Sodium sulfide

Jump to navigation Jump to search


Yellow, hygroscopic lumps. Sodium sulfide is used as a depilatory in dehairing hides and pulling wool. It is also used in the manufacture of rubber, dyes, and paper pulp. Sodium sulfide is used to blacken metals and as a toner for black and white photographs. It is also used in engraving and lithographic printing.

Synonyms and Related Terms

sodium monosulfide; sodium sulfuret


  • Flammable. Fire and explosion risk with percussion or heat.
  • Toxic by ingestion.
  • Corrosive. S
  • Skin contact causes irritation and burns.
  • Reacts with acids to evolve toxic hydrogen sulfide fumes.
  • ThermoFisher: SDS

Physical and Chemical Properties

Soluble in water slowly forming sodium thiosulfate and sodium hydroxide. Slightly soluble in ethanol. Insoluble in ether.

Composition Na2S
CAS 16721-80-5
Melting Point 1180 C
Density 1.856 g/ml
Molecular Weight mol. wt. = 240.18

Resources and Citations

  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 786
  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • Michael McCann, Artist Beware, Watson-Guptill Publications, New York City, 1979
  • Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
  • E.J.LaBarre, Dictionary and Encyclopedia of Paper and Paper-making, Swets & Zeitlinger, Amsterdam, 1969
  • Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
  • Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
  • The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 8830
  • The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
  • Website address 1 Comment: photographic chemicals at