1313-84-4

Preparation

Sodium sulfide is prepared by heating sodium bisulfate with sodium chloride and coal above 950°C. The product mixture is extracted with water and the hydrated sulfide is obtained from the solution by crystallization: NaHSO4 + NaCl + 2C → Na2S + 2CO2↑ + HCl↑ Sodium sulfide also is produced from its elements in liquid ammonia: Na + 2S → Na2S

Reactions

Sodium sulfide in solid form reacts with carbon dioxide in the presence of moisture to form hydrogen sulfide and sodium carbonate. Thus, the H2S odor of sodium sulfide crystals is attributed to its exposure to moist air: Na2S + H2O + CO2 → Na2CO3 + H2S In aqueous solution, sodium sulfide reacts with a number of metal salts forming insoluble sulfides. When added to dilute mineral acids, hydrogen sulfide is generated.

Physical Properties

The nonahydrate is a yellowish-white crystalline solid; tetragonal crystals; odor of hydrogen sulfide; the color changes on exposure to light and air, first turning to yellow and then becoming brownish-black, deliquescent; density 1.43 g/cm3; decomposes at about 50°C; very soluble in water; aqueous solution strongly alkaline; slightly soluble in alcohol; insoluble in ether.

General Description

Sodium sulfide nonahydrate participates in the conversion of nitroxides to amines, via reduction.