Sodium sulfide

Sodium sulfide
Names
Other names
Disodium sulfide
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.013.829 Edit this at Wikidata
EC Number
  • 215-211-5
RTECS number
  • WE1905000
UNII
UN number 1385 (anhydrous)
1849 (hydrate)
  • InChI=1S/2Na.S/q2*+1;-2 ☒N
    Key: GRVFOGOEDUUMBP-UHFFFAOYSA-N ☒N
  • InChI=1/2Na.S/q2*+1;-2
    Key: GRVFOGOEDUUMBP-UHFFFAOYAP
  • [Na+].[Na+].[S-2]
Properties
Na2S
Molar mass 78.0452 g/mol (anhydrous)
240.18 g/mol (nonahydrate)
Appearance colorless, hygroscopic solid
Odor none
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 (pentahydrate)
50 °C (nonahydrate)
12.4 g/100 mL (0 °C)
18.6 g/100 mL (20 °C)
39 g/100 mL (50 °C)
(hydrolyses)
Solubility insoluble in ether
slightly soluble in alcohol[1]
−39.0·10−6 cm3/mol
Structure
Antifluorite (cubic), cF12
Fm3m, No. 225
Tetrahedral (Na+); cubic (S2−)
Hazards
GHS labelling:
GHS05: Corrosive GHS06: Toxic GHS07: Exclamation mark GHS09: Environmental hazard
Danger
H302, H311, H314, H400
P260, P264, P270, P273, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P322, P330, P361, P363, P391, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
3
1
1
> 480 °C (896 °F; 753 K)
Safety data sheet (SDS) ICSC 1047
Related compounds
Other anions
 Sodium oxide
Sodium selenide
Sodium telluride
Sodium polonide
Other cations
 Lithium sulfide
Potassium sulfide
Rubidium sulfide
Caesium sulfide
Related compounds
 Sodium hydrosulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium sulfide is a chemical compound with the formula Na2S, or more commonly its hydrate Na2S·9H2O. Both the anhydrous and the hydrated salts in pure crystalline form are colorless solids, although technical grades of sodium sulfide are generally yellow to brick red owing to the presence of polysulfides and commonly supplied as a crystalline mass, in flake form, or as a fused solid. They are water-soluble, giving strongly alkaline solutions. When exposed to moisture, Na2S immediately hydrates to give sodium hydrosulfide.

Some commercial samples are specified as Na2S·xH2O, where a weight percentage of Na2S is specified. Commonly available grades have around 60% Na2S by weight, which means that x is around 3. These grades of sodium sulfide are often marketed as 'sodium sulfide flakes'. These samples consist of NaSH, NaOH, and water.

  1. ^ Kurzin, Alexander V.; Evdokimov, Andrey N.; Golikova, Valerija S.; Pavlova, Olesja S. (June 9, 2010). "Solubility of Sodium Sulfide in Alcohols". J. Chem. Eng. Data. 55 (9): 4080–4081. doi:10.1021/je100276c.