Sodium sulfide is an inorganic chemical compound with the formula Na2S that has attained an important position in the organic chemical industry. It is a strong alkaline solution when exposed to moist air it smells like rotten eggs. Although the solid state is yellow in colour in solution it is colourless. Usually, it comes in the grades as “sodium sulfide flakes”.

Properties of Sodium sulfide

Chemical Formula : Na₂S

Density : 1.86 g/cm³

Molecular Weight/ Molar Mass : 78.0452 g/mol

Autoignition temperature : > 480 °C (896 °F; 753 K)

Melting Point : 1176° C (2149° F)

Odour : Odour of rotten eggs

Appearance : Anhydrous yellow crystalline solids

Storage temperature‎ : 2-8°C

pH : 10.4

Solubility : Insoluble in ether; slightly soluble in alcohol

Uses of Sodium sulfide

Used in water treatment as an oxygen scavenger agent and also used as a metal precipitant.

Used in the photographic industry to protect developer solutions from oxidation in textile industry as a bleaching agent.

Utilized in the production of elastic synthetic materials, sulfur colours and other substances.

Used primarily in pulp and paper industry in the craft process. It increases the selectivity of the sulfate cooking process and increase the rate of delignification.