sodium thiosulfatesodium thiosulfate
a white, crystalline salt, NaSO, used as an antichlor, as a fixing agent in photography, etc.: popularly called sodium hyposulfite or hypo
A white crystalline compound, Na2S2O3, often prepared as a white translucent crystalline pentahydrate, used as a photographic fixing agent, as a bleach and antichlor, and as an antidote for cyanide poisoning. Also called hypo1, hyposulfite, sodium hyposulfite.