Sodium hydrosulfide is the
chemical compound with the formula NaHS. This compound is the product of the half neutralization of
hydrogen sulfide with
sodium hydroxide. NaHS is a useful reagent for the synthesis of organic and inorganic sulfur compounds, sometimes as a solid reagent, and more often as an aqueous solution. Solid NaHS is colorless and typically smells like H
2S due to hydrolysis by atmospheric moisture. In contrast with
sodium sulfide, Na
2S, which is insoluble in organic solvents, NaHS, being a 1:1 electrolyte, is more soluble. Alternatively, in place of NaHS, H
2S can be treated with an organic amine to generate an
ammonium salt. Solutions of HS
- are sensitive to
oxygen, converting mainly to
polysulfides, indicated by the appearance of yellow.