catalytic amount of naphthalene (forming sodium naphthalenide):

2 Na + S → Na2S

Projects

  • Make hydrogen sulfide (DANGEROUS)
  • Make thioethers

Handling

Safety

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.

Storage

In closed and air-tight bottles, away from moisture and acids.

Disposal

Sodium sulfide can be neutralized with bleach or hydrogen peroxide.

References

Relevant Sciencemadness threads