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.
Storage
2-8°C
Assay
0.9999
Packaging
1 kg
Stability
Stable. Hygroscopic. Light-sensitive. Flammable. Avoid exposure to air, acids, oxidizers, strong bases, strong reducing agents, most common metals.